(function() {\ -
\ - Normalize results \ -
| ' + platform + ' | |
|---|---|
| Test | Ops/sec |
Underscore.js 1.5.2
-http://underscorejs.org
-(c) 2009-2013 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
-Underscore may be freely distributed under the MIT license.Underscore.js 1.8.3
+http://underscorejs.org
+(c) 2009-2017 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
+Underscore may be freely distributed under the MIT license.
+(function() {
+(function() {Establish the root object, window in the browser, or exports on the server.
var root = this;Save the previous value of the _ variable.
Establish the root object, window in the browser, or exports on the server.
var previousUnderscore = root._; var root = this;Establish the object that gets returned to break out of a loop iteration.
+Save the previous value of the _ variable.
var breaker = {}; var previousUnderscore = root._; var ArrayProto = Array.prototype, ObjProto = Object.prototype, FuncProto = Function.prototype; var ArrayProto = Array.prototype, ObjProto = Object.prototype, FuncProto = Function.prototype; var
+ var
push = ArrayProto.push,
slice = ArrayProto.slice,
- concat = ArrayProto.concat,
toString = ObjProto.toString,
hasOwnProperty = ObjProto.hasOwnProperty;
@@ -143,19 +140,11 @@ are declared here.
var
- nativeForEach = ArrayProto.forEach,
- nativeMap = ArrayProto.map,
- nativeReduce = ArrayProto.reduce,
- nativeReduceRight = ArrayProto.reduceRight,
- nativeFilter = ArrayProto.filter,
- nativeEvery = ArrayProto.every,
- nativeSome = ArrayProto.some,
- nativeIndexOf = ArrayProto.indexOf,
- nativeLastIndexOf = ArrayProto.lastIndexOf,
- nativeIsArray = Array.isArray,
- nativeKeys = Object.keys,
- nativeBind = FuncProto.bind; var
+ nativeIsArray = Array.isArray,
+ nativeKeys = Object.keys,
+ nativeBind = FuncProto.bind,
+ nativeCreate = Object.create;Create a safe reference to the Underscore object for use below.
+Naked function reference for surrogate-prototype-swapping.
var _ = function(obj) {
- if (obj instanceof _) return obj;
- if (!(this instanceof _)) return new _(obj);
- this._wrapped = obj;
- }; var Ctor = function(){};Export the Underscore object for Node.js, with
-backwards-compatibility for the old require() API. If we're in
-the browser, add _ as a global object via a string identifier,
-for Closure Compiler "advanced" mode.
Create a safe reference to the Underscore object for use below.
- if (typeof exports !== 'undefined') {
- if (typeof module !== 'undefined' && module.exports) {
- exports = module.exports = _;
- }
- exports._ = _;
- } else {
- root._ = _;
- } var _ = function(obj) {
+ if (obj instanceof _) return obj;
+ if (!(this instanceof _)) return new _(obj);
+ this._wrapped = obj;
+ };Current version.
+Export the Underscore object for Node.js, with
+backwards-compatibility for the old require() API. If we’re in
+the browser, add _ as a global object.
_.VERSION = '1.5.2'; if (typeof exports !== 'undefined') {
+ if (typeof module !== 'undefined' && module.exports) {
+ exports = module.exports = _;
+ }
+ exports._ = _;
+ } else {
+ root._ = _;
+ } _.VERSION = '1.8.3';The cornerstone, an each implementation, aka forEach.
-Handles objects with the built-in forEach, arrays, and raw objects.
-Delegates to ECMAScript 5's native forEach if available.
Internal function that returns an efficient (for current engines) version +of the passed-in callback, to be repeatedly applied in other Underscore +functions.
var each = _.each = _.forEach = function(obj, iterator, context) {
- if (obj == null) return;
- if (nativeForEach && obj.forEach === nativeForEach) {
- obj.forEach(iterator, context);
- } else if (obj.length === +obj.length) {
- for (var i = 0, length = obj.length; i < length; i++) {
- if (iterator.call(context, obj[i], i, obj) === breaker) return;
- }
- } else {
- var keys = _.keys(obj);
- for (var i = 0, length = keys.length; i < length; i++) {
- if (iterator.call(context, obj[keys[i]], keys[i], obj) === breaker) return;
- }
+ var optimizeCb = function(func, context, argCount) {
+ if (context === void 0) return func;
+ switch (argCount == null ? 3 : argCount) {
+ case 1: return function(value) {
+ return func.call(context, value);
+ };
+ case 2: return function(value, other) {
+ return func.call(context, value, other);
+ };
+ case 3: return function(value, index, collection) {
+ return func.call(context, value, index, collection);
+ };
+ case 4: return function(accumulator, value, index, collection) {
+ return func.call(context, accumulator, value, index, collection);
+ };
}
+ return function() {
+ return func.apply(context, arguments);
+ };
};
@@ -269,22 +264,21 @@ Delegates to ECMAScript 5's native forEach if
- Return the results of applying the iterator to each element.
