%a{annotate:rdoc:skip}
module RDoc
  # <!-- rdoc-file=lib/rdoc/markup.rb -->
  # RDoc::Markup parses plain text documents and attempts to decompose them into
  # their constituent parts.  Some of these parts are high-level: paragraphs,
  # chunks of verbatim text, list entries and the like.  Other parts happen at the
  # character level: a piece of bold text, a word in code font.  This markup is
  # similar in spirit to that used on WikiWiki webs, where folks create web pages
  # using a simple set of formatting rules.
  #
  # RDoc::Markup and other markup formats do no output formatting, this is handled
  # by the RDoc::Markup::Formatter subclasses.
  #
  # # Markup Formats
  #
  # `RDoc` supports these markup formats:
  #
  # *   `rdoc`: the `RDoc` markup format; see RDoc::MarkupReference.
  # *   `markdown`: The `markdown` markup format as described in the [Markdown
  #     Guide](https://www.markdownguide.org); see RDoc::Markdown.
  # *   `rd`: the `rd` markup format format; see RDoc::RD.
  # *   `tomdoc`: the TomDoc format as described in [TomDoc for
  #     Ruby](http://tomdoc.org); see RDoc::TomDoc.
  #
  # You can choose a markup format using the following methods:
  #
  # per project
  # :   If you build your documentation with rake use RDoc::Task#markup.
  #
  #     If you build your documentation by hand run:
  #
  #         rdoc --markup your_favorite_format --write-options
  #
  #     and commit `.rdoc_options` and ship it with your packaged gem.
  #
  # per file
  # :   At the top of the file use the `:markup:` directive to set the default
  #     format for the rest of the file.
  #
  # per comment
  # :   Use the `:markup:` directive at the top of a comment you want to write in
  #     a different format.
  #
  #
  # # RDoc::Markup
  #
  # RDoc::Markup is extensible at runtime: you can add new markup elements to be
  # recognized in the documents that RDoc::Markup parses.
  #
  # RDoc::Markup is intended to be the basis for a family of tools which share the
  # common requirement that simple, plain-text should be rendered in a variety of
  # different output formats and media.  It is envisaged that RDoc::Markup could
  # be the basis for formatting RDoc style comment blocks, Wiki entries, and
  # online FAQs.
  #
  # ## Synopsis
  #
  # This code converts `input_string` to HTML.  The conversion takes place in the
  # `convert` method, so you can use the same RDoc::Markup converter to convert
  # multiple input strings.
  #
  #     require 'rdoc'
  #
  #     h = RDoc::Markup::ToHtml.new(RDoc::Options.new)
  #
  #     puts h.convert(input_string)
  #
  # You can extend the RDoc::Markup parser to recognize new markup sequences, and
  # to add regexp handling. Here we make WikiWords significant to the parser, and
  # also make the sequences {word} and <no>text...</no> signify strike-through
  # text.  We then subclass the HTML output class to deal with these:
  #
  #     require 'rdoc'
  #
  #     class WikiHtml < RDoc::Markup::ToHtml
  #       def handle_regexp_WIKIWORD(target)
  #         "<font color=red>" + target.text + "</font>"
  #       end
  #     end
  #
  #     markup = RDoc::Markup.new
  #     markup.add_word_pair("{", "}", :STRIKE)
  #     markup.add_html("no", :STRIKE)
  #
  #     markup.add_regexp_handling(/\b([A-Z][a-z]+[A-Z]\w+)/, :WIKIWORD)
  #
  #     wh = WikiHtml.new RDoc::Options.new, markup
  #     wh.add_tag(:STRIKE, "<strike>", "</strike>")
  #
  #     puts "<body>#{wh.convert ARGF.read}</body>"
  #
  # ## Encoding
  #
  # Where Encoding support is available, RDoc will automatically convert all
  # documents to the same output encoding.  The output encoding can be set via
  # RDoc::Options#encoding and defaults to Encoding.default_external.
  #
  # # RDoc Markup Reference
  #
  # See RDoc::MarkupReference.
  #
  class Markup
    class Document
      include Enumerable[Document]

      def each: () { (Document) -> void } -> void
              | () -> Enumerator[Document, void]

      def file: () -> String?

      def accept: (untyped) -> String
    end

    class ToMarkdown
    end
  end
end
