/*
*	Copyright (c) 2018 Cameron McCormack 
*	License -> https://github.com/goto100/xpath/blob/master/LICENSE
*	Github -> https://github.com/goto100/xpath
*/
/*
 * xpath.js
 *
 * An XPath 1.0 library for JavaScript.
 *
 * Cameron McCormack <cam (at) mcc.id.au>
 *
 * This work is licensed under the MIT License.
 *
 * Revision 20: April 26, 2011
 *   Fixed a typo resulting in FIRST_ORDERED_NODE_TYPE results being wrong,
 *   thanks to <shi_a009 (at) hotmail.com>.
 *
 * Revision 19: November 29, 2005
 *   Nodesets now store their nodes in a height balanced tree, increasing
 *   performance for the common case of selecting nodes in document order,
 *   thanks to S閎astien Cramatte <contact (at) zeninteractif.com>.
 *   AVL tree code adapted from Raimund Neumann <rnova (at) gmx.net>.
 *
 * Revision 18: October 27, 2005
 *   DOM 3 XPath support.  Caveats:
 *     - namespace prefixes aren't resolved in XPathEvaluator.createExpression,
 *       but in XPathExpression.evaluate.
 *     - XPathResult.invalidIteratorState is not implemented.
 *
 * Revision 17: October 25, 2005
 *   Some core XPath function fixes and a patch to avoid crashing certain
 *   versions of MSXML in PathExpr.prototype.getOwnerElement, thanks to
 *   S閎astien Cramatte <contact (at) zeninteractif.com>.
 *
 * Revision 16: September 22, 2005
 *   Workarounds for some IE 5.5 deficiencies.
 *   Fixed problem with prefix node tests on attribute nodes.
 *
 * Revision 15: May 21, 2005
 *   Fixed problem with QName node tests on elements with an xmlns="...".
 *
 * Revision 14: May 19, 2005
 *   Fixed QName node tests on attribute node regression.
 *
 * Revision 13: May 3, 2005
 *   Node tests are case insensitive now if working in an HTML DOM.
 *
 * Revision 12: April 26, 2005
 *   Updated licence.  Slight code changes to enable use of Dean
 *   Edwards' script compression, http://dean.edwards.name/packer/ .
 *
 * Revision 11: April 23, 2005
 *   Fixed bug with 'and' and 'or' operators, fix thanks to
 *   Sandy McArthur <sandy (at) mcarthur.org>.
 *
 * Revision 10: April 15, 2005
 *   Added support for a virtual root node, supposedly helpful for
 *   implementing XForms.  Fixed problem with QName node tests and
 *   the parent axis.
 *
 * Revision 9: March 17, 2005
 *   Namespace resolver tweaked so using the document node as the context
 *   for namespace lookups is equivalent to using the document element.
 *
 * Revision 8: February 13, 2005
 *   Handle implicit declaration of 'xmlns' namespace prefix.
 *   Fixed bug when comparing nodesets.
 *   Instance data can now be associated with a FunctionResolver, and
 *     workaround for MSXML not supporting 'localName' and 'getElementById',
 *     thanks to Grant Gongaware.
 *   Fix a few problems when the context node is the root node.
 *
 * Revision 7: February 11, 2005
 *   Default namespace resolver fix from Grant Gongaware
 *   <grant (at) gongaware.com>.
 *
 * Revision 6: February 10, 2005
 *   Fixed bug in 'number' function.
 *
 * Revision 5: February 9, 2005
 *   Fixed bug where text nodes not getting converted to string values.
 *
 * Revision 4: January 21, 2005
 *   Bug in 'name' function, fix thanks to Bill Edney.
 *   Fixed incorrect processing of namespace nodes.
 *   Fixed NamespaceResolver to resolve 'xml' namespace.
 *   Implemented union '|' operator.
 *
 * Revision 3: January 14, 2005
 *   Fixed bug with nodeset comparisons, bug lexing < and >.
 *
 * Revision 2: October 26, 2004
 *   QName node test namespace handling fixed.  Few other bug fixes.
 *
 * Revision 1: August 13, 2004
 *   Bug fixes from William J. Edney <bedney (at) technicalpursuit.com>.
 *   Added minimal licence.
 *
 * Initial version: June 14, 2004
 */

// non-node wrapper
var xpath = (typeof exports === 'undefined') ? {} : exports;

(function(exports) {
"use strict";

// functional helpers
function curry( func ) {
    var slice = Array.prototype.slice,
        totalargs = func.length,
        partial = function( args, fn ) {
            return function( ) {
                return fn.apply( this, args.concat( slice.call( arguments ) ) );
            }
        },
        fn = function( ) {
            var args = slice.call( arguments );
            return ( args.length < totalargs ) ?
                partial( args, fn ) :
                func.apply( this, slice.apply( arguments, [ 0, totalargs ] ) );
        };
    return fn;
}

var forEach = curry(function (f, xs) {
	for (var i = 0; i < xs.length; i += 1) {
		f(xs[i], i, xs);
	}
});

var reduce = curry(function (f, seed, xs) {
	var acc = seed;

	forEach(function (x, i) { acc = f(acc, x, i); }, xs);

	return acc;
});

var map = curry(function (f, xs) { 
	var mapped = new Array(xs.length);
	
	forEach(function (x, i) { mapped[i] = f(x); }, xs);

	return mapped;
});

var filter = curry(function (f, xs) {
	var filtered = [];
	
	forEach(function (x, i) { if(f(x, i)) { filtered.push(x); } }, xs);
	
	return filtered;
});

function compose() {
    if (arguments.length === 0) { throw new Error('compose requires at least one argument'); }

    var funcs = Array.prototype.slice.call(arguments).reverse();
	
    var f0 = funcs[0];
    var fRem = funcs.slice(1);

    return function () {
        return reduce(function (acc, next) {
            return next(acc);
        }, f0.apply(null, arguments), fRem);
    };
}

var includes = curry(function (values, value) {
	for (var i = 0; i < values.length; i += 1) {
		if (values[i] === value){
			return true;
		}
	}
	
	return false;
});

function always(value) { return function () { return value ;} }

var prop = curry(function (name, obj) { return obj[name]; });

function toString (x) { return x.toString(); }
var join = curry(function (s, xs) { return xs.join(s); });
var wrap = curry(function (pref, suf, str) { return pref + str + suf; });

function assign(target) { // .length of function is 2
    var to = Object(target);

    for (var index = 1; index < arguments.length; index++) {
        var nextSource = arguments[index];

        if (nextSource != null) { // Skip over if undefined or null
            for (var nextKey in nextSource) {
                // Avoid bugs when hasOwnProperty is shadowed
                if (Object.prototype.hasOwnProperty.call(nextSource, nextKey)) {
                    to[nextKey] = nextSource[nextKey];
                }
            }
        }
    }

    return to;
}

// XPathParser ///////////////////////////////////////////////////////////////

XPathParser.prototype = new Object();
XPathParser.prototype.constructor = XPathParser;
XPathParser.superclass = Object.prototype;

function XPathParser() {
	this.init();
}

XPathParser.prototype.init = function() {
	this.reduceActions = [];

	this.reduceActions[3] = function(rhs) {
		return new OrOperation(rhs[0], rhs[2]);
	};
	this.reduceActions[5] = function(rhs) {
		return new AndOperation(rhs[0], rhs[2]);
	};
	this.reduceActions[7] = function(rhs) {
		return new EqualsOperation(rhs[0], rhs[2]);
	};
	this.reduceActions[8] = function(rhs) {
		return new NotEqualOperation(rhs[0], rhs[2]);
	};
	this.reduceActions[10] = function(rhs) {
		return new LessThanOperation(rhs[0], rhs[2]);
	};
	this.reduceActions[11] = function(rhs) {
		return new GreaterThanOperation(rhs[0], rhs[2]);
	};
	this.reduceActions[12] = function(rhs) {
		return new LessThanOrEqualOperation(rhs[0], rhs[2]);
	};
	this.reduceActions[13] = function(rhs) {
		return new GreaterThanOrEqualOperation(rhs[0], rhs[2]);
	};
	this.reduceActions[15] = function(rhs) {
		return new PlusOperation(rhs[0], rhs[2]);
	};
	this.reduceActions[16] = function(rhs) {
		return new MinusOperation(rhs[0], rhs[2]);
	};
	this.reduceActions[18] = function(rhs) {
		return new MultiplyOperation(rhs[0], rhs[2]);
	};
	this.reduceActions[19] = function(rhs) {
		return new DivOperation(rhs[0], rhs[2]);
	};
	this.reduceActions[20] = function(rhs) {
		return new ModOperation(rhs[0], rhs[2]);
	};
	this.reduceActions[22] = function(rhs) {
		return new UnaryMinusOperation(rhs[1]);
	};
	this.reduceActions[24] = function(rhs) {
		return new BarOperation(rhs[0], rhs[2]);
	};
	this.reduceActions[25] = function(rhs) {
		return new PathExpr(undefined, undefined, rhs[0]);
	};
	this.reduceActions[27] = function(rhs) {
		rhs[0].locationPath = rhs[2];
		return rhs[0];
	};
	this.reduceActions[28] = function(rhs) {
		rhs[0].locationPath = rhs[2];
		rhs[0].locationPath.steps.unshift(new Step(Step.DESCENDANTORSELF, NodeTest.nodeTest, []));
		return rhs[0];
	};
	this.reduceActions[29] = function(rhs) {
		return new PathExpr(rhs[0], [], undefined);
	};
	this.reduceActions[30] = function(rhs) {
		if (Utilities.instance_of(rhs[0], PathExpr)) {
			if (rhs[0].filterPredicates == undefined) {
				rhs[0].filterPredicates = [];
			}
			rhs[0].filterPredicates.push(rhs[1]);
			return rhs[0];
		} else {
			return new PathExpr(rhs[0], [rhs[1]], undefined);
		}
	};
	this.reduceActions[32] = function(rhs) {
		return rhs[1];
	};
	this.reduceActions[33] = function(rhs) {
		return new XString(rhs[0]);
	};
	this.reduceActions[34] = function(rhs) {
		return new XNumber(rhs[0]);
	};
	this.reduceActions[36] = function(rhs) {
		return new FunctionCall(rhs[0], []);
	};
	this.reduceActions[37] = function(rhs) {
		return new FunctionCall(rhs[0], rhs[2]);
	};
	this.reduceActions[38] = function(rhs) {
		return [ rhs[0] ];
	};
	this.reduceActions[39] = function(rhs) {
		rhs[2].unshift(rhs[0]);
		return rhs[2];
	};
	this.reduceActions[43] = function(rhs) {
		return new LocationPath(true, []);
	};
	this.reduceActions[44] = function(rhs) {
		rhs[1].absolute = true;
		return rhs[1];
	};
	this.reduceActions[46] = function(rhs) {
		return new LocationPath(false, [ rhs[0] ]);
	};
	this.reduceActions[47] = function(rhs) {
		rhs[0].steps.push(rhs[2]);
		return rhs[0];
	};
	this.reduceActions[49] = function(rhs) {
		return new Step(rhs[0], rhs[1], []);
	};
	this.reduceActions[50] = function(rhs) {
		return new Step(Step.CHILD, rhs[0], []);
	};
	this.reduceActions[51] = function(rhs) {
		return new Step(rhs[0], rhs[1], rhs[2]);
	};
	this.reduceActions[52] = function(rhs) {
		return new Step(Step.CHILD, rhs[0], rhs[1]);
	};
	this.reduceActions[54] = function(rhs) {
		return [ rhs[0] ];
	};
	this.reduceActions[55] = function(rhs) {
		rhs[1].unshift(rhs[0]);
		return rhs[1];
	};
	this.reduceActions[56] = function(rhs) {
		if (rhs[0] == "ancestor") {
			return Step.ANCESTOR;
		} else if (rhs[0] == "ancestor-or-self") {
			return Step.ANCESTORORSELF;
		} else if (rhs[0] == "attribute") {
			return Step.ATTRIBUTE;
		} else if (rhs[0] == "child") {
			return Step.CHILD;
		} else if (rhs[0] == "descendant") {
			return Step.DESCENDANT;
		} else if (rhs[0] == "descendant-or-self") {
			return Step.DESCENDANTORSELF;
		} else if (rhs[0] == "following") {
			return Step.FOLLOWING;
		} else if (rhs[0] == "following-sibling") {
			return Step.FOLLOWINGSIBLING;
		} else if (rhs[0] == "namespace") {
			return Step.NAMESPACE;
		} else if (rhs[0] == "parent") {
			return Step.PARENT;
		} else if (rhs[0] == "preceding") {
			return Step.PRECEDING;
		} else if (rhs[0] == "preceding-sibling") {
			return Step.PRECEDINGSIBLING;
		} else if (rhs[0] == "self") {
			return Step.SELF;
		}
		return -1;
	};
	this.reduceActions[57] = function(rhs) {
		return Step.ATTRIBUTE;
	};
	this.reduceActions[59] = function(rhs) {
		if (rhs[0] == "comment") {
			return NodeTest.commentTest;
		} else if (rhs[0] == "text") {
			return NodeTest.textTest;
		} else if (rhs[0] == "processing-instruction") {
			return NodeTest.anyPiTest;
		} else if (rhs[0] == "node") {
			return NodeTest.nodeTest;
		}
		return new NodeTest(-1, undefined);
	};
	this.reduceActions[60] = function(rhs) {
		return new NodeTest.PITest(rhs[2]);
	};
	this.reduceActions[61] = function(rhs) {
		return rhs[1];
	};
	this.reduceActions[63] = function(rhs) {
		rhs[1].absolute = true;
		rhs[1].steps.unshift(new Step(Step.DESCENDANTORSELF, NodeTest.nodeTest, []));
		return rhs[1];
	};
	this.reduceActions[64] = function(rhs) {
		rhs[0].steps.push(new Step(Step.DESCENDANTORSELF, NodeTest.nodeTest, []));
		rhs[0].steps.push(rhs[2]);
		return rhs[0];
	};
	this.reduceActions[65] = function(rhs) {
		return new Step(Step.SELF, NodeTest.nodeTest, []);
	};
	this.reduceActions[66] = function(rhs) {
		return new Step(Step.PARENT, NodeTest.nodeTest, []);
	};
	this.reduceActions[67] = function(rhs) {
		return new VariableReference(rhs[1]);
	};
	this.reduceActions[68] = function(rhs) {
		return NodeTest.nameTestAny;
	};
	this.reduceActions[69] = function(rhs) {
		return new NodeTest.NameTestPrefixAny(rhs[0].split(':')[0]);
	};
	this.reduceActions[70] = function(rhs) {
		return new NodeTest.NameTestQName(rhs[0]);
	};
};

XPathParser.actionTable = [
	" s s        sssssssss    s ss  s  ss",
	"                 s                  ",
	"r  rrrrrrrrr         rrrrrrr rr  r  ",
	"                rrrrr               ",
	" s s        sssssssss    s ss  s  ss",
	"rs  rrrrrrrr s  sssssrrrrrr  rrs rs ",
	" s s        sssssssss    s ss  s  ss",
	"                            s       ",
	"                            s       ",
	"r  rrrrrrrrr         rrrrrrr rr rr  ",
	"r  rrrrrrrrr         rrrrrrr rr rr  ",
	"r  rrrrrrrrr         rrrrrrr rr rr  ",
	"r  rrrrrrrrr         rrrrrrr rr rr  ",
	"r  rrrrrrrrr         rrrrrrr rr rr  ",
	"  s                                 ",
	"                            s       ",
	" s           s  sssss          s  s ",
	"r  rrrrrrrrr         rrrrrrr rr  r  ",
	"a                                   ",
	"r       s                    rr  r  ",
	"r      sr                    rr  r  ",
	"r   s  rr            s       rr  r  ",
	"r   rssrr            rss     rr  r  ",
	"r   rrrrr            rrrss   rr  r  ",
	"r   rrrrrsss         rrrrr   rr  r  ",
	"r   rrrrrrrr         rrrrr   rr  r  ",
	"r   rrrrrrrr         rrrrrs  rr  r  ",
	"r   rrrrrrrr         rrrrrr  rr  r  ",
	"r   rrrrrrrr         rrrrrr  rr  r  ",
	"r  srrrrrrrr         rrrrrrs rr sr  ",
	"r  srrrrrrrr         rrrrrrs rr  r  ",
	"r  rrrrrrrrr         rrrrrrr rr rr  ",
	"r  rrrrrrrrr         rrrrrrr rr rr  ",
	"r  rrrrrrrrr         rrrrrrr rr rr  ",
	"r   rrrrrrrr         rrrrrr  rr  r  ",
	"r   rrrrrrrr         rrrrrr  rr  r  ",
	"r  rrrrrrrrr         rrrrrrr rr  r  ",
	"r  rrrrrrrrr         rrrrrrr rr  r  ",
	"                sssss               ",
	"r  rrrrrrrrr         rrrrrrr rr sr  ",
	"r  rrrrrrrrr         rrrrrrr rr  r  ",
	"r  rrrrrrrrr         rrrrrrr rr rr  ",
	"r  rrrrrrrrr         rrrrrrr rr rr  ",
	"                             s      ",
	"r  srrrrrrrr         rrrrrrs rr  r  ",
	"r   rrrrrrrr         rrrrr   rr  r  ",
	"              s                     ",
	"                             s      ",
	"                rrrrr               ",
	" s s        sssssssss    s sss s  ss",
	"r  srrrrrrrr         rrrrrrs rr  r  ",
	" s s        sssssssss    s ss  s  ss",
	" s s        sssssssss    s ss  s  ss",
	" s s        sssssssss    s ss  s  ss",
	" s s        sssssssss    s ss  s  ss",
	" s s        sssssssss    s ss  s  ss",
	" s s        sssssssss    s ss  s  ss",
	" s s        sssssssss    s ss  s  ss",
	" s s        sssssssss    s ss  s  ss",
	" s s        sssssssss    s ss  s  ss",
	" s s        sssssssss    s ss  s  ss",
	" s s        sssssssss    s ss  s  ss",
	" s s        sssssssss    s ss  s  ss",
	" s s        sssssssss    s ss  s  ss",
	" s s        sssssssss      ss  s  ss",
	" s s        sssssssss    s ss  s  ss",
	" s           s  sssss          s  s ",
	" s           s  sssss          s  s ",
	"r  rrrrrrrrr         rrrrrrr rr rr  ",
	" s           s  sssss          s  s ",
	" s           s  sssss          s  s ",
	"r  rrrrrrrrr         rrrrrrr rr sr  ",
	"r  rrrrrrrrr         rrrrrrr rr sr  ",
	"r  rrrrrrrrr         rrrrrrr rr  r  ",
	"r  rrrrrrrrr         rrrrrrr rr rr  ",
	"                             s      ",
	"r  rrrrrrrrr         rrrrrrr rr rr  ",
	"r  rrrrrrrrr         rrrrrrr rr rr  ",
	"                             rr     ",
	"                             s      ",
	"                             rs     ",
	"r      sr                    rr  r  ",
	"r   s  rr            s       rr  r  ",
	"r   rssrr            rss     rr  r  ",
	"r   rssrr            rss     rr  r  ",
	"r   rrrrr            rrrss   rr  r  ",
	"r   rrrrr            rrrss   rr  r  ",
	"r   rrrrr            rrrss   rr  r  ",
	"r   rrrrr            rrrss   rr  r  ",
	"r   rrrrrsss         rrrrr   rr  r  ",
	"r   rrrrrsss         rrrrr   rr  r  ",
	"r   rrrrrrrr         rrrrr   rr  r  ",
	"r   rrrrrrrr         rrrrr   rr  r  ",
	"r   rrrrrrrr         rrrrr   rr  r  ",
	"r   rrrrrrrr         rrrrrr  rr  r  ",
	"                                 r  ",
	"                                 s  ",
	"r  srrrrrrrr         rrrrrrs rr  r  ",
	"r  srrrrrrrr         rrrrrrs rr  r  ",
	"r  rrrrrrrrr         rrrrrrr rr  r  ",
	"r  rrrrrrrrr         rrrrrrr rr  r  ",
	"r  rrrrrrrrr         rrrrrrr rr  r  ",
	"r  rrrrrrrrr         rrrrrrr rr  r  ",
	"r  rrrrrrrrr         rrrrrrr rr rr  ",
	"r  rrrrrrrrr         rrrrrrr rr rr  ",
	" s s        sssssssss    s ss  s  ss",
	"r  rrrrrrrrr         rrrrrrr rr rr  ",
	"                             r      "
];

