upgrade backbone to 1.1.1 and underscore to 1.6.0

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

architecture-examples/backbone/bower.json

@@ -2,8 +2,8 @@
   "name": "todomvc-backbone",
   "version": "0.0.0",
   "dependencies": {
-    "backbone": "~1.1.0",
-    "underscore": "~1.5.0",
+    "backbone": "~1.1.1",
+    "underscore": "~1.6.0",
     "jquery": "~2.0.0",
     "todomvc-common": "~0.1.4",
     "backbone.localStorage": "~1.1.0"

architecture-examples/backbone/bower_components/backbone/backbone.js

-//     Backbone.js 1.1.0
+//     Backbone.js 1.1.1
 
-//     (c) 2010-2011 Jeremy Ashkenas, DocumentCloud Inc.
-//     (c) 2011-2013 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
+//     (c) 2010-2014 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
 //     Backbone may be freely distributed under the MIT license.
 //     For all details and documentation:
 //     http://backbonejs.org
 
-(function(){
+(function(root, factory) {
+
+  // Set up Backbone appropriately for the environment. Start with AMD.
+  if (typeof define === 'function' && define.amd) {
+    define(['underscore', 'jquery', 'exports'], function(_, $, exports) {
+      // Export global even in AMD case in case this script is loaded with
+      // others that may still expect a global Backbone.
+      root.Backbone = factory(root, exports, _, $);
+    });
+
+  // Next for Node.js or CommonJS. jQuery may not be needed as a module.
+  } else if (typeof exports !== 'undefined') {
+    var _ = require('underscore'), $;
+    try { $ = require('jquery'); } catch(e) {}
+    factory(root, exports, _, $);
+
+  // Finally, as a browser global.
+  } else {
+    root.Backbone = factory(root, {}, root._, (root.jQuery || root.Zepto || root.ender || root.$));
+  }
+
+}(this, function(root, Backbone, _, $) {
 
   // Initial Setup
   // -------------
 
-  // Save a reference to the global object (`window` in the browser, `exports`
-  // on the server).
-  var root = this;
-
   // Save the previous value of the `Backbone` variable, so that it can be
   // restored later on, if `noConflict` is used.
   var previousBackbone = root.Backbone;
@@ -25,25 +41,12 @@
   var slice = array.slice;
   var splice = array.splice;
 
-  // The top-level namespace. All public Backbone classes and modules will
-  // be attached to this. Exported for both the browser and the server.
-  var Backbone;
-  if (typeof exports !== 'undefined') {
-    Backbone = exports;
-  } else {
-    Backbone = root.Backbone = {};
-  }
-
   // Current version of the library. Keep in sync with `package.json`.
-  Backbone.VERSION = '1.1.0';
-
-  // Require Underscore, if we're on the server, and it's not already present.
-  var _ = root._;
-  if (!_ && (typeof require !== 'undefined')) _ = require('underscore');
+  Backbone.VERSION = '1.1.1';
 
   // For Backbone's purposes, jQuery, Zepto, Ender, or My Library (kidding) owns
   // the `$` variable.
-  Backbone.$ = root.jQuery || root.Zepto || root.ender || root.$;
+  Backbone.$ = $;
 
   // Runs Backbone.js in *noConflict* mode, returning the `Backbone` variable
   // to its previous owner. Returns a reference to this Backbone object.
@@ -109,7 +112,7 @@
       var retain, ev, events, names, i, l, j, k;
       if (!this._events || !eventsApi(this, 'off', name, [callback, context])) return this;
       if (!name && !callback && !context) {
-        this._events = {};
+        this._events = void 0;
         return this;
       }
       names = name ? [name] : _.keys(this._events);
@@ -205,7 +208,7 @@
       case 1: while (++i < l) (ev = events[i]).callback.call(ev.ctx, a1); return;
       case 2: while (++i < l) (ev = events[i]).callback.call(ev.ctx, a1, a2); return;
       case 3: while (++i < l) (ev = events[i]).callback.call(ev.ctx, a1, a2, a3); return;
-      default: while (++i < l) (ev = events[i]).callback.apply(ev.ctx, args);
+      default: while (++i < l) (ev = events[i]).callback.apply(ev.ctx, args); return;
     }
   };
 
