Bump to v3.10.0.

README.md

@@ -1,4 +1,4 @@
-# lodash v3.9.2
+# lodash v3.10.0
 
 The [modern build](https://github.com/lodash/lodash/wiki/Build-Differences) of [lodash](https://lodash.com/) exported as [AMD](https://github.com/amdjs/amdjs-api/wiki/AMD) modules.
 
@@ -13,8 +13,8 @@ $ lodash modern exports=amd -d -o ./main.js
 Using bower or volo:
 
 ```bash
-$ bower i lodash#3.9.2-amd
-$ volo add lodash/3.9.2-amd
+$ bower i lodash#3.10.0-amd
+$ volo add lodash/3.10.0-amd
 ```
 
 Defining a build as `'lodash'`.

array/chunk.js

@@ -1,10 +1,9 @@
 define(['../internal/baseSlice', '../internal/isIterateeCall'], function(baseSlice, isIterateeCall) {
 
-  /** Native method references. */
-  var ceil = Math.ceil;
-
   /* Native method references for those with the same name as other `lodash` methods. */
-  var nativeMax = Math.max;
+  var nativeCeil = Math.ceil,
+      nativeFloor = Math.floor,
+      nativeMax = Math.max;
 
   /**
    * Creates an array of elements split into groups the length of `size`.
@@ -30,12 +29,12 @@ define(['../internal/baseSlice', '../internal/isIterateeCall'], function(baseSli
     if (guard ? isIterateeCall(array, size, guard) : size == null) {
       size = 1;
     } else {
-      size = nativeMax(+size || 1, 1);
+      size = nativeMax(nativeFloor(size) || 1, 1);
     }
     var index = 0,
         length = array ? array.length : 0,
         resIndex = -1,
-        result = Array(ceil(length / size));
+        result = Array(nativeCeil(length / size));
 
     while (index < length) {
       result[++resIndex] = baseSlice(array, index, (index += size));

array/difference.js

@@ -1,8 +1,8 @@
-define(['../internal/baseDifference', '../internal/baseFlatten', '../internal/isArrayLike', '../function/restParam'], function(baseDifference, baseFlatten, isArrayLike, restParam) {
+define(['../internal/baseDifference', '../internal/baseFlatten', '../internal/isArrayLike', '../internal/isObjectLike', '../function/restParam'], function(baseDifference, baseFlatten, isArrayLike, isObjectLike, restParam) {
 
   /**
    * Creates an array of unique `array` values not included in the other
-   * provided arrays using [`SameValueZero`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-samevaluezero)
+   * provided arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
    * for equality comparisons.
    *
    * @static
@@ -17,7 +17,7 @@ define(['../internal/baseDifference', '../internal/baseFlatten', '../internal/is
    * // => [1, 3]
    */
   var difference = restParam(function(array, values) {
-    return isArrayLike(array)
+    return (isObjectLike(array) && isArrayLike(array))
       ? baseDifference(array, baseFlatten(values, false, true))
       : [];
   });

array/indexOf.js

@@ -5,7 +5,7 @@ define(['../internal/baseIndexOf', '../internal/binaryIndex'], function(baseInde
 
   /**
    * Gets the index at which the first occurrence of `value` is found in `array`
-   * using [`SameValueZero`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-samevaluezero)
+   * using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
    * for equality comparisons. If `fromIndex` is negative, it is used as the offset
    * from the end of `array`. If `array` is sorted providing `true` for `fromIndex`
    * performs a faster binary search.
@@ -39,10 +39,9 @@ define(['../internal/baseIndexOf', '../internal/binaryIndex'], function(baseInde
     if (typeof fromIndex == 'number') {
       fromIndex = fromIndex < 0 ? nativeMax(length + fromIndex, 0) : fromIndex;
     } else if (fromIndex) {
-      var index = binaryIndex(array, value),
-          other = array[index];
-
-      if (value === value ? (value === other) : (other !== other)) {
+      var index = binaryIndex(array, value);
+      if (index < length &&
+          (value === value ? (value === array[index]) : (array[index] !== array[index]))) {
         return index;
       }
       return -1;

array/intersection.js

@@ -2,7 +2,7 @@ define(['../internal/baseIndexOf', '../internal/cacheIndexOf', '../internal/crea
 
   /**
    * Creates an array of unique values that are included in all of the provided
-   * arrays using [`SameValueZero`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-samevaluezero)
+   * arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
    * for equality comparisons.
    *
    * @static

array/pull.js

@@ -8,7 +8,7 @@ define(['../internal/baseIndexOf'], function(baseIndexOf) {
 
   /**
    * Removes all provided values from `array` using
-   * [`SameValueZero`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-samevaluezero)
+   * [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
    * for equality comparisons.
    *
    * **Note:** Unlike `_.without`, this method mutates `array`.

array/union.js

@@ -2,7 +2,7 @@ define(['../internal/baseFlatten', '../internal/baseUniq', '../function/restPara
 
   /**
    * Creates an array of unique values, in order, from all of the provided arrays
-   * using [`SameValueZero`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-samevaluezero)
+   * using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
    * for equality comparisons.
    *
    * @static

array/uniq.js

@@ -1,8 +1,11 @@
 define(['../internal/baseCallback', '../internal/baseUniq', '../internal/isIterateeCall', '../internal/sortedUniq'], function(baseCallback, baseUniq, isIterateeCall, sortedUniq) {
 
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
   /**
    * Creates a duplicate-free version of an array, using
-   * [`SameValueZero`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-samevaluezero)
+   * [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
    * for equality comparisons, in which only the first occurence of each element
    * is kept. Providing `true` for `isSorted` performs a faster search algorithm
    * for sorted arrays. If an iteratee function is provided it is invoked for
@@ -56,7 +59,7 @@ define(['../internal/baseCallback', '../internal/baseUniq', '../internal/isItera
     }
     if (isSorted != null && typeof isSorted != 'boolean') {
       thisArg = iteratee;
-      iteratee = isIterateeCall(array, isSorted, thisArg) ? null : isSorted;
+      iteratee = isIterateeCall(array, isSorted, thisArg) ? undefined : isSorted;
       isSorted = false;
     }
     iteratee = iteratee == null ? iteratee : baseCallback(iteratee, thisArg, 3);

array/without.js

@@ -2,7 +2,7 @@ define(['../internal/baseDifference', '../internal/isArrayLike', '../function/re
 
   /**
    * Creates an array excluding all provided values using
-   * [`SameValueZero`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-samevaluezero)
+   * [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
    * for equality comparisons.
    *
    * @static

array/xor.js

@@ -1,4 +1,4 @@
-define(['../internal/baseDifference', '../internal/baseUniq', '../internal/isArrayLike'], function(baseDifference, baseUniq, isArrayLike) {
+define(['../internal/arrayPush', '../internal/baseDifference', '../internal/baseUniq', '../internal/isArrayLike'], function(arrayPush, baseDifference, baseUniq, isArrayLike) {
 
   /**
    * Creates an array of unique values that is the [symmetric difference](https://en.wikipedia.org/wiki/Symmetric_difference)
@@ -22,7 +22,7 @@ define(['../internal/baseDifference', '../internal/baseUniq', '../internal/isArr
       var array = arguments[index];
       if (isArrayLike(array)) {
         var result = result
-          ? baseDifference(result, array).concat(baseDifference(array, result))
+          ? arrayPush(baseDifference(result, array), baseDifference(array, result))
           : array;
       }
     }

chain.js

@@ -1,7 +1,8 @@
-define(['./chain/chain', './chain/commit', './chain/lodash', './chain/plant', './chain/reverse', './chain/run', './chain/tap', './chain/thru', './chain/toJSON', './chain/toString', './chain/value', './chain/valueOf', './chain/wrapperChain'], function(chain, commit, lodash, plant, reverse, run, tap, thru, toJSON, toString, value, valueOf, wrapperChain) {
+define(['./chain/chain', './chain/commit', './chain/concat', './chain/lodash', './chain/plant', './chain/reverse', './chain/run', './chain/tap', './chain/thru', './chain/toJSON', './chain/toString', './chain/value', './chain/valueOf', './chain/wrapperChain'], function(chain, commit, concat, lodash, plant, reverse, run, tap, thru, toJSON, toString, value, valueOf, wrapperChain) {
   return {
     'chain': chain,
     'commit': commit,
+    'concat': concat,
     'lodash': lodash,
     'plant': plant,
     'reverse': reverse,

chain/concat.js

@@ -0,0 +1,3 @@
+define(["./wrapperConcat"], function(wrapperConcat) {
+  return wrapperConcat;
+});