-Delegates to ECMAScript 5's native map if available.
+ A mostly-internal function to generate callbacks that can be applied
+to each element in a collection, returning the desired result — either
+identity, an arbitrary callback, a property matcher, or a property accessor.
_.map = _.collect = function(obj, iterator, context) {
- var results = [];
- if (obj == null) return results;
- if (nativeMap && obj.map === nativeMap) return obj.map(iterator, context);
- each(obj, function(value, index, list) {
- results.push(iterator.call(context, value, index, list));
- });
- return results;
+ var cb = function(value, context, argCount) {
+ if (value == null) return _.identity;
+ if (_.isFunction(value)) return optimizeCb(value, context, argCount);
+ if (_.isObject(value)) return _.matcher(value);
+ return _.property(value);
};
-
- var reduceError = 'Reduce of empty array with no initial value';
+ _.iteratee = function(value, context) {
+ return cb(value, context, Infinity);
+ };map if avai
- Reduce builds up a single result from a list of values, aka inject,
-or foldl. Delegates to ECMAScript 5's native reduce if available.
An internal function for creating assigner functions.
_.reduce = _.foldl = _.inject = function(obj, iterator, memo, context) {
- var initial = arguments.length > 2;
- if (obj == null) obj = [];
- if (nativeReduce && obj.reduce === nativeReduce) {
- if (context) iterator = _.bind(iterator, context);
- return initial ? obj.reduce(iterator, memo) : obj.reduce(iterator);
- }
- each(obj, function(value, index, list) {
- if (!initial) {
- memo = value;
- initial = true;
- } else {
- memo = iterator.call(context, memo, value, index, list);
+ var createAssigner = function(keysFunc, undefinedOnly) {
+ return function(obj) {
+ var length = arguments.length;
+ if (length < 2 || obj == null) return obj;
+ for (var index = 1; index < length; index++) {
+ var source = arguments[index],
+ keys = keysFunc(source),
+ l = keys.length;
+ for (var i = 0; i < l; i++) {
+ var key = keys[i];
+ if (!undefinedOnly || obj[key] === void 0) obj[key] = source[key];
+ }
}
- });
- if (!initial) throw new TypeError(reduceError);
- return memo;
+ return obj;
+ };
};
@@ -328,34 +319,23 @@ or foldl. Delegates to ECMAScript 5's native <
- The right-associative version of reduce, also known as foldr.
-Delegates to ECMAScript 5's native reduceRight if available.
+ An internal function for creating a new object that inherits from another.
_.reduceRight = _.foldr = function(obj, iterator, memo, context) {
- var initial = arguments.length > 2;
- if (obj == null) obj = [];
- if (nativeReduceRight && obj.reduceRight === nativeReduceRight) {
- if (context) iterator = _.bind(iterator, context);
- return initial ? obj.reduceRight(iterator, memo) : obj.reduceRight(iterator);
- }
- var length = obj.length;
- if (length !== +length) {
- var keys = _.keys(obj);
- length = keys.length;
- }
- each(obj, function(value, index, list) {
- index = keys ? keys[--length] : --length;
- if (!initial) {
- memo = obj[index];
- initial = true;
- } else {
- memo = iterator.call(context, memo, obj[index], index, list);
- }
- });
- if (!initial) throw new TypeError(reduceError);
- return memo;
+ var baseCreate = function(prototype) {
+ if (!_.isObject(prototype)) return {};
+ if (nativeCreate) return nativeCreate(prototype);
+ Ctor.prototype = prototype;
+ var result = new Ctor;
+ Ctor.prototype = null;
+ return result;
+ };
+
+ var property = function(key) {
+ return function(obj) {
+ return obj == null ? void 0 : obj[key];
+ };
};
@@ -367,19 +347,18 @@ Delegates to ECMAScript 5's native reduceRight
- Return the first value which passes a truth test. Aliased as detect.
