Search with Elasticlunr, updated (#604)

* Add search with elasticlunr.js This commit adds search functionality to mdBook, based on work done by @phaiax. The in-browser search code uses elasticlunr.js to execute the search, using an index generated at book build time by elasticlunr-rs. * Add generator comment Someone on Reddit was wondering how the rust book was generated and said they checked the source. Thought I'd put this here. Might be a good idea to have a little footer "made with mdBook", but this'll do for now. * Remove search/editor file override behavior * Use for loop for book iterator * Improve HTML regex * Fix search CORS in file URIs * Use ammonia to sanitize HTML * Filter html5ever log messages
2018-03-07 07:02:06 -06:00 · 2018-03-07 07:02:06 -06:00 · b2ad669c61
parent bb043ef660
commit b2ad669c61
39 changed files with 3861 additions and 256 deletions
--- a/.gitattributes
+++ b/.gitattributes
@ -2,3 +2,7 @@
 * text=auto eol=lf
 *.rs rust
 *.woff -text
 *.ttf -text
 *.otf -text
 *.png -text
--- a/Cargo.lock
+++ b/Cargo.lock
@ -6,6 +6,19 @@ dependencies = [
 "memchr 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
 name = "ammonia"
 version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "html5ever 0.22.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "lazy_static 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "maplit 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "matches 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
 "tendril 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "url 1.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
 name = "ansi_term"
 version = "0.9.0"
@ -177,6 +190,20 @@ name = "either"
 version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "elasticlunr-rs"
 version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "lazy_static 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "phf 0.7.21 (registry+https://github.com/rust-lang/crates.io-index)",
 "phf_codegen 0.7.21 (registry+https://github.com/rust-lang/crates.io-index)",
 "regex 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde 1.0.27 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde_derive 1.0.27 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde_json 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
 name = "env_logger"
 version = "0.5.3"
@ -288,6 +315,18 @@ dependencies = [
 "syn 0.11.11 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
 name = "html5ever"
 version = "0.22.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "log 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
 "mac 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "markup5ever 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "quote 0.3.15 (registry+https://github.com/rust-lang/crates.io-index)",
 "syn 0.11.11 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
 name = "httparse"
 version = "1.2.4"
@ -428,6 +467,11 @@ name = "mac"
 version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "maplit"
 version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "markup5ever"
 version = "0.3.2"
@ -441,6 +485,21 @@ dependencies = [
 "tendril 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
 name = "markup5ever"
 version = "0.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "phf 0.7.21 (registry+https://github.com/rust-lang/crates.io-index)",
 "phf_codegen 0.7.21 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde 1.0.27 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde_derive 1.0.27 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde_json 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
 "string_cache 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "string_cache_codegen 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "tendril 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
 name = "matches"
 version = "0.1.6"
@ -450,9 +509,11 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 name = "mdbook"
 version = "0.1.4-alpha.0"
 dependencies = [
 "ammonia 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "chrono 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "clap 2.29.4 (registry+https://github.com/rust-lang/crates.io-index)",
 "crossbeam 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "elasticlunr-rs 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "env_logger 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)",
 "error-chain 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "handlebars 0.29.1 (registry+https://github.com/rust-lang/crates.io-index)",
@ -932,6 +993,20 @@ dependencies = [
 "string_cache_shared 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
 name = "string_cache"
 version = "0.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "debug_unreachable 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "lazy_static 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "phf_shared 0.7.21 (registry+https://github.com/rust-lang/crates.io-index)",
 "precomputed-hash 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde 1.0.27 (registry+https://github.com/rust-lang/crates.io-index)",
 "string_cache_codegen 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "string_cache_shared 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
 name = "string_cache_codegen"
 version = "0.4.0"
@ -990,6 +1065,16 @@ dependencies = [
 "utf-8 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
 name = "tendril"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "futf 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
 "mac 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "utf-8 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
 name = "termcolor"
 version = "0.3.4"
@ -1236,6 +1321,7 @@ dependencies = [
 [metadata]
 "checksum aho-corasick 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)" = "d6531d44de723825aa81398a6415283229725a00fa30713812ab9323faa82fc4"
 "checksum ammonia 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "fd4c682378117e4186a492b2252b9537990e1617f44aed9788b9a1149de45477"
 "checksum ansi_term 0.10.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6b3568b48b7cefa6b8ce125f9bb4989e52fbcc29ebea88df04cc7c5f12f70455"
 "checksum ansi_term 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "23ac7c30002a5accbf7e8987d0632fa6de155b7c3d39d0067317a391e00a2ef6"
 "checksum atty 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "8352656fd42c30a0c3c89d26dea01e3b77c0ab2af18230835c15e2e13cd51859"
@ -1261,6 +1347,7 @@ dependencies = [
 "checksum difference 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b3304d19798a8e067e48d8e69b2c37f0b5e9b4e462504ad9e27e9f3fce02bba8"
 "checksum dtoa 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "09c3753c3db574d215cba4ea76018483895d7bff25a31b49ba45db21c48e50ab"
 "checksum either 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "740178ddf48b1a9e878e6d6509a1442a2d42fd2928aae8e7a6f8a36fb01981b3"
 "checksum elasticlunr-rs 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "4e7e7e61115293401a5ec119cf8b6fa28708906569e234af336c8bc0ea0033f4"
 "checksum env_logger 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)" = "f15f0b172cb4f52ed5dbf47f774a387cd2315d1bf7894ab5af9b083ae27efa5a"
 "checksum error 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)" = "a6e606f14042bb87cc02ef6a14db6c90ab92ed6f62d87e69377bc759fd7987cc"
 "checksum error-chain 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ff511d5dc435d703f4971bc399647c9bc38e20cb41452e3b9feb4765419ed3f3"
@ -1273,6 +1360,7 @@ dependencies = [
 "checksum getopts 0.2.17 (registry+https://github.com/rust-lang/crates.io-index)" = "b900c08c1939860ce8b54dc6a89e26e00c04c380fd0e09796799bd7f12861e05"
 "checksum handlebars 0.29.1 (registry+https://github.com/rust-lang/crates.io-index)" = "fb04af2006ea09d985fef82b81e0eb25337e51b691c76403332378a53d521edc"
 "checksum html5ever 0.18.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a49d5001dd1bddf042ea41ed4e0a671d50b1bf187e66b349d7ec613bdce4ad90"
 "checksum html5ever 0.22.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e579ac8647178ab915d400d7d22938bda5cd351c6c62e1c294d56884ccfc75fe"
 "checksum httparse 1.2.4 (registry+https://github.com/rust-lang/crates.io-index)" = "c2f407128745b78abc95c0ffbe4e5d37427fdc0d45470710cfef8c44522a2e37"
 "checksum hyper 0.10.13 (registry+https://github.com/rust-lang/crates.io-index)" = "368cb56b2740ebf4230520e2b90ebb0461e69034d85d1945febd9b3971426db2"
 "checksum idna 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "014b298351066f1512874135335d62a789ffe78a9974f94b43ed5621951eaf7d"
@ -1291,7 +1379,9 @@ dependencies = [
 "checksum log 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)" = "e19e8d5c34a3e0e2223db8e060f9e8264aeeb5c5fc64a4ee9965c062211c024b"
 "checksum log 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "89f010e843f2b1a31dbd316b3b8d443758bc634bed37aabade59c686d644e0a2"
 "checksum mac 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "c41e0c4fef86961ac6d6f8a82609f55f31b05e4fce149ac5710e439df7619ba4"
 "checksum maplit 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "08cbb6b4fef96b6d77bfc40ec491b1690c779e77b05cd9f07f787ed376fd4c43"
 "checksum markup5ever 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "ff834ac7123c6a37826747e5ca09db41fd7a83126792021c2e636ad174bb77d3"
 "checksum markup5ever 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)" = "bfedc97d5a503e96816d10fedcd5b42f760b2e525ce2f7ec71f6a41780548475"
 "checksum matches 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "100aabe6b8ff4e4a7e32c1c13523379802df0772b82466207ac25b013f193376"
 "checksum memchr 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "796fba70e76612589ed2ce7f45282f5af869e0fdd7cc6199fa1aa1f1d591ba9d"
 "checksum mime 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "ba626b8a6de5da682e1caa06bdb42a335aee5a84db8e5046a3e8ab17ba0a3ae0"
@ -1348,6 +1438,7 @@ dependencies = [
 "checksum slab 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "17b4fcaed89ab08ef143da37bc52adbcc04d4a69014f4c1208d6b51f0c47bc23"
 "checksum staticfile 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "31493480e073d52522a94cdf56269dd8eb05f99549effd1826b0271690608878"
 "checksum string_cache 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "413fc7852aeeb5472f1986ef755f561ddf0c789d3d796e65f0b6fe293ecd4ef8"
 "checksum string_cache 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)" = "39cb4173bcbd1319da31faa5468a7e3870683d7a237150b0b0aaafd546f6ad12"
 "checksum string_cache_codegen 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "479cde50c3539481f33906a387f2bd17c8e87cb848c35b6021d41fb81ff9b4d7"
 "checksum string_cache_shared 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b1884d1bc09741d466d9b14e6d37ac89d6909cbcac41dd9ae982d4d063bbedfc"
 "checksum strsim 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "bb4f380125926a99e52bc279241539c018323fab05ad6368b56f93d9369ff550"
@ -1355,6 +1446,7 @@ dependencies = [
 "checksum synom 0.11.3 (registry+https://github.com/rust-lang/crates.io-index)" = "a393066ed9010ebaed60b9eafa373d4b1baac186dd7e008555b0f702b51945b6"
 "checksum tempdir 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "f73eebdb68c14bcb24aef74ea96079830e7fa7b31a6106e42ea7ee887c1e134e"
 "checksum tendril 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "8c1b72f8e2f5b73b65c315b1a70c730f24b9d7a25f39e98de8acbe2bb795caea"
 "checksum tendril 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "9de21546595a0873061940d994bbbc5c35f024ae4fd61ec5c5b159115684f508"
 "checksum termcolor 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = "73e83896da740a4541a6f21606b35f2aa4bada5b65d89dc61114bf9d6ff2dc7e"
 "checksum termion 1.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "689a3bdfaab439fd92bc87df5c4c78417d3cbe537487274e9b0b2dce76e92096"
 "checksum textwrap 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c0b59b6b4b44d867f1370ef1bd91bfb262bf07bf0ae65c202ea2fbc16153b693"
--- a/Cargo.toml
+++ b/Cargo.toml
@ -50,6 +50,10 @@ iron = { version = "0.5", optional = true }
 staticfile = { version = "0.4", optional = true }
 ws = { version = "0.7", optional = true}
 # Search feature
 elasticlunr-rs = { version = "0.2", optional = true }
 ammonia = { version = "1.1", optional = true }
 [build-dependencies]
 error-chain = "0.11"
@ -60,12 +64,13 @@ walkdir = "2.0"
 pulldown-cmark-to-cmark = "1.1.0"
 [features]
-default = ["output", "watch", "serve"]
+default = ["output", "watch", "serve", "search"]
 debug = []
 output = []
 regenerate-css = []
 watch = ["notify", "time", "crossbeam"]
 serve = ["iron", "staticfile", "ws"]
 search = ["elasticlunr-rs", "ammonia"]
 [[bin]]
 doc = false
--- a/book-example/book.toml
+++ b/book-example/book.toml
@ -8,3 +8,12 @@ mathjax-support = true
 [output.html.playpen]
 editable = true
 [output.html.search]
 limit-results = 20
 use-boolean-and = true
 boost-title = 2
 boost-hierarchy = 2
 boost-paragraph = 1
 expand = true
 heading-split-level = 2
--- a/book-example/src/format/config.md
+++ b/book-example/src/format/config.md
@ -16,6 +16,9 @@ create-missing = false
 [output.html]
 additional-css = ["custom.css"]
 [output.html.search]
 limit-results = 15
 ```
 ## Supported configuration options
@ -81,14 +84,48 @@ The following configuration options are available:
  stylesheets that will be loaded after the default ones where you can
  surgically change the style.
 - **additional-js:** If you need to add some behaviour to your book without
-  removing the current behaviour, you can specify a set of javascript files
+  removing the current behaviour, you can specify a set of JavaScript files
  that will be loaded alongside the default one.
