From 59a4f49bfa5c611d1053d7e96dfcf9270be80f48 Mon Sep 17 00:00:00 2001
From: Mike Frawley <frawl021@gmail.com>
Date: Wed, 17 Feb 2010 09:05:45 -0600
Subject: [PATCH 01/13] Make internal var each = _.each

We use it everwhere, so this should be a slight speedup
but make code more readable
---
 underscore.js | 31 ++++++++++++++++---------------
 1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/underscore.js b/underscore.js
index faadaeb85..a115ed6d3 100644
--- a/underscore.js
+++ b/underscore.js
@@ -44,6 +44,7 @@
 
   // The cornerstone, an each implementation.
   // Handles objects implementing forEach, arrays, and raw objects.
+  var each = 
   _.each = function(obj, iterator, context) {
     var index = 0;
     try {
@@ -66,7 +67,7 @@
   _.map = function(obj, iterator, context) {
     if (obj && _.isFunction(obj.map)) return obj.map(iterator, context);
     var results = [];
-    _.each(obj, function(value, index, list) {
+    each(obj, function(value, index, list) {
       results.push(iterator.call(context, value, index, list));
     });
     return results;
@@ -76,7 +77,7 @@
   // inject, or foldl. Uses JavaScript 1.8's version of reduce, if possible.
   _.reduce = function(obj, memo, iterator, context) {
     if (obj && _.isFunction(obj.reduce)) return obj.reduce(_.bind(iterator, context), memo);
-    _.each(obj, function(value, index, list) {
+    each(obj, function(value, index, list) {
       memo = iterator.call(context, memo, value, index, list);
     });
     return memo;
@@ -87,7 +88,7 @@
   _.reduceRight = function(obj, memo, iterator, context) {
     if (obj && _.isFunction(obj.reduceRight)) return obj.reduceRight(_.bind(iterator, context), memo);
     var reversed = _.clone(_.toArray(obj)).reverse();
-    _.each(reversed, function(value, index) {
+    each(reversed, function(value, index) {
       memo = iterator.call(context, memo, value, index, obj);
     });
     return memo;
@@ -96,7 +97,7 @@
   // Return the first value which passes a truth test.
   _.detect = function(obj, iterator, context) {
     var result;
-    _.each(obj, function(value, index, list) {
+    each(obj, function(value, index, list) {
       if (iterator.call(context, value, index, list)) {
         result = value;
         _.breakLoop();
@@ -110,7 +111,7 @@
   _.select = function(obj, iterator, context) {
     if (obj && _.isFunction(obj.filter)) return obj.filter(iterator, context);
     var results = [];
-    _.each(obj, function(value, index, list) {
+    each(obj, function(value, index, list) {
       iterator.call(context, value, index, list) && results.push(value);
     });
     return results;
@@ -119,7 +120,7 @@
   // Return all the elements for which a truth test fails.
   _.reject = function(obj, iterator, context) {
     var results = [];
-    _.each(obj, function(value, index, list) {
+    each(obj, function(value, index, list) {
       !iterator.call(context, value, index, list) && results.push(value);
     });
     return results;
@@ -131,7 +132,7 @@
     iterator = iterator || _.identity;
     if (obj && _.isFunction(obj.every)) return obj.every(iterator, context);
     var result = true;
-    _.each(obj, function(value, index, list) {
+    each(obj, function(value, index, list) {
       if (!(result = result && iterator.call(context, value, index, list))) _.breakLoop();
     });
     return result;
@@ -143,7 +144,7 @@
     iterator = iterator || _.identity;
     if (obj && _.isFunction(obj.some)) return obj.some(iterator, context);
     var result = false;
-    _.each(obj, function(value, index, list) {
+    each(obj, function(value, index, list) {
       if (result = iterator.call(context, value, index, list)) _.breakLoop();
     });
     return result;
@@ -154,7 +155,7 @@
   _.include = function(obj, target) {
     if (obj && _.isFunction(obj.indexOf)) return _.indexOf(obj, target) != -1;
     var found = false;
-    _.each(obj, function(value) {
+    each(obj, function(value) {
       if (found = value === target) _.breakLoop();
     });
     return found;
@@ -177,7 +178,7 @@
   _.max = function(obj, iterator, context) {
     if (!iterator && _.isArray(obj)) return Math.max.apply(Math, obj);
     var result = {computed : -Infinity};
-    _.each(obj, function(value, index, list) {
+    each(obj, function(value, index, list) {
       var computed = iterator ? iterator.call(context, value, index, list) : value;
       computed >= result.computed && (result = {value : value, computed : computed});
     });
@@ -188,7 +189,7 @@
   _.min = function(obj, iterator, context) {
     if (!iterator && _.isArray(obj)) return Math.min.apply(Math, obj);
     var result = {computed : Infinity};
-    _.each(obj, function(value, index, list) {
+    each(obj, function(value, index, list) {
       var computed = iterator ? iterator.call(context, value, index, list) : value;
       computed < result.computed && (result = {value : value, computed : computed});
     });
@@ -356,7 +357,7 @@
   _.bindAll = function(obj) {
     var funcs = _.rest(arguments);
     if (funcs.length == 0) funcs = _.functions(obj);
-    _.each(funcs, function(f) { obj[f] = _.bind(obj[f], obj); });
+    each(funcs, function(f) { obj[f] = _.bind(obj[f], obj); });
     return obj;
   };
 
