Merge pull request #1269 from ehuss/update-changelog

Update changelog.

.gitattributes

@@ -2,7 +2,7 @@
 
 * text=auto eol=lf
 *.rs rust
-*.woff -text
-*.ttf -text
-*.otf -text
-*.png -text
+*.woff binary
+*.ttf binary
+*.otf binary
+*.png binary

.github/workflows/deploy.yml

@@ -0,0 +1,42 @@
+name: Deploy
+on:
+  release:
+    types: [created]
+
+jobs:
+  release:
+    name: Deploy Release
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+    steps:
+    - uses: actions/checkout@master
+    - name: Install hub
+      run: ci/install-hub.sh ${{ matrix.os }}
+      shell: bash
+    - name: Install Rust
+      run: ci/install-rust.sh stable
+      shell: bash
+    - name: Build and deploy artifacts
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      run: ci/make-release.sh ${{ matrix.os }}
+      shell: bash
+  pages:
+    name: GitHub Pages
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@master
+    - name: Install Rust (rustup)
+      run: rustup update stable --no-self-update && rustup default stable
+    - name: Build book
+      run: cargo run -- build book-example
+    - name: Deploy to GitHub
+      env:
+        GITHUB_DEPLOY_KEY: ${{ secrets.GITHUB_DEPLOY_KEY }}
+      run: |
+        touch book-example/book/.nojekyll
+        curl -LsSf https://raw.githubusercontent.com/rust-lang/simpleinfra/master/setup-deploy-keys/src/deploy.rs | rustc - -o /tmp/deploy
+        cd book-example/book
+        /tmp/deploy

.github/workflows/main.yml

@@ -0,0 +1,51 @@
+name: CI
+on:
+  # Only run when merging to master, or open/synchronize/reopen a PR.
+  push:
+    branches:
+      - master
+  pull_request:
+
+jobs:
+  test:
+    name: Test
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        build: [stable, beta, nightly, macos, windows, msrv]
+        include:
+          - build: stable
+            os: ubuntu-latest
+            rust: stable
+          - build: beta
+            os: ubuntu-latest
+            rust: beta
+          - build: nightly
+            os: ubuntu-latest
+            rust: nightly
+          - build: macos
+            os: macos-latest
+            rust: stable
+          - build: windows
+            os: windows-latest
+            rust: stable
+          - build: msrv
+            os: ubuntu-latest
+            rust: 1.39.0
+    steps:
+    - uses: actions/checkout@master
+    - name: Install Rust
+      run: bash ci/install-rust.sh ${{ matrix.rust }}
+    - name: Build and run tests
+      run: cargo test
+    - name: Test no default
+      run: cargo test --no-default-features
+
+  rustfmt:
+    name: Rustfmt
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@master
+    - name: Install Rust
+      run: rustup update stable && rustup default stable && rustup component add rustfmt
+    - run: cargo fmt -- --check

.gitignore

@@ -9,3 +9,5 @@ book-example/book
 .vscode
 tests/dummy_book/book/
 
+# Ignore Jetbrains specific files.
+.idea/

.travis.yml

@@ -1,48 +0,0 @@
-language: rust
-
-rust:
-  - stable
-  - beta
-  - nightly
-
-os:
-  - linux
-  - osx
-
-cache: 
-  timeout: 360
-  cargo: true
-
-before_cache:
-  - chmod -R a+r $HOME/.cargo
-
-env:
-  global:
-    - CRATE_NAME=mdbook
-
-script:
-  - cargo test --all
-  - cargo test --all --no-default-features
-
-before_deploy:
-  - sh ci/before_deploy.sh
-
-deploy:
-  provider: releases
-  api_key:
-    - secure: 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
-  file_glob: true
-  file: "$CRATE_NAME-$TRAVIS_TAG-$TARGET.*"
-  on:
-    condition: "$TRAVIS_RUST_VERSION = stable"
-    tags: true
-  skip_cleanup: true
-
-branches:
-  only:
-    - master
-    - /^v\d+\.\d+\.\d+.*$/
-
-notifications:
-  email:
-    on_success: never

CHANGELOG.md

@@ -0,0 +1,479 @@
+# Changelog
+
+## mdBook 0.4.1
+[d4df7e7...649f355](https://github.com/rust-lang/mdBook/compare/d4df7e7...649f355)
+
+### Changed
+- Removed several outdated dev-dependencies.
+  [#1267](https://github.com/rust-lang/mdBook/pull/1267)
+
+### Fixed
+- Fixed sidebar scrolling if the book includes part titles.
+  [#1265](https://github.com/rust-lang/mdBook/pull/1265)
+- Don't include the default favicon if only one of the PNG or SVG is overridden.
+  [#1266](https://github.com/rust-lang/mdBook/pull/1266)
+
+## mdBook 0.4.0
+[99ecd4f...d4df7e7](https://github.com/rust-lang/mdBook/compare/99ecd4f...d4df7e7)
+
+### Breaking Changes
+- Several of the changes in the release have altered the public API of the
+  mdbook library.
+- Many dependencies have been updated or replaced.
+  This also removes the `--websocket-hostname` and `--websocket-port` from
+  the `serve` command.
+  [#1211](https://github.com/rust-lang/mdBook/pull/1211)
+- A new "404" page is now automatically rendered. This requires knowledge of
+  the base URL of your site to work properly. If you decide to use this as
+  your 404 page, you should set the `site-url` setting in the book
+  configuration so mdbook can generate the links correctly. Alternatively you
+  can disable the 404 page generation, or set up your own 404 handling in your
+  web server.
+  [#1221](https://github.com/rust-lang/mdBook/pull/1221)
+- If you are using customized themes, you may want to consider setting the
+  `preferred-dark-theme` config setting, as it now defaults to "navy".
+  [#1199](https://github.com/rust-lang/mdBook/pull/1199)
+- "Playpen" has been renamed to "playground". This is generally backwards
+  compatible for users, but `{{#playpen}}` will now display warnings. This may
+  impact books that have modified the "playpen" elements in the theme.
+  [#1241](https://github.com/rust-lang/mdBook/pull/1241)
+- If a renderer is not installed, it is now treated as an error. If you want
+  the old behavior of ignoring missing renderers, set the `optional` setting
+  for that renderer.
+  [#1122](https://github.com/rust-lang/mdBook/pull/1122)
+- If you have a custom favicon, you may need to look into adding an SVG
+  version, otherwise the default SVG icon will be displayed.
+  [#1230](https://github.com/rust-lang/mdBook/pull/1230)
+
+### Added
+- Added a new `[rust]` configuration section to `book.toml`, which allows
+  setting the default edition with `edition = "2018"`.
+  [#1163](https://github.com/rust-lang/mdBook/pull/1163)
+- Renderers can now be marked as `optional`, so that they will be ignored if
+  the renderer is not installed.
+  [#1122](https://github.com/rust-lang/mdBook/pull/1122)
+- Added `head.hbs` to allow adding content to the `<head>` section in HTML.
+  [#1206](https://github.com/rust-lang/mdBook/pull/1206)
+- Added "draft chapters". These are chapters listed without a link to indicate
+  content yet to be written.
+  [#1153](https://github.com/rust-lang/mdBook/pull/1153)
+- Added "parts" to split a book into different sections. Headers can be added
+  to `SUMMARY.md` to signify different sections.
+  [#1171](https://github.com/rust-lang/mdBook/pull/1171)
+- Added generation of a "404" page for handling missing pages and broken links.
+  [#1221](https://github.com/rust-lang/mdBook/pull/1221)
+- Added configuration section for specifying URL redirects.
+  [#1237](https://github.com/rust-lang/mdBook/pull/1237)
+- Added an SVG favicon that works with light and dark colors schemes.
+  [#1230](https://github.com/rust-lang/mdBook/pull/1230)
+
+### Changed
+- Changed default Rust attribute of `allow(unused_variables)` to `allow(unused)`.
+  [#1195](https://github.com/rust-lang/mdBook/pull/1195)
+- Fonts are now served locally instead of from the Google Fonts CDN. The
+  `copy-fonts` option was added to disable this if you want to supply your own
+  fonts.
+  [#1188](https://github.com/rust-lang/mdBook/pull/1188)
+- Switched the built-in webserver for the `serve` command to a new
+  implementation. This results in some internal differences in how websockets
+  are handled, which removes the separate websocket options. This should also
+  make it easier to serve multiple books at once.
+  [#1211](https://github.com/rust-lang/mdBook/pull/1211)
+- The default dark theme is now "navy".
+  [#1199](https://github.com/rust-lang/mdBook/pull/1199)
+- "Playpen" has been renamed to "playground", matching the actual name of the
+  service which was renamed many years ago.
+  [#1241](https://github.com/rust-lang/mdBook/pull/1241)
+
+### Fixed
+- Links with the `+` symbol should now work.
+  [#1208](https://github.com/rust-lang/mdBook/pull/1208)
+- The `MDBOOK_BOOK` environment variable now correctly allows overriding the
+  entire book configuration.
+  [#1207](https://github.com/rust-lang/mdBook/pull/1207)
+- The sidebar can no longer be dragged outside of the window.
+  [#1229](https://github.com/rust-lang/mdBook/pull/1229)
+- Hide the Rust Playground "play" button for `no_run` code samples.
+  [#1249](https://github.com/rust-lang/mdBook/pull/1249)
+- Fixed the `--dest-dir` command-line option for the `serve` and `watch`
+  commands.
+  [#1228](https://github.com/rust-lang/mdBook/pull/1228)
+- Hotkey handlers are now disabled in `text` input fields (for example, typing
+  `S` in a custom text input field).
+  [#1244](https://github.com/rust-lang/mdBook/pull/1244)
+
+## mdBook 0.3.7
+[88684d8...99ecd4f](https://github.com/rust-lang/mdBook/compare/88684d8...99ecd4f)
+
+### Changed
+- Code spans in headers are no longer highlighted as code.
+  [#1162](https://github.com/rust-lang/mdBook/pull/1162)
+- The sidebar will now scroll the activate page to the middle instead of the top.
+  [#1161](https://github.com/rust-lang/mdBook/pull/1161)
+- Reverted change to reject build output within the `src` directory, and
+  instead add a check that prevents infinite copies.
+  [#1181](https://github.com/rust-lang/mdBook/pull/1181)
+  [#1026](https://github.com/rust-lang/mdBook/pull/1026)
+
+### Fixed
+- Fixed sidebar line-height jumping for collapsed chapters.
+  [#1182](https://github.com/rust-lang/mdBook/pull/1182)
+- Fixed theme selector focus.
+  [#1170](https://github.com/rust-lang/mdBook/pull/1170)
+
+## mdBook 0.3.6
+[efdb832...88684d8](https://github.com/rust-lang/mdBook/compare/efdb832...88684d8)
+
+### Added
+- `MDBook::execute_build_process` is now publicly accessible in the API so
+  that plugins can more easily initiate the build process.
+  [#1099](https://github.com/rust-lang/mdBook/pull/1099)
+
+### Changed
+- Use a different color for Ayu theme's highlighting for Rust attributes (uses
+  a bright color instead of the comment color).
+  [#1133](https://github.com/rust-lang/mdBook/pull/1133)
+- Adjusted spacing of sidebar entries.
+  [#1137](https://github.com/rust-lang/mdBook/pull/1137)
+- Slightly adjusted line-height of `<p>`, `<ul>`, and `<ol>`.
+  [#1136](https://github.com/rust-lang/mdBook/pull/1136)
+- Handlebars updated to 3.0.
+  [#1130](https://github.com/rust-lang/mdBook/pull/1130)
+
+### Fixed
+- Fix an issue with sidebar scroll position on reload.
+  [#1108](https://github.com/rust-lang/mdBook/pull/1108)
+- `mdbook serve` will retain the current scroll position when the page is reloaded.
+  [#1097](https://github.com/rust-lang/mdBook/pull/1097)
+- Fixed the page name if the book didn't have a title to not be prefixed with ` - `.
+  [#1145](https://github.com/rust-lang/mdBook/pull/1145)
+- HTML attributes `rel=next` and `rel=previous` are now supported in "wide"
+  mode (previously they were only set in narrow mode).
+  [#1150](https://github.com/rust-lang/mdBook/pull/1150)
+- Prevent recursive copies when the destination directory is contained in the
+  source directory.
+  [#1135](https://github.com/rust-lang/mdBook/pull/1135)
+- Adjusted the menu bar animation to not immediately obscure the top content.
+  [#989](https://github.com/rust-lang/mdBook/pull/989)
+- Fix for comments in SUMMARY.md that appear between items.
+  [#1167](https://github.com/rust-lang/mdBook/pull/1167)
+
+## mdBook 0.3.5
+[6e0d0fa...efdb832](https://github.com/rust-lang/mdBook/compare/6e0d0fa...efdb832)
+
+### Changed
+- The `default-theme` config setting is now case-insensitive.
+  [#1079](https://github.com/rust-lang/mdBook/pull/1079)
+
+### Fixed
+- Fixed `#` hidden Rust code lines not rendering properly.
+  [#1088](https://github.com/rust-lang/mdBook/pull/1088)
+- Updated pulldown-cmark to 0.6.1, fixing several issues.
+  [#1021](https://github.com/rust-lang/mdBook/pull/1021)
+
+## mdBook 0.3.4
+[e5f77aa...6e0d0fa](https://github.com/rust-lang/mdBook/compare/e5f77aa...6e0d0fa)
+
+### Changed
+- Switch to relative `rem` font sizes from `px`.
+  [#894](https://github.com/rust-lang/mdBook/pull/894)
+- Migrated repository to https://github.com/rust-lang/mdBook/
+  [#1083](https://github.com/rust-lang/mdBook/pull/1083)
+
+## mdBook 0.3.3
+[2b649fe...e5f77aa](https://github.com/rust-lang/mdBook/compare/2b649fe...e5f77aa)
+
+### Changed
+- Improvements to the automatic dark theme selection.
+  [#1069](https://github.com/rust-lang/mdBook/pull/1069)
+- Fragment links now prevent scrolling the header behind the menu bar.
+  [#1077](https://github.com/rust-lang/mdBook/pull/1077)
+
+### Fixed
+- Fixed error when building a book that has a spacer immediately after the
+  first chapter.
+  [#1075](https://github.com/rust-lang/mdBook/pull/1075)
+
+## mdBook 0.3.2
+[9cd47eb...2b649fe](https://github.com/rust-lang/mdBook/compare/9cd47eb...2b649fe)
+
+### Added
+- Added a markdown renderer, which is off by default. This may be useful for
+  debugging preprocessors.
+  [#1018](https://github.com/rust-lang/mdBook/pull/1018)
+- Code samples may now include line numbers with the
+  `output.html.playpen.line-numbers` configuration value.
+  [#1035](https://github.com/rust-lang/mdBook/pull/1035)
+- The `watch` and `serve` commands will now ignore files listed in
+  `.gitignore`.
+  [#1044](https://github.com/rust-lang/mdBook/pull/1044)
+- Added automatic dark-theme detection based on the CSS `prefers-color-scheme`
+  feature. This may be enabled by setting `output.html.preferred-dark-theme`
+  to your preferred dark theme.
+  [#1037](https://github.com/rust-lang/mdBook/pull/1037)
+- Added `rustdoc_include` preprocessor. This makes it easier to include
+  portions of an external Rust source file. The rest of the file is hidden,
+  but the user may expand it to see the entire file, and will continue to work
+  with `mdbook test`.
+  [#1003](https://github.com/rust-lang/mdBook/pull/1003)
+- Added Ctrl-Enter shortcut to the playpen editor to automatically run the
+  sample.
+  [#1066](https://github.com/rust-lang/mdBook/pull/1066)
+- Added `output.html.playpen.copyable` configuration option to disable
+  the copy button.
+  [#1050](https://github.com/rust-lang/mdBook/pull/1050)
+- Added ability to dynamically expand and fold sections within the sidebar.
+  See the `output.html.fold` configuration to enable this feature.
+  [#1027](https://github.com/rust-lang/mdBook/pull/1027)
+
+### Changed
+- Use standard `scrollbar-color` CSS along with webkit extension
+  [#816](https://github.com/rust-lang/mdBook/pull/816)
+- The renderer build directory is no longer deleted before the renderer is
+  run. This allows a backend to cache results between runs.
+  [#985](https://github.com/rust-lang/mdBook/pull/985)
+- Next/prev links now highlight on hover to indicate it is clickable.
+  [#994](https://github.com/rust-lang/mdBook/pull/994)
+- Increase padding of table headers.
+  [#824](https://github.com/rust-lang/mdBook/pull/824)
+- Errors in `[output.html]` config are no longer ignored.
+  [#1033](https://github.com/rust-lang/mdBook/pull/1033)
+- Updated highlight.js for syntax highlighting updates (primarily to add
+  async/await to Rust highlighting).
+  [#1041](https://github.com/rust-lang/mdBook/pull/1041)
+- Raised minimum supported rust version to 1.35.
+  [#1003](https://github.com/rust-lang/mdBook/pull/1003)
+- Hidden code lines are no longer dynamically removed via JavaScript, but
+  instead managed with CSS.
+  [#846](https://github.com/rust-lang/mdBook/pull/846)
+  [#1065](https://github.com/rust-lang/mdBook/pull/1065)
+- Changed the default font set for the ACE editor, giving preference to
+  "Source Code Pro".
+  [#1062](https://github.com/rust-lang/mdBook/pull/1062)
+- Windows 32-bit releases are no longer published.
+  [#1071](https://github.com/rust-lang/mdBook/pull/1071)
+
+### Fixed
+- Fixed sidebar auto-scrolling.
+  [#1052](https://github.com/rust-lang/mdBook/pull/1052)
+- Fixed error message when running `clean` multiple times.
+  [#1055](https://github.com/rust-lang/mdBook/pull/1055)
+- Actually fix the "next" link on index.html. The previous fix didn't work.
+  [#1005](https://github.com/rust-lang/mdBook/pull/1005)
+- Stop using `inline-block` for `inline code`, fixing selection highlighting
+  and some rendering issues.
+  [#1058](https://github.com/rust-lang/mdBook/pull/1058)
+- Fix header auto-hide on browsers with momentum scrolling that allows
+  negative `scrollTop`.
+  [#1070](https://github.com/rust-lang/mdBook/pull/1070)
+
+## mdBook 0.3.1
+[69a08ef...9cd47eb](https://github.com/rust-lang/mdBook/compare/69a08ef...9cd47eb)
+
+### Added
+- 🔥 Added ability to include files using anchor points instead of line numbers.
+  [#851](https://github.com/rust-lang/mdBook/pull/851)
+- Added `language` configuration value to set the language of the book, which
+  will affect things like the `<html lang="en">` tag.
+  [#941](https://github.com/rust-lang/mdBook/pull/941)
+
+### Changed
+- Updated to handlebars 2.0.
+  [#977](https://github.com/rust-lang/mdBook/pull/977)
+
+### Fixed
+- Fixed memory leak warning.
+  [#967](https://github.com/rust-lang/mdBook/pull/967)
+- Fix more print.html links.
+  [#963](https://github.com/rust-lang/mdBook/pull/963)
+- Fixed crash on some unicode input.
+  [#978](https://github.com/rust-lang/mdBook/pull/978)
+
+## mdBook 0.3.0
+[6cbc41d...69a08ef](https://github.com/rust-lang/mdBook/compare/6cbc41d...69a08ef)
+
+### Added
+- Added ability to resize the sidebar.
+  [#849](https://github.com/rust-lang/mdBook/pull/849)
+- Added `load_with_config_and_summary` function to `MDBook` to be able to
+  build a book with a custom `Summary`.
+  [#883](https://github.com/rust-lang/mdBook/pull/883)
+- Set `noindex` on `print.html` page to prevent robots from indexing it.
+  [#844](https://github.com/rust-lang/mdBook/pull/844)
+- Added support for ~~strikethrough~~ and GitHub-style tasklists.
+  [#952](https://github.com/rust-lang/mdBook/pull/952)
+
+### Changed
+- Command-line help output is now colored.
+  [#861](https://github.com/rust-lang/mdBook/pull/861)
+- The build directory is now deleted before rendering starts, instead of after
+  if finishes.
+  [#878](https://github.com/rust-lang/mdBook/pull/878)
+- Removed dependency on `same-file` crate.
+  [#903](https://github.com/rust-lang/mdBook/pull/903)
+- 💥 Renamed `with_preprecessor` to `with_preprocessor`.
+  [#906](https://github.com/rust-lang/mdBook/pull/906)
+- Updated ACE editor to 1.4.4, should remove a JavaScript console warning.
+  [#935](https://github.com/rust-lang/mdBook/pull/935)
+- Dependencies have been updated.
+  [#934](https://github.com/rust-lang/mdBook/pull/934)
+  [#945](https://github.com/rust-lang/mdBook/pull/945)
+- Highlight.js has been updated. This fixes some TOML highlighting, and adds
+  Julia support.
+  [#942](https://github.com/rust-lang/mdBook/pull/942)
+- 🔥 Updated to pulldown-cmark 0.5. This may have significant changes to the
+  formatting of existing books, as the newer version has more accurate
+  interpretation of the CommonMark spec and a large number of bug fixes and
+  changes.
+  [#898](https://github.com/rust-lang/mdBook/pull/898)
+- The `diff` language should now highlight correctly.
+  [#943](https://github.com/rust-lang/mdBook/pull/943)
+- Make the blank region of a header not clickable.
+  [#948](https://github.com/rust-lang/mdBook/pull/948)
+- Rustdoc tests now use the preprocessed content instead of the raw,
+  unpreprocessed content.
+  [#891](https://github.com/rust-lang/mdBook/pull/891)
+
+### Fixed
+- Fixed file change detection so that `mdbook serve` only reloads once when
+  multiple files are changed at once.
+  [#870](https://github.com/rust-lang/mdBook/pull/870)
+- Fixed on-hover color highlighting for links in sidebar.
+  [#834](https://github.com/rust-lang/mdBook/pull/834)
+- Fixed loss of focus when clicking the "Copy" button in code blocks.
+  [#867](https://github.com/rust-lang/mdBook/pull/867)
+- Fixed incorrectly stripping the path for `additional-js` files.
+  [#796](https://github.com/rust-lang/mdBook/pull/796)
+- Fixed color of `code spans` that are links.
+  [#905](https://github.com/rust-lang/mdBook/pull/905)
+- Fixed "next" navigation on index.html.
+  [#916](https://github.com/rust-lang/mdBook/pull/916)
+- Fixed keyboard chapter navigation for `file` urls.
+  [#915](https://github.com/rust-lang/mdBook/pull/915)
+- Fixed bad wrapping for inline code on some browsers.
+  [#818](https://github.com/rust-lang/mdBook/pull/818)
+- Properly load an existing `SUMMARY.md` in `mdbook init`.
+  [#841](https://github.com/rust-lang/mdBook/pull/841)
+- Fixed some broken links in `print.html`.
+  [#871](https://github.com/rust-lang/mdBook/pull/871)
+- The Rust Playground link now supports the 2018 edition.
+  [#946](https://github.com/rust-lang/mdBook/pull/946)
+
+## mdBook 0.2.3 (2018-01-18)
+[2c20c99...6cbc41d](https://github.com/rust-lang/mdBook/compare/2c20c99...6cbc41d)
+
+### Added
+- Added an optional button to the top of the page which will link to a git
+  repository. Use the `git-repository-url` and `git-repository-icon` options
+  in the `[output.html]` section to enable it and set its appearance.
+  [#802](https://github.com/rust-lang/mdBook/pull/802)
+- Added a `default-theme` option to the `[output.html]` section.
+  [#804](https://github.com/rust-lang/mdBook/pull/804)
+
+### Changed
+- 💥 Header ID anchors no longer add an arbitrary `a` character for headers
+  that start with a non-ascii-alphabetic character.
+  [#788](https://github.com/rust-lang/mdBook/pull/788)
+
+### Fixed
+- Fix websocket hostname usage
+  [#865](https://github.com/rust-lang/mdBook/pull/865)
+- Fixing links in print.html
+  [#866](https://github.com/rust-lang/mdBook/pull/866)
+
+## mdBook 0.2.2 (2018-10-19)
+[7e2e095...2c20c99](https://github.com/rust-lang/mdBook/compare/7e2e095...2c20c99)
+
+### Added
+- 🎉 Process-based custom preprocessors. See [the
+  docs](https://rust-lang.github.io/mdBook/for_developers/preprocessors.html)
+  for more.
+  [#792](https://github.com/rust-lang/mdBook/pull/792)
+
+- 🎉 Configurable preprocessors.
+
+  Added `build.use-default-preprocessors` boolean TOML key to allow disabling
+  the built-in `links` and `index` preprocessors.
+
+  Added `[preprocessor]` TOML tables to configure each preprocessor.
+
+  Specifying `[preprocessor.links]` or `[preprocessor.index]` will enable the
+  respective built-in preprocessor if `build.use-default-preprocessors` is
+  `false`.
+
+  Added `fn supports_renderer(&self, renderer: &str) -> bool` to the
+  `Preprocessor` trait to specify if the preprocessor supports the given
+  renderer. The default implementation always returns `true`.
+
+  `Preprocessor::run` now takes a book by value instead of a mutable
+  reference. It should return a `Book` value with the intended modifications.
+
+  Added `PreprocessorContext::renderer` to indicate the renderer being used.
+
+  [#658](https://github.com/rust-lang/mdBook/pull/658)
+  [#787](https://github.com/rust-lang/mdBook/pull/787)
+
+### Fixed
+- Fix paths to additional CSS and JavaScript files
+  [#777](https://github.com/rust-lang/mdBook/pull/777)
+- Ensure section numbers are correctly incremented after a horizontal
+  separator
+  [#790](https://github.com/rust-lang/mdBook/pull/790)
+
+## mdBook 0.2.1 (2018-08-22)
+[91ffca1...7e2e095](https://github.com/rust-lang/mdBook/compare/91ffca1...7e2e095)
+
+### Changed
+- Update to handlebars-rs 1.0
+  [#761](https://github.com/rust-lang/mdBook/pull/761)
+
+### Fixed
+- Fix table colors, broken by Stylus -> CSS transition
+  [#765](https://github.com/rust-lang/mdBook/pull/765)
+
+## mdBook 0.2.0 (2018-08-02)
+
+### Changed
+- 💥 This release changes how links are handled in mdBook. Previously, relative
+  links were interpreted relative to the book's root. In `0.2.0`+ links are
+  relative to the page they are in, and use the `.md` extension. This has [several
+  advantages](https://github.com/rust-lang/mdBook/pull/603#issue-166701447),
+  such as making links work in other markdown viewers like GitHub. You will
+  likely have to change links in your book to accommodate this change. For
+  example, a book with this layout:
+
+  ```
+  chapter_1/
+      section_1.md
+      section_2.md
+  SUMMARY.md
+  ```
+
+  Previously a link in `section_1.md` to `section_2.md` would look like this:
+  ```markdown
+  [section_2](chapter_1/section_2.html)
+  ```
+
+  Now it must be changed to this:
+  ```markdown
+  [section_2](section_2.md)
+  ```
+
+- 💥 `mdbook test --library-path` now accepts a comma-delimited list of
+  arguments rather than taking all following arguments. This makes it easier
+  to handle the trailing book directory argument without always needing to put
+  ` -- ` before it. Multiple instances of the option continue to be accepted:
+  `mdbook test -L foo -L bar`.
+
+- 💥 `mdbook serve` has some of its options renamed for clarity. See `mdbook
+  help serve` for details.
+
+- Embedded rust playpens now use the "stable" playground API.
+  [#754](https://github.com/rust-lang/mdBook/pull/754)
+
+### Fixed
+- Escaped includes (`\{{#include file.rs}}`) will now render correctly.
+  [f30ce01](https://github.com/rust-lang/mdBook/commit/f30ce0184d71e342141145472bf816419d30a2c5)
+- `index.html` will now render correctly when the book's first section is
+  inside a subdirectory.
+  [#756](https://github.com/rust-lang/mdBook/pull/756)

CONTRIBUTING.md

@@ -5,22 +5,22 @@ Welcome stranger!
 If you have come here to learn how to contribute to mdBook, we have some tips for you!
 
 First of all, don't hesitate to ask questions!
-Use the [issue tracker](https://github.com/rust-lang-nursery/mdBook/issues), no question is too simple.
+Use the [issue tracker](https://github.com/rust-lang/mdBook/issues), no question is too simple.
 If we don't respond in a couple of days, ping us @Michael-F-Bryan, @budziq, @steveklabnik, @frewsxcv it might just be that we forgot. :wink:
 
 ### Issues to work on
 
 Any issue is up for the grabbing, but if you are starting out, you might be interested in the
-[E-Easy issues](https://github.com/rust-lang-nursery/mdBook/issues?q=is%3Aopen+is%3Aissue+label%3AE-Easy).
+[E-Easy issues](https://github.com/rust-lang/mdBook/issues?q=is%3Aopen+is%3Aissue+label%3AE-Easy).
 Those are issues that are considered more straightforward for beginners to Rust or the codebase itself.
 These issues can be a good launching pad for more involved issues. Easy tasks for a first time contribution
 include documentation improvements, new tests, examples, updating dependencies, etc.
 
 If you come from a web development background, you might be interested in issues related to web technologies tagged
-[A-JavaScript](https://github.com/rust-lang-nursery/mdBook/issues?q=is%3Aopen+is%3Aissue+label%3AA-JavaScript),
-[A-Style](https://github.com/rust-lang-nursery/mdBook/issues?q=is%3Aopen+is%3Aissue+label%3AA-Style),
-[A-HTML](https://github.com/rust-lang-nursery/mdBook/issues?q=is%3Aopen+is%3Aissue+label%3AA-HTML) or
-[A-Mobile](https://github.com/rust-lang-nursery/mdBook/issues?q=is%3Aopen+is%3Aissue+label%3AA-Mobile).
+[A-JavaScript](https://github.com/rust-lang/mdBook/issues?q=is%3Aopen+is%3Aissue+label%3AA-JavaScript),
+[A-Style](https://github.com/rust-lang/mdBook/issues?q=is%3Aopen+is%3Aissue+label%3AA-Style),
+[A-HTML](https://github.com/rust-lang/mdBook/issues?q=is%3Aopen+is%3Aissue+label%3AA-HTML) or
+[A-Mobile](https://github.com/rust-lang/mdBook/issues?q=is%3Aopen+is%3Aissue+label%3AA-Mobile).
 
 When you decide you want to work on a specific issue, ping us on that issue so that we can assign it to you.
 Again, do not hesitate to ask questions. We will gladly mentor anyone that want to tackle an issue.
@@ -41,7 +41,7 @@ mdBook builds on stable Rust, if you want to build mdBook from source, here are
 0. Clone this repository with git.
 
    ```
-   git clone https://github.com/rust-lang-nursery/mdBook.git
+   git clone https://github.com/rust-lang/mdBook.git
    ```
 0. Navigate into the newly created `mdBook` directory
 0. Run `cargo build`
@@ -57,12 +57,12 @@ We love code quality and Rust has some excellent tools to assist you with contri
 Before you make your Pull Request to the project, please run it through the `rustfmt` utility.
 This will ensure we have good quality source code that is better for us all to maintain.
 
-[rustfmt](https://github.com/rust-lang-nursery/rustfmt) has a lot more information on the project.
+[rustfmt](https://github.com/rust-lang/rustfmt) has a lot more information on the project.
 The quick guide is
 
 1. Install it
     ```
-    rustup component add rustfmt-preview
+    rustup component add rustfmt
     ```
 1. You can now run `rustfmt` on a single file simply by...
     ```
@@ -74,7 +74,7 @@ The quick guide is
    ```
    When run through `cargo` it will format all bin and lib files in the current crate.
 
-For more information, such as running it from your favourite editor, please see the `rustfmt` project. [rustfmt](https://github.com/rust-lang-nursery/rustfmt)
+For more information, such as running it from your favourite editor, please see the `rustfmt` project. [rustfmt](https://github.com/rust-lang/rustfmt)
 
 
 #### Finding Issues with Clippy
@@ -83,21 +83,18 @@ Clippy is a code analyser/linter detecting mistakes, and therfore helps to impro
 Like formatting your code with `rustfmt`, running clippy regularly and before your Pull Request will
 help us maintain awesome code.
 
-The best documentation can be found over at [rust-clippy](https://github.com/rust-lang-nursery/rust-clippy)
+The best documentation can be found over at [rust-clippy](https://github.com/rust-lang/rust-clippy)
 
 1. To install
     ```
-    rustup update
-    rustup install nightly
-    rustup component add clippy-preview --toolchain=nightly
+    rustup component add clippy
     ```
 2. Running clippy
-    As you may notice from the previous step, Clippy is on the nightly branch, so running it is like
     ```
-    cargo +nightly clippy
+    cargo clippy
     ```
 
-Clippy has an ever growing list of checks, that are managed in [lint files](https://rust-lang-nursery.github.io/rust-clippy/master/index.html).
+Clippy has an ever growing list of checks, that are managed in [lint files](https://rust-lang.github.io/rust-clippy/master/index.html).
 
 ### Making a pull-request
 
@@ -105,7 +102,7 @@ When you feel comfortable that your changes could be integrated into mdBook, you
 One of the core maintainers will then approve the changes or request some changes before it gets merged.
 
 If you want to make your pull-request even better, you might want to run [Clippy](https://github.com/Manishearth/rust-clippy)
-and [rustfmt](https://github.com/rust-lang-nursery/rustfmt) on the code first.
+and [rustfmt](https://github.com/rust-lang/rustfmt) on the code first.
 This is not a requirement though and will never block a pull-request from being merged.
 
 That's it, happy contributions! :tada: :tada: :tada:

Cargo.toml

@@ -1,64 +1,61 @@
 [package]
 name = "mdbook"
-version = "0.2.2-alpha.0"
+version = "0.4.1"
 authors = [
-    "Mathieu David <mathieudavid@mathieudavid.org>", 
+    "Mathieu David <mathieudavid@mathieudavid.org>",
     "Michael-F-Bryan <michaelfbryan@gmail.com>",
     "Matt Ickstadt <mattico8@gmail.com>"
 ]
-description = "Create books from markdown files"
-documentation = "http://rust-lang-nursery.github.io/mdBook/index.html"
-repository = "https://github.com/rust-lang-nursery/mdBook"
+documentation = "http://rust-lang.github.io/mdBook/index.html"
+edition = "2018"
+exclude = ["/book-example/*"]
 keywords = ["book", "gitbook", "rustbook", "markdown"]
 license = "MPL-2.0"
 readme = "README.md"
-exclude = ["book-example/*"]
+repository = "https://github.com/rust-lang/mdBook"
+description = "Creates a book from markdown files"
 
 [dependencies]
-clap = "2.24"
+anyhow = "1.0.28"
 chrono = "0.4"
-handlebars = "1.0"
-serde = "1.0"
-serde_derive = "1.0"
-error-chain = "0.12"
-serde_json = "1.0"
-pulldown-cmark = "0.1.2"
+clap = "2.24"
+env_logger = "0.7.1"
+handlebars = "3.0"
 lazy_static = "1.0"
 log = "0.4"
-env_logger = "0.5"
-toml = "0.4"
 memchr = "2.0"
 open = "1.1"
+pulldown-cmark = "0.7.0"
 regex = "1.0.0"
-tempfile = "3.0"
-itertools = "0.7"
+serde = "1.0"
+serde_derive = "1.0"
+serde_json = "1.0"
 shlex = "0.1"
-toml-query = "0.7"
+tempfile = "3.0"
+toml = "0.5.1"
 
 # Watch feature
 notify = { version = "4.0", optional = true }
+gitignore = { version = "1.0", optional = true }
 
 # Serve feature
-iron = { version = "0.6", optional = true }
-staticfile = { version = "0.5", optional = true }
-ws = { version = "0.7", optional = true}
+futures-util = { version = "0.3.4", optional = true }
+tokio = { version = "0.2.18", features = ["macros"], optional = true }
+warp = { version = "0.2.2", default-features = false, features = ["websocket"], optional = true }
 
 # Search feature
 elasticlunr-rs = { version = "2.3", optional = true, default-features = false }
-ammonia = { version = "1.1", optional = true }
+ammonia = { version = "3", optional = true }
 
 [dev-dependencies]
-select = "0.4"
-pretty_assertions = "0.5"
+select = "0.5"
+pretty_assertions = "0.6"
 walkdir = "2.0"
-pulldown-cmark-to-cmark = "1.1.0"
 
 [features]
-default = ["output", "watch", "serve", "search"]
-debug = []
-output = []
-watch = ["notify"]
-serve = ["iron", "staticfile", "ws"]
+default = ["watch", "serve", "search"]
+watch = ["notify", "gitignore"]
+serve = ["futures-util", "tokio", "warp"]
 search = ["elasticlunr-rs", "ammonia"]
 
 [[bin]]

README.md

@@ -1,25 +1,8 @@
 # mdBook
 
-<table>
-    <tr>
-        <td><strong>Linux / OS X</strong></td>
-        <td>
-            <a href="https://travis-ci.org/rust-lang-nursery/mdBook"><img src="https://travis-ci.org/rust-lang-nursery/mdBook.svg?branch=master"></a>
-        </td>
-    </tr>
-    <tr>
-        <td><strong>Windows</strong></td>
-        <td>
-            <a href="https://ci.appveyor.com/project/rust-lang-libs/mdbook"><img src="https://ci.appveyor.com/api/projects/status/ysyke2rvo85sni55?svg=true"></a>
-        </td>
-    </tr>
-    <tr>
-        <td colspan="2">
-            <a href="https://crates.io/crates/mdbook"><img src="https://img.shields.io/crates/v/mdbook.svg"></a>
-            <a href="LICENSE"><img src="https://img.shields.io/github/license/rust-lang-nursery/mdBook.svg"></a>
-        </td>
-    </tr>
-</table>
+[![Build Status](https://github.com/rust-lang/mdBook/workflows/CI/badge.svg?event=push)](https://github.com/rust-lang/mdBook/actions?workflow=CI)
+[![crates.io](https://img.shields.io/crates/v/mdbook.svg)](https://crates.io/crates/mdbook)
+[![LICENSE](https://img.shields.io/github/license/rust-lang/mdBook.svg)](LICENSE)
 
 mdBook is a utility to create modern online books from Markdown files.
 
@@ -41,7 +24,7 @@ There are multiple ways to install mdBook.
 
 2. **From Crates.io**
 
-   This requires at least [Rust] 1.20 and Cargo to be installed. Once you have installed
+   This requires at least [Rust] 1.39 and Cargo to be installed. Once you have installed
    Rust, type the following in the terminal:
 
    ```
@@ -57,33 +40,37 @@ There are multiple ways to install mdBook.
    another CI server, we recommend that you specify a semver version range for
    mdBook when you install it through your script!
 
-   This will constrain the server to install the latests **non-breaking**
+   This will constrain the server to install the latest **non-breaking**
    version of mdBook and will prevent your books from failing to build because
-   we released a new version. For example:
+   we released a new version.
+
+   You can also disable default features to speed up compile time.
+
+   Example:
 
    ```
-   cargo install mdbook --vers "^0.1.0"
+   cargo install mdbook --no-default-features --features output --vers "^0.1.0"
    ```
 
-3. **From Git**  
+3. **From Git**
 
    The version published to crates.io will ever so slightly be behind the
    version hosted here on GitHub. If you need the latest version you can build
    the git version of mdBook yourself. Cargo makes this ***super easy***!
 
    ```
-   cargo install --git https://github.com/rust-lang-nursery/mdBook.git mdbook
+   cargo install --git https://github.com/rust-lang/mdBook.git mdbook
    ```
 
    Again, make sure to add the Cargo bin directory to your `PATH`.
 
-4. **For Contributions**  
+4. **For Contributions**
 
    If you want to contribute to mdBook you will have to clone the repository on
    your local machine:
 
    ```
-   git clone https://github.com/rust-lang-nursery/mdBook.git
+   git clone https://github.com/rust-lang/mdBook.git
    ```
 
    `cd` into `mdBook/` and run
@@ -152,16 +139,16 @@ party plugins. These plugins are just programs which will be invoked during the
 build process and are split into roughly two categories, *preprocessors* and
 *renderers*.
 
-Preprocessors are used to transform a book before it is sent to a renderer. 
-One example would be to replace all occurrences of 
-`{{#include some_file.ext}}` with the contents of that file. Some existing 
+Preprocessors are used to transform a book before it is sent to a renderer.
+One example would be to replace all occurrences of
+`{{#include some_file.ext}}` with the contents of that file. Some existing
 preprocessors are:
 
 - `index` - a built-in preprocessor (enabled by default) which will transform
   all `README.md` chapters to `index.md` so `foo/README.md` can be accessed via
   the url `foo/` when published to a browser
 - `links` - a built-in preprocessor (enabled by default) for expanding the
-  `{{# playpen}}` and `{{# include}}` helpers in a chapter.
+  `{{# playground}}` and `{{# include}}` helpers in a chapter.
 
 Renderers are given the final book so they can do something with it. This is
 typically used for, as the name suggests, rendering the document in a particular
@@ -169,6 +156,9 @@ format, however there's nothing stopping a renderer from doing static analysis
 of a book in order to validate links or run tests. Some existing renderers are:
 
 - `html` - the built-in renderer which will generate a HTML version of the book
+- `markdown` - the built-in renderer (disabled by default) which will run
+  preprocessors then output the resulting Markdown. Useful for debugging
+  preprocessors.
 - [`linkcheck`] - a backend which will check that all links are valid
 - [`epub`] - an experimental EPUB generator
 
@@ -214,7 +204,7 @@ Contributions are highly appreciated and encouraged! Don't hesitate to
 participate to discussions in the issues, propose new features and ask for
 help.
 
-If you are just starting out with Rust, there are a series of issus that are
+If you are just starting out with Rust, there are a series of issues that are
 tagged [E-Easy] and **we will gladly mentor you** so that you can successfully
 go through the process of fixing a bug or adding a new feature! Let us know if
 you need any help.
@@ -231,14 +221,14 @@ available, for those hacking on `master`.
 All the code in this repository is released under the ***Mozilla Public License v2.0***, for more information take a look at the [LICENSE] file.
 
 
-[User Guide]: https://rust-lang-nursery.github.io/mdBook/
+[User Guide]: https://rust-lang.github.io/mdBook/
 [API docs]: https://docs.rs/mdbook/*/mdbook/
-[E-Easy]: https://github.com/rust-lang-nursery/mdBook/issues?q=is%3Aopen+is%3Aissue+label%3AE-Easy
-[contribution guide]: https://github.com/rust-lang-nursery/mdBook/blob/master/CONTRIBUTING.md
-[LICENSE]: https://github.com/rust-lang-nursery/mdBook/blob/master/LICENSE
-[releases]: https://github.com/rust-lang-nursery/mdBook/releases
+[E-Easy]: https://github.com/rust-lang/mdBook/issues?q=is%3Aopen+is%3Aissue+label%3AE-Easy
+[contribution guide]: https://github.com/rust-lang/mdBook/blob/master/CONTRIBUTING.md
+[LICENSE]: https://github.com/rust-lang/mdBook/blob/master/LICENSE
+[releases]: https://github.com/rust-lang/mdBook/releases
 [Rust]: https://www.rust-lang.org/
-[CLI docs]: http://rust-lang-nursery.github.io/mdBook/cli/init.html
-[master-docs]: http://rust-lang-nursery.github.io/mdBook/mdbook/
+[CLI docs]: http://rust-lang.github.io/mdBook/cli/init.html
+[master-docs]: http://rust-lang.github.io/mdBook/
 [`linkcheck`]: https://crates.io/crates/mdbook-linkcheck
-[`epub`]: https://crates.io/crates/mdbook-epub
+[`epub`]: https://crates.io/crates/mdbook-epub

appveyor.yml

@@ -1,64 +0,0 @@
-environment:
-  global:
-    PROJECT_NAME: mdBook
-  matrix:
-    # Stable channel
-    - TARGET: i686-pc-windows-msvc
-      RUST_CHANNEL: stable
-    - TARGET: x86_64-pc-windows-msvc
-      RUST_CHANNEL: stable
-    # Beta channel
-    - TARGET: i686-pc-windows-msvc
-      RUST_CHANNEL: beta
-    - TARGET: x86_64-pc-windows-msvc
-      RUST_CHANNEL: beta
-    # Nightly channel
-    - TARGET: i686-pc-windows-msvc
-      RUST_CHANNEL: nightly
-    - TARGET: x86_64-pc-windows-msvc
-      RUST_CHANNEL: nightly
-
-# Install Rust and Cargo
-install:
-  - ps: >-
-      If ($Env:TARGET -eq 'x86_64-pc-windows-gnu') {
-        $Env:PATH += ';C:\msys64\mingw64\bin'
-      } ElseIf ($Env:TARGET -eq 'i686-pc-windows-gnu') {
-        $Env:PATH += ';C:\msys64\mingw32\bin'
-      }
-  - curl -sSf -o rustup-init.exe https://win.rustup.rs/
-  - rustup-init.exe -y --default-host %TARGET% --default-toolchain %RUST_CHANNEL%
-  - set PATH=%PATH%;C:\Users\appveyor\.cargo\bin
-  - rustc -Vv
-  - cargo -V
-
-build: false
-
-# Equivalent to Travis' `script` phase
-test_script:
-  - cargo test --all
-  - cargo test --all --no-default-features
-
-before_deploy:
-  # Generate artifacts for release
-  - cargo rustc --bin mdbook --release -- -C lto
-  - mkdir staging
-  - copy target\release\mdbook.exe staging
-  - cd staging
-  - 7z a ../%PROJECT_NAME%-%APPVEYOR_REPO_TAG_NAME%-%TARGET%.zip *
-  - appveyor PushArtifact ../%PROJECT_NAME%-%APPVEYOR_REPO_TAG_NAME%-%TARGET%.zip
-
-deploy:
-  description: 'Windows release'
-  artifact: /.*\.zip/
-  auth_token:
-    secure: QQhjKVyz7mpjlyGhlXytbFQQfKFQWTahHkD+B0NzIUoEVqO7ZLWjnoWasvLqW4nE
-  provider: GitHub
-  on:
-    RUST_CHANNEL: stable
-    appveyor_repo_tag: true
-
-branches:
-  only:
-    - master
-    - /^v\d+\.\d+\.\d+.*$/

book-example/book.toml

@@ -2,12 +2,18 @@
 title = "mdBook Documentation"
 description = "Create book from markdown files. Like Gitbook but implemented in Rust"
 authors = ["Mathieu David", "Michael-F-Bryan"]
+language = "en"
+
+[rust]
+edition = "2018"
 
 [output.html]
 mathjax-support = true
+site-url = "/mdBook/"
 
-[output.html.playpen]
+[output.html.playground]
 editable = true
+line-numbers = true
 
 [output.html.search]
 limit-results = 20

book-example/src/404.md

@@ -0,0 +1,3 @@
+# Document not found (404)
+
+This URL is invalid, sorry. Try the search instead!

book-example/src/README.md

@@ -8,9 +8,9 @@ What you are reading serves as an example of the output of mdBook and at the
 same time as a high-level documentation.
 
 mdBook is free and open source, you can find the source code on
-[GitHub](https://github.com/rust-lang-nursery/mdBook). Issues and feature
+[GitHub](https://github.com/rust-lang/mdBook). Issues and feature
 requests can be posted on the [GitHub issue
-tracker](https://github.com/rust-lang-nursery/mdBook/issues).
+tracker](https://github.com/rust-lang/mdBook/issues).
 
 ## API docs
 

book-example/src/SUMMARY.md

@@ -10,6 +10,7 @@
     - [clean](cli/clean.md)
 - [Format](format/README.md)
     - [SUMMARY.md](format/summary.md)
+        - [Draft chapter]()
     - [Configuration](format/config.md)
     - [Theme](format/theme/README.md)
         - [index.hbs](format/theme/index-hbs.md)
@@ -20,7 +21,7 @@
 - [Continuous Integration](continuous-integration.md)
 - [For Developers](for_developers/README.md)
     - [Preprocessors](for_developers/preprocessors.md)
-    - [Alternate Backends](for_developers/backends.md)
+    - [Alternative Backends](for_developers/backends.md)
 
 -----------
 

book-example/src/cli/README.md

@@ -7,7 +7,7 @@ capabilities first.
 ## Install From Binaries
 
 Precompiled binaries are provided for major platforms on a best-effort basis.
-Visit [the releases page](https://github.com/rust-lang-nursery/mdBook/releases)
+Visit [the releases page](https://github.com/rust-lang/mdBook/releases)
 to download the appropriate version for your platform.
 
 ## Install From Source
@@ -18,7 +18,7 @@ mdBook can also be installed from source
 
 mdBook is written in **[Rust](https://www.rust-lang.org/)** and therefore needs
 to be compiled with **Cargo**. If you haven't already installed Rust, please go
-ahead and [install it](https://www.rust-lang.org/downloads.html) now.
+ahead and [install it](https://www.rust-lang.org/tools/install) now.
 
