About

Markdown AST parser for mruby – built with md4c.

The library produces an AST that can then be rendered for the browser or other environments like the terminal but that is left up to the user to do from the AST alone.

The focus on the AST helps keep the core library simple, understandable, and maintainable. If you build your own renderer that uses the AST, consider opening a pull request with a link to your repository.

Quick Start

markdown = Markdown.new("# Hello **world**")
ast = markdown.ast

puts ast[:type]                  # => :document
puts ast[:children][0][:type]    # => :heading
puts ast[:children][0][:level]   # => 1

AST Shape

The root node is always:

{ type: :document, children: [...] }

Common node fields:

• :type for the symbolic node type
• :kind for the internal numeric node kind
• :children for nested nodes
• :text for text-node content

Example:

{
  kind: 7,
  type: :heading,
  level: 1,
  children: [
    {
      kind: 27,
      type: :text,
      text_kind: 0,
      text_type: :text,
      text: "Hello world"
    }
  ]
}

Tables, links, lists, emphasis, code, and other markdown structures are represented as nested hashes and arrays in the same style.

Flags

Pass parser flags as the optional second argument to Markdown.new:

flags = Markdown::TABLES | Markdown::STRIKETHROUGH
markdown = Markdown.new(text, flags)

Useful constants:

• Markdown::DEFAULT_FLAGS
• Markdown::TABLES
• Markdown::STRIKETHROUGH
• Markdown::UNDERLINE
• Markdown::COLLAPSE_WHITESPACE
• Markdown::NO_HTML_BLOCKS
• Markdown::NO_HTML_SPANS
• Markdown::TASK_LISTS
• Markdown::LATEX_MATH
• Markdown::WIKI_LINKS

Source Layout

• src/markdown.c defines the Markdown class and public API
• src/ast.c builds the Ruby AST from md4c callbacks
• src/md4c/ contains the bundled md4c sources

License

MIT. Bundled md4c is under its own MIT license.