@@ -606,7 +607,7 @@
   };
 
   // Add all of the Underscore functions to the wrapper object.
-  _.each(_.functions(_), function(name) {
+  each(_.functions(_), function(name) {
     var method = _[name];
     wrapper.prototype[name] = function() {
       var args = _.toArray(arguments);
@@ -616,7 +617,7 @@
   });
 
   // Add all mutator Array functions to the wrapper.
-  _.each(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(name) {
+  each(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(name) {
     var method = Array.prototype[name];
     wrapper.prototype[name] = function() {
       method.apply(this._wrapped, arguments);
@@ -625,7 +626,7 @@
   });
 
   // Add all accessor Array functions to the wrapper.
-  _.each(['concat', 'join', 'slice'], function(name) {
+  each(['concat', 'join', 'slice'], function(name) {
     var method = Array.prototype[name];
     wrapper.prototype[name] = function() {
       return result(method.apply(this._wrapped, arguments), this._chain);

From 7ec8d12d6c4644dcdade95c06125aca26f3e748f Mon Sep 17 00:00:00 2001
From: Mike Frawley <frawl021@gmail.com>
Date: Wed, 17 Feb 2010 09:16:10 -0600
Subject: [PATCH 02/13] rename underscore methods after the native [] method
 names, aliases for ruby versions

Even though the native methods have worse names (forEach, every, some),
since this library is trying to smooth over the native language it makes
more sense to use the native names, and provide aliases for more sensible
names from other languages, not the other way around.

Note this doesn't change any external usage, it just makes more sense.

This should also be useful for abstraction purposes for building underscore
functions, something like:

  addFn('some', {has_native: true, our_version: function () {...}})

this way we could feature detect on load for native versions and build a
function, and also have the option to turn off native versions for testing
our implementation.

I Also standardized the comments to look like:
  Delegates to JavaScript 1.x's native y if available.
---
 underscore.js | 43 +++++++++++++++++++++++--------------------
 1 file changed, 23 insertions(+), 20 deletions(-)

diff --git a/underscore.js b/underscore.js
index a115ed6d3..20b18eba6 100644
--- a/underscore.js
+++ b/underscore.js
@@ -44,8 +44,9 @@
 
   // The cornerstone, an each implementation.
   // Handles objects implementing forEach, arrays, and raw objects.
+  // Delegates to JavaScript 1.6's native forEach if available.
   var each = 
-  _.each = function(obj, iterator, context) {
+  _.forEach = function(obj, iterator, context) {
     var index = 0;
     try {
       if (obj.forEach) {
@@ -62,8 +63,8 @@
     return obj;
   };
 
-  // Return the results of applying the iterator to each element. Use JavaScript
-  // 1.6's version of map, if possible.
+  // Return the results of applying the iterator to each element. 
+  // Delegates to JavaScript 1.6's native map if available.
   _.map = function(obj, iterator, context) {
     if (obj && _.isFunction(obj.map)) return obj.map(iterator, context);
     var results = [];
@@ -74,7 +75,8 @@
   };
 
   // Reduce builds up a single result from a list of values. Also known as
-  // inject, or foldl. Uses JavaScript 1.8's version of reduce, if possible.
+  // inject, or foldl.
+  // Delegates to JavaScript 1.8's native reduce if available.
   _.reduce = function(obj, memo, iterator, context) {
     if (obj && _.isFunction(obj.reduce)) return obj.reduce(_.bind(iterator, context), memo);
     each(obj, function(value, index, list) {
@@ -84,7 +86,7 @@
   };
 
   // The right-associative version of reduce, also known as foldr. Uses
-  // JavaScript 1.8's version of reduceRight, if available.
+  // Delegates to JavaScript 1.8's native reduceRight if available.
   _.reduceRight = function(obj, memo, iterator, context) {
     if (obj && _.isFunction(obj.reduceRight)) return obj.reduceRight(_.bind(iterator, context), memo);
     var reversed = _.clone(_.toArray(obj)).reverse();
@@ -106,9 +108,9 @@
     return result;
   };
 
-  // Return all the elements that pass a truth test. Use JavaScript 1.6's
-  // filter(), if it exists.
-  _.select = function(obj, iterator, context) {
+  // Return all the elements that pass a truth test. 
+  // Delegates to JavaScript 1.6's native filter if available.
+  _.filter = function(obj, iterator, context) {
     if (obj && _.isFunction(obj.filter)) return obj.filter(iterator, context);
     var results = [];
     each(obj, function(value, index, list) {
@@ -126,9 +128,9 @@
     return results;
   };
 