+ Helper for collection methods to determine whether a collection
+should be iterated as an array or as an object
+Related: http://people.mozilla.org/~jorendorff/es6-draft.html#sec-tolength
+Avoids a very nasty iOS 8 JIT bug on ARM-64. #2094
_.find = _.detect = function(obj, iterator, context) {
- var result;
- any(obj, function(value, index, list) {
- if (iterator.call(context, value, index, list)) {
- result = value;
- return true;
- }
- });
- return result;
+ var MAX_ARRAY_INDEX = Math.pow(2, 53) - 1;
+ var getLength = property('length');
+ var isArrayLike = function(collection) {
+ var length = getLength(collection);
+ return typeof length == 'number' && length >= 0 && length <= MAX_ARRAY_INDEX;
};
@@ -391,22 +370,10 @@ Delegates to ECMAScript 5's native reduceRight
- Return all the elements that pass a truth test.
-Delegates to ECMAScript 5's native filter if available.
-Aliased as select.
+ Collection Functions
_.filter = _.select = function(obj, iterator, context) {
- var results = [];
- if (obj == null) return results;
- if (nativeFilter && obj.filter === nativeFilter) return obj.filter(iterator, context);
- each(obj, function(value, index, list) {
- if (iterator.call(context, value, index, list)) results.push(value);
- });
- return results;
- };select.
- Return all the elements for which a truth test fails.
- + _.reject = function(obj, iterator, context) {
- return _.filter(obj, function(value, index, list) {
- return !iterator.call(context, value, index, list);
- }, context);
- };select.
- Determine whether all of the elements match a truth test.
-Delegates to ECMAScript 5's native every if available.
-Aliased as all.
The cornerstone, an each implementation, aka forEach.
+Handles raw objects in addition to array-likes. Treats all
+sparse array-likes as if they were dense.
_.every = _.all = function(obj, iterator, context) {
- iterator || (iterator = _.identity);
- var result = true;
- if (obj == null) return result;
- if (nativeEvery && obj.every === nativeEvery) return obj.every(iterator, context);
- each(obj, function(value, index, list) {
- if (!(result = result && iterator.call(context, value, index, list))) return breaker;
- });
- return !!result;
+ _.each = _.forEach = function(obj, iteratee, context) {
+ iteratee = optimizeCb(iteratee, context);
+ var i, length;
+ if (isArrayLike(obj)) {
+ for (i = 0, length = obj.length; i < length; i++) {
+ iteratee(obj[i], i, obj);
+ }
+ } else {
+ var keys = _.keys(obj);
+ for (i = 0, length = keys.length; i < length; i++) {
+ iteratee(obj[keys[i]], keys[i], obj);
+ }
+ }
+ return obj;
};
@@ -461,21 +426,20 @@ Aliased as all.
- Determine if at least one element in the object matches a truth test.
-Delegates to ECMAScript 5's native some if available.
-Aliased as any.
+ Return the results of applying the iteratee to each element.
var any = _.some = _.any = function(obj, iterator, context) {
- iterator || (iterator = _.identity);
- var result = false;
- if (obj == null) return result;
- if (nativeSome && obj.some === nativeSome) return obj.some(iterator, context);
- each(obj, function(value, index, list) {
- if (result || (result = iterator.call(context, value, index, list))) return breaker;
- });
- return !!result;
+ _.map = _.collect = function(obj, iteratee, context) {
+ iteratee = cb(iteratee, context);
+ var keys = !isArrayLike(obj) && _.keys(obj),
+ length = (keys || obj).length,
+ results = Array(length);
+ for (var index = 0; index < length; index++) {
+ var currentKey = keys ? keys[index] : index;
+ results[index] = iteratee(obj[currentKey], currentKey, obj);
+ }
+ return results;
};
@@ -487,18 +451,11 @@ Aliased as any.
- Determine if the array or object contains a given value (using ===).
-Aliased as include.
+ Create a reducing function iterating left or right.
_.contains = _.include = function(obj, target) {
- if (obj == null) return false;
- if (nativeIndexOf && obj.indexOf === nativeIndexOf) return obj.indexOf(target) != -1;
- return any(obj, function(value) {
- return value === target;
- });
- }; function createReduce(dir) {include.
- Invoke a method (with arguments) on every item in a collection.
+Optimized iterator function as using arguments.length +in the main function will deoptimize the, see #1991.