- **playpen:** A subtable for configuring various playpen settings.
+- **no-section-label:** mdBook by defaults adds section label in table of
 - **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.
 - **search:** A subtable for configuring the in-browser search
  functionality. mdBook must be compiled with the `search` feature enabled
  (on by default).
-**book.toml**
+Available configuration options for the `[output.html.playpen]` table:
 - **editable:** Allow editing the source code. Defaults to `false`.
 - **copy-js:** Copy JavaScript files for the editor to the output directory.
  Defaults to `true`.
 [Ace]: https://ace.c9.io/
 Available configuration options for the `[output.html.search]` table:
 - **limit-results:** The maximum number of search results. Defaults to `30`.
 - **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`.
 - **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 appears in the hierarchy. The hierarchy contains all titles of the
  parent documents and all parent headings. Defaults to `1`.
 - **boost-paragraph:** Boost factor for the search result score if a search 
  word appears in the text. Defaults to `1`.
 - **expand:** True if search should match longer results e.g. search `micro` 
  should match `microwave`. Defaults to `true`.
 - **heading-split-level:** Search results will link to a section of the document
  which contains the result. Documents are split into sections by headings
  this level or less.
  Defaults to `3`. (`### This is a level 3 heading`)
 - **copy-js:** Copy JavaScript files for the search implementation to the
  output directory. Defaults to `true`.
 This shows all available options in the **book.toml**:
 ```toml
 [book]
 title = "Example book"
@ -105,6 +142,18 @@ additional-js = ["custom.js"]
 [output.html.playpen]
 editor = "./path/to/editor"
 editable = false
 [output.html.search]
 enable = true
 searcher = "./path/to/searcher"
 limit-results = 30
 teaser-word-count = 30
 use-boolean-and = true
 boost-title = 2
 boost-hierarchy = 1
 boost-paragraph = 1
 expand = true
 heading-split-level = 3
 ```
@ -145,4 +194,4 @@ override the book's title without needing to touch your `book.toml`.
 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.
+`book.toml` before building.
--- a/book-example/src/misc/contributors.md
+++ b/book-example/src/misc/contributors.md
@ -14,3 +14,5 @@ If you have contributed to mdBook and I forgot to add you, don't hesitate to add
 - [Michael-F-Bryan](https://github.com/Michael-F-Bryan)
 - [Chris Spiegel](https://github.com/cspiegel)
 - [projektir](https://github.com/projektir)
 - [Phaiax](https://github.com/Phaiax)
 - [Matt Ickstadt](https://github.com/mattico)
--- a/ci/script.sh
+++ b/ci/script.sh
@ -3,6 +3,7 @@
 set -ex
 main() {
    cross build --target $TARGET --all --no-default-features
    cross build --target $TARGET --all
    cross build --target $TARGET --all --release
@ -10,6 +11,7 @@ main() {
        return
    fi
    cross test --target $TARGET --no-default-features
    cross test --target $TARGET
    cross test --target $TARGET --release
 }
--- a/src/bin/mdbook.rs
+++ b/src/bin/mdbook.rs
@ -92,6 +92,8 @@ fn init_logger() {
    } else {
        // if no RUST_LOG provided, default to logging at the Info level
        builder.filter(None, LevelFilter::Info);
        // Filter extraneous html5ever not-implemented messages
        builder.filter(Some("html5ever"), LevelFilter::Error);
    }
    builder.init();
--- a/src/book/book.rs
+++ b/src/book/book.rs
@ -152,15 +152,20 @@ pub struct Chapter {
    pub sub_items: Vec<BookItem>,
    /// The chapter's location, relative to the `SUMMARY.md` file.
    pub path: PathBuf,
    /// An ordered list of the names of each chapter above this one, in the hierarchy.
    pub parent_names: Vec<String>,
 }
 impl Chapter {
    /// Create a new chapter with the provided content.
-    pub fn new<P: Into<PathBuf>>(name: &str, content: String, path: P) -> Chapter {
+    pub fn new<P: Into<PathBuf>>(name: &str, content: String, path: P, parent_names: Vec<String>) 
        -> Chapter 
    {
        Chapter {
            name: name.to_string(),
            content: content,
            path: path.into(),
            parent_names: parent_names,
            ..Default::default()
        }
    }
@ -183,21 +188,27 @@ fn load_book_from_disk<P: AsRef<Path>>(summary: &Summary, src_dir: P) -> Result<
    let mut chapters = Vec::new();
    for summary_item in summary_items {
-        let chapter = load_summary_item(summary_item, src_dir)?;
+        let chapter = load_summary_item(summary_item, src_dir, Vec::new())?;
        chapters.push(chapter);
    }
    Ok(Book { sections: chapters })
 }
-fn load_summary_item<P: AsRef<Path>>(item: &SummaryItem, src_dir: P) -> Result<BookItem> {
+fn load_summary_item<P: AsRef<Path>>(item: &SummaryItem, src_dir: P, parent_names: Vec<String>) 
    -> Result<BookItem> 
 {
    match *item {
        SummaryItem::Separator => Ok(BookItem::Separator),
-        SummaryItem::Link(ref link) => load_chapter(link, src_dir).map(|c| BookItem::Chapter(c)),
+        SummaryItem::Link(ref link) => {
            load_chapter(link, src_dir, parent_names).map(|c| BookItem::Chapter(c))
        },
    }
 }
-fn load_chapter<P: AsRef<Path>>(link: &Link, src_dir: P) -> Result<Chapter> {
+fn load_chapter<P: AsRef<Path>>(link: &Link, src_dir: P, parent_names: Vec<String>) 
    -> Result<Chapter> 
 {
    debug!("Loading {} ({})", link.name, link.location.display());
    let src_dir = src_dir.as_ref();
@ -218,12 +229,14 @@ fn load_chapter<P: AsRef<Path>>(link: &Link, src_dir: P) -> Result<Chapter> {
        .strip_prefix(&src_dir)
        .expect("Chapters are always inside a book");
-    let mut ch = Chapter::new(&link.name, content, stripped);
+    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());
    let sub_items = link.nested_items
        .iter()
-        .map(|i| load_summary_item(i, src_dir))
+        .map(|i| load_summary_item(i, src_dir, sub_item_parents.clone()))
        .collect::<Result<Vec<_>>>()?;
    ch.sub_items = sub_items;
@ -324,9 +337,9 @@ And here is some \
    #[test]
    fn load_a_single_chapter_from_disk() {
        let (link, temp_dir) = dummy_link();
-        let should_be = Chapter::new("Chapter 1", DUMMY_SRC.to_string(), "chapter_1.md");
+        let should_be = Chapter::new("Chapter 1", DUMMY_SRC.to_string(), "chapter_1.md", Vec::new());
-        let got = load_chapter(&link, temp_dir.path()).unwrap();
+        let got = load_chapter(&link, temp_dir.path(), Vec::new()).unwrap();
        assert_eq!(got, should_be);
    }
@ -334,7 +347,7 @@ And here is some \
    fn cant_load_a_nonexistent_chapter() {
        let link = Link::new("Chapter 1", "/foo/bar/baz.md");
-        let got = load_chapter(&link, "");
+        let got = load_chapter(&link, "", Vec::new());
        assert!(got.is_err());
    }
@ -347,6 +360,7 @@ And here is some \
            content: String::from("Hello World!"),
            number: Some(SectionNumber(vec![1, 2])),
            path: PathBuf::from("second.md"),
            parent_names: vec![String::from("Chapter 1")],
            sub_items: Vec::new(),
        };
        let should_be = BookItem::Chapter(Chapter {
@ -354,6 +368,7 @@ And here is some \
            content: String::from(DUMMY_SRC),
            number: None,
            path: PathBuf::from("chapter_1.md"),
            parent_names: Vec::new(),
            sub_items: vec![
                BookItem::Chapter(nested.clone()),
                BookItem::Separator,
@ -361,7 +376,7 @@ And here is some \
            ],
        });
-        let got = load_summary_item(&SummaryItem::Link(root), temp.path()).unwrap();
+        let got = load_summary_item(&SummaryItem::Link(root), temp.path(), Vec::new()).unwrap();
        assert_eq!(got, should_be);
    }
@ -417,17 +432,20 @@ And here is some \
                    content: String::from(DUMMY_SRC),
                    number: None,
                    path: PathBuf::from("Chapter_1/index.md"),
                    parent_names: Vec::new(),
                    sub_items: vec![
                        BookItem::Chapter(Chapter::new(
                            "Hello World",
                            String::new(),
                            "Chapter_1/hello.md",
                            Vec::new(),
                        )),
                        BookItem::Separator,
                        BookItem::Chapter(Chapter::new(
                            "Goodbye World",
                            String::new(),
                            "Chapter_1/goodbye.md",
                            Vec::new(),
                        )),
                    ],
                }),
@ -464,17 +482,20 @@ And here is some \
                    content: String::from(DUMMY_SRC),
                    number: None,
                    path: PathBuf::from("Chapter_1/index.md"),
                    parent_names: Vec::new(),
                    sub_items: vec![
                        BookItem::Chapter(Chapter::new(
                            "Hello World",
                            String::new(),
                            "Chapter_1/hello.md",
                            Vec::new(),
                        )),
                        BookItem::Separator,
                        BookItem::Chapter(Chapter::new(
                            "Goodbye World",
                            String::new(),
                            "Chapter_1/goodbye.md",
                            Vec::new(),
                        )),
                    ],
                }),
--- a/src/config.rs
+++ b/src/config.rs
@ -1,13 +1,13 @@
 //! Mdbook's configuration system.
-//! 
+//!
 //! 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 
+//! pre-determined tables (`BookConfig` and `BuildConfig`) as well as support
 //! for arbitrary data which is exposed to plugins and alternate backends.
-//! 
+//!
-//! 
+//!
 //! # Examples
-//! 
+//!
 //! ```rust
 //! # extern crate mdbook;
 //! # use mdbook::errors::*;
@ -15,31 +15,31 @@
 //! use std::path::PathBuf;
 //! use mdbook::Config;
 //! use toml::Value;
-//! 
+//!
 //! # fn run() -> Result<()> {
 //! let src = r#"
 //! [book]
 //! title = "My Book"
 //! authors = ["Michael-F-Bryan"]
-//! 
+//!
 //! [build]
 //! src = "out"
-//! 
+//!
 //! [other-table.foo]
 //! bar = 123
 //! "#;
-//! 
+//!
 //! // load the `Config` from a toml string
 //! let mut cfg = Config::from_str(src)?;
-//! 
+//!
 //! // retrieve a nested value
 //! let bar = cfg.get("other-table.foo.bar").cloned();
 //! assert_eq!(bar, Some(Value::Integer(123)));
-//! 
+//!
 //! // Set the `output.html.theme` directory
 //! assert!(cfg.get("output.html").is_none());
 //! 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"));
@ -410,7 +410,7 @@ pub struct HtmlConfig {
    pub google_analytics: Option<String>,
    /// Additional CSS stylesheets to include in the rendered page's `<head>`.
    pub additional_css: Vec<PathBuf>,
-    /// Additional JS scripts to include at the bottom of the rendered page's 
+    /// Additional JS scripts to include at the bottom of the rendered page's
    /// `<body>`.
    pub additional_js: Vec<PathBuf>,
    /// Playpen settings.
@ -425,29 +425,79 @@ pub struct HtmlConfig {
    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>,
 }
 /// Configuration for tweaking how the the HTML renderer handles the playpen.
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 #[serde(default, rename_all = "kebab-case")]
 pub struct Playpen {
-    /// The path to the editor to use. Defaults to the [Ace Editor].
+    /// Should playpen snippets be editable? Default: `false`.
    /// 
    /// [Ace Editor]: https://ace.c9.io/
    pub editor: PathBuf,
    /// Should playpen snippets be editable? Defaults to `false`.
    pub editable: bool,
    /// Copy JavaScript files for the editor to the output directory?
    /// Default: `true`.
    pub copy_js: bool,
 }
 impl Default for Playpen {
    fn default() -> Playpen {
        Playpen {
            editor: PathBuf::from("ace"),
            editable: false,
            copy_js: true,
        }
    }
 }
 /// Configuration of the search functionality of the HTML renderer.
