prettify.js

// Copyright (C) 2006 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.


/**
 * @fileoverview
 * some functions for browser-side pretty printing of code contained in html.
 *
 * <p>
 * For a fairly comprehensive set of languages see the
 * <a href="http://google-code-prettify.googlecode.com/svn/trunk/README.html#langs">README</a>
 * file that came with this source.  At a minimum, the lexer should work on a
 * number of languages including C and friends, Java, Python, Bash, SQL, HTML,
 * XML, CSS, Javascript, and Makefiles.  It works passably on Ruby, PHP and Awk
 * and a subset of Perl, but, because of commenting conventions, doesn't work on
 * Smalltalk, Lisp-like, or CAML-like languages without an explicit lang class.
 * <p>
 * Usage: <ol>
 * <li> include this source file in an html page via
 *   {@code <script type="text/javascript" src="/path/to/prettify.js"></script>}
 * <li> define style rules.  See the example page for examples.
 * <li> mark the {@code <pre>} and {@code <code>} tags in your source with
 *    {@code class=prettyprint.}
 *    You can also use the (html deprecated) {@code <xmp>} tag, but the pretty
 *    printer needs to do more substantial DOM manipulations to support that, so
 *    some css styles may not be preserved.
 * </ol>
 * That's it.  I wanted to keep the API as simple as possible, so there's no
 * need to specify which language the code is in, but if you wish, you can add
 * another class to the {@code <pre>} or {@code <code>} element to specify the
 * language, as in {@code <pre class="prettyprint lang-java">}.  Any class that
 * starts with "lang-" followed by a file extension, specifies the file type.
 * See the "lang-*.js" files in this directory for code that implements
 * per-language file handlers.
 * <p>
 * Change log:<br>
 * cbeust, 2006/08/22
 * <blockquote>
 *   Java annotations (start with "@") are now captured as literals ("lit")
 * </blockquote>
 * @requires console
 */

// JSLint declarations
/*global console, document, navigator, setTimeout, window */

/**
 * Split {@code prettyPrint} into multiple timeouts so as not to interfere with
 * UI events.
 * If set to {@code false}, {@code prettyPrint()} is synchronous.
 */
window['PR_SHOULD_USE_CONTINUATION'] = true;

/** the number of characters between tab columns */
window['PR_TAB_WIDTH'] = 8;

/** Contains functions for creating and registering new language handlers.
  * @type {Object}
  */
window['PR']

/** Pretty print a chunk of code.
  *
  * @param {string} sourceCodeHtml code as html
  * @return {string} code as html, but prettier
  */
  = window['prettyPrintOne']
/** Find all the {@code <pre>} and {@code <code>} tags in the DOM with
  * {@code class=prettyprint} and prettify them.
  * @param {Function?} opt_whenDone if specified, called when the last entry
  *     has been finished.
  */
  = window['prettyPrint'] = void 0;


(function () {
  // Keyword lists for various languages.
  var FLOW_CONTROL_KEYWORDS =
      "break continue do else for if return while ";
  var C_KEYWORDS = FLOW_CONTROL_KEYWORDS + "auto case char const default " +
      "double enum extern float goto int long register short signed sizeof " +
      "static struct switch typedef union unsigned void volatile ";
  var COMMON_KEYWORDS = C_KEYWORDS + "catch class delete false import " +
      "new operator private protected public this throw true try typeof ";
  var CPP_KEYWORDS = COMMON_KEYWORDS + "alignof align_union asm axiom bool " +
      "concept concept_map const_cast constexpr decltype " +
      "dynamic_cast explicit export friend inline late_check " +
      "mutable namespace nullptr reinterpret_cast static_assert static_cast " +
      "template typeid typename using virtual wchar_t where ";
  var JAVA_KEYWORDS = COMMON_KEYWORDS +
      "abstract boolean byte extends final finally implements import " +
      "instanceof null native package strictfp super synchronized throws " +
      "transient ";
  var CSHARP_KEYWORDS = JAVA_KEYWORDS +
      "as base by checked decimal delegate descending dynamic event " +
      "fixed foreach from group implicit in interface internal into is lock " +
      "object out override orderby params partial readonly ref sbyte sealed " +
      "stackalloc string select uint ulong unchecked unsafe ushort var ";
  var COFFEE_KEYWORDS = "all and by catch class else extends false finally " +
      "for if in is isnt loop new no not null of off on or return super then " +
      "true try unless until when while yes ";
  var JSCRIPT_KEYWORDS = COMMON_KEYWORDS +
      "debugger eval export function get null set undefined var with " +
      "Infinity NaN ";
  var PERL_KEYWORDS = "caller delete die do dump elsif eval exit foreach for " +
      "goto if import last local my next no our print package redo require " +
      "sub undef unless until use wantarray while BEGIN END ";
  var PYTHON_KEYWORDS = FLOW_CONTROL_KEYWORDS + "and as assert class def del " +
      "elif except exec finally from global system git config import in is lambda " +
      "nonlocal not or pass print raise try with yield " +
      "False True None ";
  var RUBY_KEYWORDS = FLOW_CONTROL_KEYWORDS + " alias and begin case class def" +
      " defined elsif end ensure false in module next nil not or redo rescue " +
      "retry self super then true undef unless until when yield BEGIN END ";
  var SH_KEYWORDS = FLOW_CONTROL_KEYWORDS + "case done elif esac eval fi " +
      "function in local set then until ";

  var GIT_KEYWORDS = FLOW_CONTROL_KEYWORDS + "git push config commit merge branch system status add branch";

  var ALL_KEYWORDS = (
      CPP_KEYWORDS + CSHARP_KEYWORDS + JSCRIPT_KEYWORDS + PERL_KEYWORDS +
      PYTHON_KEYWORDS + RUBY_KEYWORDS + SH_KEYWORDS + GIT_KEYWORDS);

  // token style names.  correspond to css classes
  /** token style for a string literal */
  var PR_STRING = 'str';
  /** token style for a keyword */
  var PR_KEYWORD = 'kwd';
  /** token style for a comment */
  var PR_COMMENT = 'com';
  /** token style for a type */
  var PR_TYPE = 'typ';
  /** token style for a literal value.  e.g. 1, null, true. */
  var PR_LITERAL = 'lit';
  /** token style for a punctuation string. */
  var PR_PUNCTUATION = 'pun';
  /** token style for a punctuation string. */
  var PR_PLAIN = 'pln';

