Add branch docs publishing

Sources:
* https://dashbit.co/blog/tests-with-warnings-as-errors
* https://hexdocs.pm/mix/master/Mix.Tasks.Test.html

.cirrus.yml

@@ -23,10 +23,10 @@ test_freebsd_task:
   env:
     CHECK_REPRODUCIBLE: true
     LC_ALL: en_US.UTF-8
-    PATH: $PATH:/usr/local/lib/erlang24/bin
+    PATH: $PATH:/usr/local/lib/erlang22/bin
 
   install_script:
-    - pkg install -y erlang-runtime24 git gmake
+    - pkg install -y erlang-runtime22 git gmake
     - rm -rf .git
     - gmake compile
 

.formatter.exs

@@ -14,6 +14,5 @@
 
     # Errors tests
     assert_eval_raise: 3
-  ],
-  normalize_bitstring_modifiers: false
+  ]
 ]

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,20 @@
+### Precheck
+
+* Do not use the issue tracker for help or support (try Elixir Forum, Stack Overflow, IRC, etc.)
+* For proposing a new feature, please start a discussion on the Elixir Core mailing list: https://groups.google.com/group/elixir-lang-core
+* For bugs, do a quick search and make sure the bug has not yet been reported
+* Please disclose security vulnerabilities privately at elixir-security@googlegroups.com
+* Finally, be nice and have fun!
+
+### Environment
+
+* Elixir & Erlang/OTP versions (elixir --version): 
+* Operating system: 
+
+### Current behavior
+
+Include code samples, errors and stacktraces if appropriate.
+
+### Expected behavior
+
+A short description on how you expect the code to behave.

.github/ISSUE_TEMPLATE/config.yml

@@ -1,11 +0,0 @@
----
-blank_issues_enabled: true
-
-contact_links:
-  - name: Discuss proposals
-    url: https://groups.google.com/g/elixir-lang-core
-    about: Send proposals for new ideas to our mailing list
-
-  - name: Ask questions and support
-    url: https://elixirforum.com/
-    about: Ask questions, provide support and more on Elixir Forum

.github/ISSUE_TEMPLATE/issue.yml

@@ -1,53 +0,0 @@
----
-name: Report an issue
-description:
-  Tell us about something that is not working the way we (probably) intend
-body:
-  - type: markdown
-    attributes:
-      value: >
-        Thank you for contributing to Elixir! :heart:
-
-
-        Please, do not use this form for guidance, questions or support.
-        Try instead in [Elixir Forum](https://elixirforum.com),
-        the [IRC Chat](https://web.libera.chat/#elixir),
-        [Stack Overflow](https://stackoverflow.com/questions/tagged/elixir),
-        [Slack](https://elixir-slackin.herokuapp.com),
-        [Discord](https://discord.gg/elixir) or in other online communities.
-
-  - type: textarea
-    id: elixir-and-otp-version
-    attributes:
-      label: Elixir and Erlang/OTP versions
-      description: Paste the output of `elixir --version` here.
-    validations:
-      required: true
-
-  - type: input
-    id: os
-    attributes:
-      label: Operating system
-      description: The operating system that this issue is happening on.
-    validations:
-      required: true
-
-  - type: textarea
-    id: current-behavior
-    attributes:
-      label: Current behavior
-      description: >
-        Include code samples, errors, and stacktraces if appropriate.
-
-
-        If reporting a bug, please include the reproducing steps.
-    validations:
-      required: true
-
-  - type: textarea
-    id: expected-behavior
-    attributes:
-      label: Expected behavior
-      description: A short description on how you expect the code to behave.
-    validations:
-      required: true

.github/dependabot.yml

@@ -1,6 +0,0 @@
-version: 2
-updates:
-  - package-ecosystem: "github-actions"
-    directory: "/"
-    schedule:
-      interval: "weekly"

.github/workflows/builds.hex.pm.yml

@@ -0,0 +1,87 @@
+name: builds.hex.pm
+
+on:
+  push:
+    branches:
+      - main
+      - v*.*
+    tags:
+      - v*
+
+env:
+  ELIXIR_OPTS: "--warnings-as-errors"
+  ERLC_OPTS: "warnings_as_errors"
+  LANG: C.UTF-8
+
+concurrency: builds_txt
+
+jobs:
+  release_pre_built:
+    strategy:
+      fail-fast: true
+      max-parallel: 1
+      matrix:
+        include:
+          - otp: 23
+            otp_version: '23.3'
+            build_docs: build_docs
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 50
+      - name: Get tags
+        run: git fetch --tags origin
+      - uses: ./.github/workflows/release_pre_built
+        with:
+          otp_version: ${{ matrix.otp_version }}
+          otp: ${{ matrix.otp }}
+          build_docs: ${{ matrix.build_docs }}
+      - name: Utils.sh
+        run: |
+          cat << 'EOF' > utils.sh
+          function purge_key() {
+            curl \
+                -X POST \
+                -H "Fastly-Key: ${FASTLY_KEY}" \
+                -H "Accept: application/json" \
+                -H "Content-Length: 0" \
+                "https://api.fastly.com/service/$1/purge/$2"
+          }
+          function purge() {
+            purge_key ${FASTLY_REPO_SERVICE_ID} $1
+            purge_key ${FASTLY_BUILDS_SERVICE_ID} $1
+            sleep 2
+            purge_key ${FASTLY_REPO_SERVICE_ID} $1
+            purge_key ${FASTLY_BUILDS_SERVICE_ID} $1
+            sleep 2
+            purge_key ${FASTLY_REPO_SERVICE_ID} $1
+            purge_key ${FASTLY_BUILDS_SERVICE_ID} $1
+          }
+          EOF
+          chmod +x utils.sh
+      - name: Upload Docs to S3
+        if: ${{ matrix.build_docs }}
+        env:
+          AWS_ACCESS_KEY_ID: ${{ secrets.HEX_AWS_ACCESS_KEY_ID }}
+          AWS_SECRET_ACCESS_KEY: ${{ secrets.HEX_AWS_SECRET_ACCESS_KEY }}
+          AWS_REGION: ${{ secrets.HEX_AWS_REGION }}
+          AWS_S3_BUCKET: ${{ secrets.HEX_AWS_S3_BUCKET }}
+          FASTLY_REPO_SERVICE_ID: ${{ secrets.HEX_FASTLY_REPO_SERVICE_ID }}
+          FASTLY_BUILDS_SERVICE_ID: ${{ secrets.HEX_FASTLY_BUILDS_SERVICE_ID }}
+          FASTLY_KEY: ${{ secrets.HEX_FASTLY_KEY }}
+        run: |
+          source utils.sh
+          version=$(echo ${{ github.ref_name }} | sed -e 's/^v//g')
+          for f in doc/*; do
+              if [ -d "$f" ]; then
+                  app=`echo $f | sed s/"doc\/"//`
+                  tarball="${app}-${version}.tar.gz"
+                  surrogate_key="docs/${app}-${version}"
+                  tar -czf "${tarball}" -C "doc/${app}" .
+                  aws s3 cp "${tarball}" "s3://${{ env.AWS_S3_BUCKET }}/docs/${tarball}" \
+                      --cache-control "public,max-age=3600" \
+                      --metadata "{\"surrogate-key\":\"${surrogate_key}\",\"surrogate-control\":\"public,max-age=604800\"}"
+                  purge "${surrogate_key}"
+              fi
+          done

.github/workflows/ci.yml

@@ -8,35 +8,29 @@ env:
   ERLC_OPTS: "warnings_as_errors"
   LANG: C.UTF-8
 
-permissions:
-  contents: read
-
 jobs:
   test_linux:
-    name: Linux, ${{ matrix.otp_release }}, Ubuntu 18.04
+    name: Linux, ${{ matrix.otp_release }}, Ubuntu 16.04
+    continue-on-error: ${{ matrix.development }}
     strategy:
       fail-fast: false
       matrix:
+        otp_release: ['OTP-24.0', 'OTP-23.3', 'OTP-23.0', 'OTP-22.3', 'OTP-22.0']
+        development: [false]
         include:
-          - otp_release: OTP-25.0
-            otp_latest: true
-          - otp_release: OTP-24.3
-          - otp_release: OTP-24.0
-          - otp_release: OTP-23.3
-          - otp_release: OTP-23.0
           - otp_release: master
             development: true
           - otp_release: maint
             development: true
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-16.04
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v2
         with:
           fetch-depth: 50
       - name: Install Erlang/OTP
         run: |
           cd $RUNNER_TEMP
-          wget -O otp.tar.gz https://repo.hex.pm/builds/otp/ubuntu-18.04/${{ matrix.otp_release }}.tar.gz
+          wget -O otp.tar.gz https://repo.hex.pm/builds/otp/ubuntu-16.04/${{ matrix.otp_release }}.tar.gz
           mkdir -p otp
           tar zxf otp.tar.gz -C otp --strip-components=1
           otp/Install -minimal $(pwd)/otp
@@ -45,52 +39,34 @@ jobs:
         run: |
           rm -rf .git
           make compile
-          echo "$PWD/bin" >> $GITHUB_PATH
       - name: Build info
         run: bin/elixir --version
       - name: Check format
         run: make test_formatted && echo "All Elixir source code files are properly formatted."
-      - name: Run Dialyzer
+      - name: Dyalizer
         run: dialyzer -pa lib/elixir/ebin --build_plt --output_plt elixir.plt --apps lib/elixir/ebin/elixir.beam lib/elixir/ebin/Elixir.Kernel.beam
       - name: Erlang test suite
         run: make test_erlang
-        continue-on-error: ${{ matrix.development }}
       - name: Elixir test suite
         run: make test_elixir
-        continue-on-error: ${{ matrix.development }}
       - name: Check reproducible builds
         run: taskset 1 make check_reproducible
-        if: ${{ matrix.otp_latest }}
-      - name: Build docs
-        if: ${{ matrix.otp_latest }}
-        run: |
-          git config --global advice.detachedHead false
-          EX_DOC_LATEST_STABLE_VERSION=$(curl -s https://hex.pm/api/packages/ex_doc | jq --raw-output '.latest_stable_version')
-          for branch in main v${EX_DOC_LATEST_STABLE_VERSION}; do
-            echo "Building docs with ExDoc ${branch}"
-            cd ..
-            git clone https://github.com/elixir-lang/ex_doc.git --branch ${branch} --depth 1
-            cd ex_doc
-            ../elixir/bin/mix do local.rebar --force + local.hex --force + deps.get + compile
-            cd ../elixir/
-            make docs
-            rm -rf ../ex_doc/
-          done
+        if: matrix.otp_release == 'OTP-24.0'
 
   test_windows:
     name: Windows, OTP-${{ matrix.otp_release }}, Windows Server 2019
     strategy:
       matrix:
-        otp_release: ['23.3']
+        otp_release: ['22.0']
     runs-on: windows-2019
     steps:
       - name: Configure Git
         run: git config --global core.autocrlf input
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v2
         with:
           fetch-depth: 50
       - name: Cache Erlang/OTP package
-        uses: actions/cache@v3
+        uses: actions/cache@v2
         with:
           path: C:\Users\runneradmin\AppData\Local\Temp\chocolatey\erlang
           key: OTP-${{ matrix.otp_release }}-windows-2019
@@ -113,9 +89,9 @@ jobs:
 
   check_posix_compliant:
     name: Check POSIX-compliant
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-16.04
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v2
         with:
           fetch-depth: 50
       - name: Install Shellcheck

.github/workflows/notify.exs

@@ -1,72 +0,0 @@
-# #!/usr/bin/env elixir
-[tag] = System.argv()
-
-Mix.install([
-  {:req, "~> 0.2.1"},
-  {:jason, "~> 1.0"}
-])
-
-%{status: 200, body: release} =
-  Req.get!("https://api.github.com/repos/elixir-lang/elixir/releases/tags/#{tag}")
-
-if release["draft"] do
-  raise "cannot notify a draft release"
-end
-
-## Notify on elixir-lang-ann
-
-names_and_checksums =
-  for asset <- release["assets"],
-      name = asset["name"],
-      name =~ ~r/.sha\d+sum$/,
-      do: {name, Req.get!(asset["browser_download_url"]).body}
-
-line_items =
-  for {name, checksum_and_name} <- Enum.sort(names_and_checksums) do
-    [checksum | _] = String.split(checksum_and_name, " ")
-    root = Path.rootname(name)
-    "." <> type = Path.extname(name)
-    "  * #{root} - #{type} - #{checksum}\n"
-  end
-
-mail = %{
-  "From" => "jose.valim@dashbit.co",
-  "To" => "elixir-lang-ann@googlegroups.com",
-  "Subject" => "Elixir #{tag} released",
-  "HtmlBody" => "https://github.com/elixir-lang/elixir/releases/tag/#{tag}\n\n#{line_items}",
-  "MessageStream" => "outbound"
-}
-
-if System.get_env("DRYRUN") do
-  IO.puts("MAIL")
-  IO.inspect(mail)
-else
-  headers = %{
-    "X-Postmark-Server-Token" => System.fetch_env!("ELIXIR_LANG_ANN_TOKEN")
-  }
-
-  resp = Req.post!("https://api.postmarkapp.com/email", {:json, mail}, headers: headers)
-  IO.puts("#{resp.status} elixir-lang-ann\n#{inspect(resp.body)}")
-end
-
-## Notify on Elixir Forum
-
-post = %{
-  "title" => "Elixir #{tag} released",
-  "raw" => "https://github.com/elixir-lang/elixir/releases/tag/#{tag}\n\n#{release["body"]}",
-  # Elixir News
-  "category" => 28
-}
-
-if System.get_env("DRYRUN") do
-  IO.puts("POST")
-  IO.inspect(post)
-else
-  headers = %{
-    "api-key" => System.fetch_env!("ELIXIR_FORUM_TOKEN"),
-    "api-username" => "Elixir"
-  }
-
-  resp = Req.post!("https://elixirforum.com/posts.json", {:json, post}, headers: headers)
-  IO.puts("#{resp.status} Elixir Forum\n#{inspect(resp.body)}")
-end

.github/workflows/notify.yml

@@ -1,28 +0,0 @@
-name: Notify
-
-on:
-  release:
-    types:
-      - published
-
-permissions:
-  contents: read
-
-jobs:
-  notify:
-    runs-on: ubuntu-18.04
-    name: Notify
-    steps:
-      - uses: actions/checkout@v3
-        with:
-          fetch-depth: 50
-      - uses: erlef/setup-beam@v1
-        with:
-          otp-version: 24.3
-          elixir-version: 1.13.4
-      - name: Run Elixir script
-        env:
-          ELIXIR_FORUM_TOKEN: ${{ secrets.ELIXIR_FORUM_TOKEN }}
-          ELIXIR_LANG_ANN_TOKEN: ${{ secrets.ELIXIR_LANG_ANN_TOKEN }}
-        run: |
-          elixir .github/workflows/notify.exs ${{ github.ref_name }}

.github/workflows/release.yml

@@ -1,96 +0,0 @@
-name: Release
-
-on:
-  push:
-    tags:
-      - v*
-
-env:
-  ELIXIR_OPTS: "--warnings-as-errors"
-  ERLC_OPTS: "warnings_as_errors"
-  LANG: C.UTF-8
-
-jobs:
-  create_draft_release:
-    permissions:
-      contents: write
-    runs-on: ubuntu-18.04
-    env:
-      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-    steps:
-      - name: Create draft release
-        run: |
-          gh release create \
-            --repo ${{ github.repository }} \
-            --title ${{ github.ref_name }} \
-            --notes '' \
-            --draft \
-            ${{ github.ref_name }}
-  release_pre_built:
-    needs: create_draft_release
-    strategy:
-      fail-fast: true
-      matrix:
-        include:
-          - otp: 23
-            otp_version: 23.3
-          - otp: 24
-            otp_version: 24.3
-          - otp: 25
-            otp_version: 25.0
-            build_docs: build_docs
-    runs-on: ubuntu-18.04
-    steps:
-      - uses: actions/checkout@v3
-        with:
-          fetch-depth: 50
-      - uses: erlef/setup-beam@v1
-        with:
-          otp-version: ${{ matrix.otp_version }}
-          version-type: strict
-      - name: Build Elixir Release
-        run: |
-          make Precompiled.zip
-          mv Precompiled.zip elixir-otp-${{ matrix.otp }}.zip
-          shasum -a 1 elixir-otp-${{ matrix.otp }}.zip > elixir-otp-${{ matrix.otp }}.zip.sha1sum
-          shasum -a 256 elixir-otp-${{ matrix.otp }}.zip > elixir-otp-${{ matrix.otp }}.zip.sha256sum
-          echo "$PWD/bin" >> $GITHUB_PATH
-      - name: Upload Pre-built
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        run: |
-          gh release upload --clobber "${{ github.ref_name }}" \
-            elixir-otp-${{ matrix.otp }}.zip \
-            elixir-otp-${{ matrix.otp }}.zip.sha{1,256}sum
-      - name: Get latest stable ExDoc version
-        if: ${{ matrix.build_docs }}
-        run: |
-          EX_DOC_LATEST_STABLE_VERSION=$(curl -s https://hex.pm/api/packages/ex_doc | jq --raw-output '.latest_stable_version')
-          echo "EX_DOC_LATEST_STABLE_VERSION=${EX_DOC_LATEST_STABLE_VERSION}" >> $GITHUB_ENV
-      - uses: actions/checkout@v3
-        if: ${{ matrix.build_docs }}
-        with:
-          repository: elixir-lang/ex_doc
-          ref: v${{ env.EX_DOC_LATEST_STABLE_VERSION }}
-          path: ex_doc
-      - name: Build ex_doc
-        if: ${{ matrix.build_docs }}
-        run: |
-          mv ex_doc ../ex_doc
-          cd ../ex_doc
-          ../elixir/bin/mix do local.rebar --force + local.hex --force + deps.get + compile
-          cd ../elixir
-      - name: Build Docs
-        if: ${{ matrix.build_docs }}
-        run: |
-          make Docs.zip
-          shasum -a 1 Docs.zip > Docs.zip.sha1sum
-          shasum -a 256 Docs.zip > Docs.zip.sha256sum
-      - name: Upload Docs
-        if: ${{ matrix.build_docs }}
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        run: |
-          gh release upload --clobber "${{ github.ref_name }}" \
-            Docs.zip \
-            Docs.zip.sha{1,256}sum

.github/workflows/release_pre_built/action.yml

@@ -0,0 +1,51 @@
+name: "Release pre built"
+description: "Builds elixir release, ExDoc and generates docs"
+inputs:
+  otp:
+    description: "The major OTP version"
+  otp_version:
+    description: "The exact OTP version (major.minor[.patch])"
+  build_docs:
+    description: "If docs have to be built or not"
+runs:
+  using: "composite"
+  steps:
+    - uses: erlef/setup-beam@v1
+      with:
+        otp-version: ${{ inputs.otp_version }}
+        version-type: strict
+    - name: Build Elixir Release
+      shell: bash
+      run: |
+        make Precompiled.zip
+        mv Precompiled.zip elixir-otp-${{ inputs.otp }}.zip
+        shasum -a 1 elixir-otp-${{ inputs.otp }}.zip > elixir-otp-${{ inputs.otp }}.zip.sha1sum
+        shasum -a 256 elixir-otp-${{ inputs.otp }}.zip > elixir-otp-${{ inputs.otp }}.zip.sha256sum
+        echo "$PWD/bin" >> $GITHUB_PATH
+    - name: Get latest stable ExDoc version
+      if: ${{ inputs.build_docs }}
+      shell: bash
+      run: |
+        EX_DOC_LATEST_STABLE_VERSION=$(curl -s https://hex.pm/api/packages/ex_doc | jq --raw-output '.latest_stable_version')
+        echo "EX_DOC_LATEST_STABLE_VERSION=${EX_DOC_LATEST_STABLE_VERSION}" >> $GITHUB_ENV
+    - uses: actions/checkout@v3
+      if: ${{ inputs.build_docs }}
+      with:
+        repository: elixir-lang/ex_doc
+        ref: v${{ env.EX_DOC_LATEST_STABLE_VERSION }}
+        path: ex_doc
+    - name: Build ex_doc
+      if: ${{ inputs.build_docs }}
+      shell: bash
+      run: |
+        mv ex_doc ../ex_doc
+        cd ../ex_doc
+        ../elixir/bin/mix do local.rebar --force, local.hex --force, deps.get, compile
+        cd ../elixir
+    - name: Build Docs
+      if: ${{ inputs.build_docs }}
+      shell: bash
+      run: |
+        make Docs.zip
+        shasum -a 1 Docs.zip > Docs.zip.sha1sum
+        shasum -a 256 Docs.zip > Docs.zip.sha256sum

CHANGELOG.md

@@ -1,513 +1,309 @@
-# Changelog for Elixir v1.14
+# Changelog for Elixir v1.12
 
-Elixir v1.14 brings many improvements to the debugging experience in Elixir
-and data-type inspection. It also includes a new abstraction for easy
-partitioning of processes called `PartitionSupervisor`, as well as improved
-compilation times and error messages.
+Elixir v1.12 is out with improvements to scripting, tighter Erlang/OTP 24 integration, stepped ranges, and dozen of new functions across the standard library. Overall this is a small release, which continues our tradition of bringing Elixir developers quality of life improvements every 6 months.
 
-Elixir v1.14 is the last version to support Erlang/OTP 23. Consider updating
-to Erlang/OTP 24 or Erlang/OTP 25.
+Elixir v1.12 requires Erlang/OTP 22+. We also recommend running `mix local.rebar` after installation to upgrade to the latest Rebar versions, which includes support for Erlang OTP/24+.
 
-## `dbg`
+## Scripting improvements: `Mix.install/2` and `System.trap_signal/3`
 
-`Kernel.dbg/2` is a new macro that's somewhat similar to `IO.inspect/2`, but
-specifically tailored for **debugging**.
+Elixir v1.12 brings new conveniences for those using Elixir for scripting (via `.exs` files). Elixir has been capable of managing dependencies for a quite long time, but it could only be done within Mix projects. In particular, the Elixir team is wary of global dependencies as any scripts that rely on system packages are brittle and hard to reproduce whenever your system changes.
 
-When called, it prints the value of whatever you pass to it, plus the debugged
-code itself as well as its location. This code:
+`Mix.install/2` is meant to be a sweetspot between single-file scripts and full-blown Mix projects. With `Mix.install/2`, you can list your dependencies on top of your scripts. When you execute the script for the first time, Elixir will download, compile, and cache your dependencies before running your script. Future invocations of the script will simply read the compiled artefacts from the cache:
 
 ```elixir
-# In my_file.exs
-feature = %{name: :dbg, inspiration: "Rust"}
-dbg(feature)
-dbg(Map.put(feature, :in_version, "1.14.0"))
+Mix.install([:jason])
+IO.puts Jason.encode!(%{hello: :world})
 ```
 
-Prints this:
+`Mix.install/2` also performs protocol consolidation, which gives script developers an option to execute their code in the most performant format possible.
 
-```shell
-$ elixir my_file.exs
-[my_file.exs:2: (file)]
-feature #=> %{inspiration: "Rust", name: :dbg}
+**Note:** `Mix.install/2` is currently experimental and it may change in future releases.
 
-[my_file.exs:3: (file)]
-Map.put(feature, :in_version, "1.14.0") #=> %{in_version: "1.14.0", inspiration: "Rust", name: :dbg}
+Another improvement to scripting is the ability to trap exit signals via `System.trap_signal/3`. All you need is the signal name and a callback that will be invoked when the signal triggers. For example, ExUnit leverages this functionality to print all currently running tests when you abort the test suite via SIGQUIT (`Ctrl+\\ `):
+
+```
+$ mix test
+.......................................................................
+.....................^\
+
+Aborting test suite, the following have not completed:
+
+* test query building [test/ecto/query_test.exs:48]
+* test placeholders in Repo.insert_all [test/ecto/repo_test.exs:502]
+
+Showing results so far...
+
+78 doctests, 1042 tests, 0 failures
 ```
 
-`dbg/2` can do more. It's a macro, so it *understands Elixir code*. You can see
-that when you pass a series of `|>` pipes to it. `dbg/2` will print the value
-for every step of the pipeline. This code:
+This is particularly useful when your tests get stuck and you want to know which one is the culprit.
 
-```elixir
-# In dbg_pipes.exs
-__ENV__.file
-|> String.split("/", trim: true)
-|> List.last()
-|> File.exists?()
-|> dbg()
+**Important**: Trapping signals may have strong implications on how a system shuts down and behave in production and therefore it is extremely discouraged for libraries to set their own traps. Instead, they should redirect users to configure them themselves. The only cases where it is acceptable for libraries to set their own traps is when using Elixir in script mode, such as in `.exs` files and via Mix tasks.
+
+## Tighter Erlang/OTP 24 integration
+
+Erlang/OTP 24 ships with JIT compilation support and Elixir developers don't have to do anything to reap its benefits. There are many other features in Erlang/OTP 24 to look forwards to and Elixir v1.12 provides integration with many of them: such as support for 16bit floats in bitstrings as well as performance improvements in the compiler and during code evaluation.
+
+Another excellent feature in Erlang/OTP 24 is the implementation of [EEP 54](http://erlang.org/eeps/eep-0054.html), which provides extended error information for many functions in Erlang's stdlib. Elixir v1.12 fully leverages this feature to improve reporting for errors coming from Erlang. For example, in earlier OTP versions, inserting an invalid argument into a ETS table that no longer exists would simply error with `ArgumentError`:
+
+```
+Interactive Elixir (1.11.0)
+iex(1)> ets = :ets.new(:example, [])
+#Reference<0.3845811859.2669281281.223553>
+iex(2)> :ets.delete(ets)
+true
+iex(3)> :ets.insert(ets, :should_be_a_tuple)
+** (ArgumentError) argument error
+    (stdlib 3.15) :ets.insert(#Reference<0.3845811859.2669281281.223553>, :should_be_a_tuple)
 ```
 
-Prints this:
+However, in Elixir v1.12 with Erlang/OTP 24:
 
-```shell
-$ elixir dbg_pipes.exs
-[dbg_pipes.exs:5: (file)]
-__ENV__.file #=> "/home/myuser/dbg_pipes.exs"
-|> String.split("/", trim: true) #=> ["home", "myuser", "dbg_pipes.exs"]
-|> List.last() #=> "dbg_pipes.exs"
-|> File.exists?() #=> true
+```
+Interactive Elixir (1.12.0)
+iex(1)> ets = :ets.new(:example, [])
+#Reference<0.105641012.1058144260.76455>
+iex(2)> :ets.delete(ets)
+true
+iex(3)> :ets.insert(ets, :should_be_a_tuple)
+** (ArgumentError) errors were found at the given arguments:
+
+  * 1st argument: the table identifier does not refer to an existing ETS table
+  * 2nd argument: not a tuple
+
+    (stdlib 3.15) :ets.insert(#Reference<0.105641012.1058144260.76455>, :should_be_a_tuple)
 ```
 
-### IEx and Prying
+Finally, note Rebar v2 no longer works on Erlang/OTP 24+. Mix defaults to Rebar v3 since v1.4, so no changes should be necessary by the huge majority of developers. However, if you are explicitly setting `manager: :rebar` in your dependency, you want to move to Rebar v3 by removing the `:manager` option. Support for unsupported Rebar versions will be removed from Mix in the future.
 
-`dbg/2` supports configurable backends. IEx automatically replaces the default
-backend by one that halts the code execution with `IEx.Pry`, giving developers
-the option to access local variables, imports, and more. This also works with
-pipelines: if you pass a series of `|>` pipe calls to `dbg` (or pipe into it at the
-end, like `|> dbg()`), you'll be able to step through every line in the pipeline.
+## Stepped ranges
 
-You can keep the default behaviour by passing the `--no-pry` option to IEx.
+Elixir has support for ranges from before its v1.0 release. Ranges support only integers and are inclusive, using the mathematic notation `a..b`. Ranges in Elixir are either increasing `1..10` or decreasing `10..1` and the direction of the range was always inferred from the first and last positions. Ranges are always lazy as its values are emitted as they are enumerated rather than being computed upfront.
 
-## PartitionSupervisor
+Unfortunately, due to this inference, it is not possible to have empty ranges. For example, if you want to create a list of `n` elements, you cannot express it with a range from `1..n`, as `1..0` (for `n=0`) is a decreasing range with two elements.
 
-`PartitionSupervisor` is a new module that implements a new supervisor type. The
-partition supervisor is designed to help with situations where you have a single
-supervised process that becomes a bottleneck. If that process's state can be
-easily partitioned, then you can use `PartitionSupervisor` to supervise multiple
-isolated copies of that process running concurrently, each assigned its own
-partition.
+Elixir v1.12 supports stepped ranges via the `first..last//step` notation. For example: `1..10//2` will emit the numbers `1`, `3`, `5`, `7`, and `9`. You can consider the `//` operator as an equivalent to "range division", as it effectively divides the number of elements in the range by `step`, rounding up on inexact scenarios. Steps can be either positive (increasing ranges) or negative (decreasing ranges). Stepped ranges bring more expressive power to Elixir ranges and they elegantly solve the empty range problem, as they allow the direction of the steps to be explicitly declared instead of inferred.
 
-For example, imagine you have an `ErrorReporter` process that you use to report
-errors to a monitoring service.
+As of Elixir v1.12, implicitly decreasing ranges are soft-deprecated and warnings will be emitted in future Elixir versions based on our [deprecation policy](https://hexdocs.pm/elixir/compatibility-and-deprecations.html#deprecations).
 
-```elixir
-# Application supervisor:
-children = [
-  # ...,
-  ErrorReporter
-]
+## Additional functions
 
-Supervisor.start_link(children, strategy: :one_for_one)
-```
+Elixir v1.12 has the additional of many functions across the standard library. The `Enum` module received additions such as `Enum.count_until/2`, `Enum.product/1`, `Enum.zip_with/2`, and more. The `Integer` module now includes `Integer.pow/2` and `Integer.extended_gcd/2`. Finally, the `Kernel` module got two new functions, `Kernel.then/2` and `Kernel.tap/2`, which are specially useful in `|>` pipelines.
 
-As the concurrency of your application goes up, the `ErrorReporter` process
-might receive requests from many other processes and eventually become a
-bottleneck. In a case like this, it could help to spin up multiple copies of the
-`ErrorReporter` process under a `PartitionSupervisor`.
+## v1.12.3 (2021-09-05)
 
-```elixir
-# Application supervisor
-children = [
-  {PartitionSupervisor, child_spec: ErrorReporter, name: Reporters}
-]
-```
-
-The `PartitionSupervisor` will spin up a number of processes equal to
-`System.schedulers_online()` by default (most often one per core). Now, when
-routing requests to `ErrorReporter` processes we can use a `:via` tuple and
-route the requests through the partition supervisor.
-
-```elixir
-partitioning_key = self()
-ErrorReporter.report({:via, PartitionSupervisor, {Reporters, partitioning_key}}, error)
-```
-
-Using `self()` as the partitioning key here means that the same process will
-always report errors to the same `ErrorReporter` process, ensuring a form of
-back-pressure. You can use any term as the partitioning key.
-
-### A Common Example
-
-A common and practical example of a good use case for `PartitionSupervisor` is
-partitioning something like a `DynamicSupervisor`. When starting many processes
-under it, a dynamic supervisor can be a bottleneck, especially if said processes
-take a long time to initialize. Instead of starting a single `DynamicSupervisor`,
-you can start multiple:
-
-```elixir
-children = [
-  {PartitionSupervisor, child_spec: DynamicSupervisor, name: MyApp.DynamicSupervisors}
-]
-
-Supervisor.start_link(children, strategy: :one_for_one)
-```
-
-Now you start processes on the dynamic supervisor for the right partition.
-For instance, you can partition by PID, like in the previous example:
-
-```elixir
-DynamicSupervisor.start_child(
-  {:via, PartitionSupervisor, {MyApp.DynamicSupervisors, self()}},
-  my_child_specification
-)
-```
-
-## Improved errors on binaries and evaluation
-
-Erlang/OTP 25 improved errors on binary construction and evaluation. These improvements
-apply to Elixir as well. Before v1.14, errors when constructing binaries would
-often be hard-to-debug generic "argument errors". With Erlang/OTP 25 and Elixir v1.14,
-more detail is provided for easier debugging. This work is part of [EEP
-54](https://www.erlang.org/eeps/eep-0054).
-
-Before:
-
-```elixir
-int = 1
-bin = "foo"
-int <> bin
-#=> ** (ArgumentError) argument error
-```
-
-Now:
-
-```elixir
-int = 1
-bin = "foo"
-int <> bin
-#=> ** (ArgumentError) construction of binary failed:
-#=>    segment 1 of type 'binary':
-#=>    expected a binary but got: 1
-```
-
-## Slicing with steps
-
-Elixir v1.12 introduced **stepped ranges**, which are ranges where you can
-specify the "step":
-
-```elixir
-Enum.to_list(1..10//3)
-#=> [1, 4, 7, 10]
-```
-
-Stepped ranges are particularly useful for numerical operations involving
-vectors and matrices (see [Nx](https://github.com/elixir-nx/nx), for example).
-However, the Elixir standard library was not making use of stepped ranges in its
-APIs. Elixir v1.14 starts to take advantage of steps with support for stepped
-ranges in a couple of functions. One of them is `Enum.slice/2`:
-
-```elixir
-letters = ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j"]
-Enum.slice(letters, 0..5//2)
-#=> ["a", "c", "e"]
-```
-
-`binary_slice/2` (and `binary_slice/3` for completeness) has been added to the
-`Kernel` module, that works with bytes and also support stepped ranges:
-
-```elixir
-binary_slice("Elixir", 1..5//2)
-#=> "lxr"
-```
-
-## Expression-based inspection and `Inspect` improvements
-
-In Elixir, it's conventional to implement the `Inspect` protocol for opaque
-structs so that they're inspected with a special notation, resembling this:
-
-```elixir
-MapSet.new([:apple, :banana])
-#MapSet<[:apple, :banana]>
-```
-
-This is generally done when the struct content or part of it is private and the
-`%name{...}` representation would reveal fields that are not part of the public
-API.
-
-The downside of the `#name<...>` convention is that *the inspected output is not
-valid Elixir code*. For example, you cannot copy the inspected output and paste
-it into an IEx session.
-
-Elixir v1.14 changes the convention for some of the standard-library structs.
-The `Inspect` implementation for those structs now returns a string with a valid
-Elixir expression that recreates the struct when evaluated. In the `MapSet`
-example above, this is what we have now:
-
-```elixir
-fruits = MapSet.new([:apple, :banana])
-MapSet.put(fruits, :pear)
-#=> MapSet.new([:apple, :banana, :pear])
-```
-
-The `MapSet.new/1` expression evaluates to exactly the struct that we're
-inspecting. This allows us to hide the internals of `MapSet`, while keeping
-it as valid Elixir code. This expression-based inspection has been
-implemented for `Version.Requirement`, `MapSet`, and `Date.Range`.
-
-Finally, we have improved the `Inspect` protocol for structs so that
-fields are inspected in the order they are declared in `defstruct`.
-The option `:optional` has also been added when deriving the `Inspect`
-protocol, giving developers more control over the struct representation.
-See the updated documentation for `Inspect` for a general rundown on
-the approaches and options available.
-
-## v1.14.2 (2022-11-11)
-
-### 1. Enhancements
+### 1. Bug fixes
 
 #### Elixir
 
-  * [Code] Add `Code.eval_quoted_with_env/4` with support for the `:prune_binding` option
-
-#### ExUnit
-
-  * [ExUnit.Case] Allow test cases to not be registered on use
-  * [ExUnit.DocTest] Include `:doctest` and `:doctest_line` as meta tags
-  * [ExUnit.Formatter] Expose `ExUnit.Formatter.format_assertion_diff/4`
-
-#### Mix
-
-  * [Mix] `Mix.install/2` accepts atoms as paths
-
-### 2. Bug fixes
-
-#### Elixir
-
-  * [Code.Formatter] Fix `size*unit` shortcut in bitstring
-  * [Kernel] Generate unique variables for macro expansion of `defguard`
-  * [Protocol] Expand `:for` in protocols with the appropriate env
-
-#### ExUnit
-
-  * [ExUnit] Do not run duplicate cases on `ExUnit.run/1`
-
-#### Mix
-
-  * [mix test] Ensure proper error message when there is no test directory
-
-## v1.14.1 (2022-10-10)
-
-### 1. Enhancements
-
-#### Elixir
-
-  * [Kernel] Perform partial expansion of literals in module attributes
-  * [Kernel] Do not add compile-time dependencies for literals as defaults in `Application.compile_env/3` inside module attributes
-  * [Macro] Add `Macro.expand_literals/2` and `Macro.expand_literals/3`
-  * [System] Add `:close_stdin` to `System.shell/2`
-
-#### Mix
-
-  * [mix test] Accept `--all-warnings` option
-
-## 2. Bug fixes
-
-#### Elixir
-
-  * [Kernel] Fix misleading warning when `:uniq` is given in `for` comprehensions and the result is unused
-  * [Kernel] Improve error message for when there is a conflicting struct and ignoring module conflict
-  * [Kernel] Do not delete `@enforce_keys` attribute after `defstruct` declaration
-  * [Kernel] Do not crash the checker on modules with missing `:debug_info` chunk
-  * [Macro] Fix error in `Macro.to_string/2` when converting an AST with `:erlang.binary_to_atom/2`
-  * [String] Fix `String.split/3` and `String.next_grapheme/1` returning invalid results on invalid UTF-8 encoding
-  * [System] Do not close stdin by default in `System.shell/2`
-  * [URI] Do not return `uri.port` as `:undefined` in certain cases in `URI.new/1`
-
-#### ExUnit
-
-  * [ExUnit.DocTest] Do not crash when both `:moduledoc` and functions are specified in `:only`
+  * [Code] Make sure that bindings in the default context returned by `Code.eval_*` functions are not returned as tagged tuples
+  * [Kernel] Do not crash when handling ambiguity errors
+  * [Range] Still match on old range patterns throughout the stdlib
 
 #### IEx
 
-  * [CLI] Fix invalid argument handling when `--no-pry` is given
+  * [IEx.Autocomplete] Do not error autocompletion with module attribute
 
 #### Mix
 
-  * [mix format] Do not cache inputs from `.formatter.exs` so they are properly re-evaluted on every call
+  * [Mix] Rename inconsistent `:exit_code` option to `:exit_status` on `Mix.raise/2`
 
-## v1.14.0 (2022-09-01)
+## v1.12.2 (2021-07-01)
+
+### 1. Bug fixes
+
+#### Elixir
+
+  * [Kernel] Ensure deprecated macros emit warnings
+
+#### Mix
+
+  * [mix deps] Ensure unconstrained rebar deps generate valid mix specifications
+
+### 2. Enhancements
+
+#### Elixir
+
+  * [elixirc] Change the output of `--profile time` to make it easier to detect outliers
+  * [Application] Do not add compile time deps on args to `Application.compile_env/2` and `Application.compile_env!/2`
+  * [Enum] Optimize `Enum.into/3` and `Map.new/2`
+
+#### Mix
+
+  * [mix compile] Compile most recently changed files first
+  * [mix compile, mix run, mix test] Speed up the time taken to load dependencies. This should make the usage of Mix inside projects quite more responsive
+
+## v1.12.1 (2021-05-28)
+
+### 1. Bug fixes
+
+#### Elixir
+
+  * [Code] Make sure `Code.format_string!/2` formats multiline expression inside interpolation on the first run
+  * [Macro] Revert keeping of underscores between digits in camelize
+
+#### Mix
+
+  * [Mix] Make sure `Mix.install/2` expand paths for deps
+  * [mix deps.get] Silence false positives on `httpc` warnings
+  * [mix test] Do not run the whole suite when there are no --failed tests as it won't behave as expected inside umbrellas
+
+## v1.12.0 (2021-05-19)
 
 ### 1. Enhancements
 
 #### EEx
 
-  * [EEx] Support multi-line comments to EEx via `<%!-- --%>`
-  * [EEx] Add `EEx.tokenize/2`
+  * [EEx.Engine] Add `c:EEx.Engine.handle_text/3` callback that receives text metadata
+  * [EEx.Engine] Emit warnings for unused "do" expression in EEx
 
 #### Elixir
 
-  * [Access] Add `Access.slice/1`
-  * [Application] Add `Application.compile_env/4` and `Application.compile_env!/3` to read the compile-time environment inside macros
-  * [Calendar] Support ISO8601 basic format parsing with `DateTime.from_iso8601/2`
-  * [Calendar] Add `day`/`hour`/`minute` on `add`/`diff` across different calendar modules
-  * [Code] Add `:normalize_bitstring_modifiers` to `Code.format_string!/2`
-  * [Code] Emit deprecation and type warnings for invalid options in on `Code.compile_string/2` and `Code.compile_quoted/2`
-  * [Code] Warn if an outdated lexical tracker is given on eval
-  * [Code] Add `Code.env_for_eval/1` and `Code.eval_quoted_with_env/3`
-  * [Code] Improve stacktraces from eval operations on Erlang/OTP 25+
-  * [Code.Fragment] Add support for `__MODULE__` in several functions
-  * [Code.Fragment] Support surround and context suggestions across multiple lines
-  * [Enum] Allow slicing with steps in `Enum.slice/2`
-  * [File] Support `dereference_symlinks: true` in `File.cp/3` and `File.cp_r/3`
-  * [Float] Do not show floats in scientific notation if below `1.0e16` and the fractional value is precisely zero
-  * [Float] Add `Float.min_finite/0` and `Float.max_finite/0`
-  * [Inspect] Improve error reporting when there is a faulty implementation of the `Inspect` protocol
-  * [Inspect] Allow `:optional` when deriving the Inspect protocol for hiding fields that match their default value
-  * [Inspect] Inspect struct fields in the order they are declared in `defstruct`
-  * [Inspect] Use expression-based inspection for `Date.Range`, `MapSet`, and `Version.Requirement`
-  * [IO] Support `Macro.Env` and keywords as stacktrace definitions in `IO.warn/2`
-  * [IO] Add `IO.ANSI.syntax_colors/0` and related configuration to be shared across IEx and `dbg`
-  * [Kernel] Add new `dbg/0-2` macro
-  * [Kernel] Allow any guard expression as the size of a bitstring in a pattern match
-  * [Kernel] Allow composite types with pins as the map key in a pattern match
-  * [Kernel] Print escaped version of control chars when they show up as unexpected tokens
-  * [Kernel] Warn on confusable non-ASCII identifiers
-  * [Kernel] Add `..` as a nullary operator that returns `0..-1//1`
-  * [Kernel] Implement Unicode Technical Standard #39 recommendations. In particular, we warn for confusable scripts and restrict identifiers to single-scripts or highly restrictive mixed-scripts
-  * [Kernel] Automatically perform NFC conversion of identifiers
-  * [Kernel] Add `binary_slice/2` and `binary_slice/3`
-  * [Kernel] Lazily expand module attributes to avoid compile-time deps
-  * [Kernel] Automatically cascade `generated: true` annotations on macro expansion
-  * [Keyword] Add `Keyword.from_keys/2` and `Keyword.replace_lazy/3`
-  * [List] Add `List.keysort/3` with support for a `sorter` function
-  * [Macro] Add `Macro.classify_atom/1` and `Macro.inspect_atom/2`
-  * [Macro] Add `Macro.path/2`
-  * [Macro.Env] Add `Macro.Env.prune_compile_info/1`
-  * [Map] Add `Map.from_keys/2` and `Map.replace_lazy/3`
-  * [MapSet] Add `MapSet.filter/2`, `MapSet.reject/2`, and `MapSet.symmetric_difference/2`
-  * [Node] Add `Node.spawn_monitor/2` and `Node.spawn_monitor/4`
-  * [Module] Support new `@after_verify` attribute for executing code whenever a module is verified
-  * [PartitionSupervisor] Add `PartitionSupervisor` that starts multiple isolated partitions of the same child for scalability
-  * [Path] Add `Path.safe_relative/1` and `Path.safe_relative_to/2`
-  * [Registry] Add `Registry.count_select/2`
-  * [Stream] Add `Stream.duplicate/2` and `Stream.transform/5`
-  * [String] Support empty lookup lists in `String.replace/3`, `String.split/3`, and `String.splitter/3`
-  * [String] Allow slicing with steps in `String.slice/2`
-  * [Task] Add `:zip_input_on_exit` option to `Task.async_stream/3`
-  * [Task] Store `:mfa` in the `Task` struct for reflection purposes
-  * [URI] Add `URI.append_query/2`
-  * [Version] Add `Version.to_string/1`
-  * [Version] Colorize `Version.Requirement` source in the `Inspect` protocol
+  * [Code] Add `Code.cursor_context/2` to return the context of a code snippet
+  * [Code] Do not add newlines around interpolation on code formatting. Note this means formatted code that has interpolation after the line length on Elixir v1.12 won't be considered as formatted on earlier Elixir versions
+  * [Code] Do not add brackets when keywords is used in the access syntax
+  * [Calendar] Support basic datetime format in `Calendar.ISO` parsing functions
+  * [Code] Improve evaluation performance on systems running on Erlang/OTP 24+
+  * [Date] Support steps via `Date.range/3`
+  * [DateTime] Add `offset` to `DateTime.to_iso8601/2` (now `to_iso8601/3`)
+  * [Enum] Add `Enum.count_until/2` and `Enum.count_until/3`
+  * [Enum] Add `Enum.product/1`
+  * [Enum] Add `Enum.zip_with/2`, `Enum.zip_with/3`, `Enum.zip_reduce/3`, and `Enum.zip_reduce/4`
+  * [Enum] Add support for functions as the second argument of `Enum.with_index/2`
+  * [Exception] Show `error_info` data for exceptions coming from Erlang
+  * [Float] Add `Float.pow/2`
+  * [Integer] Add `Integer.pow/2` and `Integer.extended_gcd/2`
+  * [IO] Add `IO.stream/0` and `IO.binstream/0` which default to STDIO with line orientation
+  * [List] Add default value for `List.first/1` and `List.last/1`
+  * [Kernel] Add `first..last//step` as support for stepped ranges
+  * [Kernel] Also warn for literal structs on `min/2` and `max/2`
+  * [Kernel] Add `Kernel.tap/2` and `Kernel.then/2`
+  * [Kernel] Do not add runtime dependencies to remotes in typespecs
+  * [Kernel] When there is an unused variable warning and there is a variable with the same name previously defined, suggest the user may have wanted to use the pin operator
+  * [Kernel] Improve error messages on invalid character right after a number
+  * [Kernel] Show removal and deprecated tips from Erlang/OTP
+  * [Macro] Add export dependencies on `Macro.struct!/2`
+  * [Macro] Support `:newline` to customize newlines escaping in `Macro.unescape_string/2`
+  * [Module] Raise on invalid `@dialyzer` attributes
+  * [Module] Add `Module.get_definition/2` and `Module.delete_definition/2`
+  * [Module] Allow `@on_load` to be a private function
+  * [Module] Validate `@dialyzer` related module attributes
+  * [Module] Add `Module.reserved_attributes/0` to list all reserved attributes by the language
+  * [Range] Add `Range.new/3` and `Range.size/1`
+  * [Regex] Add offset option to `Regex.scan/3` and `Regex.run/3`
+  * [Registry] Support `:compression` on `Registry` tables
+  * [Registry] Support `Registry.values/3` for reading values under a given key-pid pair
+  * [Stream] Add `Stream.zip_with/2` and `Stream.zip_with/3`
+  * [String] Add `:turkic` mode option to String case functions
+  * [String] Update to Unicode 13.0
+  * [System] Add `System.trap_signal/3` and `System.untrap_signal/2`
+  * [System] Add `System.shell/2` to invoke a command that is interpreted by the shell
+  * [Tuple] Add `Tuple.sum/1` and `Tuple.product/1`
+  * [URI] Support RFC3986 compliant encoding and decoding of queries via the `:rfc3986` option
 
 #### ExUnit
 
-  * [ExUnit] Add `ExUnit.Callbacks.start_link_supervised!/2`
-  * [ExUnit] Add `ExUnit.run/1` to rerun test modules
-  * [ExUnit] Colorize summary in yellow with message when all tests are excluded
-  * [ExUnit] Display friendly error when test name is too long
+  * [ExUnit] Intercept SIGQUIT (via Ctrl+\\) and show a list of all aborted tests as well as intermediate test results
+  * [ExUnit] Interpolate module attributes in match assertions diffs
+  * [ExUnit] Print how much time is spent on `async` vs `sync` tests
+  * [ExUnit] Improve error messages for doctests
+  * [ExUnit] Compile doctests faster (often by two times)
+  * [ExUnit] Add `ExUnit.async_run/0` and `ExUnit.await_run/1`
 
 #### IEx
 
-  * [IEx] Evaluate `--dot-iex` line by line
-  * [IEx] Add line-by-line evaluation of IEx breakpoints
-  * [IEx.Autocomplete] Autocomplete bitstrings modifiers (after `::` inside `<<...>>`)
-  * [IEx.Helpers] Allow an atom to be given to `pid/1`
-  * [IEx.Helpers] Support sigils in `h/1`
-
-#### Logger
-
-  * [Logger] Add `Logger.put_process_level/2`
+  * [IEx] Make IEx' parser configurable to allow special commands
+  * [IEx] Show function signature when pressing tab after the opening parens of a function
+  * [IEx] If an IEx expression starts with a binary operator, such as `|>`, automatically pipe in the result of the last expression
 
 #### Mix
 
-  * [Mix] Add `:config_path` and `:lockfile` options to `Mix.install/2`
-  * [mix compile] Add `--no-optional-deps` to skip optional dependencies to test compilation works without optional dependencies
-  * [mix compile] Include column information on error diagnostics when possible
-  * [mix deps] `Mix.Dep.Converger` now tells which deps formed a cycle
-  * [mix do] Support `--app` option to restrict recursive tasks in umbrella projects
-  * [mix do] Allow using `+` as a task separator instead of comma
-  * [mix format] Support filename in `mix format -` when reading from stdin
-  * [mix format] Compile if `mix format` plugins are missing
-  * [mix new] Do not allow projects to be created with application names that conflict with multi-arg Erlang VM switches
-  * [mix profile] Return the return value of the profiled function
-  * [mix release] Make BEAM compression opt-in
-  * [mix release] Let `:runtime_config_path` accept `false` to skip the `config/runtime.exs`
-  * [mix test] Improve error message when suite fails due to coverage
-  * [mix test] Support `:test_elixirc_options` and default to not generating docs nor debug info chunk for tests
-  * [mix xref] Support `--group` flag in `mix xref graph`
+  * [Mix] Add `Mix.install/2` for dynamically installing a list of dependencies
+  * [Mix] Support `:exit_code` option in `Mix.raise/2`
+  * [Mix] Discard `MIX_ENV` and `MIX_TARGET` values if they are empty strings
+  * [Mix] Print the time taken to execute a task with on `MIX_DEBUG=1`
+  * [mix compile.erlang] Compile multiple files in parallel
+  * [mix escript.build] Deep merge configuration and ensure argv is set when executing `config/runtime.exs`
+  * [mix release] Add `RELEASE_PROG` to releases with the name of the executable starting the release
+  * [mix release] Support `remote.vm.args` to customize how the connecting VM boots
+  * [mix test] Run all available tests if there are no pending `--failed` tests. This provides a better workflow as you no longer need to toggle the `--failed` flag between runs
+  * [mix test] Support `mix test --warnings-as-errors`, treating warnings as errors and returning a non-zero exit status (only applies to test files, not compilation)
 
 ### 2. Bug fixes
 
 #### Elixir
 
-  * [Calendar] Handle widths with "0" in them in `Calendar.strftime/3`
-  * [CLI] Improve errors on incorrect `--rpc-eval` usage
-  * [CLI] Return proper exit code on Windows
-  * [Code] Do not emit warnings when formatting code
-  * [Enum] Allow slices to overflow on both starting and ending positions
-  * [Kernel] Do not allow restricted characters in identifiers according to UTS39
-  * [Kernel] Define `__exception__` field as `true` when expanding exceptions in typespecs
-  * [Kernel] Warn if any of `True`, `False`, and `Nil` aliases are used
-  * [Kernel] Warn on underived `@derive` attributes
-  * [Kernel] Remove compile-time dependency from `defimpl :for`
-  * [Kernel] Track all arities on imported functions
-  * [Kernel] Fix equality in guards for dynamic ranges without steps
-  * [Module] Fix loop while unifying type variables
-  * [Protocol] Warn if a protocol has no definitions
-  * [Regex] Show list options when inspecting a Regex manually defined with `Regex.compile/2`
-  * [String] Allow slices to overflow on both starting and ending positions  
-  * [System] Raise non-generic exception on missing env in `System.fetch_env!/1` to mirror map operations
+  * [CLI] Ensure `-e ""` (with an empty string) parses correctly on Windows
+  * [Inspect] Do not override user supplied `:limit` option for derived implementations
+  * [Kernel] Allow heredoc inside a heredoc interpolation
+  * [Kernel] Preserve CRLF on heredocs
+  * [Kernel] Public functions without documentation now appear as an empty map on `Code.fetch_docs/1`, unless they start with underscore, where they remain as `:none`. This aligns Elixir's implementation with EEP48
+  * [Kernel] Do not crash when complex literals (binaries and maps) are used in guards
+  * [Kernel] Properly parse keywords (such as `end`) followed by the `::` operator
+  * [Kernel] Do not ignore unimplemented signatures from generated functions
+  * [Kernel] Improve error message when an expression follows a keyword list without brackets
+  * [Macro] `Macro.decompose_call/1` now also consider tuples with more than 2 elements to not be valid calls
+  * [Macro] Fix `Macro.to_string/1` double-escaping of escape characters in sigils
+  * [Macro] Fix `Macro.underscore/1` on digits preceded by capitals: "FOO10" now becomes "foo10" instead of "fo_o10"
+  * [Macro] Preserve underscores between digits on `Macro.underscore/1`
+  * [OptionParser] Properly parse when numbers follow-up aliases, for example, `-ab3` is now parsed as `-a -b 3`
+  * [Path] Fix `Path.relative_to/2` when referencing self
+  * [Path] Do not crash when a volume is given to `Path.absname/1`, such as "c:"
+  * [Task] Ensure `Task.async_stream/2` with `ordered: false` discard results as they are emitted, instead of needlessly accumulating inside the stream manager
+  * [Task] Raise if `:max_concurrency` is set to 0 on streaming operations
+  * [URI] Do not discard empty paths on `URI.merge/2`
 
 #### ExUnit
 
-  * [ExUnit] Do not crash when diffing unknown bindings in guards
-  * [ExUnit] Properly print diffs when comparing improper lists with strings at the tail position
-  * [ExUnit] Add short hash to `tmp_dir` in ExUnit to avoid test name collision
-  * [ExUnit] Do not store logs in the CLI formatter (this reduces memory usage for suites with `capture_log`)
-  * [ExUnit] Run `ExUnit.after_suite/1` callback even when no tests run
-  * [ExUnit] Fix scenario where `setup` with imported function from within `describe` failed to compile
+  * [ExUnit.Case] Make `@tag tmp_dir` an absolute directory, avoiding inconsistencies if the test changes the current working directory
+  * [ExUnit.Diff] Fix cases where the diffing algorithm would fail to print a pattern correct
 
 #### IEx
 
-  * [IEx] Disallow short-hand pipe after matches
-  * [IEx] Fix `exports/1` in IEx for long function names
+  * [IEx] Fix auto-completion inside remote shells
 
 #### Mix
 
-  * [mix compile.elixir] Fix `--warnings-as-errors` when used with `--all-warnings`
-  * [mix compile.elixir] Ensure semantic recompilation cascades to path dependencies
-  * [mix compile.elixir] Lock the compiler to avoid concurrent usage
-  * [mix format] Do not add new lines if the formatted file is empty
-  * [mix format] Properly compile dependencies on `mix format`
-  * [mix release] Only set `RELEASE_MODE` after `env.{sh,bat}` are executed
-  * [mix release] Allow application mode configuration to cascade to dependencies
-  * [mix xref] Do not emit already consolidated warnings during `mix xref trace`
-  * [Mix] Do not start apps with `runtime: false` on `Mix.install/2`
+  * [mix app.config] Do not emit false positive warnings when configured dependencies that have `runtime: false` set
+  * [mix compile.elixir] Ensure that a manifest is generated even with no source code
+  * [mix compile.elixir] Make sure export dependencies trigger recompilation when the dependency is removed as well as when the whole file is removed
+  * [mix compile.elixir] Do not emit false positive warnings when a path dependency adds a module that is then used by the current application in the same `mix compile` cycle
+  * [mix test] Ensure protocols within the current project are consolidated when `--cover` is given
+  * [mix release] Improve compliance of release scripts with stripped down Linux installations
+  * [mix release] Preserve file mode when copying non-beam ebin files
+  * [mix xref] Ensure args are passed to the underlying `mix compile` call
 
-### 3. Soft deprecations (no warnings emitted)
+### 3. Soft-deprecations (no warnings emitted)
 
 #### Elixir
 
-  * [File] Passing a callback as third argument to `File.cp/3` and `File.cp_r/3` is deprecated.
-    Instead pass the callback the `:on_conflict` key of a keyword list
+  * [Kernel] Using `first..last` to match on ranges is soft-deprecated and will warn on future Elixir versions. Use `first..last//step` instead
+  * [Kernel] Using `first..last` to create decreasing ranges is soft-deprecated and will warn on future versions. Use `first..last//-1` instead
+
+### 4. Hard-deprecations
 
 #### EEx
 
-  * [EEx] Using `<%# ... %>` for comments is deprecated. Please use `<% # ... %>` or the new multi-line comments with `<%!-- ... --%>`
-
-#### Logger
-
-  * [Logger] Deprecate `Logger.enable/1` and `Logger.disable/1` in favor of `Logger.put_process_level/2`
-
-#### Mix
-
-  * [mix cmd] The `--app` option in `mix cmd CMD` is deprecated in favor of the more efficient `mix do --app app cmd CMD`
-
-### 4. Hard deprecations
+  * [EEx.Engine] `use EEx.Engine` is deprecated in favor of explicit delegation
 
 #### Elixir
 
-  * [Application] Calling `Application.get_env/3` and friends in the module body is now discouraged, use `Application.compile_env/3` instead
-  * [Bitwise] `use Bitwise` is deprecated, use `import Bitwise` instead
-  * [Bitwise] `~~~` is deprecated in favor of `bnot` for clarity
-  * [Kernel.ParallelCompiler] Returning a list or two-element tuple from `:each_cycle` is deprecated, return a `{:compile | :runtime, modules, warnings}` tuple instead
-  * [Kernel] Deprecate the operator `<|>` to avoid ambiguity with upcoming extended numerical operators
-  * [String] Deprecate passing a binary compiled pattern to `String.starts_with?/2`
-
-#### Logger
-
-  * [Logger] Deprecate `$levelpad` on message formatting
+  * [Kernel] The binary operator `^^^` is deprecated. If you are using `Bitwise.^^^/2`, use `Bitwise.bxor/2` instead
+  * [Kernel] Deprecate `@foo()` in favor of `@foo`
+  * [System] Deprecate `System.stacktrace/0` (it was already deprecated outside of catch/rescue and now it is deprecated everywhere)
 
 #### Mix
 
-  * [Mix] `Mix.Tasks.Xref.calls/1` is deprecated in favor of compilation tracers
+  * [mix compile] The `:xref` compiler is deprecated and it has no effect. Please remove it from your mix.exs file.
 
 ### 5. Backwards incompatible changes
 
-#### Mix
+A backward incompatible change was found on Elixir v1.12.0 after the release. This was not planned and it is documented below:
 
-  * [mix local.rebar] Remove support for rebar2, which has not been updated in 5 years, and is no longer supported on recent Erlang/OTP versions
+#### ExUnit
 
-## v1.13
+  * [ExUnit.Formatter] `{:suite_finished, load_time, run_time}` message has been updated to `{:suite_finished, %{load: load_time, run: run_time, async: async_time}}`
 
-The CHANGELOG for v1.13 releases can be found [in the v1.13 branch](https://github.com/elixir-lang/elixir/blob/v1.13/CHANGELOG.md).
+## v1.11
+
+The CHANGELOG for v1.11 releases can be found [in the v1.11 branch](https://github.com/elixir-lang/elixir/blob/v1.11/CHANGELOG.md).

CODE_OF_CONDUCT.md

@@ -13,23 +13,17 @@ The goal of the Code of Conduct is to specify a baseline standard of behavior so
 These are the values Elixir developers should aspire to:
 
   * Be friendly and welcoming
-  * Be kind
+  * Be patient
     * Remember that people have varying communication styles and that not everyone is using their native language. (Meaning and tone can be lost in translation.)
-    * Interpret the arguments of others in good faith, do not seek to disagree.
-    * When we do disagree, try to understand why.
   * Be thoughtful
     * Productive communication requires effort. Think about how your words will be interpreted.
     * Remember that sometimes it is best to refrain entirely from commenting.
   * Be respectful
     * In particular, respect differences of opinion. It is important that we resolve disagreements and differing views constructively.
-  * Be constructive
-    * Avoid derailing: stay on topic; if you want to talk about something else, start a new conversation.
-    * Avoid unconstructive criticism: don't merely decry the current state of affairs; offer — or at least solicit — suggestions as to how things may be improved.
-    * Avoid harsh words and stern tone: we are all aligned towards the well-being of the community and the progress of the ecosystem. Harsh words exclude, demotivate, and lead to unnecessary conflict.
-    * Avoid snarking (pithy, unproductive, sniping comments).
-    * Avoid microaggressions (brief and commonplace verbal, behavioral and environmental indignities that communicate hostile, derogatory or negative slights and insults towards a project, person or group).
-  * Be responsible
-    * What you say and do matters. Take responsibility for your words and actions, including their consequences, whether intended or otherwise.
+  * Avoid destructive behavior
+    * Derailing: stay on topic; if you want to talk about something else, start a new conversation.
+    * Unconstructive criticism: don't merely decry the current state of affairs; offer (or at least solicit) suggestions as to how things may be improved.
+    * Snarking (pithy, unproductive, sniping comments).
 
 The following actions are explicitly forbidden:
 
@@ -47,11 +41,11 @@ Explicit enforcement of the Code of Conduct applies to the official mediums oper
 
 * The [official GitHub projects][1] and code reviews.
 * The official elixir-lang mailing lists.
-* The **[#elixir][2]** IRC channel on [Libera.Chat][3].
+* The **[#elixir-lang][2]** IRC channel on [Freenode][3].
 
 Other Elixir activities (such as conferences, meetups, and unofficial forums) are encouraged to adopt this Code of Conduct. Such groups must provide their own contact information.
 
-Project maintainers may block, remove, edit, or reject comments, commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of Conduct.
+Project maintainers may remove, edit, or reject comments, commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of Conduct.
 
 Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by emailing: elixir-lang-conduct@googlegroups.com. All complaints will be reviewed and investigated and will result in a response that is deemed necessary and appropriate to the circumstances. **All reports will be kept confidential**.
 
@@ -59,8 +53,8 @@ Instances of abusive, harassing, or otherwise unacceptable behavior may be repor
 
 ## Acknowledgements
 
-This document was based on the Code of Conduct from the Go project (dated Sep/2021) and the Contributor Covenant (v1.4).
+This document was based on the Code of Conduct from the Go project with parts derived from Django's Code of Conduct, Rust's Code of Conduct and the Contributor Covenant.
 
 [1]: https://github.com/elixir-lang/
-[2]: https://web.libera.chat/#elixir
-[3]: https://libera.chat/
+[2]: https://webchat.freenode.net/?channels=#elixir-lang
+[3]: https://www.freenode.net

Makefile

@@ -2,9 +2,8 @@ PREFIX ?= /usr/local
 TEST_FILES ?= "*_test.exs"
 SHARE_PREFIX ?= $(PREFIX)/share
 MAN_PREFIX ?= $(SHARE_PREFIX)/man
-CANONICAL := 1.14/
-CANONICAL ?= main/
-DOCS_FORMAT ?= html
+CANONICAL := 1.12/
+CANONICAL ?= master/
 ELIXIRC := bin/elixirc --ignore-module-conflict $(ELIXIRC_OPTS)
 ERLC := erlc -I lib/elixir/include
 ERL_MAKE := if [ -n "$(ERLC_OPTS)" ]; then ERL_COMPILER_OPTIONS=$(ERLC_OPTS) erl -make; else erl -make; fi
@@ -29,9 +28,9 @@ SOURCE_DATE_EPOCH_FILE = $(SOURCE_DATE_EPOCH_PATH)/SOURCE_DATE_EPOCH
 #==> Functions
 
 define CHECK_ERLANG_RELEASE
-	erl -noshell -eval '{V,_} = string:to_integer(erlang:system_info(otp_release)), io:fwrite("~s", [is_integer(V) and (V >= 23)])' -s erlang halt | grep -q '^true'; \
+	erl -noshell -eval '{V,_} = string:to_integer(erlang:system_info(otp_release)), io:fwrite("~s", [is_integer(V) and (V >= 22)])' -s erlang halt | grep -q '^true'; \
 		if [ $$? != 0 ]; then \
-		  echo "At least Erlang/OTP 23.0 is required to build Elixir"; \
+		  echo "At least Erlang/OTP 22.0 is required to build Elixir"; \
 		  exit 1; \
 		fi
 endef
@@ -93,10 +92,10 @@ $(KERNEL): lib/elixir/lib/*.ex lib/elixir/lib/*/*.ex lib/elixir/lib/*/*/*.ex
 		echo "==> bootstrap (compile)"; \
 		$(ERL) -s elixir_compiler bootstrap -s erlang halt; \
 	fi
-	$(Q) "$(MAKE)" unicode
+	$(Q) $(MAKE) unicode
 	@ echo "==> elixir (compile)";
 	$(Q) cd lib/elixir && ../../$(ELIXIRC) "lib/**/*.ex" -o ebin;
-	$(Q) "$(MAKE)" app
+	$(Q) $(MAKE) app
 
 app: $(APP)
 $(APP): lib/elixir/src/elixir.app.src lib/elixir/ebin VERSION $(GENERATE_APP)
@@ -106,7 +105,7 @@ unicode: $(UNICODE)
 $(UNICODE): lib/elixir/unicode/*
 	@ echo "==> unicode (compile)";
 	$(Q) $(ELIXIRC) lib/elixir/unicode/unicode.ex -o lib/elixir/ebin;
-	$(Q) $(ELIXIRC) lib/elixir/unicode/security.ex -o lib/elixir/ebin;
+	$(Q) $(ELIXIRC) lib/elixir/unicode/properties.ex -o lib/elixir/ebin;
 	$(Q) $(ELIXIRC) lib/elixir/unicode/tokenizer.ex -o lib/elixir/ebin;
 
 $(eval $(call APP_TEMPLATE,ex_unit,ExUnit))
@@ -128,7 +127,7 @@ install: compile
 	$(Q) for file in "$(DESTDIR)$(PREFIX)"/$(LIBDIR)/elixir/bin/*; do \
 		ln -sf "../$(LIBDIR)/elixir/bin/$${file##*/}" "$(DESTDIR)$(PREFIX)/$(BINDIR)/"; \
 	done
-	"$(MAKE)" install_man
+	$(MAKE) install_man
 
 check_reproducible: compile
 	$(Q) echo "==> Checking for reproducible builds..."
@@ -146,7 +145,7 @@ check_reproducible: compile
 	$(Q) mv lib/iex/ebin/* lib/iex/tmp/ebin_reproducible/
 	$(Q) mv lib/logger/ebin/* lib/logger/tmp/ebin_reproducible/
 	$(Q) mv lib/mix/ebin/* lib/mix/tmp/ebin_reproducible/
-	SOURCE_DATE_EPOCH=$(call READ_SOURCE_DATE_EPOCH) "$(MAKE)" compile
+	SOURCE_DATE_EPOCH=$(call READ_SOURCE_DATE_EPOCH) $(MAKE) compile
 	$(Q) echo "Diffing..."
 	$(Q) bin/elixir lib/elixir/diff.exs lib/elixir/ebin/ lib/elixir/tmp/ebin_reproducible/
 	$(Q) bin/elixir lib/elixir/diff.exs lib/eex/ebin/ lib/eex/tmp/ebin_reproducible/
@@ -160,7 +159,7 @@ clean:
 	rm -rf ebin
 	rm -rf lib/*/ebin
 	rm -rf $(PARSER)
-	$(Q) "$(MAKE)" clean_residual_files
+	$(Q) $(MAKE) clean_residual_files
 
 clean_elixir:
 	$(Q) rm -f lib/*/ebin/Elixir.*.beam
@@ -173,47 +172,55 @@ clean_residual_files:
 	rm -rf lib/mix/test/fixtures/git_rebar/
 	rm -rf lib/mix/test/fixtures/git_repo/
 	rm -rf lib/mix/test/fixtures/git_sparse_repo/
-	rm -rf lib/mix/test/fixtures/archive/ebin/
 	rm -f erl_crash.dump
-	$(Q) "$(MAKE)" clean_man
+	$(Q) $(MAKE) clean_man
 
 #==> Documentation tasks
 
 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}")
-COMPILE_DOCS = CANONICAL=$(CANONICAL) bin/elixir ../ex_doc/bin/ex_doc "$(1)" "$(VERSION)" "lib/$(2)/ebin" --main "$(3)" --source-url "https://github.com/elixir-lang/elixir" --source-ref "$(call SOURCE_REF)" $(call LOGO_PATH) --output doc/$(2) --canonical "https://hexdocs.pm/$(2)/$(CANONICAL)" --homepage-url "https://elixir-lang.org/docs.html" --formatter "$(DOCS_FORMAT)" $(4)
+
+DOCS_FORMAT = html
+DOCS_COMPILE = CANONICAL=$(CANONICAL) bin/elixir ../ex_doc/bin/ex_doc "$(1)" "$(VERSION)" "lib/$(2)/ebin" --main "$(3)" --source-url "https://github.com/elixir-lang/elixir" --source-ref "$(call SOURCE_REF)" $(call LOGO_PATH) --output doc/$(2) --canonical "https://hexdocs.pm/$(2)/$(CANONICAL)" --homepage-url "https://elixir-lang.org/docs.html" --formatter "$(DOCS_FORMAT)" $(4)
+DOCS_CONFIG = bin/elixir lib/elixir/scripts/docs_config.exs "$(1)"
 
 docs: compile ../ex_doc/bin/ex_doc docs_elixir docs_eex docs_mix docs_iex docs_ex_unit docs_logger
 
 docs_elixir: compile ../ex_doc/bin/ex_doc
 	@ echo "==> ex_doc (elixir)"
 	$(Q) rm -rf doc/elixir
-	$(call COMPILE_DOCS,Elixir,elixir,Kernel,--config "lib/elixir/docs.exs")
+	$(call DOCS_COMPILE,Elixir,elixir,Kernel,--config "lib/elixir/scripts/elixir_docs.exs")
+	$(call DOCS_CONFIG,elixir)
 
 docs_eex: compile ../ex_doc/bin/ex_doc
 	@ echo "==> ex_doc (eex)"
 	$(Q) rm -rf doc/eex
-	$(call COMPILE_DOCS,EEx,eex,EEx,--config "lib/mix/docs.exs")
+	$(call DOCS_COMPILE,EEx,eex,EEx,--config "lib/elixir/scripts/mix_docs.exs")
+	$(call DOCS_CONFIG,eex)
 
 docs_mix: compile ../ex_doc/bin/ex_doc
 	@ echo "==> ex_doc (mix)"
 	$(Q) rm -rf doc/mix
-	$(call COMPILE_DOCS,Mix,mix,Mix,--config "lib/mix/docs.exs")
+	$(call DOCS_COMPILE,Mix,mix,Mix,--config "lib/elixir/scripts/mix_docs.exs")
+	$(call DOCS_CONFIG,mix)
 
 docs_iex: compile ../ex_doc/bin/ex_doc
 	@ echo "==> ex_doc (iex)"
 	$(Q) rm -rf doc/iex
-	$(call COMPILE_DOCS,IEx,iex,IEx,--config "lib/mix/docs.exs")
+	$(call DOCS_COMPILE,IEx,iex,IEx,--config "lib/elixir/scripts/mix_docs.exs")
+	$(call DOCS_CONFIG,iex)
 
 docs_ex_unit: compile ../ex_doc/bin/ex_doc
 	@ echo "==> ex_doc (ex_unit)"
 	$(Q) rm -rf doc/ex_unit
-	$(call COMPILE_DOCS,ExUnit,ex_unit,ExUnit,--config "lib/mix/docs.exs")
+	$(call DOCS_COMPILE,ExUnit,ex_unit,ExUnit,--config "lib/elixir/scripts/mix_docs.exs")
+	$(call DOCS_CONFIG,ex_unit)
 
 docs_logger: compile ../ex_doc/bin/ex_doc
 	@ echo "==> ex_doc (logger)"
 	$(Q) rm -rf doc/logger
-	$(call COMPILE_DOCS,Logger,logger,Logger,--config "lib/mix/docs.exs")
+	$(call DOCS_COMPILE,Logger,logger,Logger,--config "lib/elixir/scripts/mix_docs.exs")
+	$(call DOCS_CONFIG,logger)
 
 ../ex_doc/bin/ex_doc:
 	@ echo "ex_doc is not found in ../ex_doc as expected. See README for more information."
@@ -231,6 +238,16 @@ Precompiled.zip: build_man compile
 	zip -9 -r Precompiled.zip bin CHANGELOG.md lib/*/ebin lib/*/lib LICENSE man NOTICE README.md VERSION
 	@ echo "Precompiled file created $(CURDIR)/Precompiled.zip"
 
+zips: Precompiled.zip Docs.zip
+	@ echo ""
+	@ echo "### Checksums"
+	@ echo ""
+	@ shasum -a 1 < Precompiled.zip | sed -e "s/-//" | xargs echo "  * Precompiled.zip SHA1:"
+	@ shasum -a 512 < Precompiled.zip | sed -e "s/-//" | xargs echo "  * Precompiled.zip SHA512:"
+	@ shasum -a 1 < Docs.zip | sed -e "s/-//" | xargs echo "  * Docs.zip SHA1:"
+	@ shasum -a 512 < Docs.zip | sed -e "s/-//" | xargs echo "  * Docs.zip SHA512:"
+	@ echo ""
+
 #==> Test tasks
 
 # If you modify this task, please update .cirrus.yml accordingly
@@ -269,7 +286,7 @@ $(TEST_EBIN)/%.beam: $(TEST_ERL)/%.erl
 	$(Q) mkdir -p $(TEST_EBIN)
 	$(Q) $(ERLC) -o $(TEST_EBIN) $<
 
-test_elixir: test_stdlib test_ex_unit test_logger test_eex test_iex test_mix
+test_elixir: test_stdlib test_ex_unit test_logger test_mix test_eex test_iex
 
 test_stdlib: compile
 	@ echo "==> elixir (ex_unit)"
@@ -287,7 +304,7 @@ PLT = .elixir.plt
 
 $(PLT):
 	@ echo "==> Building PLT with Elixir's dependencies..."
-	$(Q) dialyzer --output_plt $(PLT) --build_plt --apps erts kernel stdlib compiler syntax_tools parsetools tools ssl inets crypto runtime_tools ftp tftp mnesia public_key asn1 sasl
+	$(Q) dialyzer --output_plt $(PLT) --build_plt --apps erts kernel stdlib compiler syntax_tools parsetools tools ssl inets crypto runtime_tools ftp tftp mnesia public_key asn1 hipe sasl
 
 clean_plt:
 	$(Q) rm -f $(PLT)
@@ -326,4 +343,4 @@ install_man: build_man
 	$(Q) $(INSTALL_DATA) man/elixirc.1 $(DESTDIR)$(MAN_PREFIX)/man1
 	$(Q) $(INSTALL_DATA) man/iex.1     $(DESTDIR)$(MAN_PREFIX)/man1
 	$(Q) $(INSTALL_DATA) man/mix.1     $(DESTDIR)$(MAN_PREFIX)/man1
-	"$(MAKE)" clean_man
+	$(MAKE) clean_man

NOTICE

@@ -22,7 +22,6 @@ limitations under the License.
 == All other files
 
 Copyright 2012 Plataformatec
-Copyright 2021 The Elixir Team
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.

README.md

@@ -1,7 +1,6 @@
-<img src="https://github.com/elixir-lang/elixir-lang.github.com/raw/main/images/logo/logo.png#gh-light-mode-only" width="200" alt="Elixir">
-<img src="https://github.com/elixir-lang/elixir-lang.github.com/raw/main/images/logo/logo-dark.png#gh-dark-mode-only" width="200" alt="Elixir">
+<img src="https://github.com/elixir-lang/elixir-lang.github.com/raw/master/images/logo/logo.png" width="200" alt="Elixir">
 
-[![CI](https://github.com/elixir-lang/elixir/workflows/CI/badge.svg?branch=main)](https://github.com/elixir-lang/elixir/actions?query=branch%3Amain+workflow%3ACI) [![Build status](https://api.cirrus-ci.com/github/elixir-lang/elixir.svg?branch=main)](https://cirrus-ci.com/github/elixir-lang/elixir)
+[![CI](https://github.com/elixir-lang/elixir/workflows/CI/badge.svg?branch=master)](https://github.com/elixir-lang/elixir/actions?query=branch%3Amaster+workflow%3ACI) [![Build status](https://api.cirrus-ci.com/github/elixir-lang/elixir.svg?branch=master)](https://cirrus-ci.com/github/elixir-lang/elixir)
 
 Elixir is a dynamic, functional language designed for building scalable
 and maintainable applications.
@@ -12,14 +11,11 @@ For more about Elixir, installation and documentation,
 ## Policies
 
 New releases are announced in the [announcement mailing list][8].
-You can subscribe by sending an email to elixir-lang-ann+subscribe@googlegroups.com
-and replying to the confirmation email.
+You can subscribe by sending an email to elixir-lang-ann+subscribe@googlegroups.com and replying to the confirmation email.
 
-All security releases [will be tagged with `[security]`][10]. For more
-information, please read our [Security Policy][9].
+All security releases [will be tagged with `[security]`][10]. For more information, please read our [Security Policy][9].
 
-All interactions in our official communication channels follow our
-[Code of Conduct][1].
+All interactions in our official communication channels follow our [Code of Conduct][1].
 
 ## Bug reports
 
@@ -27,56 +23,13 @@ For reporting bugs, [visit our issue tracker][2] and follow the steps
 for reporting a new issue. **Please disclose security vulnerabilities
 privately at elixir-security@googlegroups.com**.
 
-## Issues tracker management
-
-All currently open bugs related to the Elixir repository are listed
-in the issues tracker. The Elixir team uses the issues tracker to focus
-on *actionable items*, including planned enhancements in the short- and
-medium-term. We also do our best to label entries for clarity and to ease
-collaboration.
-
-Our *actionable item policy* has some important consequences, such as:
-
-  * Proposing new features as well as request for support, help, and
-    guidance must be done in their own spaces, detailed next.
-
-  * Issues where we have identified to be outside of Elixir scope,
-    such as a bug upstream, will be closed (and requested to be moved
-    elsewhere if appropriate).
-
-  * We actively close unrelated and non-actionable issues to keep the
-    issues tracker tidy. However, we may get things wrong from time to
-    time, so we are glad to revisit issues and reopen if necessary.
-
-Keep the tone positive and be kind! For more information, see the
-[Code of Conduct][1].
-
-### Proposing new features
-
-For proposing new features, please start a discussion in the
-[Elixir Core mailing list][3]. Keep in mind that it is your responsibility
-to argue and explain why a feature is useful and how it will impact the
-codebase and the community.
-
-Once a proposal is accepted, it will be added to [the issue tracker][2].
-Features and bug fixes that have already been merged and will be included
-in the next release are then "closed" and added to the [changelog][7].
-
-### Discussions, support, and help
-
-For general discussions, support, and help, please use many of the community
-spaces [listed on the sidebar of the Elixir website](https://elixir-lang.org/),
-such as forums, chat platforms, etc, where the wider community will be available
-to help you.
-
 ## Compiling from source
 
 For the many different ways to install Elixir,
 [see our installation instructions on the website](https://elixir-lang.org/install.html).
-However, if you want to contribute to Elixir, you will need to compile from source.
+To compile from source, you can follow the steps below.
 
-First, [install Erlang](https://elixir-lang.org/install.html#installing-erlang).
-After that, clone this repository to your machine, compile and test it:
+First, [install Erlang](https://elixir-lang.org/install.html#installing-erlang). After that, clone this repository to your machine, compile and test it:
 
 ```sh
 git clone https://github.com/elixir-lang/elixir.git
@@ -88,13 +41,37 @@ make clean test
 [this article includes important notes for compiling Elixir from source
 on Windows](https://github.com/elixir-lang/elixir/wiki/Windows).
 
-In case you want to use this Elixir version as your system version,
-you need to add the `bin` directory to [your PATH environment variable](https://elixir-lang.org/install.html#setting-path-environment-variable).
-
 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 can use Interactive Elixir by running `bin/iex` in your terminal.
+
+However, if tests fail, it is likely that you have an outdated Erlang/OTP version
+(Elixir requires Erlang/OTP 22.0 or later). You can check your Erlang/OTP version
+by calling `erl` in the command line. You will see some information similar to:
+
+    Erlang/OTP 22 [erts-9.0] [smp:2:2] [async-threads:10] [kernel-poll:false]
+
+If you have properly set up your dependencies and tests still fail,
+you may want to open up a bug report, as explained next.
+
+## Proposing new features
+
+For proposing new features, please start a discussion in the
+[Elixir Core mailing list][3]. Keep in mind that it is your responsibility
+to argue and explain why a feature is useful and how it will impact the
+codebase and the community.
+
+Once a proposal is accepted, it will be added to [the issue tracker][2].
+The issue tracker focuses on *actionable items* and it holds a list of
+upcoming enhancements and pending bugs. All entries in the tracker are
+tagged for clarity and to ease collaboration.
+
+Features and bug fixes that have already been merged and will be included
+in the next release are marked as "closed" in the issue tracker and are
+added to the [changelog][7].
+
 ## Contributing
 
 We welcome everyone to contribute to Elixir. To do so, there are a few
@@ -115,7 +92,7 @@ in applications inside the `lib` folder:
 
 You can run all tests in the root directory with `make test` and you can
 also run tests for a specific framework `make test_#{APPLICATION}`, for example,
-`make test_ex_unit`. If you just changed something in Elixir's standard
+`make test_ex_unit`. If you just changed something in the Elixir's standard
 library, you can run only that portion through `make test_stdlib`.
 
 If you are changing just one file, you can choose to compile and run tests only
@@ -127,12 +104,6 @@ bin/elixirc lib/elixir/lib/string.ex -o lib/elixir/ebin
 bin/elixir lib/elixir/test/elixir/string_test.exs
 ```
 
-You can also use the `LINE` env var to run a single test:
-
-```sh
-LINE=123 bin/elixir lib/elixir/test/elixir/string_test.exs
-````
-
 To recompile (including Erlang modules):
 
 ```sh
@@ -152,7 +123,7 @@ make clean_elixir compile
 
 Similarly, if you can't get Elixir to compile or the tests to pass after
 updating an existing checkout, run `make clean compile`. You can check
-[the official build status](https://github.com/elixir-lang/elixir/actions/workflows/ci.yml).
+[the official build status on Cirrus CI](https://cirrus-ci.com/github/elixir-lang/elixir).
 More tasks can be found by reading the [Makefile](Makefile).
 
 With tests running and passing, you are ready to contribute to Elixir and
@@ -171,12 +142,12 @@ We outline our process below to clarify the roles of everyone involved.
 
 All pull requests must be approved by two committers before being merged into
 the repository. If any changes are necessary, the team will leave appropriate
-comments requesting changes to the code. Unfortunately, we cannot guarantee a
+comments requesting changes to the code. Unfortunately we cannot guarantee a
 pull request will be merged, even when modifications are requested, as the Elixir
 team will re-evaluate the contribution as it changes.
 
 Committers may also push style changes directly to your branch. If you would
-rather manage all changes yourself, you can disable the "Allow edits from maintainers"
+rather manage all changes yourself, you can disable "Allow edits from maintainers"
 feature when submitting your pull request.
 
