/*

	XSLT jQuery Plugin - Copyright (C) 2007, Jorrit Jongma (Chainfire) 

	Version: 0.70
	Homepage: http://www.jongma.org/webtools/jquery/
	License: MIT / Public Domain (whatever works for you)
		NOTE: The AJAXSLT code is	included below, which has an alternate license, 
		which is pasted below the	jQuery plugin code!

	From webpage:

	This is a jQuery Plugin for Google's AJAXSLT ( http://code.google.com/p/ajaxslt/ ). It gives you the
	ability to transform XML/XSL from JavaScript. AJAXSLT is a parser itself, the library does not depend on 
	your browser being able to do XSL transforms. The plugin also provides functionality to load XML/XSL through
	$.ajax() calls and transform them.
	
	Documentation: http://www.jongma.org/webtools/jquery/xslt/

	Compatibility: 1.1.3

*/

(function($) {
	// $.xslt(options) - Return transformed XML
	$.xslt = function(options) {
		// Default settings
		var opt = {
			xml: null,
			xmlUrl: null,
			xmlCache: true,
			
			xsl: null,
			xslUrl: null,
			xslCache: true,
			
			callback: null,
			target: null,
			
			dataTypeXML: false,
			
			error: false			
		};
		$.extend(opt, options);

		// Can we go async?
		opt.async = ((opt.callback != null) || (opt.target != null));

		// Setup finish function
		opt.finish = function(opt) {
			if ((opt.xml != null) && (opt.xsl != null) && (opt.error == false)) {
				// We got the data and no error occured

				// Convert text to XML nodes if necessary
				if ((opt.xml !== null) && (typeof(opt.xml) != 'object')) {
					opt.xml = $.xslt.textToXML(opt.xml);
				}
				if ((opt.xsl !== null) && (typeof(opt.xsl) != 'object')) {
					opt.xsl = $.xslt.textToXML(opt.xsl);
				}

				// Perform the transform
				var output = xsltProcess(opt.xml, opt.xsl);

				// Callback
				if (opt.callback != null) {
					opt.callback(output);
				}

				// Set target content to transformed XML
				if (opt.target != null) {
					$(opt.target).html(output);
				}

				// Return output for sync calls
				return output;
			} else if (opt.error) {
				// Error occured
				if (opt.callback != null) {
					opt.callback(false);
				}
				return false;				
			} else {
				// Data not in yet
				return true;
			}
		}				

		if (((opt.xml == null) && (opt.xmlUrl == null)) || ((opt.xsl == null) && (opt.xslUrl == null))) {
			// Not going to work.
		  opt.error = true;
		  return opt.finish(opt);
		}

		// Retrieve XML and XSL from cache if possible
		if ((opt.xml == null) && (opt.xmlUrl != null) && (opt.xmlCache == true) && ($.xslt.cache.xml[opt.xmlUrl])) {
			opt.xml = $.xslt.cache.xml[opt.xmlUrl];
		}

		if ((opt.xsl == null) && (opt.xslUrl != null) && (opt.xslCache == true) && ($.xslt.cache.xsl[opt.xslUrl])) {
			opt.xsl = $.xslt.cache.xsl[opt.xslUrl];
		}

		// Get XML and XSL from url if necessary		
		if ((opt.xmlUrl != null) && (opt.xml == null)) {
			$.ajax({
				url: opt.xmlUrl,
				dataType: opt.dataTypeXML ? 'xml' : 'html',
				error: function() {
					opt.error = true;
					opt.finish(opt);
				},
				success: function(data) {
					opt.xml = data;
					if (opt.xmlCache) {
						$.xslt.cache.xml[opt.xmlUrl] = opt.dataTypeXML ? data : $.xslt.textToXML(data);
					}
					opt.finish(opt);
				},
				async: opt.async
			});
		}

		if ((opt.xslUrl != null) && (opt.xsl == null)) {
			$.ajax({
				url: opt.xslUrl,
				dataType: opt.dataTypeXML ? 'xml' : 'html',
				error: function() {
					opt.error = true;
					opt.finish(opt);
				},
				success: function(data) {
					opt.xsl = data;
					if (opt.xslCache) {
						$.xslt.cache.xsl[opt.xslUrl] = opt.dataTypeXML ? data : $.xslt.textToXML(data);
					}
					opt.finish(opt);
				},
				async: opt.async
			});
		}

		// Return the transformed XML (string) if we're done, true if 
		// we're working async, false if there has been an error
		return opt.finish(opt);
	}

	$.extend($.xslt, {
		// $.xslt.version.plugin - Plugin version
		// $.xslt.version.ajaxslt - AJAXSLT version
		version: {
			plugin: 0.70,
			ajaxslt: 0.7
		},

		// $.xslt.textToXML(text) - Convert text to XML DOM node
		textToXML: function(text) {
			return xmlParse(text);
		},

		// $.xslt.xmlToText(xml) - Convert XML DOM node to text
		xmlToText: function(xml) {
			return xmlText(xml);
		},

		// XML / XSL cache
		cache: {
			xml: {},
			xsl: {}
		}
	});

	// $(...).xslt(options) - Set content to transformed XML
	// xml and xsl parameters should be DOM nodes (not text)
	$.fn.xslt = function(options) {
		options.target = this;
		$.xslt(options);
		return this;
	}
})(jQuery);

/* 

	Below here is the code from AJAXSLT 0.7, see http://code.google.com/p/ajaxslt/ 
	Code above here is licensed MIT, license for the code below is following:

*/

/*

Copyright (c) 2005,2006 Google Inc.
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
        
 * Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.

 * Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the
   distribution.

 * Neither the name of Google Inc. nor the names of its contributors
   may be used to endorse or promote products derived from this
   software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*/

// Copyright 2005 Google
//
// Author: Steffen Meschkat <mesch@google.com>
//
// Miscellaneous utility and placeholder functions.

// Dummy implmentation for the logging functions. Replace by something
// useful when you want to debug.
function xpathLog(msg) {};
function xsltLog(msg) {};
function xsltLogXml(msg) {};

// Throws an exception if false.
function assert(b) {
  if (!b) {
    throw "Assertion failed";
  }
}

// Splits a string s at all occurrences of character c. This is like
// the split() method of the string object, but IE omits empty
// strings, which violates the invariant (s.split(x).join(x) == s).
function stringSplit(s, c) {
  var a = s.indexOf(c);
  if (a == -1) {
    return [ s ];
  }
  var parts = [];
  parts.push(s.substr(0,a));
  while (a != -1) {
    var a1 = s.indexOf(c, a + 1);
    if (a1 != -1) {
      parts.push(s.substr(a + 1, a1 - a - 1));
    } else {
      parts.push(s.substr(a + 1));
    }
    a = a1;
  }
  return parts;
}

// The following function does what document.importNode(node, true)
// would do for us here; however that method is broken in Safari/1.3,
// so we have to emulate it.
function xmlImportNode(doc, node) {
  if (node.nodeType == DOM_TEXT_NODE) {
    return domCreateTextNode(doc, node.nodeValue);

  } else if (node.nodeType == DOM_CDATA_SECTION_NODE) {
    return domCreateCDATASection(doc, node.nodeValue);

  } else if (node.nodeType == DOM_ELEMENT_NODE) {
    var newNode = domCreateElement(doc, node.nodeName);
    for (var i = 0; i < node.attributes.length; ++i) {
      var an = node.attributes[i];
      var name = an.nodeName;
      var value = an.nodeValue;
      domSetAttribute(newNode, name, value);
    }

    for (var c = node.firstChild; c; c = c.nextSibling) {
      var cn = arguments.callee(doc, c);
      domAppendChild(newNode, cn);
    }

    return newNode;

  } else {
    return domCreateComment(doc, node.nodeName);
  }
}

// A set data structure. It can also be used as a map (i.e. the keys
// can have values other than 1), but we don't call it map because it
// would be ambiguous in this context. Also, the map is iterable, so
// we can use it to replace for-in loops over core javascript Objects.
// For-in iteration breaks when Object.prototype is modified, which
// some clients of the maps API do.
//
// NOTE(mesch): The set keys by the string value of its element, NOT
// by the typed value. In particular, objects can't be used as keys.
//
// @constructor
function Set() {
  this.keys = [];
}

Set.prototype.size = function() {
  return this.keys.length;
}

// Adds the entry to the set, ignoring if it is present.
Set.prototype.add = function(key, opt_value) {
  var value = opt_value || 1;
  if (!this.contains(key)) {
    this[':' + key] = value;
    this.keys.push(key);
  }
}

// Sets the entry in the set, adding if it is not yet present.
Set.prototype.set = function(key, opt_value) {
  var value = opt_value || 1;
  if (!this.contains(key)) {
    this[':' + key] = value;
    this.keys.push(key);
  } else {
    this[':' + key] = value;
  }
}

// Increments the key's value by 1. This works around the fact that
// numbers are always passed by value, never by reference, so that we
// can't increment the value returned by get(), or the iterator
// argument. Sets the key's value to 1 if it doesn't exist yet.
Set.prototype.inc = function(key) {
  if (!this.contains(key)) {
    this[':' + key] = 1;
    this.keys.push(key);
  } else {
    this[':' + key]++;
  }
}

Set.prototype.get = function(key) {
  if (this.contains(key)) {
    return this[':' + key];
  } else {
    var undefined;
    return undefined;
  }
}

// Removes the entry from the set.
Set.prototype.remove = function(key) {
  if (this.contains(key)) {
    delete this[':' + key];
    removeFromArray(this.keys, key, true);
  }
}

// Tests if an entry is in the set.
Set.prototype.contains = function(entry) {
  return typeof this[':' + entry] != 'undefined';
}

// Gets a list of values in the set.
Set.prototype.items = function() {
  var list = [];
  for (var i = 0; i < this.keys.length; ++i) {
    var k = this.keys[i];
    var v = this[':' + k];
    list.push(v);
  }
  return list;
}


// Invokes function f for every key value pair in the set as a method
// of the set.
Set.prototype.map = function(f) {
  for (var i = 0; i < this.keys.length; ++i) {
    var k = this.keys[i];
    f.call(this, k, this[':' + k]);
  }
}

Set.prototype.clear = function() {
  for (var i = 0; i < this.keys.length; ++i) {
    delete this[':' + this.keys[i]];
  }
  this.keys.length = 0;
}


// Applies the given function to each element of the array, preserving
// this, and passing the index.
function mapExec(array, func) {
  for (var i = 0; i < array.length; ++i) {
    func.call(this, array[i], i);
  }
}

// Returns an array that contains the return value of the given
// function applied to every element of the input array.
function mapExpr(array, func) {
  var ret = [];
  for (var i = 0; i < array.length; ++i) {
    ret.push(func(array[i]));
  }
  return ret;
};

// Reverses the given array in place.
function reverseInplace(array) {
  for (var i = 0; i < array.length / 2; ++i) {
    var h = array[i];
    var ii = array.length - i - 1;
    array[i] = array[ii];
    array[ii] = h;
  }
}

// Removes value from array. Returns the number of instances of value
// that were removed from array.
function removeFromArray(array, value, opt_notype) {
  var shift = 0;
  for (var i = 0; i < array.length; ++i) {
    if (array[i] === value || (opt_notype && array[i] == value)) {
      array.splice(i--, 1);
      shift++;
    }
  }
  return shift;
}

// Shallow-copies an array.
function copyArray(dst, src) {
  for (var i = 0; i < src.length; ++i) {
    dst.push(src[i]);
  }
}

// Returns the text value of a node; for nodes without children this
// is the nodeValue, for nodes with children this is the concatenation
// of the value of all children.
function xmlValue(node) {
  if (!node) {
    return '';
  }

  var ret = '';
  if (node.nodeType == DOM_TEXT_NODE ||
      node.nodeType == DOM_CDATA_SECTION_NODE ||
      node.nodeType == DOM_ATTRIBUTE_NODE) {
    ret += node.nodeValue;

  } else if (node.nodeType == DOM_ELEMENT_NODE ||
             node.nodeType == DOM_DOCUMENT_NODE ||
             node.nodeType == DOM_DOCUMENT_FRAGMENT_NODE) {
    for (var i = 0; i < node.childNodes.length; ++i) {
      ret += arguments.callee(node.childNodes[i]);
    }
  }
  return ret;
}

// Returns the representation of a node as XML text.
function xmlText(node, opt_cdata) {
  var buf = [];
  xmlTextR(node, buf, opt_cdata);
  return buf.join('');
}

function xmlTextR(node, buf, cdata) {
  if (node.nodeType == DOM_TEXT_NODE) {
    buf.push(xmlEscapeText(node.nodeValue));

  } else if (node.nodeType == DOM_CDATA_SECTION_NODE) {
    if (cdata) {
      buf.push(node.nodeValue);
    } else {
      buf.push('<![CDATA[' + node.nodeValue + ']]>');
    }

  } else if (node.nodeType == DOM_COMMENT_NODE) {
    buf.push('<!--' + node.nodeValue + '-->');

  } else if (node.nodeType == DOM_ELEMENT_NODE) {
    buf.push('<' + xmlFullNodeName(node));
    for (var i = 0; i < node.attributes.length; ++i) {
      var a = node.attributes[i];
      if (a && a.nodeName && a.nodeValue) {
        buf.push(' ' + xmlFullNodeName(a) + '="' +
                 xmlEscapeAttr(a.nodeValue) + '"');
      }
    }

    if (node.childNodes.length == 0) {
      buf.push('/>');
    } else {
      buf.push('>');
      for (var i = 0; i < node.childNodes.length; ++i) {
        arguments.callee(node.childNodes[i], buf, cdata);
      }
      buf.push('</' + xmlFullNodeName(node) + '>');
    }

  } else if (node.nodeType == DOM_DOCUMENT_NODE ||
             node.nodeType == DOM_DOCUMENT_FRAGMENT_NODE) {
    for (var i = 0; i < node.childNodes.length; ++i) {
      arguments.callee(node.childNodes[i], buf, cdata);
    }
  }
}

function xmlFullNodeName(n) {
  if (n.prefix && n.nodeName.indexOf(n.prefix + ':') != 0) {
    return n.prefix + ':' + n.nodeName;
  } else {
    return n.nodeName;
  }
}

// Escape XML special markup chracters: tag delimiter < > and entity
// reference start delimiter &. The escaped string can be used in XML
// text portions (i.e. between tags).
function xmlEscapeText(s) {
  return ('' + s).replace(/&/g, '&amp;').replace(/</g, '&lt;').
    replace(/>/g, '&gt;');
}

// Escape XML special markup characters: tag delimiter < > entity
// reference start delimiter & and quotes ". The escaped string can be
// used in double quoted XML attribute value portions (i.e. in
// attributes within start tags).
function xmlEscapeAttr(s) {
  return xmlEscapeText(s).replace(/\"/g, '&quot;');
}

// Escape markup in XML text, but don't touch entity references. The
// escaped string can be used as XML text (i.e. between tags).
function xmlEscapeTags(s) {
  return s.replace(/</g, '&lt;').replace(/>/g, '&gt;');
}

/**
 * Wrapper function to access the owner document uniformly for document
 * and other nodes: for the document node, the owner document is the
 * node itself, for all others it's the ownerDocument property.
 *
 * @param {Node} node
 * @return {Document}
 */
function xmlOwnerDocument(node) {
  if (node.nodeType == DOM_DOCUMENT_NODE) {
    return node;
  } else {
    return node.ownerDocument;
  }
}