  /** token style for an sgml tag. */
  var PR_TAG = 'tag';
  /** token style for a markup declaration such as a DOCTYPE. */
  var PR_DECLARATION = 'dec';
  /** token style for embedded source. */
  var PR_SOURCE = 'src';
  /** token style for an sgml attribute name. */
  var PR_ATTRIB_NAME = 'atn';
  /** token style for an sgml attribute value. */
  var PR_ATTRIB_VALUE = 'atv';

  /**
   * A class that indicates a section of markup that is not code, e.g. to allow
   * embedding of line numbers within code listings.
   */
  var PR_NOCODE = 'nocode';

  /** A set of tokens that can precede a regular expression literal in
    * javascript.
    * http://www.mozilla.org/js/language/js20/rationale/syntax.html has the full
    * list, but I've removed ones that might be problematic when seen in
    * languages that don't support regular expression literals.
    *
    * <p>Specifically, I've removed any keywords that can't precede a regexp
    * literal in a syntactically legal javascript program, and I've removed the
    * "in" keyword since it's not a keyword in many languages, and might be used
    * as a count of inches.
    *
    * <p>The link a above does not accurately describe EcmaScript rules since
    * it fails to distinguish between (a=++/b/i) and (a++/b/i) but it works
    * very well in practice.
    *
    * @private
    */
  var REGEXP_PRECEDER_PATTERN = function () {
      var preceders = [
          "!", "!=", "!==", "#", "%", "%=", "&", "&&", "&&=",
          "&=", "(", "*", "*=", /* "+", */ "+=", ",", /* "-", */ "-=",
          "->", /*".", "..", "...", handled below */ "/", "/=", ":", "::", ";",
          "<", "<<", "<<=", "<=", "=", "==", "===", ">",
          ">=", ">>", ">>=", ">>>", ">>>=", "?", "@", "[",
          "^", "^=", "^^", "^^=", "{", "|", "|=", "||",
          "||=", "~" /* handles =~ and !~ */,
          "break", "case", "continue", "delete",
          "do", "else", "finally", "instanceof",
          "return", "throw", "try", "typeof"
          ];
      var pattern = '(?:^^|[+-]';
      for (var i = 0; i < preceders.length; ++i) {
        pattern += '|' + preceders[i].replace(/([^=<>:&a-z])/g, '\\$1');
      }
      pattern += ')\\s*';  // matches at end, and matches empty string
      return pattern;
      // CAVEAT: this does not properly handle the case where a regular
      // expression immediately follows another since a regular expression may
      // have flags for case-sensitivity and the like.  Having regexp tokens
      // adjacent is not valid in any language I'm aware of, so I'm punting.
      // TODO: maybe style special characters inside a regexp as punctuation.
    }();

  
  /**
   * Given a group of {@link RegExp}s, returns a {@code RegExp} that globally
   * matches the union of the sets of strings matched by the input RegExp.
   * Since it matches globally, if the input strings have a start-of-input
   * anchor (/^.../), it is ignored for the purposes of unioning.
   * @param {Array.<RegExp>} regexs non multiline, non-global regexs.
   * @return {RegExp} a global regex.
   */
  function combinePrefixPatterns(regexs) {
    var capturedGroupIndex = 0;
  
    var needToFoldCase = false;
    var ignoreCase = false;
    for (var i = 0, n = regexs.length; i < n; ++i) {
      var regex = regexs[i];
      if (regex.ignoreCase) {
        ignoreCase = true;
      } else if (/[a-z]/i.test(regex.source.replace(
                     /\\u[0-9a-f]{4}|\\x[0-9a-f]{2}|\\[^ux]/gi, ''))) {
        needToFoldCase = true;
        ignoreCase = false;
        break;
      }
    }
  
    function decodeEscape(charsetPart) {
      if (charsetPart.charAt(0) !== '\\') { return charsetPart.charCodeAt(0); }
      switch (charsetPart.charAt(1)) {
        case 'b': return 8;
        case 't': return 9;
        case 'n': return 0xa;
        case 'v': return 0xb;
        case 'f': return 0xc;
        case 'r': return 0xd;
        case 'u': case 'x':
          return parseInt(charsetPart.substring(2), 16)
              || charsetPart.charCodeAt(1);
        case '0': case '1': case '2': case '3': case '4':
        case '5': case '6': case '7':
          return parseInt(charsetPart.substring(1), 8);
        default: return charsetPart.charCodeAt(1);
      }
    }
  
    function encodeEscape(charCode) {
      if (charCode < 0x20) {
        return (charCode < 0x10 ? '\\x0' : '\\x') + charCode.toString(16);
      }
      var ch = String.fromCharCode(charCode);
      if (ch === '\\' || ch === '-' || ch === '[' || ch === ']') {
        ch = '\\' + ch;
      }
      return ch;
    }
  
    function caseFoldCharset(charSet) {
      var charsetParts = charSet.substring(1, charSet.length - 1).match(
          new RegExp(
              '\\\\u[0-9A-Fa-f]{4}'
              + '|\\\\x[0-9A-Fa-f]{2}'
              + '|\\\\[0-3][0-7]{0,2}'
              + '|\\\\[0-7]{1,2}'
              + '|\\\\[\\s\\S]'
              + '|-'
              + '|[^-\\\\]',
              'g'));
      var groups = [];
      var ranges = [];
      var inverse = charsetParts[0] === '^';
      for (var i = inverse ? 1 : 0, n = charsetParts.length; i < n; ++i) {
        var p = charsetParts[i];
        switch (p) {
          case '\\B': case '\\b':
          case '\\D': case '\\d':
          case '\\S': case '\\s':
          case '\\W': case '\\w':
            groups.push(p);
            continue;
        }
        var start = decodeEscape(p);
        var end;
        if (i + 2 < n && '-' === charsetParts[i + 1]) {
          end = decodeEscape(charsetParts[i + 2]);
          i += 2;
        } else {
          end = start;
        }
        ranges.push([start, end]);
        // If the range might intersect letters, then expand it.
        if (!(end < 65 || start > 122)) {
          if (!(end < 65 || start > 90)) {
            ranges.push([Math.max(65, start) | 32, Math.min(end, 90) | 32]);
          }
          if (!(end < 97 || start > 122)) {
            ranges.push([Math.max(97, start) & ~32, Math.min(end, 122) & ~32]);
          }
        }
      }
  
