update lodash

1 files changed, 3012 insertions, 2211 deletions

diff --git a/src/fauxton/assets/js/libs/lodash.js b/src/fauxton/assets/js/libs/lodash.js
index 43ddcb208..ccf632d5e 100644
--- a/src/fauxton/assets/js/libs/lodash.js
+++ b/src/fauxton/assets/js/libs/lodash.js
@@ -1,77 +1,77 @@
-/*!
- * Lo-Dash v0.3.1 <http://lodash.com>
- * Copyright 2012 John-David Dalton <http://allyoucanleet.com/>
- * Based on Underscore.js 1.3.3, copyright 2009-2012 Jeremy Ashkenas, DocumentCloud Inc.
- * <http://documentcloud.github.com/underscore>
+/**
+ * @license
+ * Lo-Dash 1.1.1 (Custom Build) <http://lodash.com/>
+ * Build: `lodash underscore exports="amd,commonjs,global,node" -o ./dist/lodash.underscore.js`
+ * Copyright 2012-2013 The Dojo Foundation <http://dojofoundation.org/>
+ * Based on Underscore.js 1.4.4 <http://underscorejs.org/>
+ * Copyright 2009-2013 Jeremy Ashkenas, DocumentCloud Inc.
  * Available under MIT license <http://lodash.com/license>
  */
-;(function(window, undefined) {
-  'use strict';
+;(function(window) {
+
+  /** Used as a safe reference for `undefined` in pre ES5 environments */
+  var undefined;
 
   /** Detect free variable `exports` */
-  var freeExports = typeof exports == 'object' && exports &&
-    (typeof global == 'object' && global && global == global.global && (window = global), exports);
+  var freeExports = typeof exports == 'object' && exports;
 
-  /**
-   * Detect the JScript [[DontEnum]] bug:
-   * In IE < 9 an objects own properties, shadowing non-enumerable ones, are
-   * made non-enumerable as well.
-   */
-  var hasDontEnumBug = !{ 'valueOf': 0 }.propertyIsEnumerable('valueOf');
+  /** Detect free variable `module` */
+  var freeModule = typeof module == 'object' && module && module.exports == freeExports && module;
+
+  /** Detect free variable `global` and use it as `window` */
+  var freeGlobal = typeof global == 'object' && global;
+  if (freeGlobal.global === freeGlobal) {
+    window = freeGlobal;
+  }
 
   /** Used to generate unique IDs */
   var idCounter = 0;
 
-  /** Used to restore the original `_` reference in `noConflict` */
-  var oldDash = window._;
+  /** Used internally to indicate various things */
+  var indicatorObject = {};
 
-  /** Used to detect if a method is native */
-  var reNative = RegExp('^' + ({}.valueOf + '')
-    .replace(/[.*+?^=!:${}()|[\]\/\\]/g, '\\$&')
-    .replace(/valueOf|for [^\]]+/g, '.+?') + '$');
+  /** Used to match empty string literals in compiled template source */
+  var reEmptyStringLeading = /\b__p \+= '';/g,
+      reEmptyStringMiddle = /\b(__p \+=) '' \+/g,
+      reEmptyStringTrailing = /(__e\(.*?\)|\b__t\)) \+\n'';/g;
 
-  /** Used to match tokens in template text */
-  var reToken = /__token__(\d+)/g;
+  /** Used to match HTML entities */
+  var reEscapedHtml = /&(?:amp|lt|gt|quot|#39);/g;
 
-  /** Used to match unescaped characters in HTML */
-  var reUnescapedHtml = /[&<"']/g;
+  /**
+   * Used to match ES6 template delimiters
+   * http://people.mozilla.org/~jorendorff/es6-draft.html#sec-7.8.6
+   */
+  var reEsTemplate = /\$\{([^\\}]*(?:\\.[^\\}]*)*)\}/g;
 
-  /** Used to match unescaped characters in compiled string literals */
-  var reUnescapedString = /['\n\r\t\u2028\u2029\\]/g;
+  /** Used to match regexp flags from their coerced string values */
+  var reFlags = /\w*$/;
 
-  /** Used to fix the JScript [[DontEnum]] bug */
-  var shadowed = [
-    'constructor', 'hasOwnProperty', 'isPrototypeOf', 'propertyIsEnumerable',
-    'toLocaleString', 'toString', 'valueOf'
-  ];
+  /** Used to match "interpolate" template delimiters */
+  var reInterpolate = /<%=([\s\S]+?)%>/g;
 
-  /** Used to make template sourceURLs easier to identify */
-  var templateCounter = 0;
+  /** Used to ensure capturing order of template delimiters */
+  var reNoMatch = /($^)/;
 
-  /** Used to replace template delimiters */
-  var token = '__token__';
+  /** Used to match HTML characters */
+  var reUnescapedHtml = /[&<>"']/g;
 
-  /** Used to store tokenized template text snippets */
-  var tokenized = [];
+  /** Used to match unescaped characters in compiled string literals */
+  var reUnescapedString = /['\n\r\t\u2028\u2029\\]/g;
 
-  /** Detect if sourceURL syntax is usable without erroring */
-  try {
-    // Adobe's and Narwhal's JS engines will error
-    var useSourceURL = (Function('//@')(), true);
-  } catch(e){ }
+  /** Used to make template sourceURLs easier to identify */
+  var templateCounter = 0;
 
-  /**
-   * Used to escape characters for inclusion in HTML.
-   * The `>` and `/` characters don't require escaping in HTML and have no
-   * special meaning unless they're part of a tag or an unquoted attribute value
-   * http://mathiasbynens.be/notes/ambiguous-ampersands (semi-related fun fact)
-   */
-  var htmlEscapes = {
-    '&': '&amp;',
-    '<': '&lt;',
-    '"': '&quot;',
-    "'": '&#x27;'
-  };
+  /** `Object#toString` result shortcuts */
+  var argsClass = '[object Arguments]',
+      arrayClass = '[object Array]',
+      boolClass = '[object Boolean]',
+      dateClass = '[object Date]',
+      funcClass = '[object Function]',
+      numberClass = '[object Number]',
+      objectClass = '[object Object]',
+      regexpClass = '[object RegExp]',
+      stringClass = '[object String]';
 
   /** Used to determine if values are of the language type Object */
   var objectTypes = {
@@ -94,72 +94,142 @@
     '\u2029': 'u2029'
   };
 
-  /** Object#toString result shortcuts */
-  var arrayClass = '[object Array]',
-      boolClass = '[object Boolean]',
-      dateClass = '[object Date]',
-      funcClass = '[object Function]',
-      numberClass = '[object Number]',
-      regexpClass = '[object RegExp]',
-      stringClass = '[object String]';
+  /*--------------------------------------------------------------------------*/
 
-  /** Native prototype shortcuts */
-  var ArrayProto = Array.prototype,
-      ObjectProto = Object.prototype;
+  /** Used for `Array` and `Object` method references */
+  var arrayRef = Array(),
+      objectRef = Object();
 
-  /** Native method shortcuts */
-  var concat = ArrayProto.concat,
-      hasOwnProperty = ObjectProto.hasOwnProperty,
-      push = ArrayProto.push,
-      slice = ArrayProto.slice,
-      toString = ObjectProto.toString;
+  /** Used to restore the original `_` reference in `noConflict` */
+  var oldDash = window._;
+
+  /** Used to detect if a method is native */
+  var reNative = RegExp('^' +
+    String(objectRef.valueOf)
+      .replace(/[.*+?^${}()|[\]\\]/g, '\\$&')
+      .replace(/valueOf|for [^\]]+/g, '.+?') + '$'
+  );
 
-  /* Used if `Function#bind` exists and is inferred to be fast (i.e. all but V8) */
-  var nativeBind = reNative.test(nativeBind = slice.bind) &&
-    /\n|Opera/.test(nativeBind + toString.call(window.opera)) && nativeBind;
+  /** Native method shortcuts */
+  var ceil = Math.ceil,
+      clearTimeout = window.clearTimeout,
+      concat = arrayRef.concat,
+      floor = Math.floor,
+      hasOwnProperty = objectRef.hasOwnProperty,
+      push = arrayRef.push,
+      setTimeout = window.setTimeout,
+      slice = arrayRef.slice,
+      toString = objectRef.toString;
 
   /* Native method shortcuts for methods with the same name as other `lodash` methods */
-  var nativeIsArray = reNative.test(nativeIsArray = Array.isArray) && nativeIsArray,
+  var nativeBind = reNative.test(nativeBind = slice.bind) && nativeBind,
+      nativeIsArray = reNative.test(nativeIsArray = Array.isArray) && nativeIsArray,
       nativeIsFinite = window.isFinite,
-      nativeKeys = reNative.test(nativeKeys = Object.keys) && nativeKeys;
+      nativeIsNaN = window.isNaN,
+      nativeKeys = reNative.test(nativeKeys = Object.keys) && nativeKeys,
+      nativeMax = Math.max,
+      nativeMin = Math.min,
+      nativeRandom = Math.random;
 
-  /** Timer shortcuts */
-  var clearTimeout = window.clearTimeout,
-      setTimeout = window.setTimeout;
+  /** Detect various environments */
+  var isIeOpera = reNative.test(window.attachEvent),
+      isV8 = nativeBind && !/\n|true/.test(nativeBind + isIeOpera);
 
   /*--------------------------------------------------------------------------*/
 
   /**
-   * The `lodash` function.
+   * Creates a `lodash` object, that wraps the given `value`, to enable method
+   * chaining.
+   *
+   * In addition to Lo-Dash methods, wrappers also have the following `Array` methods:
+   * `concat`, `join`, `pop`, `push`, `reverse`, `shift`, `slice`, `sort`, `splice`,
+   * and `unshift`
+   *
+   * Chaining is supported in custom builds as long as the `value` method is
+   * implicitly or explicitly included in the build.
+   *
+   * The chainable wrapper functions are:
+   * `after`, `assign`, `bind`, `bindAll`, `bindKey`, `chain`, `compact`,
+   * `compose`, `concat`, `countBy`, `createCallback`, `debounce`, `defaults`,
+   * `defer`, `delay`, `difference`, `filter`, `flatten`, `forEach`, `forIn`,
+   * `forOwn`, `functions`, `groupBy`, `initial`, `intersection`, `invert`,
+   * `invoke`, `keys`, `map`, `max`, `memoize`, `merge`, `min`, `object`, `omit`,
+   * `once`, `pairs`, `partial`, `partialRight`, `pick`, `pluck`, `push`, `range`,
+   * `reject`, `rest`, `reverse`, `shuffle`, `slice`, `sort`, `sortBy`, `splice`,
+   * `tap`, `throttle`, `times`, `toArray`, `union`, `uniq`, `unshift`, `values`,
+   * `where`, `without`, `wrap`, and `zip`
+   *
+   * The non-chainable wrapper functions are:
+   * `clone`, `cloneDeep`, `contains`, `escape`, `every`, `find`, `has`,
+   * `identity`, `indexOf`, `isArguments`, `isArray`, `isBoolean`, `isDate`,
+   * `isElement`, `isEmpty`, `isEqual`, `isFinite`, `isFunction`, `isNaN`,
+   * `isNull`, `isNumber`, `isObject`, `isPlainObject`, `isRegExp`, `isString`,
+   * `isUndefined`, `join`, `lastIndexOf`, `mixin`, `noConflict`, `parseInt`,
+   * `pop`, `random`, `reduce`, `reduceRight`, `result`, `shift`, `size`, `some`,
+   * `sortedIndex`, `runInContext`, `template`, `unescape`, `uniqueId`, and `value`
+   *
+   * The wrapper functions `first` and `last` return wrapped values when `n` is
+   * passed, otherwise they return unwrapped values.
    *
    * @name _
    * @constructor
-   * @param {Mixed} value The value to wrap in a `LoDash` instance.
-   * @returns {Object} Returns a `LoDash` instance.
+   * @category Chaining
+   * @param {Mixed} value The value to wrap in a `lodash` instance.
+   * @returns {Object} Returns a `lodash` instance.
    */
   function lodash(value) {
-    // allow invoking `lodash` without the `new` operator
-    return new LoDash(value);
+    return (value instanceof lodash)
+      ? value
+      : new lodashWrapper(value);
   }
 
   /**
-   * Creates a `LoDash` instance that wraps a value to allow chaining.
+   * An object used to flag environments features.
    *
-   * @private
-   * @constructor
-   * @param {Mixed} value The value to wrap.
+   * @static
+   * @memberOf _
+   * @type Object
    */
-  function LoDash(value) {
-    // exit early if already wrapped
-    if (value && value._wrapped) {
-      return value;
-    }
-    this._wrapped = value;
-  }
+  var support = {};
+
+  (function() {
+    var object = { '0': 1, 'length': 1 };
+
+    /**
+     * Detect if `arguments` objects are `Object` objects (all but Opera < 10.5).
+     *
+     * @memberOf _.support
+     * @type Boolean
+     */
+    support.argsObject = arguments.constructor == Object;
+
+    /**
+     * Detect if `Function#bind` exists and is inferred to be fast (all but V8).
+     *
+     * @memberOf _.support
+     * @type Boolean
+     */
+    support.fastBind = nativeBind && !isV8;
+
+    /**
+     * Detect if `Array#shift` and `Array#splice` augment array-like objects correctly.
+     *
+     * Firefox < 10, IE compatibility mode, and IE < 9 have buggy Array `shift()`
+     * and `splice()` functions that fail to remove the last element, `value[0]`,
+     * of array-like objects even though the `length` property is set to `0`.
+     * The `shift()` method is buggy in IE 8 compatibility mode, while `splice()`
+     * is buggy regardless of mode in IE < 9 and buggy in compatibility mode in IE 9.
+     *
+     * @memberOf _.support
+     * @type Boolean
+     */
+    support.spliceObjects = (arrayRef.splice.call(object, 0, 1), !object[0]);
+  }(1));
 
   /**
-   * By default, Lo-Dash uses ERB-style template delimiters, change the
-   * following template settings to use alternative delimiters.
+   * By default, the template delimiters used by Lo-Dash are similar to those in
+   * embedded Ruby (ERB). Change the following template settings to use alternative
+   * delimiters.
    *
    * @static
    * @memberOf _
@@ -170,7 +240,6 @@
     /**
      * Used to detect `data` property values to be HTML-escaped.
      *
-     * @static
      * @memberOf _.templateSettings
      * @type RegExp
      */
@@ -179,7 +248,6 @@
     /**
      * Used to detect code to be evaluated.
      *
-     * @static
      * @memberOf _.templateSettings
      * @type RegExp
      */
@@ -188,510 +256,1545 @@
     /**
      * Used to detect `data` property values to inject.
      *
-     * @static
      * @memberOf _.templateSettings
      * @type RegExp
      */
-    'interpolate': /<%=([\s\S]+?)%>/g,
+    'interpolate': reInterpolate,
 
     /**
      * Used to reference the data object in the template text.
      *
-     * @static
      * @memberOf _.templateSettings
      * @type String
      */
-    'variable': 'obj'
+    'variable': ''
   };
 
   /*--------------------------------------------------------------------------*/
 
   /**
-   * The template used to create iterator functions.
+   * Used by `_.max` and `_.min` as the default `callback` when a given
+   * `collection` is a string value.
    *
    * @private
-   * @param {Obect} data The data object used to populate the text.
-   * @returns {String} Returns the interpolated text.
-   */
-  var iteratorTemplate = template(
-    // assign the `result` variable an initial value
-    'var index, result<% if (init) { %> = <%= init %><% } %>;\n' +
-    // add code to exit early or do so if the first argument is falsey
-    '<%= exit %>;\n' +
-    // add code after the exit snippet but before the iteration branches
-    '<%= top %>;\n' +
-
-    // the following branch is for iterating arrays and array-like objects
-    '<% if (arrayBranch) { %>' +
-    'var length = <%= firstArg %>.length; index = -1;' +
-    '  <% if (objectBranch) { %>\nif (length === length >>> 0) {<% } %>\n' +
-    '  <%= arrayBranch.beforeLoop %>;\n' +
-    '  while (<%= arrayBranch.loopExp %>) {\n' +
-    '    <%= arrayBranch.inLoop %>;\n' +
-    '  }' +
-    '  <% if (objectBranch) { %>\n}\n<% }' +
-    '}' +
-
-    // the following branch is for iterating an object's own/inherited properties
-    'if (objectBranch) {' +
-    '  if (arrayBranch) { %>else {\n<% }' +
-    '  if (!hasDontEnumBug) { %>  var skipProto = typeof <%= iteratedObject %> == \'function\';\n<% } %>' +
-    '  <%= objectBranch.beforeLoop %>;\n' +
-    '  for (<%= objectBranch.loopExp %>) {' +
-    '  \n<%' +
-    '  if (hasDontEnumBug) {' +
-    '    if (useHas) { %>    if (<%= hasExp %>) {\n  <% } %>' +
-    '    <%= objectBranch.inLoop %>;<%' +
-    '    if (useHas) { %>\n    }<% }' +
-    '  }' +
-    '  else {' +
-    '  %>' +
-
-    // Firefox < 3.6, Opera > 9.50 - Opera < 11.60, and Safari < 5.1
-    // (if the prototype or a property on the prototype has been set)
-    // incorrectly sets a function's `prototype` property [[Enumerable]]
-    // value to `true`. Because of this Lo-Dash standardizes on skipping
-    // the the `prototype` property of functions regardless of its
-    // [[Enumerable]] value.
-    '    if (!(skipProto && index == \'prototype\')<% if (useHas) { %> && <%= hasExp %><% } %>) {\n' +
-    '      <%= objectBranch.inLoop %>;\n' +
-    '    }' +
-    '  <% } %>\n' +
-    '  }' +
-
-    // Because IE < 9 can't set the `[[Enumerable]]` attribute of an
-    // existing property and the `constructor` property of a prototype
-    // defaults to non-enumerable, Lo-Dash skips the `constructor`
-    // property when it infers it's iterating over a `prototype` object.
-    '  <% if (hasDontEnumBug) { %>\n' +
-    '  var ctor = <%= iteratedObject %>.constructor;\n' +
-    '  <% for (var k = 0; k < 7; k++) { %>\n' +
-    '  index = \'<%= shadowed[k] %>\';\n' +
-    '  if (<%' +
-    '      if (shadowed[k] == \'constructor\') {' +
-    '        %>!(ctor && ctor.prototype === <%= iteratedObject %>) && <%' +
-    '      } %><%= hasExp %>) {\n' +
-    '    <%= objectBranch.inLoop %>;\n' +
-    '  }<%' +
-    '     }' +
-    '   }' +
-    '   if (arrayBranch) { %>\n}<% }' +
-    '} %>\n' +
-
-    // add code to the bottom of the iteration function
-    '<%= bottom %>;\n' +
-    // finally, return the `result`
-    'return result'
-  );
+   * @param {String} value The character to inspect.
+   * @returns {Number} Returns the code unit of given character.
+   */
+  function charAtCallback(value) {
+    return value.charCodeAt(0);
+  }
 
   /**
-   * Reusable iterator options shared by
-   * `every`, `filter`, `find`, `forEach`, `forIn`, `forOwn`, `map`, `reject`, and `some`.
-   */
-  var baseIteratorOptions = {
-    'args': 'collection, callback, thisArg',
-    'init': 'collection',
-    'top':
-      'if (!callback) {\n' +
-      '  callback = identity\n' +
-      '}\n' +
-      'else if (thisArg) {\n' +
-      '  callback = iteratorBind(callback, thisArg)\n' +
-      '}',
-    'inLoop': 'callback(collection[index], index, collection)'
-  };
+   * Used by `sortBy` to compare transformed `collection` values, stable sorting
+   * them in ascending order.
+   *
+   * @private
+   * @param {Object} a The object to compare to `b`.
+   * @param {Object} b The object to compare to `a`.
+   * @returns {Number} Returns the sort order indicator of `1` or `-1`.
+   */
+  function compareAscending(a, b) {
+    var ai = a.index,
+        bi = b.index;
 
-  /** Reusable iterator options for `every` and `some` */
-  var everyIteratorOptions = {
-    'init': 'true',
-    'inLoop': 'if (!callback(collection[index], index, collection)) return !result'
-  };
+    a = a.criteria;
+    b = b.criteria;
 
-  /** Reusable iterator options for `defaults` and `extend` */
-  var extendIteratorOptions = {
-    'args': 'object',
-    'init': 'object',
-    'top':
-      'for (var source, sourceIndex = 1, length = arguments.length; sourceIndex < length; sourceIndex++) {\n' +
-      '  source = arguments[sourceIndex];\n' +
-      (hasDontEnumBug ? '  if (source) {' : ''),
-    'loopExp': 'index in source',
-    'useHas': false,
-    'inLoop': 'object[index] = source[index]',
-    'bottom': (hasDontEnumBug ? '  }\n' : '') + '}'
-  };
+    // ensure a stable sort in V8 and other engines
+    // http://code.google.com/p/v8/issues/detail?id=90
+    if (a !== b) {
+      if (a > b || typeof a == 'undefined') {
+        return 1;
+      }
+      if (a < b || typeof b == 'undefined') {
+        return -1;
+      }
+    }
+    return ai < bi ? -1 : 1;
+  }
+
+  /**
+   * Creates a function that, when called, invokes `func` with the `this` binding
+   * of `thisArg` and prepends any `partialArgs` to the arguments passed to the
+   * bound function.
+   *
+   * @private
+   * @param {Function|String} func The function to bind or the method name.
+   * @param {Mixed} [thisArg] The `this` binding of `func`.
+   * @param {Array} partialArgs An array of arguments to be partially applied.
+   * @param {Object} [idicator] Used to indicate binding by key or partially
+   *  applying arguments from the right.
+   * @returns {Function} Returns the new bound function.
+   */
+  function createBound(func, thisArg, partialArgs, indicator) {
+    var isFunc = isFunction(func),
+        isPartial = !partialArgs,
+        key = thisArg;
+
+    // juggle arguments
+    if (isPartial) {
+      var rightIndicator = indicator;
+      partialArgs = thisArg;
+    }
+    else if (!isFunc) {
+      if (!indicator) {
+        throw new TypeError;
+      }
+      thisArg = func;
+    }
+
+    function bound() {
+      // `Function#bind` spec
+      // http://es5.github.com/#x15.3.4.5
+      var args = arguments,
+          thisBinding = isPartial ? this : thisArg;
+
+      if (!isFunc) {
+        func = thisArg[key];
+      }
+      if (partialArgs.length) {
+        args = args.length
+          ? (args = slice.call(args), rightIndicator ? args.concat(partialArgs) : partialArgs.concat(args))
+          : partialArgs;
+      }
+      if (this instanceof bound) {
+        // ensure `new bound` is an instance of `func`
+        noop.prototype = func.prototype;
+        thisBinding = new noop;
+        noop.prototype = null;
+
+        // mimic the constructor's `return` behavior
+        // http://es5.github.com/#x13.2.2
+        var result = func.apply(thisBinding, args);
+        return isObject(result) ? result : thisBinding;
+      }
+      return func.apply(thisBinding, args);
+    }
+    return bound;
+  }
+
+  /**
+   * Used by `template` to escape characters for inclusion in compiled
+   * string literals.
+   *
+   * @private
+   * @param {String} match The matched character to escape.
+   * @returns {String} Returns the escaped character.
+   */
+  function escapeStringChar(match) {
+    return '\\' + stringEscapes[match];
+  }
+
+  /**
+   * Used by `escape` to convert characters to HTML entities.
+   *
+   * @private
+   * @param {String} match The matched character to escape.
+   * @returns {String} Returns the escaped character.
+   */
+  function escapeHtmlChar(match) {
+    return htmlEscapes[match];
+  }
+
+  /**
+   * A fast path for creating `lodash` wrapper objects.
+   *
+   * @private
+   * @param {Mixed} value The value to wrap in a `lodash` instance.
+   * @returns {Object} Returns a `lodash` instance.
+   */
+  function lodashWrapper(value) {
+    this.__wrapped__ = value;
+  }
+  // ensure `new lodashWrapper` is an instance of `lodash`
+  lodashWrapper.prototype = lodash.prototype;
 
-  /** Reusable iterator options for `filter` and `reject` */
-  var filterIteratorOptions = {
-    'init': '[]',
-    'inLoop': 'callback(collection[index], index, collection) && result.push(collection[index])'
+  /**
+   * A no-operation function.
+   *
+   * @private
+   */
+  function noop() {
+    // no operation performed
+  }
+
+  /**
+   * Used by `unescape` to convert HTML entities to characters.
+   *
+   * @private
+   * @param {String} match The matched character to unescape.
+   * @returns {String} Returns the unescaped character.
+   */
+  function unescapeHtmlChar(match) {
+    return htmlUnescapes[match];
+  }
+
+  /*--------------------------------------------------------------------------*/
+
+  /**
+   * Checks if `value` is an `arguments` object.
+   *
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Mixed} value The value to check.
+   * @returns {Boolean} Returns `true`, if the `value` is an `arguments` object, else `false`.
+   * @example
+   *
+   * (function() { return _.isArguments(arguments); })(1, 2, 3);
+   * // => true
+   *
+   * _.isArguments([1, 2, 3]);
+   * // => false
+   */
+  function isArguments(value) {
+    return toString.call(value) == argsClass;
+  }
+  // fallback for browsers that can't detect `arguments` objects by [[Class]]
+  if (!isArguments(arguments)) {
+    isArguments = function(value) {
+      return value ? hasOwnProperty.call(value, 'callee') : false;
+    };
+  }
+
+  /**
+   * Checks if `value` is an array.
+   *
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Mixed} value The value to check.
+   * @returns {Boolean} Returns `true`, if the `value` is an array, else `false`.
+   * @example
+   *
+   * (function() { return _.isArray(arguments); })();
+   * // => false
+   *
+   * _.isArray([1, 2, 3]);
+   * // => true
+   */
+  var isArray = nativeIsArray || function(value) {
+    // `instanceof` may cause a memory leak in IE 7 if `value` is a host object
+    // http://ajaxian.com/archives/working-aroung-the-instanceof-memory-leak
+    return (support.argsObject && value instanceof Array) || toString.call(value) == arrayClass;
   };
 