 The Elixir team may optionally assign someone to review a pull request.
@@ -195,8 +166,8 @@ to be installed and built alongside Elixir:
 
 ```sh
 # After cloning and compiling Elixir, in its parent directory:
-git clone https://github.com/elixir-lang/ex_doc.git
-cd ex_doc && ../elixir/bin/mix do deps.get + compile
+git clone git://github.com/elixir-lang/ex_doc.git
+cd ex_doc && ../elixir/bin/mix do deps.get, compile
 ```
 
 Now go back to Elixir's root directory and run:
@@ -219,13 +190,13 @@ and `mix` under the `doc` directory. If you are planning to contribute documenta
   * [Issue tracker][2]
   * [Changelog][7]
   * [Security Policy][9]
-  * **[#elixir][4]** on [Libera.Chat][5] IRC
+  * **[#elixir-lang][4]** on [Freenode][5] IRC
 
   [1]: CODE_OF_CONDUCT.md
   [2]: https://github.com/elixir-lang/elixir/issues
   [3]: https://groups.google.com/group/elixir-lang-core
-  [4]: https://web.libera.chat/#elixir
-  [5]: https://libera.chat
+  [4]: https://webchat.freenode.net/?channels=#elixir-lang
+  [5]: https://www.freenode.net
   [6]: https://elixir-lang.org/docs.html
   [7]: CHANGELOG.md
   [8]: https://groups.google.com/group/elixir-lang-ann
@@ -234,7 +205,7 @@ and `mix` under the `doc` directory. If you are planning to contribute documenta
 
 ## License
 
-"Elixir" and the Elixir logo are registered trademarks of The Elixir Team.
+"Elixir" and the Elixir logo are copyright (c) 2012 Plataformatec.
 
 Elixir source code is released under Apache License 2.0.
 

RELEASE.md

@@ -4,19 +4,25 @@
 
 1. Ensure you are running on the oldest supported Erlang version
 
-2. Update version in /VERSION, bin/elixir and bin/elixir.bat
+2. Update version in /VERSION
 
 3. Ensure /CHANGELOG.md is updated, versioned and add the current date
 
 4. Update "Compatibility and Deprecations" if a new OTP version is supported
 
-5. Commit changes above with title "Release vVERSION", generate a new tag, and push it
+5. Commit changes above with title "Release vVERSION" and generate a new tag
 
-6. Wait until GitHub Actions publish artifacts to the draft release and the CI is green
+6. Run `make clean test` to ensure all tests pass from scratch and the CI is green
 
-7. Copy the relevant bits from /CHANGELOG.md to the GitHub release and publish it
+7. Recompile an existing project (for example, Ecto) to ensure manifests can be upgraded
 
-8. Add the release to `elixir.csv` with the minimum supported OTP version (all releases), update `erlang.csv` to the latest supported OTP version, and `_data/elixir-versions.yml` (except for RCs) files in `elixir-lang/elixir-lang.github.com`
+8. Push branch and the new tag
+
+9. Publish new zips with `make zips`, upload `Precompiled.zip` and `Docs.zip` to GitHub Releases, and include SHAs+CHANGELOG
+
+10. Add the release to `elixir.csv` (all releases), update `erlang.csv` to the precompiled OTP version, and `_data/elixir-versions.yml` (except for RCs) files in `elixir-lang/elixir-lang.github.com`
+
+11. Send an e-mail to elixir-lang-ann@googlegroups.com with title "Elixir vVERSION released". The body should be a link to the Release page on GitHub and the checksums. If it is a security release, prefix the title with the `[security]` tag
 
 ## Creating a new vMAJOR.MINOR branch
 
@@ -26,24 +32,14 @@
 
 2. Update tables in /SECURITY.md and "Compatibility and Deprecations"
 
-3. Commit "Branch out vMAJOR.MINOR"
+3. Commit "Prepare vMAJOR.MINOR for release"
 
-### Back in main
+### Back in master
 
-1. Bump /VERSION file, bin/elixir and bin/elixir.bat
+1. Bump /VERSION file
 
 2. Start new /CHANGELOG.md
 
-3. Update tables in /SECURITY.md and in "Compatibility and Deprecations"
+3. Update tables in /SECURITY.md in "Compatibility and Deprecations"
 
 4. Commit "Start vMAJOR.MINOR+1"
-
-## Changing supported Erlang/OTP versions
-
-1. Update the table in Compatibility and Deprecations
-
-2. Update `otp_release` checks in /Makefile and `/lib/elixir/src/elixir.erl`
-
-3. Update CI workflows in `/.cirrus.yml`, `/.github/workflows/ci.yml`, and `/.github/workflows/releases.yml`
-
-4. Remove `otp_release` version checks that are no longer needed

SECURITY.md

@@ -4,19 +4,20 @@
 
 Elixir applies bug fixes only to the latest minor branch. Security patches are available for the last 5 minor branches:
 
-Elixir version | Support
-:------------- | :-----------------------------
-1.14           | Bug fixes and security patches
-1.13           | Security patches only
-1.12           | Security patches only
-1.11           | Security patches only
-1.10           | Security patches only
+| Elixir version | Support
+| -------------- | ------------------------------
+| 1.12           | Bug fixes and security patches
+| 1.11           | Security patches only
+| 1.10           | Security patches only
+| 1.9            | Security patches only
+| 1.8            | Security patches only
+| 1.7            | Security patches only
 
 ## Announcements
 
 New releases are announced in the read-only [announcements mailing list](https://groups.google.com/group/elixir-lang-ann). You can subscribe by sending an email to elixir-lang-ann+subscribe@googlegroups.com and replying to the confirmation email.
 
-Security notifications [will be tagged with `[security]`](https://groups.google.com/forum/#!searchin/elixir-lang-ann/%5Bsecurity%5D%7Csort:date).
+All security releases [will be tagged with `[security]`](https://groups.google.com/forum/#!searchin/elixir-lang-ann/%5Bsecurity%5D%7Csort:date).
 
 ## Reporting a vulnerability
 

VERSION

@@ -1 +1 @@
-1.14.2
+1.12.3

bin/elixir

@@ -1,22 +1,20 @@
 #!/bin/sh
 set -e
 
-ELIXIR_VERSION=1.14.2
-
-if [ $# -eq 0 ] || { [ $# -eq 1 ] && { [ "$1" = "--help" ] || [ "$1" = "-h" ]; }; }; then
+if [ $# -eq 0 ] || [ "$1" = "--help" ] || [ "$1" = "-h" ]; then
   cat <<USAGE >&2
 Usage: $(basename "$0") [options] [.exs file] [data]
 
 ## General options
 
   -e "COMMAND"                 Evaluates the given command (*)
-  -h, --help                   Prints this message (standalone)
+  -h, --help                   Prints this message and exits
   -r "FILE"                    Requires the given files/patterns (*)
-  -S SCRIPT                    Finds and executes the given script in \$PATH
+  -S SCRIPT                    Finds and executes the given script in \$PATH
   -pr "FILE"                   Requires the given files/patterns in parallel (*)
   -pa "PATH"                   Prepends the given path to Erlang code path (*)
   -pz "PATH"                   Appends the given path to Erlang code path (*)
-  -v, --version                Prints Erlang/OTP and Elixir versions (standalone)
+  -v, --version                Prints Elixir version and exits
 
   --app APP                    Starts the given app and its dependencies (*)
   --erl "SWITCHES"             Switches to be passed down to Erlang (*)
@@ -24,7 +22,6 @@ Usage: $(basename "$0") [options] [.exs file] [data]
   --logger-otp-reports BOOL    Enables or disables OTP reporting
   --logger-sasl-reports BOOL   Enables or disables SASL reporting
   --no-halt                    Does not halt the Erlang VM after execution
-  --short-version              Prints Elixir version (standalone)
   --werl                       Uses Erlang's Windows shell GUI (Windows only)
 
 Options given after the .exs file or -- are passed down to the executed code.
@@ -55,7 +52,6 @@ It will attempt to create PIPEDIR and LOGDIR if they don't exist.
 See run_erl to learn more. To reattach, run: to_erl PIPEDIR.
 
 ** Options marked with (*) can be given more than once.
-** Standalone options can't be combined with other options.
 USAGE
   exit 1
 fi
@@ -70,11 +66,6 @@ readlink_f () {
   fi
 }
 
-if [ $# -eq 1 ] && [ "$1" = "--short-version" ]; then
-  echo "$ELIXIR_VERSION"
-  exit 0
-fi
-
 # Stores static Erlang arguments and --erl (which is passed as is)
 ERL=""
 
@@ -100,29 +91,32 @@ LENGTH=$#
 set -- "$@" -extra
 
 while [ $I -le $LENGTH ]; do
-  # S counts to be shifted, C counts to be copied
-  S=0
-  C=0
+  S=1
   case "$1" in
     +iex)
-        C=1
+        set -- "$@" "$1"
         MODE="iex"
         ;;
     +elixirc)
-        C=1
+        set -- "$@" "$1"
         MODE="elixirc"
         ;;
-    -v|--no-halt|--no-pry)
-        C=1
+    -v|--no-halt)
+        set -- "$@" "$1"
         ;;
     -e|-r|-pr|-pa|-pz|--app|--eval|--remsh|--dot-iex)
-        C=2
+        S=2
+        set -- "$@" "$1" "$2"
         ;;
     --rpc-eval)
-        C=3
+        S=3
+        set -- "$@" "$1" "$2" "$3"
+        ;;
+    --detached)
+        echo "warning: the --detached option is deprecated" >&2
+        ERL="$ERL -detached"
         ;;
     --hidden)
-        S=1
         ERL="$ERL -hidden"
         ;;
     --logger-otp-reports)
@@ -183,7 +177,6 @@ while [ $I -le $LENGTH ]; do
         fi
         ;;
     --werl)
-        S=1
         if [ "$OS" = "Windows_NT" ]; then ERL_EXEC="werl"; fi
         ;;
     *)
@@ -196,13 +189,6 @@ while [ $I -le $LENGTH ]; do
         ;;
   esac
 
-  while [ $I -le $LENGTH ] && [ $C -gt 0 ]; do
-    C=$((C - 1))
-    I=$((I + 1))
-    set -- "$@" "$1"
-    shift
-  done
-
   I=$((I + S))
   shift $S
 done
@@ -224,11 +210,7 @@ if [ "$OS" != "Windows_NT" ] && [ -z "$NO_COLOR" ]; then
   if test -t 1 -a -t 2; then ERL="-elixir ansi_enabled true $ERL"; fi
 fi
 
-# One MAY change ERTS_BIN= but you MUST NOT change
-# ERTS_BIN=$ERTS_BIN as it is handled by Elixir releases.
 ERTS_BIN=
-ERTS_BIN="$ERTS_BIN"
-
 set -- "$ERTS_BIN$ERL_EXEC" -pa "$SCRIPT_PATH"/../lib/*/ebin $ELIXIR_ERL_OPTIONS $ERL "$@"
 
 if [ -n "$RUN_ERL_PIPE" ]; then

bin/elixir.bat

@@ -1,14 +1,10 @@
 @if defined ELIXIR_CLI_ECHO (@echo on) else (@echo off)
-
-set ELIXIR_VERSION=1.14.2
-
 setlocal enabledelayedexpansion
-if    ""%1""==""""                if ""%2""=="""" goto documentation
-if /I ""%1""==""--help""          if ""%2""=="""" goto documentation
-if /I ""%1""==""-h""              if ""%2""=="""" goto documentation
-if /I ""%1""==""/h""              if ""%2""=="""" goto documentation
-if    ""%1""==""/?""              if ""%2""=="""" goto documentation
-if /I ""%1""==""--short-version"" if ""%2""=="""" goto shortversion
+if    ""%1""==""""       goto documentation
+if /I ""%1""==""--help"" goto documentation
+if /I ""%1""==""-h""     goto documentation
+if /I ""%1""==""/h""     goto documentation
+if    ""%1""==""/?""     goto documentation
 goto parseopts
 
 :documentation
@@ -17,13 +13,13 @@ echo.
 echo ## General options
 echo.
 echo   -e "COMMAND"                 Evaluates the given command (*)
-echo   -h, --help                   Prints this message (standalone)
+echo   -h, --help                   Prints this message and exits
 echo   -r "FILE"                    Requires the given files/patterns (*)
 echo   -S SCRIPT                    Finds and executes the given script in $PATH
 echo   -pr "FILE"                   Requires the given files/patterns in parallel (*)
 echo   -pa "PATH"                   Prepends the given path to Erlang code path (*)
 echo   -pz "PATH"                   Appends the given path to Erlang code path (*)
-echo   -v, --version                Prints Erlang/OTP and Elixir versions (standalone)
+echo   -v, --version                Prints Elixir version and exits
 echo.
 echo   --app APP                    Starts the given app and its dependencies (*)
 echo   --erl "SWITCHES"             Switches to be passed down to Erlang (*)
@@ -31,7 +27,6 @@ echo   --eval "COMMAND"             Evaluates the given command, same as -e (*)
 echo   --logger-otp-reports BOOL    Enables or disables OTP reporting
 echo   --logger-sasl-reports BOOL   Enables or disables SASL reporting
 echo   --no-halt                    Does not halt the Erlang VM after execution
-echo   --short-version              Prints Elixir version (standalone)
 echo   --werl                       Uses Erlang's Windows shell GUI (Windows only)
 echo.
 echo Options given after the .exs file or -- are passed down to the executed code.
@@ -59,11 +54,6 @@ echo.
 echo --pipe-to is not supported on Windows. If set, Elixir won't boot.
 echo.
 echo ** Options marked with (*) can be given more than once.
-echo ** Standalone options can't be combined with other options.
-goto end
-
-:shortversion
-echo !ELIXIR_VERSION!
 goto end
 
 :parseopts
@@ -88,7 +78,6 @@ set SCRIPT_PATH=%~dp0
 
 rem Designates the path to the ERTS system
 set ERTS_BIN=
-set ERTS_BIN=!ERTS_BIN!
 
 rem Recursive loop called for each parameter that parses the cmd line parameters
 :startloop
@@ -136,12 +125,10 @@ if ""==!par:-pr=!         (set "parsElixir=!parsElixir! -pr %1" && shift && goto
 if ""==!par:-pa=!         (set "parsElixir=!parsElixir! -pa %1" && shift && goto startloop)
 if ""==!par:-pz=!         (set "parsElixir=!parsElixir! -pz %1" && shift && goto startloop)
 if ""==!par:-v=!          (set "parsElixir=!parsElixir! -v" && goto startloop)
-if ""==!par:--version=!   (set "parsElixir=!parsElixir! --version" && goto startloop)
 if ""==!par:--app=!       (set "parsElixir=!parsElixir! --app %1" && shift && goto startloop)
 if ""==!par:--no-halt=!   (set "parsElixir=!parsElixir! --no-halt" && goto startloop)
 if ""==!par:--remsh=!     (set "parsElixir=!parsElixir! --remsh %1" && shift && goto startloop)
 if ""==!par:--dot-iex=!   (set "parsElixir=!parsElixir! --dot-iex %1" && shift && goto startloop)
-if ""==!par:--no-pry=!    (set "parsElixir=!parsElixir! --no-pry" && goto startloop)
 rem ******* ERLANG PARAMETERS **********************
 if ""==!par:--boot=!                (set "parsErlang=!parsErlang! -boot %1" && shift && goto startloop)
 if ""==!par:--boot-var=!            (set "parsErlang=!parsErlang! -boot_var %1 %2" && shift && shift && goto startloop)
@@ -175,19 +162,10 @@ if %errorlevel% == 0 (
 if not !runMode! == "iex" (
   set beforeExtra=-noshell -s elixir start_cli !beforeExtra!
 )
-if defined ELIXIR_CLI_DRY_RUN (
-   if defined useWerl (
-     echo start "" "!ERTS_BIN!werl.exe" !ext_libs! !ELIXIR_ERL_OPTIONS! !parsErlang! !beforeExtra! -extra !parsElixir!
-   ) else (
-     echo "!ERTS_BIN!erl.exe" !ext_libs! !ELIXIR_ERL_OPTIONS! !parsErlang! !beforeExtra! -extra !parsElixir!
-   )
+if defined useWerl (
+  start "" "!ERTS_BIN!werl.exe" !ext_libs! !ELIXIR_ERL_OPTIONS! !parsErlang! !beforeExtra! -extra !parsElixir!
 ) else (
-  if defined useWerl (
-    start "" "!ERTS_BIN!werl.exe" !ext_libs! !ELIXIR_ERL_OPTIONS! !parsErlang! !beforeExtra! -extra !parsElixir!
-  ) else (
-    "!ERTS_BIN!erl.exe" !ext_libs! !ELIXIR_ERL_OPTIONS! !parsErlang! !beforeExtra! -extra !parsElixir!
-  )
+  "!ERTS_BIN!erl.exe" !ext_libs! !ELIXIR_ERL_OPTIONS! !parsErlang! !beforeExtra! -extra !parsElixir!
 )
-exit /B %ERRORLEVEL%
 :end
-endlocal
+endlocal

bin/elixirc

@@ -7,7 +7,7 @@ Usage: $(basename "$0") [elixir switches] [compiler switches] [.ex files]
 
   -h, --help                Prints this message and exits
   -o                        The directory to output compiled files
-  -v, --version             Prints Elixir version and exits (standalone)
+  -v, --version             Prints Elixir version and exits
 
   --ignore-module-conflict  Does not emit warnings if a module was previously defined
   --no-debug-info           Does not attach debug info to compiled modules

bin/elixirc.bat

@@ -16,7 +16,7 @@ echo Usage: %~nx0 [elixir switches] [compiler switches] [.ex files]
 echo.
 echo   -h, --help                Prints this message and exits
 echo   -o                        The directory to output compiled files
-echo   -v, --version             Prints Elixir version and exits (standalone)
+echo   -v, --version             Prints Elixir version and exits
 echo.
 echo   --ignore-module-conflict  Does not emit warnings if a module was previously defined
 echo   --no-debug-info           Does not attach debug info to compiled modules

bin/iex

@@ -7,11 +7,9 @@ Usage: $(basename "$0") [options] [.exs file] [data]
 
 The following options are exclusive to IEx:
 
-  --dot-iex "FILE"    Evaluates FILE, line by line, to set up IEx' environment.
-                      Defaults to evaluating .iex.exs or ~/.iex.exs, if any exists.
-                      If FILE is empty, then no file will be loaded.
-  --remsh NAME        Connects to a node using a remote shell.
-  --no-pry            Doesn't start pry sessions when dbg/2 is called.
+  --dot-iex "PATH"    Overrides default .iex.exs file and uses path instead;
+                      path can be empty, then no file will be loaded
+  --remsh NAME        Connects to a node using a remote shell
 
 It accepts all other options listed by "elixir --help".
 USAGE

bin/iex.bat

@@ -11,19 +11,17 @@ echo Usage: %~nx0 [options] [.exs file] [data]
 echo.
 echo The following options are exclusive to IEx:
 echo.
-echo   --dot-iex "FILE"    Evaluates FILE, line by line, to set up IEx' environment.
-echo                       Defaults to evaluating .iex.exs or ~/.iex.exs, if any exists.
-echo                       If FILE is empty, then no file will be loaded.
+echo   --dot-iex "PATH"    Overrides default .iex.exs file and uses path instead;
+echo                       path can be empty, then no file will be loaded
 echo   --remsh NAME        Connects to a node using a remote shell
 echo   --werl              Uses Erlang's Windows shell GUI (Windows only)
-echo   --no-pry            Doesn't start pry sessions when dbg/2 is called.
 echo.
 echo Set the IEX_WITH_WERL environment variable to always use werl.
 echo It accepts all other options listed by "elixir --help".
 goto end
 
 :run
-if defined IEX_WITH_WERL (set __ELIXIR_IEX_FLAGS=--werl) else (set __ELIXIR_IEX_FLAGS=)
+if defined IEX_WITH_WERL (@set __ELIXIR_IEX_FLAGS=--werl) else (set __ELIXIR_IEX_FLAGS=)
 call "%~dp0\elixir.bat" --no-halt --erl "-noshell -user Elixir.IEx.CLI" +iex %__ELIXIR_IEX_FLAGS% %*
 :end
 endlocal

lib/eex/lib/eex.ex

@@ -9,14 +9,14 @@ end
 
 defmodule EEx do
   @moduledoc ~S"""
-  EEx stands for Embedded Elixir.
-
-  Embedded Elixir allows you to embed Elixir code inside a string
-  in a robust way.
+  EEx stands for Embedded Elixir. It allows you to embed
+  Elixir code inside a string in a robust way.
 
       iex> EEx.eval_string("foo <%= bar %>", bar: "baz")
       "foo baz"
 
+  ## API
+
   This module provides three main APIs for you to use:
 
     1. Evaluate a string (`eval_string/3`) or a file (`eval_file/3`)
@@ -34,49 +34,21 @@ defmodule EEx do
        above and is available to you if you want to provide your own
        ways of handling the compiled template.
 
-  The APIs above support several options, documented below. You may
-  also pass an engine which customizes how the EEx code is compiled.
-
   ## Options
 
-  All functions in this module, unless otherwise noted, accept EEx-related
-  options. They are:
+  All functions in this module accept EEx-related options.
+  They are:
 
     * `: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`.
-
     * `:indentation` - (since v1.11.0) an integer added to the column after every
       new line. Defaults to `0`.
-
     * `:engine` - the EEx engine to be used for compilation.
-
     * `:trim` - if `true`, trims whitespace left and right of quotation as
       long as at least one newline is present. All subsequent newlines and
       spaces are removed but one newline is retained. Defaults to `false`.
 
-    * `:parser_options` - (since: 1.13.0) allow customizing the parsed code
-      that is generated. See `Code.string_to_quoted/2` for available options.
-      Note that the options `:file`, `:line` and `:column` are ignored if
-      passed in. Defaults to `Code.get_compiler_option(:parser_options)`
-      (which defaults to `[]` if not set).
-
-  ## Tags
-
-  EEx supports multiple tags, declared below:
-
-      <% Elixir expression: executes code but discards output %>
-      <%= Elixir expression: executes code and prints result %>
-      <%% EEx quotation: returns the contents inside the tag as is %>
-      <%!-- Comments: they are discarded from source --%>
-
-  EEx supports additional tags, that may be used by some engines,
-  but they do not have a meaning by default:
-
-      <%| ... %>
-      <%/ ... %>
-
   ## Engine
 
   EEx has the concept of engines which allows you to modify or
@@ -85,10 +57,42 @@ defmodule EEx do
   By default, `EEx` uses the `EEx.SmartEngine` that provides some
   conveniences on top of the simple `EEx.Engine`.
 
-  ### `EEx.SmartEngine`
+  ### Tags
 
-  The smart engine uses EEx default rules and adds the `@` construct
-  for reading template assigns:
+  `EEx.SmartEngine` supports the following tags:
+
+      <% Elixir expression - inline with output %>
+      <%= Elixir expression - replace with result %>
+      <%% EEx quotation - returns the contents inside %>
+      <%# Comments - they are discarded from source %>
+
+  All expressions that output something to the template
+  **must** use the equals sign (`=`). Since everything in
+  Elixir is an expression, there are no exceptions for this rule.
+  For example, while some template languages would special-case
+  `if` clauses, they are treated the same in EEx and
+  also require `=` in order to have their result printed:
+
+      <%= if true do %>
+        It is obviously true
+      <% else %>
+        This will never appear
+      <% end %>
+
+  To escape an EEx expression in EEx use `<%% content %>`. For example:
+
+      <%%= x + 3 %>
+
+  will be rendered as `<%= x + 3 %>`.
+
+  Note that different engines may have different rules
+  for each tag. Other tags may be added in future versions.
+
+  ### Macros
+
+  `EEx.SmartEngine` also adds some macros to your template.
+  An example is the `@` macro which allows easy data access
+  in a template:
 
       iex> EEx.eval_string("<%= @foo %>", assigns: [foo: 1])
       "1"
@@ -101,16 +105,6 @@ defmodule EEx do
   required by the template is not specified at compilation time.
   """
 
-  @type line :: non_neg_integer
-  @type column :: non_neg_integer
-  @type marker :: '=' | '/' | '|' | ''
-  @type metadata :: %{column: column, line: line}
-  @type token ::
-          {:comment, charlist, metadata}
-          | {:text, charlist, metadata}
-          | {:expr | :start_expr | :middle_expr | :end_expr, marker, charlist, metadata}
-          | {:eof, metadata}
-
   @doc """
   Generates a function definition from the given string.
 
@@ -118,9 +112,7 @@ defmodule EEx do
   The `name` argument is the name that the generated function will have.
   `template` is the string containing the EEx template. `args` is a list of arguments
   that the generated function will accept. They will be available inside the EEx
-  template.
-
-  The supported `options` are described [in the module docs](#module-options).
+  template. `options` is a list of EEx compilation options (see the module documentation).
 
   ## Examples
 
@@ -152,13 +144,11 @@ defmodule EEx do
   The `name` argument is the name that the generated function will have.
   `file` is the path to the EEx template file. `args` is a list of arguments
   that the generated function will accept. They will be available inside the EEx
-  template.
+  template. `options` is a list of EEx compilation options (see the module documentation).
 
   This function is useful in case you have templates but
   you want to precompile inside a module for speed.
 
-  The supported `options` are described [in the module docs](#module-options).
-
   ## Examples
 
       # sample.eex
@@ -203,8 +193,6 @@ defmodule EEx do
   will use the `a` and `b` variables in the context where it's evaluated. See
   examples below.
 
-  The supported `options` are described [in the module docs](#module-options).
-
   ## Examples
 
       iex> quoted = EEx.compile_string("<%= a + b %>")
@@ -215,14 +203,7 @@ defmodule EEx do
   """
   @spec compile_string(String.t(), keyword) :: Macro.t()
   def compile_string(source, options \\ []) when is_binary(source) and is_list(options) do
-    case tokenize(source, options) do
-      {:ok, tokens} ->
-        EEx.Compiler.compile(tokens, options)
-
-      {:error, message, %{column: column, line: line}} ->
-        file = options[:file] || "nofile"
-        raise EEx.SyntaxError, file: file, line: line, column: column, message: message
-    end
+    EEx.Compiler.compile(source, options)
   end
 
   @doc """
@@ -238,8 +219,6 @@ defmodule EEx do
   will use the `a` and `b` variables in the context where it's evaluated. See
   examples below.
 
-  The supported `options` are described [in the module docs](#module-options).
-
   ## Examples
 
       # sample.eex
@@ -262,8 +241,6 @@ defmodule EEx do
   @doc """
   Gets a string `source` and evaluate the values using the `bindings`.
 
-  The supported `options` are described [in the module docs](#module-options).
-
   ## Examples
 
       iex> EEx.eval_string("foo <%= bar %>", bar: "baz")
@@ -280,8 +257,6 @@ defmodule EEx do
   @doc """
   Gets a `filename` and evaluate the values using the `bindings`.
 
-  The supported `options` are described [in the module docs](#module-options).
-
   ## Examples
 
       # sample.eex
@@ -301,43 +276,6 @@ defmodule EEx do
     do_eval(compiled, bindings, options)
   end
 
-  @doc """
-  Tokenize the given contents according to the given options.
-
-  ## Options
-
-    * `:line` - An integer to start as line. Default is 1.
-    * `:column` - An integer to start as column. Default is 1.
-    * `:indentation` - An integer that indicates the indentation. Default is 0.
-    * `:trim` - Tells the tokenizer to either trim the content or not. Default is false.
-    * `:file` - Can be either a file or a string "nofile".
-
-  ## Examples
-
-      iex> EEx.tokenize('foo', line: 1, column: 1)
-      {:ok, [{:text, 'foo', %{column: 1, line: 1}}, {:eof, %{column: 4, line: 1}}]}
-
-  ## Result
-
-  It returns `{:ok, [token]}` where a token is one of:
-
-    * `{:text, content, %{column: column, line: line}}`
-    * `{:expr, marker, content, %{column: column, line: line}}`
-    * `{:start_expr, marker, content, %{column: column, line: line}}`
-    * `{:middle_expr, marker, content, %{column: column, line: line}}`
-    * `{:end_expr, marker, content, %{column: column, line: line}}`
-    * `{:eof, %{column: column, line: line}}`
-
-  Or `{:error, message, %{column: column, line: line}}` in case of errors.
-  Note new tokens may be added in the future.
-  """
-  @doc since: "1.14.0"
-  @spec tokenize(IO.chardata(), opts :: keyword) ::
-          {:ok, [token()]} | {:error, String.t(), metadata()}
-  def tokenize(contents, opts \\ []) do
-    EEx.Compiler.tokenize(contents, opts)
-  end
-
   ### Helpers
 
   defp do_eval(compiled, bindings, options) do

lib/eex/lib/eex/compiler.ex

@@ -3,345 +3,78 @@ defmodule EEx.Compiler do
 
   # When changing this setting, don't forget to update the docs for EEx
   @default_engine EEx.SmartEngine
-  @h_spaces [?\s, ?\t]
-  @all_spaces [?\s, ?\t, ?\n, ?\r]
-
-  @doc """
-  Tokenize EEx contents.
-  """
-  def tokenize(contents, opts) when is_binary(contents) do
-    tokenize(String.to_charlist(contents), opts)
-  end
-
-  def tokenize(contents, opts) when is_list(contents) do
-    file = opts[:file] || "nofile"
-    line = opts[:line] || 1
-    trim = opts[:trim] || false
-    indentation = opts[:indentation] || 0
-    column = indentation + (opts[:column] || 1)
-
-    state = %{trim: trim, indentation: indentation, file: file}
-
-    {contents, line, column} =
-      (trim && trim_init(contents, line, column, state)) || {contents, line, column}
-
-    tokenize(contents, line, column, state, [{line, column}], [])
-  end
-
-  defp tokenize('<%%' ++ t, line, column, state, buffer, acc) do
-    tokenize(t, line, column + 3, state, [?%, ?< | buffer], acc)
-  end
-
-  defp tokenize('<%!--' ++ t, line, column, state, buffer, acc) do
-    case comment(t, line, column + 5, state, []) do
-      {:error, line, column, message} ->
-        {:error, message, %{line: line, column: column}}
-
-      {:ok, new_line, new_column, rest, comments} ->
-        token = {:comment, Enum.reverse(comments), %{line: line, column: column}}
-        trim_and_tokenize(rest, new_line, new_column, state, buffer, acc, &[token | &1])
-    end
-  end
-
-  # TODO: Deprecate this on Elixir v1.18
-  defp tokenize('<%#' ++ t, line, column, state, buffer, acc) do
-    case expr(t, line, column + 3, state, []) do
-      {:error, line, column, message} ->
-        {:error, message, %{line: line, column: column}}
-
-      {:ok, _, new_line, new_column, rest} ->
-        trim_and_tokenize(rest, new_line, new_column, state, buffer, acc, & &1)
-    end
-  end
-
-  defp tokenize('<%' ++ t, line, column, state, buffer, acc) do
-    {marker, t} = retrieve_marker(t)
-
-    case expr(t, line, column + 2 + length(marker), state, []) do
-      {:error, line, column, message} ->
-        {:error, message, %{line: line, column: column}}
-
-      {:ok, expr, new_line, new_column, rest} ->
-        {key, expr} =
-          case :elixir_tokenizer.tokenize(expr, 1, file: "eex", check_terminators: false) do
-            {:ok, _line, _column, warnings, tokens} ->
-              Enum.each(Enum.reverse(warnings), fn {location, file, msg} ->
-                :elixir_errors.erl_warn(location, file, msg)
-              end)
-
-              token_key(tokens, expr)
-
-            {:error, _, _, _, _} ->
-              {:expr, expr}
-          end
-
-        marker =
-          if key in [:middle_expr, :end_expr] and marker != '' do
-            message =
-              "unexpected beginning of EEx tag \"<%#{marker}\" on \"<%#{marker}#{expr}%>\", " <>
-                "please remove \"#{marker}\""
-
-            :elixir_errors.erl_warn({line, column}, state.file, message)
-            ''
-          else
-            marker
-          end
-
-        token = {key, marker, expr, %{line: line, column: column}}
-        trim_and_tokenize(rest, new_line, new_column, state, buffer, acc, &[token | &1])
-    end
-  end
-
-  defp tokenize('\n' ++ t, line, _column, state, buffer, acc) do
-    tokenize(t, line + 1, state.indentation + 1, state, [?\n | buffer], acc)
-  end
-
-  defp tokenize([h | t], line, column, state, buffer, acc) do
-    tokenize(t, line, column + 1, state, [h | buffer], acc)
-  end
-
-  defp tokenize([], line, column, _state, buffer, acc) do
-    eof = {:eof, %{line: line, column: column}}
-    {:ok, Enum.reverse([eof | tokenize_text(buffer, acc)])}
-  end
-
-  defp trim_and_tokenize(rest, line, column, state, buffer, acc, fun) do
-    {rest, line, column, buffer} = trim_if_needed(rest, line, column, state, buffer)
-
-    acc = tokenize_text(buffer, acc)
-    tokenize(rest, line, column, state, [{line, column}], fun.(acc))
-  end
-
-  # Retrieve marker for <%
-
-  defp retrieve_marker([marker | t]) when marker in [?=, ?/, ?|] do
-    {[marker], t}
-  end
-
-  defp retrieve_marker(t) do
-    {'', t}
-  end
-
-  # Tokenize a multi-line comment until we find --%>
-
-  defp comment([?-, ?-, ?%, ?> | t], line, column, _state, buffer) do
-    {:ok, line, column + 4, t, buffer}
-  end
-
-  defp comment('\n' ++ t, line, _column, state, buffer) do
-    comment(t, line + 1, state.indentation + 1, state, '\n' ++ buffer)
-  end
-
-  defp comment([head | t], line, column, state, buffer) do
-    comment(t, line, column + 1, state, [head | buffer])
-  end
-
-  defp comment([], line, column, _state, _buffer) do
-    {:error, line, column, "missing token '--%>'"}
-  end
-
-  # Tokenize an expression until we find %>
-
-  defp expr([?%, ?> | t], line, column, _state, buffer) do
-    {:ok, Enum.reverse(buffer), line, column + 2, t}
-  end
-
-  defp expr('\n' ++ t, line, _column, state, buffer) do
-    expr(t, line + 1, state.indentation + 1, state, [?\n | buffer])
-  end
-
-  defp expr([h | t], line, column, state, buffer) do
-    expr(t, line, column + 1, state, [h | buffer])
-  end
-
-  defp expr([], line, column, _state, _buffer) do
-    {:error, line, column, "missing token '%>'"}
-  end
-
-  # Receives tokens and check if it is a start, middle or an end token.
-  defp token_key(tokens, expr) do
-    case {tokens, tokens |> Enum.reverse() |> drop_eol()} do
-      {[{:end, _} | _], [{:do, _} | _]} ->
-        {:middle_expr, expr}
-
-      {_, [{:do, _} | _]} ->
-        {:start_expr, maybe_append_space(expr)}
-
-      {_, [{:block_identifier, _, _} | _]} ->
-        {:middle_expr, maybe_append_space(expr)}
-
-      {[{:end, _} | _], [{:stab_op, _, _} | _]} ->
-        {:middle_expr, expr}
-
-      {_, [{:stab_op, _, _} | reverse_tokens]} ->
-        fn_index = Enum.find_index(reverse_tokens, &match?({:fn, _}, &1)) || :infinity
-        end_index = Enum.find_index(reverse_tokens, &match?({:end, _}, &1)) || :infinity
-
-        if end_index > fn_index do
-          {:start_expr, expr}
-        else
-          {:middle_expr, expr}
-        end
-
-      {tokens, _} ->
-        case Enum.drop_while(tokens, &closing_bracket?/1) do
-          [{:end, _} | _] -> {:end_expr, expr}
-          _ -> {:expr, expr}
-        end
-    end
-  end
-
-  defp drop_eol([{:eol, _} | rest]), do: drop_eol(rest)
-  defp drop_eol(rest), do: rest
-
-  defp maybe_append_space([?\s]), do: [?\s]
-  defp maybe_append_space([h]), do: [h, ?\s]
-  defp maybe_append_space([h | t]), do: [h | maybe_append_space(t)]
-
-  defp closing_bracket?({closing, _}) when closing in ~w"( [ {"a, do: true
-  defp closing_bracket?(_), do: false
-
-  # Tokenize the buffered text by appending
-  # it to the given accumulator.
-
-  defp tokenize_text([{_line, _column}], acc) do
-    acc
-  end
-
-  defp tokenize_text(buffer, acc) do
-    [{line, column} | buffer] = Enum.reverse(buffer)
-    [{:text, buffer, %{line: line, column: column}} | acc]
-  end
-
-  ## Trim
-
-  defp trim_if_needed(rest, line, column, state, buffer) do
-    if state.trim do
-      buffer = trim_left(buffer, 0)
-      {rest, line, column} = trim_right(rest, line, column, 0, state)
-      {rest, line, column, buffer}
-    else
-      {rest, line, column, buffer}
-    end
-  end
-
-  defp trim_init([h | t], line, column, state) when h in @h_spaces,
-    do: trim_init(t, line, column + 1, state)
-
-  defp trim_init([?\r, ?\n | t], line, _column, state),
-    do: trim_init(t, line + 1, state.indentation + 1, state)
-
-  defp trim_init([?\n | t], line, _column, state),
-    do: trim_init(t, line + 1, state.indentation + 1, state)
-
-  defp trim_init([?<, ?% | _] = rest, line, column, _state),
-    do: {rest, line, column}
-
-  defp trim_init(_, _, _, _), do: false
-
-  defp trim_left(buffer, count) do
-    case trim_whitespace(buffer, 0) do
-      {[?\n, ?\r | rest], _} -> trim_left(rest, count + 1)
-      {[?\n | rest], _} -> trim_left(rest, count + 1)
-      _ when count > 0 -> [?\n | buffer]
-      _ -> buffer
-    end
-  end
-
-  defp trim_right(rest, line, column, last_column, state) do
-    case trim_whitespace(rest, column) do
-      {[?\r, ?\n | rest], column} ->
-        trim_right(rest, line + 1, state.indentation + 1, column + 1, state)
-
-      {[?\n | rest], column} ->
-        trim_right(rest, line + 1, state.indentation + 1, column, state)
-
-      {[], column} ->
-        {[], line, column}
-
-      _ when last_column > 0 ->
-        {[?\n | rest], line - 1, last_column}
-
-      _ ->
-        {rest, line, column}
-    end
-  end
-
-  defp trim_whitespace([h | t], column) when h in @h_spaces, do: trim_whitespace(t, column + 1)
-  defp trim_whitespace(list, column), do: {list, column}
 
   @doc """
   This is the compilation entry point. It glues the tokenizer
   and the engine together by handling the tokens and invoking
   the engine every time a full expression or text is received.
   """
-  @spec compile([EEx.token()], keyword) :: Macro.t()
-  def compile(tokens, opts) do
+  @spec compile(String.t(), keyword) :: Macro.t()
+  def compile(source, opts) when is_binary(source) and is_list(opts) do
     file = opts[:file] || "nofile"
     line = opts[:line] || 1
-    parser_options = opts[:parser_options] || Code.get_compiler_option(:parser_options)
-    engine = opts[:engine] || @default_engine
+    column = 1
+    indentation = opts[:indentation] || 0
+    trim = opts[:trim] || false
+    tokenizer_options = %{trim: trim, indentation: indentation}
 
-    state = %{
-      engine: engine,
-      file: file,
-      line: line,
-      quoted: [],
-      start_line: nil,
-      start_column: nil,
-      parser_options: parser_options
-    }
+    case EEx.Tokenizer.tokenize(source, line, column, tokenizer_options) do
+      {:ok, tokens} ->
+        state = %{
+          engine: opts[:engine] || @default_engine,
+          file: file,
+          line: line,
+          quoted: [],
+          start_line: nil,
+          start_column: nil,
+          parser_options: Code.get_compiler_option(:parser_options)
+        }
 
-    init = state.engine.init(opts)
-    generate_buffer(tokens, init, [], state)
-  end
+        init = state.engine.init(opts)
+        generate_buffer(tokens, init, [], state)
 
-  # Ignore tokens related to comment.
-  defp generate_buffer([{:comment, _chars, _meta} | rest], buffer, scope, state) do
-    generate_buffer(rest, buffer, scope, state)
+      {:error, line, column, message} ->
+        raise EEx.SyntaxError, file: file, line: line, column: column, message: message
+    end
   end
 
   # Generates the buffers by handling each expression from the tokenizer.
   # It returns Macro.t/0 or it raises.
 
-  defp generate_buffer([{:text, chars, meta} | rest], buffer, scope, state) do
+  defp generate_buffer([{:text, line, column, chars} | rest], buffer, scope, state) do
     buffer =
       if function_exported?(state.engine, :handle_text, 3) do
-        meta = [line: meta.line, column: meta.column]
+        meta = [line: line, column: column]
         state.engine.handle_text(buffer, meta, IO.chardata_to_string(chars))
       else
-        # TODO: Deprecate this branch on Elixir v1.18.
-        # We should most likely move this check to init to emit the deprecation once.
+        # TODO: Remove this branch on Elixir v2.0
         state.engine.handle_text(buffer, IO.chardata_to_string(chars))
       end
 
     generate_buffer(rest, buffer, scope, state)
   end
 
-  defp generate_buffer([{:expr, mark, chars, meta} | rest], buffer, scope, state) do
-    options =
-      [file: state.file, line: meta.line, column: column(meta.column, mark)] ++
-        state.parser_options
-
+  defp generate_buffer([{:expr, line, column, mark, chars} | rest], buffer, scope, state) do
+    options = [file: state.file, line: line, column: column(column, mark)] ++ state.parser_options
     expr = Code.string_to_quoted!(chars, options)
     buffer = state.engine.handle_expr(buffer, IO.chardata_to_string(mark), expr)
     generate_buffer(rest, buffer, scope, state)
   end
 
   defp generate_buffer(
-         [{:start_expr, mark, chars, meta} | rest],
+         [{:start_expr, start_line, start_column, mark, chars} | rest],
          buffer,
          scope,
          state
        ) do
-    if mark == '' do
+    if mark != '=' do
       message =
         "the contents of this expression won't be output unless the EEx block starts with \"<%=\""
 
-      :elixir_errors.erl_warn({meta.line, meta.column}, state.file, message)
+      :elixir_errors.erl_warn(start_line, state.file, message)
     end
 
-    {rest, line, contents} = look_ahead_middle(rest, meta.line, chars) || {rest, meta.line, chars}
+    {contents, line, rest} = look_ahead_middle(rest, start_line, chars)
 
     {contents, rest} =
       generate_buffer(
@@ -352,8 +85,8 @@ defmodule EEx.Compiler do
           state
           | quoted: [],
             line: line,
-            start_line: meta.line,
-            start_column: column(meta.column, mark)
+            start_line: start_line,
+            start_column: column(start_column, mark)
         }
       )
 
@@ -362,31 +95,47 @@ defmodule EEx.Compiler do
   end
 
   defp generate_buffer(
-         [{:middle_expr, '', chars, meta} | rest],
+         [{:middle_expr, line, _column, '', chars} | rest],
          buffer,
          [current | scope],
          state
        ) do
-    {wrapped, state} = wrap_expr(current, meta.line, buffer, chars, state)
-    state = %{state | line: meta.line}
+    {wrapped, state} = wrap_expr(current, line, buffer, chars, state)
+    state = %{state | line: line}
     generate_buffer(rest, state.engine.handle_begin(buffer), [wrapped | scope], state)
   end
 
-  defp generate_buffer([{:middle_expr, _, chars, meta} | _], _buffer, [], state) do
+  defp generate_buffer(
+         [{:middle_expr, line, column, modifier, chars} | t],
+         buffer,
+         [_ | _] = scope,
+         state
+       ) do
+    message =
+      "unexpected beginning of EEx tag \"<%#{modifier}\" on \"<%#{modifier}#{chars}%>\", " <>
+        "please remove \"#{modifier}\" accordingly"
+
+    :elixir_errors.erl_warn(line, state.file, message)
+    generate_buffer([{:middle_expr, line, column, '', chars} | t], buffer, scope, state)
+    # TODO: Make this an error on Elixir v2.0 since it accidentally worked previously.
+    # raise EEx.SyntaxError, message: message, file: state.file, line: line
+  end
+
+  defp generate_buffer([{:middle_expr, line, column, _, chars} | _], _buffer, [], state) do
     raise EEx.SyntaxError,
       message: "unexpected middle of expression <%#{chars}%>",
       file: state.file,
-      line: meta.line,
-      column: meta.column
+      line: line,
+      column: column
   end
 
   defp generate_buffer(
-         [{:end_expr, '', chars, meta} | rest],
+         [{:end_expr, line, _column, '', chars} | rest],
          buffer,
          [current | _],
          state
        ) do
-    {wrapped, state} = wrap_expr(current, meta.line, buffer, chars, state)
+    {wrapped, state} = wrap_expr(current, line, buffer, chars, state)
     column = state.start_column
     options = [file: state.file, line: state.start_line, column: column] ++ state.parser_options
     tuples = Code.string_to_quoted!(wrapped, options)
@@ -394,24 +143,40 @@ defmodule EEx.Compiler do
     {buffer, rest}
   end
 
-  defp generate_buffer([{:end_expr, _, chars, meta} | _], _buffer, [], state) do
+  defp generate_buffer(
+         [{:end_expr, line, column, modifier, chars} | t],
+         buffer,
+         [_ | _] = scope,
+         state
+       ) do
+    message =
+      "unexpected beginning of EEx tag \"<%#{modifier}\" on end of " <>
+        "expression \"<%#{modifier}#{chars}%>\", please remove \"#{modifier}\" accordingly"
+
+    :elixir_errors.erl_warn(line, state.file, message)
+    generate_buffer([{:end_expr, line, column, '', chars} | t], buffer, scope, state)
+    # TODO: Make this an error on Elixir v2.0 since it accidentally worked previously.
+    # raise EEx.SyntaxError, message: message, file: state.file, line: line, column: column
+  end
+
+  defp generate_buffer([{:end_expr, line, column, _, chars} | _], _buffer, [], state) do
     raise EEx.SyntaxError,
       message: "unexpected end of expression <%#{chars}%>",
       file: state.file,
-      line: meta.line,
-      column: meta.column
+      line: line,
+      column: column
   end
 
-  defp generate_buffer([{:eof, _meta}], buffer, [], state) do
+  defp generate_buffer([{:eof, _, _}], buffer, [], state) do
     state.engine.handle_body(buffer)
   end
 
-  defp generate_buffer([{:eof, meta}], _buffer, _scope, state) do
+  defp generate_buffer([{:eof, line, column}], _buffer, _scope, state) do
     raise EEx.SyntaxError,
       message: "unexpected end of string, expected a closing '<% end %>'",
       file: state.file,
-      line: meta.line,
-      column: meta.column
+      line: line,
+      column: column
   end
 
   # Creates a placeholder and wrap it inside the expression block
@@ -428,27 +193,28 @@ defmodule EEx.Compiler do
 
   # Look middle expressions that immediately follow a start_expr
 
-  defp look_ahead_middle([{:comment, _comment, _meta} | rest], start, contents),
-    do: look_ahead_middle(rest, start, contents)
-
-  defp look_ahead_middle([{:text, text, _meta} | rest], start, contents) do
+  defp look_ahead_middle(
+         [{:text, _, _, text}, {:middle_expr, line, _, _, chars} | rest] = tokens,
+         start,
+         contents
+       ) do
     if only_spaces?(text) do
-      look_ahead_middle(rest, start, contents ++ text)
+      {contents ++ text ++ chars, line, rest}
     else
-      nil
+      {contents, start, tokens}
     end
   end
 
-  defp look_ahead_middle([{:middle_expr, _, chars, meta} | rest], _start, contents) do
-    {rest, meta.line, contents ++ chars}
+  defp look_ahead_middle([{:middle_expr, line, _column, _, chars} | rest], _start, contents) do
+    {contents ++ chars, line, rest}
   end
 
-  defp look_ahead_middle(_tokens, _start, _contents) do
-    nil
+  defp look_ahead_middle(tokens, start, contents) do
+    {contents, start, tokens}
   end
 
   defp only_spaces?(chars) do
-    Enum.all?(chars, &(&1 in @all_spaces))
+    Enum.all?(chars, &(&1 in [?\s, ?\t, ?\r, ?\n]))
   end
 
   # Changes placeholder to real expression

lib/eex/lib/eex/tokenizer.ex

@@ -0,0 +1,234 @@
+defmodule EEx.Tokenizer do
+  @moduledoc false
+
+  @type content :: IO.chardata()
+  @type line :: non_neg_integer
+  @type column :: non_neg_integer
+  @type marker :: '=' | '/' | '|' | ''
+  @type token ::
+          {:text, line, column, content}
+          | {:expr | :start_expr | :middle_expr | :end_expr, line, column, marker, content}
+          | {:eof, line, column}
+
+  @spaces [?\s, ?\t]
+
+  @doc """
+  Tokenizes the given charlist or binary.
+
+  It returns {:ok, list} with the following tokens:
+
+    * `{:text, line, column, content}`
+    * `{:expr, line, column, marker, content}`
+    * `{:start_expr, line, column, marker, content}`
+    * `{:middle_expr, line, column, marker, content}`
+    * `{:end_expr, line, column, marker, content}`
+    * `{:eof, line, column}`
+
+  Or `{:error, line, column, message}` in case of errors.
+  """
+  @spec tokenize(binary | charlist, line, column, map) ::
+          {:ok, [token]} | {:error, line, column, String.t()}
+
+  def tokenize(bin, line, column, opts) when is_binary(bin) do
+    tokenize(String.to_charlist(bin), line, column, opts)
+  end
+
+  def tokenize(list, line, column, opts)
+      when is_list(list) and is_integer(line) and line >= 0 and is_integer(column) and column >= 0 do
+    column = opts.indentation + column
+
+    {list, line, column} =
+      (opts.trim && trim_init(list, line, column, opts)) || {list, line, column}
+
+    tokenize(list, line, column, opts, [{line, column}], [])
+  end
+
+  defp tokenize('<%%' ++ t, line, column, opts, buffer, acc) do
+    tokenize(t, line, column + 3, opts, [?%, ?< | buffer], acc)
+  end
+
+  defp tokenize('<%#' ++ t, line, column, opts, buffer, acc) do
+    case expr(t, line, column + 3, opts, []) do
+      {:error, _, _, _} = error ->
+        error
+
+      {:ok, _, new_line, new_column, rest} ->
+        {rest, new_line, new_column, buffer} =
+          trim_if_needed(rest, new_line, new_column, opts, buffer)
+
+        acc = tokenize_text(buffer, acc)
+        tokenize(rest, new_line, new_column, opts, [{new_line, new_column}], acc)
+    end
+  end
+
+  defp tokenize('<%' ++ t, line, column, opts, buffer, acc) do
+    {marker, t} = retrieve_marker(t)
+
+    case expr(t, line, column + 2 + length(marker), opts, []) do
+      {:error, _, _, _} = error ->
+        error
+
+      {:ok, expr, new_line, new_column, rest} ->
+        {key, expr} =
+          case :elixir_tokenizer.tokenize(expr, 1, file: "eex", check_terminators: false) do
+            {:ok, tokens} -> token_key(tokens, expr)
+            {:error, _, _, _} -> {:expr, expr}
+          end
+
+        {rest, new_line, new_column, buffer} =
+          trim_if_needed(rest, new_line, new_column, opts, buffer)
+
+        acc = tokenize_text(buffer, acc)
+        final = {key, line, column, marker, expr}
+        tokenize(rest, new_line, new_column, opts, [{new_line, new_column}], [final | acc])
+    end
+  end
+
+  defp tokenize('\n' ++ t, line, _column, opts, buffer, acc) do
+    tokenize(t, line + 1, opts.indentation + 1, opts, [?\n | buffer], acc)
+  end
+
+  defp tokenize([h | t], line, column, opts, buffer, acc) do
+    tokenize(t, line, column + 1, opts, [h | buffer], acc)
+  end
+
+  defp tokenize([], line, column, _opts, buffer, acc) do
+    eof = {:eof, line, column}
+    {:ok, Enum.reverse([eof | tokenize_text(buffer, acc)])}
+  end
+
+  # Retrieve marker for <%
+
+  defp retrieve_marker([marker | t]) when marker in [?=, ?/, ?|] do
+    {[marker], t}
+  end
+
+  defp retrieve_marker(t) do
+    {'', t}
+  end
+
+  # Tokenize an expression until we find %>
+
+  defp expr([?%, ?> | t], line, column, _opts, buffer) do
+    {:ok, Enum.reverse(buffer), line, column + 2, t}
+  end
+
+  defp expr('\n' ++ t, line, _column, opts, buffer) do
+    expr(t, line + 1, opts.indentation + 1, opts, [?\n | buffer])
+  end
+
+  defp expr([h | t], line, column, opts, buffer) do
+    expr(t, line, column + 1, opts, [h | buffer])
+  end
+
+  defp expr([], line, column, _opts, _buffer) do
+    {:error, line, column, "missing token '%>'"}
+  end
+
+  # Receives tokens and check if it is a start, middle or an end token.
+  defp token_key(tokens, expr) do
+    case {tokens, Enum.reverse(tokens)} do
+      {[{:end, _} | _], [{:do, _} | _]} ->
+        {:middle_expr, expr}
+
+      {_, [{:do, _} | _]} ->
+        {:start_expr, maybe_append_space(expr)}
+
+      {_, [{:block_identifier, _, _} | _]} ->
+        {:middle_expr, maybe_append_space(expr)}
+
+      {[{:end, _} | _], [{:stab_op, _, _} | _]} ->
+        {:middle_expr, expr}
+
+      {_, [{:stab_op, _, _} | reverse_tokens]} ->
+        fn_index = Enum.find_index(reverse_tokens, &match?({:fn, _}, &1)) || :infinity
+        end_index = Enum.find_index(reverse_tokens, &match?({:end, _}, &1)) || :infinity
+
+        if end_index > fn_index do
+          {:start_expr, expr}
+        else
+          {:middle_expr, expr}
+        end
+
+      {tokens, _} ->
+        case Enum.drop_while(tokens, &closing_bracket?/1) do
+          [{:end, _} | _] -> {:end_expr, expr}
+          _ -> {:expr, expr}
+        end
+    end
+  end
+
+  defp maybe_append_space([?\s]), do: [?\s]
+  defp maybe_append_space([h]), do: [h, ?\s]
+  defp maybe_append_space([h | t]), do: [h | maybe_append_space(t)]
+
+  defp closing_bracket?({closing, _}) when closing in ~w"( [ {"a, do: true
+  defp closing_bracket?(_), do: false
+
+  # Tokenize the buffered text by appending
+  # it to the given accumulator.
+
+  defp tokenize_text([{_line, _column}], acc) do
+    acc
+  end
+
+  defp tokenize_text(buffer, acc) do
+    [{line, column} | buffer] = Enum.reverse(buffer)
+    [{:text, line, column, buffer} | acc]
+  end
+
+  defp trim_if_needed(rest, line, column, opts, buffer) do
+    if opts.trim do
+      buffer = trim_left(buffer, 0)
+      {rest, line, column} = trim_right(rest, line, column, 0, opts)
+      {rest, line, column, buffer}
+    else
+      {rest, line, column, buffer}
+    end
+  end
+
+  defp trim_init([h | t], line, column, opts) when h in @spaces,
+    do: trim_init(t, line, column + 1, opts)
+
+  defp trim_init([?\r, ?\n | t], line, _column, opts),
+    do: trim_init(t, line + 1, opts.indentation + 1, opts)
+
+  defp trim_init([?\n | t], line, _column, opts),
+    do: trim_init(t, line + 1, opts.indentation + 1, opts)
+
+  defp trim_init([?<, ?% | _] = rest, line, column, _opts),
+    do: {rest, line, column}
+
+  defp trim_init(_, _, _, _), do: false
+
+  defp trim_left(buffer, count) do
+    case trim_whitespace(buffer, 0) do
+      {[?\n, ?\r | rest], _} -> trim_left(rest, count + 1)
+      {[?\n | rest], _} -> trim_left(rest, count + 1)
+      _ when count > 0 -> [?\n | buffer]
+      _ -> buffer
+    end
+  end
+
+  defp trim_right(rest, line, column, last_column, opts) do
+    case trim_whitespace(rest, column) do
+      {[?\r, ?\n | rest], column} ->
+        trim_right(rest, line + 1, opts.indentation + 1, column + 1, opts)
+
+      {[?\n | rest], column} ->
+        trim_right(rest, line + 1, opts.indentation + 1, column, opts)
+
+      {[], column} ->
+        {[], line, column}
+
+      _ when last_column > 0 ->
+        {[?\n | rest], line - 1, last_column}
+
+      _ ->
+        {rest, line, column}
+    end
+  end
+
+  defp trim_whitespace([h | t], column) when h in @spaces, do: trim_whitespace(t, column + 1)
+  defp trim_whitespace(list, column), do: {list, column}
+end

lib/eex/test/eex/tokenizer_test.exs

@@ -2,67 +2,41 @@ Code.require_file("../test_helper.exs", __DIR__)
 
 defmodule EEx.TokenizerTest do
   use ExUnit.Case, async: true
+  require EEx.Tokenizer, as: T
 
-  @opts [indentation: 0, trim: false]
+  @opts %{indentation: 0, trim: false}
 
   test "simple chars lists" do
-    assert EEx.tokenize('foo', @opts) ==
-             {:ok, [{:text, 'foo', %{column: 1, line: 1}}, {:eof, %{column: 4, line: 1}}]}
+    assert T.tokenize('foo', 1, 1, @opts) == {:ok, [{:text, 1, 1, 'foo'}, {:eof, 1, 4}]}
   end
 
   test "simple strings" do
-    assert EEx.tokenize("foo", @opts) ==
-             {:ok, [{:text, 'foo', %{column: 1, line: 1}}, {:eof, %{column: 4, line: 1}}]}
+    assert T.tokenize("foo", 1, 1, @opts) == {:ok, [{:text, 1, 1, 'foo'}, {:eof, 1, 4}]}
   end
 
   test "strings with embedded code" do
-    assert EEx.tokenize('foo <% bar %>', @opts) ==
-             {:ok,
-              [
-                {:text, 'foo ', %{column: 1, line: 1}},
-                {:expr, '', ' bar ', %{column: 5, line: 1}},
-                {:eof, %{column: 14, line: 1}}
-              ]}
+    assert T.tokenize('foo <% bar %>', 1, 1, @opts) ==
+             {:ok, [{:text, 1, 1, 'foo '}, {:expr, 1, 5, '', ' bar '}, {:eof, 1, 14}]}
   end
 
   test "strings with embedded equals code" do
-    assert EEx.tokenize('foo <%= bar %>', @opts) ==
-             {:ok,
-              [
-                {:text, 'foo ', %{column: 1, line: 1}},
-                {:expr, '=', ' bar ', %{column: 5, line: 1}},
-                {:eof, %{column: 15, line: 1}}
-              ]}
+    assert T.tokenize('foo <%= bar %>', 1, 1, @opts) ==
+             {:ok, [{:text, 1, 1, 'foo '}, {:expr, 1, 5, '=', ' bar '}, {:eof, 1, 15}]}
   end
 
   test "strings with embedded slash code" do
-    assert EEx.tokenize('foo <%/ bar %>', @opts) ==
-             {:ok,
-              [
-                {:text, 'foo ', %{column: 1, line: 1}},
-                {:expr, '/', ' bar ', %{column: 5, line: 1}},
-                {:eof, %{column: 15, line: 1}}
-              ]}
+    assert T.tokenize('foo <%/ bar %>', 1, 1, @opts) ==
+             {:ok, [{:text, 1, 1, 'foo '}, {:expr, 1, 5, '/', ' bar '}, {:eof, 1, 15}]}
   end
 
   test "strings with embedded pipe code" do
-    assert EEx.tokenize('foo <%| bar %>', @opts) ==
-             {:ok,
-              [
-                {:text, 'foo ', %{column: 1, line: 1}},
-                {:expr, '|', ' bar ', %{column: 5, line: 1}},
-                {:eof, %{column: 15, line: 1}}
-              ]}
+    assert T.tokenize('foo <%| bar %>', 1, 1, @opts) ==
+             {:ok, [{:text, 1, 1, 'foo '}, {:expr, 1, 5, '|', ' bar '}, {:eof, 1, 15}]}
   end
 
   test "strings with more than one line" do
-    assert EEx.tokenize('foo\n<%= bar %>', @opts) ==
-             {:ok,
-              [
-                {:text, 'foo\n', %{column: 1, line: 1}},
-                {:expr, '=', ' bar ', %{column: 1, line: 2}},
-                {:eof, %{column: 11, line: 2}}
-              ]}
+    assert T.tokenize('foo\n<%= bar %>', 1, 1, @opts) ==
+             {:ok, [{:text, 1, 1, 'foo\n'}, {:expr, 2, 1, '=', ' bar '}, {:eof, 2, 11}]}
   end
 
   test "strings with more than one line and expression with more than one line" do
@@ -74,235 +48,157 @@ defmodule EEx.TokenizerTest do
     '''
 
     exprs = [
-      {:text, 'foo ', %{column: 1, line: 1}},
-      {:expr, '=', ' bar\n\nbaz ', %{column: 5, line: 1}},
-      {:text, '\n', %{column: 7, line: 3}},
-      {:expr, '', ' foo ', %{column: 1, line: 4}},
-      {:text, '\n', %{column: 10, line: 4}},
-      {:eof, %{column: 1, line: 5}}
+      {:text, 1, 1, 'foo '},
+      {:expr, 1, 5, '=', ' bar\n\nbaz '},
+      {:text, 3, 7, '\n'},
+      {:expr, 4, 1, '', ' foo '},
+      {:text, 4, 10, '\n'},
+      {:eof, 5, 1}
     ]
 
-    assert EEx.tokenize(string, @opts) == {:ok, exprs}
+    assert T.tokenize(string, 1, 1, @opts) == {:ok, exprs}
   end
 
   test "quotation" do
-    assert EEx.tokenize('foo <%% true %>', @opts) ==
-             {:ok,
-              [
-                {:text, 'foo <% true %>', %{column: 1, line: 1}},
-                {:eof, %{column: 16, line: 1}}
-              ]}
+    assert T.tokenize('foo <%% true %>', 1, 1, @opts) ==
+             {:ok, [{:text, 1, 1, 'foo <% true %>'}, {:eof, 1, 16}]}
   end
 
-  test "quotation with do-end" do
-    assert EEx.tokenize('foo <%% true do %>bar<%% end %>', @opts) ==
-             {:ok,
-              [
-                {:text, 'foo <% true do %>bar<% end %>', %{column: 1, line: 1}},
-                {:eof, %{column: 32, line: 1}}
-              ]}
+  test "quotation with do/end" do
+    assert T.tokenize('foo <%% true do %>bar<%% end %>', 1, 1, @opts) ==
+             {:ok, [{:text, 1, 1, 'foo <% true do %>bar<% end %>'}, {:eof, 1, 32}]}
   end
 
   test "quotation with interpolation" do
     exprs = [
-      {:text, 'a <% b ', %{column: 1, line: 1}},
-      {:expr, '=', ' c ', %{column: 9, line: 1}},
-      {:text, ' ', %{column: 17, line: 1}},
-      {:expr, '=', ' d ', %{column: 18, line: 1}},
-      {:text, ' e %> f', %{column: 26, line: 1}},
-      {:eof, %{column: 33, line: 1}}
+      {:text, 1, 1, 'a <% b '},
+      {:expr, 1, 9, '=', ' c '},
+      {:text, 1, 17, ' '},
+      {:expr, 1, 18, '=', ' d '},
+      {:text, 1, 26, ' e %> f'},
+      {:eof, 1, 33}
     ]
 
-    assert EEx.tokenize('a <%% b <%= c %> <%= d %> e %> f', @opts) == {:ok, exprs}
+    assert T.tokenize('a <%% b <%= c %> <%= d %> e %> f', 1, 1, @opts) == {:ok, exprs}
   end
 
   test "improperly formatted quotation with interpolation" do
     exprs = [
-      {:text, '<%% a <%= b %> c %>', %{column: 1, line: 1}},
-      {:eof, %{column: 22, line: 1}}
+      {:text, 1, 1, '<%% a <%= b %> c %>'},
+      {:eof, 1, 22}
     ]
 
-    assert EEx.tokenize('<%%% a <%%= b %> c %>', @opts) == {:ok, exprs}
+    assert T.tokenize('<%%% a <%%= b %> c %>', 1, 1, @opts) == {:ok, exprs}
   end
 
-  test "EEx comments" do
+  test "eex comments" do
     exprs = [
-      {:text, 'foo ', %{column: 1, line: 1}},
-      {:eof, %{column: 16, line: 1}}
+      {:text, 1, 1, 'foo '},
+      {:eof, 1, 16}
     ]
 
-    assert EEx.tokenize('foo <%# true %>', @opts) == {:ok, exprs}
-
-    exprs = [
-      {:text, 'foo ', %{column: 1, line: 1}},
-      {:eof, %{column: 8, line: 2}}
-    ]
-
-    assert EEx.tokenize('foo <%#\ntrue %>', @opts) == {:ok, exprs}
+    assert T.tokenize('foo <%# true %>', 1, 1, @opts) == {:ok, exprs}
   end
 
-  test "EEx comments with do-end" do
+  test "eex comments with do/end" do
     exprs = [
-      {:text, 'foo ', %{column: 1, line: 1}},
-      {:text, 'bar', %{column: 19, line: 1}},
-      {:eof, %{column: 32, line: 1}}
+      {:text, 1, 1, 'foo '},
+      {:text, 1, 19, 'bar'},
+      {:eof, 1, 32}
     ]
 
-    assert EEx.tokenize('foo <%# true do %>bar<%# end %>', @opts) == {:ok, exprs}
+    assert T.tokenize('foo <%# true do %>bar<%# end %>', 1, 1, @opts) == {:ok, exprs}
   end
 
-  test "EEx comments inside do-end" do
+  test "elixir comments" do
     exprs = [
-      {:start_expr, '', ' if true do ', %{column: 1, line: 1}},
-      {:text, 'bar', %{column: 31, line: 1}},
-      {:end_expr, [], ' end ', %{column: 34, line: 1}},
-      {:eof, %{column: 43, line: 1}}
+      {:text, 1, 1, 'foo '},
+      {:expr, 1, 5, [], ' true # this is a boolean '},
+      {:eof, 1, 35}
     ]
 
-    assert EEx.tokenize('<% if true do %><%# comment %>bar<% end %>', @opts) == {:ok, exprs}
-
-    exprs = [
-      {:start_expr, [], ' case true do ', %{column: 1, line: 1}},
-      {:middle_expr, '', ' true -> ', %{column: 33, line: 1}},
-      {:text, 'bar', %{column: 46, line: 1}},
-      {:end_expr, [], ' end ', %{column: 49, line: 1}},
-      {:eof, %{column: 58, line: 1}}
-    ]
-
-    assert EEx.tokenize('<% case true do %><%# comment %><% true -> %>bar<% end %>', @opts) ==
-             {:ok, exprs}
+    assert T.tokenize('foo <% true # this is a boolean %>', 1, 1, @opts) == {:ok, exprs}
   end
 
-  test "EEx multi-line comments" do
+  test "elixir comments with do/end" do
     exprs = [
-      {:text, 'foo ', %{column: 1, line: 1}},
-      {:comment, ' true ', %{column: 5, line: 1}},
-      {:text, ' bar', %{column: 20, line: 1}},
-      {:eof, %{column: 24, line: 1}}
+      {:start_expr, 1, 1, [], ' if true do # startif '},
+      {:text, 1, 27, 'text'},
+      {:end_expr, 1, 31, [], ' end # closeif '},
+      {:eof, 1, 50}
     ]
 
-    assert EEx.tokenize('foo <%!-- true --%> bar', @opts) == {:ok, exprs}
-
-    exprs = [
-      {:text, 'foo ', %{column: 1, line: 1}},
-      {:comment, ' \ntrue\n ', %{column: 5, line: 1}},
-      {:text, ' bar', %{column: 6, line: 3}},
-      {:eof, %{column: 10, line: 3}}
-    ]
-
-    assert EEx.tokenize('foo <%!-- \ntrue\n --%> bar', @opts) == {:ok, exprs}
-
-    exprs = [
-      {:text, 'foo ', %{column: 1, line: 1}},
-      {:comment, ' <%= true %> ', %{column: 5, line: 1}},
-      {:text, ' bar', %{column: 27, line: 1}},
-      {:eof, %{column: 31, line: 1}}
-    ]
-
-    assert EEx.tokenize('foo <%!-- <%= true %> --%> bar', @opts) == {:ok, exprs}
-  end
-
-  test "Elixir comments" do
-    exprs = [
-      {:text, 'foo ', %{column: 1, line: 1}},
-      {:expr, [], ' true # this is a boolean ', %{column: 5, line: 1}},
-      {:eof, %{column: 35, line: 1}}
-    ]
-
-    assert EEx.tokenize('foo <% true # this is a boolean %>', @opts) == {:ok, exprs}
-  end
-
-  test "Elixir comments with do-end" do
-    exprs = [
-      {:start_expr, [], ' if true do # startif ', %{column: 1, line: 1}},
-      {:text, 'text', %{column: 27, line: 1}},
-      {:end_expr, [], ' end # closeif ', %{column: 31, line: 1}},
-      {:eof, %{column: 50, line: 1}}
-    ]
-
-    assert EEx.tokenize('<% if true do # startif %>text<% end # closeif %>', @opts) ==
+    assert T.tokenize('<% if true do # startif %>text<% end # closeif %>', 1, 1, @opts) ==
              {:ok, exprs}
   end
 
   test "strings with embedded do end" do
     exprs = [
-      {:text, 'foo ', %{column: 1, line: 1}},
-      {:start_expr, '', ' if true do ', %{column: 5, line: 1}},
-      {:text, 'bar', %{column: 21, line: 1}},
-      {:end_expr, '', ' end ', %{column: 24, line: 1}},
-      {:eof, %{column: 33, line: 1}}
+      {:text, 1, 1, 'foo '},
+      {:start_expr, 1, 5, '', ' if true do '},
+      {:text, 1, 21, 'bar'},
+      {:end_expr, 1, 24, '', ' end '},
+      {:eof, 1, 33}
     ]
 
-    assert EEx.tokenize('foo <% if true do %>bar<% end %>', @opts) == {:ok, exprs}
+    assert T.tokenize('foo <% if true do %>bar<% end %>', 1, 1, @opts) == {:ok, exprs}
   end
 
   test "strings with embedded -> end" do
     exprs = [
-      {:text, 'foo ', %{column: 1, line: 1}},
-      {:start_expr, '', ' cond do ', %{column: 5, line: 1}},
-      {:middle_expr, '', ' false -> ', %{column: 18, line: 1}},
-      {:text, 'bar', %{column: 32, line: 1}},
-      {:middle_expr, '', ' true -> ', %{column: 35, line: 1}},
-      {:text, 'baz', %{column: 48, line: 1}},
-      {:end_expr, '', ' end ', %{column: 51, line: 1}},
-      {:eof, %{column: 60, line: 1}}
+      {:text, 1, 1, 'foo '},
+      {:start_expr, 1, 5, '', ' cond do '},
+      {:middle_expr, 1, 18, '', ' false -> '},
+      {:text, 1, 32, 'bar'},
+      {:middle_expr, 1, 35, '', ' true -> '},
+      {:text, 1, 48, 'baz'},
+      {:end_expr, 1, 51, '', ' end '},
+      {:eof, 1, 60}
     ]
 
-    assert EEx.tokenize('foo <% cond do %><% false -> %>bar<% true -> %>baz<% end %>', @opts) ==
+    assert T.tokenize('foo <% cond do %><% false -> %>bar<% true -> %>baz<% end %>', 1, 1, @opts) ==
              {:ok, exprs}
   end
 
-  test "strings with fn-end with newline" do
+  test "strings with multiple callbacks" do
     exprs = [
-      {:start_expr, '=', ' a fn ->\n', %{column: 1, line: 1}},
-      {:text, 'foo', %{column: 3, line: 2}},
-      {:end_expr, [], ' end ', %{column: 6, line: 2}},
-      {:eof, %{column: 15, line: 2}}
+      {:start_expr, 1, 1, '=', ' a fn -> '},
+      {:text, 1, 15, 'foo'},
+      {:middle_expr, 1, 18, '', ' end, fn -> '},
+      {:text, 1, 34, 'bar'},
+      {:end_expr, 1, 37, '', ' end '},
+      {:eof, 1, 46}
     ]
 
-    assert EEx.tokenize('<%= a fn ->\n%>foo<% end %>', @opts) ==
+    assert T.tokenize('<%= a fn -> %>foo<% end, fn -> %>bar<% end %>', 1, 1, @opts) ==
              {:ok, exprs}
   end
 
-  test "strings with multiple fn-end" do
+  test "strings with callback followed by do block" do
     exprs = [
-      {:start_expr, '=', ' a fn -> ', %{column: 1, line: 1}},
-      {:text, 'foo', %{column: 15, line: 1}},
-      {:middle_expr, '', ' end, fn -> ', %{column: 18, line: 1}},
-      {:text, 'bar', %{column: 34, line: 1}},
-      {:end_expr, '', ' end ', %{column: 37, line: 1}},
-      {:eof, %{column: 46, line: 1}}
+      {:start_expr, 1, 1, '=', ' a fn -> '},
+      {:text, 1, 15, 'foo'},
+      {:middle_expr, 1, 18, '', ' end do '},
+      {:text, 1, 30, 'bar'},
+      {:end_expr, 1, 33, '', ' end '},
+      {:eof, 1, 42}
     ]
 
-    assert EEx.tokenize('<%= a fn -> %>foo<% end, fn -> %>bar<% end %>', @opts) ==
-             {:ok, exprs}
-  end
-
-  test "strings with fn-end followed by do block" do
-    exprs = [
-      {:start_expr, '=', ' a fn -> ', %{column: 1, line: 1}},
-      {:text, 'foo', %{column: 15, line: 1}},
-      {:middle_expr, '', ' end do ', %{column: 18, line: 1}},
-      {:text, 'bar', %{column: 30, line: 1}},
-      {:end_expr, '', ' end ', %{column: 33, line: 1}},
-      {:eof, %{column: 42, line: 1}}
-    ]
-
-    assert EEx.tokenize('<%= a fn -> %>foo<% end do %>bar<% end %>', @opts) == {:ok, exprs}
+    assert T.tokenize('<%= a fn -> %>foo<% end do %>bar<% end %>', 1, 1, @opts) == {:ok, exprs}
   end
 
   test "strings with embedded keywords blocks" do
     exprs = [
-      {:text, 'foo ', %{column: 1, line: 1}},
-      {:start_expr, '', ' if true do ', %{column: 5, line: 1}},
-      {:text, 'bar', %{column: 21, line: 1}},
-      {:middle_expr, '', ' else ', %{column: 24, line: 1}},
-      {:text, 'baz', %{column: 34, line: 1}},
-      {:end_expr, '', ' end ', %{column: 37, line: 1}},
-      {:eof, %{column: 46, line: 1}}
+      {:text, 1, 1, 'foo '},
+      {:start_expr, 1, 5, '', ' if true do '},
+      {:text, 1, 21, 'bar'},
+      {:middle_expr, 1, 24, '', ' else '},
+      {:text, 1, 34, 'baz'},
+      {:end_expr, 1, 37, '', ' end '},
+      {:eof, 1, 46}
     ]
 
-    assert EEx.tokenize('foo <% if true do %>bar<% else %>baz<% end %>', @opts) ==
+    assert T.tokenize('foo <% if true do %>bar<% else %>baz<% end %>', 1, 1, @opts) ==
              {:ok, exprs}
   end
 
@@ -310,61 +206,51 @@ defmodule EEx.TokenizerTest do
     template = '\t<%= if true do %> \n TRUE \n  <% else %>\n FALSE \n  <% end %>  \n\n  '
 
     exprs = [
-      {:start_expr, '=', ' if true do ', %{column: 2, line: 1}},
-      {:text, '\n TRUE \n', %{column: 20, line: 1}},
-      {:middle_expr, '', ' else ', %{column: 3, line: 3}},
-      {:text, '\n FALSE \n', %{column: 13, line: 3}},
-      {:end_expr, '', ' end ', %{column: 3, line: 5}},
-      {:eof, %{column: 3, line: 7}}
+      {:start_expr, 1, 2, '=', ' if true do '},
+      {:text, 1, 20, '\n TRUE \n'},
+      {:middle_expr, 3, 3, '', ' else '},
+      {:text, 3, 13, '\n FALSE \n'},
+      {:end_expr, 5, 3, '', ' end '},
+      {:eof, 7, 3}
     ]
 
-    assert EEx.tokenize(template, [trim: true] ++ @opts) == {:ok, exprs}
+    assert T.tokenize(template, 1, 1, %{@opts | trim: true}) == {:ok, exprs}
   end
 
   test "trim mode with comment" do
     exprs = [
-      {:text, '\n123', %{column: 19, line: 1}},
-      {:eof, %{column: 4, line: 2}}
+      {:text, 1, 19, '\n123'},
+      {:eof, 2, 4}
     ]
 
-    assert EEx.tokenize('  <%# comment %>  \n123', [trim: true] ++ @opts) == {:ok, exprs}
-  end
-
-  test "trim mode with multi-line comment" do
-    exprs = [
-      {:comment, ' comment ', %{column: 3, line: 1}},
-      {:text, '\n123', %{column: 23, line: 1}},
-      {:eof, %{column: 4, line: 2}}
-    ]
-
-    assert EEx.tokenize('  <%!-- comment --%>  \n123', [trim: true] ++ @opts) == {:ok, exprs}
+    assert T.tokenize('  <%# comment %>  \n123', 1, 1, %{@opts | trim: true}) == {:ok, exprs}
   end
 
   test "trim mode with CRLF" do
     exprs = [
-      {:text, '0\n', %{column: 1, line: 1}},
-      {:expr, '=', ' 12 ', %{column: 3, line: 2}},
-      {:text, '\n34', %{column: 15, line: 2}},
-      {:eof, %{column: 3, line: 3}}
+      {:text, 1, 1, '0\n'},
+      {:expr, 2, 3, '=', ' 12 '},
+      {:text, 2, 15, '\n34'},
+      {:eof, 3, 3}
     ]
 
-    assert EEx.tokenize('0\r\n  <%= 12 %>  \r\n34', [trim: true] ++ @opts) == {:ok, exprs}
+    assert T.tokenize('0\r\n  <%= 12 %>  \r\n34', 1, 1, %{@opts | trim: true}) == {:ok, exprs}
   end
 
   test "trim mode set to false" do
     exprs = [
-      {:text, ' ', %{column: 1, line: 1}},
-      {:expr, '=', ' 12 ', %{column: 2, line: 1}},
-      {:text, ' \n', %{column: 11, line: 1}},
-      {:eof, %{column: 1, line: 2}}
+      {:text, 1, 1, ' '},
+      {:expr, 1, 2, '=', ' 12 '},
+      {:text, 1, 11, ' \n'},
+      {:eof, 2, 1}
     ]
 
-    assert EEx.tokenize(' <%= 12 %> \n', [trim: false] ++ @opts) == {:ok, exprs}
+    assert T.tokenize(' <%= 12 %> \n', 1, 1, %{@opts | trim: false}) == {:ok, exprs}
   end
 
   test "trim mode no false positives" do
     assert_not_trimmed = fn x ->
-      assert EEx.tokenize(x, [trim: false] ++ @opts) == EEx.tokenize(x, @opts)
+      assert T.tokenize(x, 1, 1, %{@opts | trim: false}) == T.tokenize(x, 1, 1, @opts)
     end
 
     assert_not_trimmed.('foo <%= "bar" %>  ')
@@ -374,22 +260,12 @@ defmodule EEx.TokenizerTest do
   end
 
   test "returns error when there is start mark and no end mark" do
-    assert EEx.tokenize('foo <% :bar', @opts) ==
-             {:error, "missing token '%>'", %{column: 12, line: 1}}
-
-    assert EEx.tokenize('<%# true ', @opts) ==
-             {:error, "missing token '%>'", %{column: 10, line: 1}}
-
-    assert EEx.tokenize('<%!-- foo ', @opts) ==
-             {:error, "missing token '--%>'", %{column: 11, line: 1}}
+    assert T.tokenize('foo <% :bar', 1, 1, @opts) == {:error, 1, 12, "missing token '%>'"}
+    assert T.tokenize('<%# true ', 1, 1, @opts) == {:error, 1, 10, "missing token '%>'"}
   end
 
   test "marks invalid expressions as regular expressions" do
-    assert EEx.tokenize('<% 1 $ 2 %>', @opts) ==
-             {:ok,
-              [
-                {:expr, [], ' 1 $ 2 ', %{column: 1, line: 1}},
-                {:eof, %{column: 12, line: 1}}
-              ]}
+    assert T.tokenize('<% 1 $ 2 %>', 1, 1, @opts) ==
+             {:ok, [{:expr, 1, 1, [], ' 1 $ 2 '}, {:eof, 1, 12}]}
   end
 end

lib/eex/test/eex_test.exs

@@ -198,24 +198,6 @@ defmodule EExTest do
       assert_eval("foo baz", "foo <%= if false do %>bar<% else %>baz<% end %>")
     end
 
-    test "embedded code with comments in do end" do
-      assert_eval("foo bar", "foo <%= case true do %><%# comment %><% true -> %>bar<% end %>")
-
-      assert_eval(
-        "foo\n\nbar\n",
-        "foo\n<%= case true do %>\n<%# comment %>\n<% true -> %>\nbar\n<% end %>"
-      )
-    end
-
-    test "embedded code with multi-line comments in do end" do
-      assert_eval("foo bar", "foo <%= case true do %><%!-- comment --%><% true -> %>bar<% end %>")
-
-      assert_eval(
-        "foo\n\nbar\n",
-        "foo\n<%= case true do %>\n<%!-- comment --%>\n<% true -> %>\nbar\n<% end %>"
-      )
-    end
-
     test "embedded code with nested do end" do
       assert_eval("foo bar", "foo <%= if true do %><%= if true do %>bar<% end %><% end %>")
     end
@@ -233,11 +215,6 @@ defmodule EExTest do
         "<%= Enum.map([1, 2, 3], fn x -> %> <%= 100 + x %> <% end) %>"
       )
 
-      assert_eval(
-        " 101  102  103 ",
-        "<%= Enum.map([1, 2, 3], fn x ->\n%> <%= 100 + x %> <% end) %>"
-      )
-
       assert_eval(
         " 101  102  103 ",
         "<%= apply Enum, :map, [[1, 2, 3], fn x -> %> <%= 100 + x %> <% end] %>"
@@ -317,7 +294,7 @@ defmodule EExTest do
       assert ExUnit.CaptureIO.capture_io(:stderr, fn ->
                EEx.compile_string("foo <%= if true do %>true<% else %>false<%= end %>")
              end) =~
-               ~s[unexpected beginning of EEx tag \"<%=\" on \"<%= end %>\"]
+               ~s[unexpected beginning of EEx tag \"<%=\" on end of expression \"<%= end %>\"]
     end
 
     test "when trying to use marker '/' without implementation" do
@@ -741,16 +718,6 @@ defmodule EExTest do
     end
   end
 
-  describe "parser options" do
-    test "customizes parsed code" do
-      atoms_encoder = fn "not_jose", _ -> {:ok, :jose} end
-
-      assert_eval("valid", "<%= not_jose %>", [jose: "valid"],
-        parser_options: [static_atoms_encoder: atoms_encoder]
-      )
-    end
-  end
-
   defp assert_eval(expected, actual, binding \\ [], opts \\ []) do
     opts = Keyword.merge([file: __ENV__.file, engine: opts[:engine] || EEx.Engine], opts)
     result = EEx.eval_string(actual, binding, opts)

lib/eex/test/test_helper.exs

@@ -1,8 +1 @@
-{line_exclude, line_include} =
-  if line = System.get_env("LINE"), do: {[:test], [line: line]}, else: {[], []}
-
-ExUnit.start(
-  trace: !!System.get_env("TRACE"),
-  include: line_include,
-  exclude: line_exclude
-)
+ExUnit.start(trace: "--trace" in System.argv())

lib/elixir/lib/access.ex

@@ -94,7 +94,8 @@ defmodule Access do
 
   @type container :: keyword | struct | map
   @type nil_container :: nil
-  @type t :: container | nil_container | any
+  @type any_container :: any
+  @type t :: container | nil_container | any_container
   @type key :: any
   @type value :: any
 
@@ -152,7 +153,7 @@ defmodule Access do
   """
   @callback get_and_update(data, key, (value | nil -> {current_value, new_value :: value} | :pop)) ::
               {current_value, new_data :: data}
-            when current_value: value, data: container
+            when current_value: value, data: container | any_container
 
   @doc """
   Invoked to "pop" the value under `key` out of the given data structure.
@@ -166,18 +167,14 @@ defmodule Access do
 
   See the implementations for `Map.pop/3` or `Keyword.pop/3` for more examples.
   """
-  @callback pop(data, key) :: {value, data} when data: container
+  @callback pop(data, key) :: {value, data} when data: container | any_container
 
   defmacrop raise_undefined_behaviour(exception, module, top) do
     quote do
       exception =
         case __STACKTRACE__ do
           [unquote(top) | _] ->
-            reason =
-              "#{inspect(unquote(module))} does not implement the Access behaviour. " <>
-                "If you are using get_in/put_in/update_in, you can specify the field " <>
-                "to be accessed using Access.key!/1"
-
+            reason = "#{inspect(unquote(module))} does not implement the Access behaviour"
             %{unquote(exception) | reason: reason}
 
           _ ->
@@ -448,6 +445,9 @@ defmodule Access do
 
   An error is raised if the accessed structure is not a map or a struct:
 
+      iex> get_in(nil, [Access.key(:foo)])
+      ** (BadMapError) expected a map, got: nil
+
       iex> get_in([], [Access.key(:foo)])
       ** (BadMapError) expected a map, got: []
 
@@ -829,118 +829,4 @@ defmodule Access do
   defp get_and_update_filter([], _func, _next, updates, gets) do
     {:lists.reverse(gets), :lists.reverse(updates)}
   end
-
-  @doc ~S"""
-  Returns a function that accesses all items of a list that are within the provided range.
-
-  The range will be normalized following the same rules from `Enum.slice/2`.
-
-  The returned function is typically passed as an accessor to `Kernel.get_in/2`,
-  `Kernel.get_and_update_in/3`, and friends.
-
-  ## Examples
-
-      iex> list = [%{name: "john", salary: 10}, %{name: "francine", salary: 30}, %{name: "vitor", salary: 25}]
-      iex> get_in(list, [Access.slice(1..2), :name])
-      ["francine", "vitor"]
-      iex> get_and_update_in(list, [Access.slice(1..3//2), :name], fn prev ->
-      ...>   {prev, String.upcase(prev)}
-      ...> end)
-      {["francine"], [%{name: "john", salary: 10}, %{name: "FRANCINE", salary: 30}, %{name: "vitor", salary: 25}]}
-
-  `slice/1` can also be used to pop elements out of a list or
-  a key inside of a list:
-
-      iex> list = [%{name: "john", salary: 10}, %{name: "francine", salary: 30}, %{name: "vitor", salary: 25}]
-      iex> pop_in(list, [Access.slice(-2..-1)])
-      {[%{name: "francine", salary: 30}, %{name: "vitor", salary: 25}], [%{name: "john", salary: 10}]}
-      iex> pop_in(list, [Access.slice(-2..-1), :name])
-      {["francine", "vitor"], [%{name: "john", salary: 10}, %{salary: 30}, %{salary: 25}]}
-
-  When no match is found, an empty list is returned and the update function is never called
-
-      iex> list = [%{name: "john", salary: 10}, %{name: "francine", salary: 30}, %{name: "vitor", salary: 25}]
-      iex> get_in(list, [Access.slice(5..10//2), :name])
-      []
-      iex> get_and_update_in(list, [Access.slice(5..10//2), :name], fn prev ->
-      ...>   {prev, String.upcase(prev)}
-      ...> end)
-      {[], [%{name: "john", salary: 10}, %{name: "francine", salary: 30}, %{name: "vitor", salary: 25}]}
-
-  An error is raised if the accessed structure is not a list:
-
-      iex> get_in(%{}, [Access.slice(2..10//3)])
-      ** (ArgumentError) Access.slice/1 expected a list, got: %{}
-
-  An error is raised if the step of the range is negative:
-
-      iex> get_in([], [Access.slice(2..10//-1)])
-      ** (ArgumentError) Access.slice/1 does not accept ranges with negative steps, got: 2..10//-1
-
-  """
-  @doc since: "1.14"
-  @spec slice(Range.t()) :: access_fun(data :: list, current_value :: list)
-  def slice(%Range{} = range) do
-    if range.step > 0 do
-      fn op, data, next -> slice(op, data, range, next) end
-    else
-      raise ArgumentError,
-            "Access.slice/1 does not accept ranges with negative steps, got: #{inspect(range)}"
-    end
-  end
-
-  defp slice(:get, data, %Range{} = range, next) when is_list(data) do
-    data
-    |> Enum.slice(range)
-    |> Enum.map(next)
-  end
-
-  defp slice(:get_and_update, data, range, next) when is_list(data) do
-    range = normalize_range(range, data)
-
-    if range.first > range.last do
-      {[], data}
-    else
-      get_and_update_slice(data, range, next, [], [], 0)
-    end
-  end
-
-  defp slice(_op, data, _range, _next) do
-    raise ArgumentError, "Access.slice/1 expected a list, got: #{inspect(data)}"
-  end
-
-  defp normalize_range(%Range{first: first, last: last, step: step}, list)
-       when first < 0 or last < 0 do
-    count = length(list)
-    first = if first >= 0, do: first, else: Kernel.max(first + count, 0)
-    last = if last >= 0, do: last, else: last + count
-    Range.new(first, last, step)
-  end
-
-  defp normalize_range(range, _list), do: range
-
-  defp get_and_update_slice([head | rest], range, next, updates, gets, index) do
-    if index in range do
-      case next.(head) do
-        :pop ->
-          get_and_update_slice(rest, range, next, updates, [head | gets], index + 1)
-
-        {get, update} ->
-          get_and_update_slice(
-            rest,
-            range,
-            next,
-            [update | updates],
-            [get | gets],
-            index + 1
-          )
-      end
-    else
-      get_and_update_slice(rest, range, next, [head | updates], gets, index + 1)
-    end
-  end
-
-  defp get_and_update_slice([], _range, _next, updates, gets, _index) do
-    {:lists.reverse(gets), :lists.reverse(updates)}
-  end
 end

lib/elixir/lib/application.ex

@@ -42,32 +42,18 @@ defmodule Application do
       end
 
   In Mix projects, the environment of the application and its dependencies can
-  be overridden via the `config/config.exs` and `config/runtime.exs` files. The
-  former is loaded at build-time, before your code compiles, and the latter at
-  runtime, just before your app starts. For example, someone using your application
-  can override its `:db_host` environment variable as follows:
+  be overridden via the `config/config.exs` file. For example, someone using
+  your application can override its `:db_host` environment variable as follows:
 
       import Config
       config :my_app, :db_host, "db.local"
 
-  See the "Configuration" section in the `Mix` module for more information.
   You can also change the application environment dynamically by using functions
-  such as `put_env/3` and `delete_env/2`.
+  such as `put_env/3` and `delete_env/2`. However, as a rule of thumb, each application
+  is responsible for its own environment. Please do not use the functions in this
+  module for directly accessing or modifying the environment of other applications.
 
