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1866 lines (1835 loc) · 68.4 KB
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/** Here is yet another implementation of XPath 1.0 in Javascript.
*
* My goal was to make it relatively compact, but as I fixed all the axis bugs
* the axes became more and more complicated. :-(.
*
* I have not implemented namespaces or case-sensitive axes for XML yet.
*
* How to test it in Chrome: You can make a Chrome extension that replaces
* the WebKit XPath parser with this one. But it takes a bit of effort to
* get around isolated world and same-origin restrictions:
* manifest.json:
{
"name": "XPathTest",
"version": "0.1",
"content_scripts": [{
"matches": ["http://localhost/*"], // or wildcard host
"js": ["xpath.js", "injection.js"],
"all_frames": true, "run_at": "document_start"
}]
}
* injection.js:
// goal: give my xpath object to the website's JS context.
var script = document.createElement('script');
script.textContent =
"document.addEventListener('xpathextend', function(e) {\n" +
" console.log('extending document with xpath...');\n" +
" e.detail(window);" +
"});";
document.documentElement.appendChild(script);
document.documentElement.removeChild(script);
var evt = document.createEvent('CustomEvent');
evt.initCustomEvent('xpathextend', true, true, this.xpath.extend);
document.dispatchEvent(evt);
*/
(function() {
var xpath;
var core;
if ('function' === typeof require) {
xpath = exports; // the tests go through this
core = require("../level1/core");
} else {
xpath = {};
core = this;
}
/***************************************************************************
* Tokenization *
***************************************************************************/
/**
* The XPath lexer is basically a single regular expression, along with
* some helper functions to pop different types.
*/
var Stream = xpath.Stream = function Stream(str) {
this.original = this.str = str;
this.peeked = null;
// TODO: not really needed, but supposedly tokenizer also disambiguates
// a * b vs. node test *
this.prev = null; // for debugging
this.prevprev = null;
}
Stream.prototype = {
peek: function() {
if (this.peeked) return this.peeked;
var m = this.re.exec(this.str);
if (!m) return null;
this.str = this.str.substr(m[0].length);
return this.peeked = m[1];
},
/** Peek 2 tokens ahead. */
peek2: function() {
this.peek(); // make sure this.peeked is set
var m = this.re.exec(this.str);
if (!m) return null;
return m[1];
},
pop: function() {
var r = this.peek();
this.peeked = null;
this.prevprev = this.prev;
this.prev = r;
return r;
},
trypop: function(tokens) {
var tok = this.peek();
if (tok === tokens) return this.pop();
if (Array.isArray(tokens)) {
for (var i = 0; i < tokens.length; ++i) {
var t = tokens[i];
if (t == tok) return this.pop();;
}
}
},
trypopfuncname: function() {
var tok = this.peek();
if (!this.isQnameRe.test(tok))
return null;
switch (tok) {
case 'comment': case 'text': case 'processing-instruction': case 'node':
return null;
}
if ('(' != this.peek2()) return null;
return this.pop();
},
trypopaxisname: function() {
var tok = this.peek();
switch (tok) {
case 'ancestor': case 'ancestor-or-self': case 'attribute':
case 'child': case 'descendant': case 'descendant-or-self':
case 'following': case 'following-sibling': case 'namespace':
case 'parent': case 'preceding': case 'preceding-sibling': case 'self':
if ('::' == this.peek2()) return this.pop();
}
return null;
},
trypopnametest: function() {
var tok = this.peek();
if ('*' === tok || this.startsWithNcNameRe.test(tok)) return this.pop();
return null;
},
trypopliteral: function() {
var tok = this.peek();
if (null == tok) return null;
var first = tok.charAt(0);
var last = tok.charAt(tok.length - 1);
if ('"' === first && '"' === last ||
"'" === first && "'" === last) {
this.pop();
return tok.substr(1, tok.length - 2);
}
},
trypopnumber: function() {
var tok = this.peek();
if (this.isNumberRe.test(tok)) return parseFloat(this.pop());
else return null;
},
trypopvarref: function() {
var tok = this.peek();
if (null == tok) return null;
if ('$' === tok.charAt(0)) return this.pop().substr(1);
else return null;
},
position: function() {
return this.original.length - this.str.length;
}
};
(function() {
// http://www.w3.org/TR/REC-xml-names/#NT-NCName
var nameStartCharsExceptColon =
'A-Z_a-z\xc0-\xd6\xd8-\xf6\xF8-\u02FF\u0370-\u037D\u037F-\u1FFF' +
'\u200C-\u200D\u2070-\u218F\u2C00-\u2FEF\u3001-\uD7FF\uF900-\uFDCF' +
'\uFDF0-\uFFFD'; // JS doesn't support [#x10000-#xEFFFF]
var nameCharExceptColon = nameStartCharsExceptColon +
'\\-\\.0-9\xb7\u0300-\u036F\u203F-\u2040';
var ncNameChars = '[' + nameStartCharsExceptColon +
'][' + nameCharExceptColon + ']*'
// http://www.w3.org/TR/REC-xml-names/#NT-QName
var qNameChars = ncNameChars + '(?::' + ncNameChars + ')?';
var otherChars = '\\.\\.|[\\(\\)\\[\\].@,]|::'; // .. must come before [.]
