add docs on iterators

8 files changed, 175 insertions, 40 deletions

diff --git a/js/README.md b/js/README.md
index 8a46f598b..8e2a373da 100644
--- a/js/README.md
+++ b/js/README.md
@@ -9,8 +9,25 @@ then run:
 
 The news app uses [Traceur](https://github.com/google/traceur-compiler) to transpile ES6 into ES5. If you want to take a look at the features see [the language features reference](https://github.com/google/traceur-compiler/wiki/LanguageFeatures#language-features).
 
-* Modules can not be used since the code is inlined
-* The following iterators are available: **items**
+### Iterator
+The following iterators are defined and availabe:
+
+* **items**:
+
+	```js
+	// iterate over object key and value
+	for (let [key, value] of items(obj)) {
+		console.log(`object key: ${key}, object value: ${value}`)
+	}
+	```
+* **enumerate**:
+
+	```js
+	// iterate over object key and value
+	for (let [index, value] of enumerate(list)) {
+		console.log(`at position: ${index}, value is: ${value}`)
+	}
+	```
 
 ## Building
 Watch mode:
diff --git a/js/build/app.js b/js/build/app.js
index 4a3eed819..8f09b44d1 100644
--- a/js/build/app.js
+++ b/js/build/app.js
@@ -206,8 +206,8 @@ var $__build_47_app__ = function () {
           'use strict';
           var FeedResource = function FeedResource($http) {
             $traceurRuntime.superCall(this, $FeedResource.prototype, 'constructor', [
-              'url',
-              $http
+              $http,
+              'url'
             ]);
           };
           var $FeedResource = FeedResource;
@@ -222,8 +222,8 @@ var $__build_47_app__ = function () {
           'use strict';
           var FolderResource = function FolderResource($http) {
             $traceurRuntime.superCall(this, $FolderResource.prototype, 'constructor', [
-              'name',
-              $http
+              $http,
+              'name'
             ]);
           };
           var $FolderResource = FolderResource;
@@ -237,10 +237,7 @@ var $__build_47_app__ = function () {
         function (Resource, $http) {
           'use strict';
           var ItemResource = function ItemResource($http) {
-            $traceurRuntime.superCall(this, $ItemResource.prototype, 'constructor', [
-              'id',
-              $http
-            ]);
+            $traceurRuntime.superCall(this, $ItemResource.prototype, 'constructor', [$http]);
           };
           var $ItemResource = ItemResource;
           $traceurRuntime.createClass(ItemResource, {
@@ -345,18 +342,25 @@ var $__build_47_app__ = function () {
       });
       app.factory('Resource', function () {
         'use strict';
-        var Resource = function Resource(id, http) {
+        var Resource = function Resource(http) {
+          var id = arguments[1] !== void 0 ? arguments[1] : 'id';
           this.id = id;
           this.values = [];
           this.hashMap = {};
           this.http = http;
         };
         $traceurRuntime.createClass(Resource, {
-          receive: function (values) {
-            var $__0 = this;
-            values.forEach(function (value) {
-              $__0.add(value);
-            });
+          receive: function (objs) {
+            for (var $__3 = objs[$traceurRuntime.toProperty(Symbol.iterator)](), $__4; !($__4 = $__3.next()).done;) {
+              try {
+                throw undefined;
+              } catch (obj) {
+                obj = $__4.value;
+                {
+                  this.add(obj);
+                }
+              }
+            }
           },
           add: function (obj) {
             var existing = this.hashMap[$traceurRuntime.toProperty(obj[$traceurRuntime.toProperty(this.id)])];
@@ -396,23 +400,26 @@ var $__build_47_app__ = function () {
           },
           delete: function (id) {
             var deleteAtIndex;
-            {
+            for (var $__3 = enumerate(this.values)[$traceurRuntime.toProperty(Symbol.iterator)](), $__4; !($__4 = $__3.next()).done;) {
               try {
                 throw undefined;
-              } catch ($i) {
-                $i = 0;
-                for (; $i < this.values.length; $i += 1) {
+              } catch (value) {
+                try {
+                  throw undefined;
+                } catch (index) {
                   try {
                     throw undefined;
-                  } catch (i) {
-                    i = $i;
-                    try {
-                      if (this.values[$traceurRuntime.toProperty(i)][$traceurRuntime.toProperty(this.id)] === id) {
-                        deleteAtIndex = i;
+                  } catch ($__8) {
+                    {
+                      $__8 = $traceurRuntime.assertObject($__4.value);
+                      index = $__8[0];
+                      value = $__8[1];
+                    }
+                    {
+                      if (value[$traceurRuntime.toProperty(this.id)] === id) {
+                        deleteAtIndex = index;
                         break;
                       }
-                    } finally {
-                      $i = i;
                     }
                   }
                 }
@@ -685,6 +692,98 @@ var $__build_47_app__ = function () {
           writable: true
         }), $__2;
       };
+      window.enumerate = function (list) {
+        'use strict';
+        var $__2;
+        return $__2 = {}, Object.defineProperty($__2, Symbol.iterator, {
+          value: function () {
+            return $traceurRuntime.initGeneratorFunction(function $__9() {
+              var counter, $counter;
+              return $traceurRuntime.createGeneratorInstance(function ($ctx) {
+                while (true)
+                  switch ($ctx.state) {
+                  case 0:
+                    $ctx.pushTry(28, null);
+                    $ctx.state = 31;
+                    break;
+                  case 31:
+                    throw undefined;
+                    $ctx.state = 33;
+                    break;
+                  case 33:
+                    $ctx.popTry();
+                    $ctx.state = -2;
+                    break;
+                  case 28:
+                    $ctx.popTry();
+                    $counter = $ctx.storedException;
+                    $ctx.state = 26;
+                    break;
+                  case 26:
+                    $counter = 0;
+                    $ctx.state = 27;
+                    break;
+                  case 27:
+                    $ctx.state = $counter < list.length ? 17 : -2;
+                    break;
+                  case 22:
+                    $counter += 1;
+                    $ctx.state = 27;
+                    break;
+                  case 17:
+                    $ctx.pushTry(15, null);
+                    $ctx.state = 18;
+                    break;
+                  case 18:
+                    throw undefined;
+                    $ctx.state = 20;
+                    break;
+                  case 20:
+                    $ctx.popTry();
+                    $ctx.state = 22;
+                    break;
+                  case 15:
+                    $ctx.popTry();
+                    counter = $ctx.storedException;
+                    $ctx.state = 13;
+                    break;
+                  case 13:
+                    counter = $counter;
+                    $ctx.state = 14;
+                    break;
+                  case 14:
+                    $ctx.pushTry(null, 6);
+                    $ctx.state = 8;
+                    break;
+                  case 8:
+                    $ctx.state = 2;
+                    return [
+                      counter,
+                      list[$traceurRuntime.toProperty(counter)]
+                    ];
+                  case 2:
+                    $ctx.maybeThrow();
+                    $ctx.state = 22;
+                    break;
+                  case 6:
+                    $ctx.popTry();
+                    $ctx.state = 12;
+                    break;
+                  case 12:
+                    $counter = counter;
+                    $ctx.state = 10;
+                    break;
+                  default:
+                    return $ctx.end();
+                  }
+              }, $__9, this);
+            })();
+          },
+          configurable: true,
+          enumerable: true,
+          writable: true
+        }), $__2;
+      };
     }(window, document, angular, jQuery, OC, oc_requesttoken));
     return {};
   }();
\ No newline at end of file
diff --git a/js/service/FeedResource.js b/js/service/FeedResource.js
index 903a58241..579396b9d 100644
--- a/js/service/FeedResource.js
+++ b/js/service/FeedResource.js
@@ -12,7 +12,7 @@ app.factory('FeedResource', (Resource, $http) => {
 
