Src/scripts/xpath.js
// xpath.js - version 0.7 - Spry Pre-Release 1.6.1
//
// Code from xmltoken.js.
//
// Copyright 2006 Google Inc.
// All Rights Reserved
//
// Defines regular expression patterns to extract XML tokens from string.
// See <http://www.w3.org/TR/REC-xml/#sec-common-syn>,
// <http://www.w3.org/TR/xml11/#sec-common-syn> and
// <http://www.w3.org/TR/REC-xml-names/#NT-NCName> for the specifications.
//
// Author: Junji Takagi <jtakagi@google.com>
// Detect whether RegExp supports Unicode characters or not.
var REGEXP_UNICODE = function() {
var tests = [' ', '\u0120', -1, // Konquerer 3.4.0 fails here.
'!', '\u0120', -1,
'\u0120', '\u0120', 0,
'\u0121', '\u0120', -1,
'\u0121', '\u0120|\u0121', 0,
'\u0122', '\u0120|\u0121', -1,
'\u0120', '[\u0120]', 0, // Safari 2.0.3 fails here.
'\u0121', '[\u0120]', -1,
'\u0121', '[\u0120\u0121]', 0, // Safari 2.0.3 fails here.
'\u0122', '[\u0120\u0121]', -1,
'\u0121', '[\u0120-\u0121]', 0, // Safari 2.0.3 fails here.
'\u0122', '[\u0120-\u0121]', -1];
for (var i = 0; i < tests.length; i += 3) {
if (tests[i].search(new RegExp(tests[i + 1])) != tests[i + 2]) {
return false;
}
}
return true;
}();
// Common tokens in XML 1.0 and XML 1.1.
var XML_S = '[ \t\r\n]+';
var XML_EQ = '(' + XML_S + ')?=(' + XML_S + ')?';
var XML_CHAR_REF = '&#[0-9]+;|&#x[0-9a-fA-F]+;';
// XML 1.0 tokens.
var XML10_VERSION_INFO = XML_S + 'version' + XML_EQ + '("1\\.0"|' + "'1\\.0')";
var XML10_BASE_CHAR = (REGEXP_UNICODE) ?
'\u0041-\u005a\u0061-\u007a\u00c0-\u00d6\u00d8-\u00f6\u00f8-\u00ff' +
'\u0100-\u0131\u0134-\u013e\u0141-\u0148\u014a-\u017e\u0180-\u01c3' +
'\u01cd-\u01f0\u01f4-\u01f5\u01fa-\u0217\u0250-\u02a8\u02bb-\u02c1\u0386' +
'\u0388-\u038a\u038c\u038e-\u03a1\u03a3-\u03ce\u03d0-\u03d6\u03da\u03dc' +
'\u03de\u03e0\u03e2-\u03f3\u0401-\u040c\u040e-\u044f\u0451-\u045c' +
'\u045e-\u0481\u0490-\u04c4\u04c7-\u04c8\u04cb-\u04cc\u04d0-\u04eb' +
'\u04ee-\u04f5\u04f8-\u04f9\u0531-\u0556\u0559\u0561-\u0586\u05d0-\u05ea' +
'\u05f0-\u05f2\u0621-\u063a\u0641-\u064a\u0671-\u06b7\u06ba-\u06be' +
'\u06c0-\u06ce\u06d0-\u06d3\u06d5\u06e5-\u06e6\u0905-\u0939\u093d' +
'\u0958-\u0961\u0985-\u098c\u098f-\u0990\u0993-\u09a8\u09aa-\u09b0\u09b2' +
'\u09b6-\u09b9\u09dc-\u09dd\u09df-\u09e1\u09f0-\u09f1\u0a05-\u0a0a' +
'\u0a0f-\u0a10\u0a13-\u0a28\u0a2a-\u0a30\u0a32-\u0a33\u0a35-\u0a36' +
'\u0a38-\u0a39\u0a59-\u0a5c\u0a5e\u0a72-\u0a74\u0a85-\u0a8b\u0a8d' +
'\u0a8f-\u0a91\u0a93-\u0aa8\u0aaa-\u0ab0\u0ab2-\u0ab3\u0ab5-\u0ab9' +
'\u0abd\u0ae0\u0b05-\u0b0c\u0b0f-\u0b10\u0b13-\u0b28\u0b2a-\u0b30' +
'\u0b32-\u0b33\u0b36-\u0b39\u0b3d\u0b5c-\u0b5d\u0b5f-\u0b61\u0b85-\u0b8a' +
'\u0b8e-\u0b90\u0b92-\u0b95\u0b99-\u0b9a\u0b9c\u0b9e-\u0b9f\u0ba3-\u0ba4' +
'\u0ba8-\u0baa\u0bae-\u0bb5\u0bb7-\u0bb9\u0c05-\u0c0c\u0c0e-\u0c10' +
'\u0c12-\u0c28\u0c2a-\u0c33\u0c35-\u0c39\u0c60-\u0c61\u0c85-\u0c8c' +
'\u0c8e-\u0c90\u0c92-\u0ca8\u0caa-\u0cb3\u0cb5-\u0cb9\u0cde\u0ce0-\u0ce1' +
'\u0d05-\u0d0c\u0d0e-\u0d10\u0d12-\u0d28\u0d2a-\u0d39\u0d60-\u0d61' +
'\u0e01-\u0e2e\u0e30\u0e32-\u0e33\u0e40-\u0e45\u0e81-\u0e82\u0e84' +
'\u0e87-\u0e88\u0e8a\u0e8d\u0e94-\u0e97\u0e99-\u0e9f\u0ea1-\u0ea3\u0ea5' +
'\u0ea7\u0eaa-\u0eab\u0ead-\u0eae\u0eb0\u0eb2-\u0eb3\u0ebd\u0ec0-\u0ec4' +
'\u0f40-\u0f47\u0f49-\u0f69\u10a0-\u10c5\u10d0-\u10f6\u1100\u1102-\u1103' +
'\u1105-\u1107\u1109\u110b-\u110c\u110e-\u1112\u113c\u113e\u1140\u114c' +
'\u114e\u1150\u1154-\u1155\u1159\u115f-\u1161\u1163\u1165\u1167\u1169' +
'\u116d-\u116e\u1172-\u1173\u1175\u119e\u11a8\u11ab\u11ae-\u11af' +
'\u11b7-\u11b8\u11ba\u11bc-\u11c2\u11eb\u11f0\u11f9\u1e00-\u1e9b' +
'\u1ea0-\u1ef9\u1f00-\u1f15\u1f18-\u1f1d\u1f20-\u1f45\u1f48-\u1f4d' +
'\u1f50-\u1f57\u1f59\u1f5b\u1f5d\u1f5f-\u1f7d\u1f80-\u1fb4\u1fb6-\u1fbc' +
'\u1fbe\u1fc2-\u1fc4\u1fc6-\u1fcc\u1fd0-\u1fd3\u1fd6-\u1fdb\u1fe0-\u1fec' +
'\u1ff2-\u1ff4\u1ff6-\u1ffc\u2126\u212a-\u212b\u212e\u2180-\u2182' +
'\u3041-\u3094\u30a1-\u30fa\u3105-\u312c\uac00-\ud7a3' :
'A-Za-z';
var XML10_IDEOGRAPHIC = (REGEXP_UNICODE) ?
'\u4e00-\u9fa5\u3007\u3021-\u3029' :
'';
var XML10_COMBINING_CHAR = (REGEXP_UNICODE) ?
'\u0300-\u0345\u0360-\u0361\u0483-\u0486\u0591-\u05a1\u05a3-\u05b9' +
'\u05bb-\u05bd\u05bf\u05c1-\u05c2\u05c4\u064b-\u0652\u0670\u06d6-\u06dc' +
'\u06dd-\u06df\u06e0-\u06e4\u06e7-\u06e8\u06ea-\u06ed\u0901-\u0903\u093c' +
'\u093e-\u094c\u094d\u0951-\u0954\u0962-\u0963\u0981-\u0983\u09bc\u09be' +
'\u09bf\u09c0-\u09c4\u09c7-\u09c8\u09cb-\u09cd\u09d7\u09e2-\u09e3\u0a02' +
'\u0a3c\u0a3e\u0a3f\u0a40-\u0a42\u0a47-\u0a48\u0a4b-\u0a4d\u0a70-\u0a71' +
'\u0a81-\u0a83\u0abc\u0abe-\u0ac5\u0ac7-\u0ac9\u0acb-\u0acd\u0b01-\u0b03' +
'\u0b3c\u0b3e-\u0b43\u0b47-\u0b48\u0b4b-\u0b4d\u0b56-\u0b57\u0b82-\u0b83' +
'\u0bbe-\u0bc2\u0bc6-\u0bc8\u0bca-\u0bcd\u0bd7\u0c01-\u0c03\u0c3e-\u0c44' +
'\u0c46-\u0c48\u0c4a-\u0c4d\u0c55-\u0c56\u0c82-\u0c83\u0cbe-\u0cc4' +
'\u0cc6-\u0cc8\u0cca-\u0ccd\u0cd5-\u0cd6\u0d02-\u0d03\u0d3e-\u0d43' +
'\u0d46-\u0d48\u0d4a-\u0d4d\u0d57\u0e31\u0e34-\u0e3a\u0e47-\u0e4e\u0eb1' +
'\u0eb4-\u0eb9\u0ebb-\u0ebc\u0ec8-\u0ecd\u0f18-\u0f19\u0f35\u0f37\u0f39' +
'\u0f3e\u0f3f\u0f71-\u0f84\u0f86-\u0f8b\u0f90-\u0f95\u0f97\u0f99-\u0fad' +
'\u0fb1-\u0fb7\u0fb9\u20d0-\u20dc\u20e1\u302a-\u302f\u3099\u309a' :
'';
var XML10_DIGIT = (REGEXP_UNICODE) ?