var operatorChars =
'and|or|mod|div|' +
'//|!=|<=|>=|[*/|+\\-=<>]'; // //, !=, <=, >= before individual ones.
var literal = '"[^"]*"|' + "'[^']*'";
var numberChars = '[0-9]+(?:\\.[0-9]*)?|\\.[0-9]+';
var variableReference = '\\$' + qNameChars;
var nameTestChars = '\\*|' + ncNameChars + ':\\*|' + qNameChars;
var optionalSpace = '[ \t\r\n]*'; // stricter than regexp \s.
var nodeType = 'comment|text|processing-instruction|node';
var re = new RegExp(
// numberChars before otherChars so that leading-decimal doesn't become .
'^' + optionalSpace + '(' + numberChars + '|' + otherChars + '|' +
nameTestChars + '|' + operatorChars + '|' + literal + '|' +
variableReference + ')'
// operatorName | nodeType | functionName | axisName are lumped into
// qName for now; we'll check them on pop.
);
Stream.prototype.re = re;
Stream.prototype.startsWithNcNameRe = new RegExp('^' + ncNameChars);
Stream.prototype.isQnameRe = new RegExp('^' + qNameChars + '$');
Stream.prototype.isNumberRe = new RegExp('^' + numberChars + '$');
})();
/***************************************************************************
* Parsing *
***************************************************************************/
var parse = xpath.parse = function parse(stream, a) {
var r = orExpr(stream,a);
var x, unparsed = [];
while (x = stream.pop()) {
unparsed.push(x);
}
if (unparsed.length)
throw new XPathException(XPathException.INVALID_EXPRESSION_ERR,
'Position ' + stream.position() +
': Unparsed tokens: ' + unparsed.join(' '));
return r;
}
/**
* binaryL ::= subExpr
* | binaryL op subExpr
* so a op b op c becomes ((a op b) op c)
*/
function binaryL(subExpr, stream, a, ops) {
var lhs = subExpr(stream, a);
if (lhs == null) return null;
var op;
while (op = stream.trypop(ops)) {
var rhs = subExpr(stream, a);
if (rhs == null)
throw new XPathException(XPathException.INVALID_EXPRESSION_ERR,
'Position ' + stream.position() +
8
10BC8
': Expected something after ' + op);
lhs = a.node(op, lhs, rhs);
}
return lhs;
}
/**
* Too bad this is never used. If they made a ** operator (raise to power),
( we would use it.
* binaryR ::= subExpr
* | subExpr op binaryR
* so a op b op c becomes (a op (b op c))
*/
function binaryR(subExpr, stream, a, ops) {
var lhs = subExpr(stream, a);
if (lhs == null) return null;
var op = stream.trypop(ops);
if (op) {
var rhs = binaryR(stream, a);
if (rhs == null)
throw new XPathException(XPathException.INVALID_EXPRESSION_ERR,
'Position ' + stream.position() +
': Expected something after ' + op);
return a.node(op, lhs, rhs);
} else {
return lhs;// TODO
}
}
/** [1] LocationPath::= RelativeLocationPath | AbsoluteLocationPath
* e.g. a, a/b, //a/b
*/
function locationPath(stream, a) {
return absoluteLocationPath(stream, a) ||
relativeLocationPath(null, stream, a);
}
/** [2] AbsoluteLocationPath::= '/' RelativeLocationPath? | AbbreviatedAbsoluteLocationPath
* [10] AbbreviatedAbsoluteLocationPath::= '//' RelativeLocationPath
*/
function absoluteLocationPath(stream, a) {
var op = stream.peek();
if ('/' === op || '//' === op) {
var lhs = a.node('Root');
return relativeLocationPath(lhs, stream, a, true);
} else {
return null;
}
}
/** [3] RelativeLocationPath::= Step | RelativeLocationPath '/' Step |
* | AbbreviatedRelativeLocationPath
* [11] AbbreviatedRelativeLocationPath::= RelativeLocationPath '//' Step
* e.g. p/a, etc.