     class FeedResource extends Resource {
         constructor ($http) {
-            super('url', $http);
+            super($http, 'url');
         }
     }
 
diff --git a/js/service/FolderResource.js b/js/service/FolderResource.js
index b1c0271dd..314900e37 100644
--- a/js/service/FolderResource.js
+++ b/js/service/FolderResource.js
@@ -12,7 +12,7 @@ app.factory('FolderResource', (Resource, $http) => {
 
     class FolderResource extends Resource {
         constructor ($http) {
-            super('name', $http);
+            super($http, 'name');
         }
     }
 
diff --git a/js/service/ItemResource.js b/js/service/ItemResource.js
index 8cb47d527..5750f2c6b 100644
--- a/js/service/ItemResource.js
+++ b/js/service/ItemResource.js
@@ -13,7 +13,7 @@ app.factory('ItemResource', (Resource, $http) => {
     class ItemResource extends Resource {
 
         constructor ($http) {
-            super('id', $http);
+            super($http);
         }
 
         receive (value, channel) {
diff --git a/js/service/Resource.js b/js/service/Resource.js
index 832b9d791..44a7277b6 100644
--- a/js/service/Resource.js
+++ b/js/service/Resource.js
@@ -12,17 +12,17 @@ app.factory('Resource', () => {
 
     class Resource {
 
-        constructor (id, http) {
+        constructor (http, id='id') {
             this.id = id;
             this.values = [];
             this.hashMap = {};
             this.http = http;
         }
 
-        receive (values) {
-            values.forEach((value) => {
-                this.add(value);
-            });
+        receive (objs) {
+            for (let obj of objs) {
+                this.add(obj);
+            }
         }
 
         add (obj) {
@@ -51,9 +51,9 @@ app.factory('Resource', () => {
             // find index of object that should be deleted
             let deleteAtIndex;
 
-            for (let i = 0; i < this.values.length; i += 1) {
-                if (this.values[i][this.id] === id) {
-                    deleteAtIndex = i;
+            for (let [index, value] of enumerate(this.values)) {
+                if (value[this.id] === id) {
+                    deleteAtIndex = index;
                     break;
                 }
             }
diff --git a/js/tests/unit/service/ResourceSpec.js b/js/tests/unit/service/ResourceSpec.js
index ec0b95ed9..2fead3479 100644
--- a/js/tests/unit/service/ResourceSpec.js
+++ b/js/tests/unit/service/ResourceSpec.js
@@ -17,7 +17,7 @@ describe('Resource', () => {
     beforeEach(inject((Resource, $http) => {
         class ChildResource extends Resource {
             constructor ($http) {
-                super('id', $http);
+                super($http);
             }
         }
 
diff --git a/js/utility/iterators.js b/js/utility/iterators.js
index e40a07110..b83e5de82 100644
--- a/js/utility/iterators.js
+++ b/js/utility/iterators.js
@@ -28,4 +28,23 @@ window.items = function (obj) {
             })();
         }
     };
-}
\ No newline at end of file
+};
+
+/**
+ * Iterates over a list and returns the item and index
+ * like: (let [index, value] of list)
+ * Similar to Pythons enumerate() iterator function
+ */
+window.enumerate = function (list) {
+    'use strict';
+
+    return {
+        [Symbol.iterator]: function () {
+            return (function*() {
+                for (let counter = 0; counter < list.length; counter += 1) {
+                    yield [counter, list[counter]];
+                }
+            })();
+        }
+    };
+};
\ No newline at end of file