_.invoke = function(obj, method) {
- var args = slice.call(arguments, 2);
- var isFunc = _.isFunction(method);
- return _.map(obj, function(value) {
- return (isFunc ? method : value[method]).apply(value, args);
- });
- }; function iterator(obj, iteratee, memo, keys, index, length) {
+ for (; index >= 0 && index < length; index += dir) {
+ var currentKey = keys ? keys[index] : index;
+ memo = iteratee(memo, obj[currentKey], currentKey, obj);
+ }
+ return memo;
+ }
+
+ return function(obj, iteratee, memo, context) {
+ iteratee = optimizeCb(iteratee, context, 4);
+ var keys = !isArrayLike(obj) && _.keys(obj),
+ length = (keys || obj).length,
+ index = dir > 0 ? 0 : length - 1;include.
- Convenience version of a common use case of map: fetching a property.
Determine the initial value if none is provided.
_.pluck = function(obj, key) {
- return _.map(obj, function(value){ return value[key]; });
- }; if (arguments.length < 3) {
+ memo = obj[keys ? keys[index] : index];
+ index += dir;
+ }
+ return iterator(obj, iteratee, memo, keys, index, length);
+ };
+ }include.
- Convenience version of a common use case of filter: selecting only objects
-containing specific key:value pairs.
Reduce builds up a single result from a list of values, aka inject,
+or foldl.
_.where = function(obj, attrs, first) {
- if (_.isEmpty(attrs)) return first ? void 0 : [];
- return _[first ? 'find' : 'filter'](obj, function(value) {
- for (var key in attrs) {
- if (attrs[key] !== value[key]) return false;
- }
- return true;
- });
- }; _.reduce = _.foldl = _.inject = createReduce(1);key:value pairs.
- Convenience version of a common use case of find: getting the first object
-containing specific key:value pairs.
The right-associative version of reduce, also known as foldr.
_.findWhere = function(obj, attrs) {
- return _.where(obj, attrs, true);
- }; _.reduceRight = _.foldr = createReduce(-1);key:value pairs.
- Return the maximum element or (element-based computation). -Can't optimize arrays of integers longer than 65,535 elements. -See WebKit Bug 80797
+Return the first value which passes a truth test. Aliased as detect.
_.max = function(obj, iterator, context) {
- if (!iterator && _.isArray(obj) && obj[0] === +obj[0] && obj.length < 65535) {
- return Math.max.apply(Math, obj);
+ _.find = _.detect = function(obj, predicate, context) {
+ var key;
+ if (isArrayLike(obj)) {
+ key = _.findIndex(obj, predicate, context);
+ } else {
+ key = _.findKey(obj, predicate, context);
}
- if (!iterator && _.isEmpty(obj)) return -Infinity;
- var result = {computed : -Infinity, value: -Infinity};
- each(obj, function(value, index, list) {
- var computed = iterator ? iterator.call(context, value, index, list) : value;
- computed > result.computed && (result = {value : value, computed : computed});
- });
- return result.value;
+ if (key !== void 0 && key !== -1) return obj[key];
};
@@ -617,21 +569,18 @@ See WebKit Bug 80797
- Return the minimum element (or element-based computation).
+ Return all the elements that pass a truth test.
+Aliased as select.
_.min = function(obj, iterator, context) {
- if (!iterator && _.isArray(obj) && obj[0] === +obj[0] && obj.length < 65535) {
- return Math.min.apply(Math, obj);
- }
- if (!iterator && _.isEmpty(obj)) return Infinity;
- var result = {computed : Infinity, value: Infinity};
- each(obj, function(value, index, list) {
- var computed = iterator ? iterator.call(context, value, index, list) : value;
- computed < result.computed && (result = {value : value, computed : computed});
+ _.filter = _.select = function(obj, predicate, context) {
+ var results = [];
+ predicate = cb(predicate, context);
+ _.each(obj, function(value, index, list) {
+ if (predicate(value, index, list)) results.push(value);
});
- return result.value;
+ return results;
};
@@ -643,21 +592,12 @@ See WebKit Bug 80797
- Shuffle an array, using the modern version of the
-Fisher-Yates shuffle.
+ Return all the elements for which a truth test fails.
_.shuffle = function(obj) {
- var rand;
- var index = 0;
- var shuffled = [];
- each(obj, function(value) {
- rand = _.random(index++);
- shuffled[index - 1] = shuffled[rand];
- shuffled[rand] = value;
- });
- return shuffled;
+ _.reject = function(obj, predicate, context) {
+ return _.filter(obj, _.negate(cb(predicate)), context);
};
@@ -669,17 +609,20 @@ See WebKit Bug 80797
- Sample n random values from an array.
