// 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. * *

* For a fairly comprehensive set of languages see the * README * 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. *

* Usage:

    *
  1. include this source file in an html page via * {@code } *
  2. define style rules. See the example page for examples. *
  3. mark the {@code
    } and {@code } tags in your source with
     *    {@code class=prettyprint.}
     *    You can also use the (html deprecated) {@code } 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, define */
    
    /** @define {boolean} */
    var IN_GLOBAL_SCOPE = true;
    
    /**
     * 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;
    
    /**
     * Pretty print a chunk of code.
     * @param {string} sourceCodeHtml The HTML to pretty print.
     * @param {string} opt_langExtension The language name to use.
     *     Typically, a filename extension like 'cpp' or 'java'.
     * @param {number|boolean} opt_numberLines True to number lines,
     *     or the 1-indexed number of the first line in sourceCodeHtml.
     * @return {string} code as html, but prettier
     */
    var prettyPrintOne;
    /**
     * Find all the {@code <pre>} and {@code <code>} tags in the DOM with
     * {@code class=prettyprint} and prettify them.
     *
     * @param {Function} opt_whenDone called when prettifying is done.
     * @param {HTMLElement|HTMLDocument} opt_root an element or document
     *   containing all the elements to pretty print.
     *   Defaults to {@code document.body}.
     */
    var prettyPrint;
    
    
    (function () {
      var win = window;
      // Keyword lists for various languages.
      // We use things that coerce to strings to make them compact when minified
      // and to defeat aggressive optimizers that fold large string constants.
      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,inline,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,delegate," +
          "dynamic_cast,explicit,export,friend,generic,late_check," +
          "mutable,namespace,nullptr,property,reinterpret_cast,static_assert," +
          "static_cast,template,typeid,typename,using,virtual,where"];
      var JAVA_KEYWORDS = [COMMON_KEYWORDS,
          "abstract,assert,boolean,byte,extends,final,finally,implements,import," +
          "instanceof,interface,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,internal,into,is,let," +
          "lock,object,out,override,orderby,params,partial,readonly,ref,sbyte," +
          "sealed,stackalloc,string,select,uint,ulong,unchecked,unsafe,ushort," +
          "var,virtual,where"];
      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," +
          "throw,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,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 RUST_KEYWORDS = [FLOW_CONTROL_KEYWORDS, "as,assert,const,copy,drop," +
          "enum,extern,fail,false,fn,impl,let,log,loop,match,mod,move,mut,priv," +
          "pub,pure,ref,self,static,struct,true,trait,type,unsafe,use"];
      var SH_KEYWORDS = [FLOW_CONTROL_KEYWORDS, "case,done,elif,esac,eval,fi," +
          "function,in,local,set,then,until"];
      var ALL_KEYWORDS = [
          CPP_KEYWORDS, CSHARP_KEYWORDS, JSCRIPT_KEYWORDS, PERL_KEYWORDS,
          PYTHON_KEYWORDS, RUBY_KEYWORDS, SH_KEYWORDS];
      var C_TYPES = /^(DIR|FILE|vector|(de|priority_)?queue|list|stack|(const_)?iterator|(multi)?(set|map)|bitset|u?(int|float)\d*)\b/;
    
      // token style names.  correspond to css classes
      /**
       * token style for a string literal
       * @const
       */
      var PR_STRING = 'str';
      /**
       * token style for a keyword
       * @const
       */
      var PR_KEYWORD = 'kwd';
      /**
       * token style for a comment
       * @const
       */
      var PR_COMMENT = 'com';
      /**
       * token style for a type
       * @const
       */
      var PR_TYPE = 'typ';
      /**
       * token style for a literal value.  e.g. 1, null, true.
       * @const
       */
      var PR_LITERAL = 'lit';
      /**
       * token style for a punctuation string.
       * @const
       */
      var PR_PUNCTUATION = 'pun';
      /**
       * token style for plain text.
       * @const
       */
      var PR_PLAIN = 'pln';
    