 ### Install Crates.io version
 
@@ -39,14 +39,14 @@ have installed mdBook!
 
 ### Install Git version
 
-The **[git version](https://github.com/rust-lang-nursery/mdBook)** contains all
+The **[git version](https://github.com/rust-lang/mdBook)** contains all
 the latest bug-fixes and features, that will be released in the next version on
 **Crates.io**, if you can't wait until the next release. You can build the git
 version yourself. Open your terminal and navigate to the directory of you
 choice. We need to clone the git repository and then build it with Cargo.
 
 ```bash
-git clone --depth=1 https://github.com/rust-lang-nursery/mdBook.git
+git clone --depth=1 https://github.com/rust-lang/mdBook.git
 cd mdBook
 cargo build --release
 ```

book-example/src/cli/build.md

@@ -29,10 +29,11 @@ your default web browser after building it.
 #### --dest-dir
 
 The `--dest-dir` (`-d`) option allows you to change the output directory for the
-book. If not specified it will default to the value of the `build.build-dir` key
-in `book.toml`, or to `./book` relative to the book's root directory.
+book. Relative paths are interpreted relative to the book's root directory. If
+not specified it will default to the value of the `build.build-dir` key in
+`book.toml`, or to `./book`.
 
 -------------------
 
-***Note:*** *Make sure to run the build command in the root directory and not in
-the source directory*
+***Note:*** *The build command copies all files (excluding files with `.md` extension) from the source directory
+into the build directory.*

book-example/src/cli/clean.md

@@ -19,9 +19,9 @@ mdbook clean path/to/book
 #### --dest-dir
 
 The `--dest-dir` (`-d`) option allows you to override the book's output
-directory, which will be deleted by this command. If not specified it will
-default to the value of the `build.build-dir` key in `book.toml`, or to `./book`
-relative to the book's root directory.
+directory, which will be deleted by this command. Relative paths are interpreted
+relative to the book's root directory. If not specified it will default to the
+value of the `build.build-dir` key in `book.toml`, or to `./book`.
 
 ```bash
 mdbook clean --dest-dir=path/to/book

book-example/src/cli/init.md

@@ -19,7 +19,7 @@ book-test/
     └── SUMMARY.md
 ```
 
-- The `src` directory is were you write your book in markdown. It contains all
+- The `src` directory is where you write your book in markdown. It contains all
   the source files, configuration files, etc.
 
 - The `book` directory is where your book is rendered. All the output is ready

book-example/src/cli/serve.md

@@ -5,6 +5,9 @@ The serve command is used to preview a book by serving it over HTTP at
 changes, rebuilding the book and refreshing clients for each change. A websocket
 connection is used to trigger the client-side refresh.
 
+***Note:*** *The `serve` command is for testing a book's HTML output, and is not
+intended to be a complete HTTP server for a website.*
+
 #### Specify a directory
 
 The `serve` command can take a directory as an argument to use as the book's
@@ -34,16 +37,23 @@ configured.
 
 #### --open
 
-When you use the `--open` (`-o`) flag, mdbook will open the book in your your
+When you use the `--open` (`-o`) flag, mdbook will open the book in your
 default web browser after starting the server.
 
 #### --dest-dir
 
 The `--dest-dir` (`-d`) option allows you to change the output directory for the
-book. If not specified it will default to the value of the `build.build-dir` key
-in `book.toml`, or to `./book` relative to the book's root directory.
+book. Relative paths are interpreted relative to the book's root directory. If
+not specified it will default to the value of the `build.build-dir` key in
+`book.toml`, or to `./book`.
 
------
+#### Specify exclude patterns
 
-***Note:*** *The `serve` command is for testing, and is not intended to be a
-complete HTTP server for a website.*
+The `serve` command will not automatically trigger a build for files listed in
+the `.gitignore` file in the book root directory. The `.gitignore` file may
+contain file patterns described in the [gitignore
+documentation](https://git-scm.com/docs/gitignore). This can be useful for
+ignoring temporary files created by some editors.
+
+_Note: Only `.gitignore` from book root directory is used. Global
+`$HOME/.gitignore` or `.gitignore` files in parent directories are not used._

book-example/src/cli/test.md

@@ -48,5 +48,6 @@ comma-delimited list (`-L foo,bar`).
 #### --dest-dir
 
 The `--dest-dir` (`-d`) option allows you to change the output directory for the
-book. If not specified it will default to the value of the `build.build-dir` key
-in `book.toml`, or to `./book` relative to the book's root directory.
+book. Relative paths are interpreted relative to the book's root directory. If
+not specified it will default to the value of the `build.build-dir` key in
+`book.toml`, or to `./book`.

book-example/src/cli/watch.md

@@ -22,5 +22,18 @@ your default web browser.
 #### --dest-dir
 
 The `--dest-dir` (`-d`) option allows you to change the output directory for the
-book. If not specified it will default to the value of the `build.build-dir` key
-in `book.toml`, or to `./book` relative to the book's root directory.
+book. Relative paths are interpreted relative to the book's root directory. If
+not specified it will default to the value of the `build.build-dir` key in
+`book.toml`, or to `./book`.
+
+
+#### Specify exclude patterns
+
+The `watch` command will not automatically trigger a build for files listed in
+the `.gitignore` file in the book root directory. The `.gitignore` file may
+contain file patterns described in the [gitignore
+documentation](https://git-scm.com/docs/gitignore). This can be useful for
+ignoring temporary files created by some editors.
+
+_Note: Only `.gitignore` from book root directory is used. Global
+`$HOME/.gitignore` or `.gitignore` files in parent directories are not used._

book-example/src/continuous-integration.md

@@ -22,7 +22,7 @@ rust:
 
 before_script:
   - (test -x $HOME/.cargo/bin/cargo-install-update || cargo install cargo-update)
-  - (test -x $HOME/.cargo/bin/mdbook || cargo install --vers "^0.1" mdbook)
+  - (test -x $HOME/.cargo/bin/mdbook || cargo install --vers "^0.3" mdbook)
   - cargo install-update -a
 
 script:
@@ -54,3 +54,36 @@ deploy:
 ```
 
 That's it!
+
+### Deploying to GitHub Pages manually
+
+If your CI doesn't support GitHub pages, or you're deploying somewhere else
+with integrations such as Github Pages:
+ *note: you may want to use different tmp dirs*:
+
+```console
+$> git worktree add /tmp/book gh-pages
+$> mdbook build
+$> rm -rf /tmp/book/* # this won't delete the .git directory
+$> cp -rp book/* /tmp/book/
+$> cd /tmp/book
+$> git add -A
+$> git commit 'new book message'
+$> git push origin gh-pages
+$> cd -
+```
+
+Or put this into a Makefile rule:
+
+```makefile
+.PHONY: deploy
+deploy: book
+	@echo "====> deploying to github"
+	git worktree add /tmp/book gh-pages
+	rm -rf /tmp/book/*
+	cp -rp book/* /tmp/book/
+	cd /tmp/book && \
+		git add -A && \
+		git commit -m "deployed on $(shell date) by ${USER}" && \
+		git push origin gh-pages
+```

book-example/src/for_developers/README.md

@@ -12,14 +12,14 @@ The *For Developers* chapters are here to show you the more advanced usage of
 The two main ways a developer can hook into the book's build process is via,
 
 - [Preprocessors](preprocessors.md)
-- [Alternate Backends](backends.md)
+- [Alternative Backends](backends.md)
 
 
 ## The Build Process
 
 The process of rendering a book project goes through several steps.
 
-1. Load the book 
+1. Load the book
     - Parse the `book.toml`, falling back to the default `Config` if it doesn't
        exist
     - Load the book chapters into memory
@@ -41,6 +41,6 @@ The easiest way to find out how to use the `mdbook` crate is by looking at the
 explanation on the configuration system.
 
 
-[`MDBook`]: http://rust-lang-nursery.github.io/mdBook/mdbook/book/struct.MDBook.html
+[`MDBook`]: https://docs.rs/mdbook/*/mdbook/book/struct.MDBook.html
 [API Docs]: https://docs.rs/mdbook/*/mdbook/
-[config]: file:///home/michael/Documents/forks/mdBook/target/doc/mdbook/config/index.html
+[config]: https://docs.rs/mdbook/*/mdbook/config/index.html

book-example/src/for_developers/backends.md

@@ -1,11 +1,11 @@
-# Alternate Backends
+# Alternative Backends
 
 A "backend" is simply a program which `mdbook` will invoke during the book
 rendering process. This program is passed a JSON representation of the book and
 configuration information via `stdin`. Once the backend receives this
 information it is free to do whatever it wants.
 
-There are already several alternate backends on GitHub which can be used as a
+There are already several alternative backends on GitHub which can be used as a
 rough example of how this is accomplished in practice.
 
 - [mdbook-linkcheck] - a simple program for verifying the book doesn't contain
@@ -14,7 +14,7 @@ rough example of how this is accomplished in practice.
 - [mdbook-test] - a program to run the book's contents through [rust-skeptic] to
   verify everything compiles and runs correctly (similar to `rustdoc --test`)
 
-This page will step you through creating your own alternate backend in the form
+This page will step you through creating your own alternative backend in the form
 of a simple word counting program. Although it will be written in Rust, there's
 no reason why it couldn't be accomplished using something like Python or Ruby.
 
@@ -24,9 +24,9 @@ no reason why it couldn't be accomplished using something like Python or Ruby.
 First you'll want to create a new binary program and add `mdbook` as a
 dependency.
 
-```
+```shell
 $ cargo new --bin mdbook-wordcount
-$ cd mdbook-wordcount 
+$ cd mdbook-wordcount
 $ cargo add mdbook
 ```
 
@@ -52,8 +52,8 @@ fn main() {
 > **Note:** The `RenderContext` contains a `version` field. This lets backends
   figure out whether they are compatible with the version of `mdbook` it's being
   called by. This `version` comes directly from the corresponding field in
-  `mdbook`'s `Cargo.toml`. 
-  
+  `mdbook`'s `Cargo.toml`.
+
   It is recommended that backends use the [`semver`] crate to inspect this field
   and emit a warning if there may be a compatibility issue.
 
@@ -92,12 +92,12 @@ fn count_words(ch: &Chapter) -> usize {
 Now we've got the basics running, we want to actually use it. First, install the
 program.
 
-```
-$ cargo install
+```shell
+$ cargo install --path .
 ```
 
 Then `cd` to the particular book you'd like to count the words of and update its
-`book.toml` file. 
+`book.toml` file.
 
 ```diff
   [book]
@@ -112,7 +112,7 @@ Then `cd` to the particular book you'd like to count the words of and update its
 
 When it loads a book into memory, `mdbook` will inspect your `book.toml` file to
 try and figure out which backends to use by looking for all `output.*` tables.
-If none are provided it'll fall back to using the default HTML renderer. 
+If none are provided it'll fall back to using the default HTML renderer.
 
 Notably, this means if you want to add your own custom backend you'll also need
 to make sure to add the HTML backend, even if its table just stays empty.
@@ -120,7 +120,7 @@ to make sure to add the HTML backend, even if its table just stays empty.
 Now you just need to build your book like normal, and everything should *Just
 Work*.
 
-```
+```shell
 $ mdbook build
 ...
 2018-01-16 07:31:15 [INFO] (mdbook::renderer): Invoking the "mdbook-wordcount" renderer
@@ -140,7 +140,7 @@ Syntax highlighting: 314
 MathJax Support: 153
 Rust code specific features: 148
 For Developers: 788
-Alternate Backends: 710
+Alternative Backends: 710
 Contributors: 85
 ```
 
@@ -169,7 +169,7 @@ arguments or be an interpreted script), you can use the `command` field.
 Now imagine you don't want to count the number of words on a particular chapter
 (it might be generated text/code, etc). The canonical way to do this is via the
 usual `book.toml` configuration file by adding items to your `[output.foo]`
-table. 
+table.
 
 The `Config` can be treated roughly as a nested hashmap which lets you call
 methods like `get()` to access the config's contents, with a
@@ -211,13 +211,13 @@ and then add a check to make sure we skip ignored chapters.
 +     let cfg: WordcountConfig = ctx.config
 +         .get_deserialized("output.wordcount")
 +         .unwrap_or_default();
-  
+
       for item in ctx.book.iter() {
           if let BookItem::Chapter(ref ch) = *item {
 +             if cfg.ignores.contains(&ch.name) {
 +                 continue;
 +             }
-+ 
++
               let num_words = count_words(ch);
               println!("{}: {}", ch.name, num_words);
           }
@@ -239,17 +239,17 @@ in [`RenderContext`].
 - use std::io;
   use mdbook::renderer::RenderContext;
   use mdbook::book::{BookItem, Chapter};
-  
+
   fn main() {
     ...
-  
+
 +     let _ = fs::create_dir_all(&ctx.destination);
 +     let mut f = File::create(ctx.destination.join("wordcounts.txt")).unwrap();
-+ 
++
       for item in ctx.book.iter() {
           if let BookItem::Chapter(ref ch) = *item {
               ...
-  
+
               let num_words = count_words(ch);
               println!("{}: {}", ch.name, num_words);
 +             writeln!(f, "{}: {}", ch.name, num_words).unwrap();
@@ -261,6 +261,10 @@ in [`RenderContext`].
 > **Note:** There is no guarantee that the destination directory exists or is
 > empty (`mdbook` may leave the previous contents to let backends do caching),
 > so it's always a good idea to create it with `fs::create_dir_all()`.
+>
+> If the destination directory already exists, don't assume it will be empty.
+> To allow backends to cache the results from previous runs, `mdbook` may leave
+> old content in the directory.
 
 There's always the possibility that an error will occur while processing a book
 (just look at all the `unwrap()`'s we've written already), so `mdbook` will
@@ -276,11 +280,11 @@ like this:
 
   fn main() {
       ...
-  
+
       for item in ctx.book.iter() {
           if let BookItem::Chapter(ref ch) = *item {
               ...
-  
+
               let num_words = count_words(ch);
               println!("{}: {}", ch.name, num_words);
               writeln!(f, "{}: {}", ch.name, num_words).unwrap();
@@ -303,8 +307,8 @@ like this:
 
 Now, if we reinstall the backend and build a book,
 
-```
-$ cargo install --force
+```shell
+$ cargo install --path . --force
 $ mdbook build /path/to/book
 ...
 2018-01-16 21:21:39 [INFO] (mdbook::renderer): Invoking the "wordcount" renderer
@@ -325,11 +329,41 @@ generation or a warning).
 All environment variables are passed through to the backend, allowing you to use
 the usual `RUST_LOG` to control logging verbosity.
 
+## Handling missing backends
+
+If you enable a backend that isn't installed, the default behavior is to throw an error:
+
+```text
+The command wasn't found, is the "wordcount" backend installed?
+```
+
+This behavior can be changed by marking the backend as optional.
+
+```diff
+  [book]
+  title = "mdBook Documentation"
+  description = "Create book from markdown files. Like Gitbook but implemented in Rust"
+  authors = ["Mathieu David", "Michael-F-Bryan"]
+
+  [output.html]
+
+  [output.wordcount]
+  command = "python /path/to/wordcount.py"
++ optional = true
+```
+
+This demotes the error to a warning, and it will instead look like this:
+
+```text
+The command was not found, but was marked as optional.
+    Command: wordcount
+```
+
 
 ## Wrapping Up
 
 Although contrived, hopefully this example was enough to show how you'd create
-an alternate backend for `mdbook`. If you feel it's missing something, don't
+an alternative backend for `mdbook`. If you feel it's missing something, don't
 hesitate to create an issue in the [issue tracker] so we can improve the user
 guide.
 
@@ -342,10 +376,10 @@ the source code or ask questions.
 [mdbook-epub]: https://github.com/Michael-F-Bryan/mdbook-epub
 [mdbook-test]: https://github.com/Michael-F-Bryan/mdbook-test
 [rust-skeptic]: https://github.com/budziq/rust-skeptic
-[`RenderContext`]: http://rust-lang-nursery.github.io/mdBook/mdbook/renderer/struct.RenderContext.html
-[`RenderContext::from_json()`]: http://rust-lang-nursery.github.io/mdBook/mdbook/renderer/struct.RenderContext.html#method.from_json
+[`RenderContext`]: https://docs.rs/mdbook/*/mdbook/renderer/struct.RenderContext.html
+[`RenderContext::from_json()`]: https://docs.rs/mdbook/*/mdbook/renderer/struct.RenderContext.html#method.from_json
 [`semver`]: https://crates.io/crates/semver
-[`Book`]: http://rust-lang-nursery.github.io/mdBook/mdbook/book/struct.Book.html
-[`Book::iter()`]: http://rust-lang-nursery.github.io/mdBook/mdbook/book/struct.Book.html#method.iter
-[`Config`]: http://rust-lang-nursery.github.io/mdBook/mdbook/config/struct.Config.html
-[issue tracker]: https://github.com/rust-lang-nursery/mdBook/issues
+[`Book`]: https://docs.rs/mdbook/*/mdbook/book/struct.Book.html
+[`Book::iter()`]: https://docs.rs/mdbook/*/mdbook/book/struct.Book.html#method.iter
+[`Config`]: https://docs.rs/mdbook/*/mdbook/config/struct.Config.html
+[issue tracker]: https://github.com/rust-lang/mdBook/issues

book-example/src/for_developers/preprocessors.md

@@ -109,7 +109,7 @@ For everything else, have a look [at the complete example][example].
 [preprocessor-docs]: https://docs.rs/mdbook/latest/mdbook/preprocess/trait.Preprocessor.html
 [pc]: https://crates.io/crates/pulldown-cmark
 [pctc]: https://crates.io/crates/pulldown-cmark-to-cmark
-[example]: https://github.com/rust-lang-nursery/mdBook/blob/master/examples/de-emphasize.rs
-[an example no-op preprocessor]: https://github.com/rust-lang-nursery/mdBook/blob/master/examples/nop-preprocessor.rs
+[example]: https://github.com/rust-lang/mdBook/blob/master/examples/nop-preprocessor.rs
+[an example no-op preprocessor]: https://github.com/rust-lang/mdBook/blob/master/examples/nop-preprocessor.rs
 [`CmdPreprocessor::parse_input()`]: https://docs.rs/mdbook/latest/mdbook/preprocess/trait.Preprocessor.html#method.parse_input
 [`Book::for_each_mut()`]: https://docs.rs/mdbook/latest/mdbook/book/struct.Book.html#method.for_each_mut

book-example/src/format/config.md

@@ -10,13 +10,16 @@ title = "Example book"
 author = "John Doe"
 description = "The example book covers examples."
 
+[rust]
+edition = "2018"
+
 [build]
 build-dir = "my-example-book"
 create-missing = false
 
-[preprocess.index]
+[preprocessor.index]
 
-[preprocess.links]
+[preprocessor.links]
 
 [output.html]
 additional-css = ["custom.css"]
@@ -27,7 +30,7 @@ limit-results = 15
 
 ## Supported configuration options
 
-It is important to note that **any** relative path specified in the in the
+It is important to note that **any** relative path specified in the
 configuration will always be taken relative from the root of the book where the
 configuration file is located.
 
@@ -42,6 +45,7 @@ This is general information about your book.
 - **src:** By default, the source directory is found in the directory named
   `src` directly under the root folder. But this is configurable with the `src`
   key in the configuration file.
+- **language:** The main language of the book, which is used as a language attribute `<html lang="en">` for example.
 
 **book.toml**
 ```toml
@@ -50,8 +54,25 @@ title = "Example book"
 authors = ["John Doe", "Jane Doe"]
 description = "The example book covers examples."
 src = "my-src"  # the source files will be found in `root/my-src` instead of `root/src`
+language = "en"
 ```
 
+### Rust options
+
+Options for the Rust language, relevant to running tests and playground
+integration.
+
+- **edition**: Rust edition to use by default for the code snippets. Default
+  is "2015". Individual code blocks can be controlled with the `edition2015`
+  or `edition2018` annotations, such as:
+
+  ~~~text
+  ```rust,edition2015
+  // This only works in 2015.
+  let try = true;
+  ```
+  ~~~
+
 ### Build options
 
 This controls the build process of your book.
@@ -68,18 +89,18 @@ This controls the build process of your book.
   If you have the same, and/or other preprocessors declared via their table
   of configuration, they will run instead.
 
-  - For clarity, with no preprocessor configuration, the default `links` and 
+  - For clarity, with no preprocessor configuration, the default `links` and
     `index` will run.
   - Setting `use-default-preprocessors = false` will disable these
     default preprocessors from running.
-  - Adding `[preprocessor.links]`, for example, will ensure, regardless of 
+  - Adding `[preprocessor.links]`, for example, will ensure, regardless of
     `use-default-preprocessors` that `links` it will run.
 
 ## Configuring Preprocessors
 
 The following preprocessors are available and included by default:
 
-- `links`: Expand the `{{ #playpen }}` and `{{ #include }}` handlebars
+- `links`: Expand the `{{ #playground }}`, `{{ #include }}`, and `{{ #rustdoc_include }}` handlebars
   helpers in a chapter to include the contents of a file.
 - `index`: Convert all chapter files named `README.md` into `index.md`. That is
   to say, all `README.md` would be rendered to an index file `index.html` in the
@@ -92,9 +113,9 @@ The following preprocessors are available and included by default:
 build-dir = "build"
 create-missing = false
 
-[preprocess.links]
+[preprocessor.links]
 
-[preprocess.index]
+[preprocessor.index]
 ```
 
 ### Custom Preprocessor Configuration
@@ -105,8 +126,8 @@ configuration to the preprocessor by adding key-value pairs to the table.
 
 For example
 
-```
-[preprocess.links]
+```toml
+[preprocessor.links]
 # set the renderers this preprocessor will run for
 renderers = ["html"]
 some_extra_feature = true
@@ -117,7 +138,7 @@ some_extra_feature = true
 You can explicitly specify that a preprocessor should run for a renderer by
 binding the two together.
 
-```
+```toml
 [preprocessor.mathjax]
 renderers = ["html"]  # mathjax only makes sense with the HTML renderer
 ```
@@ -125,7 +146,7 @@ renderers = ["html"]  # mathjax only makes sense with the HTML renderer
 ### Provide Your Own Command
 
 By default when you add a `[preprocessor.foo]` table to your `book.toml` file,
-`mdbook` will try to invoke the `mdbook-foo` executa`ble. If you want to use a
+`mdbook` will try to invoke the `mdbook-foo` executable. If you want to use a
 different program name or pass in command-line arguments, this behaviour can
 be overridden by adding a `command` field.
 
@@ -146,8 +167,17 @@ The following configuration options are available:
 - **theme:** mdBook comes with a default theme and all the resource files needed
   for it. But if this option is set, mdBook will selectively overwrite the theme
   files with the ones found in the specified folder.
+- **default-theme:** The theme color scheme to select by default in the
+  'Change Theme' dropdown. Defaults to `light`.
+- **preferred-dark-theme:** The default dark theme. This theme will be used if
+  the browser requests the dark version of the site via the
+  ['prefers-color-scheme'](https://developer.mozilla.org/en-US/docs/Web/CSS/@media/prefers-color-scheme)
+  CSS media query. Defaults to `navy`.
 - **curly-quotes:** Convert straight quotes to curly quotes, except for those
   that occur in code blocks and code spans. Defaults to `false`.
+- **mathjax-support:** Adds support for [MathJax](mathjax.md). Defaults to
+  `false`.
+- **copy-fonts:** Copies fonts.css and respective font files to the output directory and use them in the default theme. Defaults to `true`.
 - **google-analytics:** If you use Google Analytics, this option lets you enable
   it by simply specifying your ID in the configuration file.
 - **additional-css:** If you need to slightly change the appearance of your book
@@ -160,15 +190,41 @@ The following configuration options are available:
 - **no-section-label:** mdBook by defaults adds section label in table of
   contents column. For example, "1.", "2.1". Set this option to true to disable
   those labels. Defaults to `false`.
-- **playpen:** A subtable for configuring various playpen settings.
+- **fold:** A subtable for configuring sidebar section-folding behavior.
+- **playground:** A subtable for configuring various playground settings.
 - **search:** A subtable for configuring the in-browser search functionality.
   mdBook must be compiled with the `search` feature enabled (on by default).
+- **git-repository-url:**  A url to the git repository for the book. If provided
+  an icon link will be output in the menu bar of the book.
+- **git-repository-icon:** The FontAwesome icon class to use for the git
+  repository link. Defaults to `fa-github`.
+- **redirect:** A subtable used for generating redirects when a page is moved.
+  The table contains key-value pairs where the key is where the redirect file
+  needs to be created, as an absolute path from the build directory, (e.g.
+  `/appendices/bibliography.html`). The value can be any valid URI the
+  browser should navigate to (e.g. `https://rust-lang.org/`,
+  `/overview.html`, or `../bibliography.html`).
+- **input-404:** The name of the markdown file used for misssing files.
+  The corresponding output file will be the same, with the extension replaced with `html`.
+  Defaults to `404.md`.
+- **site-url:** The url where the book will be hosted. This is required to ensure
+  navigation links and script/css imports in the 404 file work correctly, even when accessing
+  urls in subdirectories. Defaults to `/`.
 
-Available configuration options for the `[output.html.playpen]` table:
+Available configuration options for the `[output.html.fold]` table:
+
+- **enable:** Enable section-folding. When off, all folds are open.
+  Defaults to `false`.
+- **level:** The higher the more folded regions are open. When level is 0, all
+  folds are closed. Defaults to `0`.
+
+Available configuration options for the `[output.html.playground]` table:
 
 - **editable:** Allow editing the source code. Defaults to `false`.
+- **copyable:** Display the copy button on code snippets. Defaults to `true`.
 - **copy-js:** Copy JavaScript files for the editor to the output directory.
   Defaults to `true`.
+- **line-numbers** Display line numbers on editable sections of code. Requires both `editable` and `copy-js` to be `true`. Defaults to `false`.
 
 [Ace]: https://ace.c9.io/
 
@@ -179,7 +235,7 @@ Available configuration options for the `[output.html.search]` table:
 - **teaser-word-count:** The number of words used for a search result teaser.
   Defaults to `30`.
 - **use-boolean-and:** Define the logical link between multiple search words. If
-  true, all search words must appear in each result. Defaults to `true`.
+  true, all search words must appear in each result. Defaults to `false`.
 - **boost-title:** Boost factor for the search result score if a search word
   appears in the header. Defaults to `2`.
 - **boost-hierarchy:** Boost factor for the search result score if a search word
@@ -203,25 +259,33 @@ title = "Example book"
 authors = ["John Doe", "Jane Doe"]
 description = "The example book covers examples."
 
-[build]
-build-dir = "book"
-create-missing = true
-preprocess = ["links", "index"]
-
 [output.html]
 theme = "my-theme"
+default-theme = "light"
+preferred-dark-theme = "navy"
 curly-quotes = true
-google-analytics = "123456"
+mathjax-support = false
+copy-fonts = true
+google-analytics = "UA-123456-7"
 additional-css = ["custom.css", "custom2.css"]
 additional-js = ["custom.js"]
+no-section-label = false
+git-repository-url = "https://github.com/rust-lang/mdBook"
+git-repository-icon = "fa-github"
+site-url = "/example-book/"
+input-404 = "not-found.md"
 
-[output.html.playpen]
-editor = "./path/to/editor"
+[output.html.fold]
+enable = false
+level = 0
+
+[output.html.playground]
 editable = false
+copy-js = true
+line-numbers = false
 
 [output.html.search]
 enable = true
-searcher = "./path/to/searcher"
 limit-results = 30
 teaser-word-count = 30
 use-boolean-and = true
@@ -231,18 +295,48 @@ boost-paragraph = 1
 expand = true
 heading-split-level = 3
 copy-js = true
+
+[output.html.redirect]
+"/appendices/bibliography.html" = "https://rustc-dev-guide.rust-lang.org/appendix/bibliography.html"
+"/other-installation-methods.html" = "../infra/other-installation-methods.html"
 ```
 
+### Markdown Renderer
+
+The Markdown renderer will run preprocessors and then output the resulting
+Markdown. This is mostly useful for debugging preprocessors, especially in
+conjunction with `mdbook test` to see the Markdown that `mdbook` is passing
+to `rustdoc`.
+
+The Markdown renderer is included with `mdbook` but disabled by default.
+Enable it by adding an empty table to your `book.toml` as follows:
+
+```toml
+[output.markdown]
+```
+
+There are no configuration options for the Markdown renderer at this time;
+only whether it is enabled or disabled.
+
+See [the preprocessors documentation](#configuring-preprocessors) for how to
+specify which preprocessors should run before the Markdown renderer.
+
 ### Custom Renderers
 
-A custom renderer can be enabled by adding a `[output.foo]` table to your 
-`book.toml`. Similar to [preprocessors](#configuring-preprocessors) this will 
-instruct `mdbook` to pass a representation of the book to `mdbook-foo` for 
-rendering.
+A custom renderer can be enabled by adding a `[output.foo]` table to your
+`book.toml`. Similar to [preprocessors](#configuring-preprocessors) this will
+instruct `mdbook` to pass a representation of the book to `mdbook-foo` for
+rendering. See the [alternative backends] chapter for more detail.
 
-Custom renderers will have access to all configuration within their table
-(i.e. anything under `[output.foo]`), and the command to be invoked can be 
-manually specified with the `command` field.
+The custom renderer has access to all the fields within its table (i.e.
+anything under `[output.foo]`). mdBook checks for two common fields:
+
+- **command:** The command to execute for this custom renderer. Defaults to
+  the name of the renderer with the `mdbook-` prefix (such as `mdbook-foo`).
+- **optional:** If `true`, then the command will be ignored if it is not
+  installed, otherwise mdBook will fail with an error. Defaults to `false`.
+
+[alternative backends]: ../for_developers/backends.md
 
 ## Environment Variables
 
@@ -274,11 +368,11 @@ book's title without needing to touch your `book.toml`.
 > This means, if you so desired, you could override all book metadata when
 > building the book with something like
 >
-> ```text
+> ```shell
 > $ export MDBOOK_BOOK="{'title': 'My Awesome Book', authors: ['Michael-F-Bryan']}"
 > $ mdbook build
 > ```
 
 The latter case may be useful in situations where `mdbook` is invoked from a
 script or CI, where it sometimes isn't possible to update the `book.toml` before
-building.
+building.

book-example/src/format/mdbook.md

@@ -3,7 +3,9 @@
 ## Hiding code lines
 
 There is a feature in mdBook that lets you hide code lines by prepending them
-with a `#`.
+with a `#` [in the same way that Rustdoc does][rustdoc-hide].
+
+[rustdoc-hide]: https://doc.rust-lang.org/stable/rustdoc/documentation-tests.html#hiding-portions-of-the-example
 
 ```bash
 # fn main() {
@@ -35,10 +37,20 @@ With the following syntax, you can include files into your book:
 
 The path to the file has to be relative from the current source file.
 
-Usually, this command is used for including code snippets and examples. In this
-case, oftens one would include a specific part of the file e.g. which only
-contains the relevant lines for the example. We support four different modes of
-partial includes:
+mdBook will interpret included files as markdown. Since the include command
+is usually used for inserting code snippets and examples, you will often
+wrap the command with ```` ``` ```` to display the file contents without
+interpretting them.
+
+````hbs
+```
+\{{#include file.rs}}
+```
+````
+
+## Including portions of a file
+Often you only need a specific part of the file e.g. relevant lines for an
+example. We support four different modes of partial includes:
 
 ```hbs
 \{{#include file.rs:2}}
@@ -53,22 +65,130 @@ the file are omitted. The third command includes all lines from line 2, i.e. the
 first line is omitted. The last command includes the excerpt of `file.rs`
 consisting of lines 2 to 10.
 
+To avoid breaking your book when modifying included files, you can also
+include a specific section using anchors instead of line numbers.
+An anchor is a pair of matching lines. The line beginning an anchor must
+match the regex "ANCHOR:\s*[\w_-]+" and similarly the ending line must match
+the regex "ANCHOR_END:\s*[\w_-]+". This allows you to put anchors in
+any kind of commented line.
+
+Consider the following file to include:
+```rs
+/* ANCHOR: all */
+
+// ANCHOR: component
+struct Paddle {
+    hello: f32,
+}
+// ANCHOR_END: component
+
+////////// ANCHOR: system
+impl System for MySystem { ... }
+////////// ANCHOR_END: system
+
+/* ANCHOR_END: all */
+```
+
+Then in the book, all you have to do is:
+````hbs
+Here is a component:
+```rust,no_run,noplayground
+\{{#include file.rs:component}}
+```
+
+Here is a system:
+```rust,no_run,noplayground
+\{{#include file.rs:system}}
+```
+
+This is the full file.
+```rust,no_run,noplayground
+\{{#include file.rs:all}}
+```
+````
+
+Lines containing anchor patterns inside the included anchor are ignored.
+
+## Including a file but initially hiding all except specified lines
+
+The `rustdoc_include` helper is for including code from external Rust files that contain complete
+examples, but only initially showing particular lines specified with line numbers or anchors in the
+same way as with `include`.
+
+The lines not in the line number range or between the anchors will still be included, but they will
+be prefaced with `#`. This way, a reader can expand the snippet to see the complete example, and
+Rustdoc will use the complete example when you run `mdbook test`.
+
+For example, consider a file named `file.rs` that contains this Rust program:
+
+```rust
+fn main() {
+    let x = add_one(2);
+    assert_eq!(x, 3);
+}
+
+fn add_one(num: i32) -> i32 {
+    num + 1
+}
+```
+
+We can include a snippet that initially shows only line 2 by using this syntax:
+
+````hbs
+To call the `add_one` function, we pass it an `i32` and bind the returned value to `x`:
+
+```rust
+\{{#rustdoc_include file.rs:2}}
+```
+````
+
+This would have the same effect as if we had manually inserted the code and hidden all but line 2
+using `#`:
+
+````hbs
+To call the `add_one` function, we pass it an `i32` and bind the returned value to `x`:
+
+```rust
+# fn main() {
+    let x = add_one(2);
+#     assert_eq!(x, 3);
+# }
+#
+# fn add_one(num: i32) -> i32 {
+#     num + 1
+#}
+```
+````
+
+That is, it looks like this (click the "expand" icon to see the rest of the file):
+
+```rust
+# fn main() {
+    let x = add_one(2);
+#     assert_eq!(x, 3);
+# }
+#
+# fn add_one(num: i32) -> i32 {
+#     num + 1
+#}
+```
+
 ## Inserting runnable Rust files
 
 With the following syntax, you can insert runnable Rust files into your book:
 
 ```hbs
-\{{#playpen file.rs}}
+\{{#playground file.rs}}
 ```
 
 The path to the Rust file has to be relative from the current source file.
 
-When play is clicked, the code snippet will be sent to the [Rust Playpen] to be
+When play is clicked, the code snippet will be sent to the [Rust Playground] to be
 compiled and run. The result is sent back and displayed directly underneath the
 code.
 
 Here is what a rendered code snippet looks like:
 
-{{#playpen example.rs}}
+{{#playground example.rs}}
 
-[Rust Playpen]: https://play.rust-lang.org/
+[Rust Playground]: https://play.rust-lang.org/

book-example/src/format/summary.md

@@ -7,7 +7,7 @@ are. Without this file, there is no book.
 Even though `SUMMARY.md` is a markdown file, the formatting is very strict to
 allow for easy parsing. Let's see how you should format your `SUMMARY.md` file.
 
-#### Allowed elements
+#### Structure
 
 1. ***Title*** It's common practice to begin with a title, generally <code
    class="language-markdown"># Summary</code>. But it is not mandatory, the
@@ -22,17 +22,45 @@ allow for easy parsing. Let's see how you should format your `SUMMARY.md` file.
    [Title of prefix element](relative/path/to/markdown.md)
    ```
 
-3. ***Numbered Chapter*** Numbered chapters are the main content of the book,
+3. ***Part Title:*** Headers can be used as a title for the following numbered
+   chapters. This can be used to logically separate different sections
+   of book. The title is rendered as unclickable text.
+   Titles are optional, and the numbered chapters can be broken into as many
+   parts as desired.
+
+4. ***Numbered Chapter*** Numbered chapters are the main content of the book,
    they will be numbered and can be nested, resulting in a nice hierarchy
    (chapters, sub-chapters, etc.)
    ```markdown
+   # Title of Part
+
    - [Title of the Chapter](relative/path/to/markdown.md)
+
+   # Title of Another Part
+
+   - [More Chapters](relative/path/to/markdown2.md)
    ```
    You can either use `-` or `*` to indicate a numbered chapter.
 
-4. ***Suffix Chapter*** After the numbered chapters you can add a couple of
+5. ***Suffix Chapter*** After the numbered chapters you can add a couple of
    non-numbered chapters. They are the same as prefix chapters but come after
    the numbered chapters instead of before.
 
 All other elements are unsupported and will be ignored at best or result in an
 error.
+
+#### Other elements
+
+- ***Separators*** In between chapters you can add a separator. In the HTML renderer
+  this will result in a line being rendered in the table of contents. A separator is
+  a line containing exclusively dashes and at least three of them: `---`.
+- ***Draft chapters*** Draft chapters are chapters without a file and thus content.
+  The purpose of a draft chapter is to signal future chapters still to be written.
+  Or when still laying out the structure of the book to avoid creating the files
+  while you are still changing the structure of the book a lot.
+  Draft chapters will be rendered in the HTML renderer as disabled links in the table
+  of contents, as you can see for the next chapter in the table of contents on the left.
+  Draft chapters are written like normal chapters but without writing the path to the file
+  ```markdown
+  - [Draft chapter]()
+  ```

book-example/src/format/theme/README.md

@@ -11,16 +11,19 @@ and now that file will be used instead of the default file.
 
 Here are the files you can override:
 
-- ***index.hbs*** is the handlebars template.
-- ***book.css*** is the style used in the output. If you want to change the
+- **_index.hbs_** is the handlebars template.
+- **_head.hbs_** is appended to the HTML `<head>` section.
+- **_header.hbs_** content is appended on top of every book page.
+- **_book.css_** is the style used in the output. If you want to change the
   design of your book, this is probably the file you want to modify. Sometimes
   in conjunction with `index.hbs` when you want to radically change the layout.
-- ***book.js*** is mostly used to add client side functionality, like hiding /
+- **_book.js_** is mostly used to add client side functionality, like hiding /
   un-hiding the sidebar, changing the theme, ...
-- ***highlight.js*** is the JavaScript that is used to highlight code snippets,
-  you should not need to modify this.  
-- ***highlight.css*** is the theme used for the code highlighting
-- ***favicon.png*** the favicon that will be used
+- **_highlight.js_** is the JavaScript that is used to highlight code snippets,
+  you should not need to modify this.
+- **_highlight.css_** is the theme used for the code highlighting.
+- **_favicon.svg_** and **_favicon.png_** the favicon that will be used. The SVG
+  version is used by [newer browsers].
 
 Generally, when you want to tweak the theme, you don't need to override all the
 files. If you only need changes in the stylesheet, there is no point in
@@ -32,3 +35,10 @@ functionality. Therefore I recommend to use the file from the default theme as
 template and only add / modify what you need. You can copy the default theme
 into your source directory automatically by using `mdbook init --theme` just
 remove the files you don't want to override.
+
+If you completely replace all built-in themes, be sure to also set
+[`output.html.preferred-dark-theme`] in the config, which defaults to the
+built-in `navy` theme.
+
+[`output.html.preferred-dark-theme`]: ../config.md#html-renderer-options
+[newer browsers]: https://caniuse.com/#feat=link-icon-svg

book-example/src/format/theme/editor.md

@@ -1,11 +1,11 @@
 # Editor
 
-In addition to providing runnable code playpens, mdBook optionally allows them
+In addition to providing runnable code playgrounds, mdBook optionally allows them
 to be editable. In order to enable editable code blocks, the following needs to
 be added to the ***book.toml***:
 
 ```toml
-[output.html.playpen]
+[output.html.playground]
 editable = true
 ```
 
@@ -19,7 +19,7 @@ fn main() {
 }
 ```</code></pre>
 
-The above will result in this editable playpen:
+The above will result in this editable playground:
 
 ```rust,editable
 fn main() {
@@ -28,7 +28,7 @@ fn main() {
 }
 ```
 
-Note the new `Undo Changes` button in the editable playpens.
+Note the new `Undo Changes` button in the editable playgrounds.
 
 ## Customizing the Editor
 
@@ -36,7 +36,7 @@ By default, the editor is the [Ace](https://ace.c9.io/) editor, but, if desired,
 the functionality may be overriden by providing a different folder:
 
 ```toml
-[output.html.playpen]
+[output.html.playground]
 editable = true
 editor = "/path/to/editor"
 ```

book-example/src/format/theme/index-hbs.md

@@ -17,9 +17,8 @@ handlebars template you can access this information by using
 
 Here is a list of the properties that are exposed:
 
-- ***language*** Language of the book in the form `en`. To use in <code
-  class="language-html">\<html lang="{{ language }}"></code> for example. At the
-  moment it is hardcoded.
+- ***language*** Language of the book in the form `en`, as specified in `book.toml` (if not specified, defaults to `en`). To use in <code
+  class="language-html">\<html lang="{{ language }}"></code> for example.
 - ***title*** Title of the book, as specified in `book.toml`
 - ***chapter_title*** Title of the current chapter, as listed in `SUMMARY.md`
 
@@ -45,53 +44,57 @@ at your disposal.
 
 ### 1. toc
 
-    The toc helper is used like this
+The toc helper is used like this
 
-    ```handlebars
-    {{#toc}}{{/toc}}
-    ```
+```handlebars
+{{#toc}}{{/toc}}
+```
 
-    and outputs something that looks like this, depending on the structure of your book
+and outputs something that looks like this, depending on the structure of your
+book
 
-    ```html
-    <ul class="chapter">
-        <li><a href="link/to/file.html">Some chapter</a></li>
-        <li>
-            <ul class="section">
-                <li><a href="link/to/other_file.html">Some other Chapter</a></li>
-            </ul>
-        </li>
-    </ul>
-    ```
+```html
+<ul class="chapter">
+    <li><a href="link/to/file.html">Some chapter</a></li>
+    <li>
+        <ul class="section">
+            <li><a href="link/to/other_file.html">Some other Chapter</a></li>
+        </ul>
+    </li>
+</ul>
+```
 
-    If you would like to make a toc with another structure, you have access to the chapters property containing all the data.
-    The only limitation at the moment is that you would have to do it with JavaScript instead of with a handlebars helper.
+If you would like to make a toc with another structure, you have access to the
+chapters property containing all the data. The only limitation at the moment
+is that you would have to do it with JavaScript instead of with a handlebars
+helper.
 