*/
function relativeLocationPath(lhs, stream, a, isOnlyRootOk) {
if (null == lhs) {
lhs = step(stream, a);
if (null == lhs) return lhs;
}
var op;
while (op = stream.trypop(['/', '//'])) {
if ('//' === op) {
lhs = a.node('/', lhs,
a.node('Axis', 'descendant-or-self', 'node', undefined));
}
var rhs = step(stream, a);
if (null == rhs && '/' === op && isOnlyRootOk) return lhs;
else isOnlyRootOk = false;
if (null == rhs)
throw new XPathException(XPathException.INVALID_EXPRESSION_ERR,
'Position ' + stream.position() +
': Expected step after ' + op);
lhs = a.node('/', lhs, rhs);
}
return lhs;
}
/** [4] Step::= AxisSpecifier NodeTest Predicate* | AbbreviatedStep
* [12] AbbreviatedStep::= '.' | '..'
* e.g. @href, self::p, p, a[@href], ., ..
*/
function step(stream, a) {
var abbrStep = stream.trypop(['.', '..']);
if ('.' === abbrStep) // A location step of . is short for self::node().
return a.node('Axis', 'self', 'node');
if ('..' === abbrStep) // A location step of .. is short for parent::node()
return a.node('Axis', 'parent', 'node');
var axis = axisSpecifier(stream, a);
var nodeType = nodeTypeTest(stream, a);
var nodeName;
if (null == nodeType) nodeName = nodeNameTest(stream, a);
if (null == axis && null == nodeType && null == nodeName) return null;
if (null == nodeType && null == nodeName)
throw new XPathException(
XPathException.INVALID_EXPRESSION_ERR,
'Position ' + stream.position() +
': Expected nodeTest after axisSpecifier ' + axis);
if (null == axis) axis = 'child';
if (null == nodeType) {
// When there's only a node name, then the node type is forced to be the
// principal node type of the axis.
// see http://www.w3.org/TR/xpath/#dt-principal-node-type
if ('attribute' === axis) nodeType = 'attribute';
else if ('namespace' === axis) nodeType = 'namespace';
else nodeType = 'element';
}
var lhs = a.node('Axis', axis, nodeType, nodeName);
var pred;
while (null != (pred = predicate(lhs, stream, a))) {
lhs = pred;
}
return lhs;
}
/** [5] AxisSpecifier::= AxisName '::' | AbbreviatedAxisSpecifier
* [6] AxisName::= 'ancestor' | 'ancestor-or-self' | 'attribute' | 'child'
* | 'descendant' | 'descendant-or-self' | 'following'
* | 'following-sibling' | 'namespace' | 'parent' |
* | 'preceding' | 'preceding-sibling' | 'self'
* [13] AbbreviatedAxisSpecifier::= '@'?
*/
function axisSpecifier(stream, a) {
var attr = stream.trypop('@');
if (null != attr) return 'attribute';
var axisName = stream.trypopaxisname();
if (null != axisName) {
var coloncolon = stream.trypop('::');
if (null == coloncolon)
throw new XPathException(XPathException.INVALID_EXPRESSION_ERR,
'Position ' + stream.position() +
': Should not happen. Should be ::.');
return axisName;
}
}
/** [7] NodeTest::= NameTest | NodeType '(' ')' | 'processing-instruction' '(' Literal ')'
* [38] NodeType::= 'comment' | 'text' | 'processing-instruction' | 'node'
* I've split nodeTypeTest from nodeNameTest for convenience.
