move to tests

3 files changed, 2865 insertions, 0 deletions

diff --git a/tests/test_tools/selenium/core/xpath/dom.js b/tests/test_tools/selenium/core/xpath/dom.js
new file mode 100644
index 00000000..85e0ab08
--- /dev/null
+++ b/tests/test_tools/selenium/core/xpath/dom.js
@@ -0,0 +1,428 @@
+// Copyright 2005 Google Inc.
+// All Rights Reserved
+//
+// An XML parse and a minimal DOM implementation that just supportes
+// the subset of the W3C DOM that is used in the XSLT implementation.
+//
+// References: 
+//
+// [DOM] W3C DOM Level 3 Core Specification
+//       <http://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/>.
+//
+// 
+// Author: Steffen Meschkat <mesch@google.com>
+
+// 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.
+//
+function xmlResolveEntities(s) {
+
+  var parts = stringSplit(s, '&');
+
+  var ret = parts[0];
+  for (var i = 1; i < parts.length; ++i) {
+    var rp = stringSplit(parts[i], ';');
+    if (rp.length == 1) {
+      // no entity reference: just a & but no ;
+      ret += parts[i];
+      continue;
+    }
+    
+    var ch;
+    switch (rp[0]) {
+      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 = window.document.createElement('span');
+        span.innerHTML = '&' + rp[0] + '; ';
+        ch = span.childNodes[0].nodeValue.charAt(0);
+    }
+    ret += ch + rp[1];
+  }
+
+  return ret;
+}
+
+
+// Parses the given XML string with our custom, JavaScript XML parser. Written
+// by Steffen Meschkat (mesch@google.com).
+function xmlParse(xml) {
+  Timer.start('xmlparse');
+  var regex_empty = /\/$/;
+
+  // See also <http://www.w3.org/TR/REC-xml/#sec-common-syn> for
+  // allowed chars in a tag and attribute name. TODO(mesch): the
+  // following is still not completely correct.
+
+  var regex_tagname = /^([\w:-]*)/;
+  var regex_attribute = /([\w:-]+)\s?=\s?('([^\']*)'|"([^\"]*)")/g;
+
+  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);
+
+  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 (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 = xmldoc.createElement(tagname);
+
+      var att;
+      while (att = regex_attribute.exec(tag)) {
+        var val = xmlResolveEntities(att[3] || att[4] || '');
+        node.setAttribute(att[1], val);
+      }
+      
+      if (empty) {
+        parent.appendChild(node);
+      } else {
+        parent.appendChild(node);
+        parent = node;
+        stack.push(node);
+      }
+    }
+
+    if (text && parent != root) {
+      parent.appendChild(xmldoc.createTextNode(text));
+    }
+  }
+
+  Timer.end('xmlparse');
+  return root;
+}
+
+
+// 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, value, owner) {
+  this.attributes = [];
+  this.childNodes = [];
+
+  XNode.init.call(this, type, name, value, 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(new XNode(DOM_ATTRIBUTE_NODE, name, value));
+}
+
+
+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;
+}
+
+
+function XDocument() {
+  XNode.call(this, DOM_DOCUMENT_NODE, '#document', null, this);
+  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);
+}
+
+XNode.prototype.getElementsByTagName = function(name, list) {
+  if (!list) {
+    list = [];
+  }
+
+  if (this.nodeName == name) {
+    list.push(this);
+  }
+
+  for (var i = 0; i < this.childNodes.length; ++i) {
+    this.childNodes[i].getElementsByTagName(name, list);
+  }
+
+  return list;
+}
diff --git a/tests/test_tools/selenium/core/xpath/misc.js b/tests/test_tools/selenium/core/xpath/misc.js
new file mode 100644
index 00000000..b9573a22
--- /dev/null
+++ b/tests/test_tools/selenium/core/xpath/misc.js
@@ -0,0 +1,255 @@
+// Copyright 2005 Google Inc.
+// All Rights Reserved
+//
+// Miscellania that support the ajaxslt implementation.