-    ```html
-    <script>
-    var chapters = {{chapters}};
-    // Processing here
-    </script>
-    ```
+```html
+<script>
+var chapters = {{chapters}};
+// Processing here
+</script>
+```
 
 ### 2. previous / next
 
-    The previous and next helpers expose a `link` and `name` property to the previous and next chapters.
+The previous and next helpers expose a `link` and `name` property to the
+previous and next chapters.
 
-    They are used like this
+They are used like this
 
-    ```handlebars
-    {{#previous}}
-        <a href="{{link}}" class="nav-chapters previous">
-            <i class="fa fa-angle-left"></i>
-        </a>
-    {{/previous}}
-    ```
+```handlebars
+{{#previous}}
+    <a href="{{link}}" class="nav-chapters previous">
+        <i class="fa fa-angle-left"></i>
+    </a>
+{{/previous}}
+```
 
-    The inner html will only be rendered if the previous / next chapter exists.
-    Of course the inner html can be changed to your liking.
+The inner html will only be rendered if the previous / next chapter exists.
+Of course the inner html can be changed to your liking.
 
 ------
 
 *If you would like other properties or helpers exposed, please [create a new
-issue](https://github.com/rust-lang-nursery/mdBook/issues)*
+issue](https://github.com/rust-lang/mdBook/issues)*

book-example/src/format/theme/syntax-highlighting.md

@@ -22,7 +22,7 @@ overridden with your own.
 
 If you want to use another theme for `highlight.js` download it from their
 website, or make it yourself, rename it to `highlight.css` and put it in
-`src/theme` (or the equivalent if you changed your source folder)
+the `theme` folder of your book.
 
 Now your theme will be used instead of the default theme.
 
@@ -62,7 +62,7 @@ everyone can benefit from it.**
 
 If you think the default theme doesn't look quite right for a specific language,
 or could be improved. Feel free to [submit a new
-issue](https://github.com/rust-lang-nursery/mdBook/issues) explaining what you
+issue](https://github.com/rust-lang/mdBook/issues) explaining what you
 have in mind and I will take a look at it.
 
 You could also create a pull-request with the proposed improvements.

ci/before_deploy.sh

@@ -1,32 +0,0 @@
-# This script takes care of building your crate and packaging it for release
-
-set -ex
-
-main() {
-    local src=$(pwd) \
-          stage=
-
-    case $TRAVIS_OS_NAME in
-        linux)
-            stage=$(mktemp -d)
-            ;;
-        osx)
-            stage=$(mktemp -d -t tmp)
-            ;;
-    esac
-
-    # This will slow down the build, but is necessary to not run out of disk space
-    cargo clean
-
-    cargo rustc --bin mdbook --target $TARGET --release -- -C lto
-
-    cp target/$TARGET/release/mdbook $stage/
-
-    cd $stage
-    tar czf $src/$CRATE_NAME-$TRAVIS_TAG-$TARGET.tar.gz *
-    cd $src
-
-    rm -rf $stage
-}
-
-main

ci/install-hub.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+# Installs the `hub` executable into hub/bin
+set -ex
+case $1 in
+  ubuntu*)
+    curl -LsSf https://github.com/github/hub/releases/download/v2.12.8/hub-linux-amd64-2.12.8.tgz -o hub.tgz
+    mkdir hub
+    tar -xzvf hub.tgz --strip=1 -C hub
+    ;;
+  macos*)
+    curl -LsSf https://github.com/github/hub/releases/download/v2.12.8/hub-darwin-amd64-2.12.8.tgz -o hub.tgz
+    mkdir hub
+    tar -xzvf hub.tgz --strip=1 -C hub
+    ;;
+  windows*)
+    curl -LsSf https://github.com/github/hub/releases/download/v2.12.8/hub-windows-amd64-2.12.8.zip -o hub.zip
+    7z x hub.zip -ohub
+    ;;
+  *)
+    echo "OS should be first parameter, was: $1"
+    ;;
+esac
+
+echo "##[add-path]$PWD/hub/bin"

ci/install-rust.sh

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+# Install/update rust.
+# The first argument should be the toolchain to install.
+
+set -ex
+if [ -z "$1" ]
+then
+    echo "First parameter must be toolchain to install."
+    exit 1
+fi
+TOOLCHAIN="$1"
+
+rustup set profile minimal
+rustup component remove --toolchain=$TOOLCHAIN rust-docs || echo "already removed"
+rustup update $TOOLCHAIN
+rustup default $TOOLCHAIN
+rustup -V
+rustc -Vv
+cargo -V

ci/make-release.sh

@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+# Builds the release and creates an archive and optionally deploys to GitHub.
+set -ex
+
+if [[ -z "$GITHUB_REF" ]]
+then
+  echo "GITHUB_REF must be set"
+  exit 1
+fi
+# Strip mdbook-refs/tags/ from the start of the ref.
+TAG=${GITHUB_REF#*/tags/}
+
+host=$(rustc -Vv | grep ^host: | sed -e "s/host: //g")
+cargo rustc --bin mdbook --release -- -C lto
+cd target/release
+case $1 in
+  ubuntu* | macos*)
+    asset="mdbook-$TAG-$host.tar.gz"
+    tar czf ../../$asset mdbook
+    ;;
+  windows*)
+    asset="mdbook-$TAG-$host.zip"
+    7z a ../../$asset mdbook.exe
+    ;;
+  *)
+    echo "OS should be first parameter, was: $1"
+    ;;
+esac
+cd ../..
+
+if [[ -z "$GITHUB_TOKEN" ]]
+then
+  echo "$GITHUB_TOKEN not set, skipping deploy."
+else
+  hub release edit -m "" --attach $asset $TAG
+fi

examples/de-emphasize.rs

@@ -1,82 +0,0 @@
-//! An example preprocessor for removing all forms of emphasis from a markdown
-//! book.
-
-extern crate mdbook;
-extern crate pulldown_cmark;
-extern crate pulldown_cmark_to_cmark;
-
-use mdbook::book::{Book, BookItem, Chapter};
-use mdbook::errors::{Error, Result};
-use mdbook::preprocess::{Preprocessor, PreprocessorContext};
-use pulldown_cmark::{Event, Parser, Tag};
-use pulldown_cmark_to_cmark::fmt::cmark;
-
-const NAME: &str = "md-links-to-html-links";
-
-fn main() {
-    panic!("This example is intended to be part of a library");
-}
-
-struct Deemphasize;
-
-impl Preprocessor for Deemphasize {
-    fn name(&self) -> &str {
-        NAME
-    }
-
-    fn run(&self, _ctx: &PreprocessorContext, mut book: Book) -> Result<Book> {
-        eprintln!("Running '{}' preprocessor", self.name());
-        let mut num_removed_items = 0;
-
-        process(&mut book.sections, &mut num_removed_items)?;
-
-        eprintln!(
-            "{}: removed {} events from markdown stream.",
-            self.name(),
-            num_removed_items
-        );
-
-        Ok(book)
-    }
-}
-
-fn process<'a, I>(items: I, num_removed_items: &mut usize) -> Result<()>
-where
-    I: IntoIterator<Item = &'a mut BookItem> + 'a,
-{
-    for item in items {
-        if let BookItem::Chapter(ref mut chapter) = *item {
-            eprintln!("{}: processing chapter '{}'", NAME, chapter.name);
-
-            let md = remove_emphasis(num_removed_items, chapter)?;
-            chapter.content = md;
-        }
-    }
-
-    Ok(())
-}
-
-fn remove_emphasis(
-    num_removed_items: &mut usize,
-    chapter: &mut Chapter,
-) -> Result<String> {
-    let mut buf = String::with_capacity(chapter.content.len());
-
-    let events = Parser::new(&chapter.content).filter(|e| {
-        let should_keep = match *e {
-            Event::Start(Tag::Emphasis)
-            | Event::Start(Tag::Strong)
-            | Event::End(Tag::Emphasis)
-            | Event::End(Tag::Strong) => false,
-            _ => true,
-        };
-        if !should_keep {
-            *num_removed_items += 1;
-        }
-        should_keep
-    });
-
-    cmark(events, &mut buf, None).map(|_| buf).map_err(|err| {
-        Error::from(format!("Markdown serialization failed: {}", err))
-    })
-}

examples/nop-preprocessor.rs

@@ -1,14 +1,10 @@
-extern crate clap;
-extern crate mdbook;
-extern crate serde_json;
-
+use crate::nop_lib::Nop;
 use clap::{App, Arg, ArgMatches, SubCommand};
 use mdbook::book::Book;
 use mdbook::errors::Error;
 use mdbook::preprocess::{CmdPreprocessor, Preprocessor, PreprocessorContext};
 use std::io;
 use std::process;
-use nop_lib::Nop;
 
 pub fn make_app() -> App<'static, 'static> {
     App::new("nop-preprocessor")
@@ -16,7 +12,8 @@ pub fn make_app() -> App<'static, 'static> {
         .subcommand(
             SubCommand::with_name("supports")
                 .arg(Arg::with_name("renderer").required(true))
-                .about("Check whether a renderer is supported by this preprocessor"))
+                .about("Check whether a renderer is supported by this preprocessor"),
+        )
 }
 
 fn main() {
@@ -27,11 +24,9 @@ fn main() {
 
     if let Some(sub_args) = matches.subcommand_matches("supports") {
         handle_supports(&preprocessor, sub_args);
-    } else {
-        if let Err(e) = handle_preprocessing(&preprocessor) {
-            eprintln!("{}", e);
-            process::exit(1);
-        }
+    } else if let Err(e) = handle_preprocessing(&preprocessor) {
+        eprintln!("{}", e);
+        process::exit(1);
     }
 }
 
@@ -87,16 +82,12 @@ mod nop_lib {
             "nop-preprocessor"
         }
 
-        fn run(
-            &self,
-            ctx: &PreprocessorContext,
-            book: Book,
-        ) -> Result<Book, Error> {
+        fn run(&self, ctx: &PreprocessorContext, book: Book) -> Result<Book, Error> {
             // In testing we want to tell the preprocessor to blow up by setting a
             // particular config value
             if let Some(nop_cfg) = ctx.config.get_preprocessor(self.name()) {
                 if nop_cfg.contains_key("blow-up") {
-                    return Err("Boom!!1!".into());
+                    anyhow::bail!("Boom!!1!");
                 }
             }
 
@@ -109,4 +100,3 @@ mod nop_lib {
         }
     }
 }
-

src/book/book.rs

@@ -5,8 +5,8 @@ use std::io::{Read, Write};
 use std::path::{Path, PathBuf};
 
 use super::summary::{parse_summary, Link, SectionNumber, Summary, SummaryItem};
-use config::BuildConfig;
-use errors::*;
+use crate::config::BuildConfig;
+use crate::errors::*;
 
 /// Load a book into memory from its `src/` directory.
 pub fn load_book<P: AsRef<Path>>(src_dir: P, cfg: &BuildConfig) -> Result<Book> {
@@ -15,13 +15,13 @@ pub fn load_book<P: AsRef<Path>>(src_dir: P, cfg: &BuildConfig) -> Result<Book>
 
     let mut summary_content = String::new();
     File::open(summary_md)
-        .chain_err(|| "Couldn't open SUMMARY.md")?
+        .with_context(|| "Couldn't open SUMMARY.md")?
         .read_to_string(&mut summary_content)?;
 
-    let summary = parse_summary(&summary_content).chain_err(|| "Summary parsing failed")?;
+    let summary = parse_summary(&summary_content).with_context(|| "Summary parsing failed")?;
 
     if cfg.create_missing {
-        create_missing(&src_dir, &summary).chain_err(|| "Unable to create missing chapters")?;
+        create_missing(&src_dir, &summary).with_context(|| "Unable to create missing chapters")?;
     }
 
     load_book_from_disk(&summary, src_dir)
@@ -39,17 +39,19 @@ fn create_missing(src_dir: &Path, summary: &Summary) -> Result<()> {
         let next = items.pop().expect("already checked");
 
         if let SummaryItem::Link(ref link) = *next {
-            let filename = src_dir.join(&link.location);
-            if !filename.exists() {
-                if let Some(parent) = filename.parent() {
-                    if !parent.exists() {
-                        fs::create_dir_all(parent)?;
+            if let Some(ref location) = link.location {
+                let filename = src_dir.join(location);
+                if !filename.exists() {
+                    if let Some(parent) = filename.parent() {
+                        if !parent.exists() {
+                            fs::create_dir_all(parent)?;
+                        }
                     }
-                }
-                debug!("Creating missing file {}", filename.display());
+                    debug!("Creating missing file {}", filename.display());
 
-                let mut f = File::create(&filename)?;
-                writeln!(f, "# {}", link.name)?;
+                    let mut f = File::create(&filename)?;
+                    writeln!(f, "# {}", link.name)?;
+                }
             }
 
             items.extend(&link.nested_items);
@@ -82,7 +84,7 @@ impl Book {
     }
 
     /// Get a depth-first iterator over the items in the book.
-    pub fn iter(&self) -> BookItems {
+    pub fn iter(&self) -> BookItems<'_> {
         BookItems {
             items: self.sections.iter().collect(),
         }
@@ -116,7 +118,7 @@ where
     I: IntoIterator<Item = &'a mut BookItem>,
 {
     for item in items {
-        if let &mut BookItem::Chapter(ref mut ch) = item {
+        if let BookItem::Chapter(ch) = item {
             for_each_mut(func, &mut ch.sub_items);
         }
 
@@ -131,6 +133,8 @@ pub enum BookItem {
     Chapter(Chapter),
     /// A section separator.
     Separator,
+    /// A part title.
+    PartTitle(String),
 }
 
 impl From<Chapter> for BookItem {
@@ -152,7 +156,7 @@ pub struct Chapter {
     /// Nested items.
     pub sub_items: Vec<BookItem>,
     /// The chapter's location, relative to the `SUMMARY.md` file.
-    pub path: PathBuf,
+    pub path: Option<PathBuf>,
     /// An ordered list of the names of each chapter above this one, in the hierarchy.
     pub parent_names: Vec<String>,
 }
@@ -167,19 +171,39 @@ impl Chapter {
     ) -> Chapter {
         Chapter {
             name: name.to_string(),
-            content: content,
-            path: path.into(),
-            parent_names: parent_names,
+            content,
+            path: Some(path.into()),
+            parent_names,
             ..Default::default()
         }
     }
+
+    /// Create a new draft chapter that is not attached to a source markdown file and has
+    /// thus no content.
+    pub fn new_draft(name: &str, parent_names: Vec<String>) -> Self {
+        Chapter {
+            name: name.to_string(),
+            content: String::new(),
+            path: None,
+            parent_names,
+            ..Default::default()
+        }
+    }
+
+    /// Check if the chapter is a draft chapter, meaning it has no path to a source markdown file
+    pub fn is_draft_chapter(&self) -> bool {
+        match self.path {
+            Some(_) => false,
+            None => true,
+        }
+    }
 }
 
 /// Use the provided `Summary` to load a `Book` from disk.
 ///
 /// You need to pass in the book's source directory because all the links in
 /// `SUMMARY.md` give the chapter locations relative to it.
-fn load_book_from_disk<P: AsRef<Path>>(summary: &Summary, src_dir: P) -> Result<Book> {
+pub(crate) fn load_book_from_disk<P: AsRef<Path>>(summary: &Summary, src_dir: P) -> Result<Book> {
     debug!("Loading the book from disk");
     let src_dir = src_dir.as_ref();
 
@@ -202,16 +226,17 @@ fn load_book_from_disk<P: AsRef<Path>>(summary: &Summary, src_dir: P) -> Result<
     })
 }
 
-fn load_summary_item<P: AsRef<Path>>(
+fn load_summary_item<P: AsRef<Path> + Clone>(
     item: &SummaryItem,
     src_dir: P,
     parent_names: Vec<String>,
 ) -> Result<BookItem> {
-    match *item {
+    match item {
         SummaryItem::Separator => Ok(BookItem::Separator),
         SummaryItem::Link(ref link) => {
-            load_chapter(link, src_dir, parent_names).map(|c| BookItem::Chapter(c))
+            load_chapter(link, src_dir, parent_names).map(BookItem::Chapter)
         }
+        SummaryItem::PartTitle(title) => Ok(BookItem::PartTitle(title.clone())),
     }
 }
 
@@ -220,28 +245,36 @@ fn load_chapter<P: AsRef<Path>>(
     src_dir: P,
     parent_names: Vec<String>,
 ) -> Result<Chapter> {
-    debug!("Loading {} ({})", link.name, link.location.display());
     let src_dir = src_dir.as_ref();
 
-    let location = if link.location.is_absolute() {
-        link.location.clone()
+    let mut ch = if let Some(ref link_location) = link.location {
+        debug!("Loading {} ({})", link.name, link_location.display());
+
+        let location = if link_location.is_absolute() {
+            link_location.clone()
+        } else {
+            src_dir.join(link_location)
+        };
+
+        let mut f = File::open(&location)
+            .with_context(|| format!("Chapter file not found, {}", link_location.display()))?;
+
+        let mut content = String::new();
+        f.read_to_string(&mut content).with_context(|| {
+            format!("Unable to read \"{}\" ({})", link.name, location.display())
+        })?;
+
+        let stripped = location
+            .strip_prefix(&src_dir)
+            .expect("Chapters are always inside a book");
+
+        Chapter::new(&link.name, content, stripped, parent_names.clone())
     } else {
-        src_dir.join(&link.location)
+        Chapter::new_draft(&link.name, parent_names.clone())
     };
 
-    let mut f = File::open(&location)
-        .chain_err(|| format!("Chapter file not found, {}", link.location.display()))?;
-
-    let mut content = String::new();
-    f.read_to_string(&mut content)
-        .chain_err(|| format!("Unable to read \"{}\" ({})", link.name, location.display()))?;
-
-    let stripped = location
-        .strip_prefix(&src_dir)
-        .expect("Chapters are always inside a book");
-
     let mut sub_item_parents = parent_names.clone();
-    let mut ch = Chapter::new(&link.name, content, stripped, parent_names);
+
     ch.number = link.number.clone();
 
     sub_item_parents.push(link.name.clone());
@@ -286,7 +319,7 @@ impl<'a> Iterator for BookItems<'a> {
 }
 
 impl Display for Chapter {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
         if let Some(ref section_number) = self.number {
             write!(f, "{} ", section_number)?;
         }
@@ -301,7 +334,7 @@ mod tests {
     use std::io::Write;
     use tempfile::{Builder as TempFileBuilder, TempDir};
 
-    const DUMMY_SRC: &'static str = "
+    const DUMMY_SRC: &str = "
 # Dummy Chapter
 
 this is some dummy text.
@@ -317,7 +350,7 @@ And here is some \
         let chapter_path = temp.path().join("chapter_1.md");
         File::create(&chapter_path)
             .unwrap()
-            .write(DUMMY_SRC.as_bytes())
+            .write_all(DUMMY_SRC.as_bytes())
             .unwrap();
 
         let link = Link::new("Chapter 1", chapter_path);
@@ -333,7 +366,7 @@ And here is some \
 
         File::create(&second_path)
             .unwrap()
-            .write_all("Hello World!".as_bytes())
+            .write_all(b"Hello World!")
             .unwrap();
 
         let mut second = Link::new("Nested Chapter 1", &second_path);
@@ -376,7 +409,7 @@ And here is some \
             name: String::from("Nested Chapter 1"),
             content: String::from("Hello World!"),
             number: Some(SectionNumber(vec![1, 2])),
-            path: PathBuf::from("second.md"),
+            path: Some(PathBuf::from("second.md")),
             parent_names: vec![String::from("Chapter 1")],
             sub_items: Vec::new(),
         };
@@ -384,7 +417,7 @@ And here is some \
             name: String::from("Chapter 1"),
             content: String::from(DUMMY_SRC),
             number: None,
-            path: PathBuf::from("chapter_1.md"),
+            path: Some(PathBuf::from("chapter_1.md")),
             parent_names: Vec::new(),
             sub_items: vec![
                 BookItem::Chapter(nested.clone()),
@@ -408,7 +441,7 @@ And here is some \
             sections: vec![BookItem::Chapter(Chapter {
                 name: String::from("Chapter 1"),
                 content: String::from(DUMMY_SRC),
-                path: PathBuf::from("chapter_1.md"),
+                path: Some(PathBuf::from("chapter_1.md")),
                 ..Default::default()
             })],
             ..Default::default()
@@ -448,7 +481,7 @@ And here is some \
                     name: String::from("Chapter 1"),
                     content: String::from(DUMMY_SRC),
                     number: None,
-                    path: PathBuf::from("Chapter_1/index.md"),
+                    path: Some(PathBuf::from("Chapter_1/index.md")),
                     parent_names: Vec::new(),
                     sub_items: vec![
                         BookItem::Chapter(Chapter::new(
@@ -481,7 +514,8 @@ And here is some \
             .filter_map(|i| match *i {
                 BookItem::Chapter(ref ch) => Some(ch.name.clone()),
                 _ => None,
-            }).collect();
+            })
+            .collect();
         let should_be: Vec<_> = vec![
             String::from("Chapter 1"),
             String::from("Hello World"),
@@ -499,7 +533,7 @@ And here is some \
                     name: String::from("Chapter 1"),
                     content: String::from(DUMMY_SRC),
                     number: None,
-                    path: PathBuf::from("Chapter_1/index.md"),
+                    path: Some(PathBuf::from("Chapter_1/index.md")),
                     parent_names: Vec::new(),
                     sub_items: vec![
                         BookItem::Chapter(Chapter::new(
@@ -536,9 +570,10 @@ And here is some \
         let summary = Summary {
             numbered_chapters: vec![SummaryItem::Link(Link {
                 name: String::from("Empty"),
-                location: PathBuf::from(""),
+                location: Some(PathBuf::from("")),
                 ..Default::default()
             })],
+
             ..Default::default()
         };
 
@@ -555,7 +590,7 @@ And here is some \
         let summary = Summary {
             numbered_chapters: vec![SummaryItem::Link(Link {
                 name: String::from("nested"),
-                location: dir,
+                location: Some(dir),
                 ..Default::default()
             })],
             ..Default::default()

src/book/init.rs

@@ -1,12 +1,11 @@
 use std::fs::{self, File};
 use std::io::Write;
 use std::path::PathBuf;
-use toml;
 
 use super::MDBook;
-use config::Config;
-use errors::*;
-use theme;
+use crate::config::Config;
+use crate::errors::*;
+use crate::theme;
 
 /// A helper for setting up a new book and its directory structure.
 #[derive(Debug, Clone, PartialEq)]
@@ -65,19 +64,19 @@ impl BookBuilder {
         info!("Creating a new book with stub content");
 
         self.create_directory_structure()
-            .chain_err(|| "Unable to create directory structure")?;
+            .with_context(|| "Unable to create directory structure")?;
 
         self.create_stub_files()
-            .chain_err(|| "Unable to create stub files")?;
+            .with_context(|| "Unable to create stub files")?;
 
         if self.create_gitignore {
             self.build_gitignore()
-                .chain_err(|| "Unable to create .gitignore")?;
+                .with_context(|| "Unable to create .gitignore")?;
         }
 
         if self.copy_theme {
             self.copy_across_theme()
-                .chain_err(|| "Unable to copy across the theme")?;
+                .with_context(|| "Unable to copy across the theme")?;
         }
 
         self.write_book_toml()?;
@@ -98,12 +97,12 @@ impl BookBuilder {
     fn write_book_toml(&self) -> Result<()> {
         debug!("Writing book.toml");
         let book_toml = self.root.join("book.toml");
-        let cfg = toml::to_vec(&self.config).chain_err(|| "Unable to serialize the config")?;
+        let cfg = toml::to_vec(&self.config).with_context(|| "Unable to serialize the config")?;
 
         File::create(book_toml)
-            .chain_err(|| "Couldn't create book.toml")?
+            .with_context(|| "Couldn't create book.toml")?
             .write_all(&cfg)
-            .chain_err(|| "Unable to write config to book.toml")?;
+            .with_context(|| "Unable to write config to book.toml")?;
         Ok(())
     }
 
@@ -144,7 +143,10 @@ impl BookBuilder {
         variables_css.write_all(theme::VARIABLES_CSS)?;
 
         let mut favicon = File::create(themedir.join("favicon.png"))?;
-        favicon.write_all(theme::FAVICON)?;
+        favicon.write_all(theme::FAVICON_PNG)?;
+
+        let mut favicon = File::create(themedir.join("favicon.svg"))?;
+        favicon.write_all(theme::FAVICON_SVG)?;
 
         let mut js = File::create(themedir.join("book.js"))?;
         js.write_all(theme::JS)?;
@@ -173,15 +175,20 @@ impl BookBuilder {
         let src_dir = self.root.join(&self.config.book.src);
 
         let summary = src_dir.join("SUMMARY.md");
-        let mut f = File::create(&summary).chain_err(|| "Unable to create SUMMARY.md")?;
-        writeln!(f, "# Summary")?;
-        writeln!(f, "")?;
-        writeln!(f, "- [Chapter 1](./chapter_1.md)")?;
-
-        let chapter_1 = src_dir.join("chapter_1.md");
-        let mut f = File::create(&chapter_1).chain_err(|| "Unable to create chapter_1.md")?;
-        writeln!(f, "# Chapter 1")?;
+        if !summary.exists() {
+            trace!("No summary found creating stub summary and chapter_1.md.");
+            let mut f = File::create(&summary).with_context(|| "Unable to create SUMMARY.md")?;
+            writeln!(f, "# Summary")?;
+            writeln!(f)?;
+            writeln!(f, "- [Chapter 1](./chapter_1.md)")?;
 
+            let chapter_1 = src_dir.join("chapter_1.md");
+            let mut f =
+                File::create(&chapter_1).with_context(|| "Unable to create chapter_1.md")?;
+            writeln!(f, "# Chapter 1")?;
+        } else {
+            trace!("Existing summary found, no need to create stub files.");
+        }
         Ok(())
     }
 

src/book/mod.rs

@@ -5,6 +5,7 @@
 //!
 //! [1]: ../index.html
 
+#[allow(clippy::module_inception)]
 mod book;
 mod init;
 mod summary;
@@ -16,16 +17,18 @@ pub use self::summary::{parse_summary, Link, SectionNumber, Summary, SummaryItem
 use std::io::Write;
 use std::path::PathBuf;
 use std::process::Command;
+use std::string::ToString;
 use tempfile::Builder as TempFileBuilder;
 use toml::Value;
 
-use errors::*;
-use preprocess::{IndexPreprocessor, LinkPreprocessor, Preprocessor,
-    PreprocessorContext, CmdPreprocessor};
-use renderer::{CmdRenderer, HtmlHandlebars, RenderContext, Renderer};
-use utils;
+use crate::errors::*;
+use crate::preprocess::{
+    CmdPreprocessor, IndexPreprocessor, LinkPreprocessor, Preprocessor, PreprocessorContext,
+};
+use crate::renderer::{CmdRenderer, HtmlHandlebars, MarkdownRenderer, RenderContext, Renderer};
+use crate::utils;
 
-use config::Config;
+use crate::config::{Config, RustEdition};
 
 /// The object used to manage and build a book.
 pub struct MDBook {
@@ -35,10 +38,10 @@ pub struct MDBook {
     pub config: Config,
     /// A representation of the book's contents in memory.
     pub book: Book,
-    renderers: Vec<Box<Renderer>>,
+    renderers: Vec<Box<dyn Renderer>>,
 
     /// List of pre-processors to be run on the book
-    preprocessors: Vec<Box<Preprocessor>>,
+    preprocessors: Vec<Box<dyn Preprocessor>>,
 }
 
 impl MDBook {
@@ -54,7 +57,7 @@ impl MDBook {
             warn!("This format is no longer used, so you should migrate to the");
             warn!("book.toml format.");
             warn!("Check the user guide for migration information:");
-            warn!("\thttps://rust-lang-nursery.github.io/mdBook/format/config.html");
+            warn!("\thttps://rust-lang.github.io/mdBook/format/config.html");
         }
 
         let mut config = if config_location.exists() {
@@ -66,7 +69,7 @@ impl MDBook {
 
         config.update_from_env();
 
-        if log_enabled!(::log::Level::Trace) {
+        if log_enabled!(log::Level::Trace) {
             for line in format!("Config: {:#?}", config).lines() {
                 trace!("{}", line);
             }
@@ -94,21 +97,42 @@ impl MDBook {
         })
     }
 
+    /// Load a book from its root directory using a custom config and a custom summary.
+    pub fn load_with_config_and_summary<P: Into<PathBuf>>(
+        book_root: P,
+        config: Config,
+        summary: Summary,
+    ) -> Result<MDBook> {
+        let root = book_root.into();
+
+        let src_dir = root.join(&config.book.src);
+        let book = book::load_book_from_disk(&summary, &src_dir)?;
+
+        let renderers = determine_renderers(&config);
+        let preprocessors = determine_preprocessors(&config)?;
+
+        Ok(MDBook {
+            root,
+            config,
+            book,
+            renderers,
+            preprocessors,
+        })
+    }
+
     /// Returns a flat depth-first iterator over the elements of the book,
     /// it returns an [BookItem enum](bookitem.html):
     /// `(section: String, bookitem: &BookItem)`
     ///
     /// ```no_run
-    /// # extern crate mdbook;
     /// # use mdbook::MDBook;
     /// # use mdbook::book::BookItem;
-    /// # #[allow(unused_variables)]
-    /// # fn main() {
     /// # let book = MDBook::load("mybook").unwrap();
     /// for item in book.iter() {
     ///     match *item {
     ///         BookItem::Chapter(ref chapter) => {},
     ///         BookItem::Separator => {},
+    ///         BookItem::PartTitle(ref title) => {}
     ///     }
     /// }
     ///
@@ -119,9 +143,8 @@ impl MDBook {
     /// // 2. Chapter 2
     /// //
     /// // etc.
-    /// # }
     /// ```
-    pub fn iter(&self) -> BookItems {
+    pub fn iter(&self) -> BookItems<'_> {
         self.book.iter()
     }
 
@@ -158,17 +181,18 @@ impl MDBook {
     }
 
     /// Run the entire build process for a particular `Renderer`.
-    fn execute_build_process(&self, renderer: &Renderer) -> Result<()> {
+    pub fn execute_build_process(&self, renderer: &dyn Renderer) -> Result<()> {
         let mut preprocessed_book = self.book.clone();
-        let preprocess_ctx = PreprocessorContext::new(self.root.clone(),
-                                     self.config.clone(),
-                                     renderer.name().to_string());
+        let preprocess_ctx = PreprocessorContext::new(
+            self.root.clone(),
+            self.config.clone(),
+            renderer.name().to_string(),
+        );
 
         for preprocessor in &self.preprocessors {
             if preprocessor_should_run(&**preprocessor, renderer, &self.config) {
                 debug!("Running the {} preprocessor.", preprocessor.name());
-                preprocessed_book =
-                    preprocessor.run(&preprocess_ctx, preprocessed_book)?;
+                preprocessed_book = preprocessor.run(&preprocess_ctx, preprocessed_book)?;
             }
         }
 
@@ -178,23 +202,9 @@ impl MDBook {
         Ok(())
     }
 
-    fn render(
-        &self,
-        preprocessed_book: &Book,
-        renderer: &Renderer,
-    ) -> Result<()> {
+    fn render(&self, preprocessed_book: &Book, renderer: &dyn Renderer) -> Result<()> {
         let name = renderer.name();
         let build_dir = self.build_dir_for(name);
-        if build_dir.exists() {
-            debug!(
-                "Cleaning build dir for the \"{}\" renderer ({})",
-                name,
-                build_dir.display()
-            );
-
-            utils::fs::remove_dir_content(&build_dir)
-                .chain_err(|| "Unable to clear output directory")?;
-        }
 
         let render_context = RenderContext::new(
             self.root.clone(),
@@ -205,7 +215,7 @@ impl MDBook {
 
         renderer
             .render(&render_context)
-            .chain_err(|| "Rendering failed")
+            .with_context(|| "Rendering failed")
     }
 
     /// You can change the default renderer to another one by using this method.
@@ -217,7 +227,7 @@ impl MDBook {
     }
 
     /// Register a [`Preprocessor`](../preprocess/trait.Preprocessor.html) to be used when rendering the book.
-    pub fn with_preprecessor<P: Preprocessor + 'static>(&mut self, preprocessor: P) -> &mut Self {
+    pub fn with_preprocessor<P: Preprocessor + 'static>(&mut self, preprocessor: P) -> &mut Self {
         self.preprocessors.push(Box::new(preprocessor));
         self
     }
@@ -233,9 +243,8 @@ impl MDBook {
         let temp_dir = TempFileBuilder::new().prefix("mdbook-").tempdir()?;
 
         // FIXME: Is "test" the proper renderer name to use here?
-        let preprocess_context = PreprocessorContext::new(self.root.clone(),
-                                                          self.config.clone(),
-                                                          "test".to_string());
+        let preprocess_context =
+            PreprocessorContext::new(self.root.clone(), self.config.clone(), "test".to_string());
 
         let book = LinkPreprocessor::new().run(&preprocess_context, self.book.clone())?;
         // Index Preprocessor is disabled so that chapter paths continue to point to the
@@ -243,29 +252,43 @@ impl MDBook {
 
         for item in book.iter() {
             if let BookItem::Chapter(ref ch) = *item {
-                if !ch.path.as_os_str().is_empty() {
-                    let path = self.source_dir().join(&ch.path);
-                    let content = utils::fs::file_to_string(&path)?;
-                    info!("Testing file: {:?}", path);
+                let chapter_path = match ch.path {
+                    Some(ref path) if !path.as_os_str().is_empty() => path,
+                    _ => continue,
+                };
 
-                    // write preprocessed file to tempdir
-                    let path = temp_dir.path().join(&ch.path);
-                    let mut tmpf = utils::fs::create_file(&path)?;
-                    tmpf.write_all(content.as_bytes())?;
+                let path = self.source_dir().join(&chapter_path);
+                info!("Testing file: {:?}", path);
 
-                    let output = Command::new("rustdoc")
-                        .arg(&path)
-                        .arg("--test")
-                        .args(&library_args)
-                        .output()?;
+                // write preprocessed file to tempdir
+                let path = temp_dir.path().join(&chapter_path);
+                let mut tmpf = utils::fs::create_file(&path)?;
+                tmpf.write_all(ch.content.as_bytes())?;
 
-                    if !output.status.success() {
-                        bail!(ErrorKind::Subprocess(
-                            "Rustdoc returned an error".to_string(),
-                            output
-                        ));
+                let mut cmd = Command::new("rustdoc");
+                cmd.arg(&path).arg("--test").args(&library_args);
+
+                if let Some(edition) = self.config.rust.edition {
+                    match edition {
+                        RustEdition::E2015 => {
+                            cmd.args(&["--edition", "2015"]);
+                        }
+                        RustEdition::E2018 => {
+                            cmd.args(&["--edition", "2018"]);
+                        }
                     }
                 }
+
+                let output = cmd.output()?;
+
+                if !output.status.success() {
+                    bail!(
+                        "rustdoc returned an error:\n\
+                        \n--- stdout\n{}\n--- stderr\n{}",
+                        String::from_utf8_lossy(&output.stdout),
+                        String::from_utf8_lossy(&output.stderr)
+                    );
+                }
             }
         }
         Ok(())
@@ -320,19 +343,19 @@ impl MDBook {
 }
 
 /// Look at the `Config` and try to figure out what renderers to use.
-fn determine_renderers(config: &Config) -> Vec<Box<Renderer>> {
-    let mut renderers: Vec<Box<Renderer>> = Vec::new();
+fn determine_renderers(config: &Config) -> Vec<Box<dyn Renderer>> {
+    let mut renderers = Vec::new();
 
-    if let Some(output_table) = config.get("output").and_then(|o| o.as_table()) {
-        for (key, table) in output_table.iter() {
-            // the "html" backend has its own Renderer
+    if let Some(output_table) = config.get("output").and_then(Value::as_table) {
+        renderers.extend(output_table.iter().map(|(key, table)| {
             if key == "html" {
-                renderers.push(Box::new(HtmlHandlebars::new()));
+                Box::new(HtmlHandlebars::new()) as Box<dyn Renderer>
+            } else if key == "markdown" {
+                Box::new(MarkdownRenderer::new()) as Box<dyn Renderer>
             } else {
-                let renderer = interpret_custom_renderer(key, table);
-                renderers.push(renderer);
+                interpret_custom_renderer(key, table)
             }
-        }
+        }));
     }
 
     // if we couldn't find anything, add the HTML renderer as a default
@@ -343,37 +366,31 @@ fn determine_renderers(config: &Config) -> Vec<Box<Renderer>> {
     renderers
 }
 
-fn default_preprocessors() -> Vec<Box<Preprocessor>> {
+fn default_preprocessors() -> Vec<Box<dyn Preprocessor>> {
     vec![
         Box::new(LinkPreprocessor::new()),
         Box::new(IndexPreprocessor::new()),
     ]
 }
 
-fn is_default_preprocessor(pre: &Preprocessor) -> bool {
+fn is_default_preprocessor(pre: &dyn Preprocessor) -> bool {
     let name = pre.name();
     name == LinkPreprocessor::NAME || name == IndexPreprocessor::NAME
 }
 
 /// Look at the `MDBook` and try to figure out what preprocessors to run.
-fn determine_preprocessors(config: &Config) -> Result<Vec<Box<Preprocessor>>> {
+fn determine_preprocessors(config: &Config) -> Result<Vec<Box<dyn Preprocessor>>> {
     let mut preprocessors = Vec::new();
 
     if config.build.use_default_preprocessors {
         preprocessors.extend(default_preprocessors());
     }
 
-    if let Some(preprocessor_table) =
-        config.get("preprocessor").and_then(|v| v.as_table())
-    {
+    if let Some(preprocessor_table) = config.get("preprocessor").and_then(Value::as_table) {
         for key in preprocessor_table.keys() {
             match key.as_ref() {
-                "links" => {
-                    preprocessors.push(Box::new(LinkPreprocessor::new()))
-                }
-                "index" => {
-                    preprocessors.push(Box::new(IndexPreprocessor::new()))
-                }
+                "links" => preprocessors.push(Box::new(LinkPreprocessor::new())),
+                "index" => preprocessors.push(Box::new(IndexPreprocessor::new())),
                 name => preprocessors.push(interpret_custom_preprocessor(
                     name,
                     &preprocessor_table[name],
@@ -385,17 +402,14 @@ fn determine_preprocessors(config: &Config) -> Result<Vec<Box<Preprocessor>>> {
     Ok(preprocessors)
 }
 
-fn interpret_custom_preprocessor(
-    key: &str,
-    table: &Value,
-) -> Box<CmdPreprocessor> {
+fn interpret_custom_preprocessor(key: &str, table: &Value) -> Box<CmdPreprocessor> {
     let command = table
         .get("command")
-        .and_then(|c| c.as_str())
-        .map(|s| s.to_string())
+        .and_then(Value::as_str)
+        .map(ToString::to_string)
         .unwrap_or_else(|| format!("mdbook-{}", key));
 
-    Box::new(CmdPreprocessor::new(key.to_string(), command.to_string()))
+    Box::new(CmdPreprocessor::new(key.to_string(), command))
 }
 
 fn interpret_custom_renderer(key: &str, table: &Value) -> Box<CmdRenderer> {
@@ -403,13 +417,12 @@ fn interpret_custom_renderer(key: &str, table: &Value) -> Box<CmdRenderer> {
     // prepended by "mdbook-"
     let table_dot_command = table
         .get("command")
-        .and_then(|c| c.as_str())
-        .map(|s| s.to_string());
+        .and_then(Value::as_str)
+        .map(ToString::to_string);
 
-    let command =
-        table_dot_command.unwrap_or_else(|| format!("mdbook-{}", key));
+    let command = table_dot_command.unwrap_or_else(|| format!("mdbook-{}", key));
 
-    Box::new(CmdRenderer::new(key.to_string(), command.to_string()))
+    Box::new(CmdRenderer::new(key.to_string(), command))
 }
 
 /// Check whether we should run a particular `Preprocessor` in combination
@@ -418,7 +431,11 @@ fn interpret_custom_renderer(key: &str, table: &Value) -> Box<CmdRenderer> {
 ///
 /// The `build.use-default-preprocessors` config option can be used to ensure
 /// default preprocessors always run if they support the renderer.
-fn preprocessor_should_run(preprocessor: &Preprocessor, renderer: &Renderer, cfg: &Config) -> bool {
+fn preprocessor_should_run(
+    preprocessor: &dyn Preprocessor,
+    renderer: &dyn Renderer,
+    cfg: &Config,
+) -> bool {
     // default preprocessors should be run by default (if supported)
     if cfg.build.use_default_preprocessors && is_default_preprocessor(preprocessor) {
         return preprocessor.supports_renderer(renderer.name());
@@ -428,18 +445,19 @@ fn preprocessor_should_run(preprocessor: &Preprocessor, renderer: &Renderer, cfg
     let renderer_name = renderer.name();
 
     if let Some(Value::Array(ref explicit_renderers)) = cfg.get(&key) {
-        return explicit_renderers.into_iter()
-            .filter_map(|val| val.as_str())
+        return explicit_renderers
+            .iter()
+            .filter_map(Value::as_str)
             .any(|name| name == renderer_name);
     }
 
     preprocessor.supports_renderer(renderer_name)
 }
 
-
 #[cfg(test)]
 mod tests {
     use super::*;
+    use std::str::FromStr;
     use toml::value::{Table, Value};
 
     #[test]
@@ -507,7 +525,7 @@ mod tests {
 
     #[test]
     fn can_determine_third_party_preprocessors() {
-        let cfg_str: &'static str = r#"
+        let cfg_str = r#"
         [book]
         title = "Some Book"
 
@@ -539,17 +557,14 @@ mod tests {
 
         // make sure the `preprocessor.random` table exists
         let random = cfg.get_preprocessor("random").unwrap();
-        let random = interpret_custom_preprocessor(
-            "random",
-            &Value::Table(random.clone()),
-        );
+        let random = interpret_custom_preprocessor("random", &Value::Table(random.clone()));
 
         assert_eq!(random.cmd(), "python random.py");
     }
 
     #[test]
     fn config_respects_preprocessor_selection() {
-        let cfg_str: &'static str = r#"
+        let cfg_str = r#"
         [preprocessor.links]
         renderers = ["html"]
         "#;
@@ -557,11 +572,12 @@ mod tests {
         let cfg = Config::from_str(cfg_str).unwrap();
 
         // double-check that we can access preprocessor.links.renderers[0]
-        let html = cfg.get_preprocessor("links")
+        let html = cfg
+            .get_preprocessor("links")
             .and_then(|links| links.get("renderers"))
-            .and_then(|renderers| renderers.as_array())
+            .and_then(Value::as_array)
             .and_then(|renderers| renderers.get(0))
-            .and_then(|renderer| renderer.as_str())
+            .and_then(Value::as_str)
             .unwrap();
         assert_eq!(html, "html");
         let html_renderer = HtmlHandlebars::default();

src/book/summary.rs

@@ -1,4 +1,4 @@
-use errors::*;
+use crate::errors::*;
 use memchr::{self, Memchr};
 use pulldown_cmark::{self, Event, Tag};
 use std::fmt::{self, Display, Formatter};
@@ -25,12 +25,17 @@ use std::path::{Path, PathBuf};
 /// [Title of prefix element](relative/path/to/markdown.md)
 /// ```
 ///
+/// **Part Title:** An optional title for the next collect of numbered chapters. The numbered
+/// chapters can be broken into as many parts as desired.
+///
 /// **Numbered Chapter:** Numbered chapters are the main content of the book,
 /// they
 /// will be numbered and can be nested, resulting in a nice hierarchy (chapters,
 /// sub-chapters, etc.)
 ///
 /// ```markdown
+/// # Title of Part
+///
 /// - [Title of the Chapter](relative/path/to/markdown.md)
 /// ```
 ///
@@ -55,7 +60,7 @@ pub struct Summary {
     pub title: Option<String>,
     /// Chapters before the main text (e.g. an introduction).
     pub prefix_chapters: Vec<SummaryItem>,
-    /// The main chapters in the document.
+    /// The main numbered chapters of the book, broken into one or more possibly named parts.
     pub numbered_chapters: Vec<SummaryItem>,
     /// Items which come after the main document (e.g. a conclusion).
     pub suffix_chapters: Vec<SummaryItem>,
@@ -71,7 +76,7 @@ pub struct Link {
     pub name: String,
     /// The location of the chapter's source file, taking the book's `src`
     /// directory as the root.
-    pub location: PathBuf,
+    pub location: Option<PathBuf>,
     /// The section number, if this chapter is in the numbered section.
     pub number: Option<SectionNumber>,
     /// Any nested items this chapter may contain.
@@ -83,7 +88,7 @@ impl Link {
     pub fn new<S: Into<String>, P: AsRef<Path>>(name: S, location: P) -> Link {
         Link {
             name: name.into(),
-            location: location.as_ref().to_path_buf(),
+            location: Some(location.as_ref().to_path_buf()),
             number: None,
             nested_items: Vec::new(),
         }
@@ -94,7 +99,7 @@ impl Default for Link {
     fn default() -> Self {
         Link {
             name: String::new(),
-            location: PathBuf::new(),
+            location: Some(PathBuf::new()),
             number: None,
             nested_items: Vec::new(),
         }
@@ -108,6 +113,8 @@ pub enum SummaryItem {
     Link(Link),
     /// A separator (`---`).
     Separator,
+    /// A part title.
+    PartTitle(String),
 }
 
 impl SummaryItem {
@@ -134,12 +141,13 @@ impl From<Link> for SummaryItem {
 ///
 /// ```text
 /// summary           ::= title prefix_chapters numbered_chapters
-/// suffix_chapters
+///                         suffix_chapters
 /// title             ::= "# " TEXT
 ///                     | EPSILON
 /// prefix_chapters   ::= item*
 /// suffix_chapters   ::= item*
-/// numbered_chapters ::= dotted_item+
+/// numbered_chapters ::= part+
+/// part              ::= title dotted_item+
 /// dotted_item       ::= INDENT* DOT_POINT item
 /// item              ::= link
 ///                     | separator
@@ -153,7 +161,12 @@ impl From<Link> for SummaryItem {
 /// > match the following regex: "[^<>\n[]]+".
 struct SummaryParser<'a> {
     src: &'a str,
-    stream: pulldown_cmark::Parser<'a>,
+    stream: pulldown_cmark::OffsetIter<'a>,
+    offset: usize,
+
+    /// We can't actually put an event back into the `OffsetIter` stream, so instead we store it
+    /// here until somebody calls `next_event` again.
+    back: Option<Event<'a>>,
 }
 
 /// Reads `Events` from the provided stream until the corresponding
@@ -174,7 +187,7 @@ macro_rules! collect_events {
         let mut events = Vec::new();
 
         loop {
-            let event = $stream.next();
+            let event = $stream.next().map(|(ev, _range)| ev);
             trace!("Next event: {:?}", event);
 
             match event {
@@ -195,24 +208,24 @@ macro_rules! collect_events {
 }
 
 impl<'a> SummaryParser<'a> {
-    fn new(text: &str) -> SummaryParser {
-        let pulldown_parser = pulldown_cmark::Parser::new(text);
+    fn new(text: &str) -> SummaryParser<'_> {
+        let pulldown_parser = pulldown_cmark::Parser::new(text).into_offset_iter();
 
         SummaryParser {
             src: text,
             stream: pulldown_parser,
+            offset: 0,
+            back: None,
         }
     }
 
     /// Get the current line and column to give the user more useful error
     /// messages.
     fn current_location(&self) -> (usize, usize) {
-        let byte_offset = self.stream.get_offset();
-
-        let previous_text = self.src[..byte_offset].as_bytes();
+        let previous_text = self.src[..self.offset].as_bytes();
         let line = Memchr::new(b'\n', previous_text).count() + 1;
         let start_of_line = memchr::memrchr(b'\n', previous_text).unwrap_or(0);
-        let col = self.src[start_of_line..byte_offset].chars().count();
+        let col = self.src[start_of_line..self.offset].chars().count();
 
         (line, col)
     }
@@ -223,13 +236,13 @@ impl<'a> SummaryParser<'a> {
 
         let prefix_chapters = self
             .parse_affix(true)
-            .chain_err(|| "There was an error parsing the prefix chapters")?;
+            .with_context(|| "There was an error parsing the prefix chapters")?;
         let numbered_chapters = self
-            .parse_numbered()
-            .chain_err(|| "There was an error parsing the numbered chapters")?;
+            .parse_parts()
+            .with_context(|| "There was an error parsing the numbered chapters")?;
         let suffix_chapters = self
             .parse_affix(false)
-            .chain_err(|| "There was an error parsing the suffix chapters")?;
+            .with_context(|| "There was an error parsing the suffix chapters")?;
 
         Ok(Summary {
             title,
@@ -239,8 +252,7 @@ impl<'a> SummaryParser<'a> {
         })
     }
 
-    /// Parse the affix chapters. This expects the first event (start of
-    /// paragraph) to have already been consumed by the previous parser.
+    /// Parse the affix chapters.
     fn parse_affix(&mut self, is_prefix: bool) -> Result<Vec<SummaryItem>> {
         let mut items = Vec::new();
         debug!(
@@ -250,20 +262,22 @@ impl<'a> SummaryParser<'a> {
 
         loop {
             match self.next_event() {
-                Some(Event::Start(Tag::List(..))) => {
+                Some(ev @ Event::Start(Tag::List(..)))
+                | Some(ev @ Event::Start(Tag::Heading(1))) => {
                     if is_prefix {
                         // we've finished prefix chapters and are at the start
                         // of the numbered section.
+                        self.back(ev);
                         break;
                     } else {
                         bail!(self.parse_error("Suffix chapters cannot be followed by a list"));
                     }
                 }
-                Some(Event::Start(Tag::Link(href, _))) => {
-                    let link = self.parse_link(href.to_string())?;
+                Some(Event::Start(Tag::Link(_type, href, _title))) => {
+                    let link = self.parse_link(href.to_string());
                     items.push(SummaryItem::Link(link));
                 }
-                Some(Event::Start(Tag::Rule)) => items.push(SummaryItem::Separator),
+                Some(Event::Rule) => items.push(SummaryItem::Separator),
                 Some(_) => {}
                 None => break,
             }
@@ -272,57 +286,111 @@ impl<'a> SummaryParser<'a> {
         Ok(items)
     }
 
-    fn parse_link(&mut self, href: String) -> Result<Link> {
+    fn parse_parts(&mut self) -> Result<Vec<SummaryItem>> {
+        let mut parts = vec![];
+
+        // We want the section numbers to be continues through all parts.
+        let mut root_number = SectionNumber::default();
+        let mut root_items = 0;
+
+        loop {
+            // Possibly match a title or the end of the "numbered chapters part".
+            let title = match self.next_event() {
+                Some(ev @ Event::Start(Tag::Paragraph)) => {
+                    // we're starting the suffix chapters
+                    self.back(ev);
+                    break;
+                }
+
+                Some(Event::Start(Tag::Heading(1))) => {
+                    debug!("Found a h1 in the SUMMARY");
+
+                    let tags = collect_events!(self.stream, end Tag::Heading(1));
+                    Some(stringify_events(tags))
+                }
+
+                Some(ev) => {