*/
function nodeTypeTest(stream, a) {
if ('(' !== stream.peek2()) {
return null;
}
var type = stream.trypop(['comment', 'text', 'processing-instruction', 'node']);
if (null != type) {
if (null == stream.trypop('('))
throw new XPathException(XPathException.INVALID_EXPRESSION_ERR,
'Position ' + stream.position() +
': Should not happen.');
var param = undefined;
if (type == 'processing-instruction') {
param = stream.trypopliteral();
}
if (null == stream.trypop(')'))
throw new XPathException(XPathException.INVALID_EXPRESSION_ERR,
'Position ' + stream.position() +
': Expected close parens.');
return type
}
}
function nodeNameTest(stream, a) {
var name = stream.trypopnametest();
if (name != null) return name;
else return null;
}
/** [8] Predicate::= '[' PredicateExpr ']'
* [9] PredicateExpr::= Expr
*/
function predicate(lhs, stream, a) {
if (null == stream.trypop('[')) return null;
var expr = orExpr(stream, a);
if (null == expr)
throw new XPathException(XPathException.INVALID_EXPRESSION_ERR,
'Position ' + stream.position() +
': Expected expression after [');
if (null == stream.trypop(']'))
throw new XPathException(XPathException.INVALID_EXPRESSION_ERR,
'Position ' + stream.position() +
': Expected ] after expression.');
return a.node('Predicate', lhs, expr);
}
/** [14] Expr::= OrExpr
*/
/** [15] PrimaryExpr::= VariableReference | '(' Expr ')' | Literal | Number | FunctionCall
* e.g. $x, (3+4), "hi", 32, f(x)
*/
function primaryExpr(stream, a) {
var x = stream.trypopliteral();
if (null == x)
x = stream.trypopnumber();
if (null != x) {
return x;
}
var varRef = stream.trypopvarref();
if (null != varRef) return a.node('VariableReference', varRef);
var funCall = functionCall(stream, a);
if (null != funCall) {
return funCall;
}
if (stream.trypop('(')) {
var e = orExpr(stream, a);
if (null == e)
throw new XPathException(XPathException.INVALID_EXPRESSION_ERR,
'Position ' + stream.position() +
': Expected expression after (.');
if (null == stream.trypop(')'))
throw new XPathException(XPathException.INVALID_EXPRESSION_ERR,
'Position ' + stream.position() +
': Expected ) after expression.');
return e;
}
return null;
}
/** [16] FunctionCall::= FunctionName '(' ( Argument ( ',' Argument )* )? ')'
* [17] Argument::= Expr
*/
function functionCall(stream, a) {
var name = stream.trypopfuncname(stream, a);
if (null == name) return null;
if (null == stream.trypop('('))
throw new XPathException(XPathException.INVALID_EXPRESSION_ERR,
'Position ' + stream.position() +
': Expected ( ) after function name.');
var params = [];
var first = true;
while (null == stream.trypop(')')) {
if (!first && null == stream.trypop(','))
throw new XPathException(XPathException.INVALID_EXPRESSION_ERR,
'Position ' + stream.position() +
': Expected , between arguments of the function.');
first = false;
var param = orExpr(stream, a);
if (param == null)
throw new XPathException(XPathException.INVALID_EXPRESSION_ERR,
'Position ' + stream.position() +
': Expected expression as argument of function.');
params.push(param);
}
return a.node('FunctionCall', name, params);
}
/** [18] UnionExpr::= PathExpr | UnionExpr '|' PathExpr
*/
function unionExpr(stream, a) { return binaryL(pathExpr, stream, a, '|'); }
/** [19] PathExpr ::= LocationPath
* | FilterExpr
* | FilterExpr '/' RelativeLocationPath
* | FilterExpr '//' RelativeLocationPath
* Unlike most other nodes, this one always generates a node because
* at this point all reverse nodesets must turn into a forward nodeset
*/
function pathExpr(stream, a) {
// We have to do FilterExpr before LocationPath because otherwise
// LocationPath will eat up the name from a function call.