-  // Determine whether all of the elements match a truth test. Delegate to
-  // JavaScript 1.6's every(), if it is present.
-  _.all = function(obj, iterator, context) {
+  // Determine whether all of the elements match a truth test. 
+  // Delegates to JavaScript 1.6's native every if available.
+  _.every = function(obj, iterator, context) {
     iterator = iterator || _.identity;
     if (obj && _.isFunction(obj.every)) return obj.every(iterator, context);
     var result = true;
@@ -138,9 +140,9 @@
     return result;
   };
 
-  // Determine if at least one element in the object matches a truth test. Use
-  // JavaScript 1.6's some(), if it exists.
-  _.any = function(obj, iterator, context) {
+  // Determine if at least one element in the object matches a truth test.
+  // Delegates to JavaScript 1.6's native some if available.
+  _.some = function(obj, iterator, context) {
     iterator = iterator || _.identity;
     if (obj && _.isFunction(obj.some)) return obj.some(iterator, context);
     var result = false;
@@ -310,14 +312,15 @@
   // If the browser doesn't supply us with indexOf (I'm looking at you, MSIE),
   // we need this function. Return the position of the first occurence of an
   // item in an array, or -1 if the item is not included in the array.
+  // Delegates to JavaScript 1.8's native indexOf if available.
   _.indexOf = function(array, item) {
     if (array.indexOf) return array.indexOf(item);
     for (var i=0, l=array.length; i<l; i++) if (array[i] === item) return i;
     return -1;
   };
 
-  // Provide JavaScript 1.6's lastIndexOf, delegating to the native function,
-  // if possible.
+
+  // Delegates to JavaScript 1.6's native lastIndexOf if available.
   _.lastIndexOf = function(array, item) {
     if (array.lastIndexOf) return array.lastIndexOf(item);
     var i = array.length;
@@ -589,12 +592,12 @@
 
   // ------------------------------- Aliases ----------------------------------
 
-  _.forEach  = _.each;
+  _.each     = _.forEach;
   _.foldl    = _.inject       = _.reduce;
   _.foldr    = _.reduceRight;
-  _.filter   = _.select;
-  _.every    = _.all;
-  _.some     = _.any;
+  _.select   = _.filter;
+  _.all      = _.every;
+  _.any      = _.some;
   _.head     = _.first;
   _.tail     = _.rest;
   _.methods  = _.functions;

From c4daac089b26ba67dcd477b9babaeb3c37d2d19a Mon Sep 17 00:00:00 2001
From: Mike Frawley <frawl021@gmail.com>
Date: Wed, 17 Feb 2010 09:26:34 -0600
Subject: [PATCH 03/13] delegate to native Object.keys in nightlies

---
 underscore.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/underscore.js b/underscore.js
index 20b18eba6..ac694195e 100644
--- a/underscore.js
+++ b/underscore.js
@@ -403,7 +403,8 @@
   // ------------------------- Object Functions: ------------------------------
 
   // Retrieve the names of an object's properties.
-  _.keys = function(obj) {
+  // ECMA5 has Object.keys(obj) in webkit nightlies 
+  _.keys = Object.keys || function(obj) {
     if (_.isArray(obj)) return _.range(0, obj.length);
     var keys = [];
     for (var key in obj) if (hasOwnProperty.call(obj, key)) keys.push(key);

From c43de549bacd3f6def734317656ddae7fa52c4cf Mon Sep 17 00:00:00 2001
From: Mike Frawley <frawl021@gmail.com>
Date: Wed, 17 Feb 2010 09:41:18 -0600
Subject: [PATCH 04/13] Create #alias method, callable on any object, _ by
 default.

While I'm not a fan of making abstractions where a simpe solution
exists, I think this is good as it makes a public API for extending
underscore, therefore making it "ok" to make your own alias names.

Also give us some future proofing in case we ever add in hooks on
method definition. For example, right now if you add a method
or make an alias in user code, it isn't added to the wrapper prototype.

Added tests and inline docs, no external docs
---
 test/objects.js | 17 ++++++++++++++++-
 underscore.js   | 43 ++++++++++++++++++++++++++++++++++---------
 2 files changed, 50 insertions(+), 10 deletions(-)

diff --git a/test/objects.js b/test/objects.js
index c1c4aa327..8743eaed8 100644
--- a/test/objects.js
+++ b/test/objects.js
@@ -11,7 +11,7 @@ $(document).ready(function() {
   });
 
   test("objects: functions", function() {
-    var expected = ["all", "any", "bind", "bindAll", "breakLoop", "clone", "compact",
+    var expected = ["alias", "all", "any", "bind", "bindAll", "breakLoop", "clone", "compact",
     "compose","defer", "delay", "detect", "each", "every", "extend", "filter", "first",
     "flatten", "foldl", "foldr", "forEach", "functions", "head", "identity", "include",
     "indexOf", "inject", "intersect", "invoke", "isArguments", "isArray", "isDate", "isElement", "isEmpty", "isEqual",
@@ -183,4 +183,19 @@ $(document).ready(function() {
       value();
     ok(returned == 6 && intercepted == 6, 'can use tapped objects in a chain');
   });
+  
+
+  test("objects: alias", function() {
+    _.alias('isEqual', 'isTheSame');
+    ok(_.isTheSame(9, 9), 'by default aliases methods on underscore');
+    delete _.isTheSame;
+    //
+    var o = { hi: function () {return 9;} };
+    _.alias(o, 'hi', 'ho');
+    equals(o.ho(), 9, 'can add an alias on another object');
+    _.alias(o, 'hi', 'there', 'sir');
+    ok(o.hi==o.sir, 'can add multiple aliases');
+  });
+  
+  
 });
diff --git a/underscore.js b/underscore.js
index ac694195e..538019fc8 100644
--- a/underscore.js
+++ b/underscore.js
@@ -440,6 +440,31 @@
     return obj;
   };
 