XPathParser.actionTableNumber = [
	" 1 0        /.-,+*)('    & %$  #  \"!",
	"                 J                  ",
	"a  aaaaaaaaa         aaaaaaa aa  a  ",
	"                YYYYY               ",
	" 1 0        /.-,+*)('    & %$  #  \"!",
	"K1  KKKKKKKK .  +*)('KKKKKK  KK# K\" ",
	" 1 0        /.-,+*)('    & %$  #  \"!",
	"                            N       ",
	"                            O       ",
	"e  eeeeeeeee         eeeeeee ee ee  ",
	"f  fffffffff         fffffff ff ff  ",
	"d  ddddddddd         ddddddd dd dd  ",
	"B  BBBBBBBBB         BBBBBBB BB BB  ",
	"A  AAAAAAAAA         AAAAAAA AA AA  ",
	"  P                                 ",
	"                            Q       ",
	" 1           .  +*)('          #  \" ",
	"b  bbbbbbbbb         bbbbbbb bb  b  ",
	"                                    ",
	"!       S                    !!  !  ",
	"\"      T\"                    \"\"  \"  ",
	"$   V  $$            U       $$  $  ",
	"&   &ZY&&            &XW     &&  &  ",
	")   )))))            )))\\[   ))  )  ",
	".   ....._^]         .....   ..  .  ",
	"1   11111111         11111   11  1  ",
	"5   55555555         55555`  55  5  ",
	"7   77777777         777777  77  7  ",
	"9   99999999         999999  99  9  ",
	":  c::::::::         ::::::b :: a:  ",
	"I  fIIIIIIII         IIIIIIe II  I  ",
	"=  =========         ======= == ==  ",
	"?  ?????????         ??????? ?? ??  ",
	"C  CCCCCCCCC         CCCCCCC CC CC  ",
	"J   JJJJJJJJ         JJJJJJ  JJ  J  ",
	"M   MMMMMMMM         MMMMMM  MM  M  ",
	"N  NNNNNNNNN         NNNNNNN NN  N  ",
	"P  PPPPPPPPP         PPPPPPP PP  P  ",
	"                +*)('               ",
	"R  RRRRRRRRR         RRRRRRR RR aR  ",
	"U  UUUUUUUUU         UUUUUUU UU  U  ",
	"Z  ZZZZZZZZZ         ZZZZZZZ ZZ ZZ  ",
	"c  ccccccccc         ccccccc cc cc  ",
	"                             j      ",
	"L  fLLLLLLLL         LLLLLLe LL  L  ",
	"6   66666666         66666   66  6  ",
	"              k                     ",
	"                             l      ",
	"                XXXXX               ",
	" 1 0        /.-,+*)('    & %$m #  \"!",
	"_  f________         ______e __  _  ",
	" 1 0        /.-,+*)('    & %$  #  \"!",
	" 1 0        /.-,+*)('    & %$  #  \"!",
	" 1 0        /.-,+*)('    & %$  #  \"!",
	" 1 0        /.-,+*)('    & %$  #  \"!",
	" 1 0        /.-,+*)('    & %$  #  \"!",
	" 1 0        /.-,+*)('    & %$  #  \"!",
	" 1 0        /.-,+*)('    & %$  #  \"!",
	" 1 0        /.-,+*)('    & %$  #  \"!",
	" 1 0        /.-,+*)('    & %$  #  \"!",
	" 1 0        /.-,+*)('    & %$  #  \"!",
	" 1 0        /.-,+*)('    & %$  #  \"!",
	" 1 0        /.-,+*)('    & %$  #  \"!",
	" 1 0        /.-,+*)('    & %$  #  \"!",
	" 1 0        /.-,+*)('      %$  #  \"!",
	" 1 0        /.-,+*)('    & %$  #  \"!",
	" 1           .  +*)('          #  \" ",
	" 1           .  +*)('          #  \" ",
	">  >>>>>>>>>         >>>>>>> >> >>  ",
	" 1           .  +*)('          #  \" ",
	" 1           .  +*)('          #  \" ",
	"Q  QQQQQQQQQ         QQQQQQQ QQ aQ  ",
	"V  VVVVVVVVV         VVVVVVV VV aV  ",
	"T  TTTTTTTTT         TTTTTTT TT  T  ",
	"@  @@@@@@@@@         @@@@@@@ @@ @@  ",
	"                             \x87      ",
	"[  [[[[[[[[[         [[[[[[[ [[ [[  ",
	"D  DDDDDDDDD         DDDDDDD DD DD  ",
	"                             HH     ",
	"                             \x88      ",
	"                             F\x89     ",
	"#      T#                    ##  #  ",
	"%   V  %%            U       %%  %  ",
	"'   'ZY''            'XW     ''  '  ",
	"(   (ZY((            (XW     ((  (  ",
	"+   +++++            +++\\[   ++  +  ",
	"*   *****            ***\\[   **  *  ",
	"-   -----            ---\\[   --  -  ",
	",   ,,,,,            ,,,\\[   ,,  ,  ",
	"0   00000_^]         00000   00  0  ",
	"/   /////_^]         /////   //  /  ",
	"2   22222222         22222   22  2  ",
	"3   33333333         33333   33  3  ",
	"4   44444444         44444   44  4  ",
	"8   88888888         888888  88  8  ",
	"                                 ^  ",
	"                                 \x8a  ",
	";  f;;;;;;;;         ;;;;;;e ;;  ;  ",
	"<  f<<<<<<<<         <<<<<<e <<  <  ",
	"O  OOOOOOOOO         OOOOOOO OO  O  ",
	"`  `````````         ``````` ``  `  ",
	"S  SSSSSSSSS         SSSSSSS SS  S  ",
	"W  WWWWWWWWW         WWWWWWW WW  W  ",
	"\\  \\\\\\\\\\\\\\\\\\         \\\\\\\\\\\\\\ \\\\ \\\\  ",
	"E  EEEEEEEEE         EEEEEEE EE EE  ",
	" 1 0        /.-,+*)('    & %$  #  \"!",
	"]  ]]]]]]]]]         ]]]]]]] ]] ]]  ",
	"                             G      "
];

XPathParser.gotoTable = [
	"3456789:;<=>?@ AB  CDEFGH IJ ",
	"                             ",
	"                             ",
	"                             ",
	"L456789:;<=>?@ AB  CDEFGH IJ ",
	"            M        EFGH IJ ",
	"       N;<=>?@ AB  CDEFGH IJ ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"            S        EFGH IJ ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"              e              ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                        h  J ",
	"              i          j   ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"o456789:;<=>?@ ABpqCDEFGH IJ ",
	"                             ",
	"  r6789:;<=>?@ AB  CDEFGH IJ ",
	"   s789:;<=>?@ AB  CDEFGH IJ ",
	"    t89:;<=>?@ AB  CDEFGH IJ ",
	"    u89:;<=>?@ AB  CDEFGH IJ ",
	"     v9:;<=>?@ AB  CDEFGH IJ ",
	"     w9:;<=>?@ AB  CDEFGH IJ ",
	"     x9:;<=>?@ AB  CDEFGH IJ ",
	"     y9:;<=>?@ AB  CDEFGH IJ ",
	"      z:;<=>?@ AB  CDEFGH IJ ",
	"      {:;<=>?@ AB  CDEFGH IJ ",
	"       |;<=>?@ AB  CDEFGH IJ ",
	"       };<=>?@ AB  CDEFGH IJ ",
	"       ~;<=>?@ AB  CDEFGH IJ ",
	"         \x7f=>?@ AB  CDEFGH IJ ",
	"\x80456789:;<=>?@ AB  CDEFGH IJ\x81",
	"            \x82        EFGH IJ ",
	"            \x83        EFGH IJ ",
	"                             ",
	"                     \x84 GH IJ ",
	"                     \x85 GH IJ ",
	"              i          \x86   ",
	"              i          \x87   ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"                             ",
	"o456789:;<=>?@ AB\x8cqCDEFGH IJ ",
	"                             ",
	"                             "
];

XPathParser.productions = [
	[1, 1, 2],
	[2, 1, 3],
	[3, 1, 4],
	[3, 3, 3, -9, 4],
	[4, 1, 5],
	[4, 3, 4, -8, 5],
	[5, 1, 6],
	[5, 3, 5, -22, 6],
	[5, 3, 5, -5, 6],
	[6, 1, 7],
	[6, 3, 6, -23, 7],
	[6, 3, 6, -24, 7],
	[6, 3, 6, -6, 7],
	[6, 3, 6, -7, 7],
	[7, 1, 8],
	[7, 3, 7, -25, 8],
	[7, 3, 7, -26, 8],
	[8, 1, 9],
	[8, 3, 8, -12, 9],
	[8, 3, 8, -11, 9],
	[8, 3, 8, -10, 9],
	[9, 1, 10],
	[9, 2, -26, 9],
	[10, 1, 11],
	[10, 3, 10, -27, 11],
	[11, 1, 12],
	[11, 1, 13],
	[11, 3, 13, -28, 14],
	[11, 3, 13, -4, 14],
	[13, 1, 15],
	[13, 2, 13, 16],
	[15, 1, 17],
	[15, 3, -29, 2, -30],
	[15, 1, -15],
	[15, 1, -16],
	[15, 1, 18],
	[18, 3, -13, -29, -30],
	[18, 4, -13, -29, 19, -30],
	[19, 1, 20],
	[19, 3, 20, -31, 19],
	[20, 1, 2],
	[12, 1, 14],
	[12, 1, 21],
	[21, 1, -28],
	[21, 2, -28, 14],
	[21, 1, 22],
	[14, 1, 23],
	[14, 3, 14, -28, 23],
	[14, 1, 24],
	[23, 2, 25, 26],
	[23, 1, 26],
	[23, 3, 25, 26, 27],
	[23, 2, 26, 27],
	[23, 1, 28],
	[27, 1, 16],
	[27, 2, 16, 27],
	[25, 2, -14, -3],
	[25, 1, -32],
	[26, 1, 29],
	[26, 3, -20, -29, -30],
	[26, 4, -21, -29, -15, -30],
	[16, 3, -33, 30, -34],
	[30, 1, 2],
	[22, 2, -4, 14],
	[24, 3, 14, -4, 23],
	[28, 1, -35],
	[28, 1, -2],
	[17, 2, -36, -18],
	[29, 1, -17],
	[29, 1, -19],
	[29, 1, -18]
];

XPathParser.DOUBLEDOT = 2;
XPathParser.DOUBLECOLON = 3;
XPathParser.DOUBLESLASH = 4;
XPathParser.NOTEQUAL = 5;
XPathParser.LESSTHANOREQUAL = 6;
XPathParser.GREATERTHANOREQUAL = 7;
XPathParser.AND = 8;
XPathParser.OR = 9;
XPathParser.MOD = 10;
XPathParser.DIV = 11;
XPathParser.MULTIPLYOPERATOR = 12;
XPathParser.FUNCTIONNAME = 13;
XPathParser.AXISNAME = 14;
XPathParser.LITERAL = 15;
XPathParser.NUMBER = 16;
XPathParser.ASTERISKNAMETEST = 17;
XPathParser.QNAME = 18;
XPathParser.NCNAMECOLONASTERISK = 19;
XPathParser.NODETYPE = 20;
XPathParser.PROCESSINGINSTRUCTIONWITHLITERAL = 21;
XPathParser.EQUALS = 22;
XPathParser.LESSTHAN = 23;
XPathParser.GREATERTHAN = 24;
XPathParser.PLUS = 25;
XPathParser.MINUS = 26;
XPathParser.BAR = 27;
XPathParser.SLASH = 28;
XPathParser.LEFTPARENTHESIS = 29;
XPathParser.RIGHTPARENTHESIS = 30;
XPathParser.COMMA = 31;
XPathParser.AT = 32;
XPathParser.LEFTBRACKET = 33;
XPathParser.RIGHTBRACKET = 34;
XPathParser.DOT = 35;
XPathParser.DOLLAR = 36;

XPathParser.prototype.tokenize = function(s1) {
	var types = [];
	var values = [];
	var s = s1 + '\0';

	var pos = 0;
	var c = s.charAt(pos++);
	while (1) {
		while (c == ' ' || c == '\t' || c == '\r' || c == '\n') {
			c = s.charAt(pos++);
		}
		if (c == '\0' || pos >= s.length) {
			break;
		}

		if (c == '(') {
			types.push(XPathParser.LEFTPARENTHESIS);
			values.push(c);
			c = s.charAt(pos++);
			continue;
		}
		if (c == ')') {
			types.push(XPathParser.RIGHTPARENTHESIS);
			values.push(c);
			c = s.charAt(pos++);
			continue;
		}
		if (c == '[') {
			types.push(XPathParser.LEFTBRACKET);
			values.push(c);
			c = s.charAt(pos++);
			continue;
		}
		if (c == ']') {
			types.push(XPathParser.RIGHTBRACKET);
			values.push(c);
			c = s.charAt(pos++);
			continue;
		}
		if (c == '@') {
			types.push(XPathParser.AT);
			values.push(c);
			c = s.charAt(pos++);
			continue;
		}
		if (c == ',') {
			types.push(XPathParser.COMMA);
			values.push(c);
			c = s.charAt(pos++);
			continue;
		}
		if (c == '|') {
			types.push(XPathParser.BAR);
			values.push(c);
			c = s.charAt(pos++);
			continue;
		}
		if (c == '+') {
			types.push(XPathParser.PLUS);
			values.push(c);
			c = s.charAt(pos++);
			continue;
		}
		if (c == '-') {
			types.push(XPathParser.MINUS);
			values.push(c);
			c = s.charAt(pos++);
			continue;
		}
		if (c == '=') {
			types.push(XPathParser.EQUALS);
			values.push(c);
			c = s.charAt(pos++);
			continue;
		}
		if (c == '$') {
			types.push(XPathParser.DOLLAR);
			values.push(c);
			c = s.charAt(pos++);
			continue;
		}

		if (c == '.') {
			c = s.charAt(pos++);
			if (c == '.') {
				types.push(XPathParser.DOUBLEDOT);
				values.push("..");
				c = s.charAt(pos++);
				continue;
			}
			if (c >= '0' && c <= '9') {
				var number = "." + c;
				c = s.charAt(pos++);
				while (c >= '0' && c <= '9') {
					number += c;
					c = s.charAt(pos++);
				}
				types.push(XPathParser.NUMBER);
				values.push(number);
				continue;
			}
			types.push(XPathParser.DOT);
			values.push('.');
			continue;
		}

		if (c == '\'' || c == '"') {
			var delimiter = c;
			var literal = "";
			while (pos < s.length && (c = s.charAt(pos)) !== delimiter) {
				literal += c;
                pos += 1;
			}
            if (c !== delimiter) {
                throw XPathException.fromMessage("Unterminated string literal: " + delimiter + literal);
            }
            pos += 1;
			types.push(XPathParser.LITERAL);
			values.push(literal);
			c = s.charAt(pos++);
			continue;
		}

		if (c >= '0' && c <= '9') {
			var number = c;
			c = s.charAt(pos++);
			while (c >= '0' && c <= '9') {
				number += c;
				c = s.charAt(pos++);
			}
			if (c == '.') {
				if (s.charAt(pos) >= '0' && s.charAt(pos) <= '9') {
					number += c;
					number += s.charAt(pos++);
					c = s.charAt(pos++);
					while (c >= '0' && c <= '9') {
						number += c;
						c = s.charAt(pos++);
					}
				}
			}
			types.push(XPathParser.NUMBER);
			values.push(number);
			continue;
		}

		if (c == '*') {
			if (types.length > 0) {
				var last = types[types.length - 1];
				if (last != XPathParser.AT
						&& last != XPathParser.DOUBLECOLON
						&& last != XPathParser.LEFTPARENTHESIS
						&& last != XPathParser.LEFTBRACKET
						&& last != XPathParser.AND
						&& last != XPathParser.OR
						&& last != XPathParser.MOD
						&& last != XPathParser.DIV
						&& last != XPathParser.MULTIPLYOPERATOR
						&& last != XPathParser.SLASH
						&& last != XPathParser.DOUBLESLASH
						&& last != XPathParser.BAR
						&& last != XPathParser.PLUS
						&& last != XPathParser.MINUS
						&& last != XPathParser.EQUALS
						&& last != XPathParser.NOTEQUAL
						&& last != XPathParser.LESSTHAN
						&& last != XPathParser.LESSTHANOREQUAL
						&& last != XPathParser.GREATERTHAN
						&& last != XPathParser.GREATERTHANOREQUAL) {
					types.push(XPathParser.MULTIPLYOPERATOR);
					values.push(c);
					c = s.charAt(pos++);
					continue;
				}
			}
			types.push(XPathParser.ASTERISKNAMETEST);
			values.push(c);
			c = s.charAt(pos++);
			continue;
		}

		if (c == ':') {
			if (s.charAt(pos) == ':') {
				types.push(XPathParser.DOUBLECOLON);
				values.push("::");
				pos++;
				c = s.charAt(pos++);
				continue;
			}
		}

		if (c == '/') {
			c = s.charAt(pos++);
			if (c == '/') {
				types.push(XPathParser.DOUBLESLASH);
				values.push("//");
				c = s.charAt(pos++);
				continue;
			}
			types.push(XPathParser.SLASH);
			values.push('/');
			continue;
		}

		if (c == '!') {
			if (s.charAt(pos) == '=') {
				types.push(XPathParser.NOTEQUAL);
				values.push("!=");
				pos++;
				c = s.charAt(pos++);
				continue;
			}
		}

		if (c == '<') {
			if (s.charAt(pos) == '=') {
				types.push(XPathParser.LESSTHANOREQUAL);
				values.push("<=");
				pos++;
				c = s.charAt(pos++);
				continue;
			}
			types.push(XPathParser.LESSTHAN);
			values.push('<');
			c = s.charAt(pos++);
			continue;
		}