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 #[serde(default, rename_all = "kebab-case")]
 pub struct Search {
    /// Maximum number of visible results. Default: `30`.
    pub limit_results: u32,
    /// 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`.
    pub use_boolean_and: bool,
    /// Boost factor for the search result score if a search word appears in the header.
    /// Default: `2`.
    pub boost_title: u8,
    /// Boost factor for the search result score if a search word appears in the hierarchy.
    /// The hierarchy contains all titles of the parent documents and all parent headings.
    /// Default: `1`.
    pub boost_hierarchy: u8,
    /// Boost factor for the search result score if a search word appears in the text.
    /// Default: `1`.
    pub boost_paragraph: u8,
    /// True if the searchword `micro` should match `microwave`. Default: `true`.
    pub expand : bool,
    /// Documents are split into smaller parts, seperated by headings. This defines, until which
    /// level of heading documents should be split. Default: `3`. (`### This is a level 3 heading`)
    pub heading_split_level: u8,
    /// Copy JavaScript files for the search functionality to the output directory?
    /// Default: `true`.
    pub copy_js: bool,
 }
 impl Default for Search {
    fn default() -> Search {
        // Please update the documentation of `Search` when changing values!
        Search {
            limit_results: 30,
            teaser_word_count: 30,
            use_boolean_and: false,
            boost_title: 2,
            boost_hierarchy: 1,
            boost_paragraph: 1,
            expand: true,
            heading_split_level: 3,
            copy_js: true,
        }
    }
 }
 /// Allows you to "update" any arbitrary field in a struct by round-tripping via
 /// a `toml::Value`.
 ///
@ -525,7 +575,7 @@ mod tests {
        };
        let playpen_should_be = Playpen {
            editable: true,
-            editor: PathBuf::from("ace"),
+            copy_js: true,
        };
        let html_should_be = HtmlConfig {
            curly_quotes: true,
--- a/src/lib.rs
+++ b/src/lib.rs
@ -52,20 +52,20 @@
 //!
 //! ## Implementing a new Backend
 //!
-//! `mdbook` has a fairly flexible mechanism for creating additional backends 
+//! `mdbook` has a fairly flexible mechanism for creating additional backends
 //! for your book. The general idea is you'll add an extra table in the book's
 //! `book.toml` which specifies an executable to be invoked by `mdbook`. This
-//! executable will then be called during a build, with an in-memory 
+//! executable will then be called during a build, with an in-memory
 //! representation ([`RenderContext`]) of the book being passed to the
-//! subprocess via `stdin`. 
+//! subprocess via `stdin`.
-//! 
+//!
-//! The [`RenderContext`] gives the backend access to the contents of 
+//! The [`RenderContext`] gives the backend access to the contents of
 //! `book.toml` and lets it know which directory all generated artefacts should
 //! be placed in. For a much more in-depth explanation, consult the [relevant
 //! chapter] in the *For Developers* section of the user guide.
-//! 
+//!
-//! To make creating a backend easier, the `mdbook` crate can be imported 
+//! To make creating a backend easier, the `mdbook` crate can be imported
-//! directly, making deserializing the `RenderContext` easy and giving you 
+//! 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/
@ -122,6 +122,7 @@ pub mod errors {
            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 {
--- a/src/renderer/html_handlebars/hbs_renderer.rs
+++ b/src/renderer/html_handlebars/hbs_renderer.rs
@ -1,21 +1,20 @@
 use renderer::html_handlebars::helpers;
 use renderer::{RenderContext, Renderer};
 use book::{Book, BookItem, Chapter};
 use config::{Config, HtmlConfig, Playpen};
 use {theme, utils};
 use theme::{playpen_editor, Theme};
 use errors::*;
-use regex::{Captures, Regex};
+use renderer::{RenderContext, Renderer};
 use renderer::html_handlebars::helpers;
 use theme::{self, Theme, playpen_editor};
 use utils;
 #[allow(unused_imports)] use std::ascii::AsciiExt;
 use std::path::{Path, PathBuf};
 use std::fs::{self, File};
 use std::io::{Read, Write};
 use std::collections::BTreeMap;
 use std::collections::HashMap;
 use std::fs::{self, File};
 use std::io::Read;
 use std::path::{Path, PathBuf};
 use handlebars::Handlebars;
-
+use regex::{Captures, Regex};
 use serde_json;
 #[derive(Default)]
@ -26,23 +25,10 @@ impl HtmlHandlebars {
        HtmlHandlebars
    }
    fn write_file<P: AsRef<Path>>(
        &self,
        build_dir: &Path,
        filename: P,
        content: &[u8],
    ) -> Result<()> {
        let path = build_dir.join(filename);
        utils::fs::create_file(&path)?
            .write_all(content)
            .map_err(|e| e.into())
    }
    fn render_item(
        &self,
-                   item: &BookItem,
+        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
@ -56,6 +42,11 @@ impl HtmlHandlebars {
                let path = ch.path
                    .to_str()
                    .chain_err(|| "Could not convert path to str")?;
                let filepath = Path::new(&ch.path)
                    .with_extension("html");
                let filepathstr = filepath.to_str()
                    .chain_err(|| "Could not convert HTML path to str")?;
                let filepathstr = utils::fs::normalize_path(filepathstr);
                // "print.html" is used for the print page.
                if ch.path == Path::new("print.md") {
@ -83,18 +74,15 @@ impl HtmlHandlebars {
                debug!("Render template");
                let rendered = ctx.handlebars.render("index", &ctx.data)?;
                let filepath = Path::new(&ch.path).with_extension("html");
                let rendered = self.post_process(
                    rendered,
-                    &normalize_path(filepath.to_str().ok_or_else(|| {
+                    &filepathstr,
                        Error::from(format!("Bad file name: {}", filepath.display()))
                    })?),
                    &ctx.html_config.playpen,
                );
                // Write to file
-                debug!("Creating {} ✓", filepath.display());
+                debug!("Creating {} ✓", filepathstr);
-                self.write_file(&ctx.destination, filepath, &rendered.into_bytes())?;
+                utils::fs::write_file(&ctx.destination, &filepath, &rendered.into_bytes())?;
                if ctx.is_index {
                    self.render_index(ch, &ctx.destination)?;
@ -123,7 +111,7 @@ impl HtmlHandlebars {
                         .collect::<Vec<&str>>()
                         .join("\n");
-        self.write_file(destination, "index.html", content.as_bytes())?;
+        utils::fs::write_file(destination, "index.html", content.as_bytes())?;
        debug!(
            "Creating index.html from {} ✓",
@ -153,45 +141,47 @@ impl HtmlHandlebars {
        theme: &Theme,
        html_config: &HtmlConfig,
    ) -> Result<()> {
-        self.write_file(destination, "book.js", &theme.js)?;
+        use utils::fs::write_file;
-        self.write_file(destination, "book.css", &theme.css)?;
+
-        self.write_file(destination, "favicon.png", &theme.favicon)?;
+        write_file(destination, "book.js", &theme.js)?;
-        self.write_file(destination, "highlight.css", &theme.highlight_css)?;
+        write_file(destination, "book.css", &theme.css)?;
-        self.write_file(destination, "tomorrow-night.css", &theme.tomorrow_night_css)?;
+        write_file(destination, "favicon.png", &theme.favicon)?;
-        self.write_file(destination, "ayu-highlight.css", &theme.ayu_highlight_css)?;
+        write_file(destination, "highlight.css", &theme.highlight_css)?;
-        self.write_file(destination, "highlight.js", &theme.highlight_js)?;
+        write_file(destination, "tomorrow-night.css", &theme.tomorrow_night_css)?;
-        self.write_file(destination, "clipboard.min.js", &theme.clipboard_js)?;
+        write_file(destination, "ayu-highlight.css", &theme.ayu_highlight_css)?;
-        self.write_file(
+        write_file(destination, "highlight.js", &theme.highlight_js)?;
        write_file(destination, "clipboard.min.js", &theme.clipboard_js)?;
        write_file(
            destination,
            "_FontAwesome/css/font-awesome.css",
            theme::FONT_AWESOME,
        )?;
-        self.write_file(
+        write_file(
            destination,
            "_FontAwesome/fonts/fontawesome-webfont.eot",
            theme::FONT_AWESOME_EOT,
        )?;
-        self.write_file(
+        write_file(
            destination,
            "_FontAwesome/fonts/fontawesome-webfont.svg",
            theme::FONT_AWESOME_SVG,
        )?;
-        self.write_file(
+        write_file(
            destination,
            "_FontAwesome/fonts/fontawesome-webfont.ttf",
            theme::FONT_AWESOME_TTF,
        )?;
-        self.write_file(
+        write_file(
            destination,
            "_FontAwesome/fonts/fontawesome-webfont.woff",
            theme::FONT_AWESOME_WOFF,
        )?;
-        self.write_file(
+        write_file(
            destination,
            "_FontAwesome/fonts/fontawesome-webfont.woff2",
            theme::FONT_AWESOME_WOFF2,
        )?;
-        self.write_file(
+        write_file(
            destination,
            "_FontAwesome/fonts/FontAwesome.ttf",
            theme::FONT_AWESOME_TTF,
@ -200,16 +190,15 @@ impl HtmlHandlebars {
        let playpen_config = &html_config.playpen;
        // Ace is a very large dependency, so only load it when requested
-        if playpen_config.editable {
+        if playpen_config.editable && playpen_config.copy_js {
            // Load the editor
-            let editor = playpen_editor::PlaypenEditor::new(&playpen_config.editor);
+            write_file(destination, "editor.js", playpen_editor::JS)?;
-            self.write_file(destination, "editor.js", &editor.js)?;
+            write_file(destination, "ace.js", playpen_editor::ACE_JS)?;
-            self.write_file(destination, "ace.js", &editor.ace_js)?;
+            write_file(destination, "mode-rust.js", playpen_editor::MODE_RUST_JS)?;
-            self.write_file(destination, "mode-rust.js", &editor.mode_rust_js)?;
+            write_file(destination, "theme-dawn.js", playpen_editor::THEME_DAWN_JS)?;
-            self.write_file(destination, "theme-dawn.js", &editor.theme_dawn_js)?;
+            write_file(destination,
            self.write_file(destination,
                "theme-tomorrow_night.js",
-                &editor.theme_tomorrow_night_js,
+                playpen_editor::THEME_TOMORROW_NIGHT_JS,
            )?;
        }
@ -307,15 +296,19 @@ impl Renderer for HtmlHandlebars {
        fs::create_dir_all(&destination)
            .chain_err(|| "Unexpected error when constructing destination path")?;
-        for (i, item) in book.iter().enumerate() {
+        let mut is_index = true;
        for item in book.iter() {
            let ctx = RenderItemContext {
                handlebars: &handlebars,
                destination: destination.to_path_buf(),
                data: data.clone(),
-                is_index: i == 0,
+                is_index: is_index,
                html_config: html_config.clone(),
            };
-            self.render_item(item, ctx, &mut print_content)?;
+            self.render_item(item,
                             ctx,
                             &mut print_content)?;
            is_index = false;
        }
        // Print version
@ -326,14 +319,13 @@ impl Renderer for HtmlHandlebars {
        // Render the handlebars template with the data
        debug!("Render template");
        let rendered = handlebars.render("index", &data)?;
        let rendered = self.post_process(rendered,
                                         "print.html",
                                         &html_config.playpen);
-        self.write_file(&destination, "print.html", &rendered.into_bytes())?;
+        utils::fs::write_file(&destination, "print.html", &rendered.into_bytes())?;
        debug!("Creating print.html ✓");
        debug!("Copy static files");
@ -342,6 +334,10 @@ impl Renderer for HtmlHandlebars {
        self.copy_additional_css_and_js(&html_config, &ctx.root, &destination)
            .chain_err(|| "Unable to copy across additional CSS and JS")?;
        // Render search index
        #[cfg(feature = "search")]
        super::search::create_files(&html_config.search.unwrap_or_default(), &destination, &book)?;
        // Copy all remaining files
        utils::fs::copy_files_except_ext(&src_dir, &destination, true, &["md"])?;
@ -405,16 +401,22 @@ fn make_data(root: &Path, book: &Book, config: &Config, html_config: &HtmlConfig
        data.insert("additional_js".to_owned(), json!(js));
    }
-    if html.playpen.editable {
+    if html.playpen.editable && html.playpen.copy_js {
-        data.insert("playpens_editable".to_owned(), json!(true));
+        data.insert("playpen_js".to_owned(), json!(true));
        data.insert("editor_js".to_owned(), json!("editor.js"));
        data.insert("ace_js".to_owned(), json!("ace.js"));
        data.insert("mode_rust_js".to_owned(), json!("mode-rust.js"));
        data.insert("theme_dawn_js".to_owned(), json!("theme-dawn.js"));
        data.insert("theme_tomorrow_night_js".to_owned(),
                    json!("theme-tomorrow_night.js"));
    }
    let search = html_config.search.clone();
    if cfg!(feature = "search") {
        data.insert("search_enabled".to_owned(), json!(true));
        if search.unwrap_or_default().copy_js {
            data.insert("search_js".to_owned(), json!(true));
        }
    } else if search.is_some() {
        warn!("mdBook compiled without search support, ignoring `output.html.search` table");
        warn!("please reinstall with `cargo install mdbook --force --features search`\
            to use the search feature")
    }
    let mut chapters = vec![];
    for item in book.iter() {
@ -469,7 +471,7 @@ fn wrap_header_with_link(level: usize,
                         id_counter: &mut HashMap<String, usize>,
                         filepath: &str)
                         -> String {
-    let raw_id = id_from_content(content);
+    let raw_id = utils::id_from_content(content);
    let id_count = id_counter.entry(raw_id.clone()).or_insert(0);
@ -489,33 +491,6 @@ fn wrap_header_with_link(level: usize,
    )
 }
 /// Generate an id for use with anchors which is derived from a "normalised"
 /// string.
