if (! this.sh_languages) {
  this.sh_languages = {};
}
sh_languages['m4'] = [
  [
    [
      /dnl/g,
      'sh_keyword',
      1,
      1
    ],
    [
      /#/g,
      'sh_comment',
      7
    ],
    [
      /"/g,
      'sh_string',
      8
    ],
    [
      /\$[\d]+/g,
      'sh_variable',
      -1
    ]
  ],
  [
    [
      /$/g,
      null,
      -2
    ],
    [
      /[ \t]+/g,
      'sh_comment',
      -1
    ],
    [
      /(?:<?)[A-Za-z0-9_\.\/\-_~]+@[A-Za-z0-9_\.\/\-_~]+(?:>?)|(?:<?)[A-Za-z0-9_]+:\/\/[A-Za-z0-9_\.\/\-_~]+(?:>?)/g,
      'sh_url',
      -1
    ],
    [
      /<\?xml/g,
      'sh_preproc',
      2,
      1
    ],
    [
      /<!DOCTYPE/g,
      'sh_preproc',
      4,
      1
    ],
    [
      /<!--/g,
      'sh_comment',
      5
    ],
    [
      /<(?:\/)?[A-Za-z](?:[A-Za-z0-9_:.-]*)(?:\/)?>/g,
      'sh_keyword',
      -1
    ],
    [
      /<(?:\/)?[A-Za-z](?:[A-Za-z0-9_:.-]*)/g,
      'sh_keyword',
      6,
      1
    ],
    [
      /&(?:[A-Za-z0-9]+);/g,
      'sh_preproc',
      -1
    ],
    [
      /<(?:\/)?[A-Za-z][A-Za-z0-9]*(?:\/)?>/g,
      'sh_keyword',
      -1
    ],
    [
      /<(?:\/)?[A-Za-z][A-Za-z0-9]*/g,
      'sh_keyword',
      6,
      1
    ],
    [
      /@[A-Za-z]+/g,
      'sh_type',
      -1
    ],
    [
      /.+/g,
      'sh_comment',
      -1
    ]
  ],
  [
    [
      /\?>/g,
      'sh_preproc',
      -2
    ],
    [
      /([^=" \t>]+)([ \t]*)(=?)/g,
      ['sh_type', 'sh_normal', 'sh_symbol'],
      -1
    ],
    [
      /"/g,
      'sh_string',
      3
    ]
  ],
  [
    [
      /\\(?:\\|")/g,
      null,
      -1
    ],
    [
      /"/g,
      'sh_string',
      -2
    ]
  ],
  [
    [
      />/g,
      'sh_preproc',
      -2
    ],
    [
      /([^=" \t>]+)([ \t]*)(=?)/g,
      ['sh_type', 'sh_normal', 'sh_symbol'],
      -1
    ],
    [
      /"/g,
      'sh_string',
      3
    ]
  ],
  [
    [
      /-->/g,
      'sh_comment',
      -2
    ],
    [
      /<!--/g,
      'sh_comment',
      5
    ]
  ],
  [
    [
      /(?:\/)?>/g,
      'sh_keyword',
      -2
    ],
    [
      /([^=" \t>]+)([ \t]*)(=?)/g,
      ['sh_type', 'sh_normal', 'sh_symbol'],
      -1
    ],
    [
      /"/g,
      'sh_string',
      3
    ]
  ],
  [
    [
      /$/g,
      null,
      -2
    ]
  ],
  [
    [
      /$/g,
      null,
      -2
    ],
    [
      /\\(?:\\|")/g,
      null,
      -1
    ],
    [
      /"/g,
      'sh_string',
      -2
    ]
  ]
];