// 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 = [COMMON_KEYWORDS,
    		"abstract,add,alias,as,ascending,async,await,base,bool,by,byte,checked," +
    		"decimal,delegate,descending,dynamic,event,finally,fixed,foreach,from," +
    		"get,global,group,implicit,in,interface,internal,into,is,join,let,lock," +
    		"null,object,out,override,orderby,params,partial,readonly,ref,remove," +
    		"sbyte,sealed,select,set,stackalloc,string,uint,ulong,unchecked,unsafe," +
    		"ushort,value,var,virtual,where,yield"];
    	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 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(
    		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;
    		});
    	}
    })();