README

Blackfriday Build Status Godoc

Blackfriday is a Markdown processor implemented in Go. It is paranoid about its input (so you can safely feed it user-supplied data), it is fast, it supports common extensions (tables, smart punctuation substitutions, etc.), and it is safe for all utf-8 (unicode) input.

HTML output is currently supported, along with Smartypants extensions.

It started as a translation from C of Sundown.

Installation

Blackfriday is compatible with any modern Go release. With Go and git installed:

go get -u gopkg.in/russross/blackfriday.v2

will download, compile, and install the package into your $GOPATH directory hierarchy.

Versions

Currently maintained and recommended version of Blackfriday is v2. It's being developed on its own branch: https://github.com/russross/blackfriday/tree/v2 and the documentation is available at https://godoc.org/gopkg.in/russross/blackfriday.v2.

It is go get-able via gopkg.in at gopkg.in/russross/blackfriday.v2, but we highly recommend using package management tool like dep or Glide and make use of semantic versioning. With package management you should import github.com/russross/blackfriday and specify that you're using version 2.0.0.

Version 2 offers a number of improvements over v1:

  • Cleaned up API
  • A separate call to Parse, which produces an abstract syntax tree for the document
  • Latest bug fixes
  • Flexibility to easily add your own rendering extensions

Potential drawbacks:

  • Our benchmarks show v2 to be slightly slower than v1. Currently in the ballpark of around 15%.
  • API breakage. If you can't afford modifying your code to adhere to the new API and don't care too much about the new features, v2 is probably not for you.
  • Several bug fixes are trailing behind and still need to be forward-ported to v2. See issue #348 for tracking.

If you are still interested in the legacy v1, you can import it from github.com/russross/blackfriday. Documentation for the legacy v1 can be found here: https://godoc.org/github.com/russross/blackfriday

Known issue with dep

There is a known problem with using Blackfriday v1 transitively and dep. Currently dep prioritizes semver versions over anything else, and picks the latest one, plus it does not apply a [[constraint]] specifier to transitively pulled in packages. So if you're using something that uses Blackfriday v1, but that something does not use dep yet, you will get Blackfriday v2 pulled in and your first dependency will fail to build.

There are couple of fixes for it, documented here: https://github.com/golang/dep/blob/master/docs/FAQ.md#how-do-i-constrain-a-transitive-dependencys-version

Meanwhile, dep team is working on a more general solution to the constraints on transitive dependencies problem: https://github.com/golang/dep/issues/1124.

Usage

v1

For basic usage, it is as simple as getting your input into a byte slice and calling:

output := blackfriday.MarkdownBasic(input)

This renders it with no extensions enabled. To get a more useful feature set, use this instead:

output := blackfriday.MarkdownCommon(input)
v2

For the most sensible markdown processing, it is as simple as getting your input into a byte slice and calling:

output := blackfriday.Run(input)

Your input will be parsed and the output rendered with a set of most popular extensions enabled. If you want the most basic feature set, corresponding with the bare Markdown specification, use:

output := blackfriday.Run(input, blackfriday.WithNoExtensions())
Sanitize untrusted content

Blackfriday itself does nothing to protect against malicious content. If you are dealing with user-supplied markdown, we recommend running Blackfriday's output through HTML sanitizer such as Bluemonday.

Here's an example of simple usage of Blackfriday together with Bluemonday:

import (
    "github.com/microcosm-cc/bluemonday"
    "gopkg.in/russross/blackfriday.v2"
)

// ...
unsafe := blackfriday.Run(input)
html := bluemonday.UGCPolicy().SanitizeBytes(unsafe)
Custom options, v1

If you want to customize the set of options, first get a renderer (currently only the HTML output engine), then use it to call the more general Markdown function. For examples, see the implementations of MarkdownBasic and MarkdownCommon in markdown.go.

