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Merge pull request #3475 from siscia/fixIntTake
Ensure integer in guards in Enum/Stream.take
2016-02-21 21:33:30 +01:00 · 2015-07-12 17:58:49 +02:00 · 2015-07-12 17:40:16 +02:00 · 2015-06-29 09:56:28 +02:00 · 2015-06-25 18:01:05 +02:00 · 2015-06-25 16:49:30 +02:00
285 changed files with 9039 additions and 4255 deletions
@@ -1,6 +1,6 @@
 /.eunit
 /.release
-/docs
+/doc
 /ebin
 /lib/*/ebin/*
 /lib/*/tmp
@@ -8,3 +8,4 @@ notifications:
 otp_release:
  - 17.0
  - 17.1
+  - 17.3
@@ -1,5 +1,213 @@
 # Changelog

+## v1.0.5 (2015-06-29)
+
+* Enhancements
+  * [Elixir] Support 18.0
+  * [IEx] Rely only on loaded applications for autocompletion on IEx
+  * [Record] Expand attributes and macros in record extractor
+  * [String] `Optimize String.rstrip/1`
+  * [String] `Optimize String.downcase/1`
+  * [String] `Optimize String.upcase/1`
+
+* Bug fixes
+  * [EEx] Ensure blocks do not clobber EEx buffers
+  * [Enum] Ensure `Enum.take/2` does not consume one extra item when halting on the last emittable item
+  * [ExUnit] Fix `StringIO` processes leakage in the `ExUnit.CaptureIO` when there are errors inside the `capture_io` block
+  * [Float] Avoid rounding errors on `Float.parse/1`
+  * [GenEvent] Fix `GenEvent` detection of modules that aren't loaded
+  * [IO] Read 4K blocks instead of lines in `IO.binread/2`. This fixes a bug where CRLF were being ignored and is also going to improve performance
+  * [Logger] Handle `:undefined` arity in `Logger.Translator` (we get :undefined when a temporary worker of a `simple_one_for_one` supervisor crashes)
+  * [Mix] Ensure config is escaped before being injected into escripts. This fixes a bug where escripts failed to build when containing values like maps in config files
+  * [Mix] Ensure we properly underscore acronyms followed by paths, for example, `HTTP.Foo`
+  * [Stream] Ensure `Stream.flat_map/2` does not consume more items than necessary when piped to another `Stream.flat_map/2` that halts in the inner stream
+  * [Version] Fix `to_string` for versions with numeric pre releases
+
+## v1.0.4 (2015-04-07)
+
+* Enhancements
+  * [Elixir] Support Erlang 17.5 and 18.0-rc
+  * [Mix] Support "--search PATTERN" in "mix help"
+  * [Mix] Support `:start_permanent` that starts the application as permanent
+  * [Mix] Support `:build_embedded` that compile protocols, avoid symlinks and ensure protocols are loaded on boot
+  * [Mix] Make "mix app.start" public and support "--permanent" and "--temporary" options
+  * [URI] Speed decoding operations
+
+* Bug fixes
+  * [Elixir] Produce clearer error messages for syntax errors before a sigil
+  * [Elixir] Return value when matching on `_` in the last line of a block
+  * [Elixir] Ensure changes in child deps forces the parent to recompile
+  * [Kernel] Fix a bug where `=~/2` returned false when matching on an empty string. The current behaviour was changed to match the behaviour of `String.contains?/2`
+  * [Mix] Store relative paths in erlang manifests
+  * [Mix] Fix httpc proxy option profile for downloading hex and other safe packges
+  * [Mix] Fix missing behaviour warning when compiling Erlang modules
+
+## v1.0.3 (2015-02-12)
+
+* Enhancements
+  * [Elixir] Do not show exported vars warning
+  * [Elixir] Improve error messages when using invalid expressions inside maps
+  * [Elixir] Skip aliases and import warnings when code cannot compile
+  * [IEx] Improve autocompletion for Erlang/Elixir based on loaded applications
+  * [IO] Make `IO.ANSI.Docs` readable on white background
+  * [Mix] Provide clearer error message when updating archives on Windows
+  * [Mix] Don't go through hex.pm API server to install Hex
+
+* Bug fixes
+  * [Elixir] Ensure all Elixir applications work with code upgrades
+  * [Elixir] Don't leave spurious processes and stale data when the parallel compiler fails
+  * [Inspect] Keep original stacktrace on Inspect errors
+  * [IO] Fix `IO.ANSI.Docs` handling of `*`, `**`, `_` where they would be activated in the middle of words
+  * [Logger] Fix logging with `metadata[:function]`
+  * [Mix] Don't show hex update message on mix `local.hex`
+  * [Mix] Ensure tasks are properly underscored and camelized
+  * [Mix] Ensure Mix does not use ANSI escapes on Windows unless ANSI is enabled
+  * [Mix] Only shutdown Logger if the Mix application is being actually started
+  * [Mix] Ensure priv/include are copied on Windows even if source did not change
+  * [Mix] Ensure rebar dependencies work when user path has a space on Windows
+  * [Regex] Fix `Regex.replace/4` failures when the number of substitutions in pattern is more than the number of matches and support `\g{...}` patterns
+  * [String] Fix LFCR being treated as a grapheme instead of CRLF
+  * [URI] Do more strict matching on URI schema
+
+## v1.0.2 (2014-10-21)
+
+* Bug fixes
+  * [EEx] Remove invalid warning when attempting to inline code in EEx
+  * [EEx] Unify syntax errors to always include `file:line:`
+  * [IEx] Set null prompt function in dumb term mode
+  * [Kernel] Do not define an ets table with the same name as the module as it clashes with user code
+  * [Kernel] Fail compiling try expressions if they lack one of catch/after/rescue/else clauses
+  * [Kernel] Improve error messages when parsing fails on aliases
+  * [Kernel] Improve warnings coming from compile-time evaluation of arguments
+  * [String] Fix `String.replace/4` typespec
+
+## v1.0.1 (2014-10-07)
+
+* Enhancements
+  * [Mix] Add MIX_ENV output to archive.build (as on escript.build)
+
+* Bug fixes
+  * [CLI] Fix Elixir CLI when running on Cygwin
+  * [ExUnit] Include stacktraces in ExUnit timeouts
+  * [Mix] Load dependencies before `deps.check` compiles dependencies
+  * [Mix] Ensure `Mix.Config` is deep merged
+  * [Mix] Change version requirement in new apps to `~> MAJOR.MINOR`
+  * [Mix] Report correct location if `local.hex` fails and give higher priority to powershell install on Windows
+  * [Mix] Ensure `--elixirc-paths` option for `compile.elixir` is a subset of the project `:elixirc_paths` configuration and it does not remove skipped entries from the manifest
+  * [Mix] Ensure `compile.elixir` writes to manifest when files are removed
+  * [Mix] Ensure `compile.elixir` purges and deletes modules before compiling
+  * [Mix] Do not crash on malformed proxy env var
+  * [Stream] Ensure `chunk/4` works correctly when halted
+  * [System] Do not allow relative paths in `System.cmd/3` as documented
+  * [System] Fix `:stderr_to_stdout` option in `System.cmd/3`
+
+## v1.0.0 (2014-09-10)
+
+* Enhancements
+  * [Logger] Add `Logger.enable/1` and `Logger.disable/1`
+
+* Backwards incompatible changes
+  * [GenEvent] No longer support `{:swap_handler, ...}` as callback return value
+  * [List] `List.unzip/2` was removed
+
+## v1.0.0-rc2 (2014-09-07)
+
+* Enhancements
+  * [ExUnit] Print process mailbox on failing `assert_receive`
+  * [ExUnit] Tag all doctests with the `:doctest` tag
+  * [Kernel] Friendlier `unquote_splicing` error on inline quote
+  * [Kernel] Add `<~`, `~>`, `<<~`, `~>>`, `<~>`, `<|>` as operators
+  * [Mix] `mix deps.unlock` warns when given a missing dependency
+  * [Mix] Fetch hex using HTTPS
+
+* Bug fixes
+  * [File] Ensure `File.cwd` generates lowercase drive letters on Windows
+  * [GenEvent] Ensure the event manager does not crash on `:sys.replace_state/3`
+  * [GenEvent] Do not consider swap handlers to be failures in a stream
+  * [Logger] Fix `Logger.log/2` not to raise on Logger exit
+  * [Logger] Recompute sync/async mode on Logger configuration
+  * [System] Ensure `System.cwd` generates lowercase drive letters on Windows
+
+* Deprecations
+  * [GenEvent] The `:monitor` option in `add_handler/4` and `swap_handler/6` is deprecated in favor of `add_mon_handler/3` and `swap_mon_handler/5`
+
+* Backwards incompatible changes
+  * [Supervisor] Make `max_restarts` default to 3 (closer to upcoming Erlang defaults)
+
+## v1.0.0-rc1 (2014-08-30)
+
+* Enhancements
+  * [ExUnit] Add timeouts to tests (which is configurable via tags)
+  * [GenEvent] Add support for `GenEvent.ack_notify/2`
+  * [GenEvent] Add support for monitored handlers to `GenEvent.add_handler/4` that removes the drawbacks in the previous linked handlers
+  * [Logger] Allow any value that implements `String.Chars` to be logger
+  * [Logger] Allow `Logger.log/3` timeout to be configured
+  * [Mix] Add `--force` option to `mix local.rebar`
+  * [Mix] Fix `--no-color`/`--color` option for `mix test`
+  * [Mix] Add a `:language` option to improve the usability of Erlang projects using Mix
+  * [Mix] Accept wildcards on `Mix.Config.import_config/1`
+  * [Mix] Support protocol consolidation on escripts
+
+* Bug fixes
+  * [IEx] Do not print the underlying type for `@opaque` in the `t` helper
+  * [GenEvent] Do not allow a handler to be added more than once
+  * [GenServer] Do not treat bad arguments as exits in `GenServer.call/2`
+  * [GenServer] Do not deliver out of order messages on `GenServer.cast/2` on distributed mode
+  * [Mix] Do not pre-compile a Mix project if an alias was found
+  * [Mix] Properly handle compilation errors in the Erlang compiler
+  * [Mix] Always try to compile project if task cannot be found
+  * [Mix] Purge in memory modules before consolidating
+  * [Mix] Always compile a project if a task cannot be found
+
+* Deprecations
+  * [Collectable] Deprecate `Collectable.empty/1` and `Enum.traverse/2`
+  * [Integer] `odd?/1` and `even?/1` are deprecated in favor of `is_odd/1` and `is_even/1`
+  * [Kernel] `nil?/1` is deprecated in favor of `is_nil/1`
+  * [Kernel] `x.Alias` is deprecated in favor of an explicit `Module.concat/2`
+  * [Record] `record?/1` and `record?/2` are deprecated in favor of `is_record/1` and `is_record/2`
+  * [Stream] Returning `{item, acc} | nil` from `Stream.resource/2` is deprecated, instead return `{[item], acc} | {:halt, acc}` (similar to `Stream.transform/3`)
+
+* Backwards incompatible changes
+  * [GenEvent] `GenEvent.cancel_stream/1` no longer is
+  * [GenEvent] The `:mode` and `:duration` options are deprecated and no longer supported in `GenEvent.stream/2` (the mode is now a property of the sender)
+  * [GenEvent] The `:linked` option is deprecated and no longer supported in `GenEvent.add_handler/4` (check monitored handlers instead)
+
+## v0.15.1 (2014-08-10)
+
+* Enhancements
+  * [GenEvent] Support `:ack` mode for GenEvent streams
+  * [Inspect] Support `:base` option in `inspect/2` to choose the base (`:binary`, `:octal`, `:decimal` or `:hex`) numbers a printed
+  * [kernel] Print warnings when used ? with characters with escape codes
+  * [Logger] Add SASL log forwarding option to Logger
+  * [Logger] Add `$padlevel` to option Logger formatter
+  * [Logger] Backends receive the exact handler value when added, allowing a key to be passed for configuration lookup
+  * [Logger] Add `Logger.flush/0` to flush the Logger (useful for testing)
+  * [Logger] Persist backends dynamically added or removed via `add_backend/2` and `remove_backend/2`
+  * [Macro] Add `Macro.validate/1` to recursively check if a value is a valid quoted expression
+  * [Mix] Load mix deps only when there is a need to use them (this improves the timing for the majority of tasks in a Mix project)
+  * [Mix] Make the environment explicit on the success message generated after `escript.build` is invoked
+  * [Mix] Load `config/config.exs` inside escripts
+  * [Mix] Store and check Elixir version requirement for generated archives
+
+* Bug fixes
+  * [CLI] Fix shell bugs when running on Windows with Cygwin or MinGW
+  * [Kernel] Modules compiled by Elixir now report the correct beam location when `:code.which/1` is invoked. If the bytecode is only available in memory, `:code.which/1` returns `:in_memory`
+  * [Kernel] Do not expand args for unknown functions/macros
+  * [Kernel] Ensure `defstruct`, `@attr` inside and friends raise a nice error messages when values cannot be properly escaped
+  * [Kernel] Do not raise conflicts on imports used from inside quotes
+  * [Logger] Metadata is now correctly merged on each `Logger.metadata/1` call
+  * [Logger] Use the Logger PID on `:error_logger` wrapper to avoid race conditions on shutdown
+  * [Macro] Ensure bitstrings work with `Macro.escape/1`
+  * [Mix] Ensure aliases are invoked on umbrella recursive tasks
+  * [Mix] Leave it up to the application to start the Logger after compilation
+  * [Mix] Accept more forms of git versions (like "git version 1.9.3 (Apple Git-50)")
+  * [Path] Do not normalize paths in `Path.join/2` as normalization is beyond the scope of such function
+  * [URI] `to_string/1` now properly converts URI to strings when the schema is missing
+
+* Deprecations
+  * [Collectable] Having a function as collectable is deprecated
+  * [Module] `Module.function/3` is deprecated, please use `:erlang.make_fun/3` instead
+
 ## v0.15.0 (2014-08-02)

 * Enhancements
@@ -10,7 +10,7 @@ Use the issues tracker for:
 * [bug reports](#bugs-reports)
 * [submitting pull requests](#pull-requests)

-Please **do not** use the issues tracker for personal support requests nor feature requests. Support requests should be send to:
+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)
@@ -18,7 +18,7 @@ Please **do not** use the issues tracker for personal support requests nor featu

 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 issues tracker tidy and organized, making it useful
+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).
@@ -107,26 +107,6 @@ check [the official build status on Travis-CI](https://travis-ci.org/elixir-lang
 With tests running and passing, you are ready to contribute to Elixir and
 send your pull requests.

-### Building on Windows
-
-There are a few extra steps you'll need to take for contributing from Windows.
-Basically, once you have Erlang 17, Git, and MSYS from MinGW on your system,
-you're all set.  Specifically, here's what you need to do to get up and running:
-
-1. Install [Git](http://www.git-scm.com/download/win), 
-[Erlang](http://www.erlang.org/download.html), and the
-[MinGW Installation Manager](http://sourceforge.net/projects/mingw/files/latest/download?source=files).
-2. Use the MinGW Installation Manager to install the msys-bash, msys-make, and
-msys-grep packages.
-3. Add `;C:\Program Files (x86)\Git\bin;C:\Program Files\erl6.0\bin;C:\Program Files\erl6.0\erts-6.0\bin;C:\MinGW\msys\1.0\bin`
-to your "Path" environment variable .  (This is under Control Panel > System 
-and Security > System > Advanced system settings > Environment Variables > 
-System variables)
-
-You can now work in the Command Prompt similar to how you would on other OS'es,
-except for some things (like creating symlinks) you'll need to run the Command
-Prompt as an Administrator.
-
 ## Contributing Documentation

 Code documentation (`@doc`, `@moduledoc`, `@typedoc`) has a special convention:
@@ -1,4 +1,4 @@
-Copyright 2012-2013 Plataformatec.
+Copyright 2012 Plataformatec

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
@@ -1,4 +1,6 @@
 REBAR := rebar
+DOCS := v1.0
+CANONICAL := stable
 ELIXIRC := bin/elixirc --verbose --ignore-module-conflict
 ERLC := erlc -I lib/elixir/include
 ERL := erl -I lib/elixir/include -noshell -pa lib/elixir/ebin
@@ -86,7 +88,7 @@ $(KERNEL): lib/elixir/lib/*.ex lib/elixir/lib/*/*.ex lib/elixir/lib/*/*/*.ex
 unicode: $(UNICODE)
 $(UNICODE): lib/elixir/unicode/*
 	@ echo "==> unicode (compile)";
-	@ echo "This step can take up to a minute to compile in order to embed the Unicode database"
+	@ 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))
@@ -124,17 +126,18 @@ clean_exbeam:

 #==> Release 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")
+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 "v$(VERSION)" $(call LOGO_PATH) -o doc/$(2) -a http://elixir-lang.org/docs/$(CANONICAL)/$(2)/ -p http://elixir-lang.org/docs.html

 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)
+	$(Q) rm -rf doc
+	$(call COMPILE_DOCS,Elixir,elixir,Kernel)
+	$(call COMPILE_DOCS,EEx,eex,EEx)
+	$(call COMPILE_DOCS,Mix,mix,Mix)
+	$(call COMPILE_DOCS,IEx,iex,IEx)
+	$(call COMPILE_DOCS,ExUnit,ex_unit,ExUnit)
+	$(call COMPILE_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."
@@ -142,12 +145,21 @@ docs: compile ../ex_doc/bin/ex_doc

 release_zip: compile
 	rm -rf v$(VERSION).zip
-	zip -9 -r v$(VERSION).zip bin CHANGELOG.md LEGAL lib/*/ebin LICENSE README.md VERSION
+	zip -9 -r v$(VERSION).zip bin CHANGELOG.md LEGAL lib/*/ebin LICENSE Makefile README.md VERSION

 release_docs: docs
-	cd ../docs
-	rm -rf ../docs/master
-	mv docs ../docs/master
+	rm -rf ../docs/$(DOCS)/*/
+	mv doc/* ../docs/$(DOCS)
+
+# 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
+
+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

 #==> Tests tasks

@@ -183,7 +195,7 @@ test_stdlib: compile

 #==> Dialyzer tasks

-DIALYZER_OPTS = --no_check_plt --fullpath -Werror_handling -Wunmatched_returns -Wrace_conditions -Wunderspecs
+DIALYZER_OPTS = --no_check_plt --fullpath -Werror_handling -Wunmatched_returns -Wunderspecs
 PLT = .elixir.plt

 $(PLT):
@@ -12,6 +12,8 @@ If you want to contribute to Elixir or run it from source, clone this repository
    $ cd elixir
    $ make clean 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 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`.

 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.
@@ -1,28 +1,40 @@
 # Release process

+## All releases
+
 This document simply outlines the release process:

-1. Remove all `-dev` extension from versions (see below for all files)
+1. Ensure you are running on the oldest supported Erlang version

-2. Ensure CHANGELOG is updated and add current date
+2. Remove all `-dev` extension from versions (see below for all files)

-3. Commit changes above with title "Release vVERSION" and generate new tag
+3. Ensure CHANGELOG is updated and add current date

-4. Run `make clean test` to ensure all tests pass from scratch and the CI is green
+4. Commit changes above with title "Release vVERSION" and generate new tag

-5. Push master and the new tag
+5. Run `make clean test` to ensure all tests pass from scratch and the CI is green

-6. Release new docs with `make release_docs`, move docs to `docs/stable`
+6. Ensure minimum supported Hex works with new release (instructions upcoming)

-7. Release new zip with `make release_zip`, push new zip to GitHub Releases, name it Precompiled.zip
+7. Push branch and the new tag

-8. Fast-forward merge master into stable branch and push it
+8. Release new docs with `make release_docs`, copy docs to `docs/stable` if appropriate, and push

-9. After release, bump versions, add `-dev` back and commit
+9. Release new zip with `make release_zip`, push `Precompiled.zip` to GitHub Releases

-10. `make release_docs` once again and push it to `elixir-lang/docs`
+10. Add the release to `elixir.csv` file in `elixir-lang/elixir-lang.github.com`

-11. Add the release to `elixir.csv` file in `elixir-lang/elixir-lang.github.com`
+11. Build and push standalone Mix with `make publish_mix` (requires AWS credentials)
+
+## New vMAJOR.MINOR releases
+
+12. Create a new branch "vMAJOR.MINOR"
+
+13. Move docs generation to `docs/vMAJOR.MINOR` and copy them from `docs/stable`
+
+14. In master, bump versions, start new CHANGELOG, add `-dev` back and commit "Start vVERSION+1"
+
+15. `make release_docs` and push it to `elixir-lang/docs`

 ## Places where version is mentioned

@@ -1 +1 @@
-0.15.0
+1.0.5
@@ -80,7 +80,14 @@ done

 SELF=$(readlink_f "$0")
 SCRIPT_PATH=$(dirname "$SELF")
-if [ "$MODE" != "iex" ]; then ERL="$ERL -noshell -s elixir start_cli"; fi
+
+if [ "$OSTYPE" = "cygwin" ]; then SCRIPT_PATH=$(cygpath -m "$SCRIPT_PATH"); fi
+if [ "$MODE" != "iex" ]; then ERL="-noshell -s elixir start_cli $ERL"; fi
+
+# Check for terminal support
+if [ "$OS" != "Windows_NT" ]; then
+  if test -t 1 -a -t 2; then ERL="-elixir ansi_enabled true $ERL"; fi
+fi

 if [ -z "$ERL_PATH" ]; then
  if [ -f "$SCRIPT_PATH/../releases/RELEASES" ] && [ -f "$SCRIPT_PATH/erl" ]; then
@@ -48,6 +48,9 @@ set beforeExtra=
 rem Flag which determines whether or not to use werl vs erl
 set useWerl=0

+rem Designates which mode / Elixir component to run as
+set runMode="elixir"
+
 rem Recursive loop called for each parameter that parses the cmd line parameters
 :startloop
 set par="%1"
@@ -62,6 +65,7 @@ if "%par%"=="""" (
 )
 rem ******* EXECUTION OPTIONS **********************
 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) 
@@ -90,10 +94,13 @@ for  /d %%d in ("%originPath%..\lib\*.") do (
 )
 SETLOCAL disabledelayedexpansion
 :run
+IF NOT %runMode% == "iex" (
+  set beforeExtra=-s elixir start_cli %beforeExtra%
+)
 IF %useWerl% EQU 1 (
-    start werl.exe %ext_libs% %ELIXIR_ERL_OPTIONS% %parsErlang% -s elixir start_cli %beforeExtra% -extra %*
+  start werl.exe %ext_libs% %ELIXIR_ERL_OPTIONS% %parsErlang% %beforeExtra% -extra %*
 ) ELSE (
-    erl.exe %ext_libs% -noshell %ELIXIR_ERL_OPTIONS% %parsErlang% -s elixir start_cli %beforeExtra% -extra %*
+  erl.exe %ext_libs% -noshell %ELIXIR_ERL_OPTIONS% %parsErlang% %beforeExtra% -extra %*
 )
 :end
 endlocal
@@ -38,4 +38,6 @@ readlink_f () {

 SELF=$(readlink_f "$0")
 SCRIPT_PATH=$(dirname "$SELF")
-exec "$SCRIPT_PATH"/elixir --no-halt --erl "-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 "$@"
@@ -1,5 +1,9 @@
 defmodule EEx.SyntaxError do
-  defexception [:message]
+  defexception [:message, :file, :line]
+
+  def message(exception) do
+    "#{exception.file}:#{exception.line}: #{exception.message}"
+  end
 end

 defmodule EEx do
@@ -34,10 +38,9 @@ defmodule EEx do
  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.
+    * `: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.

  ## Engine
@@ -12,10 +12,14 @@ defmodule EEx.Compiler do
  def compile(source, opts) do
    file   = opts[:file] || "nofile"
    line   = opts[:line] || 1
-    tokens = EEx.Tokenizer.tokenize(source, line)
-    state  = %{engine: opts[:engine] || @default_engine,
-               file: file, line: line, quoted: [], start_line: nil}
-    generate_buffer(tokens, "", [], state)
+    case EEx.Tokenizer.tokenize(source, line) do
+      {:ok, tokens} ->
+        state = %{engine: opts[:engine] || @default_engine,
+                  file: file, line: line, quoted: [], start_line: nil}
+        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
@@ -51,16 +55,17 @@ defmodule EEx.Compiler do
    {buffer, t}
  end

-  defp generate_buffer([{:end_expr, line, _, chars}|_], _buffer, [], _state) do
-    raise EEx.SyntaxError, message: "unexpected token: #{inspect chars} at line #{inspect 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
    state.engine.handle_body(buffer)
  end

-  defp generate_buffer([], _buffer, _scope, _state) do
-    raise EEx.SyntaxError, message: "unexpected end of string. expecting a closing <% end %>."
+  defp generate_buffer([], _buffer, _scope, state) do
+    raise EEx.SyntaxError, message: "unexpected end of string, expected a closing '<% end %>'",
+                           file: state.file, line: state.line
  end

  # Creates a placeholder and wrap it inside the expression block
@@ -98,19 +98,16 @@ defmodule EEx.Engine do
  """
  def handle_expr(buffer, "=", expr) do
    quote do
-      tmp = unquote(buffer)
-      tmp <> (case unquote(expr) do
-        bin when is_binary(bin) -> bin
-        oth -> String.Chars.to_string(oth)
-      end)
+      tmp1 = unquote(buffer)
+      tmp1 <> String.Chars.to_string(unquote(expr))
    end
  end

  def handle_expr(buffer, "", expr) do
    quote do
-      tmp = unquote(buffer)
+      tmp2 = unquote(buffer)
      unquote(expr)
-      tmp
+      tmp2
    end
  end
 end
@@ -3,7 +3,8 @@ defmodule EEx.Tokenizer do

  @doc """
  Tokenizes the given char list or binary.
-  It returns 4 different types of tokens as result:
+
+  It returns {:ok, list} with the following tokens:

    * `{:text, contents}`
    * `{:expr, line, marker, contents}`
@@ -11,33 +12,43 @@ defmodule EEx.Tokenizer do
    * `{:middle_expr, line, marker, contents}`
    * `{:end_expr, line, marker, contents}`

+  Or `{:error, line, error}` in case of errors.
  """
  def tokenize(bin, line) when is_binary(bin) do
    tokenize(String.to_char_list(bin), line)
  end

  def tokenize(list, line) do
-    Enum.reverse(tokenize(list, line, [], []))
+    tokenize(list, line, [], [])
  end

  defp tokenize('<%%' ++ t, line, buffer, acc) do
-    {buffer, new_line, rest} = tokenize_expr t, line, [?%, ?<|buffer]
-    tokenize rest, new_line, [?>, ?%|buffer], acc
+    case expr(t, line, [?%, ?<|buffer]) do
+      {:error, _, _} = error -> error
+      {:ok, buffer, new_line, rest} ->
+        tokenize rest, new_line, [?>, ?%|buffer], acc
+    end
  end

  defp tokenize('<%#' ++ t, line, buffer, acc) do
-    {_, new_line, rest} = tokenize_expr t, line, []
-    tokenize rest, new_line, buffer, acc
+    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)
-    {expr, new_line, rest} = tokenize_expr t, line, []

-    token = token_name(expr)
-    acc   = tokenize_text(buffer, acc)
-    final = {token, line, marker, Enum.reverse(expr)}
-    tokenize rest, new_line, [], [final | acc]
+    case expr(t, line, []) do
+      {:error, _, _} = error -> error
+      {:ok, expr, new_line, rest} ->
+        token = token_name(expr)
+        acc   = tokenize_text(buffer, acc)
+        final = {token, line, marker, Enum.reverse(expr)}
+        tokenize rest, new_line, [], [final | acc]
+    end
  end

  defp tokenize('\n' ++ t, line, buffer, acc) do
@@ -49,7 +60,7 @@ defmodule EEx.Tokenizer do
  end

  defp tokenize([], _line, buffer, acc) do
-    tokenize_text(buffer, acc)
+    {:ok, Enum.reverse(tokenize_text(buffer, acc))}
  end

  # Retrieve marker for <%
@@ -64,20 +75,20 @@ defmodule EEx.Tokenizer do

  # Tokenize an expression until we find %>

-  defp tokenize_expr([?%, ?>|t], line, buffer) do
-    {buffer, line, t}
+  defp expr([?%, ?>|t], line, buffer) do
+    {:ok, buffer, line, t}
  end

-  defp tokenize_expr('\n' ++ t, line, buffer) do
-    tokenize_expr t, line + 1, [?\n|buffer]
+  defp expr('\n' ++ t, line, buffer) do
+    expr t, line + 1, [?\n|buffer]
  end

-  defp tokenize_expr([h|t], line, buffer) do
-    tokenize_expr t, line, [h|buffer]
+  defp expr([h|t], line, buffer) do
+    expr t, line, [h|buffer]
  end

-  defp tokenize_expr([], _line, _buffer) do
-    raise EEx.SyntaxError, message: "missing token: %>"
+  defp expr([], line, _buffer) do
+    {:error, line, "missing token '%>'"}
  end

  # Receive an expression content and check
@@ -5,23 +5,26 @@ defmodule EEx.TokenizerTest do
  require EEx.Tokenizer, as: T

  test "simple chars lists" do
-    assert T.tokenize('foo', 1) == [ {:text, 'foo'} ]
+    assert T.tokenize('foo', 1) == {:ok, [{:text, 'foo'}]}
  end

  test "simple strings" do
-    assert T.tokenize("foo", 1) == [ {:text, 'foo'} ]
+    assert T.tokenize("foo", 1) == {:ok, [{:text, 'foo'}]}
  end

  test "strings with embedded code" do
-    assert T.tokenize('foo <% bar %>', 1) == [ {:text, 'foo '}, {:expr, 1, "", ' bar '} ]
+    assert T.tokenize('foo <% bar %>', 1) ==
+           {:ok, [{:text, 'foo '}, {:expr, 1, "", ' bar '}]}
  end

  test "strings with embedded equals code" do
-    assert T.tokenize('foo <%= bar %>', 1) == [ {:text, 'foo '}, {:expr, 1, "=", ' bar '} ]
+    assert T.tokenize('foo <%= bar %>', 1) ==
+           {:ok, [{:text, 'foo '}, {:expr, 1, "=", ' bar '}]}
  end

  test "strings with more than one line" do
-    assert T.tokenize('foo\n<%= bar %>', 1) == [ {:text, 'foo\n'}, {:expr, 2, "=", ' bar '} ]
+    assert T.tokenize('foo\n<%= bar %>', 1) ==
+           {:ok, [{:text, 'foo\n'}, {:expr, 2, "=", ' bar '}]}
  end

  test "strings with more than one line and expression with more than one line" do
@@ -32,50 +35,50 @@ baz %>
 <% foo %>
 '''

-    assert T.tokenize(string, 1) == [
+    assert T.tokenize(string, 1) == {:ok, [
      {:text, 'foo '},
      {:expr, 1, "=", ' bar\n\nbaz '},
      {:text, '\n'},
      {:expr, 4, "", ' foo '},
      {:text, '\n'}
-    ] 
+    ]}
  end

  test "quotation" do
-    assert T.tokenize('foo <%% true %>', 1) == [
+    assert T.tokenize('foo <%% true %>', 1) == {:ok, [
      {:text, 'foo <% true %>'}
-    ]
+    ]}
  end

  test "quotation with do/end" do
-    assert T.tokenize('foo <%% true do %>bar<%% end %>', 1) == [
+    assert T.tokenize('foo <%% true do %>bar<%% end %>', 1) == {:ok, [
      {:text, 'foo <% true do %>bar<% end %>'}
-    ]
+    ]}
  end

  test "comments" do
-    assert T.tokenize('foo <%# true %>', 1) == [
+    assert T.tokenize('foo <%# true %>', 1) == {:ok, [
      {:text, 'foo '}
-    ]
+    ]}
  end

  test "comments with do/end" do
-    assert T.tokenize('foo <%# true do %>bar<%# end %>', 1) == [
+    assert T.tokenize('foo <%# true do %>bar<%# end %>', 1) == {:ok, [
      {:text, 'foo bar'}
-    ]
+    ]}
  end

  test "strings with embedded do end" do
-    assert T.tokenize('foo <% if true do %>bar<% end %>', 1) == [
+    assert T.tokenize('foo <% if true do %>bar<% end %>', 1) == {:ok, [
      {:text, 'foo '},
      {:start_expr, 1, "", ' if true do '},
      {:text, 'bar'},
      {:end_expr, 1, "", ' end '}
-    ]
+    ]}
  end

  test "strings with embedded -> end" do
-    assert T.tokenize('foo <% cond do %><% false -> %>bar<% true -> %>baz<% end %>', 1) == [
+    assert T.tokenize('foo <% cond do %><% false -> %>bar<% true -> %>baz<% end %>', 1) == {:ok, [
      {:text, 'foo '},
      {:start_expr, 1, "", ' cond do '},
      {:middle_expr, 1, "", ' false -> '},
@@ -83,23 +86,21 @@ baz %>
      {:middle_expr, 1, "", ' true -> '},
      {:text, 'baz'},
      {:end_expr, 1, "", ' end '}
-    ]
+    ]}
  end

  test "strings with embedded keywords blocks" do
-    assert T.tokenize('foo <% if true do %>bar<% else %>baz<% end %>', 1) == [
+    assert T.tokenize('foo <% if true do %>bar<% else %>baz<% end %>', 1) == {:ok, [
      {:text, 'foo '},
      {:start_expr, 1, "", ' if true do '},
      {:text, 'bar'},
      {:middle_expr, 1, "", ' else '},
      {:text, 'baz'},
      {:end_expr, 1, "", ' end '}
-    ]
+    ]}
  end

  test "raise syntax error when there is start mark and no end mark" do
-    assert_raise EEx.SyntaxError, "missing token: %>", fn ->
-      T.tokenize('foo <% :bar', 1)
-    end
+    assert T.tokenize('foo <% :bar', 1) == {:error, 1, "missing token '%>'"}
  end
 end
@@ -111,25 +111,25 @@ defmodule EExTest do
  end

  test "raises a syntax error when the token is invalid" do
-    assert_raise EEx.SyntaxError, "missing token: %>", fn ->
+    assert_raise EEx.SyntaxError, "nofile:1: missing token '%>'", fn ->
      EEx.compile_string "foo <%= bar"
    end
  end

  test "raises a syntax error when end expression is found without a start expression" do
-    assert_raise EEx.SyntaxError, "unexpected token: ' end ' at line 1",  fn ->
+    assert_raise EEx.SyntaxError, "nofile:1: unexpected token ' end '",  fn ->
      EEx.compile_string "foo <% end %>"
    end
  end

  test "raises a syntax error when start expression is found without an end expression" do
-    assert_raise EEx.SyntaxError, "unexpected end of string. expecting a closing <% end %>.", fn ->
-      EEx.compile_string "foo <% if true 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 "raises a syntax error when nested end expression is found without an start expression" do
-    assert_raise EEx.SyntaxError, "unexpected token: ' end ' at line 1", fn ->
+  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
@@ -252,7 +252,7 @@ Number <%= x %>
    assert_eval expected, string
  end

-  test "do not consider already finished functions" do
+  test "properly handle functions on the left side of clauses" do
    expected = """
 foo

@@ -287,6 +287,18 @@ foo
    assert_eval "\n\n  Good\n \n", string
  end

+  test "evaluates expressions with buffers" do
+    string = """
+    <%= 123 %>
+    <% if true do %>
+      <%= 456 %>
+    <% end %>
+    <%= 789 %>
+    """
+
+    assert_eval "123\n\n789\n", string
+  end
+
  test "for comprehensions" do
    string = """
    <%= for _name <- packages || [] do %>
@@ -201,7 +201,7 @@ defmodule Application do
  `:applications` in the `.app` file in case they were not previously
  started.
  """
-  @spec ensure_all_started(app, start_type) :: {:ok, [app]} | {:error, term}
+  @spec ensure_all_started(app, start_type) :: {:ok, [app]} | {:error, {app, term}}
  def ensure_all_started(app, type \\ :temporary) when is_atom(app) do
    :application.ensure_all_started(app, type)
  end
@@ -51,16 +51,7 @@ defmodule Code do
    :code.del_path(to_char_list(Path.expand path))
  end

-  @doc """
-  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
+  @doc false
  def readd_paths() do
    {pa, pz} = :elixir_code_server.call(:paths)
    :code.add_pathsa(pa)
@@ -260,7 +251,7 @@ defmodule Code do
  Accepts `relative_to` as an argument to tell where the file is located.

  While `load_file` loads a file and returns the loaded modules and their
-  byte code, `eval_file` simply evalutes the file contents and returns the
+  byte code, `eval_file` simply evaluates the file contents and returns the
  evaluation result and its bindings.
  """
  def eval_file(file, relative_to \\ nil) do
@@ -325,7 +316,7 @@ defmodule Code do
  Check `compiler_options/1` for more information.
  """
  def compiler_options do
-    :elixir_code_server.call :compiler_options
+    :elixir_config.get :compiler_options
  end

  @doc """
@@ -364,7 +355,8 @@ defmodule Code do
      bad = bad |> Keyword.keys |> Enum.join(", ")
      raise ArgumentError, message: "unknown compiler options: #{bad}"
    end
-    :elixir_code_server.cast {:compiler_options, opts}
+    update = &:orddict.merge(fn(_, _, value) -> value end, &1, opts)
+    :elixir_config.update :compiler_options, update
  end

  @doc """
@@ -8,12 +8,6 @@ defprotocol Collectable do
      iex> Enum.into([a: 1, b: 2], %{})
      %{a: 1, b: 2}

-  If a collection implements both `Enumerable` and `Collectable`, both
-  operations can be combined with `Enum.traverse/2`:
-
-      iex> Enum.traverse(%{a: 1, b: 2}, fn {k, v} -> {k, v * 2} end)
-      %{a: 2, b: 4}
-
  ## Why Collectable?

  The `Enumerable` protocol is useful to take values out of a collection.
@@ -27,25 +21,13 @@ defprotocol Collectable do
  shape where just the range limits are stored.

  The `Collectable` module was designed to fill the gap left by the
-  `Enumerable` protocol. It provides two functions: `into/1` and `empty/1`.
-
-  `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.
-
-  `empty/1` receives a collectable and returns an empty version of the
-  same collectable. By combining the enumerable functionality with `into/1`
-  and `empty/1`, one can, for example, implement a traversal mechanism.
+  `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.
  """

  @type command :: {:cont, term} | :done | :halt

-  @doc """
-  Receives a collectable structure and returns an empty one.
-  """
-  @spec empty(t) :: t
-  def empty(collectable)
-
  @doc """
  Returns a function that collects values alongside
  the initial accumulation value.
@@ -65,10 +47,6 @@ defprotocol Collectable do
 end

 defimpl Collectable, for: List do
-  def empty(_list) do
-    []
-  end
-
  def into(original) do
    {[], fn
      list, {:cont, x} -> [x|list]
@@ -79,10 +57,6 @@ defimpl Collectable, for: List do
 end

 defimpl Collectable, for: BitString do
-  def empty(_bitstring) do
-    ""
-  end
-
  def into(original) do
    {original, fn
      acc, {:cont, x} when is_bitstring(x) -> [acc|x]
@@ -92,21 +66,7 @@ defimpl Collectable, for: BitString do
  end
 end

-defimpl Collectable, for: Function do
-  def empty(function) do
-    function
-  end
-
-  def into(function) do
-    {function, function}
-  end
-end
-
 defimpl Collectable, for: Map do
-  def empty(_map) do
-    %{}
-  end
-
  def into(original) do
    {original, fn
      map, {:cont, {k, v}} -> :maps.put(k, v, map)
@@ -341,7 +341,7 @@ defmodule Enum do
    {_, {acc, {buffer, i}}} =
      Enumerable.reduce(coll, {:cont, {[], {[], 0}}}, R.chunk(n, step, limit))

-    if nil?(pad) || i == 0 do
+    if is_nil(pad) || i == 0 do
      :lists.reverse(acc)
    else
      buffer = :lists.reverse(buffer) ++ take(pad, n - i)
@@ -593,11 +593,11 @@ defmodule Enum do

  """
  @spec fetch(t, integer) :: {:ok, element} | :error
-  def fetch(collection, n) when is_list(collection) and n >= 0 do
+  def fetch(collection, n) when is_list(collection) and is_integer(n) and n >= 0 do
    do_fetch(collection, n)
  end

-  def fetch(collection, n) when n >= 0 do
+  def fetch(collection, n) when is_integer(n) and n >= 0 do
    res =
      Enumerable.reduce(collection, {:cont, 0}, fn(entry, acc) ->
        if acc == n do
@@ -613,7 +613,7 @@ defmodule Enum do
    end
  end

-  def fetch(collection, n) when n < 0 do
+  def fetch(collection, n) when is_integer(n) and n < 0 do
    do_fetch(reverse(collection), abs(n + 1))
  end

@@ -1261,6 +1261,15 @@ defmodule Enum do
    :lists.foldl(fun, acc, collection)
  end

+  def reduce(%{__struct__: _} = collection, acc, fun) do
+    Enumerable.reduce(collection, {:cont, acc},
+                      fn x, acc -> {:cont, fun.(x, acc)} end) |> elem(1)
+  end
+
+  def reduce(%{} = collection, acc, fun) do
+    :maps.fold(fn k, v, acc -> fun.({k, v}, acc) end, acc, collection)
+  end
+
  def reduce(collection, acc, fun) do
    Enumerable.reduce(collection, {:cont, acc},
                      fn x, acc -> {:cont, fun.(x, acc)} end) |> elem(1)
@@ -1722,23 +1731,23 @@ defmodule Enum do
    []
  end

-  def take(collection, count) when is_list(collection) and count > 0 do
+  def take(collection, count) when is_list(collection) and is_integer(count) and count > 0 do
    do_take(collection, count)
  end

-  def take(collection, count) when count > 0 do
+  def take(collection, count) when count > 0 and is_integer(count) do
    {_, {res, _}} =
      Enumerable.reduce(collection, {:cont, {[], count}}, fn(entry, {list, count}) ->
-        if count > 1 do
-          {:cont, {[entry|list], count - 1}}
-        else
-          {:halt, {[entry|list], count}}
+        case count do
+          0 -> {:halt, {list, count}}
+          1 -> {:halt, {[entry|list], count - 1}}
+          _ -> {:cont, {[entry|list], count - 1}}
        end
      end)
    :lists.reverse(res)
  end

-  def take(collection, count) when count < 0 do
+  def take(collection, count) when count < 0 and is_integer(count) do
    Stream.take(collection, count).({:cont, []}, &{:cont, [&1|&2]})
    |> elem(1) |> :lists.reverse
  end
@@ -1798,27 +1807,6 @@ defmodule Enum do
    reverse(collection) |> :lists.reverse
  end

-
-  @doc """
-  Traverses the given enumerable keeping its shape.
-
-  It also expects the enumerable to implement the `Collectable` protocol.
-
-  ## Examples
-
-      iex> Enum.traverse(%{a: 1, b: 2}, fn {k, v} -> {k, v * 2} end)
-      %{a: 2, b: 4}
-
-  """
-  @spec traverse(Enumerable.t, (term -> term)) :: Collectable.t
-  def traverse(collection, transform) when is_list(collection) do
-    :lists.map(transform, collection)
-  end
-
-  def traverse(collection, transform) do
-    into(collection, Collectable.empty(collection), transform)
-  end
-
  @doc """
  Enumerates the collection, removing all duplicated items.