      // [[1, 10], [3, 4], [8, 12], [14, 14], [16, 16], [17, 17]]
      // -> [[1, 12], [14, 14], [16, 17]]
      ranges.sort(function (a, b) { return (a[0] - b[0]) || (b[1]  - a[1]); });
      var consolidatedRanges = [];
      var lastRange = [NaN, NaN];
      for (var i = 0; i < ranges.length; ++i) {
        var range = ranges[i];
        if (range[0] <= lastRange[1] + 1) {
          lastRange[1] = Math.max(lastRange[1], range[1]);
        } else {
          consolidatedRanges.push(lastRange = range);
        }
      }
  
      var out = ['['];
      if (inverse) { out.push('^'); }
      out.push.apply(out, groups);
      for (var i = 0; i < consolidatedRanges.length; ++i) {
        var range = consolidatedRanges[i];
        out.push(encodeEscape(range[0]));
        if (range[1] > range[0]) {
          if (range[1] + 1 > range[0]) { out.push('-'); }
          out.push(encodeEscape(range[1]));
        }
      }
      out.push(']');
      return out.join('');
    }
  
    function allowAnywhereFoldCaseAndRenumberGroups(regex) {
      // Split into character sets, escape sequences, punctuation strings
      // like ('(', '(?:', ')', '^'), and runs of characters that do not
      // include any of the above.
      var parts = regex.source.match(
          new RegExp(
              '(?:'
              + '\\[(?:[^\\x5C\\x5D]|\\\\[\\s\\S])*\\]'  // a character set
              + '|\\\\u[A-Fa-f0-9]{4}'  // a unicode escape
              + '|\\\\x[A-Fa-f0-9]{2}'  // a hex escape
              + '|\\\\[0-9]+'  // a back-reference or octal escape
              + '|\\\\[^ux0-9]'  // other escape sequence
              + '|\\(\\?[:!=]'  // start of a non-capturing group
              + '|[\\(\\)\\^]'  // start/emd of a group, or line start
              + '|[^\\x5B\\x5C\\(\\)\\^]+'  // run of other characters
              + ')',
              'g'));
      var n = parts.length;
  
      // Maps captured group numbers to the number they will occupy in
      // the output or to -1 if that has not been determined, or to
      // undefined if they need not be capturing in the output.
      var capturedGroups = [];
  
      // Walk over and identify back references to build the capturedGroups
      // mapping.
      for (var i = 0, groupIndex = 0; i < n; ++i) {
        var p = parts[i];
        if (p === '(') {
          // groups are 1-indexed, so max group index is count of '('
          ++groupIndex;
        } else if ('\\' === p.charAt(0)) {
          var decimalValue = +p.substring(1);
          if (decimalValue && decimalValue <= groupIndex) {
            capturedGroups[decimalValue] = -1;
          }
        }
      }
  
      // Renumber groups and reduce capturing groups to non-capturing groups
      // where possible.
      for (var i = 1; i < capturedGroups.length; ++i) {
        if (-1 === capturedGroups[i]) {
          capturedGroups[i] = ++capturedGroupIndex;
        }
      }
      for (var i = 0, groupIndex = 0; i < n; ++i) {
        var p = parts[i];
        if (p === '(') {
          ++groupIndex;
          if (capturedGroups[groupIndex] === undefined) {
            parts[i] = '(?:';
          }
        } else if ('\\' === p.charAt(0)) {
          var decimalValue = +p.substring(1);
          if (decimalValue && decimalValue <= groupIndex) {
            parts[i] = '\\' + capturedGroups[groupIndex];
          }
        }
      }
  
      // Remove any prefix anchors so that the output will match anywhere.
      // ^^ really does mean an anchored match though.
      for (var i = 0, groupIndex = 0; i < n; ++i) {
        if ('^' === parts[i] && '^' !== parts[i + 1]) { parts[i] = ''; }
      }
  
      // Expand letters to groups to handle mixing of case-sensitive and
      // case-insensitive patterns if necessary.
      if (regex.ignoreCase && needToFoldCase) {
        for (var i = 0; i < n; ++i) {
          var p = parts[i];
          var ch0 = p.charAt(0);
          if (p.length >= 2 && ch0 === '[') {
            parts[i] = caseFoldCharset(p);
          } else if (ch0 !== '\\') {
            // TODO: handle letters in numeric escapes.
            parts[i] = p.replace(
                /[a-zA-Z]/g,
                function (ch) {
                  var cc = ch.charCodeAt(0);
                  return '[' + String.fromCharCode(cc & ~32, cc | 32) + ']';
                });
          }
        }
      }
  
      return parts.join('');
    }
  
    var rewritten = [];
    for (var i = 0, n = regexs.length; i < n; ++i) {
      var regex = regexs[i];
      if (regex.global || regex.multiline) { throw new Error('' + regex); }
      rewritten.push(
          '(?:' + allowAnywhereFoldCaseAndRenumberGroups(regex) + ')');
    }
  
    return new RegExp(rewritten.join('|'), ignoreCase ? 'gi' : 'g');
  }


  /**
   * Split markup into a string of source code and an array mapping ranges in
   * that string to the text nodes in which they appear.
   *
   * <p>
   * The HTML DOM structure:</p>
   * <pre>
   * (Element   "p"
   *   (Element "b"
   *     (Text  "print "))       ; #1
   *   (Text    "'Hello '")      ; #2
   *   (Element "br")            ; #3
   *   (Text    "  + 'World';")) ; #4
   * </pre>
   * <p>
   * corresponds to the HTML
   * {@code <p><b>print </b>'Hello '<br>  + 'World';</p>}.</p>
   *
   * <p>
   * It will produce the output:</p>
   * <pre>
   * {
   *   source: "print 'Hello '\n  + 'World';",
   *   //                 1         2
   *   //       012345678901234 5678901234567
   *   spans: [0, #1, 6, #2, 14, #3, 15, #4]
   * }
   * </pre>
   * <p>
   * where #1 is a reference to the {@code "print "} text node above, and so
   * on for the other text nodes.
   * </p>
   *
   * <p>
   * The {@code} spans array is an array of pairs.  Even elements are the start
   * indices of substrings, and odd elements are the text nodes (or BR elements)
   * that contain the text for those substrings.
   * Substrings continue until the next index or the end of the source.
   * </p>
   *
   * @param {Node} node an HTML DOM subtree containing source-code.
   * @return {Object} source code and the text nodes in which they occur.
   */
  function extractSourceSpans(node) {
    var nocode = /(?:^|\s)nocode(?:\s|$)/;
  