Custom options, v2

If you want to customize the set of options, use blackfriday.WithExtensions, blackfriday.WithRenderer and blackfriday.WithRefOverride.

blackfriday-tool

You can also check out blackfriday-tool for a more complete example of how to use it. Download and install it using:

go get github.com/russross/blackfriday-tool

This is a simple command-line tool that allows you to process a markdown file using a standalone program. You can also browse the source directly on github if you are just looking for some example code:

Note that if you have not already done so, installing blackfriday-tool will be sufficient to download and install blackfriday in addition to the tool itself. The tool binary will be installed in $GOPATH/bin. This is a statically-linked binary that can be copied to wherever you need it without worrying about dependencies and library versions.

Sanitized anchor names

Blackfriday includes an algorithm for creating sanitized anchor names corresponding to a given input text. This algorithm is used to create anchors for headings when EXTENSION_AUTO_HEADER_IDS is enabled. The algorithm has a specification, so that other packages can create compatible anchor names and links to those anchors.

The specification is located at https://godoc.org/github.com/russross/blackfriday#hdr-Sanitized_Anchor_Names.

SanitizedAnchorName exposes this functionality, and can be used to create compatible links to the anchor names generated by blackfriday. This algorithm is also implemented in a small standalone package at github.com/shurcooL/sanitized_anchor_name. It can be useful for clients that want a small package and don't need full functionality of blackfriday.

Features

All features of Sundown are supported, including:

  • Compatibility. The Markdown v1.0.3 test suite passes with the --tidy option. Without --tidy, the differences are mostly in whitespace and entity escaping, where blackfriday is more consistent and cleaner.

  • Common extensions, including table support, fenced code blocks, autolinks, strikethroughs, non-strict emphasis, etc.

  • Safety. Blackfriday is paranoid when parsing, making it safe to feed untrusted user input without fear of bad things happening. The test suite stress tests this and there are no known inputs that make it crash. If you find one, please let me know and send me the input that does it.

    NOTE: "safety" in this context means runtime safety only. In order to protect yourself against JavaScript injection in untrusted content, see this example.

  • Fast processing. It is fast enough to render on-demand in most web applications without having to cache the output.

  • Thread safety. You can run multiple parsers in different goroutines without ill effect. There is no dependence on global shared state.

  • Minimal dependencies. Blackfriday only depends on standard library packages in Go. The source code is pretty self-contained, so it is easy to add to any project, including Google App Engine projects.

  • Standards compliant. Output successfully validates using the W3C validation tool for HTML 4.01 and XHTML 1.0 Transitional.

Extensions

In addition to the standard markdown syntax, this package implements the following extensions:

  • Intra-word emphasis supression. The _ character is commonly used inside words when discussing code, so having markdown interpret it as an emphasis command is usually the wrong thing. Blackfriday lets you treat all emphasis markers as normal characters when they occur inside a word.

  • Tables. Tables can be created by drawing them in the input using a simple syntax:

    Name    | Age
    --------|------
    Bob     | 27
    Alice   | 23
    
  • Fenced code blocks. In addition to the normal 4-space indentation to mark code blocks, you can explicitly mark them and supply a language (to make syntax highlighting simple). Just mark it like this:

    ``` go
    func getTrue() bool {
        return true
    }
    ```
    

    You can use 3 or more backticks to mark the beginning of the block, and the same number to mark the end of the block.

    To preserve classes of fenced code blocks while using the bluemonday HTML sanitizer, use the following policy:

    p := bluemonday.UGCPolicy()
    p.AllowAttrs("class").Matching(regexp.MustCompile("^language-[a-zA-Z0-9]+$")).OnElements("code")
    html := p.SanitizeBytes(unsafe)
    
  • Definition lists. A simple definition list is made of a single-line term followed by a colon and the definition for that term.

    Cat
    : Fluffy animal everyone likes
        
    Internet
    : Vector of transmission for pictures of cats
    

    Terms must be separated from the previous definition by a blank line.

  • Footnotes. A marker in the text that will become a superscript number; a footnote definition that will be placed in a list of footnotes at the end of the document. A footnote looks like this:

    This is a footnote.[^1]
        
    [^1]: the footnote text.
    