@@ -350,7 +353,7 @@
 
       // Trigger all relevant attribute changes.
       if (!silent) {
-        if (changes.length) this._pending = true;
+        if (changes.length) this._pending = options;
         for (var i = 0, l = changes.length; i < l; i++) {
           this.trigger('change:' + changes[i], this, current[changes[i]], options);
         }
@@ -361,6 +364,7 @@
       if (changing) return this;
       if (!silent) {
         while (this._pending) {
+          options = this._pending;
           this._pending = false;
           this.trigger('change', this, options);
         }
@@ -528,9 +532,12 @@
     // using Backbone's restful methods, override this to change the endpoint
     // that will be called.
     url: function() {
-      var base = _.result(this, 'urlRoot') || _.result(this.collection, 'url') || urlError();
+      var base =
+        _.result(this, 'urlRoot') ||
+        _.result(this.collection, 'url') ||
+        urlError();
       if (this.isNew()) return base;
-      return base + (base.charAt(base.length - 1) === '/' ? '' : '/') + encodeURIComponent(this.id);
+      return base.replace(/([^\/])$/, '$1/') + encodeURIComponent(this.id);
     },
 
     // **parse** converts a response into the hash of attributes to be `set` on
@@ -546,7 +553,7 @@
 
     // A model is new if it has never been saved to the server, and lacks an id.
     isNew: function() {
-      return this.id == null;
+      return !this.has(this.idAttribute);
     },
 
     // Check if the model is currently in a valid state.
@@ -650,7 +657,7 @@
           options.index = index;
           model.trigger('remove', model, this, options);
         }
-        this._removeReference(model);
+        this._removeReference(model, options);
       }
       return singular ? models[0] : models;
     },
@@ -676,11 +683,11 @@
       // Turn bare objects into model references, and prevent invalid models
       // from being added.
       for (i = 0, l = models.length; i < l; i++) {
-        attrs = models[i];
+        attrs = models[i] || {};
         if (attrs instanceof Model) {
           id = model = attrs;
         } else {
-          id = attrs[targetModel.prototype.idAttribute];
+          id = attrs[targetModel.prototype.idAttribute || 'id'];
         }
 
         // If a duplicate is found, prevent it from being added and
@@ -700,14 +707,13 @@
           model = models[i] = this._prepareModel(attrs, options);
           if (!model) continue;
           toAdd.push(model);
-
-          // Listen to added models' events, and index models for lookup by
-          // `id` and by `cid`.
-          model.on('all', this._onModelEvent, this);
-          this._byId[model.cid] = model;
-          if (model.id != null) this._byId[model.id] = model;
+          this._addReference(model, options);
         }
-        if (order) order.push(existing || model);
+
+        // Do not add multiple models with the same `id`.
+        model = existing || model;
+        if (order && (model.isNew() || !modelMap[model.id])) order.push(model);
+        modelMap[model.id] = true;
       }
 
       // Remove nonexistent models if appropriate.
@@ -757,7 +763,7 @@
     reset: function(models, options) {
       options || (options = {});
       for (var i = 0, l = this.models.length; i < l; i++) {
-        this._removeReference(this.models[i]);
+        this._removeReference(this.models[i], options);
       }
       options.previousModels = this.models;
       this._reset();
@@ -798,7 +804,7 @@
     // Get a model from the set by id.
     get: function(obj) {
       if (obj == null) return void 0;
-      return this._byId[obj.id] || this._byId[obj.cid] || this._byId[obj];
+      return this._byId[obj] || this._byId[obj.id] || this._byId[obj.cid];
     },
 
     // Get the model at the given index.
@@ -874,7 +880,7 @@
       if (!options.wait) this.add(model, options);
       var collection = this;
       var success = options.success;
-      options.success = function(model, resp, options) {
+      options.success = function(model, resp) {
         if (options.wait) collection.add(model, options);
         if (success) success(model, resp, options);
       };
@@ -904,10 +910,7 @@
     // Prepare a hash of attributes (or other model) to be added to this
     // collection.
     _prepareModel: function(attrs, options) {
-      if (attrs instanceof Model) {
-        if (!attrs.collection) attrs.collection = this;
-        return attrs;
-      }
+      if (attrs instanceof Model) return attrs;
       options = options ? _.clone(options) : {};
       options.collection = this;
       var model = new this.model(attrs, options);
@@ -916,8 +919,16 @@
       return false;
     },
 