// Wrapper around DOM methods so we can condense their invocations.
function domGetAttribute(node, name) {
  return node.getAttribute(name);
}

function domSetAttribute(node, name, value) {
  return node.setAttribute(name, value);
}

function domRemoveAttribute(node, name) {
  return node.removeAttribute(name);
}

function domAppendChild(node, child) {
  return node.appendChild(child);
}

function domRemoveChild(node, child) {
  return node.removeChild(child);
}

function domReplaceChild(node, newChild, oldChild) {
  return node.replaceChild(newChild, oldChild);
}

function domInsertBefore(node, newChild, oldChild) {
  return node.insertBefore(newChild, oldChild);
}

function domRemoveNode(node) {
  return domRemoveChild(node.parentNode, node);
}

function domCreateTextNode(doc, text) {
  return doc.createTextNode(text);
}

function domCreateElement(doc, name) {
  return doc.createElement(name);
}

function domCreateAttribute(doc, name) {
  return doc.createAttribute(name);
}

function domCreateCDATASection(doc, data) {
  return doc.createCDATASection(data);
}

function domCreateComment(doc, text) {
  return doc.createComment(text);
}

function domCreateDocumentFragment(doc) {
  return doc.createDocumentFragment();
}

function domGetElementById(doc, id) {
  return doc.getElementById(id);
}

// Same for window methods.
function windowSetInterval(win, fun, time) {
  return win.setInterval(fun, time);
}

function windowClearInterval(win, id) {
  return win.clearInterval(id);
}

// Copyright 2006 Google Inc.
// All Rights Reserved
//
// Defines regular expression patterns to extract XML tokens from string.
// See <http://www.w3.org/TR/REC-xml/#sec-common-syn>,
// <http://www.w3.org/TR/xml11/#sec-common-syn> and
// <http://www.w3.org/TR/REC-xml-names/#NT-NCName> for the specifications.
//
// Author: Junji Takagi <jtakagi@google.com>

// Detect whether RegExp supports Unicode characters or not.

var REGEXP_UNICODE = function() {
  var tests = [' ', '\u0120', -1,  // Konquerer 3.4.0 fails here.
               '!', '\u0120', -1,
               '\u0120', '\u0120', 0,
               '\u0121', '\u0120', -1,
               '\u0121', '\u0120|\u0121', 0,
               '\u0122', '\u0120|\u0121', -1,
               '\u0120', '[\u0120]', 0,  // Safari 2.0.3 fails here.
               '\u0121', '[\u0120]', -1,
               '\u0121', '[\u0120\u0121]', 0,  // Safari 2.0.3 fails here.
               '\u0122', '[\u0120\u0121]', -1,
               '\u0121', '[\u0120-\u0121]', 0,  // Safari 2.0.3 fails here.
               '\u0122', '[\u0120-\u0121]', -1];
  for (var i = 0; i < tests.length; i += 3) {
    if (tests[i].search(new RegExp(tests[i + 1])) != tests[i + 2]) {
      return false;
    }
  }
  return true;
}();

// Common tokens in XML 1.0 and XML 1.1.

var XML_S = '[ \t\r\n]+';
var XML_EQ = '(' + XML_S + ')?=(' + XML_S + ')?';
var XML_CHAR_REF = '&#[0-9]+;|&#x[0-9a-fA-F]+;';

// XML 1.0 tokens.

var XML10_VERSION_INFO = XML_S + 'version' + XML_EQ + '("1\\.0"|' + "'1\\.0')";
var XML10_BASE_CHAR = (REGEXP_UNICODE) ?
  '\u0041-\u005a\u0061-\u007a\u00c0-\u00d6\u00d8-\u00f6\u00f8-\u00ff' +
  '\u0100-\u0131\u0134-\u013e\u0141-\u0148\u014a-\u017e\u0180-\u01c3' +
  '\u01cd-\u01f0\u01f4-\u01f5\u01fa-\u0217\u0250-\u02a8\u02bb-\u02c1\u0386' +
  '\u0388-\u038a\u038c\u038e-\u03a1\u03a3-\u03ce\u03d0-\u03d6\u03da\u03dc' +
  '\u03de\u03e0\u03e2-\u03f3\u0401-\u040c\u040e-\u044f\u0451-\u045c' +
  '\u045e-\u0481\u0490-\u04c4\u04c7-\u04c8\u04cb-\u04cc\u04d0-\u04eb' +
  '\u04ee-\u04f5\u04f8-\u04f9\u0531-\u0556\u0559\u0561-\u0586\u05d0-\u05ea' +
  '\u05f0-\u05f2\u0621-\u063a\u0641-\u064a\u0671-\u06b7\u06ba-\u06be' +
  '\u06c0-\u06ce\u06d0-\u06d3\u06d5\u06e5-\u06e6\u0905-\u0939\u093d' +
  '\u0958-\u0961\u0985-\u098c\u098f-\u0990\u0993-\u09a8\u09aa-\u09b0\u09b2' +
  '\u09b6-\u09b9\u09dc-\u09dd\u09df-\u09e1\u09f0-\u09f1\u0a05-\u0a0a' +
  '\u0a0f-\u0a10\u0a13-\u0a28\u0a2a-\u0a30\u0a32-\u0a33\u0a35-\u0a36' +
  '\u0a38-\u0a39\u0a59-\u0a5c\u0a5e\u0a72-\u0a74\u0a85-\u0a8b\u0a8d' +
  '\u0a8f-\u0a91\u0a93-\u0aa8\u0aaa-\u0ab0\u0ab2-\u0ab3\u0ab5-\u0ab9' +
  '\u0abd\u0ae0\u0b05-\u0b0c\u0b0f-\u0b10\u0b13-\u0b28\u0b2a-\u0b30' +
  '\u0b32-\u0b33\u0b36-\u0b39\u0b3d\u0b5c-\u0b5d\u0b5f-\u0b61\u0b85-\u0b8a' +
  '\u0b8e-\u0b90\u0b92-\u0b95\u0b99-\u0b9a\u0b9c\u0b9e-\u0b9f\u0ba3-\u0ba4' +
  '\u0ba8-\u0baa\u0bae-\u0bb5\u0bb7-\u0bb9\u0c05-\u0c0c\u0c0e-\u0c10' +
  '\u0c12-\u0c28\u0c2a-\u0c33\u0c35-\u0c39\u0c60-\u0c61\u0c85-\u0c8c' +
  '\u0c8e-\u0c90\u0c92-\u0ca8\u0caa-\u0cb3\u0cb5-\u0cb9\u0cde\u0ce0-\u0ce1' +
  '\u0d05-\u0d0c\u0d0e-\u0d10\u0d12-\u0d28\u0d2a-\u0d39\u0d60-\u0d61' +
  '\u0e01-\u0e2e\u0e30\u0e32-\u0e33\u0e40-\u0e45\u0e81-\u0e82\u0e84' +
  '\u0e87-\u0e88\u0e8a\u0e8d\u0e94-\u0e97\u0e99-\u0e9f\u0ea1-\u0ea3\u0ea5' +
  '\u0ea7\u0eaa-\u0eab\u0ead-\u0eae\u0eb0\u0eb2-\u0eb3\u0ebd\u0ec0-\u0ec4' +
  '\u0f40-\u0f47\u0f49-\u0f69\u10a0-\u10c5\u10d0-\u10f6\u1100\u1102-\u1103' +
  '\u1105-\u1107\u1109\u110b-\u110c\u110e-\u1112\u113c\u113e\u1140\u114c' +
  '\u114e\u1150\u1154-\u1155\u1159\u115f-\u1161\u1163\u1165\u1167\u1169' +
  '\u116d-\u116e\u1172-\u1173\u1175\u119e\u11a8\u11ab\u11ae-\u11af' +
  '\u11b7-\u11b8\u11ba\u11bc-\u11c2\u11eb\u11f0\u11f9\u1e00-\u1e9b' +
  '\u1ea0-\u1ef9\u1f00-\u1f15\u1f18-\u1f1d\u1f20-\u1f45\u1f48-\u1f4d' +
  '\u1f50-\u1f57\u1f59\u1f5b\u1f5d\u1f5f-\u1f7d\u1f80-\u1fb4\u1fb6-\u1fbc' +
  '\u1fbe\u1fc2-\u1fc4\u1fc6-\u1fcc\u1fd0-\u1fd3\u1fd6-\u1fdb\u1fe0-\u1fec' +
  '\u1ff2-\u1ff4\u1ff6-\u1ffc\u2126\u212a-\u212b\u212e\u2180-\u2182' +
  '\u3041-\u3094\u30a1-\u30fa\u3105-\u312c\uac00-\ud7a3' :
  'A-Za-z';
var XML10_IDEOGRAPHIC = (REGEXP_UNICODE) ?
  '\u4e00-\u9fa5\u3007\u3021-\u3029' :
  '';
var XML10_COMBINING_CHAR = (REGEXP_UNICODE) ?
  '\u0300-\u0345\u0360-\u0361\u0483-\u0486\u0591-\u05a1\u05a3-\u05b9' +
  '\u05bb-\u05bd\u05bf\u05c1-\u05c2\u05c4\u064b-\u0652\u0670\u06d6-\u06dc' +
  '\u06dd-\u06df\u06e0-\u06e4\u06e7-\u06e8\u06ea-\u06ed\u0901-\u0903\u093c' +
  '\u093e-\u094c\u094d\u0951-\u0954\u0962-\u0963\u0981-\u0983\u09bc\u09be' +
  '\u09bf\u09c0-\u09c4\u09c7-\u09c8\u09cb-\u09cd\u09d7\u09e2-\u09e3\u0a02' +
  '\u0a3c\u0a3e\u0a3f\u0a40-\u0a42\u0a47-\u0a48\u0a4b-\u0a4d\u0a70-\u0a71' +
  '\u0a81-\u0a83\u0abc\u0abe-\u0ac5\u0ac7-\u0ac9\u0acb-\u0acd\u0b01-\u0b03' +
  '\u0b3c\u0b3e-\u0b43\u0b47-\u0b48\u0b4b-\u0b4d\u0b56-\u0b57\u0b82-\u0b83' +
  '\u0bbe-\u0bc2\u0bc6-\u0bc8\u0bca-\u0bcd\u0bd7\u0c01-\u0c03\u0c3e-\u0c44' +
  '\u0c46-\u0c48\u0c4a-\u0c4d\u0c55-\u0c56\u0c82-\u0c83\u0cbe-\u0cc4' +
  '\u0cc6-\u0cc8\u0cca-\u0ccd\u0cd5-\u0cd6\u0d02-\u0d03\u0d3e-\u0d43' +
  '\u0d46-\u0d48\u0d4a-\u0d4d\u0d57\u0e31\u0e34-\u0e3a\u0e47-\u0e4e\u0eb1' +
  '\u0eb4-\u0eb9\u0ebb-\u0ebc\u0ec8-\u0ecd\u0f18-\u0f19\u0f35\u0f37\u0f39' +
  '\u0f3e\u0f3f\u0f71-\u0f84\u0f86-\u0f8b\u0f90-\u0f95\u0f97\u0f99-\u0fad' +
  '\u0fb1-\u0fb7\u0fb9\u20d0-\u20dc\u20e1\u302a-\u302f\u3099\u309a' :
  '';
var XML10_DIGIT = (REGEXP_UNICODE) ?
  '\u0030-\u0039\u0660-\u0669\u06f0-\u06f9\u0966-\u096f\u09e6-\u09ef' +
  '\u0a66-\u0a6f\u0ae6-\u0aef\u0b66-\u0b6f\u0be7-\u0bef\u0c66-\u0c6f' +
  '\u0ce6-\u0cef\u0d66-\u0d6f\u0e50-\u0e59\u0ed0-\u0ed9\u0f20-\u0f29' :
  '0-9';
var XML10_EXTENDER = (REGEXP_UNICODE) ?
  '\u00b7\u02d0\u02d1\u0387\u0640\u0e46\u0ec6\u3005\u3031-\u3035' +
  '\u309d-\u309e\u30fc-\u30fe' :
  '';
var XML10_LETTER = XML10_BASE_CHAR + XML10_IDEOGRAPHIC;
var XML10_NAME_CHAR = XML10_LETTER + XML10_DIGIT + '\\._:' +
                      XML10_COMBINING_CHAR + XML10_EXTENDER + '-';
var XML10_NAME = '[' + XML10_LETTER + '_:][' + XML10_NAME_CHAR + ']*';

var XML10_ENTITY_REF = '&' + XML10_NAME + ';';
var XML10_REFERENCE = XML10_ENTITY_REF + '|' + XML_CHAR_REF;
var XML10_ATT_VALUE = '"(([^<&"]|' + XML10_REFERENCE + ')*)"|' +
                      "'(([^<&']|" + XML10_REFERENCE + ")*)'";
var XML10_ATTRIBUTE =
  '(' + XML10_NAME + ')' + XML_EQ + '(' + XML10_ATT_VALUE + ')';

// XML 1.1 tokens.
// TODO(jtakagi): NameStartChar also includes \u10000-\ueffff.
// ECMAScript Language Specifiction defines UnicodeEscapeSequence as
// "\u HexDigit HexDigit HexDigit HexDigit" and we may need to use
// surrogate pairs, but any browser doesn't support surrogate paris in
// character classes of regular expression, so avoid including them for now.

var XML11_VERSION_INFO = XML_S + 'version' + XML_EQ + '("1\\.1"|' + "'1\\.1')";
var XML11_NAME_START_CHAR = (REGEXP_UNICODE) ?
  ':A-Z_a-z\u00c0-\u00d6\u00d8-\u00f6\u00f8-\u02ff\u0370-\u037d' +
  '\u037f-\u1fff\u200c-\u200d\u2070-\u218f\u2c00-\u2fef\u3001-\ud7ff' +
  '\uf900-\ufdcf\ufdf0-\ufffd' :
  ':A-Z_a-z';
var XML11_NAME_CHAR = XML11_NAME_START_CHAR +
  ((REGEXP_UNICODE) ? '\\.0-9\u00b7\u0300-\u036f\u203f-\u2040-' : '\\.0-9-');
var XML11_NAME = '[' + XML11_NAME_START_CHAR + '][' + XML11_NAME_CHAR + ']*';

var XML11_ENTITY_REF = '&' + XML11_NAME + ';';
var XML11_REFERENCE = XML11_ENTITY_REF + '|' + XML_CHAR_REF;
var XML11_ATT_VALUE = '"(([^<&"]|' + XML11_REFERENCE + ')*)"|' +
                      "'(([^<&']|" + XML11_REFERENCE + ")*)'";
var XML11_ATTRIBUTE =
  '(' + XML11_NAME + ')' + XML_EQ + '(' + XML11_ATT_VALUE + ')';

// XML Namespace tokens.
// Used in XML parser and XPath parser.

var XML_NC_NAME_CHAR = XML10_LETTER + XML10_DIGIT + '\\._' +
                       XML10_COMBINING_CHAR + XML10_EXTENDER + '-';
var XML_NC_NAME = '[' + XML10_LETTER + '_][' + XML_NC_NAME_CHAR + ']*';

// Copyright 2005 Google Inc.
// All Rights Reserved
//
// Author: Steffen Meschkat <mesch@google.com>
//
// An XML parse and a minimal DOM implementation that just supportes
// the subset of the W3C DOM that is used in the XSLT implementation.

// NOTE: The split() method in IE omits empty result strings. This is
// utterly annoying. So we don't use it here.

// Resolve entities in XML text fragments. According to the DOM
// specification, the DOM is supposed to resolve entity references at
// the API level. I.e. no entity references are passed through the
// API. See "Entities and the DOM core", p.12, DOM 2 Core
// Spec. However, different browsers actually pass very different
// values at the API. See <http://mesch.nyc/test-xml-quote>.
function xmlResolveEntities(s) {

  var parts = stringSplit(s, '&');

  var ret = parts[0];
  for (var i = 1; i < parts.length; ++i) {
    var rp = parts[i].indexOf(';');
    if (rp == -1) {
      // no entity reference: just a & but no ;
      ret += parts[i];
      continue;
    }

    var entityName = parts[i].substring(0, rp);
    var remainderText = parts[i].substring(rp + 1);

    var ch;
    switch (entityName) {
      case 'lt':
        ch = '<';
        break;
      case 'gt':
        ch = '>';
        break;
      case 'amp':
        ch = '&';
        break;
      case 'quot':
        ch = '"';
        break;
      case 'apos':
        ch = '\'';
        break;
      case 'nbsp':
        ch = String.fromCharCode(160);
        break;
      default:
        // Cool trick: let the DOM do the entity decoding. We assign
        // the entity text through non-W3C DOM properties and read it
        // through the W3C DOM. W3C DOM access is specified to resolve
        // entities.
        var span = domCreateElement(window.document, 'span');
        span.innerHTML = '&' + entityName + '; ';
        ch = span.childNodes[0].nodeValue.charAt(0);
    }
    ret += ch + remainderText;
  }

  return ret;
}

var XML10_TAGNAME_REGEXP = new RegExp('^(' + XML10_NAME + ')');
var XML10_ATTRIBUTE_REGEXP = new RegExp(XML10_ATTRIBUTE, 'g');

var XML11_TAGNAME_REGEXP = new RegExp('^(' + XML11_NAME + ')');
var XML11_ATTRIBUTE_REGEXP = new RegExp(XML11_ATTRIBUTE, 'g');

// Parses the given XML string with our custom, JavaScript XML parser. Written
// by Steffen Meschkat (mesch@google.com).
function xmlParse(xml) {
  var regex_empty = /\/$/;

  var regex_tagname;
  var regex_attribute;
  if (xml.match(/^<\?xml/)) {
    // When an XML document begins with an XML declaration
    // VersionInfo must appear.
    if (xml.search(new RegExp(XML10_VERSION_INFO)) == 5) {
      regex_tagname = XML10_TAGNAME_REGEXP;
      regex_attribute = XML10_ATTRIBUTE_REGEXP;
    } else if (xml.search(new RegExp(XML11_VERSION_INFO)) == 5) {
      regex_tagname = XML11_TAGNAME_REGEXP;
      regex_attribute = XML11_ATTRIBUTE_REGEXP;
    } else {
      // VersionInfo is missing, or unknown version number.
      // TODO : Fallback to XML 1.0 or XML 1.1, or just return null?
      alert('VersionInfo is missing, or unknown version number.');
    }
  } else {
    // When an XML declaration is missing it's an XML 1.0 document.
    regex_tagname = XML10_TAGNAME_REGEXP;
    regex_attribute = XML10_ATTRIBUTE_REGEXP;
  }

  var xmldoc = new XDocument();
  var root = xmldoc;

  // For the record: in Safari, we would create native DOM nodes, but
  // in Opera that is not possible, because the DOM only allows HTML
  // element nodes to be created, so we have to do our own DOM nodes.