@@ -564,6 +564,14 @@ defmodule BadStructError do
  end
 end

+defmodule BadMapError do
+  defexception [term: nil]
+
+  def message(exception) do
+    "expected a map, got: #{inspect(exception.term)}"
+  end
+end
+
 defmodule MatchError do
  defexception [term: nil]

@@ -613,12 +621,17 @@ defmodule BadArityError do
 end

 defmodule UndefinedFunctionError do
-  defexception [module: nil, function: nil, arity: nil]
+  defexception [module: nil, function: nil, arity: nil, self: false]

-  def message(exception) do
-    if exception.function do
-      formatted = Exception.format_mfa exception.module, exception.function, exception.arity
-      "undefined function: #{formatted}"
+  def message(%{function: function, module: module, arity: arity, self: self}) do
+    if function do
+      formatted = Exception.format_mfa module, function, arity
+      suffix = if self or is_nil(module) or :code.is_loaded(module) do
+        ""
+      else
+        " (module #{inspect module} is not available)"
+      end
+      "undefined function: #{formatted}" <> suffix
    else
      "undefined function"
    end
@@ -664,7 +677,12 @@ defmodule KeyError do
  defexception key: nil, term: nil

  def message(exception) do
-    "key #{inspect exception.key} not found in: #{inspect exception.term}"
+    msg = "key #{inspect exception.key} not found"
+    if exception.term != nil do
+      msg <> " in: #{inspect exception.term}"
+    else
+      msg
+    end
  end
 end

@@ -763,6 +781,20 @@ defmodule ErlangError do
    %MatchError{term: term}
  end

+  def normalize({:badmap, term}, _stacktrace) do
+    %BadMapError{term: term}
+  end
+
+  def normalize({:badkey, key}, stacktrace) do
+    term =
+      case stacktrace || :erlang.get_stacktrace do
+        [{:maps, :update, [_, _, map], _}|_] -> map
+        [{:maps, :get, [_, map], _}|_] -> map
+        _ -> nil
+      end
+    %KeyError{key: key, term: term}
+  end
+
  def normalize({:case_clause, term}, _stacktrace) do
    %CaseClauseError{term: term}
  end
@@ -772,8 +804,9 @@ defmodule ErlangError do
  end

  def normalize(:undef, stacktrace) do
-    {mod, fun, arity} = from_stacktrace(stacktrace || :erlang.get_stacktrace)
-    %UndefinedFunctionError{module: mod, function: fun, arity: arity}
+    stacktrace = stacktrace || :erlang.get_stacktrace
+    {mod, fun, arity} = from_stacktrace(stacktrace)
+    %UndefinedFunctionError{module: mod, function: fun, arity: arity, self: from_self(stacktrace)}
  end

  def normalize(:function_clause, stacktrace) do
@@ -800,4 +833,7 @@ defmodule ErlangError do
  defp from_stacktrace(_) do
    {nil, nil, nil}
  end
+
+  defp from_self([{module, _, _, _}, {module, _, _, _}|_]), do: true
+  defp from_self(_), do: false
 end
@@ -75,6 +75,12 @@ defmodule File do
  @type posix :: :file.posix()
  @type io_device :: :file.io_device()
  @type stat_options :: [time: :local | :universal | :posix]
+  @type mode :: :append | :binary | :compressed | :delayed_write | :exclusive |
+    :raw | :read | :read_ahead | :sync | :write |
+    {:encoding , :latin1 | :unicode | :utf16 | :utf32 | :utf8 |
+      {:utf16, :big | :little} | {:utf32, :big | :little}} |
+    {:read_ahead, pos_integer} |
+    {:delayed_write, non_neg_integer, non_neg_integer}

  @doc """
  Returns `true` if the path is a regular file.
@@ -126,12 +132,12 @@ defmodule File do
  Typical error reasons are:

    * `:eacces`  - missing search or write permissions for the parent
-                   directories of `path`
+       directories of `path`
    * `:eexist`  - there is already a file or directory named `path`
    * `:enoent`  - a component of `path` does not exist
    * `:enospc`  - there is a no space left on the device
    * `:enotdir` - a component of `path` is not a directory;
-                   on some platforms, `:enoent` is returned instead
+       on some platforms, `:enoent` is returned instead
  """
  @spec mkdir(Path.t) :: :ok | {:error, posix}
  def mkdir(path) do
@@ -612,7 +618,7 @@ defmodule File do

  Check `File.open/2` for other available options.
  """
-  @spec write(Path.t, iodata, list) :: :ok | {:error, posix}
+  @spec write(Path.t, iodata, [mode]) :: :ok | {:error, posix}
  def write(path, content, modes \\ []) do
    F.write_file(IO.chardata_to_string(path), content, modes)
  end
@@ -620,7 +626,7 @@ defmodule File do
  @doc """
  Same as `write/3` but raises an exception if it fails, returns `:ok` otherwise.
  """
-  @spec write!(Path.t, iodata, list) :: :ok | no_return
+  @spec write!(Path.t, iodata, [mode]) :: :ok | no_return
  def write!(path, content, modes \\ []) do
    path = IO.chardata_to_string(path)
    case F.write_file(path, content, modes) do
@@ -902,7 +908,8 @@ defmodule File do
      File.close(file)

  """
-  @spec open(Path.t, list) :: {:ok, io_device} | {:error, posix}
+  @spec open(Path.t, [mode | :ram]) :: {:ok, io_device} | {:error, posix}
+  @spec open(Path.t, (io_device -> res)) :: {:ok, res} | {:error, posix} when res: var
  def open(path, modes \\ [])

  def open(path, modes) when is_list(modes) do
@@ -935,7 +942,7 @@ defmodule File do
      end)

  """
-  @spec open(Path.t, list, (io_device -> res)) :: {:ok, res} | {:error, posix} when res: var
+  @spec open(Path.t, [mode | :ram], (io_device -> res)) :: {:ok, res} | {:error, posix} when res: var
  def open(path, modes, function) do
    case open(path, modes) do
      {:ok, device} ->
@@ -953,7 +960,7 @@ defmodule File do

  Returns the `io_device` otherwise.
  """
-  @spec open!(Path.t, list) :: io_device | no_return
+  @spec open!(Path.t, [mode]) :: io_device | no_return
  def open!(path, modes \\ []) do
    path = IO.chardata_to_string(path)
    case open(path, modes) do
@@ -968,7 +975,7 @@ defmodule File do

  Returns the function result otherwise.
  """
-  @spec open!(Path.t, list, (io_device -> res)) :: res | no_return when res: var
+  @spec open!(Path.t, [mode | :ram], (io_device -> res)) :: res | no_return when res: var
  def open!(path, modes, function) do
    path = IO.chardata_to_string(path)
    case open(path, modes, function) do
@@ -989,18 +996,27 @@ defmodule File do
  @spec cwd() :: {:ok, binary} | {:error, posix}
  def cwd() do
    case F.get_cwd do
-      {:ok, base} -> {:ok, IO.chardata_to_string(base)}
+      {:ok, base} -> {:ok, IO.chardata_to_string(fix_drive_letter(base))}
      {:error, _} = error -> error
    end
  end

+  defp fix_drive_letter([l, ?:, ?/ | rest] = original) when l in ?A..?Z do
+    case :os.type() do
+      {:win32, _} -> [l+?a-?A, ?:, ?/ | rest]
+      _ -> original
+    end
+  end
+
+  defp fix_drive_letter(original), do: original
+
  @doc """
  The same as `cwd/0`, but raises an exception if it fails.
  """
  @spec cwd!() :: binary | no_return
  def cwd!() do
-    case F.get_cwd do
-      {:ok, cwd} -> IO.chardata_to_string(cwd)
+    case cwd() do
+      {:ok, cwd} -> cwd
      {:error, reason} ->
          raise File.Error, reason: reason, action: "get current working directory"
    end
@@ -1124,7 +1140,7 @@ defmodule File do
  Returns `:ok` on success, or `{:error, reason}`
  on failure.
  """
-  @spec chmod(Path.t, integer) :: :ok | {:error, posix}
+  @spec chmod(Path.t, non_neg_integer) :: :ok | {:error, posix}
  def chmod(path, mode) do
    F.change_mode(IO.chardata_to_string(path), mode)
  end
@@ -1132,7 +1148,7 @@ defmodule File do
  @doc """
  Same as `chmod/2`, but raises an exception in case of failure. Otherwise `:ok`.
  """
-  @spec chmod!(Path.t, integer) :: :ok | no_return
+  @spec chmod!(Path.t, non_neg_integer) :: :ok | no_return
  def chmod!(path, mode) do
    path = IO.chardata_to_string(path)
    case chmod(path, mode) do
@@ -1147,7 +1163,7 @@ defmodule File do
  for a given `file`. Returns `:ok` on success, or
  `{:error, reason}` on failure.
  """
-  @spec chgrp(Path.t, integer) :: :ok | {:error, posix}
+  @spec chgrp(Path.t, non_neg_integer) :: :ok | {:error, posix}
  def chgrp(path, gid) do
    F.change_group(IO.chardata_to_string(path), gid)
  end
@@ -1155,7 +1171,7 @@ defmodule File do
  @doc """
  Same as `chgrp/2`, but raises an exception in case of failure. Otherwise `:ok`.
  """
-  @spec chgrp!(Path.t, integer) :: :ok | no_return
+  @spec chgrp!(Path.t, non_neg_integer) :: :ok | no_return
  def chgrp!(path, gid) do
    path = IO.chardata_to_string(path)
    case chgrp(path, gid) do
@@ -1170,7 +1186,7 @@ defmodule File do
  for a given `file`. Returns `:ok` on success,
  or `{:error, reason}` on failure.
  """
-  @spec chown(Path.t, integer) :: :ok | {:error, posix}
+  @spec chown(Path.t, non_neg_integer) :: :ok | {:error, posix}
  def chown(path, uid) do
    F.change_owner(IO.chardata_to_string(path), uid)
  end
@@ -1178,7 +1194,7 @@ defmodule File do
  @doc """
  Same as `chown/2`, but raises an exception in case of failure. Otherwise `:ok`.
  """
-  @spec chown!(Path.t, integer) :: :ok | no_return
+  @spec chown!(Path.t, non_neg_integer) :: :ok | no_return
  def chown!(path, uid) do
    path = IO.chardata_to_string(path)
    case chown(path, uid) do
@@ -28,75 +28,39 @@ defmodule Float do
  """
  @spec parse(binary) :: {float, binary} | :error
  def parse("-" <> binary) do
-    case parse_unsign(binary) do
+    case parse_unsigned(binary) do
      :error -> :error
      {number, remainder} -> {-number, remainder}
    end
  end

  def parse(binary) do
-    parse_unsign(binary)
+    parse_unsigned(binary)
  end

-  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(<<char, rest::binary>>) when char in ?0..?9, do:
+    parse_unsigned(rest, false, false, <<char>>)

-  # 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(binary) when is_binary(binary), do:
+    :error

-  defp parse_unsign(rest, int) do
-    {:erlang.float(int), rest}
-  end
+  defp parse_unsigned(<<char, rest :: binary>>, dot?, e?, acc) when char in ?0..?9, do:
+    parse_unsigned(rest, dot?, e?, <<acc::binary, char>>)

-  # 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(<<?., char, rest :: binary>>, false, false, acc) when char in ?0..?9, do:
+    parse_unsigned(rest, true, false, <<acc::binary, ?., char>>)

-  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(<<?e, char, rest :: binary>>, dot?, false, acc) when char in ?0..?9, do:
+    parse_unsigned(rest, true, true, <<add_dot(acc, dot?)::binary, ?e, char>>)

-  defp parse_unsign(bitstring, float, decimal, int) do
-    {floatify(int, float, decimal), bitstring}
-  end
+  defp parse_unsigned(<<?e, ?-, char, rest :: binary>>, dot?, false, acc) when char in ?0..?9, do:
+    parse_unsigned(rest, true, true, <<add_dot(acc, dot?)::binary, ?e, ?-, char>>)

-  defp floatify(int, float, decimal, exponential \\ 0) do
-    multiplier = if int < 0, do: -1.0, else: 1.0
+  defp parse_unsigned(rest, dot?, _e?, acc), do:
+    {:erlang.binary_to_float(add_dot(acc, dot?)), rest}

-    # 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
+  defp add_dot(acc, true),  do: acc
+  defp add_dot(acc, false), do: acc <> ".0"

  @doc """
  Rounds a float to the largest integer less than or equal to `num`.
@@ -0,0 +1,168 @@
+defmodule GenEvent.Stream do
+  @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__{
+               manager: GenEvent.manager,
+               timeout: timeout}
+
+  @doc false
+  def init({_pid, _ref} = state) do
+    {:ok, state}
+  end
+
+  @doc false
+  def handle_event(event, _state) do
+    exit({:bad_event, event})
+  end
+
+  @doc false
+  def handle_call(msg, _state) do
+    exit({:bad_call, msg})
+  end
+
+  @doc false
+  def handle_info(_msg, state) do
+    {:ok, state}
+  end
+
+  @doc false
+  def terminate(_reason, _state) do
+    :ok
+  end
+
+  @doc false
+  def code_change(_old, state, _extra) do
+    {:ok, state}
+  end
+end
+
+defimpl Enumerable, for: GenEvent.Stream do
+  def reduce(stream, acc, fun) do
+    start_fun = fn() -> start(stream) end
+    next_fun = &next(stream, &1)
+    stop_fun = &stop(stream, &1)
+    Stream.resource(start_fun, next_fun, stop_fun).(acc, wrap_reducer(fun))
+  end
+
+  def count(_stream) do
+    {:error, __MODULE__}
+  end
+
+  def member?(_stream, _item) do
+    {:error, __MODULE__}
+  end
+
+  defp wrap_reducer(fun) do
+    fn
+      {:ack, manager, ref, event}, acc ->
+        send manager, {ref, :ok}
+        fun.(event, acc)
+      {:async, _manager, _ref, event}, acc ->
+        fun.(event, acc)
+      {:sync, manager, ref, event}, acc ->
+        try do
+          fun.(event, acc)
+        after
+          send manager, {ref, :ok}
+        end
+    end
+  end
+
+  defp start(%{manager: manager} = stream) do
+    try do
+      {:ok, {pid, ref}} = :gen.call(manager, self(),
+                                    {:add_process_handler, self(), self()}, :infinity)
+      mon_ref = Process.monitor(pid)
+      {pid, ref, mon_ref}
+    catch
+      :exit, reason -> exit({reason, {__MODULE__, :start, [stream]}})
+    end
+  end
+
+  defp next(%{timeout: timeout} = stream, {pid, ref, mon_ref} = acc) do
+    self = self()
+
+    receive do
+      # Got an async event.
+      {_from, {^pid, ^ref}, {:notify, event}} ->
+        {[{:async, pid, ref, event}], acc}
+
+      # Got a sync event.
+      {_from, {^pid, ^ref}, {:sync_notify, event}} ->
+        {[{:sync, pid, ref, event}], acc}
+
+      # Got an ack event.
+      {_from, {^pid, ^ref}, {:ack_notify, event}} ->
+        {[{:ack, pid, ref, event}], acc}
+
+      # The handler was removed. Stop iteration, resolve the
+      # event later. We need to demonitor now, otherwise DOWN
+      # appears with higher priority in the shutdown process.
+      {:gen_event_EXIT, {^pid, ^ref}, _reason} = event ->
+        Process.demonitor(mon_ref, [:flush])
+        send(self, event)
+        {:halt, {:removed, acc}}
+
+      # The manager died. Stop iteration, resolve the event later.
+      {:DOWN, ^mon_ref, _, _, _} = event ->
+        send(self, event)
+        {:halt, {:removed, acc}}
+    after
+      timeout ->
+        exit({:timeout, {__MODULE__, :next, [stream, acc]}})
+    end
+  end
+
+  # If we reach this branch, we know the handler was already
+  # removed, so we don't trigger a request for doing so.
+  defp stop(stream, {:removed, {pid, ref, mon_ref} = acc}) do
+    case wait_for_handler_removal(pid, ref, mon_ref) do
+      :ok ->
+        flush_events(ref)
+      {:error, reason} ->
+        exit({reason, {__MODULE__, :stop, [stream, acc]}})
+    end
+  end
+
+  # 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
+    _ = 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}
+          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
+  end
+
+  defp flush_events(ref) do
+    receive do
+      {_from, {_pid, ^ref}, {notify, _event}} when notify in [:notify, :ack_notify, :sync_notify] ->
+        flush_events(ref)
+    after
+      0 -> :ok
+    end
+  end
+end
@@ -349,18 +349,57 @@ defmodule GenServer do
  """
  @spec call(server, term, timeout) :: term
  def call(server, request, timeout \\ 5000) do
-    :gen_server.call(server, request, timeout)
+    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 returns `:ok` immediately, regardless of whether the
-  destination node or server does exists. `handle_cast/2` will be called on the
-  server to handle the request.
+  This function returns `:ok` immediately, regardless of
+  whether the destination node or server does exists, unless
+  the server is specified as an atom.
+
+  `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
+  would be sent by another process, which could cause
+  messages to arrive out of order.
  """
  @spec cast(server, term) :: :ok
-  defdelegate cast(server, request), to: :gen_server
+  def cast(server, request)
+
+  def cast({:global, name}, request) do
+    try do
+      :global.send(name, cast_msg(request))
+      :ok
+    catch
+      _, _ -> :ok
+    end
+  end
+
+  def cast({:via, mod, name}, request) do
+    try do
+      mod.send(name, cast_msg(request))
+      :ok
+    catch
+      _, _ -> :ok
+    end
+  end
+
+  def cast({name, node}, request) when is_atom(name) and is_atom(node),
+    do: do_send({name, node}, cast_msg(request))
+
+  def cast(dest, request) when is_atom(dest) or is_pid(dest),
+    do: do_send(dest, cast_msg(request))

  @doc """
  Casts all servers locally registered as `name` at the specified nodes.
@@ -371,8 +410,19 @@ defmodule GenServer do
  See `multi_call/4` for more information.
  """
  @spec abcast([node], name :: atom, term) :: :abcast
-  def abcast(nodes \\ nodes(), name, request) do
-    :gen_server.abcast(nodes, name, request)
+  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
+  end
+
+  defp cast_msg(req) do
+    {:"$gen_cast", req}
+  end
+
+  defp do_send(dest, msg) do
+    send(dest, msg)
+    :ok
  end

  @doc """
@@ -271,25 +271,6 @@ defimpl Inspect, for: BitString do
 end

 defimpl Inspect, for: List do
-  @doc ~S"""
-  Represents a list, checking if it can be printed or not.
-  If so, a single-quoted representation is returned,
-  otherwise the brackets syntax is used. Keywords are
-  printed in keywords syntax.
-
-  ## Examples
-
-      iex> inspect('bar')
-      "'bar'"
-
-      iex> inspect([0|'bar'])
-      "[0, 98, 97, 114]"
-
-      iex> inspect([:foo,:bar])
-      "[:foo, :bar]"
-
-  """
-
  def inspect([], _opts), do: "[]"

  def inspect(thing, %Inspect.Opts{char_lists: lists} = opts) do
@@ -377,8 +358,28 @@ defimpl Inspect, for: Map do
 end

 defimpl Inspect, for: Integer do
-  def inspect(thing, _opts) do
-    Integer.to_string(thing)
+  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
+    case base do
+      :binary  -> 2
+      :decimal -> 10
+      :octal   -> 8
+      :hex     -> 16
+    end
+  end
+
+  defp prepend_prefix(value, :decimal), do: value
+  defp prepend_prefix(value, base) do
+    prefix = case base do
+      :binary -> "0b"
+      :octal  -> "0o"
+      :hex    -> "0x"
+    end
+    prefix <> value
  end
 end

@@ -31,6 +31,10 @@ defmodule Inspect.Opts do

    * `:width` - defaults to the 80 characters, used when pretty is true or
      when printing to IO devices.
+
+    * `:base` - print integers as :binary, :octal, :decimal, or :hex, defaults
+      to :decimal
+
  """

  defstruct structs: true,
@@ -38,6 +42,7 @@ defmodule Inspect.Opts do
            char_lists: :infer,
            limit: 50,
            width: 80,
+            base: :decimal,
            pretty: false

  @type t :: %__MODULE__{
@@ -46,6 +51,7 @@ defmodule Inspect.Opts do
               char_lists: :infer | :as_lists | :as_char_lists,
               limit: pos_integer,
               width: pos_integer | :infinity,
+               base: :decimal | :binary | :hex | :octal,
               pretty: boolean}
 end

@@ -179,6 +185,8 @@ defmodule Inspect.Algebra 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
@@ -192,9 +200,10 @@ defmodule Inspect.Algebra do
              Process.put(:inspect_trap, true)
              res = Inspect.Map.inspect(map, opts)
              formatted = IO.iodata_to_binary(format(res, :infinity))
-              raise ArgumentError,
+              reraise ArgumentError,
                "Got #{inspect e.__struct__} with message " <>
-                "\"#{Exception.message(e)}\" while inspecting #{formatted}"
+                "\"#{Exception.message(e)}\" while inspecting #{formatted}",
+                stacktrace
            after
              Process.delete(:inspect_trap)
            end
@@ -428,24 +437,17 @@ 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(binary, [any], binary, integer | :infinity, (term -> t), binary) :: t
+  @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
-    if is_integer(opts) do
-      IO.write :stderr, "Inspect.Algebra.surround_many/6 with an integer limit is deprecated, " <>
-                        "please pass Inspect.Opts instead\n#{Exception.format_stacktrace}" 
-      old_surround_many(left, docs, right, opts, fun, separator)
-    else
-      do_surround_many(left, docs, right, opts.limit, opts, fun, separator)
-    end
+    do_surround_many(left, docs, right, opts.limit, opts, fun, separator)
  end

-  def do_surround_many(left, [], right, _, _opts, _fun, _) do
+  defp do_surround_many(left, [], right, _, _opts, _fun, _) do
    concat(left, right)
  end

-  def do_surround_many(left, docs, right, limit, _opts, fun, sep) do
+  defp do_surround_many(left, docs, right, limit, _opts, fun, sep) do
    surround(left, do_surround_many(docs, limit, _opts, fun, sep), right)
  end

@@ -473,36 +475,6 @@ defmodule Inspect.Algebra do
    )
  end

-  def old_surround_many(left, [], right, _, _fun, _) do
-    concat(left, right)
-  end
-
-  def old_surround_many(left, docs, right, limit, fun, sep) do
-    surround(left, old_surround_many(docs, limit, fun, sep), right)
-  end
-
-  defp old_surround_many(_, 0, _fun, _sep) do
-    "..."
-  end
-
-  defp old_surround_many([h], _limit, fun, _sep) do
-    fun.(h)
-  end
-
-  defp old_surround_many([h|t], limit, fun, sep) when is_list(t) do
-    glue(
-      concat(fun.(h), sep),
-      old_surround_many(t, decrement(limit), fun, sep)
-    )
-  end
-
-  defp old_surround_many([h|t], _limit, fun, _sep) do
-    glue(
-      concat(fun.(h), @tail_separator),
-      fun.(t)
-    )
-  end
-
  defp decrement(:infinity), do: :infinity
  defp decrement(counter),   do: counter - 1

@@ -513,16 +485,11 @@ defmodule Inspect.Algebra do
  and returns an IO data representation of the best layout for the
  document to fit in the given width.
  """
-  @spec format(t, non_neg_integer | :infinity) :: binary
+  @spec format(t, non_neg_integer | :infinity) :: iodata
  def format(d, w) do
    format(w, 0, [{0, default_mode(w), doc_group(d)}])
  end

-  @doc false
-  def pretty(d, w) do
-    format(d, w) |> IO.iodata_to_binary
-  end
-
  defp default_mode(:infinity), do: :flat
  defp default_mode(_),         do: :break

@@ -9,9 +9,10 @@ defmodule Integer do
  Determines if an integer is odd.

  Returns `true` if `n` is an odd number, otherwise `false`.
-  Implemented as a macro so it is allowed in guard clauses.
+
+  Allowed in guard clauses.
  """
-  defmacro odd?(n) do
+  defmacro is_odd(n) do
    quote do: (unquote(n) &&& 1) == 1
  end

@@ -19,9 +20,10 @@ defmodule Integer do
  Determines if an integer is even.

  Returns `true` if `n` is an even number, otherwise `false`.
-  Implemented as a macro so it is allowed in guard clauses.
+
+  Allowed in guard clauses.
  """
-  defmacro even?(n) do
+  defmacro is_even(n) do
    quote do: (unquote(n) &&& 1) == 0
  end

@@ -99,7 +101,7 @@ defmodule Integer do
      "64"

  """
-  @spec to_string(integer, pos_integer) :: String.t
+  @spec to_string(integer, 2..36) :: String.t
  def to_string(some_integer, base) do
    :erlang.integer_to_binary(some_integer, base)
  end
@@ -132,7 +134,7 @@ defmodule Integer do
      '3FF'

  """
-  @spec to_char_list(integer, pos_integer) :: char_list
+  @spec to_char_list(integer, 2..36) :: char_list
  def to_char_list(number, base) do
    :erlang.integer_to_list(number, base)
  end
@@ -123,8 +123,9 @@ defmodule IO do
    end
  end

+  @read_all_size 4096
  defp do_binread_all(mapped_dev, acc) do
-    case :file.read_line(mapped_dev) do
+    case :file.read(mapped_dev, @read_all_size) do
      {:ok, data} -> do_binread_all(mapped_dev, acc <> data)
      :eof -> acc
      other -> other
@@ -180,7 +181,7 @@ defmodule IO do
  Inspects and writes the given argument to the device.

  It enables pretty printing by default with width of
-  80 characters. Th width can be changed by explicitly
+  80 characters. The width can be changed by explicitly
  passing the `:width` option.

  ## Examples
@@ -394,11 +395,11 @@ defmodule IO do
  def each_stream(device, what) do
    case read(device, what) do
      :eof ->
-        nil
+        {:halt, device}
      {:error, reason} ->
        raise IO.StreamError, reason: reason
      data ->
-        {data, device}
+        {[data], device}
    end
  end

@@ -406,11 +407,11 @@ defmodule IO do
  def each_binstream(device, what) do
    case binread(device, what) do
      :eof ->
-        nil
+        {:halt, device}
      {:error, reason} ->
        raise IO.StreamError, reason: reason
      data ->
-        {data, device}
+        {[data], device}
    end
  end

@@ -7,10 +7,6 @@ defmodule IO.ANSI.Sequence do
        "\e[#{unquote(code)}#{unquote(terminator)}"
      end

-      defp escape_sequence(unquote(Atom.to_char_list(name))) do
-        unquote(name)()
-      end
-
      defp format_sequence(unquote(name)) do
        unquote(name)()
      end
@@ -32,25 +28,17 @@ defmodule IO.ANSI do
  @typep ansilist :: maybe_improper_list(char() | ansicode() | binary() | ansilist(), binary() | ansicode() | [])
  @type  ansidata :: ansilist() | ansicode() | binary()

-  @doc false
-  def terminal?(device \\ :erlang.group_leader) do
-    !match?({:win32, _}, :os.type()) and
-      match?({:ok, _}, :io.columns(device))
-  end
-
  @doc """
  Checks if ANSI coloring is supported and enabled on this machine.

-  By default, ANSI is only enabled on UNIX machines. Enabling or
-  disabling ANSI escapes can be done by configuring the
-  `:ansi_enabled` value in the `:elixir` application.
+  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
+  both `stdout` and `stderr` are terminals.
  """
  @spec enabled? :: boolean
  def enabled? do
-    case Application.fetch_env(:elixir, :ansi_enabled) do
-      {:ok, boolean} when is_boolean(boolean) -> boolean
-      :error -> !match?({:win32, _}, :os.type())
-    end
+    Application.get_env(:elixir, :ansi_enabled, false)
  end

  @doc "Resets all attributes"
@@ -144,10 +132,6 @@ defmodule IO.ANSI do
  @doc "Clear screen"
  defsequence :clear, "2", "J"

-  defp escape_sequence(other) do
-    raise ArgumentError, "invalid ANSI sequence specification: #{other}"
-  end
-
  defp format_sequence(other) do
    raise ArgumentError, "invalid ANSI sequence specification: #{other}"
  end
@@ -222,56 +206,4 @@ defmodule IO.ANSI do
  defp do_format([], [], acc, _emit, _append_reset) do
    acc
  end
-
-  @doc false
-  def escape(string, emit \\ terminal?) when is_binary(string) and is_boolean(emit) do
-    {rendered, emitted} = do_escape(string, emit, false, nil, [])
-    if emitted do
-      rendered <> reset
-    else
-      rendered
-    end
-  end
-
-  @doc false
-  def escape_fragment(string, emit \\ terminal?) when is_binary(string) and is_boolean(emit) do
-    {escaped, _emitted} = do_escape(string, emit, false, nil, [])
-    escaped
-  end
-
-  defp do_escape(<<?}, t :: binary>>, emit, emitted, buffer, acc) when is_list(buffer) do
-    sequences =
-      buffer
-      |> Enum.reverse()
-      |> :string.tokens(',')
-      |> Enum.map(&(&1 |> :string.strip |> escape_sequence))
-      |> Enum.reverse()
-
-    if emit and sequences != [] do
-      do_escape(t, emit, true, nil, sequences ++ acc)
-    else
-      do_escape(t, emit, emitted, nil, acc)
-    end
-  end
-
-  defp do_escape(<<h, t :: binary>>, emit, emitted, buffer, acc) when is_list(buffer) do
-    do_escape(t, emit, emitted, [h|buffer], acc)
-  end
-
-  defp do_escape(<<>>, _emit, _emitted, buffer, _acc) when is_list(buffer) do
-    buffer = IO.iodata_to_binary Enum.reverse(buffer)
-    raise ArgumentError, "missing } for escape fragment #{buffer}"
-  end
-
-  defp do_escape(<<?%, ?{, t :: binary>>, emit, emitted, nil, acc) do
-    do_escape(t, emit, emitted, [], acc)
-  end
-
-  defp do_escape(<<h, t :: binary>>, emit, emitted, nil, acc) do
-    do_escape(t, emit, emitted, nil, [h|acc])
-  end
-
-  defp do_escape(<<>>, _emit, emitted, nil, acc) do
-    {IO.iodata_to_binary(Enum.reverse(acc)), emitted}
-  end
 end
@@ -25,10 +25,10 @@ defmodule IO.ANSI.Docs do
    [enabled:           true,
     doc_bold:          [:bright],
     doc_code:          [:cyan, :bright],
-     doc_headings:      [:yellow, :bright],
+     doc_headings:      [:yellow],
     doc_inline_code:   [:cyan],
     doc_table_heading: [:reverse],
-     doc_title:         [:reverse, :yellow, :bright],
+     doc_title:         [:reverse, :yellow],
     doc_underline:     [:underline],
     width:             80]
  end
@@ -59,56 +59,63 @@ defmodule IO.ANSI.Docs do
    doc
    |> String.split(["\r\n","\n"], trim: false)
    |> Enum.map(&String.rstrip/1)
-    |> process("", options)
+    |> process([], "", options)
  end

-  defp process([], _indent, _options), do: nil
+  defp process([], text, indent, options) do
+    write_text(text, indent, options)
+  end

-  defp process(["# " <> heading | rest], _indent, options) do
+  defp process(["# " <> heading | rest], text, indent, options) do
+    write_text(text, indent, options)
    write_h1(String.strip(heading), options)
-    process(rest, "", options)
+    process(rest, [], "", options)
  end

-  defp process(["## " <> heading | rest], _indent, options) do
+  defp process(["## " <> heading | rest], text, indent, options) do
+    write_text(text, indent, options)
    write_h2(String.strip(heading), options)
-    process(rest, "", options)
+    process(rest, [], "", options)
  end

-  defp process(["### " <> heading | rest], indent, options) do
+  defp process(["### " <> heading | rest], text, indent, options) do
+    write_text(text, indent, options)
    write_h3(String.strip(heading), indent, options)
-    process(rest, indent, options)
+    process(rest, [], "", options)
  end

-  defp process(["" | rest], indent, options) do
-    process(rest, indent, options)
+  defp process(["" | rest], text, indent, options) do
+    write_text(text, indent, options)
+    process(rest, [], indent, options)
  end

-  defp process(["    " <> line | rest], indent, options) do
+  defp process(["    " <> line | rest], text, indent, options) do
+    write_text(text, indent, options)
    process_code(rest, [line], indent, options)
  end

-  defp process(all=[line | rest], indent, options) do
-    {stripped, count} = strip_spaces(line, 0)
-    if is_table_line?(stripped) && length(rest) > 0 && is_table_line?(hd(rest)) do
+  defp process(all=[line | rest], text, indent, options) do
+    {stripped, count} = strip_spaces(line, 0, :infinity)
+    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 ->
-          process_list(item, rest, count, indent, options)
+        <<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_text(rest, [line], indent, false, options)
+          process(rest, [stripped | text], indent, options)
      end
    end
  end

-  defp strip_spaces(" " <> line, acc) do
-    strip_spaces(line, acc + 1)
-  end
-
-  defp strip_spaces(rest, acc) do
-    {rest, acc}
-  end
-
  ## Headings

  defp write_h1(heading, options) do
@@ -128,82 +135,70 @@ defmodule IO.ANSI.Docs do

  ## Lists

-  defp process_list(line, rest, count, indent, options) do
-    IO.write indent <> "• "
-    {contents, rest, done} = process_list_next(rest, count, false, [])
-    process_text(contents, [line], indent <> "  ", true, options)
-    if done, do: IO.puts(IO.ANSI.reset)
-    process(rest, indent, options)
+  defp process_list(entry, line, rest, count, indent, options) do
+    # The first list always win some extra padding
+    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), [])
+    process(contents, [indent <> entry <> line, :no_wrap], new_indent, options)
+
+    if done, do: newline_after_block()
+    process(rest, [], indent, options)
  end

-  # Process the thing after a list item entry. It can be either:
-  #
-  # * Continuation of the list
-  # * A nested list
-  # * The end of the list
-  #
-  defp process_list_next([" " <> _ = line | rest], count, _done, acc) do
-    case list_next(line, count) do
-      :done    -> {Enum.reverse(acc), [line|rest], false}
-      chopped  -> process_list_next(rest, count, false, [chopped|acc])
+  defp process_list_next([line | rest], count, max, acc) do
+    {stripped, next_count} = strip_spaces(line, 0, max)
+    case process_list_next_kind(stripped, rest, count, next_count) do
+      :next -> process_list_next(rest, count, max, [stripped | acc])
+      :done -> {Enum.reverse(acc), [line | rest], true}
+      :list -> {Enum.reverse(acc), [line | rest], false}
    end
  end

-  defp process_list_next([<<bullet, ?\s, _ :: binary>> | _] = rest, _count, _done, acc) when bullet in @bullets do
-    {Enum.reverse(acc), rest, false}
+  defp process_list_next([], _count, _max, acc) do
+    {Enum.reverse(acc), [], true}
  end

-  defp process_list_next(["" | rest], count, _done, acc) do
-    process_list_next(rest, count, true, [""|acc])
-  end
-
-  defp process_list_next(rest, _count, done, acc) do
-    {Enum.reverse(acc), rest, done}
-  end
-
-  defp list_next(<<bullet, ?\s, _ :: binary>>, 0) when bullet in @bullets, do: :done
-  defp list_next(line, 0),          do: chop(line, 2)
-  defp list_next(" " <> line, acc), do: list_next(line, acc - 1)
-  defp list_next(line, _acc),       do: line
-
-  defp chop(" " <> line, acc) when acc > 0, do: chop(line, acc - 1)
-  defp chop(line, _acc), do: line
-
-  ## Text (paragraphs / lists)
-
-  defp process_text(doc=["" | _], para, indent, from_list, options) do
-    write_text(Enum.reverse(para), indent, from_list, options)
-    process(doc, indent, options)
-  end
-
-  defp process_text([], para, indent, from_list, options) do
-    write_text(Enum.reverse(para), indent, from_list, options)
-  end
-
-  defp process_text([line | rest], para, indent, true, options) do
-    {stripped, count} = strip_spaces(line, 0)
-    case stripped do
-      <<bullet, ?\s, item :: binary>> when bullet in @bullets ->
-        write_text(Enum.reverse(para), indent, true, options)
-        process_list(item, rest, count, indent, options)
+  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 ->
+        :list
+      {<<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 ->
+        :list
+      {"", [" " <> _ | _]} ->
+        :next
+      {"", _} ->
+        :done
      _ ->
-        process_text(rest, [line | para], indent, true, options)
+        :next
    end
  end

-  defp process_text([line | rest], para, indent, from_list, options) do
-    process_text(rest, [line | para], indent, from_list, options)
+  ## Text
+
+  defp write_text(text, indent, options) do
+    case Enum.reverse(text) do
+      [:no_wrap|rest] -> write_text(rest, indent, options, true)
+      rest -> write_text(rest, indent, options, false)
+    end
  end

-  defp write_text(lines, indent, from_list, options) do
+  defp write_text([], _indent, _options, _no_wrap) do
+    :ok
+  end
+
+  defp write_text(lines, indent, options, no_wrap) do
    lines
    |> Enum.join(" ")
    |> handle_links
-    |> handle_inline(nil, [], [], options)
+    |> handle_inline(options)
    |> String.split(~r{\s})
-    |> write_with_wrap(options[:width] - byte_size(indent), indent, from_list)
+    |> write_with_wrap(options[:width] - byte_size(indent), indent, no_wrap)

-    unless from_list, do: newline_after_block
+    unless no_wrap, do: newline_after_block()
  end

  ## Code blocks
@@ -213,17 +208,17 @@ defmodule IO.ANSI.Docs do
  end

  # Blank line between code blocks
-  defp process_code([ "", "    " <> line | rest ], code, indent, options) do
+  defp process_code(["", "    " <> line | rest], code, indent, options) do
    process_code(rest, [line, "" | code], indent, options)
  end

-  defp process_code([ "    " <> line | rest ], code, indent, options) do
+  defp process_code(["    " <> line | rest], code, indent, options) do
    process_code(rest, [line|code], indent, options)
  end

  defp process_code(rest, code, indent, options) do
    write_code(code, indent, options)
-    process(rest, indent, options)
+    process(rest, [], indent, options)
  end

  defp write_code(code, indent, options) do
@@ -237,7 +232,7 @@ defmodule IO.ANSI.Docs do
    {table, rest} = Enum.split_while(lines, &is_table_line?/1)
    table_lines(table, options)
    newline_after_block
-    process(rest, indent, options)
+    process(rest, [], indent, options)
  end

  defp table_lines(lines, options) do
@@ -267,13 +262,8 @@ defmodule IO.ANSI.Docs do
    col = col
          |> String.replace(~r/\\ \|/x, "|")
          |> handle_links
-          |> handle_inline(nil, [], [], options)
-
-    len = col
-          |> String.replace(~r/\e\[\d+m/, "")
-          |> String.length
-
-    {col, len}
+          |> handle_inline(options)
+    {col, length_without_escape(col, 0)}
  end

  defp pad_to_number_of_columns(cols, col_count),
@@ -319,15 +309,20 @@ defmodule IO.ANSI.Docs do
    end
  end

-  ## Helpers
-
-  @table_line_re ~r'''
+  defp is_table_line?(line) do
+    Regex.match?(~r'''
      ( ^ \s{0,3} \| (?: [^|]+ \|)+ \s* $ )
    |
      (\s \| \s)
-  '''x
+    '''x, line)
+  end

-  defp is_table_line?(line), do: Regex.match?(@table_line_re, line)
+  ## Helpers
+
+  defp strip_spaces(" " <> line, acc, max) when acc < max,
+    do: strip_spaces(line, acc + 1, max)
+  defp strip_spaces(rest, acc, _max),
+    do: {rest, acc}

  defp write(style, string, options) do
    IO.puts [color(style, options), string, IO.ANSI.reset]
@@ -375,7 +370,7 @@ defmodule IO.ANSI.Docs do

  defp length_without_escape(rest, count) do
    case String.next_grapheme(rest) do
-      {_, rest}  -> length_without_escape(rest, count + 1)
+      {_, rest} -> length_without_escape(rest, count + 1)
      nil -> count
    end
  end
@@ -388,10 +383,8 @@ defmodule IO.ANSI.Docs do

  defp escape_underlines_in_link(text) do
    case Regex.match?(~r{.*(https?\S*)}, text) do
-      true ->
-        Regex.replace(~r{_}, text, "\\\\_")
-      _ ->
-        text
+      true -> Regex.replace(~r{_}, text, "\\\\_")
+      _    -> text
    end
  end

@@ -399,61 +392,104 @@ defmodule IO.ANSI.Docs do
    Regex.replace(~r{\[(.*?)\]\((.*?)\)}, text, "\\1 (\\2)")
  end

-  # Single inline quotes.
-  @single [?`, ?_, ?*]

-  # ` does not require space in between
-  @spaced [?_, ?*]
+  # 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 [?_, ?*]

-  # Clauses for handling spaces
-  defp handle_inline(<<?*, ?*, ?\s, rest :: binary>>, nil, buffer, acc, options) do
-    handle_inline(rest, nil, [?\s, ?*, ?*|buffer], acc, options)
+  # Characters that can mark the beginning or the end of a word.
+  # Only support the most common ones at this moment.
+  @delimiters [?\s, ?', ?", ?!, ?@, ?#, ?$, ?%, ?^, ?&, ?-, ?+, ?(, ?), ?[, ?], ?{, ?}, ?<, ?>, ?.]
+
+  # Inline start
+
+  defp handle_inline(<<?*, ?*, rest :: binary>>, options) do
+    handle_inline(rest, ?d, ["**"], [], options)
  end

-  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)
+  defp handle_inline(<<mark, rest :: binary>>, options) when mark in @single do
+    handle_inline(rest, mark, [<<mark>>], [], options)
  end

-  defp handle_inline(<<?\s, ?*, ?*, rest :: binary>>, limit, buffer, acc, options) do
-    handle_inline(rest, limit, [?*, ?*, ?\s|buffer], acc, options)
+  defp handle_inline(rest, options) do
+    handle_inline(rest, nil, [], [], options)
  end

-  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)
+  # 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)
  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)
+  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
+
  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)
-  end
-
-  # A escape is not valid inside `
+  # An 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
+      when not(mark == limit and mark == ?`) do
    handle_inline(rest, limit, [mark|buffer], acc, options)
  end

-  # 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(<<?*, ?*, rest :: binary>>, ?d, buffer, acc, options) do
+
+  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)
+  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)
+  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

-  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
+  # Catch all

  defp handle_inline(<<char, rest :: binary>>, mark, buffer, acc, options) do
    handle_inline(rest, mark, [char|buffer], acc, options)
@@ -479,11 +515,6 @@ defmodule IO.ANSI.Docs do

  defp color(style, colors) do
    color = colors[style]
-    if is_binary(color) do
-      IO.puts :stderr, "warning: ANSI colors as strings is deprecated, " <>
-                       "they now must be a list of atoms, got #{inspect color} for #{inspect style}"
-      color = String.split(color, ",") |> Enum.map(&String.to_atom/1)
-    end
    IO.ANSI.format_fragment(color, colors[:enabled])
  end

@@ -57,7 +57,7 @@ defmodule IO.Stream do
          true  -> &IO.each_binstream(&1, line_or_bytes)
          false -> &IO.each_stream(&1, line_or_bytes)
        end
-      Stream.unfold(device, next_fun).(acc, fun)
+      Stream.resource(fn -> device end, next_fun, &(&1)).(acc, fun)
    end

    def count(_stream) do
@@ -1386,7 +1386,14 @@ defmodule Kernel do
      iex> "abcd" =~ "ad"
      false

+      iex> "abcd" =~ ""
+      true
+
  """
+
+  @spec (String.t =~ (String.t | Regex.t)) :: boolean
+  def left =~ "" when is_binary(left), do: true
+
  def left =~ right when is_binary(left) and is_binary(right) do
    :binary.match(left, right) != :nomatch
  end
@@ -1423,6 +1430,18 @@ defmodule Kernel do
      iex> inspect("olá", binaries: :as_binaries)
      "<<111, 108, 195, 161>>"

+      iex> inspect('bar')
+      "'bar'"
+
+      iex> inspect([0|'bar'])
+      "[0, 98, 97, 114]"
+
+      iex> inspect(100, base: :octal)
+      "0o144"
+
+      iex> inspect(100, base: :hex)
+      "0x64"
+
  Note that the inspect protocol does not necessarily return a valid
  representation of an Elixir term. In such cases, the inspected result
  must start with `#`. For example, inspecting a function will return:
@@ -1631,7 +1650,7 @@ defmodule Kernel do

      iex> users = [%{name: "john", age: 27}, %{name: "meg", age: 23}]
      iex> all = fn :get_and_update, data, next ->
-      ...>   Enum.map(data, next) |> List.unzip() |> List.to_tuple()
+      ...>   Enum.map(data, next) |> :lists.unzip
      ...> end
      iex> get_and_update_in(users, [all, :age], &{&1, &1 + 1})
      {[27, 23], [%{name: "john", age: 28}, %{name: "meg", age: 24}]}
@@ -1801,7 +1820,9 @@ defmodule Kernel do
  end

  defp unnest({{:., _, [expr, key]}, _, []}, acc, kind)
-      when is_tuple(expr) and elem(expr, 0) != :__aliases__ and elem(expr, 0) != :__MODULE__ do
+      when is_tuple(expr) and
+           :erlang.element(1, expr) != :__aliases__ and
+           :erlang.element(1, expr) != :__MODULE__ do
    unnest(expr, [{:map, key}|acc], kind)
  end

@@ -1822,8 +1843,8 @@ defmodule Kernel do

  defp proper_start?({{:., _, [expr, _]}, _, _args})
    when is_atom(expr)
-    when elem(expr, 0) == :__aliases__
-    when elem(expr, 0) == :__MODULE__, do: true
+    when :erlang.element(1, expr) == :__aliases__
+    when :erlang.element(1, expr) == :__MODULE__, do: true

  defp proper_start?({atom, _, _args})
    when is_atom(atom), do: true
@@ -1869,20 +1890,20 @@ defmodule Kernel do

  ## Examples

-      iex> nil?(1)
+      iex> is_nil(1)
      false

-      iex> nil?(nil)
+      iex> is_nil(nil)
      true

  """
-  defmacro nil?(x) do
+  defmacro is_nil(x) do
    quote do: unquote(x) == nil
  end

  @doc """
-  A convenient macro that checks if the right side matches
-  the left side. The left side is allowed to be a match pattern.
+  A convenience macro that checks if the right side (an expression)
+  matches the left side (a pattern).

