Release v1.0.2

Signed-off-by: José Valim <jose.valim@plataformatec.com.br>

Conflicts:
	Makefile

.appveyor.yml

@@ -1,9 +0,0 @@
-version: 1-{branch}+{build}
-
-build_script:
-  - cmd: C:\MinGW\msys\1.0\bin\make
-  - cmd: rmdir /s /q .git
-before_test:
-  - cmd: set PATH=%PATH%;C:\Program Files\erl8.3\erts-8.3\bin
-test_script:
-  - cmd: C:\MinGW\msys\1.0\bin\make --keep-going test_windows

.gitignore

@@ -1,14 +1,13 @@
-/doc/
-/lib/*/ebin/
-/lib/*/_build/
-/lib/*/tmp/
-/lib/elixir/src/*_parser.erl
-/lib/elixir/src/elixir.app.src
-/lib/elixir/test/ebin/
-/man/elixir.1
-/man/iex.1
-/Docs-v*.zip
-/Precompiled-v*.zip
 /.eunit
-.elixir.plt
+/.release
+/docs
+/ebin
+/lib/*/ebin/*
+/lib/*/tmp
+/lib/elixir/src/elixir.app.src
+/lib/elixir/src/*_lexer.erl
+/lib/elixir/src/*_parser.erl
+/lib/elixir/test/ebin
+/rel/elixir
 erl_crash.dump
+.elixir.plt

.travis.yml

@@ -1,32 +1,11 @@
 language: erlang
-sudo: false
-
-os: linux
-otp_release: 18.0
-
-matrix:
-  include:
-    - os: linux
-      otp_release: 18.1
-    - os: linux
-      otp_release: 18.2
-    - os: linux
-      otp_release: 18.3
-    - os: linux
-      otp_release: 19.0
-    - os: linux
-      otp_release: 19.1
-    - os: linux
-      otp_release: 19.2
-    - os: linux
-      otp_release: 19.3
-    - os: linux
-      otp_release: 20.0
-
 script: "make compile && rm -rf .git && make test"
-
 notifications:
+  irc: "irc.freenode.org#elixir-lang"
   recipients:
     - jose.valim@plataformatec.com.br
     - eric.meadows.jonsson@gmail.com
-
+otp_release:
+  - 17.0
+  - 17.1
+  - 17.3

CODE_OF_CONDUCT.md

@@ -1,56 +0,0 @@
-# Code of Conduct
-
-Contact: elixir-lang-conduct@googlegroups.com
-
-## Why have a Code of Conduct?
-
-As contributors and maintainers of this project, we are committed to providing a friendly, safe and welcoming environment for all, regardless of age, disability, gender, nationality, race, religion, sexuality, or similar personal characteristic.
-
-The goal of the Code of Conduct is to specify a baseline standard of behavior so that people with different social values and communication styles can talk about Elixir effectively, productively, and respectfully, even in face of disagreements. The Code of Conduct also provides a mechanism for resolving conflicts in the community when they arise.
-
-## Our Values
-
-These are the values Elixir developers should aspire to:
-
-  * Be friendly and welcoming
-  * Be patient
-    * Remember that people have varying communication styles and that not everyone is using their native language. (Meaning and tone can be lost in translation.)
-  * Be thoughtful
-    * Productive communication requires effort. Think about how your words will be interpreted.
-    * Remember that sometimes it is best to refrain entirely from commenting.
-  * Be respectful
-    * In particular, respect differences of opinion. It is important that we resolve disagreements and differing views constructively.
-  * Avoid destructive behavior
-    * Derailing: stay on topic; if you want to talk about something else, start a new conversation.
-    * Unconstructive criticism: don't merely decry the current state of affairs; offer (or at least solicit) suggestions as to how things may be improved.
-    * Snarking (pithy, unproductive, sniping comments).
-
-The following actions are explicitly forbidden:
-
-  * Insulting, demeaning, hateful, or threatening remarks.
-  * Discrimination based on age, disability, gender, nationality, race, religion, sexuality, or similar personal characteristic.
-  * Bullying or systematic harassment.
-  * Unwelcome sexual advances.
-  * Incitement to any of these.
-
-## Where does the Code of Conduct apply?
-
-If you participate in or contribute to the Elixir ecosystem in any way, you are encouraged to follow the Code of Conduct while doing so.
-
-Explicit enforcement of the Code of Conduct applies to the official mediums operated by the Elixir project:
-
-* The official GitHub projects and code reviews.
-* The official elixir-lang mailing lists.
-* The #elixir-lang IRC channel on Freenode.
-
-Other Elixir activities (such as conferences, meetups, and other unofficial forums) are encouraged to adopt this Code of Conduct. Such groups must provide their own contact information.
-
-Project maintainers may remove, edit, or reject comments, commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of Conduct.
-
-Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by emailing: elixir-lang-conduct@googlegroups.com. All complaints will be reviewed and investigated and will result in a response that is deemed necessary and appropriate to the circumstances. **All reports will be kept confidential**.
-
-**The goal of the Code of Conduct is to resolve conflicts in the most harmonious way possible**. We hope that in most cases issues may be resolved through polite discussion and mutual agreement. Bannings and other forceful measures are to be employed only as a last resort. **Do not** post about the issue publicly or try to rally sentiment against a particular individual or group.
-
-## Acknowledgements
-
-This document was based on the Code of Conduct from the Go project with parts derived from Django's Code of Conduct, Rust's Code of Conduct and the Contributor Covenant.

CONTRIBUTING.md

@@ -0,0 +1,265 @@
+# Contributing to Elixir
+
+Please take a moment to review this document in order to make the contribution
+process easy and effective for everyone involved!
+
+## Using the issue tracker
+
+Use the issues tracker for:
+
+* [bug reports](#bugs-reports)
+* [submitting pull requests](#pull-requests)
+
+Please **do not** use the issue tracker for personal support requests nor feature requests. Support requests should be sent to:
+
+* [the elixir-talk mailing list](http://groups.google.com/group/elixir-lang-talk)
+* [Stack Overflow](http://stackoverflow.com/questions/ask?tags=elixir)
+* [#elixir-lang](irc://chat.freenode.net/elixir-lang)
+
+Feature requests can be discussed on [the elixir-core mailing list](http://groups.google.com/group/elixir-lang-core).
+
+We do our best to keep the issue tracker tidy and organized, making it useful
+for everyone. For example, we classify open issues per application and perceived
+difficulty of the issue, making it easier for developers to
+[contribute to Elixir](#contributing).
+
+## Bug reports
+
+A bug is a _demonstrable problem_ that is caused by the code in the repository.
+Good bug reports are extremely helpful - thank you!
+
+Guidelines for bug reports:
+
+1. **Use the GitHub issue search** — check if the issue has already been
+   reported.
+
+2. **Check if the issue has been fixed** — try to reproduce it using the
+   `master` branch in the repository.
+
+3. **Isolate and report the problem** — ideally create a reduced test
+   case.
+
+Please try to be as detailed as possible in your report. Include information about
+your Operating System, your Erlang and Elixir versions. Please provide steps to
+reproduce the issue as well as the outcome you were expecting! All these details
+will help developers to fix any potential bugs.
+
+Example:
+
+> Short and descriptive example bug report title
+>
+> A summary of the issue and the environment in which it occurs. If suitable,
+> include the steps required to reproduce the bug.
+>
+> 1. This is the first step
+> 2. This is the second step
+> 3. Further steps, etc.
+>
+> `<url>` - a link to the reduced test case (e.g. a GitHub Gist)
+>
+> Any other information you want to share that is relevant to the issue being
+> reported. This might include the lines of code that you have identified as
+> causing the bug, and potential solutions (and your opinions on their
+> merits).
+
+## Feature requests
+
+Feature requests are welcome and should be discussed on [the elixir-core mailing list](http://groups.google.com/group/elixir-lang-core). But take a moment to find
+out whether your idea fits with the scope and aims of the project. It's up to *you*
+to make a strong case to convince the community of the merits of this feature.
+Please provide as much detail and context as possible.
+
+## Contributing
+
+We incentivize everyone to contribute to Elixir and help us tackle
+existing issues! To do so, there are a few things you need to know
+about the code. First, Elixir code is divided in applications inside
+the `lib` folder:
+
+* `elixir` - Contains Elixir's kernel and stdlib
+
+* `eex` - Template engine that allows you to embed Elixir
+
+* `ex_unit` - Simple test framework that ships with Elixir
+
+* `iex` — IEx, Elixir's interactive shell
+
+* `mix` — Elixir's build tool
+
+You can run all tests in the root directory with `make test` and you can
+also run tests for a specific framework `make test_#{NAME}`, for example,
+`make test_ex_unit`.
+
+In case you are changing a single file, you can compile and run tests only
+for that particular file for fast development cycles. For example, if you
+are changing the String module, you can compile it and run its tests as:
+
+    $ bin/elixirc lib/elixir/lib/string.ex -o lib/elixir/ebin
+    $ bin/elixir lib/elixir/test/elixir/string_test.exs
+
+After your changes are done, please remember to run the full suite with
+`make test`.
+
+From time to time, your tests may fail in an existing Elixir checkout and
+may require a clean start by running `make clean compile`. You can always
+check [the official build status on Travis-CI](https://travis-ci.org/elixir-lang/elixir).
+
+With tests running and passing, you are ready to contribute to Elixir and
+send your pull requests.
+
+## Contributing Documentation
+
+Code documentation (`@doc`, `@moduledoc`, `@typedoc`) has a special convention:
+the first paragraph is considered to be a short summary.
+
+For functions, macros and callbacks say what it will do. For example write
+something like:
+
+```elixir
+@doc """
+Returns only those elements for which `fun` is true.
+
+...
+"""
+def filter(collection, fun) ...
+```
+
+For modules, protocols and types say what it is. For example write
+something like:
+
+```elixir
+defmodule File.Stat do
+  @moduledoc """
+  Information about a file.
+
+  ...
+  """
+
+  defstruct [...]
+end
+```
+
+Keep in mind that the first paragraph might show up in a summary somewhere, long
+texts in the first paragraph create very ugly summaries. As a rule of thumb
+anything longer than 80 characters is too long.
+
+Try to keep unneccesary details out of the first paragraph, it's only there to
+give a user a quick idea of what the documented "thing" does/is. The rest of the
+documentation string can contain the details, for example when a value and when
+`nil` is returned.
+
+If possible include examples, preferably in a form that works with doctests. For
+example:
+
+```elixir
+@doc """
+Return only those elements for which `fun` is true.
+
+## Examples
+
+    iex> Enum.filter([1, 2, 3], fn(x) -> rem(x, 2) == 0 end)
+    [2]
+
+"""
+def filter(collection, fun) ...
+```
+
+This makes it easy to test the examples so that they don't go stale and examples
+are often a great help in explaining what a function does.
+
+## Pull requests
+
+Good pull requests - patches, improvements, new features - are a fantastic
+help. They should remain focused in scope and avoid containing unrelated
+commits.
+
+**IMPORTANT**: By submitting a patch, you agree that your work will be
+licensed under the license used by the project.
+
+If you have any large pull request in mind (e.g. implementing features,
+refactoring code, etc), **please ask first** otherwise you risk spending
+a lot of time working on something that the project's developers might
+not want to merge into the project.
+
+Please adhere to the coding conventions in the project (indentation,
+accurate comments, etc.) and don't forget to add your own tests and
+documentation. When working with git, we recommend the following process
+in order to craft an excellent pull request:
+
+1. [Fork](http://help.github.com/fork-a-repo/) the project, clone your fork,
+   and configure the remotes:
+
+   ```bash
+   # Clone your fork of the repo into the current directory
+   git clone https://github.com/<your-username>/elixir
+   # Navigate to the newly cloned directory
+   cd elixir
+   # Assign the original repo to a remote called "upstream"
+   git remote add upstream https://github.com/elixir-lang/elixir
+   ```
+
+2. If you cloned a while ago, get the latest changes from upstream:
+
+   ```bash
+   git checkout master
+   git pull upstream master
+   ```
+
+3. Create a new topic branch (off of `master`) to contain your feature, change,
+   or fix.
+
+   **IMPORTANT**: Making changes in `master` is discouraged. You should always
+   keep your local `master` in sync with upstream `master` and make your
+   changes in topic branches.
+
+   ```bash
+   git checkout -b <topic-branch-name>
+   ```
+
+4. Commit your changes in logical chunks. Keep your commit messages organized,
+   with a short description in the first line and more detailed information on
+   the following lines. Feel free to use Git's
+   [interactive rebase](https://help.github.com/articles/interactive-rebase)
+   feature to tidy up your commits before making them public.
+
+5. Make sure all the tests are still passing.
+
+   ```bash
+   make test
+   ```
+
+   This command will compile the code in your branch and use that
+   version of Elixir to run the tests. This is needed to ensure your changes can
+   pass all the tests.
+
+6. Push your topic branch up to your fork:
+
+   ```bash
+   git push origin <topic-branch-name>
+   ```
+
+7. [Open a Pull Request](https://help.github.com/articles/using-pull-requests/)
+    with a clear title and description.
+
+8. If you haven't updated your pull request for a while, you should consider
+   rebasing on master and resolving any conflicts.
+
+   **IMPORTANT**: _Never ever_ merge upstream `master` into your branches. You
+   should always `git rebase` on `master` to bring your changes up to date when
+   necessary.
+
+   ```bash
+   git checkout master
+   git pull upstream master
+   git checkout <your-topic-branch>
+   git rebase master
+   ```
+
+We have saved some excellent pull requests we have received in the past in case
+you are looking for some examples:
+
+* https://github.com/elixir-lang/elixir/pull/992
+* https://github.com/elixir-lang/elixir/pull/1058
+* https://github.com/elixir-lang/elixir/pull/1059
+
+Thank you for your contributions!

ISSUE_TEMPLATE.md

@@ -1,18 +0,0 @@
-### Precheck
-
-* Do not use the issues tracker for help or support (try Elixir Forum, Stack Overflow, IRC, etc.)
-* For proposing a new feature, please start a discussion on the Elixir Core mailing list
-* For bugs, do a quick search and make sure the bug has not yet been reported
-* Finally, be nice and have fun!
-
-### Environment
-
-* Elixir & Erlang versions (elixir --version): 
-* Operating system: 
-
-### Current behavior
-
-Include code samples, errors and stacktraces if appropriate.
-
-### Expected behavior
-

LEGAL

@@ -0,0 +1,8 @@
+LEGAL NOTICE INFORMATION
+------------------------
+
+All the files in this distribution are covered under either Elixir's
+license (see the file LICENSE) except the files mentioned below that
+contains sections that are under Erlang's License (EPL):
+
+lib/elixir/src/elixir_parser.erl (generated by build scripts)

LICENSE

@@ -1,4 +1,4 @@
-Copyright 2012 Plataformatec
+Copyright 2012-2013 Plataformatec.
 
   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.

Makefile

@@ -1,31 +1,29 @@
-REBAR ?= "$(CURDIR)/rebar"
-PREFIX ?= /usr/local
-SHARE_PREFIX ?= $(PREFIX)/share
-CANONICAL := v1.5/
+REBAR := rebar
+DOCS := v1.0
 ELIXIRC := bin/elixirc --verbose --ignore-module-conflict
 ERLC := erlc -I lib/elixir/include
 ERL := erl -I lib/elixir/include -noshell -pa lib/elixir/ebin
 VERSION := $(strip $(shell cat VERSION))
 Q := @
+PREFIX := /usr/local
 LIBDIR := lib
-BINDIR := bin
 INSTALL = install
 INSTALL_DIR = $(INSTALL) -m755 -d
 INSTALL_DATA = $(INSTALL) -m644
 INSTALL_PROGRAM = $(INSTALL) -m755
-GIT_REVISION = $(strip $(shell git rev-parse HEAD 2> /dev/null ))
-GIT_TAG = $(strip $(shell head="$(call GIT_REVISION)"; git tag --points-at $$head 2> /dev/null | tail -1) )
 
-.PHONY: install compile erlang elixir build_plt clean_plt dialyze test clean clean_residual_files install_man clean_man docs Docs.zip Precompiled.zip zips
+.PHONY: install compile erlang elixir build_plt clean_plt dialyze test clean docs release_docs release_zip check_erlang_release
 .NOTPARALLEL: compile
 
 #==> Functions
 
+# This check should work for older versions like R16B
+# as well as new verions like 17.1 and 18
 define CHECK_ERLANG_RELEASE
-	$(Q) erl -noshell -eval '{V,_} = string:to_integer(erlang:system_info(otp_release)), io:fwrite("~s", [is_integer(V) and (V >= 18)])' -s erlang halt | grep -q '^true'; \
-		if [ $$? != 0 ]; then \
-		  echo "At least Erlang 18.0 is required to build Elixir"; \
-		  exit 1; \
+	$(Q) erl -noshell -eval 'io:fwrite("~s", [erlang:system_info(otp_release)])' -s erlang halt | grep -q '^1[789]'; \
+		if [ $$? != 0 ]; then                                                                                        \
+		   echo "At least Erlang 17.0 is required to build Elixir";                                                  \
+		   exit 1;                                                                                                   \
 		fi;
 endef
 
@@ -44,7 +42,7 @@ lib/$(1)/ebin/Elixir.$(2).beam: $(wildcard lib/$(1)/lib/*.ex) $(wildcard lib/$(1
 	@ rm -rf lib/$(1)/ebin
 	$(Q) cd lib/$(1) && ../../$$(ELIXIRC) "lib/**/*.ex" -o ebin
 
-test_$(1): compile $(1)
+test_$(1): $(1)
 	@ echo "==> $(1) (exunit)"
 	$(Q) cd lib/$(1) && ../../bin/elixir -r "test/test_helper.exs" -pr "test/**/*_test.exs";
 endef
@@ -60,38 +58,37 @@ compile: lib/elixir/src/elixir.app.src erlang elixir
 
 lib/elixir/src/elixir.app.src: src/elixir.app.src
 	$(Q) $(call CHECK_ERLANG_RELEASE)
-	$(Q) rm -f lib/elixir/src/elixir.app.src
+	$(Q) rm -rf lib/elixir/src/elixir.app.src
 	$(Q) echo "%% This file is automatically generated from <project_root>/src/elixir.app.src" \
-	          >lib/elixir/src/elixir.app.src
+	                             >lib/elixir/src/elixir.app.src
 	$(Q) cat src/elixir.app.src >>lib/elixir/src/elixir.app.src
 
 erlang:
-	$(Q) cd lib/elixir && $(REBAR) compile
+	$(Q) cd lib/elixir && ../../$(REBAR) compile
 
-# Since Mix depends on EEx and EEx depends on Mix,
-# we first compile EEx without the .app file,
-# then mix and then compile EEx fully
+# Since Mix depends on EEx and EEx depends on
+# Mix, we first compile EEx without the .app
+# file, then mix and then compile EEx fully
 elixir: stdlib lib/eex/ebin/Elixir.EEx.beam mix ex_unit logger eex iex
 
 stdlib: $(KERNEL) VERSION
 $(KERNEL): lib/elixir/lib/*.ex lib/elixir/lib/*/*.ex lib/elixir/lib/*/*/*.ex
-	$(Q) if [ ! -f $(KERNEL) ]; then \
-		echo "==> bootstrap (compile)"; \
-		$(ERL) -s elixir_compiler bootstrap -s erlang halt; \
+	$(Q) if [ ! -f $(KERNEL) ]; then                    \
+		echo "==> bootstrap (compile)";                 \
+		$(ERL) -s elixir_compiler core -s erlang halt;  \
 	fi
 	@ echo "==> elixir (compile)";
 	$(Q) cd lib/elixir && ../../$(ELIXIRC) "lib/kernel.ex" -o ebin;
 	$(Q) cd lib/elixir && ../../$(ELIXIRC) "lib/**/*.ex" -o ebin;
 	$(Q) $(MAKE) unicode
-	$(Q) rm -f lib/elixir/ebin/elixir.app
-	$(Q) cd lib/elixir && $(REBAR) compile
+	$(Q) rm -rf lib/elixir/ebin/elixir.app
+	$(Q) cd lib/elixir && ../../$(REBAR) compile
 
 unicode: $(UNICODE)
 $(UNICODE): lib/elixir/unicode/*
 	@ echo "==> unicode (compile)";
-	$(Q) $(ELIXIRC) lib/elixir/unicode/unicode.ex -o lib/elixir/ebin;
-	$(Q) $(ELIXIRC) lib/elixir/unicode/properties.ex -o lib/elixir/ebin;
-	$(Q) $(ELIXIRC) lib/elixir/unicode/tokenizer.ex -o lib/elixir/ebin;
+	@ echo "Embedding the Unicode database... (this may take a while)"
+	$(Q) cd lib/elixir && ../../$(ELIXIRC) unicode/unicode.ex -o ebin;
 
 $(eval $(call APP_TEMPLATE,ex_unit,ExUnit))
 $(eval $(call APP_TEMPLATE,logger,Logger))
@@ -102,106 +99,71 @@ $(eval $(call APP_TEMPLATE,iex,IEx))
 install: compile
 	@ echo "==> elixir (install)"
 	$(Q) for dir in lib/*; do \
-		rm -rf $(DESTDIR)$(PREFIX)/$(LIBDIR)/elixir/$$dir/ebin; \
 		$(INSTALL_DIR) "$(DESTDIR)$(PREFIX)/$(LIBDIR)/elixir/$$dir/ebin"; \
 		$(INSTALL_DATA) $$dir/ebin/* "$(DESTDIR)$(PREFIX)/$(LIBDIR)/elixir/$$dir/ebin"; \
 	done
 	$(Q) $(INSTALL_DIR) "$(DESTDIR)$(PREFIX)/$(LIBDIR)/elixir/bin"
 	$(Q) $(INSTALL_PROGRAM) $(filter-out %.ps1, $(filter-out %.bat, $(wildcard bin/*))) "$(DESTDIR)$(PREFIX)/$(LIBDIR)/elixir/bin"
-	$(Q) $(INSTALL_DIR) "$(DESTDIR)$(PREFIX)/$(BINDIR)"
-	$(Q) for file in "$(DESTDIR)$(PREFIX)"/$(LIBDIR)/elixir/bin/*; do \
-		ln -sf "../$(LIBDIR)/elixir/bin/$${file##*/}" "$(DESTDIR)$(PREFIX)/$(BINDIR)/"; \
+	$(Q) $(INSTALL_DIR) "$(DESTDIR)$(PREFIX)/bin"
+	$(Q) for file in "$(DESTDIR)$(PREFIX)"/$(LIBDIR)/elixir/bin/* ; do \
+		ln -sf "../$(LIBDIR)/elixir/bin/$${file##*/}" "$(DESTDIR)$(PREFIX)/bin/" ; \
 	done
-	$(MAKE) install_man
 
 clean:
-	cd lib/elixir && $(REBAR) clean
+	cd lib/elixir && ../../$(REBAR) clean
 	rm -rf ebin
 	rm -rf lib/*/ebin
-	rm -f lib/elixir/src/elixir.app.src
-	$(Q) $(MAKE) clean_residual_files
+	rm -rf lib/elixir/test/ebin
+	rm -rf lib/*/tmp
+	rm -rf lib/mix/test/fixtures/git_repo
+	rm -rf lib/mix/test/fixtures/deps_on_git_repo
+	rm -rf lib/mix/test/fixtures/git_rebar
+	rm -rf lib/elixir/src/elixir.app.src
 
-clean_elixir:
+clean_exbeam:
 	$(Q) rm -f lib/*/ebin/Elixir.*.beam
 
-clean_residual_files:
-	rm -rf lib/*/_build/
-	rm -rf lib/*/tmp/
-	rm -rf lib/elixir/test/ebin/
-	rm -rf lib/mix/test/fixtures/deps_on_git_repo/
-	rm -rf lib/mix/test/fixtures/git_rebar/
-	rm -rf lib/mix/test/fixtures/git_repo/
-	rm -rf lib/mix/test/fixtures/git_sparse_repo/
-	rm -f erl_crash.dump
-	$(Q) $(MAKE) clean_man
+#==> Release tasks
 
-#==> Documentation tasks
+SOURCE_REF = $(shell head="$$(git rev-parse HEAD)" tag="$$(git tag --points-at $$head | tail -1)" ; echo "$${tag:-$$head}\c")
+DOCS = bin/elixir ../ex_doc/bin/ex_doc "$(1)" "$(VERSION)" "lib/$(2)/ebin" -m "$(3)" -u "https://github.com/elixir-lang/elixir" --source-ref "$(call SOURCE_REF)" -o docs/$(2) -p http://elixir-lang.org/docs.html
 
-LOGO_PATH = $(shell test -f ../docs/logo.png && echo "--logo ../docs/logo.png")
-SOURCE_REF = $(shell tag="$(call GIT_TAG)" revision="$(call GIT_REVISION)"; echo "$${tag:-$$revision}\c")
-DOCS_FORMAT = html
-COMPILE_DOCS = bin/elixir ../ex_doc/bin/ex_doc "$(1)" "$(VERSION)" "lib/$(2)/ebin" -m "$(3)" -u "https://github.com/elixir-lang/elixir" --source-ref "$(call SOURCE_REF)" $(call LOGO_PATH) -o doc/$(2) -n https://hexdocs.pm/$(2)/$(CANONICAL) -p http://elixir-lang.org/docs.html -f "$(DOCS_FORMAT)" $(4)
-
-docs: compile ../ex_doc/bin/ex_doc docs_elixir docs_eex docs_mix docs_iex docs_ex_unit docs_logger
-
-docs_elixir: compile ../ex_doc/bin/ex_doc
-	@ echo "==> ex_doc (elixir)"
-	$(Q) rm -rf doc/elixir
-	$(call COMPILE_DOCS,Elixir,elixir,Kernel,-e "lib/elixir/pages/Behaviours.md" -e "lib/elixir/pages/Deprecations.md" -e "lib/elixir/pages/Guards.md" -e "lib/elixir/pages/Naming Conventions.md" -e "lib/elixir/pages/Operators.md" -e "lib/elixir/pages/Syntax Reference.md" -e "lib/elixir/pages/Typespecs.md" -e "lib/elixir/pages/Unicode Syntax.md" -e "lib/elixir/pages/Writing Documentation.md")
-
-docs_eex: compile ../ex_doc/bin/ex_doc
-	@ echo "==> ex_doc (eex)"
-	$(Q) rm -rf doc/eex
-	$(call COMPILE_DOCS,EEx,eex,EEx)
-
-docs_mix: compile ../ex_doc/bin/ex_doc
-	@ echo "==> ex_doc (mix)"
-	$(Q) rm -rf doc/mix
-	$(call COMPILE_DOCS,Mix,mix,Mix)
-
-docs_iex: compile ../ex_doc/bin/ex_doc
-	@ echo "==> ex_doc (iex)"
-	$(Q) rm -rf doc/iex
-	$(call COMPILE_DOCS,IEx,iex,IEx)
-
-docs_ex_unit: compile ../ex_doc/bin/ex_doc
-	@ echo "==> ex_doc (ex_unit)"
-	$(Q) rm -rf doc/ex_unit
-	$(call COMPILE_DOCS,ExUnit,ex_unit,ExUnit)
-
-docs_logger: compile ../ex_doc/bin/ex_doc
-	@ echo "==> ex_doc (logger)"
-	$(Q) rm -rf doc/logger
-	$(call COMPILE_DOCS,Logger,logger,Logger)
+docs: compile ../ex_doc/bin/ex_doc
+	$(Q) rm -rf docs
+	$(call DOCS,Elixir,elixir,Kernel)
+	$(call DOCS,EEx,eex,EEx)
+	$(call DOCS,Mix,mix,Mix)
+	$(call DOCS,IEx,iex,IEx)
+	$(call DOCS,ExUnit,ex_unit,ExUnit)
+	$(call DOCS,Logger,logger,Logger)
 
 ../ex_doc/bin/ex_doc:
 	@ echo "ex_doc is not found in ../ex_doc as expected. See README for more information."
 	@ false
 
-#==> Zip tasks
+release_zip: compile
+	rm -rf v$(VERSION).zip
+	zip -9 -r v$(VERSION).zip bin CHANGELOG.md LEGAL lib/*/ebin LICENSE Makefile README.md VERSION
 
-Docs.zip: docs
-	rm -f Docs-v$(VERSION).zip
-	zip -9 -r Docs-v$(VERSION).zip CHANGELOG.md doc NOTICE LICENSE README.md
-	@ echo "Docs file created $(CURDIR)/Docs-v$(VERSION).zip"
+release_docs: docs
+	cd ../docs
+	rm -rf ../docs/$(DOCS)
+	mv docs ../docs/$(DOCS)
 
-Precompiled.zip: build_man compile
-	rm -f Precompiled-v$(VERSION).zip
-	zip -9 -r Precompiled-v$(VERSION).zip bin CHANGELOG.md lib/*/ebin LICENSE man NOTICE README.md VERSION
-	@ echo "Precompiled file created $(CURDIR)/Precompiled-v$(VERSION).zip"
+# This task requires aws-cli to be installed and set up for access to s3.hex.pm
+# See: http://docs.aws.amazon.com/cli/latest/userguide/cli-chap-getting-set-up.html
 
-zips: Precompiled.zip Docs.zip
+publish_mix: compile
+	cd lib/mix && MIX_ENV=prod mix escript.build
+	aws s3 cp lib/mix/mix s3://s3.hex.pm/builds/mix/v$(VERSION)/mix --acl public-read
+	aws s3 cp lib/mix/mix s3://s3.hex.pm/builds/mix/mix --acl public-read
+	rm lib/mix/mix
+	rm -rf lib/mix/_build
 
-#==> Test tasks
+#==> Tests tasks
 
 test: test_erlang test_elixir
 
-test_windows: test test_taskkill
-
-test_taskkill:
-	taskkill //IM erl.exe //F //T //FI "MEMUSAGE gt 0"
-	taskkill //IM epmd.exe //F //T //FI "MEMUSAGE gt 0"
-
 TEST_ERL = lib/elixir/test/erlang
 TEST_EBIN = lib/elixir/test/ebin
 TEST_ERLS = $(addprefix $(TEST_EBIN)/, $(addsuffix .beam, $(basename $(notdir $(wildcard $(TEST_ERL)/*.erl)))))
@@ -215,7 +177,11 @@ $(TEST_EBIN)/%.beam: $(TEST_ERL)/%.erl
 	$(Q) mkdir -p $(TEST_EBIN)
 	$(Q) $(ERLC) -o $(TEST_EBIN) $<
 
-test_elixir: test_stdlib test_ex_unit test_logger test_mix test_eex test_iex
+test_elixir: test_stdlib test_ex_unit test_logger test_doc_test test_mix test_eex test_iex
+
+test_doc_test: compile
+	@ echo "==> doctest (exunit)"
+	$(Q) cd lib/elixir && ../../bin/elixir -r "test/doc_test.exs";
 
 test_stdlib: compile
 	@ echo "==> elixir (exunit)"
@@ -243,33 +209,3 @@ build_plt: clean_plt $(PLT)
 dialyze: compile $(PLT)
 	@ echo "==> Dialyzing Elixir..."
 	$(Q) dialyzer --plt $(PLT) $(DIALYZER_OPTS) lib/*/ebin
-
-#==> Man page tasks
-
-build_man: man/iex.1 man/elixir.1
-
-man/iex.1:
-	$(Q) cp man/iex.1.in man/iex.1
-	$(Q) sed -i.bak "/{COMMON}/r common" man/iex.1
-	$(Q) sed -i.bak "/{COMMON}/d" man/iex.1
-	$(Q) rm -f man/iex.1.bak
-
-man/elixir.1:
-	$(Q) cp man/elixir.1.in man/elixir.1
-	$(Q) sed -i.bak "/{COMMON}/r common" man/elixir.1
-	$(Q) sed -i.bak "/{COMMON}/d" man/elixir.1
-	$(Q) rm -f man/elixir.1.bak
-
-clean_man:
-	rm -f man/elixir.1
-	rm -f man/elixir.1.bak
-	rm -f man/iex.1
-	rm -f man/iex.1.bak
-
-install_man: build_man
-	$(Q) mkdir -p $(DESTDIR)$(SHARE_PREFIX)/man/man1
-	$(Q) $(INSTALL_DATA) man/elixir.1  $(DESTDIR)$(SHARE_PREFIX)/man/man1
-	$(Q) $(INSTALL_DATA) man/elixirc.1 $(DESTDIR)$(SHARE_PREFIX)/man/man1
-	$(Q) $(INSTALL_DATA) man/iex.1     $(DESTDIR)$(SHARE_PREFIX)/man/man1
-	$(Q) $(INSTALL_DATA) man/mix.1     $(DESTDIR)$(SHARE_PREFIX)/man/man1
-	$(MAKE) clean_man

NOTICE

@@ -1,22 +0,0 @@
-LEGAL NOTICE INFORMATION
-------------------------
-
-All the files in this distribution are copyright (c) 2012 Plataformatec
-covered under Elixir's license (see the file LICENSE) except the cases
-below.
-
-== lib/elixir/src/elixir_parser.erl (generated by build scripts)
-
-Copyright Ericsson AB 1996-2015
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.

README.md

@@ -1,183 +1,59 @@
 ![Elixir](https://github.com/elixir-lang/elixir-lang.github.com/raw/master/images/logo/logo.png)
 =========
-[![Travis build](https://secure.travis-ci.org/elixir-lang/elixir.svg?branch=master
-"Build Status")](https://travis-ci.org/elixir-lang/elixir)
-[![Windows build](https://ci.appveyor.com/api/projects/status/macwuxq7aiiv61g1?svg=true)](https://ci.appveyor.com/project/josevalim/elixir)
+[![Build Status](https://secure.travis-ci.org/elixir-lang/elixir.svg?branch=master "Build Status")](http://travis-ci.org/elixir-lang/elixir)
 
+For more about Elixir, installation and documentation, [check Elixir's website](http://elixir-lang.org/).
 
-Elixir is a dynamic, functional language designed for building scalable and maintainable applications.
+## Usage
 
-For more about Elixir, installation and documentation,
-[check Elixir's website](http://elixir-lang.org/).
+If you want to contribute to Elixir or run it from source, clone this repository to your machine, compile and test it:
 
-## Compiling from source
+    $ git clone https://github.com/elixir-lang/elixir.git
+    $ cd elixir
+    $ make clean test
 
-To run Elixir from source, clone this repository to your machine, compile and test it:
+> Note: if you are running on Windows, [this article includes important notes for compiling Elixir from source on Windows](https://github.com/elixir-lang/elixir/wiki/Windows).
 
-```sh
-git clone https://github.com/elixir-lang/elixir.git
-cd elixir
-make clean test
-```
+If Elixir fails to build (specifically when pulling in a new version via git), be sure to remove any previous build artifacts by running `make clean`, then `make test`.
 
-> Note: if you are running on Windows,
-[this article includes important notes for compiling Elixir from source
-on Windows](https://github.com/elixir-lang/elixir/wiki/Windows).
+If tests pass, you are ready to move on to the [Getting Started guide][1] or to try Interactive Elixir by running: `bin/iex` in your terminal.
 
-If Elixir fails to build (specifically when pulling in a new version via
-`git`), be sure to remove any previous build artifacts by running
-`make clean`, then `make test`.
+However, if tests fail, it is likely you have an outdated Erlang version (Elixir requires Erlang 17.0 or later). You can check your Erlang version by calling `erl` in the command line. You will see some information as follows:
 
-If tests pass, you are ready to move on to the [Getting Started guide][1]
-or to try Interactive Elixir by running `bin/iex` in your terminal.
+    Erlang/OTP 17 [erts-6.0] [source-07b8f44] [64-bit] [smp:4:4] [async-threads:10] [hipe] [kernel-poll:false]
 
-However, if tests fail, it is likely you have an outdated Erlang version
-(Elixir requires Erlang 18.0 or later). You can check your Erlang version
-by calling `erl` in the command line. You will see some information as follows:
-
-    Erlang/OTP 18 [erts-7.0] [source] [smp:2:2] [async-threads:10] [hipe] [kernel-poll:false]
-
-If you have properly set up your dependencies and tests still fail,
-you may want to open up a bug report, as explained next.
-
-## Bug reports
-
-For reporting bugs, [visit our issues tracker][2] and follow the steps
-for reporting a new issue. Please disclose security vulnerabilities
-privately at elixir-security@googlegroups.com.
-
-## Contributing
-
-We welcome everyone to contribute to Elixir and help us tackle existing issues!
-To do so, there are a few things you need to know about the code. First, Elixir
-code is divided in applications inside the `lib` folder:
-
-* `elixir` - Contains Elixir's kernel and stdlib
-
-* `eex` - Template engine that allows you to embed Elixir
-
-* `ex_unit` - Simple test framework that ships with Elixir
-
-* `iex` - IEx, Elixir's interactive shell
-
-* `logger` - The built-in logger
-
-* `mix` - Elixir's build tool
-
-You can run all tests in the root directory with `make test` and you can
-also run tests for a specific framework `make test_#{NAME}`, for example,
-`make test_ex_unit`. If you just changed something in the Elixir's standard
-library, you can run only that portion through `make test_stdlib`, as
-`test_elixir` also runs tests for the other projects (EEx, ExUnit, etc.).
-
-In case you are changing a single file, you can compile and run tests only
-for that particular file for fast development cycles. For example, if you
-are changing the String module, you can compile it and run its tests as:
-
-```sh
-bin/elixirc lib/elixir/lib/string.ex -o lib/elixir/ebin
-bin/elixir lib/elixir/test/elixir/string_test.exs
-```
-
-To recompile (including Erlang modules):
-
-```sh
-make compile
-```
-
-If your contribution fails the build during the bootstrapping of the language,
-you can reproduce it locally by deleting all of Elixir beam files and compiling
-again:
-
-```sh
-make clean_elixir compile
-```
-
-Or to rebuild everything from scratch without running tests:
-
-```sh
-make clean compile
-```
-
-More tasks can be found by reading the [Makefile](./Makefile).
-
-After your changes are done, please remember to run the full suite with
-`make test`.
-
-From time to time, your tests may fail in an existing Elixir checkout and
-may require a clean start by running `make clean compile`. You can always
-check [the official build status on Travis-CI](https://travis-ci.org/elixir-lang/elixir).
-
-With tests running and passing, you are ready to contribute to Elixir and
-[send a pull request](https://help.github.com/articles/using-pull-requests/).
-We have saved some excellent pull requests we have received in the past in
-case you are looking for some examples:
-
-* [Implement Enum.member? – Pull Request](https://github.com/elixir-lang/elixir/pull/992)
-* [Add String.valid? – Pull Request](https://github.com/elixir-lang/elixir/pull/1058)
-* [Implement capture_io for ExUnit – Pull Request](https://github.com/elixir-lang/elixir/pull/1059)
-
-We usually keep a list of enhancements and bugs [in the issue tracker][2].
-For proposing new features, please start a discussion in the
-[Elixir Core mailing list][3]. Keep in mind that it is your responsibility
-to argue and explain why a feature is useful and how it will impact the
-codebase and the community. Finally, remember all interactions in our official
-spaces follow our [Code of Conduct][7].
-
-### Reviewing changes
-
-Once a pull request is sent, the Elixir team will review your changes.
-We outline our process below to clarify the roles of everyone involved.
-
-All pull requests must be approved by two committers before being merged into
-the repository. In case any changes are necessary, the team will leave
-appropriate comments requesting changes to the code.
-
-The Elixir team may optionally assign someone to review a pull request.
-In case someone is assigned, they must explicitly approve the code before
-another team member can merge it.
-
-When review is completed, your pull request will be squashed and merged
-into the repository.
+If you have the correct version and tests still fail, feel free to [open an issue][2].
 
 ## Building documentation
 
-Building the documentation requires [ExDoc](https://github.com/elixir-lang/ex_doc)
-to be installed and built alongside Elixir:
+Building the documentation requires [ex_doc](https://github.com/elixir-lang/ex_doc) to be installed and built in the same containing folder as elixir.
 
-```sh
-# After cloning and compiling Elixir, in its parent directory:
-git clone git://github.com/elixir-lang/ex_doc.git
-cd ex_doc && ../elixir/bin/mix do deps.get, compile
-cd ../elixir && make docs
-```
+    # After cloning and compiling Elixir
+    $ git clone git://github.com/elixir-lang/ex_doc.git
+    $ cd ex_doc && ../elixir/bin/mix compile
+    $ cd ../elixir && make docs
 
-This will produce documentation sets for `elixir`, `mix`, etc., under
-the `doc` directory. If you are planning to contribute documentation,
-[please check our best practices for writing documentation](https://hexdocs.pm/elixir/writing-documentation.html).
+## Contributing
 
-## Development links
+We appreciate any contribution to Elixir, so check out our [CONTRIBUTING.md](CONTRIBUTING.md) guide for more information. We usually keep a list of features and bugs [in the issue tracker][2].
 
-  * [Elixir Website][1]
-  * [Elixir Documentation][6]
-  * [Elixir Core Mailing list (development)][3]
-  * [Issues tracker][2]
-  * [Code of Conduct][7]
-  * **[#elixir-lang][4]** on [Freenode][5] IRC
+## Important links
+
+* \#elixir-lang on freenode IRC
+* [Website][1]
+* [Issue tracker][2]
+* [elixir-talk Mailing list (questions)][3]
+* [elixir-core Mailing list (development)][4]
 
   [1]: http://elixir-lang.org
   [2]: https://github.com/elixir-lang/elixir/issues
-  [3]: https://groups.google.com/group/elixir-lang-core
-  [4]: https://webchat.freenode.net/?channels=#elixir-lang
-  [5]: http://www.freenode.net
-  [6]: http://elixir-lang.org/docs.html
-  [7]: CODE_OF_CONDUCT.md
+  [3]: http://groups.google.com/group/elixir-lang-talk
+  [4]: http://groups.google.com/group/elixir-lang-core
 
 ## License
 
 "Elixir" and the Elixir logo are copyright (c) 2012 Plataformatec.
 
-Elixir source code is released under Apache 2 License.
+Elixir source code is released under Apache 2 License with some parts under Erlang's license (EPL).
 
-Check [NOTICE](NOTICE) and [LICENSE](LICENSE) files for more
-information.
+Check [LEGAL](LEGAL) and [LICENSE](LICENSE) files for more information.

RELEASE.md

@@ -10,26 +10,34 @@ This document simply outlines the release process:
 
 3. Ensure CHANGELOG is updated and add current date
 
-4. If a new `vMAJOR.MINOR`, replace "master" with "vVERSION" in the "Deprecations" page and commit
+4. Commit changes above with title "Release vVERSION" and generate new tag
 
-5. If a new `vMAJOR.MINOR`, create a new branch "vMAJOR.MINOR" and set `CANONICAL=` in Makefile
+5. Run `make clean test` to ensure all tests pass from scratch and the CI is green
 
-6. Commit changes above with title "Release vVERSION" and generate new tag
+6. Ensure minimum supported Hex works with new release (instructions upcoming)
 
-7. Run `make clean test` to ensure all tests pass from scratch and the CI is green
+7. Push master and the new tag
 
-8. Recompile an existing project (for example, Ecto) to ensure manifests can be upgraded
+8. Release new docs with `make release_docs`, move docs to `docs/stable` if appropriate, and push
 
-9. Push branch and the new tag
+9. Release new zip with `make release_zip`, push `Precompiled.zip` to GitHub Releases
 
-10. Publish new zips with `make zips`, upload `Precompiled.zip` and `Docs.zip` to GitHub Releases
+10. Add the release to `elixir.csv` file in `elixir-lang/elixir-lang.github.com`
 
-11. Add the release to `elixir.csv` and `_data/elixir-versions.yml` files in `elixir-lang/elixir-lang.github.com`
+11. Build and push standalone Mix with `make publish_mix` (requires AWS credentials)
 
-12. After a new `vMAJOR.MINOR`, move back to master, bump versions, start new CHANGELOG, add `-dev` back and commit "Start vMAJOR.MINOR+1"
+## New vMAJOR.MINOR releases
+
+11. Create a new branch "vMAJOR.MINOR"
+
+12. Move docs generation to `docs/vOLD-MAJOR.OLD-MINOR` and copy them to `docs/stable`
+
+13. Bump versions, start new CHANGELOG, add `-dev` back and commit "Start vVERSION+1"
+
+14. `make release_docs` and push it to `elixir-lang/docs`
 
 ## Places where version is mentioned
 
-* VERSION
+* VERSION (make sure there is no newline in this file)
 * CHANGELOG.md
 * src/elixir.app.src (not lib/elixir/src/elixir.app.src)

VERSION

@@ -1 +1 @@
-1.5.0
+1.0.2

bin/elixir

@@ -2,30 +2,25 @@
 if [ $# -eq 0 ] || [ "$1" = "--help" ] || [ "$1" = "-h" ]; then
   echo "Usage: `basename $0` [options] [.exs file] [data]
 
-  -e COMMAND                  Evaluates the given command (*)
-  -r FILE                     Requires the given files/patterns (*)
-  -S SCRIPT                   Finds and executes the given script in PATH
-  -pr FILE                    Requires the given files/patterns in parallel (*)
-  -pa PATH                    Prepends the given path to Erlang code path (*)
-  -pz PATH                    Appends the given path to Erlang code path (*)
-
-  --app APP                   Starts the given app and its dependencies (*)
-  --cookie COOKIE             Sets a cookie for this distributed node
-  --detached                  Starts the Erlang VM detached from console
-  --erl SWITCHES              Switches to be passed down to Erlang (*)
-  --help, -h                  Prints this message and exits
-  --hidden                    Makes a hidden node
-  --logger-otp-reports BOOL   Enables or disables OTP reporting
-  --logger-sasl-reports BOOL  Enables or disables SASL reporting
-  --name NAME                 Makes and assigns a name to the distributed node
-  --no-halt                   Does not halt the Erlang VM after execution
-  --sname NAME                Makes and assigns a short name to the distributed node
-  --version, -v               Prints Elixir version and exits
-  --werl                      Uses Erlang's Windows shell GUI (Windows only)
+  -v                Prints version and exit
+  -e \"command\"      Evaluates the given command (*)
+  -r \"file\"         Requires the given files/patterns (*)
+  -S \"script\"       Finds and executes the given script
+  -pr \"file\"        Requires the given files/patterns in parallel (*)
+  -pa \"path\"        Prepends the given path to Erlang code path (*)
+  -pz \"path\"        Appends the given path to Erlang code path (*)
+  --app \"app\"       Start the given app and its dependencies (*)
+  --erl \"switches\"  Switches to be passed down to erlang (*)
+  --name \"name\"     Makes and assigns a name to the distributed node
+  --sname \"name\"    Makes and assigns a short name to the distributed node
+  --cookie \"cookie\" Sets a cookie for this distributed node
+  --hidden          Makes a hidden node
+  --detached        Starts the Erlang VM detached from console
+  --no-halt         Does not halt the Erlang VM after execution
 
 ** Options marked with (*) can be given more than once
 ** Options given after the .exs file or -- are passed down to the executed code
-** Options can be passed to the Erlang runtime using ELIXIR_ERL_OPTIONS or --erl" >&2
+** Options can be passed to the erlang runtime using ELIXIR_ERL_OPTIONS or --erl" >&2
   exit 1
 fi
 
@@ -40,7 +35,6 @@ readlink_f () {
 }
 
 MODE="elixir"
-ERL_EXEC="erl"
 ERL=""
 I=1
 
@@ -72,28 +66,11 @@ while [ $I -le $# ]; do
         eval "VAL=\${$I}"
         ERL="$ERL `echo $PEEK | cut -c 2-` "$VAL""
         ;;
-    --logger-otp-reports)
-        I=$(expr $I + 1)
-        eval "VAL=\${$I}"
-        if [ "$VAL" = 'true' ] || [ "$VAL" = 'false' ]; then
-            ERL="$ERL -logger handle_otp_reports "$VAL""
-        fi
-        ;;
-    --logger-sasl-reports)
-        I=$(expr $I + 1)
-        eval "VAL=\${$I}"
-        if [ "$VAL" = 'true' ] || [ "$VAL" = 'false' ]; then
-            ERL="$ERL -logger handle_sasl_reports "$VAL""
-        fi
-        ;;
     --erl)
         I=$(expr $I + 1)
         eval "VAL=\${$I}"
         ERL="$ERL "$VAL""
         ;;
-    --werl)
-        USE_WERL=true
-        ;;
     *)
         break
         ;;
@@ -112,15 +89,11 @@ if [ "$OS" != "Windows_NT" ]; then
   if test -t 1 -a -t 2; then ERL="-elixir ansi_enabled true $ERL"; fi
 fi
 
-if [ "$OS" = "Windows_NT" ] && [ $USE_WERL ]; then
-    ERL_EXEC="werl"
-fi
-
 if [ -z "$ERL_PATH" ]; then
   if [ -f "$SCRIPT_PATH/../releases/RELEASES" ] && [ -f "$SCRIPT_PATH/erl" ]; then
-    ERL_PATH="$SCRIPT_PATH"/"$ERL_EXEC"
+    ERL_PATH="$SCRIPT_PATH"/erl
   else
-    ERL_PATH="$ERL_EXEC"
+    ERL_PATH=erl
   fi
 fi
 

bin/elixir.bat

@@ -1,39 +1,34 @@
-@if defined ELIXIR_CLI_ECHO (@echo on) else (@echo off)
+@echo off
 setlocal
-if    ""%1""==""""       goto documentation
-if /I ""%1""==""--help"" goto documentation
-if /I ""%1""==""-h""     goto documentation
-if /I ""%1""==""/h""     goto documentation
-if    ""%1""==""/?""     goto documentation
+if "%1"==""       goto documentation
+if "%1"=="--help" goto documentation
+if "%1"=="-h"     goto documentation
+if "%1"=="/h"     goto documentation
 goto parseopts
 
 :documentation
 echo Usage: %~nx0 [options] [.exs file] [data]
 echo.
-echo   -e COMMAND                  Evaluates the given command (*)
-echo   -r FILE                     Requires the given files/patterns (*)
-echo   -S SCRIPT                   Finds and executes the given script in PATH
-echo   -pr FILE                    Requires the given files/patterns in parallel (*)
-echo   -pa PATH                    Prepends the given path to Erlang code path (*)
-echo   -pz PATH                    Appends the given path to Erlang code path (*)
-echo.
-echo   --app APP                   Starts the given app and its dependencies (*)
-echo   --cookie COOKIE             Sets a cookie for this distributed node
-echo   --detached                  Starts the Erlang VM detached from console
-echo   --erl SWITCHES              Switches to be passed down to Erlang (*)
-echo   --help, -h                  Prints this message and exits
-echo   --hidden                    Makes a hidden node
-echo   --logger-otp-reports BOOL   Enables or disables OTP reporting
-echo   --logger-sasl-reports BOOL  Enables or disables SASL reporting
-echo   --name NAME                 Makes and assigns a name to the distributed node
-echo   --no-halt                   Does not halt the Erlang VM after execution
-echo   --sname NAME                Makes and assigns a short name to the distributed node
-echo   --version, -v               Prints Elixir version and exits
-echo   --werl                      Uses Erlang's Windows shell GUI
+echo   -v                Prints version and exit
+echo   -e command        Evaluates the given command (*)
+echo   -r file           Requires the given files/patterns (*)
+echo   -S script         Finds and executes the given script
+echo   -pr file          Requires the given files/patterns in parallel (*)
+echo   -pa path          Prepends the given path to Erlang code path (*)
+echo   -pz path          Appends the given path to Erlang code path (*)
+echo   --app app         Start the given app and its dependencies (*)
+echo   --erl switches    Switches to be passed down to erlang (*)
+echo   --name name       Makes and assigns a name to the distributed node
+echo   --sname name      Makes and assigns a short name to the distributed node
+echo   --cookie cookie   Sets a cookie for this distributed node
+echo   --hidden          Makes a hidden node
+echo   --detached        Starts the Erlang VM detached from console
+echo   --werl            Uses Erlang's Windows shell GUI
+echo   --no-halt         Does not halt the Erlang VM after execution
 echo.
 echo ** Options marked with (*) can be given more than once
 echo ** Options given after the .exs file or -- are passed down to the executed code
-echo ** Options can be passed to the Erlang runtime using ELIXIR_ERL_OPTIONS or --erl
+echo ** Options can be passed to the erlang runtime using ELIXIR_ERL_OPTIONS or --erl
 goto end
 
 :parseopts
@@ -62,53 +57,50 @@ set par="%1"
 shift
 if "%par%"=="" (
   rem if no parameters defined
-  goto expand_erl_libs
+  goto :expand_erl_libs
 )
 if "%par%"=="""" (
   rem if no parameters defined - special case for parameter that is already quoted
-  goto expand_erl_libs
+  goto :expand_erl_libs
 )
 rem ******* EXECUTION OPTIONS **********************
-if "%par%"==""--werl"" (set useWerl=1)
-if "%par%"==""+iex"" (set runMode="iex")
-rem ******* ELIXIR PARAMETERS **********************
+IF "%par%"==""--werl"" (Set useWerl=1)
+IF "%par%"==""+iex"" (Set runMode="iex")
+rem ******* elixir parameters **********************
 rem Note: we don't have to do anything with options that don't take an argument
-if """"=="%par:-e=%"      (shift)
-if """"=="%par:-r=%"      (shift)
-if """"=="%par:-pr=%"     (shift)
-if """"=="%par:-pa=%"     (shift)
-if """"=="%par:-pz=%"     (shift)
-if """"=="%par:--app=%"   (shift)
-if """"=="%par:--remsh=%" (shift)
+IF """"=="%par:-e=%"      (shift) 
+IF """"=="%par:-r=%"      (shift) 
+IF """"=="%par:-pr=%"     (shift) 
+IF """"=="%par:-pa=%"     (shift) 
+IF """"=="%par:-pz=%"     (shift) 
+IF """"=="%par:--app=%"   (shift) 
+IF """"=="%par:--remsh=%" (shift) 
 rem ******* ERLANG PARAMETERS **********************
-if """"=="%par:--detached=%"            (set parsErlang=%parsErlang% -detached)
-if """"=="%par:--hidden=%"              (set parsErlang=%parsErlang% -hidden)
-if """"=="%par:--cookie=%"              (set parsErlang=%parsErlang% -setcookie %1 && shift)
-if """"=="%par:--sname=%"               (set parsErlang=%parsErlang% -sname %1 && shift)
-if """"=="%par:--name=%"                (set parsErlang=%parsErlang% -name %1 && shift)
-if """"=="%par:--logger-otp-reports=%"  (set parsErlang=%parsErlang% -logger handle_otp_reports %1 && shift)
-if """"=="%par:--logger-sasl-reports=%" (set parsErlang=%parsErlang% -logger handle_sasl_reports %1 && shift)
-if """"=="%par:--erl=%"                 (set beforeExtra=%beforeExtra% %~1 && shift)
+IF """"=="%par:--detached=%" (Set parsErlang=%parsErlang% -detached) 
+IF """"=="%par:--hidden=%"   (Set parsErlang=%parsErlang% -hidden)
+IF """"=="%par:--cookie=%"   (Set parsErlang=%parsErlang% -setcookie %1 && shift)
+IF """"=="%par:--sname=%"    (Set parsErlang=%parsErlang% -sname %1 && shift) 
+IF """"=="%par:--name=%"     (Set parsErlang=%parsErlang% -name %1 && shift) 
+IF """"=="%par:--erl=%"      (Set beforeExtra=%beforeExtra% %~1 && shift) 
 goto:startloop
 
 rem ******* assume all pre-params are parsed ********************
 :expand_erl_libs
 rem ******* expand all ebin paths as Windows does not support the ..\*\ebin wildcard ********************
-setlocal enabledelayedexpansion
+SETLOCAL enabledelayedexpansion
 set ext_libs=
 for  /d %%d in ("%originPath%..\lib\*.") do (
   set ext_libs=!ext_libs! -pa "%%~fd\ebin"
 )
-setlocal disabledelayedexpansion
-
+SETLOCAL disabledelayedexpansion
 :run
-if not %runMode% == "iex" (
-  set beforeExtra=-noshell -s elixir start_cli %beforeExtra%
+IF NOT %runMode% == "iex" (
+  set beforeExtra=-s elixir start_cli %beforeExtra%
 )
-if %useWerl% equ 1 (
+IF %useWerl% EQU 1 (
   start werl.exe %ext_libs% %ELIXIR_ERL_OPTIONS% %parsErlang% %beforeExtra% -extra %*
-) else (
-  erl.exe %ext_libs% %ELIXIR_ERL_OPTIONS% %parsErlang% %beforeExtra% -extra %*
+) ELSE (
+  erl.exe %ext_libs% -noshell %ELIXIR_ERL_OPTIONS% %parsErlang% %beforeExtra% -extra %*
 )
 :end
 endlocal

bin/elixirc

@@ -2,19 +2,16 @@
 if [ $# -eq 0 ] || [ "$1" = "--help" ] || [ "$1" = "-h" ]; then
   echo "Usage: `basename $0` [elixir switches] [compiler switches] [.ex files]
 
-  -o                        The directory to output compiled files
-
-  --help, -h                Prints this message and exits
-  --ignore-module-conflict  Does not emit warnings if a module was previously defined
-  --no-debug-info           Does not attach debug info to compiled modules
-  --no-docs                 Does not attach documentation to compiled modules
-  --verbose                 Prints compilation status
-  --version, -v             Prints Elixir version and exits
-  --warnings-as-errors      Treats warnings as errors and return non-zero exit code
+  -o               The directory to output compiled files
+  --no-docs        Do not attach documentation to compiled modules
+  --no-debug-info  Do not attach debug info to compiled modules
+  --ignore-module-conflict
+  --warnings-as-errors Treat warnings as errors and return non-zero exit code
+  --verbose        Print informational messages.
 
 ** Options given after -- are passed down to the executed code
-** Options can be passed to the Erlang runtime using ELIXIR_ERL_OPTIONS
-** Options can be passed to the Erlang compiler using ERL_COMPILER_OPTIONS" >&2
+** Options can be passed to the erlang runtime using ELIXIR_ERL_OPTIONS
+** Options can be passed to the erlang compiler using ERL_COMPILER_OPTIONS" >&2
   exit 1
 fi
 

bin/elixirc.bat

@@ -1,12 +1,10 @@
-@if defined ELIXIR_CLI_ECHO (@echo on) else (@echo off)
-setlocal
+@echo off
 set argc=0
 for %%A in (%*) do (
-  if /I "%%A"=="--help" goto documentation
-  if /I "%%A"=="-h"     goto documentation
-  if /I "%%A"=="/h"     goto documentation
-  if    "%%A"=="/?"     goto documentation
-  set /A argc+=1
+    if "%%A"=="--help" goto documentation
+    if "%%A"=="-h"     goto documentation
+    if "%%A"=="/h"     goto documentation
+    set /A argc+=1
 )
 if %argc%==0 goto documentation
 goto run
@@ -14,23 +12,15 @@ goto run
 :documentation
 echo Usage: %~nx0 [elixir switches] [compiler switches] [.ex files]
 echo.
-echo   -o                        The directory to output compiled files
-echo.
-echo   --help, -h                Prints this message and exits
-echo   --ignore-module-conflict  Does not emit warnings if a module was previously defined
-echo   --no-debug-info           Does not attach debug info to compiled modules
-echo   --no-docs                 Does not attach documentation to compiled modules
-echo   --verbose                 Prints compilation status
-echo   --version, -v             Prints Elixir version and exits
-echo   --warnings-as-errors      Treats warnings as errors and returns non-zero exit code
+echo  -o               The directory to output compiled files
+echo  --no-docs        Do not attach documentation to compiled modules
+echo  --no-debug-info  Do not attach debug info to compiled modules
+echo  --ignore-module-conflict
+echo  --warnings-as-errors Treat warnings as errors and return non-zero exit code
+echo  --verbose        Print informational messages.
 echo.
 echo ** Options given after -- are passed down to the executed code
-echo ** Options can be passed to the Erlang runtime using ELIXIR_ERL_OPTIONS
-echo ** Options can be passed to the Erlang compiler using ERL_COMPILER_OPTIONS
-goto end
-
+echo ** Options can be passed to the erlang runtime using ELIXIR_ERL_OPTIONS
+echo ** Options can be passed to the erlang compiler using ERL_COMPILER_OPTIONS >&2
 :run
 call "%~dp0\elixir.bat" +elixirc %*
-
-:end
-endlocal

bin/iex

@@ -2,30 +2,23 @@
 if [ $# -gt 0 ] && ([ "$1" = "--help" ] || [ "$1" = "-h" ]); then
   echo "Usage: `basename $0` [options] [.exs file] [data]
 
-  -e COMMAND                  Evaluates the given command (*)
-  -r FILE                     Requires the given files/patterns (*)
-  -S SCRIPT                   Finds and executes the given script in PATH
-  -pr FILE                    Requires the given files/patterns in parallel (*)
-  -pa PATH                    Prepends the given path to Erlang code path (*)
-  -pz PATH                    Appends the given path to Erlang code path (*)
-
-  --app APP                   Starts the given app and its dependencies (*)
-  --cookie COOKIE             Sets a cookie for this distributed node
-  --detached                  Starts the Erlang VM detached from console
-  --erl SWITCHES              Switches to be passed down to Erlang (*)
-  --help, -h                  Prints this message and exits
-  --hidden                    Makes a hidden node
-  --logger-otp-reports BOOL   Enables or disables OTP reporting
-  --logger-sasl-reports BOOL  Enables or disables SASL reporting
-  --name NAME                 Makes and assigns a name to the distributed node
-  --no-halt                   Does not halt the Erlang VM after execution
-  --sname NAME                Makes and assigns a short name to the distributed node
-  --version, -v               Prints IEx version and exits
-  --werl                      Uses Erlang's Windows shell GUI (Windows only)
-
-  --dot-iex PATH              Overrides default .iex.exs file and uses path instead;
-                              path can be empty, then no file will be loaded
-  --remsh NAME                Connects to a node using a remote shell
+  -v                Prints version
+  -e \"command\"      Evaluates the given command (*)
+  -r \"file\"         Requires the given files/patterns (*)
+  -S \"script\"       Finds and executes the given script
+  -pr \"file\"        Requires the given files/patterns in parallel (*)
+  -pa \"path\"        Prepends the given path to Erlang code path (*)
+  -pz \"path\"        Appends the given path to Erlang code path (*)
+  --app \"app\"       Start the given app and its dependencies (*)
+  --erl \"switches\"  Switches to be passed down to erlang (*)
+  --name \"name\"     Makes and assigns a name to the distributed node
+  --sname \"name\"    Makes and assigns a short name to the distributed node
+  --cookie \"cookie\" Sets a cookie for this distributed node
+  --hidden          Makes a hidden node
+  --detached        Starts the Erlang VM detached from console
+  --remsh \"name\"    Connects to a node using a remote shell
+  --dot-iex \"path\"  Overrides default .iex.exs file and uses path instead;
+                    path can be empty, then no file will be loaded
 
 ** Options marked with (*) can be given more than once
 ** Options given after the .exs file or -- are passed down to the executed code
@@ -45,4 +38,6 @@ readlink_f () {
 
 SELF=$(readlink_f "$0")
 SCRIPT_PATH=$(dirname "$SELF")
-exec "$SCRIPT_PATH"/elixir --no-halt --erl "-noshell -user Elixir.IEx.CLI" +iex "$@"
+
+if [ "$OS" = "Windows_NT" ]; then NOSHELL="-noshell "; fi
+exec "$SCRIPT_PATH"/elixir --no-halt --erl "$NOSHELL -user Elixir.IEx.CLI" +iex "$@"

bin/iex.bat

@@ -1,46 +1,2 @@
-@if defined ELIXIR_CLI_ECHO (@echo on) else  (@echo off)
-setlocal
-if /I ""%1""==""--help"" goto documentation
-if /I ""%1""==""-h""     goto documentation
-if /I ""%1""==""/h""     goto documentation
-if    ""%1""==""/?""     goto documentation
-goto run
-
-:documentation
-echo Usage: %~nx0 [options] [.exs file] [data]
-echo.
-echo   -e COMMAND                  Evaluates the given command (*)
-echo   -r FILE                     Requires the given files/patterns (*)
-echo   -S SCRIPT                   Finds and executes the given script in PATH
-echo   -pr FILE                    Requires the given files/patterns in parallel (*)
-echo   -pa PATH                    Prepends the given path to Erlang code path (*)
-echo   -pz PATH                    Appends the given path to Erlang code path (*)
-echo.
-echo   --app APP                   Starts the given app and its dependencies (*)
-echo   --cookie COOKIE             Sets a cookie for this distributed node
-echo   --detached                  Starts the Erlang VM detached from console
-echo   --erl SWITCHES              Switches to be passed down to Erlang (*)
-echo   --help, -h                  Prints this message and exits
-echo   --hidden                    Makes a hidden node
-echo   --logger-otp-reports BOOL   Enables or disables OTP reporting
-echo   --logger-sasl-reports BOOL  Enables or disables SASL reporting
-echo   --name NAME                 Makes and assigns a name to the distributed node
-echo   --no-halt                   Does not halt the Erlang VM after execution
-echo   --sname NAME                Makes and assigns a short name to the distributed node
-echo   --version, -v               Prints IEx version and exits
-echo   --werl                      Uses Erlang's Windows shell GUI (Windows only)
-echo.
-echo   --dot-iex PATH              Overrides default .iex.exs file and uses path instead;
-echo                               path can be empty, then no file will be loaded
-echo   --remsh NAME                Connects to a node using a remote shell
-echo.
-echo ** Options marked with (*) can be given more than once
-echo ** Options given after the .exs file or -- are passed down to the executed code
-echo ** Options can be passed to the Erlang VM using ELIXIR_ERL_OPTIONS or --erl
-goto end
-
-:run
-@if defined IEX_WITH_WERL (@set __ELIXIR_IEX_FLAGS=--werl) else (set __ELIXIR_IEX_FLAGS=)
-call "%~dp0\elixir.bat" --no-halt --erl "-noshell -user Elixir.IEx.CLI" +iex %__ELIXIR_IEX_FLAGS% %*
-:end
-endlocal
+@echo off
+call "%~dp0\elixir.bat" +iex --erl "-user Elixir.IEx.CLI" --no-halt %*

bin/mix

@@ -1,3 +1,4 @@
 #!/usr/bin/env elixir
+# Reminder: apply any changes in this file to bin\mix.bat
 Mix.start
 Mix.CLI.main

bin/mix.bat

@@ -1,2 +1,2 @@
-@if defined ELIXIR_CLI_ECHO (@echo on) else (@echo off)
-call "%~dp0\elixir.bat" "%~dp0\mix" %*
+@echo off
+call "%~dp0\elixir.bat" -e Mix.start -e Mix.CLI.main %*

lib/eex/lib/eex.ex

@@ -9,7 +9,7 @@ end
 defmodule EEx do
   @moduledoc ~S"""
   EEx stands for Embedded Elixir. It allows you to embed
-  Elixir code inside a string in a robust way.
+  Elixir code inside a string in a robust way:
 
       iex> EEx.eval_string "foo <%= bar %>", [bar: "baz"]
       "foo baz"
@@ -35,14 +35,13 @@ defmodule EEx do
 
   ## Options
 
-  All functions in this module accept EEx-related options.
+  All functions in this module accepts EEx-related options.
   They are:
 
     * `:line` - the line to be used as the template start. Defaults to 1.
     * `:file` - the file to be used in the template. Defaults to the given
       file the template is read from or to "nofile" when compiling from a string.
     * `:engine` - the EEx engine to be used for compilation.
-    * `:trim` - trims whitespace left/right of quotation tags
 
   ## Engine
 
@@ -63,9 +62,9 @@ defmodule EEx do
 
   All expressions that output something to the template
   **must** use the equals sign (`=`). Since everything in
-  Elixir is an expression, there are no exceptions for this rule.
-  For example, while some template languages would special-case
-  `if/2` clauses, they are treated the same in EEx and
+  Elixir is a macro, there are no exceptions for this rule.
+  For example, while some template languages would special-
+  case `if` clauses, they are treated the same in EEx and
   also require `=` in order to have their result printed:
 
       <%= if true do %>
@@ -86,11 +85,11 @@ defmodule EEx do
       iex> EEx.eval_string "<%= @foo %>", assigns: [foo: 1]
       "1"
 
-  In other words, `<%= @foo %>` translates to:
+  In other words, `<%= @foo %>` is simply translated to:
 
-      <%= {:ok, v} = Access.fetch(assigns, :foo); v %>
+      <%= Dict.get assigns, :foo %>
 
-  The `assigns` extension is useful when the number of variables
+  The assigns extension is useful when the number of variables
   required by the template is not specified at compilation time.
   """
 
@@ -111,7 +110,7 @@ defmodule EEx do
 
   """
   defmacro function_from_string(kind, name, source, args \\ [], options \\ []) do
-    quote bind_quoted: binding() do
+    quote bind_quoted: binding do
       info = Keyword.merge [file: __ENV__.file, line: __ENV__.line], options
       args = Enum.map args, fn arg -> {arg, [line: info[:line]], nil} end
       compiled = EEx.compile_string(source, info)
@@ -148,7 +147,7 @@ defmodule EEx do
 
   """
   defmacro function_from_file(kind, name, file, args \\ [], options \\ []) do
-    quote bind_quoted: binding() do
+    quote bind_quoted: binding do
       info = Keyword.merge options, [file: file, line: 1]
       args = Enum.map args, fn arg -> {arg, [line: 1], nil} end
       compiled = EEx.compile_file(file, info)
@@ -163,26 +162,24 @@ defmodule EEx do
   end
 
   @doc """
-  Gets a string `source` and generate a quoted expression
+  Get a string `source` and generate a quoted expression
   that can be evaluated by Elixir or compiled to a function.
   """
-  @spec compile_string(String.t, keyword) :: Macro.t | no_return
-  def compile_string(source, options \\ []) when is_binary(source) and is_list(options) do
+  def compile_string(source, options \\ []) do
     EEx.Compiler.compile(source, options)
   end
 
   @doc """
-  Gets a `filename` and generate a quoted expression
+  Get a `filename` and generate a quoted expression
   that can be evaluated by Elixir or compiled to a function.
   """
-  @spec compile_file(String.t, keyword) :: Macro.t | no_return
-  def compile_file(filename, options \\ []) when is_binary(filename) and is_list(options) do
+  def compile_file(filename, options \\ []) do
     options = Keyword.merge options, [file: filename, line: 1]
     compile_string(File.read!(filename), options)
   end
 
   @doc """
-  Gets a string `source` and evaluate the values using the `bindings`.
+  Get a string `source` and evaluate the values using the `bindings`.
 
   ## Examples
 
@@ -190,28 +187,24 @@ defmodule EEx do
       "foo baz"
 
   """
-  @spec eval_string(String.t, keyword, keyword) :: any
-  def eval_string(source, bindings \\ [], options \\ [])
-      when is_binary(source) and is_list(bindings) and is_list(options) do
+  def eval_string(source, bindings \\ [], options \\ []) do
     compiled = compile_string(source, options)
     do_eval(compiled, bindings, options)
   end
 
   @doc """
-  Gets a `filename` and evaluate the values using the `bindings`.
+  Get a `filename` and evaluate the values using the `bindings`.
 
   ## Examples
 
-      # sample.eex
+      # sample.ex
       foo <%= bar %>
 
       # iex
-      EEx.eval_file "sample.eex", [bar: "baz"] #=> "foo baz"
+      EEx.eval_file "sample.ex", [bar: "baz"] #=> "foo baz"
 
   """
-  @spec eval_file(String.t, keyword, keyword) :: any
-  def eval_file(filename, bindings \\ [], options \\ [])
-      when is_binary(filename) and is_list(bindings) and is_list(options) do
+  def eval_file(filename, bindings \\ [], options \\ []) do
     options  = Keyword.put options, :file, filename
     compiled = compile_file(filename, options)
     do_eval(compiled, bindings, options)

lib/eex/lib/eex/compiler.ex

@@ -9,78 +9,54 @@ defmodule EEx.Compiler do
   and the engine together by handling the tokens and invoking
   the engine every time a full expression or text is received.
   """
-  @spec compile(String.t, keyword) :: Macro.t | no_return
-  def compile(source, opts) when is_binary(source) and is_list(opts) do
-    file = opts[:file] || "nofile"
-    line = opts[:line] || 1
-    trim = opts[:trim] || false
-    case EEx.Tokenizer.tokenize(source, line, trim: trim) do
+  def compile(source, opts) do
+    file   = opts[:file] || "nofile"
+    line   = opts[:line] || 1
+    case EEx.Tokenizer.tokenize(source, line) do
       {:ok, tokens} ->
-        state = %{engine: opts[:engine] || @default_engine, init: nil,
+        state = %{engine: opts[:engine] || @default_engine,
                   file: file, line: line, quoted: [], start_line: nil}
-        init = state.engine.init(opts)
-        generate_buffer(tokens, init, [], %{state | init: init})
+        generate_buffer(tokens, "", [], state)
       {:error, line, message} ->
         raise EEx.SyntaxError, line: line, file: file, message: message
     end
   end
 
-  # Generates the buffers by handling each expression from the tokenizer.
-  # It returns Macro.t/0 or it raises.
+  # Generates the buffers by handling each expression from the tokenizer
 
-  defp generate_buffer([{:text, chars} | rest], buffer, scope, state) do
+  defp generate_buffer([{:text, chars}|t], buffer, scope, state) do
     buffer = state.engine.handle_text(buffer, IO.chardata_to_string(chars))
-    generate_buffer(rest, buffer, scope, state)
+    generate_buffer(t, buffer, scope, state)
   end
 
-  defp generate_buffer([{:expr, line, mark, chars} | rest], buffer, scope, state) do
+  defp generate_buffer([{:expr, line, mark, chars}|t], buffer, scope, state) do
     expr = Code.string_to_quoted!(chars, [line: line, file: state.file])
-    buffer = state.engine.handle_expr(buffer, IO.chardata_to_string(mark), expr)
-    generate_buffer(rest, buffer, scope, state)
+    buffer = state.engine.handle_expr(buffer, mark, expr)
+    generate_buffer(t, buffer, scope, state)
   end
 
-  defp generate_buffer([{:start_expr, start_line, mark, chars} | rest], buffer, scope, state) do
-    {contents, line, rest} = look_ahead_text(rest, start_line, chars)
-    {contents, rest} =
-      generate_buffer(rest, state.init, [contents | scope],
-                      %{state | quoted: [], line: line, start_line: start_line})
-    buffer = state.engine.handle_expr(buffer, IO.chardata_to_string(mark), contents)
-    generate_buffer(rest, buffer, scope, state)
+  defp generate_buffer([{:start_expr, start_line, mark, chars}|t], buffer, scope, state) do
+    {contents, line, t} = look_ahead_text(t, start_line, chars)
+    {contents, t} = generate_buffer(t, "", [contents|scope],
+                                    %{state | quoted: [], line: line, start_line: start_line})
+    buffer = state.engine.handle_expr(buffer, mark, contents)
+    generate_buffer(t, buffer, scope, state)
   end
 
-  defp generate_buffer([{:middle_expr, line, '', chars} | rest], buffer, [current | scope], state) do
+  defp generate_buffer([{:middle_expr, line, _, chars}|t], buffer, [current|scope], state) do
     {wrapped, state} = wrap_expr(current, line, buffer, chars, state)
-    generate_buffer(rest, state.init, [wrapped | scope], %{state | line: line})
+    generate_buffer(t, "", [wrapped|scope], %{state | line: line})
   end
 
-  defp generate_buffer([{:middle_expr, line, modifier, chars} | t], buffer, scope, state) do
-    message = "unexpected beginning of EEx tag \"<%#{modifier}\" on \"<%#{modifier}#{chars}%>\", " <>
-              "please remove \"#{modifier}\" accordingly"
-    :elixir_errors.warn line, state.file, message
-    generate_buffer([{:middle_expr, line, '', chars} | t], buffer, scope, state)
-    # TODO: Make this an error on Elixir v2.0 since it accidentally worked previously.
-    # raise EEx.SyntaxError, message: message, file: state.file, line: line
-  end
-
-  defp generate_buffer([{:end_expr, line, '', chars} | rest], buffer, [current | _], state) do
+  defp generate_buffer([{:end_expr, line, _, chars}|t], buffer, [current|_], state) do
     {wrapped, state} = wrap_expr(current, line, buffer, chars, state)
     tuples = Code.string_to_quoted!(wrapped, [line: state.start_line, file: state.file])
     buffer = insert_quoted(tuples, state.quoted)
-    {buffer, rest}
+    {buffer, t}
   end
 
-  defp generate_buffer([{:end_expr, line, modifier, chars} | t], buffer, [_ | _] = scope, state) do
-    message = "unexpected beginning of EEx tag \"<%#{modifier}\" on end of expression \"<%#{modifier}#{chars}%>\", " <>
-              "please remove \"#{modifier}\" accordingly"
-    :elixir_errors.warn line, state.file, message
-    generate_buffer([{:end_expr, line, '', chars} | t], buffer, scope, state)
-    # TODO: Make this an error on Elixir v2.0 since it accidentally worked previously.
-    # raise EEx.SyntaxError, message: message, file: state.file, line: line
-  end
-
-  defp generate_buffer([{:end_expr, line, _, chars} | _], _buffer, [], state) do
-    raise EEx.SyntaxError, message: "unexpected end of expression <%#{chars}%>",
-                           file: state.file, line: line
+  defp generate_buffer([{:end_expr, line, _, chars}|_], _buffer, [], state) do
+    raise EEx.SyntaxError, message: "unexpected token #{inspect chars}", file: state.file, line: line
   end
 
   defp generate_buffer([], buffer, [], state) do
@@ -97,25 +73,23 @@ defmodule EEx.Compiler do
   defp wrap_expr(current, line, buffer, chars, state) do
     new_lines = List.duplicate(?\n, line - state.line)
     key = length(state.quoted)
-    placeholder = '__EEX__(' ++ Integer.to_charlist(key) ++ ');'
+    placeholder = '__EEX__(' ++ Integer.to_char_list(key) ++ ');'
     {current ++ placeholder ++ new_lines ++ chars,
-     %{state | quoted: [{key, buffer} | state.quoted]}}
+     %{state | quoted: [{key, buffer}|state.quoted]}}
   end
 
   # Look text ahead on expressions
 
-  defp look_ahead_text([{:text, text}, {:middle_expr, line, _, chars} | rest] = tokens, start, contents) do
+  defp look_ahead_text([{:text, text}, {:middle_expr, line, _, chars}|t]=list, start, contents) do
     if only_spaces?(text) do
-      {contents ++ text ++ chars, line, rest}
+      {contents ++ text ++ chars, line, t}
     else
-      {contents, start, tokens}
+      {contents, start, list}
     end
   end
-  defp look_ahead_text([{:middle_expr, line, _, chars} | rest], _start, contents) do
-    {contents ++ chars, line, rest}
-  end
-  defp look_ahead_text(tokens, start, contents) do
-    {contents, start, tokens}
+
+  defp look_ahead_text(t, start, contents) do
+    {contents, start, t}
   end
 
   defp only_spaces?(chars) do

lib/eex/lib/eex/engine.ex

@@ -2,9 +2,7 @@ defmodule EEx.Engine do
   @moduledoc ~S"""
   Basic EEx engine that ships with Elixir.
 
-  An engine needs to implement four functions:
-
-    * `init(opts)` - returns the initial buffer
+  An engine needs to implement three functions:
 
     * `handle_body(quoted)` - receives the final built quoted
       expression, should do final post-processing and return a
@@ -27,44 +25,38 @@ defmodule EEx.Engine do
   default implementations for the functions above.
   """
 
-  @callback init(opts :: keyword) :: Macro.t
-  @callback handle_body(quoted :: Macro.t) :: Macro.t
-  @callback handle_text(buffer :: Macro.t, text :: String.t) :: Macro.t
-  @callback handle_expr(buffer :: Macro.t, marker :: String.t, expr :: Macro.t) :: Macro.t
+  use Behaviour
+
+  defcallback handle_body(Macro.t) :: Macro.t
+  defcallback handle_text(Macro.t, binary) :: Macro.t
+  defcallback handle_expr(Macro.t, binary, Macro.t) :: Macro.t
 
   @doc false
   defmacro __using__(_) do
     quote do
       @behaviour EEx.Engine
 
-      def init(opts) do
-        EEx.Engine.init(opts)
-      end
-
-      def handle_body(quoted) do
-        EEx.Engine.handle_body(quoted)
+      def handle_body(body) do
+        EEx.Engine.handle_body(body)
       end
 
       def handle_text(buffer, text) do
         EEx.Engine.handle_text(buffer, text)
       end
 
-      def handle_expr(buffer, marker, expr) do
-        EEx.Engine.handle_expr(buffer, marker, expr)
+      def handle_expr(buffer, mark, expr) do
+        EEx.Engine.handle_expr(buffer, mark, expr)
       end
 
-      defoverridable EEx.Engine
+      defoverridable [handle_body: 1, handle_expr: 3, handle_text: 2]
     end
   end
 
   @doc """
   Handles assigns in quoted expressions.
 
-  A warning will be printed on missing assigns.
-  Future versions will raise.
-
   This can be added to any custom engine by invoking
-  `handle_assign/1` with `Macro.prewalk/2`:
+  `handle_assign/3` with `Macro.prewalk/1`:
 
       def handle_expr(buffer, token, expr) do
         expr = Macro.prewalk(expr, &EEx.Engine.handle_assign/1)
@@ -72,40 +64,18 @@ defmodule EEx.Engine do
       end
 
   """
-  @spec handle_assign(Macro.t) :: Macro.t
   def handle_assign({:@, meta, [{name, _, atom}]}) when is_atom(name) and is_atom(atom) do
     line = meta[:line] || 0
-    quote line: line, do: EEx.Engine.fetch_assign!(var!(assigns), unquote(name))
+    quote line: line, do: Dict.get(var!(assigns), unquote(name))
   end
+
   def handle_assign(arg) do
     arg
   end
 
-  @doc false
-  # TODO: Raise on 2.0
-  @spec fetch_assign!(Access.t, Access.key) :: term | nil
-  def fetch_assign!(assigns, key) do
-    case Access.fetch(assigns, key) do
-      {:ok, val} ->
-        val
-      :error ->
-        keys = Enum.map(assigns, &elem(&1, 0))
-        IO.warn "assign @#{key} not available in EEx template. " <>
-                "Please ensure all assigns are given as options. " <>
-                "Available assigns: #{inspect keys}"
-        nil
-    end
-  end
-
   @doc """
-  Returns an empty string as initial buffer.
-  """
-  def init(_opts) do
-    ""
-  end
-
-  @doc """
-  The default implementation simply returns the given expression.
+  The default implementation implementation simply returns the
+  given expression.
   """
   def handle_body(quoted) do
     quoted
@@ -128,16 +98,16 @@ defmodule EEx.Engine do
   """
   def handle_expr(buffer, "=", expr) do
     quote do
-      tmp1 = unquote(buffer)
-      tmp1 <> String.Chars.to_string(unquote(expr))
+      tmp = unquote(buffer)
+      tmp <> String.Chars.to_string(unquote(expr))
     end
   end
 
   def handle_expr(buffer, "", expr) do
     quote do
-      tmp2 = unquote(buffer)
+      tmp = unquote(buffer)
       unquote(expr)
-      tmp2
+      tmp
     end
   end
 end

lib/eex/lib/eex/smart_engine.ex

@@ -11,9 +11,9 @@ defmodule EEx.SmartEngine do
       "1"
 
   In the example above, we can access the value `foo` under
-  the binding `assigns` using `@foo`. This is useful because
-  a template, after being compiled, can receive different
-  assigns and would not require recompilation for each
+  the binding `assigns` using `@foo`. This is useful when
+  a template, after compiled, may receive different assigns
+  and the developer don't want to recompile it for each
   variable set.
 
   Assigns can also be used when compiled to a function:

lib/eex/lib/eex/tokenizer.ex

@@ -1,98 +1,90 @@
 defmodule EEx.Tokenizer do
   @moduledoc false
 
-  @type content :: IO.chardata
-  @type line :: non_neg_integer
-  @type token :: {:text, content} |
-                 {:expr | :start_expr | :middle_expr | :end_expr, line, '=' | '', content}
-
   @doc """
-  Tokenizes the given charlist or binary.
+  Tokenizes the given char list or binary.
 
   It returns {:ok, list} with the following tokens:
 
-    * `{:text, content}`
-    * `{:expr, line, marker, content}`
-    * `{:start_expr, line, marker, content}`
-    * `{:middle_expr, line, marker, content}`
-    * `{:end_expr, line, marker, content}`
+    * `{:text, contents}`
+    * `{:expr, line, marker, contents}`
+    * `{:start_expr, line, marker, contents}`
+    * `{:middle_expr, line, marker, contents}`
+    * `{:end_expr, line, marker, contents}`
 
   Or `{:error, line, error}` in case of errors.
   """
-  @spec tokenize(binary | charlist, line, keyword) :: {:ok, [token]} | {:error, line, String.t}
-  def tokenize(bin, line, opts \\ [])
-
-  def tokenize(bin, line, opts)
-      when is_binary(bin) and is_integer(line) and line >= 0 and is_list(opts) do
-    tokenize(String.to_charlist(bin), line, opts)
+  def tokenize(bin, line) when is_binary(bin) do
+    tokenize(String.to_char_list(bin), line)
   end
 
-  def tokenize(list, line, opts)
-      when is_list(list) and is_integer(line) and line >= 0 and is_list(opts) do
-    tokenize(list, line, opts, [], [])
+  def tokenize(list, line) do
+    tokenize(list, line, [], [])
   end
 
-  defp tokenize('<%%' ++ t, line, opts, buffer, acc) do
-   tokenize t, line, opts, [?%, ?< | buffer], acc
-  end
-
-  defp tokenize('<%#' ++ t, line, opts, buffer, acc) do
-    case expr(t, line, []) do
+  defp tokenize('<%%' ++ t, line, buffer, acc) do
+    case expr(t, line, [?%, ?<|buffer]) do
       {:error, _, _} = error -> error
-      {:ok, _, new_line, rest} ->
-        {rest, new_line, buffer} = trim_if_needed(rest, new_line, opts, buffer, acc)
-        tokenize rest, new_line, opts, buffer, acc
+      {:ok, buffer, new_line, rest} ->
+        tokenize rest, new_line, [?>, ?%|buffer], acc
     end
   end
 
-  defp tokenize('<%' ++ t, line, opts, buffer, acc) do
+  defp tokenize('<%#' ++ t, line, buffer, acc) do
+    case expr(t, line, []) do
+      {:error, _, _} = error -> error
+      {:ok, _, new_line, rest} ->
+        tokenize rest, new_line, buffer, acc
+    end
+  end
+
+  defp tokenize('<%' ++ t, line, buffer, acc) do
     {marker, t} = retrieve_marker(t)
 
     case expr(t, line, []) do
       {:error, _, _} = error -> error
       {:ok, expr, new_line, rest} ->
         token = token_name(expr)
-        {rest, new_line, buffer} = trim_if_needed(rest, new_line, opts, buffer, acc)
         acc   = tokenize_text(buffer, acc)
         final = {token, line, marker, Enum.reverse(expr)}
-        tokenize rest, new_line, opts, [], [final | acc]
+        tokenize rest, new_line, [], [final | acc]
     end
   end
 
-  defp tokenize('\n' ++ t, line, opts, buffer, acc) do
-    tokenize t, line + 1, opts, [?\n | buffer], acc
+  defp tokenize('\n' ++ t, line, buffer, acc) do
+    tokenize t, line + 1, [?\n|buffer], acc
   end
 
-  defp tokenize([h | t], line, opts, buffer, acc) do
-    tokenize t, line, opts, [h | buffer], acc
+  defp tokenize([h|t], line, buffer, acc) do
+    tokenize t, line, [h|buffer], acc
   end
 
-  defp tokenize([], _line, _opts, buffer, acc) do
+  defp tokenize([], _line, buffer, acc) do
     {:ok, Enum.reverse(tokenize_text(buffer, acc))}
   end
 
   # Retrieve marker for <%
 
   defp retrieve_marker('=' ++ t) do
-    {'=', t}
+    {"=", t}
   end
 
   defp retrieve_marker(t) do
-    {'', t}
+    {"", t}
   end
 
   # Tokenize an expression until we find %>
 
-  defp expr([?%, ?> | t], line, buffer) do
+  defp expr([?%, ?>|t], line, buffer) do
     {:ok, buffer, line, t}
   end
 
   defp expr('\n' ++ t, line, buffer) do
-    expr t, line + 1, [?\n | buffer]
+    expr t, line + 1, [?\n|buffer]
   end
 
-  defp expr([h | t], line, buffer) do
-    expr t, line, [h | buffer]
+  defp expr([h|t], line, buffer) do
+    expr t, line, [h|buffer]
   end
 
   defp expr([], line, _buffer) do
@@ -102,15 +94,15 @@ defmodule EEx.Tokenizer do
   # Receive an expression content and check
   # if it is a start, middle or an end token.
   #
-  # Start tokens finish with "do" and "fn ->"
-  # Middle tokens are marked with "->" or keywords
-  # End tokens contain only the end word and optionally ")"
+  # Start tokens finish with `do` and `fn ->`
+  # Middle tokens are marked with `->` or keywords
+  # End tokens contain only the end word
 
-  defp token_name([h | t]) when h in [?\s, ?\t, ?)] do
+  defp token_name([h|t]) when h in [?\s, ?\t] do
     token_name(t)
   end
 
-  defp token_name('od' ++ [h | _]) when h in [?\s, ?\t, ?)] do
+  defp token_name('od' ++ [h|_]) when h in [?\s, ?\t, ?)] do
     :start_expr
   end
 
@@ -123,7 +115,7 @@ defmodule EEx.Tokenizer do
     # token and, if so, it is not followed by an "end"
     # token. If this is the case, we are on a start expr.
     case :elixir_tokenizer.tokenize(rest, 1, file: "eex", check_terminators: false) do
-      {:ok, _line, _column, tokens} ->
+      {:ok, _line, tokens} ->
         tokens   = Enum.reverse(tokens)
         fn_index = fn_index(tokens)
 
@@ -151,7 +143,7 @@ defmodule EEx.Tokenizer do
     Enum.find_index tokens, fn
       {:fn_paren, _} -> true
       {:fn, _}       -> true
-      _              -> false
+      _                -> false
     end
   end
 
@@ -177,46 +169,4 @@ defmodule EEx.Tokenizer do
   defp tokenize_text(buffer, acc) do
     [{:text, Enum.reverse(buffer)} | acc]
   end
-
-  # If trim mode is enabled and the token is on a line with
-  # only itself and whitespace, trim the whitespace around it,
-  # including the line break following it if there is one.
-  defp trim_if_needed(rest, line, opts, buffer, acc) do
-    original = {rest, line, buffer}
-    if opts[:trim] do
-      case {trim_left(buffer, acc), trim_right(rest, line)} do
-        {{true, new_buffer}, {true, new_rest, new_line}} ->
-          {new_rest, new_line, new_buffer}
-        _ ->
-          original
-      end
-    else
-      original
-    end
-  end
-
-  defp trim_left(buffer, acc) do
-    case {trim_whitespace(buffer), acc} do
-      {[?\n | _] = trimmed_buffer, _} -> {true, trimmed_buffer}
-      {[], []} -> {true, []}
-      _ -> {false, buffer}
-    end
-  end
-
-  defp trim_right(rest, line) do
-    case trim_whitespace(rest) do
-      [?\r, ?\n | trimmed_rest] -> {true, trimmed_rest, line + 1}
-      [?\n | trimmed_rest] -> {true, trimmed_rest, line + 1}
-      [] -> {true, [], line}
-      _ -> {false, rest, line}
-    end
-  end
-
-  defp trim_whitespace([h | t]) when h == ?\s or h == ?\t do
-    trim_whitespace(t)
-  end
-
-  defp trim_whitespace(list) do
-    list
-  end
 end

lib/eex/mix.exs

@@ -2,10 +2,8 @@ defmodule EEx.Mixfile do
   use Mix.Project
 
   def project do
-    [
-      app: :eex,
-      version: System.version,
-      build_per_environment: false
-    ]
+    [app: :eex,
+     version: System.version,
+     build_per_environment: false]
   end
 end

lib/eex/test/eex/smart_engine_test.exs

@@ -1,8 +1,7 @@
 Code.require_file "../test_helper.exs", __DIR__
 
 defmodule EEx.SmartEngineTest do
-  # TODO: Make this async: true once capture_io is removed
-  use ExUnit.Case
+  use ExUnit.Case, async: true
 
   test "evaluates simple string" do
     assert_eval "foo bar", "foo bar"
@@ -16,18 +15,11 @@ defmodule EEx.SmartEngineTest do
     assert_eval "1", "<%= @foo %>", assigns: %{foo: 1}
   end
 
-  test "error with missing assigns" do
-    stderr = ExUnit.CaptureIO.capture_io(:stderr, fn ->
-      assert_eval "", "<%= @foo %>", assigns: %{}
-    end)
-    assert stderr =~ "assign @foo not available in EEx template"
-  end
-
   test "evaluates with loops" do
     assert_eval "1\n2\n3\n", "<%= for x <- [1, 2, 3] do %><%= x %>\n<% end %>"
   end
 
-  test "preserves line numbers" do
+  test "compiled preserved line numbers" do
     result = EEx.compile_string("<%= @hello %>", engine: EEx.SmartEngine)
     Macro.prewalk(result, fn
       {_left, meta, _right} ->
@@ -38,7 +30,7 @@ defmodule EEx.SmartEngineTest do
   end
 
   defp assert_eval(expected, actual, binding \\ []) do
-    result = EEx.eval_string(actual, binding, file: __ENV__.file, engine: EEx.SmartEngine)
+    result = EEx.eval_string(actual, binding, file: __ENV__.file)
     assert result == expected
   end
 end

lib/eex/test/eex/tokenizer_test.exs

@@ -14,17 +14,17 @@ defmodule EEx.TokenizerTest do
 
   test "strings with embedded code" do
     assert T.tokenize('foo <% bar %>', 1) ==
-           {:ok, [{:text, 'foo '}, {:expr, 1, '', ' bar '}]}
+           {:ok, [{:text, 'foo '}, {:expr, 1, "", ' bar '}]}
   end
 
   test "strings with embedded equals code" do
     assert T.tokenize('foo <%= bar %>', 1) ==
-           {:ok, [{:text, 'foo '}, {:expr, 1, '=', ' bar '}]}
+           {:ok, [{:text, 'foo '}, {:expr, 1, "=", ' bar '}]}
   end
 
   test "strings with more than one line" do
     assert T.tokenize('foo\n<%= bar %>', 1) ==
-           {:ok, [{:text, 'foo\n'}, {:expr, 2, '=', ' bar '}]}
+           {:ok, [{:text, 'foo\n'}, {:expr, 2, "=", ' bar '}]}
   end
 
   test "strings with more than one line and expression with more than one line" do
@@ -37,9 +37,9 @@ baz %>
 
     assert T.tokenize(string, 1) == {:ok, [
       {:text, 'foo '},
-      {:expr, 1, '=', ' bar\n\nbaz '},
+      {:expr, 1, "=", ' bar\n\nbaz '},
       {:text, '\n'},
-      {:expr, 4, '', ' foo '},
+      {:expr, 4, "", ' foo '},
       {:text, '\n'}
     ]}
   end
@@ -56,20 +56,6 @@ baz %>
     ]}
   end
 
-  test "quotation with interpolation" do
-    assert T.tokenize('a <%% b <%= c %> <%= d %> e %> f', 1) == {:ok, [
-      {:text, 'a <% b '},
-      {:expr, 1, '=', ' c '},
-      {:text, ' '},
-      {:expr, 1, '=', ' d '},
-      {:text, ' e %> f'}
-    ]}
-
-    assert T.tokenize('<%%% a <%%= b %> c %>', 1) == {:ok, [
-      {:text, '<%% a <%= b %> c %>'}
-    ]}
-  end
-
   test "comments" do
     assert T.tokenize('foo <%# true %>', 1) == {:ok, [
       {:text, 'foo '}
@@ -85,79 +71,36 @@ baz %>
   test "strings with embedded do end" do
     assert T.tokenize('foo <% if true do %>bar<% end %>', 1) == {:ok, [
       {:text, 'foo '},
-      {:start_expr, 1, '', ' if true do '},
+      {:start_expr, 1, "", ' if true do '},
       {:text, 'bar'},
-      {:end_expr, 1, '', ' end '}
+      {:end_expr, 1, "", ' end '}
     ]}
   end
 
   test "strings with embedded -> end" do
     assert T.tokenize('foo <% cond do %><% false -> %>bar<% true -> %>baz<% end %>', 1) == {:ok, [
       {:text, 'foo '},
-      {:start_expr, 1, '', ' cond do '},
-      {:middle_expr, 1, '', ' false -> '},
+      {:start_expr, 1, "", ' cond do '},
+      {:middle_expr, 1, "", ' false -> '},
       {:text, 'bar'},
-      {:middle_expr, 1, '', ' true -> '},
+      {:middle_expr, 1, "", ' true -> '},
       {:text, 'baz'},
-      {:end_expr, 1, '', ' end '}
+      {:end_expr, 1, "", ' end '}
     ]}
   end
 
   test "strings with embedded keywords blocks" do
     assert T.tokenize('foo <% if true do %>bar<% else %>baz<% end %>', 1) == {:ok, [
       {:text, 'foo '},
-      {:start_expr, 1, '', ' if true do '},
+      {:start_expr, 1, "", ' if true do '},
       {:text, 'bar'},
-      {:middle_expr, 1, '', ' else '},
+      {:middle_expr, 1, "", ' else '},
       {:text, 'baz'},
-      {:end_expr, 1, '', ' end '}
+      {:end_expr, 1, "", ' end '}
     ]}
   end
 
-  test "trim mode" do
-    template = '\t<%= if true do %> \n TRUE \n  <% else %>\n FALSE \n  <% end %>  '
-    assert T.tokenize(template, 1, trim: true) == {:ok, [
-      {:start_expr, 1, '=', ' if true do '},
-      {:text, ' TRUE \n'},
-      {:middle_expr, 3, '', ' else '},
-      {:text, ' FALSE \n'},
-      {:end_expr, 5, '', ' end '}
-    ]}
-  end
-
-  test "trim mode with comment" do
-    assert T.tokenize('  <%# comment %>  \n123', 1, trim: true) == {:ok, [
-      {:text, '123'}
-    ]}
-  end
-
-  test "trim mode with CRLF" do
-    assert T.tokenize('0\r\n  <%= 12 %>  \r\n34', 1, trim: true) == {:ok, [
-      {:text, '0\r\n'},
-      {:expr, 2, '=', ' 12 '},
-      {:text, '34'}
-    ]}
-  end
-
-  test "trim mode set to false" do
-    assert T.tokenize(' <%= 12 %> \n', 1, trim: false) == {:ok, [
-      {:text, ' '},
-      {:expr, 1, '=', ' 12 '},
-      {:text, ' \n'}
-    ]}
-  end
-
-  test "trim mode no false positives" do
-    assert_not_trimmed = fn x -> assert T.tokenize(x, 1, trim: true) == T.tokenize(x, 1) end
-
-    assert_not_trimmed.('foo <%= "bar" %>  ')
-    assert_not_trimmed.('\n  <%= "foo" %>bar')
-    assert_not_trimmed.('  <%% hello %>  ')
-    assert_not_trimmed.('  <%= 01 %><%= 23 %>\n')
-  end
-
   test "raise syntax error when there is start mark and no end mark" do
     assert T.tokenize('foo <% :bar', 1) == {:error, 1, "missing token '%>'"}
-    assert T.tokenize('<%# true ', 1) == {:error, 1, "missing token '%>'"}
   end
 end

lib/eex/test/eex_test.exs

@@ -4,7 +4,7 @@ require EEx
 
 defmodule EExTest.Compiled do
   def before_compile do
-    fill_in_stacktrace()
+    fill_in_stacktrace
     {__ENV__.line, hd(tl(System.stacktrace))}
   end
 
@@ -19,13 +19,13 @@ defmodule EExTest.Compiled do
   def file_sample(arg), do: private_file_sample(arg)
 
   def after_compile do
-    fill_in_stacktrace()
+    fill_in_stacktrace
     {__ENV__.line, hd(tl(System.stacktrace))}
   end
 
   @file "unknown"
   def unknown do
-    fill_in_stacktrace()
+    fill_in_stacktrace
     {__ENV__.line, hd(tl(System.stacktrace))}
   end
 
@@ -53,392 +53,323 @@ defmodule EExTest do
   doctest EEx.Engine
   doctest EEx.SmartEngine
 
-  describe "evaluates" do
-    test "simple string" do
-      assert_eval "foo bar", "foo bar"
-    end
+  test "evaluates simple string" do
+    assert_eval "foo bar", "foo bar"
+  end
 
-    test "Unicode" do
-      template = """
-        • <%= "•" %> •
-        <%= "Jößé Vâlìm" %> Jößé Vâlìm
-      """
-      assert_eval "  • • •\n  Jößé Vâlìm Jößé Vâlìm\n", template
-    end
+  test "evaluates with embedded" do
+    assert_eval "foo bar", "foo <%= :bar %>"
+  end
 
-    test "trim mode" do
-      string = "<%= 123 %> \n456\n  <%= 789 %>"
-      expected = "123456\n789"
-      assert_eval expected, string, [], trim: true
-    end
+  test "evaluates with embedded and the binding" do
+    assert EEx.eval_string("foo <%= bar %>", [bar: 1]) == "foo 1"
+  end
 
-    test "trim mode with middle expression" do
-      string = """
-      <%= cond do %>
-      <% false -> %>
-        this
-      <% true -> %>
-        that
-      <% end %>
-      """
-      expected = "  that\n"
-      assert_eval expected, string, [], trim: true
-    end
+  test "evaluates with embedded do end" do
+    assert_eval "foo bar", "foo <%= if true do %>bar<% end %>"
+  end
 
-    test "embedded code" do
-      assert_eval "foo bar", "foo <%= :bar %>"
-    end
+  test "evaluates with embedded do end and eval the expression" do
+    assert_eval "foo ", "foo <%= if false do %>bar<% end %>"
+  end
 
-    test "embedded code with binding" do
-      assert EEx.eval_string("foo <%= bar %>", [bar: 1]) == "foo 1"
-    end
+  test "evaluates with embedded do end and nested print expression" do
+    assert_eval "foo bar", "foo <%= if true do %><%= :bar %><% end %>"
+  end
 
-    test "embedded code with do end when true" do
-      assert_eval "foo bar", "foo <%= if true do %>bar<% end %>"
-    end
+  test "evaluates with embedded do end and nested expressions" do
+    assert_eval "foo bar baz", "foo <%= if true do %>bar <% Process.put(:eex_text, 1) %><%= :baz %><% end %>"
+    assert Process.get(:eex_text) == 1
+  end
 
-    test "embedded code with do end when false" do
-      assert_eval "foo ", "foo <%= if false do %>bar<% end %>"
-    end
+  test "evaluates with embedded middle expression" do
+    assert_eval "foo bar", "foo <%= if true do %>bar<% else %>baz<% end %>"
+  end
 
-    test "embedded code with do end and expression" do
-      assert_eval "foo bar", "foo <%= if true do %><%= :bar %><% end %>"
-    end
+  test "evaluates with embedded middle expression and eval the expression" do
+    assert_eval "foo baz", "foo <%= if false do %>bar<% else %>baz<% end %>"
+  end
 
-    test "embedded code with do end and multiple expressions" do
-      assert_eval "foo bar baz", "foo <%= if true do %>bar <% Process.put(:eex_text, 1) %><%= :baz %><% end %>"
-      assert Process.get(:eex_text) == 1
-    end
+  test "evaluates with nested start expression" do
+    assert_eval "foo bar", "foo <%= if true do %><%= if true do %>bar<% end %><% end %>"
+  end
 
-    test "embedded code with middle expression" do
-      assert_eval "foo bar", "foo <%= if true do %>bar<% else %>baz<% end %>"
-    end
+  test "evaluates with nested middle expression" do
+    assert_eval "foo baz", "foo <%= if true do %><%= if false do %>bar<% else %>baz<% end %><% end %>"
+  end
 
-    test "embedded code with evaluated middle expression" do
-      assert_eval "foo baz", "foo <%= if false do %>bar<% else %>baz<% end %>"
-    end
+  test "evaluates with defined variable" do
+    assert_eval "foo 1", "foo <% bar = 1 %><%= bar %>"
+  end
 
-    test "embedded code with nested do end" do
-      assert_eval "foo bar", "foo <%= if true do %><%= if true do %>bar<% end %><% end %>"
-    end
+  test "evaluates with require code" do
+    assert_eval "foo 1,2,3", "foo <% require Enum, as: E %><%= E.join [1, 2, 3], \",\" %>"
+  end
 
-    test "embedded code with nested do end with middle expression" do
-      assert_eval "foo baz", "foo <%= if true do %><%= if false do %>bar<% else %>baz<% end %><% end %>"
-    end
+  test "evaluates with end of token" do
+    assert_eval "foo bar %>", "foo bar %>"
+  end
 
-    test "embedded code with parentheses after end in end token" do
-      assert_eval " 101  102  103 ", "<%= Enum.map([1, 2, 3], (fn x -> %> <%= 100 + x %> <% end) ) %>"
-    end
-
-    test "embedded code with variable definition" do
-      assert_eval "foo 1", "foo <% bar = 1 %><%= bar %>"
-    end
-
-    test "embedded code with require" do
-      assert_eval "foo 1,2,3", "foo <% require Enum, as: E %><%= E.join [1, 2, 3], \",\" %>"
-    end
-
-    test "with end of token" do
-      assert_eval "foo bar %>", "foo bar %>"
+  test "raises a syntax error when the token is invalid" do
+    assert_raise EEx.SyntaxError, "nofile:1: missing token '%>'", fn ->
+      EEx.compile_string "foo <%= bar"
     end
   end
 
-  describe "raises syntax errors" do
-    test "when the token is invalid" do
-      assert_raise EEx.SyntaxError, "nofile:1: missing token '%>'", fn ->
-        EEx.compile_string "foo <%= bar"
-      end
-    end
-
-    test "when end expression is found without a start expression" do
-      assert_raise EEx.SyntaxError, "nofile:1: unexpected end of expression <% end %>",  fn ->
-        EEx.compile_string "foo <% end %>"
-      end
-    end
-
-    test "when start expression is found without an end expression" do
-      assert_raise EEx.SyntaxError, "nofile:2: unexpected end of string, expected a closing '<% end %>'", fn ->
-        EEx.compile_string "foo\n<% if true do %>"
-      end
-    end
-
-    test "when nested end expression is found without a start expression" do
-      assert_raise EEx.SyntaxError, "nofile:1: unexpected end of expression <% end %>", fn ->
-        EEx.compile_string "foo <% if true do %><% end %><% end %>"
-      end
-    end
-
-    test "when middle expression has a modifier" do
-      assert ExUnit.CaptureIO.capture_io(:stderr, fn ->
-        EEx.compile_string "foo <%= if true do %>true<%= else %>false<% end %>"
-      end) =~ ~s[unexpected beginning of EEx tag \"<%=\" on \"<%= else %>\"]
-    end
-
-    test "when end expression has a modifier" do
-      assert ExUnit.CaptureIO.capture_io(:stderr, fn ->
-        EEx.compile_string "foo <%= if true do %>true<% else %>false<%= end %>"
-      end) =~ ~s[unexpected beginning of EEx tag \"<%=\" on end of expression \"<%= end %>\"]
+  test "raises a syntax error when end expression is found without a start expression" do
+    assert_raise EEx.SyntaxError, "nofile:1: unexpected token ' end '",  fn ->
+      EEx.compile_string "foo <% end %>"
     end
   end
 
-  describe "environment" do
-    test "respects line numbers" do
-      expected = """
-      foo
-      2
-      """
-
-      string = """
-      foo
-      <%= __ENV__.line %>
-      """
-
-      assert_eval expected, string
-    end
-
-    test "respects line numbers inside nested expressions" do
-      expected = """
-      foo
-
-      3
-
-      5
-      """
-
-      string = """
-      foo
-      <%= if true do %>
-      <%= __ENV__.line %>
-      <% end %>
-      <%= __ENV__.line %>
-      """
-
-      assert_eval expected, string
-    end
-
-    test "respects line numbers inside start expression" do
-      expected = """
-      foo
-
-      true
-
-      5
-      """
-
-      string = """
-      foo
-      <%= if __ENV__.line == 2 do %>
-      <%= true %>
-      <% end %>
-      <%= __ENV__.line %>
-      """
-
-      assert_eval expected, string
-    end
-
-    test "respects line numbers inside middle expression with ->" do
-      expected = """
-      foo
-
-      true
-
-      7
-      """
-
-      string = """
-      foo
-      <%= cond do %>
-      <% false -> %> false
-      <% __ENV__.line == 4 -> %>
-      <%= true %>
-      <% end %>
-      <%= __ENV__.line %>
-      """
-
-      assert_eval expected, string
-    end
-
-    test "respects line number inside middle expressions with keywords" do
-      expected = """
-      foo
-
-      5
-
-      7
-      """
-
-      string = """
-      foo
-      <%= if false do %>
-      <%= __ENV__.line %>
-      <% else %>
-      <%= __ENV__.line %>
-      <% end %>
-      <%= __ENV__.line %>
-      """
-
-      assert_eval expected, string
-    end
-
-    test "respects files" do
-      assert_eval "sample.ex", "<%= __ENV__.file %>", [], file: "sample.ex"
+  test "raises a syntax error when start expression is found without an end expression" do
+    assert_raise EEx.SyntaxError, "nofile:2: unexpected end of string, expected a closing '<% end %>'", fn ->
+      EEx.compile_string "foo\n<% if true do %>"
     end
   end
 
-  describe "clauses" do
-    test "inside functions" do
-      expected = """
-
-      Number 1
-
-      Number 2
-
-      Number 3
-
-      """
-
-      string = """
-      <%= Enum.map [1, 2, 3], fn x -> %>
-      Number <%= x %>
-      <% end %>
-      """
-
-      assert_eval expected, string
-    end
-
-    test "inside cond" do
-      expected = """
-      foo
-
-      true
-
-      """
-
-      string = """
-      foo
-      <%= cond do %>
-      <% false -> %> false
-      <% fn -> 1 end -> %>
-      <%= true %>
-      <% end %>
-      """
-
-      assert_eval expected, string
-    end
-
-    test "inside cond with do end" do
-      string = """
-      <% y = ["a", "b", "c"] %>
-      <%= cond do %>
-       <% "a" in y -> %>
-        Good
-       <% true -> %>
-        <% if true do %>true<% else %>false<% end %>
-        Bad
-      <% end %>
-      """
-
-      assert_eval "\n\n  Good\n \n", string
+  test "raises a syntax error when nested end expression is found without a start expression" do
+    assert_raise EEx.SyntaxError, "nofile:1: unexpected token ' end '", fn ->
+      EEx.compile_string "foo <% if true do %><% end %><% end %>"
     end
   end
 
-  describe "buffers" do
-    test "unused buffers are kept out" do
-      string = """
-      <%= 123 %>
-      <% if true do %>
-        <%= 456 %>
-      <% end %>
-      <%= 789 %>
-      """
+  test "respects line numbers" do
+    expected = """
+foo
+2
+"""
 
-      assert_eval "123\n\n789\n", string
-    end
+    string = """
+foo
+<%= __ENV__.line %>
+"""
 
-    test "inside comprehensions" do
-      string = """
-      <%= for _name <- packages || [] do %>
-      <% end %>
-      <%= all || :done %>
-      """
-      assert_eval "\ndone\n", string, packages: nil, all: nil
+    assert_eval expected, string
+  end
+
+  test "respects line numbers inside nested expressions" do
+    expected = """
+foo
+
+3
+
+5
+"""
+
+    string = """
+foo
+<%= if true do %>
+<%= __ENV__.line %>
+<% end %>
+<%= __ENV__.line %>
+"""
+
+    assert_eval expected, string
+  end
+
+  test "respects line numbers inside start expression" do
+    expected = """
+foo
+
+true
+
+5
+"""
+
+    string = """
+foo
+<%= if __ENV__.line == 2 do %>
+<%= true %>
+<% end %>
+<%= __ENV__.line %>
+"""
+
+    assert_eval expected, string
+  end
+
+  test "respects line numbers inside middle expression with ->" do
+    expected = """
+foo
+
+true
+
+7
+"""
+
+    string = """
+foo
+<%= cond do %>
+<% false -> %> false
+<% __ENV__.line == 4 -> %>
+<%= true %>
+<% end %>
+<%= __ENV__.line %>
+"""
+
+    assert_eval expected, string
+  end
+
+  test "respects line number inside middle expressions with keywords" do
+    expected = """
+foo
+
+5
+
+7
+"""
+
+    string = """
+foo
+<%= if false do %>
+<%= __ENV__.line %>
+<% else %>
+<%= __ENV__.line %>
+<% end %>
+<%= __ENV__.line %>
+"""
+
+    assert_eval expected, string
+  end
+
+  test "properly handle functions" do
+    expected = """
+
+Number 1
+
+Number 2
+
+Number 3
+
+"""
+
+    string = """
+<%= Enum.map [1, 2, 3], fn x -> %>
+Number <%= x %>
+<% end %>
+"""
+
+    assert_eval expected, string
+  end
+
+  test "do not consider already finished functions" do
+    expected = """
+foo
+
+true
+
+"""
+
+    string = """
+foo
+<%= cond do %>
+<% false -> %> false
+<% fn -> 1 end -> %>
+<%= true %>
+<% end %>
+"""
+
+    assert_eval expected, string
+  end
+
+  test "evaluates nested do expressions" do
+    string = """
+    <% y = ["a", "b", "c"] %>
+    <%= cond do %>
+     <% "a" in y -> %>
+      Good
+     <% true -> %>
+      <% if true do %>true<% else %>false<% end %>
+      Bad
+    <% end %>
+    """
+
+    assert_eval "\n\n  Good\n \n", string
+  end
+
+  test "for comprehensions" do
+    string = """
+    <%= for _name <- packages || [] do %>
+    <% end %>
+    <%= all || :done %>
+    """
+    assert_eval "\ndone\n", string, packages: nil, all: nil
+  end
+
+  test "unicode" do
+    template = """
+      • <%= "•" %> •
+      <%= "Jößé Vâlìm" %> Jößé Vâlìm
+    """
+    result = EEx.eval_string(template)
+    assert result == "  • • •\n  Jößé Vâlìm Jößé Vâlìm\n"
+  end
+
+  test "evaluates the source from a given file" do
+    filename = Path.join(__DIR__, "fixtures/eex_template.eex")
+    result = EEx.eval_file(filename)
+    assert result == "foo bar.\n"
+  end
+
+  test "evaluates the source from a given file with bindings" do
+    filename = Path.join(__DIR__, "fixtures/eex_template_with_bindings.eex")
+    result = EEx.eval_file(filename, [bar: 1])
+    assert result == "foo 1\n"
+  end
+
+  test "raises an Exception when there's an error with the given file" do
+    assert_raise File.Error, "could not read file non-existent.eex: no such file or directory", fn ->
+      filename = "non-existent.eex"
+      EEx.compile_file(filename)
     end
   end
 
-  describe "from file" do
-    test "evaluates the source" do
-      filename = Path.join(__DIR__, "fixtures/eex_template.eex")
-      result = EEx.eval_file(filename)
-      assert_normalized_newline_equal "foo bar.\n", result
-    end
-
-    test "evaluates the source with bindings" do
-      filename = Path.join(__DIR__, "fixtures/eex_template_with_bindings.eex")
-      result = EEx.eval_file(filename, [bar: 1])
-      assert_normalized_newline_equal "foo 1\n", result
-    end
-
-    test "raises an Exception when file is missing" do
-      assert_raise File.Error, "could not read file \"non-existent.eex\": no such file or directory", fn ->
-        filename = "non-existent.eex"
-        EEx.compile_file(filename)
-      end
-    end
-
-    test "sets external resource attribute" do
-      assert EExTest.Compiled.__info__(:attributes)[:external_resource] ==
-             [Path.join(__DIR__, "fixtures/eex_template_with_bindings.eex")]
-    end
+  test "sets external resource attribute" do
+    assert EExTest.Compiled.__info__(:attributes)[:external_resource] ==
+           [Path.join(__DIR__, "fixtures/eex_template_with_bindings.eex")]
   end
 
-  describe "precompiled" do
+  test "defined from string" do
+    assert EExTest.Compiled.string_sample(1, 2) == "3"
+  end
 
-    test "from string" do
-      assert EExTest.Compiled.string_sample(1, 2) == "3"
-    end
+  test "defined from file" do
+    assert EExTest.Compiled.file_sample(1) == "foo 1\n"
+    assert EExTest.Compiled.public_file_sample(1) == "foo 1\n"
+  end
 
-    test "from file" do
-      assert_normalized_newline_equal "foo 1\n", EExTest.Compiled.file_sample(1)
-      assert_normalized_newline_equal "foo 1\n", EExTest.Compiled.public_file_sample(1)
-    end
-
-    test "from file does not affect backtrace" do
-      assert EExTest.Compiled.before_compile ==
-        {8,
-          {EExTest.Compiled,
-            :before_compile,
-            0,
-            [file: to_charlist(Path.relative_to_cwd(__ENV__.file)), line: 7]
-         }
+  test "defined from file do not affect backtrace" do
+    assert EExTest.Compiled.before_compile ==
+      {8,
+        {EExTest.Compiled,
+          :before_compile,
+          0,
+          [file: to_char_list(Path.relative_to_cwd(__ENV__.file)), line: 7]
        }
+     }
 
-      assert EExTest.Compiled.after_compile ==
-        {23,
-          {EExTest.Compiled,
-            :after_compile,
-            0,
-            [file: to_charlist(Path.relative_to_cwd(__ENV__.file)), line: 22]
-         }
+    assert EExTest.Compiled.after_compile ==
+      {23,
+        {EExTest.Compiled,
+          :after_compile,
+          0,
+          [file: to_char_list(Path.relative_to_cwd(__ENV__.file)), line: 22]
        }
+     }
 
-      assert EExTest.Compiled.unknown ==
-        {29,
-          {EExTest.Compiled,
-            :unknown,
-            0,
-            [file: 'unknown', line: 28]
-         }
+    assert EExTest.Compiled.unknown ==
+      {29,
+        {EExTest.Compiled,
+          :unknown,
+          0,
+          [file: 'unknown', line: 28]
        }
-    end
+     }
   end
 
   defmodule TestEngine do
     @behaviour EEx.Engine
 
-    def init(_opts) do
-      ""
-    end
-
     def handle_body(body) do
       {:wrapped, body}
     end
@@ -452,19 +383,12 @@ defmodule EExTest do
     end
   end
 
-  describe "custom engines" do
-    test "calls handle_body" do
-      assert {:wrapped, "foo"} = EEx.eval_string("foo", [], engine: TestEngine)
-    end
+  test "calls handle_body" do
+    assert {:wrapped, "foo"} = EEx.eval_string("foo", [], engine: TestEngine)
   end
 
-  defp assert_eval(expected, actual, binding \\ [], opts \\ []) do
-    opts = Enum.into [file: __ENV__.file, engine: EEx.Engine], opts
-    result = EEx.eval_string(actual, binding, opts)
+  defp assert_eval(expected, actual, binding \\ []) do
+    result = EEx.eval_string(actual, binding, file: __ENV__.file, engine: EEx.Engine)
     assert result == expected
   end
-
-  defp assert_normalized_newline_equal(expected, actual) do
-    assert String.replace(expected, "\r\n", "\n") == String.replace(actual, "\r\n", "\n")
-  end
 end

lib/eex/test/test_helper.exs

@@ -1 +1 @@
-ExUnit.start [trace: "--trace" in System.argv]
+ExUnit.start [trace: "--trace" in System.argv]

lib/elixir/lib/access.ex

@@ -1,23 +1,15 @@
-defmodule Access do
+defprotocol Access do
   @moduledoc """
-  Key-based access to data structures using the `data[key]` syntax.
+  The Access protocol is used by `foo[bar]` and also
+  empowers the nested update functions in Kernel.
 