		if (c == '>') {
			if (s.charAt(pos) == '=') {
				types.push(XPathParser.GREATERTHANOREQUAL);
				values.push(">=");
				pos++;
				c = s.charAt(pos++);
				continue;
			}
			types.push(XPathParser.GREATERTHAN);
			values.push('>');
			c = s.charAt(pos++);
			continue;
		}

		if (c == '_' || Utilities.isLetter(c.charCodeAt(0))) {
			var name = c;
			c = s.charAt(pos++);
			while (Utilities.isNCNameChar(c.charCodeAt(0))) {
				name += c;
				c = s.charAt(pos++);
			}
			if (types.length > 0) {
				var last = types[types.length - 1];
				if (last != XPathParser.AT
						&& last != XPathParser.DOUBLECOLON
						&& last != XPathParser.LEFTPARENTHESIS
						&& last != XPathParser.LEFTBRACKET
						&& last != XPathParser.AND
						&& last != XPathParser.OR
						&& last != XPathParser.MOD
						&& last != XPathParser.DIV
						&& last != XPathParser.MULTIPLYOPERATOR
						&& last != XPathParser.SLASH
						&& last != XPathParser.DOUBLESLASH
						&& last != XPathParser.BAR
						&& last != XPathParser.PLUS
						&& last != XPathParser.MINUS
						&& last != XPathParser.EQUALS
						&& last != XPathParser.NOTEQUAL
						&& last != XPathParser.LESSTHAN
						&& last != XPathParser.LESSTHANOREQUAL
						&& last != XPathParser.GREATERTHAN
						&& last != XPathParser.GREATERTHANOREQUAL) {
					if (name == "and") {
						types.push(XPathParser.AND);
						values.push(name);
						continue;
					}
					if (name == "or") {
						types.push(XPathParser.OR);
						values.push(name);
						continue;
					}
					if (name == "mod") {
						types.push(XPathParser.MOD);
						values.push(name);
						continue;
					}
					if (name == "div") {
						types.push(XPathParser.DIV);
						values.push(name);
						continue;
					}
				}
			}
			if (c == ':') {
				if (s.charAt(pos) == '*') {
					types.push(XPathParser.NCNAMECOLONASTERISK);
					values.push(name + ":*");
					pos++;
					c = s.charAt(pos++);
					continue;
				}
				if (s.charAt(pos) == '_' || Utilities.isLetter(s.charCodeAt(pos))) {
					name += ':';
					c = s.charAt(pos++);
					while (Utilities.isNCNameChar(c.charCodeAt(0))) {
						name += c;
						c = s.charAt(pos++);
					}
					if (c == '(') {
						types.push(XPathParser.FUNCTIONNAME);
						values.push(name);
						continue;
					}
					types.push(XPathParser.QNAME);
					values.push(name);
					continue;
				}
				if (s.charAt(pos) == ':') {
					types.push(XPathParser.AXISNAME);
					values.push(name);
					continue;
				}
			}
			if (c == '(') {
				if (name == "comment" || name == "text" || name == "node") {
					types.push(XPathParser.NODETYPE);
					values.push(name);
					continue;
				}
				if (name == "processing-instruction") {
					if (s.charAt(pos) == ')') {
						types.push(XPathParser.NODETYPE);
					} else {
						types.push(XPathParser.PROCESSINGINSTRUCTIONWITHLITERAL);
					}
					values.push(name);
					continue;
				}
				types.push(XPathParser.FUNCTIONNAME);
				values.push(name);
				continue;
			}
			types.push(XPathParser.QNAME);
			values.push(name);
			continue;
		}

		throw new Error("Unexpected character " + c);
	}
	types.push(1);
	values.push("[EOF]");
	return [types, values];
};

XPathParser.SHIFT = 's';
XPathParser.REDUCE = 'r';
XPathParser.ACCEPT = 'a';

XPathParser.prototype.parse = function(s) {
	var types;
	var values;
	var res = this.tokenize(s);
	if (res == undefined) {
		return undefined;
	}
	types = res[0];
	values = res[1];
	var tokenPos = 0;
	var state = [];
	var tokenType = [];
	var tokenValue = [];
	var s;
	var a;
	var t;

	state.push(0);
	tokenType.push(1);
	tokenValue.push("_S");

	a = types[tokenPos];
	t = values[tokenPos++];
	while (1) {
		s = state[state.length - 1];
		switch (XPathParser.actionTable[s].charAt(a - 1)) {
			case XPathParser.SHIFT:
				tokenType.push(-a);
				tokenValue.push(t);
				state.push(XPathParser.actionTableNumber[s].charCodeAt(a - 1) - 32);
				a = types[tokenPos];
				t = values[tokenPos++];
				break;
			case XPathParser.REDUCE:
				var num = XPathParser.productions[XPathParser.actionTableNumber[s].charCodeAt(a - 1) - 32][1];
				var rhs = [];
				for (var i = 0; i < num; i++) {
					tokenType.pop();
					rhs.unshift(tokenValue.pop());
					state.pop();
				}
				var s_ = state[state.length - 1];
				tokenType.push(XPathParser.productions[XPathParser.actionTableNumber[s].charCodeAt(a - 1) - 32][0]);
				if (this.reduceActions[XPathParser.actionTableNumber[s].charCodeAt(a - 1) - 32] == undefined) {
					tokenValue.push(rhs[0]);
				} else {
					tokenValue.push(this.reduceActions[XPathParser.actionTableNumber[s].charCodeAt(a - 1) - 32](rhs));
				}
				state.push(XPathParser.gotoTable[s_].charCodeAt(XPathParser.productions[XPathParser.actionTableNumber[s].charCodeAt(a - 1) - 32][0] - 2) - 33);
				break;
			case XPathParser.ACCEPT:
				return new XPath(tokenValue.pop());
			default:
				throw new Error("XPath parse error");
		}
	}
};

// XPath /////////////////////////////////////////////////////////////////////

XPath.prototype = new Object();
XPath.prototype.constructor = XPath;
XPath.superclass = Object.prototype;

function XPath(e) {
	this.expression = e;
}

XPath.prototype.toString = function() {
	return this.expression.toString();
};

function setIfUnset(obj, prop, value) {
	if (!(prop in obj)) {
		obj[prop] = value;
	}
}

XPath.prototype.evaluate = function(c) {
	c.contextNode = c.expressionContextNode;
	c.contextSize = 1;
	c.contextPosition = 1;

	// [2017-11-25] Removed usage of .implementation.hasFeature() since it does
	//              not reliably detect HTML DOMs (always returns false in xmldom and true in browsers)
	if (c.isHtml) {
		setIfUnset(c, 'caseInsensitive', true);
		setIfUnset(c, 'allowAnyNamespaceForNoPrefix', true);
	}
	
    setIfUnset(c, 'caseInsensitive', false);

	return this.expression.evaluate(c);
};

XPath.XML_NAMESPACE_URI = "http://www.w3.org/XML/1998/namespace";
XPath.XMLNS_NAMESPACE_URI = "http://www.w3.org/2000/xmlns/";

// Expression ////////////////////////////////////////////////////////////////

Expression.prototype = new Object();
Expression.prototype.constructor = Expression;
Expression.superclass = Object.prototype;

function Expression() {
}

Expression.prototype.init = function() {
};

Expression.prototype.toString = function() {
	return "<Expression>";
};

Expression.prototype.evaluate = function(c) {
	throw new Error("Could not evaluate expression.");
};

// UnaryOperation ////////////////////////////////////////////////////////////

UnaryOperation.prototype = new Expression();
UnaryOperation.prototype.constructor = UnaryOperation;
UnaryOperation.superclass = Expression.prototype;

function UnaryOperation(rhs) {
	if (arguments.length > 0) {
		this.init(rhs);
	}
}

UnaryOperation.prototype.init = function(rhs) {
	this.rhs = rhs;
};

// UnaryMinusOperation ///////////////////////////////////////////////////////

UnaryMinusOperation.prototype = new UnaryOperation();
UnaryMinusOperation.prototype.constructor = UnaryMinusOperation;
UnaryMinusOperation.superclass = UnaryOperation.prototype;

function UnaryMinusOperation(rhs) {
	if (arguments.length > 0) {
		this.init(rhs);
	}
}

UnaryMinusOperation.prototype.init = function(rhs) {
	UnaryMinusOperation.superclass.init.call(this, rhs);
};

UnaryMinusOperation.prototype.evaluate = function(c) {
	return this.rhs.evaluate(c).number().negate();
};

UnaryMinusOperation.prototype.toString = function() {
	return "-" + this.rhs.toString();
};

// BinaryOperation ///////////////////////////////////////////////////////////

BinaryOperation.prototype = new Expression();
BinaryOperation.prototype.constructor = BinaryOperation;
BinaryOperation.superclass = Expression.prototype;

function BinaryOperation(lhs, rhs) {
	if (arguments.length > 0) {
		this.init(lhs, rhs);
	}
}

BinaryOperation.prototype.init = function(lhs, rhs) {
	this.lhs = lhs;
	this.rhs = rhs;
};

// OrOperation ///////////////////////////////////////////////////////////////

OrOperation.prototype = new BinaryOperation();
OrOperation.prototype.constructor = OrOperation;
OrOperation.superclass = BinaryOperation.prototype;

function OrOperation(lhs, rhs) {
	if (arguments.length > 0) {
		this.init(lhs, rhs);
	}
}

OrOperation.prototype.init = function(lhs, rhs) {
	OrOperation.superclass.init.call(this, lhs, rhs);
};

OrOperation.prototype.toString = function() {
	return "(" + this.lhs.toString() + " or " + this.rhs.toString() + ")";
};

OrOperation.prototype.evaluate = function(c) {
	var b = this.lhs.evaluate(c).bool();
	if (b.booleanValue()) {
		return b;
	}
	return this.rhs.evaluate(c).bool();
};

// AndOperation //////////////////////////////////////////////////////////////

AndOperation.prototype = new BinaryOperation();
AndOperation.prototype.constructor = AndOperation;
AndOperation.superclass = BinaryOperation.prototype;

function AndOperation(lhs, rhs) {
	if (arguments.length > 0) {
		this.init(lhs, rhs);
	}
}

AndOperation.prototype.init = function(lhs, rhs) {
	AndOperation.superclass.init.call(this, lhs, rhs);
};

AndOperation.prototype.toString = function() {
	return "(" + this.lhs.toString() + " and " + this.rhs.toString() + ")";
};

AndOperation.prototype.evaluate = function(c) {
	var b = this.lhs.evaluate(c).bool();
	if (!b.booleanValue()) {
		return b;
	}
	return this.rhs.evaluate(c).bool();
};

// EqualsOperation ///////////////////////////////////////////////////////////

EqualsOperation.prototype = new BinaryOperation();
EqualsOperation.prototype.constructor = EqualsOperation;
EqualsOperation.superclass = BinaryOperation.prototype;

function EqualsOperation(lhs, rhs) {
	if (arguments.length > 0) {
		this.init(lhs, rhs);
	}
}

EqualsOperation.prototype.init = function(lhs, rhs) {
	EqualsOperation.superclass.init.call(this, lhs, rhs);
};

EqualsOperation.prototype.toString = function() {
	return "(" + this.lhs.toString() + " = " + this.rhs.toString() + ")";
};

EqualsOperation.prototype.evaluate = function(c) {
	return this.lhs.evaluate(c).equals(this.rhs.evaluate(c));
};

// NotEqualOperation /////////////////////////////////////////////////////////

NotEqualOperation.prototype = new BinaryOperation();
NotEqualOperation.prototype.constructor = NotEqualOperation;
NotEqualOperation.superclass = BinaryOperation.prototype;

function NotEqualOperation(lhs, rhs) {
	if (arguments.length > 0) {
		this.init(lhs, rhs);
	}
}

NotEqualOperation.prototype.init = function(lhs, rhs) {
	NotEqualOperation.superclass.init.call(this, lhs, rhs);
};

NotEqualOperation.prototype.toString = function() {
	return "(" + this.lhs.toString() + " != " + this.rhs.toString() + ")";
};

NotEqualOperation.prototype.evaluate = function(c) {
	return this.lhs.evaluate(c).notequal(this.rhs.evaluate(c));
};

// LessThanOperation /////////////////////////////////////////////////////////

LessThanOperation.prototype = new BinaryOperation();
LessThanOperation.prototype.constructor = LessThanOperation;
LessThanOperation.superclass = BinaryOperation.prototype;

function LessThanOperation(lhs, rhs) {
	if (arguments.length > 0) {
		this.init(lhs, rhs);
	}
}

LessThanOperation.prototype.init = function(lhs, rhs) {
	LessThanOperation.superclass.init.call(this, lhs, rhs);
};

LessThanOperation.prototype.evaluate = function(c) {
	return this.lhs.evaluate(c).lessthan(this.rhs.evaluate(c));
};

LessThanOperation.prototype.toString = function() {
	return "(" + this.lhs.toString() + " < " + this.rhs.toString() + ")";
};

// GreaterThanOperation //////////////////////////////////////////////////////

GreaterThanOperation.prototype = new BinaryOperation();
GreaterThanOperation.prototype.constructor = GreaterThanOperation;
GreaterThanOperation.superclass = BinaryOperation.prototype;

function GreaterThanOperation(lhs, rhs) {
	if (arguments.length > 0) {
		this.init(lhs, rhs);
	}
}

GreaterThanOperation.prototype.init = function(lhs, rhs) {
	GreaterThanOperation.superclass.init.call(this, lhs, rhs);
};

GreaterThanOperation.prototype.evaluate = function(c) {
	return this.lhs.evaluate(c).greaterthan(this.rhs.evaluate(c));
};

GreaterThanOperation.prototype.toString = function() {
	return "(" + this.lhs.toString() + " > " + this.rhs.toString() + ")";
};

// LessThanOrEqualOperation //////////////////////////////////////////////////

LessThanOrEqualOperation.prototype = new BinaryOperation();
LessThanOrEqualOperation.prototype.constructor = LessThanOrEqualOperation;
LessThanOrEqualOperation.superclass = BinaryOperation.prototype;

function LessThanOrEqualOperation(lhs, rhs) {
	if (arguments.length > 0) {
		this.init(lhs, rhs);
	}
}

LessThanOrEqualOperation.prototype.init = function(lhs, rhs) {
	LessThanOrEqualOperation.superclass.init.call(this, lhs, rhs);
};

LessThanOrEqualOperation.prototype.evaluate = function(c) {
	return this.lhs.evaluate(c).lessthanorequal(this.rhs.evaluate(c));
};

LessThanOrEqualOperation.prototype.toString = function() {
	return "(" + this.lhs.toString() + " <= " + this.rhs.toString() + ")";
};

// GreaterThanOrEqualOperation ///////////////////////////////////////////////

GreaterThanOrEqualOperation.prototype = new BinaryOperation();
GreaterThanOrEqualOperation.prototype.constructor = GreaterThanOrEqualOperation;
GreaterThanOrEqualOperation.superclass = BinaryOperation.prototype;

function GreaterThanOrEqualOperation(lhs, rhs) {
	if (arguments.length > 0) {
		this.init(lhs, rhs);
	}
}

GreaterThanOrEqualOperation.prototype.init = function(lhs, rhs) {
	GreaterThanOrEqualOperation.superclass.init.call(this, lhs, rhs);
};

GreaterThanOrEqualOperation.prototype.evaluate = function(c) {
	return this.lhs.evaluate(c).greaterthanorequal(this.rhs.evaluate(c));
};

GreaterThanOrEqualOperation.prototype.toString = function() {
	return "(" + this.lhs.toString() + " >= " + this.rhs.toString() + ")";
};

// PlusOperation /////////////////////////////////////////////////////////////

PlusOperation.prototype = new BinaryOperation();
PlusOperation.prototype.constructor = PlusOperation;
PlusOperation.superclass = BinaryOperation.prototype;

function PlusOperation(lhs, rhs) {
	if (arguments.length > 0) {
		this.init(lhs, rhs);
	}
}

PlusOperation.prototype.init = function(lhs, rhs) {
	PlusOperation.superclass.init.call(this, lhs, rhs);
};

PlusOperation.prototype.evaluate = function(c) {
	return this.lhs.evaluate(c).number().plus(this.rhs.evaluate(c).number());
};

PlusOperation.prototype.toString = function() {
	return "(" + this.lhs.toString() + " + " + this.rhs.toString() + ")";
};

// MinusOperation ////////////////////////////////////////////////////////////

MinusOperation.prototype = new BinaryOperation();
MinusOperation.prototype.constructor = MinusOperation;
MinusOperation.superclass = BinaryOperation.prototype;

function MinusOperation(lhs, rhs) {
	if (arguments.length > 0) {
		this.init(lhs, rhs);
	}
}

MinusOperation.prototype.init = function(lhs, rhs) {
	MinusOperation.superclass.init.call(this, lhs, rhs);
};

MinusOperation.prototype.evaluate = function(c) {
	return this.lhs.evaluate(c).number().minus(this.rhs.evaluate(c).number());
};

MinusOperation.prototype.toString = function() {
	return "(" + this.lhs.toString() + " - " + this.rhs.toString() + ")";
};

// MultiplyOperation /////////////////////////////////////////////////////////

MultiplyOperation.prototype = new BinaryOperation();
MultiplyOperation.prototype.constructor = MultiplyOperation;
MultiplyOperation.superclass = BinaryOperation.prototype;

function MultiplyOperation(lhs, rhs) {
	if (arguments.length > 0) {
		this.init(lhs, rhs);
	}
}

MultiplyOperation.prototype.init = function(lhs, rhs) {
	MultiplyOperation.superclass.init.call(this, lhs, rhs);
};

MultiplyOperation.prototype.evaluate = function(c) {
	return this.lhs.evaluate(c).number().multiply(this.rhs.evaluate(c).number());
};

MultiplyOperation.prototype.toString = function() {
	return "(" + this.lhs.toString() + " * " + this.rhs.toString() + ")";
};

// DivOperation //////////////////////////////////////////////////////////////

DivOperation.prototype = new BinaryOperation();
DivOperation.prototype.constructor = DivOperation;
DivOperation.superclass = BinaryOperation.prototype;

function DivOperation(lhs, rhs) {
	if (arguments.length > 0) {
		this.init(lhs, rhs);
	}
}

DivOperation.prototype.init = function(lhs, rhs) {
	DivOperation.superclass.init.call(this, lhs, rhs);
};

DivOperation.prototype.evaluate = function(c) {
	return this.lhs.evaluate(c).number().div(this.rhs.evaluate(c).number());
};

DivOperation.prototype.toString = function() {
	return "(" + this.lhs.toString() + " div " + this.rhs.toString() + ")";
};

// ModOperation //////////////////////////////////////////////////////////////

ModOperation.prototype = new BinaryOperation();
ModOperation.prototype.constructor = ModOperation;
ModOperation.superclass = BinaryOperation.prototype;

function ModOperation(lhs, rhs) {
	if (arguments.length > 0) {
		this.init(lhs, rhs);
	}
}