+    // Internal method to create a model's ties to a collection.
+    _addReference: function(model, options) {
+      this._byId[model.cid] = model;
+      if (model.id != null) this._byId[model.id] = model;
+      if (!model.collection) model.collection = this;
+      model.on('all', this._onModelEvent, this);
+    },
+
     // Internal method to sever a model's ties to a collection.
-    _removeReference: function(model) {
+    _removeReference: function(model, options) {
       if (this === model.collection) delete model.collection;
       model.off('all', this._onModelEvent, this);
     },
@@ -946,7 +957,7 @@
     'reject', 'every', 'all', 'some', 'any', 'include', 'contains', 'invoke',
     'max', 'min', 'toArray', 'size', 'first', 'head', 'take', 'initial', 'rest',
     'tail', 'drop', 'last', 'without', 'difference', 'indexOf', 'shuffle',
-    'lastIndexOf', 'isEmpty', 'chain'];
+    'lastIndexOf', 'isEmpty', 'chain', 'sample'];
 
   // Mix in each Underscore method as a proxy to `Collection#models`.
   _.each(methods, function(method) {
@@ -958,7 +969,7 @@
   });
 
   // Underscore methods that take a property name as an argument.
-  var attributeMethods = ['groupBy', 'countBy', 'sortBy'];
+  var attributeMethods = ['groupBy', 'countBy', 'sortBy', 'indexBy'];
 
   // Use attributes instead of properties.
   _.each(attributeMethods, function(method) {
@@ -1180,7 +1191,9 @@
     return xhr;
   };
 
-  var noXhrPatch = typeof window !== 'undefined' && !!window.ActiveXObject && !(window.XMLHttpRequest && (new XMLHttpRequest).dispatchEvent);
+  var noXhrPatch =
+    typeof window !== 'undefined' && !!window.ActiveXObject &&
+      !(window.XMLHttpRequest && (new XMLHttpRequest).dispatchEvent);
 
   // Map from CRUD to HTTP for our default `Backbone.sync` implementation.
   var methodMap = {
@@ -1239,7 +1252,7 @@
       var router = this;
       Backbone.history.route(route, function(fragment) {
         var args = router._extractParameters(route, fragment);
-        callback && callback.apply(router, args);
+        router.execute(callback, args);
         router.trigger.apply(router, ['route:' + name].concat(args));
         router.trigger('route', name, args);
         Backbone.history.trigger('route', router, name, args);
@@ -1247,6 +1260,12 @@
       return this;
     },
 
+    // Execute a route handler with the provided parameters.  This is an
+    // excellent place to do pre-route setup or post-route cleanup.
+    execute: function(callback, args) {
+      if (callback) callback.apply(this, args);
+    },
+
     // Simple proxy to `Backbone.history` to save a fragment into the history.
     navigate: function(fragment, options) {
       Backbone.history.navigate(fragment, options);
@@ -1271,10 +1290,10 @@
       route = route.replace(escapeRegExp, '\\$&')
                    .replace(optionalParam, '(?:$1)?')
                    .replace(namedParam, function(match, optional) {
-                     return optional ? match : '([^\/]+)';
+                     return optional ? match : '([^/?]+)';
                    })
-                   .replace(splatParam, '(.*?)');
-      return new RegExp('^' + route + '$');
+                   .replace(splatParam, '([^?]*?)');
+      return new RegExp('^' + route + '(?:\\?(.*))?$');
     },
 
     // Given a route, and a URL fragment that it matches, return the array of
@@ -1282,7 +1301,9 @@
     // treated as `null` to normalize cross-browser behavior.
     _extractParameters: function(route, fragment) {
       var params = route.exec(fragment).slice(1);
-      return _.map(params, function(param) {
+      return _.map(params, function(param, i) {
+        // Don't decode the search params.
+        if (i === params.length - 1) return param || null;
         return param ? decodeURIComponent(param) : null;
       });
     }
@@ -1320,8 +1341,8 @@
   // Cached regex for removing a trailing slash.
   var trailingSlash = /\/$/;
 
-  // Cached regex for stripping urls of hash and query.
-  var pathStripper = /[?#].*$/;
+  // Cached regex for stripping urls of hash.
+  var pathStripper = /#.*$/;
 