chain/lodash.js

@@ -9,15 +9,16 @@ define(['../internal/LazyWrapper', '../internal/LodashWrapper', '../internal/bas
   /**
    * Creates a `lodash` object which wraps `value` to enable implicit chaining.
    * Methods that operate on and return arrays, collections, and functions can
-   * be chained together. Methods that return a boolean or single value will
-   * automatically end the chain returning the unwrapped value. Explicit chaining
-   * may be enabled using `_.chain`. The execution of chained methods is lazy,
-   * that is, execution is deferred until `_#value` is implicitly or explicitly
-   * called.
+   * be chained together. Methods that retrieve a single value or may return a
+   * primitive value will automatically end the chain returning the unwrapped
+   * value. Explicit chaining may be enabled using `_.chain`. The execution of
+   * chained methods is lazy, that is, execution is deferred until `_#value`
+   * is implicitly or explicitly called.
    *
    * Lazy evaluation allows several methods to support shortcut fusion. Shortcut
-   * fusion is an optimization that merges iteratees to avoid creating intermediate
-   * arrays and reduce the number of iteratee executions.
+   * fusion is an optimization strategy which merge iteratee calls; this can help
+   * to avoid the creation of intermediate data structures and greatly reduce the
+   * number of iteratee executions.
    *
    * Chaining is supported in custom builds as long as the `_#value` method is
    * directly or indirectly included in the build.
@@ -40,36 +41,37 @@ define(['../internal/LazyWrapper', '../internal/LodashWrapper', '../internal/bas
    * The chainable wrapper methods are:
    * `after`, `ary`, `assign`, `at`, `before`, `bind`, `bindAll`, `bindKey`,
    * `callback`, `chain`, `chunk`, `commit`, `compact`, `concat`, `constant`,
-   * `countBy`, `create`, `curry`, `debounce`, `defaults`, `defer`, `delay`,
-   * `difference`, `drop`, `dropRight`, `dropRightWhile`, `dropWhile`, `fill`,
-   * `filter`, `flatten`, `flattenDeep`, `flow`, `flowRight`, `forEach`,
-   * `forEachRight`, `forIn`, `forInRight`, `forOwn`, `forOwnRight`, `functions`,
-   * `groupBy`, `indexBy`, `initial`, `intersection`, `invert`, `invoke`, `keys`,
-   * `keysIn`, `map`, `mapKeys`, `mapValues`, `matches`, `matchesProperty`,
-   * `memoize`, `merge`, `method`, `methodOf`, `mixin`, `negate`, `omit`, `once`,
-   * `pairs`, `partial`, `partialRight`, `partition`, `pick`, `plant`, `pluck`,
-   * `property`, `propertyOf`, `pull`, `pullAt`, `push`, `range`, `rearg`,
-   * `reject`, `remove`, `rest`, `restParam`, `reverse`, `set`, `shuffle`,
-   * `slice`, `sort`, `sortBy`, `sortByAll`, `sortByOrder`, `splice`, `spread`,
-   * `take`, `takeRight`, `takeRightWhile`, `takeWhile`, `tap`, `throttle`,
-   * `thru`, `times`, `toArray`, `toPlainObject`, `transform`, `union`, `uniq`,
-   * `unshift`, `unzip`, `unzipWith`, `values`, `valuesIn`, `where`, `without`,
-   * `wrap`, `xor`, `zip`, `zipObject`, `zipWith`
+   * `countBy`, `create`, `curry`, `debounce`, `defaults`, `defaultsDeep`,
+   * `defer`, `delay`, `difference`, `drop`, `dropRight`, `dropRightWhile`,
+   * `dropWhile`, `fill`, `filter`, `flatten`, `flattenDeep`, `flow`, `flowRight`,
+   * `forEach`, `forEachRight`, `forIn`, `forInRight`, `forOwn`, `forOwnRight`,
+   * `functions`, `groupBy`, `indexBy`, `initial`, `intersection`, `invert`,
+   * `invoke`, `keys`, `keysIn`, `map`, `mapKeys`, `mapValues`, `matches`,
+   * `matchesProperty`, `memoize`, `merge`, `method`, `methodOf`, `mixin`,
+   * `modArgs`, `negate`, `omit`, `once`, `pairs`, `partial`, `partialRight`,
+   * `partition`, `pick`, `plant`, `pluck`, `property`, `propertyOf`, `pull`,
+   * `pullAt`, `push`, `range`, `rearg`, `reject`, `remove`, `rest`, `restParam`,
+   * `reverse`, `set`, `shuffle`, `slice`, `sort`, `sortBy`, `sortByAll`,
+   * `sortByOrder`, `splice`, `spread`, `take`, `takeRight`, `takeRightWhile`,
+   * `takeWhile`, `tap`, `throttle`, `thru`, `times`, `toArray`, `toPlainObject`,
+   * `transform`, `union`, `uniq`, `unshift`, `unzip`, `unzipWith`, `values`,
+   * `valuesIn`, `where`, `without`, `wrap`, `xor`, `zip`, `zipObject`, `zipWith`
    *
    * The wrapper methods that are **not** chainable by default are:
-   * `add`, `attempt`, `camelCase`, `capitalize`, `clone`, `cloneDeep`, `deburr`,
-   * `endsWith`, `escape`, `escapeRegExp`, `every`, `find`, `findIndex`, `findKey`,
-   * `findLast`, `findLastIndex`, `findLastKey`, `findWhere`, `first`, `get`,
-   * `gt`, `gte`, `has`, `identity`, `includes`, `indexOf`, `inRange`, `isArguments`,
-   * `isArray`, `isBoolean`, `isDate`, `isElement`, `isEmpty`, `isEqual`, `isError`,
-   * `isFinite` `isFunction`, `isMatch`, `isNative`, `isNaN`, `isNull`, `isNumber`,
-   * `isObject`, `isPlainObject`, `isRegExp`, `isString`, `isUndefined`,
-   * `isTypedArray`, `join`, `kebabCase`, `last`, `lastIndexOf`, `lt`, `lte`,
-   * `max`, `min`, `noConflict`, `noop`, `now`, `pad`, `padLeft`, `padRight`,
-   * `parseInt`, `pop`, `random`, `reduce`, `reduceRight`, `repeat`, `result`,
-   * `runInContext`, `shift`, `size`, `snakeCase`, `some`, `sortedIndex`,
-   * `sortedLastIndex`, `startCase`, `startsWith`, `sum`, `template`, `trim`,
-   * `trimLeft`, `trimRight`, `trunc`, `unescape`, `uniqueId`, `value`, and `words`
+   * `add`, `attempt`, `camelCase`, `capitalize`, `ceil`, `clone`, `cloneDeep`,
+   * `deburr`, `endsWith`, `escape`, `escapeRegExp`, `every`, `find`, `findIndex`,
+   * `findKey`, `findLast`, `findLastIndex`, `findLastKey`, `findWhere`, `first`,
+   * `floor`, `get`, `gt`, `gte`, `has`, `identity`, `includes`, `indexOf`,
+   * `inRange`, `isArguments`, `isArray`, `isBoolean`, `isDate`, `isElement`,
+   * `isEmpty`, `isEqual`, `isError`, `isFinite` `isFunction`, `isMatch`,
+   * `isNative`, `isNaN`, `isNull`, `isNumber`, `isObject`, `isPlainObject`,
+   * `isRegExp`, `isString`, `isUndefined`, `isTypedArray`, `join`, `kebabCase`,
+   * `last`, `lastIndexOf`, `lt`, `lte`, `max`, `min`, `noConflict`, `noop`,
+   * `now`, `pad`, `padLeft`, `padRight`, `parseInt`, `pop`, `random`, `reduce`,
+   * `reduceRight`, `repeat`, `result`, `round`, `runInContext`, `shift`, `size`,
+   * `snakeCase`, `some`, `sortedIndex`, `sortedLastIndex`, `startCase`,
+   * `startsWith`, `sum`, `template`, `trim`, `trimLeft`, `trimRight`, `trunc`,
+   * `unescape`, `uniqueId`, `value`, and `words`
    *
    * The wrapper method `sample` will return a wrapped value when `n` is provided,
    * otherwise an unwrapped value is returned.

chain/wrapperCommit.js

@@ -10,16 +10,16 @@ define(['../internal/LodashWrapper'], function(LodashWrapper) {
    * @example
    *
    * var array = [1, 2];
-   * var wrapper = _(array).push(3);
+   * var wrapped = _(array).push(3);
    *
    * console.log(array);
    * // => [1, 2]
    *
-   * wrapper = wrapper.commit();
+   * wrapped = wrapped.commit();
    * console.log(array);
    * // => [1, 2, 3]
    *
-   * wrapper.last();
+   * wrapped.last();
    * // => 3
    *
    * console.log(array);

chain/wrapperConcat.js

@@ -0,0 +1,31 @@
+define(['../internal/arrayConcat', '../internal/baseFlatten', '../lang/isArray', '../function/restParam', '../internal/toObject'], function(arrayConcat, baseFlatten, isArray, restParam, toObject) {
+
+  /**
+   * Creates a new array joining a wrapped array with any additional arrays
+   * and/or values.
+   *
+   * @name concat
+   * @memberOf _
+   * @category Chain
+   * @param {...*} [values] The values to concatenate.
+   * @returns {Array} Returns the new concatenated array.
+   * @example
+   *
+   * var array = [1];
+   * var wrapped = _(array).concat(2, [3], [[4]]);
+   *
+   * console.log(wrapped.value());
+   * // => [1, 2, 3, [4]]
+   *
+   * console.log(array);
+   * // => [1]
+   */
+  var wrapperConcat = restParam(function(values) {
+    values = baseFlatten(values);
+    return this.thru(function(array) {
+      return arrayConcat(isArray(array) ? array : [toObject(array)], values);
+    });
+  });
+
+  return wrapperConcat;
+});

chain/wrapperPlant.js

@@ -10,17 +10,17 @@ define(['../internal/baseLodash', '../internal/wrapperClone'], function(baseLoda
    * @example
    *
    * var array = [1, 2];
-   * var wrapper = _(array).map(function(value) {
+   * var wrapped = _(array).map(function(value) {
    *   return Math.pow(value, 2);
    * });
    *
    * var other = [3, 4];
-   * var otherWrapper = wrapper.plant(other);
+   * var otherWrapped = wrapped.plant(other);
    *
-   * otherWrapper.value();
+   * otherWrapped.value();
    * // => [9, 16]
    *
-   * wrapper.value();
+   * wrapped.value();
    * // => [1, 4]
    */
   function wrapperPlant(value) {

chain/wrapperReverse.js

@@ -1,5 +1,8 @@
 define(['../internal/LazyWrapper', '../internal/LodashWrapper', './thru'], function(LazyWrapper, LodashWrapper, thru) {
 
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
   /**
    * Reverses the wrapped array so the first element becomes the last, the
    * second element becomes the second to last, and so on.
@@ -22,15 +25,20 @@ define(['../internal/LazyWrapper', '../internal/LodashWrapper', './thru'], funct
    */
   function wrapperReverse() {
     var value = this.__wrapped__;
+
+    var interceptor = function(value) {
+      return (wrapped && wrapped.__dir__ < 0) ? value : value.reverse();
+    };
     if (value instanceof LazyWrapper) {
+      var wrapped = value;
       if (this.__actions__.length) {
-        value = new LazyWrapper(this);
+        wrapped = new LazyWrapper(this);
       }
-      return new LodashWrapper(value.reverse(), this.__chain__);
+      wrapped = wrapped.reverse();
+      wrapped.__actions__.push({ 'func': thru, 'args': [interceptor], 'thisArg': undefined });
+      return new LodashWrapper(wrapped, this.__chain__);
     }
-    return this.thru(function(value) {
-      return value.reverse();
-    });
+    return this.thru(interceptor);
   }
 
   return wrapperReverse;

collection/every.js

@@ -54,7 +54,7 @@ define(['../internal/arrayEvery', '../internal/baseCallback', '../internal/baseE
   function every(collection, predicate, thisArg) {
     var func = isArray(collection) ? arrayEvery : baseEvery;
     if (thisArg && isIterateeCall(collection, predicate, thisArg)) {
-      predicate = null;
+      predicate = undefined;
     }
     if (typeof predicate != 'function' || thisArg !== undefined) {
       predicate = baseCallback(predicate, thisArg, 3);

collection/includes.js

@@ -5,7 +5,7 @@ define(['../internal/baseIndexOf', '../internal/getLength', '../lang/isArray', '
 
   /**
    * Checks if `value` is in `collection` using
-   * [`SameValueZero`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-samevaluezero)
+   * [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
    * for equality comparisons. If `fromIndex` is negative, it is used as the offset
    * from the end of `collection`.
    *
@@ -38,17 +38,14 @@ define(['../internal/baseIndexOf', '../internal/getLength', '../lang/isArray', '
       collection = values(collection);
       length = collection.length;
     }
-    if (!length) {
-      return false;
-    }
     if (typeof fromIndex != 'number' || (guard && isIterateeCall(target, fromIndex, guard))) {
       fromIndex = 0;
     } else {
       fromIndex = fromIndex < 0 ? nativeMax(length + fromIndex, 0) : (fromIndex || 0);
     }
     return (typeof collection == 'string' || !isArray(collection) && isString(collection))
-      ? (fromIndex < length && collection.indexOf(target, fromIndex) > -1)
-      : (baseIndexOf(collection, target, fromIndex) > -1);
+      ? (fromIndex <= length && collection.indexOf(target, fromIndex) > -1)
+      : (!!length && baseIndexOf(collection, target, fromIndex) > -1);
   }
 
   return includes;

collection/invoke.js

@@ -1,5 +1,8 @@
 define(['../internal/baseEach', '../internal/invokePath', '../internal/isArrayLike', '../internal/isKey', '../function/restParam'], function(baseEach, invokePath, isArrayLike, isKey, restParam) {
 
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
   /**
    * Invokes the method at `path` of each element in `collection`, returning
    * an array of the results of each invoked method. Any additional arguments
@@ -29,7 +32,7 @@ define(['../internal/baseEach', '../internal/invokePath', '../internal/isArrayLi
         result = isArrayLike(collection) ? Array(collection.length) : [];
 
     baseEach(collection, function(value) {
-      var func = isFunc ? path : ((isProp && value != null) ? value[path] : null);
+      var func = isFunc ? path : ((isProp && value != null) ? value[path] : undefined);
       result[++index] = func ? func.apply(value, args) : invokePath(value, path, args);
     });
     return result;

collection/reduce.js

@@ -12,7 +12,8 @@ define(['../internal/arrayReduce', '../internal/baseEach', '../internal/createRe
    * `_.reduce`, `_.reduceRight`, and `_.transform`.
    *
    * The guarded methods are:
-   * `assign`, `defaults`, `includes`, `merge`, `sortByAll`, and `sortByOrder`
+   * `assign`, `defaults`, `defaultsDeep`, `includes`, `merge`, `sortByAll`,
+   * and `sortByOrder`
    *
    * @static
    * @memberOf _

collection/some.js

@@ -55,7 +55,7 @@ define(['../internal/arraySome', '../internal/baseCallback', '../internal/baseSo
   function some(collection, predicate, thisArg) {
     var func = isArray(collection) ? arraySome : baseSome;
     if (thisArg && isIterateeCall(collection, predicate, thisArg)) {
-      predicate = null;
+      predicate = undefined;
     }
     if (typeof predicate != 'function' || thisArg !== undefined) {
       predicate = baseCallback(predicate, thisArg, 3);

collection/sortBy.js

@@ -1,5 +1,8 @@
 define(['../internal/baseCallback', '../internal/baseMap', '../internal/baseSortBy', '../internal/compareAscending', '../internal/isIterateeCall'], function(baseCallback, baseMap, baseSortBy, compareAscending, isIterateeCall) {
 
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
   /**
    * Creates an array of elements, sorted in ascending order by the results of
    * running each element in a collection through `iteratee`. This method performs
@@ -53,7 +56,7 @@ define(['../internal/baseCallback', '../internal/baseMap', '../internal/baseSort
       return [];
     }
     if (thisArg && isIterateeCall(collection, iteratee, thisArg)) {
-      iteratee = null;
+      iteratee = undefined;
     }
     var index = -1;
     iteratee = baseCallback(iteratee, thisArg, 3);

collection/sortByOrder.js

@@ -1,10 +1,13 @@
 define(['../internal/baseSortByOrder', '../lang/isArray', '../internal/isIterateeCall'], function(baseSortByOrder, isArray, isIterateeCall) {
 