      /**
       * token style for an sgml tag.
       * @const
       */
      var PR_TAG = 'tag';
      /**
       * token style for a markup declaration such as a DOCTYPE.
       * @const
       */
      var PR_DECLARATION = 'dec';
      /**
       * token style for embedded source.
       * @const
       */
      var PR_SOURCE = 'src';
      /**
       * token style for an sgml attribute name.
       * @const
       */
      var PR_ATTRIB_NAME = 'atn';
      /**
       * token style for an sgml attribute value.
       * @const
       */
      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.
       * @const
       */
      var PR_NOCODE = 'nocode';
    
      
      
      /**
       * A set of tokens that can precede a regular expression literal in
       * javascript
       * http://web.archive.org/web/20070717142515/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 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
       * @const
       */
      var REGEXP_PRECEDER_PATTERN = '(?:^^\\.?|[+-]|[!=]=?=?|\\#|%=?|&&?=?|\\(|\\*=?|[+\\-]=|->|\\/=?|::?|<<?=?|>>?>?=?|,|;|\\?|@|\\[|~|{|\\^\\^?=?|\\|\\|?=?|break|case|continue|delete|do|else|finally|instanceof|return|throw|try|typeof)\\s*';
      
      // 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;
          }
        }
      
        var escapeCharToCodeUnit = {
          'b': 8,
          't': 9,
          'n': 0xa,
          'v': 0xb,
          'f': 0xc,
          'r': 0xd
        };
      
        function decodeEscape(charsetPart) {
          var cc0 = charsetPart.charCodeAt(0);
          if (cc0 !== 92 /* \\ */) {
            return cc0;
          }
          var c1 = charsetPart.charAt(1);
          cc0 = escapeCharToCodeUnit[c1];
          if (cc0) {
            return cc0;
          } else if ('0' <= c1 && c1 <= '7') {
            return parseInt(charsetPart.substring(1), 8);
          } else if (c1 === 'u' || c1 === 'x') {
            return parseInt(charsetPart.substring(2), 16);
          } else {
            return charsetPart.charCodeAt(1);
          }
        }
      
        function encodeEscape(charCode) {
          if (charCode < 0x20) {
            return (charCode < 0x10 ? '\\x0' : '\\x') + charCode.toString(16);
          }
          var ch = String.fromCharCode(charCode);
          return (ch === '\\' || ch === '-' || ch === ']' || ch === '^')
              ? "\\" + ch : 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 ranges = [];
          var inverse = charsetParts[0] === '^';
      
          var out = ['['];
          if (inverse) { out.push('^'); }
      
          for (var i = inverse ? 1 : 0, n = charsetParts.length; i < n; ++i) {
            var p = charsetParts[i];
            if (/\\[bdsw]/i.test(p)) {  // Don't muck with named groups.
              out.push(p);
            } else {
              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.
              // This case handling is too simplistic.
              // It does not deal with non-latin case folding.
              // It works for latin source code identifiers though.
              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 = [];
          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);
            }
          }
      
          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/end 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) {
                if (decimalValue <= groupIndex) {
                  capturedGroups[decimalValue] = -1;
                } else {
                  // Replace with an unambiguous escape sequence so that
                  // an octal escape sequence does not turn into a backreference
                  // to a capturing group from an earlier regex.
                  parts[i] = encodeEscape(decimalValue);
                }
              }
            }
          }
      
          // 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]) {
                parts[i] = '(?:';
              }
            } else if ('\\' === p.charAt(0)) {
              var decimalValue = +p.substring(1);
              if (decimalValue && decimalValue <= groupIndex) {
                parts[i] = '\\' + capturedGroups[decimalValue];
              }
            }
          }
      