ModOperation.prototype.init = function(lhs, rhs) {
	ModOperation.superclass.init.call(this, lhs, rhs);
};

ModOperation.prototype.evaluate = function(c) {
	return this.lhs.evaluate(c).number().mod(this.rhs.evaluate(c).number());
};

ModOperation.prototype.toString = function() {
	return "(" + this.lhs.toString() + " mod " + this.rhs.toString() + ")";
};

// BarOperation //////////////////////////////////////////////////////////////

BarOperation.prototype = new BinaryOperation();
BarOperation.prototype.constructor = BarOperation;
BarOperation.superclass = BinaryOperation.prototype;

function BarOperation(lhs, rhs) {
	if (arguments.length > 0) {
		this.init(lhs, rhs);
	}
}

BarOperation.prototype.init = function(lhs, rhs) {
	BarOperation.superclass.init.call(this, lhs, rhs);
};

BarOperation.prototype.evaluate = function(c) {
	return this.lhs.evaluate(c).nodeset().union(this.rhs.evaluate(c).nodeset());
};

BarOperation.prototype.toString = function() {
	return map(toString, [this.lhs, this.rhs]).join(' | ');
};

// PathExpr //////////////////////////////////////////////////////////////////

PathExpr.prototype = new Expression();
PathExpr.prototype.constructor = PathExpr;
PathExpr.superclass = Expression.prototype;

function PathExpr(filter, filterPreds, locpath) {
	if (arguments.length > 0) {
		this.init(filter, filterPreds, locpath);
	}
}

PathExpr.prototype.init = function(filter, filterPreds, locpath) {
	PathExpr.superclass.init.call(this);
	this.filter = filter;
	this.filterPredicates = filterPreds;
	this.locationPath = locpath;
};

/**
 * Returns the topmost node of the tree containing node
 */
function findRoot(node) {
    while (node && node.parentNode) {
        node = node.parentNode;
    }

    return node;
}

PathExpr.applyPredicates = function (predicates, c, nodes) {
	return reduce(function (inNodes, pred) {
		var ctx = c.extend({ contextSize: inNodes.length });
		
		return filter(function (node, i) {
			return PathExpr.predicateMatches(pred, ctx.extend({ contextNode: node, contextPosition: i + 1 }));
		}, inNodes);
	}, nodes, predicates);
};

PathExpr.getRoot = function (xpc, nodes) {
	var firstNode = nodes[0];
	
    if (firstNode.nodeType === 9 /*Node.DOCUMENT_NODE*/) {
		return firstNode;
	}
	
    if (xpc.virtualRoot) {
    	return xpc.virtualRoot;
    }
		
	var ownerDoc = firstNode.ownerDocument;
	
	if (ownerDoc) {
		return ownerDoc;
	}
			
    // IE 5.5 doesn't have ownerDocument?
    var n = firstNode;
    while (n.parentNode != null) {
    	n = n.parentNode;
    }
    return n;
}

PathExpr.applyStep = function (step, xpc, node) {
	var self = this;
	var newNodes = [];
    xpc.contextNode = node;
    
    switch (step.axis) {
    	case Step.ANCESTOR:
    		// look at all the ancestor nodes
    		if (xpc.contextNode === xpc.virtualRoot) {
    			break;
    		}
    		var m;
    		if (xpc.contextNode.nodeType == 2 /*Node.ATTRIBUTE_NODE*/) {
    			m = PathExpr.getOwnerElement(xpc.contextNode);
    		} else {
    			m = xpc.contextNode.parentNode;
    		}
    		while (m != null) {
    			if (step.nodeTest.matches(m, xpc)) {
    				newNodes.push(m);
    			}
    			if (m === xpc.virtualRoot) {
    				break;
    			}
    			m = m.parentNode;
    		}
    		break;
    
    	case Step.ANCESTORORSELF:
    		// look at all the ancestor nodes and the current node
    		for (var m = xpc.contextNode; m != null; m = m.nodeType == 2 /*Node.ATTRIBUTE_NODE*/ ? PathExpr.getOwnerElement(m) : m.parentNode) {
    			if (step.nodeTest.matches(m, xpc)) {
    				newNodes.push(m);
    			}
    			if (m === xpc.virtualRoot) {
    				break;
    			}
    		}
    		break;
    
    	case Step.ATTRIBUTE:
    		// look at the attributes
    		var nnm = xpc.contextNode.attributes;
    		if (nnm != null) {
    			for (var k = 0; k < nnm.length; k++) {
    				var m = nnm.item(k);
    				if (step.nodeTest.matches(m, xpc)) {
    					newNodes.push(m);
    				}
    			}
    		}
    		break;
    
    	case Step.CHILD:
    		// look at all child elements
    		for (var m = xpc.contextNode.firstChild; m != null; m = m.nextSibling) {
    			if (step.nodeTest.matches(m, xpc)) {
    				newNodes.push(m);
    			}
    		}
    		break;
    
    	case Step.DESCENDANT:
    		// look at all descendant nodes
    		var st = [ xpc.contextNode.firstChild ];
    		while (st.length > 0) {
    			for (var m = st.pop(); m != null; ) {
    				if (step.nodeTest.matches(m, xpc)) {
    					newNodes.push(m);
    				}
    				if (m.firstChild != null) {
    					st.push(m.nextSibling);
    					m = m.firstChild;
    				} else {
    					m = m.nextSibling;
    				}
    			}
    		}
    		break;
    
    	case Step.DESCENDANTORSELF:
    		// look at self
    		if (step.nodeTest.matches(xpc.contextNode, xpc)) {
    			newNodes.push(xpc.contextNode);
    		}
    		// look at all descendant nodes
    		var st = [ xpc.contextNode.firstChild ];
    		while (st.length > 0) {
    			for (var m = st.pop(); m != null; ) {
    				if (step.nodeTest.matches(m, xpc)) {
    					newNodes.push(m);
    				}
    				if (m.firstChild != null) {
    					st.push(m.nextSibling);
    					m = m.firstChild;
    				} else {
    					m = m.nextSibling;
    				}
    			}
    		}
    		break;
    
    	case Step.FOLLOWING:
    		if (xpc.contextNode === xpc.virtualRoot) {
    			break;
    		}
    		var st = [];
    		if (xpc.contextNode.firstChild != null) {
    			st.unshift(xpc.contextNode.firstChild);
    		} else {
    			st.unshift(xpc.contextNode.nextSibling);
    		}
    		for (var m = xpc.contextNode.parentNode; m != null && m.nodeType != 9 /*Node.DOCUMENT_NODE*/ && m !== xpc.virtualRoot; m = m.parentNode) {
    			st.unshift(m.nextSibling);
    		}
    		do {
    			for (var m = st.pop(); m != null; ) {
    				if (step.nodeTest.matches(m, xpc)) {
    					newNodes.push(m);
    				}
    				if (m.firstChild != null) {
    					st.push(m.nextSibling);
    					m = m.firstChild;
    				} else {
    					m = m.nextSibling;
    				}
    			}
    		} while (st.length > 0);
    		break;
    
    	case Step.FOLLOWINGSIBLING:
    		if (xpc.contextNode === xpc.virtualRoot) {
    			break;
    		}
    		for (var m = xpc.contextNode.nextSibling; m != null; m = m.nextSibling) {
    			if (step.nodeTest.matches(m, xpc)) {
    				newNodes.push(m);
    			}
    		}
    		break;
    
    	case Step.NAMESPACE:
    		var n = {};
    		if (xpc.contextNode.nodeType == 1 /*Node.ELEMENT_NODE*/) {
    			n["xml"] = XPath.XML_NAMESPACE_URI;
    			n["xmlns"] = XPath.XMLNS_NAMESPACE_URI;
    			for (var m = xpc.contextNode; m != null && m.nodeType == 1 /*Node.ELEMENT_NODE*/; m = m.parentNode) {
    				for (var k = 0; k < m.attributes.length; k++) {
    					var attr = m.attributes.item(k);
    					var nm = String(attr.name);
    					if (nm == "xmlns") {
    						if (n[""] == undefined) {
    							n[""] = attr.value;
    						}
    					} else if (nm.length > 6 && nm.substring(0, 6) == "xmlns:") {
    						var pre = nm.substring(6, nm.length);
    						if (n[pre] == undefined) {
    							n[pre] = attr.value;
    						}
    					}
    				}
    			}
    			for (var pre in n) {
    				var nsn = new XPathNamespace(pre, n[pre], xpc.contextNode);
    				if (step.nodeTest.matches(nsn, xpc)) {
    					newNodes.push(nsn);
    				}
    			}
    		}
    		break;
    
    	case Step.PARENT:
    		m = null;
    		if (xpc.contextNode !== xpc.virtualRoot) {
    			if (xpc.contextNode.nodeType == 2 /*Node.ATTRIBUTE_NODE*/) {
    				m = PathExpr.getOwnerElement(xpc.contextNode);
    			} else {
    				m = xpc.contextNode.parentNode;
    			}
    		}
    		if (m != null && step.nodeTest.matches(m, xpc)) {
    			newNodes.push(m);
    		}
    		break;
    
    	case Step.PRECEDING:
    		var st;
    		if (xpc.virtualRoot != null) {
    			st = [ xpc.virtualRoot ];
    		} else {
                // cannot rely on .ownerDocument because the node may be in a document fragment
                st = [findRoot(xpc.contextNode)];
    		}
    		outer: while (st.length > 0) {
    			for (var m = st.pop(); m != null; ) {
    				if (m == xpc.contextNode) {
    					break outer;
    				}
    				if (step.nodeTest.matches(m, xpc)) {
    					newNodes.unshift(m);
    				}
    				if (m.firstChild != null) {
    					st.push(m.nextSibling);
    					m = m.firstChild;
    				} else {
    					m = m.nextSibling;
    				}
    			}
    		}
    		break;
    
    	case Step.PRECEDINGSIBLING:
    		if (xpc.contextNode === xpc.virtualRoot) {
    			break;
    		}
    		for (var m = xpc.contextNode.previousSibling; m != null; m = m.previousSibling) {
    			if (step.nodeTest.matches(m, xpc)) {
    				newNodes.push(m);
    			}
    		}
    		break;
    
    	case Step.SELF:
    		if (step.nodeTest.matches(xpc.contextNode, xpc)) {
    			newNodes.push(xpc.contextNode);
    		}
    		break;
    
    	default:
    }
	
	return newNodes;
};

PathExpr.applySteps = function (steps, xpc, nodes) {
	return reduce(function (inNodes, step) {
		return [].concat.apply([], map(function (node) {
			return PathExpr.applyPredicates(step.predicates, xpc, PathExpr.applyStep(step, xpc, node));
		}, inNodes));
	}, nodes, steps);
}

PathExpr.prototype.applyFilter = function(c, xpc) {
	if (!this.filter) {
		return { nodes: [ c.contextNode ] };
	}
	
	var ns = this.filter.evaluate(c);

	if (!Utilities.instance_of(ns, XNodeSet)) {
        if (this.filterPredicates != null && this.filterPredicates.length > 0 || this.locationPath != null) {
		    throw new Error("Path expression filter must evaluate to a nodeset if predicates or location path are used");
		}

		return { nonNodes: ns };
	}
	
	return { 
	    nodes: PathExpr.applyPredicates(this.filterPredicates || [], xpc, ns.toUnsortedArray())
	};
};

PathExpr.applyLocationPath = function (locationPath, xpc, nodes) {
	if (!locationPath) {
		return nodes;
	}
	
	var startNodes = locationPath.absolute ? [ PathExpr.getRoot(xpc, nodes) ] : nodes;
		
    return PathExpr.applySteps(locationPath.steps, xpc, startNodes);
};

PathExpr.prototype.evaluate = function(c) {
	var xpc = assign(new XPathContext(), c);
	
    var filterResult = this.applyFilter(c, xpc);
	
	if ('nonNodes' in filterResult) {
		return filterResult.nonNodes;
	}	
	
	var ns = new XNodeSet();
	ns.addArray(PathExpr.applyLocationPath(this.locationPath, xpc, filterResult.nodes));
	return ns;
};

PathExpr.predicateMatches = function(pred, c) {
	var res = pred.evaluate(c);
	
	return Utilities.instance_of(res, XNumber)
		? c.contextPosition == res.numberValue()
		: res.booleanValue();
};

PathExpr.predicateString = compose(wrap('[', ']'), toString);
PathExpr.predicatesString = compose(join(''), map(PathExpr.predicateString));

PathExpr.prototype.toString = function() {
	if (this.filter != undefined) {
		var filterStr = toString(this.filter);

		if (Utilities.instance_of(this.filter, XString)) {
			return wrap("'", "'", filterStr);
		}
		if (this.filterPredicates != undefined && this.filterPredicates.length) {
			return wrap('(', ')', filterStr) + 
			    PathExpr.predicatesString(this.filterPredicates);
		}
		if (this.locationPath != undefined) {
			return filterStr + 
			    (this.locationPath.absolute ? '' : '/') +
				toString(this.locationPath);
		}

		return filterStr;
	}

	return toString(this.locationPath);
};

PathExpr.getOwnerElement = function(n) {
	// DOM 2 has ownerElement
	if (n.ownerElement) {
		return n.ownerElement;
	}
	// DOM 1 Internet Explorer can use selectSingleNode (ironically)
	try {
		if (n.selectSingleNode) {
			return n.selectSingleNode("..");
		}
	} catch (e) {
	}
	// Other DOM 1 implementations must use this egregious search
	var doc = n.nodeType == 9 /*Node.DOCUMENT_NODE*/
			? n
			: n.ownerDocument;
	var elts = doc.getElementsByTagName("*");
	for (var i = 0; i < elts.length; i++) {
		var elt = elts.item(i);
		var nnm = elt.attributes;
		for (var j = 0; j < nnm.length; j++) {
			var an = nnm.item(j);
			if (an === n) {
				return elt;
			}
		}
	}
	return null;
};

// LocationPath //////////////////////////////////////////////////////////////

LocationPath.prototype = new Object();
LocationPath.prototype.constructor = LocationPath;
LocationPath.superclass = Object.prototype;

function LocationPath(abs, steps) {
	if (arguments.length > 0) {
		this.init(abs, steps);
	}
}

LocationPath.prototype.init = function(abs, steps) {
	this.absolute = abs;
	this.steps = steps;
};

LocationPath.prototype.toString = function() {
	return (
	    (this.absolute ? '/' : '') +
		map(toString, this.steps).join('/')
    );
};

// Step //////////////////////////////////////////////////////////////////////

Step.prototype = new Object();
Step.prototype.constructor = Step;
Step.superclass = Object.prototype;

function Step(axis, nodetest, preds) {
	if (arguments.length > 0) {
		this.init(axis, nodetest, preds);
	}
}

Step.prototype.init = function(axis, nodetest, preds) {
	this.axis = axis;
	this.nodeTest = nodetest;
	this.predicates = preds;
};

Step.prototype.toString = function() {
	return Step.STEPNAMES[this.axis] +
        "::" +
        this.nodeTest.toString() +
	    PathExpr.predicatesString(this.predicates);
};


Step.ANCESTOR = 0;
Step.ANCESTORORSELF = 1;
Step.ATTRIBUTE = 2;
Step.CHILD = 3;
Step.DESCENDANT = 4;
Step.DESCENDANTORSELF = 5;
Step.FOLLOWING = 6;
Step.FOLLOWINGSIBLING = 7;
Step.NAMESPACE = 8;
Step.PARENT = 9;
Step.PRECEDING = 10;
Step.PRECEDINGSIBLING = 11;
Step.SELF = 12;

Step.STEPNAMES = reduce(function (acc, x) { return acc[x[0]] = x[1], acc; }, {}, [
	[Step.ANCESTOR, 'ancestor'],
	[Step.ANCESTORORSELF, 'ancestor-or-self'],
	[Step.ATTRIBUTE, 'attribute'],
	[Step.CHILD, 'child'],
	[Step.DESCENDANT, 'descendant'],
	[Step.DESCENDANTORSELF, 'descendant-or-self'],
	[Step.FOLLOWING, 'following'],
	[Step.FOLLOWINGSIBLING, 'following-sibling'],
	[Step.NAMESPACE, 'namespace'],
	[Step.PARENT, 'parent'],
	[Step.PRECEDING, 'preceding'],
	[Step.PRECEDINGSIBLING, 'preceding-sibling'],
	[Step.SELF, 'self']
  ]);
  
// NodeTest //////////////////////////////////////////////////////////////////

NodeTest.prototype = new Object();
NodeTest.prototype.constructor = NodeTest;
NodeTest.superclass = Object.prototype;

function NodeTest(type, value) {
	if (arguments.length > 0) {
		this.init(type, value);
	}
}

NodeTest.prototype.init = function(type, value) {
	this.type = type;
	this.value = value;
};

NodeTest.prototype.toString = function() {
	return "<unknown nodetest type>";
};

NodeTest.prototype.matches = function (n, xpc) {
    console.warn('unknown node test type');
};

NodeTest.NAMETESTANY = 0;
NodeTest.NAMETESTPREFIXANY = 1;
NodeTest.NAMETESTQNAME = 2;
NodeTest.COMMENT = 3;
NodeTest.TEXT = 4;
NodeTest.PI = 5;
NodeTest.NODE = 6;

NodeTest.isNodeType = function (types){
	return compose(includes(types), prop('nodeType'));
};

NodeTest.makeNodeTestType = function (type, members, ctor) {
	var newType = ctor || function () {};
	
	newType.prototype = new NodeTest(members.type);
	newType.prototype.constructor = type;
	
	for (var key in members) {
		newType.prototype[key] = members[key];
	}
	
	return newType;
};
// create invariant node test for certain node types
NodeTest.makeNodeTypeTest = function (type, nodeTypes, stringVal) {
	return new (NodeTest.makeNodeTestType(type, {
		matches: NodeTest.isNodeType(nodeTypes),
		toString: always(stringVal)
	}))();
};

NodeTest.hasPrefix = function (node) {
	return node.prefix || (node.nodeName || node.tagName).indexOf(':') !== -1;
};

NodeTest.isElementOrAttribute = NodeTest.isNodeType([1, 2]);
NodeTest.nameSpaceMatches = function (prefix, xpc, n) {
	var nNamespace = (n.namespaceURI || '');
	
	if (!prefix) { 
	    return !nNamespace || (xpc.allowAnyNamespaceForNoPrefix && !NodeTest.hasPrefix(n)); 
	}
	
    var ns = xpc.namespaceResolver.getNamespace(prefix, xpc.expressionContextNode);

	if (ns == null) {
        throw new Error("Cannot resolve QName " + prefix);
    }

    return ns === nNamespace;
};
NodeTest.localNameMatches = function (localName, xpc, n) {
	var nLocalName = (n.localName || n.nodeName);
	
	return xpc.caseInsensitive
	    ? localName.toLowerCase() === nLocalName.toLowerCase()
		: localName === nLocalName;
};

NodeTest.NameTestPrefixAny = NodeTest.makeNodeTestType(NodeTest.NAMETESTPREFIXANY, {
	matches: function (n, xpc){
        return NodeTest.isElementOrAttribute(n) && 
		    NodeTest.nameSpaceMatches(this.prefix, xpc, n);
	},
	toString: function () {
		return this.prefix + ":*";
	}
}, function (prefix) { this.prefix = prefix; });

