pkgs/markdown/lib/src/extension_set.dart

import 'block_syntaxes/alert_block_syntax.dart';
import 'block_syntaxes/block_syntax.dart';
import 'block_syntaxes/fenced_code_block_syntax.dart';
import 'block_syntaxes/footnote_def_syntax.dart';
import 'block_syntaxes/header_with_id_syntax.dart';
import 'block_syntaxes/ordered_list_with_checkbox_syntax.dart';
import 'block_syntaxes/setext_header_syntax.dart';
import 'block_syntaxes/setext_header_with_id_syntax.dart';
import 'block_syntaxes/table_syntax.dart';
import 'block_syntaxes/unordered_list_with_checkbox_syntax.dart';
import 'inline_syntaxes/autolink_extension_syntax.dart';
import 'inline_syntaxes/color_swatch_syntax.dart';
import 'inline_syntaxes/emoji_syntax.dart';
import 'inline_syntaxes/inline_html_syntax.dart';
import 'inline_syntaxes/inline_syntax.dart';
import 'inline_syntaxes/strikethrough_syntax.dart';

/// ExtensionSets provide a simple grouping mechanism for common Markdown
/// flavors.
///
/// For example, the [gitHubFlavored] set of syntax extensions allows users to
/// output HTML from their Markdown in a similar fashion to GitHub's parsing.
class ExtensionSet {
  /// The [ExtensionSet.none] extension set renders Markdown similar to
  /// [Markdown.pl].
  ///
  /// However, this set does not render _exactly_ the same as Markdown.pl;
  /// rather it is more-or-less the CommonMark standard of Markdown, without
  /// fenced code blocks, or inline HTML.
  ///
  /// [Markdown.pl]: http://daringfireball.net/projects/markdown/syntax
  static final ExtensionSet none = ExtensionSet(const [], const []);

  /// The [commonMark] extension set is close to compliance with [CommonMark].
  ///
  /// [CommonMark]: http://commonmark.org/
  static final ExtensionSet commonMark = ExtensionSet(
    List<BlockSyntax>.unmodifiable(<BlockSyntax>[
      const FencedCodeBlockSyntax(),
    ]),
    List<InlineSyntax>.unmodifiable(<InlineSyntax>[InlineHtmlSyntax()]),
  );

  /// The [gitHubWeb] extension set renders Markdown similarly to GitHub.
  ///
  /// This is different from the [gitHubFlavored] extension set in that GitHub
  /// actually renders HTML different from straight [GitHub flavored Markdown].
  ///
  /// (The only difference currently is that [gitHubWeb] renders headers with
  /// linkable IDs.)
  ///
  /// [GitHub flavored Markdown]: https://github.github.com/gfm/
  static final ExtensionSet gitHubWeb = ExtensionSet(
    List<BlockSyntax>.unmodifiable(<BlockSyntax>[
      const FencedCodeBlockSyntax(),
      const HeaderWithIdSyntax(),
      const SetextHeaderWithIdSyntax(),
      const TableSyntax(),
      const UnorderedListWithCheckboxSyntax(),
      const OrderedListWithCheckboxSyntax(),
      const FootnoteDefSyntax(),
      const AlertBlockSyntax(),
    ]),
    List<InlineSyntax>.unmodifiable(<InlineSyntax>[
      InlineHtmlSyntax(),
      StrikethroughSyntax(),
      EmojiSyntax(),
      ColorSwatchSyntax(),
      AutolinkExtensionSyntax(),
    ]),
  );

  /// The [gitHubFlavored] extension set is close to compliance with the
  /// [GitHub flavored Markdown spec](https://github.github.com/gfm/).
  static final ExtensionSet gitHubFlavored = ExtensionSet(
    List<BlockSyntax>.unmodifiable(<BlockSyntax>[
      const FencedCodeBlockSyntax(),
      const TableSyntax(),
      // Must precede the list syntaxes below: a lone `-` (or `=`) line
      // continuing a paragraph is a setext heading underline, not an empty
      // list item. See https://github.com/dart-lang/tools/issues/2108.
      const SetextHeaderSyntax(),
      const UnorderedListWithCheckboxSyntax(),
      const OrderedListWithCheckboxSyntax(),
      const FootnoteDefSyntax(),
    ]),
    List<InlineSyntax>.unmodifiable(<InlineSyntax>[
      InlineHtmlSyntax(),
      StrikethroughSyntax(),
      AutolinkExtensionSyntax(),
    ]),
  );

  final List<BlockSyntax> blockSyntaxes;
  final List<InlineSyntax> inlineSyntaxes;

  ExtensionSet(this.blockSyntaxes, this.inlineSyntaxes);
}