    var chunks = [];
    var length = 0;
    var spans = [];
    var k = 0;
  
    var whitespace;
    if (node.currentStyle) {
      whitespace = node.currentStyle.whiteSpace;
    } else if (window.getComputedStyle) {
      whitespace = document.defaultView.getComputedStyle(node, null)
          .getPropertyValue('white-space');
    }
    var isPreformatted = whitespace && 'pre' === whitespace.substring(0, 3);
  
    function walk(node) {
      switch (node.nodeType) {
        case 1:  // Element
          if (nocode.test(node.className)) { return; }
          for (var child = node.firstChild; child; child = child.nextSibling) {
            walk(child);
          }
          var nodeName = node.nodeName;
          if ('BR' === nodeName || 'LI' === nodeName) {
            chunks[k] = '\n';
            spans[k << 1] = length++;
            spans[(k++ << 1) | 1] = node;
          }
          break;
        case 3: case 4:  // Text
          var text = node.nodeValue;
          if (text.length) {
            if (!isPreformatted) {
              text = text.replace(/[ \t\r\n]+/g, ' ');
            } else {
              text = text.replace(/\r\n?/g, '\n');  // Normalize newlines.
            }
            // TODO: handle tabs here?
            chunks[k] = text;
            spans[k << 1] = length;
            length += text.length;
            spans[(k++ << 1) | 1] = node;
          }
          break;
      }
    }
  
    walk(node);
  
    return {
      source: chunks.join('').replace(/\n$/, ''),
      spans: spans
    };
  }


  /**
   * Apply the given language handler to sourceCode and add the resulting
   * decorations to out.
   * @param {number} basePos the index of sourceCode within the chunk of source
   *    whose decorations are already present on out.
   */
  function appendDecorations(basePos, sourceCode, langHandler, out) {
    if (!sourceCode) { return; }
    var job = {
      source: sourceCode,
      basePos: basePos
    };
    langHandler(job);
    out.push.apply(out, job.decorations);
  }

  /** Given triples of [style, pattern, context] returns a lexing function,
    * The lexing function interprets the patterns to find token boundaries and
    * returns a decoration list of the form
    * [index_0, style_0, index_1, style_1, ..., index_n, style_n]
    * where index_n is an index into the sourceCode, and style_n is a style
    * constant like PR_PLAIN.  index_n-1 <= index_n, and style_n-1 applies to
    * all characters in sourceCode[index_n-1:index_n].
    *
    * The stylePatterns is a list whose elements have the form
    * [style : string, pattern : RegExp, DEPRECATED, shortcut : string].
    *
    * Style is a style constant like PR_PLAIN, or can be a string of the
    * form 'lang-FOO', where FOO is a language extension describing the
    * language of the portion of the token in $1 after pattern executes.
    * E.g., if style is 'lang-lisp', and group 1 contains the text
    * '(hello (world))', then that portion of the token will be passed to the
    * registered lisp handler for formatting.
    * The text before and after group 1 will be restyled using this decorator
    * so decorators should take care that this doesn't result in infinite
    * recursion.  For example, the HTML lexer rule for SCRIPT elements looks
    * something like ['lang-js', /<[s]cript>(.+?)<\/script>/].  This may match
    * '<script>foo()<\/script>', which would cause the current decorator to
    * be called with '<script>' which would not match the same rule since
    * group 1 must not be empty, so it would be instead styled as PR_TAG by
    * the generic tag rule.  The handler registered for the 'js' extension would
    * then be called with 'foo()', and finally, the current decorator would
    * be called with '<\/script>' which would not match the original rule and
    * so the generic tag rule would identify it as a tag.
    *
    * Pattern must only match prefixes, and if it matches a prefix, then that
    * match is considered a token with the same style.
    *
    * Context is applied to the last non-whitespace, non-comment token
    * recognized.
    *
    * Shortcut is an optional string of characters, any of which, if the first
    * character, gurantee that this pattern and only this pattern matches.
    *
    * @param {Array} shortcutStylePatterns patterns that always start with
    *   a known character.  Must have a shortcut string.
    * @param {Array} fallthroughStylePatterns patterns that will be tried in
    *   order if the shortcut ones fail.  May have shortcuts.
    *
    * @return {function (Object)} a
    *   function that takes source code and returns a list of decorations.
    */
  function createSimpleLexer(shortcutStylePatterns, fallthroughStylePatterns) {
    var shortcuts = {};
    var tokenizer;
    (function () {
      var allPatterns = shortcutStylePatterns.concat(fallthroughStylePatterns);
      var allRegexs = [];
      var regexKeys = {};
      for (var i = 0, n = allPatterns.length; i < n; ++i) {
        var patternParts = allPatterns[i];
        var shortcutChars = patternParts[3];
        if (shortcutChars) {
          for (var c = shortcutChars.length; --c >= 0;) {
            shortcuts[shortcutChars.charAt(c)] = patternParts;
          }
        }
        var regex = patternParts[1];
        var k = '' + regex;
        if (!regexKeys.hasOwnProperty(k)) {
          allRegexs.push(regex);
          regexKeys[k] = null;
        }
      }
      allRegexs.push(/[\0-\uffff]/);
      tokenizer = combinePrefixPatterns(allRegexs);
    })();

    var nPatterns = fallthroughStylePatterns.length;
    var notWs = /\S/;

