refractor/lang/markdown.js

Lightweight, robust, elegant virtual syntax highlighting using Prism

'use strict';

module.exports = markdown;
markdown.displayName = 'markdown';
markdown.aliases = [];
function markdown(Prism) {
  Prism.languages.markdown = Prism.languages.extend('markup', {});
  Prism.languages.insertBefore('markdown', 'prolog', {
    blockquote: {
      // > ...
      pattern: /^>(?:[\t ]*>)*/m,
      alias: 'punctuation'
    },
    code: [
      {
        // Prefixed by 4 spaces or 1 tab
        pattern: /^(?: {4}|\t).+/m,
        alias: 'keyword'
      },
      {
        // `code`
        // ``code``
        pattern: /``.+?``|`[^`\n]+`/,
        alias: 'keyword'
      }
    ],
    title: [
      {
        // title 1
        // =======
        // title 2
        // -------
        pattern: /\w+.*(?:\r?\n|\r)(?:==+|--+)/,
        alias: 'important',
        inside: {
          punctuation: /==+$|--+$/
        }
      },
      {
        // # title 1
        // ###### title 6
        pattern: /(^\s*)#+.+/m,
        lookbehind: true,
        alias: 'important',
        inside: {
          punctuation: /^#+|#+$/
        }
      }
    ],
    hr: {
      // ***
      // ---
      // * * *
      // -----------
      pattern: /(^\s*)([*-])(?:[\t ]*\2){2,}(?=\s*$)/m,
      lookbehind: true,
      alias: 'punctuation'
    },
    list: {
      // * item
      // + item
      // - item
      // 1. item
      pattern: /(^\s*)(?:[*+-]|\d+\.)(?=[\t ].)/m,
      lookbehind: true,
      alias: 'punctuation'
    },
    'url-reference': {
      // [id]: http://example.com "Optional title"
      // [id]: http://example.com 'Optional title'
      // [id]: http://example.com (Optional title)
      // [id]: <http://example.com> "Optional title"
      pattern: /!?\[[^\]]+\]:[\t ]+(?:\S+|<(?:\\.|[^>\\])+>)(?:[\t ]+(?:"(?:\\.|[^"\\])*"|'(?:\\.|[^'\\])*'|\((?:\\.|[^)\\])*\)))?/,
      inside: {
        variable: {
          pattern: /^(!?\[)[^\]]+/,
          lookbehind: true
        },
        string: /(?:"(?:\\.|[^"\\])*"|'(?:\\.|[^'\\])*'|\((?:\\.|[^)\\])*\))$/,
        punctuation: /^[\[\]!:]|[<>]/
      },
      alias: 'url'
    },
    bold: {
      // **strong**
      // __strong__
      // Allow only one line break
      pattern: /(^|[^\\])(\*\*|__)(?:(?:\r?\n|\r)(?!\r?\n|\r)|.)+?\2/,
      lookbehind: true,
      inside: {
        punctuation: /^\*\*|^__|\*\*$|__$/
      }
    },
    italic: {
      // *em*
      // _em_
      // Allow only one line break
      pattern: /(^|[^\\])([*_])(?:(?:\r?\n|\r)(?!\r?\n|\r)|.)+?\2/,
      lookbehind: true,
      inside: {
        punctuation: /^[*_]|[*_]$/
      }
    },
    url: {
      // [example](http://example.com "Optional title")
      // [example] [id]
      pattern: /!?\[[^\]]+\](?:\([^\s)]+(?:[\t ]+"(?:\\.|[^"\\])*")?\)| ?\[[^\]\n]*\])/,
      inside: {
        variable: {
          pattern: /(!?\[)[^\]]+(?=\]$)/,
          lookbehind: true
        },
        string: {
          pattern: /"(?:\\.|[^"\\])*"(?=\)$)/
        }
      }
    }
  });
  Prism.languages.markdown['bold'].inside['url'] = Prism.util.clone(
    Prism.languages.markdown['url']
  );
  Prism.languages.markdown['italic'].inside['url'] = Prism.util.clone(
    Prism.languages.markdown['url']
  );
  Prism.languages.markdown['bold'].inside['italic'] = Prism.util.clone(
    Prism.languages.markdown['italic']
  );
  Prism.languages.markdown['italic'].inside['bold'] = Prism.util.clone(
    Prism.languages.markdown['bold']
  );
}