'\u0030-\u0039\u0660-\u0669\u06f0-\u06f9\u0966-\u096f\u09e6-\u09ef' +
'\u0a66-\u0a6f\u0ae6-\u0aef\u0b66-\u0b6f\u0be7-\u0bef\u0c66-\u0c6f' +
'\u0ce6-\u0cef\u0d66-\u0d6f\u0e50-\u0e59\u0ed0-\u0ed9\u0f20-\u0f29' :
'0-9';
var XML10_EXTENDER = (REGEXP_UNICODE) ?
'\u00b7\u02d0\u02d1\u0387\u0640\u0e46\u0ec6\u3005\u3031-\u3035' +
'\u309d-\u309e\u30fc-\u30fe' :
'';
var XML10_LETTER = XML10_BASE_CHAR + XML10_IDEOGRAPHIC;
var XML10_NAME_CHAR = XML10_LETTER + XML10_DIGIT + '\\._:' +
XML10_COMBINING_CHAR + XML10_EXTENDER + '-';
var XML10_NAME = '[' + XML10_LETTER + '_:][' + XML10_NAME_CHAR + ']*';
var XML10_ENTITY_REF = '&' + XML10_NAME + ';';
var XML10_REFERENCE = XML10_ENTITY_REF + '|' + XML_CHAR_REF;
var XML10_ATT_VALUE = '"(([^<&"]|' + XML10_REFERENCE + ')*)"|' +
"'(([^<&']|" + XML10_REFERENCE + ")*)'";
var XML10_ATTRIBUTE =
'(' + XML10_NAME + ')' + XML_EQ + '(' + XML10_ATT_VALUE + ')';
// XML 1.1 tokens.
// TODO(jtakagi): NameStartChar also includes \u10000-\ueffff.
// ECMAScript Language Specifiction defines UnicodeEscapeSequence as
// "\u HexDigit HexDigit HexDigit HexDigit" and we may need to use
// surrogate pairs, but any browser doesn't support surrogate paris in
// character classes of regular expression, so avoid including them for now.
var XML11_VERSION_INFO = XML_S + 'version' + XML_EQ + '("1\\.1"|' + "'1\\.1')";
var XML11_NAME_START_CHAR = (REGEXP_UNICODE) ?
':A-Z_a-z\u00c0-\u00d6\u00d8-\u00f6\u00f8-\u02ff\u0370-\u037d' +
'\u037f-\u1fff\u200c-\u200d\u2070-\u218f\u2c00-\u2fef\u3001-\ud7ff' +
'\uf900-\ufdcf\ufdf0-\ufffd' :
':A-Z_a-z';
var XML11_NAME_CHAR = XML11_NAME_START_CHAR +
((REGEXP_UNICODE) ? '\\.0-9\u00b7\u0300-\u036f\u203f-\u2040-' : '\\.0-9-');
var XML11_NAME = '[' + XML11_NAME_START_CHAR + '][' + XML11_NAME_CHAR + ']*';
var XML11_ENTITY_REF = '&' + XML11_NAME + ';';
var XML11_REFERENCE = XML11_ENTITY_REF + '|' + XML_CHAR_REF;
var XML11_ATT_VALUE = '"(([^<&"]|' + XML11_REFERENCE + ')*)"|' +
"'(([^<&']|" + XML11_REFERENCE + ")*)'";
var XML11_ATTRIBUTE =
'(' + XML11_NAME + ')' + XML_EQ + '(' + XML11_ATT_VALUE + ')';
// XML Namespace tokens.
// Used in XML parser and XPath parser.
var XML_NC_NAME_CHAR = XML10_LETTER + XML10_DIGIT + '\\._' +
XML10_COMBINING_CHAR + XML10_EXTENDER + '-';
var XML_NC_NAME = '[' + XML10_LETTER + '_][' + XML_NC_NAME_CHAR + ']*';
// Code from dom.js.
//
// Based on <http://www.w3.org/TR/2000/REC-DOM-Level-2-Core-20001113/
// core.html#ID-1950641247>
var DOM_ELEMENT_NODE = 1;
var DOM_ATTRIBUTE_NODE = 2;
var DOM_TEXT_NODE = 3;
var DOM_CDATA_SECTION_NODE = 4;
var DOM_ENTITY_REFERENCE_NODE = 5;
var DOM_ENTITY_NODE = 6;
var DOM_PROCESSING_INSTRUCTION_NODE = 7;
var DOM_COMMENT_NODE = 8;
var DOM_DOCUMENT_NODE = 9;
var DOM_DOCUMENT_TYPE_NODE = 10;
var DOM_DOCUMENT_FRAGMENT_NODE = 11;
var DOM_NOTATION_NODE = 12;
// Code from util.js.
//
// Copyright 2005 Google
//
// Author: Steffen Meschkat <mesch@google.com>
//
// Miscellaneous utility and placeholder functions.
// Dummy implmentation for the logging functions. Replace by something
// useful when you want to debug.
function xpathLog(msg) {}
function xsltLog(msg) {}
function xsltLogXml(msg) {}
// Throws an exception if false.
function assert(b) {
if (!b) {
throw "Assertion failed";
}
}
// Splits a string s at all occurrences of character c. This is like
// the split() method of the string object, but IE omits empty
// strings, which violates the invariant (s.split(x).join(x) == s).
function stringSplit(s, c) {
var a = s.indexOf(c);
if (a == -1) {
return [ s ];
}
var parts = [];
parts.push(s.substr(0,a));
while (a != -1) {
var a1 = s.indexOf(c, a + 1);
if (a1 != -1) {
parts.push(s.substr(a + 1, a1 - a - 1));
} else {
parts.push(s.substr(a + 1));
}
a = a1;
}
return parts;
}
// Applies the given function to each element of the array, preserving
// this, and passing the index.
function mapExec(array, func) {
for (var i = 0; i < array.length; ++i) {
func.call(this, array[i], i);
}
}
// Returns an array that contains the return value of the given
// function applied to every element of the input array.
function mapExpr(array, func) {
var ret = [];
for (var i = 0; i < array.length; ++i) {
ret.push(func(array[i]));
}
return ret;
}
// Reverses the given array in place.
function reverseInplace(array) {
for (var i = 0; i < array.length / 2; ++i) {
var h = array[i];
var ii = array.length - i - 1;
array[i] = array[ii];
array[ii] = h;
}
}
// Removes value from array. Returns the number of instances of value
// that were removed from array.
function removeFromArray(array, value, opt_notype) {
var shift = 0;
for (var i = 0; i < array.length; ++i) {
if (array[i] === value || (opt_notype && array[i] == value)) {
array.splice(i--, 1);
shift++;
}
}
return shift;
}
// Shallow-copies an array.
function copyArray(dst, src) {
for (var i = 0; i < src.length; ++i) {
dst.push(src[i]);
}
}
// Returns the text value of a node; for nodes without children this
// is the nodeValue, for nodes with children this is the concatenation
// of the value of all children.
function xmlValue(node) {
if (!node) {
return '';
}
var ret = '';
if (node.nodeType == DOM_TEXT_NODE ||
node.nodeType == DOM_CDATA_SECTION_NODE ||
node.nodeType == DOM_ATTRIBUTE_NODE) {
ret += node.nodeValue;
} else if (node.nodeType == DOM_ELEMENT_NODE ||
node.nodeType == DOM_DOCUMENT_NODE ||
node.nodeType == DOM_DOCUMENT_FRAGMENT_NODE) {
for (var i = 0; i < node.childNodes.length; ++i) {
ret += arguments.callee(node.childNodes[i]);
}
}
return ret;
}
// Code from xpath.js.
//
// Copyright 2005 Google Inc.
// All Rights Reserved
//
// An XPath parser and evaluator written in JavaScript. The
// implementation is complete except for functions handling
// namespaces.
//
// Reference: [XPATH] XPath Specification
// <http://www.w3.org/TR/1999/REC-xpath-19991116>.
//
//
// The API of the parser has several parts:
//
// 1. The parser function xpathParse() that takes a string and returns
// an expession object.
//
// 2. The expression object that has an evaluate() method to evaluate the
// XPath expression it represents. (It is actually a hierarchy of
// objects that resembles the parse tree, but an application will call
// evaluate() only on the top node of this hierarchy.)
//
// 3. The context object that is passed as an argument to the evaluate()
// method, which represents the DOM context in which the expression is
// evaluated.
//
// 4. The value object that is returned from evaluate() and represents
// values of the different types that are defined by XPath (number,
// string, boolean, and node-set), and allows to convert between them.
//
// These parts are near the top of the file, the functions and data
// that are used internally follow after them.
//
//
// Author: Steffen Meschkat <mesch@google.com>
// The entry point for the parser.
//
// @param expr a string that contains an XPath expression.
// @return an expression object that can be evaluated with an
// expression context.
function xpathParse(expr) {
xpathLog('parse ' + expr);
xpathParseInit();
var cached = xpathCacheLookup(expr);
if (cached) {
xpathLog(' ... cached');
return cached;
}
// Optimize for a few common cases: simple attribute node tests
// (@id), simple element node tests (page), variable references
// ($address), numbers (4), multi-step path expressions where each
// step is a plain element node test
// (page/overlay/locations/location).
if (expr.match(/^(\$|@)?\w+$/i)) {
var ret = makeSimpleExpr(expr);
xpathParseCache[expr] = ret;
xpathLog(' ... simple');
return ret;
}
if (expr.match(/^\w+(\/\w+)*$/i)) {
var ret = makeSimpleExpr2(expr);
xpathParseCache[expr] = ret;
xpathLog(' ... simple 2');
return ret;
}
var cachekey = expr; // expr is modified during parse
var stack = [];
var ahead = null;
var previous = null;
var done = false;
var parse_count = 0;
var lexer_count = 0;
var reduce_count = 0;
while (!done) {
parse_count++;
expr = expr.replace(/^\s*/, '');
previous = ahead;
ahead = null;
var rule = null;
var match = '';
for (var i = 0; i < xpathTokenRules.length; ++i) {
var result = xpathTokenRules[i].re.exec(expr);
lexer_count++;
if (result && result.length > 0 && result[0].length > match.length) {
rule = xpathTokenRules[i];
match = result[0];
break;
}
}
// Special case: allow operator keywords to be element and
// variable names.