          // Remove any prefix anchors so that the output will match anywhere.
          // ^^ really does mean an anchored match though.
          for (var i = 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>
       * {
       *   sourceCode: "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.
       * @param {boolean} isPreformatted true if white-space in text nodes should
       *    be considered significant.
       * @return {Object} source code and the text nodes in which they occur.
       */
      function extractSourceSpans(node, isPreformatted) {
        var nocode = /(?:^|\s)nocode(?:\s|$)/;
      
        var chunks = [];
        var length = 0;
        var spans = [];
        var k = 0;
      
        function walk(node) {
          var type = node.nodeType;
          if (type == 1) {  // Element
            if (nocode.test(node.className)) { return; }
            for (var child = node.firstChild; child; child = child.nextSibling) {
              walk(child);
            }
            var nodeName = node.nodeName.toLowerCase();
            if ('br' === nodeName || 'li' === nodeName) {
              chunks[k] = '\n';
              spans[k << 1] = length++;
              spans[(k++ << 1) | 1] = node;
            }
          } else if (type == 3 || type == 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;
            }
          }
        }
      
        walk(node);
      
        return {
          sourceCode: 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 = {
          sourceCode: sourceCode,
          basePos: basePos
        };
        langHandler(job);
        out.push.apply(out, job.decorations);
      }
    
      var notWs = /\S/;
    
      /**
       * Given an element, if it contains only one child element and any text nodes
       * it contains contain only space characters, return the sole child element.
       * Otherwise returns undefined.
       * <p>
       * This is meant to return the CODE element in {@code <pre><code ...>} when
       * there is a single child element that contains all the non-space textual
       * content, but not to return anything where there are multiple child elements
       * as in {@code <pre><code>...</code><code>...</code></pre>} or when there
       * is textual content.
       */
      function childContentWrapper(element) {
        var wrapper = undefined;
        for (var c = element.firstChild; c; c = c.nextSibling) {
          var type = c.nodeType;
          wrapper = (type === 1)  // Element Node
              ? (wrapper ? element : c)
              : (type === 3)  // Text Node
              ? (notWs.test(c.nodeValue) ? element : wrapper)
              : wrapper;
        }
        return wrapper === element ? undefined : wrapper;
      }
    
      /** 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;
    
        /**
         * Lexes job.sourceCode and produces an output array job.decorations of
         * style classes preceded by the position at which they start in
         * job.sourceCode in order.
         *
         * @param {Object} job an object like <pre>{
         *    sourceCode: {string} sourceText plain text,
         *    basePos: {int} position of job.sourceCode in the larger chunk of
         *        sourceCode.
         * }</pre>
         */
        var decorate = function (job) {
          var sourceCode = job.sourceCode, 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, /^#(?:##(?:[^#]|#(?!##))*(?:###|$)|.*)/, null, '#']);
            } else {
              // Stop C preprocessor declarations at an unclosed open comment
              shortcutStylePatterns.push(
                  [PR_COMMENT, /^#(?:(?:define|e(?:l|nd)if|else|error|ifn?def|include|line|pragma|undef|warning)\b|[^\r\n]*)/,
                   null, '#']);
            }
            // #include <stdio.h>
            fallthroughStylePatterns.push(
                [PR_STRING,
                 /^<(?:(?:(?:\.\.\/)*|\/?)(?:[\w-]+(?:\/[\w-]+)+)?[\w-]+\.h(?:h|pp|\+\+)?|[a-z]\w*)>/,
                 null]);
          } else {
            shortcutStylePatterns.push([PR_COMMENT, /^#[^\r\n]*/, null, '#']);
          }
        }
        if (options['cStyleComments']) {
          fallthroughStylePatterns.push([PR_COMMENT, /^\/\/[^\r\n]*/, null]);
          fallthroughStylePatterns.push(
              [PR_COMMENT, /^\/\*[\s\S]*?(?:\*\/|$)/, null]);
        }
        var regexLiterals = options['regexLiterals'];
        if (regexLiterals) {
          /**
           * @const
           */
          var regexExcls = regexLiterals > 1
            ? ''  // Multiline regex literals
            : '\n\r';
          /**
           * @const
           */
          var regexAny = regexExcls ? '.' : '[\\S\\s]';
          /**
           * @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.
              '/(?=[^/*' + regexExcls + '])'
              // and then contains any number of raw characters,
              + '(?:[^/\\x5B\\x5C' + regexExcls + ']'
              // escape sequences (\x5C),
              +    '|\\x5C' + regexAny
              // or non-nesting character sets (\x5B\x5D);
              +    '|\\x5B(?:[^\\x5C\\x5D' + regexExcls + ']'
              +             '|\\x5C' + regexAny + ')*(?:\\x5D|$))+'
              // finally closed by a /.
              + '/');
          fallthroughStylePatterns.push(
              ['lang-regex',
               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']);
    
