Merge pull request #128 from chichina/master

performance nit

lib/src/tree.dart

@@ -123,14 +123,14 @@ class RouteTree {
       Map<RouteTreeNode, RouteTreeNodeMatch> currentMatches =
           <RouteTreeNode, RouteTreeNodeMatch>{};
       List<RouteTreeNode> nextNodes = <RouteTreeNode>[];
+      String pathPart = checkComponent;
+      Map<String, List<String>> queryMap;
+      if (checkComponent.contains("?")) {
+        var splitParam = checkComponent.split("?");
+        pathPart = splitParam[0];
+        queryMap = parseQueryString(splitParam[1]);
+      }
       for (RouteTreeNode node in nodesToCheck) {
-        String pathPart = checkComponent;
-        Map<String, List<String>> queryMap;
-        if (checkComponent.contains("?")) {
-          var splitParam = checkComponent.split("?");
-          pathPart = splitParam[0];
-          queryMap = parseQueryString(splitParam[1]);
-        }
         bool isMatch = (node.part == pathPart || node.isParameter());
         if (isMatch) {
           RouteTreeNodeMatch parentMatch = nodeMatches[node.parent];