-  /** Reusable iterator options for `find`, `forEach`, `forIn`, and `forOwn` */
-  var forEachIteratorOptions = {
-    'top': 'if (thisArg) callback = iteratorBind(callback, thisArg)'
+  /**
+   * A fallback implementation of `Object.keys` that produces an array of the
+   * given object's own enumerable property names.
+   *
+   * @private
+   * @type Function
+   * @param {Object} object The object to inspect.
+   * @returns {Array} Returns a new array of property names.
+   */
+  var shimKeys = function (object) {
+    var index, iterable = object, result = [];
+    if (!iterable) return result;
+    if (!(objectTypes[typeof object])) return result;
+
+      for (index in iterable) {
+        if (hasOwnProperty.call(iterable, index)) {    
+        result.push(index);    
+        }
+      }  
+    return result
   };
 
-  /** Reusable iterator options for `forIn` and `forOwn` */
-  var forOwnIteratorOptions = {
-    'inLoop': {
-      'object': baseIteratorOptions.inLoop
+  /**
+   * Creates an array composed of the own enumerable property names of `object`.
+   *
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Object} object The object to inspect.
+   * @returns {Array} Returns a new array of property names.
+   * @example
+   *
+   * _.keys({ 'one': 1, 'two': 2, 'three': 3 });
+   * // => ['one', 'two', 'three'] (order is not guaranteed)
+   */
+  var keys = !nativeKeys ? shimKeys : function(object) {
+    if (!isObject(object)) {
+      return [];
     }
+    return nativeKeys(object);
   };
 
+  /**
+   * Used to convert characters to HTML entities:
+   *
+   * Though the `>` character is escaped for symmetry, characters like `>` and `/`
+   * don't require escaping in HTML and have no special meaning unless they're part
+   * of a tag or an unquoted attribute value.
+   * http://mathiasbynens.be/notes/ambiguous-ampersands (under "semi-related fun fact")
+   */
+  var htmlEscapes = {
+    '&': '&amp;',
+    '<': '&lt;',
+    '>': '&gt;',
+    '"': '&quot;',
+    "'": '&#39;'
+  };
+
+  /** Used to convert HTML entities to characters */
+  var htmlUnescapes = invert(htmlEscapes);
+
   /*--------------------------------------------------------------------------*/
 
   /**
-   * Creates compiled iteration functions. The iteration function will be created
-   * to iterate over only objects if the first argument of `options.args` is
-   * "object" or `options.inLoop.array` is falsey.
+   * Assigns own enumerable properties of source object(s) to the destination
+   * object. Subsequent sources will overwrite property assignments of previous
+   * sources. If a `callback` function is passed, it will be executed to produce
+   * the assigned values. The `callback` is bound to `thisArg` and invoked with
+   * two arguments; (objectValue, sourceValue).
    *
-   * @private
-   * @param {Object} [options1, options2, ...] The compile options objects.
-   *
-   *  args - A string of comma separated arguments the iteration function will
-   *   accept.
+   * @static
+   * @memberOf _
+   * @type Function
+   * @alias extend
+   * @category Objects
+   * @param {Object} object The destination object.
+   * @param {Object} [source1, source2, ...] The source objects.
+   * @param {Function} [callback] The function to customize assigning values.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Object} Returns the destination object.
+   * @example
    *
-   *  init - A string to specify the initial value of the `result` variable.
+   * _.assign({ 'name': 'moe' }, { 'age': 40 });
+   * // => { 'name': 'moe', 'age': 40 }
    *
-   *  exit - A string of code to use in place of the default exit-early check
-   *   of `if (!arguments[0]) return result`.
+   * var defaults = _.partialRight(_.assign, function(a, b) {
+   *   return typeof a == 'undefined' ? b : a;
+   * });
    *
-   *  top - A string of code to execute after the exit-early check but before
-   *   the iteration branches.
+   * var food = { 'name': 'apple' };
+   * defaults(food, { 'name': 'banana', 'type': 'fruit' });
+   * // => { 'name': 'apple', 'type': 'fruit' }
+   */
+  function assign(object) {
+    if (!object) {
+      return object;
+    }
+    for (var argsIndex = 1, argsLength = arguments.length; argsIndex < argsLength; argsIndex++) {
+      var iterable = arguments[argsIndex];
+      if (iterable) {
+        for (var key in iterable) {
+          object[key] = iterable[key];
+        }
+      }
+    }
+    return object;
+  }
+
+  /**
+   * Creates a clone of `value`. If `deep` is `true`, nested objects will also
+   * be cloned, otherwise they will be assigned by reference. If a `callback`
+   * function is passed, it will be executed to produce the cloned values. If
+   * `callback` returns `undefined`, cloning will be handled by the method instead.
+   * The `callback` is bound to `thisArg` and invoked with one argument; (value).
    *
-   *  beforeLoop - A string or object containing an "array" or "object" property
-   *   of code to execute before the array or object loops.
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Mixed} value The value to clone.
+   * @param {Boolean} [deep=false] A flag to indicate a deep clone.
+   * @param {Function} [callback] The function to customize cloning values.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @param- {Array} [stackA=[]] Tracks traversed source objects.
+   * @param- {Array} [stackB=[]] Associates clones with source counterparts.
+   * @returns {Mixed} Returns the cloned `value`.
+   * @example
    *
-   *  loopExp - A string or object containing an "array" or "object" property
-   *   of code to execute as the array or object loop expression.
+   * var stooges = [
+   *   { 'name': 'moe', 'age': 40 },
+   *   { 'name': 'larry', 'age': 50 }
+   * ];
    *
-   *  useHas - A boolean to specify whether or not to use `hasOwnProperty` checks
-   *   in the object loop.
+   * var shallow = _.clone(stooges);
+   * shallow[0] === stooges[0];
+   * // => true
    *
-   *  inLoop - A string or object containing an "array" or "object" property
-   *   of code to execute in the array or object loops.
+   * var deep = _.clone(stooges, true);
+   * deep[0] === stooges[0];
+   * // => false
    *
-   *  bottom - A string of code to execute after the iteration branches but
-   *   before the `result` is returned.
+   * _.mixin({
+   *   'clone': _.partialRight(_.clone, function(value) {
+   *     return _.isElement(value) ? value.cloneNode(false) : undefined;
+   *   })
+   * });
    *
-   * @returns {Function} Returns the compiled function.
+   * var clone = _.clone(document.body);
+   * clone.childNodes.length;
+   * // => 0
    */
-  function createIterator() {
-    var object,
-        prop,
-        value,
-        index = -1,
-        length = arguments.length;
-
-    // merge options into a template data object
-    var data = {
-      'bottom': '',
-      'exit': '',
-      'init': '',
-      'top': '',
-      'arrayBranch': { 'beforeLoop': '', 'loopExp': '++index < length' },
-      'objectBranch': { 'beforeLoop': '' }
-    };
+  function clone(value) {
+    return isObject(value)
+      ? (isArray(value) ? slice.call(value) : assign({}, value))
+      : value;
+  }
 
-    while (++index < length) {
-      object = arguments[index];
-      for (prop in object) {
-        value = (value = object[prop]) == null ? '' : value;
-        // keep this regexp explicit for the build pre-process
-        if (/beforeLoop|loopExp|inLoop/.test(prop)) {
-          if (typeof value == 'string') {
-            value = { 'array': value, 'object': value };
+  /**
+   * Assigns own enumerable properties of source object(s) to the destination
+   * object for all destination properties that resolve to `undefined`. Once a
+   * property is set, additional defaults of the same property will be ignored.
+   *
+   * @static
+   * @memberOf _
+   * @type Function
+   * @category Objects
+   * @param {Object} object The destination object.
+   * @param {Object} [source1, source2, ...] The source objects.
+   * @param- {Object} [guard] Allows working with `_.reduce` without using its
+   *  callback's `key` and `object` arguments as sources.
+   * @returns {Object} Returns the destination object.
+   * @example
+   *
+   * var food = { 'name': 'apple' };
+   * _.defaults(food, { 'name': 'banana', 'type': 'fruit' });
+   * // => { 'name': 'apple', 'type': 'fruit' }
+   */
+  function defaults(object) {
+    if (!object) {
+      return object;
+    }
+    for (var argsIndex = 1, argsLength = arguments.length; argsIndex < argsLength; argsIndex++) {
+      var iterable = arguments[argsIndex];
+      if (iterable) {
+        for (var key in iterable) {
+          if (object[key] == null) {
+            object[key] = iterable[key];
           }
-          data.arrayBranch[prop] = value.array;
-          data.objectBranch[prop] = value.object;
-        } else {
-          data[prop] = value;
         }
       }
     }
-    // set additional template data values
-    var args = data.args,
-        arrayBranch = data.arrayBranch,
-        objectBranch = data.objectBranch,
-        firstArg = /^[^,]+/.exec(args)[0],
-        loopExp = objectBranch.loopExp,
-        iteratedObject = /\S+$/.exec(loopExp || firstArg)[0];
+    return object;
+  }
+
+  /**
+   * Iterates over `object`'s own and inherited enumerable properties, executing
+   * the `callback` for each property. The `callback` is bound to `thisArg` and
+   * invoked with three arguments; (value, key, object). Callbacks may exit iteration
+   * early by explicitly returning `false`.
+   *
+   * @static
+   * @memberOf _
+   * @type Function
+   * @category Objects
+   * @param {Object} object The object to iterate over.
+   * @param {Function} [callback=identity] The function called per iteration.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Object} Returns `object`.
+   * @example
+   *
+   * function Dog(name) {
+   *   this.name = name;
+   * }
+   *
+   * Dog.prototype.bark = function() {
+   *   alert('Woof, woof!');
+   * };
+   *
+   * _.forIn(new Dog('Dagny'), function(value, key) {
+   *   alert(key);
+   * });
+   * // => alerts 'name' and 'bark' (order is not guaranteed)
+   */
+  var forIn = function (collection, callback) {
+    var index, iterable = collection, result = iterable;
+    if (!iterable) return result;
+    if (!objectTypes[typeof iterable]) return result;
+
+      for (index in iterable) {
+        if (callback(iterable[index], index, collection) === indicatorObject) return result;    
+      }  
+    return result
+  };
+
+  /**
+   * Iterates over an object's own enumerable properties, executing the `callback`
+   * for each property. The `callback` is bound to `thisArg` and invoked with three
+   * arguments; (value, key, object). Callbacks may exit iteration early by explicitly
+   * returning `false`.
+   *
+   * @static
+   * @memberOf _
+   * @type Function
+   * @category Objects
+   * @param {Object} object The object to iterate over.
+   * @param {Function} [callback=identity] The function called per iteration.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Object} Returns `object`.
+   * @example
+   *
+   * _.forOwn({ '0': 'zero', '1': 'one', 'length': 2 }, function(num, key) {
+   *   alert(key);
+   * });
+   * // => alerts '0', '1', and 'length' (order is not guaranteed)
+   */
+  var forOwn = function (collection, callback) {
+    var index, iterable = collection, result = iterable;
+    if (!iterable) return result;
+    if (!objectTypes[typeof iterable]) return result;
+
+      for (index in iterable) {
+        if (hasOwnProperty.call(iterable, index)) {    
+        if (callback(iterable[index], index, collection) === indicatorObject) return result;    
+        }
+      }  
+    return result
+  };
+
+  /**
+   * Creates a sorted array of all enumerable properties, own and inherited,
+   * of `object` that have function values.
+   *
+   * @static
+   * @memberOf _
+   * @alias methods
+   * @category Objects
+   * @param {Object} object The object to inspect.
+   * @returns {Array} Returns a new array of property names that have function values.
+   * @example
+   *
+   * _.functions(_);
+   * // => ['all', 'any', 'bind', 'bindAll', 'clone', 'compact', 'compose', ...]
+   */
+  function functions(object) {
+    var result = [];
+    forIn(object, function(value, key) {
+      if (isFunction(value)) {
+        result.push(key);
+      }
+    });
+    return result.sort();
+  }
+
+  /**
+   * Checks if the specified object `property` exists and is a direct property,
+   * instead of an inherited property.
+   *
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Object} object The object to check.
+   * @param {String} property The property to check for.
+   * @returns {Boolean} Returns `true` if key is a direct property, else `false`.
+   * @example
+   *
+   * _.has({ 'a': 1, 'b': 2, 'c': 3 }, 'b');
+   * // => true
+   */
+  function has(object, property) {
+    return object ? hasOwnProperty.call(object, property) : false;
+  }
+
+  /**
+   * Creates an object composed of the inverted keys and values of the given `object`.
+   *
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Object} object The object to invert.
+   * @returns {Object} Returns the created inverted object.
+   * @example
+   *
+   *  _.invert({ 'first': 'moe', 'second': 'larry' });
+   * // => { 'moe': 'first', 'larry': 'second' }
+   */
+  function invert(object) {
+    var index = -1,
+        props = keys(object),
+        length = props.length,
+        result = {};
+
+    while (++index < length) {
+      var key = props[index];
+      result[object[key]] = key;
+    }
+    return result;
+  }
+
+  /**
+   * Checks if `value` is a boolean value.
+   *
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Mixed} value The value to check.
+   * @returns {Boolean} Returns `true`, if the `value` is a boolean value, else `false`.
+   * @example
+   *
+   * _.isBoolean(null);
+   * // => false
+   */
+  function isBoolean(value) {
+    return value === true || value === false || toString.call(value) == boolClass;
+  }
+
+  /**
+   * Checks if `value` is a date.
+   *
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Mixed} value The value to check.
+   * @returns {Boolean} Returns `true`, if the `value` is a date, else `false`.
+   * @example
+   *
+   * _.isDate(new Date);
+   * // => true
+   */
+  function isDate(value) {
+    return value instanceof Date || toString.call(value) == dateClass;
+  }
 
-    data.firstArg = firstArg;
-    data.hasDontEnumBug = hasDontEnumBug;
-    data.hasExp = 'hasOwnProperty.call(' + iteratedObject + ', index)';
-    data.iteratedObject = iteratedObject;
-    data.shadowed = shadowed;
-    data.useHas = data.useHas !== false;
+  /**
+   * Checks if `value` is a DOM element.
+   *
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Mixed} value The value to check.
+   * @returns {Boolean} Returns `true`, if the `value` is a DOM element, else `false`.
+   * @example
+   *
+   * _.isElement(document.body);
+   * // => true
+   */
+  function isElement(value) {
+    return value ? value.nodeType === 1 : false;
+  }
 
-    if (!data.exit) {
-      data.exit = 'if (!' + firstArg + ') return result';
+  /**
+   * Checks if `value` is empty. Arrays, strings, or `arguments` objects with a
+   * length of `0` and objects with no own enumerable properties are considered
+   * "empty".
+   *
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Array|Object|String} value The value to inspect.
+   * @returns {Boolean} Returns `true`, if the `value` is empty, else `false`.
+   * @example
+   *
+   * _.isEmpty([1, 2, 3]);
+   * // => false
+   *
+   * _.isEmpty({});
+   * // => true
+   *
+   * _.isEmpty('');
+   * // => true
+   */
+  function isEmpty(value) {
+    if (!value) {
+      return true;
     }
-    if (firstArg == 'object' || !arrayBranch.inLoop) {
-      data.arrayBranch = null;
+    if (isArray(value) || isString(value)) {
+      return !value.length;
     }
-    if (!loopExp) {
-      objectBranch.loopExp = 'index in ' + iteratedObject;
+    for (var key in value) {
+      if (hasOwnProperty.call(value, key)) {
+        return false;
+      }
     }
-    // create the function factory
-    var factory = Function(
-        'arrayClass, funcClass, hasOwnProperty, identity, iteratorBind, objectTypes, ' +
-        'stringClass, toString, undefined',
-      '"use strict"; return function(' + args + ') {\n' + iteratorTemplate(data) + '\n}'
-    );
-    // return the compiled function
-    return factory(
-      arrayClass, funcClass, hasOwnProperty, identity, iteratorBind, objectTypes,
-      stringClass, toString
-    );
+    return true;
   }
 
   /**
-   * Used by `template()` to replace tokens with their corresponding code snippets.
+   * Performs a deep comparison between two values to determine if they are
+   * equivalent to each other. If `callback` is passed, it will be executed to
+   * compare values. If `callback` returns `undefined`, comparisons will be handled
+   * by the method instead. The `callback` is bound to `thisArg` and invoked with
+   * two arguments; (a, b).
    *
-   * @private
-   * @param {String} match The matched token.
-   * @param {String} index The `tokenized` index of the code snippet.
-   * @returns {String} Returns the code snippet.
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Mixed} a The value to compare.
+   * @param {Mixed} b The other value to compare.
+   * @param {Function} [callback] The function to customize comparing values.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @param- {Array} [stackA=[]] Tracks traversed `a` objects.
+   * @param- {Array} [stackB=[]] Tracks traversed `b` objects.
+   * @returns {Boolean} Returns `true`, if the values are equivalent, else `false`.
+   * @example
+   *
+   * var moe = { 'name': 'moe', 'age': 40 };
+   * var copy = { 'name': 'moe', 'age': 40 };
+   *
+   * moe == copy;
+   * // => false
+   *
+   * _.isEqual(moe, copy);
+   * // => true
+   *
+   * var words = ['hello', 'goodbye'];
+   * var otherWords = ['hi', 'goodbye'];
+   *
+   * _.isEqual(words, otherWords, function(a, b) {
+   *   var reGreet = /^(?:hello|hi)$/i,
+   *       aGreet = _.isString(a) && reGreet.test(a),
+   *       bGreet = _.isString(b) && reGreet.test(b);
+   *
+   *   return (aGreet || bGreet) ? (aGreet == bGreet) : undefined;
+   * });
+   * // => true
    */
-  function detokenize(match, index) {
-    return tokenized[index];
+  function isEqual(a, b, stackA, stackB) {
+    if (a === b) {
+      return a !== 0 || (1 / a == 1 / b);
+    }
+    var type = typeof a,
+        otherType = typeof b;
+
+    if (a === a &&
+        (!a || (type != 'function' && type != 'object')) &&
+        (!b || (otherType != 'function' && otherType != 'object'))) {
+      return false;
+    }
+    if (a == null || b == null) {
+      return a === b;
+    }
+    var className = toString.call(a),
+        otherClass = toString.call(b);
+
+    if (className != otherClass) {
+      return false;
+    }
+    switch (className) {
+      case boolClass:
+      case dateClass:
+        return +a == +b;
+
+      case numberClass:
+        return a != +a
+          ? b != +b
+          : (a == 0 ? (1 / a == 1 / b) : a == +b);
+
+      case regexpClass:
+      case stringClass:
+        return a == String(b);
+    }
+    var isArr = className == arrayClass;
+    if (!isArr) {
+      if (a instanceof lodash || b instanceof lodash) {
+        return isEqual(a.__wrapped__ || a, b.__wrapped__ || b, stackA, stackB);
+      }
+      if (className != objectClass) {
+        return false;
+      }
+      var ctorA = a.constructor,
+          ctorB = b.constructor;
+
+      if (ctorA != ctorB && !(
+            isFunction(ctorA) && ctorA instanceof ctorA &&
+            isFunction(ctorB) && ctorB instanceof ctorB
+          )) {
+        return false;
+      }
+    }
+    stackA || (stackA = []);
+    stackB || (stackB = []);
+
+    var length = stackA.length;
+    while (length--) {
+      if (stackA[length] == a) {
+        return stackB[length] == b;
+      }
+    }
+    var result = true,
+        size = 0;
+
+    stackA.push(a);
+    stackB.push(b);
+
+    if (isArr) {
+      size = b.length;
+      result = size == a.length;
+
+      if (result) {
+        while (size--) {
+          if (!(result = isEqual(a[size], b[size], stackA, stackB))) {
+            break;
+          }
+        }
+      }
+      return result;
+    }
+    forIn(b, function(value, key, b) {
+      if (hasOwnProperty.call(b, key)) {
+        size++;
+        return !(result = hasOwnProperty.call(a, key) && isEqual(a[key], value, stackA, stackB)) && indicatorObject;
+      }
+    });
+
+    if (result) {
+      forIn(a, function(value, key, a) {
+        if (hasOwnProperty.call(a, key)) {
+          return !(result = --size > -1) && indicatorObject;
+        }
+      });
+    }
+    return result;
   }
 
   /**
-   * Used by `template()` to escape characters for inclusion in compiled
-   * string literals.
+   * Checks if `value` is, or can be coerced to, a finite number.
    *
-   * @private
-   * @param {String} match The matched character to escape.
-   * @returns {String} Returns the escaped character.
+   * Note: This is not the same as native `isFinite`, which will return true for
+   * booleans and empty strings. See http://es5.github.com/#x15.1.2.5.
+   *
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Mixed} value The value to check.
+   * @returns {Boolean} Returns `true`, if the `value` is finite, else `false`.
+   * @example
+   *
+   * _.isFinite(-101);
+   * // => true
+   *
+   * _.isFinite('10');
+   * // => true
+   *
+   * _.isFinite(true);
+   * // => false
+   *
+   * _.isFinite('');
+   * // => false
+   *
+   * _.isFinite(Infinity);
+   * // => false
    */
-  function escapeStringChar(match) {
-    return '\\' + stringEscapes[match];
+  function isFinite(value) {
+    return nativeIsFinite(value) && !nativeIsNaN(parseFloat(value));
   }
 
   /**
-   * Used by `escape()` to escape characters for inclusion in HTML.
+   * Checks if `value` is a function.
    *
-   * @private
-   * @param {String} match The matched character to escape.
-   * @returns {String} Returns the escaped character.
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Mixed} value The value to check.
+   * @returns {Boolean} Returns `true`, if the `value` is a function, else `false`.
+   * @example
+   *
+   * _.isFunction(_);
+   * // => true
    */
-  function escapeHtmlChar(match) {
-    return htmlEscapes[match];
+  function isFunction(value) {
+    return typeof value == 'function';
+  }
+  // fallback for older versions of Chrome and Safari
+  if (isFunction(/x/)) {
+    isFunction = function(value) {
+      return value instanceof Function || toString.call(value) == funcClass;
+    };
   }
 
   /**
-   * Creates a new function that, when called, invokes `func` with the `this`
-   * binding of `thisArg` and the arguments (value, index, object).
+   * Checks if `value` is the language type of Object.
+   * (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
    *
-   * @private
-   * @param {Function} func The function to bind.
-   * @param {Mixed} [thisArg] The `this` binding of `func`.
-   * @returns {Function} Returns the new bound function.
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Mixed} value The value to check.
+   * @returns {Boolean} Returns `true`, if the `value` is an object, else `false`.
+   * @example
+   *
+   * _.isObject({});
+   * // => true
+   *
+   * _.isObject([1, 2, 3]);
+   * // => true
+   *
+   * _.isObject(1);
+   * // => false
    */
-  function iteratorBind(func, thisArg) {
-    return function(value, index, object) {
-      return func.call(thisArg, value, index, object);
-    };
+  function isObject(value) {
+    // check if the value is the ECMAScript language type of Object
+    // http://es5.github.com/#x8
+    // and avoid a V8 bug
+    // http://code.google.com/p/v8/issues/detail?id=2291
+    return value ? objectTypes[typeof value] : false;
   }
 
   /**
-   * A no-operation function.
+   * Checks if `value` is `NaN`.
    *
-   * @private
+   * Note: This is not the same as native `isNaN`, which will return `true` for
+   * `undefined` and other values. See http://es5.github.com/#x15.1.2.4.
+   *
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Mixed} value The value to check.
+   * @returns {Boolean} Returns `true`, if the `value` is `NaN`, else `false`.
+   * @example
+   *
+   * _.isNaN(NaN);
+   * // => true
+   *
+   * _.isNaN(new Number(NaN));
+   * // => true
+   *
+   * isNaN(undefined);
+   * // => true
+   *
+   * _.isNaN(undefined);
+   * // => false
    */
-  function noop() {
-    // no operation performed
+  function isNaN(value) {
+    // `NaN` as a primitive is the only value that is not equal to itself
+    // (perform the [[Class]] check first to avoid errors with some host objects in IE)
+    return isNumber(value) && value != +value
   }
 
   /**
-   * A shim implementation of `Object.keys` that produces an array of the given
-   * object's own enumerable property names.
+   * Checks if `value` is `null`.
    *
-   * @private
-   * @param {Object} object The object to inspect.
-   * @returns {Array} Returns a new array of property names.
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Mixed} value The value to check.
+   * @returns {Boolean} Returns `true`, if the `value` is `null`, else `false`.
+   * @example
+   *
+   * _.isNull(null);
+   * // => true
+   *
+   * _.isNull(undefined);
+   * // => false
    */
-  var shimKeys = createIterator({
-    'args': 'object',
-    'exit': 'if (!objectTypes[typeof object] || object === null) throw TypeError()',
-    'init': '[]',
-    'inLoop': 'result.push(index)'
-  });
+  function isNull(value) {
+    return value === null;
+  }
 
   /**
-   * Used by `template()` to replace "escape" template delimiters with tokens.
+   * Checks if `value` is a number.
    *
-   * @private
-   * @param {String} match The matched template delimiter.
-   * @param {String} value The delimiter value.
-   * @returns {String} Returns a token.
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Mixed} value The value to check.
+   * @returns {Boolean} Returns `true`, if the `value` is a number, else `false`.
+   * @example
+   *
+   * _.isNumber(8.4 * 5);
+   * // => true
    */
-  function tokenizeEscape(match, value) {
-    var index = tokenized.length;
-    tokenized[index] = "'+\n_.escape(" + value + ") +\n'";
-    return token + index;
+  function isNumber(value) {
+    return typeof value == 'number' || toString.call(value) == numberClass;
   }
 