        var punctuation =
          // The Bash man page says
    
          // A word is a sequence of characters considered as a single
          // unit by GRUB. Words are separated by metacharacters,
          // which are the following plus space, tab, and newline: { }
          // | & $ ; < >
          // ...
          
          // A word beginning with # causes that word and all remaining
          // characters on that line to be ignored.
    
          // which means that only a '#' after /(?:^|[{}|&$;<>\s])/ starts a
          // comment but empirically
          // $ echo {#}
          // {#}
          // $ echo \$#
          // $#
          // $ echo }#
          // }#
    
          // so /(?:^|[|&;<>\s])/ is more appropriate.
    
          // http://gcc.gnu.org/onlinedocs/gcc-2.95.3/cpp_1.html#SEC3
          // suggests that this definition is compatible with a
          // default mode that tries to use a single token definition
          // to recognize both bash/python style comments and C
          // preprocessor directives.
    
          // This definition of punctuation does not include # in the list of
          // follow-on exclusions, so # will not be broken before if preceeded
          // by a punctuation character.  We could try to exclude # after
          // [|&;<>] but that doesn't seem to cause many major problems.
          // If that does turn out to be a problem, we should change the below
          // when hc is truthy to include # in the run of punctuation characters
          // only when not followint [|&;<>].
          '^.[^\\s\\w.$@\'"`/\\\\]*';
        if (options['regexLiterals']) {
          punctuation += '(?!\s*\/)';
        }
    
        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, new RegExp(punctuation), 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.
       * @param {boolean} isPreformatted true iff white-space in text nodes should
       *     be treated as significant.
       */
      function numberLines(node, opt_startLineNum, isPreformatted) {
        var nocode = /(?:^|\s)nocode(?:\s|$)/;
        var lineBreak = /\r\n?|\n/;
      
        var document = node.ownerDocument;
      
        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) {
          var type = node.nodeType;
          if (type == 1 && !nocode.test(node.className)) {  // Element
            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);
              }
            }
          } else if ((type == 3 || type == 4) && isPreformatted) {  // Text
            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);
              }
            }
          }
        }
      
        // 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.sourceCode} around style boundaries in
       * {@code job.decorations} and modifies {@code job.sourceNode} in place.
       * @param {Object} job like <pre>{
       *    sourceCode: {string} source as plain text,
       *    sourceNode: {HTMLElement} the element containing the source,
       *    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.sourceCode in order
       * }</pre>
       * @private
       */
      function recombineTagsAndDecorations(job) {
        var isIE8OrEarlier = /\bMSIE\s(\d+)/.exec(navigator.userAgent);
        isIE8OrEarlier = isIE8OrEarlier && +isIE8OrEarlier[1] <= 8;
        var newlineRe = /\n/g;
      
        var source = job.sourceCode;
        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;
      
        // Remove all zero-length decorations.
        decorations[nDecorations] = sourceLength;
        var decPos, i;
        for (i = decPos = 0; i < nDecorations;) {
          if (decorations[i] !== decorations[i + 2]) {
            decorations[decPos++] = decorations[i++];
            decorations[decPos++] = decorations[i++];
          } else {
            i += 2;
          }
        }
        nDecorations = decPos;
      