  ## Examples

@@ -2001,7 +2022,7 @@ defmodule Kernel do
  defp do_at([arg], name, function?, env) do
    case function? do
      true ->
-        raise ArgumentError, "cannot dynamically set attribute @#{name} inside function"
+        raise ArgumentError, "cannot set attribute @#{name} inside function/macro"
      false ->
        case name do
          :behavior ->
@@ -2022,7 +2043,14 @@ defmodule Kernel do
    case function? do
      true ->
        attr = Module.get_attribute(env.module, name, stack)
-        :erlang.element(1, :elixir_quote.escape(attr, false))
+        try do
+          :elixir_quote.escape(attr, false)
+        rescue
+          e in [ArgumentError] ->
+            raise ArgumentError, "cannot inject attribute @#{name} into function/macro because " <> Exception.message(e)
+        else
+          {val, _} -> val
+        end
      false ->
        escaped = case stack do
          [] -> []
@@ -2038,7 +2066,7 @@ defmodule Kernel do
  end

  defp warn_info([entry|_]) do
-    opts = elem(entry, tuple_size(entry) - 1)
+    opts = :erlang.element(tuple_size(entry), entry)
    Exception.format_file_line(Keyword.get(opts, :file), Keyword.get(opts, :line)) <> " "
  end

@@ -2360,7 +2388,7 @@ defmodule Kernel do
  it is not loaded. Check `Code.ensure_loaded/1` for more
  information.
  """
-  @spec function_exported?(atom | tuple, atom, integer) :: boolean
+  @spec function_exported?(atom | tuple, atom, arity) :: boolean
  def function_exported?(module, function, arity) do
    :erlang.function_exported(module, function, arity)
  end
@@ -2889,31 +2917,35 @@ defmodule Kernel do
  structure is public should use `@type`.
  """
  defmacro defstruct(fields) do
-    fields =
-      quote bind_quoted: [fields: fields] do
-        fields = :lists.map(fn
-          {key, _} = pair when is_atom(key) -> pair
-          key when is_atom(key) -> {key, nil}
-          other -> raise ArgumentError, "struct field names must be atoms, got: #{inspect other}"
-        end, fields)
+    quote bind_quoted: [fields: fields] do
+      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)

-        @struct :maps.put(:__struct__, __MODULE__, :maps.from_list(fields))
+      @struct :maps.put(:__struct__, __MODULE__, :maps.from_list(fields))

-        case Module.get_attribute(__MODULE__, :derive) do
-          [] ->
-            :ok
-          derive ->
-            Protocol.__derive__(derive, __MODULE__, __ENV__)
-        end
+      case Module.get_attribute(__MODULE__, :derive) do
+        [] -> :ok
+        derive -> Protocol.__derive__(derive, __MODULE__, __ENV__)
+      end

-        @spec __struct__() :: %__MODULE__{}
-        def __struct__() do
-          @struct
-        end
+      @spec __struct__() :: %__MODULE__{}
+      def __struct__() do
+        @struct
      end

-    quote do
-      unquote(fields)
      fields
    end
  end
@@ -56,7 +56,7 @@ defmodule Kernel.CLI do
  ## Helpers

  defp at_exit(res) do
-    hooks = :elixir_code_server.call(:flush_at_exit)
+    hooks = :elixir_config.get_and_put(:at_exit, [])
    res = Enum.reduce(hooks, res, &exec_fun/2)
    if hooks == [], do: res, else: at_exit(res)
  end
@@ -113,7 +113,8 @@ defmodule Kernel.CLI do
    IO.puts :stderr, Exception.format(kind, reason, prune_stacktrace(trace))
  end

-  @elixir_internals [:elixir_compiler, :elixir_module, :elixir_translator, :elixir_expand]
+  @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)
@@ -408,7 +409,7 @@ defmodule Kernel.CLI do
  end

  defp wrapper(fun) do
-    fun.()
+    _ = fun.()
    :ok
  end

@@ -18,20 +18,22 @@ defmodule Kernel.LexicalTracker do
  Returns all remotes linked to in this lexical scope.
  """
  def remotes(arg) do
-    # If the module is compiled from a function, its lexical
-    # scope may be long gone, so it has no associated PID.
-    if pid = to_pid(arg) do
-      ets = :gen_server.call(pid, :ets, @timeout)
-      :ets.match(ets, {:"$1", :_, :_}) |> List.flatten
-    else
-      []
-    end
+    ets = :gen_server.call(to_pid(arg), :ets, @timeout)
+    :ets.match(ets, {:"$1", :_, :_}) |> List.flatten
+  end
+
+  @doc """
+  Gets the destination the lexical scope is meant to
+  compile to.
+  """
+  def dest(arg) do
+    :gen_server.call(to_pid(arg), :dest, @timeout)
  end

  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)
-    [{_, val}] = :ets.lookup(table, :__lexical_tracker)
+    [{_, val}] = :ets.lookup(table, {:elixir, :lexical_tracker})
    val
  end

@@ -39,9 +41,8 @@ defmodule Kernel.LexicalTracker do

  # Starts the tracker and returns its pid.
  @doc false
-  def start_link do
-    {:ok, pid} = :gen_server.start_link(__MODULE__, [], [])
-    pid
+  def start_link(dest) do
+    :gen_server.start_link(__MODULE__, dest, [])
  end

  @doc false
@@ -96,65 +97,69 @@ defmodule Kernel.LexicalTracker do

  # Callbacks

-
-  def init([]) do
-    {:ok, :ets.new(:lexical, [:protected])}
+  def init(dest) do
+    {:ok, {:ets.new(:lexical, [:protected]), dest}}
  end

  @doc false
-  def handle_call(:ets, _from, d) do
-    {:reply, d, d}
+  def handle_call(:ets, _from, {d, dest}) do
+    {:reply, d, {d, dest}}
  end

-  def handle_call(request, _from, d) do
-    {:stop, {:bad_call, request}, d}
+  def handle_call(:dest, _from, {d, dest}) do
+    {:reply, dest, {d, dest}}
  end

-  def handle_cast({:remote_dispatch, module}, d) do
+  def handle_call(request, _from, {d, dest}) do
+    {:stop, {:bad_call, request}, {d, dest}}
+  end
+
+  def handle_cast({:remote_dispatch, module}, {d, dest}) do
    add_module(d, module)
-    {:noreply, d}
+    {:noreply, {d, dest}}
  end

-  def handle_cast({:import_dispatch, module}, d) do
+  def handle_cast({:import_dispatch, module}, {d, dest}) do
    add_dispatch(d, module, @import)
-    {:noreply, d}
+    {:noreply, {d, dest}}
  end

-  def handle_cast({:alias_dispatch, module}, d) do
+  def handle_cast({:alias_dispatch, module}, {d, dest}) do
    add_dispatch(d, module, @alias)
-    {:noreply, d}
+    {:noreply, {d, dest}}
  end

-  def handle_cast({:add_import, module, line, warn}, d) do
+  def handle_cast({:add_import, module, line, warn}, {d, dest}) do
    add_directive(d, module, line, warn, @import)
-    {:noreply, d}
+    {:noreply, {d, dest}}
  end

-  def handle_cast({:add_alias, module, line, warn}, d) do
+  def handle_cast({:add_alias, module, line, warn}, {d, dest}) do
    add_directive(d, module, line, warn, @alias)
-    {:noreply, d}
+    {:noreply, {d, dest}}
  end

-  def handle_cast(:stop, d) do
-    {:stop, :normal, d}
+  def handle_cast(:stop, {d, dest}) do
+    {:stop, :normal, {d, dest}}
  end

-  def handle_cast(msg, d) do
-    {:stop, {:bad_cast, msg}, d}
-  end
-
-  def handle_info(_msg, d) do
-    {:noreply, d}
+  def handle_cast(msg, {d, dest}) do
+    {:stop, {:bad_cast, msg}, {d, dest}}
  end

  @doc false
-  def terminate(_reason, _d) do
+  def handle_info(_msg, {d, dest}) do
+    {:noreply, {d, dest}}
+  end
+
+  @doc false
+  def terminate(_reason, _state) do
    :ok
  end

  @doc false
-  def code_change(_old, d, _extra) do
-    {:ok, d}
+  def code_change(_old, state, _extra) do
+    {:ok, state}
  end

  # Callbacks helpers
@@ -15,7 +15,7 @@ defmodule Kernel.ParallelCompiler do
  is set to `true` and there is a warning, this function will fail
  with an exception.

-  This function receives a set of callbacks as options:
+  This function accepts the following options:

    * `:each_file` - for each file compiled, invokes the callback passing the
      file
@@ -23,32 +23,36 @@ defmodule Kernel.ParallelCompiler do
    * `:each_module` - for each module compiled, invokes the callback passing
      the file, module and the module bytecode

-  The compiler doesn't care about the return values of the callbacks.
+    * `: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.
  """
-  def files(files, callbacks \\ [])
+  def files(files, options \\ [])

-  def files(files, callbacks) when is_list(callbacks) do
-    spawn_compilers(files, nil, callbacks)
+  def files(files, options) when is_list(options) do
+    spawn_compilers(files, nil, options)
  end

  @doc """
  Compiles the given files to the given path.
  Read `files/2` for more information.
  """
-  def files_to_path(files, path, callbacks \\ [])
+  def files_to_path(files, path, options \\ [])

-  def files_to_path(files, path, callbacks) when is_binary(path) and is_list(callbacks) do
-    spawn_compilers(files, path, callbacks)
+  def files_to_path(files, path, options) when is_binary(path) and is_list(options) do
+    spawn_compilers(files, path, options)
  end

-  defp spawn_compilers(files, path, callbacks) do
+  defp spawn_compilers(files, path, options) do
    true = Code.ensure_loaded?(Kernel.ErrorHandler)
    compiler_pid = self()
    :elixir_code_server.cast({:reset_warnings, compiler_pid})
    schedulers = max(:erlang.system_info(:schedulers_online), 2)

-    result = spawn_compilers(files, files, path, callbacks, [], [], schedulers, [])
+    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 and we fail with CompileError
@@ -59,21 +63,21 @@ defmodule Kernel.ParallelCompiler do
  end

  # We already have 4 currently running, don't spawn new ones
-  defp spawn_compilers(entries, original, output, callbacks, waiting, queued, schedulers, result) when
+  defp spawn_compilers(entries, original, output, options, waiting, queued, schedulers, result) when
      length(queued) - length(waiting) >= schedulers do
-    wait_for_messages(entries, original, output, callbacks, waiting, queued, schedulers, result)
+    wait_for_messages(entries, original, output, options, waiting, queued, schedulers, result)
  end

  # Release waiting processes
-  defp spawn_compilers([h|t], original, output, callbacks, waiting, queued, schedulers, result) when is_pid(h) do
+  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, callbacks, waiting, queued, schedulers, result)
+    spawn_compilers(t, original, output, options, waiting, queued, schedulers, result)
  end

  # Spawn a compiler for each file in the list until we reach the limit
-  defp spawn_compilers([h|t], original, output, callbacks, waiting, queued, schedulers, result) do
+  defp spawn_compilers([h|t], original, output, options, waiting, queued, schedulers, result) do
    parent = self()

    {pid, ref} =
@@ -90,40 +94,40 @@ defmodule Kernel.ParallelCompiler do
          _ = if output do
            :elixir_compiler.file_to_path(h, output)
          else
-            :elixir_compiler.file(h)
+            :elixir_compiler.file(h, Keyword.get(options, :dest))
          end
-          {:compiled, h}
+          {:shutdown, h}
        catch
          kind, reason ->
            {:failure, kind, reason, System.stacktrace}
        end)
      end

-    spawn_compilers(t, original, output, callbacks, waiting,
+    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([], _original, _output, _callbacks, [], [], _schedulers, 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([], original, output, callbacks, waiting, queued, schedulers, result) when length(waiting) == length(queued) do
+  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, callbacks, waiting, queued, schedulers, result)
+    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([], original, output, callbacks, waiting, queued, schedulers, result) do
-    wait_for_messages([], original, output, callbacks, waiting, queued, schedulers, result)
+  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(entries, original, output, callbacks, waiting, queued, schedulers, result) do
+  defp wait_for_messages(entries, original, output, options, waiting, queued, schedulers, result) do
    receive do
      {:struct_available, module} ->
        available = for {:struct, pid, _, waiting_module} <- waiting,
@@ -131,11 +135,11 @@ defmodule Kernel.ParallelCompiler do
                        not pid in entries,
                        do: pid

-        spawn_compilers(available ++ entries, original, output, callbacks,
+        spawn_compilers(available ++ entries, original, output, options,
                        waiting, queued, schedulers, [{:struct, module}|result])

      {:module_available, child, ref, file, module, binary} ->
-        if callback = Keyword.get(callbacks, :each_module) do
+        if callback = Keyword.get(options, :each_module) do
          callback.(file, module, binary)
        end

@@ -147,7 +151,7 @@ defmodule Kernel.ParallelCompiler do
                        not pid in entries,
                        do: pid

-        spawn_compilers(available ++ entries, original, output, callbacks,
+        spawn_compilers(available ++ entries, original, output, options,
                        waiting, queued, schedulers, [{:module, module}|result])

      {:waiting, kind, child, ref, on} ->
@@ -160,10 +164,10 @@ defmodule Kernel.ParallelCompiler do
          waiting = [{kind, child, ref, on}|waiting]
        end

-        spawn_compilers(entries, original, output, callbacks, waiting, queued, schedulers, result)
+        spawn_compilers(entries, original, output, options, waiting, queued, schedulers, result)

-      {:DOWN, _down_ref, :process, down_pid, {:compiled, file}} ->
-        if callback = Keyword.get(callbacks, :each_file) do
+      {:DOWN, _down_ref, :process, down_pid, {:shutdown, file}} ->
+        if callback = Keyword.get(options, :each_file) do
          callback.(file)
        end

@@ -172,20 +176,26 @@ defmodule Kernel.ParallelCompiler do
        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, callbacks, new_waiting, new_queued, schedulers, result)
+        spawn_compilers(new_entries, original, output, options, new_waiting, new_queued, schedulers, result)

      {:DOWN, down_ref, :process, _down_pid, reason} ->
        handle_failure(down_ref, reason, entries, waiting, queued)
-        wait_for_messages(entries, original, output, callbacks, waiting, queued, schedulers, result)
+        wait_for_messages(entries, original, output, options, waiting, queued, schedulers, result)
    end
  end

  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
+
+      Enum.each queued, fn {child, _, _} ->
+        Process.exit(child, :kill)
+      end
+
      exit({:shutdown, 1})
    end
  end
@@ -197,7 +207,7 @@ defmodule Kernel.ParallelCompiler do
    end
  end

-  defp print_failure(_file, {:compiled, _}) do
+  defp print_failure(_file, {:shutdown, _}) do
    :ok
  end

@@ -211,7 +221,8 @@ defmodule Kernel.ParallelCompiler do
    IO.puts Exception.format(:exit, reason, [])
  end

-  @elixir_internals [:elixir_compiler, :elixir_module, :elixir_translator, :elixir_expand]
+  @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)
@@ -172,10 +172,22 @@ defmodule Kernel.SpecialForms do
      iex> << 1, 2, 3 >>
      << 1, 2, 3 >>

-  ## Bitstring types
+  ## Types

-  A bitstring is made of many segments. Each segment has a
-  type, which defaults to integer:
+  A bitstring is made of many segments and each segment has a
+  type. There are 9 types used in bitstrings:
+
+    - `integer`
+    - `float`
+    - `bits` (alias for bitstring)
+    - `bitstring`
+    - `binary`
+    - `bytes` (alias for binary)
+    - `utf8`
+    - `utf16`
+    - `utf32`
+
+  When no type is specified, the default is `integer`:

      iex> <<1, 2, 3>>
      <<1, 2, 3>>
@@ -186,14 +198,7 @@ defmodule Kernel.SpecialForms do
      iex> <<0, "foo">>
      <<0, 102, 111, 111>>

-  Any other type needs to be explicitly tagged. For example,
-  in order to store a float type in the binary, one has to do:
-
-      iex> <<3.14 :: float>>
-      <<64, 9, 30, 184, 81, 235, 133, 31>>
-
-  This also means that variables need to be explicitly tagged,
-  otherwise Elixir defaults to integer:
+  Variables or any other type need to be explicitly tagged:

      iex> rest = "oo"
      iex> <<102, rest>>
@@ -201,103 +206,161 @@ defmodule Kernel.SpecialForms do

  We can solve this by explicitly tagging it as a binary:

-      <<102, rest :: binary>>
-
-  The type can be integer, float, bitstring/bits, binary/bytes,
-  utf8, utf16 or utf32, e.g.:
-
-      <<102 :: float, rest :: binary>>
-
-  An integer can be any arbitrary precision integer. A float is an
-  IEEE 754 binary32 or binary64 floating point number. A bitstring
-  is an arbitrary series of bits. A binary is a special case of
-  bitstring that has a total size divisible by 8.
+      iex> rest = "oo"
+      iex> <<102, rest :: binary>>
+      "foo"

  The utf8, utf16, and utf32 types are for unicode codepoints. They
  can also be applied to literal strings and char lists:

      iex> <<"foo" :: utf16>>
-      <<0,102,0,111,0,111>>
+      <<0, 102, 0, 111, 0, 111>>
+      iex> <<"foo" :: utf32>>
+      <<0, 0, 0, 102, 0, 0, 0, 111, 0, 0, 0, 111>>

-  The bits type is an alias for bitstring. The bytes type is an
-  alias for binary.
+  ## Options

-  The signedness can also be given as signed or unsigned. The
-  signedness only matters for matching and relevant only for
-  integers. If unspecified, it defaults to unsigned. Example:
-
-      iex> <<-100 :: signed, _rest :: binary>> = <<-100, "foo">>
-      <<156,102,111,111>>
-
-  This match would have failed if we did not specify that the
-  value -100 is signed. If we're matching into a variable instead
-  of a value, the signedness won't be checked; rather, the number
-  will simply be interpreted as having the given (or implied)
-  signedness, e.g.:
-
-      iex> <<val, _rest :: binary>> = <<-100, "foo">>
-      iex> val
-      156
-
-  Here, `val` is interpreted as unsigned.
-
-  The endianness of a segment can be big, little or native (the
-  latter meaning it will be resolved at VM load time). Many options
-  can be given by using `-` as separator:
+  Many options can be given by using `-` as separator. Order is
+  arbitrary, so the following are all equivalent:

      <<102 :: integer-native, rest :: binary>>
-
-  Or:
-
+      <<102 :: native-integer, rest :: binary>>
      <<102 :: unsigned-big-integer, rest :: binary>>
+      <<102 :: unsigned-big-integer-size(8), rest :: binary>>
+      <<102 :: unsigned-big-integer-8, rest :: binary>>
+      <<102 :: 8-integer-big-unsigned, rest :: binary>>
+      <<102, rest :: binary>>

-  And so on.
+  ### Unit and Size

-  Endianness only makes sense for integers and some UTF code
-  point types (utf16 and utf32).
+  The length of the match is equal to the `unit` (a number of bits) times the
+  `size` (the number of repeated segnments of length `unit`).

-  Finally, we can also specify size and unit for each segment. The
-  unit is multiplied by the size to give the effective size of
-  the segment in bits. The default unit for integers, floats,
-  and bitstrings is 1. For binaries, it is 8.
+  Type      | Default Unit
+  --------- | ------------
+  `integer` | 1 bit
+  `float`   | 1 bit
+  `binary`  | 8 bits

-  Since integers are default, the default unit is 1. The example below
-  matches because the string "foo" takes 24 bits and we match it
-  against a segment of 24 bits, 8 of which are taken by the integer
-  102 and the remaining 16 bits are specified on the rest.
+  Sizes for types are a bit more nuanced. The default size for integers is 8.

-      iex> <<102, _rest :: size(16)>> = "foo"
-      "foo"
+  For floats, it is 64. For floats, `size * unit` must result in 32 or 64,
+  corresponding to [IEEE 754](http://en.wikipedia.org/wiki/IEEE_floating_point)
+  binary32 and binary64, respectively.

-  We can also match by specifying size and unit explicitly:
+  For binaries, the default is the size of the binary. Only the last binary in a
+  match can use the default size. All others must have their size specified
+  explicitly, even if the match is unambiguous. For example:

-      iex> <<102, _rest :: size(2)-unit(8)>> = "foo"
-      "foo"
+      iex> <<name::binary-size(5), " the ", species::binary>> = <<"Frank the Walrus">>
+      "Frank the Walrus"
+      iex> {name, species}
+      {"Frank", "Walrus"}

-  However, if we expect a size of 32, it won't match:
+  Failing to specify the size for the non-last causes compilation to fail:

-      iex> <<102, _rest :: size(32)>> = "foo"
-      ** (MatchError) no match of right hand side value: "foo"
+      <<name::binary, " the ", species::binary>> = <<"Frank the Walrus">>
+      ** (CompileError): a binary field without size is only allowed at the end of a binary pattern

-  Size and unit are not applicable to utf8, utf16, and utf32.
-
-  The default size for integers is 8. For floats, it is 64. For
-  binaries, it is the size of the binary. Only the last binary
-  in a binary match can use the default size (all others must
-  have their size specified explicitly).
+  #### Shortcut Syntax

  Size and unit can also be specified using a syntax shortcut
  when passing integer values:

-      << x :: 8 >> == << x :: size(8) >>
-      << x :: 8 * 4 >> == << x :: size(8)-unit(4) >>
-      << x :: _ * 4 >> == << x :: unit(4) >>
+      iex> x = 1
+      iex> << x :: 8 >> == << x :: size(8) >>
+      true
+      iex> << x :: 8 * 4 >> == << x :: size(8)-unit(4) >>
+      true

  This syntax reflects the fact the effective size is given by
  multiplying the size by the unit.

-  For floats, `size * unit` must result in 32 or 64, corresponding
-  to binary32 and binary64, respectively.
+  ### Modifiers
+
+  Some types have associated modifiers to clear up ambiguity in byte
+  representation.
+
+  Modifier             | Relevant Type(s)
+  -------------------- | ----------------
+  `signed`             | `integer`
+  `unsigned` (default) | `integer`
+  `little`             | `integer`, `utf16`, `utf32`
+  `big` (default)      | `integer`, `utf16`, `utf32`
+  `native`             | `integer`, `utf16`, `utf32`
+
+  ### Sign
+
+  Integers can be `signed` or `unsigned`, defaulting to `unsigned`.
+
+      iex> <<int::integer>> =  <<-100>>
+      <<156>>
+      iex> int
+      156
+      iex> <<int::integer-signed>> =  <<-100>>
+      <<156>>
+      iex> int
+      -100
+
+  `signed` and `unsigned` are only used for matching binaries (see below) and
+  are only used for integers.
+
+      iex> <<-100 :: signed, _rest :: binary>> = <<-100, "foo">>
+      <<156, 102, 111, 111>>
+
+  ### Endianness
+
+  Elixir has three options for endianness: `big`, `little`, and `native`.
+  The default is `big`. `native` is determined by the VM at startup.
+
+      iex> <<number::little-integer-size(16)>> = <<0, 1>>
+      <<0, 1>>
+      iex> number
+      256
+      iex> <<number::big-integer-size(16)>> = <<0, 1>>
+      <<0, 1>>
+      iex> number
+      1
+      iex> <<number::native-integer-size(16)>> = <<0, 1>>
+      <<0, 1>>
+      iex> number
+      256
+
+  ## Binary/Bitstring Matching
+
+  Binary matching is a powerful feature in Elixir that is useful for extracting
+  information from binaries as well as pattern matching.
+
+  Binary matching can be used by itself to extract information from binaries:
+
+      iex> <<"Hello, ", place::binary>> = "Hello, World"
+      "Hello, World"
+      iex> place
+      "World"
+
+  Or as a part of function definitions to pattern match:
+
+      defmodule ImageTyper
+        @png_signature <<137::size(8), 80::size(8), 78::size(8), 71::size(8),
+                      13::size(8), 10::size(8), 26::size(8), 10::size(8)>>
+        @jpg_signature <<255::size(8), 216::size(8)>>
+
+        def type(<<@png_signature, rest::binary>>), do: :png
+        def type(<<@jpg_signature, rest::binary>>), do: :jpg
+        def type(_), do :unknown
+      end
+
+  ### Performance & Optimizations
+
+  The Erlang compiler can provide a number of optimizations on binary creation
+  and matching. To see optimization output, set the `bin_opt_info` compiler
+  option:
+
+      ERL_COMPILER_OPTIONS=bin_opt_info mix compile
+
+  To learn more about specific optimizations and performance considerations,
+  check out
+  [Erlang's Efficiency Guide on handling binaries](http://www.erlang.org/doc/efficiency_guide/binaryhandling.html).
  """
  defmacro unquote(:<<>>)(args)

@@ -343,28 +406,9 @@ defmodule Kernel.SpecialForms do

  Note that `Kernel."HELLO"` will be treated as a remote call and not an alias.
  This choice was done so every time single- or double-quotes are used, we have
-  a remote call irregardless of the quote contents. This decision is also reflected
+  a remote call regardless of the quote contents. This decision is also reflected
  in the quoted expressions discussed below.

-  ## Runtime (dynamic) behaviour
-
-  The result returned by `.` is always specified by the right-side:
-
-      iex> x = String
-      iex> x.downcase("FOO")
-      "foo"
-      iex> x.Sample
-      String.Sample
-
-  In case the right-side is also dynamic, `.`'s behaviour can be reproduced
-  at runtime via `apply/3` and `Module.concat/2`:
-
-      iex> apply(:erlang, :+, [1,2])
-      3
-
-      iex> Module.concat(Kernel, Sample)
-      Kernel.Sample
-
  ## Quoted expression

  When `.` is used, the quoted expression may take two distinct
@@ -1112,7 +1156,7 @@ defmodule Kernel.SpecialForms do

  ## Examples

-  Imagine the situation you have a variable `name` and
+  Imagine the situation you have a variable `value` and
  you want to inject it inside some quote. The first attempt
  would be:

@@ -1327,22 +1371,13 @@ defmodule Kernel.SpecialForms do

  On the other hand, aliases holds some properties:

-    1. The head element of aliases can be any term.
+    1. The head element of aliases can be any term that must expand to
+       an atom at compilation time.

    2. The tail elements of aliases are guaranteed to always be atoms.

    3. When the head element of aliases is the atom `:Elixir`, no expansion happen.

-    4. When the head element of aliases is not an atom, it is expanded at runtime:
-
-           quote do: some_var.Foo
-           {:__aliases__, [], [{:some_var, [], Elixir}, :Foo]}
-
-       Since `some_var` is not available at compilation time, the compiler
-       expands such expression to:
-
-           Module.concat [some_var, Foo]
-
  """
  defmacro __aliases__(args)

@@ -644,6 +644,10 @@ defmodule Kernel.Typespec do
    []
  end

+  defp typespec_to_ast({:user_type, line, name, args}) do
+    typespec_to_ast({:type, line, name, args})
+  end
+
  defp typespec_to_ast({:type, line, :tuple, :any}) do
    {:tuple, [line: line], []}
  end
@@ -677,8 +681,13 @@ defmodule Kernel.Typespec do
  end

  defp typespec_to_ast({:type, line, :map, fields}) do
-    fields = Enum.map fields, fn {:type, _, :map_field_assoc, k, v} ->
-      {typespec_to_ast(k), typespec_to_ast(v)}
+    fields = Enum.map fields, fn
+      # OTP 18
+      {:type, _, :map_field_assoc, [k, v]} ->
+        {typespec_to_ast(k), typespec_to_ast(v)}
+      # OTP 17
+      {:type, _, :map_field_assoc, k, v} ->
+        {typespec_to_ast(k), typespec_to_ast(v)}
    end

    {struct, fields} = Keyword.pop(fields, :__struct__)
@@ -821,9 +830,17 @@ defmodule Kernel.Typespec do

  ## Handle maps and structs
  defp typespec({:%{}, meta, fields}, vars, caller) do
-    fields = :lists.map(fn {k, v} ->
-      {:type, line(meta), :map_field_assoc, typespec(k, vars, caller), typespec(v, vars, caller)}
-    end, fields)
+    fields =
+      if :erlang.system_info(:otp_release) >= '18' do
+        :lists.map(fn {k, v} ->
+          {:type, line(meta), :map_field_assoc, [typespec(k, vars, caller), typespec(v, vars, caller)]}
+        end, fields)
+      else
+        :lists.map(fn {k, v} ->
+          {:type, line(meta), :map_field_assoc, typespec(k, vars, caller), typespec(v, vars, caller)}
+        end, fields)
+      end
+
    {:type, line(meta), :map, fields}
  end

@@ -884,7 +901,8 @@ defmodule Kernel.Typespec do

  # Handle ranges
  defp typespec({:.., meta, args}, vars, caller) do
-    typespec({:range, meta, args}, vars, caller)
+    args = for arg <- args, do: typespec(arg, vars, caller)
+    {:type, line(meta), :range, args}
  end

  # Handle special forms
@@ -968,9 +986,21 @@ defmodule Kernel.Typespec do
    typespec((quote do: :elixir.as_boolean(unquote(arg))), vars, caller)
  end

+  defp typespec({:fun, meta, args}, vars, caller) do
+    args = for arg <- args, do: typespec(arg, vars, caller)
+    {:type, line(meta), :fun, args}
+  end
+
  defp typespec({name, meta, arguments}, vars, caller) do
    arguments = for arg <- arguments, do: typespec(arg, vars, caller)
-    {:type, line(meta), name, arguments}
+
+    if :erlang.system_info(:otp_release) >= '18' do
+      arity = length(arguments)
+      type = if :erl_internal.is_type(name, arity), do: :type, else: :user_type
+      {type, line(meta), name, arguments}
+    else
+      {:type, line(meta), name, arguments}
+    end
  end

  # Handle literals
@@ -998,7 +1028,7 @@ defmodule Kernel.Typespec do
    typespec({:list, [], [spec]}, vars, caller)
  end

-  defp typespec(list, vars, caller) do
+  defp typespec(list, vars, caller) when is_list(list) do
    [h|t] = :lists.reverse(list)
    union = :lists.foldl(fn(x, acc) ->
      {:|, [], [validate_kw(x, list, caller), acc]}
@@ -1006,6 +1036,10 @@ defmodule Kernel.Typespec do
    typespec({:list, [], [union]}, vars, caller)
  end

+  defp typespec(other, _vars, caller) do
+    compile_error(caller, "unexpected expression in typespec: #{Macro.to_string other}")
+  end
+
  ## Helpers

  defp compile_error(caller, desc) do
@@ -136,7 +136,7 @@ defmodule Keyword do
      :error

  """
-  @spec fetch(t, key) :: {:ok, value}
+  @spec fetch(t, key) :: {:ok, value} | :error
  def fetch(keywords, key) when is_list(keywords) and is_atom(key) do
    case :lists.keyfind(key, 1, keywords) do
      {^key, value} -> {:ok, value}
@@ -247,7 +247,7 @@ defmodule List do
      [a: 1, b: 2, c: 3]

  """
-  @spec keystore([tuple], any, non_neg_integer, tuple) :: [tuple]
+  @spec keystore([tuple], any, non_neg_integer, tuple) :: [tuple, ...]
  def keystore(list, key, position, new_tuple) do
    :lists.keystore(key, position + 1, list, new_tuple)
  end
@@ -324,26 +324,6 @@ defmodule List do
    do_zip(list_of_lists, [])
  end

-  @doc """
-  Unzips the given list of tuples into a list of lists.
-
-  The number of unzipped elements is equal to the size
-  of the smallest tuple in the list.
-
-  ## Examples
-
-      iex> List.unzip([{1, 2}, {3, 4}])
-      [[1, 3], [2, 4]]
-
-      iex> List.unzip([{1, :a, "apple"}, {2, :b, "banana"}, {3, :c}])
-      [[1, 2, 3], [:a, :b, :c]]
-
-  """
-  @spec unzip([tuple]) :: [list]
-  def unzip(list) when is_list(list) do
-    :lists.map &Tuple.to_list/1, zip(list)
-  end
-
  @doc """
  Returns a list with `value` inserted at the specified `index`.
  Note that `index` is capped at the list length. Negative indices
@@ -532,7 +512,7 @@ defmodule List do
      1023

  """
-  @spec to_integer(char_list, non_neg_integer) :: integer
+  @spec to_integer(char_list, 2..36) :: integer
  def to_integer(char_list, base) do
    :erlang.list_to_integer(char_list, base)
  end
@@ -17,6 +17,7 @@ defmodule Macro do
    :<, :>, :->,
    :+, :-, :*, :/, :=, :|, :.,
    :and, :or, :when, :in,
+    :~>>, :<<~, :~>, :<~, :<~>, :<|>,
    :<<<, :>>>, :|||, :&&&, :^^^, :~~~]

  @doc false
@@ -39,7 +40,8 @@ defmodule Macro do
      o when o in [:&&, :&&&, :and]           -> {:left, 140}
      o when o in [:==, :!=, :=~, :===, :!==] -> {:left, 150}
      o when o in [:<, :<=, :>=, :>]          -> {:left, 160}
-      o when o in [:|>, :<<<, :>>>]           -> {:left, 170}
+      o when o in [:|>, :<<<, :>>>, :<~, :~>,
+                   :<<~, :~>>, :<~>, :<|>]    -> {:left, 170}
      :in                                     -> {:left, 180}
      o when o in [:++, :--, :.., :<>]        -> {:right, 200}
      o when o in [:+, :-]                    -> {:left, 210}
@@ -305,6 +307,40 @@ defmodule Macro do
    elem(:elixir_quote.escape(expr, Keyword.get(opts, :unquote, false)), 0)
  end

+  @doc """
+  Validates the given expressions are valid quoted expressions.
+
+  Check the `type:Macro.t` for the specification of a valid
+  quoted expression.
+  """
+  @spec validate(term) :: :ok | {:error, term}
+  def validate(expr) do
+    find_invalid(expr) || :ok
+  end
+
+  defp find_invalid({left, right}), do:
+    find_invalid(left) || find_invalid(right)
+
+  defp find_invalid({left, meta, right}) when is_list(meta) and (is_atom(right) or is_list(right)), do:
+    find_invalid(left) || find_invalid(right)
+
+  defp find_invalid(list) when is_list(list), do:
+    Enum.find_value(list, &find_invalid/1)
+
+  defp find_invalid(pid)  when is_pid(pid),    do: nil
+  defp find_invalid(atom) when is_atom(atom),  do: nil
+  defp find_invalid(num)  when is_number(num), do: nil
+  defp find_invalid(bin)  when is_binary(bin), do: nil
+
+  defp find_invalid(fun) when is_function(fun) do
+    unless :erlang.fun_info(fun, :env) == {:env, []} and
+           :erlang.fun_info(fun, :type) == {:type, :external} do
+      {:error, fun}
+    end
+  end
+
+  defp find_invalid(other), do: {:error, other}
+
  @doc ~S"""
  Unescape the given chars.

@@ -797,7 +833,7 @@ defmodule Macro do
        :elixir_lexical.record_remote(receiver, env.lexical_tracker)
        {receiver, true}
      aliases ->
-        aliases = for alias <- aliases, do: elem(do_expand_once(alias, env), 0)
+        aliases = :lists.map(&elem(do_expand_once(&1, env), 0), aliases)

        case :lists.all(&is_atom/1, aliases) do
          true ->
@@ -903,7 +939,7 @@ defmodule Macro do
  be expanded.

  This function uses `expand_once/2` under the hood. Check
-  `expand_once/2` for more information and exmaples.
+  `expand_once/2` for more information and examples.
  """
  def expand(tree, env) do
    expand_until({tree, true}, env)
@@ -4,7 +4,22 @@ defmodule Macro.Env do

  The current environment can be accessed at any time as
  `__ENV__`. Inside macros, the caller environment can be
-  accessed as `__CALLER__`. It contains the following fields:
+  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
+  following trick:
+
+      def make_custom_env do
+        import SomeModule, only: [some_function: 2]
+        alias A.B.C
+        __ENV__
+      end
+
+  You may then call `make_custom_env()` to get a struct with the desired
+  imports and aliases included.
+
+  It contains the following fields:

    * `module` - the current module name
    * `file` - the current file name as a binary
@@ -105,9 +120,9 @@ defmodule Macro.Env do
  """
  def stacktrace(%{__struct__: Macro.Env} = env) do
    cond do
-      nil?(env.module) ->
+      is_nil(env.module) ->
        [{:elixir_compiler, :__FILE__, 1, relative_location(env)}]
-      nil?(env.function) ->
+      is_nil(env.function) ->
        [{env.module, :__MODULE__, 0, relative_location(env)}]
      true ->
        {name, arity} = env.function
@@ -85,6 +85,9 @@ defmodule Module do
      See http://www.erlang.org/doc/man/compile.html for the list of supported
      options.