  // xmldoc = document.implementation.createDocument('','',null);
  // root = xmldoc; // .createDocumentFragment();
  // NOTE(mesch): using the DocumentFragment instead of the Document
  // crashes my Safari 1.2.4 (v125.12).
  var stack = [];

  var parent = root;
  stack.push(parent);

  // The token that delimits a section that contains markup as
  // content: CDATA or comments.
  var slurp = '';

  var x = stringSplit(xml, '<');
  for (var i = 1; i < x.length; ++i) {
    var xx = stringSplit(x[i], '>');
    var tag = xx[0];
    var text = xmlResolveEntities(xx[1] || '');

    if (slurp) {
      // In a "slurp" section (CDATA or comment): only check for the
      // end of the section, otherwise append the whole text.
      var end = x[i].indexOf(slurp);
      if (end != -1) {
        var data = x[i].substring(0, end);
        parent.nodeValue += '<' + data;
        stack.pop();
        parent = stack[stack.length-1];
        text = x[i].substring(end + slurp.length);
        slurp = '';
      } else {
        parent.nodeValue += '<' + x[i];
        text = null;
      }

    } else if (tag.indexOf('![CDATA[') == 0) {
      var start = '![CDATA['.length;
      var end = x[i].indexOf(']]>');
      if (end != -1) {
        var data = x[i].substring(start, end);
        var node = domCreateCDATASection(xmldoc, data);
        domAppendChild(parent, node);
      } else {
        var data = x[i].substring(start);
        text = null;
        var node = domCreateCDATASection(xmldoc, data);
        domAppendChild(parent, node);
        parent = node;
        stack.push(node);
        slurp = ']]>';
      }

    } else if (tag.indexOf('!--') == 0) {
      var start = '!--'.length;
      var end = x[i].indexOf('-->');
      if (end != -1) {
        var data = x[i].substring(start, end);
        var node = domCreateComment(xmldoc, data);
        domAppendChild(parent, node);
      } else {
        var data = x[i].substring(start);
        text = null;
        var node = domCreateComment(xmldoc, data);
        domAppendChild(parent, node);
        parent = node;
        stack.push(node);
        slurp = '-->';
      }

    } else if (tag.charAt(0) == '/') {
      stack.pop();
      parent = stack[stack.length-1];

    } else if (tag.charAt(0) == '?') {
      // Ignore XML declaration and processing instructions
    } else if (tag.charAt(0) == '!') {
      // Ignore notation and comments
    } else {
      var empty = tag.match(regex_empty);
      var tagname = regex_tagname.exec(tag)[1];
      var node = domCreateElement(xmldoc, tagname);

      var att;
      while (att = regex_attribute.exec(tag)) {
        var val = xmlResolveEntities(att[5] || att[7] || '');
        domSetAttribute(node, att[1], val);
      }

      domAppendChild(parent, node);
      if (!empty) {
        parent = node;
        stack.push(node);
      }
    }

    if (text && parent != root) {
      domAppendChild(parent, domCreateTextNode(xmldoc, text));
    }
  }

  return root;
}

// Based on <http://www.w3.org/TR/2000/REC-DOM-Level-2-Core-20001113/
// core.html#ID-1950641247>
var DOM_ELEMENT_NODE = 1;
var DOM_ATTRIBUTE_NODE = 2;
var DOM_TEXT_NODE = 3;
var DOM_CDATA_SECTION_NODE = 4;
var DOM_ENTITY_REFERENCE_NODE = 5;
var DOM_ENTITY_NODE = 6;
var DOM_PROCESSING_INSTRUCTION_NODE = 7;
var DOM_COMMENT_NODE = 8;
var DOM_DOCUMENT_NODE = 9;
var DOM_DOCUMENT_TYPE_NODE = 10;
var DOM_DOCUMENT_FRAGMENT_NODE = 11;
var DOM_NOTATION_NODE = 12;

// Traverses the element nodes in the DOM section underneath the given
// node and invokes the given callbacks as methods on every element
// node encountered. Function opt_pre is invoked before a node's
// children are traversed; opt_post is invoked after they are
// traversed. Traversal will not be continued if a callback function
// returns boolean false. NOTE(mesch): copied from
// <//google3/maps/webmaps/javascript/dom.js>.
function domTraverseElements(node, opt_pre, opt_post) {
  var ret;
  if (opt_pre) {
    ret = opt_pre.call(null, node);
    if (typeof ret == 'boolean' && !ret) {
      return false;
    }
  }

  for (var c = node.firstChild; c; c = c.nextSibling) {
    if (c.nodeType == DOM_ELEMENT_NODE) {
      ret = arguments.callee.call(this, c, opt_pre, opt_post);
      if (typeof ret == 'boolean' && !ret) {
        return false;
      }
    }
  }

  if (opt_post) {
    ret = opt_post.call(null, node);
    if (typeof ret == 'boolean' && !ret) {
      return false;
    }
  }
}

// Our W3C DOM Node implementation. Note we call it XNode because we
// can't define the identifier Node. We do this mostly for Opera,
// where we can't reuse the HTML DOM for parsing our own XML, and for
// Safari, where it is too expensive to have the template processor
// operate on native DOM nodes.
function XNode(type, name, opt_value, opt_owner) {
  this.attributes = [];
  this.childNodes = [];

  XNode.init.call(this, type, name, opt_value, opt_owner);
}

// Don't call as method, use apply() or call().
XNode.init = function(type, name, value, owner) {
  this.nodeType = type - 0;
  this.nodeName = '' + name;
  this.nodeValue = '' + value;
  this.ownerDocument = owner;

  this.firstChild = null;
  this.lastChild = null;
  this.nextSibling = null;
  this.previousSibling = null;
  this.parentNode = null;
}

XNode.unused_ = [];

XNode.recycle = function(node) {
  if (!node) {
    return;
  }

  if (node.constructor == XDocument) {
    XNode.recycle(node.documentElement);
    return;
  }

  if (node.constructor != this) {
    return;
  }

  XNode.unused_.push(node);
  for (var a = 0; a < node.attributes.length; ++a) {
    XNode.recycle(node.attributes[a]);
  }
  for (var c = 0; c < node.childNodes.length; ++c) {
    XNode.recycle(node.childNodes[c]);
  }
  node.attributes.length = 0;
  node.childNodes.length = 0;
  XNode.init.call(node, 0, '', '', null);
}

XNode.create = function(type, name, value, owner) {
  if (XNode.unused_.length > 0) {
    var node = XNode.unused_.pop();
    XNode.init.call(node, type, name, value, owner);
    return node;
  } else {
    return new XNode(type, name, value, owner);
  }
}

XNode.prototype.appendChild = function(node) {
  // firstChild
  if (this.childNodes.length == 0) {
    this.firstChild = node;
  }

  // previousSibling
  node.previousSibling = this.lastChild;

  // nextSibling
  node.nextSibling = null;
  if (this.lastChild) {
    this.lastChild.nextSibling = node;
  }

  // parentNode
  node.parentNode = this;

  // lastChild
  this.lastChild = node;

  // childNodes
  this.childNodes.push(node);
}


XNode.prototype.replaceChild = function(newNode, oldNode) {
  if (oldNode == newNode) {
    return;
  }

  for (var i = 0; i < this.childNodes.length; ++i) {
    if (this.childNodes[i] == oldNode) {
      this.childNodes[i] = newNode;

      var p = oldNode.parentNode;
      oldNode.parentNode = null;
      newNode.parentNode = p;

      p = oldNode.previousSibling;
      oldNode.previousSibling = null;
      newNode.previousSibling = p;
      if (newNode.previousSibling) {
        newNode.previousSibling.nextSibling = newNode;
      }

      p = oldNode.nextSibling;
      oldNode.nextSibling = null;
      newNode.nextSibling = p;
      if (newNode.nextSibling) {
        newNode.nextSibling.previousSibling = newNode;
      }

      if (this.firstChild == oldNode) {
        this.firstChild = newNode;
      }

      if (this.lastChild == oldNode) {
        this.lastChild = newNode;
      }

      break;
    }
  }
}


XNode.prototype.insertBefore = function(newNode, oldNode) {
  if (oldNode == newNode) {
    return;
  }

  if (oldNode.parentNode != this) {
    return;
  }

  if (newNode.parentNode) {
    newNode.parentNode.removeChild(newNode);
  }

  var newChildren = [];
  for (var i = 0; i < this.childNodes.length; ++i) {
    var c = this.childNodes[i];
    if (c == oldNode) {
      newChildren.push(newNode);

      newNode.parentNode = this;

      newNode.previousSibling = oldNode.previousSibling;
      oldNode.previousSibling = newNode;
      if (newNode.previousSibling) {
        newNode.previousSibling.nextSibling = newNode;
      }

      newNode.nextSibling = oldNode;

      if (this.firstChild == oldNode) {
        this.firstChild = newNode;
      }
    }
    newChildren.push(c);
  }
  this.childNodes = newChildren;
}


XNode.prototype.removeChild = function(node) {
  var newChildren = [];
  for (var i = 0; i < this.childNodes.length; ++i) {
    var c = this.childNodes[i];
    if (c != node) {
      newChildren.push(c);
    } else {
      if (c.previousSibling) {
        c.previousSibling.nextSibling = c.nextSibling;
      }
      if (c.nextSibling) {
        c.nextSibling.previousSibling = c.previousSibling;
      }
      if (this.firstChild == c) {
        this.firstChild = c.nextSibling;
      }
      if (this.lastChild == c) {
        this.lastChild = c.previousSibling;
      }
    }
  }
  this.childNodes = newChildren;
}


XNode.prototype.hasAttributes = function() {
  return this.attributes.length > 0;
}


XNode.prototype.setAttribute = function(name, value) {
  for (var i = 0; i < this.attributes.length; ++i) {
    if (this.attributes[i].nodeName == name) {
      this.attributes[i].nodeValue = '' + value;
      return;
    }
  }
  this.attributes.push(XNode.create(DOM_ATTRIBUTE_NODE, name, value, this));
}


XNode.prototype.getAttribute = function(name) {
  for (var i = 0; i < this.attributes.length; ++i) {
    if (this.attributes[i].nodeName == name) {
      return this.attributes[i].nodeValue;
    }
  }
  return null;
}


XNode.prototype.removeAttribute = function(name) {
  var a = [];
  for (var i = 0; i < this.attributes.length; ++i) {
    if (this.attributes[i].nodeName != name) {
      a.push(this.attributes[i]);
    }
  }
  this.attributes = a;
}


XNode.prototype.getElementsByTagName = function(name) {
  var ret = [];
  domTraverseElements(this, function(node) {
    if (node.nodeName == name) {
      ret.push(node);
    }
  }, null);
  return ret;
}


XNode.prototype.getElementById = function(id) {
  var ret = null;
  domTraverseElements(this, function(node) {
    if (node.getAttribute('id') == id) {
      ret = node;
      return false;
    }
  }, null);
  return ret;
}


function XDocument() {
  // NOTE(mesch): Acocording to the DOM Spec, ownerDocument of a
  // document node is null.
  XNode.call(this, DOM_DOCUMENT_NODE, '#document', null, null);
  this.documentElement = null;
}

XDocument.prototype = new XNode(DOM_DOCUMENT_NODE, '#document');

XDocument.prototype.clear = function() {
  XNode.recycle(this.documentElement);
  this.documentElement = null;
}

XDocument.prototype.appendChild = function(node) {
  XNode.prototype.appendChild.call(this, node);
  this.documentElement = this.childNodes[0];
}

XDocument.prototype.createElement = function(name) {
  return XNode.create(DOM_ELEMENT_NODE, name, null, this);
}

XDocument.prototype.createDocumentFragment = function() {
  return XNode.create(DOM_DOCUMENT_FRAGMENT_NODE, '#document-fragment',
                    null, this);
}

XDocument.prototype.createTextNode = function(value) {
  return XNode.create(DOM_TEXT_NODE, '#text', value, this);
}

XDocument.prototype.createAttribute = function(name) {
  return XNode.create(DOM_ATTRIBUTE_NODE, name, null, this);
}

XDocument.prototype.createComment = function(data) {
  return XNode.create(DOM_COMMENT_NODE, '#comment', data, this);
}

XDocument.prototype.createCDATASection = function(data) {
  return XNode.create(DOM_CDATA_SECTION_NODE, '#cdata-section', data, this);
}

// Copyright 2005 Google Inc.
// All Rights Reserved
//
// An XPath parser and evaluator written in JavaScript. The
// implementation is complete except for functions handling
// namespaces.
//
// Reference: [XPATH] XPath Specification
// <http://www.w3.org/TR/1999/REC-xpath-19991116>.
//
//
// The API of the parser has several parts:
//
// 1. The parser function xpathParse() that takes a string and returns
// an expession object.
//
// 2. The expression object that has an evaluate() method to evaluate the
// XPath expression it represents. (It is actually a hierarchy of
// objects that resembles the parse tree, but an application will call
// evaluate() only on the top node of this hierarchy.)
//
// 3. The context object that is passed as an argument to the evaluate()
// method, which represents the DOM context in which the expression is
// evaluated.
//
// 4. The value object that is returned from evaluate() and represents
// values of the different types that are defined by XPath (number,
// string, boolean, and node-set), and allows to convert between them.
//
// These parts are near the top of the file, the functions and data
// that are used internally follow after them.
//
//
// Author: Steffen Meschkat <mesch@google.com>


// The entry point for the parser.
//
// @param expr a string that contains an XPath expression.
// @return an expression object that can be evaluated with an
// expression context.

function xpathParse(expr) {
  xpathLog('parse ' + expr);
  xpathParseInit();

  var cached = xpathCacheLookup(expr);
  if (cached) {
    xpathLog(' ... cached');
    return cached;
  }

  // Optimize for a few common cases: simple attribute node tests
  // (@id), simple element node tests (page), variable references
  // ($address), numbers (4), multi-step path expressions where each
  // step is a plain element node test
  // (page/overlay/locations/location).

  if (expr.match(/^(\$|@)?\w+$/i)) {
    var ret = makeSimpleExpr(expr);
    xpathParseCache[expr] = ret;
    xpathLog(' ... simple');
    return ret;
  }

  if (expr.match(/^\w+(\/\w+)*$/i)) {
    var ret = makeSimpleExpr2(expr);
    xpathParseCache[expr] = ret;
    xpathLog(' ... simple 2');
    return ret;
  }

  var cachekey = expr; // expr is modified during parse

  var stack = [];
  var ahead = null;
  var previous = null;
  var done = false;

  var parse_count = 0;
  var lexer_count = 0;
  var reduce_count = 0;

  while (!done) {
    parse_count++;
    expr = expr.replace(/^\s*/, '');
    previous = ahead;
    ahead = null;

    var rule = null;
    var match = '';
    for (var i = 0; i < xpathTokenRules.length; ++i) {
      var result = xpathTokenRules[i].re.exec(expr);
      lexer_count++;
      if (result && result.length > 0 && result[0].length > match.length) {
        rule = xpathTokenRules[i];
        match = result[0];
        break;
      }
    }

    // Special case: allow operator keywords to be element and
    // variable names.