+                    self.back(ev);
+                    None
+                }
+
+                None => break, // EOF, bail...
+            };
+
+            // Parse the rest of the part.
+            let numbered_chapters = self
+                .parse_numbered(&mut root_items, &mut root_number)
+                .with_context(|| "There was an error parsing the numbered chapters")?;
+
+            if let Some(title) = title {
+                parts.push(SummaryItem::PartTitle(title));
+            }
+            parts.extend(numbered_chapters);
+        }
+
+        Ok(parts)
+    }
+
+    /// Finishes parsing a link once the `Event::Start(Tag::Link(..))` has been opened.
+    fn parse_link(&mut self, href: String) -> Link {
         let link_content = collect_events!(self.stream, end Tag::Link(..));
         let name = stringify_events(link_content);
 
-        if href.is_empty() {
-            Err(self.parse_error("You can't have an empty link."))
+        let path = if href.is_empty() {
+            None
         } else {
-            Ok(Link {
-                name: name,
-                location: PathBuf::from(href.to_string()),
-                number: None,
-                nested_items: Vec::new(),
-            })
+            Some(PathBuf::from(href))
+        };
+
+        Link {
+            name,
+            location: path,
+            number: None,
+            nested_items: Vec::new(),
         }
     }
 
-    /// Parse the numbered chapters. This assumes the opening list tag has
-    /// already been consumed by a previous parser.
-    fn parse_numbered(&mut self) -> Result<Vec<SummaryItem>> {
+    /// Parse the numbered chapters.
+    fn parse_numbered(
+        &mut self,
+        root_items: &mut u32,
+        root_number: &mut SectionNumber,
+    ) -> Result<Vec<SummaryItem>> {
         let mut items = Vec::new();
-        let mut root_items = 0;
-        let root_number = SectionNumber::default();
 
-        // we need to do this funny loop-match-if-let dance because a rule will
-        // close off any currently running list. Therefore we try to read the
-        // list items before the rule, then if we encounter a rule we'll add a
-        // separator and try to resume parsing numbered chapters if we start a
-        // list immediately afterwards.
-        //
-        // If you can think of a better way to do this then please make a PR :)
+        // For the first iteration, we want to just skip any opening paragraph tags, as that just
+        // marks the start of the list. But after that, another opening paragraph indicates that we
+        // have started a new part or the suffix chapters.
+        let mut first = true;
 
         loop {
-            let mut bunch_of_items = self.parse_nested_numbered(&root_number)?;
-
-            // if we've resumed after something like a rule the root sections
-            // will be numbered from 1. We need to manually go back and update
-            // them
-            update_section_numbers(&mut bunch_of_items, 0, root_items);
-            root_items += bunch_of_items.len() as u32;
-            items.extend(bunch_of_items);
-
-
             match self.next_event() {
-                Some(Event::Start(Tag::Paragraph)) => {
-                    // we're starting the suffix chapters
+                Some(ev @ Event::Start(Tag::Paragraph)) => {
+                    if !first {
+                        // we're starting the suffix chapters
+                        self.back(ev);
+                        break;
+                    }
+                }
+                // The expectation is that pulldown cmark will terminate a paragraph before a new
+                // heading, so we can always count on this to return without skipping headings.
+                Some(ev @ Event::Start(Tag::Heading(1))) => {
+                    // we're starting a new part
+                    self.back(ev);
                     break;
                 }
+                Some(ev @ Event::Start(Tag::List(..))) => {
+                    self.back(ev);
+                    let mut bunch_of_items = self.parse_nested_numbered(&root_number)?;
+
+                    // if we've resumed after something like a rule the root sections
+                    // will be numbered from 1. We need to manually go back and update
+                    // them
+                    update_section_numbers(&mut bunch_of_items, 0, *root_items);
+                    *root_items += bunch_of_items.len() as u32;
+                    items.extend(bunch_of_items);
+                }
                 Some(Event::Start(other_tag)) => {
-                    if other_tag == Tag::Rule {
-                        items.push(SummaryItem::Separator);
-                    }
                     trace!("Skipping contents of {:?}", other_tag);
 
                     // Skip over the contents of this tag
@@ -331,29 +399,42 @@ impl<'a> SummaryParser<'a> {
                             break;
                         }
                     }
+                }
+                Some(Event::Rule) => {
+                    items.push(SummaryItem::Separator);
+                }
 
-                    if let Some(Event::Start(Tag::List(..))) = self.next_event() {
-                        continue;
-                    } else {
-                        break;
-                    }
-                }
-                Some(_) => {
-                    // something else... ignore
-                    continue;
-                }
+                // something else... ignore
+                Some(_) => {}
+
+                // EOF, bail...
                 None => {
-                    // EOF, bail...
                     break;
                 }
             }
+
+            // From now on, we cannot accept any new paragraph opening tags.
+            first = false;
         }
 
         Ok(items)
     }
 
+    /// Push an event back to the tail of the stream.
+    fn back(&mut self, ev: Event<'a>) {
+        assert!(self.back.is_none());
+        trace!("Back: {:?}", ev);
+        self.back = Some(ev);
+    }
+
     fn next_event(&mut self) -> Option<Event<'a>> {
-        let next = self.stream.next();
+        let next = self.back.take().or_else(|| {
+            self.stream.next().map(|(ev, range)| {
+                self.offset = range.start;
+                ev
+            })
+        });
+
         trace!("Next event: {:?}", next);
 
         next
@@ -370,6 +451,10 @@ impl<'a> SummaryParser<'a> {
                     items.push(item);
                 }
                 Some(Event::Start(Tag::List(..))) => {
+                    // Skip this tag after comment bacause it is not nested.
+                    if items.is_empty() {
+                        continue;
+                    }
                     // recurse to parse the nested list
                     let (_, last_item) = get_last_link(&mut items)?;
                     let last_item_number = last_item
@@ -398,8 +483,8 @@ impl<'a> SummaryParser<'a> {
         loop {
             match self.next_event() {
                 Some(Event::Start(Tag::Paragraph)) => continue,
-                Some(Event::Start(Tag::Link(href, _))) => {
-                    let mut link = self.parse_link(href.to_string())?;
+                Some(Event::Start(Tag::Link(_type, href, _title))) => {
+                    let mut link = self.parse_link(href.to_string());
 
                     let mut number = parent.clone();
                     number.0.push(num_existing_items as u32 + 1);
@@ -407,7 +492,10 @@ impl<'a> SummaryParser<'a> {
                         "Found chapter: {} {} ({})",
                         number,
                         link.name,
-                        link.location.display()
+                        link.location
+                            .as_ref()
+                            .map(|p| p.to_str().unwrap_or(""))
+                            .unwrap_or("[draft]")
                     );
 
                     link.number = Some(number);
@@ -426,19 +514,24 @@ impl<'a> SummaryParser<'a> {
 
     fn parse_error<D: Display>(&self, msg: D) -> Error {
         let (line, col) = self.current_location();
-
-        ErrorKind::ParseError(line, col, msg.to_string()).into()
+        anyhow::anyhow!(
+            "failed to parse SUMMARY.md line {}, column {}: {}",
+            line,
+            col,
+            msg
+        )
     }
 
     /// Try to parse the title line.
     fn parse_title(&mut self) -> Option<String> {
-        if let Some(Event::Start(Tag::Header(1))) = self.next_event() {
-            debug!("Found a h1 in the SUMMARY");
+        match self.next_event() {
+            Some(Event::Start(Tag::Heading(1))) => {
+                debug!("Found a h1 in the SUMMARY");
 
-            let tags = collect_events!(self.stream, end Tag::Header(1));
-            Some(stringify_events(tags))
-        } else {
-            None
+                let tags = collect_events!(self.stream, end Tag::Heading(1));
+                Some(stringify_events(tags))
+            }
+            _ => None,
         }
     }
 }
@@ -464,21 +557,21 @@ fn get_last_link(links: &mut [SummaryItem]) -> Result<(usize, &mut Link)> {
         .filter_map(|(i, item)| item.maybe_link_mut().map(|l| (i, l)))
         .rev()
         .next()
-        .ok_or_else(|| {
-            "Unable to get last link because the list of SummaryItems doesn't contain any Links"
-                .into()
-        })
+        .ok_or_else(||
+            anyhow::anyhow!("Unable to get last link because the list of SummaryItems doesn't contain any Links")
+            )
 }
 
 /// Removes the styling from a list of Markdown events and returns just the
 /// plain text.
-fn stringify_events(events: Vec<Event>) -> String {
+fn stringify_events(events: Vec<Event<'_>>) -> String {
     events
         .into_iter()
         .filter_map(|t| match t {
-            Event::Text(text) => Some(text.into_owned()),
+            Event::Text(text) | Event::Code(text) => Some(text.into_string()),
             _ => None,
-        }).collect()
+        })
+        .collect()
 }
 
 /// A section number like "1.2.3", basically just a newtype'd `Vec<u32>` with
@@ -487,7 +580,7 @@ fn stringify_events(events: Vec<Event>) -> String {
 pub struct SectionNumber(pub Vec<u32>);
 
 impl Display for SectionNumber {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
         if self.0.is_empty() {
             write!(f, "0")
         } else {
@@ -577,17 +670,16 @@ mod tests {
         let should_be = vec![
             SummaryItem::Link(Link {
                 name: String::from("First"),
-                location: PathBuf::from("./first.md"),
+                location: Some(PathBuf::from("./first.md")),
                 ..Default::default()
             }),
             SummaryItem::Link(Link {
                 name: String::from("Second"),
-                location: PathBuf::from("./second.md"),
+                location: Some(PathBuf::from("./second.md")),
                 ..Default::default()
             }),
         ];
 
-        let _ = parser.stream.next(); // step past first event
         let got = parser.parse_affix(true).unwrap();
 
         assert_eq!(got, should_be);
@@ -598,7 +690,6 @@ mod tests {
         let src = "[First](./first.md)\n\n---\n\n[Second](./second.md)\n";
         let mut parser = SummaryParser::new(src);
 
-        let _ = parser.stream.next(); // step past first event
         let got = parser.parse_affix(true).unwrap();
 
         assert_eq!(got.len(), 3);
@@ -610,7 +701,6 @@ mod tests {
         let src = "[First](./first.md)\n- [Second](./second.md)\n";
         let mut parser = SummaryParser::new(src);
 
-        let _ = parser.stream.next(); // step past first event
         let got = parser.parse_affix(false);
 
         assert!(got.is_err());
@@ -621,19 +711,19 @@ mod tests {
         let src = "[First](./first.md)";
         let should_be = Link {
             name: String::from("First"),
-            location: PathBuf::from("./first.md"),
+            location: Some(PathBuf::from("./first.md")),
             ..Default::default()
         };
 
         let mut parser = SummaryParser::new(src);
-        let _ = parser.stream.next(); // skip past start of paragraph
+        let _ = parser.stream.next(); // Discard opening paragraph
 
         let href = match parser.stream.next() {
-            Some(Event::Start(Tag::Link(href, _))) => href.to_string(),
+            Some((Event::Start(Tag::Link(_type, href, _title)), _range)) => href.to_string(),
             other => panic!("Unreachable, {:?}", other),
         };
 
-        let got = parser.parse_link(href).unwrap();
+        let got = parser.parse_link(href);
         assert_eq!(got, should_be);
     }
 
@@ -642,16 +732,16 @@ mod tests {
         let src = "- [First](./first.md)\n";
         let link = Link {
             name: String::from("First"),
-            location: PathBuf::from("./first.md"),
+            location: Some(PathBuf::from("./first.md")),
             number: Some(SectionNumber(vec![1])),
             ..Default::default()
         };
         let should_be = vec![SummaryItem::Link(link)];
 
         let mut parser = SummaryParser::new(src);
-        let _ = parser.stream.next();
-
-        let got = parser.parse_numbered().unwrap();
+        let got = parser
+            .parse_numbered(&mut 0, &mut SectionNumber::default())
+            .unwrap();
 
         assert_eq!(got, should_be);
     }
@@ -663,27 +753,92 @@ mod tests {
         let should_be = vec![
             SummaryItem::Link(Link {
                 name: String::from("First"),
-                location: PathBuf::from("./first.md"),
+                location: Some(PathBuf::from("./first.md")),
                 number: Some(SectionNumber(vec![1])),
                 nested_items: vec![SummaryItem::Link(Link {
                     name: String::from("Nested"),
-                    location: PathBuf::from("./nested.md"),
+                    location: Some(PathBuf::from("./nested.md")),
                     number: Some(SectionNumber(vec![1, 1])),
                     nested_items: Vec::new(),
                 })],
             }),
             SummaryItem::Link(Link {
                 name: String::from("Second"),
-                location: PathBuf::from("./second.md"),
+                location: Some(PathBuf::from("./second.md")),
                 number: Some(SectionNumber(vec![2])),
                 nested_items: Vec::new(),
             }),
         ];
 
         let mut parser = SummaryParser::new(src);
-        let _ = parser.stream.next();
+        let got = parser
+            .parse_numbered(&mut 0, &mut SectionNumber::default())
+            .unwrap();
 
-        let got = parser.parse_numbered().unwrap();
+        assert_eq!(got, should_be);
+    }
+
+    #[test]
+    fn parse_numbered_chapters_separated_by_comment() {
+        let src = "- [First](./first.md)\n<!-- this is a comment -->\n- [Second](./second.md)";
+
+        let should_be = vec![
+            SummaryItem::Link(Link {
+                name: String::from("First"),
+                location: Some(PathBuf::from("./first.md")),
+                number: Some(SectionNumber(vec![1])),
+                nested_items: Vec::new(),
+            }),
+            SummaryItem::Link(Link {
+                name: String::from("Second"),
+                location: Some(PathBuf::from("./second.md")),
+                number: Some(SectionNumber(vec![2])),
+                nested_items: Vec::new(),
+            }),
+        ];
+
+        let mut parser = SummaryParser::new(src);
+        let got = parser
+            .parse_numbered(&mut 0, &mut SectionNumber::default())
+            .unwrap();
+
+        assert_eq!(got, should_be);
+    }
+
+    #[test]
+    fn parse_titled_parts() {
+        let src = "- [First](./first.md)\n- [Second](./second.md)\n\
+                   # Title 2\n- [Third](./third.md)\n\t- [Fourth](./fourth.md)";
+
+        let should_be = vec![
+            SummaryItem::Link(Link {
+                name: String::from("First"),
+                location: Some(PathBuf::from("./first.md")),
+                number: Some(SectionNumber(vec![1])),
+                nested_items: Vec::new(),
+            }),
+            SummaryItem::Link(Link {
+                name: String::from("Second"),
+                location: Some(PathBuf::from("./second.md")),
+                number: Some(SectionNumber(vec![2])),
+                nested_items: Vec::new(),
+            }),
+            SummaryItem::PartTitle(String::from("Title 2")),
+            SummaryItem::Link(Link {
+                name: String::from("Third"),
+                location: Some(PathBuf::from("./third.md")),
+                number: Some(SectionNumber(vec![3])),
+                nested_items: vec![SummaryItem::Link(Link {
+                    name: String::from("Fourth"),
+                    location: Some(PathBuf::from("./fourth.md")),
+                    number: Some(SectionNumber(vec![3, 1])),
+                    nested_items: Vec::new(),
+                })],
+            }),
+        ];
+
+        let mut parser = SummaryParser::new(src);
+        let got = parser.parse_parts().unwrap();
 
         assert_eq!(got, should_be);
     }
@@ -698,68 +853,76 @@ mod tests {
         let should_be = vec![
             SummaryItem::Link(Link {
                 name: String::from("First"),
-                location: PathBuf::from("./first.md"),
+                location: Some(PathBuf::from("./first.md")),
                 number: Some(SectionNumber(vec![1])),
                 nested_items: Vec::new(),
             }),
             SummaryItem::Link(Link {
                 name: String::from("Second"),
-                location: PathBuf::from("./second.md"),
+                location: Some(PathBuf::from("./second.md")),
                 number: Some(SectionNumber(vec![2])),
                 nested_items: Vec::new(),
             }),
         ];
 
         let mut parser = SummaryParser::new(src);
-        let _ = parser.stream.next();
-
-        let got = parser.parse_numbered().unwrap();
+        let got = parser
+            .parse_numbered(&mut 0, &mut SectionNumber::default())
+            .unwrap();
 
         assert_eq!(got, should_be);
     }
 
     #[test]
-    fn an_empty_link_location_is_an_error() {
+    fn an_empty_link_location_is_a_draft_chapter() {
         let src = "- [Empty]()\n";
         let mut parser = SummaryParser::new(src);
-        parser.stream.next();
 
-        let got = parser.parse_numbered();
-        assert!(got.is_err());
+        let got = parser.parse_numbered(&mut 0, &mut SectionNumber::default());
+        let should_be = vec![SummaryItem::Link(Link {
+            name: String::from("Empty"),
+            location: None,
+            number: Some(SectionNumber(vec![1])),
+            nested_items: Vec::new(),
+        })];
+
+        assert!(got.is_ok());
+        assert_eq!(got.unwrap(), should_be);
     }
 
-    /// Regression test for https://github.com/rust-lang-nursery/mdBook/issues/779
+    /// Regression test for https://github.com/rust-lang/mdBook/issues/779
     /// Ensure section numbers are correctly incremented after a horizontal separator.
     #[test]
     fn keep_numbering_after_separator() {
-        let src = "- [First](./first.md)\n---\n- [Second](./second.md)\n---\n- [Third](./third.md)\n";
+        let src =
+            "- [First](./first.md)\n---\n- [Second](./second.md)\n---\n- [Third](./third.md)\n";
         let should_be = vec![
             SummaryItem::Link(Link {
                 name: String::from("First"),
-                location: PathBuf::from("./first.md"),
+                location: Some(PathBuf::from("./first.md")),
                 number: Some(SectionNumber(vec![1])),
                 nested_items: Vec::new(),
             }),
             SummaryItem::Separator,
             SummaryItem::Link(Link {
                 name: String::from("Second"),
-                location: PathBuf::from("./second.md"),
+                location: Some(PathBuf::from("./second.md")),
                 number: Some(SectionNumber(vec![2])),
                 nested_items: Vec::new(),
             }),
             SummaryItem::Separator,
             SummaryItem::Link(Link {
                 name: String::from("Third"),
-                location: PathBuf::from("./third.md"),
+                location: Some(PathBuf::from("./third.md")),
                 number: Some(SectionNumber(vec![3])),
                 nested_items: Vec::new(),
             }),
         ];
 
         let mut parser = SummaryParser::new(src);
-        let _ = parser.stream.next();
-
-        let got = parser.parse_numbered().unwrap();
+        let got = parser
+            .parse_numbered(&mut 0, &mut SectionNumber::default())
+            .unwrap();
 
         assert_eq!(got, should_be);
     }

src/cmd/build.rs

@@ -1,7 +1,7 @@
+use crate::{get_book_dir, open};
 use clap::{App, ArgMatches, SubCommand};
 use mdbook::errors::Result;
 use mdbook::MDBook;
-use {get_book_dir, open};
 
 // Create clap subcommand arguments
 pub fn make_subcommand<'a, 'b>() -> App<'a, 'b> {
@@ -9,11 +9,14 @@ pub fn make_subcommand<'a, 'b>() -> App<'a, 'b> {
         .about("Builds a book from its markdown files")
         .arg_from_usage(
             "-d, --dest-dir=[dest-dir] 'Output directory for the book{n}\
-             (If omitted, uses build.build-dir from book.toml or defaults to ./book)'",
-        ).arg_from_usage(
+             Relative paths are interpreted relative to the book's root directory.{n}\
+             If omitted, mdBook uses build.build-dir from book.toml or defaults to `./book`.'",
+        )
+        .arg_from_usage(
             "[dir] 'Root directory for the book{n}\
              (Defaults to the Current Directory when omitted)'",
-        ).arg_from_usage("-o, --open 'Opens the compiled book in a web browser'")
+        )
+        .arg_from_usage("-o, --open 'Opens the compiled book in a web browser'")
 }
 
 // Build command implementation

src/cmd/clean.rs

@@ -1,6 +1,6 @@
+use crate::get_book_dir;
+use anyhow::Context;
 use clap::{App, ArgMatches, SubCommand};
-use get_book_dir;
-use mdbook::errors::*;
 use mdbook::MDBook;
 use std::fs;
 
@@ -10,15 +10,18 @@ pub fn make_subcommand<'a, 'b>() -> App<'a, 'b> {
         .about("Deletes a built book")
         .arg_from_usage(
             "-d, --dest-dir=[dest-dir] 'Output directory for the book{n}\
-             (If omitted, uses build.build-dir from book.toml or defaults to ./book)'",
-        ).arg_from_usage(
+             Relative paths are interpreted relative to the book's root directory.{n}\
+             Running this command deletes this directory.{n}\
+             If omitted, mdBook uses build.build-dir from book.toml or defaults to `./book`.'",
+        )
+        .arg_from_usage(
             "[dir] 'Root directory for the book{n}\
              (Defaults to the Current Directory when omitted)'",
         )
 }
 
 // Clean command implementation
-pub fn execute(args: &ArgMatches) -> ::mdbook::errors::Result<()> {
+pub fn execute(args: &ArgMatches) -> mdbook::errors::Result<()> {
     let book_dir = get_book_dir(args);
     let book = MDBook::load(&book_dir)?;
 
@@ -26,7 +29,11 @@ pub fn execute(args: &ArgMatches) -> ::mdbook::errors::Result<()> {
         Some(dest_dir) => dest_dir.into(),
         None => book.root.join(&book.config.build.build_dir),
     };
-    fs::remove_dir_all(&dir_to_remove).chain_err(|| "Unable to remove the build directory")?;
+
+    if dir_to_remove.exists() {
+        fs::remove_dir_all(&dir_to_remove)
+            .with_context(|| "Unable to remove the build directory")?;
+    }
 
     Ok(())
 }

src/cmd/init.rs

@@ -1,5 +1,5 @@
+use crate::get_book_dir;
 use clap::{App, ArgMatches, SubCommand};
-use get_book_dir;
 use mdbook::config;
 use mdbook::errors::Result;
 use mdbook::MDBook;
@@ -12,8 +12,10 @@ pub fn make_subcommand<'a, 'b>() -> App<'a, 'b> {
     SubCommand::with_name("init")
         .about("Creates the boilerplate structure and files for a new book")
         // the {n} denotes a newline which will properly aligned in all help messages
-        .arg_from_usage("[dir] 'Directory to create the book in{n}\
-            (Defaults to the Current Directory when omitted)'")
+        .arg_from_usage(
+            "[dir] 'Directory to create the book in{n}\
+             (Defaults to the Current Directory when omitted)'",
+        )
         .arg_from_usage("--theme 'Copies the default theme into your source folder'")
         .arg_from_usage("--force 'Skips confirmation prompts'")
 }

src/cmd/serve.rs

@@ -1,20 +1,21 @@
-extern crate iron;
-extern crate staticfile;
-extern crate ws;
-
-use self::iron::{
-    status, AfterMiddleware, Chain, Iron, IronError, IronResult, Request, Response, Set,
-};
 #[cfg(feature = "watch")]
 use super::watch;
+use crate::{get_book_dir, open};
 use clap::{App, Arg, ArgMatches, SubCommand};
+use futures_util::sink::SinkExt;
+use futures_util::StreamExt;
 use mdbook::errors::*;
 use mdbook::utils;
+use mdbook::utils::fs::get_404_output_file;
 use mdbook::MDBook;
-use std;
-use {get_book_dir, open};
+use std::net::{SocketAddr, ToSocketAddrs};
+use std::path::PathBuf;
+use tokio::sync::broadcast;
+use warp::ws::Message;
+use warp::Filter;
 
-struct ErrorRecover;
+/// The HTTP endpoint for the websocket used to trigger reloads when a file changes.
+const LIVE_RELOAD_ENDPOINT: &str = "__livereload";
 
 // Create clap subcommand arguments
 pub fn make_subcommand<'a, 'b>() -> App<'a, 'b> {
@@ -22,7 +23,8 @@ pub fn make_subcommand<'a, 'b>() -> App<'a, 'b> {
         .about("Serves a book at http://localhost:3000, and rebuilds it on changes")
         .arg_from_usage(
             "-d, --dest-dir=[dest-dir] 'Output directory for the book{n}\
-             (If omitted, uses build.build-dir from book.toml or defaults to ./book)'",
+             Relative paths are interpreted relative to the book's root directory.{n}\
+             If omitted, mdBook uses build.build-dir from book.toml or defaults to `./book`.'",
         )
         .arg_from_usage(
             "[dir] 'Root directory for the book{n}\
@@ -46,64 +48,53 @@ pub fn make_subcommand<'a, 'b>() -> App<'a, 'b> {
                 .empty_values(false)
                 .help("Port to use for HTTP connections"),
         )
-        .arg(
-            Arg::with_name("websocket-hostname")
-                .long("websocket-hostname")
-                .takes_value(true)
-                .empty_values(false)
-                .help(
-                    "Hostname to connect to for WebSockets connections (Defaults to the HTTP hostname)",
-                ),
-        )
-        .arg(
-            Arg::with_name("websocket-port")
-                .short("w")
-                .long("websocket-port")
-                .takes_value(true)
-                .default_value("3001")
-                .empty_values(false)
-                .help("Port to use for WebSockets livereload connections"),
-        )
         .arg_from_usage("-o, --open 'Opens the book server in a web browser'")
 }
 
-// Watch command implementation
+// Serve command implementation
 pub fn execute(args: &ArgMatches) -> Result<()> {
     let book_dir = get_book_dir(args);
     let mut book = MDBook::load(&book_dir)?;
 
     let port = args.value_of("port").unwrap();
-    let ws_port = args.value_of("websocket-port").unwrap();
     let hostname = args.value_of("hostname").unwrap();
-    let public_address = args.value_of("websocket-address").unwrap_or(hostname);
     let open_browser = args.is_present("open");
 
     let address = format!("{}:{}", hostname, port);
-    let ws_address = format!("{}:{}", hostname, ws_port);
-
-    let livereload_url = format!("ws://{}:{}", public_address, ws_port);
-    book.config
-        .set("output.html.livereload-url", &livereload_url)?;
-
-    if let Some(dest_dir) = args.value_of("dest-dir") {
-        book.config.build.build_dir = dest_dir.into();
-    }
 
+    let livereload_url = format!("ws://{}/{}", address, LIVE_RELOAD_ENDPOINT);
+    let update_config = |book: &mut MDBook| {
+        book.config
+            .set("output.html.livereload-url", &livereload_url)
+            .expect("livereload-url update failed");
+        if let Some(dest_dir) = args.value_of("dest-dir") {
+            book.config.build.build_dir = dest_dir.into();
+        }
+        // Override site-url for local serving of the 404 file
+        book.config.set("output.html.site-url", "/").unwrap();
+    };
+    update_config(&mut book);
     book.build()?;
 
-    let mut chain = Chain::new(staticfile::Static::new(book.build_dir_for("html")));
-    chain.link_after(ErrorRecover);
-    let _iron = Iron::new(chain)
-        .http(&*address)
-        .chain_err(|| "Unable to launch the server")?;
+    let sockaddr: SocketAddr = address
+        .to_socket_addrs()?
+        .next()
+        .ok_or_else(|| anyhow::anyhow!("no address found for {}", address))?;
+    let build_dir = book.build_dir_for("html");
+    let input_404 = book
+        .config
+        .get("output.html.input-404")
+        .map(toml::Value::as_str)
+        .and_then(std::convert::identity) // flatten
+        .map(ToString::to_string);
+    let file_404 = get_404_output_file(&input_404);
 
-    let ws_server =
-        ws::WebSocket::new(|_| |_| Ok(())).chain_err(|| "Unable to start the websocket")?;
+    // A channel used to broadcast to any websockets to reload when a file changes.
+    let (tx, _rx) = tokio::sync::broadcast::channel::<Message>(100);
 
-    let broadcaster = ws_server.broadcaster();
-
-    std::thread::spawn(move || {
-        ws_server.listen(&*ws_address).unwrap();
+    let reload_tx = tx.clone();
+    let thread_handle = std::thread::spawn(move || {
+        serve(build_dir, sockaddr, reload_tx, &file_404);
     });
 
     let serving_url = format!("http://{}", address);
@@ -114,36 +105,61 @@ pub fn execute(args: &ArgMatches) -> Result<()> {
     }
 
     #[cfg(feature = "watch")]
-    watch::trigger_on_change(&mut book, move |path, book_dir| {
-        info!("File changed: {:?}", path);
+    watch::trigger_on_change(&book, move |paths, book_dir| {
+        info!("Files changed: {:?}", paths);
         info!("Building book...");
 
         // FIXME: This area is really ugly because we need to re-set livereload :(
-
-        let result = MDBook::load(&book_dir)
-            .and_then(|mut b| {
-                b.config
-                    .set("output.html.livereload-url", &livereload_url)?;
-                Ok(b)
-            }).and_then(|b| b.build());
+        let result = MDBook::load(&book_dir).and_then(|mut b| {
+            update_config(&mut b);
+            b.build()
+        });
 
         if let Err(e) = result {
             error!("Unable to load the book");
             utils::log_backtrace(&e);
         } else {
-            let _ = broadcaster.send("reload");
+            let _ = tx.send(Message::text("reload"));
         }
     });
 
+    let _ = thread_handle.join();
+
     Ok(())
 }
 
-impl AfterMiddleware for ErrorRecover {
-    fn catch(&self, _: &mut Request, err: IronError) -> IronResult<Response> {
-        match err.response.status {
-            // each error will result in 404 response
-            Some(_) => Ok(err.response.set(status::NotFound)),
-            _ => Err(err),
-        }
-    }
+#[tokio::main]
+async fn serve(
+    build_dir: PathBuf,
+    address: SocketAddr,
+    reload_tx: broadcast::Sender<Message>,
+    file_404: &str,
+) {
+    // A warp Filter which captures `reload_tx` and provides an `rx` copy to
+    // receive reload messages.
+    let sender = warp::any().map(move || reload_tx.subscribe());
+
+    // A warp Filter to handle the livereload endpoint. This upgrades to a
+    // websocket, and then waits for any filesystem change notifications, and
+    // relays them over the websocket.
+    let livereload = warp::path(LIVE_RELOAD_ENDPOINT)
+        .and(warp::ws())
+        .and(sender)
+        .map(|ws: warp::ws::Ws, mut rx: broadcast::Receiver<Message>| {
+            ws.on_upgrade(move |ws| async move {
+                let (mut user_ws_tx, _user_ws_rx) = ws.split();
+                trace!("websocket got connection");
+                if let Ok(m) = rx.recv().await {
+                    trace!("notify of reload");
+                    let _ = user_ws_tx.send(m).await;
+                }
+            })
+        });
+    // A warp Filter that serves from the filesystem.
+    let book_route = warp::fs::dir(build_dir.clone());
+    // The fallback route for 404 errors
+    let fallback_route = warp::fs::file(build_dir.join(file_404))
+        .map(|reply| warp::reply::with_status(reply, warp::http::StatusCode::NOT_FOUND));
+    let routes = livereload.or(book_route).or(fallback_route);
+    warp::serve(routes).run(address).await;
 }

src/cmd/test.rs

@@ -1,5 +1,5 @@
+use crate::get_book_dir;
 use clap::{App, Arg, ArgMatches, SubCommand};
-use get_book_dir;
 use mdbook::errors::Result;
 use mdbook::MDBook;
 
@@ -9,7 +9,8 @@ pub fn make_subcommand<'a, 'b>() -> App<'a, 'b> {
         .about("Tests that a book's Rust code samples compile")
         .arg_from_usage(
             "-d, --dest-dir=[dest-dir] 'Output directory for the book{n}\
-             (If omitted, uses build.build-dir from book.toml or defaults to ./book)'",
+             Relative paths are interpreted relative to the book's root directory.{n}\
+             If omitted, mdBook uses build.build-dir from book.toml or defaults to `./book`.'",
         )
         .arg_from_usage(
             "[dir] 'Root directory for the book{n}\
@@ -30,7 +31,7 @@ pub fn make_subcommand<'a, 'b>() -> App<'a, 'b> {
 pub fn execute(args: &ArgMatches) -> Result<()> {
     let library_paths: Vec<&str> = args
         .values_of("library-path")
-        .map(|v| v.collect())
+        .map(std::iter::Iterator::collect)
         .unwrap_or_default();
     let book_dir = get_book_dir(args);
     let mut book = MDBook::load(&book_dir)?;

src/cmd/watch.rs

@@ -1,14 +1,13 @@
-extern crate notify;
-
-use self::notify::Watcher;
+use crate::{get_book_dir, open};
 use clap::{App, ArgMatches, SubCommand};
 use mdbook::errors::Result;
 use mdbook::utils;
 use mdbook::MDBook;
-use std::path::Path;
+use notify::Watcher;
+use std::path::{Path, PathBuf};
 use std::sync::mpsc::channel;
+use std::thread::sleep;
 use std::time::Duration;
-use {get_book_dir, open};
 
 // Create clap subcommand arguments
 pub fn make_subcommand<'a, 'b>() -> App<'a, 'b> {
@@ -16,26 +15,39 @@ pub fn make_subcommand<'a, 'b>() -> App<'a, 'b> {
         .about("Watches a book's files and rebuilds it on changes")
         .arg_from_usage(
             "-d, --dest-dir=[dest-dir] 'Output directory for the book{n}\
-             (If omitted, uses build.build-dir from book.toml or defaults to ./book)'",
-        ).arg_from_usage(
+             Relative paths are interpreted relative to the book's root directory.{n}\
+             If omitted, mdBook uses build.build-dir from book.toml or defaults to `./book`.'",
+        )
+        .arg_from_usage(
             "[dir] 'Root directory for the book{n}\
              (Defaults to the Current Directory when omitted)'",
-        ).arg_from_usage("-o, --open 'Open the compiled book in a web browser'")
+        )
+        .arg_from_usage("-o, --open 'Open the compiled book in a web browser'")
 }
 
 // Watch command implementation
 pub fn execute(args: &ArgMatches) -> Result<()> {
     let book_dir = get_book_dir(args);
-    let book = MDBook::load(&book_dir)?;
+    let mut book = MDBook::load(&book_dir)?;
+
+    let update_config = |book: &mut MDBook| {
+        if let Some(dest_dir) = args.value_of("dest-dir") {
+            book.config.build.build_dir = dest_dir.into();
+        }
+    };
+    update_config(&mut book);
 
     if args.is_present("open") {
         book.build()?;
         open(book.build_dir_for("html").join("index.html"));
     }
 
-    trigger_on_change(&book, |path, book_dir| {
-        info!("File changed: {:?}\nBuilding book...\n", path);
-        let result = MDBook::load(&book_dir).and_then(|b| b.build());
+    trigger_on_change(&book, |paths, book_dir| {
+        info!("Files changed: {:?}\nBuilding book...\n", paths);
+        let result = MDBook::load(&book_dir).and_then(|mut b| {
+            update_config(&mut b);
+            b.build()
+        });
 
         if let Err(e) = result {
             error!("Unable to build the book");
@@ -46,13 +58,60 @@ pub fn execute(args: &ArgMatches) -> Result<()> {
     Ok(())
 }
 
+fn remove_ignored_files(book_root: &PathBuf, paths: &[PathBuf]) -> Vec<PathBuf> {
+    if paths.is_empty() {
+        return vec![];
+    }
+
+    match find_gitignore(book_root) {
+        Some(gitignore_path) => {
+            match gitignore::File::new(gitignore_path.as_path()) {
+                Ok(exclusion_checker) => filter_ignored_files(exclusion_checker, paths),
+                Err(_) => {
+                    // We're unable to read the .gitignore file, so we'll silently allow everything.
+                    // Please see discussion: https://github.com/rust-lang/mdBook/pull/1051
+                    paths.iter().map(|path| path.to_path_buf()).collect()
+                }
+            }
+        }
+        None => {
+            // There is no .gitignore file.
+            paths.iter().map(|path| path.to_path_buf()).collect()
+        }
+    }
+}
+
+fn find_gitignore(book_root: &PathBuf) -> Option<PathBuf> {
+    book_root
+        .ancestors()
+        .map(|p| p.join(".gitignore"))
+        .find(|p| p.exists())
+}
+
+fn filter_ignored_files(exclusion_checker: gitignore::File, paths: &[PathBuf]) -> Vec<PathBuf> {
+    paths
+        .iter()
+        .filter(|path| match exclusion_checker.is_excluded(path) {
+            Ok(exclude) => !exclude,
+            Err(error) => {
+                warn!(
+                    "Unable to determine if {:?} is excluded: {:?}. Including it.",
+                    &path, error
+                );
+                true
+            }
+        })
+        .map(|path| path.to_path_buf())
+        .collect()
+}
+
 /// Calls the closure when a book source file is changed, blocking indefinitely.
 pub fn trigger_on_change<F>(book: &MDBook, closure: F)
 where
-    F: Fn(&Path, &Path),
+    F: Fn(Vec<PathBuf>, &Path),
 {
-    use self::notify::DebouncedEvent::*;
-    use self::notify::RecursiveMode::*;
+    use notify::DebouncedEvent::*;
+    use notify::RecursiveMode::*;
 
     // Create a channel to receive the events.
     let (tx, rx) = channel();
@@ -61,14 +120,14 @@ where
         Ok(w) => w,
         Err(e) => {
             error!("Error while trying to watch the files:\n\n\t{:?}", e);
-            ::std::process::exit(1)
+            std::process::exit(1)
         }
     };
 
     // Add the source directory to the watcher
     if let Err(e) = watcher.watch(book.source_dir(), Recursive) {
         error!("Error while watching {:?}:\n    {:?}", book.source_dir(), e);
-        ::std::process::exit(1);
+        std::process::exit(1);
     };
 
     let _ = watcher.watch(book.theme_dir(), Recursive);
@@ -78,13 +137,28 @@ where
 
     info!("Listening for changes...");
 
-    for event in rx.iter() {
-        debug!("Received filesystem event: {:?}", event);
-        match event {
-            Create(path) | Write(path) | Remove(path) | Rename(_, path) => {
-                closure(&path, &book.root);
-            }
-            _ => {}
+    loop {
+        let first_event = rx.recv().unwrap();
+        sleep(Duration::from_millis(50));
+        let other_events = rx.try_iter();
+
+        let all_events = std::iter::once(first_event).chain(other_events);
+
+        let paths = all_events
+            .filter_map(|event| {
+                debug!("Received filesystem event: {:?}", event);
+
+                match event {
+                    Create(path) | Write(path) | Remove(path) | Rename(_, path) => Some(path),
+                    _ => None,
+                }
+            })
+            .collect::<Vec<_>>();
+
+        let paths = remove_ignored_files(&book.root, &paths[..]);
+
+        if !paths.is_empty() {
+            closure(paths, &book.root);
         }
     }
 }

src/config.rs

@@ -3,16 +3,15 @@
 //! The main entrypoint of the `config` module is the `Config` struct. This acts
 //! essentially as a bag of configuration information, with a couple
 //! pre-determined tables (`BookConfig` and `BuildConfig`) as well as support
-//! for arbitrary data which is exposed to plugins and alternate backends.
+//! for arbitrary data which is exposed to plugins and alternative backends.
 //!
 //!
 //! # Examples
 //!
 //! ```rust
-//! # extern crate mdbook;
 //! # use mdbook::errors::*;
-//! # extern crate toml;
 //! use std::path::PathBuf;
+//! use std::str::FromStr;
 //! use mdbook::Config;
 //! use toml::Value;
 //!
@@ -41,28 +40,27 @@
 //! cfg.set("output.html.theme", "./themes");
 //!
 //! // then load it again, automatically deserializing to a `PathBuf`.
-//! let got: PathBuf = cfg.get_deserialized("output.html.theme")?;
-//! assert_eq!(got, PathBuf::from("./themes"));
+//! let got: Option<PathBuf> = cfg.get_deserialized_opt("output.html.theme")?;
+//! assert_eq!(got, Some(PathBuf::from("./themes")));
 //! # Ok(())
 //! # }
-//! # fn main() { run().unwrap() }
+//! # run().unwrap()
 //! ```
 
 #![deny(missing_docs)]
 
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
-use serde_json;
+use std::collections::HashMap;
 use std::env;
 use std::fs::File;
 use std::io::Read;
 use std::path::{Path, PathBuf};
+use std::str::FromStr;
 use toml::value::Table;
 use toml::{self, Value};
-use toml_query::delete::TomlValueDeleteExt;
-use toml_query::insert::TomlValueInsertExt;
-use toml_query::read::TomlValueReadExt;
 
-use errors::*;
+use crate::errors::*;
+use crate::utils::{self, toml_ext::TomlExt};
 
 /// The overall configuration object for MDBook, essentially an in-memory
 /// representation of `book.toml`.
@@ -72,22 +70,28 @@ pub struct Config {
     pub book: BookConfig,
     /// Information about the build environment.
     pub build: BuildConfig,
+    /// Information about Rust language support.
+    pub rust: RustConfig,
     rest: Value,
 }
 
-impl Config {
-    /// Load a `Config` from some string.
-    pub fn from_str(src: &str) -> Result<Config> {
-        toml::from_str(src).chain_err(|| Error::from("Invalid configuration file"))
-    }
+impl FromStr for Config {
+    type Err = Error;
 
+    /// Load a `Config` from some string.
+    fn from_str(src: &str) -> Result<Self> {
+        toml::from_str(src).with_context(|| "Invalid configuration file")
+    }
+}
+
+impl Config {
     /// Load the configuration file from disk.
     pub fn from_disk<P: AsRef<Path>>(config_file: P) -> Result<Config> {
         let mut buffer = String::new();
         File::open(config_file)
-            .chain_err(|| "Unable to open the configuration file")?
+            .with_context(|| "Unable to open the configuration file")?
             .read_to_string(&mut buffer)
-            .chain_err(|| "Couldn't read the file")?;
+            .with_context(|| "Couldn't read the file")?;
 
         Config::from_str(&buffer)
     }
@@ -118,7 +122,7 @@ impl Config {
     /// > when building the book with something like
     /// >
     /// > ```text
-    /// > $ export MDBOOK_BOOK="{'title': 'My Awesome Book', authors: ['Michael-F-Bryan']}"
+    /// > $ export MDBOOK_BOOK='{"title": "My Awesome Book", "authors": ["Michael-F-Bryan"]}'
     /// > $ mdbook build
     /// > ```
     ///
@@ -128,16 +132,25 @@ impl Config {
     pub fn update_from_env(&mut self) {
         debug!("Updating the config from environment variables");
 
-        let overrides = env::vars().filter_map(|(key, value)| match parse_env(&key) {
-            Some(index) => Some((index, value)),
-            None => None,
-        });
+        let overrides =
+            env::vars().filter_map(|(key, value)| parse_env(&key).map(|index| (index, value)));
 
         for (key, value) in overrides {
             trace!("{} => {}", key, value);
             let parsed_value = serde_json::from_str(&value)
                 .unwrap_or_else(|_| serde_json::Value::String(value.to_string()));
 
+            if key == "book" || key == "build" {
+                if let serde_json::Value::Object(ref map) = parsed_value {
+                    // To `set` each `key`, we wrap them as `prefix.key`
+                    for (k, v) in map {
+                        let full_key = format!("{}.{}", key, k);
+                        self.set(&full_key, v).expect("unreachable");
+                    }
+                    return;
+                }
+            }
+
             self.set(key, parsed_value).expect("unreachable");
         }
     }
@@ -145,21 +158,15 @@ impl Config {
     /// Fetch an arbitrary item from the `Config` as a `toml::Value`.
     ///
     /// You can use dotted indices to access nested items (e.g.
-    /// `output.html.playpen` will fetch the "playpen" out of the html output
+    /// `output.html.playground` will fetch the "playground" out of the html output
     /// table).
     pub fn get(&self, key: &str) -> Option<&Value> {
-        match self.rest.read(key) {
-            Ok(inner) => inner,
-            Err(_) => None,
-        }
+        self.rest.read(key)
     }
 
     /// Fetch a value from the `Config` so you can mutate it.
-    pub fn get_mut<'a>(&'a mut self, key: &str) -> Option<&'a mut Value> {
-        match self.rest.read_mut(key) {
-            Ok(inner) => inner,
-            Err(_) => None,
-        }
+    pub fn get_mut(&mut self, key: &str) -> Option<&mut Value> {
+        self.rest.read_mut(key)
     }
 
     /// Convenience method for getting the html renderer's configuration.
@@ -170,22 +177,44 @@ impl Config {
     /// HTML renderer is refactored to be less coupled to `mdbook` internals.
     #[doc(hidden)]
     pub fn html_config(&self) -> Option<HtmlConfig> {
-        self.get_deserialized("output.html").ok()
+        match self
+            .get_deserialized_opt("output.html")
+            .with_context(|| "Parsing configuration [output.html]")
+        {
+            Ok(Some(config)) => Some(config),
+            Ok(None) => None,
+            Err(e) => {
+                utils::log_backtrace(&e);
+                None
+            }
+        }
+    }
+
+    /// Deprecated, use get_deserialized_opt instead.
+    #[deprecated = "use get_deserialized_opt instead"]
+    pub fn get_deserialized<'de, T: Deserialize<'de>, S: AsRef<str>>(&self, name: S) -> Result<T> {
+        let name = name.as_ref();
+        match self.get_deserialized_opt(name)? {
+            Some(value) => Ok(value),
+            None => bail!("Key not found, {:?}", name),
+        }
     }
 
     /// Convenience function to fetch a value from the config and deserialize it
     /// into some arbitrary type.
-    pub fn get_deserialized<'de, T: Deserialize<'de>, S: AsRef<str>>(&self, name: S) -> Result<T> {
+    pub fn get_deserialized_opt<'de, T: Deserialize<'de>, S: AsRef<str>>(
+        &self,
+        name: S,
+    ) -> Result<Option<T>> {
         let name = name.as_ref();
-
-        if let Some(value) = self.get(name) {
-            value
-                .clone()
-                .try_into()
-                .chain_err(|| "Couldn't deserialize the value")
-        } else {
-            bail!("Key not found, {:?}", name)
-        }
+        self.get(name)
+            .map(|value| {
+                value
+                    .clone()
+                    .try_into()
+                    .with_context(|| "Couldn't deserialize the value")
+            })
+            .transpose()
     }
 
     /// Set a config key, clobbering any existing values along the way.
@@ -195,15 +224,15 @@ impl Config {
     pub fn set<S: Serialize, I: AsRef<str>>(&mut self, index: I, value: S) -> Result<()> {
         let index = index.as_ref();
 
-        let value =
-            Value::try_from(value).chain_err(|| "Unable to represent the item as a JSON Value")?;
+        let value = Value::try_from(value)
+            .with_context(|| "Unable to represent the item as a JSON Value")?;
 
         if index.starts_with("book.") {
             self.book.update_value(&index[5..], value);
         } else if index.starts_with("build.") {
             self.build.update_value(&index[6..], value);
         } else {
-            self.rest.insert(index, value)?;
+            self.rest.insert(index, value);
         }
 
         Ok(())
@@ -212,13 +241,13 @@ impl Config {
     /// Get the table associated with a particular renderer.
     pub fn get_renderer<I: AsRef<str>>(&self, index: I) -> Option<&Table> {
         let key = format!("output.{}", index.as_ref());
-        self.get(&key).and_then(|v| v.as_table())
+        self.get(&key).and_then(Value::as_table)
     }
 
     /// Get the table associated with a particular preprocessor.
     pub fn get_preprocessor<I: AsRef<str>>(&self, index: I) -> Option<&Table> {
         let key = format!("preprocessor.{}", index.as_ref());
-        self.get(&key).and_then(|v| v.as_table())
+        self.get(&key).and_then(Value::as_table)
     }
 
     fn from_legacy(mut table: Value) -> Config {
@@ -244,7 +273,7 @@ impl Config {
         get_and_insert!(table, "source" => cfg.book.src);
         get_and_insert!(table, "description" => cfg.book.description);
 
-        if let Ok(Some(dest)) = table.delete("output.html.destination") {
+        if let Some(dest) = table.delete("output.html.destination") {
             if let Ok(destination) = dest.try_into() {
                 cfg.build.build_dir = destination;
             }
@@ -260,12 +289,13 @@ impl Default for Config {
         Config {
             book: BookConfig::default(),
             build: BuildConfig::default(),
+            rust: RustConfig::default(),
             rest: Value::Table(Table::default()),
         }
     }
 }
 impl<'de> Deserialize<'de> for Config {
-    fn deserialize<D: Deserializer<'de>>(de: D) -> ::std::result::Result<Self, D::Error> {
+    fn deserialize<D: Deserializer<'de>>(de: D) -> std::result::Result<Self, D::Error> {
         let raw = Value::deserialize(de)?;
 
         if is_legacy_format(&raw) {
@@ -276,7 +306,7 @@ impl<'de> Deserialize<'de> for Config {
             warn!("`description` under a table called `[book]`, move the `destination` entry");
             warn!("from `[output.html]`, renamed to `build-dir`, under a table called");
             warn!("`[build]`, and it should all work.");
-            warn!("Documentation: http://rust-lang-nursery.github.io/mdBook/format/config.html");
+            warn!("Documentation: http://rust-lang.github.io/mdBook/format/config.html");