   /**
-   * Used by `template()` to replace "interpolate" template delimiters with tokens.
+   * Checks if `value` is a regular expression.
    *
-   * @private
-   * @param {String} match The matched template delimiter.
-   * @param {String} value The delimiter value.
-   * @returns {String} Returns a token.
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Mixed} value The value to check.
+   * @returns {Boolean} Returns `true`, if the `value` is a regular expression, else `false`.
+   * @example
+   *
+   * _.isRegExp(/moe/);
+   * // => true
    */
-  function tokenizeInterpolate(match, value) {
-    var index = tokenized.length;
-    tokenized[index] = "'+\n((__t = (" + value + ")) == null ? '' : __t) +\n'";
-    return token + index;
+  function isRegExp(value) {
+    return value instanceof RegExp || toString.call(value) == regexpClass;
   }
 
   /**
-   * Used by `template()` to replace "evaluate" template delimiters with tokens.
+   * Checks if `value` is a string.
    *
-   * @private
-   * @param {String} match The matched template delimiter.
-   * @param {String} value The delimiter value.
-   * @returns {String} Returns a token.
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Mixed} value The value to check.
+   * @returns {Boolean} Returns `true`, if the `value` is a string, else `false`.
+   * @example
+   *
+   * _.isString('moe');
+   * // => true
+   */
+  function isString(value) {
+    return typeof value == 'string' || toString.call(value) == stringClass;
+  }
+
+  /**
+   * Checks if `value` is `undefined`.
+   *
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Mixed} value The value to check.
+   * @returns {Boolean} Returns `true`, if the `value` is `undefined`, else `false`.
+   * @example
+   *
+   * _.isUndefined(void 0);
+   * // => true
+   */
+  function isUndefined(value) {
+    return typeof value == 'undefined';
+  }
+
+  /**
+   * Creates a shallow clone of `object` excluding the specified properties.
+   * Property names may be specified as individual arguments or as arrays of
+   * property names. If a `callback` function is passed, it will be executed
+   * for each property in the `object`, omitting the properties `callback`
+   * returns truthy for. The `callback` is bound to `thisArg` and invoked
+   * with three arguments; (value, key, object).
+   *
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Object} object The source object.
+   * @param {Function|String} callback|[prop1, prop2, ...] The properties to omit
+   *  or the function called per iteration.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Object} Returns an object without the omitted properties.
+   * @example
+   *
+   * _.omit({ 'name': 'moe', 'age': 40 }, 'age');
+   * // => { 'name': 'moe' }
+   *
+   * _.omit({ 'name': 'moe', 'age': 40 }, function(value) {
+   *   return typeof value == 'number';
+   * });
+   * // => { 'name': 'moe' }
+   */
+  function omit(object) {
+    var props = concat.apply(arrayRef, arguments),
+        result = {};
+
+    forIn(object, function(value, key) {
+      if (indexOf(props, key, 1) < 0) {
+        result[key] = value;
+      }
+    });
+    return result;
+  }
+
+  /**
+   * Creates a two dimensional array of the given object's key-value pairs,
+   * i.e. `[[key1, value1], [key2, value2]]`.
+   *
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Object} object The object to inspect.
+   * @returns {Array} Returns new array of key-value pairs.
+   * @example
+   *
+   * _.pairs({ 'moe': 30, 'larry': 40 });
+   * // => [['moe', 30], ['larry', 40]] (order is not guaranteed)
+   */
+  function pairs(object) {
+    var index = -1,
+        props = keys(object),
+        length = props.length,
+        result = Array(length);
+
+    while (++index < length) {
+      var key = props[index];
+      result[index] = [key, object[key]];
+    }
+    return result;
+  }
+
+  /**
+   * Creates a shallow clone of `object` composed of the specified properties.
+   * Property names may be specified as individual arguments or as arrays of property
+   * names. If `callback` is passed, it will be executed for each property in the
+   * `object`, picking the properties `callback` returns truthy for. The `callback`
+   * is bound to `thisArg` and invoked with three arguments; (value, key, object).
+   *
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Object} object The source object.
+   * @param {Array|Function|String} callback|[prop1, prop2, ...] The function called
+   *  per iteration or properties to pick, either as individual arguments or arrays.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Object} Returns an object composed of the picked properties.
+   * @example
+   *
+   * _.pick({ 'name': 'moe', '_userid': 'moe1' }, 'name');
+   * // => { 'name': 'moe' }
+   *
+   * _.pick({ 'name': 'moe', '_userid': 'moe1' }, function(value, key) {
+   *   return key.charAt(0) != '_';
+   * });
+   * // => { 'name': 'moe' }
    */
-  function tokenizeEvaluate(match, value) {
-    var index = tokenized.length;
-    tokenized[index] = "';\n" + value + ";\n__p += '";
-    return token + index;
+  function pick(object) {
+    var index = 0,
+        props = concat.apply(arrayRef, arguments),
+        length = props.length,
+        result = {};
+
+    while (++index < length) {
+      var prop = props[index];
+      if (prop in object) {
+        result[prop] = object[prop];
+      }
+    }
+    return result;
+  }
+
+  /**
+   * Creates an array composed of the own enumerable property values of `object`.
+   *
+   * @static
+   * @memberOf _
+   * @category Objects
+   * @param {Object} object The object to inspect.
+   * @returns {Array} Returns a new array of property values.
+   * @example
+   *
+   * _.values({ 'one': 1, 'two': 2, 'three': 3 });
+   * // => [1, 2, 3] (order is not guaranteed)
+   */
+  function values(object) {
+    var index = -1,
+        props = keys(object),
+        length = props.length,
+        result = Array(length);
+
+    while (++index < length) {
+      result[index] = object[props[index]];
+    }
+    return result;
   }
 
   /*--------------------------------------------------------------------------*/
 
   /**
-   * Checks if a given `target` value is present in a `collection` using strict
-   * equality for comparisons, i.e. `===`.
+   * Checks if a given `target` element is present in a `collection` using strict
+   * equality for comparisons, i.e. `===`. If `fromIndex` is negative, it is used
+   * as the offset from the end of the collection.
    *
    * @static
    * @memberOf _
    * @alias include
    * @category Collections
-   * @param {Array|Object} collection The collection to iterate over.
+   * @param {Array|Object|String} collection The collection to iterate over.
    * @param {Mixed} target The value to check for.
-   * @returns {Boolean} Returns `true` if `target` value is found, else `false`.
+   * @param {Number} [fromIndex=0] The index to search from.
+   * @returns {Boolean} Returns `true` if the `target` element is found, else `false`.
    * @example
    *
-   * _.contains([1, 2, 3], 3);
+   * _.contains([1, 2, 3], 1);
+   * // => true
+   *
+   * _.contains([1, 2, 3], 1, 2);
+   * // => false
+   *
+   * _.contains({ 'name': 'moe', 'age': 40 }, 'moe');
+   * // => true
+   *
+   * _.contains('curly', 'ur');
    * // => true
    */
-  var contains = createIterator({
-    'args': 'collection, target',
-    'init': 'false',
-    'inLoop': 'if (collection[index] === target) return true'
-  });
+  function contains(collection, target) {
+    var length = collection ? collection.length : 0,
+        result = false;
+    if (typeof length == 'number') {
+      result = indexOf(collection, target) > -1;
+    } else {
+      forOwn(collection, function(value) {
+        return (result = value === target) && indicatorObject;
+      });
+    }
+    return result;
+  }
+
+  /**
+   * Creates an object composed of keys returned from running each element of the
+   * `collection` through the given `callback`. The corresponding value of each key
+   * is the number of times the key was returned by the `callback`. The `callback`
+   * is bound to `thisArg` and invoked with three arguments; (value, index|key, collection).
+   *
+   * If a property name is passed for `callback`, the created "_.pluck" style
+   * callback will return the property value of the given element.
+   *
+   * If an object is passed for `callback`, the created "_.where" style callback
+   * will return `true` for elements that have the properties of the given object,
+   * else `false`.
+   *
+   * @static
+   * @memberOf _
+   * @category Collections
+   * @param {Array|Object|String} collection The collection to iterate over.
+   * @param {Function|Object|String} [callback=identity] The function called per
+   *  iteration. If a property name or object is passed, it will be used to create
+   *  a "_.pluck" or "_.where" style callback, respectively.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Object} Returns the composed aggregate object.
+   * @example
+   *
+   * _.countBy([4.3, 6.1, 6.4], function(num) { return Math.floor(num); });
+   * // => { '4': 1, '6': 2 }
+   *
+   * _.countBy([4.3, 6.1, 6.4], function(num) { return this.floor(num); }, Math);
+   * // => { '4': 1, '6': 2 }
+   *
+   * _.countBy(['one', 'two', 'three'], 'length');
+   * // => { '3': 2, '5': 1 }
+   */
+  function countBy(collection, callback, thisArg) {
+    var result = {};
+    callback = createCallback(callback, thisArg);
+
+    forEach(collection, function(value, key, collection) {
+      key = String(callback(value, key, collection));
+      (hasOwnProperty.call(result, key) ? result[key]++ : result[key] = 1);
+    });
+    return result;
+  }
 
   /**
    * Checks if the `callback` returns a truthy value for **all** elements of a
-   * `collection`. The `callback` is bound to `thisArg` and invoked with 3
-   * arguments; for arrays they are (value, index, array) and for objects they
-   * are (value, key, object).
+   * `collection`. The `callback` is bound to `thisArg` and invoked with three
+   * arguments; (value, index|key, collection).
+   *
+   * If a property name is passed for `callback`, the created "_.pluck" style
+   * callback will return the property value of the given element.
+   *
+   * If an object is passed for `callback`, the created "_.where" style callback
+   * will return `true` for elements that have the properties of the given object,
+   * else `false`.
    *
    * @static
    * @memberOf _
    * @alias all
    * @category Collections
-   * @param {Array|Object} collection The collection to iterate over.
-   * @param {Function} [callback=identity] The function called per iteration.
-   * @param {Mixed} [thisArg] The `this` binding for the callback.
-   * @returns {Boolean} Returns `true` if all values pass the callback check, else `false`.
+   * @param {Array|Object|String} collection The collection to iterate over.
+   * @param {Function|Object|String} [callback=identity] The function called per
+   *  iteration. If a property name or object is passed, it will be used to create
+   *  a "_.pluck" or "_.where" style callback, respectively.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Boolean} Returns `true` if all elements pass the callback check,
+   *  else `false`.
    * @example
    *
    * _.every([true, 1, null, 'yes'], Boolean);
    * // => false
+   *
+   * var stooges = [
+   *   { 'name': 'moe', 'age': 40 },
+   *   { 'name': 'larry', 'age': 50 }
+   * ];
+   *
+   * // using "_.pluck" callback shorthand
+   * _.every(stooges, 'age');
+   * // => true
+   *
+   * // using "_.where" callback shorthand
+   * _.every(stooges, { 'age': 50 });
+   * // => false
    */
-  var every = createIterator(baseIteratorOptions, everyIteratorOptions);
+  function every(collection, callback, thisArg) {
+    var result = true;
+    callback = createCallback(callback, thisArg);
+
+    var index = -1,
+        length = collection ? collection.length : 0;
+
+    if (typeof length == 'number') {
+      while (++index < length) {
+        if (!(result = !!callback(collection[index], index, collection))) {
+          break;
+        }
+      }
+    } else {
+      forOwn(collection, function(value, index, collection) {
+        return !(result = !!callback(value, index, collection)) && indicatorObject;
+      });
+    }
+    return result;
+  }
 
   /**
-   * Examines each value in a `collection`, returning an array of all values the
-   * `callback` returns truthy for. The `callback` is bound to `thisArg` and
-   * invoked with 3 arguments; for arrays they are (value, index, array) and for
-   * objects they are (value, key, object).
+   * Examines each element in a `collection`, returning an array of all elements
+   * the `callback` returns truthy for. The `callback` is bound to `thisArg` and
+   * invoked with three arguments; (value, index|key, collection).
+   *
+   * If a property name is passed for `callback`, the created "_.pluck" style
+   * callback will return the property value of the given element.
+   *
+   * If an object is passed for `callback`, the created "_.where" style callback
+   * will return `true` for elements that have the properties of the given object,
+   * else `false`.
    *
    * @static
    * @memberOf _
    * @alias select
    * @category Collections
-   * @param {Array|Object} collection The collection to iterate over.
-   * @param {Function} [callback=identity] The function called per iteration.
-   * @param {Mixed} [thisArg] The `this` binding for the callback.
-   * @returns {Array} Returns a new array of values that passed callback check.
+   * @param {Array|Object|String} collection The collection to iterate over.
+   * @param {Function|Object|String} [callback=identity] The function called per
+   *  iteration. If a property name or object is passed, it will be used to create
+   *  a "_.pluck" or "_.where" style callback, respectively.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Array} Returns a new array of elements that passed the callback check.
    * @example
    *
    * var evens = _.filter([1, 2, 3, 4, 5, 6], function(num) { return num % 2 == 0; });
    * // => [2, 4, 6]
+   *
+   * var food = [
+   *   { 'name': 'apple',  'organic': false, 'type': 'fruit' },
+   *   { 'name': 'carrot', 'organic': true,  'type': 'vegetable' }
+   * ];
+   *
+   * // using "_.pluck" callback shorthand
+   * _.filter(food, 'organic');
+   * // => [{ 'name': 'carrot', 'organic': true, 'type': 'vegetable' }]
+   *
+   * // using "_.where" callback shorthand
+   * _.filter(food, { 'type': 'fruit' });
+   * // => [{ 'name': 'apple', 'organic': false, 'type': 'fruit' }]
    */
-  var filter = createIterator(baseIteratorOptions, filterIteratorOptions);
+  function filter(collection, callback, thisArg) {
+    var result = [];
+    callback = createCallback(callback, thisArg);
+
+    var index = -1,
+        length = collection ? collection.length : 0;
+
+    if (typeof length == 'number') {
+      while (++index < length) {
+        var value = collection[index];
+        if (callback(value, index, collection)) {
+          result.push(value);
+        }
+      }
+    } else {
+      forOwn(collection, function(value, index, collection) {
+        if (callback(value, index, collection)) {
+          result.push(value);
+        }
+      });
+    }
+    return result;
+  }
 
   /**
-   * Examines each value in a `collection`, returning the first one the `callback`
-   * returns truthy for. The function returns as soon as it finds an acceptable
-   * value, and does not iterate over the entire `collection`. The `callback` is
-   * bound to `thisArg` and invoked with 3 arguments; for arrays they are
-   * (value, index, array) and for objects they are (value, key, object).
+   * Examines each element in a `collection`, returning the first that the `callback`
+   * returns truthy for. The `callback` is bound to `thisArg` and invoked with three
+   * arguments; (value, index|key, collection).
+   *
+   * If a property name is passed for `callback`, the created "_.pluck" style
+   * callback will return the property value of the given element.
+   *
+   * If an object is passed for `callback`, the created "_.where" style callback
+   * will return `true` for elements that have the properties of the given object,
+   * else `false`.
    *
    * @static
    * @memberOf _
    * @alias detect
    * @category Collections
-   * @param {Array|Object} collection The collection to iterate over.
-   * @param {Function} callback The function called per iteration.
-   * @param {Mixed} [thisArg] The `this` binding for the callback.
-   * @returns {Mixed} Returns the value that passed the callback check, else `undefined`.
+   * @param {Array|Object|String} collection The collection to iterate over.
+   * @param {Function|Object|String} [callback=identity] The function called per
+   *  iteration. If a property name or object is passed, it will be used to create
+   *  a "_.pluck" or "_.where" style callback, respectively.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Mixed} Returns the found element, else `undefined`.
    * @example
    *
-   * var even = _.find([1, 2, 3, 4, 5, 6], function(num) { return num % 2 == 0; });
+   * _.find([1, 2, 3, 4], function(num) { return num % 2 == 0; });
    * // => 2
+   *
+   * var food = [
+   *   { 'name': 'apple',  'organic': false, 'type': 'fruit' },
+   *   { 'name': 'banana', 'organic': true,  'type': 'fruit' },
+   *   { 'name': 'beet',   'organic': false, 'type': 'vegetable' }
+   * ];
+   *
+   * // using "_.where" callback shorthand
+   * _.find(food, { 'type': 'vegetable' });
+   * // => { 'name': 'beet', 'organic': false, 'type': 'vegetable' }
+   *
+   * // using "_.pluck" callback shorthand
+   * _.find(food, 'organic');
+   * // => { 'name': 'banana', 'organic': true, 'type': 'fruit' }
    */
-  var find = createIterator(baseIteratorOptions, forEachIteratorOptions, {
-    'init': '',
-    'inLoop': 'if (callback(collection[index], index, collection)) return collection[index]'
-  });
+  function find(collection, callback, thisArg) {
+    callback = createCallback(callback, thisArg);
+
+    var index = -1,
+        length = collection ? collection.length : 0;
+
+    if (typeof length == 'number') {
+      while (++index < length) {
+        var value = collection[index];
+        if (callback(value, index, collection)) {
+          return value;
+        }
+      }
+    } else {
+      var result;
+      forOwn(collection, function(value, index, collection) {
+        if (callback(value, index, collection)) {
+          result = value;
+          return indicatorObject;
+        }
+      });
+      return result;
+    }
+  }
+
+  function findWhere(object, properties) {
+    return where(object, properties, true);
+  }
 
   /**
-   * Iterates over a `collection`, executing the `callback` for each value in the
-   * `collection`. The `callback` is bound to `thisArg` and invoked with 3
-   * arguments; for arrays they are (value, index, array) and for objects they
-   * are (value, key, object).
+   * Iterates over a `collection`, executing the `callback` for each element in
+   * the `collection`. The `callback` is bound to `thisArg` and invoked with three
+   * arguments; (value, index|key, collection). Callbacks may exit iteration early
+   * by explicitly returning `false`.
    *
    * @static
    * @memberOf _
    * @alias each
    * @category Collections
-   * @param {Array|Object} collection The collection to iterate over.
-   * @param {Function} callback The function called per iteration.
-   * @param {Mixed} [thisArg] The `this` binding for the callback.
-   * @returns {Array|Object} Returns the `collection`.
+   * @param {Array|Object|String} collection The collection to iterate over.
+   * @param {Function} [callback=identity] The function called per iteration.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Array|Object|String} Returns `collection`.
    * @example
    *
    * _([1, 2, 3]).forEach(alert).join(',');
    * // => alerts each number and returns '1,2,3'
    *
    * _.forEach({ 'one': 1, 'two': 2, 'three': 3 }, alert);
-   * // => alerts each number (order is not guaranteed)
+   * // => alerts each number value (order is not guaranteed)
    */
-  var forEach = createIterator(baseIteratorOptions, forEachIteratorOptions);
+  function forEach(collection, callback, thisArg) {
+    var index = -1,
+        length = collection ? collection.length : 0;
+
+    callback = callback && typeof thisArg == 'undefined' ? callback : createCallback(callback, thisArg);
+    if (typeof length == 'number') {
+      while (++index < length) {
+        if (callback(collection[index], index, collection) === indicatorObject) {
+          break;
+        }
+      }
+    } else {
+      forOwn(collection, callback);
+    };
+  }
+
+  /**
+   * Creates an object composed of keys returned from running each element of the
+   * `collection` through the `callback`. The corresponding value of each key is
+   * an array of elements passed to `callback` that returned the key. The `callback`
+   * is bound to `thisArg` and invoked with three arguments; (value, index|key, collection).
+   *
+   * If a property name is passed for `callback`, the created "_.pluck" style
+   * callback will return the property value of the given element.
+   *
+   * If an object is passed for `callback`, the created "_.where" style callback
+   * will return `true` for elements that have the properties of the given object,
+   * else `false`
+   *
+   * @static
+   * @memberOf _
+   * @category Collections
+   * @param {Array|Object|String} collection The collection to iterate over.
+   * @param {Function|Object|String} [callback=identity] The function called per
+   *  iteration. If a property name or object is passed, it will be used to create
+   *  a "_.pluck" or "_.where" style callback, respectively.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Object} Returns the composed aggregate object.
+   * @example
+   *
+   * _.groupBy([4.2, 6.1, 6.4], function(num) { return Math.floor(num); });
+   * // => { '4': [4.2], '6': [6.1, 6.4] }
+   *
+   * _.groupBy([4.2, 6.1, 6.4], function(num) { return this.floor(num); }, Math);
+   * // => { '4': [4.2], '6': [6.1, 6.4] }
+   *
+   * // using "_.pluck" callback shorthand
+   * _.groupBy(['one', 'two', 'three'], 'length');
+   * // => { '3': ['one', 'two'], '5': ['three'] }
+   */
+  function groupBy(collection, callback, thisArg) {
+    var result = {};
+    callback = createCallback(callback, thisArg);
+
+    forEach(collection, function(value, key, collection) {
+      key = String(callback(value, key, collection));
+      (hasOwnProperty.call(result, key) ? result[key] : result[key] = []).push(value);
+    });
+    return result;
+  }
+
+  /**
+   * Invokes the method named by `methodName` on each element in the `collection`,
+   * returning an array of the results of each invoked method. Additional arguments
+   * will be passed to each invoked method. If `methodName` is a function, it will
+   * be invoked for, and `this` bound to, each element in the `collection`.
+   *
+   * @static
+   * @memberOf _
+   * @category Collections
+   * @param {Array|Object|String} collection The collection to iterate over.
+   * @param {Function|String} methodName The name of the method to invoke or
+   *  the function invoked per iteration.
+   * @param {Mixed} [arg1, arg2, ...] Arguments to invoke the method with.
+   * @returns {Array} Returns a new array of the results of each invoked method.
+   * @example
+   *
+   * _.invoke([[5, 1, 7], [3, 2, 1]], 'sort');
+   * // => [[1, 5, 7], [1, 2, 3]]
+   *
+   * _.invoke([123, 456], String.prototype.split, '');
+   * // => [['1', '2', '3'], ['4', '5', '6']]
+   */
+  function invoke(collection, methodName) {
+    var args = slice.call(arguments, 2),
+        index = -1,
+        isFunc = typeof methodName == 'function',
+        length = collection ? collection.length : 0,
+        result = Array(typeof length == 'number' ? length : 0);
+
+    forEach(collection, function(value) {
+      result[++index] = (isFunc ? methodName : value[methodName]).apply(value, args);
+    });
+    return result;
+  }
 