-  Elixir provides two syntaxes for accessing values. `user[:name]`
-  is used by dynamic structures, like maps and keywords, while
-  `user.name` is used by structs. The main difference is that
-  `user[:name]` won't raise if the key `:name` is missing but
-  `user.name` will raise if there is no `:name` key.
+  For instance, `foo[bar]` translates `Access.get(foo, bar)`.
+  `Kernel.get_in/2`, `Kernel.put_in/3`, `Kernel.update_in/3` and
+  `Kernel.get_and_update_in/3` are also all powered by the Access
+  protocol.
 
-  Besides the cases above, this module provides convenience
-  functions for accessing other structures, like `at/1` for
-  lists and `elem/1` for tuples. Those functions can be used
-  by the nested update functions in `Kernel`, such as
-  `Kernel.get_in/2`, `Kernel.put_in/3`, `Kernel.update_in/3`,
-  `Kernel.get_and_update_in/3` and friends.
-
-  ## Dynamic lookups
-
-  Out of the box, `Access` works with `Keyword` and `Map`:
+  This protocol is implemented by default for keywords, maps
+  and dictionary like types:
 
       iex> keywords = [a: 1, b: 2]
       iex> keywords[:a]
@@ -31,340 +23,113 @@ defmodule Access do
       iex> star_ratings[1.5]
       "★☆"
 
-  Note that the dynamic lookup syntax (`term[key]`) roughly translates to
-  `Access.get(term, key, nil)`.
-
-  `Access` can be combined with `Kernel.put_in/3` to put a value
-  in a given key:
-
-      iex> map = %{a: 1, b: 2}
-      iex> put_in map[:a], 3
-      %{a: 3, b: 2}
-
-  This syntax is very convenient as it can be nested arbitrarily:
-
-      iex> users = %{"john" => %{age: 27}, "meg" => %{age: 23}}
-      iex> put_in users["john"][:age], 28
-      %{"john" => %{age: 28}, "meg" => %{age: 23}}
-
-  Furthermore, `Access` transparently ignores `nil` values:
-
-      iex> keywords = [a: 1, b: 2]
-      iex> keywords[:c][:unknown]
-      nil
-
-  Since `Access` is a behaviour, it can be implemented for key-value
-  data structures. The implementation should be added to the
-  module that defines the struct being accessed. `Access` requires the
-  key comparison to be implemented using the `===` operator.
-
-  ## Static lookups
-
-  The `Access` syntax (`data[key]`) cannot be used to access fields in
-  structs, since structs do not implement the `Access` behaviour by
-  default. It is also a design decision: the dynamic access lookup
-  is meant to be used for dynamic key-value structures, like maps
-  and keywords, and not by static ones like structs (where fields are
-  known and not dynamic).
-
-  Therefore Elixir provides a static lookup for struct fields and for atom
-  fields in maps. Imagine a struct named `User` with a `:name` field.
-  The following would raise:
-
-      user = %User{name: "John"}
-      user[:name]
-      # ** (UndefinedFunctionError) undefined function User.fetch/2 (User does not implement the Access behaviour)
-
-  Structs instead use the `user.name` syntax to access fields:
-
-      user.name
-      #=> "John"
-
-  The same `user.name` syntax can also be used by `Kernel.put_in/2`
-  for updating structs fields:
-
-      put_in user.name, "Mary"
-      #=> %User{name: "Mary"}
-
-  Differently from `user[:name]`, `user.name` is not extensible via
-  a behaviour and is restricted only to structs and atom keys in maps.
-
-  As mentioned above, this works for atom keys in maps as well. Refer to the
-  `Map` module for more information on this.
-
-  Summing up:
-
-    * `user[:name]` is used by dynamic structures, is extensible and
-      does not raise on missing keys
-    * `user.name` is used by static structures, it is not extensible
-      and it will raise on missing keys
-
-  ## Accessors
-
-  While Elixir provides built-in syntax only for traversing dynamic
-  and static key-value structures, this module provides convenience
-  functions for traversing other structures, like tuples and lists,
-  to be used alongside `Kernel.put_in/2` in others.
-
-  For instance, given a user map with `:name` and `:languages` keys, here is how
-  to deeply traverse the map and convert all language names to uppercase:
-
-      iex> languages = [
-      ...>   %{name: "elixir", type: :functional},
-      ...>   %{name: "c", type: :procedural},
-      ...> ]
-      iex> user = %{name: "john", languages: languages}
-      iex> update_in user, [:languages, Access.all(), :name], &String.upcase/1
-      %{name: "john",
-        languages: [%{name: "ELIXIR", type: :functional},
-                    %{name: "C", type: :procedural}]}
-
-  See the functions `key/1`, `key!/1`, `elem/1`, and `all/0` for some of the
-  available accessors.
-
-  ## Implementing the Access behaviour for custom data structures
-
-  In order to be able to use the `Access` behaviour with custom data structures
-  (which have to be structs), such structures have to implement the `Access`
-  behaviour. For example, for a `User` struct, this would have to be done:
-
-      defmodule User do
-        defstruct [:name, :email]
-
-        @behaviour Access
-        # Implementation of the Access callbacks...
-      end
-
+  The key comparison must be implemented using the `===` operator.
   """
 
-  @type container :: keyword | struct | map
-  @type nil_container :: nil
-  @type any_container :: any
-  @type t :: container | nil_container | any_container
-  @type key :: any
-  @type value :: any
-
-  @type get_fun(data, get_value) ::
-        (:get, data, (term -> term) ->
-        {get_value, new_data :: container})
-
-  @type get_and_update_fun(data, get_value) ::
-        (:get_and_update, data, (term -> term) ->
-        {get_value, new_data :: container} | :pop)
-
-  @type access_fun(data, get_value) ::
-        get_fun(data, get_value) | get_and_update_fun(data, get_value)
-
   @doc """
-  Invoked in order to access the value stored under `key` in the given term `term`.
-
-  This function should return `{:ok, value}` where `value` is the value under
-  `key` if the key exists in the term, or `:error` if the key does not exist in
-  the term.
-
-  Many of the functions defined in the `Access` module internally call this
-  function. This function is also used when the square-brackets access syntax
-  (`structure[key]`) is used: the `fetch/2` callback implemented by the module
-  that defines the `structure` struct is invoked and if it returns `{:ok,
-  value}` then `value` is returned, or if it returns `:error` then `nil` is
-  returned.
-
-  See the `Map.fetch/2` and `Keyword.fetch/2` implementations for examples of
-  how to implement this callback.
+  Accesses the given key in the container.
   """
-  @callback fetch(term :: t, key) :: {:ok, value} | :error
+  @spec get(t, term) :: t
+  def get(container, key)
 
   @doc """
-  Invoked in order to access the value stored under `key` in the given term `term`,
-  defaulting to `default` if not present.
+  Gets a value and updates the given `key` in one pass.
 
-  This function should return the value under `key` in `term` if there's
-  such key, otherwise `default`.
-
-  For most data structures, this can be implemented using `fetch/2` internally;
-  for example:
-
-      def get(structure, key, default) do
-        case fetch(structure, key) do
-          {:ok, value} -> value
-          :error       -> default
-        end
-      end
-
-  See the `Map.get/3` and `Keyword.get/3` implementations for examples of
-  how to implement this callback.
+  The function must receive the value for the given `key`
+  (or `nil` if the key doesn't exist in `container`) and
+  the function must return a tuple containing the `get`
+  value and the new value to be stored in the `container`.
   """
-  @callback get(term :: t, key, default :: value) :: value
-
-  @doc """
-  Invoked in order to access the value under `key` and update it at the same time.
-
-  The implementation of this callback should invoke `fun` with the value under
-  `key` in the passed structure `data`, or with `nil` if `key` is not present in it.
-  This function must return either `{get_value, update_value}` or `:pop`.
-
-  If the passed function returns `{get_value, update_value}`,
-  the return value of this callback should be `{get_value, new_data}`, where:
-  - `get_value` is the retrieved value (which can be operated on before being returned)
-  - `update_value` is the new value to be stored under `key`
-  - `new_data` is `data` after updating the value of `key` with `update_value`.
-
-  If the passed function returns `:pop`, the return value of this callback
-  must be `{value, new_data}` where `value` is the value under `key`
-  (or `nil` if not present) and `new_data` is `data` without `key`.
-
-  See the implementations of `Map.get_and_update/3` or `Keyword.get_and_update/3`
-  for more examples.
-  """
-  @callback get_and_update(data, key, (value -> {get_value, value} | :pop)) ::
-            {get_value, data} when get_value: var, data: container | any_container
-
-  @doc """
-  Invoked to "pop" the value under `key` out of the given data structure.
-
-  When `key` exists in the given structure `data`, the implementation should
-  return a `{value, new_data}` tuple where `value` is the value that was under
-  `key` and `new_data` is `term` without `key`.
-
-  When `key` is not present in the given structure, a tuple `{value, data}`
-  should be returned, where `value` is implementation-defined.
-
-  See the implementations for `Map.pop/3` or `Keyword.pop/3` for more examples.
-  """
-  @callback pop(data, key) :: {value, data} when data: container | any_container
-
-  defmacrop raise_undefined_behaviour(e, struct, top) do
-    quote do
-      stacktrace = System.stacktrace
-      e =
-        case stacktrace do
-          [unquote(top) | _] ->
-            %{unquote(e) | reason: "#{inspect unquote(struct)} does not implement the Access behaviour"}
-          _ ->
-            unquote(e)
-        end
-      reraise e, stacktrace
-    end
-  end
-
-  @doc """
-  Fetches the value for the given key in a container (a map, keyword
-  list, or struct that implements the `Access` behaviour).
-
-  Returns `{:ok, value}` where `value` is the value under `key` if there is such
-  a key, or `:error` if `key` is not found.
-  """
-  @spec fetch(container, term) :: {:ok, term} | :error
-  @spec fetch(nil_container, any) :: :error
-  def fetch(container, key)
-
-  def fetch(%struct{} = container, key) do
-    struct.fetch(container, key)
-  rescue
-    e in UndefinedFunctionError ->
-      raise_undefined_behaviour e, struct, {^struct, :fetch, [^container, ^key], _}
-  end
-
-  def fetch(map, key) when is_map(map) do
-    case map do
-      %{^key => value} -> {:ok, value}
-      _ -> :error
-    end
-  end
-
-  def fetch(list, key) when is_list(list) and is_atom(key) do
-    case :lists.keyfind(key, 1, list) do
-      {_, value} -> {:ok, value}
-      false -> :error
-    end
-  end
-
-  def fetch(list, key) when is_list(list) do
-    raise ArgumentError,
-      "the Access calls for keywords expect the key to be an atom, got: " <> inspect(key)
-  end
-
-  def fetch(nil, _key) do
-    :error
-  end
-
-  @doc """
-  Gets the value for the given key in a container (a map, keyword
-  list, or struct that implements the `Access` behaviour).
-
-  Returns the value under `key` if there is such a key, or `default` if `key` is
-  not found.
-  """
-  @spec get(container, term, term) :: term
-  @spec get(nil_container, any, default) :: default when default: var
-  def get(container, key, default \\ nil)
-
-  def get(%{__struct__: struct} = container, key, default) do
-    try do
-      struct.fetch(container, key)
-    rescue
-      e in UndefinedFunctionError ->
-        raise_undefined_behaviour e, struct, {^struct, :fetch, [^container, ^key], _}
-    else
-      {:ok, value} -> value
-      :error -> default
-    end
-  end
-
-  def get(map, key, default) when is_map(map) do
-    case map do
-      %{^key => value} -> value
-      _ -> default
-    end
-  end
-
-  def get(list, key, default) when is_list(list) and is_atom(key) do
-    case :lists.keyfind(key, 1, list) do
-      {_, value} -> value
-      false -> default
-    end
-  end
-
-  def get(list, key, _default) when is_list(list) do
-    raise ArgumentError,
-      "the Access calls for keywords expect the key to be an atom, got: " <> inspect(key)
-  end
-
-  def get(nil, _key, default) do
-    default
-  end
-
-  @doc """
-  Gets and updates the given key in a `container` (a map, a keyword list,
-  a struct that implements the `Access` behaviour).
-
-  The `fun` argument receives the value of `key` (or `nil` if `key` is not
-  present in `container`) and must return a two-element tuple `{get_value, update_value}`:
-  the "get" value `get_value` (the retrieved value, which can be operated on before
-  being returned) and the new value to be stored under `key` (`update_value`).
-  `fun` may also return `:pop`, which means the current value
-  should be removed from the container and returned.
-
-  The returned value is a two-element tuple with the "get" value returned by
-  `fun` and a new container with the updated value under `key`.
-  """
-  @spec get_and_update(data, key, (value -> {get_value, value} | :pop)) ::
-        {get_value, data} when get_value: var, data: container
+  @spec get_and_update(t, term, (term -> {get, term})) :: {get, t} when get: var
   def get_and_update(container, key, fun)
+end
 
-  def get_and_update(%{__struct__: struct} = container, key, fun) do
-    struct.get_and_update(container, key, fun)
-  rescue
-    e in UndefinedFunctionError ->
-      raise_undefined_behaviour e, struct, {^struct, :get_and_update, [^container, ^key, ^fun], _}
+defimpl Access, for: List do
+  def get(dict, key) when is_atom(key) do
+    case :lists.keyfind(key, 1, dict) do
+      {^key, value} -> value
+      false -> nil
+    end
   end
 
-  def get_and_update(map, key, fun) when is_map(map) do
-    Map.get_and_update(map, key, fun)
+  def get(_dict, key) do
+    raise ArgumentError,
+      "the access protocol for lists expect the key to be an atom, got: #{inspect key}"
   end
 
-  def get_and_update(list, key, fun) when is_list(list) do
-    Keyword.get_and_update(list, key, fun)
+  def get_and_update(dict, key, fun) when is_atom(key) do
+    get_and_update(dict, [], key, fun)
+  end
+
+  defp get_and_update([{key, value}|t], acc, key, fun) do
+    {get, update} = fun.(value)
+    {get, :lists.reverse(acc, [{key, update}|t])}
+  end
+
+  defp get_and_update([h|t], acc, key, fun) do
+    get_and_update(t, [h|acc], key, fun)
+  end
+
+  defp get_and_update([], acc, key, fun) do
+    {get, update} = fun.(nil)
+    {get, [{key, update}|:lists.reverse(acc)]}
+  end
+end
+
+defimpl Access, for: Map do
+  def get(map, key) do
+    case :maps.find(key, map) do
+      {:ok, value} -> value
+      :error -> nil
+    end
+  end
+
+  def get_and_update(map, key, fun) do
+    value =
+      case :maps.find(key, map) do
+        {:ok, value} -> value
+        :error -> nil
+      end
+
+    {get, update} = fun.(value)
+    {get, :maps.put(key, update, map)}
+  end
+
+  def get!(%{} = map, key) do
+    case :maps.find(key, map) do
+      {:ok, value} -> value
+      :error -> raise KeyError, key: key, term: map
+    end
+  end
+
+  def get!(other, key) do
+    raise ArgumentError,
+      "could not get key #{inspect key}. Expected map/struct, got: #{inspect other}"
+  end
+
+  def get_and_update!(%{} = map, key, fun) do
+    case :maps.find(key, map) do
+      {:ok, value} ->
+        {get, update} = fun.(value)
+        {get, :maps.put(key, update, map)}
+      :error ->
+        raise KeyError, key: key, term: map
+    end
+  end
+
+  def get_and_update!(other, key, _fun) do
+    raise ArgumentError,
+      "could not put/update key #{inspect key}. Expected map/struct, got: #{inspect other}"
+  end
+end
+
+defimpl Access, for: Atom do
+  def get(nil, _) do
+    nil
+  end
+
+  def get(atom, _) do
+    undefined(atom)
   end
 
   def get_and_update(nil, key, _fun) do
@@ -372,332 +137,14 @@ defmodule Access do
       "could not put/update key #{inspect key} on a nil value"
   end
 
-  @doc """
-  Removes the entry with a given key from a container (a map, keyword
-  list, or struct that implements the `Access` behaviour).
-
-  Returns a tuple containing the value associated with the key and the
-  updated container. `nil` is returned for the value if the key isn't
-  in the container.
-
-  ## Examples
-
-  With a map:
-
-      iex> Access.pop(%{name: "Elixir", creator: "Valim"}, :name)
-      {"Elixir", %{creator: "Valim"}}
-
-  A keyword list:
-
-      iex> Access.pop([name: "Elixir", creator: "Valim"], :name)
-      {"Elixir", [creator: "Valim"]}
-
-  An unknown key:
-
-      iex> Access.pop(%{name: "Elixir", creator: "Valim"}, :year)
-      {nil, %{creator: "Valim", name: "Elixir"}}
-
-  """
-  @spec pop(data, key) :: {value, data} when data: container
-  def pop(%{__struct__: struct} = container, key) do
-    struct.pop(container, key)
-  rescue
-    e in UndefinedFunctionError ->
-      raise_undefined_behaviour e, struct, {^struct, :pop, [^container, ^key], _}
+  def get_and_update(atom, _key, _fun) do
+    undefined(atom)
   end
 
-  def pop(map, key) when is_map(map) do
-    Map.pop(map, key)
-  end
-
-  def pop(list, key) when is_list(list) do
-    Keyword.pop(list, key)
-  end
-
-  def pop(nil, key) do
-    raise ArgumentError,
-      "could not pop key #{inspect key} on a nil value"
-  end
-
-  ## Accessors
-
-  @doc """
-  Returns a function that accesses the given key in a map/struct.
-
-  The returned function is typically passed as an accessor to `Kernel.get_in/2`,
-  `Kernel.get_and_update_in/3`, and friends.
-
-  The returned function uses the default value if the key does not exist.
-  This can be used to specify defaults and safely traverse missing keys:
-
-      iex> get_in(%{}, [Access.key(:user, %{}), Access.key(:name)])
-      nil
-
-  Such is also useful when using update functions, allowing us to introduce
-  values as we traverse the data structure for updates:
-
-      iex> put_in(%{}, [Access.key(:user, %{}), Access.key(:name)], "Mary")
-      %{user: %{name: "Mary"}}
-
-  ## Examples
-
-      iex> map = %{user: %{name: "john"}}
-      iex> get_in(map, [Access.key(:unknown, %{}), Access.key(:name, "john")])
-      "john"
-      iex> get_and_update_in(map, [Access.key(:user), Access.key(:name)], fn
-      ...>   prev -> {prev, String.upcase(prev)}
-      ...> end)
-      {"john", %{user: %{name: "JOHN"}}}
-      iex> pop_in(map, [Access.key(:user), Access.key(:name)])
-      {"john", %{user: %{}}}
-
-  An error is raised if the accessed structure is not a map or a struct:
-
-      iex> get_in(nil, [Access.key(:foo)])
-      ** (BadMapError) expected a map, got: nil
-
-      iex> get_in([], [Access.key(:foo)])
-      ** (BadMapError) expected a map, got: []
-
-  """
-  @spec key(key, term) :: access_fun(data :: struct | map, get_value :: term)
-  def key(key, default \\ nil) do
-    fn
-      :get, data, next ->
-        next.(Map.get(data, key, default))
-      :get_and_update, data, next ->
-        value = Map.get(data, key, default)
-        case next.(value) do
-          {get, update} -> {get, Map.put(data, key, update)}
-          :pop -> {value, Map.delete(data, key)}
-        end
-    end
-  end
-
-  @doc """
-  Returns a function that accesses the given key in a map/struct.
-
-  The returned function is typically passed as an accessor to `Kernel.get_in/2`,
-  `Kernel.get_and_update_in/3`, and friends.
-
-  The returned function raises if the key does not exist.
-
-  ## Examples
-
-      iex> map = %{user: %{name: "john"}}
-      iex> get_in(map, [Access.key!(:user), Access.key!(:name)])
-      "john"
-      iex> get_and_update_in(map, [Access.key!(:user), Access.key!(:name)], fn
-      ...>   prev -> {prev, String.upcase(prev)}
-      ...> end)
-      {"john", %{user: %{name: "JOHN"}}}
-      iex> pop_in(map, [Access.key!(:user), Access.key!(:name)])
-      {"john", %{user: %{}}}
-      iex> get_in(map, [Access.key!(:user), Access.key!(:unknown)])
-      ** (KeyError) key :unknown not found in: %{name: \"john\"}
-
-  An error is raised if the accessed structure is not a map/struct:
-
-      iex> get_in([], [Access.key!(:foo)])
-      ** (RuntimeError) Access.key!/1 expected a map/struct, got: []
-
-  """
-  @spec key!(key) :: access_fun(data :: struct | map, get_value :: term)
-  def key!(key) do
-    fn
-      :get, %{} = data, next ->
-        next.(Map.fetch!(data, key))
-      :get_and_update, %{} = data, next ->
-        value = Map.fetch!(data, key)
-        case next.(value) do
-          {get, update} -> {get, Map.put(data, key, update)}
-          :pop -> {value, Map.delete(data, key)}
-        end
-      _op, data, _next ->
-        raise "Access.key!/1 expected a map/struct, got: #{inspect data}"
-    end
-  end
-
-  @doc ~S"""
-  Returns a function that accesses the element at the given index in a tuple.
-
-  The returned function is typically passed as an accessor to `Kernel.get_in/2`,
-  `Kernel.get_and_update_in/3`, and friends.
-
-  The returned function raises if `index` is out of bounds.
-
-  ## Examples
-
-      iex> map = %{user: {"john", 27}}
-      iex> get_in(map, [:user, Access.elem(0)])
-      "john"
-      iex> get_and_update_in(map, [:user, Access.elem(0)], fn
-      ...>   prev -> {prev, String.upcase(prev)}
-      ...> end)
-      {"john", %{user: {"JOHN", 27}}}
-      iex> pop_in(map, [:user, Access.elem(0)])
-      ** (RuntimeError) cannot pop data from a tuple
-
-  An error is raised if the accessed structure is not a tuple:
-
-      iex> get_in(%{}, [Access.elem(0)])
-      ** (RuntimeError) Access.elem/1 expected a tuple, got: %{}
-
-  """
-  @spec elem(non_neg_integer) :: access_fun(data :: tuple, get_value :: term)
-  def elem(index) when is_integer(index) do
-    pos = index + 1
-
-    fn
-      :get, data, next when is_tuple(data) ->
-        next.(:erlang.element(pos, data))
-      :get_and_update, data, next when is_tuple(data) ->
-        value = :erlang.element(pos, data)
-        case next.(value) do
-          {get, update} -> {get, :erlang.setelement(pos, data, update)}
-          :pop -> raise "cannot pop data from a tuple"
-        end
-      _op, data, _next ->
-        raise "Access.elem/1 expected a tuple, got: #{inspect data}"
-    end
-  end
-
-  @doc ~S"""
-  Returns a function that accesses all the elements in a list.
-
-  The returned function is typically passed as an accessor to `Kernel.get_in/2`,
-  `Kernel.get_and_update_in/3`, and friends.
-
-  ## Examples
-
-      iex> list = [%{name: "john"}, %{name: "mary"}]
-      iex> get_in(list, [Access.all(), :name])
-      ["john", "mary"]
-      iex> get_and_update_in(list, [Access.all(), :name], fn
-      ...>   prev -> {prev, String.upcase(prev)}
-      ...> end)
-      {["john", "mary"], [%{name: "JOHN"}, %{name: "MARY"}]}
-      iex> pop_in(list, [Access.all(), :name])
-      {["john", "mary"], [%{}, %{}]}
-
-  Here is an example that traverses the list dropping even
-  numbers and multiplying odd numbers by 2:
-
-      iex> require Integer
-      iex> get_and_update_in([1, 2, 3, 4, 5], [Access.all], fn
-      ...>   num -> if Integer.is_even(num), do: :pop, else: {num, num * 2}
-      ...> end)
-      {[1, 2, 3, 4, 5], [2, 6, 10]}
-
-  An error is raised if the accessed structure is not a list:
-
-      iex> get_in(%{}, [Access.all()])
-      ** (RuntimeError) Access.all/0 expected a list, got: %{}
-
-  """
-  @spec all() :: access_fun(data :: list, get_value :: list)
-  def all() do
-    &all/3
-  end
-
-  defp all(:get, data, next) when is_list(data) do
-    Enum.map(data, next)
-  end
-
-  defp all(:get_and_update, data, next) when is_list(data) do
-    all(data, next, _gets = [], _updates = [])
-  end
-
-  defp all(_op, data, _next) do
-    raise "Access.all/0 expected a list, got: #{inspect data}"
-  end
-
-  defp all([head | rest], next, gets, updates) do
-    case next.(head) do
-      {get, update} -> all(rest, next, [get | gets], [update | updates])
-      :pop -> all(rest, next, [head | gets], updates)
-    end
-  end
-
-  defp all([], _next, gets, updates) do
-    {:lists.reverse(gets), :lists.reverse(updates)}
-  end
-
-  @doc ~S"""
-  Returns a function that accesses the element at `index` (zero based) of a list.
-
-  The returned function is typically passed as an accessor to `Kernel.get_in/2`,
-  `Kernel.get_and_update_in/3`, and friends.
-
-  ## Examples
-
-      iex> list = [%{name: "john"}, %{name: "mary"}]
-      iex> get_in(list, [Access.at(1), :name])
-      "mary"
-      iex> get_and_update_in(list, [Access.at(0), :name], fn
-      ...>   prev -> {prev, String.upcase(prev)}
-      ...> end)
-      {"john", [%{name: "JOHN"}, %{name: "mary"}]}
-
-  `at/1` can also be used to pop elements out of a list or
-  a key inside of a list:
-
-      iex> list = [%{name: "john"}, %{name: "mary"}]
-      iex> pop_in(list, [Access.at(0)])
-      {%{name: "john"}, [%{name: "mary"}]}
-      iex> pop_in(list, [Access.at(0), :name])
-      {"john", [%{}, %{name: "mary"}]}
-
-  When the index is out of bounds, `nil` is returned and the update function is never called:
-
-      iex> list = [%{name: "john"}, %{name: "mary"}]
-      iex> get_in(list, [Access.at(10), :name])
-      nil
-      iex> get_and_update_in(list, [Access.at(10), :name], fn
-      ...>   prev -> {prev, String.upcase(prev)}
-      ...> end)
-      {nil, [%{name: "john"}, %{name: "mary"}]}
-
-  An error is raised for negative indexes:
-
-      iex> get_in([], [Access.at(-1)])
-      ** (FunctionClauseError) no function clause matching in Access.at/1
-
-  An error is raised if the accessed structure is not a list:
-
-      iex> get_in(%{}, [Access.at(1)])
-      ** (RuntimeError) Access.at/1 expected a list, got: %{}
-
-  """
-  @spec at(non_neg_integer) :: access_fun(data :: list, get_value :: term)
-  def at(index) when is_integer(index) and index >= 0 do
-    fn(op, data, next) -> at(op, data, index, next) end
-  end
-
-  defp at(:get, data, index, next) when is_list(data) do
-    data |> Enum.at(index) |> next.()
-  end
-
-  defp at(:get_and_update, data, index, next) when is_list(data) do
-    get_and_update_at(data, index, next, [])
-  end
-
-  defp at(_op, data, _index, _next) do
-    raise "Access.at/1 expected a list, got: #{inspect data}"
-  end
-
-  defp get_and_update_at([head | rest], 0, next, updates) do
-    case next.(head) do
-      {get, update} -> {get, :lists.reverse([update | updates], rest)}
-      :pop -> {head, :lists.reverse(updates, rest)}
-    end
-  end
-
-  defp get_and_update_at([head | rest], index, next, updates) do
-    get_and_update_at(rest, index - 1, next, [head | updates])
-  end
-
-  defp get_and_update_at([], _index, _next, updates) do
-    {nil, :lists.reverse(updates)}
+  defp undefined(atom) do
+    raise Protocol.UndefinedError,
+      protocol: @protocol,
+      value: atom,
+      description: "only the nil atom is supported"
   end
 end

lib/elixir/lib/agent.ex

@@ -6,20 +6,18 @@ defmodule Agent do
   must be accessed from different processes or by the same process
   at different points in time.
 
-  The `Agent` module provides a basic server implementation that
+  The Agent module provides a basic server implementation that
   allows state to be retrieved and updated via a simple API.
 
   ## Examples
 
   For example, in the Mix tool that ships with Elixir, we need
   to keep a set of all tasks executed by a given project. Since
-  this set is shared, we can implement it with an agent:
+  this set is shared, we can implement it with an Agent:
 
       defmodule Mix.TasksServer do
-        use Agent
-
         def start_link do
-          Agent.start_link(fn -> MapSet.new end, name: __MODULE__)
+          Agent.start_link(fn -> HashSet.new end, name: __MODULE__)
         end
 
         @doc "Checks if the task has already executed"
@@ -33,22 +31,16 @@ defmodule Agent do
         @doc "Marks a task as executed"
         def put_task(task, project) do
           item = {task, project}
-          Agent.update(__MODULE__, &MapSet.put(&1, item))
-        end
-
-        @doc "Resets the executed tasks and returns the previous list of tasks"
-        def take_all() do
-          Agent.get_and_update(__MODULE__, fn set ->
-            {Enum.into(set, []), MapSet.new}
-          end)
+          Agent.update(__MODULE__, &Set.put(&1, item))
         end
       end
 
-  Agents provide a segregation between the client and server APIs (similar
-  to GenServers). In particular, the anonymous functions given to the `Agent`
-  are executed inside the agent (the server). This distinction is important
-  because you may want to avoid expensive operations inside the agent,
-  as they will effectively block the agent until the request is fulfilled.
+  Note that agents still provide a segregation between the
+  client and server APIs, as seen in GenServers. In particular,
+  all code inside the function passed to the agent is executed
+  by the agent. This distinction is important because you may
+  want to avoid expensive operations inside the agent, as it will
+  effectively block the agent until the request is fulfilled.
 
   Consider these two examples:
 
@@ -62,42 +54,22 @@ defmodule Agent do
         Agent.get(agent, &(&1)) |> do_something_expensive()
       end
 
-  The first function blocks the agent. The second function copies all the state
-  to the client and then executes the operation in the client. One aspect to
-  consider is whether the data is large enough to require processing in the server,
-  at least initially, or small enough to be sent to the client cheaply. Another
-  factor is whether the data needs to be processed atomically: getting the
-  state and calling `do_something_expensive(state)` outside of the agent means
-  that the agent's state can be updated in the meantime. This is specially
-  important in case of updates as computing the new state in the client rather
-  than in the server can lead to race conditions if multiple clients are trying
-  to update the same state to different values.
+  The first one blocks the agent while the second one copies
+  all the state to the client and executes the operation in the client.
+  The trade-off here is exactly if the data is small enough to be
+  sent to the client cheaply or large enough to require processing on
+  the server (or at least some initial processing).
 
-  Finally note `use Agent` defines a `child_spec/1` function, allowing the
-  defined module to be put under a supervision tree. The generated
-  `child_spec/1` can be customized with the following options:
+  ## Name Registration
 
-    * `:id` - the child specification id, defauts to the current module
-    * `:start` - how to start the child process (defaults to calling `__MODULE__.start_link/1`)
-    * `:restart` - when the child should be restarted, defaults to `:permanent`
-    * `:shutdown` - how to shut down the child
-
-  For example:
-
-      use Agent, restart: :transient, shutdown: 10_000
-
-  See the `Supervisor` docs for more information.
-
-  ## Name registration
-
-  An agent is bound to the same name registration rules as GenServers.
-  Read more about it in the `GenServer` documentation.
+  An Agent is bound to the same name registration rules as GenServers.
+  Read more about it in the `GenServer` docs.
 
   ## A word on distributed agents
 
   It is important to consider the limitations of distributed agents. Agents
-  provide two APIs, one that works with anonymous functions and another
-  that expects an explicit module, function, and arguments.
+  provides two APIs, one that works with anonymous functions and another
+  that expects explicit module, function and arguments.
 
   In a distributed setup with multiple nodes, the API that accepts anonymous
   functions only works if the caller (client) and the agent have the same
@@ -110,21 +82,20 @@ defmodule Agent do
   In this setup, part of your environment will have one version of a given
   module and the other part another version (the newer one) of the same module.
 
-  The best solution is to simply use the explicit module, function, and arguments
+  The best solution is to simply use the explicit module, function and arguments
   APIs when working with distributed agents.
 
   ## Hot code swapping
 
   An agent can have its code hot swapped live by simply passing a module,
-  function, and arguments tuple to the update instruction. For example, imagine
+  function and args tuple to the update instruction. For example, imagine
   you have an agent named `:sample` and you want to convert its inner state
-  from a keyword list to a map. It can be done with the following
+  from some dict structure to a map. It can be done with the following
   instruction:
 
       {:update, :sample, {:advanced, {Enum, :into, [%{}]}}}
 
-  The agent's state will be added to the given list of arguments (`[%{}]`) as
-  the first argument.
+  The agent's state will be added to the given list as the first argument.
   """
 
   @typedoc "Return values of `start*` functions"
@@ -139,41 +110,13 @@ defmodule Agent do
   @typedoc "The agent state"
   @type state :: term
 
-  @doc false
-  def child_spec(arg) do
-    %{
-      id: Agent,
-      start: {Agent, :start_link, [arg]}
-    }
-  end
-
-  @doc false
-  defmacro __using__(opts) do
-    quote location: :keep, bind_quoted: [opts: opts] do
-      spec = [
-        id: opts[:id] || __MODULE__,
-        start: Macro.escape(opts[:start]) || quote(do: {__MODULE__, :start_link, [arg]}),
-        restart: opts[:restart] || :permanent,
-        shutdown: opts[:shutdown] || 5000,
-        type: :worker
-      ]
-
-      @doc false
-      def child_spec(arg) do
-        %{unquote_splicing(spec)}
-      end
-
-      defoverridable child_spec: 1
-    end
-  end
-
   @doc """
   Starts an agent linked to the current process with the given function.
 
   This is often used to start the agent as part of a supervision tree.
 
-  Once the agent is spawned, the given function `fun` is invoked and its return
-  value is used as the agent state. Note that `start_link/2` does not return
+  Once the agent is spawned, the given function is invoked and its return
+  value is used as the agent state. Note that `start_link` does not return
   until the given function has returned.
 
   ## Options
@@ -194,22 +137,12 @@ defmodule Agent do
   ## Return values
 
   If the server is successfully created and initialized, the function returns
-  `{:ok, pid}`, where `pid` is the PID of the server. If an agent with the
-  specified name already exists, the function returns
-  `{:error, {:already_started, pid}}` with the PID of that process.
-
-  If the given function callback fails, the function returns `{:error, reason}`.
-
-  ## Examples
-
-      iex> {:ok, pid} = Agent.start_link(fn -> 42 end)
-      iex> Agent.get(pid, fn state -> state end)
-      42
-
-      iex> {:error, {exception, _stacktrace}} = Agent.start(fn -> raise "oops" end)
-      iex> exception
-      %RuntimeError{message: "oops"}
+  `{:ok, pid}`, where `pid` is the pid of the server. If there already exists
+  an agent with the specified name, the function returns
+  `{:error, {:already_started, pid}}` with the pid of that process.
 
+  If the given function callback fails with `reason`, the function returns
+  `{:error, reason}`.
   """
   @spec start_link((() -> term), GenServer.options) :: on_start
   def start_link(fun, options \\ []) when is_function(fun, 0) do
@@ -217,11 +150,11 @@ defmodule Agent do
   end
 
   @doc """
-  Starts an agent linked to the current process.
+  Starts an agent linked to the current process with the given module
+  function and arguments.
 
-  Same as `start_link/2` but a module, function, and arguments are expected
-  instead of an anonymous function; `fun` in `module` will be called with the
-  given arguments `args` to initialize the state.
+  Same as `start_link/2` but a module, function and args are expected
+  instead of an anonymous function.
   """
   @spec start_link(module, atom, [any], GenServer.options) :: on_start
   def start_link(module, fun, args, options \\ []) do
@@ -232,13 +165,6 @@ defmodule Agent do
   Starts an agent process without links (outside of a supervision tree).
 
   See `start_link/2` for more information.
-
-  ## Examples
-
-      iex> {:ok, pid} = Agent.start(fn -> 42 end)
-      iex> Agent.get(pid, fn(state) -> state end)
-      42
-
   """
   @spec start((() -> term), GenServer.options) :: on_start
   def start(fun, options \\ []) when is_function(fun, 0) do
@@ -246,9 +172,10 @@ defmodule Agent do
   end
 
   @doc """
-  Starts an agent without links with the given module, function, and arguments.
+  Starts an agent with the given module function and arguments.
 
-  See `start_link/4` for more information.
+  Similar to `start/2` but a module, function and args are expected
+  instead of an anonymous function.
   """
   @spec start(module, atom, [any], GenServer.options) :: on_start
   def start(module, fun, args, options \\ []) do
@@ -256,24 +183,13 @@ defmodule Agent do
   end
 
   @doc """
-  Gets an agent value via the given anonymous function.
+  Gets an agent value via the given function.
 
   The function `fun` is sent to the `agent` which invokes the function
   passing the agent state. The result of the function invocation is
-  returned from this function.
-
-  `timeout` is an integer greater than zero which specifies how many
-  milliseconds are allowed before the agent executes the function and returns
-  the result value, or the atom `:infinity` to wait indefinitely. If no result
-  is received within the specified time, the function call fails and the caller
-  exits.
-
-  ## Examples
-
-      iex> {:ok, pid} = Agent.start_link(fn -> 42 end)
-      iex> Agent.get(pid, fn state -> state end)
-      42
+  returned.
 
+  A timeout can also be specified (it has a default value of 5000).
   """
   @spec get(agent, (state -> a), timeout) :: a when a: var
   def get(agent, fun, timeout \\ 5000) when is_function(fun, 1) do
@@ -283,9 +199,9 @@ defmodule Agent do
   @doc """
   Gets an agent value via the given function.
 
-  Same as `get/3` but a module, function, and arguments are expected
+  Same as `get/3` but a module, function and args are expected
   instead of an anonymous function. The state is added as first
-  argument to the given list of arguments.
+  argument to the given list of args.
   """
   @spec get(agent, module, atom, [term], timeout) :: any
   def get(agent, module, fun, args, timeout \\ 5000) do
@@ -293,28 +209,14 @@ defmodule Agent do
   end
 
   @doc """
-  Gets and updates the agent state in one operation via the given anonymous
-  function.
+  Gets and updates the agent state in one operation.
 
   The function `fun` is sent to the `agent` which invokes the function
   passing the agent state. The function must return a tuple with two
-  elements, the first being the value to return (that is, the "get" value)
-  and the second one being the new state of the agent.
-
-  `timeout` is an integer greater than zero which specifies how many
-  milliseconds are allowed before the agent executes the function and returns
-  the result value, or the atom `:infinity` to wait indefinitely. If no result
-  is received within the specified time, the function call fails and the caller
-  exits.
-
-  ## Examples
-
-      iex> {:ok, pid} = Agent.start_link(fn -> 42 end)
-      iex> Agent.get_and_update(pid, fn state -> {state, state + 1} end)
-      42
-      iex> Agent.get(pid, fn state -> state end)
-      43
+  elements, the first being the value to return (i.e. the `get` value)
+  and the second one is the new state.
 
+  A timeout can also be specified (it has a default value of 5000).
   """
   @spec get_and_update(agent, (state -> {a, state}), timeout) :: a when a: var
   def get_and_update(agent, fun, timeout \\ 5000) when is_function(fun, 1) do
@@ -322,11 +224,11 @@ defmodule Agent do
   end
 
   @doc """
-  Gets and updates the agent state in one operation via the given function.
+  Gets and updates the agent state in one operation.
 
-  Same as `get_and_update/3` but a module, function, and arguments are expected
+  Same as `get_and_update/3` but a module, function and args are expected
   instead of an anonymous function. The state is added as first
-  argument to the given list of arguments.
+  argument to the given list of args.
   """
   @spec get_and_update(agent, module, atom, [term], timeout) :: any
   def get_and_update(agent, module, fun, args, timeout \\ 5000) do
@@ -334,28 +236,13 @@ defmodule Agent do
   end
 
   @doc """
-  Updates the agent state via the given anonymous function.
+  Updates the agent state.
 
   The function `fun` is sent to the `agent` which invokes the function
-  passing the agent state. The return value of `fun` becomes the new
-  state of the agent.
+  passing the agent state. The function must return the new state.
 
+  A timeout can also be specified (it has a default value of 5000).
   This function always returns `:ok`.
-
-  `timeout` is an integer greater than zero which specifies how many
-  milliseconds are allowed before the agent executes the function and returns
-  the result value, or the atom `:infinity` to wait indefinitely. If no result
-  is received within the specified time, the function call fails and the caller
-  exits.
-
-  ## Examples
-
-      iex> {:ok, pid} = Agent.start_link(fn -> 42 end)
-      iex> Agent.update(pid, fn state -> state + 1 end)
-      :ok
-      iex> Agent.get(pid, fn state -> state end)
-      43
-
   """
   @spec update(agent, (state -> state), timeout) :: :ok
   def update(agent, fun, timeout \\ 5000) when is_function(fun, 1) do
@@ -363,11 +250,11 @@ defmodule Agent do
   end
 
   @doc """
-  Updates the agent state via the given function.
+  Updates the agent state.
 
-  Same as `update/3` but a module, function, and arguments are expected
+  Same as `update/3` but a module, function and args are expected
   instead of an anonymous function. The state is added as first
-  argument to the given list of arguments.
+  argument to the given list of args.
   """
   @spec update(agent, module, atom, [term], timeout) :: :ok
   def update(agent, module, fun, args, timeout \\ 5000) do
@@ -375,14 +262,13 @@ defmodule Agent do
   end
 
   @doc """
-  Performs a cast (*fire and forget*) operation on the agent state.
+  Performs a cast (fire and forget) operation on the agent state.
 
   The function `fun` is sent to the `agent` which invokes the function
-  passing the agent state. The return value of `fun` becomes the new
-  state of the agent.
+  passing the agent state. The function must return the new state.
 
-  Note that `cast` returns `:ok` immediately, regardless of whether `agent` (or
-  the node it should live on) exists.
+  Note that `cast` returns `:ok` immediately, regardless of whether the
+  destination node or agent exists.
   """
   @spec cast(agent, (state -> state)) :: :ok
   def cast(agent, fun) when is_function(fun, 1) do
@@ -390,11 +276,11 @@ defmodule Agent do
   end
 
   @doc """
-  Performs a cast (*fire and forget*) operation on the agent state.
+  Performs a cast (fire and forget) operation on the agent state.
 
-  Same as `cast/2` but a module, function, and arguments are expected
+  Same as `cast/2` but a module, function and args are expected
   instead of an anonymous function. The state is added as first
-  argument to the given list of arguments.
+  argument to the given list of args.
   """
   @spec cast(agent, module, atom, [term]) :: :ok
   def cast(agent, module, fun, args) do
@@ -402,25 +288,12 @@ defmodule Agent do
   end
 
   @doc """
-  Synchronously stops the agent with the given `reason`.
-
-  It returns `:ok` if the agent terminates with the given
-  reason. If the agent terminates with another reason, the call will
-  exit.
-
-  This function keeps OTP semantics regarding error reporting.
-  If the reason is any other than `:normal`, `:shutdown` or
-  `{:shutdown, _}`, an error report will be logged.
-
-  ## Examples
-
-      iex> {:ok, pid} = Agent.start_link(fn -> 42 end)
-      iex> Agent.stop(pid)
-      :ok
+  Stops the agent.
 
+  Returns `:ok` if the agent is stopped within the given `timeout`.
   """
-  @spec stop(agent, reason :: term, timeout) :: :ok
-  def stop(agent, reason \\ :normal, timeout \\ :infinity) do
-    GenServer.stop(agent, reason, timeout)
+  @spec stop(agent, timeout) :: :ok
+  def stop(agent, timeout \\ 5000) do
+    GenServer.call(agent, :stop, timeout)
   end
 end

lib/elixir/lib/agent/server.ex

@@ -4,7 +4,6 @@ defmodule Agent.Server do
   use GenServer
 
   def init(fun) do
-    _ = initial_call(fun)
     {:ok, run(fun, [])}
   end
 
@@ -13,16 +12,18 @@ defmodule Agent.Server do
   end
 
   def handle_call({:get_and_update, fun}, _from, state) do
-    case run(fun, [state]) do
-      {reply, state} -> {:reply, reply, state}
-      other          -> {:stop, {:bad_return_value, other}, state}
-    end
+    {reply, state} = run(fun, [state])
+    {:reply, reply, state}
   end
 
   def handle_call({:update, fun}, _from, state) do
     {:reply, :ok, run(fun, [state])}
   end
 
+  def handle_call(:stop, _from, state) do
+    {:stop, :normal, :ok, state}
+  end
+
   def handle_call(msg, from, state) do
     super(msg, from, state)
   end
@@ -39,21 +40,17 @@ defmodule Agent.Server do
     {:ok, run(fun, [state])}
   end
 
-  defp initial_call(mfa) do
-    _ = Process.put(:"$initial_call", get_initial_call(mfa))
+  def terminate(_reason, _state) do
+    # There is a race condition if the agent is
+    # restarted too fast and it is registered.
+    try do
+      self |> :erlang.process_info(:registered_name) |> elem(1) |> Process.unregister
+    rescue
+      _ -> :ok
+    end
     :ok
   end
 
-  defp get_initial_call(fun) when is_function(fun, 0) do
-    {:module, module} = :erlang.fun_info(fun, :module)
-    {:name, name} = :erlang.fun_info(fun, :name)
-    {module, name, 0}
-  end
-
-  defp get_initial_call({mod, fun, args}) do
-    {mod, fun, length(args)}
-  end
-
   defp run({m, f, a}, extra), do: apply(m, f, extra ++ a)
   defp run(fun, extra), do: apply(fun, extra)
 end

lib/elixir/lib/application.ex

@@ -4,29 +4,29 @@ defmodule Application do
 
   In Elixir (actually, in Erlang/OTP), an application is a component
   implementing some specific functionality, that can be started and stopped
-  as a unit, and which can be re-used in other systems.
+  as a unit, and which can be re-used in other systems as well.
 
   Applications are defined with an application file named `APP.app` where
-  `APP` is the application name, usually in `underscore_case`. The application
-  file must reside in the same `ebin` directory as the compiled modules of the
-  application.
+  `APP` is the APP name, usually in `underscore_case` convention. The
+  application file must reside in the same `ebin` directory as the
+  application's modules bytecode.
 
   In Elixir, Mix is responsible for compiling your source code and
   generating your application `.app` file. Furthermore, Mix is also
   responsible for configuring, starting and stopping your application
   and its dependencies. For this reason, this documentation will focus
-  on the remaining aspects of your application: the application environment
+  on the remaining aspects of your application: the application environment,
   and the application callback module.
 
-  You can learn more about Mix generation of `.app` files by typing
+  You can learn more about Mix compilation of `.app` files by typing
   `mix help compile.app`.
 
   ## Application environment
 
   Once an application is started, OTP provides an application environment
-  that can be used to configure the application.
+  that can be used to configure applications.
 
-  Assuming you are inside a Mix project, you can edit the `application/0`
+  Assuming you are inside a Mix project, you can edit your application
   function in the `mix.exs` file to the following:
 
       def application do
@@ -38,15 +38,18 @@ defmodule Application do
   can access the default value:
 
       Application.get_env(:APP_NAME, :hello)
-      #=> :world
+      #=> {:ok, :hello}
 
   It is also possible to put and delete values from the application value,
   including new values that are not defined in the environment file (although
-  this should be avoided).
+  those should be avoided).
+
+  In the future, we plan to support configuration files which allows
+  developers to configure the environment of their dependencies.
 
   Keep in mind that each application is responsible for its environment.
-  Do not use the functions in this module for directly accessing or modifying
-  the environment of other applications (as it may lead to inconsistent
+  Do not use the functions in this module for directly access or modify
+  the environment of other application (as it may lead to inconsistent
   data in the application environment).
 
   ## Application module callback
@@ -61,8 +64,8 @@ defmodule Application do
       end
 
   Our application now requires the `MyApp` module to provide an application
-  callback. This can be done by invoking `use Application` in that module and
-  defining a `start/2` callback, for example:
+  callback. This can be done by invoking `use Application` in that module
+  and defining a `start/2` callback, for example:
 
       defmodule MyApp do
         use Application
@@ -72,174 +75,46 @@ defmodule Application do
         end
       end
 
-  `start/2` typically returns `{:ok, pid}` or `{:ok, pid, state}` where
-  `pid` identifies the supervision tree and `state` is the application state.
-  `args` is the second element of the tuple given to the `:mod` option.
+  `start/2` most commonly returns `{:ok, pid}` or `{:ok, pid, state}` where
+  `pid` identifies the supervision tree and the state is the application state.
+  `args` is second element of the tuple given to the `:mod` option.
 
-  The `type` argument passed to `start/2` is usually `:normal` unless in a
-  distributed setup where application takeovers and failovers are configured.
-  This particular aspect of applications is explained in more detail in the
-  OTP documentation:
+  The `type` passed into `start/2` is usually `:normal` unless in a distributed
+  setup where applications takeover and failovers are configured. This particular
+  aspect of applications can be read with more detail in the OTP documentation:
 
-    * [`:application` module](http://www.erlang.org/doc/man/application.html)
-    * [Applications – OTP Design Principles](http://www.erlang.org/doc/design_principles/applications.html)
+    * http://www.erlang.org/doc/man/application.html
+    * http://www.erlang.org/doc/design_principles/applications.html
 
   A developer may also implement the `stop/1` callback (automatically defined
   by `use Application`) which does any application cleanup. It receives the
-  application state and can return any value. Note that shutting down the
-  supervisor is automatically handled by the VM.
-
-  An application without a supervision tree doesn't define an application
-  module callback in the application definition in `mix.exs` file. Even though
-  there is no module with application callbacks such as `start/2` and
-  `stop/1`, the application can be started and stopped the same way as an
-  application with a supervision tree.
+  application state and can return any value. Notice that shutting down the
+  supervisor is automatically handled by the VM;
   """
 
-  @doc """
-  Called when an application is started.
-
-  This function is called when an application is started using
-  `Application.start/2` (and functions on top of that, such as
-  `Application.ensure_started/2`). This function should start the top-level
-  process of the application (which should be the top supervisor of the
-  application's supervision tree if the application follows the OTP design
-  principles around supervision).
-
-  `start_type` defines how the application is started:
-
-    * `:normal` - used if the startup is a normal startup or if the application
-      is distributed and is started on the current node because of a failover
-      from another node and the application specification key `:start_phases`
-      is `:undefined`.
-    * `{:takeover, node}` - used if the application is distributed and is
-      started on the current node because of a failover on the node `node`.
-    * `{:failover, node}` - used if the application is distributed and is
-      started on the current node because of a failover on node `node`, and the
-      application specification key `:start_phases` is not `:undefined`.
-
-  `start_args` are the arguments passed to the application in the `:mod`
-  specification key (e.g., `mod: {MyApp, [:my_args]}`).
-
-  This function should either return `{:ok, pid}` or `{:ok, pid, state}` if
-  startup is successful. `pid` should be the PID of the top supervisor. `state`
-  can be an arbitrary term, and if omitted will default to `[]`; if the
-  application is later stopped, `state` is passed to the `stop/1` callback (see
-  the documentation for the `c:stop/1` callback for more information).
-
-  `use Application` provides no default implementation for the `start/2`
-  callback.
-  """
-  @callback start(start_type, start_args :: term) ::
-    {:ok, pid} |
-    {:ok, pid, state} |
-    {:error, reason :: term}
-
-  @doc """
-  Called when an application is stopped.
-
-  This function is called when an application has stopped, i.e., when its
-  supervision tree has been stopped. It should do the opposite of what the
-  `start/2` callback did, and should perform any necessary cleanup. The return
-  value of this callback is ignored.
-
-  `state` is the return value of the `start/2` callback or the return value of
-  the `prep_stop/1` function if the application module defines such a function.
-
-  `use Application` defines a default implementation of this function which does
-  nothing and just returns `:ok`.
-  """
-  @callback stop(state) :: term
-
-  @doc """
-  Start an application in synchronous phases.
-
-  This function is called after `start/2` finishes but before
-  `Application.start/2` returns. It will be called once for every start phase
-  defined in the application's (and any included applications') specification,
-  in the order they are listed in.
-  """
-  @callback start_phase(phase :: term, start_type, phase_args :: term) ::
-    :ok |
-    {:error, reason :: term}
-
-  @optional_callbacks start_phase: 3
-
   @doc false
   defmacro __using__(_) do
     quote location: :keep do
-      @behaviour Application
+      @behaviour :application
 
       @doc false
       def stop(_state) do
         :ok
       end
 
-      defoverridable Application
+      defoverridable [stop: 1]
     end
   end
 
   @type app :: atom
   @type key :: atom
   @type value :: term
-  @type state :: term
   @type start_type :: :permanent | :transient | :temporary
 
-  @application_keys [:description, :id, :vsn, :modules, :maxP, :maxT, :registered,
-                     :included_applications, :applications, :mod, :start_phases]
-
-  @doc """
-  Returns the spec for `app`.
-
-  The following keys are returned:
-
-    * #{Enum.map_join @application_keys, "\n  * ", &inspect/1}
-
-  Note the environment is not returned as it can be accessed via
-  `fetch_env/2`. Returns `nil` if the application is not loaded.
-  """
-  @spec spec(app) :: [{key, value}] | nil
-  def spec(app) do
-    case :application.get_all_key(app) do
-      {:ok, info} -> :lists.keydelete(:env, 1, info)
-      :undefined  -> nil
-    end
-  end
-
-  @doc """
-  Returns the value for `key` in `app`'s specification.
-
-  See `spec/1` for the supported keys. If the given
-  specification parameter does not exist, this function
-  will raise. Returns `nil` if the application is not loaded.
-  """
-  @spec spec(app, key) :: value | nil
-  def spec(app, key) when key in @application_keys do
-    case :application.get_key(app, key) do
-      {:ok, value} -> value
-      :undefined -> nil
-    end
-  end
-
-  @doc """
-  Gets the application for the given module.
-
-  The application is located by analyzing the spec
-  of all loaded applications. Returns `nil` if
-  the module is not listed in any application spec.
-  """
-  @spec get_application(atom) :: atom | nil
-  def get_application(module) when is_atom(module) do
-    case :application.get_application(module) do
-      {:ok, app} -> app
-      :undefined -> nil
-    end
-  end
-
   @doc """
   Returns all key-value pairs for `app`.
   """
-  @spec get_all_env(app) :: [{key, value}]
+  @spec get_all_env(app) :: [{key,value}]
   def get_all_env(app) do
     :application.get_all_env(app)
   end
@@ -247,18 +122,22 @@ defmodule Application do
   @doc """
   Returns the value for `key` in `app`'s environment.
 
-  If the configuration parameter does not exist, the function returns the
-  `default` value.
+  If the specified application is not loaded, or the configuration parameter
+  does not exist, the function returns the `default` value.
   """
   @spec get_env(app, key, value) :: value
   def get_env(app, key, default \\ nil) do
-    :application.get_env(app, key, default)
+    case :application.get_env(app, key) do
+      {:ok, value} -> value
+      :undefined -> default
+    end
   end
 
   @doc """
   Returns the value for `key` in `app`'s environment in a tuple.
 
-  If the configuration parameter does not exist, the function returns `:error`.
+  If the specified application is not loaded, or the configuration parameter
+  does not exist, the function returns `:error`.
   """
   @spec fetch_env(app, key) :: {:ok, value} | :error
   def fetch_env(app, key) do
@@ -268,35 +147,19 @@ defmodule Application do
     end
   end
 
-  @doc """
-  Returns the value for `key` in `app`'s environment.
-
-  If the configuration parameter does not exist, raises `ArgumentError`.
-  """
-  @spec fetch_env!(app, key) :: value | no_return
-  def fetch_env!(app, key) do
-    case fetch_env(app, key) do
-      {:ok, value} -> value
-      :error ->
-        raise ArgumentError,
-          "application #{inspect app} is not loaded, " <>
-          "or the configuration parameter #{inspect key} is not set"
-    end
-  end
-
   @doc """
   Puts the `value` in `key` for the given `app`.
 
   ## Options
 
-    * `:timeout` - the timeout for the change (defaults to `5_000` milliseconds)
+    * `:timeout`    - the timeout for the change (defaults to 5000ms)
     * `:persistent` - persists the given value on application load and reloads
 
   If `put_env/4` is called before the application is loaded, the application
   environment values specified in the `.app` file will override the ones
   previously set.
 
-  The persistent option can be set to `true` when there is a need to guarantee
+  The persistent option can be set to true when there is a need to guarantee
   parameters set with this function will not be overridden by the ones defined
   in the application resource file on load. This means persistent values will
   stick after the application is loaded and also on application reload.
@@ -354,7 +217,7 @@ defmodule Application do
   started before this application is. If not, `{:error, {:not_started, app}}` is
   returned, where `app` is the name of the missing application.
 
-  In case you want to automatically load **and start** all of `app`'s dependencies,
+  In case you want to automatically  load **and start** all of `app`'s dependencies,
   see `ensure_all_started/2`.
 
   The `type` argument specifies the type of the application:
@@ -439,7 +302,7 @@ defmodule Application do
       #=> "bar-123"
 
   For more information on code paths, check the `Code` module in
-  Elixir and also Erlang's [`:code` module](http://www.erlang.org/doc/man/code.html).
+  Elixir and also Erlang's `:code` module.
   """
   @spec app_dir(app) :: String.t
   def app_dir(app) when is_atom(app) do
@@ -452,29 +315,10 @@ defmodule Application do
   @doc """
   Returns the given path inside `app_dir/1`.
   """
-  @spec app_dir(app, String.t | [String.t]) :: String.t
+  @spec app_dir(app, String.t) :: String.t
   def app_dir(app, path) when is_binary(path) do
     Path.join(app_dir(app), path)
   end
-  def app_dir(app, path) when is_list(path) do
-    Path.join([app_dir(app) | path])
-  end
-
-  @doc """
-  Returns a list with information about the applications which are currently running.
-  """
-  @spec started_applications(timeout) :: [tuple]
-  def started_applications(timeout \\ 5000) do
-    :application.which_applications(timeout)
-  end
-
-  @doc """
-  Returns a list with information about the applications which have been loaded.
-  """
-  @spec loaded_applications :: [tuple]
-  def loaded_applications do
-    :application.loaded_applications
-  end
 
   @doc """
   Formats the error reason returned by `start/2`,
@@ -484,9 +328,9 @@ defmodule Application do
   @spec format_error(any) :: String.t
   def format_error(reason) do
     try do
-      do_format_error(reason)
+      impl_format_error(reason)
     catch
-      # A user could create an error that looks like a built-in one
+      # A user could create an error that looks like a builtin one
       # causing an error.
       :error, _ ->
         inspect(reason)
@@ -494,68 +338,68 @@ defmodule Application do
   end
 
   # exit(:normal) call is special cased, undo the special case.
-  defp do_format_error({{:EXIT, :normal}, {mod, :start, args}}) do
+  defp impl_format_error({{:EXIT, :normal}, {mod, :start, args}}) do
     Exception.format_exit({:normal, {mod, :start, args}})
   end
 
   # {:error, reason} return value
-  defp do_format_error({reason, {mod, :start, args}}) do
+  defp impl_format_error({reason, {mod, :start, args}}) do
     Exception.format_mfa(mod, :start, args) <> " returned an error: " <>
       Exception.format_exit(reason)
   end
 
   # error or exit(reason) call, use exit reason as reason.
-  defp do_format_error({:bad_return, {{mod, :start, args}, {:EXIT, reason}}}) do
+  defp impl_format_error({:bad_return, {{mod, :start, args}, {:EXIT, reason}}}) do
     Exception.format_exit({reason, {mod, :start, args}})
   end
 
   # bad return value
-  defp do_format_error({:bad_return, {{mod, :start, args}, return}}) do
+  defp impl_format_error({:bad_return, {{mod, :start, args}, return}}) do
     Exception.format_mfa(mod, :start, args) <>
       " returned a bad value: " <> inspect(return)
   end
 
-  defp do_format_error({:already_started, app}) when is_atom(app) do
+  defp impl_format_error({:already_started, app}) when is_atom(app) do
     "already started application #{app}"
   end
 
-  defp do_format_error({:not_started, app}) when is_atom(app) do
+  defp impl_format_error({:not_started, app}) when is_atom(app) do
     "not started application #{app}"
   end
 
-  defp do_format_error({:bad_application, app}) do
+  defp impl_format_error({:bad_application, app}) do
     "bad application: #{inspect(app)}"
   end
 
-  defp do_format_error({:already_loaded, app}) when is_atom(app) do
+  defp impl_format_error({:already_loaded, app}) when is_atom(app) do
     "already loaded application #{app}"
   end
 
-  defp do_format_error({:not_loaded, app}) when is_atom(app) do
+  defp impl_format_error({:not_loaded, app}) when is_atom(app) do
     "not loaded application #{app}"
   end
 
-  defp do_format_error({:invalid_restart_type, restart}) do
+  defp impl_format_error({:invalid_restart_type, restart}) do
     "invalid application restart type: #{inspect(restart)}"
   end
 
-  defp do_format_error({:invalid_name, name}) do
+  defp impl_format_error({:invalid_name, name}) do
     "invalid application name: #{inspect(name)}"
   end
 
-  defp do_format_error({:invalid_options, opts}) do
+  defp impl_format_error({:invalid_options, opts}) do
     "invalid application options: #{inspect(opts)}"
   end
 
-  defp do_format_error({:badstartspec, spec}) do
+  defp impl_format_error({:badstartspec, spec}) do
     "bad application start specs: #{inspect(spec)}"
   end
 
-  defp do_format_error({'no such file or directory', file}) do
+  defp impl_format_error({'no such file or directory', file}) do
     "could not find application file: #{file}"
   end
 
-  defp do_format_error(reason) do
+  defp impl_format_error(reason) do
     Exception.format_exit(reason)
   end
 end

lib/elixir/lib/atom.ex

@@ -1,20 +1,12 @@
 defmodule Atom do
-  @moduledoc """
+  @doc """
   Convenience functions for working with atoms.
-
-  See also `Kernel.is_atom/1`.
   """
 
   @doc """
-  Converts an atom to a string.
+  Converts an atom to string.
 
   Inlined by the compiler.
-
-  ## Examples
-
-      iex> Atom.to_string(:foo)
-      "foo"
-
   """
   @spec to_string(atom) :: String.t
   def to_string(atom) do
@@ -22,24 +14,12 @@ defmodule Atom do
   end
 
   @doc """
-  Converts an atom to a charlist.
+  Converts an atom to a char list.
 
   Inlined by the compiler.
-
-  ## Examples
-
-      iex> Atom.to_charlist(:"An atom")
-      'An atom'
-
   """
-  @spec to_charlist(atom) :: charlist
-  def to_charlist(atom) do
+  @spec to_char_list(atom) :: char_list
+  def to_char_list(atom) do
     :erlang.atom_to_list(atom)
   end
-
-  # TODO: Remove by 2.0
-  # (hard-deprecated in elixir_dispatch)
-  @doc false
-  @spec to_char_list(atom) :: charlist
-  def to_char_list(atom), do: Atom.to_charlist(atom)
 end

lib/elixir/lib/behaviour.ex

@@ -1,27 +1,60 @@
 defmodule Behaviour do
   @moduledoc """
-  This module has been deprecated.
+  Utilities for defining behaviour interfaces.
 
-  Instead of `defcallback/1` and `defmacrocallback/1`, the `@callback` and
-  `@macrocallback` module attributes can be used (respectively). See the
-  documentation for `Module` for more information on these attributes.
+  Behaviours can be referenced by other modules
+  to ensure they implement required callbacks.
 
-  Instead of `MyModule.__behaviour__(:callbacks)`,
-  `MyModule.behaviour_info(:callbacks)` can be used.
+  For example, you can specify the `URI.Parser`
+  behaviour as follows:
+
+      defmodule URI.Parser do
+        use Behaviour
+
+        @doc "Parses the given URL"
+        defcallback parse(uri_info :: URI.t) :: URI.t
+
+        @doc "Defines a default port"
+        defcallback default_port() :: integer
+      end
+
+  And then a module may use it as:
+
+      defmodule URI.HTTP do
+        @behaviour URI.Parser
+        def default_port(), do: 80
+        def parse(info), do: info
+      end
+
+  If the behaviour changes or `URI.HTTP` does
+  not implement one of the callbacks, a warning
+  will be raised.
+
+  ## Implementation
+
+  Since Erlang R15, behaviours must be defined via
+  `@callback` attributes. `defcallback` is a simple
+  mechanism that defines the `@callback` attribute
+  according to the given type specification. `defcallback` allows
+  documentation to be created for the callback and defines
+  a custom function signature.
+
+  The callbacks and their documentation can be retrieved
+  via the `__behaviour__` callback function.
   """
 
   @doc """
-  Defines a function callback according to the given type specification.
+  Define a function callback according to the given type specification.
   """
   defmacro defcallback(spec) do
-    do_defcallback(:def, split_spec(spec, quote(do: term)))
+    do_defcallback(split_spec(spec, quote(do: term)), __CALLER__)
   end
 
   @doc """
-  Defines a macro callback according to the given type specification.
+  Define a macro callback according to the given type specification.
   """
   defmacro defmacrocallback(spec) do
-    do_defcallback(:defmacro, split_spec(spec, quote(do: Macro.t)))
+    do_defmacrocallback(split_spec(spec, quote(do: Macro.t)), __CALLER__)
   end
 
   defp split_spec({:when, _, [{:::, _, [spec, return]}, guard]}, _default) do
@@ -40,17 +73,27 @@ defmodule Behaviour do
     {spec, default, []}
   end
 
-  defp do_defcallback(kind, {spec, return, guards}) do
+  defp do_defcallback({spec, return, guards}, caller) do
     case Macro.decompose_call(spec) do
       {name, args} ->
-        do_callback(kind, name, args, return, guards)
+        do_callback(:def, name, args, name, length(args), args, return, guards, caller)
       _ ->
-        raise ArgumentError, "invalid syntax in #{kind}callback #{Macro.to_string(spec)}"
+        raise ArgumentError, "invalid syntax in defcallback #{Macro.to_string(spec)}"
     end
   end
 
-  defp do_callback(kind, name, args, return, guards) do
-    :lists.foreach fn
+  defp do_defmacrocallback({spec, return, guards}, caller) do
+    case Macro.decompose_call(spec) do
+      {name, args} ->
+        do_callback(:defmacro, :"MACRO-#{name}", [quote(do: env :: Macro.Env.t)|args],
+                    name, length(args), args, return, guards, caller)
+      _ ->
+        raise ArgumentError, "invalid syntax in defmacrocallback #{Macro.to_string(spec)}"
+    end
+  end
+
+  defp do_callback(kind, name, args, docs_name, docs_arity, _docs_args, return, guards, caller) do
+    Enum.each args, fn
       {:::, _, [left, right]} ->
         ensure_not_default(left)
         ensure_not_default(right)
@@ -58,16 +101,12 @@ defmodule Behaviour do
       other ->
         ensure_not_default(other)
         other
-    end, args
+    end
 
-    spec =
-      quote do
-        unquote(name)(unquote_splicing(args)) :: unquote(return) when unquote(guards)
-      end
-
-    case kind do
-      :def -> quote(do: @callback unquote(spec))
-      :defmacro -> quote(do: @macrocallback unquote(spec))
+    quote do
+      @callback unquote(name)(unquote_splicing(args)) :: unquote(return) when unquote(guards)
+      Behaviour.store_docs(__MODULE__, unquote(caller.line), unquote(kind),
+                           unquote(docs_name), unquote(docs_arity))
     end
   end
 
@@ -77,30 +116,37 @@ defmodule Behaviour do
 
   defp ensure_not_default(_), do: :ok
 
+  @doc false
+  def store_docs(module, line, kind, name, arity) do
+    doc = Module.get_attribute module, :doc
+    Module.delete_attribute module, :doc
+    Module.put_attribute module, :behaviour_docs, {{name, arity}, line, kind, doc}
+  end
+
   @doc false
   defmacro __using__(_) do
     quote do
-      warning =
-        "the Behaviour module is deprecated. Instead of using this module, " <>
-        "use the @callback and @macrocallback module attributes. See the " <>
-        "documentation for Module for more information on these attributes"
-      IO.warn(warning)
+      Module.register_attribute(__MODULE__, :behaviour_docs, accumulate: true)
+      @before_compile unquote(__MODULE__)
+      import unquote(__MODULE__)
+    end
+  end
 
+  @doc false
+  defmacro __before_compile__(env) do
+    docs = if Code.compiler_options[:docs] do
+      Enum.reverse Module.get_attribute(env.module, :behaviour_docs)
+    end
+
+    quote do
       @doc false
       def __behaviour__(:callbacks) do
         __MODULE__.behaviour_info(:callbacks)
       end
 
       def __behaviour__(:docs) do
-        for {tuple, line, kind, docs} <- Code.get_docs(__MODULE__, :callback_docs) do
-          case kind do
-            :callback -> {tuple, line, :def, docs}
-            :macrocallback -> {tuple, line, :defmacro, docs}
-          end
-        end
+        unquote(Macro.escape(docs))
       end
-
-      import unquote(__MODULE__)
     end
   end
 end

lib/elixir/lib/bitwise.ex

@@ -1,49 +1,40 @@
 defmodule Bitwise do
   @moduledoc """
-  A set of macros that perform calculations on bits.
+  This module provides macros and operators for bitwise operators.
+  These macros can be used in guards.
 
-  The macros in this module come in two flavors: named or
-  operators. For example:
+  The easiest way to use is to simply import them into
+  your module:
 
       iex> use Bitwise
-      iex> bnot 1   # named
+      iex> bnot 1
       -2
-      iex> 1 &&& 1  # operator
+      iex> 1 &&& 1
       1
 
-  If you prefer to use only operators or skip them, you can
-  pass the following options:
-
-    * `:only_operators` - includes only operators
-    * `:skip_operators` - skips operators
-
-  For example:
+  You can select to include only or skip operators by passing options:
 
       iex> use Bitwise, only_operators: true
       iex> 1 &&& 1
       1
 
-  When invoked with no options, `use Bitwise` is equivalent
-  to `import Bitwise`.
-
-  All bitwise macros can be used in guards:
-
-      iex> use Bitwise
-      iex> odd? = fn int when band(int, 1) == 1 -> true; _ -> false end
-      iex> odd?.(1)
-      true
-
   """
 
-  @doc false
+  @doc """
+  Allow a developer to use this module in their programs with
+  the following options:
+
+    * `:only_operators` - include only operators
+    * `:skip_operators` - skip operators
+
+  """
   defmacro __using__(options) do
     except = cond do
       Keyword.get(options, :only_operators) ->
         [bnot: 1, band: 2, bor: 2, bxor: 2, bsl: 2, bsr: 2]
       Keyword.get(options, :skip_operators) ->
         [~~~: 1, &&&: 2, |||: 2, ^^^: 2, <<<: 2, >>>: 2]
-      true ->
-        []
+      true -> []
     end
 
     quote do
@@ -52,160 +43,84 @@ defmodule Bitwise do
   end
 
   @doc """
-  Calculates the bitwise NOT of its argument.
-
-      iex> bnot(2)
-      -3
-      iex> bnot(2) &&& 3
-      1
-
+  Bitwise not.
   """
   defmacro bnot(expr) do
     quote do: :erlang.bnot(unquote(expr))
   end
 
   @doc """
-  Prefix (unary) operator; calculates the bitwise NOT of its argument.
-
-      iex> ~~~2
-      -3
-      iex> ~~~2 &&& 3
-      1
-
+  Bitwise not as operator.
   """
   defmacro ~~~expr do
     quote do: :erlang.bnot(unquote(expr))
   end
 
   @doc """
-  Calculates the bitwise AND of its arguments.
-
-      iex> band(9, 3)
-      1
-
+  Bitwise and.
   """
   defmacro band(left, right) do
     quote do: :erlang.band(unquote(left), unquote(right))
   end
 
   @doc """
-  Infix operator; calculates the bitwise AND of its arguments.
-
-      iex> 9 &&& 3
-      1
-
+  Bitwise and as operator.
   """
   defmacro left &&& right do
     quote do: :erlang.band(unquote(left), unquote(right))
   end
 
   @doc """
-  Calculates the bitwise OR of its arguments.
-
-      iex> bor(9, 3)
-      11
-
+  Bitwise or.
   """
   defmacro bor(left, right) do
     quote do: :erlang.bor(unquote(left), unquote(right))
   end
 
   @doc """
-  Infix operator; calculates the bitwise OR of its arguments.
-
-      iex> 9 ||| 3
-      11
-
+  Bitwise or as operator.
   """
   defmacro left ||| right do
     quote do: :erlang.bor(unquote(left), unquote(right))
   end
 
   @doc """
-  Calculates the bitwise XOR of its arguments.
-
-      iex> bxor(9, 3)
-      10
-
+  Bitwise xor.
   """
   defmacro bxor(left, right) do
     quote do: :erlang.bxor(unquote(left), unquote(right))
   end
 
   @doc """
-  Infix operator; calculates the bitwise XOR of its arguments.
-
-      iex> 9 ^^^ 3
-      10
-
+  Bitwise xor as operator.
   """
   defmacro left ^^^ right do
     quote do: :erlang.bxor(unquote(left), unquote(right))
   end
 
   @doc """
-  Calculates the result of an arithmetic left bitshift.
-
-      iex> bsl(1, 2)
-      4
-      iex> bsl(1, -2)
-      0
-      iex> bsl(-1, 2)
-      -4
-      iex> bsl(-1, -2)
-      -1
-
+  Arithmetic bitshift left.
   """
   defmacro bsl(left, right) do
     quote do: :erlang.bsl(unquote(left), unquote(right))
   end
 
   @doc """
-  Infix operator; calculates the result of an arithmetic left bitshift.
-
-      iex> 1 <<< 2
-      4
-      iex> 1 <<< -2
-      0
-      iex> -1 <<< 2
-      -4
-      iex> -1 <<< -2
-      -1
-
+  Arithmetic bitshift left as operator.
   """
   defmacro left <<< right do
     quote do: :erlang.bsl(unquote(left), unquote(right))
   end
 
   @doc """
-  Calculates the result of an arithmetic right bitshift.
-
-      iex> bsr(1, 2)
-      0
-      iex> bsr(1, -2)
-      4
-      iex> bsr(-1, 2)
-      -1
-      iex> bsr(-1, -2)
-      -4
-
+  Arithmetic bitshift right.
   """
   defmacro bsr(left, right) do
     quote do: :erlang.bsr(unquote(left), unquote(right))
   end
 
   @doc """
-  Infix operator; calculates the result of an arithmetic right bitshift.
-
-      iex> 1 >>> 2
-      0
-      iex> 1 >>> -2
-      4
-      iex> -1 >>> 2
-      -1
-      iex> -1 >>> -2
-      -4
-
+  Arithmetic bitshift right as operator.
   """
   defmacro left >>> right do
     quote do: :erlang.bsr(unquote(left), unquote(right))

lib/elixir/lib/calendar.ex

@@ -1,196 +0,0 @@
-defmodule Calendar do
-  @moduledoc """
-  This module defines the responsibilities for working with
-  calendars, dates, times and datetimes in Elixir.
-
-  Currently it defines types and the minimal implementation
-  for a calendar behaviour in Elixir. The goal of the Calendar
-  features in Elixir is to provide a base for interoperability
-  instead of full-featured datetime API.
-
-  For the actual date, time and datetime structures, see `Date`,
-  `Time`, `NaiveDateTime` and `DateTime`.
-
-  Note the year, month, day, etc. designations are overspecified
-  (i.e. an integer instead of `1..12` for months) because different
-  calendars may have a different number of days per month, months per year and so on.
-  """
-
-  @type year :: integer
-  @type month :: integer
-  @type day :: integer
-  @type hour :: integer
-  @type minute :: integer
-  @type second :: integer
-
-  @typedoc """
-  The internal time format is used when converting between calendars.
-
-  It represents time as a fraction of a day (starting from midnight).
-  `parts_in_day` specifies how much of the day is already passed,
-  while `parts_per_day` signifies how many parts there fit in a day.
-  """
-  @type day_fraction :: {parts_in_day :: non_neg_integer, parts_per_day :: pos_integer}
-
-  @typedoc """
-  The internal date format that is used when converting between calendars.
-
-  This is the amount of days including the fractional part that has passed of
-  the last day since 0000-01-01+00:00T00:00.00000 in ISO 8601 notation (also
-  known as midnight 1 January BC 1 of the Proleptic Gregorian Calendar).
-
-  The `parts_per_day` represent how many subparts the current day is subdivided in
-  (for different calendars, picking a different `parts_per_day` might make sense).
-  The `parts_in_day` represents how many of these `parts_per_day` have passed in the
-  last day.
-  """
-  @type iso_days :: {days :: integer, day_fraction}
-
-  @typedoc """
-  Microseconds with stored precision.
-
-  The precision represents the number of digits that must be used when
-  representing the microseconds to external format. If the precision is 0,
-  it means microseconds must be skipped.
-  """
-  @type microsecond :: {0..999_999, 0..6}
-
-  @typedoc "A calendar implementation"
-  @type calendar :: module
-
-  @typedoc "The time zone ID according to the IANA tz database (e.g. Europe/Zurich)"
-  @type time_zone :: String.t
-
-  @typedoc "The time zone abbreviation (e.g. CET or CEST or BST etc.)"
-  @type zone_abbr :: String.t
-
-  @typedoc "The time zone UTC offset in seconds"
-  @type utc_offset :: integer
-
-  @typedoc "The time zone standard offset in seconds (not zero in summer times)"
-  @type std_offset :: integer
-
-  @typedoc "Any map/struct that contains the date fields"
-  @type date :: %{optional(any) => any, calendar: calendar, year: year, month: month, day: day}
-
-  @typedoc "Any map/struct that contains the time fields"
-  @type time :: %{optional(any) => any, hour: hour, minute: minute, second: second, microsecond: microsecond}
-
-  @typedoc "Any map/struct that contains the naive_datetime fields"
-  @type naive_datetime :: %{optional(any) => any, calendar: calendar, year: year, month: month, day: day,
-                            hour: hour, minute: minute, second: second, microsecond: microsecond}
-
-  @typedoc "Any map/struct that contains the datetime fields"
-  @type datetime :: %{optional(any) => any, calendar: calendar, year: year, month: month, day: day,
-                      hour: hour, minute: minute, second: second, microsecond: microsecond,
-                      time_zone: time_zone, zone_abbr: zone_abbr, utc_offset: utc_offset, std_offset: std_offset}
-
-  @doc """
-  Returns how many days there are in the given year-month.
-  """
-  @callback days_in_month(year, month) :: day
-
-  @doc """
-  Returns true if the given year is a leap year.
-
-  A leap year is a year of a longer length than normal. The exact meaning
-  is up to the calendar. A calendar must return `false` if it does not support
-  the concept of leap years.
-  """
-  @callback leap_year?(year) :: boolean
-
-  @doc """
-  Calculates the day of the week from the given `year`, `month`, and `day`.
-  """
-  @callback day_of_week(year, month, day) :: non_neg_integer()
-
-  @doc """
-  Converts the date into a string according to the calendar.
-  """
-  @callback date_to_string(year, month, day) :: String.t
-
-  @doc """
-  Converts the datetime (without time zone) into a string according to the calendar.
-  """
-  @callback naive_datetime_to_string(year, month, day, hour, minute, second, microsecond) :: String.t
-
-  @doc """
-  Converts the datetime (with time zone) into a string according to the calendar.
-  """
-  @callback datetime_to_string(year, month, day, hour, minute, second, microsecond,
-                               time_zone, zone_abbr, utc_offset, std_offset) :: String.t
-
-  @doc """
-  Converts the time into a string according to the calendar.
-  """
-  @callback time_to_string(hour, minute, second, microsecond) :: String.t
-
-  @doc """
-  Converts the given datetime (with time zone) into the `t:iso_days` format.
-  """
-  @callback naive_datetime_to_iso_days(year, month, day, hour, minute, second, microsecond) :: iso_days
-
-  @doc """
-  Converts `t:iso_days` to the Calendar's datetime format.
-  """
-  @callback naive_datetime_from_iso_days(iso_days) :: {year, month, day, hour, minute, second, microsecond}
-
-  @doc """
-  Converts the given time to the `t:day_fraction` format.
-  """
-  @callback time_to_day_fraction(hour, minute, second, microsecond) :: day_fraction
-
-  @doc """
-  Converts `t:day_fraction` to the Calendar's time format.
-  """
-  @callback time_from_day_fraction(day_fraction) :: {hour, minute, second, microsecond}
-
-  @doc """
-  Define the rollover moment for the given calendar.
-
-  This is the moment, in your calendar, when the current day ends
-  and the next day starts.
-
-  The result of this function is used to check if two calendars rollover at
-  the same time of day. If they do not, we can only convert datetimes and times
-  between them. If they do, this means that we can also convert dates as well
-  as naive datetimes between them.
-
-  This day fraction should be in its most simplified form possible, to make comparisons fast.
-
-  ## Examples
-
-    * If, in your Calendar, a new day starts at midnight, return {0, 1}.
-    * If, in your Calendar, a new day starts at sunrise, return {1, 4}.
-    * If, in your Calendar, a new day starts at noon, return {1, 2}.
-    * If, in your Calendar, a new day starts at sunset, return {3, 4}.
-
-  """
-  @callback day_rollover_relative_to_midnight_utc() :: day_fraction
-
-  @doc """
-  Should return `true` if the given date describes a proper date in the calendar.
-  """
-  @callback valid_date?(year, month, day) :: boolean
-
-  @doc """
-  Should return `true` if the given time describes a proper time in the calendar.
-  """
-  @callback valid_time?(hour, minute, second, microsecond) :: boolean
-
-  # General Helpers
-
-  @doc """
-  Returns `true` if two calendars have the same moment of starting a new day,
-  `false` otherwise.
-
-  If two calendars are not compatible, we can only convert datetimes and times
-  between them. If they are compatible, this means that we can also convert
-  dates as well as naive datetimes between them.
-  """
-  @spec compatible_calendars?(Calendar.calendar, Calendar.calendar) :: boolean
-  def compatible_calendars?(calendar, calendar), do: true
-  def compatible_calendars?(calendar1, calendar2) do
-    calendar1.day_rollover_relative_to_midnight_utc() == calendar2.day_rollover_relative_to_midnight_utc()
-  end
-end

lib/elixir/lib/calendar/date.ex

@@ -1,603 +0,0 @@
-defmodule Date do
-  @moduledoc """
-  A Date struct and functions.
-
-  The Date struct contains the fields year, month, day and calendar.
-  New dates can be built with the `new/3` function or using the `~D`
-  sigil:
-
-      iex> ~D[2000-01-01]
-      ~D[2000-01-01]
-
-  Both `new/3` and sigil return a struct where the date fields can
-  be accessed directly:
-
-      iex> date = ~D[2000-01-01]
-      iex> date.year
-      2000
-      iex> date.month
-      1
-
-  The functions on this module work with the `Date` struct as well
-  as any struct that contains the same fields as the `Date` struct,
-  such as `NaiveDateTime` and `DateTime`. Such functions expect
-  `t:Calendar.date/0` in their typespecs (instead of `t:t/0`).
-
-  Developers should avoid creating the Date structs directly
-  and instead rely on the functions provided by this module as well
-  as the ones in 3rd party calendar libraries.
-
-  ## Comparing dates
-
-  Comparisons in Elixir using `==`, `>`, `<` and similar are structural
-  and based on the `Date` struct fields. For proper comparison between
-  dates, use the `compare/2` function.
-
-  ## Using epochs
-
-  The `add/2` and `diff/2` functions can be used for computing dates
-  or retrieving the amount of days betweens instants. For example, if there
-  is an interest in computing the amount of days from the Unix epoch
-  (1970-01-01):
-
-      iex> Date.diff(~D[2010-04-17], ~D[1970-01-01])
-      14716
-
-      iex> Date.add(~D[1970-01-01], 14716)
-      ~D[2010-04-17]
-
-  Those functions are optimized to deal with common epochs, such
-  as the Unix Epoch above or the Gregorian Epoch (0000-01-01).
-  """
-
-  @enforce_keys [:year, :month, :day]
-  defstruct [:year, :month, :day, calendar: Calendar.ISO]
-
-  @type t :: %Date{year: Calendar.year, month: Calendar.month,
-                   day: Calendar.day, calendar: Calendar.calendar}
-
-  @doc """
-  Returns a range of dates.
-
-  A range of dates represents a discrete number of dates where
-  the first and last values are dates with matching calendars.
-
-  Ranges of dates can be either increasing (`first <= last`) or
-  decreasing (`first > last`). They are also always inclusive.
-
-  ## Examples
-
-      iex> Date.range(~D[1999-01-01], ~D[2000-01-01])
-      #DateRange<~D[1999-01-01], ~D[2000-01-01]>
-
-      iex> Date.range(~N[2000-01-01 09:00:00], ~D[1999-01-01])
-      #DateRange<~N[2000-01-01 09:00:00], ~D[1999-01-01]>
-
-  A range of dates implements the `Enumerable` protocol, which means
-  functions in the `Enum` module can be used to work with
-  ranges:
-
-      iex> range = Date.range(~D[2001-01-01], ~D[2002-01-01])
-      iex> Enum.count(range)
-      366
-      iex> Enum.member?(range, ~D[2001-02-01])
-      true
-      iex> Enum.reduce(range, 0, fn _date, acc -> acc - 1 end)
-      -366
-  """
-
-  @spec range(Calendar.date, Calendar.date) :: Date.Range.t
-  def range(%{calendar: calendar} = first, %{calendar: calendar} = last) do
-    {first_days, _} = to_iso_days(first)
-    {last_days, _} = to_iso_days(last)
-
-    %Date.Range{
-      first: first,
-      last: last,
-      first_in_iso_days: first_days,
-      last_in_iso_days: last_days,
-    }
-  end
-
-  def range(%{calendar: _, year: _, month: _, day: _},
-            %{calendar: _, year: _, month: _, day: _}) do
-    raise ArgumentError, "both dates must have matching calendars"
-  end
-
-  @doc """
-  Returns the current date in UTC.
-
-  ## Examples
-
-      iex> date = Date.utc_today()
-      iex> date.year >= 2016
-      true
-
-  """
-  @spec utc_today(Calendar.calendar) :: t
-  def utc_today(calendar \\ Calendar.ISO)
-
-  def utc_today(Calendar.ISO) do
-    {:ok, {year, month, day}, _, _} = Calendar.ISO.from_unix(System.os_time, :native)
-    %Date{year: year, month: month, day: day}
-  end
-
-  def utc_today(calendar) do
-    calendar
-    |> DateTime.utc_now
-    |> DateTime.to_date
-  end
-
-  @doc """
-  Returns true if the year in the given `date` is a leap year.
-
-  ## Examples
-
-      iex> Date.leap_year?(~D[2000-01-01])
-      true
-      iex> Date.leap_year?(~D[2001-01-01])
-      false
-      iex> Date.leap_year?(~D[2004-01-01])
-      true
-      iex> Date.leap_year?(~D[1900-01-01])
-      false
-      iex> Date.leap_year?(~N[2004-01-01 01:23:45])
-      true
-
-  """
-  @spec leap_year?(Calendar.date) :: boolean()
-  def leap_year?(date)
-
-  def leap_year?(%{calendar: calendar, year: year}) do
-    calendar.leap_year?(year)
-  end
-
-  @doc """
-  Returns the number of days in the given `date` month.
-
-  ## Examples
-
-      iex> Date.days_in_month(~D[1900-01-13])
-      31
-      iex> Date.days_in_month(~D[1900-02-09])
-      28
-      iex> Date.days_in_month(~N[2000-02-20 01:23:45])
-      29
-
-  """
-  @spec days_in_month(Calendar.date) :: Calendar.day
-  def days_in_month(date)
-
-  def days_in_month(%{calendar: calendar, year: year, month: month}) do
-    calendar.days_in_month(year, month)
-  end
-
-  @doc """
-  Builds a new ISO date.
-
-  Expects all values to be integers. Returns `{:ok, date}` if each
-  entry fits its appropriate range, returns `{:error, reason}` otherwise.
-
-  ## Examples
-
-      iex> Date.new(2000, 1, 1)
-      {:ok, ~D[2000-01-01]}
-      iex> Date.new(2000, 13, 1)
-      {:error, :invalid_date}
-      iex> Date.new(2000, 2, 29)
-      {:ok, ~D[2000-02-29]}
-
-      iex> Date.new(2000, 2, 30)
-      {:error, :invalid_date}
-      iex> Date.new(2001, 2, 29)
-      {:error, :invalid_date}
-
-  """
-  @spec new(Calendar.year, Calendar.month, Calendar.day) :: {:ok, t} | {:error, atom}
-  def new(year, month, day, calendar \\ Calendar.ISO) do
-    if calendar.valid_date?(year, month, day) do
-      {:ok, %Date{year: year, month: month, day: day, calendar: calendar}}
-    else
-      {:error, :invalid_date}
-    end
-  end
-
-  @doc """
-  Converts the given date to a string according to its calendar.
-
-  ### Examples
-
-      iex> Date.to_string(~D[2000-02-28])
-      "2000-02-28"
-      iex> Date.to_string(~N[2000-02-28 01:23:45])
-      "2000-02-28"
-
-  """
-  @spec to_string(Calendar.date) :: String.t
-  def to_string(date)
-
-  def to_string(%{calendar: calendar, year: year, month: month, day: day}) do
-    calendar.date_to_string(year, month, day)
-  end
-
-  @doc """
-  Parses the extended "Date and time of day" format described by
-  [ISO 8601:2004](https://en.wikipedia.org/wiki/ISO_8601).
-
-  Timezone offset may be included in the string but they will be
-  simply discarded as such information is not included in naive date
-  times.
-
-  Time representations with reduced accuracy are not supported.
-
-  ## Examples
-
-      iex> Date.from_iso8601("2015-01-23")
-      {:ok, ~D[2015-01-23]}
-
-      iex> Date.from_iso8601("2015:01:23")
-      {:error, :invalid_format}
-
-      iex> Date.from_iso8601("2015-01-32")
-      {:error, :invalid_date}
-
-  """
-  @spec from_iso8601(String.t) :: {:ok, t} | {:error, atom}
-  def from_iso8601(string, calendar \\ Calendar.ISO)
-
-  def from_iso8601(<<year::4-bytes, ?-, month::2-bytes, ?-, day::2-bytes>>, calendar) do
-    with {year, ""} <- Integer.parse(year),
-         {month, ""} <- Integer.parse(month),
-         {day, ""} <- Integer.parse(day) do
-      with {:ok, date} <- new(year, month, day, Calendar.ISO),
-           do: convert(date, calendar)
-    else
-      _ -> {:error, :invalid_format}
-    end
-  end
-
-  def from_iso8601(<<_::binary>>, _calendar) do
-    {:error, :invalid_format}
-  end
-
-  @doc """
-  Parses the extended "Date and time of day" format described by
-  [ISO 8601:2004](https://en.wikipedia.org/wiki/ISO_8601).
-
-  Raises if the format is invalid.
-
-  ## Examples
-
-      iex> Date.from_iso8601!("2015-01-23")
-      ~D[2015-01-23]
-      iex> Date.from_iso8601!("2015:01:23")
-      ** (ArgumentError) cannot parse "2015:01:23" as date, reason: :invalid_format
-  """
-  @spec from_iso8601!(String.t) :: t
-  def from_iso8601!(string, calendar \\ Calendar.ISO) do
-    case from_iso8601(string, calendar) do
-      {:ok, value} ->
-        value
-      {:error, reason} ->
-        raise ArgumentError, "cannot parse #{inspect string} as date, reason: #{inspect reason}"
-    end
-  end
-
-  @doc """
-  Converts the given `date` to
-  [ISO 8601:2004](https://en.wikipedia.org/wiki/ISO_8601).
-
-  By default, `Date.to_iso8601/2` returns dates formatted in the "extended"
-  format, for human readability. It also supports the "basic" format through passing the `:basic` option.
-
-  Only supports converting dates which are in the ISO calendar,
-  or other calendars in which the days also start at midnight.
-  Attempting to convert dates from other calendars will raise an `ArgumentError`.
-
-  ### Examples
-
-      iex> Date.to_iso8601(~D[2000-02-28])
-      "2000-02-28"
-
-      iex> Date.to_iso8601(~D[2000-02-28], :basic)
-      "20000228"
-
-      iex> Date.to_iso8601(~N[2000-02-28 00:00:00])
-      "2000-02-28"
-
-  """
-  @spec to_iso8601(Calendar.date, :extended | :basic) :: String.t
-  def to_iso8601(date, format \\ :extended) when format in [:basic, :extended] do
-    %{year: year, month: month, day: day} = convert!(date, Calendar.ISO)
-    Calendar.ISO.date_to_iso8601(year, month, day, format)
-  end
-
-  @doc """
-  Converts the given `date` to an Erlang date tuple.
-
-  Only supports converting dates which are in the ISO calendar,
-  or other calendars in which the days also start at midnight.
-  Attempting to convert dates from other calendars will raise.
-
-  ## Examples
-
-      iex> Date.to_erl(~D[2000-01-01])
-      {2000, 1, 1}
-
-      iex> Date.to_erl(~N[2000-01-01 00:00:00])
-      {2000, 1, 1}
-
-  """
-  @spec to_erl(Calendar.date) :: :calendar.date
-  def to_erl(date) do
-    %{year: year, month: month, day: day} = convert!(date, Calendar.ISO)
-    {year, month, day}
-  end
-
-  @doc """
-  Converts an Erlang date tuple to a `Date` struct.
-
-  Only supports converting dates which are in the ISO calendar,
-  or other calendars in which the days also start at midnight.
-  Attempting to convert dates from other calendars will return an error tuple.
-
-  ## Examples
-
-      iex> Date.from_erl({2000, 1, 1})
-      {:ok, ~D[2000-01-01]}
-      iex> Date.from_erl({2000, 13, 1})
-      {:error, :invalid_date}
-
-  """
-  @spec from_erl(:calendar.date) :: {:ok, t} | {:error, atom}
-  def from_erl(tuple, calendar \\ Calendar.ISO)
-
-  def from_erl({year, month, day}, calendar) do
-    with {:ok, date} <- new(year, month, day, Calendar.ISO),
-         do: convert(date, calendar)
-  end
-
-  @doc """
-  Converts an Erlang date tuple but raises for invalid dates.
-
-  ## Examples
-
-      iex> Date.from_erl!({2000, 1, 1})
-      ~D[2000-01-01]
-      iex> Date.from_erl!({2000, 13, 1})
-      ** (ArgumentError) cannot convert {2000, 13, 1} to date, reason: :invalid_date
-
-  """
-  @spec from_erl!(:calendar.date) :: t
-  def from_erl!(tuple) do
-    case from_erl(tuple) do
-      {:ok, value} ->
-        value
-      {:error, reason} ->
-        raise ArgumentError, "cannot convert #{inspect tuple} to date, reason: #{inspect reason}"
-    end
-  end
-
-  @doc """
-  Compares two date structs.
-
-  Returns `:gt` if first date is later than the second
-  and `:lt` for vice versa. If the two dates are equal
-  `:eq` is returned.
-
-  ## Examples
-
-      iex> Date.compare(~D[2016-04-16], ~D[2016-04-28])
-      :lt
-
-  This function can also be used to compare across more
-  complex calendar types by considering only the date fields:
-
-      iex> Date.compare(~D[2016-04-16], ~N[2016-04-28 01:23:45])
-      :lt
-      iex> Date.compare(~D[2016-04-16], ~N[2016-04-16 01:23:45])
-      :eq
-      iex> Date.compare(~N[2016-04-16 12:34:56], ~N[2016-04-16 01:23:45])
-      :eq
-
-  """
-  @spec compare(Calendar.date, Calendar.date) :: :lt | :eq | :gt
-  def compare(%{calendar: calendar, year: year1, month: month1, day: day1},
-              %{calendar: calendar, year: year2, month: month2, day: day2}) do
-    case {{year1, month1, day1}, {year2, month2, day2}} do
-      {first, second} when first > second -> :gt
-      {first, second} when first < second -> :lt
-      _ -> :eq
-    end
-  end
-  def compare(date1, date2) do
-    if Calendar.compatible_calendars?(date1.calendar, date2.calendar) do
-      case {to_iso_days(date1), to_iso_days(date2)} do
-        {first, second} when first > second -> :gt
-        {first, second} when first < second -> :lt
-        _ -> :eq
-      end
-    else
-      raise ArgumentError, """
-      cannot compare #{inspect date1} with #{inspect date2}.
-
-      This comparison would be ambiguous as their calendars have incompatible day rollover moments.
-      Specify an exact time of day (using `DateTime`s) to resolve this ambiguity
-      """
-    end
-  end
-
-  @doc """
-  Converts the given `date` from it's calendar to the given `calendar`.
-
-  Returns `{:ok, date}` if the calendars are compatible,
-  or `{:error, :incompatible_calendars}` if they are not.
-
-  See also `Calendar.compatible_calendars?/2`.
-
-  ## Examples
-
-  Imagine someone implements `Calendar.Holocene`, a calendar based on the
-  Gregorian calendar that adds exactly 10,000 years to the current Gregorian
-  year:
-
-      iex> Date.convert(~D[2000-01-01], Calendar.Holocene)
-      {:ok, %Date{calendar: Calendar.Holocene, year: 12000, month: 1, day: 1}}
-
-  """
-  @spec convert(Calendar.date, Calendar.calendar) :: {:ok, t} | {:error, :incompatible_calendars}
-  def convert(%{calendar: calendar, year: year, month: month, day: day}, calendar) do
-    {:ok, %Date{calendar: calendar, year: year, month: month, day: day}}
-  end
-  def convert(%{calendar: calendar} = date, target_calendar) do
-    if Calendar.compatible_calendars?(calendar, target_calendar) do
-      result_date =
-        date
-        |> to_iso_days()
-        |> from_iso_days(target_calendar)
-      {:ok, result_date}
-    else
-      {:error, :incompatible_calendars}
-    end
-  end
-
-  @doc """
-  Similar to `Date.convert/2`, but raises an `ArgumentError`
-  if the conversion between the two calendars is not possible.
-
-  ## Examples
-
-  Imagine someone implements `Calendar.Holocene`, a calendar based on the
-  Gregorian calendar that adds exactly 10,000 years to the current Gregorian
-  year:
-
-      iex> Date.convert!(~D[2000-01-01], Calendar.Holocene)
-      %Date{calendar: Calendar.Holocene, year: 12000, month: 1, day: 1}
-
-  """
-  @spec convert!(Calendar.date, Calendar.calendar) :: t
-  def convert!(date, calendar) do
-    case convert(date, calendar) do
-      {:ok, value} ->
-        value
-      {:error, reason} ->
-        raise ArgumentError, "cannot convert #{inspect date} to target calendar #{inspect calendar}, reason: #{inspect reason}"
-    end
-  end
-
-  @doc """
-  Adds the number of days to the given `date`.
-
-  The days are counted as gregorian days. The date is returned in the same
-  calendar as it was given in.
-
-  ## Examples
-
-      iex> Date.add(~D[2000-01-03], -2)
-      ~D[2000-01-01]
-      iex> Date.add(~D[2000-01-01], 2)
-      ~D[2000-01-03]
-
-      iex> Date.add(~N[2000-01-01 09:00:00], 2)
-      ~D[2000-01-03]
-
-  """
-  @spec add(Calendar.date, integer()) :: t
-  def add(%{calendar: calendar} = date, days) do
-    {iso_days_days, fraction} = to_iso_days(date)
-    from_iso_days({iso_days_days + days, fraction}, calendar)
-  end
-
-  @doc """
-  Calculates the difference between two dates, in a full number of days.
-
-  It returns the number of gregorian days between the dates. Only `Date`
-  structs that follow the same or compatible calendars can be compared
-  this way. If two calendars are not compatible, it will raise.
-
-  ## Examples
-
-      iex> Date.diff(~D[2000-01-03], ~D[2000-01-01])
-      2
-      iex> Date.diff(~D[2000-01-01], ~D[2000-01-03])
-      -2
-
-      iex> Date.diff(~D[2000-01-01], ~N[2000-01-03 09:00:00])
-      -2
-
-  """
-  @spec diff(Calendar.date, Calendar.date) :: integer
-  def diff(%{calendar: Calendar.ISO, year: year1, month: month1, day: day1},
-           %{calendar: Calendar.ISO, year: year2, month: month2, day: day2}) do
-    Calendar.ISO.date_to_iso_days_days(year1, month1, day1) -
-      Calendar.ISO.date_to_iso_days_days(year2, month2, day2)
-  end
-
-  def diff(%{calendar: calendar1} = date1, %{calendar: calendar2} = date2) do
-    if Calendar.compatible_calendars?(calendar1, calendar2) do
-      {days1, _} = to_iso_days(date1)
-      {days2, _} = to_iso_days(date2)
-      days1 - days2
-    else
-      raise ArgumentError, "cannot calculate the difference between #{inspect date1} and #{inspect date2} because their calendars are not compatible and thus the result would be ambiguous"
-    end
-  end
-
-  defp to_iso_days(%{calendar: Calendar.ISO, year: year, month: month, day: day}) do
-    {Calendar.ISO.date_to_iso_days_days(year, month, day), {0, 86400000000}}
-  end
-  defp to_iso_days(%{calendar: calendar, year: year, month: month, day: day}) do
-    calendar.naive_datetime_to_iso_days(year, month, day, 0, 0, 0, {0, 0})
-  end
-
-  defp from_iso_days({days, _}, Calendar.ISO) do
-    {year, month, day} = Calendar.ISO.date_from_iso_days_days(days)
-    %Date{year: year, month: month, day: day, calendar: Calendar.ISO}
-  end
-  defp from_iso_days(iso_days, target_calendar) do
-    {year, month, day, _, _, _, _} = target_calendar.naive_datetime_from_iso_days(iso_days)
-    %Date{year: year, month: month, day: day, calendar: target_calendar}
-  end
-
-  @doc """
-  Calculates the day of the week of a given `date`.
-
-  Returns the day of the week as an integer. For the ISO 8601
-  calendar (the default), it is an integer from 1 to 7, where
-  1 is Monday and 7 is Sunday.
-
-  ## Examples
-
-      iex> Date.day_of_week(~D[2016-10-31])
-      1
-      iex> Date.day_of_week(~D[2016-11-01])
-      2
-      iex> Date.day_of_week(~N[2016-11-01 01:23:45])
-      2
-
-  """
-  @spec day_of_week(Calendar.date) :: non_neg_integer()
-  def day_of_week(date)
-
-  def day_of_week(%{calendar: calendar, year: year, month: month, day: day}) do
-    calendar.day_of_week(year, month, day)
-  end
-
-  ## Helpers
-
-  defimpl String.Chars do
-    def to_string(%{calendar: calendar, year: year, month: month, day: day}) do
-      calendar.date_to_string(year, month, day)
-    end
-  end
-
-  defimpl Inspect do
-    def inspect(%{calendar: Calendar.ISO, year: year, month: month, day: day}, _) do
-      "~D[" <> Calendar.ISO.date_to_string(year, month, day) <> "]"
-    end
-
-    def inspect(date, opts) do
-      Inspect.Any.inspect(date, opts)
-    end
-  end
-end

lib/elixir/lib/calendar/date_range.ex

@@ -1,86 +0,0 @@
-defmodule Date.Range do
-  @moduledoc """
-  Returns an inclusive range between dates.
-
-  Ranges must be created with the `Date.range/2` function.
-
-  The following fields are public:
-
-    * `:first` - the initial date on the range
-    * `:last` - the last date on the range
-
-  The remaining fields are private and should not be accessed.
-  """
-
-  @type t :: %__MODULE__{first: Date.t, last: Date.t,
-                         first_in_iso_days: Calendar.days,
-                         last_in_iso_days: Calendar.days}
-
-  defstruct [:first, :last, :first_in_iso_days, :last_in_iso_days]
-
-  defimpl Enumerable do
-    def member?(%{first: %{calendar: calendar, year: first_year, month: first_month, day: first_day},
-                  last: %{calendar: calendar, year: last_year, month: last_month, day: last_day},
-                  first_in_iso_days: first_in_iso_days, last_in_iso_days: last_in_iso_days},
-                %Date{calendar: calendar, year: year, month: month, day: day}) do
-      first = {first_year, first_month, first_day}
-      last = {last_year, last_month, last_day}
-      date = {year, month, day}
-
-      if first_in_iso_days <= last_in_iso_days do
-        {:ok, date >= first and date <= last}
-      else
-        {:ok, date >= last and date <= first}
-      end
-    end
-
-    def member?(_, _) do
-      {:ok, false}
-    end
-
-    def count(%Date.Range{first_in_iso_days: first_in_iso_days, last_in_iso_days: last_in_iso_days}) do
-      {:ok, abs(first_in_iso_days - last_in_iso_days) + 1}
-    end
-
-    def reduce(%Date.Range{first_in_iso_days: first_in_iso_days, last_in_iso_days: last_in_iso_days,
-                           first: %{calendar: calendar}}, acc, fun) do
-      reduce(first_in_iso_days, last_in_iso_days, acc, fun, calendar, first_in_iso_days <= last_in_iso_days)
-    end
-
-    defp reduce(_x, _y, {:halt, acc}, _fun, _calendar, _up?) do
-      {:halted, acc}
-    end
-
-    defp reduce(x, y, {:suspend, acc}, fun, calendar, up?) do
-      {:suspended, acc, &reduce(x, y, &1, fun, calendar, up?)}
-    end
-
-    defp reduce(x, y, {:cont, acc}, fun, calendar, up? = true) when x <= y do
-      reduce(x + 1, y, fun.(date_from_iso_days_days(x, calendar), acc), fun, calendar, up?)
-    end
-
-    defp reduce(x, y, {:cont, acc}, fun, calendar, up? = false) when x >= y do
-      reduce(x - 1, y, fun.(date_from_iso_days_days(x, calendar), acc), fun, calendar, up?)
-    end
-
-    defp reduce(_, _, {:cont, acc}, _fun, _calendar, _up) do
-      {:done, acc}
-    end
-
-    defp date_from_iso_days_days(days, Calendar.ISO) do
-      {year, month, day} = Calendar.ISO.date_from_iso_days_days(days)
-      %Date{year: year, month: month, day: day, calendar: Calendar.ISO}
-    end
-
-    defp date_from_iso_days_days(days, calendar) do
-      {year, month, day, _, _, _, _} = calendar.naive_datetime_from_iso_days({days, {0, 86400000000}})
-      %Date{year: year, month: month, day: day, calendar: calendar}
-    end
-  end
-
-  defimpl Inspect do
-    def inspect(%Date.Range{first: first, last: last}, _) do
-      "#DateRange<" <> inspect(first) <> ", " <> inspect(last) <> ">"
-    end
-  end
-end