   // Has the history handling already been started?
   History.started = false;
@@ -1333,6 +1354,11 @@
     // twenty times a second.
     interval: 50,
 
+    // Are we at the app root?
+    atRoot: function() {
+      return this.location.pathname.replace(/[^\/]$/, '$&/') === this.root;
+    },
+
     // Gets the true hash value. Cannot use location.hash directly due to bug
     // in Firefox where location.hash will always be decoded.
     getHash: function(window) {
@@ -1345,7 +1371,7 @@
     getFragment: function(fragment, forcePushState) {
       if (fragment == null) {
         if (this._hasPushState || !this._wantsHashChange || forcePushState) {
-          fragment = this.location.pathname;
+          fragment = decodeURI(this.location.pathname + this.location.search);
           var root = this.root.replace(trailingSlash, '');
           if (!fragment.indexOf(root)) fragment = fragment.slice(root.length);
         } else {
@@ -1376,7 +1402,8 @@
       this.root = ('/' + this.root + '/').replace(rootStripper, '/');
 
       if (oldIE && this._wantsHashChange) {
-        this.iframe = Backbone.$('<iframe src="javascript:0" tabindex="-1" />').hide().appendTo('body')[0].contentWindow;
+        var frame = Backbone.$('<iframe src="javascript:0" tabindex="-1">');
+        this.iframe = frame.hide().appendTo('body')[0].contentWindow;
         this.navigate(fragment);
       }
 
@@ -1394,7 +1421,6 @@
       // opened by a non-pushState browser.
       this.fragment = fragment;
       var loc = this.location;
-      var atRoot = loc.pathname.replace(/[^\/]$/, '$&/') === this.root;
 
       // Transition from hashChange to pushState or vice versa if both are
       // requested.
@@ -1402,17 +1428,17 @@
 
         // If we've started off with a route from a `pushState`-enabled
         // browser, but we're currently in a browser that doesn't support it...
-        if (!this._hasPushState && !atRoot) {
+        if (!this._hasPushState && !this.atRoot()) {
           this.fragment = this.getFragment(null, true);
-          this.location.replace(this.root + this.location.search + '#' + this.fragment);
+          this.location.replace(this.root + '#' + this.fragment);
           // Return immediately as browser will do redirect to new url
           return true;
 
         // Or if we've started out with a hash-based route, but we're currently
         // in a browser where it could be `pushState`-based instead...
-        } else if (this._hasPushState && atRoot && loc.hash) {
+        } else if (this._hasPushState && this.atRoot() && loc.hash) {
           this.fragment = this.getHash().replace(routeStripper, '');
-          this.history.replaceState({}, document.title, this.root + this.fragment + loc.search);
+          this.history.replaceState({}, document.title, this.root + this.fragment);
         }
 
       }
@@ -1472,7 +1498,7 @@
 
       var url = this.root + (fragment = this.getFragment(fragment || ''));
 
-      // Strip the fragment of the query and hash for matching.
+      // Strip the hash for matching.
       fragment = fragment.replace(pathStripper, '');
 
       if (this.fragment === fragment) return;
@@ -1578,4 +1604,6 @@
     };
   };
 
-}).call(this);
+  return Backbone;
+
+}));

architecture-examples/backbone/bower_components/underscore/underscore.js

-//     Underscore.js 1.5.2
+//     Underscore.js 1.6.0
 //     http://underscorejs.org
-//     (c) 2009-2013 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
+//     (c) 2009-2014 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
 //     Underscore may be freely distributed under the MIT license.
 
 (function() {
@@ -65,7 +65,7 @@
   }
 
   // Current version.
-  _.VERSION = '1.5.2';
+  _.VERSION = '1.6.0';
 
   // Collection Functions
   // --------------------
@@ -74,7 +74,7 @@
   // Handles objects with the built-in `forEach`, arrays, and raw objects.
   // Delegates to **ECMAScript 5**'s native `forEach` if available.
   var each = _.each = _.forEach = function(obj, iterator, context) {
-    if (obj == null) return;
+    if (obj == null) return obj;
     if (nativeForEach && obj.forEach === nativeForEach) {
       obj.forEach(iterator, context);
     } else if (obj.length === +obj.length) {
@@ -87,6 +87,7 @@
         if (iterator.call(context, obj[keys[i]], keys[i], obj) === breaker) return;
       }
     }
+    return obj;
   };
 
