Mercurial > yakumo_izuru > aya
comparison vendor/github.com/russross/blackfriday/v2/README.md @ 66:787b5ee0289d draft
Use vendored modules
Signed-off-by: Izuru Yakumo <yakumo.izuru@chaotic.ninja>
| author | yakumo.izuru |
|---|---|
| date | Sun, 23 Jul 2023 13:18:53 +0000 |
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| 65:6d985efa0f7a | 66:787b5ee0289d |
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| 1 Blackfriday | |
| 2 [![Build Status][BuildV2SVG]][BuildV2URL] | |
| 3 [![PkgGoDev][PkgGoDevV2SVG]][PkgGoDevV2URL] | |
| 4 =========== | |
| 5 | |
| 6 Blackfriday is a [Markdown][1] processor implemented in [Go][2]. It | |
| 7 is paranoid about its input (so you can safely feed it user-supplied | |
| 8 data), it is fast, it supports common extensions (tables, smart | |
| 9 punctuation substitutions, etc.), and it is safe for all utf-8 | |
| 10 (unicode) input. | |
| 11 | |
| 12 HTML output is currently supported, along with Smartypants | |
| 13 extensions. | |
| 14 | |
| 15 It started as a translation from C of [Sundown][3]. | |
| 16 | |
| 17 | |
| 18 Installation | |
| 19 ------------ | |
| 20 | |
| 21 Blackfriday is compatible with modern Go releases in module mode. | |
| 22 With Go installed: | |
| 23 | |
| 24 go get github.com/russross/blackfriday/v2 | |
| 25 | |
| 26 will resolve and add the package to the current development module, | |
| 27 then build and install it. Alternatively, you can achieve the same | |
| 28 if you import it in a package: | |
| 29 | |
| 30 import "github.com/russross/blackfriday/v2" | |
| 31 | |
| 32 and `go get` without parameters. | |
| 33 | |
| 34 Legacy GOPATH mode is unsupported. | |
| 35 | |
| 36 | |
| 37 Versions | |
| 38 -------- | |
| 39 | |
| 40 Currently maintained and recommended version of Blackfriday is `v2`. It's being | |
| 41 developed on its own branch: https://github.com/russross/blackfriday/tree/v2 and the | |
| 42 documentation is available at | |
| 43 https://pkg.go.dev/github.com/russross/blackfriday/v2. | |
| 44 | |
| 45 It is `go get`-able in module mode at `github.com/russross/blackfriday/v2`. | |
| 46 | |
| 47 Version 2 offers a number of improvements over v1: | |
| 48 | |
| 49 * Cleaned up API | |
| 50 * A separate call to [`Parse`][4], which produces an abstract syntax tree for | |
| 51 the document | |
| 52 * Latest bug fixes | |
| 53 * Flexibility to easily add your own rendering extensions | |
| 54 | |
| 55 Potential drawbacks: | |
| 56 | |
| 57 * Our benchmarks show v2 to be slightly slower than v1. Currently in the | |
| 58 ballpark of around 15%. | |
| 59 * API breakage. If you can't afford modifying your code to adhere to the new API | |
| 60 and don't care too much about the new features, v2 is probably not for you. | |
| 61 * Several bug fixes are trailing behind and still need to be forward-ported to | |
| 62 v2. See issue [#348](https://github.com/russross/blackfriday/issues/348) for | |
| 63 tracking. | |
| 64 | |
| 65 If you are still interested in the legacy `v1`, you can import it from | |
| 66 `github.com/russross/blackfriday`. Documentation for the legacy v1 can be found | |
| 67 here: https://pkg.go.dev/github.com/russross/blackfriday. | |
| 68 | |
| 69 | |
| 70 Usage | |
| 71 ----- | |
| 72 | |
| 73 For the most sensible markdown processing, it is as simple as getting your input | |
| 74 into a byte slice and calling: | |
| 75 | |
| 76 ```go | |
| 77 output := blackfriday.Run(input) | |
| 78 ``` | |
| 79 | |
| 80 Your input will be parsed and the output rendered with a set of most popular | |
| 81 extensions enabled. If you want the most basic feature set, corresponding with | |
| 82 the bare Markdown specification, use: | |
| 83 | |
| 84 ```go | |
| 85 output := blackfriday.Run(input, blackfriday.WithNoExtensions()) | |
| 86 ``` | |
| 87 | |
