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 |
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date | Sun, 23 Jul 2023 13:18:53 +0000 |
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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 |