reprism/src/languages/markdown.js

Modular Syntax highlighting for the web

export default {
  language: 'markdown',
  init: 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.languages.markdown.url
    Prism.languages.markdown.italic.inside.url =
      Prism.languages.markdown.url
    Prism.languages.markdown.bold.inside.italic =
      Prism.languages.markdown.italic
    Prism.languages.markdown.italic.inside.bold =
      Prism.languages.markdown.bold
  },
}