   // Return the results of applying the iterator to each element.
@@ -152,10 +153,10 @@
   };
 
   // Return the first value which passes a truth test. Aliased as `detect`.
-  _.find = _.detect = function(obj, iterator, context) {
+  _.find = _.detect = function(obj, predicate, context) {
     var result;
     any(obj, function(value, index, list) {
-      if (iterator.call(context, value, index, list)) {
+      if (predicate.call(context, value, index, list)) {
         result = value;
         return true;
       }
@@ -166,33 +167,33 @@
   // Return all the elements that pass a truth test.
   // Delegates to **ECMAScript 5**'s native `filter` if available.
   // Aliased as `select`.
-  _.filter = _.select = function(obj, iterator, context) {
+  _.filter = _.select = function(obj, predicate, context) {
     var results = [];
     if (obj == null) return results;
-    if (nativeFilter && obj.filter === nativeFilter) return obj.filter(iterator, context);
+    if (nativeFilter && obj.filter === nativeFilter) return obj.filter(predicate, context);
     each(obj, function(value, index, list) {
-      if (iterator.call(context, value, index, list)) results.push(value);
+      if (predicate.call(context, value, index, list)) results.push(value);
     });
     return results;
   };
 
   // Return all the elements for which a truth test fails.
-  _.reject = function(obj, iterator, context) {
+  _.reject = function(obj, predicate, context) {
     return _.filter(obj, function(value, index, list) {
-      return !iterator.call(context, value, index, list);
+      return !predicate.call(context, value, index, list);
     }, context);
   };
 
   // Determine whether all of the elements match a truth test.
   // Delegates to **ECMAScript 5**'s native `every` if available.
   // Aliased as `all`.
-  _.every = _.all = function(obj, iterator, context) {
-    iterator || (iterator = _.identity);
+  _.every = _.all = function(obj, predicate, context) {
+    predicate || (predicate = _.identity);
     var result = true;
     if (obj == null) return result;
-    if (nativeEvery && obj.every === nativeEvery) return obj.every(iterator, context);
+    if (nativeEvery && obj.every === nativeEvery) return obj.every(predicate, context);
     each(obj, function(value, index, list) {
-      if (!(result = result && iterator.call(context, value, index, list))) return breaker;
+      if (!(result = result && predicate.call(context, value, index, list))) return breaker;
     });
     return !!result;
   };
@@ -200,13 +201,13 @@
   // Determine if at least one element in the object matches a truth test.
   // Delegates to **ECMAScript 5**'s native `some` if available.
   // Aliased as `any`.
-  var any = _.some = _.any = function(obj, iterator, context) {
-    iterator || (iterator = _.identity);
+  var any = _.some = _.any = function(obj, predicate, context) {
+    predicate || (predicate = _.identity);
     var result = false;
     if (obj == null) return result;
-    if (nativeSome && obj.some === nativeSome) return obj.some(iterator, context);
+    if (nativeSome && obj.some === nativeSome) return obj.some(predicate, context);
     each(obj, function(value, index, list) {
-      if (result || (result = iterator.call(context, value, index, list))) return breaker;
+      if (result || (result = predicate.call(context, value, index, list))) return breaker;
     });
     return !!result;
   };
@@ -232,25 +233,19 @@
 
   // Convenience version of a common use case of `map`: fetching a property.
   _.pluck = function(obj, key) {
-    return _.map(obj, function(value){ return value[key]; });
+    return _.map(obj, _.property(key));
   };
 
   // Convenience version of a common use case of `filter`: selecting only objects
   // containing specific `key:value` pairs.
-  _.where = function(obj, attrs, first) {
-    if (_.isEmpty(attrs)) return first ? void 0 : [];
-    return _[first ? 'find' : 'filter'](obj, function(value) {
-      for (var key in attrs) {
-        if (attrs[key] !== value[key]) return false;
-      }
-      return true;
-    });
+  _.where = function(obj, attrs) {
+    return _.filter(obj, _.matches(attrs));
   };
 
   // Convenience version of a common use case of `find`: getting the first object
   // containing specific `key:value` pairs.
   _.findWhere = function(obj, attrs) {
-    return _.where(obj, attrs, true);
+    return _.find(obj, _.matches(attrs));
   };
 