  • Autolinking. Blackfriday can find URLs that have not been explicitly marked as links and turn them into links.

  • Strikethrough. Use two tildes (~~) to mark text that should be crossed out.

  • Hard line breaks. With this extension enabled (it is off by default in the MarkdownBasic and MarkdownCommon convenience functions), newlines in the input translate into line breaks in the output.

  • Smart quotes. Smartypants-style punctuation substitution is supported, turning normal double- and single-quote marks into curly quotes, etc.

  • LaTeX-style dash parsing is an additional option, where -- is translated into –, and --- is translated into —. This differs from most smartypants processors, which turn a single hyphen into an ndash and a double hyphen into an mdash.

  • Smart fractions, where anything that looks like a fraction is translated into suitable HTML (instead of just a few special cases like most smartypant processors). For example, 4/5 becomes <sup>4</sup>&frasl;<sub>5</sub>, which renders as 45.

Other renderers

Blackfriday is structured to allow alternative rendering engines. Here are a few of note:

  • github_flavored_markdown: provides a GitHub Flavored Markdown renderer with fenced code block highlighting, clickable heading anchor links.

    It's not customizable, and its goal is to produce HTML output equivalent to the GitHub Markdown API endpoint, except the rendering is performed locally.

  • markdownfmt: like gofmt, but for markdown.

  • LaTeX output: renders output as LaTeX.

  • bfchroma: provides convenience integration with the Chroma code highlighting library. bfchroma is only compatible with v2 of Blackfriday and provides a drop-in renderer ready to use with Blackfriday, as well as options and means for further customization.

TODO

  • More unit testing
  • Improve Unicode support. It does not understand all Unicode rules (about what constitutes a letter, a punctuation symbol, etc.), so it may fail to detect word boundaries correctly in some instances. It is safe on all UTF-8 input.

License

Blackfriday is distributed under the Simplified BSD License

Documentation

Overview

Package blackfriday is a Markdown processor.

It translates plain text with simple formatting rules into HTML or LaTeX.

Sanitized Anchor Names

Blackfriday includes an algorithm for creating sanitized anchor names corresponding to a given input text. This algorithm is used to create anchors for headings when EXTENSION_AUTO_HEADER_IDS is enabled. The algorithm is specified below, so that other packages can create compatible anchor names and links to those anchors.

The algorithm iterates over the input text, interpreted as UTF-8, one Unicode code point (rune) at a time. All runes that are letters (category L) or numbers (category N) are considered valid characters. They are mapped to lower case, and included in the output. All other runes are considered invalid characters. Invalid characters that preceed the first valid character, as well as invalid character that follow the last valid character are dropped completely. All other sequences of invalid characters between two valid characters are replaced with a single dash character '-'.

SanitizedAnchorName exposes this functionality, and can be used to create compatible links to the anchor names generated by blackfriday. This algorithm is also implemented in a small standalone package at github.com/shurcooL/sanitized_anchor_name. It can be useful for clients that want a small package and don't need full functionality of blackfriday.

Index

Constants

View Source
const (
	HTML_SKIP_HTML                 = 1 << iota // skip preformatted HTML blocks
	HTML_SKIP_STYLE                            // skip embedded <style> elements
	HTML_SKIP_IMAGES                           // skip embedded images
	HTML_SKIP_LINKS                            // skip all links
	HTML_SAFELINK                              // only link to trusted protocols
	HTML_NOFOLLOW_LINKS                        // only link with rel="nofollow"
	HTML_NOREFERRER_LINKS                      // only link with rel="noreferrer"
	HTML_HREF_TARGET_BLANK                     // add a blank target
	HTML_TOC                                   // generate a table of contents
	HTML_OMIT_CONTENTS                         // skip the main contents (for a standalone table of contents)
	HTML_COMPLETE_PAGE                         // generate a complete HTML page
	HTML_USE_XHTML                             // generate XHTML output instead of HTML
	HTML_USE_SMARTYPANTS                       // enable smart punctuation substitutions
	HTML_SMARTYPANTS_FRACTIONS                 // enable smart fractions (with HTML_USE_SMARTYPANTS)
	HTML_SMARTYPANTS_DASHES                    // enable smart dashes (with HTML_USE_SMARTYPANTS)
	HTML_SMARTYPANTS_LATEX_DASHES              // enable LaTeX-style dashes (with HTML_USE_SMARTYPANTS and HTML_SMARTYPANTS_DASHES)
	HTML_SMARTYPANTS_ANGLED_QUOTES             // enable angled double quotes (with HTML_USE_SMARTYPANTS) for double quotes rendering
	HTML_SMARTYPANTS_QUOTES_NBSP               // enable "French guillemets" (with HTML_USE_SMARTYPANTS)
	HTML_FOOTNOTE_RETURN_LINKS                 // generate a link at the end of a footnote to return to the source
)