lib/elixir/lib/calendar/datetime.ex

@@ -1,670 +0,0 @@
-defmodule DateTime do
-  @moduledoc """
-  A datetime implementation with a time zone.
-
-  This datetime can be seen as an ephemeral snapshot
-  of a datetime at a given time zone. For such purposes,
-  it also includes both UTC and Standard offsets, as
-  well as the zone abbreviation field used exclusively
-  for formatting purposes.
-
-  Remember, comparisons in Elixir using `==`, `>`, `<` and friends
-  are structural and based on the DateTime struct fields. For proper
-  comparison between datetimes, use the `compare/2` function.
-
-  The functions on this module work with the `DateTime` struct as well
-  as any struct that contains the same fields as the `DateTime` struct.
-  Such functions expect `t:Calendar.datetime/0` in their typespecs
-  (instead of `t:t/0`).
-
-  Developers should avoid creating the DateTime struct directly
-  and instead rely on the functions provided by this module as
-  well as the ones in 3rd party calendar libraries.
-
-  ## Where are my functions?
-
-  You will notice this module only contains conversion
-  functions as well as functions that work on UTC. This
-  is because a proper DateTime implementation requires a
-  TimeZone database which currently is not provided as part
-  of Elixir.
-
-  Such may be addressed in upcoming versions, meanwhile,
-  use 3rd party packages to provide DateTime building and
-  similar functionality with time zone backing.
-  """
-
-  @enforce_keys [:year, :month, :day, :hour, :minute, :second,
-                 :time_zone, :zone_abbr, :utc_offset, :std_offset]
-  defstruct [:year, :month, :day, :hour, :minute, :second, :time_zone,
-             :zone_abbr, :utc_offset, :std_offset, microsecond: {0, 0}, calendar: Calendar.ISO]
-
-  @type t :: %__MODULE__{year: Calendar.year, month: Calendar.month, day: Calendar.day,
-                         calendar: Calendar.calendar, hour: Calendar.hour, minute: Calendar.minute,
-                         second: Calendar.second, microsecond: Calendar.microsecond,
-                         time_zone: Calendar.time_zone, zone_abbr: Calendar.zone_abbr,
-                         utc_offset: Calendar.utc_offset, std_offset: Calendar.std_offset}
-
-  @unix_days :calendar.date_to_gregorian_days({1970, 1, 1})
-
-  @doc """
-  Returns the current datetime in UTC.
-
-  ## Examples
-
-      iex> datetime = DateTime.utc_now()
-      iex> datetime.time_zone
-      "Etc/UTC"
-
-  """
-  @spec utc_now(Calendar.calendar) :: t
-  def utc_now(calendar \\ Calendar.ISO) do
-    System.os_time |> from_unix!(:native, calendar)
-  end
-
-  @doc """
-  Converts the given Unix time to `DateTime`.
-
-  The integer can be given in different unit
-  according to `System.convert_time_unit/3` and it will
-  be converted to microseconds internally.
-
-  Unix times are always in UTC and therefore the DateTime
-  will be returned in UTC.
-
-  ## Examples
-
-      iex> {:ok, datetime} = DateTime.from_unix(1464096368)
-      iex> datetime
-      #DateTime<2016-05-24 13:26:08Z>
-
-      iex> {:ok, datetime} = DateTime.from_unix(1432560368868569, :microsecond)
-      iex> datetime
-      #DateTime<2015-05-25 13:26:08.868569Z>
-
-  The unit can also be an integer as in `t:System.time_unit/0`:
-
-      iex> {:ok, datetime} = DateTime.from_unix(143256036886856, 1024)
-      iex> datetime
-      #DateTime<6403-03-17 07:05:22.320Z>
-
-  Negative Unix times are supported, up to -62167219200 seconds,
-  which is equivalent to "0000-01-01T00:00:00Z" or 0 Gregorian seconds.
-  """
-  @spec from_unix(integer, :native | System.time_unit, Calendar.calendar) :: {:ok, t} | {:error, atom}
-  def from_unix(integer, unit \\ :second, calendar \\ Calendar.ISO) when is_integer(integer) do
-    case Calendar.ISO.from_unix(integer, unit) do
-      {:ok, {year, month, day}, {hour, minute, second}, microsecond} ->
-        iso_datetime = %DateTime{year: year, month: month, day: day,
-                                 hour: hour, minute: minute, second: second, microsecond: microsecond,
-                                 std_offset: 0, utc_offset: 0, zone_abbr: "UTC", time_zone: "Etc/UTC"}
-        convert(iso_datetime, calendar)
-      {:error, _} = error ->
-        error
-    end
-  end
-
-  @doc """
-  Converts the given Unix time to `DateTime`.
-
-  The integer can be given in different unit
-  according to `System.convert_time_unit/3` and it will
-  be converted to microseconds internally.
-
-  Unix times are always in UTC and therefore the DateTime
-  will be returned in UTC.
-
-  ## Examples
-
-      # An easy way to get the Unix epoch is passing 0 to this function
-      iex> DateTime.from_unix!(0)
-      #DateTime<1970-01-01 00:00:00Z>
-
-      iex> DateTime.from_unix!(1464096368)
-      #DateTime<2016-05-24 13:26:08Z>
-
-      iex> DateTime.from_unix!(1432560368868569, :microsecond)
-      #DateTime<2015-05-25 13:26:08.868569Z>
-
-  """
-  @spec from_unix!(integer, :native | System.time_unit, Calendar.calendar) :: t
-  def from_unix!(integer, unit \\ :second, calendar \\ Calendar.ISO) when is_atom(unit) do
-    case from_unix(integer, unit, calendar) do
-      {:ok, datetime} ->
-        datetime
-      {:error, :invalid_unix_time} ->
-        raise ArgumentError, "invalid Unix time #{integer}"
-    end
-  end
-
-  @doc """
-  Converts the given `NaiveDateTime` to `DateTime`.
-
-  It expects a time zone to put the NaiveDateTime in.
-  Currently it only supports "Etc/UTC" as time zone.
-
-  ## Examples
-
-      iex> {:ok, datetime} = DateTime.from_naive(~N[2016-05-24 13:26:08.003], "Etc/UTC")
-      iex> datetime
-      #DateTime<2016-05-24 13:26:08.003Z>
-
-  """
-  @spec from_naive(NaiveDateTime.t, Calendar.time_zone) :: {:ok, t}
-  def from_naive(naive_datetime, time_zone)
-
-  def from_naive(%NaiveDateTime{calendar: calendar,
-                                hour: hour, minute: minute, second: second, microsecond: microsecond,
-                                year: year, month: month, day: day}, "Etc/UTC") do
-    {:ok, %DateTime{calendar: calendar, year: year, month: month, day: day,
-                    hour: hour, minute: minute, second: second, microsecond: microsecond,
-                    std_offset: 0, utc_offset: 0, zone_abbr: "UTC", time_zone: "Etc/UTC"}}
-  end
-
-  @doc """
-  Converts the given `NaiveDateTime` to `DateTime`.
-
-  It expects a time zone to put the NaiveDateTime in.
-  Currently it only supports "Etc/UTC" as time zone.
-
-  ## Examples
-
-      iex> DateTime.from_naive!(~N[2016-05-24 13:26:08.003], "Etc/UTC")
-      #DateTime<2016-05-24 13:26:08.003Z>
-
-  """
-  @spec from_naive!(NaiveDateTime.t, Calendar.time_zone) :: t
-  def from_naive!(naive_datetime, time_zone) do
-    case from_naive(naive_datetime, time_zone) do
-      {:ok, datetime} ->
-        datetime
-      {:error, reason} ->
-        raise ArgumentError, "cannot parse #{inspect naive_datetime} to datetime, reason: #{inspect reason}"
-    end
-  end
-
-  @doc """
-  Converts the given `datetime` to Unix time.
-
-  The `datetime` is expected to be using the ISO calendar
-  with a year greater than or equal to 0.
-
-  It will return the integer with the given unit,
-  according to `System.convert_time_unit/3`.
-
-  ## Examples
-
-      iex> 1464096368 |> DateTime.from_unix!() |> DateTime.to_unix()
-      1464096368
-
-      iex> dt = %DateTime{calendar: Calendar.ISO, day: 20, hour: 18, microsecond: {273806, 6},
-      ...>                minute: 58, month: 11, second: 19, time_zone: "America/Montevideo",
-      ...>                utc_offset: -10800, std_offset: 3600, year: 2014, zone_abbr: "UYST"}
-      iex> DateTime.to_unix(dt)
-      1416517099
-
-      iex> flamel = %DateTime{calendar: Calendar.ISO, day: 22, hour: 8, microsecond: {527771, 6},
-      ...>                minute: 2, month: 3, second: 25, std_offset: 0, time_zone: "Etc/UTC",
-      ...>                utc_offset: 0, year: 1418, zone_abbr: "UTC"}
-      iex> DateTime.to_unix(flamel)
-      -17412508655
-
-  """
-  @spec to_unix(Calendar.datetime, System.time_unit) :: integer
-  def to_unix(datetime, unit \\ :second)
-
-  def to_unix(%{utc_offset: utc_offset, std_offset: std_offset} = datetime, unit) do
-    {days, fraction} = to_iso_days(datetime)
-    unix_units = Calendar.ISO.iso_days_to_unit({days - @unix_days, fraction}, unit)
-    offset_units = System.convert_time_unit(utc_offset + std_offset, :second, unit)
-    unix_units - offset_units
-  end
-
-  @doc """
-  Converts the given `datetime` into a `NaiveDateTime`.
-
-  Because `NaiveDateTime` does not hold time zone information,
-  any time zone related data will be lost during the conversion.
-
-  ## Examples
-
-      iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "CET",
-      ...>                hour: 23, minute: 0, second: 7, microsecond: {0, 1},
-      ...>                utc_offset: 3600, std_offset: 0, time_zone: "Europe/Warsaw"}
-      iex> DateTime.to_naive(dt)
-      ~N[2000-02-29 23:00:07.0]
-
-  """
-  @spec to_naive(t) :: NaiveDateTime.t
-  def to_naive(%DateTime{calendar: calendar, year: year, month: month, day: day,
-                         hour: hour, minute: minute, second: second, microsecond: microsecond}) do
-    %NaiveDateTime{year: year, month: month, day: day, calendar: calendar,
-                   hour: hour, minute: minute, second: second, microsecond: microsecond}
-  end
-
-  @doc """
-  Converts a `DateTime` into a `Date`.
-
-  Because `Date` does not hold time nor time zone information,
-  data will be lost during the conversion.
-
-  ## Examples
-
-      iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "CET",
-      ...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
-      ...>                utc_offset: 3600, std_offset: 0, time_zone: "Europe/Warsaw"}
-      iex> DateTime.to_date(dt)
-      ~D[2000-02-29]
-
-  """
-  @spec to_date(t) :: Date.t
-  def to_date(%DateTime{year: year, month: month, day: day, calendar: calendar}) do
-    %Date{year: year, month: month, day: day, calendar: calendar}
-  end
-
-  @doc """
-  Converts a `DateTime` into `Time`.
-
-  Because `Time` does not hold date nor time zone information,
-  data will be lost during the conversion.
-
-  ## Examples
-
-      iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "CET",
-      ...>                hour: 23, minute: 0, second: 7, microsecond: {0, 1},
-      ...>                utc_offset: 3600, std_offset: 0, time_zone: "Europe/Warsaw"}
-      iex> DateTime.to_time(dt)
-      ~T[23:00:07.0]
-
-  """
-  @spec to_time(t) :: Time.t
-  def to_time(%DateTime{hour: hour, minute: minute, second: second, microsecond: microsecond, calendar: calendar}) do
-    %Time{hour: hour, minute: minute, second: second, microsecond: microsecond, calendar: calendar}
-  end
-
-  @doc """
-  Converts the given datetime to
-  [ISO 8601:2004](https://en.wikipedia.org/wiki/ISO_8601) format.
-
-  By default, `DateTime.to_iso8601/2` returns datetimes formatted in the "extended"
-  format, for human readability. It also supports the "basic" format through passing the `:basic` option.
-
-  Only supports converting datetimes which are in the ISO calendar,
-  attempting to convert datetimes from other calendars will raise.
-
-  WARNING: the ISO 8601 datetime format does not contain the time zone nor
-  its abbreviation, which means information is lost when converting to such
-  format.
-
-  ### Examples
-
-      iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "CET",
-      ...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
-      ...>                utc_offset: 3600, std_offset: 0, time_zone: "Europe/Warsaw"}
-      iex> DateTime.to_iso8601(dt)
-      "2000-02-29T23:00:07+01:00"
-
-      iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "UTC",
-      ...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
-      ...>                utc_offset: 0, std_offset: 0, time_zone: "Etc/UTC"}
-      iex> DateTime.to_iso8601(dt)
-      "2000-02-29T23:00:07Z"
-
-      iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "AMT",
-      ...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
-      ...>                utc_offset: -14400, std_offset: 0, time_zone: "America/Manaus"}
-      iex> DateTime.to_iso8601(dt, :extended)
-      "2000-02-29T23:00:07-04:00"
-
-      iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "AMT",
-      ...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
-      ...>                utc_offset: -14400, std_offset: 0, time_zone: "America/Manaus"}
-      iex> DateTime.to_iso8601(dt, :basic)
-      "20000229T230007-0400"
-
-  """
-  @spec to_iso8601(Calendar.datetime, :extended | :basic ) :: String.t
-  def to_iso8601(datetime, format \\ :extended)
-
-  def to_iso8601(%{calendar: Calendar.ISO, year: year, month: month, day: day,
-                  hour: hour, minute: minute, second: second, microsecond: microsecond,
-                  time_zone: time_zone, zone_abbr: zone_abbr, utc_offset: utc_offset, std_offset: std_offset}, format) when format in [:extended, :basic] do
-    Calendar.ISO.datetime_to_iso8601(year, month, day, hour, minute, second, microsecond,
-                                     time_zone, zone_abbr, utc_offset, std_offset, format)
-  end
-
-  def to_iso8601(%{calendar: _, year: _, month: _, day: _,
-                   hour: _, minute: _, second: _, microsecond: _,
-                   time_zone: _, zone_abbr: _, utc_offset: _, std_offset: _} = datetime, format) when format in [:extended, :basic] do
-    datetime
-    |> convert!(Calendar.ISO)
-    |> to_iso8601(format)
-  end
-
-  def to_iso8601(_, format) do
-    raise ArgumentError, "DateTime.to_iso8601/2 expects format to be :extended or :basic, got: #{inspect format}"
-  end
-
-  @doc """
-  Parses the extended "Date and time of day" format described by
-  [ISO 8601:2004](https://en.wikipedia.org/wiki/ISO_8601).
-
-  Since ISO8601 does not include the proper time zone, the given
-  string will be converted to UTC and its offset in seconds will be
-  returned as part of this function. Therefore offset information
-  must be present in the string.
-
-  As specified in the standard, the separator "T" may be omitted if
-  desired as there is no ambiguity within this function.
-
-  Time representations with reduced accuracy are not supported.
-
-  Note that while ISO8601 allows datetimes to specify 24:00:00 as the
-  zero hour of the next day, this notation is not supported by Elixir.
-
-  ## Examples
-
-      iex> {:ok, datetime, 0} = DateTime.from_iso8601("2015-01-23T23:50:07Z")
-      iex> datetime
-      #DateTime<2015-01-23 23:50:07Z>
-
-      iex> {:ok, datetime, 9000} = DateTime.from_iso8601("2015-01-23T23:50:07.123+02:30")
-      iex> datetime
-      #DateTime<2015-01-23 21:20:07.123Z>
-
-      iex> {:ok, datetime, 9000} = DateTime.from_iso8601("2015-01-23T23:50:07,123+02:30")
-      iex> datetime
-      #DateTime<2015-01-23 21:20:07.123Z>
-
-      iex> DateTime.from_iso8601("2015-01-23P23:50:07")
-      {:error, :invalid_format}
-      iex> DateTime.from_iso8601("2015-01-23 23:50:07A")
-      {:error, :invalid_format}
-      iex> DateTime.from_iso8601("2015-01-23T23:50:07")
-      {:error, :missing_offset}
-      iex> DateTime.from_iso8601("2015-01-23 23:50:61")
-      {:error, :invalid_time}
-      iex> DateTime.from_iso8601("2015-01-32 23:50:07")
-      {:error, :invalid_date}
-
-      iex> DateTime.from_iso8601("2015-01-23T23:50:07.123-00:00")
-      {:error, :invalid_format}
-      iex> DateTime.from_iso8601("2015-01-23T23:50:07.123-00:60")
-      {:error, :invalid_format}
-
-  """
-  @spec from_iso8601(String.t, Calendar.calendar) :: {:ok, t, Calendar.utc_offset} | {:error, atom}
-  def from_iso8601(string, calendar \\ Calendar.ISO)
-
-  def from_iso8601(<<year::4-bytes, ?-, month::2-bytes, ?-, day::2-bytes, sep,
-                     hour::2-bytes, ?:, min::2-bytes, ?:, sec::2-bytes, rest::binary>>, calendar) when sep in [?\s, ?T] do
-    with {year, ""} <- Integer.parse(year),
-         {month, ""} <- Integer.parse(month),
-         {day, ""} <- Integer.parse(day),
-         {hour, ""} <- Integer.parse(hour),
-         {minute, ""} <- Integer.parse(min),
-         {second, ""} <- Integer.parse(sec),
-         {microsecond, rest} <- Calendar.ISO.parse_microsecond(rest),
-         {:ok, date} <- Date.new(year, month, day),
-         {:ok, time} <- Time.new(hour, minute, second, microsecond),
-         {:ok, offset} <- parse_offset(rest) do
-      %{year: year, month: month, day: day} = date
-      %{hour: hour, minute: minute, second: second, microsecond: microsecond} = time
-      {_, precision} = microsecond
-
-      datetime =
-        Calendar.ISO.naive_datetime_to_iso_days(year, month, day, hour, minute, second, microsecond)
-        |> apply_tz_offset(offset)
-        |> from_iso_days("Etc/UTC", "UTC", 0, 0, calendar, precision)
-
-      {:ok, %{datetime | microsecond: microsecond}, offset}
-    else
-      {:error, reason} -> {:error, reason}
-      _ -> {:error, :invalid_format}
-    end
-  end
-
-  def from_iso8601(_, _) do
-    {:error, :invalid_format}
-  end
-
-  defp parse_offset(rest) do
-    case Calendar.ISO.parse_offset(rest) do
-      {offset, ""} when is_integer(offset) -> {:ok, offset}
-      {nil, ""} -> {:error, :missing_offset}
-      _ -> {:error, :invalid_format}
-    end
-  end
-
-  @doc """
-  Converts the given `datetime` to a string according to its calendar.
-
-  ### Examples
-
-      iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "CET",
-      ...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
-      ...>                utc_offset: 3600, std_offset: 0, time_zone: "Europe/Warsaw"}
-      iex> DateTime.to_string(dt)
-      "2000-02-29 23:00:07+01:00 CET Europe/Warsaw"
-
-      iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "UTC",
-      ...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
-      ...>                utc_offset: 0, std_offset: 0, time_zone: "Etc/UTC"}
-      iex> DateTime.to_string(dt)
-      "2000-02-29 23:00:07Z"
-
-      iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "AMT",
-      ...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
-      ...>                utc_offset: -14400, std_offset: 0, time_zone: "America/Manaus"}
-      iex> DateTime.to_string(dt)
-      "2000-02-29 23:00:07-04:00 AMT America/Manaus"
-
-  """
-  @spec to_string(Calendar.datetime) :: String.t
-  def to_string(datetime)
-
-  def to_string(%{calendar: calendar, year: year, month: month, day: day,
-                  hour: hour, minute: minute, second: second, microsecond: microsecond,
-                  time_zone: time_zone, zone_abbr: zone_abbr, utc_offset: utc_offset, std_offset: std_offset}) do
-    calendar.datetime_to_string(year, month, day, hour, minute, second, microsecond,
-                                time_zone, zone_abbr, utc_offset, std_offset)
-  end
-
-  defimpl String.Chars do
-    def to_string(%{calendar: calendar, year: year, month: month, day: day,
-                    hour: hour, minute: minute, second: second, microsecond: microsecond,
-                    time_zone: time_zone, zone_abbr: zone_abbr, utc_offset: utc_offset, std_offset: std_offset}) do
-      calendar.datetime_to_string(year, month, day, hour, minute, second, microsecond,
-                                  time_zone, zone_abbr, utc_offset, std_offset)
-    end
-  end
-
-  defimpl Inspect do
-    def inspect(%{calendar: Calendar.ISO, year: year, month: month, day: day,
-                  hour: hour, minute: minute, second: second, microsecond: microsecond,
-                  time_zone: time_zone, zone_abbr: zone_abbr, utc_offset: utc_offset, std_offset: std_offset}, _) do
-      "#DateTime<" <> Calendar.ISO.datetime_to_string(year, month, day, hour, minute, second, microsecond,
-                                                      time_zone, zone_abbr, utc_offset, std_offset) <> ">"
-    end
-
-    def inspect(datetime, opts) do
-      Inspect.Any.inspect(datetime, opts)
-    end
-  end
-
-  @doc """
-  Compares two datetime structs.
-
-  Returns `:gt` if first datetime is later than the second
-  and `:lt` for vice versa. If the two datetimes are equal
-  `:eq` is returned.
-
-  Note that both utc and stc offsets will be taken into
-  account when comparison is done.
-
-  ## Examples
-
-      iex> dt1 = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "AMT",
-      ...>                 hour: 23, minute: 0, second: 7, microsecond: {0, 0},
-      ...>                 utc_offset: -14400, std_offset: 0, time_zone: "America/Manaus"}
-      iex> dt2 = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "CET",
-      ...>                 hour: 23, minute: 0, second: 7, microsecond: {0, 0},
-      ...>                 utc_offset: 3600, std_offset: 0, time_zone: "Europe/Warsaw"}
-      iex> DateTime.compare(dt1, dt2)
-      :gt
-
-  """
-  @spec compare(Calendar.datetime, Calendar.datetime) :: :lt | :eq | :gt
-  def compare(%DateTime{utc_offset: utc_offset1, std_offset: std_offset1} = datetime1,
-              %DateTime{utc_offset: utc_offset2, std_offset: std_offset2} = datetime2) do
-    {days1, {parts1, ppd1}} =
-      datetime1
-      |> to_iso_days()
-      |> apply_tz_offset(utc_offset1 + std_offset1)
-
-    {days2, {parts2, ppd2}} =
-      datetime2
-      |> to_iso_days()
-      |> apply_tz_offset(utc_offset2 + std_offset2)
-
-    # Ensure fraction tuples have same denominator.
-    iso_days1 = {days1, parts1 * ppd2}
-    iso_days2 = {days2, parts2 * ppd1}
-
-    case {iso_days1, iso_days2}  do
-      {first, second} when first > second -> :gt
-      {first, second} when first < second -> :lt
-      _ -> :eq
-    end
-  end
-
-  @doc """
-  Subtracts `datetime2` from `datetime1`.
-
-  The answer can be returned in any `unit` available from `t:System.time_unit/0`.
-
-  This function returns the difference in seconds where seconds are measured
-  according to `Calendar.ISO`.
-
-  ## Examples
-
-      iex> dt1 = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "AMT",
-      ...>                 hour: 23, minute: 0, second: 7, microsecond: {0, 0},
-      ...>                 utc_offset: -14400, std_offset: 0, time_zone: "America/Manaus"}
-      iex> dt2 = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "CET",
-      ...>                 hour: 23, minute: 0, second: 7, microsecond: {0, 0},
-      ...>                 utc_offset: 3600, std_offset: 0, time_zone: "Europe/Warsaw"}
-      iex> DateTime.diff(dt1, dt2)
-      18000
-      iex> DateTime.diff(dt2, dt1)
-      -18000
-
-  """
-  @spec diff(Calendar.datetime, Calendar.datetime) :: integer()
-  def diff(%{utc_offset: utc_offset1, std_offset: std_offset1} = datetime1,
-           %{utc_offset: utc_offset2, std_offset: std_offset2} = datetime2, unit \\ :second) do
-    naive_diff =
-      (datetime1 |> to_iso_days() |> Calendar.ISO.iso_days_to_unit(unit)) -
-      (datetime2 |> to_iso_days() |> Calendar.ISO.iso_days_to_unit(unit))
-    offset_diff =
-      (utc_offset2 + std_offset2) - (utc_offset1 + std_offset1)
-    naive_diff + System.convert_time_unit(offset_diff, :second, unit)
-  end
-
-  @doc """
-  Converts a given `datetime` from one calendar to another.
-
-  If it is not possible to convert unambiguously between the calendars
-  (see `Calendar.compatible_calendars?/2`), an `{:error, :incompatible_calendars}` tuple
-  is returned.
-
-  ## Examples
-
-  Imagine someone implements `Calendar.Holocene`, a calendar based on the
-  Gregorian calendar that adds exactly 10,000 years to the current Gregorian
-  year:
-
-      iex> dt1 = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "AMT",
-      ...>                 hour: 23, minute: 0, second: 7, microsecond: {0, 0},
-      ...>                 utc_offset: -14400, std_offset: 0, time_zone: "America/Manaus"}
-      iex> DateTime.convert(dt1, Calendar.Holocene)
-      {:ok, %DateTime{calendar: Calendar.Holocene, day: 29, hour: 23,
-                      microsecond: {0, 0}, minute: 0, month: 2, second: 7, std_offset: 0,
-                      time_zone: "America/Manaus", utc_offset: -14400, year: 12000,
-                      zone_abbr: "AMT"}}
-
-  """
-  @spec convert(Calendar.datetime, Calendar.calendar) :: {:ok, t} | {:error, :incompatible_calendars}
-  def convert(%{calendar: calendar, year: year, month: month, day: day,
-                hour: hour, minute: minute, second: second, microsecond: microsecond,
-                time_zone: time_zone, zone_abbr: zone_abbr, utc_offset: utc_offset, std_offset: std_offset}, calendar) do
-    {:ok, %DateTime{calendar: calendar, year: year, month: month, day: day,
-                    hour: hour, minute: minute, second: second, microsecond: microsecond,
-                    time_zone: time_zone, zone_abbr: zone_abbr, utc_offset: utc_offset, std_offset: std_offset}}
-  end
-
-  def convert(%{calendar: dt_calendar, microsecond: {_, precision}} = datetime, calendar) do
-    if Calendar.compatible_calendars?(dt_calendar, calendar) do
-      result_datetime =
-        datetime
-        |> to_iso_days
-        |> from_iso_days(datetime, calendar, precision)
-      {:ok, result_datetime}
-    else
-      {:error, :incompatible_calendars}
-    end
-  end
-
-  @doc """
-  Converts a given `datetime` from one calendar to another.
-
-  If it is not possible to convert unambiguously between the calendars
-  (see `Calendar.compatible_calendars?/2`), an ArgumentError is raised.
-
-  ## Examples
-
-  Imagine someone implements `Calendar.Holocene`, a calendar based on the
-  Gregorian calendar that adds exactly 10,000 years to the current Gregorian
-  year:
-
-      iex> dt1 = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "AMT",
-      ...>                 hour: 23, minute: 0, second: 7, microsecond: {0, 0},
-      ...>                 utc_offset: -14400, std_offset: 0, time_zone: "America/Manaus"}
-      iex> DateTime.convert!(dt1, Calendar.Holocene)
-      %DateTime{calendar: Calendar.Holocene, day: 29, hour: 23,
-                microsecond: {0, 0}, minute: 0, month: 2, second: 7, std_offset: 0,
-                time_zone: "America/Manaus", utc_offset: -14400, year: 12000,
-                zone_abbr: "AMT"}
-
-  """
-  @spec convert!(Calendar.datetime, Calendar.calendar) :: t | no_return
-  def convert!(datetime, calendar) do
-    case convert(datetime, calendar) do
-      {:ok, value} ->
-        value
-      {:error, :incompatible_calendars} ->
-        raise ArgumentError, "cannot convert #{inspect datetime} to target calendar #{inspect calendar}, reason: #{inspect datetime.calendar} and #{inspect calendar} have different day rollover moments, making this conversion ambiguous"
-    end
-  end
-
-  defp to_iso_days(%{calendar: calendar,year: year, month: month, day: day,
-                     hour: hour, minute: minute, second: second, microsecond: microsecond}) do
-    calendar.naive_datetime_to_iso_days(year, month, day, hour, minute, second, microsecond)
-  end
-
-  defp from_iso_days(iso_days, datetime, calendar, precision) do
-    %{time_zone: time_zone, zone_abbr: zone_abbr, utc_offset: utc_offset, std_offset: std_offset} = datetime
-    from_iso_days(iso_days, time_zone, zone_abbr, utc_offset, std_offset, calendar, precision)
-  end
-
-  defp from_iso_days(iso_days, time_zone, zone_abbr, utc_offset, std_offset, calendar, precision) do
-    {year, month, day, hour, minute, second, {microsecond, _}} = calendar.naive_datetime_from_iso_days(iso_days)
-    %DateTime{calendar: calendar, year: year, month: month, day: day,
-              hour: hour, minute: minute, second: second, microsecond: {microsecond, precision},
-              time_zone: time_zone, zone_abbr: zone_abbr, utc_offset: utc_offset, std_offset: std_offset}
-  end
-
-  defp apply_tz_offset(iso_days, offset) do
-    Calendar.ISO.add_day_fraction_to_iso_days(iso_days, -offset, 86400)
-  end
-end

lib/elixir/lib/calendar/iso.ex

@@ -1,447 +0,0 @@
-defmodule Calendar.ISO do
-  @moduledoc """
-  A calendar implementation that follows to ISO8601.
-
-  This calendar implements the proleptic Gregorian calendar and
-  is therefore compatible with the calendar used in most countries
-  today. The proleptic means the Gregorian rules for leap years are
-  applied for all time, consequently the dates give different results
-  before the year 1583 from when the Gregorian calendar was adopted.
-
-  Note that while ISO8601 allows times and datetimes to specify
-  24:00:00 as the zero hour of the next day, this notation is not
-  supported by Elixir.
-  """
-
-  @behaviour Calendar
-
-  @unix_epoch 62167219200
-  @unix_start 1_000_000 * -@unix_epoch
-  @unix_end 1_000_000 * (315569519999 - @unix_epoch)
-  @unix_range_microseconds @unix_start..@unix_end
-
-  @type year :: 0..9999
-  @type month :: 1..12
-  @type day :: 1..31
-
-  @seconds_per_minute 60
-  @seconds_per_hour 60 * 60
-  @seconds_per_day 24 * 60 * 60 # Note that this does _not_ handle leap seconds.
-  @microseconds_per_second 1_000_000
-
-  @doc """
-  Returns the `t:Calendar.iso_days` format of the specified date.
-
-  ## Examples
-
-      iex> Calendar.ISO.naive_datetime_to_iso_days(0, 1, 1, 0, 0, 0, {0, 6})
-      {0, {0, 86400000000}}
-      iex> Calendar.ISO.naive_datetime_to_iso_days(2000, 1, 1, 12, 0, 0, {0, 6})
-      {730485, {43200000000, 86400000000}}
-      iex> Calendar.ISO.naive_datetime_to_iso_days(2000, 1, 1, 13, 0, 0, {0, 6})
-      {730485, {46800000000, 86400000000}}
-
-  """
-  @spec naive_datetime_to_iso_days(Calendar.year, Calendar.month, Calendar.day,
-                                   Calendar.hour, Calendar.minute, Calendar.second,
-                                   Calendar.microsecond) :: Calendar.iso_days
-  def naive_datetime_to_iso_days(year, month, day, hour, minute, second, microsecond) do
-    {date_to_iso_days_days(year, month, day),
-     time_to_day_fraction(hour, minute, second, microsecond)}
-  end
-
-  @doc """
-  Converts the `t:Calendar.iso_days` format to the datetime format specified by this calendar.
-
-  ## Examples
-
-      iex> Calendar.ISO.naive_datetime_from_iso_days({0, {0, 86400}})
-      {0, 1, 1, 0, 0, 0, {0, 6}}
-      iex> Calendar.ISO.naive_datetime_from_iso_days({730485, {0, 86400}})
-      {2000, 1, 1, 0, 0, 0, {0, 6}}
-      iex> Calendar.ISO.naive_datetime_from_iso_days({730485, {43200, 86400}})
-      {2000, 1, 1, 12, 0, 0, {0, 6}}
-
-  """
-  @spec naive_datetime_from_iso_days(Calendar.iso_days) ::
-        {Calendar.year, Calendar.month, Calendar.day,
-         Calendar.hour, Calendar.minute, Calendar.second, Calendar.microsecond}
-  def naive_datetime_from_iso_days({days, day_fraction}) do
-    {year, month, day} = date_from_iso_days_days(days)
-    {hour, minute, second, microsecond} = time_from_day_fraction(day_fraction)
-    {year, month, day, hour, minute, second, microsecond}
-  end
-
-  @doc """
-  Returns the normalized day fraction of the specified time.
-
-  ## Examples
-
-      iex> Calendar.ISO.time_to_day_fraction(0, 0, 0, {0, 6})
-      {0, 86400000000}
-      iex> Calendar.ISO.time_to_day_fraction(12, 34, 56, {123, 6})
-      {45296000123, 86400000000}
-
-  """
-  @spec time_to_day_fraction(Calendar.hour, Calendar.minute,
-                             Calendar.second, Calendar.microsecond) :: Calendar.day_fraction
-  def time_to_day_fraction(0, 0, 0, {0, _}) do
-    {0, 86400000000}
-  end
-  def time_to_day_fraction(hour, minute, second, {microsecond, _}) do
-    combined_seconds = hour * @seconds_per_hour + minute * @seconds_per_minute + second
-    {combined_seconds * @microseconds_per_second + microsecond, @seconds_per_day * @microseconds_per_second}
-  end
-
-  @doc """
-  Converts a day fraction to this Calendar's representation of time.
-
-  ## Examples
-
-      iex> Calendar.ISO.time_from_day_fraction({1,2})
-      {12, 0, 0, {0, 6}}
-      iex> Calendar.ISO.time_from_day_fraction({13,24})
-      {13, 0, 0, {0, 6}}
-
-  """
-  @spec time_from_day_fraction(Calendar.day_fraction) ::
-        {Calendar.hour, Calendar.minute, Calendar.second, Calendar.microsecond}
-  def time_from_day_fraction({parts_in_day, parts_per_day}) do
-    total_microseconds = div(parts_in_day * @seconds_per_day * @microseconds_per_second, parts_per_day)
-    {hours, rest_microseconds1} = div_mod(total_microseconds, @seconds_per_hour * @microseconds_per_second)
-    {minutes, rest_microseconds2} = div_mod(rest_microseconds1, @seconds_per_minute * @microseconds_per_second)
-    {seconds, microseconds} = div_mod(rest_microseconds2, @microseconds_per_second)
-    {hours, minutes, seconds, {microseconds, 6}}
-  end
-
-  # Converts year, month, day to count of days since 0000-01-01.
-  @doc false
-  def date_to_iso_days_days(0, 1, 1) do
-    0
-  end
-  def date_to_iso_days_days(1970, 1, 1) do
-    719528
-  end
-  def date_to_iso_days_days(year, month, day) do
-    :calendar.date_to_gregorian_days(year, month, day)
-  end
-
-  # Converts count of days since 0000-01-01 to {year, month, day} tuple.
-  @doc false
-  def date_from_iso_days_days(days) do
-    :calendar.gregorian_days_to_date(days)
-  end
-
-  defp div_mod(int1, int2) do
-    div = div(int1, int2)
-    mod = int1 - (div * int2)
-    {div, mod}
-  end
-
-  @doc """
-  Returns how many days there are in the given year-month.
-
-  ## Examples
-
-      iex> Calendar.ISO.days_in_month(1900, 1)
-      31
-      iex> Calendar.ISO.days_in_month(1900, 2)
-      28
-      iex> Calendar.ISO.days_in_month(2000, 2)
-      29
-      iex> Calendar.ISO.days_in_month(2001, 2)
-      28
-      iex> Calendar.ISO.days_in_month(2004, 2)
-      29
-      iex> Calendar.ISO.days_in_month(2004, 4)
-      30
-
-  """
-  @spec days_in_month(year, month) :: 28..31
-  def days_in_month(year, month)
-
-  def days_in_month(year, 2) do
-    if leap_year?(year), do: 29, else: 28
-  end
-  def days_in_month(_, month) when month in [4, 6, 9, 11], do: 30
-  def days_in_month(_, month) when month in 1..12, do: 31
-
-  @doc """
-  Returns if the given year is a leap year.
-
-  ## Examples
-
-      iex> Calendar.ISO.leap_year?(2000)
-      true
-      iex> Calendar.ISO.leap_year?(2001)
-      false
-      iex> Calendar.ISO.leap_year?(2004)
-      true
-      iex> Calendar.ISO.leap_year?(1900)
-      false
-
-  """
-  @spec leap_year?(year) :: boolean()
-  def leap_year?(year) when is_integer(year) and year >= 0 do
-    rem(year, 4) === 0 and (rem(year, 100) > 0 or rem(year, 400) === 0)
-  end
-
-  @doc """
-  Calculates the day of the week from the given `year`, `month`, and `day`.
-
-  It is an integer from 1 to 7, where 1 is Monday and 7 is Sunday.
-
-  ## Examples
-
-      iex> Calendar.ISO.day_of_week(2016, 10, 31)
-      1
-      iex> Calendar.ISO.day_of_week(2016, 11, 01)
-      2
-      iex> Calendar.ISO.day_of_week(2016, 11, 02)
-      3
-      iex> Calendar.ISO.day_of_week(2016, 11, 03)
-      4
-      iex> Calendar.ISO.day_of_week(2016, 11, 04)
-      5
-      iex> Calendar.ISO.day_of_week(2016, 11, 05)
-      6
-      iex> Calendar.ISO.day_of_week(2016, 11, 06)
-      7
-  """
-  @spec day_of_week(year, month, day) :: 1..7
-  def day_of_week(year, month, day)
-      when is_integer(year) and is_integer(month) and is_integer(day) do
-    :calendar.day_of_the_week(year, month, day)
-  end
-
-  @doc """
-  Converts the given time into a string.
-  """
-  def time_to_string(hour, minute, second, microsecond, format \\ :extended)
-
-  def time_to_string(hour, minute, second, {_, 0}, format) do
-    time_to_string_format(hour, minute, second, format)
-  end
-
-  def time_to_string(hour, minute, second, {microsecond, precision}, format) do
-    time_to_string_format(hour, minute, second, format) <>
-      "." <> (microsecond |> zero_pad(6) |> binary_part(0, precision))
-  end
-
-  defp time_to_string_format(hour, minute, second, :extended) do
-    zero_pad(hour, 2) <> ":" <> zero_pad(minute, 2) <> ":" <> zero_pad(second, 2)
-  end
-
-  defp time_to_string_format(hour, minute, second, :basic) do
-    zero_pad(hour, 2) <> zero_pad(minute, 2) <> zero_pad(second, 2)
-  end
-
-  @doc """
-  Converts the given date into a string.
-  """
-  def date_to_string(year, month, day) do
-    zero_pad(year, 4) <> "-" <> zero_pad(month, 2) <> "-" <> zero_pad(day, 2)
-  end
-
-  defp date_to_string(year, month, day, :extended), do: date_to_string(year, month, day)
-  defp date_to_string(year, month, day, :basic) do
-    zero_pad(year, 4) <> zero_pad(month, 2) <> zero_pad(day, 2)
-  end
-
-  @doc """
-  Converts the datetime (without time zone) into a string.
-  """
-  def naive_datetime_to_string(year, month, day, hour, minute, second, microsecond) do
-    date_to_string(year, month, day) <> " " <> time_to_string(hour, minute, second, microsecond)
-  end
-
-  @doc """
-  Convers the datetime (with time zone) into a string.
-  """
-  def datetime_to_string(year, month, day, hour, minute, second, microsecond,
-                         time_zone, zone_abbr, utc_offset, std_offset) do
-    date_to_string(year, month, day) <> " " <>
-      time_to_string(hour, minute, second, microsecond) <>
-      offset_to_string(utc_offset, std_offset, time_zone) <>
-      zone_to_string(utc_offset, std_offset, zone_abbr, time_zone)
-  end
-
-  def valid_date?(year, month, day) do
-    year <= 9999 and :calendar.valid_date(year, month, day)
-  end
-
-  def valid_time?(hour, minute, second, {microsecond, precision}) do
-    hour in 0..23 and minute in 0..59 and second in 0..60 and
-      microsecond in 0..999_999 and precision in 0..6
-  end
-
-  def day_rollover_relative_to_midnight_utc() do
-    {0, 1}
-  end
-
-  defp offset_to_string(utc, std, zone, format \\ :extended)
-  defp offset_to_string(0, 0, "Etc/UTC", _format), do: "Z"
-  defp offset_to_string(utc, std, _zone, format) do
-    total = utc + std
-    second = abs(total)
-    minute = second |> rem(3600) |> div(60)
-    hour = div(second, 3600)
-    format_offset(total, hour, minute, format)
-  end
-
-  defp format_offset(total, hour, minute, :extended) do
-    sign(total) <> zero_pad(hour, 2) <> ":" <> zero_pad(minute, 2)
-  end
-
-  defp format_offset(total, hour, minute, :basic) do
-    sign(total) <> zero_pad(hour, 2) <> zero_pad(minute, 2)
-  end
-
-  defp zone_to_string(0, 0, _abbr, "Etc/UTC"), do: ""
-  defp zone_to_string(_, _, abbr, zone), do: " " <> abbr <> " " <> zone
-
-  defp sign(total) when total < 0, do: "-"
-  defp sign(_), do: "+"
-
-  defp zero_pad(val, count) do
-    num = Integer.to_string(val)
-    :binary.copy("0", count - byte_size(num)) <> num
-  end
-
-  ## Helpers
-
-  @doc false
-  def from_unix(integer, unit) when is_integer(integer) do
-    total = System.convert_time_unit(integer, unit, :microsecond)
-    if total in @unix_range_microseconds do
-      microsecond = rem(total, 1_000_000)
-      precision = precision_for_unit(unit)
-      {date, time} = :calendar.gregorian_seconds_to_datetime(@unix_epoch + div(total, 1_000_000))
-      {:ok, date, time, {microsecond, precision}}
-    else
-      {:error, :invalid_unix_time}
-    end
-  end
-
-  defp precision_for_unit(unit) do
-    subsecond = div System.convert_time_unit(1, :second, unit), 10
-    precision_for_unit(subsecond, 0)
-  end
-
-  defp precision_for_unit(0, precision),
-    do: precision
-  defp precision_for_unit(_, 6),
-    do: 6
-  defp precision_for_unit(number, precision),
-    do: precision_for_unit(div(number, 10), precision + 1)
-
-  @doc false
-  def date_to_iso8601(year, month, day, format \\ :extended) do
-    date_to_string(year, month, day, format)
-  end
-
-  @doc false
-  def time_to_iso8601(hour, minute, second, microsecond, format \\ :extended) do
-    time_to_string(hour, minute, second, microsecond, format)
-  end
-
-  @doc false
-  def naive_datetime_to_iso8601(year, month, day, hour, minute, second, microsecond, format \\ :extended) do
-    date_to_string(year, month, day, format) <> "T" <> time_to_string(hour, minute, second, microsecond, format)
-  end
-
-  @doc false
-  def datetime_to_iso8601(year, month, day, hour, minute, second, microsecond,
-                          time_zone, _zone_abbr, utc_offset, std_offset, format \\ :extended) do
-    date_to_string(year, month, day, format) <> "T" <>
-      time_to_string(hour, minute, second, microsecond, format) <>
-      offset_to_string(utc_offset, std_offset, time_zone, format)
-  end
-
-  @doc false
-  def parse_microsecond("." <> rest) do
-    case parse_microsecond(rest, 0, "") do
-      {"", 0, _} ->
-        :error
-      {microsecond, precision, rest} when precision in 1..6 ->
-        pad = String.duplicate("0", 6 - byte_size(microsecond))
-        {{String.to_integer(microsecond <> pad), precision}, rest}
-      {microsecond, _precision, rest} ->
-        {{String.to_integer(binary_part(microsecond, 0, 6)), 6}, rest}
-    end
-  end
-
-  def parse_microsecond("," <> rest) do
-    parse_microsecond("." <> rest)
-  end
-
-  def parse_microsecond(rest) do
-    {{0, 0}, rest}
-  end
-
-  defp parse_microsecond(<<head, tail::binary>>, precision, acc) when head in ?0..?9,
-    do: parse_microsecond(tail, precision + 1, <<acc::binary, head>>)
-  defp parse_microsecond(rest, precision, acc),
-    do: {acc, precision, rest}
-
-  @doc false
-  def parse_offset(""),
-    do: {nil, ""}
-  def parse_offset("Z"),
-    do: {0, ""}
-  def parse_offset("-00:00"),
-    do: :error
-  def parse_offset(<<?+, hour::2-bytes, ?:, min::2-bytes, rest::binary>>),
-    do: parse_offset(1, hour, min, rest)
-  def parse_offset(<<?-, hour::2-bytes, ?:, min::2-bytes, rest::binary>>),
-    do: parse_offset(-1, hour, min, rest)
-  def parse_offset(<<?+, hour::2-bytes, min::2-bytes, rest::binary>>),
-    do: parse_offset(1, hour, min, rest)
-  def parse_offset(<<?-, hour::2-bytes, min::2-bytes, rest::binary>>),
-    do: parse_offset(-1, hour, min, rest)
-  def parse_offset(<<?+, hour::2-bytes, rest::binary>>),
-    do: parse_offset(1, hour, "00", rest)
-  def parse_offset(<<?-, hour::2-bytes, rest::binary>>),
-    do: parse_offset(-1, hour, "00", rest)
-  def parse_offset(_),
-    do: :error
-
-  defp parse_offset(sign, hour, min, rest) do
-    with {hour, ""} when hour < 24 <- Integer.parse(hour),
-         {min, ""} when min < 60 <- Integer.parse(min) do
-      {((hour * 60) + min) * 60 * sign, rest}
-    else
-      _ -> :error
-    end
-  end
-
-  @doc false
-  def iso_days_to_unit({days, {parts, ppd}}, unit) do
-    day_microseconds = days * @seconds_per_day * @microseconds_per_second
-    microseconds = div(parts * @seconds_per_day * @microseconds_per_second, ppd)
-    System.convert_time_unit(day_microseconds + microseconds, :microsecond, unit)
-  end
-
-  @doc false
-  def add_day_fraction_to_iso_days({days, {parts, ppd}}, add, ppd) do
-    normalize_iso_days(days, parts + add, ppd)
-  end
-  def add_day_fraction_to_iso_days({days, {parts, ppd}}, add, add_ppd) do
-    parts = parts * add_ppd
-    add = add * ppd
-    gcd = Integer.gcd(ppd, add_ppd)
-    result_parts = div(parts + add, gcd)
-    result_ppd = div(ppd * add_ppd, gcd)
-    normalize_iso_days(days, result_parts, result_ppd)
-  end
-
-  defp normalize_iso_days(days, parts, ppd) do
-    days_offset = div(parts, ppd)
-    parts = rem(parts, ppd)
-    if parts < 0 do
-      {days + days_offset - 1, {parts + ppd, ppd}}
-    else
-      {days + days_offset, {parts, ppd}}
-    end
-  end
-end

lib/elixir/lib/calendar/naive_datetime.ex

@@ -1,695 +0,0 @@
-defmodule NaiveDateTime do
-  @moduledoc """
-  A NaiveDateTime struct (without a time zone) and functions.
-
-  The NaiveDateTime struct contains the fields year, month, day, hour,
-  minute, second, microsecond and calendar. New naive datetimes can be
-  built with the `new/2` and `new/7` functions or using the `~N` sigil:
-
-      iex> ~N[2000-01-01 23:00:07]
-      ~N[2000-01-01 23:00:07]
-
-  The date and time fields in the struct can be accessed directly:
-
-      iex> naive = ~N[2000-01-01 23:00:07]
-      iex> naive.year
-      2000
-      iex> naive.second
-      7
-
-  We call them "naive" because this datetime representation does not
-  have a time zone. This means the datetime may not actually exist in
-  certain areas in the world even though it is valid.
-
-  For example, when daylight saving changes are applied by a region,
-  the clock typically moves forward or backward by one hour. This means
-  certain datetimes never occur or may occur more than once. Since
-  `NaiveDateTime` is not validated against a time zone, such errors
-  would go unnoticed.
-
-  The functions on this module work with the `NaiveDateTime` struct as well
-  as any struct that contains the same fields as the `NaiveDateTime` struct,
-  such as `DateTime`. Such functions expect
-  `t:Calendar.naive_datetime/0` in their typespecs (instead of `t:t/0`).
-
-  Developers should avoid creating the NaiveDateTime structs directly
-  and instead rely on the functions provided by this module as well
-  as the ones in 3rd party calendar libraries.
-
-  ## Comparing naive date times
-
-  Comparisons in Elixir using `==`, `>`, `<` and similar are structural
-  and based on the `NaiveDateTime` struct fields. For proper comparison
-  between naive datetimes, use the `compare/2` function.
-
-  ## Using epochs
-
-  The `add/3` and `diff/3` functions can be used for computing with
-  date times or retrieving the amount of seconds betweens instants.
-  For example, if there is an interest in computing the amount of
-  seconds from the Unix epoch (1970-01-01 00:00:00):
-
-      iex> NaiveDateTime.diff(~N[2010-04-17 14:00:00], ~N[1970-01-01 00:00:00])
-      1271512800
-
-      iex> NaiveDateTime.add(~N[1970-01-01 00:00:00], 1271512800)
-      ~N[2010-04-17 14:00:00]
-
-  Those functions are optimized to deal with common epochs, such
-  as the Unix Epoch above or the Gregorian Epoch (0000-01-01 00:00:00).
-  """
-
-  @enforce_keys [:year, :month, :day, :hour, :minute, :second]
-  defstruct [:year, :month, :day, :hour, :minute, :second, microsecond: {0, 0}, calendar: Calendar.ISO]
-
-  @type t :: %NaiveDateTime{year: Calendar.year, month: Calendar.month, day: Calendar.day,
-                            calendar: Calendar.calendar, hour: Calendar.hour, minute: Calendar.minute,
-                            second: Calendar.second, microsecond: Calendar.microsecond}
-
-  @doc """
-  Returns the current naive datetime in UTC.
-
-  Prefer using `DateTime.utc_now/0` when possible as, opposite
-  to `NaiveDateTime`, it will keep the time zone information.
-
-  ## Examples
-
-      iex> naive_datetime = NaiveDateTime.utc_now()
-      iex> naive_datetime.year >= 2016
-      true
-
-  """
-  @spec utc_now(Calendar.calendar) :: t
-  def utc_now(calendar \\ Calendar.ISO)
-
-  def utc_now(Calendar.ISO) do
-    {:ok, {year, month, day}, {hour, minute, second}, microsecond} =
-      Calendar.ISO.from_unix(:os.system_time, :native)
-    %NaiveDateTime{year: year, month: month, day: day,
-                   hour: hour, minute: minute, second: second,
-                   microsecond: microsecond, calendar: Calendar.ISO}
-  end
-
-  def utc_now(calendar) do
-    calendar
-    |> DateTime.utc_now
-    |> DateTime.to_naive
-  end
-
-  @doc """
-  Builds a new ISO naive datetime.
-
-  Expects all values to be integers. Returns `{:ok, naive_datetime}`
-  if each entry fits its appropriate range, returns `{:error, reason}`
-  otherwise.
-
-  ## Examples
-
-      iex> NaiveDateTime.new(2000, 1, 1, 0, 0, 0)
-      {:ok, ~N[2000-01-01 00:00:00]}
-      iex> NaiveDateTime.new(2000, 13, 1, 0, 0, 0)
-      {:error, :invalid_date}
-      iex> NaiveDateTime.new(2000, 2, 29, 0, 0, 0)
-      {:ok, ~N[2000-02-29 00:00:00]}
-      iex> NaiveDateTime.new(2000, 2, 30, 0, 0, 0)
-      {:error, :invalid_date}
-      iex> NaiveDateTime.new(2001, 2, 29, 0, 0, 0)
-      {:error, :invalid_date}
-
-      iex> NaiveDateTime.new(2000, 1, 1, 23, 59, 59, {0, 1})
-      {:ok, ~N[2000-01-01 23:59:59.0]}
-      iex> NaiveDateTime.new(2000, 1, 1, 23, 59, 59, 999_999)
-      {:ok, ~N[2000-01-01 23:59:59.999999]}
-      iex> NaiveDateTime.new(2000, 1, 1, 23, 59, 60, 999_999)
-      {:ok, ~N[2000-01-01 23:59:60.999999]}
-      iex> NaiveDateTime.new(2000, 1, 1, 24, 59, 59, 999_999)
-      {:error, :invalid_time}
-      iex> NaiveDateTime.new(2000, 1, 1, 23, 60, 59, 999_999)
-      {:error, :invalid_time}
-      iex> NaiveDateTime.new(2000, 1, 1, 23, 59, 61, 999_999)
-      {:error, :invalid_time}
-      iex> NaiveDateTime.new(2000, 1, 1, 23, 59, 59, 1_000_000)
-      {:error, :invalid_time}
-
-  """
-  @spec new(Calendar.year, Calendar.month, Calendar.day,
-            Calendar.hour, Calendar.minute, Calendar.second, Calendar.microsecond, Calendar.calendar) ::
-        {:ok, t} | {:error, atom}
-  def new(year, month, day, hour, minute, second, microsecond \\ {0, 0}, calendar \\ Calendar.ISO) do
-    with {:ok, date} <- Date.new(year, month, day, calendar),
-         {:ok, time} <- Time.new(hour, minute, second, microsecond, calendar),
-         do: new(date, time)
-  end
-
-  @doc """
-  Builds a naive datetime from date and time structs.
-
-  ## Examples
-
-      iex> NaiveDateTime.new(~D[2010-01-13], ~T[23:00:07.005])
-      {:ok, ~N[2010-01-13 23:00:07.005]}
-
-  """
-  @spec new(Date.t, Time.t) :: {:ok, t}
-  def new(date, time)
-
-  def new(%Date{calendar: calendar, year: year, month: month, day: day},
-          %Time{calendar: calendar, hour: hour, minute: minute, second: second, microsecond: microsecond}) do
-    {:ok, %NaiveDateTime{calendar: calendar, year: year, month: month, day: day,
-                         hour: hour, minute: minute, second: second, microsecond: microsecond}}
-  end
-
-  @doc """
-  Adds a specified amount of time to a `NaiveDateTime`.
-
-  Accepts an `integer` in any `unit` available from `t:System.time_unit/0`.
-  Negative values will be move backwards in time.
-
-  This operation is only possible if both calendars are convertible to `Calendar.ISO`.
-
-  ## Examples
-
-      # adds seconds by default
-      iex> NaiveDateTime.add(~N[2014-10-02 00:29:10], 2)
-      ~N[2014-10-02 00:29:12]
-
-      # accepts negative offsets
-      iex> NaiveDateTime.add(~N[2014-10-02 00:29:10], -2)
-      ~N[2014-10-02 00:29:08]
-
-      # can work with other units
-      iex> NaiveDateTime.add(~N[2014-10-02 00:29:10], 2_000, :millisecond)
-      ~N[2014-10-02 00:29:12]
-
-      # keeps the same precision
-      iex> NaiveDateTime.add(~N[2014-10-02 00:29:10.021], 21, :second)
-      ~N[2014-10-02 00:29:31.021]
-
-      # changes below the precision will not be visible
-      iex> hidden = NaiveDateTime.add(~N[2014-10-02 00:29:10], 21, :millisecond)
-      iex> hidden.microsecond  # ~N[2014-10-02 00:29:10]
-      {21000, 0}
-
-      # from Gregorian seconds
-      iex> NaiveDateTime.add(~N[0000-01-01 00:00:00], 63579428950)
-      ~N[2014-10-02 00:29:10]
-
-  """
-  @spec add(t, integer, System.time_unit) :: t
-  def add(%NaiveDateTime{microsecond: {_, precision}, calendar: calendar} = naive_datetime,
-          integer, unit \\ :second) when is_integer(integer) do
-    ppd = System.convert_time_unit(86400, :second, unit)
-    naive_datetime
-    |> to_iso_days()
-    |> Calendar.ISO.add_day_fraction_to_iso_days(integer, ppd)
-    |> from_iso_days(calendar, precision)
-  end
-
-  @doc """
-  Subtracts `naive_datetime2` from `naive_datetime1`.
-
-  The answer can be returned in any `unit` available from `t:System.time_unit/0`.
-
-  This function returns the difference in seconds where seconds are measured
-  according to `Calendar.ISO`.
-
-  ## Examples
-
-      iex> NaiveDateTime.diff(~N[2014-10-02 00:29:12], ~N[2014-10-02 00:29:10])
-      2
-      iex> NaiveDateTime.diff(~N[2014-10-02 00:29:12], ~N[2014-10-02 00:29:10], :microsecond)
-      2_000_000
-      iex> NaiveDateTime.diff(~N[2014-10-02 00:29:10.042], ~N[2014-10-02 00:29:10.021], :millisecond)
-      21
-      iex> NaiveDateTime.diff(~N[2014-10-02 00:29:10], ~N[2014-10-02 00:29:12])
-      -2
-
-      # to Gregorian seconds
-      iex> NaiveDateTime.diff(~N[2014-10-02 00:29:10], ~N[0000-01-01 00:00:00])
-      63579428950
-
-  """
-  @spec diff(t, t, System.time_unit) :: integer
-  def diff(%NaiveDateTime{} = naive_datetime1,
-           %NaiveDateTime{} = naive_datetime2,
-           unit \\ :second) do
-    if not Calendar.compatible_calendars?(naive_datetime1.calendar, naive_datetime2.calendar) do
-      raise ArgumentError, "cannot calculate the difference between #{inspect naive_datetime1} and #{inspect naive_datetime2} because their calendars are not compatible and thus the result would be ambiguous"
-    end
-
-    units1 = naive_datetime1 |> to_iso_days() |> Calendar.ISO.iso_days_to_unit(unit)
-    units2 = naive_datetime2 |> to_iso_days() |> Calendar.ISO.iso_days_to_unit(unit)
-    units1 - units2
-  end
-
-  @doc """
-  Converts a `NaiveDateTime` into a `Date`.
-
-  Because `Date` does not hold time information,
-  data will be lost during the conversion.
-
-  ## Examples
-
-      iex> NaiveDateTime.to_date(~N[2002-01-13 23:00:07])
-      ~D[2002-01-13]
-
-  """
-  @spec to_date(t) :: Date.t
-  def to_date(%NaiveDateTime{year: year, month: month, day: day, calendar: calendar}) do
-    %Date{year: year, month: month, day: day, calendar: calendar}
-  end
-
-  @doc """
-  Converts a `NaiveDateTime` into `Time`.
-
-  Because `Time` does not hold date information,
-  data will be lost during the conversion.
-
-  ## Examples
-
-      iex> NaiveDateTime.to_time(~N[2002-01-13 23:00:07])
-      ~T[23:00:07]
-
-  """
-  @spec to_time(t) :: Time.t
-  def to_time(%NaiveDateTime{hour: hour, minute: minute, second: second, microsecond: microsecond, calendar: calendar}) do
-    %Time{hour: hour, minute: minute, second: second, microsecond: microsecond, calendar: calendar}
-  end
-
-  @doc """
-  Converts the given naive datetime to a string according to its calendar.
-
-  ### Examples
-
-      iex> NaiveDateTime.to_string(~N[2000-02-28 23:00:13])
-      "2000-02-28 23:00:13"
-      iex> NaiveDateTime.to_string(~N[2000-02-28 23:00:13.001])
-      "2000-02-28 23:00:13.001"
-
-  This function can also be used to convert a DateTime to a string without
-  the time zone information:
-
-      iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "CET",
-      ...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
-      ...>                utc_offset: 3600, std_offset: 0, time_zone: "Europe/Warsaw"}
-      iex> NaiveDateTime.to_string(dt)
-      "2000-02-29 23:00:07"
-
-  """
-  @spec to_string(Calendar.naive_datetime) :: String.t
-  def to_string(naive_datetime)
-
-  def to_string(%{calendar: calendar, year: year, month: month, day: day,
-                  hour: hour, minute: minute, second: second, microsecond: microsecond}) do
-    calendar.naive_datetime_to_string(year, month, day, hour, minute, second, microsecond)
-  end
-
-  @doc """
-  Parses the extended "Date and time of day" format described by
-  [ISO 8601:2004](https://en.wikipedia.org/wiki/ISO_8601).
-
-  Timezone offset may be included in the string but they will be
-  simply discarded as such information is not included in naive date
-  times.
-
-  As specified in the standard, the separator "T" may be omitted if
-  desired as there is no ambiguity within this function.
-
-  Time representations with reduced accuracy are not supported.
-
-  Note that while ISO8601 allows datetimes to specify 24:00:00 as the
-  zero hour of the next day, this notation is not supported by Elixir.
-
-  ## Examples
-
-      iex> NaiveDateTime.from_iso8601("2015-01-23 23:50:07")
-      {:ok, ~N[2015-01-23 23:50:07]}
-      iex> NaiveDateTime.from_iso8601("2015-01-23T23:50:07")
-      {:ok, ~N[2015-01-23 23:50:07]}
-      iex> NaiveDateTime.from_iso8601("2015-01-23T23:50:07Z")
-      {:ok, ~N[2015-01-23 23:50:07]}
-
-      iex> NaiveDateTime.from_iso8601("2015-01-23 23:50:07.0")
-      {:ok, ~N[2015-01-23 23:50:07.0]}
-      iex> NaiveDateTime.from_iso8601("2015-01-23 23:50:07,0123456")
-      {:ok, ~N[2015-01-23 23:50:07.012345]}
-      iex> NaiveDateTime.from_iso8601("2015-01-23 23:50:07.0123456")
-      {:ok, ~N[2015-01-23 23:50:07.012345]}
-      iex> NaiveDateTime.from_iso8601("2015-01-23T23:50:07.123Z")
-      {:ok, ~N[2015-01-23 23:50:07.123]}
-
-      iex> NaiveDateTime.from_iso8601("2015-01-23P23:50:07")
-      {:error, :invalid_format}
-      iex> NaiveDateTime.from_iso8601("2015:01:23 23-50-07")
-      {:error, :invalid_format}
-      iex> NaiveDateTime.from_iso8601("2015-01-23 23:50:07A")
-      {:error, :invalid_format}
-      iex> NaiveDateTime.from_iso8601("2015-01-23 23:50:61")
-      {:error, :invalid_time}
-      iex> NaiveDateTime.from_iso8601("2015-01-32 23:50:07")
-      {:error, :invalid_date}
-
-      iex> NaiveDateTime.from_iso8601("2015-01-23T23:50:07.123+02:30")
-      {:ok, ~N[2015-01-23 23:50:07.123]}
-      iex> NaiveDateTime.from_iso8601("2015-01-23T23:50:07.123+00:00")
-      {:ok, ~N[2015-01-23 23:50:07.123]}
-      iex> NaiveDateTime.from_iso8601("2015-01-23T23:50:07.123-02:30")
-      {:ok, ~N[2015-01-23 23:50:07.123]}
-      iex> NaiveDateTime.from_iso8601("2015-01-23T23:50:07.123-00:00")
-      {:error, :invalid_format}
-      iex> NaiveDateTime.from_iso8601("2015-01-23T23:50:07.123-00:60")
-      {:error, :invalid_format}
-      iex> NaiveDateTime.from_iso8601("2015-01-23T23:50:07.123-24:00")
-      {:error, :invalid_format}
-
-  """
-  @spec from_iso8601(String.t, Calendar.calendar) :: {:ok, t} | {:error, atom}
-  def from_iso8601(string, calendar \\ Calendar.ISO)
-
-  def from_iso8601(<<year::4-bytes, ?-, month::2-bytes, ?-, day::2-bytes, sep,
-                     hour::2-bytes, ?:, min::2-bytes, ?:, sec::2-bytes, rest::binary>>, calendar) when sep in [?\s, ?T] do
-    with {year, ""} <- Integer.parse(year),
-         {month, ""} <- Integer.parse(month),
-         {day, ""} <- Integer.parse(day),
-         {hour, ""} <- Integer.parse(hour),
-         {min, ""} <- Integer.parse(min),
-         {sec, ""} <- Integer.parse(sec),
-         {microsec, rest} <- Calendar.ISO.parse_microsecond(rest),
-         {_offset, ""} <- Calendar.ISO.parse_offset(rest) do
-      with {:ok, utc_date} <- new(year, month, day, hour, min, sec, microsec, Calendar.ISO),
-           do: convert(utc_date, calendar)
-    else
-      _ -> {:error, :invalid_format}
-    end
-  end
-
-  def from_iso8601(<<_::binary>>, _calendar) do
-    {:error, :invalid_format}
-  end
-
-  @doc """
-  Parses the extended "Date and time of day" format described by
-  [ISO 8601:2004](https://en.wikipedia.org/wiki/ISO_8601).
-
-  Raises if the format is invalid.
-
-  ## Examples
-
-      iex> NaiveDateTime.from_iso8601!("2015-01-23T23:50:07.123Z")
-      ~N[2015-01-23 23:50:07.123]
-      iex> NaiveDateTime.from_iso8601!("2015-01-23T23:50:07,123Z")
-      ~N[2015-01-23 23:50:07.123]
-      iex> NaiveDateTime.from_iso8601!("2015-01-23P23:50:07")
-      ** (ArgumentError) cannot parse "2015-01-23P23:50:07" as naive datetime, reason: :invalid_format
-
-  """
-  @spec from_iso8601!(String.t, Calendar.calendar) :: t | no_return
-  def from_iso8601!(string, calendar \\ Calendar.ISO) do
-    case from_iso8601(string, calendar) do
-      {:ok, value} ->
-        value
-      {:error, reason} ->
-        raise ArgumentError, "cannot parse #{inspect string} as naive datetime, reason: #{inspect reason}"
-    end
-  end
-
-  @doc """
-  Converts the given naive datetime to
-  [ISO 8601:2004](https://en.wikipedia.org/wiki/ISO_8601).
-
-  By default, `NaiveDateTime.to_iso8601/2` returns naive datetimes formatted in the "extended"
-  format, for human readability. It also supports the "basic" format through passing the `:basic` option.
-
-  Only supports converting naive datetimes which are in the ISO calendar,
-  attempting to convert naive datetimes from other calendars will raise.
-
-  ### Examples
-
-      iex> NaiveDateTime.to_iso8601(~N[2000-02-28 23:00:13])
-      "2000-02-28T23:00:13"
-
-      iex> NaiveDateTime.to_iso8601(~N[2000-02-28 23:00:13.001])
-      "2000-02-28T23:00:13.001"
-
-      iex> NaiveDateTime.to_iso8601(~N[2000-02-28 23:00:13.001], :basic)
-      "20000228T230013.001"
-
-  This function can also be used to convert a DateTime to ISO8601 without
-  the time zone information:
-
-      iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "CET",
-      ...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
-      ...>                utc_offset: 3600, std_offset: 0, time_zone: "Europe/Warsaw"}
-      iex> NaiveDateTime.to_iso8601(dt)
-      "2000-02-29T23:00:07"
-
-  """
-  @spec to_iso8601(Calendar.naive_datetime, :basic | :extended) :: String.t
-  def to_iso8601(naive_datetime, format \\ :extended)
-
-  def to_iso8601(%{year: year, month: month, day: day,
-                   hour: hour, minute: minute, second: second, microsecond: microsecond, calendar:
-    Calendar.ISO}, format) when format in [:basic, :extended] do
-    Calendar.ISO.naive_datetime_to_iso8601(year, month, day, hour, minute, second, microsecond, format)
-  end
-
-  def to_iso8601(%{year: _, month: _, day: _,
-                   hour: _, minute: _, second: _, microsecond: _, calendar: _} = naive_datetime, format) when format in [:basic, :extended] do
-    naive_datetime
-    |> convert!(Calendar.ISO)
-    |> to_iso8601(format)
-  end
-
-  def to_iso8601(_date, format) do
-    raise ArgumentError, "NaiveDateTime.to_iso8601/2 expects format to be :extended or :basic, got: #{inspect format}"
-  end
-
-  @doc """
-  Converts a `NaiveDateTime` struct to an Erlang datetime tuple.
-
-  Only supports converting naive datetimes which are in the ISO calendar,
-  attempting to convert naive datetimes from other calendars will raise.
-
-  WARNING: Loss of precision may occur, as Erlang time tuples only store
-  hour/minute/second.
-
-  ## Examples
-
-      iex> NaiveDateTime.to_erl(~N[2000-01-01 13:30:15])
-      {{2000, 1, 1}, {13, 30, 15}}
-
-  This function can also be used to convert a DateTime to a erl format
-  without the time zone information:
-
-      iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "CET",
-      ...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
-      ...>                utc_offset: 3600, std_offset: 0, time_zone: "Europe/Warsaw"}
-      iex> NaiveDateTime.to_erl(dt)
-      {{2000, 2, 29}, {23, 00, 07}}
-
-  """
-  @spec to_erl(t) :: :calendar.datetime
-  def to_erl(naive_datetime)
-
-  @spec to_erl(Calendar.time) :: :calendar.time
-  def to_erl(%{calendar: _, year: _, month: _, day: _,
-               hour: _, minute: _, second: _} = naive_datetime) do
-    %{year: year, month: month, day: day,
-      hour: hour, minute: minute, second: second} = convert!(naive_datetime, Calendar.ISO)
-    {{year, month, day}, {hour, minute, second}}
-  end
-
-  @doc """
-  Converts an Erlang datetime tuple to a `NaiveDateTime` struct.
-
-  Attempting to convert an invalid ISO calendar date will produce an error tuple.
-
-  ## Examples
-
-      iex> NaiveDateTime.from_erl({{2000, 1, 1}, {13, 30, 15}})
-      {:ok, ~N[2000-01-01 13:30:15]}
-      iex> NaiveDateTime.from_erl({{2000, 1, 1}, {13, 30, 15}}, {5000, 3})
-      {:ok, ~N[2000-01-01 13:30:15.005]}
-      iex> NaiveDateTime.from_erl({{2000, 13, 1}, {13, 30, 15}})
-      {:error, :invalid_date}
-      iex> NaiveDateTime.from_erl({{2000, 13, 1},{13, 30, 15}})
-      {:error, :invalid_date}
-
-  """
-  @spec from_erl(:calendar.datetime, Calendar.microsecond) :: {:ok, t} | {:error, atom}
-  def from_erl(tuple, microsecond \\ {0, 0}, calendar \\ Calendar.ISO)
-
-  def from_erl({{year, month, day}, {hour, minute, second}}, microsecond, calendar) do
-    with {:ok, utc_date} <- new(year, month, day, hour, minute, second, microsecond),
-         do: convert(utc_date, calendar)
-  end
-
-   @doc """
-  Converts an Erlang datetime tuple to a `NaiveDateTime` struct.
-
-  Raises if the datetime is invalid.
-  Attempting to convert an invalid ISO calendar date will produce an error tuple.
-
-  ## Examples
-
-      iex> NaiveDateTime.from_erl!({{2000, 1, 1}, {13, 30, 15}})
-      ~N[2000-01-01 13:30:15]
-      iex> NaiveDateTime.from_erl!({{2000, 1, 1}, {13, 30, 15}}, {5000, 3})
-      ~N[2000-01-01 13:30:15.005]
-      iex> NaiveDateTime.from_erl!({{2000, 13, 1}, {13, 30, 15}})
-      ** (ArgumentError) cannot convert {{2000, 13, 1}, {13, 30, 15}} to naive datetime, reason: :invalid_date
-
-  """
-  @spec from_erl!(:calendar.datetime, Calendar.microsecond) :: t | no_return
-  def from_erl!(tuple, microsecond \\ {0, 0}) do
-    case from_erl(tuple, microsecond) do
-      {:ok, value} ->
-        value
-      {:error, reason} ->
-        raise ArgumentError, "cannot convert #{inspect tuple} to naive datetime, reason: #{inspect reason}"
-    end
-  end
-
-  @doc """
-  Compares two `NaiveDateTime` structs.
-
-  Returns `:gt` if first is later than the second
-  and `:lt` for vice versa. If the two NaiveDateTime
-  are equal `:eq` is returned.
-
-  ## Examples
-
-      iex> NaiveDateTime.compare(~N[2016-04-16 13:30:15], ~N[2016-04-28 16:19:25])
-      :lt
-      iex> NaiveDateTime.compare(~N[2016-04-16 13:30:15.1], ~N[2016-04-16 13:30:15.01])
-      :gt
-
-  This function can also be used to compare a DateTime without
-  the time zone information:
-
-      iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "CET",
-      ...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
-      ...>                utc_offset: 3600, std_offset: 0, time_zone: "Europe/Warsaw"}
-      iex> NaiveDateTime.compare(dt, ~N[2000-02-29 23:00:07])
-      :eq
-      iex> NaiveDateTime.compare(dt, ~N[2000-01-29 23:00:07])
-      :gt
-      iex> NaiveDateTime.compare(dt, ~N[2000-03-29 23:00:07])
-      :lt
-
-  """
-  @spec compare(Calendar.naive_datetime, Calendar.naive_datetime) :: :lt | :eq | :gt
-  def compare(%{calendar: calendar1} = naive_datetime1, %{calendar: calendar2} = naive_datetime2) do
-    if Calendar.compatible_calendars?(calendar1, calendar2) do
-      case {to_iso_days(naive_datetime1), to_iso_days(naive_datetime2)} do
-        {first, second} when first > second -> :gt
-        {first, second} when first < second -> :lt
-        _ -> :eq
-      end
-    else
-      raise ArgumentError, """
-      cannot compare #{inspect naive_datetime1} with #{inspect naive_datetime2}.
-
-      This comparison would be ambiguous as their calendars have incompatible day rollover moments.
-      Specify an exact time of day (using `DateTime`s) to resolve this ambiguity
-      """
-    end
-  end
-
-  @doc """
-  Converts the given `naive_datetime` from one calendar to another.
-
-  If it is not possible to convert unambiguously between the calendars
-  (see `Calendar.compatible_calendars?/2`), an `{:error, :incompatible_calendars}` tuple
-  is returned.
-
-  ## Examples
-
-  Imagine someone implements `Calendar.Holocene`, a calendar based on the
-  Gregorian calendar that adds exactly 10,000 years to the current Gregorian
-  year:
-
-      iex> NaiveDateTime.convert(~N[2000-01-01 13:30:15], Calendar.Holocene)
-      {:ok, %NaiveDateTime{calendar: Calendar.Holocene, year: 12000, month: 1, day: 1,
-                           hour: 13, minute: 30, second: 15, microsecond: {0, 0}}}
-
-  """
-  @spec convert(Calendar.naive_datetime, Calendar.calendar) :: {:ok, t} | {:error, :incompatible_calendars}
-  def convert(%{calendar: calendar, year: year, month: month, day: day,
-                hour: hour, minute: minute, second: second, microsecond: microsecond}, calendar) do
-    {:ok, %NaiveDateTime{calendar: calendar, year: year, month: month, day: day,
-                         hour: hour, minute: minute, second: second, microsecond: microsecond}}
-  end
-
-  def convert(%{calendar: ndt_calendar, microsecond: {_, precision}} = naive_datetime, calendar) do
-    if Calendar.compatible_calendars?(ndt_calendar, calendar) do
-      result_naive_datetime =
-        naive_datetime
-        |> to_iso_days
-        |> from_iso_days(calendar, precision)
-      {:ok, result_naive_datetime}
-    else
-      {:error, :incompatible_calendars}
-    end
-  end
-
-  @doc """
-  Converts the given `naive_datetime` from one calendar to another.
-
-  If it is not possible to convert unambiguously between the calendars
-  (see `Calendar.compatible_calendars?/2`), an ArgumentError is raised.
-
-  ## Examples
-
-  Imagine someone implements `Calendar.Holocene`, a calendar based on the
-  Gregorian calendar that adds exactly 10,000 years to the current Gregorian
-  year:
-
-      iex> NaiveDateTime.convert!(~N[2000-01-01 13:30:15], Calendar.Holocene)
-      %NaiveDateTime{calendar: Calendar.Holocene, year: 12000, month: 1, day: 1,
-                     hour: 13, minute: 30, second: 15, microsecond: {0, 0}}
-
-  """
-  @spec convert!(Calendar.naive_datetime, Calendar.calendar) :: t
-  def convert!(naive_datetime, calendar) do
-    case convert(naive_datetime, calendar) do
-      {:ok, value} ->
-        value
-      {:error, :incompatible_calendars} ->
-        raise ArgumentError, "cannot convert #{inspect naive_datetime} to target calendar #{inspect calendar}, reason: #{inspect naive_datetime.calendar} and #{inspect calendar} have different day rollover moments, making this conversion ambiguous"
-    end
-  end
-
-  ## Helpers
-
-  defp to_iso_days(%{calendar: calendar, year: year, month: month, day: day,
-                     hour: hour, minute: minute, second: second, microsecond: microsecond}) do
-    calendar.naive_datetime_to_iso_days(year, month, day, hour, minute, second, microsecond)
-  end
-
-  defp from_iso_days(iso_days, calendar, precision) do
-    {year, month, day, hour, minute, second, {microsecond, _}} =
-      calendar.naive_datetime_from_iso_days(iso_days)
-    %NaiveDateTime{calendar: calendar, year: year, month: month, day: day,
-                   hour: hour, minute: minute, second: second, microsecond: {microsecond, precision}}
-  end
-
-  defimpl String.Chars do
-    def to_string(%{calendar: calendar, year: year, month: month, day: day,
-                    hour: hour, minute: minute, second: second, microsecond: microsecond}) do
-      calendar.naive_datetime_to_string(year, month, day, hour, minute, second, microsecond)
-    end
-  end
-
-  defimpl Inspect do
-    def inspect(%{calendar: Calendar.ISO, year: year, month: month, day: day,
-                  hour: hour, minute: minute, second: second, microsecond: microsecond}, _) do
-      formatted = Calendar.ISO.naive_datetime_to_string(year, month, day, hour, minute, second, microsecond)
-      "~N[" <> formatted <> "]"
-    end
-
-    def inspect(naive, opts) do
-      Inspect.Any.inspect(naive, opts)
-    end
-  end
-end

lib/elixir/lib/calendar/time.ex

@@ -1,491 +0,0 @@
-defmodule Time do
-  @moduledoc """
-  A Time struct and functions.
-
-  The Time struct contains the fields hour, minute, second and microseconds.
-  New times can be built with the `new/4` function or using the `~T`
-  sigil:
-
-      iex> ~T[23:00:07.001]
-      ~T[23:00:07.001]
-
-  Both `new/4` and sigil return a struct where the time fields can
-  be accessed directly:
-
-      iex> time = ~T[23:00:07.001]
-      iex> time.hour
-      23
-      iex> time.microsecond
-      {1000, 3}
-
-  The functions on this module work with the `Time` struct as well
-  as any struct that contains the same fields as the `Time` struct,
-  such as `NaiveDateTime` and `DateTime`. Such functions expect
-  `t:Calendar.time/0` in their typespecs (instead of `t:t/0`).
-
-  Developers should avoid creating the Time structs directly
-  and instead rely on the functions provided by this module as well
-  as the ones in 3rd party calendar libraries.
-
-  ## Comparing times
-
-  Comparisons in Elixir using `==`, `>`, `<` and similar are structural
-  and based on the `Time` struct fields. For proper comparison between
-  times, use the `compare/2` function.
-  """
-
-  @enforce_keys [:hour, :minute, :second]
-  defstruct [:hour, :minute, :second, microsecond: {0, 0}, calendar: Calendar.ISO]
-
-  @type t :: %Time{hour: Calendar.hour, minute: Calendar.minute,
-                   second: Calendar.second, microsecond: Calendar.microsecond, calendar: Calendar.calendar}
-
-  @doc """
-  Returns the current time in UTC.
-
-  ## Examples
-
-      iex> time = Time.utc_now()
-      iex> time.hour >= 0
-      true
-
-  """
-  @spec utc_now(Calendar.calendar) :: t
-  def utc_now(calendar \\ Calendar.ISO) do
-    {:ok, _, {hour, minute, second}, microsecond} = Calendar.ISO.from_unix(:os.system_time, :native)
-    iso_time = %Time{hour: hour, minute: minute, second: second, microsecond: microsecond, calendar: Calendar.ISO}
-    convert!(iso_time, calendar)
-  end
-
-  @doc """
-  Builds a new time.
-
-  Expects all values to be integers. Returns `{:ok, time}` if each
-  entry fits its appropriate range, returns `{:error, reason}` otherwise.
-
-  Note a time may have 60 seconds in case of leap seconds. Microseconds
-  can also be given with a precision, which must be an integer between
-  0 and 6.
-
-  ## Examples
-
-      iex> Time.new(0, 0, 0, 0)
-      {:ok, ~T[00:00:00.000000]}
-      iex> Time.new(23, 59, 59, 999_999)
-      {:ok, ~T[23:59:59.999999]}
-      iex> Time.new(23, 59, 60, 999_999)
-      {:ok, ~T[23:59:60.999999]}
-
-      # Time with microseconds and their precision
-      iex> Time.new(23, 59, 60, {10_000, 2})
-      {:ok, ~T[23:59:60.01]}
-
-      iex> Time.new(24, 59, 59, 999_999)
-      {:error, :invalid_time}
-      iex> Time.new(23, 60, 59, 999_999)
-      {:error, :invalid_time}
-      iex> Time.new(23, 59, 61, 999_999)
-      {:error, :invalid_time}
-      iex> Time.new(23, 59, 59, 1_000_000)
-      {:error, :invalid_time}
-
-      # Invalid precision
-      Time.new(23, 59, 59, {999_999, 10})
-      {:error, :invalid_time}
-
-  """
-  @spec new(Calendar.hour, Calendar.minute, Calendar.second, Calendar.microsecond, Calendar.calendar) ::
-        {:ok, t} | {:error, atom}
-  def new(hour, minute, second, microsecond \\ {0, 0}, calendar \\ Calendar.ISO)
-
-  def new(hour, minute, second, microsecond, calendar) when is_integer(microsecond) do
-    new(hour, minute, second, {microsecond, 6}, calendar)
-  end
-
-  def new(hour, minute, second, {microsecond, precision}, calendar)
-      when is_integer(hour) and is_integer(minute) and is_integer(second) and
-           is_integer(microsecond) and is_integer(precision) do
-    case calendar.valid_time?(hour, minute, second, {microsecond, precision}) do
-      true ->
-        {:ok, %Time{hour: hour, minute: minute, second: second, microsecond: {microsecond, precision}, calendar: calendar}}
-      false ->
-        {:error, :invalid_time}
-    end
-  end
-
-  @doc """
-  Converts the given `time` to a string.
-
-  ### Examples
-
-      iex> Time.to_string(~T[23:00:00])
-      "23:00:00"
-      iex> Time.to_string(~T[23:00:00.001])
-      "23:00:00.001"
-      iex> Time.to_string(~T[23:00:00.123456])
-      "23:00:00.123456"
-
-      iex> Time.to_string(~N[2015-01-01 23:00:00.001])
-      "23:00:00.001"
-      iex> Time.to_string(~N[2015-01-01 23:00:00.123456])
-      "23:00:00.123456"
-
-  """
-  @spec to_string(Calendar.time) :: String.t
-  def to_string(time)
-
-  def to_string(%{hour: hour, minute: minute, second: second, microsecond: microsecond, calendar: calendar}) do
-    calendar.time_to_string(hour, minute, second, microsecond)
-  end
-
-  @doc """
-  Parses the extended "Local time" format described by
-  [ISO 8601:2004](https://en.wikipedia.org/wiki/ISO_8601).
-
-  Timezone offset may be included in the string but they will be
-  simply discarded as such information is not included in times.
-
-  As specified in the standard, the separator "T" may be omitted if
-  desired as there is no ambiguity within this function.
-
-  Time representations with reduced accuracy are not supported.
-
-  Note that while ISO8601 allows times to specify 24:00:00 as the
-  zero hour of the next day, this notation is not supported by Elixir.
-
-  ## Examples
-
-      iex> Time.from_iso8601("23:50:07")
-      {:ok, ~T[23:50:07]}
-      iex> Time.from_iso8601("23:50:07Z")
-      {:ok, ~T[23:50:07]}
-      iex> Time.from_iso8601("T23:50:07Z")
-      {:ok, ~T[23:50:07]}
-
-      iex> Time.from_iso8601("23:50:07,0123456")
-      {:ok, ~T[23:50:07.012345]}
-      iex> Time.from_iso8601("23:50:07.0123456")
-      {:ok, ~T[23:50:07.012345]}
-      iex> Time.from_iso8601("23:50:07.123Z")
-      {:ok, ~T[23:50:07.123]}
-
-      iex> Time.from_iso8601("2015:01:23 23-50-07")
-      {:error, :invalid_format}
-      iex> Time.from_iso8601("23:50:07A")
-      {:error, :invalid_format}
-      iex> Time.from_iso8601("23:50:07.")
-      {:error, :invalid_format}
-      iex> Time.from_iso8601("23:50:61")
-      {:error, :invalid_time}
-
-  """
-  @spec from_iso8601(String.t) :: {:ok, t} | {:error, atom}
-  def from_iso8601(string, calendar \\ Calendar.ISO)
-
-  def from_iso8601(<<?T, h, rest::binary>>, calendar) when h in ?0..?9 do
-    from_iso8601(<<h, rest::binary>>, calendar)
-  end
-
-  def from_iso8601(<<hour::2-bytes, ?:, min::2-bytes, ?:, sec::2-bytes, rest::binary>>, calendar) do
-    with {hour, ""} <- Integer.parse(hour),
-         {min, ""} <- Integer.parse(min),
-         {sec, ""} <- Integer.parse(sec),
-         {microsec, rest} <- Calendar.ISO.parse_microsecond(rest),
-         {_offset, ""} <- Calendar.ISO.parse_offset(rest) do
-      with {:ok, utc_time} <- new(hour, min, sec, microsec, Calendar.ISO),
-           do: convert(utc_time, calendar)
-    else
-      _ -> {:error, :invalid_format}
-    end
-  end
-
-  def from_iso8601(<<_::binary>>, _calendar) do
-    {:error, :invalid_format}
-  end
-
-  @doc """
-  Parses the extended "Local time" format described by
-  [ISO 8601:2004](https://en.wikipedia.org/wiki/ISO_8601).
-
-  Raises if the format is invalid.
-
-  ## Examples
-
-      iex> Time.from_iso8601!("23:50:07,123Z")
-      ~T[23:50:07.123]
-      iex> Time.from_iso8601!("23:50:07.123Z")
-      ~T[23:50:07.123]
-      iex> Time.from_iso8601!("2015:01:23 23-50-07")
-      ** (ArgumentError) cannot parse "2015:01:23 23-50-07" as time, reason: :invalid_format
-  """
-  @spec from_iso8601!(String.t) :: t
-  def from_iso8601!(string) do
-    case from_iso8601(string) do
-      {:ok, value} ->
-        value
-      {:error, reason} ->
-        raise ArgumentError, "cannot parse #{inspect string} as time, reason: #{inspect reason}"
-    end
-  end
-
-  @doc """
-  Converts the given time to
-  [ISO 8601:2004](https://en.wikipedia.org/wiki/ISO_8601).
-
-  By default, `Time.to_iso8601/2` returns times formatted in the "extended"
-  format, for human readability. It also supports the "basic" format through
-  passing the `:basic` option.
-
-  ### Examples
-
-      iex> Time.to_iso8601(~T[23:00:13])
-      "23:00:13"
-
-      iex> Time.to_iso8601(~T[23:00:13.001])
-      "23:00:13.001"
-
-      iex> Time.to_iso8601(~T[23:00:13.001], :basic)
-      "230013.001"
-
-      iex> Time.to_iso8601(~N[2010-04-17 23:00:13])
-      "23:00:13"
-
-  """
-  @spec to_iso8601(Calendar.time, :extended | :basic) :: String.t
-  def to_iso8601(time, format \\ :extended) when format in [:extended, :basic] do
-    %{hour: hour, minute: minute, second: second, microsecond: microsecond} = convert!(time, Calendar.ISO)
-    Calendar.ISO.time_to_iso8601(hour, minute, second, microsecond, format)
-  end
-
-  @doc """
-  Converts given `time` to an Erlang time tuple.
-
-  WARNING: Loss of precision may occur, as Erlang time tuples
-  only contain hours/minutes/seconds.
-
-  ## Examples
-
-      iex> Time.to_erl(~T[23:30:15.999])
-      {23, 30, 15}
-
-      iex> Time.to_erl(~N[2010-04-17 23:30:15.999])
-      {23, 30, 15}
-
-  """
-  @spec to_erl(Calendar.time) :: :calendar.time
-  def to_erl(time) do
-    %{hour: hour, minute: minute, second: second} = convert!(time, Calendar.ISO)
-    {hour, minute, second}
-  end
-
-  @doc """
-  Converts an Erlang time tuple to a `Time` struct.
-
-  ## Examples
-
-      iex> Time.from_erl({23, 30, 15}, {5000, 3})
-      {:ok, ~T[23:30:15.005]}
-      iex> Time.from_erl({24, 30, 15})
-      {:error, :invalid_time}
-
-  """
-  @spec from_erl(:calendar.time, Calendar.microsecond, Calendar.calendar) :: {:ok, t} | {:error, atom}
-  def from_erl(tuple, microsecond \\ {0, 0}, calendar \\ Calendar.ISO)
-
-  def from_erl({hour, minute, second}, microsecond, calendar) do
-    with {:ok, time} <- new(hour, minute, second, microsecond, Calendar.ISO),
-         do: convert(time, calendar)
-  end
-
-  @doc """
-  Converts an Erlang time tuple to a `Time` struct.
-
-  ## Examples
-
-      iex> Time.from_erl!({23, 30, 15})
-      ~T[23:30:15]
-      iex> Time.from_erl!({23, 30, 15}, {5000, 3})
-      ~T[23:30:15.005]
-      iex> Time.from_erl!({24, 30, 15})
-      ** (ArgumentError) cannot convert {24, 30, 15} to time, reason: :invalid_time
-
-  """
-  @spec from_erl!(:calendar.time, Calendar.microsecond, Calendar.calendar) :: t
-  def from_erl!(tuple, microsecond \\ {0, 0}, calendar \\ Calendar.ISO) do
-    case from_erl(tuple, microsecond, calendar) do
-      {:ok, value} ->
-        value
-      {:error, reason} ->
-        raise ArgumentError, "cannot convert #{inspect tuple} to time, reason: #{inspect reason}"
-    end
-  end
-
-  @doc """
-  Compares two time structs.
-
-  Returns `:gt` if first time is later than the second
-  and `:lt` for vice versa. If the two times are equal
-  `:eq` is returned.
-
-  ## Examples
-
-      iex> Time.compare(~T[16:04:16], ~T[16:04:28])
-      :lt
-      iex> Time.compare(~T[16:04:16], ~T[16:04:16])
-      :eq
-      iex> Time.compare(~T[16:04:16.01], ~T[16:04:16.001])
-      :gt
-
-  This function can also be used to compare across more
-  complex calendar types by considering only the time fields:
-
-      iex> Time.compare(~N[1900-01-01 16:04:16], ~N[2015-01-01 16:04:16])
-      :eq
-      iex> Time.compare(~N[2015-01-01 16:04:16], ~N[2015-01-01 16:04:28])
-      :lt
-      iex> Time.compare(~N[2015-01-01 16:04:16.01], ~N[2000-01-01 16:04:16.001])
-      :gt
-
-  """
-  @spec compare(Calendar.time, Calendar.time) :: :lt | :eq | :gt
-  def compare(%{calendar: calendar, hour: hour1, minute: minute1, second: second1, microsecond: {microsecond1, _}},
-              %{calendar: calendar, hour: hour2, minute: minute2, second: second2, microsecond: {microsecond2, _}}) do
-    case {{hour1, minute1, second1, microsecond1}, {hour2, minute2, second2, microsecond2}} do
-      {first, second} when first > second -> :gt
-      {first, second} when first < second -> :lt
-      _ -> :eq
-    end
-  end
-
-  def compare(time1, time2) do
-    {parts1, ppd1} = to_day_fraction(time1)
-    {parts2, ppd2} = to_day_fraction(time2)
-
-    case {parts1 * ppd2, parts2 * ppd1} do
-      {first, second} when first > second -> :gt
-      {first, second} when first < second -> :lt
-      _ -> :eq
-    end
-  end
-
-  @doc """
-  Converts given `time` to a different calendar.
-
-  Returns `{:ok, time}` if the conversion was successful,
-  or `{:error, reason}` if it was not, for some reason.
-
-  ## Examples
-
-  Imagine someone implements `Calendar.Holocene`, a calendar based on the
-  Gregorian calendar that adds exactly 10,000 years to the current Gregorian
-  year:
-
-      iex> Time.convert(~T[13:30:15], Calendar.Holocene)
-      {:ok, %Time{calendar: Calendar.Holocene, hour: 13, minute: 30, second: 15, microsecond: {0, 0}}}
-
-  """
-  @spec convert(Calendar.time, Calendar.calendar) :: {:ok, t} | {:error, atom}
-  def convert(%{calendar: calendar, hour: hour, minute: minute, second: second, microsecond: microsecond}, calendar) do
-    {:ok, %Time{calendar: calendar, hour: hour, minute: minute, second: second, microsecond: microsecond}}
-  end
-
-  def convert(%{microsecond: {_, precision}} = time, calendar) do
-    {hour, minute, second, {microsecond, _}} =
-      time
-      |> to_day_fraction()
-      |> calendar.time_from_day_fraction
-    {:ok, %Time{calendar: calendar, hour: hour, minute: minute, second: second,
-                microsecond: {microsecond, precision}}}
-  end
-
-  @doc """
-  Similar to `Time.convert/2`, but raises an `ArgumentError`
-  if the conversion between the two calendars is not possible.
-
-  ## Examples
-
-  Imagine someone implements `Calendar.Holocene`, a calendar based on the
-  Gregorian calendar that adds exactly 10,000 years to the current Gregorian
-  year:
-
-      iex> Time.convert!(~T[13:30:15], Calendar.Holocene)
-      %Time{calendar: Calendar.Holocene, hour: 13, minute: 30, second: 15, microsecond: {0, 0}}
-
-  """
-  @spec convert!(Calendar.time, Calendar.calendar) :: t
-  def convert!(time, calendar) do
-    case convert(time, calendar) do
-      {:ok, value} ->
-        value
-      {:error, reason} ->
-        raise ArgumentError, "cannot convert #{inspect time} to target calendar #{inspect calendar}, reason: #{inspect reason}"
-    end
-  end
-
-  @doc """
-  Returns the difference between two times, considering only the hour, minute
-  second and microsecond.
-
-  As with the `compare/2` function both `Time` structs and other structures
-  containing time can be used. If for instance a `NaiveDateTime` or `DateTime`
-  is passed, only the hour, month, second, and microsecond is considered. Any
-  additional information about a date or time zone is ignored when calculating
-  the difference.
-
-  The answer can be returned in any `unit` available from
-  `t:System.time_unit/0`. If the first unit is smaller than
-  the second, a negative number is returned.
-
-  This function returns the difference in seconds where seconds
-  are measured according to `Calendar.ISO`.
-
-  ## Examples
-
-      iex> Time.diff(~T[00:29:12], ~T[00:29:10])
-      2
-
-      # When passing a `NaiveDateTime` the date part is ignored.
-      iex> Time.diff(~N[2017-01-01 00:29:12], ~T[00:29:10])
-      2
-
-      # Two `NaiveDateTime` structs could have big differences in the date
-      # but only the time part is considered.
-      iex> Time.diff(~N[2017-01-01 00:29:12], (~N[1900-02-03 00:29:10]))
-      2
-
-      iex> Time.diff(~T[00:29:12], ~T[00:29:10], :microsecond)
-      2_000_000
-      iex> Time.diff(~T[00:29:10], ~T[00:29:12], :microsecond)
-      -2_000_000
-
-  """
-  @spec diff(Calendar.time, Calendar.time, System.time_unit) :: integer
-  def diff(time1, time2, unit \\ :second) do
-    fraction1 = to_day_fraction(time1)
-    fraction2 = to_day_fraction(time2)
-    Calendar.ISO.iso_days_to_unit({0, fraction1}, unit) -
-      Calendar.ISO.iso_days_to_unit({0, fraction2}, unit)
-  end
-
-  ## Helpers
-
-  defp to_day_fraction(%{hour: hour, minute: minute, second: second, microsecond: {_, _} = microsecond, calendar: calendar}) do
-    calendar.time_to_day_fraction(hour, minute, second, microsecond)
-  end
-
-  defimpl String.Chars do
-    def to_string(%{hour: hour, minute: minute, second: second, microsecond: microsecond, calendar: calendar}) do
-      calendar.time_to_string(hour, minute, second, microsecond)
-    end
-  end
-
-  defimpl Inspect do
-    def inspect(%{hour: hour, minute: minute, second: second, microsecond: microsecond, calendar: Calendar.ISO}, _) do
-      "~T[" <> Calendar.ISO.time_to_string(hour, minute, second, microsecond) <> "]"
-    end
-
-    def inspect(time, opts) do
-      Inspect.Any.inspect(time, opts)
-    end
-  end
-end

lib/elixir/lib/code.ex

@@ -2,120 +2,84 @@ defmodule Code do
   @moduledoc """
   Utilities for managing code compilation, code evaluation and code loading.
 
-  This module complements Erlang's [`:code` module](http://www.erlang.org/doc/man/code.html)
-  to add behaviour which is specific to Elixir. Almost all of the functions in this module
-  have global side effects on the behaviour of Elixir.
+  This module complements [Erlang's code module](http://www.erlang.org/doc/man/code.html)
+  to add behaviour which is specific to Elixir.
   """
 
   @doc """
-  Lists all loaded files.
-
-  ## Examples
-
-      Code.require_file("../eex/test/eex_test.exs")
-      List.first(Code.loaded_files) =~ "eex_test.exs" #=> true
-
+  List all loaded files.
   """
   def loaded_files do
     :elixir_code_server.call :loaded
   end
 
   @doc """
-  Removes files from the loaded files list.
+  Remove files from the loaded files list.
 
   The modules defined in the file are not removed;
   calling this function only removes them from the list,
   allowing them to be required again.
-
-  ## Examples
-
-      # Load EEx test code, unload file, check for functions still available
-      Code.load_file("../eex/test/eex_test.exs")
-      Code.unload_files(Code.loaded_files)
-      function_exported?(EExTest.Compiled, :before_compile, 0) #=> true
-
   """
   def unload_files(files) do
     :elixir_code_server.cast {:unload_files, files}
   end
 
   @doc """
-  Appends a path to the end of the Erlang VM code path list.
-
-  This is the list of directories the Erlang VM uses for
-  finding module code.
+  Append a path to the Erlang VM code path.
 
   The path is expanded with `Path.expand/1` before being appended.
-  If this path does not exist, an error is returned.
-
-  ## Examples
-
-      Code.append_path(".") #=> true
-
-      Code.append_path("/does_not_exist") #=> {:error, :bad_directory}
-
   """
   def append_path(path) do
-    :code.add_pathz(to_charlist(Path.expand path))
+    :code.add_pathz(to_char_list(Path.expand path))
   end
 
   @doc """
-  Prepends a path to the beginning of the Erlang VM code path list.
-
-  This is the list of directories the Erlang VM uses for finding
-  module code.
+  Prepend a path to the Erlang VM code path.
 
   The path is expanded with `Path.expand/1` before being prepended.
-  If this path does not exist, an error is returned.
-
-  ## Examples
-
-      Code.prepend_path(".") #=> true
-
-      Code.prepend_path("/does_not_exist") #=> {:error, :bad_directory}
-
   """
   def prepend_path(path) do
-    :code.add_patha(to_charlist(Path.expand path))
+    :code.add_patha(to_char_list(Path.expand path))
   end
 
   @doc """
-  Deletes a path from the Erlang VM code path list. This is the list of
-  directories the Erlang VM uses for finding module code.
-
-  The path is expanded with `Path.expand/1` before being deleted. If the
-  path does not exist it returns `false`.
-
-  ## Examples
-
-      Code.prepend_path(".")
-      Code.delete_path(".") #=> true
-
-      Code.delete_path("/does_not_exist") #=> false
+  Delete a path from the Erlang VM code path.
 
+  The path is expanded with `Path.expand/1` before being deleted.
   """
   def delete_path(path) do
-    :code.del_path(to_charlist(Path.expand path))
+    :code.del_path(to_char_list(Path.expand path))
   end
 
   @doc """
-  Evaluates the contents given by `string`.
+  Re-add paths given to the command line to keep their position
+  on the overall code path.
+
+  Some tools may change the code path by prepending new items but
+  still want the paths given by the user to have higher priority.
+  Calling this function guarantees the paths are re-added on
+  top of the user given ones.
+  """
+  @spec readd_paths() :: :ok
+  def readd_paths() do
+    {pa, pz} = :elixir_code_server.call(:paths)
+    :code.add_pathsa(pa)
+    :code.add_pathsz(pz)
+    :ok
+  end
+
+  @doc """
+  Evaluate the contents given by `string`.
 
   The `binding` argument is a keyword list of variable bindings.
   The `opts` argument is a keyword list of environment options.
 
-  **Warning**: `string` can be any Elixir code and will be executed with
-  the same privileges as the Erlang VM: this means that such code could
-  compromise the machine (for example by executing system commands).
-  Don't use `eval_string/3` with untrusted input (such as strings coming
-  from the network).
+  Those options can be:
 
-  ## Options
-
-  Options can be:
-
-    * `:file` - the file to be considered in the evaluation
-    * `:line` - the line on which the script starts
+    * `:file`               - the file to be considered in the evaluation
+    * `:line`               - the line on which the script starts
+    * `:delegate_locals_to` - delegate local calls to the given module,
+                              the default is to not delegate
 
   Additionally, the following scope values can be configured:
 
@@ -134,7 +98,7 @@ defmodule Code do
   Notice that setting any of the values above overrides Elixir's default
   values. For example, setting `:requires` to `[]`, will no longer
   automatically require the `Kernel` module; in the same way setting
-  `:macros` will no longer auto-import `Kernel` macros like `if/2`, `case/2`,
+  `:macros` will no longer auto-import `Kernel` macros like `if`, `case`,
   etc.
 
   Returns a tuple of the form `{value, binding}`,
@@ -156,7 +120,7 @@ defmodule Code do
       iex> Code.eval_string("a = a + b", [a: 1, b: 2])
       {3, [a: 3, b: 2]}
 
-  For convenience, you can pass `__ENV__/0` as the `opts` argument and
+  For convenience, you can pass `__ENV__` as the `opts` argument and
   all imports, requires and aliases defined in the current environment
   will be automatically carried over:
 
@@ -167,25 +131,20 @@ defmodule Code do
   def eval_string(string, binding \\ [], opts \\ [])
 
   def eval_string(string, binding, %Macro.Env{} = env) do
-    {value, binding, _env, _scope} = :elixir.eval to_charlist(string), binding, Map.to_list(env)
+    {value, binding, _env, _scope} = :elixir.eval to_char_list(string), binding, Map.to_list(env)
     {value, binding}
   end
 
   def eval_string(string, binding, opts) when is_list(opts) do
     validate_eval_opts(opts)
-    {value, binding, _env, _scope} = :elixir.eval to_charlist(string), binding, opts
+    {value, binding, _env, _scope} = :elixir.eval to_char_list(string), binding, opts
     {value, binding}
   end
 
   @doc """
-  Evaluates the quoted contents.
+  Evaluate the quoted contents.
 
-  **Warning**: Calling this function inside a macro is considered bad
-  practice as it will attempt to evaluate runtime values at compile time.
-  Macro arguments are typically transformed by unquoting them into the
-  returned quoted expressions (instead of evaluated).
-
-  See `eval_string/3` for a description of bindings and options.
+  See `eval_string/3` for a description of arguments and return values.
 
   ## Examples
 
@@ -193,7 +152,7 @@ defmodule Code do
       iex> Code.eval_quoted(contents, [a: 1, b: 2], file: __ENV__.file, line: __ENV__.line)
       {3, [a: 1, b: 2]}
 
-  For convenience, you can pass `__ENV__/0` as the `opts` argument and
+  For convenience, you can pass `__ENV__` as the `opts` argument and
   all options will be automatically extracted from the current environment:
 
       iex> contents = quote(do: var!(a) + var!(b))
@@ -252,7 +211,7 @@ defmodule Code do
   end
 
   @doc """
-  Converts the given string to its quoted form.
+  Convert the given string to its quoted form.
 
   Returns `{:ok, quoted_form}`
   if it succeeds, `{:error, {line, error, token}}` otherwise.
@@ -260,9 +219,9 @@ defmodule Code do
   ## Options
 
     * `:file` - the filename to be used in stacktraces
-      and the file reported in the `__ENV__/0` macro
+      and the file reported in the `__ENV__` variable
 
-    * `:line` - the line reported in the `__ENV__/0` macro
+    * `:line` - the line reported in the `__ENV__` variable
 
     * `:existing_atoms_only` - when `true`, raises an error
       when non-existing atoms are found by the tokenizer
@@ -276,11 +235,11 @@ defmodule Code do
   def string_to_quoted(string, opts \\ []) when is_list(opts) do
     file = Keyword.get opts, :file, "nofile"
     line = Keyword.get opts, :line, 1
-    :elixir.string_to_quoted(to_charlist(string), line, file, opts)
+    :elixir.string_to_quoted(to_char_list(string), line, file, opts)
   end
 
   @doc """
-  Converts the given string to its quoted form.
+  Convert the given string to its quoted form.
 
   It returns the ast if it succeeds,
   raises an exception otherwise. The exception is a `TokenMissingError`
@@ -292,7 +251,7 @@ defmodule Code do
   def string_to_quoted!(string, opts \\ []) when is_list(opts) do
     file = Keyword.get opts, :file, "nofile"
     line = Keyword.get opts, :line, 1
-    :elixir.string_to_quoted!(to_charlist(string), line, file, opts)
+    :elixir.string_to_quoted!(to_char_list(string), line, file, opts)
   end
 
   @doc """
@@ -310,7 +269,7 @@ defmodule Code do
   end
 
   @doc """
-  Loads the given file.
+  Load the given file.
 
   Accepts `relative_to` as an argument to tell where the file is located.
   If the file was already required/loaded, loads it again.
@@ -321,12 +280,6 @@ defmodule Code do
   Notice that if `load_file` is invoked by different processes concurrently,
   the target file will be loaded concurrently many times. Check `require_file/2`
   if you don't want a file to be loaded concurrently.
-
-  ## Examples
-
-      Code.load_file("eex_test.exs", "../eex/test") |> List.first
-      #=> {EExTest.Compiled, <<70, 79, 82, 49, ...>>}
-
   """
   def load_file(file, relative_to \\ nil) when is_binary(file) do
     file = find_file(file, relative_to)
@@ -341,28 +294,15 @@ defmodule Code do
 
   Accepts `relative_to` as an argument to tell where the file is located.
   The return value is the same as that of `load_file/2`. If the file was already
-  required/loaded, `require_file` doesn't do anything and returns `nil`.
+  required/loaded, doesn't do anything and returns `nil`.
 
   Notice that if `require_file` is invoked by different processes concurrently,
   the first process to invoke `require_file` acquires a lock and the remaining
-  ones will block until the file is available. I.e., if `require_file` is called
+  ones will block until the file is available. I.e. if `require_file` is called
   N times with a given file, it will be loaded only once. The first process to
   call `require_file` will get the list of loaded modules, others will get `nil`.
 
-  Check `load_file/2` if you want a file to be loaded multiple times. See also
-  `unload_files/1`
-
-  ## Examples
-
-  If the code is already loaded, it returns `nil`:
-
-      Code.require_file("eex_test.exs", "../eex/test") #=> nil
-
-  If the code is not loaded yet, it returns the same as `load_file/2`:
-
-      Code.require_file("eex_test.exs", "../eex/test") |> List.first
-      #=> {EExTest.Compiled, <<70, 79, 82, 49, ...>>}
-
+  Check `load_file/2` if you want a file to be loaded multiple times.
   """
   def require_file(file, relative_to \\ nil) when is_binary(file) do
     file = find_file(file, relative_to)
@@ -383,31 +323,18 @@ defmodule Code do
   Gets the compilation options from the code server.
 
   Check `compiler_options/1` for more information.
-
-  ## Examples
-
-      Code.compiler_options
-      #=> %{debug_info: true, docs: true,
-            warnings_as_errors: false, ignore_module_conflict: false}
-
   """
   def compiler_options do
-    :elixir_config.get :compiler_options
+    :elixir_code_server.call :compiler_options
   end
 
   @doc """
   Returns a list with the available compiler options.
 
   See `Code.compiler_options/1` for more info.
-
-  ## Examples
-
-      iex> Code.available_compiler_options
-      [:docs, :debug_info, :ignore_module_conflict, :relative_paths, :warnings_as_errors]
-
   """
   def available_compiler_options do
-    [:docs, :debug_info, :ignore_module_conflict, :relative_paths, :warnings_as_errors]
+    [:docs, :debug_info, :ignore_module_conflict, :warnings_as_errors]
   end
 
   @doc """
@@ -427,37 +354,17 @@ defmodule Code do
     * `:ignore_module_conflict` - when `true`, override modules that were
       already defined without raising errors, `false` by default
 
-    * `:relative_paths` - when `true`, use relative paths in quoted nodes,
-      warnings and errors generated by the compiler, `true` by default.
-      Note disabling this option won't affect runtime warnings and errors.
-
-    * `:warnings_as_errors` - causes compilation to fail when warnings are
+    * `:warnings_as_errors` - cause compilation to fail when warnings are
       generated
 
-  It returns the new list of compiler options.
-
-  ## Examples
-
-      Code.compiler_options(debug_info: true)
-      #=> %{debug_info: true, docs: true,
-            warnings_as_errors: false, ignore_module_conflict: false}
-
   """
   def compiler_options(opts) do
-    available = available_compiler_options()
-
-    Enum.each(opts, fn({key, value}) ->
-      cond do
-        key not in available ->
-          raise "unknown compiler option: #{inspect(key)}"
-        not is_boolean(value) ->
-          raise "compiler option #{inspect(key)} should be a boolean, got: #{inspect(value)}"
-        true ->
-          :ok
-      end
-    end)
-
-    :elixir_config.update :compiler_options, &Enum.into(opts, &1)
+    {opts, bad} = Keyword.split(opts, available_compiler_options)
+    if bad != [] do
+      bad = bad |> Keyword.keys |> Enum.join(", ")
+      raise ArgumentError, message: "unknown compiler options: #{bad}"
+    end
+    :elixir_code_server.cast {:compiler_options, opts}
   end
 
   @doc """
@@ -469,7 +376,7 @@ defmodule Code do
   For compiling many files at once, check `Kernel.ParallelCompiler.files/2`.
   """
   def compile_string(string, file \\ "nofile") when is_binary(file) do
-    :elixir_compiler.string to_charlist(string), file
+    :elixir_compiler.string to_char_list(string), file
   end
 
   @doc """
@@ -504,7 +411,7 @@ defmodule Code do
   module uses this function to check if a specific parser exists for a given
   URI scheme.
 
-  ## `ensure_compiled/1`
+  ## `Code.ensure_compiled/1`
 
   Elixir also contains an `ensure_compiled/1` function that is a
   superset of `ensure_loaded/1`.
@@ -513,29 +420,13 @@ defmodule Code do
   you may need to use a module that was not yet compiled, therefore
   it can't even be loaded.
 
-  When invoked, `ensure_compiled/1` halts the compilation of the caller
-  until the module given to `ensure_compiled/1` becomes available or
-  all files for the current project have been compiled. If compilation
-  finishes and the module is not available, an error tuple is returned.
-
-  `ensure_compiled/1` does not apply to dependencies, as dependencies
-  must be compiled upfront.
+  `ensure_compiled/1` halts the current process until the
+  module we are depending on is available.
 
   In most cases, `ensure_loaded/1` is enough. `ensure_compiled/1`
   must be used in rare cases, usually involving macros that need to
   invoke a module for callback information.
-
-  ## Examples
-
-      iex> Code.ensure_loaded(Atom)
-      {:module, Atom}
-
-      iex> Code.ensure_loaded(DoesNotExist)
-      {:error, :nofile}
-
   """
-  @spec ensure_loaded(module) ::
-        {:module, module} | {:error, :embedded | :badfile | :nofile | :on_load_failure}
   def ensure_loaded(module) when is_atom(module) do
     :code.ensure_loaded(module)
   end
@@ -546,14 +437,8 @@ defmodule Code do
   Similar to `ensure_loaded/1`, but returns `true` if the module
   is already loaded or was successfully loaded. Returns `false`
   otherwise.
-
-  ## Examples
-
-      iex> Code.ensure_loaded?(Atom)
-      true
-
   """
-  def ensure_loaded?(module) when is_atom(module) do
+  def ensure_loaded?(module) do
     match?({:module, ^module}, ensure_loaded(module))
   end
 
@@ -570,16 +455,18 @@ defmodule Code do
   Check `ensure_loaded/1` for more information on module loading
   and when to use `ensure_loaded/1` or `ensure_compiled/1`.
   """
-  @spec ensure_compiled(module) ::
-        {:module, module} | {:error, :embedded | :badfile | :nofile | :on_load_failure}
   def ensure_compiled(module) when is_atom(module) do
     case :code.ensure_loaded(module) do
       {:error, :nofile} = error ->
-        if is_pid(:erlang.get(:elixir_compiler_pid)) and
-           Kernel.ErrorHandler.ensure_compiled(module, :module) do
-          {:module, module}
-        else
-          error
+        case :erlang.get(:elixir_ensure_compiled) do
+          :undefined -> error
+          _ ->
+            try do
+              module.__info__(:module)
+              {:module, module}
+            rescue
+              UndefinedFunctionError -> error
+            end
         end
       other -> other
     end
@@ -592,12 +479,11 @@ defmodule Code do
   is already loaded or was successfully loaded and compiled.
   Returns `false` otherwise.
   """
-  @spec ensure_compiled?(module) :: boolean
-  def ensure_compiled?(module) when is_atom(module) do
+  def ensure_compiled?(module) do
     match?({:module, ^module}, ensure_compiled(module))
   end
 
-  @doc ~S"""
+  @doc """
   Returns the docs for the given module.
 
   When given a module name, it finds its BEAM code and reads the docs from it.
@@ -614,32 +500,10 @@ defmodule Code do
       which module definition starts and `doc` is the string
       attached to the module using the `@moduledoc` attribute
 
-    * `:callback_docs` - list of all docstrings attached to
-      `@callbacks` using the `@doc` attribute
-
-    * `:type_docs` - list of all docstrings attached to
-      `@type` callbacks using the `@typedoc` attribute
-
-    * `:all` - a keyword list with `:docs` and `:moduledoc`, `:callback_docs`,
-      and `:type_docs`.
-
-  If the module cannot be found, it returns `nil`.
-
-  ## Examples
-
-      # Get the module documentation
-      iex> {_line, text} = Code.get_docs(Atom, :moduledoc)
-      iex> String.split(text, "\n") |> Enum.at(0)
-      "Convenience functions for working with atoms."
-
-      # Module doesn't exist
-      iex> Code.get_docs(ModuleNotGood, :all)
-      nil
+    * `:all` - a keyword list with both `:docs` and `:moduledoc`
 
   """
-  @doc_kinds [:docs, :moduledoc, :callback_docs, :type_docs, :all]
-
-  def get_docs(module, kind) when is_atom(module) and kind in @doc_kinds do
+  def get_docs(module, kind) when is_atom(module) do
     case :code.get_object_code(module) do
       {_module, bin, _beam_path} ->
         do_get_docs(bin, kind)
@@ -648,8 +512,8 @@ defmodule Code do
     end
   end
 
-  def get_docs(binpath, kind) when is_binary(binpath) and kind in @doc_kinds do
-    do_get_docs(String.to_charlist(binpath), kind)
+  def get_docs(binpath, kind) when is_binary(binpath) do
+    do_get_docs(String.to_char_list(binpath), kind)
   end
 
   @docs_chunk 'ExDc'
@@ -670,7 +534,7 @@ defmodule Code do
   defp lookup_docs(_, _), do: nil
 
   defp do_lookup_docs(docs, :all), do: docs
-  defp do_lookup_docs(docs, kind),
+  defp do_lookup_docs(docs, kind) when kind in [:docs, :moduledoc],
     do: Keyword.get(docs, kind)
 
   ## Helpers

lib/elixir/lib/collectable.ex

@@ -13,7 +13,7 @@ defprotocol Collectable do
   The `Enumerable` protocol is useful to take values out of a collection.
   In order to support a wide range of values, the functions provided by
   the `Enumerable` protocol do not keep shape. For example, passing a
-  map to `Enum.map/2` always returns a list.
+  dictionary to `Enum.map/2` always returns a list.
 
   This design is intentional. `Enumerable` was designed to support infinite
   collections, resources and other structures with fixed shape. For example,
@@ -24,54 +24,23 @@ defprotocol Collectable do
   `Enumerable` protocol. `into/1` can be seen as the opposite of
   `Enumerable.reduce/3`. If `Enumerable` is about taking values out,
   `Collectable.into/1` is about collecting those values into a structure.
-
-  ## Examples
-
-  To show how to manually use the `Collectable` protocol, let's play with its
-  implementation for `MapSet`.
-
-      iex> {initial_acc, collector_fun} = Collectable.into(MapSet.new())
-      iex> updated_acc = Enum.reduce([1, 2, 3], initial_acc, fn elem, acc ->
-      ...>   collector_fun.(acc, {:cont, elem})
-      ...> end)
-      iex> collector_fun.(updated_acc, :done)
-      #MapSet<[1, 2, 3]>
-
-  To show how the protocol can be implemented, we can take again a look at the
-  implementation for `MapSet`. In this implementation "collecting" elements
-  simply means inserting them in the set through `MapSet.put/2`.
-
-      defimpl Collectable do
-        def into(original) do
-          collector_fun = fn
-            set, {:cont, elem} -> MapSet.put(set, elem)
-            set, :done -> set
-            _set, :halt -> :ok
-          end
-
-          {original, collector_fun}
-        end
-      end
-
   """
 
   @type command :: {:cont, term} | :done | :halt
 
   @doc """
-  Returns an initial accumulator and a "collector" function.
+  Returns a function that collects values alongside
+  the initial accumulation value.
 
-  The returned function receives a term and a command and injects the term into
-  the collectable on every `{:cont, term}` command.
+  The returned function receives a collectable and injects a given
+  value into it for every `{:cont, term}` instruction.
 
-  `:done` is passed as a command when no further values will be injected. This
-  is useful when there's a need to close resources or normalizing values. A
-  collectable must be returned when the command is `:done`.
+  `:done` is passed when no further values will be injected, useful
+  for closing resources and normalizing values. A collectable must
+  be returned on `:done`.
 
-  If injection is suddenly interrupted, `:halt` is passed and the function
-  can return any value as it won't be used.
-
-  For examples on how to use the `Collectable` protocol and `into/1` see the
-  module documentation.
+  If injection is suddenly interrupted, `:halt` is passed and it can
+  return any value, as it won't be used.
   """
   @spec into(t) :: {term, (term, command -> t | term)}
   def into(collectable)
@@ -80,7 +49,7 @@ end
 defimpl Collectable, for: List do
   def into(original) do
     {[], fn
-      list, {:cont, x} -> [x | list]
+      list, {:cont, x} -> [x|list]
       list, :done -> original ++ :lists.reverse(list)
       _, :halt -> :ok
     end}
@@ -90,7 +59,7 @@ end
 defimpl Collectable, for: BitString do
   def into(original) do
     {original, fn
-      acc, {:cont, x} when is_bitstring(x) -> [acc | x]
+      acc, {:cont, x} when is_bitstring(x) -> [acc|x]
       acc, :done -> IO.iodata_to_binary(acc)
       _, :halt -> :ok
     end}

lib/elixir/lib/dict.ex

@@ -1,26 +1,139 @@
 defmodule Dict do
   @moduledoc ~S"""
-  WARNING: this module is deprecated.
+  This module specifies the Dict API expected to be
+  implemented by different dictionaries. It also provides
+  functions that redirect to the underlying Dict, allowing
+  a developer to work with different Dict implementations
+  using one API.
 
-  If you need a general dictionary, use the `Map` module.
-  If you need to manipulate keyword lists, use `Keyword`.
+  To create a new dict, use the `new` functions defined
+  by each dict type:
+
+      HashDict.new  #=> creates an empty HashDict
+
+  In the examples below, `dict_impl` means a specific
+  `Dict` implementation, for example `HashDict` or `Map`.
+
+  ## Protocols
+
+  Besides implementing the functions in this module, all
+  dictionaries are required to implement the `Access`
+  protocol:
+
+      iex> dict = dict_impl.new
+      iex> dict = Dict.put(dict, :hello, :world)
+      iex> dict[:hello]
+      :world
+
+  As well as the `Enumerable` and `Collectable` protocols.
+
+  ## Match
+
+  Dictionaries are required to implement all operations
+  using the match (`===`) operator.
+
+  ## Default implementation
+
+  Default implementations for some functions in the `Dict` module
+  are provided via `use Dict`.
+
+  For example:
+
+      defmodule MyDict do
+        use Dict
+
+        # implement required functions (see below)
+        # override default implementations if optimization
+        # is needed
+      end
+
+  The client module must contain the following functions:
+
+    * `delete/2`
+    * `fetch/2`
+    * `put/3`
+    * `reduce/3`
+    * `size/1`
+
+  All functions, except `reduce/3`, are required by the Dict behaviour.
+  `reduce/3` must be implemtented as per the Enumerable protocol.
+
+  Based on these functions, `Dict` generates default implementations
+  for the following functions:
+
+    * `drop/2`
+    * `equal?/2`
+    * `fetch!/2`
+    * `get/2`
+    * `get/3`
+    * `has_key?/2`
+    * `keys/1`
+    * `merge/2`
+    * `merge/3`
+    * `pop/2`
+    * `pop/3`
+    * `put_new/3`
+    * `split/2`
+    * `take/2`
+    * `to_list/1`
+    * `update/4`
+    * `update!/3`
+    * `values/1`
+
+  All of these functions are defined as overridable, so you can provide
+  your own implementation if needed.
+
+  Note you can also test your custom module via `Dict`'s doctests:
+
+      defmodule MyDict do
+        # ...
+      end
+
+      defmodule MyTests do
+        use ExUnit.Case
+        doctest Dict
+        defp dict_impl, do: MyDict
+      end
 
-  To convert maps into keywords and vice-versa, use the
-  `new` function in the respective modules.
   """
 
+  use Behaviour
+
   @type key :: any
   @type value :: any
   @type t :: list | map
 
-  # TODO: Remove by 2.0
-  # (hard-deprecated in elixir_dispatch)
+  defcallback new :: t
+  defcallback delete(t, key) :: t
+  defcallback drop(t, Enum.t) :: t
+  defcallback equal?(t, t) :: boolean
+  defcallback get(t, key) :: value
+  defcallback get(t, key, value) :: value
+  defcallback fetch(t, key) :: {:ok, value} | :error
+  defcallback fetch!(t, key) :: value | no_return
+  defcallback has_key?(t, key) :: boolean
+  defcallback keys(t) :: [key]
+  defcallback merge(t, t) :: t
+  defcallback merge(t, t, (key, value, value -> value)) :: t
+  defcallback pop(t, key) :: {value, t}
+  defcallback pop(t, key, value) :: {value, t}
+  defcallback put(t, key, value) :: t
+  defcallback put_new(t, key, value) :: t
+  defcallback size(t) :: non_neg_integer()
+  defcallback split(t, Enum.t) :: {t, t}
+  defcallback take(t, Enum.t) :: t
+  defcallback to_list(t) :: list()
+  defcallback update(t, key, value, (value -> value)) :: t
+  defcallback update!(t, key, (value -> value)) :: t | no_return
+  defcallback values(t) :: list(value)
 
   defmacro __using__(_) do
     # Use this import to guarantee proper code expansion
     import Kernel, except: [size: 1]
 
     quote do
+      @behaviour Dict
+
       def get(dict, key, default \\ nil) do
         case fetch(dict, key) do
           {:ok, value} -> value
@@ -28,19 +141,6 @@ defmodule Dict do
         end
       end
 
-      def get_lazy(dict, key, fun) when is_function(fun, 0) do
-        case fetch(dict, key) do
-          {:ok, value} -> value
-          :error -> fun.()
-        end
-      end
-
-      def get_and_update(dict, key, fun) do
-        current_value = get(dict, key)
-        {get, new_value} = fun.(current_value)
-        {get, put(dict, key, new_value)}
-      end
-
       def fetch!(dict, key) do
         case fetch(dict, key) do
           {:ok, value} -> value
@@ -59,19 +159,12 @@ defmodule Dict do
         end
       end
 
-      def put_new_lazy(dict, key, fun) when is_function(fun, 0) do
-        case has_key?(dict, key) do
-          true  -> dict
-          false -> put(dict, key, fun.())
-        end
-      end
-
       def drop(dict, keys) do
         Enum.reduce(keys, dict, &delete(&2, &1))
       end
 
       def take(dict, keys) do
-        Enum.reduce(keys, new(), fn key, acc ->
+        Enum.reduce(keys, new, fn key, acc ->
           case fetch(dict, key) do
             {:ok, value} -> put(acc, key, value)
             :error -> acc
@@ -81,19 +174,19 @@ defmodule Dict do
 
       def to_list(dict) do
         reduce(dict, {:cont, []}, fn
-          kv, acc -> {:cont, [kv | acc]}
+          kv, acc -> {:cont, [kv|acc]}
         end) |> elem(1) |> :lists.reverse
       end
 
       def keys(dict) do
         reduce(dict, {:cont, []}, fn
-          {k, _}, acc -> {:cont, [k | acc]}
+          {k, _}, acc -> {:cont, [k|acc]}
         end) |> elem(1) |> :lists.reverse
       end
 
       def values(dict) do
         reduce(dict, {:cont, []}, fn
-          {_, v}, acc -> {:cont, [v | acc]}
+          {_, v}, acc -> {:cont, [v|acc]}
         end) |> elem(1) |> :lists.reverse
       end
 
@@ -155,17 +248,8 @@ defmodule Dict do
         end
       end
 
-      def pop_lazy(dict, key, fun) when is_function(fun, 0) do
-        case fetch(dict, key) do
-          {:ok, value} ->
-            {value, delete(dict, key)}
-          :error ->
-            {fun.(), dict}
-        end
-      end
-
       def split(dict, keys) do
-        Enum.reduce(keys, {new(), dict}, fn key, {inc, exc} = acc ->
+        Enum.reduce(keys, {new, dict}, fn key, {inc, exc} = acc ->
           case fetch(exc, key) do
             {:ok, value} ->
               {put(inc, key, value), delete(exc, key)}
@@ -178,11 +262,11 @@ defmodule Dict do
       defoverridable merge: 2, merge: 3, equal?: 2, to_list: 1, keys: 1,
                      values: 1, take: 2, drop: 2, get: 2, get: 3, fetch!: 2,
                      has_key?: 2, put_new: 3, pop: 2, pop: 3, split: 2,
-                     update: 4, update!: 3, get_and_update: 3, get_lazy: 3,
-                     pop_lazy: 3, put_new_lazy: 3
+                     update: 4, update!: 3
     end
   end
 
+
   defmacrop target(dict) do
     quote do
       case unquote(dict) do
@@ -198,141 +282,380 @@ defmodule Dict do
     end
   end
 
+  @doc """
+  Returns a list of all keys in `dict`.
+  The keys are not guaranteed to be in any order.
+
+  ## Examples
+
+      iex> dict = Enum.into([a: 1, b: 2], dict_impl.new)
+      iex> Enum.sort(Dict.keys(dict))
+      [:a,:b]
+
+  """
   @spec keys(t) :: [key]
   def keys(dict) do
     target(dict).keys(dict)
   end
 
+  @doc """
+  Returns a list of all values in `dict`.
+  The values are not guaranteed to be in any order.
+
+  ## Examples
+
+      iex> dict = Enum.into([a: 1, b: 2], dict_impl.new)
+      iex> Enum.sort(Dict.values(dict))
+      [1,2]
+
+  """
   @spec values(t) :: [value]
   def values(dict) do
     target(dict).values(dict)
   end
 
+  @doc """
+  Returns the number of elements in `dict`.
+
+  ## Examples
+
+      iex> dict = Enum.into([a: 1, b: 2], dict_impl.new)
+      iex> Dict.size(dict)
+      2
+
+  """
   @spec size(t) :: non_neg_integer
   def size(dict) do
     target(dict).size(dict)
   end
 
+  @doc """
+  Returns whether the given `key` exists in the given `dict`.
+
+  ## Examples
+
+      iex> dict = Enum.into([a: 1], dict_impl.new)
+      iex> Dict.has_key?(dict, :a)
+      true
+      iex> Dict.has_key?(dict, :b)
+      false
+
+  """
   @spec has_key?(t, key) :: boolean
   def has_key?(dict, key) do
     target(dict).has_key?(dict, key)
   end
 
+  @doc """
+  Returns the value associated with `key` in `dict`. If `dict` does not
+  contain `key`, returns `default` (or `nil` if not provided).
+
+  ## Examples
+
+      iex> dict = Enum.into([a: 1], dict_impl.new)
+      iex> Dict.get(dict, :a)
+      1
+      iex> Dict.get(dict, :b)
+      nil
+      iex> Dict.get(dict, :b, 3)
+      3
+  """
   @spec get(t, key, value) :: value
   def get(dict, key, default \\ nil) do
     target(dict).get(dict, key, default)
   end
 
-  @spec get_lazy(t, key, (() -> value)) :: value
-  def get_lazy(dict, key, fun) do
-    target(dict).get_lazy(dict, key, fun)
-  end
+  @doc """
+  Returns `{:ok, value}` associated with `key` in `dict`.
+  If `dict` does not contain `key`, returns `:error`.
 