+  // Alias a method on an object to another name(s).
+  // If the first argument is NOT an object, then the object is assumed to 
+  // be underscore.
+  // The first string argument is the existing method name, any following
+  // strings will be aliased to that name.  
+  // Returns the object for chainability.
+  //
+  // Examples:
+  //
+  // Alias isEquals to isSame and eql on underscore:
+  //    _.alias('isEqual', 'isSame', 'eql');
+  //
+  // Alias `toString` to `to_s` on a given object: 
+  //    _.alias({}, 'toString', 'to_s')
+  //
+  // Implementation: explicitly cast arguments to array as calling mutating
+  // array methods on arguments object has strange behavior (at least in FF 3.6) 
+  _.alias = function () {
+    var args = _.toArray(arguments), 
+        obj = (typeof args[0] === 'string')?  _ : args.shift(),
+        fn = obj[args.shift()];
+    each(args, function (alias) {  obj[alias] = fn;  });
+    return obj;
+  };
+
   // Perform a deep comparison to check if two objects are equal.
   _.isEqual = function(a, b) {
     // Check object identity.
@@ -593,15 +618,15 @@
 
   // ------------------------------- Aliases ----------------------------------
 
-  _.each     = _.forEach;
-  _.foldl    = _.inject       = _.reduce;
-  _.foldr    = _.reduceRight;
-  _.select   = _.filter;
-  _.all      = _.every;
-  _.any      = _.some;
-  _.head     = _.first;
-  _.tail     = _.rest;
-  _.methods  = _.functions;
+  _.alias('forEach', 'each').
+    alias('reduce', 'foldl', 'inject').
+    alias('reduceRight', 'foldr').
+    alias('filter', 'select').
+    alias('every', 'all').
+    alias('some', 'any').
+    alias('first', 'head').
+    alias('rest', 'tail').
+    alias('functions', 'methods');
 
   // ------------------------ Setup the OOP Wrapper: --------------------------
 

From 386ee8ade99a1ec68378e4e0caba9c3ac28e91f8 Mon Sep 17 00:00:00 2001
From: Mike Frawley <frawl021@gmail.com>
Date: Wed, 17 Feb 2010 09:45:24 -0600
Subject: [PATCH 05/13] add reference to underscore.js on docs page, since this
 is a good place to play around with it in the console

---
 index.html | 1 +
 1 file changed, 1 insertion(+)

diff --git a/index.html b/index.html
index 8e26a9659..7332f4c88 100644
--- a/index.html
+++ b/index.html
@@ -4,6 +4,7 @@
   <meta http-equiv="content-type" content="text/html;charset=UTF-8" />
   <meta http-equiv="X-UA-Compatible" content="chrome=1">
   <title>Underscore.js</title>
+  <script src="underscore.js"></script>
   <style>
     body {
       font-size: 16px;

From 130e860ecf2f42bddf503cb603d8e2f2661034db Mon Sep 17 00:00:00 2001
From: Mike Frawley <frawl021@gmail.com>
Date: Wed, 17 Feb 2010 09:48:29 -0600
Subject: [PATCH 06/13] improve #isEmpty implementation.  add 2 tests

---
 test/objects.js | 2 ++
 underscore.js   | 4 +++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/test/objects.js b/test/objects.js
index 8743eaed8..272b66ef1 100644
--- a/test/objects.js
+++ b/test/objects.js
@@ -60,6 +60,8 @@ $(document).ready(function() {
     ok(_.isEmpty([]), '[] is empty');
     ok(!_.isEmpty({one : 1}), '{one : 1} is not empty');
     ok(_.isEmpty({}), '{} is empty');
+    ok(_.isEmpty(null), 'null is empty');
+    ok(_.isEmpty(), 'undefined is empty');
 
     var obj = {one : 1};
     delete obj.one;
diff --git a/underscore.js b/underscore.js
index 538019fc8..88433489f 100644
--- a/underscore.js
+++ b/underscore.js
@@ -503,7 +503,9 @@
 
   // Is a given array or object empty?
   _.isEmpty = function(obj) {
-    return _.keys(obj).length == 0;
+    if (_.isArray(obj)) return obj.length===0;
+    for (var k in obj) return false;
+    return true;
   };
 
   // Is a given value a DOM element?