    Html renderer configuration options.

    View Source
    const (
    	EXTENSION_NO_INTRA_EMPHASIS          = 1 << iota // ignore emphasis markers inside words
    	EXTENSION_TABLES                                 // render tables
    	EXTENSION_FENCED_CODE                            // render fenced code blocks
    	EXTENSION_AUTOLINK                               // detect embedded URLs that are not explicitly marked
    	EXTENSION_STRIKETHROUGH                          // strikethrough text using ~~test~~
    	EXTENSION_LAX_HTML_BLOCKS                        // loosen up HTML block parsing rules
    	EXTENSION_SPACE_HEADERS                          // be strict about prefix header rules
    	EXTENSION_HARD_LINE_BREAK                        // translate newlines into line breaks
    	EXTENSION_TAB_SIZE_EIGHT                         // expand tabs to eight spaces instead of four
    	EXTENSION_FOOTNOTES                              // Pandoc-style footnotes
    	EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK             // No need to insert an empty line to start a (code, quote, ordered list, unordered list) block
    	EXTENSION_HEADER_IDS                             // specify header IDs  with {#id}
    	EXTENSION_TITLEBLOCK                             // Titleblock ala pandoc
    	EXTENSION_AUTO_HEADER_IDS                        // Create the header ID from the text
    	EXTENSION_BACKSLASH_LINE_BREAK                   // translate trailing backslashes into line breaks
    	EXTENSION_DEFINITION_LISTS                       // render definition lists
    	EXTENSION_JOIN_LINES                             // delete newline and join lines
    
    )

      These are the supported markdown parsing extensions. OR these values together to select multiple extensions.

      View Source
      const (
      	LINK_TYPE_NOT_AUTOLINK = iota
      	LINK_TYPE_NORMAL
      	LINK_TYPE_EMAIL
      )

        These are the possible flag values for the link renderer. Only a single one of these values will be used; they are not ORed together. These are mostly of interest if you are writing a new output format.

        View Source
        const (
        	LIST_TYPE_ORDERED = 1 << iota
        	LIST_TYPE_DEFINITION
        	LIST_TYPE_TERM
        	LIST_ITEM_CONTAINS_BLOCK
        	LIST_ITEM_BEGINNING_OF_LIST
        	LIST_ITEM_END_OF_LIST
        )

          These are the possible flag values for the ListItem renderer. Multiple flag values may be ORed together. These are mostly of interest if you are writing a new output format.

          View Source
          const (
          	TABLE_ALIGNMENT_LEFT = 1 << iota
          	TABLE_ALIGNMENT_RIGHT
          	TABLE_ALIGNMENT_CENTER = (TABLE_ALIGNMENT_LEFT | TABLE_ALIGNMENT_RIGHT)
          )

            These are the possible flag values for the table cell renderer. Only a single one of these values will be used; they are not ORed together. These are mostly of interest if you are writing a new output format.

            View Source
            const (
            	TAB_SIZE_DEFAULT = 4
            	TAB_SIZE_EIGHT   = 8
            )

              The size of a tab stop.

              View Source
              const VERSION = "1.5"

              Variables

              This section is empty.