             return Ok(Config::from_legacy(raw));
         }
 
@@ -300,28 +330,33 @@ impl<'de> Deserialize<'de> for Config {
             .and_then(|value| value.try_into().ok())
             .unwrap_or_default();
 
+        let rust: RustConfig = table
+            .remove("rust")
+            .and_then(|value| value.try_into().ok())
+            .unwrap_or_default();
+
         Ok(Config {
-            book: book,
-            build: build,
+            book,
+            build,
+            rust,
             rest: Value::Table(table),
         })
     }
 }
 
 impl Serialize for Config {
-    fn serialize<S: Serializer>(&self, s: S) -> ::std::result::Result<S::Ok, S::Error> {
-        use serde::ser::Error;
-
+    fn serialize<S: Serializer>(&self, s: S) -> std::result::Result<S::Ok, S::Error> {
+        // TODO: This should probably be removed and use a derive instead.
         let mut table = self.rest.clone();
 
-        let book_config = match Value::try_from(self.book.clone()) {
-            Ok(cfg) => cfg,
-            Err(_) => {
-                return Err(S::Error::custom("Unable to serialize the BookConfig"));
-            }
-        };
+        let book_config = Value::try_from(&self.book).expect("should always be serializable");
+        table.insert("book", book_config);
+
+        if self.rust != RustConfig::default() {
+            let rust_config = Value::try_from(&self.rust).expect("should always be serializable");
+            table.insert("rust", rust_config);
+        }
 
-        table.insert("book", book_config).expect("unreachable");
         table.serialize(s)
     }
 }
@@ -348,7 +383,7 @@ fn is_legacy_format(table: &Value) -> bool {
     ];
 
     for item in &legacy_items {
-        if let Ok(Some(_)) = table.read(item) {
+        if table.read(item).is_some() {
             return true;
         }
     }
@@ -371,6 +406,8 @@ pub struct BookConfig {
     pub src: PathBuf,
     /// Does this book support more than one language?
     pub multilingual: bool,
+    /// The main language of the book.
+    pub language: Option<String>,
 }
 
 impl Default for BookConfig {
@@ -381,6 +418,7 @@ impl Default for BookConfig {
             description: None,
             src: PathBuf::from("src"),
             multilingual: false,
+            language: Some(String::from("en")),
         }
     }
 }
@@ -391,7 +429,7 @@ impl Default for BookConfig {
 pub struct BuildConfig {
     /// Where to put built artefacts relative to the book's root directory.
     pub build_dir: PathBuf,
-    /// Should non-existent markdown files specified in `SETTINGS.md` be created
+    /// Should non-existent markdown files specified in `SUMMARY.md` be created
     /// if they don't exist?
     pub create_missing: bool,
     /// Should the default preprocessors always be used when they are
@@ -409,16 +447,42 @@ impl Default for BuildConfig {
     }
 }
 
+/// Configuration for the Rust compiler(e.g., for playground)
+#[derive(Debug, Default, Clone, PartialEq, Serialize, Deserialize)]
+#[serde(default, rename_all = "kebab-case")]
+pub struct RustConfig {
+    /// Rust edition used in playground
+    pub edition: Option<RustEdition>,
+}
+
+#[derive(Debug, Copy, Clone, PartialEq, Serialize, Deserialize)]
+/// Rust edition to use for the code.
+pub enum RustEdition {
+    /// The 2018 edition of Rust
+    #[serde(rename = "2018")]
+    E2018,
+    /// The 2015 edition of Rust
+    #[serde(rename = "2015")]
+    E2015,
+}
+
 /// Configuration for the HTML renderer.
-#[derive(Debug, Clone, Default, PartialEq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 #[serde(default, rename_all = "kebab-case")]
 pub struct HtmlConfig {
     /// The theme directory, if specified.
     pub theme: Option<PathBuf>,
+    /// The default theme to use, defaults to 'light'
+    pub default_theme: Option<String>,
+    /// The theme to use if the browser requests the dark version of the site.
+    /// Defaults to 'navy'.
+    pub preferred_dark_theme: Option<String>,
     /// Use "smart quotes" instead of the usual `"` character.
     pub curly_quotes: bool,
     /// Should mathjax be enabled?
     pub mathjax_support: bool,
+    /// Whether to fonts.css and respective font files to the output directory.
+    pub copy_fonts: bool,
     /// An optional google analytics code.
     pub google_analytics: Option<String>,
     /// Additional CSS stylesheets to include in the rendered page's `<head>`.
@@ -426,8 +490,24 @@ pub struct HtmlConfig {
     /// Additional JS scripts to include at the bottom of the rendered page's
     /// `<body>`.
     pub additional_js: Vec<PathBuf>,
-    /// Playpen settings.
-    pub playpen: Playpen,
+    /// Fold settings.
+    pub fold: Fold,
+    /// Playground settings.
+    #[serde(alias = "playpen")]
+    pub playground: Playground,
+    /// Don't render section labels.
+    pub no_section_label: bool,
+    /// Search settings. If `None`, the default will be used.
+    pub search: Option<Search>,
+    /// Git repository url. If `None`, the git button will not be shown.
+    pub git_repository_url: Option<String>,
+    /// FontAwesome icon class to use for the Git repository link.
+    /// Defaults to `fa-github` if `None`.
+    pub git_repository_icon: Option<String>,
+    /// Input path for the 404 file, defaults to 404.md, set to "" to disable 404 file output
+    pub input_404: Option<String>,
+    /// Absolute url to site, used to emit correct paths for the 404 page, which might be accessed in a deeply nested directory
+    pub site_url: Option<String>,
     /// This is used as a bit of a workaround for the `mdbook serve` command.
     /// Basically, because you set the websocket port from the command line, the
     /// `mdbook serve` command needs a way to let the HTML renderer know where
@@ -436,10 +516,35 @@ pub struct HtmlConfig {
     /// This config item *should not be edited* by the end user.
     #[doc(hidden)]
     pub livereload_url: Option<String>,
-    /// Should section labels be rendered?
-    pub no_section_label: bool,
-    /// Search settings. If `None`, the default will be used.
-    pub search: Option<Search>,
+    /// The mapping from old pages to new pages/URLs to use when generating
+    /// redirects.
+    pub redirect: HashMap<String, String>,
+}
+
+impl Default for HtmlConfig {
+    fn default() -> HtmlConfig {
+        HtmlConfig {
+            theme: None,
+            default_theme: None,
+            preferred_dark_theme: None,
+            curly_quotes: false,
+            mathjax_support: false,
+            copy_fonts: true,
+            google_analytics: None,
+            additional_css: Vec::new(),
+            additional_js: Vec::new(),
+            fold: Fold::default(),
+            playground: Playground::default(),
+            no_section_label: false,
+            search: None,
+            git_repository_url: None,
+            git_repository_icon: None,
+            input_404: None,
+            site_url: None,
+            livereload_url: None,
+            redirect: HashMap::new(),
+        }
+    }
 }
 
 impl HtmlConfig {
@@ -453,22 +558,40 @@ impl HtmlConfig {
     }
 }
 
-/// Configuration for tweaking how the the HTML renderer handles the playpen.
+/// Configuration for how to fold chapters of sidebar.
+#[derive(Default, Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[serde(default, rename_all = "kebab-case")]
+pub struct Fold {
+    /// When off, all folds are open. Default: `false`.
+    pub enable: bool,
+    /// The higher the more folded regions are open. When level is 0, all folds
+    /// are closed.
+    /// Default: `0`.
+    pub level: u8,
+}
+
+/// Configuration for tweaking how the the HTML renderer handles the playground.
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 #[serde(default, rename_all = "kebab-case")]
-pub struct Playpen {
-    /// Should playpen snippets be editable? Default: `false`.
+pub struct Playground {
+    /// Should playground snippets be editable? Default: `false`.
     pub editable: bool,
+    /// Display the copy button. Default: `true`.
+    pub copyable: bool,
     /// Copy JavaScript files for the editor to the output directory?
     /// Default: `true`.
     pub copy_js: bool,
+    /// Display line numbers on playground snippets. Default: `false`.
+    pub line_numbers: bool,
 }
 
-impl Default for Playpen {
-    fn default() -> Playpen {
-        Playpen {
+impl Default for Playground {
+    fn default() -> Playground {
+        Playground {
             editable: false,
+            copyable: true,
             copy_js: true,
+            line_numbers: false,
         }
     }
 }
@@ -484,7 +607,7 @@ pub struct Search {
     /// The number of words used for a search result teaser. Default: `30`.
     pub teaser_word_count: u32,
     /// Define the logical link between multiple search words.
-    /// If true, all search words must appear in each result. Default: `true`.
+    /// If true, all search words must appear in each result. Default: `false`.
     pub use_boolean_and: bool,
     /// Boost factor for the search result score if a search word appears in the header.
     /// Default: `2`.
@@ -533,12 +656,10 @@ trait Updateable<'de>: Serialize + Deserialize<'de> {
     fn update_value<S: Serialize>(&mut self, key: &str, value: S) {
         let mut raw = Value::try_from(&self).expect("unreachable");
 
-        {
-            if let Ok(value) = Value::try_from(value) {
-                let _ = raw.insert(key, value);
-            } else {
-                return;
-            }
+        if let Ok(value) = Value::try_from(value) {
+            let _ = raw.insert(key, value);
+        } else {
+            return;
         }
 
         if let Ok(updated) = raw.try_into() {
@@ -552,14 +673,16 @@ impl<'de, T> Updateable<'de> for T where T: Serialize + Deserialize<'de> {}
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::utils::fs::get_404_output_file;
 
-    const COMPLEX_CONFIG: &'static str = r#"
+    const COMPLEX_CONFIG: &str = r#"
         [book]
         title = "Some Book"
         authors = ["Michael-F-Bryan <michaelfbryan@gmail.com>"]
         description = "A completely useless book"
         multilingual = true
         src = "source"
+        language = "ja"
 
         [build]
         build-dir = "outputs"
@@ -568,17 +691,24 @@ mod tests {
 
         [output.html]
         theme = "./themedir"
+        default-theme = "rust"
         curly-quotes = true
         google-analytics = "123456"
         additional-css = ["./foo/bar/baz.css"]
+        git-repository-url = "https://foo.com/"
+        git-repository-icon = "fa-code-fork"
 
-        [output.html.playpen]
+        [output.html.playground]
         editable = true
         editor = "ace"
 
-        [preprocess.first]
+        [output.html.redirect]
+        "index.html" = "overview.html"
+        "nexted/page.md" = "https://rust-lang.org/"
 
-        [preprocess.second]
+        [preprocessor.first]
+
+        [preprocessor.second]
         "#;
 
     #[test]
@@ -591,23 +721,38 @@ mod tests {
             description: Some(String::from("A completely useless book")),
             multilingual: true,
             src: PathBuf::from("source"),
-            ..Default::default()
+            language: Some(String::from("ja")),
         };
         let build_should_be = BuildConfig {
             build_dir: PathBuf::from("outputs"),
             create_missing: false,
             use_default_preprocessors: true,
         };
-        let playpen_should_be = Playpen {
+        let rust_should_be = RustConfig { edition: None };
+        let playground_should_be = Playground {
             editable: true,
+            copyable: true,
             copy_js: true,
+            line_numbers: false,
         };
         let html_should_be = HtmlConfig {
             curly_quotes: true,
             google_analytics: Some(String::from("123456")),
             additional_css: vec![PathBuf::from("./foo/bar/baz.css")],
             theme: Some(PathBuf::from("./themedir")),
-            playpen: playpen_should_be,
+            default_theme: Some(String::from("rust")),
+            playground: playground_should_be,
+            git_repository_url: Some(String::from("https://foo.com/")),
+            git_repository_icon: Some(String::from("fa-code-fork")),
+            redirect: vec![
+                (String::from("index.html"), String::from("overview.html")),
+                (
+                    String::from("nexted/page.md"),
+                    String::from("https://rust-lang.org/"),
+                ),
+            ]
+            .into_iter()
+            .collect(),
             ..Default::default()
         };
 
@@ -615,9 +760,62 @@ mod tests {
 
         assert_eq!(got.book, book_should_be);
         assert_eq!(got.build, build_should_be);
+        assert_eq!(got.rust, rust_should_be);
         assert_eq!(got.html_config().unwrap(), html_should_be);
     }
 
+    #[test]
+    fn edition_2015() {
+        let src = r#"
+        [book]
+        title = "mdBook Documentation"
+        description = "Create book from markdown files. Like Gitbook but implemented in Rust"
+        authors = ["Mathieu David"]
+        src = "./source"
+        [rust]
+        edition = "2015"
+        "#;
+
+        let book_should_be = BookConfig {
+            title: Some(String::from("mdBook Documentation")),
+            description: Some(String::from(
+                "Create book from markdown files. Like Gitbook but implemented in Rust",
+            )),
+            authors: vec![String::from("Mathieu David")],
+            src: PathBuf::from("./source"),
+            ..Default::default()
+        };
+
+        let got = Config::from_str(src).unwrap();
+        assert_eq!(got.book, book_should_be);
+
+        let rust_should_be = RustConfig {
+            edition: Some(RustEdition::E2015),
+        };
+        let got = Config::from_str(src).unwrap();
+        assert_eq!(got.rust, rust_should_be);
+    }
+
+    #[test]
+    fn edition_2018() {
+        let src = r#"
+        [book]
+        title = "mdBook Documentation"
+        description = "Create book from markdown files. Like Gitbook but implemented in Rust"
+        authors = ["Mathieu David"]
+        src = "./source"
+        [rust]
+        edition = "2018"
+        "#;
+
+        let rust_should_be = RustConfig {
+            edition: Some(RustEdition::E2018),
+        };
+
+        let got = Config::from_str(src).unwrap();
+        assert_eq!(got.rust, rust_should_be);
+    }
+
     #[test]
     fn load_arbitrary_output_type() {
         #[derive(Debug, Deserialize, PartialEq)]
@@ -641,14 +839,17 @@ mod tests {
         };
 
         let cfg = Config::from_str(src).unwrap();
-        let got: RandomOutput = cfg.get_deserialized("output.random").unwrap();
+        let got: RandomOutput = cfg.get_deserialized_opt("output.random").unwrap().unwrap();
 
         assert_eq!(got, should_be);
 
-        let baz: Vec<bool> = cfg.get_deserialized("output.random.baz").unwrap();
+        let got_baz: Vec<bool> = cfg
+            .get_deserialized_opt("output.random.baz")
+            .unwrap()
+            .unwrap();
         let baz_should_be = vec![true, true, false];
 
-        assert_eq!(baz, baz_should_be);
+        assert_eq!(got_baz, baz_should_be);
     }
 
     #[test]
@@ -657,7 +858,7 @@ mod tests {
         // is happy...
         let src = COMPLEX_CONFIG;
         let mut config = Config::from_str(src).unwrap();
-        let key = "output.html.playpen.editable";
+        let key = "output.html.playground.editable";
 
         assert_eq!(config.get(key).unwrap(), &Value::Boolean(true));
         *config.get_mut(key).unwrap() = Value::Boolean(false);
@@ -725,7 +926,7 @@ mod tests {
         assert!(cfg.get(key).is_none());
         cfg.set(key, value).unwrap();
 
-        let got: String = cfg.get_deserialized(key).unwrap();
+        let got: String = cfg.get_deserialized_opt(key).unwrap().unwrap();
         assert_eq!(got, value);
     }
 
@@ -740,7 +941,7 @@ mod tests {
 
         for (src, should_be) in inputs {
             let got = parse_env(src);
-            let should_be = should_be.map(|s| s.to_string());
+            let should_be = should_be.map(ToString::to_string);
 
             assert_eq!(got, should_be);
         }
@@ -766,10 +967,14 @@ mod tests {
 
         cfg.update_from_env();
 
-        assert_eq!(cfg.get_deserialized::<String, _>(key).unwrap(), value);
+        assert_eq!(
+            cfg.get_deserialized_opt::<String, _>(key).unwrap().unwrap(),
+            value
+        );
     }
 
     #[test]
+    #[allow(clippy::approx_constant)]
     fn update_config_using_env_var_and_complex_value() {
         let mut cfg = Config::default();
         let key = "foo-bar.baz";
@@ -784,7 +989,9 @@ mod tests {
         cfg.update_from_env();
 
         assert_eq!(
-            cfg.get_deserialized::<serde_json::Value, _>(key).unwrap(),
+            cfg.get_deserialized_opt::<serde_json::Value, _>(key)
+                .unwrap()
+                .unwrap(),
             value
         );
     }
@@ -801,4 +1008,31 @@ mod tests {
 
         assert_eq!(cfg.book.title, Some(should_be));
     }
+
+    #[test]
+    fn file_404_default() {
+        let src = r#"
+        [output.html]
+        destination = "my-book"
+        "#;
+
+        let got = Config::from_str(src).unwrap();
+        let html_config = got.html_config().unwrap();
+        assert_eq!(html_config.input_404, None);
+        assert_eq!(&get_404_output_file(&html_config.input_404), "404.html");
+    }
+
+    #[test]
+    fn file_404_custom() {
+        let src = r#"
+        [output.html]
+        input-404= "missing.md"
+        output-404= "missing.html"
+        "#;
+
+        let got = Config::from_str(src).unwrap();
+        let html_config = got.html_config().unwrap();
+        assert_eq!(html_config.input_404, Some("missing.md".to_string()));
+        assert_eq!(&get_404_output_file(&html_config.input_404), "missing.html");
+    }
 }

src/lib.rs

@@ -75,33 +75,23 @@
 //! directly, making deserializing the `RenderContext` easy and giving you
 //! access to the various methods for working with the [`Config`].
 //!
-//! [user guide]: https://rust-lang-nursery.github.io/mdBook/
+//! [user guide]: https://rust-lang.github.io/mdBook/
 //! [`RenderContext`]: renderer/struct.RenderContext.html
-//! [relevant chapter]: https://rust-lang-nursery.github.io/mdBook/for_developers/backends.html
+//! [relevant chapter]: https://rust-lang.github.io/mdBook/for_developers/backends.html
 //! [`Config`]: config/struct.Config.html
 
 #![deny(missing_docs)]
+#![deny(rust_2018_idioms)]
+#![allow(clippy::comparison_chain)]
 
-#[macro_use]
-extern crate error_chain;
-extern crate handlebars;
-extern crate itertools;
 #[macro_use]
 extern crate lazy_static;
 #[macro_use]
 extern crate log;
-extern crate memchr;
-extern crate pulldown_cmark;
-extern crate regex;
-extern crate serde;
 #[macro_use]
 extern crate serde_derive;
 #[macro_use]
 extern crate serde_json;
-extern crate shlex;
-extern crate tempfile;
-extern crate toml;
-extern crate toml_query;
 
 #[cfg(test)]
 #[macro_use]
@@ -120,53 +110,13 @@ pub mod utils;
 /// compatibility checks.
 pub const MDBOOK_VERSION: &str = env!("CARGO_PKG_VERSION");
 
-pub use book::BookItem;
-pub use book::MDBook;
-pub use config::Config;
-pub use renderer::Renderer;
+pub use crate::book::BookItem;
+pub use crate::book::MDBook;
+pub use crate::config::Config;
+pub use crate::renderer::Renderer;
 
 /// The error types used through out this crate.
 pub mod errors {
-    use std::path::PathBuf;
-
-    error_chain!{
-        foreign_links {
-            Io(::std::io::Error) #[doc = "A wrapper around `std::io::Error`"];
-            HandlebarsRender(::handlebars::RenderError) #[doc = "Handlebars rendering failed"];
-            HandlebarsTemplate(Box<::handlebars::TemplateError>) #[doc = "Unable to parse the template"];
-            Utf8(::std::string::FromUtf8Error) #[doc = "Invalid UTF-8"];
-            SerdeJson(::serde_json::Error) #[doc = "JSON conversion failed"];
-        }
-
-        links {
-            TomlQuery(::toml_query::error::Error, ::toml_query::error::ErrorKind) #[doc = "A TomlQuery error"];
-        }
-
-        errors {
-            /// A subprocess exited with an unsuccessful return code.
-            Subprocess(message: String, output: ::std::process::Output) {
-                description("A subprocess failed")
-                display("{}: {}", message, String::from_utf8_lossy(&output.stdout))
-            }
-
-            /// An error was encountered while parsing the `SUMMARY.md` file.
-            ParseError(line: usize, col: usize, message: String) {
-                description("A SUMMARY.md parsing error")
-                display("Error at line {}, column {}: {}", line, col, message)
-            }
-
-            /// The user tried to use a reserved filename.
-            ReservedFilenameError(filename: PathBuf) {
-                description("Reserved Filename")
-                display("{} is reserved for internal use", filename.display())
-            }
-        }
-    }
-
-    // Box to halve the size of Error
-    impl From<::handlebars::TemplateError> for Error {
-        fn from(e: ::handlebars::TemplateError) -> Error {
-            From::from(Box::new(e))
-        }
-    }
+    pub(crate) use anyhow::{bail, ensure, Context};
+    pub use anyhow::{Error, Result};
 }

src/main.rs

@@ -1,12 +1,7 @@
-extern crate chrono;
 #[macro_use]
 extern crate clap;
-extern crate env_logger;
-extern crate error_chain;
 #[macro_use]
 extern crate log;
-extern crate mdbook;
-extern crate open;
 
 use chrono::Local;
 use clap::{App, AppSettings, ArgMatches};
@@ -20,22 +15,22 @@ use std::path::{Path, PathBuf};
 
 mod cmd;
 
-const NAME: &'static str = "mdBook";
-const VERSION: &'static str = concat!("v", crate_version!());
+const VERSION: &str = concat!("v", crate_version!());
 
 fn main() {
     init_logger();
 
     // Create a list of valid arguments and sub-commands
-    let app = App::new(NAME)
-        .about("Creates a book from markdown files")
+    let app = App::new(crate_name!())
+        .about(crate_description!())
         .author("Mathieu David <mathieudavid@mathieudavid.org>")
         .version(VERSION)
         .setting(AppSettings::GlobalVersion)
         .setting(AppSettings::ArgRequiredElseHelp)
+        .setting(AppSettings::ColoredHelp)
         .after_help(
             "For more information about a specific command, try `mdbook <command> --help`\n\
-             The source code for mdBook is available at: https://github.com/rust-lang-nursery/mdBook",
+             The source code for mdBook is available at: https://github.com/rust-lang/mdBook",
         )
         .subcommand(cmd::init::make_subcommand())
         .subcommand(cmd::build::make_subcommand())
@@ -63,7 +58,7 @@ fn main() {
     if let Err(e) = res {
         utils::log_backtrace(&e);
 
-        ::std::process::exit(101);
+        std::process::exit(101);
     }
 }
 
@@ -82,7 +77,7 @@ fn init_logger() {
     });
 
     if let Ok(var) = env::var("RUST_LOG") {
-        builder.parse(&var);
+        builder.parse_filters(&var);
     } else {
         // if no RUST_LOG provided, default to logging at the Info level
         builder.filter(None, LevelFilter::Info);

src/preprocess/cmd.rs

@@ -1,7 +1,6 @@
 use super::{Preprocessor, PreprocessorContext};
-use book::Book;
-use errors::*;
-use serde_json;
+use crate::book::Book;
+use crate::errors::*;
 use shlex::Shlex;
 use std::io::{self, Read, Write};
 use std::process::{Child, Command, Stdio};
@@ -43,19 +42,11 @@ impl CmdPreprocessor {
 
     /// A convenience function custom preprocessors can use to parse the input
     /// written to `stdin` by a `CmdRenderer`.
-    pub fn parse_input<R: Read>(
-        reader: R,
-    ) -> Result<(PreprocessorContext, Book)> {
-        serde_json::from_reader(reader)
-            .chain_err(|| "Unable to parse the input")
+    pub fn parse_input<R: Read>(reader: R) -> Result<(PreprocessorContext, Book)> {
+        serde_json::from_reader(reader).with_context(|| "Unable to parse the input")
     }
 
-    fn write_input_to_child(
-        &self,
-        child: &mut Child,
-        book: &Book,
-        ctx: &PreprocessorContext,
-    ) {
+    fn write_input_to_child(&self, child: &mut Child, book: &Book, ctx: &PreprocessorContext) {
         let stdin = child.stdin.take().expect("Child has stdin");
 
         if let Err(e) = self.write_input(stdin, &book, &ctx) {
@@ -65,9 +56,13 @@ impl CmdPreprocessor {
         }
     }
 
-    fn write_input<W: Write>(&self, writer: W, book: &Book, ctx: &PreprocessorContext) -> Result<()> {
-        serde_json::to_writer(writer, &(ctx, book))
-            .map_err(Into::into)
+    fn write_input<W: Write>(
+        &self,
+        writer: W,
+        book: &Book,
+        ctx: &PreprocessorContext,
+    ) -> Result<()> {
+        serde_json::to_writer(writer, &(ctx, book)).map_err(Into::into)
     }
 
     /// The command this `Preprocessor` will invoke.
@@ -105,27 +100,44 @@ impl Preprocessor for CmdPreprocessor {
             .stdout(Stdio::piped())
             .stderr(Stdio::inherit())
             .spawn()
-            .chain_err(|| format!("Unable to start the \"{}\" preprocessor. Is it installed?", self.name()))?;
+            .with_context(|| {
+                format!(
+                    "Unable to start the \"{}\" preprocessor. Is it installed?",
+                    self.name()
+                )
+            })?;
 
         self.write_input_to_child(&mut child, &book, ctx);
 
         let output = child
             .wait_with_output()
-            .chain_err(|| "Error waiting for the preprocessor to complete")?;
+            .with_context(|| "Error waiting for the preprocessor to complete")?;
 
         trace!("{} exited with output: {:?}", self.cmd, output);
-        ensure!(output.status.success(), "The preprocessor exited unsuccessfully");
+        ensure!(
+            output.status.success(),
+            "The preprocessor exited unsuccessfully"
+        );
 
-        serde_json::from_slice(&output.stdout).chain_err(|| "Unable to parse the preprocessed book")
+        serde_json::from_slice(&output.stdout)
+            .with_context(|| "Unable to parse the preprocessed book")
     }
 
     fn supports_renderer(&self, renderer: &str) -> bool {
-        debug!("Checking if the \"{}\" preprocessor supports \"{}\"", self.name(), renderer);
+        debug!(
+            "Checking if the \"{}\" preprocessor supports \"{}\"",
+            self.name(),
+            renderer
+        );
 
         let mut cmd = match self.command() {
             Ok(c) => c,
             Err(e) => {
-                warn!("Unable to create the command for the \"{}\" preprocessor, {}", self.name(), e);
+                warn!(
+                    "Unable to create the command for the \"{}\" preprocessor, {}",
+                    self.name(),
+                    e
+                );
                 return false;
             }
         };
@@ -152,3 +164,34 @@ impl Preprocessor for CmdPreprocessor {
         outcome.unwrap_or(false)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::MDBook;
+    use std::path::Path;
+
+    fn book_example() -> MDBook {
+        let example = Path::new(env!("CARGO_MANIFEST_DIR")).join("book-example");
+        MDBook::load(example).unwrap()
+    }
+
+    #[test]
+    fn round_trip_write_and_parse_input() {
+        let cmd = CmdPreprocessor::new("test".to_string(), "test".to_string());
+        let md = book_example();
+        let ctx = PreprocessorContext::new(
+            md.root.clone(),
+            md.config.clone(),
+            "some-renderer".to_string(),
+        );
+
+        let mut buffer = Vec::new();
+        cmd.write_input(&mut buffer, &md.book, &ctx).unwrap();
+
+        let (got_ctx, got_book) = CmdPreprocessor::parse_input(buffer.as_slice()).unwrap();
+
+        assert_eq!(got_book, md.book);
+        assert_eq!(got_ctx, ctx);
+    }
+}

src/preprocess/index.rs

@@ -1,13 +1,14 @@
 use regex::Regex;
 use std::path::Path;
 
-use errors::*;
+use crate::errors::*;
 
 use super::{Preprocessor, PreprocessorContext};
-use book::{Book, BookItem};
+use crate::book::{Book, BookItem};
 
 /// A preprocessor for converting file name `README.md` to `index.md` since
-/// `README.md` is the de facto index file in a markdown-based documentation.
+/// `README.md` is the de facto index file in markdown-based documentation.
+#[derive(Default)]
 pub struct IndexPreprocessor;
 
 impl IndexPreprocessor {
@@ -28,13 +29,15 @@ impl Preprocessor for IndexPreprocessor {
         let source_dir = ctx.root.join(&ctx.config.book.src);
         book.for_each_mut(|section: &mut BookItem| {
             if let BookItem::Chapter(ref mut ch) = *section {
-                if is_readme_file(&ch.path) {
-                    let index_md = source_dir.join(ch.path.with_file_name("index.md"));
-                    if index_md.exists() {
-                        warn_readme_name_conflict(&ch.path, &index_md);
-                    }
+                if let Some(ref mut path) = ch.path {
+                    if is_readme_file(&path) {
+                        let mut index_md = source_dir.join(path.with_file_name("index.md"));
+                        if index_md.exists() {
+                            warn_readme_name_conflict(&path, &&mut index_md);
+                        }
 
-                    ch.path.set_file_name("index.md");
+                        path.set_file_name("index.md");
+                    }
                 }
             }
         });
@@ -45,7 +48,10 @@ impl Preprocessor for IndexPreprocessor {
 
 fn warn_readme_name_conflict<P: AsRef<Path>>(readme_path: P, index_path: P) {
     let file_name = readme_path.as_ref().file_name().unwrap_or_default();
-    let parent_dir = index_path.as_ref().parent().unwrap_or(index_path.as_ref());
+    let parent_dir = index_path
+        .as_ref()
+        .parent()
+        .unwrap_or_else(|| index_path.as_ref());
     warn!(
         "It seems that there are both {:?} and index.md under \"{}\".",
         file_name,
@@ -67,7 +73,7 @@ fn is_readme_file<P: AsRef<Path>>(path: P) -> bool {
     RE.is_match(
         path.as_ref()
             .file_stem()
-            .and_then(|s| s.to_str())
+            .and_then(std::ffi::OsStr::to_str)
             .unwrap_or_default(),
     )
 }

src/preprocess/links.rs

@@ -1,18 +1,29 @@
-use errors::*;
+use crate::errors::*;
+use crate::utils::{
+    take_anchored_lines, take_lines, take_rustdoc_include_anchored_lines,
+    take_rustdoc_include_lines,
+};
 use regex::{CaptureMatches, Captures, Regex};
-use std::ops::{Range, RangeFrom, RangeFull, RangeTo};
+use std::fs;
+use std::ops::{Bound, Range, RangeBounds, RangeFrom, RangeFull, RangeTo};
 use std::path::{Path, PathBuf};
-use utils::fs::file_to_string;
-use utils::take_lines;
 
 use super::{Preprocessor, PreprocessorContext};
-use book::{Book, BookItem};
+use crate::book::{Book, BookItem};
 
 const ESCAPE_CHAR: char = '\\';
 const MAX_LINK_NESTED_DEPTH: usize = 10;
 
-/// A preprocessor for expanding the `{{# playpen}}` and `{{# include}}`
-/// helpers in a chapter.
+/// A preprocessor for expanding helpers in a chapter. Supported helpers are:
+///
+/// - `{{# include}}` - Insert an external file of any type. Include the whole file, only particular
+///.  lines, or only between the specified anchors.
+/// - `{{# rustdoc_include}}` - Insert an external Rust file, showing the particular lines
+///.  specified or the lines between specified anchors, and include the rest of the file behind `#`.
+///   This hides the lines from initial display but shows them when the reader expands the code
+///   block and provides them to Rustdoc for testing.
+/// - `{{# playground}}` - Insert runnable Rust files
+#[derive(Default)]
 pub struct LinkPreprocessor;
 
 impl LinkPreprocessor {
@@ -34,14 +45,15 @@ impl Preprocessor for LinkPreprocessor {
 
         book.for_each_mut(|section: &mut BookItem| {
             if let BookItem::Chapter(ref mut ch) = *section {
-                let base = ch
-                    .path
-                    .parent()
-                    .map(|dir| src_dir.join(dir))
-                    .expect("All book items have a parent");
+                if let Some(ref chapter_path) = ch.path {
+                    let base = chapter_path
+                        .parent()
+                        .map(|dir| src_dir.join(dir))
+                        .expect("All book items have a parent");
 
-                let content = replace_all(&ch.content, base, &ch.path, 0);
-                ch.content = content;
+                    let content = replace_all(&ch.content, base, chapter_path, 0);
+                    ch.content = content;
+                }
             }
         });
 
@@ -62,19 +74,14 @@ where
     let mut previous_end_index = 0;
     let mut replaced = String::new();
 
-    for playpen in find_links(s) {
-        replaced.push_str(&s[previous_end_index..playpen.start_index]);
+    for link in find_links(s) {
+        replaced.push_str(&s[previous_end_index..link.start_index]);
 
-        match playpen.render_with_path(&path) {
+        match link.render_with_path(&path) {
             Ok(new_content) => {
                 if depth < MAX_LINK_NESTED_DEPTH {
-                    if let Some(rel_path) = playpen.link.relative_path(path) {
-                        replaced.push_str(&replace_all(
-                            &new_content,
-                            rel_path,
-                            source,
-                            depth + 1,
-                        ));
+                    if let Some(rel_path) = link.link_type.relative_path(path) {
+                        replaced.push_str(&replace_all(&new_content, rel_path, source, depth + 1));
                     } else {
                         replaced.push_str(&new_content);
                     }
@@ -84,17 +91,17 @@ where
                         source.display()
                     );
                 }
-                previous_end_index = playpen.end_index;
+                previous_end_index = link.end_index;
             }
             Err(e) => {
-                error!("Error updating \"{}\", {}", playpen.link_text, e);
-                for cause in e.iter().skip(1) {
+                error!("Error updating \"{}\", {}", link.link_text, e);
+                for cause in e.chain().skip(1) {
                     warn!("Caused By: {}", cause);
                 }
 
                 // This should make sure we include the raw `{{# ... }}` snippet
                 // in the page content if there are any errors.
-                previous_end_index = playpen.start_index;
+                previous_end_index = link.start_index;
             }
         }
     }
@@ -106,11 +113,68 @@ where
 #[derive(PartialEq, Debug, Clone)]
 enum LinkType<'a> {
     Escaped,
-    IncludeRange(PathBuf, Range<usize>),
-    IncludeRangeFrom(PathBuf, RangeFrom<usize>),
-    IncludeRangeTo(PathBuf, RangeTo<usize>),
-    IncludeRangeFull(PathBuf, RangeFull),
-    Playpen(PathBuf, Vec<&'a str>),
+    Include(PathBuf, RangeOrAnchor),
+    Playground(PathBuf, Vec<&'a str>),
+    RustdocInclude(PathBuf, RangeOrAnchor),
+}
+
+#[derive(PartialEq, Debug, Clone)]
+enum RangeOrAnchor {
+    Range(LineRange),
+    Anchor(String),
+}
+
+// A range of lines specified with some include directive.
+#[derive(PartialEq, Debug, Clone)]
+enum LineRange {
+    Range(Range<usize>),
+    RangeFrom(RangeFrom<usize>),
+    RangeTo(RangeTo<usize>),
+    RangeFull(RangeFull),
+}
+
+impl RangeBounds<usize> for LineRange {
+    fn start_bound(&self) -> Bound<&usize> {
+        match self {
+            LineRange::Range(r) => r.start_bound(),
+            LineRange::RangeFrom(r) => r.start_bound(),
+            LineRange::RangeTo(r) => r.start_bound(),
+            LineRange::RangeFull(r) => r.start_bound(),
+        }
+    }
+
+    fn end_bound(&self) -> Bound<&usize> {
+        match self {
+            LineRange::Range(r) => r.end_bound(),
+            LineRange::RangeFrom(r) => r.end_bound(),
+            LineRange::RangeTo(r) => r.end_bound(),
+            LineRange::RangeFull(r) => r.end_bound(),
+        }
+    }
+}
+
+impl From<Range<usize>> for LineRange {
+    fn from(r: Range<usize>) -> LineRange {
+        LineRange::Range(r)
+    }
+}
+
+impl From<RangeFrom<usize>> for LineRange {
+    fn from(r: RangeFrom<usize>) -> LineRange {
+        LineRange::RangeFrom(r)
+    }
+}
+
+impl From<RangeTo<usize>> for LineRange {
+    fn from(r: RangeTo<usize>) -> LineRange {
+        LineRange::RangeTo(r)
+    }
+}
+
+impl From<RangeFull> for LineRange {
+    fn from(r: RangeFull) -> LineRange {
+        LineRange::RangeFull(r)
+    }
 }
 
 impl<'a> LinkType<'a> {
@@ -118,19 +182,9 @@ impl<'a> LinkType<'a> {
         let base = base.as_ref();
         match self {
             LinkType::Escaped => None,
-            LinkType::IncludeRange(p, _) => {
-                Some(return_relative_path(base, &p))
-            }
-            LinkType::IncludeRangeFrom(p, _) => {
-                Some(return_relative_path(base, &p))
-            }
-            LinkType::IncludeRangeTo(p, _) => {
-                Some(return_relative_path(base, &p))
-            }
-            LinkType::IncludeRangeFull(p, _) => {
-                Some(return_relative_path(base, &p))
-            }
-            LinkType::Playpen(p, _) => Some(return_relative_path(base, &p)),
+            LinkType::Include(p, _) => Some(return_relative_path(base, &p)),
+            LinkType::Playground(p, _) => Some(return_relative_path(base, &p)),
+            LinkType::RustdocInclude(p, _) => Some(return_relative_path(base, &p)),
         }
     }
 }
@@ -142,50 +196,59 @@ fn return_relative_path<P: AsRef<Path>>(base: P, relative: P) -> PathBuf {
         .to_path_buf()
 }
 
-fn parse_include_path(path: &str) -> LinkType<'static> {
-    let mut parts = path.split(':');
-    let path = parts.next().unwrap().into();
-    // subtract 1 since line numbers usually begin with 1
-    let start = parts
-        .next()
-        .and_then(|s| s.parse::<usize>().ok())
-        .map(|val| val.saturating_sub(1));
+fn parse_range_or_anchor(parts: Option<&str>) -> RangeOrAnchor {
+    let mut parts = parts.unwrap_or("").splitn(3, ':').fuse();
+
+    let next_element = parts.next();
+    let start = if let Some(value) = next_element.and_then(|s| s.parse::<usize>().ok()) {
+        // subtract 1 since line numbers usually begin with 1
+        Some(value.saturating_sub(1))
+    } else if let Some("") = next_element {
+        None
+    } else if let Some(anchor) = next_element {
+        return RangeOrAnchor::Anchor(String::from(anchor));
+    } else {
+        None
+    };
+
     let end = parts.next();
-    let has_end = end.is_some();
-    let end = end.and_then(|s| s.parse::<usize>().ok());
-    match start {
-        Some(start) => match end {
-            Some(end) => LinkType::IncludeRange(
-                path,
-                Range {
-                    start: start,
-                    end: end,
-                },
-            ),
-            None => if has_end {
-                LinkType::IncludeRangeFrom(path, RangeFrom { start: start })
-            } else {
-                LinkType::IncludeRange(
-                    path,
-                    Range {
-                        start: start,
-                        end: start + 1,
-                    },
-                )
-            },
-        },
-        None => match end {
-            Some(end) => LinkType::IncludeRangeTo(path, RangeTo { end: end }),
-            None => LinkType::IncludeRangeFull(path, RangeFull),
-        },
+    // If `end` is empty string or any other value that can't be parsed as a usize, treat this
+    // include as a range with only a start bound. However, if end isn't specified, include only
+    // the single line specified by `start`.
+    let end = end.map(|s| s.parse::<usize>());
+
+    match (start, end) {
+        (Some(start), Some(Ok(end))) => RangeOrAnchor::Range(LineRange::from(start..end)),
+        (Some(start), Some(Err(_))) => RangeOrAnchor::Range(LineRange::from(start..)),
+        (Some(start), None) => RangeOrAnchor::Range(LineRange::from(start..start + 1)),
+        (None, Some(Ok(end))) => RangeOrAnchor::Range(LineRange::from(..end)),
+        (None, None) | (None, Some(Err(_))) => RangeOrAnchor::Range(LineRange::from(RangeFull)),
     }
 }
 
+fn parse_include_path(path: &str) -> LinkType<'static> {
+    let mut parts = path.splitn(2, ':');
+
+    let path = parts.next().unwrap().into();
+    let range_or_anchor = parse_range_or_anchor(parts.next());
+
+    LinkType::Include(path, range_or_anchor)
+}
+
+fn parse_rustdoc_include_path(path: &str) -> LinkType<'static> {
+    let mut parts = path.splitn(2, ':');
+
+    let path = parts.next().unwrap().into();
+    let range_or_anchor = parse_range_or_anchor(parts.next());
+
+    LinkType::RustdocInclude(path, range_or_anchor)
+}
+
 #[derive(PartialEq, Debug, Clone)]
 struct Link<'a> {
     start_index: usize,
     end_index: usize,
-    link: LinkType<'a>,
+    link_type: LinkType<'a>,
     link_text: &'a str,
 }
 
@@ -199,25 +262,30 @@ impl<'a> Link<'a> {
 
                 match (typ.as_str(), file_arg) {
                     ("include", Some(pth)) => Some(parse_include_path(pth)),
+                    ("playground", Some(pth)) => Some(LinkType::Playground(pth.into(), props)),
                     ("playpen", Some(pth)) => {
-                        Some(LinkType::Playpen(pth.into(), props))
+                        warn!(
+                            "the {{{{#playpen}}}} expression has been \
+                            renamed to {{{{#playground}}}}, \
+                            please update your book to use the new name"
+                        );
+                        Some(LinkType::Playground(pth.into(), props))
                     }
+                    ("rustdoc_include", Some(pth)) => Some(parse_rustdoc_include_path(pth)),
                     _ => None,
                 }
             }
-            (Some(mat), None, None)
-                if mat.as_str().starts_with(ESCAPE_CHAR) =>
-            {
+            (Some(mat), None, None) if mat.as_str().starts_with(ESCAPE_CHAR) => {
                 Some(LinkType::Escaped)
             }
             _ => None,
         };
 
-        link_type.and_then(|lnk| {
+        link_type.and_then(|lnk_type| {
             cap.get(0).map(|mat| Link {
                 start_index: mat.start(),
                 end_index: mat.end(),
-                link: lnk,
+                link_type: lnk_type,
                 link_text: mat.as_str(),
             })
         })
@@ -225,15 +293,18 @@ impl<'a> Link<'a> {
 
     fn render_with_path<P: AsRef<Path>>(&self, base: P) -> Result<String> {
         let base = base.as_ref();
-        match self.link {
+        match self.link_type {
             // omit the escape char
             LinkType::Escaped => Ok((&self.link_text[1..]).to_owned()),
-            LinkType::IncludeRange(ref pat, ref range) => {
+            LinkType::Include(ref pat, ref range_or_anchor) => {
                 let target = base.join(pat);
 
-                file_to_string(&target)
-                    .map(|s| take_lines(&s, range.clone()))
-                    .chain_err(|| {
+                fs::read_to_string(&target)
+                    .map(|s| match range_or_anchor {
+                        RangeOrAnchor::Range(range) => take_lines(&s, range.clone()),
+                        RangeOrAnchor::Anchor(anchor) => take_anchored_lines(&s, anchor),
+                    })
+                    .with_context(|| {
                         format!(
                             "Could not read file for link {} ({})",
                             self.link_text,
@@ -241,12 +312,19 @@ impl<'a> Link<'a> {
                         )
                     })
             }
-            LinkType::IncludeRangeFrom(ref pat, ref range) => {
+            LinkType::RustdocInclude(ref pat, ref range_or_anchor) => {
                 let target = base.join(pat);
 
-                file_to_string(&target)
-                    .map(|s| take_lines(&s, range.clone()))
-                    .chain_err(|| {
+                fs::read_to_string(&target)
+                    .map(|s| match range_or_anchor {
+                        RangeOrAnchor::Range(range) => {
+                            take_rustdoc_include_lines(&s, range.clone())
+                        }
+                        RangeOrAnchor::Anchor(anchor) => {
+                            take_rustdoc_include_anchored_lines(&s, anchor)
+                        }
+                    })
+                    .with_context(|| {
                         format!(
                             "Could not read file for link {} ({})",
                             self.link_text,
@@ -254,39 +332,16 @@ impl<'a> Link<'a> {
                         )
                     })
             }
-            LinkType::IncludeRangeTo(ref pat, ref range) => {
+            LinkType::Playground(ref pat, ref attrs) => {
                 let target = base.join(pat);
 
-                file_to_string(&target)
-                    .map(|s| take_lines(&s, range.clone()))
-                    .chain_err(|| {
-                        format!(
-                            "Could not read file for link {} ({})",
-                            self.link_text,
-                            target.display(),
-                        )
-                    })
-            }
-            LinkType::IncludeRangeFull(ref pat, _) => {
-                let target = base.join(pat);
-
-                file_to_string(&target).chain_err(|| {
-                    format!("Could not read file for link {} ({})",
-                            self.link_text,
-                            target.display())
-                })
-            }
-            LinkType::Playpen(ref pat, ref attrs) => {
-                let target = base.join(pat);
-
-                let contents =
-                file_to_string(&target).chain_err(|| {
-                        format!(
-                            "Could not read file for link {} ({})",
-                            self.link_text,
-                            target.display()
-                        )
-                    })?;
+                let contents = fs::read_to_string(&target).with_context(|| {
+                    format!(
+                        "Could not read file for link {} ({})",
+                        self.link_text,
+                        target.display()
+                    )
+                })?;
                 let ftype = if !attrs.is_empty() { "rust," } else { "rust" };
                 Ok(format!(
                     "```{}{}\n{}\n```\n",
@@ -313,20 +368,21 @@ impl<'a> Iterator for LinkIter<'a> {
     }
 }
 
-fn find_links(contents: &str) -> LinkIter {
+fn find_links(contents: &str) -> LinkIter<'_> {
     // lazily compute following regex
     // r"\\\{\{#.*\}\}|\{\{#([a-zA-Z0-9]+)\s*([a-zA-Z0-9_.\-:/\\\s]+)\}\}")?;
     lazy_static! {
         static ref RE: Regex = Regex::new(
-            r"(?x)                     # insignificant whitespace mode
-            \\\{\{\#.*\}\}             # match escaped link
-            |                          # or
-            \{\{\s*                    # link opening parens and whitespace
-            \#([a-zA-Z0-9]+)           # link type
-            \s+                        # separating whitespace
-            ([a-zA-Z0-9\s_.\-:/\\]+)   # link target path and space separated properties
-            \s*\}\}                    # whitespace and link closing parens"
-        ).unwrap();
+            r"(?x)                       # insignificant whitespace mode
+            \\\{\{\#.*\}\}               # match escaped link
+            |                            # or
+            \{\{\s*                      # link opening parens and whitespace
+            \#([a-zA-Z0-9_]+)            # link type
+            \s+                          # separating whitespace
+            ([a-zA-Z0-9\s_.\-:/\\\+]+)   # link target path and space separated properties
+            \s*\}\}                      # whitespace and link closing parens"
+        )
+        .unwrap();
     }
     LinkIter(RE.captures_iter(contents))
 }
@@ -358,7 +414,7 @@ mod tests {
 
     #[test]
     fn test_find_links_partial_link() {
-        let s = "Some random text with {{#playpen...";
+        let s = "Some random text with {{#playground...";
         assert!(find_links(s).collect::<Vec<_>>() == vec![]);
         let s = "Some random text with {{#include...";
         assert!(find_links(s).collect::<Vec<_>>() == vec![]);
@@ -368,19 +424,19 @@ mod tests {
 
     #[test]
     fn test_find_links_empty_link() {
-        let s = "Some random text with {{#playpen}} and {{#playpen   }} {{}} {{#}}...";
+        let s = "Some random text with {{#playground}} and {{#playground   }} {{}} {{#}}...";
         assert!(find_links(s).collect::<Vec<_>>() == vec![]);
     }
 
     #[test]
     fn test_find_links_unknown_link_type() {
-        let s = "Some random text with {{#playpenz ar.rs}} and {{#incn}} {{baz}} {{#bar}}...";
+        let s = "Some random text with {{#playgroundz ar.rs}} and {{#incn}} {{baz}} {{#bar}}...";
         assert!(find_links(s).collect::<Vec<_>>() == vec![]);
     }
 
     #[test]
     fn test_find_links_simple_link() {
-        let s = "Some random text with {{#playpen file.rs}} and {{#playpen test.rs }}...";
+        let s = "Some random text with {{#playground file.rs}} and {{#playground test.rs }}...";
 
         let res = find_links(s).collect::<Vec<_>>();
         println!("\nOUTPUT: {:?}\n", res);
@@ -390,20 +446,38 @@ mod tests {
             vec![
                 Link {
                     start_index: 22,
-                    end_index: 42,
-                    link: LinkType::Playpen(PathBuf::from("file.rs"), vec![]),
-                    link_text: "{{#playpen file.rs}}",
+                    end_index: 45,
+                    link_type: LinkType::Playground(PathBuf::from("file.rs"), vec![]),
+                    link_text: "{{#playground file.rs}}",
                 },
                 Link {
-                    start_index: 47,
-                    end_index: 68,
-                    link: LinkType::Playpen(PathBuf::from("test.rs"), vec![]),
-                    link_text: "{{#playpen test.rs }}",
+                    start_index: 50,
+                    end_index: 74,
+                    link_type: LinkType::Playground(PathBuf::from("test.rs"), vec![]),
+                    link_text: "{{#playground test.rs }}",
