Move pathTo function outside astar.search

This small optimization avoid to redefine the pathTo function in memory
each time astar.search() is called.

Author: TiTi

astar.js

@@ -17,6 +17,16 @@
     }
 })(function() {
 
+function pathTo(node){
+    var curr = node,
+        path = [];
+    while(curr.parent) {
+        path.push(curr);
+        curr = curr.parent;
+    }
+    return path.reverse();
+}
+
 var astar = {
     init: function(graph) {
         for (var i = 0, len = graph.nodes.length; i < len; ++i) {
@@ -56,17 +66,6 @@ var astar = {
 
         start.h = heuristic(start, end);
 
-        function pathTo(node){
-            var curr = node;
-            var path = [];
-            while(curr.parent) {
-                path.push(curr);
-                curr = curr.parent;
-            }
-            return path.reverse();
-        }
-
-
         openHeap.push(start);
 
         while(openHeap.size() > 0) {