// NOTE(mesch): The parser resolves conflicts by looking ahead,
// and this is the only case where we look back to
// disambiguate. So this is indeed something different, and
// looking back is usually done in the lexer (via states in the
// general case, called "start conditions" in flex(1)). Also,the
// conflict resolution in the parser is not as robust as it could
// be, so I'd like to keep as much off the parser as possible (all
// these precedence values should be computed from the grammar
// rules and possibly associativity declarations, as in bison(1),
// and not explicitly set.
if (rule &&
(rule == TOK_DIV ||
rule == TOK_MOD ||
rule == TOK_AND ||
rule == TOK_OR) &&
(!previous ||
previous.tag == TOK_AT ||
previous.tag == TOK_DSLASH ||
previous.tag == TOK_SLASH ||
previous.tag == TOK_AXIS ||
previous.tag == TOK_DOLLAR)) {
rule = TOK_QNAME;
}
if (rule) {
expr = expr.substr(match.length);
xpathLog('token: ' + match + ' -- ' + rule.label);
ahead = {
tag: rule,
match: match,
prec: rule.prec ? rule.prec : 0, // || 0 is removed by the compiler
expr: makeTokenExpr(match)
};
} else {
xpathLog('DONE');
done = true;
}
while (xpathReduce(stack, ahead)) {
reduce_count++;
xpathLog('stack: ' + stackToString(stack));
}
}
xpathLog('stack: ' + stackToString(stack));
if (stack.length != 1) {
throw 'XPath parse error ' + cachekey + ':\n' + stackToString(stack);
}
var result = stack[0].expr;
xpathParseCache[cachekey] = result;
xpathLog('XPath parse: ' + parse_count + ' / ' +
lexer_count + ' / ' + reduce_count);
return result;
}
var xpathParseCache = {};
function xpathCacheLookup(expr) {
return xpathParseCache[expr];
}
function xpathReduce(stack, ahead) {
var cand = null;
if (stack.length > 0) {
var top = stack[stack.length-1];
var ruleset = xpathRules[top.tag.key];
if (ruleset) {
for (var i = 0; i < ruleset.length; ++i) {
var rule = ruleset[i];
var match = xpathMatchStack(stack, rule[1]);
if (match.length) {
cand = {
tag: rule[0],
rule: rule,
match: match
};
cand.prec = xpathGrammarPrecedence(cand);
break;
}
}
}
}
var ret;
if (cand && (!ahead || cand.prec > ahead.prec ||
(ahead.tag.left && cand.prec >= ahead.prec))) {
for (var i = 0; i < cand.match.matchlength; ++i) {
stack.pop();
}
xpathLog('reduce ' + cand.tag.label + ' ' + cand.prec +
' ahead ' + (ahead ? ahead.tag.label + ' ' + ahead.prec +
(ahead.tag.left ? ' left' : '')
: ' none '));
var matchexpr = mapExpr(cand.match, function(m) { return m.expr; });
cand.expr = cand.rule[3].apply(null, matchexpr);
stack.push(cand);
ret = true;
} else {
if (ahead) {
xpathLog('shift ' + ahead.tag.label + ' ' + ahead.prec +
(ahead.tag.left ? ' left' : '') +
' over ' + (cand ? cand.tag.label + ' ' +
cand.prec : ' none'));
stack.push(ahead);
}
ret = false;
}
return ret;
}
function xpathMatchStack(stack, pattern) {
// NOTE(mesch): The stack matches for variable cardinality are
// greedy but don't do backtracking. This would be an issue only
// with rules of the form A* A, i.e. with an element with variable
// cardinality followed by the same element. Since that doesn't
// occur in the grammar at hand, all matches on the stack are
// unambiguous.
var S = stack.length;
var P = pattern.length;
var p, s;
var match = [];
match.matchlength = 0;
var ds = 0;
for (p = P - 1, s = S - 1; p >= 0 && s >= 0; --p, s -= ds) {
ds = 0;
var qmatch = [];
if (pattern[p] == Q_MM) {
p -= 1;
match.push(qmatch);
while (s - ds >= 0 && stack[s - ds].tag == pattern[p]) {
qmatch.push(stack[s - ds]);
ds += 1;
match.matchlength += 1;
}
} else if (pattern[p] == Q_01) {
p -= 1;
match.push(qmatch);
while (s - ds >= 0 && ds < 2 && stack[s - ds].tag == pattern[p]) {
qmatch.push(stack[s - ds]);
ds += 1;
match.matchlength += 1;
}
} else if (pattern[p] == Q_1M) {
p -= 1;
match.push(qmatch);
if (stack[s].tag == pattern[p]) {
while (s - ds >= 0 && stack[s - ds].tag == pattern[p]) {
qmatch.push(stack[s - ds]);
ds += 1;
match.matchlength += 1;
}
} else {
return [];
}
} else if (stack[s].tag == pattern[p]) {
match.push(stack[s]);
ds += 1;
match.matchlength += 1;
} else {
return [];
}
reverseInplace(qmatch);
qmatch.expr = mapExpr(qmatch, function(m) { return m.expr; });
}
reverseInplace(match);
if (p == -1) {
return match;
} else {
return [];
}
}
function xpathTokenPrecedence(tag) {
return tag.prec || 2;
}
function xpathGrammarPrecedence(frame) {
var ret = 0;
if (frame.rule) { /* normal reduce */
if (frame.rule.length >= 3 && frame.rule[2] >= 0) {
ret = frame.rule[2];
} else {
for (var i = 0; i < frame.rule[1].length; ++i) {
var p = xpathTokenPrecedence(frame.rule[1][i]);
ret = Math.max(ret, p);
}
}
} else if (frame.tag) { /* TOKEN match */
ret = xpathTokenPrecedence(frame.tag);
} else if (frame.length) { /* Q_ match */
for (var j = 0; j < frame.length; ++j) {
var p = xpathGrammarPrecedence(frame[j]);
ret = Math.max(ret, p);
}
}
return ret;
}
function stackToString(stack) {
var ret = '';
for (var i = 0; i < stack.length; ++i) {
if (ret) {
ret += '\n';
}
ret += stack[i].tag.label;
}
return ret;
}
// XPath expression evaluation context. An XPath context consists of a
// DOM node, a list of DOM nodes that contains this node, a number
// that represents the position of the single node in the list, and a
// current set of variable bindings. (See XPath spec.)
//
// The interface of the expression context:
//
// Constructor -- gets the node, its position, the node set it
// belongs to, and a parent context as arguments. The parent context
// is used to implement scoping rules for variables: if a variable
// is not found in the current context, it is looked for in the
// parent context, recursively. Except for node, all arguments have
// default values: default position is 0, default node set is the
// set that contains only the node, and the default parent is null.
//
// Notice that position starts at 0 at the outside interface;
// inside XPath expressions this shows up as position()=1.
//
// clone() -- creates a new context with the current context as
// parent. If passed as argument to clone(), the new context has a
// different node, position, or node set. What is not passed is
// inherited from the cloned context.
//
// setVariable(name, expr) -- binds given XPath expression to the
// name.
//
// getVariable(name) -- what the name says.
//
// setNode(position) -- sets the context to the node at the given
// position. Needed to implement scoping rules for variables in
// XPath. (A variable is visible to all subsequent siblings, not
// only to its children.)
function ExprContext(node, opt_position, opt_nodelist, opt_parent) {
this.node = node;
this.position = opt_position || 0;
this.nodelist = opt_nodelist || [ node ];
this.variables = {};
this.parent = opt_parent || null;
if (opt_parent) {
this.root = opt_parent.root;
} else if (this.node.nodeType == DOM_DOCUMENT_NODE) {
// NOTE(mesch): DOM Spec stipulates that the ownerDocument of a
// document is null. Our root, however is the document that we are
// processing, so the initial context is created from its document
// node, which case we must handle here explcitly.
this.root = node;
} else {
this.root = node.ownerDocument;
}
}
ExprContext.prototype.clone = function(opt_node, opt_position, opt_nodelist) {
return new ExprContext(
opt_node || this.node,
typeof opt_position != 'undefined' ? opt_position : this.position,
opt_nodelist || this.nodelist, this);
};
ExprContext.prototype.setVariable = function(name, value) {
this.variables[name] = value;
};
ExprContext.prototype.getVariable = function(name) {
if (typeof this.variables[name] != 'undefined') {
return this.variables[name];
} else if (this.parent) {
return this.parent.getVariable(name);
} else {
return null;
}
};
ExprContext.prototype.setNode = function(position) {
this.node = this.nodelist[position];
this.position = position;
};
ExprContext.prototype.contextSize = function() {
return this.nodelist.length;
};
// XPath expression values. They are what XPath expressions evaluate
// to. Strangely, the different value types are not specified in the
// XPath syntax, but only in the semantics, so they don't show up as
// nonterminals in the grammar. Yet, some expressions are required to
// evaluate to particular types, and not every type can be coerced
// into every other type. Although the types of XPath values are
// similar to the types present in JavaScript, the type coercion rules
// are a bit peculiar, so we explicitly model XPath types instead of
// mapping them onto JavaScript types. (See XPath spec.)
//
// The four types are:
//
// StringValue
//
// NumberValue
//
// BooleanValue
//
// NodeSetValue
//
// The common interface of the value classes consists of methods that
// implement the XPath type coercion rules:
//
// stringValue() -- returns the value as a JavaScript String,
//
// numberValue() -- returns the value as a JavaScript Number,
//
// booleanValue() -- returns the value as a JavaScript Boolean,
//
// nodeSetValue() -- returns the value as a JavaScript Array of DOM
// Node objects.
