+var Selector = Class.create();
+Selector.prototype = {
+ initialize: function(expression) {
+ this.params = {classNames: []};
+ this.expression = expression.toString().strip();
+ this.parseExpression();
+ this.compileMatcher();
+ },
+
+ parseExpression: function() {
+ function abort(message) { throw 'Parse error in selector: ' + message; }
+
+ if (this.expression == '') abort('empty expression');
+
+ var params = this.params, expr = this.expression, match, modifier, clause, rest;
+ while (match = expr.match(/^(.*)\[([a-z0-9_:-]+?)(?:([~\|!]?=)(?:"([^"]*)"|([^\]\s]*)))?\]$/i)) {
+ params.attributes = params.attributes || [];
+ params.attributes.push({name: match[2], operator: match[3], value: match[4] || match[5] || ''});
+ expr = match[1];
+ }
+
+ if (expr == '*') return this.params.wildcard = true;
+
+ while (match = expr.match(/^([^a-z0-9_-])?([a-z0-9_-]+)(.*)/i)) {
+ modifier = match[1], clause = match[2], rest = match[3];
+ switch (modifier) {
+ case '#': params.id = clause; break;
+ case '.': params.classNames.push(clause); break;
+ case '':
+ case undefined: params.tagName = clause.toUpperCase(); break;
+ default: abort(expr.inspect());
+ }
+ expr = rest;
+ }
+
+ if (expr.length > 0) abort(expr.inspect());
+ },
+
+ buildMatchExpression: function() {
+ var params = this.params, conditions = [], clause;
+
+ if (params.wildcard)
+ conditions.push('true');
+ if (clause = params.id)
+ conditions.push('element.id == ' + clause.inspect());
+ if (clause = params.tagName)
+ conditions.push('element.tagName.toUpperCase() == ' + clause.inspect());
+ if ((clause = params.classNames).length > 0)
+ for (var i = 0; i < clause.length; i++)
+ conditions.push('Element.hasClassName(element, ' + clause[i].inspect() + ')');
+ if (clause = params.attributes) {
+ clause.each(function(attribute) {
+ var value = 'element.getAttribute(' + attribute.name.inspect() + ')';
+ var splitValueBy = function(delimiter) {
+ return value + ' && ' + value + '.split(' + delimiter.inspect() + ')';
+ }
+
+ switch (attribute.operator) {
+ case '=': conditions.push(value + ' == ' + attribute.value.inspect()); break;
+ case '~=': conditions.push(splitValueBy(' ') + '.include(' + attribute.value.inspect() + ')'); break;
+ case '|=': conditions.push(
+ splitValueBy('-') + '.first().toUpperCase() == ' + attribute.value.toUpperCase().inspect()
+ ); break;
+ case '!=': conditions.push(value + ' != ' + attribute.value.inspect()); break;
+ case '':
+ case undefined: conditions.push(value + ' != null'); break;
+ default: throw 'Unknown operator ' + attribute.operator + ' in selector';
+ }
+ });
+ }
+
+ return conditions.join(' && ');
+ },
+
+ compileMatcher: function() {
+ this.match = new Function('element', 'if (!element.tagName) return false; \
+ return ' + this.buildMatchExpression());
+ },
+
+ findElements: function(scope) {
+ var element;
+
+ if (element = $(this.params.id))
+ if (this.match(element))
+ if (!scope || Element.childOf(element, scope))
+ return [element];
+
+ scope = (scope || document).getElementsByTagName(this.params.tagName || '*');
+
+ var results = [];
+ for (var i = 0; i < scope.length; i++)
+ if (this.match(element = scope[i]))
+ results.push(Element.extend(element));
+
+ return results;
+ },
+
+ toString: function() {
+ return this.expression;
+ }
+}
+
+function $$() {
+ return $A(arguments).map(function(expression) {
+ return expression.strip().split(/\s+/).inject([null], function(results, expr) {
+ var selector = new Selector(expr);
+ return results.map(selector.findElements.bind(selector)).flatten();
+ });
+ }).flatten();
+}