    // NOTE(mesch): The parser resolves conflicts by looking ahead,
    // and this is the only case where we look back to
    // disambiguate. So this is indeed something different, and
    // looking back is usually done in the lexer (via states in the
    // general case, called "start conditions" in flex(1)). Also,the
    // conflict resolution in the parser is not as robust as it could
    // be, so I'd like to keep as much off the parser as possible (all
    // these precedence values should be computed from the grammar
    // rules and possibly associativity declarations, as in bison(1),
    // and not explicitly set.

    if (rule &&
        (rule == TOK_DIV ||
         rule == TOK_MOD ||
         rule == TOK_AND ||
         rule == TOK_OR) &&
        (!previous ||
         previous.tag == TOK_AT ||
         previous.tag == TOK_DSLASH ||
         previous.tag == TOK_SLASH ||
         previous.tag == TOK_AXIS ||
         previous.tag == TOK_DOLLAR)) {
      rule = TOK_QNAME;
    }

    if (rule) {
      expr = expr.substr(match.length);
      xpathLog('token: ' + match + ' -- ' + rule.label);
      ahead = {
        tag: rule,
        match: match,
        prec: rule.prec ?  rule.prec : 0, // || 0 is removed by the compiler
        expr: makeTokenExpr(match)
      };

    } else {
      xpathLog('DONE');
      done = true;
    }

    while (xpathReduce(stack, ahead)) {
      reduce_count++;
      xpathLog('stack: ' + stackToString(stack));
    }
  }

  xpathLog('stack: ' + stackToString(stack));

  if (stack.length != 1) {
    throw 'XPath parse error ' + cachekey + ':\n' + stackToString(stack);
  }

  var result = stack[0].expr;
  xpathParseCache[cachekey] = result;

  xpathLog('XPath parse: ' + parse_count + ' / ' +
           lexer_count + ' / ' + reduce_count);

  return result;
}

var xpathParseCache = {};

function xpathCacheLookup(expr) {
  return xpathParseCache[expr];
}

function xpathReduce(stack, ahead) {
  var cand = null;

  if (stack.length > 0) {
    var top = stack[stack.length-1];
    var ruleset = xpathRules[top.tag.key];

    if (ruleset) {
      for (var i = 0; i < ruleset.length; ++i) {
        var rule = ruleset[i];
        var match = xpathMatchStack(stack, rule[1]);
        if (match.length) {
          cand = {
            tag: rule[0],
            rule: rule,
            match: match
          };
          cand.prec = xpathGrammarPrecedence(cand);
          break;
        }
      }
    }
  }

  var ret;
  if (cand && (!ahead || cand.prec > ahead.prec ||
               (ahead.tag.left && cand.prec >= ahead.prec))) {
    for (var i = 0; i < cand.match.matchlength; ++i) {
      stack.pop();
    }

    xpathLog('reduce ' + cand.tag.label + ' ' + cand.prec +
             ' ahead ' + (ahead ? ahead.tag.label + ' ' + ahead.prec +
                          (ahead.tag.left ? ' left' : '')
                          : ' none '));

    var matchexpr = mapExpr(cand.match, function(m) { return m.expr; });
    cand.expr = cand.rule[3].apply(null, matchexpr);

    stack.push(cand);
    ret = true;

  } else {
    if (ahead) {
      xpathLog('shift ' + ahead.tag.label + ' ' + ahead.prec +
               (ahead.tag.left ? ' left' : '') +
               ' over ' + (cand ? cand.tag.label + ' ' +
                           cand.prec : ' none'));
      stack.push(ahead);
    }
    ret = false;
  }
  return ret;
}

function xpathMatchStack(stack, pattern) {

  // NOTE(mesch): The stack matches for variable cardinality are
  // greedy but don't do backtracking. This would be an issue only
  // with rules of the form A* A, i.e. with an element with variable
  // cardinality followed by the same element. Since that doesn't
  // occur in the grammar at hand, all matches on the stack are
  // unambiguous.

  var S = stack.length;
  var P = pattern.length;
  var p, s;
  var match = [];
  match.matchlength = 0;
  var ds = 0;
  for (p = P - 1, s = S - 1; p >= 0 && s >= 0; --p, s -= ds) {
    ds = 0;
    var qmatch = [];
    if (pattern[p] == Q_MM) {
      p -= 1;
      match.push(qmatch);
      while (s - ds >= 0 && stack[s - ds].tag == pattern[p]) {
        qmatch.push(stack[s - ds]);
        ds += 1;
        match.matchlength += 1;
      }

    } else if (pattern[p] == Q_01) {
      p -= 1;
      match.push(qmatch);
      while (s - ds >= 0 && ds < 2 && stack[s - ds].tag == pattern[p]) {
        qmatch.push(stack[s - ds]);
        ds += 1;
        match.matchlength += 1;
      }

    } else if (pattern[p] == Q_1M) {
      p -= 1;
      match.push(qmatch);
      if (stack[s].tag == pattern[p]) {
        while (s - ds >= 0 && stack[s - ds].tag == pattern[p]) {
          qmatch.push(stack[s - ds]);
          ds += 1;
          match.matchlength += 1;
        }
      } else {
        return [];
      }

    } else if (stack[s].tag == pattern[p]) {
      match.push(stack[s]);
      ds += 1;
      match.matchlength += 1;

    } else {
      return [];
    }

    reverseInplace(qmatch);
    qmatch.expr = mapExpr(qmatch, function(m) { return m.expr; });
  }

  reverseInplace(match);

  if (p == -1) {
    return match;

  } else {
    return [];
  }
}

function xpathTokenPrecedence(tag) {
  return tag.prec || 2;
}

function xpathGrammarPrecedence(frame) {
  var ret = 0;

  if (frame.rule) { /* normal reduce */
    if (frame.rule.length >= 3 && frame.rule[2] >= 0) {
      ret = frame.rule[2];

    } else {
      for (var i = 0; i < frame.rule[1].length; ++i) {
        var p = xpathTokenPrecedence(frame.rule[1][i]);
        ret = Math.max(ret, p);
      }
    }
  } else if (frame.tag) { /* TOKEN match */
    ret = xpathTokenPrecedence(frame.tag);

  } else if (frame.length) { /* Q_ match */
    for (var j = 0; j < frame.length; ++j) {
      var p = xpathGrammarPrecedence(frame[j]);
      ret = Math.max(ret, p);
    }
  }

  return ret;
}

function stackToString(stack) {
  var ret = '';
  for (var i = 0; i < stack.length; ++i) {
    if (ret) {
      ret += '\n';
    }
    ret += stack[i].tag.label;
  }
  return ret;
}


// XPath expression evaluation context. An XPath context consists of a
// DOM node, a list of DOM nodes that contains this node, a number
// that represents the position of the single node in the list, and a
// current set of variable bindings. (See XPath spec.)
//
// The interface of the expression context:
//
//   Constructor -- gets the node, its position, the node set it
//   belongs to, and a parent context as arguments. The parent context
//   is used to implement scoping rules for variables: if a variable
//   is not found in the current context, it is looked for in the
//   parent context, recursively. Except for node, all arguments have
//   default values: default position is 0, default node set is the
//   set that contains only the node, and the default parent is null.
//
//     Notice that position starts at 0 at the outside interface;
//     inside XPath expressions this shows up as position()=1.
//
//   clone() -- creates a new context with the current context as
//   parent. If passed as argument to clone(), the new context has a
//   different node, position, or node set. What is not passed is
//   inherited from the cloned context.
//
//   setVariable(name, expr) -- binds given XPath expression to the
//   name.
//
//   getVariable(name) -- what the name says.
//
//   setNode(position) -- sets the context to the node at the given
//   position. Needed to implement scoping rules for variables in
//   XPath. (A variable is visible to all subsequent siblings, not
//   only to its children.)

function ExprContext(node, opt_position, opt_nodelist, opt_parent) {
  this.node = node;
  this.position = opt_position || 0;
  this.nodelist = opt_nodelist || [ node ];
  this.variables = {};
  this.parent = opt_parent || null;
  if (opt_parent) {
    this.root = opt_parent.root;
  } else if (this.node.nodeType == DOM_DOCUMENT_NODE) {
    // NOTE(mesch): DOM Spec stipulates that the ownerDocument of a
    // document is null. Our root, however is the document that we are
    // processing, so the initial context is created from its document
    // node, which case we must handle here explcitly.
    this.root = node;
  } else {
    this.root = node.ownerDocument;
  }
}

ExprContext.prototype.clone = function(opt_node, opt_position, opt_nodelist) {
  return new ExprContext(
      opt_node || this.node,
      typeof opt_position != 'undefined' ? opt_position : this.position,
      opt_nodelist || this.nodelist, this);
};

ExprContext.prototype.setVariable = function(name, value) {
  this.variables[name] = value;
};

ExprContext.prototype.getVariable = function(name) {
  if (typeof this.variables[name] != 'undefined') {
    return this.variables[name];

  } else if (this.parent) {
    return this.parent.getVariable(name);

  } else {
    return null;
  }
};

ExprContext.prototype.setNode = function(position) {
  this.node = this.nodelist[position];
  this.position = position;
};

ExprContext.prototype.contextSize = function() {
  return this.nodelist.length;
};


// XPath expression values. They are what XPath expressions evaluate
// to. Strangely, the different value types are not specified in the
// XPath syntax, but only in the semantics, so they don't show up as
// nonterminals in the grammar. Yet, some expressions are required to
// evaluate to particular types, and not every type can be coerced
// into every other type. Although the types of XPath values are
// similar to the types present in JavaScript, the type coercion rules
// are a bit peculiar, so we explicitly model XPath types instead of
// mapping them onto JavaScript types. (See XPath spec.)
//
// The four types are:
//
//   StringValue
//
//   NumberValue
//
//   BooleanValue
//
//   NodeSetValue
//
// The common interface of the value classes consists of methods that
// implement the XPath type coercion rules:
//
//   stringValue() -- returns the value as a JavaScript String,
//
//   numberValue() -- returns the value as a JavaScript Number,
//
//   booleanValue() -- returns the value as a JavaScript Boolean,
//
//   nodeSetValue() -- returns the value as a JavaScript Array of DOM
//   Node objects.
//

function StringValue(value) {
  this.value = value;
  this.type = 'string';
}

StringValue.prototype.stringValue = function() {
  return this.value;
}

StringValue.prototype.booleanValue = function() {
  return this.value.length > 0;
}

StringValue.prototype.numberValue = function() {
  return this.value - 0;
}

StringValue.prototype.nodeSetValue = function() {
  throw this;
}

function BooleanValue(value) {
  this.value = value;
  this.type = 'boolean';
}

BooleanValue.prototype.stringValue = function() {
  return '' + this.value;
}

BooleanValue.prototype.booleanValue = function() {
  return this.value;
}

BooleanValue.prototype.numberValue = function() {
  return this.value ? 1 : 0;
}

BooleanValue.prototype.nodeSetValue = function() {
  throw this;
}

function NumberValue(value) {
  this.value = value;
  this.type = 'number';
}

NumberValue.prototype.stringValue = function() {
  return '' + this.value;
}

NumberValue.prototype.booleanValue = function() {
  return !!this.value;
}

NumberValue.prototype.numberValue = function() {
  return this.value - 0;
}

NumberValue.prototype.nodeSetValue = function() {
  throw this;
}

function NodeSetValue(value) {
  this.value = value;
  this.type = 'node-set';
}

NodeSetValue.prototype.stringValue = function() {
  if (this.value.length == 0) {
    return '';
  } else {
    return xmlValue(this.value[0]);
  }
}

NodeSetValue.prototype.booleanValue = function() {
  return this.value.length > 0;
}

NodeSetValue.prototype.numberValue = function() {
  return this.stringValue() - 0;
}

NodeSetValue.prototype.nodeSetValue = function() {
  return this.value;
};

// XPath expressions. They are used as nodes in the parse tree and
// possess an evaluate() method to compute an XPath value given an XPath
// context. Expressions are returned from the parser. Teh set of
// expression classes closely mirrors the set of non terminal symbols
// in the grammar. Every non trivial nonterminal symbol has a
// corresponding expression class.
//
// The common expression interface consists of the following methods:
//
// evaluate(context) -- evaluates the expression, returns a value.
//
// toString() -- returns the XPath text representation of the
// expression (defined in xsltdebug.js).
//
// parseTree(indent) -- returns a parse tree representation of the
// expression (defined in xsltdebug.js).

function TokenExpr(m) {
  this.value = m;
}

TokenExpr.prototype.evaluate = function() {
  return new StringValue(this.value);
};

function LocationExpr() {
  this.absolute = false;
  this.steps = [];
}

LocationExpr.prototype.appendStep = function(s) {
  this.steps.push(s);
}

LocationExpr.prototype.prependStep = function(s) {
  var steps0 = this.steps;
  this.steps = [ s ];
  for (var i = 0; i < steps0.length; ++i) {
    this.steps.push(steps0[i]);
  }
};

LocationExpr.prototype.evaluate = function(ctx) {
  var start;
  if (this.absolute) {
    start = ctx.root;

  } else {
    start = ctx.node;
  }

  var nodes = [];
  xPathStep(nodes, this.steps, 0, start, ctx);
  return new NodeSetValue(nodes);
};

function xPathStep(nodes, steps, step, input, ctx) {
  var s = steps[step];
  var ctx2 = ctx.clone(input);
  var nodelist = s.evaluate(ctx2).nodeSetValue();

  for (var i = 0; i < nodelist.length; ++i) {
    if (step == steps.length - 1) {
      nodes.push(nodelist[i]);
    } else {
      xPathStep(nodes, steps, step + 1, nodelist[i], ctx);
    }
  }
}

function StepExpr(axis, nodetest, opt_predicate) {
  this.axis = axis;
  this.nodetest = nodetest;
  this.predicate = opt_predicate || [];
}

StepExpr.prototype.appendPredicate = function(p) {
  this.predicate.push(p);
}

StepExpr.prototype.evaluate = function(ctx) {
  var input = ctx.node;
  var nodelist = [];

  // NOTE(mesch): When this was a switch() statement, it didn't work
  // in Safari/2.0. Not sure why though; it resulted in the JavaScript
  // console output "undefined" (without any line number or so).

  if (this.axis ==  xpathAxis.ANCESTOR_OR_SELF) {
    nodelist.push(input);
    for (var n = input.parentNode; n; n = n.parentNode) {
      nodelist.push(n);
    }

  } else if (this.axis == xpathAxis.ANCESTOR) {
    for (var n = input.parentNode; n; n = n.parentNode) {
      nodelist.push(n);
    }

  } else if (this.axis == xpathAxis.ATTRIBUTE) {
    copyArray(nodelist, input.attributes);

  } else if (this.axis == xpathAxis.CHILD) {
    copyArray(nodelist, input.childNodes);

  } else if (this.axis == xpathAxis.DESCENDANT_OR_SELF) {
    nodelist.push(input);
    xpathCollectDescendants(nodelist, input);

  } else if (this.axis == xpathAxis.DESCENDANT) {
    xpathCollectDescendants(nodelist, input);

  } else if (this.axis == xpathAxis.FOLLOWING) {
    for (var n = input; n; n = n.parentNode) {
      for (var nn = n.nextSibling; nn; nn = nn.nextSibling) {
        nodelist.push(nn);
        xpathCollectDescendants(nodelist, nn);
      }
    }

  } else if (this.axis == xpathAxis.FOLLOWING_SIBLING) {
    for (var n = input.nextSibling; n; n = n.nextSibling) {
      nodelist.push(n);
    }

  } else if (this.axis == xpathAxis.NAMESPACE) {
    alert('not implemented: axis namespace');

  } else if (this.axis == xpathAxis.PARENT) {
    if (input.parentNode) {
      nodelist.push(input.parentNode);
    }

