Release v1.17.0-rc.0

Branch out v1.17
2024-05-24 12:38:20 +02:00 · 2024-05-24 12:37:32 +02:00
693 changed files with 25718 additions and 89467 deletions
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 [
  inputs: [
    "lib/*/{lib,scripts,unicode,test}/**/*.{ex,exs}",
@@ -21,5 +17,6 @@

    # Float tests
    float_assert: 1
-  ]
+  ],
+  normalize_bitstring_modifiers: false
 ]
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 lib/elixir/test/elixir/fixtures/*.txt text eol=lf
 *.ex diff=elixir
 *.exs diff=elixir
@@ -1,6 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-
 ---
 blank_issues_enabled: true

@@ -1,9 +1,7 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-
 ---
 name: Report an issue
-description: Tell us about something that is not working the way we (probably) intend
+description:
+  Tell us about something that is not working the way we (probably) intend
 body:
  - type: markdown
    attributes:
@@ -12,17 +10,11 @@ body:


        Please, do not use this form for guidance, questions or support.
-        Try instead in [Elixir Forum](https://elixirforum.com) or any of
-        our online communities (Slack, Discord, etc).
-
-  - type: checkboxes
-    id: existing-issue
-    attributes:
-      label: Existing issue
-      description: Please search [existing issues](https://github.com/elixir-lang/elixir/issues) before continuing.
-      options:
-        - label: I have searched existing issues and could not find a duplicate.
-          required: true
+        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
@@ -1,11 +1,6 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-
 version: 2
 updates:
  - package-ecosystem: "github-actions"
    directory: "/"
    schedule:
      interval: "weekly"
-    cooldown:
-      default-days: 7
@@ -1,4 +0,0 @@
-* Describe here the reasons behind the pull request.
-* Make sure you have read the CONTRIBUTING.md file.
-* Make sure any relevant documentation and tests have been added/updated.
-* Do not submit Draft pull requests unless previously asked/agreed.
@@ -0,0 +1,134 @@
+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: 25
+            otp_version: "25.3"
+            upload_generic_version: upload_generic_version
+          - otp: 26
+            otp_version: "26.0"
+          - otp: 27
+            otp_version: "27.0"
+            build_docs: build_docs
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v4
+        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
+      - name: Upload Precompiled to S3
+        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: ${{ secrets.HEX_FASTLY_KEY }}
+        run: |
+          source utils.sh
+          aws s3 cp elixir-otp-${{ matrix.otp }}.zip "s3://${{ env.AWS_S3_BUCKET }}/builds/elixir/${{github.ref_name}}-otp-${{matrix.otp}}.zip" --cache-control "public,max-age=3600" --metadata "{\"surrogate-key\":\"builds builds/elixir builds/elixir/${{github.ref_name}}-otp-${{matrix.otp}}\",\"surrogate-control\":\"public,max-age=604800\"}"
+          purge builds/elixir/${{github.ref_name}}-otp-${{matrix.otp}}
+          if [ "${{matrix.upload_generic_version}}" == "upload_generic_version" ]; then
+            aws s3 cp elixir-otp-${{ matrix.otp }}.zip "s3://${{ env.AWS_S3_BUCKET }}/builds/elixir/${{github.ref_name}}.zip" --cache-control "public,max-age=3600" --metadata "{\"surrogate-key\":\"builds builds/elixir builds/elixir/${{github.ref_name}}\",\"surrogate-control\":\"public,max-age=604800\"}"
+            purge builds/elixir/${{github.ref_name}}
+          fi
+      - name: Update builds txt
+        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: ${{ secrets.HEX_FASTLY_KEY }}
+        run: |
+          source utils.sh
+          date=$(date -u '+%Y-%m-%dT%H:%M:%SZ')
+          build_sha256=$(sha256sum elixir-otp-${{ matrix.otp }}.zip | cut -d ' ' -f 1)
+          ref_name=${{ github.ref_name }}
+          aws s3 cp s3://${{ env.AWS_S3_BUCKET }}/builds/elixir/builds.txt builds.txt || true
+          touch builds.txt
+          sed -i "/^${ref_name}-otp-${{ matrix.otp }} /d" builds.txt
+          echo -e "${ref_name}-otp-${{ matrix.otp }} ${{ github.sha }} ${date} ${build_sha256} \n$(cat builds.txt)" > builds.txt
+          if [ "${{matrix.upload_generic_version}}" == "upload_generic_version" ]; then
+            sed -i "/^${ref_name} /d" builds.txt
+            echo -e "${ref_name} ${{ github.sha }} ${date} ${build_sha256} \n$(cat builds.txt)" > builds.txt
+          fi
+          sort -u -k1,1 -o builds.txt builds.txt
+          aws s3 cp builds.txt s3://${{ env.AWS_S3_BUCKET }}/builds/elixir/builds.txt --cache-control "public,max-age=3600" --metadata '{"surrogate-key":"builds builds/elixir builds/elixir/txt","surrogate-control":"public,max-age=604800"}'
+          purge builds/elixir/txt
@@ -0,0 +1,34 @@
+name: CI for Markdown content
+
+on:
+  push:
+    branches:
+      - 'main'
+    paths:
+      - 'lib/**/*.md'
+  pull_request:
+    paths:
+      - 'lib/**/*.md'
+  workflow_dispatch:
+
+jobs:
+  lint:
+    name: Lint Markdown content
+
+    strategy:
+      fail-fast: false
+
+    runs-on: ubuntu-20.04
+
+    steps:
+      - name: Check out the repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 10
+
+      - name: Run markdownlint
+        uses: DavidAnson/markdownlint-cli2-action@v16.0.0
+        with:
+          globs: |
+            lib/elixir/pages/**/*.md
+            README.md
@@ -1,17 +1,17 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 name: CI

 on:
  push:
+    paths-ignore:
+      - "lib/**/*.md"
  pull_request:
-  workflow_dispatch:
+    paths-ignore:
+      - "lib/**/*.md"

 env:
  ELIXIR_ASSERT_TIMEOUT: 2000
  ELIXIRC_OPTS: "--warnings-as-errors"
+  ERLC_OPTS: "warnings_as_errors"
  LANG: C.UTF-8

 permissions:
@@ -19,133 +19,102 @@ permissions:

 jobs:
  test_linux:
-    name: Ubuntu 24.04, OTP ${{ matrix.otp_version }}${{ matrix.deterministic && ' (deterministic)' || '' }}${{ matrix.coverage && ' (coverage)' || '' }}
-    runs-on: ubuntu-24.04
-
+    name: Ubuntu 20.04, Erlang/OTP ${{ matrix.otp_version }}
    strategy:
      fail-fast: false
      matrix:
        include:
-          - otp_version: "29.0"
-            deterministic: true
-          - otp_version: "28.4"
-            docs: true
-            coverage: true
-          - otp_version: "28.1"
-          - otp_version: "27.3"
          - otp_version: "27.0"
+            otp_latest: true
+          - otp_version: "26.0"
+          - otp_version: "25.3"
+          - otp_version: "25.0"
          - otp_version: master
            development: true
          - otp_version: maint
            development: true
-
-    env:
-      ERLC_OPTS: "warnings_as_errors"
+    runs-on: ubuntu-20.04
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@v4
        with:
-          persist-credentials: false
-
-      - uses: erlef/setup-beam@54075bcc5e249e4758d363f27d099f55d843f124 # v1.24.1
+          fetch-depth: 50
+      - uses: erlef/setup-beam@v1
        with:
          otp-version: ${{ matrix.otp_version }}
-
-      - name: Set ERL_COMPILER_OPTIONS
-        if: ${{ matrix.deterministic }}
-        run: echo "ERL_COMPILER_OPTIONS=deterministic" >> $GITHUB_ENV
-
      - name: Compile Elixir
        run: |
          make compile
          echo "$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: Erlang test suite
        run: make test_erlang
-        continue-on-error: ${{ matrix.development == true }}
-
+        continue-on-error: ${{ matrix.development }}
      - name: Elixir test suite
        run: make test_elixir
-        continue-on-error: ${{ matrix.development == true }}
-        env:
-          COVER: "${{ matrix.coverage }}"
-
+        continue-on-error: ${{ matrix.development }}
      - name: Build docs (ExDoc main)
-        if: ${{ matrix.docs }}
+        if: ${{ matrix.otp_latest }}
        run: |
          cd ..
          git clone https://github.com/elixir-lang/ex_doc.git --depth 1
          cd ex_doc
          ../elixir/bin/mix do local.rebar --force + local.hex --force + deps.get + compile
          cd ../elixir/
-          git fetch --tags
-          DOCS_OPTIONS="--warnings-as-errors" make docs
-
-      - name: "Calculate Coverage"
-        if: ${{ matrix.coverage }}
-        run: make cover | tee "$GITHUB_STEP_SUMMARY"
-
-      - name: "Upload Coverage Artifact"
-        if: ${{ matrix.coverage }}
-        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
-        with:
-          name: TestCoverage
-          path: cover/*
-
+          make docs
      - name: Check reproducible builds
-        if: ${{ matrix.deterministic }}
-        run: taskset 1 make check_reproducible
-
-      - name: Check git is not required
-        if: ${{ matrix.deterministic }}
        run: |
          rm -rf .git
-          cd lib/elixir
-          elixirc --ignore-module-conflict -o ebin "lib/**/*.ex"
+          # Recompile System without .git
+          cd lib/elixir && ../../bin/elixirc -o ebin lib/system.ex && cd -
+          taskset 1 make check_reproducible
+        if: ${{ matrix.otp_latest }}

  test_windows:
-    name: Windows Server 2022, OTP ${{ matrix.otp_version }}
-    runs-on: windows-2022
-
+    name: Windows Server 2019, Erlang/OTP ${{ matrix.otp_version }}
    strategy:
      matrix:
-        otp_version:
-          - "29.0"
-          - "28.1"
-          - "27.3"
-
+        otp_version: ["25.3", "26.0"]
+    runs-on: windows-2019
    steps:
      - name: Configure Git
        run: git config --global core.autocrlf input
-
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@v4
        with:
-          persist-credentials: false
-
-      - uses: erlef/setup-beam@54075bcc5e249e4758d363f27d099f55d843f124 # v1.24.1
+          fetch-depth: 50
+      - uses: erlef/setup-beam@v1
        with:
          otp-version: ${{ matrix.otp_version }}
-
      - name: Compile Elixir
        run: |
          Remove-Item -Recurse -Force '.git'
          make compile
-
      - name: Build info
        run: bin/elixir --version
-
      - name: Check format
        run: make test_formatted && echo "All Elixir source code files are properly formatted."
-
      - name: Erlang test suite
-        run: make test_erlang
-
+        run: make --keep-going test_erlang
      - name: Elixir test suite
        run: |
          Remove-Item 'c:/Windows/System32/drivers/etc/hosts'
-          make test_elixir
+          make --keep-going test_elixir
+
+  check_posix_compliant:
+    name: Check POSIX-compliant
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 50
+      - name: Install Shellcheck
+        run: |
+          sudo apt update
+          sudo apt install -y shellcheck
+      - name: Check POSIX-compliant
+        run: |
+          shellcheck -e SC2039,2086 bin/elixir && echo "bin/elixir is POSIX compliant"
+          shellcheck bin/elixirc && echo "bin/elixirc is POSIX compliant"
+          shellcheck bin/iex && echo "bin/iex is POSIX compliant"
@@ -1,55 +0,0 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2026 The Elixir Team
-
-name: "CodeQL Advanced"
-
-on:
-  push:
-    branches: ["main"]
-  pull_request:
-    branches: ["main"]
-  schedule:
-    - cron: "29 8 * * 1"
-
-permissions:
-  contents: read
-
-jobs:
-  analyze:
-    name: Analyze (${{ matrix.language }})
-    runs-on: "ubuntu-latest"
-    permissions:
-      security-events: write
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - language: actions
-            build-mode: none
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-        with:
-          persist-credentials: false
-      - name: Initialize CodeQL
-        uses: github/codeql-action/init@8aad20d150bbac5944a9f9d289da16a4b0d87c1e # v4.36.2
-        with:
-          languages: ${{ matrix.language }}
-          build-mode: ${{ matrix.build-mode }}
-      - name: Perform CodeQL Analysis
-        uses: github/codeql-action/analyze@cdf488f595d80d6e07e03d4674febd5ab45fa938 # v4.37.9
-        with:
-          category: "/language:${{matrix.language}}"
-
-  zizmor:
-    name: Zizmor
-    runs-on: ubuntu-latest
-    permissions:
-      security-events: write
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-        with:
-          persist-credentials: false
-      - name: Run zizmor
-        uses: zizmorcore/zizmor-action@3dc1ecc9bcb9e94e9b2c709687979e1298497054 # v0.6.2
@@ -1,41 +0,0 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-
-name: License Compliance
-
-on:
-  push:
-  pull_request:
-  workflow_dispatch:
-
-permissions:
-  contents: read
-
-env:
-  LANG: C.UTF-8
-
-jobs:
-  license_compliance:
-    name: Check License Compliance
-    runs-on: ubuntu-24.04
-
-    steps:
-      - name: Use HTTPS instead of SSH for Git cloning
-        id: git-config
-        shell: bash
-        run: git config --global url.https://github.com/.insteadOf ssh://git@github.com/
-
-      - name: Checkout project
-        id: checkout
-        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-        with:
-          persist-credentials: false
-
-      - name: Run OSS Review Toolkit
-        id: ort
-        uses: ./.github/workflows/ort
-        with:
-          upload-reports: true
-          fail-on-violation: true
-          report-formats: "WebApp"
-          version: "${{ github.sha }}"
@@ -1,41 +0,0 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-
-name: Markdown Content
-
-on:
-  push:
-    branches:
-      - "main"
-
-    paths: &paths-filter
-      - "**/*.md"
-      - .github/workflows/markdown.yml
-      - .markdownlint-cli2.jsonc
-
-  pull_request:
-    paths: *paths-filter
-
-  workflow_dispatch:
-
-permissions:
-  contents: read
-
-env:
-  LANG: C.UTF-8
-
-jobs:
-  lint:
-    name: Lint Markdown content
-    runs-on: ubuntu-latest
-
-    strategy:
-      fail-fast: false
-
-    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-        with:
-          persist-credentials: false
-
-      - name: Run markdownlint-cli2
-        uses: DavidAnson/markdownlint-cli2-action@21c1be1b93ad9ed58fa840aacc3f279cde2a72ff # v24.2.0
@@ -1,8 +1,4 @@
 # #!/usr/bin/env elixir
-
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-
 [tag] = System.argv()

 Mix.install([
@@ -74,6 +70,6 @@ unless System.get_env("DRYRUN") do
    "api-username" => "Elixir"
  }

-  resp = Req.post!("https://forum.elixirforum.com/posts.json", {:json, post}, headers: headers)
+  resp = Req.post!("https://elixirforum.com/posts.json", {:json, post}, headers: headers)
  IO.puts("#{resp.status} Elixir Forum\n#{inspect(resp.body)}")
 end
@@ -0,0 +1,28 @@
+name: Notify
+
+on:
+  release:
+    types:
+      - published
+
+permissions:
+  contents: read
+
+jobs:
+  notify:
+    runs-on: ubuntu-20.04
+    name: Notify
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 50
+      - uses: erlef/setup-beam@v1
+        with:
+          otp-version: '25.0'
+          elixir-version: '1.14.0'
+      - 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 ${{ github.ref_name }}
@@ -1,112 +0,0 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-
-name: "Run OSS Review Toolkit"
-description: "Runs OSS Review Toolkit & generates SBoMs"
-inputs:
-  report-formats:
-    description: "ORT Report Formats"
-    required: true
-  fail-on-violation:
-    description: "Whether to fail on violation."
-    required: false
-    default: false
-  upload-reports:
-    description: "Whether to upload all reports"
-    required: false
-    default: false
-  version:
-    description: "Elixir Version (Tag / SHA)"
-    required: true
-
-outputs:
-  results-path:
-    description: "See oss-review-toolkit/ort-ci-github-action action"
-    value: "${{ steps.ort.outputs.results-path }}"
-  results-sbom-cyclonedx-xml-path:
-    description: "See oss-review-toolkit/ort-ci-github-action action"
-    value: "${{ steps.ort.outputs.results-sbom-cyclonedx-xml-path }}"
-  results-sbom-cyclonedx-json-path:
-    description: "See oss-review-toolkit/ort-ci-github-action action"
-    value: "${{ steps.ort.outputs.results-sbom-cyclonedx-json-path }}"
-  results-sbom-spdx-yml-path:
-    description: "See oss-review-toolkit/ort-ci-github-action action"
-    value: "${{ steps.ort.outputs.results-sbom-spdx-yml-path }}"
-  results-sbom-spdx-json-path:
-    description: "See oss-review-toolkit/ort-ci-github-action action"
-    value: "${{ steps.ort.outputs.results-sbom-spdx-json-path }}"
-
-runs:
-  using: "composite"
-  steps:
-    - name: Fetch Default ORT Config
-      id: fetch-default-ort-config
-      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-      with:
-        repository: oss-review-toolkit/ort-config
-        ref: "main"
-        path: ".ort-config"
-        persist-credentials: false
-
-    - name: Setup ORT Config
-      id: setup-ort-config
-      shell: bash
-      run: |
-        mkdir -p "/$HOME/.ort/"
-
-        # Move Fetched Default Config into Place
-        mv .ort-config "$HOME/.ort/config"
-        
-        # Append Global ORT Config
-        cat .ort/config/config.yml >> "$HOME/.ort/config/config.yml"
-        
-        # Override Default Evaluator Rules
-        cp .ort/config/evaluator.rules.kts "$HOME/.ort/config/evaluator.rules.kts"
-
-        # Add Package Configurations
-        mkdir -p "$HOME/.ort/config/package-configurations/SpdxDocumentFile/The Elixir Team"
-        for FILE in .ort/package-configurations/*.yml; do
-          COMPONENT="$(basename "$FILE")"
-          cp "$FILE" "$HOME/.ort/config/package-configurations/SpdxDocumentFile/The Elixir Team/$COMPONENT"
-          sed -i -E \
-            "s/(\"SpdxDocumentFile:The Elixir Team:.+:)\"/\1${ELIXIR_VERSION}\"/" \
-            "$HOME/.ort/config/package-configurations/SpdxDocumentFile/The Elixir Team/$COMPONENT"
-        done
-
-        # Set Version in SPDX & Config
-        sed -i "s/# elixir-version-insert/versionInfo: '${ELIXIR_VERSION}'/" project.spdx.yml
-        sed -i -E "s/(\"SpdxDocumentFile:The Elixir Team:.+:)\"/\1${ELIXIR_VERSION}\"/" .ort.yml
-        sed -i "s|https://github.com/elixir-lang/elixir.git|${ELIXIR_REPO}@${ELIXIR_VERSION}|" project.spdx.yml
-      env:
-        ELIXIR_VERSION: "${{ inputs.version }}"
-        ELIXIR_REPO: "${{ github.server_url }}/${{ github.repository }}.git"
-
-    - name: "Cache ScanCode"
-      uses: actions/cache@d4323d4df104b026a6aa633fdb11d772146be0bf # v4.2.2
-      with:
-        path: "~/.cache/scancode-tk"
-        key: ${{ runner.os }}-scancode
-
-    - name: Run OSS Review Toolkit
-      id: ort
-      uses: oss-review-toolkit/ort-ci-github-action@086d928d24ef1653dc0777296b312fda5faaaf52 # v1.2.0
-      with:
-        image: ghcr.io/oss-review-toolkit/ort:92.2.0
-        run: >-
-          labels,
-          cache-dependencies,
-          cache-scan-results,
-          analyzer,
-          scanner,
-          advisor,
-          evaluator,
-          reporter,
-          ${{ inputs.upload-reports == 'true' && 'upload-results' || '' }}
-        fail-on: "${{ inputs.fail-on-violation == 'true' && 'violations,issues' || '' }}"
-        report-formats: "${{ inputs.report-formats }}"
-        ort-cli-report-args: >-
-          -O CycloneDX=output.file.formats=json,xml
-          -O SpdxDocument=outputFileFormats=JSON,YAML
-        ort-cli-scan-args: >-
-          --scanners Provenant
-        sw-version: "${{ inputs.version }}"
@@ -1,53 +0,0 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
-name: POSIX Compliance
-
-on:
-  push:
-    paths: &paths-filter
-      - .github/workflows/posix_compliance.yml
-      - bin/elixir
-      - bin/elixirc
-      - bin/iex
-
-  pull_request:
-    paths: *paths-filter
-
-  workflow_dispatch:
-
-permissions:
-  contents: read
-
-env:
-  LANG: C.UTF-8
-
-jobs:
-  check_posix_compliance:
-    name: Check POSIX compliance
-    runs-on: ubuntu-latest
-
-    strategy:
-      fail-fast: false
-
-    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-        with:
-          persist-credentials: false
-
-      - name: Install ShellCheck
-        run: |
-          sudo apt update
-          sudo apt install -y shellcheck
-
-      - name: Run ShellCheck on bin/ dir
-        run: |
-          shellcheck -e SC2039,2086 bin/elixir && \
-            echo "bin/elixir is POSIX compliant"
-
-          shellcheck bin/elixirc && \
-            echo "bin/elixirc is POSIX compliant"
-
-          shellcheck bin/iex && \
-            echo "bin/iex is POSIX compliant"
@@ -1,446 +1,69 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-
-name: Releases
+name: Release

 on:
  push:
-    branches:
-      - main
-      - v*.*
-
    tags:
      - v*

-  workflow_dispatch:
-
 env:
  ELIXIR_OPTS: "--warnings-as-errors"
+  ERLC_OPTS: "warnings_as_errors"
  LANG: C.UTF-8

 permissions:
-  contents: read
+  contents: write

 jobs:
  create_draft_release:
-    name: Create draft release
-    runs-on: ubuntu-24.04
-
-    permissions:
-      contents: write
-
+    runs-on: ubuntu-22.04
    env:
      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-
    steps:
      - name: Create draft release
-        if: github.ref_type != 'branch'
        run: |
          gh release create \
-            --repo "$GITHUB_REPOSITORY" \
-            --title "$GITHUB_REF_NAME" \
+            --repo ${{ github.repository }} \
+            --title ${{ github.ref_name }} \
            --notes '' \
            --draft \
-            "$GITHUB_REF_NAME"
-
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-        # zizmor: ignore[artipacked]
-        if: github.ref_type == 'branch'
-
-      - name: Update ${{ github.ref_name }}-latest
-        if: github.ref_type == 'branch'
-        run: |
-          ref_name="${GITHUB_REF_NAME}-latest"
-
-          if ! gh release view "$ref_name"; then
-            gh release create \
-              --latest=false \
-              --title "$ref_name" \
-              --notes "Automated release for latest ${GITHUB_REF_NAME}." \
-              "$ref_name"
-          fi
-
-          git tag "$ref_name" --force
-          git push origin "$ref_name" --force
-
-  build:
-    name: Ubuntu 24.04, OTP ${{ matrix.otp_version }}${{ matrix.build_docs && ' (build docs)' || '' }}
-    runs-on: ubuntu-24.04
-
+            ${{ github.ref_name }}
+  release_pre_built:
+    needs: create_draft_release
    strategy:
      fail-fast: true
      matrix:
        include:
+          - otp: 25
+            otp_version: "25.3"
+          - otp: 26
+            otp_version: "26.0"
          - otp: 27
            otp_version: "27.0"
-
-          - otp: 28
-            otp_version: "28.0"
            build_docs: build_docs
-
-          - otp: 29
-            otp_version: "29.0"
-
+    runs-on: ubuntu-22.04
    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/checkout@v4
        with:
-          persist-credentials: false
-
-      - name: "Build Release"
-        uses: ./.github/workflows/release_pre_built
+          fetch-depth: 50
+      - uses: ./.github/workflows/release_pre_built
        with:
          otp_version: ${{ matrix.otp_version }}
          otp: ${{ matrix.otp }}
          build_docs: ${{ matrix.build_docs }}
-
-      - name: Create Docs Hashes
-        if: matrix.build_docs
-        run: |
-          shasum -a 1   Docs.zip > Docs.zip.sha1sum
-          shasum -a 256 Docs.zip > Docs.zip.sha256sum
-
-      - name: "Upload Linux release artifacts"
-        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
-        with:
-          name: build-linux-elixir-otp-${{ matrix.otp }}
-          path: elixir-otp-${{ matrix.otp }}.zip
-
-      - name: "Upload Windows release artifacts"
-        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
-        with:
-          name: build-windows-elixir-otp-${{ matrix.otp }}
-          path: elixir-otp-${{ matrix.otp }}.exe
-
-      - name: "Upload doc artifacts"
-        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
-        if: matrix.build_docs
-        with:
-          name: Docs
-          path: Docs.zip*
-
-  sign:
-    name: Sign files, ${{ matrix.flavor == 'windows' && 'Windows' || matrix.flavor == 'linux' && 'Linux' || matrix.flavor }}, OTP ${{ matrix.otp }}
-    needs: [build]
-    environment: release
-    strategy:
-      fail-fast: true
-      matrix:
-        otp: [27, 28, 29]
-        flavor: [windows, linux]
-
-    env:
-      RELEASE_FILE: elixir-otp-${{ matrix.otp }}.${{ matrix.flavor == 'linux' && 'zip' || 'exe' }}
-
-    runs-on: ${{ matrix.flavor == 'linux' && 'ubuntu-24.04' || 'windows-2022' }}
-
-    permissions:
-      contents: write
-      id-token: write
-
-    steps:
-      - name: "Download build"
-        uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
-        with:
-          name: build-${{ matrix.flavor }}-elixir-otp-${{ matrix.otp }}
-
-      - name: Log in to Azure
-        if: ${{ matrix.flavor == 'windows' && vars.AZURE_TRUSTED_SIGNING_ACCOUNT_NAME }}
-        uses: azure/login@f5d393ae46f8fde4be8b75f32e3fc50e654ad0ca # v3.0.1
-        with:
-          client-id: ${{ secrets.AZURE_CLIENT_ID }}
-          tenant-id: ${{ secrets.AZURE_TENANT_ID }}
-          subscription-id: ${{ secrets.AZURE_SUBSCRIPTION_ID }}
-
-      - name: "Sign files with Trusted Signing"
-        uses: azure/trusted-signing-action@c7ab2a863ab5f9a846ddb8265964877ef296ee82 # v2.0.0
-        if: ${{ matrix.flavor == 'windows' && vars.AZURE_TRUSTED_SIGNING_ACCOUNT_NAME }}
-        with:
-          endpoint: https://eus.codesigning.azure.net/
-          trusted-signing-account-name: ${{ vars.AZURE_TRUSTED_SIGNING_ACCOUNT_NAME }}
-          certificate-profile-name: ${{ vars.AZURE_CERTIFICATE_PROFILE_NAME }}
-          files-folder: ${{ github.workspace }}
-          files-folder-filter: exe
-          file-digest: SHA256
-          timestamp-rfc3161: http://timestamp.acs.microsoft.com
-          timestamp-digest: SHA256
-
-      - name: Create Release Hashes
-        if: matrix.flavor == 'windows'
-        shell: pwsh
-        run: |
-          $sha1 = Get-FileHash "$env:RELEASE_FILE" -Algorithm SHA1
-          $sha1.Hash.ToLower() + "  " + $env:RELEASE_FILE | Out-File "$env:RELEASE_FILE.sha1sum"
-
-          $sha256 = Get-FileHash "$env:RELEASE_FILE" -Algorithm SHA256
-          $sha256.Hash.ToLower() + "  " + $env:RELEASE_FILE | Out-File "$env:RELEASE_FILE.sha256sum"
-
-      - name: Create Release Hashes
-        if: matrix.flavor == 'linux'
-        shell: bash
-        run: |
-          shasum -a 1   "$RELEASE_FILE" > "${RELEASE_FILE}.sha1sum"
-          shasum -a 256 "$RELEASE_FILE" > "${RELEASE_FILE}.sha256sum"
-
-      - name: "Upload Linux release artifacts"
-        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
-        with:
-          name: sign-${{ matrix.flavor }}-elixir-otp-${{ matrix.otp }}
-          path: ${{ env.RELEASE_FILE }}*
-
-  sbom:
-    name: Generate SBoM
-    needs: [build, sign]
-    runs-on: ubuntu-24.04
-
-    permissions:
-      contents: write
-      id-token: write
-      attestations: write
-
-    steps:
-      - name: Use HTTPS instead of SSH for Git cloning
-        id: git-config
-        shell: bash
-        run: git config --global url.https://github.com/.insteadOf ssh://git@github.com/
-
-      - name: Checkout project
-        id: checkout
-        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-        with:
-          persist-credentials: false
-
-      - name: "Download Build Artifacts"
-        id: download-build-artifacts
-        uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
-        with:
-          pattern: "{sign-*-elixir-otp-*,Docs}"
-          merge-multiple: true
-          path: /tmp/build-artifacts/
-
-      - name: "Run OSS Review Toolkit"
-        id: ort
-        uses: ./.github/workflows/ort
-        with:
-          report-formats: "CycloneDx,SpdxDocument"
-          version: "${{ github.ref_type	== 'tag' && github.ref_name || github.sha }}"
-
-      - name: Attest Distribution Assets with SBoM
-        id: attest-sbom
-        uses: actions/attest-sbom@c604332985a26aa8cf1bdc465b92731239ec6b9e # v4.1.0
-        with:
-          subject-path: |
-            /tmp/build-artifacts/{elixir-otp-*.*,Docs.zip}
-            ${{ steps.ort.outputs.results-sbom-cyclonedx-xml-path }}
-            ${{ steps.ort.outputs.results-sbom-cyclonedx-json-path }}
-            ${{ steps.ort.outputs.results-sbom-spdx-yml-path }}
-            ${{ steps.ort.outputs.results-sbom-spdx-json-path }}
-          sbom-path: "${{ steps.ort.outputs.results-sbom-spdx-json-path }}"
-
-      - name: "Copy SBoM provenance"
-        id: sbom-provenance
-        shell: bash
-        run: |
-          mkdir attestations
-
-          for FILE in /tmp/build-artifacts/{elixir-otp-*.*,Docs.zip}; do
-            cp "$ATTESTATION" "attestations/$(basename "$FILE").sigstore"
-          done
-
-          cp "$ATTESTATION" "attestations/$(basename "$SBOM_CYCLONEDX_XML").sigstore"
-          cp "$ATTESTATION" "attestations/$(basename "$SBOM_CYCLONEDX_JSON").sigstore"
-          cp "$ATTESTATION" "attestations/$(basename "$SBOM_SPDX_YML").sigstore"
-          cp "$ATTESTATION" "attestations/$(basename "$SBOM_SPDX_JSON").sigstore"
-        env:
-          ATTESTATION: "${{ steps.attest-sbom.outputs.bundle-path }}"
-          SBOM_CYCLONEDX_XML: "${{ steps.ort.outputs.results-sbom-cyclonedx-xml-path }}"
-          SBOM_CYCLONEDX_JSON: "${{ steps.ort.outputs.results-sbom-cyclonedx-json-path }}"
-          SBOM_SPDX_YML: "${{ steps.ort.outputs.results-sbom-spdx-yml-path }}"
-          SBOM_SPDX_JSON: "${{ steps.ort.outputs.results-sbom-spdx-json-path }}"
-
-      - name: "Assemble Release SBoM Artifacts"
-        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
-        with:
-          name: "SBoM"
-          path: |
-            ${{ steps.ort.outputs.results-sbom-cyclonedx-xml-path }}
-            ${{ steps.ort.outputs.results-sbom-cyclonedx-json-path }}
-            ${{ steps.ort.outputs.results-sbom-spdx-yml-path }}
-            ${{ steps.ort.outputs.results-sbom-spdx-json-path }}
-
-      - name: "Assemble Distribution Attestations"
-        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
-        with:
-          name: "Attestations"
-          path: "attestations/*.sigstore"
-
-  upload-release:
-    name: Upload release
-    needs: [create_draft_release, build, sign, sbom]
-    runs-on: ubuntu-24.04
-
-    permissions:
-      contents: write
-
-    steps:
-      - uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
-        with:
-          pattern: "{sign-*-elixir-otp-*,Docs,SBoM,Attestations}"
-          merge-multiple: true
-
-      - name: Upload Pre-build
-        shell: bash
+      - name: Upload Pre-built
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
-          if [ "$GITHUB_REF_TYPE" == "branch" ]; then
-            tag="${GITHUB_REF_NAME}-latest"
-          else
-            tag="$GITHUB_REF_NAME"
-          fi
-
-          gh release upload \
-            --repo "$GITHUB_REPOSITORY" \
-            --clobber \
-            "$tag" \
-            elixir-otp-*.zip \
-            elixir-otp-*.zip.sha{1,256}sum \
-            elixir-otp-*.zip.sigstore \
-            elixir-otp-*.exe \
-            elixir-otp-*.exe.sha{1,256}sum \
-            elixir-otp-*.exe.sigstore \
-            Docs.zip \
-            Docs.zip.sha{1,256}sum \
-            Docs.zip.sigstore \
-            bom.*
-
-  upload-builds-hex-pm:
-    name: Upload builds to hex.pm
-    runs-on: ubuntu-24.04
-    needs: [build, sign]
-    concurrency: builds-hex-pm
-    environment: release
-
-    env:
-      AWS_ACCESS_KEY_ID: ${{ secrets.HEX_AWS_ACCESS_KEY_ID }}
-      AWS_SECRET_ACCESS_KEY: ${{ secrets.HEX_AWS_SECRET_ACCESS_KEY }}
-      AWS_REGION: ${{ vars.HEX_AWS_REGION }}
-      AWS_S3_BUCKET: ${{ vars.HEX_AWS_S3_BUCKET }}
-
-    steps:
-      - name: "Check if variables are set up"
-        if: "${{ ! vars.HEX_AWS_REGION }}"
-        run: |
-          echo "Required variables for uploading to hex.pm are not set up, skipping..."
-          exit 1
-
-      - uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
-        with:
-          pattern: "{sign-*-elixir-otp-*,Docs}"
-          merge-multiple: true
-
-      - name: Init purge keys file
-        run: |
-          touch purge_keys.txt
-
-      - name: Upload Precompiled to S3
-        run: |
-          oldest_otp=$(find . -type f -name 'elixir-otp-*.zip' | sed -r 's/^.*elixir-otp-([[:digit:]]+)\.zip$/\1/' | sort -n | head -n 1)
-
-          for zip in $(find . -type f -name 'elixir-otp-*.zip' | sed 's/^\.\///'); do
-            dest=${zip/elixir/${GITHUB_REF_NAME}}
-            surrogate_key=${dest/.zip$/}
-
-            aws s3 cp "${zip}" "s3://${AWS_S3_BUCKET}/builds/elixir/${dest}" \
-              --cache-control "public,max-age=3600" \
-              --metadata "{\"surrogate-key\":\"builds builds/elixir builds/elixir/${surrogate_key}\",\"surrogate-control\":\"public,max-age=604800\"}"
-            echo "builds/elixir/${surrogate_key}" >> purge_keys.txt
-
-            if [ "$zip" == "elixir-otp-${oldest_otp}.zip" ]; then
-              aws s3 cp "${zip}" "s3://${AWS_S3_BUCKET}/builds/elixir/${GITHUB_REF_NAME}.zip" \
-                --cache-control "public,max-age=3600" \
-                --metadata "{\"surrogate-key\":\"builds builds/elixir builds/elixir/${GITHUB_REF_NAME}\",\"surrogate-control\":\"public,max-age=604800\"}"
-              echo builds/elixir/${GITHUB_REF_NAME} >> purge_keys.txt
-            fi
-          done
-
-      - name: Upload Docs to S3
-        run: |
-          version=$(echo "$GITHUB_REF_NAME" | sed -e 's/^v//g')
-
-          unzip Docs.zip
-
-          for f in doc/*; do
-            if [ -d "$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 "${tarball}" "s3://${AWS_S3_BUCKET}/docs/${tarball}" \
-                --cache-control "public,max-age=3600" \
-                --metadata "{\"surrogate-key\":\"${surrogate_key}\",\"surrogate-control\":\"public,max-age=604800\"}"
-              echo "${surrogate_key}" >> ../purge_keys.txt
-            fi
-          done
-
-      - name: Update builds txt
-        run: |
-          date="$(date -u '+%Y-%m-%dT%H:%M:%SZ')"
-          ref_name="$GITHUB_REF_NAME"
-
-          oldest_otp=$(find . -name 'elixir-otp-*.zip.sha256sum' | sed -r 's/^.*elixir-otp-([[:digit:]]+)\.zip\.sha256sum$/\1/' | sort -n | head -n 1)
-
-          aws s3 cp "s3://${AWS_S3_BUCKET}/builds/elixir/builds.txt" builds.txt || true
-          touch builds.txt
-
-          for sha256_file in $(find . -name 'elixir-otp-*.zip.sha256sum' | sed 's/^\.\///'); do
-            otp_version=$(echo "${sha256_file}" | sed -r 's/^elixir-otp-([[:digit:]]+)\.zip\.sha256sum/otp-\1/')
-            build_sha256=$(cut -d ' ' -f 1 "${sha256_file}")
-
-            sed -i "/^${ref_name}-${otp_version} /d" builds.txt
-            echo -e "${ref_name}-${otp_version} ${{ github.sha }} ${date} ${build_sha256} \n$(cat builds.txt)" > builds.txt
-
-            if [ "${otp_version}" == "otp-${oldest_otp}" ]; then
-              sed -i "/^${ref_name} /d" builds.txt
-              echo -e "${ref_name} ${{ github.sha }} ${date} ${build_sha256} \n$(cat builds.txt)" > builds.txt
-            fi
-          done
-
-          sort -u -k1,1 -o builds.txt builds.txt
-          aws s3 cp builds.txt "s3://${AWS_S3_BUCKET}/builds/elixir/builds.txt" \
-            --cache-control "public,max-age=3600" \
-            --metadata '{"surrogate-key":"builds builds/elixir builds/elixir/txt","surrogate-control":"public,max-age=604800"}'
-
-          echo 'builds/elixir/txt' >> purge_keys.txt
-
-      - name: Flush cache
-        if: github.repository == 'elixir-lang/elixir'
-        run: |
-          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
-          }
-
-          for key in $(cat purge_keys.txt); do
-            purge "${key}"
-          done
-
+          gh release upload --clobber "${{ github.ref_name }}" \
+            elixir-otp-${{ matrix.otp }}.zip \
+            elixir-otp-${{ matrix.otp }}.zip.sha{1,256}sum \
+            elixir-otp-${{ matrix.otp }}.exe \
+            elixir-otp-${{ matrix.otp }}.exe.sha{1,256}sum
+      - name: Upload Docs to GitHub
+        if: ${{ matrix.build_docs }}
        env:
-          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 }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          gh release upload --clobber "${{ github.ref_name }}" \
+            Docs.zip \
+            Docs.zip.sha{1,256}sum
@@ -1,34 +0,0 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-
-name: Release Notifications
-
-on:
-  release:
-    types:
-      - published
-
-permissions:
-  contents: read
-
-jobs:
-  notify:
-    runs-on: ubuntu-latest
-    name: Notify
-
-    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-        with:
-          persist-credentials: false
-
-      - uses: erlef/setup-beam@54075bcc5e249e4758d363f27d099f55d843f124 # v1.24.1
-        with:
-          otp-version: "27.3"
-          elixir-version: "1.18.3"
-
-      - 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"
@@ -1,70 +1,57 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-
-name: Release Pre-build
-description: "Builds Elixir release, ExDoc and generates docs"
-
+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: "Whether docs have to be built"
-
+    description: "If docs have to be built or not"
 runs:
  using: "composite"
-
  steps:
-    - uses: erlef/setup-beam@5304e04ea2b355f03681464e683d92e3b2f18451 # v1.18.2
+    - uses: erlef/setup-beam@v1
      with:
        otp-version: ${{ inputs.otp_version }}
        version-type: strict
-
    - name: Build Elixir Release
      shell: bash
-      run: | # zizmor: ignore[github-env]
+      run: |
        make Precompiled.zip
-        mv Precompiled.zip "elixir-otp-${INPUT_OTP}.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
-      env:
-        INPUT_OTP: ${{ inputs.otp }}
-
    - name: Install NSIS
      shell: bash
      run: |
        sudo apt update
        sudo apt install -y nsis
-
    - name: Build Elixir Windows Installer
      shell: bash
      run: |
-        export OTP_VERSION="$INPUT_OTP_VERSION"
-        export ELIXIR_ZIP="$PWD/elixir-otp-${INPUT_OTP}.zip"
+        export OTP_VERSION=${{ inputs.otp_version }}
+        export ELIXIR_ZIP=$PWD/elixir-otp-${{ inputs.otp }}.zip
        (cd lib/elixir/scripts/windows_installer && ./build.sh)
-        mv "lib/elixir/scripts/windows_installer/tmp/elixir-otp-${INPUT_OTP}.exe" .
-      env:
-        INPUT_OTP: ${{ inputs.otp }}
-        INPUT_OTP_VERSION: ${{ inputs.otp_version }}
+        mv lib/elixir/scripts/windows_installer/tmp/elixir-otp-${{ inputs.otp }}.exe .
+        shasum -a 1   elixir-otp-${{ inputs.otp }}.exe > elixir-otp-${{ inputs.otp }}.exe.sha1sum
+        shasum -a 256 elixir-otp-${{ inputs.otp }}.exe > elixir-otp-${{ inputs.otp }}.exe.sha256sum
    - name: Get ExDoc ref
      if: ${{ inputs.build_docs }}
      shell: bash
-      run: | # zizmor: ignore[github-env]
-        if [ "$GITHUB_REF_NAME" = "main" ]; then
+      run: |
+        if [ "${{ github.ref_name }}" = "main" ]; then
          ref=main
        else
          ref=v$(curl -s https://hex.pm/api/packages/ex_doc | jq --raw-output '.latest_stable_version')
        fi
        echo "EX_DOC_REF=$ref" >> $GITHUB_ENV
-    - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+    - uses: actions/checkout@v3
      if: ${{ inputs.build_docs }}
      with:
        repository: elixir-lang/ex_doc
        ref: ${{ env.EX_DOC_REF }}
        path: ex_doc
-        persist-credentials: false
    - name: Build ex_doc
      if: ${{ inputs.build_docs }}
      shell: bash
@@ -77,5 +64,6 @@ runs:
      if: ${{ inputs.build_docs }}
      shell: bash
      run: |
-        git fetch --tags
        make Docs.zip
+        shasum -a 1 Docs.zip > Docs.zip.sha1sum
+        shasum -a 256 Docs.zip > Docs.zip.sha256sum
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 /doc/
 /lib/*/ebin/
 /lib/*/_build/
@@ -10,10 +6,8 @@
 /lib/elixir/test/ebin/
 /man/elixir.1
 /man/iex.1
-/Docs.zip
-/Precompiled.zip
+/Docs-v*.zip
+/Precompiled-v*.zip
 /.eunit
 .elixir.plt
 erl_crash.dump
-/cover/
-.tool-versions
@@ -1,63 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-// SPDX-FileCopyrightText: 2021 The Elixir Team
-{
-  "globs": [
-    "**/*.md"
-  ],
-  "ignores": [
-    ".git/**",
-    ".github/**"
-  ],
-  "gitignore": true,
-  "config": {
-    // Consecutive header levels (h1 -> h2 -> h3).
-    "MD001": false,
-    // Header style. We use #s.
-    "MD003": {
-      "style": "atx"
-    },
-    // Style of unordered lists..
-    "MD007": {
-      "indent": 2,
-      "start_indented": true
-    },
-    // Line length. Who cares.
-    "MD013": false,
-    // This warns if you have "console" or "shell" code blocks with a dollar sign $ that
-    // don't show output. We use those a lot, so this is fine for us.
-    "MD014": false,
-    // Multiple headings with the same content.
-    "MD024": {
-      // Duplication is allowed for headings with different parents.
-      "siblings_only": true
-    },
-    // Trailing punctuation in heading.
-    // Some headers finish with ! because it refers to a function name. Therefore we remove ! from
-    // the default values.
-    "MD026": {
-      "punctuation": ".,;:。，；：！"
-    },
-    // Allow empty line between block quotes. Used by contiguous admonition blocks.
-    "MD028": false,
-    // Allowed HTML inline elements.
-    "MD033": {
-      "allowed_elements": [
-        "h1",
-        "a",
-        "br",
-        "img",
-        "picture",
-        "source",
-        "noscript",
-        "p",
-        "script"
-      ]
-    },
-    // This warns if you have spaces in code blocks. Sometimes, that's fine.
-    "MD038": false,
-    // Code block style. We don't care if it's fenced or indented.
-    "MD046": false,
-    // Our tables are too large to align.
-    "MD060": false
-  }
-}
@@ -0,0 +1,42 @@
+{
+  // Consecutive header levels (h1 -> h2 -> h3). We don't care about this.
+  "MD001": false,
+  // Header style. We use #s.
+  "MD003": {
+    "style": "atx"
+  },
+  // Style of unordered lists..
+  "MD007": {
+    "indent": 2,
+    "start_indented": true
+  },
+  // Line length. Who cares.
+  "MD013": false,
+  // This warns if you have "console" or "shell" code blocks with a dollar sign $ that
+  // don't show output. We use those a lot, so this is fine for us.
+  "MD014": false,
+  // Multiple headings with the same content. That's fine.
+  "MD024": false,
+  // Some headers finish with ! because it refers to a function name
+  "MD026": false,
+  // Allow empty line between block quotes. Used by contiguous admonition blocks.
+  "MD028": false,
+  // Allowed HTML inline elements.
+  "MD033": {
+    "allowed_elements": [
+      "h1",
+      "a",
+      "br",
+      "img",
+      "picture",
+      "source",
+      "noscript",
+      "p",
+      "script"
+    ]
+  },
+  // This warns if you have spaces in code blocks. Sometimes, that's fine.
+  "MD038": false,
+  // Code block style. We don't care if it's fenced or indented.
+  "MD046": false
+}
@@ -1,123 +0,0 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-
-excludes:
-  paths:
-    - pattern: "man/*"
-      reason: "DOCUMENTATION_OF"
-      comment: "Documentation"
-    - pattern: ".github/**/*"
-      reason: "BUILD_TOOL_OF"
-      comment: "Documentation"
-    - pattern: ".ort/**/*"
-      reason: "BUILD_TOOL_OF"
-      comment: "Documentation"
-
-    # Unfortunately we'll have to repeat all package level excludes here
-    # Make sure to keep them in sync with the package configuration in
-    # .ort/package-configurations
-    - pattern: "lib/*/pages/**/*"
-      reason: "DOCUMENTATION_OF"
-      comment: "Documentation"
-    - pattern: "lib/*/test/**/*"
-      reason: "TEST_OF"
-      comment: "Tests"
-    - pattern: "lib/*/scripts/**/*"
-      reason: "BUILD_TOOL_OF"
-      comment: "Build Tool"
-    - pattern: "lib/*/examples/**/*"
-      reason: "EXAMPLE_OF"
-      comment: "Example"
-
-curations:
-  license_findings:
-    # Version File
-    - path: "VERSION"
-      reason: "NOT_DETECTED"
-      comment: "Apply Trademark Policy to VERSION file"
-      detected_license: "NONE"
-      concluded_license: "Apache-2.0"
-    - path: ".github/pull_request_template.md"
-      reason: "NOT_DETECTED"
-      comment: "Apply default license to GitHub pull request template"
-      detected_license: "NONE"
-      concluded_license: "Apache-2.0"
-
-    # Wrongly Identified
-    - path: ".gitignore"
-      reason: "INCORRECT"
-      comment: "Ignored by ScanCode"
-      detected_license: "NONE"
-      concluded_license: "Apache-2.0"
-    - path: ".gitattributes"
-      reason: "INCORRECT"
-      comment: "Ignored by ScanCode"
-      detected_license: "NONE"
-      concluded_license: "Apache-2.0"
-    - path: "CONTRIBUTING.md"
-      reason: "INCORRECT"
-      comment: "Wrongly identified TSL license"
-      detected_license: "Apache-2.0 OR NOASSERTION OR LicenseRef-scancode-tsl-2020"
-      concluded_license: "Apache-2.0"
-    - path: "OPEN_SOURCE_POLICY.md"
-      reason: "INCORRECT"
-      comment: "Wrongly identified NOASSERTION"
-      detected_license: "NOASSERTION"
-      concluded_license: "Apache-2.0"
-
-    # Unfortunately we'll have to repeat all package level license curations here
-    # Make sure to keep them in sync with the package configuration in
-    # .ort/package-configurations
-
-    # Test Fixtures
-    - path: "lib/*/test/fixtures/**/*"
-      reason: "NOT_DETECTED"
-      comment: "Apply default license to test fixtures"
-      detected_license: "NONE"
-      concluded_license: "Apache-2.0"
-
-    # Logos
-    - path: "lib/elixir/pages/images/logo.png"
-      reason: "NOT_DETECTED"
-      comment: "Apply Trademark Policy to Elixir Logo"
-      detected_license: "NONE"
-      concluded_license: "LicenseRef-elixir-trademark-policy"
-    - path: "lib/elixir/scripts/windows_installer/assets/Elixir.ico"
-      reason: "NOT_DETECTED"
-      comment: "Apply Trademark Policy to Elixir Logo"
-      detected_license: "NONE"
-      concluded_license: "LicenseRef-elixir-trademark-policy"
-
-    # Documentation Images
-    - path: "lib/elixir/pages/images/**/*.png"
-      reason: "NOT_DETECTED"
-      comment: "Apply default license to all images"
-      detected_license: "NONE"
-      concluded_license: "Apache-2.0"
-
-    # Test Fixtures
-    - path: "lib/elixir/test/elixir/fixtures/**/*"
-      reason: "NOT_DETECTED"
-      comment: "Apply default license to test fixtures"
-      detected_license: "NONE"
-      concluded_license: "Apache-2.0"
-
-    # Unicode
-    - path: "lib/elixir/unicode/*.txt"
-      reason: "NOT_DETECTED"
-      comment: "Apply default license to unicode files"
-      detected_license: "NONE"
-      concluded_license: "LicenseRef-scancode-unicode"
-
-    # Wrongly Identified
-    - path: "lib/elixir/pages/references/library-guidelines.md"
-      reason: "INCORRECT"
-      comment: |
-        The guide mentions multiple licenses for users to choose from.
-        It however is not licensed itself by the mentioned licenses.
-      concluded_license: "Apache-2.0"
-    - path: "lib/elixir/scripts/windows_installer/.gitignore"
-      reason: "INCORRECT"
-      comment: "Ignored by ScanCode"
-      detected_license: "NONE"
-      concluded_license: "Apache-2.0"
@@ -1,21 +0,0 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-
-ort:
-  enableRepositoryPackageCurations: true
-  enableRepositoryPackageConfigurations: true
-
-  scanner:
-    skipConcluded: false
-    includeFilesWithoutFindings: true
-
-  analyzer:
-    allowDynamicVersions: true
-    enabledPackageManagers: [SpdxDocumentFile]
-
-  reporter:
-    reporters:
-      SpdxDocument:
-        options:
-          creationInfoOrganization: The Elixir Team
-          documentName: "Elixir Source SPDX Document"
@@ -1,88 +0,0 @@
-/*
- * Copyright (C) 2019 The ORT Project Authors (see <https://github.com/oss-review-toolkit/ort/blob/main/NOTICE>)
- * Copyright (c) 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.
- * You may obtain a copy of the License at
- *
- *     https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- * SPDX-License-Identifier: Apache-2.0
- */
-
- // Docs: https://oss-review-toolkit.org/ort/docs/configuration/evaluator-rules
-
-val whitelistedLicenses = listOf(
-  // License for Elixir & Imported Erlang Projects
-  "Apache-2.0",
-  // License for the Elixir Logo
-  "LicenseRef-elixir-trademark-policy",
-  "LicenseRef-scancode-elixir-trademark-policy",
-  // License for included Unicode Files
-  "LicenseRef-scancode-unicode",
-  // DCO for committers
-  "LicenseRef-scancode-dco-1.1"
-).map { SpdxSingleLicenseExpression.parse(it) }.toSet()
-
-fun PackageRule.howToFixDefault() = """
-      * Check if this license violation is intended
-      * Adjust evaluation rules in `.ort/config/evaluator.rules.kts`
-    """.trimIndent()
-
-fun PackageRule.LicenseRule.isHandled() =
-  object : RuleMatcher {
-    override val description = "isHandled($license)"
-
-    override fun matches() = license in whitelistedLicenses
-  }
-
-fun RuleSet.unhandledLicenseRule() = packageRule("UNHANDLED_LICENSE") {
-  // Do not trigger this rule on packages that have been excluded in the .ort.yml.
-  require {
-    -isExcluded()
-  }
-
-  // Define a rule that is executed for each license of the package.
-  licenseRule("UNHANDLED_LICENSE", LicenseView.CONCLUDED_OR_DECLARED_AND_DETECTED) {
-    require {
-      -isExcluded()
-      -isHandled()
-    }
-
-    // Throw an error message including guidance how to fix the issue.
-    error(
-      "The license $license is currently not covered by policy rules. " +
-        "The license was ${licenseSource.name.lowercase()} in package " +
-        "${pkg.metadata.id.toCoordinates()}.",
-      howToFixDefault()
-    )
-  }
-}
-
-fun RuleSet.unmappedDeclaredLicenseRule() = packageRule("UNMAPPED_DECLARED_LICENSE") {
-  require {
-    -isExcluded()
-  }
-
-  resolvedLicenseInfo.licenseInfo.declaredLicenseInfo.processed.unmapped.forEach { unmappedLicense ->
-    warning(
-      "The declared license '$unmappedLicense' could not be mapped to a valid license or parsed as an SPDX " +
-        "expression. The license was found in package ${pkg.metadata.id.toCoordinates()}.",
-      howToFixDefault()
-    )
-  }
-}
-
-val ruleSet = ruleSet(ortResult, licenseInfoResolver, resolutionProvider) {
-  unhandledLicenseRule()
-  unmappedDeclaredLicenseRule()
-}
-
-ruleViolations += ruleSet.violations
@@ -1,15 +0,0 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-
-id: "SpdxDocumentFile:The Elixir Team:eex:"
-path_excludes:
-  - pattern: "lib/eex/test/**/*"
-    reason: "TEST_OF"
-    comment: "Tests"
-license_finding_curations:
-  # Test Fixtures
-  - path: "lib/eex/test/fixtures/**/*"
-    reason: "NOT_DETECTED"
-    comment: "Apply default license to test fixtures"
-    detected_license: "NONE"
-    concluded_license: "Apache-2.0"
@@ -1,60 +0,0 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-
-id: "SpdxDocumentFile:The Elixir Team:elixir:"
-path_excludes:
-  - pattern: "lib/elixir/pages/**/*"
-    reason: "DOCUMENTATION_OF"
-    comment: "Documentation"
-  - pattern: "lib/elixir/scripts/**/*"
-    reason: "BUILD_TOOL_OF"
-    comment: "Build Tool"
-  - pattern: "lib/elixir/test/**/*"
-    reason: "TEST_OF"
-    comment: "Tests"
-license_finding_curations:
-  # Logos
-  - path: "lib/elixir/pages/images/logo.png"
-    reason: "NOT_DETECTED"
-    comment: "Apply Trademark Policy to Elixir Logo"
-    detected_license: "NONE"
-    concluded_license: "LicenseRef-elixir-trademark-policy"
-  - path: "lib/elixir/scripts/windows_installer/assets/Elixir.ico"
-    reason: "NOT_DETECTED"
-    comment: "Apply Trademark Policy to Elixir Logo"
-    detected_license: "NONE"
-    concluded_license: "LicenseRef-elixir-trademark-policy"
-
-  # Documentation Images
-  - path: "lib/elixir/pages/images/**/*.png"
-    reason: "NOT_DETECTED"
-    comment: "Apply default license to all images"
-    detected_license: "NONE"
-    concluded_license: "Apache-2.0"
-
-  # Test Fixtures
-  - path: "lib/elixir/test/elixir/fixtures/**/*"
-    reason: "NOT_DETECTED"
-    comment: "Apply default license to test fixtures"
-    detected_license: "NONE"
-    concluded_license: "Apache-2.0"
-
-  # Unicode
-  - path: "lib/elixir/unicode/*.txt"
-    reason: "NOT_DETECTED"
-    comment: "Apply default license to unicode files"
-    detected_license: "NONE"
-    concluded_license: "LicenseRef-scancode-unicode"
-
-  # Wrongly Identified
-  - path: "lib/elixir/pages/references/library-guidelines.md"
-    reason: "INCORRECT"
-    comment: |
-      The guide mentions multiple licenses for users to choose from.
-      It however is not licensed itself by the mentioned licenses.
-    concluded_license: "Apache-2.0"
-  - path: "lib/elixir/scripts/windows_installer/.gitignore"
-    reason: "INCORRECT"
-    comment: "Ignored by ScanCode"
-    detected_license: "NONE"
-    concluded_license: "Apache-2.0"
@@ -1,18 +0,0 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-
-id: "SpdxDocumentFile:The Elixir Team:exunit:"
-path_excludes:
-  - pattern: "lib/ex_unit/examples/**/*"
-    reason: "EXAMPLE_OF"
-    comment: "Example"
-  - pattern: "lib/ex_unit/test/**/*"
-    reason: "TEST_OF"
-    comment: "Tests"
-license_finding_curations:
-  # Test Fixtures
-  - path: "lib/ex_unit/test/fixtures/**/*"
-    reason: "NOT_DETECTED"
-    comment: "Apply default license to test fixtures"
-    detected_license: "NONE"
-    concluded_license: "Apache-2.0"
@@ -1,8 +0,0 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-
-id: "SpdxDocumentFile:The Elixir Team:logger:"
-path_excludes:
-  - pattern: "lib/logger/test/**/*"
-    reason: "TEST_OF"
-    comment: "Tests"
@@ -1,15 +0,0 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-
-id: "SpdxDocumentFile:The Elixir Team:mix:"
-path_excludes:
-  - pattern: "lib/mix/test/**/*"
-    reason: "TEST_OF"
-    comment: "Tests"
-license_finding_curations:
-  # Test Fixtures
-  - path: "lib/mix/test/fixtures/**/*"
-    reason: "NOT_DETECTED"
-    comment: "Apply default license to test fixtures"
-    detected_license: "NONE"
-    concluded_license: "Apache-2.0"
@@ -1 +0,0 @@
-CONTRIBUTING.md
@@ -1,111 +1,167 @@
-<!--
-  SPDX-License-Identifier: Apache-2.0
-  SPDX-FileCopyrightText: 2021 The Elixir Team
-  SPDX-FileCopyrightText: 2012 Plataformatec
-->
+# Changelog for Elixir v1.17