+      Several uses of `@compile` will accumulate instead of overriding
+      previous ones.
+
      ### Example

            defmodule M do
@@ -476,19 +479,6 @@ defmodule Module do
    :elixir_aliases.safe_concat([left, right])
  end

-  @doc """
-  Gets an anonymous function from the given module, function
-  and arity. The module and function are not verified to exist.
-
-      iex> fun = Module.function(Kernel, :is_atom, 1)
-      iex> fun.(:hello)
-      true
-
-  """
-  def function(mod, fun, arity) do
-    :erlang.make_fun(mod, fun, arity)
-  end
-
  @doc """
  Attaches documentation to a given function or type. It expects
  the module the function/type belongs to, the line (a non negative
@@ -514,23 +504,23 @@ defmodule Module do
  def add_doc(module, line, kind, tuple, signature, doc) when
      kind in [:def, :defmacro, :type, :opaque] and (is_binary(doc) or is_boolean(doc) or doc == nil) do
    assert_not_compiled!(:add_doc, module)
-    table = docs_table_for(module)
+    table = data_table_for(module)

    {signature, _} = :lists.mapfoldl fn(x, acc) ->
      {simplify_signature(x, acc), acc + 1}
    end, 1, signature

-    case :ets.lookup(table, tuple) do
+    case :ets.lookup(table, {:doc, tuple}) do
      [] ->
-        :ets.insert(table, {tuple, line, kind, signature, doc})
+        :ets.insert(table, {{:doc, tuple}, line, kind, signature, doc})
        :ok
-      [{tuple, line, _old_kind, old_sign, old_doc}] ->
+      [{doc_tuple, line, _old_kind, old_sign, old_doc}] ->
        :ets.insert(table, {
-          tuple,
+          doc_tuple,
          line,
          kind,
          merge_signatures(old_sign, signature, 1),
-          if(nil?(doc), do: old_doc, else: doc)
+          if(is_nil(doc), do: old_doc, else: doc)
       })
        :ok
    end
@@ -622,7 +612,7 @@ defmodule Module do
  """
  def defines?(module, tuple) when is_tuple(tuple) do
    assert_not_compiled!(:defines?, module)
-    table = function_table_for(module)
+    table = defs_table_for(module)
    :ets.lookup(table, tuple) != []
  end

@@ -642,7 +632,7 @@ defmodule Module do
  """
  def defines?(module, tuple, kind) do
    assert_not_compiled!(:defines?, module)
-    table = function_table_for(module)
+    table = defs_table_for(module)
    case :ets.lookup(table, tuple) do
      [{_, ^kind, _, _, _, _, _}] -> true
      _ -> false
@@ -662,8 +652,8 @@ defmodule Module do
  """
  def definitions_in(module) do
    assert_not_compiled!(:definitions_in, module)
-    table = function_table_for(module)
-    for {tuple, _, _, _, _, _, _} <- :ets.tab2list(table), do: tuple
+    table = defs_table_for(module)
+    :lists.concat :ets.match(table, {:'$1', :_, :_, :_, :_, :_, :_})
  end

  @doc """
@@ -681,8 +671,8 @@ defmodule Module do
  """
  def definitions_in(module, kind) do
    assert_not_compiled!(:definitions_in, module)
-    table = function_table_for(module)
-    for {tuple, stored_kind, _, _, _, _, _} <- :ets.tab2list(table), stored_kind == kind, do: tuple
+    table = defs_table_for(module)
+    :lists.concat :ets.match(table, {:'$1', kind, :_, :_, :_, :_, :_})
  end

  @doc """
@@ -694,7 +684,7 @@ defmodule Module do
  def make_overridable(module, tuples) do
    assert_not_compiled!(:make_overridable, module)

-    for tuple <- tuples do
+    :lists.foreach(fn tuple ->
      case :elixir_def.lookup_definition(module, tuple) do
        false ->
          {name, arity} = tuple
@@ -702,27 +692,26 @@ defmodule Module do
        clause ->
          :elixir_def.delete_definition(module, tuple)

-          neighbours = if loaded?(Module.LocalsTracker) do
-            Module.LocalsTracker.yank(module, tuple)
-          else
+          neighbours = if :elixir_compiler.get_opt(:internal) do
            []
+          else
+            Module.LocalsTracker.yank(module, tuple)
          end

-          old    = get_attribute(module, :__overridable)
+          old    = :elixir_def_overridable.overridable(module)
          merged = :orddict.update(tuple, fn({count, _, _, _}) ->
            {count + 1, clause, neighbours, false}
          end, {1, clause, neighbours, false}, old)
-
-          put_attribute(module, :__overridable, merged)
+          :elixir_def_overridable.overridable(module, merged)
      end
-    end
+    end, tuples)
  end

  @doc """
  Returns `true` if `tuple` in `module` is marked as overridable.
  """
  def overridable?(module, tuple) do
-    !!List.keyfind(get_attribute(module, :__overridable), tuple, 0)
+    !!List.keyfind(:elixir_def_overridable.overridable(module), tuple, 0)
  end

  @doc """
@@ -741,7 +730,7 @@ defmodule Module do
    assert_not_compiled!(:put_attribute, module)
    table = data_table_for(module)
    value = normalize_attribute(key, value)
-    acc   = :ets.lookup_element(table, :__acc_attributes, 2)
+    acc   = :ets.lookup_element(table, {:elixir, :acc_attributes}, 2)

    new =
      if :lists.member(key, acc) do
@@ -842,13 +831,13 @@ defmodule Module do
    table = data_table_for(module)

    if Keyword.get(opts, :persist) do
-      old = :ets.lookup_element(table, :__persisted_attributes, 2)
-      :ets.insert(table, {:__persisted_attributes,  [new|old]})
+      old = :ets.lookup_element(table, {:elixir, :persisted_attributes}, 2)
+      :ets.insert(table, {{:elixir, :persisted_attributes}, [new|old]})
    end

    if Keyword.get(opts, :accumulate) do
-      old = :ets.lookup_element(table, :__acc_attributes, 2)
-      :ets.insert(table, {:__acc_attributes,  [new|old]})
+      old = :ets.lookup_element(table, {:elixir, :acc_attributes}, 2)
+      :ets.insert(table, {{:elixir, :acc_attributes}, [new|old]})
    end
  end

@@ -904,14 +893,14 @@ defmodule Module do
  end

  @doc false
-  def get_attribute(module, key, warn) when is_atom(key) and (is_list(warn) or nil?(warn)) do
+  def get_attribute(module, key, warn) when is_atom(key) and (is_list(warn) or is_nil(warn)) do
    assert_not_compiled!(:get_attribute, module)
    table = data_table_for(module)

    case :ets.lookup(table, key) do
      [{^key, val}] -> val
      [] ->
-        acc = :ets.lookup_element(table, :__acc_attributes, 2)
+        acc = :ets.lookup_element(table, {:elixir, :acc_attributes}, 2)

        cond do
          :lists.member(key, acc) ->
@@ -966,15 +955,11 @@ defmodule Module do
  end

  defp data_table_for(module) do
-    module
+    :elixir_module.data_table(module)
  end

-  defp function_table_for(module) do
-    :elixir_def.table(module)
-  end
-
-  defp docs_table_for(module) do
-    :elixir_module.docs_table(module)
+  defp defs_table_for(module) do
+    :elixir_module.defs_table(module)
  end

  defp assert_not_compiled!(fun, module) do
@@ -982,6 +967,4 @@ defmodule Module do
      raise ArgumentError,
        "could not call #{fun} on module #{inspect module} because it was already compiled"
  end
-
-  defp loaded?(module), do: is_tuple :code.is_loaded(module)
 end
@@ -83,7 +83,7 @@ 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)
-    [{_, val}] = :ets.lookup(table, :__locals_tracker)
+    [{_, val}] = :ets.lookup(table, {:elixir, :locals_tracker})
    val
  end

@@ -92,8 +92,7 @@ defmodule Module.LocalsTracker do
  # Starts the tracker and returns its pid.
  @doc false
  def start_link do
-    {:ok, pid} = :gen_server.start_link(__MODULE__, [], [])
-    pid
+    :gen_server.start_link(__MODULE__, [], [])
  end

  # Adds a definition into the tracker. A public
@@ -272,6 +271,7 @@ defmodule Module.LocalsTracker do
    {:stop, {:bad_call, request}, state}
  end

+  @doc false
  def handle_info(_msg, state) do
    {:noreply, state}
  end
@@ -360,7 +360,7 @@ defmodule Module.LocalsTracker do
  end

  defp replace_edge!(d, from, to) do
-    unless :lists.member(to, :digraph.out_neighbours(d, from)) do
+    _ = unless :lists.member(to, :digraph.out_neighbours(d, from)) do
      [:"$e"|_] = :digraph.add_edge(d, from, to)
    end
    :ok
@@ -30,7 +30,7 @@ defmodule Node do
  returns `{:error, :not_allowed}`. Returns `{:error, :not_found}` if the
  local node is not alive.
  """
-  @spec stop() :: :ok | {:error, term}
+  @spec stop() :: :ok | {:error, :not_allowed | :not_found}
  def stop() do
    :net_kernel.stop()
  end
@@ -60,40 +60,70 @@ defmodule Path do
  def absname(path, relative_to) do
    path = IO.chardata_to_string(path)
    case type(path) do
-      :relative -> join(relative_to, path)
-      :absolute ->
-        cond do
-          path == "/" ->
-            path
-          :binary.last(path) == ?/ ->
-            binary_part(path, 0, byte_size(path) - 1)
-          true ->
-            path
-        end
+      :relative -> absname_join(relative_to, path)
+      :absolute -> absname_join([path])
      :volumerelative ->
        relative_to = IO.chardata_to_string(relative_to)
        absname_vr(split(path), split(relative_to), relative_to)
    end
  end

-  ## Absolute path on current drive
+  # Absolute path on current drive
  defp absname_vr(["/"|rest], [volume|_], _relative),
-    do: join([volume|rest])
+    do: absname_join([volume|rest])

-  ## Relative to current directory on current drive.
+  # Relative to current directory on current drive.
  defp absname_vr([<<x, ?:>>|rest], [<<x, _ :: binary>>|_], relative),
-    do: absname(join(rest), relative)
+    do: absname(absname_join(rest), relative)

-  ## Relative to current directory on another drive.
+  # Relative to current directory on another drive.
  defp absname_vr([<<x, ?:>>|name], _, _relative) do
    cwd =
      case :file.get_cwd([x, ?:]) do
        {:ok, dir}  -> IO.chardata_to_string(dir)
        {:error, _} -> <<x, ?:, ?/>>
      end
-    absname(join(name), cwd)
+    absname(absname_join(name), cwd)
  end

+  # Joins a list
+  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())
+
+  # Joins two paths
+  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(<<>>, <<>>, result, os_type), do:
+    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)
+
+  defp reverse_maybe_remove_dirsep([?/, ?:, letter], :win32), do:
+    [letter, ?:, ?/]
+  defp reverse_maybe_remove_dirsep([?/], _), do:
+    [?/]
+  defp reverse_maybe_remove_dirsep([?/|name], _), do:
+    :lists.reverse(name)
+  defp reverse_maybe_remove_dirsep(name, _), do:
+    :lists.reverse(name)
+
  @doc """
  Converts the path to an absolute one and expands
  any `.` and `..` characters and a leading `~`.
@@ -106,7 +136,7 @@ defmodule Path do
  """
  @spec expand(t) :: binary
  def expand(path) do
-    normalize absname(expand_home(path), System.cwd!)
+    expand_dot absname(expand_home(path), System.cwd!)
  end

  @doc """
@@ -133,7 +163,7 @@ defmodule Path do
  """
  @spec expand(t, t) :: binary
  def expand(path, relative_to) do
-    normalize absname(absname(expand_home(path), expand_home(relative_to)), System.cwd!)
+    expand_dot absname(absname(expand_home(path), expand_home(relative_to)), System.cwd!)
  end

  @doc """
@@ -157,10 +187,7 @@ defmodule Path do
  """
  @spec type(t) :: :absolute | :relative | :volumerelative
  def type(name) when is_list(name) or is_binary(name) do
-    case :os.type() do
-      {:win32, _} -> win32_pathtype(name)
-      _           -> unix_pathtype(name)
-    end |> elem(0)
+    pathtype(name, major_os_type) |> elem(0)
  end

  @doc """
@@ -182,10 +209,20 @@ defmodule Path do
  """
  @spec relative(t) :: binary
  def relative(name) do
-    case :os.type() do
-      {:win32, _} -> win32_pathtype(name)
-      _           -> unix_pathtype(name)
-    end |> elem(1) |> IO.chardata_to_string
+    relative(name, major_os_type())
+  end
+
+  defp relative(name, os_type) do
+    pathtype(name, os_type)
+    |> elem(1)
+    |> IO.chardata_to_string
+  end
+
+  defp pathtype(name, os_type) do
+    case os_type do
+      :win32 -> win32_pathtype(name)
+      _      -> unix_pathtype(name)
+    end
  end

  defp unix_pathtype(<<?/, relative :: binary>>), do:
@@ -390,7 +427,7 @@ defmodule Path do
  end

  @doc """
-  Returns a string with one or more path components joined by the path separator.
+  Joins a list of strings.

  This function should be used to convert a list of strings to a path.
  Note that any trailing slash is removed on join.
@@ -411,11 +448,14 @@ defmodule Path do
  def join([name1, name2|rest]), do:
    join([join(name1, name2)|rest])
  def join([name]), do:
-    do_join(IO.chardata_to_string(name), <<>>, [], major_os_type())
+    name

  @doc """
  Joins two paths.

+  The right path will always be expanded to its relative format
+  and any trailing slash is removed on join.
+
  ## Examples

      iex> Path.join("foo", "bar")
@@ -423,40 +463,25 @@ defmodule Path do

  """
  @spec join(t, t) :: binary
-  def join(left, right),
-    do: do_join(IO.chardata_to_string(left), relative(right), [], major_os_type())
-
-  defp major_os_type do
-    :os.type |> elem(0)
+  def join(left, right) do
+    left    = IO.chardata_to_string(left)
+    os_type = major_os_type()
+    do_join(left, right, os_type) |> remove_dirsep(os_type)
  end

-  defp do_join(<<uc_letter, ?:, rest :: binary>>, relativename, [], :win32) when uc_letter in ?A..?Z, do:
-    do_join(rest, relativename, [?:, uc_letter+?a-?A], :win32)
-  defp do_join(<<?\\, rest :: binary>>, relativename, result, :win32), do:
-    do_join(<<?/, rest :: binary>>, relativename, result, :win32)
-  defp do_join(<<?/, rest :: binary>>, relativename, [?., ?/|result], os_type), do:
-    do_join(rest, relativename, [?/|result], os_type)
-  defp do_join(<<?/, rest :: binary>>, relativename, [?/|result], os_type), do:
-    do_join(rest, relativename, [?/|result], os_type)
-  defp do_join(<<>>, <<>>, result, os_type), do:
-    IO.iodata_to_binary(maybe_remove_dirsep(result, os_type))
-  defp do_join(<<>>, relativename, [?:|rest], :win32), do:
-    do_join(relativename, <<>>, [?:|rest], :win32)
-  defp do_join(<<>>, relativename, [?/|result], os_type), do:
-    do_join(relativename, <<>>, [?/|result], os_type)
-  defp do_join(<<>>, relativename, result, os_type), do:
-    do_join(relativename, <<>>, [?/|result], os_type)
-  defp do_join(<<char, rest :: binary>>, relativename, result, os_type), do:
-    do_join(rest, relativename, [char|result], os_type)
+  defp do_join("", right, os_type),   do: 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 maybe_remove_dirsep([?/, ?:, letter], :win32), do:
-    [letter, ?:, ?/]
-  defp maybe_remove_dirsep([?/], _), do:
-    [?/]
-  defp maybe_remove_dirsep([?/|name], _), do:
-    :lists.reverse(name)
-  defp maybe_remove_dirsep(name, _), do:
-    :lists.reverse(name)
+  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)
+    else
+      bin
+    end
+  end

  @doc ~S"""
  Splits the path into a list at the path separator.
@@ -568,7 +593,7 @@ defmodule Path do
    |> Enum.map(&IO.chardata_to_string/1)
  end

-  # Normalize the given path by expanding "..", "." and "~".
+  # expand_dot the given path by expanding "..", "." and "~".

  defp chardata_to_list(chardata) do
    case :unicode.characters_to_list(chardata) do
@@ -602,29 +627,34 @@ defmodule Path do
    end
  end

-  defp normalize(path), do: normalize(split(path), [])
+  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: expand_dot(:binary.split(path, "/", [:global]), [])

-  defp normalize([".."|t], ["/"|_] = acc) do
-    normalize t, acc
+  defp expand_dot([".."|t], [_, _|acc]) do
+    expand_dot t, acc
  end

-  defp normalize([".."|t], [<<letter, ?:, ?/>>|_] = acc) when letter in ?a..?z do
-    normalize t, acc
+  defp expand_dot(["."|t], acc) do
+    expand_dot t, acc
  end

-  defp normalize([".."|t], [_|acc]) do
-    normalize t, acc
+  defp expand_dot([h|t], acc) do
+    expand_dot t, ["/", h|acc]
  end

-  defp normalize(["."|t], acc) do
-    normalize t, acc
+  defp expand_dot([], ["/"|acc]) do
+    IO.iodata_to_binary(:lists.reverse(acc))
  end

-  defp normalize([h|t], acc) do
-    normalize t, [h|acc]
-  end
-
-  defp normalize([], acc) do
-    join :lists.reverse(acc)
+  defp major_os_type do
+    :os.type |> elem(0)
  end
 end
@@ -345,7 +345,7 @@ defmodule Process do

  See http://www.erlang.org/doc/man/erlang.html#process_flag-3 for more info.
  """
-  @spec flag(pid, process_flag, term) :: term
+  @spec flag(pid, :save_calls, non_neg_integer) :: non_neg_integer
  def flag(pid, flag, value) do
    :erlang.process_flag(pid, flag, value)
  end
@@ -19,11 +19,12 @@ defmodule Protocol do
  defmacro def({name, _, args}) when is_atom(name) and is_list(args) do
    arity = length(args)

-    type_args = for _ <- :lists.seq(2, arity), do: quote(do: term)
+    type_args = :lists.map(fn _ -> quote(do: term) end,
+                           :lists.seq(2, arity))
    type_args = [quote(do: t) | type_args]

-    call_args = for i <- :lists.seq(2, arity),
-                  do: {String.to_atom(<<?x, i + 64>>), [], __MODULE__}
+    call_args = :lists.map(fn i -> {String.to_atom(<<?x, i + 64>>), [], __MODULE__} end,
+                           :lists.seq(2, arity))
    call_args = [quote(do: t) | call_args]

    quote do
@@ -289,7 +290,7 @@ defmodule Protocol do

  defp beam_file(module) when is_atom(module) do
    case :code.which(module) do
-      :non_existing -> module
+      atom when is_atom(atom) -> module
      file -> file
    end
  end
@@ -440,7 +441,7 @@ defmodule Protocol do
      end

      # Define the implementation for builtins.
-      for {guard, mod} <- builtin do
+      :lists.foreach(fn {guard, mod} ->
        target = Module.concat(__MODULE__, mod)

        Kernel.def impl_for(data) when :erlang.unquote(guard)(data) do
@@ -449,7 +450,7 @@ defmodule Protocol do
            false -> any_impl_for
          end
        end
-      end
+      end, builtin)

      @spec impl_for!(term) :: atom() | no_return()
      Kernel.def impl_for!(data) do
@@ -609,16 +610,17 @@ defmodule Protocol do
  @doc false
  def __spec__?(module, name, arity) do
    signature = {name, arity}
-    specs     = Module.get_attribute(module, :spec)

+    specs = Module.get_attribute(module, :spec)
    found =
-      for {:spec, expr, caller} <- specs,
-        Kernel.Typespec.spec_to_signature(expr) == signature do
-        Kernel.Typespec.define_spec(:callback, expr, caller)
-        true
-      end
+      :lists.map(fn {:spec, expr, caller} ->
+        if Kernel.Typespec.spec_to_signature(expr) == signature do
+          Kernel.Typespec.define_spec(:callback, expr, caller)
+          true
+        end
+      end, specs)

-    found != []
+    :lists.any(& &1 == true, found)
  end

  ## Helpers
@@ -4,7 +4,7 @@ defmodule Record do

  Records are simply tuples where the first element is an atom:

-      iex> Record.record? {User, "john", 27}
+      iex> Record.is_record {User, "john", 27}
      true

  This module provides conveniences for working with records at
@@ -64,11 +64,11 @@ defmodule Record do
  ## Examples

      iex> record = {User, "john", 27}
-      iex> Record.record?(record, User)
+      iex> Record.is_record(record, User)
      true

  """
-  defmacro record?(data, kind) do
+  defmacro is_record(data, kind) do
    case Macro.Env.in_guard?(__CALLER__) do
      true ->
        quote do
@@ -92,14 +92,14 @@ defmodule Record do
  ## Examples

      iex> record = {User, "john", 27}
-      iex> Record.record?(record)
+      iex> Record.is_record(record)
      true
      iex> tuple = {}
-      iex> Record.record?(tuple)
+      iex> Record.is_record(tuple)
      false

  """
-  defmacro record?(data) do
+  defmacro is_record(data) do
    case Macro.Env.in_guard?(__CALLER__) do
      true ->
        quote do
@@ -160,7 +160,7 @@ defmodule Record do
  defmacro defrecord(name, tag \\ nil, kv) do
    quote bind_quoted: [name: name, tag: tag, kv: kv] do
      tag = tag || name
-      fields = Macro.escape Record.__fields__(:defrecord, kv)
+      fields = Record.__fields__(:defrecord, kv)

      defmacro(unquote(name)(args \\ [])) do
        Record.__access__(unquote(tag), unquote(fields), args, __CALLER__)
@@ -178,7 +178,7 @@ defmodule Record do
  defmacro defrecordp(name, tag \\ nil, kv) do
    quote bind_quoted: [name: name, tag: tag, kv: kv] do
      tag = tag || name
-      fields = Macro.escape Record.__fields__(:defrecordp, kv)
+      fields = Record.__fields__(:defrecordp, kv)

      defmacrop(unquote(name)(args \\ [])) do
        Record.__access__(unquote(tag), unquote(fields), args, __CALLER__)
@@ -194,9 +194,19 @@ defmodule Record do
  @doc false
  def __fields__(type, fields) do
    :lists.map(fn
-      { key, _ } = pair when is_atom(key) -> pair
-      key when is_atom(key) -> { key, nil }
-      other -> raise ArgumentError, "#{type} fields must be atoms, got: #{inspect other}"
+      {key, val} when is_atom(key) ->
+        try do
+          Macro.escape(val)
+        rescue
+          e in [ArgumentError] ->
+            raise ArgumentError, "invalid value for record field #{key}, " <> Exception.message(e)
+        else
+          val -> {key, val}
+        end
+      key when is_atom(key) ->
+        {key, nil}
+      other ->
+        raise ArgumentError, "#{type} fields must be atoms, got: #{inspect other}"
    end, fields)
  end

@@ -309,7 +319,7 @@ defmodule Record do
  # Returns a keyword list of the record
  @doc false
  def __keyword__(atom, fields, record) do
-    if record?(record, atom) do
+    if is_record(record, atom) do
      [_tag|values] = Tuple.to_list(record)
      join_keyword(fields, values, [])
    else
@@ -45,10 +45,11 @@ defmodule Record.Extractor do
  end

  # Read a file and return its abstract syntax form that also
-  # includes record and other preprocessor modules. This is done
-  # by using Erlang's epp_dodger.
+  # includes record but with macros and other attributes expanded,
+  # such as `-include(...)` and `-include_lib(...)`. This is done
+  # by using Erlang's epp.
  defp read_file(file) do
-    case :epp_dodger.quick_parse_file(file) do
+    case :epp.parse_file(file, []) do
      {:ok, form} ->
        form
      other ->
@@ -80,11 +81,11 @@ 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
@@ -78,7 +78,7 @@ defmodule Regex do

  defstruct re_pattern: nil, source: "", opts: ""

-  @opaque t :: %__MODULE__{re_pattern: term, source: binary, opts: binary}
+  @type t :: %__MODULE__{re_pattern: term, source: binary, opts: binary}

  defmodule CompileError do
    defexception message: "regex could not be compiled"
@@ -133,6 +133,7 @@ defmodule Regex do
  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
  def compile!(source, options \\ "") do
    case compile(source, options) do
      {:ok, regex} -> regex
@@ -152,6 +153,7 @@ defmodule Regex do
      false

  """
+  @spec match?(t, String.t) :: boolean
  def match?(%Regex{re_pattern: compiled}, string) when is_binary(string) do
    :re.run(string, compiled, [{:capture, :none}]) == :match
  end
@@ -168,6 +170,8 @@ defmodule Regex do
      false

  """
+  @spec regex?(t) :: true
+  @spec regex?(any) :: false
  def regex?(%Regex{}), do: true
  def regex?(_), do: false

@@ -193,6 +197,7 @@ defmodule Regex do
      [{2,2},{3,1}]

  """
+  @spec run(t, binary, [term]) :: nil | [binary] | [{integer, integer}]
  def run(regex, string, options \\ [])

  def run(%Regex{re_pattern: compiled}, string, options) when is_binary(string) do
@@ -223,6 +228,7 @@ defmodule Regex do
      nil

  """
+  @spec named_captures(t, String.t, [term]) :: map | nil
  def named_captures(regex, string, options \\ []) when is_binary(string) do
    names = names(regex)
    options = Keyword.put(options, :capture, names)
@@ -233,6 +239,7 @@ defmodule Regex do
  @doc """
  Returns the underlying `re_pattern` in the regular expression.
  """
+  @spec re_pattern(t) :: term
  def re_pattern(%Regex{re_pattern: compiled}) do
    compiled
  end
@@ -246,6 +253,7 @@ defmodule Regex do
      "foo"

  """
+  @spec source(t) :: String.t
  def source(%Regex{source: source}) do
    source
  end
@@ -259,6 +267,7 @@ defmodule Regex do
      "m"

  """
+  @spec opts(t) :: String.t
  def opts(%Regex{opts: opts}) do
    opts
  end
@@ -272,6 +281,7 @@ defmodule Regex do
      ["foo"]

  """
+  @spec names(t) :: [String.t]
  def names(%Regex{re_pattern: re_pattern}) do
    {:namelist, names} = :re.inspect(re_pattern, :namelist)
    names
@@ -301,6 +311,7 @@ defmodule Regex do
      []

  """
+  @spec scan(t, String.t, [term]) :: [[String.t]]
  def scan(regex, string, options \\ [])

  def scan(%Regex{re_pattern: compiled}, string, options) when is_binary(string) do
@@ -353,7 +364,7 @@ defmodule Regex do
      ["a", "c"]

  """
-
+  @spec split(t, String.t, [term]) :: [String.t]
  def split(regex, string, options \\ [])

  def split(%Regex{}, "", _opts), do: [""]
@@ -408,8 +419,8 @@ defmodule Regex do

  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`, where `N` is the capture. In
-  case `\0` is used, the whole match is inserted.
+  captures to be accessed via `\N` or `\g{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
@@ -439,6 +450,7 @@ defmodule Regex do
      "[b][d]"

  """
+  @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(replacement) do
@@ -467,6 +479,11 @@ 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(<<?\\, x, rest :: binary>>) when x < ?0 or x > ?9 do
    case precompile_replacement(rest) do
      [head | t] when is_binary(head) ->
@@ -538,7 +555,7 @@ defmodule Regex do
      cond do
        is_binary(part) ->
          part
-        part > tuple_size(indexes) ->
+        part >= tuple_size(indexes) ->
          ""
        true ->
          get_index(string, elem(indexes, part))
@@ -198,7 +198,7 @@ defmodule Set do
    if target1 == target2 do
      target1.intersection(set1, set2)
    else
-      target1.reduce(set1, {:cont, Collectable.empty(set1)}, 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
@@ -156,18 +156,22 @@ defmodule Stream do
  @spec chunk(Enumerable.t, non_neg_integer, non_neg_integer, Enumerable.t | nil) :: Enumerable.t
  def chunk(enum, n, step, pad \\ nil) when n > 0 and step > 0 do
    limit = :erlang.max(n, step)
-    lazy enum, {[], 0},
-         fn(f1) -> R.chunk(n, step, limit, f1) end,
-         fn(f1) -> &do_chunk(&1, n, pad, f1) end
+    if is_nil(pad) do
+      lazy enum, {[], 0}, fn(f1) -> R.chunk(n, step, limit, f1) end
+    else
+      lazy enum, {[], 0},
+           fn(f1) -> R.chunk(n, step, limit, f1) end,
+           &do_chunk(&1, n, pad, &2)
+     end
  end

-  defp do_chunk(acc(h, {buffer, count} = old, t) = acc, n, pad, f1) do
-    if nil?(pad) || count == 0 do
-      {:cont, acc}
-    else
-      buffer = :lists.reverse(buffer) ++ Enum.take(pad, n - count)
-      cont_with_acc(f1, buffer, h, old, t)
-    end
+  defp do_chunk(acc(_, {_, 0}, _) = acc, _, _, _) do
+    {:cont, acc}
+  end
+
+  defp do_chunk(acc(h, {buffer, count} = old, t), n, pad, f1) do
+    buffer = :lists.reverse(buffer) ++ Enum.take(pad, n - count)
+    cont_with_acc(f1, buffer, h, old, t)
  end

  @doc """
@@ -186,7 +190,7 @@ defmodule Stream do
  def chunk_by(enum, fun) do
    lazy enum, nil,
         fn(f1) -> R.chunk_by(fun, f1) end,
-         fn(f1) -> &do_chunk_by(&1, f1) end
+         &do_chunk_by(&1, &2)
  end

  defp do_chunk_by(acc(_, nil, _) = acc, _f1) do
@@ -338,6 +342,25 @@ defmodule Stream do
    lazy enum, fn(f1) -> R.filter_map(filter, mapper, f1) end
  end

+  @doc """
+  Creates a stream that emits a value every `n` milliseconds.
+
+  The values emitted are an increasing counter starting at `0`.
+
+  ## Examples
+
+      iex> Stream.interval(10) |> Enum.take(10)
+      [0,1,2,3,4,5,6,7,8,9]
+
+  """
+  @spec interval(non_neg_integer) :: Enumerable.t
+  def interval(n) do
+    unfold 0, fn (count) ->
+      :timer.sleep(n)
+      {count, count + 1}
+    end
+  end
+
  @doc """
  Injects the stream values into the given collectable as a side-effect.

@@ -495,11 +518,11 @@ defmodule Stream do
  @spec take(Enumerable.t, non_neg_integer) :: Enumerable.t
  def take(_enum, 0), do: %Stream{enum: []}

-  def take(enum, n) when n > 0 do
+  def take(enum, n) when n > 0 and is_integer(n) do
    lazy enum, n, fn(f1) -> R.take(f1) end
  end

-  def take(enum, n) when n < 0 do
+  def take(enum, n) when n < 0 and is_integer(n) do
    &do_take(enum, abs(n), &1, &2)
  end

@@ -563,6 +586,22 @@ defmodule Stream do
    lazy enum, fn(f1) -> R.take_while(fun, f1) end
  end

+  @doc """
+  Creates a stream that emits a single value after `n` milliseconds.
+
+  The value emitted is `0`.
+
+  ## Examples
+
+      iex> Stream.timer(10) |> Enum.to_list
+      [0]
+
+  """
+  @spec timer(non_neg_integer) :: Enumerable.t
+  def timer(n) do
+    take(interval(n), 1)
+  end
+
  @doc """
  Transforms an existing stream.

@@ -577,7 +616,7 @@ defmodule Stream do

  ## Examples

-  `Stream.transform/3` is a useful as it can be used as basis to implement
+  `Stream.transform/3` is useful as it can be used as the basis to implement
  many of the functions defined in this module. For example, we can implement
  `Stream.take(enum, n)` as follows:

@@ -660,9 +699,11 @@ defmodule Stream do
        next.({:halt, next_acc})
        :erlang.raise(kind, reason, stacktrace)
    else
-      {:halted, [:outer|acc]} ->
+      # Only take into account outer halts when the op is not halt itself.
+      # Otherwise, we were the ones wishing to halt, so we should just stop.
+      {:halted, [:outer|acc]} when op != :halt ->
        do_transform(user_acc, user, fun, next_acc, next, {:cont, acc}, inner)
-      {:halted, [:inner|acc]} ->
+      {:halted, [_|acc]} ->
        next.({:halt, next_acc})
        {:halted, acc}
      {:done, [_|acc]} ->
@@ -847,6 +888,15 @@ defmodule Stream do

  """
  @spec cycle(Enumerable.t) :: Enumerable.t
+  def cycle(enumerable)
+
+  def cycle(enumerable) when is_list(enumerable) do
+    unfold {enumerable, enumerable}, fn
+      {source, [h | t]}      -> {h, {source, t}}
+      {source = [h | t], []} -> {h, {source, t}}
+    end
+  end
+
  def cycle(enumerable) do
    fn acc, fun ->
      inner = &do_cycle_each(&1, &2, fun)
@@ -934,14 +984,15 @@ defmodule Stream do
  @doc """
  Emits a sequence of values for the given resource.

-  Similar to `unfold/2` but the initial value is computed lazily via
-  `start_fun` and executes an `after_fun` at the end of enumeration
-  (both in cases of success and failure).
+  Similar to `transform/2` but the initial accumulated value is
+  computed lazily via `start_fun` and executes an `after_fun` at
+  the end of enumeration (both in cases of success and failure).

  Successive values are generated by calling `next_fun` with the
  previous accumulator (the initial value being the result returned
-  by `start_fun`) and it must return a tuple with the current and
-  next accumulator. The enumeration finishes if it returns `nil`.
+  by `start_fun`) and it must return a tuple containing a list
+  of items to be emitted and the next accumulator. The enumeration
+  finishes if it returns `{:halt, acc}`.

  As the name says, this function is useful to stream values from
  resources.
@@ -951,8 +1002,8 @@ defmodule Stream do
      Stream.resource(fn -> File.open!("sample") end,
                      fn file ->
                        case IO.read(file, :line) do
-                          data when is_binary(data) -> {data, file}
-                          _ -> nil
+                          data when is_binary(data) -> {[data], file}
+                          _ -> {:halt, file}
                        end
                      end,
                      fn file -> File.close(file) end)
@@ -974,9 +1025,11 @@ defmodule Stream do

  defp do_resource(next_acc, next_fun, {:cont, acc}, fun, after_fun) do
    try do
+      # Optimize the most common cases
      case next_fun.(next_acc) do
-        nil -> nil
-        {v, next_acc} -> {fun.(v, acc), next_acc}
+        {[], next_acc}  -> {:opt, {:cont, acc}, next_acc}
+        {[v], next_acc} -> {:opt, fun.(v, acc), next_acc}
+        {_, _} = other  -> other
      end
    catch
      kind, reason ->
@@ -984,11 +1037,62 @@ defmodule Stream do
        after_fun.(next_acc)
        :erlang.raise(kind, reason, stacktrace)
    else
-      nil ->
-        after_fun.(next_acc)
-        {:done, acc}
-      {acc, next_acc} ->
+      {:opt, acc, next_acc} ->
        do_resource(next_acc, next_fun, acc, fun, after_fun)
+      {:halt, next_acc} ->
+        do_resource(next_acc, next_fun, {:halt, acc}, fun, after_fun)
+      {list, next_acc} when is_list(list) ->
+        do_list_resource(next_acc, next_fun, {:cont, acc}, fun, after_fun,
+                         &Enumerable.List.reduce(list, &1, fun))
+      {enum, next_acc} ->
+        inner = &do_resource_each(&1, &2, fun)
+        do_enum_resource(next_acc, next_fun, {:cont, acc}, fun, after_fun,
+                         &Enumerable.reduce(enum, &1, inner))
+    end
+  end
+
+  defp do_list_resource(next_acc, next_fun, acc, fun, after_fun, reduce) do
+    try do
+      reduce.(acc)
+    catch
+      kind, reason ->
+        stacktrace = System.stacktrace
+        after_fun.(next_acc)
+        :erlang.raise(kind, reason, stacktrace)
+    else
+      {:done, acc} ->
+        do_resource(next_acc, next_fun, {:cont, acc}, fun, after_fun)
+      {:halted, acc} ->
+        do_resource(next_acc, next_fun, {:halt, acc}, fun, after_fun)
+      {:suspended, acc, c} ->
+        {:suspended, acc, &do_list_resource(next_acc, next_fun, &1, fun, after_fun, c)}
+    end
+  end
+
+  defp do_enum_resource(next_acc, next_fun, {op, acc}, fun, after_fun, reduce) do
+    try do
+      reduce.({op, [:outer|acc]})
+    catch
+      kind, reason ->
+        stacktrace = System.stacktrace
+        after_fun.(next_acc)
+        :erlang.raise(kind, reason, stacktrace)
+    else
+      {:halted, [:outer|acc]} ->
+        do_resource(next_acc, next_fun, {:cont, acc}, fun, after_fun)
+      {:halted, [:inner|acc]} ->
+        do_resource(next_acc, next_fun, {:halt, acc}, fun, after_fun)
+      {:done, [_|acc]} ->
+        do_resource(next_acc, next_fun, {:cont, acc}, fun, after_fun)
+      {:suspended, [_|acc], c} ->
+        {:suspended, acc, &do_enum_resource(next_acc, next_fun, &1, fun, after_fun, c)}
+    end
+  end
+
+  defp do_resource_each(x, [:outer|acc], f) do
+    case f.(x, acc) do
+      {:halt, res} -> {:halt, [:inner|res]}
+      {op, res}    -> {op, [:outer|res]}
    end
  end

@@ -1029,12 +1133,12 @@ defmodule Stream do

  @compile {:inline, lazy: 2, lazy: 3, lazy: 4}

-  defp lazy(%Stream{funs: funs} = lazy, fun),
+  defp lazy(%Stream{done: nil, funs: funs} = lazy, fun),
    do: %{lazy | funs: [fun|funs] }
  defp lazy(enum, fun),
    do: %Stream{enum: enum, funs: [fun]}

-  defp lazy(%Stream{funs: funs, accs: accs} = lazy, acc, fun),
+  defp lazy(%Stream{done: nil, funs: funs, accs: accs} = lazy, acc, fun),
    do: %{lazy | funs: [fun|funs], accs: [acc|accs] }
  defp lazy(enum, acc, fun),
    do: %Stream{enum: enum, funs: [fun], accs: [acc]}
@@ -1073,19 +1177,20 @@ defimpl Enumerable, for: Stream do
    case reduce.({command, [acc|accs]}) do
      {:suspended, [acc|accs], continuation} ->
        {:suspended, acc, &do_each(continuation, done, accs, &1)}
-      {:halted, [acc|_]} ->
-        {:halted, acc}
-      {:done, [acc|_] = accs} ->
-        case done do
-          nil ->
-            {:done, acc}
-          {done, fun} ->
-            case done.(fun).(accs) do
-              {:cont, [acc|_]}    -> {:done, acc}
-              {:halt, [acc|_]}    -> {:halted, acc}
-              {:suspend, [acc|_]} -> {:suspended, acc, &({:done, elem(&1, 1)})}
-            end
-        end
+      {:halted, accs} ->
+        do_done {:halted, accs}, done
+      {:done, accs} ->
+        do_done {:done, accs}, done
+    end
+  end
+
+  defp do_done({reason, [acc|_]}, nil), do: {reason, acc}
+  defp do_done({reason, [acc|t]}, {done, fun}) do
+    [h|_] = Enum.reverse(t)
+    case done.([acc, h], fun) do
+      {:cont, [acc|_]}    -> {reason, acc}
+      {:halt, [acc|_]}    -> {:halted, acc}
+      {:suspend, [acc|_]} -> {:suspended, acc, &({:done, elem(&1, 1)})}
    end
  end
 end
@@ -132,10 +132,16 @@ defmodule Stream.Reducers do
  defmacro take(f \\ nil) do
    quote do
      fn(entry, acc(h, n, t) = orig) ->
-        if n >= 1 do
-          cont_with_acc(unquote(f), entry, h, n-1, t)
-        else
-          {:halt, orig}
+        case n do
+          0 ->
+            {:halt, orig}
+          1 ->
+            case cont_with_acc(unquote(f), entry, h, n-1, t) do
+              {:cont, acc} -> {:halt, acc}
+              reason -> reason
+            end
+          _ ->
+            cont_with_acc(unquote(f), entry, h, n-1, t)
        end
      end
    end
@@ -4,28 +4,12 @@ defmodule String do
  @moduledoc ~S"""
  A String in Elixir is a UTF-8 encoded binary.

-  ## String and binary operations
-
-  The functions in this module act according to the
-  Unicode Standard, version 6.3.0. For example,
-  `capitalize/1`, `downcase/1`, `strip/1` are provided by this
-  module.
-
-  In addition to this module, Elixir provides more low-level
-  operations that work directly with binaries. Some
-  of those can be found in the `Kernel` module, as:
-
-    * `Kernel.binary_part/3` - retrieves part of the binary
-    * `Kernel.bit_size/1` and `Kernel.byte_size/1` - size related functions
-    * `Kernel.is_bitstring/1` and `Kernel.is_binary/1` - type checking function
-    * Plus a number of functions for working with binaries (bytes)
-      [in the `:binary` module](http://erlang.org/doc/man/binary.html)
-
  ## Codepoints and graphemes

-  As per the Unicode Standard, a codepoint is an Unicode
-  Character, which may be represented by one or more bytes.
-  For example, the character "é" is represented with two
+  The functions in this module act according to the Unicode
+  Standard, version 6.3.0.As per the standard, a codepoint is
+  an Unicode Character, which may be represented by one or more
+  bytes. For example, the character "é" is represented with two
  bytes:

      iex> byte_size("é")
@@ -66,6 +50,82 @@ defmodule String do
  This current Elixir version implements Extended Grapheme Cluster
  algorithm.

+  ## String and binary operations
+
+  To act accordingly to the Unicode Standard, many functions
+  in this module runs in linear time, as it needs to traverse
+  the whole string considering the proper Unicode codepoints.
+
+  For example, `String.length/1` is going to take longer as
+  the input grows. On the other hand, `byte_size/1` always runs
+  in constant time (i.e. regardless of the input size).
+
+  This means often there are performance costs in using the
+  functions in this module, compared to the more low-level
+  operations that work directly with binaries:
+
+    * `Kernel.binary_part/3` - retrieves part of the binary
+    * `Kernel.bit_size/1` and `Kernel.byte_size/1` - size related functions
+    * `Kernel.is_bitstring/1` and `Kernel.is_binary/1` - type checking function
+    * Plus a number of functions for working with binaries (bytes)
+      [in the `:binary` module](http://erlang.org/doc/man/binary.html)
+
+  There are many situations where using the `String` module can
+  be avoided in favor of binary functions or pattern matching.
+  For example, imagine you have a string `prefix` and you want to
+  remove this prefix from another string named `full`.
+
+  One may be tempted to write:
+
+      iex> take_prefix = fn full, prefix ->
+      ...>   base = String.length(prefix)
+      ...>   String.slice(full, base, String.length(full) - base)
+      ...> end
+      ...> take_prefix.("Mr. John", "Mr. ")
+      "John"
+
+  Although the function above works, it performs poorly. To
+  calculate the length of the string, we need to traverse it
+  fully, so we traverse both `prefix` and `full` strings, then
+  slice the `full` one, traversing it again.
+
+  A first attempting at improving it could be with ranges:
+
+      iex> take_prefix = fn full, prefix ->
+      ...>   base = String.length(prefix)
+      ...>   String.slice(full, base..-1)
+      ...> end
+      ...> take_prefix.("Mr. John", "Mr. ")
+      "John"
+
+  While this is much better (we don't traverse `full` twice),
+  it could still be improved. In this case, since we want to
+  extract a substring from a string, we can use `byte_size/1`
+  and `binary_part/3` as there is no chance we will slice in
+  the middle of a codepoint made of more than one byte:
+
+      iex> take_prefix = fn full, prefix ->
+      ...>   base = byte_size(prefix)
+      ...>   binary_part(full, base, byte_size(full) - base)
+      ...> end
+      ...> take_prefix.("Mr. John", "Mr. ")
+      "John"
+
+  Or simply used pattern matching:
+
+      iex> take_prefix = fn full, prefix ->
+      ...>   base = byte_size(prefix)
+      ...>   <<_ :: binary-size(base), rest :: binary>> = full
+      ...>   rest
+      ...> end
+      ...> take_prefix.("Mr. John", "Mr. ")
+      "John"
+
+  On the other hand, if you want to dynamically slice a string
+  based on an integer value, then using `String.slice/3` is the
+  best option as it guarantees we won't incorrectly split a valid
+  codepoint in multiple bytes.
+
  ## Integer codepoints

  Although codepoints could be represented as integers, this
@@ -590,13 +650,14 @@ defmodule String do
      iex> String.replace("a,b,c", ",", "-", global: false)
      "a-b,c"

-  The pattern can also be a regex. In those cases, one can give `\N`
-  in the `replacement` string to access a specific capture in the regex:
+  The pattern can also be a regex. In those cases, one can give `\N` or
+  `\g{N}` in the `replacement` string to access a specific capture in the
+  regex:

      iex> String.replace("a,b,c", ~r/,(.)/, ",\\1\\1")
      "a,bb,cc"

-  Notice we had to escape the escape character `\`. By giving `&`,
+  Notice we had to escape the escape character `\`. By giving `\0`,
  one can inject the whole matched pattern in the replacement string.