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
   /**
    * This method is like `_.sortByAll` except that it allows specifying the
-   * sort orders of the iteratees to sort by. A truthy value in `orders` will
-   * sort the corresponding property name in ascending order while a falsey
-   * value will sort it in descending order.
+   * sort orders of the iteratees to sort by. If `orders` is unspecified, all
+   * values are sorted in ascending order. Otherwise, a value is sorted in
+   * ascending order if its corresponding order is "asc", and descending if "desc".
    *
    * If a property name is provided for an iteratee the created `_.property`
    * style callback returns the property value of the given element.
@@ -18,7 +21,7 @@ define(['../internal/baseSortByOrder', '../lang/isArray', '../internal/isIterate
    * @category Collection
    * @param {Array|Object|string} collection The collection to iterate over.
    * @param {Function[]|Object[]|string[]} iteratees The iteratees to sort by.
-   * @param {boolean[]} orders The sort orders of `iteratees`.
+   * @param {boolean[]} [orders] The sort orders of `iteratees`.
    * @param- {Object} [guard] Enables use as a callback for functions like `_.reduce`.
    * @returns {Array} Returns the new sorted array.
    * @example
@@ -31,7 +34,7 @@ define(['../internal/baseSortByOrder', '../lang/isArray', '../internal/isIterate
    * ];
    *
    * // sort by `user` in ascending order and by `age` in descending order
-   * _.map(_.sortByOrder(users, ['user', 'age'], [true, false]), _.values);
+   * _.map(_.sortByOrder(users, ['user', 'age'], ['asc', 'desc']), _.values);
    * // => [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 42]]
    */
   function sortByOrder(collection, iteratees, orders, guard) {
@@ -39,7 +42,7 @@ define(['../internal/baseSortByOrder', '../lang/isArray', '../internal/isIterate
       return [];
     }
     if (guard && isIterateeCall(iteratees, orders, guard)) {
-      orders = null;
+      orders = undefined;
     }
     if (!isArray(iteratees)) {
       iteratees = iteratees == null ? [] : [iteratees];

function.js

@@ -1,4 +1,4 @@
-define(['./function/after', './function/ary', './function/backflow', './function/before', './function/bind', './function/bindAll', './function/bindKey', './function/compose', './function/curry', './function/curryRight', './function/debounce', './function/defer', './function/delay', './function/flow', './function/flowRight', './function/memoize', './function/negate', './function/once', './function/partial', './function/partialRight', './function/rearg', './function/restParam', './function/spread', './function/throttle', './function/wrap'], function(after, ary, backflow, before, bind, bindAll, bindKey, compose, curry, curryRight, debounce, defer, delay, flow, flowRight, memoize, negate, once, partial, partialRight, rearg, restParam, spread, throttle, wrap) {
+define(['./function/after', './function/ary', './function/backflow', './function/before', './function/bind', './function/bindAll', './function/bindKey', './function/compose', './function/curry', './function/curryRight', './function/debounce', './function/defer', './function/delay', './function/flow', './function/flowRight', './function/memoize', './function/modArgs', './function/negate', './function/once', './function/partial', './function/partialRight', './function/rearg', './function/restParam', './function/spread', './function/throttle', './function/wrap'], function(after, ary, backflow, before, bind, bindAll, bindKey, compose, curry, curryRight, debounce, defer, delay, flow, flowRight, memoize, modArgs, negate, once, partial, partialRight, rearg, restParam, spread, throttle, wrap) {
   return {
     'after': after,
     'ary': ary,
@@ -16,6 +16,7 @@ define(['./function/after', './function/ary', './function/backflow', './function
     'flow': flow,
     'flowRight': flowRight,
     'memoize': memoize,
+    'modArgs': modArgs,
     'negate': negate,
     'once': once,
     'partial': partial,

function/ary.js

@@ -1,5 +1,8 @@
 define(['../internal/createWrapper', '../internal/isIterateeCall'], function(createWrapper, isIterateeCall) {
 
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
   /** Used to compose bitmasks for wrapper metadata. */
   var ARY_FLAG = 128;
 
@@ -24,10 +27,10 @@ define(['../internal/createWrapper', '../internal/isIterateeCall'], function(cre
    */
   function ary(func, n, guard) {
     if (guard && isIterateeCall(func, n, guard)) {
-      n = null;
+      n = undefined;
     }
     n = (func && n == null) ? func.length : nativeMax(+n || 0, 0);
-    return createWrapper(func, ARY_FLAG, null, null, null, null, n);
+    return createWrapper(func, ARY_FLAG, undefined, undefined, undefined, undefined, n);
   }
 
   return ary;

function/before.js

@@ -1,5 +1,8 @@
 define([], function() {
 
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
   /** Used as the `TypeError` message for "Functions" methods. */
   var FUNC_ERROR_TEXT = 'Expected a function';
 
@@ -35,7 +38,7 @@ define([], function() {
         result = func.apply(this, arguments);
       }
       if (n <= 1) {
-        func = null;
+        func = undefined;
       }
       return result;
     };

function/debounce.js

@@ -92,9 +92,9 @@ define(['../lang/isObject', '../date/now'], function(isObject, now) {
       var leading = true;
       trailing = false;
     } else if (isObject(options)) {
-      leading = options.leading;
+      leading = !!options.leading;
       maxWait = 'maxWait' in options && nativeMax(+options.maxWait || 0, wait);
-      trailing = 'trailing' in options ? options.trailing : trailing;
+      trailing = 'trailing' in options ? !!options.trailing : trailing;
     }
 
     function cancel() {
@@ -104,41 +104,35 @@ define(['../lang/isObject', '../date/now'], function(isObject, now) {
       if (maxTimeoutId) {
         clearTimeout(maxTimeoutId);
       }
+      lastCalled = 0;
       maxTimeoutId = timeoutId = trailingCall = undefined;
     }
 
+    function complete(isCalled, id) {
+      if (id) {
+        clearTimeout(id);
+      }
+      maxTimeoutId = timeoutId = trailingCall = undefined;
+      if (isCalled) {
+        lastCalled = now();
+        result = func.apply(thisArg, args);
+        if (!timeoutId && !maxTimeoutId) {
+          args = thisArg = undefined;
+        }
+      }
+    }
+
     function delayed() {
       var remaining = wait - (now() - stamp);
       if (remaining <= 0 || remaining > wait) {
-        if (maxTimeoutId) {
-          clearTimeout(maxTimeoutId);
-        }
-        var isCalled = trailingCall;
-        maxTimeoutId = timeoutId = trailingCall = undefined;
-        if (isCalled) {
-          lastCalled = now();
-          result = func.apply(thisArg, args);
-          if (!timeoutId && !maxTimeoutId) {
-            args = thisArg = null;
-          }
-        }
+        complete(trailingCall, maxTimeoutId);
       } else {
         timeoutId = setTimeout(delayed, remaining);
       }
     }
 
     function maxDelayed() {
-      if (timeoutId) {
-        clearTimeout(timeoutId);
-      }
-      maxTimeoutId = timeoutId = trailingCall = undefined;
-      if (trailing || (maxWait !== wait)) {
-        lastCalled = now();
-        result = func.apply(thisArg, args);
-        if (!timeoutId && !maxTimeoutId) {
-          args = thisArg = null;
-        }
-      }
+      complete(trailing, timeoutId);
     }
 
     function debounced() {
@@ -178,7 +172,7 @@ define(['../lang/isObject', '../date/now'], function(isObject, now) {
         result = func.apply(thisArg, args);
       }
       if (isCalled && !timeoutId && !maxTimeoutId) {
-        args = thisArg = null;
+        args = thisArg = undefined;
       }
       return result;
     }

function/memoize.js

@@ -13,7 +13,7 @@ define(['../internal/MapCache'], function(MapCache) {
    *
    * **Note:** The cache is exposed as the `cache` property on the memoized
    * function. Its creation may be customized by replacing the `_.memoize.Cache`
-   * constructor with one whose instances implement the [`Map`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-properties-of-the-map-prototype-object)
+   * constructor with one whose instances implement the [`Map`](http://ecma-international.org/ecma-262/6.0/#sec-properties-of-the-map-prototype-object)
    * method interface of `get`, `has`, and `set`.
    *
    * @static

function/modArgs.js

@@ -0,0 +1,56 @@
+define(['../internal/arrayEvery', '../internal/baseFlatten', '../internal/baseIsFunction', './restParam'], function(arrayEvery, baseFlatten, baseIsFunction, restParam) {
+
+  /** Used as the `TypeError` message for "Functions" methods. */
+  var FUNC_ERROR_TEXT = 'Expected a function';
+
+  /* Native method references for those with the same name as other `lodash` methods. */
+  var nativeMin = Math.min;
+
+  /**
+   * Creates a function that runs each argument through a corresponding
+   * transform function.
+   *
+   * @static
+   * @memberOf _
+   * @category Function
+   * @param {Function} func The function to wrap.
+   * @param {...(Function|Function[])} [transforms] The functions to transform
+   * arguments, specified as individual functions or arrays of functions.
+   * @returns {Function} Returns the new function.
+   * @example
+   *
+   * function doubled(n) {
+   *   return n * 2;
+   * }
+   *
+   * function square(n) {
+   *   return n * n;
+   * }
+   *
+   * var modded = _.modArgs(function(x, y) {
+   *   return [x, y];
+   * }, square, doubled);
+   *
+   * modded(1, 2);
+   * // => [1, 4]
+   *
+   * modded(5, 10);
+   * // => [25, 20]
+   */
+  var modArgs = restParam(function(func, transforms) {
+    transforms = baseFlatten(transforms);
+    if (typeof func != 'function' || !arrayEvery(transforms, baseIsFunction)) {
+      throw new TypeError(FUNC_ERROR_TEXT);
+    }
+    var length = transforms.length;
+    return restParam(function(args) {
+      var index = nativeMin(args.length, length);
+      while (index--) {
+        args[index] = transforms[index](args[index]);
+      }
+      return func.apply(this, args);
+    });
+  });
+
+  return modArgs;
+});

function/rearg.js

@@ -1,5 +1,8 @@
 define(['../internal/baseFlatten', '../internal/createWrapper', './restParam'], function(baseFlatten, createWrapper, restParam) {
 
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
   /** Used to compose bitmasks for wrapper metadata. */
   var REARG_FLAG = 256;
 
@@ -32,7 +35,7 @@ define(['../internal/baseFlatten', '../internal/createWrapper', './restParam'],
    * // => [3, 6, 9]
    */
   var rearg = restParam(function(func, indexes) {
-    return createWrapper(func, REARG_FLAG, null, null, null, baseFlatten(indexes));
+    return createWrapper(func, REARG_FLAG, undefined, undefined, undefined, baseFlatten(indexes));
   });
 
   return rearg;

function/throttle.js

@@ -3,13 +3,6 @@ define(['./debounce', '../lang/isObject'], function(debounce, isObject) {
   /** Used as the `TypeError` message for "Functions" methods. */
   var FUNC_ERROR_TEXT = 'Expected a function';
 
-  /** Used as an internal `_.debounce` options object by `_.throttle`. */
-  var debounceOptions = {
-    'leading': false,
-    'maxWait': 0,
-    'trailing': false
-  };
-
   /**
    * Creates a throttled function that only invokes `func` at most once per
    * every `wait` milliseconds. The throttled function comes with a `cancel`
@@ -62,10 +55,7 @@ define(['./debounce', '../lang/isObject'], function(debounce, isObject) {
       leading = 'leading' in options ? !!options.leading : leading;
       trailing = 'trailing' in options ? !!options.trailing : trailing;
     }
-    debounceOptions.leading = leading;
-    debounceOptions.maxWait = +wait;
-    debounceOptions.trailing = trailing;
-    return debounce(func, wait, debounceOptions);
+    return debounce(func, wait, { 'leading': leading, 'maxWait': +wait, 'trailing': trailing });
   }
 
   return throttle;

function/wrap.js

@@ -1,5 +1,8 @@
 define(['../internal/createWrapper', '../utility/identity'], function(createWrapper, identity) {
 