   // Return the maximum element or (element-based computation).
@@ -260,13 +255,15 @@
     if (!iterator && _.isArray(obj) && obj[0] === +obj[0] && obj.length < 65535) {
       return Math.max.apply(Math, obj);
     }
-    if (!iterator && _.isEmpty(obj)) return -Infinity;
-    var result = {computed : -Infinity, value: -Infinity};
+    var result = -Infinity, lastComputed = -Infinity;
     each(obj, function(value, index, list) {
       var computed = iterator ? iterator.call(context, value, index, list) : value;
-      computed > result.computed && (result = {value : value, computed : computed});
+      if (computed > lastComputed) {
+        result = value;
+        lastComputed = computed;
+      }
     });
-    return result.value;
+    return result;
   };
 
   // Return the minimum element (or element-based computation).
@@ -274,13 +271,15 @@
     if (!iterator && _.isArray(obj) && obj[0] === +obj[0] && obj.length < 65535) {
       return Math.min.apply(Math, obj);
     }
-    if (!iterator && _.isEmpty(obj)) return Infinity;
-    var result = {computed : Infinity, value: Infinity};
+    var result = Infinity, lastComputed = Infinity;
     each(obj, function(value, index, list) {
       var computed = iterator ? iterator.call(context, value, index, list) : value;
-      computed < result.computed && (result = {value : value, computed : computed});
+      if (computed < lastComputed) {
+        result = value;
+        lastComputed = computed;
+      }
     });
-    return result.value;
+    return result;
   };
 
   // Shuffle an array, using the modern version of the
@@ -297,11 +296,12 @@
     return shuffled;
   };
 
-  // Sample **n** random values from an array.
-  // If **n** is not specified, returns a single random element from the array.
+  // Sample **n** random values from a collection.
+  // If **n** is not specified, returns a single random element.
   // The internal `guard` argument allows it to work with `map`.
   _.sample = function(obj, n, guard) {
-    if (arguments.length < 2 || guard) {
+    if (n == null || guard) {
+      if (obj.length !== +obj.length) obj = _.values(obj);
       return obj[_.random(obj.length - 1)];
     }
     return _.shuffle(obj).slice(0, Math.max(0, n));
@@ -309,12 +309,14 @@
 
   // An internal function to generate lookup iterators.
   var lookupIterator = function(value) {
-    return _.isFunction(value) ? value : function(obj){ return obj[value]; };
+    if (value == null) return _.identity;
+    if (_.isFunction(value)) return value;
+    return _.property(value);
   };
 
   // Sort the object's values by a criterion produced by an iterator.
-  _.sortBy = function(obj, value, context) {
-    var iterator = lookupIterator(value);
+  _.sortBy = function(obj, iterator, context) {
+    iterator = lookupIterator(iterator);
     return _.pluck(_.map(obj, function(value, index, list) {
       return {
         value: value,
@@ -334,9 +336,9 @@
 
   // An internal function used for aggregate "group by" operations.
   var group = function(behavior) {
-    return function(obj, value, context) {
+    return function(obj, iterator, context) {
       var result = {};
-      var iterator = value == null ? _.identity : lookupIterator(value);
+      iterator = lookupIterator(iterator);
       each(obj, function(value, index) {
         var key = iterator.call(context, value, index, obj);
         behavior(result, key, value);
@@ -348,7 +350,7 @@
   // Groups the object's values by a criterion. Pass either a string attribute
   // to group by, or a function that returns the criterion.
   _.groupBy = group(function(result, key, value) {
-    (_.has(result, key) ? result[key] : (result[key] = [])).push(value);
+    _.has(result, key) ? result[key].push(value) : result[key] = [value];
   });
 
   // Indexes the object's values by a criterion, similar to `groupBy`, but for
@@ -367,7 +369,7 @@
   // Use a comparator function to figure out the smallest index at which
   // an object should be inserted so as to maintain order. Uses binary search.
   _.sortedIndex = function(array, obj, iterator, context) {
-    iterator = iterator == null ? _.identity : lookupIterator(iterator);
+    iterator = lookupIterator(iterator);
     var value = iterator.call(context, obj);
     var low = 0, high = array.length;
     while (low < high) {
@@ -399,7 +401,9 @@
   // allows it to work with `_.map`.
   _.first = _.head = _.take = function(array, n, guard) {
     if (array == null) return void 0;
-    return (n == null) || guard ? array[0] : slice.call(array, 0, n);
+    if ((n == null) || guard) return array[0];
+    if (n < 0) return [];
+    return slice.call(array, 0, n);
   };
 