  When strings are used as a pattern, a developer can also use the
@@ -612,8 +673,8 @@ defmodule String do
      "a[,,]b[,,]c"

  """
-  @spec replace(t, t, t) :: t
-  @spec replace(t, t, t, Keyword.t) :: t
+  @spec replace(t, t | Regex.t, t) :: t
+  @spec replace(t, t | Regex.t, t, Keyword.t) :: t

  def replace(subject, pattern, replacement, options \\ []) when is_binary(replacement) do
    if Regex.regex?(pattern) do
@@ -1363,7 +1424,7 @@ defmodule String do
      1023

  """
-  @spec to_integer(String.t, pos_integer) :: integer
+  @spec to_integer(String.t, 2..36) :: integer
  def to_integer(string, base) do
    :erlang.binary_to_integer(string, base)
  end
@@ -36,7 +36,7 @@ defmodule StringIO do
  """
  @spec open(binary, Keyword.t) :: {:ok, pid}
  def open(string, options \\ []) when is_binary(string) do
-    :gen_server.start_link(__MODULE__, {string, options}, [])
+    GenServer.start_link(__MODULE__, {string, options}, [])
  end

  @doc """
@@ -52,7 +52,7 @@ defmodule StringIO do
  """
  @spec contents(pid) :: {binary, binary}
  def contents(pid) when is_pid(pid) do
-    :gen_server.call(pid, :contents)
+    GenServer.call(pid, :contents)
  end

  @doc """
@@ -68,7 +68,7 @@ defmodule StringIO do
  """
  @spec close(pid) :: {:ok, {binary, binary}}
  def close(pid) when is_pid(pid) do
-    :gen_server.call(pid, :close)
+    GenServer.call(pid, :close)
  end

  ## callbacks
@@ -20,8 +20,8 @@ defmodule Supervisor do
      defmodule Stack do
        use GenServer

-        def start_link(state) do
-          GenServer.start_link(__MODULE__, state, [name: :sup_stack])
+        def start_link(state, opts) do
+          GenServer.start_link(__MODULE__, state, opts)
        end

        def handle_call(:pop, _from, [h|t]) do
@@ -38,16 +38,17 @@ defmodule Supervisor do
      # Import helpers for defining supervisors
      import Supervisor.Spec

-      # We are going to supervise the Stack server which will
-      # be started with a single argument [:hello]
+      # We are going to supervise the Stack server which
+      # will be started with a single argument [:hello]
+      # and the default name of :sup_stack.
      children = [
-        worker(Stack, [[:hello]])
+        worker(Stack, [[:hello], [name: :sup_stack]])
      ]

      # Start the supervisor with our one child
      {:ok, pid} = Supervisor.start_link(children, strategy: :one_for_one)

-  Notice that when starting the GenServer, we have registered it
+  Notice that when starting the GenServer, we are registering it
  with name `:sup_stack`, which allows us to call it directly and
  get what is on the stack:

@@ -65,7 +66,7 @@ defmodule Supervisor do
  Let's try it:

      GenServer.call(:sup_stack, :pop)
-      =ERROR REPORT====
+      ** (exit) exited in: GenServer.call(:sup_stack, :pop, 5000)

  Luckily, since the server is being supervised by a supervisor, the
  supervisor will automatically start a new one, with the default stack
@@ -132,10 +133,74 @@ defmodule Supervisor do

    * `:simple_one_for_one` - similar to `:one_for_one` but suits better
      when dynamically attaching children. This strategy requires the
-      supervisor specification to contain only one children. Many functions
+      supervisor specification to contain only one child. Many functions
      in this module behave slightly differently when this strategy is
      used.

+  ## Simple one for one
+
+  The simple one for one supervisor is useful when you want to dynamically
+  start and stop supervisor children. For example, imagine you want to
+  dynamically create multiple stacks. We can do so by defining a simple one
+  for one supervisor:
+
+      # Import helpers for defining supervisors
+      import Supervisor.Spec
+
+      # This time, we don't pass any argument because
+      # the argument will be given when we start the child
+      children = [
+        worker(Stack, [], restart: :transient)
+      ]
+
+      # Start the supervisor with our one child
+      {:ok, sup_pid} = Supervisor.start_link(children, strategy: :simple_one_for_one)
+
+  There are a couple differences here:
+
+    * The simple one for one specification can define only one child which
+      works as a template for when we call `start_child/2`
+
+    * We have define the child to have restart strategy of transient. This
+      means that, if the child process exits due to a `:normal`, `:shutdown`
+      or `{:shutdown, term}` reason, it won't be restarted. This is useful
+      as it allows our workers to politely shutdown and be removed from the
+      simple one for one supervisor, without being restarted. You can find
+      more information about restart strategies on `Supervisor.Spec`
+
+  With the supervisor defined, let's dynamically start stacks:
+
+      {:ok, pid} = Supervisor.start_child(sup_pid, [[:hello, :world], []])
+      GenServer.call(pid, :pop) #=> :hello
+      GenServer.call(pid, :pop) #=> :world
+
+      {:ok, pid} = Supervisor.start_child(sup_pid, [[:something, :else], []])
+      GenServer.call(pid, :pop) #=> :something
+      GenServer.call(pid, :pop) #=> :else
+
+      Supervisor.count_children(sup_pid)
+      #=> %{active: 2, specs: 1, supervisors: 0, workers: 2}
+
+  ## Exit reasons
+
+  From the example above, you may have noticed that the transient restart
+  strategy for the worker does not restart the child in case it crashes with
+  reason `:normal`, `:shutdown` or `{:shutdown, term}`.
+
+  So one may ask: which exit reason should I choose when existing my worker?
+  There are three options:
+
+    * `:normal` - on such cases, the exit won't be logged, there is no restart
+      on transient mode and linked processes do not exit
+
+    * `:shutdown` or `{:shutdown, term}` - on such cases, the exit won't be
+      logged, there is no restart on transient mode and linked processes exit
+      with the same reason unless trapping exits
+
+    * any other term - on such cases, the exit will be logged, there are
+      restarts on transient mode and linked processes exit with the same reason
+      unless trapping exits
+
  ## Name Registration

  A supervisor is bound to the same name registration rules as a `GenServer`.
@@ -268,7 +333,9 @@ defmodule Supervisor do
  and child specification.
  """
  @spec start_child(supervisor, Supervisor.Spec.spec | [term]) :: on_start_child
-  defdelegate start_child(supervisor, child_spec_or_args), to: :supervisor
+  def start_child(supervisor, child_spec_or_args) do
+    call(supervisor, {:start_child, child_spec_or_args})
+  end

  @doc """
  Terminates the given pid or child id.
@@ -290,7 +357,9 @@ defmodule Supervisor do
  """
  @spec terminate_child(supervisor, pid | Supervisor.Spec.child_id) :: :ok | {:error, error}
        when error: :not_found | :simple_one_for_one
-  defdelegate terminate_child(supervisor, pid_or_child_id), to: :supervisor
+  def terminate_child(supervisor, pid_or_child_id) do
+    call(supervisor, {:terminate_child, pid_or_child_id})
+  end

  @doc """
  Deletes the child specification identified by `child_id`.
@@ -306,7 +375,9 @@ defmodule Supervisor do
  """
  @spec delete_child(supervisor, Supervisor.Spec.child_id) :: :ok | {:error, error}
        when error: :not_found | :simple_one_for_one | :running | :restarting
-  defdelegate delete_child(supervisor, child_id), to: :supervisor
+  def delete_child(supervisor, child_id) do
+    call(supervisor, {:delete_child, child_id})
+  end

  @doc """
  Restarts a child process identified by `child_id`.
@@ -335,7 +406,9 @@ defmodule Supervisor do
  @spec restart_child(supervisor, Supervisor.Spec.child_id) ::
        {:ok, child} | {:ok, child, term} | {:error, error}
        when error: :not_found | :simple_one_for_one | :running | :restarting | term
-  defdelegate restart_child(supervisor, child_id), to: :supervisor
+  def restart_child(supervisor, child_id) do
+    call(supervisor, {:restart_child, child_id})
+  end

  @doc """
  Returns a list with information about all children.
@@ -361,7 +434,9 @@ defmodule Supervisor do
           child | :restarting,
           Supervisor.Spec.worker,
           Supervisor.Spec.modules}]
-  defdelegate which_children(supervisor), to: :supervisor
+  def which_children(supervisor) do
+    call(supervisor, :which_children)
+  end

  @doc """
  Returns a map containing count values for the supervisor.
@@ -381,9 +456,15 @@ defmodule Supervisor do

  """
  @spec count_children(supervisor) ::
-        [specs: non_neg_integer, active: non_neg_integer,
-         supervisors: non_neg_integer, workers: non_neg_integer]
+        %{specs: non_neg_integer, active: non_neg_integer,
+          supervisors: non_neg_integer, workers: non_neg_integer}
  def count_children(supervisor) do
-    :supervisor.count_children(supervisor) |> :maps.from_list
+    call(supervisor, :count_children) |> :maps.from_list
+  end
+
+  @compile {:inline, call: 2}
+
+  defp call(supervisor, req) do
+    GenServer.call(supervisor, req, :infinity)
  end
 end
@@ -145,12 +145,12 @@ defmodule Supervisor.Spec do
      in the `Supervisor` module docs.

    * `:max_restarts` - the maximum amount of restarts allowed in
-      a time frame. Defaults to 5.
+      a time frame. Defaults to 3.

    * `:max_seconds` - the time frame in which `:max_restarts` applies.
      Defaults to 5.

-  The `:strategy` option is required and by default maximum 5 restarts
+  The `:strategy` option is required and by default maximum 3 restarts
  are allowed within 5 seconds. Please check the `Supervisor` module for
  a complete description of the available strategies.
  """
@@ -162,7 +162,7 @@ defmodule Supervisor.Spec do
      raise ArgumentError, "expected :strategy option to be given"
    end

-    maxR = Keyword.get(options, :max_restarts, 5)
+    maxR = Keyword.get(options, :max_restarts, 3)
    maxS = Keyword.get(options, :max_seconds, 5)

    assert_unique_ids(Enum.map(children, &elem(&1, 0)))
@@ -72,7 +72,7 @@ defmodule System do
  """
  @spec argv() :: [String.t]
  def argv do
-    :elixir_code_server.call :argv
+    :elixir_config.get(:argv)
  end

  @doc """
@@ -83,7 +83,7 @@ defmodule System do
  """
  @spec argv([String.t]) :: :ok
  def argv(args) do
-    :elixir_code_server.cast({:argv, args})
+    :elixir_config.put(:argv, args)
  end

  @doc """
@@ -94,11 +94,20 @@ defmodule System do
  """
  def cwd do
    case :file.get_cwd do
-      {:ok, base} -> IO.chardata_to_string(base)
+      {:ok, base} -> IO.chardata_to_string(fix_drive_letter(base))
      _ -> nil
    end
  end

+  defp fix_drive_letter([l, ?:, ?/ | rest] = original) when l in ?A..?Z do
+    case :os.type() do
+      {:win32, _} -> [l+?a-?A, ?:, ?/ | rest]
+      _ -> original
+    end
+  end
+
+  defp fix_drive_letter(original), do: original
+
  @doc """
  Current working directory, exception on error.

@@ -215,16 +224,7 @@ defmodule System do
  The function must receive the exit status code as an argument.
  """
  def at_exit(fun) when is_function(fun, 1) do
-    :elixir_code_server.cast {:at_exit, fun}
-  end
-
-  @doc false
-  def cmd(command) when is_list(command) do
-    :os.cmd(command)
-  end
-
-  def cmd(command) when is_binary(command) do
-    List.to_string :os.cmd(String.to_char_list(command))
+    :elixir_config.update :at_exit, &[fun|&1]
  end

  @doc """
@@ -431,18 +431,18 @@ defmodule System do
  @spec cmd(binary, [binary], Keyword.t) ::
        {Collectable.t, exit_status :: non_neg_integer}
  def cmd(command, args, opts \\ []) when is_binary(command) and is_list(args) do
-    command = String.to_char_list(command)
+    cmd = String.to_char_list(command)

-    command =
-      if Path.type(command) == :absolute do
-        command
+    cmd =
+      if Path.type(cmd) == :absolute do
+        cmd
      else
-        :os.find_executable(command) || command
+        :os.find_executable(cmd) || :erlang.error(:enoent, [command, args, opts])
      end

    {into, opts} = cmd_opts(opts, [:use_stdio, :exit_status, :binary, :hide, args: args], "")
    {initial, fun} = Collectable.into(into)
-    do_cmd Port.open({:spawn_executable, command}, opts), initial, fun
+    do_cmd Port.open({:spawn_executable, cmd}, opts), initial, fun
  end

  defp do_cmd(port, acc, fun) do
@@ -463,9 +463,12 @@ defmodule System do
  defp cmd_opts([{:arg0, bin}|t], opts, into) when is_binary(bin),
    do: cmd_opts(t, [{:arg0, bin}|opts], into)

-  defp cmd_opts([{:stderr_to_stdout, bool}|t], opts, into) when is_boolean(bool),
+  defp cmd_opts([{:stderr_to_stdout, true}|t], opts, into),
    do: cmd_opts(t, [:stderr_to_stdout|opts], into)

+  defp cmd_opts([{:stderr_to_stdout, false}|t], opts, into),
+    do: cmd_opts(t, opts, into)
+
  defp cmd_opts([{:parallelism, bool}|t], opts, into) when is_boolean(bool),
    do: cmd_opts(t, [{:parallelism, bool}|opts], into)

@@ -77,8 +77,8 @@ defmodule Task do
        supervisor(Task.Supervisor, [[name: :tasks_sup]])
      ]

-  Note that, when working with distributed tasks, one should use the `async/4` API,
-  that expects explicit module, function and arguments, instead of `async/2` that
+  Note that, when working with distributed tasks, one should use the `async/3` API,
+  that expects explicit module, function and arguments, instead of `async/1` that
  works with anonymous functions. That's because the anonymous function API expects
  the same module version to exist on all involved nodes. Check the `Agent` module
  documentation for more information on distributed processes, as the limitations
@@ -119,6 +119,30 @@ defmodule Task do
    Task.Supervised.start_link(get_info(self), {mod, fun, args})
  end

+  @doc """
+  Starts a task.
+
+  This is only used when the task is used for side-effects
+  (i.e. no interest in its return result) and it should not
+  be linked to the current process.
+  """
+  @spec start(fun) :: {:ok, pid}
+  def start(fun) do
+    start(:erlang, :apply, [fun, []])
+  end
+
+  @doc """
+  Starts a task.
+
+  This is only used when the task is used for side-effects
+  (i.e. no interest in its return result) and it should not
+  be linked to the current process.
+  """
+  @spec start(module, atom, [term]) :: {:ok, pid}
+  def start(mod, fun, args) do
+    Task.Supervised.start(get_info(self), {mod, fun, args})
+  end
+
  @doc """
  Starts a task that can be awaited on.

@@ -160,7 +184,7 @@ defmodule Task do
  end

  @doc """
-  Awaits for a task reply.
+  Awaits a task reply.

  A timeout, in milliseconds, can be given with default value
  of `5000`. In case the task process dies, this function will
@@ -1,6 +1,10 @@
 defmodule Task.Supervised do
  @moduledoc false

+  def start(info, fun) do
+    {:ok, :proc_lib.spawn(__MODULE__, :noreply, [info, fun])}
+  end
+
  def start_link(info, fun) do
    {:ok, :proc_lib.spawn_link(__MODULE__, :noreply, [info, fun])}
  end
@@ -25,14 +25,23 @@ defmodule Task.Supervisor do
    described under the `Name Registration` section in the `GenServer` module
    docs;

+  * `:restart` - the restart strategy, may be `:temporary` (the default),
+    `:transient` or `:permanent`. Check `Supervisor.Spec` for more info.
+    Defaults to temporary as most tasks can't be effectively restarted after
+    a crash;
+
  * `:shutdown` - `:brutal_kill` if the tasks must be killed directly on shutdown
    or an integer indicating the timeout value, defaults to 5000 milliseconds;
+
+  * `:max_restarts` and `:max_seconds` - as specified in `Supervisor.Spec.supervise/2`;
+
  """
  @spec start_link(Supervisor.options) :: Supervisor.on_start
  def start_link(opts \\ []) do
    import Supervisor.Spec
+    {restart, opts}  = Keyword.pop(opts, :restart, :temporary)
    {shutdown, opts} = Keyword.pop(opts, :shutdown, 5000)
-    children = [worker(Task.Supervised, [], restart: :temporary, shutdown: shutdown)]
+    children = [worker(Task.Supervised, [], restart: restart, shutdown: shutdown)]
    Supervisor.start_link(children, [strategy: :simple_one_for_one] ++ opts)
  end

@@ -11,18 +11,17 @@ defmodule URI do

  import Bitwise

-  @ports %{
-    "ftp"   => 21,
-    "http"  => 80,
-    "https" => 443,
-    "ldap"  => 389,
-    "sftp"  => 22,
-    "tftp"  => 69,
-  }
+  @schemes [
+    "ftp",
+    "http",
+    "https",
+    "ldap",
+    "sftp",
+    "tftp",
+  ]

-  Enum.each @ports, fn {scheme, port} ->
+  Enum.each @schemes, fn scheme ->
    def normalize_scheme(unquote(scheme)), do: unquote(scheme)
-    def default_port(unquote(scheme)),     do: unquote(port)
  end

  @doc """
@@ -47,8 +46,7 @@ defmodule URI do

  """
  def default_port(scheme) when is_binary(scheme) do
-    {:ok, dict} = Application.fetch_env(:elixir, :uri)
-    Map.get(dict, scheme)
+    :elixir_config.get({:uri, scheme})
  end

  @doc """
@@ -59,8 +57,7 @@ defmodule URI do
  new URIs.
  """
  def default_port(scheme, port) when is_binary(scheme) and port > 0 do
-    {:ok, dict} = Application.fetch_env(:elixir, :uri)
-    Application.put_env(:elixir, :uri, Map.put(dict, scheme, port), persistent: true)
+    :elixir_config.put({:uri, scheme}, port)
  end

  @doc """
@@ -68,7 +65,7 @@ defmodule URI do

  Takes an enumerable (containing a sequence of two-item tuples)
  and returns a string of the form "key1=value1&key2=value2..." where
-  keys and values are URL encoded as per `encode/1`.
+  keys and values are URL encoded as per `encode/2`.

  Keys and values can be any term that implements the `String.Chars`
  protocol, except lists which are explicitly forbidden.
@@ -98,7 +95,10 @@ defmodule URI do

  """
  def decode_query(q, dict \\ %{}) when is_binary(q) do
-    Enum.reduce query_decoder(q), dict, fn({k, v}, acc) -> Dict.put(acc, k, v) end
+    case do_decode_query(q) do
+      nil         -> dict
+      {{k, v}, q} -> decode_query(q, Dict.put(dict, k, v))
+    end
  end

  @doc """
@@ -107,19 +107,19 @@ defmodule URI do

  ## Examples

-      iex> URI.query_decoder("foo=1&bar=2") |> Enum.map &(&1)
+      iex> URI.query_decoder("foo=1&bar=2") |> Enum.map(&(&1))
      [{"foo", "1"}, {"bar", "2"}]

  """
  def query_decoder(q) when is_binary(q) do
-    Stream.unfold(q, &do_decoder/1)
+    Stream.unfold(q, &do_decode_query/1)
  end

-  defp do_decoder("") do
+  defp do_decode_query("") do
    nil
  end

-  defp do_decoder(q) do
+  defp do_decode_query(q) do
    {first, next} =
      case :binary.split(q, "&") do
        [first, rest] -> {first, rest}
@@ -234,7 +234,7 @@ defmodule URI do

  """
  def decode(uri) do
-    unpercent(uri)
+    unpercent(uri, "", false)
  catch
    :malformed_uri ->
      raise ArgumentError, "malformed URI #{inspect uri}"
@@ -250,23 +250,25 @@ defmodule URI do

  """
  def decode_www_form(str) do
-    String.split(str, "+") |> Enum.map_join(" ", &unpercent/1)
+    unpercent(str, "", true)
  catch
    :malformed_uri ->
      raise ArgumentError, "malformed URI #{inspect str}"
  end

-  defp unpercent(<<?%, hex_1, hex_2, tail :: binary>>) do
-    <<bsl(hex_to_dec(hex_1), 4) + hex_to_dec(hex_2)>> <> unpercent(tail)
-  end
-  defp unpercent(<<?%, _>>), do: throw(:malformed_uri)
-  defp unpercent(<<?%>>),    do: throw(:malformed_uri)
-
-  defp unpercent(<<head, tail :: binary>>) do
-    <<head>> <> unpercent(tail)
+  defp unpercent(<<?+, tail::binary>>, acc, spaces = true) do
+    unpercent(tail, <<acc::binary, ?\s>>, spaces)
  end

-  defp unpercent(<<>>), do: <<>>
+  defp unpercent(<<?%, hex_1, hex_2, tail::binary>>, acc, spaces) do
+    unpercent(tail, <<acc::binary, bsl(hex_to_dec(hex_1), 4) + hex_to_dec(hex_2)>>, spaces)
+  end
+  defp unpercent(<<?%, _::binary>>, _acc, _spaces), do: throw(:malformed_uri)
+
+  defp unpercent(<<head, tail::binary>>, acc, spaces) do
+    unpercent(tail, <<acc::binary, head>>, spaces)
+  end
+  defp unpercent(<<>>, acc, _spaces), do: acc

  defp hex_to_dec(n) when n in ?A..?F, do: n - ?A + 10
  defp hex_to_dec(n) when n in ?a..?f, do: n - ?a + 10
@@ -274,12 +276,17 @@ defmodule URI do
  defp hex_to_dec(_n), do: throw(:malformed_uri)

  @doc """
-  Parses a URI into components.
+  Parses a well-formed URI reference into its components.

-  URIs have portions that are handled specially for the particular
-  scheme of the URI. For example, http and https have different
-  default ports. Such values can be accessed and registered via
-  `URI.default_port/1` and `URI.default_port/2`.
+  Note this function expects a well-formed URI and does not perform
+  any validation. See the examples section below of how `URI.parse/1`
+  can be used to parse a wide range of relative URIs.
+
+  This function uses the parsing regular expression as defined
+  in the Appendix B of RFC3986.
+
+  When a URI is given without a port, the values registered via
+  `URI.default_port/1` and `URI.default_port/2` are used.

  ## Examples

@@ -288,12 +295,24 @@ defmodule URI do
           authority: "elixir-lang.org", userinfo: nil,
           host: "elixir-lang.org", port: 80}

+      iex> URI.parse("//elixir-lang.org/")
+      %URI{authority: "elixir-lang.org", fragment: nil, host: "elixir-lang.org",
+           path: "/", port: nil, query: nil, scheme: nil, userinfo: nil}
+
+      iex> URI.parse("/foo/bar")
+      %URI{authority: nil, fragment: nil, host: nil, path: "/foo/bar",
+           port: nil, query: nil, scheme: nil, userinfo: nil}
+
+      iex> URI.parse("foo/bar")
+      %URI{authority: nil, fragment: nil, host: nil, path: "foo/bar",
+           port: nil, query: nil, scheme: nil, userinfo: nil}
+
  """
  def parse(%URI{} = uri), do: uri

  def parse(s) when is_binary(s) do
    # From http://tools.ietf.org/html/rfc3986#appendix-B
-    regex = ~r/^(([^:\/?#]+):)?(\/\/([^\/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?/
+    regex = ~r/^(([a-z][a-z0-9\+\-\.]*):)?(\/\/([^\/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?/i
    parts = nillify(Regex.run(regex, s))

    destructure [_, _, scheme, _, authority, path, _, query, _, fragment], parts
@@ -309,7 +328,7 @@ defmodule URI do

    scheme = normalize_scheme(scheme)

-    if nil?(port) and not nil?(scheme) do
+    if is_nil(port) and not is_nil(scheme) do
      port = default_port(scheme)
    end

@@ -349,12 +368,20 @@ defimpl String.Chars, for: URI do
      if uri.port == port, do: uri = %{uri | port: nil}
    end

+    # Based on http://tools.ietf.org/html/rfc3986#section-5.3
+
+    if uri.host do
+      authority = uri.host
+      if uri.userinfo, do: authority = uri.userinfo <> "@" <> authority
+      if uri.port, do: authority = authority <> ":" <> Integer.to_string(uri.port)
+    else
+      authority = uri.authority
+    end
+
    result = ""

-    if uri.scheme,   do: result = result <> uri.scheme <> "://"
-    if uri.userinfo, do: result = result <> uri.userinfo <> "@"
-    if uri.host,     do: result = result <> uri.host
-    if uri.port,     do: result = result <> ":" <> Integer.to_string(uri.port)
+    if uri.scheme,   do: result = result <> uri.scheme <> ":"
+    if authority,    do: result = result <> "//" <> authority
    if uri.path,     do: result = result <> uri.path
    if uri.query,    do: result = result <> "?" <> uri.query
    if uri.fragment, do: result = result <> "#" <> uri.fragment
@@ -51,6 +51,19 @@ defmodule Version do

      "~> 2.0.0"

+  `~>` will never include pre-release versions of its upper bound.
+  It can also be used to set an upper bound on only the major
+  version part. See the table below for `~>` requirements and
+  their corresponding translation.
+
+  `~>`           | Translation
+  :------------- | :---------------------
+  `~> 2.0.0`     | `>= 2.0.0 and < 2.1.0`
+  `~> 2.1.2`     | `>= 2.1.2 and < 2.2.0`
+  `~> 2.1.3-dev` | `>= 2.1.3-dev and < 2.2.0`
+  `~> 2.0`       | `>= 2.0.0 and < 3.0.0`
+  `~> 2.1`       | `>= 2.1.0 and < 3.0.0`
+
  """

  import Kernel, except: [match?: 2]
@@ -61,7 +74,7 @@ defmodule Version do
  @type major       :: String.t | non_neg_integer
  @type minor       :: non_neg_integer | nil
  @type patch       :: non_neg_integer | nil
-  @type pre         :: [String.t]
+  @type pre         :: [String.t | non_neg_integer]
  @type build       :: String.t | nil
  @type matchable   :: {major :: major,
                        minor :: minor,
@@ -324,7 +337,7 @@ defmodule Version do
        patch = nillify(patch)
        pre   = nillify(pre)

-        if nil?(minor) or (nil?(patch) and not approximate?) do
+        if is_nil(minor) or (is_nil(patch) and not approximate?) do
          :error
        else
          major = String.to_integer(major)
@@ -506,10 +519,22 @@ end

 defimpl String.Chars, for: Version do
  def to_string(version) do
-    pre = unless Enum.empty?(pre = version.pre), do: "-#{pre}"
+    pre = pre(version.pre)
    build = if build = version.build, do: "+#{build}"
    "#{version.major}.#{version.minor}.#{version.patch}#{pre}#{build}"
  end
+
+  defp pre([]) do
+    ""
+  end
+
+  defp pre(pre) do
+    "-" <>
+      Enum.map_join(pre, ".", fn
+        int when is_integer(int) -> Integer.to_string(int)
+        string when is_binary(string) -> string
+      end)
+  end
 end

 defimpl Inspect, for: Version do
@@ -29,9 +29,12 @@ start(_Type, _Args) ->
    end,

  ok = io:setopts(standard_io, Opts),
-  %% Must use undocument {unicode, true} to set unicode on standard_error, more
-  %% info: http://erlang.org/pipermail/erlang-bugs/2014-April/004310.html
-  ok = io:setopts(standard_error, [{unicode,true}]),
+
+  ok = case io:setopts(standard_error, [{encoding,utf8}]) of
+    ok         -> ok;
+    {error, _} -> io:setopts(standard_error, [{unicode,true}]) %% R17.3 and earlier
+  end,
+
  case file:native_name_encoding() of
    latin1 ->
      io:format(standard_error,
@@ -42,10 +45,29 @@ start(_Type, _Args) ->
      ok
  end,

-  elixir_sup:start_link().
+  URIs = [{<<"ftp">>, 21},
+          {<<"sftp">>, 22},
+          {<<"tftp">>, 69},
+          {<<"http">>, 80},
+          {<<"https">>, 443},
+          {<<"ldap">>, 389}],
+  URIConfig = [{{uri, Scheme}, Port} || {Scheme, Port} <- URIs],
+  CompilerOpts = [{docs,true},{debug_info,true},{warnings_as_errors,false}],
+  Config = [{at_exit, []},
+            {compiler_options, orddict:from_list(CompilerOpts)}
+            | URIConfig],
+  Tab = elixir_config:new(Config),
+  case elixir_sup:start_link() of
+    {ok, Sup} ->
+      {ok, Sup, Tab};
+    {error, _Reason} = Error ->
+      elixir_config:delete(Tab),
+      Error
+  end.
+
+stop(Tab) ->
+  elixir_config:delete(Tab).

-stop(_S) ->
-  ok.

 config_change(_Changed, _New, _Remove) ->
  ok.
@@ -54,12 +76,17 @@ config_change(_Changed, _New, _Remove) ->

 start_cli() ->
  {ok, _} = application:ensure_all_started(?MODULE),
+
  %% We start the Logger so tools that depend on Elixir
  %% always have the Logger directly accessible. However
  %% Logger is not a dependency of the Elixir application,
  %% which means releases that want to use Logger must
  %% always list it as part of its applications.
-  _ = application:start(logger),
+  _ = case code:ensure_loaded('Elixir.Logger') of
+    {module, _} -> application:start(logger);
+    {error, _}  -> ok
+  end,
+
  'Elixir.Kernel.CLI':main(init:get_plain_arguments()).

 %% EVAL HOOKS
@@ -41,28 +41,29 @@
 %% Used in tokenization and interpolation

 %% Numbers
-define(is_hex(S), ?is_digit(S) orelse (S >= $A andalso S =< $F) orelse (S >= $a andalso S =< $f)).
-define(is_bin(S), S >= $0 andalso S =< $1).
-define(is_octal(S), S >= $0 andalso S =< $7).
-define(is_leading_octal(S), S >= $0 andalso S =< $3).
+-define(is_hex(S), (?is_digit(S) orelse (S >= $A andalso S =< $F) orelse (S >= $a andalso S =< $f))).
+-define(is_bin(S), (S >= $0 andalso S =< $1)).
+-define(is_octal(S), (S >= $0 andalso S =< $7)).
+-define(is_leading_octal(S), (S >= $0 andalso S =< $3)).

 %% Digits and letters
-define(is_digit(S), S >= $0 andalso S =< $9).
-define(is_upcase(S), S >= $A andalso S =< $Z).
-define(is_downcase(S), S >= $a andalso S =< $z).
+-define(is_digit(S), (S >= $0 andalso S =< $9)).
+-define(is_upcase(S), (S >= $A andalso S =< $Z)).
+-define(is_downcase(S), (S >= $a andalso S =< $z)).

 %% Atoms
-define(is_atom_start(S), ?is_quote(S) orelse ?is_upcase(S) orelse ?is_downcase(S) orelse (S == $_)).
-define(is_atom(S), ?is_identifier(S) orelse (S == $@)).
+-define(is_atom_start(S), (?is_quote(S) orelse ?is_upcase(S) orelse ?is_downcase(S) orelse (S == $_))).
+-define(is_atom(S), (?is_identifier(S) orelse (S == $@))).

-define(is_identifier(S), ?is_digit(S) orelse ?is_upcase(S) orelse ?is_downcase(S) orelse (S == $_)).
-define(is_sigil(S), (S == $/) orelse (S == $<) orelse (S == $") orelse (S == $') orelse
-                     (S == $[) orelse (S == $() orelse (S == ${) orelse (S == $|)).
+-define(is_identifier(S), (?is_digit(S) orelse ?is_upcase(S) orelse ?is_downcase(S) orelse (S == $_))).
+-define(is_sigil(S), ((S == $/) orelse (S == $<) orelse (S == $") orelse (S == $') orelse
+                      (S == $[) orelse (S == $() orelse (S == ${) orelse (S == $|))).

 %% Quotes
-define(is_quote(S), S == $" orelse S == $').
+-define(is_quote(S), (S == $" orelse S == $')).

 %% Spaces
-define(is_horizontal_space(S), (S == $\s) orelse (S == $\t)).
-define(is_vertical_space(S), (S == $\r) orelse (S == $\n)).
-define(is_space(S), ?is_horizontal_space(S) orelse ?is_vertical_space(S)).
+-define(is_horizontal_space(S), ((S == $\s) orelse (S == $\t))).
+-define(is_vertical_space(S), ((S == $\r) orelse (S == $\n))).
+-define(is_space(S), (?is_horizontal_space(S) orelse ?is_vertical_space(S))).
+-define(is_invalid_space(S), (S == 16#A0)).
@@ -36,7 +36,7 @@ expand_bitstr(Fun, [H|T], Acc, E) ->
 %% Expand bit info

 expand_bit_info(Meta, Info, E) ->
-  expand_bit_info(Meta, unpack_bit_info(Meta, Info, E), default, [], E).
+  expand_bit_info(Meta, unpack_bit_info(Info, []), default, [], E).

 expand_bit_info(Meta, [{size, _, [_]=Args}|T], Size, Types, E) ->
  case Size of
@@ -111,18 +111,9 @@ handle_unknown_bit_info(Meta, Expr, T, Size, Types, E) ->
      elixir_errors:compile_error(Meta, ?m(E, file),
        "unknown bitstring specifier ~ts", ['Elixir.Macro':to_string(Expr)]);
    Info ->
-      expand_bit_info(Meta, unpack_bit_info(Meta, Info, E) ++ T, Size, Types, E)
+      expand_bit_info(Meta, unpack_bit_info(Info, []) ++ T, Size, Types, E)
  end.

-%% We can remove unpack_bit_info/3 once deprecated.
-unpack_bit_info(Meta, [H|T], E) ->
-  elixir_errors:warn(?line(Meta), ?m(E, file), "passing a list of bitstring modifiers is deprecated, "
-    "please separate them with - instead"),
-  Dashed = lists:foldl(fun(I, Acc) -> {'-', Meta, [Acc, I]} end, H, T),
-  unpack_bit_info(Dashed, []);
-unpack_bit_info(_Meta, Expr, _E) ->
-  unpack_bit_info(Expr, []).
-
 unpack_bit_info({'-', _, [H, T]}, Acc) ->
  unpack_bit_info(H, unpack_bit_info(T, Acc));
 unpack_bit_info({'*', _, [{'_', _, Atom}, Unit]}, Acc) when is_atom(Atom) and is_integer(Unit) ->
@@ -44,7 +44,7 @@ define({Line,E}, Kind, Call, Expr) ->
 unless_loaded(Fun, Args, Callback) ->
  case code:is_loaded(?kernel) of
    {_, _} -> apply(?kernel, Fun, Args);
-    false   -> Callback()
+    false  -> Callback()
  end.

 env() ->
@@ -6,14 +6,11 @@

 -define(timeout, 30000).
 -record(elixir_code_server, {
-  compilation_status=[],
-  argv=[],
  loaded=[],
-  at_exit=[],
-  pool={[],0},
  paths={[],[]},
-  compiler_options=[{docs,true},{debug_info,true},{warnings_as_errors,false}],
-  erl_compiler_options=nil
+  mod_pool={[],0},
+  mod_ets=dict:new(),
+  compilation_status=[]
 }).

 call(Args) ->
@@ -29,14 +26,21 @@ start_link() ->

 init(ok) ->
  %% We attempt to load those modules here so throughout
-  %% the codebase we can use a code:is_loaded/1 check on
-  %% bootstrap instead of using the more expensive
-  %% code:ensure_loaded/1 multiple times.
+  %% the codebase we can avoid code:is_loaded/1 checks.
  _ = code:ensure_loaded('Elixir.Macro.Env'),
-  _ = code:ensure_loaded('Elixir.Module.LocalsTracker'),
-  _ = code:ensure_loaded('Elixir.Kernel.LexicalTracker'),
+
+  %% The table where we store module definitions
+  _ = ets:new(elixir_modules, [set, protected, named_table, {read_concurrency, true}]),
+
  {ok, #elixir_code_server{}}.

+handle_call({defmodule, Pid, Tuple}, _From, Config) ->
+  {Ref, New} = defmodule(Pid, Tuple, Config),
+  {reply, Ref, New};
+
+handle_call({undefmodule, Ref}, _From, Config) ->
+  {reply, ok, undefmodule(Ref, Config)};
+
 handle_call({acquire, Path}, From, Config) ->
  Current = Config#elixir_code_server.loaded,
  case orddict:find(Path, Current) of
@@ -53,18 +57,6 @@ handle_call({acquire, Path}, From, Config) ->
 handle_call(loaded, _From, Config) ->
  {reply, [F || {F, true} <- Config#elixir_code_server.loaded], Config};

-handle_call(at_exit, _From, Config) ->
-  {reply, Config#elixir_code_server.at_exit, Config};
-
-handle_call(flush_at_exit, _From, Config) ->
-  {reply, Config#elixir_code_server.at_exit, Config#elixir_code_server{at_exit=[]}};
-
-handle_call(argv, _From, Config) ->
-  {reply, Config#elixir_code_server.argv, Config};
-
-handle_call(compiler_options, _From, Config) ->
-  {reply, Config#elixir_code_server.compiler_options, Config};
-
 handle_call({compilation_status, CompilerPid}, _From, Config) ->
  CompilationStatusList    = Config#elixir_code_server.compilation_status,
  CompilationStatusListNew = orddict:erase(CompilerPid, CompilationStatusList),
@@ -73,20 +65,11 @@ handle_call({compilation_status, CompilerPid}, _From, Config) ->
   Config#elixir_code_server{compilation_status=CompilationStatusListNew}};

 handle_call(retrieve_module_name, _From, Config) ->
-  case Config#elixir_code_server.pool of
+  case Config#elixir_code_server.mod_pool of
    {[H|T], Counter} ->
-      {reply, module_tuple(H), Config#elixir_code_server{pool={T,Counter}}};
+      {reply, module_tuple(H), Config#elixir_code_server{mod_pool={T,Counter}}};
    {[], Counter} ->
-      {reply, module_tuple(Counter), Config#elixir_code_server{pool={[],Counter+1}}}
-  end;
-
-handle_call(erl_compiler_options, _From, Config) ->
-  case Config#elixir_code_server.erl_compiler_options of
-    nil ->
-      Opts = erl_compiler_options(),
-      {reply, Opts, Config#elixir_code_server{erl_compiler_options=Opts}};
-    Opts ->
-      {reply, Opts, Config}
+      {reply, module_tuple(Counter), Config#elixir_code_server{mod_pool={[],Counter+1}}}
  end;

 handle_call(paths, _From, Config) ->
@@ -95,20 +78,11 @@ handle_call(paths, _From, Config) ->
 handle_call(Request, _From, Config) ->
  {stop, {badcall, Request}, Config}.

-handle_cast({at_exit, AtExit}, Config) ->
-  {noreply, Config#elixir_code_server{at_exit=[AtExit|Config#elixir_code_server.at_exit]}};
-
-handle_cast({argv, Argv}, Config) ->
-  {noreply, Config#elixir_code_server{argv=Argv}};
-
-handle_cast({compiler_options, Options}, Config) ->
-  Final = orddict:merge(fun(_,_,V) -> V end, Config#elixir_code_server.compiler_options, Options),
-  {noreply, Config#elixir_code_server{compiler_options=Final}};
-
 handle_cast({register_warning, CompilerPid}, Config) ->
  CompilationStatusCurrent = Config#elixir_code_server.compilation_status,
  CompilationStatusNew     = orddict:store(CompilerPid, error, CompilationStatusCurrent),
-  case orddict:find(warnings_as_errors, Config#elixir_code_server.compiler_options) of
+  CompilerOptions          = elixir_config:get(compiler_options),
+  case orddict:find(warnings_as_errors, CompilerOptions) of
    {ok, true} -> {noreply, Config#elixir_code_server{compilation_status=CompilationStatusNew}};
    _ -> {noreply, Config}
  end;
@@ -137,8 +111,8 @@ handle_cast({unload_files, Files}, Config) ->
  Unloaded = lists:foldl(fun(File, Acc) -> orddict:erase(File, Acc) end, Current, Files),
  {noreply, Config#elixir_code_server{loaded=Unloaded}};

-handle_cast({return_module_name, H}, #elixir_code_server{pool={T,Counter}} = Config) ->
-  {noreply, Config#elixir_code_server{pool={[H|T],Counter}}};
+handle_cast({return_module_name, H}, #elixir_code_server{mod_pool={T,Counter}} = Config) ->
+  {noreply, Config#elixir_code_server{mod_pool={[H|T],Counter}}};

 handle_cast({paths, PA, PZ}, #elixir_code_server{} = Config) ->
  {noreply, Config#elixir_code_server{paths={PA,PZ}}};
@@ -146,7 +120,10 @@ handle_cast({paths, PA, PZ}, #elixir_code_server{} = Config) ->
 handle_cast(Request, Config) ->
  {stop, {badcast, Request}, Config}.

-handle_info(_Request, Config) ->
+handle_info({'DOWN', Ref, process, _Pid, _Reason}, Config) ->
+  {noreply, undefmodule(Ref, Config)};
+
+handle_info(_Msg, Config) ->
  {noreply, Config}.

 terminate(_Reason, _Config) ->
@@ -158,22 +135,17 @@ code_change(_Old, Config, _Extra) ->
 module_tuple(I) ->
  {list_to_atom("elixir_compiler_" ++ integer_to_list(I)), I}.