var filter = filterExpr(stream, a);
if (null == filter) {
var loc = locationPath(stream, a);
if (null == loc) {
throw new Error
throw new XPathException(XPathException.INVALID_EXPRESSION_ERR,
'Position ' + stream.position() +
': The expression shouldn\'t be empty...');
}
return a.node('PathExpr', loc);
}
var rel = relativeLocationPath(filter, stream, a, false);
if (filter === rel) return rel;
else return a.node('PathExpr', rel);
}
/** [20] FilterExpr::= PrimaryExpr | FilterExpr Predicate
* aka. FilterExpr ::= PrimaryExpr Predicate*
*/
function filterExpr(stream, a) {
var primary = primaryExpr(stream, a);
if (primary == null) return null;
var pred, lhs = primary;
while (null != (pred = predicate(lhs, stream, a))) {
lhs = pred;
}
return lhs;
}
/** [21] OrExpr::= AndExpr | OrExpr 'or' AndExpr
*/
function orExpr(stream, a) {
var orig = (stream.peeked || '') + stream.str
var r = binaryL(andExpr, stream, a, 'or');
var now = (stream.peeked || '') + stream.str;
return r;
}
/** [22] AndExpr::= EqualityExpr | AndExpr 'and' EqualityExpr
*/
function andExpr(stream, a) { return binaryL(equalityExpr, stream, a, 'and'); }
/** [23] EqualityExpr::= RelationalExpr | EqualityExpr '=' RelationalExpr
* | EqualityExpr '!=' RelationalExpr
*/
function equalityExpr(stream, a) { return binaryL(relationalExpr, stream, a, ['=','!=']); }
/** [24] RelationalExpr::= AdditiveExpr | RelationalExpr '<' AdditiveExpr
* | RelationalExpr '>' AdditiveExpr
* | RelationalExpr '<=' AdditiveExpr
* | RelationalExpr '>=' AdditiveExpr
*/
function relationalExpr(stream, a) { return binaryL(additiveExpr, stream, a, ['<','>','<=','>=']); }
/** [25] AdditiveExpr::= MultiplicativeExpr
* | AdditiveExpr '+' MultiplicativeExpr
* | AdditiveExpr '-' MultiplicativeExpr
*/
function additiveExpr(stream, a) { return binaryL(multiplicativeExpr, stream, a, ['+','-']); }
/** [26] MultiplicativeExpr::= UnaryExpr
* | MultiplicativeExpr MultiplyOperator UnaryExpr
* | MultiplicativeExpr 'div' UnaryExpr
* | MultiplicativeExpr 'mod' UnaryExpr
*/
function multiplicativeExpr(stream, a) { return binaryL(unaryExpr, stream, a, ['*','div','mod']); }
/** [27] UnaryExpr::= UnionExpr | '-' UnaryExpr
*/
function unaryExpr(stream, a) {
if (stream.trypop('-')) {
var e = unaryExpr(stream, a);
if (null == e)
throw new XPathException(XPathException.INVALID_EXPRESSION_ERR,
'Position ' + stream.position() +
': Expected unary expression after -');
return a.node('UnaryMinus', e);
}
else return unionExpr(stream, a);
}
var astFactory = {
node: function() {return Array.prototype.slice.call(arguments);}
};
/***************************************************************************
* Optimizations (TODO) *
***************************************************************************/
/**
* Some things I've been considering:
* 1) a//b becomes a/descendant::b if there's no predicate that uses
* position() or last()
* 2) axis[pred]: when pred doesn't use position, evaluate it just once per
* node in the node-set rather than once per (node, position, last).
* For more optimizations, look up Gecko's optimizer:
* http://mxr.mozilla.org/mozilla-central/source/content/xslt/src/xpath/txXPathOptimizer.cpp
*/
// TODO
function optimize(ast) {
}
/***************************************************************************
* Evaluation: axes *
***************************************************************************/
/**
* Data types: For string, number, boolean, we just use Javascript types.
* Node-sets have the form
* {nodes: [node, ...]}
* or {nodes: [node, ...], pos: [[1], [2], ...], lasts: [[1], [2], ...]}
*
* Most of the time, only the node is used and the position information is
* discarded. But if you use a predicate, we need to try every value of
* position and last in case the predicate calls position() or last().
*/
/**
* The NodeMultiSet is a helper class to help generate
* {nodes:[], pos:[], lasts:[]} structures. It is useful for the
* descendant, descendant-or-self, following-sibling, and
* preceding-sibling axes for which we can use a stack to organize things.
*/
function NodeMultiSet(isReverseAxis) {
this.nodes = [];
this.pos = [];
this.lasts = [];
this.nextPos = [];
this.seriesIndexes = []; // index within nodes that each series begins.