-  @spec get_and_update(t, key, (value -> {value, value})) :: {value, t}
-  def get_and_update(dict, key, fun) do
-    target(dict).get_and_update(dict, key, fun)
-  end
+  ## Examples
 
+      iex> dict = Enum.into([a: 1], dict_impl.new)
+      iex> Dict.fetch(dict, :a)
+      {:ok, 1}
+      iex> Dict.fetch(dict, :b)
+      :error
+
+  """
   @spec fetch(t, key) :: value
   def fetch(dict, key) do
     target(dict).fetch(dict, key)
   end
 
+  @doc """
+  Returns the value associated with `key` in `dict`. If `dict` does not
+  contain `key`, it raises `KeyError`.
+
+  ## Examples
+
+      iex> dict = Enum.into([a: 1], dict_impl.new)
+      iex> Dict.fetch!(dict, :a)
+      1
+
+  """
   @spec fetch!(t, key) :: value | no_return
   def fetch!(dict, key) do
     target(dict).fetch!(dict, key)
   end
 
+  @doc """
+  Stores the given `value` under `key` in `dict`.
+  If `dict` already has `key`, the stored value is replaced by the new one.
+
+  ## Examples
+
+      iex> dict = Enum.into([a: 1, b: 2], dict_impl.new)
+      iex> dict = Dict.put(dict, :a, 3)
+      iex> Dict.get(dict, :a)
+      3
+
+  """
   @spec put(t, key, value) :: t
   def put(dict, key, val) do
     target(dict).put(dict, key, val)
   end
 
+  @doc """
+  Puts the given `value` under `key` in `dict` unless `key` already exists.
+
+  ## Examples
+
+      iex> dict = Enum.into([a: 1, b: 2], dict_impl.new)
+      iex> dict = Dict.put_new(dict, :a, 3)
+      iex> Dict.get(dict, :a)
+      1
+
+  """
   @spec put_new(t, key, value) :: t
   def put_new(dict, key, val) do
     target(dict).put_new(dict, key, val)
   end
 
-  @spec put_new_lazy(t, key, (() -> value)) :: t
-  def put_new_lazy(dict, key, fun) do
-    target(dict).put_new_lazy(dict, key, fun)
-  end
+  @doc """
+  Removes the entry stored under the given `key` from `dict`.
+  If `dict` does not contain `key`, returns the dictionary unchanged.
 
+  ## Examples
+
+      iex> dict = Enum.into([a: 1, b: 2], dict_impl.new)
+      iex> dict = Dict.delete(dict, :a)
+      iex> Dict.get(dict, :a)
+      nil
+
+      iex> dict = Enum.into([b: 2], dict_impl.new)
+      iex> Dict.delete(dict, :a) == dict
+      true
+
+  """
   @spec delete(t, key) :: t
   def delete(dict, key) do
     target(dict).delete(dict, key)
   end
 
-  @spec merge(t, t) :: t
-  def merge(dict1, dict2) do
-    target1 = target(dict1)
-    target2 = target(dict2)
+  @doc """
+  Merges the dict `dict2` into dict `dict1`.
 
-    if target1 == target2 do
-      target1.merge(dict1, dict2)
-    else
-      do_merge(target1, dict1, dict2, fn(_k, _v1, v2) -> v2 end)
-    end
-  end
+  If one of the `dict2` entries already exists in `dict1`, the
+  functions in entries in `dict2` have higher precedence unless a
+  function is given to resolve conflicts.
 
+  Notice this function is polymorphic as it merges dicts of any
+  type. Each dict implementation also provides a `merge` function,
+  but they can only merge dicts of the same type.
+
+  ## Examples
+
+      iex> dict1 = Enum.into([a: 1, b: 2], dict_impl.new)
+      iex> dict2 = Enum.into([a: 3, d: 4], dict_impl.new)
+      iex> dict = Dict.merge(dict1, dict2)
+      iex> [a: Dict.get(dict, :a), b: Dict.get(dict, :b), d: Dict.get(dict, :d)]
+      [a: 3, b: 2, d: 4]
+
+      iex> dict1 = Enum.into([a: 1, b: 2], dict_impl.new)
+      iex> dict2 = Enum.into([a: 3, d: 4], dict_impl.new)
+      iex> dict = Dict.merge(dict1, dict2, fn(_k, v1, v2) ->
+      ...>   v1 + v2
+      ...> end)
+      iex> [a: Dict.get(dict, :a), b: Dict.get(dict, :b), d: Dict.get(dict, :d)]
+      [a: 4, b: 2, d: 4]
+
+  """
   @spec merge(t, t, (key, value, value -> value)) :: t
-  def merge(dict1, dict2, fun) do
+  def merge(dict1, dict2, fun \\ fn(_k, _v1, v2) -> v2 end) do
     target1 = target(dict1)
     target2 = target(dict2)
 
     if target1 == target2 do
       target1.merge(dict1, dict2, fun)
     else
-      do_merge(target1, dict1, dict2, fun)
+      Enumerable.reduce(dict2, {:cont, dict1}, fn({k, v}, acc) ->
+        {:cont, target1.update(acc, k, v, fn(other) -> fun.(k, other, v) end)}
+      end) |> elem(1)
     end
   end
 
-  defp do_merge(target1, dict1, dict2, fun) do
-    Enumerable.reduce(dict2, {:cont, dict1}, fn({k, v}, acc) ->
-      {:cont, target1.update(acc, k, v, fn(other) -> fun.(k, other, v) end)}
-    end) |> elem(1)
-  end
+  @doc """
+  Returns the value associated with `key` in `dict` as
+  well as the `dict` without `key`.
 
+  ## Examples
+
+      iex> dict = Enum.into([a: 1], dict_impl.new)
+      iex> {v, dict} = Dict.pop dict, :a
+      iex> {v, Enum.sort(dict)}
+      {1,[]}
+
+      iex> dict = Enum.into([a: 1], dict_impl.new)
+      iex> {v, dict} = Dict.pop dict, :b
+      iex> {v, Enum.sort(dict)}
+      {nil,[a: 1]}
+
+      iex> dict = Enum.into([a: 1], dict_impl.new)
+      iex> {v, dict} = Dict.pop dict, :b, 3
+      iex> {v, Enum.sort(dict)}
+      {3,[a: 1]}
+
+  """
   @spec pop(t, key, value) :: {value, t}
   def pop(dict, key, default \\ nil) do
     target(dict).pop(dict, key, default)
   end
 
-  @spec pop_lazy(t, key, (() -> value)) :: {value, t}
-  def pop_lazy(dict, key, fun) do
-    target(dict).pop_lazy(dict, key, fun)
-  end
+  @doc """
+  Update a value in `dict` by calling `fun` on the value to get a new
+  value. An exception is generated if `key` is not present in the dict.
 
+  ## Examples
+
+      iex> dict = Enum.into([a: 1, b: 2], dict_impl.new)
+      iex> dict = Dict.update!(dict, :a, fn(val) -> -val end)
+      iex> Dict.get(dict, :a)
+      -1
+
+  """
   @spec update!(t, key, (value -> value)) :: t
   def update!(dict, key, fun) do
     target(dict).update!(dict, key, fun)
   end
 
+  @doc """
+  Update a value in `dict` by calling `fun` on the value to get a new value. If
+  `key` is not present in `dict` then `initial` will be stored as the first
+  value.
+
+  ## Examples
+
+      iex> dict = Enum.into([a: 1, b: 2], dict_impl.new)
+      iex> dict = Dict.update(dict, :c, 3, fn(val) -> -val end)
+      iex> Dict.get(dict, :c)
+      3
+
+  """
   @spec update(t, key, value, (value -> value)) :: t
   def update(dict, key, initial, fun) do
     target(dict).update(dict, key, initial, fun)
   end
 
+  @doc """
+  Returns a tuple of two dicts, where the first dict contains only
+  entries from `dict` with keys in `keys`, and the second dict
+  contains only entries from `dict` with keys not in `keys`
+
+  Any non-member keys are ignored.
+
+  ## Examples
+
+      iex> dict = Enum.into([a: 1, b: 2, c: 3, d: 4], dict_impl.new)
+      iex> {dict1, dict2} = Dict.split(dict, [:a, :c, :e])
+      iex> {Dict.to_list(dict1) |> Enum.sort, Dict.to_list(dict2) |> Enum.sort}
+      {[a: 1, c: 3], [b: 2, d: 4]}
+
+      iex> dict = Enum.into([], dict_impl.new)
+      iex> {dict1, dict2} = Dict.split(dict, [:a, :c])
+      iex> {Dict.to_list(dict1), Dict.to_list(dict2)}
+      {[], []}
+
+      iex> dict = Enum.into([a: 1, b: 2], dict_impl.new)
+      iex> {dict1, dict2} = Dict.split(dict, [:a, :b, :c])
+      iex> {Dict.to_list(dict1) |> Enum.sort, Dict.to_list(dict2)}
+      {[a: 1, b: 2], []}
+
+  """
   @spec split(t, [key]) :: {t, t}
   def split(dict, keys) do
     target(dict).split(dict, keys)
   end
 
+  @doc """
+  Returns a new dict where the given `keys` are removed from `dict`.
+  Any non-member keys are ignored.
+
+  ## Examples
+
+      iex> dict = Enum.into([a: 1, b: 2], dict_impl.new)
+      iex> dict = Dict.drop(dict, [:a, :c, :d])
+      iex> Dict.to_list(dict)
+      [b: 2]
+
+      iex> dict = Enum.into([a: 1, b: 2], dict_impl.new)
+      iex> dict = Dict.drop(dict, [:c, :d])
+      iex> Dict.to_list(dict) |> Enum.sort
+      [a: 1, b: 2]
+
+  """
   @spec drop(t, [key]) :: t
   def drop(dict, keys) do
     target(dict).drop(dict, keys)
   end
 
+  @doc """
+  Returns a new dict where only the keys in `keys` from `dict` are included.
+
+  Any non-member keys are ignored.
+
+  ## Examples
+
+      iex> dict = Enum.into([a: 1, b: 2], dict_impl.new)
+      iex> dict = Dict.take(dict, [:a, :c, :d])
+      iex> Dict.to_list(dict)
+      [a: 1]
+      iex> dict = Dict.take(dict, [:c, :d])
+      iex> Dict.to_list(dict)
+      []
+
+  """
   @spec take(t, [key]) :: t
   def take(dict, keys) do
     target(dict).take(dict, keys)
   end
 
+  @doc false
   @spec empty(t) :: t
   def empty(dict) do
     target(dict).empty(dict)
   end
 
+  @doc """
+  Check if two dicts are equal using `===`.
+
+  Notice this function is polymorphic as it compares dicts of any
+  type. Each dict implementation also provides an `equal?` function,
+  but they can only compare dicts of the same type.
+
+  ## Examples
+
+      iex> dict1 = Enum.into([a: 2, b: 3, f: 5, c: 123], dict_impl.new)
+      iex> dict2 = [a: 2, b: 3, f: 5, c: 123]
+      iex> Dict.equal?(dict1, dict2)
+      true
+
+      iex> dict1 = Enum.into([a: 2, b: 3, f: 5, c: 123], dict_impl.new)
+      iex> dict2 = []
+      iex> Dict.equal?(dict1, dict2)
+      false
+
+  """
   @spec equal?(t, t) :: boolean
   def equal?(dict1, dict2) do
     target1 = target(dict1)
@@ -346,7 +669,7 @@ defmodule Dict do
         Enumerable.reduce(dict2, {:cont, true}, fn({k, v}, _acc) ->
           case target1.fetch(dict1, k) do
             {:ok, ^v} -> {:cont, true}
-            _         -> {:halt, false}
+            _           -> {:halt, false}
           end
         end) |> elem(1)
 
@@ -355,12 +678,15 @@ defmodule Dict do
     end
   end
 
+  @doc """
+  Returns a list of key-value pairs stored in `dict`.
+  No particular order is enforced.
+  """
   @spec to_list(t) :: list
   def to_list(dict) do
     target(dict).to_list(dict)
   end
 
-  @spec unsupported_dict(t) :: no_return
   defp unsupported_dict(dict) do
     raise ArgumentError, "unsupported dict: #{inspect dict}"
   end

lib/elixir/lib/file/stat.ex

@@ -2,11 +2,11 @@ require Record
 
 defmodule File.Stat do
   @moduledoc """
-  A struct that holds file information.
+  A struct responsible to hold file information.
 
   In Erlang, this struct is represented by a `:file_info` record.
   Therefore this module also provides functions for converting
-  between the Erlang record and the Elixir struct.
+  in between the Erlang record and the Elixir struct.
 
   Its fields are:
 
@@ -32,7 +32,7 @@ defmodule File.Stat do
       systems which have no concept of links.
 
     * `major_device` - identifies the file system where the file is located.
-      In Windows, the number indicates a drive as follows: 0 means A:, 1 means
+      In windows, the number indicates a drive as follows: 0 means A:, 1 means
       B:, and so on.
 
     * `minor_device` - only valid for character devices on Unix. In all other
@@ -41,15 +41,14 @@ defmodule File.Stat do
     * `inode` - gives the inode number. On non-Unix file systems, this field
       will be zero.
 
-    * `uid` - indicates the owner of the file. Will be zero for non-Unix file
-      systems.
+    * `uid` - indicates the owner of the file.
 
-    * `gid` - indicates the group that owns the file. Will be zero for
-      non-Unix file systems.
+    * `gid` - gives the group that the owner of the file belongs to. Will be
+      zero for non-Unix file systems.
 
   The time type returned in `atime`, `mtime`, and `ctime` is dependent on the
   time type set in options. `{:time, type}` where type can be `:local`,
-  `:universal`, or `:posix`. Default is `:universal`.
+  `:universal`, or `:posix`. Default is `:local`.
   """
 
   record = Record.extract(:file_info, from_lib: "kernel/include/file.hrl")
@@ -70,7 +69,6 @@ defmodule File.Stat do
   @doc """
   Converts a `:file_info` record into a `File.Stat`.
   """
-  def from_record(file_info)
   def from_record({:file_info, unquote_splicing(vals)}) do
     %File.Stat{unquote_splicing(pairs)}
   end

lib/elixir/lib/file/stream.ex

@@ -20,25 +20,28 @@ defmodule File.Stream do
     raw = :lists.keyfind(:encoding, 1, modes) == false
 
     modes =
-      case raw do
-        true ->
-          if :lists.keyfind(:read_ahead, 1, modes) == {:read_ahead, false} do
-            [:raw | modes]
-          else
-            [:raw, :read_ahead | modes]
-          end
-        false ->
-          modes
+      if raw do
+        if :lists.keyfind(:read_ahead, 1, modes) == {:read_ahead, false} do
+          [:raw|modes]
+        else
+          [:raw, :read_ahead|modes]
+        end
+      else
+        modes
       end
 
     %File.Stream{path: path, modes: modes, raw: raw, line_or_bytes: line_or_bytes}
   end
 
   defimpl Collectable do
-    def into(%{path: path, modes: modes, raw: raw} = stream) do
-      modes = for mode <- modes, mode not in [:read], do: mode
+    def empty(stream) do
+      stream
+    end
 
-      case :file.open(path, [:write | modes]) do
+    def into(%{path: path, modes: modes, raw: raw} = stream) do
+      modes = for mode <- modes, not mode in [:read], do: mode
+
+      case :file.open(path, [:write|modes]) do
         {:ok, device} ->
           {:ok, into(device, stream, raw)}
         {:error, reason} ->
@@ -67,14 +70,13 @@ defmodule File.Stream do
   end
 
   defimpl Enumerable do
-    @read_ahead_size 64 * 1024
-
     def reduce(%{path: path, modes: modes, line_or_bytes: line_or_bytes, raw: raw}, acc, fun) do
+      modes = for mode <- modes, not mode in [:write, :append], do: mode
+
       start_fun =
         fn ->
-          case :file.open(path, read_modes(modes)) do
-            {:ok, device} ->
-              if :trim_bom in modes, do: trim_bom(device), else: device
+          case :file.open(path, modes) do
+            {:ok, device}    -> device
             {:error, reason} ->
               raise File.Error, reason: reason, action: "stream", path: path
           end
@@ -89,70 +91,12 @@ defmodule File.Stream do
       Stream.resource(start_fun, next_fun, &:file.close/1).(acc, fun)
     end
 
-    def count(%{path: path, modes: modes, line_or_bytes: :line} = stream) do
-      pattern = :binary.compile_pattern("\n")
-      counter = &count_lines(&1, path, pattern, read_function(stream), 0)
-
-      case File.open(path, read_modes(modes), counter) do
-        {:ok, count} ->
-          {:ok, count}
-        {:error, reason} ->
-          raise File.Error, reason: reason, action: "stream", path: path
-      end
-    end
-
-    def count(%{path: path, line_or_bytes: bytes}) do
-      case File.stat(path) do
-        {:ok, %{size: 0}} ->
-          {:error, __MODULE__}
-        {:ok, %{size: size}} ->
-          {:ok, div(size, bytes) + if(rem(size, bytes) == 0, do: 0, else: 1)}
-        {:error, reason} ->
-          raise File.Error, reason: reason, action: "stream", path: path
-      end
+    def count(_stream) do
+      {:error, __MODULE__}
     end
 
     def member?(_stream, _term) do
       {:error, __MODULE__}
     end
-
-    defp trim_bom(device) do
-      header = IO.binread(device, 4)
-      {:ok, _new_pos} = :file.position(device, bom_length(header))
-      device
-    end
-
-    defp bom_length(<<239, 187, 191, _rest::binary>>),
-      do: 3
-    defp bom_length(<<254, 255, _rest::binary>>),
-      do: 2
-    defp bom_length(<<255, 254, _rest::binary>>),
-      do: 2
-    defp bom_length(<<0, 0, 254, 255, _rest::binary>>),
-      do: 4
-    defp bom_length(<<254, 255, 0, 0, _rest::binary>>),
-      do: 4
-    defp bom_length(_binary),
-      do: 0
-
-    defp read_modes(modes) do
-      for mode <- modes, mode not in [:write, :append, :trim_bom], do: mode
-    end
-
-    defp count_lines(device, path, pattern, read, count) do
-      case read.(device) do
-        data when is_binary(data) ->
-          count_lines(device, path, pattern, read, count + count_lines(data, pattern))
-        :eof ->
-          count
-        {:error, reason} ->
-          raise File.Error, reason: reason, action: "stream", path: path
-      end
-    end
-
-    defp count_lines(data, pattern), do: length(:binary.matches(data, pattern))
-
-    defp read_function(%{raw: true}), do: &IO.binread(&1, @read_ahead_size)
-    defp read_function(%{raw: false}), do: &IO.read(&1, @read_ahead_size)
   end
 end

lib/elixir/lib/float.ex

@@ -2,36 +2,25 @@ import Kernel, except: [round: 1]
 
 defmodule Float do
   @moduledoc """
-  Functions for working with floating-point numbers.
+  Functions for working with floating point numbers.
   """
 
-  import Bitwise
-
-  @power_of_2_to_52 4503599627370496
-  @precision_range 0..15
-  @type precision_range :: 0..15
-
   @doc """
   Parses a binary into a float.
 
-  If successful, returns a tuple in the form of `{float, remainder_of_binary}`;
-  when the binary cannot be coerced into a valid float, the atom `:error` is
-  returned.
-
-  If the size of float exceeds the maximum size of `1.7976931348623157e+308`,
-  the `ArgumentError` exception is raised.
-
-  If you want to convert a string-formatted float directly to a float,
-  `String.to_float/1` can be used instead.
+  If successful, returns a tuple of the form `{float, remainder_of_binary}`.
+  Otherwise `:error`.
 
   ## Examples
 
       iex> Float.parse("34")
-      {34.0, ""}
+      {34.0,""}
+
       iex> Float.parse("34.25")
-      {34.25, ""}
+      {34.25,""}
+
       iex> Float.parse("56.5xyz")
-      {56.5, "xyz"}
+      {56.5,"xyz"}
 
       iex> Float.parse("pi")
       :error
@@ -39,410 +28,249 @@ defmodule Float do
   """
   @spec parse(binary) :: {float, binary} | :error
   def parse("-" <> binary) do
-    case parse_unsigned(binary) do
+    case parse_unsign(binary) do
       :error -> :error
       {number, remainder} -> {-number, remainder}
     end
   end
 
-  def parse("+" <> binary) do
-    parse_unsigned(binary)
-  end
-
   def parse(binary) do
-    parse_unsigned(binary)
+    parse_unsign(binary)
   end
 
-  defp parse_unsigned(<<digit, rest::binary>>) when digit in ?0..?9, do:
-    parse_unsigned(rest, false, false, <<digit>>)
+  defp parse_unsign("-" <> _), do: :error
+  defp parse_unsign(binary) when is_binary(binary) do
+    case Integer.parse binary do
+      :error -> :error
+      {integer_part, after_integer} -> parse_unsign after_integer, integer_part
+    end
+  end
 
-  defp parse_unsigned(binary) when is_binary(binary), do:
-    :error
+  # Dot followed by digit is required afterwards or we are done
+  defp parse_unsign(<< ?., char, rest :: binary >>, int) when char in ?0..?9 do
+    parse_unsign(rest, char - ?0, 1, int)
+  end
 
-  defp parse_unsigned(<<digit, rest::binary>>, dot?, e?, acc) when digit in ?0..?9, do:
-    parse_unsigned(rest, dot?, e?, <<acc::binary, digit>>)
+  defp parse_unsign(rest, int) do
+    {:erlang.float(int), rest}
+  end
 
-  defp parse_unsigned(<<?., digit, rest::binary>>, false, false, acc) when digit in ?0..?9, do:
-    parse_unsigned(rest, true, false, <<acc::binary, ?., digit>>)
+  # Handle decimal points
+  defp parse_unsign(<< char, rest :: binary >>, float, decimal, int) when char in ?0..?9 do
+    parse_unsign rest, 10 * float + (char - ?0), decimal + 1, int
+  end
 
-  defp parse_unsigned(<<exp_marker, digit, rest::binary>>, dot?, false, acc) when exp_marker in 'eE' and  digit in ?0..?9, do:
-    parse_unsigned(rest, true, true, <<add_dot(acc, dot?)::binary, ?e, digit>>)
+  defp parse_unsign(<< ?e, after_e :: binary >>, float, decimal, int) do
+    case Integer.parse after_e do
+      :error ->
+        # Note we rebuild the binary here instead of breaking it apart at
+        # the function clause because the current approach copies a binary
+        # just on this branch. If we broke it apart in the function clause,
+        # the copy would happen when calling Integer.parse/1.
+        {floatify(int, float, decimal), << ?e, after_e :: binary >>}
+      {exponential, after_exponential} ->
+        {floatify(int, float, decimal, exponential), after_exponential}
+    end
+  end
 
-  defp parse_unsigned(<<exp_marker, sign, digit, rest::binary>>, dot?, false, acc) when exp_marker in 'eE' and sign in '-+' and digit in ?0..?9, do:
-    parse_unsigned(rest, true, true, <<add_dot(acc, dot?)::binary, ?e, sign, digit>>)
+  defp parse_unsign(bitstring, float, decimal, int) do
+    {floatify(int, float, decimal), bitstring}
+  end
 
-  defp parse_unsigned(rest, dot?, _e?, acc), do:
-    {:erlang.binary_to_float(add_dot(acc, dot?)), rest}
+  defp floatify(int, float, decimal, exponential \\ 0) do
+    multiplier = if int < 0, do: -1.0, else: 1.0
 
-  defp add_dot(acc, true),  do: acc
-  defp add_dot(acc, false), do: acc <> ".0"
+    # Try to ensure the minimum amount of rounding errors
+    result = multiplier * (abs(int) * :math.pow(10, decimal) + float) * :math.pow(10, exponential - decimal)
+
+    # Try avoiding stuff like this:
+    # iex(1)> 0.0001 * 75
+    # 0.007500000000000001
+    # Due to IEEE 754 floating point standard
+    # http://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html
+
+    final_decimal_places = decimal - exponential
+    if final_decimal_places > 0 do
+      decimal_power_round = :math.pow(10,  final_decimal_places)
+      trunc(result * decimal_power_round) / decimal_power_round
+    else
+      result
+    end
+  end
 
   @doc """
   Rounds a float to the largest integer less than or equal to `num`.
 
-  `floor/2` also accepts a precision to round a floating-point value down
+  Floor also accepts a precision to round a floating point value down
   to an arbitrary number of fractional digits (between 0 and 15).
-  The operation is performed on the binary floating point, without a
-  conversion to decimal.
 
-  The behaviour of `floor/2` for floats can be surprising. For example:
-
-      iex> Float.floor(12.52, 2)
-      12.51
-
-  One may have expected it to floor to 12.52. This is not a bug.
-  Most decimal fractions cannot be represented as a binary floating point
-  and therefore the number above is internally represented as 12.51999999,
-  which explains the behaviour above.
-
-  This function always returns a float. `Kernel.trunc/1` may be used instead to
+  This function always returns floats. One may use `Kernel.trunc/1` to
   truncate the result to an integer afterwards.
 
   ## Examples
 
       iex> Float.floor(34.25)
       34.0
+
       iex> Float.floor(-56.5)
       -57.0
-      iex> Float.floor(34.259, 2)
+
+      iex> Float.floor(34.253, 2)
       34.25
 
   """
-  @spec floor(float, precision_range) :: float
-  def floor(number, precision \\ 0)
-
-  def floor(number, precision) when is_float(number) and precision in @precision_range do
-    round(number, precision, :floor)
-  end
-
-  def floor(number, precision) when is_float(number) do
-    raise ArgumentError, invalid_precision_message(precision)
+  @spec floor(float, 0..15) :: float
+  def floor(number, precision \\ 0) when is_float(number) and precision in 0..15 do
+    power     = power_of_10(precision)
+    number    = number * power
+    truncated = trunc(number)
+    variance  = if number - truncated < 0, do: -1.0, else: 0.0
+    (truncated + variance) / power
   end
 
   @doc """
-  Rounds a float to the smallest integer greater than or equal to `num`.
+  Rounds a float to the largest integer greater than or equal to `num`.
 
-  `ceil/2` also accepts a precision to round a floating-point value down
-  to an arbitrary number of fractional digits (between 0 and 15).
+  Ceil also accepts a precision to round a floating point value down to
+  an arbitrary number of fractional digits (between 0 and 15).
 
-  The operation is performed on the binary floating point, without a
-  conversion to decimal.
-
-  The behaviour of `ceil/2` for floats can be surprising. For example:
-
-      iex> Float.ceil(-12.52, 2)
-      -12.51
-
-  One may have expected it to ceil to -12.52. This is not a bug.
-  Most decimal fractions cannot be represented as a binary floating point
-  and therefore the number above is internally represented as -12.51999999,
-  which explains the behaviour above.
-
-  This function always returns floats. `Kernel.trunc/1` may be used instead to
+  This function always returns floats. One may use `Kernel.trunc/1` to
   truncate the result to an integer afterwards.
 
   ## Examples
 
       iex> Float.ceil(34.25)
       35.0
+
       iex> Float.ceil(-56.5)
       -56.0
-      iex> Float.ceil(34.251, 2)
+
+      iex> Float.ceil(34.253, 2)
       34.26
 
   """
-  @spec ceil(float, precision_range) :: float
-  def ceil(number, precision \\ 0)
-
-  def ceil(number, precision) when is_float(number) and precision in @precision_range do
-    round(number, precision, :ceil)
-  end
-
-  def ceil(number, precision) when is_float(number) do
-    raise ArgumentError, invalid_precision_message(precision)
+  @spec ceil(float, 0..15) :: float
+  def ceil(number, precision \\ 0) when is_float(number) and precision in 0..15 do
+    power     = power_of_10(precision)
+    number    = number * power
+    truncated = trunc(number)
+    variance  = if number - truncated > 0, do: 1.0, else: 0.0
+    (truncated + variance) / power
   end
 
   @doc """
-  Rounds a floating-point value to an arbitrary number of fractional
-  digits (between 0 and 15).
+  Rounds a floating point value to an arbitrary number of fractional digits
+  (between 0 and 15).
 
-  The rounding direction always ties to half up. The operation is
-  performed on the binary floating point, without a conversion to decimal.
-
-  This function only accepts floats and always returns a float. Use
-  `Kernel.round/1` if you want a function that accepts both floats
-  and integers and always returns an integer.
-
-  The behaviour of `round/2` for floats can be surprising. For example:
-
-      iex> Float.round(5.5675, 3)
-      5.567
-
-  One may have expected it to round to the half up 5.568. This is not a bug.
-  Most decimal fractions cannot be represented as a binary floating point
-  and therefore the number above is internally represented as 5.567499999,
-  which explains the behaviour above. If you want exact rounding for decimals,
-  you must use a decimal library. The behaviour above is also in accordance
-  to reference implementations, such as "Correctly Rounded Binary-Decimal and
-  Decimal-Binary Conversions" by David M. Gay.
+  This function only accepts floats and returns floats. Use `Kernel.round/1`
+  if you want a function that accepts both floats and integers and always
+  returns an integer.
 
   ## Examples
 
-      iex> Float.round(12.5)
-      13.0
       iex> Float.round(5.5674, 3)
       5.567
+
       iex> Float.round(5.5675, 3)
-      5.567
+      5.568
+
       iex> Float.round(-5.5674, 3)
       -5.567
-      iex> Float.round(-5.5675)
-      -6.0
-      iex> Float.round(12.341444444444441, 15)
-      12.341444444444441
+
+      iex> Float.round(-5.5675, 3)
+      -5.568
 
   """
-  @spec round(float, precision_range) :: float
-  # This implementation is slow since it relies on big integers.
-  # Faster implementations are available on more recent papers
-  # and could be implemented in the future.
-  def round(float, precision \\ 0)
-
-  def round(float, precision) when is_float(float) and precision in @precision_range do
-    round(float, precision, :half_up)
+  @spec round(float, 0..15) :: float
+  def round(number, precision \\ 0) when is_float(number) and precision in 0..15 do
+    power = power_of_10(precision)
+    Kernel.round(number * power) / power
   end
 
-  def round(number, precision) when is_float(number) do
-    raise ArgumentError, invalid_precision_message(precision)
-  end
-
-  defp round(float, precision, rounding) do
-    <<sign::1, exp::11, significant::52-bitstring>> = <<float::float>>
-    {num, count, _} = decompose(significant)
-    count = count - exp + 1023
-
-    cond do
-      count <= 0 or  # There is no decimal precision
-      (0 == exp and <<0::52>> == significant) -> #zero or minus zero
-        float
-
-      count >= 104 -> # Precision beyond 15 digits
-        case rounding do
-          :ceil when sign === 0 -> 1 / power_of_10(precision)
-          :floor when sign === 1 -> -1 / power_of_10(precision)
-          _ -> 0.0
-        end
-
-      count <= precision -> # We are asking more precision than we have
-        float
-
-      true ->
-        # Difference in precision between float and asked precision
-        # We subtract 1 because we need to calculate the remainder too
-        diff = count - precision - 1
-
-        # Get up to latest so we calculate the remainder
-        power_of_10 = power_of_10(diff)
-
-        # Convert the numerand to decimal base
-        num = num * power_of_5(count)
-
-        # Move to the given precision - 1
-        num = div(num, power_of_10)
-        div = div(num, 10)
-        num = rounding(rounding, sign, num, div)
-
-        # Convert back to float without loss
-        # http://www.exploringbinary.com/correct-decimal-to-floating-point-using-big-integers/
-        den = power_of_10(precision)
-        boundary = den <<< 52
-
-        cond do
-          num == 0 ->
-            0.0
-          num >= boundary ->
-            {den, exp} = scale_down(num, boundary, 52)
-            decimal_to_float(sign, num, den, exp)
-          true ->
-            {num, exp} = scale_up(num, boundary, 52)
-            decimal_to_float(sign, num, den, exp)
-        end
-    end
-  end
-
-  defp scale_up(num, boundary, exp) when num >= boundary, do: {num, exp}
-  defp scale_up(num, boundary, exp), do: scale_up(num <<< 1, boundary, exp - 1)
-
-  defp scale_down(num, den, exp) do
-    new_den = den <<< 1
-    if num < new_den do
-      {den >>> 52, exp}
-    else
-      scale_down(num, new_den, exp + 1)
-    end
-  end
-
-  defp decimal_to_float(sign, num, den, exp) do
-    quo = div(num, den)
-    rem = num - quo * den
-
-    tmp =
-      case den >>> 1 do
-        den when rem > den -> quo + 1
-        den when rem < den -> quo
-        _ when (quo &&& 1) === 1 -> quo + 1
-        _ -> quo
-      end
-
-    tmp = tmp - @power_of_2_to_52
-    <<tmp::float>> = <<sign::1, (exp + 1023)::11, tmp::52>>
-    tmp
-  end
-
-  defp rounding(:floor, 1, _num, div), do: div + 1
-  defp rounding(:ceil, 0, _num, div), do: div + 1
-  defp rounding(:half_up, _sign, num, div) do
-    case rem(num, 10) do
-      rem when rem < 5 -> div
-      rem when rem >= 5 -> div + 1
-    end
-  end
-  defp rounding(_, _, _, div), do: div
-
-  Enum.reduce 0..104, 1, fn x, acc ->
+  Enum.reduce 0..15, 1, fn x, acc ->
     defp power_of_10(unquote(x)), do: unquote(acc)
     acc * 10
   end
 
-  Enum.reduce 0..104, 1, fn x, acc ->
-    defp power_of_5(unquote(x)), do: unquote(acc)
-    acc * 5
-  end
-
   @doc """
-  Returns a pair of integers whose ratio is exactly equal
-  to the original float and with a positive denominator.
+  Returns a char list which corresponds to the text representation of the given float.
+
+  Inlined by the compiler.
 
   ## Examples
 
-      iex> Float.ratio(3.14)
-      {7070651414971679, 2251799813685248}
-      iex> Float.ratio(-3.14)
-      {-7070651414971679, 2251799813685248}
-      iex> Float.ratio(1.5)
-      {3, 2}
-      iex> Float.ratio(-1.5)
-      {-3, 2}
-      iex> Float.ratio(16.0)
-      {16, 1}
-      iex> Float.ratio(-16.0)
-      {-16, 1}
+      iex> Float.to_char_list(7.0)
+      '7.00000000000000000000e+00'
 
   """
-  def ratio(float) when is_float(float) do
-    <<sign::1, exp::11, significant::52-bitstring>> = <<float::float>>
-    {num, _, den} = decompose(significant)
-    num = sign(sign, num)
-    case exp - 1023 do
-      exp when exp > 0 ->
-        {den, exp} = shift_right(den, exp)
-        {shift_left(num, exp), den}
-      exp when exp < 0 ->
-        {num, shift_left(den, -exp)}
-      0 ->
-        {num, den}
-    end
-  end
-
-  defp decompose(significant) do
-    decompose(significant, 1, 0, 2, 1, 1)
-  end
-
-  defp decompose(<<1::1, bits::bitstring>>, count, last_count, power, _last_power, acc) do
-    decompose(bits, count + 1, count, power <<< 1, power, shift_left(acc, count - last_count) + 1)
-  end
-  defp decompose(<<0::1, bits::bitstring>>, count, last_count, power, last_power, acc) do
-    decompose(bits, count + 1, last_count, power <<< 1, last_power, acc)
-  end
-  defp decompose(<<>>, _count, last_count, _power, last_power, acc) do
-    {acc, last_count, last_power}
-  end
-
-  defp sign(0, num), do: num
-  defp sign(1, num), do: -num
-
-  defp shift_left(num, 0), do: num
-  defp shift_left(num, times), do: shift_left(num <<< 1, times - 1)
-
-  defp shift_right(num, 0), do: {num, 0}
-  defp shift_right(1, times), do: {1, times}
-  defp shift_right(num, times), do: shift_right(num >>> 1, times - 1)
-
-  @doc """
-  Returns a charlist which corresponds to the text representation
-  of the given float.
-
-  It uses the shortest representation according to algorithm described
-  in "Printing Floating-Point Numbers Quickly and Accurately" in
-  Proceedings of the SIGPLAN '96 Conference on Programming Language
-  Design and Implementation.
-
-  ## Examples
-
-      iex> Float.to_charlist(7.0)
-      '7.0'
-
-  """
-  @spec to_charlist(float) :: charlist
-  def to_charlist(float) when is_float(float) do
-    :io_lib_format.fwrite_g(float)
+  @spec to_char_list(float) :: char_list
+  def to_char_list(number) do
+    :erlang.float_to_list(number)
   end
 
   @doc """
-  Returns a binary which corresponds to the text representation
-  of the given float.
+  Returns a list which corresponds to the text representation
+  of `float`.
 
-  It uses the shortest representation according to algorithm described
-  in "Printing Floating-Point Numbers Quickly and Accurately" in
-  Proceedings of the SIGPLAN '96 Conference on Programming Language
-  Design and Implementation.
+  ## Options
+
+    * `:decimals`   — number of decimal points to show
+    * `:scientific` — number of decimal points to show, in scientific format
+    * `:compact`    — when true, use the most compact representation (ignored
+                      with the `scientific` option)
 
   ## Examples
 
-      iex> Float.to_string(7.0)
-      "7.0"
+      iex> Float.to_char_list 7.1, [decimals: 2, compact: true]
+      '7.1'
 
   """
-  @spec to_string(float) :: String.t
-  def to_string(float) when is_float(float) do
-    IO.iodata_to_binary(:io_lib_format.fwrite_g(float))
-  end
-
-  # TODO: Remove by 2.0
-  # (hard-deprecated in elixir_dispatch)
-  @doc false
-  def to_char_list(float), do: Float.to_charlist(float)
-
-  @doc false
-  # TODO: Remove by 2.0
-  # (hard-deprecated in elixir_dispatch)
+  @spec to_char_list(float, list) :: char_list
   def to_char_list(float, options) do
     :erlang.float_to_list(float, expand_compact(options))
   end
 
-  @doc false
-  # TODO: Remove by 2.0
-  # (hard-deprecated in elixir_dispatch)
+  @doc """
+  Returns a binary which corresponds to the text representation
+  of `some_float`.
+
+  Inlined by the compiler.
+
+  ## Examples
+
+      iex> Float.to_string(7.0)
+      "7.00000000000000000000e+00"
+
+  """
+  @spec to_string(float) :: String.t
+  def to_string(some_float) do
+    :erlang.float_to_binary(some_float)
+  end
+
+  @doc """
+  Returns a binary which corresponds to the text representation
+  of `float`.
+
+  ## Options
+
+    * `:decimals`   — number of decimal points to show
+    * `:scientific` — number of decimal points to show, in scientific format
+    * `:compact`    — when true, use the most compact representation (ignored
+                      with the `scientific` option)
+
+  ## Examples
+
+      iex> Float.to_string 7.1, [decimals: 2, compact: true]
+      "7.1"
+
+  """
+  @spec to_string(float, list) :: String.t
   def to_string(float, options) do
     :erlang.float_to_binary(float, expand_compact(options))
   end
 
-  defp invalid_precision_message(precision) do
-    "precision #{precision} is out of valid range of #{inspect @precision_range}"
-  end
-
-  defp expand_compact([{:compact, false} | t]), do: expand_compact(t)
-  defp expand_compact([{:compact, true} | t]),  do: [:compact | expand_compact(t)]
-  defp expand_compact([h | t]),                 do: [h | expand_compact(t)]
-  defp expand_compact([]),                      do: []
+  defp expand_compact([{:compact, false}|t]), do: expand_compact(t)
+  defp expand_compact([{:compact, true}|t]),  do: [:compact|expand_compact(t)]
+  defp expand_compact([h|t]),                 do: [h|expand_compact(t)]
+  defp expand_compact([]),                    do: []
 end

lib/elixir/lib/gen_event.ex

@@ -1,90 +1,197 @@
 defmodule GenEvent do
-  # TODO: Remove by 2.0
-
-  # Functions from this module are deprecated in elixir_dispatch.
-
   @moduledoc """
-  WARNING: this module is deprecated.
+  A behaviour module for implementing event handling functionality.
 
-  If you are interested in implementing an event manager, please read the
-  "Alternatives" section below. If you have to implement an event handler to
-  integrate with an existing system, such as Elixir's Logger, please use
-  `:gen_event` instead.
+  The event handling model consists of a generic event manager
+  process with an arbitrary number of event handlers which are
+  added and deleted dynamically.
 
-  ## Alternatives
+  An event manager implemented using this module will have a standard
+  set of interface functions and include functionality for tracing and
+  error reporting. It will also fit into an supervision tree.
 
-  There are a few suitable alternatives to replace GenEvent. Each of them can be
-  the most beneficial based on the use case.
+  ## Example
 
-  ### Supervisor and GenServers
+  There are many use cases for event handlers. For example, a logging
+  system can be built using event handlers where each log message is
+  an event and different event handlers can be plugged to handle the
+  log messages. One handler may print error messages on the terminal,
+  another can write it to a file, while a third one can keep the
+  messages in memory (like a buffer) until they are read.
 
-  One alternative to GenEvent is a very minimal solution consisting of using a
-  supervisor and multiple GenServers started under it. The supervisor acts as
-  the "event manager" and the children GenServers act as the "event handlers".
-  This approach has some shortcomings (it provides no backpressure for example)
-  but can still replace GenEvent for low-profile usages of it. [This blog post
-  by José
-  Valim](http://blog.plataformatec.com.br/2016/11/replacing-genevent-by-a-supervisor-genserver/)
-  has more detailed information on this approach.
+  As an example, let's have a GenEvent that accumulates messages until
+  they are collected by an explicit call.
 
-  ### GenStage
+      defmodule LoggerHandler do
+        use GenEvent
 
-  If the use case where you were using GenEvent requires more complex logic,
-  [GenStage](https://github.com/elixir-lang/gen_stage) provides a great
-  alternative. GenStage is an external Elixir library maintained by the Elixir
-  team; it provides tool to implement systems that exchange events in a
-  demand-driven way with built-in support for backpressure. See the [GenStage
-  documentation](https://hexdocs.pm/gen_stage) for more information.
+        # Callbacks
 
-  ### `:gen_event`
+        def handle_event({:log, x}, messages) do
+          {:ok, [x|messages]}
+        end
 
-  If your use case requires exactly what GenEvent provided, or you have to
-  integrate with an existing `:gen_event`-based system, you can still use the
-  [`:gen_event`](http://erlang.org/doc/man/gen_event.html) Erlang module.
+        def handle_call(:messages, messages) do
+          {:ok, Enum.reverse(messages), []}
+        end
+      end
+
+      {:ok, pid} = GenEvent.start_link()
+
+      GenEvent.add_handler(pid, LoggerHandler, [])
+      #=> :ok
+
+      GenEvent.notify(pid, {:log, 1})
+      #=> :ok
+
+      GenEvent.notify(pid, {:log, 2})
+      #=> :ok
+
+      GenEvent.call(pid, LoggerHandler, :messages)
+      #=> [1, 2]
+
+      GenEvent.call(pid, LoggerHandler, :messages)
+      #=> []
+
+  We start a new event manager by calling `GenEvent.start_link/0`.
+  Notifications can be sent to the event manager which will then
+  invoke `handle_event/2` for each registered handler.
+
+  We can add new handlers with `add_handler/3`. Calls can also
+  be made to specific handlers by using `call/3`.
+
+  ## Callbacks
+
+  There are 6 callbacks required to be implemented in a `GenEvent`. By
+  adding `use GenEvent` to your module, Elixir will automatically define
+  all 6 callbacks for you, leaving it up to you to implement the ones
+  you want to customize. The callbacks are:
+
+    * `init(args)` - invoked when the event handler is added.
+
+      It must return:
+
+      -  `{:ok, state}`
+      -  `{:ok, state, :hibernate}`
+      -  `{:error, reason}`
+
+    * `handle_event(msg, state)` - invoked whenever an event is sent via
+      `notify/2`, `ack_notify/2` or `sync_notify/2`.
+
+      It must return:
+
+      -  `{:ok, new_state}`
+      -  `{:ok, new_state, :hibernate}`
+      -  `:remove_handler`
+
+    * `handle_call(msg, state)` - invoked when a `call/3` is done to a specific
+      handler.
+
+      It must return:
+
+      -  `{:ok, reply, new_state}`
+      -  `{:ok, reply, new_state, :hibernate}`
+      -  `{:remove_handler, reply}`
+
+    * `handle_info(msg, state)` - invoked to handle all other messages which
+      are received by the process. Must return the same values as
+      `handle_event/2`.
+
+    * `terminate(reason, state)` - called when the event handler is removed or
+      the event manager is terminating. It can return any term.
+
+      The reason is one of:
+
+      -  `:stop` - manager is terminating
+      -  `{:stop, reason}` - monitored process terminated (for monitored handlers)
+      -  `:remove_handler` - handler is being removed
+      -  `{:error, term}` - handler crashed or returned a bad value
+      -  `term` - any term passed to functions like `GenEvent.remove_handler/2`
+
+    * `code_change(old_vsn, state, extra)` - called when the application
+      code is being upgraded live (hot code swapping).
+
+      It must return:
+
+      -  `{:ok, new_state}`
+
+  ## Name Registration
+
+  A GenEvent is bound to the same name registration rules as a `GenServer`.
+  Read more about it in the `GenServer` docs.
+
+  ## Modes
+
+  GenEvent stream supports three different notifications.
+
+  On `GenEvent.ack_notify/2`, the manager acknowledges each event,
+  providing back pressure, but processing of the message happens
+  asynchronously.
+
+  On `GenEvent.sync_notify/2`, the manager acknowledges an event
+  just after it was processed by all event handlers.
+
+  On `GenEvent.notify/2`, all events are processed asynchronously and
+  there is no ack (which means there is no backpressure).
+
+  ## Streaming
+
+  `GenEvent`s can be streamed from and streamed with the help of `stream/2`.
+  Here are some examples:
+
+      stream = GenEvent.stream(pid)
+
+      # Take the next 10 events
+      Enum.take(stream, 10)
+
+      # Print all remaining events
+      for event <- stream do
+        IO.inspect event
+      end
+
+  A stream may also be given an id, which allows all streams with the given
+  id to be cancelled at any moment via `cancel_streams/1`.
+
+  ## Learn more and compatibility
+
+  If you wish to find out more about gen events, Elixir getting started
+  guides provide a tutorial-like introduction. The documentation and links
+  in Erlang can also provide extra insight.
+
+    * http://elixir-lang.org/getting_started/mix/1.html
+    * http://www.erlang.org/doc/man/gen_event.html
+    * http://learnyousomeerlang.com/event-handlers
+
+  Keep in mind though Elixir and Erlang gen events are not 100% compatible.
+  The `:gen_event.add_sup_handler/3` is not supported by Elixir's GenEvent,
+  which in turn supports `GenEvent.add_mon_handler/3`.
+
+  The benefits of the monitoring approach are described in the "Don't drink
+  too much kool aid" section of the "Learn you some Erlang" link above. Due
+  to those changes, Elixir's GenEvent does not trap exits by default.
+
+  Futhermore, Elixir's also normalizes the `{:error, _}` tuples returned
+  by many functions, in order to be more consistent with themselves and
+  the `GenServer` module.
   """
 
-  @callback init(args :: term) ::
-    {:ok, state} |
-    {:ok, state, :hibernate} |
-    {:error, reason :: any} when state: any
-
-  @callback handle_event(event :: term, state :: term) ::
-    {:ok, new_state} |
-    {:ok, new_state, :hibernate} |
-    :remove_handler when new_state: term
-
-  @callback handle_call(request :: term, state :: term) ::
-    {:ok, reply, new_state} |
-    {:ok, reply, new_state, :hibernate} |
-    {:remove_handler, reply} when reply: term, new_state: term
-
-  @callback handle_info(msg :: term, state :: term) ::
-    {:ok, new_state} |
-    {:ok, new_state, :hibernate} |
-    :remove_handler when new_state: term
-
-  @callback terminate(reason, state :: term) ::
-    term when reason: :stop | {:stop, term} | :remove_handler | {:error, term} | term
-
-  @callback code_change(old_vsn, state :: term, extra :: term) ::
-    {:ok, new_state :: term} when old_vsn: term | {:down, term}
-
+  @typedoc "Return values of `start*` functions"
   @type on_start :: {:ok, pid} | {:error, {:already_started, pid}}
 
+  @typedoc "The GenEvent manager name"
   @type name :: atom | {:global, term} | {:via, module, term}
 
+  @typedoc "Options used by the `start*` functions"
   @type options :: [name: name]
 
+  @typedoc "The event manager reference"
   @type manager :: pid | name | {atom, node}
 
-  @type handler :: atom | {atom, term}
+  @typedoc "Supported values for new handlers"
+  @type handler :: atom | {atom, term} | {pid, reference}
 
   @doc false
   defmacro __using__(_) do
-    %{file: file, line: line} = __CALLER__
-    deprecation_message = "the GenEvent module is deprecated, see its documentation for alternatives"
-    :elixir_errors.warn(line, file, deprecation_message)
-
     quote location: :keep do
       @behaviour :gen_event
 
@@ -100,16 +207,10 @@ defmodule GenEvent do
 
       @doc false
       def handle_call(msg, state) do
-        proc =
-          case Process.info(self(), :registered_name) do
-            {_, []}   -> self()
-            {_, name} -> name
-          end
-
-        # We do this to trick Dialyzer to not complain about non-local returns.
-        case :erlang.phash2(1, 1) do
-          0 -> raise "attempted to call GenEvent #{inspect proc} but no handle_call/2 clause was provided"
-          1 -> {:remove_handler, {:bad_call, msg}}
+        # We do this to trick dialyzer to not complain about non-local returns.
+        case :random.uniform(1) do
+          1 -> exit({:bad_call, msg})
+          2 -> {:remove_handler, :ok}
         end
       end
 
@@ -133,13 +234,33 @@ defmodule GenEvent do
     end
   end
 
-  @doc false
+  @doc """
+  Starts an event manager linked to the current process.
+
+  This is often used to start the `GenEvent` as part of a supervision tree.
+
+  It accepts the `:name` option which is described under the `Name Registration`
+  section in the `GenServer` module docs.
+
+  If the event manager is successfully created and initialized, the function
+  returns `{:ok, pid}`, where pid is the pid of the server. If there already
+  exists a process with the specified server name, the function returns
+  `{:error, {:already_started, pid}}` with the pid of that process.
+
+  Note that a `GenEvent` started with `start_link/1` is linked to the
+  parent process and will exit not only on crashes but also if the parent
+  process exits with `:normal` reason.
+  """
   @spec start_link(options) :: on_start
   def start_link(options \\ []) when is_list(options) do
     do_start(:link, options)
   end
 
-  @doc false
+  @doc """
+  Starts an event manager process without links (outside of a supervision tree).
+
+  See `start_link/1` for more information.
+  """
   @spec start(options) :: on_start
   def start(options \\ []) when is_list(options) do
     do_start(:nolink, options)
@@ -153,45 +274,107 @@ defmodule GenEvent do
         :gen.start(GenEvent, mode, @no_callback, [], [])
       atom when is_atom(atom) ->
         :gen.start(GenEvent, mode, {:local, atom}, @no_callback, [], [])
-      {:global, _term} = tuple ->
-        :gen.start(GenEvent, mode, tuple, @no_callback, [], [])
-      {:via, via_module, _term} = tuple when is_atom(via_module) ->
-        :gen.start(GenEvent, mode, tuple, @no_callback, [], [])
-      other ->
-        raise ArgumentError, """
-        expected :name option to be one of:
-
-          * nil
-          * atom
-          * {:global, term}
-          * {:via, module, term}
-
-        Got: #{inspect(other)}
-        """
+      other when is_tuple(other) ->
+        :gen.start(GenEvent, mode, other, @no_callback, [], [])
     end
   end
 
-  @doc false
-  @spec stream(manager, keyword) :: GenEvent.Stream.t
+  @doc """
+  Returns a stream that consumes events from the `manager`.
+
+  The stream is a `GenEvent` struct that implements the `Enumerable`
+  protocol. Consumption of events only begins when enumeration starts.
+
+  Note streaming is specific to Elixir's GenEvent and does not work
+  with Erlang ones.
+
+  ## Options
+
+    * `:timeout` - raises if no event arrives in X milliseconds
+      (defaults to `:infinity`)
+
+  """
+  @spec stream(manager, Keyword.t) :: GenEvent.Stream.t
   def stream(manager, options \\ []) do
     %GenEvent.Stream{
       manager: manager,
       timeout: Keyword.get(options, :timeout, :infinity)}
   end
 
-  @doc false
+  @doc """
+  Adds a new event handler to the event `manager`.
+
+  The event manager will call the `init/1` callback with `args` to
+  initiate the event handler and its internal state.
+
+  If `init/1` returns a correct value indicating successful completion,
+  the event manager adds the event handler and this function returns
+  `:ok`. If the callback fails with `reason` or returns `{:error, reason}`,
+  the event handler is ignored and this function returns `{:error, reason}`.
+
+  If the given handler was previously installed at the manager, this
+  function returns `{:error, :already_present}`.
+  """
   @spec add_handler(manager, handler, term) :: :ok | {:error, term}
   def add_handler(manager, handler, args) do
     rpc(manager, {:add_handler, handler, args})
   end
 
-  @doc false
+  @doc """
+  Adds a monitored event handler to the event `manager`.
+
+  Expects the same input and returns the same values as `add_handler/3`.
+
+  ## Monitored handlers
+
+  A monitored handler implies the calling process will now be monitored
+  by the GenEvent manager.
+
+  If the calling process later terminates with `reason`, the event manager
+  will delete the event handler by calling the `terminate/2` callback with
+  `{:stop, reason}` as argument. If the event handler later is deleted,
+  the event manager sends a message `{:gen_event_EXIT, handler, reason}`
+  to the calling process. Reason is one of the following:
+
+    * `:normal` - if the event handler has been removed due to a call to
+      `remove_handler/3`, or `:remove_handler` has been returned by a callback
+      function
+
+    * `:shutdown` - if the event handler has been removed because the event
+      manager is terminating
+
+    * `{:swapped, new_handler, pid}` - if the process pid has replaced the
+      event handler by another
+
+    * a term - if the event handler is removed due to an error. Which term
+      depends on the error
+
+  Keep in mind that the `{:gen_event_EXIT, handler, reason}` message is not
+  guaranteed to be delivered in case the manager crashes. If you want to
+  guarantee the message is delivered, you have two options:
+
+    * monitor the event manager
+    * link to the event manager and then set `Process.flag(:trap_exit, true)`
+      in your handler callback
+
+  Finally, this functionality only works with GenEvent started via this
+  module (it is not backwards compatible with Erlang's `:gen_event`).
+  """
   @spec add_mon_handler(manager, handler, term) :: :ok | {:error, term}
   def add_mon_handler(manager, handler, args) do
     rpc(manager, {:add_mon_handler, handler, args, self()})
   end
 
-  @doc false
+  @doc """
+  Sends an event notification to the event `manager`.
+
+  The event manager will call `handle_event/2` for each
+  installed event handler.
+
+  `notify` is asynchronous and will return immediately after the
+  notification is sent. `notify` will not fail even if the specified
+  event manager does not exist, unless it is specified as an atom.
+  """
   @spec notify(manager, term) :: :ok
   def notify(manager, event)
 
@@ -204,7 +387,7 @@ defmodule GenEvent do
     end
   end
 
-  def notify({:via, mod, name}, msg) when is_atom(mod) do
+  def notify({:via, mod, name}, msg) do
     try do
       mod.send(name, {:notify, msg})
       :ok
@@ -213,28 +396,50 @@ defmodule GenEvent do
     end
   end
 
-  def notify(manager, msg)
-      when is_pid(manager)
-      when is_atom(manager)
-      when tuple_size(manager) == 2 and
-        is_atom(elem(manager, 0)) and is_atom(elem(manager, 1)) do
-    send(manager, {:notify, msg})
+  def notify(other, msg) do
+    send(other, {:notify, msg})
     :ok
   end
 
-  @doc false
+  @doc """
+  Sends a sync event notification to the event `manager`.
+
+  In other words, this function only returns `:ok` after the event manager
+  invokes the `handle_event/2` on each installed event handler.
+
+  See `notify/2` for more info.
+  """
   @spec sync_notify(manager, term) :: :ok
   def sync_notify(manager, event) do
     rpc(manager, {:sync_notify, event})
   end
 
-  @doc false
+  @doc """
+  Sends a ack event notification to the event `manager`.
+
+  In other words, this function only returns `:ok` as soon as the
+  event manager starts processing this event, but it does not wait
+  for event handlers to process the sent event.
+
+  See `notify/2` for more info. Note this function is specific
+  to Elixir's GenEvent and does not work with Erlang ones.
+  """
   @spec ack_notify(manager, term) :: :ok
   def ack_notify(manager, event) do
     rpc(manager, {:ack_notify, event})
   end
 
-  @doc false
+  @doc """
+  Makes a synchronous call to the event `handler` installed in `manager`.
+
+  The given `request` is sent and the caller waits until a reply arrives or
+  a timeout occurs. The event manager will call `handle_call/2` to handle
+  the request.
+
+  The return value `reply` is defined in the return value of `handle_call/2`.
+  If the specified event handler is not installed, the function returns
+  `{:error, :not_found}`.
+  """
   @spec call(manager, handler, term, timeout) ::  term | {:error, term}
   def call(manager, handler, request, timeout \\ 5000) do
     try do
@@ -247,37 +452,70 @@ defmodule GenEvent do
     end
   end
 
-  @doc false
+  @doc """
+  Removes an event handler from the event `manager`.
+
+  The event manager will call `terminate/2` to terminate the event handler
+  and return the callback value. If the specified event handler is not
+  installed, the function returns `{:error, :not_found}`.
+  """
   @spec remove_handler(manager, handler, term) :: term | {:error, term}
   def remove_handler(manager, handler, args) do
     rpc(manager, {:delete_handler, handler, args})
   end
 
-  @doc false
+  @doc """
+  Replaces an old event handler with a new one in the event `manager`.
+
+  First, the old event handler is deleted by calling `terminate/2` with
+  the given `args1` and collects the return value. Then the new event handler
+  is added and initiated by calling `init({args2, state}), where term is the
+  return value of calling `terminate/2` in the old handler. This makes it
+  possible to transfer information from one handler to another.
+
+  The new handler will be added even if the specified old event handler
+  is not installed or if the handler fails to terminate with a given reason
+  in which case `state = {:error, term}`.
+
+  If `init/1` in the second handler returns a correct value, this
+  function returns `:ok`.
+  """
   @spec swap_handler(manager, handler, term, handler, term) :: :ok | {:error, term}
   def swap_handler(manager, handler1, args1, handler2, args2) do
     rpc(manager, {:swap_handler, handler1, args1, handler2, args2})
   end
 
-  @doc false
+  @doc """
+  Replaces an old event handler with a new monitored one in the event `manager`.
+
+  Read the docs for `add_mon_handler/3` and `swap_handler/5` for more information.
+  """
   @spec swap_mon_handler(manager, handler, term, handler, term) :: :ok | {:error, term}
   def swap_mon_handler(manager, handler1, args1, handler2, args2) do
     rpc(manager, {:swap_mon_handler, handler1, args1, handler2, args2, self()})
   end
 
-  @doc false
+  @doc """
+  Returns a list of all event handlers installed in the `manager`.
+  """
   @spec which_handlers(manager) :: [handler]
   def which_handlers(manager) do
     rpc(manager, :which_handlers)
   end
 
-  @doc false
-  @spec stop(manager, reason :: term, timeout) :: :ok
-  def stop(manager, reason \\ :normal, timeout \\ :infinity) do
-    :gen.stop(manager, reason, timeout)
+  @doc """
+  Terminates the event `manager`.
+
+  Before terminating, the event manager will call `terminate(:stop, ...)`
+  for each installed event handler.
+  """
+  @spec stop(manager) :: :ok
+  def stop(manager) do
+    rpc(manager, :stop)
   end
 
   defp rpc(module, cmd) do
+    # TODO: Change the tag once patch is accepted by OTP
     {:ok, reply} = :gen.call(module, self(), cmd, :infinity)
     reply
   end
@@ -292,14 +530,9 @@ defmodule GenEvent do
     init_it(starter, self(), name, mod, args, options)
   end
 
-  def init_it(starter, parent, name, _mod, _args, options) do
+  def init_it(starter, parent, name, _, _, options) do
     Process.put(:"$initial_call", {__MODULE__, :init_it, 6})
-    debug =
-      if function_exported?(:gen, :debug_options, 2) do
-        :gen.debug_options(name, options)
-      else
-        :gen.debug_options(options)
-      end
+    debug = :gen.debug_options(options)
     :proc_lib.init_ack(starter, {:ok, self()})
     loop(parent, name(name), [], debug, false)
   end
@@ -391,6 +624,13 @@ defmodule GenEvent do
         {hib, reply, handlers} = server_swap_handler(handler1, args1, handler2, args2, handlers, mon, name)
         reply(tag, reply)
         loop(parent, name, handlers, debug, hib)
+      {_from, tag, :stop} ->
+        try do
+          server_terminate(:normal, parent, handlers, name)
+        catch
+          :exit, :normal -> :ok
+        end
+        reply(tag, :ok)
       {_from, tag, :which_handlers} ->
         reply(tag, server_which_handlers(handlers))
         loop(parent, name, handlers, debug, false)
@@ -416,7 +656,7 @@ defmodule GenEvent do
   end
 
   @doc false
-  def system_code_change([name, handlers, hib], module, old_vsn, extra) do
+  def system_code_change([name, handlers, hib], module , old_vsn, extra) do
     handlers =
       for handler <- handlers do
         if handler(handler, :module) == module do
@@ -550,13 +790,13 @@ defmodule GenEvent do
     {hib, server_collect_process_handlers(mode, event, streams, handlers, name)}
   end
 
-  defp server_split_process_handlers(mode, event, [handler | t], handlers, streams) do
+  defp server_split_process_handlers(mode, event, [handler|t], handlers, streams) do
     case handler(handler, :id) do
       {pid, _ref} when is_pid(pid) ->
         server_process_notify(mode, event, handler)
-        server_split_process_handlers(mode, event, t, handlers, [handler | streams])
+        server_split_process_handlers(mode, event, t, handlers, [handler|streams])
       _ ->
-        server_split_process_handlers(mode, event, t, [handler | handlers], streams)
+        server_split_process_handlers(mode, event, t, [handler|handlers], streams)
     end
   end
 
@@ -572,10 +812,10 @@ defmodule GenEvent do
   defp mode_to_tag(:sync),  do: :sync_notify
   defp mode_to_tag(:async), do: :notify
 
-  defp server_notify(event, fun, [handler | t], name, handlers, acc, hib) do
+  defp server_notify(event, fun, [handler|t], name, handlers, acc, hib) do
     case server_update(handler, fun, event, name, handlers) do
       {new_hib, handler} ->
-        server_notify(event, fun, t, name, handlers, [handler | acc], hib or new_hib)
+        server_notify(event, fun, t, name, handlers, [handler|acc], hib or new_hib)
       :error ->
         server_notify(event, fun, t, name, handlers, acc, hib)
     end
@@ -609,16 +849,16 @@ defmodule GenEvent do
     end
   end
 
-  defp server_collect_process_handlers(:async, event, [handler | t], handlers, name) do
-    server_collect_process_handlers(:async, event, t, [handler | handlers], name)
+  defp server_collect_process_handlers(:async, event, [handler|t], handlers, name) do
+    server_collect_process_handlers(:async, event, t, [handler|handlers], name)
   end
 
-  defp server_collect_process_handlers(mode, event, [handler | t], handlers, name) when mode in [:sync, :ack] do
+  defp server_collect_process_handlers(mode, event, [handler|t], handlers, name) when mode in [:sync, :ack] do
     handler(ref: ref, id: id) = handler
 
     receive do
       {^ref, :ok} ->
-        server_collect_process_handlers(mode, event, t, [handler | handlers], name)
+        server_collect_process_handlers(mode, event, t, [handler|handlers], name)
       {_from, tag, {:delete_handler, ^id, args}} ->
         do_terminate(handler, args, :remove, name, :normal)
         reply(tag, :ok)
@@ -708,9 +948,9 @@ defmodule GenEvent do
           {:ok, res} ->
             case res do
               {:ok, state} ->
-                {false, succ, [handler(handler, state: state) | handlers]}
+                {false, succ, [handler(handler, state: state)|handlers]}
               {:ok, state, :hibernate} ->
-                {true, succ, [handler(handler, state: state) | handlers]}
+                {true, succ, [handler(handler, state: state)|handlers]}
               {:error, _} = error ->
                 {false, error, handlers}
               other ->
@@ -773,9 +1013,9 @@ defmodule GenEvent do
   defp report_error(handler, reason, state, last_in, name) do
     reason =
       case reason do
-        {:undef, [{m, f, a, _} | _] = mfas} ->
+        {:undef, [{m,f,a,_}|_]=mfas} ->
           cond do
-            :code.is_loaded(m) === false ->
+            :code.is_loaded(m) ->
               {:"module could not be loaded", mfas}
             function_exported?(m, f, length(a)) ->
               reason

lib/elixir/lib/gen_event/stream.ex

@@ -1,5 +1,14 @@
 defmodule GenEvent.Stream do
-  @moduledoc false
+  @moduledoc """
+  Defines a `GenEvent` stream.
+
+  This is a struct returned by `stream/2`. The struct is public and
+  contains the following fields:
+
+    * `:manager`  - the manager reference given to `GenEvent.stream/2`
+    * `:timeout`  - the timeout in between events, defaults to `:infinity`
+
+  """
   defstruct manager: nil, timeout: :infinity
 
   @type t :: %__MODULE__{
@@ -13,21 +22,12 @@ defmodule GenEvent.Stream do
 
   @doc false
   def handle_event(event, _state) do
-    # We do this to trick Dialyzer to not complain about non-local returns.
-    case :erlang.phash2(1, 1) do
-      0 -> exit({:bad_event, event})
-      1 -> :remove_handler
-    end
+    exit({:bad_event, event})
   end
 
   @doc false
   def handle_call(msg, _state) do
-    # We do this to trick Dialyzer to not complain about non-local returns.
-    reason = {:bad_call, msg}
-    case :erlang.phash2(1, 1) do
-      0 -> exit(reason)
-      1 -> {:remove_handler, reason}
-    end
+    exit({:bad_call, msg})
   end
 
   @doc false
@@ -137,15 +137,21 @@ defimpl Enumerable, for: GenEvent.Stream do
   # If we reach this branch, the handler was not removed yet,
   # so we trigger a request for doing so.
   defp stop(stream, {pid, ref, _} = acc) do
-    _ = :gen_event.delete_handler(pid, {pid, ref}, :shutdown)
+    _ = GenEvent.remove_handler(pid, {pid, ref}, :shutdown)
     stop(stream, {:removed, acc})
   end
 
   defp wait_for_handler_removal(pid, ref, mon_ref) do
     receive do
-      {:gen_event_EXIT, {^pid, ^ref}, _reason} ->
+      {:gen_event_EXIT, {^pid, ^ref}, reason}
+          when reason == :normal
+          when reason == :shutdown
+          when tuple_size(reason) == 3 and elem(reason, 0) == :swapped  ->
         Process.demonitor(mon_ref, [:flush])
         :ok
+      {:gen_event_EXIT, {^pid, ^ref}, reason} ->
+        Process.demonitor(mon_ref, [:flush])
+        {:error, reason}
       {:DOWN, ^mon_ref, _, _, reason} ->
         {:error, reason}
     end

lib/elixir/lib/gen_server.ex

@@ -2,7 +2,7 @@ defmodule GenServer do
   @moduledoc """
   A behaviour module for implementing the server of a client-server relation.
 
-  A GenServer is a process like any other Elixir process and it can be used
+  A GenServer is a process as any other Elixir process and it can be used
   to keep state, execute code asynchronously and so on. The advantage of using
   a generic server process (GenServer) implemented using this module is that it
   will have a standard set of interface functions and include functionality for
@@ -11,8 +11,8 @@ defmodule GenServer do
   ## Example
 
   The GenServer behaviour abstracts the common client-server interaction.
-  Developers are only required to implement the callbacks and functionality
-  they are interested in.
+  Developers are only required to implement the callbacks and functionality they are
+  interested in.
 
   Let's start with a code example and then explore the available callbacks.
   Imagine we want a GenServer that works like a stack, allowing us to push
@@ -23,12 +23,12 @@ defmodule GenServer do
 
         # Callbacks
 
-        def handle_call(:pop, _from, [h | t]) do
+        def handle_call(:pop, _from, [h|t]) do
           {:reply, h, t}
         end
 
         def handle_cast({:push, item}, state) do
-          {:noreply, [item | state]}
+          {:noreply, [item|state]}
         end
       end
 
@@ -53,30 +53,58 @@ defmodule GenServer do
   while **cast** messages do not.
 
   Every time you do a `GenServer.call/3`, the client will send a message
-  that must be handled by the `c:handle_call/3` callback in the GenServer.
-  A `cast/2` message must be handled by `c:handle_cast/2`.
+  that must be handled by the `handle_call/3` callback in the GenServer.
+  A `cast/2` message must be handled by `handle_cast/2`.
 
-  ## use GenServer and callbacks
+  ## Callbacks
 
   There are 6 callbacks required to be implemented in a `GenServer`. By
   adding `use GenServer` to your module, Elixir will automatically define
   all 6 callbacks for you, leaving it up to you to implement the ones
-  you want to customize.
+  you want to customize. The callbacks are:
 
-  `use GenServer` also defines a `child_spec/1` function, allowing the
-  defined module to be put under a supervision tree. The generated
-  `child_spec/1` can be customized with the following options:
+    * `init(args)` - invoked when the server is started.
 
-    * `:id` - the child specification id, defauts to the current module
-    * `:start` - how to start the child process (defaults to calling `__MODULE__.start_link/1`)
-    * `:restart` - when the child should be restarted, defaults to `:permanent`
-    * `:shutdown` - how to shut down the child
+      It must return:
 
-  For example:
+      -  `{:ok, state}`
+      -  `{:ok, state, timeout}`
+      -  `:ignore`
+      -  `{:stop, reason}`
 
-      use GenServer, restart: :transient, shutdown: 10_000
+    * `handle_call(msg, {from, ref}, state)` and `handle_cast(msg, state)` -
+      invoked to handle call (sync) and cast (async) messages.
 
-  See the `Supervisor` docs for more information.
+      It must return:
+
+      -  `{:reply, reply, new_state}`
+      -  `{:reply, reply, new_state, timeout}`
+      -  `{:reply, reply, new_state, :hibernate}`
+      -  `{:noreply, new_state}`
+      -  `{:noreply, new_state, timeout}`
+      -  `{:noreply, new_state, :hibernate}`
+      -  `{:stop, reason, new_state}`
+      -  `{:stop, reason, reply, new_state}`
+
+    * `handle_info(msg, state)` - invoked to handle all other messages which
+      are received by the process.
+
+      It must return:
+
+      -  `{:noreply, state}`
+      -  `{:noreply, state, timeout}`
+      -  `{:stop, reason, state}`
+
+    * `terminate(reason, state)` - called when the server is about to
+      terminate, useful for cleaning up. It must return `:ok`.
+
+    * `code_change(old_vsn, state, extra)` - called when the application
+      code is being upgraded live (hot code swapping).
+
+      It must return:
+
+      -  `{:ok, new_state}`
+      -  `{:error, reason}`
 
   ## Name Registration
 
@@ -88,18 +116,13 @@ defmodule GenServer do
       using `Process.register/2`.
 
     * `{:global, term}`- the GenServer is registered globally with the given
-      term using the functions in the [`:global` module](http://www.erlang.org/doc/man/global.html).
+      term using the functions in the `:global` module.
 
     * `{:via, module, term}` - the GenServer is registered with the given
-      mechanism and name. The `:via` option expects a module that exports
-      `register_name/2`, `unregister_name/1`, `whereis_name/1` and `send/2`.
-      One such example is the [`:global` module](http://www.erlang.org/doc/man/global.html) which uses these functions
-      for keeping the list of names of processes and their associated PIDs
-      that are available globally for a network of Elixir nodes. Elixir also
-      ships with a local, decentralized and scalable registry called `Registry`
-      for locally storing names that are generated dynamically.
+      mechanism and name. The `:via` option expects a module name to control
+      the registration mechanism alongside a name which can be any term.
 
-  For example, we could start and register our `Stack` server locally as follows:
+  For example, we could start and register our Stack server locally as follows:
 
       # Start the server and register it locally with name MyStack
       {:ok, _} = GenServer.start_link(Stack, [:hello], name: MyStack)
@@ -118,11 +141,6 @@ defmodule GenServer do
     * `{:via, module, name}` if the server is registered through an alternative
       registry
 
-  If there is an interest to register dynamic names locally, do not use
-  atoms, as atoms are never garbage collected and therefore dynamically
-  generated atoms won't be garbage collected. For such cases, you can
-  set up your own local registry by using the `Registry` module.
-
   ## Client / Server APIs
 
   Although in the example above we have used `GenServer.start_link/3` and
@@ -151,7 +169,7 @@ defmodule GenServer do
 
         # Server (callbacks)
 
-        def handle_call(:pop, _from, [h | t]) do
+        def handle_call(:pop, _from, [h|t]) do
           {:reply, h, t}
         end
 
@@ -161,7 +179,7 @@ defmodule GenServer do
         end
 
         def handle_cast({:push, item}, state) do
-          {:noreply, [item | state]}
+          {:noreply, [item|state]}
         end
 
         def handle_cast(request, state) do
@@ -173,364 +191,18 @@ defmodule GenServer do
   the same module. If the server and/or client implementations are growing
   complex, you may want to have them in different modules.
 
-  ## Receiving "regular" messages
-
-  The goal of a `GenServer` is to abstract the "receive" loop for developers,
-  automatically handling system messages, support code change, synchronous
-  calls and more. Therefore, you should never call your own "receive" inside
-  the GenServer callbacks as doing so will cause the GenServer to misbehave.
-
-  Besides the synchronous and asynchronous communication provided by `call/3`
-  and `cast/2`, "regular" messages sent by functions such `Kernel.send/2`,
-  `Process.send_after/4` and similar, can be handled inside the `c:handle_info/2`
-  callback.
-
-  `c:handle_info/2` can be used in many situations, such as handling monitor
-  DOWN messages sent by `Process.monitor/1`. Another use case for `c:handle_info/2`
-  is to perform periodic work, with the help of `Process.send_after/4`:
-
-      defmodule MyApp.Periodically do
-        use GenServer
-
-        def start_link do
-          GenServer.start_link(__MODULE__, %{})
-        end
-
-        def init(state) do
-          schedule_work() # Schedule work to be performed on start
-          {:ok, state}
-        end
-
-        def handle_info(:work, state) do
-          # Do the desired work here
-          schedule_work() # Reschedule once more
-          {:noreply, state}
-        end
-
-        defp schedule_work() do
-          Process.send_after(self(), :work, 2 * 60 * 60 * 1000) # In 2 hours
-        end
-      end
-
-  ## Debugging with the :sys module
-
-  GenServers, as [special processes](http://erlang.org/doc/design_principles/spec_proc.html),
-  can be debugged using the [`:sys` module](http://www.erlang.org/doc/man/sys.html). Through various hooks, this module
-  allows developers to introspect the state of the process and trace
-  system events that happen during its execution, such as received messages,
-  sent replies and state changes.
-
-  Let's explore the basic functions from the [`:sys` module](http://www.erlang.org/doc/man/sys.html) used for debugging:
-
-    * [`:sys.get_state/2`](http://erlang.org/doc/man/sys.html#get_state-2) -
-      allows retrieval of the state of the process. In the case of
-      a GenServer process, it will be the callback module state, as
-      passed into the callback functions as last argument.
-    * [`:sys.get_status/2`](http://erlang.org/doc/man/sys.html#get_status-2) -
-      allows retrieval of the status of the process. This status includes
-      the process dictionary, if the process is running or is suspended,
-      the parent PID, the debugger state, and the state of the behaviour module,
-      which includes the callback module state (as returned by `:sys.get_state/2`).
-      It's possible to change how this status is represented by defining
-      the optional `c:GenServer.format_status/2` callback.
-    * [`:sys.trace/3`](http://erlang.org/doc/man/sys.html#trace-3) -
-      prints all the system events to `:stdio`.
-    * [`:sys.statistics/3`](http://erlang.org/doc/man/sys.html#statistics-3) -
-      manages collection of process statistics.
-    * [`:sys.no_debug/2`](http://erlang.org/doc/man/sys.html#no_debug-2) -
-      turns off all debug handlers for the given process. It is very important
-      to switch off debugging once we're done. Excessive debug handlers or
-      those that should be turned off, but weren't, can seriously damage
-      the performance of the system.
-    * [`:sys.suspend/2`](http://erlang.org/doc/man/sys.html#suspend-2) - allows
-      to suspend a process so that it only replies to system messages but no
-      other messages. A suspended process can be reactivated via
-      [`:sys.resume/2`](http://erlang.org/doc/man/sys.html#resume-2).
-
-  Let's see how we could use those functions for debugging the stack server
-  we defined earlier.
-
-      iex> {:ok, pid} = Stack.start_link([])
-      iex> :sys.statistics(pid, true) # turn on collecting process statistics
-      iex> :sys.trace(pid, true) # turn on event printing
-      iex> Stack.push(pid, 1)
-      *DBG* <0.122.0> got cast {push,1}
-      *DBG* <0.122.0> new state [1]
-      :ok
-      iex> :sys.get_state(pid)
-      [1]
-      iex> Stack.pop(pid)
-      *DBG* <0.122.0> got call pop from <0.80.0>
-      *DBG* <0.122.0> sent 1 to <0.80.0>, new state []
-      1
-      iex> :sys.statistics(pid, :get)
-      {:ok,
-       [start_time: {{2016, 7, 16}, {12, 29, 41}},
-        current_time: {{2016, 7, 16}, {12, 29, 50}},
-        reductions: 117, messages_in: 2, messages_out: 0]}
-      iex> :sys.no_debug(pid) # turn off all debug handlers
-      :ok
-      iex> :sys.get_status(pid)
-      {:status, #PID<0.122.0>, {:module, :gen_server},
-       [["$initial_call": {Stack, :init, 1},            # pdict
-         "$ancestors": [#PID<0.80.0>, #PID<0.51.0>]],
-        :running,                                       # :running | :suspended
-        #PID<0.80.0>,                                   # parent
-        [],                                             # debugger state
-        [header: 'Status for generic server <0.122.0>', # module status
-         data: [{'Status', :running}, {'Parent', #PID<0.80.0>},
-           {'Logged events', []}], data: [{'State', [1]}]]]}
-
   ## Learn more
 
-  If you wish to find out more about gen servers, the Elixir Getting Started
-  guide provides a tutorial-like introduction. The documentation and links
+  If you wish to find out more about gen servers, Elixir getting started
+  guides provide a tutorial-like introduction. The documentation and links
   in Erlang can also provide extra insight.
 
-    * [GenServer – Elixir's Getting Started Guide](http://elixir-lang.org/getting-started/mix-otp/genserver.html)
-    * [`:gen_server` module documentation](http://www.erlang.org/doc/man/gen_server.html)
-    * [gen_server Behaviour – OTP Design Principles](http://www.erlang.org/doc/design_principles/gen_server_concepts.html)
-    * [Clients and Servers – Learn You Some Erlang for Great Good!](http://learnyousomeerlang.com/clients-and-servers)
+    * http://elixir-lang.org/getting_started/mix/1.html
+    * http://www.erlang.org/doc/man/gen_server.html
+    * http://www.erlang.org/doc/design_principles/gen_server_concepts.html
+    * http://learnyousomeerlang.com/clients-and-servers
   """
 
-  @doc """
-  Invoked when the server is started. `start_link/3` or `start/3` will
-  block until it returns.
-
-  `args` is the argument term (second argument) passed to `start_link/3`.
-
-  Returning `{:ok, state}` will cause `start_link/3` to return
-  `{:ok, pid}` and the process to enter its loop.
-
-  Returning `{:ok, state, timeout}` is similar to `{:ok, state}`
-  except `handle_info(:timeout, state)` will be called after `timeout`
-  milliseconds if no messages are received within the timeout.
-
-  Returning `{:ok, state, :hibernate}` is similar to
-  `{:ok, state}` except the process is hibernated before entering the loop. See
-  `c:handle_call/3` for more information on hibernation.
-
-  Returning `:ignore` will cause `start_link/3` to return `:ignore` and the
-  process will exit normally without entering the loop or calling `c:terminate/2`.
-  If used when part of a supervision tree the parent supervisor will not fail
-  to start nor immediately try to restart the `GenServer`. The remainder of the
-  supervision tree will be (re)started and so the `GenServer` should not be
-  required by other processes. It can be started later with
-  `Supervisor.restart_child/2` as the child specification is saved in the parent
-  supervisor. The main use cases for this are:
-
-    * The `GenServer` is disabled by configuration but might be enabled later.
-    * An error occurred and it will be handled by a different mechanism than the
-     `Supervisor`. Likely this approach involves calling `Supervisor.restart_child/2`
-      after a delay to attempt a restart.
-
-  Returning `{:stop, reason}` will cause `start_link/3` to return
-  `{:error, reason}` and the process to exit with reason `reason` without
-  entering the loop or calling `c:terminate/2`.
-  """
-  @callback init(args :: term) ::
-    {:ok, state} |
-    {:ok, state, timeout | :hibernate} |
-    :ignore |
-    {:stop, reason :: any} when state: any
-
-  @doc """
-  Invoked to handle synchronous `call/3` messages. `call/3` will block until a
-  reply is received (unless the call times out or nodes are disconnected).
-
-  `request` is the request message sent by a `call/3`, `from` is a 2-tuple
-  containing the caller's PID and a term that uniquely identifies the call, and
-  `state` is the current state of the `GenServer`.
-
-  Returning `{:reply, reply, new_state}` sends the response `reply` to the
-  caller and continues the loop with new state `new_state`.
-
-  Returning `{:reply, reply, new_state, timeout}` is similar to
-  `{:reply, reply, new_state}` except `handle_info(:timeout, new_state)` will be
-  called after `timeout` milliseconds if no messages are received.
-
-  Returning `{:reply, reply, new_state, :hibernate}` is similar to
-  `{:reply, reply, new_state}` except the process is hibernated and will
-  continue the loop once a message is in its message queue. If a message is
-  already in the message queue this will be immediately. Hibernating a
-  `GenServer` causes garbage collection and leaves a continuous heap that
-  minimises the memory used by the process.
-
-  Hibernating should not be used aggressively as too much time could be spent
-  garbage collecting. Normally it should only be used when a message is not
-  expected soon and minimising the memory of the process is shown to be
-  beneficial.
-
-  Returning `{:noreply, new_state}` does not send a response to the caller and
-  continues the loop with new state `new_state`. The response must be sent with
-  `reply/2`.
-
-  There are three main use cases for not replying using the return value:
-
-    * To reply before returning from the callback because the response is known
-      before calling a slow function.
-    * To reply after returning from the callback because the response is not yet
-      available.
-    * To reply from another process, such as a task.
-
-  When replying from another process the `GenServer` should exit if the other
-  process exits without replying as the caller will be blocking awaiting a
-  reply.
-
-  Returning `{:noreply, new_state, timeout | :hibernate}` is similar to
-  `{:noreply, new_state}` except a timeout or hibernation occurs as with a
-  `:reply` tuple.
-
-  Returning `{:stop, reason, reply, new_state}` stops the loop and `c:terminate/2`
-  is called with reason `reason` and state `new_state`. Then the `reply` is sent
-  as the response to call and the process exits with reason `reason`.
-
-  Returning `{:stop, reason, new_state}` is similar to
-  `{:stop, reason, reply, new_state}` except a reply is not sent.
-
-  If this callback is not implemented, the default implementation by
-  `use GenServer` will return `{:stop, {:bad_call, request}, state}`.
-  """
-  @callback handle_call(request :: term, from, state :: term) ::
-    {:reply, reply, new_state} |
-    {:reply, reply, new_state, timeout | :hibernate} |
-    {:noreply, new_state} |
-    {:noreply, new_state, timeout | :hibernate} |
-    {:stop, reason, reply, new_state} |
-    {:stop, reason, new_state} when reply: term, new_state: term, reason: term
-
-  @doc """
-  Invoked to handle asynchronous `cast/2` messages.
-
-  `request` is the request message sent by a `cast/2` and `state` is the current
-  state of the `GenServer`.
-
-  Returning `{:noreply, new_state}` continues the loop with new state `new_state`.
-
-  Returning `{:noreply, new_state, timeout}` is similar to
-  `{:noreply, new_state}` except `handle_info(:timeout, new_state)` will be
-  called after `timeout` milliseconds if no messages are received.
-
-  Returning `{:noreply, new_state, :hibernate}` is similar to
-  `{:noreply, new_state}` except the process is hibernated before continuing the
-  loop. See `c:handle_call/3` for more information.
-
-  Returning `{:stop, reason, new_state}` stops the loop and `c:terminate/2` is
-  called with the reason `reason` and state `new_state`. The process exits with
-  reason `reason`.
-
-  If this callback is not implemented, the default implementation by
-  `use GenServer` will return `{:stop, {:bad_cast, request}, state}`.
-  """
-  @callback handle_cast(request :: term, state :: term) ::
-    {:noreply, new_state} |
-    {:noreply, new_state, timeout | :hibernate} |
-    {:stop, reason :: term, new_state} when new_state: term
-
-  @doc """
-  Invoked to handle all other messages.
-
-  `msg` is the message and `state` is the current state of the `GenServer`. When
-  a timeout occurs the message is `:timeout`.
-
-  Return values are the same as `c:handle_cast/2`.
-
-  If this callback is not implemented, the default implementation by
-  `use GenServer` will return `{:noreply, state}`.
-  """
-  @callback handle_info(msg :: :timeout | term, state :: term) ::
-    {:noreply, new_state} |
-    {:noreply, new_state, timeout | :hibernate} |
-    {:stop, reason :: term, new_state} when new_state: term
-
-  @doc """
-  Invoked when the server is about to exit. It should do any cleanup required.
-
-  `reason` is exit reason and `state` is the current state of the `GenServer`.
-  The return value is ignored.
-
-  `c:terminate/2` is called if a callback (except `c:init/1`) does one of the
-  following:
-
-    * returns a `:stop` tuple
-    * raises
-    * calls `Kernel.exit/1`
-    * returns an invalid value
-    * the `GenServer` traps exits (using `Process.flag/2`) *and* the parent
-      process sends an exit signal
-
-  If part of a supervision tree, a `GenServer`'s `Supervisor` will send an exit
-  signal when shutting it down. The exit signal is based on the shutdown
-  strategy in the child's specification. If it is `:brutal_kill` the `GenServer`
-  is killed and so `c:terminate/2` is not called. However if it is a timeout the
-  `Supervisor` will send the exit signal `:shutdown` and the `GenServer` will
-  have the duration of the timeout to call `c:terminate/2` - if the process is
-  still alive after the timeout it is killed.
-
-  If the `GenServer` receives an exit signal (that is not `:normal`) from any
-  process when it is not trapping exits it will exit abruptly with the same
-  reason and so not call `c:terminate/2`. Note that a process does *NOT* trap
-  exits by default and an exit signal is sent when a linked process exits or its
-  node is disconnected.
-
-  Therefore it is not guaranteed that `c:terminate/2` is called when a `GenServer`
-  exits. For such reasons, we usually recommend important clean-up rules to
-  happen in separated processes either by use of monitoring or by links
-  themselves. For example if the `GenServer` controls a `port` (e.g.
-  `:gen_tcp.socket`) or `t:File.io_device/0`, they will be closed on receiving a
-  `GenServer`'s exit signal and do not need to be closed in `c:terminate/2`.
-
-  If `reason` is not `:normal`, `:shutdown`, nor `{:shutdown, term}` an error is
-  logged.
-  """
-  @callback terminate(reason, state :: term) ::
-    term when reason: :normal | :shutdown | {:shutdown, term} | term
-
-  @doc """
-  Invoked to change the state of the `GenServer` when a different version of a
-  module is loaded (hot code swapping) and the state's term structure should be
-  changed.
-
-  `old_vsn` is the previous version of the module (defined by the `@vsn`
-  attribute) when upgrading. When downgrading the previous version is wrapped in
-  a 2-tuple with first element `:down`. `state` is the current state of the
-  `GenServer` and `extra` is any extra data required to change the state.
-
-  Returning `{:ok, new_state}` changes the state to `new_state` and the code
-  change is successful.
-
-  Returning `{:error, reason}` fails the code change with reason `reason` and
-  the state remains as the previous state.
-
-  If `c:code_change/3` raises the code change fails and the loop will continue
-  with its previous state. Therefore this callback does not usually contain side effects.
-  """
-  @callback code_change(old_vsn, state :: term, extra :: term) ::
-    {:ok, new_state :: term} |
-    {:error, reason :: term} when old_vsn: term | {:down, term}
-
-  @doc """
-  Invoked in some cases to retrieve a formatted version of the `GenServer` status.
-
-  This callback can be useful to control the *appearance* of the status of the
-  `GenServer`. For example, it can be used to return a compact representation of
-  the `GenServer`'s state to avoid having large state terms printed.
-
-    * one of `:sys.get_status/1` or `:sys.get_status/2` is invoked to get the
-      status of the `GenServer`; in such cases, `reason` is `:normal`
-
-    * the `GenServer` terminates abnormally and logs an error; in such cases,
-      `reason` is `:terminate`
-
-  `pdict_and_state` is a two-elements list `[pdict, state]` where `pdict` is a
-  list of `{key, value}` tuples representing the current process dictionary of
-  the `GenServer` and `state` is the current state of the `GenServer`.
-  """
-  @callback format_status(reason, pdict_and_state :: list) ::
-    term when reason: :normal | :terminate
-
-  @optional_callbacks format_status: 2
-
   @typedoc "Return values of `start*` functions"
   @type on_start :: {:ok, pid} | :ignore | {:error, {:already_started, pid} | term}
 
@@ -538,47 +210,21 @@ defmodule GenServer do
   @type name :: atom | {:global, term} | {:via, module, term}
 
   @typedoc "Options used by the `start*` functions"
-  @type options :: [option]
+  @type options :: [debug: debug,
+                    name: name,
+                    timeout: timeout,
+                    spawn_opt: Process.spawn_opt]
 
-  @typedoc "Option values used by the `start*` functions"
-  @type option :: {:debug, debug} |
-                  {:name, name} |
-                  {:timeout, timeout} |
-                  {:spawn_opt, Process.spawn_opt}
-
-  @typedoc "Debug options supported by the `start*` functions"
+  @typedoc "debug options supported by the `start*` functions"
   @type debug :: [:trace | :log | :statistics | {:log_to_file, Path.t}]
 
   @typedoc "The server reference"
   @type server :: pid | name | {atom, node}
 
-  @typedoc """
-  Tuple describing the client of a call request.
-
-  `pid` is the PID of the caller and `tag` is a unique term used to identify the
-  call.
-  """
-  @type from :: {pid, tag :: term}
-
   @doc false
-  defmacro __using__(opts) do
-    quote location: :keep, bind_quoted: [opts: opts] do
-      @behaviour GenServer
-
-      spec = [
-        id: opts[:id] || __MODULE__,
-        start: Macro.escape(opts[:start]) || quote(do: {__MODULE__, :start_link, [arg]}),
-        restart: opts[:restart] || :permanent,
-        shutdown: opts[:shutdown] || 5000,
-        type: :worker
-      ]
-
-      @doc false
-      def child_spec(arg) do
-        %{unquote_splicing(spec)}
-      end
-
-      defoverridable child_spec: 1
+  defmacro __using__(_) do
+    quote location: :keep do
+      @behaviour :gen_server
 
       @doc false
       def init(args) do
@@ -587,44 +233,17 @@ defmodule GenServer do
 
       @doc false
       def handle_call(msg, _from, state) do
-        proc =
-          case Process.info(self(), :registered_name) do
-            {_, []}   -> self()
-            {_, name} -> name
-          end
-
-        # We do this to trick Dialyzer to not complain about non-local returns.
-        case :erlang.phash2(1, 1) do
-          0 -> raise "attempted to call GenServer #{inspect proc} but no handle_call/3 clause was provided"
-          1 -> {:stop, {:bad_call, msg}, state}
-        end
+        {:stop, {:bad_call, msg}, state}
       end
 
       @doc false
-      def handle_info(msg, state) do
-        proc =
-          case Process.info(self(), :registered_name) do
-            {_, []}   -> self()
-            {_, name} -> name
-          end
-        :error_logger.error_msg('~p ~p received unexpected message in handle_info/2: ~p~n',
-                                [__MODULE__, proc, msg])
+      def handle_info(_msg, state) do
         {:noreply, state}
       end
 
       @doc false
       def handle_cast(msg, state) do
-        proc =
-          case Process.info(self(), :registered_name) do
-            {_, []}   -> self()
-            {_, name} -> name
-          end
-
-        # We do this to trick Dialyzer to not complain about non-local returns.
-        case :erlang.phash2(1, 1) do
-          0 -> raise "attempted to cast GenServer #{inspect proc} but no handle_cast/2 clause was provided"
-          1 -> {:stop, {:bad_cast, msg}, state}
-        end
+        {:stop, {:bad_cast, msg}, state}
       end
 
       @doc false
@@ -637,7 +256,8 @@ defmodule GenServer do
         {:ok, state}
       end
 
-      defoverridable GenServer
+      defoverridable [init: 1, handle_call: 3, handle_info: 2,
+                      handle_cast: 2, terminate: 2, code_change: 3]
     end
   end
 
@@ -646,40 +266,38 @@ defmodule GenServer do
 
   This is often used to start the `GenServer` as part of a supervision tree.
 
-  Once the server is started, the `c:init/1` function of the given `module` is
-  called with `args` as its arguments to initialize the server. To ensure a
-  synchronized start-up procedure, this function does not return until `c:init/1`
-  has returned.
+  Once the server is started, it calls the `init/1` function in the given `module`
+  passing the given `args` to initialize it. To ensure a synchronized start-up
+  procedure, this function does not return until `init/1` has returned.
 
   Note that a `GenServer` started with `start_link/3` is linked to the
-  parent process and will exit in case of crashes from the parent. The GenServer
-  will also exit due to the `:normal` reasons in case it is configured to trap
-  exits in the `c:init/1` callback.
+  parent process and will exit in case of crashes. The GenServer will also
+  exit due to the `:normal` reasons in case it is configured to trap exits
+  in the `init/1` callback.
 
   ## Options
 
-    * `:name` - used for name registration as described in the "Name
-      registration" section of the module documentation
+  The `:name` option is used for name registration as described in the module
+  documentation. If the option `:timeout` option is present, the server is
+  allowed to spend the given milliseconds initializing or it will be
+  terminated and the start function will return `{:error, :timeout}`.
 
-    * `:timeout` - if present, the server is allowed to spend the given amount of
-      milliseconds initializing or it will be terminated and the start function
-      will return `{:error, :timeout}`
+  If the `:debug` option is present, the corresponding function in the
+  [`:sys` module](http://www.erlang.org/doc/man/sys.html) will be invoked.
 
-    * `:debug` - if present, the corresponding function in the [`:sys` module](http://www.erlang.org/doc/man/sys.html) is invoked
-
-    * `:spawn_opt` - if present, its value is passed as options to the
-      underlying process as in `Process.spawn/4`
+  If the `:spawn_opt` option is present, its value will be passed as options
+  to the underlying process as in `Process.spawn/4`.
 
   ## Return values
 
-  If the server is successfully created and initialized, this function returns
-  `{:ok, pid}`, where `pid` is the PID of the server. If a process with the
-  specified server name already exists, this function returns
-  `{:error, {:already_started, pid}}` with the PID of that process.
+  If the server is successfully created and initialized, the function returns
+  `{:ok, pid}`, where pid is the pid of the server. If there already exists a
+  process with the specified server name, the function returns
+  `{:error, {:already_started, pid}}` with the pid of that process.
 
-  If the `c:init/1` callback fails with `reason`, this function returns
+  If the `init/1` callback fails with `reason`, the function returns
   `{:error, reason}`. Otherwise, if it returns `{:stop, reason}`
-  or `:ignore`, the process is terminated and this function returns
+  or `:ignore`, the process is terminated and the function returns
   `{:error, reason}` or `:ignore`, respectively.
   """
   @spec start_link(module, any, options) :: on_start
@@ -703,96 +321,58 @@ defmodule GenServer do
         :gen.start(:gen_server, link, module, args, opts)
       {atom, opts} when is_atom(atom) ->
         :gen.start(:gen_server, link, {:local, atom}, module, args, opts)
-      {{:global, _term} = tuple, opts} ->
-        :gen.start(:gen_server, link, tuple, module, args, opts)
-      {{:via, via_module, _term} = tuple, opts} when is_atom(via_module) ->
-        :gen.start(:gen_server, link, tuple, module, args, opts)
-      {other, _} ->
-        raise ArgumentError, """
-        expected :name option to be one of:
-
-          * nil
-          * atom
-          * {:global, term}
-          * {:via, module, term}
-
-        Got: #{inspect(other)}
-        """
+      {other, opts} when is_tuple(other) ->
+        :gen.start(:gen_server, link, other, module, args, opts)
     end
   end
 
-  @doc """
-  Synchronously stops the server with the given `reason`.
-
-  The `c:terminate/2` callback of the given `server` will be invoked before
-  exiting. This function returns `:ok` if the server terminates with the
-  given reason; if it terminates with another reason, the call exits.
-
-  This function keeps OTP semantics regarding error reporting.
-  If the reason is any other than `:normal`, `:shutdown` or
-  `{:shutdown, _}`, an error report is logged.
-  """
-  @spec stop(server, reason :: term, timeout) :: :ok
-  def stop(server, reason \\ :normal, timeout \\ :infinity) do
-    :gen.stop(server, reason, timeout)
-  end
-
   @doc """
   Makes a synchronous call to the `server` and waits for its reply.
 
   The client sends the given `request` to the server and waits until a reply
-  arrives or a timeout occurs. `c:handle_call/3` will be called on the server
+  arrives or a timeout occurs. `handle_call/3` will be called on the server
   to handle the request.
 
-  `server` can be any of the values described in the "Name registration"
-  section of the documentation for this module.
+  The server can be any of the values described in the `Name Registration`
+  section of the module documentation.
 
   ## Timeouts
 
-  `timeout` is an integer greater than zero which specifies how many
+  The `timeout` is an integer greater than zero which specifies how many
   milliseconds to wait for a reply, or the atom `:infinity` to wait
-  indefinitely. The default value is `5000`. If no reply is received within
-  the specified time, the function call fails and the caller exits. If the
-  caller catches the failure and continues running, and the server is just late
-  with the reply, it may arrive at any time later into the caller's message
-  queue. The caller must in this case be prepared for this and discard any such
-  garbage messages that are two-element tuples with a reference as the first
-  element.
+  indefinitely. The default value is 5000. If no reply is received within
+  the specified time, the function call fails. If the caller catches the
+  failure and continues running, and the server is just late with the reply,
+  it may arrive at any time later into the caller's message queue. The caller
+  must in this case be prepared for this and discard any such garbage messages
+  that are two element tuples with a reference as the first element.
   """
   @spec call(server, term, timeout) :: term
   def call(server, request, timeout \\ 5000) do
-    case whereis(server) do
-      nil ->
-        exit({:noproc, {__MODULE__, :call, [server, request, timeout]}})
-      pid when pid == self() ->
-        exit({:calling_self, {__MODULE__, :call, [server, request, timeout]}})
-      pid ->
-        try do
-          :gen.call(pid, :"$gen_call", request, timeout)
-        catch
-          :exit, reason ->
-            exit({reason, {__MODULE__, :call, [server, request, timeout]}})
-        else
-          {:ok, res} -> res
-        end
+    try do
+      :gen.call(server, :"$gen_call", request, timeout)
+    catch
+      :exit, reason ->
+        exit({reason, {__MODULE__, :call, [server, request, timeout]}})
+    else
+      {:ok, res} -> res
     end
   end
 
   @doc """
   Sends an asynchronous request to the `server`.
 
-  This function always returns `:ok` regardless of whether
-  the destination `server` (or node) exists. Therefore it
-  is unknown whether the destination `server` successfully
-  handled the message.
+  This function returns `:ok` immediately, regardless of
+  whether the destination node or server does exists, unless
+  the server is specified as an atom.
 
-  `c:handle_cast/2` will be called on the server to handle
-  the request. In case the `server` is on a node which is
-  not yet connected to the caller one, the call is going to
+  `handle_cast/2` will be called on the server to handle
+  the request. In case the server is a node which is not
+  yet connected to the caller one, the call is going to
   block until a connection happens. This is different than
   the behaviour in OTP's `:gen_server` where the message
-  is sent by another process in this case, which could cause
-  messages to other nodes to arrive out of order.
+  would be sent by another process, which could cause
+  messages to arrive out of order.
   """
   @spec cast(server, term) :: :ok
   def cast(server, request)
@@ -824,13 +404,13 @@ defmodule GenServer do
   @doc """
   Casts all servers locally registered as `name` at the specified nodes.
 
-  This function returns immediately and ignores nodes that do not exist, or where the
+  The function returns immediately and ignores nodes that do not exist, or where the
   server name does not exist.
 
   See `multi_call/4` for more information.
   """
   @spec abcast([node], name :: atom, term) :: :abcast
-  def abcast(nodes \\ [node() | Node.list()], name, request) when is_list(nodes) and is_atom(name) do
+  def abcast(nodes \\ nodes(), name, request) when is_list(nodes) and is_atom(name) do
     msg = cast_msg(request)
     _   = for node <- nodes, do: do_send({name, node}, msg)
     :abcast
@@ -841,83 +421,49 @@ defmodule GenServer do
   end
 
   defp do_send(dest, msg) do
-    try do
-      send(dest, msg)
-      :ok
-    catch
-      _, _ -> :ok
-    end
+    send(dest, msg)
+    :ok
   end
 
   @doc """
   Calls all servers locally registered as `name` at the specified `nodes`.
 
-  First, the `request` is sent to every node in `nodes`; then, the caller waits
-  for the replies. This function returns a two-element tuple `{replies,
-  bad_nodes}` where:
+  The `request` is first sent to every node and then we wait for the
+  replies. This function returns a tuple containing the node and its reply
+  as first element and all bad nodes as second element. The bad nodes is a
+  list of nodes that either did not exist, or where a server with the given
+  `name` did not exist or did not reply.
 
-    * `replies` - is a list of `{node, reply}` tuples where `node` is the node
-      that replied and `reply` is its reply
-    * `bad_nodes` - is a list of nodes that either did not exist or where a
-      server with the given `name` did not exist or did not reply
-
-  `nodes` is a list of node names to which the request is sent. The default
-  value is the list of all known nodes (including this node).
+  Nodes is a list of node names to which the request is sent. The default
+  value is the list of all known nodes.
 
   To avoid that late answers (after the timeout) pollute the caller's message
   queue, a middleman process is used to do the actual calls. Late answers will
   then be discarded when they arrive to a terminated process.
-
-  ## Examples
-
-  Assuming the `Stack` GenServer mentioned in the docs for the `GenServer`
-  module is registered as `Stack` in the `:"foo@my-machine"` and
-  `:"bar@my-machine"` nodes:
-
-      GenServer.multi_call(Stack, :pop)
-      #=> {[{:"foo@my-machine", :hello}, {:"bar@my-machine", :world}], []}
-
   """
   @spec multi_call([node], name :: atom, term, timeout) ::
                   {replies :: [{node, term}], bad_nodes :: [node]}
-  def multi_call(nodes \\ [node() | Node.list()], name, request, timeout \\ :infinity) do
+  def multi_call(nodes \\ nodes(), name, request, timeout \\ :infinity) do
     :gen_server.multi_call(nodes, name, request, timeout)
   end
 
   @doc """
   Replies to a client.
 
-  This function can be used to explicitly send a reply to a client that called
-  `call/3` or `multi_call/4` when the reply cannot be specified in the return
-  value of `c:handle_call/3`.
+  This function can be used by a server to explicitly send a reply to a
+  client that called `call/3` or `multi_call/4`. When the reply cannot be
+  defined in the return value of `handle_call/3`.
 
-  `client` must be the `from` argument (the second argument) accepted by
-  `c:handle_call/3` callbacks. `reply` is an arbitrary term which will be given
-  back to the client as the return value of the call.
-
-  Note that `reply/2` can be called from any process, not just the GenServer
-  that originally received the call (as long as that GenServer communicated the
-  `from` argument somehow).
+  The `client` must be the `from` argument (the second argument) received
+  in `handle_call/3` callbacks. Reply is an arbitrary term which will be
+  given back to the client as the return value of the call.
 
   This function always returns `:ok`.
-
-  ## Examples
-
-      def handle_call(:reply_in_one_second, from, state) do
-        Process.send_after(self(), {:reply, from}, 1_000)
-        {:noreply, state}
-      end
-
-      def handle_info({:reply, from}, state) do
-        GenServer.reply(from, :one_second_has_passed)
-        {:noreply, state}
-      end
-
   """
-  @spec reply(from, term) :: :ok
+  @spec reply({pid, reference}, term) :: :ok
   def reply(client, reply)
 
-  def reply({to, tag}, reply) when is_pid(to) do
+  def reply({to, tag}, reply) do
     try do
       send(to, {tag, reply})
       :ok
@@ -926,47 +472,9 @@ defmodule GenServer do
     end
   end
 
-  @doc """
-  Returns the `pid` or `{name, node}` of a GenServer process, or `nil` if
-  no process is associated with the given `server`.
+  @compile {:inline, [nodes: 0]}
 
-  ## Examples
-
-  For example, to lookup a server process, monitor it and send a cast to it:
-
-      process = GenServer.whereis(server)
-      monitor = Process.monitor(process)
-      GenServer.cast(process, :hello)
-
-  """
-  @spec whereis(server) :: pid | {atom, node} | nil
-  def whereis(server)
-
-  def whereis(pid) when is_pid(pid), do: pid
-
-  def whereis(name) when is_atom(name) do
-    Process.whereis(name)
-  end
-
-  def whereis({:global, name}) do
-    case :global.whereis_name(name) do
-      pid when is_pid(pid) -> pid
-      :undefined           -> nil
-    end
-  end
-
-  def whereis({:via, mod, name}) do
-    case apply(mod, :whereis_name, [name]) do
-      pid when is_pid(pid) -> pid
-      :undefined           -> nil
-    end
-  end
-
-  def whereis({name, local}) when is_atom(name) and local == node() do
-    Process.whereis(name)
-  end
-
-  def whereis({name, node} = server) when is_atom(name) and is_atom(node) do
-    server
+  defp nodes do
+    [node()|:erlang.nodes()]
   end
 end

lib/elixir/lib/hash_dict.ex

@@ -1,13 +1,19 @@
 defmodule HashDict do
   @moduledoc """
-  WARNING: this module is deprecated.
+  A key-value store.
 
-  Use the `Map` module instead.
+  The `HashDict` is represented internally as a struct, therefore
+  `%HashDict{}` can be used whenever there is a need to match
+  on any `HashDict`. Note though the struct fields are private and
+  must not be accessed directly. Instead, use the functions on this
+  or in the `Dict` module.
+
+  Implementation-wise, `HashDict` is implemented using tries, which
+  grows in space as the number of keys grows, working well with both
+  small and large set of keys. For more information about the
+  functions and their APIs, please consult the `Dict` module.
   """
 
-  # TODO: Remove by 2.0
-  # (hard-deprecated in elixir_dispatch)
-
   use Dict
 
   @node_bitmap 0b111
@@ -93,7 +99,7 @@ defmodule HashDict do
   defp do_fetch(node, key, hash) do
     index = key_mask(hash)
     case elem(node, index) do
-      [^key | v]   -> {:ok, v}
+      [^key|v]     -> {:ok, v}
       {^key, v, _} -> {:ok, v}
       {_, _, n}    -> do_fetch(n, key, key_shift(hash))
       _            -> :error
@@ -104,11 +110,11 @@ defmodule HashDict do
     index = key_mask(hash)
     case elem(node, index) do
       [] ->
-        {put_elem(node, index, [key | value]), 1}
-      [^key | _] ->
-        {put_elem(node, index, [key | value]), 0}
-      [k | v] ->
-        n = put_elem(@node_template, key_mask(key_shift(hash)), [key | value])
+        {put_elem(node, index, [key|value]), 1}
+      [^key|_] ->
+        {put_elem(node, index, [key|value]), 0}
+      [k|v] ->
+        n = put_elem(@node_template, key_mask(key_shift(hash)), [key|value])
         {put_elem(node, index, {k, v, n}), 1}
       {^key, _, n} ->
         {put_elem(node, index, {key, value, n}), 0}
@@ -122,11 +128,11 @@ defmodule HashDict do
     index = key_mask(hash)
     case elem(node, index) do
       [] ->
-        {put_elem(node, index, [key | initial.()]), 1}
-      [^key | value] ->
-        {put_elem(node, index, [key | fun.(value)]), 0}
-      [k | v] ->
-        n = put_elem(@node_template, key_mask(key_shift(hash)), [key | initial.()])
+        {put_elem(node, index, [key|initial.()]), 1}
+      [^key|value] ->
+        {put_elem(node, index, [key|fun.(value)]), 0}
+      [k|v] ->
+        n = put_elem(@node_template, key_mask(key_shift(hash)), [key|initial.()])
         {put_elem(node, index, {k, v, n}), 1}
       {^key, value, n} ->
         {put_elem(node, index, {key, fun.(value), n}), 0}
@@ -141,16 +147,16 @@ defmodule HashDict do
     case elem(node, index) do
       [] ->
         :error
-      [^key | value] ->
+      [^key|value] ->
         {put_elem(node, index, []), value}
-      [_ | _] ->
+      [_|_] ->
         :error
       {^key, value, n} ->
         {put_elem(node, index, do_compact_node(n)), value}
       {k, v, n} ->
         case do_delete(n, key, key_shift(hash)) do
           {@node_template, value} ->
-            {put_elem(node, index, [k | v]), value}
+            {put_elem(node, index, [k|v]), value}
           {n, value} ->
             {put_elem(node, index, {k, v, n}), value}
           :error ->
@@ -162,9 +168,9 @@ defmodule HashDict do
   Enum.each 0..(@node_size - 1), fn index ->
     defp do_compact_node(node) when elem(node, unquote(index)) != [] do
       case elem(node, unquote(index)) do
-        [k | v] ->
+        [k|v] ->
           case put_elem(node, unquote(index), []) do
-            @node_template -> [k | v]
+            @node_template -> [k|v]
             n -> {k, v, n}
           end
         {k, v, n} ->
@@ -187,8 +193,8 @@ defmodule HashDict do
     next.(acc)
   end
 
-  defp do_reduce_each([k | v], {:cont, acc}, fun, next) do
-    next.(fun.({k, v}, acc))
+  defp do_reduce_each([k|v], {:cont, acc}, fun, next) do
+    next.(fun.({k,v}, acc))
   end
 
   defp do_reduce_each({k, v, n}, {:cont, acc}, fun, next) do
@@ -221,35 +227,31 @@ defmodule HashDict do
 end
 
 defimpl Enumerable, for: HashDict do
-  def reduce(dict, acc, fun) do
-    # Avoid warnings about HashDict being deprecated.
-    module = HashDict
-    module.reduce(dict, acc, fun)
+  def reduce(dict, acc, fun),  do: HashDict.reduce(dict, acc, fun)
+  def member?(dict, {k, v}), do: {:ok, match?({:ok, ^v}, HashDict.fetch(dict, k))}
+  def member?(_dict, _),       do: {:ok, false}
+  def count(dict),             do: {:ok, HashDict.size(dict)}
+end
+
+defimpl Access, for: HashDict do
+  def get(dict, key) do
+    HashDict.get(dict, key, nil)
   end
 
-  def member?(dict, {key, value}) do
-    # Avoid warnings about HashDict being deprecated.
-    module = HashDict
-    {:ok, match?({:ok, ^value}, module.fetch(dict, key))}
-  end
-
-  def member?(_dict, _) do
-    {:ok, false}
-  end
-
-  def count(dict) do
-    # Avoid warnings about HashDict being deprecated.
-    module = HashDict
-    {:ok, module.size(dict)}
+  def get_and_update(dict, key, fun) do
+    {get, update} = fun.(HashDict.get(dict, key, nil))
+    {get, HashDict.put(dict, key, update)}
   end
 end
 
 defimpl Collectable, for: HashDict do
+  def empty(_dict) do
+    HashDict.new
+  end
+
   def into(original) do
-    # Avoid warnings about HashDict being deprecated.
-    module = HashDict
     {original, fn
-      dict, {:cont, {key, value}} -> module.put(dict, key, value)
+      dict, {:cont, {k, v}} -> Dict.put(dict, k, v)
       dict, :done -> dict
       _, :halt -> :ok
     end}
@@ -260,8 +262,6 @@ defimpl Inspect, for: HashDict do
   import Inspect.Algebra
 
   def inspect(dict, opts) do
-    # Avoid warnings about HashDict being deprecated.
-    module = HashDict
-    concat ["#HashDict<", Inspect.List.inspect(module.to_list(dict), opts), ">"]
+    concat ["#HashDict<", Inspect.List.inspect(HashDict.to_list(dict), opts), ">"]
   end
 end

lib/elixir/lib/hash_set.ex

@@ -1,12 +1,20 @@
 defmodule HashSet do
   @moduledoc """
-  WARNING: this module is deprecated.
+  A set store.
 