-# Changelog for Elixir v1.21
+## Warnings from gradual set-theoretic types

-## v1.21.0-dev
+This release introduces gradual set-theoretic types to infer types from patterns and guards and use them to type check programs, enabling the Elixir compiler to find faults and bugs in codebases without requiring changes to existing software. The underlying principles, theory, and roadmap of our work have been outlined in ["The Design Principles of the Elixir Type System" by Giuseppe Castagna, Guillaume Duboc, José Valim](https://arxiv.org/abs/2306.06391).
+
+At the moment, Elixir developers will interact with set-theoretic types only through warnings found by the type system. The current implementation models all data types in the language:
+
+  * `binary()`, `integer()`, `float()`, `pid()`, `port()`, `reference()` - these types are indivisible. This means both `1` and `13` get the same `integer()` type.
+
+  * `atom()` - it represents all atoms and it is divisible. For instance, the atom `:foo` and `:hello_world` are also valid (distinct) types.
+
+  * `map()` and structs - maps can be "closed" or "open". Closed maps only allow the specified allows keys, such as `%{key: atom(), value: integer()}`. Open maps support any other keys in addition to the ones listed and their definition starts with `...`, such as `%{..., key: atom(), value: integer()}`. Structs are closed maps with the `__struct__` key.
+
+  * `tuple()`, `list()`, and `function()` - currently they are modelled as indivisible types. The next Elixir versions will also introduce fine-grained support to them.
+
+We focused on atoms and maps on this initial release as they are respectively the simplest and the most complex types representations, so we can stress the performance of the type system and quality of error messages. Modelling these types will also provide the most immediate benefits to Elixir developers. Assuming there is a variable named `user`, holding a `%User{}` struct with an `address` field, Elixir v1.17 will emit the following warnings at compile-time:
+
+  * Pattern matching against a map or a struct that does not have the given key, such as `%{adress: ...} = user` (notice `address` vs `adress`)
+
+  * Accessing a key on a map or a struct that does not have the given key, such as `user.adress`
+
+  * Updating a struct or a map that does not define the given key, such as `%{user | adress: ...}`
+
+  * Invoking a function on non-modules, such as `user.address()`
+
+  * Capturing a function on non-modules, such as `&user.address/0`
+
+  * Performing structural comparisons with structs, such as `my_date < ~D[2010-04-17]`
+
+  * Performing structural comparisons between non-overlapping types, such as `integer >= string`
+
+  * Building and pattern matching on binaries without the relevant specifiers, such as `<<string>>` (this warns because by default it expects an integer)
+
+  * Attempting to rescue an undefined exception or an exception that is not a struct
+
+  * Accessing a field that is not defined in a rescued exception
+
+These new warnings help Elixir developers find bugs earlier and give more confidence when refactoring code, especially around maps and structs. While some of these warnings were emitted in the past, they were discovered using syntax analysis. The new warnings are more reliable, precise, and with better error messages. Keep in mind that not all maps have statically known keys, and the Elixir typechecker only infers types from patterns at the moment.
+
+Future Elixir versions will infer and type check more constructs, bringing Elixir developers more warnings and quality of life improvements without changes to code. For more details, see our new [reference document on gradual set-theoretic types](https://hexdocs.pm/elixir/main/gradual-set-theoretic-types.html).
+
+The type system was made possible thanks to a partnership between [CNRS](https://www.cnrs.fr/) and [Remote](https://remote.com/). The development work is currently sponsored by [Fresha](https://www.fresha.com/), [Starfish*](https://starfish.team/), and [Dashbit](https://dashbit.co/).
+
+## Erlang/OTP support
+
+This release adds support for Erlang/OTP 27 and drops support for Erlang/OTP 24. We recommend Elixir developers to migrate to Erlang/OTP 26 or later, especially on Windows. Support for WERL (a graphical user interface for the Erlang terminal on Windows) will be removed in Elixir v1.18.
+
+## Adding `Duration` and `shift/2` functions
+
+Elixir introduces the `Duration` data type and APIs to shift dates, times, and date times by a given duration, considering different calendars and time zones.
+
+```elixir
+iex> Date.shift(~D[2016-01-31], month: 2)
+~D[2016-03-31]
+```
+
+Note the operation is called `shift` (instead of `add`) since working with durations does not obey properties such as associativity. For instance, adding one month and then one month does not give the same result as adding two months:
+
+```elixir
+iex> ~D[2016-01-31] |> Date.shift(month: 1) |> Date.shift(month: 1)
+~D[2016-03-29]
+```
+
+Still, durations are essential for building intervals, recurring events, and modelling scheduling complexities found in the world around us. For `DateTime`s, Elixir will correctly deal with time zone changes (such as Daylight Saving Time), but provisions are also available in case you want to surface conflicts (for example, you shifted to a wall clock that does not exist, because the clock has been moved forward by one hour). See `DateTime.shift/2` for examples.
+
+Finally, a new `Kernel.to_timeout/1` function has been added, which helps developers normalize durations and integers to a timeout used by Process APIs. For example, to send a message after one hour, one can now write:
+
+```elixir
+Process.send_after(pid, :wake_up, to_timeout(hour: 1))
+```
+
+## v1.17.0-rc.0 (2024-05-24)

 ### 1. Enhancements

-#### EEx
-
-  * [EEx] Support splitting middle expressions across EEx clauses
-
 #### Elixir

-  * [Access] Add support for keyword lists in `Access.key/2` and `Access.key!/1`
-  * [Code] Add support for the `:erlc_options` compiler option
-  * [Code.Formatter] Add a `:migrate_atom_interpolations` option
-  * [Kernel] Improve performance of type constructors and complex intersections
-  * [Kernel] Warn on binary patterns with segments that are not byte-aligned
-  * [Kernel.ParallelCompiler] Add a hint when spawned processes cannot load modules defined during compilation
-  * [Keyword] Optimize `Keyword.pop/3`, `Keyword.pop!/2`, and `Keyword.pop_lazy/3`
-  * [List] Add `List.to_existing_atom/2` and `List.to_unsafe_atom/1`
-  * [MapSet] Optimize `MapSet.symmetric_difference/2` when set sizes differ
-  * [Path] Add `Path.safe_join/2`
-  * [Registry] Optimize exact key matching in lookups
-  * [String] Optimize `String.bag_distance/2`
-  * [String] Add `String.to_existing_atom/2` and `String.to_unsafe_atom/1`
-  * [URI] Optimize percent-decoding and `URI.to_string/1`
+  * [Access] Add `Access.find/1` that mirrors `Enum.find/2`
+  * [Code] Support cursor inside fn/rescue/catch/else/after inside `Code.Fragment.container_cursor_to_quoted/2`
+  * [Date] Add `Date.shift/2` to shift dates with duration and calendar-specific semantics
+  * [Date] Allow `Date` to accept years outside of `-9999..9999` range
+  * [DateTime] Add `DateTime.shift/2` to shift datetimes with duration and calendar-specific semantics
+  * [Duration] Add a new `Duration` data type
+  * [GenServer] Add `c:GenServer.format_status/1` callback
+  * [Kernel] Add `Kernel.get_in/1` with safe nil-handling for access and structs
+  * [Kernel] Add `Kernel.is_non_struct_map/1` guard
+  * [Kernel] Add `Kernel.to_timeout/1`
+  * [Kernel] Emit warnings for undefined functions from modules defined within the same context as the caller code
+  * [Kernel] Support integers in uppercase sigils
+  * [Macro] Add `Macro.Env.define_alias/4`, `Macro.Env.define_import/4`, `Macro.Env.define_require/4`, `Macro.Env.expand_alias/4`, `Macro.Env.expand_import/5`, and `Macro.Env.expand_require/6` to aid the implementation of language servers and embedded languages
+  * [NaiveDateTime] Add `NaiveDateTime.shift/2` to shift naive datetimes with duration and calendar-specific semantics
+  * [Process] Add `Process.set_label/1`
+  * [String] Add `String.byte_slice/3` to slice a string to a maximum number of bytes while keeping it UTF-8 encoded
+  * [System] Support `use_stdio: false` in `System.cmd/3` and `System.shell/2`
+  * [Time] Add `Time.shift/2` to shift times with duration and calendar-specific semantics

 #### ExUnit

-  * [ExUnit.Assertions] Add `trace/3` helper
+  * [ExUnit] Propagate the test process itself as a caller in `start_supervised`
+  * [ExUnit] Include max cases in ExUnit reports
+
+#### IEx
+
+  * [IEx.Helpers] Warns if `recompile` was called and the current working directory changed
+  * [IEx.Helpers] Add `c/0` as an alias to `continue/0`
+  * [IEx.Pry] Add `IEx.Pry.annotate_quoted/3` to annotate a quoted expression with pry breakpoints
+
+#### Logger
+
+  * [Logger] Format `:gen_statem` reports using Elixir data structures
+  * [Logger] Include process label in logger events
+
+#### Mix
+
+  * [mix deps] Add `:depth` option to `Mix.SCM.Git`, thus supporting shallow clones of Git dependencies
+  * [mix deps] Warn if `:optional` is used in combination with `:in_umbrella`
+  * [mix deps.get] Do not add optional dependency requirements if its parent dep was skipped
+  * [mix deps.tree] Add `--umbrella-only` to `mix deps.tree`
+  * [mix test] Add `mix test --breakpoints` that sets up a breakpoint before each test that will run
+  * [mix test] Add `mix test --repeat-until-failure` to rerun tests until a failure occurs
+  * [mix test] Add `mix test --slowest-modules` to print slowest modules based on all of the tests they hold

 ### 2. Bug fixes

 #### Elixir

-  * [Calendar] Fix `Calendar.strftime/3` formatting of negative years with `%y`
-  * [Calendar] Fix rounding for `:day`, `:hour`, and `:minute` units in `DateTime.diff/3`, `NaiveDateTime.diff/3`, and `Time.diff/3`
-  * [Calendar.ISO] Fix `Calendar.ISO.valid_time?/4` to reject non-integer microsecond precision
-  * [Calendar.ISO] Reject negative zero UTC offsets in basic formats
-  * [Code.Formatter] Fix rendering calls where `do` is followed by non-block keyword arguments
-  * [Code.Fragment] Fix cursor completion when operator keywords such as `in`, `when`, `and`, `or`, and `not` follow another operator
-  * [Date] Preserve the `:format` option in `Date.to_iso8601/2` with custom calendars
-  * [Date.Range] Fix slicing date ranges with stepped ranges
-  * [Duration] Reject duplicate seconds in `Duration.from_iso8601/1`
-  * [Enum] Fix `Enum.min/2,3` and `Enum.max/2,3` with custom sorters on ranges
-  * [IO.ANSI.Docs] Recognize additional punctuation delimiters when rendering Markdown
-  * [Kernel] Fix expansion of rebound variables in bitstring size expressions
-  * [Kernel] Expand `defguard` macros separately in guard and body contexts, preserving `and`/`or` error semantics outside guards
-  * [Kernel] Fix inferred stacktrace types to allow arbitrary keyword metadata
-  * [Kernel] Fix inferred types for functions with non-returning clauses
-  * [Kernel] Fix map field type inference in the presence of empty map types
-  * [Kernel] Fix tuple fetch and deletion type operations across equivalent tuple types
-  * [Kernel] Fix variables defined in one default argument leaking into subsequent default arguments
-  * [Kernel] Improve the error message for non-atom struct keys
-  * [Kernel] Raise when `|` is used in guards
-  * [Kernel.Typespec] Preserve metadata when proxying to Elixir typespecs
-  * [Keyword] Delete duplicate keys when `Keyword.get_and_update/3` and `Keyword.get_and_update!/3` return `:pop`
-  * [Macro] Properly escape C1 control characters and Unicode noncharacters
-  * [NaiveDateTime] Fix `NaiveDateTime.diff/3` over-counting incomplete units
-  * [Range] Fix `Range.disjoint?/2` for ranges beyond floating-point precision
-  * [Range] Fix `Range.disjoint?/2` for single-element ranges with a negative step
-  * [String] Fix `String.reverse/1` grapheme ordering around invalid UTF-8 bytes
-  * [String] Return `1.0` from `String.bag_distance/2` for two empty strings
-  * [Time] Validate microseconds in `Time.from_seconds_after_midnight/3`
-
-#### ExUnit
-
-  * [ExUnit.Assertions] Fix `refute_in_delta/4` at the delta boundary and with negative deltas
-  * [ExUnit.CaptureIO] Stop `StringIO` processes when capturing a named device fails
+  * [bin/elixir.bat] Improve handling of quotes and exclamation marks in flags
+  * [Code] Address a bug where AST nodes for `(a -> b)` were not wrapped as part of the literal encoder
+  * [Kernel] Resolve inconsistencies of how `..` and `...` are handled at the AST level
+  * [Kernel] Fix parsing precedence of ambiguous operators followed by containers
+  * [Kernel] Do not expand code in `quote bind_quoted: ...` twice
+  * [Kernel] Respect `:line` property when `:file` is given as option to `quote`
+  * [Kernel] Do not crash on `Macro.escape/2` when passing a quote triplet without valid meta
+  * [Module] Return default value in `Module.get_attribute/3` for persisted attributes which have not yet been written to

 #### IEx

-  * [IEx.Autocomplete] Fix completion crashes on maps with non-atom keys
-  * [IEx.Evaluator] Recognize `**` and `not in` as continuation operators
-  * [IEx.Helpers] Fix `r/1` when multiple modules are defined in the same file
-  * [IEx.Helpers] Fix heap and stack memory calculations in `process_info/1`
+  * [IEx.Helpers] Update the history size whenever history is pruned

 #### Mix

-  * [Mix] Prevent synchronization lock files from being overwritten with empty contents
-  * [Mix.Release] Accept chardata paths in `Mix.Release.make_boot_script/4`
-  * [Mix.SCM.Git] Raise if Git refspecs start with `-`
-  * [mix deps] Recompile path and fetchable dependencies when one of the dependencies they were compiled with is removed
-  * [mix deps] Mark fetchable dependencies for compilation when their build exists but their SCM manifest is missing
-  * [mix deps.compile] Preserve code paths and compiler options across OS partitions
-  * [mix format] Pass `:sigils` to plugins invoked for sigils, allowing nested sigils to be formatted
-  * [mix new] Avoid trailing whitespace in generated files
+  * [mix deps] Fix error message for diverged SCM definition in sibling

-### 3. Hard deprecations
+### 3. Soft deprecations (no warnings emitted)

 #### Elixir

-  * [Macro.Env] `Macro.Env.fetch_alias/2` and `Macro.Env.fetch_macro_alias/2` are deprecated, use `Macro.Env.expand_alias/4` instead
+  * [GenServer] Deprecate `c:GenServer.format_status/2` callback to align with Erlang/OTP 25+

-### 4. Soft deprecations
+### 4. Hard deprecations

 #### Elixir

-  * [Kernel] Atom interpolation (`:"foo_#{bar}"`) is deprecated in favor of explicit `String.to_unsafe_atom/1`
-  * [List] `List.to_atom/1` is deprecated in favor of `List.to_unsafe_atom/1`
-  * [String] `String.to_atom/1` is deprecated in favor of `String.to_unsafe_atom/1`
+  * [IO] Passing `:all` to `IO.read/2` and `IO.binread/2` is deprecated, pass `:eof` instead
+  * [Kernel] Single-quote charlists are deprecated, use `~c` instead
+  * [Kernel] Deprecate escaping closing delimiter in uppercase sigils
+  * [Range] `left..right` without explicit steps inside patterns and guards is deprecated, write `left..right//step` instead
+  * [Range] Decreasing ranges, such as `10..1` without an explicit step is deprecated, write `10..1//-1` instead

-## v1.20
+#### ExUnit

-The CHANGELOG for v1.20 releases can be found [in the v1.20 branch](https://github.com/elixir-lang/elixir/blob/v1.20/CHANGELOG.md).
+  * [ExUnit.Case] `register_test/4` is deprecated in favor of `register_test/6` for performance reasons
+
+## v1.16
+
+The CHANGELOG for v1.16 releases can be found [in the v1.16 branch](https://github.com/elixir-lang/elixir/blob/v1.16/CHANGELOG.md).
@@ -1,12 +1,6 @@
-<!--
-  SPDX-License-Identifier: Apache-2.0
-  SPDX-FileCopyrightText: 2021 The Elixir Team
-  SPDX-FileCopyrightText: 2012 Plataformatec
-->
-
 # Code of Conduct

-Contact: <elixir-lang-conduct@googlegroups.com>
+Contact: elixir-lang-conduct@googlegroups.com

 ## Why have a Code of Conduct?

@@ -51,15 +45,15 @@ If you participate in or contribute to the Elixir ecosystem in any way, you are

 Explicit enforcement of the Code of Conduct applies to the official mediums operated by the Elixir project:

-  * The [official GitHub projects][1] and code reviews.
-  * The official elixir-lang mailing lists.
-  * The **[#elixir][2]** IRC channel on [Libera.Chat][3].
+* The [official GitHub projects][1] and code reviews.
+* The official elixir-lang mailing lists.
+* The **[#elixir][2]** IRC channel on [Libera.Chat][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.

-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**.
+Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by emailing: elixir-lang-conduct@googlegroups.com. All complaints will be reviewed and investigated and will result in a response that is deemed necessary and appropriate to the circumstances. **All reports will be kept confidential**.

 **The goal of the Code of Conduct is to resolve conflicts in the most harmonious way possible**. We hope that in most cases issues may be resolved through polite discussion and mutual agreement. Bannings and other forceful measures are to be employed only as a last resort. **Do not** post about the issue publicly or try to rally sentiment against a particular individual or group.

@@ -1,244 +0,0 @@
-<!--
-  SPDX-License-Identifier: Apache-2.0
-  SPDX-FileCopyrightText: 2021 The Elixir Team
-  SPDX-FileCopyrightText: 2012 Plataformatec
-->
-
-# Contributing to Elixir
-
-We invite contributions to Elixir. To contribute, there are a few
-things you need to know about the code. First, Elixir code is divided
-by each application inside the `lib` folder:
-
-  * `elixir` - Elixir's kernel and standard library
-
-  * `eex` - EEx is the template engine that allows you to embed Elixir
-
-  * `ex_unit` - ExUnit is a simple test framework that ships with Elixir
-
-  * `iex` - IEx stands for Interactive Elixir: Elixir's interactive shell
-
-  * `logger` - Logger is the built-in logger
-
-  * `mix` - Mix is Elixir's build tool
-
-You can run all tests in the root directory with `make test`. You can
-also run tests for a specific framework with `make test_#{APPLICATION}`, for example,
-`make test_ex_unit`. If you just changed something in Elixir's standard
-library, you can run only that portion through `make test_stdlib`.
-
-If you are only changing one file, you can choose to compile and run tests
-for that specific file for faster development cycles. For example, if you
-are changing the String module, you can compile it and run its tests as:
-
-```sh
-bin/elixirc lib/elixir/lib/string.ex -o lib/elixir/ebin
-bin/elixir lib/elixir/test/elixir/string_test.exs
-```
-
-Some test files need their `test_helper.exs` to be explicitly required
-before, such as:
-
-```sh
-bin/elixir -r lib/logger/test/test_helper.exs lib/logger/test/logger_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 all (including Erlang modules):
-
-```sh
-make compile
-```
-
-After your changes are done, run `make format` to guarantee
-all files are properly formatted, then run the full suite with
-`make test`.
-
-If your contribution fails during the bootstrapping of the language,
-you can rebuild the language from scratch with:
-
-```sh
-make clean_elixir compile
-```
-
-Similarly, if you can not 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).
-More tasks can be found by reading the [Makefile](Makefile).
-
-## Sending a pull request
-
-Contributions are done [via pull request](https://help.github.com/articles/using-pull-requests/)
-and must include tests and other relevant proof of work:
-
-  * **Bug Fixes:** If you are fixing a bug, include a test that *fails* before
-    your change and *passes* afterward. This makes it easier to confirm that the
-    fix addresses the underlying issue and helps prevent regressions in the future.
-
-  * **New Features or Major Changes:** If you are adding a new feature or making
-    major changes to existing functionality, please add assocaited tests. Aim to
-    have the best code coverage possible.
-
-  * **Performance improvements:** For performance improvements, please include the
-    benchmark script, with inputs and results, in the pull request description.
-    We recommend using [benchee](https://github.com/bencheeorg/benchee).
-
-Here are some pull requests we have received in the past you can use as reference:
-
-  * [Implement Enum.member?](https://github.com/elixir-lang/elixir/pull/992)
-
-  * [Add String.valid?](https://github.com/elixir-lang/elixir/pull/1058)
-
-  * [Implement capture_io for ExUnit](https://github.com/elixir-lang/elixir/pull/1059)
-
-## Reviewing changes
-
-Once a pull request is sent, the Elixir team will review your changes.
-If changes are necessary, the team will leave appropriate 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.
-
-When the review finishes, your pull request will be squashed and merged
-into the repository. If you have carefully organized your commits and
-believe they should be merged without squashing, please mention it in
-a comment.
-
-## Building documentation
-
-Building the documentation requires that [ExDoc](https://github.com/elixir-lang/ex_doc)
-is cloned and compiled alongside Elixir.
-
-After cloning and compiling Elixir, run:
-
-```sh
-elixir_dir=$(pwd)
-cd .. && git clone https://github.com/elixir-lang/ex_doc.git
-cd ex_doc && "${elixir_dir}/bin/elixir" "${elixir_dir}/bin/mix" do deps.get + compile
-
-# Now we will go back to Elixir's root directory,
-cd "${elixir_dir}"
-
-# and generate HTML and EPUB documents:
-make docs
-```
-
-This will produce documentation sets for `elixir`, `eex`, `ex_unit`, `iex`, `logger`,
-and `mix` under the `doc` directory. If you are planning to contribute documentation,
-[please check our best practices for writing documentation](https://elixir.hexdocs.pm/writing-documentation.html).
-
-## Licensing and Compliance Requirements
-
-Please review our [Open Source Policy](OPEN_SOURCE_POLICY.md) for complete
-guidelines on licensing and compliance. Below is a summary of the key points
-affecting **all external contributors**:
-
-  * Accepted Licenses: Any code contributed must be licensed under the
-    `Apache-2.0` license.
-
-  * SPDX License Headers: With the exception of approved test fixture files,
-    all new or modified files in a pull request must include correct SPDX
-    headers. If you are creating a new file under the `Apache-2.0` license, for
-    instance, please use:
-
-    ```elixir
-    # SPDX-License-Identifier: Apache-2.0
-    # SPDX-FileCopyrightText: 2021 The Elixir Team
-    ```
-
-  * No Executable Binaries: Contributions must **not** include any executable
-    binary files. If you require an exception (for example, certain test artifacts),
-    please see the policy on how to request approval and document exceptions.
-
-  * Preserving Copyright and License Info: If you copy code from elsewhere,
-    ensure that **all original copyright and license notices remain intact**. If
-    they are missing or incomplete, you must add them.
-
-  * Failure to Comply: Pull requests that do not meet these licensing and
-    compliance standards will be rejected or require modifications before merging.
-
-  * Developer Certificate of Origin: All contributions are subject to the
-    Developer Certificate of Origin.
-
-    ```text
-    By making a contribution to this project, I certify that:
-
-    (a) The contribution was created in whole or in part by me and I
-        have the right to submit it under the open source license
-        indicated in the file; or
-
-    (b) The contribution is based upon previous work that, to the 
-        best of my knowledge, is covered under an appropriate open 
-        source license and I have the right under that license to   
-        submit that work with modifications, whether created in whole
-        or in part by me, under the same open source license (unless
-        I am permitted to submit under a different license), as 
-        Indicated in the file; or
-
-    (c) The contribution was provided directly to me by some other
-        person who certified (a), (b) or (c) and I have not modified
-        it.
-
-    (d) I understand and agree that this project and the contribution
-        are public and that a record of the contribution (including 
-        all personal information I submit with it, including my
-        sign-off) is maintained indefinitely and may be redistributed
-        consistent with this project or the open source license(s)
-        involved.
-    ```
-
-    See <https://developercertificate.org/> for a copy of the Developer Certificate
-    of Origin license.
-
-## Using AI and coding agents
-
-While we allow the use of AI on contributions and discussions, please be mindful
-when doing so. Generally speaking, Elixir maintainers already have access to AI
-(like many other developers). Therefore, if we need the feedback or help of a
-coding agent, we can request so ourselves. For this reason, we often find
-the point of view of the human behind the agent more valuable.
-
-That said, here are examples of how one might (or might not) use AI and coding
-agents in Elixir spaces:
-
-  * When it comes to discussions, using AI to help express yourself is welcome,
-    but avoid directly copy and pasting AI generated content. If there is a language
-    barrier, use AI to translate, review, and improve your text, but do not use AI
-    to respond on your behalf.
-
-  * Do not use coding agents to tackle existing issues unless they have the
-    "Contributions Welcome" label.
-
-  * If you request a feature on the mailing list and it is accepted, you may
-    use coding agents to implement it, as long as it follows the AI Contributions
-    guidelines below.
-
-  * When automating AI usage on the Elixir codebase for performance improvements,
-    security fixes, or correctness changes to the compiler or type system, pair it
-    with a separate set of agents whose job is to argue against and try to invalidate
-    any proposed change. And treat their approval as advisory: a human must still
-    validate it before opening issues or pull requests.
-
-If any code is written by AI, then you must follow the guidelines below.
-
-### AI contributions
-
-AI agents MUST NOT add Signed-off-by tags. Only humans can legally certify the Developer
-Certificate of Origin (DCO). The human submitter is responsible for:
-
-  * Reviewing all AI-generated code
-  * Ensuring compliance with licensing requirements
-  * Adding their own Signed-off-by tag to certify the DCO
-  * Taking full responsibility for the contribution
-  * Disclosing use of AI for comments and code contributions
-
-When AI tools contribute to Elixir, proper attribution helps track the evolving role of
-AI in the development process. Contributions should include an Assisted-by tag in the
-following format:
-
-    Assisted-by: AGENT_NAME:MODEL_VERSION
@@ -1,73 +0,0 @@
-Apache License
-Version 2.0, January 2004
-http://www.apache.org/licenses/
-
-TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
-
-1. Definitions.
-
-"License" shall mean the terms and conditions for use, reproduction, and distribution as defined by Sections 1 through 9 of this document.
-
-"Licensor" shall mean the copyright owner or entity authorized by the copyright owner that is granting the License.
-
-"Legal Entity" shall mean the union of the acting entity and all other entities that control, are controlled by, or are under common control with that entity. For the purposes of this definition, "control" means (i) the power, direct or indirect, to cause the direction or management of such entity, whether by contract or otherwise, or (ii) ownership of fifty percent (50%) or more of the outstanding shares, or (iii) beneficial ownership of such entity.
-
-"You" (or "Your") shall mean an individual or Legal Entity exercising permissions granted by this License.
-
-"Source" form shall mean the preferred form for making modifications, including but not limited to software source code, documentation source, and configuration files.
-
-"Object" form shall mean any form resulting from mechanical transformation or translation of a Source form, including but not limited to compiled object code, generated documentation, and conversions to other media types.
-
-"Work" shall mean the work of authorship, whether in Source or Object form, made available under the License, as indicated by a copyright notice that is included in or attached to the work (an example is provided in the Appendix below).
-
-"Derivative Works" shall mean any work, whether in Source or Object form, that is based on (or derived from) the Work and for which the editorial revisions, annotations, elaborations, or other modifications represent, as a whole, an original work of authorship. For the purposes of this License, Derivative Works shall not include works that remain separable from, or merely link (or bind by name) to the interfaces of, the Work and Derivative Works thereof.
-
-"Contribution" shall mean any work of authorship, including the original version of the Work and any modifications or additions to that Work or Derivative Works thereof, that is intentionally submitted to Licensor for inclusion in the Work by the copyright owner or by an individual or Legal Entity authorized to submit on behalf of the copyright owner. For the purposes of this definition, "submitted" means any form of electronic, verbal, or written communication sent to the Licensor or its representatives, including but not limited to communication on electronic mailing lists, source code control systems, and issue tracking systems that are managed by, or on behalf of, the Licensor for the purpose of discussing and improving the Work, but excluding communication that is conspicuously marked or otherwise designated in writing by the copyright owner as "Not a Contribution."
-
-"Contributor" shall mean Licensor and any individual or Legal Entity on behalf of whom a Contribution has been received by Licensor and subsequently incorporated within the Work.
-
-2. Grant of Copyright License. Subject to the terms and conditions of this License, each Contributor hereby grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare Derivative Works of, publicly display, publicly perform, sublicense, and distribute the Work and such Derivative Works in Source or Object form.
-
-3. Grant of Patent License. Subject to the terms and conditions of this License, each Contributor hereby grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable (except as stated in this section) patent license to make, have made, use, offer to sell, sell, import, and otherwise transfer the Work, where such license applies only to those patent claims licensable by such Contributor that are necessarily infringed by their Contribution(s) alone or by combination of their Contribution(s) with the Work to which such Contribution(s) was submitted. If You institute patent litigation against any entity (including a cross-claim or counterclaim in a lawsuit) alleging that the Work or a Contribution incorporated within the Work constitutes direct or contributory patent infringement, then any patent licenses granted to You under this License for that Work shall terminate as of the date such litigation is filed.
-
-4. Redistribution. You may reproduce and distribute copies of the Work or Derivative Works thereof in any medium, with or without modifications, and in Source or Object form, provided that You meet the following conditions:
-
-     (a) You must give any other recipients of the Work or Derivative Works a copy of this License; and
-
-     (b) You must cause any modified files to carry prominent notices stating that You changed the files; and
-
-     (c) You must retain, in the Source form of any Derivative Works that You distribute, all copyright, patent, trademark, and attribution notices from the Source form of the Work, excluding those notices that do not pertain to any part of the Derivative Works; and
-
-     (d) If the Work includes a "NOTICE" text file as part of its distribution, then any Derivative Works that You distribute must include a readable copy of the attribution notices contained within such NOTICE file, excluding those notices that do not pertain to any part of the Derivative Works, in at least one of the following places: within a NOTICE text file distributed as part of the Derivative Works; within the Source form or documentation, if provided along with the Derivative Works; or, within a display generated by the Derivative Works, if and wherever such third-party notices normally appear. The contents of the NOTICE file are for informational purposes only and do not modify the License. You may add Your own attribution notices within Derivative Works that You distribute, alongside or as an addendum to the NOTICE text from the Work, provided that such additional attribution notices cannot be construed as modifying the License.
-
-     You may add Your own copyright statement to Your modifications and may provide additional or different license terms and conditions for use, reproduction, or distribution of Your modifications, or for any such Derivative Works as a whole, provided Your use, reproduction, and distribution of the Work otherwise complies with the conditions stated in this License.
-
-5. Submission of Contributions. Unless You explicitly state otherwise, any Contribution intentionally submitted for inclusion in the Work by You to the Licensor shall be under the terms and conditions of this License, without any additional terms or conditions. Notwithstanding the above, nothing herein shall supersede or modify the terms of any separate license agreement you may have executed with Licensor regarding such Contributions.
-
-6. Trademarks. This License does not grant permission to use the trade names, trademarks, service marks, or product names of the Licensor, except as required for reasonable and customary use in describing the origin of the Work and reproducing the content of the NOTICE file.
-
-7. Disclaimer of Warranty. Unless required by applicable law or agreed to in writing, Licensor provides the Work (and each Contributor provides its Contributions) on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied, including, without limitation, any warranties or conditions of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are solely responsible for determining the appropriateness of using or redistributing the Work and assume any risks associated with Your exercise of permissions under this License.
-
-8. Limitation of Liability. In no event and under no legal theory, whether in tort (including negligence), contract, or otherwise, unless required by applicable law (such as deliberate and grossly negligent acts) or agreed to in writing, shall any Contributor be liable to You for damages, including any direct, indirect, special, incidental, or consequential damages of any character arising as a result of this License or out of the use or inability to use the Work (including but not limited to damages for loss of goodwill, work stoppage, computer failure or malfunction, or any and all other commercial damages or losses), even if such Contributor has been advised of the possibility of such damages.
-
-9. Accepting Warranty or Additional Liability. While redistributing the Work or Derivative Works thereof, You may choose to offer, and charge a fee for, acceptance of support, warranty, indemnity, or other liability obligations and/or rights consistent with this License. However, in accepting such obligations, You may act only on Your own behalf and on Your sole responsibility, not on behalf of any other Contributor, and only if You agree to indemnify, defend, and hold each Contributor harmless for any liability incurred by, or claims asserted against, such Contributor by reason of your accepting any such warranty or additional liability.
-
-END OF TERMS AND CONDITIONS
-
-APPENDIX: How to apply the Apache License to your work.
-
-To apply the Apache License to your work, attach the following boilerplate notice, with the fields enclosed by brackets "[]" replaced with your own identifying information. (Don't include the brackets!)  The text should be enclosed in the appropriate comment syntax for the file format. We also recommend that a file or class name and description of purpose be included on the same "printed page" as the copyright notice for easier identification within third-party archives.
-
-Copyright [yyyy] [name of copyright owner]
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
@@ -1,98 +0,0 @@
-ELIXIR TEAM TRADEMARKS POLICY
-
-This document outlines the policy for allowed usage of the “Elixir” word and the
-Elixir logo by other parties.
-
-“Elixir” and the Elixir logo are registered trademarks of the Elixir Team. The
-Elixir Team believes in a decentralized approach to growing the community and
-the ecosystem, independent of the Elixir project and the Elixir Team.
-
-Anyone can use the Elixir trademarks if that use of the trademark is nominative.
-The trademarks must not be used to disparage the project and its community, nor
-be used in any way to imply ownership, endorsement, or association with the
-Elixir project and the Elixir Team.
-
-You must not visually combine the Elixir logo with any other images, or change
-the logo in any way other than ways required by printing restrictions. If you
-want to create your own visual identity in relation to Elixir, you might use the
-shape of an unrelated “water drop” as part of your design, as seen in many
-community projects and initiatives. You must not combine or modify the Elixir
-logo.
-
-The Elixir logo is available in our repository in both vertical and horizontal
-versions.
-
-Nominative use
-The “nominative use” (or “nominative fair use”) is a legal doctrine that
-authorizes everyone (even commercial companies) to use or refer to the trademark
-of another if:
-
-The product or service in question must be one not readily identifiable without
-use of the trademark.
-
-Only so much of the mark or marks may be used as is reasonably necessary to
-identify the product or service.
-
-The organization using the mark must do nothing that would, in conjunction with
-the mark, suggest sponsorship or endorsement by the trademark holder.
-
-Our trademarks must be used to refer to the Elixir programming language.
-
-Examples of permitted use
-All examples listed next must strictly adhere to the terms outlined in the
-previous sections:
-
-Usage of the Elixir logo to say a technology is “powered by Elixir” under
-nominative use. Linking back to the Elixir website, if possible, is appreciated.
-
-Usage of the Elixir logo to display it as a supported technology in a service or
-platform. For instance, you may say “we support Elixir” and use the Elixir logo,
-but you may not refer to yourself as “the Elixir platform” nor imply any form of
-endorsement or association with Elixir.
-
-Usage of the Elixir logo in non-commercial community meetups, in presentations,
-and in courses when referring to the language and its ecosystem under nominative
-use.
-
-Usage of the Elixir logo in non-commercial swag (stickers, t-shirts, mugs, etc)
-to promote the Elixir programming language. The Elixir marks must be the only
-marks featured in the product. You need permission to make swag that include
-Elixir and other third party marks in them.
-
-Inclusion of the Elixir logo in non-commercial icon sets. Use of the Elixir
-icons must still adhere to Elixir’s trademark policies.
-
-Usage of the “Elixir” word in book titles, meetups, conferences, and podcasts.
-You must not use the word to imply uniqueness or endorsement from the Elixir
-team. “The Elixir book” and “The Elixir podcast” are not permitted.
-“Elixir in Action”, “Thinking Elixir”, and “Kraków Elixir User Group” are valid
-examples already in use today.
-
-Usage of the “Elixir” word in the names of freely distributed software and
-hardware products is allowed when referring to use with or suitability for the
-Elixir programming language, such as wxElixir, Elixirsense, etc. If the product
-includes the Elixir programming language itself, then you must also respect its
-license.
-
-Examples of not permitted use
-Here is a non-exhaustive list of non permitted uses of the marks:
-
-Usage of the Elixir logo in book covers, conferences, and podcasts.
-
-Usage of the Elixir logo as the mark of third party projects, even in combination
-with other marks.
-
-Naming any company or product after Elixir, such as “The Elixir Hosting”,
-“The Elixir Consultants”, etc.
-
-Examples that require permission
-Here are some examples that may be granted permission upon request:
-
-Selling merchandise (stickers, t-shirts, mugs, etc).
-You can request permission by emailing trademarks@elixir-lang.org.
-
-Important note
-Nothing in this page shall be interpreted to allow any third party to claim any
-association with the Elixir project and the Elixir Team, or to imply any
-approval or support by the Elixir project and the Elixir Team for any third
-party products, services, or events.
@@ -1,58 +0,0 @@
-UNICODE, INC. LICENSE AGREEMENT - DATA FILES AND SOFTWARE
-
-Unicode Data Files include all data files under the directories
-http://www.unicode.org/Public/, http://www.unicode.org/reports/, and
-http://www.unicode.org/cldr/data/ . Unicode Software includes any source
-code published in the Unicode Standard or under the directories
-http://www.unicode.org/Public/, http://www.unicode.org/reports/, and
-http://www.unicode.org/cldr/data/.
-
-NOTICE TO USER: Carefully read the following legal agreement. BY
-DOWNLOADING, INSTALLING, COPYING OR OTHERWISE USING UNICODE INC.'S DATA
-FILES ("DATA FILES"), AND/OR SOFTWARE ("SOFTWARE"), YOU UNEQUIVOCALLY
-ACCEPT, AND AGREE TO BE BOUND BY, ALL OF THE TERMS AND CONDITIONS OF THIS
-AGREEMENT. IF YOU DO NOT AGREE, DO NOT DOWNLOAD, INSTALL, COPY, DISTRIBUTE
-OR USE THE DATA FILES OR SOFTWARE.
-
-COPYRIGHT AND PERMISSION NOTICE
-
-Copyright ©  Unicode, Inc. All rights reserved. Distributed under
-the Terms of Use in http://www.unicode.org/copyright.html.
-
-Permission is hereby granted, free of charge, to any person obtaining a
-copy of the Unicode data files and any associated documentation (the
-"Data Files") or Unicode software and any associated documentation (the
-"Software") to deal in the Data Files or Software without restriction,
-including without limitation the rights to use, copy, modify, merge,
-publish, distribute, and/or sell copies of the Data Files or Software,
-and to permit persons to whom the Data Files or Software are furnished
-to do so, provided that
-
-(a) the above copyright notice(s) and this permission notice appear with
-all copies of the Data Files or Software,
-
-(b) both the above copyright notice(s) and this permission notice appear
-in associated documentation, and
-
-(c) there is clear notice in each modified Data File or in the Software
-as well as in the documentation associated with the Data File(s) or
-Software that the data or software has been modified.
-
-THE DATA FILES AND SOFTWARE ARE PROVIDED "AS IS", WITHOUT WARRANTY OF
-ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
-WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
-NONINFRINGEMENT OF THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT
-HOLDER OR HOLDERS INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR
-ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER
-RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
-CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
-CONNECTION WITH THE USE OR PERFORMANCE OF THE DATA FILES OR SOFTWARE.
-
-Except as contained in this notice, the name of a copyright holder shall
-not be used in advertising or otherwise to promote the sale, use or
-other dealings in these Data Files or Software without prior written
-authorization of the copyright holder.
-
-Unicode and the Unicode logo are trademarks of Unicode, Inc., and may be
-registered in some jurisdictions. All other trademarks and registered
-trademarks mentioned herein are the property of their respective owners.
@@ -1,16 +1,11 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 PREFIX ?= /usr/local
 TEST_FILES ?= "*_test.exs"
 SHARE_PREFIX ?= $(PREFIX)/share
 MAN_PREFIX ?= $(SHARE_PREFIX)/man
-CANONICAL := main/
+# CANONICAL := main/
 ELIXIRC := bin/elixirc --ignore-module-conflict $(ELIXIRC_OPTS)
-ELIXIRC_MIN_SIG := $(ELIXIRC) -e 'Code.put_compiler_option :infer_signatures, []'
 ERLC := erlc -I lib/elixir/include
-ERL_MAKE := erl -make
+ERL_MAKE := if [ -n "$(ERLC_OPTS)" ]; then ERL_COMPILER_OPTIONS=$(ERLC_OPTS) erl -make; else erl -make; fi
 ERL := erl -I lib/elixir/include -noshell -pa lib/elixir/ebin
 GENERATE_APP := $(CURDIR)/lib/elixir/scripts/generate_app.escript
 VERSION := $(strip $(shell cat VERSION))
@@ -22,19 +17,19 @@ INSTALL_DIR = $(INSTALL) -m755 -d
 INSTALL_DATA = $(INSTALL) -m644
 INSTALL_PROGRAM = $(INSTALL) -m755
 GIT_REVISION = $(strip $(shell git rev-parse HEAD 2> /dev/null ))
-GIT_TAG = $(strip $(shell head="$(call GIT_REVISION)"; git tag --points-at $$head 2> /dev/null | grep -v latest | tail -1))
+GIT_TAG = $(strip $(shell head="$(call GIT_REVISION)"; git tag --points-at $$head 2> /dev/null | tail -1) )
 SOURCE_DATE_EPOCH_PATH = lib/elixir/tmp/ebin_reproducible
 SOURCE_DATE_EPOCH_FILE = $(SOURCE_DATE_EPOCH_PATH)/SOURCE_DATE_EPOCH

-.PHONY: cover install install_man build_plt clean_plt dialyze test check_reproducible clean clean_elixir clean_man format docs Docs.zip Precompiled.zip zips
+.PHONY: install compile erlang elixir unicode app build_plt clean_plt dialyze test check_reproducible clean clean_residual_files format install_man clean_man docs Docs.zip Precompiled.zip zips
 .NOTPARALLEL:

 #==> 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 >= 27)])' -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 >= 25)])' -s erlang halt | grep -q '^true'; \
 		if [ $$? != 0 ]; then \
-		  echo "At least Erlang/OTP 27.0 is required to build Elixir"; \
+		  echo "At least Erlang/OTP 25.0 is required to build Elixir"; \
 		  exit 1; \
 		fi
 endef
@@ -53,10 +48,6 @@ lib/$(1)/ebin/Elixir.$(2).beam: $(wildcard lib/$(1)/lib/*.ex) $(wildcard lib/$(1
 test_$(1): test_formatted $(1)
 	@ echo "==> $(1) (ex_unit)"
 	$(Q) cd lib/$(1) && ../../bin/elixir -r "test/test_helper.exs" -pr "test/**/$(TEST_FILES)";
-
-cover/ex_unit_$(1).coverdata:
-	$(Q) COVER="1" $(MAKE) test_$(1)
-cover/combined.coverdata: cover/ex_unit_$(1).coverdata
 endef

 define WRITE_SOURCE_DATE_EPOCH
@@ -74,21 +65,17 @@ endef
 #==> Compilation tasks

 APP := lib/elixir/ebin/elixir.app
-EEX := lib/eex/ebin/Elixir.EEx.beam
-ELIXIR := lib/elixir/ebin/elixir.beam
 PARSER := lib/elixir/src/elixir_parser.erl
 KERNEL := lib/elixir/ebin/Elixir.Kernel.beam
 UNICODE := lib/elixir/ebin/Elixir.String.Unicode.beam

 default: compile

-compile: erlang elixir
+compile: erlang $(APP) elixir

-erlang: $(ELIXIR)
-$(ELIXIR): $(PARSER) lib/elixir/src/*
+erlang: $(PARSER)
 	$(Q) if [ ! -f $(APP) ]; then $(call CHECK_ERLANG_RELEASE); fi
 	$(Q) cd lib/elixir && mkdir -p ebin && $(ERL_MAKE)
-	$(Q) $(GENERATE_APP) $(VERSION)

 $(PARSER): lib/elixir/src/elixir_parser.yrl
 	$(Q) erlc -o $@ +'{verbose,true}' +'{report,true}' $<
@@ -96,29 +83,29 @@ $(PARSER): lib/elixir/src/elixir_parser.yrl
 # Since Mix depends on EEx and EEx depends on Mix,
 # we first compile EEx without the .app file,
 # then Mix, and then compile EEx fully
-elixir: stdlib $(EEX) mix ex_unit logger eex iex
-stdlib: $(KERNEL) $(UNICODE) $(APP)
+elixir: stdlib lib/eex/ebin/Elixir.EEx.beam mix ex_unit logger eex iex

-$(KERNEL): lib/elixir/src/* lib/elixir/lib/*.ex lib/elixir/lib/*/*.ex lib/elixir/lib/*/*/*.ex VERSION
+stdlib: $(KERNEL) VERSION
+$(KERNEL): lib/elixir/lib/*.ex lib/elixir/lib/*/*.ex lib/elixir/lib/*/*/*.ex
 	$(Q) if [ ! -f $(KERNEL) ]; then \
 		echo "==> bootstrap (compile)"; \
 		$(ERL) -s elixir_compiler bootstrap -s erlang halt; \
-		"$(MAKE)" unicode; \
 	fi
+	$(Q) "$(MAKE)" unicode
 	@ echo "==> elixir (compile)";
-	$(Q) cd lib/elixir && ../../$(ELIXIRC_MIN_SIG) "lib/**/*.ex" -o ebin;
-	$(Q) $(GENERATE_APP) $(VERSION)
-	$(Q) bin/elixir lib/elixir/scripts/infer.exs;
+	$(Q) cd lib/elixir && ../../$(ELIXIRC) "lib/**/*.ex" -o ebin;
+	$(Q) "$(MAKE)" app

-$(APP): lib/elixir/src/elixir.app.src $(GENERATE_APP)
-	$(Q) $(GENERATE_APP) $(VERSION)
+app: $(APP)
+$(APP): lib/elixir/src/elixir.app.src lib/elixir/ebin VERSION $(GENERATE_APP)
+	$(Q) $(GENERATE_APP) $< $@ $(VERSION)

 unicode: $(UNICODE)
 $(UNICODE): lib/elixir/unicode/*
 	@ echo "==> unicode (compile)";
-	$(Q) $(ELIXIRC_MIN_SIG) lib/elixir/unicode/unicode.ex -o lib/elixir/ebin;
-	$(Q) $(ELIXIRC_MIN_SIG) lib/elixir/unicode/tokenizer.ex -o lib/elixir/ebin;
-	$(Q) $(ELIXIRC_MIN_SIG) lib/elixir/unicode/security.ex -o lib/elixir/ebin;
+	$(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/tokenizer.ex -o lib/elixir/ebin;

 $(eval $(call APP_TEMPLATE,ex_unit,ExUnit))
 $(eval $(call APP_TEMPLATE,logger,Logger))
@@ -157,7 +144,6 @@ 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/
-	$(Q) rm -rf lib/*/ebin
 	SOURCE_DATE_EPOCH=$(call READ_SOURCE_DATE_EPOCH) "$(MAKE)" compile
 	$(Q) echo "Diffing..."
 	$(Q) bin/elixir lib/elixir/scripts/diff.exs lib/elixir/ebin/ lib/elixir/tmp/ebin_reproducible/
@@ -168,10 +154,16 @@ check_reproducible: compile
 	$(Q) bin/elixir lib/elixir/scripts/diff.exs lib/mix/ebin/ lib/mix/tmp/ebin_reproducible/
 	$(Q) echo "Builds are reproducible"

-clean: clean_man
+clean:
 	rm -rf ebin
 	rm -rf lib/*/ebin
 	rm -rf $(PARSER)
+	$(Q) "$(MAKE)" clean_residual_files
+
+clean_elixir:
+	$(Q) rm -f lib/*/ebin/Elixir.*.beam
+
+clean_residual_files:
 	rm -rf lib/*/_build/
 	rm -rf lib/*/tmp/
 	rm -rf lib/elixir/test/ebin/
@@ -181,15 +173,12 @@ clean: clean_man
 	rm -rf lib/mix/test/fixtures/git_sparse_repo/
 	rm -rf lib/mix/test/fixtures/archive/ebin/
 	rm -f erl_crash.dump
-	rm -rf cover
-
-clean_elixir:
-	$(Q) rm -f lib/*/ebin/Elixir.*.beam
+	$(Q) "$(MAKE)" clean_man

 #==> Documentation tasks

 SOURCE_REF = $(shell tag="$(call GIT_TAG)" revision="$(call GIT_REVISION)"; echo "$${tag:-$$revision}")
-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)" --logo lib/elixir/pages/images/logo.png --output doc/$(2) --canonical "https://$(2).hexdocs.pm/$(CANONICAL)" --homepage-url "https://elixir-lang.org/docs.html" $(DOCS_OPTIONS) $(4)
+DOCS_COMPILE = CANONICAL=$(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 "$(call SOURCE_REF)" --logo lib/elixir/pages/images/logo.png --output doc/$(2) --canonical "https://hexdocs.pm/$(2)/$(CANONICAL)" --homepage-url "https://elixir-lang.org/docs.html" $(4)
 DOCS_CONFIG = bin/elixir lib/elixir/scripts/docs_config.exs "$(1)"

 docs: compile ../ex_doc/bin/ex_doc docs_elixir docs_eex docs_mix docs_iex docs_ex_unit docs_logger
@@ -231,19 +220,19 @@ docs_logger: compile ../ex_doc/bin/ex_doc
 	$(call DOCS_CONFIG,logger)

 ../ex_doc/bin/ex_doc:
-	@ echo "ex_doc is not found in ../ex_doc as expected. See CONTRIBUTING.md for more information."
+	@ echo "ex_doc is not found in ../ex_doc as expected. See README for more information."
 	@ false

 #==> Zip tasks

 Docs.zip: docs
 	rm -f Docs.zip
-	zip -9 -r Docs.zip CHANGELOG.md doc LICENSE README.md
+	zip -9 -r Docs.zip CHANGELOG.md doc NOTICE LICENSE README.md
 	@ echo "Docs file created $(CURDIR)/Docs.zip"

 Precompiled.zip: build_man compile
 	rm -f Precompiled.zip
-	zip -9 -r Precompiled.zip bin CHANGELOG.md lib/*/ebin lib/*/lib LICENSE Makefile man README.md VERSION
+	zip -9 -r Precompiled.zip bin CHANGELOG.md lib/*/ebin lib/*/lib LICENSE Makefile man NOTICE README.md VERSION
 	@ echo "Precompiled file created $(CURDIR)/Precompiled.zip"

 #==> Test tasks
@@ -294,15 +283,6 @@ test_stdlib: compile
 		cd lib/elixir && ../../bin/elixir --sname primary -r "test/elixir/test_helper.exs" -pr "test/elixir/**/$(TEST_FILES)"; \
 	fi

-cover/ex_unit_elixir.coverdata:
-	$(Q) COVER="1" $(MAKE) test_stdlib
-cover/combined.coverdata: cover/ex_unit_elixir.coverdata
-
-cover/combined.coverdata:
-	bin/elixir ./lib/elixir/scripts/cover.exs
-
-cover: cover/combined.coverdata
-
 #==> Dialyzer tasks

 DIALYZER_OPTS = --no_check_plt --fullpath -Werror_handling -Wunmatched_returns -Wunderspecs
@@ -325,15 +305,17 @@ dialyze: compile $(PLT)

 build_man: man/iex.1 man/elixir.1

-define BUILD_MANPAGES
-man/$(APP).1:
-	$(Q) cp man/$(APP).1.in man/$(APP).1
-	$(Q) sed -i.bak "/{COMMON}/r man/common" man/$(APP).1
-	$(Q) sed -i.bak "/{COMMON}/d" man/$(APP).1
-	$(Q) rm -f man/$(APP).1.bak
-endef
+man/iex.1:
+	$(Q) cp man/iex.1.in man/iex.1
+	$(Q) sed -i.bak "/{COMMON}/r man/common" man/iex.1
+	$(Q) sed -i.bak "/{COMMON}/d" man/iex.1
+	$(Q) rm -f man/iex.1.bak

-$(foreach APP, elixir iex, $(eval $(BUILD_MANPAGES)))
+man/elixir.1:
+	$(Q) cp man/elixir.1.in man/elixir.1
+	$(Q) sed -i.bak "/{COMMON}/r man/common" man/elixir.1
+	$(Q) sed -i.bak "/{COMMON}/d" man/elixir.1
+	$(Q) rm -f man/elixir.1.bak

 clean_man:
 	rm -f man/elixir.1
@@ -0,0 +1,37 @@
+LEGAL NOTICE INFORMATION
+------------------------
+
+All the files in this distribution are copyright to the terms below.
+
+== lib/elixir/src/elixir_parser.erl (generated by build scripts)
+
+Copyright Ericsson AB 1996-2015
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    https://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+== 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.
+You may obtain a copy of the License at
+
+   https://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
@@ -1,165 +0,0 @@
-<!--
-  SPDX-License-Identifier: Apache-2.0
-  SPDX-FileCopyrightText: 2021 The Elixir Team
-->
-
-# Open Source Policy
-
-## 1. Introduction
-
-This Open Source Policy outlines the licensing, contribution, and compliance
-requirements for all code released under the Elixir project. By adhering to
-these guidelines, we ensure that our community, maintainers, and contributors
-uphold both legal and ethical standards while fostering a collaborative,
-transparent environment.
-
-This policy exists to support and protect the Elixir community. It aims to
-balance openness, collaboration, and respect for all contributors’ rights,
-ensuring that Elixir remains a trusted and innovative open source project.
-
-## 2. Scope
-
-This policy applies to the Elixir Programming language, located at
-<https://github.com/elixir-lang/elixir>. It covers every file, and contribution
-made, including documentation and any associated assets.
-
-## 3. Licensing
-
-All code released by the Elixir team is licensed under the
-[Apache-2.0](./LICENSES/Apache-2.0.txt) license. Additionally, the following
-licenses are recognized as permissible in this project:
-
-  - The Unicode license, as documented at
-    [LicenseRef-scancode-unicode](./LICENSES/LicenseRef-scancode-unicode.txt)
-
-  - The Elixir Trademark Policy, as documented at
-    [LicenseRef-elixir-trademark-policy](./LICENSES/LicenseRef-elixir-trademark-policy.txt)
-
-These licenses are considered acceptable for any files or code that form part of
-an Elixir repository. If a contribution requires a different license, it must
-either be rejected or prompt an update to this policy.
-
-## 4. Contributing to the Elixir repository
-
-Any code contributed to the Elixir repository must fall under one of the accepted
-licenses (Apache-2.0, Unicode, or Elixir Trademark). Contributions under any
-other license will be rejected unless this policy is formally revised to include
-that license. All files except those specifically exempted (e.g., certain test
-fixture files) must contain SPDX license and copyright headers
-(`SPDX-License-Identifier` and `SPDX-FileCopyrightText`). If a file qualifies
-for an exception, this must be configured in the ORT (Open Source Review Toolkit)
-configuration and undergo review.
-
-Contributions must not introduce executable binary files into the codebase.
-
-## 5. Preservation of Copyright and License Information
-
-Any third-party code incorporated into the Elixir repository must retain original
-copyright and license headers. If no such headers exist in the source, they must
-be added. This practice ensures that original authors receive proper credit and
-that the licensing lineage is preserved.
-
-## 6. Objectives
-
-The Elixir project aims to promote a culture of responsible open source usage.
-Specifically, our objectives include:
-
-### 6.1 Clearly Define and Communicate Licensing & Compliance Policies
-
-We will identify and document all third-party dependencies, ensure that license
-information is communicated clearly, and maintain a project-wide license policy
-or compliance handbook.
-
-### 6.2 Implement Clear Processes for Reviewing Contributions
-
-We will provide well-defined contribution guidelines. We implement the
-Developer Certificate of Origin (DCO) for additional clarity regarding
-contributor rights and obligations.
-
-### 6.3 Track and Audit Third-Party Code Usage
-
-All projects will implement a Software Bill of Materials (SBoM) strategy and
-regularly verify license compliance for direct and transitive dependencies.
-
-### 6.4 Monitor and Continuously Improve Open Source Compliance
-
-We will conduct periodic internal audits, integrate compliance checks into
-continuous integration (CI/CD) pipelines, and regularly review and refine these
-objectives to align with best practices.
-
-## 7. Roles and Responsibilities
-
-### 7.1 Core Team Member
-
-Core Team Members are responsible for being familiar with this policy and
-ensuring it is consistently enforced. They must demonstrate sufficient
-competencies to understand the policy requirements and must reject or request
-changes to any pull requests that violate these standards.
-
-### 7.2 Contributor
-
-Contributors are expected to follow this policy when submitting code. If a
-contributor submits a pull request that does not comply with the policy
-(e.g., introduces a disallowed license), Core Team Members have the authority to
-reject it or request changes. No special competencies are required for
-contributors beyond awareness and adherence to the policy.
-
-### 7.3 EEF CISO
-
-The CISO designated by the Erlang Ecosystem Foundation (EEF) provides oversight
-on queries and guidance regarding open source compliance or legal matters for
-Elixir. The CISO is responsible for checking ongoing compliance with the policy,
-escalating potential violations to the Core Team, and involving legal counsel if
-necessary. This role does not require legal expertise but does involve
-initiating legal or community discussions when needed.
-
-## 8. Implications of Failing to Follow the Program Requirements
-
-If a violation of this policy is identified, the Elixir Core Team will undertake
-the following actions:
-
-## 8.1 Review the Codebase for Additional Violations
-
-We will investigate the codebase thoroughly to detect any similar instances of
-non-compliance.
-
-## 8.2 Review and Update the Process or Policy
-
-In collaboration with the EEF CISO, the Elixir Core Team will assess the policy
-and our internal workflows, making any necessary clarifications or amendments to
-reduce the likelihood of recurrence.
-
-## 8.3 Notify and Train Core Team Members
-
-We will ensure that all active Core Team Members are informed about any policy
-changes and understand how to apply them in everyday development.
-
-## 8.4 Remove or Replace the Offending Code
-
-If required, we will remove or replace the non-compliant code.
-
-## 9. Contact
-
-The project maintains a private mailing list at
-[policy@elixir-lang.org](mailto:policy@elixir-lang.org) for handling licensing
-and policy-related queries. Email is the preferred communication channel, and
-the EEF CISO will be included on this list to provide assistance and ensure
-timely responses. While solutions may take longer to implement, the project
-commits to acknowledging all queries within five business days.
-
-## 10. External Contributions of Core Team Members
-
-When Core Team Members contribute to repositories outside Elixir, they do so in
-a personal capacity or via their employer. They will not act as official
-representatives of the Elixir team in those external contexts.
-
-## 11. Policy Review and Amendments
-
-This policy will be revisited annually to address new concerns, accommodate
-changes in community standards, or adjust to emerging legal or technical
-requirements. Proposed amendments must be reviewed by the Core Team and, if
-necessary, by the EEF CISO. Any significant changes will be communicated to
-contributors and made publicly available.
-
-*Effective Date: 2025-02-20*  
-*Last Reviewed: 2025-11-20*
@@ -1,20 +1,13 @@
-<!--
-  SPDX-License-Identifier: Apache-2.0
-  SPDX-FileCopyrightText: 2021 The Elixir Team
-  SPDX-FileCopyrightText: 2012 Plataformatec
-->
-
 <h1>
 <picture>
  <source media="(prefers-color-scheme: dark)" srcset="https://github.com/elixir-lang/elixir-lang.github.com/raw/main/images/logo/logo-dark.png">
-  <img alt="Elixir logo" src="https://github.com/elixir-lang/elixir-lang.github.com/raw/main/public/images/logo/logo.png" width="200">
+  <img alt="Elixir logo" src="https://github.com/elixir-lang/elixir-lang.github.com/raw/main/images/logo/logo.png" width="200">
 </picture>
 </h1>

 [![CI](https://github.com/elixir-lang/elixir/actions/workflows/ci.yml/badge.svg?branch=main)](https://github.com/elixir-lang/elixir/actions/workflows/ci.yml?query=branch%3Amain)
-[![OpenSSF Best Practices](https://www.bestpractices.dev/projects/10187/badge)](https://www.bestpractices.dev/projects/10187)

-Elixir is a programming language designed for building scalable
+Elixir is a dynamic, functional language designed for building scalable
 and maintainable applications.