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
   /** Used to compose bitmasks for wrapper metadata. */
   var PARTIAL_FLAG = 32;
 
@@ -26,7 +29,7 @@ define(['../internal/createWrapper', '../utility/identity'], function(createWrap
    */
   function wrap(value, wrapper) {
     wrapper = wrapper == null ? identity : wrapper;
-    return createWrapper(wrapper, PARTIAL_FLAG, null, [value], []);
+    return createWrapper(wrapper, PARTIAL_FLAG, undefined, [value], []);
   }
 
   return wrap;

internal/LazyWrapper.js

@@ -11,13 +11,12 @@ define(['./baseCreate', './baseLodash'], function(baseCreate, baseLodash) {
    */
   function LazyWrapper(value) {
     this.__wrapped__ = value;
-    this.__actions__ = null;
+    this.__actions__ = [];
     this.__dir__ = 1;
-    this.__dropCount__ = 0;
     this.__filtered__ = false;
-    this.__iteratees__ = null;
+    this.__iteratees__ = [];
     this.__takeCount__ = POSITIVE_INFINITY;
-    this.__views__ = null;
+    this.__views__ = [];
   }
 
   LazyWrapper.prototype = baseCreate(baseLodash.prototype);

internal/arrayConcat.js

@@ -0,0 +1,28 @@
+define([], function() {
+
+  /**
+   * Creates a new array joining `array` with `other`.
+   *
+   * @private
+   * @param {Array} array The array to join.
+   * @param {Array} other The other array to join.
+   * @returns {Array} Returns the new concatenated array.
+   */
+  function arrayConcat(array, other) {
+    var index = -1,
+        length = array.length,
+        othIndex = -1,
+        othLength = other.length,
+        result = Array(length + othLength);
+
+    while (++index < length) {
+      result[index] = array[index];
+    }
+    while (++othIndex < othLength) {
+      result[index++] = other[othIndex];
+    }
+    return result;
+  }
+
+  return arrayConcat;
+});

internal/arrayPush.js

@@ -0,0 +1,23 @@
+define([], function() {
+
+  /**
+   * Appends the elements of `values` to `array`.
+   *
+   * @private
+   * @param {Array} array The array to modify.
+   * @param {Array} values The values to append.
+   * @returns {Array} Returns `array`.
+   */
+  function arrayPush(array, values) {
+    var index = -1,
+        length = values.length,
+        offset = array.length;
+
+    while (++index < length) {
+      array[offset + index] = values[index];
+    }
+    return array;
+  }
+
+  return arrayPush;
+});

internal/arraySum.js

@@ -1,18 +1,20 @@
 define([], function() {
 
   /**
-   * A specialized version of `_.sum` for arrays without support for iteratees.
+   * A specialized version of `_.sum` for arrays without support for callback
+   * shorthands and `this` binding..
    *
    * @private
    * @param {Array} array The array to iterate over.
+   * @param {Function} iteratee The function invoked per iteration.
    * @returns {number} Returns the sum.
    */
-  function arraySum(array) {
+  function arraySum(array, iteratee) {
     var length = array.length,
         result = 0;
 
     while (length--) {
-      result += +array[length] || 0;
+      result += +iteratee(array[length]) || 0;
     }
     return result;
   }

internal/baseClone.js

@@ -48,7 +48,7 @@ define(['./arrayCopy', './arrayEach', './baseAssign', './baseForOwn', './initClo
   var objectProto = Object.prototype;
 
   /**
-   * Used to resolve the [`toStringTag`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.prototype.tostring)
+   * Used to resolve the [`toStringTag`](http://ecma-international.org/ecma-262/6.0/#sec-object.prototype.tostring)
    * of values.
    */
   var objToString = objectProto.toString;
@@ -99,7 +99,7 @@ define(['./arrayCopy', './arrayEach', './baseAssign', './baseForOwn', './initClo
           : (object ? value : {});
       }
     }
-    // Check for circular references and return corresponding clone.
+    // Check for circular references and return its corresponding clone.
     stackA || (stackA = []);
     stackB || (stackB = []);
 

internal/baseCreate.js

@@ -1,5 +1,8 @@
 define(['../lang/isObject'], function(isObject) {
 
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
   /**
    * The base implementation of `_.create` without support for assigning
    * properties to the created object.
@@ -14,7 +17,7 @@ define(['../lang/isObject'], function(isObject) {
       if (isObject(prototype)) {
         object.prototype = prototype;
         var result = new object;
-        object.prototype = null;
+        object.prototype = undefined;
       }
       return result || {};
     };

internal/baseDifference.js

@@ -1,5 +1,8 @@
 define(['./baseIndexOf', './cacheIndexOf', './createCache'], function(baseIndexOf, cacheIndexOf, createCache) {
 
+  /** Used as the size to enable large array optimizations. */
+  var LARGE_ARRAY_SIZE = 200;
+
   /**
    * The base implementation of `_.difference` which accepts a single array
    * of values to exclude.
@@ -19,7 +22,7 @@ define(['./baseIndexOf', './cacheIndexOf', './createCache'], function(baseIndexO
     var index = -1,
         indexOf = baseIndexOf,
         isCommon = true,
-        cache = (isCommon && values.length >= 200) ? createCache(values) : null,
+        cache = (isCommon && values.length >= LARGE_ARRAY_SIZE) ? createCache(values) : null,
         valuesLength = values.length;
 
     if (cache) {

internal/baseFlatten.js

@@ -1,4 +1,4 @@
-define(['../lang/isArguments', '../lang/isArray', './isArrayLike', './isObjectLike'], function(isArguments, isArray, isArrayLike, isObjectLike) {
+define(['./arrayPush', '../lang/isArguments', '../lang/isArray', './isArrayLike', './isObjectLike'], function(arrayPush, isArguments, isArray, isArrayLike, isObjectLike) {
 
   /**
    * The base implementation of `_.flatten` with added support for restricting
@@ -8,13 +8,14 @@ define(['../lang/isArguments', '../lang/isArray', './isArrayLike', './isObjectLi
    * @param {Array} array The array to flatten.
    * @param {boolean} [isDeep] Specify a deep flatten.
    * @param {boolean} [isStrict] Restrict flattening to arrays-like objects.
+   * @param {Array} [result=[]] The initial result value.
    * @returns {Array} Returns the new flattened array.
    */
-  function baseFlatten(array, isDeep, isStrict) {
+  function baseFlatten(array, isDeep, isStrict, result) {
+    result || (result = []);
+
     var index = -1,
-        length = array.length,
-        resIndex = -1,
-        result = [];
+        length = array.length;
 
     while (++index < length) {
       var value = array[index];
@@ -22,16 +23,12 @@ define(['../lang/isArguments', '../lang/isArray', './isArrayLike', './isObjectLi
           (isStrict || isArray(value) || isArguments(value))) {
         if (isDeep) {
           // Recursively flatten arrays (susceptible to call stack limits).
-          value = baseFlatten(value, isDeep, isStrict);
-        }
-        var valIndex = -1,
-            valLength = value.length;
-
-        while (++valIndex < valLength) {
-          result[++resIndex] = value[valIndex];
+          baseFlatten(value, isDeep, isStrict, result);
+        } else {
+          arrayPush(result, value);
         }
       } else if (!isStrict) {
-        result[++resIndex] = value;
+        result[result.length] = value;
       }
     }
     return result;

internal/baseIsEqualDeep.js

@@ -12,7 +12,7 @@ define(['./equalArrays', './equalByTag', './equalObjects', '../lang/isArray', '.
   var hasOwnProperty = objectProto.hasOwnProperty;
 
   /**
-   * Used to resolve the [`toStringTag`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.prototype.tostring)
+   * Used to resolve the [`toStringTag`](http://ecma-international.org/ecma-262/6.0/#sec-object.prototype.tostring)
    * of values.
    */
   var objToString = objectProto.toString;

internal/baseMerge.js

@@ -10,7 +10,7 @@ define(['./arrayEach', './baseMergeDeep', '../lang/isArray', './isArrayLike', '.
    * @private
    * @param {Object} object The destination object.
    * @param {Object} source The source object.
-   * @param {Function} [customizer] The function to customize merging properties.
+   * @param {Function} [customizer] The function to customize merged values.
    * @param {Array} [stackA=[]] Tracks traversed source objects.
    * @param {Array} [stackB=[]] Associates values with source counterparts.
    * @returns {Object} Returns `object`.
@@ -20,7 +20,7 @@ define(['./arrayEach', './baseMergeDeep', '../lang/isArray', './isArrayLike', '.
       return object;
     }
     var isSrcArr = isArrayLike(source) && (isArray(source) || isTypedArray(source)),
-        props = isSrcArr ? null : keys(source);
+        props = isSrcArr ? undefined : keys(source);
 
     arrayEach(props || source, function(srcValue, key) {
       if (props) {

internal/baseMergeDeep.js

@@ -13,7 +13,7 @@ define(['./arrayCopy', '../lang/isArguments', '../lang/isArray', './isArrayLike'
    * @param {Object} source The source object.
    * @param {string} key The key of the value to merge.
    * @param {Function} mergeFunc The function to merge values.
-   * @param {Function} [customizer] The function to customize merging properties.
+   * @param {Function} [customizer] The function to customize merged values.
    * @param {Array} [stackA=[]] Tracks traversed source objects.
    * @param {Array} [stackB=[]] Associates values with source counterparts.
    * @returns {boolean} Returns `true` if the objects are equivalent, else `false`.

internal/baseRandom.js

@@ -1,10 +1,8 @@
 define([], function() {
 
-  /** Native method references. */
-  var floor = Math.floor;
-
   /* Native method references for those with the same name as other `lodash` methods. */
-  var nativeRandom = Math.random;
+  var nativeFloor = Math.floor,
+      nativeRandom = Math.random;
 
   /**
    * The base implementation of `_.random` without support for argument juggling
@@ -16,7 +14,7 @@ define([], function() {
    * @returns {number} Returns the random number.
    */
   function baseRandom(min, max) {
-    return min + floor(nativeRandom() * (max - min + 1));
+    return min + nativeFloor(nativeRandom() * (max - min + 1));
   }
 
   return baseRandom;

internal/baseToString.js

@@ -9,9 +9,6 @@ define([], function() {
    * @returns {string} Returns the string.
    */
   function baseToString(value) {
-    if (typeof value == 'string') {
-      return value;
-    }
     return value == null ? '' : (value + '');
   }
 

internal/baseUniq.js

@@ -1,5 +1,8 @@
 define(['./baseIndexOf', './cacheIndexOf', './createCache'], function(baseIndexOf, cacheIndexOf, createCache) {
 
+  /** Used as the size to enable large array optimizations. */
+  var LARGE_ARRAY_SIZE = 200;
+
   /**
    * The base implementation of `_.uniq` without support for callback shorthands
    * and `this` binding.
@@ -14,7 +17,7 @@ define(['./baseIndexOf', './cacheIndexOf', './createCache'], function(baseIndexO
         indexOf = baseIndexOf,
         length = array.length,
         isCommon = true,
-        isLarge = isCommon && length >= 200,
+        isLarge = isCommon && length >= LARGE_ARRAY_SIZE,
         seen = isLarge ? createCache() : null,
         result = [];
 

internal/baseWrapperValue.js

@@ -1,10 +1,4 @@
-define(['./LazyWrapper'], function(LazyWrapper) {
-
-  /** Used for native method references. */
-  var arrayProto = Array.prototype;
-
-  /** Native method references. */
-  var push = arrayProto.push;
+define(['./LazyWrapper', './arrayPush'], function(LazyWrapper, arrayPush) {
 
   /**
    * The base implementation of `wrapperValue` which returns the result of
@@ -25,11 +19,8 @@ define(['./LazyWrapper'], function(LazyWrapper) {
         length = actions.length;
 
     while (++index < length) {
-      var args = [result],
-          action = actions[index];
-
-      push.apply(args, action.args);
-      result = action.func.apply(action.thisArg, args);
+      var action = actions[index];
+      result = action.func.apply(action.thisArg, arrayPush([result], action.args));
     }
     return result;
   }

internal/binaryIndexBy.js

@@ -3,11 +3,9 @@ define([], function() {
   /** Used as a safe reference for `undefined` in pre-ES5 environments. */
   var undefined;
 