+//
+// Author: Steffen Meschkat <mesch@google.com>
+//
+
+function el(i) {
+  return document.getElementById(i);
+}
+
+function px(x) {
+  return x + 'px';
+}
+
+// Split 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;
+}
+
+// Returns the text value if 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) {
+  var ret = '';
+  if (node.nodeType == DOM_TEXT_NODE) {
+    ret += xmlEscapeText(node.nodeValue);
+    
+  } else if (node.nodeType == DOM_ELEMENT_NODE) {
+    ret += '<' + node.nodeName;
+    for (var i = 0; i < node.attributes.length; ++i) {
+      var a = node.attributes[i];
+      if (a && a.nodeName && a.nodeValue) {
+        ret += ' ' + a.nodeName;
+        ret += '="' + xmlEscapeAttr(a.nodeValue) + '"';
+      }
+    }
+
+    if (node.childNodes.length == 0) {
+      ret += '/>';
+
+    } else {
+      ret += '>';
+      for (var i = 0; i < node.childNodes.length; ++i) {
+        ret += arguments.callee(node.childNodes[i]);
+      }
+      ret += '</' + node.nodeName + '>';
+    }
+    
+  } else if (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;
+}
+
+// Applies the given function to each element of the array.
+function mapExec(array, func) {
+  for (var i = 0; i < array.length; ++i) {
+    func(array[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;
+  }
+}
+
+// Shallow-copies an array.
+function copyArray(dst, src) { 
+  for (var i = 0; i < src.length; ++i) {
+    dst.push(src[i]);
+  }
+}
+
+function assert(b) {
+  if (!b) {
+    throw 'assertion failed';
+  }
+}
+
+// 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;
+
+
+var xpathdebug = false; // trace xpath parsing
+var xsltdebug = false; // trace xslt processing
+
+
+// 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;');
+}
+
+// An implementation of the debug log. 
+
+var logging__ = false;
+
+function Log() {};
+
+Log.lines = [];
+
+Log.write = function(s) {
+  if (logging__) {
+    this.lines.push(xmlEscapeText(s));
+    this.show();
+  }
+};
+
+// Writes the given XML with every tag on a new line.
+Log.writeXML = function(xml) {
+  if (logging__) {
+    var s0 = xml.replace(/</g, '\n<');
+    var s1 = xmlEscapeText(s0);
+    var s2 = s1.replace(/\s*\n(\s|\n)*/g, '<br/>');
+    this.lines.push(s2);
+    this.show();
+  }
+}
+
+// Writes without any escaping
+Log.writeRaw = function(s) {
+  if (logging__) {
+    this.lines.push(s);
+    this.show();
+  }
+}
+
+Log.clear = function() {
+  if (logging__) {
+    var l = this.div();
+    l.innerHTML = '';
+    this.lines = [];
+  }
+}
+
+Log.show = function() {
+  var l = this.div();
+  l.innerHTML += this.lines.join('<br/>') + '<br/>';
+  this.lines = [];
+  l.scrollTop = l.scrollHeight;
+}
+
+Log.div = function() {
+  var l = document.getElementById('log');
+  if (!l) {
+    l = document.createElement('div');
+    l.id = 'log';
+    l.style.position = 'absolute';
+    l.style.right = '5px';
+    l.style.top = '5px';
+    l.style.width = '250px';
+    l.style.height = '150px';
+    l.style.overflow = 'auto';
+    l.style.backgroundColor = '#f0f0f0';
+    l.style.border = '1px solid gray';
+    l.style.fontSize = '10px';
+    l.style.padding = '5px';
+    document.body.appendChild(l);
+  }
+  return l;
+}
+
+
+function Timer() {}
+Timer.start = function() {}
+Timer.end = function() {}
diff --git a/tests/test_tools/selenium/core/xpath/xpath.js b/tests/test_tools/selenium/core/xpath/xpath.js
new file mode 100644
index 00000000..b93469f2
--- /dev/null
+++ b/tests/test_tools/selenium/core/xpath/xpath.js
@@ -0,0 +1,2182 @@
+// 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.