 fn id_from_content(content: &str) -> String {
    let mut content = content.to_string();
    // Skip any tags or html-encoded stuff
    const REPL_SUB: &[&str] = &["<em>",
                                "</em>",
                                "<code>",
                                "</code>",
                                "<strong>",
                                "</strong>",
                                "&lt;",
                                "&gt;",
                                "&amp;",
                                "&#39;",
                                "&quot;"];
    for sub in REPL_SUB {
        content = content.replace(sub, "");
    }
    // Remove spaces and hastags indicating a header
    let trimmed = content.trim().trim_left_matches('#').trim();
    normalize_id(trimmed)
 }
 // anchors to the same page (href="#anchor") do not work because of
 // <base href="../"> pointing to the root folder. This function *fixes*
 // that in a very inelegant way
@ -555,8 +530,7 @@ fn fix_code_blocks(html: &str) -> String {
                before = before,
                classes = classes,
                after = after)
-    })
+    }).into_owned()
         .into_owned()
 }
 fn add_playpen_pre(html: &str, playpen_config: &Playpen) -> String {
@ -591,8 +565,7 @@ fn add_playpen_pre(html: &str, playpen_config: &Playpen) -> String {
            // not language-rust, so no-op
            text.to_owned()
        }
-    })
+    }).into_owned()
         .into_owned()
 }
 fn partition_source(s: &str) -> (String, String) {
@ -624,26 +597,6 @@ struct RenderItemContext<'a> {
    html_config: HtmlConfig,
 }
 pub fn normalize_path(path: &str) -> String {
    use std::path::is_separator;
    path.chars()
        .map(|ch| if is_separator(ch) { '/' } else { ch })
        .collect::<String>()
 }
 pub fn normalize_id(content: &str) -> String {
    content.chars()
           .filter_map(|ch| if ch.is_alphanumeric() || ch == '_' || ch == '-' {
                           Some(ch.to_ascii_lowercase())
                       } else if ch.is_whitespace() {
                           Some('-')
                       } else {
                           None
                       })
           .collect::<String>()
 }
 #[cfg(test)]
 mod tests {
    use super::*;
@ -687,12 +640,4 @@ mod tests {
            assert_eq!(got, should_be);
        }
    }
    #[test]
    fn anchor_generation() {
        assert_eq!(id_from_content("## `--passes`: add more rustdoc passes"),
                   "--passes-add-more-rustdoc-passes");
        assert_eq!(id_from_content("## Method-call expressions"),
                   "method-call-expressions");
    }
 }
--- a/src/renderer/html_handlebars/helpers/mod.rs
+++ b/src/renderer/html_handlebars/helpers/mod.rs
@ -1,2 +1,2 @@
 pub mod navigation;
 pub mod toc;
 pub mod navigation;
--- a/src/renderer/html_handlebars/mod.rs
+++ b/src/renderer/html_handlebars/mod.rs
@ -4,3 +4,6 @@ pub use self::hbs_renderer::HtmlHandlebars;
 mod hbs_renderer;
 mod helpers;
 #[cfg(feature = "search")]
 mod search;
--- a/src/renderer/html_handlebars/search.rs
+++ b/src/renderer/html_handlebars/search.rs
@ -0,0 +1,241 @@
 extern crate ammonia;
 extern crate elasticlunr;
 use std::borrow::Cow;
 use std::collections::{HashMap, HashSet};
 use std::path::Path;
 use pulldown_cmark::*;
 use serde_json;
 use self::elasticlunr::Index;
 use book::{Book, BookItem};
 use config::Search;
 use errors::*;
 use utils;
 use theme::searcher;
 /// Creates all files required for search.
 pub fn create_files(search_config: &Search, destination: &Path, book: &Book) -> Result<()> {
    let mut index = Index::new(&["title", "body", "breadcrumbs"]);
    for item in book.iter() {
        render_item(&mut index, &search_config, item)?;
    }
    let index = write_to_js(index, &search_config)?;
    debug!("Writing search index ✓");
    if search_config.copy_js {
        utils::fs::write_file(destination, "searchindex.js", index.as_bytes())?;
        utils::fs::write_file(destination, "searcher.js", searcher::JS)?;
        utils::fs::write_file(destination, "mark.min.js", searcher::MARK_JS)?;
        utils::fs::write_file(destination, "elasticlunr.min.js", searcher::ELASTICLUNR_JS)?;
        debug!("Copying search files ✓");
    }
    Ok(())
 }
 /// Uses the given arguments to construct a search document, then inserts it to the given index.
 fn add_doc<'a>(
    index: &mut Index,
    anchor_base: &'a str,
    section_id: &Option<String>,
    items: &[&str],
 ) {
    let doc_ref: Cow<'a, str> = if let &Some(ref id) = section_id {
        format!("{}#{}", anchor_base, id).into()
    } else {
        anchor_base.into()
    };
    let doc_ref = utils::collapse_whitespace(doc_ref.trim());
    let items = items.iter().map(|&x| utils::collapse_whitespace(x.trim()));
    index.add_doc(&doc_ref, items);
 }
 /// Renders markdown into flat unformatted text and adds it to the search index.
 fn render_item(
    index: &mut Index,
    search_config: &Search,
    item: &BookItem,
 ) -> Result<()> {
    let chapter = match item {
        &BookItem::Chapter(ref ch) => ch,
        _ => return Ok(()),
    };
    let filepath = Path::new(&chapter.path).with_extension("html");
    let filepath = filepath
        .to_str()
        .chain_err(|| "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 in_header = false;
    let max_section_depth = search_config.heading_split_level as i32;
    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 {
        match event {
            Event::Start(Tag::Header(i)) if i <= max_section_depth => {
                if heading.len() > 0 {
                    // Section finished, the next header is following now
                    // Write the data to the index, and clear it for the next section
                    add_doc(
                        index,
                        &anchor_base,
                        &section_id,
                        &[&heading, &body, &breadcrumbs.join(" » ")],
                    );
                    section_id = None;
                    heading.clear();
                    body.clear();
                    breadcrumbs.pop();
                }
                in_header = true;
            }
            Event::End(Tag::Header(i)) if i <= max_section_depth => {
                in_header = false;
                section_id = Some(utils::id_from_content(&heading));
                breadcrumbs.push(heading.clone());
            }
            Event::Start(Tag::FootnoteDefinition(name)) => {
                let number = footnote_numbers.len() + 1;
                footnote_numbers.entry(name).or_insert(number);
            }
            Event::Start(_) | Event::End(_) | Event::SoftBreak | Event::HardBreak => {
                // Insert spaces where HTML output would usually seperate text
                // to ensure words don't get merged together
                if in_header {
                    heading.push(' ');
                } else {
                    body.push(' ');
                }
            }
            Event::Text(text) => {
                if in_header {
                    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));
            }
        }
    }
    if heading.len() > 0 {
        // Make sure the last section is added to the index
        add_doc(
            index,
            &anchor_base,
            &section_id,
            &[&heading, &body, &breadcrumbs.join(" » ")],
        );
    }
    Ok(())
 }
 /// Exports the index and search options to a JS script which stores the index in `window.search`.
 /// Using a JS script is a workaround for CORS in `file://` URIs. It also removes the need for
 /// downloading/parsing JSON in JS.