From 76bbfddd95933553aff75158b06e230f57dcaad7 Mon Sep 17 00:00:00 2001
From: Mike Frawley <frawl021@gmail.com>
Date: Wed, 17 Feb 2010 09:51:38 -0600
Subject: [PATCH 07/13] our #reduceRight delegates to #reduce after reversing.

no need to reimplement it.

also, reduceRight is worthless :)
---
 underscore.js | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/underscore.js b/underscore.js
index 88433489f..6c9004370 100644
--- a/underscore.js
+++ b/underscore.js
@@ -90,10 +90,7 @@
   _.reduceRight = function(obj, memo, iterator, context) {
     if (obj && _.isFunction(obj.reduceRight)) return obj.reduceRight(_.bind(iterator, context), memo);
     var reversed = _.clone(_.toArray(obj)).reverse();
-    each(reversed, function(value, index) {
-      memo = iterator.call(context, memo, value, index, obj);
-    });
-    return memo;
+    return reduce(reversed, memo, iterator, context);
   };
 
   // Return the first value which passes a truth test.

From 1b1943b0caa7b54d0f6bb1dbba65c7b5439784c9 Mon Sep 17 00:00:00 2001
From: Mike Frawley <frawl021@gmail.com>
Date: Wed, 17 Feb 2010 09:53:36 -0600
Subject: [PATCH 08/13] implement include in terms of detect

---
 underscore.js | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/underscore.js b/underscore.js
index 6c9004370..cce9756a4 100644
--- a/underscore.js
+++ b/underscore.js
@@ -149,15 +149,12 @@
     return result;
   };
 
-  // Determine if a given value is included in the array or object,
-  // based on '==='.
+  // Determine if a given value is included in the array or object using '==='.
   _.include = function(obj, target) {
     if (obj && _.isFunction(obj.indexOf)) return _.indexOf(obj, target) != -1;
-    var found = false;
-    each(obj, function(value) {
-      if (found = value === target) _.breakLoop();
+    return !! _.detect(obj, function(value) {
+      return value === target;
     });
-    return found;
   };
 
   // Invoke a method with arguments on every item in a collection.

From 263b1ee92d49147e6a507e3316141d66a912c760 Mon Sep 17 00:00:00 2001
From: Mike Frawley <frawl021@gmail.com>
Date: Wed, 17 Feb 2010 10:12:22 -0600
Subject: [PATCH 09/13] add #buildLookup method to turn collection in to a fast
 lookup hash

implement #without in terms of it
add tests and internal docs
---
 test/collections.js |  7 +++++++
 test/objects.js     |  2 +-
 underscore.js       | 22 ++++++++++++++++++++--
 3 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/test/collections.js b/test/collections.js
index 3759a6495..516dbf334 100644
--- a/test/collections.js
+++ b/test/collections.js
@@ -164,5 +164,12 @@ $(document).ready(function() {
   test('collections: size', function() {
     equals(_.size({one : 1, two : 2, three : 3}), 3, 'can compute the size of an object');
   });
+  
+  test('collections: buildLookup', function() {
+    same(_.buildLookup([1,'hi']), {1:true, 'hi':true}, 'defaults values to true');
+    same(_.buildLookup([1,'hi'], 1), {1:1, 'hi':1}, 'can override value');
+    same(_.buildLookup({5:'five'}), {five: true}, 'making a map from an object uses its values');
+  });
+  
 
 });
diff --git a/test/objects.js b/test/objects.js
index 272b66ef1..02e00abd1 100644
--- a/test/objects.js
+++ b/test/objects.js
@@ -11,7 +11,7 @@ $(document).ready(function() {
   });
 
   test("objects: functions", function() {
-    var expected = ["alias", "all", "any", "bind", "bindAll", "breakLoop", "clone", "compact",
+    var expected = ["alias", "all", "any", "bind", "bindAll", "breakLoop", "buildLookup", "clone", "compact",
     "compose","defer", "delay", "detect", "each", "every", "extend", "filter", "first",
     "flatten", "foldl", "foldr", "forEach", "functions", "head", "identity", "include",
     "indexOf", "inject", "intersect", "invoke", "isArguments", "isArray", "isDate", "isElement", "isEmpty", "isEqual",
diff --git a/underscore.js b/underscore.js
index cce9756a4..6c120a772 100644
--- a/underscore.js
+++ b/underscore.js
@@ -230,6 +230,24 @@
   _.size = function(obj) {
     return _.toArray(obj).length;
   };
+  
+  // Build a lookup map from a collection.
+  // Pay a little memory upfront to make searching a collection for a 
+  // value faster later
+  // e.g:
+  //
+  //  var lookup = _.buildLookup([1,2,8])  // {1: true, 2: true, 8: true}
+  //  lookup[key]   // instead of: _.include(array, key)
+  //
+  // See example usage in #without
+  // By default sets the value to true, can pass in a value to use instead
+  _.buildLookup = function (obj, useValue) {
+    useValue = (useValue === undefined)?  true :  useValue;
+    return _.reduce(obj, {}, function (memo, value) {  
+      memo[value] = useValue;  
+      return memo;
+    });
+  };   
 