-erl_compiler_options() ->
-  Key = "ERL_COMPILER_OPTIONS",
-  case os:getenv(Key) of
-    false -> [];
-    Str when is_list(Str) ->
-      case erl_scan:string(Str) of
-        {ok,Tokens,_} ->
-          case erl_parse:parse_term(Tokens ++ [{dot, 1}]) of
-            {ok,List} when is_list(List) -> List;
-            {ok,Term} -> [Term];
-            {error,_Reason} ->
-              io:format("Ignoring bad term in ~ts\n", [Key]),
-              []
-          end;
-        {error, {_,_,_Reason}, _} ->
-          io:format("Ignoring bad term in ~ts\n", [Key]),
-          []
-      end
+defmodule(Pid, Tuple, #elixir_code_server{mod_ets=ModEts} = Config) ->
+  ets:insert(elixir_modules, Tuple),
+  Ref = erlang:monitor(process, Pid),
+  Mod = erlang:element(1, Tuple),
+  {Ref, Config#elixir_code_server{mod_ets=dict:store(Ref, Mod, ModEts)}}.
+
+undefmodule(Ref, #elixir_code_server{mod_ets=ModEts} = Config) ->
+  case dict:find(Ref, ModEts) of
+    {ok, Mod} ->
+      ets:delete(elixir_modules, Mod),
+      Config#elixir_code_server{mod_ets=dict:erase(Ref, ModEts)};
+    error ->
+      Config
  end.
@@ -1,12 +1,12 @@
 -module(elixir_compiler).
-export([get_opt/1, string/2, quoted/2, file/1, file_to_path/2]).
+-export([get_opt/1, string/2, quoted/2, file/1, file/2, file_to_path/2]).
 -export([core/0, module/4, eval_forms/3]).
 -include("elixir.hrl").

 %% Public API

 get_opt(Key) ->
-  Dict = elixir_code_server:call(compiler_options),
+  Dict = elixir_config:get(compiler_options),
  case lists:keyfind(Key, 1, Dict) of
    false -> false;
    {Key, Value} -> Value
@@ -15,15 +15,19 @@ get_opt(Key) ->
 %% Compilation entry points.

 string(Contents, File) when is_list(Contents), is_binary(File) ->
+  string(Contents, File, nil).
+string(Contents, File, Dest) ->
  Forms = elixir:'string_to_quoted!'(Contents, 1, File, []),
-  quoted(Forms, File).
+  quoted(Forms, File, Dest).

 quoted(Forms, File) when is_binary(File) ->
+  quoted(Forms, File, nil).
+quoted(Forms, File, Dest) ->
  Previous = get(elixir_compiled),

  try
    put(elixir_compiled, []),
-    elixir_lexical:run(File, fun
+    elixir_lexical:run(File, Dest, fun
      (Pid) ->
        Env = elixir:env_for_eval([{line,1},{file,File}]),
        eval_forms(Forms, [], Env#{lexical_tracker := Pid})
@@ -34,14 +38,20 @@ quoted(Forms, File) when is_binary(File) ->
  end.

 file(Relative) when is_binary(Relative) ->
+  file(Relative, nil).
+file(Relative, Dest) ->
  File = filename:absname(Relative),
  {ok, Bin} = file:read_file(File),
-  string(elixir_utils:characters_to_list(Bin), File).
+  string(elixir_utils:characters_to_list(Bin), File, case Dest of
+    nil -> Dest;
+    _   -> filename:absname(Dest)
+  end).

-file_to_path(File, Path) when is_binary(File), is_binary(Path) ->
-  Lists = file(File),
-  _ = [binary_to_path(X, Path) || X <- Lists],
-  Lists.
+file_to_path(File, Dest) when is_binary(File), is_binary(Dest) ->
+  Comp = file(File, Dest),
+  Abs  = filename:absname(Dest),
+  _ = [binary_to_path(X, Abs) || X <- Comp],
+  Comp.

 %% Evaluation

@@ -68,9 +78,9 @@ code_loading_compilation(Forms, Vars, #{line := Line} = E) ->

  %% Pass {native, false} to speed up bootstrap
  %% process when native is set to true
-  AllOpts   = elixir_code_server:call(erl_compiler_options),
+  AllOpts   = options(),
  FinalOpts = AllOpts -- [native, warn_missing_spec],
-  module(Form, ?m(E, file), FinalOpts, true, fun(_, Binary) ->
+  inner_module(Form, FinalOpts, true, E, fun(_, Binary) ->
    %% If we have labeled locals, anonymous functions
    %% were created and therefore we cannot ditch the
    %% module
@@ -82,6 +92,36 @@ code_loading_compilation(Forms, Vars, #{line := Line} = E) ->
    dispatch_loaded(Module, Fun, Args, Purgeable, I, EE)
  end).

+options() ->
+  case elixir_config:get(erl_compiler_options) of
+    nil ->
+      elixir_config:update(erl_compiler_options, fun options/1);
+    Opts ->
+      Opts
+  end.
+
+options(nil) ->
+  Key = "ERL_COMPILER_OPTIONS",
+  case os:getenv(Key) of
+    false -> [];
+    Str when is_list(Str) ->
+      case erl_scan:string(Str) of
+        {ok,Tokens,_} ->
+          case erl_parse:parse_term(Tokens ++ [{dot, 1}]) of
+            {ok,List} when is_list(List) -> List;
+            {ok,Term} -> [Term];
+            {error,_Reason} ->
+              io:format("Ignoring bad term in ~ts\n", [Key]),
+              []
+          end;
+        {error, {_,_,_Reason}, _} ->
+          io:format("Ignoring bad term in ~ts\n", [Key]),
+          []
+      end
+  end;
+options(Opts) ->
+    Opts.
+
 dispatch_loaded(Module, Fun, Args, Purgeable, I, E) ->
  Res = Module:Fun(Args),
  code:delete(Module),
@@ -128,29 +168,38 @@ allows_fast_compilation(_) -> false.
 %% Compile the module by forms based on the scope information
 %% executes the callback in case of success. This automatically
 %% handles errors and warnings. Used by this module and elixir_module.
-module(Forms, File, Opts, Callback) ->
+module(Forms, Opts, E, Callback) ->
  Final =
    case (get_opt(debug_info) == true) orelse
         lists:member(debug_info, Opts) of
-      true  -> [debug_info] ++ elixir_code_server:call(erl_compiler_options);
-      false -> elixir_code_server:call(erl_compiler_options)
+      true  -> [debug_info] ++ options();
+      false -> options()
    end,
-  module(Forms, File, Final, false, Callback).
+  inner_module(Forms, Final, false, E, Callback).

-module(Forms, File, Options, Bootstrap, Callback) when
-    is_binary(File), is_list(Forms), is_list(Options), is_boolean(Bootstrap), is_function(Callback) ->
-  Listname = elixir_utils:characters_to_list(File),
+inner_module(Forms, Options, Bootstrap, #{file := File} = E, Callback) when
+    is_list(Forms), is_list(Options), is_boolean(Bootstrap), is_function(Callback) ->
+  Source = elixir_utils:characters_to_list(File),

-  case compile:noenv_forms([no_auto_import()|Forms], [return,{source,Listname}|Options]) of
-    {ok, ModuleName, Binary, Warnings} ->
+  case compile:noenv_forms([no_auto_import()|Forms], [return,{source,Source}|Options]) of
+    {ok, Module, Binary, Warnings} ->
      format_warnings(Bootstrap, Warnings),
-      {module, ModuleName} = code:load_binary(ModuleName, Listname, Binary),
-      Callback(ModuleName, Binary);
+      {module, Module} = code:load_binary(Module, beam_location(E), Binary),
+      Callback(Module, Binary);
    {error, Errors, Warnings} ->
      format_warnings(Bootstrap, Warnings),
      format_errors(Errors)
  end.

+beam_location(#{module := nil}) -> in_memory;
+beam_location(#{lexical_tracker := Pid, module := Module}) ->
+  case elixir_lexical:dest(Pid) of
+    nil  -> in_memory;
+    Dest ->
+      filename:join(elixir_utils:characters_to_list(Dest),
+                    atom_to_list(Module) ++ ".beam")
+  end.
+
 no_auto_import() ->
  {attribute, 0, compile, no_auto_import}.

@@ -158,7 +207,10 @@ no_auto_import() ->

 core() ->
  {ok, _} = application:ensure_all_started(elixir),
-  elixir_code_server:cast({compiler_options, [{docs,false},{internal,true}]}),
+  New = orddict:from_list([{docs,false},{internal,true}]),
+  Merge = fun(_, _, Value) -> Value end,
+  Update = fun(Old) -> orddict:merge(Merge, Old, New) end,
+  _ = elixir_config:update(compiler_options, Update),
  [core_file(File) || File <- core_main()].

 core_file(File) ->
@@ -0,0 +1,65 @@
+-module(elixir_config).
+-compile({no_auto_import, [get/1]}).
+-export([new/1, delete/1, put/2, get/1, update/2, get_and_put/2]).
+-export([start_link/0, init/1, handle_call/3, handle_cast/2,
+  handle_info/2, code_change/3, terminate/2]).
+-behaviour(gen_server).
+
+%% public api
+
+new(Opts) ->
+  Tab = ets:new(?MODULE, [named_table, public, {read_concurrency, true}]),
+  true = ets:insert_new(?MODULE, Opts),
+  Tab.
+
+delete(?MODULE) ->
+  ets:delete(?MODULE).
+
+put(Key, Value) ->
+  gen_server:call(?MODULE, {put, Key, Value}).
+
+get(Key) ->
+  case ets:lookup(?MODULE, Key) of
+    [{_, Value}] -> Value;
+    []          -> nil
+  end.
+
+update(Key, Fun) ->
+  gen_server:call(?MODULE, {update, Key, Fun}).
+
+get_and_put(Key, Value) ->
+  gen_server:call(?MODULE, {get_and_put, Key, Value}).
+
+start_link() ->
+  gen_server:start_link({local, ?MODULE}, ?MODULE, ?MODULE, []).
+
+%% gen_server api
+
+init(Tab) ->
+  %% Ets table must be writable
+  public = ets:info(Tab, protection),
+  {ok, Tab}.
+
+handle_call({put, Key, Value}, _From, Tab) ->
+  ets:insert(Tab, {Key, Value}),
+  {reply, ok, Tab};
+handle_call({update, Key, Fun}, _From, Tab) ->
+  Value = Fun(get(Key)),
+  ets:insert(Tab, {Key, Value}),
+  {reply, Value, Tab};
+handle_call({get_and_put, Key, Value}, _From, Tab) ->
+  OldValue = get(Key),
+  ets:insert(Tab, {Key, Value}),
+  {reply, OldValue, Tab}.
+
+handle_cast(Cast, Tab) ->
+  {stop, {bad_cast, Cast}, Tab}.
+
+handle_info(_Msg, Tab) ->
+  {noreply, Tab}.
+
+code_change(_OldVsn, Tab, _Extra) ->
+  {ok, Tab}.
+
+terminate(_Reason, _Tab) ->
+  ok.
@@ -3,8 +3,8 @@
  handle_info/2, terminate/2, code_change/3, next/0]).
 -behaviour(gen_server).

-define(timeout, 1000).     %% 1 second
-define(limit, 4294967296). %% 2^32
+-define(timeout, 30000).    %% 30 seconds
+-define(limit, 4294967295). %% 2^32 - 1

 next() ->
  gen_server:call(?MODULE, next, ?timeout).
@@ -1,49 +1,35 @@
 % Holds the logic responsible for function definitions (def(p) and defmacro(p)).
 -module(elixir_def).
-export([table/1, clauses_table/1, setup/1,
-  cleanup/1, reset_last/1, lookup_definition/2,
+-export([setup/1, reset_last/1, lookup_definition/2,
  delete_definition/2, store_definition/6, unwrap_definitions/2,
-  store_each/8, format_error/1]).
+  store_each/7, format_error/1]).
 -include("elixir.hrl").

-define(attr, '__def_table').
-define(clauses_attr, '__clauses_table').
+-define(last_def, {elixir, last_def}).
+-define(attr, {elixir, def_table}).
+-define(clauses_attr, {elixir, clauses_table}).

 %% Table management functions. Called internally.

-table(Module) ->
-  ets:lookup_element(Module, ?attr, 2).
-
-clauses_table(Module) ->
-  ets:lookup_element(Module, ?clauses_attr, 2).
-
 setup(Module) ->
-  ets:insert(Module, {?attr, ets:new(Module, [set, public])}),
-  ets:insert(Module, {?clauses_attr, ets:new(Module, [bag, public])}),
  reset_last(Module),
  ok.

-cleanup(Module) ->
-  ets:delete(table(Module)),
-  ets:delete(clauses_table(Module)).
-
-%% Reset the last item. Useful when evaling code.
 reset_last(Module) ->
-  ets:insert(table(Module), {last, []}).
+  ets:insert(elixir_module:data_table(Module), {?last_def, []}).

-%% Looks up a definition from the database.
 lookup_definition(Module, Tuple) ->
-  case ets:lookup(table(Module), Tuple) of
+  case ets:lookup(elixir_module:defs_table(Module), Tuple) of
    [Result] ->
-      CTable = clauses_table(Module),
+      CTable = elixir_module:clas_table(Module),
      {Result, [Clause || {_, Clause} <- ets:lookup(CTable, Tuple)]};
    _ ->
      false
  end.

 delete_definition(Module, Tuple) ->
-  ets:delete(table(Module), Tuple),
-  ets:delete(clauses_table(Module), Tuple).
+  ets:delete(elixir_module:defs_table(Module), Tuple),
+  ets:delete(elixir_module:clas_table(Module), Tuple).

 % Invoked by the wrap definition with the function abstract tree.
 % Each function is then added to the function table.
@@ -82,6 +68,7 @@ store_definition(Line, Kind, CheckClauses, Call, Body, Pos) ->
  LinifyBody   = elixir_quote:linify(Line, Key, Body),

  assert_no_aliases_name(Line, Name, Args, E),
+  assert_valid_name(Line, Kind, Name, Args, E),
  store_definition(Line, Kind, DoCheckClauses, Name,
                   LinifyArgs, LinifyGuards, LinifyBody, Location, E).

@@ -97,16 +84,12 @@ store_definition(Line, Kind, CheckClauses, Name, Args, Guards, Body, KeepLocatio
  DefaultsLength = length(Defaults),
  elixir_locals:record_defaults(Tuple, Kind, Module, DefaultsLength),

-  File   = ?m(E, file),
-  Table  = table(Module),
-  CTable = clauses_table(Module),
-
+  File = ?m(E, file),
  compile_super(Module, Super, E),
-  check_previous_defaults(Table, Line, Name, Arity, Kind, DefaultsLength, E),
+  check_previous_defaults(Line, Module, Name, Arity, Kind, DefaultsLength, E),

-  store_each(CheckClauses, Kind, File, Location,
-    Table, CTable, DefaultsLength, Function),
-  [store_each(false, Kind, File, Location, Table, CTable, 0,
+  store_each(CheckClauses, Kind, File, Location, Module, DefaultsLength, Function),
+  [store_each(false, Kind, File, Location, Module, 0,
    default_function_for(Kind, Name, Default)) || Default <- Defaults],

  make_struct_available(Kind, Module, Name, Args),
@@ -165,7 +148,7 @@ normalize_location(File) ->
 %% Compile super

 compile_super(Module, true, #{function := Function}) ->
-  elixir_def_overridable:store(Module, Function, true);
+  elixir_def_overridable:super(Module, Function);
 compile_super(_Module, _, _E) -> ok.

 %% Translate the given call and expression given
@@ -175,7 +158,7 @@ translate_definition(Kind, Line, Module, Name, Args, Guards, Body, E) when is_in
  Arity = length(Args),

  {EArgs, EGuards, EBody, _} = elixir_exp_clauses:def(fun elixir_def_defaults:expand/2,
-                                   Args, Guards, expr_from_body(Line, Body), E),
+                                Args, Guards, expr_from_body(Line, Body), E),

  Body == nil andalso check_args_for_bodyless_clause(Line, EArgs, E),

@@ -228,9 +211,8 @@ is_macro(_)         -> false.
 % It returns a list of all functions to be exported, plus the macros,
 % and the body of all functions.
 unwrap_definitions(File, Module) ->
-  Table  = table(Module),
-  CTable = clauses_table(Module),
-  ets:delete(Table, last),
+  Table  = elixir_module:defs_table(Module),
+  CTable = elixir_module:clas_table(Module),

  {All, Private} = unwrap_definition(ets:tab2list(Table), File, Module, CTable, [], []),
  Unreachable = elixir_locals:warn_unused_local(File, Module, Private),
@@ -326,26 +308,33 @@ warn_bodyless_function(Line, File, _Module, Kind, Tuple) ->
 %% This function also checks and emit warnings in case
 %% the kind, of the visibility of the function changes.

-store_each(Check, Kind, File, Location, Table, CTable, Defaults, {function, Line, Name, Arity, Clauses}) ->
-  Tuple = {Name, Arity},
+store_each(Check, Kind, File, Location, Module, Defaults, {function, Line, Name, Arity, Clauses}) ->
+  Data = elixir_module:data_table(Module),
+  Defs = elixir_module:defs_table(Module),
+  Clas = elixir_module:clas_table(Module),
+
+  Tuple   = {Name, Arity},
  HasBody = Clauses =/= [],
-  case ets:lookup(Table, Tuple) of
-    [{Tuple, StoredKind, StoredLine, StoredFile, StoredCheck, StoredLocation, {StoredDefaults, LastHasBody, LastDefaults}}] ->
+
+  case ets:lookup(Defs, Tuple) of
+    [{Tuple, StoredKind, StoredLine, StoredFile, StoredCheck,
+        StoredLocation, {StoredDefaults, LastHasBody, LastDefaults}}] ->
      FinalLine = StoredLine,
      FinalLocation = StoredLocation,
      FinalDefaults = {max(Defaults, StoredDefaults), HasBody, Defaults},
      check_valid_kind(Line, File, Name, Arity, Kind, StoredKind),
      (Check and StoredCheck) andalso
-        check_valid_clause(Line, File, Name, Arity, Kind, Table, StoredLine, StoredFile),
+        check_valid_clause(Line, File, Name, Arity, Kind, Data, StoredLine, StoredFile),
      check_valid_defaults(Line, File, Name, Arity, Kind, Defaults, LastDefaults, LastHasBody);
    [] ->
      FinalLine = Line,
      FinalLocation = Location,
      FinalDefaults = {Defaults, HasBody, Defaults}
  end,
-  Check andalso ets:insert(Table, {last, {Name, Arity}}),
-  ets:insert(CTable, [{Tuple, Clause} || Clause <- Clauses ]),
-  ets:insert(Table, {Tuple, Kind, FinalLine, File, Check, FinalLocation, FinalDefaults}).
+
+  Check andalso ets:insert(Data, {?last_def, {Name, Arity}}),
+  ets:insert(Clas, [{Tuple, Clause} || Clause <- Clauses]),
+  ets:insert(Defs, {Tuple, Kind, FinalLine, File, Check, FinalLocation, FinalDefaults}).

 %% Validations

@@ -354,8 +343,8 @@ check_valid_kind(Line, File, Name, Arity, Kind, StoredKind) ->
  elixir_errors:form_error([{line, Line}], File, ?MODULE,
    {changed_kind, {Name, Arity, StoredKind, Kind}}).

-check_valid_clause(Line, File, Name, Arity, Kind, Table, StoredLine, StoredFile) ->
-  case ets:lookup_element(Table, last, 2) of
+check_valid_clause(Line, File, Name, Arity, Kind, Data, StoredLine, StoredFile) ->
+  case ets:lookup_element(Data, ?last_def, 2) of
    {Name,Arity} -> [];
    [] -> [];
    _ ->
@@ -378,8 +367,8 @@ check_valid_defaults(Line, File, Name, Arity, Kind, _, _, _) ->
  elixir_errors:form_error([{line, Line}], File, ?MODULE,
    {clauses_with_defaults, {Kind, Name, Arity}}).

-check_previous_defaults(Table, Line, Name, Arity, Kind, Defaults, E) ->
-  Matches = ets:match(Table, {{Name, '$2'}, '$1', '_', '_', '_', '_', {'$3', '_', '_'}}),
+check_previous_defaults(Line, Module, Name, Arity, Kind, Defaults, E) ->
+  Matches = ets:match(elixir_module:defs_table(Module), {{Name, '$2'}, '$1', '_', '_', '_', '_', {'$3', '_', '_'}}),
  [ begin
      elixir_errors:form_error([{line, Line}], ?m(E, file), ?MODULE,
        {defs_with_defaults, Name, {Kind, Arity}, {K, A}})
@@ -404,8 +393,12 @@ invalid_arg(_) ->

 assert_no_aliases_name(Line, '__aliases__', [Atom], #{file := File}) when is_atom(Atom) ->
  elixir_errors:form_error([{line, Line}], File, ?MODULE, {no_alias, Atom});
+assert_no_aliases_name(_Line, _Aliases, _Args, _S) ->
+  ok.

-assert_no_aliases_name(_Meta, _Aliases, _Args, _S) ->
+assert_valid_name(Line, Kind, is_record, [_, _], #{file := File}) when Kind == defp; Kind == def ->
+  elixir_errors:form_error([{line, Line}], File, ?MODULE, {is_record, Kind});
+assert_valid_name(_Line, _Kind, _Name, _Args, _S) ->
  ok.

 %% Format errors
@@ -447,5 +440,9 @@ format_error({invalid_def, Kind, NameAndArgs}) ->
 format_error(invalid_args_for_bodyless_clause) ->
  "can use only variables and \\\\ as arguments of bodyless clause";

+format_error({is_record, Kind}) ->
+  io_lib:format("cannot define function named ~ts is_record/2 due to compability "
+                "issues with the Erlang compiler (it is a known bug)", [Kind]);
+
 format_error({missing_do, Kind}) ->
  io_lib:format("missing do keyword in ~ts", [Kind]).
@@ -4,10 +4,11 @@
 -include("elixir.hrl").

 expand(Args, E) ->
+  NoContext = E#{context := nil},
  lists:mapfoldl(fun
    ({'\\\\', Meta, [Left, Right]}, Acc) ->
      {ELeft, EL} = elixir_exp:expand(Left, Acc),
-      {ERight, _} = elixir_exp:expand(Right, Acc#{context := nil}),
+      {ERight, _} = elixir_exp:expand(Right, NoContext),
      {{'\\\\', Meta, [ELeft, ERight]}, EL};
    (Left, Acc) ->
      elixir_exp:expand(Left, Acc)
@@ -1,14 +1,18 @@
 % Holds the logic responsible for defining overridable functions and handling super.
 -module(elixir_def_overridable).
-export([store_pending/1, ensure_defined/4,
-  name/2, store/3, format_error/1]).
+-export([setup/1, overridable/1, overridable/2, name/2, super/2, store_pending/1,
+         ensure_defined/4, format_error/1]).
 -include("elixir.hrl").
+-define(attr, {elixir, overridable}).
+
+setup(Module) ->
+  overridable(Module, []).

 overridable(Module) ->
-  ets:lookup_element(elixir_module:data_table(Module), '__overridable', 2).
+  ets:lookup_element(elixir_module:data_table(Module), ?attr, 2).

 overridable(Module, Value) ->
-  ets:insert(elixir_module:data_table(Module), {'__overridable', Value}).
+  ets:insert(elixir_module:data_table(Module), {?attr, Value}).

 %% Check if an overridable function is defined.

@@ -43,19 +47,19 @@ store(Module, Function, GenerateName) ->
        false -> {Kind, Name}
      end,

-      case code:is_loaded('Elixir.Module.LocalsTracker') of
-        {_, _} ->
+      case elixir_compiler:get_opt(internal) of
+        false ->
          'Elixir.Module.LocalsTracker':reattach(Module, Kind, {Name, Arity}, Neighbours);
-        _ ->
+        true ->
          ok
      end,

      Def = {function, Line, FinalName, Arity, Clauses},
-      elixir_def:store_each(false, FinalKind, File, Location,
-        elixir_def:table(Module), elixir_def:clauses_table(Module), Defaults, Def)
+      elixir_def:store_each(false, FinalKind, File, Location, Module, Defaults, Def)
  end.

-%% Store pending declarations that were not manually made concrete.
+super(Module, Function) ->
+  store(Module, Function, true).

 store_pending(Module) ->
  _ = [store(Module, X, false) || {X, {_, _, _, false}} <- overridable(Module),
@@ -73,4 +77,4 @@ format_error({no_super, Module, {Name, Arity}}) ->
 format_fa({Name, Arity}) ->
  A = atom_to_binary(Name, utf8),
  B = integer_to_binary(Arity),
-  << A/binary, $/, B/binary >>.
+  <<A/binary, $/, B/binary>>.
@@ -9,20 +9,7 @@
  find_import/4, format_error/1]).
 -include("elixir.hrl").
 -import(ordsets, [is_element/2]).
-
-define(atom, 'Elixir.Atom').
-define(float, 'Elixir.Float').
-define(io, 'Elixir.IO').
-define(integer, 'Elixir.Integer').
 -define(kernel, 'Elixir.Kernel').
-define(list, 'Elixir.List').
-define(map, 'Elixir.Map').
-define(node, 'Elixir.Node').
-define(port, 'Elixir.Port').
-define(process, 'Elixir.Process').
-define(string, 'Elixir.String').
-define(system, 'Elixir.System').
-define(tuple, 'Elixir.Tuple').

 default_functions() ->
  [{?kernel, elixir_imported_functions()}].
@@ -31,17 +18,20 @@ default_macros() ->
 default_requires() ->
  ['Elixir.Kernel', 'Elixir.Kernel.Typespec'].

+%% This is used by elixir_quote. Note we don't record the
+%% import locally because at that point there is no
+%% ambiguity.
 find_import(Meta, Name, Arity, E) ->
  Tuple = {Name, Arity},

  case find_dispatch(Meta, Tuple, [], E) of
    {function, Receiver} ->
      elixir_lexical:record_import(Receiver, ?m(E, lexical_tracker)),
-      elixir_locals:record_import(Tuple, Receiver, ?m(E, module), ?m(E, function)),
+      %% elixir_locals:record_import(Tuple, Receiver, ?m(E, module), ?m(E, function)),
      Receiver;
    {macro, Receiver} ->
      elixir_lexical:record_import(Receiver, ?m(E, lexical_tracker)),
-      elixir_locals:record_import(Tuple, Receiver, ?m(E, module), ?m(E, function)),
+      %% elixir_locals:record_import(Tuple, Receiver, ?m(E, module), ?m(E, function)),
      Receiver;
    _ ->
      false
@@ -79,7 +69,7 @@ remote_function(Meta, Receiver, Name, Arity, E) ->
  check_deprecation(Meta, Receiver, Name, Arity, E),

  elixir_lexical:record_remote(Receiver, ?m(E, lexical_tracker)),
-  case inline(Receiver, Name, Arity) of
+  case elixir_rewrite:inline(Receiver, Name, Arity) of
    {AR, AN} -> {remote, AR, AN, Arity};
    false    -> {remote, Receiver, Name, Arity}
  end.
@@ -100,9 +90,9 @@ dispatch_import(Meta, Name, Args, E, Callback) ->
 dispatch_require(Meta, Receiver, Name, Args, E, Callback) when is_atom(Receiver) ->
  Arity = length(Args),

-  case rewrite(Receiver, Name, Args, Arity) of
-    {ok, AR, AN, AA} ->
-      Callback(AR, AN, AA);
+  case elixir_rewrite:inline(Receiver, Name, Arity) of
+    {AR, AN} ->
+      Callback(AR, AN, Args);
    false ->
      case expand_require(Meta, Receiver, {Name, Arity}, Args, E) of
        {ok, Receiver, Quoted} -> expand_quoted(Meta, Receiver, Name, Arity, Quoted, E);
@@ -148,11 +138,7 @@ do_expand_import(Meta, {Name, Arity} = Tuple, Args, Module, E, Result) ->
    {function, Receiver} ->
      elixir_lexical:record_import(Receiver, ?m(E, lexical_tracker)),
      elixir_locals:record_import(Tuple, Receiver, Module, ?m(E, function)),
-
-      case rewrite(Receiver, Name, Args, Arity) of
-        {ok, _, _, _} = Res -> Res;
-        false -> {ok, Receiver, Name, Args}
-      end;
+      {ok, Receiver, Name, Args};
    {macro, Receiver} ->
      check_deprecation(Meta, Receiver, Name, Arity, E),
      elixir_lexical:record_import(Receiver, ?m(E, lexical_tracker)),
@@ -164,8 +150,8 @@ do_expand_import(Meta, {Name, Arity} = Tuple, Args, Module, E, Result) ->
        error -> {ok, Receiver, Name, Args}
      end;
    false when Module == ?kernel ->
-      case rewrite(Module, Name, Args, Arity) of
-        {ok, _, _, _} = Res -> Res;
+      case elixir_rewrite:inline(Module, Name, Arity) of
+        {AR, AN} -> {ok, AR, AN, Args};
        false -> error
      end;
    false ->
@@ -229,7 +215,7 @@ expand_quoted(Meta, Receiver, Name, Arity, Quoted, E) ->
  end.

 caller(Line, #{module := nil} = E) ->
-  {elixir_compiler, '__FILE__', 2, location(Line, E)};
+  {elixir_compiler_0, '__FILE__', 1, location(Line, E)};
 caller(Line, #{module := Module, function := nil} = E) ->
  {Module, '__MODULE__', 0, location(Line, E)};
 caller(Line, #{module := Module, function := {Name, Arity}} = E) ->
@@ -339,163 +325,6 @@ elixir_imported_macros() ->
    error:undef -> []
  end.

-rewrite(?atom, to_string, [Arg], _) ->
-  {ok, erlang, atom_to_binary, [Arg, utf8]};
-rewrite(?kernel, elem, [Tuple, Index], _) ->
-  {ok, erlang, element, [increment(Index), Tuple]};
-rewrite(?kernel, put_elem, [Tuple, Index, Value], _) ->
-  {ok, erlang, setelement, [increment(Index), Tuple, Value]};
-rewrite(?map, 'has_key?', [Map, Key], _) ->
-  {ok, maps, is_key, [Key, Map]};
-rewrite(?map, fetch, [Map, Key], _) ->
-  {ok, maps, find, [Key, Map]};
-rewrite(?map, put, [Map, Key, Value], _) ->
-  {ok, maps, put, [Key, Value, Map]};
-rewrite(?map, delete, [Map, Key], _) ->
-  {ok, maps, remove, [Key, Map]};
-rewrite(?process, monitor, [Arg], _) ->
-  {ok, erlang, monitor, [process, Arg]};
-rewrite(?string, to_atom, [Arg], _) ->
-  {ok, erlang, binary_to_atom, [Arg, utf8]};
-rewrite(?string, to_existing_atom, [Arg], _) ->
-  {ok, erlang, binary_to_existing_atom, [Arg, utf8]};
-rewrite(?tuple, insert_at, [Tuple, Index, Term], _) ->
-  {ok, erlang, insert_element, [increment(Index), Tuple, Term]};
-rewrite(?tuple, delete_at, [Tuple, Index], _) ->
-  {ok, erlang, delete_element, [increment(Index), Tuple]};
-rewrite(?tuple, duplicate, [Data, Size], _) ->
-  {ok, erlang, make_tuple, [Size, Data]};
-
-rewrite(Receiver, Name, Args, Arity) ->
-  case inline(Receiver, Name, Arity) of
-    {AR, AN} -> {ok, AR, AN, Args};
-    false    -> false
-  end.
-
-increment(Number) when is_number(Number) ->
-  Number + 1;
-increment(Other) ->
-  {{'.', [], [erlang, '+']}, [], [Other, 1]}.
-
-inline(?atom, to_char_list, 1) -> {erlang, atom_to_list};
-inline(?io, iodata_length, 1) -> {erlang, iolist_size};
-inline(?io, iodata_to_binary, 1) -> {erlang, iolist_to_binary};
-inline(?integer, to_string, 1) -> {erlang, integer_to_binary};
-inline(?integer, to_string, 2) -> {erlang, integer_to_binary};
-inline(?integer, to_char_list, 1) -> {erlang, integer_to_list};
-inline(?integer, to_char_list, 2) -> {erlang, integer_to_list};
-inline(?float, to_string, 1) -> {erlang, float_to_binary};
-inline(?float, to_char_list, 1) -> {erlang, float_to_list};
-inline(?list, to_atom, 1) -> {erlang, list_to_atom};
-inline(?list, to_existing_atom, 1) -> {erlang, list_to_existing_atom};
-inline(?list, to_float, 1) -> {erlang, list_to_float};
-inline(?list, to_integer, 1) -> {erlang, list_to_integer};
-inline(?list, to_integer, 2) -> {erlang, list_to_integer};
-inline(?list, to_tuple, 1) -> {erlang, list_to_tuple};
-
-inline(?kernel, '+', 2) -> {erlang, '+'};
-inline(?kernel, '-', 2) -> {erlang, '-'};
-inline(?kernel, '+', 1) -> {erlang, '+'};
-inline(?kernel, '-', 1) -> {erlang, '-'};
-inline(?kernel, '*', 2) -> {erlang, '*'};
-inline(?kernel, '/', 2) -> {erlang, '/'};
-inline(?kernel, '++', 2) -> {erlang, '++'};
-inline(?kernel, '--', 2) -> {erlang, '--'};
-inline(?kernel, 'not', 1) -> {erlang, 'not'};
-inline(?kernel, '<', 2) -> {erlang, '<'};
-inline(?kernel, '>', 2) -> {erlang, '>'};
-inline(?kernel, '<=', 2) -> {erlang, '=<'};
-inline(?kernel, '>=', 2) -> {erlang, '>='};
-inline(?kernel, '==', 2) -> {erlang, '=='};
-inline(?kernel, '!=', 2) -> {erlang, '/='};
-inline(?kernel, '===', 2) -> {erlang, '=:='};
-inline(?kernel, '!==', 2) -> {erlang, '=/='};
-inline(?kernel, abs, 1) -> {erlang, abs};
-inline(?kernel, apply, 2) -> {erlang, apply};
-inline(?kernel, apply, 3) -> {erlang, apply};
-inline(?kernel, binary_part, 3) -> {erlang, binary_part};
-inline(?kernel, bit_size, 1) -> {erlang, bit_size};
-inline(?kernel, byte_size, 1) -> {erlang, byte_size};
-inline(?kernel, 'div', 2) -> {erlang, 'div'};
-inline(?kernel, exit, 1) -> {erlang, exit};
-inline(?kernel, hd, 1) -> {erlang, hd};
-inline(?kernel, is_atom, 1) -> {erlang, is_atom};
-inline(?kernel, is_binary, 1) -> {erlang, is_binary};
-inline(?kernel, is_bitstring, 1) -> {erlang, is_bitstring};
-inline(?kernel, is_boolean, 1) -> {erlang, is_boolean};
-inline(?kernel, is_float, 1) -> {erlang, is_float};
-inline(?kernel, is_function, 1) -> {erlang, is_function};
-inline(?kernel, is_function, 2) -> {erlang, is_function};
-inline(?kernel, is_integer, 1) -> {erlang, is_integer};
-inline(?kernel, is_list, 1) -> {erlang, is_list};
-inline(?kernel, is_map, 1) -> {erlang, is_map};
-inline(?kernel, is_number, 1) -> {erlang, is_number};
-inline(?kernel, is_pid, 1) -> {erlang, is_pid};
-inline(?kernel, is_port, 1) -> {erlang, is_port};
-inline(?kernel, is_reference, 1) -> {erlang, is_reference};
-inline(?kernel, is_tuple, 1) -> {erlang, is_tuple};
-inline(?kernel, length, 1) -> {erlang, length};
-inline(?kernel, make_ref, 0) -> {erlang, make_ref};
-inline(?kernel, map_size, 1) -> {erlang, map_size};
-inline(?kernel, max, 2) -> {erlang, max};
-inline(?kernel, min, 2) -> {erlang, min};
-inline(?kernel, node, 0) -> {erlang, node};
-inline(?kernel, node, 1) -> {erlang, node};
-inline(?kernel, 'rem', 2) -> {erlang, 'rem'};
-inline(?kernel, round, 1) -> {erlang, round};
-inline(?kernel, self, 0) -> {erlang, self};
-inline(?kernel, send, 2) -> {erlang, send};
-inline(?kernel, spawn, 1) -> {erlang, spawn};
-inline(?kernel, spawn, 3) -> {erlang, spawn};
-inline(?kernel, spawn_link, 1) -> {erlang, spawn_link};
-inline(?kernel, spawn_link, 3) -> {erlang, spawn_link};
-inline(?kernel, spawn_monitor, 1) -> {erlang, spawn_monitor};
-inline(?kernel, spawn_monitor, 3) -> {erlang, spawn_monitor};
-inline(?kernel, throw, 1) -> {erlang, throw};
-inline(?kernel, tl, 1) -> {erlang, tl};
-inline(?kernel, trunc, 1) -> {erlang, trunc};
-inline(?kernel, tuple_size, 1) -> {erlang, tuple_size};
-
-inline(?map, keys, 1) -> {maps, keys};
-inline(?map, merge, 2) -> {maps, merge};
-inline(?map, size, 1) -> {maps, size};
-inline(?map, values, 1) -> {maps, values};
-inline(?map, to_list, 1) -> {maps, to_list};
-
-inline(?node, spawn, 2) -> {erlang, spawn};
-inline(?node, spawn, 3) -> {erlang, spawn_opt};
-inline(?node, spawn, 4) -> {erlang, spawn};
-inline(?node, spawn, 5) -> {erlang, spawn_opt};
-inline(?node, spawn_link, 2) -> {erlang, spawn_link};
-inline(?node, spawn_link, 4) -> {erlang, spawn_link};
-
-inline(?process, exit, 2) -> {erlang, exit};
-inline(?process, spawn, 2) -> {erlang, spawn_opt};
-inline(?process, spawn, 4) -> {erlang, spawn_opt};
-inline(?process, demonitor, 1) -> {erlang, demonitor};
-inline(?process, demonitor, 2) -> {erlang, demonitor};
-inline(?process, link, 1) -> {erlang, link};
-inline(?process, unlink, 1) -> {erlang, unlink};
-
-inline(?port, open, 2) -> {erlang, open_port};
-inline(?port, call, 3) -> {erlang, port_call};
-inline(?port, close, 1) -> {erlang, port_close};
-inline(?port, command, 2) -> {erlang, port_command};
-inline(?port, command, 3) -> {erlang, port_command};
-inline(?port, connect, 2) -> {erlang, port_connect};
-inline(?port, control, 3) -> {erlang, port_control};
-inline(?port, info, 1) -> {erlang, port_info};
-inline(?port, info, 2) -> {erlang, port_info};
-inline(?port, list, 0) -> {erlang, ports};
-
-inline(?string, to_float, 1) -> {erlang, binary_to_float};
-inline(?string, to_integer, 1) -> {erlang, binary_to_integer};
-inline(?string, to_integer, 2) -> {erlang, binary_to_integer};
-inline(?system, stacktrace, 0) -> {erlang, get_stacktrace};
-inline(?tuple, to_list, 1) -> {erlang, tuple_to_list};
-
-inline(_, _, _) -> false.
-
 check_deprecation(Meta, Receiver, Name, Arity, #{file := File}) ->
  case deprecation(Receiver, Name, Arity) of
    false -> ok;
@@ -519,15 +348,5 @@ deprecation_message(Warning, Message) ->
    Message -> Warning ++ ", " ++ Message
  end.

-deprecation('Elixir.System', 'cmd', 1) ->
-  "use System.cmd/3 instead";
-deprecation('Elixir.Inspect.Algebra', 'pretty', 2) ->
-  "use Inspect.Algebra.format/2 instead";
-deprecation('Elixir.IO.ANSI', 'escape', _) ->
-  "use the new API in IO.ANSI.format/2 instead";
-deprecation('Elixir.IO.ANSI', 'escape_fragment', _) ->
-  "use the new API in IO.ANSI.format_fragment/2 instead";
-deprecation('Elixir.IO.ANSI', 'terminal?', _) ->
-  "use IO.ANSI.enabled?/0 instead";
 deprecation(_, _, _) ->
  false.
@@ -6,12 +6,12 @@
  handle_file_warning/2, handle_file_warning/3, handle_file_error/2]).
 -include("elixir.hrl").

-spec warn(non_neg_integer(), binary(), iolist()) -> ok.
+-spec warn(non_neg_integer(), binary(), unicode:chardata()) -> ok.

 warn(Line, File, Warning) when is_integer(Line), is_binary(File) ->
  warn(file_format(Line, File), Warning).

-spec warn(iolist(), iolist()) -> ok.
+-spec warn(unicode:chardata(), unicode:chardata()) -> ok.

 warn(Caller, Warning) ->
  do_warn([Caller, "warning: ", Warning, $\n]).
@@ -31,8 +31,8 @@ form_warn(Meta, File, Module, Desc) when is_list(Meta) ->

 %% Compilation error.