-If n is not specified, returns a single random element from the array.
-The internal guard argument allows it to work with map.
+ Determine whether all of the elements match a truth test.
+Aliased as all.
_.sample = function(obj, n, guard) {
- if (arguments.length < 2 || guard) {
- return obj[_.random(obj.length - 1)];
+ _.every = _.all = function(obj, predicate, context) {
+ predicate = cb(predicate, context);
+ var keys = !isArrayLike(obj) && _.keys(obj),
+ length = (keys || obj).length;
+ for (var index = 0; index < length; index++) {
+ var currentKey = keys ? keys[index] : index;
+ if (!predicate(obj[currentKey], currentKey, obj)) return false;
}
- return _.shuffle(obj).slice(0, Math.max(0, n));
+ return true;
};
@@ -691,12 +634,20 @@ The internal guard argument allows it to work with map
- An internal function to generate lookup iterators.
+ Determine if at least one element in the object matches a truth test.
+Aliased as any.
var lookupIterator = function(value) {
- return _.isFunction(value) ? value : function(obj){ return obj[value]; };
+ _.some = _.any = function(obj, predicate, context) {
+ predicate = cb(predicate, context);
+ var keys = !isArrayLike(obj) && _.keys(obj),
+ length = (keys || obj).length;
+ for (var index = 0; index < length; index++) {
+ var currentKey = keys ? keys[index] : index;
+ if (predicate(obj[currentKey], currentKey, obj)) return true;
+ }
+ return false;
};
@@ -708,27 +659,15 @@ The internal guard argument allows it to work with map
- Sort the object's values by a criterion produced by an iterator.
+ Determine if the array or object contains a given item (using ===).
+Aliased as includes and include.
_.sortBy = function(obj, value, context) {
- var iterator = lookupIterator(value);
- return _.pluck(_.map(obj, function(value, index, list) {
- return {
- value: value,
- index: index,
- criteria: iterator.call(context, value, index, list)
- };
- }).sort(function(left, right) {
- var a = left.criteria;
- var b = right.criteria;
- if (a !== b) {
- if (a > b || a === void 0) return 1;
- if (a < b || b === void 0) return -1;
- }
- return left.index - right.index;
- }), 'value');
+ _.contains = _.includes = _.include = function(obj, item, fromIndex, guard) {
+ if (!isArrayLike(obj)) obj = _.values(obj);
+ if (typeof fromIndex != 'number' || guard) fromIndex = 0;
+ return _.indexOf(obj, item, fromIndex) >= 0;
};
@@ -740,20 +679,17 @@ The internal guard argument allows it to work with map
- An internal function used for aggregate "group by" operations.
+ Invoke a method (with arguments) on every item in a collection.
var group = function(behavior) {
- return function(obj, value, context) {
- var result = {};
- var iterator = value == null ? _.identity : lookupIterator(value);
- each(obj, function(value, index) {
- var key = iterator.call(context, value, index, obj);
- behavior(result, key, value);
- });
- return result;
- };
+ _.invoke = function(obj, method) {
+ var args = slice.call(arguments, 2);
+ var isFunc = _.isFunction(method);
+ return _.map(obj, function(value) {
+ var func = isFunc ? method : value[method];
+ return func == null ? func : func.apply(value, args);
+ });
};
@@ -765,14 +701,13 @@ The internal guard argument allows it to work with map
- Groups the object's values by a criterion. Pass either a string attribute
-to group by, or a function that returns the criterion.
+ Convenience version of a common use case of map: fetching a property.
_.groupBy = group(function(result, key, value) {
- (_.has(result, key) ? result[key] : (result[key] = [])).push(value);
- }); _.pluck = function(obj, key) {
+ return _.map(obj, _.property(key));
+ };Indexes the object's values by a criterion, similar to groupBy, but for
-when you know that your index values will be unique.
Convenience version of a common use case of filter: selecting only objects
+containing specific key:value pairs.
_.indexBy = group(function(result, key, value) {
- result[key] = value;
- }); _.where = function(obj, attrs) {
+ return _.filter(obj, _.matcher(attrs));
+ };Counts instances of an object that group by a certain criterion. Pass -either a string attribute to count by, or a function that returns the -criterion.