   // -------------------------- Array Functions: ------------------------------
 
@@ -269,8 +287,8 @@
 
   // Return a version of the array that does not contain the specified value(s).
   _.without = function(array) {
-    var values = _.rest(arguments);
-    return _.select(array, function(value){ return !_.include(values, value); });
+    var lookup = _.buildLookup(_.rest(arguments));
+    return _.filter(array, function(value){ return !lookup[value]; });
   };
 
   // Produce a duplicate-free version of the array. If the array has already

From 5a5e14d7a4e3c9271575acae3048cb7e8096ff72 Mon Sep 17 00:00:00 2001
From: Mike Frawley <frawl021@gmail.com>
Date: Wed, 17 Feb 2010 10:21:59 -0600
Subject: [PATCH 10/13] add #times utility method.

_(3).times(alert)

added tests and internal docs
---
 test/objects.js |  2 +-
 test/utility.js | 11 +++++++++++
 underscore.js   |  7 +++++++
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/test/objects.js b/test/objects.js
index 02e00abd1..71e46bdb6 100644
--- a/test/objects.js
+++ b/test/objects.js
@@ -17,7 +17,7 @@ $(document).ready(function() {
     "indexOf", "inject", "intersect", "invoke", "isArguments", "isArray", "isDate", "isElement", "isEmpty", "isEqual",
     "isFunction", "isNaN", "isNull", "isNumber", "isRegExp", "isString", "isUndefined", "keys", "last", "lastIndexOf", "map", "max",
     "methods", "min", "noConflict", "pluck", "range", "reduce", "reduceRight", "reject", "rest", "select",
-    "size", "some", "sortBy", "sortedIndex", "tail", "tap", "template", "toArray", "uniq",
+    "size", "some", "sortBy", "sortedIndex", "tail", "tap", "template", "times", "toArray", "uniq",
     "uniqueId", "values", "without", "wrap", "zip"];
     ok(_(expected).isEqual(_.methods(_)), 'provides a sorted list of functions');
     var obj = {a : 'dash', b : _.map, c : (/yo/), d : _.reduce};
diff --git a/test/utility.js b/test/utility.js
index 763a48036..b006dee32 100644
--- a/test/utility.js
+++ b/test/utility.js
@@ -29,6 +29,17 @@ $(document).ready(function() {
     while(i++ < 100) ids.push(_.uniqueId());
     equals(_.uniq(ids).length, ids.length, 'can generate a globally-unique stream of ids');
   });
+  
+  test("utility: times", function() {
+    var vals = [];
+    _.times(3, function (i) { vals.push(i); });
+    ok(_.isEqual(vals, [0,1,2]), "is 0 indexed");
+    //
+    vals = [];
+    _(3).times(function (i) { vals.push(i); });
+    ok(_.isEqual(vals, [0,1,2]), "works as a wrapper");
+  });
+  
 
   test("utility: template", function() {
     var basicTemplate = _.template("<%= thing %> is gettin' on my noives!");
diff --git a/underscore.js b/underscore.js
index 6c120a772..cf6a1578e 100644
--- a/underscore.js
+++ b/underscore.js
@@ -589,6 +589,13 @@
   _.identity = function(value) {
     return value;
   };
+  
+  // run a function n times.  
+  // looks good in wrapper form:
+  //    _(3).times(alert)
+  _.times = function (n, fn, context) {
+    for (var i=0; i < n; i++)  fn.call(context, i)
+  };
 
   // Break out of the middle of an iteration.
   _.breakLoop = function() {

From b774bf7ca9770625c0dffa99d46c14f22fdf7776 Mon Sep 17 00:00:00 2001
From: Mike Frawley <frawl021@gmail.com>
Date: Mon, 22 Feb 2010 14:37:54 -0600
Subject: [PATCH 11/13] delegate to ECMA5 native Array.isArray if available

---
 underscore.js | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/underscore.js b/underscore.js
index cf6a1578e..bd74fbcf5 100644
--- a/underscore.js
+++ b/underscore.js
@@ -415,7 +415,7 @@
   // ------------------------- Object Functions: ------------------------------
 
   // Retrieve the names of an object's properties.
-  // ECMA5 has Object.keys(obj) in webkit nightlies 
+  // Delegates to ECMA5's native Object.keys
   _.keys = Object.keys || function(obj) {
     if (_.isArray(obj)) return _.range(0, obj.length);
     var keys = [];
@@ -526,7 +526,8 @@
   };
 
   // Is a given value an array?
-  _.isArray = function(obj) {
+  // Delegates to ECMA5's native Array.isArray
+  _.isArray = Array.isArray || function(obj) {
     return !!(obj && obj.concat && obj.unshift);
   };
 

From bb250e7205b9e0b481233ae2bcf542d2e288dfd7 Mon Sep 17 00:00:00 2001
From: Mike Frawley <frawl021@gmail.com>
Date: Mon, 22 Feb 2010 15:50:01 -0600
Subject: [PATCH 12/13] Much better strategy for calling native Array methods.

