jmptrader / markdown

CommonMark-compliant markdown parser and renderer in Go

markdown

opennota/markdown package provides CommonMark-compliant markdown parser and renderer, written in Go.

Installation

go get github.com/opennota/markdown

You can also go get mdtool, an example command-line tool:

go get github.com/opennota/mdtool

Standards support

Currently supported CommonMark spec: v0.20.

Extensions

Besides the features required by CommonMark, opennota/markdown supports:

• Tables (GFM)
• Strikethrough (GFM)
• Autoconverting plain-text URLs to links
• Typographic replacements (smart quotes and other)

Usage

md := markdown.New(markdown.XHTMLOutput(true), markdown.Nofollow(true))
fmt.Println(md.RenderToString([]byte("Header\n===\nText")))

Check out the source of mdtool for a more complete example.

The following options are currently supported:

Name	Type	Description	Default
HTML	bool	whether to enable raw HTML	false
Tables	bool	whether to enable GFM tables	true
Linkify	bool	whether to autoconvert plain-text URLs to links	true
Typographer	bool	whether to enable typographic replacements	true
Quotes	string	double + single quote replacement pairs for the typographer	“”‘’
MaxNesting	int	maximum nesting level	20
LangPrefix	string	CSS language prefix for fenced blocks	language-
Breaks	bool	whether to convert newlines inside paragraphs into <br>	false
Nofollow	bool	whether to add rel="nofollow" to links	false
XHTMLOutput	bool	whether to output XHTML instead of HTML	false

Benchmarks

Rendering spec/spec-0.20.txt on a Intel(R) Core(TM) i5-2400 CPU @ 3.10GHz

BenchmarkRenderSpecNoHTML         300     5751062 ns/op    2696668 B/op     7861 allocs/op
BenchmarkRenderSpec               100    15423729 ns/op    4659899 B/op    38725 allocs/op
BenchmarkRenderSpecBlackFriday    200     7531597 ns/op    2750346 B/op    37247 allocs/op

TODO

• Improve performance with the raw HTML option enabled
• Write an URL parser/encoder that would support decoding punycode and counting matching [( and )] in URLs

References / Thanks

opennota/markdown is a partial port of an awesome JavaScript markdown parser markdown-it, written by Alex Kocharin and Vitaly Puzrin.

See also

https://github.com/jgm/CommonMark — the reference CommonMark implementations in C and JavaScript, also contains the latest spec and an online demo.

http://talk.commonmark.org — the CommonMark forum, a good place to join together the efforts of the developers.