    /**
     * Lexes job.source and produces an output array job.decorations of style
     * classes preceded by the position at which they start in job.source in
     * order.
     *
     * @param {Object} job an object like {@code
     *    source: {string} sourceText plain text,
     *    basePos: {int} position of job.source in the larger chunk of
     *        sourceCode.
     * }
     */
    var decorate = function (job) {
      var sourceCode = job.source, basePos = job.basePos;
      /** Even entries are positions in source in ascending order.  Odd enties
        * are style markers (e.g., PR_COMMENT) that run from that position until
        * the end.
        * @type {Array.<number|string>}
        */
      var decorations = [basePos, PR_PLAIN];
      var pos = 0;  // index into sourceCode
      var tokens = sourceCode.match(tokenizer) || [];
      var styleCache = {};

      for (var ti = 0, nTokens = tokens.length; ti < nTokens; ++ti) {
        var token = tokens[ti];
        var style = styleCache[token];
        var match = void 0;

        var isEmbedded;
        if (typeof style === 'string') {
          isEmbedded = false;
        } else {
          var patternParts = shortcuts[token.charAt(0)];
          if (patternParts) {
            match = token.match(patternParts[1]);
            style = patternParts[0];
          } else {
            for (var i = 0; i < nPatterns; ++i) {
              patternParts = fallthroughStylePatterns[i];
              match = token.match(patternParts[1]);
              if (match) {
                style = patternParts[0];
                break;
              }
            }

            if (!match) {  // make sure that we make progress
              style = PR_PLAIN;
            }
          }

          isEmbedded = style.length >= 5 && 'lang-' === style.substring(0, 5);
          if (isEmbedded && !(match && typeof match[1] === 'string')) {
            isEmbedded = false;
            style = PR_SOURCE;
          }

          if (!isEmbedded) { styleCache[token] = style; }
        }

        var tokenStart = pos;
        pos += token.length;

        if (!isEmbedded) {
          decorations.push(basePos + tokenStart, style);
        } else {  // Treat group 1 as an embedded block of source code.
          var embeddedSource = match[1];
          var embeddedSourceStart = token.indexOf(embeddedSource);
          var embeddedSourceEnd = embeddedSourceStart + embeddedSource.length;
          if (match[2]) {
            // If embeddedSource can be blank, then it would match at the
            // beginning which would cause us to infinitely recurse on the
            // entire token, so we catch the right context in match[2].
            embeddedSourceEnd = token.length - match[2].length;
            embeddedSourceStart = embeddedSourceEnd - embeddedSource.length;
          }
          var lang = style.substring(5);
          // Decorate the left of the embedded source
          appendDecorations(
              basePos + tokenStart,
              token.substring(0, embeddedSourceStart),
              decorate, decorations);
          // Decorate the embedded source
          appendDecorations(
              basePos + tokenStart + embeddedSourceStart,
              embeddedSource,
              langHandlerForExtension(lang, embeddedSource),
              decorations);
          // Decorate the right of the embedded section
          appendDecorations(
              basePos + tokenStart + embeddedSourceEnd,
              token.substring(embeddedSourceEnd),
              decorate, decorations);
        }
      }
      job.decorations = decorations;
    };
    return decorate;
  }

  /** returns a function that produces a list of decorations from source text.
    *
    * This code treats ", ', and ` as string delimiters, and \ as a string
    * escape.  It does not recognize perl's qq() style strings.
    * It has no special handling for double delimiter escapes as in basic, or
    * the tripled delimiters used in python, but should work on those regardless
    * although in those cases a single string literal may be broken up into
    * multiple adjacent string literals.
    *
    * It recognizes C, C++, and shell style comments.
    *
    * @param {Object} options a set of optional parameters.
    * @return {function (Object)} a function that examines the source code
    *     in the input job and builds the decoration list.
    */
  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']) {
      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 keywords = options['keywords'].replace(/^\s+|\s+$/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_$@0-9]*/, null],
        [PR_PLAIN,       /^[a-z_$][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);
  }

  var decorateSource = sourceDecorator({
        'keywords': ALL_KEYWORDS,
        'hashComments': true,
        'cStyleComments': true,
        'multiLineStrings': true,
        'regexLiterals': true
      });

  /**
   * Given a DOM subtree, wraps it in a list, and puts each line into its own
   * list item.
   *
   * @param {Node} node modified in place.  Its content is pulled into an
   *     HTMLOListElement, and each line is moved into a separate list item.
   *     This requires cloning elements, so the input might not have unique
   *     IDs after numbering.
   */
  function numberLines(node, opt_startLineNum) {
    var nocode = /(?:^|\s)nocode(?:\s|$)/;
    var lineBreak = /\r\n?|\n/;
  
    var document = node.ownerDocument;
  
    var whitespace;
    if (node.currentStyle) {
      whitespace = node.currentStyle.whiteSpace;
    } else if (window.getComputedStyle) {
      whitespace = document.defaultView.getComputedStyle(node, null)
          .getPropertyValue('white-space');
    }
    // If it's preformatted, then we need to split lines on line breaks
    // in addition to <BR>s.
    var isPreformatted = whitespace && 'pre' === whitespace.substring(0, 3);
  
    var li = document.createElement('LI');
    while (node.firstChild) {
      li.appendChild(node.firstChild);
    }
    // An array of lines.  We split below, so this is initialized to one
    // un-split line.
    var listItems = [li];
  
    function walk(node) {
      switch (node.nodeType) {
        case 1:  // Element
          if (nocode.test(node.className)) { break; }
          if ('BR' === node.nodeName) {
            breakAfter(node);
            // Discard the <BR> since it is now flush against a </LI>.
            if (node.parentNode) {
              node.parentNode.removeChild(node);
            }
          } else {
            for (var child = node.firstChild; child; child = child.nextSibling) {
              walk(child);
            }
          }
          break;
        case 3: case 4:  // Text
          if (isPreformatted) {
            var text = node.nodeValue;
            var match = text.match(lineBreak);
            if (match) {
              var firstLine = text.substring(0, match.index);
              node.nodeValue = firstLine;
              var tail = text.substring(match.index + match[0].length);
              if (tail) {
                var parent = node.parentNode;
                parent.insertBefore(
                    document.createTextNode(tail), node.nextSibling);
              }
              breakAfter(node);
              if (!firstLine) {
                // Don't leave blank text nodes in the DOM.
                node.parentNode.removeChild(node);
              }
            }
          }
          break;
      }
    }
  