 For more about Elixir, installation and documentation,
@@ -32,18 +25,19 @@ information, please read our [Security Policy][9].
 All interactions in our official communication channels follow our
 [Code of Conduct][1].

-All contributions are required to conform to our [Open Source Policy][11].
-
 ## Bug reports

 For reporting bugs, [visit our issue tracker][2] and follow the steps
 for reporting a new issue. **Please disclose security vulnerabilities
-privately [in our Security page](https://github.com/elixir-lang/elixir/security)**.
+privately at <elixir-security@googlegroups.com>**.

-All currently open bugs related to Elixir 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.
+## 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:

@@ -55,42 +49,38 @@ Our *actionable item policy* has some important consequences, such as:
    elsewhere if appropriate).

  * We actively close unrelated and non-actionable issues to keep the
-    issues tracker tidy. If you believe we got something wrong, drop a
-    comment and we can always reopen the issue.
+    issues tracker tidy. We may get things wrong from time to
+    time and will gladly revisit issues, reopening when necessary.

-By keeping the overall issues tracker tidy and organized, the community
-can easily peek at what is coming in new releases and also get involved
-by commenting on existing issues and submitting pull requests. Please
-remember to keep the tone positive and be kind! For more information,
-see the [Code of Conduct][1].
+Keep the tone positive and be kind! For more information, see the
+[Code of Conduct][1].

-## Discussions, support, and help
+### Proposing new features
+
+For proposing new features, please start a discussion in the
+[Elixir Core mailing list][3]. The [language development history and
+its focus are described on our website](https://elixir-lang.org/development.html).
+
+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. A good proposal includes the problem description
+and how the proposed solution compares with existing alternatives
+in the Elixir ecosystem (as well as in other languages). To iron
+out a proposal before submission, consider using and gathering
+feedback from the community spaces [listed on the sidebar of the
+Elixir website](https://elixir-lang.org/).
+
+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 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.

-## Proposing new features
-
-We encourage you to first propose new features in the community spaces
-listed above. These discussions help refine ideas and gather feedback before
-submission. Our website also includes [a general outline of the language
-history and its current development focus](https://elixir-lang.org/development.html).
-
-Once you are ready, you can submit your proposal to the [Elixir Core
-mailing list][3], either through the web interface or by subscribing to
-it at <elixir-lang-core+subscribe@googlegroups.com>. Remember to include
-a clear problem description, compare the proposed solution to existing
-alternatives in the Elixir ecosystem (and in other languages if possible),
-and consider the potential impact your changes will have on the codebase and
-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]
-before release.
-
 ## Compiling from source

 For the many different ways to install Elixir,
@@ -113,19 +103,122 @@ 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).

-When updating the repository, you may want to run `make clean` before
-recompiling. For deterministic builds, you should set the environment
-variable `ERL_COMPILER_OPTIONS=deterministic`.
+Additionally, you may choose to run the test suite with `make clean test`.

 ## Contributing

-Contributions to Elixir are always welcome! Before you get started, please check
-out our [CONTRIBUTING.md](CONTRIBUTING.md) file. There you will find detailed
-guidelines on how to set up your environment, run the test suite, format your
-code, and submit pull requests.
+We invite contributions to Elixir. To contribute, there are a few
+things you need to know about the code. First, Elixir code is divided
+by each application inside the `lib` folder:

-Note you must disclose the use of coding agents and AI written code in your
-contributions. See the "Using AI and coding agents" in [CONTRIBUTING.md](CONTRIBUTING.md).
+  * `elixir` - Elixir's kernel and standard library
+
+  * `eex` - EEx is the template engine that allows you to embed Elixir
+
+  * `ex_unit` - ExUnit is a simple test framework that ships with Elixir
+
+  * `iex` - IEx stands for Interactive Elixir: Elixir's interactive shell
+
+  * `logger` - Logger is the built-in logger
+
+  * `mix` - Mix is Elixir's build tool
+
+You can run all tests in the root directory with `make test`. You can
+also run tests for a specific framework with `make test_#{APPLICATION}`, for example,
+`make test_ex_unit`. If you just changed something in Elixir's standard
+library, you can run only that portion through `make test_stdlib`.
+
+If you are only changing one file, you can choose to compile and run tests
+for that specific file for faster development cycles. For example, if you
+are changing the String module, you can compile it and run its tests as:
+
+```sh
+bin/elixirc lib/elixir/lib/string.ex -o lib/elixir/ebin
+bin/elixir lib/elixir/test/elixir/string_test.exs
+```
+
+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
+make compile
+```
+
+After your changes are done, please remember to run `make format` to guarantee
+all files are properly formatted, then run the full suite with
+`make test`.
+
+If your contribution fails during the bootstrapping of the language,
+you can rebuild the language from scratch with:
+
+```sh
+make clean_elixir compile
+```
+
+Similarly, if you can not 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).
+More tasks can be found by reading the [Makefile](Makefile).
+
+With tests running and passing, you are ready to contribute to Elixir and
+[send a pull request](https://help.github.com/articles/using-pull-requests/).
+We have saved some excellent pull requests we have received in the past in
+case you are looking for some examples:
+
+  * [Implement Enum.member? - Pull request](https://github.com/elixir-lang/elixir/pull/992)
+  * [Add String.valid? - Pull request](https://github.com/elixir-lang/elixir/pull/1058)
+  * [Implement capture_io for ExUnit - Pull request](https://github.com/elixir-lang/elixir/pull/1059)
+
+### Reviewing changes
+
+Once a pull request is sent, the Elixir team will review your changes.
+We outline our process below to clarify the roles of everyone involved.
+
+All pull requests must be approved by two committers before being merged into
+the repository. If changes are necessary, the team will leave appropriate
+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"
+feature when submitting your pull request.
+
+The Elixir team may optionally assign someone to review a pull request.
+If someone is assigned, they must explicitly approve the code before
+another team member can merge it.
+
+When the review finishes, your pull request will be squashed and merged
+into the repository. If you have carefully organized your commits and
+believe they should be merged without squashing, please mention it in
+a comment.
+
+## Building documentation
+
+Building the documentation requires that [ExDoc](https://github.com/elixir-lang/ex_doc)
+is 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/elixir ../elixir/bin/mix do deps.get + compile
+```
+
+Now go back to Elixir's root directory and run:
+
+```sh
+make docs                  # to generate HTML pages
+make docs DOCS_FORMAT=epub # to generate EPUB documents
+```
+
+This will produce documentation sets for `elixir`, `eex`, `ex_unit`, `iex`, `logger`,
+and `mix` under the `doc` directory. If you are planning to contribute documentation,
+[please check our best practices for writing documentation](https://hexdocs.pm/elixir/writing-documentation.html).

 ## Development links

@@ -148,7 +241,6 @@ contributions. See the "Using AI and coding agents" in [CONTRIBUTING.md](CONTRIB
  [8]: https://groups.google.com/group/elixir-lang-ann
  [9]: SECURITY.md
  [10]: https://groups.google.com/forum/#!searchin/elixir-lang-ann/%5Bsecurity%5D%7Csort:date
-  [11]: OPEN_SOURCE_POLICY.md

 ## License

@@ -156,4 +248,4 @@ contributions. See the "Using AI and coding agents" in [CONTRIBUTING.md](CONTRIB

 Elixir source code is released under Apache License 2.0.

-Check [LICENSE](LICENSE) file for more information.
+Check [NOTICE](NOTICE) and [LICENSE](LICENSE) files for more information.
@@ -1,34 +1,26 @@
-<!--
-  SPDX-License-Identifier: Apache-2.0
-  SPDX-FileCopyrightText: 2021 The Elixir Team
-  SPDX-FileCopyrightText: 2012 Plataformatec
-->
-
 # Release process

 ## Shipping a new version

-1. Update version in /VERSION, bin/elixir, and bin/elixir.bat
+1. Update version in /VERSION, bin/elixir and bin/elixir.bat

 2. Ensure /CHANGELOG.md is updated, versioned and add the current date

 3. Update "Compatibility and Deprecations" if a new OTP version is supported

-4. Commit changes above with title "Release vVERSION" and push it
+4. Commit changes above with title "Release vVERSION", generate a new tag, and push it

-5. Once GitHub actions completes, generate a new tag, and push it
+5. Wait until GitHub Actions publish artifacts to the draft release and the CI is green

-6. Wait until GitHub Actions publish artifacts to the draft release
+6. Copy the relevant bits from /CHANGELOG.md to the GitHub release and publish it (link to the announcement if there is one)

-7. Copy the relevant bits from /CHANGELOG.md to the GitHub release and publish it (link to the announcement if there is one)
+7. Update `_data/elixir-versions.yml` (except for RCs) in `elixir-lang/elixir-lang.github.com`

-8. Update `_data/elixir-versions.yml` (except for RCs) in `elixir-lang/elixir-lang.github.com`
-
-## Creating a new vMAJOR.MINOR branch (usually before first rc)
+## Creating a new vMAJOR.MINOR branch (before first rc)

 ### In the new branch

-1. Comment out `CANONICAL := main/` in /Makefile
+1. Comment out `CANONICAL=` in /Makefile

 2. Update tables in /SECURITY.md and "Compatibility and Deprecations"

@@ -36,7 +28,7 @@

 ### Back in main

-1. Bump /VERSION file, bin/elixir, and bin/elixir.bat
+1. Bump /VERSION file, bin/elixir and bin/elixir.bat

 2. Start new /CHANGELOG.md

@@ -50,6 +42,6 @@

 2. Update `otp_release` checks in `/Makefile` and `/lib/elixir/src/elixir.erl`

-3. Update relevant CI workflows in `/.github/workflows/*.yml` - for release workflows, outdated/recently added Erlang/OTP versions must run conditionally
+3. Update relevant CI workflows in `/.github/workflows/*.yml`

 4. Remove `otp_release` version checks that are no longer needed
@@ -1,9 +1,3 @@
-<!--
-  SPDX-License-Identifier: Apache-2.0
-  SPDX-FileCopyrightText: 2021 The Elixir Team
-  SPDX-FileCopyrightText: 2012 Plataformatec
-->
-
 # Security Policy

 ## Supported versions
@@ -12,16 +6,15 @@ Elixir applies bug fixes only to the latest minor branch. Security patches are a

 Elixir version | Support
 :------------- | :-----------------------------
-1.21           | Development
-1.20           | Bug fixes and security patches
-1.19           | Security patches only
-1.18           | Security patches only
-1.17           | Security patches only
+1.17           | Bug fixes and security patches
 1.16           | Security patches only
+1.15           | Security patches only
+1.14           | Security patches only
+1.13           | 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).
+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).

 You may also see [all releases](https://github.com/elixir-lang/elixir/releases) and [consult all disclosed vulnerabilities](https://github.com/elixir-lang/elixir/security) on GitHub.

@@ -1 +1 @@
-1.21.0-dev
+1.17.0-rc.0
@@ -1,12 +1,7 @@
 #!/bin/sh
-
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 set -e

-ELIXIR_VERSION=1.21.0-dev
+ELIXIR_VERSION=1.17.0-rc.0

 if [ $# -eq 0 ] || { [ $# -eq 1 ] && { [ "$1" = "--help" ] || [ "$1" = "-h" ]; }; }; then
  cat <<USAGE >&2
@@ -23,13 +18,13 @@ Usage: $(basename "$0") [options] [.exs file] [data]
  -pz "PATH"                   Appends the given path to Erlang code path (*)
  -v, --version                Prints Erlang/OTP and Elixir versions (standalone)

-  --color, --no-color          Enables or disables ANSI coloring
  --erl "SWITCHES"             Switches to be passed down to Erlang (*)
  --eval "COMMAND"             Evaluates the given command, same as -e (*)
  --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.
 Options can be passed to the Erlang runtime using \$ELIXIR_ERL_OPTIONS or --erl.
@@ -117,7 +112,7 @@ while [ $I -le $LENGTH ]; do
        C=1
        MODE="iex"
        ;;
-    -v|--no-halt|--color|--no-color)
+    -v|--no-halt)
        C=1
        ;;
    -e|-r|-pr|-pa|-pz|--eval|--remsh|--dot-iex|--dbg)
@@ -187,6 +182,10 @@ while [ $I -le $LENGTH ]; do
          echo "--pipe-to : LOGDIR cannot be a switch" >&2 && exit 1
        fi
        ;;
+    --werl)
+        S=1
+        if [ "$OS" = "Windows_NT" ]; then ERL_EXEC="werl"; fi
+        ;;
    *)
        while [ $I -le $LENGTH ]; do
          I=$((I + 1))
@@ -221,6 +220,10 @@ SCRIPT_PATH=$(dirname "$SELF")
 if [ "$OSTYPE" = "cygwin" ]; then SCRIPT_PATH=$(cygpath -m "$SCRIPT_PATH"); fi
 if [ "$MODE" != "iex" ]; then ERL="-s elixir start_cli $ERL"; fi

+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=
@@ -1,10 +1,6 @@
@echo off

-:: SPDX-License-Identifier: Apache-2.0
-:: SPDX-FileCopyrightText: 2021 The Elixir Team
-:: SPDX-FileCopyrightText: 2012 Plataformatec
-
-set ELIXIR_VERSION=1.21.0-dev
+set ELIXIR_VERSION=1.17.0-rc.0

 if    ""%1""==""""                if ""%2""=="""" goto documentation
 if /I ""%1""==""--help""          if ""%2""=="""" goto documentation
@@ -28,13 +24,13 @@ 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.
-echo   --color, --no-color          Enables or disables ANSI coloring
 echo   --erl "SWITCHES"             Switches to be passed down to Erlang (*)
 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.
 echo Options can be passed to the Erlang runtime using $ELIXIR_ERL_OPTIONS or --erl.
@@ -99,6 +95,7 @@ if "!par!"=="" (
 shift
 set par="!par:"=\"!"
 rem ******* EXECUTION OPTIONS **********************
+if !par!=="--werl"   (set useWerl=1 && goto startloop)
 if !par!=="+iex"     (set useIEx=1 && goto startloop)
 if !par!=="+elixirc" (goto startloop)
 rem ******* ELIXIR PARAMETERS **********************
@@ -112,8 +109,6 @@ if ""==!par:-pz=!         (shift && goto startloop)
 if ""==!par:-v=!          (goto startloop)
 if ""==!par:--version=!   (goto startloop)
 if ""==!par:--no-halt=!   (goto startloop)
-if ""==!par:--color=!     (goto startloop)
-if ""==!par:--no-color=!  (goto startloop)
 if ""==!par:--remsh=!     (shift && goto startloop)
 if ""==!par:--dot-iex=!   (shift && goto startloop)
 if ""==!par:--dbg=!       (shift && goto startloop)
@@ -133,6 +128,10 @@ if ""==!par:--pipe-to=!             (echo --pipe-to : Option is not supported on

 :run
 setlocal disabledelayedexpansion
+reg query HKCU\Console /v VirtualTerminalLevel 2>nul | findstr /e "0x1" >nul 2>nul
+if %errorlevel% == 0 (
+  set beforeExtra=-elixir ansi_enabled true %beforeExtra%
+)
 if not defined useIEx (
  set beforeExtra=-s elixir start_cli %beforeExtra%
 )
@@ -140,9 +139,17 @@ if not defined useIEx (
 set beforeExtra=-noshell -elixir_root "%SCRIPT_PATH%..\lib" -pa "%SCRIPT_PATH%..\lib\elixir\ebin" %beforeExtra%

 if defined ELIXIR_CLI_DRY_RUN (
-  echo "%ERTS_BIN%erl.exe" %ELIXIR_ERL_OPTIONS% %parsErlang% %beforeExtra% -extra %*
+   if defined useWerl (
+     echo start "" "%ERTS_BIN%werl.exe" %ext_libs% %ELIXIR_ERL_OPTIONS% %parsErlang% %beforeExtra% -extra %*
+   ) else (
+     echo "%ERTS_BIN%erl.exe" %ext_libs% %ELIXIR_ERL_OPTIONS% %parsErlang% %beforeExtra% -extra %*
+   )
 ) else (
-  "%ERTS_BIN%erl.exe" %ELIXIR_ERL_OPTIONS% %parsErlang% %beforeExtra% -extra %*
+  if defined useWerl (
+    start "" "%ERTS_BIN%werl.exe" %ext_libs% %ELIXIR_ERL_OPTIONS% %parsErlang% %beforeExtra% -extra %*
+  ) else (
+    "%ERTS_BIN%erl.exe" %ext_libs% %ELIXIR_ERL_OPTIONS% %parsErlang% %beforeExtra% -extra %*
+  )
 )
 exit /B %ERRORLEVEL%
 :end
@@ -1,9 +1,4 @@
 #!/bin/sh
-
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 set -e

 if [ $# -eq 0 ] || [ "$1" = "--help" ] || [ "$1" = "-h" ]; then
@@ -1,9 +1,4 @@
@echo off
-
-:: SPDX-License-Identifier: Apache-2.0
-:: SPDX-FileCopyrightText: 2021 The Elixir Team
-:: SPDX-FileCopyrightText: 2012 Plataformatec
-
 setlocal
 set argc=0
 for %%A in (%*) do (
@@ -1,9 +1,4 @@
 #!/bin/sh
-
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 set -e

 if [ "$1" = "--help" ] || [ "$1" = "-h" ]; then
@@ -1,9 +1,4 @@
@echo off
-
-:: SPDX-License-Identifier: Apache-2.0
-:: SPDX-FileCopyrightText: 2021 The Elixir Team
-:: SPDX-FileCopyrightText: 2012 Plataformatec
-
 setlocal
 if /I ""%1""==""--help"" goto documentation
 if /I ""%1""==""-h""     goto documentation
@@ -21,11 +16,14 @@ echo   --dot-iex "FILE"    Evaluates FILE, line by line, to set up IEx' environm
 echo                       Defaults to evaluating .iex.exs or ~/.iex.exs, if any exists.
 echo                       If FILE is 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.
+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
-call "%~dp0\elixir.bat" --no-halt --erl "-user elixir" +iex %*
+if defined IEX_WITH_WERL (set __ELIXIR_IEX_FLAGS=--werl) else (set __ELIXIR_IEX_FLAGS=)
+call "%~dp0\elixir.bat" --no-halt --erl "-user elixir" +iex %__ELIXIR_IEX_FLAGS% %*
 :end
 endlocal
@@ -1,7 +1,2 @@
 #!/usr/bin/env elixir
-
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 Mix.CLI.main()
@@ -1,7 +1,2 @@
@echo off
-
-:: SPDX-License-Identifier: Apache-2.0
-:: SPDX-FileCopyrightText: 2021 The Elixir Team
-:: SPDX-FileCopyrightText: 2012 Plataformatec
-
 call "%~dp0\elixir.bat" "%~dp0\mix" %*
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 # Store path to mix.bat as a FileInfo object
 $mixBatPath = (Get-ChildItem (((Get-ChildItem $MyInvocation.MyCommand.Path).Directory.FullName) + '\mix.bat'))
 $newArgs = @()
@@ -24,4 +20,4 @@ for ($i = 0; $i -lt $args.length; $i++)
 }

 # Corrected arguments are ready to pass to batch file
-& $mixBatPath $newArgs
+& $mixBatPath $newArgs
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule EEx.SyntaxError do
  defexception [:file, :line, :column, :snippet, message: "syntax error"]

@@ -118,19 +114,6 @@ defmodule EEx do
          | {:expr | :start_expr | :middle_expr | :end_expr, marker, charlist, metadata}
          | {:eof, metadata}

-  @type tokenize_opt ::
-          {:file, binary()}
-          | {:line, line}
-          | {:column, column}
-          | {:indentation, non_neg_integer}
-          | {:trim, boolean()}
-
-  @type compile_opt ::
-          tokenize_opt
-          | {:engine, module()}
-          | {:parser_options, Code.parser_opts()}
-          | {atom(), term()}
-
  @doc """
  Generates a function definition from the given string.

@@ -141,7 +124,6 @@ defmodule EEx do
  template.

  The supported `options` are described [in the module docs](#module-options).
-  Additional options are passed to the underlying engine.

  ## Examples

@@ -234,11 +216,9 @@ defmodule EEx do
      "3"

  """
-  @spec compile_string(String.t(), [compile_opt]) :: Macro.t()
+  @spec compile_string(String.t(), keyword) :: Macro.t()
  def compile_string(source, options \\ []) when is_binary(source) and is_list(options) do
-    tokenize_opts = Keyword.take(options, [:file, :line, :column, :indentation, :trim])
-
-    case tokenize(source, tokenize_opts) do
+    case tokenize(source, options) do
      {:ok, tokens} ->
        EEx.Compiler.compile(tokens, source, options)

@@ -275,7 +255,7 @@ defmodule EEx do
      #=> "3"

  """
-  @spec compile_file(Path.t(), [compile_opt]) :: Macro.t()
+  @spec compile_file(Path.t(), keyword) :: Macro.t()
  def compile_file(filename, options \\ []) when is_list(options) do
    filename = IO.chardata_to_string(filename)
    options = Keyword.merge([file: filename, line: 1], options)
@@ -293,7 +273,7 @@ defmodule EEx do
      "foo baz"

  """
-  @spec eval_string(String.t(), Code.binding(), [compile_opt]) :: term()
+  @spec eval_string(String.t(), keyword, keyword) :: String.t()
  def eval_string(source, bindings \\ [], options \\ [])
      when is_binary(source) and is_list(bindings) and is_list(options) do
    compiled = compile_string(source, options)
@@ -315,7 +295,7 @@ defmodule EEx do
      #=> "foo baz"

  """
-  @spec eval_file(Path.t(), Code.binding(), [compile_opt]) :: String.t()
+  @spec eval_file(Path.t(), keyword, keyword) :: String.t()
  def eval_file(filename, bindings \\ [], options \\ [])
      when is_list(bindings) and is_list(options) do
    filename = IO.chardata_to_string(filename)
@@ -344,7 +324,6 @@ defmodule EEx do

  It returns `{:ok, [token]}` where a token is one of:

-    * `{:comment, content, %{column: column, line: line}}`
    * `{:text, content, %{column: column, line: line}}`
    * `{:expr, marker, content, %{column: column, line: line}}`
    * `{:start_expr, marker, content, %{column: column, line: line}}`
@@ -356,7 +335,7 @@ defmodule EEx do
  Note new tokens may be added in the future.
  """
  @doc since: "1.14.0"
-  @spec tokenize([char()] | String.t(), [tokenize_opt]) ::
+  @spec tokenize([char()] | String.t(), opts :: keyword) ::
          {:ok, [token()]} | {:error, String.t(), metadata()}
  def tokenize(contents, opts \\ []) do
    EEx.Compiler.tokenize(contents, opts)
@@ -365,7 +344,6 @@ defmodule EEx do
  ### Helpers

  defp do_eval(compiled, bindings, options) do
-    options = Keyword.take(options, [:file, :line, :module, :prune_binding])
    {result, _} = Code.eval_quoted(compiled, bindings, options)
    result
  end
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule EEx.Compiler do
  @moduledoc false

@@ -52,14 +48,8 @@ defmodule EEx.Compiler do
    end
  end

-  # TODO: Remove me on Elixir v2.0
+  # TODO: Deprecate this on Elixir v1.18
  defp tokenize(~c"<%#" ++ t, line, column, state, buffer, acc) do
-    IO.warn("<%# is deprecated, use <%!-- or add a space between <% and # instead",
-      line: line,
-      column: column,
-      file: state.file
-    )
-
    case expr(t, line, column + 3, state, []) do
      {:error, message} ->
        {:error, message, %{line: line, column: column}}
@@ -79,7 +69,7 @@ defmodule EEx.Compiler do
        {:error, message <> code_snippet(state.source, state.indentation, meta), meta}

      {:ok, expr, new_line, new_column, rest} ->
-        {key, expr, extra_meta} =
+        {key, expr} =
          case :elixir_tokenizer.tokenize(expr, 1, file: "eex", check_terminators: false) do
            {:ok, _line, _column, _warnings, rev_tokens, []} ->
              # We ignore warnings because the code will be tokenized
@@ -87,7 +77,7 @@ defmodule EEx.Compiler do
              token_key(rev_tokens, expr)

            {:error, _, _, _, _} ->
-              {:expr, expr, %{}}
+              {:expr, expr}
          end

        marker =
@@ -96,14 +86,14 @@ defmodule EEx.Compiler do
              "unexpected beginning of EEx tag \"<%#{marker}\" on \"<%#{marker}#{expr}%>\", " <>
                "please remove \"#{marker}\""

-            IO.warn(message, file: state.file, line: line, column: column)
+            :elixir_errors.erl_warn({line, column}, state.file, message)
            ~c""
          else
            marker
          end

-        token = {key, marker, expr, Map.merge(%{line: line, column: column}, extra_meta)}
-        trim_and_tokenize(rest, new_line, new_column, state, buffer, acc, &merge_token(token, &1))
+        token = {key, marker, expr, %{line: line, column: column}}
+        trim_and_tokenize(rest, new_line, new_column, state, buffer, acc, &[token | &1])
    end
  end

@@ -127,27 +117,6 @@ defmodule EEx.Compiler do
    tokenize(rest, line, column, state, [{line, column}], fun.(acc))
  end

-  # Merge middle expressions separated only by whitespace so the whitespace is
-  # part of the Elixir expression, not a separate EEx body.
-  defp merge_token(
-         {:middle_expr, ~c"", chars, meta},
-         [{:text, text, text_meta}, {:middle_expr, ~c"", prev_chars, prev_meta} | acc]
-       ) do
-    if only_spaces?(text) and clause_block_identifier?(prev_meta) do
-      [{:middle_expr, ~c"", prev_chars ++ text ++ chars, prev_meta} | acc]
-    else
-      [
-        {:middle_expr, ~c"", chars, meta},
-        {:text, text, text_meta},
-        {:middle_expr, ~c"", prev_chars, prev_meta} | acc
-      ]
-    end
-  end
-
-  defp merge_token(token, acc) do
-    [token | acc]
-  end
-
  # Retrieve marker for <%

  defp retrieve_marker([marker | t]) when marker in [?=, ?/, ?|] do
@@ -198,37 +167,35 @@ defmodule EEx.Compiler do
  defp token_key(rev_tokens, expr) do
    case {Enum.reverse(rev_tokens), drop_eol(rev_tokens)} do
      {[{:end, _} | _], [{:do, _} | _]} ->
-        {:middle_expr, expr, %{}}
+        {:middle_expr, expr}

      {_, [{:do, _} | _]} ->
-        {:start_expr, maybe_append_space(expr), %{}}
+        {:start_expr, maybe_append_space(expr)}

-      {_, [{:block_identifier, _, identifier} | _]} ->
-        {:middle_expr, maybe_append_space(expr), %{block_identifier: identifier}}
+      {_, [{:block_identifier, _, _} | _]} ->
+        {:middle_expr, maybe_append_space(expr)}

      {[{:end, _} | _], [{:stab_op, _, _} | _]} ->
-        {:middle_expr, expr, %{}}
+        {:middle_expr, expr}

-      {_, [{:stab_op, _, _} | rev_tokens]} ->
-        if fn_before_end?(rev_tokens) do
-          {:start_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, %{}}
+          {:middle_expr, expr}
        end

      {tokens, _} ->
        case Enum.drop_while(tokens, &closing_bracket?/1) do
-          [{:end, _} | _] -> {:end_expr, expr, %{}}
-          _ -> {:expr, expr, %{}}
+          [{:end, _} | _] -> {:end_expr, expr}
+          _ -> {:expr, expr}
        end
    end
  end

-  defp fn_before_end?([{:fn, _} | _]), do: true
-  defp fn_before_end?([{:end, _} | _]), do: false
-  defp fn_before_end?([_ | rev_tokens]), do: fn_before_end?(rev_tokens)
-  defp fn_before_end?([]), do: false
-
  defp drop_eol([{:eol, _} | rest]), do: drop_eol(rest)
  defp drop_eol(rest), do: rest

@@ -326,20 +293,12 @@ defmodule EEx.Compiler do
      file: file,
      source: source,
      line: line,
-      quoted: %{},
-      parser_options: [indentation: indentation] ++ parser_options,
+      quoted: [],
+      parser_options: parser_options,
      indentation: indentation
    }

    init = state.engine.init(opts)
-
-    if function_exported?(state.engine, :handle_text, 2) and
-         not function_exported?(state.engine, :handle_text, 3) do
-      IO.warn(
-        "#{inspect(state.engine)}.handle_text/2 is deprecated, implement handle_text/3 instead"
-      )
-    end
-
    generate_buffer(tokens, init, [], state)
  end

@@ -357,7 +316,8 @@ defmodule EEx.Compiler do
        meta = [line: meta.line, column: meta.column]
        state.engine.handle_text(buffer, meta, IO.chardata_to_string(chars))
      else
-        # TODO: Remove this on Elixir v2.0. The deprecation is on init.
+        # TODO: Deprecate this branch on Elixir v1.18.
+        # We should most likely move this check to init to emit the deprecation once.
        state.engine.handle_text(buffer, IO.chardata_to_string(chars))
      end

@@ -370,7 +330,7 @@ defmodule EEx.Compiler do
        state.parser_options

    expr = Code.string_to_quoted!(chars, options)
-    buffer = handle_expr(buffer, mark, expr, meta, state)
+    buffer = state.engine.handle_expr(buffer, IO.chardata_to_string(mark), expr)
    generate_buffer(rest, buffer, scope, state)
  end

@@ -380,6 +340,13 @@ defmodule EEx.Compiler do
         scope,
         state
       ) do
+    if mark == ~c"" 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)
+    end
+
    {rest, line, contents} = look_ahead_middle(rest, meta.line, chars) || {rest, meta.line, chars}
    start_line = meta.line
    start_column = column(meta.column, mark)
@@ -389,17 +356,10 @@ defmodule EEx.Compiler do
        rest,
        state.engine.handle_begin(buffer),
        [{contents, start_line, start_column} | scope],
-        %{state | quoted: %{}, line: line}
+        %{state | quoted: [], line: line}
      )

-    if mark == ~c"" and not match?({:=, _, [_, _]}, contents) do
-      message =
-        "the contents of this expression won't be output unless the EEx block starts with \"<%=\""
-
-      IO.warn(message, file: state.file, line: meta.line, column: meta.column)
-    end
-
-    buffer = handle_expr(buffer, mark, contents, meta, state)
+    buffer = state.engine.handle_expr(buffer, IO.chardata_to_string(mark), contents)
    generate_buffer(rest, buffer, scope, state)
  end

@@ -433,7 +393,7 @@ defmodule EEx.Compiler do
       ) do
    {wrapped, state} = wrap_expr(current, meta.line, buffer, chars, state)
    options = [file: state.file, line: line, column: column] ++ state.parser_options
-    tuples = Code.string_to_quoted!(:lists.flatten(wrapped), options)
+    tuples = Code.string_to_quoted!(wrapped, options)
    buffer = insert_quoted(tuples, state.quoted)
    {buffer, rest}
  end
@@ -449,7 +409,7 @@ defmodule EEx.Compiler do

  defp generate_buffer([{:eof, _meta}], _buffer, [{content, line, column} | _scope], state) do
    message = "expected a closing '<% end %>' for block expression in EEx"
-    expr_meta = non_whitespace_meta(:lists.flatten(content), line, column, state)
+    expr_meta = non_whitespace_meta(content, line, column, state)
    syntax_error!(message, expr_meta, state)
  end

@@ -466,10 +426,10 @@ defmodule EEx.Compiler do

  defp wrap_expr(current, line, buffer, chars, state) do
    new_lines = List.duplicate(?\n, line - state.line)
-    key = map_size(state.quoted)
-    placeholder = [~c"__EEX__(", Integer.to_charlist(key), ~c");"]
-    count = [current, placeholder, new_lines, chars]
-    new_state = %{state | quoted: Map.put(state.quoted, key, state.engine.handle_end(buffer))}
+    key = length(state.quoted)
+    placeholder = ~c"__EEX__(" ++ Integer.to_charlist(key) ++ ~c");"
+    count = current ++ placeholder ++ new_lines ++ chars
+    new_state = %{state | quoted: [{key, state.engine.handle_end(buffer)} | state.quoted]}

    {count, new_state}
  end
@@ -499,16 +459,11 @@ defmodule EEx.Compiler do
    Enum.all?(chars, &(&1 in @all_spaces))
  end

-  defp clause_block_identifier?(%{block_identifier: identifier}) do
-    identifier in [:else, :rescue, :catch]
-  end
-
-  defp clause_block_identifier?(_meta), do: false
-
  # Changes placeholder to real expression

  defp insert_quoted({:__EEX__, _, [key]}, quoted) do
-    Map.fetch!(quoted, key)
+    {^key, value} = List.keyfind(quoted, key, 0)
+    value
  end

  defp insert_quoted({left, line, right}, quoted) do
@@ -541,20 +496,6 @@ defmodule EEx.Compiler do
      column: meta.column
  end

-  defp handle_expr(buffer, mark, expr, meta, state) do
-    state.engine.handle_expr(buffer, IO.chardata_to_string(mark), expr)
-  rescue
-    e in EEx.SyntaxError ->
-      reraise %{
-                e
-                | file: e.file || state.file,
-                  line: e.line || meta.line,
-                  column: e.column || meta.column,
-                  snippet: e.snippet || code_snippet(state.source, state.indentation, meta)
-              },
-              __STACKTRACE__
-  end
-
  defp code_snippet(source, indentation, meta) do
    line_start = max(meta.line - 3, 1)
    line_end = meta.line
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule EEx.Engine do
  @moduledoc ~S"""
  Basic EEx engine that ships with Elixir.
@@ -17,10 +13,6 @@ defmodule EEx.Engine do
  @doc """
  Called at the beginning of every template.

-  It receives the options during compilation, including the
-  ones managed by EEx, such as `:line` and `:file`, as well
-  as custom engine options.
-
  It must return the initial state.
  """
  @callback init(opts :: keyword) :: state
@@ -195,7 +187,7 @@ defmodule EEx.Engine do
  def handle_expr(state, "=", ast) do
    check_state!(state)
    %{binary: binary, dynamic: dynamic, vars_count: vars_count} = state
-    var = Macro.var(String.to_unsafe_atom("arg#{vars_count}"), __MODULE__)
+    var = Macro.var(:"arg#{vars_count}", __MODULE__)

    ast =
      quote do
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule EEx.SmartEngine do
  @moduledoc """
  The default engine used by EEx.
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule EEx.MixProject do
  use Mix.Project

@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 Code.require_file("../test_helper.exs", __DIR__)

 defmodule EEx.SmartEngineTest do
@@ -47,6 +43,15 @@ defmodule EEx.SmartEngineTest do
    assert_received :found
  end

+  test "error with unused \"do\" block without \"<%=\" modifier" do
+    stderr =
+      ExUnit.CaptureIO.capture_io(:stderr, fn ->
+        assert_eval("", "<% if true do %>I'm invisible!<% end %>", assigns: %{})
+      end)
+
+    assert stderr =~ "the contents of this expression won't be output"
+  end
+
  defp assert_eval(expected, actual, binding \\ []) do
    result = EEx.eval_string(actual, binding, file: __ENV__.file, engine: EEx.SmartEngine)
    assert result == expected
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 Code.require_file("../test_helper.exs", __DIR__)

 defmodule EEx.TokenizerTest do
@@ -130,21 +126,51 @@ defmodule EEx.TokenizerTest do
  end

  test "EEx comments" do
-    ExUnit.CaptureIO.capture_io(:stderr, fn ->
-      exprs = [
-        {:text, ~c"foo ", %{column: 1, line: 1}},
-        {:eof, %{column: 16, line: 1}}
-      ]
+    exprs = [
+      {:text, ~c"foo ", %{column: 1, line: 1}},
+      {:eof, %{column: 16, line: 1}}
+    ]

-      assert EEx.tokenize(~c"foo <%# true %>", @opts) == {:ok, exprs}
+    assert EEx.tokenize(~c"foo <%# true %>", @opts) == {:ok, exprs}

-      exprs = [
-        {:text, ~c"foo ", %{column: 1, line: 1}},
-        {:eof, %{column: 8, line: 2}}
-      ]
+    exprs = [
+      {:text, ~c"foo ", %{column: 1, line: 1}},
+      {:eof, %{column: 8, line: 2}}
+    ]

-      assert EEx.tokenize(~c"foo <%#\ntrue %>", @opts) == {:ok, exprs}
-    end)
+    assert EEx.tokenize(~c"foo <%#\ntrue %>", @opts) == {:ok, exprs}
+  end
+
+  test "EEx comments with do-end" do
+    exprs = [
+      {:text, ~c"foo ", %{column: 1, line: 1}},
+      {:text, ~c"bar", %{column: 19, line: 1}},
+      {:eof, %{column: 32, line: 1}}
+    ]
+
+    assert EEx.tokenize(~c"foo <%# true do %>bar<%# end %>", @opts) == {:ok, exprs}
+  end
+
+  test "EEx comments inside do-end" do
+    exprs = [
+      {:start_expr, ~c"", ~c" if true do ", %{column: 1, line: 1}},
+      {:text, ~c"bar", %{column: 31, line: 1}},
+      {:end_expr, [], ~c" end ", %{column: 34, line: 1}},
+      {:eof, %{column: 43, line: 1}}
+    ]
+
+    assert EEx.tokenize(~c"<% if true do %><%# comment %>bar<% end %>", @opts) == {:ok, exprs}
+
+    exprs = [
+      {:start_expr, [], ~c" case true do ", %{column: 1, line: 1}},
+      {:middle_expr, ~c"", ~c" true -> ", %{column: 33, line: 1}},
+      {:text, ~c"bar", %{column: 46, line: 1}},
+      {:end_expr, [], ~c" end ", %{column: 49, line: 1}},
+      {:eof, %{column: 58, line: 1}}
+    ]
+
+    assert EEx.tokenize(~c"<% case true do %><%# comment %><% true -> %>bar<% end %>", @opts) ==
+             {:ok, exprs}
  end

  test "EEx multi-line comments" do
@@ -270,7 +296,7 @@ defmodule EEx.TokenizerTest do
      {:text, ~c"foo ", %{column: 1, line: 1}},
      {:start_expr, ~c"", ~c" if true do ", %{column: 5, line: 1}},
      {:text, ~c"bar", %{column: 21, line: 1}},
-      {:middle_expr, ~c"", ~c" else ", %{block_identifier: :else, column: 24, line: 1}},
+      {:middle_expr, ~c"", ~c" else ", %{column: 24, line: 1}},
      {:text, ~c"baz", %{column: 34, line: 1}},
      {:end_expr, ~c"", ~c" end ", %{column: 37, line: 1}},
      {:eof, %{column: 46, line: 1}}
@@ -286,7 +312,7 @@ defmodule EEx.TokenizerTest do
    exprs = [
      {:start_expr, ~c"=", ~c" if true do ", %{column: 2, line: 1}},
      {:text, ~c"\n TRUE \n", %{column: 20, line: 1}},
-      {:middle_expr, ~c"", ~c" else ", %{block_identifier: :else, column: 3, line: 3}},
+      {:middle_expr, ~c"", ~c" else ", %{column: 3, line: 3}},
      {:text, ~c"\n FALSE \n", %{column: 13, line: 3}},
      {:end_expr, ~c"", ~c" end ", %{column: 3, line: 5}},
      {:eof, %{column: 3, line: 7}}
@@ -295,6 +321,15 @@ defmodule EEx.TokenizerTest do
    assert EEx.tokenize(template, [trim: true] ++ @opts) == {:ok, exprs}
  end

+  test "trim mode with comment" do
+    exprs = [
+      {:text, ~c"\n123", %{column: 19, line: 1}},
+      {:eof, %{column: 4, line: 2}}
+    ]
+
+    assert EEx.tokenize(~c"  <%# comment %>  \n123", [trim: true] ++ @opts) == {:ok, exprs}
+  end
+
  test "trim mode with multi-line comment" do
    exprs = [
      {:comment, ~c" comment ", %{column: 3, line: 1}},
@@ -349,6 +384,9 @@ defmodule EEx.TokenizerTest do
    assert EEx.tokenize(~c"foo <% :bar", @opts) ==
             {:error, message, %{column: 5, line: 1}}

+    assert EEx.tokenize(~c"<%# true ", @opts) ==
+             {:error, "expected closing '%>' for EEx expression", %{column: 1, line: 1}}
+
    message = """
    expected closing '--%>' for EEx expression
      |
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 Code.require_file("test_helper.exs", __DIR__)

 require EEx
@@ -202,6 +198,15 @@ 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 %>")

@@ -262,37 +267,6 @@ defmodule EExTest do
      assert_eval("foo 1,2,3", "foo <% require Enum, as: E %><%= E.join [1, 2, 3], \",\" %>")
    end

-    test "with expression with else clause split across tags" do
-      template = """
-      <%= with {:ok, x} <- @res do %>
-        <p><%= x %></p>
-      <% else %>
-        <% _ -> %>
-          <p>bad</p>
-      <% end %>
-      """
-
-      assert_eval("\n  <p>ok</p>\n\n", template, [assigns: [res: {:ok, "ok"}]],
-        engine: EEx.SmartEngine
-      )
-
-      assert_eval("\n    <p>bad</p>\n\n", template, [assigns: [res: :error]],
-        engine: EEx.SmartEngine
-      )
-    end
-
-    test "empty clauses separated by whitespace" do
-      template = """
-      <%= case x do %>
-        <% :foo -> %>
-        <% :bar -> %>
-      <% end %>
-      """
-
-      assert_eval("\n  \n", template, x: :foo)
-      assert_eval("\n\n", template, x: :bar)
-    end
-
    test "with end of token" do
      assert_eval("foo bar %>", "foo bar %>")
    end
@@ -533,59 +507,6 @@ defmodule EExTest do
      end
    end

-    test "from Elixir parser" do
-      line = __ENV__.line + 6
-
-      message =
-        assert_raise TokenMissingError, fn ->
-          EEx.compile_string(
-            """
-            <li>
-              <strong>Some:</strong>
-              <%= true && @some[ %>
-            </li>
-            """,
-            file: __ENV__.file,
-            line: line,
-            indentation: 12
-          )
-        end
-
-      assert message |> Exception.message() |> strip_ansi() =~ """
-                  │
-              #{line + 2} │                   true && @some[\s
-                  │                                │ └ missing closing delimiter (expected "]")
-                  │                                └ unclosed delimiter
-             """
-    end
-
-    test "from Elixir parser with line breaks" do
-      line = __ENV__.line + 6
-
-      message =
-        assert_raise TokenMissingError, fn ->
-          EEx.compile_string(
-            """
-            <li>
-              <strong>Some:</strong>
-              <%= true &&
-                @some[ %>
-            </li>
-            """,
-            file: __ENV__.file,
-            line: line,
-            indentation: 12
-          )
-        end
-
-      assert message |> Exception.message() |> strip_ansi() =~ """
-                  │
-              #{line + 3} │                 @some[\s
-                  │                      │ └ missing closing delimiter (expected "]")
-                  │                      └ unclosed delimiter
-             """
-    end
-
    test "honor line numbers" do
      assert_raise EEx.SyntaxError,
                   "nofile:100:6: expected closing '%>' for EEx expression",
@@ -606,18 +527,6 @@ defmodule EExTest do
        EEx.compile_string("foo <%= bar", file: "my_file.eex")
      end
    end
-
-    test "unsupported marker error carries template location metadata" do
-      error =
-        assert_raise EEx.SyntaxError, fn ->
-          EEx.compile_string("<%/ true %>", file: "sample.eex", line: 7)
-        end
-
-      assert error.file == "sample.eex"
-      assert error.line == 7
-      assert error.column == 1
-      assert Exception.message(error) =~ "sample.eex:7:1:"
-    end
  end

  describe "warnings" do
@@ -634,16 +543,6 @@ defmodule EExTest do
               ~s[unexpected beginning of EEx tag \"<%=\" on \"<%= end %>\"]
    end

-    test "unused \"do\" block without \"<%=\" modifier" do
-      assert ExUnit.CaptureIO.capture_io(:stderr, fn ->
-               EEx.compile_string("<% if true do %>I'm invisible!<% end %>")
-             end) =~ "the contents of this expression won't be output"
-
-      # These are fine though
-      EEx.compile_string("<% foo = fn -> %>Hello<% end %>")
-      EEx.compile_string("<% foo = if true do %>Hello<% end %>")
-    end
-
    test "from tokenizer" do
      warning =
        ExUnit.CaptureIO.capture_io(:stderr, fn ->
@@ -960,13 +859,13 @@ defmodule EExTest do
      file = to_charlist(Path.relative_to_cwd(__ENV__.file))

      assert EExTest.Compiled.before_compile() ==
-               {11, {EExTest.Compiled, :before_compile, 0, [file: file, line: 11]}}
+               {7, {EExTest.Compiled, :before_compile, 0, [file: file, line: 7]}}

      assert EExTest.Compiled.after_compile() ==
-               {25, {EExTest.Compiled, :after_compile, 0, [file: file, line: 25]}}
+               {21, {EExTest.Compiled, :after_compile, 0, [file: file, line: 21]}}

      assert EExTest.Compiled.unknown() ==
-               {30, {EExTest.Compiled, :unknown, 0, [file: ~c"unknown", line: 30]}}
+               {26, {EExTest.Compiled, :unknown, 0, [file: ~c"unknown", line: 26]}}
    end
  end

@@ -1044,12 +943,6 @@ defmodule EExTest do
    end
  end

-  @strip_ansi [IO.ANSI.green(), IO.ANSI.red(), IO.ANSI.reset()]
-
-  defp strip_ansi(doc) do
-    String.replace(doc, @strip_ansi, "")
-  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)
@@ -1,20 +1,8 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 {line_exclude, line_include} =
  if line = System.get_env("LINE"), do: {[:test], [line: line]}, else: {[], []}

-Code.require_file("../../elixir/scripts/cover_record.exs", __DIR__)
-CoverageRecorder.maybe_record("eex")
-
-maybe_seed_opt = if seed = System.get_env("SEED"), do: [seed: String.to_integer(seed)], else: []
-
-ex_unit_opts =
-  [
-    trace: !!System.get_env("TRACE"),
-    include: line_include,
-    exclude: line_exclude
-  ] ++ maybe_seed_opt
-
-ExUnit.start(ex_unit_opts)
+ExUnit.start(
+  trace: !!System.get_env("TRACE"),
+  include: line_include,
+  exclude: line_exclude
+)
@@ -1,7 +1,3 @@
-%% SPDX-License-Identifier: Apache-2.0
-%% SPDX-FileCopyrightText: 2021 The Elixir Team
-%% SPDX-FileCopyrightText: 2012 Plataformatec
-
 {'src/*', [
  warn_unused_vars,
  warn_export_all,
@@ -13,8 +9,8 @@
  warn_deprecated_function,
  warn_obsolete_guard,
  warn_exported_vars,
-  %% Enable this when we require Erlang/OTP 27+
-  %% warnings_as_errors,
+  %% warn_missing_spec,
+  %% warn_untyped_record,
  debug_info,
  {outdir, "ebin/"}
 ]}.
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule Access do
  @moduledoc """
  Key-based access to data structures.
@@ -10,8 +6,8 @@ defmodule Access do
  keys of any type in a data structure via the `data[key]` syntax.

  `Access` supports keyword lists (`Keyword`) and maps (`Map`) out
-  of the box. Keyword lists support only atom keys, while keys for maps
-  can be of any type. Both return `nil` if the key does not exist:
+  of the box. Keywords supports only atoms keys, keys for maps can
+  be of any type. Both return `nil` if the key does not exist:

      iex> keywords = [a: 1, b: 2]
      iex> keywords[:a]
@@ -33,7 +29,7 @@ defmodule Access do
      iex> keywords[:c][:unknown]
      nil

-  This works because accessing anything on a `nil` value returns
+  This works because accessing anything on a `nil` value, returns
  `nil` itself:

      iex> nil[:a]
@@ -226,8 +222,6 @@ defmodule Access do
    end
  end

-  defguardp is_probably_keyword(list) when list == [] or is_atom(elem(hd(list), 0))
-
  @doc """
  Fetches the value for the given key in a container (a map, keyword
  list, or struct that implements the `Access` behaviour).
@@ -356,7 +350,7 @@ defmodule Access do
    Accessing a list by index is typically discouraged in Elixir, \
    instead we prefer to use the Enum module to manipulate lists \
    as a whole. If you really must access a list element by index, \
-    you can use Enum.at/2 or the functions in the List module\
+    you can Enum.at/1 or the functions in the List module\
    """
  end

@@ -424,8 +418,8 @@ defmodule Access do

    Accessing a list by index is typically discouraged in Elixir, \
    instead we prefer to use the Enum module to manipulate lists \
-    as a whole. If you really must modify a list element by index, \
-    you can use Access.at/1 or the functions in the List module\
+    as a whole. If you really must mostify a list element by index, \
+    you can Access.at/1 or the functions in the List module\
    """
  end

@@ -487,7 +481,7 @@ defmodule Access do
  ## Accessors

  @doc """
-  Returns a function that accesses the given key in a map/struct/keyword list.
+  Returns a function that accesses the given key in a map/struct.