//
function StringValue(value) {
this.value = value;
this.type = 'string';
}
StringValue.prototype.stringValue = function() {
return this.value;
};
StringValue.prototype.booleanValue = function() {
return this.value.length > 0;
};
StringValue.prototype.numberValue = function() {
return this.value - 0;
};
StringValue.prototype.nodeSetValue = function() {
throw this;
};
function BooleanValue(value) {
this.value = value;
this.type = 'boolean';
}
BooleanValue.prototype.stringValue = function() {
return '' + this.value;
};
BooleanValue.prototype.booleanValue = function() {
return this.value;
};
BooleanValue.prototype.numberValue = function() {
return this.value ? 1 : 0;
};
BooleanValue.prototype.nodeSetValue = function() {
throw this;
};
function NumberValue(value) {
this.value = value;
this.type = 'number';
}
NumberValue.prototype.stringValue = function() {
return '' + this.value;
};
NumberValue.prototype.booleanValue = function() {
return !!this.value;
};
NumberValue.prototype.numberValue = function() {
return this.value - 0;
};
NumberValue.prototype.nodeSetValue = function() {
throw this;
};
function NodeSetValue(value) {
this.value = value;
this.type = 'node-set';
}
NodeSetValue.prototype.stringValue = function() {
if (this.value.length == 0) {
return '';
} else {
return xmlValue(this.value[0]);
}
};
NodeSetValue.prototype.booleanValue = function() {
return this.value.length > 0;
};
NodeSetValue.prototype.numberValue = function() {
return this.stringValue() - 0;
};
NodeSetValue.prototype.nodeSetValue = function() {
return this.value;
};
// XPath expressions. They are used as nodes in the parse tree and
// possess an evaluate() method to compute an XPath value given an XPath
// context. Expressions are returned from the parser. Teh set of
// expression classes closely mirrors the set of non terminal symbols
// in the grammar. Every non trivial nonterminal symbol has a
// corresponding expression class.
//
// The common expression interface consists of the following methods:
//
// evaluate(context) -- evaluates the expression, returns a value.
//
// toString() -- returns the XPath text representation of the
// expression (defined in xsltdebug.js).
//
// parseTree(indent) -- returns a parse tree representation of the
// expression (defined in xsltdebug.js).
function TokenExpr(m) {
this.value = m;
}
TokenExpr.prototype.evaluate = function() {
return new StringValue(this.value);
};
function LocationExpr() {
this.absolute = false;
this.steps = [];
}
LocationExpr.prototype.appendStep = function(s) {
this.steps.push(s);
};
LocationExpr.prototype.prependStep = function(s) {
var steps0 = this.steps;
this.steps = [ s ];
for (var i = 0; i < steps0.length; ++i) {
this.steps.push(steps0[i]);
}
};
LocationExpr.prototype.evaluate = function(ctx) {
var start;
if (this.absolute) {
start = ctx.root;
} else {
start = ctx.node;
}
var nodes = [];
xPathStep(nodes, this.steps, 0, start, ctx);
return new NodeSetValue(nodes);
};
function xPathStep(nodes, steps, step, input, ctx) {
var s = steps[step];
var ctx2 = ctx.clone(input);
var nodelist = s.evaluate(ctx2).nodeSetValue();
for (var i = 0; i < nodelist.length; ++i) {
if (step == steps.length - 1) {
nodes.push(nodelist[i]);
} else {
xPathStep(nodes, steps, step + 1, nodelist[i], ctx);
}
}
}
function StepExpr(axis, nodetest, opt_predicate) {
this.axis = axis;
this.nodetest = nodetest;
this.predicate = opt_predicate || [];
}
StepExpr.prototype.appendPredicate = function(p) {
this.predicate.push(p);
};
StepExpr.prototype.evaluate = function(ctx) {
var input = ctx.node;
var nodelist = [];
// NOTE(mesch): When this was a switch() statement, it didn't work
// in Safari/2.0. Not sure why though; it resulted in the JavaScript
// console output "undefined" (without any line number or so).
if (this.axis == xpathAxis.ANCESTOR_OR_SELF) {
nodelist.push(input);
for (var n = input.parentNode; n; n = n.parentNode) {
nodelist.push(n);
}
} else if (this.axis == xpathAxis.ANCESTOR) {
for (var n = input.parentNode; n; n = n.parentNode) {
nodelist.push(n);
}
} else if (this.axis == xpathAxis.ATTRIBUTE) {
copyArray(nodelist, input.attributes);
} else if (this.axis == xpathAxis.CHILD) {
copyArray(nodelist, input.childNodes);
} else if (this.axis == xpathAxis.DESCENDANT_OR_SELF) {
nodelist.push(input);
xpathCollectDescendants(nodelist, input);
} else if (this.axis == xpathAxis.DESCENDANT) {
xpathCollectDescendants(nodelist, input);
} else if (this.axis == xpathAxis.FOLLOWING) {
for (var n = input; n; n = n.parentNode) {
for (var nn = n.nextSibling; nn; nn = nn.nextSibling) {
nodelist.push(nn);
xpathCollectDescendants(nodelist, nn);
}
}
} else if (this.axis == xpathAxis.FOLLOWING_SIBLING) {
for (var n = input.nextSibling; n; n = n.nextSibling) {
nodelist.push(n);
}
} else if (this.axis == xpathAxis.NAMESPACE) {
alert('not implemented: axis namespace');
} else if (this.axis == xpathAxis.PARENT) {
if (input.parentNode) {
nodelist.push(input.parentNode);
}
} else if (this.axis == xpathAxis.PRECEDING) {
for (var n = input; n; n = n.parentNode) {
for (var nn = n.previousSibling; nn; nn = nn.previousSibling) {
nodelist.push(nn);
xpathCollectDescendantsReverse(nodelist, nn);
}
}
} else if (this.axis == xpathAxis.PRECEDING_SIBLING) {
for (var n = input.previousSibling; n; n = n.previousSibling) {
nodelist.push(n);
}
} else if (this.axis == xpathAxis.SELF) {
nodelist.push(input);
} else {
throw 'ERROR -- NO SUCH AXIS: ' + this.axis;
}
// process node test
var nodelist0 = nodelist;
nodelist = [];
for (var i = 0; i < nodelist0.length; ++i) {
var n = nodelist0[i];
if (this.nodetest.evaluate(ctx.clone(n, i, nodelist0)).booleanValue()) {
nodelist.push(n);
}
}
// process predicates
for (var i = 0; i < this.predicate.length; ++i) {
var nodelist0 = nodelist;
nodelist = [];
for (var ii = 0; ii < nodelist0.length; ++ii) {
var n = nodelist0[ii];
if (this.predicate[i].evaluate(ctx.clone(n, ii, nodelist0)).booleanValue()) {
nodelist.push(n);
}
}
}
return new NodeSetValue(nodelist);
};
function NodeTestAny() {
this.value = new BooleanValue(true);
}
NodeTestAny.prototype.evaluate = function(ctx) {
return this.value;
};
function NodeTestElementOrAttribute() {}
NodeTestElementOrAttribute.prototype.evaluate = function(ctx) {
return new BooleanValue(
ctx.node.nodeType == DOM_ELEMENT_NODE ||
ctx.node.nodeType == DOM_ATTRIBUTE_NODE);
};
function NodeTestText() {}
NodeTestText.prototype.evaluate = function(ctx) {
return new BooleanValue(ctx.node.nodeType == DOM_TEXT_NODE);
};
function NodeTestComment() {}
NodeTestComment.prototype.evaluate = function(ctx) {
return new BooleanValue(ctx.node.nodeType == DOM_COMMENT_NODE);
};
function NodeTestPI(target) {
this.target = target;
}
NodeTestPI.prototype.evaluate = function(ctx) {
return new
BooleanValue(ctx.node.nodeType == DOM_PROCESSING_INSTRUCTION_NODE &&
(!this.target || ctx.node.nodeName == this.target));
};
function NodeTestNC(nsprefix) {
this.regex = new RegExp("^" + nsprefix + ":");
this.nsprefix = nsprefix;
}
NodeTestNC.prototype.evaluate = function(ctx) {
var n = ctx.node;
return new BooleanValue(this.regex.match(n.nodeName));
};
function NodeTestName(name) {
this.name = name;
}
NodeTestName.prototype.evaluate = function(ctx) {
var n = ctx.node;
return new BooleanValue(n.nodeName == this.name);
};
function PredicateExpr(expr) {
this.expr = expr;
}
PredicateExpr.prototype.evaluate = function(ctx) {
var v = this.expr.evaluate(ctx);
if (v.type == 'number') {
// NOTE(mesch): Internally, position is represented starting with
// 0, however in XPath position starts with 1. See functions
// position() and last().
return new BooleanValue(ctx.position == v.numberValue() - 1);
} else {
return new BooleanValue(v.booleanValue());
}
};
function FunctionCallExpr(name) {
this.name = name;
this.args = [];
}
FunctionCallExpr.prototype.appendArg = function(arg) {
this.args.push(arg);
};
FunctionCallExpr.prototype.evaluate = function(ctx) {
var fn = '' + this.name.value;
var f = this.xpathfunctions[fn];
if (f) {
return f.call(this, ctx);
} else {
xpathLog('XPath NO SUCH FUNCTION ' + fn);
return new BooleanValue(false);
}
};
FunctionCallExpr.prototype.xpathfunctions = {
'last': function(ctx) {
assert(this.args.length == 0);
// NOTE(mesch): XPath position starts at 1.
return new NumberValue(ctx.contextSize());
},
'position': function(ctx) {
assert(this.args.length == 0);
// NOTE(mesch): XPath position starts at 1.