   /**
-   * Produces a new array of values by mapping each value in the `collection`
-   * through a transformation `callback`. The `callback` is bound to `thisArg`
-   * and invoked with 3 arguments; for arrays they are (value, index, array)
-   * and for objects they are (value, key, object).
+   * Creates an array of values by running each element in the `collection`
+   * through the `callback`. The `callback` is bound to `thisArg` and invoked with
+   * three arguments; (value, index|key, collection).
+   *
+   * If a property name is passed for `callback`, the created "_.pluck" style
+   * callback will return the property value of the given element.
+   *
+   * If an object is passed for `callback`, the created "_.where" style callback
+   * will return `true` for elements that have the properties of the given object,
+   * else `false`.
    *
    * @static
    * @memberOf _
    * @alias collect
    * @category Collections
-   * @param {Array|Object} collection The collection to iterate over.
-   * @param {Function} [callback=identity] The function called per iteration.
-   * @param {Mixed} [thisArg] The `this` binding for the callback.
-   * @returns {Array} Returns a new array of values returned by the callback.
+   * @param {Array|Object|String} collection The collection to iterate over.
+   * @param {Function|Object|String} [callback=identity] The function called per
+   *  iteration. If a property name or object is passed, it will be used to create
+   *  a "_.pluck" or "_.where" style callback, respectively.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Array} Returns a new array of the results of each `callback` execution.
    * @example
    *
    * _.map([1, 2, 3], function(num) { return num * 3; });
@@ -699,71 +1802,269 @@
    *
    * _.map({ 'one': 1, 'two': 2, 'three': 3 }, function(num) { return num * 3; });
    * // => [3, 6, 9] (order is not guaranteed)
+   *
+   * var stooges = [
+   *   { 'name': 'moe', 'age': 40 },
+   *   { 'name': 'larry', 'age': 50 }
+   * ];
+   *
+   * // using "_.pluck" callback shorthand
+   * _.map(stooges, 'name');
+   * // => ['moe', 'larry']
    */
-  var map = createIterator(baseIteratorOptions, {
-    'init': '',
-    'exit': 'if (!collection) return []',
-    'beforeLoop': {
-      'array':  'result = Array(length)',
-      'object': 'result = []'
-    },
-    'inLoop': {
-      'array':  'result[index] = callback(collection[index], index, collection)',
-      'object': 'result.push(callback(collection[index], index, collection))'
+  function map(collection, callback, thisArg) {
+    var index = -1,
+        length = collection ? collection.length : 0;
+
+    callback = createCallback(callback, thisArg);
+    if (typeof length == 'number') {
+      var result = Array(length);
+      while (++index < length) {
+        result[index] = callback(collection[index], index, collection);
+      }
+    } else {
+      result = [];
+      forOwn(collection, function(value, key, collection) {
+        result[++index] = callback(value, key, collection);
+      });
     }
-  });
+    return result;
+  }
+
+  /**
+   * Retrieves the maximum value of an `array`. If `callback` is passed,
+   * it will be executed for each value in the `array` to generate the
+   * criterion by which the value is ranked. The `callback` is bound to
+   * `thisArg` and invoked with three arguments; (value, index, collection).
+   *
+   * If a property name is passed for `callback`, the created "_.pluck" style
+   * callback will return the property value of the given element.
+   *
+   * If an object is passed for `callback`, the created "_.where" style callback
+   * will return `true` for elements that have the properties of the given object,
+   * else `false`.
+   *
+   * @static
+   * @memberOf _
+   * @category Collections
+   * @param {Array|Object|String} collection The collection to iterate over.
+   * @param {Function|Object|String} [callback=identity] The function called per
+   *  iteration. If a property name or object is passed, it will be used to create
+   *  a "_.pluck" or "_.where" style callback, respectively.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Mixed} Returns the maximum value.
+   * @example
+   *
+   * _.max([4, 2, 8, 6]);
+   * // => 8
+   *
+   * var stooges = [
+   *   { 'name': 'moe', 'age': 40 },
+   *   { 'name': 'larry', 'age': 50 }
+   * ];
+   *
+   * _.max(stooges, function(stooge) { return stooge.age; });
+   * // => { 'name': 'larry', 'age': 50 };
+   *
+   * // using "_.pluck" callback shorthand
+   * _.max(stooges, 'age');
+   * // => { 'name': 'larry', 'age': 50 };
+   */
+  function max(collection, callback, thisArg) {
+    var computed = -Infinity,
+        result = computed;
+
+    var index = -1,
+        length = collection ? collection.length : 0;
+
+    if (!callback && typeof length == 'number') {
+      while (++index < length) {
+        var value = collection[index];
+        if (value > result) {
+          result = value;
+        }
+      }
+    } else {
+      callback = createCallback(callback, thisArg);
+
+      forEach(collection, function(value, index, collection) {
+        var current = callback(value, index, collection);
+        if (current > computed) {
+          computed = current;
+          result = value;
+        }
+      });
+    }
+    return result;
+  }
+
+  /**
+   * Retrieves the minimum value of an `array`. If `callback` is passed,
+   * it will be executed for each value in the `array` to generate the
+   * criterion by which the value is ranked. The `callback` is bound to `thisArg`
+   * and invoked with three arguments; (value, index, collection).
+   *
+   * If a property name is passed for `callback`, the created "_.pluck" style
+   * callback will return the property value of the given element.
+   *
+   * If an object is passed for `callback`, the created "_.where" style callback
+   * will return `true` for elements that have the properties of the given object,
+   * else `false`.
+   *
+   * @static
+   * @memberOf _
+   * @category Collections
+   * @param {Array|Object|String} collection The collection to iterate over.
+   * @param {Function|Object|String} [callback=identity] The function called per
+   *  iteration. If a property name or object is passed, it will be used to create
+   *  a "_.pluck" or "_.where" style callback, respectively.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Mixed} Returns the minimum value.
+   * @example
+   *
+   * _.min([4, 2, 8, 6]);
+   * // => 2
+   *
+   * var stooges = [
+   *   { 'name': 'moe', 'age': 40 },
+   *   { 'name': 'larry', 'age': 50 }
+   * ];
+   *
+   * _.min(stooges, function(stooge) { return stooge.age; });
+   * // => { 'name': 'moe', 'age': 40 };
+   *
+   * // using "_.pluck" callback shorthand
+   * _.min(stooges, 'age');
+   * // => { 'name': 'moe', 'age': 40 };
+   */
+  function min(collection, callback, thisArg) {
+    var computed = Infinity,
+        result = computed;
+
+    var index = -1,
+        length = collection ? collection.length : 0;
+
+    if (!callback && typeof length == 'number') {
+      while (++index < length) {
+        var value = collection[index];
+        if (value < result) {
+          result = value;
+        }
+      }
+    } else {
+      callback = createCallback(callback, thisArg);
+
+      forEach(collection, function(value, index, collection) {
+        var current = callback(value, index, collection);
+        if (current < computed) {
+          computed = current;
+          result = value;
+        }
+      });
+    }
+    return result;
+  }
+
+  /**
+   * Retrieves the value of a specified property from all elements in the `collection`.
+   *
+   * @static
+   * @memberOf _
+   * @type Function
+   * @category Collections
+   * @param {Array|Object|String} collection The collection to iterate over.
+   * @param {String} property The property to pluck.
+   * @returns {Array} Returns a new array of property values.
+   * @example
+   *
+   * var stooges = [
+   *   { 'name': 'moe', 'age': 40 },
+   *   { 'name': 'larry', 'age': 50 }
+   * ];
+   *
+   * _.pluck(stooges, 'name');
+   * // => ['moe', 'larry']
+   */
+  function pluck(collection, property) {
+    var index = -1,
+        length = collection ? collection.length : 0;
+
+    if (typeof length == 'number') {
+      var result = Array(length);
+      while (++index < length) {
+        result[index] = collection[index][property];
+      }
+    }
+    return result || map(collection, property);
+  }
 
   /**
-   * Boils down a `collection` to a single value. The initial state of the
-   * reduction is `accumulator` and each successive step of it should be returned
-   * by the `callback`. The `callback` is bound to `thisArg` and invoked with 4
-   * arguments; for arrays they are (accumulator, value, index, array) and for
-   * objects they are (accumulator, value, key, object).
+   * Reduces a `collection` to a value that is the accumulated result of running
+   * each element in the `collection` through the `callback`, where each successive
+   * `callback` execution consumes the return value of the previous execution.
+   * If `accumulator` is not passed, the first element of the `collection` will be
+   * used as the initial `accumulator` value. The `callback` is bound to `thisArg`
+   * and invoked with four arguments; (accumulator, value, index|key, collection).
    *
    * @static
    * @memberOf _
    * @alias foldl, inject
    * @category Collections
-   * @param {Array|Object} collection The collection to iterate over.
-   * @param {Function} callback The function called per iteration.
+   * @param {Array|Object|String} collection The collection to iterate over.
+   * @param {Function} [callback=identity] The function called per iteration.
    * @param {Mixed} [accumulator] Initial value of the accumulator.
-   * @param {Mixed} [thisArg] The `this` binding for the callback.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
    * @returns {Mixed} Returns the accumulated value.
    * @example
    *
-   * var sum = _.reduce([1, 2, 3], function(memo, num) { return memo + num; });
+   * var sum = _.reduce([1, 2, 3], function(sum, num) {
+   *   return sum + num;
+   * });
    * // => 6
+   *
+   * var mapped = _.reduce({ 'a': 1, 'b': 2, 'c': 3 }, function(result, num, key) {
+   *   result[key] = num * 3;
+   *   return result;
+   * }, {});
+   * // => { 'a': 3, 'b': 6, 'c': 9 }
    */
-  var reduce = createIterator({
-    'args': 'collection, callback, accumulator, thisArg',
-    'init': 'accumulator',
-    'top':
-      'var noaccum = arguments.length < 3;\n' +
-      'if (thisArg) callback = iteratorBind(callback, thisArg)',
-    'beforeLoop': {
-      'array': 'if (noaccum) result = collection[++index]'
-    },
-    'inLoop': {
-      'array':
-        'result = callback(result, collection[index], index, collection)',
-      'object':
-        'result = noaccum\n' +
-        '  ? (noaccum = false, collection[index])\n' +
-        '  : callback(result, collection[index], index, collection)'
+  function reduce(collection, callback, accumulator, thisArg) {
+    if (!collection) return accumulator;
+    var noaccum = arguments.length < 3;
+    callback = createCallback(callback, thisArg, 4);
+
+    var index = -1,
+        length = collection.length;
+
+    if (typeof length == 'number') {
+      if (noaccum) {
+        accumulator = collection[++index];
+      }
+      while (++index < length) {
+        accumulator = callback(accumulator, collection[index], index, collection);
+      }
+    } else {
+      forOwn(collection, function(value, index, collection) {
+        accumulator = noaccum
+          ? (noaccum = false, value)
+          : callback(accumulator, value, index, collection)
+      });
     }
-  });
+    return accumulator;
+  }
 
   /**
-   * The right-associative version of `_.reduce`.
+   * This method is similar to `_.reduce`, except that it iterates over a
+   * `collection` from right to left.
    *
    * @static
    * @memberOf _
    * @alias foldr
    * @category Collections
-   * @param {Array|Object} collection The collection to iterate over.
-   * @param {Function} callback The function called per iteration.
+   * @param {Array|Object|String} collection The collection to iterate over.
+   * @param {Function} [callback=identity] The function called per iteration.
    * @param {Mixed} [accumulator] Initial value of the accumulator.
-   * @param {Mixed} [thisArg] The `this` binding for the callback.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
    * @returns {Mixed} Returns the accumulated value.
    * @example
    *
@@ -772,93 +2073,249 @@
    * // => [4, 5, 2, 3, 0, 1]
    */
   function reduceRight(collection, callback, accumulator, thisArg) {
-    if (!collection) {
-      return accumulator;
-    }
-
-    var length = collection.length,
+    var iterable = collection,
+        length = collection ? collection.length : 0,
         noaccum = arguments.length < 3;
 
-    if(thisArg) {
-      callback = iteratorBind(callback, thisArg);
-    }
-    if (length === length >>> 0) {
-      if (length && noaccum) {
-        accumulator = collection[--length];
-      }
-      while (length--) {
-        accumulator = callback(accumulator, collection[length], length, collection);
-      }
-      return accumulator;
-    }
-
-    var prop,
-        props = keys(collection);
-
-    length = props.length;
-    if (length && noaccum) {
-      accumulator = collection[props[--length]];
-    }
-    while (length--) {
-      prop = props[length];
-      accumulator = callback(accumulator, collection[prop], prop, collection);
+    if (typeof length != 'number') {
+      var props = keys(collection);
+      length = props.length;
     }
+    callback = createCallback(callback, thisArg, 4);
+    forEach(collection, function(value, index, collection) {
+      index = props ? props[--length] : --length;
+      accumulator = noaccum
+        ? (noaccum = false, iterable[index])
+        : callback(accumulator, iterable[index], index, collection);
+    });
     return accumulator;
   }
 
   /**
-   * The opposite of `_.filter`, this method returns the values of a `collection`
-   * that `callback` does **not** return truthy for.
+   * The opposite of `_.filter`, this method returns the elements of a
+   * `collection` that `callback` does **not** return truthy for.
+   *
+   * If a property name is passed for `callback`, the created "_.pluck" style
+   * callback will return the property value of the given element.
+   *
+   * If an object is passed for `callback`, the created "_.where" style callback
+   * will return `true` for elements that have the properties of the given object,
+   * else `false`.
    *
    * @static
    * @memberOf _
    * @category Collections
-   * @param {Array|Object} collection The collection to iterate over.
-   * @param {Function} [callback=identity] The function called per iteration.
-   * @param {Mixed} [thisArg] The `this` binding for the callback.
-   * @returns {Array} Returns a new array of values that did **not** pass the callback check.
+   * @param {Array|Object|String} collection The collection to iterate over.
+   * @param {Function|Object|String} [callback=identity] The function called per
+   *  iteration. If a property name or object is passed, it will be used to create
+   *  a "_.pluck" or "_.where" style callback, respectively.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Array} Returns a new array of elements that did **not** pass the
+   *  callback check.
    * @example
    *
    * var odds = _.reject([1, 2, 3, 4, 5, 6], function(num) { return num % 2 == 0; });
    * // => [1, 3, 5]
+   *
+   * var food = [
+   *   { 'name': 'apple',  'organic': false, 'type': 'fruit' },
+   *   { 'name': 'carrot', 'organic': true,  'type': 'vegetable' }
+   * ];
+   *
+   * // using "_.pluck" callback shorthand
+   * _.reject(food, 'organic');
+   * // => [{ 'name': 'apple', 'organic': false, 'type': 'fruit' }]
+   *
+   * // using "_.where" callback shorthand
+   * _.reject(food, { 'type': 'fruit' });
+   * // => [{ 'name': 'carrot', 'organic': true, 'type': 'vegetable' }]
    */
-  var reject = createIterator(baseIteratorOptions, filterIteratorOptions, {
-    'inLoop': '!' + filterIteratorOptions.inLoop
-  });
+  function reject(collection, callback, thisArg) {
+    callback = createCallback(callback, thisArg);
+    return filter(collection, function(value, index, collection) {
+      return !callback(value, index, collection);
+    });
+  }
+
+  /**
+   * Creates an array of shuffled `array` values, using a version of the
+   * Fisher-Yates shuffle. See http://en.wikipedia.org/wiki/Fisher-Yates_shuffle.
+   *
+   * @static
+   * @memberOf _
+   * @category Collections
+   * @param {Array|Object|String} collection The collection to shuffle.
+   * @returns {Array} Returns a new shuffled collection.
+   * @example
+   *
+   * _.shuffle([1, 2, 3, 4, 5, 6]);
+   * // => [4, 1, 6, 3, 5, 2]
+   */
+  function shuffle(collection) {
+    var index = -1,
+        length = collection ? collection.length : 0,
+        result = Array(typeof length == 'number' ? length : 0);
+
+    forEach(collection, function(value) {
+      var rand = floor(nativeRandom() * (++index + 1));
+      result[index] = result[rand];
+      result[rand] = value;
+    });
+    return result;
+  }
+
+  /**
+   * Gets the size of the `collection` by returning `collection.length` for arrays
+   * and array-like objects or the number of own enumerable properties for objects.
+   *
+   * @static
+   * @memberOf _
+   * @category Collections
+   * @param {Array|Object|String} collection The collection to inspect.
+   * @returns {Number} Returns `collection.length` or number of own enumerable properties.
+   * @example
+   *
+   * _.size([1, 2]);
+   * // => 2
+   *
+   * _.size({ 'one': 1, 'two': 2, 'three': 3 });
+   * // => 3
+   *
+   * _.size('curly');
+   * // => 5
+   */
+  function size(collection) {
+    var length = collection ? collection.length : 0;
+    return typeof length == 'number' ? length : keys(collection).length;
+  }
 
   /**
    * Checks if the `callback` returns a truthy value for **any** element of a
    * `collection`. The function returns as soon as it finds passing value, and
    * does not iterate over the entire `collection`. The `callback` is bound to
-   * `thisArg` and invoked with 3 arguments; for arrays they are
-   * (value, index, array) and for objects they are (value, key, object).
+   * `thisArg` and invoked with three arguments; (value, index|key, collection).
+   *
+   * If a property name is passed for `callback`, the created "_.pluck" style
+   * callback will return the property value of the given element.
+   *
+   * If an object is passed for `callback`, the created "_.where" style callback
+   * will return `true` for elements that have the properties of the given object,
+   * else `false`.
    *
    * @static
    * @memberOf _
    * @alias any
    * @category Collections
-   * @param {Array|Object} collection The collection to iterate over.
-   * @param {Function} [callback=identity] The function called per iteration.
-   * @param {Mixed} [thisArg] The `this` binding for the callback.
-   * @returns {Boolean} Returns `true` if any value passes the callback check, else `false`.
+   * @param {Array|Object|String} collection The collection to iterate over.
+   * @param {Function|Object|String} [callback=identity] The function called per
+   *  iteration. If a property name or object is passed, it will be used to create
+   *  a "_.pluck" or "_.where" style callback, respectively.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Boolean} Returns `true` if any element passes the callback check,
+   *  else `false`.
    * @example
    *
-   * _.some([null, 0, 'yes', false]);
+   * _.some([null, 0, 'yes', false], Boolean);
+   * // => true
+   *
+   * var food = [
+   *   { 'name': 'apple',  'organic': false, 'type': 'fruit' },
+   *   { 'name': 'carrot', 'organic': true,  'type': 'vegetable' }
+   * ];
+   *
+   * // using "_.pluck" callback shorthand
+   * _.some(food, 'organic');
    * // => true
+   *
+   * // using "_.where" callback shorthand
+   * _.some(food, { 'type': 'meat' });
+   * // => false
    */
-  var some = createIterator(baseIteratorOptions, everyIteratorOptions, {
-    'init': 'false',
-    'inLoop': everyIteratorOptions.inLoop.replace('!', '')
-  });
+  function some(collection, callback, thisArg) {
+    var result;
+    callback = createCallback(callback, thisArg);
+
+    var index = -1,
+        length = collection ? collection.length : 0;
+
+    if (typeof length == 'number') {
+      while (++index < length) {
+        if ((result = callback(collection[index], index, collection))) {
+          break;
+        }
+      }
+    } else {
+      forOwn(collection, function(value, index, collection) {
+        return (result = callback(value, index, collection)) && indicatorObject;
+      });
+    }
+    return !!result;
+  }
 
   /**
-   * Converts the `collection`, into an array. Useful for converting the
-   * `arguments` object.
+   * Creates an array of elements, sorted in ascending order by the results of
+   * running each element in the `collection` through the `callback`. This method
+   * performs a stable sort, that is, it will preserve the original sort order of
+   * equal elements. The `callback` is bound to `thisArg` and invoked with three
+   * arguments; (value, index|key, collection).
+   *
+   * If a property name is passed for `callback`, the created "_.pluck" style
+   * callback will return the property value of the given element.
+   *
+   * If an object is passed for `callback`, the created "_.where" style callback
+   * will return `true` for elements that have the properties of the given object,
+   * else `false`.
    *
    * @static
    * @memberOf _
    * @category Collections
-   * @param {Array|Object} collection The collection to convert.
+   * @param {Array|Object|String} collection The collection to iterate over.
+   * @param {Function|Object|String} [callback=identity] The function called per
+   *  iteration. If a property name or object is passed, it will be used to create
+   *  a "_.pluck" or "_.where" style callback, respectively.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Array} Returns a new array of sorted elements.
+   * @example
+   *
+   * _.sortBy([1, 2, 3], function(num) { return Math.sin(num); });
+   * // => [3, 1, 2]
+   *
+   * _.sortBy([1, 2, 3], function(num) { return this.sin(num); }, Math);
+   * // => [3, 1, 2]
+   *
+   * // using "_.pluck" callback shorthand
+   * _.sortBy(['banana', 'strawberry', 'apple'], 'length');
+   * // => ['apple', 'banana', 'strawberry']
+   */
+  function sortBy(collection, callback, thisArg) {
+    var index = -1,
+        length = collection ? collection.length : 0,
+        result = Array(typeof length == 'number' ? length : 0);
+
+    callback = createCallback(callback, thisArg);
+    forEach(collection, function(value, key, collection) {
+      result[++index] = {
+        'criteria': callback(value, key, collection),
+        'index': index,
+        'value': value
+      };
+    });
+
+    length = result.length;
+    result.sort(compareAscending);
+    while (length--) {
+      result[length] = result[length].value;
+    }
+    return result;
+  }
+
+  /**
+   * Converts the `collection` to an array.
+   *
+   * @static
+   * @memberOf _
+   * @category Collections
+   * @param {Array|Object|String} collection The collection to convert.
    * @returns {Array} Returns the new converted array.
    * @example
    *
@@ -866,23 +2323,48 @@
    * // => [2, 3, 4]
    */
   function toArray(collection) {
-    if (!collection) {
-      return [];
-    }
-    if (toString.call(collection.toArray) == funcClass) {
-      return collection.toArray();
-    }
-    var length = collection.length;
-    if (length === length >>> 0) {
+    if (isArray(collection)) {
       return slice.call(collection);
     }
+    if (collection && typeof collection.length == 'number') {
+      return map(collection);
+    }
     return values(collection);
   }
 
+  /**
+   * Examines each element in a `collection`, returning an array of all elements
+   * that have the given `properties`. When checking `properties`, this method
+   * performs a deep comparison between values to determine if they are equivalent
+   * to each other.
+   *
+   * @static
+   * @memberOf _
+   * @type Function
+   * @category Collections
+   * @param {Array|Object|String} collection The collection to iterate over.
+   * @param {Object} properties The object of property values to filter by.
+   * @returns {Array} Returns a new array of elements that have the given `properties`.
+   * @example
+   *
+   * var stooges = [
+   *   { 'name': 'moe', 'age': 40 },
+   *   { 'name': 'larry', 'age': 50 }
+   * ];
+   *
+   * _.where(stooges, { 'age': 40 });
+   * // => [{ 'name': 'moe', 'age': 40 }]
+   */
+  function where(collection, properties, first) {
+    return (first && isEmpty(properties))
+      ? null
+      : (first ? find : filter)(collection, properties);
+  }
+
   /*--------------------------------------------------------------------------*/
 
   /**
-   * Produces a new array with all falsey values of `array` removed. The values
+   * Creates an array with all falsey values of `array` removed. The values
    * `false`, `null`, `0`, `""`, `undefined` and `NaN` are all falsey.
    *
    * @static
@@ -896,23 +2378,21 @@
    * // => [1, 2, 3]
    */
   function compact(array) {
-    var result = [];
-    if (!array) {
-      return result;
-    }
     var index = -1,
-        length = array.length;
+        length = array ? array.length : 0,
+        result = [];
 
     while (++index < length) {
-      if (array[index]) {
-        result.push(array[index]);
+      var value = array[index];
+      if (value) {
+        result.push(value);
       }
     }
     return result;
   }
 
   /**
-   * Produces a new array of `array` values not present in the other arrays
+   * Creates an array of `array` elements not present in the other arrays
    * using strict equality for comparisons, i.e. `===`.
    *
    * @static
@@ -920,7 +2400,7 @@
    * @category Arrays
    * @param {Array} array The array to process.
    * @param {Array} [array1, array2, ...] Arrays to check.
-   * @returns {Array} Returns a new array of `array` values not present in the
+   * @returns {Array} Returns a new array of `array` elements not present in the
    *  other arrays.
    * @example
    *
@@ -928,56 +2408,121 @@
    * // => [1, 3, 4]
    */
   function difference(array) {
-    var result = [];
-    if (!array) {
-      return result;
-    }
     var index = -1,
         length = array.length,
-        flattened = concat.apply(result, slice.call(arguments, 1));
+        flattened = concat.apply(arrayRef, arguments),
+        result = [];
 
     while (++index < length) {
-      if (indexOf(flattened, array[index]) < 0) {
-        result.push(array[index]);
+      var value = array[index];
+      if (indexOf(flattened, value, length) < 0) {
+        result.push(value);
       }
     }
     return result;
   }
 
   /**
-   * Gets the first value of the `array`. Pass `n` to return the first `n` values
-   * of the `array`.
+   * Gets the first element of the `array`. If a number `n` is passed, the first
+   * `n` elements of the `array` are returned. If a `callback` function is passed,
+   * elements at the beginning of the array are returned as long as the `callback`
+   * returns truthy. The `callback` is bound to `thisArg` and invoked with three
+   * arguments; (value, index, array).
+   *
+   * If a property name is passed for `callback`, the created "_.pluck" style
+   * callback will return the property value of the given element.
+   *
+   * If an object is passed for `callback`, the created "_.where" style callback
+   * will return `true` for elements that have the properties of the given object,
+   * else `false`.
    *
    * @static
    * @memberOf _
    * @alias head, take
    * @category Arrays
    * @param {Array} array The array to query.
-   * @param {Number} [n] The number of elements to return.
-   * @param {Object} [guard] Internally used to allow this method to work with
-   *  others like `_.map` without using their callback `index` argument for `n`.
-   * @returns {Mixed} Returns the first value or an array of the first `n` values
-   *  of `array`.
+   * @param {Function|Object|Number|String} [callback|n] The function called
+   *  per element or the number of elements to return. If a property name or
+   *  object is passed, it will be used to create a "_.pluck" or "_.where"
+   *  style callback, respectively.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Mixed} Returns the first element(s) of `array`.
    * @example
    *
-   * _.first([5, 4, 3, 2, 1]);
-   * // => 5
+   * _.first([1, 2, 3]);
+   * // => 1
+   *
+   * _.first([1, 2, 3], 2);
+   * // => [1, 2]
+   *
+   * _.first([1, 2, 3], function(num) {
+   *   return num < 3;
+   * });
+   * // => [1, 2]
+   *
+   * var food = [
+   *   { 'name': 'banana', 'organic': true },
+   *   { 'name': 'beet',   'organic': false },
+   * ];
+   *
+   * // using "_.pluck" callback shorthand
+   * _.first(food, 'organic');
+   * // => [{ 'name': 'banana', 'organic': true }]
+   *
+   * var food = [
+   *   { 'name': 'apple',  'type': 'fruit' },
+   *   { 'name': 'banana', 'type': 'fruit' },
+   *   { 'name': 'beet',   'type': 'vegetable' }
+   * ];
+   *
+   * // using "_.where" callback shorthand
+   * _.first(food, { 'type': 'fruit' });
+   * // => [{ 'name': 'apple', 'type': 'fruit' }, { 'name': 'banana', 'type': 'fruit' }]
    */
-  function first(array, n, guard) {
+  function first(array, callback, thisArg) {
     if (array) {
-      return (n == undefined || guard) ? array[0] : slice.call(array, 0, n);
+      var n = 0,
+          length = array.length;
+
+      if (typeof callback != 'number' && callback != null) {
+        var index = -1;
+        callback = createCallback(callback, thisArg);
+        while (++index < length && callback(array[index], index, array)) {
+          n++;
+        }
+      } else {
+        n = callback;
+        if (n == null || thisArg) {
+          return array[0];
+        }
+      }
+      return slice.call(array, 0, nativeMin(nativeMax(0, n), length));
     }
   }
 
