jquery/src/selector-native.js

var selector_hasDuplicate,
	matches = docElem.matchesSelector ||
		docElem.mozMatchesSelector ||
		docElem.webkitMatchesSelector ||
		docElem.oMatchesSelector ||
		docElem.msMatchesSelector,
	selector_sortOrder = function( a, b ) {
		// Flag for duplicate removal
		if ( a === b ) {
			selector_hasDuplicate = true;
			return 0;
		}

		var compare = b.compareDocumentPosition && a.compareDocumentPosition && a.compareDocumentPosition( b );

		if ( compare ) {
			// Disconnected nodes
			if ( compare & 1 ) {

				// Choose the first element that is related to our document
				if ( a === document || jQuery.contains(document, a) ) {
					return -1;
				}
				if ( b === document || jQuery.contains(document, b) ) {
					return 1;
				}

				// Maintain original order
				return 0;
			}

			return compare & 4 ? -1 : 1;
		}

		// Not directly comparable, sort on existence of method
		return a.compareDocumentPosition ? -1 : 1;
	};

jQuery.extend({
	find: function( selector, context, results, seed ) {
		var elem,
			i = 0;

		results = results || [];
		context = context || document;

		if ( seed ) {
			while ( (elem = seed[i++]) ) {
				if ( jQuery.find.matchesSelector(elem, selector) ) {
					results.push( elem );
				}
			}
		} else {
			jQuery.merge( results, context.querySelectorAll(selector) );
		}

		return results;
	},
	unique: function( results ) {
		var elem,
			duplicates = [],
			i = 0,
			j = 0;

		selector_hasDuplicate = false;
		results.sort( selector_sortOrder );

		if ( selector_hasDuplicate ) {
			while ( (elem = results[i++]) ) {
				if ( elem === results[ i ] ) {
					j = duplicates.push( i );
				}
			}
			while ( j-- ) {
				results.splice( duplicates[ j ], 1 );
			}
		}

		return results;
	},
	text: function( elem ) {
		var node,
			ret = "",
			i = 0,
			nodeType = elem.nodeType;

		if ( !nodeType ) {
			// If no nodeType, this is expected to be an array
			while ( (node = elem[i++]) ) {
				// Do not traverse comment nodes
				ret += jQuery.text( node );
			}
		} else if ( nodeType === 1 || nodeType === 9 || nodeType === 11 ) {
			// Use textContent for elements
			return elem.textContent;
		} else if ( nodeType === 3 || nodeType === 4 ) {
			return elem.nodeValue;
		}
		// Do not include comment or processing instruction nodes

		return ret;
	},
	contains: function( a, b ) {
		var adown = a.nodeType === 9 ? a.documentElement : a,
			bup = b && b.parentNode;
		return a === bup || !!( bup && bup.nodeType === 1 && adown.contains(bup) );
	},
	isXMLDoc: function( elem ) {
		return (elem.ownerDocument || elem).documentElement.nodeName !== "HTML";
	},
	expr: {
		match: {
			needsContext: /^[\x20\t\r\n\f]*[>+~]/
		}
	}
});

jQuery.extend( jQuery.find, {
	matches: function( expr, elements ) {
		return jQuery.find( expr, null, null, elements );
	},
	matchesSelector: function( elem, expr ) {
		return matches.call( elem, expr );
	}
});