+Convenience version of a common use case of find: getting the first object
+containing specific key:value pairs.
_.countBy = group(function(result, key) {
- _.has(result, key) ? result[key]++ : result[key] = 1;
- }); _.findWhere = function(obj, attrs) {
+ return _.find(obj, _.matcher(attrs));
+ };Use a comparator function to figure out the smallest index at which -an object should be inserted so as to maintain order. Uses binary search.
+Return the maximum element (or element-based computation).
_.sortedIndex = function(array, obj, iterator, context) {
- iterator = iterator == null ? _.identity : lookupIterator(iterator);
- var value = iterator.call(context, obj);
- var low = 0, high = array.length;
- while (low < high) {
- var mid = (low + high) >>> 1;
- iterator.call(context, array[mid]) < value ? low = mid + 1 : high = mid;
+ _.max = function(obj, iteratee, context) {
+ var result = -Infinity, lastComputed = -Infinity,
+ value, computed;
+ if (iteratee == null && obj != null) {
+ obj = isArrayLike(obj) ? obj : _.values(obj);
+ for (var i = 0, length = obj.length; i < length; i++) {
+ value = obj[i];
+ if (value > result) {
+ result = value;
+ }
+ }
+ } else {
+ iteratee = cb(iteratee, context);
+ _.each(obj, function(value, index, list) {
+ computed = iteratee(value, index, list);
+ if (computed > lastComputed || computed === -Infinity && result === -Infinity) {
+ result = value;
+ lastComputed = computed;
+ }
+ });
}
- return low;
+ return result;
};
@@ -845,15 +791,32 @@ an object should be inserted so as to maintain order. Uses binary search.
- Safely create a real, live array from anything iterable.
+ Return the minimum element (or element-based computation).
_.toArray = function(obj) {
- if (!obj) return [];
- if (_.isArray(obj)) return slice.call(obj);
- if (obj.length === +obj.length) return _.map(obj, _.identity);
- return _.values(obj);
+ _.min = function(obj, iteratee, context) {
+ var result = Infinity, lastComputed = Infinity,
+ value, computed;
+ if (iteratee == null && obj != null) {
+ obj = isArrayLike(obj) ? obj : _.values(obj);
+ for (var i = 0, length = obj.length; i < length; i++) {
+ value = obj[i];
+ if (value < result) {
+ result = value;
+ }
+ }
+ } else {
+ iteratee = cb(iteratee, context);
+ _.each(obj, function(value, index, list) {
+ computed = iteratee(value, index, list);
+ if (computed < lastComputed || computed === Infinity && result === Infinity) {
+ result = value;
+ lastComputed = computed;
+ }
+ });
+ }
+ return result;
};
@@ -865,13 +828,21 @@ an object should be inserted so as to maintain order. Uses binary search.
- Return the number of elements in an object.
+ Shuffle a collection, using the modern version of the
+Fisher-Yates shuffle.
_.size = function(obj) {
- if (obj == null) return 0;
- return (obj.length === +obj.length) ? obj.length : _.keys(obj).length;
+ _.shuffle = function(obj) {
+ var set = isArrayLike(obj) ? obj : _.values(obj);
+ var length = set.length;
+ var shuffled = Array(length);
+ for (var index = 0, rand; index < length; index++) {
+ rand = _.random(0, index);
+ if (rand !== index) shuffled[index] = shuffled[rand];
+ shuffled[rand] = set[index];
+ }
+ return shuffled;
};
@@ -880,13 +851,23 @@ an object should be inserted so as to maintain order. Uses binary search.
Sample n random values from a collection.
+If n is not specified, returns a single random element.
+The internal guard argument allows it to work with map.
_.sample = function(obj, n, guard) {
+ if (n == null || guard) {
+ if (!isArrayLike(obj)) obj = _.values(obj);
+ return obj[_.random(obj.length - 1)];
+ }
+ return _.shuffle(obj).slice(0, Math.max(0, n));
+ };Get the first element of an array. Passing n will return the first N
-values in the array. Aliased as head and take. The guard check
-allows it to work with _.map.
Sort the object’s values by a criterion produced by an iteratee.