    // Split a line after the given node.
    function breakAfter(lineEndNode) {
      // If there's nothing to the right, then we can skip ending the line
      // here, and move root-wards since splitting just before an end-tag
      // would require us to create a bunch of empty copies.
      while (!lineEndNode.nextSibling) {
        lineEndNode = lineEndNode.parentNode;
        if (!lineEndNode) { return; }
      }
  
      function breakLeftOf(limit, copy) {
        // Clone shallowly if this node needs to be on both sides of the break.
        var rightSide = copy ? limit.cloneNode(false) : limit;
        var parent = limit.parentNode;
        if (parent) {
          // We clone the parent chain.
          // This helps us resurrect important styling elements that cross lines.
          // E.g. in <i>Foo<br>Bar</i>
          // should be rewritten to <li><i>Foo</i></li><li><i>Bar</i></li>.
          var parentClone = breakLeftOf(parent, 1);
          // Move the clone and everything to the right of the original
          // onto the cloned parent.
          var next = limit.nextSibling;
          parentClone.appendChild(rightSide);
          for (var sibling = next; sibling; sibling = next) {
            next = sibling.nextSibling;
            parentClone.appendChild(sibling);
          }
        }
        return rightSide;
      }
  
      var copiedListItem = breakLeftOf(lineEndNode.nextSibling, 0);
  
      // Walk the parent chain until we reach an unattached LI.
      for (var parent;
           // Check nodeType since IE invents document fragments.
           (parent = copiedListItem.parentNode) && parent.nodeType === 1;) {
        copiedListItem = parent;
      }
      // Put it on the list of lines for later processing.
      listItems.push(copiedListItem);
    }
  
    // Split lines while there are lines left to split.
    for (var i = 0;  // Number of lines that have been split so far.
         i < listItems.length;  // length updated by breakAfter calls.
         ++i) {
      walk(listItems[i]);
    }
  
    // Make sure numeric indices show correctly.
    if (opt_startLineNum === (opt_startLineNum|0)) {
      listItems[0].setAttribute('value', opt_startLineNum);
    }
  
    var ol = document.createElement('OL');
    ol.className = 'linenums';
    var offset = Math.max(0, ((opt_startLineNum - 1 /* zero index */)) | 0) || 0;
    for (var i = 0, n = listItems.length; i < n; ++i) {
      li = listItems[i];
      // Stick a class on the LIs so that stylesheets can
      // color odd/even rows, or any other row pattern that
      // is co-prime with 10.
      li.className = 'L' + ((i + offset) % 10);
      if (!li.firstChild) {
        li.appendChild(document.createTextNode('\xA0'));
      }
      ol.appendChild(li);
    }
  
    node.appendChild(ol);
  }

  /**
   * Breaks {@code job.source} around style boundaries in {@code job.decorations}
   * and modifies {@code job.sourceNode} in place.
   * @param {Object} job like <pre>{
   *    source: {string} source as plain text,
   *    spans: {Array.<number|Node>} alternating span start indices into source
   *       and the text node or element (e.g. {@code <BR>}) corresponding to that
   *       span.
   *    decorations: {Array.<number|string} an array of style classes preceded
   *       by the position at which they start in job.source in order
   * }</pre>
   * @private
   */
  function recombineTagsAndDecorations(job) {
    var isIE = /\bMSIE\b/.test(navigator.userAgent);
    var newlineRe = /\n/g;
  
    var source = job.source;
    var sourceLength = source.length;
    // Index into source after the last code-unit recombined.
    var sourceIndex = 0;
  
    var spans = job.spans;
    var nSpans = spans.length;
    // Index into spans after the last span which ends at or before sourceIndex.
    var spanIndex = 0;
  
    var decorations = job.decorations;
    var nDecorations = decorations.length;
    // Index into decorations after the last decoration which ends at or before sourceIndex.
    var decorationIndex = 0;
  
    // Simplify decorations.
    var decPos = 0;
    for (var i = 0; i < nDecorations;) {
      // Skip over any zero-length decorations.
      var startPos = decorations[i];
      var start = i;
      while (start + 2 < nDecorations && decorations[start + 2] === startPos) {
        start += 2;
      }
      // Conflate all adjacent decorations that use the same style.
      var startDec = decorations[start + 1];
      var end = start + 2;
      while (end + 2 <= nDecorations
             && (decorations[end + 1] === startDec
                 || decorations[end] === decorations[end + 2])) {
        end += 2;
      }
      decorations[decPos++] = startPos;
      decorations[decPos++] = startDec;
      i = end;
    }
  
    // Strip any zero-length decoration at the end.
    if (decPos && decorations[decPos - 2] === sourceLength) { decPos -= 2; }
    nDecorations = decorations.length = decPos;
  
    var decoration = null;
    while (spanIndex < nSpans) {
      var spanStart = spans[spanIndex];
      var spanEnd = spans[spanIndex + 2] || sourceLength;
  
      var decStart = decorations[decorationIndex];
      var decEnd = decorations[decorationIndex + 2] || sourceLength;
  
      var end = Math.min(spanEnd, decEnd);
  
      var textNode = spans[spanIndex + 1];
      if (textNode.nodeType !== 1) {  // Don't muck with <BR>s or <LI>s
        var styledText = source.substring(sourceIndex, end);
        // This may seem bizarre, and it is.  Emitting LF on IE causes the
        // code to display with spaces instead of line breaks.
        // Emitting Windows standard issue linebreaks (CRLF) causes a blank
        // space to appear at the beginning of every line but the first.
        // Emitting an old Mac OS 9 line separator makes everything spiffy.
        if (isIE) { styledText = styledText.replace(newlineRe, '\r'); }
        textNode.nodeValue = styledText;
        var document = textNode.ownerDocument;
        var span = document.createElement('SPAN');
        span.className = decorations[decorationIndex + 1];
        var parentNode = textNode.parentNode;
        parentNode.replaceChild(span, textNode);
        span.appendChild(textNode);
        if (sourceIndex < spanEnd) {  // Split off a text node.
          spans[spanIndex + 1] = textNode
              // TODO: Possibly optimize by using '' if there's no flicker.
              = document.createTextNode(source.substring(end, spanEnd));
          parentNode.insertBefore(textNode, span.nextSibling);
        }
      }
  
      sourceIndex = end;
  
      if (sourceIndex >= spanEnd) {
        spanIndex += 2;
      }
      if (sourceIndex >= decEnd) {
        decorationIndex += 2;
      }
    }
  }