  The returned function is typically passed as an accessor to `Kernel.get_in/2`,
  `Kernel.get_and_update_in/3`, and friends.
@@ -516,56 +510,30 @@ defmodule Access do
      iex> pop_in(map, [Access.key(:user), Access.key(:name)])
      {"john", %{user: %{}}}

-      iex> keyword = [user: [name: "john"]]
-      iex> get_in(keyword, [Access.key(:unknown, []), Access.key(:name, "john")])
-      "john"
-      iex> get_and_update_in(keyword, [Access.key(:user), Access.key(:name)], fn prev ->
-      ...>   {prev, String.upcase(prev)}
-      ...> end)
-      {"john", [user: [name: "JOHN"]]}
-      iex> pop_in(keyword, [Access.key(:user), Access.key(:name)])
-      {"john", [user: []]}
+  An error is raised if the accessed structure is not a map or a struct:

-  An error is raised if the accessed structure is not a map, struct, or keyword list:
+      iex> get_in([], [Access.key(:foo)])
+      ** (BadMapError) expected a map, got: []

-      iex> get_in(123, [Access.key(:foo)])
-      ** (RuntimeError) Access.key/2 expected a map/struct/keyword list, got: ...
-
-      iex> put_in([1, 2, 3], [Access.key(:foo)], :bar)
-      ** (RuntimeError) Access.key/2 expected a map/struct/keyword list, got: ...
  """
-  @spec key(key, term) :: access_fun(data :: struct | map | keyword, current_value :: term)
+  @spec key(key, term) :: access_fun(data :: struct | map, current_value :: term)
  def key(key, default \\ nil) do
    fn
-      :get, %{} = data, next ->
+      :get, data, next ->
        next.(Map.get(data, key, default))

-      :get_and_update, %{} = data, next ->
+      :get_and_update, data, next ->
        value = Map.get(data, key, default)

        case next.(value) do
          {get, update} -> {get, Map.put(data, key, update)}
          :pop -> {value, Map.delete(data, key)}
        end
-
-      :get, data, next when is_probably_keyword(data) ->
-        next.(Keyword.get(data, key, default))
-
-      :get_and_update, data, next when is_probably_keyword(data) ->
-        value = Keyword.get(data, key, default)
-
-        case next.(value) do
-          {get, update} -> {get, Keyword.put(data, key, update)}
-          :pop -> {value, Keyword.delete(data, key)}
-        end
-
-      _op, data, _next ->
-        raise "Access.key/2 expected a map/struct/keyword list, got: #{inspect(data)}"
    end
  end

  @doc """
-  Returns a function that accesses the given key in a map/struct/keyword list.
+  Returns a function that accesses the given key in a map/struct.

  The returned function is typically passed as an accessor to `Kernel.get_in/2`,
  `Kernel.get_and_update_in/3`, and friends.
@@ -574,19 +542,6 @@ defmodule Access do

  ## Examples

-      iex> keyword = [user: [name: "john"]]
-      iex> get_in(keyword, [Access.key!(:user), Access.key!(:name)])
-      "john"
-      iex> get_and_update_in(keyword, [Access.key!(:user), Access.key!(:name)], fn prev ->
-      ...>   {prev, String.upcase(prev)}
-      ...> end)
-      {"john", [user: [name: "JOHN"]]}
-      iex> pop_in(keyword, [Access.key!(:user), Access.key!(:name)])
-      {"john", [user: []]}
-      iex> get_in(keyword, [Access.key!(:user), Access.key!(:unknown)])
-      ** (KeyError) key :unknown not found in:
-      ...
-
      iex> map = %{user: %{name: "john"}}
      iex> get_in(map, [Access.key!(:user), Access.key!(:name)])
      "john"
@@ -597,8 +552,7 @@ defmodule Access do
      iex> pop_in(map, [Access.key!(:user), Access.key!(:name)])
      {"john", %{user: %{}}}
      iex> get_in(map, [Access.key!(:user), Access.key!(:unknown)])
-      ** (KeyError) key :unknown not found in:
-      ...
+      ** (KeyError) key :unknown not found in: %{name: \"john\"}

  The examples above could be partially written as:

@@ -615,15 +569,13 @@ defmodule Access do
  `Access.key!/1` is useful when the key is not known in advance
  and must be accessed dynamically.

-  An error is raised if the accessed structure is not a map/struct/keyword list:
+  An error is raised if the accessed structure is not a map/struct:

-      iex> get_in(123, [Access.key!(:foo)])
-      ** (RuntimeError) Access.key!/1 expected a map/struct/keyword list, got: 123
+      iex> get_in([], [Access.key!(:foo)])
+      ** (RuntimeError) Access.key!/1 expected a map/struct, got: []

-      iex> put_in([1, 2, 3], [Access.key!(:foo)], :bar)
-      ** (RuntimeError) Access.key!/1 expected a map/struct/keyword list, got: ...
  """
-  @spec key!(key) :: access_fun(data :: struct | map | keyword, current_value :: term)
+  @spec key!(key) :: access_fun(data :: struct | map, current_value :: term)
  def key!(key) do
    fn
      :get, %{} = data, next ->
@@ -637,19 +589,8 @@ defmodule Access do
          :pop -> {value, Map.delete(data, key)}
        end

-      :get, data, next when is_probably_keyword(data) ->
-        next.(Keyword.fetch!(data, key))
-
-      :get_and_update, data, next when is_probably_keyword(data) ->
-        value = Keyword.fetch!(data, key)
-
-        case next.(value) do
-          {get, update} -> {get, Keyword.put(data, key, update)}
-          :pop -> {value, Keyword.delete(data, key)}
-        end
-
      _op, data, _next ->
-        raise "Access.key!/1 expected a map/struct/keyword list, got: #{inspect(data)}"
+        raise "Access.key!/1 expected a map/struct, got: #{inspect(data)}"
    end
  end

@@ -866,7 +807,7 @@ defmodule Access do
      iex> get_in([:a, :b, :c], [Access.at!(2)])
      :c
      iex> get_in([:a, :b, :c], [Access.at!(3)])
-      ** (Enum.OutOfBoundsError) out of bounds error at position 3 when traversing enumerable [:a, :b, :c]
+      ** (Enum.OutOfBoundsError) out of bounds error

  """
  @doc since: "1.11.0"
@@ -878,14 +819,12 @@ defmodule Access do
  defp at!(:get, data, index, next) when is_list(data) do
    case Enum.fetch(data, index) do
      {:ok, value} -> next.(value)
-      :error -> raise Enum.OutOfBoundsError, index: index, enumerable: data
+      :error -> raise Enum.OutOfBoundsError
    end
  end

  defp at!(:get_and_update, data, index, next) when is_list(data) do
-    get_and_update_at(data, index, next, [], fn ->
-      raise Enum.OutOfBoundsError, index: index, enumerable: data
-    end)
+    get_and_update_at(data, index, next, [], fn -> raise Enum.OutOfBoundsError end)
  end

  defp at!(_op, data, _index, _next) do
@@ -917,7 +856,7 @@ defmodule Access do
      iex> pop_in(list, [Access.filter(&(&1.salary >= 20)), :name])
      {["francine"], [%{name: "john", salary: 10}, %{salary: 30}]}

-  When no match is found, an empty list is returned and the update function is never called:
+  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}]
      iex> get_in(list, [Access.filter(&(&1.salary >= 50)), :name])
@@ -927,6 +866,11 @@ defmodule Access do
      ...> end)
      {[], [%{name: "john", salary: 10}, %{name: "francine", salary: 30}]}

+  An error is raised if the predicate is not a function or is of the incorrect arity:
+
+      iex> get_in([], [Access.filter(5)])
+      ** (FunctionClauseError) no function clause matching in Access.filter/1
+
  An error is raised if the accessed structure is not a list:

      iex> get_in(%{}, [Access.filter(fn a -> a == 10 end)])
@@ -934,13 +878,13 @@ defmodule Access do

  """
  @doc since: "1.6.0"
-  @spec filter((term -> as_boolean(term))) :: access_fun(data :: list, current_value :: list)
+  @spec filter((term -> boolean)) :: access_fun(data :: list, current_value :: list)
  def filter(func) when is_function(func) do
    fn op, data, next -> filter(op, data, func, next) end
  end

  defp filter(:get, data, func, next) when is_list(data) do
-    for elem <- data, func.(elem), do: next.(elem)
+    data |> Enum.filter(func) |> Enum.map(next)
  end

  defp filter(:get_and_update, data, func, next) when is_list(data) do
@@ -1035,12 +979,12 @@ defmodule Access do
  end

  defp slice(:get_and_update, data, range, next) when is_list(data) do
-    %Range{first: first, last: last, step: step} = normalize_range(range, data)
+    range = normalize_range(range, data)

-    if first > last do
+    if range.first > range.last do
      {[], data}
    else
-      get_and_update_slice(data, first, last, step, next, [], [], 0)
+      get_and_update_slice(data, range, next, [], [], 0)
    end
  end

@@ -1048,93 +992,6 @@ defmodule Access do
    raise ArgumentError, "Access.slice/1 expected a list, got: #{inspect(data)}"
  end

-  @doc """
-  Returns a function that accesses all values in a map or a keyword list.
-
-  The returned function is typically passed as an accessor to `Kernel.get_in/2`,
-  `Kernel.get_and_update_in/3`, and friends.
-
-  ## Examples
-
-      iex> users = %{"john" => %{age: 27}, "meg" => %{age: 23}}
-      iex> get_in(users, [Access.values(), :age]) |> Enum.sort()
-      [23, 27]
-      iex> update_in(users, [Access.values(), :age], fn age -> age + 1 end)
-      %{"john" => %{age: 28}, "meg" => %{age: 24}}
-      iex> put_in(users, [Access.values(), :planet], "Earth")
-      %{"john" => %{age: 27, planet: "Earth"}, "meg" => %{age: 23, planet: "Earth"}}
-
-  Values in keyword lists can be accessed as well:
-
-      iex> users = [john: %{age: 27}, meg: %{age: 23}]
-      iex> get_and_update_in(users, [Access.values(), :age], fn age -> {age, age + 1} end)
-      {[27, 23], [john: %{age: 28}, meg: %{age: 24}]}
-
-  By returning `:pop` from an accessor function, you can remove the accessed key and value
-  from the map or keyword list:
-
-      iex> require Integer
-      iex> numbers = [one: 1, two: 2, three: 3, four: 4]
-      iex> get_and_update_in(numbers, [Access.values()], fn num ->
-      ...>   if Integer.is_even(num), do: :pop, else: {num, to_string(num)}
-      ...> end)
-      {[1, 2, 3, 4], [one: "1", three: "3"]}
-
-  An error is raised if the accessed structure is not a map nor a keyword list:
-
-      iex> get_in([1, 2, 3], [Access.values()])
-      ** (RuntimeError) Access.values/0 expected a map or a keyword list, got: [1, 2, 3]
-  """
-  @doc since: "1.19.0"
-  @spec values() :: Access.access_fun(data :: map() | keyword(), current_value :: list())
-  def values do
-    &values/3
-  end
-
-  defp values(:get, data = %{}, next) do
-    Enum.map(data, fn {_key, value} -> next.(value) end)
-  end
-
-  defp values(:get_and_update, data = %{}, next) do
-    {reverse_gets, updated_data} =
-      Enum.reduce(data, {[], %{}}, fn {key, value}, {gets, data_acc} ->
-        case next.(value) do
-          {get, update} -> {[get | gets], Map.put(data_acc, key, update)}
-          :pop -> {[value | gets], data_acc}
-        end
-      end)
-
-    {Enum.reverse(reverse_gets), updated_data}
-  end
-
-  defp values(op, data = [], next) do
-    values_keyword(op, data, next)
-  end
-
-  defp values(op, data = [{key, _value} | _tail], next) when is_atom(key) do
-    values_keyword(op, data, next)
-  end
-
-  defp values(_op, data, _next) do
-    raise "Access.values/0 expected a map or a keyword list, got: #{inspect(data)}"
-  end
-
-  defp values_keyword(:get, data, next) do
-    Enum.map(data, fn {key, value} when is_atom(key) -> next.(value) end)
-  end
-
-  defp values_keyword(:get_and_update, data, next) do
-    {reverse_gets, reverse_updated_data} =
-      Enum.reduce(data, {[], []}, fn {key, value}, {gets, data_acc} when is_atom(key) ->
-        case next.(value) do
-          {get, update} -> {[get | gets], [{key, update} | data_acc]}
-          :pop -> {[value | gets], data_acc}
-        end
-      end)
-
-    {Enum.reverse(reverse_gets), Enum.reverse(reverse_updated_data)}
-  end
-
  defp normalize_range(%Range{first: first, last: last, step: step}, list)
       when first < 0 or last < 0 do
    count = length(list)
@@ -1145,23 +1002,16 @@ defmodule Access do

  defp normalize_range(range, _list), do: range

-  defp get_and_update_slice(rest, _first, last, _step, _next, updates, gets, index)
-       when index > last do
-    {:lists.reverse(gets), :lists.reverse(updates, rest)}
-  end
-
-  defp get_and_update_slice([head | rest], first, last, step, next, updates, gets, index) do
-    if index >= first and rem(index - first, step) == 0 do
+  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, first, last, step, next, updates, [head | gets], index + 1)
+          get_and_update_slice(rest, range, next, updates, [head | gets], index + 1)

        {get, update} ->
          get_and_update_slice(
            rest,
-            first,
-            last,
-            step,
+            range,
            next,
            [update | updates],
            [get | gets],
@@ -1169,11 +1019,11 @@ defmodule Access do
          )
      end
    else
-      get_and_update_slice(rest, first, last, step, next, [head | updates], gets, index + 1)
+      get_and_update_slice(rest, range, next, [head | updates], gets, index + 1)
    end
  end

-  defp get_and_update_slice([], _first, _last, _step, _next, updates, gets, _index) do
+  defp get_and_update_slice([], _range, _next, updates, gets, _index) do
    {:lists.reverse(gets), :lists.reverse(updates)}
  end

@@ -1188,9 +1038,9 @@ defmodule Access do
      iex> list = [%{name: "john", salary: 10}, %{name: "francine", salary: 30}]
      iex> get_in(list, [Access.find(&(&1.salary > 20)), :name])
      "francine"
-      iex> get_and_update_in(list, [Access.find(&(&1.salary <= 40)), :name], fn prev ->
-      ...>   {prev, String.upcase(prev)}
-      ...> end)
+      iex>  get_and_update_in(list, [Access.find(&(&1.salary <= 40)), :name], fn prev ->
+      ...> {prev, String.upcase(prev)}
+      ...>  end)
      {"john", [%{name: "JOHN", salary: 10}, %{name: "francine", salary: 30}]}

  `find/1` can also be used to pop the first found element out of a list or
@@ -1200,7 +1050,7 @@ defmodule Access do
      iex> pop_in(list, [Access.find(&(&1.salary <= 40))])
      {%{name: "john", salary: 10}, [%{name: "francine", salary: 30}]}

-  When no match is found, nil is returned and the update function is never called:
+  When no match is found, nil is returned and the update function is never called

      iex> list = [%{name: "john", salary: 10}, %{name: "francine", salary: 30}]
      iex> get_in(list, [Access.find(&(&1.salary >= 50)), :name])
@@ -1210,9 +1060,14 @@ defmodule Access do
      ...> end)
      {nil, [%{name: "john", salary: 10}, %{name: "francine", salary: 30}]}

+  An error is raised if the predicate is not a function or is of the incorrect arity:
+
+      iex> get_in([], [Access.find(5)])
+      ** (FunctionClauseError) no function clause matching in Access.find/1
+
  An error is raised if the accessed structure is not a list:

-      iex> get_in(%{}, [Access.find(fn a -> a == 10 end)])
+      iex>  get_in(%{}, [Access.find(fn a -> a == 10 end)])
      ** (RuntimeError) Access.find/1 expected a list, got: %{}
  """
  @doc since: "1.17.0"
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule Agent do
  @moduledoc """
  Agents are a simple abstraction around state.
@@ -211,7 +207,7 @@ defmodule Agent do
  @doc false
  defmacro __using__(opts) do
    quote location: :keep, bind_quoted: [opts: opts] do
-      if not Module.has_attribute?(__MODULE__, :doc) do
+      unless Module.has_attribute?(__MODULE__, :doc) do
        @doc """
        Returns a specification to start this module under a supervisor.

@@ -288,7 +284,7 @@ defmodule Agent do
  instead of an anonymous function; `fun` in `module` will be called with the
  given arguments `args` to initialize the state.
  """
-  @spec start_link(module, atom, [term], GenServer.options()) :: on_start
+  @spec start_link(module, atom, [any], GenServer.options()) :: on_start
  def start_link(module, fun, args, options \\ []) do
    GenServer.start_link(Agent.Server, {module, fun, args}, options)
  end
@@ -315,7 +311,7 @@ defmodule Agent do

  See `start_link/4` for more information.
  """
-  @spec start(module, atom, [term], GenServer.options()) :: on_start
+  @spec start(module, atom, [any], GenServer.options()) :: on_start
  def start(module, fun, args, options \\ []) do
    GenServer.start(Agent.Server, {module, fun, args}, options)
  end
@@ -327,7 +323,7 @@ defmodule Agent do
  passing the agent state. The result of the function invocation is
  returned from this function.

-  `timeout` is a non-negative integer which specifies how many
+  `timeout` is an integer greater than zero which specifies how many
  milliseconds are allowed before the agent executes the function and returns
  the result value, or the atom `:infinity` to wait indefinitely. If no result
  is received within the specified time, the function call fails and the caller
@@ -352,7 +348,7 @@ defmodule Agent do
  instead of an anonymous function. The state is added as first
  argument to the given list of arguments.
  """
-  @spec get(agent, module, atom, [term], timeout) :: term
+  @spec get(agent, module, atom, [term], timeout) :: any
  def get(agent, module, fun, args, timeout \\ 5000) do
    GenServer.call(agent, {:get, {module, fun, args}}, timeout)
  end
@@ -366,7 +362,7 @@ defmodule Agent do
  elements, the first being the value to return (that is, the "get" value)
  and the second one being the new state of the agent.

-  `timeout` is a non-negative integer which specifies how many
+  `timeout` is an integer greater than zero which specifies how many
  milliseconds are allowed before the agent executes the function and returns
  the result value, or the atom `:infinity` to wait indefinitely. If no result
  is received within the specified time, the function call fails and the caller
@@ -393,7 +389,7 @@ defmodule Agent do
  instead of an anonymous function. The state is added as first
  argument to the given list of arguments.
  """
-  @spec get_and_update(agent, module, atom, [term], timeout) :: term
+  @spec get_and_update(agent, module, atom, [term], timeout) :: any
  def get_and_update(agent, module, fun, args, timeout \\ 5000) do
    GenServer.call(agent, {:get_and_update, {module, fun, args}}, timeout)
  end
@@ -407,7 +403,7 @@ defmodule Agent do

  This function always returns `:ok`.

-  `timeout` is a non-negative integer which specifies how many
+  `timeout` is an integer greater than zero which specifies how many
  milliseconds are allowed before the agent executes the function and returns
  the result value, or the atom `:infinity` to wait indefinitely. If no result
  is received within the specified time, the function call fails and the caller
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule Agent.Server do
  @moduledoc false

@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule Application do
  @moduledoc """
  A module for working with applications and defining application callbacks.
@@ -58,12 +54,12 @@ defmodule Application do
  You can also change the application environment dynamically by using functions
  such as `put_env/3` and `delete_env/2`.

-  > #### Application environment in libraries {: .info}
+  > #### Environment in libraries {: .tip}
  >
-  > 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 about this [anti-pattern](design-anti-patterns.md#using-application-configuration-for-libraries).
+  > The config files `config/config.exs` and `config/runtime.exs`
+  > are rarely used by libraries. Libraries typically define their environment
+  > in the `application/0` function of their `mix.exs`. Configuration files
+  > are rather used by applications to configure their libraries.

  > #### Reading the environment of other applications {: .warning}
  >
@@ -247,7 +243,7 @@ defmodule Application do
  invoked if it hasn't been done yet. Then, it checks if the dependencies listed
  in the `applications` key of the resource file are already started. Having at
  least one dependency not started is an error condition. Functions like
-  `ensure_all_started/1` take care of starting an application and all of its
+  `ensure_all_started/1` takes care of starting an application and all of its
  dependencies for you.

  If the application does not have a callback module configured, starting is
@@ -507,7 +503,7 @@ defmodule Application do
  of all loaded applications. Returns `nil` if
  the module is not listed in any application spec.
  """
-  @spec get_application(module) :: app | nil
+  @spec get_application(atom) :: atom | nil
  def get_application(module) when is_atom(module) do
    case :application.get_application(module) do
      {:ok, app} -> app
@@ -677,16 +673,23 @@ defmodule Application do
  > You must use this function to read only your own application
  > environment. Do not read the environment of other applications.

+  > #### Application environment in libraries {: .info}
+  >
+  > 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

  `get_env/3` is commonly used to read the configuration of your OTP applications.
-  Since Mix configurations are commonly used to configure applications (including
-  your dependencies), we will use this as a point of illustration.
+  Since Mix configurations are commonly used to configure applications, we will use
+  this as a point of illustration.

  Consider a new application `:my_app`. `:my_app` contains a database engine which
  supports a pool of databases. The database engine needs to know the configuration for
  each of those databases, and that configuration is supplied by key-value pairs in
-  environment of `:my_app`. For example, your `config/runtime.exs` file might have:
+  environment of `:my_app`.

      config :my_app, Databases.RepoOne,
        # A database configuration
@@ -696,7 +699,7 @@ defmodule Application do
      config :my_app, Databases.RepoTwo,
        # Another database configuration (for the same OTP app)
        ip: "localhost",
-        port: 20_717
+        port: 20717

      config :my_app, my_app_databases: [Databases.RepoOne, Databases.RepoTwo]

@@ -714,11 +717,6 @@ defmodule Application do
      config = Application.get_env(:my_app, Databases.RepoOne)
      config[:ip]

-  The sample `config/runtime.exs` above could be used both for `:my_app` to
-  configure itself but also to allow any application that depends on `:my_app`
-  to configure how it works. However, one should keep in mind the caveats described
-  in the `Application` module documentation: the application environment is global
-  state which should be avoided if possible.
  """
  @spec get_env(app, key, value) :: value
  def get_env(app, key, default \\ nil) when is_atom(app) do
@@ -798,12 +796,6 @@ defmodule Application do
  @doc """
  Puts the `value` in `key` for the given `app`.

-  > #### Compile environment {: .warning}
-  >
-  > Do not use this function to change environment variables read
-  > via `Application.compile_env/2`. The compile environment must
-  > be exclusively set before compilation, in your config files.
-
  ## Options

    * `:timeout` - the timeout for the change (defaults to `5_000` milliseconds)
@@ -819,7 +811,7 @@ defmodule Application do
  stick after the application is loaded and also on application reload.
  """
  @spec put_env(app, key, value, timeout: timeout, persistent: boolean) :: :ok
-  def put_env(app, key, value, opts \\ []) when is_atom(app) and is_list(opts) do
+  def put_env(app, key, value, opts \\ []) when is_atom(app) do
    maybe_warn_on_app_env_key(app, key)
    :application.set_env(app, key, value, opts)
  end
@@ -861,7 +853,7 @@ defmodule Application do
  It receives the same options as `put_env/4`. Returns `:ok`.
  """
  @spec delete_env(app, key, timeout: timeout, persistent: boolean) :: :ok
-  def delete_env(app, key, opts \\ []) when is_atom(app) and is_list(opts) do
+  def delete_env(app, key, opts \\ []) when is_atom(app) do
    maybe_warn_on_app_env_key(app, key)
    :application.unset_env(app, key, opts)
  end
@@ -908,16 +900,17 @@ defmodule Application do
  @doc """
  Ensures the given `app` or `apps` and their child applications are started.

-  The second argument is either the `t:restart_type/0` (for consistency with
+  The second argument is either the `t:restart_type/1` (for consistency with
  `start/2`) or a keyword list.

  ## Options

    * `:type` - if the application should be started `:temporary` (default),
-      `:permanent`, or `:transient`. See `t:restart_type/0` for more information.
+      `:permanent`, or `:transient`. See `t:restart_type/1` for more information.

    * `:mode` - (since v1.15.0) if the applications should be started serially
-      (`:serial`, default) or concurrently (`:concurrent`).
+      (`:serial`, default) or concurrently (`:concurrent`). This option requires
+      Erlang/OTP 26+.

  """
  @spec ensure_all_started(app | [app], type: restart_type(), mode: :serial | :concurrent) ::
@@ -926,11 +919,11 @@ defmodule Application do
          {:ok, [app]} | {:error, term}
  def ensure_all_started(app_or_apps, type_or_opts \\ [])

-  def ensure_all_started(app_or_apps, type) when is_atom(type) do
-    ensure_all_started(app_or_apps, type: type)
+  def ensure_all_started(app, type) when is_atom(type) do
+    ensure_all_started(app, type: type)
  end

-  def ensure_all_started(app, opts) when is_atom(app) and is_list(opts) do
+  def ensure_all_started(app, opts) when is_atom(app) do
    ensure_all_started([app], opts)
  end

@@ -938,7 +931,18 @@ defmodule Application do

  def ensure_all_started(apps, opts) when is_list(apps) and is_list(opts) do
    opts = Keyword.validate!(opts, type: :temporary, mode: :serial)
-    :application.ensure_all_started(apps, opts[:type], opts[:mode])
+
+    if function_exported?(:application, :ensure_all_started, 3) do
+      :application.ensure_all_started(apps, opts[:type], opts[:mode])
+    else
+      # TODO: Remove this clause when we require Erlang/OTP 26+
+      Enum.reduce_while(apps, {:ok, []}, fn app, {:ok, acc} ->
+        case :application.ensure_all_started(app, opts[:type]) do
+          {:ok, apps} -> {:cont, {:ok, apps ++ acc}}
+          {:error, e} -> {:halt, {:error, e}}
+        end
+      end)
+    end
  end

  @doc """
@@ -996,7 +1000,7 @@ defmodule Application do
  end

  @doc """
-  Gets the directory for `app`.
+  Gets the directory for app.

  This information is returned based on the code path. Here is an
  example:
@@ -1061,8 +1065,7 @@ defmodule Application do
  Returns a list with information about the applications which are currently running.
  """
  @spec started_applications(timeout) :: [{app, description :: charlist(), vsn :: charlist()}]
-  def started_applications(timeout \\ 5000)
-      when timeout == :infinity or (is_integer(timeout) and timeout >= 0) do
+  def started_applications(timeout \\ 5000) do
    :application.which_applications(timeout)
  end

@@ -1077,7 +1080,7 @@ defmodule Application do
  @doc """
  Formats the error reason returned by `start/2`,
  `ensure_started/2`, `stop/1`, `load/1` and `unload/1`,
-  and returns a string.
+  returns a string.
  """
  @spec format_error(any) :: String.t()
  def format_error(reason) do
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule Atom do
  @moduledoc """
  Atoms are constants whose values are their own name.
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule Behaviour do
  @moduledoc """
  Mechanism for handling behaviours.
@@ -13,8 +9,7 @@ defmodule Behaviour do
  attributes.

  Instead of `MyModule.__behaviour__(:callbacks)`,
-  `MyModule.behaviour_info(:callbacks)` can be used. `behaviour_info/1`
-  is documented in `Module`.
+  `MyModule.behaviour_info(:callbacks)` can be used.
  """

  @moduledoc deprecated: "Use @callback and @macrocallback attributes instead"
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule Bitwise do
  @moduledoc """
  A set of functions that perform calculations on bits.
@@ -1,10 +1,4 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule Calendar do
-  @strftime_max_width 1024
-
  @moduledoc """
  This module defines the responsibilities for working with
  calendars, dates, times and datetimes in Elixir.
@@ -60,20 +54,9 @@ defmodule Calendar do
  @typedoc """
  Microseconds with stored precision.

-  `value` always represents the total value in microseconds.
-
-  The `precision` represents the number of digits that must be used when
+  The precision represents the number of digits that must be used when
  representing the microseconds to external format. If the precision is `0`,
-  it means microseconds must be skipped. If the precision is `6`, it means
-  that `value` represents exactly the number of microseconds to be used.
-
-  ## Examples
-
-    * `{0, 0}` means no microseconds.
-    * `{1, 6}` means 1µs.
-    * `{1000, 6}` means 1000µs (which is 1ms but measured at the microsecond precision).
-    * `{1000, 3}` means 1ms (which is measured at the millisecond precision).
-
+  it means microseconds must be skipped.
  """
  @type microsecond :: {value :: non_neg_integer, precision :: non_neg_integer}

@@ -106,7 +89,6 @@ defmodule Calendar do
  @typedoc "Any map or struct that contains the time fields."
  @type time :: %{
          optional(any) => any,
-          calendar: calendar,
          hour: hour,
          minute: minute,
          second: second,
@@ -165,22 +147,6 @@ defmodule Calendar do
  """
  @type time_zone_database :: module()

-  @typedoc """
-  Options for formatting dates and times with `strftime/3`.
-  """
-  @type strftime_opts :: [
-          preferred_datetime: String.t(),
-          preferred_date: String.t(),
-          preferred_time: String.t(),
-          am_pm_names: (:am | :pm -> String.t()) | (:am | :pm, map() -> String.t()),
-          month_names: (pos_integer() -> String.t()) | (pos_integer(), map() -> String.t()),
-          abbreviated_month_names:
-            (pos_integer() -> String.t()) | (pos_integer(), map() -> String.t()),
-          day_of_week_names: (pos_integer() -> String.t()) | (pos_integer(), map() -> String.t()),
-          abbreviated_day_of_week_names:
-            (pos_integer() -> String.t()) | (pos_integer(), map() -> String.t())
-        ]
-
  @doc """
  Returns how many days there are in the given month of the given year.
  """
@@ -206,15 +172,6 @@ defmodule Calendar do
  `starting_on` represents the starting day of the week. All
  calendars must support at least the `:default` value. They may
  also support other values representing their days of the week.
-
-  The value of `day_of_week` is an ordinal number meaning that a
-  value of `1` is defined to mean "first day of the week". It is
-  specifically not defined to mean `1` is `Monday`.
-
-  It is a requirement that `first_day_of_week` is less than `last_day_of_week`
-  and that `day_of_week` must be within that range. Therefore it can be said
-  that `day_of_week in first_day_of_week..last_day_of_week//1` must be
-  `true` for all values of `day_of_week`.
  """
  @callback day_of_week(year, month, day, starting_on :: :default | atom) ::
              {day_of_week(), first_day_of_week :: non_neg_integer(),
@@ -296,7 +253,7 @@ defmodule Calendar do
  @callback time_from_day_fraction(day_fraction) :: {hour, minute, second, microsecond}

  @doc """
-  Defines the rollover moment for the calendar.
+  Define the rollover moment for the calendar.

  This is the moment, in your calendar, when the current day ends
  and the next day starts.
@@ -382,13 +339,13 @@ defmodule Calendar do
  @callback iso_days_to_end_of_day(iso_days) :: iso_days

  @doc """
-  Shifts date by the given duration according to its calendar.
+  Shifts date by given duration according to its calendar.
  """
  @doc since: "1.17.0"
  @callback shift_date(year, month, day, Duration.t()) :: {year, month, day}

  @doc """
-  Shifts naive datetime by the given duration according to its calendar.
+  Shifts naive datetime by given duration according to its calendar.
  """
  @doc since: "1.17.0"
  @callback shift_naive_datetime(
@@ -403,7 +360,7 @@ defmodule Calendar do
            ) :: {year, month, day, hour, minute, second, microsecond}

  @doc """
-  Shifts time by the given duration according to its calendar.
+  Shifts time by given duration according to its calendar.
  """
  @doc since: "1.17.0"
  @callback shift_time(hour, minute, second, microsecond, Duration.t()) ::
@@ -495,30 +452,25 @@ defmodule Calendar do
      it can't contain the `%X` format and defaults to `"%H:%M:%S"`
      if the option is not received

-    * `:am_pm_names` - a function that receives either `:am` or `:pm`
-      (and also the datetime if the function is arity/2) and returns
+    * `:am_pm_names` - a function that receives either `:am` or `:pm` and returns
      the name of the period of the day, if the option is not received it defaults
      to a function that returns `"am"` and `"pm"`, respectively

-    *  `:month_names` - a function that receives a number (and also the
-      datetime if the function is arity/2) and returns the name of
+    *  `:month_names` - a function that receives a number and returns the name of
      the corresponding month, if the option is not received it defaults to a
      function that returns the month names in English

-    * `:abbreviated_month_names` - a function that receives a number (and also
-      the datetime if the function is arity/2) and returns the
+    * `:abbreviated_month_names` - a function that receives a number and returns the
      abbreviated name of the corresponding month, if the option is not received it
      defaults to a function that returns the abbreviated month names in English

-    * `:day_of_week_names` - a function that receives a number and (and also the
-      datetime if the function is arity/2) returns the name of
+    * `:day_of_week_names` - a function that receives a number and returns the name of
      the corresponding day of week, if the option is not received it defaults to a
      function that returns the day of week names in English

-    * `:abbreviated_day_of_week_names` - a function that receives a number (and also
-      the datetime if the function is arity/2) and returns the abbreviated name of
-      the corresponding day of week, if the option is not received it defaults to a
-      function that returns the abbreviated day of week names in English
+    * `:abbreviated_day_of_week_names` - a function that receives a number and returns
+      the abbreviated name of the corresponding day of week, if the option is not received
+      it defaults to a function that returns the abbreviated day of week names in English

  ## Formatting syntax

@@ -532,7 +484,6 @@ defmodule Calendar do
    * `%`: indicates the start of a formatted section
    * `<padding>`: set the padding (see below)
    * `<width>`: a number indicating the minimum size of the formatted section
-      (maximum #{@strftime_max_width})
    * `<format>`: the format itself (see below)

  ### Accepted padding options
@@ -553,7 +504,7 @@ defmodule Calendar do
  B      | Full month name                                                         | January
  c      | Preferred date+time representation                                      | 2018-10-17 12:34:56
  d      | Day of the month                                                        | 01, 31
-  f      | Microseconds (uses its precision for width and padding)                 | 000000, 999999, 0123
+  f      | Microseconds *(does not support width and padding modifiers)*           | 000000, 999999, 0123
  H      | Hour using a 24-hour clock                                              | 00, 23
  I      | Hour using a 12-hour clock                                              | 01, 12
  j      | Day of the year                                                         | 001, 366
@@ -563,11 +514,11 @@ defmodule Calendar do
  P      | "am" or "pm" (noon is "pm", midnight as "am")                           | am, pm
  q      | Quarter                                                                 | 1, 2, 3, 4
  s      | Number of seconds since the Epoch, 1970-01-01 00:00:00+0000 (UTC)       | 1565888877
-  S      | Second                                                                  | 00, 59
+  S      | Second                                                                  | 00, 59, 60
  u      | Day of the week                                                         | 1 (Monday), 7 (Sunday)
  x      | Preferred date (without time) representation                            | 2018-10-17
  X      | Preferred time (without date) representation                            | 12:34:56
-  y      | Year as 2-digits                                                        | -01, 01, 86, 18
+  y      | Year as 2-digits                                                        | 01, 01, 86, 18
  Y      | Year                                                                    | -0001, 0001, 1986
  z      | +hhmm/-hhmm time zone offset from UTC (empty string if naive)           | +0300, -0530
  Z      | Time zone abbreviation (empty string if naive)                          | CET, BRST
@@ -575,12 +526,6 @@ defmodule Calendar do

  Any other character will be interpreted as an invalid format and raise an error.

-  ### `%f` Microseconds
-
-  `%f` does not support width and padding modifiers.  It will be formatted by truncating
-  the microseconds to the precision of the `microseconds` field of the struct, with a
-  minimum precision of 1.
-
  ## Examples

  Without user options:
@@ -624,20 +569,9 @@ defmodule Calendar do
      ...>)
      "серпень"

-    Microsecond formatting:
-
-      iex> Calendar.strftime(~U[2019-08-26 13:52:06Z], "%y-%m-%d %H:%M:%S.%f")
-      "19-08-26 13:52:06.0"
-
-      iex> Calendar.strftime(~U[2019-08-26 13:52:06.048Z], "%y-%m-%d %H:%M:%S.%f")
-      "19-08-26 13:52:06.048"
-
-      iex> Calendar.strftime(~U[2019-08-26 13:52:06.048531Z], "%y-%m-%d %H:%M:%S.%f")
-      "19-08-26 13:52:06.048531"
-
  """
  @doc since: "1.11.0"
-  @spec strftime(map(), String.t(), strftime_opts()) :: String.t()
+  @spec strftime(map(), String.t(), keyword()) :: String.t()
  def strftime(date_or_time_or_datetime, string_format, user_options \\ [])
      when is_map(date_or_time_or_datetime) and is_binary(string_format) do
    parse(
@@ -671,13 +605,9 @@ defmodule Calendar do
  end

  defp parse_modifiers(<<digit, rest::binary>>, width, pad, parser_data) when digit in ?0..?9 do
-    width = (width || 0) * 10 + (digit - ?0)
+    new_width = (width || 0) * 10 + (digit - ?0)

-    if width > @strftime_max_width do
-      raise ArgumentError, "invalid strftime format: width must be at most #{@strftime_max_width}"
-    end
-
-    parse_modifiers(rest, width, pad, parser_data)
+    parse_modifiers(rest, new_width, pad, parser_data)
  end

  # set default padding if none was specified
@@ -694,12 +624,12 @@ defmodule Calendar do
    format_modifiers(rest, width, pad, datetime, format_options, acc)
  end

-  defp am_pm(hour, format_options, datetime) when hour > 11 do
-    apply_format(:pm, format_options.am_pm_names, datetime)
+  defp am_pm(hour, format_options) when hour > 11 do
+    format_options.am_pm_names.(:pm)
  end

-  defp am_pm(hour, format_options, datetime) when hour <= 11 do
-    apply_format(:am, format_options.am_pm_names, datetime)
+  defp am_pm(hour, format_options) when hour <= 11 do
+    format_options.am_pm_names.(:am)
  end

  defp default_pad(format) when format in ~c"aAbBpPZ", do: ?\s
@@ -712,7 +642,7 @@ defmodule Calendar do

  # Literally just %
  defp format_modifiers("%" <> rest, width, pad, datetime, format_options, acc) do
-    parse(rest, datetime, format_options, [pad_leading_ascii("%", width, pad) | acc])
+    parse(rest, datetime, format_options, [pad_leading("%", width, pad) | acc])
  end

  # Abbreviated name of day
@@ -720,7 +650,7 @@ defmodule Calendar do
    result =
      datetime
      |> Date.day_of_week()
-      |> apply_format(format_options.abbreviated_day_of_week_names, datetime)
+      |> format_options.abbreviated_day_of_week_names.()
      |> pad_leading(width, pad)

    parse(rest, datetime, format_options, [result | acc])
@@ -731,7 +661,7 @@ defmodule Calendar do
    result =
      datetime
      |> Date.day_of_week()
-      |> apply_format(format_options.day_of_week_names, datetime)
+      |> format_options.day_of_week_names.()
      |> pad_leading(width, pad)

    parse(rest, datetime, format_options, [result | acc])
@@ -741,7 +671,7 @@ defmodule Calendar do
  defp format_modifiers("b" <> rest, width, pad, datetime, format_options, acc) do
    result =
      datetime.month
-      |> apply_format(format_options.abbreviated_month_names, datetime)
+      |> format_options.abbreviated_month_names.()
      |> pad_leading(width, pad)

    parse(rest, datetime, format_options, [result | acc])
@@ -749,10 +679,7 @@ defmodule Calendar do

  # Full month name
  defp format_modifiers("B" <> rest, width, pad, datetime, format_options, acc) do
-    result =
-      datetime.month
-      |> apply_format(format_options.month_names, datetime)
-      |> pad_leading(width, pad)
+    result = datetime.month |> format_options.month_names.() |> pad_leading(width, pad)

    parse(rest, datetime, format_options, [result | acc])
  end
@@ -781,7 +708,7 @@ defmodule Calendar do

  # Day of the month
  defp format_modifiers("d" <> rest, width, pad, datetime, format_options, acc) do
-    result = datetime.day |> Integer.to_string() |> pad_leading_ascii(width, pad)
+    result = datetime.day |> Integer.to_string() |> pad_leading(width, pad)
    parse(rest, datetime, format_options, [result | acc])
  end

@@ -800,45 +727,37 @@ defmodule Calendar do

  # Hour using a 24-hour clock
  defp format_modifiers("H" <> rest, width, pad, datetime, format_options, acc) do
-    result = datetime.hour |> Integer.to_string() |> pad_leading_ascii(width, pad)
+    result = datetime.hour |> Integer.to_string() |> pad_leading(width, pad)
    parse(rest, datetime, format_options, [result | acc])
  end

  # Hour using a 12-hour clock
  defp format_modifiers("I" <> rest, width, pad, datetime, format_options, acc) do
-    result =
-      (rem(datetime.hour + 23, 12) + 1) |> Integer.to_string() |> pad_leading_ascii(width, pad)
-
+    result = (rem(datetime.hour + 23, 12) + 1) |> Integer.to_string() |> pad_leading(width, pad)
    parse(rest, datetime, format_options, [result | acc])
  end

  # Day of the year
  defp format_modifiers("j" <> rest, width, pad, datetime, format_options, acc) do
-    result =
-      datetime |> Date.day_of_year() |> Integer.to_string() |> pad_leading_ascii(width, pad)
-
+    result = datetime |> Date.day_of_year() |> Integer.to_string() |> pad_leading(width, pad)
    parse(rest, datetime, format_options, [result | acc])
  end

  # Month
  defp format_modifiers("m" <> rest, width, pad, datetime, format_options, acc) do
-    result = datetime.month |> Integer.to_string() |> pad_leading_ascii(width, pad)
+    result = datetime.month |> Integer.to_string() |> pad_leading(width, pad)
    parse(rest, datetime, format_options, [result | acc])
  end

  # Minute
  defp format_modifiers("M" <> rest, width, pad, datetime, format_options, acc) do
-    result = datetime.minute |> Integer.to_string() |> pad_leading_ascii(width, pad)
+    result = datetime.minute |> Integer.to_string() |> pad_leading(width, pad)
    parse(rest, datetime, format_options, [result | acc])
  end

  # "AM" or "PM" (noon is "PM", midnight as "AM")
  defp format_modifiers("p" <> rest, width, pad, datetime, format_options, acc) do
-    result =
-      datetime.hour
-      |> am_pm(format_options, datetime)
-      |> String.upcase()
-      |> pad_leading(width, pad)
+    result = datetime.hour |> am_pm(format_options) |> String.upcase() |> pad_leading(width, pad)

    parse(rest, datetime, format_options, [result | acc])
  end
@@ -847,7 +766,7 @@ defmodule Calendar do
  defp format_modifiers("P" <> rest, width, pad, datetime, format_options, acc) do
    result =
      datetime.hour
-      |> am_pm(format_options, datetime)
+      |> am_pm(format_options)
      |> String.downcase()
      |> pad_leading(width, pad)

@@ -856,23 +775,19 @@ defmodule Calendar do

  # Quarter
  defp format_modifiers("q" <> rest, width, pad, datetime, format_options, acc) do
-    result =
-      datetime |> Date.quarter_of_year() |> Integer.to_string() |> pad_leading_ascii(width, pad)
-
+    result = datetime |> Date.quarter_of_year() |> Integer.to_string() |> pad_leading(width, pad)
    parse(rest, datetime, format_options, [result | acc])
  end

  # Second
  defp format_modifiers("S" <> rest, width, pad, datetime, format_options, acc) do
-    result = datetime.second |> Integer.to_string() |> pad_leading_ascii(width, pad)
+    result = datetime.second |> Integer.to_string() |> pad_leading(width, pad)
    parse(rest, datetime, format_options, [result | acc])
  end

  # Day of the week
  defp format_modifiers("u" <> rest, width, pad, datetime, format_options, acc) do
-    result =
-      datetime |> Date.day_of_week() |> Integer.to_string() |> pad_leading_ascii(width, pad)
-
+    result = datetime |> Date.day_of_week() |> Integer.to_string() |> pad_leading(width, pad)
    parse(rest, datetime, format_options, [result | acc])
  end

@@ -922,25 +837,20 @@ defmodule Calendar do

  # Year as 2-digits
  defp format_modifiers("y" <> rest, width, pad, datetime, format_options, acc) do
-    result =
-      if datetime.year < 0 do
-        [?- | -datetime.year |> rem(100) |> Integer.to_string() |> pad_leading_ascii(width, pad)]
-      else
-        datetime.year |> rem(100) |> Integer.to_string() |> pad_leading_ascii(width, pad)
-      end
-
+    result = datetime.year |> rem(100) |> Integer.to_string() |> pad_leading(width, pad)
    parse(rest, datetime, format_options, [result | acc])
  end

  # Year
  defp format_modifiers("Y" <> rest, width, pad, datetime, format_options, acc) do
-    result =
+    {sign, year} =
      if datetime.year < 0 do
-        [?- | -datetime.year |> Integer.to_string() |> pad_leading_ascii(width, pad)]
+        {?-, -datetime.year}
      else
-        datetime.year |> Integer.to_string() |> pad_leading_ascii(width, pad)
+        {[], datetime.year}
      end

+    result = [sign | year |> Integer.to_string() |> pad_leading(width, pad)]
    parse(rest, datetime, format_options, [result | acc])
  end

@@ -987,7 +897,7 @@ defmodule Calendar do
      Integer.to_string(div(absolute_offset, 3600) * 100 + rem(div(absolute_offset, 60), 60))

    sign = if utc_offset + std_offset >= 0, do: "+", else: "-"
-    result = "#{sign}#{pad_leading_ascii(offset_number, width, pad)}"
+    result = "#{sign}#{pad_leading(offset_number, width, pad)}"
    parse(rest, datetime, format_options, [result | acc])
  end

@@ -1006,19 +916,13 @@ defmodule Calendar do
    raise ArgumentError, "invalid strftime format: %#{next}"
  end

-  defp pad_preferred(result, width, pad) do
-    result
-    |> IO.iodata_to_binary()
-    |> pad_leading(width, pad)
+  defp pad_preferred(result, width, pad) when length(result) < width do
+    pad_preferred([pad | result], width, pad)
  end

+  defp pad_preferred(result, _width, _pad), do: result
+
  defp pad_leading(string, count, padding) do
-    to_pad = count - String.length(string)
-    if to_pad > 0, do: do_pad_leading(to_pad, padding, string), else: string
-  end
-
-  # Similar to `pad_leading/3`, but only for strings that always ASCII-only
-  defp pad_leading_ascii(string, count, padding) do
    to_pad = count - byte_size(string)
    if to_pad > 0, do: do_pad_leading(to_pad, padding, string), else: string
  end
@@ -1028,18 +932,6 @@ defmodule Calendar do
  defp do_pad_leading(count, padding, acc),
    do: do_pad_leading(count - 1, padding, [padding | acc])

-  defp apply_format(term, formatter, _datetime) when is_function(formatter, 1) do
-    formatter.(term)
-  end
-
-  defp apply_format(term, formatter, datetime) when is_function(formatter, 2) do
-    formatter.(term, datetime)
-  end
-
-  defp apply_format(_term, formatter, _datetime) do
-    raise ArgumentError, "formatter functions must be of arity 1 or 2, got: #{inspect(formatter)}"
-  end
-
  defp options(user_options) do
    default_options = %{
      preferred_date: "%Y-%m-%d",
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule Date do
  @moduledoc """
  A Date struct and functions.
@@ -35,12 +31,11 @@ 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`, `after?/2` and `before?/2` functions.
-  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:
+  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)
+      iex>  Enum.min([~D[2017-03-31], ~D[2017-04-01]], Date)
      ~D[2017-03-31]

  ## Using epochs
@@ -53,7 +48,7 @@ defmodule Date do
      iex> Date.diff(~D[2010-04-17], ~D[1970-01-01])
      14716

-      iex> Date.add(~D[1970-01-01], 14_716)
+      iex> Date.add(~D[1970-01-01], 14716)
      ~D[2010-04-17]

      iex> Date.shift(~D[1970-01-01], year: 40, month: 3, week: 2, day: 2)
@@ -81,7 +76,7 @@ defmodule Date do

  Ranges of dates can be increasing (`first <= last`) and are
  always inclusive. For a decreasing range, use `range/3` with
-  a step of -1 as third argument.
+  a step of -1 as first argument.

  ## Examples

@@ -160,7 +155,7 @@ defmodule Date do
      ) do
    raise ArgumentError,
          "both dates must have matching calendar and the step must be a " <>
-            "non-zero integer, got: #{inspect(first)}, #{inspect(last)}, #{inspect(step)}"
+            "non-zero integer, got: #{inspect(first)}, #{inspect(last)}, #{step}"
  end

  defp range(first, first_days, last, last_days, calendar, step) do
@@ -193,8 +188,9 @@ defmodule Date do
  end

  def utc_today(calendar) do
-    %{year: year, month: month, day: day} = DateTime.utc_now(calendar)
-    %Date{year: year, month: month, day: day, calendar: calendar}
+    calendar
+    |> DateTime.utc_now()
+    |> DateTime.to_date()
  end

  @doc """
@@ -321,7 +317,7 @@ defmodule Date do
  @doc """
  Converts the given date to a string according to its calendar.

-  ## Examples
+  ### Examples

      iex> Date.to_string(~D[2000-02-28])
      "2000-02-28"
@@ -399,7 +395,7 @@ defmodule Date do
  or other calendars in which the days also start at midnight.
  Attempting to convert dates from other calendars will raise an `ArgumentError`.

-  ## Examples
+  ### Examples

      iex> Date.to_iso8601(~D[2000-02-28])
      "2000-02-28"
@@ -422,7 +418,7 @@ defmodule Date do
  def to_iso8601(%{calendar: _} = date, format) when format in [:basic, :extended] do
    date
    |> convert!(Calendar.ISO)
-    |> to_iso8601(format)
+    |> to_iso8601()
  end

  @doc """
@@ -556,18 +552,14 @@ defmodule Date do
  """
  @doc since: "1.4.0"
  @spec compare(Calendar.date(), Calendar.date()) :: :lt | :eq | :gt
-  def compare(
-        %{year: year1, month: month1, day: day1, calendar: calendar},
-        %{year: year2, month: month2, day: day2, calendar: calendar}
-      ) do
-    cond do
-      year1 > year2 -> :gt
-      year1 < year2 -> :lt
-      month1 > month2 -> :gt
-      month1 < month2 -> :lt
-      day1 > day2 -> :gt
-      day1 < day2 -> :lt
-      true -> :eq
+  def compare(%{calendar: calendar} = date1, %{calendar: calendar} = date2) do
+    %{year: year1, month: month1, day: day1} = date1
+    %{year: year2, month: month2, day: day2} = date2
+
+    case {{year1, month1, day1}, {year2, month2, day2}} do
+      {first, second} when first > second -> :gt
+      {first, second} when first < second -> :lt
+      _ -> :eq
    end
  end

@@ -637,7 +629,7 @@ defmodule Date do
  ## Examples

  Imagine someone implements `Calendar.Holocene`, a calendar based on the
-  Gregorian calendar that adds exactly 10 000 years to the current Gregorian
+  Gregorian calendar that adds exactly 10,000 years to the current Gregorian
  year:

      iex> Date.convert(~D[2000-01-01], Calendar.Holocene)
@@ -671,7 +663,7 @@ defmodule Date do
  ## Examples

  Imagine someone implements `Calendar.Holocene`, a calendar based on the
-  Gregorian calendar that adds exactly 10 000 years to the current Gregorian
+  Gregorian calendar that adds exactly 10,000 years to the current Gregorian
  year:

      iex> Date.convert!(~D[2000-01-01], Calendar.Holocene)
@@ -695,15 +687,10 @@ defmodule Date do
  @doc """
  Adds the number of days to the given `date`.

-  > #### Prefer `shift/2` {: .info}
-  >
-  > Prefer `shift/2` over `add/2`, as it offers a more ergonomic API.
-  >
-  > `add/2` always considers a day to be measured according to the
-  > `Calendar.ISO`.
+  The days are counted as Gregorian days. The date is returned in the same
+  calendar as it was given in.

-  The days are counted as Gregorian days, independent of the underlying
-  calendar. The date is returned in the same calendar as it was given in.
+  To shift a date by a `Duration` and according to its underlying calendar, use `Date.shift/2`.

  ## Examples

@@ -777,9 +764,8 @@ defmodule Date do

  When using the default ISO calendar, durations are collapsed and
  applied in the order of months and then days:
-
-  * when shifting by 1 year and 2 months the date is actually shifted by 14 months
-  * when shifting by 2 weeks and 3 days the date is shifted by 17 days
+  - when shifting by 1 year and 2 months the date is actually shifted by 14 months
+  - when shifting by 2 weeks and 3 days the date is shifted by 17 days

  When shifting by month, days are rounded down to the nearest valid date.

@@ -865,7 +851,7 @@ defmodule Date do
  end

  @doc """
-  Calculates the ordinal day of the week of a given `date`.
+  Calculates the day of the week of a given `date`.

  Returns the day of the week as an integer. For the ISO 8601
  calendar (the default), it is an integer from 1 to 7, where
@@ -874,19 +860,10 @@ defmodule Date do
  An optional `starting_on` value may be supplied, which
  configures the weekday the week starts on. The default value
  for it is `:default`, which translates to `:monday` for the
-  built-in ISO 8601 calendar. Any other weekday may be used for
-  `starting_on`, in such cases, that weekday will be considered the first
-  day of the week, and therefore it will be assigned the ordinal number 1.
-
-  The other calendars, the value returned is an ordinal day of week.
-  For example, `1` may mean "first day of the week" and `7` is
-  defined to mean "seventh day of the week". Custom calendars may
-  also accept their own variations of the `starting_on` parameter
-  with their own meaning.
+  built-in ISO calendar. Any other weekday may be given to.

  ## Examples

-      # 2016-10-31 is a Monday and by default Monday is the first day of the week
      iex> Date.day_of_week(~D[2016-10-31])
      1
      iex> Date.day_of_week(~D[2016-11-01])
@@ -896,7 +873,6 @@ defmodule Date do
      iex> Date.day_of_week(~D[-0015-10-30])
      3

-      # 2016-10-31 is a Monday but, as we start the week on Sunday, now it returns 2
      iex> Date.day_of_week(~D[2016-10-31], :sunday)
      2
      iex> Date.day_of_week(~D[2016-11-01], :sunday)
@@ -1051,7 +1027,7 @@ defmodule Date do
  @doc """
  Calculates the quarter of the year of a given `date`.

-  Returns the quarter of the year as an integer. For the ISO 8601
+  Returns the day of the year as an integer. For the ISO 8601
  calendar (the default), it is an integer from 1 to 4.