-  > Note: The config files `config/config.exs` and `config/runtime.exs`
-  > are rarely used by libraries. Libraries typically define their environment
-  > in the `def application` function of their `mix.exs`. Configuration files
-  > are rather used by applications to configure their libraries.
-
-  > Note: Each application is responsible for its own environment. Do not
-  > use the functions in this module for directly accessing or modifying
-  > the environment of other applications. Whenever you change the application
-  > environment, Elixir's build tool will only recompile the files that
-  > belong to that application. So if you read the application environment
-  > of another application, there is a chance you will be depending on
-  > outdated configuration, as your file won't be recompiled as it changes.
-
-  ## Compile-time environment
+  ### Compile-time environment
 
   In the previous example, we read the application environment at runtime:
 
@@ -85,48 +71,36 @@ defmodule Application do
   will only be read when `MyApp.DBClient` effectively starts. While reading
   the application environment at runtime is the preferred approach, in some
   rare occasions you may want to use the application environment to configure
-  the compilation of a certain project. However, if you try to access
-  `Application.fetch_env!/2` outside of a function:
+  the compilation of a certain project. This is often done by calling `get_env/3`
+  outside of a function:
 
       defmodule MyApp.DBClient do
-        @db_host Application.fetch_env!(:my_app, :db_host)
+        @db_host Application.get_env(:my_app, :db_host, "db.local")
 
         def start_link() do
           SomeLib.DBClient.start_link(host: @db_host)
         end
       end
 
-  You might see warnings and errors:
+  This approach has one big limitation: if you change the value of the
+  application environment after the code is compiled, the value used at
+  runtime is not going to change! For example, if your `config/runtime.exs`
+  has:
 
-      warning: Application.fetch_env!/2 is discouraged in the module body,
-      use Application.compile_env/3 instead
-        iex:3: MyApp.DBClient
+      config :my_app, :db_host, "db.production"
 
-      ** (ArgumentError) could not fetch application environment :db_host
-      for application :my_app because the application was not loaded nor
-      configured
+  This value will have no effect as the code was compiled to connect to "db.local",
+  which is mostly likely unavailable in the production environment.
 
-  This happens because, when defining modules, the application environment
-  is not yet available. Luckily, the warning tells us how to solve this
-  issue, by using `Application.compile_env/3` instead:
+  For those reasons, reading the application environment at runtime should be the
+  first choice. However, if you really have to read the application environment
+  during compilation, we recommend you to use `compile_env/3` instead:
 
-      defmodule MyApp.DBClient do
-        @db_host Application.compile_env(:my_app, :db_host, "db.local")
+      @db_host Application.compile_env(:my_app, :db_host, "db.local")
 
-        def start_link() do
-          SomeLib.DBClient.start_link(host: @db_host)
-        end
-      end
-
-  The difference here is that `compile_env` expects the default value to be
-  given as an argument, instead of using the `def application` function of
-  your `mix.exs`. Furthermore, by using `compile_env/3`, tools like Mix will
-  store the values used during compilation and compare the compilation values
-  with the runtime values whenever your system starts, raising an error in
-  case they differ.
-
-  In any case, compile-time environments should be avoided. Whenever possible,
-  reading the application environment at runtime should be the first choice.
+  By using `compile_env/3`, tools like Mix will store the values used during
+  compilation and compare the compilation values with the runtime values whenever
+  your system starts, raising an error in case they differ.
 
   ## The application callback module
 
@@ -189,7 +163,7 @@ defmodule Application do
   In the sections above, we have configured an application in the
   `application/0` section of the `mix.exs` file. Ultimately, Mix will use
   this configuration to create an [*application resource
-  file*](https://www.erlang.org/doc/man/application.html), which is a file called
+  file*](https://erlang.org/doc/man/application.html), which is a file called
   `APP_NAME.app`. For example, the application resource file of the OTP
   application `ex_unit` is called `ex_unit.app`.
 
@@ -294,9 +268,9 @@ defmodule Application do
 
   For further details on applications please check the documentation of the
   [`:application` Erlang module](`:application`), and the
-  [Applications](https://www.erlang.org/doc/design_principles/applications.html)
+  [Applications](https://erlang.org/doc/design_principles/applications.html)
   section of the [OTP Design Principles User's
-  Guide](https://www.erlang.org/doc/design_principles/users_guide.html).
+  Guide](https://erlang.org/doc/design_principles/users_guide.html).
   """
 
   @doc """
@@ -411,7 +385,6 @@ defmodule Application do
     :maxT,
     :registered,
     :included_applications,
-    :optional_applications,
     :applications,
     :mod,
     :start_phases
@@ -525,34 +498,33 @@ defmodule Application do
   Giving a path is useful to let Elixir know that only certain paths
   in a large configuration are compile time dependent.
   """
+  # TODO: Warn on v1.14 if get_env/fetch_env/fetch_env! is used at
+  # compile time instead of compile_env
   @doc since: "1.10.0"
   @spec compile_env(app, key | list, value) :: value
-  defmacro compile_env(app, key_or_path, default \\ nil) do
+  defmacro compile_env(app, key_or_path, default \\ nil) when is_atom(app) do
     if __CALLER__.function do
       raise "Application.compile_env/3 cannot be called inside functions, only in the module body"
     end
 
-    key_or_path = Macro.expand_literals(key_or_path, %{__CALLER__ | function: {:__info__, 1}})
+    key_or_path = expand_key_or_path(key_or_path, __CALLER__)
 
     quote do
-      Application.compile_env(__ENV__, unquote(app), unquote(key_or_path), unquote(default))
+      Application.__compile_env__(unquote(app), unquote(key_or_path), unquote(default), __ENV__)
     end
   end
 
-  @doc """
-  Reads the application environment at compilation time from a macro.
+  defp expand_key_or_path({:__aliases__, _, _} = alias, env),
+    do: Macro.expand(alias, %{env | function: {:__info__, 1}})
 
-  Typically, developers will use `compile_env/3`. This function must
-  only be invoked from macros which aim to read the compilation environment
-  dynamically.
+  defp expand_key_or_path(list, env) when is_list(list),
+    do: Enum.map(list, &expand_key_or_path(&1, env))
 
-  It expects a `Macro.Env` as first argument, where the `Macro.Env` is
-  typically the `__CALLER__` in a macro. It raises if `Macro.Env` comes
-  from a function.
-  """
-  @doc since: "1.14.0"
-  @spec compile_env(Macro.Env.t(), app, key | list, value) :: value
-  def compile_env(%Macro.Env{} = env, app, key_or_path, default) do
+  defp expand_key_or_path(other, _env),
+    do: other
+
+  @doc false
+  def __compile_env__(app, key_or_path, default, env) do
     case fetch_compile_env(app, key_or_path, env) do
       {:ok, value} -> value
       :error -> default
@@ -567,33 +539,20 @@ defmodule Application do
   """
   @doc since: "1.10.0"
   @spec compile_env!(app, key | list) :: value
-  defmacro compile_env!(app, key_or_path) do
+  defmacro compile_env!(app, key_or_path) when is_atom(app) do
     if __CALLER__.function do
       raise "Application.compile_env!/2 cannot be called inside functions, only in the module body"
     end
 
-    key_or_path = Macro.expand_literals(key_or_path, %{__CALLER__ | function: {:__info__, 1}})
+    key_or_path = expand_key_or_path(key_or_path, __CALLER__)
 
     quote do
-      Application.compile_env!(__ENV__, unquote(app), unquote(key_or_path))
+      Application.__compile_env__!(unquote(app), unquote(key_or_path), __ENV__)
     end
   end
 
-  @doc """
-  Reads the application environment at compilation time from a macro
-  or raises.
-
-  Typically, developers will use `compile_env!/2`. This function must
-  only be invoked from macros which aim to read the compilation environment
-  dynamically.
-
-  It expects a `Macro.Env` as first argument, where the `Macro.Env` is
-  typically the `__CALLER__` in a macro. It raises if `Macro.Env` comes
-  from a function.
-  """
-  @doc since: "1.14.0"
-  @spec compile_env!(Macro.Env.t(), app, key | list) :: value
-  def compile_env!(%Macro.Env{} = env, app, key_or_path) do
+  @doc false
+  def __compile_env__!(app, key_or_path, env) do
     case fetch_compile_env(app, key_or_path, env) do
       {:ok, value} ->
         value
@@ -605,9 +564,8 @@ defmodule Application do
     end
   end
 
-  defp fetch_compile_env(app, key, env) when is_atom(key) do
-    fetch_compile_env(app, key, [], env)
-  end
+  defp fetch_compile_env(app, key, env) when is_atom(key),
+    do: fetch_compile_env(app, key, [], env)
 
   defp fetch_compile_env(app, [key | paths], env) when is_atom(key),
     do: fetch_compile_env(app, key, paths, env)
@@ -632,13 +590,14 @@ defmodule Application do
   If the configuration parameter does not exist, the function returns the
   `default` value.
 
-  > **Important:** you must use this function to read only your own application
-  > environment. Do not read the environment of other applications.
+  **Important:** if you are reading the application environment at compilation
+  time, for example, inside the module definition instead of inside of a
+  function, see `compile_env/3` instead.
 
-  > **Important:** if you are writing a library to be used by other developers,
-  > it is generally recommended to avoid the application environment, as the
-  > application environment is effectively a global storage. For more information,
-  > read our [library guidelines](library-guidelines.md).
+  **Important:** if you are writing a library to be used by other developers,
+  it is generally recommended to avoid the application environment, as the
+  application environment is effectively a global storage. For more information,
+  read our [library guidelines](library-guidelines.md).
 
   ## Examples
 
@@ -665,18 +624,10 @@ defmodule Application do
 
   Our database engine used by `:my_app` needs to know what databases exist, and
   what the database configurations are. The database engine can make a call to
-  `Application.get_env(:my_app, :my_app_databases, [])` to retrieve the list of
-  databases (specified by module names).
-
-  The engine can then traverse each repository in the list and call
-  `Application.get_env(:my_app, Databases.RepoOne)` and so forth to retrieve the
-  configuration of each one. In this case, each configuration will be a keyword
-  list, so you can use the functions in the `Keyword` module or even the `Access`
-  module to traverse it, for example:
-
-      config = Application.get_env(:my_app, Databases.RepoOne)
-      config[:ip]
-
+  `get_env(:my_app, :my_app_databases)` to retrieve the list of databases (specified
+  by module names). Our database engine can then traverse each repository in the
+  list and then call `get_env(:my_app, Databases.RepoOne)` and so forth to retrieve
+  the configuration of each one.
   """
   @spec get_env(app, key, value) :: value
   def get_env(app, key, default \\ nil) when is_atom(app) do
@@ -688,14 +639,6 @@ defmodule Application do
   Returns the value for `key` in `app`'s environment in a tuple.
 
   If the configuration parameter does not exist, the function returns `:error`.
-
-  > **Important:** you must use this function to read only your own application
-  > environment. Do not read the environment of other applications.
-
-  > **Important:** if you are writing a library to be used by other developers,
-  > it is generally recommended to avoid the application environment, as the
-  > application environment is effectively a global storage. For more information,
-  > read our [library guidelines](library-guidelines.md).
   """
   @spec fetch_env(app, key) :: {:ok, value} | :error
   def fetch_env(app, key) when is_atom(app) do
@@ -712,13 +655,9 @@ defmodule Application do
 
   If the configuration parameter does not exist, raises `ArgumentError`.
 
-  > **Important:** you must use this function to read only your own application
-  > environment. Do not read the environment of other applications.
-
-  > **Important:** if you are writing a library to be used by other developers,
-  > it is generally recommended to avoid the application environment, as the
-  > application environment is effectively a global storage. For more information,
-  > read our [library guidelines](library-guidelines.md).
+  **Important:** if you are reading the application environment at compilation
+  time, for example, inside the module definition instead of inside of a
+  function, see `compile_env!/2` instead.
   """
   @spec fetch_env!(app, key) :: value
   def fetch_env!(app, key) when is_atom(app) do
@@ -824,7 +763,7 @@ defmodule Application do
   @doc """
   Ensures the given `app` is loaded.
 
-  Same as `load/1` but returns `:ok` if the application was already
+  Same as `load/2` but returns `:ok` if the application was already
   loaded.
   """
   @doc since: "1.10.0"

lib/elixir/lib/atom.ex

@@ -56,7 +56,7 @@ defmodule Atom do
   """
   @spec to_string(atom) :: String.t()
   def to_string(atom) do
-    :erlang.atom_to_binary(atom)
+    :erlang.atom_to_binary(atom, :utf8)
   end
 
   @doc """

lib/elixir/lib/bitwise.ex

@@ -3,11 +3,31 @@ defmodule Bitwise do
   A set of functions that perform calculations on bits.
 
   All bitwise functions work only on integers; otherwise an
-  `ArithmeticError` is raised. The functions `band/2`,
-  `bor/2`, `bsl/2`, and `bsr/2` also have operators,
-  respectively: `&&&/2`, `|||/2`, `<<</2`, and `>>>/2`.
+  `ArithmeticError` is raised.
 
-  ## Guards
+  The functions in this module come in two flavors: named or
+  operators. For example:
+
+      iex> use Bitwise
+      iex> bnot(1) # named
+      -2
+      iex> 1 &&& 1 # operator
+      1
+
+  If you prefer to use only operators or skip them, you can
+  pass the following options:
+
+    * `:only_operators` - includes only operators
+    * `:skip_operators` - skips operators
+
+  For example:
+
+      iex> use Bitwise, only_operators: true
+      iex> 1 &&& 1
+      1
+
+  When invoked with no options, `use Bitwise` is equivalent
+  to `import Bitwise`.
 
   All bitwise functions can be used in guards:
 
@@ -22,7 +42,6 @@ defmodule Bitwise do
   """
 
   @doc false
-  @deprecated "import Bitwise instead"
   defmacro __using__(options) do
     except =
       cond do
@@ -30,7 +49,7 @@ defmodule Bitwise do
           [bnot: 1, band: 2, bor: 2, bxor: 2, bsl: 2, bsr: 2]
 
         Keyword.get(options, :skip_operators) ->
-          ["~~~": 1, &&&: 2, |||: 2, "^^^": 2, <<<: 2, >>>: 2]
+          [~~~: 1, &&&: 2, |||: 2, ^^^: 2, <<<: 2, >>>: 2]
 
         true ->
           []
@@ -61,8 +80,25 @@ defmodule Bitwise do
     :erlang.bnot(expr)
   end
 
-  @doc false
-  def unquote(:"~~~")(expr) do
+  @doc """
+  Bitwise NOT unary operator.
+
+  Calculates the bitwise NOT of the argument.
+
+  Allowed in guard tests. Inlined by the compiler.
+
+  ## Examples
+
+      iex> ~~~2
+      -3
+
+      iex> ~~~2 &&& 3
+      1
+
+  """
+  @doc guard: true
+  @spec ~~~integer :: integer
+  def ~~~expr do
     :erlang.bnot(expr)
   end
 
@@ -156,7 +192,7 @@ defmodule Bitwise do
   end
 
   @doc false
-  def unquote(:"^^^")(left, right) do
+  def unquote(:^^^)(left, right) do
     :erlang.bxor(left, right)
   end
 

lib/elixir/lib/calendar.ex

@@ -57,7 +57,7 @@ defmodule Calendar do
   representing the microseconds to external format. If the precision is 0,
   it means microseconds must be skipped.
   """
-  @type microsecond :: {value :: non_neg_integer, precision :: non_neg_integer}
+  @type microsecond :: {non_neg_integer, non_neg_integer}
 
   @typedoc "A calendar implementation"
   @type calendar :: module
@@ -189,7 +189,7 @@ defmodule Calendar do
   @doc """
   Calculates the year and era from the given `year`.
   """
-  @callback year_of_era(year, month, day) :: {year, era}
+  @callback year_of_era(year) :: {year, era}
 
   @doc """
   Calculates the day and era from the given `year`, `month`, and `day`.
@@ -365,7 +365,7 @@ defmodule Calendar do
   """
   @doc since: "1.8.0"
   @spec put_time_zone_database(time_zone_database()) :: :ok
-  def put_time_zone_database(database) when is_atom(database) do
+  def put_time_zone_database(database) do
     Application.put_env(:elixir, :time_zone_database, database)
   end
 
@@ -375,7 +375,7 @@ defmodule Calendar do
   @doc since: "1.8.0"
   @spec get_time_zone_database() :: time_zone_database()
   def get_time_zone_database() do
-    Application.fetch_env!(:elixir, :time_zone_database)
+    Application.get_env(:elixir, :time_zone_database, Calendar.UTCOnlyTimeZoneDatabase)
   end
 
   @doc """
@@ -544,8 +544,8 @@ defmodule Calendar do
     parse_modifiers(rest, width, "", parser_data)
   end
 
-  defp parse_modifiers("0" <> rest, nil, nil, parser_data) do
-    parse_modifiers(rest, nil, ?0, parser_data)
+  defp parse_modifiers("0" <> rest, width, nil, parser_data) do
+    parse_modifiers(rest, width, ?0, parser_data)
   end
 
   defp parse_modifiers("_" <> rest, width, nil, parser_data) do

lib/elixir/lib/calendar/date.ex

@@ -4,7 +4,7 @@ defmodule Date do
 
   The Date struct contains the fields year, month, day and calendar.
   New dates can be built with the `new/3` function or using the
-  `~D` (see `sigil_D/2`) sigil:
+  `~D` (see `Kernel.sigil_D/2`) sigil:
 
       iex> ~D[2000-01-01]
       ~D[2000-01-01]
@@ -31,12 +31,7 @@ defmodule Date do
 
   Comparisons in Elixir using `==/2`, `>/2`, `</2` and similar are structural
   and based on the `Date` struct fields. For proper comparison between
-  dates, use the `compare/2` function. The existence of the `compare/2`
-  function in this module also allows using `Enum.min/2` and `Enum.max/2`
-  functions to get the minimum and maximum date of an `Enum`. For example:
-
-      iex>  Enum.min([~D[2017-03-31], ~D[2017-04-01]], Date)
-      ~D[2017-03-31]
+  dates, use the `compare/2` function.
 
   ## Using epochs
 
@@ -77,18 +72,16 @@ defmodule Date do
   ## Examples
 
       iex> Date.range(~D[1999-01-01], ~D[2000-01-01])
-      Date.range(~D[1999-01-01], ~D[2000-01-01])
+      #DateRange<~D[1999-01-01], ~D[2000-01-01]>
 
   A range of dates implements the `Enumerable` protocol, which means
   functions in the `Enum` module can be used to work with
   ranges:
 
       iex> range = Date.range(~D[2001-01-01], ~D[2002-01-01])
-      iex> range
-      Date.range(~D[2001-01-01], ~D[2002-01-01])
       iex> Enum.count(range)
       366
-      iex> ~D[2001-02-01] in range
+      iex> Enum.member?(range, ~D[2001-02-01])
       true
       iex> Enum.take(range, 3)
       [~D[2001-01-01], ~D[2001-01-02], ~D[2001-01-03]]
@@ -115,10 +108,10 @@ defmodule Date do
 
       iex> range = Date.range(~D[2001-01-01], ~D[2002-01-01], 2)
       iex> range
-      Date.range(~D[2001-01-01], ~D[2002-01-01], 2)
+      #DateRange<~D[2001-01-01], ~D[2002-01-01], 2>
       iex> Enum.count(range)
       183
-      iex> ~D[2001-01-03] in range
+      iex> Enum.member?(range, ~D[2001-01-03])
       true
       iex> Enum.take(range, 3)
       [~D[2001-01-01], ~D[2001-01-03], ~D[2001-01-05]]
@@ -837,6 +830,8 @@ defmodule Date do
       ~D[2020-07-05]
       iex> Date.end_of_week(~D[2020-07-06], :sunday)
       ~D[2020-07-11]
+      iex> Date.end_of_week(~D[2020-07-06], :sunday)
+      ~D[2020-07-11]
       iex> Date.end_of_week(~D[2020-07-06], :saturday)
       ~D[2020-07-10]
       iex> Date.end_of_week(~N[2020-07-11 01:23:45])
@@ -948,14 +943,8 @@ defmodule Date do
   @spec year_of_era(Calendar.date()) :: {Calendar.year(), non_neg_integer()}
   def year_of_era(date)
 
-  def year_of_era(%{calendar: calendar, year: year, month: month, day: day}) do
-    # TODO: Remove me on 1.17
-    # The behaviour implementation already warns on missing callback.
-    if function_exported?(calendar, :year_of_era, 3) do
-      calendar.year_of_era(year, month, day)
-    else
-      calendar.year_of_era(year)
-    end
+  def year_of_era(%{calendar: calendar, year: year}) do
+    calendar.year_of_era(year)
   end
 
   @doc """
@@ -997,8 +986,6 @@ defmodule Date do
   """
   @doc since: "1.11.0"
   @spec beginning_of_month(Calendar.date()) :: t()
-  def beginning_of_month(date)
-
   def beginning_of_month(%{year: year, month: month, calendar: calendar}) do
     %Date{year: year, month: month, day: 1, calendar: calendar}
   end
@@ -1018,8 +1005,6 @@ defmodule Date do
   """
   @doc since: "1.11.0"
   @spec end_of_month(Calendar.date()) :: t()
-  def end_of_month(date)
-
   def end_of_month(%{year: year, month: month, calendar: calendar} = date) do
     day = Date.days_in_month(date)
     %Date{year: year, month: month, day: day, calendar: calendar}

lib/elixir/lib/calendar/date_range.ex

@@ -16,14 +16,13 @@ defmodule Date.Range do
   @type t :: %__MODULE__{
           first: Date.t(),
           last: Date.t(),
-          first_in_iso_days: days(),
-          last_in_iso_days: days(),
+          first_in_iso_days: iso_days(),
+          last_in_iso_days: iso_days(),
           step: pos_integer | neg_integer
         }
 
-  @typep days() :: integer()
+  @typep iso_days() :: Calendar.iso_days()
 
-  @enforce_keys [:first, :last, :first_in_iso_days, :last_in_iso_days, :step]
   defstruct [:first, :last, :first_in_iso_days, :last_in_iso_days, :step]
 
   defimpl Enumerable do
@@ -75,7 +74,7 @@ defmodule Date.Range do
             step: step
           } = range
         ) do
-      {:ok, size(range), &slice(first + &1 * step, step + &3 - 1, &2, calendar)}
+      {:ok, size(range), &slice(first + &1 * step, step, &2, calendar)}
     end
 
     # TODO: Remove me on v2.0
@@ -211,11 +210,11 @@ defmodule Date.Range do
     import Kernel, except: [inspect: 2]
 
     def inspect(%Date.Range{first: first, last: last, step: 1}, _) do
-      "Date.range(" <> inspect(first) <> ", " <> inspect(last) <> ")"
+      "#DateRange<" <> inspect(first) <> ", " <> inspect(last) <> ">"
     end
 
     def inspect(%Date.Range{first: first, last: last, step: step}, _) do
-      "Date.range(" <> inspect(first) <> ", " <> inspect(last) <> ", #{step})"
+      "#DateRange<" <> inspect(first) <> ", " <> inspect(last) <> ", #{step}>"
     end
 
     # TODO: Remove me on v2.0

lib/elixir/lib/calendar/datetime.ex

@@ -2,24 +2,15 @@ defmodule DateTime do
   @moduledoc """
   A datetime implementation with a time zone.
 
-  This datetime can be seen as a snapshot of a date and time
-  at a given time zone. For such purposes, it also includes both
-  UTC and Standard offsets, as well as the zone abbreviation
-  field used exclusively for formatting purposes. Note future
-  datetimes are not necessarily guaranteed to exist, as time
-  zones may change any time in the future due to geopolitical
-  reasons. See the "Datetimes as snapshots" section for more
-  information.
+  This datetime can be seen as an ephemeral snapshot
+  of a datetime at a given time zone. For such purposes,
+  it also includes both UTC and Standard offsets, as
+  well as the zone abbreviation field used exclusively
+  for formatting purposes.
 
   Remember, comparisons in Elixir using `==/2`, `>/2`, `</2` and friends
   are structural and based on the DateTime struct fields. For proper
-  comparison between datetimes, use the `compare/2` function. The
-  existence of the `compare/2` function in this module also allows
-  using `Enum.min/2` and `Enum.max/2` functions to get the minimum and
-  maximum datetime of an `Enum`. For example:
-
-      iex> Enum.min([~U[2022-01-12 00:01:00.00Z], ~U[2021-01-12 00:01:00.00Z]], DateTime)
-      ~U[2021-01-12 00:01:00.00Z]
+  comparison between datetimes, use the `compare/2` function.
 
   Developers should avoid creating the `DateTime` struct directly
   and instead rely on the functions provided by this module as
@@ -34,74 +25,22 @@ defmodule DateTime do
   datetimes and returns `{:error, :utc_only_time_zone_database}`
   for any other time zone.
 
-  Other time zone databases can also be configured. Here are some
-  available options and libraries:
+  Other time zone databases can also be configured. For example,
+  two of the available options are:
 
-    * [`tz`](https://github.com/mathieuprog/tz)
-    * [`tzdata`](https://github.com/lau/tzdata)
-    * [`zoneinfo`](https://github.com/smartrent/zoneinfo) -
-      recommended for embedded devices
+    * [`tz`](https://hexdocs.pm/tz/)
+    * [`tzdata`](https://hexdocs.pm/tzdata/)
 
   To use them, first make sure it is added as a dependency in `mix.exs`.
   It can then be configured either via configuration:
 
-      config :elixir, :time_zone_database, Tz.TimeZoneDatabase
+      config :elixir, :time_zone_database, Tzdata.TimeZoneDatabase
 
   or by calling `Calendar.put_time_zone_database/1`:
 
-      Calendar.put_time_zone_database(Tz.TimeZoneDatabase)
+      Calendar.put_time_zone_database(Tzdata.TimeZoneDatabase)
 
   See the proper names in the library installation instructions.
-
-  ## Datetimes as snapshots
-
-  In the first section, we described datetimes as a "snapshot of
-  a date and time at a given time zone". To understand precisely
-  what we mean, let's see an example.
-
-  Imagine someone in Poland wants to schedule a meeting with someone
-  in Brazil in the next year. The meeting will happen at 2:30 AM
-  in the Polish time zone. At what time will the meeting happen in
-  Brazil?
-
-  You can consult the time zone database today, one year before,
-  using the API in this module and it will give you an answer that
-  is valid right now. However, this answer may not be valid in the
-  future. Why? Because both Brazil and Poland may change their timezone
-  rules, ultimately affecting the result. For example, a country may
-  choose to enter or abandon "Daylight Saving Time", which is a
-  process where we adjust the clock one hour forward or one hour
-  back once per year. Whenener the rules change, the exact instant
-  that 2:30 AM in Polish time will be in Brazil may change.
-
-  In other words, whenever working with future DateTimes, there is
-  no guarantee the results you get will always be correct, until
-  the event actually happens. Therefore, when you ask for a future
-  time, the answers you get are a snapshot that reflects the current
-  state of the time zone rules. For datetimes in the past, this is
-  not a problem, because time zone rules do not change for past
-  events.
-
-  To make matters worse, it may be that the 2:30 AM in Polish time
-  does not actually even exist or it is ambiguous. If a certain
-  time zone observes "Daylight Saving Time", they will move their
-  clock forward once a year. When this happens, there is a whole
-  hour that does not exist. Then, when they move the clock back,
-  there is a certain hour that will happen twice. So if you want
-  to schedule a meeting when this shift back happens, you would
-  need to explicitly say which of the 2:30 AM you precisely mean.
-  Applications that are date and time sensitive, need to take
-  these scenarios into account and correctly communicate them to
-  users.
-
-  The good news is: Elixir contains all of the building blocks
-  necessary to tackle those problems. The default timezone database
-  used by Elixir, `Calendar.UTCOnlyTimeZoneDatabase`, only works
-  with UTC, which does not observe those issues. Once you bring
-  a proper time zone database, the functions in this module will
-  query the database and return the relevant information. For
-  example, look at how `DateTime.new/4` returns different results
-  based on the scenarios described in this section.
   """
 
   @enforce_keys [:year, :month, :day, :hour, :minute, :second] ++
@@ -143,9 +82,6 @@ defmodule DateTime do
   @doc """
   Returns the current datetime in UTC.
 
-  If you want the current time in Unix seconds,
-  use `System.os_time/1` instead.
-
   ## Examples
 
       iex> datetime = DateTime.utc_now()
@@ -514,7 +450,7 @@ defmodule DateTime do
         # we get the last microsecond just before.
         before_naive =
           first_period_until_wall
-          |> Map.replace!(:microsecond, {999_999, 6})
+          |> Map.put(:microsecond, {999_999, 6})
           |> NaiveDateTime.add(-1)
 
         after_naive = second_period_from_wall
@@ -817,6 +753,10 @@ defmodule DateTime do
   It will return the integer with the given unit,
   according to `System.convert_time_unit/3`.
 
+  If you want to get the current time in Unix seconds,
+  do not do `DateTime.utc_now() |> DateTime.to_unix()`.
+  Simply call `System.os_time(:second)` instead.
+
   ## Examples
 
       iex> 1_464_096_368 |> DateTime.from_unix!() |> DateTime.to_unix()
@@ -861,8 +801,6 @@ defmodule DateTime do
 
   """
   @spec to_naive(Calendar.datetime()) :: NaiveDateTime.t()
-  def to_naive(datetime)
-
   def to_naive(%{
         calendar: calendar,
         year: year,
@@ -902,8 +840,6 @@ defmodule DateTime do
 
   """
   @spec to_date(Calendar.datetime()) :: Date.t()
-  def to_date(datetime)
-
   def to_date(%{
         year: year,
         month: month,
@@ -934,8 +870,6 @@ defmodule DateTime do
 
   """
   @spec to_time(Calendar.datetime()) :: Time.t()
-  def to_time(datetime)
-
   def to_time(%{
         year: _,
         month: _,
@@ -1119,10 +1053,6 @@ defmodule DateTime do
       iex> datetime
       ~U[-2015-01-23 21:20:07.123Z]
 
-      iex> {:ok, datetime, 9000} = DateTime.from_iso8601("20150123T235007.123+0230", :basic)
-      iex> datetime
-      ~U[2015-01-23 21:20:07.123Z]
-
       iex> DateTime.from_iso8601("2015-01-23P23:50:07")
       {:error, :invalid_format}
       iex> DateTime.from_iso8601("2015-01-23T23:50:07")
@@ -1136,37 +1066,11 @@ defmodule DateTime do
 
   """
   @doc since: "1.4.0"
-  @spec from_iso8601(String.t(), Calendar.calendar(), :extended | :basic) ::
+  @spec from_iso8601(String.t(), Calendar.calendar()) ::
           {:ok, t, Calendar.utc_offset()} | {:error, atom}
-
-  def from_iso8601(string, format_or_calendar \\ Calendar.ISO)
-
-  def from_iso8601(string, format) when format in [:basic, :extended] do
-    from_iso8601(string, Calendar.ISO, format)
-  end
-
-  def from_iso8601(string, calendar) when is_atom(calendar) do
-    from_iso8601(string, calendar, :extended)
-  end
-
-  @doc """
-  Converts to ISO8601 specifying both a calendar and a mode.
-
-  See `from_iso8601/2` for more information.
-
-  ## Examples
-
-      iex> {:ok, datetime, 9000} = DateTime.from_iso8601("2015-01-23T23:50:07,123+02:30", Calendar.ISO, :extended)
-      iex> datetime
-      ~U[2015-01-23 21:20:07.123Z]
-
-      iex> {:ok, datetime, 9000} = DateTime.from_iso8601("20150123T235007.123+0230", Calendar.ISO, :basic)
-      iex> datetime
-      ~U[2015-01-23 21:20:07.123Z]
-  """
-  def from_iso8601(string, calendar, format) do
+  def from_iso8601(string, calendar \\ Calendar.ISO) do
     with {:ok, {year, month, day, hour, minute, second, microsecond}, offset} <-
-           Calendar.ISO.parse_utc_datetime(string, format) do
+           Calendar.ISO.parse_utc_datetime(string) do
       datetime = %DateTime{
         year: year,
         month: month,
@@ -1387,11 +1291,12 @@ defmodule DateTime do
   @doc """
   Subtracts `datetime2` from `datetime1`.
 
-  The answer can be returned in any `:day`, `:hour`, `:minute`, or any `unit`
-  available from `t:System.time_unit/0`. The unit is measured according to
-  `Calendar.ISO` and defaults to `:second`.
+  The answer can be returned in any `unit` available from `t:System.time_unit/0`.
 
-  Fractional results are not supported and are truncated.
+  Leap seconds are not taken into account.
+
+  This function returns the difference in seconds where seconds are measured
+  according to `Calendar.ISO`.
 
   ## Examples
 
@@ -1405,36 +1310,14 @@ defmodule DateTime do
       18000
       iex> DateTime.diff(dt2, dt1)
       -18000
-      iex> DateTime.diff(dt1, dt2, :hour)
-      5
-      iex> DateTime.diff(dt2, dt1, :hour)
-      -5
 
   """
   @doc since: "1.5.0"
-  @spec diff(
-          Calendar.datetime(),
-          Calendar.datetime(),
-          :day | :hour | :minute | System.time_unit()
-        ) :: integer()
-  def diff(datetime1, datetime2, unit \\ :second)
-
-  def diff(datetime1, datetime2, :day) do
-    diff(datetime1, datetime2, :second) |> div(86400)
-  end
-
-  def diff(datetime1, datetime2, :hour) do
-    diff(datetime1, datetime2, :second) |> div(3600)
-  end
-
-  def diff(datetime1, datetime2, :minute) do
-    diff(datetime1, datetime2, :second) |> div(60)
-  end
-
+  @spec diff(Calendar.datetime(), Calendar.datetime(), System.time_unit()) :: integer()
   def diff(
         %{utc_offset: utc_offset1, std_offset: std_offset1} = datetime1,
         %{utc_offset: utc_offset2, std_offset: std_offset2} = datetime2,
-        unit
+        unit \\ :second
       ) do
     naive_diff =
       (datetime1 |> to_iso_days() |> Calendar.ISO.iso_days_to_unit(unit)) -
@@ -1447,30 +1330,15 @@ defmodule DateTime do
   @doc """
   Adds a specified amount of time to a `DateTime`.
 
-  Accepts an `amount_to_add` in any `unit`. `unit` can be `:day`,
-  `:hour`, `:minute`, `:second` or any subsecond precision from
-  `t:System.time_unit/0`. It defaults to `:second`. Negative values
-  will move backwards in time.
+  Accepts an `amount_to_add` in any `unit` available from `t:System.time_unit/0`.
+  Negative values will move backwards in time.
 
-  This function always consider the unit to be computed according
-  to the `Calendar.ISO`.
+  Takes changes such as summer time/DST into account. This means that adding time
+  can cause the wall time to "go backwards" during "fall back" during autumn.
+  Adding just a few seconds to a datetime just before "spring forward" can cause wall
+  time to increase by more than an hour.
 
-  This function uses relies on a contiguous representation of time,
-  ignoring the wall time and timezone changes. For example, if you add
-  one day when there are summer time/daylight saving time changes,
-  it will also change the time forward or backward by one hour,
-  so the ellapsed time is precisely 24 hours. Similarly, adding just
-  a few seconds to a datetime just before "spring forward" can cause
-  wall time to increase by more than an hour.
-
-  While this means this function is precise in terms of ellapsed time,
-  its result may be misleading in certain use cases. For example, if a
-  user requests a meeting to happen every day at 15:00 and you use this
-  function to compute all future meetings by adding day after day, this
-  function may change the meeting time to 14:00 or 16:00 if there are
-  changes to the current timezone. Computing of recurring datetimes is
-  not currently supported in Elixir's standard library but it is available
-  by third-party libraries.
+  Fractional second precision stays the same in a similar way to `NaiveDateTime.add/2`.
 
   ### Examples
 
@@ -1481,26 +1349,15 @@ defmodule DateTime do
       iex> DateTime.add(~U[2018-11-15 10:00:00Z], 3600, :second)
       ~U[2018-11-15 11:00:00Z]
 
-  When adding 3 seconds just before "spring forward" we go from 1:59:59 to 3:00:02:
+  When adding 3 seconds just before "spring forward" we go from 1:59:59 to 3:00:02
 
       iex> dt = DateTime.from_naive!(~N[2019-03-31 01:59:59.123], "Europe/Copenhagen", FakeTimeZoneDatabase)
       iex> dt |> DateTime.add(3, :second, FakeTimeZoneDatabase)
       #DateTime<2019-03-31 03:00:02.123+02:00 CEST Europe/Copenhagen>
 
-  When adding 1 day during "spring forward", the hour also changes:
-
-      iex> dt = DateTime.from_naive!(~N[2019-03-31 01:00:00], "Europe/Copenhagen", FakeTimeZoneDatabase)
-      iex> dt |> DateTime.add(1, :day, FakeTimeZoneDatabase)
-      #DateTime<2019-04-01 02:00:00+02:00 CEST Europe/Copenhagen>
-
   """
   @doc since: "1.8.0"
-  @spec add(
-          Calendar.datetime(),
-          integer,
-          :day | :hour | :minute | System.time_unit(),
-          Calendar.time_zone_database()
-        ) ::
+  @spec add(Calendar.datetime(), integer, System.time_unit(), Calendar.time_zone_database()) ::
           t()
   def add(
         datetime,
@@ -1508,20 +1365,7 @@ defmodule DateTime do
         unit \\ :second,
         time_zone_database \\ Calendar.get_time_zone_database()
       )
-
-  def add(datetime, amount_to_add, :day, time_zone_database) when is_integer(amount_to_add) do
-    add(datetime, amount_to_add * 86400, :second, time_zone_database)
-  end
-
-  def add(datetime, amount_to_add, :hour, time_zone_database) when is_integer(amount_to_add) do
-    add(datetime, amount_to_add * 3600, :second, time_zone_database)
-  end
-
-  def add(datetime, amount_to_add, :minute, time_zone_database) when is_integer(amount_to_add) do
-    add(datetime, amount_to_add * 60, :second, time_zone_database)
-  end
-
-  def add(datetime, amount_to_add, unit, time_zone_database) when is_integer(amount_to_add) do
+      when is_integer(amount_to_add) do
     %{
       utc_offset: utc_offset,
       std_offset: std_offset,
@@ -1529,12 +1373,6 @@ defmodule DateTime do
       microsecond: {_, precision}
     } = datetime
 
-    if not is_integer(unit) and
-         unit not in ~w(second millisecond microsecond nanosecond)a do
-      raise ArgumentError,
-            "unsupported time unit. Expected :day, :hour, :minute, :second, :millisecond, :microsecond, :nanosecond, or a positive integer, got #{inspect(unit)}"
-    end
-
     ppd = System.convert_time_unit(86400, :second, unit)
     total_offset = System.convert_time_unit(utc_offset + std_offset, :second, unit)
 

lib/elixir/lib/calendar/iso.ex

@@ -131,8 +131,6 @@ defmodule Calendar.ISO do
   unix_end = 315_569_519_999_999_999 - @unix_epoch * 1_000_000
   @unix_range_microseconds unix_start..unix_end
 
-  defguardp is_format(term) when term in [:basic, :extended]
-
   @typedoc """
   "Before the Current Era" or "Before the Common Era" (BCE), for those years less than `1`.
   """
@@ -158,8 +156,6 @@ defmodule Calendar.ISO do
   @type minute :: 0..59
   @type second :: 0..59
   @type weekday :: :monday | :tuesday | :wednesday | :thursday | :friday | :saturday | :sunday
-  @type utc_offset :: integer
-  @type format :: :basic | :extended
 
   @typedoc """
   Microseconds with stored precision.
@@ -266,9 +262,6 @@ defmodule Calendar.ISO do
   """
   @doc since: "1.10.0"
   @impl true
-  @spec parse_time(String.t()) ::
-          {:ok, {hour, minute, second, microsecond}}
-          | {:error, atom}
   def parse_time(string) when is_binary(string),
     do: parse_time(string, :extended)
 
@@ -289,15 +282,11 @@ defmodule Calendar.ISO do
 
   """
   @doc since: "1.12.0"
-  @spec parse_time(String.t(), format) ::
-          {:ok, {hour, minute, second, microsecond}}
-          | {:error, atom}
-  def parse_time(string, format) when is_binary(string) and is_format(format) do
-    case string do
-      "T" <> rest -> do_parse_time(rest, format)
-      _ -> do_parse_time(string, format)
-    end
-  end
+  def parse_time("T" <> string, format) when is_binary(string),
+    do: do_parse_time(string, format)
+
+  def parse_time(string, format) when is_binary(string),
+    do: do_parse_time(string, format)
 
   defp do_parse_time(<<unquote(match_basic_time), rest::binary>>, :basic)
        when unquote(guard_time) do
@@ -347,9 +336,6 @@ defmodule Calendar.ISO do
   """
   @doc since: "1.10.0"
   @impl true
-  @spec parse_date(String.t()) ::
-          {:ok, {year, month, day}}
-          | {:error, atom}
   def parse_date(string) when is_binary(string),
     do: parse_date(string, :extended)
 
@@ -370,19 +356,13 @@ defmodule Calendar.ISO do
 
   """
   @doc since: "1.12.0"
-  @spec parse_date(String.t(), format) ::
-          {:ok, {year, month, day}}
-          | {:error, atom}
-  def parse_date(string, format) when is_binary(string) and is_format(format),
-    do: parse_date_guarded(string, format)
-
-  defp parse_date_guarded("-" <> string, format),
+  def parse_date("-" <> string, format) when is_binary(string),
     do: do_parse_date(string, -1, format)
 
-  defp parse_date_guarded("+" <> string, format),
+  def parse_date("+" <> string, format) when is_binary(string),
     do: do_parse_date(string, 1, format)
 
-  defp parse_date_guarded(string, format),
+  def parse_date(string, format) when is_binary(string),
     do: do_parse_date(string, 1, format)
 
   defp do_parse_date(unquote(match_basic_date), multiplier, :basic) when unquote(guard_date) do
@@ -432,9 +412,6 @@ defmodule Calendar.ISO do
   """
   @doc since: "1.10.0"
   @impl true
-  @spec parse_naive_datetime(String.t()) ::
-          {:ok, {year, month, day, hour, minute, second, microsecond}}
-          | {:error, atom}
   def parse_naive_datetime(string) when is_binary(string),
     do: parse_naive_datetime(string, :extended)
 
@@ -455,19 +432,13 @@ defmodule Calendar.ISO do
 
   """
   @doc since: "1.12.0"
-  @spec parse_naive_datetime(String.t(), format) ::
-          {:ok, {year, month, day, hour, minute, second, microsecond}}
-          | {:error, atom}
-  def parse_naive_datetime(string, format) when is_binary(string) and is_format(format),
-    do: parse_naive_datetime_guarded(string, format)
-
-  defp parse_naive_datetime_guarded("-" <> string, format),
+  def parse_naive_datetime("-" <> string, format) when is_binary(string),
     do: do_parse_naive_datetime(string, -1, format)
 
-  defp parse_naive_datetime_guarded("+" <> string, format),
+  def parse_naive_datetime("+" <> string, format) when is_binary(string),
     do: do_parse_naive_datetime(string, 1, format)
 
-  defp parse_naive_datetime_guarded(string, format),
+  def parse_naive_datetime(string, format) when is_binary(string),
     do: do_parse_naive_datetime(string, 1, format)
 
   defp do_parse_naive_datetime(
@@ -536,9 +507,6 @@ defmodule Calendar.ISO do
   """
   @doc since: "1.10.0"
   @impl true
-  @spec parse_utc_datetime(String.t()) ::
-          {:ok, {year, month, day, hour, minute, second, microsecond}, utc_offset}
-          | {:error, atom}
   def parse_utc_datetime(string) when is_binary(string),
     do: parse_utc_datetime(string, :extended)
 
@@ -559,19 +527,13 @@ defmodule Calendar.ISO do
 
   """
   @doc since: "1.12.0"
-  @spec parse_utc_datetime(String.t(), format) ::
-          {:ok, {year, month, day, hour, minute, second, microsecond}, utc_offset}
-          | {:error, atom}
-  def parse_utc_datetime(string, format) when is_binary(string) and is_format(format),
-    do: parse_utc_datetime_guarded(string, format)
-
-  defp parse_utc_datetime_guarded("-" <> string, format),
+  def parse_utc_datetime("-" <> string, format) when is_binary(string),
     do: do_parse_utc_datetime(string, -1, format)
 
-  defp parse_utc_datetime_guarded("+" <> string, format),
+  def parse_utc_datetime("+" <> string, format) when is_binary(string),
     do: do_parse_utc_datetime(string, 1, format)
 
-  defp parse_utc_datetime_guarded(string, format),
+  def parse_utc_datetime(string, format) when is_binary(string),
     do: do_parse_utc_datetime(string, 1, format)
 
   defp do_parse_utc_datetime(
@@ -1023,33 +985,14 @@ defmodule Calendar.ISO do
   """
   @doc since: "1.8.0"
   @spec year_of_era(year) :: {1..10000, era}
-  def year_of_era(year) when is_year_CE(year), do: {year, 1}
-  def year_of_era(year) when is_year_BCE(year), do: {abs(year) + 1, 0}
-
-  @doc """
-  Calendar callback to compute the year and era from the
-  given `year`, `month` and `day`.
-
-  In the ISO calendar, the new year coincides with the new era,
-  so the `month` and `day` arguments are discarded. If you only
-  have the year available, you can `year_of_era/1` instead.
-
-  ## Examples
-
-      iex> Calendar.ISO.year_of_era(1, 1, 1)
-      {1, 1}
-      iex> Calendar.ISO.year_of_era(2018, 12, 1)
-      {2018, 1}
-      iex> Calendar.ISO.year_of_era(0, 1, 1)
-      {1, 0}
-      iex> Calendar.ISO.year_of_era(-1, 12, 1)
-      {2, 0}
-
-  """
-  @doc since: "1.13.0"
   @impl true
-  @spec year_of_era(year, month, day) :: {1..10000, era}
-  def year_of_era(year, _month, _day), do: year_of_era(year)
+  def year_of_era(year) when is_year_CE(year) do
+    {year, 1}
+  end
+
+  def year_of_era(year) when is_year_BCE(year) do
+    {abs(year) + 1, 0}
+  end
 
   @doc """
   Calculates the day and era from the given `year`, `month`, and `day`.

lib/elixir/lib/calendar/naive_datetime.ex

@@ -5,7 +5,7 @@ defmodule NaiveDateTime do
   The NaiveDateTime struct contains the fields year, month, day, hour,
   minute, second, microsecond and calendar. New naive datetimes can be
   built with the `new/2` and `new/8` functions or using the
-  `~N` (see `sigil_N/2`) sigil:
+  `~N` (see `Kernel.sigil_N/2`) sigil:
 
       iex> ~N[2000-01-01 23:00:07]
       ~N[2000-01-01 23:00:07]
@@ -36,18 +36,12 @@ defmodule NaiveDateTime do
 
   Comparisons in Elixir using `==/2`, `>/2`, `</2` and similar are structural
   and based on the `NaiveDateTime` struct fields. For proper comparison
-  between naive datetimes, use the `compare/2` function. The existence of the
-  `compare/2` function in this module also allows using `Enum.min/2` and
-  `Enum.max/2` functions to get the minimum and maximum naive datetime of an
-  `Enum`. For example:
-
-      iex> Enum.min([~N[2020-01-01 23:00:07], ~N[2000-01-01 23:00:07]], NaiveDateTime)
-      ~N[2000-01-01 23:00:07]
+  between naive datetimes, use the `compare/2` function.
 
   ## Using epochs
 
-  The `add/3` and `diff/3` functions can be used for computing date
-  times or retrieving the number of seconds between instants.
+  The `add/3` and `diff/3` functions can be used for computing with
+  date times or retrieving the number of seconds between instants.
   For example, if there is an interest in computing the number of
   seconds from the Unix epoch (1970-01-01 00:00:00):
 
@@ -356,18 +350,11 @@ defmodule NaiveDateTime do
   @doc """
   Adds a specified amount of time to a `NaiveDateTime`.
 
-  Accepts an `amount_to_add` in any `unit`. `unit` can be `:day`,
-  `:hour`, `:minute`, `:second` or any subsecond precision from
-  `t:System.time_unit/0`. It defaults to `:second`. Negative values
-  will move backwards in time.
-
-  This function always consider the unit to be computed according
-  to the `Calendar.ISO`.
+  Accepts an `amount_to_add` in any `unit` available from `t:System.time_unit/0`.
+  Negative values will move backwards in time.
 
   ## Examples
 
-  It uses seconds by default:
-
       # adds seconds by default
       iex> NaiveDateTime.add(~N[2014-10-02 00:29:10], 2)
       ~N[2014-10-02 00:29:12]
@@ -376,33 +363,19 @@ defmodule NaiveDateTime do
       iex> NaiveDateTime.add(~N[2014-10-02 00:29:10], -2)
       ~N[2014-10-02 00:29:08]
 
-  It can also work with subsecond precisions:
-
+      # can work with other units
       iex> NaiveDateTime.add(~N[2014-10-02 00:29:10], 2_000, :millisecond)
       ~N[2014-10-02 00:29:12]
 
-  As well as days/hours/minutes:
-
-      iex> NaiveDateTime.add(~N[2015-02-28 00:29:10], 2, :day)
-      ~N[2015-03-02 00:29:10]
-      iex> NaiveDateTime.add(~N[2015-02-28 00:29:10], 36, :hour)
-      ~N[2015-03-01 12:29:10]
-      iex> NaiveDateTime.add(~N[2015-02-28 00:29:10], 60, :minute)
-      ~N[2015-02-28 01:29:10]
-
-  This operation keeps the precision of the naive date time:
-
+      # keeps the same precision
       iex> NaiveDateTime.add(~N[2014-10-02 00:29:10.021], 21, :second)
       ~N[2014-10-02 00:29:31.021]
 
-  And ignores any changes below the precision:
-
+      # changes below the precision will not be visible
       iex> hidden = NaiveDateTime.add(~N[2014-10-02 00:29:10], 21, :millisecond)
       iex> hidden.microsecond # ~N[2014-10-02 00:29:10]
       {21000, 0}
 
-  Operations on top of gregorian seconds or the Unix epoch are optimized:
-
       # from Gregorian seconds
       iex> NaiveDateTime.add(~N[0000-01-01 00:00:00], 63_579_428_950)
       ~N[2014-10-02 00:29:10]
@@ -418,25 +391,11 @@ defmodule NaiveDateTime do
 
   """
   @doc since: "1.4.0"
-  @spec add(Calendar.naive_datetime(), integer, :day | :hour | :minute | System.time_unit()) :: t
-  def add(naive_datetime, amount_to_add, unit \\ :second)
-
-  def add(naive_datetime, amount_to_add, :day) when is_integer(amount_to_add) do
-    add(naive_datetime, amount_to_add * 86400, :second)
-  end
-
-  def add(naive_datetime, amount_to_add, :hour) when is_integer(amount_to_add) do
-    add(naive_datetime, amount_to_add * 3600, :second)
-  end
-
-  def add(naive_datetime, amount_to_add, :minute) when is_integer(amount_to_add) do
-    add(naive_datetime, amount_to_add * 60, :second)
-  end
-
+  @spec add(Calendar.naive_datetime(), integer, System.time_unit()) :: t
   def add(
         %{microsecond: {_, precision}, calendar: calendar} = naive_datetime,
         amount_to_add,
-        unit
+        unit \\ :second
       )
       when is_integer(amount_to_add) do
     ppd = System.convert_time_unit(86400, :second, unit)
@@ -450,11 +409,10 @@ defmodule NaiveDateTime do
   @doc """
   Subtracts `naive_datetime2` from `naive_datetime1`.
 
-  The answer can be returned in any `:day`, `:hour`, `:minute`, or any `unit`
-  available from `t:System.time_unit/0`. The unit is measured according to
-  `Calendar.ISO` and defaults to `:second`.
+  The answer can be returned in any `unit` available from `t:System.time_unit/0`.
 
-  Fractional results are not supported and are truncated.
+  This function returns the difference in seconds where seconds are measured
+  according to `Calendar.ISO`.
 
   ## Examples
 
@@ -462,57 +420,24 @@ defmodule NaiveDateTime do
       2
       iex> NaiveDateTime.diff(~N[2014-10-02 00:29:12], ~N[2014-10-02 00:29:10], :microsecond)
       2_000_000
-
-      iex> NaiveDateTime.diff(~N[2014-10-02 00:29:10.042], ~N[2014-10-02 00:29:10.021])
-      0
       iex> NaiveDateTime.diff(~N[2014-10-02 00:29:10.042], ~N[2014-10-02 00:29:10.021], :millisecond)
       21
-
       iex> NaiveDateTime.diff(~N[2014-10-02 00:29:10], ~N[2014-10-02 00:29:12])
       -2
       iex> NaiveDateTime.diff(~N[-0001-10-02 00:29:10], ~N[-0001-10-02 00:29:12])
       -2
 
-  It can also compute the difference in days, hours, or minutes:
-
-      iex> NaiveDateTime.diff(~N[2014-10-10 00:29:10], ~N[2014-10-02 00:29:10], :day)
-      8
-      iex> NaiveDateTime.diff(~N[2014-10-02 12:29:10], ~N[2014-10-02 00:29:10], :hour)
-      12
-      iex> NaiveDateTime.diff(~N[2014-10-02 00:39:10], ~N[2014-10-02 00:29:10], :minute)
-      10
-
-  But it also rounds incomplete days to zero:
-
-      iex> NaiveDateTime.diff(~N[2014-10-10 00:29:09], ~N[2014-10-02 00:29:10], :day)
-      7
+      # to Gregorian seconds
+      iex> NaiveDateTime.diff(~N[2014-10-02 00:29:10], ~N[0000-01-01 00:00:00])
+      63579428950
 
   """
   @doc since: "1.4.0"
-  @spec diff(
-          Calendar.naive_datetime(),
-          Calendar.naive_datetime(),
-          :day | :hour | :minute | System.time_unit()
-        ) :: integer
-
-  def diff(naive_datetime1, naive_datetime2, unit \\ :second)
-
-  def diff(naive_datetime1, naive_datetime2, :day) do
-    diff(naive_datetime1, naive_datetime2, :second) |> div(86400)
-  end
-
-  def diff(naive_datetime1, naive_datetime2, :hour) do
-    diff(naive_datetime1, naive_datetime2, :second) |> div(3600)
-  end
-
-  def diff(naive_datetime1, naive_datetime2, :minute) do
-    diff(naive_datetime1, naive_datetime2, :second) |> div(60)
-  end
-
+  @spec diff(Calendar.naive_datetime(), Calendar.naive_datetime(), System.time_unit()) :: integer
   def diff(
         %{calendar: calendar1} = naive_datetime1,
         %{calendar: calendar2} = naive_datetime2,
-        unit
+        unit \\ :second
       ) do
     if not Calendar.compatible_calendars?(calendar1, calendar2) do
       raise ArgumentError,

lib/elixir/lib/calendar/time.ex

@@ -4,7 +4,7 @@ defmodule Time do
 
   The Time struct contains the fields hour, minute, second and microseconds.
   New times can be built with the `new/4` function or using the
-  `~T` (see `sigil_T/2`) sigil:
+  `~T` (see `Kernel.sigil_T/2`) sigil:
 
       iex> ~T[23:00:07.001]
       ~T[23:00:07.001]
@@ -31,12 +31,7 @@ defmodule Time do
 
   Comparisons in Elixir using `==/2`, `>/2`, `</2` and similar are structural
   and based on the `Time` struct fields. For proper comparison between
-  times, use the `compare/2` function. The existence of the `compare/2`
-  function in this module also allows using `Enum.min/2` and `Enum.max/2`
-  functions to get the minimum and maximum time of an `Enum`. For example:
-
-      iex> Enum.min([~T[23:00:07.001], ~T[10:00:07.001]], Time)
-      ~T[10:00:07.001]
+  times, use the `compare/2` function.
   """
 
   @enforce_keys [:hour, :minute, :second]
@@ -454,15 +449,10 @@ defmodule Time do
   end
 
   @doc """
-  Adds the `amount_to_add` of `unit`s to the given `time`.
+  Adds the `number` of `unit`s to the given `time`.
 
-  Accepts an `amount_to_add` in any `unit`. `unit` can be `:day`,
-  `:hour`, `:minute`, `:second` or any subsecond precision from
-  `t:System.time_unit/0`. It defaults to `:second`. Negative values
-  will move backwards in time.
-
-  This function always consider the unit to be computed according
-  to the `Calendar.ISO`.
+  This function accepts the `number` measured according to `Calendar.ISO`.
+  The time is returned in the same calendar as it was given in.
 
   Note the result value represents the time of day, meaning that it is cyclic,
   for instance, it will never go over 24 hours for the ISO calendar.
@@ -470,56 +460,30 @@ defmodule Time do
   ## Examples
 
       iex> Time.add(~T[10:00:00], 27000)
-      ~T[17:30:00]
+      ~T[17:30:00.000000]
       iex> Time.add(~T[11:00:00.005], 2400)
-      ~T[11:40:00.005]
-      iex> Time.add(~T[00:00:00.000], 86_399_999, :millisecond)
-      ~T[23:59:59.999]
-
-  Negative values are allowed:
-
-      iex> Time.add(~T[23:00:00], -60)
-      ~T[22:59:00]
-
-  Note that the time is cyclic:
-
+      ~T[11:40:00.005000]
+      iex> Time.add(~T[00:00:00], 86_399_999, :millisecond)
+      ~T[23:59:59.999000]
       iex> Time.add(~T[17:10:05], 86400)
-      ~T[17:10:05]
-
-  Hours and minutes are also supported:
-
-      iex> Time.add(~T[17:10:05], 2, :hour)
-      ~T[19:10:05]
-      iex> Time.add(~T[17:10:05], 30, :minute)
-      ~T[17:40:05]
+      ~T[17:10:05.000000]
+      iex> Time.add(~T[23:00:00], -60)
+      ~T[22:59:00.000000]
 
   """
   @doc since: "1.6.0"
-  @spec add(Calendar.time(), integer, :hour | :minute | System.time_unit()) :: t
-  def add(time, amount_to_add, unit \\ :second)
-
-  def add(time, amount_to_add, :hour) when is_integer(amount_to_add) do
-    add(time, amount_to_add * 3600, :second)
-  end
-
-  def add(time, amount_to_add, :minute) when is_integer(amount_to_add) do
-    add(time, amount_to_add * 60, :second)
-  end
-
-  def add(%{calendar: calendar, microsecond: {_, precision}} = time, amount_to_add, unit)
-      when is_integer(amount_to_add) do
-    amount_to_add = System.convert_time_unit(amount_to_add, unit, :microsecond)
-    total = time_to_microseconds(time) + amount_to_add
+  @spec add(Calendar.time(), integer, System.time_unit()) :: t
+  def add(%{calendar: calendar} = time, number, unit \\ :second) when is_integer(number) do
+    number = System.convert_time_unit(number, unit, :microsecond)
+    total = time_to_microseconds(time) + number
     parts = Integer.mod(total, @parts_per_day)
-
-    {hour, minute, second, {microsecond, _}} =
-      calendar.time_from_day_fraction({parts, @parts_per_day})
+    {hour, minute, second, microsecond} = calendar.time_from_day_fraction({parts, @parts_per_day})
 
     %Time{
       hour: hour,
       minute: minute,
       second: second,
-      microsecond: {microsecond, precision},
+      microsecond: microsecond,
       calendar: calendar
     }
   end
@@ -686,12 +650,12 @@ defmodule Time do
   additional information about a date or time zone is ignored when calculating
   the difference.
 
-  The answer can be returned in any `:hour`, `:minute`, `:second` or any
-  subsecond `unit` available from `t:System.time_unit/0`. If the first time
-  value is earlier than the second, a negative number is returned.
+  The answer can be returned in any `unit` available from
+  `t:System.time_unit/0`. If the first time value is earlier than
+  the second, a negative number is returned.
 
-  The unit is measured according to `Calendar.ISO` and defaults to `:second`.
-  Fractional results are not supported and are truncated.
+  This function returns the difference in seconds where seconds
+  are measured according to `Calendar.ISO`.
 
   ## Examples
 
@@ -712,24 +676,11 @@ defmodule Time do
       iex> Time.diff(~T[00:29:10], ~T[00:29:12], :microsecond)
       -2_000_000
 
-      iex> Time.diff(~T[02:29:10], ~T[00:29:10], :hour)
-      2
-      iex> Time.diff(~T[02:29:10], ~T[00:29:11], :hour)
-      1
-
   """
   @doc since: "1.5.0"
-  @spec diff(Calendar.time(), Calendar.time(), :hour | :minute | System.time_unit()) :: integer
+  @spec diff(Calendar.time(), Calendar.time(), System.time_unit()) :: integer
   def diff(time1, time2, unit \\ :second)
 
-  def diff(time1, time2, :hour) do
-    diff(time1, time2, :second) |> div(3600)
-  end
-
-  def diff(time1, time2, :minute) do
-    diff(time1, time2, :second) |> div(60)
-  end
-
   def diff(
         %{
           calendar: Calendar.ISO,

lib/elixir/lib/code/formatter.ex

@@ -22,7 +22,7 @@ defmodule Code.Formatter do
   @no_newline_binary_operators [:\\, :in]
 
   # Left associative operators that start on the next line in case of breaks (always pipes)
-  @pipeline_operators [:|>, :~>>, :<<~, :~>, :<~, :<~>, :"<|>"]
+  @pipeline_operators [:|>, :~>>, :<<~, :~>, :<~, :<~>, :<|>]
 
   # Right associative operators that start on the next line in case of breaks
   @right_new_line_before_binary_operators [:|, :when]
@@ -43,8 +43,8 @@ defmodule Code.Formatter do
     :<<~,
     :~>>,
     :<~>,
-    :"<|>",
-    :"^^^",
+    :<|>,
+    :^^^,
     :+++,
     :---,
     :in,
@@ -141,113 +141,172 @@ defmodule Code.Formatter do
 
   @do_end_keywords [:rescue, :catch, :else, :after]
 
-  @bitstring_modifiers [
-    :integer,
-    :float,
-    :bits,
-    :bitstring,
-    :binary,
-    :bytes,
-    :utf8,
-    :utf16,
-    :utf32,
-    :signed,
-    :unsigned,
-    :little,
-    :big,
-    :native,
-    :_
-  ]
-
   @doc """
-  Converts the quoted expression into an algebra document.
+  Checks if two strings are equivalent.
   """
-  def to_algebra(quoted, opts \\ []) do
-    comments = Keyword.get(opts, :comments, [])
+  def equivalent(string1, string2) when is_binary(string1) and is_binary(string2) do
+    quoted1 = :elixir.string_to_quoted!(to_charlist(string1), 1, 1, "nofile", [])
+    quoted2 = :elixir.string_to_quoted!(to_charlist(string2), 1, 1, "nofile", [])
 
-    state =
-      comments
-      |> Enum.map(&format_comment/1)
-      |> gather_comments()
-      |> state(opts)
+    case not_equivalent(quoted1, quoted2) do
+      {left, right} -> {:error, left, right}
+      nil -> :ok
+    end
+  end
 
-    {doc, _} = block_to_algebra(quoted, @min_line, @max_line, state)
-    doc
+  defp not_equivalent({:__block__, _, [left]}, right) do
+    not_equivalent(left, right)
+  end
+
+  defp not_equivalent(left, {:__block__, _, [right]}) do
+    not_equivalent(left, right)
+  end
+
+  defp not_equivalent({:__block__, _, []}, nil) do
+    nil
+  end
+
+  defp not_equivalent(nil, {:__block__, _, []}) do
+    nil
+  end
+
+  defp not_equivalent([left | lefties], [right | righties]) do
+    not_equivalent(left, right) || not_equivalent(lefties, righties)
+  end
+
+  defp not_equivalent({left_name, _, left_args}, {right_name, _, right_args}) do
+    not_equivalent(left_name, right_name) || not_equivalent(left_args, right_args)
+  end
+
+  defp not_equivalent({left1, left2}, {right1, right2}) do
+    not_equivalent(left1, right1) || not_equivalent(left2, right2)
+  end
+
+  defp not_equivalent(side, side) do
+    nil
+  end
+
+  defp not_equivalent(left, right) do
+    {left, right}
   end
 
   @doc """
-  Lists all default locals without parens.
+  Converts `string` to an algebra document.
+
+  Returns `{:ok, doc}` or `{:error, parser_error}`.
+
+  See `Code.format_string!/2` for the list of options.
   """
-  def locals_without_parens do
-    @locals_without_parens
+  def to_algebra(string, opts \\ []) when is_binary(string) and is_list(opts) do
+    file = Keyword.get(opts, :file, "nofile")
+    line = Keyword.get(opts, :line, 1)
+    charlist = String.to_charlist(string)
+
+    Process.put(:code_formatter_comments, [])
+
+    tokenizer_options = [
+      unescape: false,
+      preserve_comments: &preserve_comments/5,
+      warn_on_unnecessary_quotes: false
+    ]
+
+    parser_options = [
+      literal_encoder: &{:ok, {:__block__, &2, [&1]}},
+      token_metadata: true
+    ]
+
+    with {:ok, tokens} <- :elixir.string_to_tokens(charlist, line, 1, file, tokenizer_options),
+         {:ok, forms} <- :elixir.tokens_to_quoted(tokens, file, parser_options) do
+      state =
+        Process.get(:code_formatter_comments)
+        |> Enum.reverse()
+        |> gather_comments()
+        |> state(opts)
+
+      {doc, _} = block_to_algebra(forms, @min_line, @max_line, state)
+      {:ok, doc}
+    end
+  after
+    Process.delete(:code_formatter_comments)
   end
 
   @doc """
-  Checks if a function is a local without parens.
+  Converts `string` to an algebra document.
+
+  Raises if the `string` cannot be parsed.
+
+  See `Code.format_string!/2` for the list of options.
   """
-  def local_without_parens?(fun, arity, locals_without_parens) do
-    arity > 0 and
-      Enum.any?(locals_without_parens, fn {key, val} ->
-        key == fun and (val == :* or val == arity)
-      end)
+  def to_algebra!(string, opts \\ []) do
+    case to_algebra(string, opts) do
+      {:ok, doc} ->
+        doc
+
+      {:error, {location, error, token}} ->
+        :elixir_errors.parse_error(location, Keyword.get(opts, :file, "nofile"), error, token)
+    end
   end
 
   defp state(comments, opts) do
     force_do_end_blocks = Keyword.get(opts, :force_do_end_blocks, false)
-    locals_without_parens = Keyword.get(opts, :locals_without_parens, [])
-    file = Keyword.get(opts, :file, nil)
-    sigils = Keyword.get(opts, :sigils, [])
-    normalize_bitstring_modifiers = Keyword.get(opts, :normalize_bitstring_modifiers, true)
 
-    sigils =
-      Map.new(sigils, fn {key, value} ->
-        with true <- is_atom(key) and is_function(value, 2),
-             [char] <- Atom.to_charlist(key),
-             true <- char in ?A..?Z do
-          {char, value}
-        else
-          _ ->
-            raise ArgumentError,
-                  ":sigils must be a keyword list with a single uppercased letter as key and an " <>
-                    "anonymous function expecting two arguments as value, got: #{inspect(sigils)}"
-        end
-      end)
+    locals_without_parens =
+      Keyword.get(opts, :locals_without_parens, []) ++ @locals_without_parens
 
     %{
       force_do_end_blocks: force_do_end_blocks,
-      locals_without_parens: locals_without_parens ++ locals_without_parens(),
+      locals_without_parens: locals_without_parens,
       operand_nesting: 2,
       skip_eol: false,
-      comments: comments,
-      sigils: sigils,
-      file: file,
-      normalize_bitstring_modifiers: normalize_bitstring_modifiers
+      comments: comments
     }
   end
 
-  defp format_comment(%{text: text} = comment) do
-    %{comment | text: format_comment_text(text)}
+  # Code comment handling
+
+  defp preserve_comments(line, _column, tokens, comment, rest) do
+    comments = Process.get(:code_formatter_comments)
+    comment = {line, {previous_eol(tokens), next_eol(rest, 0)}, format_comment(comment, [])}
+    Process.put(:code_formatter_comments, [comment | comments])
   end
 
-  defp format_comment_text("#"), do: "#"
-  defp format_comment_text("#!" <> rest), do: "#!" <> rest
-  defp format_comment_text("##" <> rest), do: "#" <> format_comment_text("#" <> rest)
-  defp format_comment_text("# " <> rest), do: "# " <> rest
-  defp format_comment_text("#" <> rest), do: "# " <> rest
+  defp next_eol('\s' ++ rest, count), do: next_eol(rest, count)
+  defp next_eol('\t' ++ rest, count), do: next_eol(rest, count)
+  defp next_eol('\n' ++ rest, count), do: next_eol(rest, count + 1)
+  defp next_eol('\r\n' ++ rest, count), do: next_eol(rest, count + 1)
+  defp next_eol(_, count), do: count
+
+  defp previous_eol([{token, {_, _, count}} | _])
+       when token in [:eol, :",", :";"] and count > 0 do
+    count
+  end
+
+  defp previous_eol([]), do: 1
+  defp previous_eol(_), do: nil
+
+  defp format_comment('##' ++ rest, acc), do: format_comment([?# | rest], [?# | acc])
+
+  defp format_comment('#!', acc), do: reverse_to_string(acc, '#!')
+  defp format_comment('#! ' ++ _ = rest, acc), do: reverse_to_string(acc, rest)
+  defp format_comment('#!' ++ rest, acc), do: reverse_to_string(acc, [?#, ?!, ?\s, rest])
+
+  defp format_comment('#', acc), do: reverse_to_string(acc, '#')
+  defp format_comment('# ' ++ _ = rest, acc), do: reverse_to_string(acc, rest)
+  defp format_comment('#' ++ rest, acc), do: reverse_to_string(acc, [?#, ?\s, rest])
+
+  defp reverse_to_string(acc, prefix) do
+    acc |> Enum.reverse(prefix) |> List.to_string()
+  end
 
   # If there is a no new line before, we can't gather all followup comments.
-  defp gather_comments([%{previous_eol_count: 0} = comment | comments]) do
-    comment = %{comment | previous_eol_count: @newlines}
+  defp gather_comments([{line, {nil, next_eol}, doc} | comments]) do
+    comment = {line, {@newlines, next_eol}, doc}
     [comment | gather_comments(comments)]
   end
 
-  defp gather_comments([comment | comments]) do
-    %{line: line, next_eol_count: next_eol_count, text: doc} = comment
-
-    {next_eol_count, comments, doc} =
-      gather_followup_comments(line + 1, next_eol_count, comments, doc)
-
-    comment = %{comment | next_eol_count: next_eol_count, text: doc}
+  defp gather_comments([{line, {previous_eol, next_eol}, doc} | comments]) do
+    {next_eol, comments, doc} = gather_followup_comments(line + 1, next_eol, comments, doc)
+    comment = {line, {previous_eol, next_eol}, doc}
     [comment | gather_comments(comments)]
   end
 
@@ -255,14 +314,13 @@ defmodule Code.Formatter do
     []
   end
 
-  defp gather_followup_comments(line, _, [%{line: line} = comment | comments], doc)
-       when comment.previous_eol_count != 0 do
-    %{next_eol_count: next_eol_count, text: text} = comment
-    gather_followup_comments(line + 1, next_eol_count, comments, line(doc, text))
+  defp gather_followup_comments(line, _, [{line, {previous_eol, next_eol}, text} | comments], doc)
+       when previous_eol != nil do
+    gather_followup_comments(line + 1, next_eol, comments, line(doc, text))
   end
 
-  defp gather_followup_comments(_line, next_eol_count, comments, doc) do
-    {next_eol_count, comments, doc}
+  defp gather_followup_comments(_line, next_eol, comments, doc) do
+    {next_eol, comments, doc}
   end
 
   # Special AST nodes from compiler feedback
@@ -292,7 +350,7 @@ defmodule Code.Formatter do
         {doc, state} =
           entries
           |> prepend_heredoc_line()
-          |> interpolation_to_algebra(~s["""], state, @double_heredoc, @double_heredoc)
+          |> interpolation_to_algebra(:heredoc, state, @double_heredoc, @double_heredoc)
 
         {force_unfit(doc), state}
 
@@ -314,7 +372,7 @@ defmodule Code.Formatter do
         {doc, state} =
           entries
           |> prepend_heredoc_line()
-          |> list_interpolation_to_algebra(~s['''], state, @single_heredoc, @single_heredoc)
+          |> list_interpolation_to_algebra(:heredoc, state, @single_heredoc, @single_heredoc)
 
         {force_unfit(doc), state}
 
@@ -377,7 +435,7 @@ defmodule Code.Formatter do
   defp quoted_to_algebra({:__block__, meta, [list]}, _context, state) when is_list(list) do
     case meta[:delimiter] do
       ~s['''] ->
-        string = list |> List.to_string() |> escape_heredoc(~s['''])
+        string = list |> List.to_string() |> escape_heredoc()
         {@single_heredoc |> concat(string) |> concat(@single_heredoc) |> force_unfit(), state}
 
       ~s['] ->
@@ -391,7 +449,7 @@ defmodule Code.Formatter do
 
   defp quoted_to_algebra({:__block__, meta, [string]}, _context, state) when is_binary(string) do
     if meta[:delimiter] == ~s["""] do
-      string = escape_heredoc(string, ~s["""])
+      string = escape_heredoc(string)
       {@double_heredoc |> concat(string) |> concat(@double_heredoc) |> force_unfit(), state}
     else
       string = escape_string(string, @double_quote)
@@ -399,8 +457,8 @@ defmodule Code.Formatter do
     end
   end
 
-  defp quoted_to_algebra({:__block__, meta, [atom]}, _context, state) when is_atom(atom) do
-    {atom_to_algebra(atom, meta), state}
+  defp quoted_to_algebra({:__block__, _, [atom]}, _context, state) when is_atom(atom) do
+    {atom_to_algebra(atom), state}
   end
 
   defp quoted_to_algebra({:__block__, meta, [integer]}, _context, state)
@@ -465,15 +523,6 @@ defmodule Code.Formatter do
     binary_op_to_algebra(:in, "not in", meta, left, right, context, state)
   end
 
-  # ..
-  defp quoted_to_algebra({:.., _meta, []}, context, state) do
-    if context in [:no_parens_arg, :no_parens_one_arg] do
-      {"(..)", state}
-    else
-      {"..", state}
-    end
-  end
-
   # 1..2//3
   defp quoted_to_algebra({:"..//", meta, [left, middle, right]}, context, state) do
     quoted_to_algebra({:"//", meta, [{:.., meta, [left, middle]}, right]}, context, state)
@@ -518,10 +567,12 @@ defmodule Code.Formatter do
 
             {:__block__, _, [atom]} when is_atom(atom) ->
               key =
-                if Macro.classify_atom(atom) in [:identifier, :unquoted] do
-                  IO.iodata_to_binary([Atom.to_string(atom), ?:])
-                else
-                  IO.iodata_to_binary([?", Atom.to_string(atom), ?", ?:])
+                case Code.Identifier.classify(atom) do
+                  type when type in [:callable_local, :callable_operator, :not_callable] ->
+                    IO.iodata_to_binary([Atom.to_string(atom), ?:])
+
+                  _ ->
+                    IO.iodata_to_binary([?", Atom.to_string(atom), ?", ?:])
                 end
 
               {string(key), state}
@@ -547,11 +598,6 @@ defmodule Code.Formatter do
     {doc, state}
   end
 
-  # #PID's and #Ref's may appear on regular AST
-  defp quoted_to_algebra(unknown, _context, state) do
-    {inspect(unknown), state}
-  end
-
   ## Blocks
 
   defp block_to_algebra([{:->, _, _} | _] = type_fun, min_line, max_line, state) do
@@ -894,7 +940,7 @@ defmodule Code.Formatter do
   # @foo(bar)
   defp module_attribute_to_algebra(meta, {name, call_meta, [_] = args} = expr, context, state)
        when is_atom(name) and name not in [:__block__, :__aliases__] do
-    if Macro.classify_atom(name) == :identifier do
+    if Code.Identifier.classify(name) == :callable_local do
       {{call_doc, state}, wrap_in_parens?} =
         call_args_to_algebra(args, call_meta, context, :skip_unless_many_args, false, state)
 
@@ -939,7 +985,7 @@ defmodule Code.Formatter do
        )
        when is_atom(fun) and is_integer(arity) do
     {target_doc, state} = remote_target_to_algebra(target, state)
-    fun = Macro.inspect_atom(:remote_call, fun)
+    fun = Code.Identifier.inspect_as_function(fun)
     {target_doc |> nest(1) |> concat(string(".#{fun}/#{arity}")), state}
   end
 