  } else if (this.axis == xpathAxis.PRECEDING) {
    for (var n = input; n; n = n.parentNode) {
      for (var nn = n.previousSibling; nn; nn = nn.previousSibling) {
        nodelist.push(nn);
        xpathCollectDescendantsReverse(nodelist, nn);
      }
    }

  } else if (this.axis == xpathAxis.PRECEDING_SIBLING) {
    for (var n = input.previousSibling; n; n = n.previousSibling) {
      nodelist.push(n);
    }

  } else if (this.axis == xpathAxis.SELF) {
    nodelist.push(input);

  } else {
    throw 'ERROR -- NO SUCH AXIS: ' + this.axis;
  }

  // process node test
  var nodelist0 = nodelist;
  nodelist = [];
  for (var i = 0; i < nodelist0.length; ++i) {
    var n = nodelist0[i];
    if (this.nodetest.evaluate(ctx.clone(n, i, nodelist0)).booleanValue()) {
      nodelist.push(n);
    }
  }

  // process predicates
  for (var i = 0; i < this.predicate.length; ++i) {
    var nodelist0 = nodelist;
    nodelist = [];
    for (var ii = 0; ii < nodelist0.length; ++ii) {
      var n = nodelist0[ii];
      if (this.predicate[i].evaluate(ctx.clone(n, ii, nodelist0)).booleanValue()) {
        nodelist.push(n);
      }
    }
  }

  return new NodeSetValue(nodelist);
};

function NodeTestAny() {
  this.value = new BooleanValue(true);
}

NodeTestAny.prototype.evaluate = function(ctx) {
  return this.value;
};

function NodeTestElementOrAttribute() {}

NodeTestElementOrAttribute.prototype.evaluate = function(ctx) {
  return new BooleanValue(
      ctx.node.nodeType == DOM_ELEMENT_NODE ||
      ctx.node.nodeType == DOM_ATTRIBUTE_NODE);
}

function NodeTestText() {}

NodeTestText.prototype.evaluate = function(ctx) {
  return new BooleanValue(ctx.node.nodeType == DOM_TEXT_NODE);
}

function NodeTestComment() {}

NodeTestComment.prototype.evaluate = function(ctx) {
  return new BooleanValue(ctx.node.nodeType == DOM_COMMENT_NODE);
}

function NodeTestPI(target) {
  this.target = target;
}

NodeTestPI.prototype.evaluate = function(ctx) {
  return new
  BooleanValue(ctx.node.nodeType == DOM_PROCESSING_INSTRUCTION_NODE &&
               (!this.target || ctx.node.nodeName == this.target));
}

function NodeTestNC(nsprefix) {
  this.regex = new RegExp("^" + nsprefix + ":");
  this.nsprefix = nsprefix;
}

NodeTestNC.prototype.evaluate = function(ctx) {
  var n = ctx.node;
  return new BooleanValue(this.regex.match(n.nodeName));
}

function NodeTestName(name) {
  this.name = name;
}

NodeTestName.prototype.evaluate = function(ctx) {
  var n = ctx.node;
  return new BooleanValue(n.nodeName == this.name);
}

function PredicateExpr(expr) {
  this.expr = expr;
}

PredicateExpr.prototype.evaluate = function(ctx) {
  var v = this.expr.evaluate(ctx);
  if (v.type == 'number') {
    // NOTE(mesch): Internally, position is represented starting with
    // 0, however in XPath position starts with 1. See functions
    // position() and last().
    return new BooleanValue(ctx.position == v.numberValue() - 1);
  } else {
    return new BooleanValue(v.booleanValue());
  }
};

function FunctionCallExpr(name) {
  this.name = name;
  this.args = [];
}

FunctionCallExpr.prototype.appendArg = function(arg) {
  this.args.push(arg);
};

FunctionCallExpr.prototype.evaluate = function(ctx) {
  var fn = '' + this.name.value;
  var f = this.xpathfunctions[fn];
  if (f) {
    return f.call(this, ctx);
  } else {
    xpathLog('XPath NO SUCH FUNCTION ' + fn);
    return new BooleanValue(false);
  }
};

FunctionCallExpr.prototype.xpathfunctions = {
  'last': function(ctx) {
    assert(this.args.length == 0);
    // NOTE(mesch): XPath position starts at 1.
    return new NumberValue(ctx.contextSize());
  },

  'position': function(ctx) {
    assert(this.args.length == 0);
    // NOTE(mesch): XPath position starts at 1.
    return new NumberValue(ctx.position + 1);
  },

  'count': function(ctx) {
    assert(this.args.length == 1);
    var v = this.args[0].evaluate(ctx);
    return new NumberValue(v.nodeSetValue().length);
  },

  'id': function(ctx) {
    assert(this.args.length == 1);
    var e = this.args[0].evaluate(ctx);
    var ret = [];
    var ids;
    if (e.type == 'node-set') {
      ids = [];
      var en = e.nodeSetValue();
      for (var i = 0; i < en.length; ++i) {
        var v = xmlValue(en[i]).split(/\s+/);
        for (var ii = 0; ii < v.length; ++ii) {
          ids.push(v[ii]);
        }
      }
    } else {
      ids = e.stringValue().split(/\s+/);
    }
    var d = ctx.node.ownerDocument;
    for (var i = 0; i < ids.length; ++i) {
      var n = d.getElementById(ids[i]);
      if (n) {
        ret.push(n);
      }
    }
    return new NodeSetValue(ret);
  },

  'local-name': function(ctx) {
    alert('not implmented yet: XPath function local-name()');
  },

  'namespace-uri': function(ctx) {
    alert('not implmented yet: XPath function namespace-uri()');
  },

  'name': function(ctx) {
    assert(this.args.length == 1 || this.args.length == 0);
    var n;
    if (this.args.length == 0) {
      n = [ ctx.node ];
    } else {
      n = this.args[0].evaluate(ctx).nodeSetValue();
    }

    if (n.length == 0) {
      return new StringValue('');
    } else {
      return new StringValue(n[0].nodeName);
    }
  },

  'string':  function(ctx) {
    assert(this.args.length == 1 || this.args.length == 0);
    if (this.args.length == 0) {
      return new StringValue(new NodeSetValue([ ctx.node ]).stringValue());
    } else {
      return new StringValue(this.args[0].evaluate(ctx).stringValue());
    }
  },

  'concat': function(ctx) {
    var ret = '';
    for (var i = 0; i < this.args.length; ++i) {
      ret += this.args[i].evaluate(ctx).stringValue();
    }
    return new StringValue(ret);
  },

  'starts-with': function(ctx) {
    assert(this.args.length == 2);
    var s0 = this.args[0].evaluate(ctx).stringValue();
    var s1 = this.args[1].evaluate(ctx).stringValue();
    return new BooleanValue(s0.indexOf(s1) == 0);
  },

  'contains': function(ctx) {
    assert(this.args.length == 2);
    var s0 = this.args[0].evaluate(ctx).stringValue();
    var s1 = this.args[1].evaluate(ctx).stringValue();
    return new BooleanValue(s0.indexOf(s1) != -1);
  },

  'substring-before': function(ctx) {
    assert(this.args.length == 2);
    var s0 = this.args[0].evaluate(ctx).stringValue();
    var s1 = this.args[1].evaluate(ctx).stringValue();
    var i = s0.indexOf(s1);
    var ret;
    if (i == -1) {
      ret = '';
    } else {
      ret = s0.substr(0,i);
    }
    return new StringValue(ret);
  },

  'substring-after': function(ctx) {
    assert(this.args.length == 2);
    var s0 = this.args[0].evaluate(ctx).stringValue();
    var s1 = this.args[1].evaluate(ctx).stringValue();
    var i = s0.indexOf(s1);
    var ret;
    if (i == -1) {
      ret = '';
    } else {
      ret = s0.substr(i + s1.length);
    }
    return new StringValue(ret);
  },

  'substring': function(ctx) {
    // NOTE: XPath defines the position of the first character in a
    // string to be 1, in JavaScript this is 0 ([XPATH] Section 4.2).
    assert(this.args.length == 2 || this.args.length == 3);
    var s0 = this.args[0].evaluate(ctx).stringValue();
    var s1 = this.args[1].evaluate(ctx).numberValue();
    var ret;
    if (this.args.length == 2) {
      var i1 = Math.max(0, Math.round(s1) - 1);
      ret = s0.substr(i1);

    } else {
      var s2 = this.args[2].evaluate(ctx).numberValue();
      var i0 = Math.round(s1) - 1;
      var i1 = Math.max(0, i0);
      var i2 = Math.round(s2) - Math.max(0, -i0);
      ret = s0.substr(i1, i2);
    }
    return new StringValue(ret);
  },

  'string-length': function(ctx) {
    var s;
    if (this.args.length > 0) {
      s = this.args[0].evaluate(ctx).stringValue();
    } else {
      s = new NodeSetValue([ ctx.node ]).stringValue();
    }
    return new NumberValue(s.length);
  },

  'normalize-space': function(ctx) {
    var s;
    if (this.args.length > 0) {
      s = this.args[0].evaluate(ctx).stringValue();
    } else {
      s = new NodeSetValue([ ctx.node ]).stringValue();
    }
    s = s.replace(/^\s*/,'').replace(/\s*$/,'').replace(/\s+/g, ' ');
    return new StringValue(s);
  },

  'translate': function(ctx) {
    assert(this.args.length == 3);
    var s0 = this.args[0].evaluate(ctx).stringValue();
    var s1 = this.args[1].evaluate(ctx).stringValue();
    var s2 = this.args[2].evaluate(ctx).stringValue();

    for (var i = 0; i < s1.length; ++i) {
      s0 = s0.replace(new RegExp(s1.charAt(i), 'g'), s2.charAt(i));
    }
    return new StringValue(s0);
  },

  'boolean': function(ctx) {
    assert(this.args.length == 1);
    return new BooleanValue(this.args[0].evaluate(ctx).booleanValue());
  },

  'not': function(ctx) {
    assert(this.args.length == 1);
    var ret = !this.args[0].evaluate(ctx).booleanValue();
    return new BooleanValue(ret);
  },

  'true': function(ctx) {
    assert(this.args.length == 0);
    return new BooleanValue(true);
  },

  'false': function(ctx) {
    assert(this.args.length == 0);
    return new BooleanValue(false);
  },

  'lang': function(ctx) {
    assert(this.args.length == 1);
    var lang = this.args[0].evaluate(ctx).stringValue();
    var xmllang;
    var n = ctx.node;
    while (n && n != n.parentNode /* just in case ... */) {
      xmllang = n.getAttribute('xml:lang');
      if (xmllang) {
        break;
      }
      n = n.parentNode;
    }
    if (!xmllang) {
      return new BooleanValue(false);
    } else {
      var re = new RegExp('^' + lang + '$', 'i');
      return new BooleanValue(xmllang.match(re) ||
                              xmllang.replace(/_.*$/,'').match(re));
    }
  },

  'number': function(ctx) {
    assert(this.args.length == 1 || this.args.length == 0);

    if (this.args.length == 1) {
      return new NumberValue(this.args[0].evaluate(ctx).numberValue());
    } else {
      return new NumberValue(new NodeSetValue([ ctx.node ]).numberValue());
    }
  },

  'sum': function(ctx) {
    assert(this.args.length == 1);
    var n = this.args[0].evaluate(ctx).nodeSetValue();
    var sum = 0;
    for (var i = 0; i < n.length; ++i) {
      sum += xmlValue(n[i]) - 0;
    }
    return new NumberValue(sum);
  },

  'floor': function(ctx) {
    assert(this.args.length == 1);
    var num = this.args[0].evaluate(ctx).numberValue();
    return new NumberValue(Math.floor(num));
  },

  'ceiling': function(ctx) {
    assert(this.args.length == 1);
    var num = this.args[0].evaluate(ctx).numberValue();
    return new NumberValue(Math.ceil(num));
  },

  'round': function(ctx) {
    assert(this.args.length == 1);
    var num = this.args[0].evaluate(ctx).numberValue();
    return new NumberValue(Math.round(num));
  },

  // TODO(mesch): The following functions are custom. There is a
  // standard that defines how to add functions, which should be
  // applied here.

  'ext-join': function(ctx) {
    assert(this.args.length == 2);
    var nodes = this.args[0].evaluate(ctx).nodeSetValue();
    var delim = this.args[1].evaluate(ctx).stringValue();
    var ret = '';
    for (var i = 0; i < nodes.length; ++i) {
      if (ret) {
        ret += delim;
      }
      ret += xmlValue(nodes[i]);
    }
    return new StringValue(ret);
  },

  // ext-if() evaluates and returns its second argument, if the
  // boolean value of its first argument is true, otherwise it
  // evaluates and returns its third argument.

  'ext-if': function(ctx) {
    assert(this.args.length == 3);
    if (this.args[0].evaluate(ctx).booleanValue()) {
      return this.args[1].evaluate(ctx);
    } else {
      return this.args[2].evaluate(ctx);
    }
  },

  // ext-cardinal() evaluates its single argument as a number, and
  // returns the current node that many times. It can be used in the
  // select attribute to iterate over an integer range.

  'ext-cardinal': function(ctx) {
    assert(this.args.length >= 1);
    var c = this.args[0].evaluate(ctx).numberValue();
    var ret = [];
    for (var i = 0; i < c; ++i) {
      ret.push(ctx.node);
    }
    return new NodeSetValue(ret);
  }
};

function UnionExpr(expr1, expr2) {
  this.expr1 = expr1;
  this.expr2 = expr2;
}

UnionExpr.prototype.evaluate = function(ctx) {
  var nodes1 = this.expr1.evaluate(ctx).nodeSetValue();
  var nodes2 = this.expr2.evaluate(ctx).nodeSetValue();
  var I1 = nodes1.length;
  for (var i2 = 0; i2 < nodes2.length; ++i2) {
    var n = nodes2[i2];
    var inBoth = false;
    for (var i1 = 0; i1 < I1; ++i1) {
      if (nodes1[i1] == n) {
        inBoth = true;
        i1 = I1; // break inner loop
      }
    }
    if (!inBoth) {
      nodes1.push(n);
    }
  }
  return new NodeSetValue(nodes1);
};

function PathExpr(filter, rel) {
  this.filter = filter;
  this.rel = rel;
}

PathExpr.prototype.evaluate = function(ctx) {
  var nodes = this.filter.evaluate(ctx).nodeSetValue();
  var nodes1 = [];
  for (var i = 0; i < nodes.length; ++i) {
    var nodes0 = this.rel.evaluate(ctx.clone(nodes[i], i, nodes)).nodeSetValue();
    for (var ii = 0; ii < nodes0.length; ++ii) {
      nodes1.push(nodes0[ii]);
    }
  }
  return new NodeSetValue(nodes1);
};

function FilterExpr(expr, predicate) {
  this.expr = expr;
  this.predicate = predicate;
}

FilterExpr.prototype.evaluate = function(ctx) {
  var nodes = this.expr.evaluate(ctx).nodeSetValue();
  for (var i = 0; i < this.predicate.length; ++i) {
    var nodes0 = nodes;
    nodes = [];
    for (var j = 0; j < nodes0.length; ++j) {
      var n = nodes0[j];
      if (this.predicate[i].evaluate(ctx.clone(n, j, nodes0)).booleanValue()) {
        nodes.push(n);
      }
    }
  }

  return new NodeSetValue(nodes);
}

function UnaryMinusExpr(expr) {
  this.expr = expr;
}

UnaryMinusExpr.prototype.evaluate = function(ctx) {
  return new NumberValue(-this.expr.evaluate(ctx).numberValue());
};

function BinaryExpr(expr1, op, expr2) {
  this.expr1 = expr1;
  this.expr2 = expr2;
  this.op = op;
}