| 88 ### Sanitize untrusted content | |
| 89 | |
| 90 Blackfriday itself does nothing to protect against malicious content. If you are | |
| 91 dealing with user-supplied markdown, we recommend running Blackfriday's output | |
| 92 through HTML sanitizer such as [Bluemonday][5]. | |
| 93 | |
| 94 Here's an example of simple usage of Blackfriday together with Bluemonday: | |
| 95 | |
| 96 ```go | |
| 97 import ( | |
| 98 "github.com/microcosm-cc/bluemonday" | |
| 99 "github.com/russross/blackfriday/v2" | |
| 100 ) | |
| 101 | |
| 102 // ... | |
| 103 unsafe := blackfriday.Run(input) | |
| 104 html := bluemonday.UGCPolicy().SanitizeBytes(unsafe) | |
| 105 ``` | |
| 106 | |
| 107 ### Custom options | |
| 108 | |
| 109 If you want to customize the set of options, use `blackfriday.WithExtensions`, | |
| 110 `blackfriday.WithRenderer` and `blackfriday.WithRefOverride`. | |
| 111 | |
| 112 ### `blackfriday-tool` | |
| 113 | |
| 114 You can also check out `blackfriday-tool` for a more complete example | |
| 115 of how to use it. Download and install it using: | |
| 116 | |
| 117 go get github.com/russross/blackfriday-tool | |
| 118 | |
| 119 This is a simple command-line tool that allows you to process a | |
| 120 markdown file using a standalone program. You can also browse the | |
| 121 source directly on github if you are just looking for some example | |
| 122 code: | |
| 123 | |
| 124 * <https://github.com/russross/blackfriday-tool> | |
| 125 | |
| 126 Note that if you have not already done so, installing | |
| 127 `blackfriday-tool` will be sufficient to download and install | |
| 128 blackfriday in addition to the tool itself. The tool binary will be | |
| 129 installed in `$GOPATH/bin`. This is a statically-linked binary that | |
| 130 can be copied to wherever you need it without worrying about | |
| 131 dependencies and library versions. | |
| 132 | |
| 133 ### Sanitized anchor names | |
| 134 | |
| 135 Blackfriday includes an algorithm for creating sanitized anchor names | |
| 136 corresponding to a given input text. This algorithm is used to create | |
| 137 anchors for headings when `AutoHeadingIDs` extension is enabled. The | |
| 138 algorithm has a specification, so that other packages can create | |
| 139 compatible anchor names and links to those anchors. | |
| 140 | |
| 141 The specification is located at https://pkg.go.dev/github.com/russross/blackfriday/v2#hdr-Sanitized_Anchor_Names. | |
| 142 | |
| 143 [`SanitizedAnchorName`](https://pkg.go.dev/github.com/russross/blackfriday/v2#SanitizedAnchorName) exposes this functionality, and can be used to | |
| 144 create compatible links to the anchor names generated by blackfriday. | |
| 145 This algorithm is also implemented in a small standalone package at | |
| 146 [`github.com/shurcooL/sanitized_anchor_name`](https://pkg.go.dev/github.com/shurcooL/sanitized_anchor_name). It can be useful for clients | |
| 147 that want a small package and don't need full functionality of blackfriday. | |
| 148 | |
| 149 | |
| 150 Features | |
| 151 -------- | |
| 152 | |
| 153 All features of Sundown are supported, including: | |
| 154 | |
| 155 * **Compatibility**. The Markdown v1.0.3 test suite passes with | |
| 156 the `--tidy` option. Without `--tidy`, the differences are | |
| 157 mostly in whitespace and entity escaping, where blackfriday is | |
| 158 more consistent and cleaner. | |
| 159 | |
| 160 * **Common extensions**, including table support, fenced code | |
| 161 blocks, autolinks, strikethroughs, non-strict emphasis, etc. | |
| 162 | |
| 163 * **Safety**. Blackfriday is paranoid when parsing, making it safe | |
| 164 to feed untrusted user input without fear of bad things | |
| 165 happening. The test suite stress tests this and there are no | |
| 166 known inputs that make it crash. If you find one, please let me | |