+//
+//
+// TODO(mesch): add jsdoc comments. Use more coherent naming.
+//
+//
+// 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) {
+  if (xpathdebug) {
+    Log.write('XPath parse ' + expr);
+  }
+  xpathParseInit();
+
+  var cached = xpathCacheLookup(expr);
+  if (cached) {
+    if (xpathdebug) {
+      Log.write(' ... 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+$/i)) {
+    var ret = makeSimpleExpr(expr);
+    xpathParseCache[expr] = ret;
+    if (xpathdebug) {
+      Log.write(' ... simple');
+    }
+    return ret;
+  }
+
+  if (expr.match(/^\w+(\/\w+)*$/i)) {
+    var ret = makeSimpleExpr2(expr);
+    xpathParseCache[expr] = ret;
+    if (xpathdebug) {
+      Log.write(' ... simple 2');
+    }
+    return ret;
+  }
+
+  var cachekey = expr; // expr is modified during parse
+  if (xpathdebug) {
+    Timer.start('XPath parse', cachekey);
+  }
+
+  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);
+      if (xpathdebug) {
+        Log.write('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 {
+      if (xpathdebug) {
+        Log.write('DONE');
+      }
+      done = true;
+    }
+
+    while (xpathReduce(stack, ahead)) {
+      reduce_count++;
+      if (xpathdebug) {
+        Log.write('stack: ' + stackToString(stack));
+      }
+    }
+  }
+
+  if (xpathdebug) {
+    Log.write(stackToString(stack));
+  }
+
+  if (stack.length != 1) {
+    throw 'XPath parse error ' + cachekey + ':\n' + stackToString(stack);
+  }
+
+  var result = stack[0].expr;
+  xpathParseCache[cachekey] = result;
+
+  if (xpathdebug) {
+    Timer.end('XPath parse', cachekey);
+  }
+
+  if (xpathdebug) {
+    Log.write('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();
+    }
+
+    if (xpathdebug) {
+      Log.write('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) {
+      if (xpathdebug) {
+        Log.write('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(node, position) -- sets the context to the new node and
+//   its corresponding 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, position, nodelist, parent) {
+  this.node = node;
+  this.position = position || 0;
+  this.nodelist = nodelist || [ node ];
+  this.variables = {};
+  this.parent = parent || null;
+  this.root = parent ? parent.root : node.ownerDocument;
+}
+
+ExprContext.prototype.clone = function(node, position, nodelist) {
+  return new
+  ExprContext(node || this.node,
+              typeof position != 'undefined' ? position : this.position,
+              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(node, position) {
+  this.node = node;
+  this.position = position;
+}
+
+
+// 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 + ' ' + Error().stack;
+}
+
+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 + ' ' + Error().stack;
+}
+
+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 + ' ' + Error().stack;
+}
+
+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, predicate) {
+  this.axis = axis;
+  this.nodetest = nodetest;
+  this.predicate = 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 = input.parentNode) {
+      nodelist.push(n);
+    }
+
+  } else if (this.axis == xpathAxis.ANCESTOR) {
+    for (var n = input.parentNode; n; n = input.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.parentNode; 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 = input.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.parentNode; 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 = input.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 NodeTestElement() {}
+
+NodeTestElement.prototype.evaluate = function(ctx) {
+  return new BooleanValue(ctx.node.nodeType == DOM_ELEMENT_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;
+  // NOTE (Patrick Lightbody): this change allows node selection to be case-insensitive
+  return new BooleanValue(n.nodeName.toUpperCase() == this.name.toUpperCase());
+}
+
+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 {
+    Log.write('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.nodelist.length);
+  },
+
+  '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.evaluate(ctx);
+    var ret = [];
+    var ids;
+    if (e.type == 'node-set') {
+      ids = [];
+      for (var i = 0; i < e.length; ++i) {
+        var v = xmlValue(e[i]).split(/\s+/);
+        for (var ii = 0; ii < v.length; ++ii) {
+          ids.push(v[ii]);
+        }
+      }
+    } else {
+      ids = e.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-sprintf': function(ctx) {
+    assert(this.args.length >= 1);
+    var args = [];
+    for (var i = 0; i < this.args.length; ++i) {
+      args.push(this.args[i].evaluate(ctx).stringValue());
+    }
+    return new StringValue(sprintf.apply(null, args));
+  },
+
+  // 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) {
+    for (var i1 = 0; i1 < I1; ++i1) {
+      if (nodes1[i1] == nodes2[i2]) {
+        // break inner loop and continue outer loop, labels confuse
+        // the js compiler, so we don't use them here.