this.isReverseAxis = isReverseAxis;
this._pushToNodes = isReverseAxis ? Array.prototype.unshift : Array.prototype.push;
}
NodeMultiSet.prototype = {
pushSeries: function pushSeries() {
this.nextPos.push(1);
this.seriesIndexes.push(this.nodes.length);
},
popSeries: function popSeries() {
console.assert(0 < this.nextPos.length, this.nextPos);
var last = this.nextPos.pop() - 1,
indexInPos = this.nextPos.length,
seriesBeginIndex = this.seriesIndexes.pop(),
seriesEndIndex = this.nodes.length;
for (var i = seriesBeginIndex; i < seriesEndIndex; ++i) {
console.assert(indexInPos < this.lasts[i].length);
console.assert(undefined === this.lasts[i][indexInPos]);
this.lasts[i][indexInPos] = last;
}
},
finalize: function() {
if (null == this.nextPos) return this;
console.assert(0 === this.nextPos.length);
for (var i = 0; i < this.lasts.length; ++i) {
for (var j = 0; j < this.lasts[i].length; ++j) {
console.assert(null != this.lasts[i][j], i + ',' + j + ':' + JSON.stringify(this.lasts));
}
}
this.pushSeries = this.popSeries = this.addNode = function() {
throw new Error('Already finalized.');
};
return this;
},
addNode: function addNode(node) {
console.assert(node);
this._pushToNodes.call(this.nodes, node)
this._pushToNodes.call(this.pos, this.nextPos.slice());
this._pushToNodes.call(this.lasts, new Array(this.nextPos.length));
for (var i = 0; i < this.nextPos.length; ++i) this.nextPos[i]++;
},
simplify: function() {
this.finalize();
return {nodes:this.nodes, pos:this.pos, lasts:this.lasts};
}
};
function eachContext(nodeMultiSet) {
var r = [];
for (var i = 0; i < nodeMultiSet.nodes.length; i++) {
var node = nodeMultiSet.nodes[i];
if (!nodeMultiSet.pos) {
r.push({nodes:[node], pos: [[i + 1]], lasts: [[nodeMultiSet.nodes.length]]});
} else {
for (var j = 0; j < nodeMultiSet.pos[i].length; ++j) {
r.push({nodes:[node], pos: [[nodeMultiSet.pos[i][j]]], lasts: [[nodeMultiSet.lasts[i][j]]]});
}
}
}
return r;
}
/** Matcher used in the axes.
*/
function NodeMatcher(nodeTypeNum, nodeName, shouldLowerCase) {
this.nodeTypeNum = nodeTypeNum;
this.nodeName = nodeName;
this.shouldLowerCase = shouldLowerCase;
this.nodeNameTest =
null == nodeName ? this._alwaysTrue :
shouldLowerCase ? this._nodeNameLowerCaseEquals :
this._nodeNameEquals;
}
NodeMatcher.prototype = {
matches: function matches(node) {
return (0 === this.nodeTypeNum || node.nodeType === this.nodeTypeNum) &&
this.nodeNameTest(node.nodeName);
},
_alwaysTrue: function(name) {return true;},
_nodeNameEquals: function _nodeNameEquals(name) {
return this.nodeName === name;
},
_nodeNameLowerCaseEquals: function _nodeNameLowerCaseEquals(name) {
return this.nodeName === name.toLowerCase();
}
};
function followingSiblingHelper(nodeList /*destructive!*/, nodeTypeNum, nodeName, shouldLowerCase, shift, peek, followingNode, andSelf, isReverseAxis) {
var matcher = new NodeMatcher(nodeTypeNum, nodeName, shouldLowerCase);
var nodeMultiSet = new NodeMultiSet(isReverseAxis);
while (0 < nodeList.length) { // can be if for following, preceding
var node = shift.call(nodeList);
console.assert(node != null);
node = followingNode(node);
nodeMultiSet.pushSeries();
var numPushed = 1;
while (null != node) {
if (! andSelf && matcher.matches(node))
nodeMultiSet.addNode(node);
if (node === peek.call(nodeList)) {
shift.call(nodeList);
nodeMultiSet.pushSeries();
numPushed++;
}
if (andSelf && matcher.matches(node))
nodeMultiSet.addNode(node);
node = followingNode(node);
}
while (0 < numPushed--)
nodeMultiSet.popSeries();
}
return nodeMultiSet;
}
/** Returns the next non-descendant node in document order.
* This is the first node in following::node(), if node is the context.
*/
function followingNonDescendantNode(node) {
if (node.ownerElement) {
if (node.ownerElement.firstChild)
return node.ownerElement.firstChild;
node = node.ownerElement;
}
do {
if (node.nextSibling) return node.nextSibling;
} while (node = node.parentNode);
return null;
}
/** Returns the next node in a document-order depth-first search.
* See the definition of document order[1]:
* 1) element
* 2) namespace nodes
* 3) attributes
* 4) children
* [1]: http://www.w3.org/TR/xpath/#dt-document-order
*/
function followingNode(node) {
if (node.ownerElement) // attributes: following node of element.
node = node.ownerElement;
if (null != node.firstChild)
return node.firstChild;
do {
if (null != node.nextSibling) {
return node.nextSibling;
}
node = node.parentNode;
} while (node);
return null;
}
/** Returns the previous node in document order (excluding attributes
* and namespace nodes).