   // Returns everything but the last entry of the array. Especially useful on
@@ -414,11 +418,8 @@
   // values in the array. The **guard** check allows it to work with `_.map`.
   _.last = function(array, n, guard) {
     if (array == null) return void 0;
-    if ((n == null) || guard) {
-      return array[array.length - 1];
-    } else {
+    if ((n == null) || guard) return array[array.length - 1];
     return slice.call(array, Math.max(array.length - n, 0));
-    }
   };
 
   // Returns everything but the first entry of the array. Aliased as `tail` and `drop`.
@@ -459,6 +460,16 @@
     return _.difference(array, slice.call(arguments, 1));
   };
 
+  // Split an array into two arrays: one whose elements all satisfy the given
+  // predicate, and one whose elements all do not satisfy the predicate.
+  _.partition = function(array, predicate) {
+    var pass = [], fail = [];
+    each(array, function(elem) {
+      (predicate(elem) ? pass : fail).push(elem);
+    });
+    return [pass, fail];
+  };
+
   // Produce a duplicate-free version of the array. If the array has already
   // been sorted, you have the option of using a faster algorithm.
   // Aliased as `unique`.
@@ -492,7 +503,7 @@
     var rest = slice.call(arguments, 1);
     return _.filter(_.uniq(array), function(item) {
       return _.every(rest, function(other) {
-        return _.indexOf(other, item) >= 0;
+        return _.contains(other, item);
       });
     });
   };
@@ -507,7 +518,7 @@
   // Zip together multiple lists into a single array -- elements that share
   // an index go together.
   _.zip = function() {
-    var length = _.max(_.pluck(arguments, "length").concat(0));
+    var length = _.max(_.pluck(arguments, 'length').concat(0));
     var results = new Array(length);
     for (var i = 0; i < length; i++) {
       results[i] = _.pluck(arguments, '' + i);
@@ -613,19 +624,27 @@
   };
 
   // Partially apply a function by creating a version that has had some of its
-  // arguments pre-filled, without changing its dynamic `this` context.
+  // arguments pre-filled, without changing its dynamic `this` context. _ acts
+  // as a placeholder, allowing any combination of arguments to be pre-filled.
   _.partial = function(func) {
-    var args = slice.call(arguments, 1);
+    var boundArgs = slice.call(arguments, 1);
     return function() {
-      return func.apply(this, args.concat(slice.call(arguments)));
+      var position = 0;
+      var args = boundArgs.slice();
+      for (var i = 0, length = args.length; i < length; i++) {
+        if (args[i] === _) args[i] = arguments[position++];
+      }
+      while (position < arguments.length) args.push(arguments[position++]);
+      return func.apply(this, args);
     };
   };
 