Compare an object's function with === to the native
version before calling it.  That is, don't just assume that
because an object has a 'filter' property thats a function,
that we should call that in _.filter().

Expose the native methods found as _.native

On the way towards being able to turn off native implementations,
though there are tradeoffs...
---
 underscore.js | 43 +++++++++++++++++++++++++++++++------------
 1 file changed, 31 insertions(+), 12 deletions(-)

diff --git a/underscore.js b/underscore.js
index bd74fbcf5..a445cdcb0 100644
--- a/underscore.js
+++ b/underscore.js
@@ -37,6 +37,25 @@
       hasOwnProperty        = Object.prototype.hasOwnProperty,
       propertyIsEnumerable  = Object.prototype.propertyIsEnumerable;
 
+  // All native implementations we hope to use are declared here, 
+  // mostly Array.prototype methods.
+  //
+  // 'native' is on the long list of reserved words.  
+  // Ok to use as a property name, though jsLint doesn't agree.
+  var Native = _['native'] = {
+    forEach:        Array.prototype.forEach,
+    map:            Array.prototype.map,
+    reduce:         Array.prototype.reduce,
+    reduceRight:    Array.prototype.reduceRight,
+    filter:         Array.prototype.filter,
+    every:          Array.prototype.every,
+    some:           Array.prototype.some,
+    indexOf:        Array.prototype.indexOf,
+    lastIndexOf:    Array.prototype.lastIndexOf,
+    isArray:        Array.isArray,
+    keys:           Object.keys
+  };
+  
   // Current version.
   _.VERSION = '0.5.8';
 
@@ -49,7 +68,7 @@
   _.forEach = function(obj, iterator, context) {
     var index = 0;
     try {
-      if (obj.forEach) {
+      if (obj.forEach === Native.forEach) {
         obj.forEach(iterator, context);
       } else if (_.isNumber(obj.length)) {
         for (var i=0, l=obj.length; i<l; i++) iterator.call(context, obj[i], i, obj);
@@ -66,7 +85,7 @@
   // Return the results of applying the iterator to each element. 
   // Delegates to JavaScript 1.6's native map if available.
   _.map = function(obj, iterator, context) {
-    if (obj && _.isFunction(obj.map)) return obj.map(iterator, context);
+    if (obj.map === Native.map) return obj.map(iterator, context);
     var results = [];
     each(obj, function(value, index, list) {
       results.push(iterator.call(context, value, index, list));
@@ -78,7 +97,7 @@
   // inject, or foldl.
   // Delegates to JavaScript 1.8's native reduce if available.
   _.reduce = function(obj, memo, iterator, context) {
-    if (obj && _.isFunction(obj.reduce)) return obj.reduce(_.bind(iterator, context), memo);
+    if (obj.reduce === Native.reduce) return obj.reduce(_.bind(iterator, context), memo);
     each(obj, function(value, index, list) {
       memo = iterator.call(context, memo, value, index, list);
     });
@@ -88,7 +107,7 @@
   // The right-associative version of reduce, also known as foldr. Uses
   // Delegates to JavaScript 1.8's native reduceRight if available.
   _.reduceRight = function(obj, memo, iterator, context) {
-    if (obj && _.isFunction(obj.reduceRight)) return obj.reduceRight(_.bind(iterator, context), memo);
+    if (obj.reduceRight === Native.reduceRight) return obj.reduceRight(_.bind(iterator, context), memo);
     var reversed = _.clone(_.toArray(obj)).reverse();
     return reduce(reversed, memo, iterator, context);
   };
@@ -108,7 +127,7 @@
   // Return all the elements that pass a truth test. 
   // Delegates to JavaScript 1.6's native filter if available.
   _.filter = function(obj, iterator, context) {
-    if (obj && _.isFunction(obj.filter)) return obj.filter(iterator, context);
+    if (obj.filter === Native.filter) return obj.filter(iterator, context);
     var results = [];
     each(obj, function(value, index, list) {
       iterator.call(context, value, index, list) && results.push(value);
@@ -129,7 +148,7 @@
   // Delegates to JavaScript 1.6's native every if available.
   _.every = function(obj, iterator, context) {
     iterator = iterator || _.identity;
-    if (obj && _.isFunction(obj.every)) return obj.every(iterator, context);
+    if (obj.every === Native.every) return obj.every(iterator, context);
     var result = true;
     each(obj, function(value, index, list) {
       if (!(result = result && iterator.call(context, value, index, list))) _.breakLoop();
@@ -141,7 +160,7 @@
   // Delegates to JavaScript 1.6's native some if available.
   _.some = function(obj, iterator, context) {
     iterator = iterator || _.identity;
-    if (obj && _.isFunction(obj.some)) return obj.some(iterator, context);
+    if (obj.some === Native.some) return obj.some(iterator, context);
     var result = false;
     each(obj, function(value, index, list) {
       if (result = iterator.call(context, value, index, list)) _.breakLoop();
@@ -326,7 +345,7 @@
   // item in an array, or -1 if the item is not included in the array.
   // Delegates to JavaScript 1.8's native indexOf if available.
   _.indexOf = function(array, item) {
-    if (array.indexOf) return array.indexOf(item);
+    if (array.indexOf === Native.indexOf) return array.indexOf(item);
     for (var i=0, l=array.length; i<l; i++) if (array[i] === item) return i;
     return -1;
   };
@@ -334,7 +353,7 @@
 
