refactor(collection): use Map instead of Object

modules/di/src/injector.js

@@ -45,7 +45,7 @@ export class Injector {
 
   _createListOfBindings(flattenBindings):List {
     var bindings = ListWrapper.createFixedSize(Key.numberOfKeys() + 1);
-    MapWrapper.forEach(flattenBindings, (keyId, v) => bindings[keyId] = v);
+    MapWrapper.forEach(flattenBindings, (v, keyId) => bindings[keyId] = v);
     return bindings;
   }
 

modules/di/src/key.js

@@ -1,7 +1,7 @@
-import {MapWrapper} from 'facade/collection';
+import {MapWrapper, Map} from 'facade/collection';
 import {FIELD, int, isPresent} from 'facade/lang';
 
-var _allKeys = {};
+var _allKeys = MapWrapper.create();
 var _id:int = 0;
 
 export class Key {
@@ -15,8 +15,9 @@ export class Key {
   static get(token) {
     if (token instanceof Key) return token;
 
-    var obj = MapWrapper.get(_allKeys, token);
-    if (isPresent(obj)) return obj;
+    if (MapWrapper.contains(_allKeys, token)) {
+      return MapWrapper.get(_allKeys, token);
+    }
 
     var newKey = new Key(token, ++_id);
     MapWrapper.set(_allKeys, token, newKey);

modules/facade/src/collection.dart

@@ -9,7 +9,7 @@ class MapWrapper {
   static void set(m, k, v){ m[k] = v; }
   static contains(m, k) => m.containsKey(k);
   static forEach(m, fn) {
-    m.forEach(fn);
+    m.forEach((k,v) => fn(v,k));
   }
 }
 

modules/facade/src/collection.es6

@@ -4,13 +4,11 @@ export var Set = window.Set;
 
 export class MapWrapper {
   static create():Map { return new Map(); }
-  static get(m, k) { return m[k]; }
-  static set(m, k, v) { m[k] = v; }
-  static contains(m, k) { return  m[k] != undefined; }
+  static get(m, k) { return m.get(k); }
+  static set(m, k, v) { m.set(k,v); }
+  static contains(m, k) { return  m.has(k); }
   static forEach(m, fn) {
-    for(var k in m) {
-      fn(k, m[k]);
-    }
+    m.forEach(fn);
   }
 }