  ## Examples
@@ -1096,7 +1072,13 @@ defmodule Date do
  def year_of_era(date)

  def year_of_era(%{calendar: calendar, year: year, month: month, day: day}) do
-    calendar.year_of_era(year, month, day)
+    # 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
  end

  @doc """
@@ -1176,11 +1158,12 @@ defmodule Date do

  defimpl Inspect do
    def inspect(%{calendar: calendar, year: year, month: month, day: day}, _)
-        when calendar != Calendar.ISO or year in -9999..9999 do
+        when year in -9999..9999 do
      "~D[" <> calendar.date_to_string(year, month, day) <> suffix(calendar) <> "]"
    end

-    def inspect(%{calendar: Calendar.ISO, year: year, month: month, day: day}, _) do
+    def inspect(%{calendar: calendar, year: year, month: month, day: day}, _)
+        when calendar == Calendar.ISO do
      "Date.new!(#{Integer.to_string(year)}, #{Integer.to_string(month)}, #{Integer.to_string(day)})"
    end

@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule Date.Range do
  @moduledoc """
  Returns an inclusive range between dates.
@@ -37,19 +33,21 @@ defmodule Date.Range do
            first_in_iso_days: first_days,
            last_in_iso_days: last_days,
            step: step
-          },
+          } = range,
          %Date{calendar: calendar} = date
        ) do
      {days, _} = Date.to_iso_days(date)

-      in_range? =
-        if step > 0 do
-          first_days <= days and days <= last_days and rem(days - first_days, step) == 0
-        else
-          last_days <= days and days <= first_days and rem(days - first_days, step) == 0
-        end
+      cond do
+        empty?(range) ->
+          {:ok, false}

-      {:ok, in_range?}
+        first_days <= last_days ->
+          {:ok, first_days <= days and days <= last_days and rem(days - first_days, step) == 0}
+
+        true ->
+          {:ok, last_days <= days and days <= first_days and rem(days - first_days, step) == 0}
+      end
    end

    def member?(%Date.Range{step: _}, _) do
@@ -57,20 +55,11 @@ defmodule Date.Range do
    end

    # TODO: Remove me on v2.0
-    member? =
-      quote generated: true do
-        member?(
-          %{
-            __struct__: Date.Range,
-            first_in_iso_days: var!(first_days),
-            last_in_iso_days: var!(last_days)
-          } =
-            var!(date_range),
-          var!(date)
-        )
-      end
-
-    def unquote(member?) do
+    def member?(
+          %{__struct__: Date.Range, first_in_iso_days: first_days, last_in_iso_days: last_days} =
+            date_range,
+          date
+        ) do
      step = if first_days <= last_days, do: 1, else: -1
      member?(Map.put(date_range, :step, step), date)
    end
@@ -86,7 +75,7 @@ defmodule Date.Range do
            step: step
          } = range
        ) do
-      {:ok, size(range), &slice(first + &1 * step, step * &3, &2, calendar)}
+      {:ok, size(range), &slice(first + &1 * step, step + &3 - 1, &2, calendar)}
    end

    # TODO: Remove me on v2.0
@@ -102,7 +91,7 @@ defmodule Date.Range do
      [date_from_iso_days(current, calendar)]
    end

-    defp slice(current, step, remaining, calendar) when remaining > 1 do
+    defp slice(current, step, remaining, calendar) do
      [
        date_from_iso_days(current, calendar)
        | slice(current + step, step, remaining - 1, calendar)
@@ -178,12 +167,8 @@ defmodule Date.Range do
         when step < 0 and first_days < last_days,
         do: 0

-    defp size(%Date.Range{
-           first_in_iso_days: first_days,
-           last_in_iso_days: last_days,
-           step: step
-         }),
-         do: div(last_days - first_days, step) + 1
+    defp size(%Date.Range{first_in_iso_days: first_days, last_in_iso_days: last_days, step: step}),
+      do: abs(div(last_days - first_days, step)) + 1

    # TODO: Remove me on v2.0
    defp size(
@@ -193,16 +178,43 @@ defmodule Date.Range do
      step = if first_days <= last_days, do: 1, else: -1
      size(Map.put(date_range, :step, step))
    end
+
+    defp empty?(%Date.Range{
+           first_in_iso_days: first_days,
+           last_in_iso_days: last_days,
+           step: step
+         })
+         when step > 0 and first_days > last_days,
+         do: true
+
+    defp empty?(%Date.Range{
+           first_in_iso_days: first_days,
+           last_in_iso_days: last_days,
+           step: step
+         })
+         when step < 0 and first_days < last_days,
+         do: true
+
+    defp empty?(%Date.Range{step: _}), do: false
+
+    # TODO: Remove me on v2.0
+    defp empty?(
+           %{__struct__: Date.Range, first_in_iso_days: first_days, last_in_iso_days: last_days} =
+             date_range
+         ) do
+      step = if first_days <= last_days, do: 1, else: -1
+      empty?(Map.put(date_range, :step, step))
+    end
  end

  defimpl Inspect do
    import Kernel, except: [inspect: 2]

-    def inspect(%Date.Range{first: first, last: last, step: 1}, %Inspect.Opts{}) do
+    def inspect(%Date.Range{first: first, last: last, step: 1}, _) do
      "Date.range(" <> inspect(first) <> ", " <> inspect(last) <> ")"
    end

-    def inspect(%Date.Range{first: first, last: last, step: step}, %Inspect.Opts{}) do
+    def inspect(%Date.Range{first: first, last: last, step: step}, _) do
      "Date.range(" <> inspect(first) <> ", " <> inspect(last) <> ", #{step})"
    end

@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule DateTime do
  @moduledoc """
  A datetime implementation with a time zone.
@@ -17,8 +13,8 @@ defmodule DateTime do

  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`, `after?/2` and `before?/2` functions.
-  The existence of the `compare/2` function in this module also allows
+  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:

@@ -32,12 +28,7 @@ defmodule DateTime do
  ## Time zone database

  Many functions in this module require a time zone database.
-  A time zone database is a record of the UTC offsets that its locales have
-  used at various times in the past, are using, and are expected to use in the
-  future.
-  Because those plans can change, it needs to be periodically updated.
-
-  By default, `DateTime` uses the default time zone database returned by
+  By default, it uses the default time zone database returned by
  `Calendar.get_time_zone_database/0`, which defaults to
  `Calendar.UTCOnlyTimeZoneDatabase` which only handles "Etc/UTC"
  datetimes and returns `{:error, :utc_only_time_zone_database}`
@@ -52,7 +43,7 @@ defmodule DateTime do
    * [`zoneinfo`](https://github.com/smartrent/zoneinfo) -
      recommended for embedded devices

-  To use one of them, first make sure it is added as a dependency in `mix.exs`.
+  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
@@ -180,7 +171,7 @@ defmodule DateTime do
  since v1.15.0.

  The default unit if none gets passed is `:native`,
-  which results in a default resolution of microseconds.
+  which results on a default resolution of microseconds.

  ## Examples

@@ -383,12 +374,13 @@ defmodule DateTime do
  @doc """
  Converts the given Unix time to `DateTime`.

-  The integer can be given in different unit, according to `System.convert_time_unit/3`,
-  and it will be converted to microseconds internally, which is the maximum precision
-  supported by `DateTime`. In other words, any precision higher than microseconds will
-  lead to truncation.
+  The integer can be given in different unit
+  according to `System.convert_time_unit/3` and it will
+  be converted to microseconds internally. Up to
+  253402300799 seconds is supported.

-  Unix times are always in UTC. Therefore the DateTime will be returned in UTC.
+  Unix times are always in UTC and therefore the DateTime
+  will be returned in UTC.

  ## Examples

@@ -720,9 +712,6 @@ defmodule DateTime do
  Other time zone databases can be passed as argument or set globally.
  See the "Time zone database" section in the module docs.

-  Shifting to the `"Etc/UTC"` time zone always succeeds without
-  consulting the `time_zone_database`.
-
  ## Examples

      iex> {:ok, pacific_datetime} = DateTime.shift_zone(~U[2018-07-16 10:00:00Z], "America/Los_Angeles", FakeTimeZoneDatabase)
@@ -756,28 +745,6 @@ defmodule DateTime do
    |> shift_zone_for_iso_days_utc(calendar, precision, time_zone, time_zone_database)
  end

-  defp shift_zone_for_iso_days_utc(iso_days_utc, calendar, precision, "Etc/UTC", _time_zone_db) do
-    {year, month, day, hour, minute, second, {microsecond, _}} =
-      calendar.naive_datetime_from_iso_days(iso_days_utc)
-
-    datetime = %DateTime{
-      calendar: calendar,
-      year: year,
-      month: month,
-      day: day,
-      hour: hour,
-      minute: minute,
-      second: second,
-      microsecond: {microsecond, precision},
-      std_offset: 0,
-      utc_offset: 0,
-      zone_abbr: "UTC",
-      time_zone: "Etc/UTC"
-    }
-
-    {:ok, datetime}
-  end
-
  defp shift_zone_for_iso_days_utc(iso_days_utc, calendar, precision, time_zone, time_zone_db) do
    case time_zone_db.time_zone_period_from_utc_iso_days(iso_days_utc, time_zone) do
      {:ok, %{std_offset: std_offset, utc_offset: utc_offset, zone_abbr: zone_abbr}} ->
@@ -909,10 +876,8 @@ defmodule DateTime do
  The `datetime` is expected to be using the ISO calendar
  with a year greater than or equal to 0.

-  It will return the integer with the given unit, according
-  to `System.convert_time_unit/3`. If the given unit is different
-  than microseconds, the returned value will be either truncated
-  or padded accordingly.
+  It will return the integer with the given unit,
+  according to `System.convert_time_unit/3`.

  ## Examples

@@ -1060,18 +1025,15 @@ defmodule DateTime do
  By default, `DateTime.to_iso8601/2` returns datetimes formatted in the "extended"
  format, for human readability. It also supports the "basic" format through passing the `:basic` option.

+  Only supports converting datetimes which are in the ISO calendar,
+  attempting to convert datetimes from other calendars will raise.
  You can also optionally specify an offset for the formatted string.
-  If none is given, the one in the given `datetime` is used.
-
-  Only supports converting datetimes which are in the ISO calendar.
-  If another calendar is given, it is automatically converted to ISO.
-  It raises if not possible.

  WARNING: the ISO 8601 datetime format does not contain the time zone nor
  its abbreviation, which means information is lost when converting to such
  format.

-  ## Examples
+  ### Examples

      iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "CET",
      ...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
@@ -1121,21 +1083,8 @@ defmodule DateTime do
  @spec to_iso8601(Calendar.datetime(), :basic | :extended, nil | integer()) :: String.t()
  def to_iso8601(datetime, format \\ :extended, offset \\ nil)

-  def to_iso8601(%{calendar: Calendar.ISO} = datetime, format, offset)
+  def to_iso8601(%{calendar: Calendar.ISO} = datetime, format, nil)
      when format in [:extended, :basic] do
-    datetime
-    |> to_iso8601_iodata(format, offset)
-    |> IO.iodata_to_binary()
-  end
-
-  def to_iso8601(%{calendar: _} = datetime, format, offset)
-      when format in [:extended, :basic] do
-    datetime
-    |> convert!(Calendar.ISO)
-    |> to_iso8601(format, offset)
-  end
-
-  defp to_iso8601_iodata(datetime, format, nil) do
    %{
      year: year,
      month: month,
@@ -1149,51 +1098,35 @@ defmodule DateTime do
      std_offset: std_offset
    } = datetime

-    [
-      datetime_to_iodata(year, month, day, hour, minute, second, microsecond, format),
-      Calendar.ISO.offset_to_iodata(utc_offset, std_offset, time_zone, format)
-    ]
+    datetime_to_string(year, month, day, hour, minute, second, microsecond, format) <>
+      Calendar.ISO.offset_to_string(utc_offset, std_offset, time_zone, format)
  end

-  defp to_iso8601_iodata(
-         %{microsecond: {_, precision}, time_zone: "Etc/UTC"} = datetime,
-         format,
-         0
-       ) do
+  def to_iso8601(
+        %{calendar: Calendar.ISO, microsecond: {_, precision}, time_zone: "Etc/UTC"} = datetime,
+        format,
+        0
+      )
+      when format in [:extended, :basic] do
    {year, month, day, hour, minute, second, {microsecond, _}} = shift_by_offset(datetime, 0)

-    [
-      datetime_to_iodata(
-        year,
-        month,
-        day,
-        hour,
-        minute,
-        second,
-        {microsecond, precision},
-        format
-      ),
-      ?Z
-    ]
+    datetime_to_string(year, month, day, hour, minute, second, {microsecond, precision}, format) <>
+      "Z"
  end

-  defp to_iso8601_iodata(datetime, format, offset) do
+  def to_iso8601(%{calendar: Calendar.ISO} = datetime, format, offset)
+      when format in [:extended, :basic] do
    {_, precision} = datetime.microsecond
    {year, month, day, hour, minute, second, {microsecond, _}} = shift_by_offset(datetime, offset)

-    [
-      datetime_to_iodata(
-        year,
-        month,
-        day,
-        hour,
-        minute,
-        second,
-        {microsecond, precision},
-        format
-      ),
-      Calendar.ISO.offset_to_iodata(offset, 0, nil, format)
-    ]
+    datetime_to_string(year, month, day, hour, minute, second, {microsecond, precision}, format) <>
+      Calendar.ISO.offset_to_string(offset, 0, nil, format)
+  end
+
+  def to_iso8601(%{calendar: _} = datetime, format, offset) when format in [:extended, :basic] do
+    datetime
+    |> convert!(Calendar.ISO)
+    |> to_iso8601(format, offset)
  end

  defp shift_by_offset(%{calendar: calendar} = datetime, offset) do
@@ -1202,16 +1135,14 @@ defmodule DateTime do
    datetime
    |> to_iso_days()
    # Subtract total original offset in order to get UTC and add the new offset
-    |> Calendar.ISO.add_time_unit_to_iso_days(offset - total_offset, :second)
+    |> Calendar.ISO.add_day_fraction_to_iso_days(offset - total_offset, 86400)
    |> calendar.naive_datetime_from_iso_days()
  end

-  defp datetime_to_iodata(year, month, day, hour, minute, second, microsecond, format) do
-    [
-      Calendar.ISO.date_to_iodata(year, month, day, format),
-      ?T,
-      Calendar.ISO.time_to_iodata(hour, minute, second, microsecond, format)
-    ]
+  defp datetime_to_string(year, month, day, hour, minute, second, microsecond, format) do
+    Calendar.ISO.date_to_string(year, month, day, format) <>
+      "T" <>
+      Calendar.ISO.time_to_string(hour, minute, second, microsecond, format)
  end

  @doc """
@@ -1321,9 +1252,9 @@ defmodule DateTime do
  end

  @doc """
-  Converts a number of Gregorian seconds to a `DateTime` struct.
+  Converts a number of gregorian seconds to a `DateTime` struct.

-  The returned `DateTime` will have `UTC` timezone, if you want another timezone, please use
+  The returned `DateTime` will have `UTC` timezone, if you want other timezone, please use
  `DateTime.shift_zone/3`.

  ## Examples
@@ -1366,7 +1297,7 @@ defmodule DateTime do
  end

  @doc """
-  Converts a `DateTime` struct to a number of Gregorian seconds and microseconds.
+  Converts a `DateTime` struct to a number of gregorian seconds and microseconds.

  ## Examples

@@ -1410,12 +1341,7 @@ defmodule DateTime do
  @doc """
  Converts the given `datetime` to a string according to its calendar.

-  Unfortunately, there is no standard that specifies rendering of a
-  datetime with its complete time zone information, so Elixir uses a
-  custom (but relatively common) representation which appends the time
-  zone abbreviation and full name to the datetime.
-
-  ## Examples
+  ### Examples

      iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "CET",
      ...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
@@ -1601,15 +1527,15 @@ defmodule DateTime do
  def diff(datetime1, datetime2, unit \\ :second)

  def diff(datetime1, datetime2, :day) do
-    diff(datetime1, datetime2, :microsecond) |> div(86_400_000_000)
+    diff(datetime1, datetime2, :second) |> div(86400)
  end

  def diff(datetime1, datetime2, :hour) do
-    diff(datetime1, datetime2, :microsecond) |> div(3_600_000_000)
+    diff(datetime1, datetime2, :second) |> div(3600)
  end

  def diff(datetime1, datetime2, :minute) do
-    diff(datetime1, datetime2, :microsecond) |> div(60_000_000)
+    diff(datetime1, datetime2, :second) |> div(60)
  end

  def diff(
@@ -1624,60 +1550,42 @@ defmodule DateTime do
    end

    naive_diff =
-      (datetime1 |> to_iso_days() |> Calendar.ISO.iso_days_to_unit(:microsecond)) -
-        (datetime2 |> to_iso_days() |> Calendar.ISO.iso_days_to_unit(:microsecond))
+      (datetime1 |> to_iso_days() |> Calendar.ISO.iso_days_to_unit(unit)) -
+        (datetime2 |> to_iso_days() |> Calendar.ISO.iso_days_to_unit(unit))

    offset_diff = utc_offset2 + std_offset2 - (utc_offset1 + std_offset1)
-
-    System.convert_time_unit(naive_diff, :microsecond, unit) +
-      System.convert_time_unit(offset_diff, :second, unit)
+    naive_diff + System.convert_time_unit(offset_diff, :second, unit)
  end

  @doc """
  Adds a specified amount of time to a `DateTime`.

-  > #### Prefer `shift/2` {: .info}
-  >
-  > Prefer `shift/2` over `add/3`, as it offers a more ergonomic API.
-  >
-  > `add/3` provides a lower-level API which only supports fixed units
-  > such as `:hour` and `:second`, but not `:month` (as the exact length
-  > of a month depends on the current month). `add/3` always considers
-  > the unit to be computed according to the `Calendar.ISO`.
-
  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` for convenience but ultimately they are
-  all converted to microseconds. Negative values will move backwards
-  in time and the default precision is `:second`.
+  `t:System.time_unit/0`. It defaults to `:second`. Negative values
+  will move backwards in time.

-  If the datetime is in the `"Etc/UTC"` time zone, this function
-  always succeeds without consulting the `time_zone_database`.
+  This function always considers the unit to be computed according
+  to the `Calendar.ISO`.

  This function relies on a contiguous representation of time,
-  ignoring 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 elapsed 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.
+  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 elapsed 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 elapsed time,
-  its result may be confusing in certain use cases. For example, if a
+  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.
+  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.

-  In case you don't want these changes to happen automatically or you
-  want to surface time zone conflicts to the user, you can add to
-  the datetime as a naive datetime and then use `from_naive/2`:
-
-      dt |> NaiveDateTime.add(1, :day) |> DateTime.from_naive(dt.time_zone)
-
-  The above will surface time jumps and ambiguous datetimes, allowing you
-  to deal with them accordingly.
-
-  ## Examples
+  ### Examples

      iex> dt = DateTime.from_naive!(~N[2018-11-15 10:00:00], "Europe/Copenhagen", FakeTimeZoneDatabase)
      iex> dt |> DateTime.add(3600, :second, FakeTimeZoneDatabase)
@@ -1705,6 +1613,8 @@ defmodule DateTime do
      iex> result.microsecond
      {21000, 3}

+  To shift a datetime by a `Duration` and according to its underlying calendar, use `DateTime.shift/3`.
+
  """
  @doc since: "1.8.0"
  @spec add(
@@ -1772,16 +1682,13 @@ defmodule DateTime do

  Allowed units are: `:year`, `:month`, `:week`, `:day`, `:hour`, `:minute`, `:second`, `:microsecond`.

-  If the datetime is in the `"Etc/UTC"` time zone, this function
-  always succeeds without consulting the `time_zone_database`.
-
  This operation is equivalent to shifting the datetime wall clock
  (in other words, the value as someone in that timezone would see
  on their watch), then applying the time zone offset to convert it
  to UTC, and finally computing the new timezone in case of shifts.
  This ensures `shift/3` always returns a valid datetime.

-  Consequently, time zones that observe "Daylight Saving Time"
+  On the other hand, time zones that observe "Daylight Saving Time"
  or other changes, across summer/winter time will add/remove hours
  from the resulting datetime:

@@ -1793,27 +1700,16 @@ defmodule DateTime do
      DateTime.shift(dt, hour: 2)
      #=> #DateTime<2018-11-04 01:00:00-08:00 PST America/Los_Angeles>

-  Although the first example shows a difference of 2 hours when
-  comparing the wall clocks of the given datetime with the returned one,
-  due to the "spring forward" time jump, the actual elapsed time is
-  still exactly of 1 hour.
-
  In case you don't want these changes to happen automatically or you
  want to surface time zone conflicts to the user, you can shift
  the datetime as a naive datetime and then use `from_naive/2`:

      dt |> NaiveDateTime.shift(duration) |> DateTime.from_naive(dt.time_zone)

-  The above will surface time jumps and ambiguous datetimes, allowing you
-  to deal with them accordingly.
-
-  ## ISO calendar considerations
-
  When using the default ISO calendar, durations are collapsed and
  applied in the order of months, then seconds and microseconds:
-
-  * when shifting by 1 year and 2 months the date is actually shifted by 14 months
-  * weeks, days and smaller units are collapsed into seconds and microseconds
+  - when shifting by 1 year and 2 months the date is actually shifted by 14 months
+  - weeks, days and smaller units are collapsed into seconds and microseconds

  When shifting by month, days are rounded down to the nearest valid date.

@@ -1843,6 +1739,44 @@ defmodule DateTime do
  @spec shift(Calendar.datetime(), Duration.duration(), Calendar.time_zone_database()) :: t
  def shift(datetime, duration, time_zone_database \\ Calendar.get_time_zone_database())

+  def shift(%{calendar: calendar, time_zone: "Etc/UTC"} = datetime, duration, _time_zone_database) do
+    %{
+      year: year,
+      month: month,
+      day: day,
+      hour: hour,
+      minute: minute,
+      second: second,
+      microsecond: microsecond
+    } = datetime
+
+    {year, month, day, hour, minute, second, microsecond} =
+      calendar.shift_naive_datetime(
+        year,
+        month,
+        day,
+        hour,
+        minute,
+        second,
+        microsecond,
+        __duration__!(duration)
+      )
+
+    %DateTime{
+      year: year,
+      month: month,
+      day: day,
+      hour: hour,
+      minute: minute,
+      second: second,
+      microsecond: microsecond,
+      time_zone: "Etc/UTC",
+      zone_abbr: "UTC",
+      std_offset: 0,
+      utc_offset: 0
+    }
+  end
+
  def shift(%{calendar: calendar} = datetime, duration, time_zone_database) do
    %{
      year: year,
@@ -1936,7 +1870,7 @@ defmodule DateTime do
  ## Examples

  Imagine someone implements `Calendar.Holocene`, a calendar based on the
-  Gregorian calendar that adds exactly 10 000 years to the current Gregorian
+  Gregorian calendar that adds exactly 10,000 years to the current Gregorian
  year:

      iex> dt1 = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "AMT",
@@ -1965,7 +1899,7 @@ defmodule DateTime do
    if Calendar.compatible_calendars?(dt_calendar, calendar) do
      result_datetime =
        datetime
-        |> to_iso_days()
+        |> to_iso_days
        |> from_iso_days(datetime, calendar, precision)

      {:ok, result_datetime}
@@ -1983,7 +1917,7 @@ defmodule DateTime do
  ## Examples

  Imagine someone implements `Calendar.Holocene`, a calendar based on the
-  Gregorian calendar that adds exactly 10 000 years to the current Gregorian
+  Gregorian calendar that adds exactly 10,000 years to the current Gregorian
  year:

      iex> dt1 = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "AMT",
@@ -2053,12 +1987,11 @@ defmodule DateTime do
  end

  defp apply_tz_offset(iso_days, offset) do
-    Calendar.ISO.add_time_unit_to_iso_days(iso_days, -offset, :second)
+    Calendar.ISO.add_day_fraction_to_iso_days(iso_days, -offset, 86400)
  end

  defp from_map(%{} = datetime_map) do
    %DateTime{
-      calendar: datetime_map.calendar,
      year: datetime_map.year,
      month: datetime_map.month,
      day: datetime_map.day,
@@ -2145,8 +2078,7 @@ defmodule DateTime do
        )

      case datetime do
-        %{utc_offset: 0, std_offset: 0, time_zone: "Etc/UTC", year: year}
-        when calendar != Calendar.ISO or year in -9999..9999 ->
+        %{utc_offset: 0, std_offset: 0, time_zone: "Etc/UTC"} ->
          "~U[" <> formatted <> suffix(calendar) <> "]"

        _ ->
@@ -1,6 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-
 defmodule Duration do
  @moduledoc """
  Struct and functions for handling durations.
@@ -29,7 +26,7 @@ defmodule Duration do
      iex> Date.shift(~D[2016-01-03], Duration.new!(month: 2))
      ~D[2016-03-03]

-  It is important to note that shifting is not an arithmetic operation.
+  It is important to notice that shifting is not an arithmetic operation.
  For example, adding `date + 1 month + 1 month` does not yield the same
  result as `date + 2 months`. Let's see an example:

@@ -49,19 +46,9 @@ defmodule Duration do
    * larger units (such as years and months) are applied before
      smaller ones (such as weeks, hours, days, and so on)

-    * units are collapsed into months (`:year` and `:month`),
-      seconds (`:week`, `:day`, `:hour`, `:minute`, `:second`)
-      and microseconds (`:microsecond`) before they are applied
-
-    * 1 year is equivalent to 12 months, 1 week is equivalent to 7 days.
-      Therefore, 4 weeks _are not_ equivalent to 1 month
-
    * in case of non-existing dates, the results are rounded down to the
      nearest valid date

-  As the `shift/2` functions are calendar aware, they are guaranteed to return
-  valid date/times, considering leap years as well as DST in applicable time zones.
-
  ## Intervals

  Durations in Elixir can be combined with stream operations to build intervals.
@@ -72,7 +59,7 @@ defmodule Duration do

  However, once again, it is important to remember that shifting a duration is not
  arithmetic, so you may want to use the functions in this module depending on what
-  you want to achieve. Compare the results of both examples below:
+  you to achieve. Compare the results of both examples below:

      # Adding one month after the other
      iex> date = ~D[2016-01-31]
@@ -91,30 +78,6 @@ defmodule Duration do
  The second example consistently points to the last day of the month,
  as it performs operations on the duration, rather than shifting date
  after date.
-
-  ## Comparing durations
-
-  In order to accurately compare durations, you need to either compare
-  only certain fields or use a reference time instant. This is because
-  some fields are relative to others. For example, you may say that
-  1 month is the same as 30 days, but if you add both of these durations
-  to `~D[2015-02-01]`, you would get different results, as that month
-  has only 28 days.
-
-  Therefore, if you wish to compare durations, one option is to use
-  `Date.shift/2` (or `DateTime.shift/2` or similar), and then compare
-  the dates:
-
-      iex> date = ~D[2015-02-01]
-      iex> Date.compare(Date.shift(date, month: 1), Date.shift(date, day: 30))
-      :lt
-
-  Or alternatively convert the durations to a fixed unit by using `to_timeout/1`,
-  which supports durations only up to weeks, raising if it has the month or year
-  fields set.
-
-      iex> to_timeout(hour: 24) == to_timeout(day: 1)
-      true
  """

  @moduledoc since: "1.17.0"
@@ -129,16 +92,6 @@ defmodule Duration do
            second: 0,
            microsecond: {0, 0}

-  @typedoc """
-  The microsecond component of a duration.
-
-  Unlike `t:Calendar.microsecond/0`, the value may be negative, as
-  durations may represent negative amounts of time. The precision is
-  an integer from 0 to 6 holding the number of significant digits,
-  as in the calendar types.
-  """
-  @type microsecond :: {value :: integer, precision :: 0..6}
-
  @typedoc """
  The duration struct type.
  """
@@ -150,7 +103,7 @@ defmodule Duration do
          hour: integer,
          minute: integer,
          second: integer,
-          microsecond: microsecond()
+          microsecond: {integer, 0..6}
        }

  @typedoc """
@@ -164,31 +117,13 @@ defmodule Duration do
          | {:hour, integer}
          | {:minute, integer}
          | {:second, integer}
-          | {:microsecond, microsecond()}
+          | {:microsecond, {integer, 0..6}}

  @typedoc """
  The duration type specifies a `%Duration{}` struct or a keyword list of valid duration unit pairs.
  """
  @type duration :: t | [unit_pair]

-  @typedoc """
-  Options for `Duration.to_string/2`.
-  """
-  @type to_string_opts :: [
-          units: [
-            year: String.t(),
-            month: String.t(),
-            week: String.t(),
-            day: String.t(),
-            hour: String.t(),
-            minute: String.t(),
-            second: String.t()
-          ],
-          separator: String.t()
-        ]
-
-  @microseconds_per_second 1_000_000
-
  @doc """
  Creates a new `Duration` struct from given `unit_pairs`.

@@ -242,60 +177,60 @@ defmodule Duration do
  @doc """
  Adds units of given durations `d1` and `d2`.

-  Respects the highest microsecond precision of the two.
+  Respects the the highest microsecond precision of the two.

  ## Examples

-      iex> Duration.add(Duration.new!(week: 2, day: 1), Duration.new!(day: 2))
+      iex> Duration.add(%Duration{week: 2, day: 1}, %Duration{day: 2})
      %Duration{week: 2, day: 3}
-      iex> Duration.add(Duration.new!(microsecond: {400, 3}), Duration.new!(microsecond: {600, 6}))
+      iex> Duration.add(%Duration{microsecond: {400, 3}}, %Duration{microsecond: {600, 6}})
      %Duration{microsecond: {1000, 6}}

  """
  @spec add(t, t) :: t
-  def add(%Duration{microsecond: {ms1, p1}} = d1, %Duration{microsecond: {ms2, p2}} = d2) do
-    %{year: y1, month: mo1, week: w1, day: day1, hour: h1, minute: mi1, second: s1} = d1
-    %{year: y2, month: mo2, week: w2, day: day2, hour: h2, minute: mi2, second: s2} = d2
+  def add(%Duration{} = d1, %Duration{} = d2) do
+    {m1, p1} = d1.microsecond
+    {m2, p2} = d2.microsecond

    %Duration{
-      year: y1 + y2,
-      month: mo1 + mo2,
-      week: w1 + w2,
-      day: day1 + day2,
-      hour: h1 + h2,
-      minute: mi1 + mi2,
-      second: s1 + s2,
-      microsecond: {ms1 + ms2, max(p1, p2)}
+      year: d1.year + d2.year,
+      month: d1.month + d2.month,
+      week: d1.week + d2.week,
+      day: d1.day + d2.day,
+      hour: d1.hour + d2.hour,
+      minute: d1.minute + d2.minute,
+      second: d1.second + d2.second,
+      microsecond: {m1 + m2, max(p1, p2)}
    }
  end

  @doc """
  Subtracts units of given durations `d1` and `d2`.

-  Respects the highest microsecond precision of the two.
+  Respects the the highest microsecond precision of the two.

  ## Examples

-      iex> Duration.subtract(Duration.new!(week: 2, day: 1), Duration.new!(day: 2))
+      iex> Duration.subtract(%Duration{week: 2, day: 1}, %Duration{day: 2})
      %Duration{week: 2, day: -1}
-      iex> Duration.subtract(Duration.new!(microsecond: {400, 6}), Duration.new!(microsecond: {600, 3}))
+      iex> Duration.subtract(%Duration{microsecond: {400, 6}}, %Duration{microsecond: {600, 3}})
      %Duration{microsecond: {-200, 6}}

  """
  @spec subtract(t, t) :: t
-  def subtract(%Duration{microsecond: {ms1, p1}} = d1, %Duration{microsecond: {ms2, p2}} = d2) do
-    %{year: y1, month: mo1, week: w1, day: day1, hour: h1, minute: mi1, second: s1} = d1
-    %{year: y2, month: mo2, week: w2, day: day2, hour: h2, minute: mi2, second: s2} = d2
+  def subtract(%Duration{} = d1, %Duration{} = d2) do
+    {m1, p1} = d1.microsecond
+    {m2, p2} = d2.microsecond

    %Duration{
-      year: y1 - y2,
-      month: mo1 - mo2,
-      week: w1 - w2,
-      day: day1 - day2,
-      hour: h1 - h2,
-      minute: mi1 - mi2,
-      second: s1 - s2,
-      microsecond: {ms1 - ms2, max(p1, p2)}
+      year: d1.year - d2.year,
+      month: d1.month - d2.month,
+      week: d1.week - d2.week,
+      day: d1.day - d2.day,
+      hour: d1.hour - d2.hour,
+      minute: d1.minute - d2.minute,
+      second: d1.second - d2.second,
+      microsecond: {m1 - m2, max(p1, p2)}
    }
  end

@@ -304,24 +239,22 @@ defmodule Duration do

  ## Examples

-      iex> Duration.multiply(Duration.new!(day: 1, minute: 15, second: -10), 3)
+      iex> Duration.multiply(%Duration{day: 1, minute: 15, second: -10}, 3)
      %Duration{day: 3, minute: 45, second: -30}
-      iex> Duration.multiply(Duration.new!(microsecond: {200, 4}), 3)
+      iex> Duration.multiply(%Duration{microsecond: {200, 4}}, 3)
      %Duration{microsecond: {600, 4}}

  """
  @spec multiply(t, integer) :: t
  def multiply(%Duration{microsecond: {ms, p}} = duration, integer) when is_integer(integer) do
-    %{year: y, month: mo, week: w, day: d, hour: h, minute: mi, second: s} = duration
-
    %Duration{
-      year: y * integer,
-      month: mo * integer,
-      week: w * integer,
-      day: d * integer,
-      hour: h * integer,
-      minute: mi * integer,
-      second: s * integer,
+      year: duration.year * integer,
+      month: duration.month * integer,
+      week: duration.week * integer,
+      day: duration.day * integer,
+      hour: duration.hour * integer,
+      minute: duration.minute * integer,
+      second: duration.second * integer,
      microsecond: {ms * integer, p}
    }
  end
@@ -331,270 +264,23 @@ defmodule Duration do

  ## Examples

-      iex> Duration.negate(Duration.new!(day: 1, minute: 15, second: -10))
+      iex> Duration.negate(%Duration{day: 1, minute: 15, second: -10})
      %Duration{day: -1, minute: -15, second: 10}
-      iex> Duration.negate(Duration.new!(microsecond: {500000, 4}))
+      iex> Duration.negate(%Duration{microsecond: {500000, 4}})
      %Duration{microsecond: {-500000, 4}}

  """
  @spec negate(t) :: t
  def negate(%Duration{microsecond: {ms, p}} = duration) do
-    %{year: y, month: mo, week: w, day: d, hour: h, minute: mi, second: s} = duration
-
    %Duration{
-      year: -y,
-      month: -mo,
-      week: -w,
-      day: -d,
-      hour: -h,
-      minute: -mi,
-      second: -s,
+      year: -duration.year,
+      month: -duration.month,
+      week: -duration.week,
+      day: -duration.day,
+      hour: -duration.hour,
+      minute: -duration.minute,
+      second: -duration.second,
      microsecond: {-ms, p}
    }
  end
-
-  @doc """
-  Parses an [ISO 8601](https://en.wikipedia.org/wiki/ISO_8601#Durations) formatted duration string to a `Duration` struct.
-
-  Duration strings, as well as individual units, may be prefixed with plus/minus signs so that:
-
-  - `-PT6H3M` parses as `%Duration{hour: -6, minute: -3}`
-  - `-PT6H-3M` parses as `%Duration{hour: -6, minute: 3}`
-  - `+PT6H3M` parses as `%Duration{hour: 6, minute: 3}`
-  - `+PT6H-3M` parses as `%Duration{hour: 6, minute: -3}`
-
-  Duration designators must be provided in order of magnitude: `P[n]Y[n]M[n]W[n]DT[n]H[n]M[n]S`.
-
-  Only seconds may be specified with a decimal fraction, using either a comma or a full stop: `P1DT4,5S`.
-
-  ## Examples
-
-      iex> Duration.from_iso8601("P1Y2M3DT4H5M6S")
-      {:ok, %Duration{year: 1, month: 2, day: 3, hour: 4, minute: 5, second: 6}}
-      iex> Duration.from_iso8601("P3Y-2MT3H")
-      {:ok, %Duration{year: 3, month: -2, hour: 3}}
-      iex> Duration.from_iso8601("-PT10H-30M")
-      {:ok, %Duration{hour: -10, minute: 30}}
-      iex> Duration.from_iso8601("PT4.650S")
-      {:ok, %Duration{second: 4, microsecond: {650000, 3}}}
-
-  """
-  @spec from_iso8601(String.t()) :: {:ok, t} | {:error, atom}
-  def from_iso8601(string) when is_binary(string) do
-    case Calendar.ISO.parse_duration(string) do
-      {:ok, duration} ->
-        {:ok, new!(duration)}
-
-      error ->
-        error
-    end
-  end
-
-  @doc """
-  Same as `from_iso8601/1` but raises an `ArgumentError`.
-
-  ## Examples
-
-      iex> Duration.from_iso8601!("P1Y2M3DT4H5M6S")
-      %Duration{year: 1, month: 2, day: 3, hour: 4, minute: 5, second: 6}
-      iex> Duration.from_iso8601!("P10D")
-      %Duration{day: 10}
-
-  """
-  @spec from_iso8601!(String.t()) :: t
-  def from_iso8601!(string) when is_binary(string) do
-    case from_iso8601(string) do
-      {:ok, duration} ->
-        duration
-
-      {:error, reason} ->
-        raise ArgumentError, ~s/failed to parse duration "#{string}". reason: #{inspect(reason)}/
-    end
-  end
-
-  @doc """
-  Converts the given `duration` to a human readable representation.
-
-  ## Options
-
-    * `:units` - the units to be used alongside each duration component.
-      The default units follow the ISO 80000-3 standard:
-
-          [
-            year: "a",
-            month: "mo",
-            week: "wk",
-            day: "d",
-            hour: "h",
-            minute: "min",
-            second: "s"
-          ]
-
-    * `:separator` - a string used to separate the distinct components. Defaults to `" "`.
-
-  ## Examples
-
-      iex> Duration.to_string(Duration.new!(second: 30))
-      "30s"
-      iex> Duration.to_string(Duration.new!(day: 40, hour: 12, minute: 42, second: 12))
-      "40d 12h 42min 12s"
-
-  By default, this function uses ISO 80000-3 units, which uses "a" for years.
-  But you can customize all units via the units option:
-
-      iex> Duration.to_string(Duration.new!(year: 3))
-      "3a"
-      iex> Duration.to_string(Duration.new!(year: 3), units: [year: "y"])
-      "3y"
-
-  You may also choose the separator:
-
-      iex> Duration.to_string(Duration.new!(day: 40, hour: 12, minute: 42, second: 12), separator: ", ")
-      "40d, 12h, 42min, 12s"
-
-  A duration without components is rendered as "0s":
-
-      iex> Duration.to_string(Duration.new!([]))
-      "0s"
-
-  Microseconds are rendered as part of seconds with the appropriate precision:
-
-      iex> Duration.to_string(Duration.new!(second: 1, microsecond: {2_200, 3}))
-      "1.002s"
-      iex> Duration.to_string(Duration.new!(second: 1, microsecond: {-1_200_000, 4}))
-      "-0.2000s"
-
-  """
-  @doc since: "1.18.0"
-  @spec to_string(t, to_string_opts) :: String.t()
-  def to_string(%Duration{} = duration, opts \\ []) do
-    units = Keyword.get(opts, :units, [])
-    separator = Keyword.get(opts, :separator, " ")
-
-    case to_string_year(duration, [], units) do
-      [] ->
-        "0" <> Keyword.get(units, :second, "s")
-
-      [part] ->
-        IO.iodata_to_binary(part)
-
-      parts ->
-        parts |> Enum.reduce(&[&1, separator | &2]) |> IO.iodata_to_binary()
-    end
-  end
-
-  defp to_string_part(0, _units, _key, _default, acc),
-    do: acc
-
-  defp to_string_part(x, units, key, default, acc),
-    do: [[Integer.to_string(x) | Keyword.get(units, key, default)] | acc]
-
-  defp to_string_year(%{year: year} = duration, acc, units) do
-    to_string_month(duration, to_string_part(year, units, :year, "a", acc), units)
-  end
-
-  defp to_string_month(%{month: month} = duration, acc, units) do
-    to_string_week(duration, to_string_part(month, units, :month, "mo", acc), units)
-  end
-
-  defp to_string_week(%{week: week} = duration, acc, units) do
-    to_string_day(duration, to_string_part(week, units, :week, "wk", acc), units)
-  end
-
-  defp to_string_day(%{day: day} = duration, acc, units) do
-    to_string_hour(duration, to_string_part(day, units, :day, "d", acc), units)
-  end
-
-  defp to_string_hour(%{hour: hour} = duration, acc, units) do
-    to_string_minute(duration, to_string_part(hour, units, :hour, "h", acc), units)
-  end
-
-  defp to_string_minute(%{minute: minute} = duration, acc, units) do
-    to_string_second(duration, to_string_part(minute, units, :minute, "min", acc), units)
-  end
-
-  defp to_string_second(%{second: 0, microsecond: {0, _}}, acc, _units) do
-    acc
-  end
-
-  defp to_string_second(%{second: s, microsecond: {ms, p}}, acc, units) do
-    [[second_component(s, ms, p) | Keyword.get(units, :second, "s")] | acc]
-  end
-
-  @doc """
-  Converts the given `duration` to an [ISO 8601-2:2019](https://en.wikipedia.org/wiki/ISO_8601) formatted string.
-
-  This function implements the extension of ISO 8601:2019, allowing weeks to appear between months and days: `P3M3W3D`.
-
-  ## Examples
-
-      iex> Duration.to_iso8601(Duration.new!(year: 3))
-      "P3Y"
-      iex> Duration.to_iso8601(Duration.new!(day: 40, hour: 12, minute: 42, second: 12))
-      "P40DT12H42M12S"
-      iex> Duration.to_iso8601(Duration.new!(second: 30))
-      "PT30S"
-
-      iex> Duration.to_iso8601(Duration.new!([]))
-      "PT0S"
-
-      iex> Duration.to_iso8601(Duration.new!(second: 1, microsecond: {2_200, 3}))
-      "PT1.002S"
-      iex> Duration.to_iso8601(Duration.new!(second: 1, microsecond: {-1_200_000, 4}))
-      "PT-0.2000S"
-  """
-
-  @spec to_iso8601(t) :: String.t()
-  def to_iso8601(%Duration{} = duration) do
-    case {to_iso8601_duration_date(duration), to_iso8601_duration_time(duration)} do
-      {[], []} -> "PT0S"
-      {date, time} -> IO.iodata_to_binary([?P, date, time])
-    end
-  end
-
-  defp to_iso8601_duration_date(%{year: 0, month: 0, week: 0, day: 0}) do
-    []
-  end
-
-  defp to_iso8601_duration_date(%{year: year, month: month, week: week, day: day}) do
-    [pair(year, ?Y), pair(month, ?M), pair(week, ?W), pair(day, ?D)]
-  end
-
-  defp to_iso8601_duration_time(%{hour: 0, minute: 0, second: 0, microsecond: {0, _}}) do
-    []
-  end
-
-  defp to_iso8601_duration_time(%{hour: hour, minute: minute} = d) do
-    [?T, pair(hour, ?H), pair(minute, ?M), second_component(d)]
-  end
-
-  defp second_component(%{second: 0, microsecond: {0, _}}) do
-    []
-  end
-
-  defp second_component(%{second: second, microsecond: {ms, p}}) do
-    [second_component(second, ms, p), ?S]
-  end
-
-  defp second_component(second, _ms, 0) do
-    Integer.to_string(second)
-  end
-
-  defp second_component(second, ms, p) do
-    total_ms = second * @microseconds_per_second + ms
-    second = total_ms |> div(@microseconds_per_second) |> abs()
-    ms = total_ms |> rem(@microseconds_per_second) |> abs()
-    sign = if total_ms < 0, do: ?-, else: []
-
-    [
-      sign,
-      Integer.to_string(second),
-      ?.,
-      Calendar.ISO.microseconds_to_iodata(ms, p)
-    ]
-  end
-
-  @compile {:inline, pair: 2}
-  defp pair(0, _key), do: []
-  defp pair(num, key), do: [Integer.to_string(num), key]
 end
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule NaiveDateTime do
  @moduledoc """
  A NaiveDateTime struct (without a time zone) and functions.
@@ -40,10 +36,10 @@ 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`, `after?/2` and `before?/2` functions.
-  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:
+  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]
@@ -114,12 +110,30 @@ defmodule NaiveDateTime do
  @spec utc_now(Calendar.calendar() | :native | :microsecond | :millisecond | :second) :: t
  def utc_now(calendar_or_time_unit \\ Calendar.ISO)

+  def utc_now(Calendar.ISO) do
+    {:ok, {year, month, day}, {hour, minute, second}, microsecond} =
+      Calendar.ISO.from_unix(:os.system_time(), :native)
+
+    %NaiveDateTime{
+      year: year,
+      month: month,
+      day: day,
+      hour: hour,
+      minute: minute,
+      second: second,
+      microsecond: microsecond,
+      calendar: Calendar.ISO
+    }
+  end
+
  def utc_now(time_unit) when time_unit in [:microsecond, :millisecond, :second, :native] do
    utc_now(time_unit, Calendar.ISO)
  end

  def utc_now(calendar) do
-    utc_now(:native, calendar)
+    calendar
+    |> DateTime.utc_now()
+    |> DateTime.to_naive()
  end

  @doc """
@@ -144,27 +158,14 @@ defmodule NaiveDateTime do
  @spec utc_now(:native | :microsecond | :millisecond | :second, Calendar.calendar()) :: t
  def utc_now(time_unit, calendar)
      when time_unit in [:native, :microsecond, :millisecond, :second] do
-    {:ok, {year, month, day}, {hour, minute, second}, microsecond} =
-      Calendar.ISO.from_unix(System.os_time(time_unit), time_unit)
-
-    %NaiveDateTime{
-      year: year,
-      month: month,
-      day: day,
-      hour: hour,
-      minute: minute,
-      second: second,
-      microsecond: microsecond,
-      calendar: Calendar.ISO
-    }
-    |> convert!(calendar)
+    DateTime.utc_now(time_unit, calendar) |> DateTime.to_naive()
  end

  @doc """
  Returns the "local time" for the machine the Elixir program is running on.

  WARNING: This function can cause insidious bugs. It depends on the time zone
-  configuration at run time. This can change and be set to a time zone that has
+  configuration at run time. This can changed and be set to a time zone that has
  daylight saving jumps (spring forward or fall back).

  This function can be used to display what the time is right now for the time
@@ -251,7 +252,7 @@ defmodule NaiveDateTime do
          Calendar.hour(),
          Calendar.minute(),
          Calendar.second(),
-          Calendar.microsecond() | non_neg_integer(),
+          Calendar.microsecond() | non_neg_integer,
          Calendar.calendar()
        ) :: {:ok, t} | {:error, atom}
  def new(year, month, day, hour, minute, second, microsecond \\ {0, 0}, calendar \\ Calendar.ISO)
@@ -316,7 +317,7 @@ defmodule NaiveDateTime do
          Calendar.hour(),
          Calendar.minute(),
          Calendar.second(),
-          Calendar.microsecond() | non_neg_integer(),
+          Calendar.microsecond() | non_neg_integer,
          Calendar.calendar()
        ) :: t
  def new!(
@@ -391,20 +392,13 @@ defmodule NaiveDateTime do
  @doc """
  Adds a specified amount of time to a `NaiveDateTime`.

-  > #### Prefer `shift/2` {: .info}
-  >
-  > Prefer `shift/2` over `add/3`, as it offers a more ergonomic API.
-  >
-  > `add/3` provides a lower-level API which only supports fixed units
-  > such as `:hour` and `:second`, but not `:month` (as the exact length
-  > of a month depends on the current month). `add/3` always considers
-  > the unit to be computed according to the `Calendar.ISO`.
-
  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` for convenience but ultimately they are
-  all converted to microseconds. Negative values will move backwards
-  in time and the default precision is `:second`.
+  `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`.

  ## Examples

@@ -454,6 +448,8 @@ defmodule NaiveDateTime do
      iex> NaiveDateTime.add(dt, 21, :second)
      ~N[2000-02-29 23:00:28]

+  To shift a naive datetime by a `Duration` and according to its underlying calendar, use `NaiveDateTime.shift/2`.
+
  """
  @doc since: "1.4.0"
  @spec add(Calendar.naive_datetime(), integer, :day | :hour | :minute | System.time_unit()) :: t
@@ -541,15 +537,15 @@ defmodule NaiveDateTime do
  def diff(naive_datetime1, naive_datetime2, unit \\ :second)

  def diff(naive_datetime1, naive_datetime2, :day) do
-    diff(naive_datetime1, naive_datetime2, :microsecond) |> div(86_400_000_000)
+    diff(naive_datetime1, naive_datetime2, :second) |> div(86400)
  end

  def diff(naive_datetime1, naive_datetime2, :hour) do
-    diff(naive_datetime1, naive_datetime2, :microsecond) |> div(3_600_000_000)
+    diff(naive_datetime1, naive_datetime2, :second) |> div(3600)
  end

  def diff(naive_datetime1, naive_datetime2, :minute) do
-    diff(naive_datetime1, naive_datetime2, :microsecond) |> div(60_000_000)
+    diff(naive_datetime1, naive_datetime2, :second) |> div(60)
  end

  def diff(
@@ -570,11 +566,9 @@ defmodule NaiveDateTime do
            "unsupported time unit. Expected :day, :hour, :minute, :second, :millisecond, :microsecond, :nanosecond, or a positive integer, got #{inspect(unit)}"
    end

-    diff_microsecond =
-      (naive_datetime1 |> to_iso_days() |> Calendar.ISO.iso_days_to_unit(:microsecond)) -
-        (naive_datetime2 |> to_iso_days() |> Calendar.ISO.iso_days_to_unit(:microsecond))
-
-    System.convert_time_unit(diff_microsecond, :microsecond, unit)
+    units1 = naive_datetime1 |> to_iso_days() |> Calendar.ISO.iso_days_to_unit(unit)
+    units2 = naive_datetime2 |> to_iso_days() |> Calendar.ISO.iso_days_to_unit(unit)
+    units1 - units2
  end

  @doc """
@@ -584,9 +578,8 @@ defmodule NaiveDateTime do

  When using the default ISO calendar, durations are collapsed and
  applied in the order of months, then seconds and microseconds:
-
-  * when shifting by 1 year and 2 months the date is actually shifted by 14 months
-  * weeks, days and smaller units are collapsed into seconds and microseconds
+  - when shifting by 1 year and 2 months the date is actually shifted by 14 months
+  - weeks, days and smaller units are collapsed into seconds and microseconds

  When shifting by month, days are rounded down to the nearest valid date.

@@ -674,7 +667,7 @@ defmodule NaiveDateTime do

  """
  @doc since: "1.6.0"
-  @spec truncate(Calendar.naive_datetime(), :microsecond | :millisecond | :second) :: t()
+  @spec truncate(t(), :microsecond | :millisecond | :second) :: t()
  def truncate(%NaiveDateTime{microsecond: microsecond} = naive_datetime, precision) do
    %{naive_datetime | microsecond: Calendar.truncate(microsecond, precision)}
  end
@@ -717,18 +710,16 @@ defmodule NaiveDateTime do

  """
  @spec to_date(Calendar.naive_datetime()) :: Date.t()
-  def to_date(
-        %{
-          year: year,
-          month: month,
-          day: day,
-          calendar: calendar,
-          hour: _,
-          minute: _,
-          second: _,
-          microsecond: _
-        } = _naive_datetime
-      ) do
+  def to_date(%{
+        year: year,
+        month: month,
+        day: day,
+        calendar: calendar,
+        hour: _,
+        minute: _,
+        second: _,
+        microsecond: _
+      }) do
    %Date{year: year, month: month, day: day, calendar: calendar}
  end

@@ -745,18 +736,16 @@ defmodule NaiveDateTime do

  """
  @spec to_time(Calendar.naive_datetime()) :: Time.t()
-  def to_time(
-        %{
-          year: _,
-          month: _,
-          day: _,
-          calendar: calendar,
-          hour: hour,
-          minute: minute,
-          second: second,
-          microsecond: microsecond
-        } = _naive_datetime
-      ) do
+  def to_time(%{
+        year: _,
+        month: _,
+        day: _,
+        calendar: calendar,
+        hour: hour,
+        minute: minute,
+        second: second,
+        microsecond: microsecond
+      }) do
    %Time{
      hour: hour,
      minute: minute,
@@ -769,10 +758,7 @@ defmodule NaiveDateTime do
  @doc """
  Converts the given naive datetime to a string according to its calendar.

-  For readability, this function follows the RFC3339 suggestion of removing
-  the "T" separator between the date and time components.
-
-  ## Examples
+  ### Examples

      iex> NaiveDateTime.to_string(~N[2000-02-28 23:00:13])
      "2000-02-28 23:00:13"
@@ -919,7 +905,7 @@ defmodule NaiveDateTime do
  Only supports converting naive datetimes which are in the ISO calendar,
  attempting to convert naive datetimes from other calendars will raise.