                 },
             ]
         );
     }
 
+    #[test]
+    fn test_find_links_with_special_characters() {
+        let s = "Some random text with {{#playground foo-bar\\baz/_c++.rs}}...";
+
+        let res = find_links(s).collect::<Vec<_>>();
+        println!("\nOUTPUT: {:?}\n", res);
+
+        assert_eq!(
+            res,
+            vec![Link {
+                start_index: 22,
+                end_index: 57,
+                link_type: LinkType::Playground(PathBuf::from("foo-bar\\baz/_c++.rs"), vec![]),
+                link_text: "{{#playground foo-bar\\baz/_c++.rs}}",
+            },]
+        );
+    }
+
     #[test]
     fn test_find_links_with_range() {
         let s = "Some random text with {{#include file.rs:10:20}}...";
@@ -414,7 +488,10 @@ mod tests {
             vec![Link {
                 start_index: 22,
                 end_index: 48,
-                link: LinkType::IncludeRange(PathBuf::from("file.rs"), 9..20),
+                link_type: LinkType::Include(
+                    PathBuf::from("file.rs"),
+                    RangeOrAnchor::Range(LineRange::from(9..20))
+                ),
                 link_text: "{{#include file.rs:10:20}}",
             }]
         );
@@ -430,7 +507,10 @@ mod tests {
             vec![Link {
                 start_index: 22,
                 end_index: 45,
-                link: LinkType::IncludeRange(PathBuf::from("file.rs"), 9..10),
+                link_type: LinkType::Include(
+                    PathBuf::from("file.rs"),
+                    RangeOrAnchor::Range(LineRange::from(9..10))
+                ),
                 link_text: "{{#include file.rs:10}}",
             }]
         );
@@ -446,7 +526,10 @@ mod tests {
             vec![Link {
                 start_index: 22,
                 end_index: 46,
-                link: LinkType::IncludeRangeFrom(PathBuf::from("file.rs"), 9..),
+                link_type: LinkType::Include(
+                    PathBuf::from("file.rs"),
+                    RangeOrAnchor::Range(LineRange::from(9..))
+                ),
                 link_text: "{{#include file.rs:10:}}",
             }]
         );
@@ -462,7 +545,10 @@ mod tests {
             vec![Link {
                 start_index: 22,
                 end_index: 46,
-                link: LinkType::IncludeRangeTo(PathBuf::from("file.rs"), ..20),
+                link_type: LinkType::Include(
+                    PathBuf::from("file.rs"),
+                    RangeOrAnchor::Range(LineRange::from(..20))
+                ),
                 link_text: "{{#include file.rs::20}}",
             }]
         );
@@ -478,7 +564,10 @@ mod tests {
             vec![Link {
                 start_index: 22,
                 end_index: 44,
-                link: LinkType::IncludeRangeFull(PathBuf::from("file.rs"), ..),
+                link_type: LinkType::Include(
+                    PathBuf::from("file.rs"),
+                    RangeOrAnchor::Range(LineRange::from(..))
+                ),
                 link_text: "{{#include file.rs::}}",
             }]
         );
@@ -494,15 +583,37 @@ mod tests {
             vec![Link {
                 start_index: 22,
                 end_index: 42,
-                link: LinkType::IncludeRangeFull(PathBuf::from("file.rs"), ..),
+                link_type: LinkType::Include(
+                    PathBuf::from("file.rs"),
+                    RangeOrAnchor::Range(LineRange::from(..))
+                ),
                 link_text: "{{#include file.rs}}",
             }]
         );
     }
 
+    #[test]
+    fn test_find_links_with_anchor() {
+        let s = "Some random text with {{#include file.rs:anchor}}...";
+        let res = find_links(s).collect::<Vec<_>>();
+        println!("\nOUTPUT: {:?}\n", res);
+        assert_eq!(
+            res,
+            vec![Link {
+                start_index: 22,
+                end_index: 49,
+                link_type: LinkType::Include(
+                    PathBuf::from("file.rs"),
+                    RangeOrAnchor::Anchor(String::from("anchor"))
+                ),
+                link_text: "{{#include file.rs:anchor}}",
+            }]
+        );
+    }
+
     #[test]
     fn test_find_links_escaped_link() {
-        let s = "Some random text with escaped playpen \\{{#playpen file.rs editable}} ...";
+        let s = "Some random text with escaped playground \\{{#playground file.rs editable}} ...";
 
         let res = find_links(s).collect::<Vec<_>>();
         println!("\nOUTPUT: {:?}\n", res);
@@ -510,18 +621,19 @@ mod tests {
         assert_eq!(
             res,
             vec![Link {
-                start_index: 38,
-                end_index: 68,
-                link: LinkType::Escaped,
-                link_text: "\\{{#playpen file.rs editable}}",
+                start_index: 41,
+                end_index: 74,
+                link_type: LinkType::Escaped,
+                link_text: "\\{{#playground file.rs editable}}",
             }]
         );
     }
 
     #[test]
-    fn test_find_playpens_with_properties() {
-        let s = "Some random text with escaped playpen {{#playpen file.rs editable }} and some \
-                 more\n text {{#playpen my.rs editable no_run should_panic}} ...";
+    fn test_find_playgrounds_with_properties() {
+        let s =
+            "Some random text with escaped playground {{#playground file.rs editable }} and some \
+                 more\n text {{#playground my.rs editable no_run should_panic}} ...";
 
         let res = find_links(s).collect::<Vec<_>>();
         println!("\nOUTPUT: {:?}\n", res);
@@ -529,23 +641,19 @@ mod tests {
             res,
             vec![
                 Link {
-                    start_index: 38,
-                    end_index: 68,
-                    link: LinkType::Playpen(
-                        PathBuf::from("file.rs"),
-                        vec!["editable"]
-                    ),
-                    link_text: "{{#playpen file.rs editable }}",
+                    start_index: 41,
+                    end_index: 74,
+                    link_type: LinkType::Playground(PathBuf::from("file.rs"), vec!["editable"]),
+                    link_text: "{{#playground file.rs editable }}",
                 },
                 Link {
-                    start_index: 89,
-                    end_index: 136,
-                    link: LinkType::Playpen(
+                    start_index: 95,
+                    end_index: 145,
+                    link_type: LinkType::Playground(
                         PathBuf::from("my.rs"),
                         vec!["editable", "no_run", "should_panic"],
                     ),
-                    link_text:
-                        "{{#playpen my.rs editable no_run should_panic}}",
+                    link_text: "{{#playground my.rs editable no_run should_panic}}",
                 },
             ]
         );
@@ -553,8 +661,9 @@ mod tests {
 
     #[test]
     fn test_find_all_link_types() {
-        let s = "Some random text with escaped playpen {{#include file.rs}} and \\{{#contents are \
-                 insignifficant in escaped link}} some more\n text  {{#playpen my.rs editable \
+        let s =
+            "Some random text with escaped playground {{#include file.rs}} and \\{{#contents are \
+                 insignifficant in escaped link}} some more\n text  {{#playground my.rs editable \
                  no_run should_panic}} ...";
 
         let res = find_links(s).collect::<Vec<_>>();
@@ -563,33 +672,215 @@ mod tests {
         assert_eq!(
             res[0],
             Link {
-                start_index: 38,
-                end_index: 58,
-                link: LinkType::IncludeRangeFull(PathBuf::from("file.rs"), ..),
+                start_index: 41,
+                end_index: 61,
+                link_type: LinkType::Include(
+                    PathBuf::from("file.rs"),
+                    RangeOrAnchor::Range(LineRange::from(..))
+                ),
                 link_text: "{{#include file.rs}}",
             }
         );
         assert_eq!(
             res[1],
             Link {
-                start_index: 63,
-                end_index: 112,
-                link: LinkType::Escaped,
+                start_index: 66,
+                end_index: 115,
+                link_type: LinkType::Escaped,
                 link_text: "\\{{#contents are insignifficant in escaped link}}",
             }
         );
         assert_eq!(
             res[2],
             Link {
-                start_index: 130,
-                end_index: 177,
-                link: LinkType::Playpen(
+                start_index: 133,
+                end_index: 183,
+                link_type: LinkType::Playground(
                     PathBuf::from("my.rs"),
                     vec!["editable", "no_run", "should_panic"]
                 ),
-                link_text: "{{#playpen my.rs editable no_run should_panic}}",
+                link_text: "{{#playground my.rs editable no_run should_panic}}",
             }
         );
     }
 
+    #[test]
+    fn parse_without_colon_includes_all() {
+        let link_type = parse_include_path("arbitrary");
+        assert_eq!(
+            link_type,
+            LinkType::Include(
+                PathBuf::from("arbitrary"),
+                RangeOrAnchor::Range(LineRange::from(RangeFull))
+            )
+        );
+    }
+
+    #[test]
+    fn parse_with_nothing_after_colon_includes_all() {
+        let link_type = parse_include_path("arbitrary:");
+        assert_eq!(
+            link_type,
+            LinkType::Include(
+                PathBuf::from("arbitrary"),
+                RangeOrAnchor::Range(LineRange::from(RangeFull))
+            )
+        );
+    }
+
+    #[test]
+    fn parse_with_two_colons_includes_all() {
+        let link_type = parse_include_path("arbitrary::");
+        assert_eq!(
+            link_type,
+            LinkType::Include(
+                PathBuf::from("arbitrary"),
+                RangeOrAnchor::Range(LineRange::from(RangeFull))
+            )
+        );
+    }
+
+    #[test]
+    fn parse_with_garbage_after_two_colons_includes_all() {
+        let link_type = parse_include_path("arbitrary::NaN");
+        assert_eq!(
+            link_type,
+            LinkType::Include(
+                PathBuf::from("arbitrary"),
+                RangeOrAnchor::Range(LineRange::from(RangeFull))
+            )
+        );
+    }
+
+    #[test]
+    fn parse_with_one_number_after_colon_only_that_line() {
+        let link_type = parse_include_path("arbitrary:5");
+        assert_eq!(
+            link_type,
+            LinkType::Include(
+                PathBuf::from("arbitrary"),
+                RangeOrAnchor::Range(LineRange::from(4..5))
+            )
+        );
+    }
+
+    #[test]
+    fn parse_with_one_based_start_becomes_zero_based() {
+        let link_type = parse_include_path("arbitrary:1");
+        assert_eq!(
+            link_type,
+            LinkType::Include(
+                PathBuf::from("arbitrary"),
+                RangeOrAnchor::Range(LineRange::from(0..1))
+            )
+        );
+    }
+
+    #[test]
+    fn parse_with_zero_based_start_stays_zero_based_but_is_probably_an_error() {
+        let link_type = parse_include_path("arbitrary:0");
+        assert_eq!(
+            link_type,
+            LinkType::Include(
+                PathBuf::from("arbitrary"),
+                RangeOrAnchor::Range(LineRange::from(0..1))
+            )
+        );
+    }
+
+    #[test]
+    fn parse_start_only_range() {
+        let link_type = parse_include_path("arbitrary:5:");
+        assert_eq!(
+            link_type,
+            LinkType::Include(
+                PathBuf::from("arbitrary"),
+                RangeOrAnchor::Range(LineRange::from(4..))
+            )
+        );
+    }
+
+    #[test]
+    fn parse_start_with_garbage_interpreted_as_start_only_range() {
+        let link_type = parse_include_path("arbitrary:5:NaN");
+        assert_eq!(
+            link_type,
+            LinkType::Include(
+                PathBuf::from("arbitrary"),
+                RangeOrAnchor::Range(LineRange::from(4..))
+            )
+        );
+    }
+
+    #[test]
+    fn parse_end_only_range() {
+        let link_type = parse_include_path("arbitrary::5");
+        assert_eq!(
+            link_type,
+            LinkType::Include(
+                PathBuf::from("arbitrary"),
+                RangeOrAnchor::Range(LineRange::from(..5))
+            )
+        );
+    }
+
+    #[test]
+    fn parse_start_and_end_range() {
+        let link_type = parse_include_path("arbitrary:5:10");
+        assert_eq!(
+            link_type,
+            LinkType::Include(
+                PathBuf::from("arbitrary"),
+                RangeOrAnchor::Range(LineRange::from(4..10))
+            )
+        );
+    }
+
+    #[test]
+    fn parse_with_negative_interpreted_as_anchor() {
+        let link_type = parse_include_path("arbitrary:-5");
+        assert_eq!(
+            link_type,
+            LinkType::Include(
+                PathBuf::from("arbitrary"),
+                RangeOrAnchor::Anchor("-5".to_string())
+            )
+        );
+    }
+
+    #[test]
+    fn parse_with_floating_point_interpreted_as_anchor() {
+        let link_type = parse_include_path("arbitrary:-5.7");
+        assert_eq!(
+            link_type,
+            LinkType::Include(
+                PathBuf::from("arbitrary"),
+                RangeOrAnchor::Anchor("-5.7".to_string())
+            )
+        );
+    }
+
+    #[test]
+    fn parse_with_anchor_followed_by_colon() {
+        let link_type = parse_include_path("arbitrary:some-anchor:this-gets-ignored");
+        assert_eq!(
+            link_type,
+            LinkType::Include(
+                PathBuf::from("arbitrary"),
+                RangeOrAnchor::Anchor("some-anchor".to_string())
+            )
+        );
+    }
+
+    #[test]
+    fn parse_with_more_than_three_colons_ignores_everything_after_third_colon() {
+        let link_type = parse_include_path("arbitrary:5:10:17:anything:");
+        assert_eq!(
+            link_type,
+            LinkType::Include(
+                PathBuf::from("arbitrary"),
+                RangeOrAnchor::Range(LineRange::from(4..10))
+            )
+        );
+    }
 }

src/preprocess/mod.rs

@@ -1,16 +1,16 @@
 //! Book preprocessing.
 
+pub use self::cmd::CmdPreprocessor;
 pub use self::index::IndexPreprocessor;
 pub use self::links::LinkPreprocessor;
-pub use self::cmd::CmdPreprocessor;
 
+mod cmd;
 mod index;
 mod links;
-mod cmd;
 
-use book::Book;
-use config::Config;
-use errors::*;
+use crate::book::Book;
+use crate::config::Config;
+use crate::errors::*;
 
 use std::path::PathBuf;
 
@@ -26,6 +26,7 @@ pub struct PreprocessorContext {
     pub renderer: String,
     /// The calling `mdbook` version.
     pub mdbook_version: String,
+    #[serde(skip)]
     __non_exhaustive: (),
 }
 
@@ -36,7 +37,7 @@ impl PreprocessorContext {
             root,
             config,
             renderer,
-            mdbook_version: ::MDBOOK_VERSION.to_string(),
+            mdbook_version: crate::MDBOOK_VERSION.to_string(),
             __non_exhaustive: (),
         }
     }

src/renderer/html_handlebars/hbs_renderer.rs

@@ -1,19 +1,20 @@
-use book::{Book, BookItem};
-use config::{Config, HtmlConfig, Playpen};
-use errors::*;
-use renderer::html_handlebars::helpers;
-use renderer::{RenderContext, Renderer};
-use theme::{self, playpen_editor, Theme};
-use utils;
+use crate::book::{Book, BookItem};
+use crate::config::{Config, HtmlConfig, Playground, RustEdition};
+use crate::errors::*;
+use crate::renderer::html_handlebars::helpers;
+use crate::renderer::{RenderContext, Renderer};
+use crate::theme::{self, playground_editor, Theme};
+use crate::utils;
 
+use std::borrow::Cow;
 use std::collections::BTreeMap;
 use std::collections::HashMap;
-use std::fs;
+use std::fs::{self, File};
 use std::path::{Path, PathBuf};
 
+use crate::utils::fs::get_404_output_file;
 use handlebars::Handlebars;
 use regex::{Captures, Regex};
-use serde_json;
 
 #[derive(Default)]
 pub struct HtmlHandlebars;
@@ -26,83 +27,148 @@ impl HtmlHandlebars {
     fn render_item(
         &self,
         item: &BookItem,
-        mut ctx: RenderItemContext,
+        mut ctx: RenderItemContext<'_>,
         print_content: &mut String,
     ) -> Result<()> {
         // FIXME: This should be made DRY-er and rely less on mutable state
-        match *item {
-            BookItem::Chapter(ref ch) => {
-                let content = ch.content.clone();
-                let content = utils::render_markdown(&content, ctx.html_config.curly_quotes);
-                print_content.push_str(&content);
 
-                // Update the context with data for this file
-                let path = ch
-                    .path
-                    .to_str()
-                    .chain_err(|| "Could not convert path to str")?;
-                let filepath = Path::new(&ch.path).with_extension("html");
+        let (ch, path) = match item {
+            BookItem::Chapter(ch) if !ch.is_draft_chapter() => (ch, ch.path.as_ref().unwrap()),
+            _ => return Ok(()),
+        };
 
-                // "print.html" is used for the print page.
-                if ch.path == Path::new("print.md") {
-                    bail!(ErrorKind::ReservedFilenameError(ch.path.clone()));
-                };
+        let content = ch.content.clone();
+        let content = utils::render_markdown(&content, ctx.html_config.curly_quotes);
 
-                // Non-lexical lifetimes needed :'(
-                let title: String;
-                {
-                    let book_title = ctx
-                        .data
-                        .get("book_title")
-                        .and_then(serde_json::Value::as_str)
-                        .unwrap_or("");
-                    title = ch.name.clone() + " - " + book_title;
-                }
+        let fixed_content = utils::render_markdown_with_path(
+            &ch.content,
+            ctx.html_config.curly_quotes,
+            Some(&path),
+        );
+        print_content.push_str(&fixed_content);
 
-                ctx.data.insert("path".to_owned(), json!(path));
-                ctx.data.insert("content".to_owned(), json!(content));
-                ctx.data.insert("chapter_title".to_owned(), json!(ch.name));
-                ctx.data.insert("title".to_owned(), json!(title));
-                ctx.data.insert(
-                    "path_to_root".to_owned(),
-                    json!(utils::fs::path_to_root(&ch.path)),
-                );
+        // Update the context with data for this file
+        let ctx_path = path
+            .to_str()
+            .with_context(|| "Could not convert path to str")?;
+        let filepath = Path::new(&ctx_path).with_extension("html");
 
-                // Render the handlebars template with the data
-                debug!("Render template");
-                let rendered = ctx.handlebars.render("index", &ctx.data)?;
+        // "print.html" is used for the print page.
+        if path == Path::new("print.md") {
+            bail!("{} is reserved for internal use", path.display());
+        };
 
-                let rendered = self.post_process(rendered, &ctx.html_config.playpen);
+        let book_title = ctx
+            .data
+            .get("book_title")
+            .and_then(serde_json::Value::as_str)
+            .unwrap_or("");
 
-                // Write to file
-                debug!("Creating {}", filepath.display());
-                utils::fs::write_file(&ctx.destination, &filepath, rendered.as_bytes())?;
+        let title = match book_title {
+            "" => ch.name.clone(),
+            _ => ch.name.clone() + " - " + book_title,
+        };
 
-                if ctx.is_index {
-                    ctx.data.insert("path".to_owned(), json!("index.html"));
-                    ctx.data.insert("path_to_root".to_owned(), json!(""));
-                    let rendered_index = ctx.handlebars.render("index", &ctx.data)?;
-                    let rendered_index =
-                        self.post_process(rendered_index, &ctx.html_config.playpen);
-                    debug!("Creating index.html from {}", path);
-                    utils::fs::write_file(
-                        &ctx.destination,
-                        "index.html",
-                        rendered_index.as_bytes(),
-                    )?;
-                }
-            }
-            _ => {}
+        ctx.data.insert("path".to_owned(), json!(path));
+        ctx.data.insert("content".to_owned(), json!(content));
+        ctx.data.insert("chapter_title".to_owned(), json!(ch.name));
+        ctx.data.insert("title".to_owned(), json!(title));
+        ctx.data.insert(
+            "path_to_root".to_owned(),
+            json!(utils::fs::path_to_root(&path)),
+        );
+        if let Some(ref section) = ch.number {
+            ctx.data
+                .insert("section".to_owned(), json!(section.to_string()));
+        }
+
+        // Render the handlebars template with the data
+        debug!("Render template");
+        let rendered = ctx.handlebars.render("index", &ctx.data)?;
+
+        let rendered = self.post_process(rendered, &ctx.html_config.playground, ctx.edition);
+
+        // Write to file
+        debug!("Creating {}", filepath.display());
+        utils::fs::write_file(&ctx.destination, &filepath, rendered.as_bytes())?;
+
+        if ctx.is_index {
+            ctx.data.insert("path".to_owned(), json!("index.md"));
+            ctx.data.insert("path_to_root".to_owned(), json!(""));
+            ctx.data.insert("is_index".to_owned(), json!("true"));
+            let rendered_index = ctx.handlebars.render("index", &ctx.data)?;
+            let rendered_index =
+                self.post_process(rendered_index, &ctx.html_config.playground, ctx.edition);
+            debug!("Creating index.html from {}", ctx_path);
+            utils::fs::write_file(&ctx.destination, "index.html", rendered_index.as_bytes())?;
         }
 
         Ok(())
     }
 
-    #[cfg_attr(feature = "cargo-clippy", allow(let_and_return))]
-    fn post_process(&self, rendered: String, playpen_config: &Playpen) -> String {
+    fn render_404(
+        &self,
+        ctx: &RenderContext,
+        html_config: &HtmlConfig,
+        src_dir: &PathBuf,
+        handlebars: &mut Handlebars<'_>,
+        data: &mut serde_json::Map<String, serde_json::Value>,
+    ) -> Result<()> {
+        let destination = &ctx.destination;
+        let content_404 = if let Some(ref filename) = html_config.input_404 {
+            let path = src_dir.join(filename);
+            std::fs::read_to_string(&path)
+                .with_context(|| format!("unable to open 404 input file {:?}", path))?
+        } else {
+            // 404 input not explicitly configured try the default file 404.md
+            let default_404_location = src_dir.join("404.md");
+            if default_404_location.exists() {
+                std::fs::read_to_string(&default_404_location).with_context(|| {
+                    format!("unable to open 404 input file {:?}", default_404_location)
+                })?
+            } else {
+                "# Document not found (404)\n\nThis URL is invalid, sorry. Please use the \
+                navigation bar or search to continue."
+                    .to_string()
+            }
+        };
+        let html_content_404 = utils::render_markdown(&content_404, html_config.curly_quotes);
+
+        let mut data_404 = data.clone();
+        let base_url = if let Some(site_url) = &html_config.site_url {
+            site_url
+        } else {
+            debug!(
+                "HTML 'site-url' parameter not set, defaulting to '/'. Please configure \
+                this to ensure the 404 page work correctly, especially if your site is hosted in a \
+                subdirectory on the HTTP server."
+            );
+            "/"
+        };
+        data_404.insert("base_url".to_owned(), json!(base_url));
+        // Set a dummy path to ensure other paths (e.g. in the TOC) are generated correctly
+        data_404.insert("path".to_owned(), json!("404.md"));
+        data_404.insert("content".to_owned(), json!(html_content_404));
+        let rendered = handlebars.render("index", &data_404)?;
+
+        let rendered =
+            self.post_process(rendered, &html_config.playground, ctx.config.rust.edition);
+        let output_file = get_404_output_file(&html_config.input_404);
+        utils::fs::write_file(&destination, output_file, rendered.as_bytes())?;
+        debug!("Creating 404.html ✓");
+        Ok(())
+    }
+
+    #[cfg_attr(feature = "cargo-clippy", allow(clippy::let_and_return))]
+    fn post_process(
+        &self,
+        rendered: String,
+        playground_config: &Playground,
+        edition: Option<RustEdition>,
+    ) -> String {
         let rendered = build_header_links(&rendered);
         let rendered = fix_code_blocks(&rendered);
-        let rendered = add_playpen_pre(&rendered, playpen_config);
+        let rendered = add_playground_pre(&rendered, playground_config, edition);
 
         rendered
     }
@@ -113,7 +179,7 @@ impl HtmlHandlebars {
         theme: &Theme,
         html_config: &HtmlConfig,
     ) -> Result<()> {
-        use utils::fs::write_file;
+        use crate::utils::fs::write_file;
 
         write_file(
             destination,
@@ -126,7 +192,12 @@ impl HtmlHandlebars {
         write_file(destination, "css/chrome.css", &theme.chrome_css)?;
         write_file(destination, "css/print.css", &theme.print_css)?;
         write_file(destination, "css/variables.css", &theme.variables_css)?;
-        write_file(destination, "favicon.png", &theme.favicon)?;
+        if let Some(contents) = &theme.favicon_png {
+            write_file(destination, "favicon.png", &contents)?;
+        }
+        if let Some(contents) = &theme.favicon_svg {
+            write_file(destination, "favicon.svg", &contents)?;
+        }
         write_file(destination, "highlight.css", &theme.highlight_css)?;
         write_file(destination, "tomorrow-night.css", &theme.tomorrow_night_css)?;
         write_file(destination, "ayu-highlight.css", &theme.ayu_highlight_css)?;
@@ -167,20 +238,38 @@ impl HtmlHandlebars {
             "FontAwesome/fonts/FontAwesome.ttf",
             theme::FONT_AWESOME_TTF,
         )?;
+        if html_config.copy_fonts {
+            write_file(destination, "fonts/fonts.css", theme::fonts::CSS)?;
+            for (file_name, contents) in theme::fonts::LICENSES.iter() {
+                write_file(destination, file_name, contents)?;
+            }
+            for (file_name, contents) in theme::fonts::OPEN_SANS.iter() {
+                write_file(destination, file_name, contents)?;
+            }
+            write_file(
+                destination,
+                theme::fonts::SOURCE_CODE_PRO.0,
+                theme::fonts::SOURCE_CODE_PRO.1,
+            )?;
+        }
 
-        let playpen_config = &html_config.playpen;
+        let playground_config = &html_config.playground;
 
         // Ace is a very large dependency, so only load it when requested
-        if playpen_config.editable && playpen_config.copy_js {
+        if playground_config.editable && playground_config.copy_js {
             // Load the editor
-            write_file(destination, "editor.js", playpen_editor::JS)?;
-            write_file(destination, "ace.js", playpen_editor::ACE_JS)?;
-            write_file(destination, "mode-rust.js", playpen_editor::MODE_RUST_JS)?;
-            write_file(destination, "theme-dawn.js", playpen_editor::THEME_DAWN_JS)?;
+            write_file(destination, "editor.js", playground_editor::JS)?;
+            write_file(destination, "ace.js", playground_editor::ACE_JS)?;
+            write_file(destination, "mode-rust.js", playground_editor::MODE_RUST_JS)?;
+            write_file(
+                destination,
+                "theme-dawn.js",
+                playground_editor::THEME_DAWN_JS,
+            )?;
             write_file(
                 destination,
                 "theme-tomorrow_night.js",
-                playpen_editor::THEME_TOMORROW_NIGHT_JS,
+                playground_editor::THEME_TOMORROW_NIGHT_JS,
             )?;
         }
 
@@ -205,7 +294,7 @@ impl HtmlHandlebars {
         );
     }
 
-    fn register_hbs_helpers(&self, handlebars: &mut Handlebars, html_config: &HtmlConfig) {
+    fn register_hbs_helpers(&self, handlebars: &mut Handlebars<'_>, html_config: &HtmlConfig) {
         handlebars.register_helper(
             "toc",
             Box::new(helpers::toc::RenderToc {
@@ -214,6 +303,7 @@ impl HtmlHandlebars {
         );
         handlebars.register_helper("previous", Box::new(helpers::navigation::previous));
         handlebars.register_helper("next", Box::new(helpers::navigation::next));
+        handlebars.register_helper("theme_option", Box::new(helpers::theme::theme_option));
     }
 
     /// Copy across any additional CSS and JavaScript files which the book
@@ -233,7 +323,7 @@ impl HtmlHandlebars {
             let output_location = destination.join(custom_file);
             if let Some(parent) = output_location.parent() {
                 fs::create_dir_all(parent)
-                    .chain_err(|| format!("Unable to create {}", parent.display()))?;
+                    .with_context(|| format!("Unable to create {}", parent.display()))?;
             }
             debug!(
                 "Copying {} -> {}",
@@ -241,7 +331,7 @@ impl HtmlHandlebars {
                 output_location.display()
             );
 
-            fs::copy(&input_location, &output_location).chain_err(|| {
+            fs::copy(&input_location, &output_location).with_context(|| {
                 format!(
                     "Unable to copy {} to {}",
                     input_location.display(),
@@ -252,6 +342,68 @@ impl HtmlHandlebars {
 
         Ok(())
     }
+
+    fn emit_redirects(
+        &self,
+        root: &Path,
+        handlebars: &Handlebars<'_>,
+        redirects: &HashMap<String, String>,
+    ) -> Result<()> {
+        if redirects.is_empty() {
+            return Ok(());
+        }
+
+        log::debug!("Emitting redirects");
+
+        for (original, new) in redirects {
+            log::debug!("Redirecting \"{}\" → \"{}\"", original, new);
+            // Note: all paths are relative to the build directory, so the
+            // leading slash in an absolute path means nothing (and would mess
+            // up `root.join(original)`).
+            let original = original.trim_start_matches("/");
+            let filename = root.join(original);
+            self.emit_redirect(handlebars, &filename, new)?;
+        }
+
+        Ok(())
+    }
+
+    fn emit_redirect(
+        &self,
+        handlebars: &Handlebars<'_>,
+        original: &Path,
+        destination: &str,
+    ) -> Result<()> {
+        if original.exists() {
+            // sanity check to avoid accidentally overwriting a real file.
+            let msg = format!(
+                "Not redirecting \"{}\" to \"{}\" because it already exists. Are you sure it needs to be redirected?",
+                original.display(),
+                destination,
+            );
+            return Err(Error::msg(msg));
+        }
+
+        if let Some(parent) = original.parent() {
+            std::fs::create_dir_all(parent)
+                .with_context(|| format!("Unable to ensure \"{}\" exists", parent.display()))?;
+        }
+
+        let ctx = json!({
+            "url": destination,
+        });
+        let f = File::create(original)?;
+        handlebars
+            .render_to_write("redirect", &ctx, f)
+            .with_context(|| {
+                format!(
+                    "Unable to create a redirect file at \"{}\"",
+                    original.display()
+                )
+            })?;
+
+        Ok(())
+    }
 }
 
 // TODO(mattico): Remove some time after the 0.1.8 release
@@ -283,6 +435,12 @@ impl Renderer for HtmlHandlebars {
         let src_dir = ctx.root.join(&ctx.config.book.src);
         let destination = &ctx.destination;
         let book = &ctx.book;
+        let build_dir = ctx.root.join(&ctx.config.build.build_dir);
+
+        if destination.exists() {
+            utils::fs::remove_dir_content(destination)
+                .with_context(|| "Unable to remove stale HTML output")?;
+        }
 
         trace!("render");
         let mut handlebars = Handlebars::new();
@@ -307,6 +465,13 @@ impl Renderer for HtmlHandlebars {
         debug!("Register the index handlebars template");
         handlebars.register_template_string("index", String::from_utf8(theme.index.clone())?)?;
 
+        debug!("Register the head handlebars template");
+        handlebars.register_partial("head", String::from_utf8(theme.head.clone())?)?;
+
+        debug!("Register the redirect handlebars template");
+        handlebars
+            .register_template_string("redirect", String::from_utf8(theme.redirect.clone())?)?;
+
         debug!("Register the header handlebars template");
         handlebars.register_partial("header", String::from_utf8(theme.header.clone())?)?;
 
@@ -319,7 +484,7 @@ impl Renderer for HtmlHandlebars {
         let mut print_content = String::new();
 
         fs::create_dir_all(&destination)
-            .chain_err(|| "Unexpected error when constructing destination path")?;
+            .with_context(|| "Unexpected error when constructing destination path")?;
 
         let mut is_index = true;
         for item in book.iter() {
@@ -327,13 +492,19 @@ impl Renderer for HtmlHandlebars {
                 handlebars: &handlebars,
                 destination: destination.to_path_buf(),
                 data: data.clone(),
-                is_index: is_index,
+                is_index,
                 html_config: html_config.clone(),
+                edition: ctx.config.rust.edition,
             };
             self.render_item(item, ctx, &mut print_content)?;
             is_index = false;
         }
 
+        // Render 404 page
+        if html_config.input_404 != Some("".to_string()) {
+            self.render_404(ctx, &html_config, &src_dir, &mut handlebars, &mut data)?;
+        }
+
         // Print version
         self.configure_print_version(&mut data, &print_content);
         if let Some(ref title) = ctx.config.book.title {
@@ -344,16 +515,17 @@ impl Renderer for HtmlHandlebars {
         debug!("Render template");
         let rendered = handlebars.render("index", &data)?;
 
-        let rendered = self.post_process(rendered, &html_config.playpen);
+        let rendered =
+            self.post_process(rendered, &html_config.playground, ctx.config.rust.edition);
 
         utils::fs::write_file(&destination, "print.html", rendered.as_bytes())?;
         debug!("Creating print.html ✓");
 
         debug!("Copy static files");
         self.copy_static_files(&destination, &theme, &html_config)
-            .chain_err(|| "Unable to copy across static files")?;
+            .with_context(|| "Unable to copy across static files")?;
         self.copy_additional_css_and_js(&html_config, &ctx.root, &destination)
-            .chain_err(|| "Unable to copy across additional CSS and JS")?;
+            .with_context(|| "Unable to copy across additional CSS and JS")?;
 
         // Render search index
         #[cfg(feature = "search")]
@@ -364,8 +536,11 @@ impl Renderer for HtmlHandlebars {
             }
         }
 
-        // Copy all remaining files
-        utils::fs::copy_files_except_ext(&src_dir, &destination, true, &["md"])?;
+        self.emit_redirects(&ctx.destination, &handlebars, &html_config.redirect)
+            .context("Unable to emit redirects")?;
+
+        // Copy all remaining files, avoid a recursive copy from/to the book build dir
+        utils::fs::copy_files_except_ext(&src_dir, &destination, true, Some(&build_dir), &["md"])?;
 
         Ok(())
     }
@@ -378,10 +553,12 @@ fn make_data(
     html_config: &HtmlConfig,
 ) -> Result<serde_json::Map<String, serde_json::Value>> {
     trace!("make_data");
-    let html = config.html_config().unwrap_or_default();
 
     let mut data = serde_json::Map::new();
-    data.insert("language".to_owned(), json!("en"));
+    data.insert(
+        "language".to_owned(),
+        json!(config.book.language.clone().unwrap_or_default()),
+    );
     data.insert(
         "book_title".to_owned(),
         json!(config.book.title.clone().unwrap_or_default()),
@@ -390,24 +567,42 @@ fn make_data(
         "description".to_owned(),
         json!(config.book.description.clone().unwrap_or_default()),
     );
-    data.insert("favicon".to_owned(), json!("favicon.png"));
     if let Some(ref livereload) = html_config.livereload_url {
         data.insert("livereload".to_owned(), json!(livereload));
     }
 
+    let default_theme = match html_config.default_theme {
+        Some(ref theme) => theme.to_lowercase(),
+        None => "light".to_string(),
+    };
+    data.insert("default_theme".to_owned(), json!(default_theme));
+
+    let preferred_dark_theme = match html_config.preferred_dark_theme {
+        Some(ref theme) => theme.to_lowercase(),
+        None => "navy".to_string(),
+    };
+    data.insert(
+        "preferred_dark_theme".to_owned(),
+        json!(preferred_dark_theme),
+    );
+
     // Add google analytics tag
-    if let Some(ref ga) = config.html_config().and_then(|html| html.google_analytics) {
+    if let Some(ref ga) = html_config.google_analytics {
         data.insert("google_analytics".to_owned(), json!(ga));
     }
 
-    if html.mathjax_support {
+    if html_config.mathjax_support {
         data.insert("mathjax_support".to_owned(), json!(true));
     }
 
+    if html_config.copy_fonts {
+        data.insert("copy_fonts".to_owned(), json!(true));
+    }
+
     // Add check to see if there is an additional style
-    if !html.additional_css.is_empty() {
+    if !html_config.additional_css.is_empty() {
         let mut css = Vec::new();
-        for style in &html.additional_css {
+        for style in &html_config.additional_css {
             match style.strip_prefix(root) {
                 Ok(p) => css.push(p.to_str().expect("Could not convert to str")),
                 Err(_) => css.push(style.to_str().expect("Could not convert to str")),
@@ -417,26 +612,29 @@ fn make_data(
     }
 
     // Add check to see if there is an additional script
-    if !html.additional_js.is_empty() {
+    if !html_config.additional_js.is_empty() {
         let mut js = Vec::new();
-        for script in &html.additional_js {
+        for script in &html_config.additional_js {
             match script.strip_prefix(root) {
                 Ok(p) => js.push(p.to_str().expect("Could not convert to str")),
-                Err(_) => js.push(
-                    script
-                        .file_name()
-                        .expect("File has a file name")
-                        .to_str()
-                        .expect("Could not convert to str"),
-                ),
+                Err(_) => js.push(script.to_str().expect("Could not convert to str")),
             }
         }
         data.insert("additional_js".to_owned(), json!(js));
     }
 
-    if html.playpen.editable && html.playpen.copy_js {
-        data.insert("playpen_js".to_owned(), json!(true));
+    if html_config.playground.editable && html_config.playground.copy_js {
+        data.insert("playground_js".to_owned(), json!(true));
+        if html_config.playground.line_numbers {
+            data.insert("playground_line_numbers".to_owned(), json!(true));
+        }
     }
+    if html_config.playground.copyable {
+        data.insert("playground_copyable".to_owned(), json!(true));
+    }
+
+    data.insert("fold_enable".to_owned(), json!((html_config.fold.enable)));
+    data.insert("fold_level".to_owned(), json!((html_config.fold.level)));
 
     let search = html_config.search.clone();
     if cfg!(feature = "search") {
@@ -454,6 +652,16 @@ fn make_data(
         )
     }
 
+    if let Some(ref git_repository_url) = html_config.git_repository_url {
+        data.insert("git_repository_url".to_owned(), json!(git_repository_url));
+    }
+
+    let git_repository_icon = match html_config.git_repository_icon {
+        Some(ref git_repository_icon) => git_repository_icon,
+        None => "fa-github",
+    };
+    data.insert("git_repository_icon".to_owned(), json!(git_repository_icon));
+
     let mut chapters = vec![];
 
     for item in book.iter() {
@@ -461,17 +669,26 @@ fn make_data(
         let mut chapter = BTreeMap::new();
 
         match *item {
+            BookItem::PartTitle(ref title) => {
+                chapter.insert("part".to_owned(), json!(title));
+            }
             BookItem::Chapter(ref ch) => {
                 if let Some(ref section) = ch.number {
                     chapter.insert("section".to_owned(), json!(section.to_string()));
                 }
 
+                chapter.insert(
+                    "has_sub_items".to_owned(),
+                    json!((!ch.sub_items.is_empty()).to_string()),
+                );
+
                 chapter.insert("name".to_owned(), json!(ch.name));
-                let path = ch
-                    .path
-                    .to_str()
-                    .chain_err(|| "Could not convert path to str")?;
-                chapter.insert("path".to_owned(), json!(path));
+                if let Some(ref path) = ch.path {
+                    let p = path
+                        .to_str()
+                        .with_context(|| "Could not convert path to str")?;
+                    chapter.insert("path".to_owned(), json!(p));
+                }
             }
             BookItem::Separator => {
                 chapter.insert("spacer".to_owned(), json!("_spacer_"));
@@ -487,25 +704,26 @@ fn make_data(
     Ok(data)
 }
 
-/// Goes through the rendered HTML, making sure all header tags are wrapped in
-/// an anchor so people can link to sections directly.
+/// Goes through the rendered HTML, making sure all header tags have
+/// an anchor respectively so people can link to sections directly.
 fn build_header_links(html: &str) -> String {
     let regex = Regex::new(r"<h(\d)>(.*?)</h\d>").unwrap();
     let mut id_counter = HashMap::new();
 
     regex
-        .replace_all(html, |caps: &Captures| {
+        .replace_all(html, |caps: &Captures<'_>| {
             let level = caps[1]
                 .parse()
                 .expect("Regex should ensure we only ever get numbers here");
 
-            wrap_header_with_link(level, &caps[2], &mut id_counter)
-        }).into_owned()
+            insert_link_into_header(level, &caps[2], &mut id_counter)
+        })
+        .into_owned()
 }
 
-/// Wraps a single header tag with a link, making sure each tag gets its own
+/// Insert a sinle link into a header, making sure each link gets its own
 /// unique ID by appending an auto-incremented number (if necessary).
-fn wrap_header_with_link(
+fn insert_link_into_header(
     level: usize,
     content: &str,
     id_counter: &mut HashMap<String, usize>,
@@ -522,7 +740,7 @@ fn wrap_header_with_link(
     *id_count += 1;
 
     format!(
-        r##"<a class="header" href="#{id}" id="{id}"><h{level}>{text}</h{level}></a>"##,
+        r##"<h{level}><a class="header" href="#{id}" id="{id}">{text}</a></h{level}>"##,
         level = level,
         id = id,
         text = content
@@ -540,7 +758,7 @@ fn wrap_header_with_link(
 fn fix_code_blocks(html: &str) -> String {
     let regex = Regex::new(r##"<code([^>]+)class="([^"]+)"([^>]*)>"##).unwrap();
     regex
-        .replace_all(html, |caps: &Captures| {
+        .replace_all(html, |caps: &Captures<'_>| {
             let before = &caps[1];
             let classes = &caps[2].replace(",", " ");
             let after = &caps[3];
@@ -551,43 +769,107 @@ fn fix_code_blocks(html: &str) -> String {
                 classes = classes,
                 after = after
             )
-        }).into_owned()
+        })
+        .into_owned()
 }
 
-fn add_playpen_pre(html: &str, playpen_config: &Playpen) -> String {
+fn add_playground_pre(
+    html: &str,
+    playground_config: &Playground,
+    edition: Option<RustEdition>,
+) -> String {
     let regex = Regex::new(r##"((?s)<code[^>]?class="([^"]+)".*?>(.*?)</code>)"##).unwrap();
     regex
-        .replace_all(html, |caps: &Captures| {
+        .replace_all(html, |caps: &Captures<'_>| {
             let text = &caps[1];
             let classes = &caps[2];
             let code = &caps[3];
 
-            if (classes.contains("language-rust")
-                && !classes.contains("ignore")
-                && !classes.contains("noplaypen"))
-                || classes.contains("mdbook-runnable")
-            {
-                // wrap the contents in an external pre block
-                if playpen_config.editable && classes.contains("editable")
-                    || text.contains("fn main")
-                    || text.contains("quick_main!")
+            if classes.contains("language-rust") {
+                if (!classes.contains("ignore")
+                    && !classes.contains("noplayground")
+                    && !classes.contains("noplaypen"))
+                    || classes.contains("mdbook-runnable")
                 {
-                    format!("<pre class=\"playpen\">{}</pre>", text)
-                } else {
-                    // we need to inject our own main
-                    let (attrs, code) = partition_source(code);
+                    let contains_e2015 = classes.contains("edition2015");
+                    let contains_e2018 = classes.contains("edition2018");
+                    let edition_class = if contains_e2015 || contains_e2018 {
+                        // the user forced edition, we should not overwrite it
+                        ""
+                    } else {
+                        match edition {
+                            Some(RustEdition::E2015) => " edition2015",
+                            Some(RustEdition::E2018) => " edition2018",
+                            None => "",
+                        }
+                    };
 
+                    // wrap the contents in an external pre block
                     format!(
-                        "<pre class=\"playpen\"><code class=\"{}\">\n# \
-                         #![allow(unused_variables)]\n{}#fn main() {{\n{}#}}</code></pre>",
-                        classes, attrs, code
+                        "<pre class=\"playground\"><code class=\"{}{}\">{}</code></pre>",
+                        classes,
+                        edition_class,
+                        {
+                            let content: Cow<'_, str> = if playground_config.editable
+                                && classes.contains("editable")
+                                || text.contains("fn main")
+                                || text.contains("quick_main!")
+                            {
+                                code.into()
+                            } else {
+                                // we need to inject our own main
+                                let (attrs, code) = partition_source(code);
+
+                                format!(
+                                    "\n# #![allow(unused)]\n{}#fn main() {{\n{}#}}",
+                                    attrs, code
+                                )
+                                .into()
+                            };
+                            hide_lines(&content)
+                        }
                     )
+                } else {
+                    format!("<code class=\"{}\">{}</code>", classes, hide_lines(code))
                 }
             } else {
                 // not language-rust, so no-op
                 text.to_owned()
             }
-        }).into_owned()
+        })
+        .into_owned()
+}
+
+lazy_static! {
+    static ref BORING_LINES_REGEX: Regex = Regex::new(r"^(\s*)#(.?)(.*)$").unwrap();
+}
+
+fn hide_lines(content: &str) -> String {
+    let mut result = String::with_capacity(content.len());
+    for line in content.lines() {
+        if let Some(caps) = BORING_LINES_REGEX.captures(line) {
+            if &caps[2] == "#" {
+                result += &caps[1];
+                result += &caps[2];
+                result += &caps[3];
+                result += "\n";
+                continue;
+            } else if &caps[2] != "!" && &caps[2] != "[" {
+                result += "<span class=\"boring\">";
+                result += &caps[1];
+                if &caps[2] != " " {
+                    result += &caps[2];
+                }
+                result += &caps[3];
+                result += "\n";
+                result += "</span>";
+                continue;
+            }
+        }
+        result += line;
+        result += "\n";
+    }
+    result
 }
 
 fn partition_source(s: &str) -> (String, String) {
@@ -597,7 +879,7 @@ fn partition_source(s: &str) -> (String, String) {
 
     for line in s.lines() {
         let trimline = line.trim();
-        let header = trimline.chars().all(|c| c.is_whitespace()) || trimline.starts_with("#![");
+        let header = trimline.chars().all(char::is_whitespace) || trimline.starts_with("#![");
         if !header || after_header {
             after_header = true;
             after.push_str(line);
@@ -612,11 +894,12 @@ fn partition_source(s: &str) -> (String, String) {
 }
 
 struct RenderItemContext<'a> {
-    handlebars: &'a Handlebars,
+    handlebars: &'a Handlebars<'a>,
     destination: PathBuf,
     data: serde_json::Map<String, serde_json::Value>,
     is_index: bool,
     html_config: HtmlConfig,
+    edition: Option<RustEdition>,
 }
 
 #[cfg(test)]
@@ -628,27 +911,27 @@ mod tests {
         let inputs = vec![
             (
                 "blah blah <h1>Foo</h1>",
-                r##"blah blah <a class="header" href="#foo" id="foo"><h1>Foo</h1></a>"##,
+                r##"blah blah <h1><a class="header" href="#foo" id="foo">Foo</a></h1>"##,
             ),
             (
                 "<h1>Foo</h1>",
-                r##"<a class="header" href="#foo" id="foo"><h1>Foo</h1></a>"##,
+                r##"<h1><a class="header" href="#foo" id="foo">Foo</a></h1>"##,
             ),
             (
                 "<h3>Foo^bar</h3>",
-                r##"<a class="header" href="#foobar" id="foobar"><h3>Foo^bar</h3></a>"##,
+                r##"<h3><a class="header" href="#foobar" id="foobar">Foo^bar</a></h3>"##,
             ),
             (