-  /** Native method references. */
-  var floor = Math.floor;
-
   /* Native method references for those with the same name as other `lodash` methods. */
-  var nativeMin = Math.min;
+  var nativeFloor = Math.floor,
+      nativeMin = Math.min;
 
   /** Used as references for the maximum length and index of an array. */
   var MAX_ARRAY_LENGTH = 4294967295,
@@ -36,7 +34,7 @@ define([], function() {
         valIsUndef = value === undefined;
 
     while (low < high) {
-      var mid = floor((low + high) / 2),
+      var mid = nativeFloor((low + high) / 2),
           computed = iteratee(array[mid]),
           isDef = computed !== undefined,
           isReflexive = computed === computed;

internal/bufferClone.js

@@ -1,25 +1,8 @@
-define(['../utility/constant', './getNative', './root'], function(constant, getNative, root) {
+define(['./root'], function(root) {
 
   /** Native method references. */
-  var ArrayBuffer = getNative(root, 'ArrayBuffer'),
-      bufferSlice = getNative(ArrayBuffer && new ArrayBuffer(0), 'slice'),
-      floor = Math.floor,
-      Uint8Array = getNative(root, 'Uint8Array');
-
-  /** Used to clone array buffers. */
-  var Float64Array = (function() {
-    // Safari 5 errors when using an array buffer to initialize a typed array
-    // where the array buffer's `byteLength` is not a multiple of the typed
-    // array's `BYTES_PER_ELEMENT`.
-    try {
-      var func = getNative(root, 'Float64Array'),
-          result = new func(new ArrayBuffer(10), 0, 1) && func;
-    } catch(e) {}
-    return result || null;
-  }());
-
-  /** Used as the size, in bytes, of each `Float64Array` element. */
-  var FLOAT64_BYTES_PER_ELEMENT = Float64Array ? Float64Array.BYTES_PER_ELEMENT : 0;
+  var ArrayBuffer = root.ArrayBuffer,
+      Uint8Array = root.Uint8Array;
 
   /**
    * Creates a clone of the given array buffer.
@@ -29,26 +12,11 @@ define(['../utility/constant', './getNative', './root'], function(constant, getN
    * @returns {ArrayBuffer} Returns the cloned array buffer.
    */
   function bufferClone(buffer) {
-    return bufferSlice.call(buffer, 0);
-  }
-  if (!bufferSlice) {
-    // PhantomJS has `ArrayBuffer` and `Uint8Array` but not `Float64Array`.
-    bufferClone = !(ArrayBuffer && Uint8Array) ? constant(null) : function(buffer) {
-      var byteLength = buffer.byteLength,
-          floatLength = Float64Array ? floor(byteLength / FLOAT64_BYTES_PER_ELEMENT) : 0,
-          offset = floatLength * FLOAT64_BYTES_PER_ELEMENT,
-          result = new ArrayBuffer(byteLength);
+    var result = new ArrayBuffer(buffer.byteLength),
+        view = new Uint8Array(result);
 
-      if (floatLength) {
-        var view = new Float64Array(result, 0, floatLength);
-        view.set(new Float64Array(buffer, 0, floatLength));
-      }
-      if (byteLength != offset) {
-        view = new Uint8Array(result, offset);
-        view.set(new Uint8Array(buffer, offset));
-      }
-      return result;
-    };
+    view.set(new Uint8Array(buffer));
+    return result;
   }
 
   return bufferClone;

internal/compareAscending.js

@@ -5,8 +5,8 @@ define(['./baseCompareAscending'], function(baseCompareAscending) {
    * sort them in ascending order.
    *
    * @private
-   * @param {Object} object The object to compare to `other`.
-   * @param {Object} other The object to compare to `object`.
+   * @param {Object} object The object to compare.
+   * @param {Object} other The other object to compare.
    * @returns {number} Returns the sort order indicator for `object`.
    */
   function compareAscending(object, other) {

internal/compareMultiple.js

@@ -1,16 +1,16 @@
 define(['./baseCompareAscending'], function(baseCompareAscending) {
 
   /**
-   * Used by `_.sortByOrder` to compare multiple properties of each element
-   * in a collection and stable sort them in the following order:
+   * Used by `_.sortByOrder` to compare multiple properties of a value to another
+   * and stable sort them.
    *
-   * If `orders` is unspecified, sort in ascending order for all properties.
-   * Otherwise, for each property, sort in ascending order if its corresponding value in
-   * orders is true, and descending order if false.
+   * If `orders` is unspecified, all valuess are sorted in ascending order. Otherwise,
+   * a value is sorted in ascending order if its corresponding order is "asc", and
+   * descending if "desc".
    *
    * @private
-   * @param {Object} object The object to compare to `other`.
-   * @param {Object} other The object to compare to `object`.
+   * @param {Object} object The object to compare.
+   * @param {Object} other The other object to compare.
    * @param {boolean[]} orders The order to sort by for each property.
    * @returns {number} Returns the sort order indicator for `object`.
    */
@@ -27,7 +27,8 @@ define(['./baseCompareAscending'], function(baseCompareAscending) {
         if (index >= ordersLength) {
           return result;
         }
-        return result * (orders[index] ? 1 : -1);
+        var order = orders[index];
+        return result * ((order === 'asc' || order === true) ? 1 : -1);
       }
     }
     // Fixes an `Array#sort` bug in the JS engine embedded in Adobe applications

internal/composeArgs.js

@@ -19,7 +19,7 @@ define([], function() {
         argsLength = nativeMax(args.length - holdersLength, 0),
         leftIndex = -1,
         leftLength = partials.length,
-        result = Array(argsLength + leftLength);
+        result = Array(leftLength + argsLength);
 
     while (++leftIndex < leftLength) {
       result[leftIndex] = partials[leftIndex];

internal/createAggregator.js

@@ -1,12 +1,7 @@
 define(['./baseCallback', './baseEach', '../lang/isArray'], function(baseCallback, baseEach, isArray) {
 
   /**
-   * Creates a function that aggregates a collection, creating an accumulator
-   * object composed from the results of running each element in the collection
-   * through an iteratee.
-   *
-   * **Note:** This function is used to create `_.countBy`, `_.groupBy`, `_.indexBy`,
-   * and `_.partition`.
+   * Creates a `_.countBy`, `_.groupBy`, `_.indexBy`, or `_.partition` function.
    *
    * @private
    * @param {Function} setter The function to set keys and values of the accumulator object.

internal/createAssigner.js

@@ -4,10 +4,7 @@ define(['./bindCallback', './isIterateeCall', '../function/restParam'], function
   var undefined;
 
   /**
-   * Creates a function that assigns properties of source object(s) to a given
-   * destination object.
-   *
-   * **Note:** This function is used to create `_.assign`, `_.defaults`, and `_.merge`.
+   * Creates a `_.assign`, `_.defaults`, or `_.merge` function.
    *
    * @private
    * @param {Function} assigner The function to assign values.

internal/createCache.js

@@ -1,4 +1,4 @@
-define(['./SetCache', '../utility/constant', './getNative', './root'], function(SetCache, constant, getNative, root) {
+define(['./SetCache', './getNative', './root'], function(SetCache, getNative, root) {
 
   /** Native method references. */
   var Set = getNative(root, 'Set');
@@ -13,9 +13,9 @@ define(['./SetCache', '../utility/constant', './getNative', './root'], function(
    * @param {Array} [values] The values to cache.
    * @returns {null|Object} Returns the new cache object if `Set` is supported, else `null`.
    */
-  var createCache = !(nativeCreate && Set) ? constant(null) : function(values) {
-    return new SetCache(values);
-  };
+  function createCache(values) {
+    return (nativeCreate && Set) ? new SetCache(values) : null;
+  }
 
   return createCache;
 });

internal/createCtorWrapper.js

@@ -11,7 +11,7 @@ define(['./baseCreate', '../lang/isObject'], function(baseCreate, isObject) {
   function createCtorWrapper(Ctor) {
     return function() {
       // Use a `switch` statement to work with class constructors.
-      // See https://people.mozilla.org/~jorendorff/es6-draft.html#sec-ecmascript-function-objects-call-thisargument-argumentslist
+      // See http://ecma-international.org/ecma-262/6.0/#sec-ecmascript-function-objects-call-thisargument-argumentslist
       // for more details.
       var args = arguments;
       switch (args.length) {
@@ -21,6 +21,8 @@ define(['./baseCreate', '../lang/isObject'], function(baseCreate, isObject) {
         case 3: return new Ctor(args[0], args[1], args[2]);
         case 4: return new Ctor(args[0], args[1], args[2], args[3]);
         case 5: return new Ctor(args[0], args[1], args[2], args[3], args[4]);
+        case 6: return new Ctor(args[0], args[1], args[2], args[3], args[4], args[5]);
+        case 7: return new Ctor(args[0], args[1], args[2], args[3], args[4], args[5], args[6]);
       }
       var thisBinding = baseCreate(Ctor.prototype),
           result = Ctor.apply(thisBinding, args);

internal/createCurry.js

@@ -1,5 +1,8 @@
 define(['./createWrapper', './isIterateeCall'], function(createWrapper, isIterateeCall) {
 
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
   /**
    * Creates a `_.curry` or `_.curryRight` function.
    *
@@ -10,9 +13,9 @@ define(['./createWrapper', './isIterateeCall'], function(createWrapper, isIterat
   function createCurry(flag) {
     function curryFunc(func, arity, guard) {
       if (guard && isIterateeCall(func, arity, guard)) {
-        arity = null;
+        arity = undefined;
       }
-      var result = createWrapper(func, flag, null, null, null, null, null, arity);
+      var result = createWrapper(func, flag, undefined, undefined, undefined, undefined, undefined, arity);
       result.placeholder = curryFunc.placeholder;
       return result;
     }

internal/createDefaults.js

@@ -0,0 +1,26 @@
+define(['../function/restParam'], function(restParam) {
+
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
+  /**
+   * Creates a `_.defaults` or `_.defaultsDeep` function.
+   *
+   * @private
+   * @param {Function} assigner The function to assign values.
+   * @param {Function} customizer The function to customize assigned values.
+   * @returns {Function} Returns the new defaults function.
+   */
+  function createDefaults(assigner, customizer) {
+    return restParam(function(args) {
+      var object = args[0];
+      if (object == null) {
+        return object;
+      }
+      args.push(customizer);
+      return assigner.apply(undefined, args);
+    });
+  }
+
+  return createDefaults;
+});

internal/createExtremum.js

@@ -1,4 +1,7 @@
-define(['./arrayExtremum', './baseCallback', './baseExtremum', './isIterateeCall', './toIterable'], function(arrayExtremum, baseCallback, baseExtremum, isIterateeCall, toIterable) {
+define(['./arrayExtremum', './baseCallback', './baseExtremum', '../lang/isArray', './isIterateeCall', './toIterable'], function(arrayExtremum, baseCallback, baseExtremum, isArray, isIterateeCall, toIterable) {
+
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
 
   /**
    * Creates a `_.max` or `_.min` function.
@@ -11,11 +14,11 @@ define(['./arrayExtremum', './baseCallback', './baseExtremum', './isIterateeCall
   function createExtremum(comparator, exValue) {
     return function(collection, iteratee, thisArg) {
       if (thisArg && isIterateeCall(collection, iteratee, thisArg)) {
-        iteratee = null;
+        iteratee = undefined;
       }
       iteratee = baseCallback(iteratee, thisArg, 3);
       if (iteratee.length == 1) {
-        collection = toIterable(collection);
+        collection = isArray(collection) ? collection : toIterable(collection);
         var result = arrayExtremum(collection, iteratee, comparator, exValue);
         if (!(collection.length && result === exValue)) {
           return result;

internal/createFlow.js

@@ -1,11 +1,17 @@
 define(['./LodashWrapper', './getData', './getFuncName', '../lang/isArray', './isLaziable'], function(LodashWrapper, getData, getFuncName, isArray, isLaziable) {
 
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
   /** Used to compose bitmasks for wrapper metadata. */
   var CURRY_FLAG = 8,
       PARTIAL_FLAG = 32,
       ARY_FLAG = 128,
       REARG_FLAG = 256;
 
+  /** Used as the size to enable large array optimizations. */
+  var LARGE_ARRAY_SIZE = 200;
+
   /** Used as the `TypeError` message for "Functions" methods. */
   var FUNC_ERROR_TEXT = 'Expected a function';
 