@@ -984,7 +1030,7 @@ defmodule Code.Formatter do
   defp remote_to_algebra({{:., _, [target, fun]}, meta, args}, context, state)
        when is_atom(fun) do
     {target_doc, state} = remote_target_to_algebra(target, state)
-    fun = Macro.inspect_atom(:remote_call, fun)
+    fun = Code.Identifier.inspect_as_function(fun)
     remote_doc = target_doc |> concat(".") |> concat(string(fun))
 
     if args == [] and not remote_target_is_a_module?(target) and not meta?(meta, :closing) do
@@ -1034,14 +1080,9 @@ defmodule Code.Formatter do
   defp local_to_algebra(fun, meta, args, context, state) when is_atom(fun) do
     skip_parens =
       cond do
-        meta?(meta, :closing) ->
-          :skip_if_only_do_end
-
-        local_without_parens?(fun, length(args), state.locals_without_parens) ->
-          :skip_unless_many_args
-
-        true ->
-          :skip_if_do_end
+        meta?(meta, :closing) -> :skip_if_only_do_end
+        local_without_parens?(fun, args, state) -> :skip_unless_many_args
+        true -> :skip_if_do_end
       end
 
     {{call_doc, state}, wrap_in_parens?} =
@@ -1220,6 +1261,15 @@ defmodule Code.Formatter do
     end
   end
 
+  defp local_without_parens?(fun, args, %{locals_without_parens: locals_without_parens}) do
+    length = length(args)
+
+    length > 0 and
+      Enum.any?(locals_without_parens, fn {key, val} ->
+        key == fun and (val == :* or val == length)
+      end)
+  end
+
   defp no_generators?(args) do
     not Enum.any?(args, &match?({:<-, _, [_, _]}, &1))
   end
@@ -1297,7 +1347,7 @@ defmodule Code.Formatter do
 
   defp list_interpolation_to_algebra([entry | entries], escape, state, acc, last) do
     {{:., _, [Kernel, :to_string]}, _meta, [quoted]} = entry
-    {doc, state} = interpolation_to_algebra(quoted, state)
+    {doc, state} = interpolation_to_string(quoted, state)
     list_interpolation_to_algebra(entries, escape, state, concat(acc, doc), last)
   end
 
@@ -1313,7 +1363,7 @@ defmodule Code.Formatter do
 
   defp interpolation_to_algebra([entry | entries], escape, state, acc, last) do
     {:"::", _, [{{:., _, [Kernel, :to_string]}, _meta, [quoted]}, {:binary, _, _}]} = entry
-    {doc, state} = interpolation_to_algebra(quoted, state)
+    {doc, state} = interpolation_to_string(quoted, state)
     interpolation_to_algebra(entries, escape, state, concat(acc, doc), last)
   end
 
@@ -1321,9 +1371,21 @@ defmodule Code.Formatter do
     {concat(acc, last), state}
   end
 
-  defp interpolation_to_algebra(quoted, %{skip_eol: skip_eol} = state) do
+  defp interpolation_to_string(quoted, %{skip_eol: skip_eol} = state) do
     {doc, state} = block_to_algebra(quoted, @max_line, @min_line, %{state | skip_eol: true})
-    {no_limit(surround("\#{", doc, "}")), %{state | skip_eol: skip_eol}}
+    doc = interpolation_to_string(surround("\#{", doc, "}"))
+    {doc, %{state | skip_eol: skip_eol}}
+  end
+
+  defp interpolation_to_string(doc) do
+    [head | tail] =
+      doc
+      |> format_to_string()
+      |> String.split("\n")
+
+    Enum.reduce(tail, string(head), fn line, acc ->
+      concat([acc, line(), string(line)])
+    end)
   end
 
   ## Sigils
@@ -1334,37 +1396,13 @@ defmodule Code.Formatter do
          opening_delimiter when not is_nil(opening_delimiter) <- meta[:delimiter] do
       doc = <<?~, name, opening_delimiter::binary>>
 
-      entries =
-        case state.sigils do
-          %{^name => callback} ->
-            metadata = [
-              file: state.file,
-              line: meta[:line],
-              sigil: List.to_atom([name]),
-              modifiers: modifiers,
-              opening_delimiter: opening_delimiter
-            ]
-
-            case callback.(hd(entries), metadata) do
-              iodata when is_binary(iodata) or is_list(iodata) ->
-                [IO.iodata_to_binary(iodata)]
-
-              other ->
-                raise ArgumentError,
-                      "expected sigil callback to return iodata, got: #{inspect(other)}"
-            end
-
-          %{} ->
-            entries
-        end
-
       if opening_delimiter in [@double_heredoc, @single_heredoc] do
         closing_delimiter = concat(opening_delimiter, List.to_string(modifiers))
 
         {doc, state} =
           entries
           |> prepend_heredoc_line()
-          |> interpolation_to_algebra(opening_delimiter, state, doc, closing_delimiter)
+          |> interpolation_to_algebra(:heredoc, state, doc, closing_delimiter)
 
         {force_unfit(doc), state}
       else
@@ -1411,7 +1449,7 @@ defmodule Code.Formatter do
 
   defp bitstring_segment_to_algebra({{:"::", _, [segment, spec]}, i}, state, last) do
     {doc, state} = quoted_to_algebra(segment, :parens_arg, state)
-    {spec, state} = bitstring_spec_to_algebra(spec, state, state.normalize_bitstring_modifiers)
+    {spec, state} = bitstring_spec_to_algebra(spec, state)
 
     spec = wrap_in_parens_if_inspected_atom(spec)
     spec = if i == last, do: bitstring_wrap_parens(spec, i, last), else: spec
@@ -1430,35 +1468,16 @@ defmodule Code.Formatter do
     {bitstring_wrap_parens(doc, i, last), state}
   end
 
-  defp bitstring_spec_to_algebra({op, _, [left, right]}, state, normalize_modifiers)
-       when op in [:-, :*] do
-    normalize_modifiers = normalize_modifiers && op != :*
-    {left, state} = bitstring_spec_to_algebra(left, state, normalize_modifiers)
-    {right, state} = bitstring_spec_element_to_algebra(right, state, normalize_modifiers)
+  defp bitstring_spec_to_algebra({op, _, [left, right]}, state) when op in [:-, :*] do
+    {left, state} = bitstring_spec_to_algebra(left, state)
+    {right, state} = quoted_to_algebra_with_parens_if_operator(right, :parens_arg, state)
     {concat(concat(left, Atom.to_string(op)), right), state}
   end
 
-  defp bitstring_spec_to_algebra(spec, state, normalize_modifiers) do
-    bitstring_spec_element_to_algebra(spec, state, normalize_modifiers)
+  defp bitstring_spec_to_algebra(spec, state) do
+    quoted_to_algebra_with_parens_if_operator(spec, :parens_arg, state)
   end
 
-  defp bitstring_spec_element_to_algebra(
-         {atom, meta, empty_args},
-         state,
-         _normalize_modifiers = true
-       )
-       when is_atom(atom) and empty_args in [nil, []] do
-    empty_args = bitstring_spec_normalize_empty_args(atom)
-    quoted_to_algebra_with_parens_if_operator({atom, meta, empty_args}, :parens_arg, state)
-  end
-
-  defp bitstring_spec_element_to_algebra(spec_element, state, _normalize_modifiers) do
-    quoted_to_algebra_with_parens_if_operator(spec_element, :parens_arg, state)
-  end
-
-  defp bitstring_spec_normalize_empty_args(atom) when atom in @bitstring_modifiers, do: nil
-  defp bitstring_spec_normalize_empty_args(_atom), do: []
-
   defp bitstring_wrap_parens(doc, i, last) when i == 0 or i == last do
     string = format_to_string(doc)
 
@@ -1526,36 +1545,25 @@ defmodule Code.Formatter do
     end
   end
 
-  defp atom_to_algebra(atom, _) when atom in [nil, true, false] do
+  defp atom_to_algebra(atom) when atom in [nil, true, false] do
     Atom.to_string(atom)
   end
 
   # TODO: Remove this clause in v1.16 when we no longer quote operator :..//
-  defp atom_to_algebra(:"..//", _) do
+  defp atom_to_algebra(:"..//") do
     string(":\"..//\"")
   end
 
-  defp atom_to_algebra(:\\, meta) do
-    # Since we parse strings without unescaping, the atoms
-    # :\\ and :"\\" have the same representation, so we need
-    # to check the delimiter and handle them accordingly.
-    string =
-      case Keyword.get(meta, :delimiter) do
-        "\"" -> ":\"\\\\\""
-        _ -> ":\\\\"
-      end
-
-    string(string)
-  end
-
-  defp atom_to_algebra(atom, _) do
+  defp atom_to_algebra(atom) do
     string = Atom.to_string(atom)
 
     iodata =
-      if Macro.classify_atom(atom) in [:unquoted, :identifier] do
-        [?:, string]
-      else
-        [?:, ?", String.replace(string, "\"", "\\\""), ?"]
+      case Code.Identifier.classify(atom) do
+        type when type in [:callable_local, :callable_operator, :not_callable] ->
+          [?:, string]
+
+        _ ->
+          [?:, ?", String.replace(string, "\"", "\\\""), ?"]
       end
 
     iodata |> IO.iodata_to_binary() |> string()
@@ -1603,13 +1611,11 @@ defmodule Code.Formatter do
     end
   end
 
-  defp escape_heredoc(string, escape) do
-    string = String.replace(string, escape, "\\" <> escape)
+  defp escape_heredoc(string) do
     heredoc_to_algebra(["" | String.split(string, "\n")])
   end
 
-  defp escape_string(string, <<_, _, _>> = escape) do
-    string = String.replace(string, escape, "\\" <> escape)
+  defp escape_string(string, :heredoc) do
     heredoc_to_algebra(String.split(string, "\n"))
   end
 
@@ -1702,15 +1708,12 @@ defmodule Code.Formatter do
        ) do
     min_line = line(meta)
     {body_doc, state} = block_to_algebra(body, min_line, max_line, state)
-    break_or_line = clause_break_or_line(clauses, state)
 
     doc =
       "fn ->"
-      |> concat(break_or_line)
-      |> concat(body_doc)
+      |> glue(body_doc)
       |> nest(2)
-      |> concat(break_or_line)
-      |> concat("end")
+      |> glue("end")
       |> maybe_force_clauses(clauses, state)
       |> group()
 
@@ -1739,16 +1742,12 @@ defmodule Code.Formatter do
       |> nest(:cursor)
       |> group()
 
-    break_or_line = clause_break_or_line(clauses, state)
-
     doc =
       "fn "
       |> concat(head)
-      |> concat(break_or_line)
-      |> concat(body_doc)
+      |> glue(body_doc)
       |> nest(2)
-      |> concat(break_or_line)
-      |> concat("end")
+      |> glue("end")
       |> maybe_force_clauses(clauses, state)
       |> group()
 
@@ -1790,14 +1789,13 @@ defmodule Code.Formatter do
     min_line = line(meta)
     {args_doc, state} = clause_args_to_algebra(args, min_line, state)
     {body_doc, state} = block_to_algebra(body, min_line, max_line, state)
-    break_or_line = clause_break_or_line(clauses, state)
 
     doc =
       args_doc
       |> ungroup_if_group()
       |> concat(" ->")
       |> group()
-      |> concat(break_or_line |> concat(body_doc) |> nest(2))
+      |> concat(break() |> concat(body_doc) |> nest(2))
       |> wrap_in_parens()
       |> maybe_force_clauses(clauses, state)
       |> group()
@@ -1818,21 +1816,12 @@ defmodule Code.Formatter do
 
   ## Clauses
 
-  defp multi_line_clauses?(clauses, state) do
-    Enum.any?(clauses, fn {:->, meta, [_, block]} ->
-      eol?(meta, state) or multi_line_block?(block)
-    end)
-  end
-
-  defp multi_line_block?({:__block__, _, [_, _ | _]}), do: true
-  defp multi_line_block?(_), do: false
-
-  defp clause_break_or_line(clauses, state) do
-    if multi_line_clauses?(clauses, state), do: line(), else: break()
-  end
-
   defp maybe_force_clauses(doc, clauses, state) do
-    if multi_line_clauses?(clauses, state), do: force_unfit(doc), else: doc
+    if Enum.any?(clauses, fn {:->, meta, _} -> eol?(meta, state) end) do
+      force_unfit(doc)
+    else
+      doc
+    end
   end
 
   defp clauses_to_algebra([{:->, _, _} | _] = clauses, min_line, max_line, state) do
@@ -1931,7 +1920,7 @@ defmodule Code.Formatter do
   defp quoted_to_algebra_with_comments(args, acc, min_line, max_line, state, fun) do
     {pre_comments, state} =
       get_and_update_in(state.comments, fn comments ->
-        Enum.split_while(comments, fn %{line: line} -> line <= min_line end)
+        Enum.split_while(comments, fn {line, _, _} -> line <= min_line end)
       end)
 
     {docs, comments?, state} =
@@ -1947,29 +1936,23 @@ defmodule Code.Formatter do
   end
 
   defp each_quoted_to_algebra_with_comments([arg | args], acc, max_line, state, comments?, fun) do
-    case traverse_line(arg, {@max_line, @min_line}) do
-      {@max_line, @min_line} ->
-        {doc_triplet, state} = fun.(arg, args, state)
-        acc = [doc_triplet | acc]
-        each_quoted_to_algebra_with_comments(args, acc, max_line, state, comments?, fun)
+    {doc_start, doc_end} = traverse_line(arg, {@max_line, @min_line})
 
-      {doc_start, doc_end} ->
-        {acc, comments, comments?} =
-          extract_comments_before(doc_start, acc, state.comments, comments?)
+    {acc, comments, comments?} =
+      extract_comments_before(doc_start, acc, state.comments, comments?)
 
-        {doc_triplet, state} = fun.(arg, args, %{state | comments: comments})
+    {doc_triplet, state} = fun.(arg, args, %{state | comments: comments})
 
-        {acc, comments, comments?} =
-          extract_comments_trailing(doc_start, doc_end, acc, state.comments, comments?)
+    {acc, comments, comments?} =
+      extract_comments_trailing(doc_start, doc_end, acc, state.comments, comments?)
 
-        acc = [adjust_trailing_newlines(doc_triplet, doc_end, comments) | acc]
-        state = %{state | comments: comments}
-        each_quoted_to_algebra_with_comments(args, acc, max_line, state, comments?, fun)
-    end
+    acc = [adjust_trailing_newlines(doc_triplet, doc_end, comments) | acc]
+    state = %{state | comments: comments}
+    each_quoted_to_algebra_with_comments(args, acc, max_line, state, comments?, fun)
   end
 
-  defp extract_comments_before(max, acc, [%{line: line} = comment | rest], _) when line < max do
-    %{previous_eol_count: previous, next_eol_count: next, text: doc} = comment
+  defp extract_comments_before(max, acc, [{line, _, _} = comment | rest], _) when line < max do
+    {_, {previous, next}, doc} = comment
     acc = [{doc, @empty, next} | add_previous_to_acc(acc, previous)]
     extract_comments_before(max, acc, rest, true)
   end
@@ -1984,7 +1967,7 @@ defmodule Code.Formatter do
   defp add_previous_to_acc(acc, _previous),
     do: acc
 
-  defp extract_comments_trailing(min, max, acc, [%{line: line, text: doc_comment} | rest], _)
+  defp extract_comments_trailing(min, max, acc, [{line, _, doc_comment} | rest], _)
        when line >= min and line <= max do
     acc = [{doc_comment, @empty, 1} | acc]
     extract_comments_trailing(min, max, acc, rest, true)
@@ -1996,7 +1979,7 @@ defmodule Code.Formatter do
 
   # If the document is immediately followed by comment which is followed by newlines,
   # its newlines wouldn't have considered the comment, so we need to adjust it.
-  defp adjust_trailing_newlines({doc, next_line, newlines}, doc_end, [%{line: line} | _])
+  defp adjust_trailing_newlines({doc, next_line, newlines}, doc_end, [{line, _, _} | _])
        when newlines > 1 and line == doc_end + 1 do
     {doc, next_line, 1}
   end
@@ -2114,7 +2097,7 @@ defmodule Code.Formatter do
 
   defp module_attribute_read?({:@, _, [{var, _, var_context}]})
        when is_atom(var) and is_atom(var_context) do
-    Macro.classify_atom(var) == :identifier
+    Code.Identifier.classify(var) == :callable_local
   end
 
   defp module_attribute_read?(_), do: false
@@ -2203,7 +2186,7 @@ defmodule Code.Formatter do
       (
         min_line = line(meta)
         max_line = closing_line(meta)
-        Enum.any?(comments, fn %{line: line} -> line > min_line and line < max_line end)
+        Enum.any?(comments, fn {line, _, _} -> line > min_line and line < max_line end)
       )
   end
 
@@ -2228,8 +2211,8 @@ defmodule Code.Formatter do
         {{_, arg_meta, _}, _} = hd(arg)
         first_line = line(arg_meta)
 
-        case Enum.drop_while(comments, fn %{line: line} -> line <= block_line end) do
-          [%{line: line} | _] when line <= first_line ->
+        case Enum.drop_while(comments, fn {line, _, _} -> line <= block_line end) do
+          [{line, _, _} | _] when line <= first_line ->
             {false, block}
 
           _ ->
@@ -2247,7 +2230,7 @@ defmodule Code.Formatter do
   end
 
   defp force_args?(args) do
-    match?([_ | _], args) and force_args?(args, %{})
+    match?([_, _ | _], args) and force_args?(args, MapSet.new())
   end
 
   defp force_args?([[arg | _] | args], lines) do
@@ -2257,19 +2240,18 @@ defmodule Code.Formatter do
   defp force_args?([arg | args], lines) do
     line =
       case arg do
-        {{_, meta, _}, _} -> meta[:line]
-        {_, meta, _} -> meta[:line]
+        {{_, meta, _}, _} -> line(meta)
+        {_, meta, _} -> line(meta)
       end
 
-    cond do
-      # Line may be missing from non-formatter AST
-      is_nil(line) -> force_args?(args, lines)
-      Map.has_key?(lines, line) -> false
-      true -> force_args?(args, Map.put(lines, line, true))
+    if MapSet.member?(lines, line) do
+      false
+    else
+      force_args?(args, MapSet.put(lines, line))
     end
   end
 
-  defp force_args?([], lines), do: map_size(lines) >= 2
+  defp force_args?([], _lines), do: true
 
   defp force_keyword(doc, arg) do
     if force_args?(arg), do: force_unfit(doc), else: doc

lib/elixir/lib/code/identifier.ex

@@ -14,7 +14,7 @@ defmodule Code.Identifier do
   def unary_op(op) do
     cond do
       op in [:&] -> {:non_associative, 90}
-      op in [:!, :^, :not, :+, :-, :"~~~"] -> {:non_associative, 300}
+      op in [:!, :^, :not, :+, :-, :~~~] -> {:non_associative, 300}
       op in [:@] -> {:non_associative, 320}
       true -> :error
     end
@@ -41,19 +41,161 @@ defmodule Code.Identifier do
       op in [:&&, :&&&, :and] -> {:left, 130}
       op in [:==, :!=, :=~, :===, :!==] -> {:left, 140}
       op in [:<, :<=, :>=, :>] -> {:left, 150}
-      op in [:|>, :<<<, :>>>, :<~, :~>, :<<~, :~>>, :<~>, :"<|>"] -> {:left, 160}
+      op in [:|>, :<<<, :>>>, :<~, :~>, :<<~, :~>>, :<~>, :<|>] -> {:left, 160}
       op in [:in] -> {:left, 170}
-      op in [:"^^^"] -> {:left, 180}
+      op in [:^^^] -> {:left, 180}
       op in [:"//"] -> {:right, 190}
       op in [:++, :--, :.., :<>, :+++, :---] -> {:right, 200}
       op in [:+, :-] -> {:left, 210}
       op in [:*, :/] -> {:left, 220}
-      op in [:**] -> {:left, 230}
       op in [:.] -> {:left, 310}
       true -> :error
     end
   end
 
+  @doc """
+  Classifies the given atom into one of the following categories:
+
+    * `:alias` - a valid Elixir alias, like `Foo`, `Foo.Bar` and so on
+
+    * `:callable_local` - an atom that can be used as a local call;
+      this category includes identifiers like `:foo`
+
+    * `:callable_operator` - all callable operators, such as `:<>`. Note
+      operators such as `:..` are not callable because of ambiguity
+
+    * `:not_atomable` - callable operators that must be wrapped in quotes when
+      defined as an atom. For example, `::` must be written as `:"::"` to avoid
+      the ambiguity between the atom and the keyword identifier
+
+    * `:not_callable` - an atom that cannot be used as a function call after the
+      `.` operator. Those are typically AST nodes that are special forms (such as
+      `:%{}` and `:<<>>>`) as well as nodes that are ambiguous in calls (such as
+      `:..` and `:...`). This category also includes atoms like `:Foo`, since
+      they are valid identifiers but they need quotes to be used in function
+      calls (`Foo."Bar"`)
+
+    * `:other` - any other atom (these are usually escaped when inspected, like
+      `:"foo and bar"`)
+
+  """
+  def classify(atom) when is_atom(atom) do
+    charlist = Atom.to_charlist(atom)
+
+    cond do
+      atom in [:%, :%{}, :{}, :<<>>, :..., :.., :., :"..//", :->] ->
+        :not_callable
+
+      atom in [:"::", :"//"] ->
+        :not_atomable
+
+      unary_op(atom) != :error or binary_op(atom) != :error ->
+        :callable_operator
+
+      valid_alias?(charlist) ->
+        :alias
+
+      true ->
+        case :elixir_config.get(:identifier_tokenizer, String.Tokenizer).tokenize(charlist) do
+          {kind, _acc, [], _, _, special} ->
+            if kind == :identifier and not :lists.member(?@, special) do
+              :callable_local
+            else
+              :not_callable
+            end
+
+          _ ->
+            :other
+        end
+    end
+  end
+
+  defp valid_alias?('Elixir' ++ rest), do: valid_alias_piece?(rest)
+  defp valid_alias?(_other), do: false
+
+  defp valid_alias_piece?([?., char | rest]) when char >= ?A and char <= ?Z,
+    do: valid_alias_piece?(trim_leading_while_valid_identifier(rest))
+
+  defp valid_alias_piece?([]), do: true
+  defp valid_alias_piece?(_other), do: false
+
+  defp trim_leading_while_valid_identifier([char | rest])
+       when char >= ?a and char <= ?z
+       when char >= ?A and char <= ?Z
+       when char >= ?0 and char <= ?9
+       when char == ?_ do
+    trim_leading_while_valid_identifier(rest)
+  end
+
+  defp trim_leading_while_valid_identifier(other) do
+    other
+  end
+
+  @doc """
+  Inspects the identifier as an atom.
+  """
+  def inspect_as_atom(atom) when is_nil(atom) or is_boolean(atom) do
+    Atom.to_string(atom)
+  end
+
+  def inspect_as_atom(atom) when is_atom(atom) do
+    binary = Atom.to_string(atom)
+
+    case classify(atom) do
+      :alias ->
+        case binary do
+          binary when binary in ["Elixir", "Elixir.Elixir"] -> binary
+          "Elixir.Elixir." <> _rest -> binary
+          "Elixir." <> rest -> rest
+        end
+
+      type when type in [:callable_local, :callable_operator, :not_callable] ->
+        ":" <> binary
+
+      _ ->
+        {escaped, _} = escape(binary, ?")
+        IO.iodata_to_binary([?:, ?", escaped, ?"])
+    end
+  end
+
+  @doc """
+  Inspects the given identifier as a key.
+  """
+  def inspect_as_key(atom) when is_atom(atom) do
+    binary = Atom.to_string(atom)
+
+    case classify(atom) do
+      type when type in [:callable_local, :callable_operator, :not_callable] ->
+        IO.iodata_to_binary([binary, ?:])
+
+      _ ->
+        {escaped, _} = escape(binary, ?")
+        IO.iodata_to_binary([?", escaped, ?", ?:])
+    end
+  end
+
+  @doc """
+  Inspects the given identifier as a function name.
+  """
+  def inspect_as_function(atom) when is_atom(atom) do
+    binary = Atom.to_string(atom)
+
+    case classify(atom) do
+      type when type in [:callable_local, :callable_operator, :not_atomable] ->
+        binary
+
+      type ->
+        escaped =
+          if type in [:not_callable, :alias] do
+            binary
+          else
+            elem(escape(binary, ?"), 0)
+          end
+
+        IO.iodata_to_binary([?", escaped, ?"])
+    end
+  end
+
   @doc """
   Extracts the name and arity of the parent from the anonymous function identifier.
   """
@@ -71,12 +213,8 @@ defmodule Code.Identifier do
   @doc """
   Escapes the given identifier.
   """
-  @spec escape(binary(), char() | nil, :infinity | non_neg_integer, (char() -> iolist() | false)) ::
-          {escaped :: iolist(), remaining :: binary()}
-  def escape(binary, char, limit \\ :infinity, fun \\ &escape_map/1)
-      when ((char in 0..0x10FFFF or is_nil(char)) and limit == :infinity) or
-             (is_integer(limit) and limit >= 0) do
-    escape(binary, char, limit, [], fun)
+  def escape(other, char, count \\ :infinity, fun \\ &escape_map/1) do
+    escape(other, char, count, [], fun)
   end
 
   defp escape(<<_, _::binary>> = binary, _char, 0, acc, _fun) do

lib/elixir/lib/code/normalizer.ex

@@ -1,593 +0,0 @@
-defmodule Code.Normalizer do
-  @moduledoc false
-
-  defguard is_literal(x)
-           when is_integer(x) or
-                  is_float(x) or
-                  is_binary(x) or
-                  is_atom(x)
-
-  @doc """
-  Wraps literals in the quoted expression to conform to the AST format expected
-  by the formatter.
-  """
-  def normalize(quoted, opts \\ []) do
-    line = Keyword.get(opts, :line, nil)
-    escape = Keyword.get(opts, :escape, true)
-    locals_without_parens = Keyword.get(opts, :locals_without_parens, [])
-
-    state = %{
-      escape: escape,
-      parent_meta: [line: line],
-      locals_without_parens: locals_without_parens ++ Code.Formatter.locals_without_parens()
-    }
-
-    do_normalize(quoted, state)
-  end
-
-  # Wrapped literals should receive the block meta
-  defp do_normalize({:__block__, meta, [literal]}, state)
-       when not is_tuple(literal) or tuple_size(literal) == 2 do
-    normalize_literal(literal, meta, state)
-  end
-
-  # Only normalize the first argument of an alias if it's not an atom
-  defp do_normalize({:__aliases__, meta, [first | rest]}, state) when not is_atom(first) do
-    meta = patch_meta_line(meta, state.parent_meta)
-    first = do_normalize(first, %{state | parent_meta: meta})
-    {:__aliases__, meta, [first | rest]}
-  end
-
-  defp do_normalize({:__aliases__, _, _} = quoted, _state) do
-    quoted
-  end
-
-  # Skip captured arguments like &1
-  defp do_normalize({:&, meta, [term]}, state) when is_integer(term) do
-    meta = patch_meta_line(meta, state.parent_meta)
-    {:&, meta, [term]}
-  end
-
-  # Ranges
-  defp do_normalize(left..right//step, state) do
-    left = do_normalize(left, state)
-    right = do_normalize(right, state)
-    meta = meta_line(state)
-
-    if step == 1 do
-      {:.., meta, [left, right]}
-    else
-      step = do_normalize(step, state)
-      {:"..//", meta, [left, right, step]}
-    end
-  end
-
-  # Bit containers
-  defp do_normalize({:<<>>, _, args} = quoted, state) when is_list(args) do
-    normalize_bitstring(quoted, state)
-  end
-
-  # Atoms with interpolations
-  defp do_normalize(
-         {{:., dot_meta, [:erlang, :binary_to_atom]}, call_meta,
-          [{:<<>>, _, args} = string, :utf8]},
-         state
-       )
-       when is_list(args) do
-    dot_meta = patch_meta_line(dot_meta, state.parent_meta)
-    call_meta = patch_meta_line(call_meta, dot_meta)
-
-    utf8 =
-      if args == [] or interpolated?(string) do
-        # a non-normalized :utf8 atom signals an atom interpolation
-        :utf8
-      else
-        normalize_literal(:utf8, [], state)
-      end
-
-    string =
-      if state.escape do
-        normalize_bitstring(string, state, true)
-      else
-        normalize_bitstring(string, state)
-      end
-
-    {{:., dot_meta, [:erlang, :binary_to_atom]}, call_meta, [string, utf8]}
-  end
-
-  # Charlists with interpolations
-  defp do_normalize({{:., dot_meta, [List, :to_charlist]}, call_meta, [parts]}, state) do
-    parts =
-      Enum.map(parts, fn
-        {{:., part_dot_meta, [Kernel, :to_string]}, part_call_meta, args} ->
-          args = normalize_args(args, state)
-
-          {{:., part_dot_meta, [Kernel, :to_string]}, part_call_meta, args}
-
-        part ->
-          if state.escape do
-            maybe_escape_literal(part, state)
-          else
-            part
-          end
-      end)
-
-    {{:., dot_meta, [List, :to_charlist]}, call_meta, [parts]}
-  end
-
-  # Don't normalize the `Access` atom in access syntax
-  defp do_normalize({:., meta, [Access, :get]}, state) do
-    meta = patch_meta_line(meta, state.parent_meta)
-    {:., meta, [Access, :get]}
-  end
-
-  # Only normalize the left side of the dot operator
-  # The right hand side is an atom in the AST but it's not an atom literal, so
-  # it should not be wrapped
-  defp do_normalize({:., meta, [left, right]}, state) do
-    meta = patch_meta_line(meta, state.parent_meta)
-
-    left = do_normalize(left, %{state | parent_meta: meta})
-
-    {:., meta, [left, right]}
-  end
-
-  # A list of left to right arrows is not considered as a list literal, so it's not wrapped
-  defp do_normalize([{:->, _, [_ | _]} | _] = quoted, state) do
-    normalize_args(quoted, state)
-  end
-
-  # left -> right
-  defp do_normalize({:->, meta, [left, right]}, state) do
-    meta = patch_meta_line(meta, state.parent_meta)
-
-    left = normalize_args(left, %{state | parent_meta: meta})
-    right = do_normalize(right, %{state | parent_meta: meta})
-    {:->, meta, [left, right]}
-  end
-
-  # Maps
-  defp do_normalize({:%{}, meta, args}, state) when is_list(args) do
-    meta =
-      if meta == [] do
-        line = state.parent_meta[:line]
-        [line: line, closing: [line: line]]
-      else
-        meta
-      end
-
-    state = %{state | parent_meta: meta}
-
-    args =
-      case args do
-        [{:|, pipe_meta, [left, right]}] ->
-          left = do_normalize(left, state)
-          right = normalize_map_args(right, state)
-          [{:|, pipe_meta, [left, right]}]
-
-        [{_, _, _} = call] ->
-          [do_normalize(call, state)]
-
-        args ->
-          normalize_map_args(args, state)
-      end
-
-    {:%{}, meta, args}
-  end
-
-  # Sigils
-  defp do_normalize({sigil, meta, [{:<<>>, _, args} = string, modifiers]} = quoted, state)
-       when is_list(args) and is_atom(sigil) do
-    case Atom.to_string(sigil) do
-      <<"sigil_", _name>> ->
-        meta =
-          meta
-          |> patch_meta_line(state.parent_meta)
-          |> Keyword.put_new(:delimiter, "\"")
-
-        {sigil, meta, [do_normalize(string, %{state | parent_meta: meta}), modifiers]}
-
-      _ ->
-        normalize_call(quoted, state)
-    end
-  end
-
-  # Tuples
-  defp do_normalize({:{}, meta, args} = quoted, state) when is_list(args) do
-    {last_arg, args} = List.pop_at(args, -1)
-
-    if args != [] and match?([_ | _], last_arg) and keyword?(last_arg) do
-      args = normalize_args(args, state)
-      kw_list = normalize_kw_args(last_arg, state, true)
-      {:{}, meta, args ++ kw_list}
-    else
-      normalize_call(quoted, state)
-    end
-  end
-
-  # Module attributes
-  defp do_normalize({:@, meta, [{name, name_meta, [value]}]}, state) do
-    value =
-      cond do
-        keyword?(value) and value != [] ->
-          normalize_kw_args(value, state, true)
-
-        is_list(value) ->
-          normalize_literal(value, meta, state)
-
-        true ->
-          do_normalize(value, state)
-      end
-
-    {:@, meta, [{name, name_meta, [value]}]}
-  end
-
-  # Regular blocks
-  defp do_normalize({:__block__, meta, args}, state) when is_list(args) do
-    {:__block__, meta, normalize_args(args, state)}
-  end
-
-  # Calls
-  defp do_normalize({_, _, args} = quoted, state) when is_list(args) do
-    normalize_call(quoted, state)
-  end
-
-  # Vars
-  defp do_normalize({_, _, context} = quoted, _state) when is_atom(context) do
-    quoted
-  end
-
-  # Literals
-  defp do_normalize(quoted, state) do
-    normalize_literal(quoted, [], state)
-  end
-
-  # Numbers
-  defp normalize_literal(number, meta, state) when is_number(number) do
-    meta =
-      meta
-      |> Keyword.put_new(:token, inspect(number))
-      |> patch_meta_line(state.parent_meta)
-
-    {:__block__, meta, [number]}
-  end
-
-  # Atom, Strings
-  defp normalize_literal(literal, meta, state) when is_atom(literal) or is_binary(literal) do
-    meta = patch_meta_line(meta, state.parent_meta)
-    literal = maybe_escape_literal(literal, state)
-
-    if is_atom(literal) and Macro.classify_atom(literal) == :alias and
-         is_nil(meta[:delimiter]) do
-      segments =
-        case Atom.to_string(literal) do
-          "Elixir" ->
-            [:"Elixir"]
-
-          "Elixir." <> segments ->
-            segments
-            |> String.split(".")
-            |> Enum.map(&String.to_atom/1)
-        end
-
-      {:__aliases__, meta, segments}
-    else
-      {:__block__, meta, [literal]}
-    end
-  end
-
-  # 2-tuples
-  defp normalize_literal({left, right}, meta, state) do
-    meta = patch_meta_line(meta, state.parent_meta)
-    state = %{state | parent_meta: meta}
-
-    if match?([_ | _], right) and keyword?(right) do
-      {:__block__, meta, [{do_normalize(left, state), normalize_kw_args(right, state, true)}]}
-    else
-      {:__block__, meta, [{do_normalize(left, state), do_normalize(right, state)}]}
-    end
-  end
-
-  # Lists
-  defp normalize_literal(list, meta, state) when is_list(list) do
-    if list != [] and List.ascii_printable?(list) do
-      # It's a charlist
-      list =
-        if state.escape do
-          {string, _} = Code.Identifier.escape(IO.chardata_to_string(list), nil)
-          IO.iodata_to_binary(string) |> to_charlist()
-        else
-          list
-        end
-
-      meta =
-        meta
-        |> Keyword.put_new(:delimiter, "'")
-        |> patch_meta_line(state.parent_meta)
-
-      {:__block__, meta, [list]}
-    else
-      meta =
-        if line = state.parent_meta[:line] do
-          meta
-          |> Keyword.put_new(:closing, line: line)
-          |> patch_meta_line(state.parent_meta)
-        else
-          meta
-        end
-
-      {:__block__, meta, [normalize_kw_args(list, state, false)]}
-    end
-  end
-
-  # Probably an invalid value, wrap it and send it upstream
-  defp normalize_literal(quoted, meta, _state) do
-    {:__block__, meta, [quoted]}
-  end
-
-  defp normalize_call({form, meta, args}, state) do
-    meta = patch_meta_line(meta, state.parent_meta)
-    arity = length(args)
-
-    # Only normalize the form if it's a qualified call
-    form =
-      if is_atom(form) do
-        form
-      else
-        do_normalize(form, %{state | parent_meta: meta})
-      end
-
-    meta =
-      if is_nil(meta[:no_parens]) and is_nil(meta[:closing]) and is_nil(meta[:do]) and
-           not Code.Formatter.local_without_parens?(form, arity, state.locals_without_parens) do
-        [closing: [line: meta[:line]]] ++ meta
-      else
-        meta
-      end
-
-    cond do
-      Keyword.has_key?(meta, :do) or match?([{{:__block__, _, [:do]}, _} | _], List.last(args)) ->
-        # def foo do :ok end
-        # def foo, do: :ok
-        normalize_kw_blocks(form, meta, args, state)
-
-      match?([{:do, _} | _], List.last(args)) ->
-        # Non normalized kw blocks
-        line = state.parent_meta[:line]
-        meta = meta ++ [do: [line: line], end: [line: line]]
-        normalize_kw_blocks(form, meta, args, state)
-
-      allow_keyword?(form, arity) ->
-        args = normalize_args(args, %{state | parent_meta: state.parent_meta})
-        {last_arg, leading_args} = List.pop_at(args, -1, [])
-
-        last_args =
-          case last_arg do
-            {:__block__, _, [[{{:__block__, key_meta, _}, _} | _]] = last_args} ->
-              if key_meta[:format] == :keyword do
-                last_args
-              else
-                [last_arg]
-              end
-
-            [] ->
-              []
-
-            _ ->
-              [last_arg]
-          end
-
-        {form, meta, leading_args ++ last_args}
-
-      true ->
-        args = normalize_args(args, %{state | parent_meta: state.parent_meta})
-        {form, meta, args}
-    end
-  end
-
-  defp allow_keyword?(:when, 2), do: true
-  defp allow_keyword?(:{}, _), do: false
-  defp allow_keyword?(op, arity), do: not is_atom(op) or not Macro.operator?(op, arity)
-
-  defp normalize_bitstring({:<<>>, meta, parts} = quoted, state, escape_interpolation \\ false) do
-    meta = patch_meta_line(meta, state.parent_meta)
-
-    parts =
-      if interpolated?(quoted) do
-        normalize_interpolation_parts(parts, %{state | parent_meta: meta}, escape_interpolation)
-      else
-        state = %{state | parent_meta: meta}
-
-        Enum.map(parts, fn part ->
-          with {:"::", meta, [left, _]} <- part,
-               true <- meta[:inferred_bitstring_spec] do
-            do_normalize(left, state)
-          else
-            _ -> do_normalize(part, state)
-          end
-        end)
-      end
-
-    {:<<>>, meta, parts}
-  end
-
-  defp normalize_interpolation_parts(parts, state, escape_interpolation) do
-    Enum.map(parts, fn
-      {:"::", interpolation_meta,
-       [
-         {{:., dot_meta, [Kernel, :to_string]}, middle_meta, [middle]},
-         {:binary, binary_meta, context}
-       ]} ->
-        middle = do_normalize(middle, %{state | parent_meta: dot_meta})
-
-        {:"::", interpolation_meta,
-         [
-           {{:., dot_meta, [Kernel, :to_string]}, middle_meta, [middle]},
-           {:binary, binary_meta, context}
-         ]}
-
-      part ->
-        if escape_interpolation do
-          maybe_escape_literal(part, state)
-        else
-          part
-        end
-    end)
-  end
-
-  defp normalize_map_args(args, state) do
-    Enum.map(normalize_kw_args(args, state, false), fn
-      {:__block__, _, [{_, _} = pair]} -> pair
-      pair -> pair
-    end)
-  end
-
-  defp normalize_kw_blocks(form, meta, args, state) do
-    {kw_blocks, leading_args} = List.pop_at(args, -1)
-
-    kw_blocks =
-      Enum.map(kw_blocks, fn {tag, block} ->
-        block = do_normalize(block, %{state | parent_meta: meta})
-
-        block =
-          case block do
-            {_, _, [[{:->, _, _} | _] = block]} -> block
-            block -> block
-          end
-
-        # Only wrap the tag if it isn't already wrapped
-        tag =
-          case tag do
-            {:__block__, _, _} -> tag
-            _ -> {:__block__, [line: meta[:line]], [tag]}
-          end
-
-        {tag, block}
-      end)
-
-    leading_args = normalize_args(leading_args, %{state | parent_meta: meta})
-    {form, meta, leading_args ++ [kw_blocks]}
-  end
-
-  defp normalize_kw_args(elems, state, keyword?)
-
-  defp normalize_kw_args(
-         [{{:__block__, key_meta, [key]}, value} = first | rest] = current,
-         state,
-         keyword?
-       )
-       when is_atom(key) do
-    keyword? = keyword? or keyword?(current)
-
-    first =
-      if key_meta[:format] == :keyword and not keyword? do
-        key_meta = Keyword.delete(key_meta, :format)
-        line = key_meta[:line] || meta_line(state)
-        {:__block__, [line: line], [{{:__block__, key_meta, [key]}, value}]}
-      else
-        first
-      end
-
-    [first | normalize_kw_args(rest, state, keyword?)]
-  end
-
-  defp normalize_kw_args([{left, right} | rest] = current, state, keyword?) do
-    keyword? = keyword? or keyword?(current)
-
-    left =
-      if keyword? do
-        meta = [format: :keyword] ++ meta_line(state)
-        {:__block__, meta, [maybe_escape_literal(left, state)]}
-      else
-        do_normalize(left, state)
-      end
-
-    right = do_normalize(right, state)
-
-    pair =
-      with {:__block__, meta, _} <- left,
-           :keyword <- meta[:format] do
-        {left, right}
-      else
-        _ -> {:__block__, meta_line(state), [{left, right}]}
-      end
-
-    [pair | normalize_kw_args(rest, state, keyword?)]
-  end
-
-  defp normalize_kw_args([first | rest], state, keyword?) do
-    [do_normalize(first, state) | normalize_kw_args(rest, state, keyword?)]
-  end
-
-  defp normalize_kw_args([], _state, _keyword?) do
-    []
-  end
-
-  defp normalize_args(args, state) do
-    Enum.map(args, &do_normalize(&1, state))
-  end
-
-  defp maybe_escape_literal(string, %{escape: true}) when is_binary(string) do
-    {string, _} = Code.Identifier.escape(string, nil)
-    IO.iodata_to_binary(string)
-  end
-
-  defp maybe_escape_literal(atom, %{escape: true} = state) when is_atom(atom) do
-    atom
-    |> Atom.to_string()
-    |> maybe_escape_literal(state)
-    |> String.to_atom()
-  end
-
-  defp maybe_escape_literal(term, _) do
-    term
-  end
-
-  # Check if we have an interpolated string.
-  defp interpolated?({:<<>>, _, [_ | _] = parts}) do
-    Enum.all?(parts, fn
-      {:"::", _, [{{:., _, [Kernel, :to_string]}, _, [_]}, {:binary, _, _}]} -> true
-      binary when is_binary(binary) -> true
-      _ -> false
-    end)
-  end
-
-  defp interpolated?(_) do
-    false
-  end
-
-  defp patch_meta_line(meta, parent_meta) do
-    with nil <- meta[:line],
-         line when is_integer(line) <- parent_meta[:line] do
-      [line: line] ++ meta
-    else
-      _ -> meta
-    end
-  end
-
-  defp meta_line(state) do
-    if line = state.parent_meta[:line] do
-      [line: line]
-    else
-      []
-    end
-  end
-
-  defp keyword?([{{:__block__, key_meta, [key]}, _} | rest]) when is_atom(key) do
-    if key_meta[:format] == :keyword do
-      keyword?(rest)
-    else
-      false
-    end
-  end
-
-  defp keyword?([{key, _value} | rest]) when is_atom(key) do
-    case Atom.to_charlist(key) do
-      'Elixir.' ++ _ -> false
-      _ -> keyword?(rest)
-    end
-  end
-
-  defp keyword?([]), do: true
-  defp keyword?(_other), do: false
-end

lib/elixir/lib/code/typespec.ex

@@ -7,9 +7,9 @@ defmodule Code.Typespec do
   @spec spec_to_quoted(atom, tuple) :: {atom, keyword, [Macro.t()]}
   def spec_to_quoted(name, spec)
 
-  def spec_to_quoted(name, {:type, anno, :fun, [{:type, _, :product, args}, result]})
+  def spec_to_quoted(name, {:type, line, :fun, [{:type, _, :product, args}, result]})
       when is_atom(name) do
-    meta = meta(anno)
+    meta = [line: line]
     body = {name, meta, Enum.map(args, &typespec_to_quoted/1)}
 
     vars =
@@ -27,13 +27,11 @@ defmodule Code.Typespec do
     end
   end
 
-  def spec_to_quoted(name, {:type, anno, :fun, []}) when is_atom(name) do
-    meta = meta(anno)
-    {:"::", meta, [{name, meta, []}, quote(do: term)]}
+  def spec_to_quoted(name, {:type, line, :fun, []}) when is_atom(name) do
+    {:"::", [line: line], [{name, [line: line], []}, quote(do: term)]}
   end
 
-  def spec_to_quoted(name, {:type, anno, :bounded_fun, [type, constrs]}) when is_atom(name) do
-    meta = meta(anno)
+  def spec_to_quoted(name, {:type, line, :bounded_fun, [type, constrs]}) when is_atom(name) do
     {:type, _, :fun, [{:type, _, :product, args}, result]} = type
 
     guards =
@@ -41,6 +39,7 @@ defmodule Code.Typespec do
         {erl_to_ex_var(var), typespec_to_quoted(type)}
       end
 
+    meta = [line: line]
     ignore_vars = Keyword.keys(guards)
 
     vars =
@@ -53,7 +52,7 @@ defmodule Code.Typespec do
     args = for arg <- args, do: typespec_to_quoted(arg)
 
     when_args = [
-      {:"::", meta, [{name, meta, args}, typespec_to_quoted(result)]},
+      {:"::", meta, [{name, [line: line], args}, typespec_to_quoted(result)]},
       guards ++ vars
     ]
 
@@ -174,11 +173,9 @@ defmodule Code.Typespec do
   end
 
   defp get_module_and_beam(module) when is_atom(module) do
-    with {^module, beam, _filename} <- :code.get_object_code(module),
-         {:ok, ^module} <- beam |> :beam_lib.info() |> Keyword.fetch(:module) do
-      {module, beam}
-    else
-      _ -> :error
+    case :code.get_object_code(module) do
+      {^module, beam, _filename} -> {module, beam}
+      :error -> :error
     end
   end
 
@@ -191,27 +188,27 @@ defmodule Code.Typespec do
 
   ## To AST conversion
 
-  defp collect_vars({:ann_type, _anno, args}) when is_list(args) do
+  defp collect_vars({:ann_type, _line, args}) when is_list(args) do
     []
   end
 
-  defp collect_vars({:type, _anno, _kind, args}) when is_list(args) do
+  defp collect_vars({:type, _line, _kind, args}) when is_list(args) do
     Enum.flat_map(args, &collect_vars/1)
   end
 
-  defp collect_vars({:remote_type, _anno, args}) when is_list(args) do
+  defp collect_vars({:remote_type, _line, args}) when is_list(args) do
     Enum.flat_map(args, &collect_vars/1)
   end
 
-  defp collect_vars({:typed_record_field, _anno, type}) do
+  defp collect_vars({:typed_record_field, _line, type}) do
     collect_vars(type)
   end
 
-  defp collect_vars({:paren_type, _anno, [type]}) do
+  defp collect_vars({:paren_type, _line, [type]}) do
     collect_vars(type)
   end
 
-  defp collect_vars({:var, _anno, var}) do
+  defp collect_vars({:var, _line, var}) do
     [erl_to_ex_var(var)]
   end
 
@@ -219,48 +216,48 @@ defmodule Code.Typespec do
     []
   end
 
-  defp typespec_to_quoted({:user_type, anno, name, args}) do
+  defp typespec_to_quoted({:user_type, line, name, args}) do
     args = for arg <- args, do: typespec_to_quoted(arg)
-    {name, meta(anno), args}
+    {name, [line: line], args}
   end
 
-  defp typespec_to_quoted({:type, anno, :tuple, :any}) do
-    {:tuple, meta(anno), []}
+  defp typespec_to_quoted({:type, line, :tuple, :any}) do
+    {:tuple, [line: line], []}
   end
 
-  defp typespec_to_quoted({:type, anno, :tuple, args}) do
+  defp typespec_to_quoted({:type, line, :tuple, args}) do
     args = for arg <- args, do: typespec_to_quoted(arg)
-    {:{}, meta(anno), args}
+    {:{}, [line: line], args}
   end
 
-  defp typespec_to_quoted({:type, _anno, :list, [{:type, _, :union, unions} = arg]}) do
+  defp typespec_to_quoted({:type, _line, :list, [{:type, _, :union, unions} = arg]}) do
     case unpack_typespec_kw(unions, []) do
       {:ok, ast} -> ast
       :error -> [typespec_to_quoted(arg)]
     end
   end
 
-  defp typespec_to_quoted({:type, anno, :list, []}) do
-    {:list, meta(anno), []}
+  defp typespec_to_quoted({:type, line, :list, []}) do
+    {:list, [line: line], []}
   end
 
-  defp typespec_to_quoted({:type, _anno, :list, [arg]}) do
+  defp typespec_to_quoted({:type, _line, :list, [arg]}) do
     [typespec_to_quoted(arg)]
   end
 
-  defp typespec_to_quoted({:type, anno, :nonempty_list, []}) do
-    [{:..., meta(anno), nil}]
+  defp typespec_to_quoted({:type, line, :nonempty_list, []}) do
+    [{:..., [line: line], nil}]
   end
 
-  defp typespec_to_quoted({:type, anno, :nonempty_list, [arg]}) do
-    [typespec_to_quoted(arg), {:..., meta(anno), nil}]
+  defp typespec_to_quoted({:type, line, :nonempty_list, [arg]}) do
+    [typespec_to_quoted(arg), {:..., [line: line], nil}]
   end
 
-  defp typespec_to_quoted({:type, anno, :map, :any}) do
-    {:map, meta(anno), []}
+  defp typespec_to_quoted({:type, line, :map, :any}) do
+    {:map, [line: line], []}
   end
 
-  defp typespec_to_quoted({:type, anno, :map, fields}) do
+  defp typespec_to_quoted({:type, line, :map, fields}) do
     fields =
       Enum.map(fields, fn
         {:type, _, :map_field_assoc, :any} ->
@@ -278,17 +275,16 @@ defmodule Code.Typespec do
 
     case List.keytake(fields, :__struct__, 0) do
       {{:__struct__, struct}, fields_pruned} when is_atom(struct) and struct != nil ->
-        map_pruned = {:%{}, meta(anno), fields_pruned}
-        {:%, meta(anno), [struct, map_pruned]}
+        map_pruned = {:%{}, [line: line], fields_pruned}
+        {:%, [line: line], [struct, map_pruned]}
 
       _ ->
-        {:%{}, meta(anno), fields}
+        {:%{}, [line: line], fields}
     end
   end
 
-  defp typespec_to_quoted({:type, anno, :binary, [arg1, arg2]}) do
+  defp typespec_to_quoted({:type, line, :binary, [arg1, arg2]}) do
     [arg1, arg2] = for arg <- [arg1, arg2], do: typespec_to_quoted(arg)
-    line = meta(anno)[:line]
 
     case {typespec_to_quoted(arg1), typespec_to_quoted(arg2)} do
       {arg1, 0} ->
@@ -302,57 +298,57 @@ defmodule Code.Typespec do
     end
   end
 
-  defp typespec_to_quoted({:type, anno, :union, args}) do
+  defp typespec_to_quoted({:type, line, :union, args}) do
     args = for arg <- args, do: typespec_to_quoted(arg)
-    Enum.reduce(Enum.reverse(args), fn arg, expr -> {:|, meta(anno), [arg, expr]} end)
+    Enum.reduce(Enum.reverse(args), fn arg, expr -> {:|, [line: line], [arg, expr]} end)
   end
 
-  defp typespec_to_quoted({:type, anno, :fun, [{:type, _, :product, args}, result]}) do
+  defp typespec_to_quoted({:type, line, :fun, [{:type, _, :product, args}, result]}) do
     args = for arg <- args, do: typespec_to_quoted(arg)
-    [{:->, meta(anno), [args, typespec_to_quoted(result)]}]
+    [{:->, [line: line], [args, typespec_to_quoted(result)]}]
   end
 
-  defp typespec_to_quoted({:type, anno, :fun, [args, result]}) do
-    [{:->, meta(anno), [[typespec_to_quoted(args)], typespec_to_quoted(result)]}]
+  defp typespec_to_quoted({:type, line, :fun, [args, result]}) do
+    [{:->, [line: line], [[typespec_to_quoted(args)], typespec_to_quoted(result)]}]
   end
 
-  defp typespec_to_quoted({:type, anno, :fun, []}) do
-    typespec_to_quoted({:type, anno, :fun, [{:type, anno, :any}, {:type, anno, :any, []}]})
+  defp typespec_to_quoted({:type, line, :fun, []}) do
+    typespec_to_quoted({:type, line, :fun, [{:type, line, :any}, {:type, line, :any, []}]})
   end
 
-  defp typespec_to_quoted({:type, anno, :range, [left, right]}) do
-    {:.., meta(anno), [typespec_to_quoted(left), typespec_to_quoted(right)]}
+  defp typespec_to_quoted({:type, line, :range, [left, right]}) do
+    {:.., [line: line], [typespec_to_quoted(left), typespec_to_quoted(right)]}
   end
 
-  defp typespec_to_quoted({:type, _anno, nil, []}) do
+  defp typespec_to_quoted({:type, _line, nil, []}) do
     []
   end
 
-  defp typespec_to_quoted({:type, anno, name, args}) do
+  defp typespec_to_quoted({:type, line, name, args}) do
     args = for arg <- args, do: typespec_to_quoted(arg)
-    {name, meta(anno), args}
+    {name, [line: line], args}
   end
 
-  defp typespec_to_quoted({:var, anno, var}) do
-    {erl_to_ex_var(var), meta(anno), nil}
+  defp typespec_to_quoted({:var, line, var}) do
+    {erl_to_ex_var(var), [line: line], nil}
   end
 
-  defp typespec_to_quoted({:op, anno, op, arg}) do
-    {op, meta(anno), [typespec_to_quoted(arg)]}
+  defp typespec_to_quoted({:op, line, op, arg}) do
+    {op, [line: line], [typespec_to_quoted(arg)]}
   end
 
-  defp typespec_to_quoted({:remote_type, anno, [mod, name, args]}) do
-    remote_type(anno, mod, name, args)
+  defp typespec_to_quoted({:remote_type, line, [mod, name, args]}) do
+    remote_type(line, mod, name, args)
   end
 
-  defp typespec_to_quoted({:ann_type, anno, [var, type]}) do
-    {:"::", meta(anno), [typespec_to_quoted(var), typespec_to_quoted(type)]}
+  defp typespec_to_quoted({:ann_type, line, [var, type]}) do
+    {:"::", [line: line], [typespec_to_quoted(var), typespec_to_quoted(type)]}
   end
 
   defp typespec_to_quoted(
-         {:typed_record_field, {:record_field, anno1, {:atom, anno2, name}}, type}
+         {:typed_record_field, {:record_field, line, {:atom, line1, name}}, type}
        ) do
-    typespec_to_quoted({:ann_type, anno1, [{:var, anno2, name}, type]})
+    typespec_to_quoted({:ann_type, line, [{:var, line1, name}, type]})
   end
 
   defp typespec_to_quoted({:type, _, :any}) do
@@ -363,7 +359,7 @@ defmodule Code.Typespec do
     typespec_to_quoted(type)
   end
 
-  defp typespec_to_quoted({type, _anno, atom}) when is_atom(type) do
+  defp typespec_to_quoted({type, _line, atom}) when is_atom(type) do
     atom
   end
 
@@ -371,30 +367,30 @@ defmodule Code.Typespec do
 
   ## Helpers
 
-  defp remote_type(anno, {:atom, _, :elixir}, {:atom, _, :charlist}, []) do
-    typespec_to_quoted({:type, anno, :charlist, []})
+  defp remote_type(line, {:atom, _, :elixir}, {:atom, _, :charlist}, []) do
+    typespec_to_quoted({:type, line, :charlist, []})
   end
 
-  defp remote_type(anno, {:atom, _, :elixir}, {:atom, _, :nonempty_charlist}, []) do
-    typespec_to_quoted({:type, anno, :nonempty_charlist, []})
+  defp remote_type(line, {:atom, _, :elixir}, {:atom, _, :nonempty_charlist}, []) do
+    typespec_to_quoted({:type, line, :nonempty_charlist, []})
   end
 
-  defp remote_type(anno, {:atom, _, :elixir}, {:atom, _, :struct}, []) do
-    typespec_to_quoted({:type, anno, :struct, []})
+  defp remote_type(line, {:atom, _, :elixir}, {:atom, _, :struct}, []) do
+    typespec_to_quoted({:type, line, :struct, []})
   end
 
-  defp remote_type(anno, {:atom, _, :elixir}, {:atom, _, :as_boolean}, [arg]) do
-    typespec_to_quoted({:type, anno, :as_boolean, [arg]})
+  defp remote_type(line, {:atom, _, :elixir}, {:atom, _, :as_boolean}, [arg]) do
+    typespec_to_quoted({:type, line, :as_boolean, [arg]})
   end
 
-  defp remote_type(anno, {:atom, _, :elixir}, {:atom, _, :keyword}, args) do
-    typespec_to_quoted({:type, anno, :keyword, args})
+  defp remote_type(line, {:atom, _, :elixir}, {:atom, _, :keyword}, args) do
+    typespec_to_quoted({:type, line, :keyword, args})
   end
 
-  defp remote_type(anno, mod, name, args) do
+  defp remote_type(line, mod, name, args) do
     args = for arg <- args, do: typespec_to_quoted(arg)
-    dot = {:., meta(anno), [typespec_to_quoted(mod), typespec_to_quoted(name)]}
-    {dot, meta(anno), args}
+    dot = {:., [line: line], [typespec_to_quoted(mod), typespec_to_quoted(name)]}
+    {dot, [line: line], args}
   end
 
   defp erl_to_ex_var(var) do
@@ -418,6 +414,4 @@ defmodule Code.Typespec do
   defp unpack_typespec_kw(_, _acc) do
     :error
   end
-
-  defp meta(anno), do: [line: :erl_anno.line(anno)]
 end

lib/elixir/lib/collectable.ex

@@ -17,8 +17,8 @@ defprotocol Collectable do
 
   This design is intentional. `Enumerable` was designed to support infinite
   collections, resources and other structures with fixed shape. For example,
-  it doesn't make sense to insert values into a `Range`, as it has a
-  fixed shape where only the range limits and step are stored.
+  it doesn't make sense to insert values into a range, as it has a fixed
+  shape where just the range limits are stored.
 
   The `Collectable` module was designed to fill the gap left by the
   `Enumerable` protocol. `Collectable.into/1` can be seen as the opposite of
@@ -35,7 +35,7 @@ defprotocol Collectable do
       ...>   collector_fun.(acc, {:cont, elem})
       ...> end)
       iex> collector_fun.(updated_acc, :done)
-      MapSet.new([1, 2, 3])
+      #MapSet<[1, 2, 3]>
 
   To show how the protocol can be implemented, we can again look at the
   simplified implementation for `MapSet`. In this implementation "collecting" elements
@@ -63,7 +63,7 @@ defprotocol Collectable do
   So now we can call `Enum.into/2`:
 
       iex> Enum.into([1, 2, 3], MapSet.new())
-      MapSet.new([1, 2, 3])
+      #MapSet<[1, 2, 3]>
 
   """
 
@@ -94,11 +94,10 @@ end
 
 defimpl Collectable, for: List do
   def into(list) do
-    # TODO: Change the behaviour so the into always comes last on Elixir v2.0
     if list != [] do
       IO.warn(
         "the Collectable protocol is deprecated for non-empty lists. The behaviour of " <>
-          "Enum.into/2 and \"for\" comprehensions with an :into option is incorrect " <>
+          "things like Enum.into/2 or \"for\" comprehensions with an :into option is incorrect " <>
           "when collecting into non-empty lists. If you're collecting into a non-empty keyword " <>
           "list, consider using Keyword.merge/2 instead. If you're collecting into a non-empty " <>
           "list, consider concatenating the two lists with the ++ operator."

lib/elixir/lib/config.ex

@@ -34,12 +34,12 @@ defmodule Config do
   `Config` also provides a low-level API for evaluating and reading
   configuration, under the `Config.Reader` module.
 
-  > **Important:** if you are writing a library to be used by other developers,
-  > it is generally recommended to avoid the application environment, as the
-  > application environment is effectively a global storage. Also note that
-  > the `config/config.exs` of a library is not evaluated when the library is
-  > used as a dependency, as configuration is always meant to configure the
-  > current project. For more information, read our [library guidelines](library-guidelines.md).
+  **Important:** if you are writing a library to be used by other developers,
+  it is generally recommended to avoid the application environment, as the
+  application environment is effectively a global storage. Also note that
+  the `config/config.exs` of a library is not evaluated when the library is
+  used as a dependency, as configuration is always meant to configure the
+  current project. For more information, read our [library guidelines](library-guidelines.md).
 
   ## Migrating from `use Mix.Config`
 
@@ -62,27 +62,7 @@ defmodule Config do
         import_config config
       end
 
-  The last step is to replace all `Mix.env()` calls in the config files with `config_env()`.
-
-  Keep in mind you must also avoid using `Mix.env()` inside your project files.
-  To check the environment at _runtime_, you may add a configuration key:
-
-      # config.exs
-      ...
-      config :my_app, env: config_env()
-
-  Then, in other scripts and modules, you may get the environment with
-  `Application.fetch_env!/2`:
-
-      # router.exs
-      ...
-      if Application.fetch_env!(:my_app, :env) == :prod do
-        ...
-      end
-
-  The only files where you may access functions from the `Mix` module are
-  the `mix.exs` file and inside custom Mix tasks, which always within the
-  `Mix.Tasks` namespace.
+  The last step is to replace all `Mix.env()` calls by `config_env()`.
 
   ## config/runtime.exs
 
@@ -95,7 +75,7 @@ defmodule Config do
   @config_key {__MODULE__, :config}
   @imports_key {__MODULE__, :imports}
 
-  defp get_opts!(), do: Process.get(@opts_key) || raise_improper_use!()
+  defp get_opts!(), do: Process.get(@opts_key)
   defp put_opts(value), do: Process.put(@opts_key, value)
   defp delete_opts(), do: Process.delete(@opts_key)
 
@@ -122,9 +102,8 @@ defmodule Config do
 
   The given `opts` are merged into the existing configuration
   for the given `root_key`. Conflicting keys are overridden by the
-  ones specified in `opts`, unless they are keywords, which are
-  deep merged recursively. For example, the application configuration
-  below
+  ones specified in `opts`. For example, the application
+  configuration below
 
       config :logger,
         level: :warn,
@@ -159,30 +138,21 @@ defmodule Config do
 
   The given `opts` are merged into the existing values for `key`
   in the given `root_key`. Conflicting keys are overridden by the
-  ones specified in `opts`, unless they are keywords, which are
-  deep merged recursively. For example, the application configuration
-  below
+  ones specified in `opts`. For example, the application
+  configuration below
 
       config :ecto, Repo,
         log_level: :warn,
-        adapter: Ecto.Adapters.Postgres,
-        metadata: [read_only: true]
+        adapter: Ecto.Adapters.Postgres
 
       config :ecto, Repo,
         log_level: :info,
-        pool_size: 10,
-        metadata: [replica: true]
+        pool_size: 10
 
   will have a final value of the configuration for the `Repo`
   key in the `:ecto` application of:
 
-      Application.get_env(:ecto, Repo)
-      #=> [
-      #=>   log_level: :info,
-      #=>   pool_size: 10,
-      #=>   adapter: Ecto.Adapters.Postgres,
-      #=>   metadata: [read_only: true, replica: true]
-      #=> ]
+      [log_level: :info, pool_size: 10, adapter: Ecto.Adapters.Postgres]
 
   """
   @doc since: "1.9.0"
@@ -321,6 +291,8 @@ defmodule Config do
         :ok
     end
 
+    # TODO: Emit a warning if Mix.env() is found in said files in Elixir v1.15.
+    # Note this won't be a deprecation warning as it will always be emitted.
     Code.eval_string(contents, [], file: file)
   end
 

lib/elixir/lib/config/provider.ex

@@ -20,8 +20,8 @@ defmodule Config.Provider do
 
   For example, imagine you want to list some basic configuration
   on Mix's built-in `config/runtime.exs` file, but you also want
-  to support additional configuration files. To do so, you can add
-  this inside the `def project` portion of  your `mix.exs`:
+  some additional configuration files. To do so, you can do this
+  in your `mix.exs`:
 
       releases: [
         demo: [
@@ -42,8 +42,7 @@ defmodule Config.Provider do
       simply copy it to the release root as a step in your deployment
 
   Now once the system boots, it will load both `config/runtime.exs`
-  and `extra_config.exs` early in the boot process. You can learn
-  more options on `Config.Reader`.
+  and `extra_config.exs` early in the boot process.
 
   ## Custom config provider
 
@@ -56,10 +55,8 @@ defmodule Config.Provider do
         @behaviour Config.Provider
 
         # Let's pass the path to the JSON file as config
-        @impl true
         def init(path) when is_binary(path), do: path
 
-        @impl true
         def load(config, path) do
           # We need to start any app we may depend on.
           {:ok, _} = Application.ensure_all_started(:jason)
@@ -230,6 +227,7 @@ defmodule Config.Provider do
   end
 
   defp boot_providers(path, provider, reboot_config, reboot_fun) do
+    validate_no_cyclic_boot!(path)
     original_config = read_config!(path)
 
     config =
@@ -341,7 +339,8 @@ defmodule Config.Provider do
   defp restart_and_sleep() do
     mode = Application.get_env(:elixir, @reboot_mode_key)
 
-    if mode in [:embedded, :interactive] do
+    # TODO: Remove otp_release check once we require Erlang/OTP 23+
+    if :erlang.system_info(:otp_release) >= '23' and mode in [:embedded, :interactive] do
       :init.restart(mode: mode)
     else
       :init.restart()
@@ -353,6 +352,14 @@ defmodule Config.Provider do
   defp booted_value(%{prune_runtime_sys_config_after_boot: true}, path), do: {:booted, path}
   defp booted_value(%{prune_runtime_sys_config_after_boot: false}, _path), do: {:booted, nil}
 
+  defp validate_no_cyclic_boot!(path) do
+    if System.get_env("ELIXIR_CONFIG_PROVIDER_BOOTED") do
+      bad_path_abort("Got infinite loop when running Config.Provider", path)
+    else
+      System.put_env("ELIXIR_CONFIG_PROVIDER_BOOTED", "1")
+    end
+  end
+
   defp read_config!(path) do
     case :file.consult(path) do
       {:ok, [inner]} ->
@@ -409,7 +416,7 @@ defmodule Config.Provider do
   end
 
   defp abort(msg) do
-    IO.puts("ERROR! " <> msg)
+    IO.puts(:stderr, "ERROR! " <> msg)
     :erlang.raise(:error, "aborting boot", [{Config.Provider, :boot, 2, []}])
   end
 end

lib/elixir/lib/config/reader.ex

@@ -4,23 +4,15 @@ defmodule Config.Reader do
 
   ## As a provider
 
-  `Config.Reader` can also be used as a `Config.Provider`. A config
-  provider is used during releases to customize how applications are
-  configured. When used as a provider, it expects a single argument:
-  the configuration path (as outlined in `t:Config.Provider.config_path/0`)
-  for the file to be read and loaded during the system boot.
+  `Config.Reader` can also be used as a `Config.Provider`. When used
+  as a provider, it expects a single argument: the configuration path
+  (as outlined in `t:Config.Provider.config_path/0`) for the file to
+  be read and loaded during the system boot.
 
   For example, if you expect the target system to have a config file
-  in an absolute path, you can add this inside the `def project` portion
-  of  your `mix.exs`:
+  in an absolute path, you can configure your `mix release` as:
 
-      releases: [
-        demo: [
-          config_providers: [
-            {Config.Reader, "/etc/config.exs"}
-          ]
-        ]
-      ]
+      config_providers: [{Config.Reader, "/etc/config.exs"}]
 
   Or if you want to read a custom path inside the release:
 
@@ -36,8 +28,10 @@ defmodule Config.Reader do
          imports: :disabled}
       ]
 
-  Remember Mix already loads `config/runtime.exs` by default.
-  For more examples and scenarios, see the `Config.Provider` module.
+  Note by default Mix releases supports runtime configuration via
+  a `config/runtime.exs`. If a `config/runtime.exs` exists in your
+  application, it is automatically copied inside the release and
+  automatically set as a config provider.
   """
 
   @behaviour Config.Provider

lib/elixir/lib/dict.ex

@@ -23,7 +23,7 @@ defmodule Dict do
     import Kernel, except: [size: 1]
 
     if __CALLER__.module != HashDict do
-      IO.warn("use Dict is deprecated. " <> unquote(message), __CALLER__)
+      IO.warn("use Dict is deprecated. " <> unquote(message), Macro.Env.stacktrace(__CALLER__))
     end
 
     quote do

lib/elixir/lib/dynamic_supervisor.ex

@@ -1,21 +1,21 @@
 defmodule DynamicSupervisor do
   @moduledoc ~S"""
-  A supervisor optimized to only start children dynamically.
+  A supervisor that starts children dynamically.
 
   The `Supervisor` module was designed to handle mostly static children
   that are started in the given order when the supervisor starts. A
   `DynamicSupervisor` starts with no children. Instead, children are
-  started on demand via `start_child/2` and there is no ordering between
-  children. This allows the `DynamicSupervisor` to hold millions of
-  children by using efficient data structures and to execute certain
-  operations, such as shutting down, concurrently.
+  started on demand via `start_child/2`. When a dynamic supervisor
+  terminates, all children are shut down at the same time, with no guarantee
+  of ordering.
 
   ## Examples
 
-  A dynamic supervisor is started with no children and often a name:
+  A dynamic supervisor is started with no children, a supervision strategy
+  (the only strategy currently supported is `:one_for_one`), and a name:
 
       children = [
-        {DynamicSupervisor, name: MyApp.DynamicSupervisor}
+        {DynamicSupervisor, strategy: :one_for_one, name: MyApp.DynamicSupervisor}
       ]
 
       Supervisor.start_link(children, strategy: :one_for_one)
@@ -37,46 +37,6 @@ defmodule DynamicSupervisor do
       DynamicSupervisor.count_children(MyApp.DynamicSupervisor)
       #=> %{active: 2, specs: 2, supervisors: 0, workers: 2}
 
-  ## Scalability and partitioning
-
-  The `DynamicSupervisor` is a single process responsible for starting
-  other processes. In some applications, the `DynamicSupervisor` may
-  become a bottleneck. To address this, you can start multiple instances
-  of the `DynamicSupervisor` and then pick a "random" instance to start
-  the child on.
-
-  Instead of:
-
-      children = [
-        {DynamicSupervisor, name: MyApp.DynamicSupervisor}
-      ]
-
-  and:
-
-      DynamicSupervisor.start_child(MyApp.DynamicSupervisor, {Agent, fn -> %{} end})
-
-  You can do this:
-
-      children = [
-        {PartitionSupervisor,
-         child_spec: DynamicSupervisor,
-         name: MyApp.DynamicSupervisors}
-      ]
-
-  and then:
-
-      DynamicSupervisor.start_child(
-        {:via, PartitionSupervisor, {MyApp.DynamicSupervisors, self()}},
-        {Agent, fn -> %{} end}
-      )
-
-  In the code above, we start a partition supervisor that will by default
-  start a dynamic supervisor for each core in your machine. Then, instead
-  of calling the `DynamicSupervisor` by name, you call it through the
-  partition supervisor, using `self()` as the routing key. This means each
-  process will be assigned one of the existing dynamic supervisors.
-  Read the `PartitionSupervisor` docs for more information.
-
   ## Module-based supervisors
 
   Similar to `Supervisor`, dynamic supervisors also support module-based
@@ -272,74 +232,12 @@ defmodule DynamicSupervisor do
   @doc """
   Starts a supervisor with the given options.
 
-  This function is typically not invoked directly, instead it is invoked
-  when using a `DynamicSupervisor` as a child of another supervisor:
+  The `:strategy` is a required option and the currently supported
+  value is `:one_for_one`. The remaining options can be found in the
+  `init/1` docs.
 
-      children = [
-        {DynamicSupervisor, name: MySupervisor}
-      ]
-
-  If the supervisor is successfully spawned, this function returns
-  `{:ok, pid}`, where `pid` is the PID of the supervisor. If the supervisor
-  is given a name and a process with the specified name already exists,
-  the function returns `{:error, {:already_started, pid}}`, where `pid`
-  is the PID of that process.
-
-  Note that a supervisor started with this function is linked to the parent
-  process and exits not only on crashes but also if the parent process exits
-  with `:normal` reason.
-
-  ## Options
-
-    * `:name` - registers the supervisor under the given name.
-      The supported values are described under the "Name registration"
-      section in the `GenServer` module docs.
-
-    * `:strategy` - the restart strategy option. The only supported
-      value is `:one_for_one` which means that no other child is
-      terminated if a child process terminates. You can learn more
-      about strategies in the `Supervisor` module docs.
-
-    * `:max_restarts` - the maximum number of restarts allowed in
-      a time frame. Defaults to `3`.
-
-    * `:max_seconds` - the time frame in which `:max_restarts` applies.
-      Defaults to `5`.
-
-    * `:max_children` - the maximum amount of children to be running
-      under this supervisor at the same time. When `:max_children` is
-      exceeded, `start_child/2` returns `{:error, :max_children}`. Defaults
-      to `:infinity`.
-
-    * `:extra_arguments` - arguments that are prepended to the arguments
-      specified in the child spec given to `start_child/2`. Defaults to
-      an empty list.
-
-  """
-  @doc since: "1.6.0"
-  @spec start_link([option | init_option]) :: Supervisor.on_start()
-  def start_link(options) when is_list(options) do
-    keys = [:extra_arguments, :max_children, :max_seconds, :max_restarts, :strategy]
-    {sup_opts, start_opts} = Keyword.split(options, keys)
-    start_link(Supervisor.Default, init(sup_opts), start_opts)
-  end
-
-  @doc """
-  Starts a module-based supervisor process with the given `module` and `init_arg`.
-
-  To start the supervisor, the `c:init/1` callback will be invoked in the given
-  `module`, with `init_arg` as its argument. The `c:init/1` callback must return a
-  supervisor specification which can be created with the help of the `init/1`
-  function.
-
-  If the `c:init/1` callback returns `:ignore`, this function returns
-  `:ignore` as well and the supervisor terminates with reason `:normal`.
-  If it fails or returns an incorrect value, this function returns
-  `{:error, term}` where `term` is a term with information about the
-  error, and the supervisor terminates with reason `term`.
-
-  The `:name` option can also be given in order to register a supervisor
-  name, the supported values are described in the "Name registration"
+  The `:name` option can also be used to register a supervisor name.
+  The supported values are described under the "Name registration"
   section in the `GenServer` module docs.
 
   If the supervisor is successfully spawned, this function returns
@@ -353,9 +251,35 @@ defmodule DynamicSupervisor do
   with `:normal` reason.
   """
   @doc since: "1.6.0"
+  @spec start_link([option | init_option]) :: Supervisor.on_start()
+  def start_link(options) when is_list(options) do
+    keys = [:extra_arguments, :max_children, :max_seconds, :max_restarts, :strategy]
+    {sup_opts, start_opts} = Keyword.split(options, keys)
+    start_link(Supervisor.Default, init(sup_opts), start_opts)
+  end
+
+  @doc """
+  Starts a module-based supervisor process with the given `module` and `arg`.
+
+  To start the supervisor, the `c:init/1` callback will be invoked in the given
+  `module`, with `arg` as its argument. The `c:init/1` callback must return a
+  supervisor specification which can be created with the help of the `init/1`
+  function.
+
+  If the `c:init/1` callback returns `:ignore`, this function returns
+  `:ignore` as well and the supervisor terminates with reason `:normal`.
+  If it fails or returns an incorrect value, this function returns
+  `{:error, term}` where `term` is a term with information about the
+  error, and the supervisor terminates with reason `term`.
+
+  The `:name` option can also be given in order to register a supervisor
+  name, the supported values are described in the "Name registration"
+  section in the `GenServer` module docs.
+  """
+  @doc since: "1.6.0"
   @spec start_link(module, term, [option]) :: Supervisor.on_start()
-  def start_link(module, init_arg, opts \\ []) do
-    GenServer.start_link(__MODULE__, {module, init_arg, opts[:name]}, opts)
+  def start_link(mod, init_arg, opts \\ []) do
+    GenServer.start_link(__MODULE__, {mod, init_arg, opts[:name]}, opts)
   end
 
   @doc """
@@ -363,9 +287,7 @@ defmodule DynamicSupervisor do
 
   `child_spec` should be a valid child specification as detailed in the
   "Child specification" section of the documentation for `Supervisor`. The child
-  process will be started as defined in the child specification. Note that while
-  the `:id` field is still required in the spec, the value is ignored and
-  therefore does not need to be unique.
+  process will be started as defined in the child specification.
 
   If the child process start function returns `{:ok, child}` or `{:ok, child,
   info}`, then child specification and PID are added to the supervisor and
@@ -554,20 +476,46 @@ defmodule DynamicSupervisor do
   module-based supervisors. See the "Module-based supervisors" section
   in the module documentation for more information.
 
-  It accepts the same `options` as `start_link/1` (except for `:name`)
-  and it returns a tuple containing the supervisor options.
+  The `options` received by this function are also supported by `start_link/1`.
+
+  This function returns a tuple containing the supervisor options.
 