 fn write_to_js(index: Index, search_config: &Search) -> Result<String> {
    // These structs mirror the configuration javascript object accepted by
    // http://elasticlunr.com/docs/configuration.js.html
    #[derive(Serialize)]
    struct SearchOptionsField {
        boost: u8,
    }
    #[derive(Serialize)]
    struct SearchOptionsFields {
        title: SearchOptionsField,
        body: SearchOptionsField,
        breadcrumbs: SearchOptionsField,
    }
    #[derive(Serialize)]
    struct SearchOptions {
        bool: String,
        expand: bool,
        limit_results: u32,
        teaser_word_count: u32,
        fields: SearchOptionsFields,
    }
    #[derive(Serialize)]
    struct SearchindexJson {
        /// The searchoptions for elasticlunr.js
        searchoptions: SearchOptions,
        /// The index for elasticlunr.js
        index: elasticlunr::Index,
    }
    let searchoptions = SearchOptions {
        bool: if search_config.use_boolean_and {
            "AND".into()
        } else {
            "OR".into()
        },
        expand: search_config.expand,
        limit_results: search_config.limit_results,
        teaser_word_count: search_config.teaser_word_count,
        fields: SearchOptionsFields {
            title: SearchOptionsField {
                boost: search_config.boost_title,
            },
            body: SearchOptionsField {
                boost: search_config.boost_paragraph,
            },
            breadcrumbs: SearchOptionsField {
                boost: search_config.boost_hierarchy,
            },
        },
    };
    let json_contents = SearchindexJson {
        searchoptions: searchoptions,
        index: index,
    };
    let json_contents = serde_json::to_string(&json_contents)?;
    Ok(format!("window.search = {};", json_contents))
 }
 fn clean_html(html: &str) -> String {
    lazy_static! {
        static ref AMMONIA: ammonia::Builder<'static> = { 
            let mut clean_content = HashSet::new();
            clean_content.insert("script");
            clean_content.insert("style");
            let mut builder = ammonia::Builder::new();
            builder
                .tags(HashSet::new())
                .tag_attributes(HashMap::new())
                .generic_attributes(HashSet::new())
                .link_rel(None)
                .allowed_classes(HashMap::new())
                .clean_content_tags(clean_content);
            builder
        };
    }
    AMMONIA.clean(html).to_string()
 }
--- a/src/theme/book.css
+++ b/src/theme/book.css
@ -36,6 +36,15 @@ 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 {
  display: inline-block;
  content: "»";
  margin-left: -30px;
  width: 30px;
 }
 table {
  margin: 0 auto;
  border-collapse: collapse;
@ -337,6 +346,7 @@ html:not(.sidebar-visible) #menu-bar:not(:hover).folded > #menu-bar-sticky-conta
  color: #333;
  background-color: #fff;
 /* Inline code */
 /* Search */
 }
 .light .content .header:link,
 .light .content .header:visited {
@ -405,6 +415,7 @@ html:not(.sidebar-visible) #menu-bar:not(:hover).folded > #menu-bar-sticky-conta
 .light .mobile-nav-chapters {
  background-color: #fafafa;
 }
 .light #searchresults a,
 .light .content a:link,
 .light a:visited,
 .light a > .hljs {
@ -499,10 +510,34 @@ html:not(.sidebar-visible) #menu-bar:not(:hover).folded > #menu-bar-sticky-conta
 .light ::-webkit-scrollbar-thumb {
  background: #ccc;
 }
 .light #searchbar {
  border: 1px solid #aaa;
  border-radius: 3px;
  background-color: #fafafa;
  color: #000;
 }
 .light #searchbar:focus,
 .light #searchbar.active {
  -webkit-box-shadow: 0 0 3px #aaa;
  box-shadow: 0 0 3px #aaa;
 }
 .light .searchresults-header {
  color: #666;
 }
 .light .searchresults-outer {
  border-bottom: 1px dashed #888;
 }
 .light ul#searchresults li.focus {
  background-color: #e4f2fe;
 }
 .light mark {
  background-color: #a2cff5;
 }
 .coal {
  color: #98a3ad;
  background-color: #141617;
 /* Inline code */
 /* Search */
 }
 .coal .content .header:link,
 .coal .content .header:visited {
@ -571,6 +606,7 @@ html:not(.sidebar-visible) #menu-bar:not(:hover).folded > #menu-bar-sticky-conta
 .coal .mobile-nav-chapters {
  background-color: #292c2f;
 }
 .coal #searchresults a,
 .coal .content a:link,
 .coal a:visited,
 .coal a > .hljs {
@ -665,10 +701,34 @@ html:not(.sidebar-visible) #menu-bar:not(:hover).folded > #menu-bar-sticky-conta
 .coal ::-webkit-scrollbar-thumb {
  background: #a1adb8;
 }
 .coal #searchbar {
  border: 1px solid #aaa;
  border-radius: 3px;
  background-color: #b7b7b7;
  color: #000;
 }
 .coal #searchbar:focus,
 .coal #searchbar.active {
  -webkit-box-shadow: 0 0 3px #aaa;
  box-shadow: 0 0 3px #aaa;
 }
 .coal .searchresults-header {
  color: #666;
 }
 .coal .searchresults-outer {
  border-bottom: 1px dashed #98a3ad;
 }
 .coal ul#searchresults li.focus {
  background-color: #2b2b2f;
 }
 .coal mark {
  background-color: #355c7d;
 }
 .navy {
  color: #bcbdd0;
  background-color: #161923;
 /* Inline code */
 /* Search */
 }
 .navy .content .header:link,
 .navy .content .header:visited {
@ -737,6 +797,7 @@ html:not(.sidebar-visible) #menu-bar:not(:hover).folded > #menu-bar-sticky-conta
 .navy .mobile-nav-chapters {
  background-color: #282d3f;
 }
 .navy #searchresults a,
 .navy .content a:link,
 .navy a:visited,
 .navy a > .hljs {
@ -831,10 +892,34 @@ html:not(.sidebar-visible) #menu-bar:not(:hover).folded > #menu-bar-sticky-conta
 .navy ::-webkit-scrollbar-thumb {
  background: #c8c9db;
 }
 .navy #searchbar {
  border: 1px solid #aaa;
  border-radius: 3px;
  background-color: #aeaec6;
  color: #000;
 }
 .navy #searchbar:focus,
 .navy #searchbar.active {
  -webkit-box-shadow: 0 0 3px #aaa;
  box-shadow: 0 0 3px #aaa;
 }
 .navy .searchresults-header {
  color: #5f5f71;
 }
 .navy .searchresults-outer {
  border-bottom: 1px dashed #5c5c68;
 }
 .navy ul#searchresults li.focus {
  background-color: #242430;
 }
 .navy mark {
  background-color: #a2cff5;
 }
 .rust {
  color: #262625;
  background-color: #e1e1db;
 /* Inline code */
 /* Search */
 }
 .rust .content .header:link,
 .rust .content .header:visited {
@ -903,6 +988,7 @@ html:not(.sidebar-visible) #menu-bar:not(:hover).folded > #menu-bar-sticky-conta
 .rust .mobile-nav-chapters {
  background-color: #3b2e2a;
 }
 .rust #searchresults a,
 .rust .content a:link,
 .rust a:visited,
 .rust a > .hljs {
@ -997,10 +1083,34 @@ html:not(.sidebar-visible) #menu-bar:not(:hover).folded > #menu-bar-sticky-conta
 .rust ::-webkit-scrollbar-thumb {
  background: #c8c9db;
 }
 .rust #searchbar {
  border: 1px solid #aaa;
  border-radius: 3px;
  background-color: #fafafa;
  color: #000;
 }
 .rust #searchbar:focus,
 .rust #searchbar.active {
  -webkit-box-shadow: 0 0 3px #aaa;
  box-shadow: 0 0 3px #aaa;
 }
 .rust .searchresults-header {
  color: #666;
 }
 .rust .searchresults-outer {
  border-bottom: 1px dashed #888;
 }
 .rust ul#searchresults li.focus {
  background-color: #dec2a2;
 }
 .rust mark {
  background-color: #e69f67;
 }
 .ayu {
  color: #c5c5c5;
  background-color: #0f1419;
 /* Inline code */
 /* Search */
 }
 .ayu .content .header:link,
 .ayu .content .header:visited {
@ -1069,6 +1179,7 @@ html:not(.sidebar-visible) #menu-bar:not(:hover).folded > #menu-bar-sticky-conta
 .ayu .mobile-nav-chapters {
  background-color: #14191f;
 }
 .ayu #searchresults a,
 .ayu .content a:link,
 .ayu a:visited,
 .ayu a > .hljs {
@ -1163,6 +1274,29 @@ html:not(.sidebar-visible) #menu-bar:not(:hover).folded > #menu-bar-sticky-conta
 .ayu ::-webkit-scrollbar-thumb {
  background: #c8c9db;
 }
 .ayu #searchbar {
  border: 1px solid #848484;
  border-radius: 3px;
  background-color: #424242;
  color: #fff;
 }
 .ayu #searchbar:focus,
 .ayu #searchbar.active {
  -webkit-box-shadow: 0 0 3px #d4c89f;
  box-shadow: 0 0 3px #d4c89f;
 }
 .ayu .searchresults-header {
  color: #666;
 }
 .ayu .searchresults-outer {
  border-bottom: 1px dashed #888;
 }
 .ayu ul#searchresults li.focus {
  background-color: #252932;
 }
 .ayu mark {
  background-color: #e3b171;
 }
@media only print {
  #sidebar,
  #menu-bar,
@ -1243,3 +1377,66 @@ html:not(.sidebar-visible) #menu-bar:not(:hover).folded > #menu-bar-sticky-conta
 .tooltipped .tooltiptext {
  visibility: visible;
 }
 #searchresults a {
  text-decoration: none;
 }
 mark {
  border-radius: 2px;
  padding: 0 3px 1px 3px;
  margin: 0 -3px -1px -3px;
  -webkit-transition: background-color 300ms linear;
  -moz-transition: background-color 300ms linear;
  -o-transition: background-color 300ms linear;
  -ms-transition: background-color 300ms linear;
  transition: background-color 300ms linear;
 }
 .fade-out {
  background-color: rgba(0,0,0,0) !important;
 }
 .searchbar-outer {
  display: none;
  margin-left: auto;
  margin-right: auto;
  max-width: 750px;
 }
 #searchbar {
  display: block;
  width: 100%;
  margin: 5px auto 0px auto;
  padding: 10px 16px;
  -webkit-transition: box-shadow 300ms ease-in-out;
  -moz-transition: box-shadow 300ms ease-in-out;
  -o-transition: box-shadow 300ms ease-in-out;
  -ms-transition: box-shadow 300ms ease-in-out;
  transition: box-shadow 300ms ease-in-out;
 }
 .searchresults-header {
  font-weight: bold;
  font-size: 1em;
  padding: 18px 0 0 5px;
 }
 .searchresults-outer {
  display: none;
  margin-left: auto;
  margin-right: auto;
  max-width: 750px;
 }
 ul#searchresults {
  list-style: none;
  padding-left: 20px;
 }
 ul#searchresults li {
  margin: 10px 0px;
  padding: 2px;
  border-radius: 2px;
 }
 ul#searchresults span.teaser {
  display: block;
  clear: both;
  margin: 5px 0 0 20px;
  font-size: 0.8em;
 }
 ul#searchresults span.teaser em {
  font-weight: bold;
  font-style: normal;
 }
--- a/src/theme/book.js
+++ b/src/theme/book.js
@ -499,6 +499,7 @@ function playpen_text(playpen) {
 (function chapterNavigation() {
    document.addEventListener('keydown', function (e) {
        if (e.altKey || e.ctrlKey || e.metaKey || e.shiftKey) { return; }
        if (window.search && window.search.hasFocus()) { return; }
        switch (e.key) {
            case 'ArrowRight':
--- a/src/theme/index.hbs
+++ b/src/theme/index.hbs
@ -1,6 +1,7 @@
 <!DOCTYPE HTML>
 <html lang="{{ language }}" class="sidebar-visible">
    <head>
        <!-- Book generated using mdBook -->
        <meta charset="UTF-8">
        <title>{{ title }}</title>
        <meta content="text/html; charset=utf-8" http-equiv="Content-Type">
@ -112,9 +113,14 @@
                                <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>
-                        <h1 class="menu-title">{{ book_title }}</h1>
+                        <h1 class="menu-title">{{ book_title }}</h1> 
                        <div class="right-buttons">
                            <a href="print.html" title="Print this book" aria-label="Print this book">
@ -124,6 +130,17 @@
                    </div>
                </div>
                {{#if search_enabled}}
                <div id="searchbar-outer" class="searchbar-outer">
                    <input type="search" id="searchbar" name="searchbar" placeholder="Search this book ..." aria-controls="searchresults-outer" aria-describedby="searchresults-header">
                </div>
                <div id="searchresults-outer" class="searchresults-outer">
                    <div class="searchresults-header" id="searchresults-header"></div>
                    <ul id="searchresults">
                    </ul>
                </div>
                {{/if}}
                <!-- Apply ARIA attributes after the sidebar and the sidebar toggle button are added to the DOM -->
                <script type="text/javascript">
                    document.getElementById('sidebar-toggle').setAttribute('aria-expanded', sidebar === 'visible');
@ -221,12 +238,21 @@
        </script>
        {{/if}}
-        {{#if playpens_editable}}
+        {{#if playpen_js}}
-        <script src="{{ ace_js }}" type="text/javascript" charset="utf-8"></script>
+        <script src="ace.js" type="text/javascript" charset="utf-8"></script>
-        <script src="{{ editor_js }}" type="text/javascript" charset="utf-8"></script>
+        <script src="editor.js" type="text/javascript" charset="utf-8"></script>
-        <script src="{{ mode_rust_js }}" type="text/javascript" charset="utf-8"></script>
+        <script src="mode-rust.js" type="text/javascript" charset="utf-8"></script>
-        <script src="{{ theme_dawn_js }}" type="text/javascript" charset="utf-8"></script>
+        <script src="theme-dawn.js" type="text/javascript" charset="utf-8"></script>
-        <script src="{{ theme_tomorrow_night_js }}" type="text/javascript" charset="utf-8"></script>
+        <script src="theme-tomorrow_night.js" type="text/javascript" charset="utf-8"></script>
        {{/if}}
        {{#if search_enabled}}
        <script src="searchindex.js" type="text/javascript" charset="utf-8"></script>
        {{/if}}
        {{#if search_js}}
        <script src="elasticlunr.min.js" type="text/javascript" charset="utf-8"></script>
        <script src="mark.min.js" type="text/javascript" charset="utf-8"></script>
        <script src="searcher.js" type="text/javascript" charset="utf-8"></script>
        {{/if}}
        {{#if is_print}}
--- a/src/theme/mod.rs
+++ b/src/theme/mod.rs
@ -1,6 +1,10 @@
-#![allow(missing_docs)] // FIXME: Document this
+#![allow(missing_docs)]
 pub mod playpen_editor;
 #[cfg(feature = "search")]
 pub mod searcher;
 use std::path::Path;
 use std::fs::File;
 use std::io::Read;
@ -52,6 +56,8 @@ pub struct Theme {
 }
 impl Theme {
    /// Creates a `Theme` from the given `theme_dir`.
