function sourceDecorator()

in src/site/resources/js/prettify.js [782:891]
85 lines of code
11 McCabe index (conditional complexity)

  function sourceDecorator(options) {
    var shortcutStylePatterns = [], fallthroughStylePatterns = [];
    if (options['tripleQuotedStrings']) {
      // '''multi-line-string''', 'single-line-string', and double-quoted
      shortcutStylePatterns.push(
          [PR_STRING,  /^(?:\'\'\'(?:[^\'\\]|\\[\s\S]|\'{1,2}(?=[^\']))*(?:\'\'\'|$)|\"\"\"(?:[^\"\\]|\\[\s\S]|\"{1,2}(?=[^\"]))*(?:\"\"\"|$)|\'(?:[^\\\']|\\[\s\S])*(?:\'|$)|\"(?:[^\\\"]|\\[\s\S])*(?:\"|$))/,
           null, '\'"']);
    } else if (options['multiLineStrings']) {
      // 'multi-line-string', "multi-line-string"
      shortcutStylePatterns.push(
          [PR_STRING,  /^(?:\'(?:[^\\\']|\\[\s\S])*(?:\'|$)|\"(?:[^\\\"]|\\[\s\S])*(?:\"|$)|\`(?:[^\\\`]|\\[\s\S])*(?:\`|$))/,
           null, '\'"`']);
    } else {
      // 'single-line-string', "single-line-string"
      shortcutStylePatterns.push(
          [PR_STRING,
           /^(?:\'(?:[^\\\'\r\n]|\\.)*(?:\'|$)|\"(?:[^\\\"\r\n]|\\.)*(?:\"|$))/,
           null, '"\'']);
    }
    if (options['verbatimStrings']) {
      // verbatim-string-literal production from the C# grammar.  See issue 93.
      fallthroughStylePatterns.push(
          [PR_STRING, /^@\"(?:[^\"]|\"\")*(?:\"|$)/, null]);
    }
    var hc = options['hashComments'];
    if (hc) {
      if (options['cStyleComments']) {
        if (hc > 1) {  // multiline hash comments
          shortcutStylePatterns.push(
              [PR_COMMENT, /^#(?:##(?:[^#]|#(?!##))*(?:###|$)|.*)/, null, '#']);
        } else {
          // Stop C preprocessor declarations at an unclosed open comment
          shortcutStylePatterns.push(
              [PR_COMMENT, /^#(?:(?:define|elif|else|endif|error|ifdef|include|ifndef|line|pragma|undef|warning)\b|[^\r\n]*)/,
               null, '#']);
        }
        fallthroughStylePatterns.push(
            [PR_STRING,
             /^<(?:(?:(?:\.\.\/)*|\/?)(?:[\w-]+(?:\/[\w-]+)+)?[\w-]+\.h|[a-z]\w*)>/,
             null]);
      } else {
        shortcutStylePatterns.push([PR_COMMENT, /^#[^\r\n]*/, null, '#']);
      }
    }
    if (options['cStyleComments']) {
      fallthroughStylePatterns.push([PR_COMMENT, /^\/\/[^\r\n]*/, null]);
      fallthroughStylePatterns.push(
          [PR_COMMENT, /^\/\*[\s\S]*?(?:\*\/|$)/, null]);
    }
    if (options['regexLiterals']) {
      /**
       * @const
       */
      var REGEX_LITERAL = (
          // A regular expression literal starts with a slash that is
          // not followed by * or / so that it is not confused with
          // comments.
          '/(?=[^/*])'
          // and then contains any number of raw characters,
          + '(?:[^/\\x5B\\x5C]'
          // escape sequences (\x5C),
          +    '|\\x5C[\\s\\S]'
          // or non-nesting character sets (\x5B\x5D);
          +    '|\\x5B(?:[^\\x5C\\x5D]|\\x5C[\\s\\S])*(?:\\x5D|$))+'
          // finally closed by a /.
          + '/');
      fallthroughStylePatterns.push(
          ['lang-regex',
           new RegExp('^' + REGEXP_PRECEDER_PATTERN + '(' + REGEX_LITERAL + ')')
           ]);
    }

    var types = options['types'];
    if (types) {
      fallthroughStylePatterns.push([PR_TYPE, types]);
    }

    var keywords = ("" + options['keywords']).replace(/^ | $/g, '');
    if (keywords.length) {
      fallthroughStylePatterns.push(
          [PR_KEYWORD,
           new RegExp('^(?:' + keywords.replace(/[\s,]+/g, '|') + ')\\b'),
           null]);
    }

    shortcutStylePatterns.push([PR_PLAIN,       /^\s+/, null, ' \r\n\t\xA0']);
    fallthroughStylePatterns.push(
        // TODO(mikesamuel): recognize non-latin letters and numerals in idents
        [PR_LITERAL,     /^@[a-z_$][a-z_$@0-9]*/i, null],
        [PR_TYPE,        /^(?:[@_]?[A-Z]+[a-z][A-Za-z_$@0-9]*|\w+_t\b)/, null],
        [PR_PLAIN,       /^[a-z_$][a-z_$@0-9]*/i, null],
        [PR_LITERAL,
         new RegExp(
             '^(?:'
             // A hex number
             + '0x[a-f0-9]+'
             // or an octal or decimal number,
             + '|(?:\\d(?:_\\d+)*\\d*(?:\\.\\d*)?|\\.\\d\\+)'
             // possibly in scientific notation
             + '(?:e[+\\-]?\\d+)?'
             + ')'
             // with an optional modifier like UL for unsigned long
             + '[a-z]*', 'i'),
         null, '0123456789'],
        // Don't treat escaped quotes in bash as starting strings.  See issue 144.
        [PR_PLAIN,       /^\\[\s\S]?/, null],
        [PR_PUNCTUATION, /^.[^\s\w\.$@\'\"\`\/\#\\]*/, null]);

    return createSimpleLexer(shortcutStylePatterns, fallthroughStylePatterns);
  }