   ## Examples
 
       def init(_arg) do
-        DynamicSupervisor.init(max_children: 1000)
+        DynamicSupervisor.init(max_children: 1000, strategy: :one_for_one)
       end
 
+  ## Options
+
+    * `:strategy` - the restart strategy option. The only supported
+      value is `:one_for_one` which means that no other child is
+      terminated if a child process terminates. You can learn more
+      about strategies in the `Supervisor` module docs.
+
+    * `:max_restarts` - the maximum number of restarts allowed in
+      a time frame. Defaults to `3`.
+
+    * `:max_seconds` - the time frame in which `:max_restarts` applies.
+      Defaults to `5`.
+
+    * `:max_children` - the maximum amount of children to be running
+      under this supervisor at the same time. When `:max_children` is
+      exceeded, `start_child/2` returns `{:error, :max_children}`. Defaults
+      to `:infinity`.
+
+    * `:extra_arguments` - arguments that are prepended to the arguments
+      specified in the child spec given to `start_child/2`. Defaults to
+      an empty list.
+
   """
   @doc since: "1.6.0"
   @spec init([init_option]) :: {:ok, sup_flags()}
   def init(options) when is_list(options) do
-    strategy = Keyword.get(options, :strategy, :one_for_one)
+    unless strategy = options[:strategy] do
+      raise ArgumentError, "expected :strategy option to be given"
+    end
+
     intensity = Keyword.get(options, :max_restarts, 3)
     period = Keyword.get(options, :max_seconds, 5)
     max_children = Keyword.get(options, :max_children, :infinity)

lib/elixir/lib/exception.ex

@@ -43,16 +43,10 @@ defmodule Exception do
   @callback blame(t, stacktrace) :: {t, stacktrace}
   @optional_callbacks [blame: 2]
 
-  @doc false
-  # Callback for formatting Erlang exceptions
-  def format_error(%struct{} = exception, _stacktrace) do
-    %{general: message(exception), reason: "#" <> Atom.to_string(struct)}
-  end
-
   @doc """
   Returns `true` if the given `term` is an exception.
   """
-  # TODO: Deprecate this on Elixir v1.15
+  # TODO: Remove this on Elixir v1.15
   @doc deprecated: "Use Kernel.is_exception/1 instead"
   def exception?(term)
   def exception?(%_{__exception__: true}), do: true
@@ -68,7 +62,7 @@ defmodule Exception do
       caught_exception ->
         "got #{inspect(caught_exception.__struct__)} with message " <>
           "#{inspect(message(caught_exception))} while retrieving Exception.message/1 " <>
-          "for #{inspect(exception)}. Stacktrace:\n#{format_stacktrace(__STACKTRACE__)}"
+          "for #{inspect(exception)}"
     else
       result when is_binary(result) ->
         result
@@ -217,21 +211,16 @@ defmodule Exception do
       clauses =
         for {meta, ex_args, guards, _block} <- clauses do
           scope = :elixir_erl.scope(meta, true)
-          ann = :elixir_erl.get_ann(meta)
 
           {erl_args, scope} =
-            :elixir_erl_clauses.match(ann, &:elixir_erl_pass.translate_args/3, ex_args, scope)
+            :elixir_erl_clauses.match(&:elixir_erl_pass.translate_args/2, ex_args, scope)
 
           {args, binding} =
             [call_args, ex_args, erl_args]
             |> Enum.zip()
             |> Enum.map_reduce([], &blame_arg/2)
 
-          guards =
-            guards
-            |> Enum.map(&blame_guard(&1, ann, scope, binding))
-            |> Enum.map(&Macro.prewalk(&1, fn guard -> translate_guard(guard) end))
-
+          guards = Enum.map(guards, &blame_guard(&1, scope, binding))
           {args, guards}
         end
 
@@ -241,71 +230,6 @@ defmodule Exception do
     end
   end
 
-  defp is_map_node?({:is_map, _, [_]}), do: true
-  defp is_map_node?(_), do: false
-  defp is_map_key_node?({:is_map_key, _, [_, _]}), do: true
-  defp is_map_key_node?(_), do: false
-
-  defp struct_validation_node?(
-         {:is_atom, _, [{{:., [], [:erlang, :map_get]}, _, [:__struct__, _]}]}
-       ),
-       do: true
-
-  defp struct_validation_node?(
-         {:==, _, [{{:., [], [:erlang, :map_get]}, _, [:__struct__, _]}, _module]}
-       ),
-       do: true
-
-  defp struct_validation_node?(_), do: false
-
-  defp is_struct_macro?(
-         {:and, _,
-          [
-            {:and, _, [%{node: node_1 = {_, _, [arg]}}, %{node: node_2 = {_, _, [arg, _]}}]},
-            %{node: node_3 = {_, _, [{_, _, [_, arg]}]}}
-          ]}
-       ),
-       do: is_map_node?(node_1) and is_map_key_node?(node_2) and struct_validation_node?(node_3)
-
-  defp is_struct_macro?(
-         {:and, _,
-          [
-            {:and, _,
-             [
-               {:and, _,
-                [
-                  %{node: node_1 = {_, _, [arg]}},
-                  {:or, _, [%{node: {:is_atom, _, [_]}}, %{node: :fail}]}
-                ]},
-               %{node: node_2 = {_, _, [arg, _]}}
-             ]},
-            %{node: node_3 = {_, _, [{_, _, [_, arg]}, _]}}
-          ]}
-       ),
-       do: is_map_node?(node_1) and is_map_key_node?(node_2) and struct_validation_node?(node_3)
-
-  defp is_struct_macro?(_), do: false
-
-  defp translate_guard(guard) do
-    if is_struct_macro?(guard) do
-      undo_is_struct_guard(guard)
-    else
-      guard
-    end
-  end
-
-  defp undo_is_struct_guard(
-         {:and, meta, [_, %{node: {_, _, [{_, _, [_, {struct, _, _}]} | optional]}}]}
-       ) do
-    args =
-      case optional do
-        [] -> [{struct, meta, nil}]
-        [module] -> [{struct, meta, nil}, module]
-      end
-
-    %{match?: meta[:value], node: {:is_struct, meta, args}}
-  end
-
   defp blame_arg({call_arg, ex_arg, erl_arg}, binding) do
     {match?, binding} = blame_arg(erl_arg, call_arg, binding)
     {blame_wrap(match?, rewrite_arg(ex_arg)), binding}
@@ -336,11 +260,11 @@ defmodule Exception do
     end)
   end
 
-  defp blame_guard({{:., _, [:erlang, op]}, meta, [left, right]}, ann, scope, binding)
+  defp blame_guard({{:., _, [:erlang, op]}, meta, [left, right]}, scope, binding)
        when op == :andalso or op == :orelse do
     guards = [
-      blame_guard(left, ann, scope, binding),
-      blame_guard(right, ann, scope, binding)
+      blame_guard(left, scope, binding),
+      blame_guard(right, scope, binding)
     ]
 
     kernel_op =
@@ -349,38 +273,23 @@ defmodule Exception do
         :andalso -> :and
       end
 
-    evaluate_guard(kernel_op, meta, guards)
+    {kernel_op, meta, guards}
   end
 
-  defp blame_guard(ex_guard, ann, scope, binding) do
-    ex_guard
-    |> blame_guard?(binding, ann, scope)
-    |> blame_wrap(rewrite_guard(ex_guard))
-  end
+  defp blame_guard(ex_guard, scope, binding) do
+    {erl_guard, _} = :elixir_erl_pass.translate(ex_guard, scope)
 
-  defp blame_guard?(ex_guard, binding, ann, scope) do
-    {erl_guard, _} = :elixir_erl_pass.translate(ex_guard, ann, scope)
-    {:value, true, _} = :erl_eval.expr(erl_guard, binding, :none)
-    true
-  rescue
-    _ -> false
-  end
-
-  defp evaluate_guard(kernel_op, meta, guards = [_, _]) do
-    [x, y] = Enum.map(guards, &evaluate_guard/1)
-
-    logic_value =
-      case kernel_op do
-        :or -> x or y
-        :and -> x and y
+    match? =
+      try do
+        {:value, true, _} = :erl_eval.expr(erl_guard, binding, :none)
+        true
+      rescue
+        _ -> false
       end
 
-    {kernel_op, Keyword.put(meta, :value, logic_value), guards}
+    blame_wrap(match?, rewrite_guard(ex_guard))
   end
 
-  defp evaluate_guard(%{match?: value}), do: value
-  defp evaluate_guard({_, meta, _}) when is_list(meta), do: meta[:value]
-
   defp rewrite_guard(guard) do
     Macro.prewalk(guard, fn
       {{:., _, [mod, fun]}, meta, args} -> erl_to_ex(mod, fun, args, meta)
@@ -706,12 +615,12 @@ defmodule Exception do
     case Code.Identifier.extract_anonymous_fun_parent(fun) do
       {outer_name, outer_arity} ->
         "anonymous fn#{format_arity(arity)} in " <>
-          "#{Macro.inspect_atom(:literal, module)}." <>
-          "#{Macro.inspect_atom(:remote_call, outer_name)}/#{outer_arity}"
+          "#{Code.Identifier.inspect_as_atom(module)}." <>
+          "#{Code.Identifier.inspect_as_function(outer_name)}/#{outer_arity}"
 
       :error ->
-        "#{Macro.inspect_atom(:literal, module)}." <>
-          "#{Macro.inspect_atom(:remote_call, fun)}#{format_arity(arity)}"
+        "#{Code.Identifier.inspect_as_atom(module)}." <>
+          "#{Code.Identifier.inspect_as_function(fun)}#{format_arity(arity)}"
     end
   end
 
@@ -781,17 +690,6 @@ defmodule Exception do
     end
   end
 
-  @doc false
-  def format_snippet(snippet, error_line) do
-    line_digits = error_line |> Integer.to_string() |> byte_size()
-    placeholder = String.duplicate(" ", max(line_digits, 2))
-    padding = if line_digits < 2, do: " "
-
-    " #{placeholder} |\n" <>
-      " #{padding}#{error_line} | #{snippet.content}\n" <>
-      " #{placeholder} | #{String.duplicate(" ", snippet.offset)}^"
-  end
-
   defp format_location(opts) when is_list(opts) do
     format_file_line(Keyword.get(opts, :file), Keyword.get(opts, :line), " ")
   end
@@ -816,25 +714,24 @@ defmodule ArgumentError do
       ) do
     message =
       cond do
-        not proper_list?(args) ->
-          "you attempted to apply a function named #{inspect(function)} on module #{inspect(module)} " <>
-            "with arguments #{inspect(args)}. Arguments (the third argument of apply) must always be a proper list"
-
         # Note that args may be an empty list even if they were supplied
         not is_atom(module) and is_atom(function) and args == [] ->
-          "you attempted to apply a function named #{inspect(function)} on #{inspect(module)}. " <>
-            "If you are using Kernel.apply/3, make sure the module is an atom. " <>
-            "If you are using the dot syntax, such as module.function(), " <>
-            "make sure the left-hand side of the dot is a module atom"
+          "you attempted to apply #{inspect(function)} on #{inspect(module)}. " <>
+            "If you are using apply/3, make sure the module is an atom. " <>
+            "If you are using the dot syntax, such as map.field or module.function(), " <>
+            "make sure the left side of the dot is an atom or a map"
 
         not is_atom(module) ->
           "you attempted to apply a function on #{inspect(module)}. " <>
             "Modules (the first argument of apply) must always be an atom"
 
         not is_atom(function) ->
-          "you attempted to apply a function named #{inspect(function)} on module #{inspect(module)}. " <>
-            "However #{inspect(function)} is not a valid function name. Function names (the second argument " <>
-            "of apply) must always be an atom"
+          "you attempted to apply #{inspect(function)} on module #{inspect(module)}. " <>
+            "Functions (the second argument of apply) must always be an atom"
+
+        not is_list(args) ->
+          "you attempted to apply #{inspect(function)} on module #{inspect(module)} " <>
+            "with arguments #{inspect(args)}. Arguments (the third argument of apply) must always be a list"
       end
 
     {%{exception | message: message}, stacktrace}
@@ -843,9 +740,6 @@ defmodule ArgumentError do
   def blame(exception, stacktrace) do
     {exception, stacktrace}
   end
-
-  defp proper_list?(list) when length(list) >= 0, do: true
-  defp proper_list?(_), do: false
 end
 
 defmodule ArithmeticError do
@@ -893,56 +787,20 @@ defmodule SystemLimitError do
 end
 
 defmodule SyntaxError do
-  defexception [:file, :line, :column, :snippet, description: "syntax error"]
+  defexception [:file, :line, :column, description: "syntax error"]
 
   @impl true
-  def message(%{
-        file: file,
-        line: line,
-        column: column,
-        description: description,
-        snippet: snippet
-      })
-      when not is_nil(snippet) and not is_nil(column) do
-    Exception.format_file_line_column(Path.relative_to_cwd(file), line, column) <>
-      " " <> description <> "\n" <> Exception.format_snippet(snippet, line)
-  end
-
-  @impl true
-  def message(%{
-        file: file,
-        line: line,
-        column: column,
-        description: description
-      }) do
+  def message(%{file: file, line: line, column: column, description: description}) do
     Exception.format_file_line_column(Path.relative_to_cwd(file), line, column) <>
       " " <> description
   end
 end
 
 defmodule TokenMissingError do
-  defexception [:file, :line, :snippet, :column, description: "expression is incomplete"]
+  defexception [:file, :line, :column, description: "expression is incomplete"]
 
   @impl true
-  def message(%{
-        file: file,
-        line: line,
-        column: column,
-        description: description,
-        snippet: snippet
-      })
-      when not is_nil(snippet) and not is_nil(column) do
-    Exception.format_file_line_column(Path.relative_to_cwd(file), line, column) <>
-      " " <> description <> "\n" <> Exception.format_snippet(snippet, line)
-  end
-
-  @impl true
-  def message(%{
-        file: file,
-        line: line,
-        column: column,
-        description: description
-      }) do
+  def message(%{file: file, line: line, column: column, description: description}) do
     Exception.format_file_line_column(file && Path.relative_to_cwd(file), line, column) <>
       " " <> description
   end
@@ -1114,8 +972,8 @@ defmodule UndefinedFunctionError do
   end
 
   defp hint(nil, _function, 0, _loaded?) do
-    ". If you are using the dot syntax, such as module.function(), " <>
-      "make sure the left-hand side of the dot is a module atom"
+    ". If you are using the dot syntax, such as map.field or module.function(), " <>
+      "make sure the left side of the dot is an atom or a map"
   end
 
   defp hint(module, function, arity, true) do
@@ -1175,12 +1033,12 @@ defmodule UndefinedFunctionError do
 
     case result do
       [] -> []
-      suggestions -> [". Did you mean:\n\n" | Enum.map(suggestions, &format_fa/1)]
+      suggestions -> [". Did you mean one of:\n\n" | Enum.map(suggestions, &format_fa/1)]
     end
   end
 
   defp format_fa({_dist, fun, arity}) do
-    ["      * ", Macro.inspect_atom(:remote_call, fun), ?/, Integer.to_string(arity), ?\n]
+    ["      * ", Code.Identifier.inspect_as_function(fun), ?/, Integer.to_string(arity), ?\n]
   end
 
   defp behaviour_hint(module, function, arity) do
@@ -1206,9 +1064,7 @@ defmodule UndefinedFunctionError do
   end
 
   defp expects_callback?(behaviour, function, arity) do
-    callbacks =
-      behaviour.behaviour_info(:callbacks) -- behaviour.behaviour_info(:optional_callbacks)
-
+    callbacks = behaviour.behaviour_info(:callbacks)
     Enum.member?(callbacks, {function, arity})
   end
 
@@ -1250,7 +1106,7 @@ defmodule FunctionClauseError do
 
       %{module: module, function: function, arity: arity} ->
         formatted = Exception.format_mfa(module, function, arity)
-        blamed = blame(exception, &inspect/1, &blame_match/1)
+        blamed = blame(exception, &inspect/1, &blame_match/2)
         "no function clause matching in #{formatted}" <> blamed
     end
   end
@@ -1272,24 +1128,24 @@ defmodule FunctionClauseError do
     end
   end
 
-  defp blame_match(%{match?: true, node: node}), do: Macro.to_string(node)
-  defp blame_match(%{match?: false, node: node}), do: "-" <> Macro.to_string(node) <> "-"
+  defp blame_match(%{match?: true, node: node}, _), do: Macro.to_string(node)
+  defp blame_match(%{match?: false, node: node}, _), do: "-" <> Macro.to_string(node) <> "-"
+  defp blame_match(_, string), do: string
 
   @doc false
   def blame(%{args: nil}, _, _) do
     ""
   end
 
-  def blame(exception, inspect_fun, fun) do
+  def blame(exception, inspect_fun, ast_fun) do
     %{module: module, function: function, arity: arity, kind: kind, args: args, clauses: clauses} =
       exception
 
     mfa = Exception.format_mfa(module, function, arity)
 
     format_clause_fun = fn {args, guards} ->
-      args = Enum.map_join(args, ", ", fun)
-      base = "    #{kind} #{function}(#{args})"
-      Enum.reduce(guards, base, &"#{&2} when #{clause_to_string(&1, fun)}") <> "\n"
+      code = Enum.reduce(guards, {function, [], args}, &{:when, [], [&2, &1]})
+      "    #{kind} " <> Macro.to_string(code, ast_fun) <> "\n"
     end
 
     "\n\nThe following arguments were given to #{mfa}:\n" <>
@@ -1297,11 +1153,6 @@ defmodule FunctionClauseError do
       "#{format_clauses(clauses, format_clause_fun, @clause_limit)}"
   end
 
-  defp clause_to_string({op, _, [left, right]}, fun),
-    do: clause_to_string(left, fun) <> " #{op} " <> clause_to_string(right, fun)
-
-  defp clause_to_string(node, fun), do: fun.(node)
-
   defp format_args(args, inspect_fun) do
     args
     |> Enum.with_index(1)
@@ -1338,13 +1189,11 @@ defmodule FunctionClauseError do
 end
 
 defmodule Code.LoadError do
-  defexception [:file, :message, :reason]
+  defexception [:file, :message]
 
   def exception(opts) do
     file = Keyword.fetch!(opts, :file)
-    reason = Keyword.fetch!(opts, :reason)
-    message = "could not load #{file}. Reason: #{reason}"
-    %Code.LoadError{message: message, file: file, reason: reason}
+    %Code.LoadError{message: "could not load #{file}", file: file}
   end
 end
 
@@ -1448,7 +1297,7 @@ defmodule KeyError do
 
     case suggestions do
       [] -> []
-      suggestions -> [". Did you mean:\n\n" | format_suggestions(suggestions)]
+      suggestions -> [". Did you mean one of:\n\n" | format_suggestions(suggestions)]
     end
   end
 
@@ -1559,24 +1408,22 @@ defmodule File.LinkError do
 end
 
 defmodule ErlangError do
-  defexception [:original, :reason]
+  defexception [:original]
 
   @impl true
-  def message(exception)
-
-  def message(%__MODULE__{original: original, reason: nil}) do
-    "Erlang error: #{inspect(original)}"
-  end
-
-  def message(%__MODULE__{original: original, reason: reason}) do
-    IO.iodata_to_binary(["Erlang error: ", inspect(original), reason])
+  def message(exception) do
+    "Erlang error: #{inspect(exception.original)}"
   end
 
   @doc false
   def normalize(:badarg, stacktrace) do
-    case error_info(:badarg, stacktrace, "errors were found at the given arguments") do
-      {:ok, reason, details} -> %ArgumentError{message: reason <> details}
-      :error -> %ArgumentError{}
+    case error_info(:badarg, stacktrace) do
+      {:ok, args} ->
+        message = "errors were found at the given arguments:\n\n#{args}"
+        %ArgumentError{message: message}
+
+      :error ->
+        %ArgumentError{}
     end
   end
 
@@ -1585,11 +1432,15 @@ defmodule ErlangError do
   end
 
   def normalize(:system_limit, stacktrace) do
-    default_reason = "a system limit has been reached due to errors at the given arguments"
+    case error_info(:system_limit, stacktrace) do
+      {:ok, args} ->
+        message =
+          "a system limit has been reached due to errors at the given arguments:\n\n#{args}"
 
-    case error_info(:system_limit, stacktrace, default_reason) do
-      {:ok, reason, details} -> %SystemLimitError{message: reason <> details}
-      :error -> %SystemLimitError{}
+        %SystemLimitError{message: message}
+
+      :error ->
+        %SystemLimitError{}
     end
   end
 
@@ -1635,19 +1486,10 @@ defmodule ErlangError do
     %KeyError{key: key, term: term}
   end
 
-  def normalize({:badkey, key, map}, _stacktrace) when is_map(map) do
+  def normalize({:badkey, key, map}, _stacktrace) do
     %KeyError{key: key, term: map}
   end
 
-  def normalize({:badkey, key, term}, _stacktrace) do
-    message =
-      "key #{inspect(key)} not found in: #{inspect(term)}. " <>
-        "If you are using the dot syntax, such as map.field, " <>
-        "make sure the left-hand side of the dot is a map"
-
-    %KeyError{key: key, term: term, message: message}
-  end
-
   def normalize({:case_clause, term}, _stacktrace) do
     %CaseClauseError{term: term}
   end
@@ -1674,11 +1516,8 @@ defmodule ErlangError do
     %ArgumentError{message: "argument error: #{inspect(payload)}"}
   end
 
-  def normalize(other, stacktrace) do
-    case error_info(other, stacktrace, "") do
-      {:ok, _reason, details} -> %ErlangError{original: other, reason: details}
-      :error -> %ErlangError{original: other}
-    end
+  def normalize(other, _stacktrace) do
+    %ErlangError{original: other}
   end
 
   defp from_stacktrace([{module, function, args, _} | _]) when is_list(args) do
@@ -1693,35 +1532,20 @@ defmodule ErlangError do
     {nil, nil, nil}
   end
 
-  defp error_info(erl_exception, stacktrace, default_reason) do
-    with [{module, fun, args_or_arity, opts} | tail] <- stacktrace,
+  @doc false
+  def error_info(erl_exception, stacktrace) do
+    with [{module, _, args_or_arity, opts} | _] <- stacktrace,
          %{} = error_info <- opts[:error_info] do
-      error_module = Map.get(error_info, :module, module)
-      error_fun = Map.get(error_info, :function, :format_error)
-
-      error_info = Map.put(error_info, :pretty_printer, &inspect/1)
-      head = {module, fun, args_or_arity, Keyword.put(opts, :error_info, error_info)}
-
-      extra =
-        try do
-          apply(error_module, error_fun, [erl_exception, [head | tail]])
-        rescue
-          _ -> %{}
-        end
-
+      module = Map.get(error_info, :module, module)
+      function = Map.get(error_info, :function, :format_error)
       arity = if is_integer(args_or_arity), do: args_or_arity, else: length(args_or_arity)
+      extra = apply(module, function, [erl_exception, stacktrace])
       args_errors = Map.take(extra, Enum.to_list(1..arity//1))
-      reason = Map.get(extra, :reason, default_reason)
 
-      cond do
-        map_size(args_errors) > 0 ->
-          {:ok, reason, IO.iodata_to_binary([":\n\n" | Enum.map(args_errors, &arg_error/1)])}
-
-        general = extra[:general] ->
-          {:ok, reason, ": " <> general}
-
-        true ->
-          :error
+      if map_size(args_errors) > 0 do
+        {:ok, IO.iodata_to_binary(Enum.map(args_errors, &arg_error/1))}
+      else
+        :error
       end
     else
       _ -> :error
@@ -1735,61 +1559,3 @@ defmodule ErlangError do
   defp nth(3), do: "3rd"
   defp nth(n), do: "#{n}th"
 end
-
-defmodule Inspect.Error do
-  @moduledoc """
-  Raised when a struct cannot be inspected.
-  """
-  @enforce_keys [:exception_module, :exception_message, :stacktrace, :inspected_struct]
-  defexception @enforce_keys
-
-  @impl true
-  def exception(arguments) when is_list(arguments) do
-    exception = Keyword.fetch!(arguments, :exception)
-    exception_module = exception.__struct__
-    exception_message = Exception.message(exception) |> String.trim_trailing("\n")
-    stacktrace = Keyword.fetch!(arguments, :stacktrace)
-    inspected_struct = Keyword.fetch!(arguments, :inspected_struct)
-
-    %Inspect.Error{
-      exception_module: exception_module,
-      exception_message: exception_message,
-      stacktrace: stacktrace,
-      inspected_struct: inspected_struct
-    }
-  end
-
-  @impl true
-  def message(%__MODULE__{
-        exception_module: exception_module,
-        exception_message: exception_message,
-        inspected_struct: inspected_struct
-      }) do
-    ~s'''
-    got #{inspect(exception_module)} with message:
-
-        """
-    #{pad(exception_message, 4)}
-        """
-
-    while inspecting:
-
-    #{pad(inspected_struct, 4)}
-    '''
-  end
-
-  @doc false
-  def pad(message, padding_length)
-      when is_binary(message) and is_integer(padding_length) and padding_length >= 0 do
-    padding = String.duplicate(" ", padding_length)
-
-    message
-    |> String.split("\n")
-    |> Enum.map(fn
-      "" -> "\n"
-      line -> [padding, line, ?\n]
-    end)
-    |> IO.iodata_to_binary()
-    |> String.trim_trailing("\n")
-  end
-end

lib/elixir/lib/file.ex

@@ -112,7 +112,6 @@ defmodule File do
           encoding_mode()
           | :append
           | :compressed
-          | :delayed_write
           | :trim_bom
           | {:read_ahead, pos_integer | false}
           | {:delayed_write, non_neg_integer, non_neg_integer}
@@ -123,8 +122,6 @@ defmodule File do
 
   @type posix_time :: integer()
 
-  @type on_conflict_callback :: (Path.t(), Path.t() -> boolean)
-
   @doc """
   Returns `true` if the path is a regular file.
 
@@ -696,10 +693,7 @@ defmodule File do
   @spec copy(Path.t() | io_device, Path.t() | io_device, pos_integer | :infinity) ::
           {:ok, non_neg_integer} | {:error, posix}
   def copy(source, destination, bytes_count \\ :infinity) do
-    source = normalize_path_or_io_device(source)
-    destination = normalize_path_or_io_device(destination)
-
-    :file.copy(source, destination, bytes_count)
+    :file.copy(maybe_to_string(source), maybe_to_string(destination), bytes_count)
   end
 
   @doc """
@@ -717,8 +711,8 @@ defmodule File do
         raise File.CopyError,
           reason: reason,
           action: "copy",
-          source: normalize_path_or_io_device(source),
-          destination: normalize_path_or_io_device(destination)
+          source: maybe_to_string(source),
+          destination: maybe_to_string(destination)
     end
   end
 
@@ -746,8 +740,6 @@ defmodule File do
   @doc since: "1.1.0"
   @spec rename(Path.t(), Path.t()) :: :ok | {:error, posix}
   def rename(source, destination) do
-    source = IO.chardata_to_string(source)
-    destination = IO.chardata_to_string(destination)
     :file.rename(source, destination)
   end
 
@@ -778,6 +770,11 @@ defmodule File do
   be a path to a non-existent file. If either is a directory, `{:error, :eisdir}`
   will be returned.
 
+  The `callback` function is invoked if the `destination_file` already exists.
+  The function receives arguments for `source_file` and `destination_file`;
+  it should return `true` if the existing file should be overwritten, `false` if
+  otherwise. The default callback returns `true`.
+
   The function returns `:ok` in case of success. Otherwise, it returns
   `{:error, reason}`.
 
@@ -789,30 +786,13 @@ defmodule File do
   whether the destination is an existing directory or not. We have chosen to
   explicitly disallow copying to a destination which is a directory,
   and an error will be returned if tried.
-
-  ## Options
-
-    * `:on_conflict` - (since v1.14.0) Invoked when a file already exists in the destination.
-      The function receives arguments for `source_file` and `destination_file`. It should
-      return `true` if the existing file should be overwritten, `false` if otherwise.
-      The default callback returns `true`. On earlier versions, this callback could be
-      given as third argument, but such behaviour is now deprecated.
-
   """
-  @spec cp(Path.t(), Path.t(), on_conflict: on_conflict_callback) :: :ok | {:error, posix}
-  def cp(source_file, destination_file, options \\ [])
-
-  # TODO: Deprecate me on Elixir v1.19
-  def cp(source_file, destination_file, callback) when is_function(callback, 2) do
-    cp(source_file, destination_file, on_conflict: callback)
-  end
-
-  def cp(source_file, destination_file, options) when is_list(options) do
-    on_conflict = Keyword.get(options, :on_conflict, fn _, _ -> true end)
+  @spec cp(Path.t(), Path.t(), (Path.t(), Path.t() -> boolean)) :: :ok | {:error, posix}
+  def cp(source_file, destination_file, callback \\ fn _, _ -> true end) do
     source_file = IO.chardata_to_string(source_file)
     destination_file = IO.chardata_to_string(destination_file)
 
-    case do_cp_file(source_file, destination_file, on_conflict, []) do
+    case do_cp_file(source_file, destination_file, callback, []) do
       {:error, reason, _} -> {:error, reason}
       _ -> :ok
     end
@@ -828,9 +808,9 @@ defmodule File do
   The same as `cp/3`, but raises a `File.CopyError` exception if it fails.
   Returns `:ok` otherwise.
   """
-  @spec cp!(Path.t(), Path.t(), on_conflict: on_conflict_callback) :: :ok
-  def cp!(source_file, destination_file, options \\ []) do
-    case cp(source_file, destination_file, options) do
+  @spec cp!(Path.t(), Path.t(), (Path.t(), Path.t() -> boolean)) :: :ok
+  def cp!(source_file, destination_file, callback \\ fn _, _ -> true end) do
+    case cp(source_file, destination_file, callback) do
       :ok ->
         :ok
 
@@ -853,15 +833,18 @@ defmodule File do
   If `source` is a directory, or a symbolic link to it, then `destination` must
   be an existent `directory` or a symbolic link to one, or a path to a non-existent directory.
 
-  If the source is a file, it copies `source` to `destination`. If the `source`
-  is a directory, it copies the contents inside source into the `destination` directory.
+  If the source is a file, it copies `source` to
+  `destination`. If the `source` is a directory, it copies
+  the contents inside source into the `destination` directory.
 
-  If a file already exists in the destination, it invokes the optional `on_conflict`
-  callback given as an option. See "Options" for more information.
+  If a file already exists in the destination, it invokes `callback`.
+  `callback` must be a function that takes two arguments: `source` and `destination`.
+  The callback should return `true` if the existing file should be overwritten and `false` otherwise.
 
-  This function may fail while copying files, in such cases, it will leave the
-  destination directory in a dirty state, where file which have already been
-  copied won't be removed.
+  This function may fail while copying files,
+  in such cases, it will leave the destination
+  directory in a dirty state, where file which have already been copied
+  won't be removed.
 
   The function returns `{:ok, files_and_directories}` in case of
   success, `files_and_directories` lists all files and directories copied in no
@@ -872,19 +855,6 @@ defmodule File do
   explicitly disallow this behaviour. If `source` is a `file` and `destination`
   is a directory, `{:error, :eisdir}` will be returned.
 
-  ## Options
-
-    * `:on_conflict` - (since v1.14.0) Invoked when a file already exists in the destination.
-      The function receives arguments for `source` and `destination`. It should return
-      `true` if the existing file should be overwritten, `false` if otherwise. The default
-      callback returns `true`. On earlier versions, this callback could be given as third
-      argument, but such behaviour is now deprecated.
-
-    * `:dereference_symlinks` - (since v1.14.0) By default, this function will copy symlinks
-      by creating symlinks that point to the same location. This option forces symlinks to be
-      dereferenced and have their contents copied instead when set to `true`. If the dereferenced
-      files do not exist, than the operation fails. The default is `false`.
-
   ## Examples
 
       # Copies file "a.txt" to "b.txt"
@@ -894,28 +864,14 @@ defmodule File do
       File.cp_r("samples", "tmp")
 
       # Same as before, but asks the user how to proceed in case of conflicts
-      File.cp_r("samples", "tmp", on_conflict: fn source, destination ->
+      File.cp_r("samples", "tmp", fn source, destination ->
         IO.gets("Overwriting #{destination} by #{source}. Type y to confirm. ") == "y\n"
       end)
 
   """
-  @spec cp_r(Path.t(), Path.t(),
-          on_conflict: on_conflict_callback,
-          dereference_symlinks: boolean()
-        ) ::
+  @spec cp_r(Path.t(), Path.t(), (Path.t(), Path.t() -> boolean)) ::
           {:ok, [binary]} | {:error, posix, binary}
-
-  def cp_r(source, destination, options \\ [])
-
-  # TODO: Deprecate me on Elixir v1.19
-  def cp_r(source, destination, callback) when is_function(callback, 2) do
-    cp_r(source, destination, on_conflict: callback)
-  end
-
-  def cp_r(source, destination, options) when is_list(options) do
-    on_conflict = Keyword.get(options, :on_conflict, fn _, _ -> true end)
-    dereference? = Keyword.get(options, :dereference_symlinks, false)
-
+  def cp_r(source, destination, callback \\ fn _, _ -> true end) when is_function(callback, 2) do
     source =
       source
       |> IO.chardata_to_string()
@@ -926,7 +882,7 @@ defmodule File do
       |> IO.chardata_to_string()
       |> assert_no_null_byte!("File.cp_r/3")
 
-    case do_cp_r(source, destination, on_conflict, dereference?, []) do
+    case do_cp_r(source, destination, callback, []) do
       {:error, _, _} = error -> error
       res -> {:ok, res}
     end
@@ -936,12 +892,9 @@ defmodule File do
   The same as `cp_r/3`, but raises a `File.CopyError` exception if it fails.
   Returns the list of copied files otherwise.
   """
-  @spec cp_r!(Path.t(), Path.t(),
-          on_conflict: on_conflict_callback,
-          dereference_symlinks: boolean()
-        ) :: [binary]
-  def cp_r!(source, destination, options \\ []) do
-    case cp_r(source, destination, options) do
+  @spec cp_r!(Path.t(), Path.t(), (Path.t(), Path.t() -> boolean)) :: [binary]
+  def cp_r!(source, destination, callback \\ fn _, _ -> true end) do
+    case cp_r(source, destination, callback) do
       {:ok, files} ->
         files
 
@@ -955,21 +908,15 @@ defmodule File do
     end
   end
 
-  defp do_cp_r(src, dest, on_conflict, dereference?, acc) when is_list(acc) do
+  defp do_cp_r(src, dest, callback, acc) when is_list(acc) do
     case :elixir_utils.read_link_type(src) do
       {:ok, :regular} ->
-        do_cp_file(src, dest, on_conflict, acc)
+        do_cp_file(src, dest, callback, acc)
 
       {:ok, :symlink} ->
         case :file.read_link(src) do
-          {:ok, link} when dereference? ->
-            do_cp_r(Path.expand(link, Path.dirname(src)), dest, on_conflict, dereference?, acc)
-
-          {:ok, link} ->
-            do_cp_link(link, src, dest, on_conflict, acc)
-
-          {:error, reason} ->
-            {:error, reason, src}
+          {:ok, link} -> do_cp_link(link, src, dest, callback, acc)
+          {:error, reason} -> {:error, reason, src}
         end
 
       {:ok, :directory} ->
@@ -978,7 +925,7 @@ defmodule File do
             case mkdir(dest) do
               success when success in [:ok, {:error, :eexist}] ->
                 Enum.reduce(files, [dest | acc], fn x, acc ->
-                  do_cp_r(Path.join(src, x), Path.join(dest, x), on_conflict, dereference?, acc)
+                  do_cp_r(Path.join(src, x), Path.join(dest, x), callback, acc)
                 end)
 
               {:error, reason} ->
@@ -997,8 +944,9 @@ defmodule File do
     end
   end
 
-  # If we reach this clause, there was an error while processing a file.
-  defp do_cp_r(_, _, _, _, acc) do
+  # If we reach this clause, there was an error while
+  # processing a file.
+  defp do_cp_r(_, _, _, acc) do
     acc
   end
 
@@ -1007,14 +955,14 @@ defmodule File do
   end
 
   # Both src and dest are files.
-  defp do_cp_file(src, dest, on_conflict, acc) do
+  defp do_cp_file(src, dest, callback, acc) do
     case :file.copy(src, {dest, [:exclusive]}) do
       {:ok, _} ->
         copy_file_mode!(src, dest)
         [dest | acc]
 
       {:error, :eexist} ->
-        if path_differs?(src, dest) and on_conflict.(src, dest) do
+        if path_differs?(src, dest) and callback.(src, dest) do
           case copy(src, dest) do
             {:ok, _} ->
               copy_file_mode!(src, dest)
@@ -1033,13 +981,13 @@ defmodule File do
   end
 
   # Both src and dest are files.
-  defp do_cp_link(link, src, dest, on_conflict, acc) do
+  defp do_cp_link(link, src, dest, callback, acc) do
     case :file.make_symlink(link, dest) do
       :ok ->
         [dest | acc]
 
       {:error, :eexist} ->
-        if path_differs?(src, dest) and on_conflict.(src, dest) do
+        if path_differs?(src, dest) and callback.(src, dest) do
           # If rm/1 fails, :file.make_symlink/2 will fail
           _ = rm(dest)
 
@@ -1096,7 +1044,9 @@ defmodule File do
   """
   @spec write!(Path.t(), iodata, [mode]) :: :ok
   def write!(path, content, modes \\ []) do
-    case write(path, content, modes) do
+    modes = normalize_modes(modes, false)
+
+    case :file.write_file(path, content, modes) do
       :ok ->
         :ok
 
@@ -1244,79 +1194,82 @@ defmodule File do
   """
   @spec rm_rf(Path.t()) :: {:ok, [binary]} | {:error, posix, binary}
   def rm_rf(path) do
-    {major, _} = :os.type()
-
     path
     |> IO.chardata_to_string()
     |> assert_no_null_byte!("File.rm_rf/1")
-    |> do_rm_rf([], major)
+    |> do_rm_rf({:ok, []})
   end
 
-  defp do_rm_rf(path, acc, major) do
-    case safe_list_dir(path, major) do
+  defp do_rm_rf(path, {:ok, _} = entry) do
+    case safe_list_dir(path) do
       {:ok, files} when is_list(files) ->
-        acc =
-          Enum.reduce(files, acc, fn file, acc ->
-            # In case we can't delete, continue anyway, we might succeed
-            # to delete it on Windows due to how they handle symlinks.
-            case do_rm_rf(Path.join(path, file), acc, major) do
-              {:ok, acc} -> acc
-              {:error, _, _} -> acc
-            end
+        res =
+          Enum.reduce(files, entry, fn file, tuple ->
+            do_rm_rf(Path.join(path, file), tuple)
           end)
 
-        case rmdir(path) do
-          :ok -> {:ok, [path | acc]}
-          {:error, :enoent} -> {:ok, acc}
-          {:error, reason} -> {:error, reason, path}
+        case res do
+          {:ok, acc} ->
+            case rmdir(path) do
+              :ok -> {:ok, [path | acc]}
+              {:error, :enoent} -> res
+              {:error, reason} -> {:error, reason, path}
+            end
+
+          reason ->
+            reason
         end
 
       {:ok, :directory} ->
-        do_rm_directory(path, acc)
+        do_rm_directory(path, entry)
 
       {:ok, :regular} ->
-        do_rm_regular(path, acc)
+        do_rm_regular(path, entry)
 
       {:error, reason} when reason in [:enoent, :enotdir] ->
-        {:ok, acc}
+        entry
 
       {:error, reason} ->
         {:error, reason, path}
     end
   end
 
-  defp do_rm_regular(path, acc) do
+  defp do_rm_rf(_, reason) do
+    reason
+  end
+
+  defp do_rm_regular(path, {:ok, acc} = entry) do
     case rm(path) do
       :ok -> {:ok, [path | acc]}
-      {:error, :enoent} -> {:ok, acc}
+      {:error, :enoent} -> entry
       {:error, reason} -> {:error, reason, path}
     end
   end
 
   # On Windows, symlinks are treated as directory and must be removed
-  # with rmdir/1. But on Unix-like systems, we remove them via rm/1.
-  # So we first try to remove it as a directory and, if we get :enotdir,
-  # we fall back to a file removal.
-  defp do_rm_directory(path, acc) do
+  # with rmdir/1. But on Unix-like systems, we remove them via rm/1. So we first try
+  # to remove it as a directory and, if we get :enotdir, we fall back to
+  # a file removal.
+  defp do_rm_directory(path, {:ok, acc} = entry) do
     case rmdir(path) do
       :ok -> {:ok, [path | acc]}
-      {:error, :enotdir} -> do_rm_regular(path, acc)
-      {:error, :enoent} -> {:ok, acc}
+      {:error, :enotdir} -> do_rm_regular(path, entry)
+      {:error, :enoent} -> entry
       {:error, reason} -> {:error, reason, path}
     end
   end
 
-  defp safe_list_dir(path, major) do
+  defp safe_list_dir(path) do
     case :elixir_utils.read_link_type(path) do
-      {:ok, :directory} ->
-        :file.list_dir_all(path)
-
-      {:ok, :symlink} when major == :win32 ->
+      {:ok, :symlink} ->
         case :elixir_utils.read_file_type(path) do
           {:ok, :directory} -> {:ok, :directory}
           _ -> {:ok, :regular}
         end
 
+      {:ok, :directory} ->
+        :file.list_dir(path)
+
       {:ok, _} ->
         {:ok, :regular}
 
@@ -1654,7 +1607,7 @@ defmodule File do
     :file.close(io_device)
   end
 
-  @doc ~S"""
+  @doc """
   Returns a `File.Stream` for the given `path` with the given `modes`.
 
   The stream implements both `Enumerable` and `Collectable` protocols,
@@ -1852,8 +1805,7 @@ defmodule File do
   defp normalize_modes([], true), do: [:binary]
   defp normalize_modes([], false), do: []
 
-  defp normalize_path_or_io_device(path) when is_list(path), do: IO.chardata_to_string(path)
-  defp normalize_path_or_io_device(path) when is_binary(path), do: path
-  defp normalize_path_or_io_device(io_device) when is_pid(io_device), do: io_device
-  defp normalize_path_or_io_device(io_device = {:file_descriptor, _, _}), do: io_device
+  defp maybe_to_string(path) when is_list(path), do: IO.chardata_to_string(path)
+  defp maybe_to_string(path) when is_binary(path), do: path
+  defp maybe_to_string(path), do: path
 end

lib/elixir/lib/float.ex

@@ -15,7 +15,7 @@ defmodule Float do
   ## Known issues
 
   There are some very well known problems with floating-point numbers
-  and arithmetic due to the fact most decimal fractions cannot be
+  and arithmetics due to the fact most decimal fractions cannot be
   represented by a floating-point binary and most operations are not exact,
   but operate on approximations. Those issues are not specific
   to Elixir, they are a property of floating point representation itself.
@@ -46,31 +46,6 @@ defmodule Float do
   @precision_range 0..15
   @type precision_range :: 0..15
 
-  @min_finite then(<<0xFFEFFFFFFFFFFFFF::64>>, fn <<num::float>> -> num end)
-  @max_finite then(<<0x7FEFFFFFFFFFFFFF::64>>, fn <<num::float>> -> num end)
-
-  @doc """
-  Returns the maximum finite value for a float.
-
-  ## Examples
-
-      iex> Float.max_finite()
-      1.7976931348623157e308
-
-  """
-  def max_finite, do: @max_finite
-
-  @doc """
-  Returns the minimum finite value for a float.
-
-  ## Examples
-
-      iex> Float.min_finite()
-      -1.7976931348623157e308
-
-  """
-  def min_finite, do: @min_finite
-
   @doc """
   Computes `base` raised to power of `exponent`.
 
@@ -119,8 +94,7 @@ defmodule Float do
   returned.
 
   If the size of float exceeds the maximum size of `1.7976931348623157e+308`,
-  `:error` is returned even though the textual representation itself might be
-  well formed.
+  the `ArgumentError` exception is raised.
 
   If you want to convert a string-formatted float directly to a float,
   `String.to_float/1` can be used instead.
@@ -136,8 +110,6 @@ defmodule Float do
 
       iex> Float.parse("pi")
       :error
-      iex> Float.parse("1.7976931348623159e+308")
-      :error
 
   """
   @spec parse(binary) :: {float, binary} | :error
@@ -175,18 +147,7 @@ defmodule Float do
        when exp_marker in 'eE' and sign in '-+' and digit in ?0..?9,
        do: parse_unsigned(rest, true, true, <<add_dot(acc, dot?)::binary, ?e, sign, digit>>)
 
-  # When floats are expressed in scientific notation, :erlang.binary_to_float/1 can raise an
-  # ArgumentError if the e exponent is too big. For example, "1.0e400". Because of this, we
-  # rescue the ArgumentError here and return an error.
-  defp parse_unsigned(rest, dot?, true = _e?, acc) do
-    :erlang.binary_to_float(add_dot(acc, dot?))
-  rescue
-    ArgumentError -> :error
-  else
-    float -> {float, rest}
-  end
-
-  defp parse_unsigned(rest, dot?, false = _e?, acc),
+  defp parse_unsigned(rest, dot?, _e?, acc),
     do: {:erlang.binary_to_float(add_dot(acc, dot?)), rest}
 
   defp add_dot(acc, true), do: acc
@@ -548,20 +509,13 @@ defmodule Float do
   defp sign(1, num), do: -num
 
   @doc """
-  Returns a charlist which corresponds to the shortest text representation
+  Returns a charlist which corresponds to the text representation
   of the given float.
 
-  The underlying algorithm changes depending on the Erlang/OTP version:
-
-    * For OTP >= 24, it uses the algorithm presented in "Ryū: fast
-      float-to-string conversion" in Proceedings of the SIGPLAN '2018
-      Conference on Programming Language Design and Implementation.
-
-    * For OTP < 24, it uses the algorithm presented in "Printing Floating-Point
-      Numbers Quickly and Accurately" in Proceedings of the SIGPLAN '1996
-      Conference on Programming Language Design and Implementation.
-
-  For a configurable representation, use `:erlang.float_to_list/2`.
+  It uses the shortest representation according to algorithm described
+  in "Printing Floating-Point Numbers Quickly and Accurately" in
+  Proceedings of the SIGPLAN '96 Conference on Programming Language
+  Design and Implementation.
 
   ## Examples
 
@@ -575,20 +529,13 @@ defmodule Float do
   end
 
   @doc """
-  Returns a binary which corresponds to the shortest text representation
+  Returns a binary which corresponds to the text representation
   of the given float.
 
-  The underlying algorithm changes depending on the Erlang/OTP version:
-
-    * For OTP >= 24, it uses the algorithm presented in "Ryū: fast
-      float-to-string conversion" in Proceedings of the SIGPLAN '2018
-      Conference on Programming Language Design and Implementation.
-
-    * For OTP < 24, it uses the algorithm presented in "Printing Floating-Point
-      Numbers Quickly and Accurately" in Proceedings of the SIGPLAN '1996
-      Conference on Programming Language Design and Implementation.
-
-  For a configurable representation, use `:erlang.float_to_binary/2`.
+  It uses the shortest representation according to algorithm described
+  in "Printing Floating-Point Numbers Quickly and Accurately" in
+  Proceedings of the SIGPLAN '96 Conference on Programming Language
+  Design and Implementation.
 
   ## Examples
 

lib/elixir/lib/function.ex

@@ -22,7 +22,7 @@ defmodule Function do
 
   It is also possible to capture public module functions and pass them
   around as if they were anonymous functions by using the capture
-  operator `&/1`:
+  operator `Kernel.SpecialForms.&/1`:
 
       iex> add = &Kernel.+/2
       iex> add.(1, 2)

lib/elixir/lib/gen_event.ex

@@ -2,7 +2,7 @@ defmodule GenEvent do
   # Functions from this module are deprecated in elixir_dispatch.
 
   @moduledoc """
-  An event manager with event handlers behaviour.
+  A event manager with event handlers behaviour.
 
   If you are interested in implementing an event manager, please read the
   "Alternatives" section below. If you have to implement an event handler to
@@ -91,7 +91,7 @@ defmodule GenEvent do
     deprecation_message =
       "the GenEvent module is deprecated, see its documentation for alternatives"
 
-    IO.warn(deprecation_message, __CALLER__)
+    IO.warn(deprecation_message, Macro.Env.stacktrace(__CALLER__))
 
     quote location: :keep do
       @behaviour :gen_event

lib/elixir/lib/gen_server.ex

@@ -153,19 +153,14 @@ defmodule GenServer do
   detailed information. The `@doc` annotation immediately preceding
   `use GenServer` will be attached to the generated `child_spec/1` function.
 
-  When stopping the GenServer, for example by returning a `{:stop, reason, new_state}`
-  tuple from a callback, the exit reason is used by the supervisor to determine
-  whether the GenServer needs to be restarted. See the "Exit reasons and restarts"
-  section in the `Supervisor` module.
-
   ## Name registration
 
   Both `start_link/3` and `start/3` support the `GenServer` to register
   a name on start via the `:name` option. Registered names are also
   automatically cleaned up on termination. The supported values are:
 
-    * an atom - the GenServer is registered locally (to the current node)
-      with the given name using `Process.register/2`.
+    * an atom - the GenServer is registered locally with the given name
+      using `Process.register/2`.
 
     * `{:global, term}` - the GenServer is registered globally with the given
       term using the functions in the [`:global` module](`:global`).
@@ -212,7 +207,7 @@ defmodule GenServer do
   the GenServer callbacks as doing so will cause the GenServer to misbehave.
 
   Besides the synchronous and asynchronous communication provided by `call/3`
-  and `cast/2`, "regular" messages sent by functions such as `send/2`,
+  and `cast/2`, "regular" messages sent by functions such as `Kernel.send/2`,
   `Process.send_after/4` and similar, can be handled inside the `c:handle_info/2`
   callback.
 
@@ -259,20 +254,15 @@ defmodule GenServer do
   a timeout value in milliseconds; if not, `:infinity` is assumed.
   The timeout can be used to detect a lull in incoming messages.
 
-  The `timeout()` value is used as follows:
+  If the process has no messages waiting when the timeout is set and the
+  number of given milliseconds pass without any message arriving,
+  then `handle_info/2` will be called with `:timeout` as the first argument.
+  The timeout is cleared if any message is waiting or arrives before the
+  given timeout.
 
-    * If the process has any message already waiting when the `timeout()` value
-      is returned, the timeout is ignored and the waiting message is handled as
-      usual. This means that even a timeout of `0` milliseconds is not guaranteed
-      to execute (if you want to take another action immediately and unconditionally,
-      use a `:continue` instruction instead).
-
-    * If any message arrives before the specified number of milliseconds
-      elapse, the timeout is cleared and that message is handled as usual.
-
-    * Otherwise, when the specified number of milliseconds have elapsed with no
-      message arriving, `handle_info/2` is called with `:timeout` as the first
-      argument.
+  Because a message may arrive before the timeout is set, even a timeout of `0`
+  milliseconds is not guaranteed to execute. To take another action immediately
+  and unconditionally, use a `:continue` instruction.
 
   ## When (not) to use a GenServer
 
@@ -322,7 +312,7 @@ defmodule GenServer do
 
   ## Debugging with the :sys module
 
-  GenServers, as [special processes](https://www.erlang.org/doc/design_principles/spec_proc.html),
+  GenServers, as [special processes](https://erlang.org/doc/design_principles/spec_proc.html),
   can be debugged using the [`:sys` module](`:sys`).
   Through various hooks, this module allows developers to introspect the state of
   the process and trace system events that happen during its execution, such as
@@ -412,7 +402,7 @@ defmodule GenServer do
 
     * [GenServer - Elixir's Getting Started Guide](https://elixir-lang.org/getting-started/mix-otp/genserver.html)
     * [`:gen_server` module documentation](`:gen_server`)
-    * [gen_server Behaviour - OTP Design Principles](https://www.erlang.org/doc/design_principles/gen_server_concepts.html)
+    * [gen_server Behaviour - OTP Design Principles](https://erlang.org/doc/design_principles/gen_server_concepts.html)
     * [Clients and Servers - Learn You Some Erlang for Great Good!](http://learnyousomeerlang.com/clients-and-servers)
 
   """
@@ -434,10 +424,10 @@ defmodule GenServer do
   except the process is hibernated before entering the loop. See
   `c:handle_call/3` for more information on hibernation.
 
-  Returning `{:ok, state, {:continue, continue_arg}}` is similar to
+  Returning `{:ok, state, {:continue, continue}}` is similar to
   `{:ok, state}` except that immediately after entering the loop,
-  the `c:handle_continue/2` callback will be invoked with `continue_arg`
-  as the first argument and `state` as the second one.
+  the `c:handle_continue/2` callback will be invoked with the value
+  `continue` as first argument.
 
   Returning `:ignore` will cause `start_link/3` to return `:ignore` and
   the process will exit normally without entering the loop or calling
@@ -460,7 +450,7 @@ defmodule GenServer do
   """
   @callback init(init_arg :: term) ::
               {:ok, state}
-              | {:ok, state, timeout | :hibernate | {:continue, continue_arg :: term}}
+              | {:ok, state, timeout | :hibernate | {:continue, term}}
               | :ignore
               | {:stop, reason :: any}
             when state: any
@@ -487,10 +477,9 @@ defmodule GenServer do
   `GenServer` causes garbage collection and leaves a continuous heap that
   minimises the memory used by the process.
 
-  Returning `{:reply, reply, new_state, {:continue, continue_arg}}` is similar to
-  `{:reply, reply, new_state}` except that `c:handle_continue/2` will be invoked
-  immediately after with `continue_arg` as the first argument and
-  `state` as the second one.
+  Returning `{:reply, reply, new_state, {:continue, continue}}` is similar to
+  `{:reply, reply, new_state}` except `c:handle_continue/2` will be invoked
+  immediately after with the value `continue` as first argument.
 
   Hibernating should not be used aggressively as too much time could be spent
   garbage collecting. Normally it should only be used when a message is not
@@ -513,7 +502,7 @@ defmodule GenServer do
   process exits without replying as the caller will be blocking awaiting a
   reply.
 
-  Returning `{:noreply, new_state, timeout | :hibernate | {:continue, continue_arg}}`
+  Returning `{:noreply, new_state, timeout | :hibernate | {:continue, continue}}`
   is similar to `{:noreply, new_state}` except a timeout, hibernation or continue
   occurs as with a `:reply` tuple.
 
@@ -529,10 +518,9 @@ defmodule GenServer do
   """
   @callback handle_call(request :: term, from, state :: term) ::
               {:reply, reply, new_state}
-              | {:reply, reply, new_state,
-                 timeout | :hibernate | {:continue, continue_arg :: term}}
+              | {:reply, reply, new_state, timeout | :hibernate | {:continue, term}}
               | {:noreply, new_state}
-              | {:noreply, new_state, timeout | :hibernate | {:continue, continue_arg :: term}}
+              | {:noreply, new_state, timeout | :hibernate | {:continue, term}}
               | {:stop, reason, reply, new_state}
               | {:stop, reason, new_state}
             when reply: term, new_state: term, reason: term
@@ -553,10 +541,9 @@ defmodule GenServer do
   `{:noreply, new_state}` except the process is hibernated before continuing the
   loop. See `c:handle_call/3` for more information.
 
-  Returning `{:noreply, new_state, {:continue, continue_arg}}` is similar to
+  Returning `{:noreply, new_state, {:continue, continue}}` is similar to
   `{:noreply, new_state}` except `c:handle_continue/2` will be invoked
-  immediately after with `continue_arg` as the first argument and
-  `state` as the second one.
+  immediately after with the value `continue` as first argument.
 
   Returning `{:stop, reason, new_state}` stops the loop and `c:terminate/2` is
   called with the reason `reason` and state `new_state`. The process exits with
@@ -567,7 +554,7 @@ defmodule GenServer do
   """
   @callback handle_cast(request :: term, state :: term) ::
               {:noreply, new_state}
-              | {:noreply, new_state, timeout | :hibernate | {:continue, continue_arg :: term}}
+              | {:noreply, new_state, timeout | :hibernate | {:continue, term}}
               | {:stop, reason :: term, new_state}
             when new_state: term
 
@@ -584,12 +571,12 @@ defmodule GenServer do
   """
   @callback handle_info(msg :: :timeout | term, state :: term) ::
               {:noreply, new_state}
-              | {:noreply, new_state, timeout | :hibernate | {:continue, continue_arg :: term}}
+              | {:noreply, new_state, timeout | :hibernate | {:continue, term}}
               | {:stop, reason :: term, new_state}
             when new_state: term
 
   @doc """
-  Invoked to handle continue instructions.
+  Invoked to handle `continue` instructions.
 
   It is useful for performing work after initialization or for splitting the work
   in a callback in multiple steps, updating the process state along the way.
@@ -599,11 +586,11 @@ defmodule GenServer do
   This callback is optional. If one is not implemented, the server will fail
   if a continue instruction is used.
   """
-  @callback handle_continue(continue_arg, state :: term) ::
+  @callback handle_continue(continue :: term, state :: term) ::
               {:noreply, new_state}
-              | {:noreply, new_state, timeout | :hibernate | {:continue, continue_arg}}
+              | {:noreply, new_state, timeout | :hibernate | {:continue, term}}
               | {:stop, reason :: term, new_state}
-            when new_state: term, continue_arg: term
+            when new_state: term
 
   @doc """
   Invoked when the server is about to exit. It should do any cleanup required.
@@ -616,7 +603,7 @@ defmodule GenServer do
   does one of the following:
 
     * returns a `:stop` tuple
-    * raises (via `raise/2`) or exits (via `exit/1`)
+    * raises (via `Kernel.raise/2`) or exits (via `Kernel.exit/1`)
     * returns an invalid value
 
   If part of a supervision tree, a `GenServer` will receive an exit
@@ -683,7 +670,11 @@ defmodule GenServer do
             when old_vsn: term | {:down, term}
 
   @doc """
-  Invoked in some cases to retrieve a formatted version of the `GenServer` status:
+  Invoked in some cases to retrieve a formatted version of the `GenServer` status.
+
+  This callback can be useful to control the *appearance* of the status of the
+  `GenServer`. For example, it can be used to return a compact representation of
+  the `GenServer`'s state to avoid having large state terms printed.
 
     * one of `:sys.get_status/1` or `:sys.get_status/2` is invoked to get the
       status of the `GenServer`; in such cases, `reason` is `:normal`
@@ -691,10 +682,6 @@ defmodule GenServer do
     * the `GenServer` terminates abnormally and logs an error; in such cases,
       `reason` is `:terminate`
 
-  This callback can be useful to control the *appearance* of the status of the
-  `GenServer`. For example, it can be used to return a compact representation of
-  the `GenServer`'s state to avoid having large state terms printed.
-
   `pdict_and_state` is a two-elements list `[pdict, state]` where `pdict` is a
   list of `{key, value}` tuples representing the current process dictionary of
   the `GenServer` and `state` is the current state of the `GenServer`.
@@ -866,7 +853,7 @@ defmodule GenServer do
       the arguments given to GenServer.start_link/3 to the server state.
       """
 
-      IO.warn(message, env)
+      IO.warn(message, Macro.Env.stacktrace(env))
 
       quote do
         @doc false
@@ -1026,7 +1013,6 @@ defmodule GenServer do
       nil ->
         exit({:noproc, {__MODULE__, :call, [server, request, timeout]}})
 
-      # TODO: remove this clause when we require Erlang/OTP 25+
       pid when pid == self() ->
         exit({:calling_self, {__MODULE__, :call, [server, request, timeout]}})
 
@@ -1174,8 +1160,11 @@ defmodule GenServer do
 
   """
   @spec reply(from, term) :: :ok
-  def reply(client, reply) do
-    :gen.reply(client, reply)
+  def reply(client, reply)
+
+  def reply({to, tag}, reply) when is_pid(to) do
+    send(to, {tag, reply})
+    :ok
   end
 
   @doc """

lib/elixir/lib/inspect.ex

@@ -8,85 +8,16 @@ defprotocol Inspect do
   The `Inspect` protocol converts an Elixir data structure into an
   algebra document.
 
-  This is typically done when you want to customize how your own
-  structs are inspected in logs and the terminal.
-
   This documentation refers to implementing the `Inspect` protocol
   for your own data structures. To learn more about using inspect,
   see `Kernel.inspect/2` and `IO.inspect/2`.
 
-  ## Inspect representation
+  The `inspect/2` function receives the entity to be inspected
+  followed by the inspecting options, represented by the struct
+  `Inspect.Opts`. Building of the algebra document is done with
+  `Inspect.Algebra`.
 
-  There are typically three choices of inspect representation. In order
-  to understand them, let's imagine we have the following `User` struct:
-
-      defmodule User do
-        defstruct [:id, :name, :address]
-      end
-
-  Our choices are:
-
-    1. Print the struct using Elixir's struct syntax, for example:
-       `%User{address: "Earth", id: 13, name: "Jane"}`. This is the
-       default representation and best choice if all struct fields
-       are public.
-
-    2. Print using the `#User<...>` notation, for example: `#User<id: 13, name: "Jane", ...>`.
-       This notation does not emit valid Elixir code and is typically
-       used when the struct has private fields (for example, you may want
-       to hide the field `:address` to redact person identifiable information).
-
-    3. Print the struct using the expression syntax, for example:
-       `User.new(13, "Jane", "Earth")`. This assumes there is a `User.new/3`
-       function. This option is mostly used as an alternative to option 2
-       for representing custom data structures, such as `MapSet`, `Date.Range`,
-       and others.
-
-  You can implement the Inspect protocol for your own structs while
-  adhering to the conventions above. Option 1 is the default representation
-  and you can quickly achieve option 2 by deriving the `Inspect` protocol.
-  For option 3, you need your custom implementation.
-
-  ## Deriving
-
-  The `Inspect` protocol can be derived to customize the order of fields
-  (the default is alphabetical) and hide certain fields from structs,
-  so they don't show up in logs, inspects and similar. The latter is
-  especially useful for fields containing private information.
-
-  The supported options are:
-
-    * `:only` - only include the given fields when inspecting.
-
-    * `:except` - remove the given fields when inspecting.
-
-    * `:optional` - (since v1.14.0) do not include a field if it
-      matches its default value. This can be used to simplify the
-      struct representation at the cost of hiding information.
-
-  Whenever `:only` or `:except` are used to restrict fields,
-  the struct will be printed using the `#User<...>` notation,
-  as the struct can no longer be copy and pasted as valid Elixir
-  code. Let's see an example:
-
-      defmodule User do
-        @derive {Inspect, only: [:id, :name]}
-        defstruct [:id, :name, :address]
-      end
-
-      inspect(%User{id: 1, name: "Jane", address: "Earth"})
-      #=> #User<id: 1, name: "Jane", ...>
-
-  If you use only the `:optional` option, the struct will still be
-  printed as `%User{...}`.
-
-  ## Custom implementation
-
-  You can also define your custom protocol implementation by
-  defining the `inspect/2` function. The function receives the
-  entity to be inspected followed by the inspecting options,
-  represented by the struct `Inspect.Opts`. Building of the
-  algebra document is done with `Inspect.Algebra`.
+  ## Examples
 
   Many times, inspecting a structure can be implemented in function
   of existing entities. For example, here is `MapSet`'s `inspect/2`
@@ -96,24 +27,23 @@ defprotocol Inspect do
         import Inspect.Algebra
 
         def inspect(map_set, opts) do
-          concat(["MapSet.new(", Inspect.List.inspect(MapSet.to_list(map_set), opts), ")"])
+          concat(["#MapSet<", to_doc(MapSet.to_list(map_set), opts), ">"])
         end
       end
 
   The [`concat/1`](`Inspect.Algebra.concat/1`) function comes from
   `Inspect.Algebra` and it concatenates algebra documents together.
-  In the example above it is concatenating the string `"MapSet.new("`,
+  In the example above it is concatenating the string `"#MapSet<"`,
   the document returned by `Inspect.Algebra.to_doc/2`, and the final
-  string `")"`. Therefore, the MapSet with the numbers 1, 2, and 3
-  will be printed as:
+  string `">"`. We prefix the module name `#` to denote the inspect
+  presentation is not actually valid Elixir syntax.
 
-      iex> MapSet.new([1, 2, 3], fn x -> x * 2 end)
-      MapSet.new([2, 4, 6])
+  Finally, note strings themselves are valid algebra documents that
+  keep their formatting when pretty printed. This means your `Inspect`
+  implementation may simply return a string, although that will devoid
+  it of any pretty-printing.
 
-  In other words, `MapSet`'s inspect representation returns an expression
-  that, when evaluated, builds the `MapSet` itself.
-
-  ### Error handling
+  ## Error handling
 
   In case there is an error while your structure is being inspected,
   Elixir will raise an `ArgumentError` error and will automatically fall back
@@ -125,6 +55,24 @@ defprotocol Inspect do
 
       Inspect.MapSet.inspect(MapSet.new(), %Inspect.Opts{})
 
+  ## Deriving
+
+  The `Inspect` protocol can be derived to hide certain fields from
+  structs, so they don't show up in logs, inspects and similar. This
+  is especially useful for fields containing private information.
+
+  The options `:only` and `:except` can be used with `@derive` to
+  specify which fields should and should not appear in the
+  algebra document:
+
+      defmodule User do
+        @derive {Inspect, only: [:id, :name]}
+        defstruct [:id, :name, :address]
+      end
+
+      inspect(%User{id: 1, name: "Homer", address: "742 Evergreen Terrace"})
+      #=> #User<id: 1, name: "Homer", ...>
+
   """
 
   # Handle structs in Any
@@ -146,7 +94,7 @@ defimpl Inspect, for: Atom do
   require Macro
 
   def inspect(atom, opts) do
-    color(Macro.inspect_atom(:literal, atom), color_key(atom), opts)
+    color(Identifier.inspect_as_atom(atom), color_key(atom), opts)
   end
 
   defp color_key(atom) when is_boolean(atom), do: :boolean
@@ -209,7 +157,7 @@ defimpl Inspect, for: BitString do
   defp each_bit(bitstring, _counter, opts) do
     size = bit_size(bitstring)
     <<h::size(size)>> = bitstring
-    concat(Inspect.Integer.inspect(h, opts), "::size(" <> Integer.to_string(size) <> ")")
+    Inspect.Integer.inspect(h, opts) <> "::size(" <> Integer.to_string(size) <> ")"
   end
 
   @compile {:inline, decrement: 1}
@@ -262,7 +210,7 @@ defimpl Inspect, for: List do
             {escaped, _} -> [?', escaped, ?', " ++ ..."]
           end
 
-        color(IO.iodata_to_binary(inspected), :charlist, opts)
+        IO.iodata_to_binary(inspected)
 
       keyword?(term) ->
         container_doc(open, term, close, opts, &keyword/2, separator: sep, break: :strict)
@@ -274,7 +222,7 @@ defimpl Inspect, for: List do
 
   @doc false
   def keyword({key, value}, opts) do
-    key = color(Macro.inspect_atom(:key, key), :atom, opts)
+    key = color(Identifier.inspect_as_key(key), :atom, opts)
     concat(key, concat(" ", to_doc(value, opts)))
   end
 
@@ -302,33 +250,28 @@ end
 
 defimpl Inspect, for: Map do
   def inspect(map, opts) do
-    list = Map.to_list(map)
-
-    fun =
-      if Inspect.List.keyword?(list) do
-        &Inspect.List.keyword/2
-      else
-        sep = color(" => ", :map, opts)
-        &to_assoc(&1, &2, sep)
-      end
-
-    map_container_doc(list, "", opts, fun)
+    inspect(map, "", opts)
   end
 
-  def inspect(map, name, infos, opts) do
-    fun = fn %{field: field}, opts -> Inspect.List.keyword({field, Map.get(map, field)}, opts) end
-    map_container_doc(infos, name, opts, fun)
-  end
-
-  defp to_assoc({key, value}, opts, sep) do
-    concat(concat(to_doc(key, opts), sep), to_doc(value, opts))
-  end
-
-  defp map_container_doc(list, name, opts, fun) do
+  def inspect(map, name, opts) do
+    map = Map.to_list(map)
     open = color("%" <> name <> "{", :map, opts)
     sep = color(",", :map, opts)
     close = color("}", :map, opts)
-    container_doc(open, list, close, opts, fun, separator: sep, break: :strict)
+    container_doc(open, map, close, opts, traverse_fun(map, opts), separator: sep, break: :strict)
+  end
+
+  defp traverse_fun(list, opts) do
+    if Inspect.List.keyword?(list) do
+      &Inspect.List.keyword/2
+    else
+      sep = color(" => ", :map, opts)
+      &to_map(&1, &2, sep)
+    end
+  end
+
+  defp to_map({key, value}, opts, sep) do
+    concat(concat(to_doc(key, opts), sep), to_doc(value, opts))
   end
 end
 
@@ -366,31 +309,13 @@ defimpl Inspect, for: Integer do
 end
 
 defimpl Inspect, for: Float do
-  def inspect(float, opts) do
-    abs = abs(float)
-
-    formatted =
-      if abs >= 1.0 and abs < 1.0e16 and trunc(float) == float do
-        [Integer.to_string(trunc(float)), ?., ?0]
-      else
-        :io_lib_format.fwrite_g(float)
-      end
-
-    color(IO.iodata_to_binary(formatted), :number, opts)
+  def inspect(term, opts) do
+    inspected = IO.iodata_to_binary(:io_lib_format.fwrite_g(term))
+    color(inspected, :number, opts)
   end
 end
 
 defimpl Inspect, for: Regex do
-  def inspect(regex = %{opts: regex_opts}, opts) when is_list(regex_opts) do
-    concat([
-      "Regex.compile!(",
-      Inspect.BitString.inspect(regex.source, opts),
-      ", ",
-      Inspect.List.inspect(regex_opts, opts),
-      ")"
-    ])
-  end
-
   def inspect(regex, opts) do
     {escaped, _} =
       regex.source
@@ -422,12 +347,9 @@ defimpl Inspect, for: Function do
     name = fun_info[:name]
 
     cond do
-      not is_atom(mod) ->
-        "#Function<#{uniq(fun_info)}/#{fun_info[:arity]}>"
-
       fun_info[:type] == :external and fun_info[:env] == [] ->
-        inspected_as_atom = Macro.inspect_atom(:literal, mod)
-        inspected_as_function = Macro.inspect_atom(:remote_call, name)
+        inspected_as_atom = Identifier.inspect_as_atom(mod)
+        inspected_as_function = Identifier.inspect_as_function(name)
         "&#{inspected_as_atom}.#{inspected_as_function}/#{fun_info[:arity]}"
 
       match?('elixir_compiler_' ++ _, Atom.to_charlist(mod)) ->
@@ -443,7 +365,7 @@ defimpl Inspect, for: Function do
   end
 
   defp default_inspect(mod, fun_info) do
-    inspected_as_atom = Macro.inspect_atom(:literal, mod)
+    inspected_as_atom = Identifier.inspect_as_atom(mod)
     extracted_name = extract_name(fun_info[:name])
     "#Function<#{uniq(fun_info)}/#{fun_info[:arity]} in #{inspected_as_atom}#{extracted_name}>"
   end
@@ -455,10 +377,10 @@ defimpl Inspect, for: Function do
   defp extract_name(name) do
     case Identifier.extract_anonymous_fun_parent(name) do
       {name, arity} ->
-        "." <> Macro.inspect_atom(:remote_call, name) <> "/" <> arity
+        "." <> Identifier.inspect_as_function(name) <> "/" <> arity
 
       :error ->
-        "." <> Macro.inspect_atom(:remote_call, name)
+        "." <> Identifier.inspect_as_function(name)
     end
   end
 
@@ -467,36 +389,6 @@ defimpl Inspect, for: Function do
   end
 end
 
-defimpl Inspect, for: Inspect.Error do
-  @impl true
-  def inspect(%{stacktrace: stacktrace} = inspect_error, _opts) do
-    message = Exception.message(inspect_error)
-    format_output(message, stacktrace)
-  end
-
-  defp format_output(message, [_ | _] = stacktrace) do
-    stacktrace = Exception.format_stacktrace(stacktrace)
-
-    """
-    #Inspect.Error<
-    #{Inspect.Error.pad(message, 2)}
-
-      Stacktrace:
-
-    #{stacktrace}
-    >\
-    """
-  end
-
-  defp format_output(message, []) do
-    """
-    #Inspect.Error<
-      #{Inspect.Error.pad(message, 2)}
-    >\
-    """
-  end
-end
-
 defimpl Inspect, for: PID do
   def inspect(pid, _opts) do
     "#PID" <> IO.iodata_to_binary(:erlang.pid_to_list(pid))
@@ -521,11 +413,11 @@ defimpl Inspect, for: Any do
     fields = Map.keys(struct) -- [:__exception__, :__struct__]
     only = Keyword.get(options, :only, fields)
     except = Keyword.get(options, :except, [])
-    optional = Keyword.get(options, :optional, [])
 
-    :ok = validate_option(:only, only, fields, module)
-    :ok = validate_option(:except, except, fields, module)
-    :ok = validate_option(:optional, optional, fields, module)
+    filtered_fields =
+      fields
+      |> Enum.reject(&(&1 in except))
+      |> Enum.filter(&(&1 in only))
 
     inspect_module =
       if fields == only and except == [] do
@@ -534,86 +426,45 @@ defimpl Inspect, for: Any do
         Inspect.Any
       end
 
-    filtered_fields =
-      fields
-      |> Enum.reject(&(&1 in except))
-      |> Enum.filter(&(&1 in only))
-
-    optional? =
-      if optional == [] do
-        false
-      else
-        optional_map = for field <- optional, into: %{}, do: {field, Map.fetch!(struct, field)}
-
-        quote do
-          case unquote(Macro.escape(optional_map)) do
-            %{^var!(field) => var!(default)} ->
-              var!(default) == Map.get(var!(struct), var!(field))
-
-            %{} ->
-              false
-          end
-        end
-      end
-
     quote do
       defimpl Inspect, for: unquote(module) do
         def inspect(var!(struct), var!(opts)) do
-          var!(infos) =
-            for %{field: var!(field)} = var!(info) <- unquote(module).__info__(:struct),
-                var!(field) in unquote(filtered_fields) and not unquote(optional?),
-                do: var!(info)
-
-          var!(name) = Macro.inspect_atom(:literal, unquote(module))
-          unquote(inspect_module).inspect(var!(struct), var!(name), var!(infos), var!(opts))
+          var!(map) = Map.take(var!(struct), unquote(filtered_fields))
+          var!(name) = Identifier.inspect_as_atom(unquote(module))
+          unquote(inspect_module).inspect(var!(map), var!(name), var!(opts))
         end
       end
     end
   end
 
-  defp validate_option(option, option_list, fields, module) do
-    case option_list -- fields do
-      [] ->
-        :ok
-
-      unknown_fields ->
-        raise ArgumentError,
-              "unknown fields #{Kernel.inspect(unknown_fields)} in #{Kernel.inspect(option)} " <>
-                "when deriving the Inspect protocol for #{Kernel.inspect(module)}"
-    end
-  end
-
   def inspect(%module{} = struct, opts) do
     try do
-      {module.__struct__(), module.__info__(:struct)}
+      module.__struct__()
     rescue
       _ -> Inspect.Map.inspect(struct, opts)
     else
-      {dunder, fields} ->
+      dunder ->
         if Map.keys(dunder) == Map.keys(struct) do
-          infos =
-            for %{field: field} = info <- fields,
-                field not in [:__struct__, :__exception__],
-                do: info
-
-          Inspect.Map.inspect(struct, Macro.inspect_atom(:literal, module), infos, opts)
+          pruned = Map.drop(struct, [:__struct__, :__exception__])
+          Inspect.Map.inspect(pruned, Identifier.inspect_as_atom(module), opts)
         else
           Inspect.Map.inspect(struct, opts)
         end
     end
   end
 
-  def inspect(map, name, infos, opts) do
+  def inspect(map, name, opts) do
+    map = Map.to_list(map) ++ [:...]
     open = color("#" <> name <> "<", :map, opts)
     sep = color(",", :map, opts)
     close = color(">", :map, opts)
 
     fun = fn
-      %{field: field}, opts -> Inspect.List.keyword({field, Map.get(map, field)}, opts)
+      {key, value}, opts -> Inspect.List.keyword({key, value}, opts)
       :..., _opts -> "..."
     end
 
-    container_doc(open, infos ++ [:...], close, opts, fun, separator: sep, break: :strict)
+    container_doc(open, map, close, opts, fun, separator: sep, break: :strict)
   end
 end
 

lib/elixir/lib/inspect/algebra.ex

@@ -32,7 +32,7 @@ defmodule Inspect.Opts do
       to pass the custom options through.
 
     * `:inspect_fun` (since v1.9.0) - a function to build algebra documents.
-      Defaults to `Inspect.Opts.default_inspect_fun/0`.
+      Defaults to `Inspect.inspect/2`.
 
     * `:limit` - limits the number of items that are inspected for tuples,
       bitstrings, maps, lists and any other collection of items, with the exception of
@@ -53,7 +53,7 @@ defmodule Inspect.Opts do
     * `:safe` - when `false`, failures while inspecting structs will be raised
       as errors instead of being wrapped in the `Inspect.Error` exception. This
       is useful when debugging failures and crashes for custom inspect
-      implementations. Defaults to `true`.
+      implementations.
 
     * `:structs` - when `false`, structs are not formatted by the inspect
       protocol, they are instead printed as maps. Defaults to `true`.
@@ -64,7 +64,6 @@ defmodule Inspect.Opts do
       `:atom`, `:binary`, `:boolean`, `:list`, `:map`, `:number`, `:regex`,
       `:string`, and `:tuple`. Custom data types may provide their own options.
       Colors can be any `t:IO.ANSI.ansidata/0` as accepted by `IO.ANSI.format/1`.
-      A default list of colors can be retrieved from `IO.ANSI.syntax_colors/0`.
 
     * `:width` - number of characters per line used when pretty is `true` or when
       printing to IO devices. Set to `0` to force each item to be printed on its
@@ -90,9 +89,11 @@ defmodule Inspect.Opts do
 
   @type color_key :: atom
 
+  # TODO: Remove :char_lists key and :as_char_lists value on v2.0
   @type t :: %__MODULE__{
           base: :decimal | :binary | :hex | :octal,
           binaries: :infer | :as_binaries | :as_strings,
+          char_lists: :infer | :as_lists | :as_char_lists,
           charlists: :infer | :as_lists | :as_charlists,
           custom_options: keyword,
           inspect_fun: (any, t -> Inspect.Algebra.t()),
@@ -104,62 +105,13 @@ defmodule Inspect.Opts do
           syntax_colors: [{color_key, IO.ANSI.ansidata()}],
           width: non_neg_integer | :infinity
         }
+end
 
-  @doc """
-  Builds an `Inspect.Opts` struct.
+defmodule Inspect.Error do
+  @moduledoc """
+  Raised when a struct cannot be inspected.
   """
-  @doc since: "1.13.0"
-  @spec new(keyword()) :: t
-  def new(opts) do
-    struct(%Inspect.Opts{inspect_fun: default_inspect_fun()}, opts)
-  end
-
-  @doc """
-  Returns the default inspect function.
-  """
-  @doc since: "1.13.0"
-  @spec default_inspect_fun() :: (term, t -> Inspect.Algebra.t())
-  def default_inspect_fun do
-    :persistent_term.get({__MODULE__, :inspect_fun}, &Inspect.inspect/2)
-  end
-
-  @doc """
-  Sets the default inspect function.
-
-  Set this option with care as it will change how all values
-  in the system are inspected. The main use of this functionality
-  is to provide an entry point to filter inspected values,
-  in order for entities to comply with rules and legislations
-  on data security and data privacy.
-
-  It is **extremely discouraged** for libraries to set their own
-  function as this must be controlled by applications. Libraries
-  should instead define their own structs with custom inspect
-  implementations. If a library must change the default inspect
-  function, then it is best to define to ask users of your library
-  to explicitly call `default_inspect_fun/1` with your function of
-  choice.
-
-  The default is `Inspect.inspect/2`.
-
-  ## Examples
-
-      previous_fun = Inspect.Opts.default_inspect_fun()
-
-      Inspect.Opts.default_inspect_fun(fn
-        %{address: _} = map, opts ->
-          previous_fun.(%{map | address: "[REDACTED]"}, opts)
-
-        value, opts ->
-          previous_fun.(value, opts)
-      end)
-
-  """
-  @doc since: "1.13.0"
-  @spec default_inspect_fun((term, t -> Inspect.Algebra.t())) :: :ok
-  def default_inspect_fun(fun) when is_function(fun, 2) do
-    :persistent_term.put({__MODULE__, :inspect_fun}, fun)
-  end
+  defexception [:message]
 end
 
 defmodule Inspect.Algebra do
@@ -254,18 +206,12 @@ defmodule Inspect.Algebra do
           | doc_group
           | doc_nest
           | doc_string
-          | doc_limit
 
   @typep doc_string :: {:doc_string, t, non_neg_integer}
   defmacrop doc_string(string, length) do
     quote do: {:doc_string, unquote(string), unquote(length)}
   end
 
-  @typep doc_limit :: {:doc_limit, t, pos_integer | :infinity}
-  defmacrop doc_limit(doc, limit) do
-    quote do: {:doc_limit, unquote(doc), unquote(limit)}
-  end
-
   @typep doc_cons :: {:doc_cons, t, t}
   defmacrop doc_cons(left, right) do
     quote do: {:doc_cons, unquote(left), unquote(right)}
@@ -315,8 +261,7 @@ defmodule Inspect.Algebra do
     :doc_force,
     :doc_group,
     :doc_nest,
-    :doc_string,
-    :doc_limit
+    :doc_string
   ]
 
   defguard is_doc(doc)
@@ -353,28 +298,19 @@ defmodule Inspect.Algebra do
             try do
               Process.put(:inspect_trap, true)
 
-              inspected_struct =
-                struct
-                |> Inspect.Map.inspect(%{
-                  opts
-                  | syntax_colors: [],
-                    inspect_fun: Inspect.Opts.default_inspect_fun()
-                })
-                |> format(opts.width)
-                |> IO.iodata_to_binary()
+              res = Inspect.Map.inspect(struct, %{opts | syntax_colors: []})
+              res = IO.iodata_to_binary(format(res, :infinity))
 
-              inspect_error =
-                Inspect.Error.exception(
-                  exception: caught_exception,
-                  stacktrace: __STACKTRACE__,
-                  inspected_struct: inspected_struct
-                )
+              message =
+                "got #{inspect(caught_exception.__struct__)} with message " <>
+                  "#{inspect(Exception.message(caught_exception))} while inspecting #{res}"
+
+              exception = Inspect.Error.exception(message: message)
 
               if opts.safe do
-                opts = %{opts | inspect_fun: Inspect.Opts.default_inspect_fun()}
-                Inspect.inspect(inspect_error, opts)
+                Inspect.inspect(exception, opts)
               else
-                reraise(inspect_error, __STACKTRACE__)
+                reraise(exception, __STACKTRACE__)
               end
             after
               Process.delete(:inspect_trap)
@@ -468,9 +404,8 @@ defmodule Inspect.Algebra do
 
   defp container_each([term | terms], limit, opts, fun, acc, simple?)
        when is_list(terms) and is_limit(limit) do
-    new_limit = decrement(limit)
-    doc = fun.(term, %{opts | limit: new_limit})
-    limit = if doc == :doc_nil, do: limit, else: new_limit
+    limit = decrement(limit)
+    doc = fun.(term, %{opts | limit: limit})
     container_each(terms, limit, opts, fun, [doc | acc], simple? and simple?(doc))
   end
 
@@ -582,10 +517,6 @@ defmodule Inspect.Algebra do
     doc_cons(doc1, doc2)
   end
 
-  def no_limit(doc) do
-    doc_limit(doc, :infinity)
-  end
-
   @doc ~S"""
   Concatenates a list of documents returning a new document.
 
@@ -605,7 +536,7 @@ defmodule Inspect.Algebra do
   Colors a document if the `color_key` has a color in the options.
   """
   @doc since: "1.4.0"
-  @spec color(t, Inspect.Opts.color_key(), Inspect.Opts.t()) :: t
+  @spec color(t, Inspect.Opts.color_key(), Inspect.Opts.t()) :: doc_color
   def color(doc, color_key, %Inspect.Opts{syntax_colors: syntax_colors}) when is_doc(doc) do
     if precolor = Keyword.get(syntax_colors, color_key) do
       postcolor = Keyword.get(syntax_colors, :reset, :reset)
@@ -635,7 +566,7 @@ defmodule Inspect.Algebra do
       ["hello", "\n     ", "world"]
 
   """
-  @spec nest(t, non_neg_integer | :cursor | :reset, :always | :break) :: doc_nest | t
+  @spec nest(t, non_neg_integer | :cursor | :reset, :always | :break) :: doc_nest
   def nest(doc, level, mode \\ :always)
 
   def nest(doc, :cursor, mode) when is_doc(doc) and mode in [:always, :break] do
@@ -976,7 +907,7 @@ defmodule Inspect.Algebra do
   @typep mode :: :flat | :flat_no_break | :break | :break_no_flat
 
   @spec fits?(
-          width :: non_neg_integer() | :infinity,
+          width :: non_neg_integer(),
           column :: non_neg_integer(),
           break? :: boolean(),
           entries
@@ -1041,17 +972,9 @@ defmodule Inspect.Algebra do
   defp fits?(w, k, b?, [{i, m, doc_group(x, _)} | t]),
     do: fits?(w, k, b?, [{i, m, x} | {:tail, b?, t}])
 
-  defp fits?(w, k, b?, [{i, m, doc_limit(x, :infinity)} | t]) when w != :infinity,
-    do: fits?(:infinity, k, b?, [{i, :flat, x}, {i, m, doc_limit(empty(), w)} | t])
-
-  defp fits?(_w, k, b?, [{i, m, doc_limit(x, w)} | t]),
-    do: fits?(w, k, b?, [{i, m, x} | t])
-
-  @spec format(
-          width :: non_neg_integer() | :infinity,
-          column :: non_neg_integer(),
-          [{integer, mode, t}]
-        ) :: [binary]
+  @spec format(width :: non_neg_integer() | :infinity, column :: non_neg_integer(), [
+          {integer, mode, t}
+        ]) :: [binary]
   defp format(_, _, []), do: []
   defp format(w, k, [{_, _, :doc_nil} | t]), do: format(w, k, t)
   defp format(w, _, [{i, _, :doc_line} | t]), do: [indent(i) | format(w, i, t)]
@@ -1105,15 +1028,6 @@ defmodule Inspect.Algebra do
     end
   end
 
-  # Limit is set to infinity and then reverts
-  defp format(w, k, [{i, m, doc_limit(x, :infinity)} | t]) when w != :infinity do
-    format(:infinity, k, [{i, :flat, x}, {i, m, doc_limit(empty(), w)} | t])
-  end
-
-  defp format(_w, k, [{i, m, doc_limit(x, w)} | t]) do
-    format(w, k, [{i, m, x} | t])
-  end
-
   defp collapse(["\n" <> _ | t], max, count, i) do
     collapse(t, max, count + 1, i)
   end

lib/elixir/lib/integer.ex

@@ -4,11 +4,11 @@ defmodule Integer do
 
   Some functions that work on integers are found in `Kernel`:
 
-    * `Kernel.abs/1`
-    * `Kernel.div/2`
-    * `Kernel.max/2`
-    * `Kernel.min/2`
-    * `Kernel.rem/2`
+    * `abs/1`
+    * `div/2`
+    * `max/2`
+    * `min/2`
+    * `rem/2`
 
   """
 
@@ -104,13 +104,19 @@ defmodule Integer do
   @spec pow(integer, non_neg_integer) :: integer
   def pow(base, exponent) when is_integer(base) and is_integer(exponent) do
     if exponent < 0, do: :erlang.error(:badarith, [base, exponent])
-    base ** exponent
+    guarded_pow(base, exponent)
   end
 
+  # https://en.wikipedia.org/wiki/Exponentiation_by_squaring
+  defp guarded_pow(_, 0), do: 1
+  defp guarded_pow(b, 1), do: b
+  defp guarded_pow(b, e) when (e &&& 1) == 0, do: guarded_pow(b * b, e >>> 1)
+  defp guarded_pow(b, e), do: b * guarded_pow(b * b, e >>> 1)
+
   @doc """
   Computes the modulo remainder of an integer division.
 
-  This function performs a [floored division](`floor_div/2`), which means that
+  `Integer.mod/2` uses floored division, which means that
   the result will always have the sign of the `divisor`.
 
   Raises an `ArithmeticError` exception if one of the arguments is not an
@@ -142,8 +148,8 @@ defmodule Integer do
   Raises an `ArithmeticError` exception if one of the arguments is not an
   integer, or when the `divisor` is `0`.
 
-  This function performs a *floored* integer division, which means that
-  the result will always be rounded towards negative infinity.
+  `Integer.floor_div/2` performs *floored* integer division. This means that
+  the result is always rounded towards negative infinity.
 
   If you want to perform truncated integer division (rounding towards zero),
   use `Kernel.div/2` instead.
@@ -430,7 +436,7 @@ defmodule Integer do
   @doc """
   Returns the extended greatest common divisor of the two given integers.
 
-  This function uses the extended Euclidean algorithm to return a three-element tuple with the `gcd`
+  It uses the Extended Euclidean algorithm to return a three-element tuple with the `gcd`
   and the coefficients `m` and `n` of Bézout's identity such that:
 
       gcd(a, b) = m*a + n*b
@@ -462,8 +468,8 @@ defmodule Integer do
   @doc since: "1.12.0"
   @spec extended_gcd(integer, integer) :: {non_neg_integer, integer, integer}
   def extended_gcd(0, 0), do: {0, 0, 0}
-  def extended_gcd(0, b), do: {b, 0, 1}
-  def extended_gcd(a, 0), do: {a, 1, 0}
+  def extended_gcd(0, n), do: {n, 0, 1}
+  def extended_gcd(n, 0), do: {n, 1, 0}
 
   def extended_gcd(integer1, integer2) when is_integer(integer1) and is_integer(integer2) do
     extended_gcd(integer2, integer1, 0, 1, 1, 0)

lib/elixir/lib/io.ex

@@ -122,14 +122,14 @@ defmodule IO do
   @type nodata :: {:error, term} | :eof
   @type chardata :: String.t() | maybe_improper_list(char | chardata, String.t() | [])
 
-  defguardp is_device(term) when is_atom(term) or is_pid(term)
   defguardp is_iodata(data) when is_list(data) or is_binary(data)
 
   @doc """
   Reads from the IO `device`.
 
-  The `device` is iterated by the given number of characters, line by line if
-  `:line` is given, or until `:eof`.
+  The `device` is iterated by the given number of characters or line by line if
+  `:line` is given.
+  Alternatively, if `:all` is given, then whole `device` is returned.
 