-spec compile_error(list(), binary(), iolist()) -> no_return().
-spec compile_error(list(), binary(), iolist(), list()) -> no_return().
+-spec compile_error(list(), binary(), unicode:charlist()) -> no_return().
+-spec compile_error(list(), binary(), string(), list()) -> no_return().

 compile_error(Meta, File, Message) when is_list(Message) ->
  raise(Meta, File, 'Elixir.CompileError', elixir_utils:characters_to_binary(Message)).
@@ -55,7 +55,23 @@ parse_error(Line, File, Error, <<>>) ->
 parse_error(Line, File, <<"syntax error before: ">>, <<"'end'">>) ->
  do_raise(Line, File, 'Elixir.SyntaxError', <<"unexpected token: end">>);

-%% Binaries are wrapped in [<<...>>], so we need to unwrap them
+%% Produce a human-readable message for errors before a sigil
+parse_error(Line, File, <<"syntax error before: ">>, <<"{sigil,", _Rest/binary>> = Full) ->
+  {ok, Tokens, _} = erl_scan:string(binary_to_list(Full)),
+  {ok, {sigil, _, Sigil, [Content], _}} = erl_parse:parse_term(Tokens ++ [{dot, 1}]),
+  Message = <<"syntax error before: sigil ~", Sigil," with content '", Content/binary, "'">>,
+  do_raise(Line, File, 'Elixir.SyntaxError', Message);
+
+%% Aliases are wrapped in ['']
+parse_error(Line, File, Error, <<"['", Token/binary>>) when is_binary(Error) ->
+  Rest =
+    case binary:split(Token, <<"'">>) of
+      [Part, _] -> Part;
+      _ -> <<>>
+    end,
+  do_raise(Line, File, 'Elixir.SyntaxError', <<Error/binary, Rest/binary>>);
+
+%% Binaries (and interpolation) are wrapped in [<<...>>]
 parse_error(Line, File, Error, <<"[", _/binary>> = Full) when is_binary(Error) ->
  Rest =
    case binary:split(Full, <<"<<">>) of
@@ -127,10 +143,13 @@ handle_file_warning(_, File, {Line,erl_lint,{undefined_behaviour,Module}}) ->
 handle_file_warning(_, _File, {Line,erl_lint,{unused_var,_Var}}) when Line =< 0 ->
  ok;

-%% Ignore shadowed vars as we guarantee no conflicts ourselves
+%% Ignore shadowed and exported vars as we guarantee no conflicts ourselves
 handle_file_warning(_, _File, {_Line,erl_lint,{shadowed_var,_Var,_Where}}) ->
  ok;

+handle_file_warning(_, _File, {_Line,erl_lint,{exported_var,_Var,_Where}}) ->
+  ok;
+
 %% Rewrite nomatch_guard to be more generic it can happen inside if, unless, etc
 handle_file_warning(_, File, {Line, sys_core_fold, nomatch_guard}) ->
  warn(Line, File, "this check/guard will always yield the same result");
@@ -140,6 +159,11 @@ handle_file_warning(_, File, {Line,erl_lint,{unused_var,Var}}) ->
  Message = format_error(erl_lint, {unused_var, format_var(Var)}),
  warn(Line, File, Message);

+%% Handle literal eval failures
+handle_file_warning(_, File, {Line,sys_core_fold,{eval_failure, Error}}) ->
+  #{'__struct__' := Struct} = 'Elixir.Exception':normalize(error, Error),
+  warn(Line, File, ["this expression will fail with ", elixir_aliases:inspect(Struct)]);
+
 %% Default behaviour
 handle_file_warning(_, File, {Line,Module,Desc}) ->
  Message = format_error(Module, Desc),
@@ -241,4 +265,4 @@ do_raise(Line, File, Kind, Message) when is_integer(Line), is_binary(File), is_b
  end,
  Stacktrace = erlang:get_stacktrace(),
  Exception = Kind:exception([{description, Message}, {file, File}, {line, Line}]),
-  erlang:raise(error, Exception, tl(Stacktrace)).
+  erlang:raise(error, Exception, tl(Stacktrace)).
@@ -66,6 +66,8 @@ expand({'__aliases__', _, _} = Alias, E) ->
          elixir_lexical:record_remote(Receiver, ?m(E, lexical_tracker)),
          {Receiver, EA};
        false ->
+          elixir_errors:warn(?m(E, line), ?m(E, file), io_lib:format("an alias must expand to an atom "
+            "at compilation time but got ~ts", ['Elixir.Macro':to_string(hd(EAliases))])),
          {{{'.', [], [elixir_aliases, concat]}, [], [EAliases]}, EA}
      end
  end;
@@ -354,7 +356,7 @@ expand({_, Meta, Args} = Invalid, E) when is_list(Meta) and is_list(Args) ->

 expand({_, _, _} = Tuple, E) ->
  compile_error([{line,0}], ?m(E, file), "invalid quoted expression: ~ts",
-    ['Elixir.Kernel':inspect(Tuple, [{records,false}])]);
+    ['Elixir.Kernel':inspect(Tuple, [])]);

 %% Literals

@@ -456,8 +458,7 @@ assert_no_ambiguous_op(_Atom, _Meta, _Args, _E) ->
  ok.

 expand_local(Meta, Name, Args, #{local := nil, function := nil} = E) ->
-  {EArgs, EA} = expand_args(Args, E),
-  {{Name, Meta, EArgs}, EA};
+  compile_error(Meta, ?m(E, file), "undefined function ~ts/~B", [Name, length(Args)]);
 expand_local(Meta, Name, Args, #{local := nil, module := Module, function := Function} = E) ->
  elixir_locals:record_local({Name, length(Args)}, Module, Function),
  {EArgs, EA} = expand_args(Args, E),
@@ -473,7 +474,8 @@ expand_remote(Receiver, DotMeta, Right, Meta, Args, E, EL) ->
    true -> ok
  end,
  {EArgs, EA} = expand_args(Args, E),
-  {{{'.', DotMeta, [Receiver, Right]}, Meta, EArgs}, elixir_env:mergev(EL, EA)}.
+  {elixir_rewrite:rewrite(Receiver, DotMeta, Right, Meta, EArgs),
+   elixir_env:mergev(EL, EA)}.

 %% Lexical helpers

@@ -488,8 +490,8 @@ validate_opts(Meta, Kind, Allowed, Opts, E) when is_list(Opts) ->
                  "unsupported option ~ts given to ~s", ['Elixir.Kernel':inspect(Key), Kind])
  end || {Key, _} <- Opts, not lists:member(Key, Allowed)];

-validate_opts(Meta, Kind, _Allowed, _Opts, S) ->
-  compile_error(Meta, S#elixir_scope.file, "invalid options for ~s, expected a keyword list", [Kind]).
+validate_opts(Meta, Kind, _Allowed, _Opts, E) ->
+  compile_error(Meta, ?m(E, file), "invalid options for ~s, expected a keyword list", [Kind]).

 no_alias_opts(KV) when is_list(KV) ->
  case lists:keyfind(as, 1, KV) of
@@ -101,7 +101,9 @@ do_receive(Meta, {Key, _}, _Acc, E) ->
 %% Try

 'try'(Meta, [], E) ->
-  compile_error(Meta, ?m(E, file), "missing do keywords in try");
+  compile_error(Meta, ?m(E, file), "missing do keyword in try");
+'try'(Meta, [{do, _}], E) ->
+  compile_error(Meta, ?m(E, file), "missing catch/rescue/after/else keyword in try");
 'try'(Meta, KV, E) when not is_list(KV) ->
  elixir_errors:compile_error(Meta, ?m(E, file), "invalid arguments for try");
 'try'(Meta, KV, E) ->
@@ -126,29 +126,6 @@ collect_filters([H|T], Acc) ->
 collect_filters([], Acc) ->
  {Acc, []}.

-%% If all we have is one enum generator, we check if it is a list
-%% for optimization otherwise fallback to the reduce generator.
-build_inline(Line, [{enum, Meta, Left, Right, Filters}] = Orig, Expr, Into, Var, Acc, S) ->
-  case Right of
-    {cons, _, _, _} ->
-      build_comprehension(Line, Orig, Expr, Into);
-    {Other, _, _} when Other == tuple; Other == map ->
-      build_reduce(Orig, Expr, Into, Acc, S);
-    _ ->
-      Clauses = [{enum, Meta, Left, Var, Filters}],
-
-      {'case', -1, Right, [
-        {clause, -1,
-          [Var],
-          [[elixir_utils:erl_call(Line, erlang, is_list, [Var])]],
-          [build_comprehension(Line, Clauses, Expr, Into)]},
-        {clause, -1,
-          [Var],
-          [],
-          [build_reduce(Clauses, Expr, Into, Acc, S)]}
-      ]}
-  end;
-
 build_inline(Line, Clauses, Expr, Into, _Var, Acc, S) ->
  case lists:all(fun(Clause) -> element(1, Clause) == bin end, Clauses) of
    true  -> build_comprehension(Line, Clauses, Expr, Into);
@@ -165,7 +142,7 @@ build_into(Line, Clauses, Expr, Into, Fun, Acc, S) ->
  MatchExpr = {match, Line,
    {tuple, Line, [Acc, Fun]},
    elixir_utils:erl_call(Line, 'Elixir.Collectable', into, [Into])
- },
+  },

  TryExpr =
    {'try', Line,
@@ -199,10 +176,8 @@ build_reduce(Clauses, Expr, {bin, _, _} = Into, Acc, S) ->

 build_reduce_clause([{enum, Meta, Left, Right, Filters}|T], Expr, Arg, Acc, S) ->
  Line  = ?line(Meta),
-  Inner = build_reduce_clause(T, Expr, Acc, Acc, S),
-
-  True  = pair(Line, cont, Inner),
-  False = pair(Line, cont, Acc),
+  True  = build_reduce_clause(T, Expr, Acc, Acc, S),
+  False = Acc,

  Clauses0 =
    case is_var(Left) of
@@ -218,11 +193,8 @@ build_reduce_clause([{enum, Meta, Left, Right, Filters}|T], Expr, Arg, Acc, S) -
      [Left, Acc], [],
      [join_filters(Line, Filters, True, False)]}|Clauses0],

-  Args  = [Right, pair(Line, cont, Arg), {'fun', Line, {clauses, Clauses1}}],
-  Tuple = elixir_utils:erl_call(Line, 'Elixir.Enumerable', reduce, Args),
-
-  %% Use -1 because in case of no returns we don't care about the result
-  elixir_utils:erl_call(-1, erlang, element, [{integer, Line, 2}, Tuple]);
+  Args  = [Right, Arg, {'fun', Line, {clauses, Clauses1}}],
+  elixir_utils:erl_call(Line, 'Elixir.Enum', reduce, Args);

 build_reduce_clause([{bin, Meta, Left, Right, Filters}|T], Expr, Arg, Acc, S) ->
  Line = ?line(Meta),
@@ -74,104 +74,51 @@ unescape_chars(String) ->
  unescape_chars(String, fun unescape_map/1).

 unescape_chars(String, Map) ->
-  Octals = Map($0) /= false,
-  Hex    = Map($x) == true,
-  unescape_chars(String, Map, Octals, Hex, <<>>).
+  unescape_chars(String, Map, Map($x) == true, <<>>).

-%% Deprecated
+unescape_chars(<<$\\,$x,A,B,Rest/binary>>, Map, true, Acc) when ?is_hex(A), ?is_hex(B) ->
+  append_escaped(Rest, Map, [A,B], true, Acc, 16);

-unescape_chars(<<$\\,A,B,C,Rest/binary>>, Map, true, Hex, Acc) when ?is_octal(A), A =< $3, ?is_octal(B), ?is_octal(C) ->
-  io:format(standard_error, "warning: octals inside strings/sigils/chars are deprecated, got: \\~ts~n", [<<A, B, C>>]),
-  append_escaped(Rest, Map, [A,B,C], true, Hex, Acc, 8);
+unescape_chars(<<$\\,$x,A,Rest/binary>>, Map, true, Acc) when ?is_hex(A) ->
+  append_escaped(Rest, Map, [A], true, Acc, 16);

-unescape_chars(<<$\\,A,B,Rest/binary>>, Map, true, Hex, Acc) when ?is_octal(A), ?is_octal(B) ->
-  io:format(standard_error, "warning: octals inside strings/sigils/chars are deprecated, got: \\~ts~n", [<<A, B>>]),
-  append_escaped(Rest, Map, [A,B], true, Hex, Acc, 8);
+unescape_chars(<<$\\,$x,${,A,$},Rest/binary>>, Map, true, Acc) when ?is_hex(A) ->
+  append_escaped(Rest, Map, [A], true, Acc, 16);

-unescape_chars(<<$\\,$0,Rest/binary>>, Map, true, Hex, Acc) ->
-  append_escaped(Rest, Map, [$0], true, Hex, Acc, 8);
+unescape_chars(<<$\\,$x,${,A,B,$},Rest/binary>>, Map, true, Acc) when ?is_hex(A), ?is_hex(B) ->
+  append_escaped(Rest, Map, [A,B], true, Acc, 16);

-unescape_chars(<<$\\,A,Rest/binary>>, Map, true, Hex, Acc) when ?is_octal(A) ->
-  io:format(standard_error, "warning: octals inside strings/sigils/chars are deprecated, got: \\~ts~n", [<<A>>]),
-  append_escaped(Rest, Map, [A], true, Hex, Acc, 8);
+unescape_chars(<<$\\,$x,${,A,B,C,$},Rest/binary>>, Map, true, Acc) when ?is_hex(A), ?is_hex(B), ?is_hex(C) ->
+  append_escaped(Rest, Map, [A,B,C], true, Acc, 16);

-unescape_chars(<<$\\,$X,A,B,Rest/binary>>, Map, Octal, true, Acc) when ?is_hex(A), ?is_hex(B) ->
-  io:format(standard_error, "warning: \\X inside strings/sigils/chars is deprecated, please use \\x instead~n", []),
-  append_escaped(Rest, Map, [A,B], Octal, true, Acc, 16);
+unescape_chars(<<$\\,$x,${,A,B,C,D,$},Rest/binary>>, Map, true, Acc) when ?is_hex(A), ?is_hex(B), ?is_hex(C), ?is_hex(D) ->
+  append_escaped(Rest, Map, [A,B,C,D], true, Acc, 16);

-unescape_chars(<<$\\,$X,A,Rest/binary>>, Map, Octal, true, Acc) when ?is_hex(A) ->
-  io:format(standard_error, "warning: \\X inside strings/sigils/chars is deprecated, please use \\x instead~n", []),
-  append_escaped(Rest, Map, [A], Octal, true, Acc, 16);
+unescape_chars(<<$\\,$x,${,A,B,C,D,E,$},Rest/binary>>, Map, true, Acc) when ?is_hex(A), ?is_hex(B), ?is_hex(C), ?is_hex(D), ?is_hex(E) ->
+  append_escaped(Rest, Map, [A,B,C,D,E], true, Acc, 16);

-unescape_chars(<<$\\,$X,${,A,$},Rest/binary>>, Map, Octal, true, Acc) when ?is_hex(A) ->
-  io:format(standard_error, "warning: \\X inside strings/sigils/chars is deprecated, please use \\x instead~n", []),
-  append_escaped(Rest, Map, [A], Octal, true, Acc, 16);
+unescape_chars(<<$\\,$x,${,A,B,C,D,E,F,$},Rest/binary>>, Map, true, Acc) when ?is_hex(A), ?is_hex(B), ?is_hex(C), ?is_hex(D), ?is_hex(E), ?is_hex(F) ->
+  append_escaped(Rest, Map, [A,B,C,D,E,F], true, Acc, 16);

-unescape_chars(<<$\\,$X,${,A,B,$},Rest/binary>>, Map, Octal, true, Acc) when ?is_hex(A), ?is_hex(B) ->
-  io:format(standard_error, "warning: \\X inside strings/sigils/chars is deprecated, please use \\x instead~n", []),
-  append_escaped(Rest, Map, [A,B], Octal, true, Acc, 16);
-
-unescape_chars(<<$\\,$X,${,A,B,C,$},Rest/binary>>, Map, Octal, true, Acc) when ?is_hex(A), ?is_hex(B), ?is_hex(C) ->
-  io:format(standard_error, "warning: \\X inside strings/sigils/chars is deprecated, please use \\x instead~n", []),
-  append_escaped(Rest, Map, [A,B,C], Octal, true, Acc, 16);
-
-unescape_chars(<<$\\,$X,${,A,B,C,D,$},Rest/binary>>, Map, Octal, true, Acc) when ?is_hex(A), ?is_hex(B), ?is_hex(C), ?is_hex(D) ->
-  io:format(standard_error, "warning: \\X inside strings/sigils/chars is deprecated, please use \\x instead~n", []),
-  append_escaped(Rest, Map, [A,B,C,D], Octal, true, Acc, 16);
-
-unescape_chars(<<$\\,$X,${,A,B,C,D,E,$},Rest/binary>>, Map, Octal, true, Acc) when ?is_hex(A), ?is_hex(B), ?is_hex(C), ?is_hex(D), ?is_hex(E) ->
-  io:format(standard_error, "warning: \\X inside strings/sigils/chars is deprecated, please use \\x instead~n", []),
-  append_escaped(Rest, Map, [A,B,C,D,E], Octal, true, Acc, 16);
-
-unescape_chars(<<$\\,$X,${,A,B,C,D,E,F,$},Rest/binary>>, Map, Octal, true, Acc) when ?is_hex(A), ?is_hex(B), ?is_hex(C), ?is_hex(D), ?is_hex(E), ?is_hex(F) ->
-  io:format(standard_error, "warning: \\X inside strings/sigils/chars is deprecated, please use \\x instead~n", []),
-  append_escaped(Rest, Map, [A,B,C,D,E,F], Octal, true, Acc, 16);
-
-%% End of deprecated
-
-unescape_chars(<<$\\,$x,A,B,Rest/binary>>, Map, Octal, true, Acc) when ?is_hex(A), ?is_hex(B) ->
-  append_escaped(Rest, Map, [A,B], Octal, true, Acc, 16);
-
-unescape_chars(<<$\\,$x,A,Rest/binary>>, Map, Octal, true, Acc) when ?is_hex(A) ->
-  append_escaped(Rest, Map, [A], Octal, true, Acc, 16);
-
-unescape_chars(<<$\\,$x,${,A,$},Rest/binary>>, Map, Octal, true, Acc) when ?is_hex(A) ->
-  append_escaped(Rest, Map, [A], Octal, true, Acc, 16);
-
-unescape_chars(<<$\\,$x,${,A,B,$},Rest/binary>>, Map, Octal, true, Acc) when ?is_hex(A), ?is_hex(B) ->
-  append_escaped(Rest, Map, [A,B], Octal, true, Acc, 16);
-
-unescape_chars(<<$\\,$x,${,A,B,C,$},Rest/binary>>, Map, Octal, true, Acc) when ?is_hex(A), ?is_hex(B), ?is_hex(C) ->
-  append_escaped(Rest, Map, [A,B,C], Octal, true, Acc, 16);
-
-unescape_chars(<<$\\,$x,${,A,B,C,D,$},Rest/binary>>, Map, Octal, true, Acc) when ?is_hex(A), ?is_hex(B), ?is_hex(C), ?is_hex(D) ->
-  append_escaped(Rest, Map, [A,B,C,D], Octal, true, Acc, 16);
-
-unescape_chars(<<$\\,$x,${,A,B,C,D,E,$},Rest/binary>>, Map, Octal, true, Acc) when ?is_hex(A), ?is_hex(B), ?is_hex(C), ?is_hex(D), ?is_hex(E) ->
-  append_escaped(Rest, Map, [A,B,C,D,E], Octal, true, Acc, 16);
-
-unescape_chars(<<$\\,$x,${,A,B,C,D,E,F,$},Rest/binary>>, Map, Octal, true, Acc) when ?is_hex(A), ?is_hex(B), ?is_hex(C), ?is_hex(D), ?is_hex(E), ?is_hex(F) ->
-  append_escaped(Rest, Map, [A,B,C,D,E,F], Octal, true, Acc, 16);
-
-unescape_chars(<<$\\,$x,_/binary>>, _Map, _Octal, true, _Acc) ->
+unescape_chars(<<$\\,$x,_/binary>>, _Map, true, _Acc) ->
  Msg = <<"missing hex sequence after \\x">>,
  error('Elixir.ArgumentError':exception([{message,Msg}]));

-unescape_chars(<<$\\,Escaped,Rest/binary>>, Map, Octals, Hex, Acc) ->
+unescape_chars(<<$\\,Escaped,Rest/binary>>, Map, Hex, Acc) ->
  case Map(Escaped) of
-    false -> unescape_chars(Rest, Map, Octals, Hex, <<Acc/binary, $\\, Escaped>>);
-    Other -> unescape_chars(Rest, Map, Octals, Hex, <<Acc/binary, Other>>)
+    false -> unescape_chars(Rest, Map, Hex, <<Acc/binary, $\\, Escaped>>);
+    Other -> unescape_chars(Rest, Map, Hex, <<Acc/binary, Other>>)
  end;

-unescape_chars(<<Char, Rest/binary>>, Map, Octals, Hex, Acc) ->
-  unescape_chars(Rest, Map, Octals, Hex, <<Acc/binary, Char>>);
+unescape_chars(<<Char, Rest/binary>>, Map, Hex, Acc) ->
+  unescape_chars(Rest, Map, Hex, <<Acc/binary, Char>>);

-unescape_chars(<<>>, _Map, _Octals, _Hex, Acc) -> Acc.
+unescape_chars(<<>>, _Map, _Hex, Acc) -> Acc.

-append_escaped(Rest, Map, List, Octal, Hex, Acc, Base) ->
+append_escaped(Rest, Map, List, Hex, Acc, Base) ->
  Codepoint = list_to_integer(List, Base),
  try <<Acc/binary, Codepoint/utf8>> of
-    Binary -> unescape_chars(Rest, Map, Octal, Hex, Binary)
+    Binary -> unescape_chars(Rest, Map, Hex, Binary)
  catch
    error:badarg ->
      Msg = <<"invalid or reserved unicode codepoint ", (integer_to_binary(Codepoint))/binary>>,
@@ -1,6 +1,6 @@
 %% Module responsible for tracking lexical information.
 -module(elixir_lexical).
-export([run/2,
+-export([run/3, dest/1,
  record_alias/4, record_alias/2,
  record_import/4, record_import/2,
  record_remote/2, format_error/1
@@ -9,21 +9,26 @@

 -define(tracker, 'Elixir.Kernel.LexicalTracker').

-run(File, Callback) ->
-  case code:is_loaded(?tracker) of
-    {file, _} ->
-      Pid = ?tracker:start_link(),
-      try
-        Callback(Pid)
-      after
-        warn_unused_aliases(File, Pid),
-        warn_unused_imports(File, Pid),
-        unlink(Pid), ?tracker:stop(Pid)
-      end;
+run(File, Dest, Callback) ->
+  case elixir_compiler:get_opt(internal) of
    false ->
+      {ok, Pid} = ?tracker:start_link(Dest),
+      try Callback(Pid) of
+        Res ->
+          warn_unused_aliases(File, Pid),
+          warn_unused_imports(File, Pid),
+          Res
+      after
+        unlink(Pid),
+        ?tracker:stop(Pid)
+      end;
+    true ->
      Callback(nil)
  end.

+dest(nil) -> nil;
+dest(Pid) -> ?tracker:dest(Pid).
+
 %% RECORD

 record_alias(Module, Line, Warn, Ref) ->
@@ -9,7 +9,7 @@
 -export([macro_for/3, local_for/3, local_for/4]).

 -include("elixir.hrl").
-define(attr, '__locals_tracker').
+-define(attr, {elixir, locals_tracker}).
 -define(tracker, 'Elixir.Module.LocalsTracker').

 macro_for(Module, Name, Arity) ->
@@ -72,9 +72,13 @@ rewrite_clause(Else, _) -> Else.
 %% TRACKING

 setup(Module) ->
-  case code:is_loaded(?tracker) of
-    {file, _} -> ets:insert(Module, {?attr, ?tracker:start_link()}), ok;
-    false -> ok
+  case elixir_compiler:get_opt(internal) of
+    false ->
+      {ok, Pid} = ?tracker:start_link(),
+      ets:insert(elixir_module:data_table(Module), {?attr, Pid}),
+      ok;
+    true ->
+      ok
  end.

 cleanup(Module) ->
@@ -104,7 +108,7 @@ if_tracker(Module, Callback) ->
  if_tracker(Module, ok, Callback).

 if_tracker(Module, Default, Callback) ->
-  try ets:lookup_element(Module, ?attr, 2) of
+  try ets:lookup_element(elixir_module:data_table(Module), ?attr, 2) of
    Pid -> Callback(Pid)
  catch
    error:badarg -> Default
@@ -114,7 +118,7 @@ if_tracker(Module, Default, Callback) ->

 cache_env(#{module := Module} = RE) ->
  E = RE#{line := nil,vars := []},
-  try ets:lookup_element(Module, ?attr, 2) of
+  try ets:lookup_element(elixir_module:data_table(Module), ?attr, 2) of
    Pid ->
      {Pid, ?tracker:cache_env(Pid, E)}
  catch
@@ -5,9 +5,11 @@

 expand_map(Meta, [{'|', UpdateMeta, [Left, Right]}], E) ->
  {[ELeft|ERight], EA} = elixir_exp:expand_args([Left|Right], E),
+  validate_kv(Meta, ERight, Right, E),
  {{'%{}', Meta, [{'|', UpdateMeta, [ELeft, ERight]}]}, EA};
 expand_map(Meta, Args, E) ->
  {EArgs, EA} = elixir_exp:expand_args(Args, E),
+  validate_kv(Meta, EArgs, Args, E),
  {{'%{}', Meta, EArgs}, EA}.

 expand_struct(Meta, Left, Right, E) ->
@@ -35,6 +37,15 @@ expand_struct(Meta, Left, Right, E) ->

  {{'%', EMeta, [ELeft, ERight]}, EE}.

+validate_kv(Meta, KV, Original, E) ->
+  lists:foldl(fun
+    ({_K, _V}, Acc) -> Acc + 1;
+    (_, Acc) ->
+      compile_error(Meta, ?m(E, file),
+        "expected key-value pairs in a map, got: ~ts",
+        ['Elixir.Macro':to_string(lists:nth(Acc, Original))])
+  end, 1, KV).
+
 translate_map(Meta, Args, S) ->
  {Assocs, TUpdate, US} = extract_assoc_update(Args, S),
  translate_map(Meta, Assocs, TUpdate, US).
@@ -101,11 +112,11 @@ load_struct(Meta, Name, S) ->
    error:undef ->
      Inspected = elixir_aliases:inspect(Name),

-      case Context of
+      case Context andalso (S#elixir_scope.function == nil) of
        true ->
          compile_error(Meta, S#elixir_scope.file,
-            "cannot access struct ~ts in the same context that defines it as "
-            "the struct fields are not yet accessible", [Inspected]);
+            "cannot access struct ~ts, the struct was not yet defined or the struct is being "
+            "accessed in the same context that defines it", [Inspected]);
        false ->
          compile_error(Meta, S#elixir_scope.file, "~ts.__struct__/0 is undefined, "
            "cannot expand struct ~ts", [Inspected, Inspected])
@@ -139,14 +150,10 @@ translate_map(Meta, Assocs, TUpdate, #elixir_scope{extra=Extra} = S) ->

  Line = ?line(Meta),

-  {TArgs, SA} = lists:mapfoldl(fun
-    ({Key, Value}, Acc) ->
-      {TKey, Acc1}   = KeyFun(Key, Acc),
-      {TValue, Acc2} = ValFun(Value, Acc1#elixir_scope{extra=Extra}),
-      {{Op, ?line(Meta), TKey, TValue}, Acc2};
-    (Other, _Acc) ->
-      compile_error(Meta, S#elixir_scope.file, "expected key-value pairs in map, got: ~ts",
-                     ['Elixir.Macro':to_string(Other)])
+  {TArgs, SA} = lists:mapfoldl(fun({Key, Value}, Acc) ->
+    {TKey, Acc1}   = KeyFun(Key, Acc),
+    {TValue, Acc2} = ValFun(Value, Acc1#elixir_scope{extra=Extra}),
+    {{Op, ?line(Meta), TKey, TValue}, Acc2}
  end, S, Assocs),

  build_map(Line, TUpdate, TArgs, SA).
@@ -1,25 +1,27 @@
 -module(elixir_module).
-export([compile/4, data_table/1, docs_table/1, is_open/1,
-         expand_callback/6, add_beam_chunk/3, format_error/1]).
+-export([data_table/1, defs_table/1, clas_table/1, is_open/1,
+         compile/4, expand_callback/6, add_beam_chunk/3, format_error/1]).
 -include("elixir.hrl").

-define(acc_attr, '__acc_attributes').
-define(docs_attr, '__docs_table').
-define(lexical_attr, '__lexical_tracker').
-define(persisted_attr, '__persisted_attributes').
-define(overridable_attr, '__overridable').
-define(location_attr, '__location').
+-define(acc_attr, {elixir, acc_attributes}).
+-define(lexical_attr, {elixir, lexical_tracker}).
+-define(persisted_attr, {elixir, persisted_attributes}).
+-define(overridable_attr, {elixir, overridable}).
+-define(location_attr, {elixir, location}).

 %% TABLE METHODS

 data_table(Module) ->
-  Module.
+  ets:lookup_element(elixir_modules, Module, 2).

-docs_table(Module) ->
-  ets:lookup_element(Module, ?docs_attr, 2).
+defs_table(Module) ->
+  ets:lookup_element(elixir_modules, Module, 3).
+
+clas_table(Module) ->
+  ets:lookup_element(elixir_modules, Module, 4).

 is_open(Module) ->
-  Module == ets:info(Module, name).
+  ets:lookup(elixir_modules, Module) /= [].

 %% Compilation hook

@@ -34,7 +36,7 @@ compile(Module, Block, Vars, #{line := Line} = Env) when is_atom(Module) ->

  case ?m(LexEnv, lexical_tracker) of
    nil ->
-      elixir_lexical:run(?m(LexEnv, file), fun(Pid) ->
+      elixir_lexical:run(?m(LexEnv, file), nil, fun(Pid) ->
        do_compile(Line, Module, Block, Vars, LexEnv#{lexical_tracker := Pid})
      end);
    _ ->
@@ -49,12 +51,12 @@ do_compile(Line, Module, Block, Vars, E) ->
  check_module_availability(Line, File, Module),

  Docs = elixir_compiler:get_opt(docs),
-  build(Line, File, Module, Docs, ?m(E, lexical_tracker)),
+  {Data, Defs, Clas, Ref} = build(Line, File, Module, Docs, ?m(E, lexical_tracker)),

  try
-    {Result, NE} = eval_form(Line, Module, Block, Vars, E),
+    {Result, NE} = eval_form(Line, Module, Data, Block, Vars, E),

-    _ = case ets:lookup(data_table(Module), 'on_load') of
+    _ = case ets:lookup(Data, 'on_load') of
      [] -> ok;
      [{on_load,OnLoad}] ->
        [elixir_locals:record_local(Tuple, Module) || Tuple <- OnLoad]
@@ -65,14 +67,14 @@ do_compile(Line, Module, Block, Vars, E) ->

    {All, Forms0} = functions_form(Line, File, Module, Def, Defp,
                                   Defmacro, Defmacrop, Exports, Functions),
-    Forms1        = specs_form(Module, Defmacro, Defmacrop, Forms0),
-    Forms2        = types_form(Line, File, Module, Forms1),
-    Forms3        = attributes_form(Line, File, Module, Forms2),
+    Forms1 = specs_form(Data, Defmacro, Defmacrop, Forms0),
+    Forms2 = types_form(Line, File, Data, Forms1),
+    Forms3 = attributes_form(Line, File, Data, Forms2),

    elixir_locals:ensure_no_import_conflict(Line, File, Module, All),

    case Docs of
-      true  -> warn_unused_docs(Line, File, Module, doc);
+      true  -> warn_unused_docs(Line, File, Data, doc);
      false -> false
    end,

@@ -83,65 +85,68 @@ do_compile(Line, Module, Block, Vars, E) ->
      {attribute, Line, module, Module} | Forms3
    ],

-    Binary = load_form(Line, Final, compile_opts(Module), NE),
+    Binary = load_form(Line, Data, Final, compile_opts(Module), NE),
    {module, Module, Binary, Result}
  after
    elixir_locals:cleanup(Module),
-    elixir_def:cleanup(Module),
-    ets:delete(docs_table(Module)),
-    ets:delete(data_table(Module))
+    ets:delete(Data),
+    ets:delete(Defs),
+    ets:delete(Clas),
+    elixir_code_server:call({undefmodule, Ref})
  end.

 %% Hook that builds both attribute and functions and set up common hooks.

 build(Line, File, Module, Docs, Lexical) ->
-  %% Table with meta information about the module.
-  DataTable = data_table(Module),
-
-  OldTable = ets:info(DataTable, name),
-  case OldTable == DataTable of
-    true ->
-      [{OldFile, OldLine}] = ets:lookup_element(OldTable, ?location_attr, 2),
+  case ets:lookup(elixir_modules, Module) of
+    [{Module, _, _, _, OldLine, OldFile}] ->
      Error = {module_in_definition, Module, OldFile, OldLine},
      elixir_errors:form_error([{line, Line}], File, ?MODULE, Error);
-    false ->
+    _ ->
      []
  end,

-  DataTable = ets:new(DataTable, [set, named_table, public]),
-  ets:insert(DataTable, {before_compile, []}),
-  ets:insert(DataTable, {after_compile, []}),
+  Data = ets:new(Module, [set, public]),
+  Defs = ets:new(Module, [set, public]),
+  Clas = ets:new(Module, [bag, public]),
+
+  Ref = elixir_code_server:call({defmodule, self(),
+                                 {Module, Data, Defs, Clas, Line, File}}),
+
+  ets:insert(Data, {before_compile, []}),
+  ets:insert(Data, {after_compile, []}),
+  ets:insert(Data, {moduledoc, nil}),

  case Docs of
-    true -> ets:insert(DataTable, {on_definition, [{'Elixir.Module', compile_doc}]});
-    _    -> ets:insert(DataTable, {on_definition, []})
+    true -> ets:insert(Data, {on_definition, [{'Elixir.Module', compile_doc}]});
+    _    -> ets:insert(Data, {on_definition, []})
  end,

-  Attributes = [behaviour, on_load, spec, type, typep, opaque, callback, compile, external_resource],
-  ets:insert(DataTable, {?acc_attr, [before_compile, after_compile, on_definition, derive|Attributes]}),
-  ets:insert(DataTable, {?persisted_attr, [vsn|Attributes]}),
-  ets:insert(DataTable, {?docs_attr, ets:new(DataTable, [ordered_set, public])}),
-  ets:insert(DataTable, {?lexical_attr, Lexical}),
-  ets:insert(DataTable, {?overridable_attr, []}),
-  ets:insert(DataTable, {?location_attr, [{File, Line}]}),
+  Attributes = [behaviour, on_load, compile, external_resource],
+  ets:insert(Data, {?acc_attr, [before_compile, after_compile, on_definition, derive,
+                                spec, type, typep, opaque, callback|Attributes]}),
+  ets:insert(Data, {?persisted_attr, [vsn|Attributes]}),
+  ets:insert(Data, {?lexical_attr, Lexical}),

-  %% Setup other modules
+  %% Setup definition related modules
  elixir_def:setup(Module),
  elixir_locals:setup(Module),
-  ok.
+  elixir_def_overridable:setup(Module),
+
+  {Data, Defs, Clas, Ref}.

 %% Receives the module representation and evaluates it.

-eval_form(Line, Module, Block, Vars, E) ->
+eval_form(Line, Module, Data, Block, Vars, E) ->
  {Value, EE} = elixir_compiler:eval_forms(Block, Vars, E),
  elixir_def_overridable:store_pending(Module),
  EV = elixir_env:linify({Line, EE#{vars := [], export_vars := nil}}),
-  EC = eval_callbacks(Line, Module, before_compile, [EV], EV),
+  EC = eval_callbacks(Line, Data, before_compile, [EV], EV),
  elixir_def_overridable:store_pending(Module),
  {Value, EC}.

-eval_callbacks(Line, Module, Name, Args, E) ->
-  Callbacks = lists:reverse(ets:lookup_element(data_table(Module), Name, 2)),
+eval_callbacks(Line, Data, Name, Args, E) ->
+  Callbacks = lists:reverse(ets:lookup_element(Data, Name, 2)),

  lists:foldl(fun({M,F}, Acc) ->
    expand_callback(Line, M, F, Args, Acc#{vars := [], export_vars := nil},
@@ -160,13 +165,11 @@ functions_form(Line, File, Module, Def, Defp, Defmacro, Defmacrop, Exports, Body

 %% Add attributes handling to the form

-attributes_form(Line, File, Module, Current) ->
-  Table = data_table(Module),
+attributes_form(Line, File, Data, Current) ->
+  AccAttrs = ets:lookup_element(Data, ?acc_attr, 2),
+  PersistedAttrs = ets:lookup_element(Data, ?persisted_attr, 2),

-  AccAttrs = ets:lookup_element(Table, '__acc_attributes', 2),
-  PersistedAttrs = ets:lookup_element(Table, '__persisted_attributes', 2),
-
-  Transform = fun({Key, Value}, Acc) ->
+  Transform = fun({Key, Value}, Acc) when is_atom(Key) ->
    case lists:member(Key, PersistedAttrs) of
      false -> Acc;
      true  ->
@@ -182,7 +185,8 @@ attributes_form(Line, File, Module, Current) ->
    end
  end,

-  ets:foldl(Transform, Current, Table).
+  Results = ets:select(Data, [{{'$1', '_'}, [{is_atom, '$1'}], ['$_']}]),
+  lists:foldl(Transform, Current, Results).

 process_attribute(Line, File, external_resource, Values) ->
  lists:usort([process_external_resource(Line, File, Value) || Value <- Values]);
@@ -197,27 +201,21 @@ process_external_resource(Line, File, Value) ->

 %% Types

-types_form(Line, File, Module, Forms0) ->
-  case code:ensure_loaded('Elixir.Kernel.Typespec') of
-    {module, 'Elixir.Kernel.Typespec'} ->
-      Types0 = 'Elixir.Module':get_attribute(Module, type) ++
-               'Elixir.Module':get_attribute(Module, typep) ++
-               'Elixir.Module':get_attribute(Module, opaque),
+types_form(Line, File, Data, Forms0) ->
+  case elixir_compiler:get_opt(internal) of
+    false ->
+      Types0 = get_typespec(Data, type) ++ get_typespec(Data, typep)
+                                        ++ get_typespec(Data, opaque),

      Types1 = ['Elixir.Kernel.Typespec':translate_type(Kind, Expr, Doc, Caller) ||
                {Kind, Expr, Doc, Caller} <- Types0],

-      'Elixir.Module':delete_attribute(Module, type),
-      'Elixir.Module':delete_attribute(Module, typep),
-      'Elixir.Module':delete_attribute(Module, opaque),
-
-      warn_unused_docs(Line, File, Module, typedoc),
-
+      warn_unused_docs(Line, File, Data, typedoc),
      Forms1 = types_attributes(Types1, Forms0),
      Forms2 = export_types_attributes(Types1, Forms1),
      typedocs_attributes(Types1, Forms2);

-    {error, _} ->
+    true ->
      Forms0
  end.

@@ -247,23 +245,17 @@ typedocs_attributes(Types, Forms) ->

 %% Specs

-specs_form(Module, Defmacro, Defmacrop, Forms) ->
-  case code:ensure_loaded('Elixir.Kernel.Typespec') of
-    {module, 'Elixir.Kernel.Typespec'} ->
-      Specs0 = 'Elixir.Module':get_attribute(Module, spec) ++
-               'Elixir.Module':get_attribute(Module, callback),
-
+specs_form(Data, Defmacro, Defmacrop, Forms) ->
+  case elixir_compiler:get_opt(internal) of
+    false ->
+      Specs0 = get_typespec(Data, spec) ++ get_typespec(Data, callback),
      Specs1 = ['Elixir.Kernel.Typespec':translate_spec(Kind, Expr, Caller) ||
                {Kind, Expr, Caller} <- Specs0],
      Specs2 = lists:flatmap(fun(Spec) ->
                               translate_macro_spec(Spec, Defmacro, Defmacrop)
                             end, Specs1),
-
-      'Elixir.Module':delete_attribute(Module, spec),
-      'Elixir.Module':delete_attribute(Module, callback),
      specs_attributes(Forms, Specs2);
-
-    {error, _} ->
+    true ->
      Forms
  end.

@@ -307,11 +299,11 @@ compile_opts(Module) ->
    [] -> []
  end.

-load_form(Line, Forms, Opts, #{file := File} = E) ->
-  elixir_compiler:module(Forms, File, Opts, fun(Module, Binary0) ->
+load_form(Line, Data, Forms, Opts, E) ->
+  elixir_compiler:module(Forms, Opts, E, fun(Module, Binary0) ->
    Docs = elixir_compiler:get_opt(docs),
-    Binary = add_docs_chunk(Binary0, Module, Line, Docs),
-    eval_callbacks(Line, Module, after_compile, [E, Binary], E),
+    Binary = add_docs_chunk(Binary0, Data, Line, Docs),
+    eval_callbacks(Line, Data, after_compile, [E, Binary], E),

    case get(elixir_compiled) of
      Current when is_list(Current) ->
@@ -321,7 +313,7 @@ load_form(Line, Forms, Opts, #{file := File} = E) ->
          undefined -> ok;
          PID ->
            Ref = make_ref(),
-            PID ! {module_available, self(), Ref, File, Module, Binary},
+            PID ! {module_available, self(), Ref, ?m(E, file), Module, Binary},
            receive {Ref, ack} -> ok end
        end;
      _ ->
@@ -331,23 +323,30 @@ load_form(Line, Forms, Opts, #{file := File} = E) ->
    Binary
  end).

-add_docs_chunk(Bin, Module, Line, true) ->
+add_docs_chunk(Bin, Data, Line, true) ->
  ChunkData = term_to_binary({elixir_docs_v1, [
-        {docs, get_docs(Module)},
-        {moduledoc, get_moduledoc(Line, Module)}
-    ]}),
+    {docs, get_docs(Data)},
+    {moduledoc, get_moduledoc(Line, Data)}
+  ]}),
  add_beam_chunk(Bin, "ExDc", ChunkData);

 add_docs_chunk(Bin, _, _, _) -> Bin.

-get_docs(Module) ->
-  ordsets:from_list(
+get_docs(Data) ->
+  Match = ets:match(Data, {{doc, '$1'}, '$2', '$3', '$4', '$5'}),
+  lists:usort(
    [{Tuple, Line, Kind, Sig, Doc} ||
-     {Tuple, Line, Kind, Sig, Doc} <- ets:tab2list(docs_table(Module)),
-     Kind =/= type, Kind =/= opaque]).
+     [Tuple, Line, Kind, Sig, Doc] <- Match,
+      Kind =/= type, Kind =/= opaque]).

-get_moduledoc(Line, Module) ->
-  {Line, 'Elixir.Module':get_attribute(Module, moduledoc)}.
+get_moduledoc(Line, Data) ->
+  {Line, ets:lookup_element(Data, moduledoc, 2)}.
+
+get_typespec(Data, Key) ->
+  case ets:lookup(Data, Key) of
+    [{Key, Value}] -> Value;
+    [] -> []
+  end.

 check_module_availability(Line, File, Module) ->
  Reserved = ['Elixir.Any', 'Elixir.BitString', 'Elixir.Function', 'Elixir.PID',
@@ -370,8 +369,8 @@ check_module_availability(Line, File, Module) ->
      ok
  end.

-warn_unused_docs(Line, File, Module, Attribute) ->
-  case ets:member(data_table(Module), Attribute) of
+warn_unused_docs(Line, File, Data, Attribute) ->
+  case ets:member(Data, Attribute) of
    true ->
      elixir_errors:form_warn([{line, Line}], File, ?MODULE, {unused_doc, Attribute});
    _ ->
@@ -7,7 +7,7 @@ Nonterminals
  add_op_eol mult_op_eol hat_op_eol two_op_eol pipe_op_eol stab_op_eol
  arrow_op_eol match_op_eol when_op_eol in_op_eol in_match_op_eol
  type_op_eol rel_op_eol
-  open_paren close_paren empty_paren
+  open_paren close_paren empty_paren eoe
  list list_args open_bracket close_bracket
  tuple open_curly close_curly
  bit_string open_bit close_bit
@@ -16,11 +16,11 @@ Nonterminals
  container_args_base container_args call_args_parens_base call_args_parens parens_call
  call_args_no_parens_one call_args_no_parens_expr call_args_no_parens_comma_expr
  call_args_no_parens_all call_args_no_parens_many call_args_no_parens_many_strict
-  stab stab_eol stab_expr stab_maybe_expr stab_parens_many
+  stab stab_eoe stab_expr stab_maybe_expr stab_parens_many
  kw_eol kw_base kw call_args_no_parens_kw_expr call_args_no_parens_kw
  dot_op dot_alias dot_identifier dot_op_identifier dot_do_identifier
  dot_paren_identifier dot_bracket_identifier
-  do_block fn_eol do_eol end_eol block_eol block_item block_list
+  do_block fn_eoe do_eoe end_eoe block_eoe block_item block_list
  .