-  ## Examples
+  ### Examples

      iex> NaiveDateTime.to_iso8601(~N[2000-02-28 23:00:13])
      "2000-02-28T23:00:13"
@@ -945,19 +931,6 @@ defmodule NaiveDateTime do

  def to_iso8601(%{calendar: Calendar.ISO} = naive_datetime, format)
      when format in [:basic, :extended] do
-    naive_datetime
-    |> to_iso8601_iodata(format)
-    |> IO.iodata_to_binary()
-  end
-
-  def to_iso8601(%{calendar: _} = naive_datetime, format)
-      when format in [:basic, :extended] do
-    naive_datetime
-    |> convert!(Calendar.ISO)
-    |> to_iso8601(format)
-  end
-
-  defp to_iso8601_iodata(naive_datetime, format) do
    %{
      year: year,
      month: month,
@@ -968,11 +941,14 @@ defmodule NaiveDateTime do
      microsecond: microsecond
    } = naive_datetime

-    [
-      Calendar.ISO.date_to_iodata(year, month, day, format),
-      ?T,
-      Calendar.ISO.time_to_iodata(hour, minute, second, microsecond, format)
-    ]
+    Calendar.ISO.date_to_string(year, month, day, format) <>
+      "T" <> Calendar.ISO.time_to_string(hour, minute, second, microsecond, format)
+  end
+
+  def to_iso8601(%{calendar: _} = naive_datetime, format) when format in [:basic, :extended] do
+    naive_datetime
+    |> convert!(Calendar.ISO)
+    |> to_iso8601(format)
  end

  @doc """
@@ -1016,8 +992,6 @@ defmodule NaiveDateTime do

      iex> NaiveDateTime.from_erl({{2000, 1, 1}, {13, 30, 15}})
      {:ok, ~N[2000-01-01 13:30:15]}
-      iex> NaiveDateTime.from_erl({{2000, 1, 1}, {13, 30, 15}}, 5000)
-      {:ok, ~N[2000-01-01 13:30:15.005000]}
      iex> NaiveDateTime.from_erl({{2000, 1, 1}, {13, 30, 15}}, {5000, 3})
      {:ok, ~N[2000-01-01 13:30:15.005]}
      iex> NaiveDateTime.from_erl({{2000, 13, 1}, {13, 30, 15}})
@@ -1026,11 +1000,7 @@ defmodule NaiveDateTime do
      {:error, :invalid_date}

  """
-  @spec from_erl(
-          :calendar.datetime(),
-          Calendar.microsecond() | non_neg_integer(),
-          Calendar.calendar()
-        ) ::
+  @spec from_erl(:calendar.datetime(), Calendar.microsecond(), Calendar.calendar()) ::
          {:ok, t} | {:error, atom}
  def from_erl(tuple, microsecond \\ {0, 0}, calendar \\ Calendar.ISO)

@@ -1049,19 +1019,13 @@ defmodule NaiveDateTime do

      iex> NaiveDateTime.from_erl!({{2000, 1, 1}, {13, 30, 15}})
      ~N[2000-01-01 13:30:15]
-      iex> NaiveDateTime.from_erl!({{2000, 1, 1}, {13, 30, 15}}, 5000)
-      ~N[2000-01-01 13:30:15.005000]
      iex> NaiveDateTime.from_erl!({{2000, 1, 1}, {13, 30, 15}}, {5000, 3})
      ~N[2000-01-01 13:30:15.005]
      iex> NaiveDateTime.from_erl!({{2000, 13, 1}, {13, 30, 15}})
      ** (ArgumentError) cannot convert {{2000, 13, 1}, {13, 30, 15}} to naive datetime, reason: :invalid_date

  """
-  @spec from_erl!(
-          :calendar.datetime(),
-          Calendar.microsecond() | non_neg_integer(),
-          Calendar.calendar()
-        ) :: t
+  @spec from_erl!(:calendar.datetime(), Calendar.microsecond(), Calendar.calendar()) :: t
  def from_erl!(tuple, microsecond \\ {0, 0}, calendar \\ Calendar.ISO) do
    case from_erl(tuple, microsecond, calendar) do
      {:ok, value} ->
@@ -1152,18 +1116,16 @@ defmodule NaiveDateTime do
  """
  @doc since: "1.11.0"
  @spec to_gregorian_seconds(Calendar.naive_datetime()) :: {integer(), non_neg_integer()}
-  def to_gregorian_seconds(
-        %{
-          calendar: calendar,
-          year: year,
-          month: month,
-          day: day,
-          hour: hour,
-          minute: minute,
-          second: second,
-          microsecond: {microsecond, precision}
-        } = _naive_datetime
-      ) do
+  def to_gregorian_seconds(%{
+        calendar: calendar,
+        year: year,
+        month: month,
+        day: day,
+        hour: hour,
+        minute: minute,
+        second: second,
+        microsecond: {microsecond, precision}
+      }) do
    {days, day_fraction} =
      calendar.naive_datetime_to_iso_days(
        year,
@@ -1274,7 +1236,7 @@ defmodule NaiveDateTime do
  ## Examples

  Imagine someone implements `Calendar.Holocene`, a calendar based on the
-  Gregorian calendar that adds exactly 10 000 years to the current Gregorian
+  Gregorian calendar that adds exactly 10,000 years to the current Gregorian
  year:

      iex> NaiveDateTime.convert(~N[2000-01-01 13:30:15], Calendar.Holocene)
@@ -1287,10 +1249,6 @@ defmodule NaiveDateTime do
          {:ok, t} | {:error, :incompatible_calendars}

  # Keep it multiline for proper function clause errors.
-  def convert(%NaiveDateTime{calendar: calendar} = ndt, calendar) do
-    {:ok, ndt}
-  end
-
  def convert(
        %{
          calendar: calendar,
@@ -1322,7 +1280,7 @@ defmodule NaiveDateTime do
    if Calendar.compatible_calendars?(ndt_calendar, calendar) do
      result_naive_datetime =
        naive_datetime
-        |> to_iso_days()
+        |> to_iso_days
        |> from_iso_days(calendar, precision)

      {:ok, result_naive_datetime}
@@ -1340,7 +1298,7 @@ defmodule NaiveDateTime do
  ## Examples

  Imagine someone implements `Calendar.Holocene`, a calendar based on the
-  Gregorian calendar that adds exactly 10 000 years to the current Gregorian
+  Gregorian calendar that adds exactly 10,000 years to the current Gregorian
  year:

      iex> NaiveDateTime.convert!(~N[2000-01-01 13:30:15], Calendar.Holocene)
@@ -1492,15 +1450,10 @@ defmodule NaiveDateTime do
        calendar: calendar
      } = naive_datetime

-      if calendar != Calendar.ISO or year in -9999..9999 do
-        formatted =
-          calendar.naive_datetime_to_string(year, month, day, hour, minute, second, microsecond)
+      formatted =
+        calendar.naive_datetime_to_string(year, month, day, hour, minute, second, microsecond)

-        "~N[" <> formatted <> suffix(calendar) <> "]"
-      else
-        "NaiveDateTime.new!(#{Integer.to_string(year)}, #{Integer.to_string(month)}, #{Integer.to_string(day)}, " <>
-          "#{Integer.to_string(hour)}, #{Integer.to_string(minute)}, #{Integer.to_string(second)}, #{inspect(microsecond)})"
-      end
+      "~N[" <> formatted <> suffix(calendar) <> "]"
    end

    defp suffix(Calendar.ISO), do: ""
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule Time do
  @moduledoc """
  A Time struct and functions.
@@ -35,10 +31,9 @@ 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`, `after?/2` and `before?/2` functions.
-  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:
+  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]
@@ -60,52 +55,17 @@ defmodule Time do
  @doc """
  Returns the current time in UTC.

-  You can pass a time unit to automatically truncate the resulting time.
-
-  The default unit if none gets passed is `:native` which results in a default resolution of microseconds.
-
  ## Examples

      iex> time = Time.utc_now()
      iex> time.hour >= 0
      true

-      iex> time = Time.utc_now(:second)
-      iex> time.microsecond
-      {0, 0}
-
  """
  @doc since: "1.4.0"
-  @spec utc_now(Calendar.calendar() | :native | :microsecond | :millisecond | :second) :: t
-  def utc_now(calendar_or_time_unit \\ Calendar.ISO) do
-    case calendar_or_time_unit do
-      unit when unit in [:native, :microsecond, :millisecond, :second] ->
-        utc_now(unit, Calendar.ISO)
-
-      calendar ->
-        utc_now(:native, calendar)
-    end
-  end
-
-  @doc """
-  Returns the current time in UTC, supporting a precision and a specific calendar.
-
-  ## Examples
-
-      iex> time = Time.utc_now(:microsecond, Calendar.ISO)
-      iex> time.hour >= 0
-      true
-
-      iex> time = Time.utc_now(:second, Calendar.ISO)
-      iex> time.microsecond
-      {0, 0}
-
-  """
-  @doc since: "1.19.0"
-  @spec utc_now(:native | :microsecond | :millisecond | :second, Calendar.calendar()) :: t
-  def utc_now(time_unit, calendar)
-      when time_unit in [:native, :microsecond, :millisecond, :second] do
-    {:ok, _, time, microsecond} = Calendar.ISO.from_unix(System.os_time(time_unit), time_unit)
+  @spec utc_now(Calendar.calendar()) :: t
+  def utc_now(calendar \\ Calendar.ISO) do
+    {:ok, _, time, microsecond} = Calendar.ISO.from_unix(:os.system_time(), :native)
    {hour, minute, second} = time

    iso_time = %Time{
@@ -146,9 +106,8 @@ defmodule Time do
      iex> Time.new(23, 59, 59, 1_000_000)
      {:error, :invalid_time}

-  Invalid precision:
-
-      iex> Time.new(23, 59, 59, {999_999, 10})
+      # Invalid precision
+      Time.new(23, 59, 59, {999_999, 10})
      {:error, :invalid_time}

  """
@@ -156,7 +115,7 @@ defmodule Time do
          Calendar.hour(),
          Calendar.minute(),
          Calendar.second(),
-          Calendar.microsecond() | non_neg_integer(),
+          Calendar.microsecond() | non_neg_integer,
          Calendar.calendar()
        ) :: {:ok, t} | {:error, atom}
  def new(hour, minute, second, microsecond \\ {0, 0}, calendar \\ Calendar.ISO)
@@ -226,7 +185,7 @@ defmodule Time do
  @doc """
  Converts the given `time` to a string.

-  ## Examples
+  ### Examples

      iex> Time.to_string(~T[23:00:00])
      "23:00:00"
@@ -335,7 +294,7 @@ defmodule Time do
  format, for human readability. It also supports the "basic" format through
  passing the `:basic` option.

-  ## Examples
+  ### Examples

      iex> Time.to_iso8601(~T[23:00:13])
      "23:00:13"
@@ -396,21 +355,13 @@ defmodule Time do

  ## Examples

-      iex> Time.from_erl({23, 30, 15})
-      {:ok, ~T[23:30:15]}
-      iex> Time.from_erl({23, 30, 15}, 5000)
-      {:ok, ~T[23:30:15.005000]}
      iex> Time.from_erl({23, 30, 15}, {5000, 3})
      {:ok, ~T[23:30:15.005]}
      iex> Time.from_erl({24, 30, 15})
      {:error, :invalid_time}

  """
-  @spec from_erl(
-          :calendar.time(),
-          Calendar.microsecond() | non_neg_integer(),
-          Calendar.calendar()
-        ) ::
+  @spec from_erl(:calendar.time(), Calendar.microsecond(), Calendar.calendar()) ::
          {:ok, t} | {:error, atom}
  def from_erl(tuple, microsecond \\ {0, 0}, calendar \\ Calendar.ISO)

@@ -426,8 +377,6 @@ defmodule Time do

      iex> Time.from_erl!({23, 30, 15})
      ~T[23:30:15]
-      iex> Time.from_erl!({23, 30, 15}, 5000)
-      ~T[23:30:15.005000]
      iex> Time.from_erl!({23, 30, 15}, {5000, 3})
      ~T[23:30:15.005]
      iex> Time.from_erl!({24, 30, 15})
@@ -467,12 +416,8 @@ defmodule Time do
          Calendar.microsecond(),
          Calendar.calendar()
        ) :: t
-  def from_seconds_after_midnight(
-        seconds,
-        {microsecond, precision} \\ {0, 0},
-        calendar \\ Calendar.ISO
-      )
-      when is_integer(seconds) and microsecond in 0..999_999 and precision in 0..6 do
+  def from_seconds_after_midnight(seconds, microsecond \\ {0, 0}, calendar \\ Calendar.ISO)
+      when is_integer(seconds) do
    seconds_in_day = Integer.mod(seconds, @seconds_per_day)

    {hour, minute, second, {_, _}} =
@@ -483,7 +428,7 @@ defmodule Time do
      hour: hour,
      minute: minute,
      second: second,
-      microsecond: {microsecond, precision}
+      microsecond: microsecond
    }
  end

@@ -501,7 +446,7 @@ defmodule Time do

  """
  @doc since: "1.11.0"
-  @spec to_seconds_after_midnight(Calendar.time()) :: {non_neg_integer(), non_neg_integer()}
+  @spec to_seconds_after_midnight(Calendar.time()) :: {integer(), non_neg_integer()}
  def to_seconds_after_midnight(%{microsecond: {microsecond, _precision}} = time) do
    iso_days = {0, to_day_fraction(time)}
    {Calendar.ISO.iso_days_to_unit(iso_days, :second), microsecond}
@@ -510,18 +455,13 @@ defmodule Time do
  @doc """
  Adds the `amount_to_add` of `unit`s to the given `time`.

-  > #### Prefer `shift/2` {: .info}
-  >
-  > Prefer `shift/2` over `add/3`, as it offers a more ergonomic API.
-  >
-  > `add/3` always considers the unit to be computed according to
-  > the `Calendar.ISO`.
-
  Accepts an `amount_to_add` in any `unit`. `unit` can be
  `:hour`, `:minute`, `:second` or any subsecond precision from
-  `t:System.time_unit/0` for convenience but ultimately they are
-  all converted to microseconds. Negative values will move backwards
-  in time and the default precision is `:second`.
+  `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`.

  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.
@@ -559,6 +499,8 @@ defmodule Time do
      iex> result.microsecond
      {21000, 3}

+  To shift a time by a `Duration` and according to its underlying calendar, use `Time.shift/2`.
+
  """
  @doc since: "1.6.0"
  @spec add(Calendar.time(), integer, :hour | :minute | System.time_unit()) :: t
@@ -579,7 +521,7 @@ defmodule Time do
        do: unit > 0,
        else: unit in ~w(second millisecond microsecond nanosecond)a

-    if not valid? do
+    unless valid? do
      raise ArgumentError,
            "unsupported time unit. Expected :hour, :minute, :second, :millisecond, :microsecond, :nanosecond, or a positive integer, got #{inspect(unit)}"
    end
@@ -694,7 +636,7 @@ defmodule Time do
  @doc """
  Compares two time structs.

-  Returns `:gt` if the first time is later than the second
+  Returns `:gt` if first time is later than the second
  and `:lt` for vice versa. If the two times are equal
  `:eq` is returned.

@@ -720,32 +662,14 @@ defmodule Time do
  """
  @doc since: "1.4.0"
  @spec compare(Calendar.time(), Calendar.time()) :: :lt | :eq | :gt
-  def compare(
-        %{
-          hour: hour1,
-          minute: minute1,
-          second: second1,
-          microsecond: {microsecond1, _},
-          calendar: calendar
-        },
-        %{
-          hour: hour2,
-          minute: minute2,
-          second: second2,
-          microsecond: {microsecond2, _},
-          calendar: calendar
-        }
-      ) do
-    cond do
-      hour1 > hour2 -> :gt
-      hour1 < hour2 -> :lt
-      minute1 > minute2 -> :gt
-      minute1 < minute2 -> :lt
-      second1 > second2 -> :gt
-      second1 < second2 -> :lt
-      microsecond1 > microsecond2 -> :gt
-      microsecond1 < microsecond2 -> :lt
-      true -> :eq
+  def compare(%{calendar: calendar} = time1, %{calendar: calendar} = time2) do
+    %{hour: hour1, minute: minute1, second: second1, microsecond: {microsecond1, _}} = time1
+    %{hour: hour2, minute: minute2, second: second2, microsecond: {microsecond2, _}} = time2
+
+    case {{hour1, minute1, second1, microsecond1}, {hour2, minute2, second2, microsecond2}} do
+      {first, second} when first > second -> :gt
+      {first, second} when first < second -> :lt
+      _ -> :eq
    end
  end

@@ -807,7 +731,7 @@ defmodule Time do
  ## Examples

  Imagine someone implements `Calendar.Holocene`, a calendar based on the
-  Gregorian calendar that adds exactly 10 000 years to the current Gregorian
+  Gregorian calendar that adds exactly 10,000 years to the current Gregorian
  year:

      iex> Time.convert(~T[13:30:15], Calendar.Holocene)
@@ -863,7 +787,7 @@ defmodule Time do
  ## Examples

  Imagine someone implements `Calendar.Holocene`, a calendar based on the
-  Gregorian calendar that adds exactly 10 000 years to the current Gregorian
+  Gregorian calendar that adds exactly 10,000 years to the current Gregorian
  year:

      iex> Time.convert!(~T[13:30:15], Calendar.Holocene)
@@ -873,8 +797,15 @@ defmodule Time do
  @doc since: "1.5.0"
  @spec convert!(Calendar.time(), Calendar.calendar()) :: t
  def convert!(time, calendar) do
-    {:ok, value} = convert(time, calendar)
-    value
+    case convert(time, calendar) do
+      {:ok, value} ->
+        value
+
+      {:error, reason} ->
+        raise ArgumentError,
+              "cannot convert #{inspect(time)} to target calendar #{inspect(calendar)}, " <>
+                "reason: #{inspect(reason)}"
+    end
  end

  @doc """
@@ -924,11 +855,11 @@ defmodule Time do
  def diff(time1, time2, unit \\ :second)

  def diff(time1, time2, :hour) do
-    diff(time1, time2, :microsecond) |> div(3_600_000_000)
+    diff(time1, time2, :second) |> div(3600)
  end

  def diff(time1, time2, :minute) do
-    diff(time1, time2, :microsecond) |> div(60_000_000)
+    diff(time1, time2, :second) |> div(60)
  end

  def diff(
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule Calendar.TimeZoneDatabase do
  @moduledoc """
  This module defines a behaviour for providing time zone data.
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule Code do
  @moduledoc ~S"""
  Utilities for managing code compilation, code evaluation, and code loading.
@@ -50,7 +46,7 @@ defmodule Code do

  You can use `ensure_loaded/1` (as well as `ensure_loaded?/1` and
  `ensure_loaded!/1`) to check if a module is loaded before using it and
-  act accordingly.
+  act.

  ## `ensure_compiled/1` and `ensure_compiled!/1`

@@ -127,11 +123,6 @@ defmodule Code do
      of the imported function/macro. A :remote_function/:remote_macro event
      may still be emitted for the imported module/name/arity.

-    * `{:imported_quoted, meta, module, name, [arity]}` - traced whenever an
-      imported function or macro is processed inside a `quote/2`. `meta` is the
-      call AST metadata, `module` is the module the import is from, followed by
-      the `name` and a list of `arities` of the imported function/macro.
-
    * `{:alias, meta, alias, as, opts}` - traced whenever `alias` is aliased
      to `as`. `meta` is the alias AST metadata and `opts` are the alias options.

@@ -189,7 +180,7 @@ defmodule Code do

      defmodule MyTracer do
        def trace({:remote_function, _meta, module, name, arity}, env) do
-          IO.puts("#{env.file}:#{env.line} #{inspect(module)}.#{name}/#{arity}")
+          IO.puts "#{env.file}:#{env.line} #{inspect(module)}.#{name}/#{arity}"
          :ok
        end

@@ -248,84 +239,19 @@ defmodule Code do
  """
  @type position() :: line() | {line :: pos_integer(), column :: pos_integer()}

-  @typedoc """
-  Options for code formatting functions.
-  """
-  @type format_opt ::
-          {:file, binary()}
-          | {:line, pos_integer()}
-          | {:line_length, pos_integer()}
-          | {:locals_without_parens, keyword()}
-          | {:force_do_end_blocks, boolean()}
-          | {:migrate, boolean()}
-          | {:migrate_atom_interpolations, boolean()}
-          | {:migrate_bitstring_modifiers, boolean()}
-          | {:migrate_call_parens_on_pipe, boolean()}
-          | {:migrate_charlists_as_sigils, boolean()}
-          | {:migrate_unless, boolean()}
-          | {atom(), term()}
-
-  @typedoc """
-  Options for `quoted_to_algebra/2`.
-  """
-  @type quoted_to_algebra_opt ::
-          {:line, pos_integer() | nil}
-          | {:escape, boolean()}
-          | {:locals_without_parens, keyword()}
-          | {:comments, [term()]}
-          | {:syntax_colors, [{Inspect.Opts.color_key(), IO.ANSI.ansidata()}]}
-
-  @typedoc """
-  Options for parsing functions that convert strings to quoted expressions.
-  """
-  @type parser_opts :: [
-          file: binary(),
-          line: pos_integer(),
-          column: pos_integer(),
-          indentation: non_neg_integer(),
-          columns: boolean(),
-          unescape: boolean(),
-          existing_atoms_only: boolean(),
-          token_metadata: boolean(),
-          literal_encoder: (term(), Macro.metadata() -> {:ok, Macro.t()} | {:error, binary()}),
-          static_atoms_encoder: (binary(), Macro.metadata() -> {:ok, term()} | {:error, binary()}),
-          emit_warnings: boolean()
-        ]
-
-  @typedoc """
-  Options for evaluation environment, accepted by `env_for_eval/1`.
-  """
-  @type env_eval_opt ::
-          {:file, binary()}
-          | {:line, pos_integer()}
-          | {:module, module()}
-
-  @typedoc """
-  Options for evaluation functions like `eval_string/3`, `eval_quoted/3`
-  and `eval_quoted_with_env/4`.
-  """
-  @type eval_opt ::
-          {:prune_binding, boolean()}
-          | {:dbg_callback, {module(), atom(), list()}}
-
  @boolean_compiler_options [
    :docs,
    :debug_info,
    :ignore_already_consolidated,
    :ignore_module_conflict,
-    :relative_paths
+    :relative_paths,
+    :warnings_as_errors
  ]

-  @list_compiler_options [:tracers, :parser_options, :erlc_options]
+  @list_compiler_options [:no_warn_undefined, :tracers, :parser_options]

  @available_compiler_options @boolean_compiler_options ++
-                                @list_compiler_options ++
-                                [
-                                  :on_undefined_variable,
-                                  :infer_signatures,
-                                  :no_warn_undefined,
-                                  :module_definition
-                                ]
+                                @list_compiler_options ++ [:on_undefined_variable]

  @doc """
  Lists all required files.
@@ -412,10 +338,10 @@ defmodule Code do

    * `:cache` - (since v1.15.0) when true, the code path is cached
      the first time it is traversed in order to reduce file system
-      operations.
+      operations. It requires Erlang/OTP 26, otherwise it is a no-op.

  """
-  @spec append_path(Path.t(), cache: boolean()) :: boolean()
+  @spec append_path(Path.t(), cache: boolean()) :: true | false
  def append_path(path, opts \\ []) do
    apply(:code, :add_pathz, [to_charlist(Path.expand(path)) | cache(opts)]) == true
  end
@@ -443,7 +369,7 @@ defmodule Code do

    * `:cache` - (since v1.15.0) when true, the code path is cached
      the first time it is traversed in order to reduce file system
-      operations.
+      operations. It requires Erlang/OTP 26, otherwise it is a no-op.

  """
  @spec prepend_path(Path.t(), cache: boolean()) :: boolean()
@@ -472,7 +398,7 @@ defmodule Code do

    * `:cache` - when true, the code path is cached the first time
      it is traversed in order to reduce file system operations.
-
+      It requires Erlang/OTP 26, otherwise it is a no-op.
  """
  @doc since: "1.15.0"
  @spec prepend_paths([Path.t()], cache: boolean()) :: :ok
@@ -501,7 +427,7 @@ defmodule Code do

    * `:cache` - when true, the code path is cached the first time
      it is traversed in order to reduce file system operations.
-
+      It requires Erlang/OTP 26, otherwise it is a no-op.
  """
  @doc since: "1.15.0"
  @spec append_paths([Path.t()], cache: boolean()) :: :ok
@@ -554,7 +480,8 @@ defmodule Code do
  This is the list of directories the Erlang VM uses for finding
  module code. The list of files is managed per Erlang VM node.

-  All paths are expanded with `Path.expand/1` before being deleted.
+  The path is expanded with `Path.expand/1` before being deleted. If the
+  path does not exist, this function returns `false`.
  """
  @doc since: "1.15.0"
  @spec delete_paths([Path.t()]) :: :ok
@@ -580,11 +507,14 @@ defmodule Code do

  ## Options

-  It accepts the same options as both `env_for_eval/1` and
-  `eval_quoted_with_env/4`. Additionally, you may also pass an environment
-  as third argument, so the evaluation happens within that environment.
+  Options can be:

-  ## Return
+    * `:file` - the file to be considered in the evaluation
+
+    * `:line` - the line on which the script starts
+
+  Additionally, you may also pass an environment as second argument,
+  so the evaluation happens within that environment.

  Returns a tuple of the form `{value, binding}`, where `value` is the value
  returned from evaluating `string`. If an error occurs while evaluating
@@ -614,40 +544,32 @@ defmodule Code do
      iex> Enum.sort(binding)
      [a: 3, b: 2]

-  For convenience, you can pass `__ENV__/0` as the `opts_or_env` argument and
+  For convenience, you can pass `__ENV__/0` as the `opts` argument and
  all imports, requires and aliases defined in the current environment
  will be automatically carried over:

-      iex> require Integer, warn: false
-      iex> {result, binding} = Code.eval_string("if Integer.is_odd(a), do: a + b", [a: 1, b: 2], __ENV__)
+      iex> {result, binding} = Code.eval_string("a + b", [a: 1, b: 2], __ENV__)
      iex> result
      3
      iex> Enum.sort(binding)
      [a: 1, b: 2]

  """
-  @spec eval_string(List.Chars.t(), binding, Macro.Env.t() | [eval_opt | env_eval_opt]) ::
-          {term, binding}
-  def eval_string(string, binding \\ [], opts_or_env \\ [])
+  @spec eval_string(List.Chars.t(), binding, Macro.Env.t() | keyword) :: {term, binding}
+  def eval_string(string, binding \\ [], opts \\ [])

  def eval_string(string, binding, %Macro.Env{} = env) do
-    validated_eval_string(string, validate_binding(binding), env_for_eval(env), [])
+    validated_eval_string(string, binding, env)
  end

  def eval_string(string, binding, opts) when is_list(opts) do
-    validated_eval_string(string, validate_binding(binding), env_for_eval(opts), opts)
+    validated_eval_string(string, binding, opts)
  end

-  defp validate_binding(binding) when is_list(binding), do: binding
-
-  defp validate_binding(binding) do
-    raise ArgumentError, "binding must be a list, got: #{inspect(binding)}"
-  end
-
-  defp validated_eval_string(string, binding, env, opts) do
-    %{line: line, file: file} = env
+  defp validated_eval_string(string, binding, opts_or_env) do
+    %{line: line, file: file} = env = env_for_eval(opts_or_env)
    forms = :elixir.string_to_quoted!(to_charlist(string), line, 1, file, [])
-    {value, binding, _env} = eval_verify(:eval_forms, [forms, binding, env, opts])
+    {value, binding, _env} = eval_verify(:eval_forms, [forms, binding, env])
    {value, binding}
  end

@@ -688,8 +610,7 @@ defmodule Code do

  """
  @doc since: "1.15.0"
-  @spec with_diagnostics([log: boolean()], (-> result)) ::
-          {result, [diagnostic(:warning | :error)]}
+  @spec with_diagnostics(keyword(), (-> result)) :: {result, [diagnostic(:warning | :error)]}
        when result: term()
  def with_diagnostics(opts \\ [], fun) do
    value = :erlang.get(:elixir_code_diagnostics)
@@ -722,7 +643,7 @@ defmodule Code do
      Defaults to `true`.
  """
  @doc since: "1.15.0"
-  @spec print_diagnostic(diagnostic(:warning | :error), snippet: boolean()) :: :ok
+  @spec print_diagnostic(diagnostic(:warning | :error), keyword()) :: :ok
  def print_diagnostic(diagnostic, opts \\ []) do
    read_snippet? = Keyword.get(opts, :snippet, true)
    :elixir_errors.print_diagnostic(diagnostic, read_snippet?)
@@ -738,15 +659,13 @@ defmodule Code do

  ## Options

-  Regular options (do not change the AST):
-
    * `:file` - the file which contains the string, used for error
      reporting

    * `:line` - the line the string starts, used for error reporting

    * `:line_length` - the line length to aim for when formatting
-      the document. Defaults to `98`. This value indicates when an expression
+      the document. Defaults to 98. This value indicates when an expression
      should be broken over multiple lines but it is not guaranteed
      to do so. See the "Line length" section below for more information

@@ -763,48 +682,28 @@ defmodule Code do
      If you set it to `false` later on, `do`-`end` blocks won't be
      converted back to keywords.

-  Migration options (change the AST), see the "Migration formatting" section below:
-
-    * `:migrate` (since v1.18.0) - when `true`, sets all other migration options
-      to `true` by default. Defaults to `false`.
-
-    * `:migrate_atom_interpolations` (since v1.21.0) - when `true`, rewrites
-      deprecated atom interpolations to explicit calls to `String.to_unsafe_atom/1`.
-      For example, `:"foo_#{bar}"` becomes `String.to_unsafe_atom("foo_#{bar}")`.
-      Interpolated keywords like `["foo_#{bar}": 1]` are **not** migrated.
-      Defaults to the value of the `:migrate` option. This option changes the AST.
-
-    * `:migrate_bitstring_modifiers` (since v1.18.0) - when `true`,
+    * `:normalize_bitstring_modifiers` (since v1.14.0) - when `true`,
      removes unnecessary parentheses in known bitstring
      [modifiers](`<<>>/1`), for example `<<foo::binary()>>`
      becomes `<<foo::binary>>`, or adds parentheses for custom
      modifiers, where `<<foo::custom_type>>` becomes `<<foo::custom_type()>>`.
-      Defaults to the value of the `:migrate` option. This option changes the AST.
+      Defaults to `true`. This option changes the AST.

-    * `:migrate_call_parens_on_pipe` (since v1.19.0) - when `true`,
-      formats calls on the right-hand side of the pipe operator to always include
-      parentheses, for example `foo |> bar` becomes `foo |> bar()` and
-      `foo |> mod.fun` becomes `foo |> mod.fun()`.
-      Parentheses are always added for qualified calls like `foo |> Bar.bar` even
-      when this option is `false`.
-      Defaults to the value of the `:migrate` option. This option changes the AST.
-
-    * `:migrate_charlists_as_sigils` (since v1.18.0) - when `true`,
+    * `:normalize_charlists_as_sigils` (since v1.15.0) - when `true`,
      formats charlists as [`~c`](`Kernel.sigil_c/2`) sigils, for example
      `'foo'` becomes `~c"foo"`.
-      Defaults to the value of the `:migrate` option. This option changes the AST.
-
-    * `:migrate_unless` (since v1.18.0) - when `true`,
-      rewrites `unless` expressions using `if` with a negated condition, for example
-      `unless foo, do:` becomes `if !foo, do:`.
-      Defaults to the value of the `:migrate` option. This option changes the AST.
+      Defaults to `true`. This option changes the AST.

  ## Design principles

  The formatter was designed under three principles.

-  First, the formatter never changes the semantics of the code by default.
+  First, the formatter never changes the semantics of the code.
  This means the input AST and the output AST are almost always equivalent.
+  The only cases where the formatter will change the AST is when the input AST
+  would cause *compiler warnings* and the output AST won't. The cases where
+  the formatter changes the AST can be disabled through formatting options
+  if desired.

  The second principle is to provide as little configuration as possible.
  This eases the formatter adoption by removing contention points while
@@ -1038,8 +937,9 @@ defmodule Code do

  ## Code comments

-  The formatter handles code comments and guarantees a space is always added
-  between the beginning of the comment (#) and the next character.
+  The formatter also handles code comments in a way to guarantee a space
+  is always added between the beginning of the comment (#) and the next
+  character.

  The formatter also extracts all trailing comments to their previous line.
  For example, the code below
@@ -1051,25 +951,9 @@ defmodule Code do
      # world
      hello

-  While the formatter attempts to preserve comments in most situations,
-  that's not always possible, because code comments are handled apart from
-  the code representation (AST). While the formatter can preserve code
-  comments between expressions and function arguments, the formatter
-  cannot currently preserve them around operators. For example, the following
-  code:
-
-      foo() ||
-        # also check for bar
-        bar()
-
-  will move the code comments to before the operator usage:
-
-      # also check for bar
-      foo() ||
-        bar()
-
-  In some situations, code comments can be seen as ambiguous by the formatter.
-  For example, the comment in the anonymous function below
+  Because code comments are handled apart from the code representation (AST),
+  there are some situations where code comments are seen as ambiguous by the
+  code formatter. For example, the comment in the anonymous function below

      fn
        arg1 ->
@@ -1098,26 +982,11 @@ defmodule Code do
  ## Newlines

  The formatter converts all newlines in code from `\r\n` to `\n`.
-
-  ## Migration formatting
-
-  As part of the Elixir release cycle, deprecations are being introduced,
-  emitting warnings which might require existing code to be changed.
-  In order to reduce the burden on developers when upgrading Elixir to the
-  next version, the formatter exposes some options, disabled by default,
-  in order to automate this process.
-
-  These options should address most of the typical use cases, but given they
-  introduce changes to the AST, there is a non-zero risk for meta-programming
-  heavy projects that relied on a specific AST, or projects that are
-  re-defining functions from the `Kernel`. In such cases, migrations cannot
-  be applied blindly and some extra changes might be needed in order to
-  address the deprecation warnings.
  """
  @doc since: "1.6.0"
-  @spec format_string!(binary, [format_opt]) :: iodata
+  @spec format_string!(binary, keyword) :: iodata
  def format_string!(string, opts \\ []) when is_binary(string) and is_list(opts) do
-    {line_length, opts} = Keyword.pop(opts, :line_length, 98)
+    line_length = Keyword.get(opts, :line_length, 98)

    to_quoted_opts =
      [
@@ -1140,7 +1009,7 @@ defmodule Code do
  available options.
  """
  @doc since: "1.6.0"
-  @spec format_file!(binary, [format_opt]) :: iodata
+  @spec format_file!(binary, keyword) :: iodata
  def format_file!(file, opts \\ []) when is_binary(file) and is_list(opts) do
    string = File.read!(file)
    formatted = format_string!(string, [file: file, line: 1] ++ opts)
@@ -1155,9 +1024,7 @@ defmodule Code do
  Macro arguments are typically transformed by unquoting them into the
  returned quoted expressions (instead of evaluated).

-  See `eval_string/3` for a description of arguments and return types.
-  It accepts the same options as both `env_for_eval/1` and
-  `eval_quoted_with_env/4`.
+  See `eval_string/3` for a description of `binding` and `opts`.

  ## Examples

@@ -1179,20 +1046,11 @@ defmodule Code do
      [a: 1, b: 2]

  """
-  @spec eval_quoted(Macro.t(), binding, Macro.Env.t() | [eval_opt | env_eval_opt]) ::
-          {term, binding}
-  def eval_quoted(quoted, binding \\ [], env_or_opts \\ [])
+  @spec eval_quoted(Macro.t(), binding, Macro.Env.t() | keyword) :: {term, binding}
+  def eval_quoted(quoted, binding \\ [], env_or_opts \\ []) do
+    {value, binding, _env} =
+      eval_verify(:eval_quoted, [quoted, binding, env_for_eval(env_or_opts)])

-  def eval_quoted(quoted, binding, %Macro.Env{} = env) do
-    eval_quoted(quoted, validate_binding(binding), env_for_eval(env), [])
-  end
-
-  def eval_quoted(quoted, binding, opts) when is_list(opts) do
-    eval_quoted(quoted, validate_binding(binding), env_for_eval(opts), opts)
-  end
-
-  defp eval_quoted(quoted, binding, env, opts) do
-    {value, binding, _env} = eval_verify(:eval_quoted, [quoted, binding, env, opts])
    {value, binding}
  end

@@ -1217,12 +1075,8 @@ defmodule Code do
    * `:file` - the file to be considered in the evaluation

    * `:line` - the line on which the script starts
-
-    * `:module` - the module to run the environment on
-
  """
  @doc since: "1.14.0"
-  @spec env_for_eval(Macro.Env.t() | [env_eval_opt]) :: Macro.Env.t()
  def env_for_eval(env_or_opts), do: :elixir.env_for_eval(env_or_opts)

  @doc """
@@ -1242,13 +1096,9 @@ defmodule Code do
      by the modules. You can submit to the `:on_module` tracer event
      and access the variables used by the module from its environment.

-    * `:dbg_callback` - (since v1.20.0) overrides the behaviour of `dbg/2`
-      used in the evaluated code. It must be a `{module, function, args}`
-      tuple, see `dbg/2` for more details.
-
  """
  @doc since: "1.14.0"
-  @spec eval_quoted_with_env(Macro.t(), binding, Macro.Env.t(), [eval_opt]) ::
+  @spec eval_quoted_with_env(Macro.t(), binding, Macro.Env.t(), keyword) ::
          {term, binding, Macro.Env.t()}
  def eval_quoted_with_env(quoted, binding, %Macro.Env{} = env, opts \\ [])
      when is_list(binding) do
@@ -1267,14 +1117,10 @@ defmodule Code do
      Defaults to `"nofile"`.

    * `:line` - the starting line of the string being parsed.
-      Defaults to `1`.
+      Defaults to 1.

    * `:column` - (since v1.11.0) the starting column of the string being parsed.
-      Defaults to `1`.
-
-    * `:indentation` - (since v1.19.0) the indentation for the string being parsed.
-      This is useful when the code parsed is embedded within another document.
-      Defaults to `0`.
+      Defaults to 1.

    * `:columns` - when `true`, attach a `:column` key to the quoted
      metadata. Defaults to `false`.
@@ -1298,9 +1144,9 @@ defmodule Code do
    * `:literal_encoder` (since v1.10.0) - how to encode literals in the AST.
      It must be a function that receives two arguments, the literal and its
      metadata, and it must return `{:ok, ast :: Macro.t}` or
-      `{:error, reason :: binary}`. If you return anything other than the literal
+      `{:error, reason :: binary}`. If you return anything than the literal
      itself as the `term`, then the AST is no longer valid. This option
-      may still be useful for textual analysis of the source code.
+      may still useful for textual analysis of the source code.

    * `:static_atoms_encoder` - the static atom encoder function, see
      "The `:static_atoms_encoder` function" section below. Note this
@@ -1326,7 +1172,7 @@ defmodule Code do
  and keyword lists.

  The encoder function will receive the atom name (as a binary) and a
-  keyword list with the current line and column. It must return
+  keyword list with the current file, line and column. It must return
  `{:ok, token :: term} | {:error, reason :: binary}`.

  The encoder function is supposed to create an atom from the given
@@ -1350,22 +1196,21 @@ defmodule Code do
    * atoms used to represent single-letter sigils like `:sigil_X`
      (but multi-letter sigils like `:sigil_XYZ` are encoded).

-  ## Examples
-
-      iex> Code.string_to_quoted("1 + 3")
-      {:ok, {:+, [line: 1], [1, 3]}}
-
-      iex> Code.string_to_quoted("1 \ 3")
-      {:error, {[line: 1, column: 4], "syntax error before: ", "\"3\""}}
-
  """
-  @spec string_to_quoted(List.Chars.t(), parser_opts) ::
+  @spec string_to_quoted(List.Chars.t(), keyword) ::
          {:ok, Macro.t()} | {:error, {location :: keyword, binary | {binary, binary}, binary}}
  def string_to_quoted(string, opts \\ []) when is_list(opts) do
    file = Keyword.get(opts, :file, "nofile")
    line = Keyword.get(opts, :line, 1)
    column = Keyword.get(opts, :column, 1)
-    :elixir.string_to_quoted(to_charlist(string), line, column, file, opts)
+
+    case :elixir.string_to_tokens(to_charlist(string), line, column, file, opts) do
+      {:ok, tokens} ->
+        :elixir.tokens_to_quoted(tokens, file, opts)
+
+      {:error, _error_msg} = error ->
+        error
+    end
  end

  @doc """
@@ -1379,7 +1224,7 @@ defmodule Code do

  Check `string_to_quoted/2` for options information.
  """
-  @spec string_to_quoted!(List.Chars.t(), parser_opts) :: Macro.t()
+  @spec string_to_quoted!(List.Chars.t(), keyword) :: Macro.t()
  def string_to_quoted!(string, opts \\ []) when is_list(opts) do
    file = Keyword.get(opts, :file, "nofile")
    line = Keyword.get(opts, :line, 1)
@@ -1394,15 +1239,12 @@ defmodule Code do
  while preserving information like comments and literals position.

  Returns `{:ok, quoted_form, comments}` if it succeeds,
-  `{:error, {location, error, token}}` otherwise, where `location`
-  is keyword metadata containing the line and column of the error.
+  `{:error, {line, error, token}}` otherwise.

  Comments are maps with the following fields:

    * `:line` - The line number of the source code

-    * `:column` - The column number of the source code
-
    * `:text` - The full text of the comment, including the leading `#`

    * `:previous_eol_count` - How many end of lines there are between the comment and the previous AST node or comment
@@ -1433,7 +1275,7 @@ defmodule Code do

  """
  @doc since: "1.13.0"
-  @spec string_to_quoted_with_comments(List.Chars.t(), parser_opts) ::
+  @spec string_to_quoted_with_comments(List.Chars.t(), keyword) ::
          {:ok, Macro.t(), list(map())} | {:error, {location :: keyword, term, term}}
  def string_to_quoted_with_comments(string, opts \\ []) when is_list(opts) do
    charlist = to_charlist(string)
@@ -1444,7 +1286,8 @@ defmodule Code do
    Process.put(:code_formatter_comments, [])
    opts = [preserve_comments: &preserve_comments/5] ++ opts

-    with {:ok, forms} <- :elixir.string_to_quoted(charlist, line, column, file, opts) do
+    with {:ok, tokens} <- :elixir.string_to_tokens(charlist, line, column, file, opts),
+         {:ok, forms} <- :elixir.tokens_to_quoted(tokens, file, opts) do
      comments = Enum.reverse(Process.get(:code_formatter_comments))
      {:ok, forms, comments}
    end
@@ -1457,14 +1300,12 @@ defmodule Code do

  Returns the AST and a list of comments if it succeeds, raises an exception
  otherwise. The exception is a `TokenMissingError` in case a token is missing
-  (usually because the expression is incomplete), `MismatchedDelimiterError`
-  (in case of mismatched opening and closing delimiters) and `SyntaxError`
-  otherwise.
+  (usually because the expression is incomplete), `SyntaxError` otherwise.

  Check `string_to_quoted/2` for options information.
  """
  @doc since: "1.13.0"
-  @spec string_to_quoted_with_comments!(List.Chars.t(), parser_opts) :: {Macro.t(), list(map())}
+  @spec string_to_quoted_with_comments!(List.Chars.t(), keyword) :: {Macro.t(), list(map())}
  def string_to_quoted_with_comments!(string, opts \\ []) do
    charlist = to_charlist(string)

@@ -1473,11 +1314,13 @@ defmodule Code do
        {forms, comments}

      {:error, {location, error, token}} ->
-        file = Keyword.get(opts, :file, "nofile")
-        line = Keyword.get(opts, :line, 1)
-        column = Keyword.get(opts, :column, 1)
-        input = {charlist, line, column, Keyword.get(opts, :indentation, 0)}
-        :elixir_errors.parse_error(location, file, error, token, input)
+        :elixir_errors.parse_error(
+          location,
+          Keyword.get(opts, :file, "nofile"),
+          error,
+          token,
+          {charlist, Keyword.get(opts, :line, 1), Keyword.get(opts, :column, 1)}
+        )
    end
  end

@@ -1487,7 +1330,7 @@ defmodule Code do
    comment = %{
      line: line,
      column: column,
-      previous_eol_count: min(previous_eol_count(tokens), last_comment_distance(comments, line)),
+      previous_eol_count: previous_eol_count(tokens),
      next_eol_count: next_eol_count(rest, 0),
      text: List.to_string(comment)
    }
@@ -1501,9 +1344,6 @@ defmodule Code do
  defp next_eol_count([?\r, ?\n | rest], count), do: next_eol_count(rest, count + 1)
  defp next_eol_count(_, count), do: count

-  defp last_comment_distance([%{line: last_line} | _], line), do: line - last_line
-  defp last_comment_distance([], _line), do: :infinity
-
  defp previous_eol_count([{token, {_, _, count}} | _])
       when token in [:eol, :",", :";"] and count > 0 do
    count
@@ -1549,9 +1389,6 @@ defmodule Code do

  ## Options

-  This function accepts all options supported by `format_string!/2` for controlling
-  code formatting, plus these additional options:
-
    * `:comments` - the list of comments associated with the quoted expression.
      Defaults to `[]`. It is recommended that both `:token_metadata` and
      `:literal_encoder` options are given to `string_to_quoted_with_comments/2`
@@ -1562,17 +1399,17 @@ defmodule Code do
      `string_to_quoted/2`, setting this option to `false` will prevent it from
      escaping the sequences twice. Defaults to `true`.

+    * `:locals_without_parens` - a keyword list of name and arity
+      pairs that should be kept without parens whenever possible.
+      The arity may be the atom `:*`, which implies all arities of
+      that name. The formatter already includes a list of functions
+      and this option augments this list.
+
    * `:syntax_colors` - a keyword list of colors the output is colorized.
      See `Inspect.Opts` for more information.
-
-  See `format_string!/2` for the full list of formatting options including
-  `:file`, `:line`, `:locals_without_parens`, `:force_do_end_blocks`, and all
-  migration options like `:migrate_charlists_as_sigils`. Note `:line_length`
-  does not apply here.
  """
  @doc since: "1.13.0"
-  @spec quoted_to_algebra(Macro.t(), [format_opt() | quoted_to_algebra_opt()]) ::
-          Inspect.Algebra.t()
+  @spec quoted_to_algebra(Macro.t(), keyword) :: Inspect.Algebra.t()
  def quoted_to_algebra(quoted, opts \\ []) do
    quoted
    |> Code.Normalizer.normalize(opts)
@@ -1650,19 +1487,13 @@ defmodule Code do
        nil

      :proceed ->
-        try do
-          loaded =
-            Module.ParallelChecker.verify(fn ->
-              :elixir_compiler.string(charlist, file, fn _, _ -> :ok end)
-            end)
+        loaded =
+          Module.ParallelChecker.verify(fn ->
+            :elixir_compiler.string(charlist, file, fn _, _ -> :ok end)
+          end)

-          :elixir_code_server.cast({:required, file})
-          loaded
-        catch
-          kind, reason ->
-            :elixir_code_server.call({:release, file})
-            :erlang.raise(kind, reason, __STACKTRACE__)
-        end
+        :elixir_code_server.cast({:required, file})
+        loaded
    end
  end

@@ -1688,7 +1519,7 @@ defmodule Code do
  @doc """
  Stores all given compilation options.

-  Changing the compilation options affects all processes
+  Changing the compilation options affect all processes
  running in a given Erlang VM node. To store individual
  options and for a description of all options, see
  `put_compiler_option/2`.
@@ -1697,8 +1528,8 @@ defmodule Code do

  ## Examples

-      Code.compiler_options(infer_signatures: false)
-      #=> %{infer_signatures: [:elixir]}
+      Code.compiler_options(warnings_as_errors: true)
+      #=> %{warnings_as_errors: false}

  """
  @spec compiler_options(Enumerable.t({atom, term})) :: %{optional(atom) => term}
@@ -1727,12 +1558,6 @@ defmodule Code do
    :elixir_config.get(key)
  end

-  # TODO: Remove me in Elixir v2.0
-  def get_compiler_option(:warnings_as_errors) do
-    IO.warn(":warnings_as_errors is deprecated as part of Code.get_compiler_option/1")
-    :ok
-  end
-
  @doc """
  Returns a list with all available compiler options.

@@ -1752,32 +1577,25 @@ defmodule Code do
  @doc """
  Stores a compilation option.

-  Changing the compilation options affects all processes running in a
+  Changing the compilation options affect all processes running in a
  given Erlang VM node.

  Available options are:

-    * `:debug_info` - when `true`, retains debug information in the compiled
-      module. This option can also be overridden per module using the `@compile`
-      directive. Defaults to `true`.
+    * `:docs` - when `true`, retains documentation in the compiled module.
+      Defaults to `true`.

-      This enables tooling to partially reconstruct the original source code,
-      for instance, to perform static analysis of code. Therefore, disabling
+    * `:debug_info` - when `true`, retains debug information in the compiled
+      module. Defaults to `true`.
+      This enables static analysis tools as it allows developers to
+      partially reconstruct the original source code. Therefore, disabling
      `:debug_info` is not recommended as it removes the ability of the
      Elixir compiler and other tools to provide feedback. If you want to
      remove the `:debug_info` while deploying, tools like `mix release`
      already do such by default.
-
-      Other environments, such as `mix test`, automatically disable this
-      via the `:test_elixirc_options` project configuration, as there is
-      typically no need to store debug chunks for test files.
-
-    * `:docs` - when `true`, retains documentation in the compiled module.
-      Defaults to `true`.
-
-    * `:erlc_options` (since v1.21.0) - a list of Erlang compiler options. For example,
-      `erlc_options: [:beam_debug_info, :beam_debug_stack]` emits Erlang/OTP
-      debug metadata for BEAM debuggers. Defaults to `[]`.
+      Additionally, `mix test` disables it via the `:test_elixirc_options`
+      project configuration option.
+      This option can also be overridden per module using the `@compile` directive.

    * `:ignore_already_consolidated` (since v1.10.0) - when `true`, does not warn
      when a protocol has already been consolidated and a new implementation is added.
@@ -1786,41 +1604,20 @@ defmodule Code do
    * `:ignore_module_conflict` - when `true`, does not warn when a module has
      already been defined. Defaults to `false`.

-    * `:infer_signatures` (since v1.18.0) - a list of applications whose modules
-      should be used during type inference. When `false`, it disables module-local
-      signature inference used when type checking remote calls to the compiled
-      module. Type checking will be executed regardless of the value of this option.
-      Mix projects will set this option to your dependencies list in dev/prod, and
-      it will disable this option during test (as there is typically no need to infer
-      signatures for test files). Outside of Mix projects, it defaults to `[:elixir]`.
+    * `:relative_paths` - when `true`, uses relative paths in quoted nodes,
+      warnings, and errors generated by the compiler. Note disabling this option
+      won't affect runtime warnings and errors. Defaults to `true`.

-    * `:module_definition` (since v1.20.0) - stores if the module definition should
-      be `:compiled` (the default) or `:interpreted`. Note this does not affect the
-      `.beam` file written to disk, only how the contents inside `defmodule` are
-      executed. Using the `:interpreted` mode may offer better compilation times for
-      large projects, especially on machines with high core count, however, it comes
-      with some downsides:
-
-      * Errors during compilation may have less precise stacktraces
-
-      * Anonymous functions within `defmodule` can have only up to 20 arguments.
-        If this is an issue, you can use maps or tuples to group the data.
-        Note the functions themselves inside `defmodule`, such as the ones defined
-        inside `def` and friends, can still have up to 255 arguments
+    * `:warnings_as_errors` - causes compilation to fail when warnings are
+      generated. Defaults to `false`.

    * `:no_warn_undefined` (since v1.10.0) - list of modules and `{Mod, fun, arity}`
      tuples that will not emit warnings that the module or function does not exist
      at compilation time. Pass atom `:all` to skip warning for all undefined
      functions. This can be useful when doing dynamic compilation. Defaults to `[]`.

-    * `:on_undefined_variable` (since v1.15.0) - either `:raise` or `:warn`.
-      When `:raise` (the default), undefined variables will trigger a compilation
-      error. You may set it to `:warn` if you want undefined variables to
-      emit a warning and expand as to a local call to the zero-arity function
-      of the same name (for example, `node` would be expanded as `node()`).
-      This `:warn` behavior only exists for compatibility reasons when working
-      with old dependencies, its usage is discouraged and it will be removed
-      in future releases.
+    * `:tracers` (since v1.10.0) - a list of tracers (modules) to be used during
+      compilation. See the module docs for more information. Defaults to `[]`.

    * `:parser_options` (since v1.10.0) - a keyword list of options to be given
      to the parser when compiling files. It accepts the same options as
@@ -1831,12 +1628,14 @@ defmodule Code do
      and `compile_file/2` but not `string_to_quoted/2` and friends, as the
      latter is used for other purposes beyond compilation.

-    * `:relative_paths` - when `true`, uses relative paths in quoted nodes,
-      warnings, and errors generated by the compiler. Note disabling this option
-      won't affect runtime warnings and errors. Defaults to `true`.
-
-    * `:tracers` (since v1.10.0) - a list of tracers (modules) to be used during
-      compilation. See the module docs for more information. Defaults to `[]`.
+    * `:on_undefined_variable` (since v1.15.0) - either `:raise` or `:warn`.
+      When `:raise` (the default), undefined variables will trigger a compilation
+      error. You may be set it to `:warn` if you want undefined variables to
+      emit a warning and expand as to a local call to the zero-arity function
+      of the same name (for example, `node` would be expanded as `node()`).
+      This `:warn` behavior only exists for compatibility reasons when working
+      with old dependencies, its usage is discouraged and it will be removed
+      in future releases.

  It always returns `:ok`. Raises an error for invalid options.

@@ -1857,6 +1656,16 @@ defmodule Code do
    :ok
  end

+  def put_compiler_option(:no_warn_undefined, value) do
+    if value != :all and not is_list(value) do
+      raise "compiler option :no_warn_undefined should be a list or the atom :all, " <>
+              "got: #{inspect(value)}"
+    end
+
+    :elixir_config.put(:no_warn_undefined, value)
+    :ok
+  end
+
  def put_compiler_option(key, value) when key in @list_compiler_options do
    if not is_list(value) do
      raise "compiler option #{inspect(key)} should be a list, got: #{inspect(value)}"
@@ -1876,70 +1685,9 @@ defmodule Code do
    :ok
  end

-  def put_compiler_option(:module_definition, value) do
-    if value not in [:interpreted, :compiled] do
-      raise "compiler option :module_definition should be either :interpreted or :compiled, got: #{inspect(value)}"
-    end
-
-    :elixir_config.put(:module_definition, value)
-    :ok
-  end
-
-  def put_compiler_option(:infer_signatures, value) do
-    value =
-      cond do
-        value == false ->
-          false
-
-        value == true ->
-          [:elixir]
-
-        is_list(value) and Enum.all?(value, &is_atom/1) ->
-          value
-
-        true ->
-          raise "compiler option :infer_signatures should be a boolean or a list of applications, got: #{inspect(value)}"
-      end
-
-    :elixir_config.put(:infer_signatures, value)
-    :ok
-  end
-
-  def put_compiler_option(:no_warn_undefined, value) do
-    if value != :all and not is_list(value) do
-      raise "compiler option :no_warn_undefined should be a list or the atom :all, " <>
-              "got: #{inspect(value)}"
-    end
-
-    :elixir_config.put(:no_warn_undefined, value)
-    :ok
-  end
-
-  # TODO: Remove me in Elixir v2.0
-  def put_compiler_option(:warnings_as_errors, _value) do
-    IO.warn(
-      ":warnings_as_errors is deprecated as part of Code.put_compiler_option/2, " <>
-        "instead you must pass it as a --warnings-as-errors flag. " <>
-        "If you need to set it as a default in a mix task, you can also set it under aliases: " <>
-        "[compile: \"compile --warnings-as-errors\"]"
-    )
-
-    :ok
-  end
-
-  # TODO: Remove me in Elixir v2.0
+  # TODO: Make this option have no effect on Elixir v2.0
+  # TODO: Warn if mode is :warn on Elixir v1.19
  def put_compiler_option(:on_undefined_variable, value) when value in [:raise, :warn] do
-    if value == :warn do
-      IO.warn_once(
-        {__MODULE__, :on_undefined_variable},
-        fn ->
-          "setting :on_undefined_variable to :warn is deprecated. " <>
-            "The warning behaviour will be removed in future releases"
-        end,
-        3
-      )
-    end
-
    :elixir_config.put(:on_undefined_variable, value)
    :ok
  end
@@ -2150,7 +1898,7 @@ defmodule Code do
  If the module being checked is currently in a compiler deadlock,
  this function returns `{:error, :unavailable}`. Unavailable doesn't
  necessarily mean the module doesn't exist, just that it is not currently
-  available, but it may (or may not) become available in the future.
+  available, but it (or may not) become available in the future.