   It returns:
 
@@ -141,24 +141,14 @@ defmodule IO do
       for instance, `{:error, :estale}` if reading from an
       NFS volume
 
+  If `:all` is given, `:eof` is never returned, but an
+  empty string in case the device has reached EOF.
   """
-  @spec read(device, :eof | :line | non_neg_integer) :: chardata | nodata
+  @spec read(device, :all | :line | non_neg_integer) :: chardata | nodata
   def read(device \\ :stdio, line_or_chars)
 
-  # TODO: Deprecate me on v1.17
   def read(device, :all) do
-    with :eof <- read(device, :eof) do
-      with [_ | _] = opts <- :io.getopts(device),
-           false <- Keyword.get(opts, :binary, true) do
-        ''
-      else
-        _ -> ""
-      end
-    end
-  end
-
-  def read(device, :eof) do
-    getn(device, '', :eof)
+    do_read_all(map_dev(device), :empty)
   end
 
   def read(device, :line) do
@@ -169,20 +159,35 @@ defmodule IO do
     :io.get_chars(map_dev(device), '', count)
   end
 
+  defp do_read_all(mapped_dev, acc) do
+    case :io.get_line(mapped_dev, "") do
+      line when is_binary(line) or is_list(line) -> do_read_all(mapped_dev, concat(acc, line))
+      :eof -> read_eof(mapped_dev, acc)
+      other -> other
+    end
+  end
+
+  defp concat(:empty, line), do: line
+  defp concat(acc, line) when is_binary(acc), do: acc <> line
+  defp concat(acc, line) when is_list(acc), do: acc ++ line
+
+  defp read_eof(device, :empty) do
+    with [_ | _] = opts <- :io.getopts(device),
+         false <- Keyword.get(opts, :binary, true) do
+      ''
+    else
+      _ -> ""
+    end
+  end
+
+  defp read_eof(_device, acc), do: acc
+
   @doc """
   Reads from the IO `device`. The operation is Unicode unsafe.
 
-  The `device` is iterated as specified by the `line_or_chars` argument:
-
-    * if `line_or_chars` is an integer, it represents a number of bytes. The device is
-      iterated by that number of bytes.
-
-    * if `line_or_chars` is `:line`, the device is iterated line by line.
-
-    * if `line_or_chars` is `:eof`, the device is iterated until `:eof`. `line_or_chars`
-      can only be `:eof` since Elixir 1.13.0. `:eof` replaces the deprecated `:all`,
-      with the difference that `:all` returns `""` on end of file, while `:eof` returns
-      `:eof` itself.
+  The `device` is iterated by the given number of bytes or line by line if
+  `:line` is given.
+  Alternatively, if `:all` is given, then whole `device` is returned.
 
   It returns:
 
@@ -194,19 +199,17 @@ defmodule IO do
       for instance, `{:error, :estale}` if reading from an
       NFS volume
 
+  If `:all` is given, `:eof` is never returned, but an
+  empty string in case the device has reached EOF.
+
   Note: do not use this function on IO devices in Unicode mode
   as it will return the wrong result.
   """
-  @spec binread(device, :eof | :line | non_neg_integer) :: iodata | nodata
+  @spec binread(device, :all | :line | non_neg_integer) :: iodata | nodata
   def binread(device \\ :stdio, line_or_chars)
 
-  # TODO: Deprecate me on v1.17
   def binread(device, :all) do
-    with :eof <- binread(device, :eof), do: ""
-  end
-
-  def binread(device, :eof) do
-    binread_eof(map_dev(device), "")
+    do_binread_all(map_dev(device), "")
   end
 
   def binread(device, :line) do
@@ -224,10 +227,10 @@ defmodule IO do
   end
 
   @read_all_size 4096
-  defp binread_eof(mapped_dev, acc) do
+  defp do_binread_all(mapped_dev, acc) do
     case :file.read(mapped_dev, @read_all_size) do
-      {:ok, data} -> binread_eof(mapped_dev, acc <> data)
-      :eof -> if acc == "", do: :eof, else: acc
+      {:ok, data} -> do_binread_all(mapped_dev, acc <> data)
+      :eof -> acc
       other -> other
     end
   end
@@ -290,29 +293,19 @@ defmodule IO do
 
   """
   @spec puts(device, chardata | String.Chars.t()) :: :ok
-  def puts(device \\ :stdio, item) when is_device(device) do
+  def puts(device \\ :stdio, item) do
     :io.put_chars(map_dev(device), [to_chardata(item), ?\n])
   end
 
   @doc """
-  Writes a `message` to stderr, along with the given `stacktrace_info`.
-
-  The `stacktrace_info` must be one of:
-
-    * a `__STACKTRACE__`, where all entries in the stacktrace will be
-      included in the error message
-
-    * a `Macro.Env` structure (since v1.14.0), where a single stacktrace
-      entry from the compilation environment will be used
-
-    * a keyword list with at least the `:file` option representing
-      a single stacktrace entry (since v1.14.0). The `:line`, `:module`,
-      `:function` options are also supported
+  Writes a `message` to stderr, along with the given `stacktrace`.
 
   This function also notifies the compiler a warning was printed
   (in case --warnings-as-errors was enabled). It returns `:ok`
   if it succeeds.
 
+  An empty list can be passed to avoid stacktrace printing.
+
   ## Examples
 
       stacktrace = [{MyApp, :main, 1, [file: 'my_app.ex', line: 4]}]
@@ -321,34 +314,10 @@ defmodule IO do
       #=>   my_app.ex:4: MyApp.main/1
 
   """
-  @spec warn(chardata | String.Chars.t(), Exception.stacktrace() | keyword() | Macro.Env.t()) ::
-          :ok
-  def warn(message, stacktrace_info)
-
+  @spec warn(chardata | String.Chars.t(), Exception.stacktrace()) :: :ok
   def warn(message, []) do
     message = [to_chardata(message), ?\n]
-    :elixir_errors.log_and_print_warning(0, nil, message, message)
-  end
-
-  def warn(message, %Macro.Env{} = env) do
-    warn(message, Macro.Env.stacktrace(env))
-  end
-
-  def warn(message, [{_, _} | _] = keyword) do
-    if file = keyword[:file] do
-      warn(
-        message,
-        %{
-          __ENV__
-          | module: keyword[:module],
-            function: keyword[:function],
-            line: keyword[:line],
-            file: file
-        }
-      )
-    else
-      warn(message, [])
-    end
+    :elixir_errors.io_warn(0, nil, message, message)
   end
 
   def warn(message, [{_, _, _, opts} | _] = stacktrace) do
@@ -357,7 +326,7 @@ defmodule IO do
     line = opts[:line]
     file = opts[:file]
 
-    :elixir_errors.log_and_print_warning(
+    :elixir_errors.io_warn(
       line || 0,
       file && List.to_string(file),
       message,
@@ -459,9 +428,9 @@ defmodule IO do
   See `inspect/2` for a full list of options.
   """
   @spec inspect(device, item, keyword) :: item when item: var
-  def inspect(device, item, opts) when is_device(device) and is_list(opts) do
+  def inspect(device, item, opts) when is_list(opts) do
     label = if label = opts[:label], do: [to_chardata(label), ": "], else: []
-    opts = Inspect.Opts.new(opts)
+    opts = struct(Inspect.Opts, opts)
     doc = Inspect.Algebra.group(Inspect.Algebra.to_doc(item, opts))
     chardata = Inspect.Algebra.format(doc, opts.width)
     puts(device, [label, chardata])
@@ -476,18 +445,12 @@ defmodule IO do
   Otherwise, `count` is the number of raw bytes to be retrieved.
 
   See `IO.getn/3` for a description of return values.
+
   """
-  @spec getn(
-          device | chardata | String.Chars.t(),
-          pos_integer | :eof | chardata | String.Chars.t()
-        ) ::
+  @spec getn(device | chardata | String.Chars.t(), pos_integer | chardata | String.Chars.t()) ::
           chardata | nodata
   def getn(prompt, count \\ 1)
 
-  def getn(prompt, :eof) do
-    getn(:stdio, prompt, :eof)
-  end
-
   def getn(prompt, count) when is_integer(count) and count > 0 do
     getn(:stdio, prompt, count)
   end
@@ -514,27 +477,11 @@ defmodule IO do
       NFS volume
 
   """
-  @spec getn(device, chardata | String.Chars.t(), pos_integer | :eof) :: chardata | nodata
-  def getn(device, prompt, :eof) do
-    getn_eof(map_dev(device), to_chardata(prompt), [])
-  end
-
+  @spec getn(device, chardata | String.Chars.t(), pos_integer) :: chardata | nodata
   def getn(device, prompt, count) when is_integer(count) and count > 0 do
     :io.get_chars(map_dev(device), to_chardata(prompt), count)
   end
 
-  defp getn_eof(device, prompt, acc) do
-    case :io.get_line(device, prompt) do
-      line when is_binary(line) or is_list(line) -> getn_eof(device, '', [line | acc])
-      :eof -> wrap_eof(:lists.reverse(acc))
-      other -> other
-    end
-  end
-
-  defp wrap_eof([h | _] = acc) when is_binary(h), do: IO.iodata_to_binary(acc)
-  defp wrap_eof([h | _] = acc) when is_list(h), do: :lists.flatten(acc)
-  defp wrap_eof([]), do: :eof
-
   @doc ~S"""
   Reads a line from the IO `device`.
 
@@ -588,7 +535,7 @@ defmodule IO do
   Note that an IO stream has side effects and every time
   you go over the stream you may get different results.
 
-  `stream/0` has been introduced in Elixir v1.12.0,
+  `stream/1` has been introduced in Elixir v1.12.0,
   while `stream/2` has been available since v1.0.0.
 
   ## Examples
@@ -633,7 +580,7 @@ defmodule IO do
   Finally, do not use this function on IO devices in Unicode
   mode as it will return the wrong result.
 
-  `binstream/0` has been introduced in Elixir v1.12.0,
+  `binstream/1` has been introduced in Elixir v1.12.0,
   while `binstream/2` has been available since v1.0.0.
   """
   @spec binstream(device, :line | pos_integer) :: Enumerable.t()
@@ -665,8 +612,6 @@ defmodule IO do
 
   """
   @spec chardata_to_string(chardata) :: String.t()
-  def chardata_to_string(chardata)
-
   def chardata_to_string(string) when is_binary(string) do
     string
   end

lib/elixir/lib/io/ansi.ex

@@ -3,7 +3,6 @@ defmodule IO.ANSI.Sequence do
 
   defmacro defsequence(name, code, terminator \\ "m") do
     quote bind_quoted: [name: name, code: code, terminator: terminator] do
-      @spec unquote(name)() :: String.t()
       def unquote(name)() do
         "\e[#{unquote(code)}#{unquote(terminator)}"
       end
@@ -69,34 +68,6 @@ defmodule IO.ANSI do
     Application.get_env(:elixir, :ansi_enabled, false)
   end
 
-  @doc """
-  Syntax colors to be used by `Inspect`.
-
-  Those colors are used throughout Elixir's standard library,
-  such as `dbg/2` and `IEx`.
-
-  The colors can be changed by setting the `:ansi_syntax_colors`
-  in the `:elixir` application configuration. Configuration for
-  most built-in data types are supported: `:atom`, `:binary`,
-  `:boolean`, `:charlist`, `:list`, `:map`, `:nil`, `:number`,
-  `:string`, and `:tuple`. The default is:
-
-      [
-        atom: :cyan
-        boolean: :magenta,
-        charlist: :yellow,
-        nil: :magenta,
-        number: :yellow,
-        string: :green
-      ]
-
-  """
-  @doc since: "1.14.0"
-  @spec syntax_colors :: Keyword.t(ansidata)
-  def syntax_colors do
-    Application.fetch_env!(:elixir, :ansi_syntax_colors)
-  end
-
   @doc "Sets foreground color."
   @spec color(0..255) :: String.t()
   def color(code) when code in 0..255, do: "\e[38;5;#{code}m"
@@ -280,9 +251,8 @@ defmodule IO.ANSI do
       [[[[[[], "Hello, "] | "\e[31m"] | "\e[1m"], "world!"] | "\e[0m"]
 
   """
-  @spec format(ansidata, boolean) :: IO.chardata()
-  def format(ansidata, emit? \\ enabled?()) when is_boolean(emit?) do
-    do_format(ansidata, [], [], emit?, :maybe)
+  def format(chardata, emit? \\ enabled?()) when is_boolean(emit?) do
+    do_format(chardata, [], [], emit?, :maybe)
   end
 
   @doc ~S"""
@@ -301,9 +271,8 @@ defmodule IO.ANSI do
       [[[[[[] | "\e[1m"], 87], 111], 114], 100]
 
   """
-  @spec format_fragment(ansidata, boolean) :: IO.chardata()
-  def format_fragment(ansidata, emit? \\ enabled?()) when is_boolean(emit?) do
-    do_format(ansidata, [], [], emit?, false)
+  def format_fragment(chardata, emit? \\ enabled?()) when is_boolean(emit?) do
+    do_format(chardata, [], [], emit?, false)
   end
 
   defp do_format([term | rest], rem, acc, emit?, append_reset) do

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

@@ -194,10 +194,6 @@ defmodule IO.ANSI.Docs do
     inline_text("*", traverse_erlang_html(entries, indent, options), options)
   end
 
-  defp traverse_erlang_html({tag, _, entries}, indent, options) when tag in [:strong, :b] do
-    inline_text("**", traverse_erlang_html(entries, indent, options), options)
-  end
-
   defp traverse_erlang_html({:code, _, entries}, indent, options) do
     inline_text("`", traverse_erlang_html(entries, indent, options), options)
   end
@@ -299,7 +295,7 @@ defmodule IO.ANSI.Docs do
   end
 
   defp inline_html?(binary) when is_binary(binary), do: true
-  defp inline_html?({tag, _, _}) when tag in [:a, :code, :em, :i, :strong, :b, :br], do: true
+  defp inline_html?({tag, _, _}) when tag in [:a, :code, :em, :i, :br], do: true
   defp inline_html?(_), do: false
 
   ## Markdown
@@ -802,14 +798,14 @@ defmodule IO.ANSI.Docs do
     Regex.replace(~r{\[([^\]]*?)\]\((.*?)\)}, text, "\\1 (\\2)")
   end
 
-  # We have four entries: **, __, *, _ and `.
+  # We have four entries: **, *, _ and `.
   #
-  # The first four behave the same while the last one is simpler
+  # The first three behave the same while the last one is simpler
   # when it comes to delimiters as it ignores spaces and escape
-  # characters. But, since the first two has two characters,
-  # we need to handle 3 cases:
+  # characters. But, since the first has two characters, we need to
+  # handle 3 cases:
   #
-  # 1. __ and **
+  # 1. **
   # 2. _ and *
   # 3. `
   #
@@ -823,8 +819,8 @@ defmodule IO.ANSI.Docs do
 
   ### Inline start
 
-  defp handle_inline(<<mark, mark, rest::binary>>, options) when mark in @single do
-    handle_inline(rest, [mark | mark], [<<mark, mark>>], [], options)
+  defp handle_inline(<<?*, ?*, rest::binary>>, options) do
+    handle_inline(rest, ?d, ["**"], [], options)
   end
 
   defp handle_inline(<<mark, rest::binary>>, options) when mark in @single do
@@ -837,10 +833,9 @@ defmodule IO.ANSI.Docs do
 
   ### Inline delimiters
 
-  defp handle_inline(<<delimiter, mark, mark, rest::binary>>, nil, buffer, acc, options)
-       when rest != "" and delimiter in @delimiters and mark in @single do
-    acc = [delimiter, Enum.reverse(buffer) | acc]
-    handle_inline(rest, [mark | mark], [<<mark, mark>>], acc, options)
+  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)
@@ -855,10 +850,9 @@ defmodule IO.ANSI.Docs do
 
   ### Clauses for handling escape
 
-  defp handle_inline(<<?\\, ?\\, mark, mark, rest::binary>>, nil, buffer, acc, options)
-       when rest != "" and mark in @single do
-    acc = [?\\, Enum.reverse(buffer) | acc]
-    handle_inline(rest, [mark | mark], [<<mark, mark>>], acc, options)
+  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)
@@ -877,8 +871,8 @@ defmodule IO.ANSI.Docs do
 
   ### Inline end
 
-  defp handle_inline(<<mark, mark, delimiter, rest::binary>>, [mark | mark], buffer, acc, options)
-       when delimiter in @delimiters and mark in @single do
+  defp handle_inline(<<?*, ?*, delimiter, rest::binary>>, ?d, buffer, acc, options)
+       when delimiter in @delimiters do
     inline_buffer = inline_buffer(buffer, options)
     handle_inline(<<delimiter, rest::binary>>, nil, [], [inline_buffer | acc], options)
   end
@@ -889,8 +883,8 @@ defmodule IO.ANSI.Docs do
     handle_inline(<<delimiter, rest::binary>>, nil, [], [inline_buffer | acc], options)
   end
 
-  defp handle_inline(<<mark, mark, rest::binary>>, [mark | mark], buffer, acc, options)
-       when rest == "" and mark in @single do
+  defp handle_inline(<<?*, ?*, rest::binary>>, ?d, buffer, acc, options)
+       when rest == "" do
     handle_inline(<<>>, nil, [], [inline_buffer(buffer, options) | acc], options)
   end
 
@@ -936,11 +930,10 @@ defmodule IO.ANSI.Docs do
 
   defp color_for(mark, colors) do
     case mark do
-      "__" -> color(:doc_bold, colors)
-      "**" -> color(:doc_bold, colors)
-      "_" -> color(:doc_underline, colors)
-      "*" -> color(:doc_underline, colors)
       "`" -> color(:doc_inline_code, colors)
+      "_" -> color(:doc_underline, colors)
+      "*" -> color(:doc_bold, colors)
+      "**" -> color(:doc_bold, colors)
     end
   end
 

lib/elixir/lib/io/stream.ex

@@ -26,11 +26,7 @@ defmodule IO.Stream do
 
   defstruct device: nil, raw: true, line_or_bytes: :line
 
-  @type t :: %__MODULE__{
-          device: IO.device(),
-          raw: boolean(),
-          line_or_bytes: :line | non_neg_integer()
-        }
+  @type t :: %__MODULE__{}
 
   @doc false
   def __build__(device, raw, line_or_bytes) do

lib/elixir/lib/kernel/cli.ex

@@ -13,12 +13,9 @@ defmodule Kernel.CLI do
     pa: [],
     pz: [],
     verbose_compile: false,
-    profile: nil,
-    pry: false
+    profile: nil
   }
 
-  @standalone_opts ["-h", "--help", "--short-version"]
-
   @doc """
   This is the API invoked by Elixir boot process.
   """
@@ -29,10 +26,6 @@ defmodule Kernel.CLI do
     System.argv(argv)
     System.no_halt(config.no_halt)
 
-    if config.pry do
-      Application.put_env(:elixir, :dbg_callback, {IEx.Pry, :dbg, []})
-    end
-
     fun = fn _ ->
       errors = process_commands(config)
 
@@ -95,7 +88,7 @@ defmodule Kernel.CLI do
       case blamed do
         %FunctionClauseError{} ->
           formatted = Exception.format_banner(kind, reason, stacktrace)
-          padded_blame = pad(FunctionClauseError.blame(blamed, &inspect/1, &blame_match/1))
+          padded_blame = pad(FunctionClauseError.blame(blamed, &inspect/1, &blame_match/2))
           [formatted, padded_blame]
 
         _ ->
@@ -183,8 +176,9 @@ defmodule Kernel.CLI do
     IO.write(:stderr, format_error(kind, reason, stacktrace))
   end
 
-  defp blame_match(%{match?: true, node: node}), do: blame_ansi(:normal, "+", node)
-  defp blame_match(%{match?: false, node: node}), do: blame_ansi(:red, "-", node)
+  defp blame_match(%{match?: true, node: node}, _), do: blame_ansi(:normal, "+", node)
+  defp blame_match(%{match?: false, node: node}, _), do: blame_ansi(:red, "-", node)
+  defp blame_match(_, string), do: string
 
   defp blame_ansi(color, no_ansi, node) do
     if IO.ANSI.enabled?() do
@@ -201,9 +195,8 @@ defmodule Kernel.CLI do
   end
 
   @elixir_internals [:elixir, :elixir_aliases, :elixir_expand, :elixir_compiler, :elixir_module] ++
-                      [:elixir_clauses, :elixir_lexical, :elixir_def, :elixir_map, :elixir_locals] ++
-                      [:elixir_erl, :elixir_erl_clauses, :elixir_erl_compiler, :elixir_erl_pass] ++
-                      [Kernel.ErrorHandler, Module.ParallelChecker]
+                      [:elixir_clauses, :elixir_lexical, :elixir_def, :elixir_map] ++
+                      [:elixir_erl, :elixir_erl_clauses, :elixir_erl_pass, Kernel.ErrorHandler]
 
   defp prune_stacktrace([{mod, _, _, _} | t]) when mod in @elixir_internals do
     prune_stacktrace(t)
@@ -223,16 +216,7 @@ defmodule Kernel.CLI do
 
   # Parse shared options
 
-  defp halt_standalone(opt) do
-    IO.puts(:stderr, "#{opt} : Standalone options can't be combined with other options")
-    System.halt(1)
-  end
-
-  defp parse_shared([opt | _], _config) when opt in @standalone_opts do
-    halt_standalone(opt)
-  end
-
-  defp parse_shared([opt | t], _config) when opt in ["-v", "--version"] do
+  defp parse_shared([opt | _t], _config) when opt in ["-v", "--version"] do
     if function_exported?(IEx, :started?, 0) and IEx.started?() do
       IO.puts("IEx " <> System.build_info()[:build])
     else
@@ -240,11 +224,7 @@ defmodule Kernel.CLI do
       IO.puts("Elixir " <> System.build_info()[:build])
     end
 
-    if t != [] do
-      halt_standalone(opt)
-    else
-      System.halt(0)
-    end
+    System.halt(0)
   end
 
   defp parse_shared(["-pa", h | t], config) do
@@ -280,11 +260,6 @@ defmodule Kernel.CLI do
     parse_shared(t, %{config | commands: [{:rpc_eval, node, h} | config.commands]})
   end
 
-  defp parse_shared(["--rpc-eval" | _], config) do
-    new_config = %{config | errors: ["--rpc-eval : wrong number of arguments" | config.errors]}
-    {[], new_config}
-  end
-
   defp parse_shared(["-r", h | t], config) do
     parse_shared(t, %{config | commands: [{:require, h} | config.commands]})
   end
@@ -324,7 +299,7 @@ defmodule Kernel.CLI do
   end
 
   defp parse_argv(["+iex" | t], config) do
-    parse_iex(t, %{config | pry: true})
+    parse_iex(t, config)
   end
 
   defp parse_argv(["-S", h | t], config) do
@@ -409,16 +384,20 @@ defmodule Kernel.CLI do
     {config, t}
   end
 
+  # This clause is here so that Kernel.CLI does not
+  # error out with "unknown option"
+  defp parse_iex(["--dot-iex", _ | t], config) do
+    parse_iex(t, config)
+  end
+
+  defp parse_iex([opt, _ | t], config) when opt in ["--remsh"] do
+    parse_iex(t, config)
+  end
+
   defp parse_iex(["-S", h | t], config) do
     {%{config | commands: [{:script, h} | config.commands]}, t}
   end
 
-  # These clauses are here so that Kernel.CLI does not error out with "unknown option"
-  defp parse_iex(["--dot-iex", _ | t], config), do: parse_iex(t, config)
-  defp parse_iex(["--remsh", _ | t], config), do: parse_iex(t, config)
-
-  defp parse_iex(["--no-pry" | t], config), do: parse_iex(t, %{config | pry: false})
-
   defp parse_iex([h | t] = list, config) do
     case h do
       "-" <> _ -> shared_option?(list, config, &parse_iex(&1, &2))

lib/elixir/lib/kernel/error_handler.ex

@@ -30,10 +30,10 @@ defmodule Kernel.ErrorHandler do
   end
 
   def ensure_compiled(module, kind, deadlock) do
-    {compiler_pid, file_pid} = :erlang.get(:elixir_compiler_info)
+    parent = :erlang.get(:elixir_compiler_pid)
     ref = :erlang.make_ref()
     modules = :elixir_module.compiler_modules()
-    send(compiler_pid, {:waiting, kind, self(), ref, file_pid, module, modules, deadlock})
+    send(parent, {:waiting, kind, self(), ref, module, modules, deadlock})
     :erlang.garbage_collect(self())
 
     receive do

lib/elixir/lib/kernel/lexical_tracker.ex

@@ -30,8 +30,8 @@ defmodule Kernel.LexicalTracker do
   end
 
   @doc false
-  def add_export(pid, module) when is_atom(module) do
-    :gen_server.cast(pid, {:add_export, module})
+  def add_require(pid, module) when is_atom(module) do
+    :gen_server.cast(pid, {:add_require, module})
   end
 
   @doc false
@@ -59,11 +59,6 @@ defmodule Kernel.LexicalTracker do
     :gen_server.cast(pid, {:alias_dispatch, module})
   end
 
-  @doc false
-  def import_quoted(pid, module, function, arities) when is_atom(module) do
-    :gen_server.cast(pid, {:import_quoted, module, function, arities})
-  end
-
   @doc false
   def add_compile_env(pid, app, path, return) do
     :gen_server.cast(pid, {:compile_env, app, path, return})
@@ -93,24 +88,23 @@ defmodule Kernel.LexicalTracker do
 
   @doc false
   def collect_unused_imports(pid) do
-    unused(pid, :unused_imports)
+    unused(pid, :import)
   end
 
   @doc false
   def collect_unused_aliases(pid) do
-    unused(pid, :unused_aliases)
+    unused(pid, :alias)
   end
 
   defp unused(pid, tag) do
-    :gen_server.call(pid, tag, @timeout)
+    :gen_server.call(pid, {:unused, tag}, @timeout)
   end
 
   # Callbacks
 
   def init(:ok) do
     state = %{
-      aliases: %{},
-      imports: %{},
+      directives: %{},
       references: %{},
       exports: %{},
       cache: %{},
@@ -122,12 +116,13 @@ defmodule Kernel.LexicalTracker do
   end
 
   @doc false
-  def handle_call(:unused_aliases, _from, state) do
-    {:reply, Enum.sort(state.aliases), state}
-  end
+  def handle_call({:unused, tag}, _from, state) do
+    directives =
+      for {{^tag, module_or_mfa}, marker} <- state.directives, is_integer(marker) do
+        {module_or_mfa, marker}
+      end
 
-  def handle_call(:unused_imports, _from, state) do
-    {:reply, Enum.sort(state.imports), state}
+    {:reply, Enum.sort(directives), state}
   end
 
   def handle_call(:references, _from, state) do
@@ -153,44 +148,12 @@ defmodule Kernel.LexicalTracker do
   end
 
   def handle_cast({:import_dispatch, module, {function, arity}, mode}, state) do
-    %{imports: imports, references: references} = state
-
-    imports =
-      case imports do
-        %{^module => modules_and_fas} ->
-          modules_and_fas
-          |> Map.delete(module)
-          |> Map.delete({function, arity})
-          |> then(&Map.put(imports, module, &1))
-
-        %{} ->
-          imports
-      end
-
-    references = add_reference(references, module, mode)
-    {:noreply, %{state | imports: imports, references: references}}
+    state = add_import_dispatch(state, module, function, arity, mode)
+    {:noreply, state}
   end
 
-  def handle_cast({:alias_dispatch, module}, %{aliases: aliases} = state) do
-    {:noreply, %{state | aliases: Map.delete(aliases, module)}}
-  end
-
-  def handle_cast({:import_quoted, module, function, arities}, state) do
-    %{imports: imports} = state
-
-    imports =
-      case imports do
-        %{^module => modules_and_fas} ->
-          arities
-          |> Enum.reduce(modules_and_fas, &Map.delete(&2, {function, &1}))
-          |> Map.delete(module)
-          |> then(&Map.put(imports, module, &1))
-
-        %{} ->
-          imports
-      end
-
-    {:noreply, %{state | imports: imports}}
+  def handle_cast({:alias_dispatch, module}, state) do
+    {:noreply, %{state | directives: add_dispatch(state.directives, module, :alias)}}
   end
 
   def handle_cast({:set_file, file}, state) do
@@ -205,25 +168,28 @@ defmodule Kernel.LexicalTracker do
     {:noreply, update_in(state.compile_env, &:ordsets.add_element({app, path, return}, &1))}
   end
 
-  def handle_cast({:add_export, module}, state) do
+  def handle_cast({:add_require, module}, state) do
     {:noreply, put_in(state.exports[module], true)}
   end
 
   def handle_cast({:add_import, module, fas, line, warn}, state) do
-    if warn do
-      imports = for module_or_fa <- [module | fas], do: {module_or_fa, line}, into: %{}
-      {:noreply, put_in(state.imports[module], imports)}
-    else
-      {:noreply, state}
-    end
+    to_remove = for {{:import, {^module, _, _}} = key, _} <- state.directives, do: key
+
+    directives =
+      state.directives
+      |> Map.drop(to_remove)
+      |> add_directive(module, line, warn, :import)
+
+    directives =
+      Enum.reduce(fas, directives, fn {function, arity}, directives ->
+        add_directive(directives, {module, function, arity}, line, warn, :import)
+      end)
+
+    {:noreply, %{state | directives: directives}}
   end
 
   def handle_cast({:add_alias, module, line, warn}, state) do
-    if warn do
-      {:noreply, put_in(state.aliases[module], line)}
-    else
-      {:noreply, state}
-    end
+    {:noreply, %{state | directives: add_directive(state.directives, module, line, warn, :alias)}}
   end
 
   @doc false
@@ -255,9 +221,31 @@ defmodule Kernel.LexicalTracker do
     do: Map.put(references, module, :compile)
 
   defp add_reference(references, module, :runtime) when is_atom(module) do
-    case references do
-      %{^module => _} -> references
-      %{} -> Map.put(references, module, :runtime)
+    case Map.fetch(references, module) do
+      {:ok, _} -> references
+      :error -> Map.put(references, module, :runtime)
     end
   end
+
+  defp add_import_dispatch(state, module, function, arity, mode) do
+    directives =
+      state.directives
+      |> add_dispatch(module, :import)
+      |> add_dispatch({module, function, arity}, :import)
+
+    references = add_reference(state.references, module, mode)
+    %{state | directives: directives, references: references}
+  end
+
+  # In the map we keep imports and aliases.
+  # If the value is a line, it was imported/aliased and has a pending warning
+  # If the value is true, it was imported/aliased and used
+  defp add_directive(directives, module_or_mfa, line, warn, tag) do
+    marker = if warn, do: line, else: true
+    Map.put(directives, {tag, module_or_mfa}, marker)
+  end
+
+  defp add_dispatch(directives, module_or_mfa, tag) do
+    Map.put(directives, {tag, module_or_mfa}, true)
+  end
 end

lib/elixir/lib/kernel/parallel_compiler.ex

@@ -3,12 +3,6 @@ defmodule Kernel.ParallelCompiler do
   A module responsible for compiling and requiring files in parallel.
   """
 
-  @typedoc "The line. 0 indicates no line."
-  @type line() :: non_neg_integer()
-  @type location() :: line() | {pos_integer(), column :: non_neg_integer}
-  @type warning() :: {file :: Path.t(), location(), message :: String.t()}
-  @type error() :: {file :: Path.t(), location(), message :: String.t()}
-
   @doc """
   Starts a task for parallel compilation.
 
@@ -22,28 +16,23 @@ defmodule Kernel.ParallelCompiler do
   """
   @doc since: "1.6.0"
   def async(fun) when is_function(fun, 0) do
-    case :erlang.get(:elixir_compiler_info) do
-      {compiler, _} ->
-        file = :erlang.get(:elixir_compiler_file)
-        dest = :erlang.get(:elixir_compiler_dest)
+    if parent = :erlang.get(:elixir_compiler_pid) do
+      file = :erlang.get(:elixir_compiler_file)
+      dest = :erlang.get(:elixir_compiler_dest)
+      {:error_handler, error_handler} = :erlang.process_info(self(), :error_handler)
 
-        {:error_handler, error_handler} = :erlang.process_info(self(), :error_handler)
-        {_parent, checker} = Module.ParallelChecker.get()
-
-        Task.async(fn ->
-          send(compiler, {:async, self()})
-          Module.ParallelChecker.put(compiler, checker)
-          :erlang.put(:elixir_compiler_info, {compiler, self()})
-          :erlang.put(:elixir_compiler_file, file)
-          dest != :undefined and :erlang.put(:elixir_compiler_dest, dest)
-          :erlang.process_flag(:error_handler, error_handler)
-          fun.()
-        end)
-
-      :undefined ->
-        raise ArgumentError,
-              "cannot spawn parallel compiler task because " <>
-                "the current file is not being compiled/required"
+      Task.async(fn ->
+        send(parent, {:async, self()})
+        :erlang.put(:elixir_compiler_pid, parent)
+        :erlang.put(:elixir_compiler_file, file)
+        dest != :undefined and :erlang.put(:elixir_compiler_dest, dest)
+        :erlang.process_flag(:error_handler, error_handler)
+        fun.()
+      end)
+    else
+      raise ArgumentError,
+            "cannot spawn parallel compiler task because " <>
+              "the current file is not being compiled/required"
     end
   end
 
@@ -97,7 +86,6 @@ defmodule Kernel.ParallelCompiler do
 
   """
   @doc since: "1.6.0"
-  @spec compile([Path.t()], keyword()) :: {:ok, [atom], [warning]} | {:error, [error], [warning]}
   def compile(files, options \\ []) when is_list(options) do
     spawn_workers(files, :compile, options)
   end
@@ -108,8 +96,6 @@ defmodule Kernel.ParallelCompiler do
   See `compile/2` for more information.
   """
   @doc since: "1.6.0"
-  @spec compile_to_path([Path.t()], Path.t(), keyword()) ::
-          {:ok, [atom], [warning]} | {:error, [error], [warning]}
   def compile_to_path(files, path, options \\ []) when is_binary(path) and is_list(options) do
     spawn_workers(files, {:compile, path}, options)
   end
@@ -135,21 +121,10 @@ defmodule Kernel.ParallelCompiler do
 
   """
   @doc since: "1.6.0"
-  @spec require([Path.t()], keyword()) ::
-          {:ok, [atom], [warning]} | {:error, [error], [warning]}
   def require(files, options \\ []) when is_list(options) do
     spawn_workers(files, :require, options)
   end
 
-  @doc """
-  Prints a warning returned by the compiler.
-  """
-  @doc since: "1.13.0"
-  @spec print_warning(warning) :: :ok
-  def print_warning({file, location, warning}) do
-    :elixir_errors.print_warning(location, file, warning)
-  end
-
   @doc false
   @deprecated "Use Kernel.ParallelCompiler.compile/2 instead"
   def files(files, options \\ []) when is_list(options) do
@@ -171,32 +146,7 @@ defmodule Kernel.ParallelCompiler do
   defp spawn_workers(files, output, options) do
     {:module, _} = :code.ensure_loaded(Kernel.ErrorHandler)
     schedulers = max(:erlang.system_info(:schedulers_online), 2)
-    {:ok, checker} = Module.ParallelChecker.start_link(schedulers)
-
-    try do
-      outcome = spawn_workers(schedulers, checker, files, output, options)
-      {outcome, Code.get_compiler_option(:warnings_as_errors)}
-    else
-      {{:ok, _, [_ | _] = warnings}, true} ->
-        message = "Compilation failed due to warnings while using the --warnings-as-errors option"
-        IO.puts(:stderr, message)
-        {:error, warnings, []}
-
-      {{:ok, outcome, warnings}, _} ->
-        beam_timestamp = Keyword.get(options, :beam_timestamp)
-        {:ok, write_module_binaries(outcome, output, beam_timestamp), warnings}
-
-      {{:error, errors, warnings}, true} ->
-        {:error, errors ++ warnings, []}
-
-      {{:error, errors, warnings}, _} ->
-        {:error, errors, warnings}
-    after
-      Module.ParallelChecker.stop(checker)
-    end
-  end
-
-  defp spawn_workers(schedulers, checker, files, output, options) do
+    beam_timestamp = Keyword.get(options, :beam_timestamp)
     threshold = Keyword.get(options, :long_compilation_threshold, 10) * 1000
     timer_ref = Process.send_after(self(), :threshold_check, threshold)
 
@@ -211,8 +161,7 @@ defmodule Kernel.ParallelCompiler do
         output: output,
         timer_ref: timer_ref,
         long_compilation_threshold: threshold,
-        schedulers: schedulers,
-        checker: checker
+        schedulers: schedulers
       })
 
     Process.cancel_timer(state.timer_ref)
@@ -223,7 +172,21 @@ defmodule Kernel.ParallelCompiler do
       0 -> :ok
     end
 
-    outcome
+    case {outcome, Code.get_compiler_option(:warnings_as_errors)} do
+      {{:ok, _, [_ | _] = warnings}, true} ->
+        message = "Compilation failed due to warnings while using the --warnings-as-errors option"
+        IO.puts(:stderr, message)
+        {:error, warnings, []}
+
+      {{:ok, outcome, warnings}, _} ->
+        {:ok, write_module_binaries(outcome, output, beam_timestamp), warnings}
+
+      {{:error, errors, warnings}, true} ->
+        {:error, errors ++ warnings, []}
+
+      {{:error, errors, warnings}, _} ->
+        {:error, errors, warnings}
+    end
   end
 
   defp each_file(fun) when is_function(fun, 1), do: fn file, _ -> fun.(file) end
@@ -241,7 +204,7 @@ defmodule Kernel.ParallelCompiler do
 
   defp write_module_binaries(result, {:compile, path}, timestamp) do
     Enum.flat_map(result, fn
-      {{:module, module}, binary} ->
+      {{:module, module}, {binary, _map}} ->
         full_path = Path.join(path, Atom.to_string(module) <> ".beam")
         File.write!(full_path, binary)
         if timestamp, do: File.touch!(full_path, timestamp)
@@ -265,21 +228,32 @@ defmodule Kernel.ParallelCompiler do
   end
 
   defp maybe_check_modules(result, runtime_modules, state) do
-    %{profile: profile, checker: checker} = state
+    %{schedulers: schedulers, profile: profile} = state
 
-    compiled_modules =
-      for {{:module, module}, _} <- result,
-          do: module
+    if :elixir_config.get(:bootstrap) do
+      []
+    else
+      compiled_modules = checker_compiled_modules(result)
+      runtime_modules = checker_runtime_modules(runtime_modules)
 
-    runtime_modules =
-      for module <- runtime_modules,
-          path = :code.which(module),
-          is_list(path) and path != [],
-          do: {module, path}
+      profile_checker(profile, compiled_modules, runtime_modules, fn ->
+        Module.ParallelChecker.verify(compiled_modules, runtime_modules, schedulers)
+      end)
+    end
+  end
 
-    profile_checker(profile, compiled_modules, runtime_modules, fn ->
-      Module.ParallelChecker.verify(checker, runtime_modules)
-    end)
+  defp checker_compiled_modules(result) do
+    for {{:module, _module}, {binary, module_map}} <- result do
+      {module_map, binary}
+    end
+  end
+
+  defp checker_runtime_modules(modules) do
+    for module <- modules,
+        path = :code.which(module),
+        is_list(path) and path != [] do
+      {module, File.read!(path)}
+    end
   end
 
   defp profile_init(:time), do: {:time, System.monotonic_time(), 0}
@@ -317,9 +291,9 @@ defmodule Kernel.ParallelCompiler do
   defp spawn_workers([{ref, found} | t], spawned, waiting, files, result, warnings, state) do
     {files, waiting} =
       case List.keytake(waiting, ref, 2) do
-        {{_kind, pid, ^ref, file_pid, _on, _defining, _deadlock}, waiting} ->
+        {{_kind, pid, ^ref, _on, _defining, _deadlock}, waiting} ->
           send(pid, {ref, found})
-          {update_timing(files, file_pid, :waiting), waiting}
+          {update_timing(files, pid, :waiting), waiting}
 
         nil ->
           # In case the waiting process died (for example, it was an async process),
@@ -331,14 +305,13 @@ defmodule Kernel.ParallelCompiler do
   end
 
   defp spawn_workers([file | queue], spawned, waiting, files, result, warnings, state) do
-    %{output: output, dest: dest, checker: checker} = state
+    %{output: output, dest: dest} = state
     parent = self()
     file = Path.expand(file)
 
     {pid, ref} =
       :erlang.spawn_monitor(fn ->
-        Module.ParallelChecker.put(parent, checker)
-        :erlang.put(:elixir_compiler_info, {parent, self()})
+        :erlang.put(:elixir_compiler_pid, parent)
         :erlang.put(:elixir_compiler_file, file)
 
         try do
@@ -392,7 +365,7 @@ defmodule Kernel.ParallelCompiler do
   defp spawn_workers(
          [],
          1,
-         [{_, pid, ref, _, _, _, _}] = waiting,
+         [{_, pid, ref, _, _, _}] = waiting,
          [%{pid: pid}] = files,
          result,
          warnings,
@@ -479,45 +452,37 @@ defmodule Kernel.ParallelCompiler do
     Enum.count(result, &match?({{:module, _}, _}, &1))
   end
 
+  # TODO: Deprecate other returns on v1.14
   defp each_cycle_return({kind, modules, warnings}), do: {kind, modules, warnings}
-
-  defp each_cycle_return(other) do
-    IO.warn(
-      "the :each_cycle callback must return a tuple of format {:compile | :runtime, modules, warnings}"
-    )
-
-    case other do
-      {kind, modules} -> {kind, modules, []}
-      modules when is_list(modules) -> {:compile, modules, []}
-    end
-  end
+  defp each_cycle_return({kind, modules}), do: {kind, modules, []}
+  defp each_cycle_return(modules) when is_list(modules), do: {:compile, modules, []}
 
   # The goal of this function is to find leaves in the dependency graph,
   # i.e. to find code that depends on code that we know is not being defined.
-  # Note that not all files have been compiled yet, so they may not be in waiting.
+  # Note that not all files have been compile yet, so they may not be in waiting.
   defp without_definition(waiting, files) do
-    nilify_empty(
+    nillify_empty(
       for %{pid: pid} <- files,
-          {_, _, ref, ^pid, on, _, _} <- waiting,
+          {_, ^pid, ref, on, _, _} <- List.wrap(List.keyfind(waiting, pid, 1)),
           not defining?(on, waiting),
           do: {ref, :not_found}
     )
   end
 
   defp deadlocked(waiting, type, defining?) do
-    nilify_empty(
-      for {_, _, ref, _, on, _, ^type} <- waiting,
+    nillify_empty(
+      for {_, _, ref, on, _, ^type} <- waiting,
           defining?(on, waiting) == defining?,
           do: {ref, :deadlock}
     )
   end
 
   defp defining?(on, waiting) do
-    Enum.any?(waiting, fn {_, _, _, _, _, defining, _} -> on in defining end)
+    Enum.any?(waiting, fn {_, _, _, _, defining, _} -> on in defining end)
   end
 
-  defp nilify_empty([]), do: nil
-  defp nilify_empty([_ | _] = list), do: list
+  defp nillify_empty([]), do: nil
+  defp nillify_empty([_ | _] = list), do: list
 
   # Wait for messages from child processes
   defp wait_for_messages(queue, spawned, waiting, files, result, warnings, state) do
@@ -530,41 +495,41 @@ defmodule Kernel.ParallelCompiler do
 
       {:available, kind, module} ->
         available =
-          for {^kind, _, ref, _, ^module, _defining, _deadlock} <- waiting,
+          for {^kind, _, ref, ^module, _defining, _deadlock} <- waiting,
               do: {ref, :found}
 
         result = Map.put(result, {kind, module}, true)
         spawn_workers(available ++ queue, spawned, waiting, files, result, warnings, state)
 
-      {:module_available, child, ref, file, module, binary} ->
+      {:module_available, child, ref, file, module, binary, module_map} ->
         state.each_module.(file, module, binary)
 
         # Release the module loader which is waiting for an ack
         send(child, {ref, :ack})
 
         available =
-          for {:module, _, ref, _, ^module, _defining, _deadlock} <- waiting,
+          for {:module, _, ref, ^module, _defining, _deadlock} <- waiting,
               do: {ref, :found}
 
-        result = Map.put(result, {:module, module}, binary)
+        result = Map.put(result, {:module, module}, {binary, module_map})
         spawn_workers(available ++ queue, spawned, waiting, files, result, warnings, state)
 
       # If we are simply requiring files, we do not add to waiting.
-      {:waiting, _kind, child, ref, _file_pid, _on, _defining, _deadlock} when output == :require ->
+      {:waiting, _kind, child, ref, _on, _defining, _deadlock} when output == :require ->
         send(child, {ref, :not_found})
         spawn_workers(queue, spawned, waiting, files, result, warnings, state)
 
-      {:waiting, kind, child_pid, ref, file_pid, on, defining, deadlock?} ->
+      {:waiting, kind, child, ref, on, defining, deadlock?} ->
         # If we already got what we were waiting for, do not put it on waiting.
         # If we're waiting on ourselves, send :found so that we can crash with
         # a better error.
         {files, waiting} =
           if Map.has_key?(result, {kind, on}) or on in defining do
-            send(child_pid, {ref, :found})
+            send(child, {ref, :found})
             {files, waiting}
           else
-            files = update_timing(files, file_pid, :compiling)
-            {files, [{kind, child_pid, ref, file_pid, on, defining, deadlock?} | waiting]}
+            files = update_timing(files, child, :compiling)
+            {files, [{kind, child, ref, on, defining, deadlock?} | waiting]}
           end
 
         spawn_workers(queue, spawned, waiting, files, result, warnings, state)
@@ -585,10 +550,10 @@ defmodule Kernel.ParallelCompiler do
         state = %{state | timer_ref: timer_ref}
         spawn_workers(queue, spawned, waiting, files, result, warnings, state)
 
-      {:warning, file, location, message} ->
+      {:warning, file, line, message} ->
         file = file && Path.absname(file)
         message = :unicode.characters_to_binary(message)
-        warning = {file, location, message}
+        warning = {file, line, message}
         wait_for_messages(queue, spawned, waiting, files, result, [warning | warnings], state)
 
       {:file_ok, child_pid, ref, file, lexical} ->
@@ -710,7 +675,7 @@ defmodule Kernel.ParallelCompiler do
         {:current_stacktrace, stacktrace} = Process.info(pid, :current_stacktrace)
         Process.exit(pid, :kill)
 
-        {kind, ^pid, _, _, on, _, _} = List.keyfind(waiting, pid, 1)
+        {kind, ^pid, _, on, _, _} = List.keyfind(waiting, pid, 1)
         description = "deadlocked waiting on #{kind} #{inspect(on)}"
         error = CompileError.exception(description: description, file: nil, line: nil)
         print_error(file, :error, error, stacktrace)
@@ -757,12 +722,7 @@ defmodule Kernel.ParallelCompiler do
     line = get_line(file, reason, stack)
     file = Path.absname(file)
     message = :unicode.characters_to_binary(Kernel.CLI.format_error(kind, reason, stack))
-    {file, line || 0, message}
-  end
-
-  defp get_line(_file, %{line: line, column: column}, _stack)
-       when is_integer(line) and line > 0 and is_integer(column) and column >= 0 do
-    {line, column}
+    {file, line, message}
   end
 
   defp get_line(_file, %{line: line}, _stack) when is_integer(line) and line > 0 do
@@ -775,8 +735,7 @@ defmodule Kernel.ParallelCompiler do
     end
   end
 
-  defp get_line(file, _reason, [{_, _, _, [file: expanding]}, {_, _, _, info} | _])
-       when expanding in ['expanding macro', 'expanding struct'] do
+  defp get_line(file, _reason, [{_, _, _, [file: 'expanding macro']}, {_, _, _, info} | _]) do
     if Keyword.get(info, :file) == to_charlist(Path.relative_to_cwd(file)) do
       Keyword.get(info, :line)
     end

lib/elixir/lib/kernel/special_forms.ex

@@ -182,7 +182,7 @@ defmodule Kernel.SpecialForms do
       <<1, 2, 3>>
 
   Elixir also accepts by default the segment to be a literal
-  string which expands to integers:
+  string or a literal charlist, which are by default expanded to integers:
 
       iex> <<0, "foo">>
       <<0, 102, 111, 111>>
@@ -246,20 +246,20 @@ defmodule Kernel.SpecialForms do
       iex> {name, species}
       {"Frank", "Walrus"}
 
-  The size can be a variable or any valid guard expression:
+  The size can be a variable:
 
       iex> name_size = 5
       iex> <<name::binary-size(name_size), " the ", species::binary>> = <<"Frank the Walrus">>
       iex> {name, species}
       {"Frank", "Walrus"}
 
-  The size can access prior variables defined in the binary itself:
+  And the variable can be defined in the match itself (prior to its use):
 
       iex> <<name_size::size(8), name::binary-size(name_size), " the ", species::binary>> = <<5, "Frank the Walrus">>
       iex> {name, species}
       {"Frank", "Walrus"}
 
-  However, it cannot access variables defined in the match outside of the binary/bitstring:
+  However, the size cannot be defined in the match outside the binary/bitstring match:
 
       {name_size, <<name::binary-size(name_size), _rest::binary>>} = {5, <<"Frank the Walrus">>}
       ** (CompileError): undefined variable "name_size" in bitstring segment
@@ -366,7 +366,7 @@ defmodule Kernel.SpecialForms do
 
   To learn more about specific optimizations and performance considerations,
   check out the
-  ["Constructing and matching binaries" chapter of the Erlang's Efficiency Guide](https://www.erlang.org/doc/efficiency_guide/binaryhandling.html).
+  ["Constructing and matching binaries" chapter of the Erlang's Efficiency Guide](https://erlang.org/doc/efficiency_guide/binaryhandling.html).
   """
   defmacro unquote(:<<>>)(args), do: error!([args])
 
@@ -604,12 +604,11 @@ defmodule Kernel.SpecialForms do
 
       import List
 
-  A developer can filter to import only functions, macros, or sigils
-  (which can be functions or macros) via the `:only` option:
+  A developer can filter to import only macros or functions via
+  the only option:
 
       import List, only: :functions
       import List, only: :macros
-      import Kernel, only: :sigils
 
   Alternatively, Elixir allows a developer to pass pairs of
   name/arities to `:only` or `:except` as a fine grained control
@@ -779,7 +778,7 @@ defmodule Kernel.SpecialForms do
 
       <<int::integer-little, rest::bits>> = bits
 
-  Read the documentation on the [Typespecs page](typespecs.md) and
+  Read the documentation on the `Typespec` page and
   `<<>>/1` for more information on typespecs and
   bitstrings respectively.
   """
@@ -1212,12 +1211,6 @@ defmodule Kernel.SpecialForms do
   reported to where `defadd` was invoked. `location: :keep` affects
   only definitions inside the quote.
 
-  > **Important:** do not use location: :keep if the function definition
-  > also `unquote`s some of the macro arguments. If you do so, Elixir
-  > will store the file definition of the current location but the
-  > unquoted arguments may contain line information of the macro caller,
-  > leading to erroneous stacktraces.
-
   ## Binding and unquote fragments
 
   Elixir quote/unquote mechanisms provide a functionality called
@@ -1316,13 +1309,11 @@ defmodule Kernel.SpecialForms do
         sum(1, value, 3)
       end
 
-
-  Which the argument for the `:sum` function call is not the
-  expected result:
+  Which would then return:
 
       {:sum, [], [1, {:value, [], Elixir}, 3]}
 
-  For this, we use `unquote`:
+  Which is not the expected result. For this, we use `unquote`:
 
       iex> value =
       ...>   quote do
@@ -1389,10 +1380,6 @@ defmodule Kernel.SpecialForms do
       iex> for n <- [1, 2, 3, 4, 5, 6], rem(n, 2) == 0, do: n
       [2, 4, 6]
 
-  Filters must evaluate to truthy values (everything but `nil`
-  and `false`). If a filter is falsy, then the current value is
-  discarded.
-
   Generators can also be used to filter as it removes any value
   that doesn't match the pattern on the left side of `<-`:
 
@@ -1413,35 +1400,6 @@ defmodule Kernel.SpecialForms do
   filters or inside the block, are not reflected outside of the
   comprehension.
 
-  Variable assignments inside filters must still return a truthy value,
-  otherwise values are discarded. Let's see an example. Imagine you have
-  a keyword list where the key is a programming language and the value
-  is its direct parent. Then let's try to compute the grandparent of each
-  language. You could try this:
-
-      iex> languages = [elixir: :erlang, erlang: :prolog, prolog: nil]
-      iex> for {language, parent} <- languages, grandparent = languages[parent], do: {language, grandparent}
-      [elixir: :prolog]
-
-  Given the grandparents of Erlang and Prolog were nil, those values were
-  filtered out. If you don't want this behaviour, a simple option is to
-  move the filter inside the do-block:
-
-      iex> languages = [elixir: :erlang, erlang: :prolog, prolog: nil]
-      iex> for {language, parent} <- languages do
-      ...>   grandparent = languages[parent]
-      ...>   {language, grandparent}
-      ...> end
-      [elixir: :prolog, erlang: nil, prolog: nil]
-
-  However, such option is not always available, as you may have further
-  filters. An alternative is to convert the filter into a generator by
-  wrapping the right side of `=` in a list:
-
-      iex> languages = [elixir: :erlang, erlang: :prolog, prolog: nil]
-      iex> for {language, parent} <- languages, grandparent <- [languages[parent]], do: {language, grandparent}
-      [elixir: :prolog, erlang: nil, prolog: nil]
-
   ## The `:into` and `:uniq` options
 
   In the examples above, the result returned by the comprehension was
@@ -1561,15 +1519,15 @@ defmodule Kernel.SpecialForms do
       iex> width
       nil
 
-  The behaviour of any expression in a clause is the same as if it was
-  written outside of `with`. For example, `=` will raise a `MatchError`
-  instead of returning the non-matched value:
+  The behaviour of any expression in a clause is the same as outside.
+  For example, `=` will raise a `MatchError` instead of returning the
+  non-matched value:
 
       with :foo = :bar, do: :ok
       ** (MatchError) no match of right hand side value: :bar
 
   As with any other function or macro call in Elixir, explicit parens can
-  also be used around the arguments before the `do`-`end` block:
+  also be used around the arguments before the `do`/`end` block:
 
       iex> opts = %{width: 10, height: 15}
       iex> with(
@@ -1582,8 +1540,6 @@ defmodule Kernel.SpecialForms do
 
   The choice between parens and no parens is a matter of preference.
 
-  ## Else clauses
-
   An `else` option can be given to modify what is being returned from
   `with` in the case of a failed match:
 
@@ -1606,48 +1562,6 @@ defmodule Kernel.SpecialForms do
 
   If an `else` block is used and there are no matching clauses, a `WithClauseError`
   exception is raised.
-
-  ### Beware!
-
-  Keep in mind that, one of potential drawback of `with` is that all
-  failure clauses are flattened into a single `else` block. For example,
-  take this code that checks if a given path points to an Elixir file
-  and that it exists before creating a backup copy:
-
-      with ".ex" <- Path.extname(path),
-           true <- File.exists?(path) do
-        backup_path = path <> ".backup"
-        File.cp!(path, backup_path)
-        {:ok, backup_path}
-      else
-        binary when is_binary(binary) ->
-          {:error, :invalid_extension}
-
-        false ->
-          {:error, :missing_file}
-      end
-
-  Note how we are having to reconstruct the result types of `Path.extname/1`
-  and `File.exists?/1` to build error messages. In this case, it is better
-  to change the with clauses to already return the desired format, like this:
-
-      with :ok <- validate_extension(path),
-           :ok <- validate_exists(path) do
-        backup_path = path <> ".backup"
-        File.cp!(path, backup_path)
-        {:ok, backup_path}
-      end
-
-      defp validate_extension(path) do
-        if Path.extname(path) == ".ex", do: :ok, else: {:error, :invalid_extension}
-      end
-
-      defp validate_exists(path) do
-        if File.exists?(path), do: :ok, else: {:error, :missing_file}
-      end
-
-  Note how the code above is better organized and clearer once we
-  make sure each clause in `with` returns a normalized format.
   """
   defmacro with(args), do: error!([args])
 
@@ -2093,25 +2007,6 @@ defmodule Kernel.SpecialForms do
         File.rm("tmp/story.txt")
       end
 
-  Although `after` clauses are invoked whether or not there was an error, they do not
-  modify the return value. All of the following examples return `:return_me`:
-
-      try do
-        :return_me
-      after
-        IO.puts("I will be printed")
-        :not_returned
-      end
-
-      try do
-        raise "boom"
-      rescue
-        _ -> :return_me
-      after
-        IO.puts("I will be printed")
-        :not_returned
-      end
-
   ## `else` clauses
 
   `else` clauses allow the result of the body passed to `try/1` to be pattern

lib/elixir/lib/kernel/typespec.ex

@@ -104,7 +104,7 @@ defmodule Kernel.Typespec do
   @doc """
   Defines a typespec.
 
-  Invoked by `@/1` expansion.
+  Invoked by `Kernel.@/1` expansion.
   """
   def deftypespec(:spec, expr, _line, _file, module, pos) do
     {_set, bag} = :elixir_module.data_tables(module)
@@ -194,14 +194,14 @@ defmodule Kernel.Typespec do
 
   defp get_doc_info(set, attr, line) do
     case :ets.take(set, attr) do
-      [{^attr, {line, doc}, _, _}] -> {line, doc}
+      [{^attr, {line, doc}, _}] -> {line, doc}
       [] -> {line, nil}
     end
   end
 
   defp get_doc_meta(spec_meta, doc_kind, set) do
     case :ets.take(set, {doc_kind, :meta}) do
-      [{{^doc_kind, :meta}, metadata}] -> Map.merge(metadata, spec_meta)
+      [{{^doc_kind, :meta}, metadata, _}] -> Map.merge(metadata, spec_meta)
       [] -> spec_meta
     end
   end
@@ -553,7 +553,9 @@ defmodule Kernel.Typespec do
   end
 
   defp typespec({:%, _, [name, {:%{}, meta, fields}]}, vars, caller, state) do
-    module = Macro.expand(name, %{caller | function: {:__info__, 1}})
+    # We cannot set a function name to avoid tracking
+    # as a compile time dependency, because for structs it actually is one.
+    module = Macro.expand(name, caller)
 
     struct =
       module
@@ -567,10 +569,7 @@ defmodule Kernel.Typespec do
 
     types =
       :lists.map(
-        fn
-          {:__exception__ = field, true} -> {field, Keyword.get(fields, field, true)}
-          {field, _} -> {field, Keyword.get(fields, field, quote(do: term()))}
-        end,
+        fn {field, _} -> {field, Keyword.get(fields, field, quote(do: term()))} end,
         :lists.sort(struct)
       )
 
@@ -578,7 +577,7 @@ defmodule Kernel.Typespec do
       unless Keyword.has_key?(struct, field) do
         compile_error(
           caller,
-          "undefined field #{inspect(field)} on struct #{inspect(module)}"
+          "undefined field #{inspect(field)} on struct #{Macro.to_string(name)}"
         )
       end
     end
@@ -681,20 +680,10 @@ defmodule Kernel.Typespec do
     end
   end
 
-  defp typespec({:"::", meta, [left, right]}, vars, caller, state) do
+  defp typespec({:"::", meta, [left, right]} = expr, vars, caller, state) do
     message =
-      "invalid type annotation. The left side of :: must be a variable, got: #{Macro.to_string(left)}"
-
-    message =
-      case left do
-        {:|, _, _} ->
-          message <>
-            ". Note \"left | right :: ann\" is the same as \"(left | right) :: ann\". " <>
-            "To solve this, use parentheses around the union operands: \"left | (right :: ann)\""
-
-        _ ->
-          message
-      end
+      "invalid type annotation. When using the | operator to represent the union of types, " <>
+        "make sure to wrap type annotations in parentheses: #{Macro.to_string(expr)}"
 
     # TODO: Make this an error on v2.0, and remove the code below and
     # the :undefined_type_error_enabled? key from the state

lib/elixir/lib/kernel/utils.ex

@@ -22,52 +22,16 @@ defmodule Kernel.Utils do
   defp destructure_nil(count), do: [nil | destructure_nil(count - 1)]
 
   @doc """
-  Callback for defdelegate entry point.
+  Callback for defdelegate.
   """
-  def defdelegate_all(funs, opts, env) do
-    to = Keyword.get(opts, :to) || raise ArgumentError, "expected to: to be given as argument"
-    as = Keyword.get(opts, :as)
-
-    if to == env.module and is_nil(as) do
-      raise ArgumentError,
-            "defdelegate function is calling itself, which will lead to an infinite loop. You should either change the value of the :to option or specify the :as option"
-    end
-
-    if is_list(funs) do
-      IO.warn(
-        "passing a list to Kernel.defdelegate/2 is deprecated, please define each delegate separately",
-        Macro.Env.stacktrace(env)
-      )
-    end
-
-    if Keyword.has_key?(opts, :append_first) do
-      IO.warn(
-        "Kernel.defdelegate/2 :append_first option is deprecated",
-        Macro.Env.stacktrace(env)
-      )
-    end
-
-    to
-  end
-
-  @doc """
-  Callback for each function in defdelegate.
-  """
-  def defdelegate_each(fun, opts) when is_list(opts) do
+  def defdelegate(fun, opts) when is_list(opts) do
     # TODO: Remove on v2.0
     append_first? = Keyword.get(opts, :append_first, false)
 
     {name, args} =
-      case fun do
-        {:when, _, [_left, right]} ->
-          raise ArgumentError,
-                "guards are not allowed in defdelegate/2, got: when #{Macro.to_string(right)}"
-
-        _ ->
-          case Macro.decompose_call(fun) do
-            {_, _} = pair -> pair
-            _ -> raise ArgumentError, "invalid syntax in defdelegate #{Macro.to_string(fun)}"
-          end
+      case Macro.decompose_call(fun) do
+        {_, _} = pair -> pair
+        _ -> raise ArgumentError, "invalid syntax in defdelegate #{Macro.to_string(fun)}"
       end
 
     as = Keyword.get(opts, :as, name)
@@ -100,15 +64,7 @@ defmodule Kernel.Utils do
   @doc """
   Callback for defstruct.
   """
-  def defstruct(module, fields, bootstrapped?) do
-    {set, bag} = :elixir_module.data_tables(module)
-
-    if :ets.member(set, :__struct__) do
-      raise ArgumentError,
-            "defstruct has already been called for " <>
-              "#{Kernel.inspect(module)}, defstruct can only be called once per module"
-    end
-
+  def defstruct(module, fields) do
     case fields do
       fs when is_list(fs) ->
         :ok
@@ -120,7 +76,7 @@ defmodule Kernel.Utils do
     mapper = fn
       {key, val} when is_atom(key) ->
         try do
-          :elixir_quote.escape(val, false, :none)
+          Macro.escape(val)
         rescue
           e in [ArgumentError] ->
             raise ArgumentError, "invalid value for struct field #{key}, " <> Exception.message(e)
@@ -136,20 +92,7 @@ defmodule Kernel.Utils do
     end
 
     fields = :lists.map(mapper, fields)
-
-    enforce_keys =
-      case :ets.lookup(set, :enforce_keys) do
-        [{_, enforce_keys, _, _}] when is_list(enforce_keys) ->
-          :ets.update_element(set, :enforce_keys, {3, :used})
-          enforce_keys
-
-        [{_, enforce_key, _, _}] ->
-          :ets.update_element(set, :enforce_keys, {3, :used})
-          [enforce_key]
-
-        [] ->
-          []
-      end
+    enforce_keys = List.wrap(Module.get_attribute(module, :enforce_keys))
 
     # TODO: Make it raise on v2.0
     warn_on_duplicate_struct_key(:lists.keysort(1, fields))
@@ -163,62 +106,12 @@ defmodule Kernel.Utils do
     end
 
     :lists.foreach(foreach, enforce_keys)
+
     struct = :maps.put(:__struct__, module, :maps.from_list(fields))
 
-    body =
-      case bootstrapped? do
-        true ->
-          case enforce_keys do
-            [] ->
-              quote do
-                Enum.reduce(kv, @__struct__, fn {key, val}, map ->
-                  %{map | key => val}
-                end)
-              end
-
-            _ ->
-              quote do
-                {map, keys} =
-                  Enum.reduce(kv, {@__struct__, unquote(enforce_keys)}, fn
-                    {key, val}, {map, keys} ->
-                      {%{map | key => val}, List.delete(keys, key)}
-                  end)
-
-                case keys do
-                  [] ->
-                    map
-
-                  _ ->
-                    raise ArgumentError,
-                          "the following keys must also be given when building " <>
-                            "struct #{inspect(__MODULE__)}: #{inspect(keys)}"
-                end
-              end
-          end
-
-        false ->
-          quote do
-            :lists.foldl(
-              fn {key, val}, acc -> %{acc | key => val} end,
-              @__struct__,
-              kv
-            )
-          end
-      end
-
     case enforce_keys -- :maps.keys(struct) do
       [] ->
-        # The __struct__ field is used for expansion and for loading remote structs
-        :ets.insert(set, {:__struct__, struct, nil, []})
-
-        # Store all field metadata to go into __info__(:struct)
-        mapper = fn {key, val} ->
-          %{field: key, default: val, required: :lists.member(key, enforce_keys)}
-        end
-
-        :ets.insert(set, {{:elixir, :struct}, :lists.map(mapper, fields)})
-        derive = :lists.map(fn {_, value} -> value end, :ets.take(bag, {:accumulate, :derive}))
-        {struct, :lists.reverse(derive), quote(do: kv), body}
+        {struct, enforce_keys, Module.get_attribute(module, :derive)}
 
       error_keys ->
         raise ArgumentError,
@@ -244,9 +137,9 @@ defmodule Kernel.Utils do
   Announcing callback for defstruct.
   """
   def announce_struct(module) do
-    case :erlang.get(:elixir_compiler_info) do
+    case :erlang.get(:elixir_compiler_pid) do
       :undefined -> :ok
-      {pid, _} -> send(pid, {:available, :struct, module})
+      pid -> send(pid, {:available, :struct, module})
     end
   end
 
@@ -326,7 +219,7 @@ defmodule Kernel.Utils do
   def defguard(args, expr, env) do
     {^args, vars} = extract_refs_from_args(args)
     env = :elixir_env.with_vars(%{env | context: :guard}, vars)
-    {expr, _, _} = :elixir_expand.expand(expr, :elixir_env.env_to_ex(env), env)
+    {expr, _scope} = :elixir_expand.expand(expr, env)
 
     quote do
       case Macro.Env.in_guard?(__CALLER__) do
@@ -375,7 +268,7 @@ defmodule Kernel.Utils do
 
                 %{} ->
                   generated = String.to_atom("arg" <> Integer.to_string(map_size(acc) + 1))
-                  new_var = Macro.unique_var(generated, Elixir)
+                  new_var = Macro.var(generated, Elixir)
                   {new_var, Map.put(acc, pair, {new_var, var})}
               end
 

lib/elixir/lib/keyword.ex

@@ -13,43 +13,45 @@ defmodule Keyword do
 
       [{:exit_on_close, true}, {:active, :once}, {:packet_size, 1024}]
 
-  Elixir provides a special and more concise syntax for keyword lists:
+  Elixir provides a special and more concise syntax for keyword lists
+  that looks like this:
 
       [exit_on_close: true, active: :once, packet_size: 1024]
 
-  The two syntaxes return the exact same value.
-
-  A *key* can be any atom, consisting of Unicode letters, numbers,
-  an underscore or the `@` sign. If the *key* should have any other
-  characters, such as spaces, you can wrap it in quotes:
+  The two syntaxes are completely equivalent. Like atoms, keyword
+  lists keys must be composed of Unicode characters such as letters,
+  numbers, underscore, and `@`. If the keyword has a character that
+  does not belong to the category above, such as spaces, you can wrap
+  it in quotes:
 
       iex> ["exit on close": true]
       ["exit on close": true]
 
-  Wrapping an atom in quotes does not make it a string. Keyword list
-  *keys* are always atoms. Quotes should only be used when necessary
-  or Elixir will issue a warning.
+  Wrapping a keyword in quotes does not make it a string. Keyword lists
+  keys are always atoms. If you use quotes around the key when quoting
+  is not necessary, Elixir will warn.
 
   ## Duplicate keys and ordering
 
-  A keyword may have duplicate keys so it is not strictly a key-value
-  data type. However most of the functions in this module work on a
-  key-value structure and behave similar to the functions you would
-  find in the `Map` module. For example, `Keyword.get/3` will get the first
-  entry matching the given key, regardless if duplicate entries exist.
-  Similarly, `Keyword.put/3` and `Keyword.delete/2` ensure all duplicate
+  A keyword may have duplicated keys so it is not strictly a key-value
+  data type. However most of the functions in this module behave exactly
+  as a key-value so they work similarly to the functions you would find
+  in the `Map` module. For example, `Keyword.get/3` will get the first
+  entry matching the given key, regardless if duplicated entries exist.
+  Similarly, `Keyword.put/3` and `Keyword.delete/2` ensure all duplicated
   entries for a given key are removed when invoked. Note, however, that
   keyword list operations need to traverse the whole list in order to find
   keys, so these operations are slower than their map counterparts.
 
-  A handful of functions exist to handle duplicate keys, for example,
+  A handful of functions exist to handle duplicated keys, for example,
   `get_values/2` returns all values for a given key and `delete_first/2`
-  deletes just the first entry of the existing ones.
+  deletes just one of the existing entries.
 
-  Even though lists preserve the existing order, the functions in
+  Even though lists preserve the user ordering, the functions in
   `Keyword` do not guarantee any ordering. For example, if you invoke
-  `Keyword.put(opts, new_key, new_value)`, there is no guarantee for
-  where `new_key` will be added to (the front, the end or anywhere else).
+  `Keyword.put(opts, new_key, new_value)`, there is no guarantee to
+  where `new_key` will be added (to the front, to the end, or
+  anywhere else).
 
   Given ordering is not guaranteed, it is not recommended to pattern
   match on keyword lists either. For example, a function such as:
@@ -65,7 +67,7 @@ defmodule Keyword do
       my_function([another_key: :bar, some_key: :foo])
 
   Most of the functions in this module work in linear time. This means
-  that the time it takes to perform an operation grows at the same
+  that, the time it takes to perform an operation grows at the same
   rate as the length of the list.
 
   ## Call syntax
@@ -81,8 +83,8 @@ defmodule Keyword do
 
       String.split("1-0", "-", trim: true, parts: 2)
 
-  Since tuples, lists and maps are treated similarly to function
-  arguments in Elixir syntax, this property is also available to them:
+  Since tuples, lists, maps, and others are treated the same as function
+  calls in Elixir syntax, this property is also available to them:
 
       iex> {1, 2, foo: :bar}
       {1, 2, [{:foo, :bar}]}
@@ -92,7 +94,6 @@ defmodule Keyword do
 
       iex> %{1 => 2, foo: :bar}
       %{1 => 2, :foo => :bar}
-
   """
 
   @compile :inline_list_funcs
@@ -104,24 +105,7 @@ defmodule Keyword do
   @type t(value) :: [{key, value}]
 
   @doc """
-  Builds a keyword from the given `keys` and the fixed `value`.
-
-  ## Examples
-
-      iex> Keyword.from_keys([:foo, :bar, :baz], :atom)
-      [foo: :atom, bar: :atom, baz: :atom]
-
-  """
-  @doc since: "1.14.0"
-  @spec from_keys([key], value) :: t(value)
-  def from_keys(keys, value) when is_list(keys) do
-    :lists.map(&{&1, value}, keys)
-  end
-
-  @doc """
-  Returns `true` if `term` is a keyword list, otherwise `false`.
-
-  When `term` is a list it is traversed to the end.
+  Returns `true` if `term` is a keyword list; otherwise returns `false`.
 
   ## Examples
 
@@ -161,7 +145,7 @@ defmodule Keyword do
   @doc """
   Creates a keyword list from an enumerable.
 
-  Removes duplicate entries and the last one prevails.
+  Duplicated entries are removed, the latest one prevails.
   Unlike `Enum.into(enumerable, [])`, `Keyword.new(enumerable)`
   guarantees the keys are unique.
 
@@ -174,7 +158,7 @@ defmodule Keyword do
       [a: 3]
 
   """
-  @spec new(Enumerable.t()) :: t
+  @spec new(Enum.t()) :: t
   def new(pairs) do
     new(pairs, fn pair -> pair end)
   end
@@ -182,7 +166,7 @@ defmodule Keyword do
   @doc """
   Creates a keyword list from an enumerable via the transformation function.
 
-  Removes duplicate entries and the last one prevails.
+  Duplicated entries are removed, the latest one prevails.
   Unlike `Enum.into(enumerable, [], fun)`,
   `Keyword.new(enumerable, fun)` guarantees the keys are unique.
 
@@ -192,7 +176,7 @@ defmodule Keyword do
       [a: :a, b: :b]
 
   """
-  @spec new(Enumerable.t(), (term -> {key, value})) :: t
+  @spec new(Enum.t(), (term -> {key, value})) :: t
   def new(pairs, transform) when is_function(transform, 1) do
     fun = fn el, acc ->
       {k, v} = transform.(el)
@@ -203,166 +187,12 @@ defmodule Keyword do
   end
 
   @doc """
-  Ensures the given `keyword` has only the keys given in `values`.
+  Gets the value for a specific `key`.
 
-  The second argument must be a list of atoms, specifying
-  a given key, or tuples specifying a key and a default value.
+  If `key` does not exist, return the default value
+  (`nil` if no default value).
 
-  If the keyword list has only the given keys, it returns
-  `{:ok, keyword}` with default values applied. Otherwise it
-  returns `{:error, invalid_keys}` with invalid keys.
-
-  See also: `validate!/2`.
-
-  ## Examples
-
-      iex> {:ok, result} = Keyword.validate([], [one: 1, two: 2])
-      iex> Enum.sort(result)
-      [one: 1, two: 2]
-
-      iex> {:ok, result} = Keyword.validate([two: 3], [one: 1, two: 2])
-      iex> Enum.sort(result)
-      [one: 1, two: 3]
-
-  If atoms are given, they are supported as keys but do not
-  provide a default value:
-
-      iex> {:ok, result} = Keyword.validate([], [:one, two: 2])
-      iex> Enum.sort(result)
-      [two: 2]
-
-      iex> {:ok, result} = Keyword.validate([one: 1], [:one, two: 2])
-      iex> Enum.sort(result)
-      [one: 1, two: 2]
-
-  Passing unknown keys returns an error:
-
-      iex> Keyword.validate([three: 3, four: 4], [one: 1, two: 2])
-      {:error, [:four, :three]}
-
-  Passing the same key multiple times also errors:
-
-      iex> Keyword.validate([one: 1, two: 2, one: 1], [:one, :two])
-      {:error, [:one]}
-
-  """
-  @doc since: "1.13.0"
-  @spec validate(keyword(), values :: [atom() | {atom(), term()}]) ::
-          {:ok, keyword()} | {:error, [atom]}
-  def validate(keyword, values) when is_list(keyword) and is_list(values) do
-    validate(keyword, values, [], [], [])
-  end
-
-  defp validate([{key, _} = pair | keyword], values1, values2, acc, bad_keys) when is_atom(key) do
-    case find_key!(key, values1, values2) do
-      {values1, values2} ->
-        validate(keyword, values1, values2, [pair | acc], bad_keys)
-
-      :error ->
-        case find_key!(key, values2, values1) do
-          {values1, values2} ->
-            validate(keyword, values1, values2, [pair | acc], bad_keys)
-
-          :error ->
-            validate(keyword, values1, values2, acc, [key | bad_keys])
-        end
-    end
-  end
-
-  defp validate([], values1, values2, acc, []) do
-    {:ok, move_pairs!(values1, move_pairs!(values2, acc))}
-  end
-
-  defp validate([], _values1, _values2, _acc, bad_keys) do
-    {:error, bad_keys}
-  end
-
-  defp validate([pair | _], _values1, _values2, _acc, []) do
-    raise ArgumentError,
-          "expected a keyword list as first argument, got invalid entry: #{inspect(pair)}"
-  end
-
-  defp find_key!(key, [key | rest], acc), do: {rest, acc}
-  defp find_key!(key, [{key, _} | rest], acc), do: {rest, acc}
-  defp find_key!(key, [head | tail], acc), do: find_key!(key, tail, [head | acc])
-  defp find_key!(_key, [], _acc), do: :error
-
-  defp move_pairs!([key | rest], acc) when is_atom(key),
-    do: move_pairs!(rest, acc)
-
-  defp move_pairs!([{key, _} = pair | rest], acc) when is_atom(key),
-    do: move_pairs!(rest, [pair | acc])
-
-  defp move_pairs!([], acc),
-    do: acc
-
-  defp move_pairs!([other | _], _) do
-    raise ArgumentError,
-          "expected the second argument to be a list of atoms or tuples, got: #{inspect(other)}"
-  end
-
-  @doc """
-  Similar to `validate/2` but returns the keyword or raises an error.
-
-  ## Examples
-
-      iex> Keyword.validate!([], [one: 1, two: 2]) |> Enum.sort()
-      [one: 1, two: 2]
-      iex> Keyword.validate!([two: 3], [one: 1, two: 2]) |> Enum.sort()
-      [one: 1, two: 3]
-
-  If atoms are given, they are supported as keys but do not
-  provide a default value:
-
-      iex> Keyword.validate!([], [:one, two: 2]) |> Enum.sort()
-      [two: 2]
-      iex> Keyword.validate!([one: 1], [:one, two: 2]) |> Enum.sort()
-      [one: 1, two: 2]
-
-  Passing unknown keys raises an error:
-
-      iex> Keyword.validate!([three: 3], [one: 1, two: 2])
-      ** (ArgumentError) unknown keys [:three] in [three: 3], the allowed keys are: [:one, :two]
-
-  Passing the same key multiple times also errors:
-
-      iex> Keyword.validate!([one: 1, two: 2, one: 1], [:one, :two])
-      ** (ArgumentError) duplicate keys [:one] in [one: 1, two: 2, one: 1]
-
-  """
-  @doc since: "1.13.0"
-  @spec validate!(keyword(), values :: [atom() | {atom(), term()}]) :: keyword()
-  def validate!(keyword, values) do
-    case validate(keyword, values) do
-      {:ok, kw} ->
-        kw
-
-      {:error, invalid_keys} ->
-        keys =
-          for value <- values,
-              do: if(is_atom(value), do: value, else: elem(value, 0))
-
-        message =
-          case Enum.split_with(invalid_keys, &(&1 in keys)) do
-            {_, [_ | _] = unknown} ->
-              "unknown keys #{inspect(unknown)} in #{inspect(keyword)}, " <>
-                "the allowed keys are: #{inspect(keys)}"
-
-            {[_ | _] = known, _} ->
-              "duplicate keys #{inspect(known)} in #{inspect(keyword)}"
-          end
-
-        raise ArgumentError, message
-    end
-  end
-
-  @doc """
-  Gets the value under the given `key`.
-
-  Returns the default value if `key` does not exist
-  (`nil` if no default value is provided).
-
-  If duplicate entries exist, it returns the first one.
+  If duplicated entries exist, the first one is returned.
   Use `get_values/2` to retrieve all entries.
 
   ## Examples
@@ -376,7 +206,7 @@ defmodule Keyword do
       iex> Keyword.get([a: 1], :b, 3)
       3
 
-  With duplicate keys:
+  With duplicated keys:
 
       iex> Keyword.get([a: 1, a: 2], :a, 3)
       1
@@ -393,14 +223,14 @@ defmodule Keyword do
   end
 
   @doc """
-  Gets the value under the given `key`.
+  Gets the value for a specific `key`.
 
   If `key` does not exist, lazily evaluates `fun` and returns its result.
 
   This is useful if the default value is very expensive to calculate or
-  generally difficult to set up and tear down again.
+  generally difficult to setup and teardown again.
 
-  If duplicate entries exist, it returns the first one.
+  If duplicated entries exist, the first one is returned.
   Use `get_values/2` to retrieve all entries.
 
   ## Examples
@@ -428,14 +258,14 @@ defmodule Keyword do
   @doc """
   Gets the value from `key` and updates it, all in one pass.
 
-  The `fun` argument receives the value of `key` (or `nil` if `key`
+  This `fun` argument receives the value of `key` (or `nil` if `key`
   is not present) and must return a two-element tuple: the current value
   (the retrieved value, which can be operated on before being returned)
   and the new value to be stored under `key`. The `fun` may also
   return `:pop`, implying the current value shall be removed from the
   keyword list and returned.
 
-  Returns a tuple that contains the current value returned by
+  The returned value is a tuple with the current value returned by
   `fun` and a new keyword list with the updated value under `key`.
 
   ## Examples
@@ -450,11 +280,6 @@ defmodule Keyword do
       ...> end)
       {nil, [b: "new value!", a: 1]}
 
-      iex> Keyword.get_and_update([a: 2], :a, fn number ->
-      ...>   {2 * number, 3 * number}
-      ...> end)
-      {4, [a: 6]}
-
       iex> Keyword.get_and_update([a: 1], :a, fn _ -> :pop end)
       {1, []}
 
@@ -498,15 +323,15 @@ defmodule Keyword do
   end
 
   @doc """
-  Gets the value under `key` and updates it. Raises if there is no `key`.
+  Gets the value from `key` and updates it. Raises if there is no `key`.
 
-  The `fun` argument receives the value under `key` and must return a
+  This `fun` argument receives the value of `key` and must return a
   two-element tuple: the current value (the retrieved value, which can be
   operated on before being returned) and the new value to be stored under
   `key`.
 
-  Returns a tuple that contains the current value returned by
-  `fun` and a new keyword list with the updated value under `key`.
+  The returned value is a tuple with the current value returned by `fun` and a new
+  keyword list with the updated value under `key`.
 
   ## Examples
 
@@ -551,13 +376,13 @@ defmodule Keyword do
   end
 
   defp get_and_update!([], key, _fun, acc) when is_atom(key) do
-    raise KeyError, key: key, term: acc
+    raise(KeyError, key: key, term: acc)
   end
 
   @doc """
   Fetches the value for a specific `key` and returns it in a tuple.
 
-  If the `key` does not exist, it returns `:error`.
+  If the `key` does not exist, returns `:error`.
 
   ## Examples
 
@@ -578,7 +403,7 @@ defmodule Keyword do
   @doc """
   Fetches the value for specific `key`.
 
-  If the `key` does not exist, it raises a `KeyError`.
+  If `key` does not exist, a `KeyError` is raised.
 
   ## Examples
 
@@ -592,12 +417,12 @@ defmodule Keyword do
   def fetch!(keywords, key) when is_list(keywords) and is_atom(key) do
     case :lists.keyfind(key, 1, keywords) do
       {^key, value} -> value
-      false -> raise KeyError, key: key, term: keywords
+      false -> raise(KeyError, key: key, term: keywords)
     end
   end
 
   @doc """
-  Gets all values under a specific `key`.
+  Gets all values for a specific `key`.
 
   ## Examples
 
@@ -621,7 +446,7 @@ defmodule Keyword do
   @doc """
   Returns all keys from the keyword list.
 
-  Keeps duplicate keys in the resulting list of keys.
+  Duplicated keys appear duplicated in the final list of keys.
 
   ## Examples
 
@@ -637,24 +462,26 @@ defmodule Keyword do
   """
   @spec keys(t) :: [key]
   def keys(keywords) when is_list(keywords) do
-    :lists.map(
-      fn
-        {key, _} when is_atom(key) -> key
-        element -> throw(element)
-      end,
-      keywords
-    )
-  catch
-    element ->
-      raise ArgumentError,
-            "expected a keyword list, but an entry in the list is not a two-element tuple " <>
-              "with an atom as its first element, got: #{inspect(element)}"
+    try do
+      :lists.map(
+        fn
+          {key, _} when is_atom(key) -> key
+          element -> throw(element)
+        end,
+        keywords
+      )
+    catch
+      element ->
+        raise ArgumentError,
+              "expected a keyword list, but an entry in the list is not a two-element tuple with an atom as its first element, " <>
+                "got: #{inspect(element)}"
+    end
   end
 
   @doc """
   Returns all values from the keyword list.
 
-  Keeps values from duplicate keys in the resulting list of values.
+  Values from duplicated keys will be kept in the final list of values.
 
   ## Examples
 
@@ -691,11 +518,11 @@ defmodule Keyword do
   end
 
   @doc """
-  Deletes the entries in the keyword list under a specific `key`.
+  Deletes the entries in the keyword list for a specific `key`.
 