NodeTest.NameTestQName = NodeTest.makeNodeTestType(NodeTest.NAMETESTQNAME, {
	matches: function (n, xpc) {
		return NodeTest.isNodeType([1, 2, XPathNamespace.XPATH_NAMESPACE_NODE])(n) &&
		    NodeTest.nameSpaceMatches(this.prefix, xpc, n) &&
            NodeTest.localNameMatches(this.localName, xpc, n);
	},
	toString: function () {
        return this.name;
	}
}, function (name) { 
    var nameParts = name.split(':');
	
	this.name = name;
	this.prefix = nameParts.length > 1 ? nameParts[0] : null;
	this.localName = nameParts[nameParts.length > 1 ? 1 : 0];
});

NodeTest.PITest = NodeTest.makeNodeTestType(NodeTest.PI, {
	matches: function (n, xpc) {
		return NodeTest.isNodeType([7])(n) && (n.target || n.nodeName) === this.name;
	},
	toString: function () {
        return wrap('processing-instruction("', '")', this.name);
	}
}, function (name) { this.name = name; })

// singletons

// elements, attributes, namespaces
NodeTest.nameTestAny = NodeTest.makeNodeTypeTest(NodeTest.NAMETESTANY, [1, 2, XPathNamespace.XPATH_NAMESPACE_NODE], '*');
// text, cdata
NodeTest.textTest = NodeTest.makeNodeTypeTest(NodeTest.TEXT, [3, 4], 'text()');
NodeTest.commentTest = NodeTest.makeNodeTypeTest(NodeTest.COMMENT, [8], 'comment()');
// elements, attributes, text, cdata, PIs, comments, document nodes
NodeTest.nodeTest = NodeTest.makeNodeTypeTest(NodeTest.NODE, [1, 2, 3, 4, 7, 8, 9], 'node()');
NodeTest.anyPiTest = NodeTest.makeNodeTypeTest(NodeTest.PI, [7], 'processing-instruction()');

// VariableReference /////////////////////////////////////////////////////////

VariableReference.prototype = new Expression();
VariableReference.prototype.constructor = VariableReference;
VariableReference.superclass = Expression.prototype;

function VariableReference(v) {
	if (arguments.length > 0) {
		this.init(v);
	}
}

VariableReference.prototype.init = function(v) {
	this.variable = v;
};

VariableReference.prototype.toString = function() {
	return "$" + this.variable;
};

VariableReference.prototype.evaluate = function(c) {
    var parts = Utilities.resolveQName(this.variable, c.namespaceResolver, c.contextNode, false);

    if (parts[0] == null) {
        throw new Error("Cannot resolve QName " + fn);
    }
	var result = c.variableResolver.getVariable(parts[1], parts[0]);
    if (!result) {
        throw XPathException.fromMessage("Undeclared variable: " + this.toString());
    }
    return result;
};

// FunctionCall //////////////////////////////////////////////////////////////

FunctionCall.prototype = new Expression();
FunctionCall.prototype.constructor = FunctionCall;
FunctionCall.superclass = Expression.prototype;

function FunctionCall(fn, args) {
	if (arguments.length > 0) {
		this.init(fn, args);
	}
}

FunctionCall.prototype.init = function(fn, args) {
	this.functionName = fn;
	this.arguments = args;
};

FunctionCall.prototype.toString = function() {
	var s = this.functionName + "(";
	for (var i = 0; i < this.arguments.length; i++) {
		if (i > 0) {
			s += ", ";
		}
		s += this.arguments[i].toString();
	}
	return s + ")";
};

FunctionCall.prototype.evaluate = function(c) {
    var f = FunctionResolver.getFunctionFromContext(this.functionName, c);

    if (!f) {
		throw new Error("Unknown function " + this.functionName);
	}

    var a = [c].concat(this.arguments);
	return f.apply(c.functionResolver.thisArg, a);
};

// Operators /////////////////////////////////////////////////////////////////

var Operators = new Object();

Operators.equals = function(l, r) {
	return l.equals(r);
};

Operators.notequal = function(l, r) {
	return l.notequal(r);
};

Operators.lessthan = function(l, r) {
	return l.lessthan(r);
};

Operators.greaterthan = function(l, r) {
	return l.greaterthan(r);
};

Operators.lessthanorequal = function(l, r) {
	return l.lessthanorequal(r);
};

Operators.greaterthanorequal = function(l, r) {
	return l.greaterthanorequal(r);
};

// XString ///////////////////////////////////////////////////////////////////

XString.prototype = new Expression();
XString.prototype.constructor = XString;
XString.superclass = Expression.prototype;

function XString(s) {
	if (arguments.length > 0) {
		this.init(s);
	}
}

XString.prototype.init = function(s) {
	this.str = String(s);
};

XString.prototype.toString = function() {
	return this.str;
};

XString.prototype.evaluate = function(c) {
	return this;
};

XString.prototype.string = function() {
	return this;
};

XString.prototype.number = function() {
	return new XNumber(this.str);
};

XString.prototype.bool = function() {
	return new XBoolean(this.str);
};

XString.prototype.nodeset = function() {
	throw new Error("Cannot convert string to nodeset");
};

XString.prototype.stringValue = function() {
	return this.str;
};

XString.prototype.numberValue = function() {
	return this.number().numberValue();
};

XString.prototype.booleanValue = function() {
	return this.bool().booleanValue();
};

XString.prototype.equals = function(r) {
	if (Utilities.instance_of(r, XBoolean)) {
		return this.bool().equals(r);
	}
	if (Utilities.instance_of(r, XNumber)) {
		return this.number().equals(r);
	}
	if (Utilities.instance_of(r, XNodeSet)) {
		return r.compareWithString(this, Operators.equals);
	}
	return new XBoolean(this.str == r.str);
};

XString.prototype.notequal = function(r) {
	if (Utilities.instance_of(r, XBoolean)) {
		return this.bool().notequal(r);
	}
	if (Utilities.instance_of(r, XNumber)) {
		return this.number().notequal(r);
	}
	if (Utilities.instance_of(r, XNodeSet)) {
		return r.compareWithString(this, Operators.notequal);
	}
	return new XBoolean(this.str != r.str);
};

XString.prototype.lessthan = function(r) {
	return this.number().lessthan(r);
};

XString.prototype.greaterthan = function(r) {
	return this.number().greaterthan(r);
};

XString.prototype.lessthanorequal = function(r) {
	return this.number().lessthanorequal(r);
};

XString.prototype.greaterthanorequal = function(r) {
	return this.number().greaterthanorequal(r);
};

// XNumber ///////////////////////////////////////////////////////////////////

XNumber.prototype = new Expression();
XNumber.prototype.constructor = XNumber;
XNumber.superclass = Expression.prototype;

function XNumber(n) {
	if (arguments.length > 0) {
		this.init(n);
	}
}

XNumber.prototype.init = function(n) {
	this.num = typeof n === "string" ? this.parse(n) : Number(n);
};

XNumber.prototype.numberFormat = /^\s*-?[0-9]*\.?[0-9]+\s*$/;

XNumber.prototype.parse = function(s) {
    // XPath representation of numbers is more restrictive than what Number() or parseFloat() allow
    return this.numberFormat.test(s) ? parseFloat(s) : Number.NaN;
};

function padSmallNumber(numberStr) {
	var parts = numberStr.split('e-');
	var base = parts[0].replace('.', '');
	var exponent = Number(parts[1]);
	
	for (var i = 0; i < exponent - 1; i += 1) {
		base = '0' + base;
	}
	
	return '0.' + base;
}

function padLargeNumber(numberStr) {
	var parts = numberStr.split('e');
	var base = parts[0].replace('.', '');
	var exponent = Number(parts[1]);
	var zerosToAppend = exponent + 1 - base.length;
	
	for (var i = 0; i < zerosToAppend; i += 1){
		base += '0';
	}
	
	return base;
}

XNumber.prototype.toString = function() {
	var strValue = this.num.toString();

	if (strValue.indexOf('e-') !== -1) {
		return padSmallNumber(strValue);
	}
    
	if (strValue.indexOf('e') !== -1) {
		return padLargeNumber(strValue);
	}
	
	return strValue;
};

XNumber.prototype.evaluate = function(c) {
	return this;
};

XNumber.prototype.string = function() {
	
	
	return new XString(this.toString());
};

XNumber.prototype.number = function() {
	return this;
};

XNumber.prototype.bool = function() {
	return new XBoolean(this.num);
};

XNumber.prototype.nodeset = function() {
	throw new Error("Cannot convert number to nodeset");
};

XNumber.prototype.stringValue = function() {
	return this.string().stringValue();
};

XNumber.prototype.numberValue = function() {
	return this.num;
};

XNumber.prototype.booleanValue = function() {
	return this.bool().booleanValue();
};

XNumber.prototype.negate = function() {
	return new XNumber(-this.num);
};

XNumber.prototype.equals = function(r) {
	if (Utilities.instance_of(r, XBoolean)) {
		return this.bool().equals(r);
	}
	if (Utilities.instance_of(r, XString)) {
		return this.equals(r.number());
	}
	if (Utilities.instance_of(r, XNodeSet)) {
		return r.compareWithNumber(this, Operators.equals);
	}
	return new XBoolean(this.num == r.num);
};

XNumber.prototype.notequal = function(r) {
	if (Utilities.instance_of(r, XBoolean)) {
		return this.bool().notequal(r);
	}
	if (Utilities.instance_of(r, XString)) {
		return this.notequal(r.number());
	}
	if (Utilities.instance_of(r, XNodeSet)) {
		return r.compareWithNumber(this, Operators.notequal);
	}
	return new XBoolean(this.num != r.num);
};

XNumber.prototype.lessthan = function(r) {
	if (Utilities.instance_of(r, XNodeSet)) {
		return r.compareWithNumber(this, Operators.greaterthan);
	}
	if (Utilities.instance_of(r, XBoolean) || Utilities.instance_of(r, XString)) {
		return this.lessthan(r.number());
	}
	return new XBoolean(this.num < r.num);
};

XNumber.prototype.greaterthan = function(r) {
	if (Utilities.instance_of(r, XNodeSet)) {
		return r.compareWithNumber(this, Operators.lessthan);
	}
	if (Utilities.instance_of(r, XBoolean) || Utilities.instance_of(r, XString)) {
		return this.greaterthan(r.number());
	}
	return new XBoolean(this.num > r.num);
};

XNumber.prototype.lessthanorequal = function(r) {
	if (Utilities.instance_of(r, XNodeSet)) {
		return r.compareWithNumber(this, Operators.greaterthanorequal);
	}
	if (Utilities.instance_of(r, XBoolean) || Utilities.instance_of(r, XString)) {
		return this.lessthanorequal(r.number());
	}
	return new XBoolean(this.num <= r.num);
};

XNumber.prototype.greaterthanorequal = function(r) {
	if (Utilities.instance_of(r, XNodeSet)) {
		return r.compareWithNumber(this, Operators.lessthanorequal);
	}
	if (Utilities.instance_of(r, XBoolean) || Utilities.instance_of(r, XString)) {
		return this.greaterthanorequal(r.number());
	}
	return new XBoolean(this.num >= r.num);
};

XNumber.prototype.plus = function(r) {
	return new XNumber(this.num + r.num);
};

XNumber.prototype.minus = function(r) {
	return new XNumber(this.num - r.num);
};

XNumber.prototype.multiply = function(r) {
	return new XNumber(this.num * r.num);
};

XNumber.prototype.div = function(r) {
	return new XNumber(this.num / r.num);
};

XNumber.prototype.mod = function(r) {
	return new XNumber(this.num % r.num);
};

// XBoolean //////////////////////////////////////////////////////////////////

XBoolean.prototype = new Expression();
XBoolean.prototype.constructor = XBoolean;
XBoolean.superclass = Expression.prototype;

function XBoolean(b) {
	if (arguments.length > 0) {
		this.init(b);
	}
}

XBoolean.prototype.init = function(b) {
	this.b = Boolean(b);
};

XBoolean.prototype.toString = function() {
	return this.b.toString();
};

XBoolean.prototype.evaluate = function(c) {
	return this;
};

XBoolean.prototype.string = function() {
	return new XString(this.b);
};

XBoolean.prototype.number = function() {
	return new XNumber(this.b);
};

XBoolean.prototype.bool = function() {
	return this;
};

XBoolean.prototype.nodeset = function() {
	throw new Error("Cannot convert boolean to nodeset");
};

XBoolean.prototype.stringValue = function() {
	return this.string().stringValue();
};

XBoolean.prototype.numberValue = function() {
	return this.number().numberValue();
};

XBoolean.prototype.booleanValue = function() {
	return this.b;
};

XBoolean.prototype.not = function() {
	return new XBoolean(!this.b);
};

XBoolean.prototype.equals = function(r) {
	if (Utilities.instance_of(r, XString) || Utilities.instance_of(r, XNumber)) {
		return this.equals(r.bool());
	}
	if (Utilities.instance_of(r, XNodeSet)) {
		return r.compareWithBoolean(this, Operators.equals);
	}
	return new XBoolean(this.b == r.b);
};

XBoolean.prototype.notequal = function(r) {
	if (Utilities.instance_of(r, XString) || Utilities.instance_of(r, XNumber)) {
		return this.notequal(r.bool());
	}
	if (Utilities.instance_of(r, XNodeSet)) {
		return r.compareWithBoolean(this, Operators.notequal);
	}
	return new XBoolean(this.b != r.b);
};

XBoolean.prototype.lessthan = function(r) {
	return this.number().lessthan(r);
};

XBoolean.prototype.greaterthan = function(r) {
	return this.number().greaterthan(r);
};

XBoolean.prototype.lessthanorequal = function(r) {
	return this.number().lessthanorequal(r);
};

XBoolean.prototype.greaterthanorequal = function(r) {
	return this.number().greaterthanorequal(r);
};

XBoolean.true_ = new XBoolean(true);
XBoolean.false_ = new XBoolean(false);

// AVLTree ///////////////////////////////////////////////////////////////////

AVLTree.prototype = new Object();
AVLTree.prototype.constructor = AVLTree;
AVLTree.superclass = Object.prototype;

function AVLTree(n) {
	this.init(n);
}

AVLTree.prototype.init = function(n) {
	this.left = null;
    this.right = null;
	this.node = n;
	this.depth = 1;
};

AVLTree.prototype.balance = function() {
    var ldepth = this.left  == null ? 0 : this.left.depth;
    var rdepth = this.right == null ? 0 : this.right.depth;

	if (ldepth > rdepth + 1) {
        // LR or LL rotation
        var lldepth = this.left.left  == null ? 0 : this.left.left.depth;
        var lrdepth = this.left.right == null ? 0 : this.left.right.depth;

        if (lldepth < lrdepth) {
            // LR rotation consists of a RR rotation of the left child
            this.left.rotateRR();
            // plus a LL rotation of this node, which happens anyway
        }
        this.rotateLL();
    } else if (ldepth + 1 < rdepth) {
        // RR or RL rorarion
		var rrdepth = this.right.right == null ? 0 : this.right.right.depth;
		var rldepth = this.right.left  == null ? 0 : this.right.left.depth;

        if (rldepth > rrdepth) {
            // RR rotation consists of a LL rotation of the right child
            this.right.rotateLL();
            // plus a RR rotation of this node, which happens anyway
        }
        this.rotateRR();
    }
};

AVLTree.prototype.rotateLL = function() {
    // the left side is too long => rotate from the left (_not_ leftwards)
    var nodeBefore = this.node;
    var rightBefore = this.right;
    this.node = this.left.node;
    this.right = this.left;
    this.left = this.left.left;
    this.right.left = this.right.right;
    this.right.right = rightBefore;
    this.right.node = nodeBefore;
    this.right.updateInNewLocation();
    this.updateInNewLocation();
};

AVLTree.prototype.rotateRR = function() {
    // the right side is too long => rotate from the right (_not_ rightwards)
    var nodeBefore = this.node;
    var leftBefore = this.left;
    this.node = this.right.node;
    this.left = this.right;
    this.right = this.right.right;
    this.left.right = this.left.left;
    this.left.left = leftBefore;
    this.left.node = nodeBefore;
    this.left.updateInNewLocation();
    this.updateInNewLocation();
};

AVLTree.prototype.updateInNewLocation = function() {
    this.getDepthFromChildren();
};

AVLTree.prototype.getDepthFromChildren = function() {
    this.depth = this.node == null ? 0 : 1;
    if (this.left != null) {
        this.depth = this.left.depth + 1;
    }
    if (this.right != null && this.depth <= this.right.depth) {
        this.depth = this.right.depth + 1;
    }
};

function nodeOrder(n1, n2) {
	if (n1 === n2) {
		return 0;
	}

	if (n1.compareDocumentPosition) {
	    var cpos = n1.compareDocumentPosition(n2);

        if (cpos & 0x01) {
            // not in the same document; return an arbitrary result (is there a better way to do this)
            return 1;
        }
        if (cpos & 0x0A) {
            // n2 precedes or contains n1
            return 1;
        }
        if (cpos & 0x14) {
            // n2 follows or is contained by n1
            return -1;
        }

	    return 0;
	}

	var d1 = 0,
	    d2 = 0;
	for (var m1 = n1; m1 != null; m1 = m1.parentNode || m1.ownerElement) {
		d1++;
	}
	for (var m2 = n2; m2 != null; m2 = m2.parentNode || m2.ownerElement) {
		d2++;
	}

    // step up to same depth
	if (d1 > d2) {
		while (d1 > d2) {
			n1 = n1.parentNode || n1.ownerElement;
			d1--;
		}
		if (n1 === n2) {
			return 1;
		}
	} else if (d2 > d1) {
		while (d2 > d1) {
			n2 = n2.parentNode || n2.ownerElement;
			d2--;
		}
		if (n1 === n2) {
			return -1;
		}
	}

    var n1Par = n1.parentNode || n1.ownerElement,
        n2Par = n2.parentNode || n2.ownerElement;

    // find common parent
	while (n1Par !== n2Par) {
		n1 = n1Par;
		n2 = n2Par;
		n1Par = n1.parentNode || n1.ownerElement;
	    n2Par = n2.parentNode || n2.ownerElement;
	}
    
    var n1isAttr = Utilities.isAttribute(n1);
    var n2isAttr = Utilities.isAttribute(n2);
    
    if (n1isAttr && !n2isAttr) {
        return -1;
    }
    if (!n1isAttr && n2isAttr) {
        return 1;
    }
    
    if(n1Par) {
	    var cn = n1isAttr ? n1Par.attributes : n1Par.childNodes,
	        len = cn.length;
        for (var i = 0; i < len; i += 1) {
            var n = cn[i];
            if (n === n1) {
                return -1;
            }
            if (n === n2) {
                return 1;
            }
        }
    }        
    
    throw new Error('Unexpected: could not determine node order');
}

AVLTree.prototype.add = function(n)  {
	if (n === this.node) {
        return false;
    }

	var o = nodeOrder(n, this.node);

    var ret = false;
    if (o == -1) {
        if (this.left == null) {
            this.left = new AVLTree(n);
            ret = true;
        } else {
            ret = this.left.add(n);
            if (ret) {
                this.balance();
            }
        }
    } else if (o == 1) {
        if (this.right == null) {
            this.right = new AVLTree(n);
            ret = true;
        } else {
            ret = this.right.add(n);
            if (ret) {
                this.balance();
            }
        }
    }

    if (ret) {
        this.getDepthFromChildren();
    }
    return ret;
};