  Therefore, if you can only continue if the module is available, use
  `ensure_compiled!/1` instead. In particular, do not do this:
@@ -2204,7 +1952,7 @@ defmodule Code do
    case :code.ensure_loaded(module) do
      {:error, :nofile} = error ->
        if can_await_module_compilation?() do
-          case Kernel.ErrorHandler.ensure_compiled(module, :module, mode, nil) do
+          case Kernel.ErrorHandler.ensure_compiled(module, :module, mode) do
            :found -> {:module, module}
            :deadlock -> {:error, :unavailable}
            :not_found -> {:error, :nofile}
@@ -2226,7 +1974,7 @@ defmodule Code do

  ## Examples

-      iex> Code.loaded?(String)
+      iex> Code.loaded?(Atom)
      true

      iex> Code.loaded?(NotYetLoaded)
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule Code.Formatter do
  @moduledoc false
  import Inspect.Algebra, except: [format: 2, surround: 3, surround: 4]
@@ -20,7 +16,7 @@ defmodule Code.Formatter do
  @ampersand_prec Code.Identifier.unary_op(:&) |> elem(1)

  # Operators that are composed of multiple binary operators
-  @multi_binary_operators [:..//]
+  @multi_binary_operators [:"..//"]

  # Operators that do not have space between operands
  @no_space_binary_operators [:.., :"//"]
@@ -35,37 +31,30 @@ defmodule Code.Formatter do
  @right_new_line_before_binary_operators [:|, :when]

  # Operators that are logical cannot be mixed without parens
-  @required_parens_logical_binary_operands [:|||, :||, :or, :&&&, :&&, :and]
+  @required_parens_logical_binary_operands [:||, :|||, :or, :&&, :&&&, :and]

  # Operators with next break fits
  @next_break_fits_operators [:<-, :==, :!=, :=~, :===, :!==, :<, :>, :<=, :>=, :=, :"::"]

-  # Operators that always require parens even
-  # when they are their own parents as they are not semantically associative
-  @required_parens_even_when_parent [:--, :---]
-
-  # Operators that always require parens on operands
-  # when they are the parent of another operator with a difference precedence
-  # Most operators are listed, except comparison, arithmetic, and low precedence
+  # Operators that always require parens on operands when they are the parent
  @required_parens_on_binary_operands [
+    :|>,
    :<<<,
    :>>>,
-    :|>,
    :<~,
    :~>,
    :<<~,
    :~>>,
    :<~>,
    :"<|>",
-    :in,
    :"^^^",
-    :"//",
-    :++,
-    :--,
    :+++,
    :---,
-    :<>,
-    :..
+    :in,
+    :++,
+    :--,
+    :..,
+    :<>
  ]

  @locals_without_parens [
@@ -158,7 +147,6 @@ defmodule Code.Formatter do
  @doc """
  Converts the quoted expression into an algebra document.
  """
-  @spec to_algebra(Macro.t(), keyword()) :: Inspect.Algebra.t()
  def to_algebra(quoted, opts \\ []) do
    comments = Keyword.get(opts, :comments, [])

@@ -194,12 +182,8 @@ defmodule Code.Formatter do
    locals_without_parens = Keyword.get(opts, :locals_without_parens, [])
    file = Keyword.get(opts, :file, nil)
    sigils = Keyword.get(opts, :sigils, [])
-    migrate = Keyword.get(opts, :migrate, false)
-    migrate_atom_interpolations = Keyword.get(opts, :migrate_atom_interpolations, migrate)
-    migrate_bitstring_modifiers = Keyword.get(opts, :migrate_bitstring_modifiers, migrate)
-    migrate_call_parens_on_pipe = Keyword.get(opts, :migrate_call_parens_on_pipe, migrate)
-    migrate_charlists_as_sigils = Keyword.get(opts, :migrate_charlists_as_sigils, migrate)
-    migrate_unless = Keyword.get(opts, :migrate_unless, migrate)
+    normalize_bitstring_modifiers = Keyword.get(opts, :normalize_bitstring_modifiers, true)
+    normalize_charlists_as_sigils = Keyword.get(opts, :normalize_charlists_as_sigils, true)
    syntax_colors = Keyword.get(opts, :syntax_colors, [])

    sigils =
@@ -224,11 +208,8 @@ defmodule Code.Formatter do
      comments: comments,
      sigils: sigils,
      file: file,
-      migrate_atom_interpolations: migrate_atom_interpolations,
-      migrate_bitstring_modifiers: migrate_bitstring_modifiers,
-      migrate_call_parens_on_pipe: migrate_call_parens_on_pipe,
-      migrate_charlists_as_sigils: migrate_charlists_as_sigils,
-      migrate_unless: migrate_unless,
+      normalize_bitstring_modifiers: normalize_bitstring_modifiers,
+      normalize_charlists_as_sigils: normalize_charlists_as_sigils,
      inspect_opts: %Inspect.Opts{syntax_colors: syntax_colors}
    }
  end
@@ -285,7 +266,7 @@ defmodule Code.Formatter do
  end

  defp quoted_to_algebra({var, _meta, var_context}, _context, state) when is_atom(var_context) do
-    {var |> Atom.to_string() |> string() |> color_doc(:variable, state.inspect_opts), state}
+    {var |> Atom.to_string() |> string() |> color(:variable, state.inspect_opts), state}
  end

  defp quoted_to_algebra({:<<>>, meta, entries}, _context, state) do
@@ -336,20 +317,14 @@ defmodule Code.Formatter do
  end

  defp quoted_to_algebra(
-         {{:., _, [:erlang, :binary_to_atom]}, _, [{:<<>>, _, entries} = bitstring, :utf8]} =
-           quoted,
+         {{:., _, [:erlang, :binary_to_atom]}, _, [{:<<>>, _, entries}, :utf8]} = quoted,
         context,
         state
       ) do
-    cond do
-      not interpolated?(entries) ->
-        remote_to_algebra(quoted, context, state)
-
-      state.migrate_atom_interpolations ->
-        quoted_to_algebra(quote(do: String.to_unsafe_atom(unquote(bitstring))), context, state)
-
-      true ->
-        interpolation_to_algebra(entries, @double_quote, state, ":\"", @double_quote)
+    if interpolated?(entries) do
+      interpolation_to_algebra(entries, @double_quote, state, ":\"", @double_quote)
+    else
+      remote_to_algebra(quoted, context, state)
    end
  end

@@ -422,7 +397,7 @@ defmodule Code.Formatter do
      {@double_heredoc
       |> concat(string)
       |> concat(@double_heredoc)
-       |> color_doc(:string, state.inspect_opts)
+       |> color(:string, state.inspect_opts)
       |> force_unfit(), state}
    else
      string = escape_string(string, @double_quote)
@@ -430,7 +405,7 @@ defmodule Code.Formatter do
      {@double_quote
       |> concat(string)
       |> concat(@double_quote)
-       |> color_doc(:string, state.inspect_opts), state}
+       |> color(:string, state.inspect_opts), state}
    end
  end

@@ -462,7 +437,7 @@ defmodule Code.Formatter do
  end

  defp quoted_to_algebra({:__block__, _meta, []}, _context, state) do
-    {color_doc("nil", nil, state.inspect_opts), state}
+    {color("nil", nil, state.inspect_opts), state}
  end

  defp quoted_to_algebra({:__block__, meta, args} = block, _context, state) when is_list(args) do
@@ -479,7 +454,7 @@ defmodule Code.Formatter do
      end

    {Enum.reduce(tail, doc, &concat(&2, "." <> Atom.to_string(&1)))
-     |> color_doc(:atom, state.inspect_opts), state}
+     |> color(:atom, state.inspect_opts), state}
  end

  # &1
@@ -502,62 +477,6 @@ defmodule Code.Formatter do
    binary_op_to_algebra(:in, "not in", meta, left, right, context, state)
  end

-  # disable migrate_call_parens_on_pipe within defmacro
-  defp quoted_to_algebra(
-         {atom, _, [{:|>, _, _}, _]} = ast,
-         context,
-         %{migrate_call_parens_on_pipe: true} = state
-       )
-       when atom in [:defmacro, :defmacrop] do
-    quoted_to_algebra(ast, context, %{state | migrate_call_parens_on_pipe: false})
-  end
-
-  defp quoted_to_algebra(
-         {atom, _, [{:unless, _, _}, _]} = ast,
-         context,
-         %{migrate_unless: true} = state
-       )
-       when atom in [:defmacro, :defmacrop] do
-    quoted_to_algebra(ast, context, %{state | migrate_unless: false})
-  end
-
-  # rewrite unless as if!
-  defp quoted_to_algebra(
-         {:unless, meta, [condition, block]},
-         context,
-         %{migrate_unless: true} = state
-       ) do
-    quoted_to_algebra({:if, meta, [negate_condition(condition), block]}, context, state)
-  end
-
-  # a |> b() |> unless(...) => a |> b() |> Kernel.!() |> unless(...)
-  defp quoted_to_algebra(
-         {:|>, meta1, [{:|>, _, _} = condition, {:unless, meta2, [block]}]},
-         context,
-         %{migrate_unless: true} = state
-       ) do
-    negated_condition = {:|>, [], [condition, {{:., [], [Kernel, :!]}, [closing: []], []}]}
-
-    quoted_to_algebra(
-      {:|>, meta1, [negated_condition, {:if, meta2, [block]}]},
-      context,
-      state
-    )
-  end
-
-  # condition |> unless(...) => negated(condition) |> unless(...)
-  defp quoted_to_algebra(
-         {:|>, meta1, [condition, {:unless, meta2, [block]}]},
-         context,
-         %{migrate_unless: true} = state
-       ) do
-    quoted_to_algebra(
-      {:|>, meta1, [negate_condition(condition), {:if, meta2, [block]}]},
-      context,
-      state
-    )
-  end
-
  # ..
  defp quoted_to_algebra({:.., _meta, []}, context, state) do
    if context in [:no_parens_arg, :no_parens_one_arg] do
@@ -573,7 +492,7 @@ defmodule Code.Formatter do
  end

  # 1..2//3
-  defp quoted_to_algebra({:..//, meta, [left, middle, right]}, context, state) do
+  defp quoted_to_algebra({:"..//", meta, [left, middle, right]}, context, state) do
    quoted_to_algebra({:"//", meta, [{:.., meta, [left, middle]}, right]}, context, state)
  end

@@ -605,12 +524,20 @@ defmodule Code.Formatter do
      if keyword_key?(left_arg) do
        {left, state} =
          case left_arg do
-            {:__block__, _, [atom]} when is_atom(atom) ->
-              formatted = Macro.inspect_atom(:key, atom, escape: &escape_atom/2)
+            # TODO: Remove this clause in v1.18 when we no longer quote operator :..//
+            {:__block__, _, [:"..//"]} ->
+              {string(~S{"..//":}), state}

-              {formatted
-               |> string()
-               |> color_doc(:atom, state.inspect_opts), state}
+            {:__block__, _, [atom]} when is_atom(atom) ->
+              iodata =
+                if Macro.classify_atom(atom) in [:identifier, :unquoted] do
+                  [Atom.to_string(atom), ?:]
+                else
+                  [?", atom |> Atom.to_string() |> String.replace("\"", "\\\""), ?", ?:]
+                end
+
+              {iodata |> IO.iodata_to_binary() |> string() |> color(:atom, state.inspect_opts),
+               state}

            {{:., _, [:erlang, :binary_to_atom]}, _, [{:<<>>, _, entries}, :utf8]} ->
              interpolation_to_algebra(entries, @double_quote, state, "\"", "\":")
@@ -626,22 +553,16 @@ defmodule Code.Formatter do
      end

    doc =
-      concat(
-        group(left),
-        with_next_break_fits(next_break_fits?(right_arg, state), right, fn right ->
-          nest(glue(op, right), 2, :break)
-        end)
-      )
+      with_next_break_fits(next_break_fits?(right_arg, state), right, fn right ->
+        concat(group(left), group(nest(glue(op, group(right)), 2, :break)))
+      end)

    {doc, state}
  end

  # #PID's and #Ref's may appear on regular AST
-  # Other foreign structures, such as maps and structs,
-  # may appear from Macro.to_string, so we stick a limit,
-  # although they won't be formatted accordingly.
  defp quoted_to_algebra(unknown, _context, state) do
-    {inspect(unknown, printable_limit: :infinity), state}
+    {inspect(unknown), state}
  end

  ## Blocks
@@ -711,7 +632,7 @@ defmodule Code.Formatter do
        Atom.to_string(op)
      end

-    {color_doc(op_string, :operator, state.inspect_opts) |> concat(doc), state}
+    {color(op_string, :operator, state.inspect_opts) |> concat(doc), state}
  end

  defp maybe_binary_op_to_algebra(fun, meta, args, context, state) do
@@ -814,13 +735,15 @@ defmodule Code.Formatter do
    {right, state} =
      binary_operand_to_algebra(right_arg, right_context, state, op, op_info, :right, 0)

-    {op_string, right} =
+    doc =
      cond do
        op in @no_space_binary_operators ->
-          {op_string, group(right)}
+          op_doc = color(op_string, :operator, state.inspect_opts)
+          concat(concat(group(left), op_doc), group(right))

        op in @no_newline_binary_operators ->
-          {" " <> op_string <> " ", group(right)}
+          op_doc = color(" " <> op_string <> " ", :operator, state.inspect_opts)
+          concat(concat(group(left), op_doc), group(right))

        true ->
          eol? = eol?(meta, state)
@@ -828,15 +751,14 @@ defmodule Code.Formatter do
          next_break_fits? =
            op in @next_break_fits_operators and next_break_fits?(right_arg, state) and not eol?

-          {" " <> op_string,
-           with_next_break_fits(next_break_fits?, right, fn right ->
-             right = nest(concat(break(), right), nesting, :break)
-             if eol?, do: force_unfit(right), else: right
-           end)}
+          with_next_break_fits(next_break_fits?, right, fn right ->
+            op_doc = color(" " <> op_string, :operator, state.inspect_opts)
+            right = nest(glue(op_doc, group(right)), nesting, :break)
+            right = if eol?, do: force_unfit(right), else: right
+            concat(group(left), group(right))
+          end)
      end

-    op_doc = color_doc(op_string, :operator, state.inspect_opts)
-    doc = concat(concat(group(left), op_doc), group(right))
    {doc, state}
  end

@@ -858,38 +780,6 @@ defmodule Code.Formatter do
    {wrap_in_parens(doc), state}
  end

-  # |> var
-  # |> var()
-  defp binary_operand_to_algebra(
-         {var, meta, var_context},
-         context,
-         %{migrate_call_parens_on_pipe: true} = state,
-         :|>,
-         _parent_info,
-         :right,
-         _nesting
-       )
-       when is_atom(var) and is_atom(var_context) do
-    operand = {var, meta, []}
-    quoted_to_algebra(operand, context, state)
-  end
-
-  # |> var.fun
-  # |> var.fun()
-  defp binary_operand_to_algebra(
-         {{:., _, [_, fun]} = call, meta, []},
-         context,
-         %{migrate_call_parens_on_pipe: true} = state,
-         :|>,
-         _parent_info,
-         :right,
-         _nesting
-       )
-       when is_atom(fun) do
-    meta = Keyword.put_new_lazy(meta, :closing, fn -> [line: meta[:line]] end)
-    quoted_to_algebra({call, meta, []}, context, state)
-  end
-
  defp binary_operand_to_algebra(operand, context, state, parent_op, parent_info, side, nesting) do
    {parent_assoc, parent_prec} = parent_info

@@ -899,13 +789,14 @@ defmodule Code.Formatter do
      op_string = Atom.to_string(op)

      cond do
-        # If we have the same operator and it is in the correct side,
-        # we don't add parens unless it is explicitly required.
-        parent_assoc == side and op == parent_op and op not in @required_parens_even_when_parent ->
+        # If the operator has the same precedence as the parent and is on
+        # the correct side, we respect the nesting rule to avoid multiple
+        # nestings. This only applies for left associativity or same operator.
+        parent_prec == prec and parent_assoc == side and (side == :left or op == parent_op) ->
          binary_op_to_algebra(op, op_string, meta, left, right, context, state, nesting)

-        # If the operator requires parens (most of them do) or we are mixing logical operators
-        # or the precedence is inverted or it is in the wrong side, then we *need* parenthesis.
+        # If the parent requires parens or the precedence is inverted or
+        # it is in the wrong side, then we *need* parenthesis.
        (parent_op in @required_parens_on_binary_operands and op not in @no_space_binary_operators) or
          (op in @required_parens_logical_binary_operands and
             parent_op in @required_parens_logical_binary_operands) or parent_prec > prec or
@@ -1062,7 +953,7 @@ 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, escape: &escape_atom/2)
+    fun = Macro.inspect_atom(:remote_call, fun)
    {target_doc |> nest(1) |> concat(string(".#{fun}/#{arity}")), state}
  end

@@ -1109,9 +1000,7 @@ defmodule Code.Formatter do
    {target_doc, state} = remote_target_to_algebra(target, state)

    fun_doc =
-      Macro.inspect_atom(:remote_call, fun, escape: &escape_atom/2)
-      |> string()
-      |> color_doc(:call, state.inspect_opts)
+      Macro.inspect_atom(:remote_call, fun) |> string() |> color(:call, state.inspect_opts)

    remote_doc = target_doc |> concat(".") |> concat(fun_doc)

@@ -1179,7 +1068,7 @@ defmodule Code.Formatter do
      fun
      |> Atom.to_string()
      |> string()
-      |> color_doc(:call, state.inspect_opts)
+      |> color(:call, state.inspect_opts)
      |> concat(call_doc)

    doc = if wrap_in_parens?, do: wrap_in_parens(doc), else: doc
@@ -1273,7 +1162,7 @@ defmodule Code.Formatter do
        args_doc =
          if skip_parens? do
            left_doc
-            |> concat(group(right_doc, :optimistic))
+            |> concat(next_break_fits(group(right_doc, :inherit), :enabled))
            |> nest(:cursor, :break)
          else
            right_doc =
@@ -1281,7 +1170,8 @@ defmodule Code.Formatter do
              |> nest(2, :break)
              |> concat(break(""))
              |> concat(")")
-              |> group(:optimistic)
+              |> group(:inherit)
+              |> next_break_fits(:enabled)

            concat(nest(left_doc, 2, :break), right_doc)
          end
@@ -1324,11 +1214,13 @@ defmodule Code.Formatter do
          |> concat(args_doc)
          |> nest(2)
          |> concat(extra)
+          |> group()

        skip_parens? ->
          " "
          |> concat(args_doc)
          |> concat(extra)
+          |> group()

        true ->
          "("
@@ -1336,12 +1228,13 @@ defmodule Code.Formatter do
          |> nest(2, :break)
          |> concat(args_doc)
          |> concat(extra)
+          |> group()
      end

    if next_break_fits? do
-      {group(doc, :pessimistic), state}
+      {next_break_fits(doc, :disabled), state}
    else
-      {group(doc), state}
+      {doc, state}
    end
  end

@@ -1465,7 +1358,7 @@ defmodule Code.Formatter do
            metadata = [
              file: state.file,
              line: meta[:line],
-              sigil: String.to_unsafe_atom(name),
+              sigil: String.to_atom(name),
              modifiers: modifiers,
              opening_delimiter: opening_delimiter
            ]
@@ -1538,7 +1431,7 @@ defmodule Code.Formatter do
    {doc, state} = quoted_to_algebra(segment, :parens_arg, state)

    {spec, state} =
-      bitstring_spec_to_algebra(spec, state, state.migrate_bitstring_modifiers, :"::")
+      bitstring_spec_to_algebra(spec, state, state.normalize_bitstring_modifiers, :"::")

    spec = wrap_in_parens_if_inspected_atom(spec)
    spec = if i == last, do: bitstring_wrap_parens(spec, i, last), else: spec
@@ -1616,8 +1509,8 @@ defmodule Code.Formatter do
    {args_doc, _join, state} =
      args_to_algebra_with_comments(args, meta, false, :none, join, state, fun)

-    left_bracket = color_doc("[", :list, state.inspect_opts)
-    right_bracket = color_doc("]", :list, state.inspect_opts)
+    left_bracket = color("[", :list, state.inspect_opts)
+    right_bracket = color("]", :list, state.inspect_opts)

    {surround(left_bracket, args_doc, right_bracket), state}
  end
@@ -1649,8 +1542,8 @@ defmodule Code.Formatter do
  end

  defp do_map_to_algebra(name_doc, args_doc, state) do
-    name_doc = "%" |> concat(name_doc) |> concat("{") |> color_doc(:map, state.inspect_opts)
-    {surround(name_doc, args_doc, color_doc("}", :map, state.inspect_opts)), state}
+    name_doc = "%" |> concat(name_doc) |> concat("{") |> color(:map, state.inspect_opts)
+    {surround(name_doc, args_doc, color("}", :map, state.inspect_opts)), state}
  end

  defp tuple_to_algebra(meta, args, join, state) do
@@ -1660,8 +1553,8 @@ defmodule Code.Formatter do
    {args_doc, join, state} =
      args_to_algebra_with_comments(args, meta, false, :none, join, state, fun)

-    left_bracket = color_doc("{", :tuple, state.inspect_opts)
-    right_bracket = color_doc("}", :tuple, state.inspect_opts)
+    left_bracket = color("{", :tuple, state.inspect_opts)
+    right_bracket = color("}", :tuple, state.inspect_opts)

    if join == :flex_break do
      {left_bracket |> concat(args_doc) |> nest(1) |> concat(right_bracket) |> group(), state}
@@ -1671,11 +1564,16 @@ defmodule Code.Formatter do
  end

  defp atom_to_algebra(atom, _, inspect_opts) when atom in [true, false] do
-    Atom.to_string(atom) |> color_doc(:boolean, inspect_opts)
+    Atom.to_string(atom) |> color(:boolean, inspect_opts)
  end

  defp atom_to_algebra(nil, _, inspect_opts) do
-    Atom.to_string(nil) |> color_doc(nil, inspect_opts)
+    Atom.to_string(nil) |> color(nil, inspect_opts)
+  end
+
+  # TODO: Remove this clause in v1.18 when we no longer quote operator :..//
+  defp atom_to_algebra(:"..//", _, inspect_opts) do
+    string(":\"..//\"") |> color(:atom, inspect_opts)
  end

  defp atom_to_algebra(:\\, meta, inspect_opts) do
@@ -1688,7 +1586,7 @@ defmodule Code.Formatter do
        _ -> ":\\\\"
      end

-    string(string) |> color_doc(:atom, inspect_opts)
+    string(string) |> color(:atom, inspect_opts)
  end

  defp atom_to_algebra(atom, _, inspect_opts) do
@@ -1701,10 +1599,10 @@ defmodule Code.Formatter do
        [?:, ?", String.replace(string, "\"", "\\\""), ?"]
      end

-    iodata |> IO.iodata_to_binary() |> string() |> color_doc(:atom, inspect_opts)
+    iodata |> IO.iodata_to_binary() |> string() |> color(:atom, inspect_opts)
  end

-  defp integer_to_algebra(text, inspect_opts) do
+  defp integer_to_algebra(text, inspect_otps) do
    case text do
      <<?0, ?x, rest::binary>> ->
        "0x" <> String.upcase(rest)
@@ -1718,15 +1616,15 @@ defmodule Code.Formatter do
      decimal ->
        insert_underscores(decimal)
    end
-    |> color_doc(:number, inspect_opts)
+    |> color(:number, inspect_otps)
  end

-  defp float_to_algebra(text, inspect_opts) do
+  defp float_to_algebra(text, inspect_otps) do
    [int_part, decimal_part] = :binary.split(text, ".")
    decimal_part = String.downcase(decimal_part)

    string = insert_underscores(int_part) <> "." <> decimal_part
-    color_doc(string, :number, inspect_opts)
+    color(string, :number, inspect_otps)
  end

  defp insert_underscores("-" <> digits) do
@@ -1807,17 +1705,10 @@ defmodule Code.Formatter do

      doc =
        case args do
-          [_ | _] ->
-            concat_to_last_group(doc, ",")
-
-          [] when last_arg_mode == :force_comma ->
-            concat_to_last_group(doc, ",")
-
-          [] when last_arg_mode == :next_break_fits ->
-            doc |> ungroup_if_group() |> group(:optimistic)
-
-          [] when last_arg_mode == :none ->
-            doc
+          [_ | _] -> concat_to_last_group(doc, ",")
+          [] when last_arg_mode == :force_comma -> concat_to_last_group(doc, ",")
+          [] when last_arg_mode == :next_break_fits -> next_break_fits(doc, :enabled)
+          [] when last_arg_mode == :none -> doc
        end

      {{doc, @empty, 1}, state}
@@ -2335,14 +2226,11 @@ defmodule Code.Formatter do
  defp with_next_break_fits(condition, doc, fun) do
    if condition do
      doc
-      |> group(:optimistic)
+      |> next_break_fits(:enabled)
      |> fun.()
-      |> group(:pessimistic)
+      |> next_break_fits(:disabled)
    else
-      doc
-      |> group()
-      |> fun.()
-      |> group()
+      fun.(doc)
    end
  end

@@ -2501,24 +2389,20 @@ defmodule Code.Formatter do
    meta[:closing][:line] || @min_line
  end

-  defp escape_atom(string, char) do
-    String.replace(string, <<char>>, <<?\\, char>>)
-  end
-
  ## Algebra helpers

  # Relying on the inner document is brittle and error prone.
  # It would be best if we had a mechanism to apply this.
-  defp concat_to_last_group([left | right], concat) do
-    [left | concat_to_last_group(right, concat)]
+  defp concat_to_last_group({:doc_cons, left, right}, concat) do
+    {:doc_cons, left, concat_to_last_group(right, concat)}
  end

  defp concat_to_last_group({:doc_group, group, mode}, concat) do
-    {:doc_group, concat(group, concat), mode}
+    {:doc_group, {:doc_cons, group, concat}, mode}
  end

  defp concat_to_last_group(other, concat) do
-    concat(other, concat)
+    {:doc_cons, other, concat}
  end

  defp ungroup_if_group({:doc_group, group, _mode}), do: group
@@ -2550,7 +2434,7 @@ defmodule Code.Formatter do
  end

  defp get_charlist_quotes(:heredoc, state) do
-    if state.migrate_charlists_as_sigils do
+    if state.normalize_charlists_as_sigils do
      {@sigil_c_heredoc, @double_heredoc}
    else
      {@single_heredoc, @single_heredoc}
@@ -2559,7 +2443,7 @@ defmodule Code.Formatter do

  defp get_charlist_quotes({:regular, chunks}, state) do
    cond do
-      !state.migrate_charlists_as_sigils -> {@single_quote, @single_quote}
+      !state.normalize_charlists_as_sigils -> {@single_quote, @single_quote}
      Enum.any?(chunks, &has_double_quote?/1) -> {@sigil_c_single, @single_quote}
      true -> {@sigil_c_double, @double_quote}
    end
@@ -2568,46 +2452,4 @@ defmodule Code.Formatter do
  defp has_double_quote?(chunk) do
    is_binary(chunk) and chunk =~ @double_quote
  end
-
-  # Migration rewrites
-
-  @bool_operators [
-    :>,
-    :>=,
-    :<,
-    :<=,
-    :in
-  ]
-  @guards [
-    :is_atom,
-    :is_boolean,
-    :is_nil,
-    :is_number,
-    :is_integer,
-    :is_float,
-    :is_binary,
-    :is_map,
-    :is_struct,
-    :is_non_struct_map,
-    :is_exception,
-    :is_list,
-    :is_tuple,
-    :is_function,
-    :is_reference,
-    :is_pid,
-    :is_port
-  ]
-
-  defp negate_condition(condition) do
-    case condition do
-      {neg, _, [condition]} when neg in [:!, :not] -> condition
-      {op, _, [_, _]} when op in @bool_operators -> {:not, [], [condition]}
-      {guard, _, [_ | _]} when guard in @guards -> {:not, [], [condition]}
-      {:==, meta, [left, right]} -> {:!=, meta, [left, right]}
-      {:===, meta, [left, right]} -> {:!==, meta, [left, right]}
-      {:!=, meta, [left, right]} -> {:==, meta, [left, right]}
-      {:!==, meta, [left, right]} -> {:===, meta, [left, right]}
-      _ -> {:!, [], [condition]}
-    end
-  end
 end
@@ -1,6 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-
 defmodule Code.Fragment do
  @moduledoc """
  This module provides conveniences for analyzing fragments of
@@ -11,61 +8,6 @@ defmodule Code.Fragment do

  @type position :: {line :: pos_integer(), column :: pos_integer()}

-  @typedoc """
-  Options for cursor context functions.
-
-  Currently, these options are not used but reserved for future extensibility.
-  """
-  @type cursor_opts :: []
-
-  @typedoc """
-  Options for converting code fragments to quoted expressions.
-  """
-  @type container_cursor_to_quoted_opts :: [
-          file: String.t(),
-          line: pos_integer(),
-          column: pos_integer(),
-          columns: boolean(),
-          token_metadata: boolean(),
-          literal_encoder: (term(), Macro.metadata() -> {:ok, Macro.t()} | {:error, binary()}),
-          preserve_sigils: boolean(),
-          trailing_fragment: String.t()
-        ]
-
-  @doc ~S"""
-  Returns the list of lines in the given string, preserving their line endings.
-
-  Only the line endings recognized by the Elixir compiler are
-  considered, namely `\r\n` and `\n`. If you would like to retrieve
-  lines without their line endings, use `String.split(string, ["\r\n", "\n"])`.
-
-  ## Examples
-
-      iex> Code.Fragment.lines("foo\r\nbar\r\nbaz")
-      ["foo\r\n", "bar\r\n", "baz"]
-
-      iex> Code.Fragment.lines("foo\nbar\nbaz")
-      ["foo\n", "bar\n", "baz"]
-
-      iex> Code.Fragment.lines("")
-      [""]
-
-  """
-  @doc since: "1.19.0"
-  @spec lines(String.t()) :: [String.t()]
-  def lines(string) do
-    lines(string, <<>>)
-  end
-
-  defp lines(<<?\n, rest::binary>>, acc),
-    do: [<<acc::binary, ?\n>> | lines(rest, <<>>)]
-
-  defp lines(<<char, rest::binary>>, acc),
-    do: lines(rest, <<acc::binary, char>>)
-
-  defp lines(<<>>, acc),
-    do: [acc]
-
  @doc """
  Receives a string and returns the cursor context.

@@ -101,9 +43,6 @@ defmodule Code.Fragment do
      or `{:local_or_var, charlist}` and `charlist` is a static part
      Examples are `__MODULE__.Submodule` or `@hello.Submodule`

-    * `{:block_keyword_or_binary_operator, charlist}` - may be a block keyword (do, end, after,
-      catch, else, rescue) or a binary operator
-
    * `{:dot, inside_dot, charlist}` - the context is a dot
      where `inside_dot` is either a `{:var, charlist}`, `{:alias, charlist}`,
      `{:module_attribute, charlist}`, `{:unquoted_atom, charlist}` or a `dot`
@@ -142,9 +81,6 @@ defmodule Code.Fragment do
    * `{:anonymous_call, inside_caller}` - the context is an anonymous
      call, such as `fun.(` and `@fun.(`.

-    * `{:capture_arg, charlist}` - the context is a capture argument,
-      such as `&1`
-
    * `{:module_attribute, charlist}` - the context is a module attribute,
      such as `@hello_wor`

@@ -162,8 +98,8 @@ defmodule Code.Fragment do
    * `:none` - no context possible

    * `{:sigil, charlist}` - the context is a sigil. It may be either the beginning
-      of a sigil, such as `~` or `~s`. Operators starting with `~`, such as
-      `~>` and `~>>`, are returned as :operator contexts
+      of a sigil, such as `~` or `~s`, or an operator starting with `~`, such as
+      `~>` and `~>>`

    * `{:struct, inside_struct}` - the context is a struct, such as `%`, `%UR` or `%URI`.
      `inside_struct` can either be a `charlist` in case of a static alias or an
@@ -197,10 +133,9 @@ defmodule Code.Fragment do
  references, and more.
  """
  @doc since: "1.13.0"
-  @spec cursor_context(List.Chars.t(), cursor_opts()) ::
+  @spec cursor_context(List.Chars.t(), keyword()) ::
          {:alias, charlist}
          | {:alias, inside_alias, charlist}
-          | {:block_keyword_or_binary_operator, charlist}
          | {:dot, inside_dot, charlist}
          | {:dot_arity, inside_dot, charlist}
          | {:dot_call, inside_dot, charlist}
@@ -209,7 +144,6 @@ defmodule Code.Fragment do
          | {:local_arity, charlist}
          | {:local_call, charlist}
          | {:anonymous_call, inside_caller}
-          | {:capture_arg, charlist}
          | {:module_attribute, charlist}
          | {:operator, charlist}
          | {:operator_arity, charlist}
@@ -251,15 +185,15 @@ defmodule Code.Fragment do
    cursor_context(to_charlist(other), opts)
  end

-  @operators ~c"\\<>+-*/:=|&~^%!$"
-  @starting_punctuation ~c",([{;"
-  @closing_punctuation ~c")]}\"'"
+  @operators ~c"\\<>+-*/:=|&~^%!"
+  @starter_punctuation ~c",([{;"
+  @non_starter_punctuation ~c")]}\"'.$"
  @space ~c"\t\s"
  @trailing_identifier ~c"?!"
  @tilde_op_prefix ~c"<=~"

  @non_identifier @trailing_identifier ++
-                    @operators ++ @starting_punctuation ++ @closing_punctuation ++ @space ++ [?.]
+                    @operators ++ @starter_punctuation ++ @non_starter_punctuation ++ @space

  @textual_operators ~w(when not and or in)c
  @keywords ~w(do end after else catch rescue fn true false nil)c
@@ -289,11 +223,11 @@ defmodule Code.Fragment do
      # A local arity definition
      [?/ | rest] -> arity_to_cursor_context(strip_spaces(rest, spaces + 1))
      # Starting a new expression
-      [h | _] when h in @starting_punctuation -> {:expr, 0}
-      # It is keyword, binary operator, a local or remote call without parens
-      rest when spaces > 0 -> closing_or_call_to_cursor_context({rest, spaces})
+      [h | _] when h in @starter_punctuation -> {:expr, 0}
+      # It is a local or remote call without parens
+      rest when spaces > 0 -> call_to_cursor_context({rest, spaces})
      # It is an identifier
-      _ -> identifier_to_cursor_context(reverse, spaces, false)
+      _ -> identifier_to_cursor_context(reverse, 0, false)
    end
  end

@@ -308,8 +242,7 @@ defmodule Code.Fragment do
      {{:local_or_var, acc}, count} -> {{:local_arity, acc}, count}
      {{:dot, base, acc}, count} -> {{:dot_arity, base, acc}, count}
      {{:operator, acc}, count} -> {{:operator_arity, acc}, count}
-      {{:sigil, _}, _} -> {:none, 0}
-      {_, _} -> {{:operator, ~c"/"}, 1}
+      {_, _} -> {:none, 0}
    end
  end

@@ -333,16 +266,8 @@ defmodule Code.Fragment do
    end
  end

-  defp closing_or_call_to_cursor_context({reverse, spaces}) do
-    if closing?(reverse) do
-      {{:block_keyword_or_binary_operator, ~c""}, 0}
-    else
-      call_to_cursor_context({reverse, spaces})
-    end
-  end
-
  defp identifier_to_cursor_context([?., ?., ?: | _], n, _), do: {{:unquoted_atom, ~c".."}, n + 3}
-  defp identifier_to_cursor_context([?., ?., ?. | _], n, _), do: {{:operator, ~c"..."}, n + 3}
+  defp identifier_to_cursor_context([?., ?., ?. | _], n, _), do: {{:local_or_var, ~c"..."}, n + 3}
  defp identifier_to_cursor_context([?., ?: | _], n, _), do: {{:unquoted_atom, ~c"."}, n + 2}
  defp identifier_to_cursor_context([?., ?. | _], n, _), do: {{:operator, ~c".."}, n + 2}

@@ -392,42 +317,12 @@ defmodule Code.Fragment do
          {~c"." ++ rest, count} when rest == [] or hd(rest) != ?. ->
            dot(rest, count + 1, acc)

-          {rest, rest_count} ->
-            response =
-              if rest_count > count and closing?(rest),
-                do: :block_keyword_or_binary_operator,
-                else: :local_or_var
-
-            {{response, acc}, count}
+          _ ->
+            {{:local_or_var, acc}, count}
        end
-
-      {:capture_arg, acc, count} ->
-        {{:capture_arg, acc}, count}
    end
  end

-  # If it is a closing punctuation
-  defp closing?([h | _]) when h in @closing_punctuation, do: true
-  # Closing bitstring (but deal with operators)
-  defp closing?([?>, ?> | rest]), do: rest == [] or hd(rest) not in [?>, ?~]
-  # Keywords
-  defp closing?(rest) do
-    case split_non_identifier(rest, []) do
-      {~c"nil", _} -> true
-      {~c"true", _} -> true
-      {~c"false", _} -> true
-      {[digit | _], _} when digit in ?0..?9 -> true
-      {[upper | _], _} when upper in ?A..?Z -> true
-      {[_ | _], [?: | rest]} -> rest == [] or hd(rest) != ?:
-      {_, _} -> false
-    end
-  end
-
-  defp split_non_identifier([h | t], acc) when h not in @non_identifier,
-    do: split_non_identifier(t, [h | acc])
-
-  defp split_non_identifier(rest, acc), do: {acc, rest}
-
  defp identifier([?? | rest], count), do: check_identifier(rest, count + 1, [??])
  defp identifier([?! | rest], count), do: check_identifier(rest, count + 1, [?!])
  defp identifier(rest, count), do: check_identifier(rest, count, [])
@@ -467,14 +362,6 @@ defmodule Code.Fragment do
    :none
  end

-  defp rest_identifier([?& | tail] = rest, count, acc) when tail == [] or hd(tail) != ?& do
-    if Enum.all?(acc, &(&1 in ?0..?9)) do
-      {:capture_arg, [?& | acc], count + 1}
-    else
-      tokenize_identifier(rest, count, acc)
-    end
-  end
-
  defp rest_identifier(rest, count, acc) do
    tokenize_identifier(rest, count, acc)
  end
@@ -662,7 +549,7 @@ defmodule Code.Fragment do
      iex> Code.Fragment.surround_context("foo", {1, 1})
      %{begin: {1, 1}, context: {:local_or_var, ~c"foo"}, end: {1, 4}}

-  ## Differences from `cursor_context/2`
+  ## Differences to `cursor_context/2`

  Because `surround_context/3` attempts to capture complex expressions,
  it has some differences to `cursor_context/2`:
@@ -675,13 +562,13 @@ defmodule Code.Fragment do
      `local_call`/`local_arity` and `local_or_var`, since the latter can
      be a local or variable

-    * `@` when not followed by any identifier is returned as `{:operator, ~c"@"}`
-      (in contrast to `{:module_attribute, ~c""}` in `cursor_context/2`)
+    * `@` when not followed by any identifier is returned as `{:operator, '@'}`
+      (in contrast to `{:module_attribute, ''}` in `cursor_context/2`

-    * This function never returns empty sigils `{:sigil, ~c""}` or empty structs
-      `{:struct, ~c""}` as context
+    * This function never returns empty sigils `{:sigil, ''}` or empty structs
+      `{:struct, ''}` as context

-    * This function returns keywords as `{:keyword, ~c"do"}`
+    * This function returns keywords as `{:keyword, 'do'}`

    * This function never returns `:expr`

@@ -689,7 +576,7 @@ defmodule Code.Fragment do
  of examples and their return values.
  """
  @doc since: "1.13.0"
-  @spec surround_context(List.Chars.t(), position(), cursor_opts()) ::
+  @spec surround_context(List.Chars.t(), position(), keyword()) ::
          %{begin: position, end: position, context: context} | :none
        when context:
               {:alias, charlist}
@@ -703,9 +590,7 @@ defmodule Code.Fragment do
               | {:sigil, charlist}
               | {:struct, inside_struct}
               | {:unquoted_atom, charlist}
-               | {:keyword, charlist}
-               | {:key, charlist}
-               | {:capture_arg, charlist},
+               | {:keyword, charlist},
             inside_dot:
               {:alias, charlist}
               | {:alias, inside_alias, charlist}
@@ -755,16 +640,7 @@ defmodule Code.Fragment do
        maybe_operator(reversed_pre, post, line, opts)

      {:identifier, reversed_post, rest} ->
-        {keyword_key?, rest} =
-          case rest do
-            [?: | tail] when tail == [] or hd(tail) in @space ->
-              {true, rest}
-
-            _ ->
-              {rest, _} = strip_spaces(rest, 0)
-              {false, rest}
-          end
-
+        {rest, _} = strip_spaces(rest, 0)
        reversed = reversed_post ++ reversed_pre

        case codepoint_cursor_context(reversed, opts) do
@@ -780,9 +656,6 @@ defmodule Code.Fragment do
          {{:dot, _, [_ | _]} = dot, offset} ->
            build_surround(dot, reversed, line, offset)

-          {{:local_or_var, acc}, offset} when keyword_key? ->
-            build_surround({:key, acc}, reversed, line, offset)
-
          {{:local_or_var, acc}, offset} when hd(rest) == ?( ->
            build_surround({:local_call, acc}, reversed, line, offset)

@@ -798,12 +671,6 @@ defmodule Code.Fragment do
          {{:local_or_var, acc}, offset} ->
            build_surround({:local_or_var, acc}, reversed, line, offset)

-          {{:block_keyword_or_binary_operator, acc}, offset} when acc in @textual_operators ->
-            build_surround({:operator, acc}, reversed, line, offset)
-
-          {{:block_keyword_or_binary_operator, acc}, offset} when acc in @keywords ->
-            build_surround({:keyword, acc}, reversed, line, offset)
-
          {{:module_attribute, ~c""}, offset} ->
            build_surround({:operator, ~c"@"}, reversed, line, offset)

@@ -816,9 +683,6 @@ defmodule Code.Fragment do
          {{:unquoted_atom, acc}, offset} ->
            build_surround({:unquoted_atom, acc}, reversed, line, offset)

-          {{:capture_arg, acc}, offset} ->
-            build_surround({:capture_arg, acc}, reversed, line, offset)
-
          _ ->
            maybe_operator(reversed_pre, post, line, opts)
        end
@@ -851,16 +715,6 @@ defmodule Code.Fragment do
        reversed = reversed_post ++ reversed_pre

        case codepoint_cursor_context(reversed, opts) do
-          {{:operator, ~c"&"}, offset} when hd(rest) in ?0..?9 ->
-            arg = Enum.take_while(rest, &(&1 in ?0..?9))
-
-            build_surround(
-              {:capture_arg, ~c"&" ++ arg},
-              :lists.reverse(arg, reversed),
-              line,
-              offset + length(arg)
-            )
-
          {{:operator, acc}, offset} ->
            build_surround({:operator, acc}, reversed, line, offset)

@@ -1207,23 +1061,16 @@ defmodule Code.Fragment do
      iex> Code.Fragment.container_cursor_to_quoted("foo +")
      {:ok, {:+, [line: 1], [{:foo, [line: 1], nil}, {:__cursor__, [line: 1], []}]}}

-  In order to parse the left-side of `->` properly, which appears both
-  in anonymous functions and do-end blocks, the trailing fragment option
-  must be given with the rest of the contents:
-
-      iex> Code.Fragment.container_cursor_to_quoted("fn x", trailing_fragment: " -> :ok end")
-      {:ok, {:fn, [line: 1], [{:->, [line: 1], [[{:__cursor__, [line: 1], []}], :ok]}]}}
-
  ## Options

    * `:file` - the filename to be reported in case of parsing errors.
      Defaults to `"nofile"`.

    * `:line` - the starting line of the string being parsed.
-      Defaults to `1`.
+      Defaults to 1.

    * `:column` - the starting column of the string being parsed.
-      Defaults to `1`.
+      Defaults to 1.

    * `:columns` - when `true`, attach a `:column` key to the quoted
      metadata. Defaults to `false`.
@@ -1236,151 +1083,46 @@ defmodule Code.Fragment do
    * `:literal_encoder` - a function to encode literals in the AST.
      See the documentation for `Code.string_to_quoted/2` for more information.

-    * `:trailing_fragment` (since v1.18.0) - the rest of the contents after
-      the cursor. This is necessary to correctly complete anonymous functions
-      and the left-hand side of `->`
-
-    * `:preserve_sigils` (since v1.20.0) - preserve sigil cursor location
-      (see "Tracking sigils" section below)
-
-  ## Tracking sigils
-
-  The `:preserve_sigils` option can be used to track cursor positions inside
-  a sigil.
-
-  If the sigil is terminated abruptly, the `sigil_*` call will have the cursor
-  as the second argument:
-
-      iex> Code.Fragment.container_cursor_to_quoted("~r/foo", preserve_sigils: true)
-      {:ok,
-      {:sigil_r, [delimiter: "/", line: 1],
-        [{:<<>>, [line: 1], ["foo"]}, {:__cursor__, [line: 1, column: 7], []}]}}
-
-  In case the sigil is completed and has zero or more modifiers, the cursor will
-  be nested in the list, with all previous delimiters specified:
-
-      iex> Code.Fragment.container_cursor_to_quoted("~r/foo/i", preserve_sigils: true)
-      {:ok,
-       {:sigil_r, [delimiter: "/", line: 1],
-        [{:<<>>, [line: 1], ["foo"]}, [105, {:__cursor__, [line: 1, column: 9], []}]]}}
-
-  If the cursor is after the sigil, then it is discarded as everything else:
-
-      iex> Code.Fragment.container_cursor_to_quoted("~r/foo/i ", preserve_sigils: true)
-      {:ok, {:__cursor__, [line: 1], []}}
  """
  @doc since: "1.13.0"
-  @spec container_cursor_to_quoted(List.Chars.t(), container_cursor_to_quoted_opts()) ::
+  @spec container_cursor_to_quoted(List.Chars.t(), keyword()) ::
          {:ok, Macro.t()} | {:error, {location :: keyword, binary | {binary, binary}, binary}}
  def container_cursor_to_quoted(fragment, opts \\ []) do
-    {trailing_fragment, opts} = Keyword.pop(opts, :trailing_fragment)
-    {preserve_sigils?, opts} = Keyword.pop(opts, :preserve_sigils, false)
    opts = Keyword.take(opts, [:columns, :token_metadata, :literal_encoder])
-    opts = [check_terminators: {:cursor, preserve_sigils?, []}] ++ opts
+    opts = [cursor_completion: true, emit_warnings: false] ++ opts

    file = Keyword.get(opts, :file, "nofile")
    line = Keyword.get(opts, :line, 1)
    column = Keyword.get(opts, :column, 1)

    case :elixir_tokenizer.tokenize(to_charlist(fragment), line, column, opts) do
-      {:ok, line, column, _warnings, rev_tokens, rev_terminators}
-      when trailing_fragment == nil ->
-        {rev_tokens, rev_terminators} =
-          with [close, open, {_, _, :__cursor__} = cursor | rev_tokens] <- rev_tokens,
-               {_, [_ | after_fn]} <- Enum.split_while(rev_terminators, &(elem(&1, 0) != :fn)),
-               true <- maybe_missing_stab?(rev_tokens, false),
-               [_ | rev_tokens] <- Enum.drop_while(rev_tokens, &(elem(&1, 0) != :fn)) do
-            {[close, open, cursor | rev_tokens], after_fn}
-          else
-            _ -> {rev_tokens, rev_terminators}
-          end
-
-        tokens = reverse_tokens(line, column, rev_tokens, rev_terminators)
-
-        with {:ok, forms, _warnings} <- :elixir.tokens_to_quoted(tokens, file, opts) do
-          {:ok, forms}
-        end
-
      {:ok, line, column, _warnings, rev_tokens, rev_terminators} ->
-        tokens =
-          with {before_start, [_ | _] = after_start} <-
-                 Enum.split_while(rev_terminators, &(elem(&1, 0) not in [:do, :fn])),
-               true <- maybe_missing_stab?(rev_tokens, true),
-               opts =
-                 Keyword.put(opts, :check_terminators, {:cursor, false, before_start}),
-               {:error, {meta, _, ~c"end"}, _rest, _warnings, trailing_rev_tokens} <-
-                 :elixir_tokenizer.tokenize(to_charlist(trailing_fragment), line, column, opts) do
-            trailing_tokens =
-              reverse_tokens(meta[:line], meta[:column], trailing_rev_tokens, after_start)
+        tokens = :lists.reverse(rev_tokens, rev_terminators)

-            # If the cursor has its own line, then we do not trim new lines trailing tokens.
-            # Otherwise we want to drop any newline so we drop the next tokens after eol.
-            trailing_tokens =
-              case rev_tokens do
-                [_close, _open, {_, _, :__cursor__}, {:eol, _} | _] -> trailing_tokens
-                _ -> Enum.drop_while(trailing_tokens, &match?({:eol, _}, &1))
-              end
+        case :elixir.tokens_to_quoted(tokens, file, opts) do
+          {:ok, ast} ->
+            {:ok, ast}

-            Enum.reverse(rev_tokens, drop_tokens(trailing_tokens, 0))
-          else
-            _ -> reverse_tokens(line, column, rev_tokens, rev_terminators)
-          end
+          {:error, error} ->
+            # In case parsing fails, we give it another shot but handling fn/do/else/catch/rescue/after.
+            tokens =
+              :lists.reverse(
+                rev_tokens,
+                [{:stab_op, {line, column, nil}, :->}, {nil, {line, column + 2, nil}}] ++
+                  Enum.map(rev_terminators, fn tuple ->
+                    {line, column, info} = elem(tuple, 1)
+                    put_elem(tuple, 1, {line, column + 5, info})
+                  end)
+              )

-        with {:ok, forms, _warnings} <- :elixir.tokens_to_quoted(tokens, file, opts) do
-          {:ok, forms}
+            case :elixir.tokens_to_quoted(tokens, file, opts) do
+              {:ok, ast} -> {:ok, ast}
+              {:error, _} -> {:error, error}
+            end
        end

      {:error, info, _rest, _warnings, _so_far} ->
-        {:error, :elixir_tokenizer.format_error(info)}
+        {:error, :elixir.format_token_error(info)}
    end
  end
-
-  defp reverse_tokens(line, column, tokens, terminators) do
-    {terminators, _} =
-      Enum.map_reduce(terminators, column, fn {start, _, _}, column ->
-        atom = :elixir_tokenizer.terminator(start)
-
-        {{atom, {line, column, nil}}, column + length(Atom.to_charlist(atom))}
-      end)
-
-    Enum.reverse(tokens, terminators)
-  end
-
-  # Otherwise we drop all tokens, trying to build a minimal AST
-  # for cursor completion.
-  defp drop_tokens([{:"}", _} | _] = tokens, 0), do: tokens
-  defp drop_tokens([{:"]", _} | _] = tokens, 0), do: tokens
-  defp drop_tokens([{:")", _} | _] = tokens, 0), do: tokens
-  defp drop_tokens([{:">>", _} | _] = tokens, 0), do: tokens
-  defp drop_tokens([{:end, _} | _] = tokens, 0), do: tokens
-  defp drop_tokens([{:",", _} | _] = tokens, 0), do: tokens
-  defp drop_tokens([{:";", _} | _] = tokens, 0), do: tokens
-  defp drop_tokens([{:eol, _} | _] = tokens, 0), do: tokens
-  defp drop_tokens([{:stab_op, _, :->} | _] = tokens, 0), do: tokens
-
-  defp drop_tokens([{:"}", _} | tokens], counter), do: drop_tokens(tokens, counter - 1)
-  defp drop_tokens([{:"]", _} | tokens], counter), do: drop_tokens(tokens, counter - 1)
-  defp drop_tokens([{:")", _} | tokens], counter), do: drop_tokens(tokens, counter - 1)
-  defp drop_tokens([{:">>", _} | tokens], counter), do: drop_tokens(tokens, counter - 1)
-  defp drop_tokens([{:end, _} | tokens], counter), do: drop_tokens(tokens, counter - 1)
-
-  defp drop_tokens([{:"{", _} | tokens], counter), do: drop_tokens(tokens, counter + 1)
-  defp drop_tokens([{:"[", _} | tokens], counter), do: drop_tokens(tokens, counter + 1)
-  defp drop_tokens([{:"(", _} | tokens], counter), do: drop_tokens(tokens, counter + 1)
-  defp drop_tokens([{:"<<", _} | tokens], counter), do: drop_tokens(tokens, counter + 1)
-  defp drop_tokens([{:fn, _} | tokens], counter), do: drop_tokens(tokens, counter + 1)
-  defp drop_tokens([{:do, _} | tokens], counter), do: drop_tokens(tokens, counter + 1)
-
-  defp drop_tokens([_ | tokens], counter), do: drop_tokens(tokens, counter)
-  defp drop_tokens([], _counter), do: []
-
-  defp maybe_missing_stab?([{:after, _} | _], _stab_choice?), do: true
-  defp maybe_missing_stab?([{:do, _} | _], _stab_choice?), do: true
-  defp maybe_missing_stab?([{:fn, _} | _], _stab_choice?), do: true
-  defp maybe_missing_stab?([{:else, _} | _], _stab_choice?), do: true
-  defp maybe_missing_stab?([{:catch, _} | _], _stab_choice?), do: true
-  defp maybe_missing_stab?([{:rescue, _} | _], _stab_choice?), do: true
-  defp maybe_missing_stab?([{:stab_op, _, :->} | _], stab_choice?), do: stab_choice?
-  defp maybe_missing_stab?([_ | tail], stab_choice?), do: maybe_missing_stab?(tail, stab_choice?)
-  defp maybe_missing_stab?([], _stab_choice?), do: false
 end
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule Code.Identifier do
  @moduledoc false

@@ -65,7 +61,7 @@ defmodule Code.Identifier do
    with "-" <> rest <- Atom.to_string(atom),
         [trailing | reversed] = rest |> String.split("/") |> Enum.reverse(),
         [arity, _inner, _count, ""] <- String.split(trailing, "-") do
-      {reversed |> Enum.reverse() |> Enum.join("/") |> String.to_unsafe_atom(), arity}
+      {reversed |> Enum.reverse() |> Enum.join("/") |> String.to_atom(), arity}
    else
      _ -> :error
    end
@@ -75,11 +71,11 @@ defmodule Code.Identifier do
  Escapes the given identifier.
  """
  @spec escape(binary(), char() | nil, :infinity | non_neg_integer, (char() -> iolist() | false)) ::
-          {escaped :: binary(), remaining :: binary()}
+          {escaped :: iolist(), remaining :: binary()}
  def escape(binary, char, limit \\ :infinity, fun \\ &escape_map/1)
-      when (is_binary(binary) and ((char in 0..0x10FFFF or is_nil(char)) and limit == :infinity)) or
+      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)
+    escape(binary, char, limit, [], fun)
  end

  defp escape(<<_, _::binary>> = binary, _char, 0, acc, _fun) do
@@ -87,96 +83,64 @@ defmodule Code.Identifier do
  end

  defp escape(<<char, t::binary>>, char, count, acc, fun) do
-    escape(t, char, decrement(count), <<acc::binary, ?\\, char>>, fun)
+    escape(t, char, decrement(count), [acc | [?\\, char]], fun)
  end

  defp escape(<<?#, ?{, t::binary>>, char, count, acc, fun) do
-    escape(t, char, decrement(count), <<acc::binary, ?\\, ?#, ?{>>, fun)
+    escape(t, char, decrement(count), [acc | [?\\, ?#, ?{]], fun)
  end

  defp escape(<<h::utf8, t::binary>>, char, count, acc, fun) do
-    if value = fun.(h) do
-      value = IO.iodata_to_binary(value)
-      escape(t, char, decrement(count), <<acc::binary, value::binary>>, fun)
-    else
-      escape(t, char, decrement(count), escape_char(h, acc), fun)
-    end
+    escaped = if value = fun.(h), do: value, else: escape_char(h)
+    escape(t, char, decrement(count), [acc | escaped], fun)
  end

  defp escape(<<a::4, b::4, t::binary>>, char, count, acc, fun) do
-    escape(t, char, decrement(count), <<acc::binary, ?\\, ?x, to_hex(a), to_hex(b)>>, fun)
+    escape(t, char, decrement(count), [acc | [?\\, ?x, to_hex(a), to_hex(b)]], fun)
  end

  defp escape(<<>>, _char, _count, acc, _fun) do
    {acc, <<>>}
  end

-  defp escape_char(0, acc), do: <<acc::binary, ?\\, ?0>>
+  defp escape_char(0), do: [?\\, ?0]

-  defp escape_char(char, acc)
-       # Some characters that are confusing (zero-width / alternative spaces) are displayed
-       # using their unicode representation:
-       # https://en.wikipedia.org/wiki/Universal_Character_Set_characters#Special-purpose_characters
+  @escaped_bom :binary.bin_to_list("\\uFEFF")
+  defp escape_char(65279), do: @escaped_bom

-       # BOM
-       when char == 0xFEFF
-       # Mathematical invisibles
-       when char in 0x2061..0x2064
-       # Bidirectional neutral
-       when char in [0x061C, 0x200E, 0x200F]
-       # Bidirectional general (source of vulnerabilities)
-       when char in 0x202A..0x202E
-       when char in 0x2066..0x2069
-       # Interlinear annotations
-       when char in 0xFFF9..0xFFFC
-       # Zero-width joiners and non-joiners
-       when char in [0x200C, 0x200D, 0x034F]
-       # Non-break space / zero-width space
-       when char in [0x00A0, 0x200B, 0x2060]
-       # Line/paragraph separators
-       when char in [0x2028, 0x2029]
-       # Spaces
-       when char in 0x2000..0x200A
-       when char == 0x205F do
-    <<a::4, b::4, c::4, d::4>> = <<char::16>>
-    <<acc::binary, ?\\, ?u, to_hex(a), to_hex(b), to_hex(c), to_hex(d)>>
-  end
-
-  defp escape_char(char, acc)
+  defp escape_char(char)
       when char in 0x20..0x7E
       when char in 0xA0..0xD7FF
       when char in 0xE000..0xFFFD
       when char in 0x10000..0x10FFFF do
-    <<acc::binary, char::utf8>>
+    <<char::utf8>>
  end