   /**
-   * Flattens a nested array (the nesting can be to any depth). If `shallow` is
-   * truthy, `array` will only be flattened a single level.
+   * Flattens a nested array (the nesting can be to any depth). If `isShallow`
+   * is truthy, `array` will only be flattened a single level. If `callback`
+   * is passed, each element of `array` is passed through a callback` before
+   * flattening. The `callback` is bound to `thisArg` and invoked with three
+   * arguments; (value, index, array).
+   *
+   * If a property name is passed for `callback`, the created "_.pluck" style
+   * callback will return the property value of the given element.
+   *
+   * If an object is passed for `callback`, the created "_.where" style callback
+   * will return `true` for elements that have the properties of the given object,
+   * else `false`.
    *
    * @static
    * @memberOf _
    * @category Arrays
    * @param {Array} array The array to compact.
-   * @param {Boolean} shallow A flag to indicate only flattening a single level.
+   * @param {Boolean} [isShallow=false] A flag to indicate only flattening a single level.
+   * @param {Function|Object|String} [callback=identity] The function called per
+   *  iteration. If a property name or object is passed, it will be used to create
+   *  a "_.pluck" or "_.where" style callback, respectively.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
    * @returns {Array} Returns a new flattened array.
    * @example
    *
@@ -986,20 +2531,25 @@
    *
    * _.flatten([1, [2], [3, [[4]]]], true);
    * // => [1, 2, 3, [[4]]];
+   *
+   * var stooges = [
+   *   { 'name': 'curly', 'quotes': ['Oh, a wise guy, eh?', 'Poifect!'] },
+   *   { 'name': 'moe', 'quotes': ['Spread out!', 'You knucklehead!'] }
+   * ];
+   *
+   * // using "_.pluck" callback shorthand
+   * _.flatten(stooges, 'quotes');
+   * // => ['Oh, a wise guy, eh?', 'Poifect!', 'Spread out!', 'You knucklehead!']
    */
-  function flatten(array, shallow) {
-    var result = [];
-    if (!array) {
-      return result;
-    }
-    var value,
-        index = -1,
-        length = array.length;
+  function flatten(array, isShallow) {
+    var index = -1,
+        length = array ? array.length : 0,
+        result = [];
 
     while (++index < length) {
-      value = array[index];
+      var value = array[index];
       if (isArray(value)) {
-        push.apply(result, shallow ? value : flatten(value));
+        push.apply(result, isShallow ? value : flatten(value));
       } else {
         result.push(value);
       }
@@ -1008,64 +2558,17 @@
   }
 
   /**
-   * Splits `array` into sets, grouped by the result of running each value
-   * through `callback`. The `callback` is bound to `thisArg` and invoked with 3
-   * arguments; (value, index, array). The `callback` argument may also be the
-   * name of a property to group by.
-   *
-   * @static
-   * @memberOf _
-   * @category Arrays
-   * @param {Array} array The array to iterate over.
-   * @param {Function|String} callback The function called per iteration or
-   *  property name to group by.
-   * @param {Mixed} [thisArg] The `this` binding for the callback.
-   * @returns {Object} Returns an object of grouped values.
-   * @example
-   *
-   * _.groupBy([1.3, 2.1, 2.4], function(num) { return Math.floor(num); });
-   * // => { '1': [1.3], '2': [2.1, 2.4] }
-   *
-   * _.groupBy([1.3, 2.1, 2.4], function(num) { return this.floor(num); }, Math);
-   * // => { '1': [1.3], '2': [2.1, 2.4] }
-   *
-   * _.groupBy(['one', 'two', 'three'], 'length');
-   * // => { '3': ['one', 'two'], '5': ['three'] }
-   */
-  function groupBy(array, callback, thisArg) {
-    var result = {};
-    if (!array) {
-      return result;
-    }
-    var prop,
-        value,
-        index = -1,
-        isFunc = typeof callback == 'function',
-        length = array.length;
-
-    if (isFunc && thisArg) {
-      callback = iteratorBind(callback, thisArg);
-    }
-    while (++index < length) {
-      value = array[index];
-      prop = isFunc ? callback(value, index, array) : value[callback];
-      (hasOwnProperty.call(result, prop) ? result[prop] : result[prop] = []).push(value);
-    }
-    return result;
-  }
-
-  /**
    * Gets the index at which the first occurrence of `value` is found using
    * strict equality for comparisons, i.e. `===`. If the `array` is already
-   * sorted, passing `true` for `isSorted` will run a faster binary search.
+   * sorted, passing `true` for `fromIndex` will run a faster binary search.
    *
    * @static
    * @memberOf _
    * @category Arrays
    * @param {Array} array The array to search.
    * @param {Mixed} value The value to search for.
-   * @param {Boolean|Number} [fromIndex=0] The index to start searching from or
-   *  `true` to perform a binary search on a sorted `array`.
+   * @param {Boolean|Number} [fromIndex=0] The index to search from or `true` to
+   *  perform a binary search on a sorted `array`.
    * @returns {Number} Returns the index of the matched value or `-1`.
    * @example
    *
@@ -1079,19 +2582,14 @@
    * // => 2
    */
   function indexOf(array, value, fromIndex) {
-    if (!array) {
-      return -1;
-    }
     var index = -1,
-        length = array.length;
+        length = array ? array.length : 0;
 
-    if (fromIndex) {
-      if (typeof fromIndex == 'number') {
-        index = (fromIndex < 0 ? Math.max(0, length + fromIndex) : fromIndex) - 1;
-      } else {
-        index = sortedIndex(array, value);
-        return array[index] === value ? index : -1;
-      }
+    if (typeof fromIndex == 'number') {
+      index = (fromIndex < 0 ? nativeMax(0, length + fromIndex) : fromIndex || 0) - 1;
+    } else if (fromIndex) {
+      index = sortedIndex(array, value);
+      return array[index] === value ? index : -1;
     }
     while (++index < length) {
       if (array[index] === value) {
@@ -1102,57 +2600,112 @@
   }
 
   /**
-   * Gets all but the last value of `array`. Pass `n` to exclude the last `n`
-   * values from the result.
+   * Gets all but the last element of `array`. If a number `n` is passed, the
+   * last `n` elements are excluded from the result. If a `callback` function
+   * is passed, elements at the end of the array are excluded from the result
+   * as long as the `callback` returns truthy. The `callback` is bound to
+   * `thisArg` and invoked with three arguments; (value, index, array).
+   *
+   * If a property name is passed for `callback`, the created "_.pluck" style
+   * callback will return the property value of the given element.
+   *
+   * If an object is passed for `callback`, the created "_.where" style callback
+   * will return `true` for elements that have the properties of the given object,
+   * else `false`.
    *
    * @static
    * @memberOf _
    * @category Arrays
    * @param {Array} array The array to query.
-   * @param {Number} [n] The number of elements to return.
-   * @param {Object} [guard] Internally used to allow this method to work with
-   *  others like `_.map` without using their callback `index` argument for `n`.
-   * @returns {Array} Returns all but the last value or `n` values of `array`.
+   * @param {Function|Object|Number|String} [callback|n=1] The function called
+   *  per element or the number of elements to exclude. If a property name or
+   *  object is passed, it will be used to create a "_.pluck" or "_.where"
+   *  style callback, respectively.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Array} Returns a slice of `array`.
    * @example
    *
-   * _.initial([3, 2, 1]);
-   * // => [3, 2]
+   * _.initial([1, 2, 3]);
+   * // => [1, 2]
+   *
+   * _.initial([1, 2, 3], 2);
+   * // => [1]
+   *
+   * _.initial([1, 2, 3], function(num) {
+   *   return num > 1;
+   * });
+   * // => [1]
+   *
+   * var food = [
+   *   { 'name': 'beet',   'organic': false },
+   *   { 'name': 'carrot', 'organic': true }
+   * ];
+   *
+   * // using "_.pluck" callback shorthand
+   * _.initial(food, 'organic');
+   * // => [{ 'name': 'beet',   'organic': false }]
+   *
+   * var food = [
+   *   { 'name': 'banana', 'type': 'fruit' },
+   *   { 'name': 'beet',   'type': 'vegetable' },
+   *   { 'name': 'carrot', 'type': 'vegetable' }
+   * ];
+   *
+   * // using "_.where" callback shorthand
+   * _.initial(food, { 'type': 'vegetable' });
+   * // => [{ 'name': 'banana', 'type': 'fruit' }]
    */
-  function initial(array, n, guard) {
+  function initial(array, callback, thisArg) {
     if (!array) {
       return [];
     }
-    return slice.call(array, 0, -((n == undefined || guard) ? 1 : n));
+    var n = 0,
+        length = array.length;
+
+    if (typeof callback != 'number' && callback != null) {
+      var index = length;
+      callback = createCallback(callback, thisArg);
+      while (index-- && callback(array[index], index, array)) {
+        n++;
+      }
+    } else {
+      n = (callback == null || thisArg) ? 1 : callback || n;
+    }
+    return slice.call(array, 0, nativeMin(nativeMax(0, length - n), length));
   }
 
   /**
-   * Computes the intersection of all the passed-in arrays.
+   * Computes the intersection of all the passed-in arrays using strict equality
+   * for comparisons, i.e. `===`.
    *
    * @static
    * @memberOf _
    * @category Arrays
    * @param {Array} [array1, array2, ...] Arrays to process.
-   * @returns {Array} Returns a new array of unique values, in order, that are
-   *  present in **all** of the arrays.
+   * @returns {Array} Returns a new array of unique elements that are present
+   *  in **all** of the arrays.
    * @example
    *
    * _.intersection([1, 2, 3], [101, 2, 1, 10], [2, 1]);
    * // => [1, 2]
    */
   function intersection(array) {
-    var result = [];
-    if (!array) {
-      return result;
-    }
-    var value,
+    var args = arguments,
+        argsLength = args.length,
         index = -1,
-        length = array.length,
-        others = slice.call(arguments, 1);
+        length = array ? array.length : 0,
+        result = [];
 
+    outer:
     while (++index < length) {
-      value = array[index];
-      if (indexOf(result, value) < 0 &&
-          every(others, function(other) { return indexOf(other, value) > -1; })) {
+      var value = array[index];
+      if (indexOf(result, value) < 0) {
+        var argsIndex = argsLength;
+        while (--argsIndex) {
+          if (indexOf(args[argsIndex], value) < 0) {
+            continue outer;
+          }
+        }
         result.push(value);
       }
     }
@@ -1160,78 +2713,94 @@
   }
 
   /**
-   * Invokes the method named by `methodName` on each element of `array`.
-   * Additional arguments will be passed to each invoked method. If `methodName`
-   * is a function it will be invoked for, and `this` bound to, each element
-   * of `array`.
+   * Gets the last element of the `array`. If a number `n` is passed, the
+   * last `n` elements of the `array` are returned. If a `callback` function
+   * is passed, elements at the end of the array are returned as long as the
+   * `callback` returns truthy. The `callback` is bound to `thisArg` and
+   * invoked with three arguments;(value, index, array).
    *
-   * @static
-   * @memberOf _
-   * @category Arrays
-   * @param {Array} array The array to iterate over.
-   * @param {Function|String} methodName The name of the method to invoke or
-   *  the function invoked per iteration.
-   * @param {Mixed} [arg1, arg2, ...] Arguments to invoke the method with.
-   * @returns {Array} Returns a new array of values returned from each invoked method.
-   * @example
    *
-   * _.invoke([[5, 1, 7], [3, 2, 1]], 'sort');
-   * // => [[1, 5, 7], [1, 2, 3]]
+   * If a property name is passed for `callback`, the created "_.pluck" style
+   * callback will return the property value of the given element.
    *
-   * _.invoke([123, 456], String.prototype.split, '');
-   * // => [['1', '2', '3'], ['4', '5', '6']]
-   */
-  function invoke(array, methodName) {
-    var result = [];
-    if (!array) {
-      return result;
-    }
-    var args = slice.call(arguments, 2),
-        index = -1,
-        length = array.length,
-        isFunc = typeof methodName == 'function';
-
-    while (++index < length) {
-      result[index] = (isFunc ? methodName : array[index][methodName]).apply(array[index], args);
-    }
-    return result;
-  }
-
-  /**
-   * Gets the last value of the `array`. Pass `n` to return the lasy `n` values
-   * of the `array`.
+   * If an object is passed for `callback`, the created "_.where" style callback
+   * will return `true` for elements that have the properties of the given object,
+   * else `false`.
    *
    * @static
    * @memberOf _
    * @category Arrays
    * @param {Array} array The array to query.
-   * @param {Number} [n] The number of elements to return.
-   * @param {Object} [guard] Internally used to allow this method to work with
-   *  others like `_.map` without using their callback `index` argument for `n`.
-   * @returns {Mixed} Returns the last value or an array of the last `n` values
-   *  of `array`.
+   * @param {Function|Object|Number|String} [callback|n] The function called
+   *  per element or the number of elements to return. If a property name or
+   *  object is passed, it will be used to create a "_.pluck" or "_.where"
+   *  style callback, respectively.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Mixed} Returns the last element(s) of `array`.
    * @example
    *
-   * _.last([3, 2, 1]);
-   * // => 1
+   * _.last([1, 2, 3]);
+   * // => 3
+   *
+   * _.last([1, 2, 3], 2);
+   * // => [2, 3]
+   *
+   * _.last([1, 2, 3], function(num) {
+   *   return num > 1;
+   * });
+   * // => [2, 3]
+   *
+   * var food = [
+   *   { 'name': 'beet',   'organic': false },
+   *   { 'name': 'carrot', 'organic': true }
+   * ];
+   *
+   * // using "_.pluck" callback shorthand
+   * _.last(food, 'organic');
+   * // => [{ 'name': 'carrot', 'organic': true }]
+   *
+   * var food = [
+   *   { 'name': 'banana', 'type': 'fruit' },
+   *   { 'name': 'beet',   'type': 'vegetable' },
+   *   { 'name': 'carrot', 'type': 'vegetable' }
+   * ];
+   *
+   * // using "_.where" callback shorthand
+   * _.last(food, { 'type': 'vegetable' });
+   * // => [{ 'name': 'beet', 'type': 'vegetable' }, { 'name': 'carrot', 'type': 'vegetable' }]
    */
-  function last(array, n, guard) {
+  function last(array, callback, thisArg) {
     if (array) {
-      var length = array.length;
-      return (n == undefined || guard) ? array[length - 1] : slice.call(array, -n || length);
+      var n = 0,
+          length = array.length;
+
+      if (typeof callback != 'number' && callback != null) {
+        var index = length;
+        callback = createCallback(callback, thisArg);
+        while (index-- && callback(array[index], index, array)) {
+          n++;
+        }
+      } else {
+        n = callback;
+        if (n == null || thisArg) {
+          return array[length - 1];
+        }
+      }
+      return slice.call(array, nativeMax(0, length - n));
     }
   }
 
   /**
-   * Gets the index at which the last occurrence of `value` is found using
-   * strict equality for comparisons, i.e. `===`.
+   * Gets the index at which the last occurrence of `value` is found using strict
+   * equality for comparisons, i.e. `===`. If `fromIndex` is negative, it is used
+   * as the offset from the end of the collection.
    *
    * @static
    * @memberOf _
    * @category Arrays
    * @param {Array} array The array to search.
    * @param {Mixed} value The value to search for.
-   * @param {Number} [fromIndex=array.length-1] The index to start searching from.
+   * @param {Number} [fromIndex=array.length-1] The index to search from.
    * @returns {Number} Returns the index of the matched value or `-1`.
    * @example
    *
@@ -1242,12 +2811,9 @@
    * // => 1
    */
   function lastIndexOf(array, value, fromIndex) {
-    if (!array) {
-      return -1;
-    }
-    var index = array.length;
-    if (fromIndex && typeof fromIndex == 'number') {
-      index = (fromIndex < 0 ? Math.max(0, index + fromIndex) : Math.min(fromIndex, index - 1)) + 1;
+    var index = array ? array.length : 0;
+    if (typeof fromIndex == 'number') {
+      index = (fromIndex < 0 ? nativeMax(0, index + fromIndex) : nativeMin(fromIndex, index - 1)) + 1;
     }
     while (index--) {
       if (array[index] === value) {
@@ -1258,156 +2824,15 @@
   }
 
   /**
-   * Retrieves the maximum value of an `array`. If `callback` is passed,
-   * it will be executed for each value in the `array` to generate the
-   * criterion by which the value is ranked. The `callback` is bound to
-   * `thisArg` and invoked with 3 arguments; (value, index, array).
-   *
-   * @static
-   * @memberOf _
-   * @category Arrays
-   * @param {Array} array The array to iterate over.
-   * @param {Function} [callback] The function called per iteration.
-   * @param {Mixed} [thisArg] The `this` binding for the callback.
-   * @returns {Mixed} Returns the maximum value.
-   * @example
-   *
-   * var stooges = [
-   *   { 'name': 'moe', 'age': 40 },
-   *   { 'name': 'larry', 'age': 50 },
-   *   { 'name': 'curly', 'age': 60 }
-   * ];
-   *
-   * _.max(stooges, function(stooge) { return stooge.age; });
-   * // => { 'name': 'curly', 'age': 60 };
-   */
-  function max(array, callback, thisArg) {
-    var computed = -Infinity,
-        result = computed;
-
-    if (!array) {
-      return result;
-    }
-    var current,
-        index = -1,
-        length = array.length;
-
-    if (!callback) {
-      while (++index < length) {
-        if (array[index] > result) {
-          result = array[index];
-        }
-      }
-      return result;
-    }
-    if (thisArg) {
-      callback = iteratorBind(callback, thisArg);
-    }
-    while (++index < length) {
-      current = callback(array[index], index, array);
-      if (current > computed) {
-        computed = current;
-        result = array[index];
-      }
-    }
-    return result;
-  }
-
-  /**
-   * Retrieves the minimum value of an `array`. If `callback` is passed,
-   * it will be executed for each value in the `array` to generate the
-   * criterion by which the value is ranked. The `callback` is bound to `thisArg`
-   * and invoked with 3 arguments; (value, index, array).
-   *
-   * @static
-   * @memberOf _
-   * @category Arrays
-   * @param {Array} array The array to iterate over.
-   * @param {Function} [callback] The function called per iteration.
-   * @param {Mixed} [thisArg] The `this` binding for the callback.
-   * @returns {Mixed} Returns the minimum value.
-   * @example
-   *
-   * _.min([10, 5, 100, 2, 1000]);
-   * // => 2
-   */
-  function min(array, callback, thisArg) {
-    var computed = Infinity,
-        result = computed;
-
-    if (!array) {
-      return result;
-    }
-    var current,
-        index = -1,
-        length = array.length;
-
-    if (!callback) {
-      while (++index < length) {
-        if (array[index] < result) {
-          result = array[index];
-        }
-      }
-      return result;
-    }
-    if (thisArg) {
-      callback = iteratorBind(callback, thisArg);
-    }
-    while (++index < length) {
-      current = callback(array[index], index, array);
-      if (current < computed) {
-        computed = current;
-        result = array[index];
-      }
-    }
-    return result;
-  }
-
-  /**
-   * Retrieves the value of a specified property from all elements in `array`.
-   *
-   * @static
-   * @memberOf _
-   * @category Arrays
-   * @param {Array} array The array to iterate over.
-   * @param {String} property The property to pluck.
-   * @returns {Array} Returns a new array of property values.
-   * @example
-   *
-   * var stooges = [
-   *   { 'name': 'moe', 'age': 40 },
-   *   { 'name': 'larry', 'age': 50 },
-   *   { 'name': 'curly', 'age': 60 }
-   * ];
-   *
-   * _.pluck(stooges, 'name');
-   * // => ['moe', 'larry', 'curly']
-   */
-  function pluck(array, property) {
-    if (!array) {
-      return [];
-    }
-    var index = -1,
-        length = array.length,
-        result = Array(length);
-
-    while (++index < length) {
-      result[index] = array[index][property];
-    }
-    return result;
-  }
-
-  /**
    * Creates an array of numbers (positive and/or negative) progressing from
-   * `start` up to but not including `stop`. This method is a port of Python's
-   * `range()` function. See http://docs.python.org/library/functions.html#range.
+   * `start` up to but not including `end`.
    *
    * @static
    * @memberOf _
    * @category Arrays
    * @param {Number} [start=0] The start of the range.
    * @param {Number} end The end of the range.
-   * @param {Number} [step=1] The value to increment or descrement by.
+   * @param {Number} [step=1] The value to increment or decrement by.
    * @returns {Array} Returns a new range array.
    * @example
    *
@@ -1427,14 +2852,17 @@
    * // => []
    */
   function range(start, end, step) {
-    step || (step = 1);
-    if (arguments.length < 2) {
-      end = start || 0;
+    start = +start || 0;
+    step = +step || 1;
+
+    if (end == null) {
+      end = start;
       start = 0;
     }
-
+    // use `Array(length)` so V8 will avoid the slower "dictionary" mode
+    // http://youtu.be/XAqIpGU8ZZk#t=17m25s
     var index = -1,
-        length = Math.max(Math.ceil((end - start) / step), 0),
+        length = nativeMax(0, ceil((end - start) / step)),
         result = Array(length);
 
     while (++index < length) {
@@ -1446,122 +2874,76 @@
 
   /**
    * The opposite of `_.initial`, this method gets all but the first value of
-   * `array`. Pass `n` to exclude the first `n` values from the result.
+   * `array`. If a number `n` is passed, the first `n` values are excluded from
+   * the result. If a `callback` function is passed, elements at the beginning
+   * of the array are excluded from the result as long as the `callback` returns
+   * truthy. The `callback` is bound to `thisArg` and invoked with three
+   * arguments; (value, index, array).
+   *
+   * If a property name is passed for `callback`, the created "_.pluck" style
+   * callback will return the property value of the given element.
+   *
+   * If an object is passed for `callback`, the created "_.where" style callback
+   * will return `true` for elements that have the properties of the given object,
+   * else `false`.
    *
    * @static
    * @memberOf _
-   * @alias tail
+   * @alias drop, tail
    * @category Arrays
    * @param {Array} array The array to query.
-   * @param {Number} [n] The number of elements to return.
-   * @param {Object} [guard] Internally used to allow this method to work with
-   *  others like `_.map` without using their callback `index` argument for `n`.
-   * @returns {Array} Returns all but the first value or `n` values of `array`.
+   * @param {Function|Object|Number|String} [callback|n=1] The function called
+   *  per element or the number of elements to exclude. If a property name or
+   *  object is passed, it will be used to create a "_.pluck" or "_.where"
+   *  style callback, respectively.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Array} Returns a slice of `array`.
    * @example
    *
-   * _.rest([3, 2, 1]);
-   * // => [2, 1]
-   */
-  function rest(array, n, guard) {
-    if (!array) {
-      return [];
-    }
-    return slice.call(array, (n == undefined || guard) ? 1 : n);
-  }
-
-  /**
-   * Produces a new array of shuffled `array` values, using a version of the
-   * Fisher-Yates shuffle. See http://en.wikipedia.org/wiki/Fisher-Yates_shuffle.
+   * _.rest([1, 2, 3]);
+   * // => [2, 3]
    *
-   * @static
-   * @memberOf _
-   * @category Arrays
-   * @param {Array} array The array to shuffle.
-   * @returns {Array} Returns a new shuffled array.
-   * @example
+   * _.rest([1, 2, 3], 2);
+   * // => [3]
    *
-   * _.shuffle([1, 2, 3, 4, 5, 6]);
-   * // => [4, 1, 6, 3, 5, 2]
-   */
-  function shuffle(array) {
-    if (!array) {
-      return [];
-    }
-    var rand,
-        index = -1,
-        length = array.length,
-        result = Array(length);
-
-    while (++index < length) {
-      rand = Math.floor(Math.random() * (index + 1));
-      result[index] = result[rand];
-      result[rand] = array[index];
-    }
-    return result;
-  }
-
-  /**
-   * Produces a new sorted array, ranked in ascending order by the results of
-   * running each element of `array` through `callback`. The `callback` is
-   * bound to `thisArg` and invoked with 3 arguments; (value, index, array). The
-   * `callback` argument may also be the name of a property to sort by (e.g. 'length').
+   * _.rest([1, 2, 3], function(num) {
+   *   return num < 3;
+   * });
+   * // => [3]
    *
-   * @static
-   * @memberOf _
-   * @category Arrays
-   * @param {Array} array The array to iterate over.
-   * @param {Function|String} callback The function called per iteration or
-   *  property name to sort by.
-   * @param {Mixed} [thisArg] The `this` binding for the callback.
-   * @returns {Array} Returns a new array of sorted values.
-   * @example
+   * var food = [
+   *   { 'name': 'banana', 'organic': true },
+   *   { 'name': 'beet',   'organic': false },
+   * ];
    *
-   * _.sortBy([1, 2, 3], function(num) { return Math.sin(num); });
-   * // => [3, 1, 2]
+   * // using "_.pluck" callback shorthand
+   * _.rest(food, 'organic');
+   * // => [{ 'name': 'beet', 'organic': false }]
    *
-   * _.sortBy([1, 2, 3], function(num) { return this.sin(num); }, Math);
-   * // => [3, 1, 2]
+   * var food = [
+   *   { 'name': 'apple',  'type': 'fruit' },
+   *   { 'name': 'banana', 'type': 'fruit' },
+   *   { 'name': 'beet',   'type': 'vegetable' }
+   * ];
    *
-   * _.sortBy(['larry', 'brendan', 'moe'], 'length');
-   * // => ['moe', 'larry', 'brendan']
+   * // using "_.where" callback shorthand
+   * _.rest(food, { 'type': 'fruit' });
+   * // => [{ 'name': 'beet', 'type': 'vegetable' }]
    */
-  function sortBy(array, callback, thisArg) {
-    if (!array) {
-      return [];
-    }
-    if (typeof callback == 'string') {
-      var prop = callback;
-      callback = function(array) { return array[prop]; };
-    } else if (thisArg) {
-      callback = iteratorBind(callback, thisArg);
-    }
-    var index = -1,
-        length = array.length,
-        result = Array(length);
-
-    while (++index < length) {
-      result[index] = {
-        'criteria': callback(array[index], index, array),
-        'value': array[index]
-      };
-    }
-    result.sort(function(left, right) {
-      var a = left.criteria,
-          b = right.criteria;
-
-      if (a === undefined) {
-        return 1;
-      }
-      if (b === undefined) {
-        return -1;
+  function rest(array, callback, thisArg) {
+    if (typeof callback != 'number' && callback != null) {
+      var n = 0,
+          index = -1,
+          length = array ? array.length : 0;
+
+      callback = createCallback(callback, thisArg);
+      while (++index < length && callback(array[index], index, array)) {
+        n++;
       }
-      return a < b ? -1 : a > b ? 1 : 0;
-    });
-
-    while (length--) {
-      result[length] = result[length].value;
+    } else {
+      n = (callback == null || thisArg) ? 1 : nativeMax(0, callback);
     }
-    return result;
+    return slice.call(array, n);
   }
 