-  If the `key` does not exist, it returns the keyword list unchanged.
+  If the `key` does not exist, returns the keyword list unchanged.
   Use `delete_first/2` to delete just the first entry in case of
-  duplicate keys.
+  duplicated keys.
 
   ## Examples
 
@@ -721,9 +548,9 @@ defmodule Keyword do
   defp delete_key([], _key), do: []
 
   @doc """
-  Deletes the first entry in the keyword list under a specific `key`.
+  Deletes the first entry in the keyword list for a specific `key`.
 
-  If the `key` does not exist, it returns the keyword list unchanged.
+  If the `key` does not exist, returns the keyword list unchanged.
 
   ## Examples
 
@@ -754,10 +581,10 @@ defmodule Keyword do
   end
 
   @doc """
-  Puts the given `value` under the specified `key`.
+  Puts the given `value` under `key`.
 
-  If a value under `key` already exists, it overrides the value
-  and removes all duplicate entries.
+  If a previous value is already stored, all entries are
+  removed and the value is overridden.
 
   ## Examples
 
@@ -779,19 +606,19 @@ defmodule Keyword do
   in keyword list unless `key` is already present.
 
   This is useful if the value is very expensive to calculate or
-  generally difficult to set up and tear down again.
+  generally difficult to setup and teardown again.
 
   ## Examples
 
       iex> keyword = [a: 1]
       iex> fun = fn ->
       ...>   # some expensive operation here
-      ...>   13
+      ...>   3
       ...> end
       iex> Keyword.put_new_lazy(keyword, :a, fun)
       [a: 1]
       iex> Keyword.put_new_lazy(keyword, :b, fun)
-      [b: 13, a: 1]
+      [b: 3, a: 1]
 
   """
   @spec put_new_lazy(t, key, (() -> value)) :: t
@@ -804,7 +631,8 @@ defmodule Keyword do
   end
 
   @doc """
-  Puts the given `value` under `key`, unless the entry `key` already exists.
+  Puts the given `value` under `key` unless the entry `key`
+  already exists.
 
   ## Examples
 
@@ -825,8 +653,8 @@ defmodule Keyword do
   @doc """
   Puts a value under `key` only if the `key` already exists in `keywords`.
 
-  In case a key exists multiple times in the keyword list,
-  it removes later occurrences.
+  In the case a value is stored multiple times in the keyword list,
+  later occurrences are removed.
 
   ## Examples
 
@@ -858,7 +686,7 @@ defmodule Keyword do
   @doc """
   Puts a value under `key` only if the `key` already exists in `keywords`.
 
-  If `key` is not present in `keywords`, it raises a `KeyError`.
+  If `key` is not present in `keywords`, a `KeyError` exception is raised.
 
   ## Examples
 
@@ -886,50 +714,13 @@ defmodule Keyword do
   end
 
   defp replace!([], key, _value, original) do
-    raise KeyError, key: key, term: original
+    raise(KeyError, key: key, term: original)
   end
 
-  @doc """
-  Replaces the value under `key` using the given function only if
-  `key` already exists in `keywords`.
-
-  In comparison to `replace/3`, this can be useful when it's expensive to calculate the value.
-
-  If `key` does not exist, the original keyword list is returned unchanged.
-
-  ## Examples
-
-      iex> Keyword.replace_lazy([a: 1, b: 2], :a, fn v -> v * 4 end)
-      [a: 4, b: 2]
-
-      iex> Keyword.replace_lazy([a: 2, b: 2, a: 1], :a, fn v -> v * 4 end)
-      [a: 8, b: 2]
-
-      iex> Keyword.replace_lazy([a: 1, b: 2], :c, fn v -> v * 4 end)
-      [a: 1, b: 2]
-
-  """
-  @doc since: "1.14.0"
-  @spec replace_lazy(t, key, (existing_value :: value -> new_value :: value)) :: t
-  def replace_lazy(keywords, key, fun)
-      when is_list(keywords) and is_atom(key) and is_function(fun, 1) do
-    do_replace_lazy(keywords, key, fun)
-  end
-
-  defp do_replace_lazy([{key, value} | keywords], key, fun) do
-    [{key, fun.(value)} | delete(keywords, key)]
-  end
-
-  defp do_replace_lazy([{_, _} = e | keywords], key, fun) do
-    [e | do_replace_lazy(keywords, key, fun)]
-  end
-
-  defp do_replace_lazy([], _key, _value), do: []
-
   @doc """
   Checks if two keywords are equal.
 
-  Considers two keywords to be equal if they contain
+  Two keywords are considered to be equal if they contain
   the same keys and those keys contain the same values.
 
   ## Examples
@@ -956,10 +747,10 @@ defmodule Keyword do
   @doc """
   Merges two keyword lists into one.
 
-  Adds all keys, including duplicate keys, given in `keywords2`
-  to `keywords1`, overriding any existing ones.
+  All keys, including duplicated keys, given in `keywords2` will be added
+  to `keywords1`, overriding any existing one.
 
-  There are no guarantees about the order of the keys in the returned keyword.
+  There are no guarantees about the order of keys in the returned keyword.
 
   ## Examples
 
@@ -1000,13 +791,13 @@ defmodule Keyword do
   @doc """
   Merges two keyword lists into one.
 
-  Adds all keys, including duplicate keys, given in `keywords2`
-  to `keywords1`. Invokes the given function to solve conflicts.
+  All keys, including duplicated keys, given in `keywords2` will be added
+  to `keywords1`. The given function will be invoked to solve conflicts.
 
-  If `keywords2` has duplicate keys, it invokes the given function
+  If `keywords2` has duplicate keys, the given function will be invoked
   for each matching pair in `keywords1`.
 
-  There are no guarantees about the order of the keys in the returned keyword.
+  There are no guarantees about the order of keys in the returned keyword.
 
   ## Examples
 
@@ -1080,11 +871,12 @@ defmodule Keyword do
   end
 
   @doc """
-  Updates the value under `key` using the given function.
+  Updates the `key` with the given function.
 
-  Raises `KeyError` if the `key` does not exist.
+  If the `key` does not exist, raises `KeyError`.
 
-  Removes all duplicate keys and only updates the first one.
+  If there are duplicated keys, they are all removed and only the first one
+  is updated.
 
   ## Examples
 
@@ -1112,16 +904,18 @@ defmodule Keyword do
   end
 
   defp update!([], key, _fun, original) do
-    raise KeyError, key: key, term: original
+    raise(KeyError, key: key, term: original)
   end
 
   @doc """
-  Updates the value under `key` in `keywords` using the given function.
+  Updates the `key` in `keywords` with the given function.
 
   If the `key` does not exist, it inserts the given `default` value.
-  Does not pass the `default` value through the update function.
 
-  Removes all duplicate keys and only updates the first one.
+  If there are duplicated keys, they are all removed and only the first one
+  is updated.
+
+  The default value will not be passed through the update function.
 
   ## Examples
 
@@ -1154,14 +948,14 @@ defmodule Keyword do
   end
 
   @doc """
-  Takes all entries corresponding to the given `keys` and extracts them into a
+  Takes all entries corresponding to the given keys and extracts them into a
   separate keyword list.
 
   Returns a tuple with the new list and the old list with removed keys.
 
-  Ignores keys for which there are no entries in the keyword list.
+  Keys for which there are no entries in the keyword list are ignored.
 
-  Entries with duplicate keys end up in the same keyword list.
+  Entries with duplicated keys end up in the same keyword list.
 
   ## Examples
 
@@ -1186,10 +980,10 @@ defmodule Keyword do
   end
 
   @doc """
-  Takes all entries corresponding to the given `keys` and returns them as a new
+  Takes all entries corresponding to the given keys and returns them in a new
   keyword list.
 
-  Preserves duplicate keys in the new keyword list.
+  Duplicated keys are preserved in the new keyword list.
 
   ## Examples
 
@@ -1201,18 +995,16 @@ defmodule Keyword do
   """
   @spec take(t, [key]) :: t
   def take(keywords, keys) when is_list(keywords) and is_list(keys) do
-    :lists.filter(fn {k, _} -> :lists.member(k, keys) end, keywords)
+    :lists.filter(fn {k, _} -> k in keys end, keywords)
   end
 
   @doc """
-  Drops the given `keys` from the keyword list.
+  Drops the given keys from the keyword list.
 
-  Removes duplicate keys from the new keyword list.
+  Duplicated keys are preserved in the new keyword list.
 
   ## Examples
 
-      iex> Keyword.drop([a: 1, a: 2], [:a])
-      []
       iex> Keyword.drop([a: 1, b: 2, c: 3], [:b, :d])
       [a: 1, c: 3]
       iex> Keyword.drop([a: 1, b: 2, b: 3, c: 3, a: 5], [:b, :d])
@@ -1221,7 +1013,7 @@ defmodule Keyword do
   """
   @spec drop(t, [key]) :: t
   def drop(keywords, keys) when is_list(keywords) and is_list(keys) do
-    :lists.filter(fn {k, _} -> k not in keys end, keywords)
+    :lists.filter(fn {key, _} -> key not in keys end, keywords)
   end
 
   @doc """
@@ -1229,10 +1021,11 @@ defmodule Keyword do
 
   It returns a tuple where the first element is the first value for `key` and the
   second element is a keyword list with all entries associated with `key` removed.
-  If the `key` is not present in the keyword list, it returns `{default, keyword_list}`.
+  If the `key` is not present in the keyword list, `{default, keyword_list}` is
+  returned.
 
   If you don't want to remove all the entries associated with `key` use `pop_first/3`
-  instead, which will remove only the first entry.
+  instead, that function will remove only the first entry.
 
   ## Examples
 
@@ -1258,7 +1051,7 @@ defmodule Keyword do
   Returns the first value for `key` and removes all associated entries in the keyword list,
   raising if `key` is not present.
 
-  This function behaves like `pop/3`, but raises in case the `key` is not present in the
+  This function behaves like `pop/3`, but raises in cases the `key` is not present in the
   given `keywords`.
 
   ## Examples
@@ -1285,10 +1078,11 @@ defmodule Keyword do
 
   It returns a tuple where the first element is a list of values for `key` and the
   second element is a keyword list with all entries associated with `key` removed.
-  If the `key` is not present in the keyword list, it returns `{[], keyword_list}`.
+  If the `key` is not present in the keyword list, `{[], keyword_list}` is
+  returned.
 
   If you don't want to remove all the entries associated with `key` use `pop_first/3`
-  instead, which will remove only the first entry.
+  instead, that function will remove only the first entry.
 
   ## Examples
 
@@ -1319,9 +1113,10 @@ defmodule Keyword do
   Lazily returns and removes all values associated with `key` in the keyword list.
 
   This is useful if the default value is very expensive to calculate or
-  generally difficult to set up and tear down again.
+  generally difficult to setup and teardown again.
 
-  Removes all duplicate keys. See `pop_first/3` for removing only the first entry.
+  All duplicated keys are removed. See `pop_first/3` for
+  removing only the first entry.
 
   ## Examples
 
@@ -1340,15 +1135,18 @@ defmodule Keyword do
   def pop_lazy(keywords, key, fun)
       when is_list(keywords) and is_atom(key) and is_function(fun, 0) do
     case fetch(keywords, key) do
-      {:ok, value} -> {value, delete(keywords, key)}
-      :error -> {fun.(), keywords}
+      {:ok, value} ->
+        {value, delete(keywords, key)}
+
+      :error ->
+        {fun.(), keywords}
     end
   end
 
   @doc """
   Returns and removes the first value associated with `key` in the keyword list.
 
-  Keeps duplicate keys in the resulting keyword list.
+  Duplicated keys are not removed.
 
   ## Examples
 
@@ -1380,76 +1178,13 @@ defmodule Keyword do
 
   """
   @spec to_list(t) :: t
-  def to_list(keywords) when is_list(keywords) do
-    keywords
+  def to_list(keyword) when is_list(keyword) do
+    keyword
   end
 
   @doc false
   @deprecated "Use Kernel.length/1 instead"
-  def size(keywords) do
-    length(keywords)
-  end
-
-  @doc """
-  Returns a keyword list containing only the entries from `keywords`
-  for which the function `fun` returns a truthy value.
-
-  See also `reject/2` which discards all entries where the function
-  returns a truthy value.
-
-  ## Examples
-
-      iex> Keyword.filter([one: 1, two: 2, three: 3], fn {_key, val} -> rem(val, 2) == 1 end)
-      [one: 1, three: 3]
-
-  """
-  @doc since: "1.13.0"
-  @spec filter(t, ({key, value} -> as_boolean(term))) :: t
-  def filter(keywords, fun) when is_list(keywords) and is_function(fun, 1) do
-    do_filter(keywords, fun)
-  end
-
-  defp do_filter([], _fun), do: []
-
-  defp do_filter([{_, _} = entry | entries], fun) do
-    if fun.(entry) do
-      [entry | do_filter(entries, fun)]
-    else
-      do_filter(entries, fun)
-    end
-  end
-
-  @doc """
-  Returns a keyword list excluding the entries from `keywords`
-  for which the function `fun` returns a truthy value.
-
-  See also `filter/2`.
-
-  ## Examples
-
-      iex> Keyword.reject([one: 1, two: 2, three: 3], fn {_key, val} -> rem(val, 2) == 1 end)
-      [two: 2]
-
-  """
-  @doc since: "1.13.0"
-  @spec reject(t, ({key, value} -> as_boolean(term))) :: t
-  def reject(keywords, fun) when is_list(keywords) and is_function(fun, 1) do
-    do_reject(keywords, fun)
-  end
-
-  defp do_reject([], _fun), do: []
-
-  defp do_reject([{_, _} = entry | entries], fun) do
-    if fun.(entry) do
-      do_reject(entries, fun)
-    else
-      [entry | do_reject(entries, fun)]
-    end
-  end
-
-  @doc false
-  @deprecated "Use Keyword.new/2 instead"
-  def map(keywords, fun) when is_list(keywords) do
-    Enum.map(keywords, fn {k, v} -> {k, fun.({k, v})} end)
+  def size(keyword) do
+    length(keyword)
   end
 end

lib/elixir/lib/list.ex

@@ -8,7 +8,7 @@ defmodule List do
       [1, "two", 3, :four]
 
   Two lists can be concatenated and subtracted using the
-  `++/2` and `--/2` operators:
+  `Kernel.++/2` and `Kernel.--/2` operators:
 
       iex> [1, 2, 3] ++ [4, 5, 6]
       [1, 2, 3, 4, 5, 6]
@@ -230,7 +230,7 @@ defmodule List do
 
   @doc """
   Folds (reduces) the given list from the left with
-  a function. Requires an accumulator, which can be any value.
+  a function. Requires an accumulator.
 
   ## Examples
 
@@ -240,9 +240,6 @@ defmodule List do
       iex> List.foldl([1, 2, 3, 4], 0, fn x, acc -> x - acc end)
       2
 
-      iex> List.foldl([1, 2, 3], {0, 0}, fn x, {a1, a2} -> {a1 + x, a2 - x} end)
-      {6, -6}
-
   """
   @spec foldl([elem], acc, (elem, acc -> acc)) :: acc when elem: var, acc: var
   def foldl(list, acc, fun) when is_list(list) and is_function(fun) do
@@ -251,16 +248,13 @@ defmodule List do
 
   @doc """
   Folds (reduces) the given list from the right with
-  a function. Requires an accumulator, which can be any value.
+  a function. Requires an accumulator.
 
   ## Examples
 
       iex> List.foldr([1, 2, 3, 4], 0, fn x, acc -> x - acc end)
       -2
 
-      iex> List.foldr([1, 2, 3, 4], %{sum: 0, product: 1}, fn x, %{sum: a1, product: a2} -> %{sum: a1 + x, product: a2 * x} end)
-      %{product: 24, sum: 10}
-
   """
   @spec foldr([elem], acc, (elem, acc -> acc)) :: acc when elem: var, acc: var
   def foldr(list, acc, fun) when is_list(list) and is_function(fun) do
@@ -339,52 +333,12 @@ defmodule List do
       iex> List.keyfind([a: 1, b: 2], :c, 0)
       nil
 
-  This function works for any list of tuples:
-
-      iex> List.keyfind([{22, "SSH"}, {80, "HTTP"}], 22, 0)
-      {22, "SSH"}
-
   """
   @spec keyfind([tuple], any, non_neg_integer, any) :: any
-  def keyfind(list, key, position, default \\ nil) when is_integer(position) do
+  def keyfind(list, key, position, default \\ nil) do
     :lists.keyfind(key, position + 1, list) || default
   end
 
-  @doc """
-  Receives a list of tuples and returns the first tuple
-  where the element at `position` in the tuple matches the
-  given `key`.
-
-  If no matching tuple is found, an error is raised.
-
-  ## Examples
-
-      iex> List.keyfind!([a: 1, b: 2], :a, 0)
-      {:a, 1}
-
-      iex> List.keyfind!([a: 1, b: 2], 2, 1)
-      {:b, 2}
-
-      iex> List.keyfind!([a: 1, b: 2], :c, 0)
-      ** (KeyError) key :c at position 0 not found in: [a: 1, b: 2]
-
-  This function works for any list of tuples:
-
-      iex> List.keyfind!([{22, "SSH"}, {80, "HTTP"}], 22, 0)
-      {22, "SSH"}
-
-  """
-  @doc since: "1.13.0"
-  @spec keyfind!([tuple], any, non_neg_integer) :: any
-  def keyfind!(list, key, position) when is_integer(position) do
-    :lists.keyfind(key, position + 1, list) ||
-      raise KeyError,
-        key: key,
-        term: list,
-        message:
-          "key #{inspect(key)} at position #{inspect(position)} not found in: #{inspect(list)}"
-  end
-
   @doc """
   Receives a list of tuples and returns `true` if there is
   a tuple where the element at `position` in the tuple matches
@@ -401,14 +355,9 @@ defmodule List do
       iex> List.keymember?([a: 1, b: 2], :c, 0)
       false
 
-  This function works for any list of tuples:
-
-      iex> List.keymember?([{22, "SSH"}, {80, "HTTP"}], 22, 0)
-      true
-
   """
   @spec keymember?([tuple], any, non_neg_integer) :: boolean
-  def keymember?(list, key, position) when is_integer(position) do
+  def keymember?(list, key, position) do
     :lists.keymember(key, position + 1, list)
   end
 
@@ -424,26 +373,15 @@ defmodule List do
       iex> List.keyreplace([a: 1, b: 2], :a, 1, {:a, 3})
       [a: 1, b: 2]
 
-  This function works for any list of tuples:
-
-      iex> List.keyreplace([{22, "SSH"}, {80, "HTTP"}], 22, 0, {22, "Secure Shell"})
-      [{22, "Secure Shell"}, {80, "HTTP"}]
-
   """
   @spec keyreplace([tuple], any, non_neg_integer, tuple) :: [tuple]
-  def keyreplace(list, key, position, new_tuple) when is_integer(position) do
+  def keyreplace(list, key, position, new_tuple) do
     :lists.keyreplace(key, position + 1, list, new_tuple)
   end
 
   @doc """
   Receives a list of tuples and sorts the elements
-  at `position` of the tuples.
-
-  The sort is stable.
-
-  A `sorter` argument is available since Elixir v1.14.0. Similar to
-  `Enum.sort/2`, the sorter can be an anonymous function, the atoms
-  `:asc` or `:desc`, or module that implements a compare function.
+  at `position` of the tuples. The sort is stable.
 
   ## Examples
 
@@ -453,69 +391,12 @@ defmodule List do
       iex> List.keysort([a: 5, c: 1, b: 3], 0)
       [a: 5, b: 3, c: 1]
 
-  To sort in descending order:
-
-      iex> List.keysort([a: 5, c: 1, b: 3], 0, :desc)
-      [c: 1, b: 3, a: 5]
-
-  As in `Enum.sort/2`, avoid using the default sorting function to sort
-  structs, as by default it performs structural comparison instead of a
-  semantic one. In such cases, you shall pass a sorting function as third
-  element or any module that implements a `compare/2` function. For example,
-  if you have tuples with user names and their birthday, and you want to
-  sort on their birthday, in both ascending and descending order, you should
-  do:
-
-      iex> users = [
-      ...>   {"Ellis", ~D[1943-05-11]},
-      ...>   {"Lovelace", ~D[1815-12-10]},
-      ...>   {"Turing", ~D[1912-06-23]}
-      ...> ]
-      iex> List.keysort(users, 1, Date)
-      [
-        {"Lovelace", ~D[1815-12-10]},
-        {"Turing", ~D[1912-06-23]},
-        {"Ellis", ~D[1943-05-11]}
-      ]
-      iex> List.keysort(users, 1, {:desc, Date})
-      [
-        {"Ellis", ~D[1943-05-11]},
-        {"Turing", ~D[1912-06-23]},
-        {"Lovelace", ~D[1815-12-10]}
-      ]
-
   """
-  @doc since: "1.14.0"
-  @spec keysort(
-          [tuple],
-          non_neg_integer,
-          (any, any -> boolean) | :asc | :desc | module() | {:asc | :desc, module()}
-        ) :: [tuple]
-  def keysort(list, position, sorter \\ :asc)
-
-  def keysort(list, position, :asc) when is_list(list) and is_integer(position) do
+  @spec keysort([tuple], non_neg_integer) :: [tuple]
+  def keysort(list, position) do
     :lists.keysort(position + 1, list)
   end
 
-  def keysort(list, position, sorter) when is_list(list) and is_integer(position) do
-    :lists.sort(keysort_fun(sorter, position + 1), list)
-  end
-
-  defp keysort_fun(sorter, position) when is_function(sorter, 2),
-    do: &sorter.(:erlang.element(position, &1), :erlang.element(position, &2))
-
-  defp keysort_fun(:desc, position),
-    do: &(:erlang.element(position, &1) >= :erlang.element(position, &2))
-
-  defp keysort_fun(module, position) when is_atom(module),
-    do: &(module.compare(:erlang.element(position, &1), :erlang.element(position, &2)) != :gt)
-
-  defp keysort_fun({:asc, module}, position) when is_atom(module),
-    do: &(module.compare(:erlang.element(position, &1), :erlang.element(position, &2)) != :gt)
-
-  defp keysort_fun({:desc, module}, position) when is_atom(module),
-    do: &(module.compare(:erlang.element(position, &1), :erlang.element(position, &2)) != :lt)
-
   @doc """
   Receives a `list` of tuples and replaces the element
   identified by `key` at `position` with `new_tuple`.
@@ -530,14 +411,9 @@ defmodule List do
       iex> List.keystore([a: 1, b: 2], :c, 0, {:c, 3})
       [a: 1, b: 2, c: 3]
 
-  This function works for any list of tuples:
-
-      iex> List.keystore([{22, "SSH"}], 80, 0, {80, "HTTP"})
-      [{22, "SSH"}, {80, "HTTP"}]
-
   """
   @spec keystore([tuple], any, non_neg_integer, tuple) :: [tuple, ...]
-  def keystore(list, key, position, new_tuple) when is_integer(position) do
+  def keystore(list, key, position, new_tuple) do
     :lists.keystore(key, position + 1, list, new_tuple)
   end
 
@@ -557,14 +433,9 @@ defmodule List do
       iex> List.keydelete([a: 1, b: 2], :c, 0)
       [a: 1, b: 2]
 
-  This function works for any list of tuples:
-
-      iex> List.keydelete([{22, "SSH"}, {80, "HTTP"}], 80, 0)
-      [{22, "SSH"}]
-
   """
   @spec keydelete([tuple], any, non_neg_integer) :: [tuple]
-  def keydelete(list, key, position) when is_integer(position) do
+  def keydelete(list, key, position) do
     :lists.keydelete(key, position + 1, list)
   end
 
@@ -586,14 +457,9 @@ defmodule List do
       iex> List.keytake([a: 1, b: 2], :c, 0)
       nil
 
-  This function works for any list of tuples:
-
-      iex> List.keytake([{22, "SSH"}, {80, "HTTP"}], 80, 0)
-      {{80, "HTTP"}, [{22, "SSH"}]}
-
   """
   @spec keytake([tuple], any, non_neg_integer) :: {tuple, [tuple]} | nil
-  def keytake(list, key, position) when is_integer(position) do
+  def keytake(list, key, position) do
     case :lists.keytake(key, position + 1, list) do
       {:value, element, list} -> {element, list}
       false -> nil
@@ -947,22 +813,14 @@ defmodule List do
   end
 
   @doc """
-  Converts a charlist to an existing atom.
+  Converts a charlist to an existing atom. Raises an `ArgumentError`
+  if the atom does not exist.
 
   Elixir supports conversions from charlists which contains any Unicode
-  code point. Raises an `ArgumentError` if the atom does not exist.
+  code point.
 
   Inlined by the compiler.
 
-  > #### Atoms and modules {: .info}
-  >
-  > Since Elixir is a compiled language, the atoms defined in a module
-  > will only exist after said module is loaded, which typically happens
-  > whenever a function in the module is executed. Therefore, it is
-  > generally recommended to call `List.to_existing_atom/1` only to
-  > convert atoms defined within the module making the function call
-  > to `to_existing_atom/1`.
-
   ## Examples
 
       iex> _ = :my_atom

lib/elixir/lib/macro/env.ex

@@ -21,51 +21,75 @@ defmodule Macro.Env do
 
   It contains the following fields:
 
+    * `aliases` -  a list of two-element tuples, where the first
+      element is the aliased name and the second one the actual name
     * `context` - the context of the environment; it can be `nil`
       (default context), `:guard` (inside a guard) or `:match` (inside a match)
     * `context_modules` - a list of modules defined in the current context
-    * `file` - the current absolute file name as a binary
+    * `file` - the current file name as a binary
     * `function` - a tuple as `{atom, integer}`, where the first
       element is the function name and the second its arity; returns
       `nil` if not inside a function
+    * `functions` - a list of functions imported from each module
     * `line` - the current line as an integer
+    * `macro_aliases` - a list of aliases defined inside the current macro
+    * `macros` - a list of macros imported from each module
     * `module` - the current module name
+    * `requires` - the list of required modules
 
   The following fields are private to Elixir's macro expansion mechanism and
   must not be accessed directly:
 
-    * `aliases`
-    * `functions`
-    * `macro_aliases`
-    * `macros`
+    * `contextual_vars`
+    * `current_vars`
     * `lexical_tracker`
-    * `requires`
+    * `prematch_vars`
     * `tracers`
-    * `versioned_vars`
+    * `unused_vars`
+
+  The following fields are deprecated and must not be accessed or relied on:
+
+    * `vars` - a list keeping all defined variables as `{var, context}`
 
   """
 
+  @type aliases :: [{module, module}]
   @type context :: :match | :guard | nil
   @type context_modules :: [module]
   @type file :: binary
+  @type functions :: [{module, [name_arity]}]
+  @type lexical_tracker :: pid | nil
   @type line :: non_neg_integer
+  @type macro_aliases :: [{module, {term, module}}]
+  @type macros :: [{module, [name_arity]}]
   @type name_arity :: {atom, arity}
+  @type requires :: [module]
   @type variable :: {atom, atom | term}
 
-  @typep aliases :: [{module, module}]
-  @typep functions :: [{module, [name_arity]}]
-  @typep lexical_tracker :: pid | nil
-  @typep macro_aliases :: [{module, {term, module}}]
-  @typep macros :: [{module, [name_arity]}]
-  @typep requires :: [module]
+  @typep contextual_vars :: [atom]
+  @typep current_vars ::
+           {%{optional(variable) => {var_version, var_type}},
+            %{optional(variable) => {var_version, var_type}} | false}
+  @typep unused_vars ::
+           {%{optional({atom, var_version}) => non_neg_integer | false}, non_neg_integer}
+  @typep prematch_vars ::
+           {%{optional(variable) => {var_version, var_type}}, non_neg_integer}
+           | :warn
+           | :raise
+           | :pin
+           | :apply
   @typep tracers :: [module]
-  @typep versioned_vars :: %{optional(variable) => var_version :: non_neg_integer}
+  @typep var_type :: :term
+  @typep var_version :: non_neg_integer
+  @typep vars :: [variable]
 
   @type t :: %{
           __struct__: __MODULE__,
           aliases: aliases,
           context: context,
           context_modules: context_modules,
+          contextual_vars: contextual_vars,
+          current_vars: current_vars,
           file: file,
           function: name_arity | nil,
           functions: functions,
@@ -74,44 +98,43 @@ defmodule Macro.Env do
           macro_aliases: macro_aliases,
           macros: macros,
           module: module,
+          prematch_vars: prematch_vars,
+          unused_vars: unused_vars,
           requires: requires,
           tracers: tracers,
-          versioned_vars: versioned_vars
+          vars: vars
         }
 
-  fields = [
-    aliases: [],
-    context: nil,
-    context_modules: [],
-    file: "nofile",
-    function: nil,
-    functions: [],
-    lexical_tracker: nil,
-    line: 0,
-    macro_aliases: [],
-    macros: [],
-    module: nil,
-    requires: [],
-    tracers: [],
-    versioned_vars: %{}
-  ]
-
   # Define the __struct__ callbacks by hand for bootstrap reasons.
-  {struct, [], kv, body} = Kernel.Utils.defstruct(__MODULE__, fields, false)
-  def __struct__(), do: unquote(:elixir_quote.escape(struct, false, :none))
-  def __struct__(unquote(kv)), do: unquote(body)
+  # TODO: Remove :vars field on v2.0
+  @doc false
+  def __struct__ do
+    %{
+      __struct__: __MODULE__,
+      aliases: [],
+      context: nil,
+      context_modules: [],
+      contextual_vars: [],
+      current_vars: {%{}, %{}},
+      file: "nofile",
+      function: nil,
+      functions: [],
+      lexical_tracker: nil,
+      line: 0,
+      macro_aliases: [],
+      macros: [],
+      module: nil,
+      prematch_vars: :warn,
+      requires: [],
+      tracers: [],
+      unused_vars: {%{}, 0},
+      vars: []
+    }
+  end
 
-  @doc """
-  Prunes compile information from the environment.
-
-  This happens when the environment is captured at compilation
-  time, for example, in the module body, and then used to
-  evaluate code after the module has been defined.
-  """
-  @doc since: "1.14.0"
-  @spec prune_compile_info(t) :: t
-  def prune_compile_info(env) do
-    %{env | lexical_tracker: nil, tracers: []}
+  @doc false
+  def __struct__(kv) do
+    Enum.reduce(kv, __struct__(), fn {k, v}, acc -> :maps.update(k, v, acc) end)
   end
 
   @doc """
@@ -126,30 +149,19 @@ defmodule Macro.Env do
   @spec vars(t) :: [variable]
   def vars(env)
 
-  def vars(%{__struct__: Macro.Env, versioned_vars: vars}) do
-    Map.keys(vars)
+  def vars(%{__struct__: Macro.Env, current_vars: {read, _}}) do
+    Map.keys(read)
   end
 
   @doc """
   Checks if a variable belongs to the environment.
-
-  ## Examples
-
-      iex> x = 13
-      iex> x
-      13
-      iex> Macro.Env.has_var?(__ENV__, {:x, nil})
-      true
-      iex> Macro.Env.has_var?(__ENV__, {:unknown, nil})
-      false
-
   """
   @doc since: "1.7.0"
   @spec has_var?(t, variable) :: boolean()
   def has_var?(env, var)
 
-  def has_var?(%{__struct__: Macro.Env, versioned_vars: vars}, var) do
-    Map.has_key?(vars, var)
+  def has_var?(%{__struct__: Macro.Env, current_vars: {read, _}}, var) do
+    Map.has_key?(read, var)
   end
 
   @doc """
@@ -163,117 +175,16 @@ defmodule Macro.Env do
     [file: file, line: line]
   end
 
-  @doc """
-  Fetches the alias for the given atom.
-
-  Returns `{:ok, alias}` if the alias exists, `:error`
-  otherwise.
-
-  ## Examples
-
-      iex> alias Foo.Bar, as: Baz
-      iex> Baz
-      Foo.Bar
-      iex> Macro.Env.fetch_alias(__ENV__, :Baz)
-      {:ok, Foo.Bar}
-      iex> Macro.Env.fetch_alias(__ENV__, :Unknown)
-      :error
-
-  """
-  @doc since: "1.13.0"
-  @spec fetch_alias(t, atom) :: {:ok, atom} | :error
-  def fetch_alias(%{__struct__: Macro.Env, aliases: aliases}, atom) when is_atom(atom),
-    do: Keyword.fetch(aliases, :"Elixir.#{atom}")
-
-  @doc """
-  Fetches the macro alias for the given atom.
-
-  Returns `{:ok, macro_alias}` if the alias exists, `:error`
-  otherwise.
-
-  A macro alias is only used inside quoted expansion. See
-  `fetch_alias/2` for a more general example.
-  """
-  @doc since: "1.13.0"
-  @spec fetch_macro_alias(t, atom) :: {:ok, atom} | :error
-  def fetch_macro_alias(%{__struct__: Macro.Env, macro_aliases: aliases}, atom)
-      when is_atom(atom),
-      do: Keyword.fetch(aliases, :"Elixir.#{atom}")
-
-  @doc """
-  Returns the modules from which the given `{name, arity}` was
-  imported.
-
-  It returns a list of two element tuples in the shape of
-  `{:function | :macro, module}`. The elements in the list
-  are in no particular order and the order is not guaranteed.
-
-  ## Examples
-
-      iex> Macro.Env.lookup_import(__ENV__, {:duplicate, 2})
-      []
-      iex> import Tuple, only: [duplicate: 2], warn: false
-      iex> Macro.Env.lookup_import(__ENV__, {:duplicate, 2})
-      [{:function, Tuple}]
-      iex> import List, only: [duplicate: 2], warn: false
-      iex> Macro.Env.lookup_import(__ENV__, {:duplicate, 2})
-      [{:function, List}, {:function, Tuple}]
-
-      iex> Macro.Env.lookup_import(__ENV__, {:def, 1})
-      [{:macro, Kernel}]
-
-  """
-  @doc since: "1.13.0"
-  @spec lookup_import(t, name_arity) :: [{:function | :macro, module}]
-  def lookup_import(
-        %{__struct__: Macro.Env, functions: functions, macros: macros},
-        {name, arity} = pair
-      )
-      when is_atom(name) and is_integer(arity) do
-    f = for {mod, pairs} <- functions, :ordsets.is_element(pair, pairs), do: {:function, mod}
-    m = for {mod, pairs} <- macros, :ordsets.is_element(pair, pairs), do: {:macro, mod}
-    f ++ m
-  end
-
-  @doc """
-  Returns true if the given module has been required.
-
-  ## Examples
-
-      iex> Macro.Env.required?(__ENV__, Integer)
-      false
-      iex> require Integer
-      iex> Macro.Env.required?(__ENV__, Integer)
-      true
-
-      iex> Macro.Env.required?(__ENV__, Kernel)
-      true
-  """
-  @doc since: "1.13.0"
-  @spec required?(t, module) :: boolean
-  def required?(%{__struct__: Macro.Env, requires: requires}, mod) when is_atom(mod),
-    do: mod in requires
-
-  @doc """
-  Prepend a tracer to the list of tracers in the environment.
-
-  ## Examples
-
-      Macro.Env.prepend_tracer(__ENV__, MyCustomTracer)
-
-  """
-  @doc since: "1.13.0"
-  @spec prepend_tracer(t, module) :: t
-  def prepend_tracer(%{__struct__: Macro.Env, tracers: tracers} = env, tracer) do
-    %{env | tracers: [tracer | tracers]}
-  end
-
   @doc """
   Returns a `Macro.Env` in the match context.
   """
   @spec to_match(t) :: t
-  def to_match(%{__struct__: Macro.Env} = env) do
-    %{env | context: :match}
+  def to_match(%{__struct__: Macro.Env, context: :match} = env) do
+    env
+  end
+
+  def to_match(%{__struct__: Macro.Env, current_vars: {read, _}, unused_vars: {_, counter}} = env) do
+    %{env | context: :match, prematch_vars: {read, counter}}
   end
 
   @doc """

lib/elixir/lib/map.ex

@@ -88,18 +88,12 @@ defmodule Map do
       %{1 => :one, 2 => :two, 3 => :three}
 
   Maps also support a specific update syntax to update the value stored under
-  *existing* keys. You can update using the atom keys syntax:
+  *existing* atom keys:
 
       iex> map = %{one: 1, two: 2}
       iex> %{map | one: "one"}
       %{one: "one", two: 2}
 
-  Or any other key:
-
-      iex> other_map = %{"three" => 3, "four" => 4}
-      iex> %{other_map | "three" => "three"}
-      %{"four" => 4, "three" => "three"}
-
   When a key that does not exist in the map is updated a `KeyError` exception will be raised:
 
       %{map | three: 3}
@@ -123,27 +117,6 @@ defmodule Map do
   @type value :: any
   @compile {:inline, fetch: 2, fetch!: 2, get: 2, put: 3, delete: 2, has_key?: 2, replace!: 3}
 
-  # TODO: Remove conditional on Erlang/OTP 24+
-  @compile {:no_warn_undefined, {:maps, :from_keys, 2}}
-  @doc """
-  Builds a map from the given `keys` and the fixed `value`.
-
-  ## Examples
-
-      iex> Map.from_keys([1, 2, 3], :number)
-      %{1 => :number, 2 => :number, 3 => :number}
-
-  """
-  @doc since: "1.14.0"
-  @spec from_keys([key], value) :: map
-  def from_keys(keys, value) do
-    if function_exported?(:maps, :from_keys, 2) do
-      :maps.from_keys(keys, value)
-    else
-      :maps.from_list(:lists.map(&{&1, value}, keys))
-    end
-  end
-
   @doc """
   Returns all keys from `map`.
 
@@ -241,24 +214,7 @@ defmodule Map do
 
   """
   @spec new(Enumerable.t(), (term -> {key, value})) :: map
-  def new(enumerable, transform)
-  def new(%_{} = enumerable, transform), do: new_from_enum(enumerable, transform)
-  def new(%{} = map, transform), do: new_from_map(map, transform)
-  def new(enumerable, transform), do: new_from_enum(enumerable, transform)
-
-  defp new_from_map(map, transform) when is_function(transform, 1) do
-    iter = :maps.iterator(map)
-    next = :maps.next(iter)
-    :maps.from_list(do_map(next, transform))
-  end
-
-  defp do_map(:none, _fun), do: []
-
-  defp do_map({key, value, iter}, transform) do
-    [transform.({key, value}) | do_map(:maps.next(iter), transform)]
-  end
-
-  defp new_from_enum(enumerable, transform) when is_function(transform, 1) do
+  def new(enumerable, transform) when is_function(transform, 1) do
     enumerable
     |> Enum.map(transform)
     |> :maps.from_list()
@@ -362,7 +318,7 @@ defmodule Map do
   def replace(map, key, value) do
     case map do
       %{^key => _value} ->
-        %{map | key => value}
+        put(map, key, value)
 
       %{} ->
         map
@@ -394,32 +350,6 @@ defmodule Map do
     :maps.update(key, value, map)
   end
 
-  @doc """
-  Replaces the value under `key` using the given function only if
-  `key` already exists in `map`.
-
-  In comparison to `replace/3`, this can be useful when it's expensive to calculate the value.
-
-  If `key` does not exist, the original map is returned unchanged.
-
-  ## Examples
-
-      iex> Map.replace_lazy(%{a: 1, b: 2}, :a, fn v -> v * 4 end)
-      %{a: 4, b: 2}
-
-      iex> Map.replace_lazy(%{a: 1, b: 2}, :c, fn v -> v * 4 end)
-      %{a: 1, b: 2}
-
-  """
-  @doc since: "1.14.0"
-  @spec replace_lazy(map, key, (existing_value :: value -> new_value :: value)) :: map
-  def replace_lazy(map, key, fun) when is_map(map) and is_function(fun, 1) do
-    case map do
-      %{^key => val} -> %{map | key => fun.(val)}
-      %{} -> map
-    end
-  end
-
   @doc """
   Evaluates `fun` and puts the result under `key`
   in `map` unless `key` is already present.
@@ -616,7 +546,7 @@ defmodule Map do
   If you have a struct and you would like to merge a set of keys into the
   struct, do not use this function, as it would merge all keys on the right
   side into the struct, even if the key is not part of the struct. Instead,
-  use `struct/2`.
+  use `Kernel.struct/2`.
 
   Inlined by the compiler.
 
@@ -684,7 +614,7 @@ defmodule Map do
   def update(map, key, default, fun) when is_function(fun, 1) do
     case map do
       %{^key => value} ->
-        %{map | key => fun.(value)}
+        put(map, key, fun.(value))
 
       %{} ->
         put(map, key, default)
@@ -880,7 +810,7 @@ defmodule Map do
   @spec update!(map, key, (existing_value :: value -> new_value :: value)) :: map
   def update!(map, key, fun) when is_function(fun, 1) do
     value = fetch!(map, key)
-    %{map | key => fun.(value)}
+    put(map, key, fun.(value))
   end
 
   @doc """
@@ -965,7 +895,7 @@ defmodule Map do
 
     case fun.(value) do
       {get, update} ->
-        {get, %{map | key => update}}
+        {get, put(map, key, update)}
 
       :pop ->
         {value, delete(map, key)}
@@ -1041,79 +971,4 @@ defmodule Map do
   def size(map) do
     map_size(map)
   end
-
-  @doc """
-  Returns a map containing only those pairs from `map`
-  for which `fun` returns a truthy value.
-
-  `fun` receives the key and value of each of the
-  elements in the map as a key-value pair.
-
-  See also `reject/2` which discards all elements where the
-  function returns a truthy value.
-
-  > Note: if you find yourself doing multiple calls to `Map.filter/2`
-  > and `Map.reject/2` in a pipeline, it is likely more efficient
-  > to use `Enum.map/2` and `Enum.filter/2` instead and convert to
-  > a map at the end using `Map.new/1`.
-
-  ## Examples
-
-      iex> Map.filter(%{one: 1, two: 2, three: 3}, fn {_key, val} -> rem(val, 2) == 1 end)
-      %{one: 1, three: 3}
-
-  """
-  @doc since: "1.13.0"
-  @spec filter(map, ({key, value} -> as_boolean(term))) :: map
-  def filter(map, fun) when is_map(map) and is_function(fun, 1) do
-    iter = :maps.iterator(map)
-    next = :maps.next(iter)
-    :maps.from_list(do_filter(next, fun))
-  end
-
-  defp do_filter(:none, _fun), do: []
-
-  defp do_filter({key, value, iter}, fun) do
-    if fun.({key, value}) do
-      [{key, value} | do_filter(:maps.next(iter), fun)]
-    else
-      do_filter(:maps.next(iter), fun)
-    end
-  end
-
-  @doc """
-  Returns map excluding the pairs from `map` for which `fun` returns
-  a truthy value.
-
-  See also `filter/2`.
-
-  ## Examples
-
-      iex> Map.reject(%{one: 1, two: 2, three: 3}, fn {_key, val} -> rem(val, 2) == 1 end)
-      %{two: 2}
-
-  """
-  @doc since: "1.13.0"
-  @spec reject(map, ({key, value} -> as_boolean(term))) :: map
-  def reject(map, fun) when is_map(map) and is_function(fun, 1) do
-    iter = :maps.iterator(map)
-    next = :maps.next(iter)
-    :maps.from_list(do_reject(next, fun))
-  end
-
-  defp do_reject(:none, _fun), do: []
-
-  defp do_reject({key, value, iter}, fun) do
-    if fun.({key, value}) do
-      do_reject(:maps.next(iter), fun)
-    else
-      [{key, value} | do_reject(:maps.next(iter), fun)]
-    end
-  end
-
-  @doc false
-  @deprecated "Use Map.new/2 instead (invoke Map.from_struct/1 before if you have a struct)"
-  def map(map, fun) when is_map(map) do
-    :maps.map(fn k, v -> fun.({k, v}) end, map)
-  end
 end

lib/elixir/lib/map_set.ex

@@ -8,18 +8,18 @@ defmodule MapSet do
   A set can be constructed using `MapSet.new/0`:
 
       iex> MapSet.new()
-      MapSet.new([])
+      #MapSet<[]>
 
   Elements in a set don't have to be of the same type and they can be
   populated from an [enumerable](`t:Enumerable.t/0`) using `MapSet.new/1`:
 
       iex> MapSet.new([1, :two, {"three"}])
-      MapSet.new([1, :two, {"three"}])
+      #MapSet<[1, :two, {"three"}]>
 
   Elements can be inserted using `MapSet.put/2`:
 
       iex> MapSet.new([2]) |> MapSet.put(4) |> MapSet.put(0)
-      MapSet.new([0, 2, 4])
+      #MapSet<[0, 2, 4]>
 
   By definition, sets can't contain duplicate elements: when
   inserting an element in a set where it's already present, the insertion is
@@ -27,9 +27,9 @@ defmodule MapSet do
 
       iex> map_set = MapSet.new()
       iex> MapSet.put(map_set, "foo")
-      MapSet.new(["foo"])
+      #MapSet<["foo"]>
       iex> map_set |> MapSet.put("foo") |> MapSet.put("foo")
-      MapSet.new(["foo"])
+      #MapSet<["foo"]>
 
   A `MapSet` is represented internally using the `%MapSet{}` struct. This struct
   can be used whenever there's a need to pattern match on something being a `MapSet`:
@@ -54,12 +54,10 @@ defmodule MapSet do
 
   @type value :: term
 
-  @opaque internal(value) :: %{optional(value) => []}
-  @type t(value) :: %__MODULE__{map: internal(value)}
+  @opaque t(value) :: %__MODULE__{map: %{optional(value) => []}}
   @type t :: t(term)
 
-  # TODO: Remove version key when we require Erlang/OTP 24
-  # TODO: Implement the functions in this module using Erlang/OTP 24 new sets
+  # TODO: Remove version key on Elixir v2.0
   defstruct map: %{}, version: 2
 
   @doc """
@@ -68,7 +66,7 @@ defmodule MapSet do
   ## Examples
 
       iex> MapSet.new()
-      MapSet.new([])
+      #MapSet<[]>
 
   """
   @spec new :: t
@@ -80,19 +78,23 @@ defmodule MapSet do
   ## Examples
 
       iex> MapSet.new([:b, :a, 3])
-      MapSet.new([3, :a, :b])
+      #MapSet<[3, :a, :b]>
       iex> MapSet.new([3, 3, 3, 2, 2, 1])
-      MapSet.new([1, 2, 3])
+      #MapSet<[1, 2, 3]>
 
   """
-  @spec new(Enumerable.t()) :: t
+  @spec new(Enum.t()) :: t
   def new(enumerable)
 
   def new(%__MODULE__{} = map_set), do: map_set
 
   def new(enumerable) do
-    keys = Enum.to_list(enumerable)
-    %MapSet{map: Map.from_keys(keys, @dummy_value)}
+    map =
+      enumerable
+      |> Enum.to_list()
+      |> new_from_list([])
+
+    %MapSet{map: map}
   end
 
   @doc """
@@ -101,13 +103,33 @@ defmodule MapSet do
   ## Examples
 
       iex> MapSet.new([1, 2, 1], fn x -> 2 * x end)
-      MapSet.new([2, 4])
+      #MapSet<[2, 4]>
 
   """
-  @spec new(Enumerable.t(), (term -> val)) :: t(val) when val: value
+  @spec new(Enum.t(), (term -> val)) :: t(val) when val: value
   def new(enumerable, transform) when is_function(transform, 1) do
-    keys = Enum.map(enumerable, transform)
-    %MapSet{map: Map.from_keys(keys, @dummy_value)}
+    map =
+      enumerable
+      |> Enum.to_list()
+      |> new_from_list_transform(transform, [])
+
+    %MapSet{map: map}
+  end
+
+  defp new_from_list([], acc) do
+    Map.new(acc)
+  end
+
+  defp new_from_list([element | rest], acc) do
+    new_from_list(rest, [{element, @dummy_value} | acc])
+  end
+
+  defp new_from_list_transform([], _fun, acc) do
+    Map.new(acc)
+  end
+
+  defp new_from_list_transform([element | rest], fun, acc) do
+    new_from_list_transform(rest, fun, [{fun.(element), @dummy_value} | acc])
   end
 
   @doc """
@@ -119,9 +141,9 @@ defmodule MapSet do
 
       iex> map_set = MapSet.new([1, 2, 3])
       iex> MapSet.delete(map_set, 4)
-      MapSet.new([1, 2, 3])
+      #MapSet<[1, 2, 3]>
       iex> MapSet.delete(map_set, 2)
-      MapSet.new([1, 3])
+      #MapSet<[1, 3]>
 
   """
   @spec delete(t(val1), val2) :: t(val1) when val1: value, val2: value
@@ -135,7 +157,7 @@ defmodule MapSet do
   ## Examples
 
       iex> MapSet.difference(MapSet.new([1, 2]), MapSet.new([2, 3, 4]))
-      MapSet.new([1])
+      #MapSet<[1]>
 
   """
   @spec difference(t(val1), t(val2)) :: t(val1) when val1: value, val2: value
@@ -161,51 +183,13 @@ defmodule MapSet do
     %{map_set | map: Map.drop(map1, Map.keys(map2))}
   end
 
-  defp filter_not_in(:none, _map2, acc), do: Map.from_keys(acc, @dummy_value)
+  defp filter_not_in(:none, _map2, acc), do: Map.new(acc)
 
   defp filter_not_in({key, _val, iter}, map2, acc) do
-    if is_map_key(map2, key) do
+    if :erlang.is_map_key(key, map2) do
       filter_not_in(:maps.next(iter), map2, acc)
     else
-      filter_not_in(:maps.next(iter), map2, [key | acc])
-    end
-  end
-
-  @doc """
-  Returns a set with elements that are present in only one but not both sets.
-
-  ## Examples
-
-      iex> MapSet.symmetric_difference(MapSet.new([1, 2, 3]), MapSet.new([2, 3, 4]))
-      MapSet.new([1, 4])
-  """
-  @doc since: "1.14.0"
-  @spec symmetric_difference(t(val1), t(val2)) :: t(val1 | val2) when val1: value, val2: value
-  def symmetric_difference(%MapSet{map: map1}, %MapSet{map: map2}) do
-    {small, large} = order_by_size(map1, map2)
-
-    map =
-      large
-      |> :maps.iterator()
-      |> :maps.next()
-      |> disjointer(small, [])
-
-    %MapSet{map: map}
-  end
-
-  defp disjointer(:none, small, list) do
-    list |> Map.from_keys(@dummy_value) |> Map.merge(small)
-  end
-
-  defp disjointer({key, _val, iter}, small, list) do
-    if is_map_key(small, key) do
-      iter
-      |> :maps.next()
-      |> disjointer(Map.delete(small, key), list)
-    else
-      iter
-      |> :maps.next()
-      |> disjointer(small, [key | list])
+      filter_not_in(:maps.next(iter), map2, [{key, @dummy_value} | acc])
     end
   end
 
@@ -233,7 +217,7 @@ defmodule MapSet do
   defp none_in?(:none, _), do: true
 
   defp none_in?({key, _val, iter}, map2) do
-    not is_map_key(map2, key) and none_in?(:maps.next(iter), map2)
+    not :erlang.is_map_key(key, map2) and none_in?(:maps.next(iter), map2)
   end
 
   @doc """
@@ -270,10 +254,10 @@ defmodule MapSet do
   ## Examples
 
       iex> MapSet.intersection(MapSet.new([1, 2]), MapSet.new([2, 3, 4]))
-      MapSet.new([2])
+      #MapSet<[2]>
 
       iex> MapSet.intersection(MapSet.new([1, 2]), MapSet.new([3, 4]))
-      MapSet.new([])
+      #MapSet<[]>
 
   """
   @spec intersection(t(val), t(val)) :: t(val) when val: value
@@ -295,7 +279,7 @@ defmodule MapSet do
   """
   @spec member?(t, value) :: boolean
   def member?(%MapSet{map: map}, value) do
-    is_map_key(map, value)
+    :erlang.is_map_key(value, map)
   end
 
   @doc """
@@ -304,9 +288,9 @@ defmodule MapSet do
   ## Examples
 
       iex> MapSet.put(MapSet.new([1, 2, 3]), 3)
-      MapSet.new([1, 2, 3])
+      #MapSet<[1, 2, 3]>
       iex> MapSet.put(MapSet.new([1, 2, 3]), 4)
-      MapSet.new([1, 2, 3, 4])
+      #MapSet<[1, 2, 3, 4]>
 
   """
   @spec put(t(val), new_val) :: t(val | new_val) when val: value, new_val: value
@@ -379,7 +363,7 @@ defmodule MapSet do
   ## Examples
 
       iex> MapSet.union(MapSet.new([1, 2]), MapSet.new([2, 3, 4]))
-      MapSet.new([1, 2, 3, 4])
+      #MapSet<[1, 2, 3, 4]>
 
   """
   @spec union(t(val1), t(val2)) :: t(val1 | val2) when val1: value, val2: value
@@ -390,88 +374,14 @@ defmodule MapSet do
   end
 
   def union(%MapSet{map: map1}, %MapSet{map: map2}) do
-    keys = Map.keys(map1) ++ Map.keys(map2)
-    %MapSet{map: Map.from_keys(keys, @dummy_value)}
+    map = new_from_list(Map.keys(map1) ++ Map.keys(map2), [])
+    %MapSet{map: map}
   end
 
   @compile {:inline, [order_by_size: 2]}
   defp order_by_size(map1, map2) when map_size(map1) > map_size(map2), do: {map2, map1}
   defp order_by_size(map1, map2), do: {map1, map2}
 
-  @doc """
-  Filters the set by returning only the elements from `set` for which invoking
-  `fun` returns a truthy value.
-
-  Also see `reject/2` which discards all elements where the function returns
-  a truthy value.
-
-  > Note: if you find yourself doing multiple calls to `MapSet.filter/2`
-  > and `MapSet.reject/2` in a pipeline, it is likely more efficient
-  > to use `Enum.map/2` and `Enum.filter/2` instead and convert to
-  > a map at the end using `Map.new/1`.
-
-  ## Examples
-
-      iex> MapSet.filter(MapSet.new(1..5), fn x -> x > 3 end)
-      MapSet.new([4, 5])
-
-      iex> MapSet.filter(MapSet.new(["a", :b, "c"]), &is_atom/1)
-      MapSet.new([:b])
-
-  """
-  @doc since: "1.14.0"
-  @spec filter(t(a), (a -> as_boolean(term))) :: t(a) when a: value
-  def filter(%MapSet{map: map}, fun) when is_map(map) and is_function(fun) do
-    iter = :maps.iterator(map)
-    next = :maps.next(iter)
-    keys = filter_keys(next, fun)
-    %MapSet{map: Map.from_keys(keys, @dummy_value)}
-  end
-
-  defp filter_keys(:none, _fun), do: []
-
-  defp filter_keys({key, _value, iter}, fun) do
-    if fun.(key) do
-      [key | filter_keys(:maps.next(iter), fun)]
-    else
-      filter_keys(:maps.next(iter), fun)
-    end
-  end
-
-  @doc """
-  Returns a set by excluding the elements from `set` for which invoking `fun`
-  returns a truthy value.
-
-  See also `filter/2`.
-
-  ## Examples
-
-      iex> MapSet.reject(MapSet.new(1..5), fn x -> rem(x, 2) != 0 end)
-      MapSet.new([2, 4])
-
-      iex> MapSet.reject(MapSet.new(["a", :b, "c"]), &is_atom/1)
-      MapSet.new(["a", "c"])
-
-  """
-  @doc since: "1.14.0"
-  @spec reject(t(a), (a -> as_boolean(term))) :: t(a) when a: value
-  def reject(%MapSet{map: map}, fun) when is_map(map) and is_function(fun) do
-    iter = :maps.iterator(map)
-    next = :maps.next(iter)
-    keys = reject_keys(next, fun)
-    %MapSet{map: Map.from_keys(keys, @dummy_value)}
-  end
-
-  defp reject_keys(:none, _fun), do: []
-
-  defp reject_keys({key, _value, iter}, fun) do
-    if fun.(key) do
-      reject_keys(:maps.next(iter), fun)
-    else
-      [key | reject_keys(:maps.next(iter), fun)]
-    end
-  end
-
   defimpl Enumerable do
     def count(map_set) do
       {:ok, MapSet.size(map_set)}
@@ -483,7 +393,7 @@ defmodule MapSet do
 
     def slice(map_set) do
       size = MapSet.size(map_set)
-      {:ok, size, &MapSet.to_list/1}
+      {:ok, size, &Enumerable.List.slice(MapSet.to_list(map_set), &1, &2, size)}
     end
 
     def reduce(map_set, acc, fun) do
@@ -494,8 +404,8 @@ defmodule MapSet do
   defimpl Collectable do
     def into(map_set) do
       fun = fn
-        list, {:cont, x} -> [x | list]
-        list, :done -> %{map_set | map: Map.merge(map_set.map, Map.from_keys(list, []))}
+        list, {:cont, x} -> [{x, []} | list]
+        list, :done -> %{map_set | map: Map.merge(map_set.map, Map.new(list))}
         _, :halt -> :ok
       end
 
@@ -508,7 +418,7 @@ defmodule MapSet do
 
     def inspect(map_set, opts) do
       opts = %Inspect.Opts{opts | charlists: :as_lists}
-      concat(["MapSet.new(", Inspect.List.inspect(MapSet.to_list(map_set), opts), ")"])
+      concat(["#MapSet<", Inspect.List.inspect(MapSet.to_list(map_set), opts), ">"])
     end
   end
 end

lib/elixir/lib/module/locals_tracker.ex

@@ -71,9 +71,8 @@ defmodule Module.LocalsTracker do
     :ok
   end
 
-  @doc """
-  Collect all conflicting imports with the given functions
-  """
+  # Collecting all conflicting imports with the given functions
+  @doc false
   def collect_imports_conflicts({set, _bag}, all_defined) do
     for {pair, _, meta, _} <- all_defined, n = out_neighbour(set, {:import, pair}) do
       {meta, {n, pair}}

lib/elixir/lib/module/parallel_checker.ex

@@ -1,165 +1,44 @@
 defmodule Module.ParallelChecker do
   @moduledoc false
 
-  import Kernel, except: [spawn: 3]
-
   @type cache() :: {pid(), :ets.tid()}
   @type warning() :: term()
   @type kind() :: :def | :defmacro
   @type mode() :: :elixir | :erlang
 
-  @doc """
-  Initializes the parallel checker process.
-  """
-  def start_link(schedulers \\ nil) do
-    :gen_server.start_link(__MODULE__, schedulers, [])
-  end
-
-  @doc """
-  Stops the parallel checker process.
-  """
-  def stop(checker) do
-    send(checker, {__MODULE__, :stop})
-    :ok
-  end
-
-  @doc """
-  Gets the parallel checker data from pdict.
-  """
-  def get do
-    case :erlang.get(:elixir_checker_info) do
-      {parent, nil} ->
-        {:ok, checker} = start_link()
-        put(parent, checker)
-        {parent, checker}
-
-      {parent, checker} ->
-        {parent, checker}
-    end
-  end
-
-  @doc """
-  Stores the parallel checker information.
-  """
-  def put(pid, checker) when is_pid(pid) and is_pid(checker) do
-    :erlang.put(:elixir_checker_info, {pid, checker})
-  end
-
-  @doc """
-  Spawns a process that runs the parallel checker.
-  """
-  def spawn({pid, checker}, module, info) do
-    ref = make_ref()
-
-    spawned =
-      spawn(fn ->
-        Process.link(pid)
-        mon_ref = Process.monitor(pid)
-
-        receive do
-          {^ref, :cache, ets} ->
-            module_map =
-              if is_map(info) do
-                info
-              else
-                info |> File.read!() |> maybe_module_map(module)
-              end
-
-            module_map && cache_from_module_map(ets, module_map)
-            send(checker, {ref, :cached})
-
-            receive do
-              {^ref, :check} ->
-                # Set the compiler info so we can collect warnings
-                :erlang.put(:elixir_compiler_info, {pid, self()})
-
-                warnings =
-                  if module_map do
-                    check_module(module_map, {checker, ets})
-                  else
-                    []
-                  end
-
-                send(pid, {__MODULE__, module, warnings})
-                send(checker, {__MODULE__, :done})
-            end
-
-          {:DOWN, ^mon_ref, _, _, _} ->
-            :ok
-        end
-      end)
-
-    register(checker, spawned, ref)
-    :ok
-  end
-
-  @doc """
-  Verifies the given compilation function
-  by starting a checker if one does not exist.
-  See `verify/3`.
-  """
-  def verify(fun) do
-    case :erlang.get(:elixir_compiler_info) do
-      :undefined ->
-        previous = :erlang.put(:elixir_checker_info, {self(), nil})
-
-        try do
-          result = fun.()
-
-          case :erlang.get(:elixir_checker_info) do
-            {_, nil} -> :ok
-            {_, checker} -> verify(checker, [])
-          end
-
-          result
-        after
-          {_, checker} = :erlang.get(:elixir_checker_info)
-
-          if previous != :undefined do
-            :erlang.put(:elixir_checker_info, previous)
-          else
-            :erlang.erase(:elixir_checker_info)
-          end
-
-          checker && stop(checker)
-        end
-
-      _ ->
-        # If we are during compilation, then they will be
-        # reported to the compiler, which will validate them.
-        fun.()
-    end
-  end
-
   @doc """
   Receives pairs of module maps and BEAM binaries. In parallel it verifies
   the modules and adds the ExCk chunk to the binaries. Returns the updated
-  list of warnings from the verification.
+  binaries and a list of warnings from the verification.
   """
-  @spec verify(pid(), [{module(), binary()}]) :: [warning()]
-  def verify(checker, runtime_files) do
-    for {module, file} <- runtime_files do
-      spawn({self(), checker}, module, file)
-    end
+  @spec verify([{map(), binary()}], [{module(), binary()}], pos_integer() | nil) :: [warning()]
+  def verify(compiled_modules, runtime_binaries, schedulers \\ nil) do
+    compiled_maps = Enum.map(compiled_modules, fn {map, _binary} -> {map.module, map} end)
 
-    modules = :gen_server.call(checker, :start)
-    collect_results(modules, [])
+    case compiled_maps ++ runtime_binaries do
+      [] ->
+        []
+
+      check_modules ->
+        schedulers = schedulers || max(:erlang.system_info(:schedulers_online), 2)
+
+        {:ok, server} =
+          :gen_server.start_link(__MODULE__, [check_modules, self(), schedulers], [])
+
+        preload_cache(get_ets(server), check_modules)
+        start(server)
+        collect_results(length(check_modules), [])
+    end
   end
 
-  defp collect_results([], warnings) do
+  defp collect_results(0, warnings) do
     warnings
   end
 
-  defp collect_results(modules, warnings) do
+  defp collect_results(count, warnings) do
     receive do
-      {:warning, file, location, message} ->
-        file = file && Path.absname(file)
-        message = :unicode.characters_to_binary(message)
-        warning = {file, location, message}
-        collect_results(modules, [warning | warnings])
-
       {__MODULE__, _module, new_warnings} ->
-        collect_results(tl(modules), new_warnings ++ warnings)
+        collect_results(count - 1, new_warnings ++ warnings)
     end
   end
 
@@ -167,8 +46,8 @@ defmodule Module.ParallelChecker do
   Test cache.
   """
   def test_cache do
-    {:ok, checker} = start_link()
-    {checker, :gen_server.call(checker, :ets)}
+    {:ok, pid} = :gen_server.start_link(__MODULE__, [[], self(), 1], [])
+    {pid, get_ets(pid)}
   end
 
   @doc """
@@ -219,26 +98,35 @@ defmodule Module.ParallelChecker do
 
   ## Module checking
 
-  defp check_module(module_map, cache) do
-    %{module: module, file: file, compile_opts: compile_opts, definitions: definitions} =
-      module_map
+  defp check_module(module, cache) do
+    case extract_definitions(module) do
+      {:ok, module, file, definitions, no_warn_undefined} ->
+        Module.Types.warnings(module, file, definitions, no_warn_undefined, cache)
+        |> group_warnings()
+        |> emit_warnings()
 
+      :error ->
+        []
+    end
+  end
+
+  defp extract_definitions({module, module_map}) when is_map(module_map) do
     no_warn_undefined =
-      compile_opts
+      module_map.compile_opts
       |> extract_no_warn_undefined()
       |> merge_compiler_no_warn_undefined()
 
-    warnings =
-      module
-      |> Module.Types.warnings(file, definitions, no_warn_undefined, cache)
-      |> group_warnings()
-      |> emit_warnings()
+    {:ok, module, module_map.file, module_map.definitions, no_warn_undefined}
+  end
 
-    module_map
-    |> Map.get(:after_verify, [])
-    |> Enum.each(fn {verify_mod, verify_fun} -> apply(verify_mod, verify_fun, [module]) end)
-
-    warnings
+  defp extract_definitions({module, binary}) when is_binary(binary) do
+    with {:ok, {_, [debug_info: chunk]}} <- :beam_lib.chunks(binary, [:debug_info]),
+         {:debug_info_v1, backend, data} <- chunk,
+         {:ok, module_map} <- backend.debug_info(:elixir_v1, module, data, []) do
+      extract_definitions({module, module_map})
+    else
+      _ -> :error
+    end
   end
 
   defp extract_no_warn_undefined(compile_opts) do
@@ -251,8 +139,11 @@ defmodule Module.ParallelChecker do
 
   defp merge_compiler_no_warn_undefined(no_warn_undefined) do
     case Code.get_compiler_option(:no_warn_undefined) do
-      :all -> :all
-      list when is_list(list) -> no_warn_undefined ++ list
+      :all ->
+        :all
+
+      list when is_list(list) ->
+        no_warn_undefined ++ list
     end
   end
 
@@ -285,7 +176,7 @@ defmodule Module.ParallelChecker do
 
   defp format_locations(locations) do
     [
-      "Invalid call found at #{length(locations)} locations:\n",
+      "Found at #{length(locations)} locations:\n",
       Enum.map(locations, &format_location/1)
     ]
   end
@@ -313,7 +204,106 @@ defmodule Module.ParallelChecker do
     IO.puts(:stderr, [:elixir_errors.warning_prefix(), message])
   end
 
-  ## Cache
+  ## Server callbacks
+
+  def init([modules, send_results, schedulers]) do
+    ets = :ets.new(:checker_cache, [:set, :public, {:read_concurrency, true}])
+
+    state = %{
+      ets: ets,
+      waiting: %{},
+      send_results: send_results,
+      modules: modules,
+      spawned: 0,
+      schedulers: schedulers
+    }
+
+    {:ok, state}
+  end
+
+  def handle_call({:lock, module}, from, %{waiting: waiting} = state) do
+    case waiting do
+      %{^module => froms} ->
+        waiting = Map.put(state.waiting, module, [from | froms])
+        {:noreply, %{state | waiting: waiting}}
+
+      %{} ->
+        waiting = Map.put(state.waiting, module, [])
+        {:reply, true, %{state | waiting: waiting}}
+    end
+  end
+
+  def handle_call({:unlock, module}, _from, %{waiting: waiting} = state) do
+    froms = Map.fetch!(waiting, module)
+    Enum.each(froms, &:gen_server.reply(&1, false))
+    waiting = Map.delete(waiting, module)
+    {:reply, :ok, %{state | waiting: waiting}}
+  end
+
+  def handle_call(:get_ets, _from, %{ets: ets} = state) do
+    {:reply, ets, state}
+  end
+
+  def handle_cast(:start, state) do
+    {:noreply, spawn_checkers(state)}
+  end
+
+  def handle_info({__MODULE__, :done}, state) do
+    state = %{state | spawned: state.spawned - 1}
+
+    if state.spawned == 0 and state.modules == [] do
+      {:stop, :normal, state}
+    else
+      state = spawn_checkers(state)
+      {:noreply, state}
+    end
+  end
+
+  defp lock(server, module) do
+    :gen_server.call(server, {:lock, module}, :infinity)
+  end
+
+  defp unlock(server, module) do
+    :gen_server.call(server, {:unlock, module})
+  end
+
+  defp get_ets(server) do
+    :gen_server.call(server, :get_ets)
+  end
+
+  defp start(server) do
+    :gen_server.cast(server, :start)
+  end
+
+  defp preload_cache(ets, modules) do
+    Enum.each(modules, fn
+      {_module, map} when is_map(map) -> cache_from_module_map(ets, map)
+      {module, binary} when is_binary(binary) -> cache_from_chunk(ets, module, binary)
+    end)
+  end
+
+  defp spawn_checkers(%{modules: []} = state) do
+    state
+  end
+
+  defp spawn_checkers(%{spawned: spawned, schedulers: schedulers} = state)
+       when spawned >= schedulers do
+    state
+  end
+
+  defp spawn_checkers(%{modules: [{module, _} = verify | modules]} = state) do
+    parent = self()
+    ets = state.ets
+    send_results_pid = state.send_results
+
+    spawn_link(fn ->
+      warnings = check_module(verify, {parent, ets})
+      send(send_results_pid, {__MODULE__, module, warnings})
+      send(parent, {__MODULE__, :done})
+    end)
+
+    spawn_checkers(%{state | modules: modules, spawned: state.spawned + 1})
+  end
 
   defp cache_module({server, ets}, module) do
     if lock(server, module) do
@@ -323,9 +313,14 @@ defmodule Module.ParallelChecker do
   end
 
   defp cache_from_chunk(ets, module) do
-    with {^module, binary, _filename} <- :code.get_object_code(module),
-         {:ok, ^module} <- binary |> :beam_lib.info() |> Keyword.fetch(:module),
-         {:ok, {_, [{'ExCk', chunk}]}} <- :beam_lib.chunks(binary, ['ExCk']),
+    case :code.get_object_code(module) do
+      {^module, binary, _filename} -> cache_from_chunk(ets, module, binary)
+      _other -> false
+    end
+  end
+
+  defp cache_from_chunk(ets, module, binary) do
+    with {:ok, {_, [{'ExCk', chunk}]}} <- :beam_lib.chunks(binary, ['ExCk']),
          {:elixir_checker_v1, contents} <- :erlang.binary_to_term(chunk) do
       cache_chunk(ets, module, contents.exports)
       true
@@ -334,6 +329,16 @@ defmodule Module.ParallelChecker do
     end
   end
 
+  defp cache_from_module_map(ets, map) do
+    exports =
+      [{{:__info__, 1}, :def}] ++
+        behaviour_exports(map) ++
+        definitions_to_exports(map.definitions)
+
+    deprecated = Map.new(map.deprecated)
+    cache_info(ets, map.module, exports, deprecated, :elixir)
+  end
+
   defp cache_from_info(ets, module) do
     if Code.ensure_loaded?(module) do
       {mode, exports} = info_exports(module)
@@ -364,28 +369,6 @@ defmodule Module.ParallelChecker do
     _ -> %{}
   end
 
-  defp maybe_module_map(binary, module) when is_binary(binary) do
-    # If a module was compiled without debug_info,
-    # then there is no module_map for further verification.
-    with {:ok, {_, [debug_info: chunk]}} <- :beam_lib.chunks(binary, [:debug_info]),
-         {:debug_info_v1, backend, data} = chunk,
-         {:ok, module_map} <- backend.debug_info(:elixir_v1, module, data, []) do
-      module_map
-    else
-      _ -> nil
-    end
-  end
-
-  defp cache_from_module_map(ets, map) do
-    exports =
-      [{{:__info__, 1}, :def}] ++
-        behaviour_exports(map) ++
-        definitions_to_exports(map.definitions)
-
-    deprecated = Map.new(map.deprecated)
-    cache_info(ets, map.module, exports, deprecated, :elixir)
-  end
-
   defp cache_info(ets, module, exports, deprecated, mode) do
     Enum.each(exports, fn {{fun, arity}, kind} ->
       reason = Map.get(deprecated, {fun, arity})
@@ -427,96 +410,4 @@ defmodule Module.ParallelChecker do
       end
     end)
   end
-
-  defp lock(server, module) do
-    :gen_server.call(server, {:lock, module}, :infinity)
-  end
-
-  defp unlock(server, module) do
-    :gen_server.call(server, {:unlock, module}, :infinity)
-  end
-
-  defp register(server, pid, ref) do
-    :gen_server.cast(server, {:register, pid, ref})
-  end
-
-  ## Server callbacks
-
-  def init(schedulers) do
-    ets = :ets.new(__MODULE__, [:set, :public, {:read_concurrency, true}])
-
-    state = %{
-      ets: ets,
-      waiting: %{},
-      modules: [],
-      spawned: 0,
-      schedulers: schedulers || max(:erlang.system_info(:schedulers_online), 2)
-    }
-
-    {:ok, state}
-  end
-
-  def handle_call(:start, _from, %{ets: ets, modules: modules} = state) do
-    for {pid, ref} <- modules do
-      send(pid, {ref, :cache, ets})
-    end
-
-    for {_pid, ref} <- modules do
-      receive do
-        {^ref, :cached} -> :ok
-      end
-    end
-
-    {:reply, modules, run_checkers(state)}
-  end
-
-  def handle_call(:ets, _from, state) do
-    {:reply, state.ets, state}
-  end
-
-  def handle_call({:lock, module}, from, %{waiting: waiting} = state) do
-    case waiting do
-      %{^module => froms} ->
-        waiting = Map.put(state.waiting, module, [from | froms])
-        {:noreply, %{state | waiting: waiting}}
-
-      %{} ->
-        waiting = Map.put(state.waiting, module, [])
-        {:reply, true, %{state | waiting: waiting}}
-    end
-  end
-
-  def handle_call({:unlock, module}, _from, %{waiting: waiting} = state) do
-    froms = Map.fetch!(waiting, module)
-    Enum.each(froms, &:gen_server.reply(&1, false))
-    waiting = Map.delete(waiting, module)
-    {:reply, :ok, %{state | waiting: waiting}}
-  end
-
-  def handle_info({__MODULE__, :done}, state) do
-    state = %{state | spawned: state.spawned - 1}
-    {:noreply, run_checkers(state)}
-  end
-
-  def handle_info({__MODULE__, :stop}, state) do
-    {:stop, :normal, state}
-  end
-
-  def handle_cast({:register, pid, ref}, %{modules: modules} = state) do
-    {:noreply, %{state | modules: [{pid, ref} | modules]}}
-  end
-
-  defp run_checkers(%{modules: []} = state) do
-    state
-  end
-
-  defp run_checkers(%{spawned: spawned, schedulers: schedulers} = state)
-       when spawned >= schedulers do
-    state
-  end
-
-  defp run_checkers(%{modules: [{pid, ref} | modules]} = state) do
-    send(pid, {ref, :check})
-    run_checkers(%{state | modules: modules, spawned: state.spawned + 1})
-  end
 end

lib/elixir/lib/module/types.ex

@@ -133,24 +133,13 @@ defmodule Module.Types do
   ## ERROR TO WARNING
 
   # Collect relevant information from context and traces to report error
-  def error_to_warning(:unable_apply, {mfa, args, expected, signature, stack}, context) do
-    {fun, arity} = context.function
-    line = get_meta(stack.last_expr)[:line]
-    location = {context.file, line, {context.module, fun, arity}}
-
-    traces = type_traces(stack, context)
-    {[signature | args], traces} = lift_all_types([signature | args], traces, context)
-    error = {:unable_apply, mfa, args, expected, signature, {location, stack.last_expr, traces}}
-    {Module.Types, error, location}
-  end
-
   def error_to_warning(:unable_unify, {left, right, stack}, context) do
     {fun, arity} = context.function
     line = get_meta(stack.last_expr)[:line]
     location = {context.file, line, {context.module, fun, arity}}
 
     traces = type_traces(stack, context)
-    {[left, right], traces} = lift_all_types([left, right], traces, context)
+    {left, right, traces} = lift_all_types(left, right, traces, context)
     error = {:unable_unify, left, right, {location, stack.last_expr, traces}}
     {Module.Types, error, location}
   end
@@ -194,87 +183,58 @@ defmodule Module.Types do
     end
   end
 
-  defp lift_all_types(types, traces, context) do
-    trace_types = for({:type, _, type, _, _} <- traces, do: type)
-    {types, lift_context} = Unify.lift_types(types, context)
-    {trace_types, _lift_context} = Unify.lift_types(trace_types, lift_context)
+  defp lift_all_types(left, right, traces, context) do
+    all_types = [left, right] ++ for({:type, _, type, _, _} <- traces, do: type)
+    [left, right | all_types] = Unify.lift_types(all_types, context)
 
     {traces, []} =
-      Enum.map_reduce(traces, trace_types, fn
+      Enum.map_reduce(traces, all_types, fn
         {:type, var, _, expr, location}, [type | acc] -> {{:type, var, type, expr, location}, acc}
         other, acc -> {other, acc}
       end)
 
-    {types, traces}
+    {left, right, traces}
   end
 
   ## FORMAT WARNINGS
 
-  def format_warning({:unable_apply, mfa, args, expected, signature, {location, expr, traces}}) do
-    {original_module, original_function, arity} = mfa
-    {_, _, args} = mfa_or_fa = erl_to_ex(original_module, original_function, args, [])
-    {module, function, ^arity} = call_to_mfa(mfa_or_fa)
-    format_mfa = Exception.format_mfa(module, function, arity)
-    {traces, [] = _hints} = format_traces(traces, [], false)
-
-    clauses =
-      Enum.map(signature, fn {ins, out} ->
-        {_, _, ins} = erl_to_ex(original_module, original_function, ins, [])
-
-        {:fun, [{ins, out}]}
-        |> Unify.format_type(false)
-        |> IO.iodata_to_binary()
-        |> binary_slice(1..-2//1)
-      end)
-
-    [
-      "expected #{format_mfa} to have signature:\n\n    ",
-      Enum.map_join(args, ", ", &Unify.format_type(&1, false)),
-      " -> #{Unify.format_type(expected, false)}",
-      "\n\nbut it has signature:\n\n    ",
-      indent(Enum.join(clauses, "\n")),
-      "\n\n",
-      format_expr(expr, location),
-      traces,
-      "Conflict found at"
-    ]
-  end
-
   def format_warning({:unable_unify, left, right, {location, expr, traces}}) do
-    if map_type?(left) and map_type?(right) and match?({:ok, _, _}, missing_field(left, right)) do
-      {:ok, atom, known_atoms} = missing_field(left, right)
+    cond do
+      map_type?(left) and map_type?(right) and match?({:ok, _, _}, missing_field(left, right)) ->
+        {:ok, atom, known_atoms} = missing_field(left, right)
 
-      # Drop the last trace which is the expression map.foo
-      traces = Enum.drop(traces, 1)
-      {traces, hints} = format_traces(traces, [left, right], true)
+        # Drop the last trace which is the expression map.foo
+        traces = Enum.drop(traces, 1)
+        {traces, hints} = format_traces(traces, true)
 
-      [
-        "undefined field \"#{atom}\" ",
-        format_expr(expr, location),
-        "expected one of the following fields: ",
-        Enum.map_join(Enum.sort(known_atoms), ", ", & &1),
-        "\n\n",
-        traces,
-        format_message_hints(hints),
-        "Conflict found at"
-      ]
-    else
-      simplify_left? = simplify_type?(left, right)
-      simplify_right? = simplify_type?(right, left)
+        [
+          "undefined field \"#{atom}\" ",
+          format_expr(expr, location),
+          "expected one of the following fields: ",
+          Enum.map_join(Enum.sort(known_atoms), ", ", & &1),
+          "\n\n",
+          traces,
+          format_message_hints(hints),
+          "Conflict found at"
+        ]
 
-      {traces, hints} = format_traces(traces, [left, right], simplify_left? or simplify_right?)
+      true ->
+        simplify_left? = simplify_type?(left, right)
+        simplify_right? = simplify_type?(right, left)
 
-      [
-        "incompatible types:\n\n    ",
-        Unify.format_type(left, simplify_left?),
-        " !~ ",
-        Unify.format_type(right, simplify_right?),
-        "\n\n",
-        format_expr(expr, location),
-        traces,
-        format_message_hints(hints),
-        "Conflict found at"
-      ]
+        {traces, hints} = format_traces(traces, simplify_left? or simplify_right?)
+
+        [
+          "incompatible types:\n\n    ",
+          Unify.format_type(left, simplify_left?),
+          " !~ ",
+          Unify.format_type(right, simplify_right?),
+          "\n\n",
+          format_expr(expr, location),
+          traces,
+          format_message_hints(hints),
+          "Conflict found at"
+        ]
     end
   end
 
@@ -303,17 +263,17 @@ defmodule Module.Types do
     end
   end
 
-  defp format_traces([], _types, _simplify?) do
+  defp format_traces([], _simplify?) do
     {[], []}
   end
 
-  defp format_traces(traces, types, simplify?) do
+  defp format_traces(traces, simplify?) do
     traces
     |> Enum.uniq()
     |> Enum.reverse()
     |> Enum.map_reduce([], fn
       {:type, var, type, expr, location}, hints ->
-        {hint, hints} = format_type_hint(type, types, expr, hints)
+        {hint, hints} = format_type_hint(type, expr, hints)
 
         trace = [
           "where \"",
@@ -358,7 +318,7 @@ defmodule Module.Types do
   end
 
   defp simplify_type?(type, other) do
-    map_like_type?(type) and not map_like_type?(other)
+    map_type?(type) and not map_type?(other)
   end
 
   ## EXPRESSION FORMATTING
@@ -401,16 +361,14 @@ defmodule Module.Types do
   ## Hints
 
   defp format_message_hints(hints) do
-    hints
-    |> Enum.uniq()
-    |> Enum.reverse()
-    |> Enum.map(&[format_message_hint(&1), "\n"])
+    hints |> Enum.uniq() |> Enum.reverse() |> Enum.map(&format_message_hint/1)
   end
 
   defp format_message_hint(:inferred_dot) do
     """
     HINT: "var.field" (without parentheses) implies "var" is a map() while \
     "var.fun()" (with parentheses) implies "var" is an atom()
+
     """
   end
 
@@ -420,24 +378,18 @@ defmodule Module.Types do
     integer() unless said otherwise. For example, <<expr>> assumes "expr" \
     is an integer. Pass a modifier, such as <<expr::float>> or <<expr::binary>>, \
     to change the default behaviour.
+
     """
   end
 
-  defp format_message_hint({:sized_and_unsize_tuples, {size, var}}) do
-    """
-    HINT: use pattern matching or "is_tuple(#{Macro.to_string(var)}) and \
-    tuple_size(#{Macro.to_string(var)}) == #{size}" to guard a sized tuple.
-    """
-  end
-
-  defp format_type_hint(type, types, expr, hints) do
-    case format_type_hint(type, types, expr) do
+  defp format_type_hint(type, expr, hints) do
+    case format_type_hint(type, expr) do
       {message, hint} -> {message, [hint | hints]}
       :error -> {[], hints}
     end
   end
 
-  defp format_type_hint(type, types, expr) do
+  defp format_type_hint(type, expr) do
     cond do
       dynamic_map_dot?(type, expr) ->
         {" (due to calling var.field)", :inferred_dot}
@@ -448,9 +400,6 @@ defmodule Module.Types do
       inferred_bitstring_spec?(type, expr) ->
         {[], :inferred_bitstring_spec}
 
-      message = sized_and_unsize_tuples(expr, types) ->
-        {[], {:sized_and_unsize_tuples, message}}
-
       true ->
         :error
     end
@@ -486,33 +435,15 @@ defmodule Module.Types do
     end
   end
 