// XNodeSet //////////////////////////////////////////////////////////////////

XNodeSet.prototype = new Expression();
XNodeSet.prototype.constructor = XNodeSet;
XNodeSet.superclass = Expression.prototype;

function XNodeSet() {
	this.init();
}

XNodeSet.prototype.init = function() {
    this.tree = null;
	this.nodes = [];
	this.size = 0;
};

XNodeSet.prototype.toString = function() {
	var p = this.first();
	if (p == null) {
		return "";
	}
	return this.stringForNode(p);
};

XNodeSet.prototype.evaluate = function(c) {
	return this;
};

XNodeSet.prototype.string = function() {
	return new XString(this.toString());
};

XNodeSet.prototype.stringValue = function() {
	return this.toString();
};

XNodeSet.prototype.number = function() {
	return new XNumber(this.string());
};

XNodeSet.prototype.numberValue = function() {
	return Number(this.string());
};

XNodeSet.prototype.bool = function() {
	return new XBoolean(this.booleanValue());
};

XNodeSet.prototype.booleanValue = function() {
	return !!this.size;
};

XNodeSet.prototype.nodeset = function() {
	return this;
};

XNodeSet.prototype.stringForNode = function(n) {
	if (n.nodeType == 9   /*Node.DOCUMENT_NODE*/ || 
        n.nodeType == 1   /*Node.ELEMENT_NODE */ || 
        n.nodeType === 11 /*Node.DOCUMENT_FRAGMENT*/) {
		return this.stringForContainerNode(n);
	}
    if (n.nodeType === 2 /* Node.ATTRIBUTE_NODE */) {
        return n.value || n.nodeValue;
    }
	if (n.isNamespaceNode) {
		return n.namespace;
	}
	return n.nodeValue;
};

XNodeSet.prototype.stringForContainerNode = function(n) {
	var s = "";
	for (var n2 = n.firstChild; n2 != null; n2 = n2.nextSibling) {
        var nt = n2.nodeType;
        //  Element,    Text,       CDATA,      Document,   Document Fragment
        if (nt === 1 || nt === 3 || nt === 4 || nt === 9 || nt === 11) {
            s += this.stringForNode(n2);
        }
	}
	return s;
};

XNodeSet.prototype.buildTree = function () {
    if (!this.tree && this.nodes.length) {
        this.tree = new AVLTree(this.nodes[0]);
        for (var i = 1; i < this.nodes.length; i += 1) {
            this.tree.add(this.nodes[i]);
        }
    }

    return this.tree;
};

XNodeSet.prototype.first = function() {
	var p = this.buildTree();
	if (p == null) {
		return null;
	}
	while (p.left != null) {
		p = p.left;
	}
	return p.node;
};

XNodeSet.prototype.add = function(n) {
    for (var i = 0; i < this.nodes.length; i += 1) {
        if (n === this.nodes[i]) {
            return;
        }
    }

    this.tree = null;
    this.nodes.push(n);
    this.size += 1;
};

XNodeSet.prototype.addArray = function(ns) {
	var self = this;
	
	forEach(function (x) { self.add(x); }, ns);
};

/**
 * Returns an array of the node set's contents in document order
 */
XNodeSet.prototype.toArray = function() {
	var a = [];
	this.toArrayRec(this.buildTree(), a);
	return a;
};

XNodeSet.prototype.toArrayRec = function(t, a) {
	if (t != null) {
		this.toArrayRec(t.left, a);
		a.push(t.node);
		this.toArrayRec(t.right, a);
	}
};

/**
 * Returns an array of the node set's contents in arbitrary order
 */
XNodeSet.prototype.toUnsortedArray = function () {
    return this.nodes.slice();
};

XNodeSet.prototype.compareWithString = function(r, o) {
	var a = this.toUnsortedArray();
	for (var i = 0; i < a.length; i++) {
		var n = a[i];
		var l = new XString(this.stringForNode(n));
		var res = o(l, r);
		if (res.booleanValue()) {
			return res;
		}
	}
	return new XBoolean(false);
};

XNodeSet.prototype.compareWithNumber = function(r, o) {
	var a = this.toUnsortedArray();
	for (var i = 0; i < a.length; i++) {
		var n = a[i];
		var l = new XNumber(this.stringForNode(n));
		var res = o(l, r);
		if (res.booleanValue()) {
			return res;
		}
	}
	return new XBoolean(false);
};

XNodeSet.prototype.compareWithBoolean = function(r, o) {
	return o(this.bool(), r);
};

XNodeSet.prototype.compareWithNodeSet = function(r, o) {
	var arr = this.toUnsortedArray();
	var oInvert = function (lop, rop) { return o(rop, lop); };
	
	for (var i = 0; i < arr.length; i++) {
		var l = new XString(this.stringForNode(arr[i]));

		var res = r.compareWithString(l, oInvert);
		if (res.booleanValue()) {
			return res;
		}
	}
	
	return new XBoolean(false);
};

XNodeSet.compareWith = curry(function (o, r) {
	if (Utilities.instance_of(r, XString)) {
		return this.compareWithString(r, o);
	}
	if (Utilities.instance_of(r, XNumber)) {
		return this.compareWithNumber(r, o);
	}
	if (Utilities.instance_of(r, XBoolean)) {
		return this.compareWithBoolean(r, o);
	}
	return this.compareWithNodeSet(r, o);
});

XNodeSet.prototype.equals = XNodeSet.compareWith(Operators.equals);
XNodeSet.prototype.notequal = XNodeSet.compareWith(Operators.notequal);
XNodeSet.prototype.lessthan = XNodeSet.compareWith(Operators.lessthan);
XNodeSet.prototype.greaterthan = XNodeSet.compareWith(Operators.greaterthan);
XNodeSet.prototype.lessthanorequal = XNodeSet.compareWith(Operators.lessthanorequal);
XNodeSet.prototype.greaterthanorequal = XNodeSet.compareWith(Operators.greaterthanorequal);

XNodeSet.prototype.union = function(r) {
	var ns = new XNodeSet();
    ns.addArray(this.toUnsortedArray());
	ns.addArray(r.toUnsortedArray());
	return ns;
};

// XPathNamespace ////////////////////////////////////////////////////////////

XPathNamespace.prototype = new Object();
XPathNamespace.prototype.constructor = XPathNamespace;
XPathNamespace.superclass = Object.prototype;

function XPathNamespace(pre, ns, p) {
	this.isXPathNamespace = true;
	this.ownerDocument = p.ownerDocument;
	this.nodeName = "#namespace";
	this.prefix = pre;
	this.localName = pre;
	this.namespaceURI = ns;
	this.nodeValue = ns;
	this.ownerElement = p;
	this.nodeType = XPathNamespace.XPATH_NAMESPACE_NODE;
}

XPathNamespace.prototype.toString = function() {
	return "{ \"" + this.prefix + "\", \"" + this.namespaceURI + "\" }";
};

// XPathContext //////////////////////////////////////////////////////////////

XPathContext.prototype = new Object();
XPathContext.prototype.constructor = XPathContext;
XPathContext.superclass = Object.prototype;

function XPathContext(vr, nr, fr) {
	this.variableResolver = vr != null ? vr : new VariableResolver();
	this.namespaceResolver = nr != null ? nr : new NamespaceResolver();
	this.functionResolver = fr != null ? fr : new FunctionResolver();
}

XPathContext.prototype.extend = function (newProps) {
	return assign(new XPathContext(), this, newProps);
};

// VariableResolver //////////////////////////////////////////////////////////

VariableResolver.prototype = new Object();
VariableResolver.prototype.constructor = VariableResolver;
VariableResolver.superclass = Object.prototype;

function VariableResolver() {
}

VariableResolver.prototype.getVariable = function(ln, ns) {
	return null;
};

// FunctionResolver //////////////////////////////////////////////////////////

FunctionResolver.prototype = new Object();
FunctionResolver.prototype.constructor = FunctionResolver;
FunctionResolver.superclass = Object.prototype;

function FunctionResolver(thisArg) {
	this.thisArg = thisArg != null ? thisArg : Functions;
	this.functions = new Object();
	this.addStandardFunctions();
}

FunctionResolver.prototype.addStandardFunctions = function() {
	this.functions["{}last"] = Functions.last;
	this.functions["{}position"] = Functions.position;
	this.functions["{}count"] = Functions.count;
	this.functions["{}id"] = Functions.id;
	this.functions["{}local-name"] = Functions.localName;
	this.functions["{}namespace-uri"] = Functions.namespaceURI;
	this.functions["{}name"] = Functions.name;
	this.functions["{}string"] = Functions.string;
	this.functions["{}concat"] = Functions.concat;
	this.functions["{}starts-with"] = Functions.startsWith;
	this.functions["{}contains"] = Functions.contains;
	this.functions["{}substring-before"] = Functions.substringBefore;
	this.functions["{}substring-after"] = Functions.substringAfter;
	this.functions["{}substring"] = Functions.substring;
	this.functions["{}string-length"] = Functions.stringLength;
	this.functions["{}normalize-space"] = Functions.normalizeSpace;
	this.functions["{}translate"] = Functions.translate;
	this.functions["{}boolean"] = Functions.boolean_;
	this.functions["{}not"] = Functions.not;
	this.functions["{}true"] = Functions.true_;
	this.functions["{}false"] = Functions.false_;
	this.functions["{}lang"] = Functions.lang;
	this.functions["{}number"] = Functions.number;
	this.functions["{}sum"] = Functions.sum;
	this.functions["{}floor"] = Functions.floor;
	this.functions["{}ceiling"] = Functions.ceiling;
	this.functions["{}round"] = Functions.round;
};

FunctionResolver.prototype.addFunction = function(ns, ln, f) {
	this.functions["{" + ns + "}" + ln] = f;
};

FunctionResolver.getFunctionFromContext = function(qName, context) {
    var parts = Utilities.resolveQName(qName, context.namespaceResolver, context.contextNode, false);

    if (parts[0] === null) {
        throw new Error("Cannot resolve QName " + name);
    }

    return context.functionResolver.getFunction(parts[1], parts[0]);
};

FunctionResolver.prototype.getFunction = function(localName, namespace) {
	return this.functions["{" + namespace + "}" + localName];
};

// NamespaceResolver /////////////////////////////////////////////////////////

NamespaceResolver.prototype = new Object();
NamespaceResolver.prototype.constructor = NamespaceResolver;
NamespaceResolver.superclass = Object.prototype;

function NamespaceResolver() {
}

NamespaceResolver.prototype.getNamespace = function(prefix, n) {
	if (prefix == "xml") {
		return XPath.XML_NAMESPACE_URI;
	} else if (prefix == "xmlns") {
		return XPath.XMLNS_NAMESPACE_URI;
	}
	if (n.nodeType == 9 /*Node.DOCUMENT_NODE*/) {
		n = n.documentElement;
	} else if (n.nodeType == 2 /*Node.ATTRIBUTE_NODE*/) {
		n = PathExpr.getOwnerElement(n);
	} else if (n.nodeType != 1 /*Node.ELEMENT_NODE*/) {
		n = n.parentNode;
	}
	while (n != null && n.nodeType == 1 /*Node.ELEMENT_NODE*/) {
		var nnm = n.attributes;
		for (var i = 0; i < nnm.length; i++) {
			var a = nnm.item(i);
			var aname = a.name || a.nodeName;
			if ((aname === "xmlns" && prefix === "")
					|| aname === "xmlns:" + prefix) {
				return String(a.value || a.nodeValue);
			}
		}
		n = n.parentNode;
	}
	return null;
};

// Functions /////////////////////////////////////////////////////////////////

var Functions = new Object();

Functions.last = function(c) {
	if (arguments.length != 1) {
		throw new Error("Function last expects ()");
	}

	return new XNumber(c.contextSize);
};

Functions.position = function(c) {
	if (arguments.length != 1) {
		throw new Error("Function position expects ()");
	}

	return new XNumber(c.contextPosition);
};

Functions.count = function() {
	var c = arguments[0];
	var ns;
	if (arguments.length != 2 || !Utilities.instance_of(ns = arguments[1].evaluate(c), XNodeSet)) {
		throw new Error("Function count expects (node-set)");
	}
	return new XNumber(ns.size);
};

Functions.id = function() {
	var c = arguments[0];
	var id;
	if (arguments.length != 2) {
		throw new Error("Function id expects (object)");
	}
	id = arguments[1].evaluate(c);
	if (Utilities.instance_of(id, XNodeSet)) {
		id = id.toArray().join(" ");
	} else {
		id = id.stringValue();
	}
	var ids = id.split(/[\x0d\x0a\x09\x20]+/);
	var count = 0;
	var ns = new XNodeSet();
	var doc = c.contextNode.nodeType == 9 /*Node.DOCUMENT_NODE*/
			? c.contextNode
			: c.contextNode.ownerDocument;
	for (var i = 0; i < ids.length; i++) {
		var n;
		if (doc.getElementById) {
			n = doc.getElementById(ids[i]);
		} else {
			n = Utilities.getElementById(doc, ids[i]);
		}
		if (n != null) {
			ns.add(n);
			count++;
		}
	}
	return ns;
};

Functions.localName = function(c, eNode) {
	var n;
	
	if (arguments.length == 1) {
		n = c.contextNode;
	} else if (arguments.length == 2) {
		n = eNode.evaluate(c).first();
	} else {
		throw new Error("Function local-name expects (node-set?)");
	}
	
	if (n == null) {
		return new XString("");
	}

	return new XString(n.localName ||     //  standard elements and attributes
	                   n.baseName  ||     //  IE
					   n.target    ||     //  processing instructions
                       n.nodeName  ||     //  DOM1 elements
					   "");               //  fallback
};

Functions.namespaceURI = function() {
	var c = arguments[0];
	var n;
	if (arguments.length == 1) {
		n = c.contextNode;
	} else if (arguments.length == 2) {
		n = arguments[1].evaluate(c).first();
	} else {
		throw new Error("Function namespace-uri expects (node-set?)");
	}
	if (n == null) {
		return new XString("");
	}
	return new XString(n.namespaceURI);
};

Functions.name = function() {
	var c = arguments[0];
	var n;
	if (arguments.length == 1) {
		n = c.contextNode;
	} else if (arguments.length == 2) {
		n = arguments[1].evaluate(c).first();
	} else {
		throw new Error("Function name expects (node-set?)");
	}
	if (n == null) {
		return new XString("");
	}
	if (n.nodeType == 1 /*Node.ELEMENT_NODE*/) {
		return new XString(n.nodeName);
	} else if (n.nodeType == 2 /*Node.ATTRIBUTE_NODE*/) {
		return new XString(n.name || n.nodeName);
	} else if (n.nodeType === 7 /*Node.PROCESSING_INSTRUCTION_NODE*/) {
	    return new XString(n.target || n.nodeName);
	} else if (n.localName == null) {
		return new XString("");
	} else {
		return new XString(n.localName);
	}
};

Functions.string = function() {
	var c = arguments[0];
	if (arguments.length == 1) {
		return new XString(XNodeSet.prototype.stringForNode(c.contextNode));
	} else if (arguments.length == 2) {
		return arguments[1].evaluate(c).string();
	}
	throw new Error("Function string expects (object?)");
};

Functions.concat = function(c) {
	if (arguments.length < 3) {
		throw new Error("Function concat expects (string, string[, string]*)");
	}
	var s = "";
	for (var i = 1; i < arguments.length; i++) {
		s += arguments[i].evaluate(c).stringValue();
	}
	return new XString(s);
};

Functions.startsWith = function() {
	var c = arguments[0];
	if (arguments.length != 3) {
		throw new Error("Function startsWith expects (string, string)");
	}
	var s1 = arguments[1].evaluate(c).stringValue();
	var s2 = arguments[2].evaluate(c).stringValue();
	return new XBoolean(s1.substring(0, s2.length) == s2);
};

Functions.contains = function() {
	var c = arguments[0];
	if (arguments.length != 3) {
		throw new Error("Function contains expects (string, string)");
	}
	var s1 = arguments[1].evaluate(c).stringValue();
	var s2 = arguments[2].evaluate(c).stringValue();
	return new XBoolean(s1.indexOf(s2) !== -1);
};

Functions.substringBefore = function() {
	var c = arguments[0];
	if (arguments.length != 3) {
		throw new Error("Function substring-before expects (string, string)");
	}
	var s1 = arguments[1].evaluate(c).stringValue();
	var s2 = arguments[2].evaluate(c).stringValue();
	return new XString(s1.substring(0, s1.indexOf(s2)));
};

Functions.substringAfter = function() {
	var c = arguments[0];
	if (arguments.length != 3) {
		throw new Error("Function substring-after expects (string, string)");
	}
	var s1 = arguments[1].evaluate(c).stringValue();
	var s2 = arguments[2].evaluate(c).stringValue();
	if (s2.length == 0) {
		return new XString(s1);
	}
	var i = s1.indexOf(s2);
	if (i == -1) {
		return new XString("");
	}
	return new XString(s1.substring(i + s2.length));
};

Functions.substring = function() {
	var c = arguments[0];
	if (!(arguments.length == 3 || arguments.length == 4)) {
		throw new Error("Function substring expects (string, number, number?)");
	}
	var s = arguments[1].evaluate(c).stringValue();
	var n1 = Math.round(arguments[2].evaluate(c).numberValue()) - 1;
	var n2 = arguments.length == 4 ? n1 + Math.round(arguments[3].evaluate(c).numberValue()) : undefined;
	return new XString(s.substring(n1, n2));
};

Functions.stringLength = function() {
	var c = arguments[0];
	var s;
	if (arguments.length == 1) {
		s = XNodeSet.prototype.stringForNode(c.contextNode);
	} else if (arguments.length == 2) {
		s = arguments[1].evaluate(c).stringValue();
	} else {
		throw new Error("Function string-length expects (string?)");
	}
	return new XNumber(s.length);
};

Functions.normalizeSpace = function() {
	var c = arguments[0];
	var s;
	if (arguments.length == 1) {
		s = XNodeSet.prototype.stringForNode(c.contextNode);
	} else if (arguments.length == 2) {
		s = arguments[1].evaluate(c).stringValue();
	} else {
		throw new Error("Function normalize-space expects (string?)");
	}
	var i = 0;
	var j = s.length - 1;
	while (Utilities.isSpace(s.charCodeAt(j))) {
		j--;
	}
	var t = "";
	while (i <= j && Utilities.isSpace(s.charCodeAt(i))) {
		i++;
	}
	while (i <= j) {
		if (Utilities.isSpace(s.charCodeAt(i))) {
			t += " ";
			while (i <= j && Utilities.isSpace(s.charCodeAt(i))) {
				i++;
			}
		} else {
			t += s.charAt(i);
			i++;
		}
	}
	return new XString(t);
};