@@ -30,7 +36,7 @@ define(['./LodashWrapper', './getData', './getFuncName', '../lang/isArray', './i
           throw new TypeError(FUNC_ERROR_TEXT);
         }
         if (!wrapper && LodashWrapper.prototype.thru && getFuncName(func) == 'wrapper') {
-          wrapper = new LodashWrapper([]);
+          wrapper = new LodashWrapper([], true);
         }
       }
       index = wrapper ? -1 : length;
@@ -38,7 +44,7 @@ define(['./LodashWrapper', './getData', './getFuncName', '../lang/isArray', './i
         func = funcs[index];
 
         var funcName = getFuncName(func),
-            data = funcName == 'wrapper' ? getData(func) : null;
+            data = funcName == 'wrapper' ? getData(func) : undefined;
 
         if (data && isLaziable(data[0]) && data[1] == (ARY_FLAG | CURRY_FLAG | PARTIAL_FLAG | REARG_FLAG) && !data[4].length && data[9] == 1) {
           wrapper = wrapper[getFuncName(data[0])].apply(wrapper, data[3]);
@@ -47,12 +53,14 @@ define(['./LodashWrapper', './getData', './getFuncName', '../lang/isArray', './i
         }
       }
       return function() {
-        var args = arguments;
-        if (wrapper && args.length == 1 && isArray(args[0])) {
-          return wrapper.plant(args[0]).value();
+        var args = arguments,
+            value = args[0];
+
+        if (wrapper && args.length == 1 && isArray(value) && value.length >= LARGE_ARRAY_SIZE) {
+          return wrapper.plant(value).value();
         }
         var index = 0,
-            result = length ? funcs[index].apply(this, args) : args[0];
+            result = length ? funcs[index].apply(this, args) : value;
 
         while (++index < length) {
           result = funcs[index].call(this, result);

internal/createHybridWrapper.js

@@ -40,7 +40,7 @@ define(['./arrayCopy', './composeArgs', './composeArgsRight', './createCtorWrapp
         isCurry = bitmask & CURRY_FLAG,
         isCurryBound = bitmask & CURRY_BOUND_FLAG,
         isCurryRight = bitmask & CURRY_RIGHT_FLAG,
-        Ctor = isBindKey ? null : createCtorWrapper(func);
+        Ctor = isBindKey ? undefined : createCtorWrapper(func);
 
     function wrapper() {
       // Avoid `arguments` object use disqualifying optimizations by
@@ -64,12 +64,12 @@ define(['./arrayCopy', './composeArgs', './composeArgsRight', './createCtorWrapp
 
         length -= argsHolders.length;
         if (length < arity) {
-          var newArgPos = argPos ? arrayCopy(argPos) : null,
+          var newArgPos = argPos ? arrayCopy(argPos) : undefined,
               newArity = nativeMax(arity - length, 0),
-              newsHolders = isCurry ? argsHolders : null,
-              newHoldersRight = isCurry ? null : argsHolders,
-              newPartials = isCurry ? args : null,
-              newPartialsRight = isCurry ? null : args;
+              newsHolders = isCurry ? argsHolders : undefined,
+              newHoldersRight = isCurry ? undefined : argsHolders,
+              newPartials = isCurry ? args : undefined,
+              newPartialsRight = isCurry ? undefined : args;
 
           bitmask |= (isCurry ? PARTIAL_FLAG : PARTIAL_RIGHT_FLAG);
           bitmask &= ~(isCurry ? PARTIAL_RIGHT_FLAG : PARTIAL_FLAG);

internal/createPadding.js

@@ -1,10 +1,8 @@
 define(['../string/repeat', './root'], function(repeat, root) {
 
-  /** Native method references. */
-  var ceil = Math.ceil;
-
   /* Native method references for those with the same name as other `lodash` methods. */
-  var nativeIsFinite = root.isFinite;
+  var nativeCeil = Math.ceil,
+      nativeIsFinite = root.isFinite;
 
   /**
    * Creates the padding required for `string` based on the given `length`.
@@ -25,7 +23,7 @@ define(['../string/repeat', './root'], function(repeat, root) {
     }
     var padLength = length - strLength;
     chars = chars == null ? ' ' : (chars + '');
-    return repeat(chars, ceil(padLength / chars.length)).slice(0, padLength);
+    return repeat(chars, nativeCeil(padLength / chars.length)).slice(0, padLength);
   }
 
   return createPadding;

internal/createPartial.js

@@ -1,5 +1,8 @@
 define(['./createWrapper', './replaceHolders', '../function/restParam'], function(createWrapper, replaceHolders, restParam) {
 
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
   /**
    * Creates a `_.partial` or `_.partialRight` function.
    *
@@ -10,7 +13,7 @@ define(['./createWrapper', './replaceHolders', '../function/restParam'], functio
   function createPartial(flag) {
     var partialFunc = restParam(function(func, partials) {
       var holders = replaceHolders(partials, partialFunc.placeholder);
-      return createWrapper(func, flag, null, partials, holders);
+      return createWrapper(func, flag, undefined, partials, holders);
     });
     return partialFunc;
   }

internal/createPartialWrapper.js

@@ -26,7 +26,7 @@ define(['./createCtorWrapper', './root'], function(createCtorWrapper, root) {
           argsLength = arguments.length,
           leftIndex = -1,
           leftLength = partials.length,
-          args = Array(argsLength + leftLength);
+          args = Array(leftLength + argsLength);
 
       while (++leftIndex < leftLength) {
         args[leftIndex] = partials[leftIndex];

internal/createRound.js

@@ -0,0 +1,29 @@
+define([], function() {
+
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
+  /** Native method references. */
+  var pow = Math.pow;
+
+  /**
+   * Creates a `_.ceil`, `_.floor`, or `_.round` function.
+   *
+   * @private
+   * @param {string} methodName The name of the `Math` method to use when rounding.
+   * @returns {Function} Returns the new round function.
+   */
+  function createRound(methodName) {
+    var func = Math[methodName];
+    return function(number, precision) {
+      precision = precision === undefined ? 0 : (+precision || 0);
+      if (precision) {
+        precision = pow(10, precision);
+        return func(number * precision) / precision;
+      }
+      return func(number);
+    };
+  }
+
+  return createRound;
+});

internal/createWrapper.js

@@ -48,16 +48,16 @@ define(['./baseSetData', './createBindWrapper', './createHybridWrapper', './crea
     var length = partials ? partials.length : 0;
     if (!length) {
       bitmask &= ~(PARTIAL_FLAG | PARTIAL_RIGHT_FLAG);
-      partials = holders = null;
+      partials = holders = undefined;
     }
     length -= (holders ? holders.length : 0);
     if (bitmask & PARTIAL_RIGHT_FLAG) {
       var partialsRight = partials,
           holdersRight = holders;
 
-      partials = holders = null;
+      partials = holders = undefined;
     }
-    var data = isBindKey ? null : getData(func),
+    var data = isBindKey ? undefined : getData(func),
         newData = [func, bitmask, thisArg, partials, holders, partialsRight, holdersRight, argPos, ary, arity];
 
     if (data) {

internal/equalByTag.js

@@ -16,7 +16,7 @@ define([], function() {
    * `Boolean`, `Date`, `Error`, `Number`, `RegExp`, or `String`.
    *
    * @private
-   * @param {Object} value The object to compare.
+   * @param {Object} object The object to compare.
    * @param {Object} other The other object to compare.
    * @param {string} tag The `toStringTag` of the objects to compare.
    * @returns {boolean} Returns `true` if the objects are equivalent, else `false`.

internal/escapeRegExpChar.js

@@ -0,0 +1,41 @@
+define([], function() {
+
+  /** Used to escape characters for inclusion in compiled regexes. */
+  var regexpEscapes = {
+    '0': 'x30', '1': 'x31', '2': 'x32', '3': 'x33', '4': 'x34',
+    '5': 'x35', '6': 'x36', '7': 'x37', '8': 'x38', '9': 'x39',
+    'A': 'x41', 'B': 'x42', 'C': 'x43', 'D': 'x44', 'E': 'x45', 'F': 'x46',
+    'a': 'x61', 'b': 'x62', 'c': 'x63', 'd': 'x64', 'e': 'x65', 'f': 'x66',
+    'n': 'x6e', 'r': 'x72', 't': 'x74', 'u': 'x75', 'v': 'x76', 'x': 'x78'
+  };
+
+  /** Used to escape characters for inclusion in compiled string literals. */
+  var stringEscapes = {
+    '\\': '\\',
+    "'": "'",
+    '\n': 'n',
+    '\r': 'r',
+    '\u2028': 'u2028',
+    '\u2029': 'u2029'
+  };
+
+  /**
+   * Used by `_.escapeRegExp` to escape characters for inclusion in compiled regexes.
+   *
+   * @private
+   * @param {string} chr The matched character to escape.
+   * @param {string} leadingChar The capture group for a leading character.
+   * @param {string} whitespaceChar The capture group for a whitespace character.
+   * @returns {string} Returns the escaped character.
+   */
+  function escapeRegExpChar(chr, leadingChar, whitespaceChar) {
+    if (leadingChar) {
+      chr = regexpEscapes[chr];
+    } else if (whitespaceChar) {
+      chr = stringEscapes[chr];
+    }
+    return '\\' + chr;
+  }
+
+  return escapeRegExpChar;
+});

internal/escapeStringChar.js

@@ -11,8 +11,7 @@ define([], function() {
   };
 
   /**
-   * Used by `_.template` to escape characters for inclusion in compiled
-   * string literals.
+   * Used by `_.template` to escape characters for inclusion in compiled string literals.
    *
    * @private
    * @param {string} chr The matched character to escape.

internal/getView.js

@@ -10,13 +10,13 @@ define([], function() {
    * @private
    * @param {number} start The start of the view.
    * @param {number} end The end of the view.
-   * @param {Array} [transforms] The transformations to apply to the view.
+   * @param {Array} transforms The transformations to apply to the view.
    * @returns {Object} Returns an object containing the `start` and `end`
    *  positions of the view.
    */
   function getView(start, end, transforms) {
     var index = -1,
-        length = transforms ? transforms.length : 0;
+        length = transforms.length;
 
     while (++index < length) {
       var data = transforms[index],

internal/isIndex.js

@@ -1,7 +1,10 @@
 define([], function() {
 
+  /** Used to detect unsigned integer values. */
+  var reIsUint = /^\d+$/;
+
   /**
-   * Used as the [maximum length](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-number.max_safe_integer)
+   * Used as the [maximum length](http://ecma-international.org/ecma-262/6.0/#sec-number.max_safe_integer)
    * of an array-like value.
    */
   var MAX_SAFE_INTEGER = 9007199254740991;
@@ -15,7 +18,7 @@ define([], function() {
    * @returns {boolean} Returns `true` if `value` is a valid index, else `false`.
    */
   function isIndex(value, length) {
-    value = typeof value == 'number' ? value : parseFloat(value);
+    value = (typeof value == 'number' || reIsUint.test(value)) ? +value : -1;
     length = length == null ? MAX_SAFE_INTEGER : length;
     return value > -1 && value % 1 == 0 && value < length;
   }

internal/isLength.js

@@ -1,7 +1,7 @@
 define([], function() {
 
   /**
-   * Used as the [maximum length](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-number.max_safe_integer)
+   * Used as the [maximum length](http://ecma-international.org/ecma-262/6.0/#sec-number.max_safe_integer)
    * of an array-like value.
    */
   var MAX_SAFE_INTEGER = 9007199254740991;
@@ -9,7 +9,7 @@ define([], function() {
   /**
    * Checks if `value` is a valid array-like length.
    *
-   * **Note:** This function is based on [`ToLength`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-tolength).
+   * **Note:** This function is based on [`ToLength`](http://ecma-international.org/ecma-262/6.0/#sec-tolength).
    *
    * @private
    * @param {*} value The value to check.