                 "<h4></h4>",
-                r##"<a class="header" href="#" id=""><h4></h4></a>"##,
+                r##"<h4><a class="header" href="#" id=""></a></h4>"##,
             ),
             (
                 "<h4><em>Hï</em></h4>",
-                r##"<a class="header" href="#hï" id="hï"><h4><em>Hï</em></h4></a>"##,
+                r##"<h4><a class="header" href="#hï" id="hï"><em>Hï</em></a></h4>"##,
             ),
             (
                 "<h1>Foo</h1><h3>Foo</h3>",
-                r##"<a class="header" href="#foo" id="foo"><h1>Foo</h1></a><a class="header" href="#foo-1" id="foo-1"><h3>Foo</h3></a>"##,
+                r##"<h1><a class="header" href="#foo" id="foo">Foo</a></h1><h3><a class="header" href="#foo-1" id="foo-1">Foo</a></h3>"##,
             ),
         ];
 
@@ -657,4 +940,83 @@ mod tests {
             assert_eq!(got, should_be);
         }
     }
+
+    #[test]
+    fn add_playground() {
+        let inputs = [
+          ("<code class=\"language-rust\">x()</code>",
+           "<pre class=\"playground\"><code class=\"language-rust\">\n<span class=\"boring\">#![allow(unused)]\n</span><span class=\"boring\">fn main() {\n</span>x()\n<span class=\"boring\">}\n</span></code></pre>"),
+          ("<code class=\"language-rust\">fn main() {}</code>",
+           "<pre class=\"playground\"><code class=\"language-rust\">fn main() {}\n</code></pre>"),
+          ("<code class=\"language-rust editable\">let s = \"foo\n # bar\n\";</code>",
+           "<pre class=\"playground\"><code class=\"language-rust editable\">let s = \"foo\n<span class=\"boring\"> bar\n</span>\";\n</code></pre>"),
+          ("<code class=\"language-rust editable\">let s = \"foo\n ## bar\n\";</code>",
+           "<pre class=\"playground\"><code class=\"language-rust editable\">let s = \"foo\n # bar\n\";\n</code></pre>"),
+          ("<code class=\"language-rust editable\">let s = \"foo\n # bar\n#\n\";</code>",
+           "<pre class=\"playground\"><code class=\"language-rust editable\">let s = \"foo\n<span class=\"boring\"> bar\n</span><span class=\"boring\">\n</span>\";\n</code></pre>"),
+          ("<code class=\"language-rust ignore\">let s = \"foo\n # bar\n\";</code>",
+           "<code class=\"language-rust ignore\">let s = \"foo\n<span class=\"boring\"> bar\n</span>\";\n</code>"),
+          ("<code class=\"language-rust editable\">#![no_std]\nlet s = \"foo\";\n #[some_attr]</code>",
+           "<pre class=\"playground\"><code class=\"language-rust editable\">#![no_std]\nlet s = \"foo\";\n #[some_attr]\n</code></pre>"),
+        ];
+        for (src, should_be) in &inputs {
+            let got = add_playground_pre(
+                src,
+                &Playground {
+                    editable: true,
+                    ..Playground::default()
+                },
+                None,
+            );
+            assert_eq!(&*got, *should_be);
+        }
+    }
+    #[test]
+    fn add_playground_edition2015() {
+        let inputs = [
+          ("<code class=\"language-rust\">x()</code>",
+           "<pre class=\"playground\"><code class=\"language-rust edition2015\">\n<span class=\"boring\">#![allow(unused)]\n</span><span class=\"boring\">fn main() {\n</span>x()\n<span class=\"boring\">}\n</span></code></pre>"),
+          ("<code class=\"language-rust\">fn main() {}</code>",
+           "<pre class=\"playground\"><code class=\"language-rust edition2015\">fn main() {}\n</code></pre>"),
+          ("<code class=\"language-rust edition2015\">fn main() {}</code>",
+           "<pre class=\"playground\"><code class=\"language-rust edition2015\">fn main() {}\n</code></pre>"),
+          ("<code class=\"language-rust edition2018\">fn main() {}</code>",
+           "<pre class=\"playground\"><code class=\"language-rust edition2018\">fn main() {}\n</code></pre>"),
+        ];
+        for (src, should_be) in &inputs {
+            let got = add_playground_pre(
+                src,
+                &Playground {
+                    editable: true,
+                    ..Playground::default()
+                },
+                Some(RustEdition::E2015),
+            );
+            assert_eq!(&*got, *should_be);
+        }
+    }
+    #[test]
+    fn add_playground_edition2018() {
+        let inputs = [
+          ("<code class=\"language-rust\">x()</code>",
+           "<pre class=\"playground\"><code class=\"language-rust edition2018\">\n<span class=\"boring\">#![allow(unused)]\n</span><span class=\"boring\">fn main() {\n</span>x()\n<span class=\"boring\">}\n</span></code></pre>"),
+          ("<code class=\"language-rust\">fn main() {}</code>",
+           "<pre class=\"playground\"><code class=\"language-rust edition2018\">fn main() {}\n</code></pre>"),
+          ("<code class=\"language-rust edition2015\">fn main() {}</code>",
+           "<pre class=\"playground\"><code class=\"language-rust edition2015\">fn main() {}\n</code></pre>"),
+          ("<code class=\"language-rust edition2018\">fn main() {}</code>",
+           "<pre class=\"playground\"><code class=\"language-rust edition2018\">fn main() {}\n</code></pre>"),
+        ];
+        for (src, should_be) in &inputs {
+            let got = add_playground_pre(
+                src,
+                &Playground {
+                    editable: true,
+                    ..Playground::default()
+                },
+                Some(RustEdition::E2018),
+            );
+            assert_eq!(&*got, *should_be);
+        }
+    }
 }

src/renderer/html_handlebars/helpers/mod.rs

@@ -1,2 +1,3 @@
 pub mod navigation;
+pub mod theme;
 pub mod toc;

src/renderer/html_handlebars/helpers/navigation.rs

@@ -2,9 +2,8 @@ use std::collections::BTreeMap;
 use std::path::Path;
 
 use handlebars::{Context, Handlebars, Helper, Output, RenderContext, RenderError, Renderable};
-use serde_json;
 
-use utils;
+use crate::utils;
 
 type StringMap = BTreeMap<String, String>;
 
@@ -18,13 +17,13 @@ impl Target {
     /// Returns target if found.
     fn find(
         &self,
-        base_path: &String,
-        current_path: &String,
+        base_path: &str,
+        current_path: &str,
         current_item: &StringMap,
         previous_item: &StringMap,
     ) -> Result<Option<StringMap>, RenderError> {
-        match self {
-            &Target::Next => {
+        match *self {
+            Target::Next => {
                 let previous_path = previous_item
                     .get("path")
                     .ok_or_else(|| RenderError::new("No path found for chapter in JSON data"))?;
@@ -34,7 +33,7 @@ impl Target {
                 }
             }
 
-            &Target::Previous => {
+            Target::Previous => {
                 if current_path == base_path {
                     return Ok(Some(previous_item.clone()));
                 }
@@ -47,22 +46,43 @@ impl Target {
 
 fn find_chapter(
     ctx: &Context,
-    rc: &mut RenderContext,
+    rc: &mut RenderContext<'_, '_>,
     target: Target,
 ) -> Result<Option<StringMap>, RenderError> {
     debug!("Get data from context");
 
-    let chapters = rc.evaluate_absolute(ctx, "chapters", true).and_then(|c| {
-        serde_json::value::from_value::<Vec<StringMap>>(c.clone())
+    let chapters = rc.evaluate(ctx, "@root/chapters").and_then(|c| {
+        serde_json::value::from_value::<Vec<StringMap>>(c.as_json().clone())
             .map_err(|_| RenderError::new("Could not decode the JSON data"))
     })?;
 
     let base_path = rc
-        .evaluate_absolute(ctx, "path", true)?
+        .evaluate(ctx, "@root/path")?
+        .as_json()
         .as_str()
         .ok_or_else(|| RenderError::new("Type error for `path`, string expected"))?
         .replace("\"", "");
 
+    if !rc.evaluate(ctx, "@root/is_index")?.is_missing() {
+        // Special case for index.md which may be a synthetic page.
+        // Target::find won't match because there is no page with the path
+        // "index.md" (unless there really is an index.md in SUMMARY.md).
+        match target {
+            Target::Previous => return Ok(None),
+            Target::Next => match chapters
+                .iter()
+                .filter(|chapter| {
+                    // Skip things like "spacer"
+                    chapter.contains_key("path")
+                })
+                .nth(1)
+            {
+                Some(chapter) => return Ok(Some(chapter.clone())),
+                None => return Ok(None),
+            },
+        }
+    }
+
     let mut previous: Option<StringMap> = None;
 
     debug!("Search for chapter");
@@ -86,18 +106,19 @@ fn find_chapter(
 }
 
 fn render(
-    _h: &Helper,
-    r: &Handlebars,
+    _h: &Helper<'_, '_>,
+    r: &Handlebars<'_>,
     ctx: &Context,
-    rc: &mut RenderContext,
-    out: &mut Output,
+    rc: &mut RenderContext<'_, '_>,
+    out: &mut dyn Output,
     chapter: &StringMap,
 ) -> Result<(), RenderError> {
     trace!("Creating BTreeMap to inject in context");
 
     let mut context = BTreeMap::new();
     let base_path = rc
-        .evaluate_absolute(ctx, "path", false)?
+        .evaluate(ctx, "@root/path")?
+        .as_json()
         .as_str()
         .ok_or_else(|| RenderError::new("Type error for `path`, string expected"))?
         .replace("\"", "");
@@ -128,7 +149,7 @@ fn render(
     _h.template()
         .ok_or_else(|| RenderError::new("Error with the handlebars template"))
         .and_then(|t| {
-            let mut local_rc = rc.new_for_block();
+            let mut local_rc = rc.clone();
             let local_ctx = Context::wraps(&context)?;
             t.render(r, &local_ctx, &mut local_rc, out)
         })?;
@@ -137,11 +158,11 @@ fn render(
 }
 
 pub fn previous(
-    _h: &Helper,
-    r: &Handlebars,
+    _h: &Helper<'_, '_>,
+    r: &Handlebars<'_>,
     ctx: &Context,
-    rc: &mut RenderContext,
-    out: &mut Output,
+    rc: &mut RenderContext<'_, '_>,
+    out: &mut dyn Output,
 ) -> Result<(), RenderError> {
     trace!("previous (handlebars helper)");
 
@@ -153,11 +174,11 @@ pub fn previous(
 }
 
 pub fn next(
-    _h: &Helper,
-    r: &Handlebars,
+    _h: &Helper<'_, '_>,
+    r: &Handlebars<'_>,
     ctx: &Context,
-    rc: &mut RenderContext,
-    out: &mut Output,
+    rc: &mut RenderContext<'_, '_>,
+    out: &mut dyn Output,
 ) -> Result<(), RenderError> {
     trace!("next (handlebars helper)");
 
@@ -172,29 +193,29 @@ pub fn next(
 mod tests {
     use super::*;
 
-    static TEMPLATE: &'static str =
+    static TEMPLATE: &str =
         "{{#previous}}{{title}}: {{link}}{{/previous}}|{{#next}}{{title}}: {{link}}{{/next}}";
 
     #[test]
     fn test_next_previous() {
         let data = json!({
-         "name": "two",
-         "path": "two.path",
-         "chapters": [
-            {
-               "name": "one",
-               "path": "one.path"
-            },
-            {
-               "name": "two",
-               "path": "two.path",
-            },
-            {
-               "name": "three",
-               "path": "three.path"
-            }
-         ]
-      });
+           "name": "two",
+           "path": "two.path",
+           "chapters": [
+              {
+                 "name": "one",
+                 "path": "one.path"
+              },
+              {
+                 "name": "two",
+                 "path": "two.path",
+              },
+              {
+                 "name": "three",
+                 "path": "three.path"
+              }
+           ]
+        });
 
         let mut h = Handlebars::new();
         h.register_helper("previous", Box::new(previous));
@@ -209,23 +230,23 @@ mod tests {
     #[test]
     fn test_first() {
         let data = json!({
-         "name": "one",
-         "path": "one.path",
-         "chapters": [
-            {
-               "name": "one",
-               "path": "one.path"
-            },
-            {
-               "name": "two",
-               "path": "two.path",
-            },
-            {
-               "name": "three",
-               "path": "three.path"
-            }
-         ]
-      });
+           "name": "one",
+           "path": "one.path",
+           "chapters": [
+              {
+                 "name": "one",
+                 "path": "one.path"
+              },
+              {
+                 "name": "two",
+                 "path": "two.path",
+              },
+              {
+                 "name": "three",
+                 "path": "three.path"
+              }
+           ]
+        });
 
         let mut h = Handlebars::new();
         h.register_helper("previous", Box::new(previous));
@@ -239,23 +260,23 @@ mod tests {
     #[test]
     fn test_last() {
         let data = json!({
-         "name": "three",
-         "path": "three.path",
-         "chapters": [
-            {
-               "name": "one",
-               "path": "one.path"
-            },
-            {
-               "name": "two",
-               "path": "two.path",
-            },
-            {
-               "name": "three",
-               "path": "three.path"
-            }
-         ]
-      });
+           "name": "three",
+           "path": "three.path",
+           "chapters": [
+              {
+                 "name": "one",
+                 "path": "one.path"
+              },
+              {
+                 "name": "two",
+                 "path": "two.path",
+              },
+              {
+                 "name": "three",
+                 "path": "three.path"
+              }
+           ]
+        });
 
         let mut h = Handlebars::new();
         h.register_helper("previous", Box::new(previous));

src/renderer/html_handlebars/helpers/theme.rs

@@ -0,0 +1,28 @@
+use handlebars::{Context, Handlebars, Helper, Output, RenderContext, RenderError};
+
+pub fn theme_option(
+    h: &Helper<'_, '_>,
+    _r: &Handlebars<'_>,
+    ctx: &Context,
+    rc: &mut RenderContext<'_, '_>,
+    out: &mut dyn Output,
+) -> Result<(), RenderError> {
+    trace!("theme_option (handlebars helper)");
+
+    let param = h.param(0).and_then(|v| v.value().as_str()).ok_or_else(|| {
+        RenderError::new("Param 0 with String type is required for theme_option helper.")
+    })?;
+
+    let default_theme = rc.evaluate(ctx, "@root/default_theme")?;
+    let default_theme_name = default_theme
+        .as_json()
+        .as_str()
+        .ok_or_else(|| RenderError::new("Type error for `default_theme`, string expected"))?;
+
+    out.write(param)?;
+    if param.to_lowercase() == default_theme_name.to_lowercase() {
+        out.write(" (default)")?;
+    }
+
+    Ok(())
+}

src/renderer/html_handlebars/helpers/toc.rs

@@ -1,11 +1,10 @@
 use std::collections::BTreeMap;
 use std::path::Path;
 
-use utils;
+use crate::utils;
 
 use handlebars::{Context, Handlebars, Helper, HelperDef, Output, RenderContext, RenderError};
-use pulldown_cmark::{html, Event, Parser, Tag};
-use serde_json;
+use pulldown_cmark::{html, Event, Parser};
 
 // Handlebars helper to construct TOC
 #[derive(Clone, Copy)]
@@ -16,25 +15,45 @@ pub struct RenderToc {
 impl HelperDef for RenderToc {
     fn call<'reg: 'rc, 'rc>(
         &self,
-        _h: &Helper,
-        _: &Handlebars,
-        ctx: &Context,
-        rc: &mut RenderContext,
-        out: &mut Output,
+        _h: &Helper<'reg, 'rc>,
+        _r: &'reg Handlebars<'_>,
+        ctx: &'rc Context,
+        rc: &mut RenderContext<'reg, 'rc>,
+        out: &mut dyn Output,
     ) -> Result<(), RenderError> {
         // get value from context data
         // rc.get_path() is current json parent path, you should always use it like this
         // param is the key of value you want to display
-        let chapters = rc.evaluate_absolute(ctx, "chapters", true).and_then(|c| {
-            serde_json::value::from_value::<Vec<BTreeMap<String, String>>>(c.clone())
+        let chapters = rc.evaluate(ctx, "@root/chapters").and_then(|c| {
+            serde_json::value::from_value::<Vec<BTreeMap<String, String>>>(c.as_json().clone())
                 .map_err(|_| RenderError::new("Could not decode the JSON data"))
         })?;
-        let current = rc
-            .evaluate_absolute(ctx, "path", true)?
+        let current_path = rc
+            .evaluate(ctx, "@root/path")?
+            .as_json()
             .as_str()
             .ok_or_else(|| RenderError::new("Type error for `path`, string expected"))?
             .replace("\"", "");
 
+        let current_section = rc
+            .evaluate(ctx, "@root/section")?
+            .as_json()
+            .as_str()
+            .map(str::to_owned)
+            .unwrap_or_default();
+
+        let fold_enable = rc
+            .evaluate(ctx, "@root/fold_enable")?
+            .as_json()
+            .as_bool()
+            .ok_or_else(|| RenderError::new("Type error for `fold_enable`, bool expected"))?;
+
+        let fold_level = rc
+            .evaluate(ctx, "@root/fold_level")?
+            .as_json()
+            .as_u64()
+            .ok_or_else(|| RenderError::new("Type error for `fold_level`, u64 expected"))?;
+
         out.write("<ol class=\"chapter\">")?;
 
         let mut current_level = 1;
@@ -46,32 +65,46 @@ impl HelperDef for RenderToc {
                 continue;
             }
 
-            let level = if let Some(s) = item.get("section") {
-                s.matches('.').count()
+            let (section, level) = if let Some(s) = item.get("section") {
+                (s.as_str(), s.matches('.').count())
             } else {
-                1
+                ("", 1)
             };
 
+            let is_expanded =
+                if !fold_enable || (!section.is_empty() && current_section.starts_with(section)) {
+                    // Expand if folding is disabled, or if the section is an
+                    // ancestor or the current section itself.
+                    true
+                } else {
+                    // Levels that are larger than this would be folded.
+                    level - 1 < fold_level as usize
+                };
+
             if level > current_level {
                 while level > current_level {
                     out.write("<li>")?;
                     out.write("<ol class=\"section\">")?;
                     current_level += 1;
                 }
-                out.write("<li>")?;
+                write_li_open_tag(out, is_expanded, false)?;
             } else if level < current_level {
                 while level < current_level {
                     out.write("</ol>")?;
                     out.write("</li>")?;
                     current_level -= 1;
                 }
-                out.write("<li>")?;
+                write_li_open_tag(out, is_expanded, false)?;
             } else {
-                out.write("<li")?;
-                if item.get("section").is_none() {
-                    out.write(" class=\"affix\"")?;
-                }
-                out.write(">")?;
+                write_li_open_tag(out, is_expanded, item.get("section").is_none())?;
+            }
+
+            // Part title
+            if let Some(title) = item.get("part") {
+                out.write("<li class=\"part-title\">")?;
+                out.write(title)?;
+                out.write("</li>")?;
+                continue;
             }
 
             // Link
@@ -87,11 +120,11 @@ impl HelperDef for RenderToc {
                         .replace("\\", "/");
 
                     // Add link
-                    out.write(&utils::fs::path_to_root(&current))?;
+                    out.write(&utils::fs::path_to_root(&current_path))?;
                     out.write(&tmp)?;
                     out.write("\"")?;
 
-                    if path == &current {
+                    if path == &current_path {
                         out.write(" class=\"active\"")?;
                     }
 
@@ -118,10 +151,7 @@ impl HelperDef for RenderToc {
 
                 // filter all events that are not inline code blocks
                 let parser = Parser::new(name).filter(|event| match *event {
-                    Event::Start(Tag::Code)
-                    | Event::End(Tag::Code)
-                    | Event::InlineHtml(_)
-                    | Event::Text(_) => true,
+                    Event::Code(_) | Event::Html(_) | Event::Text(_) => true,
                     _ => false,
                 });
 
@@ -137,6 +167,13 @@ impl HelperDef for RenderToc {
                 out.write("</a>")?;
             }
 
+            // Render expand/collapse toggle
+            if let Some(flag) = item.get("has_sub_items") {
+                let has_sub_items = flag.parse::<bool>().unwrap_or_default();
+                if fold_enable && has_sub_items {
+                    out.write("<a class=\"toggle\"><div>❱</div></a>")?;
+                }
+            }
             out.write("</li>")?;
         }
         while current_level > 1 {
@@ -149,3 +186,19 @@ impl HelperDef for RenderToc {
         Ok(())
     }
 }
+
+fn write_li_open_tag(
+    out: &mut dyn Output,
+    is_expanded: bool,
+    is_affix: bool,
+) -> Result<(), std::io::Error> {
+    let mut li = String::from("<li class=\"chapter-item ");
+    if is_expanded {
+        li.push_str("expanded ");
+    }
+    if is_affix {
+        li.push_str("affix ");
+    }
+    li.push_str("\">");
+    out.write(&li)
+}

src/renderer/html_handlebars/search.rs

@@ -1,19 +1,15 @@
-extern crate ammonia;
-extern crate elasticlunr;
-
 use std::borrow::Cow;
 use std::collections::{HashMap, HashSet};
 use std::path::Path;
 
-use self::elasticlunr::Index;
+use elasticlunr::Index;
 use pulldown_cmark::*;
-use serde_json;
 
-use book::{Book, BookItem};
-use config::Search;
-use errors::*;
-use theme::searcher;
-use utils;
+use crate::book::{Book, BookItem};
+use crate::config::Search;
+use crate::errors::*;
+use crate::theme::searcher;
+use crate::utils;
 
 /// Creates all files required for search.
 pub fn create_files(search_config: &Search, destination: &Path, book: &Book) -> Result<()> {
@@ -35,7 +31,7 @@ pub fn create_files(search_config: &Search, destination: &Path, book: &Book) ->
         utils::fs::write_file(
             destination,
             "searchindex.js",
-            format!("window.search = {};", index).as_bytes(),
+            format!("Object.assign(window.search, {});", index).as_bytes(),
         )?;
         utils::fs::write_file(destination, "searcher.js", searcher::JS)?;
         utils::fs::write_file(destination, "mark.min.js", searcher::MARK_JS)?;
@@ -54,7 +50,7 @@ fn add_doc(
     section_id: &Option<String>,
     items: &[&str],
 ) {
-    let url = if let &Some(ref id) = section_id {
+    let url = if let Some(ref id) = *section_id {
         Cow::Owned(format!("{}#{}", anchor_base, id))
     } else {
         Cow::Borrowed(anchor_base)
@@ -74,35 +70,36 @@ fn render_item(
     doc_urls: &mut Vec<String>,
     item: &BookItem,
 ) -> Result<()> {
-    let chapter = match item {
-        &BookItem::Chapter(ref ch) => ch,
+    let chapter = match *item {
+        BookItem::Chapter(ref ch) if !ch.is_draft_chapter() => ch,
         _ => return Ok(()),
     };
 
-    let filepath = Path::new(&chapter.path).with_extension("html");
+    let chapter_path = chapter
+        .path
+        .as_ref()
+        .expect("Checked that path exists above");
+    let filepath = Path::new(&chapter_path).with_extension("html");
     let filepath = filepath
         .to_str()
-        .chain_err(|| "Could not convert HTML path to str")?;
+        .with_context(|| "Could not convert HTML path to str")?;
     let anchor_base = utils::fs::normalize_path(filepath);
 
-    let mut opts = Options::empty();
-    opts.insert(OPTION_ENABLE_TABLES);
-    opts.insert(OPTION_ENABLE_FOOTNOTES);
-    let p = Parser::new_ext(&chapter.content, opts);
+    let mut p = utils::new_cmark_parser(&chapter.content).peekable();
 
-    let mut in_header = false;
-    let max_section_depth = search_config.heading_split_level as i32;
+    let mut in_heading = false;
+    let max_section_depth = u32::from(search_config.heading_split_level);
     let mut section_id = None;
     let mut heading = String::new();
     let mut body = String::new();
     let mut breadcrumbs = chapter.parent_names.clone();
     let mut footnote_numbers = HashMap::new();
 
-    for event in p {
+    while let Some(event) = p.next() {
         match event {
-            Event::Start(Tag::Header(i)) if i <= max_section_depth => {
-                if heading.len() > 0 {
-                    // Section finished, the next header is following now
+            Event::Start(Tag::Heading(i)) if i <= max_section_depth => {
+                if !heading.is_empty() {
+                    // Section finished, the next heading is following now
                     // Write the data to the index, and clear it for the next section
                     add_doc(
                         index,
@@ -117,10 +114,10 @@ fn render_item(
                     breadcrumbs.pop();
                 }
 
-                in_header = true;
+                in_heading = true;
             }
-            Event::End(Tag::Header(i)) if i <= max_section_depth => {
-                in_header = false;
+            Event::End(Tag::Heading(i)) if i <= max_section_depth => {
+                in_heading = false;
                 section_id = Some(utils::id_from_content(&heading));
                 breadcrumbs.push(heading.clone());
             }
@@ -128,34 +125,45 @@ fn render_item(
                 let number = footnote_numbers.len() + 1;
                 footnote_numbers.entry(name).or_insert(number);
             }
-            Event::Start(_) | Event::End(_) | Event::SoftBreak | Event::HardBreak => {
+            Event::Html(html) => {
+                let mut html_block = html.into_string();
+
+                // As of pulldown_cmark 0.6, html events are no longer contained
+                // in an HtmlBlock tag. We must collect consecutive Html events
+                // into a block ourselves.
+                while let Some(Event::Html(html)) = p.peek() {
+                    html_block.push_str(&html);
+                    p.next();
+                }
+
+                body.push_str(&clean_html(&html_block));
+            }
+            Event::Start(_) | Event::End(_) | Event::Rule | Event::SoftBreak | Event::HardBreak => {
                 // Insert spaces where HTML output would usually seperate text
                 // to ensure words don't get merged together
-                if in_header {
+                if in_heading {
                     heading.push(' ');
                 } else {
                     body.push(' ');
                 }
             }
-            Event::Text(text) => {
-                if in_header {
+            Event::Text(text) | Event::Code(text) => {
+                if in_heading {
                     heading.push_str(&text);
                 } else {
                     body.push_str(&text);
                 }
             }
-            Event::Html(html) | Event::InlineHtml(html) => {
-                body.push_str(&clean_html(&html));
-            }
             Event::FootnoteReference(name) => {
                 let len = footnote_numbers.len() + 1;
                 let number = footnote_numbers.entry(name).or_insert(len);
                 body.push_str(&format!(" [{}] ", number));
             }
+            Event::TaskListMarker(_checked) => {}
         }
     }
 
-    if heading.len() > 0 {
+    if !heading.is_empty() {
         // Make sure the last section is added to the index
         add_doc(
             index,
@@ -170,7 +178,7 @@ fn render_item(
 }
 
 fn write_to_json(index: Index, search_config: &Search, doc_urls: Vec<String>) -> Result<String> {
-    use self::elasticlunr::config::{SearchBool, SearchOptions, SearchOptionsField};
+    use elasticlunr::config::{SearchBool, SearchOptions, SearchOptionsField};
     use std::collections::BTreeMap;
 
     #[derive(Serialize)]

src/renderer/markdown_renderer.rs

@@ -0,0 +1,52 @@
+use crate::book::BookItem;
+use crate::errors::*;
+use crate::renderer::{RenderContext, Renderer};
+use crate::utils;
+
+use std::fs;
+
+#[derive(Default)]
+/// A renderer to output the Markdown after the preprocessors have run. Mostly useful
+/// when debugging preprocessors.
+pub struct MarkdownRenderer;
+
+impl MarkdownRenderer {
+    /// Create a new `MarkdownRenderer` instance.
+    pub fn new() -> Self {
+        MarkdownRenderer
+    }
+}
+
+impl Renderer for MarkdownRenderer {
+    fn name(&self) -> &str {
+        "markdown"
+    }
+
+    fn render(&self, ctx: &RenderContext) -> Result<()> {
+        let destination = &ctx.destination;
+        let book = &ctx.book;
+
+        if destination.exists() {
+            utils::fs::remove_dir_content(destination)
+                .with_context(|| "Unable to remove stale Markdown output")?;
+        }
+
+        trace!("markdown render");
+        for item in book.iter() {
+            if let BookItem::Chapter(ref ch) = *item {
+                if !ch.is_draft_chapter() {
+                    utils::fs::write_file(
+                        &ctx.destination,
+                        &ch.path.as_ref().expect("Checked path exists before"),
+                        ch.content.as_bytes(),
+                    )?;
+                }
+            }
+        }
+
+        fs::create_dir_all(&destination)
+            .with_context(|| "Unexpected error when constructing destination path")?;
+
+        Ok(())
+    }
+}

src/renderer/mod.rs

@@ -8,23 +8,25 @@
 //!
 //! The definition for [RenderContext] may be useful though.
 //!
-//! [For Developers]: https://rust-lang-nursery.github.io/mdBook/lib/index.html
+//! [For Developers]: https://rust-lang.github.io/mdBook/for_developers/index.html
 //! [RenderContext]: struct.RenderContext.html
 
 pub use self::html_handlebars::HtmlHandlebars;
+pub use self::markdown_renderer::MarkdownRenderer;
 
 mod html_handlebars;
+mod markdown_renderer;
 
-use serde_json;
 use shlex::Shlex;
 use std::fs;
-use std::io::{self, Read};
+use std::io::{self, ErrorKind, Read};
 use std::path::PathBuf;
 use std::process::{Command, Stdio};
 
-use book::Book;
-use config::Config;
-use errors::*;
+use crate::book::Book;
+use crate::config::Config;
+use crate::errors::*;
+use toml::Value;
 
 /// An arbitrary `mdbook` backend.
 ///
@@ -64,6 +66,7 @@ pub struct RenderContext {
     /// renderers to cache intermediate results, this directory is not
     /// guaranteed to be empty or even exist.
     pub destination: PathBuf,
+    #[serde(skip)]
     __non_exhaustive: (),
 }
 
@@ -75,9 +78,9 @@ impl RenderContext {
         Q: Into<PathBuf>,
     {
         RenderContext {
-            book: book,
-            config: config,
-            version: ::MDBOOK_VERSION.to_string(),
+            book,
+            config,
+            version: crate::MDBOOK_VERSION.to_string(),
             root: root.into(),
             destination: destination.into(),
             __non_exhaustive: (),
@@ -91,7 +94,7 @@ impl RenderContext {
 
     /// Load a `RenderContext` from its JSON representation.
     pub fn from_json<R: Read>(reader: R) -> Result<RenderContext> {
-        serde_json::from_reader(reader).chain_err(|| "Unable to deserialize the `RenderContext`")
+        serde_json::from_reader(reader).with_context(|| "Unable to deserialize the `RenderContext`")
     }
 }
 
@@ -147,6 +150,38 @@ impl CmdRenderer {
     }
 }
 
+impl CmdRenderer {
+    fn handle_render_command_error(&self, ctx: &RenderContext, error: io::Error) -> Result<()> {
+        if let ErrorKind::NotFound = error.kind() {
+            // Look for "output.{self.name}.optional".
+            // If it exists and is true, treat this as a warning.
+            // Otherwise, fail the build.
+
+            let optional_key = format!("output.{}.optional", self.name);
+
+            let is_optional = match ctx.config.get(&optional_key) {
+                Some(Value::Boolean(value)) => *value,
+                _ => false,
+            };
+
+            if is_optional {
+                warn!(
+                    "The command `{}` for backend `{}` was not found, \
+                    but was marked as optional.",
+                    self.cmd, self.name
+                );
+                return Ok(());
+            } else {
+                error!(
+                    "The command `{}` wasn't found, is the `{}` backend installed?",
+                    self.cmd, self.name
+                );
+            }
+        }
+        Err(error).with_context(|| "Unable to start the backend")?
+    }
+}
+
 impl Renderer for CmdRenderer {
     fn name(&self) -> &str {
         &self.name
@@ -166,34 +201,22 @@ impl Renderer for CmdRenderer {
             .spawn()
         {
             Ok(c) => c,
-            Err(ref e) if e.kind() == io::ErrorKind::NotFound => {
-                warn!(
-                    "The command wasn't found, is the \"{}\" backend installed?",
-                    self.name
-                );
-                warn!("\tCommand: {}", self.cmd);
-                return Ok(());
-            }
-            Err(e) => {
-                return Err(e).chain_err(|| "Unable to start the backend")?;
-            }
+            Err(e) => return self.handle_render_command_error(ctx, e),
         };
 
-        {
-            let mut stdin = child.stdin.take().expect("Child has stdin");
-            if let Err(e) = serde_json::to_writer(&mut stdin, &ctx) {
-                // Looks like the backend hung up before we could finish
-                // sending it the render context. Log the error and keep going
-                warn!("Error writing the RenderContext to the backend, {}", e);
-            }
-
-            // explicitly close the `stdin` file handle
-            drop(stdin);
+        let mut stdin = child.stdin.take().expect("Child has stdin");
+        if let Err(e) = serde_json::to_writer(&mut stdin, &ctx) {
+            // Looks like the backend hung up before we could finish
+            // sending it the render context. Log the error and keep going
+            warn!("Error writing the RenderContext to the backend, {}", e);
         }
 
+        // explicitly close the `stdin` file handle
+        drop(stdin);
+
         let status = child
             .wait()
-            .chain_err(|| "Error waiting for the backend to complete")?;
+            .with_context(|| "Error waiting for the backend to complete")?;
 
         trace!("{} exited with output: {:?}", self.cmd, status);
 

src/theme/ayu-highlight.css

@@ -12,8 +12,7 @@ Original by Dempfi (https://github.com/dempfi/ayu)
 }
 
 .hljs-comment,
-.hljs-quote,
-.hljs-meta {
+.hljs-quote {
   color: #5c6773;
   font-style: italic;
 }
@@ -30,6 +29,7 @@ Original by Dempfi (https://github.com/dempfi/ayu)
 }
 
 .hljs-number,
+.hljs-meta,
 .hljs-builtin-name,
 .hljs-literal,
 .hljs-type,
@@ -69,3 +69,11 @@ Original by Dempfi (https://github.com/dempfi/ayu)
 .hljs-strong {
   font-weight: bold;
 }
+
+.hljs-addition {
+  color: #91b362;
+}
+
+.hljs-deletion {
+  color: #d96c75;
+}

src/theme/book.js

@@ -4,8 +4,8 @@
 window.onunload = function () { };
 
 // Global variable, shared between modules
-function playpen_text(playpen) {
-    let code_block = playpen.querySelector("code");
+function playground_text(playground) {
+    let code_block = playground.querySelector("code");
 
     if (window.ace && code_block.classList.contains("editable")) {
         let editor = window.ace.edit(code_block);
@@ -16,9 +16,6 @@ function playpen_text(playpen) {
 }
 
 (function codeSnippets() {
-    // Hide Rust code lines prepended with a specific character
-    var hiding_character = "#";
-
     function fetch_with_timeout(url, options, timeout = 6000) {
         return Promise.race([
             fetch(url, options),
@@ -26,8 +23,8 @@ function playpen_text(playpen) {
         ]);
     }
 
-    var playpens = Array.from(document.querySelectorAll(".playpen"));
-    if (playpens.length > 0) {
+    var playgrounds = Array.from(document.querySelectorAll(".playground"));
+    if (playgrounds.length > 0) {
         fetch_with_timeout("https://play.rust-lang.org/meta/crates", {
             headers: {
                 'Content-Type': "application/json",
@@ -39,21 +36,30 @@ function playpen_text(playpen) {
         .then(response => {
             // get list of crates available in the rust playground
             let playground_crates = response.crates.map(item => item["id"]);
-            playpens.forEach(block => handle_crate_list_update(block, playground_crates));
+            playgrounds.forEach(block => handle_crate_list_update(block, playground_crates));
         });
     }
 
-    function handle_crate_list_update(playpen_block, playground_crates) {
+    function handle_crate_list_update(playground_block, playground_crates) {
         // update the play buttons after receiving the response
-        update_play_button(playpen_block, playground_crates);
+        update_play_button(playground_block, playground_crates);
 
         // and install on change listener to dynamically update ACE editors
         if (window.ace) {
-            let code_block = playpen_block.querySelector("code");
+            let code_block = playground_block.querySelector("code");
             if (code_block.classList.contains("editable")) {
                 let editor = window.ace.edit(code_block);
                 editor.addEventListener("change", function (e) {
-                    update_play_button(playpen_block, playground_crates);
+                    update_play_button(playground_block, playground_crates);
+                });
+                // add Ctrl-Enter command to execute rust code
+                editor.commands.addCommand({
+                    name: "run",
+                    bindKey: {
+                        win: "Ctrl-Enter",
+                        mac: "Ctrl-Enter"
+                    },
+                    exec: _editor => run_rust_code(playground_block)
                 });
             }
         }
@@ -71,7 +77,7 @@ function playpen_text(playpen) {
         }
 
         // get list of `extern crate`'s from snippet
-        var txt = playpen_text(pre_block);
+        var txt = playground_text(pre_block);
         var re = /extern\s+crate\s+([a-zA-Z_0-9]+)\s*;/g;
         var snippet_crates = [];
         var item;
@@ -100,12 +106,16 @@ function playpen_text(playpen) {
             code_block.append(result_block);
         }
 
-        let text = playpen_text(code_block);
+        let text = playground_text(code_block);
+        let classes = code_block.querySelector('code').classList;
+        let has_2018 = classes.contains("edition2018");
+        let edition = has_2018 ? "2018" : "2015";
 
         var params = {
             version: "stable",
             optimize: "0",
-            code: text
+            code: text,
+            edition: edition
         };
 
         if (text.indexOf("#![feature") !== -1) {
@@ -133,6 +143,11 @@ function playpen_text(playpen) {
         languages: [],      // Languages used for auto-detection
     });
 
+    let code_nodes = Array
+        .from(document.querySelectorAll('code'))
+        // Don't highlight `inline code` blocks in headers.
+        .filter(function (node) {return !node.parentElement.classList.contains("header"); });
+
     if (window.ace) {
         // language-rust class needs to be removed for editable
         // blocks or highlightjs will capture events
@@ -144,111 +159,71 @@ function playpen_text(playpen) {
             .from(document.querySelectorAll('code:not(.editable)'))
             .forEach(function (block) { hljs.highlightBlock(block); });
     } else {
-        Array
-            .from(document.querySelectorAll('code'))
-            .forEach(function (block) { hljs.highlightBlock(block); });
+        code_nodes.forEach(function (block) { hljs.highlightBlock(block); });
     }
 
     // Adding the hljs class gives code blocks the color css
     // even if highlighting doesn't apply
-    Array
-        .from(document.querySelectorAll('code'))
-        .forEach(function (block) { block.classList.add('hljs'); });
+    code_nodes.forEach(function (block) { block.classList.add('hljs'); });
 
     Array.from(document.querySelectorAll("code.language-rust")).forEach(function (block) {
 
-        var code_block = block;
-        var pre_block = block.parentNode;
-        // hide lines
-        var lines = code_block.innerHTML.split("\n");
-        var first_non_hidden_line = false;
-        var lines_hidden = false;
-        var trimmed_line = "";
-
-        for (var n = 0; n < lines.length; n++) {
-            trimmed_line = lines[n].trim();
-            if (trimmed_line[0] == hiding_character && trimmed_line[1] != hiding_character) {
-                if (first_non_hidden_line) {
-                    lines[n] = "<span class=\"hidden\">" + "\n" + lines[n].replace(/(\s*)# ?/, "$1") + "</span>";
-                }
-                else {
-                    lines[n] = "<span class=\"hidden\">" + lines[n].replace(/(\s*)# ?/, "$1") + "\n" + "</span>";
-                }
-                lines_hidden = true;
-            }
-            else if (first_non_hidden_line) {
-                lines[n] = "\n" + lines[n];
-            }
-            else {
-                first_non_hidden_line = true;
-            }
-            if (trimmed_line[0] == hiding_character && trimmed_line[1] == hiding_character) {
-                lines[n] = lines[n].replace("##", "#")
-            }
-        }
-        code_block.innerHTML = lines.join("");
-
+        var lines = Array.from(block.querySelectorAll('.boring'));
         // If no lines were hidden, return
-        if (!lines_hidden) { return; }
+        if (!lines.length) { return; }
+        block.classList.add("hide-boring");
 
         var buttons = document.createElement('div');
         buttons.className = 'buttons';
         buttons.innerHTML = "<button class=\"fa fa-expand\" title=\"Show hidden lines\" aria-label=\"Show hidden lines\"></button>";
 
         // add expand button
+        var pre_block = block.parentNode;
         pre_block.insertBefore(buttons, pre_block.firstChild);
 
         pre_block.querySelector('.buttons').addEventListener('click', function (e) {
             if (e.target.classList.contains('fa-expand')) {
-                var lines = pre_block.querySelectorAll('span.hidden');
-
                 e.target.classList.remove('fa-expand');
                 e.target.classList.add('fa-compress');
                 e.target.title = 'Hide lines';
                 e.target.setAttribute('aria-label', e.target.title);
 
-                Array.from(lines).forEach(function (line) {
-                    line.classList.remove('hidden');
-                    line.classList.add('unhidden');
-                });
+                block.classList.remove('hide-boring');
             } else if (e.target.classList.contains('fa-compress')) {
-                var lines = pre_block.querySelectorAll('span.unhidden');
-
                 e.target.classList.remove('fa-compress');
                 e.target.classList.add('fa-expand');
                 e.target.title = 'Show hidden lines';
                 e.target.setAttribute('aria-label', e.target.title);
 
-                Array.from(lines).forEach(function (line) {
-                    line.classList.remove('unhidden');
-                    line.classList.add('hidden');
-                });
+                block.classList.add('hide-boring');
             }
         });
     });
 
-    Array.from(document.querySelectorAll('pre code')).forEach(function (block) {
-        var pre_block = block.parentNode;
-        if (!pre_block.classList.contains('playpen')) {
-            var buttons = pre_block.querySelector(".buttons");
-            if (!buttons) {
-                buttons = document.createElement('div');
-                buttons.className = 'buttons';
-                pre_block.insertBefore(buttons, pre_block.firstChild);
+    if (window.playground_copyable) {
+        Array.from(document.querySelectorAll('pre code')).forEach(function (block) {
+            var pre_block = block.parentNode;
+            if (!pre_block.classList.contains('playground')) {
+                var buttons = pre_block.querySelector(".buttons");
+                if (!buttons) {
+                    buttons = document.createElement('div');
+                    buttons.className = 'buttons';
+                    pre_block.insertBefore(buttons, pre_block.firstChild);
+                }
+
+                var clipButton = document.createElement('button');
+                clipButton.className = 'fa fa-copy clip-button';
+                clipButton.title = 'Copy to clipboard';
+                clipButton.setAttribute('aria-label', clipButton.title);
+                clipButton.innerHTML = '<i class=\"tooltiptext\"></i>';
+
+                buttons.insertBefore(clipButton, buttons.firstChild);
             }
+        });
+    }
 
-            var clipButton = document.createElement('button');
-            clipButton.className = 'fa fa-copy clip-button';
-            clipButton.title = 'Copy to clipboard';
-            clipButton.setAttribute('aria-label', clipButton.title);
-            clipButton.innerHTML = '<i class=\"tooltiptext\"></i>';
-
-            buttons.insertBefore(clipButton, buttons.firstChild);
-        }
-    });
-
-    // Process playpen code blocks
-    Array.from(document.querySelectorAll(".playpen")).forEach(function (pre_block) {
+    // Process playground code blocks
+    Array.from(document.querySelectorAll(".playground")).forEach(function (pre_block) {
         // Add play button
         var buttons = pre_block.querySelector(".buttons");
         if (!buttons) {
@@ -263,19 +238,21 @@ function playpen_text(playpen) {
         runCodeButton.title = 'Run this code';
         runCodeButton.setAttribute('aria-label', runCodeButton.title);
 
-        var copyCodeClipboardButton = document.createElement('button');
-        copyCodeClipboardButton.className = 'fa fa-copy clip-button';
-        copyCodeClipboardButton.innerHTML = '<i class="tooltiptext"></i>';
-        copyCodeClipboardButton.title = 'Copy to clipboard';
-        copyCodeClipboardButton.setAttribute('aria-label', copyCodeClipboardButton.title);
-
         buttons.insertBefore(runCodeButton, buttons.firstChild);
-        buttons.insertBefore(copyCodeClipboardButton, buttons.firstChild);
-
         runCodeButton.addEventListener('click', function (e) {
             run_rust_code(pre_block);
         });
 
+        if (window.playground_copyable) {
+            var copyCodeClipboardButton = document.createElement('button');
+            copyCodeClipboardButton.className = 'fa fa-copy clip-button';
+            copyCodeClipboardButton.innerHTML = '<i class="tooltiptext"></i>';
+            copyCodeClipboardButton.title = 'Copy to clipboard';
+            copyCodeClipboardButton.setAttribute('aria-label', copyCodeClipboardButton.title);
+
+            buttons.insertBefore(copyCodeClipboardButton, buttons.firstChild);
+        }
+
         let code_block = pre_block.querySelector("code");
         if (window.ace && code_block.classList.contains("editable")) {
             var undoChangesButton = document.createElement('button');
@@ -308,7 +285,7 @@ function playpen_text(playpen) {
     function showThemes() {
         themePopup.style.display = 'block';
         themeToggleButton.setAttribute('aria-expanded', true);
-        themePopup.querySelector("button#" + document.body.className).focus();
+        themePopup.querySelector("button#" + get_theme()).focus();
     }
 
     function hideThemes() {
@@ -317,7 +294,17 @@ function playpen_text(playpen) {
         themeToggleButton.focus();
     }
 
-    function set_theme(theme) {
+    function get_theme() {
+        var theme;
+        try { theme = localStorage.getItem('mdbook-theme'); } catch (e) { }
+        if (theme === null || theme === undefined) {
+            return default_theme;
+        } else {
+            return theme;
+        }
+    }
+
+    function set_theme(theme, store = true) {
         let ace_theme;
 
         if (theme == 'coal' || theme == 'navy') {
@@ -330,13 +317,11 @@ function playpen_text(playpen) {
             stylesheets.ayuHighlight.disabled = false;
             stylesheets.tomorrowNight.disabled = true;
             stylesheets.highlight.disabled = true;
-
             ace_theme = "ace/theme/tomorrow_night";
         } else {
             stylesheets.ayuHighlight.disabled = true;
             stylesheets.tomorrowNight.disabled = true;
             stylesheets.highlight.disabled = false;
-
             ace_theme = "ace/theme/dawn";
         }
 
@@ -350,23 +335,20 @@ function playpen_text(playpen) {
             });
         }
 
-        var previousTheme;
-        try { previousTheme = localStorage.getItem('mdbook-theme'); } catch (e) { }
-        if (previousTheme === null || previousTheme === undefined) { previousTheme = 'light'; }
+        var previousTheme = get_theme();
 
-        try { localStorage.setItem('mdbook-theme', theme); } catch (e) { }
+        if (store) {
+            try { localStorage.setItem('mdbook-theme', theme); } catch (e) { }
+        }
 
-        document.body.className = theme;
         html.classList.remove(previousTheme);
         html.classList.add(theme);
     }
 
     // Set theme
-    var theme;
-    try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
-    if (theme === null || theme === undefined) { theme = 'light'; }
+    var theme = get_theme();
 
-    set_theme(theme);
+    set_theme(theme, false);
 
     themeToggleButton.addEventListener('click', function () {
         if (themePopup.style.display === 'block') {
@@ -388,7 +370,7 @@ function playpen_text(playpen) {
         }
     });
 
-    // Should not be needed, but it works around an issue on macOS & iOS: https://github.com/rust-lang-nursery/mdBook/issues/628
+    // Should not be needed, but it works around an issue on macOS & iOS: https://github.com/rust-lang/mdBook/issues/628
     document.addEventListener('click', function(e) {
         if (themePopup.style.display === 'block' && !themeToggleButton.contains(e.target) && !themePopup.contains(e.target)) {
             hideThemes();
@@ -435,6 +417,7 @@ function playpen_text(playpen) {
     var sidebar = document.getElementById("sidebar");
     var sidebarLinks = document.querySelectorAll('#sidebar a');
     var sidebarToggleButton = document.getElementById("sidebar-toggle");
+    var sidebarResizeHandle = document.getElementById("sidebar-resize-handle");
     var firstContact = null;
 
     function showSidebar() {
@@ -448,6 +431,17 @@ function playpen_text(playpen) {
         try { localStorage.setItem('mdbook-sidebar', 'visible'); } catch (e) { }
     }
 
+