_.first = _.head = _.take = function(array, n, guard) {
- if (array == null) return void 0;
- return (n == null) || guard ? array[0] : slice.call(array, 0, n);
+ _.sortBy = function(obj, iteratee, context) {
+ iteratee = cb(iteratee, context);
+ return _.pluck(_.map(obj, function(value, index, list) {
+ return {
+ value: value,
+ index: index,
+ criteria: iteratee(value, index, list)
+ };
+ }).sort(function(left, right) {
+ var a = left.criteria;
+ var b = right.criteria;
+ if (a !== b) {
+ if (a > b || a === void 0) return 1;
+ if (a < b || b === void 0) return -1;
+ }
+ return left.index - right.index;
+ }), 'value');
};
@@ -916,15 +909,20 @@ allows it to work with _.map.
- Returns everything but the last entry of the array. Especially useful on
-the arguments object. Passing n will return all the values in
-the array, excluding the last N. The guard check allows it to work with
-_.map.
+ An internal function used for aggregate “group by” operations.
_.initial = function(array, n, guard) {
- return slice.call(array, 0, array.length - ((n == null) || guard ? 1 : n));
+ var group = function(behavior) {
+ return function(obj, iteratee, context) {
+ var result = {};
+ iteratee = cb(iteratee, context);
+ _.each(obj, function(value, index) {
+ var key = iteratee(value, index, obj);
+ behavior(result, value, key);
+ });
+ return result;
+ };
};
@@ -936,19 +934,14 @@ the array, excluding the last N. The guard check allows it to w
- Get the last element of an array. Passing n will return the last N
-values in the array. The guard check allows it to work with _.map.
+ Groups the object’s values by a criterion. Pass either a string attribute
+to group by, or a function that returns the criterion.
_.last = function(array, n, guard) {
- if (array == null) return void 0;
- if ((n == null) || guard) {
- return array[array.length - 1];
- } else {
- return slice.call(array, Math.max(array.length - n, 0));
- }
- }; _.groupBy = group(function(result, value, key) {
+ if (_.has(result, key)) result[key].push(value); else result[key] = [value];
+ });Returns everything but the first entry of the array. Aliased as tail and drop.
-Especially useful on the arguments object. Passing an n will return
-the rest N values in the array. The guard
-check allows it to work with _.map.
Indexes the object’s values by a criterion, similar to groupBy, but for
+when you know that your index values will be unique.
_.rest = _.tail = _.drop = function(array, n, guard) {
- return slice.call(array, (n == null) || guard ? 1 : n);
- }; _.indexBy = group(function(result, value, key) {
+ result[key] = value;
+ });_.map.
- Trim out all falsy values from an array.
+Counts instances of an object that group by a certain criterion. Pass +either a string attribute to count by, or a function that returns the +criterion.
_.compact = function(array) {
- return _.filter(array, _.identity);
- }; _.countBy = group(function(result, value, key) {
+ if (_.has(result, key)) result[key]++; else result[key] = 1;
+ });_.map.
- Internal implementation of a recursive flatten function.
Safely create a real, live array from anything iterable.
var flatten = function(input, shallow, output) {
- if (shallow && _.every(input, _.isArray)) {
- return concat.apply(output, input);
- }
- each(input, function(value) {
- if (_.isArray(value) || _.isArguments(value)) {
- shallow ? push.apply(output, value) : flatten(value, shallow, output);
- } else {
- output.push(value);
- }
- });
- return output;
+ _.toArray = function(obj) {
+ if (!obj) return [];
+ if (_.isArray(obj)) return slice.call(obj);
+ if (isArrayLike(obj)) return _.map(obj, _.identity);
+ return _.values(obj);
};
@@ -1023,12 +1009,13 @@ check allows it to work with _.map.
- Flatten out an array, either recursively (by default), or just one level.
+ Return the number of elements in an object.
_.flatten = function(array, shallow) {
- return flatten(array, shallow, []);
+ _.size = function(obj) {
+ if (obj == null) return 0;
+ return isArrayLike(obj) ? obj.length : _.keys(obj).length;
};
@@ -1040,65 +1027,51 @@ check allows it to work with _.map.
- Return a version of the array that does not contain the specified value(s).
+ Split a collection into two arrays: one whose elements all satisfy the given
+predicate, and one whose elements all do not satisfy the predicate.
_.without = function(array) {
- return _.difference(array, slice.call(arguments, 1));
+ _.partition = function(obj, predicate, context) {
+ predicate = cb(predicate, context);
+ var pass = [], fail = [];
+ _.each(obj, function(value, key, obj) {
+ (predicate(value, key, obj) ? pass : fail).push(value);
+ });
+ return [pass, fail];
};
-
-
+
+
Produce a duplicate-free version of the array. If the array has already
-been sorted, you have the option of using a faster algorithm.