internal/lazyClone.js

@@ -9,17 +9,13 @@ define(['./LazyWrapper', './arrayCopy'], function(LazyWrapper, arrayCopy) {
    * @returns {Object} Returns the cloned `LazyWrapper` object.
    */
   function lazyClone() {
-    var actions = this.__actions__,
-        iteratees = this.__iteratees__,
-        views = this.__views__,
-        result = new LazyWrapper(this.__wrapped__);
-
-    result.__actions__ = actions ? arrayCopy(actions) : null;
+    var result = new LazyWrapper(this.__wrapped__);
+    result.__actions__ = arrayCopy(this.__actions__);
     result.__dir__ = this.__dir__;
     result.__filtered__ = this.__filtered__;
-    result.__iteratees__ = iteratees ? arrayCopy(iteratees) : null;
+    result.__iteratees__ = arrayCopy(this.__iteratees__);
     result.__takeCount__ = this.__takeCount__;
-    result.__views__ = views ? arrayCopy(views) : null;
+    result.__views__ = arrayCopy(this.__views__);
     return result;
   }
 

internal/lazyValue.js

@@ -1,8 +1,10 @@
 define(['./baseWrapperValue', './getView', '../lang/isArray'], function(baseWrapperValue, getView, isArray) {
 
+  /** Used as the size to enable large array optimizations. */
+  var LARGE_ARRAY_SIZE = 200;
+
   /** Used to indicate the type of lazy iteratees. */
-  var LAZY_DROP_WHILE_FLAG = 0,
-      LAZY_FILTER_FLAG = 1,
+  var LAZY_FILTER_FLAG = 1,
       LAZY_MAP_FLAG = 2;
 
   /* Native method references for those with the same name as other `lodash` methods. */
@@ -17,22 +19,25 @@ define(['./baseWrapperValue', './getView', '../lang/isArray'], function(baseWrap
    * @returns {*} Returns the unwrapped value.
    */
   function lazyValue() {
-    var array = this.__wrapped__.value();
-    if (!isArray(array)) {
-      return baseWrapperValue(array, this.__actions__);
-    }
-    var dir = this.__dir__,
+    var array = this.__wrapped__.value(),
+        dir = this.__dir__,
+        isArr = isArray(array),
         isRight = dir < 0,
-        view = getView(0, array.length, this.__views__),
+        arrLength = isArr ? array.length : 0,
+        view = getView(0, arrLength, this.__views__),
         start = view.start,
         end = view.end,
         length = end - start,
         index = isRight ? end : (start - 1),
-        takeCount = nativeMin(length, this.__takeCount__),
         iteratees = this.__iteratees__,
-        iterLength = iteratees ? iteratees.length : 0,
+        iterLength = iteratees.length,
         resIndex = 0,
-        result = [];
+        takeCount = nativeMin(length, this.__takeCount__);
+
+    if (!isArr || arrLength < LARGE_ARRAY_SIZE || (arrLength == length && takeCount == length)) {
+      return baseWrapperValue((isRight && isArr) ? array.reverse() : array, this.__actions__);
+    }
+    var result = [];
 
     outer:
     while (length-- && resIndex < takeCount) {
@@ -44,30 +49,16 @@ define(['./baseWrapperValue', './getView', '../lang/isArray'], function(baseWrap
       while (++iterIndex < iterLength) {
         var data = iteratees[iterIndex],
             iteratee = data.iteratee,
-            type = data.type;
+            type = data.type,
+            computed = iteratee(value);
 
-        if (type == LAZY_DROP_WHILE_FLAG) {
-          if (data.done && (isRight ? (index > data.index) : (index < data.index))) {
-            data.count = 0;
-            data.done = false;
-          }
-          data.index = index;
-          if (!data.done) {
-            var limit = data.limit;
-            if (!(data.done = limit > -1 ? (data.count++ >= limit) : !iteratee(value))) {
-              continue outer;
-            }
-          }
-        } else {
-          var computed = iteratee(value);
-          if (type == LAZY_MAP_FLAG) {
-            value = computed;
-          } else if (!computed) {
-            if (type == LAZY_FILTER_FLAG) {
-              continue outer;
-            } else {
-              break outer;
-            }
+        if (type == LAZY_MAP_FLAG) {
+          value = computed;
+        } else if (!computed) {
+          if (type == LAZY_FILTER_FLAG) {
+            continue outer;
+          } else {
+            break outer;
           }
         }
       }

internal/mergeDefaults.js

@@ -0,0 +1,19 @@
+define(['../object/merge'], function(merge) {
+
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
+  /**
+   * Used by `_.defaultsDeep` to customize its `_.merge` use.
+   *
+   * @private
+   * @param {*} objectValue The destination object property value.
+   * @param {*} sourceValue The source object property value.
+   * @returns {*} Returns the value to assign to the destination object.
+   */
+  function mergeDefaults(objectValue, sourceValue) {
+    return objectValue === undefined ? sourceValue : merge(objectValue, sourceValue, mergeDefaults);
+  }
+
+  return mergeDefaults;
+});

internal/shimIsPlainObject.js

@@ -1,53 +0,0 @@
-define(['./baseForIn', './isObjectLike'], function(baseForIn, isObjectLike) {
-
-  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
-  var undefined;
-
-  /** `Object#toString` result references. */
-  var objectTag = '[object Object]';
-
-  /** Used for native method references. */
-  var objectProto = Object.prototype;
-
-  /** Used to check objects for own properties. */
-  var hasOwnProperty = objectProto.hasOwnProperty;
-
-  /**
-   * Used to resolve the [`toStringTag`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.prototype.tostring)
-   * of values.
-   */
-  var objToString = objectProto.toString;
-
-  /**
-   * A fallback implementation of `_.isPlainObject` which checks if `value`
-   * is an object created by the `Object` constructor or has a `[[Prototype]]`
-   * of `null`.
-   *
-   * @private
-   * @param {*} value The value to check.
-   * @returns {boolean} Returns `true` if `value` is a plain object, else `false`.
-   */
-  function shimIsPlainObject(value) {
-    var Ctor;
-
-    // Exit early for non `Object` objects.
-    if (!(isObjectLike(value) && objToString.call(value) == objectTag) ||
-        (!hasOwnProperty.call(value, 'constructor') &&
-          (Ctor = value.constructor, typeof Ctor == 'function' && !(Ctor instanceof Ctor)))) {
-      return false;
-    }
-    // IE < 9 iterates inherited properties before own properties. If the first
-    // iterated property is an object's own property then there are no inherited
-    // enumerable properties.
-    var result;
-    // In most environments an object's own properties are iterated before
-    // its inherited properties. If the last iterated property is an object's
-    // own property then there are no inherited enumerable properties.
-    baseForIn(value, function(subValue, key) {
-      result = key;
-    });
-    return result === undefined || hasOwnProperty.call(value, result);
-  }
-
-  return shimIsPlainObject;
-});

lang/isArguments.js

@@ -1,16 +1,13 @@
 define(['../internal/isArrayLike', '../internal/isObjectLike'], function(isArrayLike, isObjectLike) {
 
-  /** `Object#toString` result references. */
-  var argsTag = '[object Arguments]';
-
   /** Used for native method references. */
   var objectProto = Object.prototype;
 
-  /**
-   * Used to resolve the [`toStringTag`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.prototype.tostring)
-   * of values.
-   */
-  var objToString = objectProto.toString;
+  /** Used to check objects for own properties. */
+  var hasOwnProperty = objectProto.hasOwnProperty;
+
+  /** Native method references. */
+  var propertyIsEnumerable = objectProto.propertyIsEnumerable;
 
   /**
    * Checks if `value` is classified as an `arguments` object.
@@ -29,7 +26,8 @@ define(['../internal/isArrayLike', '../internal/isObjectLike'], function(isArray
    * // => false
    */
   function isArguments(value) {
-    return isObjectLike(value) && isArrayLike(value) && objToString.call(value) == argsTag;
+    return isObjectLike(value) && isArrayLike(value) &&
+      hasOwnProperty.call(value, 'callee') && !propertyIsEnumerable.call(value, 'callee');
   }
 
   return isArguments;

lang/isArray.js

@@ -7,7 +7,7 @@ define(['../internal/getNative', '../internal/isLength', '../internal/isObjectLi
   var objectProto = Object.prototype;
 
   /**
-   * Used to resolve the [`toStringTag`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.prototype.tostring)
+   * Used to resolve the [`toStringTag`](http://ecma-international.org/ecma-262/6.0/#sec-object.prototype.tostring)
    * of values.
    */
   var objToString = objectProto.toString;

lang/isBoolean.js

@@ -7,7 +7,7 @@ define(['../internal/isObjectLike'], function(isObjectLike) {
   var objectProto = Object.prototype;
 
   /**
-   * Used to resolve the [`toStringTag`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.prototype.tostring)
+   * Used to resolve the [`toStringTag`](http://ecma-international.org/ecma-262/6.0/#sec-object.prototype.tostring)
    * of values.
    */
   var objToString = objectProto.toString;

lang/isDate.js

@@ -7,7 +7,7 @@ define(['../internal/isObjectLike'], function(isObjectLike) {
   var objectProto = Object.prototype;
 
   /**
-   * Used to resolve the [`toStringTag`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.prototype.tostring)
+   * Used to resolve the [`toStringTag`](http://ecma-international.org/ecma-262/6.0/#sec-object.prototype.tostring)
    * of values.
    */
   var objToString = objectProto.toString;

lang/isElement.js

@@ -1,13 +1,4 @@
-define(['../internal/isObjectLike', './isPlainObject', '../support'], function(isObjectLike, isPlainObject, support) {
-
-  /** Used for native method references. */
-  var objectProto = Object.prototype;
-
-  /**
-   * Used to resolve the [`toStringTag`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.prototype.tostring)
-   * of values.
-   */
-  var objToString = objectProto.toString;
+define(['../internal/isObjectLike', './isPlainObject'], function(isObjectLike, isPlainObject) {
 
   /**
    * Checks if `value` is a DOM element.
@@ -26,14 +17,7 @@ define(['../internal/isObjectLike', './isPlainObject', '../support'], function(i
    * // => false
    */
   function isElement(value) {
-    return !!value && value.nodeType === 1 && isObjectLike(value) &&
-      (objToString.call(value).indexOf('Element') > -1);
-  }
-  // Fallback for environments without DOM support.
-  if (!support.dom) {
-    isElement = function(value) {
-      return !!value && value.nodeType === 1 && isObjectLike(value) && !isPlainObject(value);
-    };
+    return !!value && value.nodeType === 1 && isObjectLike(value) && !isPlainObject(value);
   }
 
   return isElement;

lang/isError.js

@@ -7,7 +7,7 @@ define(['../internal/isObjectLike'], function(isObjectLike) {
   var objectProto = Object.prototype;
 
   /**
-   * Used to resolve the [`toStringTag`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.prototype.tostring)
+   * Used to resolve the [`toStringTag`](http://ecma-international.org/ecma-262/6.0/#sec-object.prototype.tostring)
    * of values.
    */
   var objToString = objectProto.toString;

lang/isFinite.js

@@ -1,13 +1,12 @@
-define(['../internal/getNative', '../internal/root'], function(getNative, root) {
+define(['../internal/root'], function(root) {
 
   /* Native method references for those with the same name as other `lodash` methods. */
-  var nativeIsFinite = root.isFinite,
-      nativeNumIsFinite = getNative(Number, 'isFinite');
+  var nativeIsFinite = root.isFinite;
 
   /**
    * Checks if `value` is a finite primitive number.
    *
-   * **Note:** This method is based on [`Number.isFinite`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-number.isfinite).
+   * **Note:** This method is based on [`Number.isFinite`](http://ecma-international.org/ecma-262/6.0/#sec-number.isfinite).
    *
    * @static
    * @memberOf _
@@ -31,9 +30,9 @@ define(['../internal/getNative', '../internal/root'], function(getNative, root)
    * _.isFinite(Infinity);
    * // => false
    */
-  var isFinite = nativeNumIsFinite || function(value) {
+  function isFinite(value) {
     return typeof value == 'number' && nativeIsFinite(value);
-  };
+  }
 
   return isFinite;
 });

lang/isFunction.js

@@ -1,4 +1,4 @@
-define(['../internal/baseIsFunction', '../internal/getNative', '../internal/root'], function(baseIsFunction, getNative, root) {
+define(['./isObject'], function(isObject) {
 
   /** `Object#toString` result references. */
   var funcTag = '[object Function]';
@@ -7,14 +7,11 @@ define(['../internal/baseIsFunction', '../internal/getNative', '../internal/root
   var objectProto = Object.prototype;
 
   /**
-   * Used to resolve the [`toStringTag`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.prototype.tostring)
+   * Used to resolve the [`toStringTag`](http://ecma-international.org/ecma-262/6.0/#sec-object.prototype.tostring)
    * of values.
    */
   var objToString = objectProto.toString;
 