*/
function precedingNode(node) {
if (node.ownerElement)
return node.ownerElement;
if (null != node.previousSibling) {
node = node.previousSibling;
while (null != node.lastChild) {
node = node.lastChild;
}
return node;
}
if (null != node.parentNode) {
return node.parentNode;
}
return null;
}
/** This axis is inefficient if there are many nodes in the nodeList.
* But I think it's a pretty useless axis so it's ok. */
function followingHelper(nodeList /*destructive!*/, nodeTypeNum, nodeName, shouldLowerCase) {
var matcher = new NodeMatcher(nodeTypeNum, nodeName, shouldLowerCase);
var nodeMultiSet = new NodeMultiSet(false);
var cursor = nodeList[0];
var unorderedFollowingStarts = [];
for (var i = 0; i < nodeList.length; i++) {
var node = nodeList[i];
var start = followingNonDescendantNode(node);
if (start)
unorderedFollowingStarts.push(start);
}
if (0 === unorderedFollowingStarts.length)
return {nodes:[]};
var pos = [], nextPos = [];
var started = 0;
while (cursor = followingNode(cursor)) {
for (var i = unorderedFollowingStarts.length - 1; i >= 0; i--){
if (cursor === unorderedFollowingStarts[i]) {
nodeMultiSet.pushSeries();
unorderedFollowingStarts.splice(i,i+1);
started++;
}
}
if (started && matcher.matches(cursor)) {
nodeMultiSet.addNode(cursor);
}
}
console.assert(0 === unorderedFollowingStarts.length);
for (var i = 0; i < started; i++)
nodeMultiSet.popSeries();
return nodeMultiSet.finalize();
}
function precedingHelper(nodeList /*destructive!*/, nodeTypeNum, nodeName, shouldLowerCase) {
var matcher = new NodeMatcher(nodeTypeNum, nodeName, shouldLowerCase);
var cursor = nodeList.pop();
if (null == cursor) return {nodes:{}};
var r = {nodes:[], pos:[], lasts:[]};
var nextParents = [cursor.parentNode || cursor.ownerElement], nextPos = [1];
while (cursor = precedingNode(cursor)) {
if (cursor === nodeList[nodeList.length - 1]) {
nextParents.push(nodeList.pop());
nextPos.push(1);
}
var matches = matcher.matches(cursor);
var pos, someoneUsed = false;
if (matches)
pos = nextPos.slice();
for (var i = 0; i < nextParents.length; ++i) {
if (cursor === nextParents[i]) {
nextParents[i] = cursor.parentNode || cursor.ownerElement;
if (matches) {
pos[i] = null;
}
} else {
if (matches) {
pos[i] = nextPos[i]++;
someoneUsed = true;
}
}
}
if (someoneUsed) {
r.nodes.unshift(cursor);
r.pos.unshift(pos);
}
}
for (var i = 0; i < r.pos.length; ++i) {
var lasts = [];
r.lasts.push(lasts);
for (var j = r.pos[i].length - 1; j >= 0; j--) {
if (null == r.pos[i][j]) {
r.pos[i].splice(j, j+1);
} else {
lasts.unshift(nextPos[j] - 1);
}
}
}
return r;
}
/** node-set, axis -> node-set */
function descendantDfs(nodeMultiSet, node, remaining, matcher, andSelf, attrIndices, attrNodes) {
while (0 < remaining.length && null != remaining[0].ownerElement) {
var attr = remaining.shift();
if (andSelf && matcher.matches(attr)) {
attrNodes.push(attr);
attrIndices.push(nodeMultiSet.nodes.length);
}
}
if (null != node && !andSelf) {
if (matcher.matches(node))
nodeMultiSet.addNode(node);
}
var pushed = false;
if (null == node) {
if (0 === remaining.length) return;
node = remaining.shift();
nodeMultiSet.pushSeries();
pushed = true;
} else if (0 < remaining.length && node === remaining[0]) {
nodeMultiSet.pushSeries();
pushed = true;
remaining.shift();
}
if (andSelf) {
if (matcher.matches(node))
nodeMultiSet.addNode(node);
}
// TODO: use optimization. Also try element.getElementsByTagName
// var nodeList = 1 === nodeTypeNum && null != node.children ? node.children : node.childNodes;
var nodeList = node.childNodes;
for (var j = 0; j < nodeList.length; ++j) {
var child = nodeList[j];
descendantDfs(nodeMultiSet, child, remaining, matcher, andSelf, attrIndices, attrNodes);