        // Simplify decorations.
        for (i = decPos = 0; i < nDecorations;) {
          var startPos = decorations[i];
          // Conflate all adjacent decorations that use the same style.
          var startDec = decorations[i + 1];
          var end = i + 2;
          while (end + 2 <= nDecorations && decorations[end + 1] === startDec) {
            end += 2;
          }
          decorations[decPos++] = startPos;
          decorations[decPos++] = startDec;
          i = end;
        }
      
        nDecorations = decorations.length = decPos;
      
        var sourceNode = job.sourceNode;
        var oldDisplay;
        if (sourceNode) {
          oldDisplay = sourceNode.style.display;
          sourceNode.style.display = 'none';
        }
        try {
          var decoration = null;
          while (spanIndex < nSpans) {
            var spanStart = spans[spanIndex];
            var spanEnd = spans[spanIndex + 2] || sourceLength;
      
            var decEnd = decorations[decorationIndex + 2] || sourceLength;
      
            var end = Math.min(spanEnd, decEnd);
      
            var textNode = spans[spanIndex + 1];
            var styledText;
            if (textNode.nodeType !== 1  // Don't muck with <BR>s or <LI>s
                // Don't introduce spans around empty text nodes.
                && (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 (isIE8OrEarlier) {
                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;
            }
          }
        } finally {
          if (sourceNode) {
            sourceNode.style.display = oldDisplay;
          }
        }
      }
    
      /** 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 {
        *        sourceCode: {string} as plain text.
        *        decorations: {Array.<number|string>} an array of style classes
        *                     preceded by the position at which they start in
        *                     job.sourceCode 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 (win['console']) {
            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,
              'types': C_TYPES
            }), ['c', 'cc', 'cpp', 'cxx', 'cyc', 'm']);
      registerLangHandler(sourceDecorator({
              'keywords': 'null,true,false'
            }), ['json']);
      registerLangHandler(sourceDecorator({
              'keywords': CSHARP_KEYWORDS,
              'hashComments': true,
              'cStyleComments': true,
              'verbatimStrings': true,
              'types': C_TYPES
            }), ['cs']);
      registerLangHandler(sourceDecorator({
              'keywords': JAVA_KEYWORDS,
              'cStyleComments': true
            }), ['java']);
      registerLangHandler(sourceDecorator({
              'keywords': SH_KEYWORDS,
              'hashComments': true,
              'multiLineStrings': true
            }), ['bash', 'bsh', 'csh', 'sh']);
      registerLangHandler(sourceDecorator({
              'keywords': PYTHON_KEYWORDS,
              'hashComments': true,
              'multiLineStrings': true,
              'tripleQuotedStrings': true
            }), ['cv', 'py', 'python']);
      registerLangHandler(sourceDecorator({
              'keywords': PERL_KEYWORDS,
              'hashComments': true,
              'multiLineStrings': true,
              'regexLiterals': 2  // multiline regex literals
            }), ['perl', 'pl', 'pm']);
      registerLangHandler(sourceDecorator({
              'keywords': RUBY_KEYWORDS,
              'hashComments': true,
              'multiLineStrings': true,
              'regexLiterals': true
            }), ['rb', 'ruby']);
      registerLangHandler(sourceDecorator({
              'keywords': JSCRIPT_KEYWORDS,
              'cStyleComments': true,
              'regexLiterals': true
            }), ['javascript', 'js']);
      registerLangHandler(sourceDecorator({
              'keywords': COFFEE_KEYWORDS,
              'hashComments': 3,  // ### style block comments
              'cStyleComments': true,
              'multilineStrings': true,
              'tripleQuotedStrings': true,
              'regexLiterals': true
            }), ['coffee']);
      registerLangHandler(sourceDecorator({
              'keywords': RUST_KEYWORDS,
              'cStyleComments': true,
              'multilineStrings': true
            }), ['rc', 'rs', 'rust']);
      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, job.pre);
          /** Plain text. @type {string} */
          var source = sourceAndSpans.sourceCode;
          job.sourceCode = 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 (win['console']) {
            console['log'](e && e['stack'] || e);
          }
        }
      }
    