 Terminals
@@ -32,13 +32,13 @@ Terminals
  comp_op at_op unary_op and_op or_op arrow_op match_op in_op in_match_op
  type_op dual_op add_op mult_op hat_op two_op pipe_op stab_op when_op assoc_op
  capture_op rel_op
-  'true' 'false' 'nil' 'do' eol ',' '.'
+  'true' 'false' 'nil' 'do' eol ';' ',' '.'
  '(' ')' '[' ']' '{' '}' '<<' '>>' '%{}' '%'
  .

 Rootsymbol grammar.

-%% There are two shift/reduce conflicts coming from call_args_parens.
+%% Two shift/reduce conflicts coming from call_args_parens.
 Expect 2.

 %% Changes in ops and precedence should be reflected on lib/elixir/lib/macro.ex
@@ -58,12 +58,12 @@ Left     130 or_op_eol.       %% ||, |||, or
 Left     140 and_op_eol.      %% &&, &&&, and
 Left     150 comp_op_eol.     %% ==, !=, =~, ===, !==
 Left     160 rel_op_eol.      %% <, >, <=, >=
-Left     170 arrow_op_eol.    %% < (op), (op) > (e.g |>, <<<, >>>)
+Left     170 arrow_op_eol.    %% < (op), (op) > (|>, <<<, >>>, ~>>, <<~, ~>, <~, <~>, <|>)
 Left     180 in_op_eol.       %% in
 Right    200 two_op_eol.      %% ++, --, .., <>
 Left     210 add_op_eol.      %% + (op), - (op)
 Left     220 mult_op_eol.     %% * (op), / (op)
-Left     250 hat_op_eol.      %% ^ (op) (e.g ^^^)
+Left     250 hat_op_eol.      %% ^ (op) (^^^)
 Nonassoc 300 unary_op_eol.    %% +, -, !, ^, not, ~~~
 Left     310 dot_call_op.
 Left     310 dot_op.          %% .
@@ -72,16 +72,16 @@ Nonassoc 330 dot_identifier.

 %%% MAIN FLOW OF EXPRESSIONS

-grammar -> eol : nil.
+grammar -> eoe : nil.
 grammar -> expr_list : to_block('$1').
-grammar -> eol expr_list : to_block('$2').
-grammar -> expr_list eol : to_block('$1').
-grammar -> eol expr_list eol : to_block('$2').
+grammar -> eoe expr_list : to_block('$2').
+grammar -> expr_list eoe : to_block('$1').
+grammar -> eoe expr_list eoe : to_block('$2').
 grammar -> '$empty' : nil.

 % Note expressions are on reverse order
 expr_list -> expr : ['$1'].
-expr_list -> expr_list eol expr : ['$3'|'$1'].
+expr_list -> expr_list eoe expr : ['$3'|'$1'].

 expr -> empty_paren : nil.
 expr -> matched_expr : '$1'.
@@ -202,8 +202,12 @@ access_expr -> bracket_expr : '$1'.
 access_expr -> at_op_eol number : build_unary_op('$1', ?exprs('$2')).
 access_expr -> unary_op_eol number : build_unary_op('$1', ?exprs('$2')).
 access_expr -> capture_op_eol number : build_unary_op('$1', ?exprs('$2')).
-access_expr -> fn_eol stab end_eol : build_fn('$1', build_stab(reverse('$2'))).
+access_expr -> fn_eoe stab end_eoe : build_fn('$1', build_stab(reverse('$2'))).
 access_expr -> open_paren stab close_paren : build_stab(reverse('$2')).
+access_expr -> open_paren stab ';' close_paren : build_stab(reverse('$2')).
+access_expr -> open_paren ';' stab ';' close_paren : build_stab(reverse('$3')).
+access_expr -> open_paren ';' stab close_paren : build_stab(reverse('$3')).
+access_expr -> open_paren ';' close_paren : build_stab([]).
 access_expr -> number : ?exprs('$1').
 access_expr -> signed_number : {element(4, '$1'), meta('$1'), ?exprs('$1')}.
 access_expr -> list : element(1, '$1').
@@ -240,28 +244,32 @@ bracket_at_expr -> at_op_eol access_expr bracket_arg :

 %% Blocks

-do_block -> do_eol 'end' : [[{do,nil}]].
-do_block -> do_eol stab end_eol : [[{do, build_stab(reverse('$2'))}]].
-do_block -> do_eol block_list 'end' : [[{do, nil}|'$2']].
-do_block -> do_eol stab_eol block_list 'end' : [[{do, build_stab(reverse('$2'))}|'$3']].
+do_block -> do_eoe 'end' : [[{do,nil}]].
+do_block -> do_eoe stab end_eoe : [[{do, build_stab(reverse('$2'))}]].
+do_block -> do_eoe block_list 'end' : [[{do, nil}|'$2']].
+do_block -> do_eoe stab_eoe block_list 'end' : [[{do, build_stab(reverse('$2'))}|'$3']].

-fn_eol -> 'fn' : '$1'.
-fn_eol -> 'fn' eol : '$1'.
+eoe -> eol : '$1'.
+eoe -> ';' : '$1'.
+eoe -> eol ';' : '$1'.

-do_eol -> 'do' : '$1'.
-do_eol -> 'do' eol : '$1'.
+fn_eoe -> 'fn' : '$1'.
+fn_eoe -> 'fn' eoe : '$1'.

-end_eol -> 'end' : '$1'.
-end_eol -> eol 'end' : '$2'.
+do_eoe -> 'do' : '$1'.
+do_eoe -> 'do' eoe : '$1'.

-block_eol -> block_identifier : '$1'.
-block_eol -> block_identifier eol : '$1'.
+end_eoe -> 'end' : '$1'.
+end_eoe -> eoe 'end' : '$2'.
+
+block_eoe -> block_identifier : '$1'.
+block_eoe -> block_identifier eoe : '$1'.

 stab -> stab_expr : ['$1'].
-stab -> stab eol stab_expr : ['$3'|'$1'].
+stab -> stab eoe stab_expr : ['$3'|'$1'].

-stab_eol -> stab : '$1'.
-stab_eol -> stab eol : '$1'.
+stab_eoe -> stab : '$1'.
+stab_eoe -> stab eoe : '$1'.

 stab_expr -> expr : '$1'.
 stab_expr -> stab_op_eol stab_maybe_expr : build_op('$1', [], '$2').
@@ -275,8 +283,8 @@ stab_expr -> stab_parens_many when_op expr stab_op_eol stab_maybe_expr :
 stab_maybe_expr -> 'expr' : '$1'.
 stab_maybe_expr -> '$empty' : nil.

-block_item -> block_eol stab_eol : {?exprs('$1'), build_stab(reverse('$2'))}.
-block_item -> block_eol : {?exprs('$1'), nil}.
+block_item -> block_eoe stab_eoe : {?exprs('$1'), build_stab(reverse('$2'))}.
+block_item -> block_eoe : {?exprs('$1'), nil}.

 block_list -> block_item : ['$1'].
 block_list -> block_item block_list : ['$1'|'$2'].
@@ -151,6 +151,10 @@ escape(Expr, Unquote) ->

 %% Quotes an expression and return its quoted Elixir AST.

+quote({unquote_splicing, _, [_]}, _Binding, #elixir_quote{unquote=true}, _) ->
+  argument_error(<<"unquote_splicing only works inside arguments and block contexts, "
+    "wrap it in parens if you want it to work with one-liners">>);
+
 quote(Expr, nil, Q, E) ->
  do_quote(Expr, Q, E);

@@ -242,6 +246,15 @@ do_quote({Left, Right}, Q, E) ->
  {TRight, RQ} = do_quote(Right, LQ, E),
  {{TLeft, TRight}, RQ};

+do_quote(BitString, #elixir_quote{escape=true} = Q, _) when is_bitstring(BitString) ->
+  case bit_size(BitString) rem 8 of
+    0 ->
+      {BitString, Q};
+    Size ->
+      <<Bits:Size, Bytes/binary>> = BitString,
+      {{'<<>>', [], [{'::', [], [Bits, Size]}, Bytes]}, Q}
+  end;
+
 do_quote(Map, #elixir_quote{escape=true} = Q, E) when is_map(Map) ->
  {TT, TQ} = do_quote(maps:to_list(Map), Q, E),
  {{'%{}', [], TT}, TQ};
@@ -251,7 +264,7 @@ do_quote(Tuple, #elixir_quote{escape=true} = Q, E) when is_tuple(Tuple) ->
  {{'{}', [], TT}, TQ};

 do_quote(List, #elixir_quote{escape=true} = Q, E) when is_list(List) ->
-  % The improper case is pretty inefficient, but improper lists are are.
+  %% The improper case is a bit inefficient, but improper lists are rare.
  case reverse_improper(List) of
    {L}       -> do_splice(L, Q, E);
    {L, R}    ->
@@ -259,14 +272,35 @@ do_quote(List, #elixir_quote{escape=true} = Q, E) when is_list(List) ->
      {TR, QR} = do_quote(R, QL, E),
      {update_last(TL, fun(X) -> {'|', [], [X, TR]} end), QR}
  end;
+
+do_quote(Other, #elixir_quote{escape=true} = Q, _)
+    when is_number(Other); is_pid(Other); is_atom(Other) ->
+  {Other, Q};
+
+do_quote(Fun, #elixir_quote{escape=true} = Q, _) when is_function(Fun) ->
+  case (erlang:fun_info(Fun, env) == {env, []}) andalso
+       (erlang:fun_info(Fun, type) == {type, external}) of
+    true  -> {Fun, Q};
+    false -> bad_escape(Fun)
+  end;
+
+do_quote(Other, #elixir_quote{escape=true}, _) ->
+  bad_escape(Other);
+
 do_quote(List, Q, E) when is_list(List) ->
-    do_splice(lists:reverse(List), Q, E);
+  do_splice(lists:reverse(List), Q, E);

 do_quote(Other, Q, _) ->
  {Other, Q}.

 %% Quote helpers

+bad_escape(Arg) ->
+  Msg = <<"cannot escape ", ('Elixir.Kernel':inspect(Arg, []))/binary, ". ",
+          "The supported values are: lists, tuples, maps, atoms, numbers, bitstrings, ",
+          "pids and remote functions in the format &Mod.fun/arity">>,
+  error('Elixir.ArgumentError':exception([{message,Msg}])).
+
 do_quote_call(Left, Meta, Expr, Args, Q, E) ->
  All  = [meta(Meta, Q), Left, {unquote, Meta, [Expr]}, Args,
          Q#elixir_quote.context],
@@ -0,0 +1,224 @@
+-module(elixir_rewrite).
+-export([rewrite/5, inline/3]).
+
+%% Convenience variables
+
+-define(hidden, [{line,-1}]).
+
+-define(atom, 'Elixir.Atom').
+-define(enum, 'Elixir.Enum').
+-define(float, 'Elixir.Float').
+-define(io, 'Elixir.IO').
+-define(integer, 'Elixir.Integer').
+-define(kernel, 'Elixir.Kernel').
+-define(list, 'Elixir.List').
+-define(map, 'Elixir.Map').
+-define(node, 'Elixir.Node').
+-define(port, 'Elixir.Port').
+-define(process, 'Elixir.Process').
+-define(string, 'Elixir.String').
+-define(string_chars, 'Elixir.String.Chars').
+-define(system, 'Elixir.System').
+-define(tuple, 'Elixir.Tuple').
+
+%% Inline
+
+%% Inline rules are straight-forward, they keep the same
+%% number and order of arguments and show up on captures.
+
+inline(?atom, to_char_list, 1) -> {erlang, atom_to_list};
+inline(?io, iodata_length, 1) -> {erlang, iolist_size};
+inline(?io, iodata_to_binary, 1) -> {erlang, iolist_to_binary};
+inline(?integer, to_string, 1) -> {erlang, integer_to_binary};
+inline(?integer, to_string, 2) -> {erlang, integer_to_binary};
+inline(?integer, to_char_list, 1) -> {erlang, integer_to_list};
+inline(?integer, to_char_list, 2) -> {erlang, integer_to_list};
+inline(?float, to_string, 1) -> {erlang, float_to_binary};
+inline(?float, to_char_list, 1) -> {erlang, float_to_list};
+inline(?list, to_atom, 1) -> {erlang, list_to_atom};
+inline(?list, to_existing_atom, 1) -> {erlang, list_to_existing_atom};
+inline(?list, to_float, 1) -> {erlang, list_to_float};
+inline(?list, to_integer, 1) -> {erlang, list_to_integer};
+inline(?list, to_integer, 2) -> {erlang, list_to_integer};
+inline(?list, to_tuple, 1) -> {erlang, list_to_tuple};
+
+inline(?kernel, '+', 2) -> {erlang, '+'};
+inline(?kernel, '-', 2) -> {erlang, '-'};
+inline(?kernel, '+', 1) -> {erlang, '+'};
+inline(?kernel, '-', 1) -> {erlang, '-'};
+inline(?kernel, '*', 2) -> {erlang, '*'};
+inline(?kernel, '/', 2) -> {erlang, '/'};
+inline(?kernel, '++', 2) -> {erlang, '++'};
+inline(?kernel, '--', 2) -> {erlang, '--'};
+inline(?kernel, 'not', 1) -> {erlang, 'not'};
+inline(?kernel, '<', 2) -> {erlang, '<'};
+inline(?kernel, '>', 2) -> {erlang, '>'};
+inline(?kernel, '<=', 2) -> {erlang, '=<'};
+inline(?kernel, '>=', 2) -> {erlang, '>='};
+inline(?kernel, '==', 2) -> {erlang, '=='};
+inline(?kernel, '!=', 2) -> {erlang, '/='};
+inline(?kernel, '===', 2) -> {erlang, '=:='};
+inline(?kernel, '!==', 2) -> {erlang, '=/='};
+inline(?kernel, abs, 1) -> {erlang, abs};
+inline(?kernel, apply, 2) -> {erlang, apply};
+inline(?kernel, apply, 3) -> {erlang, apply};
+inline(?kernel, binary_part, 3) -> {erlang, binary_part};
+inline(?kernel, bit_size, 1) -> {erlang, bit_size};
+inline(?kernel, byte_size, 1) -> {erlang, byte_size};
+inline(?kernel, 'div', 2) -> {erlang, 'div'};
+inline(?kernel, exit, 1) -> {erlang, exit};
+inline(?kernel, hd, 1) -> {erlang, hd};
+inline(?kernel, is_atom, 1) -> {erlang, is_atom};
+inline(?kernel, is_binary, 1) -> {erlang, is_binary};
+inline(?kernel, is_bitstring, 1) -> {erlang, is_bitstring};
+inline(?kernel, is_boolean, 1) -> {erlang, is_boolean};
+inline(?kernel, is_float, 1) -> {erlang, is_float};
+inline(?kernel, is_function, 1) -> {erlang, is_function};
+inline(?kernel, is_function, 2) -> {erlang, is_function};
+inline(?kernel, is_integer, 1) -> {erlang, is_integer};
+inline(?kernel, is_list, 1) -> {erlang, is_list};
+inline(?kernel, is_map, 1) -> {erlang, is_map};
+inline(?kernel, is_number, 1) -> {erlang, is_number};
+inline(?kernel, is_pid, 1) -> {erlang, is_pid};
+inline(?kernel, is_port, 1) -> {erlang, is_port};
+inline(?kernel, is_reference, 1) -> {erlang, is_reference};
+inline(?kernel, is_tuple, 1) -> {erlang, is_tuple};
+inline(?kernel, length, 1) -> {erlang, length};
+inline(?kernel, make_ref, 0) -> {erlang, make_ref};
+inline(?kernel, map_size, 1) -> {erlang, map_size};
+inline(?kernel, max, 2) -> {erlang, max};
+inline(?kernel, min, 2) -> {erlang, min};
+inline(?kernel, node, 0) -> {erlang, node};
+inline(?kernel, node, 1) -> {erlang, node};
+inline(?kernel, 'rem', 2) -> {erlang, 'rem'};
+inline(?kernel, round, 1) -> {erlang, round};
+inline(?kernel, self, 0) -> {erlang, self};
+inline(?kernel, send, 2) -> {erlang, send};
+inline(?kernel, spawn, 1) -> {erlang, spawn};
+inline(?kernel, spawn, 3) -> {erlang, spawn};
+inline(?kernel, spawn_link, 1) -> {erlang, spawn_link};
+inline(?kernel, spawn_link, 3) -> {erlang, spawn_link};
+inline(?kernel, spawn_monitor, 1) -> {erlang, spawn_monitor};
+inline(?kernel, spawn_monitor, 3) -> {erlang, spawn_monitor};
+inline(?kernel, throw, 1) -> {erlang, throw};
+inline(?kernel, tl, 1) -> {erlang, tl};
+inline(?kernel, trunc, 1) -> {erlang, trunc};
+inline(?kernel, tuple_size, 1) -> {erlang, tuple_size};
+
+inline(?map, keys, 1) -> {maps, keys};
+inline(?map, merge, 2) -> {maps, merge};
+inline(?map, size, 1) -> {maps, size};
+inline(?map, values, 1) -> {maps, values};
+inline(?map, to_list, 1) -> {maps, to_list};
+
+inline(?node, spawn, 2) -> {erlang, spawn};
+inline(?node, spawn, 3) -> {erlang, spawn_opt};
+inline(?node, spawn, 4) -> {erlang, spawn};
+inline(?node, spawn, 5) -> {erlang, spawn_opt};
+inline(?node, spawn_link, 2) -> {erlang, spawn_link};
+inline(?node, spawn_link, 4) -> {erlang, spawn_link};
+
+inline(?process, exit, 2) -> {erlang, exit};
+inline(?process, spawn, 2) -> {erlang, spawn_opt};
+inline(?process, spawn, 4) -> {erlang, spawn_opt};
+inline(?process, demonitor, 1) -> {erlang, demonitor};
+inline(?process, demonitor, 2) -> {erlang, demonitor};
+inline(?process, link, 1) -> {erlang, link};
+inline(?process, unlink, 1) -> {erlang, unlink};
+
+inline(?port, open, 2) -> {erlang, open_port};
+inline(?port, call, 3) -> {erlang, port_call};
+inline(?port, close, 1) -> {erlang, port_close};
+inline(?port, command, 2) -> {erlang, port_command};
+inline(?port, command, 3) -> {erlang, port_command};
+inline(?port, connect, 2) -> {erlang, port_connect};
+inline(?port, control, 3) -> {erlang, port_control};
+inline(?port, info, 1) -> {erlang, port_info};
+inline(?port, info, 2) -> {erlang, port_info};
+inline(?port, list, 0) -> {erlang, ports};
+
+inline(?string, to_float, 1) -> {erlang, binary_to_float};
+inline(?string, to_integer, 1) -> {erlang, binary_to_integer};
+inline(?string, to_integer, 2) -> {erlang, binary_to_integer};
+inline(?system, stacktrace, 0) -> {erlang, get_stacktrace};
+inline(?tuple, to_list, 1) -> {erlang, tuple_to_list};
+
+inline(_, _, _) -> false.
+
+%% Rewrite rules
+%% Rewrite rules are more complex than regular inlining code.
+%% It receives all remote call arguments and return quoted
+%% expressions with the new environment.
+
+%% Complex rewrite rules
+
+rewrite(?string_chars, _DotMeta, 'to_string', _Meta, [String]) when is_binary(String) ->
+  String;
+rewrite(?string_chars, DotMeta, 'to_string', Meta, [String]) ->
+  Var   = {'_rewrite', ?hidden, nil},
+  Guard = {{'.', ?hidden, [erlang, is_binary]}, ?hidden, [Var]},
+  Slow  = remote(?string_chars, DotMeta, 'to_string', Meta, [Var]),
+  Fast  = Var,
+
+  {'case', ?hidden, [String, [{do,
+    [{'->', ?hidden, [[{'when', ?hidden, [Var, Guard]}], Fast]},
+     {'->', ?hidden, [[Var], Slow]}]
+  }]]};
+
+rewrite(?enum, DotMeta, 'reverse', Meta, [List]) when is_list(List) ->
+  remote(lists, DotMeta, 'reverse', Meta, [List]);
+rewrite(?enum, DotMeta, 'reverse', Meta, [List]) ->
+  Var   = {'_rewrite', ?hidden, nil},
+  Guard = {{'.', ?hidden, [erlang, is_list]}, ?hidden, [Var]},
+  Slow  = remote(?enum, DotMeta, 'reverse', Meta, [Var]),
+  Fast  = remote(lists, DotMeta, 'reverse', Meta, [Var]),
+
+  {'case', ?hidden, [List, [{do,
+    [{'->', ?hidden, [[{'when', ?hidden, [Var, Guard]}], Fast]},
+     {'->', ?hidden, [[Var], Slow]}]
+  }]]};
+
+rewrite(Receiver, DotMeta, Right, Meta, Args) ->
+  {EReceiver, ERight, EArgs} = rewrite(Receiver, Right, Args),
+  remote(EReceiver, DotMeta, ERight, Meta, EArgs).
+
+%% Simple rewrite rules
+
+rewrite(?atom, to_string, [Arg]) ->
+  {erlang, atom_to_binary, [Arg, utf8]};
+rewrite(?kernel, elem, [Tuple, Index]) ->
+  {erlang, element, [increment(Index), Tuple]};
+rewrite(?kernel, put_elem, [Tuple, Index, Value]) ->
+  {erlang, setelement, [increment(Index), Tuple, Value]};
+rewrite(?map, 'has_key?', [Map, Key]) ->
+  {maps, is_key, [Key, Map]};
+rewrite(?map, fetch, [Map, Key]) ->
+  {maps, find, [Key, Map]};
+rewrite(?map, put, [Map, Key, Value]) ->
+  {maps, put, [Key, Value, Map]};
+rewrite(?map, delete, [Map, Key]) ->
+  {maps, remove, [Key, Map]};
+rewrite(?process, monitor, [Arg]) ->
+  {erlang, monitor, [process, Arg]};
+rewrite(?string, to_atom, [Arg]) ->
+  {erlang, binary_to_atom, [Arg, utf8]};
+rewrite(?string, to_existing_atom, [Arg]) ->
+  {erlang, binary_to_existing_atom, [Arg, utf8]};
+rewrite(?tuple, insert_at, [Tuple, Index, Term]) ->
+  {erlang, insert_element, [increment(Index), Tuple, Term]};
+rewrite(?tuple, delete_at, [Tuple, Index]) ->
+  {erlang, delete_element, [increment(Index), Tuple]};
+rewrite(?tuple, duplicate, [Data, Size]) ->
+  {erlang, make_tuple, [Size, Data]};
+rewrite(Receiver, Fun, Args) ->
+  {Receiver, Fun, Args}.
+
+%% Rewrite helpers
+
+remote(Receiver, DotMeta, Right, Meta, Args) ->
+  {{'.', DotMeta, [Receiver, Right]}, Meta, Args}.
+
+increment(Number) when is_number(Number) ->
+  Number + 1;
+increment(Other) ->
+  {{'.', [], [erlang, '+']}, [], [Other, 1]}.
@@ -7,6 +7,16 @@ start_link() ->

 init(ok) ->
  Workers = [
+    {
+      elixir_config,
+      {elixir_config, start_link, []},
+
+      permanent,                    % Restart  = permanent | transient | temporary
+      2000,                         % Shutdown = brutal_kill | int() >= 0 | infinity
+      worker,                       % Type     = worker | supervisor
+      [elixir_config]               % Modules  = [Module] | dynamic
+   },
+
    {
      elixir_code_server,
      {elixir_code_server, start_link, []},
@@ -33,10 +33,16 @@

 -define(arrow_op3(T1, T2, T3),
  T1 == $<, T2 == $<, T3 == $<;
-  T1 == $>, T2 == $>, T3 == $>).
+  T1 == $>, T2 == $>, T3 == $>;
+  T1 == $~, T2 == $>, T3 == $>;
+  T1 == $<, T2 == $<, T3 == $~;
+  T1 == $<, T2 == $~, T3 == $>;
+  T1 == $<, T2 == $|, T3 == $>).

 -define(arrow_op(T1, T2),
-  T1 == $|, T2 == $>).
+  T1 == $|, T2 == $>;
+  T1 == $~, T2 == $>;
+  T1 == $<, T2 == $~).

 -define(rel_op(T),
  T == $<;
@@ -80,7 +86,7 @@
 -define(type_op(T1, T2),
  T1 == $:, T2 == $:).

-define(pipe_op(T1),
+-define(pipe_op(T),
  T == $|).

 tokenize(String, Line, #elixir_tokenizer{} = Scope) ->
@@ -130,28 +136,6 @@ tokenize([$0,$o,H|T], Line, Scope, Tokens) when ?is_octal(H) ->
  {Rest, Number} = tokenize_octal([H|T], []),
  tokenize(Rest, Line, Scope, [{number, Line, Number}|Tokens]);

-%% Deprecated
-
-tokenize([$0,$X,H|T], Line, Scope, Tokens) when ?is_hex(H) ->
-  io:format("~ts:~w: warning: 0X for hexadecimals is deprecated, please use 0x instead~n",
-          [Scope#elixir_tokenizer.file, Line]),
-  {Rest, Number} = tokenize_hex([H|T], []),
-  tokenize(Rest, Line, Scope, [{number, Line, Number}|Tokens]);
-
-tokenize([$0,$B,H|T], Line, Scope, Tokens) when ?is_bin(H) ->
-  io:format("~ts:~w: warning: 0B for binaries is deprecated, please use 0b instead~n",
-            [Scope#elixir_tokenizer.file, Line]),
-  {Rest, Number} = tokenize_bin([H|T], []),
-  tokenize(Rest, Line, Scope, [{number, Line, Number}|Tokens]);
-
-tokenize([$0,H|T], Line, Scope, Tokens) when ?is_octal(H) ->
-  io:format("~ts:~w: warning: octals starting with leading 0 is deprecated, please use 0o instead, got octal start with: ~ts~n",
-            [Scope#elixir_tokenizer.file, Line, <<$0, H>>]),
-  {Rest, Number} = tokenize_octal([H|T], []),
-  tokenize(Rest, Line, Scope, [{number, Line, Number}|Tokens]);
-
-%% End of deprecated
-
 % Comments

 tokenize([$#|String], Line, Scope, Tokens) ->
@@ -221,73 +205,19 @@ tokenize([$?,$\\,$x,A|T], Line, Scope, Tokens)
  Char = escape_char([$\\,$x,A]),
  tokenize(T, Line, Scope, [{number, Line, Char}|Tokens]);

-%% Deprecated
-
-tokenize([$?,$\\,$X,${,A,B,C,D,E,F,$}|T], Line, Scope, Tokens)
-    when ?is_hex(A), ?is_hex(B), ?is_hex(C), ?is_hex(D), ?is_hex(E), ?is_hex(F) ->
-  Char = escape_char([$\\,$X,${,A,B,C,D,E,F,$}]),
-  tokenize(T, Line, Scope, [{number, Line, Char}|Tokens]);
-
-tokenize([$?,$\\,$X,${,A,B,C,D,E,$}|T], Line, Scope, Tokens)
-    when ?is_hex(A), ?is_hex(B), ?is_hex(C), ?is_hex(D), ?is_hex(E) ->
-  Char = escape_char([$\\,$X,${,A,B,C,D,E,$}]),
-  tokenize(T, Line, Scope, [{number, Line, Char}|Tokens]);
-
-tokenize([$?,$\\,$X,${,A,B,C,D,$}|T], Line, Scope, Tokens)
-    when ?is_hex(A), ?is_hex(B), ?is_hex(C), ?is_hex(D) ->
-  Char = escape_char([$\\,$X,${,A,B,C,D,$}]),
-  tokenize(T, Line, Scope, [{number, Line, Char}|Tokens]);
-
-tokenize([$?,$\\,$X,${,A,B,C,$}|T], Line, Scope, Tokens)
-    when ?is_hex(A), ?is_hex(B), ?is_hex(C) ->
-  Char = escape_char([$\\,$X,${,A,B,C,$}]),
-  tokenize(T, Line, Scope, [{number, Line, Char}|Tokens]);
-
-tokenize([$?,$\\,$X,${,A,B,$}|T], Line, Scope, Tokens)
-    when ?is_hex(A), ?is_hex(B) ->
-  Char = escape_char([$\\,$X,${,A,B,$}]),
-  tokenize(T, Line, Scope, [{number, Line, Char}|Tokens]);
-
-tokenize([$?,$\\,$X,${,A,$}|T], Line, Scope, Tokens)
-    when ?is_hex(A) ->
-  Char = escape_char([$\\,$X,${,A,$}]),
-  tokenize(T, Line, Scope, [{number, Line, Char}|Tokens]);
-
-tokenize([$?,$\\,$X,A,B|T], Line, Scope, Tokens)
-    when ?is_hex(A), ?is_hex(B) ->
-  Char = escape_char([$\\,$X,A,B]),
-  tokenize(T, Line, Scope, [{number, Line, Char}|Tokens]);
-
-tokenize([$?,$\\,$X,A|T], Line, Scope, Tokens)
-    when ?is_hex(A) ->
-  Char = escape_char([$\\,$X,A]),
-  tokenize(T, Line, Scope, [{number, Line, Char}|Tokens]);
-
-tokenize([$?,$\\,A,B,C|T], Line, Scope, Tokens)
-    when ?is_octal(A), A =< $3,?is_octal(B), ?is_octal(C) ->
-  Char = escape_char([$\\,A,B,C]),
-  tokenize(T, Line, Scope, [{number, Line, Char}|Tokens]);
-
-tokenize([$?,$\\,A,B|T], Line, Scope, Tokens)
-    when ?is_octal(A), ?is_octal(B) ->
-  Char = escape_char([$\\,A,B]),
-  tokenize(T, Line, Scope, [{number, Line, Char}|Tokens]);
-
-tokenize([$?,$\\,$0|T], Line, Scope, Tokens) ->
-  tokenize(T, Line, Scope, [{number, Line, 0}|Tokens]);
-
-tokenize([$?,$\\,A|T], Line, Scope, Tokens)
-    when ?is_octal(A) ->
-  Char = escape_char([$\\,A]),
-  tokenize(T, Line, Scope, [{number, Line, Char}|Tokens]);
-
-%% End of deprecation
-
 tokenize([$?,$\\,H|T], Line, Scope, Tokens) ->
  Char = elixir_interpolation:unescape_map(H),
  tokenize(T, Line, Scope, [{number, Line, Char}|Tokens]);

 tokenize([$?,Char|T], Line, Scope, Tokens) ->
+  case handle_char(Char) of
+    {Escape, Name} ->
+      Msg = io_lib:format("found ? followed by codepoint 0x~.16B (~ts), please use ~ts instead",
+                          [Char, Name, Escape]),
+      elixir_errors:warn(Line, Scope#elixir_tokenizer.file, Msg);
+    false ->
+      ok
+  end,
  tokenize(T, Line, Scope, [{number, Line, Char}|Tokens]);

 % Heredocs
@@ -375,10 +305,19 @@ tokenize([$:,T|Rest], Line, Scope, Tokens) when
 % End of line

 tokenize(";" ++ Rest, Line, Scope, []) ->
-  tokenize(Rest, Line, Scope, eol(Line, ';', []));
+  tokenize(Rest, Line, Scope, [{';', Line}]);

-tokenize(";" ++ Rest, Line, Scope, [Top|Tokens]) when element(1, Top) /= eol ->
-  tokenize(Rest, Line, Scope, eol(Line, ';', [Top|Tokens]));
+tokenize(";" ++ Rest, Line, Scope, [Top|_] = Tokens) when element(1, Top) /= ';' ->
+  tokenize(Rest, Line, Scope, [{';', Line}|Tokens]);
+
+tokenize("\\" = Original, Line, _Scope, Tokens) ->
+  {error, {Line, "invalid escape \\ at end of file", []}, Original, Tokens};
+
+tokenize("\\\n" = Original, Line, _Scope, Tokens) ->
+  {error, {Line, "invalid escape \\ at end of file", []}, Original, Tokens};
+
+tokenize("\\\r\n" = Original, Line, _Scope, Tokens) ->
+  {error, {Line, "invalid escape \\ at end of file", []}, Original, Tokens};

 tokenize("\\\n" ++ Rest, Line, Scope, Tokens) ->
  tokenize(Rest, Line + 1, Scope, Tokens);
@@ -387,10 +326,10 @@ tokenize("\\\r\n" ++ Rest, Line, Scope, Tokens) ->
  tokenize(Rest, Line + 1, Scope, Tokens);

 tokenize("\n" ++ Rest, Line, Scope, Tokens) ->
-  tokenize(Rest, Line + 1, Scope, eol(Line, newline, Tokens));
+  tokenize(Rest, Line + 1, Scope, eol(Line, Tokens));

 tokenize("\r\n" ++ Rest, Line, Scope, Tokens) ->
-  tokenize(Rest, Line + 1, Scope, eol(Line, newline, Tokens));
+  tokenize(Rest, Line + 1, Scope, eol(Line, Tokens));

 % Stand-alone tokens

@@ -534,6 +473,10 @@ tokenize([H|_] = String, Line, Scope, Tokens) when ?is_downcase(H); H == $_ ->

 tokenize([T|Rest], Line, Scope, Tokens) when ?is_horizontal_space(T) ->
  handle_space_sensitive_tokens(strip_horizontal_space(Rest), Line, Scope, Tokens);
+tokenize([T|Rest] = Original, Line, _Scope, Tokens) when ?is_invalid_space(T) ->
+  Message = io_lib:format("invalid space character U+~.16B before: ", [T]),
+  {error, {Line, lists:flatten(Message), until_eol(Rest)}, Original, Tokens};
+
 tokenize(T, Line, _Scope, Tokens) ->
  {error, {Line, "invalid token: ", until_eol(T)}, T, Tokens}.

@@ -554,6 +497,18 @@ until_eol("\n" ++ _)   -> [];
 until_eol([])          -> [];
 until_eol([H|T])       -> [H|until_eol(T)].

+handle_char(7)   -> {"\\a", "alert"};
+handle_char($\b) -> {"\\b", "backspace"};
+handle_char($\d) -> {"\\d", "delete"};
+handle_char($\e) -> {"\\e", "escape"};
+handle_char($\f) -> {"\\f", "form feed"};
+handle_char($\n) -> {"\\n", "newline"};
+handle_char($\r) -> {"\\r", "carriage return"};
+handle_char($\s) -> {"\\s", "space"};
+handle_char($\t) -> {"\\t", "tab"};
+handle_char($\v) -> {"\\v", "vertical tab"};
+handle_char(_)  -> false.
+
 escape_char(List) ->
  <<Char/utf8>> = elixir_interpolation:unescape_chars(list_to_binary(List)),
  Char.
@@ -662,9 +617,10 @@ handle_space_sensitive_tokens(String, Line, Scope, Tokens) ->

 %% Helpers

-eol(_Line, _Mod, [{',',_}|_] = Tokens)   -> Tokens;
-eol(_Line, _Mod, [{eol,_,_}|_] = Tokens) -> Tokens;
-eol(Line, Mod, Tokens) -> [{eol,Line,Mod}|Tokens].
+eol(_Line, [{';',_}|_] = Tokens) -> Tokens;
+eol(_Line, [{',',_}|_] = Tokens) -> Tokens;
+eol(_Line, [{eol,_}|_] = Tokens) -> Tokens;
+eol(Line, Tokens) -> [{eol,Line}|Tokens].

 unsafe_to_atom(Part, Line, #elixir_tokenizer{}) when
    is_binary(Part) andalso size(Part) > 255;
@@ -891,7 +847,7 @@ check_call_identifier(_Kind, Line, Atom, [$(|_]) -> {paren_identifier, Line, Ato
 check_call_identifier(_Kind, Line, Atom, [$[|_]) -> {bracket_identifier, Line, Atom};
 check_call_identifier(Kind, Line, Atom, _Rest)   -> {Kind, Line, Atom}.

-add_token_with_nl(Left, [{eol,_,newline}|T]) -> [Left|T];
+add_token_with_nl(Left, [{eol,_}|T]) -> [Left|T];
 add_token_with_nl(Left, T) -> [Left|T].

 %% Error handling
@@ -10,7 +10,7 @@

 translate({'=', Meta, [Left, Right]}, S) ->
  Return = case Left of
-    {'_', _, Atom} when is_atom(Atom) -> false;
+    {'_', _, Atom} when is_atom(Atom) -> S#elixir_scope.return;
    _ -> true
  end,

@@ -195,18 +195,16 @@ translate({Name, Meta, Args}, S) when is_atom(Name), is_list(Meta), is_list(Args
  if
    S#elixir_scope.context == match ->
      compile_error(Meta, S#elixir_scope.file,
-                    "cannot invoke function ~ts/~B inside match", [Name, length(Args)]);
+                    "cannot invoke local ~ts/~B inside match", [Name, length(Args)]);
    S#elixir_scope.context == guard ->
      Arity = length(Args),
      File  = S#elixir_scope.file,
      case Arity of
        0 -> compile_error(Meta, File, "unknown variable ~ts or cannot invoke "
-                           "function ~ts/~B inside guard", [Name, Name, Arity]);
+                           "local ~ts/~B inside guard", [Name, Name, Arity]);
        _ -> compile_error(Meta, File, "cannot invoke local ~ts/~B inside guard",
                           [Name, Arity])
      end;
-    S#elixir_scope.function == nil ->
-      compile_error(Meta, S#elixir_scope.file, "undefined function ~ts/~B", [Name, length(Args)]);
    true ->
      Line = ?line(Meta),
      {TArgs, NS} = translate_args(Args, S),
@@ -259,6 +257,9 @@ translate({{'.', _, [Left, Right]}, Meta, Args}, S)
          %% the is_map/1 guard instead of matching on map. Hopefully
          %% we can use a match on 17.1.
          %%
+          %% In the future, we could also use maps:get/2 instead
+          %% of pattern match, reducing the AST footprint.
+          %%
          %% http://erlang.org/pipermail/erlang-bugs/2014-April/004338.html
          {{'case', -1, TLeft, [
            {clause, -1,
@@ -156,6 +156,16 @@ erl_rescue_guard_for(Meta, Var, 'Elixir.BadStructError') ->
          erl_tuple_size(Meta, Var, 3),
          erl_record_compare(Meta, Var, badstruct));

+erl_rescue_guard_for(Meta, Var, 'Elixir.BadMapError') ->
+  erl_and(Meta,
+          erl_tuple_size(Meta, Var, 2),
+          erl_record_compare(Meta, Var, badmap));
+
+erl_rescue_guard_for(Meta, Var, 'Elixir.KeyError') ->
+  erl_and(Meta,
+          erl_tuple_size(Meta, Var, 2),
+          erl_record_compare(Meta, Var, badkey));
+
 erl_rescue_guard_for(Meta, Var, 'Elixir.ArgumentError') ->
  erl_or(Meta,
         {erl(Meta, '=='), Meta, [Var, badarg]},
@@ -381,8 +381,6 @@ defmodule DictTest.Common do
        dict = new_dict([{1}, {2}, {3}], fn {x} -> {<<x + 64>>, x} end)
        assert Dict.size(dict) == 3
        assert Enum.sort(dict) == [{"A", 1}, {"B", 2}, {"C", 3}]
-
-        assert Collectable.empty(new_dict) == new_dict([])
      end

      test "is zippable" do
@@ -189,11 +189,6 @@ defmodule EnumTest.List do
    assert Enum.into([a: 1, b: 2], %{c: 3}) == %{a: 1, b: 2, c: 3}
    assert Enum.into(%{a: 1, b: 2}, []) == [a: 1, b: 2]
    assert Enum.into([1, 2, 3], "numbers: ", &to_string/1) == "numbers: 123"
-    assert Enum.into([1, 2, 3], fn
-      func, {:cont, x} when is_function(func) -> [x]
-      list, {:cont, x} -> [x|list]
-      list, _ -> list
-    end) == [3, 2, 1]
  end

  test :intersperse do
@@ -368,11 +363,6 @@ defmodule EnumTest.List do
    assert Enum.to_list(1 .. 3) == [1, 2, 3]
  end

-  test :traverse do
-    assert Enum.traverse([1, 2, 3], &(&1 * &1)) == [1, 4, 9]
-    assert Enum.traverse(%{a: 1, b: 2}, fn {k, v} -> {k, v*2} end) == %{a: 2, b: 4}
-  end
-
  test :uniq do
    assert Enum.uniq([1, 2, 3, 2, 1]) == [1, 2, 3]
    assert Enum.uniq([1, 2, 3, 2, 1], fn x -> x end) == [1, 2, 3]
@@ -291,7 +291,7 @@ defmodule Kernel.ExceptionTest do

  test "format_fa" do
    assert Exception.format_fa(fn -> end, 1) =~
-           ~r"#Function<\d\.\d+/0 in Kernel\.ExceptionTest\.test format_fa/1>/1"
+           ~r"#Function<\d+\.\d+/0 in Kernel\.ExceptionTest\.test format_fa/1>/1"
  end

  import Exception, only: [message: 1]
@@ -308,8 +308,10 @@ defmodule Kernel.ExceptionTest do

  test "undefined function message" do
    assert %UndefinedFunctionError{} |> message == "undefined function"
+    assert %UndefinedFunctionError{module: Kernel, function: :bar, arity: 1} |> message ==
+           "undefined function: Kernel.bar/1"
    assert %UndefinedFunctionError{module: Foo, function: :bar, arity: 1} |> message ==
-           "undefined function: Foo.bar/1"
+           "undefined function: Foo.bar/1 (module Foo is not available)"
    assert %UndefinedFunctionError{module: nil, function: :bar, arity: 0} |> message ==
           "undefined function: nil.bar/0"
  end
@@ -325,4 +327,20 @@ defmodule Kernel.ExceptionTest do
    assert %ErlangError{original: :sample} |> message ==
           "erlang error: :sample"
  end
+
+  test "format_stacktrace from file" do
+    assert_raise ArgumentError, fn ->
+      Code.eval_string("def foo do end", [], file: "myfile")
+    end
+
+    assert Exception.format_stacktrace(System.stacktrace) =~ "myfile:1: (file)"
+  end
+
+  test "format_stacktrace from module" do
+    assert_raise ArgumentError, fn ->
+      Code.eval_string("defmodule Foo do raise ArgumentError, ~s(oops) end", [], file: "myfile")
+    end
+
+    assert Exception.format_stacktrace(System.stacktrace) =~ "myfile:1: (module)"
+  end
 end
@@ -1 +1,6 @@
-defmodule CompileSample, do: nil
+defmodule CompileSample, do: nil
+
+# Assert that modules compiled are loaded into memory
+# with the proper destination for the BEAM files.
+dest  = __DIR__ |> Path.join("../../../tmp/#{CompileSample}.beam") |> Path.expand
+^dest = CompileSample |> :code.which() |> List.to_string
@@ -0,0 +1,4 @@
+LF
+CR
CRLF
+LFCR
+
--- a/Show More
+++ b/Show More
@@ -1 +1 @@
 .15.0
 .0.5