-  Use the `MapSet` module instead.
+  The `HashSet` is represented internally as a struct, therefore
+  `%HashSet{}` can be used whenever there is a need to match
+  on any `HashSet`. Note though the struct fields are private and
+  must not be accessed directly. Instead, use the functions on this
+  or in the `Set` module.
+
+  The `HashSet` is implemented using tries, which grows in
+  space as the number of keys grows, working well with both
+  small and large set of keys. For more information about the
+  functions and their APIs, please consult the `Set` module.
   """
 
-  # TODO: Remove by 2.0
-  # (hard-deprecated in elixir_dispatch)
+  @behaviour Set
 
   @node_bitmap 0b111
   @node_shift 3
@@ -21,6 +29,9 @@ defmodule HashSet do
   @compile :inline_list_funcs
   @compile {:inline, key_hash: 1, key_mask: 1, key_shift: 1}
 
+  @doc """
+  Creates a new empty set.
+  """
   @spec new :: Set.t
   def new do
     %HashSet{}
@@ -45,7 +56,7 @@ defmodule HashSet do
   end
 
   def to_list(set) do
-    set_fold(set, [], &[&1 | &2]) |> :lists.reverse
+    set_fold(set, [], &[&1|&2]) |> :lists.reverse
   end
 
   def equal?(%HashSet{size: size1} = set1, %HashSet{size: size2} = set2) do
@@ -113,10 +124,10 @@ defmodule HashSet do
   defp do_member?(node, term, hash) do
     index = key_mask(hash)
     case elem(node, index) do
-      []          -> false
-      [^term | _] -> true
-      [_]         -> false
-      [_ | n]     -> do_member?(n, term, key_shift(hash))
+      []        -> false
+      [^term|_] -> true
+      [_]       -> false
+      [_|n]     -> do_member?(n, term, key_shift(hash))
     end
   end
 
@@ -125,14 +136,14 @@ defmodule HashSet do
     case elem(node, index) do
       [] ->
         {put_elem(node, index, [term]), 1}
-      [^term | _] ->
+      [^term|_] ->
         {node, 0}
       [t] ->
         n = put_elem(@node_template, key_mask(key_shift(hash)), [term])
-        {put_elem(node, index, [t | n]), 1}
-      [t | n] ->
+        {put_elem(node, index, [t|n]), 1}
+      [t|n] ->
         {n, counter} = do_put(n, term, key_shift(hash))
-        {put_elem(node, index, [t | n]), counter}
+        {put_elem(node, index, [t|n]), counter}
     end
   end
 
@@ -145,14 +156,14 @@ defmodule HashSet do
         {:ok, put_elem(node, index, [])}
       [_] ->
         :error
-      [^term | n] ->
+      [^term|n] ->
         {:ok, put_elem(node, index, do_compact_node(n))}
-      [t | n] ->
+      [t|n] ->
         case do_delete(n, term, key_shift(hash)) do
           {:ok, @node_template} ->
             {:ok, put_elem(node, index, [t])}
           {:ok, n} ->
-            {:ok, put_elem(node, index, [t | n])}
+            {:ok, put_elem(node, index, [t|n])}
           :error ->
             :error
         end
@@ -165,19 +176,19 @@ defmodule HashSet do
         [t] ->
           case put_elem(node, unquote(index), []) do
             @node_template -> [t]
-            n -> [t | n]
+            n -> [t|n]
           end
-        [t | n] ->
-          [t | put_elem(node, unquote(index), do_compact_node(n))]
+        [t|n] ->
+          [t|put_elem(node, unquote(index), do_compact_node(n))]
       end
     end
   end
 
   ## Set fold
 
-  defp do_fold_each([], acc, _fun),     do: acc
-  defp do_fold_each([t], acc, fun),     do: fun.(t, acc)
-  defp do_fold_each([t | n], acc, fun), do: do_fold(n, fun.(t, acc), fun, @node_size)
+  defp do_fold_each([], acc, _fun),   do: acc
+  defp do_fold_each([t], acc, fun),   do: fun.(t, acc)
+  defp do_fold_each([t|n], acc, fun), do: do_fold(n, fun.(t, acc), fun, @node_size)
 
   defp do_fold(node, acc, fun, count) when count > 0 do
     acc = do_fold_each(:erlang.element(count, node), acc, fun)
@@ -206,7 +217,7 @@ defmodule HashSet do
     next.(fun.(t, acc))
   end
 
-  defp do_reduce_each([t | n], {:cont, acc}, fun, next) do
+  defp do_reduce_each([t|n], {:cont, acc}, fun, next) do
     do_reduce(n, fun.(t, acc), fun, @node_size, next)
   end
 
@@ -236,31 +247,19 @@ defmodule HashSet do
 end
 
 defimpl Enumerable, for: HashSet do
-  def reduce(set, acc, fun) do
-    # Avoid warnings about HashSet being deprecated.
-    module = HashSet
-    module.reduce(set, acc, fun)
-  end
-
-  def member?(set, term) do
-    # Avoid warnings about HashSet being deprecated.
-    module = HashSet
-    {:ok, module.member?(set, term)}
-  end
-
-  def count(set) do
-    # Avoid warnings about HashSet being deprecated.
-    module = HashSet
-    {:ok, module.size(set)}
-  end
+  def reduce(set, acc, fun), do: HashSet.reduce(set, acc, fun)
+  def member?(set, v),       do: {:ok, HashSet.member?(set, v)}
+  def count(set),            do: {:ok, HashSet.size(set)}
 end
 
 defimpl Collectable, for: HashSet do
+  def empty(_dict) do
+    HashSet.new
+  end
+
   def into(original) do
-    # Avoid warnings about HashSet being deprecated.
-    module = HashSet
     {original, fn
-      set, {:cont, term} -> module.put(set, term)
+      set, {:cont, x} -> HashSet.put(set, x)
       set, :done -> set
       _, :halt -> :ok
     end}
@@ -271,8 +270,6 @@ defimpl Inspect, for: HashSet do
   import Inspect.Algebra
 
   def inspect(set, opts) do
-    # Avoid warnings about HashSet being deprecated.
-    module = HashSet
-    concat ["#HashSet<", Inspect.List.inspect(module.to_list(set), opts), ">"]
+    concat ["#HashSet<", Inspect.List.inspect(HashSet.to_list(set), opts), ">"]
   end
 end

lib/elixir/lib/inspect.ex

@@ -16,20 +16,20 @@ defprotocol Inspect do
   ## Examples
 
   Many times, inspecting a structure can be implemented in function
-  of existing entities. For example, here is `MapSet`'s `inspect`
+  of existing entities. For example, here is `HashSet`'s `inspect`
   implementation:
 
-      defimpl Inspect, for: MapSet do
+      defimpl Inspect, for: HashSet do
         import Inspect.Algebra
 
         def inspect(dict, opts) do
-          concat ["#MapSet<", to_doc(MapSet.to_list(dict), opts), ">"]
+          concat ["#HashSet<", to_doc(HashSet.to_list(dict), opts), ">"]
         end
       end
 
-  The `concat/1` function comes from `Inspect.Algebra` and it
+  The `concat` function comes from `Inspect.Algebra` and it
   concatenates algebra documents together. In the example above,
-  it is concatenating the string `"MapSet<"` (all strings are
+  it is concatenating the string `"HashSet<"` (all strings are
   valid algebra documents that keep their formatting when pretty
   printed), the document returned by `Inspect.Algebra.to_doc/2` and the
   other string `">"`.
@@ -41,263 +41,258 @@ defprotocol Inspect do
   ## Error handling
 
   In case there is an error while your structure is being inspected,
-  Elixir will raise an `ArgumentError` error and will automatically fall back
-  to a raw representation for printing the structure.
+  Elixir will automatically fall back to a raw representation.
 
   You can however access the underlying error by invoking the Inspect
-  implementation directly. For example, to test Inspect.MapSet above,
+  implementation directly. For example, to test Inspect.HashSet above,
   you can invoke it as:
 
-      Inspect.MapSet.inspect(MapSet.new, %Inspect.Opts{})
+      Inspect.HashSet.inspect(HashSet.new, Inspect.Opts.new)
 
   """
 
   # Handle structs in Any
   @fallback_to_any true
 
-  def inspect(term, opts)
+  def inspect(thing, opts)
 end
 
 defimpl Inspect, for: Atom do
   require Macro
 
-  def inspect(atom, opts) do
-    color(inspect(atom), color_key(atom), opts)
+  def inspect(atom, _opts) do
+    inspect(atom)
   end
 
-  defp color_key(atom) when is_boolean(atom), do: :boolean
-  defp color_key(nil), do: :nil
-  defp color_key(_), do: :atom
+  def inspect(false),  do: "false"
+  def inspect(true),   do: "true"
+  def inspect(nil),    do: "nil"
+  def inspect(:""),    do: ":\"\""
 
-  def inspect(atom) when is_nil(atom) or is_boolean(atom) do
-    Atom.to_string(atom)
-  end
-
-  def inspect(atom) when is_atom(atom) do
+  def inspect(atom) do
     binary = Atom.to_string(atom)
 
-    case Macro.classify_identifier(atom) do
-      :alias ->
-        case binary do
-          binary when binary in ["Elixir", "Elixir.Elixir"] ->
-            binary
-          "Elixir.Elixir." <> _rest ->
-            binary
-          "Elixir." <> rest ->
-            rest
+    cond do
+      valid_ref_identifier?(binary) ->
+        if only_elixir?(binary) do
+          binary
+        else
+          "Elixir." <> rest = binary
+          rest
         end
-      type when type in [:callable, :not_callable] ->
+      valid_atom_identifier?(binary) ->
         ":" <> binary
-      :other ->
-        {escaped, _} = Inspect.BitString.escape(binary, ?")
-        IO.iodata_to_binary [?:, ?", escaped, ?"]
+      atom in [:%{}, :{}, :<<>>, :..., :%] ->
+        ":" <> binary
+      atom in Macro.binary_ops or atom in Macro.unary_ops ->
+        ":" <> binary
+      true ->
+        << ?:, ?", Inspect.BitString.escape(binary, ?") :: binary, ?" >>
     end
   end
+
+  defp only_elixir?("Elixir." <> rest), do: only_elixir?(rest)
+  defp only_elixir?("Elixir"), do: true
+  defp only_elixir?(_), do: false
+
+  # Detect if atom is an atom alias (Elixir.Foo.Bar.Baz)
+
+  defp valid_ref_identifier?("Elixir" <> rest) do
+    valid_ref_piece?(rest)
+  end
+
+  defp valid_ref_identifier?(_), do: false
+
+  defp valid_ref_piece?(<<?., h, t :: binary>>) when h in ?A..?Z do
+    valid_ref_piece? valid_identifier?(t)
+  end
+
+  defp valid_ref_piece?(<<>>), do: true
+  defp valid_ref_piece?(_),    do: false
+
+  # Detect if atom
+
+  defp valid_atom_identifier?(<<h, t :: binary>>) when h in ?a..?z or h in ?A..?Z or h == ?_ do
+    valid_atom_piece?(t)
+  end
+
+  defp valid_atom_identifier?(_), do: false
+
+  defp valid_atom_piece?(t) do
+    case valid_identifier?(t) do
+      <<>>              -> true
+      <<??>>            -> true
+      <<?!>>            -> true
+      <<?@, t::binary>> -> valid_atom_piece?(t)
+      _                 -> false
+    end
+  end
+
+  defp valid_identifier?(<<h, t :: binary>>)
+      when h in ?a..?z
+      when h in ?A..?Z
+      when h in ?0..?9
+      when h == ?_ do
+    valid_identifier? t
+  end
+
+  defp valid_identifier?(other), do: other
 end
 
 defimpl Inspect, for: BitString do
-  def inspect(term, opts) when is_binary(term) do
-    %Inspect.Opts{binaries: bins, base: base, printable_limit: printable_limit} = opts
-
-    if base == :decimal and
-       (bins == :as_strings or (bins == :infer and String.printable?(term, printable_limit))) do
-      inspected =
-        case escape(term, ?", printable_limit) do
-          {escaped, ""} -> [?", escaped, ?"]
-          {escaped, _} -> [?", escaped, ?", " <> ..."]
-        end
-      color(IO.iodata_to_binary(inspected), :string, opts)
+  def inspect(thing, %Inspect.Opts{binaries: bins} = opts) when is_binary(thing) do
+    if bins == :as_strings or (bins == :infer and String.printable?(thing)) do
+      <<?", escape(thing, ?") :: binary, ?">>
     else
-      inspect_bitstring(term, opts)
+      inspect_bitstring(thing, opts)
     end
   end
 
-  def inspect(term, opts) do
-    inspect_bitstring(term, opts)
+  def inspect(thing, opts) do
+    inspect_bitstring(thing, opts)
   end
 
   ## Escaping
 
   @doc false
   def escape(other, char) do
-    escape(other, char, :infinity, [])
+    escape(other, char, <<>>)
   end
 
-  @doc false
-  def escape(other, char, count) do
-    escape(other, char, count, [])
+  defp escape(<< char, t :: binary >>, char, binary) do
+    escape(t, char, << binary :: binary, ?\\, char >>)
   end
-
-  defp escape(<<_, _::binary>> = binary, _char, 0, acc) do
-    {acc, binary}
+  defp escape(<<?#, ?{, t :: binary>>, char, binary) do
+    escape(t, char, << binary :: binary, ?\\, ?#, ?{>>)
   end
-  defp escape(<<char, t::binary>>, char, count, acc) do
-    escape(t, char, decrement(count), [acc | [?\\, char]])
+  defp escape(<<?\a, t :: binary>>, char, binary) do
+    escape(t, char, << binary :: binary, ?\\, ?a >>)
   end
-  defp escape(<<?#, ?{, t::binary>>, char, count, acc) do
-    escape(t, char, decrement(count), [acc | '\\\#{'])
+  defp escape(<<?\b, t :: binary>>, char, binary) do
+    escape(t, char, << binary :: binary, ?\\, ?b >>)
   end
-  defp escape(<<?\a, t::binary>>, char, count, acc) do
-    escape(t, char, decrement(count), [acc | '\\a'])
+  defp escape(<<?\d, t :: binary>>, char, binary) do
+    escape(t, char, << binary :: binary, ?\\, ?d >>)
   end
-  defp escape(<<?\b, t::binary>>, char, count, acc) do
-    escape(t, char, decrement(count), [acc | '\\b'])
+  defp escape(<<?\e, t :: binary>>, char, binary) do
+    escape(t, char, << binary :: binary, ?\\, ?e >>)
   end
-  defp escape(<<?\d, t::binary>>, char, count, acc) do
-    escape(t, char, decrement(count), [acc | '\\d'])
+  defp escape(<<?\f, t :: binary>>, char, binary) do
+    escape(t, char, << binary :: binary, ?\\, ?f >>)
   end
-  defp escape(<<?\e, t::binary>>, char, count, acc) do
-    escape(t, char, decrement(count), [acc | '\\e'])
+  defp escape(<<?\n, t :: binary>>, char, binary) do
+    escape(t, char, << binary :: binary, ?\\, ?n >>)
   end
-  defp escape(<<?\f, t::binary>>, char, count, acc) do
-    escape(t, char, decrement(count), [acc | '\\f'])
+  defp escape(<<?\r, t :: binary>>, char, binary) do
+    escape(t, char, << binary :: binary, ?\\, ?r >>)
   end
-  defp escape(<<?\n, t::binary>>, char, count, acc) do
-    escape(t, char, decrement(count), [acc | '\\n'])
+  defp escape(<<?\\, t :: binary>>, char, binary) do
+    escape(t, char, << binary :: binary, ?\\, ?\\ >>)
   end
-  defp escape(<<?\r, t::binary>>, char, count, acc) do
-    escape(t, char, decrement(count), [acc | '\\r'])
+  defp escape(<<?\t, t :: binary>>, char, binary) do
+    escape(t, char, << binary :: binary, ?\\, ?t >>)
   end
-  defp escape(<<?\\, t::binary>>, char, count, acc) do
-    escape(t, char, decrement(count), [acc | '\\\\'])
+  defp escape(<<?\v, t :: binary>>, char, binary) do
+    escape(t, char, << binary :: binary, ?\\, ?v >>)
   end
-  defp escape(<<?\t, t::binary>>, char, count, acc) do
-    escape(t, char, decrement(count), [acc | '\\t'])
+  defp escape(<<h :: utf8, t :: binary>>, char, binary) do
+    head = << h :: utf8 >>
+    if String.printable?(head) do
+      escape(t, char, append(head, binary))
+    else
+      << byte :: size(8), h :: binary >> = head
+      t = << h :: binary, t :: binary >>
+      escape(t, char, << binary :: binary, escape_char(byte) :: binary >>)
+    end
   end
-  defp escape(<<?\v, t::binary>>, char, count, acc) do
-    escape(t, char, decrement(count), [acc | '\\v'])
-  end
-  defp escape(<<h::utf8, t::binary>>, char, count, acc)
-       when h in 0x20..0x7E
-       when h in 0xA0..0xD7FF
-       when h in 0xE000..0xFFFD
-       when h in 0x10000..0x10FFFF do
-    escape(t, char, decrement(count), [acc | <<h::utf8>>])
-  end
-  defp escape(<<h, t::binary>>, char, count, acc) do
-    escape(t, char, decrement(count), [acc | escape_char(h)])
-  end
-  defp escape(<<>>, _char, _count, acc) do
-    {acc, <<>>}
+  defp escape(<<h, t :: binary>>, char, binary) do
+    escape(t, char, << binary :: binary, escape_char(h) :: binary >>)
   end
+  defp escape(<<>>, _char, binary), do: binary
 
   @doc false
   # Also used by Regex
   def escape_char(0) do
-    '\\0'
+    <<?\\, ?0>>
   end
 
   def escape_char(char) when char < 0x100 do
-    <<a::4, b::4>> = <<char::8>>
-    ['\\x', to_hex(a), to_hex(b)]
+    <<a::4, b::4>> = <<char::size(8)>>
+    <<?\\, ?x, to_hex(a), to_hex(b)>>
   end
 
   def escape_char(char) when char < 0x10000 do
-    <<a::4, b::4, c::4, d::4>> = <<char::16>>
-    ['\\x{', to_hex(a), to_hex(b), to_hex(c), to_hex(d), ?}]
+    <<a::4, b::4, c::4, d::4>> = <<char::size(16)>>
+    <<?\\, ?x, ?{, to_hex(a), to_hex(b), to_hex(c), to_hex(d), ?}>>
   end
 
   def escape_char(char) when char < 0x1000000 do
-    <<a::4, b::4, c::4, d::4, e::4, f::4>> = <<char::24>>
-    ['\\x{', to_hex(a), to_hex(b), to_hex(c),
-             to_hex(d), to_hex(e), to_hex(f), ?}]
+    <<a::4, b::4, c::4, d::4, e::4, f::4>> = <<char::size(24)>>
+    <<?\\, ?x, ?{, to_hex(a), to_hex(b), to_hex(c),
+                   to_hex(d), to_hex(e), to_hex(f), ?}>>
   end
 
-  defp to_hex(c) when c in 0..9, do: ?0 + c
-  defp to_hex(c) when c in 10..15, do: ?A + c - 10
+  defp to_hex(c) when c in 0..9, do: ?0+c
+  defp to_hex(c) when c in 10..15, do: ?A+c-10
+
+  defp append(<<h, t :: binary>>, binary), do: append(t, << binary :: binary, h >>)
+  defp append(<<>>, binary), do: binary
 
   ## Bitstrings
 
-  defp inspect_bitstring("", opts) do
-    color("<<>>", :binary, opts)
-  end
-
   defp inspect_bitstring(bitstring, opts) do
-    left = color("<<", :binary, opts)
-    right = color(">>", :binary, opts)
-    nest surround(left, each_bit(bitstring, opts.limit, opts), right), 1
+    each_bit(bitstring, opts.limit, "<<") <> ">>"
   end
 
-  defp each_bit(_, 0, _) do
-    "..."
+  defp each_bit(_, 0, acc) do
+    acc <> "..."
   end
 
-  defp each_bit(<<>>, _counter, _opts) do
-    :doc_nil
+  defp each_bit(<<h, t :: bitstring>>, counter, acc) when t != <<>> do
+    each_bit(t, decrement(counter), acc <> Integer.to_string(h) <> ", ")
   end
 
-  defp each_bit(<<h::8>>, _counter, opts) do
-    Inspect.Integer.inspect(h, opts)
+  defp each_bit(<<h :: size(8)>>, _counter, acc) do
+    acc <> Integer.to_string(h)
   end
 
-  defp each_bit(<<h, t::bitstring>>, counter, opts) do
-    glue(concat(Inspect.Integer.inspect(h, opts), ","),
-         each_bit(t, decrement(counter), opts))
+  defp each_bit(<<>>, _counter, acc) do
+    acc
   end
 
-  defp each_bit(bitstring, _counter, opts) do
+  defp each_bit(bitstring, _counter, acc) do
     size = bit_size(bitstring)
-    <<h::size(size)>> = bitstring
-    Inspect.Integer.inspect(h, opts) <> "::size(" <> Integer.to_string(size) <> ")"
+    <<h :: size(size)>> = bitstring
+    acc <> Integer.to_string(h) <> "::size(" <> Integer.to_string(size) <> ")"
   end
 
-  @compile {:inline, decrement: 1}
   defp decrement(:infinity), do: :infinity
   defp decrement(counter),   do: counter - 1
 end
 
 defimpl Inspect, for: List do
-  def inspect([], opts) do
-    color("[]", :list, opts)
-  end
-
-  # TODO: Remove :char_list and :as_char_lists handling in 2.0
-  def inspect(term, opts) do
-    %Inspect.Opts{charlists: lists, char_lists: lists_deprecated, printable_limit: printable_limit} = opts
-    lists =
-      if lists == :infer and lists_deprecated != :infer do
-        case lists_deprecated do
-          :as_char_lists ->
-            IO.warn "the :char_lists inspect option and its :as_char_lists " <>
-              "value are deprecated, use the :charlists option and its " <>
-              ":as_charlists value instead"
-            :as_charlists
-          _ ->
-            IO.warn "the :char_lists inspect option is deprecated, use :charlists instead"
-            lists_deprecated
-        end
-      else
-        lists
-      end
-
-    open = color("[", :list, opts)
-    sep = color(",", :list, opts)
-    close = color("]", :list, opts)
+  def inspect([], _opts), do: "[]"
 
+  def inspect(thing, %Inspect.Opts{char_lists: lists} = opts) do
     cond do
-      lists == :as_charlists or (lists == :infer and printable?(term, printable_limit)) ->
-        inspected =
-          case Inspect.BitString.escape(IO.chardata_to_string(term), ?', printable_limit) do
-            {escaped, ""} -> [?', escaped, ?']
-            {escaped, _} -> [?', escaped, ?', " ++ ..."]
-          end
-        IO.iodata_to_binary inspected
-      keyword?(term) ->
-        surround_many(open, term, close, opts, &keyword/2, sep)
+      lists == :as_char_lists or (lists == :infer and printable?(thing)) ->
+        << ?', Inspect.BitString.escape(IO.chardata_to_string(thing), ?') :: binary, ?' >>
+      keyword?(thing) ->
+        surround_many("[", thing, "]", opts, &keyword/2)
       true ->
-        surround_many(open, term, close, opts, &to_doc/2, sep)
+        surround_many("[", thing, "]", opts, &to_doc/2)
     end
   end
 
-  @doc false
   def keyword({key, value}, opts) do
-    key = color(key_to_binary(key) <> ": ", :atom, opts)
-    concat(key, to_doc(value, opts))
+    concat(
+      key_to_binary(key) <> ": ",
+      to_doc(value, opts)
+    )
   end
 
-  @doc false
   def keyword?([{key, _value} | rest]) when is_atom(key) do
-    case Atom.to_charlist(key) do
+    case Atom.to_char_list(key) do
       'Elixir.' ++ _ -> false
       _ -> keyword?(rest)
     end
@@ -306,27 +301,6 @@ defimpl Inspect, for: List do
   def keyword?([]),     do: true
   def keyword?(_other), do: false
 
-  @doc false
-  def printable?(list), do: printable?(list, :infinity)
-
-  @doc false
-  def printable?(_, 0), do: true
-  def printable?([char | rest], counter) when char in 32..126, do: printable?(rest, decrement(counter))
-  def printable?([?\n | rest], counter), do: printable?(rest, decrement(counter))
-  def printable?([?\r | rest], counter), do: printable?(rest, decrement(counter))
-  def printable?([?\t | rest], counter), do: printable?(rest, decrement(counter))
-  def printable?([?\v | rest], counter), do: printable?(rest, decrement(counter))
-  def printable?([?\b | rest], counter), do: printable?(rest, decrement(counter))
-  def printable?([?\f | rest], counter), do: printable?(rest, decrement(counter))
-  def printable?([?\e | rest], counter), do: printable?(rest, decrement(counter))
-  def printable?([?\a | rest], counter), do: printable?(rest, decrement(counter))
-  def printable?([], _counter), do: true
-  def printable?(_, _counter), do: false
-
-  @compile {:inline, decrement: 1}
-  defp decrement(:infinity), do: :infinity
-  defp decrement(counter),   do: counter - 1
-
   ## Private
 
   defp key_to_binary(key) do
@@ -335,14 +309,25 @@ defimpl Inspect, for: List do
       other -> other
     end
   end
+
+  defp printable?([c|cs]) when is_integer(c) and c in 32..126, do: printable?(cs)
+  defp printable?([?\n|cs]), do: printable?(cs)
+  defp printable?([?\r|cs]), do: printable?(cs)
+  defp printable?([?\t|cs]), do: printable?(cs)
+  defp printable?([?\v|cs]), do: printable?(cs)
+  defp printable?([?\b|cs]), do: printable?(cs)
+  defp printable?([?\f|cs]), do: printable?(cs)
+  defp printable?([?\e|cs]), do: printable?(cs)
+  defp printable?([?\a|cs]), do: printable?(cs)
+  defp printable?([]), do: true
+  defp printable?(_), do: false
 end
 
 defimpl Inspect, for: Tuple do
+  def inspect({}, _opts), do: "{}"
+
   def inspect(tuple, opts) do
-    open = color("{", :tuple, opts)
-    sep = color(",", :tuple, opts)
-    close = color("}", :tuple, opts)
-    surround_many(open, Tuple.to_list(tuple), close, opts, &to_doc/2, sep)
+    surround_many("{", Tuple.to_list(tuple), "}", opts, &to_doc/2)
   end
 end
 
@@ -353,33 +338,29 @@ defimpl Inspect, for: Map do
 
   def inspect(map, name, opts) do
     map = :maps.to_list(map)
-    open = color("%" <> name <> "{", :map, opts)
-    sep = color(",", :map, opts)
-    close = color("}", :map, opts)
-    surround_many(open, map, close, opts, traverse_fun(map, opts), sep)
+    surround_many("%" <> name <> "{", map, "}", opts, traverse_fun(map))
   end
 
-  defp traverse_fun(list, opts) do
+  defp traverse_fun(list) do
     if Inspect.List.keyword?(list) do
       &Inspect.List.keyword/2
     else
-      sep = color(" => ", :map, opts)
-      &to_map(&1, &2, sep)
+      &to_map/2
     end
   end
 
-  defp to_map({key, value}, opts, sep) do
+  defp to_map({key, value}, opts) do
     concat(
-      concat(to_doc(key, opts), sep),
+      concat(to_doc(key, opts), " => "),
       to_doc(value, opts)
     )
   end
 end
 
 defimpl Inspect, for: Integer do
-  def inspect(term, %Inspect.Opts{base: base} = opts) do
-    inspected = Integer.to_string(term, base_to_value(base)) |> prepend_prefix(base)
-    color(inspected, :number, opts)
+  def inspect(thing, %Inspect.Opts{base: base}) do
+    Integer.to_string(thing, base_to_value(base))
+    |> prepend_prefix(base)
   end
 
   defp base_to_value(base) do
@@ -403,54 +384,60 @@ defimpl Inspect, for: Integer do
 end
 
 defimpl Inspect, for: Float do
-  def inspect(term, opts) do
-    inspected = IO.iodata_to_binary(:io_lib_format.fwrite_g(term))
-    color(inspected, :number, opts)
+  def inspect(thing, _opts) do
+    IO.iodata_to_binary(:io_lib_format.fwrite_g(thing))
   end
 end
 
 defimpl Inspect, for: Regex do
-  def inspect(regex, opts) do
-    source = IO.iodata_to_binary(['~r/', escape(regex.source, ?/), ?/, regex.opts])
-    color(source, :regex, opts)
+  def inspect(regex, _opts) do
+    delim = ?/
+    concat ["~r",
+            <<delim, escape(regex.source, delim)::binary, delim>>,
+            regex.opts]
   end
 
   defp escape(bin, term),
-    do: escape(bin, [], term)
+    do: escape(bin, <<>>, term)
 
-  defp escape(<<term, rest::binary>>, buf, term),
-    do: escape(rest, [buf | [?\\, term]], term)
+  defp escape(<<?\\, term>> <> rest, buf, term),
+    do: escape(rest, buf <> <<?\\, term>>, term)
 
-  # The list of characters is from 'String.printable?' implementation
+  defp escape(<<term>> <> rest, buf, term),
+    do: escape(rest, buf <> <<?\\, term>>, term)
+
+  # the list of characters is from `String.printable?` impl
   # minus characters treated specially by regex: \s, \d, \b, \e
 
-  defp escape(<<?\n, rest::binary>>, buf, term),
-    do: escape(rest, [buf | '\\n'], term)
+  defp escape(<<?\n>> <> rest, buf, term),
+    do: escape(rest, <<buf::binary, ?\\, ?n>>, term)
 
-  defp escape(<<?\r, rest::binary>>, buf, term),
-    do: escape(rest, [buf | '\\r'], term)
+  defp escape(<<?\r>> <> rest, buf, term),
+    do: escape(rest, <<buf::binary, ?\\, ?r>>, term)
 
-  defp escape(<<?\t, rest::binary>>, buf, term),
-    do: escape(rest, [buf | '\\t'], term)
+  defp escape(<<?\t>> <> rest, buf, term),
+    do: escape(rest, <<buf::binary, ?\\, ?t>>, term)
 
-  defp escape(<<?\v, rest::binary>>, buf, term),
-    do: escape(rest, [buf | '\\v'], term)
+  defp escape(<<?\v>> <> rest, buf, term),
+    do: escape(rest, <<buf::binary, ?\\, ?v>>, term)
 
-  defp escape(<<?\f, rest::binary>>, buf, term),
-    do: escape(rest, [buf | '\\f'], term)
+  defp escape(<<?\f>> <> rest, buf, term),
+    do: escape(rest, <<buf::binary, ?\\, ?f>>, term)
 
-  defp escape(<<?\a, rest::binary>>, buf, term),
-    do: escape(rest, [buf | '\\a'], term)
+  defp escape(<<?\a>> <> rest, buf, term),
+    do: escape(rest, <<buf::binary, ?\\, ?a>>, term)
 
-  defp escape(<<char::utf8, rest::binary>>, buf, term)
-       when char in 0x20..0x7E
-       when char in 0xA0..0xD7FF
-       when char in 0xE000..0xFFFD
-       when char in 0x10000..0x10FFFF,
-    do: escape(rest, [buf | <<char::utf8>>], term)
+  defp escape(<<c::utf8>> <> rest, buf, term) do
+    charstr = <<c::utf8>>
+    if String.printable?(charstr) and not c in [?\d, ?\b, ?\e] do
+      escape(rest, buf <> charstr, term)
+    else
+      escape(rest, buf <> Inspect.BitString.escape_char(c), term)
+    end
+  end
 
-  defp escape(<<char, rest::binary>>, buf, term),
-    do: escape(rest, [buf | Inspect.BitString.escape_char(char)], term)
+  defp escape(<<c>> <> rest, buf, term),
+    do: escape(rest, <<buf::binary, Inspect.BitString.escape_char(c)>>, term)
 
   defp escape(<<>>, buf, _), do: buf
 end
@@ -459,12 +446,11 @@ defimpl Inspect, for: Function do
   def inspect(function, _opts) do
     fun_info = :erlang.fun_info(function)
     mod = fun_info[:module]
-    name = fun_info[:name]
 
     if fun_info[:type] == :external and fun_info[:env] == [] do
-      "&#{Inspect.Atom.inspect(mod)}.#{escape_name(name)}/#{fun_info[:arity]}"
+      "&#{Inspect.Atom.inspect(mod)}.#{fun_info[:name]}/#{fun_info[:arity]}"
     else
-      case Atom.to_charlist(mod) do
+      case Atom.to_char_list(mod) do
         'elixir_compiler_' ++ _ ->
           if function_exported?(mod, :__RELATIVE__, 0) do
             "#Function<#{uniq(fun_info)} in file:#{mod.__RELATIVE__}>"
@@ -477,41 +463,6 @@ defimpl Inspect, for: Function do
     end
   end
 
-  def escape_name(atom) when is_atom(atom) do
-    string = Atom.to_string(atom)
-
-    case Macro.classify_identifier(atom) do
-      :callable ->
-        string
-      type when type in [:not_callable, :alias] ->
-        "\"" <> string <> "\""
-      :other ->
-        {escaped, _} = Inspect.BitString.escape(string, ?")
-        IO.iodata_to_binary [?", escaped, ?"]
-    end
-  end
-
-  # Example of this format: -NAME/ARITY-fun-COUNT-
-  def extract_anonymous_fun_parent(atom) when is_atom(atom) do
-    extract_anonymous_fun_parent(Atom.to_string(atom))
-  end
-
-  def extract_anonymous_fun_parent("-" <> rest) do
-    [trailing | reversed] =
-      rest
-      |> String.split("/")
-      |> Enum.reverse()
-
-    case String.split(trailing, "-") do
-      [arity, _inner, _count, ""] ->
-        {reversed |> Enum.reverse |> Enum.join("/") |> String.to_atom(), arity}
-      _other ->
-        :error
-    end
-  end
-
-  def extract_anonymous_fun_parent(other) when is_binary(other), do: :error
-
   defp default_inspect(mod, fun_info) do
     "#Function<#{uniq(fun_info)}/#{fun_info[:arity]} in " <>
       "#{Inspect.Atom.inspect(mod)}#{extract_name(fun_info[:name])}>"
@@ -522,11 +473,10 @@ defimpl Inspect, for: Function do
   end
 
   defp extract_name(name) do
-    case extract_anonymous_fun_parent(name) do
-      {name, arity} ->
-        "." <> escape_name(name) <> "/" <> arity
-      :error ->
-        "." <> escape_name(name)
+    name = Atom.to_string(name)
+    case :binary.split(name, "-", [:global]) do
+      ["", name | _] -> "." <> name
+      _ -> "." <> name
     end
   end
 
@@ -544,7 +494,7 @@ end
 
 defimpl Inspect, for: Port do
   def inspect(port, _opts) do
-    IO.iodata_to_binary(:erlang.port_to_list(port))
+    IO.iodata_to_binary :erlang.port_to_list(port)
   end
 end
 
@@ -565,8 +515,7 @@ defimpl Inspect, for: Any do
       dunder ->
         if :maps.keys(dunder) == :maps.keys(map) do
           pruned = :maps.remove(:__exception__, :maps.remove(:__struct__, map))
-          colorless_opts = %{opts | syntax_colors: []}
-          Inspect.Map.inspect(pruned, Inspect.Atom.inspect(struct, colorless_opts), opts)
+          Inspect.Map.inspect(pruned, Inspect.Atom.inspect(struct, opts), opts)
         else
           Inspect.Map.inspect(map, opts)
         end

lib/elixir/lib/inspect/algebra.ex

@@ -4,8 +4,8 @@ defmodule Inspect.Opts do
 
   The following fields are available:
 
-    * `:structs` - when `false`, structs are not formatted by the inspect
-      protocol, they are instead printed as maps, defaults to `true`.
+    * `:structs` - when false, structs are not formatted by the inspect
+      protocol, they are instead printed as maps, defaults to true.
 
     * `:binaries` - when `:as_strings` all binaries will be printed as strings,
       non-printable bytes will be escaped.
@@ -15,90 +15,53 @@ defmodule Inspect.Opts do
       When the default `:infer`, the binary will be printed as a string if it
       is printable, otherwise in bit syntax.
 
-    * `:charlists` - when `:as_charlists` all lists will be printed as char
+    * `:char_lists` - when `:as_char_lists` all lists will be printed as char
       lists, non-printable elements will be escaped.
 
       When `:as_lists` all lists will be printed as lists.
 
-      When the default `:infer`, the list will be printed as a charlist if it
+      When the default `:infer`, the list will be printed as a char list if it
       is printable, otherwise as list.
 
     * `:limit` - limits the number of items that are printed for tuples,
-      bitstrings, maps, lists and any other collection of items. It does not
-      apply to strings nor charlists and defaults to 50.
+      bitstrings, and lists, does not apply to strings nor char lists, defaults
+      to 50.
 
-    * `:printable_limit` - limits the number of bytes that are printed for strings
-      and char lists. Defaults to 4096.
+    * `:pretty` - if set to true enables pretty printing, defaults to false.
 
-    * `:pretty` - if set to `true` enables pretty printing, defaults to `false`.
+    * `:width` - defaults to the 80 characters, used when pretty is true or
+      when printing to IO devices.
 
-    * `:width` - defaults to 80 characters, used when pretty is `true` or when
-      printing to IO devices. Set to 0 to force each item to be printed on its
-      own line.
+    * `:base` - print integers as :binary, :octal, :decimal, or :hex, defaults
+      to :decimal
 
-    * `:base` - prints integers as `:binary`, `:octal`, `:decimal`, or `:hex`,
-      defaults to `:decimal`. When inspecting binaries any `:base` other than
-      `:decimal` implies `binaries: :as_binaries`.
-
-    * `:safe` - when `false`, failures while inspecting structs will be raised
-      as errors instead of being wrapped in the `Inspect.Error` exception. This
-      is useful when debugging failures and crashes for custom inspect
-      implementations
-
-    * `:syntax_colors` - when set to a keyword list of colors the output will
-      be colorized. The keys are types and the values are the colors to use for
-      each type. e.g. `[number: :red, atom: :blue]`. Types can include
-      `:number`, `:atom`, `regex`, `:tuple`, `:map`, `:list`, and `:reset`.
-      Colors can be any `t:IO.ANSI.ansidata/0` as accepted by `IO.ANSI.format/1`.
   """
 
-  # TODO: Remove :char_lists key by 2.0
   defstruct structs: true,
             binaries: :infer,
-            charlists: :infer,
             char_lists: :infer,
             limit: 50,
-            printable_limit: 4096,
             width: 80,
             base: :decimal,
-            pretty: false,
-            safe: true,
-            syntax_colors: []
+            pretty: false
 
-  @type color_key :: atom
-
-  # TODO: Remove :char_lists key and :as_char_lists value by 2.0
   @type t :: %__MODULE__{
                structs: boolean,
                binaries: :infer | :as_binaries | :as_strings,
-               charlists: :infer | :as_lists | :as_charlists,
                char_lists: :infer | :as_lists | :as_char_lists,
-               limit: pos_integer | :infinity,
-               printable_limit: pos_integer | :infinity,
+               limit: pos_integer,
                width: pos_integer | :infinity,
                base: :decimal | :binary | :hex | :octal,
-               pretty: boolean,
-               safe: boolean,
-               syntax_colors: [{color_key, IO.ANSI.ansidata}]
-             }
-end
-
-defmodule Inspect.Error do
-  @moduledoc """
-  Raised when a struct cannot be inspected.
-  """
-  defexception [:message]
+               pretty: boolean}
 end
 
 defmodule Inspect.Algebra do
   @moduledoc ~S"""
   A set of functions for creating and manipulating algebra
-  documents.
+  documents, as described in ["Strictly Pretty" (2000) by Christian Lindig][0].
 
-  This module implements the functionality described in
-  ["Strictly Pretty" (2000) by Christian Lindig][0] with small
-  additions, like support for String nodes, and a custom
-  rendering function that maximises horizontal space use.
+  An algebra document is represented by an `Inspect.Algebra` node
+  or a regular string.
 
       iex> Inspect.Algebra.empty
       :doc_nil
@@ -115,7 +78,7 @@ defmodule Inspect.Algebra do
 
   The functions `nest/2`, `space/2` and `line/2` help you put the
   document together into a rigid structure. However, the document
-  algebra gets interesting when using functions like `break/1`, which
+  algebra gets interesting when using functions like `break/2`, which
   converts the given string into a line break depending on how much space
   there is to print. Let's glue two docs together with a break and then
   render it:
@@ -141,7 +104,7 @@ defmodule Inspect.Algebra do
   `:flat` (breaks as spaces) and `:break` (breaks as newlines).
   Implementing the same logic in a strict language such as Elixir leads
   to an exponential growth of possible documents, unless document groups
-  are encoded explicitly as `:flat` or `:break`. Those groups are then reduced
+  are encoded explictly as `:flat` or `:break`. Those groups are then reduced
   to a simple document, where the layout is already decided, per [Lindig][0].
 
   This implementation slightly changes the semantic of Lindig's algorithm
@@ -164,11 +127,11 @@ defmodule Inspect.Algebra do
   @tail_separator " |"
   @newline "\n"
   @nesting 1
-  @space " "
+  @break " "
 
-  # Functional interface to "doc" records
+  # Functional interface to `doc` records
 
-  @type t :: :doc_nil | :doc_line | doc_cons | doc_nest | doc_break | doc_group | doc_color | binary
+  @type t :: :doc_nil | :doc_line | doc_cons | doc_nest | doc_break | doc_group | binary
 
   @typep doc_cons :: {:doc_cons, t, t}
   defmacrop doc_cons(left, right) do
@@ -177,7 +140,7 @@ defmodule Inspect.Algebra do
 
   @typep doc_nest :: {:doc_nest, t, non_neg_integer}
   defmacrop doc_nest(doc, indent) do
-    quote do: {:doc_nest, unquote(doc), unquote(indent)}
+    quote do: {:doc_nest, unquote(doc), unquote(indent) }
   end
 
   @typep doc_break :: {:doc_break, binary}
@@ -190,11 +153,6 @@ defmodule Inspect.Algebra do
     quote do: {:doc_group, unquote(group)}
   end
 
-  @typep doc_color :: {:doc_color, t, IO.ANSI.ansidata}
-  defmacrop doc_color(doc, color) do
-    quote do: {:doc_color, unquote(doc), unquote(color)}
-  end
-
   defmacrop is_doc(doc) do
     if Macro.Env.in_guard?(__CALLER__) do
       do_is_doc(doc)
@@ -212,25 +170,21 @@ defmodule Inspect.Algebra do
       is_binary(unquote(doc)) or
       unquote(doc) in [:doc_nil, :doc_line] or
       (is_tuple(unquote(doc)) and
-       elem(unquote(doc), 0) in [:doc_cons, :doc_nest, :doc_break, :doc_group, :doc_color])
+       elem(unquote(doc), 0) in [:doc_cons, :doc_nest, :doc_break, :doc_group])
     end
   end
 
   @doc """
-  Converts an Elixir term to an algebra document
-  according to the `Inspect` protocol.
+  Converts an Elixir structure to an algebra document
+  according to the inspect protocol.
   """
   @spec to_doc(any, Inspect.Opts.t) :: t
-  def to_doc(term, opts)
-
   def to_doc(%{__struct__: struct} = map, %Inspect.Opts{} = opts) when is_atom(struct) do
     if opts.structs do
       try do
         Inspect.inspect(map, opts)
       rescue
         e ->
-          stacktrace = System.stacktrace
-
           # Because we try to raise a nice error message in case
           # we can't inspect a struct, there is a chance the error
           # message itself relies on the struct being printed, so
@@ -242,20 +196,11 @@ defmodule Inspect.Algebra do
           else
             try do
               Process.put(:inspect_trap, true)
-
-              res = Inspect.Map.inspect(map, %{opts | syntax_colors: []})
-              res = IO.iodata_to_binary(format(res, :infinity))
-
-              exception = Inspect.Error.exception(
-                message: "got #{inspect e.__struct__} with message " <>
-                         "#{inspect Exception.message(e)} while inspecting #{res}"
-              )
-
-              if opts.safe do
-                Inspect.inspect(exception, opts)
-              else
-                reraise(exception, stacktrace)
-              end
+              res = Inspect.Map.inspect(map, opts)
+              formatted = IO.iodata_to_binary(format(res, :infinity))
+              raise ArgumentError,
+                "Got #{inspect e.__struct__} with message " <>
+                "\"#{Exception.message(e)}\" while inspecting #{formatted}"
             after
               Process.delete(:inspect_trap)
             end
@@ -282,51 +227,31 @@ defmodule Inspect.Algebra do
   @spec empty() :: :doc_nil
   def empty, do: :doc_nil
 
-  @doc ~S"""
-  Concatenates two document entities returning a new document.
+  @doc """
+  Concatenates two document entities.
 
   ## Examples
 
-      iex> doc = Inspect.Algebra.concat("hello", "world")
+      iex> doc = Inspect.Algebra.concat "hello", "world"
       iex> Inspect.Algebra.format(doc, 80)
       ["hello", "world"]
 
   """
-  @spec concat(t, t) :: t
-  def concat(doc1, doc2) when is_doc(doc1) and is_doc(doc2) do
-    doc_cons(doc1, doc2)
+  @spec concat(t, t) :: doc_cons
+  def concat(x, y) when is_doc(x) and is_doc(y) do
+    doc_cons(x, y)
   end
 
-  @doc ~S"""
-  Concatenates a list of documents returning a new document.
-
-  ## Examples
-
-      iex> doc = Inspect.Algebra.concat(["a", "b", "c"])
-      iex> Inspect.Algebra.format(doc, 80)
-      ["a", "b", "c"]
-
+  @doc """
+  Concatenates a list of documents.
   """
-  @spec concat([t]) :: t
-  def concat(docs) when is_list(docs) do
-    fold_doc(docs, &concat(&1, &2))
+  @spec concat([t]) :: doc_cons
+  def concat(docs) do
+    folddoc(docs, &concat(&1, &2))
   end
 
   @doc ~S"""
-  Colors a document if the `color_key` has a color in the options.
-  """
-  @spec color(t, Inspect.Opts.color_key, Inspect.Opts.t) :: doc_color
-  def color(doc, color_key, %Inspect.Opts{syntax_colors: syntax_colors}) when is_doc(doc) do
-    if precolor = Keyword.get(syntax_colors, color_key) do
-      postcolor = Keyword.get(syntax_colors, :reset, :reset)
-      concat(doc_color(doc, precolor), doc_color(empty(), postcolor))
-    else
-      doc
-    end
-  end
-
-  @doc ~S"""
-  Nests the given document at the given `level`.
+  Nests document entity `x` positions deep.
 
   Nesting will be appended to the line breaks.
 
@@ -338,91 +263,58 @@ defmodule Inspect.Algebra do
 
   """
   @spec nest(t, non_neg_integer) :: doc_nest
-  def nest(doc, level)
-
-  def nest(doc, 0) when is_doc(doc) do
-    doc
+  def nest(x, 0) when is_doc(x) do
+    x
   end
 
-  def nest(doc, level) when is_doc(doc) and is_integer(level) and level > 0 do
-    doc_nest(doc, level)
+  def nest(x, i) when is_doc(x) and is_integer(i) do
+    doc_nest(x, i)
   end
 
   @doc ~S"""
-  Returns a document entity representing a break based on the given
-  `string`.
+  Document entity representing a break.
 
-  This break can be rendered as a linebreak or as the given `string`,
+  This break can be rendered as a linebreak or as spaces,
   depending on the `mode` of the chosen layout or the provided
   separator.
 
   ## Examples
 
-  Let's create a document by concatenating two strings with a break between
-  them:
+  Let's glue two docs together with a break and then render it:
 
-      iex> doc = Inspect.Algebra.concat(["a", Inspect.Algebra.break("\t"), "b"])
+      iex> doc = Inspect.Algebra.glue("a", " ", "b")
       iex> Inspect.Algebra.format(doc, 80)
-      ["a", "\t", "b"]
+      ["a", " ", "b"]
 
-  Notice the break was represented with the given string, because we didn't
-  reach a line limit. Once we do, it is replaced by a newline:
+  Notice the break was represented as is, because we haven't reached
+  a line limit. Once we do, it is replaced by a newline:
 
-      iex> break = Inspect.Algebra.break("\t")
-      iex> doc = Inspect.Algebra.concat([String.duplicate("a", 20), break, "b"])
+      iex> doc = Inspect.Algebra.glue(String.duplicate("a", 20), " ", "b")
       iex> Inspect.Algebra.format(doc, 10)
       ["aaaaaaaaaaaaaaaaaaaa", "\n", "b"]
 
   """
   @spec break(binary) :: doc_break
-  def break(string) when is_binary(string), do: doc_break(string)
+  def break(s) when is_binary(s), do: doc_break(s)
 
-  @doc ~S"""
-  Returns a document entity with the `" "` string as break.
-
-  See `break/1` for more information.
-  """
   @spec break() :: doc_break
-  def break(), do: doc_break(@space)
-
-  @doc ~S"""
-  Glues two documents together inserting `" "` as a break between them.
-
-  This means the two documents will be separated by `" "` in case they
-  fit in the same line. Otherwise a line break is used.
-
-  ## Examples
-
-      iex> doc = Inspect.Algebra.glue("hello", "world")
-      iex> Inspect.Algebra.format(doc, 80)
-      ["hello", " ", "world"]
+  def break(), do: doc_break(@break)
 
+  @doc """
+  Inserts a break between two docs. See `break/1` for more info.
   """
-  @spec glue(t, t) :: t
-  def glue(doc1, doc2), do: concat(doc1, concat(break(), doc2))
-
-  @doc ~S"""
-  Glues two documents (`doc1` and `doc2`) together inserting the given
-  break `break_string` between them.
-
-  For more information on how the break is inserted, see `break/1`.
-
-  ## Examples
-
-      iex> doc = Inspect.Algebra.glue("hello", "\t", "world")
-      iex> Inspect.Algebra.format(doc, 80)
-      ["hello", "\t", "world"]
+  @spec glue(t, t) :: doc_cons
+  def glue(x, y), do: concat(x, concat(break, y))
 
+  @doc """
+  Inserts a break, passed as the second argument, between two docs,
+  the first and the third arguments.
   """
-  @spec glue(t, binary, t) :: t
-  def glue(doc1, break_string, doc2) when is_binary(break_string),
-    do: concat(doc1, concat(break(break_string), doc2))
+  @spec glue(t, binary, t) :: doc_cons
+  def glue(x, g, y) when is_binary(g), do: concat(x, concat(break(g), y))
 
   @doc ~S"""
-  Returns a group containing the specified document `doc`.
-
-  Documents in a group are attempted to be rendered together
-  to the best of the renderer ability.
+  Returns a group containing the specified document.
 
   ## Examples
 
@@ -449,91 +341,82 @@ defmodule Inspect.Algebra do
 
   """
   @spec group(t) :: doc_group
-  def group(doc) when is_doc(doc) do
-    doc_group(doc)
+  def group(d) when is_doc(d) do
+    doc_group(d)
   end
 
-  @doc ~S"""
-  Inserts a mandatory single space between two documents.
+  @doc """
+  Inserts a mandatory single space between two document entities.
 
   ## Examples
 
-      iex> doc = Inspect.Algebra.space("Hughes", "Wadler")
-      iex> Inspect.Algebra.format(doc, 5)
+      iex> doc = Inspect.Algebra.space "Hughes", "Wadler"
+      iex> Inspect.Algebra.format(doc, 80)
       ["Hughes", " ", "Wadler"]
 
   """
-  @spec space(t, t) :: t
-  def space(doc1, doc2), do: concat(doc1, concat(" ", doc2))
+  @spec space(t, t) :: doc_cons
+  def space(x, y), do: concat(x, concat(" ", y))
 
   @doc ~S"""
-  Inserts a mandatory linebreak between two documents.
+  Inserts a mandatory linebreak between two document entities.
 
   ## Examples
 
-      iex> doc = Inspect.Algebra.line("Hughes", "Wadler")
+      iex> doc = Inspect.Algebra.line "Hughes", "Wadler"
       iex> Inspect.Algebra.format(doc, 80)
       ["Hughes", "\n", "Wadler"]
 
   """
-  @spec line(t, t) :: t
-  def line(doc1, doc2), do: concat(doc1, concat(:doc_line, doc2))
+  @spec line(t, t) :: doc_cons
+  def line(x, y), do: concat(x, concat(:doc_line, y))
 
-  @doc ~S"""
-  Folds a list of documents into a document using the given folder function.
-
-  The list of documents is folded "from the right"; in that, this function is
-  similar to `List.foldr/3`, except that it doesn't expect an initial
-  accumulator and uses the last element of `docs` as the initial accumulator.
+  @doc """
+  Folds a list of document entities into a document entity
+  using a function that is passed as the first argument.
 
   ## Examples
 
-      iex> docs = ["A", "B", "C"]
-      iex> docs = Inspect.Algebra.fold_doc(docs, fn(doc, acc) ->
-      ...>   Inspect.Algebra.concat([doc, "!", acc])
+      iex> doc = ["A", "B"]
+      iex> doc = Inspect.Algebra.folddoc(doc, fn(x,y) ->
+      ...>   Inspect.Algebra.concat [x, "!", y]
       ...> end)
-      iex> Inspect.Algebra.format(docs, 80)
-      ["A", "!", "B", "!", "C"]
+      iex> Inspect.Algebra.format(doc, 80)
+      ["A", "!", "B"]
 
   """
-  @spec fold_doc([t], ((t, t) -> t)) :: t
-  def fold_doc(docs, folder_fun)
-
-  def fold_doc([], _folder_fun),
-    do: empty()
-  def fold_doc([doc], _folder_fun),
-    do: doc
-  def fold_doc([doc | docs], folder_fun) when is_function(folder_fun, 2),
-    do: folder_fun.(doc, fold_doc(docs, folder_fun))
+  @spec folddoc([t], ((t, t) -> t)) :: t
+  def folddoc([], _), do: empty
+  def folddoc([doc], _), do: doc
+  def folddoc([d|ds], f), do: f.(d, folddoc(ds, f))
 
   # Elixir conveniences
 
   @doc ~S"""
   Surrounds a document with characters.
 
-  Puts the given document `doc` between the `left` and `right` documents enclosing
-  and nesting it. The document is marked as a group, to show the maximum as
-  possible concisely together.
+  Puts the document between left and right enclosing and nesting it.
+  The document is marked as a group, to show the maximum as possible
+  concisely together.
 
   ## Examples
 
-      iex> doc = Inspect.Algebra.surround("[", Inspect.Algebra.glue("a", "b"), "]")
+      iex> doc = Inspect.Algebra.surround "[", Inspect.Algebra.glue("a", "b"), "]"
       iex> Inspect.Algebra.format(doc, 3)
       ["[", "a", "\n ", "b", "]"]
 
   """
-  @spec surround(t, t, t) :: t
-  def surround(left, doc, right) when is_doc(left) and is_doc(doc) and is_doc(right) do
-    group(concat(left, concat(nest(doc, @nesting), right)))
+  @spec surround(binary, t, binary) :: t
+  def surround(left, doc, right) do
+    group concat left, concat(nest(doc, @nesting), right)
   end
 
   @doc ~S"""
   Maps and glues a collection of items.
 
-  It uses the given `left` and `right` documents as surrounding and the
-  separator document `separator` to separate items in `docs`. A limit can be
-  passed: when this limit is reached, this function stops gluing and outputs
-  `"..."` instead.
+  It uses the given left and right as surrounding and a separator for
+  each item. A limit can be passed which, once reached, stops gluing
+  and outputs "..." instead.
 
   ## Examples
 
@@ -551,11 +434,9 @@ defmodule Inspect.Algebra do
       ...>         %Inspect.Opts{limit: 3}, fn i, _opts -> to_string(i) end, "!")
       iex> Inspect.Algebra.format(doc, 20) |> IO.iodata_to_binary
       "[1! 2! 3! ...]"
-
   """
-  @spec surround_many(t, [any], t, Inspect.Opts.t, (term, Inspect.Opts.t -> t), t) :: t
-  def surround_many(left, docs, right, %Inspect.Opts{} = opts, fun, separator \\ @surround_separator)
-      when is_doc(left) and is_list(docs) and is_doc(right) and is_function(fun, 2) and is_doc(separator) do
+  @spec surround_many(binary, [any], binary, Inspect.Opts.t, (term, Inspect.Opts.t -> t), binary) :: t
+  def surround_many(left, docs, right, opts, fun, separator \\ @surround_separator) do
     do_surround_many(left, docs, right, opts.limit, opts, fun, separator)
   end
 
@@ -563,63 +444,47 @@ defmodule Inspect.Algebra do
     concat(left, right)
   end
 
-  defp do_surround_many(left, docs, right, limit, opts, fun, sep) do
-    surround(left, do_surround_many(docs, limit, opts, fun, sep), right)
+  defp do_surround_many(left, docs, right, limit, _opts, fun, sep) do
+    surround(left, do_surround_many(docs, limit, _opts, fun, sep), right)
   end
 
   defp do_surround_many(_, 0, _opts, _fun, _sep) do
     "..."
   end
 
-  defp do_surround_many([], _limit, _opts, _fun, _sep) do
-    :doc_nil
-  end
-
   defp do_surround_many([h], limit, opts, fun, _sep) do
     fun.(h, %{opts | limit: limit})
   end
 
-  defp do_surround_many([h | t], limit, opts, fun, sep) when is_list(t) do
+  defp do_surround_many([h|t], limit, opts, fun, sep) when is_list(t) do
     limit = decrement(limit)
-    h = fun.(h, %{opts | limit: limit})
-    t = do_surround_many(t, limit, opts, fun, sep)
-    do_join(h, t, sep)
+    glue(
+      concat(fun.(h, %{opts | limit: limit}), sep),
+      do_surround_many(t, limit, opts, fun, sep)
+    )
   end
 
-  defp do_surround_many([h | t], limit, opts, fun, _sep) do
+  defp do_surround_many([h|t], limit, opts, fun, _sep) do
     limit = decrement(limit)
-    h = fun.(h, %{opts | limit: limit})
-    t = fun.(t, %{opts | limit: limit})
-    do_join(h, t, @tail_separator)
+    glue(
+      concat(fun.(h, %{opts | limit: limit}), @tail_separator),
+      fun.(t, %{opts | limit: limit})
+    )
   end
 
-  defp do_join(:doc_nil, :doc_nil, _), do: :doc_nil
-  defp do_join(h, :doc_nil, _),        do: h
-  defp do_join(:doc_nil, t, _),        do: t
-  defp do_join(h, t, sep),             do: glue(concat(h, sep), t)
-
   defp decrement(:infinity), do: :infinity
   defp decrement(counter),   do: counter - 1
 
-  @doc ~S"""
-  Formats a given document for a given width.
+  @doc """
+  The formatting function.
 
   Takes the maximum width and a document to print as its arguments
   and returns an IO data representation of the best layout for the
   document to fit in the given width.
-
-  ## Examples
-
-      iex> doc = Inspect.Algebra.glue("hello", " ", "world")
-      iex> Inspect.Algebra.format(doc, 30) |> IO.iodata_to_binary()
-      "hello world"
-      iex> Inspect.Algebra.format(doc, 10) |> IO.iodata_to_binary()
-      "hello\nworld"
-
   """
   @spec format(t, non_neg_integer | :infinity) :: iodata
-  def format(doc, width) when is_doc(doc) and (width == :infinity or width >= 0) do
-    format(width, 0, [{0, default_mode(width), doc_group(doc)}])
+  def format(d, w) do
+    format(w, 0, [{0, default_mode(w), doc_group(d)}])
   end
 
   defp default_mode(:infinity), do: :flat
@@ -634,11 +499,10 @@ defmodule Inspect.Algebra do
   defp fits?(_, [{_, _, :doc_line} | _]),           do: true
   defp fits?(w, [{_, _, :doc_nil} | t]),            do: fits?(w, t)
   defp fits?(w, [{i, m, doc_cons(x, y)} | t]),      do: fits?(w, [{i, m, x} | [{i, m, y} | t]])
-  defp fits?(w, [{i, m, doc_color(x, _)} | t]),    do: fits?(w, [{i, m, x} | t])
   defp fits?(w, [{i, m, doc_nest(x, j)} | t]),      do: fits?(w, [{i + j, m, x} | t])
   defp fits?(w, [{i, _, doc_group(x)} | t]),        do: fits?(w, [{i, :flat, x} | t])
-  defp fits?(w, [{_, _, s} | t]) when is_binary(s), do: fits?((w - byte_size(s)), t)
-  defp fits?(w, [{_, :flat, doc_break(s)} | t]),    do: fits?((w - byte_size(s)), t)
+  defp fits?(w, [{_, _, s} | t]) when is_binary(s), do: fits?((w - byte_size s), t)
+  defp fits?(w, [{_, :flat, doc_break(s)} | t]),    do: fits?((w - byte_size s), t)
   defp fits?(_, [{_, :break, doc_break(_)} | _]),   do: true
 
   @spec format(integer | :infinity, integer, [{integer, mode, t}]) :: [binary]
@@ -648,9 +512,8 @@ defmodule Inspect.Algebra do
   defp format(w, k, [{i, m, doc_cons(x, y)} | t]),      do: format(w, k, [{i, m, x} | [{i, m, y} | t]])
   defp format(w, k, [{i, m, doc_nest(x, j)} | t]),      do: format(w, k, [{i + j, m, x} | t])
   defp format(w, k, [{i, m, doc_group(x)} | t]),        do: format(w, k, [{i, m, x} | t])
-  defp format(w, k, [{i, m, doc_color(x, c)} | t]),     do: [ansi(c) | format(w, k, [{i, m, x} | t])]
-  defp format(w, k, [{_, _, s} | t]) when is_binary(s), do: [s | format(w, (k + byte_size(s)), t)]
-  defp format(w, k, [{_, :flat, doc_break(s)} | t]),    do: [s | format(w, (k + byte_size(s)), t)]
+  defp format(w, k, [{_, _, s} | t]) when is_binary(s), do: [s | format(w, (k + byte_size s), t)]
+  defp format(w, k, [{_, :flat, doc_break(s)} | t]),    do: [s | format(w, (k + byte_size s), t)]
   defp format(w, k, [{i, :break, doc_break(s)} | t]) do
     k = k + byte_size(s)
 
@@ -661,10 +524,6 @@ defmodule Inspect.Algebra do
     end
   end
 
-  defp ansi(color) do
-    IO.ANSI.format_fragment(color, true)
-  end
-
   defp indent(0), do: @newline
   defp indent(i), do: @newline <> :binary.copy(" ", i)
 end

lib/elixir/lib/integer.ex

@@ -6,276 +6,75 @@ defmodule Integer do
   import Bitwise
 
   @doc """
-  Determines if `integer` is odd.
+  Determines if an integer is odd.
 
-  Returns `true` if the given `integer` is an odd number,
-  otherwise it returns `false`.
+  Returns `true` if `n` is an odd number, otherwise `false`.
 
   Allowed in guard clauses.
-
-  ## Examples
-
-      iex> Integer.is_odd(5)
-      true
-
-      iex> Integer.is_odd(6)
-      false
-
-      iex> Integer.is_odd(-5)
-      true
-
-      iex> Integer.is_odd(0)
-      false
-
   """
-  defmacro is_odd(integer) do
-    quote do: (unquote(integer) &&& 1) == 1
+  defmacro is_odd(n) do
+    quote do: (unquote(n) &&& 1) == 1
   end
 
   @doc """
-  Determines if an `integer` is even.
+  Determines if an integer is even.
 
-  Returns `true` if the given `integer` is an even number,
-  otherwise it returns `false`.
+  Returns `true` if `n` is an even number, otherwise `false`.
 
   Allowed in guard clauses.
-
-  ## Examples
-
-      iex> Integer.is_even(10)
-      true
-
-      iex> Integer.is_even(5)
-      false
-
-      iex> Integer.is_even(-10)
-      true
-
-      iex> Integer.is_even(0)
-      true
-
   """
-  defmacro is_even(integer) do
-    quote do: (unquote(integer) &&& 1) == 0
+  defmacro is_even(n) do
+    quote do: (unquote(n) &&& 1) == 0
   end
 
   @doc """
-  Computes the modulo remainder of an integer division.
+  Converts a binary to an integer.
 
-  `Integer.mod/2` uses floored division, which means that
-  the result will always have the sign of the `divisor`.
-
-  Raises an `ArithmeticError` exception if one of the arguments is not an
-  integer, or when the `divisor` is `0`.
-
-  ## Examples
-
-      iex> Integer.mod(5, 2)
-      1
-      iex> Integer.mod(6, -4)
-      -2
-
-  """
-  @spec mod(integer, neg_integer | pos_integer) :: integer
-  def mod(dividend, divisor) do
-    remainder = rem(dividend, divisor)
-    if remainder * divisor < 0 do
-      remainder + divisor
-    else
-      remainder
-    end
-  end
-
-  @doc """
-  Performs a floored integer division.
-
-  Raises an `ArithmeticError` exception if one of the arguments is not an
-  integer, or when the `divisor` is `0`.
-
-  `Integer.floor_div/2` performs *floored* integer division. This means that
-  the result is always rounded towards negative infinity.
-
-  If you want to perform truncated integer division (rounding towards zero),
-  use `Kernel.div/2` instead.
-
-  ## Examples
-
-      iex> Integer.floor_div(5, 2)
-      2
-      iex> Integer.floor_div(6, -4)
-      -2
-      iex> Integer.floor_div(-99, 2)
-      -50
-
-  """
-  @spec floor_div(integer, neg_integer | pos_integer) :: integer
-  def floor_div(dividend, divisor) do
-    if (dividend * divisor < 0) and rem(dividend, divisor) != 0 do
-      div(dividend, divisor) - 1
-    else
-      div(dividend, divisor)
-    end
-  end
-
-  @doc """
-  Returns the ordered digits for the given `integer`.
-
-  An optional `base` value may be provided representing the radix for the returned
-  digits. This one must be an integer >= 2.
-
-  ## Examples
-
-      iex> Integer.digits(123)
-      [1, 2, 3]
-
-      iex> Integer.digits(170, 2)
-      [1, 0, 1, 0, 1, 0, 1, 0]
-
-      iex> Integer.digits(-170, 2)
-      [-1, 0, -1, 0, -1, 0, -1, 0]
-
-  """
-  @spec digits(integer, pos_integer) :: [integer, ...]
-  def digits(integer, base \\ 10)
-      when is_integer(integer) and is_integer(base) and base >= 2 do
-    do_digits(integer, base, [])
-  end
-
-  defp do_digits(digit, base, []) when abs(digit) < base,
-    do: [digit]
-  defp do_digits(digit, base, []) when digit == -base,
-    do: [-1, 0]
-  defp do_digits(base, base, []),
-    do: [1, 0]
-  defp do_digits(0, _base, acc),
-    do: acc
-  defp do_digits(integer, base, acc),
-    do: do_digits(div(integer, base), base, [rem(integer, base) | acc])
-
-  @doc """
-  Returns the integer represented by the ordered `digits`.
-
-  An optional `base` value may be provided representing the radix for the `digits`.
-  This one can be an integer >= 2.
-
-  ## Examples
-
-      iex> Integer.undigits([1, 2, 3])
-      123
-
-      iex> Integer.undigits([1, 4], 16)
-      20
-
-      iex> Integer.undigits([])
-      0
-
-  """
-  @spec undigits([integer], integer) :: integer
-  def undigits(digits, base \\ 10) when is_list(digits) and is_integer(base) and base >= 2 do
-    do_undigits(digits, base, 0)
-  end
-
-  defp do_undigits([], _base, 0),
-    do: 0
-  defp do_undigits([digit], base, 0) when is_integer(digit) and digit < base,
-    do: digit
-  defp do_undigits([1, 0], base, 0),
-    do: base
-  defp do_undigits([0 | tail], base, 0),
-    do: do_undigits(tail, base, 0)
-
-  defp do_undigits([], _base, acc),
-    do: acc
-  defp do_undigits([digit | _], base, _) when is_integer(digit) and digit >= base,
-    do: raise ArgumentError, "invalid digit #{digit} in base #{base}"
-  defp do_undigits([digit | tail], base, acc) when is_integer(digit),
-    do: do_undigits(tail, base, acc * base + digit)
-
-  @doc """
-  Parses a text representation of an integer.
-
-  An optional `base` to the corresponding integer can be provided.
-  If `base` is not given, 10 will be used.
-
-  If successful, returns a tuple in the form of `{integer, remainder_of_binary}`.
+  If successful, returns a tuple of the form `{integer, remainder_of_binary}`.
   Otherwise `:error`.
 
-  Raises an error if `base` is less than 2 or more than 36.
-
-  If you want to convert a string-formatted integer directly to a integer,
-  `String.to_integer/1` or `String.to_integer/2` can be used instead.
-
   ## Examples
 
       iex> Integer.parse("34")
-      {34, ""}
+      {34,""}
 
       iex> Integer.parse("34.5")
-      {34, ".5"}
+      {34,".5"}
 
       iex> Integer.parse("three")
       :error
 
-      iex> Integer.parse("34", 10)
-      {34, ""}
-
-      iex> Integer.parse("f4", 16)
-      {244, ""}
-
-      iex> Integer.parse("Awww++", 36)
-      {509216, "++"}
-
-      iex> Integer.parse("fab", 10)
-      :error
-
-      iex> Integer.parse("a2", 38)
-      ** (ArgumentError) invalid base 38
-
   """
-  @spec parse(binary, 2..36) :: {integer, binary} | :error
-  def parse(binary, base \\ 10)
-
-  def parse(_binary, base) when not base in 2..36 do
-    raise ArgumentError, "invalid base #{inspect base}"
-  end
-
-  def parse(binary, base) do
-    case count_digits(binary, base) do
-      0 ->
-        :error
-      count ->
-        {digits, rem} = :erlang.split_binary(binary, count)
-        {:erlang.binary_to_integer(digits, base), rem}
+  @spec parse(binary) :: {integer, binary} | :error
+  def parse(<< ?-, bin :: binary >>) do
+    case do_parse(bin) do
+      :error -> :error
+      {number, remainder} -> {-number, remainder}
     end
   end
 
-  defp count_digits(<<sign, rest::binary>>, base) when sign in '+-' do
-    case count_digits_nosign(rest, base, 1) do
-      1 -> 0
-      count -> count
-    end
+  def parse(<< ?+, bin :: binary >>) do
+    do_parse(bin)
   end
 
-  defp count_digits(<<rest::binary>>, base) do
-    count_digits_nosign(rest, base, 0)
+  def parse(bin) when is_binary(bin) do
+    do_parse(bin)
   end
 
-  digits = [{?0..?9, -?0}, {?A..?Z, 10 - ?A}, {?a..?z, 10 - ?a}]
+  defp do_parse(<< char, bin :: binary >>) when char in ?0..?9, do: do_parse(bin, char - ?0)
+  defp do_parse(_), do: :error
 
-  for {chars, diff} <- digits, char <- chars do
-    digit = char + diff
-
-    defp count_digits_nosign(<<unquote(char), rest::binary>>, base, count)
-        when base > unquote(digit) do
-      count_digits_nosign(rest, base, count + 1)
-    end
+  defp do_parse(<< char, rest :: binary >>, acc) when char in ?0..?9 do
+    do_parse rest, 10 * acc + (char - ?0)
   end
 
-  defp count_digits_nosign(<<_::binary>>, _, count), do: count
+  defp do_parse(bitstring, acc) do
+    {acc, bitstring}
+  end
 
   @doc """
   Returns a binary which corresponds to the text representation
-  of `integer`.
+  of `some_integer`.
 
   Inlined by the compiler.
 
@@ -284,26 +83,15 @@ defmodule Integer do
       iex> Integer.to_string(123)
       "123"
 
-      iex> Integer.to_string(+456)
-      "456"
-
-      iex> Integer.to_string(-789)
-      "-789"
-
-      iex> Integer.to_string(0123)
-      "123"
-
   """
   @spec to_string(integer) :: String.t
-  def to_string(integer) do
-    :erlang.integer_to_binary(integer)
+  def to_string(some_integer) do
+    :erlang.integer_to_binary(some_integer)
   end
 
   @doc """
   Returns a binary which corresponds to the text representation
-  of `integer` in the given `base`.
-
-  `base` can be an integer between 2 and 36.
+  of `some_integer` in base `base`.
 
   Inlined by the compiler.
 
@@ -312,115 +100,42 @@ defmodule Integer do
       iex> Integer.to_string(100, 16)
       "64"
 
-      iex> Integer.to_string(-100, 16)
-      "-64"
-
-      iex> Integer.to_string(882681651, 36)
-      "ELIXIR"
-
   """
   @spec to_string(integer, 2..36) :: String.t
-  def to_string(integer, base) do
-    :erlang.integer_to_binary(integer, base)
+  def to_string(some_integer, base) do
+    :erlang.integer_to_binary(some_integer, base)
   end
 
   @doc """
-  Returns a charlist which corresponds to the text representation of the given `integer`.
+  Returns a char list which corresponds to the text representation of the given integer.
 
   Inlined by the compiler.
 
   ## Examples
 
-      iex> Integer.to_charlist(123)
-      '123'
-
-      iex> Integer.to_charlist(+456)
-      '456'
-
-      iex> Integer.to_charlist(-789)
-      '-789'
-
-      iex> Integer.to_charlist(0123)
-      '123'
+      iex> Integer.to_char_list(7)
+      '7'
 
   """
-  @spec to_charlist(integer) :: charlist
-  def to_charlist(integer) do
-    :erlang.integer_to_list(integer)
+  @spec to_char_list(integer) :: char_list
+  def to_char_list(number) do
+    :erlang.integer_to_list(number)
   end
 
   @doc """
-  Returns a charlist which corresponds to the text representation of `integer` in the given `base`.
-
-  `base` can be an integer between 2 and 36.
+  Returns a char list which corresponds to the text representation of the
+  given integer in the given case.
 
   Inlined by the compiler.
 
   ## Examples
 
-      iex> Integer.to_charlist(100, 16)
-      '64'
-
-      iex> Integer.to_charlist(-100, 16)
-      '-64'
-
-      iex> Integer.to_charlist(882681651, 36)
-      'ELIXIR'
+      iex> Integer.to_char_list(1023, 16)
+      '3FF'
 
   """
-  @spec to_charlist(integer, 2..36) :: charlist
-  def to_charlist(integer, base) do
-    :erlang.integer_to_list(integer, base)
+  @spec to_char_list(integer, 2..36) :: char_list
+  def to_char_list(number, base) do
+    :erlang.integer_to_list(number, base)
   end
-
-  @doc """
-  Returns the greatest common divisor of the two given integers.
-
-  The greatest common divisor (GCD) of `integer1` and `integer2` is the largest positive
-  integer that divides both `integer1` and `integer2` without leaving a remainder.
-
-  By convention, `gcd(0, 0)` returns `0`.
-
-  ## Examples
-
-      iex> Integer.gcd(2, 3)
-      1
-
-      iex> Integer.gcd(8, 12)
-      4
-
-      iex> Integer.gcd(8, -12)
-      4
-
-      iex> Integer.gcd(10, 0)
-      10
-
-      iex> Integer.gcd(7, 7)
-      7
-
-      iex> Integer.gcd(0, 0)
-      0
-
-  """
-  @spec gcd(0, 0) :: 0
-  @spec gcd(integer, integer) :: pos_integer
-  def gcd(integer1, integer2) when is_integer(integer1) and is_integer(integer2) do
-    gcd_positive(abs(integer1), abs(integer2))
-  end
-
-  defp gcd_positive(0, integer2), do: integer2
-  defp gcd_positive(integer1, 0), do: integer1
-  defp gcd_positive(integer1, integer2), do: gcd_positive(integer2, rem(integer1, integer2))
-
-  # TODO: Remove by 2.0
-  # (hard-deprecated in elixir_dispatch)
-  @doc false
-  @spec to_char_list(integer) :: charlist
-  def to_char_list(integer), do: Integer.to_charlist(integer)
-
-  # TODO: Remove by 2.0
-  # (hard-deprecated in elixir_dispatch)
-  @doc false
-  @spec to_char_list(integer, 2..36) :: charlist
-  def to_char_list(integer, base), do: Integer.to_charlist(integer, base)
 end

lib/elixir/lib/io.ex

@@ -1,36 +1,32 @@
 defmodule IO do
   @moduledoc """
-  Functions handling input/output (IO).
+  Functions handling IO.
 
-  Many functions in this module expect an IO device as an argument.
-  An IO device must be a PID or an atom representing a process.
+  Many functions in this module expects an IO device as argument.
+  An IO device must be a pid or an atom representing a process.
   For convenience, Elixir provides `:stdio` and `:stderr` as
   shortcuts to Erlang's `:standard_io` and `:standard_error`.
 
-  The majority of the functions expect chardata, i.e. strings or
+  The majority of the functions expect char data, i.e. strings or
   lists of characters and strings. In case another type is given,
-  functions will convert to string via the `String.Chars` protocol
+  it will do a conversion to string via the `String.Chars` protocol
   (as shown in typespecs).
 
-  The functions starting with `bin` expect iodata as an argument,
+  The functions starting with `bin*` expects iodata as argument,
   i.e. binaries or lists of bytes and binaries.
 
   ## IO devices
 
-  An IO device may be an atom or a PID. In case it is an atom,
-  the atom must be the name of a registered process. In addition,
-  Elixir provides two shortcuts:
+  An IO device may be an atom or a pid. In case it is an atom,
+  the atom must be the name of a registered process. However,
+  there are three exceptions for this rule:
 
-    * `:stdio` - a shortcut for `:standard_io`, which maps to
-      the current `Process.group_leader/0` in Erlang
+    * `:standard_io` - when the `:standard_io` atom is given,
+      it is treated as a shortcut for `Process.group_leader`
 
-    * `:stderr` - a shortcut for the named process `:standard_error`
-      provided in Erlang
+    * `:stdio` - is a shortcut for `:standard_io`
 
-  IO devices maintain their position, that means subsequent calls to any
-  reading or writing functions will start from the place when the device
-  was last accessed. Position of files can be changed using the
-  `:file.position/2` function.
+    * `:stderr` - is a shortcut for `:standard_error`
 
   """
 
@@ -38,6 +34,8 @@ defmodule IO do
   @type nodata :: {:error, term} | :eof
   @type chardata() :: :unicode.chardata()
 
+  import :erlang, only: [group_leader: 0]
+
   defmacrop is_iodata(data) do
     quote do
       is_list(unquote(data)) or is_binary(unquote(data))
@@ -45,15 +43,12 @@ defmodule IO do
   end
 
   @doc """
-  Reads from the IO `device`.
-
-  The `device` is iterated by the given number of characters or line by line if
-  `:line` is given.
-  Alternatively, if `:all` is given, then whole `device` is returned.
+  Reads `count` characters from the IO device, a whole
+  `:line` or the whole device with `:all`.
 
   It returns:
 
-    * `data` - the output characters
+    * `data` - the input characters
 
     * `:eof` - end of file was encountered
 
@@ -65,7 +60,7 @@ defmodule IO do
   empty string in case the device has reached EOF.
   """
   @spec read(device, :all | :line | non_neg_integer) :: chardata | nodata
-  def read(device \\ :stdio, line_or_chars)
+  def read(device \\ group_leader, chars_or_line)
 
   def read(device, :all) do
     do_read_all(map_dev(device), "")
@@ -75,7 +70,7 @@ defmodule IO do
     :io.get_line(map_dev(device), '')
   end
 
-  def read(device, count) when is_integer(count) and count >= 0 do
+  def read(device, count) when count >= 0 do
     :io.get_chars(map_dev(device), '', count)
   end
 
@@ -88,15 +83,12 @@ defmodule IO do
   end
 
   @doc """
-  Reads from the IO `device`. The operation is Unicode unsafe.
-
-  The `device` is iterated by the given number of bytes or line by line if
-  `:line` is given.
-  Alternatively, if `:all` is given, then whole `device` is returned.
+  Reads `count` characters from the IO device, a whole
+  `:line` or the whole device with `:all`.
 
   It returns:
 
-    * `data` - the output bytes
+    * `data` - the input characters
 
     * `:eof` - end of file was encountered
 
@@ -107,11 +99,11 @@ defmodule IO do
   If `:all` is given, `:eof` is never returned, but an
   empty string in case the device has reached EOF.
 
-  Note: do not use this function on IO devices in Unicode mode
+  Note: do not use this function on IO devices in unicode mode
   as it will return the wrong result.
   """
   @spec binread(device, :all | :line | non_neg_integer) :: iodata | nodata
-  def binread(device \\ :stdio, line_or_chars)
+  def binread(device \\ group_leader, chars_or_line)
 
   def binread(device, :all) do
     do_binread_all(map_dev(device), "")
@@ -124,16 +116,15 @@ defmodule IO do
     end
   end
 
-  def binread(device, count) when is_integer(count) and count >= 0 do
+  def binread(device, count) when count >= 0 do
     case :file.read(map_dev(device), count) do
       {:ok, data} -> data
       other -> other
     end
   end
 
-  @read_all_size 4096
   defp do_binread_all(mapped_dev, acc) do
-    case :file.read(mapped_dev, @read_all_size) do
+    case :file.read_line(mapped_dev) do
       {:ok, data} -> do_binread_all(mapped_dev, acc <> data)
       :eof -> acc
       other -> other
@@ -141,189 +132,83 @@ defmodule IO do
   end
 
   @doc """
-  Writes `item` to the given `device`.
+  Writes the given argument to the given device.
 
-  By default the `device` is the standard output.
+  By default the device is the standard output.
   It returns `:ok` if it succeeds.
 
   ## Examples
 
       IO.write "sample"
-      #=> sample
+      #=> "sample"
 
       IO.write :stderr, "error"
-      #=> error
+      #=> "error"
 
   """
   @spec write(device, chardata | String.Chars.t) :: :ok
-  def write(device \\ :stdio, item) do
+  def write(device \\ group_leader(), item) do
     :io.put_chars map_dev(device), to_chardata(item)
   end
 
   @doc """
-  Writes `item` as a binary to the given `device`.
-  No Unicode conversion happens.
-  The operation is Unicode unsafe.
+  Writes the given argument to the given device
+  as a binary, no unicode conversion happens.
 
   Check `write/2` for more information.
 
-  Note: do not use this function on IO devices in Unicode mode
+  Note: do not use this function on IO devices in unicode mode
   as it will return the wrong result.
   """
   @spec binwrite(device, iodata) :: :ok | {:error, term}
-  def binwrite(device \\ :stdio, item) when is_iodata(item) do
+  def binwrite(device \\ group_leader(), item) when is_iodata(item) do
     :file.write map_dev(device), item
   end
 
   @doc """
-  Writes `item` to the given `device`, similar to `write/2`,
-  but adds a newline at the end.
+  Writes the argument to the device, similar to `write/2`,
+  but adds a newline at the end. The argument is expected
+  to be a chardata.
   """
   @spec puts(device, chardata | String.Chars.t) :: :ok
-  def puts(device \\ :stdio, item) do
-    :io.put_chars map_dev(device), [to_chardata(item), ?\n]
+  def puts(device \\ group_leader(), item) do
+    erl_dev = map_dev(device)
+    :io.put_chars erl_dev, [to_chardata(item), ?\n]
   end
 
   @doc """
-  Writes a `message` to stderr, along with the given `stacktrace`.
-
-  This function also notifies the compiler a warning was printed
-  (in case --warnings-as-errors was enabled). It returns `:ok`
-  if it succeeds.
-
-  An empty list can be passed to avoid stacktrace printing.
-
-  ## Examples
-
-      stacktrace = [{MyApp, :main, 1, [file: 'my_app.ex', line: 4]}]
-      IO.warn "variable bar is unused", stacktrace
-      #=> warning: variable bar is unused
-      #=>   my_app.ex:4: MyApp.main/1
-
-  """
-  @spec warn(chardata | String.Chars.t, Exception.stacktrace) :: :ok
-  def warn(message, []) do
-    :elixir_errors.warn([to_chardata(message), ?\n])
-  end
-  def warn(message, stacktrace) when is_list(stacktrace) do
-    formatted = Enum.map_join(stacktrace, "\n  ", &Exception.format_stacktrace_entry(&1))
-    :elixir_errors.warn([to_chardata(message), ?\n, "  ", formatted, ?\n])
-  end
-
-  @doc """
-  Writes a `message` to stderr, along with the current stacktrace.
-
-  It returns `:ok` if it succeeds.
-
-  ## Examples
-
-      IO.warn "variable bar is unused"
-      #=> warning: variable bar is unused
-      #=>   (iex) evaluator.ex:108: IEx.Evaluator.eval/4
-
-  """
-  @spec warn(chardata | String.Chars.t) :: :ok
-  def warn(message) do
-    {:current_stacktrace, stacktrace} = Process.info(self(), :current_stacktrace)
-    warn(message, Enum.drop(stacktrace, 2))
-  end
-
-  @doc """
-  Inspects and writes the given `item` to the device.
-
-  It's important to note that it returns the given `item` unchanged.
-  This makes it possible to "spy" on values by inserting an
-  `IO.inspect/2` call almost anywhere in your code, for example,
-  in the middle of a pipeline.
+  Inspects and writes the given argument to the device.
 
   It enables pretty printing by default with width of
   80 characters. The width can be changed by explicitly
   passing the `:width` option.
 
-  The output can be decorated with a label, by providing the `:label`
-  option to easily distinguish it from other `IO.inspect/2` calls.
-  The label will be printed before the inspected `item`.
-
-  See `Inspect.Opts` for a full list of remaining formatting options.
-
   ## Examples
 
-      IO.inspect <<0, 1, 2>>, width: 40
-
-  Prints:
-
-      <<0, 1, 2>>
-
-  We can use the `:label` option to decorate the output:
-
-      IO.inspect 1..100, label: "a wonderful range"
-
-  Prints:
-
-      a wonderful range: 1..100
-
-  The `:label` option is especially useful with pipelines:
-
-      [1, 2, 3]
-      |> IO.inspect(label: "before")
-      |> Enum.map(&(&1 * 2))
-      |> IO.inspect(label: "after")
-      |> Enum.sum
-
-  Prints:
-
-      before: [1, 2, 3]
-      after: [2, 4, 6]
+      IO.inspect Process.list, width: 40
 
   """
-  @spec inspect(item, keyword) :: item when item: var
+  @spec inspect(term, Keyword.t) :: term
   def inspect(item, opts \\ []) do
-    inspect :stdio, item, opts
+    inspect group_leader(), item, opts
   end
 
   @doc """
-  Inspects `item` according to the given options using the IO `device`.
-
-  See `inspect/2` for a full list of options.
+  Inspects the item with options using the given device.
   """
-  @spec inspect(device, item, keyword) :: item when item: var
+  @spec inspect(device, term, Keyword.t) :: term
   def inspect(device, item, opts) when is_list(opts) do
-    label    = if (label = opts[:label]), do: [to_chardata(label), ": "], else: []
-    opts     = struct(Inspect.Opts, opts)
-    chardata = Inspect.Algebra.format(Inspect.Algebra.to_doc(item, opts), opts.width)
-    puts device, [label, chardata]
+    opts   = struct(Inspect.Opts, opts)
+    iodata = Inspect.Algebra.format(Inspect.Algebra.to_doc(item, opts), opts.width)
+    puts device, iodata
     item
   end
 
   @doc """
-  Gets a number of bytes from IO device `:stdio`.
-
-  If `:stdio` is a Unicode device, `count` implies
-  the number of Unicode codepoints to be retrieved.
+  Gets a number of bytes from the io device. If the
+  io device is a unicode device, `count` implies
+  the number of unicode codepoints to be retrieved.
   Otherwise, `count` is the number of raw bytes to be retrieved.
-
-  See `IO.getn/3` for a description of return values.
-
-  """
-  @spec getn(chardata | String.Chars.t, pos_integer) :: chardata | nodata
-  @spec getn(device, chardata | String.Chars.t) :: chardata | nodata
-  def getn(prompt, count \\ 1)
-
-  def getn(prompt, count) when is_integer(count) and count > 0 do
-    getn(:stdio, prompt, count)
-  end
-
-  def getn(device, prompt) when not is_integer(prompt) do
-    getn(device, prompt, 1)
-  end
-
-  @doc """
-  Gets a number of bytes from the IO `device`.
-
-  If the IO `device` is a Unicode device, `count` implies
-  the number of Unicode codepoints to be retrieved.
-  Otherwise, `count` is the number of raw bytes to be retrieved.
-
   It returns:
 
     * `data` - the input characters
@@ -333,50 +218,58 @@ defmodule IO do
     * `{:error, reason}` - other (rare) error condition;
       for instance, `{:error, :estale}` if reading from an
       NFS volume
+  """
+  @spec getn(chardata | String.Chars.t, pos_integer) :: chardata | nodata
+  @spec getn(device, chardata | String.Chars.t) :: chardata | nodata
+  def getn(prompt, count \\ 1)
 
+  def getn(prompt, count) when is_integer(count) do
+    getn(group_leader, prompt, count)
+  end
+
+  def getn(device, prompt) do
+    getn(device, prompt, 1)
+  end
+
+  @doc """
+  Gets a number of bytes from the io device. If the
+  io device is a unicode device, `count` implies
+  the number of unicode codepoints to be retrieved.
+  Otherwise, `count` is the number of raw bytes to be retrieved.
   """
   @spec getn(device, chardata | String.Chars.t, pos_integer) :: chardata | nodata
-  def getn(device, prompt, count) when is_integer(count) and count > 0 do
+  def getn(device, prompt, count) do
     :io.get_chars(map_dev(device), to_chardata(prompt), count)
   end
 
-  @doc ~S"""
-  Reads a line from the IO `device`.
-
-  It returns:
+  @doc """
+  Reads a line from the IO device. It returns:
 
     * `data` - the characters in the line terminated
-      by a line-feed (LF) or end of file (EOF)
+      by a LF (or end of file)
 
     * `:eof` - end of file was encountered
 
     * `{:error, reason}` - other (rare) error condition;
       for instance, `{:error, :estale}` if reading from an
       NFS volume
-
-  ## Examples
-
-  To display "What is your name?" as a prompt and await user input:
-
-      IO.gets "What is your name?\n"
-
   """
   @spec gets(device, chardata | String.Chars.t) :: chardata | nodata
-  def gets(device \\ :stdio, prompt) do
+  def gets(device \\ group_leader(), prompt) do
     :io.get_line(map_dev(device), to_chardata(prompt))
   end
 
   @doc """
-  Converts the IO `device` into an `IO.Stream`.
+  Converts the io device into a `IO.Stream`.
 
   An `IO.Stream` implements both `Enumerable` and
   `Collectable`, allowing it to be used for both read
   and write.
 
-  The `device` is iterated by the given number of characters or line by line if
-  `:line` is given.
+  The device is iterated line by line if `:line` is given or
+  by a given number of codepoints.
 
-  This reads from the IO as UTF-8. Check out
+  This reads the IO as utf-8. Check out
   `IO.binstream/2` to handle the IO as a raw binary.
 
   Note that an IO stream has side effects and every time
@@ -391,34 +284,28 @@ defmodule IO do
 
   """
   @spec stream(device, :line | pos_integer) :: Enumerable.t
-  def stream(device, line_or_codepoints)
-      when line_or_codepoints == :line
-      when is_integer(line_or_codepoints) and line_or_codepoints > 0 do
+  def stream(device, line_or_codepoints) do
     IO.Stream.__build__(map_dev(device), false, line_or_codepoints)
   end
 
   @doc """
-  Converts the IO `device` into an `IO.Stream`. The operation is Unicode unsafe.
+  Converts the IO device into a `IO.Stream`.
 
   An `IO.Stream` implements both `Enumerable` and
   `Collectable`, allowing it to be used for both read
   and write.
 
-  The `device` is iterated by the given number of bytes or line by line if
-  `:line` is given.
-  This reads from the IO device as a raw binary.
+  The device is iterated line by line or by a number of bytes.
+  This reads the IO device as a raw binary.
 
   Note that an IO stream has side effects and every time
   you go over the stream you may get different results.
 
-  Finally, do not use this function on IO devices in Unicode
+  Finally, do not use this function on IO devices in unicode
   mode as it will return the wrong result.
-
   """
   @spec binstream(device, :line | pos_integer) :: Enumerable.t
-  def binstream(device, line_or_bytes)
-      when line_or_bytes == :line
-      when is_integer(line_or_bytes) and line_or_bytes > 0 do
+  def binstream(device, line_or_bytes) do
     IO.Stream.__build__(map_dev(device), true, line_or_bytes)
   end
 
@@ -426,8 +313,8 @@ defmodule IO do
   Converts chardata (a list of integers representing codepoints,
   lists and strings) into a string.
 
-  In case the conversion fails, it raises an `UnicodeConversionError`.
-  If a string is given, it returns the string itself.
+  In case the conversion fails, it raises a `UnicodeConversionError`.
+  If a string is given, returns the string itself.
 
   ## Examples
 
@@ -437,9 +324,6 @@ defmodule IO do
       iex> IO.chardata_to_string([0x0061, "bc"])
       "abc"
 
-      iex> IO.chardata_to_string("string")
-      "string"
-
   """
   @spec chardata_to_string(chardata) :: String.t | no_return
   def chardata_to_string(string) when is_binary(string) do
@@ -447,17 +331,25 @@ defmodule IO do
   end
 
   def chardata_to_string(list) when is_list(list) do
-    List.to_string(list)
+    case :unicode.characters_to_binary(list) do
+      result when is_binary(result) ->
+        result
+
+      {:error, encoded, rest} ->
+        raise UnicodeConversionError, encoded: encoded, rest: rest, kind: :invalid
+
+      {:incomplete, encoded, rest} ->
+        raise UnicodeConversionError, encoded: encoded, rest: rest, kind: :incomplete
+    end
   end
 
   @doc """
   Converts iodata (a list of integers representing bytes, lists
   and binaries) into a binary.
-  The operation is Unicode unsafe.
 
   Notice that this function treats lists of integers as raw bytes
   and does not perform any kind of encoding conversion. If you want
-  to convert from a charlist to a string (UTF-8 encoded), please
+  to convert from a char list to a string (UTF-8 encoded), please
   use `chardata_to_string/1` instead.
 
   If this function receives a binary, the same binary is returned.
@@ -469,12 +361,12 @@ defmodule IO do
       iex> bin1 = <<1, 2, 3>>
       iex> bin2 = <<4, 5>>
       iex> bin3 = <<6>>
-      iex> IO.iodata_to_binary([bin1, 1, [2, 3, bin2], 4 | bin3])
-      <<1, 2, 3, 1, 2, 3, 4, 5, 4, 6>>
+      iex> IO.iodata_to_binary([bin1, 1, [2, 3, bin2], 4|bin3])
+      <<1,2,3,1,2,3,4,5,4,6>>
 
       iex> bin = <<1, 2, 3>>
       iex> IO.iodata_to_binary(bin)
-      <<1, 2, 3>>
+      <<1,2,3>>
 
   """
   @spec iodata_to_binary(iodata) :: binary
@@ -489,7 +381,7 @@ defmodule IO do
 
   ## Examples
 
-      iex> IO.iodata_length([1, 2 | <<3, 4>>])
+      iex> IO.iodata_length([1, 2|<<3, 4>>])
       4
 
   """
@@ -499,8 +391,8 @@ defmodule IO do
   end
 
   @doc false
-  def each_stream(device, line_or_codepoints) do
-    case read(device, line_or_codepoints) do
+  def each_stream(device, what) do
+    case read(device, what) do
       :eof ->
         {:halt, device}
       {:error, reason} ->
@@ -511,8 +403,8 @@ defmodule IO do
   end
 
   @doc false
-  def each_binstream(device, line_or_chars) do
-    case binread(device, line_or_chars) do
+  def each_binstream(device, what) do
+    case binread(device, what) do
       :eof ->
         {:halt, device}
       {:error, reason} ->
@@ -524,7 +416,7 @@ defmodule IO do
 
   @compile {:inline, map_dev: 1, to_chardata: 1}
 
-  # Map the Elixir names for standard IO and error to Erlang names
+  # Map the Elixir names for standard io and error to Erlang names
   defp map_dev(:stdio),  do: :standard_io
   defp map_dev(:stderr), do: :standard_error
   defp map_dev(other) when is_atom(other) or is_pid(other) or is_tuple(other), do: other

lib/elixir/lib/io/ansi.ex

@@ -1,7 +1,7 @@
 defmodule IO.ANSI.Sequence do
   @moduledoc false
 
-  defmacro defsequence(name, code, terminator \\ "m") do
+  defmacro defsequence(name, code \\ "", terminator \\ "m") do
     quote bind_quoted: [name: name, code: code, terminator: terminator] do
       def unquote(name)() do
         "\e[#{unquote(code)}#{unquote(terminator)}"
@@ -16,25 +16,24 @@ end
 
 defmodule IO.ANSI do
   @moduledoc """
-  Functionality to render ANSI escape sequences.
-
-  [ANSI escape sequences](https://en.wikipedia.org/wiki/ANSI_escape_code)
-  are characters embedded in text used to control formatting, color, and
-  other output options on video text terminals.
+  Functionality to render ANSI escape sequences
+  (http://en.wikipedia.org/wiki/ANSI_escape_code) —  characters embedded
+  in text used to control formatting, color, and other output options
+  on video text terminals.
   """
 
   import IO.ANSI.Sequence
 
-  @type ansicode :: atom
-  @type ansilist :: maybe_improper_list(char | ansicode | binary | ansilist, binary | ansicode | [])
-  @type ansidata :: ansilist | ansicode | binary
+  @typep ansicode :: atom()
+  @typep ansilist :: maybe_improper_list(char() | ansicode() | binary() | ansilist(), binary() | ansicode() | [])
+  @type  ansidata :: ansilist() | ansicode() | binary()
 
   @doc """
   Checks if ANSI coloring is supported and enabled on this machine.
 
   This function simply reads the configuration value for
   `:ansi_enabled` in the `:elixir` application. The value is by
-  default `false` unless Elixir can detect during startup that
+  default false unless Elixir can detect during startup that
   both `stdout` and `stderr` are terminals.
   """
   @spec enabled? :: boolean
@@ -42,141 +41,99 @@ defmodule IO.ANSI do
     Application.get_env(:elixir, :ansi_enabled, false)
   end
 
-  @doc "Sets foreground color."
-  @spec color(0..255) :: String.t
-  def color(code) when code in 0..255, do: "\e[38;5;#{code}m"
-
-  @doc ~S"""
-  Sets the foreground color from individual RGB values.
-
-  Valid values for each color are in the range 0 to 5.
-  """
-  @spec color(0..5, 0..5, 0..5) :: String.t
-  def color(r, g, b) when r in 0..5 and g in 0..5 and b in 0..5 do
-    color(16 + (36 * r) + (6 * g) + b)
-  end
-
-  @doc "Sets background color."
-  @spec color_background(0..255) :: String.t
-  def color_background(code) when code in 0..255, do: "\e[48;5;#{code}m"
-
-  @doc ~S"""
-  Sets the background color from individual RGB values.
-
-  Valid values for each color are in the range 0 to 5.
-  """
-  @spec color_background(0..5, 0..5, 0..5) :: String.t
-  def color_background(r, g, b) when r in 0..5 and g in 0..5 and b in 0..5 do
-    color_background(16 + (36 * r) + (6 * g) + b)
-  end
-
-  @doc "Resets all attributes."
+  @doc "Resets all attributes"
   defsequence :reset, 0
 
-  @doc "Bright (increased intensity) or bold."
+  @doc "Bright (increased intensity) or Bold"
   defsequence :bright, 1
 
-  @doc "Faint (decreased intensity). Not widely supported."
+  @doc "Faint (decreased intensity), not widely supported"
   defsequence :faint, 2
 
   @doc "Italic: on. Not widely supported. Sometimes treated as inverse."
   defsequence :italic, 3
 
-  @doc "Underline: single."
+  @doc "Underline: Single"
   defsequence :underline, 4
 
-  @doc "Blink: slow. Less than 150 per minute."
+  @doc "Blink: Slow. Less than 150 per minute"
   defsequence :blink_slow, 5
 
-  @doc "Blink: rapid. MS-DOS ANSI.SYS; 150 per minute or more; not widely supported."
+  @doc "Blink: Rapid. MS-DOS ANSI.SYS; 150 per minute or more; not widely supported"
   defsequence :blink_rapid, 6
 
-  @doc "Image: negative. Swap foreground and background."
+  @doc "Image: Negative. Swap foreground and background"
   defsequence :inverse, 7
 
-  @doc "Image: negative. Swap foreground and background."
+  @doc "Image: Negative. Swap foreground and background"
   defsequence :reverse, 7
 
-  @doc "Conceal. Not widely supported."
+  @doc "Conceal. Not widely supported"
   defsequence :conceal, 8
 
   @doc "Crossed-out. Characters legible, but marked for deletion. Not widely supported."
   defsequence :crossed_out, 9
 
-  @doc "Sets primary (default) font."
+  @doc "Sets primary (default) font"
   defsequence :primary_font, 10
 
   for font_n <- [1, 2, 3, 4, 5, 6, 7, 8, 9] do
-    @doc "Sets alternative font #{font_n}."
+    @doc "Sets alternative font #{font_n}"
     defsequence :"font_#{font_n}", font_n + 10
   end
 
-  @doc "Normal color or intensity."
+  @doc "Normal color or intensity"
   defsequence :normal, 22
 
-  @doc "Not italic."
+  @doc "Not italic"
   defsequence :not_italic, 23
 
-  @doc "Underline: none."
+  @doc "Underline: None"
   defsequence :no_underline, 24
 
-  @doc "Blink: off."
+  @doc "Blink: off"
   defsequence :blink_off, 25
 
-  @doc "Image: positive. Normal foreground and background."
-  defsequence :inverse_off, 27
-
-  @doc "Image: positive. Normal foreground and background."
-  defsequence :reverse_off, 27
-
   colors = [:black, :red, :green, :yellow, :blue, :magenta, :cyan, :white]
+  colors = Enum.zip(0..(length(colors)-1), colors)
 
-  for {color, code} <- Enum.with_index(colors) do
-    @doc "Sets foreground color to #{color}."
+  for {code, color} <- colors do
+    @doc "Sets foreground color to #{color}"
     defsequence color, code + 30
 
-    @doc "Sets foreground color to light #{color}."
-    defsequence :"light_#{color}", code + 90
-
-    @doc "Sets background color to #{color}."
+    @doc "Sets background color to #{color}"
     defsequence :"#{color}_background", code + 40
-
-    @doc "Sets background color to light #{color}."
-    defsequence :"light_#{color}_background", code + 100
   end
 
-  @doc "Default text color."
+  @doc "Default text color"
   defsequence :default_color, 39
 
-  @doc "Default background color."
+  @doc "Default background color"
   defsequence :default_background, 49
 
-  @doc "Framed."
+  @doc "Framed"
   defsequence :framed, 51
 
-  @doc "Encircled."
+  @doc "Encircled"
   defsequence :encircled, 52
 
-  @doc "Overlined."
+  @doc "Overlined"
   defsequence :overlined, 53
 
-  @doc "Not framed or encircled."
+  @doc "Not framed or encircled"
   defsequence :not_framed_encircled, 54
 
-  @doc "Not overlined."
+  @doc "Not overlined"
   defsequence :not_overlined, 55
 
-  @doc "Sends cursor home."
+  @doc "Send cursor home"
   defsequence :home, "", "H"
 
-  @doc "Clears screen."
+  @doc "Clear screen"
   defsequence :clear, "2", "J"
 
-  @doc "Clears line."
-  defsequence :clear_line, "2", "K"
-
   defp format_sequence(other) do
-    raise ArgumentError, "invalid ANSI sequence specification: #{inspect other}"
+    raise ArgumentError, "invalid ANSI sequence specification: #{other}"
   end
 
   @doc ~S"""
@@ -185,7 +142,7 @@ defmodule IO.ANSI do
 
   The named sequences are represented by atoms.
 
-  It will also append an `IO.ANSI.reset/0` to the chardata when a conversion is
+  It will also append an `IO.ANSI.reset` to the chardata when a conversion is
   performed. If you don't want this behaviour, use `format_fragment/2`.
 
   An optional boolean parameter can be passed to enable or disable
@@ -198,8 +155,8 @@ defmodule IO.ANSI do
       [[[[[[], "Hello, "] | "\e[31m"] | "\e[1m"], "world!"] | "\e[0m"]
 
   """
-  def format(chardata, emit? \\ enabled?()) when is_boolean(emit?) do
-    do_format(chardata, [], [], emit?, :maybe)
+  def format(chardata, emit \\ enabled?) when is_boolean(emit) do
+    do_format(chardata, [], [], emit, :maybe)
   end
 
   @doc ~S"""
@@ -218,12 +175,12 @@ defmodule IO.ANSI do
       [[[[[[] | "\e[1m"], 87], 111], 114], 100]
 
   """
-  def format_fragment(chardata, emit? \\ enabled?()) when is_boolean(emit?) do
-    do_format(chardata, [], [], emit?, false)
+  def format_fragment(chardata, emit \\ enabled?) when is_boolean(emit) do
+    do_format(chardata, [], [], emit, false)
   end
 
-  defp do_format([term | rest], rem, acc, emit?, append_reset) do
-    do_format(term, [rest | rem], acc, emit?, append_reset)
+  defp do_format([term | rest], rem, acc, emit, append_reset) do
+    do_format(term, [rest | rem], acc, emit, append_reset)
   end
 
   defp do_format(term, rem, acc, true, append_reset) when is_atom(term) do
@@ -234,19 +191,19 @@ defmodule IO.ANSI do
     do_format([], rem, acc, false, append_reset)
   end
 
-  defp do_format(term, rem, acc, emit?, append_reset) when not is_list(term) do
-    do_format([], rem, [acc, term], emit?, append_reset)
+  defp do_format(term, rem, acc, emit, append_reset) when not is_list(term) do
+    do_format([], rem, [acc | [term]], emit, append_reset)
   end
 
-  defp do_format([], [next | rest], acc, emit?, append_reset) do
-    do_format(next, rest, acc, emit?, append_reset)
+  defp do_format([], [next | rest], acc, emit, append_reset) do
+    do_format(next, rest, acc, emit, append_reset)
   end
 
   defp do_format([], [], acc, true, true) do
     [acc | IO.ANSI.reset]
   end
 
-  defp do_format([], [], acc, _emit?, _append_reset) do
+  defp do_format([], [], acc, _emit, _append_reset) do
     acc
   end
 end

lib/elixir/lib/io/ansi/docs.ex

@@ -2,7 +2,6 @@ defmodule IO.ANSI.Docs do
   @moduledoc false
 
   @bullets [?*, ?-, ?+]
-  @spaces [" ", "\n", "\t"]
 
   @doc """
   The default options used by this module.
@@ -11,11 +10,11 @@ defmodule IO.ANSI.Docs do
 
     * `:enabled`           - toggles coloring on and off (true)
     * `:doc_bold`          - bold text (bright)
-    * `:doc_code`          - code blocks (cyan)
-    * `:doc_headings`      - h1, h2, h3, h4, h5, h6 headings (yellow)
+    * `:doc_code`          - code blocks (cyan, bright)
+    * `:doc_headings`      - h1 and h2 headings (yellow, bright)
     * `:doc_inline_code`   - inline code (cyan)
     * `:doc_table_heading` - style for table headings
-    * `:doc_title`         - top level heading (reverse, yellow)
+    * `:doc_title`         - top level heading (reverse, yellow, bright)
     * `:doc_underline`     - underlined text (underline)
     * `:width`             - the width to format the text (80)
 
@@ -25,11 +24,11 @@ defmodule IO.ANSI.Docs do
   def default_options do
     [enabled:           true,
      doc_bold:          [:bright],
-     doc_code:          [:cyan],
-     doc_headings:      [:yellow],
+     doc_code:          [:cyan, :bright],
+     doc_headings:      [:yellow, :bright],
      doc_inline_code:   [:cyan],
      doc_table_heading: [:reverse],
-     doc_title:         [:reverse, :yellow],
+     doc_title:         [:reverse, :yellow, :bright],
      doc_underline:     [:underline],
      width:             80]
   end
@@ -41,12 +40,12 @@ defmodule IO.ANSI.Docs do
   """
   def print_heading(heading, options \\ []) do
     IO.puts IO.ANSI.reset
-    options = Keyword.merge(default_options(), options)
+    options = Keyword.merge(default_options, options)
     width   = options[:width]
     padding = div(width + String.length(heading), 2)
-    heading = heading |> String.pad_leading(padding) |> String.pad_trailing(width)
+    heading = heading |> String.rjust(padding) |> String.ljust(width)
     write(:doc_title, heading, options)
-    newline_after_block()
+    newline_after_block
   end
 
   @doc """
@@ -56,10 +55,10 @@ defmodule IO.ANSI.Docs do
   defined in `default_options/1`.
   """
   def print(doc, options \\ []) do
-    options = Keyword.merge(default_options(), options)
+    options = Keyword.merge(default_options, options)
     doc
-    |> String.split(["\r\n", "\n"], trim: false)
-    |> Enum.map(&String.trim_trailing/1)
+    |> String.split(["\r\n","\n"], trim: false)
+    |> Enum.map(&String.rstrip/1)
     |> process([], "", options)
   end
 
@@ -67,23 +66,22 @@ defmodule IO.ANSI.Docs do
     write_text(text, indent, options)
   end
 
-  defp process(["# " <> _ = heading | rest], text, indent, options) do
-    write_heading(heading, rest, text, indent, options)
+  defp process(["# " <> heading | rest], text, indent, options) do
+    write_text(text, indent, options)
+    write_h1(String.strip(heading), options)
+    process(rest, [], "", options)
   end
-  defp process(["## " <> _ = heading | rest], text, indent, options) do
-    write_heading(heading, rest, text, indent, options)
+
+  defp process(["## " <> heading | rest], text, indent, options) do
+    write_text(text, indent, options)
+    write_h2(String.strip(heading), options)
+    process(rest, [], "", options)
   end
-  defp process(["### " <> _ = heading | rest], text, indent, options) do
-    write_heading(heading, rest, text, indent, options)
-  end
-  defp process(["#### " <> _ = heading | rest], text, indent, options) do
-    write_heading(heading, rest, text, indent, options)
-  end
-  defp process(["##### " <> _ = heading | rest], text, indent, options) do
-    write_heading(heading, rest, text, indent, options)
-  end
-  defp process(["###### " <> _ = heading | rest], text, indent, options) do
-    write_heading(heading, rest, text, indent, options)
+
+  defp process(["### " <> heading | rest], text, indent, options) do
+    write_text(text, indent, options)
+    write_h3(String.strip(heading), indent, options)
+    process(rest, [], "", options)
   end
 
   defp process(["" | rest], text, indent, options) do
@@ -96,58 +94,50 @@ defmodule IO.ANSI.Docs do
     process_code(rest, [line], indent, options)
   end
 
-  defp process(["```" <> _line | rest], text, indent, options) do
-    process_fenced_code_block(rest, text, indent, options, _delimiter = "```")
-  end
-
-  defp process(["~~~" <> _line | rest], text, indent, options) do
-    process_fenced_code_block(rest, text, indent, options, _delimiter = "~~~")
-  end
-
-  defp process(all = [line | rest], text, indent, options) do
+  defp process(all=[line | rest], text, indent, options) do
     {stripped, count} = strip_spaces(line, 0, :infinity)
-    cond do
-      link_label?(stripped, count) ->
-        write_text([line], indent, options, true)
-        process(rest, text, indent, options)
-      table_line?(stripped) and rest != [] and table_line?(hd(rest)) ->
-        write_text(text, indent, options)
-        process_table(all, indent, options)
-      true ->
-        process_rest(stripped, rest, count, text, indent, options)
+    if is_table_line?(stripped) and rest != [] and is_table_line?(hd(rest)) do
+      write_text(text, indent, options)
+      process_table(all, indent, options)
+    else
+      case stripped do
+        <<bullet, ?\s, item :: binary>> when bullet in @bullets ->
+          write_text(text, indent, options)
+          process_list("• ", item, rest, count, indent, options)
+        <<d1, ?., ?\s, item :: binary>> when d1 in ?0..?9 ->
+          write_text(text, indent, options)
+          process_list(<<d1, ?., ?\s>>, item, rest, count, indent, options)
+        <<d1, d2, ?., ?\s, item :: binary>> when d1 in ?0..?9 and d2 in ?0..?9 ->
+          write_text(text, indent, options)
+          process_list(<<d1, d2, ?., ?\s>>, item, rest, count, indent, options)
+        _ ->
+          process(rest, [stripped | text], indent, options)
+      end
     end
   end
 
   ## Headings
 
-  defp write_heading(heading, rest, text, indent, options) do
-    write_text(text, indent, options)
+  defp write_h1(heading, options) do
+    write_h2(String.upcase(heading), options)
+  end
+
+  defp write_h2(heading, options) do
     write(:doc_headings, heading, options)
-    newline_after_block()
-    process(rest, [], "", options)
+    newline_after_block
+  end
+
+  defp write_h3(heading, indent, options) do
+    IO.write(indent)
+    write(:doc_headings, heading, options)
+    newline_after_block
   end
 
   ## Lists
 
-  defp process_rest(stripped, rest, count, text, indent, options) do
-    case stripped do
-      <<bullet, ?\s, item::binary>> when bullet in @bullets ->
-        write_text(text, indent, options)
-        process_list("• ", item, rest, count, indent, options)
-      <<d1, ?., ?\s, item::binary>> when d1 in ?0..?9 ->
-        write_text(text, indent, options)
-        process_list(<<d1, ?., ?\s>>, item, rest, count, indent, options)
-      <<d1, d2, ?., ?\s, item::binary>> when d1 in ?0..?9 and d2 in ?0..?9 ->
-        write_text(text, indent, options)
-        process_list(<<d1, d2, ?., ?\s>>, item, rest, count, indent, options)
-      _ ->
-        process(rest, [stripped | text], indent, options)
-    end
-  end
-
   defp process_list(entry, line, rest, count, indent, options) do
     # The first list always win some extra padding
-    entry = if indent == "", do: "  " <> entry, else: entry
+    if indent == "", do: entry = "  " <> entry
     new_indent = indent <> String.duplicate(" ", String.length(entry))
 
     {contents, rest, done} = process_list_next(rest, count, byte_size(new_indent), [])
@@ -172,11 +162,11 @@ defmodule IO.ANSI.Docs do
 
   defp process_list_next_kind(stripped, rest, count, next_count) do
     case {stripped, rest} do
-      {<<bullet, ?\s, _::binary>>, _} when bullet in @bullets and next_count <= count ->
+      {<<bullet, ?\s, _ :: binary>>, _} when bullet in @bullets and next_count <= count ->
         :list
-      {<<d1, ?., ?\s, _::binary>>, _} when d1 in ?0..?9 and next_count <= count ->
+      {<<d1, ?., ?\s, _ :: binary>>, _} when d1 in ?0..?9 and next_count <= count ->
         :list
-      {<<d1, d2, ?., ?\s, _::binary>>, _} when d1 in ?0..?9 and d2 in ?0..?9 and next_count <= count ->
+      {<<d1, d2, ?., ?\s, _ :: binary>>, _} when d1 in ?0..?9 and d2 in ?0..?9 and next_count <= count ->
         :list
       {"", [" " <> _ | _]} ->
         :next
@@ -191,7 +181,7 @@ defmodule IO.ANSI.Docs do
 
   defp write_text(text, indent, options) do
     case Enum.reverse(text) do
-      [:no_wrap | rest] -> write_text(rest, indent, options, true)
+      [:no_wrap|rest] -> write_text(rest, indent, options, true)
       rest -> write_text(rest, indent, options, false)
     end
   end
@@ -204,8 +194,8 @@ defmodule IO.ANSI.Docs do
     lines
     |> Enum.join(" ")
     |> handle_links
-    |> handle_inline(options)
-    |> String.split(@spaces)
+    |> handle_inline(nil, [], [], options)
+    |> String.split(~r{\s})
     |> write_with_wrap(options[:width] - byte_size(indent), indent, no_wrap)
 
     unless no_wrap, do: newline_after_block()
@@ -223,7 +213,7 @@ defmodule IO.ANSI.Docs do
   end
 
   defp process_code(["    " <> line | rest], code, indent, options) do
-    process_code(rest, [line | code], indent, options)
+    process_code(rest, [line|code], indent, options)
   end
 
   defp process_code(rest, code, indent, options) do
@@ -231,34 +221,17 @@ defmodule IO.ANSI.Docs do
     process(rest, [], indent, options)
   end
 
-  defp process_fenced_code_block(rest, text, indent, options, delimiter) do
-    write_text(text, indent, options)
-    process_fenced_code(rest, [], indent, options, delimiter)
-  end
-
-  defp process_fenced_code([], code, indent, options, _delimiter) do
-    write_code(code, indent, options)
-  end
-
-  defp process_fenced_code([line | rest], code, indent, options, delimiter) do
-    if line === delimiter do
-      process_code(rest, code, indent, options)
-    else
-      process_fenced_code(rest, [line | code], indent, options, delimiter)
-    end
-  end
-
   defp write_code(code, indent, options) do
-    write(:doc_code, "#{indent}    #{Enum.join(Enum.reverse(code), "\n#{indent}    ")}", options)
-    newline_after_block()
+    write(:doc_code, "#{indent}┃ #{Enum.join(Enum.reverse(code), "\n#{indent}┃ ")}", options)
+    newline_after_block
   end
 
   ## Tables
 
   defp process_table(lines, indent, options) do
-    {table, rest} = Enum.split_while(lines, &table_line?/1)
+    {table, rest} = Enum.split_while(lines, &is_table_line?/1)
     table_lines(table, options)
-    newline_after_block()
+    newline_after_block
     process(rest, [], indent, options)
   end
 
@@ -267,14 +240,8 @@ defmodule IO.ANSI.Docs do
     count = Enum.map(lines, &length/1) |> Enum.max
     lines = Enum.map(lines, &pad_to_number_of_columns(&1, count))
 
-    widths =
-      for line <- lines do
-        if table_header?(line) do
-          for _ <- line, do: 0
-        else
-          for {_col, length} <- line, do: length
-        end
-      end
+    widths = for line <- lines, do:
+              (for {_col, length} <- line, do: length)
 
     col_widths = Enum.reduce(widths,
                              List.duplicate(0, count),
@@ -285,19 +252,17 @@ defmodule IO.ANSI.Docs do
 
   defp split_into_columns(line, options) do
     line
-    |> String.trim("|")
-    |> String.trim()
-    |> String.split(" | ")
+    |> String.strip(?|)
+    |> String.strip()
+    |> String.split(~r/\s\|\s/)
     |> Enum.map(&render_column(&1, options))
   end
 
   defp render_column(col, options) do
-    col =
-      col
-      |> String.replace("\\\|", "|")
-      |> String.trim()
-      |> handle_links
-      |> handle_inline(options)
+    col = col
+          |> String.replace(~r/\\ \|/x, "|")
+          |> handle_links
+          |> handle_inline(nil, [], [], options)
     {col, length_without_escape(col, 0)}
   end
 
@@ -305,14 +270,12 @@ defmodule IO.ANSI.Docs do
     do: cols ++ List.duplicate({"", 0}, col_count - length(cols))
 
   defp max_column_widths(cols, widths),
-    do: Enum.zip(cols, widths) |> Enum.map(fn {a, b} -> max(a, b) end)
+    do: Enum.zip(cols, widths) |> Enum.map(fn {a,b} -> max(a,b) end)
 
   # If second line is heading separator, use the heading style on the first
   defp render_table([first, second | rest], widths, options) do
     combined = Enum.zip(first, widths)
     if table_header?(second) do
-      alignments = Enum.map(second, &column_alignment/1)
-      options = Keyword.put_new(options, :alignments, alignments)
       draw_table_row(combined, options, :heading)
       render_table(rest, widths, options)
     else
@@ -330,34 +293,14 @@ defmodule IO.ANSI.Docs do
   defp render_table([], _, _),
     do: nil
 
-  defp column_alignment({line, _}) do
-    cond do
-      String.starts_with?(line, ":") and String.ends_with?(line, ":") -> :center
-      String.ends_with?(line, ":") -> :right
-      true -> :left
-    end
-  end
-
-  defp table_header?(row) do
-    Enum.all?(row, fn {col, _} -> table_header_column?(col) end)
-  end
-
-  defp table_header_column?(":" <> row), do: table_header_contents?(row)
-  defp table_header_column?(row), do: table_header_contents?(row)
-
-  defp table_header_contents?("-" <> row), do: table_header_contents?(row)
-  defp table_header_contents?(":"), do: true
-  defp table_header_contents?(""), do: true
-  defp table_header_contents?(_), do: false
+  defp table_header?(row), do:
+    Enum.all?(row, fn {col, _} -> col =~ ~r/^:?-+:?$/ end)
 
   defp draw_table_row(cols_and_widths, options, heading \\ false) do
-    default_alignments = List.duplicate(:left, length(cols_and_widths))
-    alignments = Keyword.get(options, :alignments, default_alignments)
-
     columns =
-      cols_and_widths
-      |> Enum.zip(alignments)
-      |> Enum.map_join(" | ", &generate_table_cell/1)
+      Enum.map_join(cols_and_widths, " | ", fn {{col, length}, width} ->
+        col <> String.duplicate(" ", width - length)
+      end)
 
     if heading do
       write(:doc_table_heading, columns, options)
@@ -366,34 +309,16 @@ defmodule IO.ANSI.Docs do
     end
   end
 
-  defp generate_table_cell({{{col, length}, width}, :center}) do
-    pad = if rem(length, 2) == 0, do: 1, else: rem(width, 2)
-    spaces = div(width, 2) - div(length, 2)
-    String.duplicate(" ", spaces) <> col <> String.duplicate(" ", spaces + pad)
-  end
-
-  defp generate_table_cell({{{col, length}, width}, :right}) do
-    String.duplicate(" ", width - length) <> col
-  end
-
-  defp generate_table_cell({{{col, length}, width}, _}) do
-    col <> String.duplicate(" ", width - length)
-  end
-
-  defp table_line?(line) do
-    line =~ " | "
+  defp is_table_line?(line) do
+    Regex.match?(~r'''
+      ( ^ \s{0,3} \| (?: [^|]+ \|)+ \s* $ )
+    |
+      (\s \| \s)
+    '''x, line)
   end
 
   ## Helpers
 
-  defp link_label?("[" <> rest, count) when count <= 3, do: link_label?(rest)
-  defp link_label?(_, _), do: false
-
-  defp link_label?("]: " <> _), do: true
-  defp link_label?("]" <> _), do: false
-  defp link_label?(""), do: false
-  defp link_label?(<<_>> <> rest), do: link_label?(rest)
-
   defp strip_spaces(" " <> line, acc, max) when acc < max,
     do: strip_spaces(line, acc + 1, max)
   defp strip_spaces(rest, acc, _max),
@@ -413,13 +338,13 @@ defmodule IO.ANSI.Docs do
     write_with_wrap(rest, available, indent, false)
   end
 
-  defp take_words([word | words], available, acc) do
+  defp take_words([word|words], available, acc) do
     available = available - length_without_escape(word, 0)
 
     cond do
       # It fits, take one for space and continue decreasing
       available > 0 ->
-        take_words(words, available - 1, [word | acc])
+        take_words(words, available - 1, [word|acc])
 
       # No space but we got no words
       acc == [] ->
@@ -427,7 +352,7 @@ defmodule IO.ANSI.Docs do
 
       # Otherwise
       true ->
-        {Enum.reverse(acc), [word | words]}
+        {Enum.reverse(acc), [word|words]}
     end
   end
 
@@ -435,11 +360,11 @@ defmodule IO.ANSI.Docs do
     {Enum.reverse(acc), []}
   end
 
-  defp length_without_escape(<<?\e, ?[, _, _, ?m>> <> rest, count) do
+  defp length_without_escape(<< ?\e, ?[, _, _, ?m, rest :: binary >>, count) do
     length_without_escape(rest, count)
   end
 
-  defp length_without_escape(<<?\e, ?[, _, ?m>> <> rest, count) do
+  defp length_without_escape(<< ?\e, ?[, _, ?m, rest :: binary >>, count) do
     length_without_escape(rest, count)
   end
 
@@ -457,126 +382,83 @@ defmodule IO.ANSI.Docs do
   end
 
   defp escape_underlines_in_link(text) do
-    ~r{https?\S*}
-    |> Regex.recompile!
-    |> Regex.replace(text, &String.replace(&1, "_", "\\_"))
+    case Regex.match?(~r{.*(https?\S*)}, text) do
+      true -> Regex.replace(~r{_}, text, "\\\\_")
+      _    -> text
+    end
   end
 
   defp remove_square_brackets_in_link(text) do
-    ~r{\[(.*?)\]\((.*?)\)}
-    |> Regex.recompile!
-    |> Regex.replace(text, "\\1 (\\2)")
+    Regex.replace(~r{\[(.*?)\]\((.*?)\)}, text, "\\1 (\\2)")
   end
 
-  # We have four entries: **, *, _ and `.
-  #
-  # The first three behave the same while the last one is simpler
-  # when it comes to delimiters. But, since the first has two
-  # characters, we need to handle 3 cases:
-  #
-  # 1. **
-  # 2. _ and *
-  # 3. `
-  #
-  # Where the first two should have the same code but match differently.
-  @single [?_, ?*]
+  # Single inline quotes.
+  @single [?`, ?_, ?*]
 
-  # Characters that can mark the beginning or the end of a word.
-  # Only support the most common ones at this moment.
-  @delimiters [?\s, ?', ?", ?!, ?@, ?#, ?$, ?%, ?^, ?&, ?-, ?+, ?(, ?), ?[, ?], ?{, ?}, ?<, ?>, ?.]
+  # ` does not require space in between
+  @spaced [?_, ?*]
 
-  # Inline start
-
-  defp handle_inline(<<?*, ?*, rest::binary>>, options) do
-    handle_inline(rest, ?d, ["**"], [], options)
+  # Clauses for handling spaces
+  defp handle_inline(<<?*, ?*, ?\s, rest :: binary>>, nil, buffer, acc, options) do
+    handle_inline(rest, nil, [?\s, ?*, ?*|buffer], acc, options)
   end
 
-  defp handle_inline(<<mark, rest::binary>>, options) when mark in @single do
-    handle_inline(rest, mark, [<<mark>>], [], options)
+  defp handle_inline(<<mark, ?\s, rest :: binary>>, nil, buffer, acc, options) when mark in @spaced do
+    handle_inline(rest, nil, [?\s, mark|buffer], acc, options)
   end
 
-  defp handle_inline(rest, options) do
-    handle_inline(rest, nil, [], [], options)
+  defp handle_inline(<<?\s, ?*, ?*, rest :: binary>>, limit, buffer, acc, options) do
+    handle_inline(rest, limit, [?*, ?*, ?\s|buffer], acc, options)
   end
 
-  # Inline delimiters
-
-  defp handle_inline(<<delimiter, ?*, ?*, rest::binary>>, nil, buffer, acc, options)
-      when rest != "" and delimiter in @delimiters do
-    handle_inline(rest, ?d, ["**"], [delimiter, Enum.reverse(buffer) | acc], options)
-  end
-
-  defp handle_inline(<<delimiter, mark, rest::binary>>, nil, buffer, acc, options)
-      when rest != "" and delimiter in @delimiters and mark in @single do
-    handle_inline(rest, mark, [<<mark>>], [delimiter, Enum.reverse(buffer) | acc], options)
-  end
-
-  defp handle_inline(<<?`, rest::binary>>, nil, buffer, acc, options)
-      when rest != "" do
-    handle_inline(rest, ?`, ["`"], [Enum.reverse(buffer) | acc], options)
+  defp handle_inline(<<?\s, mark, rest :: binary>>, limit, buffer, acc, options) when mark in @spaced do
+    handle_inline(rest, limit, [mark, ?\s|buffer], acc, options)
   end
 
   # Clauses for handling escape
-
-  defp handle_inline(<<?\\, ?\\, ?*, ?*, rest::binary>>, nil, buffer, acc, options)
-      when rest != "" do
-    handle_inline(rest, ?d, ["**"], [?\\, Enum.reverse(buffer) | acc], options)
+  defp handle_inline(<<?\\, ?\\, rest :: binary>>, limit, buffer, acc, options) do
+    handle_inline(rest, limit, [?\\|buffer], acc, options)
   end
 
-  defp handle_inline(<<?\\, ?\\, mark, rest::binary>>, nil, buffer, acc, options)
-      when rest != "" and mark in @single do
-    handle_inline(rest, mark, [<<mark>>], [?\\, Enum.reverse(buffer) | acc], options)
+  defp handle_inline(<<?\\, ?*, ?*, rest :: binary>>, limit, buffer, acc, options) do
+    handle_inline(rest, limit, [?*, ?*|buffer], acc, options)
   end
 
-  defp handle_inline(<<?\\, ?\\, rest::binary>>, limit, buffer, acc, options) do
-    handle_inline(rest, limit, [?\\ | buffer], acc, options)
+  # A escape is not valid inside `
+  defp handle_inline(<<?\\, mark, rest :: binary>>, limit, buffer, acc, options)
+      when mark in [?_, ?*, ?`] and not(mark == limit and mark == ?`) do
+    handle_inline(rest, limit, [mark|buffer], acc, options)
   end
 
-  # An escape is not valid inside `
-  defp handle_inline(<<?\\, mark, rest::binary>>, limit, buffer, acc, options)
-      when not(mark == limit and mark == ?`) do
-    handle_inline(rest, limit, [mark | buffer], acc, options)
+  # Inline start
+  defp handle_inline(<<?*, ?*, rest :: binary>>, nil, buffer, acc, options) when rest != "" do
+    handle_inline(rest, ?d, ["**"], [Enum.reverse(buffer)|acc], options)
+  end
+
+  defp handle_inline(<<mark, rest :: binary>>, nil, buffer, acc, options) when rest != "" and mark in @single do
+    handle_inline(rest, mark, [<<mark>>], [Enum.reverse(buffer)|acc], options)
   end
 
   # Inline end
-
-  defp handle_inline(<<?*, ?*, delimiter, rest::binary>>, ?d, buffer, acc, options)
-      when delimiter in @delimiters do
-    handle_inline(<<delimiter, rest::binary>>, nil, [], [inline_buffer(buffer, options) | acc], options)
+  defp handle_inline(<<?*, ?*, rest :: binary>>, ?d, buffer, acc, options) do
+    handle_inline(rest, nil, [], [inline_buffer(buffer, options)|acc], options)
   end
 
-  defp handle_inline(<<mark, delimiter, rest::binary>>, mark, buffer, acc, options)
-      when delimiter in @delimiters and mark in @single do
-    handle_inline(<<delimiter, rest::binary>>, nil, [], [inline_buffer(buffer, options) | acc], options)
+  defp handle_inline(<<mark, rest :: binary>>, mark, buffer, acc, options) when mark in @single do
+    handle_inline(rest, nil, [], [inline_buffer(buffer, options)|acc], options)
   end
 
-  defp handle_inline(<<?*, ?*, rest::binary>>, ?d, buffer, acc, options)
-      when rest == "" do
-    handle_inline(<<>>, nil, [], [inline_buffer(buffer, options) | acc], options)
-  end
-
-  defp handle_inline(<<mark, rest::binary>>, mark, buffer, acc, options)
-      when rest == "" and mark in @single do
-    handle_inline(<<>>, nil, [], [inline_buffer(buffer, options) | acc], options)
-  end
-
-  defp handle_inline(<<?`, rest::binary>>, ?`, buffer, acc, options) do
-    handle_inline(rest, nil, [], [inline_buffer(buffer, options) | acc], options)
-  end
-
-  # Catch all
-
-  defp handle_inline(<<char, rest::binary>>, mark, buffer, acc, options) do
-    handle_inline(rest, mark, [char | buffer], acc, options)
+  defp handle_inline(<<char, rest :: binary>>, mark, buffer, acc, options) do
+    handle_inline(rest, mark, [char|buffer], acc, options)
   end
 
   defp handle_inline(<<>>, _mark, buffer, acc, _options) do
-    IO.iodata_to_binary Enum.reverse([Enum.reverse(buffer) | acc])
+    IO.iodata_to_binary Enum.reverse([Enum.reverse(buffer)|acc])
   end
 
   defp inline_buffer(buffer, options) do
-    [h | t] = Enum.reverse([IO.ANSI.reset | buffer])
-    [color_for(h, options) | t]
+    [h|t] = Enum.reverse([IO.ANSI.reset|buffer])
+    [color_for(h, options)|t]
   end
 
   defp color_for(mark, colors) do

lib/elixir/lib/io/stream.ex

@@ -10,7 +10,7 @@ end
 
 defmodule IO.Stream do
   @moduledoc """
-  Defines an `IO.Stream` struct returned by `IO.stream/2` and `IO.binstream/2`.
+  Defines a `IO.Stream` struct returned by `IO.stream/2` and `IO.binstream/2`.
 