              Functions

              func Markdown

              func Markdown(input []byte, renderer Renderer, extensions int) []byte

                Markdown is the main rendering function. It parses and renders a block of markdown-encoded text. The supplied Renderer is used to format the output, and extensions dictates which non-standard extensions are enabled.

                To use the supplied Html or LaTeX renderers, see HtmlRenderer and LatexRenderer, respectively.

                func MarkdownBasic

                func MarkdownBasic(input []byte) []byte

                  MarkdownBasic is a convenience function for simple rendering. It processes markdown input with no extensions enabled.

                  func MarkdownCommon

                  func MarkdownCommon(input []byte) []byte

                    Call Markdown with most useful extensions enabled MarkdownCommon is a convenience function for simple rendering. It processes markdown input with common extensions enabled, including:

                    * Smartypants processing with smart fractions and LaTeX dashes

                    * Intra-word emphasis suppression

                    * Tables

                    * Fenced code blocks

                    * Autolinking

                    * Strikethrough support

                    * Strict header parsing

                    * Custom Header IDs

                    func MarkdownOptions

                    func MarkdownOptions(input []byte, renderer Renderer, opts Options) []byte

                      MarkdownOptions is just like Markdown but takes additional options through the Options struct.

                      func SanitizedAnchorName

                      func SanitizedAnchorName(text string) string

                        SanitizedAnchorName returns a sanitized anchor name for the given text.

                        It implements the algorithm specified in the package comment.

                        Types

                        type Html

                        type Html struct {
                        	// contains filtered or unexported fields
                        }

                          Html is a type that implements the Renderer interface for HTML output.

                          Do not create this directly, instead use the HtmlRenderer function.

                          func (options *Html) AutoLink(out *bytes.Buffer, link []byte, kind int)

                          func (*Html) BlockCode

                          func (options *Html) BlockCode(out *bytes.Buffer, text []byte, info string)

                          func (*Html) BlockHtml

                          func (options *Html) BlockHtml(out *bytes.Buffer, text []byte)

                          func (*Html) BlockQuote

                          func (options *Html) BlockQuote(out *bytes.Buffer, text []byte)

                          func (*Html) CodeSpan

                          func (options *Html) CodeSpan(out *bytes.Buffer, text []byte)

                          func (*Html) DocumentFooter

                          func (options *Html) DocumentFooter(out *bytes.Buffer)

                          func (*Html) DocumentHeader

                          func (options *Html) DocumentHeader(out *bytes.Buffer)

                          func (*Html) DoubleEmphasis

                          func (options *Html) DoubleEmphasis(out *bytes.Buffer, text []byte)

                          func (*Html) Emphasis

                          func (options *Html) Emphasis(out *bytes.Buffer, text []byte)

                          func (*Html) Entity

                          func (options *Html) Entity(out *bytes.Buffer, entity []byte)

                          func (*Html) FootnoteItem

                          func (options *Html) FootnoteItem(out *bytes.Buffer, name, text []byte, flags int)

                          func (*Html) FootnoteRef

                          func (options *Html) FootnoteRef(out *bytes.Buffer, ref []byte, id int)

                          func (*Html) Footnotes

                          func (options *Html) Footnotes(out *bytes.Buffer, text func() bool)

                          func (*Html) GetFlags

                          func (options *Html) GetFlags() int

                          func (*Html) HRule

                          func (options *Html) HRule(out *bytes.Buffer)

                          func (*Html) Header

                          func (options *Html) Header(out *bytes.Buffer, text func() bool, level int, id string)

                          func (*Html) Image

                          func (options *Html) Image(out *bytes.Buffer, link []byte, title []byte, alt []byte)

                          func (*Html) LineBreak

                          func (options *Html) LineBreak(out *bytes.Buffer)
                          func (options *Html) Link(out *bytes.Buffer, link []byte, title []byte, content []byte)

                          func (*Html) List

                          func (options *Html) List(out *bytes.Buffer, text func() bool, flags int)

                          func (*Html) ListItem

                          func (options *Html) ListItem(out *bytes.Buffer, text []byte, flags int)