return new NumberValue(ctx.position + 1);
},
'count': function(ctx) {
assert(this.args.length == 1);
var v = this.args[0].evaluate(ctx);
return new NumberValue(v.nodeSetValue().length);
},
'id': function(ctx) {
assert(this.args.length == 1);
var e = this.args[0].evaluate(ctx);
var ret = [];
var ids;
if (e.type == 'node-set') {
ids = [];
var en = e.nodeSetValue();
for (var i = 0; i < en.length; ++i) {
var v = xmlValue(en[i]).split(/\s+/);
for (var ii = 0; ii < v.length; ++ii) {
ids.push(v[ii]);
}
}
} else {
ids = e.stringValue().split(/\s+/);
}
var d = ctx.node.ownerDocument;
for (var i = 0; i < ids.length; ++i) {
var n = d.getElementById(ids[i]);
if (n) {
ret.push(n);
}
}
return new NodeSetValue(ret);
},
'local-name': function(ctx) {
alert('not implmented yet: XPath function local-name()');
},
'namespace-uri': function(ctx) {
alert('not implmented yet: XPath function namespace-uri()');
},
'name': function(ctx) {
assert(this.args.length == 1 || this.args.length == 0);
var n;
if (this.args.length == 0) {
n = [ ctx.node ];
} else {
n = this.args[0].evaluate(ctx).nodeSetValue();
}
if (n.length == 0) {
return new StringValue('');
} else {
return new StringValue(n[0].nodeName);
}
},
'string': function(ctx) {
assert(this.args.length == 1 || this.args.length == 0);
if (this.args.length == 0) {
return new StringValue(new NodeSetValue([ ctx.node ]).stringValue());
} else {
return new StringValue(this.args[0].evaluate(ctx).stringValue());
}
},
'concat': function(ctx) {
var ret = '';
for (var i = 0; i < this.args.length; ++i) {
ret += this.args[i].evaluate(ctx).stringValue();
}
return new StringValue(ret);
},
'starts-with': function(ctx) {
assert(this.args.length == 2);
var s0 = this.args[0].evaluate(ctx).stringValue();
var s1 = this.args[1].evaluate(ctx).stringValue();
return new BooleanValue(s0.indexOf(s1) == 0);
},
'contains': function(ctx) {
assert(this.args.length == 2);
var s0 = this.args[0].evaluate(ctx).stringValue();
var s1 = this.args[1].evaluate(ctx).stringValue();
return new BooleanValue(s0.indexOf(s1) != -1);
},
'substring-before': function(ctx) {
assert(this.args.length == 2);
var s0 = this.args[0].evaluate(ctx).stringValue();
var s1 = this.args[1].evaluate(ctx).stringValue();
var i = s0.indexOf(s1);
var ret;
if (i == -1) {
ret = '';
} else {
ret = s0.substr(0,i);
}
return new StringValue(ret);
},
'substring-after': function(ctx) {
assert(this.args.length == 2);
var s0 = this.args[0].evaluate(ctx).stringValue();
var s1 = this.args[1].evaluate(ctx).stringValue();
var i = s0.indexOf(s1);
var ret;
if (i == -1) {
ret = '';
} else {
ret = s0.substr(i + s1.length);
}
return new StringValue(ret);
},
'substring': function(ctx) {
// NOTE: XPath defines the position of the first character in a
// string to be 1, in JavaScript this is 0 ([XPATH] Section 4.2).
assert(this.args.length == 2 || this.args.length == 3);
var s0 = this.args[0].evaluate(ctx).stringValue();
var s1 = this.args[1].evaluate(ctx).numberValue();
var ret;
if (this.args.length == 2) {
var i1 = Math.max(0, Math.round(s1) - 1);
ret = s0.substr(i1);
} else {
var s2 = this.args[2].evaluate(ctx).numberValue();
var i0 = Math.round(s1) - 1;
var i1 = Math.max(0, i0);
var i2 = Math.round(s2) - Math.max(0, -i0);
ret = s0.substr(i1, i2);
}
return new StringValue(ret);
},
'string-length': function(ctx) {
var s;
if (this.args.length > 0) {
s = this.args[0].evaluate(ctx).stringValue();
} else {
s = new NodeSetValue([ ctx.node ]).stringValue();
}
return new NumberValue(s.length);
},
'normalize-space': function(ctx) {
var s;
if (this.args.length > 0) {
s = this.args[0].evaluate(ctx).stringValue();
} else {
s = new NodeSetValue([ ctx.node ]).stringValue();
}
s = s.replace(/^\s*/,'').replace(/\s*$/,'').replace(/\s+/g, ' ');
return new StringValue(s);
},
'translate': function(ctx) {
assert(this.args.length == 3);
var s0 = this.args[0].evaluate(ctx).stringValue();
var s1 = this.args[1].evaluate(ctx).stringValue();
var s2 = this.args[2].evaluate(ctx).stringValue();
for (var i = 0; i < s1.length; ++i) {
s0 = s0.replace(new RegExp(s1.charAt(i), 'g'), s2.charAt(i));
}
return new StringValue(s0);
},
'boolean': function(ctx) {
assert(this.args.length == 1);
return new BooleanValue(this.args[0].evaluate(ctx).booleanValue());
},
'not': function(ctx) {
assert(this.args.length == 1);
var ret = !this.args[0].evaluate(ctx).booleanValue();
return new BooleanValue(ret);
},
'true': function(ctx) {
assert(this.args.length == 0);
return new BooleanValue(true);
},
'false': function(ctx) {
assert(this.args.length == 0);
return new BooleanValue(false);
},
'lang': function(ctx) {
assert(this.args.length == 1);
var lang = this.args[0].evaluate(ctx).stringValue();
var xmllang;
var n = ctx.node;
while (n && n != n.parentNode /* just in case ... */) {
xmllang = n.getAttribute('xml:lang');
if (xmllang) {
break;
}
n = n.parentNode;
}
if (!xmllang) {
return new BooleanValue(false);
} else {
var re = new RegExp('^' + lang + '$', 'i');
return new BooleanValue(xmllang.match(re) ||
xmllang.replace(/_.*$/,'').match(re));
}
},
'number': function(ctx) {
assert(this.args.length == 1 || this.args.length == 0);
if (this.args.length == 1) {
return new NumberValue(this.args[0].evaluate(ctx).numberValue());
} else {
return new NumberValue(new NodeSetValue([ ctx.node ]).numberValue());
}
},
'sum': function(ctx) {
assert(this.args.length == 1);
var n = this.args[0].evaluate(ctx).nodeSetValue();
var sum = 0;
for (var i = 0; i < n.length; ++i) {
sum += xmlValue(n[i]) - 0;
}
return new NumberValue(sum);
},
'floor': function(ctx) {
assert(this.args.length == 1);
var num = this.args[0].evaluate(ctx).numberValue();
return new NumberValue(Math.floor(num));
},
'ceiling': function(ctx) {
assert(this.args.length == 1);
var num = this.args[0].evaluate(ctx).numberValue();
return new NumberValue(Math.ceil(num));
},
'round': function(ctx) {
assert(this.args.length == 1);
var num = this.args[0].evaluate(ctx).numberValue();
return new NumberValue(Math.round(num));
},
// TODO(mesch): The following functions are custom. There is a
// standard that defines how to add functions, which should be
// applied here.
'ext-join': function(ctx) {
assert(this.args.length == 2);
var nodes = this.args[0].evaluate(ctx).nodeSetValue();
var delim = this.args[1].evaluate(ctx).stringValue();
var ret = '';
for (var i = 0; i < nodes.length; ++i) {
if (ret) {
ret += delim;
}
ret += xmlValue(nodes[i]);
}
return new StringValue(ret);
},
// ext-if() evaluates and returns its second argument, if the
// boolean value of its first argument is true, otherwise it
// evaluates and returns its third argument.
'ext-if': function(ctx) {
assert(this.args.length == 3);
if (this.args[0].evaluate(ctx).booleanValue()) {
return this.args[1].evaluate(ctx);
} else {
return this.args[2].evaluate(ctx);
}
},
// ext-cardinal() evaluates its single argument as a number, and
// returns the current node that many times. It can be used in the
// select attribute to iterate over an integer range.
'ext-cardinal': function(ctx) {
assert(this.args.length >= 1);
var c = this.args[0].evaluate(ctx).numberValue();
var ret = [];
for (var i = 0; i < c; ++i) {
ret.push(ctx.node);
}
return new NodeSetValue(ret);
}
};
function UnionExpr(expr1, expr2) {
this.expr1 = expr1;
this.expr2 = expr2;
}
UnionExpr.prototype.evaluate = function(ctx) {
var nodes1 = this.expr1.evaluate(ctx).nodeSetValue();
var nodes2 = this.expr2.evaluate(ctx).nodeSetValue();
var I1 = nodes1.length;
for (var i2 = 0; i2 < nodes2.length; ++i2) {
var n = nodes2[i2];
var inBoth = false;
for (var i1 = 0; i1 < I1; ++i1) {
if (nodes1[i1] == n) {
inBoth = true;
i1 = I1; // break inner loop
}
}
if (!inBoth) {
nodes1.push(n);
}
}
return new NodeSetValue(nodes1);
};
function PathExpr(filter, rel) {
this.filter = filter;
this.rel = rel;
}
PathExpr.prototype.evaluate = function(ctx) {
var nodes = this.filter.evaluate(ctx).nodeSetValue();
var nodes1 = [];
for (var i = 0; i < nodes.length; ++i) {
var nodes0 = this.rel.evaluate(ctx.clone(nodes[i], i, nodes)).nodeSetValue();
for (var ii = 0; ii < nodes0.length; ++ii) {
nodes1.push(nodes0[ii]);
}
}
return new NodeSetValue(nodes1);
};
function FilterExpr(expr, predicate) {
this.expr = expr;
this.predicate = predicate;
}
FilterExpr.prototype.evaluate = function(ctx) {
var nodes = this.expr.evaluate(ctx).nodeSetValue();
for (var i = 0; i < this.predicate.length; ++i) {
var nodes0 = nodes;
nodes = [];
for (var j = 0; j < nodes0.length; ++j) {
var n = nodes0[j];
if (this.predicate[i].evaluate(ctx.clone(n, j, nodes0)).booleanValue()) {
nodes.push(n);
}
}
}
return new NodeSetValue(nodes);
};
function UnaryMinusExpr(expr) {
this.expr = expr;
}
UnaryMinusExpr.prototype.evaluate = function(ctx) {
return new NumberValue(-this.expr.evaluate(ctx).numberValue());
};
function BinaryExpr(expr1, op, expr2) {
this.expr1 = expr1;
this.expr2 = expr2;
this.op = op;
}
BinaryExpr.prototype.evaluate = function(ctx) {
var ret;
switch (this.op.value) {
case 'or':
ret = new BooleanValue(this.expr1.evaluate(ctx).booleanValue() ||
this.expr2.evaluate(ctx).booleanValue());
break;
case 'and':
ret = new BooleanValue(this.expr1.evaluate(ctx).booleanValue() &&
this.expr2.evaluate(ctx).booleanValue());
break;
case '+':
ret = new NumberValue(this.expr1.evaluate(ctx).numberValue() +
this.expr2.evaluate(ctx).numberValue());
break;
case '-':
ret = new NumberValue(this.expr1.evaluate(ctx).numberValue() -
this.expr2.evaluate(ctx).numberValue());
break;
case '*':
ret = new NumberValue(this.expr1.evaluate(ctx).numberValue() *
this.expr2.evaluate(ctx).numberValue());
break;
case 'mod':
ret = new NumberValue(this.expr1.evaluate(ctx).numberValue() %
this.expr2.evaluate(ctx).numberValue());
break;
case 'div':
ret = new NumberValue(this.expr1.evaluate(ctx).numberValue() /
this.expr2.evaluate(ctx).numberValue());
break;
case '=':
ret = this.compare(ctx, function(x1, x2) { return x1 == x2; });
break;
case '!=':
ret = this.compare(ctx, function(x1, x2) { return x1 != x2; });
break;
case '<':
ret = this.compare(ctx, function(x1, x2) { return x1 < x2; });
break;
case '<=':
ret = this.compare(ctx, function(x1, x2) { return x1 <= x2; });
break;
case '>':
ret = this.compare(ctx, function(x1, x2) { return x1 > x2; });
break;
case '>=':
ret = this.compare(ctx, function(x1, x2) { return x1 >= x2; });
break;
default:
alert('BinaryExpr.evaluate: ' + this.op.value);
}
return ret;
};
BinaryExpr.prototype.compare = function(ctx, cmp) {
var v1 = this.expr1.evaluate(ctx);
var v2 = this.expr2.evaluate(ctx);
var ret;
if (v1.type == 'node-set' && v2.type == 'node-set') {
var n1 = v1.nodeSetValue();
var n2 = v2.nodeSetValue();
ret = false;
for (var i1 = 0; i1 < n1.length; ++i1) {
for (var i2 = 0; i2 < n2.length; ++i2) {
if (cmp(xmlValue(n1[i1]), xmlValue(n2[i2]))) {
ret = true;
// Break outer loop. Labels confuse the jscompiler and we
// don't use them.