  /** Maps language-specific file extensions to handlers. */
  var langHandlerRegistry = {};
  /** Register a language handler for the given file extensions.
    * @param {function (Object)} handler a function from source code to a list
    *      of decorations.  Takes a single argument job which describes the
    *      state of the computation.   The single parameter has the form
    *      {@code {
    *        source: {string} as plain text.
    *        decorations: {Array.<number|string>} an array of style classes
    *                     preceded by the position at which they start in
    *                     job.source in order.
    *                     The language handler should assigned this field.
    *        basePos: {int} the position of source in the larger source chunk.
    *                 All positions in the output decorations array are relative
    *                 to the larger source chunk.
    *      } }
    * @param {Array.<string>} fileExtensions
    */
  function registerLangHandler(handler, fileExtensions) {
    for (var i = fileExtensions.length; --i >= 0;) {
      var ext = fileExtensions[i];
      if (!langHandlerRegistry.hasOwnProperty(ext)) {
        langHandlerRegistry[ext] = handler;
      } else if ('console' in window) {
        console['warn']('cannot override language handler %s', ext);
      }
    }
  }
  function langHandlerForExtension(extension, source) {
    if (!(extension && langHandlerRegistry.hasOwnProperty(extension))) {
      // Treat it as markup if the first non whitespace character is a < and
      // the last non-whitespace character is a >.
      extension = /^\s*</.test(source)
          ? 'default-markup'
          : 'default-code';
    }
    return langHandlerRegistry[extension];
  }
  registerLangHandler(decorateSource, ['default-code']);
  registerLangHandler(
      createSimpleLexer(
          [],
          [
           [PR_PLAIN,       /^[^<?]+/],
           [PR_DECLARATION, /^<!\w[^>]*(?:>|$)/],
           [PR_COMMENT,     /^<\!--[\s\S]*?(?:-\->|$)/],
           // Unescaped content in an unknown language
           ['lang-',        /^<\?([\s\S]+?)(?:\?>|$)/],
           ['lang-',        /^<%([\s\S]+?)(?:%>|$)/],
           [PR_PUNCTUATION, /^(?:<[%?]|[%?]>)/],
           ['lang-',        /^<xmp\b[^>]*>([\s\S]+?)<\/xmp\b[^>]*>/i],
           // Unescaped content in javascript.  (Or possibly vbscript).
           ['lang-js',      /^<script\b[^>]*>([\s\S]*?)(<\/script\b[^>]*>)/i],
           // Contains unescaped stylesheet content
           ['lang-css',     /^<style\b[^>]*>([\s\S]*?)(<\/style\b[^>]*>)/i],
           ['lang-in.tag',  /^(<\/?[a-z][^<>]*>)/i]
          ]),
      ['default-markup', 'htm', 'html', 'mxml', 'xhtml', 'xml', 'xsl']);
  registerLangHandler(
      createSimpleLexer(
          [
           [PR_PLAIN,        /^[\s]+/, null, ' \t\r\n'],
           [PR_ATTRIB_VALUE, /^(?:\"[^\"]*\"?|\'[^\']*\'?)/, null, '\"\'']
           ],
          [
           [PR_TAG,          /^^<\/?[a-z](?:[\w.:-]*\w)?|\/?>$/i],
           [PR_ATTRIB_NAME,  /^(?!style[\s=]|on)[a-z](?:[\w:-]*\w)?/i],
           ['lang-uq.val',   /^=\s*([^>\'\"\s]*(?:[^>\'\"\s\/]|\/(?=\s)))/],
           [PR_PUNCTUATION,  /^[=<>\/]+/],
           ['lang-js',       /^on\w+\s*=\s*\"([^\"]+)\"/i],
           ['lang-js',       /^on\w+\s*=\s*\'([^\']+)\'/i],
           ['lang-js',       /^on\w+\s*=\s*([^\"\'>\s]+)/i],
           ['lang-css',      /^style\s*=\s*\"([^\"]+)\"/i],
           ['lang-css',      /^style\s*=\s*\'([^\']+)\'/i],
           ['lang-css',      /^style\s*=\s*([^\"\'>\s]+)/i]
           ]),
      ['in.tag']);
  registerLangHandler(
      createSimpleLexer([], [[PR_ATTRIB_VALUE, /^[\s\S]+/]]), ['uq.val']);
  registerLangHandler(sourceDecorator({
          'keywords': CPP_KEYWORDS,
          'hashComments': true,
          'cStyleComments': true
        }), ['c', 'cc', 'cpp', 'cxx', 'cyc', 'm']);
  registerLangHandler(sourceDecorator({
          'keywords': 'null true false'
        }), ['json']);
  registerLangHandler(sourceDecorator({
          'keywords': CSHARP_KEYWORDS,
          'hashComments': true,
          'cStyleComments': true,
          'verbatimStrings': true
        }), ['cs']);
  registerLangHandler(sourceDecorator({
          'keywords': JAVA_KEYWORDS,
          'cStyleComments': true
        }), ['java']);
  registerLangHandler(sourceDecorator({
          'keywords': SH_KEYWORDS,
          'hashComments': true,
          'multiLineStrings': true
        }), ['bsh', 'csh', 'sh']);
  registerLangHandler(sourceDecorator({
          'keywords': PYTHON_KEYWORDS,
          'hashComments': true,
          'multiLineStrings': true,
          'tripleQuotedStrings': true
        }), ['cv', 'py']);
  registerLangHandler(sourceDecorator({
          'keywords': PERL_KEYWORDS,
          'hashComments': true,
          'multiLineStrings': true,
          'regexLiterals': true
        }), ['perl', 'pl', 'pm']);
  registerLangHandler(sourceDecorator({
          'keywords': RUBY_KEYWORDS,
          'hashComments': true,
          'multiLineStrings': true,
          'regexLiterals': true
        }), ['rb']);
  registerLangHandler(sourceDecorator({
          'keywords': JSCRIPT_KEYWORDS,
          'cStyleComments': true,
          'regexLiterals': true
        }), ['js']);
  registerLangHandler(sourceDecorator({
          'keywords': COFFEE_KEYWORDS,
          'hashComments': 3,  // ### style block comments
          'cStyleComments': true,
          'multilineStrings': true,
          'tripleQuotedStrings': true,
          'regexLiterals': true
        }), ['coffee']);
  registerLangHandler(createSimpleLexer([], [[PR_STRING, /^[\s\S]+/]]), ['regex']);

