module.exports = function(hljs) {
  var KEYWORDS = {
    keyword:
      'actor addressof and as be break class compile_error compile_intrinsic' +
      'consume continue delegate digestof do else elseif embed end error' +
      'for fun if ifdef in interface is isnt lambda let match new not object' +
      'or primitive recover repeat return struct then trait try type until ' +
      'use var where while with xor',
    meta:
      'iso val tag trn box ref',
    literal:
      'this false true'
  };

  var TRIPLE_QUOTE_STRING_MODE = {
    className: 'string',
    begin: '"""', end: '"""',
    relevance: 10
  };

  var QUOTE_STRING_MODE = {
    className: 'string',
    begin: '"', end: '"',
    contains: [hljs.BACKSLASH_ESCAPE]
  };

  var SINGLE_QUOTE_CHAR_MODE = {
    className: 'string',
    begin: '\'', end: '\'',
    contains: [hljs.BACKSLASH_ESCAPE],
    relevance: 0
  };

  var TYPE_NAME = {
    className: 'type',
    begin: '\\b_?[A-Z][\\w]*',
    relevance: 0
  };

  var PRIMED_NAME = {
    begin: hljs.IDENT_RE + '\'', relevance: 0
  };

  var CLASS = {
    className: 'class',
    beginKeywords: 'class actor object primitive', end: '$',
    contains: [
      {
        className: 'keyword',
        begin: 'is'
      },
      TYPE_NAME,
      hljs.TITLE_MODE,
      hljs.C_LINE_COMMENT_MODE
    ]
  }

  var FUNCTION = {
    className: 'function',
    beginKeywords: 'new fun be', end: '=>',
    contains: [
      hljs.TITLE_MODE,
      {
        begin: /\(/, end: /\)/,
        contains: [
          TYPE_NAME,
          PRIMED_NAME,
          hljs.C_NUMBER_MODE,
          hljs.C_BLOCK_COMMENT_MODE
        ]
      },
      {
        begin: /:/, endsWithParent: true,
        contains: [TYPE_NAME]
      },
      hljs.C_LINE_COMMENT_MODE
    ]
  }

  return {
    keywords: KEYWORDS,
    contains: [
      CLASS,
      FUNCTION,
      TYPE_NAME,
      TRIPLE_QUOTE_STRING_MODE,
      QUOTE_STRING_MODE,
      SINGLE_QUOTE_CHAR_MODE,
      PRIMED_NAME,
      hljs.C_NUMBER_MODE,
      hljs.C_LINE_COMMENT_MODE,
      hljs.C_BLOCK_COMMENT_MODE
    ]
  };
};