                          func (*Html) NormalText

                          func (options *Html) NormalText(out *bytes.Buffer, text []byte)

                          func (*Html) Paragraph

                          func (options *Html) Paragraph(out *bytes.Buffer, text func() bool)

                          func (*Html) RawHtmlTag

                          func (options *Html) RawHtmlTag(out *bytes.Buffer, text []byte)

                          func (*Html) Smartypants

                          func (options *Html) Smartypants(out *bytes.Buffer, text []byte)

                          func (*Html) StrikeThrough

                          func (options *Html) StrikeThrough(out *bytes.Buffer, text []byte)

                          func (*Html) Table

                          func (options *Html) Table(out *bytes.Buffer, header []byte, body []byte, columnData []int)

                          func (*Html) TableCell

                          func (options *Html) TableCell(out *bytes.Buffer, text []byte, align int)

                          func (*Html) TableHeaderCell

                          func (options *Html) TableHeaderCell(out *bytes.Buffer, text []byte, align int)

                          func (*Html) TableRow

                          func (options *Html) TableRow(out *bytes.Buffer, text []byte)

                          func (*Html) TitleBlock

                          func (options *Html) TitleBlock(out *bytes.Buffer, text []byte)

                          func (*Html) TocFinalize

                          func (options *Html) TocFinalize()

                          func (*Html) TocHeader

                          func (options *Html) TocHeader(text []byte, level int)

                          func (*Html) TocHeaderWithAnchor

                          func (options *Html) TocHeaderWithAnchor(text []byte, level int, anchor string)

                          func (*Html) TripleEmphasis

                          func (options *Html) TripleEmphasis(out *bytes.Buffer, text []byte)

                          type HtmlRendererParameters

                          type HtmlRendererParameters struct {
                          	// Prepend this text to each relative URL.
                          	AbsolutePrefix string
                          	// Add this text to each footnote anchor, to ensure uniqueness.
                          	FootnoteAnchorPrefix string
                          	// Show this text inside the <a> tag for a footnote return link, if the
                          	// HTML_FOOTNOTE_RETURN_LINKS flag is enabled. If blank, the string
                          	// <sup>[return]</sup> is used.
                          	FootnoteReturnLinkContents string
                          	// If set, add this text to the front of each Header ID, to ensure
                          	// uniqueness.
                          	HeaderIDPrefix string
                          	// If set, add this text to the back of each Header ID, to ensure uniqueness.
                          	HeaderIDSuffix string
                          }

                          type Latex

                          type Latex struct {
                          }

                            Latex is a type that implements the Renderer interface for LaTeX output.

                            Do not create this directly, instead use the LatexRenderer function.

                            func (options *Latex) AutoLink(out *bytes.Buffer, link []byte, kind int)

                            func (*Latex) BlockCode

                            func (options *Latex) BlockCode(out *bytes.Buffer, text []byte, info string)

                              render code chunks using verbatim, or listings if we have a language

                              func (*Latex) BlockHtml

                              func (options *Latex) BlockHtml(out *bytes.Buffer, text []byte)

                              func (*Latex) BlockQuote

                              func (options *Latex) BlockQuote(out *bytes.Buffer, text []byte)

                              func (*Latex) CodeSpan

                              func (options *Latex) CodeSpan(out *bytes.Buffer, text []byte)

                              func (*Latex) DocumentFooter

                              func (options *Latex) DocumentFooter(out *bytes.Buffer)

                              func (*Latex) DocumentHeader

                              func (options *Latex) DocumentHeader(out *bytes.Buffer)

                                header and footer

                                func (*Latex) DoubleEmphasis

                                func (options *Latex) DoubleEmphasis(out *bytes.Buffer, text []byte)

                                func (*Latex) Emphasis

                                func (options *Latex) Emphasis(out *bytes.Buffer, text []byte)

                                func (*Latex) Entity

                                func (options *Latex) Entity(out *bytes.Buffer, entity []byte)

                                func (*Latex) FootnoteItem

                                func (options *Latex) FootnoteItem(out *bytes.Buffer, name, text []byte, flags int)