i2 = n2.length;
i1 = n1.length;
}
}
}
} else if (v1.type == 'node-set' || v2.type == 'node-set') {
if (v1.type == 'number') {
var s = v1.numberValue();
var n = v2.nodeSetValue();
ret = false;
for (var i = 0; i < n.length; ++i) {
var nn = xmlValue(n[i]) - 0;
if (cmp(s, nn)) {
ret = true;
break;
}
}
} else if (v2.type == 'number') {
var n = v1.nodeSetValue();
var s = v2.numberValue();
ret = false;
for (var i = 0; i < n.length; ++i) {
var nn = xmlValue(n[i]) - 0;
if (cmp(nn, s)) {
ret = true;
break;
}
}
} else if (v1.type == 'string') {
var s = v1.stringValue();
var n = v2.nodeSetValue();
ret = false;
for (var i = 0; i < n.length; ++i) {
var nn = xmlValue(n[i]);
if (cmp(s, nn)) {
ret = true;
break;
}
}
} else if (v2.type == 'string') {
var n = v1.nodeSetValue();
var s = v2.stringValue();
ret = false;
for (var i = 0; i < n.length; ++i) {
var nn = xmlValue(n[i]);
if (cmp(nn, s)) {
ret = true;
break;
}
}
} else {
ret = cmp(v1.booleanValue(), v2.booleanValue());
}
} else if (v1.type == 'boolean' || v2.type == 'boolean') {
ret = cmp(v1.booleanValue(), v2.booleanValue());
} else if (v1.type == 'number' || v2.type == 'number') {
ret = cmp(v1.numberValue(), v2.numberValue());
} else {
ret = cmp(v1.stringValue(), v2.stringValue());
}
return new BooleanValue(ret);
};
function LiteralExpr(value) {
this.value = value;
}
LiteralExpr.prototype.evaluate = function(ctx) {
return new StringValue(this.value);
};
function NumberExpr(value) {
this.value = value;
}
NumberExpr.prototype.evaluate = function(ctx) {
return new NumberValue(this.value);
};
function VariableExpr(name) {
this.name = name;
}
VariableExpr.prototype.evaluate = function(ctx) {
return ctx.getVariable(this.name);
};
// Factory functions for semantic values (i.e. Expressions) of the
// productions in the grammar. When a production is matched to reduce
// the current parse state stack, the function is called with the
// semantic values of the matched elements as arguments, and returns
// another semantic value. The semantic value is a node of the parse
// tree, an expression object with an evaluate() method that evaluates the
// expression in an actual context. These factory functions are used
// in the specification of the grammar rules, below.
function makeTokenExpr(m) {
return new TokenExpr(m);
}
function passExpr(e) {
return e;
}
function makeLocationExpr1(slash, rel) {
rel.absolute = true;
return rel;
}
function makeLocationExpr2(dslash, rel) {
rel.absolute = true;
rel.prependStep(makeAbbrevStep(dslash.value));
return rel;
}
function makeLocationExpr3(slash) {
var ret = new LocationExpr();
ret.appendStep(makeAbbrevStep('.'));
ret.absolute = true;
return ret;
}
function makeLocationExpr4(dslash) {
var ret = new LocationExpr();
ret.absolute = true;
ret.appendStep(makeAbbrevStep(dslash.value));
return ret;
}
function makeLocationExpr5(step) {
var ret = new LocationExpr();
ret.appendStep(step);
return ret;
}
function makeLocationExpr6(rel, slash, step) {
rel.appendStep(step);
return rel;
}
function makeLocationExpr7(rel, dslash, step) {
rel.appendStep(makeAbbrevStep(dslash.value));
return rel;
}
function makeStepExpr1(dot) {
return makeAbbrevStep(dot.value);
}
function makeStepExpr2(ddot) {
return makeAbbrevStep(ddot.value);
}
function makeStepExpr3(axisname, axis, nodetest) {
return new StepExpr(axisname.value, nodetest);
}
function makeStepExpr4(at, nodetest) {
return new StepExpr('attribute', nodetest);
}
function makeStepExpr5(nodetest) {
return new StepExpr('child', nodetest);
}
function makeStepExpr6(step, predicate) {
step.appendPredicate(predicate);
return step;
}
function makeAbbrevStep(abbrev) {
switch (abbrev) {
case '//':
return new StepExpr('descendant-or-self', new NodeTestAny);
case '.':
return new StepExpr('self', new NodeTestAny);
case '..':
return new StepExpr('parent', new NodeTestAny);
}
}
function makeNodeTestExpr1(asterisk) {
return new NodeTestElementOrAttribute;
}
function makeNodeTestExpr2(ncname, colon, asterisk) {
return new NodeTestNC(ncname.value);
}
function makeNodeTestExpr3(qname) {
return new NodeTestName(qname.value);
}
function makeNodeTestExpr4(typeo, parenc) {
var type = typeo.value.replace(/\s*\($/, '');
switch(type) {
case 'node':
return new NodeTestAny;
case 'text':
return new NodeTestText;
case 'comment':
return new NodeTestComment;
case 'processing-instruction':
return new NodeTestPI('');
}
}
function makeNodeTestExpr5(typeo, target, parenc) {
var type = typeo.replace(/\s*\($/, '');
if (type != 'processing-instruction') {
throw type;
}
return new NodeTestPI(target.value);
}
function makePredicateExpr(pareno, expr, parenc) {
return new PredicateExpr(expr);
}
function makePrimaryExpr(pareno, expr, parenc) {
return expr;
}
function makeFunctionCallExpr1(name, pareno, parenc) {
return new FunctionCallExpr(name);
}
function makeFunctionCallExpr2(name, pareno, arg1, args, parenc) {
var ret = new FunctionCallExpr(name);
ret.appendArg(arg1);
for (var i = 0; i < args.length; ++i) {
ret.appendArg(args[i]);
}
return ret;
}
function makeArgumentExpr(comma, expr) {
return expr;
}
function makeUnionExpr(expr1, pipe, expr2) {
return new UnionExpr(expr1, expr2);
}
function makePathExpr1(filter, slash, rel) {
return new PathExpr(filter, rel);
}
function makePathExpr2(filter, dslash, rel) {
rel.prependStep(makeAbbrevStep(dslash.value));
return new PathExpr(filter, rel);
}
function makeFilterExpr(expr, predicates) {
if (predicates.length > 0) {
return new FilterExpr(expr, predicates);
} else {
return expr;
}
}
function makeUnaryMinusExpr(minus, expr) {
return new UnaryMinusExpr(expr);
}
function makeBinaryExpr(expr1, op, expr2) {
return new BinaryExpr(expr1, op, expr2);
}
function makeLiteralExpr(token) {
// remove quotes from the parsed value:
var value = token.value.substring(1, token.value.length - 1);
return new LiteralExpr(value);
}
function makeNumberExpr(token) {
return new NumberExpr(token.value);
}
function makeVariableReference(dollar, name) {
return new VariableExpr(name.value);
}
// Used before parsing for optimization of common simple cases. See
// the begin of xpathParse() for which they are.
function makeSimpleExpr(expr) {
if (expr.charAt(0) == '$') {
return new VariableExpr(expr.substr(1));
} else if (expr.charAt(0) == '@') {
var a = new NodeTestName(expr.substr(1));
var b = new StepExpr('attribute', a);
var c = new LocationExpr();
c.appendStep(b);
return c;
} else if (expr.match(/^[0-9]+$/)) {
return new NumberExpr(expr);
} else {
var a = new NodeTestName(expr);
var b = new StepExpr('child', a);
var c = new LocationExpr();
c.appendStep(b);
return c;
}
}
function makeSimpleExpr2(expr) {
var steps = stringSplit(expr, '/');
var c = new LocationExpr();
for (var i = 0; i < steps.length; ++i) {
var a = new NodeTestName(steps[i]);
var b = new StepExpr('child', a);
c.appendStep(b);
}
return c;
}
// The axes of XPath expressions.
var xpathAxis = {
ANCESTOR_OR_SELF: 'ancestor-or-self',
ANCESTOR: 'ancestor',
ATTRIBUTE: 'attribute',
CHILD: 'child',
DESCENDANT_OR_SELF: 'descendant-or-self',
DESCENDANT: 'descendant',
FOLLOWING_SIBLING: 'following-sibling',
FOLLOWING: 'following',
NAMESPACE: 'namespace',
PARENT: 'parent',
PRECEDING_SIBLING: 'preceding-sibling',
PRECEDING: 'preceding',
SELF: 'self'
};
var xpathAxesRe = [
xpathAxis.ANCESTOR_OR_SELF,
xpathAxis.ANCESTOR,
xpathAxis.ATTRIBUTE,
xpathAxis.CHILD,
xpathAxis.DESCENDANT_OR_SELF,
xpathAxis.DESCENDANT,
xpathAxis.FOLLOWING_SIBLING,
xpathAxis.FOLLOWING,
xpathAxis.NAMESPACE,
xpathAxis.PARENT,
xpathAxis.PRECEDING_SIBLING,
xpathAxis.PRECEDING,
xpathAxis.SELF
].join('|');
// The tokens of the language. The label property is just used for
// generating debug output. The prec property is the precedence used
// for shift/reduce resolution. Default precedence is 0 as a lookahead
// token and 2 on the stack. TODO(mesch): this is certainly not
// necessary and too complicated. Simplify this!