Functions.translate = function(c, eValue, eFrom, eTo) {
	if (arguments.length != 4) {
		throw new Error("Function translate expects (string, string, string)");
	}

	var value = eValue.evaluate(c).stringValue();
	var from = eFrom.evaluate(c).stringValue();
	var to = eTo.evaluate(c).stringValue();
	
	var cMap = reduce(function (acc, ch, i) {
		if (!(ch in acc)) {
			acc[ch] = i > to.length ? '' : to[i];
		}
		return acc;
	}, {}, from);

    var t = join('', map(function (ch) {
        return ch in cMap ? cMap[ch] : ch;
    }, value));

	return new XString(t);
};

Functions.boolean_ = function() {
	var c = arguments[0];
	if (arguments.length != 2) {
		throw new Error("Function boolean expects (object)");
	}
	return arguments[1].evaluate(c).bool();
};

Functions.not = function(c, eValue) {
	if (arguments.length != 2) {
		throw new Error("Function not expects (object)");
	}
	return eValue.evaluate(c).bool().not();
};

Functions.true_ = function() {
	if (arguments.length != 1) {
		throw new Error("Function true expects ()");
	}
	return XBoolean.true_;
};

Functions.false_ = function() {
	if (arguments.length != 1) {
		throw new Error("Function false expects ()");
	}
	return XBoolean.false_;
};

Functions.lang = function() {
	var c = arguments[0];
	if (arguments.length != 2) {
		throw new Error("Function lang expects (string)");
	}
	var lang;
	for (var n = c.contextNode; n != null && n.nodeType != 9 /*Node.DOCUMENT_NODE*/; n = n.parentNode) {
		var a = n.getAttributeNS(XPath.XML_NAMESPACE_URI, "lang");
		if (a != null) {
			lang = String(a);
			break;
		}
	}
	if (lang == null) {
		return XBoolean.false_;
	}
	var s = arguments[1].evaluate(c).stringValue();
	return new XBoolean(lang.substring(0, s.length) == s
				&& (lang.length == s.length || lang.charAt(s.length) == '-'));
};

Functions.number = function() {
	var c = arguments[0];
	if (!(arguments.length == 1 || arguments.length == 2)) {
		throw new Error("Function number expects (object?)");
	}
	if (arguments.length == 1) {
		return new XNumber(XNodeSet.prototype.stringForNode(c.contextNode));
	}
	return arguments[1].evaluate(c).number();
};

Functions.sum = function() {
	var c = arguments[0];
	var ns;
	if (arguments.length != 2 || !Utilities.instance_of((ns = arguments[1].evaluate(c)), XNodeSet)) {
		throw new Error("Function sum expects (node-set)");
	}
	ns = ns.toUnsortedArray();
	var n = 0;
	for (var i = 0; i < ns.length; i++) {
		n += new XNumber(XNodeSet.prototype.stringForNode(ns[i])).numberValue();
	}
	return new XNumber(n);
};

Functions.floor = function() {
	var c = arguments[0];
	if (arguments.length != 2) {
		throw new Error("Function floor expects (number)");
	}
	return new XNumber(Math.floor(arguments[1].evaluate(c).numberValue()));
};

Functions.ceiling = function() {
	var c = arguments[0];
	if (arguments.length != 2) {
		throw new Error("Function ceiling expects (number)");
	}
	return new XNumber(Math.ceil(arguments[1].evaluate(c).numberValue()));
};

Functions.round = function() {
	var c = arguments[0];
	if (arguments.length != 2) {
		throw new Error("Function round expects (number)");
	}
	return new XNumber(Math.round(arguments[1].evaluate(c).numberValue()));
};

// Utilities /////////////////////////////////////////////////////////////////

var Utilities = new Object();

Utilities.isAttribute = function (val) {
    return val && (val.nodeType === 2 || val.ownerElement);
}

Utilities.splitQName = function(qn) {
	var i = qn.indexOf(":");
	if (i == -1) {
		return [ null, qn ];
	}
	return [ qn.substring(0, i), qn.substring(i + 1) ];
};

Utilities.resolveQName = function(qn, nr, n, useDefault) {
	var parts = Utilities.splitQName(qn);
	if (parts[0] != null) {
		parts[0] = nr.getNamespace(parts[0], n);
	} else {
		if (useDefault) {
			parts[0] = nr.getNamespace("", n);
			if (parts[0] == null) {
				parts[0] = "";
			}
		} else {
			parts[0] = "";
		}
	}
	return parts;
};

Utilities.isSpace = function(c) {
	return c == 0x9 || c == 0xd || c == 0xa || c == 0x20;
};

Utilities.isLetter = function(c) {
	return c >= 0x0041 && c <= 0x005A ||
		c >= 0x0061 && c <= 0x007A ||
		c >= 0x00C0 && c <= 0x00D6 ||
		c >= 0x00D8 && c <= 0x00F6 ||
		c >= 0x00F8 && c <= 0x00FF ||
		c >= 0x0100 && c <= 0x0131 ||
		c >= 0x0134 && c <= 0x013E ||
		c >= 0x0141 && c <= 0x0148 ||
		c >= 0x014A && c <= 0x017E ||
		c >= 0x0180 && c <= 0x01C3 ||
		c >= 0x01CD && c <= 0x01F0 ||
		c >= 0x01F4 && c <= 0x01F5 ||
		c >= 0x01FA && c <= 0x0217 ||
		c >= 0x0250 && c <= 0x02A8 ||
		c >= 0x02BB && c <= 0x02C1 ||
		c == 0x0386 ||
		c >= 0x0388 && c <= 0x038A ||
		c == 0x038C ||
		c >= 0x038E && c <= 0x03A1 ||
		c >= 0x03A3 && c <= 0x03CE ||
		c >= 0x03D0 && c <= 0x03D6 ||
		c == 0x03DA ||
		c == 0x03DC ||
		c == 0x03DE ||
		c == 0x03E0 ||
		c >= 0x03E2 && c <= 0x03F3 ||
		c >= 0x0401 && c <= 0x040C ||
		c >= 0x040E && c <= 0x044F ||
		c >= 0x0451 && c <= 0x045C ||
		c >= 0x045E && c <= 0x0481 ||
		c >= 0x0490 && c <= 0x04C4 ||
		c >= 0x04C7 && c <= 0x04C8 ||
		c >= 0x04CB && c <= 0x04CC ||
		c >= 0x04D0 && c <= 0x04EB ||
		c >= 0x04EE && c <= 0x04F5 ||
		c >= 0x04F8 && c <= 0x04F9 ||
		c >= 0x0531 && c <= 0x0556 ||
		c == 0x0559 ||
		c >= 0x0561 && c <= 0x0586 ||
		c >= 0x05D0 && c <= 0x05EA ||
		c >= 0x05F0 && c <= 0x05F2 ||
		c >= 0x0621 && c <= 0x063A ||
		c >= 0x0641 && c <= 0x064A ||
		c >= 0x0671 && c <= 0x06B7 ||
		c >= 0x06BA && c <= 0x06BE ||
		c >= 0x06C0 && c <= 0x06CE ||
		c >= 0x06D0 && c <= 0x06D3 ||
		c == 0x06D5 ||
		c >= 0x06E5 && c <= 0x06E6 ||
		c >= 0x0905 && c <= 0x0939 ||
		c == 0x093D ||
		c >= 0x0958 && c <= 0x0961 ||
		c >= 0x0985 && c <= 0x098C ||
		c >= 0x098F && c <= 0x0990 ||
		c >= 0x0993 && c <= 0x09A8 ||
		c >= 0x09AA && c <= 0x09B0 ||
		c == 0x09B2 ||
		c >= 0x09B6 && c <= 0x09B9 ||
		c >= 0x09DC && c <= 0x09DD ||
		c >= 0x09DF && c <= 0x09E1 ||
		c >= 0x09F0 && c <= 0x09F1 ||
		c >= 0x0A05 && c <= 0x0A0A ||
		c >= 0x0A0F && c <= 0x0A10 ||
		c >= 0x0A13 && c <= 0x0A28 ||
		c >= 0x0A2A && c <= 0x0A30 ||
		c >= 0x0A32 && c <= 0x0A33 ||
		c >= 0x0A35 && c <= 0x0A36 ||
		c >= 0x0A38 && c <= 0x0A39 ||
		c >= 0x0A59 && c <= 0x0A5C ||
		c == 0x0A5E ||
		c >= 0x0A72 && c <= 0x0A74 ||
		c >= 0x0A85 && c <= 0x0A8B ||
		c == 0x0A8D ||
		c >= 0x0A8F && c <= 0x0A91 ||
		c >= 0x0A93 && c <= 0x0AA8 ||
		c >= 0x0AAA && c <= 0x0AB0 ||
		c >= 0x0AB2 && c <= 0x0AB3 ||
		c >= 0x0AB5 && c <= 0x0AB9 ||
		c == 0x0ABD ||
		c == 0x0AE0 ||
		c >= 0x0B05 && c <= 0x0B0C ||
		c >= 0x0B0F && c <= 0x0B10 ||
		c >= 0x0B13 && c <= 0x0B28 ||
		c >= 0x0B2A && c <= 0x0B30 ||
		c >= 0x0B32 && c <= 0x0B33 ||
		c >= 0x0B36 && c <= 0x0B39 ||
		c == 0x0B3D ||
		c >= 0x0B5C && c <= 0x0B5D ||
		c >= 0x0B5F && c <= 0x0B61 ||
		c >= 0x0B85 && c <= 0x0B8A ||
		c >= 0x0B8E && c <= 0x0B90 ||
		c >= 0x0B92 && c <= 0x0B95 ||
		c >= 0x0B99 && c <= 0x0B9A ||
		c == 0x0B9C ||
		c >= 0x0B9E && c <= 0x0B9F ||
		c >= 0x0BA3 && c <= 0x0BA4 ||
		c >= 0x0BA8 && c <= 0x0BAA ||
		c >= 0x0BAE && c <= 0x0BB5 ||
		c >= 0x0BB7 && c <= 0x0BB9 ||
		c >= 0x0C05 && c <= 0x0C0C ||
		c >= 0x0C0E && c <= 0x0C10 ||
		c >= 0x0C12 && c <= 0x0C28 ||
		c >= 0x0C2A && c <= 0x0C33 ||
		c >= 0x0C35 && c <= 0x0C39 ||
		c >= 0x0C60 && c <= 0x0C61 ||
		c >= 0x0C85 && c <= 0x0C8C ||
		c >= 0x0C8E && c <= 0x0C90 ||
		c >= 0x0C92 && c <= 0x0CA8 ||
		c >= 0x0CAA && c <= 0x0CB3 ||
		c >= 0x0CB5 && c <= 0x0CB9 ||
		c == 0x0CDE ||
		c >= 0x0CE0 && c <= 0x0CE1 ||
		c >= 0x0D05 && c <= 0x0D0C ||
		c >= 0x0D0E && c <= 0x0D10 ||
		c >= 0x0D12 && c <= 0x0D28 ||
		c >= 0x0D2A && c <= 0x0D39 ||
		c >= 0x0D60 && c <= 0x0D61 ||
		c >= 0x0E01 && c <= 0x0E2E ||
		c == 0x0E30 ||
		c >= 0x0E32 && c <= 0x0E33 ||
		c >= 0x0E40 && c <= 0x0E45 ||
		c >= 0x0E81 && c <= 0x0E82 ||
		c == 0x0E84 ||
		c >= 0x0E87 && c <= 0x0E88 ||
		c == 0x0E8A ||
		c == 0x0E8D ||
		c >= 0x0E94 && c <= 0x0E97 ||
		c >= 0x0E99 && c <= 0x0E9F ||
		c >= 0x0EA1 && c <= 0x0EA3 ||
		c == 0x0EA5 ||
		c == 0x0EA7 ||
		c >= 0x0EAA && c <= 0x0EAB ||
		c >= 0x0EAD && c <= 0x0EAE ||
		c == 0x0EB0 ||
		c >= 0x0EB2 && c <= 0x0EB3 ||
		c == 0x0EBD ||
		c >= 0x0EC0 && c <= 0x0EC4 ||
		c >= 0x0F40 && c <= 0x0F47 ||
		c >= 0x0F49 && c <= 0x0F69 ||
		c >= 0x10A0 && c <= 0x10C5 ||
		c >= 0x10D0 && c <= 0x10F6 ||
		c == 0x1100 ||
		c >= 0x1102 && c <= 0x1103 ||
		c >= 0x1105 && c <= 0x1107 ||
		c == 0x1109 ||
		c >= 0x110B && c <= 0x110C ||
		c >= 0x110E && c <= 0x1112 ||
		c == 0x113C ||
		c == 0x113E ||
		c == 0x1140 ||
		c == 0x114C ||
		c == 0x114E ||
		c == 0x1150 ||
		c >= 0x1154 && c <= 0x1155 ||
		c == 0x1159 ||
		c >= 0x115F && c <= 0x1161 ||
		c == 0x1163 ||
		c == 0x1165 ||
		c == 0x1167 ||
		c == 0x1169 ||
		c >= 0x116D && c <= 0x116E ||
		c >= 0x1172 && c <= 0x1173 ||
		c == 0x1175 ||
		c == 0x119E ||
		c == 0x11A8 ||
		c == 0x11AB ||
		c >= 0x11AE && c <= 0x11AF ||
		c >= 0x11B7 && c <= 0x11B8 ||
		c == 0x11BA ||
		c >= 0x11BC && c <= 0x11C2 ||
		c == 0x11EB ||
		c == 0x11F0 ||
		c == 0x11F9 ||
		c >= 0x1E00 && c <= 0x1E9B ||
		c >= 0x1EA0 && c <= 0x1EF9 ||
		c >= 0x1F00 && c <= 0x1F15 ||
		c >= 0x1F18 && c <= 0x1F1D ||
		c >= 0x1F20 && c <= 0x1F45 ||
		c >= 0x1F48 && c <= 0x1F4D ||
		c >= 0x1F50 && c <= 0x1F57 ||
		c == 0x1F59 ||
		c == 0x1F5B ||
		c == 0x1F5D ||
		c >= 0x1F5F && c <= 0x1F7D ||
		c >= 0x1F80 && c <= 0x1FB4 ||
		c >= 0x1FB6 && c <= 0x1FBC ||
		c == 0x1FBE ||
		c >= 0x1FC2 && c <= 0x1FC4 ||
		c >= 0x1FC6 && c <= 0x1FCC ||
		c >= 0x1FD0 && c <= 0x1FD3 ||
		c >= 0x1FD6 && c <= 0x1FDB ||
		c >= 0x1FE0 && c <= 0x1FEC ||
		c >= 0x1FF2 && c <= 0x1FF4 ||
		c >= 0x1FF6 && c <= 0x1FFC ||
		c == 0x2126 ||
		c >= 0x212A && c <= 0x212B ||
		c == 0x212E ||
		c >= 0x2180 && c <= 0x2182 ||
		c >= 0x3041 && c <= 0x3094 ||
		c >= 0x30A1 && c <= 0x30FA ||
		c >= 0x3105 && c <= 0x312C ||
		c >= 0xAC00 && c <= 0xD7A3 ||
		c >= 0x4E00 && c <= 0x9FA5 ||
		c == 0x3007 ||
		c >= 0x3021 && c <= 0x3029;
};

Utilities.isNCNameChar = function(c) {
	return c >= 0x0030 && c <= 0x0039
		|| c >= 0x0660 && c <= 0x0669
		|| c >= 0x06F0 && c <= 0x06F9
		|| c >= 0x0966 && c <= 0x096F
		|| c >= 0x09E6 && c <= 0x09EF
		|| c >= 0x0A66 && c <= 0x0A6F
		|| c >= 0x0AE6 && c <= 0x0AEF
		|| c >= 0x0B66 && c <= 0x0B6F
		|| c >= 0x0BE7 && c <= 0x0BEF
		|| c >= 0x0C66 && c <= 0x0C6F
		|| c >= 0x0CE6 && c <= 0x0CEF
		|| c >= 0x0D66 && c <= 0x0D6F
		|| c >= 0x0E50 && c <= 0x0E59
		|| c >= 0x0ED0 && c <= 0x0ED9
		|| c >= 0x0F20 && c <= 0x0F29
		|| c == 0x002E
		|| c == 0x002D
		|| c == 0x005F
		|| Utilities.isLetter(c)
		|| c >= 0x0300 && c <= 0x0345
		|| c >= 0x0360 && c <= 0x0361
		|| c >= 0x0483 && c <= 0x0486
		|| c >= 0x0591 && c <= 0x05A1
		|| c >= 0x05A3 && c <= 0x05B9
		|| c >= 0x05BB && c <= 0x05BD
		|| c == 0x05BF
		|| c >= 0x05C1 && c <= 0x05C2
		|| c == 0x05C4
		|| c >= 0x064B && c <= 0x0652
		|| c == 0x0670
		|| c >= 0x06D6 && c <= 0x06DC
		|| c >= 0x06DD && c <= 0x06DF
		|| c >= 0x06E0 && c <= 0x06E4
		|| c >= 0x06E7 && c <= 0x06E8
		|| c >= 0x06EA && c <= 0x06ED
		|| c >= 0x0901 && c <= 0x0903
		|| c == 0x093C
		|| c >= 0x093E && c <= 0x094C
		|| c == 0x094D
		|| c >= 0x0951 && c <= 0x0954
		|| c >= 0x0962 && c <= 0x0963
		|| c >= 0x0981 && c <= 0x0983
		|| c == 0x09BC
		|| c == 0x09BE
		|| c == 0x09BF
		|| c >= 0x09C0 && c <= 0x09C4
		|| c >= 0x09C7 && c <= 0x09C8
		|| c >= 0x09CB && c <= 0x09CD
		|| c == 0x09D7
		|| c >= 0x09E2 && c <= 0x09E3
		|| c == 0x0A02
		|| c == 0x0A3C
		|| c == 0x0A3E
		|| c == 0x0A3F
		|| c >= 0x0A40 && c <= 0x0A42
		|| c >= 0x0A47 && c <= 0x0A48
		|| c >= 0x0A4B && c <= 0x0A4D
		|| c >= 0x0A70 && c <= 0x0A71
		|| c >= 0x0A81 && c <= 0x0A83
		|| c == 0x0ABC
		|| c >= 0x0ABE && c <= 0x0AC5
		|| c >= 0x0AC7 && c <= 0x0AC9
		|| c >= 0x0ACB && c <= 0x0ACD
		|| c >= 0x0B01 && c <= 0x0B03
		|| c == 0x0B3C
		|| c >= 0x0B3E && c <= 0x0B43
		|| c >= 0x0B47 && c <= 0x0B48
		|| c >= 0x0B4B && c <= 0x0B4D
		|| c >= 0x0B56 && c <= 0x0B57
		|| c >= 0x0B82 && c <= 0x0B83
		|| c >= 0x0BBE && c <= 0x0BC2
		|| c >= 0x0BC6 && c <= 0x0BC8
		|| c >= 0x0BCA && c <= 0x0BCD
		|| c == 0x0BD7
		|| c >= 0x0C01 && c <= 0x0C03
		|| c >= 0x0C3E && c <= 0x0C44
		|| c >= 0x0C46 && c <= 0x0C48
		|| c >= 0x0C4A && c <= 0x0C4D
		|| c >= 0x0C55 && c <= 0x0C56
		|| c >= 0x0C82 && c <= 0x0C83
		|| c >= 0x0CBE && c <= 0x0CC4
		|| c >= 0x0CC6 && c <= 0x0CC8
		|| c >= 0x0CCA && c <= 0x0CCD
		|| c >= 0x0CD5 && c <= 0x0CD6
		|| c >= 0x0D02 && c <= 0x0D03
		|| c >= 0x0D3E && c <= 0x0D43
		|| c >= 0x0D46 && c <= 0x0D48
		|| c >= 0x0D4A && c <= 0x0D4D
		|| c == 0x0D57
		|| c == 0x0E31
		|| c >= 0x0E34 && c <= 0x0E3A
		|| c >= 0x0E47 && c <= 0x0E4E
		|| c == 0x0EB1
		|| c >= 0x0EB4 && c <= 0x0EB9
		|| c >= 0x0EBB && c <= 0x0EBC
		|| c >= 0x0EC8 && c <= 0x0ECD
		|| c >= 0x0F18 && c <= 0x0F19
		|| c == 0x0F35
		|| c == 0x0F37
		|| c == 0x0F39
		|| c == 0x0F3E
		|| c == 0x0F3F
		|| c >= 0x0F71 && c <= 0x0F84
		|| c >= 0x0F86 && c <= 0x0F8B
		|| c >= 0x0F90 && c <= 0x0F95
		|| c == 0x0F97
		|| c >= 0x0F99 && c <= 0x0FAD
		|| c >= 0x0FB1 && c <= 0x0FB7
		|| c == 0x0FB9
		|| c >= 0x20D0 && c <= 0x20DC
		|| c == 0x20E1
		|| c >= 0x302A && c <= 0x302F
		|| c == 0x3099
		|| c == 0x309A
		|| c == 0x00B7
		|| c == 0x02D0
		|| c == 0x02D1
		|| c == 0x0387
		|| c == 0x0640
		|| c == 0x0E46
		|| c == 0x0EC6
		|| c == 0x3005
		|| c >= 0x3031 && c <= 0x3035
		|| c >= 0x309D && c <= 0x309E
		|| c >= 0x30FC && c <= 0x30FE;
};