    /// If a file is found in the theme dir, it will override the default version.
    pub fn new<P: AsRef<Path>>(theme_dir: P) -> Self {
        let theme_dir = theme_dir.as_ref();
        let mut theme = Theme::default();
--- a/src/theme/playpen_editor/mod.rs
+++ b/src/theme/playpen_editor/mod.rs
@ -1,70 +1,7 @@
-use std::path::Path;
+//! Theme dependencies for the playpen editor.
 use theme::load_file_contents;
 pub static JS: &'static [u8] = include_bytes!("editor.js");
 pub static ACE_JS: &'static [u8] = include_bytes!("ace.js");
 pub static MODE_RUST_JS: &'static [u8] = include_bytes!("mode-rust.js");
 pub static THEME_DAWN_JS: &'static [u8] = include_bytes!("theme-dawn.js");
 pub static THEME_TOMORROW_NIGHT_JS: &'static [u8] = include_bytes!("theme-tomorrow_night.js");
 /// Integration of a JavaScript editor for playpens.
 /// Uses the Ace editor: https://ace.c9.io/.
 /// The Ace editor itself, the mode, and the theme files are the
 /// generated minified no conflict versions.
 ///
 /// The `PlaypenEditor` struct should be used instead of the static variables because
 /// the `new()` method
 /// will look if the user has an editor directory in his source folder and use
 /// the users editor instead
 /// of the default.
 ///
 /// You should exceptionnaly use the static variables only if you need the
 /// default editor even if the
 /// user has specified another editor.
 pub struct PlaypenEditor {
    pub js: Vec<u8>,
    pub ace_js: Vec<u8>,
    pub mode_rust_js: Vec<u8>,
    pub theme_dawn_js: Vec<u8>,
    pub theme_tomorrow_night_js: Vec<u8>,
 }
 impl PlaypenEditor {
    pub fn new(src: &Path) -> Self {
        let mut editor = PlaypenEditor {
            js: JS.to_owned(),
            ace_js: ACE_JS.to_owned(),
            mode_rust_js: MODE_RUST_JS.to_owned(),
            theme_dawn_js: THEME_DAWN_JS.to_owned(),
            theme_tomorrow_night_js: THEME_TOMORROW_NIGHT_JS.to_owned(),
        };
        // Check if the given path exists
        if !src.exists() || !src.is_dir() {
            return editor;
        }
        // Check for individual files if they exist
        {
            let files = vec![(src.join("editor.js"), &mut editor.js),
                             (src.join("ace.js"), &mut editor.ace_js),
                             (src.join("mode-rust.js"), &mut editor.mode_rust_js),
                             (src.join("theme-dawn.js"), &mut editor.theme_dawn_js),
                             (src.join("theme-tomorrow_night.js"),
                             &mut editor.theme_tomorrow_night_js)];
            for (filename, dest) in files {
                if !filename.exists() {
                    continue;
                }
                if let Err(e) = load_file_contents(&filename, dest) {
                    warn!("Couldn't load custom file, {}: {}", filename.display(), e);
                }
            }
        }
        editor
    }
 }
--- a/src/theme/searcher/elasticlunr.min.js
+++ b/src/theme/searcher/elasticlunr.min.js
--- a/src/theme/searcher/mark.min.js
+++ b/src/theme/searcher/mark.min.js
--- a/src/theme/searcher/mod.rs
+++ b/src/theme/searcher/mod.rs
@ -0,0 +1,6 @@
 //! Theme dependencies for in-browser search. Not included in mdbook when
 //! the "search" cargo feature is disabled.
 pub static JS: &'static [u8] = include_bytes!("searcher.js");
 pub static MARK_JS: &'static [u8] = include_bytes!("mark.min.js");
 pub static ELASTICLUNR_JS: &'static [u8] = include_bytes!("elasticlunr.min.js");
--- a/src/theme/searcher/searcher.js
+++ b/src/theme/searcher/searcher.js
@ -0,0 +1,457 @@
 window.search = window.search || {};
 (function search(search) {
    // Search functionality
    //
    // You can use !hasFocus() to prevent keyhandling in your key
    // event handlers while the user is typing his search.
    if (!Mark || !elasticlunr) {
        return;
    }
    var searchbar = document.getElementById('searchbar'),
        searchbar_outer = document.getElementById('searchbar-outer'),
        searchresults = document.getElementById('searchresults'),
        searchresults_outer = document.getElementById('searchresults-outer'),
        searchresults_header = document.getElementById('searchresults-header'),
        searchicon = document.getElementById('search-toggle'),
        content = document.getElementById('content'),
        searchindex = null,
        searchoptions = {
            bool: "AND",
            expand: true,
            teaser_word_count: 30,
            limit_results: 30,
            fields: {
                title: {boost: 1},
                body: {boost: 1},
                breadcrumbs: {boost: 0}
            }
        },
        mark_exclude = [],
        marker = new Mark(content),
        current_searchterm = "",
        URL_SEARCH_PARAM = 'search',
        URL_MARK_PARAM = 'highlight',
        teaser_count = 0,
        SEARCH_HOTKEY_KEYCODE = 83,
        ESCAPE_KEYCODE = 27,
        DOWN_KEYCODE = 40,
        UP_KEYCODE = 38,
        SELECT_KEYCODE = 13;
    function hasFocus() {
        return searchbar === document.activeElement;
    }
    function removeChildren(elem) {
        while (elem.firstChild) {
            elem.removeChild(elem.firstChild);
        }
    }
    // Helper to parse a url into its building blocks.
    function parseURL(url) {
        var a =  document.createElement('a');
        a.href = url;
        return {
            source: url,
            protocol: a.protocol.replace(':',''),
            host: a.hostname,
            port: a.port,
            params: (function(){
                var ret = {};
                var seg = a.search.replace(/^\?/,'').split('&');
                var len = seg.length, i = 0, s;
                for (;i<len;i++) {
                    if (!seg[i]) { continue; }
                    s = seg[i].split('=');
                    ret[s[0]] = s[1];
                }
                return ret;
            })(),
            file: (a.pathname.match(/\/([^/?#]+)$/i) || [,''])[1],
            hash: a.hash.replace('#',''),
            path: a.pathname.replace(/^([^/])/,'/$1')
        };
    }
    // Helper to recreate a url string from its building blocks.
    function renderURL(urlobject) {
        var url = urlobject.protocol + "://" + urlobject.host;
        if (urlobject.port != "") {
            url += ":" + urlobject.port;
        }
        url += urlobject.path;
        var joiner = "?";
        for(var prop in urlobject.params) {
            if(urlobject.params.hasOwnProperty(prop)) {
                url += joiner + prop + "=" + urlobject.params[prop];
                joiner = "&";
            }
        }
        if (urlobject.hash != "") {
            url += "#" + urlobject.hash;
        }
        return url;
    }
    // Helper to escape html special chars for displaying the teasers
    var escapeHTML = (function() {
        var MAP = {
            '&': '&amp;',
            '<': '&lt;',
            '>': '&gt;',
            '"': '&#34;',
            "'": '&#39;'
        };
        var repl = function(c) { return MAP[c]; };
        return function(s) {
            return s.replace(/[&<>'"]/g, repl);
        };
    })();
    function formatSearchMetric(count, searchterm) {
        if (count == 1) {
            return count + " search result for '" + searchterm + "':";
        } else if (count == 0) {
            return "No search results for '" + searchterm + "'.";
        } else {
            return count + " search results for '" + searchterm + "':";
        }
    }
    function formatSearchResult(result, searchterms) {
        var teaser = makeTeaser(escapeHTML(result.doc.body), searchterms);
        teaser_count++;
        // The ?URL_MARK_PARAM= parameter belongs inbetween the page and the #heading-anchor
        var url = result.ref.split("#");
        if (url.length == 1) { // no anchor found
            url.push("");
        }
        return '<a href="' + url[0] + '?' + URL_MARK_PARAM + '=' + searchterms + '#' + url[1]
            + '" aria-details="teaser_' + teaser_count + '">' + result.doc.breadcrumbs + '</a>'
            + '<span class="teaser" id="teaser_' + teaser_count + '" aria-label="Search Result Teaser">' 
            + teaser + '</span>';
    }
    function makeTeaser(body, searchterms) {
        // The strategy is as follows:
        // First, assign a value to each word in the document:
        //  Words that correspond to search terms (stemmer aware): 40
        //  Normal words: 2
        //  First word in a sentence: 8
        // Then use a sliding window with a constant number of words and count the
        // sum of the values of the words within the window. Then use the window that got the
        // maximum sum. If there are multiple maximas, then get the last one.
        // Enclose the terms in <em>.