| 167 know and send me the input that does it. | |
| 168 | |
| 169 NOTE: "safety" in this context means *runtime safety only*. In order to | |
| 170 protect yourself against JavaScript injection in untrusted content, see | |
| 171 [this example](https://github.com/russross/blackfriday#sanitize-untrusted-content). | |
| 172 | |
| 173 * **Fast processing**. It is fast enough to render on-demand in | |
| 174 most web applications without having to cache the output. | |
| 175 | |
| 176 * **Thread safety**. You can run multiple parsers in different | |
| 177 goroutines without ill effect. There is no dependence on global | |
| 178 shared state. | |
| 179 | |
| 180 * **Minimal dependencies**. Blackfriday only depends on standard | |
| 181 library packages in Go. The source code is pretty | |
| 182 self-contained, so it is easy to add to any project, including | |
| 183 Google App Engine projects. | |
| 184 | |
| 185 * **Standards compliant**. Output successfully validates using the | |
| 186 W3C validation tool for HTML 4.01 and XHTML 1.0 Transitional. | |
| 187 | |
| 188 | |
| 189 Extensions | |
| 190 ---------- | |
| 191 | |
| 192 In addition to the standard markdown syntax, this package | |
| 193 implements the following extensions: | |
| 194 | |
| 195 * **Intra-word emphasis supression**. The `_` character is | |
| 196 commonly used inside words when discussing code, so having | |
| 197 markdown interpret it as an emphasis command is usually the | |
| 198 wrong thing. Blackfriday lets you treat all emphasis markers as | |
| 199 normal characters when they occur inside a word. | |
| 200 | |
| 201 * **Tables**. Tables can be created by drawing them in the input | |
| 202 using a simple syntax: | |
| 203 | |
| 204 ``` | |
| 205 Name | Age | |
| 206 --------|------ | |
| 207 Bob | 27 | |
| 208 Alice | 23 | |
| 209 ``` | |
| 210 | |
| 211 * **Fenced code blocks**. In addition to the normal 4-space | |
| 212 indentation to mark code blocks, you can explicitly mark them | |
| 213 and supply a language (to make syntax highlighting simple). Just | |
| 214 mark it like this: | |
| 215 | |
| 216 ```go | |
| 217 func getTrue() bool { | |
| 218 return true | |
| 219 } | |
| 220 ``` | |
| 221 | |
| 222 You can use 3 or more backticks to mark the beginning of the | |
| 223 block, and the same number to mark the end of the block. | |
| 224 | |
| 225 To preserve classes of fenced code blocks while using the bluemonday | |
| 226 HTML sanitizer, use the following policy: | |
| 227 | |
| 228 ```go | |
| 229 p := bluemonday.UGCPolicy() | |
| 230 p.AllowAttrs("class").Matching(regexp.MustCompile("^language-[a-zA-Z0-9]+$")).OnElements("code") | |
| 231 html := p.SanitizeBytes(unsafe) | |
| 232 ``` | |
| 233 | |
| 234 * **Definition lists**. A simple definition list is made of a single-line | |
| 235 term followed by a colon and the definition for that term. | |
| 236 | |
| 237 Cat | |
| 238 : Fluffy animal everyone likes | |
| 239 | |
| 240 Internet | |
| 241 : Vector of transmission for pictures of cats | |
| 242 | |
| 243 Terms must be separated from the previous definition by a blank line. | |
| 244 | |
| 245 * **Footnotes**. A marker in the text that will become a superscript number; | |
| 246 a footnote definition that will be placed in a list of footnotes at the | |
| 247 end of the document. A footnote looks like this: | |
| 248 | |
| 249 This is a footnote.[^1] | |
| 250 | |
| 251 [^1]: the footnote text. | |
| 252 | |
| 253 * **Autolinking**. Blackfriday can find URLs that have not been | |
| 254 explicitly marked as links and turn them into links. | |
| 255 | |
| 256 * **Strikethrough**. Use two tildes (`~~`) to mark text that | |
| 257 should be crossed out. | |
| 258 | |
| 259 * **Hard line breaks**. With this extension enabled newlines in the input | |