-  defp sized_and_unsize_tuples({{:., _, [:erlang, :is_tuple]}, _, [var]}, types) do
-    case Enum.find(types, &match?({:tuple, _, _}, &1)) do
-      {:tuple, size, _} ->
-        {size, var}
-
-      nil ->
-        nil
-    end
-  end
-
-  defp sized_and_unsize_tuples(_expr, _types) do
-    nil
-  end
-
   ## Formatting helpers
 
   defp indent(string) do
-    String.replace(string, "\n", "\n    ")
+    String.replace(string, "\n", "    \n")
   end
 
   defp map_type?({:map, _}), do: true
   defp map_type?(_other), do: false
 
-  defp map_like_type?({:map, _}), do: true
-  defp map_like_type?({:union, union}), do: Enum.any?(union, &map_like_type?/1)
-  defp map_like_type?(_other), do: false
-
   defp atom_type?(:atom), do: true
   defp atom_type?({:atom, _}), do: false
   defp atom_type?({:union, union}), do: Enum.all?(union, &atom_type?/1)
@@ -520,7 +451,4 @@ defmodule Module.Types do
 
   defp integer_type?(:integer), do: true
   defp integer_type?(_other), do: false
-
-  defp call_to_mfa({{:., _, [mod, fun]}, _, args}), do: {mod, fun, length(args)}
-  defp call_to_mfa({fun, _, args}) when is_atom(fun), do: {Kernel, fun, length(args)}
 end

lib/elixir/lib/module/types/expr.ex

@@ -151,20 +151,16 @@ defmodule Module.Types.Expr do
          dynamic_value_pairs =
            Enum.map(arg_pairs, fn {:required, key, _value} -> {:required, key, :dynamic} end),
          args_type = {:map, dynamic_value_pairs ++ [{:optional, :dynamic, :dynamic}]},
-         {:ok, type, context} <- unify(map_type, args_type, stack, context) do
+         {:ok, type, context} <- unify(args_type, map_type, stack, context) do
       # Retrieve map type and overwrite with the new value types from the map update
-      case resolve_var(type, context) do
-        {:map, pairs} ->
-          updated_pairs =
-            Enum.reduce(arg_pairs, pairs, fn {:required, key, value}, pairs ->
-              List.keyreplace(pairs, key, 1, {:required, key, value})
-            end)
+      {:map, pairs} = resolve_var(type, context)
 
-          {:ok, {:map, updated_pairs}, context}
+      updated_pairs =
+        Enum.reduce(arg_pairs, pairs, fn {:required, key, value}, pairs ->
+          List.keyreplace(pairs, key, 1, {:required, key, value})
+        end)
 
-        _ ->
-          {:ok, :dynamic, context}
-      end
+      {:ok, {:map, updated_pairs}, context}
     end
   end
 
@@ -220,30 +216,6 @@ defmodule Module.Types.Expr do
     end
   end
 
-  # cond do pat -> expr end
-  def of_expr({:cond, _meta, [[{:do, clauses}]]} = expr, _expected, stack, context) do
-    stack = push_expr_stack(expr, stack)
-
-    {result, context} =
-      reduce_ok(clauses, context, fn {:->, meta, [head, body]}, context = acc ->
-        case of_expr(head, :dynamic, stack, context) do
-          {:ok, _, context} ->
-            with {:ok, _expr_type, context} <- of_expr(body, :dynamic, stack, context) do
-              {:ok, keep_warnings(acc, context)}
-            end
-
-          error ->
-            # Skip the clause if it the head has an error
-            if meta[:generated], do: {:ok, acc}, else: error
-        end
-      end)
-
-    case result do
-      :ok -> {:ok, :dynamic, context}
-      :error -> {:error, context}
-    end
-  end
-
   # case expr do pat -> expr end
   def of_expr({:case, _meta, [case_expr, [{:do, clauses}]]} = expr, _expected, stack, context) do
     stack = push_expr_stack(expr, stack)
@@ -329,7 +301,7 @@ defmodule Module.Types.Expr do
   end
 
   # for pat <- expr do expr end
-  def of_expr({:for, _meta, [_ | _] = args} = expr, _expected, stack, context) do
+  def of_expr({:for, _meta, args} = expr, _expected, stack, context) do
     stack = push_expr_stack(expr, stack)
     {clauses, [[{:do, block} | opts]]} = Enum.split(args, -1)
 
@@ -348,7 +320,7 @@ defmodule Module.Types.Expr do
   end
 
   # with pat <- expr do expr end
-  def of_expr({:with, _meta, [_ | _] = clauses} = expr, _expected, stack, context) do
+  def of_expr({:with, _meta, clauses} = expr, _expected, stack, context) do
     stack = push_expr_stack(expr, stack)
 
     case reduce_ok(clauses, context, &with_clause(&1, stack, &2)) do
@@ -362,10 +334,15 @@ defmodule Module.Types.Expr do
     # TODO: Use expected type to infer intersection return type
     stack = push_expr_stack(expr, stack)
 
-    with {:ok, _fun_type, context} <- of_expr(fun, :dynamic, stack, context),
-         {:ok, _arg_types, context} <-
-           map_reduce_ok(args, context, &of_expr(&1, :dynamic, stack, &2)) do
-      {:ok, :dynamic, context}
+    case of_expr(fun, :dynamic, stack, context) do
+      {:ok, _fun_type, context} ->
+        case map_reduce_ok(args, context, &of_expr(&1, :dynamic, stack, &2)) do
+          {:ok, _arg_types, context} -> {:ok, :dynamic, context}
+          {:error, reason} -> {:error, reason}
+        end
+
+      {:error, reason} ->
+        {:error, reason}
     end
   end
 
@@ -398,10 +375,11 @@ defmodule Module.Types.Expr do
     stack = push_expr_stack(expr2, stack)
 
     with {:ok, _expr_type, context} <- of_expr(expr1, :dynamic, stack, context),
-         {:ok, _fun_type, context} <- of_expr(fun, :dynamic, stack, context),
-         {:ok, _arg_types, context} <-
-           map_reduce_ok(args, context, &of_expr(&1, :dynamic, stack, &2)) do
-      {:ok, :dynamic, context}
+         {:ok, _fun_type, context} <- of_expr(fun, :dynamic, stack, context) do
+      case map_reduce_ok(args, context, &of_expr(&1, :dynamic, stack, &2)) do
+        {:ok, _arg_types, context} -> {:ok, :dynamic, context}
+        {:error, reason} -> {:error, reason}
+      end
     end
   end
 
@@ -497,19 +475,12 @@ defmodule Module.Types.Expr do
   end
 
   defp of_clauses(clauses, stack, context) do
-    reduce_ok(clauses, context, fn {:->, meta, [head, body]}, context = acc ->
+    reduce_ok(clauses, context, fn {:->, _meta, [head, body]}, context = acc ->
       {patterns, guards} = extract_head(head)
 
-      case Pattern.of_head(patterns, guards, stack, context) do
-        {:ok, _, context} ->
-          with {:ok, _expr_type, context} <- of_expr(body, :dynamic, stack, context) do
-            {:ok, keep_warnings(acc, context)}
-          end
-
-        error ->
-          # Skip the clause if it the head has an error
-          if meta[:generated], do: {:ok, acc}, else: error
-      end
+      with {:ok, _, context} <- Pattern.of_head(patterns, guards, stack, context),
+           {:ok, _expr_type, context} <- of_expr(body, :dynamic, stack, context),
+           do: {:ok, keep_warnings(acc, context)}
     end)
   end
 

lib/elixir/lib/module/types/helpers.ex

@@ -101,30 +101,6 @@ defmodule Module.Types.Helpers do
 
   defp do_map_reduce_ok([], {list, acc}, _fun), do: {:ok, Enum.reverse(list), acc}
 
-  @doc """
-  Like `Enum.flat_map/2` but only continues while `fun` returns `{:ok, list}`
-  and stops on `{:error, reason}`.
-  """
-  def flat_map_ok(list, fun) do
-    do_flat_map_ok(list, [], fun)
-  end
-
-  defp do_flat_map_ok([head | tail], acc, fun) do
-    case fun.(head) do
-      {:ok, elem} ->
-        do_flat_map_ok(tail, [elem | acc], fun)
-
-      {:error, reason} ->
-        {:error, reason}
-    end
-  end
-
-  defp do_flat_map_ok([], acc, _fun), do: {:ok, Enum.reverse(Enum.concat(acc))}
-
-  @doc """
-  Like `Enum.flat_map_reduce/3` but only continues while `fun` returns `{:ok, list, acc}`
-  and stops on `{:error, reason}`.
-  """
   def flat_map_reduce_ok(list, acc, fun) do
     do_flat_map_reduce_ok(list, {[], acc}, fun)
   end
@@ -154,10 +130,6 @@ defmodule Module.Types.Helpers do
     end
   end
 
-  @doc """
-  Combines a list of guard expressions `when x when y when z` to an expression
-  combined with `or`, `x or y or z`.
-  """
   # TODO: Remove this and let multiple when be treated as multiple clauses,
   #       meaning they will be intersection types
   def guards_to_or([]) do
@@ -167,30 +139,4 @@ defmodule Module.Types.Helpers do
   def guards_to_or(guards) do
     Enum.reduce(guards, fn guard, acc -> {{:., [], [:erlang, :orelse]}, [], [guard, acc]} end)
   end
-
-  @doc """
-  Like `Enum.zip/1` but will zip multiple lists together instead of only two.
-  """
-  def zip_many(lists) do
-    zip_many(lists, [], [[]])
-  end
-
-  defp zip_many([], [], [[] | acc]) do
-    map_reverse(acc, [], &Enum.reverse/1)
-  end
-
-  defp zip_many([], remain, [last | acc]) do
-    zip_many(Enum.reverse(remain), [], [[] | [last | acc]])
-  end
-
-  defp zip_many([[] | _], remain, [last | acc]) do
-    zip_many(Enum.reverse(remain), [], [last | acc])
-  end
-
-  defp zip_many([[elem | list1] | list2], remain, [last | acc]) do
-    zip_many(list2, [list1 | remain], [[elem | last] | acc])
-  end
-
-  defp map_reverse([], acc, _fun), do: acc
-  defp map_reverse([head | tail], acc, fun), do: map_reverse(tail, [fun.(head) | acc], fun)
 end

lib/elixir/lib/module/types/of.ex

@@ -237,7 +237,7 @@ defmodule Module.Types.Of do
   def remote(module, fun, arity, meta, context) when is_atom(module) do
     # TODO: In the future we may want to warn for modules defined
     # in the local context
-    if Keyword.get(meta, :context_module, false) do
+    if Keyword.get(meta, :context_module, false) and context.module != module do
       context
     else
       ParallelChecker.preload_module(context.cache, module)
@@ -327,7 +327,7 @@ defmodule Module.Types.Of do
     %{context | warnings: [{__MODULE__, warning, location} | context.warnings]}
   end
 
-  ## Warning formatting
+  ## Warning formating
 
   def format_warning({:undefined_module, module, fun, arity}) do
     [

lib/elixir/lib/module/types/pattern.ex

@@ -10,8 +10,8 @@ defmodule Module.Types.Pattern do
   def of_head(patterns, guards, stack, context) do
     with {:ok, types, context} <-
            map_reduce_ok(patterns, context, &of_pattern(&1, stack, &2)),
-         # TODO: Check that of_guard/4 returns boolean() | :fail
-         {:ok, _, context} <- of_guard(guards_to_or(guards), :dynamic, stack, context),
+         # TODO: Check that of_guard/3 returns boolean() | :fail
+         {:ok, _, context} <- of_guard(guards_to_or(guards), stack, context),
          do: {:ok, types, context}
   end
 
@@ -86,75 +86,69 @@ defmodule Module.Types.Pattern do
   # TODO: Some guards can be changed to intersection types or higher order types
   @boolean {:union, [{:atom, true}, {:atom, false}]}
   @number {:union, [:integer, :float]}
-  @unary_number_fun [{[:integer], :integer}, {[@number], :float}]
-  @binary_number_fun [
-    {[:integer, :integer], :integer},
-    {[:float, @number], :float},
-    {[@number, :float], :float}
-  ]
 
   @guard_functions %{
-    {:is_atom, 1} => [{[:atom], @boolean}],
-    {:is_binary, 1} => [{[:binary], @boolean}],
-    {:is_bitstring, 1} => [{[:binary], @boolean}],
-    {:is_boolean, 1} => [{[@boolean], @boolean}],
-    {:is_float, 1} => [{[:float], @boolean}],
-    {:is_function, 1} => [{[:fun], @boolean}],
-    {:is_function, 2} => [{[:fun, :integer], @boolean}],
-    {:is_integer, 1} => [{[:integer], @boolean}],
-    {:is_list, 1} => [{[{:list, :dynamic}], @boolean}],
-    {:is_map, 1} => [{[{:map, [{:optional, :dynamic, :dynamic}]}], @boolean}],
-    {:is_map_key, 2} => [{[:dynamic, {:map, [{:optional, :dynamic, :dynamic}]}], :dynamic}],
-    {:is_number, 1} => [{[@number], @boolean}],
-    {:is_pid, 1} => [{[:pid], @boolean}],
-    {:is_port, 1} => [{[:port], @boolean}],
-    {:is_reference, 1} => [{[:reference], @boolean}],
-    {:is_tuple, 1} => [{[:tuple], @boolean}],
-    {:<, 2} => [{[:dynamic, :dynamic], @boolean}],
-    {:"=<", 2} => [{[:dynamic, :dynamic], @boolean}],
-    {:>, 2} => [{[:dynamic, :dynamic], @boolean}],
-    {:>=, 2} => [{[:dynamic, :dynamic], @boolean}],
-    {:"/=", 2} => [{[:dynamic, :dynamic], @boolean}],
-    {:"=/=", 2} => [{[:dynamic, :dynamic], @boolean}],
-    {:==, 2} => [{[:dynamic, :dynamic], @boolean}],
-    {:"=:=", 2} => [{[:dynamic, :dynamic], @boolean}],
-    {:*, 2} => @binary_number_fun,
-    {:+, 1} => @unary_number_fun,
-    {:+, 2} => @binary_number_fun,
-    {:-, 1} => @unary_number_fun,
-    {:-, 2} => @binary_number_fun,
-    {:/, 2} => @binary_number_fun,
-    {:abs, 1} => @unary_number_fun,
-    {:ceil, 1} => [{[@number], :integer}],
-    {:floor, 1} => [{[@number], :integer}],
-    {:round, 1} => [{[@number], :integer}],
-    {:trunc, 1} => [{[@number], :integer}],
-    {:element, 2} => [{[:integer, :tuple], :dynamic}],
-    {:hd, 1} => [{[{:list, :dynamic}], :dynamic}],
-    {:length, 1} => [{[{:list, :dynamic}], :integer}],
-    {:map_get, 2} => [{[:dynamic, {:map, [{:optional, :dynamic, :dynamic}]}], :dynamic}],
-    {:map_size, 1} => [{[{:map, [{:optional, :dynamic, :dynamic}]}], :integer}],
-    {:tl, 1} => [{[{:list, :dynamic}], :dynamic}],
-    {:tuple_size, 1} => [{[:tuple], :integer}],
-    {:node, 1} => [{[{:union, [:pid, :reference, :port]}], :atom}],
-    {:binary_part, 3} => [{[:binary, :integer, :integer], :binary}],
-    {:bit_size, 1} => [{[:binary], :integer}],
-    {:byte_size, 1} => [{[:binary], :integer}],
-    {:size, 1} => [{[{:union, [:binary, :tuple]}], @boolean}],
-    {:div, 2} => [{[:integer, :integer], :integer}],
-    {:rem, 2} => [{[:integer, :integer], :integer}],
-    {:node, 0} => [{[], :atom}],
-    {:self, 0} => [{[], :pid}],
-    {:bnot, 1} => [{[:integer], :integer}],
-    {:band, 2} => [{[:integer, :integer], :integer}],
-    {:bor, 2} => [{[:integer, :integer], :integer}],
-    {:bxor, 2} => [{[:integer, :integer], :integer}],
-    {:bsl, 2} => [{[:integer, :integer], :integer}],
-    {:bsr, 2} => [{[:integer, :integer], :integer}],
-    {:or, 2} => [{[@boolean, @boolean], @boolean}],
-    {:and, 2} => [{[@boolean, @boolean], @boolean}],
-    {:xor, 2} => [{[@boolean, @boolean], @boolean}],
-    {:not, 1} => [{[@boolean], @boolean}]
+    {:is_atom, 1} => {[:atom], @boolean},
+    {:is_binary, 1} => {[:binary], @boolean},
+    {:is_bitstring, 1} => {[:binary], @boolean},
+    {:is_boolean, 1} => {[@boolean], @boolean},
+    {:is_float, 1} => {[:float], @boolean},
+    {:is_function, 1} => {[:fun], @boolean},
+    {:is_function, 2} => {[:fun, :integer], @boolean},
+    {:is_integer, 1} => {[:integer], @boolean},
+    {:is_list, 1} => {[{:list, :dynamic}], @boolean},
+    {:is_map, 1} => {[{:map, [{:optional, :dynamic, :dynamic}]}], @boolean},
+    {:is_map_key, 2} => {[:dynamic, {:map, [{:optional, :dynamic, :dynamic}]}], :dynamic},
+    {:is_number, 1} => {[@number], @boolean},
+    {:is_pid, 1} => {[:pid], @boolean},
+    {:is_port, 1} => {[:port], @boolean},
+    {:is_reference, 1} => {[:reference], @boolean},
+    {:is_tuple, 1} => {[:tuple], @boolean},
+    {:<, 2} => {[:dynamic, :dynamic], @boolean},
+    {:"=<", 2} => {[:dynamic, :dynamic], @boolean},
+    {:>, 2} => {[:dynamic, :dynamic], @boolean},
+    {:>=, 2} => {[:dynamic, :dynamic], @boolean},
+    {:"/=", 2} => {[:dynamic, :dynamic], @boolean},
+    {:"=/=", 2} => {[:dynamic, :dynamic], @boolean},
+    {:==, 2} => {[:dynamic, :dynamic], @boolean},
+    {:"=:=", 2} => {[:dynamic, :dynamic], @boolean},
+    {:*, 2} => {[@number, @number], @number},
+    {:+, 1} => {[@number], @number},
+    {:+, 2} => {[@number, @number], @number},
+    {:-, 1} => {[@number], @number},
+    {:-, 2} => {[@number, @number], @number},
+    {:/, 2} => {[@number, @number], @number},
+    {:abs, 1} => {[@number], @number},
+    {:ceil, 1} => {[@number], :integer},
+    {:floor, 1} => {[@number], :integer},
+    {:round, 1} => {[@number], :integer},
+    {:trunc, 1} => {[@number], :integer},
+    {:element, 2} => {[:integer, :tuple], :dynamic},
+    {:hd, 1} => {[{:list, :dynamic}], :dynamic},
+    {:length, 1} => {[{:list, :dynamic}], :integer},
+    {:map_get, 2} => {[:dynamic, {:map, [{:optional, :dynamic, :dynamic}]}], :dynamic},
+    {:map_size, 1} => {[{:map, [{:optional, :dynamic, :dynamic}]}], :integer},
+    {:tl, 1} => {[{:list, :dynamic}], :dynamic},
+    {:tuple_size, 1} => {[:tuple], :integer},
+    {:node, 1} => {[{:union, [:pid, :reference, :port]}], :atom},
+    {:binary_part, 3} => {[:binary, :integer, :integer], :binary},
+    {:bit_size, 1} => {[:binary], :integer},
+    {:byte_size, 1} => {[:binary], :integer},
+    {:size, 1} => {[{:union, [:binary, :tuple]}], @boolean},
+    {:div, 2} => {[:integer, :integer], :integer},
+    {:rem, 2} => {[:integer, :integer], :integer},
+    {:node, 0} => {[], :atom},
+    {:self, 0} => {[], :pid},
+    {:bnot, 1} => {[:integer], :integer},
+    {:band, 2} => {[:integer, :integer], :integer},
+    {:bor, 2} => {[:integer, :integer], :integer},
+    {:bxor, 2} => {[:integer, :integer], :integer},
+    {:bsl, 2} => {[:integer, :integer], :integer},
+    {:bsr, 2} => {[:integer, :integer], :integer},
+    {:or, 2} => {[@boolean, @boolean], @boolean},
+    {:and, 2} => {[@boolean, @boolean], @boolean},
+    {:xor, 2} => {[@boolean, @boolean], @boolean},
+    {:not, 1} => {[@boolean], @boolean}
 
     # Following guards are matched explicitly to handle
     # type guard functions such as is_atom/1
@@ -169,6 +163,7 @@ defmodule Module.Types.Pattern do
     :is_boolean,
     :is_float,
     :is_function,
+    :is_function,
     :is_integer,
     :is_list,
     :is_map,
@@ -183,27 +178,26 @@ defmodule Module.Types.Pattern do
   Refines the type variables in the typing context using type check guards
   such as `is_integer/1`.
   """
-  def of_guard(expr, expected, %{context: stack_context} = stack, context)
-      when stack_context != :pattern do
-    of_guard(expr, expected, %{stack | context: :pattern}, context)
+  def of_guard(expr, %{context: stack_context} = stack, context) when stack_context != :pattern do
+    of_guard(expr, %{stack | context: :pattern}, context)
   end
 
-  def of_guard({{:., _, [:erlang, :andalso]}, _, [left, right]} = expr, _expected, stack, context) do
+  def of_guard({{:., _, [:erlang, :andalso]}, _, [left, right]} = expr, stack, context) do
     stack = push_expr_stack(expr, stack)
 
-    with {:ok, left_type, context} <- of_guard(left, @boolean, stack, context),
+    with {:ok, left_type, context} <- of_guard(left, stack, context),
          {:ok, _, context} <- unify(left_type, @boolean, stack, context),
-         {:ok, right_type, context} <- of_guard(right, :dynamic, keep_guarded(stack), context),
+         {:ok, right_type, context} <- of_guard(right, keep_guarded(stack), context),
          do: {:ok, to_union([@boolean, right_type], context), context}
   end
 
-  def of_guard({{:., _, [:erlang, :orelse]}, _, [left, right]} = expr, _expected, stack, context) do
+  def of_guard({{:., _, [:erlang, :orelse]}, _, [left, right]} = expr, stack, context) do
     stack = push_expr_stack(expr, stack)
     left_indexes = collect_var_indexes_from_expr(left, context)
     right_indexes = collect_var_indexes_from_expr(right, context)
 
-    with {:ok, left_type, left_context} <- of_guard(left, @boolean, stack, context),
-         {:ok, _right_type, right_context} <- of_guard(right, :dynamic, stack, context),
+    with {:ok, left_type, left_context} <- of_guard(left, stack, context),
+         {:ok, _right_type, right_context} <- of_guard(right, stack, context),
          context =
            merge_context_or(
              left_indexes,
@@ -220,147 +214,71 @@ defmodule Module.Types.Pattern do
   # The unary operators + and - are special cased to avoid common warnings until
   # we add support for intersection types for the guard functions
   # -integer / +integer
-  def of_guard({{:., _, [:erlang, guard]}, _, [integer]}, _expected, _stack, context)
+  def of_guard({{:., _, [:erlang, guard]}, _, [integer]}, _stack, context)
       when guard in [:+, :-] and is_integer(integer) do
     {:ok, :integer, context}
   end
 
   # -float / +float
-  def of_guard({{:., _, [:erlang, guard]}, _, [float]}, _expected, _stack, context)
+  def of_guard({{:., _, [:erlang, guard]}, _, [float]}, _stack, context)
       when guard in [:+, :-] and is_float(float) do
     {:ok, :float, context}
   end
 
-  # tuple_size(arg) == integer
-  def of_guard(
-        {{:., _, [:erlang, :==]}, _, [{{:., _, [:erlang, :tuple_size]}, _, [var]}, size]} = expr,
-        expected,
-        stack,
-        context
-      )
-      when is_var(var) and is_integer(size) do
-    of_tuple_size(var, size, expr, expected, stack, context)
-  end
-
-  # integer == tuple_size(arg)
-  def of_guard(
-        {{:., _, [:erlang, :==]}, _, [size, {{:., _, [:erlang, :tuple_size]}, _, [var]}]} = expr,
-        expected,
-        stack,
-        context
-      )
-      when is_var(var) and is_integer(size) do
-    of_tuple_size(var, size, expr, expected, stack, context)
-  end
-
   # fun(args)
-  def of_guard({{:., _, [:erlang, guard]}, _, args} = expr, expected, stack, context) do
+  def of_guard({{:., _, [:erlang, guard]}, _, args} = expr, stack, context) do
+    stack = push_expr_stack(expr, stack)
+    {param_types, return_type} = guard_signature(guard, length(args))
     type_guard? = type_guard?(guard)
     {consider_type_guards?, keep_guarded?} = stack.type_guards
-    signature = guard_signature(guard, length(args))
 
     # Only check type guards in the context of and/or/not,
     # a type guard in the context of is_tuple(x) > :foo
     # should not affect the inference of x
     if not type_guard? or consider_type_guards? do
-      stack = push_expr_stack(expr, stack)
-      expected_clauses = filter_clauses(signature, expected, stack, context)
-      param_unions = signature_to_param_unions(expected_clauses, context)
       arg_stack = %{stack | type_guards: {false, keep_guarded?}}
-      mfa = {:erlang, guard, length(args)}
 
       with {:ok, arg_types, context} <-
-             map_reduce_ok(Enum.zip(args, param_unions), context, fn {arg, param}, context ->
-               of_guard(arg, param, arg_stack, context)
-             end),
-           {:ok, return_type, context} <-
-             unify_call(
-               arg_types,
-               expected_clauses,
-               expected,
-               mfa,
-               signature,
-               stack,
-               context,
-               type_guard?
-             ) do
-        guard_sources = guard_sources(arg_types, type_guard?, keep_guarded?, context)
+             map_reduce_ok(args, context, &of_guard(&1, arg_stack, &2)),
+           {:ok, context} <- unify_call(arg_types, param_types, stack, context) do
+        {arg_types, guard_sources} =
+          case arg_types do
+            [{:var, index} | rest_arg_types] when type_guard? ->
+              guard_sources = Map.put_new(context.guard_sources, index, :guarded)
+              {rest_arg_types, guard_sources}
+
+            _ ->
+              {arg_types, context.guard_sources}
+          end
+
+        guard_sources =
+          Enum.reduce(arg_types, guard_sources, fn
+            {:var, index}, guard_sources ->
+              Map.update(guard_sources, index, :fail, &guarded_if_keep_guarded(&1, keep_guarded?))
+
+            _, guard_sources ->
+              guard_sources
+          end)
+
         {:ok, return_type, %{context | guard_sources: guard_sources}}
       end
     else
-      # Assume that type guards always return boolean
-      boolean = {:union, [atom: true, atom: false]}
-      [{_params, ^boolean}] = signature
-      {:ok, boolean, context}
+      {:ok, return_type, context}
     end
   end
 
   # map.field
-  def of_guard({{:., meta1, [map, field]}, meta2, []}, expected, stack, context) do
-    of_guard({{:., meta1, [:erlang, :map_get]}, meta2, [field, map]}, expected, stack, context)
+  def of_guard({{:., meta1, [map, field]}, meta2, []}, stack, context) do
+    of_guard({{:., meta1, [:erlang, :map_get]}, meta2, [field, map]}, stack, context)
   end
 
   # var
-  def of_guard(var, _expected, _stack, context) when is_var(var) do
+  def of_guard(var, _stack, context) when is_var(var) do
     {:ok, get_var!(var, context), context}
   end
 
-  def of_guard(expr, _expected, stack, context) do
-    of_shared(expr, stack, context, &of_guard(&1, :dynamic, &2, &3))
-  end
-
-  defp of_tuple_size(var, size, expr, _expected, stack, context) do
-    {consider_type_guards?, _keep_guarded?} = stack.type_guards
-
-    result =
-      if consider_type_guards? do
-        stack = push_expr_stack(expr, stack)
-        tuple_elems = Enum.map(1..size//1, fn _ -> :dynamic end)
-
-        with {:ok, type, context} <- of_guard(var, :dynamic, stack, context),
-             {:ok, _type, context} <- unify({:tuple, size, tuple_elems}, type, stack, context),
-             do: {:ok, context}
-      else
-        {:ok, context}
-      end
-
-    case result do
-      {:ok, context} ->
-        boolean = {:union, [atom: true, atom: false]}
-        {:ok, boolean, context}
-
-      {:error, reason} ->
-        {:error, reason}
-    end
-  end
-
-  defp signature_to_param_unions(signature, context) do
-    signature
-    |> Enum.map(fn {params, _return} -> params end)
-    |> zip_many()
-    |> Enum.map(&to_union(&1, context))
-  end
-
-  # Collect guard sources from argument types, see type context documentation
-  # for more information
-  defp guard_sources(arg_types, type_guard?, keep_guarded?, context) do
-    {arg_types, guard_sources} =
-      case arg_types do
-        [{:var, index} | rest_arg_types] when type_guard? ->
-          guard_sources = Map.put_new(context.guard_sources, index, :guarded)
-          {rest_arg_types, guard_sources}
-
-        _ ->
-          {arg_types, context.guard_sources}
-      end
-
-    Enum.reduce(arg_types, guard_sources, fn
-      {:var, index}, guard_sources ->
-        Map.update(guard_sources, index, :fail, &guarded_if_keep_guarded(&1, keep_guarded?))
-
-      _, guard_sources ->
-        guard_sources
-    end)
+  def of_guard(expr, stack, context) do
+    of_shared(expr, stack, context, &of_guard/3)
   end
 
   defp collect_var_indexes_from_expr(expr, context) do
@@ -378,162 +296,15 @@ defmodule Module.Types.Pattern do
     Map.keys(vars)
   end
 
-  defp unify_call(args, clauses, _expected, _mfa, _signature, stack, context, true = _type_guard?) do
-    unify_type_guard_call(args, clauses, stack, context)
-  end
-
-  defp unify_call(args, clauses, expected, mfa, signature, stack, context, false = _type_guard?) do
-    unify_call(args, clauses, expected, mfa, signature, stack, context)
-  end
-
-  defp unify_call([], [{[], return}], _expected, _mfa, _signature, _stack, context) do
-    {:ok, return, context}
-  end
-
-  defp unify_call(args, clauses, expected, mfa, signature, stack, context) do
-    # Given the arguments:
-    # foo | bar, {:ok, baz | bat}
-
-    # Expand unions in arguments:
-    # foo | bar, {:ok, baz} | {:ok, bat}
-
-    # Permute arguments:
-    # foo, {:ok, baz}
-    # foo, {:ok, bat}
-    # bar, {:ok, baz}
-    # bar, {:ok, bat}
-
-    flatten_args = Enum.map(args, &flatten_union(&1, context))
-    cartesian_args = cartesian_product(flatten_args)
-
-    # Remove clauses that do not match the expected type
-    # Ignore type variables in parameters by changing them to dynamic
-
-    clauses =
-      clauses
-      |> filter_clauses(expected, stack, context)
-      |> Enum.map(fn {params, return} ->
-        {Enum.map(params, &var_to_dynamic/1), return}
-      end)
-
-    # For each permuted argument find the clauses they match
-    # All arguments must match at least one clause, but all clauses
-    # do not need to match
-    # Collect the return values from clauses that matched and collect
-    # the type contexts from unifying argument and parameter to
-    # infer type variables in arguments
-    result =
-      flat_map_ok(cartesian_args, fn cartesian_args ->
-        result =
-          Enum.flat_map(clauses, fn {params, return} ->
-            result =
-              map_ok(Enum.zip(cartesian_args, params), fn {arg, param} ->
-                case unify(arg, param, stack, context) do
-                  {:ok, _type, context} -> {:ok, context}
-                  {:error, reason} -> {:error, reason}
-                end
-              end)
-
-            case result do
-              {:ok, contexts} -> [{return, contexts}]
-              {:error, _reason} -> []
-            end
-          end)
-
-        if result != [] do
-          {:ok, result}
-        else
-          {:error, args}
-        end
-      end)
-
-    case result do
-      {:ok, returns_contexts} ->
-        {success_returns, contexts} = Enum.unzip(returns_contexts)
-        contexts = Enum.concat(contexts)
-
-        indexes =
-          for types <- flatten_args,
-              type <- types,
-              index <- collect_var_indexes_from_type(type),
-              do: index,
-              uniq: true
-
-        # Build unions from collected type contexts to unify with
-        # type variables from arguments
-        result =
-          map_reduce_ok(indexes, context, fn index, context ->
-            union =
-              contexts
-              |> Enum.map(&Map.fetch!(&1.types, index))
-              |> Enum.reject(&(&1 == :unbound))
-
-            if union == [] do
-              {:ok, {:var, index}, context}
-            else
-              unify({:var, index}, to_union(union, context), stack, context)
-            end
-          end)
-
-        case result do
-          {:ok, _types, context} -> {:ok, to_union(success_returns, context), context}
-          {:error, reason} -> {:error, reason}
-        end
-
-      {:error, args} ->
-        error(:unable_apply, {mfa, args, expected, signature, stack}, context)
-    end
-  end
-
-  defp unify_type_guard_call(args, [{params, return}], stack, context) do
-    result =
-      reduce_ok(Enum.zip(args, params), context, fn {arg, param}, context ->
-        case unify(arg, param, stack, context) do
-          {:ok, _, context} -> {:ok, context}
-          {:error, reason} -> {:error, reason}
-        end
-      end)
-
-    case result do
-      {:ok, context} -> {:ok, return, context}
-      {:error, reason} -> {:error, reason}
-    end
-  end
-
-  defp cartesian_product(lists) do
-    List.foldr(lists, [[]], fn list, acc ->
-      for elem_list <- list,
-          list_acc <- acc,
-          do: [elem_list | list_acc]
+  defp unify_call(args, params, stack, context) do
+    reduce_ok(Enum.zip(args, params), context, fn {arg, param}, context ->
+      case unify(arg, param, stack, context) do
+        {:ok, _, context} -> {:ok, context}
+        {:error, reason} -> {:error, reason}
+      end
     end)
   end
 
-  defp var_to_dynamic(type) do
-    {type, _acc} =
-      walk(type, :ok, fn
-        {:var, _index}, :ok ->
-          {:dynamic, :ok}
-
-        other, :ok ->
-          {other, :ok}
-      end)
-
-    type
-  end
-
-  defp collect_var_indexes_from_type(type) do
-    {_type, indexes} =
-      walk(type, [], fn
-        {:var, index}, indexes ->
-          {{:var, index}, [index | indexes]}
-
-        other, indexes ->
-          {other, indexes}
-      end)
-
-    indexes
-  end
-
   defp merge_context_or(left_indexes, right_indexes, context, stack, left, right) do
     left_different = filter_different_indexes(left_indexes, left, right)
     right_different = filter_different_indexes(right_indexes, left, right)
@@ -605,21 +376,13 @@ defmodule Module.Types.Pattern do
   defp keep_guarded(%{type_guards: {consider?, _}} = stack),
     do: %{stack | type_guards: {consider?, true}}
 
-  defp filter_clauses(signature, expected, stack, context) do
-    Enum.filter(signature, fn {_params, return} ->
-      match?({:ok, _type, _context}, unify(return, expected, stack, context))
-    end)
+  defp guard_signature(name, arity) do
+    Map.fetch!(@guard_functions, {name, arity})
   end
 
-  Enum.each(@guard_functions, fn {{name, arity}, signature} ->
-    defp guard_signature(unquote(name), unquote(arity)), do: unquote(Macro.escape(signature))
-  end)
-
-  Enum.each(@type_guards, fn name ->
-    defp type_guard?(unquote(name)), do: true
-  end)
-
-  defp type_guard?(name) when is_atom(name), do: false
+  defp type_guard?(name) do
+    name in @type_guards
+  end
 
   ## Shared
 

lib/elixir/lib/module/types/unify.ex

@@ -10,7 +10,6 @@ defmodule Module.Types.Unify do
   #   {:atom, atom} < :atom
   #   :integer
   #   :float
-  #   :binary
   #   :pid
   #   :port
   #   :reference
@@ -21,37 +20,55 @@ defmodule Module.Types.Unify do
   #   {:tuple, size, [type]} < :tuple
   #   {:union, [type]}
   #   {:map, [{:required | :optional, key_type, value_type}]}
-  #   {:fun, [{params, return}]}
   #
   # Once new types are added, they should be considered in:
   #
   #   * unify (all)
   #   * format_type (all)
   #   * subtype? (subtypes only)
+  #   * has_unbound_var? (composite only)
   #   * recursive_type? (composite only)
-  #   * collect_var_indexes (composite only)
+  #   * collect_vars (composite only)
   #   * lift_types (composite only)
-  #   * flatten_union (composite only)
-  #   * walk (composite only)
   #
 
   @doc """
   Unifies two types and returns the unified type and an updated typing context
   or an error in case of a typing conflict.
   """
-  def unify(same, same, _stack, context) do
+  def unify(source, target, stack, context) do
+    case do_unify(source, target, stack, context) do
+      {:ok, type, context} ->
+        {:ok, type, context}
+
+      {:error, reason} ->
+        if stack.context == :pattern do
+          case do_unify(target, source, stack, context) do
+            {:ok, type, context} ->
+              {:ok, type, context}
+
+            {:error, _} ->
+              {:error, reason}
+          end
+        else
+          {:error, reason}
+        end
+    end
+  end
+
+  defp do_unify(same, same, _stack, context) do
     {:ok, same, context}
   end
 
-  def unify({:var, var}, type, stack, context) do
-    unify_var(var, type, stack, context, _var_source = true)
-  end
-
-  def unify(type, {:var, var}, stack, context) do
+  defp do_unify(type, {:var, var}, stack, context) do
     unify_var(var, type, stack, context, _var_source = false)
   end
 
-  def unify({:tuple, n, sources}, {:tuple, n, targets}, stack, context) do
+  defp do_unify({:var, var}, type, stack, context) do
+    unify_var(var, type, stack, context, _var_source = true)
+  end
+
+  defp do_unify({:tuple, n, sources}, {:tuple, n, targets}, stack, context) do
     result =
       map_reduce_ok(Enum.zip(sources, targets), context, fn {source, target}, context ->
         unify(source, target, stack, context)
@@ -63,26 +80,26 @@ defmodule Module.Types.Unify do
     end
   end
 
-  def unify({:list, source}, {:list, target}, stack, context) do
+  defp do_unify({:list, source}, {:list, target}, stack, context) do
     case unify(source, target, stack, context) do
       {:ok, type, context} -> {:ok, {:list, type}, context}
       {:error, reason} -> {:error, reason}
     end
   end
 
-  def unify({:map, source_pairs}, {:map, target_pairs}, stack, context) do
+  defp do_unify({:map, source_pairs}, {:map, target_pairs}, stack, context) do
     unify_maps(source_pairs, target_pairs, stack, context)
   end
 
-  def unify(source, :dynamic, _stack, context) do
+  defp do_unify(source, :dynamic, _stack, context) do
     {:ok, source, context}
   end
 
-  def unify(:dynamic, target, _stack, context) do
+  defp do_unify(:dynamic, target, _stack, context) do
     {:ok, target, context}
   end
 
-  def unify({:union, types}, target, stack, context) do
+  defp do_unify({:union, types}, target, stack, context) do
     unify_result =
       map_reduce_ok(types, context, fn type, context ->
         unify(type, target, stack, context)
@@ -94,7 +111,7 @@ defmodule Module.Types.Unify do
     end
   end
 
-  def unify(source, target, stack, context) do
+  defp do_unify(source, target, stack, context) do
     cond do
       # TODO: This condition exists to handle unions with unbound vars.
       match?({:union, _}, target) and has_unbound_var?(target, context) ->
@@ -108,11 +125,11 @@ defmodule Module.Types.Unify do
     end
   end
 
-  def unify_var(var, :dynamic, _stack, context, _var_source?) do
+  defp unify_var(var, :dynamic, _stack, context, _var_source?) do
     {:ok, {:var, var}, context}
   end
 
-  def unify_var(var, type, stack, context, var_source?) do
+  defp unify_var(var, type, stack, context, var_source?) do
     case context.types do
       %{^var => :unbound} ->
         context = refine_var!(var, type, stack, context)
@@ -128,10 +145,30 @@ defmodule Module.Types.Unify do
           {:ok, {:var, var}, context}
         end
 
-      %{^var => {:var, _} = var_type} ->
-        # Do not recursively traverse type vars for now
-        # to avoid pathological cases related to performance.
-        {:ok, var_type, context}
+      %{^var => {:var, new_var} = var_type} ->
+        unify_result =
+          if var_source? do
+            unify(var_type, type, stack, context)
+          else
+            unify(type, var_type, stack, context)
+          end
+
+        case unify_result do
+          {:ok, type, context} ->
+            {:ok, type, context}
+
+          {:error, {type, reason, %{traces: error_traces} = error_context}} ->
+            old_var_traces = Map.get(context.traces, new_var, [])
+            new_var_traces = Map.get(error_traces, new_var, [])
+            add_var_traces = Enum.drop(new_var_traces, -length(old_var_traces))
+
+            error_traces =
+              error_traces
+              |> Map.update(var, add_var_traces, &(add_var_traces ++ &1))
+              |> Map.put(new_var, old_var_traces)
+
+            {:error, {type, reason, %{error_context | traces: error_traces}}}
+        end
 
       %{^var => var_type} ->
         # Only add trace if the variable wasn't already "expanded"
@@ -168,7 +205,7 @@ defmodule Module.Types.Unify do
   # * All required keys on each side need to match to the other side.
   # * All optional keys on each side that do not match must be discarded.
 
-  def unify_maps(source_pairs, target_pairs, stack, context) do
+  defp unify_maps(source_pairs, target_pairs, stack, context) do
     {source_required, source_optional} = split_pairs(source_pairs)
     {target_required, target_optional} = split_pairs(target_pairs)
 
@@ -199,7 +236,7 @@ defmodule Module.Types.Unify do
     end
   end
 
-  def unify_source_required(source_required, target_pairs, stack, context) do
+  defp unify_source_required(source_required, target_pairs, stack, context) do
     map_reduce_ok(source_required, context, fn {source_key, source_value}, context ->
       Enum.find_value(target_pairs, fn {target_kind, target_key, target_value} ->
         with {:ok, key, context} <- unify(source_key, target_key, stack, context) do
@@ -219,7 +256,7 @@ defmodule Module.Types.Unify do
     end)
   end
 
-  def unify_target_required(target_required, source_pairs, stack, context) do
+  defp unify_target_required(target_required, source_pairs, stack, context) do
     map_reduce_ok(target_required, context, fn {target_key, target_value}, context ->
       Enum.find_value(source_pairs, fn {source_kind, source_key, source_value} ->
         with {:ok, key, context} <- unify(source_key, target_key, stack, context) do
@@ -239,7 +276,7 @@ defmodule Module.Types.Unify do
     end)
   end
 
-  def unify_source_optional(source_optional, target_optional, stack, context) do
+  defp unify_source_optional(source_optional, target_optional, stack, context) do
     flat_map_reduce_ok(source_optional, context, fn {source_key, source_value}, context ->
       Enum.find_value(target_optional, fn {target_key, target_value} ->
         with {:ok, key, context} <- unify(source_key, target_key, stack, context) do
@@ -259,7 +296,7 @@ defmodule Module.Types.Unify do
     end)
   end
 
-  def unify_target_optional(target_optional, source_optional, stack, context) do
+  defp unify_target_optional(target_optional, source_optional, stack, context) do
     flat_map_reduce_ok(target_optional, context, fn {target_key, target_value}, context ->
       Enum.find_value(source_optional, fn {source_key, source_value} ->
         with {:ok, key, context} <- unify(source_key, target_key, stack, context) do
@@ -288,7 +325,7 @@ defmodule Module.Types.Unify do
     {required, optional}
   end
 
-  def error(type, reason, context), do: {:error, {type, reason, context}}
+  defp error(type, reason, context), do: {:error, {type, reason, context}}
 
   @doc """
   Push expression to stack.
@@ -359,11 +396,11 @@ defmodule Module.Types.Unify do
   end
 
   @doc """
-  Maybe resolves a variable.
+  Resolves a variable raising if it is unbound.
   """
   def resolve_var({:var, var}, context) do
     case context.types do
-      %{^var => :unbound} -> {:var, var}
+      %{^var => :unbound} -> raise "cannot resolve unbound var"
       %{^var => type} -> resolve_var(type, context)
     end
   end
@@ -468,12 +505,6 @@ defmodule Module.Types.Unify do
     end)
   end
 
-  defp recursive_type?({:fun, clauses}, parents, context) do
-    Enum.any?(clauses, fn {args, return} ->
-      Enum.any?([return | args], &recursive_type?(&1, [clauses | parents], context))
-    end)
-  end
-
   defp recursive_type?(_other, _parents, _context) do
     false
   end
@@ -481,55 +512,65 @@ defmodule Module.Types.Unify do
   @doc """
   Collects all type vars recursively.
   """
-  def collect_var_indexes(type, context, acc \\ %{}) do
-    {_type, indexes} =
-      walk(type, acc, fn
-        {:var, var}, acc ->
-          case acc do
-            %{^var => _} ->
-              {{:var, var}, acc}
+  def collect_var_indexes(type, context, acc \\ %{})
 
-            %{} ->
-              case context.types do
-                %{^var => :unbound} ->
-                  {{:var, var}, Map.put(acc, var, true)}
+  def collect_var_indexes({:var, var}, context, acc) do
+    case acc do
+      %{^var => _} ->
+        acc
 
-                %{^var => type} ->
-                  {{:var, var}, collect_var_indexes(type, context, Map.put(acc, var, true))}
-              end
-          end
-
-        other, acc ->
-          {other, acc}
-      end)
-
-    indexes
+      %{} ->
+        case context.types do
+          %{^var => :unbound} -> Map.put(acc, var, true)
+          %{^var => type} -> collect_var_indexes(type, context, Map.put(acc, var, true))
+        end
+    end
   end
 
+  def collect_var_indexes({:tuple, _, args}, context, acc),
+    do: Enum.reduce(args, acc, &collect_var_indexes(&1, context, &2))
+
+  def collect_var_indexes({:union, args}, context, acc),
+    do: Enum.reduce(args, acc, &collect_var_indexes(&1, context, &2))
+
+  def collect_var_indexes({:list, arg}, context, acc),
+    do: collect_var_indexes(arg, context, acc)
+
+  def collect_var_indexes({:map, pairs}, context, acc) do
+    Enum.reduce(pairs, acc, fn {_, key, value}, acc ->
+      collect_var_indexes(value, context, collect_var_indexes(key, context, acc))
+    end)
+  end
+
+  def collect_var_indexes(_type, _context, acc), do: acc
+
   @doc """
   Checks if the type has a type var.
   """
-  def has_unbound_var?(type, context) do
-    walk(type, :ok, fn
-      {:var, var}, acc ->
-        case context.types do
-          %{^var => :unbound} ->
-            throw(:has_unbound_var?)
-
-          %{^var => type} ->
-            has_unbound_var?(type, context)
-            {{:var, var}, acc}
-        end
-
-      other, acc ->
-        {other, acc}
-    end)
-
-    false
-  catch
-    :throw, :has_unbound_var? -> true
+  def has_unbound_var?({:var, var}, context) do
+    case context.types do
+      %{^var => :unbound} -> true
+      %{^var => type} -> has_unbound_var?(type, context)
+    end
   end
 
+  def has_unbound_var?({:tuple, _, args}, context),
+    do: Enum.any?(args, &has_unbound_var?(&1, context))
+
+  def has_unbound_var?({:union, args}, context),
+    do: Enum.any?(args, &has_unbound_var?(&1, context))
+
+  def has_unbound_var?({:list, arg}, context),
+    do: has_unbound_var?(arg, context)
+
+  def has_unbound_var?({:map, pairs}, context) do
+    Enum.any?(pairs, fn {_, key, value} ->
+      has_unbound_var?(key, context) or has_unbound_var?(value, context)
+    end)
+  end
+
+  def has_unbound_var?(_type, _context), do: false
+
   @doc """
   Returns true if it is a singleton type.
 
@@ -628,15 +669,17 @@ defmodule Module.Types.Unify do
   def to_union([type], _context), do: type
 
   def to_union(types, context) when types != [] do
-    case unique_super_types(unnest_unions(types), context) do
+    flat_types = flatten_union(types)
+
+    case unique_super_types(flat_types, context) do
       [type] -> type
       types -> {:union, types}
     end
   end
 
-  defp unnest_unions(types) do
+  defp flatten_union(types) do
     Enum.flat_map(types, fn
-      {:union, types} -> unnest_unions(types)
+      {:union, types} -> flatten_union(types)
       type -> [type]
     end)
   end
@@ -666,10 +709,6 @@ defmodule Module.Types.Unify do
   @doc """
   Lifts type variables to their inferred types from the context.
   """
-  def lift_types(types, %{lifted_types: _} = context) do
-    Enum.map_reduce(types, context, &lift_type/2)
-  end
-
   def lift_types(types, context) do
     context = %{
       types: context.types,
@@ -677,7 +716,8 @@ defmodule Module.Types.Unify do
       lifted_counter: 0
     }
 
-    Enum.map_reduce(types, context, &lift_type/2)
+    {types, _context} = Enum.map_reduce(types, context, &lift_type/2)
+    types
   end
 
   # Lift type variable to its inferred (hopefully concrete) types from the context
@@ -735,16 +775,6 @@ defmodule Module.Types.Unify do
     {{:list, type}, context}
   end
 
-  defp lift_type({:fun, clauses}, context) do
-    clauses =
-      Enum.map_reduce(clauses, context, fn {args, return}, context ->
-        {[return | args], context} = Enum.map_reduce([return | args], context, &lift_type/2)
-        {{args, return}, context}
-      end)
-
-    {{:fun, clauses}, context}
-  end
-
   defp lift_type(other, context) do
     {other, context}
   end
@@ -758,107 +788,6 @@ defmodule Module.Types.Unify do
     {type, context}
   end
 
-  # TODO: Figure out function expansion
-
-  @doc """
-  Expand unions so that all unions are at the top level.
-
-      {integer() | float()} => {integer()} | {float()}
-  """
-  def flatten_union({:union, types}, context) do
-    Enum.flat_map(types, &flatten_union(&1, context))
-  end
-
-  def flatten_union(type, context) do
-    List.wrap(do_flatten_union(type, context))
-  end
-
-  def do_flatten_union({:tuple, num, types}, context) do
-    flatten_union_tuple(types, num, context, [])
-  end
-
-  def do_flatten_union({:list, type}, context) do
-    case do_flatten_union(type, context) do
-      {:union, union_types} -> Enum.map(union_types, &{:list, &1})
-      _type -> [{:list, type}]
-    end
-  end
-
-  def do_flatten_union({:map, pairs}, context) do
-    flatten_union_map(pairs, context, [])
-  end
-
-  def do_flatten_union({:var, var}, context) do
-    if looping_var?(var, context, []) do
-      {:var, var}
-    else
-      case context.types do
-        %{^var => :unbound} -> {:var, var}
-        %{^var => {:union, types}} -> Enum.map(types, &do_flatten_union(&1, context))
-        %{^var => type} -> do_flatten_union(type, context)
-      end
-    end
-  end
-
-  def do_flatten_union(type, _context) do
-    type
-  end
-
-  defp flatten_union_tuple([type | types], num, context, acc) do
-    case do_flatten_union(type, context) do
-      {:union, union_types} ->
-        Enum.flat_map(union_types, &flatten_union_tuple(types, num, context, [&1 | acc]))
-
-      type ->
-        flatten_union_tuple(types, num, context, [type | acc])
-    end
-  end
-
-  defp flatten_union_tuple([], num, _context, acc) do
-    [{:tuple, num, Enum.reverse(acc)}]
-  end
-
-  defp flatten_union_map([{kind, key, value} | pairs], context, acc) do
-    case do_flatten_union(key, context) do
-      {:union, union_types} ->
-        Enum.flat_map(union_types, &flatten_union_map_value(kind, &1, value, pairs, context, acc))
-
-      type ->
-        flatten_union_map_value(kind, type, value, pairs, context, acc)
-    end
-  end
-
-  defp flatten_union_map([], _context, acc) do
-    [{:map, Enum.reverse(acc)}]
-  end
-
-  defp flatten_union_map_value(kind, key, value, pairs, context, acc) do
-    case do_flatten_union(value, context) do
-      {:union, union_types} ->
-        Enum.flat_map(union_types, &flatten_union_map(pairs, context, [{kind, key, &1} | acc]))
-
-      value ->
-        flatten_union_map(pairs, context, [{kind, key, value} | acc])
-    end
-  end
-
-  defp looping_var?(var, context, parents) do
-    case context.types do
-      %{^var => :unbound} ->
-        false
-
-      %{^var => {:var, type}} ->
-        if var in parents do
-          true
-        else
-          looping_var?(type, context, [var | parents])
-        end
-
-      %{^var => _type} ->
-        false
-    end
-  end
-
   @doc """
   Formats types.
 
@@ -868,7 +797,7 @@ defmodule Module.Types.Unify do
   def format_type({:map, pairs}, true) do
     case List.keyfind(pairs, {:atom, :__struct__}, 1) do
       {:required, {:atom, :__struct__}, {:atom, struct}} ->
-        ["%", inspect(struct), "{}"]
+        "%#{inspect(struct)}{}"
 
       _ ->
         "map()"
@@ -876,31 +805,24 @@ defmodule Module.Types.Unify do
   end
 
   def format_type({:union, types}, simplify?) do
-    types
-    |> Enum.map(&format_type(&1, simplify?))
-    |> Enum.intersperse(" | ")
+    "#{Enum.map_join(types, " | ", &format_type(&1, simplify?))}"
   end
 
   def format_type({:tuple, _, types}, simplify?) do
-    format =
-      types
-      |> Enum.map(&format_type(&1, simplify?))
-      |> Enum.intersperse(", ")
-
-    ["{", format, "}"]
+    "{#{Enum.map_join(types, ", ", &format_type(&1, simplify?))}}"
   end
 
   def format_type({:list, type}, simplify?) do
-    ["[", format_type(type, simplify?), "]"]
+    "[#{format_type(type, simplify?)}]"
   end
 
   def format_type({:map, pairs}, false) do
     case List.keytake(pairs, {:atom, :__struct__}, 1) do
       {{:required, {:atom, :__struct__}, {:atom, struct}}, pairs} ->
-        ["%", inspect(struct), "{", format_map_pairs(pairs), "}"]
+        "%#{inspect(struct)}{#{format_map_pairs(pairs)}}"
 
       _ ->
-        ["%{", format_map_pairs(pairs), "}"]
+        "%{#{format_map_pairs(pairs)}}"
     end
   end
 
@@ -909,84 +831,26 @@ defmodule Module.Types.Unify do
   end
 
   def format_type({:var, index}, _simplify?) do
-    ["var", Integer.to_string(index + 1)]
-  end
-
-  def format_type({:fun, clauses}, simplify?) do
-    format =
-      Enum.map(clauses, fn {params, return} ->
-        params = Enum.intersperse(Enum.map(params, &format_type(&1, simplify?)), ", ")
-        params = if params == [], do: params, else: [params, " "]
-        return = format_type(return, simplify?)
-        [params, "-> ", return]
-      end)
-
-    ["(", Enum.intersperse(format, "; "), ")"]
+    "var#{index + 1}"
   end
 
   def format_type(atom, _simplify?) when is_atom(atom) do
-    [Atom.to_string(atom), "()"]
+    "#{atom}()"
   end
 
   defp format_map_pairs(pairs) do
     {atoms, others} = Enum.split_with(pairs, &match?({:required, {:atom, _}, _}, &1))
     {required, optional} = Enum.split_with(others, &match?({:required, _, _}, &1))
 
-    (atoms ++ required ++ optional)
-    |> Enum.map(fn
+    Enum.map_join(atoms ++ required ++ optional, ", ", fn
       {:required, {:atom, atom}, right} ->
-        [Atom.to_string(atom), ": ", format_type(right, false)]
+        "#{atom}: #{format_type(right, false)}"
 
       {:required, left, right} ->
-        [format_type(left, false), " => ", format_type(right, false)]
+        "#{format_type(left, false)} => #{format_type(right, false)}"
 
       {:optional, left, right} ->
-        ["optional(", format_type(left, false), ") => ", format_type(right, false)]
+        "optional(#{format_type(left, false)}) => #{format_type(right, false)}"
     end)
-    |> Enum.intersperse(", ")
-  end
-
-  @doc """
-  Performs a depth-first, pre-order traversal of the type tree using an accumulator.
-  """
-  def walk({:map, pairs}, acc, fun) do
-    {pairs, acc} =
-      Enum.map_reduce(pairs, acc, fn {kind, key, value}, acc ->
-        {key, acc} = walk(key, acc, fun)
-        {value, acc} = walk(value, acc, fun)
-        {{kind, key, value}, acc}
-      end)
-
-    fun.({:map, pairs}, acc)
-  end
-
-  def walk({:union, types}, acc, fun) do
-    {types, acc} = Enum.map_reduce(types, acc, &walk(&1, &2, fun))
-    fun.({:union, types}, acc)
-  end
-
-  def walk({:tuple, num, types}, acc, fun) do
-    {types, acc} = Enum.map_reduce(types, acc, &walk(&1, &2, fun))
-    fun.({:tuple, num, types}, acc)
-  end
-
-  def walk({:list, type}, acc, fun) do
-    {type, acc} = walk(type, acc, fun)
-    fun.({:list, type}, acc)
-  end
-
-  def walk({:fun, clauses}, acc, fun) do
-    {clauses, acc} =
-      Enum.map_reduce(clauses, acc, fn {params, return}, acc ->
-        {params, acc} = Enum.map_reduce(params, acc, &walk(&1, &2, fun))
-        {return, acc} = walk(return, acc, fun)
-        {{params, return}, acc}
-      end)
-
-    fun.({:fun, clauses}, acc)
-  end
-
-  def walk(type, acc, fun) do
-    fun.(type, acc)
   end
 end

lib/elixir/lib/node.ex

@@ -257,36 +257,6 @@ defmodule Node do
     :erlang.spawn_link(node, module, fun, args)
   end
 
-  @doc """
-  Spawns the given function on a node, monitors it and returns its PID
-  and monitoring reference.
-
-  This functionality was added on Erlang/OTP 23. Using this function to
-  communicate with nodes running on earlier versions will fail.
-
-  Inlined by the compiler.
-  """
-  @doc since: "1.14.0"
-  @spec spawn_monitor(t, (() -> any)) :: {pid, reference}
-  def spawn_monitor(node, fun) do
-    :erlang.spawn_monitor(node, fun)
-  end
-
-  @doc """
-  Spawns the given module and function passing the given args on a node,
-  monitors it and returns its PID and monitoring reference.
-
-  This functionality was added on Erlang/OTP 23. Using this function
-  to communicate with nodes running on earlier versions will fail.
-
-  Inlined by the compiler.
-  """
-  @doc since: "1.14.0"
-  @spec spawn_monitor(t, module, atom, [any]) :: {pid, reference}
-  def spawn_monitor(node, module, fun, args) do
-    :erlang.spawn_monitor(node, module, fun, args)
-  end
-
   @doc """
   Sets the magic cookie of `node` to the atom `cookie`.
 

lib/elixir/lib/option_parser.ex

@@ -29,12 +29,7 @@ defmodule OptionParser do
   @type argv :: [String.t()]
   @type parsed :: keyword
   @type errors :: [{String.t(), String.t() | nil}]
-  @type options :: [
-          switches: keyword,
-          strict: keyword,
-          aliases: keyword,
-          allow_nonexistent_atoms: boolean
-        ]
+  @type options :: [switches: keyword, strict: keyword, aliases: keyword]
 
   defmodule ParseError do
     defexception [:message]
@@ -492,7 +487,7 @@ defmodule OptionParser do
   Keys must be atoms. Keys with `nil` value are discarded,
   boolean values are converted to `--key` or `--no-key`
   (if the value is `true` or `false`, respectively),
-  and all other values are converted using `to_string/1`.
+  and all other values are converted using `Kernel.to_string/1`.
 
   It is advised to pass to `to_argv/2` the same set of `options`
   given to `parse/2`. Some switches can only be reconstructed
@@ -601,11 +596,9 @@ defmodule OptionParser do
           raise ArgumentError, ":switches and :strict cannot be given together"
 
         switches = opts[:switches] ->
-          validate_switches(switches)
           {switches, false}
 
         strict = opts[:strict] ->
-          validate_switches(strict)
           {strict, true}
 
         true ->
@@ -621,20 +614,6 @@ defmodule OptionParser do
     }
   end
 
-  defp validate_switches(switches) do
-    Enum.map(switches, &validate_switch/1)
-  end
-
-  defp validate_switch({_name, type_or_type_and_modifiers}) do
-    valid = [:boolean, :count, :integer, :float, :string, :keep]
-    invalid = List.wrap(type_or_type_and_modifiers) -- valid
-
-    if invalid != [] do
-      raise ArgumentError,
-            "invalid switch types/modifiers: " <> Enum.map_join(invalid, ", ", &inspect/1)
-    end
-  end
-
   defp validate_option(value, kinds) do
     {invalid?, value} =
       cond do
@@ -833,15 +812,7 @@ defmodule OptionParser do
     if type = get_type(option, opts, types) do
       "#{option} : Missing argument of type #{type}"
     else
-      msg = "#{option} : Unknown option"
-
-      case did_you_mean(option, types) do
-        {similar, score} when score > 0.8 ->
-          msg <> ". Did you mean --#{similar}?"
-
-        _ ->
-          msg
-      end
+      "#{option} : Unknown option"
     end
   end
 
@@ -860,17 +831,4 @@ defmodule OptionParser do
       types[key]
     end
   end
-
-  defp did_you_mean(option, types) do
-    key = option |> String.trim_leading("-") |> String.replace("-", "_")
-    Enum.reduce(types, {nil, 0}, &max_similar(&1, key, &2))
-  end
-
-  defp max_similar({source, _}, target, {_, current} = best) do
-    source = Atom.to_string(source)
-
-    score = String.jaro_distance(source, target)
-    option = String.replace(source, "_", "-")
-    if score < current, do: best, else: {option, score}
-  end
 end

lib/elixir/lib/partition_supervisor.ex

@@ -1,386 +0,0 @@
-defmodule PartitionSupervisor do
-  @moduledoc """
-  A supervisor that starts multiple partitions of the same child.
-
-  Certain processes may become bottlenecks in large systems.
-  If those processes can have their state trivially partitioned,
-  in a way there is no dependency between them, then they can use
-  the `PartitionSupervisor` to create multiple isolated and
-  independent partitions.
-
-  Once the `PartitionSupervisor` starts, you can dispatch to its
-  children using `{:via, PartitionSupervisor, {name, key}}`, where
-  `name` is the name of the `PartitionSupervisor` and key is used
-  for routing.
-
-  ## Example
-
-  The `DynamicSupervisor` is a single process responsible for starting
-  other processes. In some applications, the `DynamicSupervisor` may
-  become a bottleneck. To address this, you can start multiple instances
-  of the `DynamicSupervisor` through a `PartitionSupervisor`, and then
-  pick a "random" instance to start the child on.
-
-  Instead of starting a single `DynamicSupervisor`:
-
-      children = [
-        {DynamicSupervisor, name: MyApp.DynamicSupervisor}
-      ]
-
-      Supervisor.start_link(children, strategy: :one_for_one)
-
-  and starting children on that dynamic supervisor directly:
-
-      DynamicSupervisor.start_child(MyApp.DynamicSupervisor, {Agent, fn -> %{} end})
-
-  You can do start the dynamic supervisors under a `PartitionSupervisor`:
-
-      children = [
-        {PartitionSupervisor,
-         child_spec: DynamicSupervisor,
-         name: MyApp.DynamicSupervisors}
-      ]
-
-      Supervisor.start_link(children, strategy: :one_for_one)
-
-  and then:
-
-      DynamicSupervisor.start_child(
-        {:via, PartitionSupervisor, {MyApp.DynamicSupervisors, self()}},
-        {Agent, fn -> %{} end}
-      )
-
-  In the code above, we start a partition supervisor that will by default
-  start a dynamic supervisor for each core in your machine. Then, instead
-  of calling the `DynamicSupervisor` by name, you call it through the
-  partition supervisor using the `{:via, PartitionSupervisor, {name, key}}`
-  format. We picked `self()` as the routing key, which means each process
-  will be assigned one of the existing dynamic supervisors. See `start_link/1`
-  to see all options supported by the `PartitionSupervisor`.
-
-  ## Implementation notes
-
-  The `PartitionSupervisor` uses either an ETS table or a `Registry` to
-  manage all of the partitions. Under the hood, the `PartitionSupervisor`
-  generates a child spec for each partition and then acts as a regular
-  supervisor. The ID of each child spec is the partition number.
-
-  For routing, two strategies are used. If `key` is an integer, it is routed
-  using `rem(abs(key), partitions)` where `partitions` is the number of
-  partitions. Otherwise it uses `:erlang.phash2(key, partitions)`.
-  The particular routing may change in the future, and therefore must not
-  be relied on. If you want to retrieve a particular PID for a certain key,
-  you can use `GenServer.whereis({:via, PartitionSupervisor, {name, key}})`.
-  """
-
-  @behaviour Supervisor
-
-  @registry PartitionSupervisor.Registry
-
-  @typedoc """
-  The name of the `PartitionSupervisor`.
-  """
-  @type name :: atom() | {:via, module(), term()}
-
-  @doc false
-  def child_spec(opts) when is_list(opts) do
-    id =
-      case Keyword.get(opts, :name, DynamicSupervisor) do
-        name when is_atom(name) -> name
-        {:via, _module, name} -> name
-      end
-
-    %{
-      id: id,
-      start: {PartitionSupervisor, :start_link, [opts]},
-      type: :supervisor
-    }
-  end
-
-  @doc """
-  Starts a partition supervisor with the given options.
-
-  This function is typically not invoked directly, instead it is invoked
-  when using a `PartitionSupervisor` as a child of another supervisor:
-
-      children = [
-        {PartitionSupervisor, child_spec: SomeChild, name: MyPartitionSupervisor}
-      ]
-
-  If the supervisor is successfully spawned, this function returns
-  `{:ok, pid}`, where `pid` is the PID of the supervisor. If the given name
-  for the partition supervisor is already assigned to a process,
-  the function returns `{:error, {:already_started, pid}}`, where `pid`
-  is the PID of that process.
-
-  Note that a supervisor started with this function is linked to the parent
-  process and exits not only on crashes but also if the parent process exits
-  with `:normal` reason.
-
-  ## Options
-
-    * `:name` - an atom or via tuple representing the name of the partition
-      supervisor (see `t:name/0`).
-
-    * `:partitions` - a positive integer with the number of partitions.
-      Defaults to `System.schedulers_online()` (typically the number of cores).
-
-    * `:strategy` - the restart strategy option, defaults to `:one_for_one`.
-      You can learn more about strategies in the `Supervisor` module docs.
-
-    * `:max_restarts` - the maximum number of restarts allowed in
-      a time frame. Defaults to `3`.
-
-    * `:max_seconds` - the time frame in which `:max_restarts` applies.
-      Defaults to `5`.
-
-    * `:with_arguments` - a two-argument anonymous function that allows
-      the partition to be given to the child starting function. See the
-      `:with_arguments` section below.
-
-  ## `:with_arguments`
-
-  Sometimes you want each partition to know their partition assigned number.
-  This can be done with the `:with_arguments` option. This function receives
-  the list of arguments of the child specification and the partition. It
-  must return a new list of arguments that will be passed to the child specification
-  of children.
-
-  For example, most processes are started by calling `start_link(opts)`,
-  where `opts` is a keyword list. You could inject the partition into the
-  options given to the child:
-
-      with_arguments: fn [opts], partition ->
-        [Keyword.put(opts, :partition, partition)]
-      end
-
-  """
-  @doc since: "1.14.0"
-  @spec start_link(keyword) :: Supervisor.on_start()
-  def start_link(opts) when is_list(opts) do
-    name = opts[:name]
-
-    unless name do
-      raise ArgumentError, "the :name option must be given to PartitionSupervisor"
-    end
-
-    {child_spec, opts} = Keyword.pop(opts, :child_spec)
-
-    unless child_spec do
-      raise ArgumentError, "the :child_spec option must be given to PartitionSupervisor"
-    end
-
-    {partitions, opts} = Keyword.pop(opts, :partitions, System.schedulers_online())
-
-    unless is_integer(partitions) and partitions >= 1 do
-      raise ArgumentError,
-            "the :partitions option must be a positive integer, got: #{inspect(partitions)}"
-    end
-
-    {with_arguments, opts} = Keyword.pop(opts, :with_arguments, fn args, _partition -> args end)
-
-    unless is_function(with_arguments, 2) do
-      raise ArgumentError,
-            "the :with_arguments option must be a function that receives two arguments, " <>
-              "the current call arguments and the partition, got: #{inspect(with_arguments)}"
-    end
-
-    %{start: {mod, fun, args}} = map = Supervisor.child_spec(child_spec, [])
-    modules = map[:modules] || [mod]
-
-    children =
-      for partition <- 0..(partitions - 1) do
-        args = with_arguments.(args, partition)
-
-        unless is_list(args) do
-          raise "the call to the function in :with_arguments must return a list, got: #{inspect(args)}"
-        end
-
-        start = {__MODULE__, :start_child, [mod, fun, args, name, partition]}
-        Map.merge(map, %{id: partition, start: start, modules: modules})
-      end
-
-    {init_opts, start_opts} = Keyword.split(opts, [:strategy, :max_seconds, :max_restarts])
-    Supervisor.start_link(__MODULE__, {name, partitions, children, init_opts}, start_opts)
-  end
-
-  @doc false
-  def start_child(mod, fun, args, name, partition) do
-    case apply(mod, fun, args) do
-      {:ok, pid} ->
-        register_child(name, partition, pid)
-        {:ok, pid}
-
-      {:ok, pid, info} ->
-        register_child(name, partition, pid)
-        {:ok, pid, info}
-
-      other ->
-        other
-    end
-  end
-
-  defp register_child(name, partition, pid) when is_atom(name) do
-    :ets.insert(name, {partition, pid})
-  end
-
-  defp register_child({:via, _, _}, partition, pid) do
-    Registry.register(@registry, {self(), partition}, pid)
-  end
-
-  @impl true
-  def init({name, partitions, children, init_opts}) do
-    init_partitions(name, partitions)
-    Supervisor.init(children, Keyword.put_new(init_opts, :strategy, :one_for_one))
-  end
-
-  defp init_partitions(name, partitions) when is_atom(name) do
-    :ets.new(name, [:set, :named_table, :protected, read_concurrency: true])
-    :ets.insert(name, {:partitions, partitions})
-  end
-
-  defp init_partitions({:via, _, _}, partitions) do
-    child_spec = {Registry, keys: :unique, name: @registry}
-
-    unless Process.whereis(@registry) do
-      Supervisor.start_child(:elixir_sup, child_spec)
-    end
-
-    Registry.register(@registry, self(), partitions)
-  end
-
-  @doc """
-  Returns the number of partitions for the partition supervisor.
-  """
-  @doc since: "1.14.0"
-  @spec partitions(name()) :: pos_integer()
-  def partitions(name) do
-    {_name, partitions} = name_partitions(name)
-    partitions
-  end
-
-  # For whereis_name, we want to lookup on GenServer.whereis/1
-  # just once, so we lookup the name and partitions together.
-  defp name_partitions(name) when is_atom(name) do
-    try do
-      {name, :ets.lookup_element(name, :partitions, 2)}
-    rescue
-      _ -> exit({:noproc, {__MODULE__, :partitions, [name]}})
-    end
-  end
-
-  defp name_partitions(name) when is_tuple(name) do
-    with pid when is_pid(pid) <- GenServer.whereis(name),
-         [name_partitions] <- Registry.lookup(@registry, pid) do
-      name_partitions
-    else
-      _ -> exit({:noproc, {__MODULE__, :partitions, [name]}})
-    end
-  end
-
-  @doc """
-  Returns a list with information about all children.
-
-  This function returns a list of tuples containing:
-
-    * `id` - the partition number
-
-    * `child` - the PID of the corresponding child process or the
-      atom `:restarting` if the process is about to be restarted
-
-    * `type` - `:worker` or `:supervisor` as defined in the child
-      specification
-
-    * `modules` - as defined in the child specification
-
-  """
-  @doc since: "1.14.0"
-  @spec which_children(name()) :: [
-          # Inlining [module()] | :dynamic here because :supervisor.modules() is not exported
-          {:undefined, pid | :restarting, :worker | :supervisor, [module()] | :dynamic}
-        ]
-  def which_children(name) when is_atom(name) or elem(name, 0) == :via do
-    Supervisor.which_children(name)
-  end
-
-  @doc """
-  Returns a map containing count values for the supervisor.
-
-  The map contains the following keys:
-
-    * `:specs` - the number of partitions (children processes)
-
-    * `:active` - the count of all actively running child processes managed by
-      this supervisor
-
-    * `:supervisors` - the count of all supervisors whether or not the child
-      process is still alive
-
-    * `:workers` - the count of all workers, whether or not the child process
-      is still alive
-
-  """
-  @doc since: "1.14.0"
-  @spec count_children(name()) :: %{
-          specs: non_neg_integer,
-          active: non_neg_integer,
-          supervisors: non_neg_integer,
-          workers: non_neg_integer
-        }
-  def count_children(supervisor) when is_atom(supervisor) do
-    Supervisor.count_children(supervisor)
-  end
-
-  @doc """
-  Synchronously stops the given partition supervisor with the given `reason`.
-
-  It returns `:ok` if the supervisor terminates with the given
-  reason. If it terminates with another reason, the call exits.
-
-  This function keeps OTP semantics regarding error reporting.
-  If the reason is any other than `:normal`, `:shutdown` or
-  `{:shutdown, _}`, an error report is logged.
-  """
-  @doc since: "1.14.0"
-  @spec stop(name(), reason :: term, timeout) :: :ok
-  def stop(supervisor, reason \\ :normal, timeout \\ :infinity) when is_atom(supervisor) do
-    Supervisor.stop(supervisor, reason, timeout)
-  end
-
-  ## Via callbacks
-
-  @doc false
-  def whereis_name({name, key}) when is_atom(name) or is_tuple(name) do
-    {name, partitions} = name_partitions(name)
-
-    partition =
-      if is_integer(key), do: rem(abs(key), partitions), else: :erlang.phash2(key, partitions)
-
-    whereis_name(name, partition)
-  end
-
-  defp whereis_name(name, partition) when is_atom(name) do
-    :ets.lookup_element(name, partition, 2)
-  end
-
-  defp whereis_name(name, partition) when is_pid(name) do
-    @registry
-    |> Registry.values({name, partition}, name)
-    |> List.first(:undefined)
-  end
-
-  @doc false
-  def send(name_key, msg) do
-    Kernel.send(whereis_name(name_key), msg)
-  end
-
-  @doc false
-  def register_name(_, _) do
-    raise "{:via, PartitionSupervisor, _} cannot be given on registration"
-  end
-
-  @doc false
-  def unregister_name(_, _) do
-    raise "{:via, PartitionSupervisor, _} cannot be given on unregistration"
-  end
-end

lib/elixir/lib/path.ex

@@ -3,25 +3,20 @@ defmodule Path do
   This module provides conveniences for manipulating or
   retrieving file system paths.
 
-  The functions in this module may receive chardata as
-  arguments and will always return a string encoded in UTF-8. Chardata
-  is a string or a list of characters and strings, see `t:IO.chardata/0`.
-  If a binary is given, in whatever encoding, its encoding will be kept.
+  The functions in this module may receive a chardata as
+  argument (i.e. a string or a list of characters / string)
+  and will always return a string (encoded in UTF-8).
 
   The majority of the functions in this module do not
   interact with the file system, except for a few functions
   that require it (like `wildcard/2` and `expand/1`).
   """
 
-  @typedoc """
-  A path.
-  """
   @type t :: IO.chardata()
 
   @doc """
-  Converts the given path to an absolute one.
-
-  Unlike `expand/1`, no attempt is made to resolve `..`, `.`, or `~`.
+  Converts the given path to an absolute one. Unlike
+  `expand/1`, no attempt is made to resolve `..`, `.` or `~`.
 
   ## Examples
 
@@ -152,8 +147,8 @@ defmodule Path do
   defp reverse_maybe_remove_dir_sep(name, _), do: :lists.reverse(name)
 
   @doc """
-  Converts the path to an absolute one, expanding
-  any `.` and `..` components and a leading `~`.
+  Converts the path to an absolute one and expands
+  any `.` and `..` characters and a leading `~`.
 
   ## Examples
 
@@ -371,9 +366,6 @@ defmodule Path do
       iex> Path.basename("foo/bar")
       "bar"
 
-      iex> Path.basename("lib/module/submodule.ex")
-      "submodule.ex"
-
       iex> Path.basename("/")
       ""
 
@@ -433,16 +425,6 @@ defmodule Path do
   @doc """
   Returns the extension of the last component of `path`.
 
-  The behaviour of this function changed in Erlang/OTP 24 for filenames
-  starting with a dot and without an extension. For example, for a file
-  named `.gitignore`, `extname/1` now returns an empty string, while it
-  would return `".gitignore"` in previous Erlang/OTP versions. This was
-  done to match the behaviour of `rootname/1`, which would return
-  `".gitignore"` as its name (and therefore it cannot also be an extension).
-
-  See `basename/1` and `rootname/1` for related functions to extract
-  information from paths.
-
   ## Examples
 
       iex> Path.extname("foo.erl")
@@ -500,8 +482,6 @@ defmodule Path do
   This function should be used to convert a list of paths to a path.
   Note that any trailing slash is removed when joining.
 
-  Raises an error if the given list of paths is empty.
-
   ## Examples
 
       iex> Path.join(["~", "foo"])
@@ -541,7 +521,6 @@ defmodule Path do
       iex> Path.join(["foo", "bar"], "fiz")
       "foobar/fiz"
 
-  Use `join/1` if you need to join a list of paths instead.
   """
   @spec join(t, t) :: binary
   def join(left, right) do
@@ -575,7 +554,7 @@ defmodule Path do
 
   If an empty string is given, returns an empty list.
 
-  On Windows, path is split on both `"\"` and `"/"` separators
+  On Windows, path is split on both "\" and "/" separators
   and the driver letter, if there is one, is always returned
   in lowercase.
 
@@ -592,6 +571,7 @@ defmodule Path do
 
   """
   @spec split(t) :: [binary]
+
   def split(path) do
     :filename.split(IO.chardata_to_string(path))
   end
@@ -667,7 +647,7 @@ defmodule Path do
 
   """
   @spec wildcard(t, keyword) :: [binary]
-  def wildcard(glob, opts \\ []) when is_list(opts) do
+  def wildcard(glob, opts \\ []) do
     mod = if Keyword.get(opts, :match_dot), do: :file, else: Path.Wildcard
 
     glob
@@ -730,74 +710,4 @@ defmodule Path do
   defp major_os_type do
     :os.type() |> elem(0)
   end
-
-  @doc """
-  Returns a relative path that is protected from directory-traversal attacks.
-
-  The given relative path is sanitized by eliminating `..` and `.` components.
-
-  This function checks that, after expanding those components, the path is still "safe".
-  Paths are considered unsafe if either of these is true:
-
-    * The path is not relative, such as `"/foo/bar"`.
-
-    * A `..` component would make it so that the path would travers up above
-      the root of `relative_to`.
-
-    * A symbolic link in the path points to something above the root of `relative_to`.
-
-  ## Examples
-
-      iex> Path.safe_relative_to("deps/my_dep/app.beam", "deps")
-      {:ok, "deps/my_dep/app.beam"}
-
-      iex> Path.safe_relative_to("deps/my_dep/./build/../app.beam", "deps")
-      {:ok, "deps/my_dep/app.beam"}
-
-      iex> Path.safe_relative_to("my_dep/../..", "deps")
-      :error
-
-      iex> Path.safe_relative_to("/usr/local", ".")
-      :error
-
-  """
-  @doc since: "1.14.0"
-  @spec safe_relative_to(t, t) :: {:ok, binary} | :error
-  def safe_relative_to(path, relative_to) do
-    path = IO.chardata_to_string(path)
-
-    case :filelib.safe_relative_path(path, relative_to) do
-      :unsafe -> :error
-      relative_path -> {:ok, IO.chardata_to_string(relative_path)}
-    end
-  end
-
-  @doc """
-  Returns a path relative to the current working directory that is
-  protected from directory-traversal attacks.
-
-  Same as `safe_relative_to/2` with the current working directory as
-  the second argument. If there is an issue retrieving the current working
-  directory, this function raises an error.
-
-  ## Examples
-
-      iex> Path.safe_relative("foo")
-      {:ok, "foo"}
-
-      iex> Path.safe_relative("foo/../bar")
-      {:ok, "bar"}
-
-      iex> Path.safe_relative("foo/../..")
-      :error
-
-      iex> Path.safe_relative("/usr/local")
-      :error
-
-  """
-  @doc since: "1.14.0"
-  @spec safe_relative(t) :: {:ok, binary} | :error
-  def safe_relative(path) do
-    safe_relative_to(path, File.cwd!())
-  end
 end

lib/elixir/lib/port.ex

@@ -24,7 +24,7 @@ defmodule Port do
   receives data from multiple inputs and concatenates them in the output.
 
   After the port was created, we sent it two commands in the form of
-  messages using `send/2`. The first command has the binary payload
+  messages using `Kernel.send/2`. The first command has the binary payload
   of "hello" and the second has "world".
 
   After sending those two messages, we invoked the IEx helper `flush()`,
@@ -222,7 +222,7 @@ defmodule Port do
   @doc """
   Sends `data` to the port driver `port`.
 
-  For more information, see `:erlang.port_command/3`.
+  For more information, see `:erlang.port_command/2`.
 
   Inlined by the compiler.
   """
@@ -250,7 +250,7 @@ defmodule Port do
   """
   @spec info(port) :: keyword | nil
   def info(port) do
-    nilify(:erlang.port_info(port))
+    nillify(:erlang.port_info(port))
   end
 
   @doc """
@@ -270,7 +270,7 @@ defmodule Port do
   end
 
   def info(port, item) do
-    nilify(:erlang.port_info(port, item))
+    nillify(:erlang.port_info(port, item))
   end
 
   @doc """
@@ -323,7 +323,7 @@ defmodule Port do
     :erlang.ports()
   end
 
-  @compile {:inline, nilify: 1}
-  defp nilify(:undefined), do: nil
-  defp nilify(other), do: other
+  @compile {:inline, nillify: 1}
+  defp nillify(:undefined), do: nil
+  defp nillify(other), do: other
 end

lib/elixir/lib/process.ex

@@ -116,7 +116,7 @@ defmodule Process do
   """
   @spec put(term, term) :: term | nil
   def put(key, value) do
-    nilify(:erlang.put(key, value))
+    nillify(:erlang.put(key, value))
   end
 
   @doc """
@@ -136,7 +136,7 @@ defmodule Process do
   """
   @spec delete(term) :: term | nil
   def delete(key) do
-    nilify(:erlang.erase(key))
+    nillify(:erlang.erase(key))
   end
 
   @doc """
@@ -383,19 +383,12 @@ defmodule Process do
   @type spawn_opt ::
           :link
           | :monitor
-          | {:monitor, monitor_option()}
           | {:priority, :low | :normal | :high}
           | {:fullsweep_after, non_neg_integer}
           | {:min_heap_size, non_neg_integer}
           | {:min_bin_vheap_size, non_neg_integer}
-          | {:max_heap_size, heap_size}
-          | {:message_queue_data, :off_heap | :on_heap}
   @type spawn_opts :: [spawn_opt]
 
-  # TODO: Use :erlang.monitor_option() on Erlang/OTP 24+
-  @typep monitor_option ::
-           [alias: :explicit_unalias | :demonitor | :reply_demonitor, tag: term()]
-
   @doc """
   Spawns the given function according to the given options.
 
@@ -650,7 +643,7 @@ defmodule Process do
   """
   @spec whereis(atom) :: pid | port | nil
   def whereis(name) do
-    nilify(:erlang.whereis(name))
+    nillify(:erlang.whereis(name))
   end
 
   @doc """
@@ -749,7 +742,7 @@ defmodule Process do
   """
   @spec info(pid) :: keyword | nil
   def info(pid) do
-    nilify(:erlang.process_info(pid))
+    nillify(:erlang.process_info(pid))
   end
 
   @doc """
@@ -770,7 +763,7 @@ defmodule Process do
   end
 
   def info(pid, spec) when is_atom(spec) or is_list(spec) do
-    nilify(:erlang.process_info(pid, spec))
+    nillify(:erlang.process_info(pid, spec))
   end
 
   @doc """
@@ -788,7 +781,7 @@ defmodule Process do
   @spec hibernate(module, atom, list) :: no_return
   defdelegate hibernate(mod, fun_name, args), to: :erlang
 
-  @compile {:inline, nilify: 1}
-  defp nilify(:undefined), do: nil
-  defp nilify(other), do: other
+  @compile {:inline, nillify: 1}
+  defp nillify(:undefined), do: nil
+  defp nillify(other), do: other
 end