+    var sidebarAnchorToggles = document.querySelectorAll('#sidebar a.toggle');
+
+    function toggleSection(ev) {
+        ev.currentTarget.parentElement.classList.toggle('expanded');
+    }
+
+    Array.from(sidebarAnchorToggles).forEach(function (el) {
+        el.addEventListener('click', toggleSection);
+    });
+
     function hideSidebar() {
         html.classList.remove('sidebar-visible')
         html.classList.add('sidebar-hidden');
@@ -462,6 +456,11 @@ function playpen_text(playpen) {
     // Toggle sidebar
     sidebarToggleButton.addEventListener('click', function sidebarToggle() {
         if (html.classList.contains("sidebar-hidden")) {
+            var current_width = parseInt(
+                document.documentElement.style.getPropertyValue('--sidebar-width'), 10);
+            if (current_width < 150) {
+                document.documentElement.style.setProperty('--sidebar-width', '150px');
+            }
             showSidebar();
         } else if (html.classList.contains("sidebar-visible")) {
             hideSidebar();
@@ -474,6 +473,32 @@ function playpen_text(playpen) {
         }
     });
 
+    sidebarResizeHandle.addEventListener('mousedown', initResize, false);
+
+    function initResize(e) {
+        window.addEventListener('mousemove', resize, false);
+        window.addEventListener('mouseup', stopResize, false);
+        html.classList.add('sidebar-resizing');
+    }
+    function resize(e) {
+        var pos = (e.clientX - sidebar.offsetLeft);
+        if (pos < 20) {
+            hideSidebar();
+        } else {
+            if (html.classList.contains("sidebar-hidden")) {
+                showSidebar();
+            }
+            pos = Math.min(pos, window.innerWidth - 100);
+            document.documentElement.style.setProperty('--sidebar-width', pos + 'px');
+        }
+    }
+    //on mouseup remove windows functions mousemove & mouseup
+    function stopResize(e) {
+        html.classList.remove('sidebar-resizing');
+        window.removeEventListener('mousemove', resize, false);
+        window.removeEventListener('mouseup', stopResize, false);
+    }
+
     document.addEventListener('touchstart', function (e) {
         firstContact = {
             x: e.touches[0].clientX,
@@ -500,9 +525,10 @@ function playpen_text(playpen) {
     }, { passive: true });
 
     // Scroll sidebar to current active section
-    var activeSection = sidebar.querySelector(".active");
+    var activeSection = document.getElementById("sidebar").querySelector(".active");
     if (activeSection) {
-        sidebar.scrollTop = activeSection.offsetTop;
+        // https://developer.mozilla.org/en-US/docs/Web/API/Element/scrollIntoView
+        activeSection.scrollIntoView({ block: 'center' });
     }
 })();
 
@@ -543,11 +569,11 @@ function playpen_text(playpen) {
         elem.className = 'fa fa-copy tooltipped';
     }
 
-    var clipboardSnippets = new Clipboard('.clip-button', {
+    var clipboardSnippets = new ClipboardJS('.clip-button', {
         text: function (trigger) {
             hideTooltip(trigger);
-            let playpen = trigger.closest("pre");
-            return playpen_text(playpen);
+            let playground = trigger.closest("pre");
+            return playground_text(playground);
         }
     });
 
@@ -575,26 +601,60 @@ function playpen_text(playpen) {
     });
 })();
 
-(function autoHideMenu() {
+(function controllMenu() {
     var menu = document.getElementById('menu-bar');
 
-    var previousScrollTop = document.scrollingElement.scrollTop;
-
-    document.addEventListener('scroll', function () {
-        if (menu.classList.contains('folded') && document.scrollingElement.scrollTop < previousScrollTop) {
-            menu.classList.remove('folded');
-        } else if (!menu.classList.contains('folded') && document.scrollingElement.scrollTop > previousScrollTop) {
-            menu.classList.add('folded');
-        }
-
-        if (!menu.classList.contains('bordered') && document.scrollingElement.scrollTop > 0) {
-            menu.classList.add('bordered');
-        }
-
-        if (menu.classList.contains('bordered') && document.scrollingElement.scrollTop === 0) {
-            menu.classList.remove('bordered');
-        }
-
-        previousScrollTop = document.scrollingElement.scrollTop;
-    }, { passive: true });
+    (function controllPosition() {
+        var scrollTop = document.scrollingElement.scrollTop;
+        var prevScrollTop = scrollTop;
+        var minMenuY = -menu.clientHeight - 50;
+        // When the script loads, the page can be at any scroll (e.g. if you reforesh it).
+        menu.style.top = scrollTop + 'px';
+        // Same as parseInt(menu.style.top.slice(0, -2), but faster
+        var topCache = menu.style.top.slice(0, -2);
+        menu.classList.remove('sticky');
+        var stickyCache = false; // Same as menu.classList.contains('sticky'), but faster
+        document.addEventListener('scroll', function () {
+            scrollTop = Math.max(document.scrollingElement.scrollTop, 0);
+            // `null` means that it doesn't need to be updated
+            var nextSticky = null;
+            var nextTop = null;
+            var scrollDown = scrollTop > prevScrollTop;
+            var menuPosAbsoluteY = topCache - scrollTop;
+            if (scrollDown) {
+                nextSticky = false;
+                if (menuPosAbsoluteY > 0) {
+                    nextTop = prevScrollTop;
+                }
+            } else {
+                if (menuPosAbsoluteY > 0) {
+                    nextSticky = true;
+                } else if (menuPosAbsoluteY < minMenuY) {
+                    nextTop = prevScrollTop + minMenuY;
+                }
+            }
+            if (nextSticky === true && stickyCache === false) {
+                menu.classList.add('sticky');
+                stickyCache = true;
+            } else if (nextSticky === false && stickyCache === true) {
+                menu.classList.remove('sticky');
+                stickyCache = false;
+            }
+            if (nextTop !== null) {
+                menu.style.top = nextTop + 'px';
+                topCache = nextTop;
+            }
+            prevScrollTop = scrollTop;
+        }, { passive: true });
+    })();
+    (function controllBorder() {
+        menu.classList.remove('bordered');
+        document.addEventListener('scroll', function () {
+            if (menu.offsetTop === 0) {
+                menu.classList.remove('bordered');
+            } else {
+                menu.classList.add('bordered');
+            }
+        }, { passive: true });
+    })();
 })();

src/theme/css/chrome.css

@@ -8,7 +8,9 @@
 ::-webkit-scrollbar-thumb {
     background: var(--scrollbar);
 }
-
+html {
+    scrollbar-color: var(--scrollbar) var(--bg);
+}
 #searchresults a,
 .content a:link,
 a:visited,
@@ -18,14 +20,13 @@ a > .hljs {
 
 /* Menu Bar */
 
-#menu-bar {
-    position: -webkit-sticky;
-    position: sticky;
-    top: 0;
+#menu-bar,
+#menu-bar-hover-placeholder {
     z-index: 101;
     margin: auto calc(0px - var(--page-padding));
 }
-#menu-bar > #menu-bar-sticky-container {
+#menu-bar {
+    position: relative;
     display: flex;
     flex-wrap: wrap;
     background-color: var(--bg);
@@ -33,17 +34,28 @@ a > .hljs {
     border-bottom-width: 1px;
     border-bottom-style: solid;
 }
-.js #menu-bar > #menu-bar-sticky-container {
-    transition: transform 0.3s;
+#menu-bar.sticky,
+.js #menu-bar-hover-placeholder:hover + #menu-bar,
+.js #menu-bar:hover,
+.js.sidebar-visible #menu-bar {
+    position: -webkit-sticky;
+    position: sticky;
+    top: 0 !important;
 }
-#menu-bar.bordered > #menu-bar-sticky-container  {
+#menu-bar-hover-placeholder {
+    position: sticky;
+    position: -webkit-sticky;
+    top: 0;
+    height: var(--menu-bar-height);
+}
+#menu-bar.bordered {
     border-bottom-color: var(--table-border-color);
 }
 #menu-bar i, #menu-bar .icon-button {
     position: relative;
     padding: 0 8px;
     z-index: 10;
-    line-height: 50px;
+    line-height: var(--menu-bar-height);
     cursor: pointer;
     transition: color 0.5s;
 }
@@ -63,27 +75,26 @@ a > .hljs {
     margin: 0;
 }
 
-#print-button {
+.right-buttons {
     margin: 0 15px;
 }
-
-html:not(.sidebar-visible) #menu-bar:not(:hover).folded > #menu-bar-sticky-container {
-    transform: translateY(-60px);
+.right-buttons a {
+    text-decoration: none;
 }
 
 .left-buttons {
     display: flex;
     margin: 0 5px;
 }
-.no-js .left-buttons { 
+.no-js .left-buttons {
     display: none;
 }
 
 .menu-title {
     display: inline-block;
     font-weight: 200;
-    font-size: 20px;
-    line-height: 50px;
+    font-size: 2rem;
+    line-height: var(--menu-bar-height);
     text-align: center;
     margin: 0;
     flex: 1;
@@ -121,7 +132,7 @@ html:not(.sidebar-visible) #menu-bar:not(:hover).folded > #menu-bar-sticky-conta
     text-decoration: none;
 
     position: fixed;
-    top: 50px; /* Height of menu-bar */
+    top: 0;
     bottom: 0;
     margin: 0;
     max-width: 150px;
@@ -132,17 +143,21 @@ html:not(.sidebar-visible) #menu-bar:not(:hover).folded > #menu-bar-sticky-conta
     align-content: center;
     flex-direction: column;
 
-    transition: color 0.5s;
+    transition: color 0.5s, background-color 0.5s;
 }
 
-.nav-chapters:hover { text-decoration: none; }
+.nav-chapters:hover {
+    text-decoration: none;
+    background-color: var(--theme-hover);
+    transition: background-color 0.15s, color 0.15s;
+}
 
 .nav-wrapper {
     margin-top: 50px;
     display: none;
 }
 
-.mobile-nav-chapters { 
+.mobile-nav-chapters {
     font-size: 2.5em;
     text-align: center;
     text-decoration: none;
@@ -173,11 +188,14 @@ html:not(.sidebar-visible) #menu-bar:not(:hover).folded > #menu-bar-sticky-conta
 /* Inline code */
 
 :not(pre) > .hljs {
-    display: inline-block;
-    vertical-align: middle;
+    display: inline;
     padding: 0.1em 0.3em;
     border-radius: 3px;
+}
+
+:not(pre):not(a) > .hljs {
     color: var(--inline-code-color);
+    overflow-x: initial;
 }
 
 a:hover > .hljs {
@@ -298,8 +316,6 @@ ul#searchresults span.teaser em {
     top: 0;
     bottom: 0;
     width: var(--sidebar-width);
-    overflow-y: auto;
-    padding: 10px 10px;
     font-size: 0.875em;
     box-sizing: border-box;
     -webkit-overflow-scrolling: touch;
@@ -307,12 +323,39 @@ ul#searchresults span.teaser em {
     background-color: var(--sidebar-bg);
     color: var(--sidebar-fg);
 }
-.js .sidebar {
+.sidebar-resizing {
+    -moz-user-select: none;
+    -webkit-user-select: none;
+    -ms-user-select: none;
+    user-select: none;
+}
+.js:not(.sidebar-resizing) .sidebar {
     transition: transform 0.3s; /* Animation: slide away */
 }
 .sidebar code {
     line-height: 2em;
 }
+.sidebar .sidebar-scrollbox {
+    overflow-y: auto;
+    position: absolute;
+    top: 0;
+    bottom: 0;
+    left: 0;
+    right: 0;
+    padding: 10px 10px;
+}
+.sidebar .sidebar-resize-handle {
+    position: absolute;
+    cursor: col-resize;
+    width: 0;
+    right: 0;
+    top: 0;
+    bottom: 0;
+}
+.js .sidebar .sidebar-resize-handle {
+    cursor: col-resize;
+    width: 5px;
+}
 .sidebar-hidden .sidebar {
     transform: translateX(calc(0px - var(--sidebar-width)));
 }
@@ -338,22 +381,57 @@ ul#searchresults span.teaser em {
     padding-left: 0;
     line-height: 2.2em;
 }
+
+.chapter ol {
+    width: 100%;
+}
+
 .chapter li {
+    display: flex;
     color: var(--sidebar-non-existant);
 }
 .chapter li a {
-    color: var(--sidebar-fg);
     display: block;
     padding: 0;
     text-decoration: none;
+    color: var(--sidebar-fg);
 }
-.chapter li a:hover { text-decoration: none }
-.chapter li .active,
-a:hover {
-    /* Animate color change */
+
+.chapter li a:hover {
     color: var(--sidebar-active);
 }
 
+.chapter li a.active {
+    color: var(--sidebar-active);
+}
+
+.chapter li > a.toggle {
+    cursor: pointer;
+    display: block;
+    margin-left: auto;
+    padding: 0 10px;
+    user-select: none;
+    opacity: 0.68;
+}
+
+.chapter li > a.toggle div {
+    transition: transform 0.5s;
+}
+
+/* collapse the section */
+.chapter li:not(.expanded) + li > ol {
+    display: none;
+}
+
+.chapter li.chapter-item {
+    line-height: 1.5em;
+    margin-top: 0.6em;
+}
+
+.chapter li.expanded > a.toggle div {
+    transform: rotate(90deg);
+}
+
 .spacer {
     width: 100%;
     height: 3px;
@@ -363,7 +441,7 @@ a:hover {
     background-color: var(--sidebar-spacer);
 }
 
-@media (-moz-touch-enabled: 1), (pointer: coarse) { 
+@media (-moz-touch-enabled: 1), (pointer: coarse) {
     .chapter li a { padding: 5px 0; }
     .spacer { margin: 10px 0; }
 }
@@ -379,7 +457,7 @@ a:hover {
 .theme-popup {
     position: absolute;
     left: 10px;
-    top: 50px;
+    top: var(--menu-bar-height);
     z-index: 1000;
     border-radius: 4px;
     font-size: 0.7em;

src/theme/css/general.css

@@ -2,6 +2,11 @@
 
 @import 'variables.css';
 
+:root {
+    /* Browser default font-size is 16px, this way 1 rem = 10px */
+    font-size: 62.5%;
+}
+
 html {
     font-family: "Open Sans", sans-serif;
     color: var(--fg);
@@ -11,47 +16,61 @@ html {
 
 body {
     margin: 0;
-    font-size: 1rem;
+    font-size: 1.6rem;
     overflow-x: hidden;
 }
 
 code {
-    font-family: "Source Code Pro", Consolas, "Ubuntu Mono", Menlo, "DejaVu Sans Mono", monospace, monospace;
+    font-family: "Source Code Pro", Consolas, "Ubuntu Mono", Menlo, "DejaVu Sans Mono", monospace, monospace !important;
     font-size: 0.875em; /* please adjust the ace font size accordingly in editor.js */
 }
 
+/* Don't change font size in headers. */
+h1 code, h2 code, h3 code, h4 code, h5 code, h6 code {
+    font-size: unset;
+}
+
 .left { float: left; }
 .right { float: right; }
-.hidden { display: none; }
-.play-button.hidden { display: none; }
+.boring { opacity: 0.6; }
+.hide-boring .boring { display: none; }
+.hidden { display: none !important; }
 
 h2, h3 { margin-top: 2.5em; }
 h4, h5 { margin-top: 2em; }
 
 .header + .header h3,
 .header + .header h4,
-.header + .header h5 { 
+.header + .header h5 {
     margin-top: 1em;
 }
 
-a.header:target h1:before,
-a.header:target h2:before,
-a.header:target h3:before,
-a.header:target h4:before {
+h1 a.header:target::before,
+h2 a.header:target::before,
+h3 a.header:target::before,
+h4 a.header:target::before {
     display: inline-block;
     content: "»";
     margin-left: -30px;
     width: 30px;
 }
 
+h1 a.header:target,
+h2 a.header:target,
+h3 a.header:target,
+h4 a.header:target {
+    scroll-margin-top: calc(var(--menu-bar-height) + 0.5em);
+}
+
 .page {
     outline: 0;
     padding: 0 var(--page-padding);
+    margin-top: calc(0px - var(--menu-bar-height)); /* Compensate for the #menu-bar-hover-placeholder */
 }
 .page-wrapper {
     box-sizing: border-box;
 }
-.js .page-wrapper {
+.js:not(.sidebar-resizing) .page-wrapper {
     transition: margin-left 0.3s ease, transform 0.3s ease; /* Animation: slide away */
 }
 
@@ -65,6 +84,9 @@ a.header:target h4:before {
     margin-right: auto;
     max-width: var(--content-max-width);
 }
+.content p { line-height: 1.45em; }
+.content ol { line-height: 1.45em; }
+.content ul { line-height: 1.45em; }
 .content a { text-decoration: none; }
 .content a:hover { text-decoration: underline; }
 .content img { max-width: 100%; }
@@ -92,6 +114,9 @@ table thead td {
     font-weight: 700;
     border: none;
 }
+table thead th {
+    padding: 3px 20px;
+}
 table thead tr {
     border: 1px var(--table-header-bg) solid;
 }
@@ -141,4 +166,9 @@ blockquote {
 .tooltipped .tooltiptext {
     visibility: visible;
 }
-  
+
+.chapter li.part-title {
+    color: var(--sidebar-fg);
+    margin: 5px 0px;
+    font-weight: bold;
+}

src/theme/css/variables.css

@@ -5,6 +5,7 @@
     --sidebar-width: 300px;
     --page-padding: 15px;
     --content-max-width: 750px;
+    --menu-bar-height: 50px;
 }
 
 /* Themes */
@@ -208,3 +209,45 @@
     --searchresults-li-bg: #dec2a2;
     --search-mark-bg: #e69f67;
 }
+
+@media (prefers-color-scheme: dark) {
+    .light.no-js {
+        --bg: hsl(200, 7%, 8%);
+        --fg: #98a3ad;
+
+        --sidebar-bg: #292c2f;
+        --sidebar-fg: #a1adb8;
+        --sidebar-non-existant: #505254;
+        --sidebar-active: #3473ad;
+        --sidebar-spacer: #393939;
+
+        --scrollbar: var(--sidebar-fg);
+
+        --icons: #43484d;
+        --icons-hover: #b3c0cc;
+
+        --links: #2b79a2;
+
+        --inline-code-color: #c5c8c6;;
+
+        --theme-popup-bg: #141617;
+        --theme-popup-border: #43484d;
+        --theme-hover: #1f2124;
+
+        --quote-bg: hsl(234, 21%, 18%);
+        --quote-border: hsl(234, 21%, 23%);
+
+        --table-border-color: hsl(200, 7%, 13%);
+        --table-header-bg: hsl(200, 7%, 28%);
+        --table-alternate-bg: hsl(200, 7%, 11%);
+
+        --searchbar-border-color: #aaa;
+        --searchbar-bg: #b7b7b7;
+        --searchbar-fg: #000;
+        --searchbar-shadow-color: #aaa;
+        --searchresults-header-fg: #666;
+        --searchresults-border-color: #98a3ad;
+        --searchresults-li-bg: #2b2b2f;
+        --search-mark-bg: #355c7d;
+    }
+}

src/theme/favicon.svg

@@ -0,0 +1,22 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 199.7 184.2">
+  <style>
+    @media (prefers-color-scheme: dark) {
+      svg { fill: white; }
+    }
+  </style>
+<path d="M189.5,36.8c0.2,2.8,0,5.1-0.6,6.8L153,162c-0.6,2.1-2,3.7-4.2,5c-2.2,1.2-4.4,1.9-6.7,1.9H31.4c-9.6,0-15.3-2.8-17.3-8.4
+  c-0.8-2.2-0.8-3.9,0.1-5.2c0.9-1.2,2.4-1.8,4.6-1.8H123c7.4,0,12.6-1.4,15.4-4.1s5.7-8.9,8.6-18.4l32.9-108.6
+  c1.8-5.9,1-11.1-2.2-15.6S169.9,0,164,0H72.7c-1,0-3.1,0.4-6.1,1.1l0.1-0.4C64.5,0.2,62.6,0,61,0.1s-3,0.5-4.3,1.4
+  c-1.3,0.9-2.4,1.8-3.2,2.8S52,6.5,51.2,8.1c-0.8,1.6-1.4,3-1.9,4.3s-1.1,2.7-1.8,4.2c-0.7,1.5-1.3,2.7-2,3.7c-0.5,0.6-1.2,1.5-2,2.5
+  s-1.6,2-2.2,2.8s-0.9,1.5-1.1,2.2c-0.2,0.7-0.1,1.8,0.2,3.2c0.3,1.4,0.4,2.4,0.4,3.1c-0.3,3-1.4,6.9-3.3,11.6
+  c-1.9,4.7-3.6,8.1-5.1,10.1c-0.3,0.4-1.2,1.3-2.6,2.7c-1.4,1.4-2.3,2.6-2.6,3.7c-0.3,0.4-0.3,1.5-0.1,3.4c0.3,1.8,0.4,3.1,0.3,3.8
+  c-0.3,2.7-1.3,6.3-3,10.8c-1.7,4.5-3.4,8.2-5,11c-0.2,0.5-0.9,1.4-2,2.8c-1.1,1.4-1.8,2.5-2,3.4c-0.2,0.6-0.1,1.8,0.1,3.4
+  c0.2,1.6,0.2,2.8-0.1,3.6c-0.6,3-1.8,6.7-3.6,11c-1.8,4.3-3.6,7.9-5.4,11c-0.5,0.8-1.1,1.7-2,2.8c-0.8,1.1-1.5,2-2,2.8
+  s-0.8,1.6-1,2.5c-0.1,0.5,0,1.3,0.4,2.3c0.3,1.1,0.4,1.9,0.4,2.6c-0.1,1.1-0.2,2.6-0.5,4.4c-0.2,1.8-0.4,2.9-0.4,3.2
+  c-1.8,4.8-1.7,9.9,0.2,15.2c2.2,6.2,6.2,11.5,11.9,15.8c5.7,4.3,11.7,6.4,17.8,6.4h110.7c5.2,0,10.1-1.7,14.7-5.2s7.7-7.8,9.2-12.9
+  l33-108.6c1.8-5.8,1-10.9-2.2-15.5C194.9,39.7,192.6,38,189.5,36.8z M59.6,122.8L73.8,80c0,0,7,0,10.8,0s28.8-1.7,25.4,17.5
+  c-3.4,19.2-18.8,25.2-36.8,25.4S59.6,122.8,59.6,122.8z M78.6,116.8c4.7-0.1,18.9-2.9,22.1-17.1S89.2,86.3,89.2,86.3l-8.9,0
+  l-10.2,30.5C70.2,116.9,74,116.9,78.6,116.8z M75.3,68.7L89,26.2h9.8l0.8,34l23.6-34h9.9l-13.6,42.5h-7.1l12.5-35.4l-24.5,35.4h-6.8
+  l-0.8-35L82,68.7H75.3z"/>
+</svg>
+<!-- Original image Copyright Dave Gandy — CC BY 4.0 License -->

src/theme/fonts/OPEN-SANS-LICENSE.txt

@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
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+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
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+   limitations under the License.

src/theme/fonts/SOURCE-CODE-PRO-LICENSE.txt

@@ -0,0 +1,93 @@
+Copyright 2010, 2012 Adobe Systems Incorporated (http://www.adobe.com/), with Reserved Font Name 'Source'. All Rights Reserved. Source is a trademark of Adobe Systems Incorporated in the United States and/or other countries.
+
+This Font Software is licensed under the SIL Open Font License, Version 1.1.
+This license is copied below, and is also available with a FAQ at:
+http://scripts.sil.org/OFL
+
+
+-----------------------------------------------------------
+SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
+-----------------------------------------------------------
+
+PREAMBLE
+The goals of the Open Font License (OFL) are to stimulate worldwide
+development of collaborative font projects, to support the font creation
+efforts of academic and linguistic communities, and to provide a free and
+open framework in which fonts may be shared and improved in partnership
+with others.
+
+The OFL allows the licensed fonts to be used, studied, modified and
+redistributed freely as long as they are not sold by themselves. The
+fonts, including any derivative works, can be bundled, embedded, 
+redistributed and/or sold with any software provided that any reserved
+names are not used by derivative works. The fonts and derivatives,
+however, cannot be released under any other type of license. The
+requirement for fonts to remain under this license does not apply
+to any document created using the fonts or their derivatives.
+
+DEFINITIONS
+"Font Software" refers to the set of files released by the Copyright
+Holder(s) under this license and clearly marked as such. This may
+include source files, build scripts and documentation.
+
+"Reserved Font Name" refers to any names specified as such after the
+copyright statement(s).
+
+"Original Version" refers to the collection of Font Software components as
+distributed by the Copyright Holder(s).
+
+"Modified Version" refers to any derivative made by adding to, deleting,
+or substituting -- in part or in whole -- any of the components of the
+Original Version, by changing formats or by porting the Font Software to a
+new environment.
+
+"Author" refers to any designer, engineer, programmer, technical
+writer or other person who contributed to the Font Software.
+
+PERMISSION & CONDITIONS
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of the Font Software, to use, study, copy, merge, embed, modify,
+redistribute, and sell modified and unmodified copies of the Font
+Software, subject to the following conditions:
+
+1) Neither the Font Software nor any of its individual components,
+in Original or Modified Versions, may be sold by itself.
+
+2) Original or Modified Versions of the Font Software may be bundled,
+redistributed and/or sold with any software, provided that each copy
+contains the above copyright notice and this license. These can be
+included either as stand-alone text files, human-readable headers or
+in the appropriate machine-readable metadata fields within text or
+binary files as long as those fields can be easily viewed by the user.
+
+3) No Modified Version of the Font Software may use the Reserved Font
+Name(s) unless explicit written permission is granted by the corresponding
+Copyright Holder. This restriction only applies to the primary font name as
+presented to the users.
+
+4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font
+Software shall not be used to promote, endorse or advertise any
+Modified Version, except to acknowledge the contribution(s) of the
+Copyright Holder(s) and the Author(s) or with their explicit written
+permission.
+
+5) The Font Software, modified or unmodified, in part or in whole,
+must be distributed entirely under this license, and must not be
+distributed under any other license. The requirement for fonts to
+remain under this license does not apply to any document created
+using the Font Software.
+
+TERMINATION
+This license becomes null and void if any of the above conditions are
+not met.
+
+DISCLAIMER
+THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
+OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL THE
+COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
+DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM
+OTHER DEALINGS IN THE FONT SOFTWARE.

src/theme/fonts/fonts.css

@@ -0,0 +1,101 @@
+/* Open Sans is licensed under the Apache License, Version 2.0. See http://www.apache.org/licenses/LICENSE-2.0 */
+/* Source Code Pro is under the Open Font License. See https://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&id=OFL */
+
+/* open-sans-300 - latin_vietnamese_latin-ext_greek-ext_greek_cyrillic-ext_cyrillic */
+@font-face {
+  font-family: 'Open Sans';
+  font-style: normal;
+  font-weight: 300;
+  src: local('Open Sans Light'), local('OpenSans-Light'),
+       url('open-sans-v17-all-charsets-300.woff2') format('woff2');
+}
+
+/* open-sans-300italic - latin_vietnamese_latin-ext_greek-ext_greek_cyrillic-ext_cyrillic */
+@font-face {
+  font-family: 'Open Sans';
+  font-style: italic;
+  font-weight: 300;
+  src: local('Open Sans Light Italic'), local('OpenSans-LightItalic'),
+       url('open-sans-v17-all-charsets-300italic.woff2') format('woff2');
+}
+
+/* open-sans-regular - latin_vietnamese_latin-ext_greek-ext_greek_cyrillic-ext_cyrillic */
+@font-face {
+  font-family: 'Open Sans';
+  font-style: normal;
+  font-weight: 400;
+  src: local('Open Sans Regular'), local('OpenSans-Regular'),
+       url('open-sans-v17-all-charsets-regular.woff2') format('woff2');
+}
+
+/* open-sans-italic - latin_vietnamese_latin-ext_greek-ext_greek_cyrillic-ext_cyrillic */
+@font-face {
+  font-family: 'Open Sans';
+  font-style: italic;
+  font-weight: 400;
+  src: local('Open Sans Italic'), local('OpenSans-Italic'),
+       url('open-sans-v17-all-charsets-italic.woff2') format('woff2');
+}
+
+/* open-sans-600 - latin_vietnamese_latin-ext_greek-ext_greek_cyrillic-ext_cyrillic */
+@font-face {
+  font-family: 'Open Sans';
+  font-style: normal;
+  font-weight: 600;
+  src: local('Open Sans SemiBold'), local('OpenSans-SemiBold'),
+       url('open-sans-v17-all-charsets-600.woff2') format('woff2');
+}
+
+/* open-sans-600italic - latin_vietnamese_latin-ext_greek-ext_greek_cyrillic-ext_cyrillic */
+@font-face {
+  font-family: 'Open Sans';
+  font-style: italic;
+  font-weight: 600;
+  src: local('Open Sans SemiBold Italic'), local('OpenSans-SemiBoldItalic'),
+       url('open-sans-v17-all-charsets-600italic.woff2') format('woff2');
+}
+
+/* open-sans-700 - latin_vietnamese_latin-ext_greek-ext_greek_cyrillic-ext_cyrillic */
+@font-face {
+  font-family: 'Open Sans';
+  font-style: normal;
+  font-weight: 700;
+  src: local('Open Sans Bold'), local('OpenSans-Bold'),
+       url('open-sans-v17-all-charsets-700.woff2') format('woff2');
+}
+
+/* open-sans-700italic - latin_vietnamese_latin-ext_greek-ext_greek_cyrillic-ext_cyrillic */
+@font-face {
+  font-family: 'Open Sans';
+  font-style: italic;
+  font-weight: 700;
+  src: local('Open Sans Bold Italic'), local('OpenSans-BoldItalic'),
+       url('open-sans-v17-all-charsets-700italic.woff2') format('woff2');
+}
+
+/* open-sans-800 - latin_vietnamese_latin-ext_greek-ext_greek_cyrillic-ext_cyrillic */
+@font-face {
+  font-family: 'Open Sans';
+  font-style: normal;
+  font-weight: 800;
+  src: local('Open Sans ExtraBold'), local('OpenSans-ExtraBold'),
+       url('open-sans-v17-all-charsets-800.woff2') format('woff2');
+}
+
+/* open-sans-800italic - latin_vietnamese_latin-ext_greek-ext_greek_cyrillic-ext_cyrillic */
+@font-face {
+  font-family: 'Open Sans';
+  font-style: italic;
+  font-weight: 800;
+  src: local('Open Sans ExtraBold Italic'), local('OpenSans-ExtraBoldItalic'),
+       url('open-sans-v17-all-charsets-800italic.woff2') format('woff2');
+}
+
+/* source-code-pro-500 - latin_vietnamese_latin-ext_greek_cyrillic-ext_cyrillic */
+@font-face {
+  font-family: 'Source Code Pro';
+  font-style: normal;
+  font-weight: 500;
+  src: local('Source Code Pro Medium'), local('SourceCodePro-Medium'),
+       url('source-code-pro-v11-all-charsets-500.woff2') format('woff2');
+}

src/theme/fonts/mod.rs

@@ -0,0 +1,61 @@
+pub static CSS: &[u8] = include_bytes!("fonts.css");
+// An array of (file_name, file_contents) pairs
+pub static LICENSES: [(&str, &[u8]); 2] = [
+    (
+        "fonts/OPEN-SANS-LICENSE.txt",
+        include_bytes!("OPEN-SANS-LICENSE.txt"),
+    ),
+    (
+        "fonts/SOURCE-CODE-PRO-LICENSE.txt",
+        include_bytes!("SOURCE-CODE-PRO-LICENSE.txt"),
+    ),
+];
+// An array of (file_name, file_contents) pairs
+pub static OPEN_SANS: [(&str, &[u8]); 10] = [
+    (
+        "fonts/open-sans-v17-all-charsets-300.woff2",
+        include_bytes!("open-sans-v17-all-charsets-300.woff2"),
+    ),
+    (
+        "fonts/open-sans-v17-all-charsets-300italic.woff2",
+        include_bytes!("open-sans-v17-all-charsets-300italic.woff2"),
+    ),
+    (
+        "fonts/open-sans-v17-all-charsets-regular.woff2",
+        include_bytes!("open-sans-v17-all-charsets-regular.woff2"),
+    ),
+    (
+        "fonts/open-sans-v17-all-charsets-italic.woff2",
+        include_bytes!("open-sans-v17-all-charsets-italic.woff2"),
+    ),
+    (
+        "fonts/open-sans-v17-all-charsets-600.woff2",
+        include_bytes!("open-sans-v17-all-charsets-600.woff2"),
+    ),
+    (
+        "fonts/open-sans-v17-all-charsets-600italic.woff2",
+        include_bytes!("open-sans-v17-all-charsets-600italic.woff2"),
+    ),
+    (
+        "fonts/open-sans-v17-all-charsets-700.woff2",
+        include_bytes!("open-sans-v17-all-charsets-700.woff2"),
+    ),
+    (
+        "fonts/open-sans-v17-all-charsets-700italic.woff2",
+        include_bytes!("open-sans-v17-all-charsets-700italic.woff2"),
+    ),
+    (
+        "fonts/open-sans-v17-all-charsets-800.woff2",
+        include_bytes!("open-sans-v17-all-charsets-800.woff2"),
+    ),
+    (
+        "fonts/open-sans-v17-all-charsets-800italic.woff2",
+        include_bytes!("open-sans-v17-all-charsets-800italic.woff2"),
+    ),
+];
+
+// A (file_name, file_contents) pair
+pub static SOURCE_CODE_PRO: (&str, &[u8]) = (
+    "fonts/source-code-pro-v11-all-charsets-500.woff2",
+    include_bytes!("source-code-pro-v11-all-charsets-500.woff2"),
+);

src/theme/head.hbs

@@ -0,0 +1 @@
+{{!-- Put your head HTML text here --}}

src/theme/highlight.css

@@ -67,3 +67,13 @@
 .hljs-strong {
   font-weight: bold;
 }
+
+.hljs-addition {
+  color: #22863a;
+  background-color: #f0fff4;
+}
+
+.hljs-deletion {
+  color: #b31d28;
+  background-color: #ffeef0;
+}

src/theme/index.hbs

@@ -1,15 +1,27 @@
 <!DOCTYPE HTML>
-<html lang="{{ language }}" class="sidebar-visible no-js">
+<html lang="{{ language }}" class="sidebar-visible no-js {{ default_theme }}">
     <head>
         <!-- Book generated using mdBook -->
         <meta charset="UTF-8">
         <title>{{ title }}</title>
+        {{#if is_print }}
+        <meta name="robots" content="noindex" />
+        {{/if}}
+        {{#if base_url}}
+        <base href="{{ base_url }}">
+        {{/if}}
+
+
+        <!-- Custom HTML head -->
+        {{> head}}
+
         <meta content="text/html; charset=utf-8" http-equiv="Content-Type">
         <meta name="description" content="{{ description }}">
         <meta name="viewport" content="width=device-width, initial-scale=1">
         <meta name="theme-color" content="#ffffff" />
 
-        <link rel="shortcut icon" href="{{ path_to_root }}{{ favicon }}">
+        <link rel="icon" href="{{ path_to_root }}favicon.svg">
+        <link rel="shortcut icon" href="{{ path_to_root }}favicon.png">
         <link rel="stylesheet" href="{{ path_to_root }}css/variables.css">
         <link rel="stylesheet" href="{{ path_to_root }}css/general.css">
         <link rel="stylesheet" href="{{ path_to_root }}css/chrome.css">
@@ -17,8 +29,9 @@
 
         <!-- Fonts -->
         <link rel="stylesheet" href="{{ path_to_root }}FontAwesome/css/font-awesome.css">
-        <link href="https://fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,600italic,700italic,800italic,400,300,600,700,800" rel="stylesheet" type="text/css">
-        <link href="https://fonts.googleapis.com/css?family=Source+Code+Pro:500" rel="stylesheet" type="text/css">
+        {{#if copy_fonts}}
+        <link rel="stylesheet" href="{{ path_to_root }}fonts/fonts.css">
+        {{/if}}
 
         <!-- Highlight.js Stylesheets -->
         <link rel="stylesheet" href="{{ path_to_root }}highlight.css">
@@ -35,9 +48,12 @@
         <script async type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
         {{/if}}
     </head>
-    <body class="light">
+    <body>
         <!-- Provide site root to javascript -->
-        <script type="text/javascript">var path_to_root = "{{ path_to_root }}";</script>
+        <script type="text/javascript">
+            var path_to_root = "{{ path_to_root }}";
+            var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "{{ preferred_dark_theme }}" : "{{ default_theme }}";
+        </script>
 
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
         <script type="text/javascript">
@@ -58,10 +74,13 @@
         <!-- Set the theme before any content is loaded, prevents flash -->
         <script type="text/javascript">
             var theme;
-            try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { } 
-            if (theme === null || theme === undefined) { theme = 'light'; }
-            document.body.className = theme;
-            document.querySelector('html').className = theme + ' js';
+            try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
+            if (theme === null || theme === undefined) { theme = default_theme; }
+            var html = document.querySelector('html');
+            html.classList.remove('no-js')
+            html.classList.remove('{{ default_theme }}')
+            html.classList.add(theme);
+            html.classList.add('js');
         </script>
 
         <!-- Hide / unhide sidebar before it is displayed -->
@@ -77,43 +96,50 @@
         </script>
 
         <nav id="sidebar" class="sidebar" aria-label="Table of contents">
-            {{#toc}}{{/toc}}
+            <div class="sidebar-scrollbox">
+                {{#toc}}{{/toc}}
+            </div>
+            <div id="sidebar-resize-handle" class="sidebar-resize-handle"></div>
         </nav>
 
         <div id="page-wrapper" class="page-wrapper">
 
             <div class="page">
                 {{> header}}
-                <div id="menu-bar" class="menu-bar">
-                    <div id="menu-bar-sticky-container">
-                        <div class="left-buttons">
-                            <button id="sidebar-toggle" class="icon-button" type="button" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
-                                <i class="fa fa-bars"></i>
-                            </button>
-                            <button id="theme-toggle" class="icon-button" type="button" title="Change theme" aria-label="Change theme" aria-haspopup="true" aria-expanded="false" aria-controls="theme-list">
-                                <i class="fa fa-paint-brush"></i>
-                            </button>
-                            <ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
-                                <li role="none"><button role="menuitem" class="theme" id="light">Light <span class="default">(default)</span></button></li>
-                                <li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
-                                <li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
-                                <li role="none"><button role="menuitem" class="theme" id="navy">Navy</button></li>
-                                <li role="none"><button role="menuitem" class="theme" id="ayu">Ayu</button></li>
-                            </ul>
-                            {{#if search_enabled}}
-                            <button id="search-toggle" class="icon-button" type="button" title="Search. (Shortkey: s)" aria-label="Toggle Searchbar" aria-expanded="false" aria-keyshortcuts="S" aria-controls="searchbar">
-                                <i class="fa fa-search"></i>
-                            </button>
-                            {{/if}}
-                        </div>
+                <div id="menu-bar-hover-placeholder"></div>
+                <div id="menu-bar" class="menu-bar sticky bordered">
+                    <div class="left-buttons">
+                        <button id="sidebar-toggle" class="icon-button" type="button" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
+                            <i class="fa fa-bars"></i>
+                        </button>
+                        <button id="theme-toggle" class="icon-button" type="button" title="Change theme" aria-label="Change theme" aria-haspopup="true" aria-expanded="false" aria-controls="theme-list">
+                            <i class="fa fa-paint-brush"></i>
+                        </button>
+                        <ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
+                            <li role="none"><button role="menuitem" class="theme" id="light">{{ theme_option "Light" }}</button></li>
+                            <li role="none"><button role="menuitem" class="theme" id="rust">{{ theme_option "Rust" }}</button></li>
+                            <li role="none"><button role="menuitem" class="theme" id="coal">{{ theme_option "Coal" }}</button></li>
+                            <li role="none"><button role="menuitem" class="theme" id="navy">{{ theme_option "Navy" }}</button></li>
+                            <li role="none"><button role="menuitem" class="theme" id="ayu">{{ theme_option "Ayu" }}</button></li>
+                        </ul>
+                        {{#if search_enabled}}
+                        <button id="search-toggle" class="icon-button" type="button" title="Search. (Shortkey: s)" aria-label="Toggle Searchbar" aria-expanded="false" aria-keyshortcuts="S" aria-controls="searchbar">
+                            <i class="fa fa-search"></i>
+                        </button>
+                        {{/if}}
+                    </div>
 
-                        <h1 class="menu-title">{{ book_title }}</h1> 
+                    <h1 class="menu-title">{{ book_title }}</h1>
 
-                        <div class="right-buttons">
-                            <a href="{{ path_to_root }}print.html" title="Print this book" aria-label="Print this book">
-                                <i id="print-button" class="fa fa-print"></i>
-                            </a>
-                        </div>
+                    <div class="right-buttons">
+                        <a href="{{ path_to_root }}print.html" title="Print this book" aria-label="Print this book">
+                            <i id="print-button" class="fa fa-print"></i>
+                        </a>
+                        {{#if git_repository_url}}
+                        <a href="{{git_repository_url}}" title="Git repository" aria-label="Git repository">
+                            <i id="git-repository-button" class="fa {{git_repository_icon}}"></i>
+                        </a>
+                        {{/if}}
                     </div>
                 </div>
 
@@ -165,13 +191,13 @@
 
             <nav class="nav-wide-wrapper" aria-label="Page navigation">
                 {{#previous}}
-                    <a href="{{ path_to_root }}{{link}}" class="nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
+                    <a rel="prev" href="{{ path_to_root }}{{link}}" class="nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
                         <i class="fa fa-angle-left"></i>
                     </a>
                 {{/previous}}
 
                 {{#next}}
-                    <a href="{{ path_to_root }}{{link}}" class="nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
+                    <a rel="next" href="{{ path_to_root }}{{link}}" class="nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
                         <i class="fa fa-angle-right"></i>
                     </a>
                 {{/next}}
@@ -186,7 +212,7 @@
             socket.onmessage = function (event) {
                 if (event.data === "reload") {
                     socket.close();
-                    location.reload(true); // force reload from server (not from cache)
+                    location.reload();
                 }
             };
 
@@ -215,7 +241,19 @@
         </script>
         {{/if}}
 
-        {{#if playpen_js}}
+        {{#if playground_line_numbers}}
+        <script type="text/javascript">
+            window.playground_line_numbers = true;
+        </script>
+        {{/if}}
+
+        {{#if playground_copyable}}
+        <script type="text/javascript">
+            window.playground_copyable = true;
+        </script>
+        {{/if}}
+
+        {{#if playground_js}}
         <script src="{{ path_to_root }}ace.js" type="text/javascript" charset="utf-8"></script>
         <script src="{{ path_to_root }}editor.js" type="text/javascript" charset="utf-8"></script>
         <script src="{{ path_to_root }}mode-rust.js" type="text/javascript" charset="utf-8"></script>

src/theme/mod.rs

@@ -1,6 +1,8 @@
 #![allow(missing_docs)]
 
-pub mod playpen_editor;
+pub mod playground_editor;
+
+pub mod fonts;
 
 #[cfg(feature = "search")]
 pub mod searcher;
@@ -9,33 +11,32 @@ use std::fs::File;
 use std::io::Read;
 use std::path::Path;
 
-use errors::*;
+use crate::errors::*;
 
-pub static INDEX: &'static [u8] = include_bytes!("index.hbs");
-pub static HEADER: &'static [u8] = include_bytes!("header.hbs");
-pub static CHROME_CSS: &'static [u8] = include_bytes!("css/chrome.css");
-pub static GENERAL_CSS: &'static [u8] = include_bytes!("css/general.css");
-pub static PRINT_CSS: &'static [u8] = include_bytes!("css/print.css");
-pub static VARIABLES_CSS: &'static [u8] = include_bytes!("css/variables.css");
-pub static FAVICON: &'static [u8] = include_bytes!("favicon.png");
-pub static JS: &'static [u8] = include_bytes!("book.js");
-pub static HIGHLIGHT_JS: &'static [u8] = include_bytes!("highlight.js");
-pub static TOMORROW_NIGHT_CSS: &'static [u8] = include_bytes!("tomorrow-night.css");
-pub static HIGHLIGHT_CSS: &'static [u8] = include_bytes!("highlight.css");
-pub static AYU_HIGHLIGHT_CSS: &'static [u8] = include_bytes!("ayu-highlight.css");
-pub static CLIPBOARD_JS: &'static [u8] = include_bytes!("clipboard.min.js");
-pub static FONT_AWESOME: &'static [u8] = include_bytes!("FontAwesome/css/font-awesome.min.css");
-pub static FONT_AWESOME_EOT: &'static [u8] =
-    include_bytes!("FontAwesome/fonts/fontawesome-webfont.eot");
-pub static FONT_AWESOME_SVG: &'static [u8] =
-    include_bytes!("FontAwesome/fonts/fontawesome-webfont.svg");
-pub static FONT_AWESOME_TTF: &'static [u8] =
-    include_bytes!("FontAwesome/fonts/fontawesome-webfont.ttf");
-pub static FONT_AWESOME_WOFF: &'static [u8] =
-    include_bytes!("FontAwesome/fonts/fontawesome-webfont.woff");
-pub static FONT_AWESOME_WOFF2: &'static [u8] =
+pub static INDEX: &[u8] = include_bytes!("index.hbs");
+pub static HEAD: &[u8] = include_bytes!("head.hbs");
+pub static REDIRECT: &[u8] = include_bytes!("redirect.hbs");
+pub static HEADER: &[u8] = include_bytes!("header.hbs");
+pub static CHROME_CSS: &[u8] = include_bytes!("css/chrome.css");
+pub static GENERAL_CSS: &[u8] = include_bytes!("css/general.css");
+pub static PRINT_CSS: &[u8] = include_bytes!("css/print.css");
+pub static VARIABLES_CSS: &[u8] = include_bytes!("css/variables.css");
+pub static FAVICON_PNG: &[u8] = include_bytes!("favicon.png");
+pub static FAVICON_SVG: &[u8] = include_bytes!("favicon.svg");
+pub static JS: &[u8] = include_bytes!("book.js");
+pub static HIGHLIGHT_JS: &[u8] = include_bytes!("highlight.js");
+pub static TOMORROW_NIGHT_CSS: &[u8] = include_bytes!("tomorrow-night.css");
+pub static HIGHLIGHT_CSS: &[u8] = include_bytes!("highlight.css");
+pub static AYU_HIGHLIGHT_CSS: &[u8] = include_bytes!("ayu-highlight.css");
+pub static CLIPBOARD_JS: &[u8] = include_bytes!("clipboard.min.js");
+pub static FONT_AWESOME: &[u8] = include_bytes!("FontAwesome/css/font-awesome.min.css");
+pub static FONT_AWESOME_EOT: &[u8] = include_bytes!("FontAwesome/fonts/fontawesome-webfont.eot");
+pub static FONT_AWESOME_SVG: &[u8] = include_bytes!("FontAwesome/fonts/fontawesome-webfont.svg");
+pub static FONT_AWESOME_TTF: &[u8] = include_bytes!("FontAwesome/fonts/fontawesome-webfont.ttf");
+pub static FONT_AWESOME_WOFF: &[u8] = include_bytes!("FontAwesome/fonts/fontawesome-webfont.woff");
+pub static FONT_AWESOME_WOFF2: &[u8] =
     include_bytes!("FontAwesome/fonts/fontawesome-webfont.woff2");
-pub static FONT_AWESOME_OTF: &'static [u8] = include_bytes!("FontAwesome/fonts/FontAwesome.otf");
+pub static FONT_AWESOME_OTF: &[u8] = include_bytes!("FontAwesome/fonts/FontAwesome.otf");
 
 /// The `Theme` struct should be used instead of the static variables because
 /// the `new()` method will look if the user has a theme directory in their
@@ -46,12 +47,15 @@ pub static FONT_AWESOME_OTF: &'static [u8] = include_bytes!("FontAwesome/fonts/F
 #[derive(Debug, PartialEq)]
 pub struct Theme {
     pub index: Vec<u8>,
+    pub head: Vec<u8>,
+    pub redirect: Vec<u8>,
     pub header: Vec<u8>,
     pub chrome_css: Vec<u8>,
     pub general_css: Vec<u8>,
     pub print_css: Vec<u8>,
     pub variables_css: Vec<u8>,
-    pub favicon: Vec<u8>,
+    pub favicon_png: Option<Vec<u8>>,
+    pub favicon_svg: Option<Vec<u8>>,
     pub js: Vec<u8>,
     pub highlight_css: Vec<u8>,
     pub tomorrow_night_css: Vec<u8>,
@@ -76,6 +80,8 @@ impl Theme {
         {
             let files = vec![
                 (theme_dir.join("index.hbs"), &mut theme.index),
+                (theme_dir.join("head.hbs"), &mut theme.head),
+                (theme_dir.join("redirect.hbs"), &mut theme.redirect),
                 (theme_dir.join("header.hbs"), &mut theme.header),
                 (theme_dir.join("book.js"), &mut theme.js),
                 (theme_dir.join("css/chrome.css"), &mut theme.chrome_css),
@@ -85,7 +91,6 @@ impl Theme {
                     theme_dir.join("css/variables.css"),
                     &mut theme.variables_css,
                 ),
-                (theme_dir.join("favicon.png"), &mut theme.favicon),
                 (theme_dir.join("highlight.js"), &mut theme.highlight_js),
                 (theme_dir.join("clipboard.min.js"), &mut theme.clipboard_js),
                 (theme_dir.join("highlight.css"), &mut theme.highlight_css),
@@ -99,13 +104,36 @@ impl Theme {
                 ),
             ];
 
-            for (filename, dest) in files {
+            let load_with_warn = |filename: &Path, dest| {
                 if !filename.exists() {
-                    continue;
+                    // Don't warn if the file doesn't exist.
+                    return false;
                 }
-
-                if let Err(e) = load_file_contents(&filename, dest) {
+                if let Err(e) = load_file_contents(filename, dest) {
                     warn!("Couldn't load custom file, {}: {}", filename.display(), e);
+                    false
+                } else {
+                    true
+                }
+            };
+
+            for (filename, dest) in files {
+                load_with_warn(&filename, dest);
+            }
+
+            // If the user overrides one favicon, but not the other, do not
+            // copy the default for the other.
+            let favicon_png = &mut theme.favicon_png.as_mut().unwrap();
+            let png = load_with_warn(&theme_dir.join("favicon.png"), favicon_png);
+            let favicon_svg = &mut theme.favicon_svg.as_mut().unwrap();
+            let svg = load_with_warn(&theme_dir.join("favicon.svg"), favicon_svg);
+            match (png, svg) {
+                (true, true) | (false, false) => {}
+                (true, false) => {
+                    theme.favicon_svg = None;
+                }
+                (false, true) => {
+                    theme.favicon_png = None;
                 }
             }
         }
@@ -118,12 +146,15 @@ impl Default for Theme {
     fn default() -> Theme {
         Theme {
             index: INDEX.to_owned(),
+            head: HEAD.to_owned(),
+            redirect: REDIRECT.to_owned(),
             header: HEADER.to_owned(),
             chrome_css: CHROME_CSS.to_owned(),
             general_css: GENERAL_CSS.to_owned(),
             print_css: PRINT_CSS.to_owned(),
             variables_css: VARIABLES_CSS.to_owned(),
-            favicon: FAVICON.to_owned(),
+            favicon_png: Some(FAVICON_PNG.to_owned()),
+            favicon_svg: Some(FAVICON_SVG.to_owned()),
             js: JS.to_owned(),
             highlight_css: HIGHLIGHT_CSS.to_owned(),
             tomorrow_night_css: TOMORROW_NIGHT_CSS.to_owned(),
@@ -172,9 +203,13 @@ mod tests {
     fn theme_dir_overrides_defaults() {
         let files = [
             "index.hbs",
+            "head.hbs",
+            "redirect.hbs",
             "header.hbs",
             "favicon.png",
+            "favicon.svg",
             "css/chrome.css",
+            "css/fonts.css",
             "css/general.css",
             "css/print.css",
             "css/variables.css",
@@ -198,12 +233,15 @@ mod tests {
 
         let empty = Theme {
             index: Vec::new(),
+            head: Vec::new(),
+            redirect: Vec::new(),
             header: Vec::new(),
             chrome_css: Vec::new(),
             general_css: Vec::new(),
             print_css: Vec::new(),
             variables_css: Vec::new(),
-            favicon: Vec::new(),
+            favicon_png: Some(Vec::new()),
+            favicon_svg: Some(Vec::new()),
             js: Vec::new(),
             highlight_css: Vec::new(),
             tomorrow_night_css: Vec::new(),
@@ -214,4 +252,19 @@ mod tests {
 
         assert_eq!(got, empty);
     }
+
+    #[test]
+    fn favicon_override() {
+        let temp = TempFileBuilder::new().prefix("mdbook-").tempdir().unwrap();
+        fs::write(temp.path().join("favicon.png"), "1234").unwrap();
+        let got = Theme::new(temp.path());
+        assert_eq!(got.favicon_png.as_ref().unwrap(), b"1234");
+        assert_eq!(got.favicon_svg, None);
+
+        let temp = TempFileBuilder::new().prefix("mdbook-").tempdir().unwrap();
+        fs::write(temp.path().join("favicon.svg"), "4567").unwrap();
+        let got = Theme::new(temp.path());
+        assert_eq!(got.favicon_png, None);
+        assert_eq!(got.favicon_svg.as_ref().unwrap(), b"4567");
+    }
 }

src/theme/playground_editor/editor.js

@@ -6,14 +6,16 @@ window.editors = [];
     }
 
     Array.from(document.querySelectorAll('.editable')).forEach(function(editable) {
+        let display_line_numbers = window.playground_line_numbers || false;
+
         let editor = ace.edit(editable);
             editor.setOptions({
             highlightActiveLine: false,
             showPrintMargin: false,
-            showLineNumbers: false,
-            showGutter: false,
+            showLineNumbers: display_line_numbers,
+            showGutter: display_line_numbers,
             maxLines: Infinity,
-            fontSize: "0.875em" // please adjust the font size of the code in general.styl
+            fontSize: "0.875em" // please adjust the font size of the code in general.css
         });
 
         editor.$blockScrolling = Infinity;