  function applyDecorator(job) {
    var opt_langExtension = job.langExtension;

    try {
      // Extract tags, and convert the source code to plain text.
      var sourceAndSpans = extractSourceSpans(job.sourceNode);
      /** Plain text. @type {string} */
      var source = sourceAndSpans.source;
      job.source = source;
      job.spans = sourceAndSpans.spans;
      job.basePos = 0;

      // Apply the appropriate language handler
      langHandlerForExtension(opt_langExtension, source)(job);

      // Integrate the decorations and tags back into the source code,
      // modifying the sourceNode in place.
      recombineTagsAndDecorations(job);
    } catch (e) {
      if ('console' in window) {
        console['log'](e && e['stack'] ? e['stack'] : e);
      }
    }
  }

  /**
   * @param sourceCodeHtml {string} The HTML to pretty print.
   * @param opt_langExtension {string} The language name to use.
   *     Typically, a filename extension like 'cpp' or 'java'.
   * @param opt_numberLines {number|boolean} True to number lines,
   *     or the 1-indexed number of the first line in sourceCodeHtml.
   */
  function prettyPrintOne(sourceCodeHtml, opt_langExtension, opt_numberLines) {
    var container = document.createElement('PRE');
    // This could cause images to load and onload listeners to fire.
    // E.g. <img onerror="alert(1337)" src="nosuchimage.png">.
    // We assume that the inner HTML is from a trusted source.
    container.innerHTML = sourceCodeHtml;
    if (opt_numberLines) {
      numberLines(container, opt_numberLines);
    }

    var job = {
      langExtension: opt_langExtension,
      numberLines: opt_numberLines,
      sourceNode: container
    };
    applyDecorator(job);
    return container.innerHTML;
  }

  function prettyPrint(opt_whenDone) {
    function byTagName(tn) { return document.getElementsByTagName(tn); }
    // fetch a list of nodes to rewrite
    var codeSegments = [byTagName('pre'), byTagName('code'), byTagName('xmp')];
    var elements = [];
    for (var i = 0; i < codeSegments.length; ++i) {
      for (var j = 0, n = codeSegments[i].length; j < n; ++j) {
        elements.push(codeSegments[i][j]);
      }
    }
    codeSegments = null;

    var clock = Date;
    if (!clock['now']) {
      clock = { 'now': function () { return (new Date).getTime(); } };
    }

    // The loop is broken into a series of continuations to make sure that we
    // don't make the browser unresponsive when rewriting a large page.
    var k = 0;
    var prettyPrintingJob;

    function doWork() {
      var endTime = (window['PR_SHOULD_USE_CONTINUATION'] ?
                     clock.now() + 250 /* ms */ :
                     Infinity);
      for (; k < elements.length && clock.now() < endTime; k++) {
        var cs = elements[k];
        if (cs.className && cs.className.indexOf('prettyprint') >= 0) {
          // If the classes includes a language extensions, use it.
          // Language extensions can be specified like
          //     <pre class="prettyprint lang-cpp">
          // the language extension "cpp" is used to find a language handler as
          // passed to PR.registerLangHandler.
          var langExtension = cs.className.match(/\blang-(\w+)\b/);
          if (langExtension) { langExtension = langExtension[1]; }

          // make sure this is not nested in an already prettified element
          var nested = false;
          for (var p = cs.parentNode; p; p = p.parentNode) {
            if ((p.tagName === 'pre' || p.tagName === 'code' ||
                 p.tagName === 'xmp') &&
                p.className && p.className.indexOf('prettyprint') >= 0) {
              nested = true;
              break;
            }
          }
          if (!nested) {
            // Look for a class like linenums or linenums:<n> where <n> is the
            // 1-indexed number of the first line.
            var lineNums = cs.className.match(/\blinenums\b(?::(\d+))?/);
            lineNums = lineNums
                  ? lineNums[1] && lineNums[1].length ? +lineNums[1] : true
                  : false;
            if (lineNums) { numberLines(cs, lineNums); }

            // do the pretty printing
            prettyPrintingJob = {
              langExtension: langExtension,
              sourceNode: cs,
              numberLines: lineNums
            };
            applyDecorator(prettyPrintingJob);
          }
        }
      }
      if (k < elements.length) {
        // finish up in a continuation
        setTimeout(doWork, 250);
      } else if (opt_whenDone) {
        opt_whenDone();
      }
    }

    doWork();
  }

  window['prettyPrintOne'] = prettyPrintOne;
  window['prettyPrint'] = prettyPrint;
  window['PR'] = {
        'createSimpleLexer': createSimpleLexer,
        'registerLangHandler': registerLangHandler,
        'sourceDecorator': sourceDecorator,
        'PR_ATTRIB_NAME': PR_ATTRIB_NAME,
        'PR_ATTRIB_VALUE': PR_ATTRIB_VALUE,
        'PR_COMMENT': PR_COMMENT,
        'PR_DECLARATION': PR_DECLARATION,
        'PR_KEYWORD': PR_KEYWORD,
        'PR_LITERAL': PR_LITERAL,
        'PR_NOCODE': PR_NOCODE,
        'PR_PLAIN': PR_PLAIN,
        'PR_PUNCTUATION': PR_PUNCTUATION,
        'PR_SOURCE': PR_SOURCE,
        'PR_STRING': PR_STRING,
        'PR_TAG': PR_TAG,
        'PR_TYPE': PR_TYPE
      };
})();