   The following fields are public:
 
@@ -18,9 +18,6 @@ defmodule IO.Stream do
     * `raw`           - a boolean indicating if bin functions should be used
     * `line_or_bytes` - if reading should read lines or a given amount of bytes
 
-  It is worth noting that an IO stream has side effects and every time you go
-  over the stream you may get different results.
-
   """
 
   defstruct device: nil, raw: true, line_or_bytes: :line
@@ -33,6 +30,10 @@ defmodule IO.Stream do
   end
 
   defimpl Collectable do
+    def empty(stream) do
+      stream
+    end
+
     def into(%{device: device, raw: raw} = stream) do
       {:ok, into(stream, device, raw)}
     end

lib/elixir/lib/kernel/cli.ex

@@ -12,6 +12,7 @@ defmodule Kernel.CLI do
     argv = for arg <- argv, do: IO.chardata_to_string(arg)
 
     {config, argv} = parse_argv(argv)
+    :elixir_code_server.cast({:paths, config.pa, config.pz})
     System.argv(argv)
 
     run fn _ ->
@@ -33,17 +34,10 @@ defmodule Kernel.CLI do
   by escripts generated by Elixir.
   """
   def run(fun, halt \\ true) do
-    {ok_or_shutdown, status} = exec_fun(fun, {:ok, 0})
-    if ok_or_shutdown == :shutdown or halt do
-      {_, status} = at_exit({ok_or_shutdown, status})
-
-      # Ensure Logger messages are flushed before halting
-      case :erlang.whereis(Logger) do
-        pid when is_pid(pid) -> Logger.flush()
-        _ -> :ok
-      end
-
-      System.halt(status)
+    res = exec_fun(fun, {:ok, 0})
+    if elem(res, 0) == :shutdown or halt do
+      {_, int} = at_exit(res)
+      System.halt(int)
     end
   end
 
@@ -59,24 +53,10 @@ defmodule Kernel.CLI do
     Enum.reverse(config.errors, errors)
   end
 
-  @doc false
-  def format_error(kind, reason, stacktrace) do
-    {blamed, stacktrace} = Exception.blame(kind, reason, stacktrace)
-    iodata =
-      case blamed do
-        %FunctionClauseError{} ->
-          [Exception.format_banner(kind, reason, stacktrace),
-           pad(FunctionClauseError.blame(blamed, &inspect/1, &blame_match/2))]
-        _ ->
-          Exception.format_banner(kind, blamed, stacktrace)
-      end
-    [iodata, ?\n, Exception.format_stacktrace(prune_stacktrace(stacktrace))]
-  end
-
   ## Helpers
 
   defp at_exit(res) do
-    hooks = :elixir_config.get_and_put(:at_exit, [])
+    hooks = :elixir_code_server.call(:flush_at_exit)
     res = Enum.reduce(hooks, res, &exec_fun/2)
     if hooks == [], do: res, else: at_exit(res)
   end
@@ -85,29 +65,29 @@ defmodule Kernel.CLI do
     parent = self()
 
     {pid, ref} =
-      spawn_monitor(fn ->
+      spawn_monitor fn ->
         try do
           fun.(elem(res, 1))
         catch
           :exit, {:shutdown, int} when is_integer(int) ->
-            send parent, {self(), {:shutdown, int}}
+            send parent, {self, {:shutdown, int}}
             exit({:shutdown, int})
           :exit, reason
               when reason == :normal
               when reason == :shutdown
               when tuple_size(reason) == 2 and elem(reason, 0) == :shutdown ->
-            send parent, {self(), {:shutdown, 0}}
+            send parent, {self, {:shutdown, 0}}
             exit(reason)
           kind, reason ->
             stack = System.stacktrace
             print_error(kind, reason, stack)
-            send parent, {self(), {:shutdown, 1}}
-            exit(to_exit(kind, reason, stack))
+            send parent, {self, {:shutdown, 1}}
+            :erlang.raise(kind, reason, stack)
         else
           _ ->
-            send parent, {self(), res}
+            send parent, {self, res}
         end
-      end)
+      end
 
     receive do
       {^pid, res} ->
@@ -119,13 +99,9 @@ defmodule Kernel.CLI do
     end
   end
 
-  defp to_exit(:throw, reason, stack), do: {{:nocatch, reason}, stack}
-  defp to_exit(:error, reason, stack), do: {reason, stack}
-  defp to_exit(:exit, reason, _stack), do: reason
-
   defp shared_option?(list, config, callback) do
     case parse_shared(list, config) do
-      {[h | hs], _} when h == hd(list) ->
+      {[h|hs], _} when h == hd(list) ->
         new_config = %{config | errors: ["#{h} : Unknown option" | config.errors]}
         callback.(hs, new_config)
       {new_list, new_config} ->
@@ -133,47 +109,23 @@ defmodule Kernel.CLI do
     end
   end
 
-  ## Error handling
-
-  defp print_error(kind, reason, stacktrace) do
-    IO.write :stderr, format_error(kind, reason, stacktrace)
+  defp print_error(kind, reason, trace) do
+    IO.puts :stderr, Exception.format(kind, reason, prune_stacktrace(trace))
   end
 
-  defp blame_match(%{match?: true, node: node}, _),
-    do: blame_ansi(:normal, "+", node)
-  defp blame_match(%{match?: false, node: node}, _),
-    do: blame_ansi(:red, "-", node)
-  defp blame_match(_, string),
-    do: string
+  @elixir_internals [:elixir, :elixir_exp, :elixir_compiler, :elixir_module, :elixir_translator,
+                     :elixir_expand, :elixir_lexical]
 
-  defp blame_ansi(color, no_ansi, node) do
-    if IO.ANSI.enabled? do
-      [color | Macro.to_string(node)]
-      |> IO.ANSI.format(true)
-      |> IO.iodata_to_binary()
-    else
-      no_ansi <> Macro.to_string(node) <> no_ansi
-    end
-  end
-
-  defp pad(string) do
-    "    " <> String.replace(string, "\n", "\n    ")
-  end
-
-  @elixir_internals [:elixir, :elixir_expand, :elixir_compiler, :elixir_module,
-                     :elixir_clauses, :elixir_lexical, :elixir_def, :elixir_map,
-                     :elixir_erl, :elixir_erl_clauses, :elixir_erl_pass, Kernel.ErrorHandler]
-
-  defp prune_stacktrace([{mod, _, _, _} | t]) when mod in @elixir_internals do
+  defp prune_stacktrace([{mod, _, _, _}|t]) when mod in @elixir_internals do
     prune_stacktrace(t)
   end
 
-  defp prune_stacktrace([{__MODULE__, :wrapper, 1, _} | _]) do
+  defp prune_stacktrace([{__MODULE__, :wrapper, 1, _}|_]) do
     []
   end
 
-  defp prune_stacktrace([h | t]) do
-    [h | prune_stacktrace(t)]
+  defp prune_stacktrace([h|t]) do
+    [h|prune_stacktrace(t)]
   end
 
   defp prune_stacktrace([]) do
@@ -182,54 +134,48 @@ defmodule Kernel.CLI do
 
   # Parse shared options
 
-  defp parse_shared([opt | _t], _config) when opt in ["-v", "--version"] do
-    if function_exported?(IEx, :started?, 0) and IEx.started? do
-      IO.puts "IEx " <> System.build_info[:build]
-    else
-      IO.puts :erlang.system_info(:system_version)
-      IO.puts "Elixir " <> System.build_info[:build]
-    end
-
+  defp parse_shared([opt|_t], _config) when opt in ["-v", "--version"] do
+    IO.puts "Elixir #{System.version}"
     System.halt 0
   end
 
-  defp parse_shared(["-pa", h | t], config) do
+  defp parse_shared(["-pa", h|t], config) do
     paths = expand_code_path(h)
     Enum.each(paths, &:code.add_patha/1)
     parse_shared t, %{config | pa: config.pa ++ paths}
   end
 
-  defp parse_shared(["-pz", h | t], config) do
+  defp parse_shared(["-pz", h|t], config) do
     paths = expand_code_path(h)
     Enum.each(paths, &:code.add_pathz/1)
     parse_shared t, %{config | pz: config.pz ++ paths}
   end
 
-  defp parse_shared(["--app", h | t], config) do
+  defp parse_shared(["--app", h|t], config) do
     parse_shared t, %{config | commands: [{:app, h} | config.commands]}
   end
 
-  defp parse_shared(["--no-halt" | t], config) do
+  defp parse_shared(["--no-halt"|t], config) do
     parse_shared t, %{config | halt: false}
   end
 
-  defp parse_shared(["-e", h | t], config) do
+  defp parse_shared(["-e", h|t], config) do
     parse_shared t, %{config | commands: [{:eval, h} | config.commands]}
   end
 
-  defp parse_shared(["-r", h | t], config) do
+  defp parse_shared(["-r", h|t], config) do
     parse_shared t, %{config | commands: [{:require, h} | config.commands]}
   end
 
-  defp parse_shared(["-pr", h | t], config) do
+  defp parse_shared(["-pr", h|t], config) do
     parse_shared t, %{config | commands: [{:parallel_require, h} | config.commands]}
   end
 
-  defp parse_shared([erl, _ | t], config) when erl in ["--erl", "--sname", "--name", "--cookie", "--logger-otp-reports", "--logger-sasl-reports"] do
+  defp parse_shared([erl, _|t], config) when erl in ["--erl", "--sname", "--name", "--cookie"] do
     parse_shared t, config
   end
 
-  defp parse_shared([erl | t], config) when erl in ["--detached", "--hidden", "--werl"] do
+  defp parse_shared([erl|t], config) when erl in ["--detached", "--hidden", "--werl"] do
     parse_shared t, config
   end
 
@@ -240,30 +186,30 @@ defmodule Kernel.CLI do
   defp expand_code_path(path) do
     path = Path.expand(path)
     case Path.wildcard(path) do
-      []   -> [to_charlist(path)]
-      list -> Enum.map(list, &to_charlist/1)
+      []   -> [to_char_list(path)]
+      list -> Enum.map(list, &to_char_list/1)
     end
   end
 
   # Process init options
 
-  defp parse_argv(["--" | t], config) do
+  defp parse_argv(["--"|t], config) do
     {config, t}
   end
 
-  defp parse_argv(["+elixirc" | t], config) do
+  defp parse_argv(["+elixirc"|t], config) do
     parse_compiler t, config
   end
 
-  defp parse_argv(["+iex" | t], config) do
+  defp parse_argv(["+iex"|t], config) do
     parse_iex t, config
   end
 
-  defp parse_argv(["-S", h | t], config) do
+  defp parse_argv(["-S", h|t], config) do
     {%{config | commands: [{:script, h} | config.commands]}, t}
   end
 
-  defp parse_argv([h | t] = list, config) do
+  defp parse_argv([h|t] = list, config) do
     case h do
       "-" <> _ ->
         shared_option? list, config, &parse_argv(&1, &2)
@@ -282,35 +228,35 @@ defmodule Kernel.CLI do
 
   # Parse compiler options
 
-  defp parse_compiler(["--" | t], config) do
+  defp parse_compiler(["--"|t], config) do
     {config, t}
   end
 
-  defp parse_compiler(["-o", h | t], config) do
+  defp parse_compiler(["-o", h|t], config) do
     parse_compiler t, %{config | output: h}
   end
 
-  defp parse_compiler(["--no-docs" | t], config) do
+  defp parse_compiler(["--no-docs"|t], config) do
     parse_compiler t, %{config | compiler_options: [{:docs, false} | config.compiler_options]}
   end
 
-  defp parse_compiler(["--no-debug-info" | t], config) do
+  defp parse_compiler(["--no-debug-info"|t], config) do
     parse_compiler t, %{config | compiler_options: [{:debug_info, false} | config.compiler_options]}
   end
 
-  defp parse_compiler(["--ignore-module-conflict" | t], config) do
+  defp parse_compiler(["--ignore-module-conflict"|t], config) do
     parse_compiler t, %{config | compiler_options: [{:ignore_module_conflict, true} | config.compiler_options]}
   end
 
-  defp parse_compiler(["--warnings-as-errors" | t], config) do
+  defp parse_compiler(["--warnings-as-errors"|t], config) do
     parse_compiler t, %{config | compiler_options: [{:warnings_as_errors, true} | config.compiler_options]}
   end
 
-  defp parse_compiler(["--verbose" | t], config) do
+  defp parse_compiler(["--verbose"|t], config) do
     parse_compiler t, %{config | verbose_compile: true}
   end
 
-  defp parse_compiler([h | t] = list, config) do
+  defp parse_compiler([h|t] = list, config) do
     case h do
       "-" <> _ ->
         shared_option? list, config, &parse_compiler(&1, &2)
@@ -321,30 +267,30 @@ defmodule Kernel.CLI do
   end
 
   defp parse_compiler([], config) do
-    {%{config | commands: [{:compile, config.compile} | config.commands]}, []}
+    {%{config | commands: [{:compile, config.compile}|config.commands]}, []}
   end
 
-  # Parse IEx options
+  # Parse iex options
 
-  defp parse_iex(["--" | t], config) do
+  defp parse_iex(["--"|t], config) do
     {config, t}
   end
 
   # This clause is here so that Kernel.CLI does not
   # error out with "unknown option"
-  defp parse_iex(["--dot-iex", _ | t], config) do
+  defp parse_iex(["--dot-iex", _|t], config) do
     parse_iex t, config
   end
 
-  defp parse_iex([opt, _ | t], config) when opt in ["--remsh"] do
+  defp parse_iex([opt, _|t], config) when opt in ["--remsh"] do
     parse_iex t, config
   end
 
-  defp parse_iex(["-S", h | t], config) do
+  defp parse_iex(["-S", h|t], config) do
     {%{config | commands: [{:script, h} | config.commands]}, t}
   end
 
-  defp parse_iex([h | t] = list, config) do
+  defp parse_iex([h|t] = list, config) do
     case h do
       "-" <> _ ->
         shared_option? list, config, &parse_iex(&1, &2)
@@ -427,13 +373,8 @@ defmodule Kernel.CLI do
       {:ok, files} ->
         wrapper fn ->
           Code.compiler_options(config.compiler_options)
-          opts =
-            if config.verbose_compile do
-              [each_long_compilation: &IO.puts("Compiling #{&1} (it's taking more than 5s)")]
-            else
-              []
-            end
-          Kernel.ParallelCompiler.files_to_path(files, config.output, opts)
+          Kernel.ParallelCompiler.files_to_path(files, config.output,
+            each_file: fn file -> if config.verbose_compile do IO.puts "Compiled #{file}" end end)
         end
       {:missing, missing} ->
         {:error, "No files matched pattern(s) #{Enum.join(missing, ",")}"}
@@ -441,24 +382,29 @@ defmodule Kernel.CLI do
   end
 
   defp filter_patterns(pattern) do
-    pattern
-    |> Path.wildcard
-    |> :lists.usort
-    |> Enum.filter(&File.regular?/1)
+    Enum.filter(Enum.uniq(Path.wildcard(pattern)), &File.regular?(&1))
   end
 
   defp filter_multiple_patterns(patterns) do
-    {files, missing} =
-      Enum.reduce patterns, {[], []}, fn pattern, {files, missing} ->
-        case filter_patterns(pattern) do
-          [] -> {files, [pattern | missing]}
-          match -> {match ++ files, missing}
-        end
+    matched_files = Enum.map patterns, fn(pattern) ->
+      case filter_patterns(pattern) do
+        []    -> {:missing, pattern}
+        files -> {:ok, files}
       end
+    end
 
-    case missing do
-      [] -> {:ok, :lists.usort(files)}
-      _  -> {:missing, :lists.usort(missing)}
+    files = Enum.filter_map matched_files,
+       fn(match) -> elem(match, 0) == :ok end,
+       &elem(&1, 1)
+
+    missing_patterns = Enum.filter_map matched_files,
+       fn(match) -> elem(match, 0) == :missing end,
+       &elem(&1, 1)
+
+    if missing_patterns == [] do
+      {:ok, Enum.uniq(Enum.concat(files))}
+    else
+      {:missing,  Enum.uniq(missing_patterns)}
     end
   end
 

lib/elixir/lib/kernel/error_handler.ex

@@ -3,40 +3,38 @@
 defmodule Kernel.ErrorHandler do
   @moduledoc false
 
-  @spec undefined_function(module, atom, list) :: term
   def undefined_function(module, fun, args) do
-    ensure_loaded(module) or ensure_compiled(module, :module)
+    ensure_loaded(module)
     :error_handler.undefined_function(module, fun, args)
   end
 
-  @spec undefined_lambda(module, fun, list) :: term
   def undefined_lambda(module, fun, args) do
-    ensure_loaded(module) or ensure_compiled(module, :module)
+    ensure_loaded(module)
     :error_handler.undefined_lambda(module, fun, args)
   end
 
-  @spec ensure_loaded(module) :: boolean
-  def ensure_loaded(module) do
-    case :code.ensure_loaded(module) do
-      {:module, _} -> true
-      {:error, _} -> false
-    end
+  def release() do
+    # On release, no further allow elixir_ensure_compiled
+    # directives and revert to the original error handler.
+    # Note we should not delete the elixir_compiler_pid though,
+    # as we still want to send notifications to the compiler.
+    :erlang.erase(:elixir_ensure_compiled)
+    :erlang.process_flag(:error_handler, :error_handler)
+    :ok
   end
 
-  @spec ensure_compiled(module, atom) :: boolean
-  # Never wait on nil because it should never be defined.
-  def ensure_compiled(nil, _kind) do
-    false
-  end
-
-  def ensure_compiled(module, kind) do
-    parent = :erlang.get(:elixir_compiler_pid)
-    ref    = :erlang.make_ref
-    send parent, {:waiting, kind, self(), ref, module, :elixir_module.compiler_modules()}
-    :erlang.garbage_collect(self())
-    receive do
-      {^ref, :found}     -> true
-      {^ref, :not_found} -> false
+  defp ensure_loaded(module) do
+    case Code.ensure_loaded(module) do
+      {:module, _} -> :ok
+      {:error, _} ->
+        parent = :erlang.get(:elixir_compiler_pid)
+        ref    = :erlang.make_ref
+        send parent, {:waiting, :module, self(), ref, module}
+        :erlang.garbage_collect(self)
+        receive do
+          {^ref, :ready}   -> :ok
+          {^ref, :release} -> release()
+        end
     end
   end
 end

lib/elixir/lib/kernel/lexical_tracker.ex

@@ -1,6 +1,8 @@
-# This is an Elixir module responsible for tracking references
-# to modules, remote dispatches, and the usage of
-# aliases/imports/requires in the Elixir scope.
+# This is a module Elixir responsible for tracking
+# the usage of aliases, imports and requires in the Elixir scope.
+#
+# The implementation simply stores dispatch information in an
+# ETS table and then consults this table once compilation is done.
 #
 # Note that since this is required for bootstrap, we can't use
 # any of the `GenServer.Behaviour` conveniences.
@@ -9,18 +11,15 @@ defmodule Kernel.LexicalTracker do
   @timeout 30_000
   @behaviour :gen_server
 
-  @doc """
-  Returns all remotes referenced in this lexical scope.
-  """
-  def remote_references(arg) do
-    :gen_server.call(to_pid(arg), :remote_references, @timeout)
-  end
+  @import 2
+  @alias  3
 
   @doc """
-  Returns all remote dispatches in this lexical scope.
+  Returns all remotes linked to in this lexical scope.
   """
-  def remote_dispatches(arg) do
-    :gen_server.call(to_pid(arg), :remote_dispatches, @timeout)
+  def remotes(arg) do
+    ets = :gen_server.call(to_pid(arg), :ets, @timeout)
+    :ets.match(ets, {:"$1", :_, :_}) |> List.flatten
   end
 
   @doc """
@@ -40,7 +39,7 @@ defmodule Kernel.LexicalTracker do
 
   # Internal API
 
-  # Starts the tracker and returns its PID.
+  # Starts the tracker and returns its pid.
   @doc false
   def start_link(dest) do
     :gen_server.start_link(__MODULE__, dest, [])
@@ -52,147 +51,105 @@ defmodule Kernel.LexicalTracker do
   end
 
   @doc false
-  def add_import(pid, module, fas, line, warn) when is_atom(module) do
-    :gen_server.cast(pid, {:add_import, module, fas, line, warn})
+  def add_import(pid, module, line, warn) do
+    :gen_server.cast(pid, {:add_import, module, line, warn})
   end
 
   @doc false
-  def add_alias(pid, module, line, warn) when is_atom(module) do
+  def add_alias(pid, module, line, warn) do
     :gen_server.cast(pid, {:add_alias, module, line, warn})
   end
 
   @doc false
-  def remote_reference(pid, module, mode) when is_atom(module) do
-    :gen_server.cast(pid, {:remote_reference, module, mode})
+  def remote_dispatch(pid, module) do
+    :gen_server.cast(pid, {:remote_dispatch, module})
   end
 
   @doc false
-  def remote_dispatch(pid, module, fa, line, mode) when is_atom(module) do
-    :gen_server.cast(pid, {:remote_dispatch, module, fa, line, mode})
+  def import_dispatch(pid, module) do
+    :gen_server.cast(pid, {:import_dispatch, module})
   end
 
   @doc false
-  def import_dispatch(pid, module, fa, line, mode) when is_atom(module) do
-    :gen_server.cast(pid, {:import_dispatch, module, fa, line, mode})
-  end
-
-  @doc false
-  def alias_dispatch(pid, module) when is_atom(module) do
+  def alias_dispatch(pid, module) do
     :gen_server.cast(pid, {:alias_dispatch, module})
   end
 
-  @doc false
-  def write_cache(pid, value) do
-    key = :erlang.unique_integer()
-    :gen_server.cast(pid, {:write_cache, key, value})
-    key
-  end
-
-  @doc false
-  def read_cache(pid, key) do
-    :gen_server.call(pid, {:read_cache, key}, @timeout)
-  end
-
   @doc false
   def collect_unused_imports(pid) do
-    unused(pid, :import)
+    unused(pid, @import)
   end
 
   @doc false
   def collect_unused_aliases(pid) do
-    unused(pid, :alias)
+    unused(pid, @alias)
   end
 
-  defp unused(pid, tag) do
-    :gen_server.call(pid, {:unused, tag}, @timeout)
+  defp unused(pid, pos) do
+    ets = :gen_server.call(pid, :ets, @timeout)
+    :ets.foldl(fn
+      {module, _, _} = tuple, acc when is_integer(:erlang.element(pos, tuple)) ->
+        [{module, :erlang.element(pos, tuple)}|acc]
+      _, acc ->
+        acc
+    end, [], ets) |> Enum.sort
   end
 
   # Callbacks
 
   def init(dest) do
-    {:ok, %{directives: %{}, references: %{}, compile: %{},
-            runtime: %{}, dest: dest, cache: %{}}}
+    {:ok, {:ets.new(:lexical, [:protected]), dest}}
   end
 
   @doc false
-  def handle_call({:unused, tag}, _from, state) do
-    directives =
-      for {{^tag, module_or_mfa}, marker} <- state.directives,
-          is_integer(marker),
-          do: {module_or_mfa, marker}
-
-    {:reply, Enum.sort(directives), state}
+  def handle_call(:ets, _from, {d, dest}) do
+    {:reply, d, {d, dest}}
   end
 
-  def handle_call(:remote_references, _from, state) do
-    {:reply, partition(Enum.to_list(state.references), [], []), state}
+  def handle_call(:dest, _from, {d, dest}) do
+    {:reply, dest, {d, dest}}
   end
 
-  def handle_call(:remote_dispatches, _from, state) do
-    {:reply, {state.compile, state.runtime}, state}
+  def handle_call(request, _from, {d, dest}) do
+    {:stop, {:bad_call, request}, {d, dest}}
   end
 
-  def handle_call(:dest, _from, state) do
-    {:reply, state.dest, state}
+  def handle_cast({:remote_dispatch, module}, {d, dest}) do
+    add_module(d, module)
+    {:noreply, {d, dest}}
   end
 
-  def handle_call({:read_cache, key}, _from, %{cache: cache} = state) do
-    {:reply, Map.fetch!(cache, key), state}
+  def handle_cast({:import_dispatch, module}, {d, dest}) do
+    add_dispatch(d, module, @import)
+    {:noreply, {d, dest}}
   end
 
-  def handle_cast({:write_cache, key, value}, %{cache: cache} = state) do
-    {:noreply, Map.put(state, :cache, Map.put(cache, key, value))}
+  def handle_cast({:alias_dispatch, module}, {d, dest}) do
+    add_dispatch(d, module, @alias)
+    {:noreply, {d, dest}}
   end
 
-  def handle_cast({:remote_reference, module, mode}, state) do
-    {:noreply, %{state | references: add_reference(state.references, module, mode)}}
+  def handle_cast({:add_import, module, line, warn}, {d, dest}) do
+    add_directive(d, module, line, warn, @import)
+    {:noreply, {d, dest}}
   end
 
-  def handle_cast({:remote_dispatch, module, fa, line, mode}, state) do
-    references = add_reference(state.references, module, mode)
-    state = add_remote_dispatch(state, module, fa, line, mode)
-    {:noreply, %{state | references: references}}
+  def handle_cast({:add_alias, module, line, warn}, {d, dest}) do
+    add_directive(d, module, line, warn, @alias)
+    {:noreply, {d, dest}}
   end
 
-  def handle_cast({:import_dispatch, module, {function, arity} = fa, line, mode}, state) do
-    state =
-      state
-      |> add_import_dispatch(module, function, arity)
-      |> add_remote_dispatch(module, fa, line, mode)
-
-    {:noreply, state}
+  def handle_cast(:stop, {d, dest}) do
+    {:stop, :normal, {d, dest}}
   end
 
-  def handle_cast({:alias_dispatch, module}, state) do
-    {:noreply, %{state | directives: add_dispatch(state.directives, module, :alias)}}
-  end
-
-  def handle_cast({:add_import, module, fas, line, warn}, state) do
-    directives =
-      state.directives
-      |> Enum.reject(&match?({{:import, {^module, _, _}}, _}, &1))
-      |> :maps.from_list
-      |> add_directive(module, line, warn, :import)
-
-    directives =
-      Enum.reduce(fas, directives, fn {function, arity}, directives ->
-        add_directive(directives, {module, function, arity}, line, warn, :import)
-      end)
-
-    {:noreply, %{state | directives: directives}}
-  end
-
-  def handle_cast({:add_alias, module, line, warn}, state) do
-    {:noreply, %{state | directives: add_directive(state.directives, module, line, warn, :alias)}}
-  end
-
-  def handle_cast(:stop, state) do
-    {:stop, :normal, state}
+  def handle_cast(msg, {d, dest}) do
+    {:stop, {:bad_cast, msg}, {d, dest}}
   end
 
   @doc false
-  def handle_info(_msg, state) do
-    {:noreply, state}
+  def handle_info(_msg, {d, dest}) do
+    {:noreply, {d, dest}}
   end
 
   @doc false
@@ -205,62 +162,23 @@ defmodule Kernel.LexicalTracker do
     {:ok, state}
   end
 
-  defp partition([{remote, :compile} | t], compile, runtime),
-    do: partition(t, [remote | compile], runtime)
-  defp partition([{remote, :runtime} | t], compile, runtime),
-    do: partition(t, compile, [remote | runtime])
-  defp partition([], compile, runtime),
-    do: {compile, runtime}
-
   # Callbacks helpers
 
-  defp add_reference(references, module, :runtime) when is_atom(module),
-    do: map_put_new(module, :runtime, references)
-  defp add_reference(references, module, :compile) when is_atom(module),
-    do: :maps.put(module, :compile, references)
-
-  defp add_remote_dispatch(state, module, fa, line, mode) when is_atom(module) do
-    map_update mode, %{module => %{fa => [line]}}, state, fn mode_dispatches ->
-      map_update module, %{fa => [line]}, mode_dispatches, fn module_dispatches ->
-        map_update fa, [line], module_dispatches, &[line | List.delete(&1, line)]
-      end
-    end
-  end
-
-  defp add_import_dispatch(state, module, function, arity) do
-    directives =
-      add_dispatch(state.directives, module, :import)
-      |> add_dispatch({module, function, arity}, :import)
-    # Always compile time because we depend
-    # on the module at compile time
-    references = add_reference(state.references, module, :compile)
-
-    %{state | directives: directives, references: references}
-  end
-
-  # In the map we keep imports and aliases.
+  # In the table we keep imports and aliases.
+  # If the value is false, it was not imported/aliased
+  # If the value is true, it was imported/aliased
   # If the value is a line, it was imported/aliased and has a pending warning
-  # If the value is true, it was imported/aliased and used
-  defp add_directive(directives, module_or_mfa, line, warn, tag) do
+  defp add_module(d, module) do
+    :ets.insert_new(d, {module, false, false})
+  end
+
+  defp add_dispatch(d, module, pos) do
+    :ets.update_element(d, module, {pos, true})
+  end
+
+  defp add_directive(d, module, line, warn, pos) do
+    add_module(d, module)
     marker = if warn, do: line, else: true
-    :maps.put({tag, module_or_mfa}, marker, directives)
-  end
-
-  defp add_dispatch(directives, module_or_mfa, tag) do
-    :maps.put({tag, module_or_mfa}, true, directives)
-  end
-
-  defp map_update(key, initial, map, fun) do
-    case :maps.find(key, map) do
-      {:ok, val} -> :maps.put(key, fun.(val), map)
-      :error -> :maps.put(key, initial, map)
-    end
-  end
-
-  defp map_put_new(key, value, map) do
-    case :maps.find(key, map) do
-      {:ok, _} -> map
-      :error -> :maps.put(key, value, map)
-    end
+    :ets.update_element(d, module, {pos, marker})
   end
 end

lib/elixir/lib/kernel/parallel_compiler.ex

@@ -20,22 +20,12 @@ defmodule Kernel.ParallelCompiler do
     * `:each_file` - for each file compiled, invokes the callback passing the
       file
 
-    * `:each_long_compilation` - for each file that takes more than a given
-      timeout (see the `:long_compilation_threshold` option) to compile, invoke
-      this callback passing the file as its argument
-
-    * `:long_compilation_threshold` - the timeout (in seconds) after the
-      `:each_long_compilation` callback is invoked; defaults to `10`
-
     * `:each_module` - for each module compiled, invokes the callback passing
       the file, module and the module bytecode
 
-    * `:each_warning` - for each warning, invokes the callback passing
-      the file, line number, and warning message
-
-    * `:dest` - the destination directory for the BEAM files. When using `files/2`,
-      this information is only used to properly annotate the BEAM files before
-      they are loaded into memory. If you want a file to actually be written to
+    * `:dest` - the destination directory for the beam files. When using `files/2`,
+      this information is only used to properly annotate the beam files before
+      they are loaded into memory. If you want a file to actually be writen to
       `dest`, use `files_to_path/3` instead.
 
   Returns the modules generated by each compiled file.
@@ -62,136 +52,91 @@ defmodule Kernel.ParallelCompiler do
     :elixir_code_server.cast({:reset_warnings, compiler_pid})
     schedulers = max(:erlang.system_info(:schedulers_online), 2)
 
-    result = spawn_compilers(%{
-      entries: files,
-      original: files,
-      output: path,
-      options: options,
-      waiting: [],
-      queued: [],
-      schedulers: schedulers,
-      result: [],
-    })
+    result = spawn_compilers(files, files, path, options, [], [], schedulers, [])
 
     # In case --warning-as-errors is enabled and there was a warning,
-    # compilation status will be set to error.
+    # compilation status will be set to error and we fail with CompileError
     case :elixir_code_server.call({:compilation_status, compiler_pid}) do
-      :ok ->
-        result
-      :error ->
-        IO.puts :stderr, "Compilation failed due to warnings while using the --warnings-as-errors option"
-        exit({:shutdown, 1})
+      :ok    -> result
+      :error -> exit({:shutdown, 1})
     end
   end
 
-  # We already have n=schedulers currently running, don't spawn new ones
-  defp spawn_compilers(%{queued: queued, waiting: waiting, schedulers: schedulers} = state)
-      when length(queued) - length(waiting) >= schedulers do
-    wait_for_messages(state)
+  # We already have 4 currently running, don't spawn new ones
+  defp spawn_compilers(entries, original, output, options, waiting, queued, schedulers, result) when
+      length(queued) - length(waiting) >= schedulers do
+    wait_for_messages(entries, original, output, options, waiting, queued, schedulers, result)
   end
 
   # Release waiting processes
-  defp spawn_compilers(%{entries: [{ref, found} | t], waiting: waiting} = state) do
-    waiting =
-      case List.keytake(waiting, ref, 2) do
-        {{_kind, pid, ^ref, _on, _defining}, waiting} ->
-          send pid, {ref, found}
-          waiting
-        nil ->
-          waiting
-      end
-    spawn_compilers(%{state | entries: t, waiting: waiting})
+  defp spawn_compilers([h|t], original, output, options, waiting, queued, schedulers, result) when is_pid(h) do
+    {_kind, ^h, ref, _module} = List.keyfind(waiting, h, 1)
+    send h, {ref, :ready}
+    waiting = List.keydelete(waiting, h, 1)
+    spawn_compilers(t, original, output, options, waiting, queued, schedulers, result)
   end
 
-  defp spawn_compilers(%{entries: [file | files], queued: queued, output: output, options: options} = state) do
+  # Spawn a compiler for each file in the list until we reach the limit
+  defp spawn_compilers([h|t], original, output, options, waiting, queued, schedulers, result) do
     parent = self()
 
     {pid, ref} =
       :erlang.spawn_monitor fn ->
+        # Notify Code.ensure_compiled/2 that we should
+        # attempt to compile the module by doing a dispatch.
+        :erlang.put(:elixir_ensure_compiled, true)
+
         # Set the elixir_compiler_pid used by our custom Kernel.ErrorHandler.
         :erlang.put(:elixir_compiler_pid, parent)
-        :erlang.put(:elixir_compiler_file, file)
         :erlang.process_flag(:error_handler, Kernel.ErrorHandler)
 
-        result =
-          try do
-            _ = if output do
-              :elixir_compiler.file_to_path(file, output)
-            else
-              :elixir_compiler.file(file, Keyword.get(options, :dest))
-            end
-            :ok
-          catch
-            kind, reason ->
-              {kind, reason, System.stacktrace}
+        exit(try do
+          _ = if output do
+            :elixir_compiler.file_to_path(h, output)
+          else
+            :elixir_compiler.file(h, Keyword.get(options, :dest))
           end
-
-        send(parent, {:file_compiled, self(), file, result})
-        exit(:shutdown)
+          {:compiled, h}
+        catch
+          kind, reason ->
+            {:failure, kind, reason, System.stacktrace}
+        end)
       end
 
-    timeout = Keyword.get(options, :long_compilation_threshold, 10) * 1_000
-    timer_ref = Process.send_after(self(), {:timed_out, pid}, timeout)
-
-    new_queued = [{pid, ref, file, timer_ref} | queued]
-    spawn_compilers(%{state | entries: files, queued: new_queued})
+    spawn_compilers(t, original, output, options, waiting,
+                    [{pid, ref, h}|queued], schedulers, result)
   end
 
   # No more files, nothing waiting, queue is empty, we are done
-  defp spawn_compilers(%{entries: [], waiting: [], queued: [], result: result}) do
+  defp spawn_compilers([], _original, _output, _options, [], [], _schedulers, result) do
     for {:module, mod} <- result, do: mod
   end
 
   # Queued x, waiting for x: POSSIBLE ERROR! Release processes so we get the failures
-  defp spawn_compilers(%{entries: [], waiting: waiting, queued: queued} = state) when length(waiting) == length(queued) do
-    entries = for {pid, _, _, _} <- queued,
-                  entry = waiting_on_without_definition(waiting, pid),
-                  {_, _, ref, on, _} = entry,
-                  do: {on, {ref, :not_found}}
-
-    # Instead of releasing all files at once, we release them in groups
-    # based on the module they are waiting on. We pick the module being
-    # depended on with less edges, as it is the mostly likely source of
-    # error (for example, someone made a typo). This may not always be
-    # true though: for example, if there is a macro injecting code into
-    # multiple modules and such code becomes faulty, now multiple modules
-    # are waiting on the same module required by the faulty code. However,
-    # since we need to pick something to be first, the one with fewer edges
-    # sounds like a sane choice.
-    entries
-    |> Enum.group_by(&elem(&1, 0), &elem(&1, 1))
-    |> Enum.sort_by(&length(elem(&1, 1)))
-    |> case do
-      [{_on, refs} | _] -> spawn_compilers(%{state | entries: refs})
-      [] -> handle_deadlock(waiting, queued)
+  defp spawn_compilers([], original, output, options, waiting, queued, schedulers, result) when length(waiting) == length(queued) do
+    Enum.each queued, fn {child, _, _} ->
+      {_kind, ^child, ref, _module} = List.keyfind(waiting, child, 1)
+      send child, {ref, :release}
     end
+    wait_for_messages([], original, output, options, waiting, queued, schedulers, result)
   end
 
   # No more files, but queue and waiting are not full or do not match
-  defp spawn_compilers(%{entries: []} = state) do
-    wait_for_messages(state)
-  end
-
-  defp waiting_on_without_definition(waiting, pid) do
-    {_, ^pid, _, on, _} = entry = List.keyfind(waiting, pid, 1)
-    if Enum.any?(waiting, fn {_, _, _, _, defining} -> on in defining end) do
-      nil
-    else
-      entry
-    end
+  defp spawn_compilers([], original, output, options, waiting, queued, schedulers, result) do
+    wait_for_messages([], original, output, options, waiting, queued, schedulers, result)
   end
 
   # Wait for messages from child processes
-  defp wait_for_messages(state) do
-    %{entries: entries, options: options, waiting: waiting, queued: queued, result: result} = state
-
+  defp wait_for_messages(entries, original, output, options, waiting, queued, schedulers, result) do
     receive do
       {:struct_available, module} ->
-        available = for {:struct, _, ref, waiting_module, _defining} <- waiting,
+        available = for {:struct, pid, _, waiting_module} <- waiting,
                         module == waiting_module,
-                        do: {ref, :found}
+                        not pid in entries,
+                        do: pid
 
-        spawn_compilers(%{state | entries: available ++ entries, result: [{:struct, module} | result]})
+        spawn_compilers(available ++ entries, original, output, options,
+                        waiting, queued, schedulers, [{:struct, module}|result])
 
       {:module_available, child, ref, file, module, binary} ->
         if callback = Keyword.get(options, :each_module) do
@@ -201,148 +146,109 @@ defmodule Kernel.ParallelCompiler do
         # Release the module loader which is waiting for an ack
         send child, {ref, :ack}
 
-        available = for {:module, _, ref, waiting_module, _defining} <- waiting,
+        available = for {_kind, pid, _, waiting_module} <- waiting,
                         module == waiting_module,
-                        do: {ref, :found}
+                        not pid in entries,
+                        do: pid
 
-        cancel_waiting_timer(queued, child)
+        spawn_compilers(available ++ entries, original, output, options,
+                        waiting, queued, schedulers, [{:module, module}|result])
 
-        spawn_compilers(%{state | entries: available ++ entries, result: [{:module, module} | result]})
+      {:waiting, kind, child, ref, on} ->
+        defined = fn {k, m} -> on == m and k in [kind, :module] end
 
-      {:waiting, kind, child, ref, on, defining} ->
         # Oops, we already got it, do not put it on waiting.
-        # Alternatively, we're waiting on ourselves,
-        # send :found so that we can crash with a better error.
-        waiting =
-          if :lists.any(&match?({^kind, ^on}, &1), result) or on in defining do
-            send child, {ref, :found}
-            waiting
-          else
-            [{kind, child, ref, on, defining} | waiting]
-          end
-
-        spawn_compilers(%{state | waiting: waiting})
-
-      {:timed_out, child} ->
-        callback = Keyword.get(options, :each_long_compilation)
-        case List.keyfind(queued, child, 0) do
-          {^child, _, file, _} when not is_nil(callback) ->
-            callback.(file)
-          _ ->
-            :ok
+        if :lists.any(defined, result) do
+          send child, {ref, :ready}
+        else
+          waiting = [{kind, child, ref, on}|waiting]
         end
-        spawn_compilers(state)
 
-      {:warning, file, line, message} ->
-        if callback = Keyword.get(options, :each_warning) do
-          callback.(file, line, message)
-        end
-        wait_for_messages(state)
-
-      {:file_compiled, child_pid, file, :ok} ->
-        discard_down(child_pid)
+        spawn_compilers(entries, original, output, options, waiting, queued, schedulers, result)
 
+      {:DOWN, _down_ref, :process, down_pid, {:compiled, file}} ->
         if callback = Keyword.get(options, :each_file) do
           callback.(file)
         end
 
-        cancel_waiting_timer(queued, child_pid)
-
         # Sometimes we may have spurious entries in the waiting
         # list because someone invoked try/rescue UndefinedFunctionError
-        new_entries = List.delete(entries, child_pid)
-        new_queued  = List.keydelete(queued, child_pid, 0)
-        new_waiting = List.keydelete(waiting, child_pid, 1)
-        spawn_compilers(%{state | entries: new_entries, waiting: new_waiting, queued: new_queued})
+        new_entries = List.delete(entries, down_pid)
+        new_queued  = List.keydelete(queued, down_pid, 0)
+        new_waiting = List.keydelete(waiting, down_pid, 1)
+        spawn_compilers(new_entries, original, output, options, new_waiting, new_queued, schedulers, result)
 
-      {:file_compiled, child_pid, file, {kind, reason, stack}} ->
-        discard_down(child_pid)
-        print_error(file, kind, reason, stack)
-        terminate(queued)
-
-      {:DOWN, ref, :process, _pid, reason} ->
-        handle_down(queued, ref, reason)
-        wait_for_messages(state)
+      {:DOWN, down_ref, :process, _down_pid, reason} ->
+        handle_failure(down_ref, reason, entries, waiting, queued)
+        wait_for_messages(entries, original, output, options, waiting, queued, schedulers, result)
     end
   end
 
-  defp discard_down(pid) do
-    receive do
-      {:DOWN, _, :process, ^pid, _} -> :ok
+  defp handle_failure(ref, reason, entries, waiting, queued) do
+    if file = find_failure(ref, queued) do
+      print_failure(file, reason)
+      if all_missing?(entries, waiting, queued) do
+        collect_failures(queued, length(queued) - 1)
+      end
+      exit({:shutdown, 1})
     end
   end
 
-  defp handle_down(_queued, _ref, :normal) do
+  defp find_failure(ref, queued) do
+    case List.keyfind(queued, ref, 1) do
+      {_child, ^ref, file} -> file
+      _ -> nil
+    end
+  end
+
+  defp print_failure(_file, {:compiled, _}) do
     :ok
   end
-  defp handle_down(queued, ref, reason) do
-    case List.keyfind(queued, ref, 1) do
-      {_child, ^ref, file, _timer_ref} ->
-        print_error(file, :exit, reason, [])
-        terminate(queued)
-      _ ->
-        :ok
-    end
+
+  defp print_failure(file, {:failure, kind, reason, stacktrace}) do
+    IO.puts "\n== Compilation error on file #{Path.relative_to_cwd(file)} =="
+    IO.puts Exception.format(kind, reason, prune_stacktrace(stacktrace))
   end
 
-  defp handle_deadlock(waiting, queued) do
-    deadlock =
-      for {pid, _, file, _} <- queued do
-        {:current_stacktrace, stacktrace} = Process.info(pid, :current_stacktrace)
-        Process.exit(pid, :kill)
-
-        {_kind, ^pid, _, on, _} = List.keyfind(waiting, pid, 1)
-        error = CompileError.exception(description: "deadlocked waiting on module #{inspect on}",
-                                       file: nil, line: nil)
-        print_error(file, :error, error, stacktrace)
-
-        {file, on}
-      end
-
-    IO.puts """
-
-    Compilation failed because of a deadlock between files.
-    The following files depended on the following modules:
-    """
-
-    max =
-      deadlock
-      |> Enum.map(& &1 |> elem(0) |> String.length)
-      |> Enum.max
-
-    for {file, mod} <- deadlock do
-      IO.puts ["  ", String.pad_leading(file, max), " => " | inspect(mod)]
-    end
-
-    IO.puts ""
-    exit({:shutdown, 1})
+  defp print_failure(file, reason) do
+    IO.puts "\n== Compilation error on file #{Path.relative_to_cwd(file)} =="
+    IO.puts Exception.format(:exit, reason, [])
   end
 
-  defp terminate(queued) do
-    for {pid, _, _, _} <- queued do
-      Process.exit(pid, :kill)
-    end
-    exit({:shutdown, 1})
+  @elixir_internals [:elixir, :elixir_exp, :elixir_compiler, :elixir_module, :elixir_translator,
+                     :elixir_expand, :elixir_lexical]
+
+  defp prune_stacktrace([{mod, _, _, _}|t]) when mod in @elixir_internals do
+    prune_stacktrace(t)
   end
 
-  defp print_error(file, kind, reason, stack) do
-    IO.write ["\n== Compilation error in file #{Path.relative_to_cwd(file)} ==\n",
-             Kernel.CLI.format_error(kind, reason, stack)]
+  defp prune_stacktrace([h|t]) do
+    [h|prune_stacktrace(t)]
   end
 
-  defp cancel_waiting_timer(queued, child_pid) do
-    case List.keyfind(queued, child_pid, 0) do
-      {^child_pid, _ref, _file, timer_ref} ->
-        Process.cancel_timer(timer_ref)
-        # Let's flush the message in case it arrived before we canceled the
-        # timeout.
-        receive do
-          {:timed_out, ^child_pid} -> :ok
-        after
-          0 -> :ok
+  defp prune_stacktrace([]) do
+    []
+  end
+
+  defp all_missing?(entries, waiting, queued) do
+    entries == [] and waiting != [] and
+      length(waiting) == length(queued)
+  end
+
+  defp collect_failures(_queued, 0), do: :ok
+
+  defp collect_failures(queued, remaining) do
+    receive do
+      {:DOWN, down_ref, :process, _down_pid, reason} ->
+        if file = find_failure(down_ref, queued) do
+          print_failure(file, reason)
+          collect_failures(queued, remaining - 1)
+        else
+          collect_failures(queued, remaining)
         end
-      nil ->
-        :ok
+    after
+      # Give up if no failure appears in 5 seconds
+      5000 -> :ok
     end
   end
 end

lib/elixir/lib/kernel/parallel_require.ex

@@ -3,118 +3,78 @@ defmodule Kernel.ParallelRequire do
   A module responsible for requiring files in parallel.
   """
 
+  defmacrop default_callback, do: quote(do: fn x -> x end)
+
   @doc """
   Requires the given files.
 
-  A callback that will be invoked with each file, or a keyword list of `callbacks` can be provided:
-
-    * `:each_file` - invoked with each file
-
-    * `:each_module` - invoked with file, module name, and binary code
+  A callback that is invoked every time a file is required
+  can be optionally given as argument.
 
   Returns the modules generated by each required file.
   """
-  def files(files, callbacks \\ [])
-
-  def files(files, callback) when is_function(callback, 1) do
-    files(files, [each_file: callback])
-  end
-
-  def files(files, callbacks) when is_list(callbacks) do
-    compiler_pid = self()
-    :elixir_code_server.cast({:reset_warnings, compiler_pid})
+  def files(files, callback \\ default_callback) do
     schedulers = max(:erlang.system_info(:schedulers_online), 2)
-    result = spawn_requires(files, [], callbacks, schedulers, [])
-
-    # In case --warning-as-errors is enabled and there was a warning,
-    # compilation status will be set to error.
-    case :elixir_code_server.call({:compilation_status, compiler_pid}) do
-      :ok ->
-        result
-      :error ->
-        IO.puts :stderr, "\nExecution failed due to warnings while using the --warnings-as-errors option"
-        exit({:shutdown, 1})
-    end
+    spawn_requires(files, [], callback, schedulers, [])
   end
 
-  defp spawn_requires([], [], _callbacks, _schedulers, result), do: result
+  defp spawn_requires([], [], _callback, _schedulers, result), do: result
 
-  defp spawn_requires([], waiting, callbacks, schedulers, result) do
-    wait_for_messages([], waiting, callbacks, schedulers, result)
+  defp spawn_requires([], waiting, callback, schedulers, result) do
+    wait_for_messages([], waiting, callback, schedulers, result)
   end
 
-  defp spawn_requires(files, waiting, callbacks, schedulers, result) when length(waiting) >= schedulers do
-    wait_for_messages(files, waiting, callbacks, schedulers, result)
+  defp spawn_requires(files, waiting, callback, schedulers, result) when length(waiting) >= schedulers do
+    wait_for_messages(files, waiting, callback, schedulers, result)
   end
 
-  defp spawn_requires([file | files], waiting, callbacks, schedulers, result) do
-    parent = self()
+  defp spawn_requires([h|t], waiting, callback, schedulers, result) do
+    parent = self
+
+    compiler_pid    = :erlang.get(:elixir_compiler_pid)
+    ensure_compiled = :erlang.get(:elixir_ensure_compiled)
+    {:error_handler, handler} = :erlang.process_info(parent, :error_handler)
 
     {pid, ref} = :erlang.spawn_monitor fn ->
-      :erlang.put(:elixir_compiler_pid, parent)
-      :erlang.put(:elixir_compiler_file, file)
+      if compiler_pid != :undefined do
+        :erlang.put(:elixir_compiler_pid, compiler_pid)
+      end
 
-      result =
-        try do
-          new = Code.require_file(file) || []
-          {:required, Enum.map(new, &elem(&1, 0))}
-        catch
-          kind, reason ->
-            {kind, reason, System.stacktrace}
-        end
+      if ensure_compiled != :undefined do
+        :erlang.put(:elixir_ensure_compiled, ensure_compiled)
+      end
 
-      send(parent, {:file_required, self(), file, result})
-      exit(:shutdown)
+      :erlang.process_flag(:error_handler, handler)
+
+      exit(try do
+        new = Code.require_file(h) || []
+        {:required, Enum.map(new, &elem(&1, 0)), h}
+      catch
+        kind, reason ->
+          {:failure, kind, reason, System.stacktrace}
+      end)
     end
 
-    spawn_requires(files, [{pid, ref} | waiting], callbacks, schedulers, result)
+    spawn_requires(t, [{pid, ref}|waiting], callback, schedulers, result)
   end
 
-  defp wait_for_messages(files, waiting, callbacks, schedulers, result) do
+  defp wait_for_messages(files, waiting, callback, schedulers, result) do
     receive do
-      {:file_required, pid, file, {:required, mods}} ->
-        discard_down(pid)
-        if each_file_callback = callbacks[:each_file] do
-          each_file_callback.(file)
+      {:DOWN, ref, :process, pid, status} ->
+        tuple = {pid, ref}
+        if tuple in waiting do
+          case status do
+            {:required, mods, file} ->
+              callback.(file)
+              result  = mods ++ result
+              waiting = List.delete(waiting, tuple)
+            {:failure, kind, reason, stacktrace} ->
+              :erlang.raise(kind, reason, stacktrace)
+            other ->
+              :erlang.raise(:exit, other, [])
+          end
         end
-        waiting = List.keydelete(waiting, pid, 0)
-        spawn_requires(files, waiting, callbacks, schedulers, mods ++ result)
-
-      {:file_required, pid, _file, {kind, reason, stacktrace}} ->
-        discard_down(pid)
-        :erlang.raise(kind, reason, stacktrace)
-
-      {:DOWN, ref, :process, pid, reason} ->
-        handle_down(waiting, pid, ref, reason)
-        spawn_requires(files, waiting, callbacks, schedulers, result)
-
-      {:module_available, child, ref, file, module, binary} ->
-        if each_module_callback = callbacks[:each_module] do
-          each_module_callback.(file, module, binary)
-        end
-
-        send(child, {ref, :ack})
-        spawn_requires(files, waiting, callbacks, schedulers, result)
-
-      {:struct_available, _} ->
-        spawn_requires(files, waiting, callbacks, schedulers, result)
-
-      {:waiting, _, child, ref, _, _} ->
-        send(child, {ref, :not_found})
-        spawn_requires(files, waiting, callbacks, schedulers, result)
+        spawn_requires(files, waiting, callback, schedulers, result)
     end
   end
-
-  defp discard_down(pid) do
-    receive do
-      {:DOWN, _, :process, ^pid, _} -> :ok
-    end
-  end
-
-  defp handle_down(waiting, pid, ref, reason) do
-    if reason != :normal and {pid, ref} in waiting do
-      :erlang.raise(:exit, reason, [])
-    end
-    :ok
-  end
 end

lib/elixir/lib/kernel/utils.ex

@@ -1,125 +0,0 @@
-import Kernel, except: [destructure: 2, defdelegate: 2, defstruct: 2]
-
-defmodule Kernel.Utils do
-  @moduledoc false
-
-  @doc """
-  Callback for destructure.
-  """
-  def destructure(list, count) when is_list(list) and is_integer(count) and count >= 0,
-    do: destructure_list(list, count)
-  def destructure(nil, count) when is_integer(count) and count >= 0,
-    do: destructure_nil(count)
-
-  defp destructure_list(_, 0), do: []
-  defp destructure_list([], count), do: destructure_nil(count)
-  defp destructure_list([h | t], count), do: [h | destructure_list(t, count - 1)]
-
-  defp destructure_nil(0), do: []
-  defp destructure_nil(count), do: [nil | destructure_nil(count - 1)]
-
-  @doc """
-  Callback for defdelegate.
-  """
-  def defdelegate(fun, opts) when is_list(opts) do
-    # TODO: Remove by 2.0
-    append_first? = Keyword.get(opts, :append_first, false)
-
-    {name, args} =
-      case Macro.decompose_call(fun) do
-        {_, _} = pair -> pair
-        _ -> raise ArgumentError, "invalid syntax in defdelegate #{Macro.to_string(fun)}"
-      end
-
-    as = Keyword.get(opts, :as, name)
-    as_args = build_as_args(args, append_first?)
-
-    {name, args, as, as_args}
-  end
-
-  defp build_as_args(args, append_first?) do
-    as_args = :lists.map(&build_as_arg/1, args)
-
-    case append_first? do
-      true -> tl(as_args) ++ [hd(as_args)]
-      false -> as_args
-    end
-  end
-
-  defp build_as_arg({:\\, _, [arg, _default_arg]}), do: validate_arg(arg)
-  defp build_as_arg(arg), do: validate_arg(arg)
-
-  defp validate_arg({name, _, mod} = arg) when is_atom(name) and is_atom(mod) do
-    arg
-  end
-
-  defp validate_arg(ast) do
-    raise ArgumentError, "defdelegate/2 only accepts function parameters, got: #{Macro.to_string(ast)}"
-  end
-
-  @doc """
-  Callback for defstruct.
-  """
-  def defstruct(module, fields) do
-    case fields do
-      fs when is_list(fs) ->
-        :ok
-      other ->
-        raise ArgumentError, "struct fields definition must be list, got: #{inspect other}"
-    end
-
-    fields = :lists.map(fn
-      {key, val} when is_atom(key) ->
-        try do
-          Macro.escape(val)
-        rescue
-          e in [ArgumentError] ->
-            raise ArgumentError, "invalid value for struct field #{key}, " <> Exception.message(e)
-        else
-          _ -> {key, val}
-        end
-      key when is_atom(key) ->
-        {key, nil}
-      other ->
-        raise ArgumentError, "struct field names must be atoms, got: #{inspect other}"
-    end, fields)
-
-    enforce_keys = List.wrap(Module.get_attribute(module, :enforce_keys))
-
-    :lists.foreach(fn
-      key when is_atom(key) -> :ok
-      key -> raise ArgumentError, "keys given to @enforce_keys must be atoms, got: #{inspect key}"
-    end, enforce_keys)
-
-    {:maps.put(:__struct__, module, :maps.from_list(fields)),
-     enforce_keys,
-     Module.get_attribute(module, :derive)}
-  end
-
-  @doc """
-  Announcing callback for defstruct.
-  """
-  def announce_struct(module) do
-    case :erlang.get(:elixir_compiler_pid) do
-      :undefined -> :ok
-      pid -> send(pid, {:struct_available, module})
-    end
-  end
-
-  @doc """
-  Callback for raise.
-  """
-  def raise(msg) when is_binary(msg) do
-    RuntimeError.exception(msg)
-  end
-  def raise(atom) when is_atom(atom) do
-    atom.exception([])
-  end
-  def raise(%{__struct__: struct, __exception__: true} = exception) when is_atom(struct) do
-    exception
-  end
-  def raise(other) do
-    ArgumentError.exception("raise/1 expects a module name, string or exception as " <>
-                            "the first argument, got: #{inspect other}")
-  end
-end

lib/elixir/lib/list.ex

@@ -1,125 +1,41 @@
 defmodule List do
   @moduledoc """
-  Functions that work on (linked) lists.
+  Implements functions that only make sense for lists
+  and cannot be part of the Enum protocol. In general,
+  favor using the Enum API instead of List.
 
-  Lists in Elixir are specified between square brackets:
+  Some functions in this module expect an index. Index
+  access for list is linear. Negative indexes are also
+  supported but they imply the list will be iterated twice,
+  one to calculate the proper index and another to the
+  operation.
 
-      iex> [1, "two", 3, :four]
-      [1, "two", 3, :four]
-
-  Two lists can be concatenated and subtracted using the
-  `Kernel.++/2` and `Kernel.--/2` operators:
-
-      iex> [1, 2, 3] ++ [4, 5, 6]
-      [1, 2, 3, 4, 5, 6]
-      iex> [1, true, 2, false, 3, true] -- [true, false]
-      [1, 2, 3, true]
-
-  Lists in Elixir are effectively linked lists, which means
-  they are internally represented in pairs containing the
-  head and the tail of a list:
-
-      iex> [head | tail] = [1, 2, 3]
-      iex> head
-      1
-      iex> tail
-      [2, 3]
-
-  Similarly, we could write the list `[1, 2, 3]` using only
-  such pairs (called cons cells):
-
-      iex> [1 | [2 | [3 | []]]]
-      [1, 2, 3]
-
-  Some lists, called improper lists, do not have an empty list as
-  the second element in the last cons cell:
-
-      iex> [1 | [2 | [3 | 4]]]
-      [1, 2, 3 | 4]
-
-  Although improper lists are generally avoided, they are used in some
-  special circumstances like iodata and chardata entities (see the `IO` module).
-
-  Due to their cons cell based representation, prepending an element
-  to a list is always fast (constant time), while appending becomes
-  slower as the list grows in size (linear time):
-
-      iex> list = [1, 2, 3]
-      iex> [0 | list]   # fast
-      [0, 1, 2, 3]
-      iex> list ++ [4]  # slow
-      [1, 2, 3, 4]
-
-  The `Kernel` module contains many functions to manipulate lists
-  and that are allowed in guards. For example, `Kernel.hd/1` to
-  retrieve the head, `Kernel.tl/1` to fetch the tail and
-  `Kernel.length/1` for calculating the length. Keep in mind that,
-  similar to appending to a list, calculating the length needs to
-  traverse the whole list.
-
-  ## Charlists
-
-  If a list is made of non-negative integers, it can also be called
-  a charlist. Elixir uses single quotes to define charlists:
-
-      iex> 'héllo'
-      [104, 233, 108, 108, 111]
-
-  In particular, charlists may be printed back in single
-  quotes if they contain only ASCII-printable codepoints:
-
-      iex> 'abc'
-      'abc'
-
-  The rationale behind this behaviour is to better support
-  Erlang libraries which may return text as charlists
-  instead of Elixir strings. One example of such functions
-  is `Application.loaded_applications/0`:
-
-      Application.loaded_applications
-      #=>  [{:stdlib, 'ERTS  CXC 138 10', '2.6'},
-            {:compiler, 'ERTS  CXC 138 10', '6.0.1'},
-            {:elixir, 'elixir', '1.0.0'},
-            {:kernel, 'ERTS  CXC 138 10', '4.1'},
-            {:logger, 'logger', '1.0.0'}]
-
-  ## List and Enum modules
-
-  This module aims to provide operations that are specific
-  to lists, like conversion between data types, updates,
-  deletions and key lookups (for lists of tuples). For traversing
-  lists in general, developers should use the functions in the
-  `Enum` module that work across a variety of data types.
-
-  In both `Enum` and `List` modules, any kind of index access
-  on a list is linear. Negative indexes are also supported but
-  they imply the list will be iterated twice, one to calculate
-  the proper index and another to perform the operation.
+  A decision was taken to delegate most functions to
+  Erlang's standard library but follow Elixir's convention
+  of receiving the target (in this case, a list) as the
+  first argument.
   """
 
   @compile :inline_list_funcs
 
   @doc """
-  Deletes the given `item` from the `list`. Returns a new list without
-  the item.
-
-  If the `item` occurs more than once in the `list`, just
+  Deletes the given item from the list. Returns a list without
+  the item. If the item occurs more than once in the list, just
   the first occurrence is removed.
 
   ## Examples
 
-      iex> List.delete([:a, :b, :c], :a)
-      [:b, :c]
+      iex> List.delete([1, 2, 3], 1)
+      [2,3]
 
-      iex> List.delete([:a, :b, :b, :c], :b)
-      [:a, :b, :c]
+      iex> List.delete([1, 2, 2, 3], 2)
+      [1, 2, 3]
 
   """
   @spec delete(list, any) :: list
-  def delete(list, item)
-  def delete([item | list], item), do: list
-  def delete([other | list], item), do: [other | delete(list, item)]
-  def delete([], _item), do: []
+  def delete(list, item) do
+    :lists.delete(item, list)
+  end
 
   @doc """
   Duplicates the given element `n` times in a list.
@@ -127,10 +43,10 @@ defmodule List do
   ## Examples
 
       iex> List.duplicate("hello", 3)
-      ["hello", "hello", "hello"]
+      ["hello","hello","hello"]
 
       iex> List.duplicate([1, 2], 2)
-      [[1, 2], [1, 2]]
+      [[1,2],[1,2]]
 
   """
   @spec duplicate(elem, non_neg_integer) :: [elem] when elem: var
@@ -144,7 +60,7 @@ defmodule List do
   ## Examples
 
       iex> List.flatten([1, [[2], 3]])
-      [1, 2, 3]
+      [1,2,3]
 
   """
   @spec flatten(deep_list) :: list when deep_list: [any | deep_list]
@@ -160,7 +76,7 @@ defmodule List do
   ## Examples
 
       iex> List.flatten([1, [[2], 3]], [4, 5])
-      [1, 2, 3, 4, 5]
+      [1,2,3,4,5]
 
   """
   @spec flatten(deep_list, [elem]) :: [elem] when elem: var, deep_list: [elem | deep_list]
@@ -169,15 +85,15 @@ defmodule List do
   end
 
   @doc """
-  Folds (reduces) the given list from the left with
+  Folds (reduces) the given list to the left with
   a function. Requires an accumulator.
 
   ## Examples
 
-      iex> List.foldl([5, 5], 10, fn(x, acc) -> x + acc end)
+      iex> List.foldl([5, 5], 10, fn (x, acc) -> x + acc end)
       20
 
-      iex> List.foldl([1, 2, 3, 4], 0, fn(x, acc) -> x - acc end)
+      iex> List.foldl([1, 2, 3, 4], 0, fn (x, acc) -> x - acc end)
       2
 
   """
@@ -187,12 +103,12 @@ defmodule List do
   end
 
   @doc """
-  Folds (reduces) the given list from the right with
+  Folds (reduces) the given list to the right with
   a function. Requires an accumulator.
 
   ## Examples
 
-      iex> List.foldr([1, 2, 3, 4], 0, fn(x, acc) -> x - acc end)
+      iex> List.foldr([1, 2, 3, 4], 0, fn (x, acc) -> x - acc end)
       -2
 
   """
@@ -217,8 +133,8 @@ defmodule List do
 
   """
   @spec first([elem]) :: nil | elem when elem: var
-  def first([]),      do: nil
-  def first([head | _]), do: head
+  def first([]),    do: nil
+  def first([h|_]), do: h
 
   @doc """
   Returns the last element in `list` or `nil` if `list` is empty.
@@ -236,14 +152,14 @@ defmodule List do
 
   """
   @spec last([elem]) :: nil | elem when elem: var
-  def last([]), do: nil
-  def last([head]), do: head
-  def last([_ | tail]), do: last(tail)
+  def last([]),    do: nil
+  def last([h]),   do: h
+  def last([_|t]), do: last(t)
 
   @doc """
   Receives a list of tuples and returns the first tuple
   where the item at `position` in the tuple matches the
-  given `key`.
+  given `item`.
 
   ## Examples
 
@@ -265,7 +181,7 @@ defmodule List do
   @doc """
   Receives a list of tuples and returns `true` if there is
   a tuple where the item at `position` in the tuple matches
-  the given `key`.
+  the given `item`.
 
   ## Examples
 
@@ -279,7 +195,7 @@ defmodule List do
       false
 
   """
-  @spec keymember?([tuple], any, non_neg_integer) :: boolean
+  @spec keymember?([tuple], any, non_neg_integer) :: any
   def keymember?(list, key, position) do
     :lists.keymember(key, position + 1, list)
   end
@@ -318,10 +234,9 @@ defmodule List do
   end
 
   @doc """
-  Receives a `list` of tuples and replaces the item
-  identified by `key` at `position`.
-
-  If the item does not exist, it is added to the end of the `list`.
+  Receives a list of tuples and replaces the item
+  identified by `key` at `position`. If the item
+  does not exist, it is added to the end of the list.
 
   ## Examples
 
@@ -338,9 +253,9 @@ defmodule List do
   end
 
   @doc """
-  Receives a `list` of tuples and deletes the first tuple
+  Receives a list of tuples and deletes the first tuple
   where the item at `position` matches the
-  given `key`. Returns the new list.
+  given `item`. Returns the new list.
 
   ## Examples
 
@@ -359,36 +274,8 @@ defmodule List do
     :lists.keydelete(key, position + 1, list)
   end
 
-  @doc """
-  Receives a `list` of tuples and returns the first tuple
-  where the element at `position` in the tuple matches the
-  given `key`, as well as the `list` without found tuple.
-
-  If such a tuple is not found, `nil` will be returned.
-
-  ## Examples
-
-      iex> List.keytake([a: 1, b: 2], :a, 0)
-      {{:a, 1}, [b: 2]}
-
-      iex> List.keytake([a: 1, b: 2], 2, 1)
-      {{:b, 2}, [a: 1]}
-
-      iex> List.keytake([a: 1, b: 2], :c, 0)
-      nil
-
-  """
-  @spec keytake([tuple], any, non_neg_integer) :: {tuple, [tuple]} | nil
-  def keytake(list, key, position) do
-    case :lists.keytake(key, position + 1, list) do
-      {:value, item, list} -> {item, list}
-      false                -> nil
-    end
-  end
-
   @doc """
   Wraps the argument in a list.
-
   If the argument is already a list, returns the list.
   If the argument is `nil`, returns an empty list.
 
@@ -398,7 +285,7 @@ defmodule List do
       ["hello"]
 
       iex> List.wrap([1, 2, 3])
-      [1, 2, 3]
+      [1,2,3]
 
       iex> List.wrap(nil)
       []
@@ -439,9 +326,8 @@ defmodule List do
 
   @doc """
   Returns a list with `value` inserted at the specified `index`.
-
   Note that `index` is capped at the list length. Negative indices
-  indicate an offset from the end of the `list`.
+  indicate an offset from the end of the list.
 
   ## Examples
 
@@ -459,7 +345,7 @@ defmodule List do
 
   """
   @spec insert_at(list, integer, any) :: list
-  def insert_at(list, index, value) when is_integer(index) do
+  def insert_at(list, index, value) do
     if index < 0 do
       do_insert_at(list, length(list) + index + 1, value)
     else
@@ -469,8 +355,7 @@ defmodule List do
 
   @doc """
   Returns a list with a replaced value at the specified `index`.
-
-  Negative indices indicate an offset from the end of the `list`.
+  Negative indices indicate an offset from the end of the list.
   If `index` is out of bounds, the original `list` is returned.
 
   ## Examples
@@ -489,7 +374,7 @@ defmodule List do
 
   """
   @spec replace_at(list, integer, any) :: list
-  def replace_at(list, index, value) when is_integer(index) do
+  def replace_at(list, index, value) do
     if index < 0 do
       do_replace_at(list, length(list) + index, value)
     else
@@ -499,8 +384,7 @@ defmodule List do
 
   @doc """
   Returns a list with an updated value at the specified `index`.
-
-  Negative indices indicate an offset from the end of the `list`.
+  Negative indices indicate an offset from the end of the list.
   If `index` is out of bounds, the original `list` is returned.
 
   ## Examples
@@ -519,7 +403,7 @@ defmodule List do
 
   """
   @spec update_at([elem], integer, (elem -> any)) :: list when elem: var
-  def update_at(list, index, fun) when is_function(fun, 1) and is_integer(index) do
+  def update_at(list, index, fun) do
     if index < 0 do
       do_update_at(list, length(list) + index, fun)
     else
@@ -529,8 +413,7 @@ defmodule List do
 
   @doc """
   Produces a new list by removing the value at the specified `index`.
-
-  Negative indices indicate an offset from the end of the `list`.
+  Negative indices indicate an offset from the end of the list.
   If `index` is out of bounds, the original `list` is returned.
 
   ## Examples
@@ -538,7 +421,7 @@ defmodule List do
       iex> List.delete_at([1, 2, 3], 0)
       [2, 3]
 
-      iex> List.delete_at([1, 2, 3], 10)
+      iex List.delete_at([1, 2, 3], 10)
       [1, 2, 3]
 
       iex> List.delete_at([1, 2, 3], -1)
@@ -546,73 +429,18 @@ defmodule List do
 
   """
   @spec delete_at(list, integer) :: list
-  def delete_at(list, index) when is_integer(index) do
-    elem(pop_at(list, index), 1)
-  end
-
-  @doc """
-  Returns and removes the value at the specified `index` in the `list`.
-
-  Negative indices indicate an offset from the end of the `list`.
-  If `index` is out of bounds, the original `list` is returned.
-
-  ## Examples
-
-      iex> List.pop_at([1, 2, 3], 0)
-      {1, [2, 3]}
-      iex> List.pop_at([1, 2, 3], 5)
-      {nil, [1, 2, 3]}
-      iex> List.pop_at([1, 2, 3], 5, 10)
-      {10, [1, 2, 3]}
-      iex> List.pop_at([1, 2, 3], -1)
-      {3, [1, 2]}
-
-  """
-  @spec pop_at(list, integer, any) :: {any, list}
-  def pop_at(list, index, default \\ nil) when is_integer(index) do
+  def delete_at(list, index) do
     if index < 0 do
-      do_pop_at(list, length(list) + index, default, [])
+      do_delete_at(list, length(list) + index)
     else
-      do_pop_at(list, index, default, [])
+      do_delete_at(list, index)
     end
   end
 
   @doc """
-  Returns `true` if `list` starts with the given `prefix` list; otherwise returns `false`.
+  Converts a char list to an atom.
 
-  If `prefix` is an empty list, it returns `true`.
-
-  ### Examples
-
-      iex> List.starts_with?([1, 2, 3], [1, 2])
-      true
-
-      iex> List.starts_with?([1, 2], [1, 2, 3])
-      false
-
-      iex> List.starts_with?([:alpha], [])
-      true
-
-      iex> List.starts_with?([], [:alpha])
-      false
-
-  """
-  @spec starts_with?(list, list) :: boolean
-  @spec starts_with?(list, []) :: true
-  @spec starts_with?([], nonempty_list) :: false
-  def starts_with?(list, prefix)
-
-  def starts_with?([head | tail], [head | prefix_tail]),
-    do: starts_with?(tail, prefix_tail);
-  def starts_with?(list, []) when is_list(list),
-    do: true
-  def starts_with?(list, [_ | _]) when is_list(list),
-    do: false
-
-  @doc """
-  Converts a charlist to an atom.
-
-  Currently Elixir does not support conversions from charlists
+  Currently Elixir does not support conversions from char lists
   which contains Unicode codepoints greater than 0xFF.
 
   Inlined by the compiler.
@@ -623,37 +451,26 @@ defmodule List do
       :elixir
 
   """
-  @spec to_atom(charlist) :: atom
-  def to_atom(charlist) do
-    :erlang.list_to_atom(charlist)
+  @spec to_atom(char_list) :: atom
+  def to_atom(char_list) do
+    :erlang.list_to_atom(char_list)
   end
 
   @doc """
-  Converts a charlist to an existing atom. Raises an `ArgumentError`
-  if the atom does not exist.
+  Converts a char list to an existing atom.
 
-  Currently Elixir does not support conversions from charlists
+  Currently Elixir does not support conversions from char lists
   which contains Unicode codepoints greater than 0xFF.
 
   Inlined by the compiler.
-
-  ## Examples
-
-      iex> _ = :my_atom
-      iex> List.to_existing_atom('my_atom')
-      :my_atom
-
-      iex> List.to_existing_atom('this_atom_will_never_exist')
-      ** (ArgumentError) argument error
-
   """
-  @spec to_existing_atom(charlist) :: atom
-  def to_existing_atom(charlist) do
-    :erlang.list_to_existing_atom(charlist)
+  @spec to_existing_atom(char_list) :: atom
+  def to_existing_atom(char_list) do
+    :erlang.list_to_existing_atom(char_list)
   end
 
   @doc """
-  Returns the float whose text representation is `charlist`.
+  Returns the float whose text representation is `char_list`.
 
   Inlined by the compiler.
 
@@ -663,13 +480,13 @@ defmodule List do
       2.2017764
 
   """
-  @spec to_float(charlist) :: float
-  def to_float(charlist) do
-    :erlang.list_to_float(charlist)
+  @spec to_float(char_list) :: float
+  def to_float(char_list) do
+    :erlang.list_to_float(char_list)
   end
 
   @doc """
-  Returns an integer whose text representation is `charlist`.
+  Returns an integer whose text representation is `char_list`.
 
   Inlined by the compiler.
 
@@ -679,13 +496,13 @@ defmodule List do
       123
 
   """
-  @spec to_integer(charlist) :: integer
-  def to_integer(charlist) do
-    :erlang.list_to_integer(charlist)
+  @spec to_integer(char_list) :: integer
+  def to_integer(char_list) do
+    :erlang.list_to_integer(char_list)
   end
 
   @doc """
-  Returns an integer whose text representation is `charlist` in base `base`.
+  Returns an integer whose text representation is `char_list` in base `base`.
 
   Inlined by the compiler.
 
@@ -695,9 +512,9 @@ defmodule List do
       1023
 
   """
-  @spec to_integer(charlist, 2..36) :: integer
-  def to_integer(charlist, base) do
-    :erlang.list_to_integer(charlist, base)
+  @spec to_integer(char_list, 2..36) :: integer
+  def to_integer(char_list, base) do
+    :erlang.list_to_integer(char_list, base)
   end
 
   @doc """
@@ -720,9 +537,9 @@ defmodule List do
   Converts a list of integers representing codepoints, lists or
   strings into a string.
 
-  Notice that this function expects a list of integers representing
+  Notice that this function expect a list of integer representing
   UTF-8 codepoints. If you have a list of bytes, you must instead use
-  the [`:binary` module](http://www.erlang.org/doc/man/binary.html).
+  [the `:binary` module](http://erlang.org/doc/man/binary.html).
 
   ## Examples
 
@@ -735,24 +552,7 @@ defmodule List do
   """
   @spec to_string(:unicode.charlist) :: String.t
   def to_string(list) when is_list(list) do
-    try do
-      :unicode.characters_to_binary(list)
-    rescue
-      ArgumentError ->
-        raise ArgumentError, """
-        cannot convert the given list to a string.
-
-        To be converted to a string, a list must contain only:
-
-          * strings
-          * integers representing Unicode codepoints
-          * or a list containing one of these three elements
-
-        Please check the given list or call inspect/1 to get the list representation, got:
-
-        #{inspect list}
-        """
-    else
+    case :unicode.characters_to_binary(list) do
       result when is_binary(result) ->
         result
 
@@ -764,109 +564,6 @@ defmodule List do
     end
   end
 
-  @doc """
-  Returns a keyword list that represents an *edit script*.
-
-  The algorithm is outlined in the
-  "An O(ND) Difference Algorithm and Its Variations" paper by E. Myers.
-
-  An *edit script* is a keyword list. Each key describes the "editing action" to
-  take in order to bring `list1` closer to being equal to `list2`; a key can be
-  `:eq`, `:ins`, or `:del`. Each value is a sublist of either `list1` or `list2`
-  that should be inserted (if the corresponding key `:ins`), deleted (if the
-  corresponding key is `:del`), or left alone (if the corresponding key is
-  `:eq`) in `list1` in order to be closer to `list2`.
-
-  ## Examples
-
-      iex> List.myers_difference([1, 4, 2, 3], [1, 2, 3, 4])
-      [eq: [1], del: [4], eq: [2, 3], ins: [4]]
-
-  """
-  @spec myers_difference(list, list) :: [{:eq | :ins | :del, list}] | nil
-  def myers_difference(list1, list2) when is_list(list1) and is_list(list2) do
-    path = {0, 0, list1, list2, []}
-    find_script(0, length(list1) + length(list2), [path])
-  end
-
-  defp find_script(envelope, max, _paths) when envelope > max do
-    nil
-  end
-
-  defp find_script(envelope, max, paths) do
-    case each_diagonal(-envelope, envelope, paths, []) do
-      {:done, edits} -> compact_reverse(edits, [])
-      {:next, paths} -> find_script(envelope + 1, max, paths)
-    end
-  end
-
-  defp compact_reverse([], acc), do: acc
-
-  defp compact_reverse([{kind, elem} | rest], [{kind, result} | acc]) do
-    compact_reverse(rest, [{kind, [elem | result]} | acc])
-  end
-
-  defp compact_reverse([{kind, elem} | rest], acc) do
-    compact_reverse(rest, [{kind, [elem]} | acc])
-  end
-
-  defp each_diagonal(diag, limit, _paths, next_paths) when diag > limit do
-    {:next, Enum.reverse(next_paths)}
-  end
-
-  defp each_diagonal(diag, limit, paths, next_paths) do
-    {path, rest} = proceed_path(diag, limit, paths)
-    with {:cont, path} <- follow_snake(path) do
-      each_diagonal(diag + 2, limit, rest, [path | next_paths])
-    end
-  end
-
-  defp proceed_path(0, 0, [path]), do: {path, []}
-
-  defp proceed_path(diag, limit, [path | _] = paths) when diag == -limit do
-    {move_down(path), paths}
-  end
-
-  defp proceed_path(diag, limit, [path]) when diag == limit do
-    {move_right(path), []}
-  end
-
-  defp proceed_path(_diag, _limit, [path1, path2 | rest]) do
-    if elem(path1, 1) > elem(path2, 1) do
-      {move_right(path1), [path2 | rest]}
-    else
-      {move_down(path2), [path2 | rest]}
-    end
-  end
-
-  defp move_right({x, y, list1, [elem | rest], edits}) do
-    {x + 1, y, list1, rest, [{:ins, elem} | edits]}
-  end
-
-  defp move_right({x, y, list1, [], edits}) do
-    {x + 1, y, list1, [], edits}
-  end
-
-  defp move_down({x, y, [elem | rest], list2, edits}) do
-    {x, y + 1, rest, list2, [{:del, elem} | edits]}
-  end
-
-  defp move_down({x, y, [], list2, edits}) do
-    {x, y + 1, [], list2, edits}
-  end
-
-  defp follow_snake({x, y, [elem | rest1], [elem | rest2], edits}) do
-    follow_snake({x + 1, y + 1, rest1, rest2, [{:eq, elem} | edits]})
-  end
-
-  defp follow_snake({_x, _y, [], [], edits}) do
-    {:done, edits}
-  end
-
-  defp follow_snake(path) do
-    {:cont, path}
-  end
-
   ## Helpers
 
   # replace_at
@@ -879,72 +576,73 @@ defmodule List do
     list
   end
 
-  defp do_replace_at([_old | rest], 0, value) do
-    [value | rest]
+  defp do_replace_at([_old|rest], 0, value) do
+    [ value | rest ]
   end
 
-  defp do_replace_at([head | tail], index, value) do
-    [head | do_replace_at(tail, index - 1, value)]
+  defp do_replace_at([h|t], index, value) do
+    [ h | do_replace_at(t, index - 1, value) ]
   end
 
   # insert_at
 
   defp do_insert_at([], _index, value) do
-    [value]
+    [ value ]
   end
 
   defp do_insert_at(list, index, value) when index <= 0 do
-    [value | list]
+    [ value | list ]
   end
 
-  defp do_insert_at([head | tail], index, value) do
-    [head | do_insert_at(tail, index - 1, value)]
+  defp do_insert_at([h|t], index, value) do
+    [ h | do_insert_at(t, index - 1, value) ]
   end
 
   # update_at
 
-  defp do_update_at([value | list], 0, fun) do
-    [fun.(value) | list]
+  defp do_update_at([value|list], 0, fun) do
+    [ fun.(value) | list ]
   end
 
   defp do_update_at(list, index, _fun) when index < 0 do
     list
   end
 
-  defp do_update_at([head | tail], index, fun) do
-    [head | do_update_at(tail, index - 1, fun)]
+  defp do_update_at([h|t], index, fun) do
+    [ h | do_update_at(t, index - 1, fun) ]
   end
 
   defp do_update_at([], _index, _fun) do
     []
   end
 
-  # pop_at
+  # delete_at
 
-  defp do_pop_at([], _index, default, acc) do
-    {default, :lists.reverse(acc)}
+  defp do_delete_at([], _index) do
+    []
   end
 
-  defp do_pop_at(list, index, default, []) when index < 0 do
-    {default, list}
+  defp do_delete_at([_|t], 0) do
+    t
   end
 
-  defp do_pop_at([head | tail], 0, _default, acc) do
-    {head, :lists.reverse(acc, tail)}
+  defp do_delete_at(list, index) when index < 0 do
+    list
   end
 
-  defp do_pop_at([head | tail], index, default, acc) do
-    do_pop_at(tail, index - 1, default, [head | acc])
+  defp do_delete_at([h|t], index) do
+    [h | do_delete_at(t, index-1)]
   end
 
   # zip
 
   defp do_zip(list, acc) do
     converter = fn x, acc -> do_zip_each(to_list(x), acc) end
-    case :lists.mapfoldl(converter, [], list) do
-      {_, nil} -> :lists.reverse(acc)
-      {mlist, heads} ->
-        do_zip(mlist, [to_tuple(:lists.reverse(heads)) | acc])
+    {mlist, heads} = :lists.mapfoldl converter, [], list
+
+    case heads do
+      nil -> :lists.reverse acc
+      _   -> do_zip mlist, [:erlang.list_to_tuple(:lists.reverse(heads))|acc]
     end
   end
 
@@ -952,8 +650,8 @@ defmodule List do
     {nil, nil}
   end
 
-  defp do_zip_each([head | tail], acc) do
-    {tail, [head | acc]}
+  defp do_zip_each([h|t], acc) do
+    {t, [h|acc]}
   end
 
   defp do_zip_each([], _) do

lib/elixir/lib/list/chars.ex

@@ -1,62 +1,56 @@
 defprotocol List.Chars do
   @moduledoc ~S"""
-  The `List.Chars` protocol is responsible for
-  converting a structure to a charlist (only if applicable).
-
+  The List.Chars protocol is responsible for
+  converting a structure to a list (only if applicable).
   The only function required to be implemented is
-  `to_charlist/1` which does the conversion.
+  `to_char_list` which does the conversion.
 
-  The `to_charlist/1` function automatically imported
-  by `Kernel` invokes this protocol.
+  The `to_char_list` function automatically imported
+  by Kernel invokes this protocol.
   """
 
-  @doc """
-  Converts `term` to a charlist.
-  """
-  @spec to_charlist(t) :: charlist
-  def to_charlist(term)
-
-  @doc false
-  # TODO: Remove by 2.0
-  # (hard-deprecated in elixir_dispatch)
-  Kernel.def to_char_list(term) do
-    __MODULE__.to_charlist(term)
-  end
+  def to_char_list(thing)
 end
 
 defimpl List.Chars, for: Atom do
-  def to_charlist(atom), do: Atom.to_charlist(atom)
+  def to_char_list(atom), do: Atom.to_char_list(atom)
 end
 
 defimpl List.Chars, for: BitString do
   @doc """
-  Returns the given binary `term` converted to a charlist.
+  Returns the given binary converted to a char list.
   """
-  def to_charlist(term) when is_binary(term) do
-    String.to_charlist(term)
+  def to_char_list(thing) when is_binary(thing) do
+    String.to_char_list(thing)
   end
 
-  def to_charlist(term) do
+  def to_char_list(thing) do
     raise Protocol.UndefinedError,
              protocol: @protocol,
-                value: term,
-          description: "cannot convert a bitstring to a charlist"
+                value: thing,
+          description: "cannot convert a bitstring to a char list"
   end
 end
 
 defimpl List.Chars, for: List do
-  # Note that same inlining is used for the rewrite rule.
-  def to_charlist(list), do: list
+  def to_char_list(list), do: list
 end
 
 defimpl List.Chars, for: Integer do
-  def to_charlist(term) do
-    Integer.to_charlist(term)
+  def to_char_list(thing) do
+    Integer.to_char_list(thing)
   end
 end
 
 defimpl List.Chars, for: Float do
-  def to_charlist(term) do
-    :io_lib_format.fwrite_g(term)
+  @digits 20
+  @limit  :math.pow(10, @digits)
+
+  def to_char_list(thing) when thing > @limit do
+    Float.to_char_list(thing, scientific: @digits)
+  end
+
+  def to_char_list(thing) do
+    Float.to_char_list(thing, compact: true, decimals: @digits)
   end
 end

lib/elixir/lib/macro/env.ex

@@ -3,8 +3,8 @@ defmodule Macro.Env do
   A struct that holds compile time environment information.
 
   The current environment can be accessed at any time as
-  `__ENV__/0`. Inside macros, the caller environment can be
-  accessed as `__CALLER__/0`.
+  `__ENV__`. Inside macros, the caller environment can be
+  accessed as `__CALLER__`.
 
   An instance of `Macro.Env` must not be modified by hand. If you need to
   create a custom environment to pass to `Code.eval_quoted/3`, use the
@@ -24,32 +24,24 @@ defmodule Macro.Env do
     * `module` - the current module name
     * `file` - the current file name as a binary
     * `line` - the current line as an integer
-    * `function` - a tuple as `{atom, integer}`, where the first
-      element is the function name and the second its arity; returns
+    * `function` - a tuple as `{atom, integer`}, where the first
+      element is the function name and the seconds its arity; returns
       `nil` if not inside a function
     * `context` - the context of the environment; it can be `nil`
-      (default context), inside a guard or inside a match
-    * `aliases` -  a list of two-element tuples, where the first
-      element is the aliased name and the second one the actual name
+      (default context), inside a guard or inside an assign
+    * `aliases` -  a list of two item tuples, where the first
+      item is the aliased name and the second the actual name
     * `requires` - the list of required modules
     * `functions` - a list of functions imported from each module
     * `macros` - a list of macros imported from each module
     * `macro_aliases` - a list of aliases defined inside the current macro
     * `context_modules` - a list of modules defined in the current context
-    * `lexical_tracker` - PID of the lexical tracker which is responsible for
-      keeping user info
     * `vars` - a list keeping all defined variables as `{var, context}`
-
-  The following fields are private and must not be accessed or relied on:
-
     * `export_vars` - a list keeping all variables to be exported in a
       construct (may be `nil`)
-    * `match_vars` - controls how "new" variables are handled. Inside a
-      match it is a list with all variables in a match. Outside of a match
-      is either `:warn` or `:apply`
-    * `prematch_vars` - a list of variables defined before a match (is
-      `nil` when not inside a match)
-
+    * `lexical_tracker` - PID of the lexical tracker which is responsible to
+      keep user info
+    * `local` - the module to expand local functions to
   """
 
   @type name_arity :: {atom, arity}
@@ -63,13 +55,10 @@ defmodule Macro.Env do
   @type macros :: [{module, [name_arity]}]
   @type context_modules :: [module]
   @type vars :: [{atom, atom | non_neg_integer}]
-  @type lexical_tracker :: pid | nil
+  @type export_vars :: vars | nil
+  @type lexical_tracker :: pid
   @type local :: atom | nil
 
-  @opaque export_vars :: vars | nil
-  @opaque match_vars :: vars | :warn | :apply
-  @opaque prematch_vars :: vars | nil
-
   @type t :: %{__struct__: __MODULE__,
                module: atom,
                file: file,
@@ -84,9 +73,8 @@ defmodule Macro.Env do
                context_modules: context_modules,
                vars: vars,
                export_vars: export_vars,
-               match_vars: match_vars,
-               prematch_vars: prematch_vars,
-               lexical_tracker: lexical_tracker}
+               lexical_tracker: lexical_tracker,
+               local: local}
 
   def __struct__ do
     %{__struct__: __MODULE__,
@@ -102,22 +90,15 @@ defmodule Macro.Env do
       macro_aliases: [],
       context_modules: [],
       vars: [],
-      lexical_tracker: nil,
       export_vars: nil,
-      match_vars: :warn,
-      prematch_vars: nil}
-  end
-
-  def __struct__(kv) do
-    Enum.reduce kv, __struct__(), fn {k, v}, acc -> :maps.update(k, v, acc) end
+      lexical_tracker: nil,
+      local: nil}
   end
 
   @doc """
   Returns a keyword list containing the file and line
   information as keys.
   """
-  @spec location(t) :: keyword
-  def location(env)
   def location(%{__struct__: Macro.Env, file: file, line: line}) do
     [file: file, line: line]
   end
@@ -126,22 +107,17 @@ defmodule Macro.Env do
   Returns whether the compilation environment is currently
   inside a guard.
   """
-  @spec in_guard?(t) :: boolean
-  def in_guard?(env)
   def in_guard?(%{__struct__: Macro.Env, context: context}), do: context == :guard
 
   @doc """
   Returns whether the compilation environment is currently
   inside a match clause.
   """
-  @spec in_match?(t) :: boolean
-  def in_match?(env)
   def in_match?(%{__struct__: Macro.Env, context: context}), do: context == :match
 
   @doc """
   Returns the environment stacktrace.
   """
-  @spec stacktrace(t) :: list
   def stacktrace(%{__struct__: Macro.Env} = env) do
     cond do
       is_nil(env.module) ->

lib/elixir/lib/map.ex

@@ -1,822 +1,48 @@
 defmodule Map do
   @moduledoc """
-  A set of functions for working with maps.
+  A Dict implementation that works on maps.
 
-  Maps are the "go to" key-value data structure in Elixir. Maps can be created
-  with the `%{}` syntax, and key-value pairs can be expressed as `key => value`:
+  Maps are key-value stores where keys are compared using
+  the match operator (`===`). Maps can be created with
+  the `%{}` special form defined in the `Kernel.SpecialForms`
+  module.
 
-      iex> %{}
-      %{}
-      iex> %{"one" => :two, 3 => "four"}
-      %{3 => "four", "one" => :two}
-
-  Key-value pairs in a map do not follow any order (that's why the printed map
-  in the example above has a different order than the map that was created).
-
-  Maps do not impose any restriction on the key type: anything can be a key in a
-  map. As a key-value structure, maps do not allow duplicated keys. Keys are
-  compared using the exact-equality operator (`===`). If colliding keys are defined
-  in a map literal, the last one prevails.
-
-  When the key in a key-value pair is an atom, the `key: value` shorthand syntax
-  can be used (as in many other special forms), provided key-value pairs are put at
-  the end:
-
-      iex> %{"hello" => "world", a: 1, b: 2}
-      %{:a => 1, :b => 2, "hello" => "world"}
-
-  Keys in maps can be accessed through some of the functions in this module
-  (such as `Map.get/3` or `Map.fetch/2`) or through the `[]` syntax provided by
-  the `Access` module:
-
-      iex> map = %{a: 1, b: 2}
-      iex> Map.fetch(map, :a)
-      {:ok, 1}
-      iex> map[:b]
-      2
-      iex> map["non_existing_key"]
-      nil
-
-  The alternative access syntax `map.key` is provided alongside `[]` when the
-  map has a `:key` key; note that while `map[key]` will return `nil` if `map`
-  doesn't contain `key`, `map.key` will raise if `map` doesn't contain
-  the key `:key`.
-
-      iex> map = %{foo: "bar", baz: "bong"}
-      iex> map.foo
-      "bar"
-      iex> map.non_existing_key
-      ** (KeyError) key :non_existing_key not found in: %{baz: "bong", foo: "bar"}
-
-  Maps can be pattern matched on; when a map is on the left-hand side of a
-  pattern match, it will match if the map on the right-hand side contains the
-  keys on the left-hand side and their values match the ones on the left-hand
-  side. This means that an empty map matches every map.
-
-      iex> %{} = %{foo: "bar"}
-      %{foo: "bar"}
-      iex> %{a: a} = %{:a => 1, "b" => 2, [:c, :e, :e] => 3}
-      iex> a
-      1
-      iex> %{:c => 3} = %{:a => 1, 2 => :b}
-      ** (MatchError) no match of right hand side value: %{2 => :b, :a => 1}
-
-  Variables can be used as map keys both when writing map literals as well as
-  when matching:
-
-      iex> n = 1
-      1
-      iex> %{n => :one}
-      %{1 => :one}
-      iex> %{^n => :one} = %{1 => :one, 2 => :two, 3 => :three}
-      %{1 => :one, 2 => :two, 3 => :three}
-
-  Maps also support a specific update syntax to update the value stored under
-  *existing* atom keys:
-
-      iex> map = %{one: 1, two: 2}
-      iex> %{map | one: "one"}
-      %{one: "one", two: 2}
-      iex> %{map | three: 3}
-      ** (KeyError) key :three not found
-
-  ## Modules to work with maps
-
-  This module aims to provide functions that perform operations specific to maps
-  (like accessing keys, updating values, and so on). For traversing maps as
-  collections, developers should use the `Enum` module that works across a
-  variety of data types.
-
-  The `Kernel` module also provides a few functions to work with maps: for
-  example, `Kernel.map_size/1` to know the number of key-value pairs in a map or
-  `Kernel.is_map/1` to know if a term is a map.
+  For more information about the functions in this module and
+  their APIs, please consult the `Dict` module.
   """
 
-  @type key :: any
-  @type value :: any
-  @compile {:inline, fetch: 2, fetch!: 2, get: 2, put: 3, delete: 2, has_key?: 2, replace!: 3}
+  use Dict
 
-  @doc """
-  Returns all keys from `map`.
+  defdelegate [keys(map), values(map), size(map), merge(map1, map2), to_list(map)], to: :maps
 
-  ## Examples
-
-      iex> Map.keys(%{a: 1, b: 2})
-      [:a, :b]
-
-  """
-  @spec keys(map) :: [key]
-  defdelegate keys(map), to: :maps
-
-  @doc """
-  Returns all values from `map`.
-
-  ## Examples
-
-      iex> Map.values(%{a: 1, b: 2})
-      [1, 2]
-
-  """
-  @spec values(map) :: [value]
-  defdelegate values(map), to: :maps
-
-  @doc """
-  Converts `map` to a list.
-
-  Each key-value pair in the map is converted to a two-element tuple `{key,
-  value}` in the resulting list.
-
-  ## Examples
-
-      iex> Map.to_list(%{a: 1})
-      [a: 1]
-      iex> Map.to_list(%{1 => 2})
-      [{1, 2}]
-
-  """
-  @spec to_list(map) :: [{term, term}]
-  defdelegate to_list(map), to: :maps
+  @compile {:inline, fetch: 2, put: 3, delete: 2, has_key?: 2}
 
   @doc """
   Returns a new empty map.
-
-  ## Examples
-
-      iex> Map.new
-      %{}
-
   """
-  @spec new :: map
   def new, do: %{}
 
-  @doc """
-  Creates a map from an `enumerable`.
-
-  Duplicated keys are removed; the latest one prevails.
-
-  ## Examples
-
-      iex> Map.new([{:b, 1}, {:a, 2}])
-      %{a: 2, b: 1}
-      iex> Map.new([a: 1, a: 2, a: 3])
-      %{a: 3}
-
-  """
-  @spec new(Enumerable.t) :: map
-  def new(enumerable)
-  def new(list) when is_list(list), do: :maps.from_list(list)
-  def new(%{__struct__: _} = struct), do: new_from_enum(struct)
-  def new(%{} = map), do: map
-  def new(enum), do: new_from_enum(enum)
-
-  defp new_from_enum(enumerable) do
-    enumerable
-    |> Enum.to_list
-    |> :maps.from_list
-  end
-
-  @doc """
-  Creates a map from an `enumerable` via the given transformation function.
-
-  Duplicated keys are removed; the latest one prevails.
-
-  ## Examples
-
-      iex> Map.new([:a, :b], fn x -> {x, x} end)
-      %{a: :a, b: :b}
-
-  """
-  @spec new(Enumerable.t, (term -> {key, value})) :: map
-  def new(enumerable, transform) when is_function(transform, 1) do
-    enumerable
-    |> Enum.to_list
-    |> new_transform(transform, [])
-  end
-
-  defp new_transform([], _fun, acc) do
-    acc
-    |> :lists.reverse
-    |> :maps.from_list
-  end
-
-  defp new_transform([item | rest], fun, acc) do
-    new_transform(rest, fun, [fun.(item) | acc])
-  end
-
-  @doc """
-  Returns whether the given `key` exists in the given `map`.
-
-  ## Examples
-
-      iex> Map.has_key?(%{a: 1}, :a)
-      true
-      iex> Map.has_key?(%{a: 1}, :b)
-      false
-
-  Inlined by the compiler.
-  """
-  @spec has_key?(map, key) :: boolean
   def has_key?(map, key), do: :maps.is_key(key, map)
 
-  @doc """
-  Fetches the value for a specific `key` in the given `map`.
-
-  If `map` contains the given `key` with value `value`, then `{:ok, value}` is
-  returned. If `map` doesn't contain `key`, `:error` is returned.
-
-  ## Examples
-
-      iex> Map.fetch(%{a: 1}, :a)
-      {:ok, 1}
-      iex> Map.fetch(%{a: 1}, :b)
-      :error
-
-  Inlined by the compiler.
-  """
-  @spec fetch(map, key) :: {:ok, value} | :error
   def fetch(map, key), do: :maps.find(key, map)
 
-  @doc """
-  Fetches the value for a specific `key` in the given `map`, erroring out if
-  `map` doesn't contain `key`.
-
-  If `map` contains the given `key`, the corresponding value is returned. If
-  `map` doesn't contain `key`, a `KeyError` exception is raised.
-
-  ## Examples
-
-      iex> Map.fetch!(%{a: 1}, :a)
-      1
-      iex> Map.fetch!(%{a: 1}, :b)
-      ** (KeyError) key :b not found in: %{a: 1}
-
-  """
-  @spec fetch!(map, key) :: value | no_return
-  def fetch!(map, key) do
-    :maps.get(key, map)
+  def put(map, key, val) do
+    :maps.put(key, val, map)
   end
 
-  @doc """
-  Puts the given `value` under `key` unless the entry `key`
-  already exists in `map`.
-
-  ## Examples
-
-      iex> Map.put_new(%{a: 1}, :b, 2)
-      %{a: 1, b: 2}
-      iex> Map.put_new(%{a: 1, b: 2}, :a, 3)
-      %{a: 1, b: 2}
-
-  """
-  @spec put_new(map, key, value) :: map
-  def put_new(map, key, value) do
-    case map do
-      %{^key => _value} ->
-        map
-      %{} ->
-        put(map, key, value)
-      other ->
-        :erlang.error({:badmap, other})
-    end
-  end
-
-  @doc """
-  Alters the value stored under `key` to `value`, but only
-  if the entry `key` already exists in `map`.
-
-  ## Examples
-
-      iex> Map.replace(%{a: 1}, :b, 2)
-      %{a: 1}
-      iex> Map.replace(%{a: 1, b: 2}, :a, 3)
-      %{a: 3, b: 2}
-
-  """
-  @spec replace(map, key, value) :: map
-  def replace(map, key, value) do
-    case map do
-      %{^key => _value} ->
-        put(map, key, value)
-      %{} ->
-        map
-      other ->
-        :erlang.error({:badmap, other})
-    end
-  end
-
-  @doc """
-  Similar to `replace/3`, but will raise a `KeyError`
-  if the key does not exist in the map.
-
-  ## Examples
-
-      iex> Map.replace!(%{a: 1, b: 2}, :a, 3)
-      %{a: 3, b: 2}
-      iex> Map.replace!(%{a: 1}, :b, 2)
-      ** (KeyError) key :b not found in: %{a: 1}
-
-  Inlined by the compiler.
-  """
-  @spec replace!(map, key, value) :: map
-  def replace!(map, key, value) do
-    :maps.update(key, value, map)
-  end
-
-  @doc """
-  Evaluates `fun` and puts the result under `key`
-  in `map` unless `key` is already present.
-
-  This function is useful in case you want to compute the value to put under
-  `key` only if `key` is not already present (e.g., the value is expensive to
-  calculate or generally difficult to setup and teardown again).
-
-  ## Examples
-
-      iex> map = %{a: 1}
-      iex> fun = fn ->
-      ...>   # some expensive operation here
-      ...>   3
-      ...> end
-      iex> Map.put_new_lazy(map, :a, fun)
-      %{a: 1}
-      iex> Map.put_new_lazy(map, :b, fun)
-      %{a: 1, b: 3}
-
-  """
-  @spec put_new_lazy(map, key, (() -> value)) :: map
-  def put_new_lazy(map, key, fun) when is_function(fun, 0) do
-    case map do
-      %{^key => _value} ->
-        map
-      %{} ->
-        put(map, key, fun.())
-      other ->
-        :erlang.error({:badmap, other})
-    end
-  end
-
-  @doc """
-  Returns a new map with all the key-value pairs in `map` where the key
-  is in `keys`.
-
-  If `keys` contains keys that are not in `map`, they're simply ignored.
-
-  ## Examples
-
-      iex> Map.take(%{a: 1, b: 2, c: 3}, [:a, :c, :e])
-      %{a: 1, c: 3}
-
-  """
-  @spec take(map, Enumerable.t) :: map
-  def take(map, keys)
-
-  def take(map, keys) when is_map(map) do
-    keys
-    |> Enum.to_list
-    |> take(map, [])
-  end
-
-  def take(non_map, _keys) do
-    :erlang.error({:badmap, non_map})
-  end
-
-  defp take([], _map, acc) do
-    :maps.from_list(acc)
-  end
-
-  defp take([key | rest], map, acc) do
-    acc =
-      case map do
-        %{^key => value} -> [{key, value} | acc]
-        %{} -> acc
-      end
-
-    take(rest, map, acc)
-  end
-
-  @doc """
-  Gets the value for a specific `key` in `map`.
-
-  If `key` is present in `map` with value `value`, then `value` is
-  returned. Otherwise, `default` is returned (which is `nil` unless
-  specified otherwise).
-
-  ## Examples
-
-      iex> Map.get(%{}, :a)
-      nil
-      iex> Map.get(%{a: 1}, :a)
-      1
-      iex> Map.get(%{a: 1}, :b)
-      nil
-      iex> Map.get(%{a: 1}, :b, 3)
-      3
-
-  """
-  @spec get(map, key, value) :: value
-  def get(map, key, default \\ nil) do
-    case map do
-      %{^key => value} ->
-        value
-      %{} ->
-        default
-      other ->
-        :erlang.error({:badmap, other}, [map, key, default])
-    end
-  end
-
-  @doc """
-  Gets the value for a specific `key` in `map`.
-
-  If `key` is present in `map` with value `value`, then `value` is
-  returned. Otherwise, `fun` is evaluated and its result is returned.
-
-  This is useful if the default value is very expensive to calculate or
-  generally difficult to setup and teardown again.
-
-  ## Examples
-
-      iex> map = %{a: 1}
-      iex> fun = fn ->
-      ...>   # some expensive operation here
-      ...>   13
-      ...> end
-      iex> Map.get_lazy(map, :a, fun)
-      1
-      iex> Map.get_lazy(map, :b, fun)
-      13
-
-  """
-  @spec get_lazy(map, key, (() -> value)) :: value
-  def get_lazy(map, key, fun) when is_function(fun, 0) do
-    case map do
-      %{^key => value} ->
-        value
-      %{} ->
-        fun.()
-      other ->
-        :erlang.error({:badmap, other}, [map, key, fun])
-    end
-  end
-
-  @doc """
-  Puts the given `value` under `key` in `map`.
-
-  ## Examples
-
-      iex> Map.put(%{a: 1}, :b, 2)
-      %{a: 1, b: 2}
-      iex> Map.put(%{a: 1, b: 2}, :a, 3)
-      %{a: 3, b: 2}
-
-  Inlined by the compiler.
-  """
-  @spec put(map, key, value) :: map
-  def put(map, key, value) do
-    :maps.put(key, value, map)
-  end
-
-  @doc """
-  Deletes the entry in `map` for a specific `key`.
-
-  If the `key` does not exist, returns `map` unchanged.
-
-  ## Examples
-
-      iex> Map.delete(%{a: 1, b: 2}, :a)
-      %{b: 2}
-      iex> Map.delete(%{b: 2}, :a)
-      %{b: 2}
-
-  Inlined by the compiler.
-  """
-  @spec delete(map, key) :: map
   def delete(map, key), do: :maps.remove(key, map)
 
-  @doc """
-  Merges two maps into one.
-
-  All keys in `map2` will be added to `map1`, overriding any existing one
-  (i.e., the keys in `map2` "have precedence" over the ones in `map1`).
-
-  If you have a struct and you would like to merge a set of keys into the
-  struct, do not use this function, as it would merge all keys on the right
-  side into the struct, even if the key is not part of the struct. Instead,
-  use `Kernel.struct/2`.
-
-  ## Examples
-
-      iex> Map.merge(%{a: 1, b: 2}, %{a: 3, d: 4})
-      %{a: 3, b: 2, d: 4}
-
-  """
-  @spec merge(map, map) :: map
-  defdelegate merge(map1, map2), to: :maps
-
-  @doc """
-  Merges two maps into one, resolving conflicts through the given `callback`.
-
-  All keys in `map2` will be added to `map1`. The given function will be invoked
-  when there are duplicate keys; its arguments are `key` (the duplicate key),
-  `value1` (the value of `key` in `map1`), and `value2` (the value of `key` in
-  `map2`). The value returned by `callback` is used as the value under `key` in
-  the resulting map.
-
-  ## Examples
-
-      iex> Map.merge(%{a: 1, b: 2}, %{a: 3, d: 4}, fn _k, v1, v2 ->
-      ...>   v1 + v2
-      ...> end)
-      %{a: 4, b: 2, d: 4}
-
-  """
-  @spec merge(map, map, (key, value, value -> value)) :: map
-  def merge(map1, map2, callback) when is_function(callback, 3) do
-    if map_size(map1) > map_size(map2) do
-      :maps.fold fn key, val2, acc ->
-        update(acc, key, val2, fn val1 -> callback.(key, val1, val2) end)
-      end, map1, map2
-    else
-      :maps.fold fn key, val2, acc ->
-        update(acc, key, val2, fn val1 -> callback.(key, val2, val1) end)
-      end, map2, map1
-    end
+  def merge(map1, map2, callback) do
+    :maps.fold fn k, v2, acc ->
+      update(acc, k, v2, fn(v1) -> callback.(k, v1, v2) end)
+    end, map1, map2
   end
 
   @doc """
-  Updates the `key` in `map` with the given function.
-
-  If `key` is present in `map` with value `value`, `fun` is invoked with
-  argument `value` and its result is used as the new value of `key`. If `key` is
-  not present in `map`, `initial` is inserted as the value of `key`. The initial
-  value will not be passed through the update function.
-
-  ## Examples
-
-      iex> Map.update(%{a: 1}, :a, 13, &(&1 * 2))
-      %{a: 2}
-      iex> Map.update(%{a: 1}, :b, 11, &(&1 * 2))
-      %{a: 1, b: 11}
-
-  """
-  @spec update(map, key, value, (value -> value)) :: map
-  def update(map, key, initial, fun) when is_function(fun, 1) do
-    case map do
-      %{^key => value} ->
-        put(map, key, fun.(value))
-      %{} ->
-        put(map, key, initial)
-      other ->
-        :erlang.error({:badmap, other}, [map, key, initial, fun])
-    end
-  end
-
-  @doc """
-  Returns and removes the value associated with `key` in `map`.
-
-  If `key` is present in `map` with value `value`, `{value, new_map}` is
-  returned where `new_map` is the result of removing `key` from `map`. If `key`
-  is not present in `map`, `{default, map}` is returned.
-
-  ## Examples
-
-      iex> Map.pop(%{a: 1}, :a)
-      {1, %{}}
-      iex> Map.pop(%{a: 1}, :b)
-      {nil, %{a: 1}}
-      iex> Map.pop(%{a: 1}, :b, 3)
-      {3, %{a: 1}}
-
-  """
-  @spec pop(map, key, value) :: {value, map}
-  def pop(map, key, default \\ nil) do
-    case map do
-      %{^key => value} ->
-        {value, delete(map, key)}
-      %{} ->
-        {default, map}
-      other ->
-        :erlang.error({:badmap, other}, [map, key, default])
-    end
-  end
-
-  @doc """
-  Lazily returns and removes the value associated with `key` in `map`.
-
-  If `key` is present in `map` with value `value`, `{value, new_map}` is
-  returned where `new_map` is the result of removing `key` from `map`. If `key`
-  is not present in `map`, `{fun_result, map}` is returned, where `fun_result`
-  is the result of applying `fun`.
-
-  This is useful if the default value is very expensive to calculate or
-  generally difficult to setup and teardown again.
-
-  ## Examples
-
-      iex> map = %{a: 1}
-      iex> fun = fn ->
-      ...>   # some expensive operation here
-      ...>   13
-      ...> end
-      iex> Map.pop_lazy(map, :a, fun)
-      {1, %{}}
-      iex> Map.pop_lazy(map, :b, fun)
-      {13, %{a: 1}}
-
-  """
-  @spec pop_lazy(map, key, (() -> value)) :: {value, map}
-  def pop_lazy(map, key, fun) when is_function(fun, 0) do
-    case map do
-      %{^key => value} ->
-        {value, delete(map, key)}
-      %{} ->
-        {fun.(), map}
-      other ->
-        :erlang.error({:badmap, other}, [map, key, fun])
-    end
-  end
-
-  @doc """
-  Drops the given `keys` from `map`.
-
-  If `keys` contains keys that are not in `map`, they're simply ignored.
-
-  ## Examples
-
-      iex> Map.drop(%{a: 1, b: 2, c: 3}, [:b, :d])
-      %{a: 1, c: 3}
-
-  """
-  @spec drop(map, Enumerable.t) :: map
-  def drop(map, keys)
-
-  def drop(map, keys) when is_map(map) do
-    keys
-    |> Enum.to_list
-    |> drop_list(map)
-  end
-
-  def drop(non_map, keys) do
-    :erlang.error({:badmap, non_map}, [non_map, keys])
-  end
-
-  defp drop_list([], acc), do: acc
-  defp drop_list([key | rest], acc) do
-    drop_list(rest, delete(acc, key))
-  end
-
-  @doc """
-  Takes all entries corresponding to the given `keys` in `map` and extracts
-  them into a separate map.
-
-  Returns a tuple with the new map and the old map with removed keys.
-
-  Keys for which there are no entries in `map` are ignored.
-
-  ## Examples
-
-      iex> Map.split(%{a: 1, b: 2, c: 3}, [:a, :c, :e])
-      {%{a: 1, c: 3}, %{b: 2}}
-
-  """
-  @spec split(map, Enumerable.t) :: {map, map}
-  def split(map, keys)
-
-  def split(map, keys) when is_map(map) do
-    keys
-    |> Enum.to_list
-    |> split([], map)
-  end
-
-  def split(non_map, keys) do
-    :erlang.error({:badmap, non_map}, [non_map, keys])
-  end
-
-  defp split([], included, excluded) do
-    {:maps.from_list(included), excluded}
-  end
-
-  defp split([key | rest], included, excluded) do
-    case excluded do
-      %{^key => value} ->
-        split(rest, [{key, value} | included], delete(excluded, key))
-      _other ->
-        split(rest, included, excluded)
-    end
-  end
-
-  @doc """
-  Updates `key` with the given function.
-
-  If `key` is present in `map` with value `value`, `fun` is invoked with
-  argument `value` and its result is used as the new value of `key`. If `key` is
-  not present in `map`, a `KeyError` exception is raised.
-
-  ## Examples
-
-      iex> Map.update!(%{a: 1}, :a, &(&1 * 2))
-      %{a: 2}
-
-      iex> Map.update!(%{a: 1}, :b, &(&1 * 2))
-      ** (KeyError) key :b not found in: %{a: 1}
-
-  """
-  @spec update!(map, key, (value -> value)) :: map
-  def update!(map, key, fun) when is_function(fun, 1) do
-    value = fetch!(map, key)
-    put(map, key, fun.(value))
-  end
-
-  @doc """
-  Gets the value from `key` and updates it, all in one pass.
-
-  `fun` is called with the current value under `key` in `map` (or `nil` if `key`
-  is not present in `map`) and must return a two-element tuple: the "get" value
-  (the retrieved value, which can be operated on before being returned) and the
-  new value to be stored under `key` in the resulting new map. `fun` may also
-  return `:pop`, which means the current value shall be removed from `map` and
-  returned (making this function behave like `Map.pop(map, key)`.
-
-  The returned value is a tuple with the "get" value returned by
-  `fun` and a new map with the updated value under `key`.
-
-  ## Examples
-
-      iex> Map.get_and_update(%{a: 1}, :a, fn current_value ->
-      ...>   {current_value, "new value!"}
-      ...> end)
-      {1, %{a: "new value!"}}
-
-      iex> Map.get_and_update(%{a: 1}, :b, fn current_value ->
-      ...>   {current_value, "new value!"}
-      ...> end)
-      {nil, %{b: "new value!", a: 1}}
-
-      iex> Map.get_and_update(%{a: 1}, :a, fn _ -> :pop end)
-      {1, %{}}
-
-      iex> Map.get_and_update(%{a: 1}, :b, fn _ -> :pop end)
-      {nil, %{a: 1}}
-
-  """
-  @spec get_and_update(map, key, (value -> {get, value} | :pop)) :: {get, map} when get: term
-  def get_and_update(map, key, fun) when is_function(fun, 1) do
-    current = get(map, key)
-
-    case fun.(current) do
-      {get, update} ->
-        {get, put(map, key, update)}
-      :pop ->
-        {current, delete(map, key)}
-      other ->
-        raise "the given function must return a two-element tuple or :pop, got: #{inspect(other)}"
-    end
-  end
-
-  @doc """
-  Gets the value from `key` and updates it. Raises if there is no `key`.
-
-  Behaves exactly like `get_and_update/3`, but raises a `KeyError` exception if
-  `key` is not present in `map`.
-
-  ## Examples
-
-      iex> Map.get_and_update!(%{a: 1}, :a, fn current_value ->
-      ...>   {current_value, "new value!"}
-      ...> end)
-      {1, %{a: "new value!"}}
-
-      iex> Map.get_and_update!(%{a: 1}, :b, fn current_value ->
-      ...>   {current_value, "new value!"}
-      ...> end)
-      ** (KeyError) key :b not found in: %{a: 1}
-
-      iex> Map.get_and_update!(%{a: 1}, :a, fn _ ->
-      ...>   :pop
-      ...> end)
-      {1, %{}}
-
-  """
-  @spec get_and_update!(map, key, (value -> {get, value})) :: {get, map} | no_return when get: term
-  def get_and_update!(map, key, fun) when is_function(fun, 1) do
-    value = fetch!(map, key)
-
-    case fun.(value) do
-      {get, update} ->
-        {get, put(map, key, update)}
-      :pop ->
-        {value, delete(map, key)}
-      other ->
-        raise "the given function must return a two-element tuple or :pop, got: #{inspect(other)}"
-    end
-  end
-
-  @doc """
-  Converts a `struct` to map.
+  Converts a struct to map.
 