// NOTE: tabular formatting is the big exception, but here it should
// be OK.
var TOK_PIPE = { label: "|", prec: 17, re: new RegExp("^\\|") };
var TOK_DSLASH = { label: "//", prec: 19, re: new RegExp("^//") };
var TOK_SLASH = { label: "/", prec: 30, re: new RegExp("^/") };
var TOK_AXIS = { label: "::", prec: 20, re: new RegExp("^::") };
var TOK_COLON = { label: ":", prec: 1000, re: new RegExp("^:") };
var TOK_AXISNAME = { label: "[axis]", re: new RegExp('^(' + xpathAxesRe + ')') };
var TOK_PARENO = { label: "(", prec: 34, re: new RegExp("^\\(") };
var TOK_PARENC = { label: ")", re: new RegExp("^\\)") };
var TOK_DDOT = { label: "..", prec: 34, re: new RegExp("^\\.\\.") };
var TOK_DOT = { label: ".", prec: 34, re: new RegExp("^\\.") };
var TOK_AT = { label: "@", prec: 34, re: new RegExp("^@") };
var TOK_COMMA = { label: ",", re: new RegExp("^,") };
var TOK_OR = { label: "or", prec: 10, re: new RegExp("^or\\b") };
var TOK_AND = { label: "and", prec: 11, re: new RegExp("^and\\b") };
var TOK_EQ = { label: "=", prec: 12, re: new RegExp("^=") };
var TOK_NEQ = { label: "!=", prec: 12, re: new RegExp("^!=") };
var TOK_GE = { label: ">=", prec: 13, re: new RegExp("^>=") };
var TOK_GT = { label: ">", prec: 13, re: new RegExp("^>") };
var TOK_LE = { label: "<=", prec: 13, re: new RegExp("^<=") };
var TOK_LT = { label: "<", prec: 13, re: new RegExp("^<") };
var TOK_PLUS = { label: "+", prec: 14, re: new RegExp("^\\+"), left: true };
var TOK_MINUS = { label: "-", prec: 14, re: new RegExp("^\\-"), left: true };
var TOK_DIV = { label: "div", prec: 15, re: new RegExp("^div\\b"), left: true };
var TOK_MOD = { label: "mod", prec: 15, re: new RegExp("^mod\\b"), left: true };
var TOK_BRACKO = { label: "[", prec: 32, re: new RegExp("^\\[") };
var TOK_BRACKC = { label: "]", re: new RegExp("^\\]") };
var TOK_DOLLAR = { label: "$", re: new RegExp("^\\$") };
var TOK_NCNAME = { label: "[ncname]", re: new RegExp('^' + XML_NC_NAME) };
var TOK_ASTERISK = { label: "*", prec: 15, re: new RegExp("^\\*"), left: true };
var TOK_LITERALQ = { label: "[litq]", prec: 20, re: new RegExp("^'[^\\']*'") };
var TOK_LITERALQQ = {
label: "[litqq]",
prec: 20,
re: new RegExp('^"[^\\"]*"')
};
var TOK_NUMBER = {
label: "[number]",
prec: 35,
re: new RegExp('^\\d+(\\.\\d*)?') };
var TOK_QNAME = {
label: "[qname]",
re: new RegExp('^(' + XML_NC_NAME + ':)?' + XML_NC_NAME)
};
var TOK_NODEO = {
label: "[nodetest-start]",
re: new RegExp('^(processing-instruction|comment|text|node)\\(')
};
// The table of the tokens of our grammar, used by the lexer: first
// column the tag, second column a regexp to recognize it in the
// input, third column the precedence of the token, fourth column a
// factory function for the semantic value of the token.
//
// NOTE: order of this list is important, because the first match
// counts. Cf. DDOT and DOT, and AXIS and COLON.
var xpathTokenRules = [
TOK_DSLASH,
TOK_SLASH,
TOK_DDOT,
TOK_DOT,
TOK_AXIS,
TOK_COLON,
TOK_AXISNAME,
TOK_NODEO,
TOK_PARENO,
TOK_PARENC,
TOK_BRACKO,
TOK_BRACKC,
TOK_AT,
TOK_COMMA,
TOK_OR,
TOK_AND,
TOK_NEQ,
TOK_EQ,
TOK_GE,
TOK_GT,
TOK_LE,
TOK_LT,
TOK_PLUS,
TOK_MINUS,
TOK_ASTERISK,
TOK_PIPE,
TOK_MOD,
TOK_DIV,
TOK_LITERALQ,
TOK_LITERALQQ,
TOK_NUMBER,
TOK_QNAME,
TOK_NCNAME,
TOK_DOLLAR
];
// All the nonterminals of the grammar. The nonterminal objects are
// identified by object identity; the labels are used in the debug
// output only.
var XPathLocationPath = { label: "LocationPath" };
var XPathRelativeLocationPath = { label: "RelativeLocationPath" };
var XPathAbsoluteLocationPath = { label: "AbsoluteLocationPath" };
var XPathStep = { label: "Step" };
var XPathNodeTest = { label: "NodeTest" };
var XPathPredicate = { label: "Predicate" };
var XPathLiteral = { label: "Literal" };
var XPathExpr = { label: "Expr" };
var XPathPrimaryExpr = { label: "PrimaryExpr" };
var XPathVariableReference = { label: "Variablereference" };
var XPathNumber = { label: "Number" };
var XPathFunctionCall = { label: "FunctionCall" };
var XPathArgumentRemainder = { label: "ArgumentRemainder" };
var XPathPathExpr = { label: "PathExpr" };
var XPathUnionExpr = { label: "UnionExpr" };
var XPathFilterExpr = { label: "FilterExpr" };
var XPathDigits = { label: "Digits" };
var xpathNonTerminals = [
XPathLocationPath,
XPathRelativeLocationPath,
XPathAbsoluteLocationPath,
XPathStep,
XPathNodeTest,
XPathPredicate,
XPathLiteral,
XPathExpr,
XPathPrimaryExpr,
XPathVariableReference,
XPathNumber,
XPathFunctionCall,
XPathArgumentRemainder,
XPathPathExpr,
XPathUnionExpr,
XPathFilterExpr,
XPathDigits
];
// Quantifiers that are used in the productions of the grammar.
var Q_01 = { label: "?" };
var Q_MM = { label: "*" };
var Q_1M = { label: "+" };
// Tag for left associativity (right assoc is implied by undefined).
var ASSOC_LEFT = true;
// The productions of the grammar. Columns of the table:
//
// - target nonterminal,
// - pattern,
// - precedence,
// - semantic value factory
//
// The semantic value factory is a function that receives parse tree
// nodes from the stack frames of the matched symbols as arguments and
// returns an a node of the parse tree. The node is stored in the top
// stack frame along with the target object of the rule. The node in
// the parse tree is an expression object that has an evaluate() method
// and thus evaluates XPath expressions.
//
// The precedence is used to decide between reducing and shifting by
// comparing the precendence of the rule that is candidate for
// reducing with the precedence of the look ahead token. Precedence of
// -1 means that the precedence of the tokens in the pattern is used
// instead. TODO: It shouldn't be necessary to explicitly assign
// precedences to rules.