        var stemmed_searchterms = searchterms.map(function(w) {
            return elasticlunr.stemmer(w.toLowerCase());
        });
        var searchterm_weight = 40;
        var weighted = []; // contains elements of ["word", weight, index_in_document]
        // split in sentences, then words
        var sentences = body.toLowerCase().split('. ');
        var index = 0;
        var value = 0;
        var searchterm_found = false;
        for (var sentenceindex in sentences) {
            var words = sentences[sentenceindex].split(' ');
            value = 8;
            for (var wordindex in words) {
                var word = words[wordindex];
                if (word.length > 0) {
                    for (var searchtermindex in stemmed_searchterms) {
                        if (elasticlunr.stemmer(word).startsWith(stemmed_searchterms[searchtermindex])) {
                            value = searchterm_weight;
                            searchterm_found = true;
                        }
                    };
                    weighted.push([word, value, index]);
                    value = 2;
                }
                index += word.length;
                index += 1; // ' ' or '.' if last word in sentence
            };
            index += 1; // because we split at a two-char boundary '. '
        };
        if (weighted.length == 0) {
            return body;
        }
        var window_weight = [];
        var window_size = Math.min(weighted.length, searchoptions.teaser_word_count);
        var cur_sum = 0;
        for (var wordindex = 0; wordindex < window_size; wordindex++) {
            cur_sum += weighted[wordindex][1];
        };
        window_weight.push(cur_sum);
        for (var wordindex = 0; wordindex < weighted.length - window_size; wordindex++) {
            cur_sum -= weighted[wordindex][1];
            cur_sum += weighted[wordindex + window_size][1];
            window_weight.push(cur_sum);
        };
        if (searchterm_found) {
            var max_sum = 0;
            var max_sum_window_index = 0;
            // backwards
            for (var i = window_weight.length - 1; i >= 0; i--) {
                if (window_weight[i] > max_sum) {
                    max_sum = window_weight[i];
                    max_sum_window_index = i;
                }
            };
        } else {
            max_sum_window_index = 0;
        }
        // add <em/> around searchterms
        var teaser_split = [];
        var index = weighted[max_sum_window_index][2];
        for (var i = max_sum_window_index; i < max_sum_window_index+window_size; i++) {
            var word = weighted[i];
            if (index < word[2]) {
                // missing text from index to start of `word`
                teaser_split.push(body.substring(index, word[2]));
                index = word[2];
            }
            if (word[1] == searchterm_weight) {
                teaser_split.push("<em>")
            }
            index = word[2] + word[0].length;
            teaser_split.push(body.substring(word[2], index));
            if (word[1] == searchterm_weight) {
                teaser_split.push("</em>")
            }
        };
        return teaser_split.join('');
    }
    function init() {
        searchoptions = window.search.searchoptions;
        searchindex = elasticlunr.Index.load(window.search.index);
        // Set up events
        searchicon.addEventListener('click', function(e) { searchIconClickHandler(); }, false);
        searchbar.addEventListener('keyup', function(e) { searchbarKeyUpHandler(); }, false);
        document.addEventListener('keydown', function (e) { globalKeyHandler(e); }, false);
        // If the user uses the browser buttons, do the same as if a reload happened
        window.onpopstate = function(e) { doSearchOrMarkFromUrl(); };
        // If reloaded, do the search or mark again, depending on the current url parameters
        doSearchOrMarkFromUrl();
    }
    function unfocusSearchbar() {
        // hacky, but just focusing a div only works once
        var tmp = document.createElement('input');
        tmp.setAttribute('style', 'position: absolute; opacity: 0;');
        searchicon.appendChild(tmp);
        tmp.focus();
        tmp.remove();
    }
    // On reload or browser history backwards/forwards events, parse the url and do search or mark
    function doSearchOrMarkFromUrl() {
        // Check current URL for search request
        var url = parseURL(window.location.href);
        if (url.params.hasOwnProperty(URL_SEARCH_PARAM)
            && url.params[URL_SEARCH_PARAM] != "") {
            showSearch(true);
            searchbar.value = decodeURIComponent(
                (url.params[URL_SEARCH_PARAM]+'').replace(/\+/g, '%20'));
            searchbarKeyUpHandler(); // -> doSearch()
        } else {
            showSearch(false);
        }
        if (url.params.hasOwnProperty(URL_MARK_PARAM)) {
            var words = url.params[URL_MARK_PARAM].split(' ');
            marker.mark(words, {
                exclude: mark_exclude
            });
            var markers = document.querySelectorAll("mark");
            function hide() {
                for (var i = 0; i < markers.length; i++) {
                    markers[i].classList.add("fade-out");
                    window.setTimeout(function(e) { marker.unmark(); }, 300);
                }
            }
            for (var i = 0; i < markers.length; i++) {
                markers[i].addEventListener('click', hide);
            }
        }
    }
    // Eventhandler for keyevents on `document`
    function globalKeyHandler(e) {
        if (e.altKey || e.ctrlKey || e.metaKey || e.shiftKey) { return; }
        if (e.keyCode == ESCAPE_KEYCODE) {
            e.preventDefault();
            searchbar.classList.remove("active");
            setSearchUrlParameters("",
                (searchbar.value.trim() != "") ? "push" : "replace");
            if (hasFocus()) {
                unfocusSearchbar();
            }
            showSearch(false);
            marker.unmark();
            return;
        }
        if (!hasFocus() && e.keyCode == SEARCH_HOTKEY_KEYCODE) {
            e.preventDefault();
            showSearch(true);
            window.scrollTo(0, 0);
            searchbar.focus();
            return;
        }
        if (hasFocus() && e.keyCode == DOWN_KEYCODE) {
            e.preventDefault();
            unfocusSearchbar();
            searchresults.children('li').first().classList.add("focus");
            return;
        }
        if (!hasFocus() && (e.keyCode == DOWN_KEYCODE
                            || e.keyCode == UP_KEYCODE
                            || e.keyCode == SELECT_KEYCODE)) {
            // not `:focus` because browser does annoying scrolling
            var current_focus = search.searchresults.find("li.focus");
            if (current_focus.length == 0) return;
            e.preventDefault();
            if (e.keyCode == DOWN_KEYCODE) {
                var next = current_focus.next()
                if (next.length > 0) {
                    current_focus.classList.remove("focus");
                    next.classList.add("focus");
                }
            } else if (e.keyCode == UP_KEYCODE) {
                current_focus.classList.remove("focus");
                var prev = current_focus.prev();
                if (prev.length == 0) {
                    searchbar.focus();
                } else {
                    prev.classList.add("focus");
                }
            } else {
                window.location = current_focus.children('a').attr('href');
            }
        }
    }
    function showSearch(yes) {
        if (yes) {
            searchbar_outer.style.display = 'block';
            searchicon.setAttribute('aria-expanded', 'true');
        } else {
            searchbar_outer.style.display = 'none';
            searchresults_outer.style.display = 'none';
            searchbar.value = '';
            removeChildren(searchresults);
            searchicon.setAttribute('aria-expanded', 'false');
        }
    }
    function showResults(yes) {
        if (yes) {
            searchbar_outer.style.display = 'block';
            searchresults_outer.style.display = 'block';
        } else {
            searchresults_outer.style.display = 'none';
        }
    }
    // Eventhandler for search icon
    function searchIconClickHandler() {
        if (searchbar_outer.style.display === 'block') {
            showSearch(false);
        } else {
            showSearch(true);
            window.scrollTo(0, 0);
            searchbar.focus();
        }
    }
    // Eventhandler for keyevents while the searchbar is focused
    function searchbarKeyUpHandler() {
        var searchterm = searchbar.value.trim();
        if (searchterm != "") {
            searchbar.classList.add("active");
            doSearch(searchterm);
        } else {
            searchbar.classList.remove("active");
            showResults(false);
            removeChildren(searchresults);
        }
        setSearchUrlParameters(searchterm, "push_if_new_search_else_replace");
        // Remove marks
        marker.unmark();
    }
    // Update current url with ?URL_SEARCH_PARAM= parameter, remove ?URL_MARK_PARAM and #heading-anchor .
    // `action` can be one of "push", "replace", "push_if_new_search_else_replace"
    // and replaces or pushes a new browser history item.
    // "push_if_new_search_else_replace" pushes if there is no `?URL_SEARCH_PARAM=abc` yet.
    function setSearchUrlParameters(searchterm, action) {
        var url = parseURL(window.location.href);
        var first_search = ! url.params.hasOwnProperty(URL_SEARCH_PARAM);
        if (searchterm != "" || action == "push_if_new_search_else_replace") {
            url.params[URL_SEARCH_PARAM] = searchterm;
            delete url.params[URL_MARK_PARAM];
            url.hash = "";
        } else {
            delete url.params[URL_SEARCH_PARAM];
        }
        // A new search will also add a new history item, so the user can go back
        // to the page prior to searching. A updated search term will only replace
        // the url.
        if (action == "push" || (action == "push_if_new_search_else_replace" && first_search) ) {
            history.pushState({}, document.title, renderURL(url));
        } else if (action == "replace" || (action == "push_if_new_search_else_replace" && !first_search) ) {
            history.replaceState({}, document.title, renderURL(url));
        }
    }
    function doSearch(searchterm) {
        // Don't search the same twice
        if (current_searchterm == searchterm) { return; }
        else { current_searchterm = searchterm; }
        if (searchindex == null) { return; }
        // Do the actual search
        var results = searchindex.search(searchterm, searchoptions);
        var resultcount = Math.min(results.length, searchoptions.limit_results);
        // Display search metrics
        searchresults_header.innerText = formatSearchMetric(resultcount, searchterm);
        // Clear and insert results
        var searchterms  = searchterm.split(' ');
        removeChildren(searchresults);
        for(var i = 0; i < resultcount ; i++){
            var resultElem = document.createElement('li');
            resultElem.innerHTML = formatSearchResult(results[i], searchterms);
            searchresults.appendChild(resultElem);
        }
        // Display results
        showResults(true);
    }
    init();
    // Exported functions
    search.hasFocus = hasFocus;
 })(window.search);
--- a/src/theme/stylus/book.styl
+++ b/src/theme/stylus/book.styl
@ -9,3 +9,4 @@
@import 'themes'
@import 'print'
@import 'tooltip'
@import 'searchbar'
--- a/src/theme/stylus/general.styl
+++ b/src/theme/stylus/general.styl
@ -35,6 +35,16 @@ h4, h5 { margin-top: 2em }
 .header + .header h3, .header + .header h4, .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 {
    display: inline-block;
    content: "»";
    margin-left: -30px;
    width: 30px;
 }
 table {
    margin: 0 auto;
    border-collapse: collapse;
--- a/src/theme/stylus/searchbar.styl
+++ b/src/theme/stylus/searchbar.styl
@ -0,0 +1,67 @@
@require 'variables'
 #searchresults a {
    text-decoration: none;
 }
 mark {
    border-radius: 2px;
    padding: 0 3px 1px 3px;
    margin: 0 -3px -1px -3px;
    transition: background-color 300ms linear;
 }
 .fade-out {
    background-color: rgba(0,0,0,0) !important
 }
 .searchbar-outer {
    display: none;
    margin-left: auto;
    margin-right: auto;
    max-width: $content-max-width;
 }
 #searchbar {
    display: block;
    width: 100%;
    margin: 5px auto 0px auto;
    padding: 10px 16px;
    transition: box-shadow 300ms ease-in-out;
 }
 .searchresults-header {
    font-weight: bold;
    font-size: 1em;
    padding: 18px 0 0 5px;
 }
 .searchresults-outer {
    display: none;
    margin-left: auto;
    margin-right: auto;
    max-width: $content-max-width;
 }
 ul#searchresults {
    list-style: none;
    padding-left: 20px;
    li {
        margin: 10px 0px;
        padding: 2px;
        border-radius: 2px;
    }
    span.teaser {
        display: block;
        clear: both;
        margin: 5px 0 0 20px;
        font-size: 0.8em;
    }
    span.teaser em {
        font-weight: bold;
        font-style: normal;
    }
 }
--- a/src/theme/stylus/themes/ayu.styl
+++ b/src/theme/stylus/themes/ayu.styl
@ -29,4 +29,13 @@ $table-border-color = lighten($bg, 5%)
 $table-header-bg = lighten($bg, 20%)
 $table-alternate-bg = lighten($bg, 3%)
 $searchbar-border-color = #848484
 $searchbar-bg = #424242
 $searchbar-fg = #fff
 $searchbar-shadow-color = #d4c89f
 $searchresults-header-fg = #666
 $searchresults-border-color = #888
 $searchresults-li-bg = #252932
 $search-mark-bg = #e3b171
@import 'base'
--- a/src/theme/stylus/themes/base.styl
+++ b/src/theme/stylus/themes/base.styl
@ -84,7 +84,10 @@
        background-color: $sidebar-bg
    }
-    .content a:link, a:visited, a > .hljs {
+    #searchresults a,
    .content a:link,
    a:visited,
    a > .hljs {
        color: $links
    }
@ -188,4 +191,32 @@
    ::-webkit-scrollbar-thumb {
        background: $scrollbar;
    }
    /* Search */
    #searchbar {
        border: 1px solid $searchbar-border-color;
        border-radius: 3px;
        background-color: $searchbar-bg;
        color: $searchbar-fg
        &:focus, &.active {
            box-shadow: 0 0 3px $searchbar-shadow-color;
        }
    }
    .searchresults-header {
        color: $searchresults-header-fg;
    }
    .searchresults-outer {
        border-bottom: 1px dashed $searchresults-border-color;
    }
    ul#searchresults li.focus {
        background-color: $searchresults-li-bg;
    }
    mark {
        background-color: $search-mark-bg;
    }
 }
--- a/src/theme/stylus/themes/coal.styl
+++ b/src/theme/stylus/themes/coal.styl
@ -29,4 +29,13 @@ $table-border-color = lighten($bg, 5%)
 $table-header-bg = lighten($bg, 20%)
 $table-alternate-bg = lighten($bg, 3%)
 $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
@import 'base'
--- a/src/theme/stylus/themes/light.styl
+++ b/src/theme/stylus/themes/light.styl
@ -16,7 +16,7 @@ $icons-hover = #333333
 $links = #4183c4
-$inline-code-color = #6e6b5e;
+$inline-code-color = #6e6b5e
 $theme-popup-bg = #fafafa
 $theme-popup-border = #cccccc
@ -29,4 +29,13 @@ $table-border-color = darken($bg, 5%)
 $table-header-bg = darken($bg, 20%)
 $table-alternate-bg = darken($bg, 3%)
 $searchbar-border-color = #aaa
 $searchbar-bg = #fafafa
 $searchbar-fg = #000
 $searchbar-shadow-color = #aaa
 $searchresults-header-fg = #666
 $searchresults-border-color = #888
 $searchresults-li-bg = #e4f2fe
 $search-mark-bg = #a2cff5
@import 'base'
--- a/src/theme/stylus/themes/navy.styl
+++ b/src/theme/stylus/themes/navy.styl
@ -29,4 +29,13 @@ $table-border-color = lighten($bg, 5%)
 $table-header-bg = lighten($bg, 20%)
 $table-alternate-bg = lighten($bg, 3%)
 $searchbar-border-color = #aaa
 $searchbar-bg = #aeaec6
 $searchbar-fg = #000
 $searchbar-shadow-color = #aaa
 $searchresults-header-fg = #5f5f71
 $searchresults-border-color = #5c5c68
 $searchresults-li-bg = #242430
 $search-mark-bg = #a2cff5
@import 'base'
--- a/src/theme/stylus/themes/rust.styl
+++ b/src/theme/stylus/themes/rust.styl
@ -29,4 +29,13 @@ $table-border-color = darken($bg, 5%)
 $table-header-bg = #b3a497
 $table-alternate-bg = darken($bg, 3%)
 $searchbar-border-color = #aaa
 $searchbar-bg = #fafafa
 $searchbar-fg = #000
 $searchbar-shadow-color = #aaa
 $searchresults-header-fg = #666
 $searchresults-border-color = #888
 $searchresults-li-bg = #dec2a2
 $search-mark-bg = #e69f67
@import 'base'
--- a/src/utils/fs.rs
+++ b/src/utils/fs.rs
@ -1,7 +1,7 @@
 use std::path::{Component, Path, PathBuf};
 use errors::*;
 use std::io::Read;
 use std::fs::{self, File};
 use std::io::{Read, Write};
 use std::path::{Component, Path, PathBuf};
 /// Takes a path to a file and try to read the file into a String
 pub fn file_to_string<P: AsRef<Path>>(path: P) -> Result<String> {
@ -16,6 +16,27 @@ pub fn file_to_string<P: AsRef<Path>>(path: P) -> Result<String> {
    Ok(content)
 }
 /// Naively replaces any path seperator with a forward-slash '/'
 pub fn normalize_path(path: &str) -> String {
    use std::path::is_separator;
    path.chars()
        .map(|ch| if is_separator(ch) { '/' } else { ch })
        .collect::<String>()
 }
 /// Write the given data to a file, creating it first if necessary
 pub fn write_file<P: AsRef<Path>>(
    build_dir: &Path,
    filename: P,
    content: &[u8],
 ) -> Result<()> {
    let path = build_dir.join(filename);
    create_file(&path)?