-  defp escape_char(char, acc) when char < 0x80 do
+  defp escape_char(char) when char < 0x100 do
    <<a::4, b::4>> = <<char::8>>
-    <<acc::binary, ?\\, ?x, to_hex(a), to_hex(b)>>
+    [?\\, ?x, to_hex(a), to_hex(b)]
  end

-  defp escape_char(char, acc) when char < 0x10000 do
+  defp escape_char(char) when char < 0x10000 do
    <<a::4, b::4, c::4, d::4>> = <<char::16>>
-    <<acc::binary, ?\\, ?u, to_hex(a), to_hex(b), to_hex(c), to_hex(d)>>
+    [?\\, ?x, ?{, to_hex(a), to_hex(b), to_hex(c), to_hex(d), ?}]
  end

-  defp escape_char(char, acc) when char < 0x1000000 do
+  defp escape_char(char) when char < 0x1000000 do
    <<a::4, b::4, c::4, d::4, e::4, f::4>> = <<char::24>>
-
-    <<acc::binary, ?\\, ?u, ?{, to_hex(a), to_hex(b), to_hex(c), to_hex(d), to_hex(e), to_hex(f),
-      ?}>>
+    [?\\, ?x, ?{, to_hex(a), to_hex(b), to_hex(c), to_hex(d), to_hex(e), to_hex(f), ?}]
  end

-  defp escape_map(?\a), do: "\\a"
-  defp escape_map(?\b), do: "\\b"
-  defp escape_map(?\d), do: "\\d"
-  defp escape_map(?\e), do: "\\e"
-  defp escape_map(?\f), do: "\\f"
-  defp escape_map(?\n), do: "\\n"
-  defp escape_map(?\r), do: "\\r"
-  defp escape_map(?\t), do: "\\t"
-  defp escape_map(?\v), do: "\\v"
-  defp escape_map(?\\), do: "\\\\"
+  defp escape_map(?\a), do: [?\\, ?a]
+  defp escape_map(?\b), do: [?\\, ?b]
+  defp escape_map(?\d), do: [?\\, ?d]
+  defp escape_map(?\e), do: [?\\, ?e]
+  defp escape_map(?\f), do: [?\\, ?f]
+  defp escape_map(?\n), do: [?\\, ?n]
+  defp escape_map(?\r), do: [?\\, ?r]
+  defp escape_map(?\t), do: [?\\, ?t]
+  defp escape_map(?\v), do: [?\\, ?v]
+  defp escape_map(?\\), do: [?\\, ?\\]
  defp escape_map(_), do: false

  @compile {:inline, to_hex: 1, decrement: 1}
@@ -1,11 +1,6 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-
 defmodule Code.Normalizer do
  @moduledoc false

-  @do_end_keywords [:rescue, :catch, :else, :after]
-
  defguard is_literal(x)
           when is_integer(x) or
                  is_float(x) or
@@ -16,7 +11,6 @@ defmodule Code.Normalizer do
  Wraps literals in the quoted expression to conform to the AST format expected
  by the formatter.
  """
-  @spec normalize(Macro.t(), keyword()) :: Macro.t()
  def normalize(quoted, opts \\ []) do
    line = Keyword.get(opts, :line, nil)
    escape = Keyword.get(opts, :escape, true)
@@ -64,13 +58,13 @@ defmodule Code.Normalizer do
      {:.., meta, [left, right]}
    else
      step = do_normalize(step, state)
-      {:..//, meta, [left, right, step]}
+      {:"..//", meta, [left, right, step]}
    end
  end

  # Bit containers
  defp do_normalize({:<<>>, _, args} = quoted, state) when is_list(args) do
-    normalize_bitstring(quoted, state, state.escape)
+    normalize_bitstring(quoted, state)
  end

  # Atoms with interpolations
@@ -91,7 +85,13 @@ defmodule Code.Normalizer do
        normalize_literal(:utf8, [], state)
      end

-    string = normalize_bitstring(string, state, state.escape)
+    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

@@ -114,7 +114,6 @@ defmodule Code.Normalizer do
            end
        end)

-      parts = maybe_add_trailing_newline(call_meta, parts, state)
      {{:., dot_meta, [List, :to_charlist]}, call_meta, [parts]}
    else
      normalize_call(quoted, state)
@@ -127,13 +126,13 @@ defmodule Code.Normalizer do
    {:., 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. However, it should be escaped if applicable.
-  defp do_normalize({:., meta, [left, right]}, state) when is_atom(right) do
+  # 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})
-    right = maybe_escape_literal(right, state)

    {:., meta, [left, right]}
  end
@@ -175,18 +174,16 @@ defmodule Code.Normalizer do

  # Sigils
  defp do_normalize({sigil, meta, [{:<<>>, _, args} = string, modifiers]} = quoted, state)
-       when is_atom(sigil) and is_list(args) and is_list(modifiers) do
-    with "sigil_" <> _ <- Atom.to_string(sigil),
-         true <- binary_interpolated?(args),
-         true <- List.ascii_printable?(modifiers) do
-      meta =
-        meta
-        |> patch_meta_line(state.parent_meta)
-        |> Keyword.put_new(:delimiter, "\"")
+       when is_list(args) and is_atom(sigil) do
+    case Atom.to_string(sigil) do
+      "sigil_" <> _ ->
+        meta =
+          meta
+          |> patch_meta_line(state.parent_meta)
+          |> Keyword.put_new(:delimiter, "\"")
+
+        {sigil, meta, [do_normalize(string, %{state | parent_meta: meta}), modifiers]}

-      string = normalize_bitstring(string, %{state | parent_meta: meta}, false)
-      {sigil, meta, [string, modifiers]}
-    else
      _ ->
        normalize_call(quoted, state)
    end
@@ -267,7 +264,7 @@ defmodule Code.Normalizer do
          "Elixir." <> segments ->
            segments
            |> String.split(".")
-            |> Enum.map(&String.to_unsafe_atom/1)
+            |> Enum.map(&String.to_atom/1)
        end

      {:__aliases__, meta, segments}
@@ -291,18 +288,21 @@ defmodule Code.Normalizer do
  # Lists
  defp normalize_literal(list, meta, state) when is_list(list) do
    if list != [] and List.ascii_printable?(list) do
-      # It's a charlist, we normalize it as a ~C sigil
-      string =
+      # It's a charlist
+      list =
        if state.escape do
-          {iolist, _} = Code.Identifier.escape(IO.chardata_to_string(list), nil)
-          IO.iodata_to_binary(iolist)
+          {string, _} = Code.Identifier.escape(IO.chardata_to_string(list), nil)
+          IO.iodata_to_binary(string) |> to_charlist()
        else
-          List.to_string(list)
+          list
        end

-      meta = patch_meta_line([delimiter: "\""], state.parent_meta)
+      meta =
+        meta
+        |> Keyword.put_new(:delimiter, "'")
+        |> patch_meta_line(state.parent_meta)

-      {:sigil_c, meta, [{:<<>>, [], [string]}, []]}
+      {:__block__, meta, [list]}
    else
      meta =
        if line = state.parent_meta[:line] do
@@ -349,39 +349,28 @@ defmodule Code.Normalizer do
        args = normalize_args(args, %{state | parent_meta: meta})
        {form, meta, args}

-      Keyword.has_key?(meta, :do) and kw_blocks?(last) ->
+      Keyword.has_key?(meta, :do) or match?([{{:__block__, _, [:do]}, _} | _], last) ->
        # def foo do :ok end
        # def foo, do: :ok
        normalize_kw_blocks(form, meta, args, state)

-      match?([{:do, _} | _], last) and kw_blocks?(last) ->
+      match?([{:do, _} | _], last) and Keyword.keyword?(last) ->
        # Non normalized kw blocks
-        line = state.parent_meta[:line] || meta[:line]
+        line = state.parent_meta[:line]
        meta = meta ++ [do: [line: line], end: [line: line]]
        normalize_kw_blocks(form, meta, args, state)

      true ->
-        # The formatter renders do-end blocks from the meta alone
-        meta = Keyword.drop(meta, [:do, :end])
        args = normalize_args(args, %{state | parent_meta: meta})
        {last_arg, leading_args} = List.pop_at(args, -1, [])

        last_args =
          case last_arg do
-            {:__block__, _meta, [[{{:__block__, key_meta, _}, _} | _] = keyword]} ->
-              cond do
-                key_meta[:format] == :keyword ->
-                  [keyword]
-
-                block_keyword?(keyword) ->
-                  [
-                    Enum.map(keyword, fn {{:__block__, meta, args}, value} ->
-                      {{:__block__, [format: :keyword] ++ meta, args}, value}
-                    end)
-                  ]
-
-                true ->
-                  [last_arg]
+            {:__block__, _, [[{{:__block__, key_meta, _}, _} | _]] = last_args} ->
+              if key_meta[:format] == :keyword do
+                last_args
+              else
+                [last_arg]
              end

            [] ->
@@ -395,28 +384,11 @@ defmodule Code.Normalizer do
    end
  end

-  defp block_keyword?([{{:__block__, _, [key]}, _val} | tail]) when is_atom(key),
-    do: block_keyword?(tail)
-
-  defp block_keyword?([]), do: true
-  defp block_keyword?(_), do: false
-
-  # Anything after the do block that is not a block keyword makes it a keyword list
-  defp kw_blocks?([{:do, _} | rest] = kw) do
-    Keyword.keyword?(kw) and Enum.all?(rest, &match?({key, _} when key in @do_end_keywords, &1))
-  end
-
-  defp kw_blocks?([{{:__block__, _, [:do]}, _} | rest]) do
-    Enum.all?(rest, &match?({{:__block__, _, [key]}, _} when key in @do_end_keywords, &1))
-  end
-
-  defp kw_blocks?(_), do: false
-
  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}, state, escape_interpolation) do
+  defp normalize_bitstring({:<<>>, meta, parts}, state, escape_interpolation \\ false) do
    meta = patch_meta_line(meta, state.parent_meta)

    parts =
@@ -435,21 +407,9 @@ defmodule Code.Normalizer do
        end)
      end

-    parts = maybe_add_trailing_newline(meta, parts, state)
    {:<<>>, meta, parts}
  end

-  defp maybe_add_trailing_newline(meta, parts, state) do
-    with true <- state.escape and Keyword.get(meta, :delimiter) in ["\"\"\"", "'''"],
-         last = List.last(parts),
-         true <- is_binary(last) and not String.ends_with?(last, "\n") do
-      [_last | rest] = Enum.reverse(parts)
-      Enum.reverse([last <> "\n" | rest])
-    else
-      _ -> parts
-    end
-  end
-
  defp normalize_interpolation_parts(parts, state, escape_interpolation) do
    Enum.map(parts, fn
      {:"::", interpolation_meta,
@@ -575,7 +535,7 @@ defmodule Code.Normalizer do
    atom
    |> Atom.to_string()
    |> maybe_escape_literal(state)
-    |> String.to_unsafe_atom()
+    |> String.to_atom()
  end

  defp maybe_escape_literal(term, _) do
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule Code.Typespec do
  @moduledoc false

@@ -31,6 +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)]}
+  end
+
  def spec_to_quoted(name, {:type, anno, :bounded_fun, [type, constrs]}) when is_atom(name) do
    meta = meta(anno)
    {:type, _, :fun, [{:type, _, :product, args}, result]} = type
@@ -80,8 +81,7 @@ defmodule Code.Typespec do
  Returns all types available from the module's BEAM code.

  The result is returned as a list of tuples where the first
-  element is the type (`:typep`, `:type`, `:opaque` and, on Erlang/OTP 28+,
-  `:nominal`).
+  element is the type (`:typep`, `:type` and `:opaque`).

  The module must have a corresponding BEAM file which can be
  located by the runtime system. The types will be in the Erlang
@@ -96,10 +96,9 @@ defmodule Code.Typespec do

        types =
          for {:attribute, _, kind, {name, _, args} = type} <- abstract_code,
-              kind in [:opaque, :type, :nominal] do
+              kind in [:opaque, :type] do
            cond do
              kind == :opaque -> {:opaque, type}
-              kind == :nominal -> {:nominal, type}
              {name, length(args)} in exported_types -> {:type, type}
              true -> {:typep, type}
            end
@@ -119,7 +118,7 @@ defmodule Code.Typespec do
  element is spec name and arity and the second is the spec.

  The module must have a corresponding BEAM file which can be
-  located by the runtime system. The specs will be in the Erlang
+  located by the runtime system. The types will be in the Erlang
  Abstract Format.
  """
  @spec fetch_specs(module | binary) :: {:ok, [tuple]} | :error
@@ -137,10 +136,10 @@ defmodule Code.Typespec do
  Returns all callbacks available from the module's BEAM code.

  The result is returned as a list of tuples where the first
-  element is the callback name and arity and the second is the callback.
+  element is spec name and arity and the second is the spec.

  The module must have a corresponding BEAM file
-  which can be located by the runtime system. The callbacks will be
+  which can be located by the runtime system. The types will be
  in the Erlang Abstract Format.
  """
  @spec fetch_callbacks(module | binary) :: {:ok, [tuple]} | :error
@@ -193,8 +192,8 @@ defmodule Code.Typespec do

  ## To AST conversion

-  defp collect_vars({:ann_type, _anno, [_var, type]}) do
-    collect_vars(type)
+  defp collect_vars({:ann_type, _anno, args}) when is_list(args) do
+    []
  end

  defp collect_vars({:type, _anno, _kind, args}) when is_list(args) do
@@ -289,6 +288,7 @@ defmodule Code.Typespec do
  end

  defp typespec_to_quoted({:type, anno, :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
@@ -317,6 +317,10 @@ defmodule Code.Typespec do
    [{:->, meta(anno), [[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, []}]})
+  end
+
  defp typespec_to_quoted({:type, anno, :range, [left, right]}) do
    {:.., meta(anno), [typespec_to_quoted(left), typespec_to_quoted(right)]}
  end
@@ -334,14 +338,10 @@ defmodule Code.Typespec do
    {erl_to_ex_var(var), meta(anno), nil}
  end

-  defp typespec_to_quoted({:op, anno, op, arg}) when op in [:+, :-] do
+  defp typespec_to_quoted({:op, anno, op, arg}) do
    {op, meta(anno), [typespec_to_quoted(arg)]}
  end

-  defp typespec_to_quoted({:op, anno, :*, arg1, arg2}) do
-    {:*, meta(anno), [typespec_to_quoted(arg1), typespec_to_quoted(arg2)]}
-  end
-
  defp typespec_to_quoted({:remote_type, anno, [mod, name, args]}) do
    remote_type(anno, mod, name, args)
  end
@@ -401,10 +401,10 @@ defmodule Code.Typespec do
  defp erl_to_ex_var(var) do
    case Atom.to_string(var) do
      <<"_", c::utf8, rest::binary>> ->
-        String.to_unsafe_atom("_#{String.downcase(<<c::utf8>>)}#{rest}")
+        String.to_atom("_#{String.downcase(<<c::utf8>>)}#{rest}")

      <<c::utf8, rest::binary>> ->
-        String.to_unsafe_atom("#{String.downcase(<<c::utf8>>)}#{rest}")
+        String.to_atom("#{String.downcase(<<c::utf8>>)}#{rest}")
    end
  end

@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defprotocol Collectable do
  @moduledoc """
  A protocol to traverse data structures.
@@ -69,22 +65,6 @@ defprotocol Collectable do
      iex> Enum.into([1, 2, 3], MapSet.new())
      MapSet.new([1, 2, 3])

-  ## Halting
-
-  The `:halt` flag will be given whenever the collection won't
-  terminate correctly and must be used to clean up existing resources
-  (such as sockets, file handles, etc).
-
-  Note it is not guaranteed that the accumulator given to halt will
-  be the latest version of the accumulator returned by a previous call
-  with `{:cont, elem}`. Therefore, you must track the collected results
-  within the resource you intend to halt.
-
-  This is by design: ensuring halt is always called with the latest
-  accumulator would make pure collectables (the ones that do not implement
-  halt) expensive. However, given the collectables that must implement halt
-  already need to track state, the burden of tracking the accumulator
-  across invocations is put on them.
  """

  @type command :: {:cont, term} | :done | :halt
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule Config do
  @moduledoc ~S"""
  A simple keyword-based configuration API.
@@ -45,8 +41,7 @@ defmodule Config do
  > 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, see ["Using application configuration for
-  > libraries"](design-anti-patterns.md#using-application-configuration-for-libraries).
+  > current project. For more information, read our [library guidelines](library-guidelines.md).

  ## Migrating from `use Mix.Config`

@@ -98,12 +93,6 @@ defmodule Config do
  (assembled with `mix release`).
  """

-  @type config_opts :: [
-          imports: [Path.t()] | :disabled,
-          env: atom(),
-          target: atom()
-        ]
-
  @opts_key {__MODULE__, :opts}
  @config_key {__MODULE__, :config}
  @imports_key {__MODULE__, :imports}
@@ -141,6 +130,7 @@ defmodule Config do

      config :logger,
        level: :warn,
+        backends: [:console]

      config :logger,
        level: :info,
@@ -148,13 +138,12 @@ defmodule Config do

  will have a final configuration for `:logger` of:

-      [level: :info, truncate: 1024]
+      [level: :info, backends: [:console], truncate: 1024]

  """
  @doc since: "1.9.0"
-  @spec config(atom(), keyword()) :: keyword()
  def config(root_key, opts) when is_atom(root_key) and is_list(opts) do
-    if not Keyword.keyword?(opts) do
+    unless Keyword.keyword?(opts) do
      raise ArgumentError, "config/2 expected a keyword list, got: #{inspect(opts)}"
    end

@@ -199,45 +188,17 @@ defmodule Config do

  """
  @doc since: "1.9.0"
-  @spec config(atom(), atom(), term()) :: keyword()
  def config(root_key, key, opts) when is_atom(root_key) and is_atom(key) do
    get_config!()
    |> __merge__([{root_key, [{key, opts}]}])
    |> put_config()
  end

-  @doc """
-  Reads the configuration for the given root key.
-
-  This function only reads the configuration from a previous
-  `config/2` or `config/3` call. If `root_key` points to an
-  application, it does not read its actual application environment.
-  Its main use case is to make it easier to access and share
-  configuration values across files.
-
-  If the `root_key` was not configured, it returns `nil`.
-
-  ## Examples
-
-      # In config/config.exs
-      config :my_app, foo: :bar
-
-      # In config/dev.exs
-      config :another_app, foo: read_config(:my_app)[:foo] || raise "missing parent configuration"
-
-  """
-  @doc since: "1.18.0"
-  @spec read_config(atom()) :: keyword() | nil
-  def read_config(root_key) when is_atom(root_key) do
-    get_config!()[root_key]
-  end
-
  @doc """
  Returns the environment this configuration file is executed on.

  In Mix projects this function returns the environment this configuration
-  file is executed on.
-  In releases, returns the `MIX_ENV` specified when running `mix release`.
+  file is executed on. In releases, the environment when `mix release` ran.

  This is most often used to execute conditional code:

@@ -287,8 +248,8 @@ defmodule Config do

  In case the file doesn't exist, an error is raised.

-  If the file is relative, it will be expanded relative to the
-  directory of the current configuration file.
+  If file is a relative, it will be expanded relatively to the
+  directory the current configuration file is in.

  ## Examples

@@ -315,7 +276,7 @@ defmodule Config do
  end

  @doc false
-  @spec __eval__!(Path.t(), binary(), config_opts) :: {keyword, [Path.t()] | :disabled}
+  @spec __eval__!(Path.t(), binary(), keyword) :: {keyword, [Path.t()] | :disabled}
  def __eval__!(file, content, opts \\ []) when is_binary(file) and is_list(opts) do
    env = Keyword.get(opts, :env)
    target = Keyword.get(opts, :target)
@@ -380,27 +341,21 @@ defmodule Config do
    end
  end

-  defp validate!(config, file) when is_list(config) do
-    Enum.each(config, fn
+  defp validate!(config, file) do
+    Enum.all?(config, fn
      {app, value} when is_atom(app) ->
-        if not Keyword.keyword?(value) do
+        if Keyword.keyword?(value) do
+          true
+        else
          raise ArgumentError,
                "expected config for app #{inspect(app)} in #{Path.relative_to_cwd(file)} " <>
                  "to return keyword list, got: #{inspect(value)}"
        end

-      other ->
-        raise ArgumentError,
-              "expected config in #{Path.relative_to_cwd(file)} to be a keyword list " <>
-                "of {atom, keyword} pairs, got entry: #{inspect(other)}"
+      _ ->
+        false
    end)

    config
  end
-
-  defp validate!(config, file) do
-    raise ArgumentError,
-          "expected config in #{Path.relative_to_cwd(file)} to be a keyword list " <>
-            "of {atom, keyword} pairs, got: #{inspect(config)}"
-  end
 end
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule Config.Provider do
  @moduledoc """
  Specifies a provider API that loads configuration during boot.
@@ -25,7 +21,7 @@ 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`:
+  this inside the `def project` portion of  your `mix.exs`:

      releases: [
        demo: [
@@ -111,16 +107,6 @@ defmodule Config.Provider do
  """
  @type config_path :: {:system, binary(), binary()} | binary()

-  @typedoc """
-  Options for `init/3`.
-  """
-  @type init_opts :: [
-          extra_config: config(),
-          prune_runtime_sys_config_after_boot: boolean(),
-          reboot_system_after_config: boolean(),
-          validate_compile_env: [{atom(), [atom()], term()}]
-        ]
-
  @doc """
  Invoked when initializing a config provider.

@@ -206,7 +192,6 @@ defmodule Config.Provider do
  @reboot_mode_key :config_provider_reboot_mode

  @doc false
-  @spec init([{module(), term()}], config_path(), init_opts()) :: config()
  def init(providers, config_path, opts \\ []) when is_list(providers) and is_list(opts) do
    validate_config_path!(config_path)
    providers = for {provider, init} <- providers, do: {provider, provider.init(init)}
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule Config.Reader do
  @moduledoc """
  API for reading config files defined with `Config`.
@@ -16,7 +12,7 @@ defmodule Config.Reader do

  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`:
+  of  your `mix.exs`:

      releases: [
        demo: [
@@ -46,12 +42,6 @@ defmodule Config.Reader do

  @behaviour Config.Provider

-  @type config_opts :: [
-          imports: [Path.t()] | :disabled,
-          env: atom(),
-          target: atom()
-        ]
-
  @impl true
  def init(opts) when is_list(opts) do
    {path, opts} = Keyword.pop!(opts, :path)
@@ -74,7 +64,7 @@ defmodule Config.Reader do
  Accepts the same options as `read!/2`.
  """
  @doc since: "1.11.0"
-  @spec eval!(Path.t(), binary, config_opts) :: keyword
+  @spec eval!(Path.t(), binary, keyword) :: keyword
  def eval!(file, contents, opts \\ [])
      when is_binary(file) and is_binary(contents) and is_list(opts) do
    Config.__eval__!(Path.expand(file), contents, opts) |> elem(0)
@@ -96,7 +86,7 @@ defmodule Config.Reader do

  """
  @doc since: "1.9.0"
-  @spec read!(Path.t(), config_opts) :: keyword
+  @spec read!(Path.t(), keyword) :: keyword
  def read!(file, opts \\ []) when is_binary(file) and is_list(opts) do
    file = Path.expand(file)
    Config.__eval__!(file, File.read!(file), opts) |> elem(0)
@@ -110,7 +100,7 @@ defmodule Config.Reader do
  option cannot be disabled in `read_imports!/2`.
  """
  @doc since: "1.9.0"
-  @spec read_imports!(Path.t(), config_opts) :: {keyword, [Path.t()]}
+  @spec read_imports!(Path.t(), keyword) :: {keyword, [Path.t()]}
  def read_imports!(file, opts \\ []) when is_binary(file) and is_list(opts) do
    if opts[:imports] == :disabled do
      raise ArgumentError, ":imports must be a list of paths"
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule Dict do
  @moduledoc ~S"""
  Generic API for dictionaries.
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule DynamicSupervisor do
  @moduledoc ~S"""
  A supervisor optimized to only start children dynamically.
@@ -16,7 +12,7 @@ defmodule DynamicSupervisor do

  ## Examples

-  A dynamic supervisor is started with no children and often with a name:
+  A dynamic supervisor is started with no children and often a name:

      children = [
        {DynamicSupervisor, name: MyApp.DynamicSupervisor, strategy: :one_for_one}
@@ -137,6 +133,67 @@ defmodule DynamicSupervisor do

  A supervisor is bound to the same name registration rules as a `GenServer`.
  Read more about these rules in the documentation for `GenServer`.
+
+  ## Migrating from Supervisor's :simple_one_for_one
+
+  In case you were using the deprecated `:simple_one_for_one` strategy from
+  the `Supervisor` module, you can migrate to the `DynamicSupervisor` in
+  few steps.
+
+  Imagine the given "old" code:
+
+      defmodule MySupervisor do
+        use Supervisor
+
+        def start_link(init_arg) do
+          Supervisor.start_link(__MODULE__, init_arg, name: __MODULE__)
+        end
+
+        def start_child(foo, bar, baz) do
+          # This will start child by calling MyWorker.start_link(init_arg, foo, bar, baz)
+          Supervisor.start_child(__MODULE__, [foo, bar, baz])
+        end
+
+        @impl true
+        def init(init_arg) do
+          children = [
+            # Or the deprecated: worker(MyWorker, [init_arg])
+            %{id: MyWorker, start: {MyWorker, :start_link, [init_arg]}}
+          ]
+
+          Supervisor.init(children, strategy: :simple_one_for_one)
+        end
+      end
+
+  It can be upgraded to the DynamicSupervisor like this:
+
+      defmodule MySupervisor do
+        use DynamicSupervisor
+
+        def start_link(init_arg) do
+          DynamicSupervisor.start_link(__MODULE__, init_arg, name: __MODULE__)
+        end
+
+        def start_child(foo, bar, baz) do
+          # If MyWorker is not using the new child specs, we need to pass a map:
+          # spec = %{id: MyWorker, start: {MyWorker, :start_link, [foo, bar, baz]}}
+          spec = {MyWorker, foo: foo, bar: bar, baz: baz}
+          DynamicSupervisor.start_child(__MODULE__, spec)
+        end
+
+        @impl true
+        def init(init_arg) do
+          DynamicSupervisor.init(
+            strategy: :one_for_one,
+            extra_arguments: [init_arg]
+          )
+        end
+      end
+
+  The difference is that the `DynamicSupervisor` expects the child specification
+  at the moment `start_child/2` is called, and no longer on the init callback.
+  If there are any initial arguments given on initialization, such as `[initial_arg]`,
+  it can be given in the `:extra_arguments` flag on `DynamicSupervisor.init/1`.
  """

  @behaviour GenServer
@@ -158,7 +215,10 @@ defmodule DynamicSupervisor do
          extra_arguments: [term()]
        }

-  @typedoc "Options given to `start_link/1` and `init/1` functions"
+  @typedoc "Options given to `start_link` functions"
+  @type option :: GenServer.option()
+
+  @typedoc "Options given to `start_link` and `init/1` functions"
  @type init_option ::
          {:strategy, strategy()}
          | {:max_restarts, non_neg_integer()}
@@ -169,15 +229,7 @@ defmodule DynamicSupervisor do
  @typedoc "Supported strategies"
  @type strategy :: :one_for_one

-  @typedoc """
-  Return values of `start_child` functions.
-
-  Unlike `Supervisor`, this module ignores the child spec ids,
-  so `{:error, {:already_started, pid}}` is not returned for child specs
-  given with the same id. `{:error, {:already_started, pid}}` is returned
-  however if a duplicate name is used when using
-  [name registration](`m:GenServer#module-name-registration`).
-  """
+  @typedoc "Return values of `start_child` functions"
  @type on_start_child ::
          {:ok, pid}
          | {:ok, pid, info :: term}
@@ -206,7 +258,6 @@ defmodule DynamicSupervisor do
  See `Supervisor` for more information about child specifications.
  """
  @doc since: "1.6.1"
-  @spec child_spec([init_option() | GenServer.option()]) :: Supervisor.child_spec()
  def child_spec(options) when is_list(options) do
    id =
      case Keyword.get(options, :name, DynamicSupervisor) do
@@ -226,7 +277,7 @@ defmodule DynamicSupervisor do
  defmacro __using__(opts) do
    quote location: :keep, bind_quoted: [opts: opts] do
      @behaviour DynamicSupervisor
-      if not Module.has_attribute?(__MODULE__, :doc) do
+      unless Module.has_attribute?(__MODULE__, :doc) do
        @doc """
        Returns a specification to start this module under a supervisor.

@@ -294,11 +345,9 @@ defmodule DynamicSupervisor do
      specified in the child spec given to `start_child/2`. Defaults to
      an empty list.

-    * Any of the standard [GenServer options](`t:GenServer.option/0`)
-
  """
  @doc since: "1.6.0"
-  @spec start_link([init_option | GenServer.option()]) :: Supervisor.on_start()
+  @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)
@@ -332,15 +381,9 @@ defmodule DynamicSupervisor do
  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
-
-  This function accepts any regular [`GenServer` options](`t:GenServer.option/0`).
-  Options specific to `DynamicSupervisor` must be returned from the `c:init/1`
-  callback.
  """
  @doc since: "1.6.0"
-  @spec start_link(module, term, [GenServer.option()]) :: Supervisor.on_start()
+  @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)
  end
@@ -348,17 +391,11 @@ defmodule DynamicSupervisor do
  @doc """
  Dynamically adds a child specification to `supervisor` and starts that child.

-  `child_spec` should be a valid [child specification](`m:Supervisor#module-child-specification`).
-  The child process will be started as defined in the child specification. Note that while
+  `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. Unlike `Supervisor`, this module does not
-  return `{:error, {:already_started, pid}}` for child specs given with the same id.
-  `{:error, {:already_started, pid}}` is returned however if a duplicate name is
-  used when using [name registration](`m:GenServer#module-name-registration`).
-
-  This function will block the `DynamicSupervisor` until the child initializes.
-  When starting too many processes dynamically, you may want to use a
-  `PartitionSupervisor` to split the work across multiple processes.
+  therefore does not need to be unique.

  If the child process start function returns `{:ok, child}` or `{:ok, child,
  info}`, then child specification and PID are added to the supervisor and
@@ -463,14 +500,6 @@ defmodule DynamicSupervisor do
  @doc """
  Terminates the given child identified by `pid`.

-  This function will block the `DynamicSupervisor` until the child
-  terminates, which may take an arbitrary amount of time if the child
-  is trapping exits and implements its own terminate callback.
-  For this reason, it is often better to ask the child process
-  itself to terminate, often by declaring in its child spec it has
-  a restart strategy of `:transient` (or `:temporary`) and then
-  sending it a message to stop with reason `:shutdown`.
-
  If successful, this function returns `:ok`. If there is no process with
  the given PID, this function returns `{:error, :not_found}`.
  """
@@ -481,11 +510,11 @@ defmodule DynamicSupervisor do
  end

  @doc """
-  Returns a list with information about all children of the given supervisor.
+  Returns a list with information about all children.

  Note that calling this function when supervising a large number
-  of children under low memory conditions can bring the system down due to an
-  out of memory error.
+  of children under low memory conditions can cause an out of memory
+  exception.

  This function returns a list of tuples containing:

@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 require Record

 defmodule File.Stat do
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule File.Stream do
  @moduledoc """
  Defines a `File.Stream` struct returned by `File.stream!/3`.
@@ -18,13 +14,7 @@ defmodule File.Stream do

  defstruct path: nil, modes: [], line_or_bytes: :line, raw: true, node: nil

-  @type t :: %__MODULE__{
-          path: Path.t(),
-          modes: [term()],
-          line_or_bytes: :line | pos_integer(),
-          raw: boolean(),
-          node: node()
-        }
+  @type t :: %__MODULE__{}

  @doc false
  def __build__(path, line_or_bytes, modes) do
@@ -125,7 +115,7 @@ defmodule File.Stream do

      counter = fn device ->
        device = skip_bom_and_offset(device, raw, modes)
-        count_lines(device, path, pattern, read_function(stream), 0, :empty)
+        count_lines(device, path, pattern, read_function(stream), 0)
      end

      {:ok, open!(stream, modes, counter)}
@@ -235,28 +225,21 @@ defmodule File.Stream do
      for mode <- modes, mode not in [:write, :append, :trim_bom], do: mode
    end

-    defp count_lines(device, path, pattern, read, count, last_byte) do
+    defp count_lines(device, path, pattern, read, count) do
      case read.(device) do
-        data when is_binary(data) and byte_size(data) > 0 ->
-          newlines = length(:binary.matches(data, pattern))
-          last = :binary.last(data)
-          count_lines(device, path, pattern, read, count + newlines, last)
-
        data when is_binary(data) ->
-          count_lines(device, path, pattern, read, count, last_byte)
+          count_lines(device, path, pattern, read, count + count_lines(data, pattern))

        :eof ->
-          case last_byte do
-            :empty -> 0
-            ?\n -> count
-            _ -> count + 1
-          end
+          count

        {:error, reason} ->
          raise File.Error, reason: reason, action: "stream", path: path
      end
    end

+    defp count_lines(data, pattern), do: length(:binary.matches(data, pattern))
+
    defp read_function(%{raw: true}), do: &IO.binread(&1, @read_ahead_size)
    defp read_function(%{raw: false}), do: &IO.read(&1, @read_ahead_size)
  end
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 import Kernel, except: [round: 1]

 defmodule Float do
@@ -25,7 +21,7 @@ defmodule Float do
  and arithmetic 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.
+  to Elixir, they are a property of floating point representation itself.

  For example, the numbers 0.1 and 0.01 are two of them, what means the result
  of squaring 0.1 does not give 0.01 neither the closest representable. Here is
@@ -42,7 +38,7 @@ defmodule Float do

  To learn more about floating-point arithmetic visit:

-    * [0.30000000000000004.com](https://0.30000000000000004.com/)
+    * [0.30000000000000004.com](http://0.30000000000000004.com/)
    * [What Every Programmer Should Know About Floating-Point Arithmetic](https://floating-point-gui.de/)

  """
@@ -143,8 +139,6 @@ defmodule Float do
      iex> Float.parse("56.5xyz")
      {56.5, "xyz"}

-      iex> Float.parse(".12")
-      :error
      iex> Float.parse("pi")
      :error
      iex> Float.parse("1.7976931348623159e+308")
@@ -167,73 +161,41 @@ defmodule Float do
    parse_unsigned(binary)
  end

-  defp parse_unsigned(<<digit, rest::binary>> = binary) when digit in ?0..?9,
-    do: parse_mantissa(binary, rest, false)
+  defp parse_unsigned(<<digit, rest::binary>>) when digit in ?0..?9,
+    do: parse_unsigned(rest, false, false, <<digit>>)

  defp parse_unsigned(binary) when is_binary(binary), do: :error

-  defp parse_mantissa(binary, <<digit, rest::binary>>, dot?) when digit in ?0..?9,
-    do: parse_mantissa(binary, rest, dot?)
+  defp parse_unsigned(<<digit, rest::binary>>, dot?, e?, acc) when digit in ?0..?9,
+    do: parse_unsigned(rest, dot?, e?, <<acc::binary, digit>>)

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

-  defp parse_mantissa(binary, <<exp_marker, digit, rest::binary>> = tail, dot?)
+  defp parse_unsigned(<<exp_marker, digit, rest::binary>>, dot?, false, acc)
       when exp_marker in ~c"eE" and digit in ?0..?9,
-       do: parse_exponent(binary, byte_size(binary) - byte_size(tail), rest, dot?)
+       do: parse_unsigned(rest, true, true, <<add_dot(acc, dot?)::binary, ?e, digit>>)

-  defp parse_mantissa(binary, <<exp_marker, sign, digit, rest::binary>> = tail, dot?)
+  defp parse_unsigned(<<exp_marker, sign, digit, rest::binary>>, dot?, false, acc)
       when exp_marker in ~c"eE" and sign in ~c"-+" and digit in ?0..?9,
-       do: parse_exponent(binary, byte_size(binary) - byte_size(tail), rest, dot?)
+       do: parse_unsigned(rest, true, true, <<add_dot(acc, dot?)::binary, ?e, sign, digit>>)

-  defp parse_mantissa(binary, rest, dot?), do: finish_mantissa(binary, rest, dot?)
-
-  defp parse_exponent(binary, exp_pos, <<digit, rest::binary>>, dot?) when digit in ?0..?9,
-    do: parse_exponent(binary, exp_pos, rest, dot?)
-
-  defp parse_exponent(binary, exp_pos, rest, dot?),
-    do: finish_exponent(binary, exp_pos, rest, dot?)
-
-  defp finish_mantissa(binary, rest, _dot? = true) do
-    {:erlang.binary_to_float(consumed(binary, rest)), rest}
+  # 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

-  # Bare integer: * 1.0 casts to the nearest float without building a new binary,
-  # and raises ArithmeticError on overflow (for example a 400-digit integer).
-  defp finish_mantissa(binary, rest, _dot? = false) do
-    {:erlang.binary_to_integer(consumed(binary, rest)) * 1.0, rest}
-  rescue
-    ArithmeticError -> :error
-  end
+  defp parse_unsigned(rest, dot?, false = _e?, acc),
+    do: {:erlang.binary_to_float(add_dot(acc, dot?)), rest}

-  # binary_to_float/1 raises ArgumentError when the exponent is too big, e.g. "1.0e400".
-  defp finish_exponent(binary, _exp_pos, rest, _dot? = true) do
-    {:erlang.binary_to_float(consumed(binary, rest)), rest}
-  rescue
-    ArgumentError -> :error
-  end
-
-  # No decimal point, so ".0" is spliced in before the exponent (at exp_pos) to
-  # form a valid float literal.
-  defp finish_exponent(binary, exp_pos, rest, _dot? = false) do
-    len = byte_size(binary) - byte_size(rest)
-
-    literal =
-      IO.iodata_to_binary([
-        :binary.part(binary, 0, exp_pos),
-        ".0",
-        :binary.part(binary, exp_pos, len - exp_pos)
-      ])
-
-    {:erlang.binary_to_float(literal), rest}
-  rescue
-    ArgumentError -> :error
-  end
-
-  defp consumed(binary, ""), do: binary
-  defp consumed(binary, rest), do: :binary.part(binary, 0, byte_size(binary) - byte_size(rest))
+  defp add_dot(acc, true), do: acc
+  defp add_dot(acc, false), do: acc <> ".0"

  @doc """
  Rounds a float to the largest float less than or equal to `number`.
@@ -286,7 +248,7 @@ defmodule Float do
  @doc """
  Rounds a float to the smallest float greater than or equal to `number`.

-  `ceil/2` also accepts a precision to round a floating-point value up
+  `ceil/2` also accepts a precision to round a floating-point value down
  to an arbitrary number of fractional digits (between 0 and 15).

  The operation is performed on the binary floating point, without a
@@ -355,7 +317,7 @@ defmodule Float do
  and therefore the number above is internally represented as 5.567499999,
  which explains the behavior above. If you want exact rounding for decimals,
  you must use a decimal library. The behavior above is also in accordance
-  with reference implementations, such as "Correctly Rounded Binary-Decimal and
+  to reference implementations, such as "Correctly Rounded Binary-Decimal and
  Decimal-Binary Conversions" by David M. Gay.

  ## Examples
@@ -377,12 +339,15 @@ defmodule Float do

  """
  @spec round(float, precision_range) :: float
+  # This implementation is slow since it relies on big integers.
+  # Faster implementations are available on more recent papers
+  # and could be implemented in the future.
  def round(float, precision \\ 0)

-  def round(float, 0) when float === 0.0 or float === -0.0, do: float
+  def round(float, 0) when float == 0.0, do: float

  def round(float, 0) when is_float(float) do
-    case :erlang.round(float) * 1.0 do
+    case float |> :erlang.round() |> :erlang.float() do
      zero when zero == 0.0 and float < 0.0 -> -0.0
      rounded -> rounded
    end
@@ -396,170 +361,140 @@ defmodule Float do
    raise ArgumentError, invalid_precision_message(precision)
  end

-  # Decimal-place rounding via exact rational scaling. This is the bignum
-  # core used by reference implementations like David M. Gay's "Correctly
-  # Rounded Binary-Decimal and Decimal-Binary Conversions" (cited in the
-  # @doc above), Python's round(), and Java's BigDecimal.setScale.
-  #
-  # 1. Decompose float exactly: |float| = mantissa / 2^shift.
-  # 2. Scale exactly: |float| * 10^precision = mantissa * 10^precision / 2^shift.
-  #    Because precision is bounded to 0..15, the product fits in ~103 bits
-  #    (53-bit mantissa + ~50-bit power of ten) and BEAM bignums handle it
-  #    directly without approximation.
-  # 3. Round the exact rational to an integer per the requested mode
-  #    (half_up / floor / ceil) using quotient and remainder.
-  # 4. Emit the float closest to rounded_int / 10^precision:
-  #    - fast path: when rounded_int < 2^53, both operands are exactly
-  #      representable as floats and IEEE division is correctly rounded.
-  #    - slow path: bignum alignment + manual mantissa extraction with
-  #      round-to-nearest-even for the trailing bit.
-  #
-  # The integer-rounding decision (step 3) and the binary-emission decision
-  # (step 4) are deliberately independent: step 3 picks the exact rational
-  # the user asked for, step 4 picks the closest float to that rational.
-  # Conflating them is the classic source of double-rounding bugs.
-  #
-  # Faster algorithms exist (Cox 2026's table-based uscale; Ryū / Schubfach
-  # for round-trip printing) but target different problems or assume
-  # fixed-width machine arithmetic that BEAM doesn't expose efficiently.
-  # At precision <= 15, the exact path is small, easy to audit, and fast
-  # enough that a more complex algorithm has not been justified by benchmarks.
  defp round(num, _precision, _rounding) when is_float(num) and num == 0.0, do: num

-  defp round(float, precision, mode) do
-    <<sign::1, exp::11, mantissa::52>> = <<float::float>>
+  defp round(float, precision, rounding) do
+    <<sign::1, exp::11, significant::52-bitstring>> = <<float::float>>
+    {num, count} = decompose(significant, 1)
+    count = count - exp + 1023

    cond do
-      # Subnormal — tiny but non-zero; treat per-mode (ceil(+) and floor(-) bump
-      # to 10^-precision; everything else rounds to signed zero).
-      exp == 0 ->
-        tiny_round(sign, precision, mode)
+      # Precision beyond 15 digits
+      count >= 104 ->
+        case rounding do
+          :ceil when sign === 0 -> 1 / power_of_10(precision)
+          :floor when sign === 1 -> -1 / power_of_10(precision)
+          :ceil when sign === 1 -> minus_zero()
+          :half_up when sign === 1 -> minus_zero()
+          _ -> 0.0
+        end

-      # |float| >= 2^52 — has no fractional bits, return unchanged.
-      exp - 1075 >= 0 ->
+      # We are asking more precision than we have
+      count <= precision ->
        float

      true ->
-        mantissa = @power_of_2_to_52 ||| mantissa
-        shift = 1075 - exp
-        do_round(sign, mantissa, shift, precision, mode)
+        # Difference in precision between float and asked precision
+        # We subtract 1 because we need to calculate the remainder too
+        diff = count - precision - 1
+
+        # Get up to latest so we calculate the remainder
+        power_of_10 = power_of_10(diff)
+
+        # Convert the numerand to decimal base
+        num = num * power_of_5(count)
+
+        # Move to the given precision - 1
+        num = div(num, power_of_10)
+        div = div(num, 10)
+        num = rounding(rounding, sign, num, div)
+
+        # Convert back to float without loss
+        # https://www.exploringbinary.com/correct-decimal-to-floating-point-using-big-integers/
+        den = power_of_10(precision)
+        boundary = den <<< 52
+
+        cond do
+          num == 0 and sign == 1 ->
+            minus_zero()
+
+          num == 0 ->
+            0.0
+
+          num >= boundary ->
+            {den, exp} = scale_down(num, boundary, 52)
+            decimal_to_float(sign, num, den, exp)
+
+          true ->
+            {num, exp} = scale_up(num, boundary, 52)
+            decimal_to_float(sign, num, den, exp)
+        end
    end
  end

-  # |float * 10^precision| < 0.5 — integer round is 0; ceil/floor still bump per sign.
-  defp do_round(sign, _mantissa, shift, precision, mode) when shift >= 104 do
-    tiny_round(sign, precision, mode)
+  # TODO remove once we require Erlang/OTP 27+
+  # This function tricks the compiler to avoid this bug in previous versions:
+  # https://github.com/elixir-lang/elixir/blob/main/lib/elixir/lib/float.ex#L408-L412
+  defp minus_zero, do: -0.0
+
+  defp decompose(significant, initial) do
+    decompose(significant, 1, 0, initial)
  end

-  defp do_round(sign, mantissa, shift, precision, mode) do
-    power = power_of_10(precision)
-    product = mantissa * power
-    half = 1 <<< (shift - 1)
-    quotient = product >>> shift
-    remainder = product - (quotient <<< shift)
-    rounded_int = round_step(mode, sign, quotient, remainder, half)
+  defp decompose(<<1::1, bits::bitstring>>, count, last_count, acc) do
+    decompose(bits, count + 1, count, (acc <<< (count - last_count)) + 1)
+  end

-    cond do
-      rounded_int == 0 ->
-        signed_zero(sign)
+  defp decompose(<<0::1, bits::bitstring>>, count, last_count, acc) do
+    decompose(bits, count + 1, last_count, acc)
+  end

-      rounded_int < @power_of_2_to_52 <<< 1 ->
-        # Both rounded_int and power fit in 53 bits, so IEEE float division
-        # is correctly rounded.
-        result = rounded_int / power
-        if sign == 1, do: -result, else: result
+  defp decompose(<<>>, _count, last_count, acc) do
+    {acc, last_count}
+  end

-      true ->
-        bignum_to_float(sign, rounded_int, power)
+  defp scale_up(num, boundary, exp) when num >= boundary, do: {num, exp}
+  defp scale_up(num, boundary, exp), do: scale_up(num <<< 1, boundary, exp - 1)
+
+  defp scale_down(num, den, exp) do
+    new_den = den <<< 1
+
+    if num < new_den do
+      {den >>> 52, exp}
+    else
+      scale_down(num, new_den, exp + 1)
    end
  end

-  defp round_step(:half_up, _sign, quotient, remainder, half) do
-    if remainder >= half, do: quotient + 1, else: quotient
-  end
+  defp decimal_to_float(sign, num, den, exp) do
+    quo = div(num, den)
+    rem = num - quo * den

-  defp round_step(:floor, 0, quotient, _remainder, _half), do: quotient
-  defp round_step(:floor, 1, quotient, remainder, _half) when remainder > 0, do: quotient + 1
-  defp round_step(:floor, 1, quotient, _remainder, _half), do: quotient
-
-  defp round_step(:ceil, 0, quotient, remainder, _half) when remainder > 0, do: quotient + 1
-  defp round_step(:ceil, 0, quotient, _remainder, _half), do: quotient
-  defp round_step(:ceil, 1, quotient, _remainder, _half), do: quotient
-
-  defp signed_zero(0), do: 0.0
-  defp signed_zero(1), do: -0.0
-
-  # Result of rounding a non-zero float whose |float * 10^precision| < 0.5.
-  # ceil(+) → +10^-precision, floor(-) → -10^-precision, others → signed 0.
-  defp tiny_round(0, precision, :ceil), do: 1.0 / power_of_10(precision)
-  defp tiny_round(1, precision, :floor), do: -1.0 / power_of_10(precision)
-  defp tiny_round(sign, _precision, _mode), do: signed_zero(sign)
-
-  # Slow path: emit float closest to `sign * rounded_int / power` when
-  # rounded_int >= 2^53. The binary emission step is always IEEE
-  # round-to-nearest-even, regardless of the integer-rounding mode.
-  defp bignum_to_float(sign, rounded_int, power) do
-    shift_adjust = bit_length(rounded_int) - bit_length(power) - 53
-    {numerator, denominator, exp} = align(rounded_int, power, shift_adjust)
-
-    quotient = div(numerator, denominator)
-    remainder = numerator - quotient * denominator
-    half = denominator >>> 1
-
-    mantissa =
-      cond do
-        remainder > half -> quotient + 1
-        remainder < half -> quotient
-        (quotient &&& 1) === 1 -> quotient + 1
-        true -> quotient
+    tmp =
+      case den >>> 1 do
+        den when rem > den -> quo + 1
+        den when rem < den -> quo
+        _ when (quo &&& 1) === 1 -> quo + 1
+        _ -> quo
      end

-    # Carry-bit normalization: `mantissa` lives in [2^52, 2^53]. The upper
-    # bound `2^53` is reachable when `align/3` returns an upper-bound quotient
-    # or when rounding carries. Rebalance into the canonical [2^52, 2^53)
-    # range so the 52-bit packing below doesn't silently truncate.
-    {mantissa, exp} =
-      if mantissa == @power_of_2_to_52 <<< 1,
-        do: {@power_of_2_to_52, exp + 1},
-        else: {mantissa, exp}
-
-    <<result::float>> = <<sign::1, exp + 1023::11, mantissa - @power_of_2_to_52::52>>
-    result
+    tmp = tmp - @power_of_2_to_52
+    <<tmp::float>> = <<sign::1, exp + 1023::11, tmp::52>>
+    tmp
  end

-  # Pick (numerator, denominator, exp) so that numerator/denominator ∈ [2^52, 2^53)
-  # and the resulting float = numerator/denominator * 2^(exp-52).
-  defp align(rounded_int, power, shift_adjust) when shift_adjust >= 0 do
-    new_power = power <<< shift_adjust
+  defp rounding(:floor, 1, _num, div), do: div + 1
+  defp rounding(:ceil, 0, _num, div), do: div + 1

-    if rounded_int < new_power <<< 53,
-      do: {rounded_int, new_power, 52 + shift_adjust},
-      else: {rounded_int, new_power <<< 1, 53 + shift_adjust}
-  end
-
-  defp align(rounded_int, power, shift_adjust) do
-    shifted = rounded_int <<< -shift_adjust
-
-    cond do
-      shifted >= power <<< 53 -> {shifted, power <<< 1, 53 + shift_adjust}
-      shifted >= power <<< 52 -> {shifted, power, 52 + shift_adjust}
-      true -> {shifted <<< 1, power, 51 + shift_adjust}
+  defp rounding(:half_up, _sign, num, div) do
+    case rem(num, 10) do
+      rem when rem < 5 -> div
+      rem when rem >= 5 -> div + 1
    end
  end

-  defp bit_length(0), do: 0
-  defp bit_length(integer) when integer > 0, do: bit_length(integer, 0)
-  defp bit_length(integer, acc) when integer >= 1 <<< 64, do: bit_length(integer >>> 64, acc + 64)
-  defp bit_length(integer, acc) when integer >= 1 <<< 16, do: bit_length(integer >>> 16, acc + 16)
-  defp bit_length(integer, acc) when integer >= 1 <<< 4, do: bit_length(integer >>> 4, acc + 4)
-  defp bit_length(integer, acc) when integer >= 1, do: bit_length(integer >>> 1, acc + 1)
-  defp bit_length(_integer, acc), do: acc
+  defp rounding(_, _, _, div), do: div

-  Enum.reduce(0..15, 1, fn exponent, acc ->
-    defp power_of_10(unquote(exponent)), do: unquote(acc)
+  Enum.reduce(0..104, 1, fn x, acc ->
+    defp power_of_10(unquote(x)), do: unquote(acc)
    acc * 10
  end)

+  Enum.reduce(0..104, 1, fn x, acc ->
+    defp power_of_5(unquote(x)), do: unquote(acc)
+    acc * 5
+  end)
+
  @doc """
  Returns a pair of integers whose ratio is exactly equal
  to the original float and with a positive denominator.
@@ -640,14 +575,18 @@ defmodule Float do
  Returns a charlist which corresponds to the shortest text representation
  of the given float.

-  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.
+  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`.

-  Inlined by the compiler.
-
  ## Examples

      iex> Float.to_charlist(7.0)
@@ -655,7 +594,7 @@ defmodule Float do

  """
  @spec to_charlist(float) :: charlist
-  def to_charlist(float) do
+  def to_charlist(float) when is_float(float) do
    :erlang.float_to_list(float, [:short])
  end

@@ -675,8 +614,6 @@ defmodule Float do

  For a configurable representation, use `:erlang.float_to_binary/2`.

-  Inlined by the compiler.
-
  ## Examples

      iex> Float.to_string(7.0)
@@ -684,7 +621,7 @@ defmodule Float do

  """
  @spec to_string(float) :: String.t()
-  def to_string(float) do
+  def to_string(float) when is_float(float) do
    :erlang.float_to_binary(float, [:short])
  end

@@ -705,7 +642,7 @@ defmodule Float do
  end

  defp invalid_precision_message(precision) do
-    "precision #{inspect(precision)} is out of valid range of #{inspect(@precision_range)}"
+    "precision #{precision} is out of valid range of #{inspect(@precision_range)}"
  end

  defp expand_compact([{:compact, false} | t]), do: expand_compact(t)
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule Function do
  @moduledoc """
  A set of functions for working with functions.
@@ -69,6 +65,7 @@ defmodule Function do
          | :name
          | :new_index
          | :new_uniq
+          | :pid
          | :type
          | :uniq

@@ -111,6 +108,8 @@ defmodule Function do
  When `fun` is an anonymous function (that is, the type is `:local`), the following
  additional keys are returned:

+    * `:pid` - PID of the process that originally created the function.
+
    * `:index` - (integer) an index into the module function table.

    * `:new_index` - (integer) an index into the module function table.
@@ -156,7 +155,7 @@ defmodule Function do
  `:module`, `:name`, `:arity`, `:env`, or `:type`.

  For anonymous functions, there is also information about any of the
-  atoms `:index`, `:new_index`, `:new_uniq`, and `:uniq`.
+  atoms `:index`, `:new_index`, `:new_uniq`, `:uniq`, and `:pid`.
  For a named function, the value of any of these items is always the
  atom `:undefined`.

@@ -176,6 +175,8 @@ defmodule Function do
      iex> fun = &String.length/1
      iex> Function.info(fun, :name)
      {:name, :length}
+      iex> Function.info(fun, :pid)
+      {:pid, :undefined}

  """
  @doc since: "1.7.0"
@@ -1,7 +1,3 @@
-# SPDX-License-Identifier: Apache-2.0
-# SPDX-FileCopyrightText: 2021 The Elixir Team
-# SPDX-FileCopyrightText: 2012 Plataformatec
-
 defmodule GenEvent do
  # Functions from this module are deprecated in elixir_dispatch.

@@ -36,7 +32,7 @@ defmodule GenEvent do
  alternative. GenStage is an external Elixir library maintained by the Elixir
  team; it provides a tool to implement systems that exchange events in a
  demand-driven way with built-in support for back-pressure. See the [GenStage
-  documentation](https://gen-stage.hexdocs.pm) for more information.
+  documentation](https://hexdocs.pm/gen_stage) for more information.

  ### `:gen_event`

@@ -50,8 +46,8 @@ defmodule GenEvent do
  @callback init(args :: term) ::
              {:ok, state}
              | {:ok, state, :hibernate}
-              | {:error, reason :: term}
-            when state: term
+              | {:error, reason :: any}
+            when state: any

  @callback handle_event(event :: term, state :: term) ::
              {:ok, new_state}
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
José Valim	a2600eace1	Release v1.17.0-rc.0	2024-05-24 12:38:20 +02:00
José Valim	27b6ea82ae	Branch out v1.17	2024-05-24 12:37:32 +02:00