      /**
       * Pretty print a chunk of code.
       * @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('div');
        // 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.
        // The pre-tag is required for IE8 which strips newlines from innerHTML
        // when it is injected into a <pre> tag.
        // http://stackoverflow.com/questions/451486/pre-tag-loses-line-breaks-when-setting-innerhtml-in-ie
        // http://stackoverflow.com/questions/195363/inserting-a-newline-into-a-pre-tag-ie-javascript
        container.innerHTML = '<pre>' + sourceCodeHtml + '</pre>';
        container = container.firstChild;
        if (opt_numberLines) {
          numberLines(container, opt_numberLines, true);
        }
    
        var job = {
          langExtension: opt_langExtension,
          numberLines: opt_numberLines,
          sourceNode: container,
          pre: 1
        };
        applyDecorator(job);
        return container.innerHTML;
      }
    
       /**
        * Find all the {@code <pre>} and {@code <code>} tags in the DOM with
        * {@code class=prettyprint} and prettify them.
        *
        * @param {Function} opt_whenDone called when prettifying is done.
        * @param {HTMLElement|HTMLDocument} opt_root an element or document
        *   containing all the elements to pretty print.
        *   Defaults to {@code document.body}.
        */
      function $prettyPrint(opt_whenDone, opt_root) {
        var root = opt_root || document.body;
        var doc = root.ownerDocument || document;
        function byTagName(tn) { return root.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); } };
        }
    
        // 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;
    
        var langExtensionRe = /\blang(?:uage)?-([\w.]+)(?!\S)/;
        var prettyPrintRe = /\bprettyprint\b/;
        var prettyPrintedRe = /\bprettyprinted\b/;
        var preformattedTagNameRe = /pre|xmp/i;
        var codeRe = /^code$/i;
        var preCodeXmpRe = /^(?:pre|code|xmp)$/i;
        var EMPTY = {};
    
        function doWork() {
          var endTime = (win['PR_SHOULD_USE_CONTINUATION'] ?
                         clock['now']() + 250 /* ms */ :
                         Infinity);
          for (; k < elements.length && clock['now']() < endTime; k++) {
            var cs = elements[k];
    
            // Look for a preceding comment like
            // <?prettify lang="..." linenums="..."?>
            var attrs = EMPTY;
            {
              for (var preceder = cs; (preceder = preceder.previousSibling);) {
                var nt = preceder.nodeType;
                // <?foo?> is parsed by HTML 5 to a comment node (8)
                // like <!--?foo?-->, but in XML is a processing instruction
                var value = (nt === 7 || nt === 8) && preceder.nodeValue;
                if (value
                    ? !/^\??prettify\b/.test(value)
                    : (nt !== 3 || /\S/.test(preceder.nodeValue))) {
                  // Skip over white-space text nodes but not others.
                  break;
                }
                if (value) {
                  attrs = {};
                  value.replace(
                      /\b(\w+)=([\w:.%+-]+)/g,
                    function (_, name, value) { attrs[name] = value; });
                  break;
                }
              }
            }
    
            var className = cs.className;
            if ((attrs !== EMPTY || prettyPrintRe.test(className))
                // Don't redo this if we've already done it.
                // This allows recalling pretty print to just prettyprint elements
                // that have been added to the page since last call.
                && !prettyPrintedRe.test(className)) {
    