-  /** Native method references. */
-  var Uint8Array = getNative(root, 'Uint8Array');
-
   /**
    * Checks if `value` is classified as a `Function` object.
    *
@@ -31,12 +28,12 @@ define(['../internal/baseIsFunction', '../internal/getNative', '../internal/root
    * _.isFunction(/abc/);
    * // => false
    */
-  var isFunction = !(baseIsFunction(/x/) || (Uint8Array && !baseIsFunction(Uint8Array))) ? baseIsFunction : function(value) {
+  function isFunction(value) {
     // The use of `Object#toString` avoids issues with the `typeof` operator
     // in older versions of Chrome and Safari which return 'function' for regexes
     // and Safari 8 equivalents which return 'object' for typed array constructors.
-    return objToString.call(value) == funcTag;
-  };
+    return isObject(value) && objToString.call(value) == funcTag;
+  }
 
   return isFunction;
 });

lang/isNative.js

@@ -1,7 +1,4 @@
-define(['../string/escapeRegExp', '../internal/isObjectLike'], function(escapeRegExp, isObjectLike) {
-
-  /** `Object#toString` result references. */
-  var funcTag = '[object Function]';
+define(['./isFunction', '../internal/isObjectLike'], function(isFunction, isObjectLike) {
 
   /** Used to detect host constructors (Safari > 5). */
   var reIsHostCtor = /^\[object .+?Constructor\]$/;
@@ -15,15 +12,9 @@ define(['../string/escapeRegExp', '../internal/isObjectLike'], function(escapeRe
   /** Used to check objects for own properties. */
   var hasOwnProperty = objectProto.hasOwnProperty;
 
-  /**
-   * Used to resolve the [`toStringTag`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.prototype.tostring)
-   * of values.
-   */
-  var objToString = objectProto.toString;
-
   /** Used to detect if a method is native. */
   var reIsNative = RegExp('^' +
-    escapeRegExp(fnToString.call(hasOwnProperty))
+    fnToString.call(hasOwnProperty).replace(/[\\^$.*+?()[\]{}|]/g, '\\$&')
     .replace(/hasOwnProperty|(function).*?(?=\\\()| for .+?(?=\\\])/g, '$1.*?') + '$'
   );
 
@@ -47,7 +38,7 @@ define(['../string/escapeRegExp', '../internal/isObjectLike'], function(escapeRe
     if (value == null) {
       return false;
     }
-    if (objToString.call(value) == funcTag) {
+    if (isFunction(value)) {
       return reIsNative.test(fnToString.call(value));
     }
     return isObjectLike(value) && reIsHostCtor.test(value);

lang/isNumber.js

@@ -7,7 +7,7 @@ define(['../internal/isObjectLike'], function(isObjectLike) {
   var objectProto = Object.prototype;
 
   /**
-   * Used to resolve the [`toStringTag`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.prototype.tostring)
+   * Used to resolve the [`toStringTag`](http://ecma-international.org/ecma-262/6.0/#sec-object.prototype.tostring)
    * of values.
    */
   var objToString = objectProto.toString;

lang/isPlainObject.js

@@ -1,4 +1,7 @@
-define(['../internal/getNative', '../internal/shimIsPlainObject'], function(getNative, shimIsPlainObject) {
+define(['../internal/baseForIn', './isArguments', '../internal/isObjectLike'], function(baseForIn, isArguments, isObjectLike) {
+
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
 
   /** `Object#toString` result references. */
   var objectTag = '[object Object]';
@@ -6,15 +9,15 @@ define(['../internal/getNative', '../internal/shimIsPlainObject'], function(getN
   /** Used for native method references. */
   var objectProto = Object.prototype;
 
+  /** Used to check objects for own properties. */
+  var hasOwnProperty = objectProto.hasOwnProperty;
+
   /**
-   * Used to resolve the [`toStringTag`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.prototype.tostring)
+   * Used to resolve the [`toStringTag`](http://ecma-international.org/ecma-262/6.0/#sec-object.prototype.tostring)
    * of values.
    */
   var objToString = objectProto.toString;
 
-  /** Native method references. */
-  var getPrototypeOf = getNative(Object, 'getPrototypeOf');
-
   /**
    * Checks if `value` is a plain object, that is, an object created by the
    * `Object` constructor or one with a `[[Prototype]]` of `null`.
@@ -45,17 +48,26 @@ define(['../internal/getNative', '../internal/shimIsPlainObject'], function(getN
    * _.isPlainObject(Object.create(null));
    * // => true
    */
-  var isPlainObject = !getPrototypeOf ? shimIsPlainObject : function(value) {
-    if (!(value && objToString.call(value) == objectTag)) {
+  function isPlainObject(value) {
+    var Ctor;
+
+    // Exit early for non `Object` objects.
+    if (!(isObjectLike(value) && objToString.call(value) == objectTag && !isArguments(value)) ||
+        (!hasOwnProperty.call(value, 'constructor') && (Ctor = value.constructor, typeof Ctor == 'function' && !(Ctor instanceof Ctor)))) {
       return false;
     }
-    var valueOf = getNative(value, 'valueOf'),
-        objProto = valueOf && (objProto = getPrototypeOf(valueOf)) && getPrototypeOf(objProto);
-
-    return objProto
-      ? (value == objProto || getPrototypeOf(value) == objProto)
-      : shimIsPlainObject(value);
-  };
+    // IE < 9 iterates inherited properties before own properties. If the first
+    // iterated property is an object's own property then there are no inherited
+    // enumerable properties.
+    var result;
+    // In most environments an object's own properties are iterated before
+    // its inherited properties. If the last iterated property is an object's
+    // own property then there are no inherited enumerable properties.
+    baseForIn(value, function(subValue, key) {
+      result = key;
+    });
+    return result === undefined || hasOwnProperty.call(value, result);
+  }
 
   return isPlainObject;
 });

lang/isRegExp.js

@@ -1,4 +1,4 @@
-define(['../internal/isObjectLike'], function(isObjectLike) {
+define(['./isObject'], function(isObject) {
 
   /** `Object#toString` result references. */
   var regexpTag = '[object RegExp]';
@@ -7,7 +7,7 @@ define(['../internal/isObjectLike'], function(isObjectLike) {
   var objectProto = Object.prototype;
 
   /**
-   * Used to resolve the [`toStringTag`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.prototype.tostring)
+   * Used to resolve the [`toStringTag`](http://ecma-international.org/ecma-262/6.0/#sec-object.prototype.tostring)
    * of values.
    */
   var objToString = objectProto.toString;
@@ -29,7 +29,7 @@ define(['../internal/isObjectLike'], function(isObjectLike) {
    * // => false
    */
   function isRegExp(value) {
-    return isObjectLike(value) && objToString.call(value) == regexpTag;
+    return isObject(value) && objToString.call(value) == regexpTag;
   }
 
   return isRegExp;

lang/isString.js

@@ -7,7 +7,7 @@ define(['../internal/isObjectLike'], function(isObjectLike) {
   var objectProto = Object.prototype;
 
   /**
-   * Used to resolve the [`toStringTag`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.prototype.tostring)
+   * Used to resolve the [`toStringTag`](http://ecma-international.org/ecma-262/6.0/#sec-object.prototype.tostring)
    * of values.
    */
   var objToString = objectProto.toString;

lang/isTypedArray.js

@@ -45,7 +45,7 @@ define(['../internal/isLength', '../internal/isObjectLike'], function(isLength,
   var objectProto = Object.prototype;
 
   /**
-   * Used to resolve the [`toStringTag`](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.prototype.tostring)
+   * Used to resolve the [`toStringTag`](http://ecma-international.org/ecma-262/6.0/#sec-object.prototype.tostring)
    * of values.
    */
   var objToString = objectProto.toString;

math.js

@@ -1,8 +1,11 @@
-define(['./math/add', './math/max', './math/min', './math/sum'], function(add, max, min, sum) {
+define(['./math/add', './math/ceil', './math/floor', './math/max', './math/min', './math/round', './math/sum'], function(add, ceil, floor, max, min, round, sum) {
   return {
     'add': add,
+    'ceil': ceil,
+    'floor': floor,
     'max': max,
     'min': min,
+    'round': round,
     'sum': sum
   };
 });

math/ceil.js

@@ -0,0 +1,26 @@
+define(['../internal/createRound'], function(createRound) {
+
+  /**
+   * Calculates `n` rounded up to `precision`.
+   *
+   * @static
+   * @memberOf _
+   * @category Math
+   * @param {number} n The number to round up.
+   * @param {number} [precision=0] The precision to round up to.
+   * @returns {number} Returns the rounded up number.
+   * @example
+   *
+   * _.ceil(4.006);
+   * // => 5
+   *
+   * _.ceil(6.004, 2);
+   * // => 6.01
+   *
+   * _.ceil(6040, -2);
+   * // => 6100
+   */
+  var ceil = createRound('ceil');
+
+  return ceil;
+});

math/floor.js

@@ -0,0 +1,26 @@
+define(['../internal/createRound'], function(createRound) {
+
+  /**
+   * Calculates `n` rounded down to `precision`.
+   *
+   * @static
+   * @memberOf _
+   * @category Math
+   * @param {number} n The number to round down.
+   * @param {number} [precision=0] The precision to round down to.
+   * @returns {number} Returns the rounded down number.
+   * @example
+   *
+   * _.floor(4.006);
+   * // => 4
+   *
+   * _.floor(0.046, 2);
+   * // => 0.04
+   *
+   * _.floor(4060, -2);
+   * // => 4000
+   */
+  var floor = createRound('floor');
+
+  return floor;
+});

math/round.js

@@ -0,0 +1,26 @@
+define(['../internal/createRound'], function(createRound) {
+
+  /**
+   * Calculates `n` rounded to `precision`.
+   *
+   * @static
+   * @memberOf _
+   * @category Math
+   * @param {number} n The number to round.
+   * @param {number} [precision=0] The precision to round to.
+   * @returns {number} Returns the rounded number.
+   * @example
+   *
+   * _.round(4.006);
+   * // => 4
+   *
+   * _.round(4.006, 2);
+   * // => 4.01
+   *
+   * _.round(4060, -2);
+   * // => 4100
+   */
+  var round = createRound('round');
+
+  return round;
+});

math/sum.js

@@ -1,5 +1,8 @@
 define(['../internal/arraySum', '../internal/baseCallback', '../internal/baseSum', '../lang/isArray', '../internal/isIterateeCall', '../internal/toIterable'], function(arraySum, baseCallback, baseSum, isArray, isIterateeCall, toIterable) {
 
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
   /**
    * Gets the sum of the values in `collection`.
    *
@@ -34,13 +37,11 @@ define(['../internal/arraySum', '../internal/baseCallback', '../internal/baseSum
    */
   function sum(collection, iteratee, thisArg) {
     if (thisArg && isIterateeCall(collection, iteratee, thisArg)) {
-      iteratee = null;
+      iteratee = undefined;
     }
-    var noIteratee = iteratee == null;
-
-    iteratee = noIteratee ? iteratee : baseCallback(iteratee, thisArg, 3);
-    return noIteratee
-      ? arraySum(isArray(collection) ? collection : toIterable(collection))
+    iteratee = baseCallback(iteratee, thisArg, 3);
+    return iteratee.length == 1
+      ? arraySum(isArray(collection) ? collection : toIterable(collection), iteratee)
       : baseSum(collection, iteratee);
   }
 

number/inRange.js

@@ -1,5 +1,8 @@
 define([], function() {
 
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
   /* Native method references for those with the same name as other `lodash` methods. */
   var nativeMax = Math.max,
       nativeMin = Math.min;
@@ -37,7 +40,7 @@ define([], function() {
    */
   function inRange(value, start, end) {
     start = +start || 0;
-    if (typeof end === 'undefined') {
+    if (end === undefined) {
       end = start;
       start = 0;
     } else {

number/random.js

@@ -1,5 +1,8 @@
 define(['../internal/baseRandom', '../internal/isIterateeCall'], function(baseRandom, isIterateeCall) {
 
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
   /* Native method references for those with the same name as other `lodash` methods. */
   var nativeMin = Math.min,
       nativeRandom = Math.random;
@@ -33,7 +36,7 @@ define(['../internal/baseRandom', '../internal/isIterateeCall'], function(baseRa
    */
   function random(min, max, floating) {
     if (floating && isIterateeCall(min, max, floating)) {
-      max = floating = null;
+      max = floating = undefined;
     }
     var noMin = min == null,
         noMax = max == null;