   /**
@@ -1569,61 +2951,69 @@
    * should be inserted into `array` in order to maintain the sort order of the
    * sorted `array`. If `callback` is passed, it will be executed for `value` and
    * each element in `array` to compute their sort ranking. The `callback` is
-   * bound to `thisArg` and invoked with 1 argument; (value).
+   * bound to `thisArg` and invoked with one argument; (value).
+   *
+   * If a property name is passed for `callback`, the created "_.pluck" style
+   * callback will return the property value of the given element.
+   *
+   * If an object is passed for `callback`, the created "_.where" style callback
+   * will return `true` for elements that have the properties of the given object,
+   * else `false`.
    *
    * @static
    * @memberOf _
    * @category Arrays
    * @param {Array} array The array to iterate over.
    * @param {Mixed} value The value to evaluate.
-   * @param {Function} [callback=identity] The function called per iteration.
-   * @param {Mixed} [thisArg] The `this` binding for the callback.
+   * @param {Function|Object|String} [callback=identity] The function called per
+   *  iteration. If a property name or object is passed, it will be used to create
+   *  a "_.pluck" or "_.where" style callback, respectively.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
    * @returns {Number} Returns the index at which the value should be inserted
    *  into `array`.
    * @example
    *
-   * _.sortedIndex([20, 30, 40], 35);
+   * _.sortedIndex([20, 30, 50], 40);
+   * // => 2
+   *
+   * // using "_.pluck" callback shorthand
+   * _.sortedIndex([{ 'x': 20 }, { 'x': 30 }, { 'x': 50 }], { 'x': 40 }, 'x');
    * // => 2
    *
    * var dict = {
-   *   'wordToNumber': { 'twenty': 20, 'thirty': 30, 'thirty-five': 35, 'fourty': 40 }
+   *   'wordToNumber': { 'twenty': 20, 'thirty': 30, 'fourty': 40, 'fifty': 50 }
    * };
    *
-   * _.sortedIndex(['twenty', 'thirty', 'fourty'], 'thirty-five', function(word) {
+   * _.sortedIndex(['twenty', 'thirty', 'fifty'], 'fourty', function(word) {
    *   return dict.wordToNumber[word];
    * });
    * // => 2
    *
-   * _.sortedIndex(['twenty', 'thirty', 'fourty'], 'thirty-five', function(word) {
+   * _.sortedIndex(['twenty', 'thirty', 'fifty'], 'fourty', function(word) {
    *   return this.wordToNumber[word];
    * }, dict);
    * // => 2
    */
   function sortedIndex(array, value, callback, thisArg) {
-    if (!array) {
-      return 0;
-    }
-    var mid,
-        low = 0,
-        high = array.length;
-
-    if (callback) {
-      value = callback.call(thisArg, value);
-      while (low < high) {
-        mid = (low + high) >>> 1;
-        callback.call(thisArg, array[mid]) < value ? low = mid + 1 : high = mid;
-      }
-    } else {
-      while (low < high) {
-        mid = (low + high) >>> 1;
-        array[mid] < value ? low = mid + 1 : high = mid;
-      }
+    var low = 0,
+        high = array ? array.length : low;
+
+    // explicitly reference `identity` for better inlining in Firefox
+    callback = callback ? createCallback(callback, thisArg, 1) : identity;
+    value = callback(value);
+
+    while (low < high) {
+      var mid = (low + high) >>> 1;
+      (callback(array[mid]) < value)
+        ? low = mid + 1
+        : high = mid;
     }
     return low;
   }
 
   /**
-   * Computes the union of the passed-in arrays.
+   * Computes the union of the passed-in arrays using strict equality for
+   * comparisons, i.e. `===`.
    *
    * @static
    * @memberOf _
@@ -1637,26 +3027,22 @@
    * // => [1, 2, 3, 101, 10]
    */
   function union() {
-    var index = -1,
-        result = [],
-        flattened = concat.apply(result, arguments),
-        length = flattened.length;
-
-    while (++index < length) {
-      if (indexOf(result, flattened[index]) < 0) {
-        result.push(flattened[index]);
-      }
-    }
-    return result;
+    return uniq(concat.apply(arrayRef, arguments));
   }
 
   /**
-   * Produces a duplicate-value-free version of the `array` using strict equality
+   * Creates a duplicate-value-free version of the `array` using strict equality
    * for comparisons, i.e. `===`. If the `array` is already sorted, passing `true`
-   * for `isSorted` will run a faster algorithm. If `callback` is passed,
-   * each value of `array` is passed through a transformation `callback` before
-   * uniqueness is computed. The `callback` is bound to `thisArg` and invoked
-   * with 3 arguments; (value, index, array).
+   * for `isSorted` will run a faster algorithm. If `callback` is passed, each
+   * element of `array` is passed through a callback` before uniqueness is computed.
+   * The `callback` is bound to `thisArg` and invoked with three arguments; (value, index, array).
+   *
+   * If a property name is passed for `callback`, the created "_.pluck" style
+   * callback will return the property value of the given element.
+   *
+   * If an object is passed for `callback`, the created "_.where" style callback
+   * will return `true` for elements that have the properties of the given object,
+   * else `false`.
    *
    * @static
    * @memberOf _
@@ -1664,15 +3050,17 @@
    * @category Arrays
    * @param {Array} array The array to process.
    * @param {Boolean} [isSorted=false] A flag to indicate that the `array` is already sorted.
-   * @param {Function} [callback=identity] The function called per iteration.
-   * @param {Mixed} [thisArg] The `this` binding for the callback.
+   * @param {Function|Object|String} [callback=identity] The function called per
+   *  iteration. If a property name or object is passed, it will be used to create
+   *  a "_.pluck" or "_.where" style callback, respectively.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
    * @returns {Array} Returns a duplicate-value-free array.
    * @example
    *
    * _.uniq([1, 2, 1, 3, 1]);
    * // => [1, 2, 3]
    *
-   * _.uiq([1, 1, 2, 2, 3], true);
+   * _.uniq([1, 1, 2, 2, 3], true);
    * // => [1, 2, 3]
    *
    * _.uniq([1, 2, 1.5, 3, 2.5], function(num) { return Math.floor(num); });
@@ -1680,43 +3068,45 @@
    *
    * _.uniq([1, 2, 1.5, 3, 2.5], function(num) { return this.floor(num); }, Math);
    * // => [1, 2, 3]
+   *
+   * // using "_.pluck" callback shorthand
+   * _.uniq([{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }], 'x');
+   * // => [{ 'x': 1 }, { 'x': 2 }]
    */
   function uniq(array, isSorted, callback, thisArg) {
-    var result = [];
-    if (!array) {
-      return result;
-    }
-    var computed,
-        index = -1,
-        length = array.length,
-        seen = [];
+    var index = -1,
+        length = array ? array.length : 0,
+        result = [],
+        seen = result;
 
-    // juggle arguments
-    if (typeof isSorted == 'function') {
+    if (typeof isSorted != 'boolean' && isSorted != null) {
       thisArg = callback;
       callback = isSorted;
       isSorted = false;
     }
-    if (!callback) {
-      callback = identity;
-    } else if (thisArg) {
-      callback = iteratorBind(callback, thisArg);
+    if (callback != null) {
+      seen = [];
+      callback = createCallback(callback, thisArg);
     }
     while (++index < length) {
-      computed = callback(array[index], index, array);
+      var value = array[index],
+          computed = callback ? callback(value, index, array) : value;
+
       if (isSorted
             ? !index || seen[seen.length - 1] !== computed
             : indexOf(seen, computed) < 0
           ) {
-        seen.push(computed);
-        result.push(array[index]);
+        if (callback) {
+          seen.push(computed);
+        }
+        result.push(value);
       }
     }
     return result;
   }
 
   /**
-   * Produces a new array with all occurrences of the passed values removed using
+   * Creates an array with all occurrences of the passed values removed using
    * strict equality for comparisons, i.e. `===`.
    *
    * @static
@@ -1731,44 +3121,38 @@
    * // => [2, 3, 4]
    */
   function without(array) {
-    var result = [];
-    if (!array) {
-      return result;
-    }
-    var excluded = slice.call(arguments, 1),
-        index = -1,
-        length = array.length;
+    var index = -1,
+        length = array.length,
+        result = [];
 
     while (++index < length) {
-      if (indexOf(excluded, array[index]) < 0) {
-        result.push(array[index]);
+      var value = array[index];
+      if (indexOf(arguments, value, 1) < 0) {
+        result.push(value);
       }
     }
-    return result;
+    return result
   }
 
   /**
-   * Merges together the values of each of the arrays with the value at the
-   * corresponding position. Useful for separate data sources that are coordinated
-   * through matching array indexes. For a matrix of nested arrays, `_.zip.apply(...)`
-   * can transpose the matrix in a similar fashion.
+   * Groups the elements of each array at their corresponding indexes. Useful for
+   * separate data sources that are coordinated through matching array indexes.
+   * For a matrix of nested arrays, `_.zip.apply(...)` can transpose the matrix
+   * in a similar fashion.
    *
    * @static
    * @memberOf _
    * @category Arrays
    * @param {Array} [array1, array2, ...] Arrays to process.
-   * @returns {Array} Returns a new array of merged arrays.
+   * @returns {Array} Returns a new array of grouped elements.
    * @example
    *
-   * _.zip(['moe', 'larry', 'curly'], [30, 40, 50], [true, false, false]);
-   * // => [['moe', 30, true], ['larry', 40, false], ['curly', 50, false]]
+   * _.zip(['moe', 'larry'], [30, 40], [true, false]);
+   * // => [['moe', 30, true], ['larry', 40, false]]
    */
   function zip(array) {
-    if (!array) {
-      return [];
-    }
     var index = -1,
-        length = max(pluck(arguments, 'length')),
+        length = array ? max(pluck(arguments, 'length')) : 0,
         result = Array(length);
 
     while (++index < length) {
@@ -1777,11 +3161,48 @@
     return result;
   }
 
+  /**
+   * Creates an object composed from arrays of `keys` and `values`. Pass either
+   * a single two dimensional array, i.e. `[[key1, value1], [key2, value2]]`, or
+   * two arrays, one of `keys` and one of corresponding `values`.
+   *
+   * @static
+   * @memberOf _
+   * @alias object
+   * @category Arrays
+   * @param {Array} keys The array of keys.
+   * @param {Array} [values=[]] The array of values.
+   * @returns {Object} Returns an object composed of the given keys and
+   *  corresponding values.
+   * @example
+   *
+   * _.zipObject(['moe', 'larry'], [30, 40]);
+   * // => { 'moe': 30, 'larry': 40 }
+   */
+  function zipObject(keys, values) {
+    var index = -1,
+        length = keys ? keys.length : 0,
+        result = {};
+
+    while (++index < length) {
+      var key = keys[index];
+      if (values) {
+        result[key] = values[index];
+      } else {
+        result[key[0]] = key[1];
+      }
+    }
+    return result;
+  }
+
   /*--------------------------------------------------------------------------*/
 
   /**
-   * Creates a new function that is restricted to executing only after it is
-   * called `n` times.
+   * If `n` is greater than `0`, a function is created that is restricted to
+   * executing `func`, with the `this` binding and arguments of the created
+   * function, only after it is called `n` times. If `n` is less than `1`,
+   * `func` is executed immediately, without a `this` binding or additional
+   * arguments, and its result is returned.
    *
    * @static
    * @memberOf _
@@ -1810,99 +3231,39 @@
   }
 
   /**
-   * Creates a new function that, when called, invokes `func` with the `this`
+   * Creates a function that, when called, invokes `func` with the `this`
    * binding of `thisArg` and prepends any additional `bind` arguments to those
-   * passed to the bound function. Lazy defined methods may be bound by passing
-   * the object they are bound to as `func` and the method name as `thisArg`.
+   * passed to the bound function.
    *
    * @static
    * @memberOf _
    * @category Functions
-   * @param {Function|Object} func The function to bind or the object the method belongs to.
-   * @param {Mixed} [thisArg] The `this` binding of `func` or the method name.
+   * @param {Function} func The function to bind.
+   * @param {Mixed} [thisArg] The `this` binding of `func`.
    * @param {Mixed} [arg1, arg2, ...] Arguments to be partially applied.
    * @returns {Function} Returns the new bound function.
    * @example
    *
-   * // basic bind
    * var func = function(greeting) {
-   *   return greeting + ': ' + this.name;
+   *   return greeting + ' ' + this.name;
    * };
    *
    * func = _.bind(func, { 'name': 'moe' }, 'hi');
    * func();
-   * // => 'hi: moe'
-   *
-   * // lazy bind
-   * var object = {
-   *   'name': 'moe',
-   *   'greet': function(greeting) {
-   *     return greeting + ': ' + this.name;
-   *   }
-   * };
-   *
-   * var func = _.bind(object, 'greet', 'hi');
-   * func();
-   * // => 'hi: moe'
-   *
-   * object.greet = function(greeting) {
-   *   return greeting + ', ' + this.name + '!';
-   * };
-   *
-   * func();
-   * // => 'hi, moe!'
+   * // => 'hi moe'
    */
   function bind(func, thisArg) {
-    var methodName,
-        isFunc = toString.call(func) == funcClass;
-
-    // juggle arguments
-    if (!isFunc) {
-      methodName = thisArg;
-      thisArg = func;
-    }
-    // use if `Function#bind` is faster
-    else if (nativeBind) {
-      return nativeBind.call.apply(nativeBind, arguments);
-    }
-
-    var partialArgs = slice.call(arguments, 2);
-
-    function bound() {
-      // `Function#bind` spec
-      // http://es5.github.com/#x15.3.4.5
-      var args = arguments,
-          thisBinding = thisArg;
-
-      if (!isFunc) {
-        func = thisArg[methodName];
-      }
-      if (partialArgs.length) {
-        args = args.length
-          ? concat.apply(partialArgs, args)
-          : partialArgs;
-      }
-      if (this instanceof bound) {
-        // get `func` instance if `bound` is invoked in a `new` expression
-        noop.prototype = func.prototype;
-        thisBinding = new noop;
-
-        // mimic the constructor's `return` behavior
-        // http://es5.github.com/#x13.2.2
-        var result = func.apply(thisBinding, args);
-        return objectTypes[typeof result] && result !== null
-          ? result
-          : thisBinding
-      }
-      return func.apply(thisBinding, args);
-    }
-
-    return bound;
+    // use `Function#bind` if it exists and is fast
+    // (in V8 `Function#bind` is slower except when partially applied)
+    return support.fastBind || (nativeBind && arguments.length > 2)
+      ? nativeBind.call.apply(nativeBind, arguments)
+      : createBound(func, thisArg, slice.call(arguments, 2));
   }
 
   /**
    * Binds methods on `object` to `object`, overwriting the existing method.
-   * If no method names are provided, all the function properties of `object`
+   * Method names may be specified as individual arguments or as arrays of method
+   * names. If no method names are provided, all the function properties of `object`
    * will be bound.
    *
    * @static
@@ -1910,37 +3271,35 @@
    * @category Functions
    * @param {Object} object The object to bind and assign the bound methods to.
    * @param {String} [methodName1, methodName2, ...] Method names on the object to bind.
-   * @returns {Object} Returns the `object`.
+   * @returns {Object} Returns `object`.
    * @example
    *
-   * var buttonView = {
-   *  'label': 'lodash',
-   *  'onClick': function() { alert('clicked: ' + this.label); },
-   *  'onHover': function() { console.log('hovering: ' + this.label); }
+   * var view = {
+   *  'label': 'docs',
+   *  'onClick': function() { alert('clicked ' + this.label); }
    * };
    *
-   * _.bindAll(buttonView);
-   * jQuery('#lodash_button').on('click', buttonView.onClick);
-   * // => When the button is clicked, `this.label` will have the correct value
+   * _.bindAll(view);
+   * jQuery('#docs').on('click', view.onClick);
+   * // => alerts 'clicked docs', when the button is clicked
    */
   function bindAll(object) {
-    var funcs = arguments,
-        index = 1;
+    var funcs = concat.apply(arrayRef, arguments),
+        index = funcs.length > 1 ? 0 : (funcs = functions(object), -1),
+        length = funcs.length;
 
-    if (funcs.length == 1) {
-      index = 0;
-      funcs = functions(object);
-    }
-    for (var length = funcs.length; index < length; index++) {
-      object[funcs[index]] = bind(object[funcs[index]], object);
+    while (++index < length) {
+      var key = funcs[index];
+      object[key] = bind(object[key], object);
     }
     return object;
   }
 
   /**
-   * Creates a new function that is the composition of the passed functions,
+   * Creates a function that is the composition of the passed functions,
    * where each function consumes the return value of the function that follows.
-   * In math terms, composing the functions `f()`, `g()`, and `h()` produces `f(g(h()))`.
+   * For example, composing the functions `f()`, `g()`, and `h()` produces `f(g(h()))`.
+   * Each function is executed with the `this` binding of the composed function.
    *
    * @static
    * @memberOf _
@@ -1949,11 +3308,11 @@
    * @returns {Function} Returns the new composed function.
    * @example
    *
-   * var greet = function(name) { return 'hi: ' + name; };
+   * var greet = function(name) { return 'hi ' + name; };
    * var exclaim = function(statement) { return statement + '!'; };
    * var welcome = _.compose(exclaim, greet);
    * welcome('moe');
-   * // => 'hi: moe!'
+   * // => 'hi moe!'
    */
   function compose() {
     var funcs = arguments;
@@ -1969,7 +3328,99 @@
   }
 
   /**
-   * Creates a new function that will delay the execution of `func` until after
+   * Produces a callback bound to an optional `thisArg`. If `func` is a property
+   * name, the created callback will return the property value for a given element.
+   * If `func` is an object, the created callback will return `true` for elements
+   * that contain the equivalent object properties, otherwise it will return `false`.
+   *
+   * Note: All Lo-Dash methods, that accept a `callback` argument, use `_.createCallback`.
+   *
+   * @static
+   * @memberOf _
+   * @category Functions
+   * @param {Mixed} [func=identity] The value to convert to a callback.
+   * @param {Mixed} [thisArg] The `this` binding of the created callback.
+   * @param {Number} [argCount=3] The number of arguments the callback accepts.
+   * @returns {Function} Returns a callback function.
+   * @example
+   *
+   * var stooges = [
+   *   { 'name': 'moe', 'age': 40 },
+   *   { 'name': 'larry', 'age': 50 }
+   * ];
+   *
+   * // wrap to create custom callback shorthands
+   * _.createCallback = _.wrap(_.createCallback, function(func, callback, thisArg) {
+   *   var match = /^(.+?)__([gl]t)(.+)$/.exec(callback);
+   *   return !match ? func(callback, thisArg) : function(object) {
+   *     return match[2] == 'gt' ? object[match[1]] > match[3] : object[match[1]] < match[3];
+   *   };
+   * });
+   *
+   * _.filter(stooges, 'age__gt45');
+   * // => [{ 'name': 'larry', 'age': 50 }]
+   *
+   * // create mixins with support for "_.pluck" and "_.where" callback shorthands
+   * _.mixin({
+   *   'toLookup': function(collection, callback, thisArg) {
+   *     callback = _.createCallback(callback, thisArg);
+   *     return _.reduce(collection, function(result, value, index, collection) {
+   *       return (result[callback(value, index, collection)] = value, result);
+   *     }, {});
+   *   }
+   * });
+   *
+   * _.toLookup(stooges, 'name');
+   * // => { 'moe': { 'name': 'moe', 'age': 40 }, 'larry': { 'name': 'larry', 'age': 50 } }
+   */
+  function createCallback(func, thisArg, argCount) {
+    if (func == null) {
+      return identity;
+    }
+    var type = typeof func;
+    if (type != 'function') {
+      if (type != 'object') {
+        return function(object) {
+          return object[func];
+        };
+      }
+      var props = keys(func);
+      return function(object) {
+        var length = props.length,
+            result = false;
+        while (length--) {
+          if (!(result = object[props[length]] === func[props[length]])) {
+            break;
+          }
+        }
+        return result;
+      };
+    }
+    if (typeof thisArg != 'undefined') {
+      if (argCount === 1) {
+        return function(value) {
+          return func.call(thisArg, value);
+        };
+      }
+      if (argCount === 2) {
+        return function(a, b) {
+          return func.call(thisArg, a, b);
+        };
+      }
+      if (argCount === 4) {
+        return function(accumulator, value, index, collection) {
+          return func.call(thisArg, accumulator, value, index, collection);
+        };
+      }
+      return function(value, index, collection) {
+        return func.call(thisArg, value, index, collection);
+      };
+    }
+    return func;
+  }
+
+  /**
+   * Creates a function that will delay the execution of `func` until after
    * `wait` milliseconds have elapsed since the last time it was invoked. Pass
    * `true` for `immediate` to cause debounce to invoke `func` on the leading,
    * instead of the trailing, edge of the `wait` timeout. Subsequent calls to
@@ -1995,12 +3446,11 @@
         timeoutId;
 
     function delayed() {
-      timeoutId = undefined;
+      timeoutId = null;
       if (!immediate) {
-        func.apply(thisArg, args);
+        result = func.apply(thisArg, args);
       }
     }
-
     return function() {
       var isImmediate = immediate && !timeoutId;
       args = arguments;
@@ -2017,52 +3467,53 @@
   }
 
   /**
-   * Executes the `func` function after `wait` milliseconds. Additional arguments
-   * are passed to `func` when it is invoked.
+   * Defers executing the `func` function until the current call stack has cleared.
+   * Additional arguments will be passed to `func` when it is invoked.
    *
    * @static
    * @memberOf _
    * @category Functions
-   * @param {Function} func The function to delay.
-   * @param {Number} wait The number of milliseconds to delay execution.
+   * @param {Function} func The function to defer.
    * @param {Mixed} [arg1, arg2, ...] Arguments to invoke the function with.
-   * @returns {Number} Returns the `setTimeout` timeout id.
+   * @returns {Number} Returns the timer id.
    * @example
    *
-   * var log = _.bind(console.log, console);
-   * _.delay(log, 1000, 'logged later');
-   * // => 'logged later' (Appears after one second.)
+   * _.defer(function() { alert('deferred'); });
+   * // returns from the function before `alert` is called
    */
-  function delay(func, wait) {
-    var args = slice.call(arguments, 2);
-    return setTimeout(function() { return func.apply(undefined, args); }, wait);
+  function defer(func) {
+    var args = slice.call(arguments, 1);
+    return setTimeout(function() { func.apply(undefined, args); }, 1);
   }
 
   /**
-   * Defers executing the `func` function until the current call stack has cleared.
-   * Additional arguments are passed to `func` when it is invoked.
+   * Executes the `func` function after `wait` milliseconds. Additional arguments
+   * will be passed to `func` when it is invoked.
    *
    * @static
    * @memberOf _
    * @category Functions
-   * @param {Function} func The function to defer.
+   * @param {Function} func The function to delay.
+   * @param {Number} wait The number of milliseconds to delay execution.
    * @param {Mixed} [arg1, arg2, ...] Arguments to invoke the function with.
-   * @returns {Number} Returns the `setTimeout` timeout id.
+   * @returns {Number} Returns the timer id.
    * @example
    *
-   * _.defer(function() { alert('deferred'); });
-   * // returns from the function before `alert` is called
+   * var log = _.bind(console.log, console);
+   * _.delay(log, 1000, 'logged later');
+   * // => 'logged later' (Appears after one second.)
    */
-  function defer(func) {
-    var args = slice.call(arguments, 1);
-    return setTimeout(function() { return func.apply(undefined, args); }, 1);
+  function delay(func, wait) {
+    var args = slice.call(arguments, 2);
+    return setTimeout(function() { func.apply(undefined, args); }, wait);
   }
 
   /**
-   * Creates a new function that memoizes the result of `func`. If `resolver` is
+   * Creates a function that memoizes the result of `func`. If `resolver` is
    * passed, it will be used to determine the cache key for storing the result
    * based on the arguments passed to the memoized function. By default, the first
-   * argument passed to the memoized function is used as the cache key.
+   * argument passed to the memoized function is used as the cache key. The `func`
+   * is executed with the `this` binding of the memoized function.
    *
    * @static
    * @memberOf _
@@ -2079,16 +3530,17 @@
   function memoize(func, resolver) {
     var cache = {};
     return function() {
-      var prop = resolver ? resolver.apply(this, arguments) : arguments[0];
-      return hasOwnProperty.call(cache, prop)
-        ? cache[prop]
-        : (cache[prop] = func.apply(this, arguments));
+      var key = String(resolver ? resolver.apply(this, arguments) : arguments[0]);
+      return hasOwnProperty.call(cache, key)
+        ? cache[key]
+        : (cache[key] = func.apply(this, arguments));
     };
   }
 
   /**
-   * Creates a new function that is restricted to one execution. Repeat calls to
-   * the function will return the value of the first call.
+   * Creates a function that is restricted to execute `func` once. Repeat calls to
+   * the function will return the value of the first call. The `func` is executed
+   * with the `this` binding of the created function.
    *
    * @static
    * @memberOf _
@@ -2100,11 +3552,11 @@
    * var initialize = _.once(createApplication);
    * initialize();
    * initialize();
-   * // Application is only created once.
+   * // `initialize` executes `createApplication` once
    */
   function once(func) {
-    var result,
-        ran = false;
+    var ran,
+        result;
 
     return function() {
       if (ran) {
@@ -2112,15 +3564,17 @@
       }
       ran = true;
       result = func.apply(this, arguments);
+
+      // clear the `func` variable so the function may be garbage collected
+      func = null;
       return result;
     };
   }
 