| 260 translate into line breaks in the output. This extension is off by default. | |
| 261 | |
| 262 * **Smart quotes**. Smartypants-style punctuation substitution is | |
| 263 supported, turning normal double- and single-quote marks into | |
| 264 curly quotes, etc. | |
| 265 | |
| 266 * **LaTeX-style dash parsing** is an additional option, where `--` | |
| 267 is translated into `–`, and `---` is translated into | |
| 268 `—`. This differs from most smartypants processors, which | |
| 269 turn a single hyphen into an ndash and a double hyphen into an | |
| 270 mdash. | |
| 271 | |
| 272 * **Smart fractions**, where anything that looks like a fraction | |
| 273 is translated into suitable HTML (instead of just a few special | |
| 274 cases like most smartypant processors). For example, `4/5` | |
| 275 becomes `<sup>4</sup>⁄<sub>5</sub>`, which renders as | |
| 276 <sup>4</sup>⁄<sub>5</sub>. | |
| 277 | |
| 278 | |
| 279 Other renderers | |
| 280 --------------- | |
| 281 | |
| 282 Blackfriday is structured to allow alternative rendering engines. Here | |
| 283 are a few of note: | |
| 284 | |
| 285 * [github_flavored_markdown](https://pkg.go.dev/github.com/shurcooL/github_flavored_markdown): | |
| 286 provides a GitHub Flavored Markdown renderer with fenced code block | |
| 287 highlighting, clickable heading anchor links. | |
| 288 | |
| 289 It's not customizable, and its goal is to produce HTML output | |
| 290 equivalent to the [GitHub Markdown API endpoint](https://developer.github.com/v3/markdown/#render-a-markdown-document-in-raw-mode), | |
| 291 except the rendering is performed locally. | |
| 292 | |
| 293 * [markdownfmt](https://github.com/shurcooL/markdownfmt): like gofmt, | |
| 294 but for markdown. | |
| 295 | |
| 296 * [LaTeX output](https://gitlab.com/ambrevar/blackfriday-latex): | |
| 297 renders output as LaTeX. | |
| 298 | |
| 299 * [bfchroma](https://github.com/Depado/bfchroma/): provides convenience | |
| 300 integration with the [Chroma](https://github.com/alecthomas/chroma) code | |
| 301 highlighting library. bfchroma is only compatible with v2 of Blackfriday and | |
| 302 provides a drop-in renderer ready to use with Blackfriday, as well as | |
| 303 options and means for further customization. | |
| 304 | |
| 305 * [Blackfriday-Confluence](https://github.com/kentaro-m/blackfriday-confluence): provides a [Confluence Wiki Markup](https://confluence.atlassian.com/doc/confluence-wiki-markup-251003035.html) renderer. | |
| 306 | |
| 307 * [Blackfriday-Slack](https://github.com/karriereat/blackfriday-slack): converts markdown to slack message style | |
| 308 | |
| 309 | |
| 310 TODO | |
| 311 ---- | |
| 312 | |
| 313 * More unit testing | |
| 314 * Improve Unicode support. It does not understand all Unicode | |
| 315 rules (about what constitutes a letter, a punctuation symbol, | |
| 316 etc.), so it may fail to detect word boundaries correctly in | |
| 317 some instances. It is safe on all UTF-8 input. | |
| 318 | |
| 319 | |
| 320 License | |
| 321 ------- | |
| 322 | |
| 323 [Blackfriday is distributed under the Simplified BSD License](LICENSE.txt) | |
| 324 | |
| 325 | |
| 326 [1]: https://daringfireball.net/projects/markdown/ "Markdown" | |
| 327 [2]: https://golang.org/ "Go Language" | |
| 328 [3]: https://github.com/vmg/sundown "Sundown" | |
| 329 [4]: https://pkg.go.dev/github.com/russross/blackfriday/v2#Parse "Parse func" | |
| 330 [5]: https://github.com/microcosm-cc/bluemonday "Bluemonday" | |
| 331 | |
| 332 [BuildV2SVG]: https://travis-ci.org/russross/blackfriday.svg?branch=v2 | |
| 333 [BuildV2URL]: https://travis-ci.org/russross/blackfriday | |
| 334 [PkgGoDevV2SVG]: https://pkg.go.dev/badge/github.com/russross/blackfriday/v2 | |
| 335 [PkgGoDevV2URL]: https://pkg.go.dev/github.com/russross/blackfriday/v2 |