BinaryExpr.prototype.evaluate = function(ctx) {
  var ret;
  switch (this.op.value) {
    case 'or':
      ret = new BooleanValue(this.expr1.evaluate(ctx).booleanValue() ||
                             this.expr2.evaluate(ctx).booleanValue());
      break;

    case 'and':
      ret = new BooleanValue(this.expr1.evaluate(ctx).booleanValue() &&
                             this.expr2.evaluate(ctx).booleanValue());
      break;

    case '+':
      ret = new NumberValue(this.expr1.evaluate(ctx).numberValue() +
                            this.expr2.evaluate(ctx).numberValue());
      break;

    case '-':
      ret = new NumberValue(this.expr1.evaluate(ctx).numberValue() -
                            this.expr2.evaluate(ctx).numberValue());
      break;

    case '*':
      ret = new NumberValue(this.expr1.evaluate(ctx).numberValue() *
                            this.expr2.evaluate(ctx).numberValue());
      break;

    case 'mod':
      ret = new NumberValue(this.expr1.evaluate(ctx).numberValue() %
                            this.expr2.evaluate(ctx).numberValue());
      break;

    case 'div':
      ret = new NumberValue(this.expr1.evaluate(ctx).numberValue() /
                            this.expr2.evaluate(ctx).numberValue());
      break;

    case '=':
      ret = this.compare(ctx, function(x1, x2) { return x1 == x2; });
      break;

    case '!=':
      ret = this.compare(ctx, function(x1, x2) { return x1 != x2; });
      break;

    case '<':
      ret = this.compare(ctx, function(x1, x2) { return x1 < x2; });
      break;

    case '<=':
      ret = this.compare(ctx, function(x1, x2) { return x1 <= x2; });
      break;

    case '>':
      ret = this.compare(ctx, function(x1, x2) { return x1 > x2; });
      break;

    case '>=':
      ret = this.compare(ctx, function(x1, x2) { return x1 >= x2; });
      break;

    default:
      alert('BinaryExpr.evaluate: ' + this.op.value);
  }
  return ret;
};

BinaryExpr.prototype.compare = function(ctx, cmp) {
  var v1 = this.expr1.evaluate(ctx);
  var v2 = this.expr2.evaluate(ctx);

  var ret;
  if (v1.type == 'node-set' && v2.type == 'node-set') {
    var n1 = v1.nodeSetValue();
    var n2 = v2.nodeSetValue();
    ret = false;
    for (var i1 = 0; i1 < n1.length; ++i1) {
      for (var i2 = 0; i2 < n2.length; ++i2) {
        if (cmp(xmlValue(n1[i1]), xmlValue(n2[i2]))) {
          ret = true;
          // Break outer loop. Labels confuse the jscompiler and we
          // don't use them.
          i2 = n2.length;
          i1 = n1.length;
        }
      }
    }

  } else if (v1.type == 'node-set' || v2.type == 'node-set') {

    if (v1.type == 'number') {
      var s = v1.numberValue();
      var n = v2.nodeSetValue();

      ret = false;
      for (var i = 0;  i < n.length; ++i) {
        var nn = xmlValue(n[i]) - 0;
        if (cmp(s, nn)) {
          ret = true;
          break;
        }
      }

    } else if (v2.type == 'number') {
      var n = v1.nodeSetValue();
      var s = v2.numberValue();

      ret = false;
      for (var i = 0;  i < n.length; ++i) {
        var nn = xmlValue(n[i]) - 0;
        if (cmp(nn, s)) {
          ret = true;
          break;
        }
      }

    } else if (v1.type == 'string') {
      var s = v1.stringValue();
      var n = v2.nodeSetValue();

      ret = false;
      for (var i = 0;  i < n.length; ++i) {
        var nn = xmlValue(n[i]);
        if (cmp(s, nn)) {
          ret = true;
          break;
        }
      }

    } else if (v2.type == 'string') {
      var n = v1.nodeSetValue();
      var s = v2.stringValue();

      ret = false;
      for (var i = 0;  i < n.length; ++i) {
        var nn = xmlValue(n[i]);
        if (cmp(nn, s)) {
          ret = true;
          break;
        }
      }

    } else {
      ret = cmp(v1.booleanValue(), v2.booleanValue());
    }

  } else if (v1.type == 'boolean' || v2.type == 'boolean') {
    ret = cmp(v1.booleanValue(), v2.booleanValue());

  } else if (v1.type == 'number' || v2.type == 'number') {
    ret = cmp(v1.numberValue(), v2.numberValue());

  } else {
    ret = cmp(v1.stringValue(), v2.stringValue());
  }

  return new BooleanValue(ret);
}

function LiteralExpr(value) {
  this.value = value;
}

LiteralExpr.prototype.evaluate = function(ctx) {
  return new StringValue(this.value);
};

function NumberExpr(value) {
  this.value = value;
}

NumberExpr.prototype.evaluate = function(ctx) {
  return new NumberValue(this.value);
};

function VariableExpr(name) {
  this.name = name;
}

VariableExpr.prototype.evaluate = function(ctx) {
  return ctx.getVariable(this.name);
}

// Factory functions for semantic values (i.e. Expressions) of the
// productions in the grammar. When a production is matched to reduce
// the current parse state stack, the function is called with the
// semantic values of the matched elements as arguments, and returns
// another semantic value. The semantic value is a node of the parse
// tree, an expression object with an evaluate() method that evaluates the
// expression in an actual context. These factory functions are used
// in the specification of the grammar rules, below.

function makeTokenExpr(m) {
  return new TokenExpr(m);
}

function passExpr(e) {
  return e;
}

function makeLocationExpr1(slash, rel) {
  rel.absolute = true;
  return rel;
}

function makeLocationExpr2(dslash, rel) {
  rel.absolute = true;
  rel.prependStep(makeAbbrevStep(dslash.value));
  return rel;
}

function makeLocationExpr3(slash) {
  var ret = new LocationExpr();
  ret.appendStep(makeAbbrevStep('.'));
  ret.absolute = true;
  return ret;
}

function makeLocationExpr4(dslash) {
  var ret = new LocationExpr();
  ret.absolute = true;
  ret.appendStep(makeAbbrevStep(dslash.value));
  return ret;
}

function makeLocationExpr5(step) {
  var ret = new LocationExpr();
  ret.appendStep(step);
  return ret;
}

function makeLocationExpr6(rel, slash, step) {
  rel.appendStep(step);
  return rel;
}

function makeLocationExpr7(rel, dslash, step) {
  rel.appendStep(makeAbbrevStep(dslash.value));
  return rel;
}

function makeStepExpr1(dot) {
  return makeAbbrevStep(dot.value);
}

function makeStepExpr2(ddot) {
  return makeAbbrevStep(ddot.value);
}

function makeStepExpr3(axisname, axis, nodetest) {
  return new StepExpr(axisname.value, nodetest);
}

function makeStepExpr4(at, nodetest) {
  return new StepExpr('attribute', nodetest);
}

function makeStepExpr5(nodetest) {
  return new StepExpr('child', nodetest);
}

function makeStepExpr6(step, predicate) {
  step.appendPredicate(predicate);
  return step;
}

function makeAbbrevStep(abbrev) {
  switch (abbrev) {
  case '//':
    return new StepExpr('descendant-or-self', new NodeTestAny);

  case '.':
    return new StepExpr('self', new NodeTestAny);

  case '..':
    return new StepExpr('parent', new NodeTestAny);
  }
}

function makeNodeTestExpr1(asterisk) {
  return new NodeTestElementOrAttribute;
}

function makeNodeTestExpr2(ncname, colon, asterisk) {
  return new NodeTestNC(ncname.value);
}

function makeNodeTestExpr3(qname) {
  return new NodeTestName(qname.value);
}

function makeNodeTestExpr4(typeo, parenc) {
  var type = typeo.value.replace(/\s*\($/, '');
  switch(type) {
  case 'node':
    return new NodeTestAny;

  case 'text':
    return new NodeTestText;

  case 'comment':
    return new NodeTestComment;

  case 'processing-instruction':
    return new NodeTestPI('');
  }
}

function makeNodeTestExpr5(typeo, target, parenc) {
  var type = typeo.replace(/\s*\($/, '');
  if (type != 'processing-instruction') {
    throw type;
  }
  return new NodeTestPI(target.value);
}

function makePredicateExpr(pareno, expr, parenc) {
  return new PredicateExpr(expr);
}

function makePrimaryExpr(pareno, expr, parenc) {
  return expr;
}

function makeFunctionCallExpr1(name, pareno, parenc) {
  return new FunctionCallExpr(name);
}

function makeFunctionCallExpr2(name, pareno, arg1, args, parenc) {
  var ret = new FunctionCallExpr(name);
  ret.appendArg(arg1);
  for (var i = 0; i < args.length; ++i) {
    ret.appendArg(args[i]);
  }
  return ret;
}

function makeArgumentExpr(comma, expr) {
  return expr;
}

function makeUnionExpr(expr1, pipe, expr2) {
  return new UnionExpr(expr1, expr2);
}

function makePathExpr1(filter, slash, rel) {
  return new PathExpr(filter, rel);
}

function makePathExpr2(filter, dslash, rel) {
  rel.prependStep(makeAbbrevStep(dslash.value));
  return new PathExpr(filter, rel);
}

function makeFilterExpr(expr, predicates) {
  if (predicates.length > 0) {
    return new FilterExpr(expr, predicates);
  } else {
    return expr;
  }
}

function makeUnaryMinusExpr(minus, expr) {
  return new UnaryMinusExpr(expr);
}

function makeBinaryExpr(expr1, op, expr2) {
  return new BinaryExpr(expr1, op, expr2);
}

function makeLiteralExpr(token) {
  // remove quotes from the parsed value:
  var value = token.value.substring(1, token.value.length - 1);
  return new LiteralExpr(value);
}

function makeNumberExpr(token) {
  return new NumberExpr(token.value);
}

function makeVariableReference(dollar, name) {
  return new VariableExpr(name.value);
}

// Used before parsing for optimization of common simple cases. See
// the begin of xpathParse() for which they are.
function makeSimpleExpr(expr) {
  if (expr.charAt(0) == '$') {
    return new VariableExpr(expr.substr(1));
  } else if (expr.charAt(0) == '@') {
    var a = new NodeTestName(expr.substr(1));
    var b = new StepExpr('attribute', a);
    var c = new LocationExpr();
    c.appendStep(b);
    return c;
  } else if (expr.match(/^[0-9]+$/)) {
    return new NumberExpr(expr);
  } else {
    var a = new NodeTestName(expr);
    var b = new StepExpr('child', a);
    var c = new LocationExpr();
    c.appendStep(b);
    return c;
  }
}

function makeSimpleExpr2(expr) {
  var steps = stringSplit(expr, '/');
  var c = new LocationExpr();
  for (var i = 0; i < steps.length; ++i) {
    var a = new NodeTestName(steps[i]);
    var b = new StepExpr('child', a);
    c.appendStep(b);
  }
  return c;
}

// The axes of XPath expressions.

var xpathAxis = {
  ANCESTOR_OR_SELF: 'ancestor-or-self',
  ANCESTOR: 'ancestor',
  ATTRIBUTE: 'attribute',
  CHILD: 'child',
  DESCENDANT_OR_SELF: 'descendant-or-self',
  DESCENDANT: 'descendant',
  FOLLOWING_SIBLING: 'following-sibling',
  FOLLOWING: 'following',
  NAMESPACE: 'namespace',
  PARENT: 'parent',
  PRECEDING_SIBLING: 'preceding-sibling',
  PRECEDING: 'preceding',
  SELF: 'self'
};

var xpathAxesRe = [
    xpathAxis.ANCESTOR_OR_SELF,
    xpathAxis.ANCESTOR,
    xpathAxis.ATTRIBUTE,
    xpathAxis.CHILD,
    xpathAxis.DESCENDANT_OR_SELF,
    xpathAxis.DESCENDANT,
    xpathAxis.FOLLOWING_SIBLING,
    xpathAxis.FOLLOWING,
    xpathAxis.NAMESPACE,
    xpathAxis.PARENT,
    xpathAxis.PRECEDING_SIBLING,
    xpathAxis.PRECEDING,
    xpathAxis.SELF
].join('|');


// The tokens of the language. The label property is just used for
// generating debug output. The prec property is the precedence used
// for shift/reduce resolution. Default precedence is 0 as a lookahead
// token and 2 on the stack. TODO(mesch): this is certainly not
// necessary and too complicated. Simplify this!

// NOTE: tabular formatting is the big exception, but here it should
// be OK.

var TOK_PIPE =   { label: "|",   prec:   17, re: new RegExp("^\\|") };
var TOK_DSLASH = { label: "//",  prec:   19, re: new RegExp("^//")  };
var TOK_SLASH =  { label: "/",   prec:   30, re: new RegExp("^/")   };
var TOK_AXIS =   { label: "::",  prec:   20, re: new RegExp("^::")  };
var TOK_COLON =  { label: ":",   prec: 1000, re: new RegExp("^:")  };
var TOK_AXISNAME = { label: "[axis]", re: new RegExp('^(' + xpathAxesRe + ')') };
var TOK_PARENO = { label: "(",   prec:   34, re: new RegExp("^\\(") };
var TOK_PARENC = { label: ")",               re: new RegExp("^\\)") };
var TOK_DDOT =   { label: "..",  prec:   34, re: new RegExp("^\\.\\.") };
var TOK_DOT =    { label: ".",   prec:   34, re: new RegExp("^\\.") };
var TOK_AT =     { label: "@",   prec:   34, re: new RegExp("^@")   };

var TOK_COMMA =  { label: ",",               re: new RegExp("^,") };

var TOK_OR =     { label: "or",  prec:   10, re: new RegExp("^or\\b") };
var TOK_AND =    { label: "and", prec:   11, re: new RegExp("^and\\b") };
var TOK_EQ =     { label: "=",   prec:   12, re: new RegExp("^=")   };
var TOK_NEQ =    { label: "!=",  prec:   12, re: new RegExp("^!=")  };
var TOK_GE =     { label: ">=",  prec:   13, re: new RegExp("^>=")  };
var TOK_GT =     { label: ">",   prec:   13, re: new RegExp("^>")   };
var TOK_LE =     { label: "<=",  prec:   13, re: new RegExp("^<=")  };
var TOK_LT =     { label: "<",   prec:   13, re: new RegExp("^<")   };
var TOK_PLUS =   { label: "+",   prec:   14, re: new RegExp("^\\+"), left: true };
var TOK_MINUS =  { label: "-",   prec:   14, re: new RegExp("^\\-"), left: true };
var TOK_DIV =    { label: "div", prec:   15, re: new RegExp("^div\\b"), left: true };
var TOK_MOD =    { label: "mod", prec:   15, re: new RegExp("^mod\\b"), left: true };

var TOK_BRACKO = { label: "[",   prec:   32, re: new RegExp("^\\[") };
var TOK_BRACKC = { label: "]",               re: new RegExp("^\\]") };
var TOK_DOLLAR = { label: "$",               re: new RegExp("^\\$") };

var TOK_NCNAME = { label: "[ncname]", re: new RegExp('^' + XML_NC_NAME) };

var TOK_ASTERISK = { label: "*", prec: 15, re: new RegExp("^\\*"), left: true };
var TOK_LITERALQ = { label: "[litq]", prec: 20, re: new RegExp("^'[^\\']*'") };
var TOK_LITERALQQ = {
  label: "[litqq]",
  prec: 20,
  re: new RegExp('^"[^\\"]*"')
};

var TOK_NUMBER  = {
  label: "[number]",
  prec: 35,
  re: new RegExp('^\\d+(\\.\\d*)?') };

var TOK_QNAME = {
  label: "[qname]",
  re: new RegExp('^(' + XML_NC_NAME + ':)?' + XML_NC_NAME)
};

var TOK_NODEO = {
  label: "[nodetest-start]",
  re: new RegExp('^(processing-instruction|comment|text|node)\\(')
};

// The table of the tokens of our grammar, used by the lexer: first
// column the tag, second column a regexp to recognize it in the
// input, third column the precedence of the token, fourth column a
// factory function for the semantic value of the token.
//
// NOTE: order of this list is important, because the first match
// counts. Cf. DDOT and DOT, and AXIS and COLON.

var xpathTokenRules = [
    TOK_DSLASH,
    TOK_SLASH,
    TOK_DDOT,
    TOK_DOT,
    TOK_AXIS,
    TOK_COLON,
    TOK_AXISNAME,
    TOK_NODEO,
    TOK_PARENO,
    TOK_PARENC,
    TOK_BRACKO,
    TOK_BRACKC,
    TOK_AT,
    TOK_COMMA,
    TOK_OR,
    TOK_AND,
    TOK_NEQ,
    TOK_EQ,
    TOK_GE,
    TOK_GT,
    TOK_LE,
    TOK_LT,
    TOK_PLUS,
    TOK_MINUS,
    TOK_ASTERISK,
    TOK_PIPE,
    TOK_MOD,
    TOK_DIV,
    TOK_LITERALQ,
    TOK_LITERALQQ,
    TOK_NUMBER,
    TOK_QNAME,
    TOK_NCNAME,
    TOK_DOLLAR
];

