From 42637b5880f040e8ce48ff7de758d2274919ffb8 Mon Sep 17 00:00:00 2001
From: Jeremy Ashkenas <jashkenas@gmail.com>
Date: Thu, 29 Oct 2009 10:46:53 -0400
Subject: [PATCH] Issue #2 -- each now calls iterator with (value, key, list)
 when iterating over javascript objects

---
 index.html          |  7 +++----
 test/collections.js |  4 ++--
 underscore.js       | 24 +++++++++++++-----------
 3 files changed, 18 insertions(+), 17 deletions(-)

diff --git a/index.html b/index.html
index f032259a6..33716be85 100644
--- a/index.html
+++ b/index.html
@@ -171,10 +171,9 @@
         <br />
         Iterates over a <b>list</b> of elements, yielding each in turn to an <b>iterator</b>
         function. The <b>iterator</b> is bound to the <b>context</b> object, if one is
-        passed. Each invocation of <b>iterator</b> is called with three arguments,
-        <i>element</i>, <i>index</i>, and the <b>list</b>. 
-        If <b>list</b> is a JavaScript object, a pair with <b>key</b>
-        and <b>value</b> properties will be yielded. If the list has an <b>each</b> 
+        passed. Each invocation of <b>iterator</b> is called with three arguments:
+        <tt>(element, index, list)</tt>. If <b>list</b> is a JavaScript object, <b>iterator</b>'s
+        arguments will be <tt>(value, key, list)</tt>. If the <b>list</b> has an <b>each</b> 
         method of its own, it will be used instead. Delegates to the native 
         <b>forEach</b> function if it exists.
       </p>
diff --git a/test/collections.js b/test/collections.js
index 69fe9ec47..3ef2ccba3 100644
--- a/test/collections.js
+++ b/test/collections.js
@@ -26,7 +26,7 @@ $(document).ready(function() {
     answers = [];
     var obj = {one : 1, two : 2, three : 3};
     obj.constructor.prototype.four = 4;
-    _.each(obj, function(pair){ answers.push(pair.key); });
+    _.each(obj, function(value, key){ answers.push(key); });
     equals(answers.join(", "), 'one, two, three', 'iterating over objects works, and ignores the object prototype.');
     delete obj.constructor.prototype.four;
     
@@ -136,7 +136,7 @@ $(document).ready(function() {
     ok(_.isArray(_.toArray(arguments)), 'arguments object converted into array');
     
     var numbers = _.toArray({one : 1, two : 2, three : 3});
-    equals(_.pluck(numbers, '0').join(', '), 'one, two, three', 'object flattened into array');
+    equals(numbers.join(', '), '1, 2, 3', 'object flattened into array');
   });
   
   test('collections: size', function() {
diff --git a/underscore.js b/underscore.js
index 90cafc284..f9c642062 100644
--- a/underscore.js
+++ b/underscore.js
@@ -42,12 +42,8 @@
       } else if (obj.each) {
         obj.each(function(value) { iterator.call(context, value, index++, obj); });
       } else {
-        var i = 0;
         for (var key in obj) if (Object.prototype.hasOwnProperty.call(obj, key)) {
-          var value = obj[key], pair = [key, value];
-          pair.key = key;
-          pair.value = value;
-          iterator.call(context, pair, i++, obj);
+          iterator.call(context, obj[key], key, obj);
         }
       }
     } catch(e) {
@@ -61,8 +57,8 @@
   _.map = function(obj, iterator, context) {
     if (obj && obj.map) return obj.map(iterator, context);
     var results = [];
-    _.each(obj, function(value, index) {
-      results.push(iterator.call(context, value, index));
+    _.each(obj, function(value, index, list) {
+      results.push(iterator.call(context, value, index, list));
     });
     return results;
   };
@@ -137,8 +133,8 @@
   _.include = function(obj, target) {
     if (_.isArray(obj)) return _.indexOf(obj, target) != -1;
     var found = false;
-    _.each(obj, function(pair) {
-      if (found = pair.value === target) {
+    _.each(obj, function(value) {
+      if (found = value === target) {
         throw '__break__';
       }
     });
@@ -361,12 +357,18 @@
   
   // Retrieve the names of an object's properties.
   _.keys = function(obj) {
-    return _.pluck(obj, 'key');
+    return _.reduce(obj, [], function(memo, value, key) { 
+      memo.push(key);
+      return memo;
+    });
   };
   
   // Retrieve the values of an object's properties.
   _.values = function(obj) {
-    return _.pluck(obj, 'value');
+    return _.reduce(obj, [], function(memo, value) { 
+      memo.push(value); 
+      return memo; 
+    });
   };
   
   // Extend a given object with all of the properties in a source object.