var xpathGrammarRules =
[
[ XPathLocationPath, [ XPathRelativeLocationPath ], 18,
passExpr ],
[ XPathLocationPath, [ XPathAbsoluteLocationPath ], 18,
passExpr ],
[ XPathAbsoluteLocationPath, [ TOK_SLASH, XPathRelativeLocationPath ], 18,
makeLocationExpr1 ],
[ XPathAbsoluteLocationPath, [ TOK_DSLASH, XPathRelativeLocationPath ], 18,
makeLocationExpr2 ],
[ XPathAbsoluteLocationPath, [ TOK_SLASH ], 0,
makeLocationExpr3 ],
[ XPathAbsoluteLocationPath, [ TOK_DSLASH ], 0,
makeLocationExpr4 ],
[ XPathRelativeLocationPath, [ XPathStep ], 31,
makeLocationExpr5 ],
[ XPathRelativeLocationPath,
[ XPathRelativeLocationPath, TOK_SLASH, XPathStep ], 31,
makeLocationExpr6 ],
[ XPathRelativeLocationPath,
[ XPathRelativeLocationPath, TOK_DSLASH, XPathStep ], 31,
makeLocationExpr7 ],
[ XPathStep, [ TOK_DOT ], 33,
makeStepExpr1 ],
[ XPathStep, [ TOK_DDOT ], 33,
makeStepExpr2 ],
[ XPathStep,
[ TOK_AXISNAME, TOK_AXIS, XPathNodeTest ], 33,
makeStepExpr3 ],
[ XPathStep, [ TOK_AT, XPathNodeTest ], 33,
makeStepExpr4 ],
[ XPathStep, [ XPathNodeTest ], 33,
makeStepExpr5 ],
[ XPathStep, [ XPathStep, XPathPredicate ], 33,
makeStepExpr6 ],
[ XPathNodeTest, [ TOK_ASTERISK ], 33,
makeNodeTestExpr1 ],
[ XPathNodeTest, [ TOK_NCNAME, TOK_COLON, TOK_ASTERISK ], 33,
makeNodeTestExpr2 ],
[ XPathNodeTest, [ TOK_QNAME ], 33,
makeNodeTestExpr3 ],
[ XPathNodeTest, [ TOK_NODEO, TOK_PARENC ], 33,
makeNodeTestExpr4 ],
[ XPathNodeTest, [ TOK_NODEO, XPathLiteral, TOK_PARENC ], 33,
makeNodeTestExpr5 ],
[ XPathPredicate, [ TOK_BRACKO, XPathExpr, TOK_BRACKC ], 33,
makePredicateExpr ],
[ XPathPrimaryExpr, [ XPathVariableReference ], 33,
passExpr ],
[ XPathPrimaryExpr, [ TOK_PARENO, XPathExpr, TOK_PARENC ], 33,
makePrimaryExpr ],
[ XPathPrimaryExpr, [ XPathLiteral ], 30,
passExpr ],
[ XPathPrimaryExpr, [ XPathNumber ], 30,
passExpr ],
[ XPathPrimaryExpr, [ XPathFunctionCall ], 30,
passExpr ],
[ XPathFunctionCall, [ TOK_QNAME, TOK_PARENO, TOK_PARENC ], -1,
makeFunctionCallExpr1 ],
[ XPathFunctionCall,
[ TOK_QNAME, TOK_PARENO, XPathExpr, XPathArgumentRemainder, Q_MM,
TOK_PARENC ], -1,
makeFunctionCallExpr2 ],
[ XPathArgumentRemainder, [ TOK_COMMA, XPathExpr ], -1,
makeArgumentExpr ],
[ XPathUnionExpr, [ XPathPathExpr ], 20,
passExpr ],
[ XPathUnionExpr, [ XPathUnionExpr, TOK_PIPE, XPathPathExpr ], 20,
makeUnionExpr ],
[ XPathPathExpr, [ XPathLocationPath ], 20,
passExpr ],
[ XPathPathExpr, [ XPathFilterExpr ], 19,
passExpr ],
[ XPathPathExpr,
[ XPathFilterExpr, TOK_SLASH, XPathRelativeLocationPath ], 20,
makePathExpr1 ],
[ XPathPathExpr,
[ XPathFilterExpr, TOK_DSLASH, XPathRelativeLocationPath ], 20,
makePathExpr2 ],
[ XPathFilterExpr, [ XPathPrimaryExpr, XPathPredicate, Q_MM ], 20,
makeFilterExpr ],
[ XPathExpr, [ XPathPrimaryExpr ], 16,
passExpr ],
[ XPathExpr, [ XPathUnionExpr ], 16,
passExpr ],
[ XPathExpr, [ TOK_MINUS, XPathExpr ], -1,
makeUnaryMinusExpr ],
[ XPathExpr, [ XPathExpr, TOK_OR, XPathExpr ], -1,
makeBinaryExpr ],
[ XPathExpr, [ XPathExpr, TOK_AND, XPathExpr ], -1,
makeBinaryExpr ],
[ XPathExpr, [ XPathExpr, TOK_EQ, XPathExpr ], -1,
makeBinaryExpr ],
[ XPathExpr, [ XPathExpr, TOK_NEQ, XPathExpr ], -1,
makeBinaryExpr ],
[ XPathExpr, [ XPathExpr, TOK_LT, XPathExpr ], -1,
makeBinaryExpr ],
[ XPathExpr, [ XPathExpr, TOK_LE, XPathExpr ], -1,
makeBinaryExpr ],
[ XPathExpr, [ XPathExpr, TOK_GT, XPathExpr ], -1,
makeBinaryExpr ],
[ XPathExpr, [ XPathExpr, TOK_GE, XPathExpr ], -1,
makeBinaryExpr ],
[ XPathExpr, [ XPathExpr, TOK_PLUS, XPathExpr ], -1,
makeBinaryExpr, ASSOC_LEFT ],
[ XPathExpr, [ XPathExpr, TOK_MINUS, XPathExpr ], -1,
makeBinaryExpr, ASSOC_LEFT ],
[ XPathExpr, [ XPathExpr, TOK_ASTERISK, XPathExpr ], -1,
makeBinaryExpr, ASSOC_LEFT ],
[ XPathExpr, [ XPathExpr, TOK_DIV, XPathExpr ], -1,
makeBinaryExpr, ASSOC_LEFT ],
[ XPathExpr, [ XPathExpr, TOK_MOD, XPathExpr ], -1,
makeBinaryExpr, ASSOC_LEFT ],
[ XPathLiteral, [ TOK_LITERALQ ], -1,
makeLiteralExpr ],
[ XPathLiteral, [ TOK_LITERALQQ ], -1,
makeLiteralExpr ],
[ XPathNumber, [ TOK_NUMBER ], -1,
makeNumberExpr ],
[ XPathVariableReference, [ TOK_DOLLAR, TOK_QNAME ], 200,
makeVariableReference ]
];
// That function computes some optimizations of the above data
// structures and will be called right here. It merely takes the
// counter variables out of the global scope.
var xpathRules = [];
function xpathParseInit() {
if (xpathRules.length) {
return;
}
// Some simple optimizations for the xpath expression parser: sort
// grammar rules descending by length, so that the longest match is
// first found.
xpathGrammarRules.sort(function(a,b) {
var la = a[1].length;
var lb = b[1].length;
if (la < lb) {
return 1;
} else if (la > lb) {
return -1;
} else {
return 0;
}
});
var k = 1;
for (var i = 0; i < xpathNonTerminals.length; ++i) {
xpathNonTerminals[i].key = k++;
}
for (i = 0; i < xpathTokenRules.length; ++i) {
xpathTokenRules[i].key = k++;
}
xpathLog('XPath parse INIT: ' + k + ' rules');
// Another slight optimization: sort the rules into bins according
// to the last element (observing quantifiers), so we can restrict
// the match against the stack to the subest of rules that match the
// top of the stack.
//
// TODO(mesch): What we actually want is to compute states as in
// bison, so that we don't have to do any explicit and iterated
// match against the stack.
function push_(array, position, element) {
if (!array[position]) {
array[position] = [];
}
array[position].push(element);
}
for (i = 0; i < xpathGrammarRules.length; ++i) {
var rule = xpathGrammarRules[i];
var pattern = rule[1];
for (var j = pattern.length - 1; j >= 0; --j) {
if (pattern[j] == Q_1M) {
push_(xpathRules, pattern[j-1].key, rule);
break;
} else if (pattern[j] == Q_MM || pattern[j] == Q_01) {
push_(xpathRules, pattern[j-1].key, rule);
--j;
} else {
push_(xpathRules, pattern[j].key, rule);
break;
}
}
}
xpathLog('XPath parse INIT: ' + xpathRules.length + ' rule bins');
var sum = 0;
mapExec(xpathRules, function(i) {
if (i) {
sum += i.length;
}
});
xpathLog('XPath parse INIT: ' + (sum / xpathRules.length) +
' average bin size');
}
// Local utility functions that are used by the lexer or parser.
function xpathCollectDescendants(nodelist, node) {
for (var n = node.firstChild; n; n = n.nextSibling) {
nodelist.push(n);
arguments.callee(nodelist, n);
}
}
function xpathCollectDescendantsReverse(nodelist, node) {
for (var n = node.lastChild; n; n = n.previousSibling) {
nodelist.push(n);
arguments.callee(nodelist, n);
}
}
// The entry point for the library: match an expression against a DOM
// node. Returns an XPath value.
function xpathDomEval(expr, node) {
var expr1 = xpathParse(expr);
var ret = expr1.evaluate(new ExprContext(node));
return ret;
}
// Utility function to sort a list of nodes. Used by xsltSort() and
// nxslSelect().
function xpathSort(input, sort) {
if (sort.length == 0) {
return;
}
var sortlist = [];
for (var i = 0; i < input.contextSize(); ++i) {
var node = input.nodelist[i];
var sortitem = { node: node, key: [] };
var context = input.clone(node, 0, [ node ]);
for (var j = 0; j < sort.length; ++j) {
var s = sort[j];
var value = s.expr.evaluate(context);
var evalue;
if (s.type == 'text') {
evalue = value.stringValue();
} else if (s.type == 'number') {
evalue = value.numberValue();
}
sortitem.key.push({ value: evalue, order: s.order });
}
// Make the sort stable by adding a lowest priority sort by
// id. This is very convenient and furthermore required by the
// spec ([XSLT] - Section 10 Sorting).
sortitem.key.push({ value: i, order: 'ascending' });
sortlist.push(sortitem);
}
sortlist.sort(xpathSortByKey);
var nodes = [];
for (var i = 0; i < sortlist.length; ++i) {
nodes.push(sortlist[i].node);
}
input.nodelist = nodes;
input.setNode(0);
}
// Sorts by all order criteria defined. According to the JavaScript
// spec ([ECMA] Section 11.8.5), the compare operators compare strings
// as strings and numbers as numbers.
//
// NOTE: In browsers which do not follow the spec, this breaks only in
// the case that numbers should be sorted as strings, which is very
// uncommon.
function xpathSortByKey(v1, v2) {
// NOTE: Sort key vectors of different length never occur in
// xsltSort.
for (var i = 0; i < v1.key.length; ++i) {
var o = v1.key[i].order == 'descending' ? -1 : 1;
if (v1.key[i].value > v2.key[i].value) {
return +1 * o;
} else if (v1.key[i].value < v2.key[i].value) {
return -1 * o;
}
}
return 0;
}
// Parses and then evaluates the given XPath expression in the given
// input context. Notice that parsed xpath expressions are cached.
function xpathEval(select, context) {
var expr = xpathParse(select);
var ret = expr.evaluate(context);
return ret;
}