// All the nonterminals of the grammar. The nonterminal objects are
// identified by object identity; the labels are used in the debug
// output only.
var XPathLocationPath = { label: "LocationPath" };
var XPathRelativeLocationPath = { label: "RelativeLocationPath" };
var XPathAbsoluteLocationPath = { label: "AbsoluteLocationPath" };
var XPathStep = { label: "Step" };
var XPathNodeTest = { label: "NodeTest" };
var XPathPredicate = { label: "Predicate" };
var XPathLiteral = { label: "Literal" };
var XPathExpr = { label: "Expr" };
var XPathPrimaryExpr = { label: "PrimaryExpr" };
var XPathVariableReference = { label: "Variablereference" };
var XPathNumber = { label: "Number" };
var XPathFunctionCall = { label: "FunctionCall" };
var XPathArgumentRemainder = { label: "ArgumentRemainder" };
var XPathPathExpr = { label: "PathExpr" };
var XPathUnionExpr = { label: "UnionExpr" };
var XPathFilterExpr = { label: "FilterExpr" };
var XPathDigits = { label: "Digits" };

var xpathNonTerminals = [
    XPathLocationPath,
    XPathRelativeLocationPath,
    XPathAbsoluteLocationPath,
    XPathStep,
    XPathNodeTest,
    XPathPredicate,
    XPathLiteral,
    XPathExpr,
    XPathPrimaryExpr,
    XPathVariableReference,
    XPathNumber,
    XPathFunctionCall,
    XPathArgumentRemainder,
    XPathPathExpr,
    XPathUnionExpr,
    XPathFilterExpr,
    XPathDigits
];

// Quantifiers that are used in the productions of the grammar.
var Q_01 = { label: "?" };
var Q_MM = { label: "*" };
var Q_1M = { label: "+" };

// Tag for left associativity (right assoc is implied by undefined).
var ASSOC_LEFT = true;

// The productions of the grammar. Columns of the table:
//
// - target nonterminal,
// - pattern,
// - precedence,
// - semantic value factory
//
// The semantic value factory is a function that receives parse tree
// nodes from the stack frames of the matched symbols as arguments and
// returns an a node of the parse tree. The node is stored in the top
// stack frame along with the target object of the rule. The node in
// the parse tree is an expression object that has an evaluate() method
// and thus evaluates XPath expressions.
//
// The precedence is used to decide between reducing and shifting by
// comparing the precendence of the rule that is candidate for
// reducing with the precedence of the look ahead token. Precedence of
// -1 means that the precedence of the tokens in the pattern is used
// instead. TODO: It shouldn't be necessary to explicitly assign
// precedences to rules.

var xpathGrammarRules =
  [
   [ XPathLocationPath, [ XPathRelativeLocationPath ], 18,
     passExpr ],
   [ XPathLocationPath, [ XPathAbsoluteLocationPath ], 18,
     passExpr ],

   [ XPathAbsoluteLocationPath, [ TOK_SLASH, XPathRelativeLocationPath ], 18,
     makeLocationExpr1 ],
   [ XPathAbsoluteLocationPath, [ TOK_DSLASH, XPathRelativeLocationPath ], 18,
     makeLocationExpr2 ],

   [ XPathAbsoluteLocationPath, [ TOK_SLASH ], 0,
     makeLocationExpr3 ],
   [ XPathAbsoluteLocationPath, [ TOK_DSLASH ], 0,
     makeLocationExpr4 ],

   [ XPathRelativeLocationPath, [ XPathStep ], 31,
     makeLocationExpr5 ],
   [ XPathRelativeLocationPath,
     [ XPathRelativeLocationPath, TOK_SLASH, XPathStep ], 31,
     makeLocationExpr6 ],
   [ XPathRelativeLocationPath,
     [ XPathRelativeLocationPath, TOK_DSLASH, XPathStep ], 31,
     makeLocationExpr7 ],

   [ XPathStep, [ TOK_DOT ], 33,
     makeStepExpr1 ],
   [ XPathStep, [ TOK_DDOT ], 33,
     makeStepExpr2 ],
   [ XPathStep,
     [ TOK_AXISNAME, TOK_AXIS, XPathNodeTest ], 33,
     makeStepExpr3 ],
   [ XPathStep, [ TOK_AT, XPathNodeTest ], 33,
     makeStepExpr4 ],
   [ XPathStep, [ XPathNodeTest ], 33,
     makeStepExpr5 ],
   [ XPathStep, [ XPathStep, XPathPredicate ], 33,
     makeStepExpr6 ],

   [ XPathNodeTest, [ TOK_ASTERISK ], 33,
     makeNodeTestExpr1 ],
   [ XPathNodeTest, [ TOK_NCNAME, TOK_COLON, TOK_ASTERISK ], 33,
     makeNodeTestExpr2 ],
   [ XPathNodeTest, [ TOK_QNAME ], 33,
     makeNodeTestExpr3 ],
   [ XPathNodeTest, [ TOK_NODEO, TOK_PARENC ], 33,
     makeNodeTestExpr4 ],
   [ XPathNodeTest, [ TOK_NODEO, XPathLiteral, TOK_PARENC ], 33,
     makeNodeTestExpr5 ],

   [ XPathPredicate, [ TOK_BRACKO, XPathExpr, TOK_BRACKC ], 33,
     makePredicateExpr ],

   [ XPathPrimaryExpr, [ XPathVariableReference ], 33,
     passExpr ],
   [ XPathPrimaryExpr, [ TOK_PARENO, XPathExpr, TOK_PARENC ], 33,
     makePrimaryExpr ],
   [ XPathPrimaryExpr, [ XPathLiteral ], 30,
     passExpr ],
   [ XPathPrimaryExpr, [ XPathNumber ], 30,
     passExpr ],
   [ XPathPrimaryExpr, [ XPathFunctionCall ], 30,
     passExpr ],

   [ XPathFunctionCall, [ TOK_QNAME, TOK_PARENO, TOK_PARENC ], -1,
     makeFunctionCallExpr1 ],
   [ XPathFunctionCall,
     [ TOK_QNAME, TOK_PARENO, XPathExpr, XPathArgumentRemainder, Q_MM,
       TOK_PARENC ], -1,
     makeFunctionCallExpr2 ],
   [ XPathArgumentRemainder, [ TOK_COMMA, XPathExpr ], -1,
     makeArgumentExpr ],

   [ XPathUnionExpr, [ XPathPathExpr ], 20,
     passExpr ],
   [ XPathUnionExpr, [ XPathUnionExpr, TOK_PIPE, XPathPathExpr ], 20,
     makeUnionExpr ],

   [ XPathPathExpr, [ XPathLocationPath ], 20,
     passExpr ],
   [ XPathPathExpr, [ XPathFilterExpr ], 19,
     passExpr ],
   [ XPathPathExpr,
     [ XPathFilterExpr, TOK_SLASH, XPathRelativeLocationPath ], 20,
     makePathExpr1 ],
   [ XPathPathExpr,
     [ XPathFilterExpr, TOK_DSLASH, XPathRelativeLocationPath ], 20,
     makePathExpr2 ],

   [ XPathFilterExpr, [ XPathPrimaryExpr, XPathPredicate, Q_MM ], 20,
     makeFilterExpr ],

   [ XPathExpr, [ XPathPrimaryExpr ], 16,
     passExpr ],
   [ XPathExpr, [ XPathUnionExpr ], 16,
     passExpr ],

   [ XPathExpr, [ TOK_MINUS, XPathExpr ], -1,
     makeUnaryMinusExpr ],

   [ XPathExpr, [ XPathExpr, TOK_OR, XPathExpr ], -1,
     makeBinaryExpr ],
   [ XPathExpr, [ XPathExpr, TOK_AND, XPathExpr ], -1,
     makeBinaryExpr ],

   [ XPathExpr, [ XPathExpr, TOK_EQ, XPathExpr ], -1,
     makeBinaryExpr ],
   [ XPathExpr, [ XPathExpr, TOK_NEQ, XPathExpr ], -1,
     makeBinaryExpr ],

   [ XPathExpr, [ XPathExpr, TOK_LT, XPathExpr ], -1,
     makeBinaryExpr ],
   [ XPathExpr, [ XPathExpr, TOK_LE, XPathExpr ], -1,
     makeBinaryExpr ],
   [ XPathExpr, [ XPathExpr, TOK_GT, XPathExpr ], -1,
     makeBinaryExpr ],
   [ XPathExpr, [ XPathExpr, TOK_GE, XPathExpr ], -1,
     makeBinaryExpr ],

   [ XPathExpr, [ XPathExpr, TOK_PLUS, XPathExpr ], -1,
     makeBinaryExpr, ASSOC_LEFT ],
   [ XPathExpr, [ XPathExpr, TOK_MINUS, XPathExpr ], -1,
     makeBinaryExpr, ASSOC_LEFT ],

   [ XPathExpr, [ XPathExpr, TOK_ASTERISK, XPathExpr ], -1,
     makeBinaryExpr, ASSOC_LEFT ],
   [ XPathExpr, [ XPathExpr, TOK_DIV, XPathExpr ], -1,
     makeBinaryExpr, ASSOC_LEFT ],
   [ XPathExpr, [ XPathExpr, TOK_MOD, XPathExpr ], -1,
     makeBinaryExpr, ASSOC_LEFT ],

   [ XPathLiteral, [ TOK_LITERALQ ], -1,
     makeLiteralExpr ],
   [ XPathLiteral, [ TOK_LITERALQQ ], -1,
     makeLiteralExpr ],

   [ XPathNumber, [ TOK_NUMBER ], -1,
     makeNumberExpr ],

   [ XPathVariableReference, [ TOK_DOLLAR, TOK_QNAME ], 200,
     makeVariableReference ]
   ];

// That function computes some optimizations of the above data
// structures and will be called right here. It merely takes the
// counter variables out of the global scope.

var xpathRules = [];

function xpathParseInit() {
  if (xpathRules.length) {
    return;
  }

  // Some simple optimizations for the xpath expression parser: sort
  // grammar rules descending by length, so that the longest match is
  // first found.

  xpathGrammarRules.sort(function(a,b) {
    var la = a[1].length;
    var lb = b[1].length;
    if (la < lb) {
      return 1;
    } else if (la > lb) {
      return -1;
    } else {
      return 0;
    }
  });

  var k = 1;
  for (var i = 0; i < xpathNonTerminals.length; ++i) {
    xpathNonTerminals[i].key = k++;
  }

  for (i = 0; i < xpathTokenRules.length; ++i) {
    xpathTokenRules[i].key = k++;
  }

  xpathLog('XPath parse INIT: ' + k + ' rules');

  // Another slight optimization: sort the rules into bins according
  // to the last element (observing quantifiers), so we can restrict
  // the match against the stack to the subest of rules that match the
  // top of the stack.
  //
  // TODO(mesch): What we actually want is to compute states as in
  // bison, so that we don't have to do any explicit and iterated
  // match against the stack.

  function push_(array, position, element) {
    if (!array[position]) {
      array[position] = [];
    }
    array[position].push(element);
  }

  for (i = 0; i < xpathGrammarRules.length; ++i) {
    var rule = xpathGrammarRules[i];
    var pattern = rule[1];

    for (var j = pattern.length - 1; j >= 0; --j) {
      if (pattern[j] == Q_1M) {
        push_(xpathRules, pattern[j-1].key, rule);
        break;

      } else if (pattern[j] == Q_MM || pattern[j] == Q_01) {
        push_(xpathRules, pattern[j-1].key, rule);
        --j;

      } else {
        push_(xpathRules, pattern[j].key, rule);
        break;
      }
    }
  }

  xpathLog('XPath parse INIT: ' + xpathRules.length + ' rule bins');

  var sum = 0;
  mapExec(xpathRules, function(i) {
    if (i) {
      sum += i.length;
    }
  });

  xpathLog('XPath parse INIT: ' + (sum / xpathRules.length) +
           ' average bin size');
}

// Local utility functions that are used by the lexer or parser.

function xpathCollectDescendants(nodelist, node) {
  for (var n = node.firstChild; n; n = n.nextSibling) {
    nodelist.push(n);
    arguments.callee(nodelist, n);
  }
}

function xpathCollectDescendantsReverse(nodelist, node) {
  for (var n = node.lastChild; n; n = n.previousSibling) {
    nodelist.push(n);
    arguments.callee(nodelist, n);
  }
}


// The entry point for the library: match an expression against a DOM
// node. Returns an XPath value.
function xpathDomEval(expr, node) {
  var expr1 = xpathParse(expr);
  var ret = expr1.evaluate(new ExprContext(node));
  return ret;
}

// Utility function to sort a list of nodes. Used by xsltSort() and
// nxslSelect().
function xpathSort(input, sort) {
  if (sort.length == 0) {
    return;
  }

  var sortlist = [];

  for (var i = 0; i < input.contextSize(); ++i) {
    var node = input.nodelist[i];
    var sortitem = { node: node, key: [] };
    var context = input.clone(node, 0, [ node ]);

    for (var j = 0; j < sort.length; ++j) {
      var s = sort[j];
      var value = s.expr.evaluate(context);

      var evalue;
      if (s.type == 'text') {
        evalue = value.stringValue();
      } else if (s.type == 'number') {
        evalue = value.numberValue();
      }
      sortitem.key.push({ value: evalue, order: s.order });
    }

    // Make the sort stable by adding a lowest priority sort by
    // id. This is very convenient and furthermore required by the
    // spec ([XSLT] - Section 10 Sorting).
    sortitem.key.push({ value: i, order: 'ascending' });

    sortlist.push(sortitem);
  }

  sortlist.sort(xpathSortByKey);

  var nodes = [];
  for (var i = 0; i < sortlist.length; ++i) {
    nodes.push(sortlist[i].node);
  }
  input.nodelist = nodes;
  input.setNode(0);
}


// Sorts by all order criteria defined. According to the JavaScript
// spec ([ECMA] Section 11.8.5), the compare operators compare strings
// as strings and numbers as numbers.
//
// NOTE: In browsers which do not follow the spec, this breaks only in
// the case that numbers should be sorted as strings, which is very
// uncommon.
function xpathSortByKey(v1, v2) {
  // NOTE: Sort key vectors of different length never occur in
  // xsltSort.

  for (var i = 0; i < v1.key.length; ++i) {
    var o = v1.key[i].order == 'descending' ? -1 : 1;
    if (v1.key[i].value > v2.key[i].value) {
      return +1 * o;
    } else if (v1.key[i].value < v2.key[i].value) {
      return -1 * o;
    }
  }

  return 0;
}


// Parses and then evaluates the given XPath expression in the given
// input context. Notice that parsed xpath expressions are cached.
function xpathEval(select, context) {
  var expr = xpathParse(select);
  var ret = expr.evaluate(context);
  return ret;
}

// Copyright 2005 Google Inc.
// All Rights Reserved
//
//
// An XSL-T processor written in JavaScript. The implementation is NOT
// complete; some xsl element are left out.
//
// References:
//
// [XSLT] XSL-T Specification
// <http://www.w3.org/TR/1999/REC-xslt-19991116>.
//
// [ECMA] ECMAScript Language Specification
// <http://www.ecma-international.org/publications/standards/Ecma-262.htm>.
//
// The XSL processor API has one entry point, the function
// xsltProcessContext(). It receives as arguments the starting point in the
// input document as an XPath expression context, the DOM root node of
// the XSL-T stylesheet, and a DOM node that receives the output.
//
// NOTE: Actually, XSL-T processing according to the specification is
// defined as operation on text documents, not as operation on DOM
// trees. So, strictly speaking, this implementation is not an XSL-T
// processor, but the processing engine that needs to be complemented
// by an XML parser and serializer in order to be complete. Those two
// are found in the file xml.js.
//
//
// TODO(mesch): add jsdoc comments. Use more coherent naming. Finish
// remaining XSLT features.
//
//
// Author: Steffen Meschkat <mesch@google.com>


// The exported entry point of the XSL-T processor, as explained
// above.
//
// @param xmlDoc The input document root, as DOM node.
// @param template The stylesheet document root, as DOM node.
// @return the processed document, as XML text in a string.