-  // Bind all of an object's methods to that object. Useful for ensuring that
-  // all callbacks defined on an object belong to it.
+  // Bind a number of an object's methods to that object. Remaining arguments
+  // are the method names to be bound. Useful for ensuring that all callbacks
+  // defined on an object belong to it.
   _.bindAll = function(obj) {
     var funcs = slice.call(arguments, 1);
-    if (funcs.length === 0) throw new Error("bindAll must be passed function names");
+    if (funcs.length === 0) throw new Error('bindAll must be passed function names');
     each(funcs, function(f) { obj[f] = _.bind(obj[f], obj); });
     return obj;
   };
@@ -664,12 +683,13 @@
     var previous = 0;
     options || (options = {});
     var later = function() {
-      previous = options.leading === false ? 0 : new Date;
+      previous = options.leading === false ? 0 : _.now();
       timeout = null;
       result = func.apply(context, args);
+      context = args = null;
     };
     return function() {
-      var now = new Date;
+      var now = _.now();
       if (!previous && options.leading === false) previous = now;
       var remaining = wait - (now - previous);
       context = this;
@@ -679,6 +699,7 @@
         timeout = null;
         previous = now;
         result = func.apply(context, args);
+        context = args = null;
       } else if (!timeout && options.trailing !== false) {
         timeout = setTimeout(later, remaining);
       }
@@ -692,24 +713,33 @@
   // leading edge, instead of the trailing.
   _.debounce = function(func, wait, immediate) {
     var timeout, args, context, timestamp, result;
-    return function() {
-      context = this;
-      args = arguments;
-      timestamp = new Date();
+
     var later = function() {
-        var last = (new Date()) - timestamp;
+      var last = _.now() - timestamp;
       if (last < wait) {
         timeout = setTimeout(later, wait - last);
       } else {
         timeout = null;
-          if (!immediate) result = func.apply(context, args);
+        if (!immediate) {
+          result = func.apply(context, args);
+          context = args = null;
+        }
       }
     };
+
+    return function() {
+      context = this;
+      args = arguments;
+      timestamp = _.now();
       var callNow = immediate && !timeout;
       if (!timeout) {
         timeout = setTimeout(later, wait);
       }
-      if (callNow) result = func.apply(context, args);
+      if (callNow) {
+        result = func.apply(context, args);
+        context = args = null;
+      }
+
       return result;
     };
   };
@@ -731,11 +761,7 @@
   // allowing you to adjust arguments, run code before and after, and
   // conditionally execute the original function.
   _.wrap = function(func, wrapper) {
-    return function() {
-      var args = [func];
-      push.apply(args, arguments);
-      return wrapper.apply(this, args);
-    };
+    return _.partial(wrapper, func);
   };
 
   // Returns a function that is the composition of a list of functions, each
@@ -765,8 +791,9 @@
 
   // Retrieve the names of an object's properties.
   // Delegates to **ECMAScript 5**'s native `Object.keys`
-  _.keys = nativeKeys || function(obj) {
-    if (obj !== Object(obj)) throw new TypeError('Invalid object');
+  _.keys = function(obj) {
+    if (!_.isObject(obj)) return [];
+    if (nativeKeys) return nativeKeys(obj);
     var keys = [];
     for (var key in obj) if (_.has(obj, key)) keys.push(key);
     return keys;
@@ -921,7 +948,8 @@
     // from different frames are.
     var aCtor = a.constructor, bCtor = b.constructor;
     if (aCtor !== bCtor && !(_.isFunction(aCtor) && (aCtor instanceof aCtor) &&
-                             _.isFunction(bCtor) && (bCtor instanceof bCtor))) {
+                             _.isFunction(bCtor) && (bCtor instanceof bCtor))
+                        && ('constructor' in a && 'constructor' in b)) {
       return false;
     }
     // Add the first object to the stack of traversed objects.
@@ -1061,6 +1089,30 @@
     return value;
   };
 
+  _.constant = function(value) {
+    return function () {
+      return value;
+    };
+  };
+
+  _.property = function(key) {
+    return function(obj) {
+      return obj[key];
+    };
+  };
+
+  // Returns a predicate for checking whether an object has a given set of `key:value` pairs.
+  _.matches = function(attrs) {
+    return function(obj) {
+      if (obj === attrs) return true; //avoid comparing an object to itself.
+      for (var key in attrs) {
+        if (attrs[key] !== obj[key])
+          return false;
+      }
+      return true;
+    }
+  };
+
   // Run a function **n** times.
   _.times = function(n, iterator, context) {
     var accum = Array(Math.max(0, n));
@@ -1077,6 +1129,9 @@
     return min + Math.floor(Math.random() * (max - min + 1));
   };
 
+  // A (possibly faster) way to get the current timestamp as an integer.
+  _.now = Date.now || function() { return new Date().getTime(); };
+
   // List of HTML entities for escaping.
   var entityMap = {
     escape: {
@@ -1273,4 +1328,16 @@
 
   });
 
+  // AMD registration happens at the end for compatibility with AMD loaders
+  // that may not enforce next-turn semantics on modules. Even though general
+  // practice for AMD registration is to be anonymous, underscore registers
+  // as a named module because, like jQuery, it is a base library that is
+  // popular enough to be bundled in a third party lib, but not be part of
+  // an AMD load request. Those cases could generate an error when an
+  // anonymous define() is called outside of a loader request.
+  if (typeof define === 'function' && define.amd) {
+    define('underscore', [], function() {
+      return _;
+    });
+  }
 }).call(this);