+        i1 = I1;
+      }
+    }
+    nodes1.push(nodes2[i2]);
+  }
+  return new NodeSetValue(nodes2);
+};
+
+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 NodeTestElement;
+}
+
+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*\($/, '');
+  if (type != 'processing-instruction') {
+    throw type + ' ' + Error().stack;
+  }
+  return new NodeTestPI(target.value);
+}
+
+function makePredicateExpr(pareno, expr, parenc) {
+  return new PredicateExpr(expr);
+}
+
+function makePrimaryExpr(pareno, expr, parenc) {
+  return expr;
+}
+
+function makeFunctionCallExpr1(name, pareno, parenc) {
+  return new FunctionCallExpr(name);
+}
+
+function makeFunctionCallExpr2(name, pareno, arg1, args, parenc) {
+  var ret = new FunctionCallExpr(name);
+  ret.appendArg(arg1);
+  for (var i = 0; i < args.length; ++i) {
+    ret.appendArg(args[i]);
+  }
+  return ret;
+}
+
+function makeArgumentExpr(comma, expr) {
+  return expr;
+}
+
+function makeUnionExpr(expr1, pipe, expr2) {
+  return new UnionExpr(expr1, expr2);
+}
+
+function makePathExpr1(filter, slash, rel) {
+  return new PathExpr(filter, rel);
+}
+
+function makePathExpr2(filter, dslash, rel) {
+  rel.prependStep(makeAbbrevStep(dslash.value));
+  return new PathExpr(filter, rel);
+}
+
+function makeFilterExpr(expr, predicates) {
+  if (predicates.length > 0) {
+    return new FilterExpr(expr, predicates);
+  } else {
+    return expr;
+  }
+}
+
+function makeUnaryMinusExpr(minus, expr) {
+  return new UnaryMinusExpr(expr);
+}
+
+function makeBinaryExpr(expr1, op, expr2) {
+  return new BinaryExpr(expr1, op, expr2);
+}
+
+function makeLiteralExpr(token) {
+  // remove quotes from the parsed value:
+  var value = token.value.substring(1, token.value.length - 1);
+  return new LiteralExpr(value);
+}
+
+function makeNumberExpr(token) {
+  return new NumberExpr(token.value);
+}
+
+function makeVariableReference(dollar, name) {
+  return new VariableExpr(name.value);
+}
+
+// Used before parsing for optimization of common simple cases. See
+// the begin of xpathParse() for which they are.
+function makeSimpleExpr(expr) {
+  if (expr.charAt(0) == '$') {
+    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 = expr.split('/');
+  var c = new LocationExpr();
+  for (var i in steps) {
+    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('^[a-z][-\\w]*','i') };
+
+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('^([a-z][-\\w]*:)?[a-z][-\\w]*','i')
+};
+
+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++;
+  }
+
+  Log.write('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;
+      }
+    }
+  }
+
+  Log.write('XPath parse INIT: ' + xpathRules.length + ' rule bins');
+  
+  var sum = 0;
+  mapExec(xpathRules, function(i) {
+    if (i) {
+      sum += i.length;
+    }
+  });
+  
+  Log.write('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.nodelist.length; ++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(nodes[0], 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;
+}