}
if (pushed) {
nodeMultiSet.popSeries();
}
}
function descenantHelper(nodeList /*destructive!*/, nodeTypeNum, nodeName, shouldLowerCase, andSelf) {
var matcher = new NodeMatcher(nodeTypeNum, nodeName, shouldLowerCase);
var nodeMultiSet = new NodeMultiSet(false);
var attrIndices = [], attrNodes = [];
while (0 < nodeList.length) {
// var node = nodeList.shift();
descendantDfs(nodeMultiSet, null, nodeList, matcher, andSelf, attrIndices, attrNodes);
}
nodeMultiSet.finalize();
for (var i = attrNodes.length-1; i >= 0; --i) {
nodeMultiSet.nodes.splice(attrIndices[i], attrIndices[i], attrNodes[i]);
nodeMultiSet.pos.splice(attrIndices[i], attrIndices[i], [1]);
nodeMultiSet.lasts.splice(attrIndices[i], attrIndices[i], [1]);
}
return nodeMultiSet;
}
/**
*/
function ancestorHelper(nodeList /*destructive!*/, nodeTypeNum, nodeName, shouldLowerCase, andSelf) {
var matcher = new NodeMatcher(nodeTypeNum, nodeName, shouldLowerCase);
var ancestors = []; // array of non-empty arrays of matching ancestors
for (var i = 0; i < nodeList.length; ++i) {
var node = nodeList[i];
var isFirst = true;
var a = [];
while (null != node) {
if (!isFirst || andSelf) {
if (matcher.matches(node))
a.push(node);
}
isFirst = false;
node = node.parentNode || node.ownerElement;
}
if (0 < a.length)
ancestors.push(a);
}
var lasts = [];
for (var i = 0; i < ancestors.length; ++i) lasts.push(ancestors[i].length);
var nodeMultiSet = new NodeMultiSet(true);
var newCtx = {nodes:[], pos:[], lasts:[]};
while (0 < ancestors.length) {
var pos = [ancestors[0].length];
var last = [lasts[0]];
var node = ancestors[0].pop();
for (var i = ancestors.length - 1; i > 0; --i) {
if (node === ancestors[i][ancestors[i].length - 1]) {
pos.push(ancestors[i].length);
last.push(lasts[i]);
ancestors[i].pop();
if (0 === ancestors[i].length) {
ancestors.splice(i, i+1);
lasts.splice(i, i+1);
}
}
}
if (0 === ancestors[0].length) {
ancestors.shift();
lasts.shift();
}
newCtx.nodes.push(node);
newCtx.pos.push(pos);
newCtx.lasts.push(last);
}
return newCtx;
}
/** Helper function for sortDocumentOrder. Returns a list of indices, from the
* node to the root, of positions within parent.
* For convenience, the node is the first element of the array.
*/
function addressVector(node) {
var r = [node];
if (null != node.ownerElement) {
node = node.ownerElement;
r.push(-1);
}
while (null != node) {
var i = 0;
while (null != node.previousSibling) {
node = node.previousSibling;
i++;
}
r.push(i);
node = node.parentNode
}
return r;
}
function addressComparator(a, b) {
var minlen = Math.min(a.length - 1, b.length - 1), // not including [0]=node
alen = a.length,
blen = b.length;
if (a[0] === b[0]) return 0;
var c;
for (var i = 0; i < minlen; ++i) {
c = a[alen - i - 1] - b[blen - i - 1];
if (0 !== c)
break;
}
if (null == c || 0 === c) {
// All equal until one of the nodes. The longer one is the descendant.
c = alen - blen;
}
if (0 === c)
c = a.nodeName - b.nodeName;
if (0 === c)
c = 1;
return c;
}
var sortUniqDocumentOrder = xpath.sortUniqDocumentOrder = function(nodes) {
var a = [];
for (var i = 0; i < nodes.length; i++) {
var node = nodes[i];
var v = addressVector(node);
a.push(v);
}
a.sort(addressComparator);
var b = [];
for (var i = 0; i < a.length; i++) {
if (0 < i && a[i][0] === a[i - 1][0])
continue;
b.push(a[i][0]);
}
return b;
}
/** Sort node multiset. Does not do any de-duping. */
function sortNodeMultiSet(nodeMultiSet) {
var a = [];
for (var i = 0; i < nodeMultiSet.nodes.length; i++) {
var v = addressVector(nodeMultiSet.nodes[i]);
a.push({v:v, n:nodeMultiSet.nodes[i],
p:nodeMultiSet.pos[i], l:nodeMultiSet.lasts[i]});
}
a.sort(compare);