                                func (*Latex) FootnoteRef

                                func (options *Latex) FootnoteRef(out *bytes.Buffer, ref []byte, id int)

                                  TODO: this

                                  func (*Latex) Footnotes

                                  func (options *Latex) Footnotes(out *bytes.Buffer, text func() bool)

                                    TODO: this

                                    func (*Latex) GetFlags

                                    func (options *Latex) GetFlags() int

                                    func (*Latex) HRule

                                    func (options *Latex) HRule(out *bytes.Buffer)

                                    func (*Latex) Header

                                    func (options *Latex) Header(out *bytes.Buffer, text func() bool, level int, id string)

                                    func (*Latex) Image

                                    func (options *Latex) Image(out *bytes.Buffer, link []byte, title []byte, alt []byte)

                                    func (*Latex) LineBreak

                                    func (options *Latex) LineBreak(out *bytes.Buffer)
                                    func (options *Latex) Link(out *bytes.Buffer, link []byte, title []byte, content []byte)

                                    func (*Latex) List

                                    func (options *Latex) List(out *bytes.Buffer, text func() bool, flags int)

                                    func (*Latex) ListItem

                                    func (options *Latex) ListItem(out *bytes.Buffer, text []byte, flags int)

                                    func (*Latex) NormalText

                                    func (options *Latex) NormalText(out *bytes.Buffer, text []byte)

                                    func (*Latex) Paragraph

                                    func (options *Latex) Paragraph(out *bytes.Buffer, text func() bool)

                                    func (*Latex) RawHtmlTag

                                    func (options *Latex) RawHtmlTag(out *bytes.Buffer, tag []byte)

                                    func (*Latex) StrikeThrough

                                    func (options *Latex) StrikeThrough(out *bytes.Buffer, text []byte)

                                    func (*Latex) Table

                                    func (options *Latex) Table(out *bytes.Buffer, header []byte, body []byte, columnData []int)

                                    func (*Latex) TableCell

                                    func (options *Latex) TableCell(out *bytes.Buffer, text []byte, align int)

                                    func (*Latex) TableHeaderCell

                                    func (options *Latex) TableHeaderCell(out *bytes.Buffer, text []byte, align int)

                                    func (*Latex) TableRow

                                    func (options *Latex) TableRow(out *bytes.Buffer, text []byte)

                                    func (*Latex) TitleBlock

                                    func (options *Latex) TitleBlock(out *bytes.Buffer, text []byte)

                                    func (*Latex) TripleEmphasis

                                    func (options *Latex) TripleEmphasis(out *bytes.Buffer, text []byte)

                                    type Options

                                    type Options struct {
                                    	// Extensions is a flag set of bit-wise ORed extension bits. See the
                                    	// EXTENSION_* flags defined in this package.
                                    	Extensions int
                                    
                                    	// ReferenceOverride is an optional function callback that is called every
                                    	// time a reference is resolved.
                                    	//
                                    	// In Markdown, the link reference syntax can be made to resolve a link to
                                    	// a reference instead of an inline URL, in one of the following ways:
                                    	//
                                    	//  * [link text][refid]
                                    	//  * [refid][]
                                    	//
                                    	// Usually, the refid is defined at the bottom of the Markdown document. If
                                    	// this override function is provided, the refid is passed to the override
                                    	// function first, before consulting the defined refids at the bottom. If
                                    	// the override function indicates an override did not occur, the refids at
                                    	// the bottom will be used to fill in the link details.
                                    	ReferenceOverride ReferenceOverrideFunc
                                    }

                                      Options represents configurable overrides and callbacks (in addition to the extension flag set) for configuring a Markdown parse.

                                      type Reference

                                      type Reference struct {
                                      	// Link is usually the URL the reference points to.
                                      	Link string
                                      	// Title is the alternate text describing the link in more detail.
                                      	Title string
                                      	// Text is the optional text to override the ref with if the syntax used was
                                      	// [refid][]
                                      	Text string
                                      }

                                        Reference represents the details of a link. See the documentation in Options for more details on use-case.