   It accepts the struct module or a struct itself and
-  simply removes the `__struct__` field from the given struct
-  or from a new struct generated from the given module.
+  simply removes the `__struct__` field from the struct.
 
   ## Example
 
@@ -831,40 +57,13 @@ defmodule Map do
       #=> %{name: "john"}
 
   """
-  @spec from_struct(atom | struct) :: map
   def from_struct(struct) when is_atom(struct) do
-    delete(struct.__struct__(), :__struct__)
+    :maps.remove(:__struct__, struct.__struct__)
   end
 
-  def from_struct(%_{} = struct) do
-    delete(struct, :__struct__)
+  def from_struct(%{__struct__: _} = struct) do
+    :maps.remove(:__struct__, struct)
   end
 
-  @doc """
-  Checks if two maps are equal.
-
-  Two maps are considered to be equal if they contain
-  the same keys and those keys contain the same values.
-
-  ## Examples
-
-      iex> Map.equal?(%{a: 1, b: 2}, %{b: 2, a: 1})
-      true
-      iex> Map.equal?(%{a: 1, b: 2}, %{b: 1, a: 2})
-      false
-
-  """
-  @spec equal?(map, map) :: boolean
-  def equal?(map1, map2)
-
   def equal?(%{} = map1, %{} = map2), do: map1 === map2
-  def equal?(%{} = map1, map2), do: :erlang.error({:badmap, map2}, [map1, map2])
-  def equal?(term, other), do: :erlang.error({:badmap, term}, [term, other])
-
-  @doc false
-  # TODO: Remove on 2.0
-  # (hard-deprecated in elixir_dispatch)
-  def size(map) do
-    map_size(map)
-  end
 end

lib/elixir/lib/map_set.ex

@@ -1,385 +0,0 @@
-defmodule MapSet do
-  @moduledoc """
-  Functions that work on sets.
-
-  `MapSet` is the "go to" set data structure in Elixir. A set can be constructed
-  using `MapSet.new/0`:
-
-      iex> MapSet.new
-      #MapSet<[]>
-
-  A set can contain any kind of elements, and elements in a set don't have to be
-  of the same type. By definition, sets can't contain duplicate elements: when
-  inserting an element in a set where it's already present, the insertion is
-  simply a no-op.
-
-      iex> map_set = MapSet.new
-      iex> MapSet.put(map_set, "foo")
-      #MapSet<["foo"]>
-      iex> map_set |> MapSet.put("foo") |> MapSet.put("foo")
-      #MapSet<["foo"]>
-
-  A `MapSet` is represented internally using the `%MapSet{}` struct. This struct
-  can be used whenever there's a need to pattern match on something being a `MapSet`:
-
-      iex> match?(%MapSet{}, MapSet.new())
-      true
-
-  Note that, however, the struct fields are private and must not be accessed
-  directly; use the functions in this module to perform operations on sets.
-
-  `MapSet`s can also be constructed starting from other collection-type data
-  structures: for example, see `MapSet.new/1` or `Enum.into/2`.
-  """
-
-  @type value :: term
-
-  @opaque t(value) :: %__MODULE__{map: %{optional(value) => []}}
-  @type t :: t(term)
-
-  defstruct map: %{}, version: 2
-
-  @doc """
-  Returns a new set.
-
-  ## Examples
-
-      iex> MapSet.new
-      #MapSet<[]>
-
-  """
-  @spec new :: t
-  def new(), do: %MapSet{}
-
-  @doc """
-  Creates a set from an enumerable.
-
-  ## Examples
-
-      iex> MapSet.new([:b, :a, 3])
-      #MapSet<[3, :a, :b]>
-      iex> MapSet.new([3, 3, 3, 2, 2, 1])
-      #MapSet<[1, 2, 3]>
-
-  """
-  @spec new(Enum.t) :: t
-  def new(enumerable)
-
-  def new(%__MODULE__{} = map_set), do: map_set
-  def new(enumerable) do
-    map =
-      enumerable
-      |> Enum.to_list
-      |> new_from_list([])
-
-    %MapSet{map: map}
-  end
-
-  @doc """
-  Creates a set from an enumerable via the transformation function.
-
-  ## Examples
-
-      iex> MapSet.new([1, 2, 1], fn x -> 2 * x end)
-      #MapSet<[2, 4]>
-
-  """
-  @spec new(Enum.t, (term -> val)) :: t(val) when val: value
-  def new(enumerable, transform) when is_function(transform, 1) do
-    map =
-      enumerable
-      |> Enum.to_list
-      |> new_from_list_transform(transform, [])
-
-    %MapSet{map: map}
-  end
-
-  defp new_from_list([], acc) do
-    :maps.from_list(acc)
-  end
-
-  defp new_from_list([item | rest], acc) do
-    new_from_list(rest, [{item, []} | acc])
-  end
-
-  defp new_from_list_transform([], _fun, acc) do
-    :maps.from_list(acc)
-  end
-  defp new_from_list_transform([item | rest], fun, acc) do
-    new_from_list_transform(rest, fun, [{fun.(item), []} | acc])
-  end
-
-  @doc """
-  Deletes `value` from `map_set`.
-
-  Returns a new set which is a copy of `map_set` but without `value`.
-
-  ## Examples
-
-      iex> map_set = MapSet.new([1, 2, 3])
-      iex> MapSet.delete(map_set, 4)
-      #MapSet<[1, 2, 3]>
-      iex> MapSet.delete(map_set, 2)
-      #MapSet<[1, 3]>
-
-  """
-  @spec delete(t(val1), val2) :: t(val1) when val1: value, val2: value
-  def delete(%MapSet{map: map} = map_set, value) do
-    %{map_set | map: Map.delete(map, value)}
-  end
-
-  @doc """
-  Returns a set that is `map_set1` without the members of `map_set2`.
-
-  ## Examples
-
-      iex> MapSet.difference(MapSet.new([1, 2]), MapSet.new([2, 3, 4]))
-      #MapSet<[1]>
-
-  """
-  @spec difference(t(val1), t(val2)) :: t(val1) when val1: value, val2: value
-  def difference(map_set1, map_set2)
-
-  # If the first set is less than twice the size of the second map,
-  # it is fastest to re-accumulate items in the first set that are not
-  # present in the second set.
-  def difference(%MapSet{map: map1}, %MapSet{map: map2})
-      when map_size(map1) < map_size(map2) * 2 do
-    map =
-      map1
-      |> Map.keys
-      |> filter_not_in(map2)
-
-    %MapSet{map: map}
-  end
-
-  # If the second set is less than half the size of the first set, it's fastest
-  # to simply iterate through each item in the second set, deleting them from
-  # the first set.
-  def difference(%MapSet{map: map1} = map_set, %MapSet{map: map2}) do
-    %{map_set | map: Map.drop(map1, Map.keys(map2))}
-  end
-
-  defp filter_not_in(keys, map2, acc \\ [])
-  defp filter_not_in([], _map2, acc), do: :maps.from_list(acc)
-  defp filter_not_in([key | rest], map2, acc) do
-    acc =
-      if Map.has_key?(map2, key) do
-        acc
-      else
-        [{key, []} | acc]
-      end
-    filter_not_in(rest, map2, acc)
-  end
-
-  @doc """
-  Checks if `map_set1` and `map_set2` have no members in common.
-
-  ## Examples
-
-      iex> MapSet.disjoint?(MapSet.new([1, 2]), MapSet.new([3, 4]))
-      true
-      iex> MapSet.disjoint?(MapSet.new([1, 2]), MapSet.new([2, 3]))
-      false
-
-  """
-  @spec disjoint?(t, t) :: boolean
-  def disjoint?(%MapSet{map: map1}, %MapSet{map: map2}) do
-    {map1, map2} = order_by_size(map1, map2)
-
-    map1
-    |> Map.keys
-    |> none_in?(map2)
-  end
-
-  defp none_in?([], _) do
-    true
-  end
-  defp none_in?([key | rest], map2) do
-    case Map.has_key?(map2, key) do
-      true -> false
-      false -> none_in?(rest, map2)
-    end
-  end
-
-  @doc """
-  Checks if two sets are equal.
-
-  The comparison between elements must be done using `===`.
-
-  ## Examples
-
-      iex> MapSet.equal?(MapSet.new([1, 2]), MapSet.new([2, 1, 1]))
-      true
-      iex> MapSet.equal?(MapSet.new([1, 2]), MapSet.new([3, 4]))
-      false
-
-  """
-  @spec equal?(t, t) :: boolean
-  def equal?(%MapSet{map: map1, version: version}, %MapSet{map: map2, version: version}) do
-    Map.equal?(map1, map2)
-  end
-
-  # Elixir v1.5 change the map representation, so on
-  # version mismatch we need to compare the keys directly.
-  def equal?(%MapSet{map: map1}, %MapSet{map: map2}) do
-    map_size(map1) == map_size(map2) and map_subset?(Map.keys(map1), map2)
-  end
-
-  @doc """
-  Returns a set containing only members that `map_set1` and `map_set2` have in common.
-
-  ## Examples
-
-      iex> MapSet.intersection(MapSet.new([1, 2]), MapSet.new([2, 3, 4]))
-      #MapSet<[2]>
-
-      iex> MapSet.intersection(MapSet.new([1, 2]), MapSet.new([3, 4]))
-      #MapSet<[]>
-
-  """
-  @spec intersection(t(val), t(val)) :: t(val) when val: value
-  def intersection(%MapSet{map: map1} = map_set, %MapSet{map: map2}) do
-    {map1, map2} = order_by_size(map1, map2)
-    %{map_set | map: Map.take(map2, Map.keys(map1))}
-  end
-
-  @doc """
-  Checks if `map_set` contains `value`.
-
-  ## Examples
-
-      iex> MapSet.member?(MapSet.new([1, 2, 3]), 2)
-      true
-      iex> MapSet.member?(MapSet.new([1, 2, 3]), 4)
-      false
-
-  """
-  @spec member?(t, value) :: boolean
-  def member?(%MapSet{map: map}, value) do
-    Map.has_key?(map, value)
-  end
-
-  @doc """
-  Inserts `value` into `map_set` if `map_set` doesn't already contain it.
-
-  ## Examples
-
-      iex> MapSet.put(MapSet.new([1, 2, 3]), 3)
-      #MapSet<[1, 2, 3]>
-      iex> MapSet.put(MapSet.new([1, 2, 3]), 4)
-      #MapSet<[1, 2, 3, 4]>
-
-  """
-  @spec put(t(val), new_val) :: t(val | new_val) when val: value, new_val: value
-  def put(%MapSet{map: map} = map_set, value) do
-    %{map_set | map: Map.put(map, value, [])}
-  end
-
-  @doc """
-  Returns the number of elements in `map_set`.
-
-  ## Examples
-
-      iex> MapSet.size(MapSet.new([1, 2, 3]))
-      3
-
-  """
-  @spec size(t) :: non_neg_integer
-  def size(%MapSet{map: map}) do
-    map_size(map)
-  end
-
-  @doc """
-  Checks if `map_set1`'s members are all contained in `map_set2`.
-
-  This function checks if `map_set1` is a subset of `map_set2`.
-
-  ## Examples
-
-      iex> MapSet.subset?(MapSet.new([1, 2]), MapSet.new([1, 2, 3]))
-      true
-      iex> MapSet.subset?(MapSet.new([1, 2, 3]), MapSet.new([1, 2]))
-      false
-
-  """
-  @spec subset?(t, t) :: boolean
-  def subset?(%MapSet{map: map1}, %MapSet{map: map2}) do
-    if map_size(map1) <= map_size(map2) do
-      map1
-      |> Map.keys
-      |> map_subset?(map2)
-    else
-      false
-    end
-  end
-
-  defp map_subset?([], _), do: true
-  defp map_subset?([key | rest], map2) do
-    if Map.has_key?(map2, key) do
-      map_subset?(rest, map2)
-    else
-      false
-    end
-  end
-
-  @doc """
-  Converts `map_set` to a list.
-
-  ## Examples
-
-      iex> MapSet.to_list(MapSet.new([1, 2, 3]))
-      [1, 2, 3]
-
-  """
-  @spec to_list(t(val)) :: [val] when val: value
-  def to_list(%MapSet{map: map}) do
-    Map.keys(map)
-  end
-
-  @doc """
-  Returns a set containing all members of `map_set1` and `map_set2`.
-
-  ## Examples
-
-      iex> MapSet.union(MapSet.new([1, 2]), MapSet.new([2, 3, 4]))
-      #MapSet<[1, 2, 3, 4]>
-
-  """
-  @spec union(t(val1), t(val2)) :: t(val1 | val2) when val1: value, val2: value
-  def union(map_set1, map_set2)
-
-  def union(%MapSet{map: map1, version: version} = map_set, %MapSet{map: map2, version: version}) do
-    %{map_set | map: Map.merge(map1, map2)}
-  end
-  def union(%MapSet{map: map1}, %MapSet{map: map2}) do
-    new_from_list(Map.keys(map1) ++ Map.keys(map2), [])
-  end
-
-  defp order_by_size(map1, map2) when map_size(map1) > map_size(map2), do: {map2, map1}
-  defp order_by_size(map1, map2), do: {map1, map2}
-
-  defimpl Enumerable do
-    def reduce(map_set, acc, fun), do: Enumerable.List.reduce(MapSet.to_list(map_set), acc, fun)
-    def member?(map_set, val), do: {:ok, MapSet.member?(map_set, val)}
-    def count(map_set), do: {:ok, MapSet.size(map_set)}
-  end
-
-  defimpl Collectable do
-    def into(original) do
-      {original, fn
-        map_set, {:cont, x} -> MapSet.put(map_set, x)
-        map_set, :done -> map_set
-        _, :halt -> :ok
-      end}
-    end
-  end
-
-  defimpl Inspect do
-    import Inspect.Algebra
-
-    def inspect(map_set, opts) do
-      concat ["#MapSet<", Inspect.List.inspect(MapSet.to_list(map_set), opts), ">"]
-    end
-  end
-end

lib/elixir/lib/module/locals_tracker.ex

@@ -1,15 +1,15 @@
-# This is an Elixir module responsible for tracking
+# This is a module Elixir responsible for tracking
 # calls in order to extract Elixir modules' behaviour
 # during compilation time.
 #
 # ## Implementation
 #
 # The implementation uses the digraph module to track
-# all dependencies. The graph starts with one main vertex:
+# all dependencies. The graph starts with one main vertice:
 #
 # * `:local` - points to local functions
 #
-# We can also have the following vertices:
+# We also have can the following vertices:
 #
 # * `Module` - a module that was invoked via an import
 # * `{name, arity}` - a local function/arity pair
@@ -30,7 +30,7 @@
 #   * out neighbours: `Module`
 #
 # Note that since this is required for bootstrap, we can't use
-# any of the `GenServer` conveniences.
+# any of the `GenServer.Behaviour` conveniences.
 defmodule Module.LocalsTracker do
   @moduledoc false
 
@@ -65,15 +65,11 @@ defmodule Module.LocalsTracker do
   """
   @spec reachable(ref) :: [local]
   def reachable(ref) do
-    ref
-    |> to_pid()
-    |> :gen_server.call(:digraph, @timeout)
-    |> reachable_from(:local)
-    |> :sets.to_list()
+    reachable_from(:gen_server.call(to_pid(ref), :digraph, @timeout), :local)
   end
 
   defp reachable_from(d, starting) do
-    reduce_reachable(d, starting, :sets.new)
+    :sets.to_list(reduce_reachable(d, starting, :sets.new))
   end
 
   defp reduce_reachable(d, vertex, vertices) do
@@ -87,12 +83,13 @@ defmodule Module.LocalsTracker do
   defp to_pid(pid) when is_pid(pid),  do: pid
   defp to_pid(mod) when is_atom(mod) do
     table = :elixir_module.data_table(mod)
-    :ets.lookup_element(table, {:elixir, :locals_tracker}, 2)
+    [{_, val}] = :ets.lookup(table, {:elixir, :locals_tracker})
+    val
   end
 
   # Internal API
 
-  # Starts the tracker and returns its PID.
+  # Starts the tracker and returns its pid.
   @doc false
   def start_link do
     :gen_server.start_link(__MODULE__, [], [])
@@ -124,7 +121,7 @@ defmodule Module.LocalsTracker do
     :gen_server.cast(pid, {:add_local, from, to})
   end
 
-  # Adds an import dispatch to the given target.
+  # Adds a import dispatch to the given target.
   @doc false
   def add_import(pid, function, module, target) when is_atom(module) and is_tuple(target) do
     :gen_server.cast(pid, {:add_import, function, module, target})
@@ -147,11 +144,11 @@ defmodule Module.LocalsTracker do
   def collect_imports_conflicts(pid, all_defined) do
     d = :gen_server.call(pid, :digraph, @timeout)
 
-    for {{name, arity}, _, meta, _} <- all_defined,
+    for {name, arity} <- all_defined,
         :digraph.in_neighbours(d, {:import, name, arity}) != [],
         n = :digraph.out_neighbours(d, {:import, name, arity}),
         n != [] do
-      {meta, {n, name, arity}}
+      {n, name, arity}
     end
   end
 
@@ -161,53 +158,73 @@ defmodule Module.LocalsTracker do
   @doc false
   def collect_unused_locals(ref, private) do
     d = :gen_server.call(to_pid(ref), :digraph, @timeout)
-    reachable = reachable_from(d, :local)
-    {unreachable(reachable, private), collect_warnings(reachable, private)}
+    {unreachable(d, private), collect_warnings(d, private)}
   end
 
-  defp unreachable(reachable, private) do
-    for {tuple, _, _, _} <- private,
-        not :sets.is_element(tuple, reachable),
-        do: tuple
+  defp unreachable(d, private) do
+    unreachable = for {tuple, _, _} <- private, do: tuple
+
+    private =
+      for {tuple, :defp, _} <- private do
+        neighbours = :digraph.in_neighbours(d, tuple)
+        neighbours = for {_, _} = t <- neighbours, do: t
+        {tuple, :sets.from_list(neighbours)}
+      end
+
+    reduce_unreachable(private, [], :sets.from_list(unreachable))
   end
 
-  defp collect_warnings(reachable, private) do
-    :lists.foldl(&collect_warnings(&1, &2, reachable), [], private)
-  end
-
-  defp collect_warnings({_, _, false, _}, acc, _reachable) do
-    acc
-  end
-
-  defp collect_warnings({tuple, kind, meta, 0}, acc, reachable) do
-    if :sets.is_element(tuple, reachable) do
-      acc
+  defp reduce_unreachable([{vertex, callers}|t], acc, unreachable) do
+    if :sets.is_subset(callers, unreachable) do
+      reduce_unreachable(t, [{vertex, callers}|acc], unreachable)
     else
-      [{meta, {:unused_def, tuple, kind}} | acc]
+      reduce_unreachable(acc ++ t, [], :sets.del_element(vertex, unreachable))
     end
   end
 
-  defp collect_warnings({tuple, kind, meta, default}, acc, reachable) when default > 0 do
+  defp reduce_unreachable([], _acc, unreachable) do
+    :sets.to_list(unreachable)
+  end
+
+  defp collect_warnings(d, private) do
+    reachable = reachable_from(d, :local)
+    :lists.foldl(&collect_warnings(&1, &2, reachable), [], private)
+  end
+
+  defp collect_warnings({tuple, kind, 0}, acc, reachable) do
+    if :lists.member(tuple, reachable) do
+      acc
+    else
+      [{:unused_def, tuple, kind}|acc]
+    end
+  end
+
+  defp collect_warnings({tuple, kind, default}, acc, reachable) when default > 0 do
     {name, arity} = tuple
     min = arity - default
     max = arity
 
-    case min_reachable_default(max, min, :none, name, reachable) do
-      :none -> [{meta, {:unused_def, tuple, kind}} | acc]
-      ^min -> acc
-      ^max -> [{meta, {:unused_args, tuple}} | acc]
-      diff -> [{meta, {:unused_args, tuple, diff}} | acc]
+    invoked = for {n, a} <- reachable, n == name, a in min..max, do: a
+
+    if invoked == [] do
+      [{:unused_def, tuple, kind}|acc]
+    else
+      case :lists.min(invoked) - min do
+        0 -> acc
+        ^default -> [{:unused_args, tuple}|acc]
+        unused_args -> [{:unused_args, tuple, unused_args}|acc]
+      end
     end
   end
 
-  defp min_reachable_default(max, min, last, name, reachable) when max >= min do
-    case :sets.is_element({name, max}, reachable) do
-      true -> min_reachable_default(max - 1, min, max, name, reachable)
-      false -> min_reachable_default(max - 1, min, last, name, reachable)
-    end
+  @doc false
+  def cache_env(pid, env) do
+    :gen_server.call(pid, {:cache_env, env}, @timeout)
   end
-  defp min_reachable_default(_max, _min, last, _name, _reachable) do
-    last
+
+  @doc false
+  def get_cached_env(pid, ref) do
+    :gen_server.call(pid, {:get_cached_env, ref}, @timeout)
   end
 
   # Stops the gen server
@@ -221,48 +238,68 @@ defmodule Module.LocalsTracker do
   def init([]) do
     d = :digraph.new([:protected])
     :digraph.add_vertex(d, :local)
-    {:ok, d}
-  end
-
-  def handle_call({:yank, local}, _from, d) do
-    out_vertices = :digraph.out_neighbours(d, local)
-    :digraph.del_edges(d, :digraph.out_edges(d, local))
-    {:reply, {[], out_vertices}, d}
-  end
-
-  def handle_call(:digraph, _from, d) do
-    {:reply, d, d}
+    {:ok, {d, []}}
   end
 
   @doc false
-  def handle_info(_msg, d) do
-    {:noreply, d}
+  def handle_call({:cache_env, env}, _from, {d, cache}) do
+    case cache do
+      [{i,^env}|_] ->
+        {:reply, i, {d, cache}}
+      t ->
+        i = length(t)
+        {:reply, i, {d, [{i,env}|t]}}
+    end
   end
 
-  def handle_cast({:add_local, from, to}, d) do
+  def handle_call({:get_cached_env, ref}, _from, {_, cache} = state) do
+    {^ref, env} = :lists.keyfind(ref, 1, cache)
+    {:reply, env, state}
+  end
+
+  def handle_call({:yank, local}, _from, {d, _} = state) do
+    out_vertices = :digraph.out_neighbours(d, local)
+    :digraph.del_edges(d, :digraph.out_edges(d, local))
+    {:reply, {[], out_vertices}, state}
+  end
+
+  def handle_call(:digraph, _from, {d, _} = state) do
+    {:reply, d, state}
+  end
+
+  def handle_call(request, _from, state) do
+    {:stop, {:bad_call, request}, state}
+  end
+
+  @doc false
+  def handle_info(_msg, state) do
+    {:noreply, state}
+  end
+
+  def handle_cast({:add_local, from, to}, {d, _} = state) do
     handle_add_local(d, from, to)
-    {:noreply, d}
+    {:noreply, state}
   end
 
-  def handle_cast({:add_import, function, module, {name, arity}}, d) do
+  def handle_cast({:add_import, function, module, {name, arity}}, {d, _} = state) do
     handle_import(d, function, module, name, arity)
-    {:noreply, d}
+    {:noreply, state}
   end
 
-  def handle_cast({:add_definition, kind, tuple}, d) do
+  def handle_cast({:add_definition, kind, tuple}, {d, _} = state) do
     handle_add_definition(d, kind, tuple)
-    {:noreply, d}
+    {:noreply, state}
   end
 
-  def handle_cast({:add_defaults, kind, {name, arity}, defaults}, d) do
+  def handle_cast({:add_defaults, kind, {name, arity}, defaults}, {d, _} = state) do
     for i <- :lists.seq(arity - defaults, arity - 1) do
       handle_add_definition(d, kind, {name, i})
-      handle_add_local(d, {name, i}, {name, arity})
+      handle_add_local(d, {name, i}, {name, i + 1})
     end
-    {:noreply, d}
+    {:noreply, state}
   end
 
-  def handle_cast({:reattach, _kind, tuple, {in_neigh, out_neigh}}, d) do
+  def handle_cast({:reattach, _kind, tuple, {in_neigh, out_neigh}}, {d, _} = state) do
     for from <- in_neigh do
       :digraph.add_vertex(d, from)
       replace_edge!(d, from, tuple)
@@ -273,11 +310,15 @@ defmodule Module.LocalsTracker do
       replace_edge!(d, tuple, to)
     end
 
-    {:noreply, d}
+    {:noreply, state}
   end
 
-  def handle_cast(:stop, d) do
-    {:stop, :normal, d}
+  def handle_cast(:stop, state) do
+    {:stop, :normal, state}
+  end
+
+  def handle_cast(msg, state) do
+    {:stop, {:bad_cast, msg}, state}
   end
 
   @doc false
@@ -320,7 +361,7 @@ defmodule Module.LocalsTracker do
 
   defp replace_edge!(d, from, to) do
     _ = unless :lists.member(to, :digraph.out_neighbours(d, from)) do
-      [:"$e" | _] = :digraph.add_edge(d, from, to)
+      [:"$e"|_] = :digraph.add_edge(d, from, to)
     end
     :ok
   end

lib/elixir/lib/node.ex

@@ -72,8 +72,7 @@ defmodule Node do
   The result returned when the argument is a list, is the list of nodes
   satisfying the disjunction(s) of the list elements.
 
-  For more information, see
-  [`:erlang.nodes/1`](http://www.erlang.org/doc/man/erlang.html#nodes-1).
+  See http://www.erlang.org/doc/man/erlang.html#nodes-1 for more info.
   """
   @typep state :: :visible | :hidden | :connected | :this | :known
   @spec list(state | [state]) :: [t]
@@ -87,11 +86,7 @@ defmodule Node do
   If `flag` is `true`, monitoring is turned on.
   If `flag` is `false`, monitoring is turned off.
 
-  For more information, see
-  [`:erlang.monitor_node/2`](http://www.erlang.org/doc/man/erlang.html#monitor_node-2).
-  
-  For monitoring status changes of all nodes, see
-  [`:net_kernel.monitor_nodes/3`](http://www.erlang.org/doc/man/net_kernel.html#monitor_nodes-2).
+  See http://www.erlang.org/doc/man/erlang.html#monitor_node-2 for more info.
   """
   @spec monitor(t, boolean) :: true
   def monitor(node, flag) do
@@ -102,11 +97,7 @@ defmodule Node do
   Behaves as `monitor/2` except that it allows an extra
   option to be given, namely `:allow_passive_connect`.
 
-  For more information, see
-  [`:erlang.monitor_node/3`](http://www.erlang.org/doc/man/erlang.html#monitor_node-3).
-  
-  For monitoring status changes of all nodes, see
-  [`:net_kernel.monitor_nodes/3`](http://www.erlang.org/doc/man/net_kernel.html#monitor_nodes-2).
+  See http://www.erlang.org/doc/man/erlang.html#monitor_node-3 for more info.
   """
   @spec monitor(t, boolean, [:allow_passive_connect]) :: true
   def monitor(node, flag, options) do
@@ -137,8 +128,7 @@ defmodule Node do
   protocols. Returns `true` if disconnection succeeds, otherwise `false`.
   If the local node is not alive, the function returns `:ignored`.
 
-  For more information, see
-  [`:erlang.disconnect_node/1`](http://www.erlang.org/doc/man/erlang.html#disconnect_node-1).
+  See http://www.erlang.org/doc/man/erlang.html#disconnect_node-1 for more info.
   """
   @spec disconnect(t) :: boolean | :ignored
   def disconnect(node) do
@@ -151,8 +141,7 @@ defmodule Node do
   Returns `true` if successful, `false` if not, and the atom
   `:ignored` if the local node is not alive.
 
-  For more information, see
-  [`:net_kernel.connect_node/1`](http://www.erlang.org/doc/man/net_kernel.html#connect_node-1).
+  See http://erlang.org/doc/man/net_kernel.html#connect_node-1 for more info.
   """
   @spec connect(t) :: boolean | :ignored
   def connect(node) do
@@ -160,11 +149,11 @@ defmodule Node do
   end
 
   @doc """
-  Returns the PID of a new process started by the application of `fun`
-  on `node`. If `node` does not exist, a useless PID is returned.
+  Returns the pid of a new process started by the application of `fun`
+  on `node`. If `node` does not exist, a useless pid is returned.
 
-  For the list of available options, see
-  [`:erlang.spawn/2`](http://www.erlang.org/doc/man/erlang.html#spawn-2).
+  Check http://www.erlang.org/doc/man/erlang.html#spawn-2 for
+  the list of available options.
 
   Inlined by the compiler.
   """
@@ -174,13 +163,12 @@ defmodule Node do
   end
 
   @doc """
-  Returns the PID of a new process started by the application of `fun`
+  Returns the pid of a new process started by the application of `fun`
   on `node`.
 
-  If `node` does not exist, a useless PID is returned.
-
-  For the list of available options, see
-  [`:erlang.spawn_opt/3`](http://www.erlang.org/doc/man/erlang.html#spawn_opt-3).
+  If `node` does not exist, a useless pid is returned. Check
+  http://www.erlang.org/doc/man/erlang.html#spawn_opt-3 for the list of
+  available options.
 
   Inlined by the compiler.
   """
@@ -190,13 +178,12 @@ defmodule Node do
   end
 
   @doc """
-  Returns the PID of a new process started by the application of
+  Returns the pid of a new process started by the application of
   `module.function(args)` on `node`.
 
-  If `node` does not exist, a useless PID is returned.
-
-  For the list of available options, see
-  [`:erlang.spawn/4`](http://www.erlang.org/doc/man/erlang.html#spawn-4).
+  If `node` does not exist, a useless pid is returned. Check
+  http://www.erlang.org/doc/man/erlang.html#spawn-4 for the list of
+  available options.
 
   Inlined by the compiler.
   """
@@ -206,13 +193,12 @@ defmodule Node do
   end
 
   @doc """
-  Returns the PID of a new process started by the application of
+  Returns the pid of a new process started by the application of
   `module.function(args)` on `node`.
 
-  If `node` does not exist, a useless PID is returned.
-
-  For the list of available options, see
-  [`:erlang.spawn/5`](http://www.erlang.org/doc/man/erlang.html#spawn_opt-5).
+  If `node` does not exist, a useless pid is returned. Check
+  http://www.erlang.org/doc/man/erlang.html#spawn_opt-5 for the list of
+  available options.
 
   Inlined by the compiler.
   """
@@ -222,10 +208,10 @@ defmodule Node do
   end
 
   @doc """
-  Returns the PID of a new linked process started by the application of `fun` on `node`.
+  Returns the pid of a new linked process started by the application of `fun` on `node`.
 
   A link is created between the calling process and the new process, atomically.
-  If `node` does not exist, a useless PID is returned (and due to the link, an exit
+  If `node` does not exist, a useless pid is returned (and due to the link, an exit
   signal with exit reason `:noconnection` will be received).
 
   Inlined by the compiler.
@@ -236,11 +222,11 @@ defmodule Node do
   end
 
   @doc """
-  Returns the PID of a new linked process started by the application of
+  Returns the pid of a new linked process started by the application of
   `module.function(args)` on `node`.
 
   A link is created between the calling process and the new process, atomically.
-  If `node` does not exist, a useless PID is returned (and due to the link, an exit
+  If `node` does not exist, a useless pid is returned (and due to the link, an exit
   signal with exit reason `:noconnection` will be received).
 
   Inlined by the compiler.
@@ -253,7 +239,7 @@ defmodule Node do
   @doc """
   Sets the magic cookie of `node` to the atom `cookie`.
 
-  The default node is `Node.self/0`, the local node. If `node` is the local node,
+  The default node is `Node.self`, the local node. If `node` is the local node,
   the function also sets the cookie of all other unknown nodes to `cookie`.
 
   This function will raise `FunctionClauseError` if the given `node` is not alive.

lib/elixir/lib/option_parser.ex

@@ -1,165 +1,73 @@
 defmodule OptionParser do
   @moduledoc """
-  This module contains functions to parse command line options.
+  This module contains functions to parse command line arguments.
   """
 
   @type argv    :: [String.t]
-  @type parsed  :: keyword
+  @type parsed  :: Keyword.t
   @type errors  :: [{String.t, String.t | nil}]
-  @type options :: [switches: keyword, strict: keyword, aliases: keyword]
-
-  defmodule ParseError do
-    defexception [:message]
-  end
+  @type options :: [switches: Keyword.t, strict: Keyword.t, aliases: Keyword.t]
 
   @doc """
-  Parses `argv` into a keyword list.
+  Parses `argv` into a keywords list.
 
-  It returns a three-element tuple with the form `{parsed, args, invalid}`, where:
+  It returns the parsed values, remaining arguments and the
+  invalid options.
 
-    * `parsed` is a keyword list of parsed switches with `{switch_name, value}`
-      tuples in it; `switch_name` is the atom representing the switch name while
-      `value` is the value for that switch parsed according to `opts` (see the
-      "Examples" section for more information)
-    * `args` is a list of the remaining arguments in `argv` as strings
-    * `invalid` is a list of invalid options as `{option_name, value}` where
-      `option_name` is the raw option and `value` is `nil` if the option wasn't
-      expected or the string value if the value didn't have the expected type for
-      the corresponding option
-
-  Elixir converts switches to underscored atoms, so `--source-path` becomes
-  `:source_path`. This is done to better suit Elixir conventions. However, this
-  means that switches can't contain underscores and switches that do contain
-  underscores are always returned in the list of invalid switches.
-
-  When parsing, it is common to list switches and their expected types:
-
-      iex> OptionParser.parse(["--debug"], switches: [debug: :boolean])
-      {[debug: true], [], []}
-
-      iex> OptionParser.parse(["--source", "lib"], switches: [source: :string])
-      {[source: "lib"], [], []}
-
-      iex> OptionParser.parse(["--source-path", "lib", "test/enum_test.exs", "--verbose"],
-      ...>                    switches: [source_path: :string, verbose: :boolean])
-      {[source_path: "lib", verbose: true], ["test/enum_test.exs"], []}
-
-  We will explore the valid switches and operation modes of option parser below.
-
-  ## Options
-
-  The following options are supported:
-
-    * `:switches` or `:strict` - see the "Switch definitions" section below
-    * `:allow_nonexistent_atoms` - see the "Parsing dynamic switches" section below
-    * `:aliases` - see the "Aliases" section below
-
-  ## Switch definitions
-
-  Switches can be specified via one of two options:
-
-    * `:switches` - defines some switches and their types. This function
-      still attempts to parse switches that are not in this list.
-    * `:strict` - defines strict switches. Any switch in `argv` that is not
-      specified in the list is returned in the invalid options list.
-
-  Both these options accept a keyword list of `{name, type}` tuples where `name`
-  is an atom defining the name of the switch and `type` is an atom that
-  specifies the type for the value of this switch (see the "Types" section below
-  for the possible types and more information about type casting).
-
-  Note that you should only supply the `:switches` or the`:strict` option.
-  If you supply both, an `ArgumentError` exception will be raised.
-
-  ### Types
-
-  Switches parsed by `OptionParser` may take zero or one arguments.
-
-  The following switches types take no arguments:
-
-    * `:boolean` - sets the value to `true` when given (see also the
-      "Negation switches" section below)
-    * `:count` - counts the number of times the switch is given
-
-  The following switches take one argument:
-
-    * `:integer` - parses the value as an integer
-    * `:float` - parses the value as a float
-    * `:string` - parses the value as a string
-
-  If a switch can't be parsed according to the given type, it is
-  returned in the invalid options list.
-
-  ### Modifiers
-
-  Switches can be specified with modifiers, which change how
-  they behave. The following modifiers are supported:
-
-    * `:keep` - keeps duplicated items instead of overriding them;
-      works with all types except `:count`. Specifying `switch_name: :keep`
-      assumes the type of `:switch_name` will be `:string`.
-
-  To use `:keep` with a type other than `:string`, use a list as the type
-  for the switch. For example: `[foo: [:integer, :keep]]`.
-
-  ### Negation switches
-
-  In case a switch `SWITCH` is specified to have type `:boolean`, it may be
-  passed as `--no-SWITCH` as well which will set the option to `false`:
-
-      iex> OptionParser.parse(["--no-op", "path/to/file"], switches: [op: :boolean])
-      {[op: false], ["path/to/file"], []}
-
-  ### Parsing dynamic switches
-
-  `OptionParser` also includes a dynamic mode where it will attempt to parse
-  switches dynamically. Such can be done by not specifying the `:switches` or
-  `:strict` option.
+  ## Examples
 
       iex> OptionParser.parse(["--debug"])
       {[debug: true], [], []}
 
+      iex> OptionParser.parse(["--source", "lib"])
+      {[source: "lib"], [], []}
 
-  Switches followed by a value will be assigned the value, as a string. Switches
-  without an argument, like `--debug` in the examples above, will automatically be
-  set to `true`.
+      iex> OptionParser.parse(["--source-path", "lib", "test/enum_test.exs", "--verbose"])
+      {[source_path: "lib", verbose: true], ["test/enum_test.exs"], []}
 
-  Since Elixir converts switches to atoms, the dynamic mode will only parse
-  switches that translate to atoms used by the runtime. Therefore, the code below
-  likely won't parse the given option since the `:option_parser_example` atom is
-  never used anywhere:
+  By default, Elixir will try to automatically parse switches.
+  Switches without an argument, like `--debug` will automatically
+  be set to true. Switches followed by a value will be assigned
+  to the value, always as strings.
 
-      OptionParser.parse(["--option-parser-example"])
-      # The :option_parser_example atom is not used anywhere below
+  Note Elixir also converts the switches to underscore atoms, as
+  `--source-path` becomes `:source_path`, to better suit Elixir
+  conventions. This means that option names on the command line cannot contain
+  underscores; such options will be reported as `:undefined` (in strict mode)
+  or `:invalid` (in basic mode).
 
-  However, the code below does since the `:option_parser_example` atom is used
-  at some point later (or earlier) on:
+  ## Switches
 
-      {opts, _, _} = OptionParser.parse(["--option-parser-example"])
-      opts[:option_parser_example]
+  Many times though, it is better to explicitly list the available
+  switches and their formats. The switches can be specified via two
+  different options:
 
-  In other words, when using dynamic mode, Elixir will do the correct thing and
-  only parse options that are used by the runtime, ignoring all others. If you
-  would like to parse all switches, regardless if they exist or not, you can
-  force creation of atoms by passing `allow_nonexistent_atoms: true` as option.
-  Such option is useful when you are building command-line applications that
-  receive dynamically-named arguments but must be used with care on long-running
-  systems.
+    * `:strict` - the switches are strict. Any switch that does not
+      exist in the switch list is treated as an error.
 
-  Switches followed by a value will be assigned the value, as a string.
-  Switches without an argument, like `--debug` in the examples above, will
-  automatically be set to `true`.
+    * `:switches` - defines some switches. Switches that does not
+      exist in the switch list are still attempted to be parsed.
 
-  ## Aliases
+  Note only `:strict` or `:switches` may be given at once.
 
-  A set of aliases can be specified in the `:aliases` option:
+  For each switch, the following types are supported:
 
-      iex> OptionParser.parse(["-d"], aliases: [d: :debug])
-      {[debug: true], [], []}
+    * `:boolean` - marks the given switch as a boolean. Boolean switches
+                   never consume the following value unless it is `true` or
+                   `false`.
+    * `:integer` - parses the switch as an integer.
+    * `:float`   - parses the switch as a float.
+    * `:string`  - returns the switch as a string.
 
-  ## Examples
+  If a switch can't be parsed or is not specified in the strict case,
+  the option is returned in the invalid options list (third element
+  of the returned tuple).
 
-  Here are some examples of working with different types and modifiers:
+  The following extra "types" are supported:
+
+    * `:keep` - keeps duplicated items in the list instead of overriding
+
+  Examples:
 
       iex> OptionParser.parse(["--unlock", "path/to/file"], strict: [unlock: :boolean])
       {[unlock: true], ["path/to/file"], []}
@@ -174,12 +82,6 @@ defmodule OptionParser do
       iex> OptionParser.parse(["--limit", "xyz"], strict: [limit: :integer])
       {[], [], [{"--limit", "xyz"}]}
 
-      iex> OptionParser.parse(["--verbose"], switches: [verbose: :count])
-      {[verbose: 1], [], []}
-
-      iex> OptionParser.parse(["-v", "-v"], aliases: [v: :verbose], strict: [verbose: :count])
-      {[verbose: 2], [], []}
-
       iex> OptionParser.parse(["--unknown", "xyz"], strict: [])
       {[], ["xyz"], [{"--unknown", nil}]}
 
@@ -187,50 +89,25 @@ defmodule OptionParser do
       ...>                    switches: [limit: :integer])
       {[limit: 3, unknown: "xyz"], [], []}
 
-      iex> OptionParser.parse(["--unlock", "path/to/file", "--unlock", "path/to/another/file"], strict: [unlock: :keep])
-      {[unlock: "path/to/file", unlock: "path/to/another/file"], [], []}
+  ## Negation switches
+
+  In case a switch is declared as boolean, it may be passed as `--no-SWITCH`
+  which will set the option to false:
+
+      iex> OptionParser.parse(["--no-op", "path/to/file"], switches: [op: :boolean])
+      {[op: false], ["path/to/file"], []}
+
+  ## Aliases
+
+  A set of aliases can be given as options too:
+
+      iex> OptionParser.parse(["-d"], aliases: [d: :debug])
+      {[debug: true], [], []}
 
   """
   @spec parse(argv, options) :: {parsed, argv, errors}
   def parse(argv, opts \\ []) when is_list(argv) and is_list(opts) do
-    do_parse(argv, build_config(opts), [], [], [], true)
-  end
-
-  @doc """
-  The same as `parse/2` but raises an `OptionParser.ParseError`
-  exception if any invalid options are given.
-
-  If there are no errors, returns a `{parsed, rest}` tuple where:
-
-    * `parsed` is the list of parsed switches (same as in `parse/2`)
-    * `rest` is the list of arguments (same as in `parse/2`)
-
-  ## Examples
-
-      iex> OptionParser.parse!(["--debug", "path/to/file"], strict: [debug: :boolean])
-      {[debug: true], ["path/to/file"]}
-
-      iex> OptionParser.parse!(["--limit", "xyz"], strict: [limit: :integer])
-      ** (OptionParser.ParseError) 1 error found!
-      --limit : Expected type integer, got "xyz"
-
-      iex> OptionParser.parse!(["--unknown", "xyz"], strict: [])
-      ** (OptionParser.ParseError) 1 error found!
-      --unknown : Unknown option
-
-      iex> OptionParser.parse!(["-l", "xyz", "-f", "bar"],
-      ...>                     switches: [limit: :integer, foo: :integer], aliases: [l: :limit, f: :foo])
-      ** (OptionParser.ParseError) 2 errors found!
-      -l : Expected type integer, got "xyz"
-      -f : Expected type integer, got "bar"
-
-  """
-  @spec parse!(argv, options) :: {parsed, argv} | no_return
-  def parse!(argv, opts \\ []) when is_list(argv) and is_list(opts) do
-    case parse(argv, opts) do
-      {parsed, args, []} -> {parsed, args}
-      {_, _, errors} -> raise ParseError, format_errors(errors, opts)
-    end
+    do_parse(argv, compile_config(opts), [], [], [], true)
   end
 
   @doc """
@@ -241,81 +118,45 @@ defmodule OptionParser do
 
   ## Example
 
-      iex> OptionParser.parse_head(["--source", "lib", "test/enum_test.exs", "--verbose"],
-      ...>                         switches: [source: :string, verbose: :boolean])
+      iex> OptionParser.parse_head(["--source", "lib", "test/enum_test.exs", "--verbose"])
       {[source: "lib"], ["test/enum_test.exs", "--verbose"], []}
 
-      iex> OptionParser.parse_head(["--verbose", "--source", "lib", "test/enum_test.exs", "--unlock"],
-      ...>                         switches: [source: :string, verbose: :boolean, unlock: :boolean])
+      iex> OptionParser.parse_head(["--verbose", "--source", "lib", "test/enum_test.exs", "--unlock"])
       {[verbose: true, source: "lib"], ["test/enum_test.exs", "--unlock"], []}
 
   """
   @spec parse_head(argv, options) :: {parsed, argv, errors}
   def parse_head(argv, opts \\ []) when is_list(argv) and is_list(opts) do
-    do_parse(argv, build_config(opts), [], [], [], false)
-  end
-
-  @doc """
-  The same as `parse_head/2` but raises an `OptionParser.ParseError`
-  exception if any invalid options are given.
-
-  If there are no errors, returns a `{parsed, rest}` tuple where:
-
-    * `parsed` is the list of parsed switches (same as in `parse_head/2`)
-    * `rest` is the list of arguments (same as in `parse_head/2`)
-
-  ## Examples
-
-      iex> OptionParser.parse_head!(["--source", "lib", "path/to/file", "--verbose"],
-      ...>                         switches: [source: :string, verbose: :boolean])
-      {[source: "lib"], ["path/to/file", "--verbose"]}
-
-      iex> OptionParser.parse_head!(["--number", "lib", "test/enum_test.exs", "--verbose"],
-      ...>                          strict: [number: :integer])
-      ** (OptionParser.ParseError) 1 error found!
-      --number : Expected type integer, got "lib"
-
-      iex> OptionParser.parse_head!(["--verbose", "--source", "lib", "test/enum_test.exs", "--unlock"],
-      ...>                          strict: [verbose: :integer, source: :integer])
-      ** (OptionParser.ParseError) 2 errors found!
-      --verbose : Missing argument of type integer
-      --source : Expected type integer, got "lib"
-  """
-  @spec parse_head!(argv, options) :: {parsed, argv} | no_return
-  def parse_head!(argv, opts \\ []) when is_list(argv) and is_list(opts) do
-    case parse_head(argv, opts) do
-      {parsed, args, []} -> {parsed, args}
-      {_, _, errors} -> raise ParseError, format_errors(errors, opts)
-    end
+    do_parse(argv, compile_config(opts), [], [], [], false)
   end
 
   defp do_parse([], _config, opts, args, invalid, _all?) do
     {Enum.reverse(opts), Enum.reverse(args), Enum.reverse(invalid)}
   end
 
-  defp do_parse(argv, %{switches: switches} = config, opts, args, invalid, all?) do
-    case next_with_config(argv, config) do
+  defp do_parse(argv, {aliases, switches, strict}=config, opts, args, invalid, all?) do
+    case next(argv, aliases, switches, strict) do
       {:ok, option, value, rest} ->
-        # the option exists and it was successfully parsed
+        # the option exist and it was successfully parsed
         kinds = List.wrap Keyword.get(switches, option)
-        new_opts = store_option(opts, option, value, kinds)
+        new_opts = do_store_option(opts, option, value, kinds)
         do_parse(rest, config, new_opts, args, invalid, all?)
 
       {:invalid, option, value, rest} ->
         # the option exist but it has wrong value
-        do_parse(rest, config, opts, args, [{option, value} | invalid], all?)
+        do_parse(rest, config, opts, args, [{option, value}|invalid], all?)
 
       {:undefined, option, _value, rest} ->
         # the option does not exist (for strict cases)
-        do_parse(rest, config, opts, args, [{option, nil} | invalid], all?)
+        do_parse(rest, config, opts, args, [{option, nil}|invalid], all?)
 
-      {:error, ["--" | rest]} ->
+      {:error, ["--"|rest]} ->
         {Enum.reverse(opts), Enum.reverse(args, rest), Enum.reverse(invalid)}
 
-      {:error, [arg | rest] = remaining_args} ->
+      {:error, [arg|rest]=remaining_args} ->
         # there is no option
         if all? do
-          do_parse(rest, config, opts, [arg | args], invalid, all?)
+          do_parse(rest, config, opts, [arg|args], invalid, all?)
         else
           {Enum.reverse(opts), Enum.reverse(args, remaining_args), Enum.reverse(invalid)}
         end
@@ -326,21 +167,22 @@ defmodule OptionParser do
   Low-level function that parses one option.
 
   It accepts the same options as `parse/2` and `parse_head/2`
-  as both functions are built on top of this function. This function
+  as both functions are built on top of next. This function
   may return:
 
     * `{:ok, key, value, rest}` - the option `key` with `value` was
       successfully parsed
 
     * `{:invalid, key, value, rest}` - the option `key` is invalid with `value`
-      (returned when the value cannot be parsed according to the switch type)
+      (returned when the switch type does not match the one given via the
+      command line)
 
     * `{:undefined, key, value, rest}` - the option `key` is undefined
-      (returned in strict mode when the switch is unknown)
-
-    * `{:error, rest}` - there are no switches at the head of the given `argv`
+      (returned on strict cases and the switch is unknown)
 
+    * `{:error, rest}` - there are no switches at the top of the given argv
   """
+
   @spec next(argv, options) ::
         {:ok, key :: atom, value :: term, argv} |
         {:invalid, String.t, String.t | nil, argv} |
@@ -348,132 +190,79 @@ defmodule OptionParser do
         {:error, argv}
 
   def next(argv, opts \\ []) when is_list(argv) and is_list(opts) do
-    next_with_config(argv, build_config(opts))
+    {aliases, switches, strict} = compile_config(opts)
+    next(argv, aliases, switches, strict)
   end
 
-  defp next_with_config([], _config) do
+  defp next([], _aliases, _switches, _strict) do
     {:error, []}
   end
 
-  defp next_with_config(["--" | _] = argv, _config) do
+  defp next(["--"|_]=argv, _aliases, _switches, _strict) do
     {:error, argv}
   end
 
-  defp next_with_config(["-" | _] = argv, _config) do
+  defp next(["-"|_]=argv, _aliases, _switches, _strict) do
     {:error, argv}
   end
 
-  defp next_with_config(["- " <> _ | _] = argv, _config) do
+  defp next(["- " <> _|_]=argv, _aliases, _switches, _strict) do
     {:error, argv}
   end
 
-  # Handles --foo or --foo=bar
-  defp next_with_config(["--" <> option | rest], config) do
+  defp next(["-" <> option|rest], aliases, switches, strict) do
     {option, value} = split_option(option)
-    tagged = tag_option(option, config)
-    next_tagged(tagged, value, "--" <> option, rest, config)
-  end
+    opt_name_bin = "-" <> option
+    tagged = tag_option(option, switches, aliases)
 
-  # Handles -a, -abc, -abc=something
-  defp next_with_config(["-" <> option | rest] = argv, config) do
-    %{aliases: aliases, allow_nonexistent_atoms?: allow_nonexistent_atoms?} = config
-    {option, value} = split_option(option)
-    original = "-" <> option
-
-    cond do
-      is_nil(value) and negative_number?(original) ->
-        {:error, argv}
-      String.contains?(option, ["-", "_"]) ->
-        {:undefined, original, value, rest}
-      String.length(option) > 1 ->
-        key = get_option_key(option, allow_nonexistent_atoms?)
-        option_key = aliases[key]
-        if key && option_key do
-          IO.warn "multi-letter aliases are deprecated, got: #{inspect(key)}"
-          next_tagged({:default, option_key}, value, original, rest, config)
-        else
-          next_with_config(expand_multiletter_alias(option, value) ++ rest, config)
-        end
-      true ->
-        # We have a regular one-letter alias here
-        tagged = tag_oneletter_alias(option, config)
-        next_tagged(tagged, value, original, rest, config)
-    end
-  end
-
-  defp next_with_config(argv, _config) do
-    {:error, argv}
-  end
-
-  defp next_tagged(tagged, value, original, rest, %{switches: switches, strict?: strict?}) do
-    if strict? and not option_defined?(tagged, switches) do
-      {:undefined, original, value, rest}
+    if strict and not option_defined?(tagged, switches) do
+      {:undefined, opt_name_bin, value, rest}
     else
-      {option, kinds, value} = normalize_option(tagged, value, switches)
-      {value, kinds, rest} = normalize_value(value, kinds, rest, strict?)
+      {opt_name, kinds, value} = normalize_option(tagged, value, switches)
+      {value, kinds, rest} = normalize_value(value, kinds, rest, strict)
       case validate_option(value, kinds) do
-        {:ok, new_value} -> {:ok, option, new_value, rest}
-        :invalid         -> {:invalid, original, value, rest}
+        {:ok, new_value} -> {:ok, opt_name, new_value, rest}
+        :invalid         -> {:invalid, opt_name_bin, value, rest}
       end
     end
   end
 
+  defp next(argv, _aliases, _switches, _strict) do
+    {:error, argv}
+  end
+
   @doc """
-  Receives a key-value enumerable and converts it to `t:argv/0`.
+  Receives a key-value enumerable and convert it to argv.
 
-  Keys must be atoms. Keys with `nil` value are discarded,
+  Keys must be atoms. Keys with nil value are discarded,
   boolean values are converted to `--key` or `--no-key`
-  (if the value is `true` or `false`, respectively),
-  and all other values are converted using `Kernel.to_string/1`.
-
-  It is advised to pass to `to_argv/2` the same set of `options`
-  given to `parse/2`. Some switches can only be reconstructed
-  correctly with the `switches` information in hand.
+  and all other values are converted using `to_string/1`.
 
   ## Examples
 
       iex>  OptionParser.to_argv([foo_bar: "baz"])
       ["--foo-bar", "baz"]
+
       iex>  OptionParser.to_argv([bool: true, bool: false, discarded: nil])
       ["--bool", "--no-bool"]
 
-  Some switches will output different values based on the switches
-  flag:
-
-      iex> OptionParser.to_argv([number: 2], switches: [])
-      ["--number", "2"]
-      iex> OptionParser.to_argv([number: 2], switches: [number: :count])
-      ["--number", "--number"]
-
   """
-  @spec to_argv(Enumerable.t, options) :: argv
-  def to_argv(enum, opts \\ []) do
-    switches = Keyword.get(opts, :switches, [])
+  @spec to_argv(Enumerable.t) :: argv
+  def to_argv(enum) do
     Enum.flat_map(enum, fn
       {_key, nil}  -> []
       {key, true}  -> [to_switch(key)]
       {key, false} -> [to_switch(key, "--no-")]
-      {key, value} -> to_argv(key, value, switches)
+      {key, value} -> [to_switch(key), to_string(value)]
     end)
   end
 
-  defp to_argv(key, value, switches) do
-    if switches[key] == :count do
-      List.duplicate(to_switch(key), value)
-    else
-      [to_switch(key), to_string(value)]
-    end
-  end
-
   defp to_switch(key, prefix \\ "--") when is_atom(key) do
     prefix <> String.replace(Atom.to_string(key), "_", "-")
   end
 
   @doc ~S"""
-  Splits a string into `t:argv/0` chunks.
-
-  This function splits the given `string` into a list of strings in a similar
-  way to many shells.
+  Splits a string into argv chunks.
 
   ## Examples
 
@@ -482,32 +271,31 @@ defmodule OptionParser do
 
       iex> OptionParser.split("foo \"bar baz\"")
       ["foo", "bar baz"]
-
   """
   @spec split(String.t) :: argv
-  def split(string) when is_binary(string) do
-    do_split(String.trim_leading(string, " "), "", [], nil)
+  def split(string) do
+    do_split(strip_leading_spaces(string), "", [], nil)
   end
 
-  # If we have an escaped quote, simply remove the escape
-  defp do_split(<<?\\, quote, t::binary>>, buffer, acc, quote),
+  # If we have a escaped quote, simply remove the escape
+  defp do_split(<<?\\, quote, t :: binary>>, buffer, acc, quote),
     do: do_split(t, <<buffer::binary, quote>>, acc, quote)
 
   # If we have a quote and we were not in a quote, start one
-  defp do_split(<<quote, t::binary>>, buffer, acc, nil) when quote in [?", ?'],
+  defp do_split(<<quote, t :: binary>>, buffer, acc, nil) when quote in [?", ?'],
     do: do_split(t, buffer, acc, quote)
 
   # If we have a quote and we were inside it, close it
-  defp do_split(<<quote, t::binary>>, buffer, acc, quote),
+  defp do_split(<<quote, t :: binary>>, buffer, acc, quote),
     do: do_split(t, buffer, acc, nil)
 
-  # If we have an escaped quote/space, simply remove the escape as long as we are not inside a quote
-  defp do_split(<<?\\, h, t::binary>>, buffer, acc, nil) when h in [?\s, ?', ?"],
+  # If we have a escaped quote/space, simply remove the escape as long as we are not inside a quote
+  defp do_split(<<?\\, h, t :: binary>>, buffer, acc, nil) when h in [?\s, ?', ?"],
     do: do_split(t, <<buffer::binary, h>>, acc, nil)
 
   # If we have space and we are outside of a quote, start new segment
-  defp do_split(<<?\s, t::binary>>, buffer, acc, nil),
-    do: do_split(String.trim_leading(t, " "), "", [buffer | acc], nil)
+  defp do_split(<<?\s, t :: binary>>, buffer, acc, nil),
+    do: do_split(strip_leading_spaces(t), "", [buffer|acc], nil)
 
   # All other characters are moved to buffer
   defp do_split(<<h, t::binary>>, buffer, acc, quote) do
@@ -519,119 +307,86 @@ defmodule OptionParser do
     do: Enum.reverse(acc)
 
   defp do_split(<<>>, buffer, acc, nil),
-    do: Enum.reverse([buffer | acc])
+    do: Enum.reverse([buffer|acc])
 
   # Otherwise raise
   defp do_split(<<>>, _, _acc, marker) do
     raise "argv string did not terminate properly, a #{<<marker>>} was opened but never closed"
   end
 
+  defp strip_leading_spaces(" " <> t), do: strip_leading_spaces(t)
+  defp strip_leading_spaces(t), do: t
+
   ## Helpers
 
-  defp build_config(opts) do
-    {switches, strict?} = cond do
-      opts[:switches] && opts[:strict] ->
-        raise ArgumentError, ":switches and :strict cannot be given together"
-      switches = opts[:switches] ->
-        {switches, false}
-      strict = opts[:strict] ->
-        {strict, true}
+  defp compile_config(opts) do
+    aliases = opts[:aliases] || []
+
+    {switches, strict} = cond do
+      s = opts[:switches] ->
+        {s, false}
+      s = opts[:strict] ->
+        {s, true}
       true ->
         {[], false}
     end
 
-    %{
-      aliases: opts[:aliases] || [],
-      allow_nonexistent_atoms?: opts[:allow_nonexistent_atoms] || false,
-      strict?: strict?,
-      switches: switches
-    }
+    {aliases, switches, strict}
   end
 
   defp validate_option(value, kinds) do
-    {invalid?, value} =
-      cond do
-        :invalid in kinds ->
-          {true, value}
-        :boolean in kinds ->
-          case value do
-            t when t in [true, "true"] -> {false, true}
-            f when f in [false, "false"] -> {false, false}
-            _ -> {true, value}
-          end
-        :count in kinds ->
-          case value do
-            1 -> {false, value}
-            _ -> {true, value}
-          end
-        :integer in kinds ->
-          case Integer.parse(value) do
-            {value, ""} -> {false, value}
-            _ -> {true, value}
-          end
-        :float in kinds ->
-          case Float.parse(value) do
-            {value, ""} -> {false, value}
-            _ -> {true, value}
-          end
-        true ->
-          {false, value}
-      end
+    {is_invalid, value} = cond do
+      :invalid in kinds ->
+        {true, value}
+      :boolean in kinds ->
+        case value do
+          t when t in [true, "true"] -> {nil, true}
+          f when f in [false, "false"] -> {nil, false}
+          _ -> {true, value}
+        end
+      :integer in kinds ->
+        case Integer.parse(value) do
+          {value, ""} -> {nil, value}
+          _ -> {true, value}
+        end
+      :float in kinds ->
+        case Float.parse(value) do
+          {value, ""} -> {nil, value}
+          _ -> {true, value}
+        end
+      true ->
+        {nil, value}
+    end
 
-    if invalid? do
+    if is_invalid do
       :invalid
     else
       {:ok, value}
     end
   end
 
-  defp store_option(dict, option, value, kinds) do
+  defp do_store_option(dict, option, value, kinds) do
     cond do
-      :count in kinds ->
-        Keyword.update(dict, option, value, & &1 + 1)
       :keep in kinds ->
-        [{option, value} | dict]
+        [{option, value}|dict]
       true ->
-        [{option, value} | Keyword.delete(dict, option)]
+        [{option, value}|Keyword.delete(dict, option)]
     end
   end
 
-  defp tag_option("no-" <> option = original, %{switches: switches, allow_nonexistent_atoms?: allow_nonexistent_atoms?}) do
-    cond do
-      (negated = get_option_key(option, allow_nonexistent_atoms?)) && :boolean in List.wrap(switches[negated]) ->
-        {:negated, negated}
-      option_key = get_option_key(original, allow_nonexistent_atoms?) ->
-        {:default, option_key}
-      true ->
-        :unknown
-    end
+  defp tag_option(<<?-, option :: binary>>, switches, _aliases) do
+    get_negated(option, switches)
   end
 
-  defp tag_option(option, %{allow_nonexistent_atoms?: allow_nonexistent_atoms?}) do
-    if option_key = get_option_key(option, allow_nonexistent_atoms?) do
-      {:default, option_key}
+  defp tag_option(option, _switches, aliases) when is_binary(option) do
+    opt = get_option(option)
+    if alias = aliases[opt] do
+      {:default, alias}
     else
       :unknown
     end
   end
 
-  defp tag_oneletter_alias(alias, %{aliases: aliases, allow_nonexistent_atoms?: allow_nonexistent_atoms?}) when is_binary(alias) do
-    if option_key = aliases[to_existing_key(alias, allow_nonexistent_atoms?)] do
-      {:default, option_key}
-    else
-      :unknown
-    end
-  end
-
-  defp expand_multiletter_alias(letters, value) when is_binary(letters) do
-    {last, expanded} =
-      letters
-      |> String.codepoints()
-      |> Enum.map(&("-" <> &1))
-      |> List.pop_at(-1)
-    expanded ++ [last <> if(value, do: "=" <> value, else: "")]
-  end
-
   defp option_defined?(:unknown, _switches) do
     false
   end
@@ -660,33 +415,30 @@ defmodule OptionParser do
     {option, List.wrap(switches[option]), value}
   end
 
-  defp normalize_value(nil, kinds, t, strict?) do
+  defp normalize_value(nil, kinds, t, strict) do
+    nil_or_true = if strict, do: nil, else: true
     cond do
       :boolean in kinds ->
         {true, kinds, t}
-      :count in kinds ->
-        {1, kinds, t}
       value_in_tail?(t) ->
-        [h | t] = t
+        [h|t] = t
         {h, kinds, t}
-      kinds == [] and strict? ->
-        {nil, kinds, t}
       kinds == [] ->
-        {true, kinds, t}
+        {nil_or_true, kinds, t}
       true ->
         {nil, [:invalid], t}
     end
   end
 
-  defp normalize_value(value, kinds, t, _strict?) do
+  defp normalize_value(value, kinds, t, _) do
     {value, kinds, t}
   end
 
-  defp value_in_tail?(["-" | _]),        do: true
-  defp value_in_tail?(["- " <> _ | _]),  do: true
-  defp value_in_tail?(["-" <> arg | _]), do: negative_number?("-" <> arg)
-  defp value_in_tail?([]),               do: false
-  defp value_in_tail?(_),                do: true
+  defp value_in_tail?(["-"|_]),       do: true
+  defp value_in_tail?(["- " <> _|_]), do: true
+  defp value_in_tail?(["-" <> _|_]),  do: false
+  defp value_in_tail?([]),            do: false
+  defp value_in_tail?(_),             do: true
 
   defp split_option(option) do
     case :binary.split(option, "=") do
@@ -695,66 +447,40 @@ defmodule OptionParser do
     end
   end
 
-  defp to_underscore(option),
-    do: to_underscore(option, <<>>)
-  defp to_underscore("_" <> _rest, _acc),
-    do: nil
+  defp to_underscore(option), do: to_underscore(option, <<>>)
+
+  defp to_underscore("_" <> _rest, _acc), do: nil
+
   defp to_underscore("-" <> rest, acc),
     do: to_underscore(rest, acc <> "_")
+
   defp to_underscore(<<c>> <> rest, acc),
     do: to_underscore(rest, <<acc::binary, c>>)
-  defp to_underscore(<<>>, acc),
-    do: acc
 
-  defp get_option_key(option, allow_nonexistent_atoms?) do
-    if string = to_underscore(option) do
-      to_existing_key(string, allow_nonexistent_atoms?)
+  defp to_underscore(<<>>, acc), do: acc
+
+  defp get_option(option) do
+    if str = to_underscore(option) do
+      String.to_atom(str)
     end
   end
 
-  defp to_existing_key(option, true),
-    do: String.to_atom(option)
-  defp to_existing_key(option, false) do
-    try do
-      String.to_existing_atom(option)
-    rescue
-      ArgumentError -> nil
+  defp get_negated("no-" <> rest = original, switches) do
+    cond do
+      (negated = get_option(rest)) && :boolean in List.wrap(switches[negated]) ->
+        {:negated, negated}
+      option = get_option(original) ->
+        {:default, option}
+      true ->
+        :unknown
     end
   end
 
-  defp negative_number?(arg) do
-    match?({_, ""}, Float.parse(arg))
-  end
-
-  defp format_errors([_ | _] = errors, opts) do
-    types = opts[:switches] || opts[:strict]
-    error_count = length(errors)
-    error = if error_count == 1, do: "error", else: "errors"
-    "#{error_count} #{error} found!\n" <>
-      Enum.map_join(errors, "\n", &format_error(&1, opts, types))
-  end
-
-  defp format_error({option, nil}, opts, types) do
-    if type = get_type(option, opts, types) do
-      "#{option} : Missing argument of type #{type}"
+  defp get_negated(rest, _switches) do
+    if option = get_option(rest) do
+      {:default, option}
     else
-      "#{option} : Unknown option"
-    end
-  end
-
-  defp format_error({option, value}, opts, types) do
-    type = get_type(option, opts, types)
-    "#{option} : Expected type #{type}, got #{inspect value}"
-  end
-
-  defp get_type(option, opts, types) do
-    allow_nonexistent_atoms? = opts[:allow_nonexistent_atoms] || false
-    key = option |> String.trim_leading("-") |> get_option_key(allow_nonexistent_atoms?)
-
-    if option_key = opts[:aliases][key] do
-      types[option_key]
-    else
-      types[key]
+      :unknown
     end
   end
 end

lib/elixir/lib/path.ex

@@ -3,24 +3,23 @@ defmodule Path do
   This module provides conveniences for manipulating or
   retrieving file system paths.
 
-  The functions in this module may receive a chardata as
+  The functions in this module may receive a char data as
   argument (i.e. a string or a list of characters / string)
   and will always return a string (encoded in UTF-8).
 
   The majority of the functions in this module do not
   interact with the file system, except for a few functions
-  that require it (like `wildcard/2` and `expand/1`).
+  that require it (like `wildcard/1` and `expand/1`).
   """
 
+  alias :filename, as: FN
   @type t :: :unicode.chardata()
 
   @doc """
   Converts the given path to an absolute one. Unlike
   `expand/1`, no attempt is made to resolve `..`, `.` or `~`.
 
-  ## Examples
-
-  ### Unix
+  ## Unix examples
 
       Path.absname("foo")
       #=> "/usr/local/foo"
@@ -28,12 +27,12 @@ defmodule Path do
       Path.absname("../x")
       #=> "/usr/local/../x"
 
-  ### Windows
+  ## Windows
 
       Path.absname("foo").
-      #=> "D:/usr/local/foo"
+      "D:/usr/local/foo"
       Path.absname("../x").
-      #=> "D:/usr/local/../x"
+      "D:/usr/local/../x"
 
   """
   @spec absname(t) :: binary
@@ -42,10 +41,8 @@ defmodule Path do
   end
 
   @doc """
-  Builds a path from `relative_to` to `path`.
-
-  If `path` is already an absolute path, `relative_to` is ignored. See also
-  `relative_to/2`.
+  Builds a path from `relative_to` to `path`. If `path` is already
+  an absolute path, `relative_to` is ignored. See also `relative_to/2`.
 
   Unlike `expand/2`, no attempt is made to
   resolve `..`, `.` or `~`.
@@ -72,15 +69,15 @@ defmodule Path do
   end
 
   # Absolute path on current drive
-  defp absname_vr(["/" | rest], [volume | _], _relative),
-    do: absname_join([volume | rest])
+  defp absname_vr(["/"|rest], [volume|_], _relative),
+    do: absname_join([volume|rest])
 
   # Relative to current directory on current drive.
-  defp absname_vr([<<x, ?:>> | rest], [<<x, _::binary>> | _], relative),
+  defp absname_vr([<<x, ?:>>|rest], [<<x, _ :: binary>>|_], relative),
     do: absname(absname_join(rest), relative)
 
   # Relative to current directory on another drive.
-  defp absname_vr([<<x, ?:>> | name], _, _relative) do
+  defp absname_vr([<<x, ?:>>|name], _, _relative) do
     cwd =
       case :file.get_cwd([x, ?:]) do
         {:ok, dir}  -> IO.chardata_to_string(dir)
@@ -90,8 +87,8 @@ defmodule Path do
   end
 
   # Joins a list
-  defp absname_join([name1, name2 | rest]), do:
-    absname_join([absname_join(name1, name2) | rest])
+  defp absname_join([name1, name2|rest]), do:
+    absname_join([absname_join(name1, name2)|rest])
   defp absname_join([name]), do:
     do_absname_join(IO.chardata_to_string(name), <<>>, [], major_os_type())
 
@@ -99,32 +96,32 @@ defmodule Path do
   defp absname_join(left, right),
     do: do_absname_join(IO.chardata_to_string(left), relative(right), [], major_os_type())
 
-  defp do_absname_join(<<uc_letter, ?:, rest::binary>>, relativename, [], :win32) when uc_letter in ?A..?Z, do:
-    do_absname_join(rest, relativename, [?:, uc_letter + ?a - ?A], :win32)
-  defp do_absname_join(<<?\\, rest::binary>>, relativename, result, :win32), do:
-    do_absname_join(<<?/, rest::binary>>, relativename, result, :win32)
-  defp do_absname_join(<<?/, rest::binary>>, relativename, [?., ?/ | result], os_type), do:
-    do_absname_join(rest, relativename, [?/ | result], os_type)
-  defp do_absname_join(<<?/, rest::binary>>, relativename, [?/ | result], os_type), do:
-    do_absname_join(rest, relativename, [?/ | result], os_type)
+  defp do_absname_join(<<uc_letter, ?:, rest :: binary>>, relativename, [], :win32) when uc_letter in ?A..?Z, do:
+    do_absname_join(rest, relativename, [?:, uc_letter+?a-?A], :win32)
+  defp do_absname_join(<<?\\, rest :: binary>>, relativename, result, :win32), do:
+    do_absname_join(<<?/, rest :: binary>>, relativename, result, :win32)
+  defp do_absname_join(<<?/, rest :: binary>>, relativename, [?., ?/|result], os_type), do:
+    do_absname_join(rest, relativename, [?/|result], os_type)
+  defp do_absname_join(<<?/, rest :: binary>>, relativename, [?/|result], os_type), do:
+    do_absname_join(rest, relativename, [?/|result], os_type)
   defp do_absname_join(<<>>, <<>>, result, os_type), do:
-    IO.iodata_to_binary(reverse_maybe_remove_dir_sep(result, os_type))
-  defp do_absname_join(<<>>, relativename, [?: | rest], :win32), do:
-    do_absname_join(relativename, <<>>, [?: | rest], :win32)
-  defp do_absname_join(<<>>, relativename, [?/ | result], os_type), do:
-    do_absname_join(relativename, <<>>, [?/ | result], os_type)
+    IO.iodata_to_binary(reverse_maybe_remove_dirsep(result, os_type))
+  defp do_absname_join(<<>>, relativename, [?:|rest], :win32), do:
+    do_absname_join(relativename, <<>>, [?:|rest], :win32)
+  defp do_absname_join(<<>>, relativename, [?/|result], os_type), do:
+    do_absname_join(relativename, <<>>, [?/|result], os_type)
   defp do_absname_join(<<>>, relativename, result, os_type), do:
-    do_absname_join(relativename, <<>>, [?/ | result], os_type)
-  defp do_absname_join(<<char, rest::binary>>, relativename, result, os_type), do:
-    do_absname_join(rest, relativename, [char | result], os_type)
+    do_absname_join(relativename, <<>>, [?/|result], os_type)
+  defp do_absname_join(<<char, rest :: binary>>, relativename, result, os_type), do:
+    do_absname_join(rest, relativename, [char|result], os_type)
 
-  defp reverse_maybe_remove_dir_sep([?/, ?:, letter], :win32), do:
+  defp reverse_maybe_remove_dirsep([?/, ?:, letter], :win32), do:
     [letter, ?:, ?/]
-  defp reverse_maybe_remove_dir_sep([?/], _), do:
+  defp reverse_maybe_remove_dirsep([?/], _), do:
     [?/]
-  defp reverse_maybe_remove_dir_sep([?/ | name], _), do:
+  defp reverse_maybe_remove_dirsep([?/|name], _), do:
     :lists.reverse(name)
-  defp reverse_maybe_remove_dir_sep(name, _), do:
+  defp reverse_maybe_remove_dirsep(name, _), do:
     :lists.reverse(name)
 
   @doc """
@@ -134,7 +131,7 @@ defmodule Path do
   ## Examples
 
       Path.expand("/foo/bar/../bar")
-      #=> "/foo/bar"
+      "/foo/bar"
 
   """
   @spec expand(t) :: binary
@@ -144,11 +141,10 @@ defmodule Path do
 
   @doc """
   Expands the path relative to the path given as the second argument
-  expanding any `.` and `..` characters.
+  expanding any `.` and `..` characters. If the path is already an
+  absolute path, `relative_to` is ignored.
 
-  If the path is already an absolute path, `relative_to` is ignored.
-
-  Note that this function treats a `path` with a leading `~` as
+  Note, that this function treats `path` with a leading `~` as
   an absolute one.
 
   The second argument is first expanded to an absolute path.
@@ -173,9 +169,7 @@ defmodule Path do
   @doc """
   Returns the path type.
 
-  ## Examples
-
-  ### Unix
+  ## Unix examples
 
       Path.type("/")                #=> :absolute
       Path.type("/usr/local/bin")   #=> :absolute
@@ -183,7 +177,7 @@ defmodule Path do
       Path.type("../usr/local/bin") #=> :relative
       Path.type("~/file")           #=> :relative
 
-  ### Windows
+  ## Windows examples
 
       Path.type("D:/usr/local/bin") #=> :absolute
       Path.type("usr/local/bin")    #=> :relative
@@ -192,24 +186,20 @@ defmodule Path do
 
   """
   @spec type(t) :: :absolute | :relative | :volumerelative
-  def type(name)
-      when is_list(name)
-      when is_binary(name) do
-    pathtype(name, major_os_type()) |> elem(0)
+  def type(name) when is_list(name) or is_binary(name) do
+    pathtype(name, major_os_type) |> elem(0)
   end
 
   @doc """
   Forces the path to be a relative path.
 
-  ## Examples
-
-  ### Unix
+  ## Unix examples
 
       Path.relative("/usr/local/bin")   #=> "usr/local/bin"
       Path.relative("usr/local/bin")    #=> "usr/local/bin"
       Path.relative("../usr/local/bin") #=> "../usr/local/bin"
 
-  ### Windows
+  ## Windows examples
 
       Path.relative("D:/usr/local/bin") #=> "usr/local/bin"
       Path.relative("usr/local/bin")    #=> "usr/local/bin"
@@ -235,52 +225,49 @@ defmodule Path do
     end
   end
 
-  defp unix_pathtype(path) when path in ["/", '/'],
-    do: {:absolute, "."}
-  defp unix_pathtype(<<?/, relative::binary>>),
-    do: {:absolute, relative}
-  defp unix_pathtype([?/ | relative]),
-    do: {:absolute, relative}
-  defp unix_pathtype([list | rest]) when is_list(list),
-    do: unix_pathtype(list ++ rest)
-  defp unix_pathtype(relative),
-    do: {:relative, relative}
+  defp unix_pathtype(<<?/, relative :: binary>>), do:
+    {:absolute, relative}
+  defp unix_pathtype([?/|relative]), do:
+    {:absolute, relative}
+  defp unix_pathtype([list|rest]) when is_list(list), do:
+    unix_pathtype(list ++ rest)
+  defp unix_pathtype(relative), do:
+    {:relative, relative}
 
   @slash [?/, ?\\]
 
-  defp win32_pathtype([list | rest]) when is_list(list),
-    do: win32_pathtype(list ++ rest)
-  defp win32_pathtype([char, list | rest]) when is_list(list),
-    do: win32_pathtype([char | list ++ rest])
-  defp win32_pathtype(<<c1, c2, relative::binary>>) when c1 in @slash and c2 in @slash,
-    do: {:absolute, relative}
-  defp win32_pathtype(<<char, relative::binary>>) when char in @slash,
-    do: {:volumerelative, relative}
-  defp win32_pathtype(<<_letter, ?:, char, relative::binary>>) when char in @slash,
-    do: {:absolute, relative}
-  defp win32_pathtype(<<_letter, ?:, relative::binary>>),
-    do: {:volumerelative, relative}
+  defp win32_pathtype([list|rest]) when is_list(list), do:
+    win32_pathtype(list++rest)
+  defp win32_pathtype([char, list|rest]) when is_list(list), do:
+    win32_pathtype([char|list++rest])
+  defp win32_pathtype(<<c1, c2, relative :: binary>>) when c1 in @slash and c2 in @slash, do:
+    {:absolute, relative}
+  defp win32_pathtype(<<c, relative :: binary>>) when c in @slash, do:
+    {:volumerelative, relative}
+  defp win32_pathtype(<<_letter, ?:, c, relative :: binary>>) when c in @slash, do:
+    {:absolute, relative}
+  defp win32_pathtype(<<_letter, ?:, relative :: binary>>), do:
+    {:volumerelative, relative}
 
-  defp win32_pathtype([c1, c2 | relative]) when c1 in @slash and c2 in @slash,
-    do: {:absolute, relative}
-  defp win32_pathtype([char | relative]) when char in @slash,
-    do: {:volumerelative, relative}
-  defp win32_pathtype([c1, c2, list | rest]) when is_list(list),
-    do: win32_pathtype([c1, c2 | list ++ rest])
-  defp win32_pathtype([_letter, ?:, char | relative]) when char in @slash,
-    do: {:absolute, relative}
-  defp win32_pathtype([_letter, ?: | relative]),
-    do: {:volumerelative, relative}
-  defp win32_pathtype(relative),
-    do: {:relative, relative}
+  defp win32_pathtype([c1, c2 | relative]) when c1 in @slash and c2 in @slash, do:
+    {:absolute, relative}
+  defp win32_pathtype([c | relative]) when c in @slash, do:
+    {:volumerelative, relative}
+  defp win32_pathtype([c1, c2, list|rest]) when is_list(list), do:
+    win32_pathtype([c1, c2|list++rest])
+  defp win32_pathtype([_letter, ?:, c | relative]) when c in @slash, do:
+    {:absolute, relative}
+  defp win32_pathtype([_letter, ?: | relative]), do:
+    {:volumerelative, relative}
+  defp win32_pathtype(relative), do:
+    {:relative, relative}
 
   @doc """
   Returns the given `path` relative to the given `from` path.
-
-  In other words, this function tries to strip the `from` prefix from `path`.
+  In other words, it tries to strip the `from` prefix from `path`.
 
   This function does not query the file system, so it assumes
-  no symlinks between the paths.
+  no symlinks in between the paths.
 
   In case a direct relative path cannot be found, it returns
   the original path.
@@ -303,11 +290,11 @@ defmodule Path do
     relative_to(split(path), split(from), path)
   end
 
-  defp relative_to([h | t1], [h | t2], original) do
+  defp relative_to([h|t1], [h|t2], original) do
     relative_to(t1, t2, original)
   end
 
-  defp relative_to([_ | _] = l1, [], _original) do
+  defp relative_to([_|_] = l1, [], _original) do
     join(l1)
   end
 
@@ -317,10 +304,8 @@ defmodule Path do
 
   @doc """
   Convenience to get the path relative to the current working
-  directory.
-
-  If, for some reason, the current working directory
-  cannot be retrieved, this function returns the given `path`.
+  directory. If, for some reason, the current working directory
+  cannot be retrieved, returns the full path.
   """
   @spec relative_to_cwd(t) :: binary
   def relative_to_cwd(path) do
@@ -348,15 +333,13 @@ defmodule Path do
   """
   @spec basename(t) :: binary
   def basename(path) do
-    :filename.basename(IO.chardata_to_string(path))
+    FN.basename(IO.chardata_to_string(path))
   end
 
   @doc """
   Returns the last component of `path` with the `extension`
-  stripped.
-
-  This function should be used to remove a specific
-  extension which may or may not be there.
+  stripped. This function should be used to remove a specific
+  extension which may, or may not, be there.
 
   ## Examples
 
@@ -372,7 +355,7 @@ defmodule Path do
   """
   @spec basename(t, t) :: binary
   def basename(path, extension) do
-    :filename.basename(IO.chardata_to_string(path), IO.chardata_to_string(extension))
+    FN.basename(IO.chardata_to_string(path), IO.chardata_to_string(extension))
   end
 
   @doc """
@@ -380,19 +363,15 @@ defmodule Path do
 
   ## Examples
 
-      iex> Path.dirname("/foo/bar.ex")
-      "/foo"
-
-      iex> Path.dirname("/foo/bar/baz.ex")
-      "/foo/bar"
-
-      iex> Path.dirname("/foo/bar/")
-      "/foo/bar"
+      Path.dirname("/foo/bar.ex")
+      #=> "/foo"
+      Path.dirname("/foo/bar/baz.ex")
+      #=> "/foo/bar"
 
   """
   @spec dirname(t) :: binary
   def dirname(path) do
-    :filename.dirname(IO.chardata_to_string(path))
+    FN.dirname(IO.chardata_to_string(path))
   end
 
   @doc """
@@ -409,7 +388,7 @@ defmodule Path do
   """
   @spec extname(t) :: binary
   def extname(path) do
-    :filename.extension(IO.chardata_to_string(path))
+    FN.extension(IO.chardata_to_string(path))
   end
 
   @doc """
@@ -426,14 +405,12 @@ defmodule Path do
   """
   @spec rootname(t) :: binary
   def rootname(path) do
-    :filename.rootname(IO.chardata_to_string(path))
+    FN.rootname(IO.chardata_to_string(path))
   end
 
   @doc """
-  Returns the `path` with the `extension` stripped.
-
-  This function should be used to remove a specific extension which may
-  or may not be there.
+  Returns the `path` with the `extension` stripped. This function should be used to
+  remove a specific extension which might, or might not, be there.
 
   ## Examples
 
@@ -446,14 +423,14 @@ defmodule Path do
   """
   @spec rootname(t, t) :: binary
   def rootname(path, extension) do
-    :filename.rootname(IO.chardata_to_string(path), IO.chardata_to_string(extension))
+    FN.rootname(IO.chardata_to_string(path), IO.chardata_to_string(extension))
   end
 
   @doc """
-  Joins a list of paths.
+  Joins a list of strings.
 
-  This function should be used to convert a list of paths to a path.
-  Note that any trailing slash is removed when joining.
+  This function should be used to convert a list of strings to a path.
+  Note that any trailing slash is removed on join.
 
   ## Examples
 
@@ -467,41 +444,37 @@ defmodule Path do
       "/foo/bar"
 
   """
-  @spec join(nonempty_list(t)) :: binary
-  def join([name1, name2 | rest]), do:
-    join([join(name1, name2) | rest])
+  @spec join([t]) :: binary
+  def join([name1, name2|rest]), do:
+    join([join(name1, name2)|rest])
   def join([name]), do:
-    IO.chardata_to_string(name)
+    name
 
   @doc """
   Joins two paths.
 
   The right path will always be expanded to its relative format
-  and any trailing slash will be removed when joining.
+  and any trailing slash is removed on join.
 
   ## Examples
 
       iex> Path.join("foo", "bar")
       "foo/bar"
 
-      iex> Path.join("/foo", "/bar/")
-      "/foo/bar"
-
   """
   @spec join(t, t) :: binary
   def join(left, right) do
     left    = IO.chardata_to_string(left)
     os_type = major_os_type()
-    do_join(left, right, os_type) |> remove_dir_sep(os_type)
+    do_join(left, right, os_type) |> remove_dirsep(os_type)
   end
 
   defp do_join("", right, os_type),   do: relative(right, os_type)
-  defp do_join("/", right, os_type),  do: "/" <> relative(right, os_type)
-  defp do_join(left, right, os_type), do: remove_dir_sep(left, os_type) <> "/" <> relative(right, os_type)
+  defp do_join(left, "", _os_type),   do: left
+  defp do_join(left, right, os_type), do: remove_dirsep(left, os_type) <> "/" <> relative(right, os_type)
 
-  defp remove_dir_sep("", _os_type), do: ""
-  defp remove_dir_sep("/", _os_type), do: "/"
-  defp remove_dir_sep(bin, os_type) do
+  defp remove_dirsep("", _os_type), do: ""
+  defp remove_dirsep(bin, os_type) do
     last = :binary.last(bin)
     if last == ?/ or (last == ?\\ and os_type == :win32) do
       binary_part(bin, 0, byte_size(bin) - 1)
@@ -521,14 +494,14 @@ defmodule Path do
 
   ## Examples
 
-      iex> Path.split("")
-      []
+       iex> Path.split("")
+       []
 
-      iex> Path.split("foo")
-      ["foo"]
+       iex> Path.split("foo")
+       ["foo"]
 
-      iex> Path.split("/foo/bar")
-      ["/", "foo", "bar"]
+       iex> Path.split("/foo/bar")
+       ["/", "foo", "bar"]
 
   """
   @spec split(t) :: [binary]
@@ -537,7 +510,7 @@ defmodule Path do
   def split(""), do: []
 
   def split(path) do
-    :filename.split(IO.chardata_to_string(path))
+    FN.split(IO.chardata_to_string(path))
   end
 
   defmodule Wildcard do
@@ -547,8 +520,13 @@ defmodule Path do
       call({:read_link_info, file})
     end
 
+    # For compatibility with buggy Erlang 17.1.
+    def read_file_info(file) do
+      call({:read_link_info, file})
+    end
+
     def list_dir(dir) do
-      case call({:list_dir, dir}) do
+      case call({:list_dir, dir})  do
         {:ok, files} ->
           {:ok, for(file <- files, hd(file) != ?., do: file)}
         other ->
@@ -567,8 +545,7 @@ defmodule Path do
   end
 
   @doc """
-  Traverses paths according to the given `glob` expression and returns a
-  list of matches.
+  Traverses paths according to the given `glob` expression.
 
   The wildcard looks like an ordinary path, except that certain
   "wildcard characters" are interpreted in a special way. The
@@ -583,25 +560,21 @@ defmodule Path do
       files and zero or more directories and subdirectories
 
     * `[char1,char2,...]` - matches any of the characters listed; two
-      characters separated by a hyphen will match a range of characters.
-      Do not add spaces before and after the comma as it would then match
-      paths containing the space character itself.
+      characters separated by a hyphen will match a range of characters
 
     * `{item1,item2,...}` - matches one of the alternatives
-      Do not add spaces before and after the comma as it would then match
-      paths containing the space character itself.
 
   Other characters represent themselves. Only paths that have
   exactly the same character in the same position will match. Note
-  that matching is case-sensitive: `"a"` will not match `"A"`.
+  that matching is case-sensitive; i.e. "a" will not match "A".
 
   By default, the patterns `*` and `?` do not match files starting
-  with a dot `.` unless `match_dot: true` is given in `opts`.
+  with a dot `.` unless `match_dot: true` is given.
 
   ## Examples
 
   Imagine you have a directory called `projects` with three Elixir projects
-  inside of it: `elixir`, `ex_doc`, and `plug`. You can find all `.beam` files
+  inside of it: `elixir`, `ex_doc` and `dynamo`. You can find all `.beam` files
   inside the `ebin` directory of each project as follows:
 
       Path.wildcard("projects/*/ebin/**/*.beam")
@@ -611,23 +584,21 @@ defmodule Path do
       Path.wildcard("projects/*/ebin/**/*.{beam,app}")
 
   """
-  @spec wildcard(t, keyword) :: [binary]
+  @spec wildcard(t) :: [binary]
   def wildcard(glob, opts \\ []) do
     mod = if Keyword.get(opts, :match_dot), do: :file, else: Path.Wildcard
     glob
-    |> chardata_to_list!()
+    |> chardata_to_list()
     |> :filelib.wildcard(mod)
     |> Enum.map(&IO.chardata_to_string/1)
   end
 
-  defp chardata_to_list!(chardata) do
+  # expand_dot the given path by expanding "..", "." and "~".
+
+  defp chardata_to_list(chardata) do
     case :unicode.characters_to_list(chardata) do
       result when is_list(result) ->
-        if 0 in result do
-          raise ArgumentError, "cannot execute Path.wildcard/2 for path with null byte, got: #{inspect chardata}"
-        else
-          result
-        end
+        result
 
       {:error, encoded, rest} ->
         raise UnicodeConversionError, encoded: encoded, rest: rest, kind: :invalid
@@ -647,7 +618,7 @@ defmodule Path do
   defp resolve_home(""), do: System.user_home!
 
   defp resolve_home(rest) do
-    case {rest, major_os_type()} do
+    case {rest, major_os_type} do
       {"\\" <> _, :win32} ->
         System.user_home! <> rest
       {"/" <> _, _} ->
@@ -656,30 +627,32 @@ defmodule Path do
     end
   end
 
-  # expand_dot the given path by expanding "..", "." and "~".
-
-  defp expand_dot(<<"/", rest::binary>>),
-    do: "/" <> do_expand_dot(rest)
-  defp expand_dot(<<letter, ":/", rest::binary>>) when letter in ?a..?z,
-    do: <<letter, ":/">> <> do_expand_dot(rest)
+  defp expand_dot(<<"/../", rest::binary>>),
+    do: expand_dot("/" <> rest)
+  defp expand_dot(<<letter, ":/../", rest::binary>>) when letter in ?a..?z,
+    do: expand_dot(<<letter, ":/", rest::binary>>)
+  defp expand_dot("/.."),
+    do: "/"
+  defp expand_dot(<<letter, ":/..">>) when letter in ?a..?z,
+    do: expand_dot(<<letter, ":/">>)
   defp expand_dot(path),
-    do: do_expand_dot(path)
+    do: expand_dot(:binary.split(path, "/", [:global]), [])
 
-  defp do_expand_dot(path),
-    do: do_expand_dot(:binary.split(path, "/", [:global]), [])
+  defp expand_dot([".."|t], [_, _|acc]) do
+    expand_dot t, acc
+  end
 
-  defp do_expand_dot([".." | t], [_, _ | acc]),
-    do: do_expand_dot(t, acc)
-  defp do_expand_dot([".." | t], []),
-    do: do_expand_dot(t, [])
-  defp do_expand_dot(["." | t], acc),
-    do: do_expand_dot(t, acc)
-  defp do_expand_dot([h | t], acc),
-    do: do_expand_dot(t, ["/", h | acc])
-  defp do_expand_dot([], []),
-    do: ""
-  defp do_expand_dot([], ["/" | acc]),
-    do: IO.iodata_to_binary(:lists.reverse(acc))
+  defp expand_dot(["."|t], acc) do
+    expand_dot t, acc
+  end
+
+  defp expand_dot([h|t], acc) do
+    expand_dot t, ["/", h|acc]
+  end
+
+  defp expand_dot([], ["/"|acc]) do
+    IO.iodata_to_binary(:lists.reverse(acc))
+  end
 
   defp major_os_type do
     :os.type |> elem(0)

lib/elixir/lib/port.ex

@@ -1,270 +1,86 @@
 defmodule Port do
-  @moduledoc ~S"""
-  Functions for interacting with the external world through ports.
-
-  Ports provide a mechanism to start operating system processes external
-  to the Erlang VM and communicate with them via message passing.
-
-  ## Example
-
-      iex> port = Port.open({:spawn, "cat"}, [:binary])
-      iex> send port, {self(), {:command, "hello"}}
-      iex> send port, {self(), {:command, "world"}}
-      iex> flush()
-      {#Port<0.1444>, {:data, "hello"}}
-      {#Port<0.1444>, {:data, "world"}}
-      iex> send port, {self(), :close}
-      :ok
-      iex> flush()
-      {#Port<0.1464>, :closed}
-      :ok
-
-  In the example above, we have created a new port that executes the
-  program `cat`. `cat` is a program available on UNIX systems that
-  receives data from multiple inputs and concatenates them in the output.
-
-  After the port was created, we sent it two commands in the form of
-  messages using `Kernel.send/2`. The first command has the binary payload
-  of "hello" and the second has "world".
-
-  After sending those two messages, we invoked the IEx helper `flush()`,
-  which printed all messages received from the port, in this case we got
-  "hello" and "world" back. Notice the messages are in binary because we
-  passed the `:binary` option when opening the port in `Port.open/2`. Without
-  such option, it would have yielded a list of bytes.
-
-  Once everything was done, we closed the port.
-
-  Elixir provides many conveniences for working with ports and some drawbacks.
-  We will explore those below.
-
-  ## Message and function APIs
-
-  There are two APIs for working with ports. It can be either asynchronous via
-  message passing, as in the example above, or by calling the functions on this
-  module.
-
-  The messages supported by ports and their counterpart function APIs are
-  listed below:
-
-    * `{pid, {:command, binary}}` - sends the given data to the port.
-      See `command/3`.
-
-    * `{pid, :close}` - closes the port. Unless the port is already closed,
-      the port will reply with `{port, :closed}` message once it has flushed
-      its buffers and effectively closed. See `close/1`.
-
-    * `{pid, {:connect, new_pid}}` - sets the `new_pid` as the new owner of
-      the port. Once a port is opened, the port is linked and connected to the
-      caller process and communication to the port only happens through the
-      connected process. This message makes `new_pid` the new connected processes.
-      Unless the port is dead, the port will reply to the old owner with
-      `{port, :connected}`. See `connect/2`.
-
-  On its turn, the port will send the connected process the following messages:
-
-    * `{port, {:data, data}}` - data sent by the port
-    * `{port, :closed}` - reply to the `{pid, :close}` message
-    * `{port, :connected}` - reply to the `{pid, {:connect, new_pid}}` message
-    * `{:EXIT, port, reason}` - exit signals in case the port crashes. If reason
-      is not `:normal`, this message will only be received if the owner process
-      is trapping exits
-
-  ## Open mechanisms
-
-  The port can be opened through four main mechanisms.
-
-  As a short summary, prefer to using the `:spawn` and `:spawn_executable`
-  options mentioned below. The other two options, `:spawn_driver` and `:fd`
-  are for advanced usage within the VM. Also consider using `System.cmd/3`
-  if all you want is to execute a program and retrieve its return value.
-
-  ### spawn
-
-  The `:spawn` tuple receives a binary that is going to be executed as a
-  full invocation. For example, we can use it to invoke "echo hello" directly:
-
-      iex> port = Port.open({:spawn, "echo oops"}, [:binary])
-      iex> flush()
-      {#Port<0.1444>, {:data, "oops\n"}}
-
-  `:spawn` will retrieve the program name from the argument and traverse your
-  OS `$PATH` environment variable looking for a matching program.
-
-  Although the above is handy, it means it is impossible to invoke an executable
-  that has whitespaces on its name or in any of its arguments. For those reasons,
-  most times it is preferrable to execute `:spawn_executable`.
-
-  ### spawn_executable
-
-  Spawn executable is a more restricted and explicit version of spawn. It expects
-  full file paths to the executable you want to execute. If they are in your `$PATH`,
-  they can be retrieved by calling `System.find_executable/1`:
-
-      iex> path = System.find_executable("echo")
-      iex> port = Port.open({:spawn_executable, path}, [:binary, args: ["hello world"]])
-      iex> flush()
-      {#Port<0.1380>, {:data, "hello world\n"}}
-
-  When using `:spawn_executable`, the list of arguments can be passed via
-  the `:args` option as done above. For the full list of options, see the
-  documentation for the Erlang function `:erlang.open_port/2`.
-
-  ### spawn_driver
-
-  Spawn driver is used to start Port Drivers, which are programs written in
-  C that implements a specific communication protocols and are dynamically
-  linked to the Erlang VM. Port drivers are an advanced topic and one of the
-  mechanisms for integrating C code, alongside NIFs. For more information,
-  [please check the Erlang docs](http://erlang.org/doc/reference_manual/ports.html).
-
-  ### fd
-
-  The `:fd` name option allows developers to access `in` and `out` file
-  descriptors used by the Erlang VM. You would use those only if you are
-  reimplementing core part of the Runtime System, such as the `:user` and
-  `:shell` processes.
-
-  ## Zombie processes
-
-  A port can be closed via the `close/1` function or by sending a `{pid, :close}`
-  message. However, if the VM crashes, a long-running program started by the port
-  will have its stdin and stdout channels closed but **it won't be automatically
-  terminated**.
-
-  While most UNIX command line tools will exit once its communication channels
-  are closed, not all command line applications will do so. While we encourage
-  graceful termination by detecting if stdin/stdout has been closed, we do not
-  always have control over how 3rd party software terminates. In those cases,
-  you can wrap the application in a script that checks for stdin. Here is such
-  script in bash:
-
-      #!/bin/sh
-      "$@"
-      pid=$!
-      while read line ; do
-        :
-      done
-      kill -KILL $pid
-
-
-  Now instead of:
-
-      Port.open({:spawn_executable, "/path/to/program"},
-                [args: ["a", "b", "c"]])
-
-  You may invoke:
-
-      Port.open({:spawn_executable, "/path/to/wrapper"},
-                [args: ["/path/to/program", "a", "b", "c"]])
-
+  @moduledoc """
+  Functions related to Erlang ports.
   """
 
-  @type name :: {:spawn, charlist | binary} |
-                {:spawn_driver, charlist | binary} |
-                {:spawn_executable, charlist | atom} |
-                {:fd, non_neg_integer, non_neg_integer}
-
   @doc """
-  Opens a port given a tuple `name` and a list of `options`.
-
-  The module documentation above contains documentation and examples
-  for the supported `name` values, summarized below:
-
-    * `{:spawn, command}` - runs an external program. `command` must contain
-      the program name and optionally a list of arguments separated by space.
-      If passing programs or arguments with space in their name, use the next option.
-    * `{:spawn_executable, filename}` - runs the executable given by the absolute
-      file name `filename`. Arguments can be passed via the `:args` option.
-    * `{:spawn_driver, command}` - spawns so-called port drivers.
-    * `{:fd, fd_in, fd_out}` - accesses file descriptors, `fd_in` and `fd_out`
-      opened by the VM.
-
-  For more information and the list of options, see
-  [`:erlang.open_port/2`](http://www.erlang.org/doc/man/erlang.html#open_port-2).
+  See http://www.erlang.org/doc/man/erlang.html#open_port-2.
 
   Inlined by the compiler.
   """
-  @spec open(name, list) :: port
   def open(name, settings) do
     :erlang.open_port(name, settings)
   end
 
   @doc """
-  Closes the `port`.
-
-  For more information, see [`:erlang.port_close/1`](http://www.erlang.org/doc/man/erlang.html#port_close-1).
+  See http://www.erlang.org/doc/man/erlang.html#port_close-1.
 
   Inlined by the compiler.
   """
-  @spec close(port) :: true
   def close(port) do
     :erlang.port_close(port)
   end
 
   @doc """
-  Sends `data` to the port driver `port`.
-
-  For more information, see [`:erlang.port_command/2`](http://www.erlang.org/doc/man/erlang.html#port_command-2).
+  See http://www.erlang.org/doc/man/erlang.html#port_command-2.
 
   Inlined by the compiler.
   """
-  @spec command(port, iodata, [:force | :nosuspend]) :: boolean
   def command(port, data, options \\ []) do
     :erlang.port_command(port, data, options)
   end
 
   @doc """
-  Associates the `port` identifier with a `pid`.
-
-  For more information, see [`:erlang.port_connect/2`](http://www.erlang.org/doc/man/erlang.html#port_connect-2).
+  See http://www.erlang.org/doc/man/erlang.html#port_connect-2.
 
   Inlined by the compiler.
   """
-  @spec connect(port, pid) :: true
   def connect(port, pid) do
     :erlang.port_connect(port, pid)
   end
 
   @doc """
-  Returns information about the `port` or `nil` if the port is closed.
+  See http://www.erlang.org/doc/man/erlang.html#port_control-3.
 
-  For more information, see [`:erlang.port_info/1`](http://www.erlang.org/doc/man/erlang.html#port_info-1).
+  Inlined by the compiler.
   """
-  def info(port) do
-    nillify :erlang.port_info(port)
+  def control(port, operation, data) do
+    :erlang.port_control(port, operation, data)
+  end
+
+  @doc """
+  See http://www.erlang.org/doc/man/erlang.html#port_call-3.
+
+  Inlined by the compiler.
+  """
+  def call(port, operation, data) do
+    :erlang.port_call(port, operation, data)
   end
 
   @doc """
-  Returns information about the `port` or `nil` if the port is closed.
+  See http://www.erlang.org/doc/man/erlang.html#port_info-1.
 
-  For more information, see [`:erlang.port_info/2`](http://www.erlang.org/doc/man/erlang.html#port_info-2).
+  Inlined by the compiler.
   """
-  @spec info(port, atom) :: {atom, term} | nil
-  def info(port, spec)
-
-  def info(port, :registered_name) do
-    case :erlang.port_info(port, :registered_name) do
-      [] -> {:registered_name, []}
-      other -> nillify(other)
-    end
+  def info(port) do
+    :erlang.port_info(port)
   end
 
+  @doc """
+  See http://www.erlang.org/doc/man/erlang.html#port_info-2.
+
+  Inlined by the compiler.
+  """
   def info(port, item) do
-    nillify :erlang.port_info(port, item)
+    :erlang.port_info(port, item)
   end
 
   @doc """
-  Returns a list of all ports in the current node.
+  See http://www.erlang.org/doc/man/erlang.html#ports-0.
 
   Inlined by the compiler.
   """
-  @spec list :: [port]
   def list do
     :erlang.ports
   end
-
-  @compile {:inline, nillify: 1}
-  defp nillify(:undefined), do: nil
-  defp nillify(other),      do: other
-end
+end

lib/elixir/lib/process.ex

@@ -4,7 +4,7 @@ defmodule Process do
 
   Besides the functions available in this module, the `Kernel` module
   exposes and auto-imports some basic functionality related to processes
-  available through the following functions:
+  available through the functions:
 
     * `Kernel.spawn/1` and `Kernel.spawn/3`
     * `Kernel.spawn_link/1` and `Kernel.spawn_link/3`
@@ -15,31 +15,28 @@ defmodule Process do
   """
 
   @doc """
-  Tells whether the given process is alive.
+  Returns true if the process exists and is alive, that is,
+  is not exiting and has not exited. Otherwise, returns false.
 
-  If the process identified by `pid` is alive (that is, it's not exiting and has
-  not exited yet) than this function returns `true`. Otherwise, it returns
-  `false`.
-
-  `pid` must refer to a process running on the local node.
-
-  Inlined by the compiler.
+  `pid` must refer to a process at the local node.
   """
   @spec alive?(pid) :: boolean
-  defdelegate alive?(pid), to: :erlang, as: :is_process_alive
+  def alive?(pid) do
+    :erlang.is_process_alive(pid)
+  end
 
   @doc """
-  Returns all key-value pairs in the process dictionary.
-
-  Inlined by the compiler.
+  Returns all key-values in the dictionary.
   """
-  @spec get() :: [{term, term}]
-  defdelegate get(), to: :erlang
+  @spec get :: [{term, term}]
+  def get do
+    :erlang.get()
+  end
 
   @doc """
-  Returns the value for the given `key` in the process dictionary,
-  or `default` if `key` is not set.
+  Returns the value for the given `key`.
   """
+  @spec get(term) :: term
   @spec get(term, default :: term) :: term
   def get(key, default \\ nil) do
     case :erlang.get(key) do
@@ -51,35 +48,15 @@ defmodule Process do
   end
 
   @doc """
-  Returns all keys in the process dictionary.
-
-  Inlined by the compiler.
-  """
-  @spec get_keys() :: [term]
-  defdelegate get_keys(), to: :erlang
-
-  @doc """
-  Returns all keys in the process dictionary that have the given `value`.
-
-  Inlined by the compiler.
+  Returns all keys that have the given `value`.
   """
   @spec get_keys(term) :: [term]
-  defdelegate get_keys(value), to: :erlang
+  def get_keys(value) do
+    :erlang.get_keys(value)
+  end
 
   @doc """
-  Stores the given `key`-`value` pair in the process dictionary.
-
-  The return value of this function is the value that was previously stored
-  under `key`, or `nil` in case no value was stored under `key`.
-
-  ## Examples
-
-      # Assuming :locale was not set
-      Process.put(:locale, "en")
-      #=> nil
-      Process.put(:locale, "fr")
-      #=> "en"
-
+  Stores the given key-value in the process dictionary.
   """
   @spec put(term, term) :: term | nil
   def put(key, value) do
@@ -87,19 +64,7 @@ defmodule Process do
   end
 
   @doc """
-  Deletes the given `key` from the process dictionary.
-
-  Returns the value that was under `key` in the process dictionary,
-  or `nil` if `key` was not stored in the process dictionary.
-
-  ## Examples
-
-      Process.put(:comments, ["comment", "other comment"])
-      Process.delete(:comments)
-      #=> ["comment", "other comment"]
-      Process.delete(:comments)
-      #=> nil
-
+  Deletes the given `key` from the dictionary.
   """
   @spec delete(term) :: term | nil
   def delete(key) do
@@ -107,233 +72,84 @@ defmodule Process do
   end
 
   @doc """
-  Sends an exit signal with the given `reason` to `pid`.
+  Sends an exit signal with the given reason to the pid.
 
-  The following behaviour applies if `reason` is any term except `:normal`
-  or `:kill`:
+  The following behaviour applies if reason is any term except `:normal` or `:kill`:
 
-    1. If `pid` is not trapping exits, `pid` will exit with the given
-       `reason`.
+    1. If pid is not trapping exits, pid will exit with the given reason.
 
-    2. If `pid` is trapping exits, the exit signal is transformed into a
-       message `{:EXIT, from, reason}` and delivered to the message queue
-       of `pid`.
+    2. If pid is trapping exits, the exit signal is transformed into a message
+       `{:EXIT, from, reason}` and delivered to the message queue of pid.
 
-  If `reason` is the atom `:normal`, `pid` will not exit (unless `pid` is
-  the calling process, in which case it will exit with the reason `:normal`).
-  If it is trapping exits, the exit signal is transformed into a message
-  `{:EXIT, from, :normal}` and delivered to its message queue.
+    3. If reason is the atom `:normal`, pid will not exit. If it is trapping
+       exits, the exit signal is transformed into a message `{:EXIT, from,
+       :normal}` and delivered to its message queue.
 
-  If `reason` is the atom `:kill`, that is if `Process.exit(pid, :kill)` is called,
-  an untrappable exit signal is sent to `pid` which will unconditionally exit
-  with reason `:killed`.
+    4. If reason is the atom `:kill`, that is if `exit(pid, :kill)` is called,
+       an untrappable exit signal is sent to pid which will unconditionally
+       exit with exit reason `:killed`.
 
   Inlined by the compiler.
 
   ## Examples
 
       Process.exit(pid, :kill)
-      #=> true
 
   """
   @spec exit(pid, term) :: true
-  defdelegate exit(pid, reason), to: :erlang
-
-  @doc """
-  Sleeps the current process for the given `timeout`.
-
-  `timeout` is either the number of milliseconds to sleep as an
-  integer or the atom `:infinity`. When `:infinity` is given,
-  the current process will sleep forever, and not
-  consume or reply to messages.
-
-  **Use this function with extreme care**. For almost all situations
-  where you would use `sleep/1` in Elixir, there is likely a
-  more correct, faster and precise way of achieving the same with
-  message passing.
-
-  For example, if you are waiting for a process to perform some
-  action, it is better to communicate the progress of such action
-  with messages.
-
-  In other words, **do not**:
-
-      Task.start_link fn ->
-        do_something()
-        ...
-      end
-
-      # Wait until work is done
-      Process.sleep(2000)
-
-  But **do**:
-
-      parent = self()
-      Task.start_link fn ->
-        do_something()
-        send parent, :work_is_done
-        ...
-      end
-
-      receive do
-        :work_is_done -> :ok
-      after
-        30_000 -> :timeout # Optional timeout
-      end
-
-  For cases like the one above, `Task.async/1` and `Task.await/2` are
-  preferred.
-
-  Similarly, if you are waiting for a process to terminate,
-  monitor that process instead of sleeping. **Do not**:
-
-      Task.start_link fn ->
-        ...
-      end
-
-      # Wait until task terminates
-      Process.sleep(2000)
-
-  Instead **do**:
-
-      {:ok, pid} =
-        Task.start_link fn ->
-          ...
-        end
-
-      ref = Process.monitor(pid)
-      receive do
-        {:DOWN, ^ref, _, _, _} -> :task_is_down
-      after
-        30_000 -> :timeout # Optional timeout
-      end
-
-  """
-  @spec sleep(timeout) :: :ok
-  def sleep(timeout)
-      when is_integer(timeout) and timeout >= 0
-      when timeout == :infinity do
-    receive after: (timeout -> :ok)
+  def exit(pid, reason) do
+    :erlang.exit(pid, reason)
   end
 
   @doc """
   Sends a message to the given process.
 