   // Delegates to JavaScript 1.6's native lastIndexOf if available.
   _.lastIndexOf = function(array, item) {
-    if (array.lastIndexOf) return array.lastIndexOf(item);
+    if (array.lastIndexOf === Native.lastIndexOf) return array.lastIndexOf(item);
     var i = array.length;
     while (i--) if (array[i] === item) return i;
     return -1;
@@ -416,7 +435,7 @@
 
   // Retrieve the names of an object's properties.
   // Delegates to ECMA5's native Object.keys
-  _.keys = Object.keys || function(obj) {
+  _.keys = Native.keys || function(obj) {
     if (_.isArray(obj)) return _.range(0, obj.length);
     var keys = [];
     for (var key in obj) if (hasOwnProperty.call(obj, key)) keys.push(key);
@@ -515,7 +534,7 @@
 
   // Is a given array or object empty?
   _.isEmpty = function(obj) {
-    if (_.isArray(obj)) return obj.length===0;
+    if (_.isArray(obj)) return obj.length === 0;
     for (var k in obj) return false;
     return true;
   };
@@ -527,7 +546,7 @@
 
   // Is a given value an array?
   // Delegates to ECMA5's native Array.isArray
-  _.isArray = Array.isArray || function(obj) {
+  _.isArray = Native.isArray || function(obj) {
     return !!(obj && obj.concat && obj.unshift);
   };
 

From 31f0f8c54cb5211cc48f6a1ee92fcedc4ed89a20 Mon Sep 17 00:00:00 2001
From: Mike Frawley <frawl021@gmail.com>
Date: Mon, 22 Feb 2010 15:57:23 -0600
Subject: [PATCH 13/13] make a local variable that points to Array.prototype
 since the former is not min'd down.
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Won't effect gzip size, but reduces min size.  Saves about:

15 bytes per instance * 13 instances ≅ 200 bytes
---
 underscore.js | 33 +++++++++++++++++----------------
 1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/underscore.js b/underscore.js
index a445cdcb0..5e0297322 100644
--- a/underscore.js
+++ b/underscore.js
@@ -30,28 +30,29 @@
   // Export the Underscore object for CommonJS.
   if (typeof exports !== 'undefined') exports._ = _;
 
+  // Save bytes in the minified (but not gzipped) version:
+  var ArrayPrototype = Array.prototype;
+  
   // Create quick reference variables for speed access to core prototypes.
-  var slice                 = Array.prototype.slice,
-      unshift               = Array.prototype.unshift,
+  var slice                 = ArrayPrototype.slice,
+      unshift               = ArrayPrototype.unshift,
       toString              = Object.prototype.toString,
       hasOwnProperty        = Object.prototype.hasOwnProperty,
       propertyIsEnumerable  = Object.prototype.propertyIsEnumerable;
 
-  // All native implementations we hope to use are declared here, 
-  // mostly Array.prototype methods.
-  //
+  // All native implementations we hope to use are declared here.
   // 'native' is on the long list of reserved words.  
   // Ok to use as a property name, though jsLint doesn't agree.
   var Native = _['native'] = {
-    forEach:        Array.prototype.forEach,
-    map:            Array.prototype.map,
-    reduce:         Array.prototype.reduce,
-    reduceRight:    Array.prototype.reduceRight,
-    filter:         Array.prototype.filter,
-    every:          Array.prototype.every,
-    some:           Array.prototype.some,
-    indexOf:        Array.prototype.indexOf,
-    lastIndexOf:    Array.prototype.lastIndexOf,
+    forEach:        ArrayPrototype.forEach,
+    map:            ArrayPrototype.map,
+    reduce:         ArrayPrototype.reduce,
+    reduceRight:    ArrayPrototype.reduceRight,
+    filter:         ArrayPrototype.filter,
+    every:          ArrayPrototype.every,
+    some:           ArrayPrototype.some,
+    indexOf:        ArrayPrototype.indexOf,
+    lastIndexOf:    ArrayPrototype.lastIndexOf,
     isArray:        Array.isArray,
     keys:           Object.keys
   };
@@ -688,7 +689,7 @@
 
   // Add all mutator Array functions to the wrapper.
   each(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(name) {
-    var method = Array.prototype[name];
+    var method = ArrayPrototype[name];
     wrapper.prototype[name] = function() {
       method.apply(this._wrapped, arguments);
       return result(this._wrapped, this._chain);
@@ -697,7 +698,7 @@
 
   // Add all accessor Array functions to the wrapper.
   each(['concat', 'join', 'slice'], function(name) {
-    var method = Array.prototype[name];
+    var method = ArrayPrototype[name];
     wrapper.prototype[name] = function() {
       return result(method.apply(this._wrapped, arguments), this._chain);
     };