                                        type ReferenceOverrideFunc

                                        type ReferenceOverrideFunc func(reference string) (ref *Reference, overridden bool)

                                          ReferenceOverrideFunc is expected to be called with a reference string and return either a valid Reference type that the reference string maps to or nil. If overridden is false, the default reference logic will be executed. See the documentation in Options for more details on use-case.

                                          type Renderer

                                          type Renderer interface {
                                          	// block-level callbacks
                                          	BlockCode(out *bytes.Buffer, text []byte, infoString string)
                                          	BlockQuote(out *bytes.Buffer, text []byte)
                                          	BlockHtml(out *bytes.Buffer, text []byte)
                                          	Header(out *bytes.Buffer, text func() bool, level int, id string)
                                          	HRule(out *bytes.Buffer)
                                          	List(out *bytes.Buffer, text func() bool, flags int)
                                          	ListItem(out *bytes.Buffer, text []byte, flags int)
                                          	Paragraph(out *bytes.Buffer, text func() bool)
                                          	Table(out *bytes.Buffer, header []byte, body []byte, columnData []int)
                                          	TableRow(out *bytes.Buffer, text []byte)
                                          	TableHeaderCell(out *bytes.Buffer, text []byte, flags int)
                                          	TableCell(out *bytes.Buffer, text []byte, flags int)
                                          	Footnotes(out *bytes.Buffer, text func() bool)
                                          	FootnoteItem(out *bytes.Buffer, name, text []byte, flags int)
                                          	TitleBlock(out *bytes.Buffer, text []byte)
                                          
                                          	// Span-level callbacks
                                          	AutoLink(out *bytes.Buffer, link []byte, kind int)
                                          	CodeSpan(out *bytes.Buffer, text []byte)
                                          	DoubleEmphasis(out *bytes.Buffer, text []byte)
                                          	Emphasis(out *bytes.Buffer, text []byte)
                                          	Image(out *bytes.Buffer, link []byte, title []byte, alt []byte)
                                          	LineBreak(out *bytes.Buffer)
                                          	Link(out *bytes.Buffer, link []byte, title []byte, content []byte)
                                          	RawHtmlTag(out *bytes.Buffer, tag []byte)
                                          	TripleEmphasis(out *bytes.Buffer, text []byte)
                                          	StrikeThrough(out *bytes.Buffer, text []byte)
                                          	FootnoteRef(out *bytes.Buffer, ref []byte, id int)
                                          
                                          	// Low-level callbacks
                                          	Entity(out *bytes.Buffer, entity []byte)
                                          	NormalText(out *bytes.Buffer, text []byte)
                                          
                                          	// Header and footer
                                          	DocumentHeader(out *bytes.Buffer)
                                          	DocumentFooter(out *bytes.Buffer)
                                          
                                          	GetFlags() int
                                          }

                                            Renderer is the rendering interface. This is mostly of interest if you are implementing a new rendering format.

                                            When a byte slice is provided, it contains the (rendered) contents of the element.

                                            When a callback is provided instead, it will write the contents of the respective element directly to the output buffer and return true on success. If the callback returns false, the rendering function should reset the output buffer as though it had never been called.

                                            Currently Html and Latex implementations are provided

                                            func HtmlRenderer

                                            func HtmlRenderer(flags int, title string, css string) Renderer

                                              HtmlRenderer creates and configures an Html object, which satisfies the Renderer interface.

                                              flags is a set of HTML_* options ORed together. title is the title of the document, and css is a URL for the document's stylesheet. title and css are only used when HTML_COMPLETE_PAGE is selected.

                                              func HtmlRendererWithParameters

                                              func HtmlRendererWithParameters(flags int, title string,
                                              	css string, renderParameters HtmlRendererParameters) Renderer

                                              func LatexRenderer

                                              func LatexRenderer(flags int) Renderer

                                                LatexRenderer creates and configures a Latex object, which satisfies the Renderer interface.

                                                flags is a set of LATEX_* options ORed together (currently no such options are defined).