              // make sure this is not nested in an already prettified element
              var nested = false;
              for (var p = cs.parentNode; p; p = p.parentNode) {
                var tn = p.tagName;
                if (preCodeXmpRe.test(tn)
                    && p.className && prettyPrintRe.test(p.className)) {
                  nested = true;
                  break;
                }
              }
              if (!nested) {
                // Mark done.  If we fail to prettyprint for whatever reason,
                // we shouldn't try again.
                cs.className += ' prettyprinted';
    
                // 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.
                // HTML5 recommends that a language be specified using "language-"
                // as the prefix instead.  Google Code Prettify supports both.
                // http://dev.w3.org/html5/spec-author-view/the-code-element.html
                var langExtension = attrs['lang'];
                if (!langExtension) {
                  langExtension = className.match(langExtensionRe);
                  // Support <pre class="prettyprint"><code class="language-c">
                  var wrapper;
                  if (!langExtension && (wrapper = childContentWrapper(cs))
                      && codeRe.test(wrapper.tagName)) {
                    langExtension = wrapper.className.match(langExtensionRe);
                  }
    
                  if (langExtension) { langExtension = langExtension[1]; }
                }
    
                var preformatted;
                if (preformattedTagNameRe.test(cs.tagName)) {
                  preformatted = 1;
                } else {
                  var currentStyle = cs['currentStyle'];
                  var defaultView = doc.defaultView;
                  var whitespace = (
                      currentStyle
                      ? currentStyle['whiteSpace']
                      : (defaultView
                         && defaultView.getComputedStyle)
                      ? defaultView.getComputedStyle(cs, null)
                      .getPropertyValue('white-space')
                      : 0);
                  preformatted = whitespace
                      && 'pre' === whitespace.substring(0, 3);
                }
    
                // Look for a class like linenums or linenums:<n> where <n> is the
                // 1-indexed number of the first line.
                var lineNums = attrs['linenums'];
                if (!(lineNums = lineNums === 'true' || +lineNums)) {
                  lineNums = className.match(/\blinenums\b(?::(\d+))?/);
                  lineNums =
                    lineNums
                    ? lineNums[1] && lineNums[1].length
                      ? +lineNums[1] : true
                    : false;
                }
                if (lineNums) { numberLines(cs, lineNums, preformatted); }
    
                // do the pretty printing
                prettyPrintingJob = {
                  langExtension: langExtension,
                  sourceNode: cs,
                  numberLines: lineNums,
                  pre: preformatted
                };
                applyDecorator(prettyPrintingJob);
              }
            }
          }
          if (k < elements.length) {
            // finish up in a continuation
            setTimeout(doWork, 250);
          } else if ('function' === typeof opt_whenDone) {
            opt_whenDone();
          }
        }
    
        doWork();
      }
    
      /**
       * Contains functions for creating and registering new language handlers.
       * @type {Object}
       */
      var PR = win['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,
            'prettyPrintOne':
               IN_GLOBAL_SCOPE
                 ? (win['prettyPrintOne'] = $prettyPrintOne)
                 : (prettyPrintOne = $prettyPrintOne),
            'prettyPrint': prettyPrint =
               IN_GLOBAL_SCOPE
                 ? (win['prettyPrint'] = $prettyPrint)
                 : (prettyPrint = $prettyPrint)
          };
    
      // Make PR available via the Asynchronous Module Definition (AMD) API.
      // Per https://github.com/amdjs/amdjs-api/wiki/AMD:
      // The Asynchronous Module Definition (AMD) API specifies a
      // mechanism for defining modules such that the module and its
      // dependencies can be asynchronously loaded.
      // ...
      // To allow a clear indicator that a global define function (as
      // needed for script src browser loading) conforms to the AMD API,
      // any global define function SHOULD have a property called "amd"
      // whose value is an object. This helps avoid conflict with any
      // other existing JavaScript code that could have defined a define()
      // function that does not conform to the AMD API.
      if (typeof define === "function" && define['amd']) {
        define("google-code-prettify", [], function () {
          return PR; 
        });
      }
    })();