   /**
-   * Creates a new function that, when called, invokes `func` with any additional
-   * `partial` arguments prepended to those passed to the partially applied
-   * function. This method is similar `bind`, except it does **not** alter the
-   * `this` binding.
+   * Creates a function that, when called, invokes `func` with any additional
+   * `partial` arguments prepended to those passed to the new function. This
+   * method is similar to `_.bind`, except it does **not** alter the `this` binding.
    *
    * @static
    * @memberOf _
@@ -2130,35 +3584,21 @@
    * @returns {Function} Returns the new partially applied function.
    * @example
    *
-   * var greet = function(greeting, name) { return greeting + ': ' + name; };
+   * var greet = function(greeting, name) { return greeting + ' ' + name; };
    * var hi = _.partial(greet, 'hi');
    * hi('moe');
-   * // => 'hi: moe'
+   * // => 'hi moe'
    */
   function partial(func) {
-    var args = slice.call(arguments, 1),
-        argsLength = args.length;
-
-    return function() {
-      var result,
-          others = arguments;
-
-      if (others.length) {
-        args.length = argsLength;
-        push.apply(args, others);
-      }
-      result = args.length == 1 ? func.call(this, args[0]) : func.apply(this, args);
-      args.length = argsLength;
-      return result;
-    };
+    return createBound(func, slice.call(arguments, 1));
   }
 
   /**
-   * Creates a new function that, when executed, will only call the `func`
-   * function at most once per every `wait` milliseconds. If the throttled function
-   * is invoked more than once, `func` will also be called on the trailing edge
-   * of the `wait` timeout. Subsequent calls to the throttled function will
-   * return the result of the last `func` call.
+   * Creates a function that, when executed, will only call the `func`
+   * function at most once per every `wait` milliseconds. If the throttled
+   * function is invoked more than once during the `wait` timeout, `func` will
+   * also be called on the trailing edge of the timeout. Subsequent calls to the
+   * throttled function will return the result of the last `func` call.
    *
    * @static
    * @memberOf _
@@ -2180,55 +3620,54 @@
 
     function trailingCall() {
       lastCalled = new Date;
-      timeoutId = undefined;
-      func.apply(thisArg, args);
+      timeoutId = null;
+      result = func.apply(thisArg, args);
     }
-
     return function() {
       var now = new Date,
-          remain = wait - (now - lastCalled);
+          remaining = wait - (now - lastCalled);
 
       args = arguments;
       thisArg = this;
 
-      if (remain <= 0) {
+      if (remaining <= 0) {
+        clearTimeout(timeoutId);
+        timeoutId = null;
         lastCalled = now;
         result = func.apply(thisArg, args);
       }
       else if (!timeoutId) {
-        timeoutId = setTimeout(trailingCall, remain);
+        timeoutId = setTimeout(trailingCall, remaining);
       }
       return result;
     };
   }
 
   /**
-   * Create a new function that passes the `func` function to the `wrapper`
-   * function as its first argument. Additional arguments are appended to those
-   * passed to the `wrapper` function.
+   * Creates a function that passes `value` to the `wrapper` function as its
+   * first argument. Additional arguments passed to the function are appended
+   * to those passed to the `wrapper` function. The `wrapper` is executed with
+   * the `this` binding of the created function.
    *
    * @static
    * @memberOf _
    * @category Functions
-   * @param {Function} func The function to wrap.
+   * @param {Mixed} value The value to wrap.
    * @param {Function} wrapper The wrapper function.
-   * @param {Mixed} [arg1, arg2, ...] Arguments to append to those passed to the wrapper.
    * @returns {Function} Returns the new function.
    * @example
    *
-   * var hello = function(name) { return 'hello: ' + name; };
+   * var hello = function(name) { return 'hello ' + name; };
    * hello = _.wrap(hello, function(func) {
    *   return 'before, ' + func('moe') + ', after';
    * });
    * hello();
-   * // => 'before, hello: moe, after'
+   * // => 'before, hello moe, after'
    */
-  function wrap(func, wrapper) {
+  function wrap(value, wrapper) {
     return function() {
-      var args = [func];
-      if (arguments.length) {
-        push.apply(args, arguments);
-      }
+      var args = [value];
+      push.apply(args, arguments);
       return wrapper.apply(this, args);
     };
   }
@@ -2236,755 +3675,8 @@
   /*--------------------------------------------------------------------------*/
 
   /**
-   * Create a shallow clone of the `value`. Any nested objects or arrays will be
-   * assigned by reference and not cloned.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Mixed} value The value to clone.
-   * @returns {Mixed} Returns the cloned `value`.
-   * @example
-   *
-   * _.clone({ 'name': 'moe' });
-   * // => { 'name': 'moe' };
-   */
-  function clone(value) {
-    return objectTypes[typeof value] && value !== null
-      ? (isArray(value) ? value.slice() : extend({}, value))
-      : value;
-  }
-
-  /**
-   * Assigns missing properties in `object` with default values from the defaults
-   * objects. As soon as a property is set, additional defaults of the same
-   * property will be ignored.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Object} object The object to populate.
-   * @param {Object} [defaults1, defaults2, ...] The defaults objects to apply to `object`.
-   * @returns {Object} Returns `object`.
-   * @example
-   *
-   * var iceCream = { 'flavor': 'chocolate' };
-   * _.defaults(iceCream, { 'flavor': 'vanilla', 'sprinkles': 'rainbow' });
-   * // => { 'flavor': 'chocolate', 'sprinkles': 'rainbow' }
-   */
-  var defaults = createIterator(extendIteratorOptions, {
-    'inLoop': 'if (object[index] == undefined)' + extendIteratorOptions.inLoop
-  });
-
-  /**
-   * Copies enumerable properties from the source objects to the `destination` object.
-   * Subsequent sources will overwrite propery assignments of previous sources.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Object} object The destination object.
-   * @param {Object} [source1, source2, ...] The source objects.
-   * @returns {Object} Returns the destination object.
-   * @example
-   *
-   * _.extend({ 'name': 'moe' }, { 'age': 40 });
-   * // => { 'name': 'moe', 'age': 40 }
-   */
-  var extend = createIterator(extendIteratorOptions);
-
-  /**
-   * Iterates over `object`'s own and inherited enumerable properties, executing
-   * the `callback` for each property. The `callback` is bound to `thisArg` and
-   * invoked with 3 arguments; (value, key, object).
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Object} object The object to iterate over.
-   * @param {Function} callback The function called per iteration.
-   * @param {Mixed} [thisArg] The `this` binding for the callback.
-   * @returns {Object} Returns the `object`.
-   * @example
-   *
-   * function Dog(name) {
-   *   this.name = name;
-   * }
-   *
-   * Dog.prototype.bark = function() {
-   *   alert('Woof, woof!');
-   * };
-   *
-   * _.forIn(new Dog('Dagny'), function(value, key) {
-   *   alert(key);
-   * });
-   * // => alerts 'name' and 'bark' (order is not guaranteed)
-   */
-  var forIn = createIterator(baseIteratorOptions, forEachIteratorOptions, forOwnIteratorOptions, {
-    'useHas': false
-  });
-
-  /**
-   * Iterates over `object`'s own enumerable properties, executing the `callback`
-   * for each property. The `callback` is bound to `thisArg` and invoked with 3
-   * arguments; (value, key, object).
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Object} object The object to iterate over.
-   * @param {Function} callback The function called per iteration.
-   * @param {Mixed} [thisArg] The `this` binding for the callback.
-   * @returns {Object} Returns the `object`.
-   * @example
-   *
-   * _.forOwn({ '0': 'zero', '1': 'one', 'length': 2 }, function(num, key) {
-   *   alert(key);
-   * });
-   * // => alerts '0', '1', and 'length' (order is not guaranteed)
-   */
-  var forOwn = createIterator(baseIteratorOptions, forEachIteratorOptions, forOwnIteratorOptions);
-
-  /**
-   * Produces a sorted array of the enumerable properties, own and inherited,
-   * of `object` that have function values.
-   *
-   * @static
-   * @memberOf _
-   * @alias methods
-   * @category Objects
-   * @param {Object} object The object to inspect.
-   * @returns {Array} Returns a new array of property names that have function values.
-   * @example
-   *
-   * _.functions(_);
-   * // => ['all', 'any', 'bind', 'bindAll', 'clone', 'compact', 'compose', ...]
-   */
-  var functions = createIterator({
-    'args': 'object',
-    'init': '[]',
-    'useHas': false,
-    'inLoop': 'if (toString.call(object[index]) == funcClass) result.push(index)',
-    'bottom': 'result.sort()'
-  });
-
-  /**
-   * Checks if the specified object `property` exists and is a direct property,
-   * instead of an inherited property.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Object} object The object to check.
-   * @param {String} property The property to check for.
-   * @returns {Boolean} Returns `true` if key is a direct property, else `false`.
-   * @example
-   *
-   * _.has({ 'a': 1, 'b': 2, 'c': 3 }, 'b');
-   * // => true
-   */
-  function has(object, property) {
-    return hasOwnProperty.call(object, property);
-  }
-
-  /**
-   * Checks if a `value` is an `arguments` object.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Mixed} value The value to check.
-   * @returns {Boolean} Returns `true` if the `value` is an `arguments` object, else `false`.
-   * @example
-   *
-   * (function() { return _.isArguments(arguments); })(1, 2, 3);
-   * // => true
-   *
-   * _.isArguments([1, 2, 3]);
-   * // => false
-   */
-  var isArguments = function(value) {
-    return toString.call(value) == '[object Arguments]';
-  };
-  // fallback for browser like IE < 9 which detect `arguments` as `[object Object]`
-  if (!isArguments(arguments)) {
-    isArguments = function(value) {
-      return !!(value && hasOwnProperty.call(value, 'callee'));
-    };
-  }
-
-  /**
-   * Checks if a `value` is an array.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Mixed} value The value to check.
-   * @returns {Boolean} Returns `true` if the `value` is an array, else `false`.
-   * @example
-   *
-   * (function() { return _.isArray(arguments); })();
-   * // => false
-   *
-   * _.isArray([1, 2, 3]);
-   * // => true
-   */
-  var isArray = nativeIsArray || function(value) {
-    return toString.call(value) == arrayClass;
-  };
-
-  /**
-   * Checks if a `value` is a boolean (`true` or `false`) value.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Mixed} value The value to check.
-   * @returns {Boolean} Returns `true` if the `value` is a boolean value, else `false`.
-   * @example
-   *
-   * _.isBoolean(null);
-   * // => false
-   */
-  function isBoolean(value) {
-    return value === true || value === false || toString.call(value) == boolClass;
-  }
-
-  /**
-   * Checks if a `value` is a date.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Mixed} value The value to check.
-   * @returns {Boolean} Returns `true` if the `value` is a date, else `false`.
-   * @example
-   *
-   * _.isDate(new Date);
-   * // => true
-   */
-  function isDate(value) {
-    return toString.call(value) == dateClass;
-  }
-
-  /**
-   * Checks if a `value` is a DOM element.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Mixed} value The value to check.
-   * @returns {Boolean} Returns `true` if the `value` is a DOM element, else `false`.
-   * @example
-   *
-   * _.isElement(document.body);
-   * // => true
-   */
-  function isElement(value) {
-    return !!(value && value.nodeType == 1);
-  }
-
-  /**
-   * Checks if a `value` is empty. Arrays or strings with a length of `0` and
-   * objects with no own enumerable properties are considered "empty".
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Array|Object|String} value The value to inspect.
-   * @returns {Boolean} Returns `true` if the `value` is empty, else `false`.
-   * @example
-   *
-   * _.isEmpty([1, 2, 3]);
-   * // => false
-   *
-   * _.isEmpty({});
-   * // => true
-   */
-  var isEmpty = createIterator({
-    'args': 'value',
-    'init': 'true',
-    'top':
-      'var className = toString.call(value);\n' +
-      'if (className == arrayClass || className == stringClass) return !value.length',
-    'inLoop': {
-      'object': 'return false'
-    }
-  });
-
-  /**
-   * Performs a deep comparison between two values to determine if they are
-   * equivalent to each other.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Mixed} a The value to compare.
-   * @param {Mixed} b The other value to compare.
-   * @param {Array} [stack] Internally used to keep track of "seen" objects to
-   *  avoid circular references.
-   * @returns {Boolean} Returns `true` if the values are equvalent, else `false`.
-   * @example
-   *
-   * var moe = { 'name': 'moe', 'luckyNumbers': [13, 27, 34] };
-   * var clone = { 'name': 'moe', 'luckyNumbers': [13, 27, 34] };
-   *
-   * moe == clone;
-   * // => false
-   *
-   * _.isEqual(moe, clone);
-   * // => true
-   */
-  function isEqual(a, b, stack) {
-    stack || (stack = []);
-
-    // exit early for identical values
-    if (a === b) {
-      // treat `+0` vs. `-0` as not equal
-      return a !== 0 || (1 / a == 1 / b);
-    }
-    // a strict comparison is necessary because `null == undefined`
-    if (a == undefined || b == undefined) {
-      return a === b;
-    }
-    // unwrap any wrapped objects
-    if (a._chain) {
-      a = a._wrapped;
-    }
-    if (b._chain) {
-      b = b._wrapped;
-    }
-    // invoke a custom `isEqual` method if one is provided
-    if (a.isEqual && toString.call(a.isEqual) == funcClass) {
-      return a.isEqual(b);
-    }
-    if (b.isEqual && toString.call(b.isEqual) == funcClass) {
-      return b.isEqual(a);
-    }
-    // compare [[Class]] names
-    var className = toString.call(a);
-    if (className != toString.call(b)) {
-      return false;
-    }
-    switch (className) {
-      // strings, numbers, dates, and booleans are compared by value
-      case stringClass:
-        // primitives and their corresponding object instances are equivalent;
-        // thus, `'5'` is quivalent to `new String('5')`
-        return a == String(b);
-
-      case numberClass:
-        // treat `NaN` vs. `NaN` as equal
-        return a != +a
-          ? b != +b
-          // but treat `+0` vs. `-0` as not equal
-          : (a == 0 ? (1 / a == 1 / b) : a == +b);
-
-      case boolClass:
-      case dateClass:
-        // coerce dates and booleans to numeric values, dates to milliseconds and booleans to 1 or 0;
-        // treat invalid dates coerced to `NaN` as not equal
-        return +a == +b;
-
-      // regexps are compared by their source and flags
-      case regexpClass:
-        return a.source == b.source &&
-               a.global == b.global &&
-               a.multiline == b.multiline &&
-               a.ignoreCase == b.ignoreCase;
-    }
-    if (typeof a != 'object' || typeof b != 'object') {
-      return false;
-    }
-    // Assume equality for cyclic structures. The algorithm for detecting cyclic
-    // structures is adapted from ES 5.1 section 15.12.3, abstract operation `JO`.
-    var length = stack.length;
-    while (length--) {
-      // Linear search. Performance is inversely proportional to the number of
-      // unique nested structures.
-      if (stack[length] == a) {
-        return true;
-      }
-    }
-
-    var index = -1,
-        result = true,
-        size = 0;
-
-    // add the first collection to the stack of traversed objects
-    stack.push(a);
-
-    // recursively compare objects and arrays
-    if (className == arrayClass) {
-      // compare array lengths to determine if a deep comparison is necessary
-      size = a.length;
-      result = size == b.length;
-
-      if (result) {
-        // deep compare the contents, ignoring non-numeric properties
-        while (size--) {
-          if (!(result = isEqual(a[size], b[size], stack))) {
-            break;
-          }
-        }
-      }
-    } else {
-      // objects with different constructors are not equivalent
-      if ('constructor' in a != 'constructor' in b || a.constructor != b.constructor) {
-        return false;
-      }
-      // deep compare objects.
-      for (var prop in a) {
-        if (hasOwnProperty.call(a, prop)) {
-          // count the number of properties.
-          size++;
-          // deep compare each property value.
-          if (!(result = hasOwnProperty.call(b, prop) && isEqual(a[prop], b[prop], stack))) {
-            break;
-          }
-        }
-      }
-      // ensure both objects have the same number of properties
-      if (result) {
-        for (prop in b) {
-          // Adobe's JS engine, embedded in applications like InDesign, has a
-          // bug that causes `!size--` to throw an error so it must be wrapped
-          // in parentheses.
-          // https://github.com/documentcloud/underscore/issues/355
-          if (hasOwnProperty.call(b, prop) && !(size--)) {
-            break;
-          }
-        }
-        result = !size;
-      }
-      // handle JScript [[DontEnum]] bug
-      if (result && hasDontEnumBug) {
-        while (++index < 7) {
-          prop = shadowed[index];
-          if (hasOwnProperty.call(a, prop)) {
-            if (!(result = hasOwnProperty.call(b, prop) && isEqual(a[prop], b[prop], stack))) {
-              break;
-            }
-          }
-        }
-      }
-    }
-    // remove the first collection from the stack of traversed objects
-    stack.pop();
-    return result;
-  }
-
-  /**
-   * Checks if a `value` is a finite number.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Mixed} value The value to check.
-   * @returns {Boolean} Returns `true` if the `value` is a finite number, else `false`.
-   * @example
-   *
-   * _.isFinite(-101);
-   * // => true
-   *
-   * _.isFinite('10');
-   * // => false
-   *
-   * _.isFinite(Infinity);
-   * // => false
-   */
-  function isFinite(value) {
-    return nativeIsFinite(value) && toString.call(value) == numberClass;
-  }
-
-  /**
-   * Checks if a `value` is a function.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Mixed} value The value to check.
-   * @returns {Boolean} Returns `true` if the `value` is a function, else `false`.
-   * @example
-   *
-   * _.isFunction(''.concat);
-   * // => true
-   */
-  function isFunction(value) {
-    return toString.call(value) == funcClass;
-  }
-
-  /**
-   * Checks if a `value` is the language type of Object.
-   * (e.g. arrays, functions, objects, regexps, `new Number(0)`, and `new String('')`)
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Mixed} value The value to check.
-   * @returns {Boolean} Returns `true` if the `value` is an object, else `false`.
-   * @example
-   *
-   * _.isObject({});
-   * // => true
-   *
-   * _.isObject(1);
-   * // => false
-   */
-  function isObject(value) {
-    // check if the value is the ECMAScript language type of Object
-    // http://es5.github.com/#x8
-    return objectTypes[typeof value] && value !== null;
-  }
-
-  /**
-   * Checks if a `value` is `NaN`.
-   * Note: This is not the same as native `isNaN`, which will return true for
-   * `undefined` and other values. See http://es5.github.com/#x15.1.2.4.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Mixed} value The value to check.
-   * @returns {Boolean} Returns `true` if the `value` is `NaN`, else `false`.
-   * @example
-   *
-   * _.isNaN(NaN);
-   * // => true
-   *
-   * _.isNaN(new Number(NaN));
-   * // => true
-   *
-   * isNaN(undefined);
-   * // => true
-   *
-   * _.isNaN(undefined);
-   * // => false
-   */
-  function isNaN(value) {
-    // `NaN` as a primitive is the only value that is not equal to itself
-    // (perform the [[Class]] check first to avoid errors with some host objects in IE)
-    return toString.call(value) == numberClass && value != +value
-  }
-
-  /**
-   * Checks if a `value` is `null`.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Mixed} value The value to check.
-   * @returns {Boolean} Returns `true` if the `value` is `null`, else `false`.
-   * @example
-   *
-   * _.isNull(null);
-   * // => true
-   *
-   * _.isNull(undefined);
-   * // => false
-   */
-  function isNull(value) {
-    return value === null;
-  }
-
-  /**
-   * Checks if a `value` is a number.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Mixed} value The value to check.
-   * @returns {Boolean} Returns `true` if the `value` is a number, else `false`.
-   * @example
-   *
-   * _.isNumber(8.4 * 5;
-   * // => true
-   */
-  function isNumber(value) {
-    return toString.call(value) == numberClass;
-  }
-
-  /**
-   * Checks if a `value` is a regular expression.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Mixed} value The value to check.
-   * @returns {Boolean} Returns `true` if the `value` is a regular expression, else `false`.
-   * @example
-   *
-   * _.isRegExp(/moe/);
-   * // => true
-   */
-  function isRegExp(value) {
-    return toString.call(value) == regexpClass;
-  }
-
-  /**
-   * Checks if a `value` is a string.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Mixed} value The value to check.
-   * @returns {Boolean} Returns `true` if the `value` is a string, else `false`.
-   * @example
-   *
-   * _.isString('moe');
-   * // => true
-   */
-  function isString(value) {
-    return toString.call(value) == stringClass;
-  }
-
-  /**
-   * Checks if a `value` is `undefined`.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Mixed} value The value to check.
-   * @returns {Boolean} Returns `true` if the `value` is `undefined`, else `false`.
-   * @example
-   *
-   * _.isUndefined(void 0);
-   * // => true
-   */
-  function isUndefined(value) {
-    return value === undefined;
-  }
-
-  /**
-   * Produces an array of object`'s own enumerable property names.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Object} object The object to inspect.
-   * @returns {Array} Returns a new array of property names.
-   * @example
-   *
-   * _.keys({ 'one': 1, 'two': 2, 'three': 3 });
-   * // => ['one', 'two', 'three'] (order is not guaranteed)
-   */
-  var keys = !nativeKeys ? shimKeys : function(object) {
-    // avoid iterating over the `prototype` property
-    return typeof object == 'function'
-      ? shimKeys(object)
-      : nativeKeys(object);
-  };
-
-  /**
-   * Creates an object composed of the specified properties. Property names may
-   * be specified as individual arguments or as arrays of property names.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Object} object The object to pluck.
-   * @param {Object} [prop1, prop2, ...] The properties to pick.
-   * @returns {Object} Returns an object composed of the picked properties.
-   * @example
-   *
-   * _.pick({ 'name': 'moe', 'age': 40, 'userid': 'moe1' }, 'name', 'age');
-   * // => { 'name': 'moe', 'age': 40 }
-   */
-  function pick(object) {
-    var prop,
-        index = 0,
-        props = concat.apply(ArrayProto, arguments),
-        length = props.length,
-        result = {};
-
-    // start `index` at `1` to skip `object`
-    while (++index < length) {
-      prop = props[index];
-      if (prop in object) {
-        result[prop] = object[prop];
-      }
-    }
-    return result;
-  }
-
-  /**
-   * Gets the size of `value` by returning `value.length` if `value` is a string
-   * or array, or the number of own enumerable properties if `value` is an object.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Array|Object|String} value The value to inspect.
-   * @returns {Number} Returns `value.length` if `value` is a string or array,
-   *  or the number of own enumerable properties if `value` is an object.
-   * @example
-   *
-   * _.size([1, 2]);
-   * // => 2
-   *
-   * _.size({ 'one': 1, 'two': 2, 'three': 3 });
-   * // => 3
-   *
-   * _.size('curly');
-   * // => 5
-   */
-  function size(value) {
-    var className = toString.call(value);
-    return className == arrayClass || className == stringClass
-      ? value.length
-      : keys(value).length;
-  }
-
-  /**
-   * Invokes `interceptor` with the `value` as the first argument, and then returns
-   * `value`. The primary purpose of this method is to "tap into" a method chain,
-   * in order to performoperations on intermediate results within the chain.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Mixed} value The value to pass to `callback`.
-   * @param {Function} interceptor The function to invoke.
-   * @returns {Mixed} Returns `value`.
-   * @example
-   *
-   * _.chain([1,2,3,200])
-   *  .filter(function(num) { return num % 2 == 0; })
-   *  .tap(alert)
-   *  .map(function(num) { return num * num })
-   *  .value();
-   * // => // [2, 200] (alerted)
-   * // => [4, 40000]
-   */
-  function tap(value, interceptor) {
-    interceptor(value);
-    return value;
-  }
-
-  /**
-   * Produces an array of `object`'s own enumerable property values.
-   *
-   * @static
-   * @memberOf _
-   * @category Objects
-   * @param {Object} object The object to inspect.
-   * @returns {Array} Returns a new array of property values.
-   * @example
-   *
-   * _.values({ 'one': 1, 'two': 2, 'three': 3 });
-   * // => [1, 2, 3]
-   */
-  var values = createIterator({
-    'args': 'object',
-    'init': '[]',
-    'inLoop': 'result.push(object[index])'
-  });
-
-  /*--------------------------------------------------------------------------*/
-
-  /**
-   * Escapes a string for inclusion in HTML, replacing `&`, `<`, `"`, and `'`
-   * characters.
+   * Converts the characters `&`, `<`, `>`, `"`, and `'` in `string` to their
+   * corresponding HTML entities.
    *
    * @static
    * @memberOf _
@@ -2993,16 +3685,15 @@
    * @returns {String} Returns the escaped string.
    * @example
    *
-   * _.escape('Curly, Larry & Moe');
-   * // => "Curly, Larry &amp; Moe"
+   * _.escape('Moe, Larry & Curly');
+   * // => 'Moe, Larry &amp; Curly'
    */
   function escape(string) {
-    return string == null ? '' : (string + '').replace(reUnescapedHtml, escapeHtmlChar);
+    return string == null ? '' : String(string).replace(reUnescapedHtml, escapeHtmlChar);
   }
 
   /**
    * This function returns the first argument passed to it.
-   * Note: It is used throughout Lo-Dash as a default callback.
    *
    * @static
    * @memberOf _
@@ -3035,25 +3726,24 @@
    *   }
    * });
    *
-   * _.capitalize('curly');
-   * // => 'Curly'
+   * _.capitalize('moe');
+   * // => 'Moe'
    *
-   * _('larry').capitalize();
-   * // => 'Larry'
+   * _('moe').capitalize();
+   * // => 'Moe'
    */
   function mixin(object) {
     forEach(functions(object), function(methodName) {
       var func = lodash[methodName] = object[methodName];
 
-      LoDash.prototype[methodName] = function() {
-        var args = [this._wrapped];
-        if (arguments.length) {
-          push.apply(args, arguments);
-        }
+      lodash.prototype[methodName] = function() {
+        var args = [this.__wrapped__];
+        push.apply(args, arguments);
+
         var result = func.apply(lodash, args);
-        if (this._chain) {
-          result = new LoDash(result);
-          result._chain = true;
+        if (this.__chain__) {
+          result = new lodashWrapper(result);
+          result.__chain__ = true;
         }
         return result;
       };
@@ -3078,15 +3768,46 @@
   }
 