Utilities.coalesceText = function(n) {
	for (var m = n.firstChild; m != null; m = m.nextSibling) {
		if (m.nodeType == 3 /*Node.TEXT_NODE*/ || m.nodeType == 4 /*Node.CDATA_SECTION_NODE*/) {
			var s = m.nodeValue;
			var first = m;
			m = m.nextSibling;
			while (m != null && (m.nodeType == 3 /*Node.TEXT_NODE*/ || m.nodeType == 4 /*Node.CDATA_SECTION_NODE*/)) {
				s += m.nodeValue;
				var del = m;
				m = m.nextSibling;
				del.parentNode.removeChild(del);
			}
			if (first.nodeType == 4 /*Node.CDATA_SECTION_NODE*/) {
				var p = first.parentNode;
				if (first.nextSibling == null) {
					p.removeChild(first);
					p.appendChild(p.ownerDocument.createTextNode(s));
				} else {
					var next = first.nextSibling;
					p.removeChild(first);
					p.insertBefore(p.ownerDocument.createTextNode(s), next);
				}
			} else {
				first.nodeValue = s;
			}
			if (m == null) {
				break;
			}
		} else if (m.nodeType == 1 /*Node.ELEMENT_NODE*/) {
			Utilities.coalesceText(m);
		}
	}
};

Utilities.instance_of = function(o, c) {
	while (o != null) {
		if (o.constructor === c) {
			return true;
		}
		if (o === Object) {
			return false;
		}
		o = o.constructor.superclass;
	}
	return false;
};

Utilities.getElementById = function(n, id) {
	// Note that this does not check the DTD to check for actual
	// attributes of type ID, so this may be a bit wrong.
	if (n.nodeType == 1 /*Node.ELEMENT_NODE*/) {
		if (n.getAttribute("id") == id
				|| n.getAttributeNS(null, "id") == id) {
			return n;
		}
	}
	for (var m = n.firstChild; m != null; m = m.nextSibling) {
		var res = Utilities.getElementById(m, id);
		if (res != null) {
			return res;
		}
	}
	return null;
};

// XPathException ////////////////////////////////////////////////////////////

var XPathException = (function () {
    function getMessage(code, exception) {
        var msg = exception ? ": " + exception.toString() : "";
        switch (code) {
            case XPathException.INVALID_EXPRESSION_ERR:
                return "Invalid expression" + msg;
            case XPathException.TYPE_ERR:
                return "Type error" + msg;
        }
        return null;
    }

    function XPathException(code, error, message) {
        var err = Error.call(this, getMessage(code, error) || message);

        err.code = code;
        err.exception = error;

        return err;
    }

    XPathException.prototype = Object.create(Error.prototype);
    XPathException.prototype.constructor = XPathException;
    XPathException.superclass = Error;

    XPathException.prototype.toString = function() {
        return this.message;
    };

    XPathException.fromMessage = function(message, error) {
        return new XPathException(null, error, message);
    };

    XPathException.INVALID_EXPRESSION_ERR = 51;
    XPathException.TYPE_ERR = 52;

    return XPathException;
})();

// XPathExpression ///////////////////////////////////////////////////////////

XPathExpression.prototype = {};
XPathExpression.prototype.constructor = XPathExpression;
XPathExpression.superclass = Object.prototype;

function XPathExpression(e, r, p) {
	this.xpath = p.parse(e);
	this.context = new XPathContext();
	this.context.namespaceResolver = new XPathNSResolverWrapper(r);
}

XPathExpression.getOwnerDocument = function (n) {
	return n.nodeType === 9 /*Node.DOCUMENT_NODE*/ ? n : n.ownerDocument;
}

XPathExpression.detectHtmlDom = function (n) {
	if (!n) { return false; }
	
	var doc = XPathExpression.getOwnerDocument(n);
	
	try {
		return doc.implementation.hasFeature("HTML", "2.0");
	} catch (e) {
		return true;
	}
}

XPathExpression.prototype.evaluate = function(n, t, res) {
	this.context.expressionContextNode = n;
	// backward compatibility - no reliable way to detect whether the DOM is HTML, but
	// this library has been using this method up until now, so we will continue to use it
	// ONLY when using an XPathExpression
	this.context.caseInsensitive = XPathExpression.detectHtmlDom(n);
	
	var result = this.xpath.evaluate(this.context);
	return new XPathResult(result, t);
}

// XPathNSResolverWrapper ////////////////////////////////////////////////////

XPathNSResolverWrapper.prototype = {};
XPathNSResolverWrapper.prototype.constructor = XPathNSResolverWrapper;
XPathNSResolverWrapper.superclass = Object.prototype;

function XPathNSResolverWrapper(r) {
	this.xpathNSResolver = r;
}

XPathNSResolverWrapper.prototype.getNamespace = function(prefix, n) {
    if (this.xpathNSResolver == null) {
        return null;
    }
	return this.xpathNSResolver.lookupNamespaceURI(prefix);
};

// NodeXPathNSResolver ///////////////////////////////////////////////////////

NodeXPathNSResolver.prototype = {};
NodeXPathNSResolver.prototype.constructor = NodeXPathNSResolver;
NodeXPathNSResolver.superclass = Object.prototype;

function NodeXPathNSResolver(n) {
	this.node = n;
	this.namespaceResolver = new NamespaceResolver();
}

NodeXPathNSResolver.prototype.lookupNamespaceURI = function(prefix) {
	return this.namespaceResolver.getNamespace(prefix, this.node);
};

// XPathResult ///////////////////////////////////////////////////////////////

XPathResult.prototype = {};
XPathResult.prototype.constructor = XPathResult;
XPathResult.superclass = Object.prototype;

function XPathResult(v, t) {
	if (t == XPathResult.ANY_TYPE) {
		if (v.constructor === XString) {
			t = XPathResult.STRING_TYPE;
		} else if (v.constructor === XNumber) {
			t = XPathResult.NUMBER_TYPE;
		} else if (v.constructor === XBoolean) {
			t = XPathResult.BOOLEAN_TYPE;
		} else if (v.constructor === XNodeSet) {
			t = XPathResult.UNORDERED_NODE_ITERATOR_TYPE;
		}
	}
	this.resultType = t;
	switch (t) {
		case XPathResult.NUMBER_TYPE:
			this.numberValue = v.numberValue();
			return;
		case XPathResult.STRING_TYPE:
			this.stringValue = v.stringValue();
			return;
		case XPathResult.BOOLEAN_TYPE:
			this.booleanValue = v.booleanValue();
			return;
		case XPathResult.ANY_UNORDERED_NODE_TYPE:
		case XPathResult.FIRST_ORDERED_NODE_TYPE:
			if (v.constructor === XNodeSet) {
				this.singleNodeValue = v.first();
				return;
			}
			break;
		case XPathResult.UNORDERED_NODE_ITERATOR_TYPE:
		case XPathResult.ORDERED_NODE_ITERATOR_TYPE:
			if (v.constructor === XNodeSet) {
				this.invalidIteratorState = false;
				this.nodes = v.toArray();
				this.iteratorIndex = 0;
				return;
			}
			break;
		case XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE:
		case XPathResult.ORDERED_NODE_SNAPSHOT_TYPE:
			if (v.constructor === XNodeSet) {
				this.nodes = v.toArray();
				this.snapshotLength = this.nodes.length;
				return;
			}
			break;
	}
	throw new XPathException(XPathException.TYPE_ERR);
};

XPathResult.prototype.iterateNext = function() {
	if (this.resultType != XPathResult.UNORDERED_NODE_ITERATOR_TYPE
			&& this.resultType != XPathResult.ORDERED_NODE_ITERATOR_TYPE) {
		throw new XPathException(XPathException.TYPE_ERR);
	}
	return this.nodes[this.iteratorIndex++];
};

XPathResult.prototype.snapshotItem = function(i) {
	if (this.resultType != XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE
			&& this.resultType != XPathResult.ORDERED_NODE_SNAPSHOT_TYPE) {
		throw new XPathException(XPathException.TYPE_ERR);
	}
	return this.nodes[i];
};

XPathResult.ANY_TYPE = 0;
XPathResult.NUMBER_TYPE = 1;
XPathResult.STRING_TYPE = 2;
XPathResult.BOOLEAN_TYPE = 3;
XPathResult.UNORDERED_NODE_ITERATOR_TYPE = 4;
XPathResult.ORDERED_NODE_ITERATOR_TYPE = 5;
XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE = 6;
XPathResult.ORDERED_NODE_SNAPSHOT_TYPE = 7;
XPathResult.ANY_UNORDERED_NODE_TYPE = 8;
XPathResult.FIRST_ORDERED_NODE_TYPE = 9;

// DOM 3 XPath support ///////////////////////////////////////////////////////

function installDOM3XPathSupport(doc, p) {
	doc.createExpression = function(e, r) {
		try {
			return new XPathExpression(e, r, p);
		} catch (e) {
			throw new XPathException(XPathException.INVALID_EXPRESSION_ERR, e);
		}
	};
	doc.createNSResolver = function(n) {
		return new NodeXPathNSResolver(n);
	};
	doc.evaluate = function(e, cn, r, t, res) {
		if (t < 0 || t > 9) {
			throw { code: 0, toString: function() { return "Request type not supported"; } };
		}
        return doc.createExpression(e, r, p).evaluate(cn, t, res);
	};
};

// ---------------------------------------------------------------------------

// Install DOM 3 XPath support for the current document.
try {
	var shouldInstall = true;
	try {
		if (document.implementation
				&& document.implementation.hasFeature
				&& document.implementation.hasFeature("XPath", null)) {
			shouldInstall = false;
		}
	} catch (e) {
	}
	if (shouldInstall) {
		installDOM3XPathSupport(document, new XPathParser());
	}
} catch (e) {
}

// ---------------------------------------------------------------------------
// exports for node.js

installDOM3XPathSupport(exports, new XPathParser());

(function() {
    var parser = new XPathParser();

    var defaultNSResolver = new NamespaceResolver();
    var defaultFunctionResolver = new FunctionResolver();
    var defaultVariableResolver = new VariableResolver();

    function makeNSResolverFromFunction(func) {
        return {
            getNamespace: function (prefix, node) {
                var ns = func(prefix, node);

                return ns || defaultNSResolver.getNamespace(prefix, node);
            }
        };
    }

    function makeNSResolverFromObject(obj) {
        return makeNSResolverFromFunction(obj.getNamespace.bind(obj));
    }

    function makeNSResolverFromMap(map) {
        return makeNSResolverFromFunction(function (prefix) {
            return map[prefix];
        });
    }

    function makeNSResolver(resolver) {
        if (resolver && typeof resolver.getNamespace === "function") {
            return makeNSResolverFromObject(resolver);
        }

        if (typeof resolver === "function") {
            return makeNSResolverFromFunction(resolver);
        }

        // assume prefix -> uri mapping
        if (typeof resolver === "object") {
            return makeNSResolverFromMap(resolver);
        }

        return defaultNSResolver;
    }

    /** Converts native JavaScript types to their XPath library equivalent */
    function convertValue(value) {
        if (value === null ||
            typeof value === "undefined" ||
            value instanceof XString ||
            value instanceof XBoolean ||
            value instanceof XNumber ||
            value instanceof XNodeSet) {
            return value;
        }

        switch (typeof value) {
            case "string": return new XString(value);
            case "boolean": return new XBoolean(value);
            case "number": return new XNumber(value);
        }

        // assume node(s)
        var ns = new XNodeSet();
        ns.addArray([].concat(value));
        return ns;
    }

    function makeEvaluator(func) {
        return function (context) {
            var args = Array.prototype.slice.call(arguments, 1).map(function (arg) {
                return arg.evaluate(context);
            });
            var result = func.apply(this, [].concat(context, args));
            return convertValue(result);
        };
    }

    function makeFunctionResolverFromFunction(func) {
        return {
            getFunction: function (name, namespace) {
                var found = func(name, namespace);
                if (found) {
                    return makeEvaluator(found);
                }
                return defaultFunctionResolver.getFunction(name, namespace);
            }
        };
    }

    function makeFunctionResolverFromObject(obj) {
        return makeFunctionResolverFromFunction(obj.getFunction.bind(obj));
    }

    function makeFunctionResolverFromMap(map) {
        return makeFunctionResolverFromFunction(function (name) {
            return map[name];
        });
    }

    function makeFunctionResolver(resolver) {
        if (resolver && typeof resolver.getFunction === "function") {
            return makeFunctionResolverFromObject(resolver);
        }

        if (typeof resolver === "function") {
            return makeFunctionResolverFromFunction(resolver);
        }

        // assume map
        if (typeof resolver === "object") {
            return makeFunctionResolverFromMap(resolver);
        }

        return defaultFunctionResolver;
    }

    function makeVariableResolverFromFunction(func) {
        return {
            getVariable: function (name, namespace) {
                var value = func(name, namespace);
                return convertValue(value);
            }
        };
    }

    function makeVariableResolver(resolver) {
        if (resolver) {
            if (typeof resolver.getVariable === "function") {
                return makeVariableResolverFromFunction(resolver.getVariable.bind(resolver));
            }

            if (typeof resolver === "function") {
                return makeVariableResolverFromFunction(resolver);
            }

            // assume map
            if (typeof resolver === "object") {
                return makeVariableResolverFromFunction(function (name) {
                    return resolver[name];
                });
            }
        }

        return defaultVariableResolver;
    }
	
	function copyIfPresent(prop, dest, source) {
		if (prop in source) { dest[prop] = source[prop]; }
	}

    function makeContext(options) {
        var context = new XPathContext();

        if (options) {
            context.namespaceResolver = makeNSResolver(options.namespaces);
            context.functionResolver = makeFunctionResolver(options.functions);
            context.variableResolver = makeVariableResolver(options.variables);
			context.expressionContextNode = options.node;
			copyIfPresent('allowAnyNamespaceForNoPrefix', context, options);
			copyIfPresent('isHtml', context, options);
        } else {
            context.namespaceResolver = defaultNSResolver;
        }

        return context;
    }

    function evaluate(parsedExpression, options) {
        var context = makeContext(options);

        return parsedExpression.evaluate(context);
    }

    var evaluatorPrototype = {
        evaluate: function (options) {
            return evaluate(this.expression, options);
        }

        ,evaluateNumber: function (options) {
            return this.evaluate(options).numberValue();
        }

        ,evaluateString: function (options) {
            return this.evaluate(options).stringValue();
        }

        ,evaluateBoolean: function (options) {
            return this.evaluate(options).booleanValue();
        }

        ,evaluateNodeSet: function (options) {
            return this.evaluate(options).nodeset();
        }

        ,select: function (options) {
            return this.evaluateNodeSet(options).toArray()
        }

        ,select1: function (options) {
            return this.select(options)[0];
        }
    };

    function parse(xpath) {
        var parsed = parser.parse(xpath);

        return Object.create(evaluatorPrototype, {
            expression: {
                value: parsed
            }
        });
    }

    exports.parse = parse;
})();

exports.XPath = XPath;
exports.XPathParser = XPathParser;
exports.XPathResult = XPathResult;

exports.Step = Step;
exports.NodeTest = NodeTest;
exports.BarOperation = BarOperation;

exports.NamespaceResolver = NamespaceResolver;
exports.FunctionResolver = FunctionResolver;
exports.VariableResolver = VariableResolver;

exports.Utilities = Utilities;

exports.XPathContext = XPathContext;
exports.XNodeSet = XNodeSet;
exports.XBoolean = XBoolean;
exports.XString = XString;
exports.XNumber = XNumber;

// helper
exports.select = function(e, doc, single) {
	return exports.selectWithResolver(e, doc, null, single);
};

exports.useNamespaces = function(mappings) {
	var resolver = {
		mappings: mappings || {},
		lookupNamespaceURI: function(prefix) {
			return this.mappings[prefix];
		}
	};

	return function(e, doc, single) {
		return exports.selectWithResolver(e, doc, resolver, single);
	};
};

exports.selectWithResolver = function(e, doc, resolver, single) {
	var expression = new XPathExpression(e, resolver, new XPathParser());
	var type = XPathResult.ANY_TYPE;

	var result = expression.evaluate(doc, type, null);

	if (result.resultType == XPathResult.STRING_TYPE) {
		result = result.stringValue;
	}
	else if (result.resultType == XPathResult.NUMBER_TYPE) {
		result = result.numberValue;
	}
	else if (result.resultType == XPathResult.BOOLEAN_TYPE) {
		result = result.booleanValue;
	}
	else {
		result = result.nodes;
		if (single) {
			result = result[0];
		}
	}

	return result;
};

exports.select1 = function(e, doc) {
	return exports.select(e, doc, true);
};

// end non-node wrapper
})(xpath);