function xsltProcess(xmlDoc, stylesheet) {
  var output = domCreateDocumentFragment(new XDocument);
  xsltProcessContext(new ExprContext(xmlDoc), stylesheet, output);
  var ret = xmlText(output);
  return ret;
}

// The main entry point of the XSL-T processor, as explained above.
//
// @param input The input document root, as XPath ExprContext.
// @param template The stylesheet document root, as DOM node.
// @param the root of the generated output, as DOM node.

function xsltProcessContext(input, template, output) {
  var outputDocument = xmlOwnerDocument(output);

  var nodename = template.nodeName.split(/:/);
  if (nodename.length == 1 || nodename[0] != 'xsl') {
    xsltPassThrough(input, template, output, outputDocument);

  } else {
    switch(nodename[1]) {
    case 'apply-imports':
      alert('not implemented: ' + nodename[1]);
      break;

    case 'apply-templates':
      var select = xmlGetAttribute(template, 'select');
      var nodes;
      if (select) {
        nodes = xpathEval(select,input).nodeSetValue();
      } else {
        nodes = input.node.childNodes;
      }

      var sortContext = input.clone(nodes[0], 0, nodes);
      xsltWithParam(sortContext, template);
      xsltSort(sortContext, template);

      var mode = xmlGetAttribute(template, 'mode');
      var top = template.ownerDocument.documentElement;
      var templates = [];
      for (var i = 0; i < top.childNodes.length; ++i) {
        var c = top.childNodes[i];
        if (c.nodeType == DOM_ELEMENT_NODE &&
            c.nodeName == 'xsl:template' &&
            c.getAttribute('mode') == mode) {
          templates.push(c);
        }
      }
      for (var j = 0; j < sortContext.contextSize(); ++j) {
        var nj = sortContext.nodelist[j];
        for (var i = 0; i < templates.length; ++i) {
          xsltProcessContext(sortContext.clone(nj, j), templates[i], output);
        }
      }
      break;

    case 'attribute':
      var nameexpr = xmlGetAttribute(template, 'name');
      var name = xsltAttributeValue(nameexpr, input);
      var node = domCreateDocumentFragment(outputDocument);
      xsltChildNodes(input, template, node);
      var value = xmlValue(node);
      domSetAttribute(output, name, value);
      break;

    case 'attribute-set':
      alert('not implemented: ' + nodename[1]);
      break;

    case 'call-template':
      var name = xmlGetAttribute(template, 'name');
      var top = template.ownerDocument.documentElement;

      var paramContext = input.clone();
      xsltWithParam(paramContext, template);

      for (var i = 0; i < top.childNodes.length; ++i) {
        var c = top.childNodes[i];
        if (c.nodeType == DOM_ELEMENT_NODE &&
            c.nodeName == 'xsl:template' &&
            domGetAttribute(c, 'name') == name) {
          xsltChildNodes(paramContext, c, output);
          break;
        }
      }
      break;

    case 'choose':
      xsltChoose(input, template, output);
      break;

    case 'comment':
      var node = domCreateDocumentFragment(outputDocument);
      xsltChildNodes(input, template, node);
      var commentData = xmlValue(node);
      var commentNode = domCreateComment(outputDocument, commentData);
      output.appendChild(commentNode);
      break;

    case 'copy':
      var node = xsltCopy(output, input.node, outputDocument);
      if (node) {
        xsltChildNodes(input, template, node);
      }
      break;

    case 'copy-of':
      var select = xmlGetAttribute(template, 'select');
      var value = xpathEval(select, input);
      if (value.type == 'node-set') {
        var nodes = value.nodeSetValue();
        for (var i = 0; i < nodes.length; ++i) {
          xsltCopyOf(output, nodes[i], outputDocument);
        }

      } else {
        var node = domCreateTextNode(outputDocument, value.stringValue());
        domAppendChild(output, node);
      }
      break;

    case 'decimal-format':
      alert('not implemented: ' + nodename[1]);
      break;

    case 'element':
      var nameexpr = xmlGetAttribute(template, 'name');
      var name = xsltAttributeValue(nameexpr, input);
      var node = domCreateElement(outputDocument, name);
      domAppendChild(output, node);
      xsltChildNodes(input, template, node);
      break;

    case 'fallback':
      alert('not implemented: ' + nodename[1]);
      break;

    case 'for-each':
      xsltForEach(input, template, output);
      break;

    case 'if':
      var test = xmlGetAttribute(template, 'test');
      if (xpathEval(test, input).booleanValue()) {
        xsltChildNodes(input, template, output);
      }
      break;

    case 'import':
      alert('not implemented: ' + nodename[1]);
      break;

    case 'include':
      alert('not implemented: ' + nodename[1]);
      break;

    case 'key':
      alert('not implemented: ' + nodename[1]);
      break;

    case 'message':
      alert('not implemented: ' + nodename[1]);
      break;

    case 'namespace-alias':
      alert('not implemented: ' + nodename[1]);
      break;

    case 'number':
      alert('not implemented: ' + nodename[1]);
      break;

    case 'otherwise':
      alert('error if here: ' + nodename[1]);
      break;

    case 'output':
      // Ignored. -- Since we operate on the DOM, and all further use
      // of the output of the XSL transformation is determined by the
      // browser that we run in, this parameter is not applicable to
      // this implementation.
      break;

    case 'preserve-space':
      alert('not implemented: ' + nodename[1]);
      break;

    case 'processing-instruction':
      alert('not implemented: ' + nodename[1]);
      break;

    case 'sort':
      // just ignore -- was handled by xsltSort()
      break;

    case 'strip-space':
      alert('not implemented: ' + nodename[1]);
      break;

    case 'stylesheet':
    case 'transform':
      xsltChildNodes(input, template, output);
      break;

    case 'template':
      var match = xmlGetAttribute(template, 'match');
      if (match && xsltMatch(match, input)) {
        xsltChildNodes(input, template, output);
      }
      break;

    case 'text':
      var text = xmlValue(template);
      var node = domCreateTextNode(outputDocument, text);
      output.appendChild(node);
      break;

    case 'value-of':
      var select = xmlGetAttribute(template, 'select');
      var value = xpathEval(select, input).stringValue();
      var node = domCreateTextNode(outputDocument, value);
      output.appendChild(node);
      break;

    case 'param':
      xsltVariable(input, template, false);
      break;

    case 'variable':
      xsltVariable(input, template, true);
      break;

    case 'when':
      alert('error if here: ' + nodename[1]);
      break;

    case 'with-param':
      alert('error if here: ' + nodename[1]);
      break;

    default:
      alert('error if here: ' + nodename[1]);
      break;
    }
  }
}


// Sets parameters defined by xsl:with-param child nodes of the
// current template node, in the current input context. This happens
// before the operation specified by the current template node is
// executed.

function xsltWithParam(input, template) {
  for (var i = 0; i < template.childNodes.length; ++i) {
    var c = template.childNodes[i];
    if (c.nodeType == DOM_ELEMENT_NODE && c.nodeName == 'xsl:with-param') {
      xsltVariable(input, c, true);
    }
  }
}


// Orders the current node list in the input context according to the
// sort order specified by xsl:sort child nodes of the current
// template node. This happens before the operation specified by the
// current template node is executed.
//
// TODO(mesch): case-order is not implemented.

function xsltSort(input, template) {
  var sort = [];
  for (var i = 0; i < template.childNodes.length; ++i) {
    var c = template.childNodes[i];
    if (c.nodeType == DOM_ELEMENT_NODE && c.nodeName == 'xsl:sort') {
      var select = xmlGetAttribute(c, 'select');
      var expr = xpathParse(select);
      var type = xmlGetAttribute(c, 'data-type') || 'text';
      var order = xmlGetAttribute(c, 'order') || 'ascending';
      sort.push({ expr: expr, type: type, order: order });
    }
  }

  xpathSort(input, sort);
}


// Evaluates a variable or parameter and set it in the current input
// context. Implements xsl:variable, xsl:param, and xsl:with-param.
//
// @param override flag that defines if the value computed here
// overrides the one already in the input context if that is the
// case. I.e. decides if this is a default value or a local
// value. xsl:variable and xsl:with-param override; xsl:param doesn't.

function xsltVariable(input, template, override) {
  var name = xmlGetAttribute(template, 'name');
  var select = xmlGetAttribute(template, 'select');

  var value;

  if (template.childNodes.length > 0) {
    var root = domCreateDocumentFragment(template.ownerDocument);
    xsltChildNodes(input, template, root);
    value = new NodeSetValue([root]);

  } else if (select) {
    value = xpathEval(select, input);

  } else {
    value = new StringValue('');
  }

  if (override || !input.getVariable(name)) {
    input.setVariable(name, value);
  }
}


// Implements xsl:chose and its child nodes xsl:when and
// xsl:otherwise.

function xsltChoose(input, template, output) {
  for (var i = 0; i < template.childNodes.length; ++i) {
    var childNode = template.childNodes[i];
    if (childNode.nodeType != DOM_ELEMENT_NODE) {
      continue;

    } else if (childNode.nodeName == 'xsl:when') {
      var test = xmlGetAttribute(childNode, 'test');
      if (xpathEval(test, input).booleanValue()) {
        xsltChildNodes(input, childNode, output);
        break;
      }

    } else if (childNode.nodeName == 'xsl:otherwise') {
      xsltChildNodes(input, childNode, output);
      break;
    }
  }
}


// Implements xsl:for-each.

function xsltForEach(input, template, output) {
  var select = xmlGetAttribute(template, 'select');
  var nodes = xpathEval(select, input).nodeSetValue();
  var sortContext = input.clone(nodes[0], 0, nodes);
  xsltSort(sortContext, template);
  for (var i = 0; i < sortContext.contextSize(); ++i) {
    var ni = sortContext.nodelist[i];
    xsltChildNodes(sortContext.clone(ni, i), template, output);
  }
}


// Traverses the template node tree. Calls the main processing
// function with the current input context for every child node of the
// current template node.

function xsltChildNodes(input, template, output) {
  // Clone input context to keep variables declared here local to the
  // siblings of the children.
  var context = input.clone();
  for (var i = 0; i < template.childNodes.length; ++i) {
    xsltProcessContext(context, template.childNodes[i], output);
  }
}


// Passes template text to the output. The current template node does
// not specify an XSL-T operation and therefore is appended to the
// output with all its attributes. Then continues traversing the
// template node tree.

function xsltPassThrough(input, template, output, outputDocument) {
  if (template.nodeType == DOM_TEXT_NODE) {
    if (xsltPassText(template)) {
      var node = domCreateTextNode(outputDocument, template.nodeValue);
      domAppendChild(output, node);
    }

  } else if (template.nodeType == DOM_ELEMENT_NODE) {
    var node = domCreateElement(outputDocument, template.nodeName);
    for (var i = 0; i < template.attributes.length; ++i) {
      var a = template.attributes[i];
      if (a) {
        var name = a.nodeName;
        var value = xsltAttributeValue(a.nodeValue, input);
        domSetAttribute(node, name, value);
      }
    }
    domAppendChild(output, node);
    xsltChildNodes(input, template, node);

  } else {
    // This applies also to the DOCUMENT_NODE of the XSL stylesheet,
    // so we don't have to treat it specially.
    xsltChildNodes(input, template, output);
  }
}

// Determines if a text node in the XSLT template document is to be
// stripped according to XSLT whitespace stipping rules.
//
// See [XSLT], section 3.4.
//
// TODO(mesch): Whitespace stripping on the input document is
// currently not implemented.

function xsltPassText(template) {
  if (!template.nodeValue.match(/^\s*$/)) {
    return true;
  }

  var element = template.parentNode;
  if (element.nodeName == 'xsl:text') {
    return true;
  }

  while (element && element.nodeType == DOM_ELEMENT_NODE) {
    var xmlspace = domGetAttribute(element, 'xml:space');
    if (xmlspace) {
      if (xmlspace == 'default') {
        return false;
      } else if (xmlspace == 'preserve') {
        return true;
      }
    }

    element = element.parentNode;
  }

  return false;
}

// Evaluates an XSL-T attribute value template. Attribute value
// templates are attributes on XSL-T elements that contain XPath
// expressions in braces {}. The XSL-T expressions are evaluated in
// the current input context. NOTE(mesch): We are using stringSplit()
// instead of string.split() for IE compatibility, see comment on
// stringSplit().

function xsltAttributeValue(value, context) {
  var parts = stringSplit(value, '{');
  if (parts.length == 1) {
    return value;
  }

  var ret = '';
  for (var i = 0; i < parts.length; ++i) {
    var rp = stringSplit(parts[i], '}');
    if (rp.length != 2) {
      // first literal part of the value
      ret += parts[i];
      continue;
    }

    var val = xpathEval(rp[0], context).stringValue();
    ret += val + rp[1];
  }

  return ret;
}


// Wrapper function to access attribute values of template element
// nodes. Currently this calls xmlResolveEntities because in some DOM
// implementations the return value of node.getAttributeValue()
// contains unresolved XML entities, although the DOM spec requires
// that entity references are resolved by te DOM.
function xmlGetAttribute(node, name) {
  // TODO(mesch): This should not be necessary if the DOM is working
  // correctly. The DOM is responsible for resolving entities, not the
  // application.
  var value = domGetAttribute(node, name);
  if (value) {
    return xmlResolveEntities(value);
  } else {
    return value;
  }
};


// Implements xsl:copy-of for node-set values of the select
// expression. Recurses down the source node tree, which is part of
// the input document.
//
// @param {Node} dst the node being copied to, part of output document,
// @param {Node} src the node being copied, part in input document,
// @param {Document} dstDocument

function xsltCopyOf(dst, src, dstDocument) {
  if (src.nodeType == DOM_DOCUMENT_FRAGMENT_NODE ||
      src.nodeType == DOM_DOCUMENT_NODE) {
    for (var i = 0; i < src.childNodes.length; ++i) {
      arguments.callee(dst, src.childNodes[i], dstDocument);
    }
  } else {
    var node = xsltCopy(dst, src, dstDocument);
    if (node) {
      // This was an element node -- recurse to attributes and
      // children.
      for (var i = 0; i < src.attributes.length; ++i) {
        arguments.callee(node, src.attributes[i], dstDocument);
      }

      for (var i = 0; i < src.childNodes.length; ++i) {
        arguments.callee(node, src.childNodes[i], dstDocument);
      }
    }
  }
}


// Implements xsl:copy for all node types.
//
// @param {Node} dst the node being copied to, part of output document,
// @param {Node} src the node being copied, part in input document,
// @param {Document} dstDocument
// @return {Node|Null} If an element node was created, the element
// node. Otherwise null.

function xsltCopy(dst, src, dstDocument) {
  if (src.nodeType == DOM_ELEMENT_NODE) {
    var node = domCreateElement(dstDocument, src.nodeName);
    domAppendChild(dst, node);
    return node;
  }

  if (src.nodeType == DOM_TEXT_NODE) {
    var node = domCreateTextNode(dstDocument, src.nodeValue);
    domAppendChild(dst, node);

  } else if (src.nodeType == DOM_CDATA_SECTION_NODE) {
    var node = domCreateCDATASection(dstDocument, src.nodeValue);
    domAppendChild(dst, node);

  } else if (src.nodeType == DOM_COMMENT_NODE) {
    var node = domCreateComment(dstDocument, src.nodeValue);
    domAppendChild(dst, node);

  } else if (src.nodeType == DOM_ATTRIBUTE_NODE) {
    domSetAttribute(dst, src.nodeName, src.nodeValue);
  }

  return null;
}


// Evaluates an XPath expression in the current input context as a
// match (see [XSLT] section 5.2, paragraph 1).
function xsltMatch(match, context) {
  var expr = xpathParse(match);

  var ret;
  // Shortcut for the most common case.
  if (expr.steps && !expr.absolute && expr.steps.length == 1 &&
      expr.steps[0].axis == 'child' && expr.steps[0].predicate.length == 0) {
    ret = expr.steps[0].nodetest.evaluate(context).booleanValue();

  } else {

    ret = false;
    var node = context.node;

    while (!ret && node) {
      var result = expr.evaluate(context.clone(node,0,[node])).nodeSetValue();
      for (var i = 0; i < result.length; ++i) {
        if (result[i] == context.node) {
          ret = true;
          break;
        }
      }
      node = node.parentNode;
    }
  }

  return ret;
}