   /**
-   * Resolves the value of `property` on `object`. If `property` is a function
-   * it will be invoked and its result returned, else the property value is
-   * returned. If `object` is falsey, then `null` is returned.
+   * Produces a random number between `min` and `max` (inclusive). If only one
+   * argument is passed, a number between `0` and the given number will be returned.
+   *
+   * @static
+   * @memberOf _
+   * @category Utilities
+   * @param {Number} [min=0] The minimum possible value.
+   * @param {Number} [max=1] The maximum possible value.
+   * @returns {Number} Returns a random number.
+   * @example
+   *
+   * _.random(0, 5);
+   * // => a number between 0 and 5
+   *
+   * _.random(5);
+   * // => also a number between 0 and 5
+   */
+  function random(min, max) {
+    if (min == null && max == null) {
+      max = 1;
+    }
+    min = +min || 0;
+    if (max == null) {
+      max = min;
+      min = 0;
+    }
+    return min + floor(nativeRandom() * ((+max || 0) - min + 1));
+  }
+
+  /**
+   * Resolves the value of `property` on `object`. If `property` is a function,
+   * it will be invoked with the `this` binding of `object` and its result returned,
+   * else the property value is returned. If `object` is falsey, then `undefined`
+   * is returned.
    *
    * @static
    * @memberOf _
    * @category Utilities
    * @param {Object} object The object to inspect.
-   * @param {String} property The property to get the result of.
+   * @param {String} property The property to get the value of.
    * @returns {Mixed} Returns the resolved value.
    * @example
    *
@@ -3104,19 +3825,25 @@
    * // => 'nonsense'
    */
   function result(object, property) {
-    // based on Backbone's private `getValue` function
-    // https://github.com/documentcloud/backbone/blob/0.9.2/backbone.js#L1419-1424
-    if (!object) {
-      return null;
-    }
-    var value = object[property];
-    return toString.call(value) == funcClass ? object[property]() : value;
+    var value = object ? object[property] : null;
+    return isFunction(value) ? object[property]() : value;
   }
 
   /**
-   * A micro-templating method, similar to John Resig's implementation.
-   * Lo-Dash templating handles arbitrary delimiters, preserves whitespace, and
-   * correctly escapes quotes within interpolated code.
+   * A micro-templating method that handles arbitrary delimiters, preserves
+   * whitespace, and correctly escapes quotes within interpolated code.
+   *
+   * Note: In the development build, `_.template` utilizes sourceURLs for easier
+   * debugging. See http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl
+   *
+   * Note: Lo-Dash may be used in Chrome extensions by either creating a `lodash csp`
+   * build and using precompiled templates, or loading Lo-Dash in a sandbox.
+   *
+   * For more information on precompiling templates see:
+   * http://lodash.com/#custom-builds
+   *
+   * For more information on Chrome extension sandboxes see:
+   * http://developer.chrome.com/stable/extensions/sandboxingEval.html
    *
    * @static
    * @memberOf _
@@ -3124,177 +3851,202 @@
    * @param {String} text The template text.
    * @param {Obect} data The data object used to populate the text.
    * @param {Object} options The options object.
+   *  escape - The "escape" delimiter regexp.
+   *  evaluate - The "evaluate" delimiter regexp.
+   *  interpolate - The "interpolate" delimiter regexp.
+   *  sourceURL - The sourceURL of the template's compiled source.
+   *  variable - The data object variable name.
    * @returns {Function|String} Returns a compiled function when no `data` object
    *  is given, else it returns the interpolated text.
    * @example
    *
-   * // using compiled template
-   * var compiled = _.template('hello: <%= name %>');
+   * // using a compiled template
+   * var compiled = _.template('hello <%= name %>');
    * compiled({ 'name': 'moe' });
-   * // => 'hello: moe'
+   * // => 'hello moe'
+   *
+   * var list = '<% _.forEach(people, function(name) { %><li><%= name %></li><% }); %>';
+   * _.template(list, { 'people': ['moe', 'larry'] });
+   * // => '<li>moe</li><li>larry</li>'
    *
-   * var list = '<% _.forEach(people, function(name) { %> <li><%= name %></li> <% }); %>';
-   * _.template(list, { 'people': ['moe', 'curly', 'larry'] });
-   * // => '<li>moe</li><li>curly</li><li>larry</li>'
+   * // using the "escape" delimiter to escape HTML in data property values
+   * _.template('<b><%- value %></b>', { 'value': '<script>' });
+   * // => '<b>&lt;script&gt;</b>'
    *
-   * var template = _.template('<b><%- value %></b>');
-   * template({ 'value': '<script>' });
-   * // => '<b>&lt;script></b>'
+   * // using the ES6 delimiter as an alternative to the default "interpolate" delimiter
+   * _.template('hello ${ name }', { 'name': 'curly' });
+   * // => 'hello curly'
    *
-   * // using `print`
-   * var compiled = _.template('<% print("Hello " + epithet); %>');
-   * compiled({ 'epithet': 'stooge' });
-   * // => 'Hello stooge.'
+   * // using the internal `print` function in "evaluate" delimiters
+   * _.template('<% print("hello " + epithet); %>!', { 'epithet': 'stooge' });
+   * // => 'hello stooge!'
    *
-   * // using custom template settings
+   * // using custom template delimiters
    * _.templateSettings = {
-   *   'interpolate': /\{\{(.+?)\}\}/g
+   *   'interpolate': /{{([\s\S]+?)}}/g
    * };
    *
-   * var template = _.template('Hello {{ name }}!');
-   * template({ 'name': 'Mustache' });
-   * // => 'Hello Mustache!'
-   *
-   * // using the `variable` option
-   * _.template('<%= data.hasWith %>', { 'hasWith': 'no' }, { 'variable': 'data' });
-   * // => 'no'
+   * _.template('hello {{ name }}!', { 'name': 'mustache' });
+   * // => 'hello mustache!'
+   *
+   * // using the `sourceURL` option to specify a custom sourceURL for the template
+   * var compiled = _.template('hello <%= name %>', null, { 'sourceURL': '/basic/greeting.jst' });
+   * compiled(data);
+   * // => find the source of "greeting.jst" under the Sources tab or Resources panel of the web inspector
+   *
+   * // using the `variable` option to ensure a with-statement isn't used in the compiled template
+   * var compiled = _.template('hi <%= data.name %>!', null, { 'variable': 'data' });
+   * compiled.source;
+   * // => function(data) {
+   *   var __t, __p = '', __e = _.escape;
+   *   __p += 'hi ' + ((__t = ( data.name )) == null ? '' : __t) + '!';
+   *   return __p;
+   * }
    *
-   * // using the `source` property
-   * <script>
-   *   JST.project = <%= _.template(jstText).source %>;
-   * </script>
+   * // using the `source` property to inline compiled templates for meaningful
+   * // line numbers in error messages and a stack trace
+   * fs.writeFileSync(path.join(cwd, 'jst.js'), '\
+   *   var JST = {\
+   *     "main": ' + _.template(mainText).source + '\
+   *   };\
+   * ');
    */
   function template(text, data, options) {
-    options || (options = {});
+    text || (text = '');
+    options = defaults({}, options, lodash.templateSettings);
 
-    var result,
-        defaults = lodash.templateSettings,
-        escapeDelimiter = options.escape,
-        evaluateDelimiter = options.evaluate,
-        interpolateDelimiter = options.interpolate,
+    var index = 0,
+        source = "__p += '",
         variable = options.variable;
 
-    // use template defaults if no option is provided
-    if (escapeDelimiter == null) {
-      escapeDelimiter = defaults.escape;
-    }
-    if (evaluateDelimiter == null) {
-      evaluateDelimiter = defaults.evaluate;
-    }
-    if (interpolateDelimiter == null) {
-      interpolateDelimiter = defaults.interpolate;
-    }
-
-    // tokenize delimiters to avoid escaping them
-    if (escapeDelimiter) {
-      text = text.replace(escapeDelimiter, tokenizeEscape);
-    }
-    if (interpolateDelimiter) {
-      text = text.replace(interpolateDelimiter, tokenizeInterpolate);
-    }
-    if (evaluateDelimiter) {
-      text = text.replace(evaluateDelimiter, tokenizeEvaluate);
-    }
+    var reDelimiters = RegExp(
+      (options.escape || reNoMatch).source + '|' +
+      (options.interpolate || reNoMatch).source + '|' +
+      (options.evaluate || reNoMatch).source + '|$'
+    , 'g');
 
-    // escape characters that cannot be included in string literals and
-    // detokenize delimiter code snippets
-    text = "__p='" + text
-      .replace(reUnescapedString, escapeStringChar)
-      .replace(reToken, detokenize) + "';\n";
-
-    // clear stored code snippets
-    tokenized.length = 0;
+    text.replace(reDelimiters, function(match, escapeValue, interpolateValue, evaluateValue, offset) {
+      source += text.slice(index, offset).replace(reUnescapedString, escapeStringChar);
+      if (escapeValue) {
+        source += "' +\n_.escape(" + escapeValue + ") +\n'";
+      }
+      if (evaluateValue) {
+        source += "';\n" + evaluateValue + ";\n__p += '";
+      }
+      if (interpolateValue) {
+        source += "' +\n((__t = (" + interpolateValue + ")) == null ? '' : __t) +\n'";
+      }
+      index = offset + match.length;
+      return match;
+    });
 
-    // if `options.variable` is not specified, add `data` to the top of the scope chain
+    source += "';\n";
     if (!variable) {
-      variable = defaults.variable;
-      text = 'with (' + variable + ' || {}) {\n' + text + '\n}\n';
+      variable = 'obj';
+      source = 'with (' + variable + ' || {}) {\n' + source + '\n}\n';
     }
-
-    text = 'function(' + variable + ') {\n' +
-      'var __p, __t, __j = Array.prototype.join;\n' +
-      'function print() { __p += __j.call(arguments, \'\') }\n' +
-      text +
+    source = 'function(' + variable + ') {\n' +
+      "var __t, __p = '', __j = Array.prototype.join;\n" +
+      "function print() { __p += __j.call(arguments, '') }\n" +
+      source +
       'return __p\n}';
 
-    // add a sourceURL for easier debugging
-    // http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl
-    if (useSourceURL) {
-      text += '\n//@ sourceURL=/lodash/template/source[' + (templateCounter++) + ']';
+    try {
+      var result = Function('_', 'return ' + source)(lodash);
+    } catch(e) {
+      e.source = source;
+      throw e;
     }
-
-    result = Function('_', 'return ' + text)(lodash);
-
     if (data) {
       return result(data);
     }
-    // provide the compiled function's source via its `toString()` method, in
-    // supported environments, or the `source` property as a convenience for
-    // build time precompilation
-    result.source = text;
+    result.source = source;
     return result;
   }
 
   /**
-   * Executes the `callback` function `n` times. The `callback` is bound to
-   * `thisArg` and invoked with 1 argument; (index).
+   * Executes the `callback` function `n` times, returning an array of the results
+   * of each `callback` execution. The `callback` is bound to `thisArg` and invoked
+   * with one argument; (index).
    *
    * @static
    * @memberOf _
    * @category Utilities
    * @param {Number} n The number of times to execute the callback.
    * @param {Function} callback The function called per iteration.
-   * @param {Mixed} [thisArg] The `this` binding for the callback.
+   * @param {Mixed} [thisArg] The `this` binding of `callback`.
+   * @returns {Array} Returns a new array of the results of each `callback` execution.
    * @example
    *
-   * _.times(3, function() { genie.grantWish(); });
-   * // => calls `genie.grantWish()` 3 times
+   * var diceRolls = _.times(3, _.partial(_.random, 1, 6));
+   * // => [3, 6, 4]
+   *
+   * _.times(3, function(n) { mage.castSpell(n); });
+   * // => calls `mage.castSpell(n)` three times, passing `n` of `0`, `1`, and `2` respectively
    *
-   * _.times(3, function() { this.grantWish(); }, genie);
-   * // => also calls `genie.grantWish()` 3 times
+   * _.times(3, function(n) { this.cast(n); }, mage);
+   * // => also calls `mage.castSpell(n)` three times
    */
   function times(n, callback, thisArg) {
-    var index = -1;
-    if (thisArg) {
-      while (++index < n) {
-        callback.call(thisArg, index);
-      }
-    } else {
-      while (++index < n) {
-        callback(index);
-      }
+    var index = -1,
+        result = Array(n > -1 ? n : 0);
+
+    while (++index < n) {
+      result[index] = callback.call(thisArg, index);
     }
+    return result;
   }
 
   /**
-   * Generates a unique id. If `prefix` is passed, the id will be appended to it.
+   * The opposite of `_.escape`, this method converts the HTML entities
+   * `&amp;`, `&lt;`, `&gt;`, `&quot;`, and `&#39;` in `string` to their
+   * corresponding characters.
    *
    * @static
    * @memberOf _
    * @category Utilities
-   * @param {String} [prefix] The value to prefix the id with.
-   * @returns {Number|String} Returns a numeric id if no prefix is passed, else
-   *  a string id may be returned.
+   * @param {String} string The string to unescape.
+   * @returns {String} Returns the unescaped string.
+   * @example
+   *
+   * _.unescape('Moe, Larry &amp; Curly');
+   * // => 'Moe, Larry & Curly'
+   */
+  function unescape(string) {
+    return string == null ? '' : String(string).replace(reEscapedHtml, unescapeHtmlChar);
+  }
+
+  /**
+   * Generates a unique ID. If `prefix` is passed, the ID will be appended to it.
+   *
+   * @static
+   * @memberOf _
+   * @category Utilities
+   * @param {String} [prefix] The value to prefix the ID with.
+   * @returns {String} Returns the unique ID.
    * @example
    *
    * _.uniqueId('contact_');
    * // => 'contact_104'
+   *
+   * _.uniqueId();
+   * // => '105'
    */
   function uniqueId(prefix) {
-    var id = idCounter++;
+    var id = ++idCounter + '';
     return prefix ? prefix + id : id;
   }
 
   /*--------------------------------------------------------------------------*/
 
   /**
-   * Wraps the value in a `lodash` chainable object.
+   * Creates a `lodash` object that wraps the given `value`.
    *
    * @static
    * @memberOf _
    * @category Chaining
    * @param {Mixed} value The value to wrap.
-   * @returns {Object} Returns the `lodash` chainable object.
+   * @returns {Object} Returns the wrapper object.
    * @example
    *
    * var stooges = [
@@ -3306,92 +4058,168 @@
    * var youngest = _.chain(stooges)
    *     .sortBy(function(stooge) { return stooge.age; })
    *     .map(function(stooge) { return stooge.name + ' is ' + stooge.age; })
-   *     .first()
-   *     .value();
+   *     .first();
    * // => 'moe is 40'
    */
   function chain(value) {
-    value = new LoDash(value);
-    value._chain = true;
+    value = new lodashWrapper(value);
+    value.__chain__ = true;
     return value;
   }
 
   /**
-   * Extracts the value from a wrapped chainable object.
+   * Invokes `interceptor` with the `value` as the first argument, and then
+   * returns `value`. The purpose of this method is to "tap into" a method chain,
+   * in order to perform operations on intermediate results within the chain.
+   *
+   * @static
+   * @memberOf _
+   * @category Chaining
+   * @param {Mixed} value The value to pass to `interceptor`.
+   * @param {Function} interceptor The function to invoke.
+   * @returns {Mixed} Returns `value`.
+   * @example
+   *
+   * _([1, 2, 3, 4])
+   *  .filter(function(num) { return num % 2 == 0; })
+   *  .tap(alert)
+   *  .map(function(num) { return num * num; })
+   *  .value();
+   * // => // [2, 4] (alerted)
+   * // => [4, 16]
+   */
+  function tap(value, interceptor) {
+    interceptor(value);
+    return value;
+  }
+
+  /**
+   * Enables method chaining on the wrapper object.
    *
    * @name chain
    * @memberOf _
    * @category Chaining
-   * @returns {Mixed} Returns the wrapped object.
+   * @returns {Mixed} Returns the wrapper object.
    * @example
    *
-   * _([1, 2, 3]).value();
-   * // => [1, 2, 3]
+   * var sum = _([1, 2, 3])
+   *     .chain()
+   *     .reduce(function(sum, num) { return sum + num; })
+   *     .value()
+   * // => 6`
    */
   function wrapperChain() {
-    this._chain = true;
+    this.__chain__ = true;
     return this;
   }
 
   /**
-   * Extracts the value from a wrapped chainable object.
+   * Produces the `toString` result of the wrapped value.
    *
-   * @name value
+   * @name toString
    * @memberOf _
    * @category Chaining
-   * @returns {Mixed} Returns the wrapped object.
+   * @returns {String} Returns the string result.
    * @example
    *
-   * _([1, 2, 3]).value();
-   * // => [1, 2, 3]
+   * _([1, 2, 3]).toString();
+   * // => '1,2,3'
    */
-  function wrapperValue() {
-    return this._wrapped;
+  function wrapperToString() {
+    return String(this.__wrapped__);
   }
 
-  /*--------------------------------------------------------------------------*/
-
   /**
-   * The semantic version number.
+   * Extracts the wrapped value.
    *
-   * @static
+   * @name valueOf
    * @memberOf _
-   * @type String
+   * @alias value
+   * @category Chaining
+   * @returns {Mixed} Returns the wrapped value.
+   * @example
+   *
+   * _([1, 2, 3]).valueOf();
+   * // => [1, 2, 3]
    */
-  lodash.VERSION = '0.3.1';
+  function wrapperValueOf() {
+    return this.__wrapped__;
+  }
+
+  /*--------------------------------------------------------------------------*/
 
-  // assign static methods
+  // add functions that return wrapped values when chaining
   lodash.after = after;
   lodash.bind = bind;
   lodash.bindAll = bindAll;
-  lodash.chain = chain;
-  lodash.clone = clone;
   lodash.compact = compact;
   lodash.compose = compose;
-  lodash.contains = contains;
+  lodash.countBy = countBy;
   lodash.debounce = debounce;
   lodash.defaults = defaults;
   lodash.defer = defer;
   lodash.delay = delay;
   lodash.difference = difference;
-  lodash.escape = escape;
-  lodash.every = every;
-  lodash.extend = extend;
   lodash.filter = filter;
-  lodash.find = find;
-  lodash.first = first;
   lodash.flatten = flatten;
   lodash.forEach = forEach;
-  lodash.forIn = forIn;
-  lodash.forOwn = forOwn;
   lodash.functions = functions;
   lodash.groupBy = groupBy;
-  lodash.has = has;
-  lodash.identity = identity;
-  lodash.indexOf = indexOf;
   lodash.initial = initial;
   lodash.intersection = intersection;
+  lodash.invert = invert;
   lodash.invoke = invoke;
+  lodash.keys = keys;
+  lodash.map = map;
+  lodash.max = max;
+  lodash.memoize = memoize;
+  lodash.min = min;
+  lodash.omit = omit;
+  lodash.once = once;
+  lodash.pairs = pairs;
+  lodash.partial = partial;
+  lodash.pick = pick;
+  lodash.pluck = pluck;
+  lodash.range = range;
+  lodash.reject = reject;
+  lodash.rest = rest;
+  lodash.shuffle = shuffle;
+  lodash.sortBy = sortBy;
+  lodash.tap = tap;
+  lodash.throttle = throttle;
+  lodash.times = times;
+  lodash.toArray = toArray;
+  lodash.union = union;
+  lodash.uniq = uniq;
+  lodash.values = values;
+  lodash.where = where;
+  lodash.without = without;
+  lodash.wrap = wrap;
+  lodash.zip = zip;
+
+  // add aliases
+  lodash.collect = map;
+  lodash.drop = rest;
+  lodash.each = forEach;
+  lodash.extend = assign;
+  lodash.methods = functions;
+  lodash.object = zipObject;
+  lodash.select = filter;
+  lodash.tail = rest;
+  lodash.unique = uniq;
+
+  /*--------------------------------------------------------------------------*/
+
+  // add functions that return unwrapped values when chaining
+  lodash.clone = clone;
+  lodash.contains = contains;
+  lodash.escape = escape;
+  lodash.every = every;
+  lodash.find = find;
+  lodash.findWhere = findWhere;
+  lodash.has = has;
+  lodash.identity = identity;
+  lodash.indexOf = indexOf;
   lodash.isArguments = isArguments;
   lodash.isArray = isArray;
   lodash.isBoolean = isBoolean;
@@ -3408,112 +4236,85 @@
   lodash.isRegExp = isRegExp;
   lodash.isString = isString;
   lodash.isUndefined = isUndefined;
-  lodash.keys = keys;
-  lodash.last = last;
   lodash.lastIndexOf = lastIndexOf;
-  lodash.map = map;
-  lodash.max = max;
-  lodash.memoize = memoize;
-  lodash.min = min;
   lodash.mixin = mixin;
   lodash.noConflict = noConflict;
-  lodash.once = once;
-  lodash.partial = partial;
-  lodash.pick = pick;
-  lodash.pluck = pluck;
-  lodash.range = range;
+  lodash.random = random;
   lodash.reduce = reduce;
   lodash.reduceRight = reduceRight;
-  lodash.reject = reject;
-  lodash.rest = rest;
   lodash.result = result;
-  lodash.shuffle = shuffle;
   lodash.size = size;
   lodash.some = some;
-  lodash.sortBy = sortBy;
   lodash.sortedIndex = sortedIndex;
-  lodash.tap = tap;
   lodash.template = template;
-  lodash.throttle = throttle;
-  lodash.times = times;
-  lodash.toArray = toArray;
-  lodash.union = union;
-  lodash.uniq = uniq;
+  lodash.unescape = unescape;
   lodash.uniqueId = uniqueId;
-  lodash.values = values;
-  lodash.without = without;
-  lodash.wrap = wrap;
-  lodash.zip = zip;
 
-  // assign aliases
+  // add aliases
   lodash.all = every;
   lodash.any = some;
-  lodash.collect = map;
   lodash.detect = find;
-  lodash.each = forEach;
   lodash.foldl = reduce;
   lodash.foldr = reduceRight;
-  lodash.head = first;
   lodash.include = contains;
   lodash.inject = reduce;
-  lodash.methods = functions;
-  lodash.select = filter;
-  lodash.tail = rest;
-  lodash.take = first;
-  lodash.unique = uniq;
 
-  // add pseudo private properties used and removed during the build process
-  lodash._iteratorTemplate = iteratorTemplate;
-  lodash._shimKeys = shimKeys;
+  /*--------------------------------------------------------------------------*/
+
+  // add functions capable of returning wrapped and unwrapped values when chaining
+  lodash.first = first;
+  lodash.last = last;
+
+  // add aliases
+  lodash.take = first;
+  lodash.head = first;
 
   /*--------------------------------------------------------------------------*/
 
-  // assign private `LoDash` constructor's prototype
-  LoDash.prototype = lodash.prototype;
+  lodash.chain = chain;
+
+  /**
+   * The semantic version number.
+   *
+   * @static
+   * @memberOf _
+   * @type String
+   */
+  lodash.VERSION = '1.1.1';
 
-  // add all static functions to `LoDash.prototype`
+  // add functions to `lodash.prototype`
   mixin(lodash);
 
-  // add `LoDash.prototype.chain` after calling `mixin()` to avoid overwriting
-  // it with the wrapped `lodash.chain`
-  LoDash.prototype.chain = wrapperChain;
-  LoDash.prototype.value = wrapperValue;
+  // add "Chaining" functions to the wrapper
+  lodash.prototype.chain = wrapperChain;
+  lodash.prototype.value = wrapperValueOf;
 
-  // add all mutator Array functions to the wrapper.
+  // add `Array` mutator functions to the wrapper
   forEach(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(methodName) {
-    var func = ArrayProto[methodName];
-
-    LoDash.prototype[methodName] = function() {
-      var value = this._wrapped;
+    var func = arrayRef[methodName];
+    lodash.prototype[methodName] = function() {
+      var value = this.__wrapped__;
       func.apply(value, arguments);
 
-      // IE compatibility mode and IE < 9 have buggy Array `shift()` and `splice()`
-      // functions that fail to remove the last element, `value[0]`, of
-      // array-like objects even though the `length` property is set to `0`.
-      // The `shift()` method is buggy in IE 8 compatibility mode, while `splice()`
-      // is buggy regardless of mode in IE < 9 and buggy in compatibility mode in IE 9.
-      if (value.length === 0) {
+      // avoid array-like object bugs with `Array#shift` and `Array#splice`
+      // in Firefox < 10 and IE < 9
+      if (!support.spliceObjects && value.length === 0) {
         delete value[0];
       }
-      if (this._chain) {
-        value = new LoDash(value);
-        value._chain = true;
-      }
-      return value;
+      return this;
     };
   });
 
-  // add all accessor Array functions to the wrapper.
+  // add `Array` accessor functions to the wrapper
   forEach(['concat', 'join', 'slice'], function(methodName) {
-    var func = ArrayProto[methodName];
-
-    LoDash.prototype[methodName] = function() {
-      var value = this._wrapped,
+    var func = arrayRef[methodName];
+    lodash.prototype[methodName] = function() {
+      var value = this.__wrapped__,
           result = func.apply(value, arguments);
 
-      if (this._chain) {
-        result = new LoDash(result);
-        result._chain = true;
+      if (this.__chain__) {
+        result = new lodashWrapper(result);
+        result.__chain__ = true;
       }
       return result;
     };
@@ -3537,10 +4338,10 @@
     });
   }
   // check for `exports` after `define` in case a build optimizer adds an `exports` object
-  else if (freeExports) {
+  else if (freeExports && !freeExports.nodeType) {
     // in Node.js or RingoJS v0.8.0+
-    if (typeof module == 'object' && module && module.exports == freeExports) {
-      (module.exports = lodash)._ = lodash;
+    if (freeModule) {
+      (freeModule.exports = lodash)._ = lodash;
     }
     // in Narwhal or RingoJS v0.7.0-
     else {