Refactoring regular expression.

Author: zaqqaz

dist/ui-scroll.js

@@ -567,7 +567,7 @@ angular.module('ui.scroll', []).directive('uiScrollViewport', function () {
 
   function link($scope, element, $attr, controllers, linker) {
 
-    var match = $attr.uiScroll.match(/^\s*(\w+)\s+in\s+([(\w|\$)\.]+)\s*$/);
+    var match = $attr.uiScroll.match(/^\s*(\w+)\s+in\s+([\$\w\.]+)\s*$/);
 
     if (!match) throw new Error('Expected uiScroll in form of \'_item_ in _datasource_\' but got \'' + $attr.uiScroll + '\'');