        .write_all(content)
        .map_err(|e| e.into())
 }
 /// Takes a path and returns a path containing just enough `../` to point to
 /// the root of the given path.
 ///
@ -38,7 +59,6 @@ pub fn file_to_string<P: AsRef<Path>>(path: P) -> Result<String> {
 /// it doesn't return the correct path.
 /// Consider [submitting a new issue](https://github.com/rust-lang-nursery/mdBook/issues)
 /// or a [pull-request](https://github.com/rust-lang-nursery/mdBook/pulls) to improve it.
 pub fn path_to_root<P: Into<PathBuf>>(path: P) -> String {
    debug!("path_to_root");
    // Remove filename and add "../" for every directory
@ -61,7 +81,6 @@ pub fn path_to_root<P: Into<PathBuf>>(path: P) -> String {
 /// This function creates a file and returns it. But before creating the file
 /// it checks every directory in the path to see if it exists,
 /// and if it does not it will be created.
 pub fn create_file(path: &Path) -> Result<File> {
    debug!("Creating {}", path.display());
@ -76,7 +95,6 @@ pub fn create_file(path: &Path) -> Result<File> {
 }
 /// Removes all the content of a directory but not the directory itself
 pub fn remove_dir_content(dir: &Path) -> Result<()> {
    for item in fs::read_dir(dir)? {
        if let Ok(item) = item {
@ -93,7 +111,6 @@ pub fn remove_dir_content(dir: &Path) -> Result<()> {
 /// Copies all files of a directory to another one except the files
 /// with the extensions given in the `ext_blacklist` array
 pub fn copy_files_except_ext(
    from: &Path,
    to: &Path,
--- a/src/utils/mod.rs
+++ b/src/utils/mod.rs
@ -3,13 +3,71 @@
 pub mod fs;
 mod string;
 use errors::Error;
 use regex::Regex;
 use pulldown_cmark::{html, Event, Options, Parser, Tag, OPTION_ENABLE_FOOTNOTES,
                     OPTION_ENABLE_TABLES};
 use std::borrow::Cow;
 pub use self::string::{RangeArgument, take_lines};
 /// Replaces multiple consecutive whitespace characters with a single space character.
 pub fn collapse_whitespace<'a>(text: &'a str) -> Cow<'a, str> {
    lazy_static! {
        static ref RE: Regex = Regex::new(r"\s\s+").unwrap();
    }
    RE.replace_all(text, " ")
 }
 /// Convert the given string to a valid HTML element ID
 pub fn normalize_id(content: &str) -> String {
    let mut ret = content
        .chars()
        .filter_map(|ch| {
            if ch.is_alphanumeric() || ch == '_' || ch == '-' {
                Some(ch.to_ascii_lowercase())
            } else if ch.is_whitespace() {
                Some('-')
            } else {
                None
            }
        })
        .collect::<String>();
    // Ensure that the first character is [A-Za-z]
    if ret.chars().next().map_or(false, |c| !c.is_ascii_alphabetic()) {
        ret.insert(0, 'a');
    }
    ret
 }
 /// Generate an ID for use with anchors which is derived from a "normalised"
 /// string.
 pub fn id_from_content(content: &str) -> String {
    let mut content = content.to_string();
    // Skip any tags or html-encoded stuff
    const REPL_SUB: &[&str] = &["<em>",
                                "</em>",
                                "<code>",
                                "</code>",
                                "<strong>",
                                "</strong>",
                                "&lt;",
                                "&gt;",
                                "&amp;",
                                "&#39;",
                                "&quot;"];
    for sub in REPL_SUB {
        content = content.replace(sub, "");
    }
    // Remove spaces and hashes indicating a header
    let trimmed = content.trim().trim_left_matches('#').trim();
    normalize_id(trimmed)
 }
 /// Wrapper around the pulldown-cmark parser for rendering markdown to HTML.
 pub fn render_markdown(text: &str, curly_quotes: bool) -> String {
    let mut s = String::with_capacity(text.len() * 3 / 2);
@ -212,6 +270,29 @@ more text with spaces
        }
    }
    mod html_munging {
        use super::super::{id_from_content, normalize_id};
        #[test]
        fn it_generates_anchors() {
            assert_eq!(id_from_content("## `--passes`: add more rustdoc passes"),
                    "a--passes-add-more-rustdoc-passes");
            assert_eq!(id_from_content("## Method-call expressions"),
                    "method-call-expressions");
        }
        #[test]
        fn it_normalizes_ids() {
            assert_eq!(normalize_id("`--passes`: add more rustdoc passes"),
                    "a--passes-add-more-rustdoc-passes");
            assert_eq!(normalize_id("Method-call 🐙 expressions \u{1f47c}"),
                    "method-call--expressions-");
            assert_eq!(normalize_id("_-_12345"), "a_-_12345");
            assert_eq!(normalize_id("12345"), "a12345");
            assert_eq!(normalize_id(""), "");
        }
    }
    mod convert_quotes_to_curly {
        use super::super::convert_quotes_to_curly;
--- a/tests/alternate_backends.rs
+++ b/tests/alternate_backends.rs
@ -3,12 +3,11 @@
 extern crate mdbook;
 extern crate tempdir;
-use std::fs::File;
+#[cfg(not(windows))]
 use std::path::Path;
 use tempdir::TempDir;
 use mdbook::config::Config;
 use mdbook::MDBook;
 use mdbook::renderer::RenderContext;
 #[test]
 fn passing_alternate_backend() {
@ -39,6 +38,7 @@ fn alternate_backend_with_arguments() {
 }
 /// Get a command which will pipe `stdin` to the provided file.
 #[cfg(not(windows))]
 fn tee_command<P: AsRef<Path>>(out_file: P) -> String {
    let out_file = out_file.as_ref();
@ -52,6 +52,9 @@ fn tee_command<P: AsRef<Path>>(out_file: P) -> String {
 #[test]
 #[cfg(not(windows))]
 fn backends_receive_render_context_via_stdin() {
    use std::fs::File;
    use mdbook::renderer::RenderContext;
    let temp = TempDir::new("output").unwrap();
    let out_file = temp.path().join("out.txt");
    let cmd = tee_command(&out_file);
--- a/tests/dummy_book/src/conclusion.md
+++ b/tests/dummy_book/src/conclusion.md
@ -1 +1,20 @@
-# Conclusion
+# Conclusion
 <p>
 <!--secret secret-->
 I put &lt;HTML&gt; in here!<br/>
 </p>
 <script type="text/javascript" >
 // I probably shouldn't do this
 if (3 < 5 > 10)
 {
    alert("The sky is falling!");
 }
 </script >
 <style >
 /*
 css looks, like this {
    foo: < 3 <bar >
 }
 */
 </style>
--- a/tests/rendered_output.rs
+++ b/tests/rendered_output.rs
@ -339,3 +339,103 @@ fn book_with_a_reserved_filename_does_not_build() {
    let got = md.build();
    assert!(got.is_err());
 }
 #[cfg(feature = "search")]
 mod search {
    extern crate serde_json;
    use std::fs::File;
    use std::path::Path;
    use mdbook::utils::fs::file_to_string;
    use mdbook::MDBook;
    use dummy_book::DummyBook;
    fn read_book_index(root: &Path) -> serde_json::Value {
        let index = root.join("book/searchindex.js");
        let index = file_to_string(index).unwrap();
        let index = index.trim_left_matches("window.search = ");
        let index = index.trim_right_matches(";");
        serde_json::from_str(&index).unwrap()
    }
    #[test]
    fn book_creates_reasonable_search_index() {
        let temp = DummyBook::new().build().unwrap();
        let md = MDBook::load(temp.path()).unwrap();
        md.build().unwrap();
        let index = read_book_index(temp.path());
        let bodyidx = &index["index"]["index"]["body"]["root"];
        let textidx = &bodyidx["t"]["e"]["x"]["t"];
        assert_eq!(textidx["df"], 2);
        assert_eq!(textidx["docs"]["first/index.html#first-chapter"]["tf"], 1.0);
        assert_eq!(textidx["docs"]["intro.html#introduction"]["tf"], 1.0);
        let docs = &index["index"]["documentStore"]["docs"];
        assert_eq!(docs["first/index.html#first-chapter"]["body"], "more text.");
        assert_eq!(docs["first/index.html#some-section"]["body"], "");
        assert_eq!(
            docs["first/includes.html#summary"]["body"],
            "Introduction First Chapter Nested Chapter Includes Second Chapter Conclusion"
        );
        assert_eq!(
            docs["first/includes.html#summary"]["breadcrumbs"],
            "First Chapter » Summary"
        );
        assert_eq!(
            docs["conclusion.html#conclusion"]["body"],
            "I put &lt;HTML&gt; in here!"
        );
    }
    // Setting this to `true` may cause issues with `cargo watch`,
    // since it may not finish writing the fixture before the tests
    // are run again.
    const GENERATE_FIXTURE: bool = false;
    fn get_fixture() -> serde_json::Value {
        if GENERATE_FIXTURE {
            let temp = DummyBook::new().build().unwrap();
            let md = MDBook::load(temp.path()).unwrap();
            md.build().unwrap();
            let src = read_book_index(temp.path());
            let dest = Path::new(env!("CARGO_MANIFEST_DIR")).join("tests/searchindex_fixture.json");
            let dest = File::create(&dest).unwrap();
            serde_json::to_writer_pretty(dest, &src).unwrap();
            src
        } else {
            let json = include_str!("searchindex_fixture.json");
            serde_json::from_str(json).expect("Unable to deserialize the fixture")
        }
    }
    // So you've broken the test. If you changed dummy_book, it's probably
    // safe to regenerate the fixture. If you haven't then make sure that the
    // search index still works. Run `cargo run -- serve tests/dummy_book`
    // and try some searches. Are you getting results? Do the teasers look OK?
    // Are there new errors in the JS console?
    //
    // If you're pretty sure you haven't broken anything, change `GENERATE_FIXTURE`
    // above to `true`, and run `cargo test` to generate a new fixture. Then
    // change it back to `false`. Include the changed `searchindex_fixture.json` in your commit.
    #[test]
    fn search_index_hasnt_changed_accidentally() {
        let temp = DummyBook::new().build().unwrap();
        let md = MDBook::load(temp.path()).unwrap();
        md.build().unwrap();
        let book_index = read_book_index(temp.path());
        let fixture_index = get_fixture();
        // Uncomment this if you're okay with pretty-printing 32KB of JSON
        //assert_eq!(fixture_index, book_index);
        if book_index != fixture_index {
            panic!("The search index has changed from the fixture");
        }
    }
 }
--- a/tests/searchindex_fixture.json
+++ b/tests/searchindex_fixture.json