-  ## Options
+  If the option `:noconnect` is used and sending the message would require an
+  auto-connection to another node the message is not sent and `:noconnect` is
+  returned.
 
-    * `:noconnect` - when used, if sending the message would require an
-      auto-connection to another node the message is not sent and `:noconnect` is
-      returned.
-
-    * `:nosuspend` - when used, if sending the message would cause the sender to
-      be suspended the message is not sent and `:nosuspend` is returned.
+  If the option `:nosuspend` is used and sending the message would cause the
+  sender to be suspended the message is not sent and `:nosuspend` is returned.
 
   Otherwise the message is sent and `:ok` is returned.
 
   ## Examples
 
-      iex> Process.send({:name, :node_that_does_not_exist}, :hi, [:noconnect])
+      iex> Process.send({:name, :node_does_not_exist}, :hi, [:noconnect])
       :noconnect
 
-  Inlined by the compiler.
   """
-  @spec send(dest, msg, [option]) :: :ok | :noconnect | :nosuspend
-        when dest: pid | port | atom | {atom, node},
-             msg: any,
-             option: :noconnect | :nosuspend
-  defdelegate send(dest, msg, options), to: :erlang
+  @spec send(dest, msg, [option]) ::  result when
+        dest: pid | port | atom | {atom, node},
+        msg: any,
+        option: :noconnect | :nosuspend,
+        result: :ok | :noconnect | :nosuspend
+  def send(dest, msg, options) do
+    :erlang.send(dest, msg, options)
+  end
 
   @doc """
   Sends `msg` to `dest` after `time` milliseconds.
 
-  If `dest` is a PID, it must be the PID of a local process, dead or alive.
+  If `dest` is a pid, it must be the pid of a local process, dead or alive.
   If `dest` is an atom, it must be the name of a registered process
-  which is looked up at the time of delivery. No error is produced if the name does
+  which is looked up at the time of delivery. No error is given if the name does
   not refer to a process.
 
-  This function returns a timer reference, which can be read with `read_timer/1`
-  or canceled with `cancel_timer/1`.
+  This function returns a timer reference, which can be read or canceled with
+  `:erlang.read_timer/1`, `:erlang.start_timer/3` and `:erlang.cancel_timer/1`.
+  Note `time` cannot be greater than `4294967295`.
 
-  The timer will be automatically canceled if the given `dest` is a PID
-  which is not alive or when the given PID exits. Note that timers will not be
+  Finally, the timer will be automatically canceled if the given `dest` is a pid
+  which is not alive or when the given pid exits. Note that timers will not be
   automatically canceled when `dest` is an atom (as the atom resolution is done
   on delivery).
-
-  Inlined by the compiler.
-
-  ## Options
-
-    * `:abs` - (boolean) when `false`, `time` is treated as relative to the
-    current monotonic time. When `true`, `time` is the absolute value of the
-    Erlang monotonic time at which `msg` should be delivered to `dest`.
-    To read more about Erlang monotonic time and other time-related concepts,
-    look at the documentation for the `System` module. Defaults to `false`.
-
-  ## Examples
-
-      timer_ref = Process.send_after(pid, :hi, 1000)
-
   """
-  @spec send_after(pid | atom, term, non_neg_integer, [option]) :: reference
-        when option: {:abs, boolean}
-  def send_after(dest, msg, time, opts \\ []) do
-    :erlang.send_after(time, dest, msg, opts)
+  @spec send_after(pid | atom, term, non_neg_integer) :: reference
+  def send_after(dest, msg, time) do
+    :erlang.send_after(time, dest, msg)
   end
 
-  @doc """
-  Cancels a timer returned by `send_after/3`.
-
-  When the result is an integer, it represents the time in milliseconds
-  left until the timer would have expired.
-
-  When the result is `false`, a timer corresponding to `timer_ref` could not be
-  found. This can happen either because the timer expired, because it has
-  already been canceled, or because `timer_ref` never corresponded to a timer.
-
-  Even if the timer had expired and the message was sent, this function does not
-  tell you if the timeout message has arrived at its destination yet.
-
-  ## Options
-
-    * `:async` - (boolean) when `false`, the request for cancellation is
-      synchronous. When `true`, the request for cancellation is asynchronous,
-      meaning that the request to cancel the timer is issued and `:ok` is
-      returned right away. Defaults to `false`.
-
-    * `:info` - (boolean) whether to return information about the timer being
-      cancelled. When the `:async` option is `false` and `:info` is `true`, then
-      either an integer or `false` (like described above) is returned. If
-      `:async` is `false` and `:info` is `false`, `:ok` is returned. If `:async`
-      is `true` and `:info` is `true`, a message in the form `{:cancel_timer,
-      timer_ref, result}` (where `result` is an integer or `false` like
-      described above) is sent to the caller of this function when the
-      cancellation has been performed. If `:async` is `true` and `:info` is
-      `false`, no message is sent. Defaults to `true`.
-
-  Inlined by the compiler.
-  """
-  @spec cancel_timer(reference, options) :: non_neg_integer | false | :ok
-        when options: [async: boolean, info: boolean]
-  defdelegate cancel_timer(timer_ref, options \\ []), to: :erlang
-
-  @doc """
-  Reads a timer created by `send_after/3`.
-
-  When the result is an integer, it represents the time in milliseconds
-  left until the timer will expire.
-
-  When the result is `false`, a timer corresponding to `timer_ref` could not be
-  found. This can be either because the timer expired, because it has already
-  been canceled, or because `timer_ref` never corresponded to a timer.
-
-  Even if the timer had expired and the message was sent, this function does not
-  tell you if the timeout message has arrived at its destination yet.
-
-  Inlined by the compiler.
-  """
-  @spec read_timer(reference) :: non_neg_integer | false
-  defdelegate read_timer(timer_ref), to: :erlang
-
   @type spawn_opt  :: :link | :monitor | {:priority, :low | :normal | :high} |
                       {:fullsweep_after, non_neg_integer} |
                       {:min_heap_size, non_neg_integer} |
@@ -341,56 +157,48 @@ defmodule Process do
   @type spawn_opts :: [spawn_opt]
 
   @doc """
-  Spawns the given function according to the given options.
-
-  The result depends on the given options. In particular,
-  if `:monitor` is given as an option, it will return a tuple
-  containing the PID and the monitoring reference, otherwise
-  just the spawned process PID.
-
-  More options are available; for the comprehensive list of available options
-  check [`:erlang.spawn_opt/4`](http://www.erlang.org/doc/man/erlang.html#spawn_opt-4).
-
-  Inlined by the compiler.
-  """
-  @spec spawn((() -> any), spawn_opts) :: pid | {pid, reference}
-  defdelegate spawn(fun, opts), to: :erlang, as: :spawn_opt
-
-  @doc """
-  Spawns the given function `fun` from module `mod`, passing the given `args`
+  Spawns the given module and function passing the given args
   according to the given options.
 
   The result depends on the given options. In particular,
   if `:monitor` is given as an option, it will return a tuple
-  containing the PID and the monitoring reference, otherwise
-  just the spawned process PID.
+  containing the pid and the monitoring reference, otherwise
+  just the spawned process pid.
 
   It also accepts extra options, for the list of available options
-  check [`:erlang.spawn_opt/4`](http://www.erlang.org/doc/man/erlang.html#spawn_opt-4).
+  check http://www.erlang.org/doc/man/erlang.html#spawn_opt-4
+
+  Inlined by the compiler.
+  """
+  @spec spawn((() -> any), spawn_opts) :: pid | {pid, reference}
+  def spawn(fun, opts) do
+    :erlang.spawn_opt(fun, opts)
+  end
+
+  @doc """
+  Spawns the given module and function passing the given args
+  according to the given options.
+
+  The result depends on the given options. In particular,
+  if `:monitor` is given as an option, it will return a tuple
+  containing the pid and the monitoring reference, otherwise
+  just the spawned process pid.
+
+  It also accepts extra options, for the list of available options
+  check http://www.erlang.org/doc/man/erlang.html#spawn_opt-4
 
   Inlined by the compiler.
   """
   @spec spawn(module, atom, list, spawn_opts) :: pid | {pid, reference}
-  defdelegate spawn(mod, fun, args, opts), to: :erlang, as: :spawn_opt
+  def spawn(mod, fun, args, opts) do
+    :erlang.spawn_opt(mod, fun, args, opts)
+  end
 
   @doc """
-  Starts monitoring the given `item` from the calling process.
+  The calling process starts monitoring the item given.
+  It returns the monitor reference.
 
-  Once the monitored process dies, a message is delivered to the
-  monitoring process in the shape of:
-
-      {:DOWN, ref, :process, object, reason}
-
-  where:
-
-    * `ref` is a monitor reference returned by this function;
-    * `object` is either a `pid` of the monitored process (if monitoring
-      a PID) or `{name, node}` (if monitoring a remote or local name);
-    * `reason` is the exit reason.
-
-  See [the need for monitoring](http://elixir-lang.org/getting-started/mix-otp/genserver.html#the-need-for-monitoring)
-  for an example.
-  See [`:erlang.monitor/2`](http://www.erlang.org/doc/man/erlang.html#monitor-2) for more info.
+  See http://www.erlang.org/doc/man/erlang.html#monitor-2 for more info.
 
   Inlined by the compiler.
   """
@@ -400,131 +208,91 @@ defmodule Process do
   end
 
   @doc """
-  Demonitors the monitor identifies by the given `reference`.
-
   If `monitor_ref` is a reference which the calling process
-  obtained by calling `monitor/1`, that monitoring is turned off.
+  obtained by calling `monitor/1`, this monitoring is turned off.
   If the monitoring is already turned off, nothing happens.
 
-  See [`:erlang.demonitor/2`](http://www.erlang.org/doc/man/erlang.html#demonitor-2) for more info.
+  See http://www.erlang.org/doc/man/erlang.html#demonitor-2 for more info.
 
   Inlined by the compiler.
   """
+  @spec demonitor(reference) :: true
   @spec demonitor(reference, options :: [:flush | :info]) :: boolean
-  defdelegate demonitor(monitor_ref, options \\ []), to: :erlang
+  def demonitor(monitor_ref, options \\ []) do
+    :erlang.demonitor(monitor_ref, options)
+  end
 
   @doc """
-  Returns a list of PIDs corresponding to all the
+  Returns a list of process identifiers corresponding to all the
   processes currently existing on the local node.
 
-  Note that if a process is exiting, it is considered to exist but not be
-  alive. This means that for such process, `alive?/1` will return `false` but
-  its PID will be part of the list of PIDs returned by this function.
+  Note that a process that is exiting, exists but is not alive, i.e.,
+  `alive?/1` will return `false` for a process that is exiting,
+  but its process identifier will be part of the result returned.
 
-  See [`:erlang.processes/0`](http://www.erlang.org/doc/man/erlang.html#processes-0) for more info.
-
-  Inlined by the compiler.
+  See http://www.erlang.org/doc/man/erlang.html#processes-0 for more info.
   """
-  @spec list() :: [pid]
-  defdelegate list(), to: :erlang, as: :processes
+  @spec list :: [pid]
+  def list do
+    :erlang.processes()
+  end
 
   @doc """
-  Creates a link between the calling process and the given item (process or
-  port).
+  Creates a link between the calling process and another process
+  (or port) `pid`, if there is not such a link already.
 
-  Links are bidirectional. Linked processes can be unlinked by using `unlink/1`.
-
-  If such a link exists already, this function does nothing since there can only
-  be one link between two given processes. If a process tries to create a link
-  to itself, nothing will happen.
-
-  When two processes are linked, each one receives exit signals from the other
-  (see also `exit/2`). Let's assume `pid1` and `pid2` are linked. If `pid2`
-  exits with a reason other than `:normal` (which is also the exit reason used
-  when a process finishes its job) and `pid1` is not trapping exits (see
-  `flag/2`), then `pid1` will exit with the same reason as `pid2` and in turn
-  emit an exit signal to all its other linked processes. The behaviour when
-  `pid1` is trapping exits is described in `exit/2`.
-
-  See [`:erlang.link/1`](http://www.erlang.org/doc/man/erlang.html#link-1) for more info.
+  See http://www.erlang.org/doc/man/erlang.html#link-1 for more info.
 
   Inlined by the compiler.
   """
   @spec link(pid | port) :: true
-  defdelegate link(pid_or_port), to: :erlang
+  def link(pid) do
+    :erlang.link(pid)
+  end
 
   @doc """
+  Removes the link, if there is one, between the calling process and
+  the process or port referred to by `pid`. Returns `true` and does not
+  fail, even if there is no link or `id` does not exist
 
-  Removes the link between the calling process and the given item (process or
-  port).
-
-  If there is no such link, this function does nothing. If `pid_or_port` does
-  not exist, this function does not produce any errors and simply does nothing.
-
-  The return value of this function is always `true`.
-
-  See [`:erlang.unlink/1`](http://www.erlang.org/doc/man/erlang.html#unlink-1) for more info.
+  See http://www.erlang.org/doc/man/erlang.html#unlink-1 for more info.
 
   Inlined by the compiler.
   """
   @spec unlink(pid | port) :: true
-  defdelegate unlink(pid_or_port), to: :erlang
-
-  @doc """
-  Registers the given `pid_or_port` under the given `name`.
-
-  `name` must be an atom and can then be used instead of the
-  PID/port identifier when sending messages with `Kernel.send/2`.
-
-  `register/2` will fail with `ArgumentError` in any of the following cases:
-
-    * the PID/Port is not existing locally and alive
-    * the name is already registered
-    * the `pid_or_port` is already registered under a different `name`
-
-  The following names are reserved and cannot be assigned to
-  processes nor ports:
-
-    * `nil`
-    * `false`
-    * `true`
-    * `:undefined`
-
-  """
-  @spec register(pid | port, atom) :: true
-  def register(pid_or_port, name) when is_atom(name) and name not in [nil, false, true, :undefined] do
-    :erlang.register(name, pid_or_port)
-  catch
-    :error, :badarg when node(pid_or_port) != node()  ->
-      message = "could not register the #{pid_or_port pid_or_port} because it belongs to another node"
-      :erlang.error ArgumentError.exception(message), [pid_or_port, name]
-    :error, :badarg ->
-      message = "could not register the #{pid_or_port pid_or_port} with " <>
-                "name #{inspect name}. Or it is not alive, or the name is already " <>
-                "taken, or it has already been given another name"
-      :erlang.error ArgumentError.exception(message), [pid_or_port, name]
+  def unlink(pid) do
+    :erlang.unlink(pid)
   end
 
-  defp pid_or_port(pid) when is_pid(pid), do: "pid #{inspect pid}"
-  defp pid_or_port(port) when is_port(port), do: "port #{inspect port}"
+  @doc """
+  Associates the name with a pid or a port identifier. `name`, which must
+  be an atom, can be used instead of the pid / port identifier with the
+  `Kernel.send/2` function.
+
+  `Process.register/2` will fail with `ArgumentError` if the pid supplied
+  is no longer alive, (check with `alive?/1`) or if the name is
+  already registered (check with `whereis/1`).
+  """
+  @spec register(pid | port, atom) :: true
+  def register(pid, name) when not name in [nil, false, true] do
+    :erlang.register(name, pid)
+  end
 
   @doc """
-  Removes the registered `name`, associated with a PID
-  or a port identifier.
+  Removes the registered name, associated with a pid or a port identifier.
 
-  Fails with `ArgumentError` if the name is not registered
-  to any PID or port.
-
-  Inlined by the compiler.
+  See http://www.erlang.org/doc/man/erlang.html#unregister-1 for more info.
   """
   @spec unregister(atom) :: true
-  defdelegate unregister(name), to: :erlang
+  def unregister(name) do
+    :erlang.unregister(name)
+  end
 
   @doc """
-  Returns the PID or port identifier registered under `name` or `nil` if the
-  name is not registered.
+  Returns the pid or port identifier with the registered name.
+  Returns `nil` if the name is not registered.
 
-  See [`:erlang.whereis/1`](http://www.erlang.org/doc/man/erlang.html#whereis-1) for more info.
+  See http://www.erlang.org/doc/man/erlang.html#whereis-1 for more info.
   """
   @spec whereis(atom) :: pid | port | nil
   def whereis(name) do
@@ -532,20 +300,16 @@ defmodule Process do
   end
 
   @doc """
-  Returns the PID of the group leader for the calling process.
-
-  Inlined by the compiler.
+  Returns the pid of the group leader for the process which evaluates the function.
   """
-  @spec group_leader() :: pid
-  defdelegate group_leader(), to: :erlang
+  @spec group_leader :: pid
+  def group_leader do
+    :erlang.group_leader
+  end
 
   @doc """
-  Sets the group leader of the given `pid` to `leader`.
-
-  Typically, this is used when a process started from a certain shell should
-  have a group leader other than `:init`.
-
-  Inlined by the compiler.
+  Sets the group leader of `pid` to `leader`. Typically, this is used when a processes
+  started from a certain shell should have a group leader other than `:init`.
   """
   @spec group_leader(pid, leader :: pid) :: true
   def group_leader(pid, leader) do
@@ -554,78 +318,57 @@ defmodule Process do
 
   @doc """
   Returns a list of names which have been registered using `register/2`.
-
-  Inlined by the compiler.
   """
-  @spec registered() :: [atom]
-  defdelegate registered(), to: :erlang
+  @spec registered :: [atom]
+  def registered do
+    :erlang.registered()
+  end
 
-  @typep heap_size :: non_neg_integer |
-                      %{size: non_neg_integer, kill: boolean, error_logger: boolean}
+  @typep process_flag :: :trap_exit | :error_handler | :min_heap_size |
+                         :min_bin_vheap_size | :priority | :save_calls |
+                         :sensitive
+  @doc """
+  Sets certain flags for the process which calls this function.
+  Returns the old value of the flag.
 
-  @typep priority_level :: :low | :normal | :high | :max
+  See http://www.erlang.org/doc/man/erlang.html#process_flag-2 for more info.
+  """
+  @spec flag(process_flag, term) :: term
+  def flag(flag, value) do
+    :erlang.process_flag(flag, value)
+  end
 
   @doc """
-  Sets the given `flag` to `value` for the calling process.
+  Sets certain flags for the process `pid`, in the same manner as `flag/2`.
+  Returns the old value of the flag. The allowed values for `flag` are
+  only a subset of those allowed in `flag/2`, namely: `save_calls`.
 
-  Returns the old value of `flag`.
-
-  See [`:erlang.process_flag/2`](http://www.erlang.org/doc/man/erlang.html#process_flag-2) for more info.
-
-  Note that `flag` values `:max_heap_size` and `:message_queue_data` are only available since OTP 19.
-
-  Inlined by the compiler.
+  See http://www.erlang.org/doc/man/erlang.html#process_flag-3 for more info.
   """
-  @spec flag(:error_handler, module) :: module
-  @spec flag(:max_heap_size, heap_size) :: heap_size
-  @spec flag(:message_queue_data, :erlang.message_queue_data) :: :erlang.message_queue_data
-  @spec flag(:min_bin_vheap_size, non_neg_integer) :: non_neg_integer
-  @spec flag(:min_heap_size, non_neg_integer) :: non_neg_integer
-  @spec flag(:monitor_nodes, term) :: term
-  @spec flag({:monitor_nodes, term()}, term) :: term
-  @spec flag(:priority, priority_level) :: priority_level
-  @spec flag(:save_calls, 0..10_000) :: 0..10_000
-  @spec flag(:sensitive, boolean) :: boolean
-  @spec flag(:trap_exit, boolean) :: boolean
-  defdelegate flag(flag, value), to: :erlang, as: :process_flag
+  @spec flag(pid, :save_calls, non_neg_integer) :: non_neg_integer
+  def flag(pid, flag, value) do
+    :erlang.process_flag(pid, flag, value)
+  end
 
   @doc """
-  Sets the given `flag` to `value` for the given process `pid`.
-
-  Returns the old value of `flag`.
-
-  It raises `ArgumentError` if `pid` is not a local process.
-
-  The allowed values for `flag` are only a subset of those allowed in `flag/2`,
-  namely `:save_calls`.
-
-  See [`:erlang.process_flag/3`](http://www.erlang.org/doc/man/erlang.html#process_flag-3) for more info.
-
-  Inlined by the compiler.
-  """
-  @spec flag(pid, :save_calls, 0..10_000) :: 0..10_000
-  defdelegate flag(pid, flag, value), to: :erlang, as: :process_flag
-
-  @doc """
-  Returns information about the process identified by `pid`, or returns `nil` if the process
+  Returns information about the process identified by `pid` or `nil` if the process
   is not alive.
-
   Use this only for debugging information.
 
-  See [`:erlang.process_info/1`](http://www.erlang.org/doc/man/erlang.html#process_info-1) for more info.
+  See http://www.erlang.org/doc/man/erlang.html#process_info-1 for more info.
   """
-  @spec info(pid) :: keyword
+  @spec info(pid) :: Keyword.t
   def info(pid) do
     nillify :erlang.process_info(pid)
   end
 
   @doc """
-  Returns information about the process identified by `pid`,
-  or returns `nil` if the process is not alive.
+  Returns information about the process identified by `pid`
+  or `nil` if the process is not alive.
 
-  See [`:erlang.process_info/2`](http://www.erlang.org/doc/man/erlang.html#process_info-2) for more info.
+  See http://www.erlang.org/doc/man/erlang.html#process_info-2 for more info.
   """
-  @spec info(pid, atom | [atom]) :: {atom, term} | [{atom, term}]  | nil
+  @spec info(pid, atom) :: {atom, term} | nil
   def info(pid, spec)
 
   def info(pid, :registered_name) do
@@ -636,25 +379,10 @@ defmodule Process do
     end
   end
 
-  def info(pid, spec) when is_atom(spec) or is_list(spec) do
+  def info(pid, spec) when is_atom(spec) do
     nillify :erlang.process_info(pid, spec)
   end
 
-  @doc """
-  Puts the calling process into a "hibernation" state.
-
-  The calling process is put into a waiting state
-  where its memory allocation has been reduced as much as possible,
-  which is useful if the process does not expect to receive any messages
-  in the near future.
-
-  See [`:erlang.hibernate/3`](http://www.erlang.org/doc/man/erlang.html#hibernate-3) for more info.
-
-  Inlined by the compiler.
-  """
-  @spec hibernate(module, atom, list) :: no_return
-  defdelegate hibernate(mod, fun_name, args), to: :erlang
-
   @compile {:inline, nillify: 1}
   defp nillify(:undefined), do: nil
   defp nillify(other),      do: other

lib/elixir/lib/protocol.ex

@@ -19,19 +19,18 @@ defmodule Protocol do
   defmacro def({name, _, args}) when is_atom(name) and is_list(args) do
     arity = length(args)
 
-    type_args = :lists.map(fn _ -> quote(do: term) end,
-                           :lists.seq(2, arity))
+    type_args = for _ <- :lists.seq(2, arity), do: quote(do: term)
     type_args = [quote(do: t) | type_args]
 
-    call_args = :lists.map(fn pos -> Macro.var(String.to_atom("var" <> Integer.to_string(pos)), __MODULE__) end,
-                           :lists.seq(2, arity))
-    call_args = [quote(do: term) | call_args]
+    call_args = for i <- :lists.seq(2, arity),
+                  do: {String.to_atom(<<?x, i + 64>>), [], __MODULE__}
+    call_args = [quote(do: t) | call_args]
 
     quote do
       name  = unquote(name)
       arity = unquote(arity)
 
-      @functions [{name, arity} | @functions]
+      @functions [{name, arity}|@functions]
 
       # Generate a fake definition with the user
       # signature that will be used by docs
@@ -39,7 +38,7 @@ defmodule Protocol do
 
       # Generate the actual implementation
       Kernel.def unquote(name)(unquote_splicing(call_args)) do
-        impl_for!(term).unquote(name)(unquote_splicing(call_args))
+        impl_for!(t).unquote(name)(unquote_splicing(call_args))
       end
 
       # Convert the spec to callback if possible,
@@ -50,13 +49,13 @@ defmodule Protocol do
   end
 
   defmacro def(_) do
-    raise ArgumentError, "invalid arguments for def inside defprotocol"
+    raise ArgumentError, "invalid args for def inside defprotocol"
   end
 
   @doc """
   Checks if the given module is loaded and is protocol.
 
-  Returns `:ok` if so, otherwise raises `ArgumentError`.
+  Returns `:ok` if so, otherwise raises ArgumentError.
   """
   @spec assert_protocol!(module) :: :ok | no_return
   def assert_protocol!(module) do
@@ -70,7 +69,7 @@ defmodule Protocol do
     end
 
     try do
-      module.__protocol__(:module)
+      module.__protocol__(:name)
     rescue
       UndefinedFunctionError ->
         raise ArgumentError, "#{inspect module} is not a protocol" <> extra
@@ -83,7 +82,7 @@ defmodule Protocol do
   Checks if the given module is loaded and is an implementation
   of the given protocol.
 
-  Returns `:ok` if so, otherwise raises `ArgumentError`.
+  Returns `:ok` if so, otherwise raises ArgumentError.
   """
   @spec assert_impl!(module, module) :: :ok | no_return
   def assert_impl!(protocol, base) do
@@ -115,7 +114,7 @@ defmodule Protocol do
   end
 
   @doc """
-  Derives the `protocol` for `module` with the given options.
+  Derive the `protocol` for `module` with the given options.
   """
   defmacro derive(protocol, module, options \\ []) do
     quote do
@@ -127,10 +126,10 @@ defmodule Protocol do
   ## Consolidation
 
   @doc """
-  Extracts all protocols from the given paths.
+  Extract all protocols from the given paths.
 
-  The paths can be either a charlist or a string. Internally
-  they are worked on as charlists, so passing them as lists
+  The paths can be either a char list or a string. Internally
+  they are worked on as char lists, so passing them as lists
   avoid extra conversion.
 
   Does not load any of the protocols.
@@ -144,23 +143,23 @@ defmodule Protocol do
       true
 
   """
-  @spec extract_protocols([charlist | String.t]) :: [atom]
+  @spec extract_protocols([char_list | String.t]) :: [atom]
   def extract_protocols(paths) do
     extract_matching_by_attribute paths, 'Elixir.',
       fn module, attributes ->
         case attributes[:protocol] do
-          [fallback_to_any: _] -> module
+          [fallback_to_any: _, consolidated: _] -> module
           _ -> nil
         end
       end
   end
 
   @doc """
-  Extracts all types implemented for the given protocol from
+  Extract all types implemented for the given protocol from
   the given paths.
 
-  The paths can be either a charlist or a string. Internally
-  they are worked on as charlists, so passing them as lists
+  The paths can be either a char list or a string. Internally
+  they are worked on as char lists, so passing them as lists
   avoid extra conversion.
 
   Does not load any of the implementations.
@@ -174,12 +173,12 @@ defmodule Protocol do
       true
 
   """
-  @spec extract_impls(module, [charlist | String.t]) :: [atom]
+  @spec extract_impls(module, [char_list | String.t]) :: [atom]
   def extract_impls(protocol, paths) when is_atom(protocol) do
-    prefix = Atom.to_charlist(protocol) ++ '.'
+    prefix = Atom.to_char_list(protocol) ++ '.'
     extract_matching_by_attribute paths, prefix, fn
       _mod, attributes ->
-        case attributes[:protocol_impl] do
+        case attributes[:impl] do
           [protocol: ^protocol, for: for] -> for
           _ -> nil
         end
@@ -200,7 +199,7 @@ defmodule Protocol do
     end
   end
 
-  defp list_dir(path), do: list_dir(to_charlist(path))
+  defp list_dir(path), do: list_dir(to_char_list(path))
 
   defp extract_from_file(path, file, prefix, callback) do
     if :lists.prefix(prefix, file) and :filename.extension(file) == '.beam' do
@@ -217,12 +216,21 @@ defmodule Protocol do
     end
   end
 
+  defmacrop if_ok(expr, call) do
+    quote do
+      case unquote(expr) do
+        {:ok, var} -> unquote(Macro.pipe(quote(do: var), call, 0))
+        other -> other
+      end
+    end
+  end
+
   @doc """
-  Returns `true` if the protocol was consolidated.
+  Returns true if the protocol was consolidated.
   """
   @spec consolidated?(module) :: boolean
   def consolidated?(protocol) do
-    protocol.__protocol__(:consolidated?)
+    protocol.__info__(:attributes)[:protocol][:consolidated]
   end
 
   @doc """
@@ -241,7 +249,7 @@ defmodule Protocol do
 
       Protocol.consolidated?(Enumerable)
 
-  If the first element of the tuple is `true`, it means
+  If the first element of the tuple is true, it means
   the protocol was consolidated.
 
   This function does not load the protocol at any point
@@ -254,22 +262,23 @@ defmodule Protocol do
     {:error, :not_a_protocol} |
     {:error, :no_beam_info}
   def consolidate(protocol, types) when is_atom(protocol) do
-    with {:ok, ast_info, chunks_info} <- beam_protocol(protocol),
-         {:ok, code} <- change_debug_info(ast_info, types),
-         do: compile(protocol, code, chunks_info)
+    beam_protocol(protocol)
+    |> if_ok(change_debug_info types)
+    |> if_ok(compile)
   end
 
+  @docs_chunk 'ExDc'
+
   defp beam_protocol(protocol) do
-    chunk_ids = [:abstract_code, :attributes, :compile_info, 'ExDc']
+    chunk_ids = [:abstract_code, :attributes, @docs_chunk]
     opts = [:allow_missing_chunks]
     case :beam_lib.chunks(beam_file(protocol), chunk_ids, opts) do
       {:ok, {^protocol, [{:abstract_code, {_raw, abstract_code}},
                          {:attributes, attributes},
-                         {:compile_info, compile_info},
-                         {'ExDc', docs}]}} ->
+                         {@docs_chunk, docs}]}} ->
         case attributes[:protocol] do
-          [fallback_to_any: any] ->
-            {:ok, {protocol, any, abstract_code}, {compile_info, docs}}
+          [fallback_to_any: any, consolidated: _] ->
+            {:ok, {protocol, any, abstract_code, docs}}
           _ ->
             {:error, :not_a_protocol}
         end
@@ -287,81 +296,52 @@ defmodule Protocol do
 
   # Change the debug information to the optimized
   # impl_for/1 dispatch version.
-  defp change_debug_info({protocol, any, code}, types) do
+  defp change_debug_info({protocol, any, code, docs}, types) do
     types   = if any, do: types, else: List.delete(types, Any)
-    all     = [Any] ++ for {_guard, mod} <- __builtin__(), do: mod
+    all     = [Any] ++ for {_guard, mod} <- builtin, do: mod
     structs = types -- all
     case change_impl_for(code, protocol, types, structs, false, []) do
-      {:ok, ret} -> {:ok, ret}
+      {:ok, ret} -> {:ok, {ret, docs}}
       other      -> other
     end
   end
 
-  defp change_impl_for([{:function, line, :__protocol__, 1, clauses} | tail], protocol, types, structs, _, acc) do
-    abstract_types = :erl_parse.abstract(:lists.usort(types))
-
-    clauses = :lists.map(fn
-      {:clause, l, [{:atom, _, :consolidated?}], [], [{:atom, _, _}]} ->
-        {:clause, l, [{:atom, 0, :consolidated?}], [], [{:atom, 0, true}]}
-      {:clause, l, [{:atom, _, :impls}], [], [{:atom, _, _}]} ->
-        {:clause, l, [{:atom, 0, :impls}], [], [{:tuple, 0, [{:atom, 0, :consolidated}, abstract_types]}]}
-      {:clause, _, _, _, _} = c ->
-        c
-    end, clauses)
-
-    change_impl_for(tail, protocol, types, structs, true,
-                    [{:function, line, :__protocol__, 1, clauses} | acc])
+  defp change_impl_for([{:attribute, line, :protocol, opts}|t], protocol, types, structs, _, acc) do
+    opts = [fallback_to_any: opts[:fallback_to_any], consolidated: true]
+    change_impl_for(t, protocol, types, structs, true,
+                    [{:attribute, line, :protocol, opts}|acc])
   end
 
-  defp change_impl_for([{:function, line, :impl_for, 1, _} | tail], protocol, types, structs, protocol?, acc) do
-    fallback = if Any in types, do: load_impl(protocol, Any)
+  defp change_impl_for([{:function, line, :impl_for, 1, _}|t], protocol, types, structs, is_protocol, acc) do
+    fallback = if Any in types, do: load_impl(protocol, Any), else: nil
 
-    clauses = for {guard, mod} <- __builtin__(),
+    clauses = for {guard, mod} <- builtin,
                   mod in types,
                   do: builtin_clause_for(mod, guard, protocol, line)
 
-    clauses = [struct_clause_for(line) | clauses] ++
+    clauses = [struct_clause_for(line)|clauses] ++
               [fallback_clause_for(fallback, protocol, line)]
 
-    change_impl_for(tail, protocol, types, structs, protocol?,
-                    [{:function, line, :impl_for, 1, clauses} | acc])
+    change_impl_for(t, protocol, types, structs, is_protocol,
+                    [{:function, line, :impl_for, 1, clauses}|acc])
   end
 
-  defp change_impl_for([{:function, line, :struct_impl_for, 1, _} | tail], protocol, types, structs, protocol?, acc) do
-    fallback = if Any in types, do: load_impl(protocol, Any)
+  defp change_impl_for([{:function, line, :struct_impl_for, 1, _}|t], protocol, types, structs, is_protocol, acc) do
+    fallback = if Any in types, do: load_impl(protocol, Any), else: nil
     clauses = for struct <- structs, do: each_struct_clause_for(struct, protocol, line)
     clauses = clauses ++ [fallback_clause_for(fallback, protocol, line)]
 
-    change_impl_for(tail, protocol, types, structs, protocol?,
-                    [{:function, line, :struct_impl_for, 1, clauses} | acc])
+    change_impl_for(t, protocol, types, structs, is_protocol,
+                    [{:function, line, :struct_impl_for, 1, clauses}|acc])
   end
 
-  defp change_impl_for([{:attribute, line, :spec, {{:__protocol__, 1}, funspecs}} | tail], protocol, types, structs, protocol?, acc) do
-    new_specs = for spec <- funspecs do
-      case spec do
-        {:type, line, :fun, [{:type, _, :product, [{:atom, _, :consolidated?}]}, _]} ->
-          {:type, line, :fun,
-           [{:type, line, :product, [{:atom, 0, :consolidated?}]},
-            {:atom, 0, true}]}
-        {:type, line, :fun, [{:type, _, :product, [{:atom, _, :impls}]}, _]} ->
-          {:type, line, :fun,
-           [{:type, line, :product, [{:atom, 0, :impls}]},
-            {:type, 0, :tuple,
-             [{:atom, 0, :consolidated},
-              {:type, 0, :list, [{:type, 0, :module, []}]}]}]}
-        other -> other
-      end
-    end
-    change_impl_for(tail, protocol, types, structs, protocol?, [{:attribute, line, :spec, {{:__protocol__, 1}, new_specs}} | acc])
+  defp change_impl_for([h|t], protocol, info, types, is_protocol, acc) do
+    change_impl_for(t, protocol, info, types, is_protocol, [h|acc])
   end
 
-  defp change_impl_for([head | tail], protocol, info, types, protocol?, acc) do
-    change_impl_for(tail, protocol, info, types, protocol?, [head | acc])
-  end
-
-  defp change_impl_for([], _protocol, _info, _types, protocol?, acc) do
-    if protocol? do
-      {:ok, Enum.reverse(acc)}
+  defp change_impl_for([], protocol, _info, _types, is_protocol, acc) do
+    if is_protocol do
+      {:ok, {protocol, Enum.reverse(acc)}}
     else
       {:error, :not_a_protocol}
     end
@@ -391,9 +371,9 @@ defmodule Protocol do
           [{:var, line, :x}]}]}
   end
 
-  defp each_struct_clause_for(struct, protocol, line) do
-    {:clause, line, [{:atom, line, struct}], [],
-      [{:atom, line, load_impl(protocol, struct)}]}
+  defp each_struct_clause_for(other, protocol, line) do
+    {:clause, line, [{:atom, line, other}], [],
+      [{:atom, line, load_impl(protocol, other)}]}
   end
 
   defp fallback_clause_for(value, _protocol, line) do
@@ -406,15 +386,13 @@ defmodule Protocol do
   end
 
   # Finally compile the module and emit its bytecode.
-  defp compile(protocol, code, {compile_info, docs}) do
-    opts = Keyword.take(compile_info, [:source])
-    opts = if Code.compiler_options[:debug_info], do: [:debug_info | opts], else: opts
-    {:ok, ^protocol, binary, _warnings} = :compile.forms(code, [:return | opts])
-    {:ok,
-      case docs do
-        :missing_chunk -> binary
-        _ -> :elixir_erl.add_beam_chunks(binary, [{"ExDc", docs}])
-      end}
+  defp compile({{protocol, code}, docs}) do
+    opts = if Code.compiler_options[:debug_info], do: [:debug_info], else: []
+    {:ok, ^protocol, binary, _warnings} = :compile.forms(code, [:return|opts])
+    unless docs == :missing_chunk do
+      binary = :elixir_module.add_beam_chunk(binary, @docs_chunk, docs)
+    end
+    {:ok, binary}
   end
 
   ## Definition callbacks
@@ -440,18 +418,17 @@ defmodule Protocol do
         @fallback_to_any false
 
         # Invoke the user given block
-        _ = unquote(block)
+        unquote(block)
 
         # Finalize expansion
-        unquote(after_defprotocol())
+        unquote(after_defprotocol)
       end
     end
   end
 
   defp after_defprotocol do
-    quote bind_quoted: [builtin: __builtin__()] do
-      @doc false
-      @spec impl_for(term) :: atom | nil
+    quote bind_quoted: [builtin: builtin] do
+      @spec impl_for(term) :: atom() | nil
       Kernel.def impl_for(data)
 
       # Define the implementation for structs.
@@ -462,39 +439,33 @@ defmodule Protocol do
         struct_impl_for(struct)
       end
 
-      # Define the implementation for built-ins
-      :lists.foreach(fn {guard, mod} ->
+      # Define the implementation for builtins.
+      for {guard, mod} <- builtin do
         target = Module.concat(__MODULE__, mod)
 
         Kernel.def impl_for(data) when :erlang.unquote(guard)(data) do
           case impl_for?(unquote(target)) do
             true  -> unquote(target).__impl__(:target)
-            false -> any_impl_for()
+            false -> any_impl_for
           end
         end
-      end, builtin)
-
-      # Define a catch-all impl_for/1 clause to pacify Dialyzer (since
-      # destructuring opaque types is illegal, Dialyzer will think none of the
-      # previous clauses matches opaque types, and without this clause, will
-      # conclude that impl_for can't handle an opaque argument). This is a hack
-      # since it relies on Dialyzer not being smart enough to conclude that all
-      # opaque types will get the any_impl_for/0 implementation.
-      Kernel.def impl_for(_) do
-        any_impl_for()
       end
 
-      @doc false
-      @spec impl_for!(term) :: atom | no_return
+      @spec impl_for!(term) :: atom() | no_return()
       Kernel.def impl_for!(data) do
         impl_for(data) || raise(Protocol.UndefinedError, protocol: __MODULE__, value: data)
       end
 
       # Internal handler for Any
       if @fallback_to_any do
-        Kernel.defp any_impl_for(), do: __MODULE__.Any.__impl__(:target)
+        Kernel.defp any_impl_for do
+          case impl_for?(__MODULE__.Any) do
+            true  -> __MODULE__.Any.__impl__(:target)
+            false -> nil
+          end
+        end
       else
-        Kernel.defp any_impl_for(), do: nil
+        Kernel.defp any_impl_for, do: nil
       end
 
       # Internal handler for Structs
@@ -502,7 +473,7 @@ defmodule Protocol do
         target = Module.concat(__MODULE__, struct)
         case impl_for?(target) do
           true  -> target.__impl__(:target)
-          false -> any_impl_for()
+          false -> any_impl_for
         end
       end
 
@@ -522,25 +493,21 @@ defmodule Protocol do
       # Store information as an attribute so it
       # can be read without loading the module.
       Module.register_attribute(__MODULE__, :protocol, persist: true)
-      @protocol [fallback_to_any: !!@fallback_to_any]
+      @protocol [fallback_to_any: !!@fallback_to_any, consolidated: false]
 
       @doc false
-      @spec __protocol__(:module) :: __MODULE__
+      @spec __protocol__(:name) :: __MODULE__
       @spec __protocol__(:functions) :: unquote(Protocol.__functions_spec__(@functions))
-      @spec __protocol__(:consolidated?) :: false
-      @spec __protocol__(:impls) :: :not_consolidated
-      Kernel.def __protocol__(:module), do: __MODULE__
+      Kernel.def __protocol__(:name), do: __MODULE__
       Kernel.def __protocol__(:functions), do: unquote(:lists.sort(@functions))
-      Kernel.def __protocol__(:consolidated?), do: false
-      Kernel.def __protocol__(:impls), do: :not_consolidated
     end
   end
 
   @doc false
   def __functions_spec__([]),
     do: []
-  def __functions_spec__([head | tail]),
-    do: [:lists.foldl(&{:|, [], [&1, &2]}, head, tail), quote(do: ...)]
+  def __functions_spec__([h|t]),
+    do: [:lists.foldl(&{:|, [], [&1, &2]}, h, t), quote(do: ...)]
 
   @doc false
   def __impl__(protocol, opts) do
@@ -555,7 +522,7 @@ defmodule Protocol do
     # Unquote the implementation just later
     # when all variables will already be injected
     # into the module body.
-    impl =
+    __impl__ =
       quote unquote: false do
         @doc false
         @spec __impl__(:for) :: unquote(for)
@@ -572,7 +539,6 @@ defmodule Protocol do
       name     = Module.concat(protocol, for)
 
       Protocol.assert_protocol!(protocol)
-      Protocol.__ensure_defimpl__(protocol, for, __ENV__)
 
       defmodule name do
         @behaviour protocol
@@ -581,10 +547,10 @@ defmodule Protocol do
 
         unquote(block)
 
-        Module.register_attribute(__MODULE__, :protocol_impl, persist: true)
-        @protocol_impl [protocol: @protocol, for: @for]
+        Module.register_attribute(__MODULE__, :impl, persist: true)
+        @impl [protocol: @protocol, for: @for]
 
-        unquote(impl)
+        unquote(__impl__)
       end
     end
   end
@@ -612,13 +578,12 @@ defmodule Protocol do
   defp derive(protocol, for, struct, opts, env) do
     extra = ", cannot derive #{inspect protocol} for #{inspect for}"
     assert_protocol!(protocol, extra)
-    __ensure_defimpl__(protocol, for, env)
-    assert_impl!(protocol, Any, extra)
+    assert_impl!(protocol, Map, extra)
 
     # Clean up variables from eval context
     env  = %{env | vars: [], export_vars: nil}
     args = [for, struct, opts]
-    impl = Module.concat(protocol, Any)
+    impl = Module.concat(protocol, Map)
 
     :elixir_module.expand_callback(env.line, impl, :__deriving__, args, env, fn
       mod, fun, args ->
@@ -626,8 +591,8 @@ defmodule Protocol do
           apply(mod, fun, args)
         else
           Module.create(Module.concat(protocol, for), quote do
-            Module.register_attribute(__MODULE__, :protocol_impl, persist: true)
-            @protocol_impl [protocol: unquote(protocol), for: unquote(for)]
+            Module.register_attribute(__MODULE__, :impl, persist: true)
+            @impl [protocol: unquote(protocol), for: unquote(for)]
 
             @doc false
             @spec __impl__(:target) :: unquote(impl)
@@ -641,37 +606,24 @@ defmodule Protocol do
     end)
   end
 
-  @doc false
-  def __ensure_defimpl__(protocol, for, env) do
-    if Protocol.consolidated?(protocol) do
-      message =
-        "the #{inspect protocol} protocol has already been consolidated" <>
-        ", an implementation for #{inspect for} has no effect"
-      :elixir_errors.warn(env.line, env.file, message)
-    end
-    :ok
-  end
-
   @doc false
   def __spec__?(module, name, arity) do
     signature = {name, arity}
+    specs     = Module.get_attribute(module, :spec)
 
-    specs = Module.get_attribute(module, :spec)
     found =
-      :lists.map(fn {:spec, expr, pos} ->
-        if Kernel.Typespec.spec_to_signature(expr) == signature do
-          Module.store_typespec(module, :callback, {:callback, expr, pos})
-          true
-        end
-      end, specs)
+      for {:spec, expr, caller} <- specs,
+        Kernel.Typespec.spec_to_signature(expr) == signature do
+        Kernel.Typespec.define_spec(:callback, expr, caller)
+        true
+      end
 
-    :lists.any(& &1 == true, found)
+    found != []
   end
 
   ## Helpers
 
-  @doc false
-  def __builtin__ do
+  defp builtin do
     [is_tuple: Tuple,
      is_atom: Atom,
      is_list: List,

lib/elixir/lib/range.ex

@@ -1,65 +1,35 @@
 defmodule Range do
   @moduledoc """
-  Defines a range.
+  Defines a Range.
 
-  A range represents a discrete number of values where
-  the first and last values are integers.
-
-  Ranges can be either increasing (`first <= last`) or
-  decreasing (`first > last`). Ranges are also always
-  inclusive.
-
-  A range is represented internally as a struct. However,
+  A Range is represented internally as a struct. However,
   the most common form of creating and matching on ranges
-  is via the `../2` macro, auto-imported from `Kernel`:
+  is via the `../2` macro, auto-imported from Kernel:
 
       iex> range = 1..3
       1..3
-      iex> first..last = range
+      iex> first .. last = range
       iex> first
       1
       iex> last
       3
 
-  A range implements the `Enumerable` protocol, which means
-  functions in the `Enum` module can be used to work with
-  ranges:
-
-      iex> range = 1..10
-      1..10
-      iex> Enum.reduce(range, 0, fn i, acc -> i * i + acc end)
-      385
-      iex> Enum.count(range)
-      10
-      iex> Enum.member?(range, 11)
-      false
-      iex> Enum.member?(range, 8)
-      true
-
   """
 
   defstruct first: nil, last: nil
 
-  @type t :: %Range{first: integer, last: integer}
+  @type t :: %Range{}
   @type t(first, last) :: %Range{first: first, last: last}
 
-
   @doc """
   Creates a new range.
   """
-  @spec new(integer, integer) :: t
-  def new(first, last) when is_integer(first) and is_integer(last) do
+  def new(first, last) do
     %Range{first: first, last: last}
   end
 
-  def new(first, last) do
-    raise ArgumentError,
-      "ranges (first..last) expect both sides to be integers, " <>
-      "got: #{inspect first}..#{inspect last}"
-  end
-
   @doc """
-  Returns `true` if the given `term` is a valid range.
+  Returns true if the given argument is a range.
 
   ## Examples
 
@@ -70,38 +40,52 @@ defmodule Range do
       false
 
   """
-  @spec range?(term) :: boolean
-  def range?(term)
-  def range?(first..last) when is_integer(first) and is_integer(last), do: true
+  def range?(%Range{}), do: true
   def range?(_), do: false
 end
 
+defprotocol Range.Iterator do
+  @moduledoc """
+  A protocol used for iterating range elements.
+  """
+
+  @doc """
+  Returns the function that calculates the next item.
+  """
+  def next(first, range)
+
+  @doc """
+  Count how many items are in the range.
+  """
+  def count(first, range)
+end
+
 defimpl Enumerable, for: Range do
-  def reduce(first..last, acc, fun) do
-    reduce(first, last, acc, fun, _up? = last >= first)
+  def reduce(first .. last = range, acc, fun) do
+    reduce(first, last, acc, fun, Range.Iterator.next(first, range), last >= first)
   end
 
-  defp reduce(_x, _y, {:halt, acc}, _fun, _up?) do
+  defp reduce(_x, _y, {:halt, acc}, _fun, _next, _up) do
     {:halted, acc}
   end
 
-  defp reduce(x, y, {:suspend, acc}, fun, up?) do
-    {:suspended, acc, &reduce(x, y, &1, fun, up?)}
+  defp reduce(x, y, {:suspend, acc}, fun, next, up) do
+    {:suspended, acc, &reduce(x, y, &1, fun, next, up)}
   end
 
-  defp reduce(x, y, {:cont, acc}, fun, _up? = true) when x <= y do
-    reduce(x + 1, y, fun.(x, acc), fun, _up? = true)
+  defp reduce(x, y, {:cont, acc}, fun, next, true) when x <= y do
+    reduce(next.(x), y, fun.(x, acc), fun, next, true)
   end
 
-  defp reduce(x, y, {:cont, acc}, fun, _up? = false) when x >= y do
-    reduce(x - 1, y, fun.(x, acc), fun, _up? = false)
+  defp reduce(x, y, {:cont, acc}, fun, next, false) when x >= y do
+    reduce(next.(x), y, fun.(x, acc), fun, next, false)
   end
 
-  defp reduce(_, _, {:cont, acc}, _fun, _up) do
+  defp reduce(_, _, {:cont, acc}, _fun, _next, _up) do
     {:done, acc}
   end
 
-  def member?(first..last, value) when is_integer(value) do
+  def member?(first .. last, value) do
     if first <= last do
       {:ok, first <= value and value <= last}
     else
@@ -109,15 +93,25 @@ defimpl Enumerable, for: Range do
     end
   end
 
-  def member?(_.._, _value) do
-    {:ok, false}
+  def count(first .. _ = range) do
+    {:ok, Range.Iterator.count(first, range)}
+  end
+end
+
+defimpl Range.Iterator, for: Integer do
+  def next(first, _ .. last) when is_integer(last) do
+    if last >= first do
+      &(&1 + 1)
+    else
+      &(&1 - 1)
+    end
   end
 
-  def count(first..last) do
-    if first <= last do
-      {:ok, last - first + 1}
+  def count(first, _ .. last) when is_integer(last) do
+    if last >= first do
+      last - first + 1
     else
-      {:ok, first - last + 1}
+      first - last + 1
     end
   end
 end
@@ -125,7 +119,7 @@ end
 defimpl Inspect, for: Range do
   import Inspect.Algebra
 
-  def inspect(first..last, opts) do
+  def inspect(first .. last, opts) do
     concat [to_doc(first, opts), "..", to_doc(last, opts)]
   end
 end

lib/elixir/lib/record.ex

@@ -1,6 +1,6 @@
 defmodule Record do
   @moduledoc """
-  Module to work with, define, and import records.
+  Module to work, define and import records.
 
   Records are simply tuples where the first element is an atom:
 
@@ -10,57 +10,38 @@ defmodule Record do
   This module provides conveniences for working with records at
   compilation time, where compile-time field names are used to
   manipulate the tuples, providing fast operations on top of
-  the tuples' compact structure.
+  the tuples compact structure.
 
   In Elixir, records are used mostly in two situations:
 
     1. to work with short, internal data
     2. to interface with Erlang records
 
-  The macros `defrecord/3` and `defrecordp/3` can be used to create records
-  while `extract/2` and `extract_all/1` can be used to extract records from
-  Erlang files.
+  The macros `defrecord/3` and `defrecordp/3` can be used to create
+  records while `extract/2` can be used to extract records from Erlang
+  files.
 
   ## Types
 
-  Types can be defined for tuples with the `record/2` macro (only available in
-  typespecs). This macro will expand to a tuple as seen in the example below:
+  Types can be defined for tuples with the `record/2` macro (only available
+  in typespecs). Like with the generated record macros it will expand to
+  a tuple.
 
       defmodule MyModule do
         require Record
-        Record.defrecord :user, name: "john", age: 25
+        Record.defrecord :user name: "john", age: 25
 
         @type user :: record(:user, name: String.t, age: integer)
-        # expands to: "@type user :: {:user, String.t, integer}"
+        # expands to: `@type user :: {:user, String.t, integer}`
       end
-
   """
 
   @doc """
   Extracts record information from an Erlang file.
 
   Returns a quoted expression containing the fields as a list
-  of tuples.
-
-  `name`, which is the name of the extracted record, is expected to be an atom
-  *at compile time*.
-
-  ## Options
-
-  This function accepts the following options, which are exclusive to each other
-  (i.e., only one of them can be used in the same call):
-
-    * `:from` - (binary representing a path to a file) path to the Erlang file
-      that contains the record definition to extract; with this option, this
-      function uses the same path lookup used by the `-include` attribute used in
-      Erlang modules.
-    * `:from_lib` - (binary representing a path to a file) path to the Erlang
-      file that contains the record definition to extract; with this option,
-      this function uses the same path lookup used by the `-include_lib`
-      attribute used in Erlang modules.
-
-  These options are expected to be literals (including the binary values) at
-  compile time.
+  of tuples. It expects the record name to be an atom and the
+  library path to be a string at expansion time.
 
   ## Examples
 
@@ -71,42 +52,12 @@ defmodule Record do
        uid: :undefined, gid: :undefined]
 
   """
-  @spec extract(name :: atom, keyword) :: keyword
-  def extract(name, opts) when is_atom(name) and is_list(opts) do
-    Record.Extractor.extract(name, opts)
+  defmacro extract(name, opts) when is_atom(name) and is_list(opts) do
+    Macro.escape Record.Extractor.extract(name, opts)
   end
 
   @doc """
-  Extracts all records information from an Erlang file.
-
-  Returns a keyword list of `{record_name, fields}` tuples where `record_name`
-  is the name of an extracted record and `fields` is a list of `{field, value}`
-  tuples representing the fields for that record.
-
-  ## Options
-
-  This function accepts the following options, which are exclusive to each other
-  (i.e., only one of them can be used in the same call):
-
-    * `:from` - (binary representing a path to a file) path to the Erlang file
-      that contains the record definitions to extract; with this option, this
-      function uses the same path lookup used by the `-include` attribute used in
-      Erlang modules.
-    * `:from_lib` - (binary representing a path to a file) path to the Erlang
-      file that contains the record definitions to extract; with this option,
-      this function uses the same path lookup used by the `-include_lib`
-      attribute used in Erlang modules.
-
-  These options are expected to be literals (including the binary values) at
-  compile time.
-  """
-  @spec extract_all(keyword) :: [{name :: atom, keyword}]
-  def extract_all(opts) when is_list(opts) do
-    Record.Extractor.extract_all(opts)
-  end
-
-  @doc """
-  Checks if the given `data` is a record of kind `kind`.
+  Checks if the given `data` is a record of `kind`.
 
   This is implemented as a macro so it can be used in guard clauses.
 
@@ -121,14 +72,14 @@ defmodule Record do
     case Macro.Env.in_guard?(__CALLER__) do
       true ->
         quote do
-          is_atom(unquote(kind)) and is_tuple(unquote(data)) and tuple_size(unquote(data)) > 0 and
-            elem(unquote(data), 0) == unquote(kind)
+          is_tuple(unquote(data)) and tuple_size(unquote(data)) > 0
+            and :erlang.element(1, unquote(data)) == unquote(kind)
         end
       false ->
         quote do
           result = unquote(data)
-          kind = unquote(kind)
-          is_atom(kind) and is_tuple(result) and tuple_size(result) > 0 and elem(result, 0) == kind
+          is_tuple(result) and tuple_size(result) > 0
+            and :erlang.element(1, result) == unquote(kind)
         end
     end
   end
@@ -152,39 +103,24 @@ defmodule Record do
     case Macro.Env.in_guard?(__CALLER__) do
       true ->
         quote do
-          is_tuple(unquote(data)) and tuple_size(unquote(data)) > 0 and
-            is_atom(elem(unquote(data), 0))
+          is_tuple(unquote(data)) and tuple_size(unquote(data)) > 0
+            and is_atom(:erlang.element(1, unquote(data)))
         end
       false ->
         quote do
           result = unquote(data)
-          is_tuple(result) and tuple_size(result) > 0 and is_atom(elem(result, 0))
+          is_tuple(result) and tuple_size(result) > 0
+            and is_atom(:erlang.element(1, result))
         end
     end
   end
 
   @doc """
-  Defines a set of macros to create, access, and pattern match
-  on a record.
+  Defines a set of macros to create and access a record.
 
-  The name of the generated macros will be `name` (which has to be an
-  atom). `tag` is also an atom and is used as the "tag" for the record (i.e.,
-  the first element of the record tuple); by default (if `nil`), it's the same
-  as `name`. `kv` is a keyword list of `name: default_value` fields for the
-  new record.
-
-  The following macros are generated:
-
-    * `name/0` to create a new record with default values for all fields
-    * `name/1` to create a new record with the given fields and values,
-      to get the zero-based index of the given field in a record or to
-      convert the given record to a keyword list
-    * `name/2` to update an existing record with the given fields and values
-      or to access a given field in a given record
-
-  All these macros are public macros (as defined by `defmacro`).
-
-  See the "Examples" section for examples on how to use these macros.
+  The macros are going to have `name`, a tag (which defaults)
+  to the name if none is given, and a set of fields given by
+  `kv`.
 
   ## Examples
 
@@ -194,10 +130,7 @@ defmodule Record do
       end
 
   In the example above, a set of macros named `user` but with different
-  arities will be defined to manipulate the underlying record.
-
-      # Import the module to make the user macros locally available
-      import User
+  arities will be defined to manipulate the underlying record:
 
       # To create records
       record = user()        #=> {:user, "meg", 25}
@@ -209,52 +142,19 @@ defmodule Record do
       # To update the record
       user(record, age: 26) #=> {:user, "meg", 26}
 
-      # To get the zero-based index of the field in record tuple
-      # (index 0 is occupied by the record "tag")
-      user(:name) #=> 1
-
       # Convert a record to a keyword list
       user(record) #=> [name: "meg", age: 26]
 
-  The generated macros can also be used in order to pattern match on records and
-  to bind variables during the match:
-
-      record = user() #=> {:user, "meg", 25}
-
-      user(name: name) = record
-      name #=> "meg"
-
-  By default, Elixir uses the record name as the first element of the tuple (the "tag").
-  However, a different tag can be specified when defining a record,
-  as in the following example, in which we use `Customer` as the second argument of `defrecord/3`:
+  By default, Elixir uses the record name as the first element of
+  the tuple (the tag). But it can be changed to something else:
 
       defmodule User do
         require Record
-        Record.defrecord :user, Customer, name: nil
+        Record.defrecord :user, User, name: nil
       end
 
       require User
-      User.user() #=> {Customer, nil}
-
-  ## Defining extracted records with anonymous functions in the values
-
-  If a record defines an anonymous function in the default values, an
-  `ArgumentError` will be raised. This can happen unintentionally when defining
-  a record after extracting it from an Erlang library that uses anonymous
-  functions for defaults.
-
-      Record.defrecord :my_rec, Record.extract(...)
-      #=> ** (ArgumentError) invalid value for record field fun_field,
-      cannot escape #Function<12.90072148/2 in :erl_eval.expr/5>.
-
-  To work around this error, redefine the field with your own &M.f/a function,
-  like so:
-
-      defmodule MyRec do
-        require Record
-        Record.defrecord :my_rec, Record.extract(...) |> Keyword.merge(fun_field: &__MODULE__.foo/2)
-        def foo(bar, baz), do: IO.inspect({bar, baz})
-      end
+      User.user() #=> {User, nil}
 
   """
   defmacro defrecord(name, tag \\ nil, kv) do
@@ -294,14 +194,14 @@ defmodule Record do
   @doc false
   def __fields__(type, fields) do
     :lists.map(fn
-      {key, value} when is_atom(key) ->
+      {key, val} when is_atom(key) ->
         try do
-          Macro.escape(value)
+          Macro.escape(val)
         rescue
           e in [ArgumentError] ->
             raise ArgumentError, "invalid value for record field #{key}, " <> Exception.message(e)
         else
-          value -> {key, value}
+          val -> {key, val}
         end
       key when is_atom(key) ->
         {key, nil}
@@ -312,61 +212,62 @@ defmodule Record do
 
   # Callback invoked from record/0 and record/1 macros.
   @doc false
-  def __access__(tag, fields, args, caller) do
+  def __access__(atom, fields, args, caller) do
     cond do
       is_atom(args) ->
-        index(tag, fields, args)
+        index(atom, fields, args)
       Keyword.keyword?(args) ->
-        create(tag, fields, args, caller)
+        create(atom, fields, args, caller)
       true ->
-        fields = Macro.escape(fields)
         case Macro.expand(args, caller) do
-          {:{}, _, [^tag | list]} when length(list) == length(fields) ->
-            record = List.to_tuple([tag | list])
-            Record.__keyword__(tag, fields, record)
-          {^tag, arg} when length(fields) == 1 ->
-            Record.__keyword__(tag, fields, {tag, arg})
+          {:{}, _, [^atom|list]} when length(list) == length(fields) ->
+            record = List.to_tuple([atom|list])
+            Macro.escape(Record.__keyword__(atom, fields, record))
+          {^atom, arg} when length(fields) == 1 ->
+            Macro.escape(Record.__keyword__(atom, fields, {atom, arg}))
           _ ->
-            quote do: Record.__keyword__(unquote(tag), unquote(fields), unquote(args))
+            quote do: Record.__keyword__(unquote(atom), unquote(fields), unquote(args))
         end
     end
   end
 
   # Callback invoked from the record/2 macro.
   @doc false
-  def __access__(tag, fields, record, args, caller) do
+  def __access__(atom, fields, record, args, caller) do
     cond do
       is_atom(args) ->
-        get(tag, fields, record, args)
+        get(atom, fields, record, args)
       Keyword.keyword?(args) ->
-        update(tag, fields, record, args, caller)
+        update(atom, fields, record, args, caller)
       true ->
-        msg = "expected arguments to be a compile time atom or a keyword list, got: #{Macro.to_string args}"
+        msg = "expected arguments to be a compile time atom or keywords, got: #{Macro.to_string args}"
         raise ArgumentError, msg
     end
   end
 
   # Gets the index of field.
-  defp index(tag, fields, field) do
+  defp index(atom, fields, field) do
     if index = find_index(fields, field, 0) do
       index - 1 # Convert to Elixir index
     else
-      raise ArgumentError, "record #{inspect tag} does not have the key: #{inspect field}"
+      raise ArgumentError, "record #{inspect atom} does not have the key: #{inspect field}"
     end
   end
 
   # Creates a new record with the given default fields and keyword values.
-  defp create(tag, fields, keyword, caller) do
+  defp create(atom, fields, keyword, caller) do
     in_match = Macro.Env.in_match?(caller)
-    keyword = apply_underscore(fields, keyword)
 
     {match, remaining} =
       Enum.map_reduce(fields, keyword, fn({field, default}, each_keyword) ->
         new_fields =
-          case Keyword.fetch(each_keyword, field) do
-            {:ok, value} -> value
-            :error when in_match -> {:_, [], nil}
-            :error -> Macro.escape(default)
+          case Keyword.has_key?(each_keyword, field) do
+            true  -> Keyword.get(each_keyword, field)
+            false ->
+              case in_match do
+                true  -> {:_, [], nil}
+                false -> Macro.escape(default)
+              end
           end
 
         {new_fields, Keyword.delete(each_keyword, field)}
@@ -374,21 +275,19 @@ defmodule Record do
 
     case remaining do
       [] ->
-        {:{}, [], [tag | match]}
+        {:{}, [], [atom|match]}
       _  ->
         keys = for {key, _} <- remaining, do: key
-        raise ArgumentError, "record #{inspect tag} does not have the key: #{inspect hd(keys)}"
+        raise ArgumentError, "record #{inspect atom} does not have the key: #{inspect hd(keys)}"
     end
   end
 
   # Updates a record given by var with the given keyword.
-  defp update(tag, fields, var, keyword, caller) do
+  defp update(atom, fields, var, keyword, caller) do
     if Macro.Env.in_match?(caller) do
       raise ArgumentError, "cannot invoke update style macro inside match"
     end
 
-    keyword = apply_underscore(fields, keyword)
-
     Enum.reduce keyword, var, fn({key, value}, acc) ->
       index = find_index(fields, key, 0)
       if index do
@@ -396,62 +295,41 @@ defmodule Record do
           :erlang.setelement(unquote(index), unquote(acc), unquote(value))
         end
       else
-        raise ArgumentError, "record #{inspect tag} does not have the key: #{inspect key}"
+        raise ArgumentError, "record #{inspect atom} does not have the key: #{inspect key}"
       end
     end
   end
 
   # Gets a record key from the given var.
-  defp get(tag, fields, var, key) do
+  defp get(atom, fields, var, key) do
     index = find_index(fields, key, 0)
     if index do
       quote do
         :erlang.element(unquote(index), unquote(var))
       end
     else
-      raise ArgumentError, "record #{inspect tag} does not have the key: #{inspect key}"
+      raise ArgumentError, "record #{inspect atom} does not have the key: #{inspect key}"
     end
   end
 
-  defp find_index([{k, _} | _], k, i), do: i + 2
-  defp find_index([{_, _} | t], k, i), do: find_index(t, k, i + 1)
+  defp find_index([{k, _}|_], k, i), do: i + 2
+  defp find_index([{_, _}|t], k, i), do: find_index(t, k, i + 1)
   defp find_index([], _k, _i), do: nil
 
   # Returns a keyword list of the record
   @doc false
-  def __keyword__(tag, fields, record) do
-    if is_record(record, tag) do
-      [_tag | values] = Tuple.to_list(record)
-      case join_keyword(fields, values, []) do
-        kv when is_list(kv) ->
-          kv
-        expected_fields ->
-          msg = "expected argument to be a #{inspect tag} record with #{expected_fields} fields, got: #{inspect record}"
-          raise ArgumentError, msg
-      end
+  def __keyword__(atom, fields, record) do
+    if is_record(record, atom) do
+      [_tag|values] = Tuple.to_list(record)
+      join_keyword(fields, values, [])
     else
-      msg = "expected argument to be a literal atom, literal keyword or a #{inspect tag} record, got runtime: #{inspect record}"
+      msg = "expected argument to be a literal atom, literal keyword or a #{inspect atom} record, got runtime: #{inspect record}"
       raise ArgumentError, msg
     end
   end
 
-  # Returns a keyword list, or expected number of fields on size mismatch
-  defp join_keyword([{field, _default} | fields], [value | values], acc),
-    do: join_keyword(fields, values, [{field, value} | acc])
+  defp join_keyword([{field, _default}|fields], [value|values], acc),
+    do: join_keyword(fields, values, [{field, value}| acc])
   defp join_keyword([], [], acc),
     do: :lists.reverse(acc)
-  defp join_keyword(rest_fields, _rest_values, acc),
-    do: length(acc) + length(rest_fields) # expected fields
-
-  defp apply_underscore(fields, keyword) do
-    case Keyword.fetch(keyword, :_) do
-      {:ok, default} ->
-        fields
-        |> Enum.map(fn {k, _} -> {k, default} end)
-        |> Keyword.merge(keyword)
-        |> Keyword.delete(:_)
-      :error ->
-        keyword
-    end
-  end
 end

lib/elixir/lib/record/extractor.ex

@@ -4,44 +4,27 @@ defmodule Record.Extractor do
   # Retrieve a record definition from an Erlang file using
   # the same lookup as the *include* attribute from Erlang modules.
   def extract(name, from: file) when is_binary(file) do
-    extract_record(name, from_file(file))
+    file = String.to_char_list(file)
+
+    realfile =
+      case :code.where_is_file(file) do
+        :non_existing -> file
+        realfile -> realfile
+      end
+
+    extract_record(name, realfile)
   end
 
   # Retrieve a record definition from an Erlang file using
   # the same lookup as the *include_lib* attribute from Erlang modules.
   def extract(name, from_lib: file) when is_binary(file) do
-    extract_record(name, from_lib_file(file))
-  end
+    [app|path] = :filename.split(String.to_char_list(file))
 
-  # Retrieve all records definitions from an Erlang file using
-  # the same lookup as the *include* attribute from Erlang modules.
-  def extract_all(from: file) when is_binary(file) do
-    extract_all_records(from_file(file))
-  end
-
-  # Retrieve all records definitions from an Erlang file using
-  # the same lookup as the *include_lib* attribute from Erlang modules.
-  def extract_all(from_lib: file) when is_binary(file) do
-    extract_all_records(from_lib_file(file))
-  end
-
-  # Find file using the same lookup as the *include* attribute from Erlang modules.
-  defp from_file(file) do
-    file = String.to_charlist(file)
-    case :code.where_is_file(file) do
-      :non_existing -> file
-      realfile -> realfile
-    end
-  end
-
-  # Find file using the same lookup as the *include_lib* attribute from Erlang modules.
-  defp from_lib_file(file) do
-    [app | path] = :filename.split(String.to_charlist(file))
     case :code.lib_dir(List.to_atom(app)) do
       {:error, _} ->
         raise ArgumentError, "lib file #{file} could not be found"
       libpath ->
-        :filename.join([libpath | path])
+        extract_record name, :filename.join([libpath|path])
     end
   end
 
@@ -56,24 +39,16 @@ defmodule Record.Extractor do
     end
   end
 
-  # Retrieve all records from the given file
-  defp extract_all_records(file) do
-    form = read_file(file)
-    records = extract_records(form)
-    for rec = {name, _fields} <- records, do: {name, parse_record(rec, form)}
-  end
-
   # Parse the given file and extract all existent records.
   defp extract_records(form) do
     for {:attribute, _, :record, record} <- form, do: record
   end
 
   # Read a file and return its abstract syntax form that also
-  # includes record but with macros and other attributes expanded,
-  # such as "-include(...)" and "-include_lib(...)". This is done
-  # by using Erlang's epp.
+  # includes record and other preprocessor modules. This is done
+  # by using Erlang's epp_dodger.
   defp read_file(file) do
-    case :epp.parse_file(file, []) do
+    case :epp_dodger.quick_parse_file(file) do
       {:ok, form} ->
         form
       other ->
@@ -105,11 +80,11 @@ defmodule Record.Extractor do
 
   defp eval_record(cons, form) do
     form = form ++
-      [{:function, 0, :hello, 0, [
-         {:clause, 0, [], [], [cons]}]}]
+      [ {:function, 0, :hello, 0, [
+          {:clause, 0, [], [], [ cons ]} ]} ]
 
     {:function, 0, :hello, 0, [
-      {:clause, 0, [], [], [record_ast]}]} = :erl_expand_records.module(form, []) |> List.last
+      {:clause, 0, [], [], [ record_ast ]} ]} = :erl_expand_records.module(form, []) |> List.last
 
     {:value, record, _} = :erl_eval.expr(record_ast, [])
     record

lib/elixir/lib/regex.ex

@@ -1,60 +1,32 @@
 defmodule Regex do
   @moduledoc ~S"""
-  Provides regular expressions for Elixir.
+  Regular expressions for Elixir built on top of Erlang's `re` module.
 
-  Regex is based on PCRE (Perl Compatible Regular Expressions) and
-  built on top of Erlang's `:re` module. More information can be found
-  in the [`:re` module documentation](http://www.erlang.org/doc/man/re.html).
+  As the `re` module, Regex is based on PCRE
+  (Perl Compatible Regular Expressions). More information can be
+  found in the [`re` documentation](http://www.erlang.org/doc/man/re.html).
 
-  Regular expressions in Elixir can be created using the sigils
-  [`~r`](Kernel.html#sigil_r/2) or [`~R`](Kernel.html#sigil_R/2):
+  Regular expressions in Elixir can be created using `Regex.compile!/2`
+  or using the special form with [`~r`](Kernel.html#sigil_r/2):
 
       # A simple regular expressions that matches foo anywhere in the string
       ~r/foo/
 
-      # A regular expression with case insensitive and Unicode options
+      # A regular expression with case insensitive and unicode options
       ~r/foo/iu
 
-  Regular expressions created via sigils are pre-compiled and stored
-  in the `.beam` file. Notice this may be a problem if you are precompiling
-  Elixir, see the "Precompilation" section for more information.
-
   A Regex is represented internally as the `Regex` struct. Therefore,
   `%Regex{}` can be used whenever there is a need to match on them.
-  Keep in mind it is not guaranteed two regular expressions from the
-  same source are equal, for example:
-
-      ~r/(?<foo>.)(?<bar>.)/ == ~r/(?<foo>.)(?<bar>.)/
-
-  may return `true` or `false` depending on your machine, endianess,
-  available optimizations and others. You can, however, retrieve the source
-  of a compiled regular expression by accessing the `source` field, and then
-  compare those directly:
-
-      ~r/(?<foo>.)(?<bar>.)/.source == ~r/(?<foo>.)(?<bar>.)/.source
-
-  ## Precompilation
-
-  Regular expressions built with sigil are precompiled and stored in `.beam`
-  files. This may be a problem if you are precompiling Elixir to run in
-  different OTP releases, as OTP releases may update the underlying regular
-  expression engine at any time.
-
-  For such reasons, we always recomend precompiling Elixir projects using
-  the OTP version meant to run in production. In case cross-compilation is
-  really necessary, you can manually invoke `Regex.recompile/1` or `Regex.
-  recompile!/1` to perform a runtime version check and recompile the regex
-  if necessary.
 
   ## Modifiers
 
   The modifiers available when creating a Regex are:
 
-    * `unicode` (u) - enables Unicode specific patterns like `\p` and change
-      modifiers like `\w`, `\W`, `\s` and friends to also match on Unicode.
-      It expects valid Unicode strings to be given on match
+    * `unicode` (u) - enables unicode specific patterns like `\p` and changes
+      modifiers like `\w`, `\W`, `\s` and friends to also match on unicode.
+      It expects valid unicode strings to be given on match
 
-    * `caseless` (i) - adds case insensitivity
+    * `caseless` (i) - add case insensitivity
 
     * `dotall` (s) - causes dot to match newlines and also set newline to
       anycrlf; the new line setting can be overridden by setting `(*CR)` or
@@ -69,8 +41,7 @@ defmodule Regex do
     * `firstline` (f) - forces the unanchored pattern to match before or at the
       first newline, though the matched text may continue over the newline
 
-    * `ungreedy` (U) - inverts the "greediness" of the regexp
-      (the previous `r` option is deprecated in favor of `U`)
+    * `ungreedy` (r) - inverts the "greediness" of the regexp
 
   The options not available are:
 
@@ -83,7 +54,7 @@ defmodule Regex do
 
   ## Captures
 
-  Many functions in this module handle what to capture in a regex
+  Many functions in this module allows what to capture in a regex
   match via the `:capture` option. The supported values are:
 
     * `:all` - all captured subpatterns including the complete matching string
@@ -97,7 +68,7 @@ defmodule Regex do
       explicitly captured subpatterns, but not the complete matching part of
       the string
 
-    * `:none` - does not return matching subpatterns at all
+    * `:none` - do not return matching subpatterns at all
 
     * `:all_names` - captures all names in the Regex
 
@@ -105,7 +76,7 @@ defmodule Regex do
 
   """
 
-  defstruct re_pattern: nil, source: "", opts: "", re_version: ""
+  defstruct re_pattern: nil, source: "", opts: ""
 
   @type t :: %__MODULE__{re_pattern: term, source: binary, opts: binary}
 
@@ -118,7 +89,7 @@ defmodule Regex do
 
   The given options can either be a binary with the characters
   representing the same regex options given to the `~r` sigil,
-  or a list of options, as expected by the Erlang's `:re` module.
+  or a list of options, as expected by the [Erlang `re` docs](http://www.erlang.org/doc/man/re.html).
 
   It returns `{:ok, regex}` in case of success,
   `{:error, reason}` otherwise.
@@ -133,84 +104,40 @@ defmodule Regex do
 
   """
   @spec compile(binary, binary | [term]) :: {:ok, t} | {:error, any}
-  def compile(source, options \\ "") do
-    compile(source, options, version())
-  end
+  def compile(source, options \\ "")
 
-  defp compile(source, options, version) when is_binary(options) do
+  def compile(source, options) when is_binary(options) do
     case translate_options(options, []) do
       {:error, rest} ->
         {:error, {:invalid_option, rest}}
 
       translated_options ->
-        compile(source, translated_options, options, version)
+        compile(source, translated_options, options)
     end
   end
 
-  defp compile(source, options, version) when is_list(options) do
-    compile(source, options, "", version)
+  def compile(source, options) when is_list(options) do
+    compile(source, options, "")
   end
 
-  defp compile(source, opts, doc_opts, version) when is_binary(source) do
+  defp compile(source, opts, doc_opts) when is_binary(source) do
     case :re.compile(source, opts) do
       {:ok, re_pattern} ->
-        {:ok, %Regex{re_pattern: re_pattern, re_version: version, source: source, opts: doc_opts}}
+        {:ok, %Regex{re_pattern: re_pattern, source: source, opts: doc_opts}}
       error ->
         error
     end
   end
 
   @doc """
-  Compiles the regular expression and raises `Regex.CompileError` in case of errors.
+  Compiles the regular expression according to the given options.
+  Fails with `Regex.CompileError` if the regex cannot be compiled.
   """
-  @spec compile!(binary, binary | [term]) :: t
+  @spec compile(binary, binary | [term]) :: t
   def compile!(source, options \\ "") do
     case compile(source, options) do
       {:ok, regex} -> regex
-      {:error, {reason, at}} -> raise Regex.CompileError, "#{reason} at position #{at}"
-    end
-  end
-
-  @doc """
-  Recompiles the existing regular expression if necessary.
-
-  This checks the version stored in the regular expression
-  and recompiles the regex in case of version mismatch.
-  """
-  @spec recompile(t) :: t
-  def recompile(%Regex{} = regex) do
-    version = version()
-
-    # We use Map.get/3 by choice to support old regexes versions.
-    case Map.get(regex, :re_version, :error) do
-      ^version ->
-        {:ok, regex}
-      _ ->
-        %{source: source, opts: opts} = regex
-        compile(source, opts, version)
-    end
-  end
-
-  @doc """
-  Recompiles the existing regular expression and raises `Regex.CompileError` in case of errors.
-  """
-  @spec recompile!(t) :: t
-  def recompile!(regex) do
-    case recompile(regex) do
-      {:ok, regex} -> regex
-      {:error, {reason, at}} -> raise Regex.CompileError, "#{reason} at position #{at}"
-    end
-  end
-
-  @doc """
-  Returns the version of the underlying Regex engine.
-  """
-  # TODO: No longer check for function_exported? on OTP 20+.
-  def version do
-    if function_exported?(:re, :version, 0) do
-      :re.version()
-    else
-      "8.33 2013-05-29"
+      {:error, {reason, at}} -> raise Regex.CompileError, message: "#{reason} at position #{at}"
     end
   end
 
@@ -232,8 +159,7 @@ defmodule Regex do
   end
 
   @doc """
-  Returns `true` if the given `term` is a regex.
-  Otherwise returns `false`.
+  Returns true if the given argument is a regex.
 
   ## Examples
 
@@ -244,8 +170,8 @@ defmodule Regex do
       false
 
   """
-  @spec regex?(any) :: boolean
-  def regex?(term)
+  @spec regex?(t) :: true
+  @spec regex?(any) :: false
   def regex?(%Regex{}), do: true
   def regex?(_), do: false
 
@@ -255,9 +181,9 @@ defmodule Regex do
 
   ## Options
 
-    * `:return`  - sets to `:index` to return indexes. Defaults to `:binary`.
+    * `:return`  - set to `:index` to return indexes. Defaults to `:binary`.
     * `:capture` - what to capture in the result. Check the moduledoc for `Regex`
-      to see the possible capture values.
+                   to see the possible capture values.
 
   ## Examples
 
@@ -268,7 +194,7 @@ defmodule Regex do
       nil
 
       iex> Regex.run(~r/c(d)/, "abcd", return: :index)
-      [{2, 2}, {3, 1}]
+      [{2,2},{3,1}]
 
   """
   @spec run(t, binary, [term]) :: nil | [binary] | [{integer, integer}]
@@ -361,18 +287,17 @@ defmodule Regex do
     names
   end
 
-  @doc ~S"""
+  @doc """
   Same as `run/3`, but scans the target several times collecting all
-  matches of the regular expression.
-
-  A list of lists is returned, where each entry in the primary list represents a
-  match and each entry in the secondary list represents the captured contents.
+  matches of the regular expression. A list of lists is returned,
+  where each entry in the primary list represents a match and each
+  entry in the secondary list represents the captured contents.
 
   ## Options
 
-    * `:return`  - sets to `:index` to return indexes. Defaults to `:binary`.
+    * `:return`  - set to `:index` to return indexes. Defaults to `:binary`.
     * `:capture` - what to capture in the result. Check the moduledoc for `Regex`
-      to see the possible capture values.
+                   to see the possible capture values.
 
   ## Examples
 
@@ -385,9 +310,6 @@ defmodule Regex do
       iex> Regex.scan(~r/e/, "abcd")
       []
 
-      iex> Regex.scan(~r/\p{Sc}/u, "$, £, and €")
-      [["$"], ["£"], ["€"]]
-
   """
   @spec scan(t, String.t, [term]) :: [[String.t]]
   def scan(regex, string, options \\ [])
@@ -405,8 +327,7 @@ defmodule Regex do
   end
 
   @doc """
-  Splits the given target based on the given pattern and in the given number of
-  parts.
+  Splits the given target into the number of parts specified.
 
   ## Options
 
@@ -415,61 +336,46 @@ defmodule Regex do
       split the string into the maximum number of parts possible based on the
       given pattern.
 
-    * `:trim` - when `true`, removes empty strings (`""`) from the result.
+    * `:trim` - when true, remove blank strings from the result.
 
-    * `:on` - specifies which captures to split the string on, and in what
-      order. Defaults to `:first` which means captures inside the regex do not
-      affect the splitting process.
-
-    * `:include_captures` - when `true`, includes in the result the matches of
-      the regular expression. Defaults to `false`.
+    * `:on` - specifies which captures and order to split the string
+      on. Check the moduledoc for `Regex` to see the possible capture
+      values. Defaults to `:first` which means captures inside the
+      Regex does not affect the split result.
 
   ## Examples
 
-      iex> Regex.split(~r{-}, "a-b-c")
-      ["a", "b", "c"]
+      iex> Regex.split(~r/-/, "a-b-c")
+      ["a","b","c"]
 
-      iex> Regex.split(~r{-}, "a-b-c", [parts: 2])
-      ["a", "b-c"]
+      iex> Regex.split(~r/-/, "a-b-c", [parts: 2])
+      ["a","b-c"]
 
-      iex> Regex.split(~r{-}, "abc")
+      iex> Regex.split(~r/-/, "abc")
       ["abc"]
 
-      iex> Regex.split(~r{}, "abc")
+      iex> Regex.split(~r//, "abc")
       ["a", "b", "c", ""]
 
-      iex> Regex.split(~r{a(?<second>b)c}, "abc")
+      iex> Regex.split(~r/a(?<second>b)c/, "abc")
       ["", ""]
 
-      iex> Regex.split(~r{a(?<second>b)c}, "abc", on: [:second])
+      iex> Regex.split(~r/a(?<second>b)c/, "abc", on: [:second])
       ["a", "c"]
 
-      iex> Regex.split(~r{(x)}, "Elixir", include_captures: true)
-      ["Eli", "x", "ir"]
-
-      iex> Regex.split(~r{a(?<second>b)c}, "abc", on: [:second], include_captures: true)
-      ["a", "b", "c"]
-
   """
   @spec split(t, String.t, [term]) :: [String.t]
   def split(regex, string, options \\ [])
 
-  def split(%Regex{}, "", opts) do
-    if Keyword.get(opts, :trim, false) do
-      []
-    else
-      [""]
-    end
-  end
+  def split(%Regex{}, "", _opts), do: [""]
 
-  def split(%Regex{re_pattern: compiled}, string, opts) when is_binary(string) and is_list(opts) do
+  def split(%Regex{re_pattern: compiled}, string, opts) when is_binary(string) do
     on = Keyword.get(opts, :on, :first)
     case :re.run(string, compiled, [:global, capture: on]) do
       {:match, matches} ->
         do_split(matches, string, 0,
                  parts_to_index(Keyword.get(opts, :parts, :infinity)),
-                 Keyword.get(opts, :trim, false),
-                 Keyword.get(opts, :include_captures, false))
+                 Keyword.get(opts, :trim, false))
       :match ->
         [string]
       :nomatch ->
@@ -480,60 +386,41 @@ defmodule Regex do
   defp parts_to_index(:infinity),                      do: 0
   defp parts_to_index(n) when is_integer(n) and n > 0, do: n
 
-  defp do_split(_, string, offset, _counter, true, _with_captures) when byte_size(string) <= offset,
+  defp do_split(_, string, offset, _counter, true) when byte_size(string) <= offset,
     do: []
 
-  defp do_split(_, string, offset, 1, _trim, _with_captures),
+  defp do_split(_, string, offset, 1, _trim),
     do: [binary_part(string, offset, byte_size(string) - offset)]
 
-  defp do_split([], string, offset, _counter, _trim, _with_captures),
+  defp do_split([], string, offset, _counter, _trim),
     do: [binary_part(string, offset, byte_size(string) - offset)]
 
-  defp do_split([[{pos, _} | h] | t], string, offset, counter, trim, with_captures) when pos - offset < 0,
-    do: do_split([h | t], string, offset, counter, trim, with_captures)
+  defp do_split([[{pos, _}|h]|t], string, offset, counter, trim) when pos - offset < 0,
+    do: do_split([h|t], string, offset, counter, trim)
 
-  defp do_split([[] | t], string, offset, counter, trim, with_captures),
-    do: do_split(t, string, offset, counter, trim, with_captures)
+  defp do_split([[]|t], string, offset, counter, trim),
+    do: do_split(t, string, offset, counter, trim)
 
-  defp do_split([[{pos, length} | h] | t], string, offset, counter, trim, true) do
-    new_offset = pos + length
-    keep = pos - offset
-
-    if keep == 0 and length == 0 do
-      do_split([h | t], string, new_offset, counter, trim, true)
-    else
-      <<_::binary-size(offset), part::binary-size(keep), match::binary-size(length), _::binary>> = string
-
-      if keep == 0 and (length == 0 or trim) do
-        [match | do_split([h | t], string, new_offset, counter - 1, trim, true)]
-      else
-        [part, match | do_split([h | t], string, new_offset, counter - 1, trim, true)]
-      end
-    end
-  end
-
-  defp do_split([[{pos, length} | h] | t], string, offset, counter, trim, false) do
+  defp do_split([[{pos, length}|h]|t], string, offset, counter, trim) do
     new_offset = pos + length
     keep = pos - offset
 
     if keep == 0 and (length == 0 or trim) do
-      do_split([h | t], string, new_offset, counter, trim, false)
+      do_split([h|t], string, new_offset, counter, trim)
     else
       <<_::binary-size(offset), part::binary-size(keep), _::binary>> = string
-      [part | do_split([h | t], string, new_offset, counter - 1, trim, false)]
+      [part|do_split([h|t], string, new_offset, counter - 1, trim)]
     end
   end
 
   @doc ~S"""
   Receives a regex, a binary and a replacement, returns a new
-  binary where all matches are replaced by the replacement.
+  binary where the all matches are replaced by replacement.
 
   The replacement can be either a string or a function. The string
   is used as a replacement for every match and it allows specific
-  captures to be accessed via `\N` or `\g{N}`, where `N` is the
-  capture. In case `\0` is used, the whole match is inserted. Note
-  that in regexes the backslash needs to be escaped, hence in practice
-  you'll need to use `\\N` and `\\g{N}`.
+  captures to be accessed via `\N`, where `N` is the capture. In
+  case `\0` is used, the whole match is inserted.
 
   When the replacement is a function, the function may have arity
   N where each argument maps to a capture, with the first argument
@@ -543,7 +430,7 @@ defmodule Regex do
   ## Options
 
     * `:global` - when `false`, replaces only the first occurrence
-      (defaults to `true`)
+      (defaults to true)
 
   ## Examples
 
@@ -559,39 +446,31 @@ defmodule Regex do
       iex> Regex.replace(~r/a(b|d)c/, "abcadc", "[\\1]")
       "[b][d]"
 
-      iex> Regex.replace(~r/\.(\d)$/, "500.5", ".\\g{1}0")
-      "500.50"
-
       iex> Regex.replace(~r/a(b|d)c/, "abcadc", fn _, x -> "[#{x}]" end)
       "[b][d]"
 
-      iex> Regex.replace(~r/a/, "abcadc", "A", global: false)
-      "Abcadc"
-
   """
   @spec replace(t, String.t, String.t | (... -> String.t), [term]) :: String.t
   def replace(regex, string, replacement, options \\ [])
 
-  def replace(regex, string, replacement, options)
-      when is_binary(string) and is_binary(replacement) and is_list(options) do
+  def replace(regex, string, replacement, options) when is_binary(replacement) do
     do_replace(regex, string, precompile_replacement(replacement), options)
   end
 
-  def replace(regex, string, replacement, options)
-      when is_binary(string) and is_function(replacement) and is_list(options)  do
+  def replace(regex, string, replacement, options) when is_function(replacement) do
     {:arity, arity} = :erlang.fun_info(replacement, :arity)
     do_replace(regex, string, {replacement, arity}, options)
   end
 
   defp do_replace(%Regex{re_pattern: compiled}, string, replacement, options) do
     opts = if Keyword.get(options, :global) != false, do: [:global], else: []
-    opts = [{:capture, :all, :index} | opts]
+    opts = [{:capture, :all, :index}|opts]
 
     case :re.run(string, compiled, opts) do
       :nomatch ->
         string
-      {:match, [mlist | t]} when is_list(mlist) ->
-        apply_list(string, replacement, [mlist | t]) |> IO.iodata_to_binary
+      {:match, [mlist|t]} when is_list(mlist) ->
+        apply_list(string, replacement, [mlist|t]) |> IO.iodata_to_binary
       {:match, slist} ->
         apply_list(string, replacement, [slist]) |> IO.iodata_to_binary
     end
@@ -600,32 +479,32 @@ defmodule Regex do
   defp precompile_replacement(""),
     do: []
 
-  defp precompile_replacement(<<?\\, ?g, ?{, rest::binary>>) when byte_size(rest) > 0 do
-    {ns, <<?}, rest::binary>>} = pick_int(rest)
-    [List.to_integer(ns) | precompile_replacement(rest)]
-  end
-
-  defp precompile_replacement(<<?\\, ?\\, rest::binary>>) do
-    [<<?\\>> | precompile_replacement(rest)]
-  end
-
-  defp precompile_replacement(<<?\\, x, rest::binary>>) when x in ?0..?9 do
-    {ns, rest} = pick_int(rest)
-    [List.to_integer([x | ns]) | precompile_replacement(rest)]
-  end
-
-  defp precompile_replacement(<<x, rest::binary>>) do
+  defp precompile_replacement(<<?\\, x, rest :: binary>>) when x < ?0 or x > ?9 do
     case precompile_replacement(rest) do
       [head | t] when is_binary(head) ->
-        [<<x, head::binary>> | t]
+        [<<x, head :: binary>> | t]
       other ->
         [<<x>> | other]
     end
   end
 
-  defp pick_int(<<x, rest::binary>>) when x in ?0..?9 do
+  defp precompile_replacement(<<?\\, rest :: binary>>) when byte_size(rest) > 0 do
+    {ns, rest} = pick_int(rest)
+    [List.to_integer(ns) | precompile_replacement(rest)]
+  end
+
+  defp precompile_replacement(<<x, rest :: binary>>) do
+    case precompile_replacement(rest) do
+      [head | t] when is_binary(head) ->
+        [<<x, head :: binary>> | t]
+      other ->
+        [<<x>> | other]
+    end
+  end
+
+  defp pick_int(<<x, rest :: binary>>) when x in ?0..?9 do
     {found, rest} = pick_int(rest)
-    {[x | found], rest}
+    {[x|found], rest}
   end
 
   defp pick_int(bin) do
@@ -646,12 +525,12 @@ defmodule Regex do
 
   defp apply_list(whole, string, pos, replacement, [[{mpos, _} | _] | _] = list) when mpos > pos do
     length = mpos - pos
-    <<untouched::binary-size(length), rest::binary>> = string
+    <<untouched :: binary-size(length), rest :: binary>> = string
     [untouched | apply_list(whole, rest, mpos, replacement, list)]
   end
 
-  defp apply_list(whole, string, pos, replacement, [[{pos, length} | _] = head | tail]) do
-    <<_::size(length)-binary, rest::binary>> = string
+  defp apply_list(whole, string, pos, replacement, [[{mpos, length} | _] = head | tail]) when mpos == pos do
+    <<_ :: size(length)-binary, rest :: binary>> = string
     new_data = apply_replace(whole, replacement, head)
     [new_data | apply_list(whole, rest, pos + length, replacement, tail)]
   end
@@ -671,7 +550,7 @@ defmodule Regex do
       cond do
         is_binary(part) ->
           part
-        part >= tuple_size(indexes) ->
+        part > tuple_size(indexes) ->
           ""
         true ->
           get_index(string, elem(indexes, part))
@@ -684,7 +563,7 @@ defmodule Regex do
   end
 
   defp get_index(string, {pos, len}) do
-    <<_::size(pos)-binary, res::size(len)-binary, _::binary>> = string
+    <<_ :: size(pos)-binary, res :: size(len)-binary, _ :: binary>> = string
     res
   end
 
@@ -693,13 +572,16 @@ defmodule Regex do
   end
 
   defp get_indexes(string, [], arity) do
-    ["" | get_indexes(string, [], arity - 1)]
+    [""|get_indexes(string, [], arity - 1)]
   end
 
-  defp get_indexes(string, [h | t], arity) do
-    [get_index(string, h) | get_indexes(string, t, arity - 1)]
+  defp get_indexes(string, [h|t], arity) do
+    [get_index(string, h)|get_indexes(string, t, arity - 1)]
   end
 
+  {:ok, pattern} = :re.compile(~S"[.^$*+?()[{\\\|\s#]", [:unicode])
+  @escape_pattern pattern
+
   @doc ~S"""
   Escapes a string to be literally matched in a regex.
 
@@ -714,31 +596,7 @@ defmodule Regex do
   """
   @spec escape(String.t) :: String.t
   def escape(string) when is_binary(string) do
-    string
-    |> escape(_length = 0, string)
-    |> IO.iodata_to_binary
-  end
-
-  @escapable '.^$*+?()[]{}|#-\\\t\n\v\f\r\s'
-
-  defp escape(<<char, rest::binary>>, length, original) when char in @escapable do
-    escape_char(rest, length, original, char)
-  end
-
-  defp escape(<<_, rest::binary>>, length, original) do
-    escape(rest, length + 1, original)
-  end
-
-  defp escape(<<>>, _length, original) do
-    original
-  end
-
-  defp escape_char(<<rest::binary>>, 0, _original, char) do
-    [?\\, char | escape(rest, 0, rest)]
-  end
-
-  defp escape_char(<<rest::binary>>, length, original, char) do
-    [binary_part(original, 0, length), ?\\, char | escape(rest, 0, rest)]
+    :re.replace(string, @escape_pattern, "\\\\&", [:global, {:return, :binary}])
   end
 
   # Helpers
@@ -755,20 +613,13 @@ defmodule Regex do
 
   # Private Helpers
 
-  defp translate_options(<<?u, t::binary>>, acc), do: translate_options(t, [:unicode, :ucp | acc])
-  defp translate_options(<<?i, t::binary>>, acc), do: translate_options(t, [:caseless | acc])
-  defp translate_options(<<?x, t::binary>>, acc), do: translate_options(t, [:extended | acc])
-  defp translate_options(<<?f, t::binary>>, acc), do: translate_options(t, [:firstline | acc])
-  defp translate_options(<<?U, t::binary>>, acc), do: translate_options(t, [:ungreedy | acc])
-  defp translate_options(<<?s, t::binary>>, acc), do: translate_options(t, [:dotall, {:newline, :anycrlf} | acc])
-  defp translate_options(<<?m, t::binary>>, acc), do: translate_options(t, [:multiline | acc])
-
-  # TODO: Remove on 2.0
-  defp translate_options(<<?r, t::binary>>, acc) do
-    IO.warn "the /r modifier in regular expressions is deprecated, please use /U instead"
-    translate_options(t, [:ungreedy | acc])
-  end
-
+  defp translate_options(<<?u, t :: binary>>, acc), do: translate_options(t, [:unicode, :ucp|acc])
+  defp translate_options(<<?i, t :: binary>>, acc), do: translate_options(t, [:caseless|acc])
+  defp translate_options(<<?x, t :: binary>>, acc), do: translate_options(t, [:extended|acc])
+  defp translate_options(<<?f, t :: binary>>, acc), do: translate_options(t, [:firstline|acc])
+  defp translate_options(<<?r, t :: binary>>, acc), do: translate_options(t, [:ungreedy|acc])
+  defp translate_options(<<?s, t :: binary>>, acc), do: translate_options(t, [:dotall, {:newline, :anycrlf}|acc])
+  defp translate_options(<<?m, t :: binary>>, acc), do: translate_options(t, [:multiline|acc])
   defp translate_options(<<>>, acc), do: acc
   defp translate_options(rest, _acc), do: {:error, rest}
 end

lib/elixir/lib/set.ex

@@ -1,16 +1,49 @@
 defmodule Set do
   @moduledoc ~S"""
-  WARNING: this module is deprecated.
+  This module specifies the Set API expected to be
+  implemented by different representations.
 
-  Use the `MapSet` module instead.
+  It also provides functions that redirect to the
+  underlying Set, allowing a developer to work with
+  different Set implementations using one API.
+
+  To create a new set, use the `new` functions defined
+  by each set type:
+
+      HashSet.new  #=> creates an empty HashSet
+
+  In the examples below, `set_impl` means a specific
+  `Set` implementation, for example `HashSet`.
+
+  ## Protocols
+
+  Sets are required to implement both `Enumerable` and `Collectable`
+  protocols.
+
+  ## Match
+
+  Sets are required to implement all operations using the match (`===`)
+  operator.
   """
 
+  use Behaviour
+
   @type value :: any
-  @type values :: [value]
+  @type values :: [ value ]
   @type t :: map
 
-  # TODO: Remove by 2.0
-  # (hard-deprecated in elixir_dispatch)
+  defcallback new :: t
+  defcallback delete(t, value) :: t
+  defcallback difference(t, t) :: t
+  defcallback disjoint?(t, t) :: boolean
+  defcallback equal?(t, t) :: boolean
+  defcallback intersection(t, t) :: t
+  defcallback member?(t, value) :: boolean
+  defcallback put(t, value) :: t
+  defcallback size(t) :: non_neg_integer
+  defcallback subset?(t, t) :: boolean
+  defcallback to_list(t) :: list()
+  defcallback union(t, t) :: t
 
   defmacrop target(set) do
     quote do
@@ -23,10 +56,39 @@ defmodule Set do
     end
   end
 
+  @doc """
+  Deletes `value` from `set`.
+
+  ## Examples
+
+      iex> s = Enum.into([1, 2, 3], set_impl.new)
+      iex> Set.delete(s, 4) |> Enum.sort
+      [1, 2, 3]
+
+      iex> s = Enum.into([1, 2, 3], set_impl.new)
+      iex> Set.delete(s, 2) |> Enum.sort
+      [1, 3]
+
+  """
+  @spec delete(t, value) :: t
   def delete(set, value) do
     target(set).delete(set, value)
   end
 
+  @doc """
+  Returns a set that is `set1` without the members of `set2`.
+
+  Notice this function is polymorphic as it calculates the difference
+  for of any type. Each set implementation also provides a `difference`
+  function, but they can only work with sets of the same type.
+
+  ## Examples
+
+      iex> Set.difference(Enum.into([1,2], set_impl.new), Enum.into([2,3,4], set_impl.new)) |> Enum.sort
+      [1]
+
+  """
+  @spec difference(t, t) :: t
   def difference(set1, set2) do
     target1 = target(set1)
     target2 = target(set2)
@@ -34,12 +96,29 @@ defmodule Set do
     if target1 == target2 do
       target1.difference(set1, set2)
     else
-      Enumerable.reduce(set2, {:cont, set1}, fn v, acc ->
+      target2.reduce(set2, {:cont, set1}, fn v, acc ->
         {:cont, target1.delete(acc, v)}
       end) |> elem(1)
     end
   end
 
+  @doc """
+  Checks if `set1` and `set2` have no members in common.
+
+  Notice this function is polymorphic as it checks for disjoint sets of
+  any type. Each set implementation also provides a `disjoint?` function,
+  but they can only work with sets of the same type.
+
+  ## Examples
+
+      iex> Set.disjoint?(Enum.into([1, 2], set_impl.new), Enum.into([3, 4], set_impl.new))
+      true
+
+      iex> Set.disjoint?(Enum.into([1, 2], set_impl.new), Enum.into([2, 3], set_impl.new))
+      false
+
+  """
+  @spec disjoint?(t, t) :: boolean
   def disjoint?(set1, set2) do
     target1 = target(set1)
     target2 = target(set2)
@@ -47,7 +126,7 @@ defmodule Set do
     if target1 == target2 do
       target1.disjoint?(set1, set2)
     else
-      Enumerable.reduce(set2, {:cont, true}, fn member, acc ->
+      target2.reduce(set2, {:cont, true}, fn member, acc ->
         case target1.member?(set1, member) do
           false -> {:cont, acc}
           _     -> {:halt, false}
@@ -57,10 +136,28 @@ defmodule Set do
   end
 
   @doc false
+  @spec empty(t) :: t
   def empty(set) do
     target(set).empty(set)
   end
 
+  @doc """
+  Check if two sets are equal using `===`.
+
+  Notice this function is polymorphic as it compares sets of
+  any type. Each set implementation also provides an `equal?`
+  function, but they can only work with sets of the same type.
+
+  ## Examples
+
+      iex> Set.equal?(Enum.into([1, 2], set_impl.new), Enum.into([2, 1, 1], set_impl.new))
+      true
+
+      iex> Set.equal?(Enum.into([1, 2], set_impl.new), Enum.into([3, 4], set_impl.new))
+      false
+
+  """
+  @spec equal?(t, t) :: boolean
   def equal?(set1, set2) do
     target1 = target(set1)
     target2 = target(set2)
@@ -77,7 +174,23 @@ defmodule Set do
     end
   end
 
+  @doc """
+  Returns a set containing only members in common between `set1` and `set2`.
 
+  Notice this function is polymorphic as it calculates the intersection of
+  any type. Each set implementation also provides a `intersection` function,
+  but they can only work with sets of the same type.
+
+  ## Examples
+
+      iex> Set.intersection(Enum.into([1,2], set_impl.new), Enum.into([2,3,4], set_impl.new)) |> Enum.sort
+      [2]
+
+      iex> Set.intersection(Enum.into([1,2], set_impl.new), Enum.into([3,4], set_impl.new)) |> Enum.sort
+      []
+
+  """
+  @spec intersection(t, t) :: t
   def intersection(set1, set2) do
     target1 = target(set1)
     target2 = target(set2)
@@ -85,26 +198,77 @@ defmodule Set do
     if target1 == target2 do
       target1.intersection(set1, set2)
     else
-      Enumerable.reduce(set1, {:cont, target1.new}, fn v, acc ->
+      target1.reduce(set1, {:cont, target1.new}, fn v, acc ->
         {:cont, if(target2.member?(set2, v), do: target1.put(acc, v), else: acc)}
       end) |> elem(1)
     end
   end
 
+  @doc """
+  Checks if `set` contains `value`.
 
+  ## Examples
+
+      iex> Set.member?(Enum.into([1, 2, 3], set_impl.new), 2)
+      true
+
+      iex> Set.member?(Enum.into([1, 2, 3], set_impl.new), 4)
+      false
+
+  """
+  @spec member?(t, value) :: boolean
   def member?(set, value) do
     target(set).member?(set, value)
   end
 
+  @doc """
+  Inserts `value` into `set` if it does not already contain it.
 
+  ## Examples
+
+      iex> Set.put(Enum.into([1, 2, 3], set_impl.new), 3) |> Enum.sort
+      [1, 2, 3]
+
+      iex> Set.put(Enum.into([1, 2, 3], set_impl.new), 4) |> Enum.sort
+      [1, 2, 3, 4]
+
+  """
+  @spec put(t, value) :: t
   def put(set, value) do
     target(set).put(set, value)
   end
 
+  @doc """
+  Returns the number of elements in `set`.
+
+  ## Examples
+
+      iex> Set.size(Enum.into([1, 2, 3], set_impl.new))
+      3
+
+  """
+  @spec size(t) :: non_neg_integer
   def size(set) do
     target(set).size(set)
   end
 
+  @doc """
+  Checks if `set1`'s members are all contained in `set2`.
+
+  Notice this function is polymorphic as it checks the subset for
+  any type. Each set implementation also provides a `subset?` function,
+  but they can only work with sets of the same type.
+
+  ## Examples
+
+      iex> Set.subset?(Enum.into([1, 2], set_impl.new), Enum.into([1, 2, 3], set_impl.new))
+      true
+
+      iex> Set.subset?(Enum.into([1, 2, 3], set_impl.new), Enum.into([1, 2], set_impl.new))
+      false
+
+  """
+  @spec subset?(t, t) :: boolean
   def subset?(set1, set2) do
     target1 = target(set1)
     target2 = target(set2)
@@ -116,10 +280,34 @@ defmodule Set do
     end
   end
 
+  @doc """
+  Converts `set` to a list.
+
+  ## Examples
+
+      iex> set_impl.to_list(Enum.into([1, 2, 3], set_impl.new)) |> Enum.sort
+      [1,2,3]
+
+  """
+  @spec to_list(t) :: list
   def to_list(set) do
     target(set).to_list(set)
   end
 
+  @doc """
+  Returns a set containing all members of `set1` and `set2`.
+
+  Notice this function is polymorphic as it calculates the union of
+  any type. Each set implementation also provides a `union` function,
+  but they can only work with sets of the same type.
+
+  ## Examples
+
+      iex> Set.union(Enum.into([1,2], set_impl.new), Enum.into([2,3,4], set_impl.new)) |> Enum.sort
+      [1,2,3,4]
+
+  """
+  @spec union(t, t) :: t
   def union(set1, set2) do
     target1 = target(set1)
     target2 = target(set2)
@@ -127,14 +315,14 @@ defmodule Set do
     if target1 == target2 do
       target1.union(set1, set2)
     else
-      Enumerable.reduce(set2, {:cont, set1}, fn v, acc ->
+      target2.reduce(set2, {:cont, set1}, fn v, acc ->
         {:cont, target1.put(acc, v)}
       end) |> elem(1)
     end
   end
 
-  defp do_subset?(_target1, target2, set1, set2) do
-    Enumerable.reduce(set1, {:cont, true}, fn member, acc ->
+  defp do_subset?(target1, target2, set1, set2) do
+    target1.reduce(set1, {:cont, true}, fn member, acc ->
       case target2.member?(set2, member) do
         true -> {:cont, acc}
         _    -> {:halt, false}

lib/elixir/lib/stream/reducers.ex

@@ -1,216 +1,163 @@
 defmodule Stream.Reducers do
-  # Collection of reducers and utilities shared by Enum and Stream.
+  # Collection of reducers shared by Enum and Stream.
   @moduledoc false
 
-  def chunk_every(chunk_by, enumerable, count, step, leftover) do
-    limit = :erlang.max(count, step)
-    chunk_by.(enumerable, {[], 0}, fn entry, {acc_buffer, acc_count} ->
-      acc_buffer = [entry | acc_buffer]
-      acc_count = acc_count + 1
+  defmacro chunk(n, step, limit, f \\ nil) do
+    quote do
+      fn entry, acc(h, {buffer, count}, t) ->
+        buffer = [entry|buffer]
+        count  = count + 1
 
-      new_state =
-        if acc_count >= limit do
-          remaining = acc_count - step
-          {Enum.take(acc_buffer, remaining), remaining}
+        new =
+          if count >= unquote(limit) do
+            left = count - unquote(step)
+            {Enum.take(buffer, left), left}
+          else
+            {buffer, count}
+          end
+
+        if count == unquote(n) do
+          cont_with_acc(unquote(f), :lists.reverse(buffer), h, new, t)
         else
-          {acc_buffer, acc_count}
-        end
-
-      if acc_count == count do
-        {:cont, :lists.reverse(acc_buffer), new_state}
-      else
-        {:cont, new_state}
-      end
-    end, fn {acc_buffer, acc_count} ->
-      if leftover == :discard or acc_count == 0 do
-        {:cont, []}
-      else
-        {:cont, :lists.reverse(acc_buffer, Enum.take(leftover, count - acc_count)), []}
-      end
-    end)
-  end
-
-  def chunk_by(chunk_by, enumerable, fun) do
-    chunk_by.(enumerable, nil, fn
-      entry, nil ->
-        {:cont, {[entry], fun.(entry)}}
-      entry, {acc, value} ->
-        case fun.(entry) do
-          ^value -> {:cont, {[entry | acc], value}}
-          new_value -> {:cont, :lists.reverse(acc), {[entry], new_value}}
-        end
-    end, fn
-      nil -> {:cont, :done}
-      {acc, _value} -> {:cont, :lists.reverse(acc), :done}
-    end)
-  end
-
-  defmacro chunk_while(callback, fun \\ nil) do
-    quote do
-      fn entry, acc(head, acc, tail) ->
-        case unquote(callback).(entry, acc) do
-          {:cont, emit, acc} -> next_with_acc(unquote(fun), emit, head, acc, tail)
-          {:cont, acc} -> skip(acc(head, acc, tail))
-          {:halt, acc} -> {:halt, acc(head, acc, tail)}
+          {:cont, acc(h, new, t)}
         end
       end
     end
   end
 
-  defmacro dedup(callback, fun \\ nil) do
-    quote do
-      fn entry, acc(head, prev, tail) = acc ->
-        value = unquote(callback).(entry)
-        case prev do
-          {:value, ^value} -> skip(acc)
-          _ -> next_with_acc(unquote(fun), entry, head, {:value, value}, tail)
-        end
-      end
-    end
-  end
-
-  defmacro drop(fun \\ nil) do
+  defmacro chunk_by(callback, f \\ nil) do
     quote do
       fn
-        _entry, acc(head, amount, tail) when amount > 0 ->
-          skip(acc(head, amount - 1, tail))
-        entry, acc(head, amount, tail) ->
-          next_with_acc(unquote(fun), entry, head, amount, tail)
+        entry, acc(h, {buffer, value}, t) ->
+          new_value = unquote(callback).(entry)
+          if new_value == value do
+            {:cont, acc(h, {[entry|buffer], value}, t)}
+          else
+            cont_with_acc(unquote(f), :lists.reverse(buffer), h, {[entry], new_value}, t)
+          end
+        entry, acc(h, nil, t) ->
+          {:cont, acc(h, {[entry], unquote(callback).(entry)}, t)}
       end
     end
   end
 
-  defmacro drop_every(nth, fun \\ nil) do
+  defmacro drop(f \\ nil) do
     quote do
       fn
-        entry, acc(head, curr, tail) when curr in [unquote(nth), :first] ->
-          skip(acc(head, 1, tail))
-        entry, acc(head, curr, tail) ->
-          next_with_acc(unquote(fun), entry, head, curr + 1, tail)
+        _entry, acc(h, n, t) when n > 0 ->
+          {:cont, acc(h, n-1, t)}
+        entry, acc(h, n, t) ->
+          cont_with_acc(unquote(f), entry, h, n, t)
       end
     end
   end
 
-  defmacro drop_while(callback, fun \\ nil) do
+  defmacro drop_while(callback, f \\ nil) do
     quote do
-      fn entry, acc(head, bool, tail) = original ->
+      fn entry, acc(h, bool, t) = orig ->
         if bool and unquote(callback).(entry) do
-          skip(original)
+          {:cont, orig}
         else
-          next_with_acc(unquote(fun), entry, head, false, tail)
+          cont_with_acc(unquote(f), entry, h, false, t)
         end
       end
     end
   end
 
-  defmacro filter(callback, fun \\ nil) do
+  defmacro filter(callback, f \\ nil) do
     quote do
-      fn entry, acc ->
+      fn(entry, acc) ->
         if unquote(callback).(entry) do
-          next(unquote(fun), entry, acc)
+          cont(unquote(f), entry, acc)
         else
-          skip(acc)
+          {:cont, acc}
         end
       end
     end
   end
 
-  defmacro filter_map(filter, mapper, fun \\ nil) do
+  defmacro filter_map(filter, mapper, f \\ nil) do
     quote do
-      fn entry, acc ->
+      fn(entry, acc) ->
         if unquote(filter).(entry) do
-          next(unquote(fun), unquote(mapper).(entry), acc)
+          cont(unquote(f), unquote(mapper).(entry), acc)
         else
-          skip(acc)
+          {:cont, acc}
         end
       end
     end
   end
 
-  defmacro map(callback, fun \\ nil) do
+  defmacro map(callback, f \\ nil) do
     quote do
-      fn entry, acc ->
-        next(unquote(fun), unquote(callback).(entry), acc)
+      fn(entry, acc) ->
+        cont(unquote(f), unquote(callback).(entry), acc)
       end
     end
   end
 
-  defmacro map_every(nth, mapper, fun \\ nil) do
+  defmacro reject(callback, f \\ nil) do
     quote do
-      fn
-        entry, acc(head, curr, tail) when curr in [unquote(nth), :first] ->
-          next_with_acc(unquote(fun), unquote(mapper).(entry), head, 1, tail)
-        entry, acc(head, curr, tail) ->
-          next_with_acc(unquote(fun), entry, head, curr + 1, tail)
-      end
-    end
-  end
-
-  defmacro reject(callback, fun \\ nil) do
-    quote do
-      fn entry, acc ->
+      fn(entry, acc) ->
         unless unquote(callback).(entry) do
-          next(unquote(fun), entry, acc)
+          cont(unquote(f), entry, acc)
         else
-          skip(acc)
+          {:cont, acc}
         end
       end
     end
   end
 
-  defmacro scan2(callback, fun \\ nil) do
+  defmacro scan_2(callback, f \\ nil) do
     quote do
       fn
-        entry, acc(head, :first, tail) ->
-          next_with_acc(unquote(fun), entry, head, {:ok, entry}, tail)
-        entry, acc(head, {:ok, acc}, tail) ->
+        entry, acc(h, :first, t) ->
+          cont_with_acc(unquote(f), entry, h, {:ok, entry}, t)
+        entry, acc(h, {:ok, acc}, t) ->
           value = unquote(callback).(entry, acc)
-          next_with_acc(unquote(fun), value, head, {:ok, value}, tail)
+          cont_with_acc(unquote(f), value, h, {:ok, value}, t)
       end
     end
   end
 
-  defmacro scan3(callback, fun \\ nil) do
+  defmacro scan_3(callback, f \\ nil) do
     quote do
-      fn entry, acc(head, acc, tail) ->
+      fn(entry, acc(h, acc, t)) ->
         value = unquote(callback).(entry, acc)
-        next_with_acc(unquote(fun), value, head, value, tail)
+        cont_with_acc(unquote(f), value, h, value, t)
       end
     end
   end
 
-  defmacro take(fun \\ nil) do
+  defmacro take(f \\ nil) do
     quote do
-      fn entry, acc(head, curr, tail) = original ->
-        case curr do
-          0 ->
-            {:halt, original}
-          1 ->
-            {_, acc} = next_with_acc(unquote(fun), entry, head, 0, tail)
-            {:halt, acc}
-          _ ->
-            next_with_acc(unquote(fun), entry, head, curr - 1, tail)
+      fn(entry, acc(h, n, t) = orig) ->
+        if n >= 1 do
+          cont_with_acc(unquote(f), entry, h, n-1, t)
+        else
+          {:halt, orig}
         end
       end
     end
   end
 
-  defmacro take_every(nth, fun \\ nil) do
+  defmacro take_every(nth, f \\ nil) do
     quote do
       fn
-        entry, acc(head, curr, tail) when curr in [unquote(nth), :first] ->
-          next_with_acc(unquote(fun), entry, head, 1, tail)
-        entry, acc(head, curr, tail) ->
-          skip(acc(head, curr + 1, tail))
+        entry, acc(h, n, t) when n === :first
+                            when n === unquote(nth) ->
+          cont_with_acc(unquote(f), entry, h, 1, t)
+        entry, acc(h, n, t) ->
+          {:cont, acc(h, n+1, t)}
       end
     end
   end
 
-  defmacro take_while(callback, fun \\ nil) do
+  defmacro take_while(callback, f \\ nil) do
     quote do
-      fn entry, acc ->
+      fn(entry, acc) ->
         if unquote(callback).(entry) do
-          next(unquote(fun), entry, acc)
+          cont(unquote(f), entry, acc)
         else
           {:halt, acc}
         end
@@ -218,23 +165,23 @@ defmodule Stream.Reducers do
     end
   end
 
-  defmacro uniq_by(callback, fun \\ nil) do
+  defmacro uniq(callback, f \\ nil) do
     quote do
-      fn entry, acc(head, prev, tail) = original ->
+      fn(entry, acc(h, prev, t) = acc) ->
         value = unquote(callback).(entry)
-        if Map.has_key?(prev, value) do
-          skip(original)
+        if :lists.member(value, prev) do
+          {:cont, acc}
         else
-          next_with_acc(unquote(fun), entry, head, Map.put(prev, value, true), tail)
+          cont_with_acc(unquote(f), entry, h, [value|prev], t)
         end
       end
     end
   end
 
-  defmacro with_index(fun \\ nil) do
+  defmacro with_index(f \\ nil) do
     quote do
-      fn entry, acc(head, counter, tail) ->
-        next_with_acc(unquote(fun), {entry, counter}, head, counter + 1, tail)
+      fn(entry, acc(h, counter, t)) ->
+        cont_with_acc(unquote(f), {entry, counter}, h, counter + 1, t)
       end
     end
   end