-Aliased as unique.
Trim out all falsy values from an object.
_.uniq = _.unique = function(array, isSorted, iterator, context) {
- if (_.isFunction(isSorted)) {
- context = iterator;
- iterator = isSorted;
- isSorted = false;
- }
- var initial = iterator ? _.map(array, iterator, context) : array;
- var results = [];
- var seen = [];
- each(initial, function(value, index) {
- if (isSorted ? (!index || seen[seen.length - 1] !== value) : !_.contains(seen, value)) {
- seen.push(value);
- results.push(array[index]);
- }
- });
- return results;
+ _.compact = function(obj) {
+ return _.filter(obj, _.identity);
};
+
Produce an array that contains the union: each distinct element from all of -the passed-in arrays.
+ _.union = function() {
- return _.uniq(_.flatten(arguments, true));
- }; _.intersection = function(array) {
- var rest = slice.call(arguments, 1);
- return _.filter(_.uniq(array), function(item) {
- return _.every(rest, function(other) {
- return _.indexOf(other, item) >= 0;
- });
- });
- };Take the difference between one array and a number of other arrays. -Only the elements present in just the first array will remain.
+Get the first element of an array. Passing n will return the first N
+values in the array. Aliased as head and take. The guard check
+allows it to work with _.map.
_.difference = function(array) {
- var rest = concat.apply(ArrayProto, slice.call(arguments, 1));
- return _.filter(array, function(value){ return !_.contains(rest, value); });
+ _.first = _.head = _.take = function(array, n, guard) {
+ if (array == null) return void 0;
+ if (n == null || guard) return array[0];
+ return _.initial(array, array.length - n);
};
@@ -1148,20 +1112,16 @@ Only the elements present in just the first array will remain.
- Zip together multiple lists into a single array -- elements that share
-an index go together.
+ Returns everything but the last entry of the array. Especially useful on
+the arguments object. Passing n will return all the values in
+the array, excluding the last N.
- _.zip = function() {
- var length = _.max(_.pluck(arguments, "length").concat(0));
- var results = new Array(length);
- for (var i = 0; i < length; i++) {
- results[i] = _.pluck(arguments, '' + i);
- }
- return results;
+ _.initial = function(array, n, guard) {
+ return slice.call(array, 0, Math.max(0, array.length - (n == null || guard ? 1 : n)));
};
@@ -1171,25 +1131,17 @@ an index go together.
- Converts lists into objects. Pass either a single array of [key, value]
-pairs, or two parallel arrays of the same length -- one of keys, and one of
-the corresponding values.
+ Get the last element of an array. Passing n will return the last N
+values in the array.
- _.object = function(list, values) {
- if (list == null) return {};
- var result = {};
- for (var i = 0, length = list.length; i < length; i++) {
- if (values) {
- result[list[i]] = values[i];
- } else {
- result[list[i][0]] = list[i][1];
- }
- }
- return result;
+ _.last = function(array, n, guard) {
+ if (array == null) return void 0;
+ if (n == null || guard) return array[array.length - 1];
+ return _.rest(array, Math.max(0, array.length - n));
};
@@ -1199,34 +1151,19 @@ the corresponding values.
- If the browser doesn't supply us with indexOf (I'm looking at you, MSIE),
-we need this function. Return the position of the first occurrence of an
-item in an array, or -1 if the item is not included in the array.
-Delegates to ECMAScript 5's native indexOf if available.
-If the array is large and already in sort order, pass true
-for isSorted to use binary search.
+ Returns everything but the first entry of the array. Aliased as tail and drop.
+Especially useful on the arguments object. Passing an n will return
+the rest N values in the array.
- _.indexOf = function(array, item, isSorted) {
- if (array == null) return -1;
- var i = 0, length = array.length;
- if (isSorted) {
- if (typeof isSorted == 'number') {
- i = (isSorted < 0 ? Math.max(0, length + isSorted) : isSorted);
- } else {
- i = _.sortedIndex(array, item);
- return array[i] === item ? i : -1;
- }
- }
- if (nativeIndexOf && array.indexOf === nativeIndexOf) return array.indexOf(item, isSorted);
- for (; i < length; i++) if (array[i] === item) return i;
- return -1;
+ _.rest = _.tail = _.drop = function(array, n, guard) {
+ return slice.call(array, n == null || guard ? 1 : n);
};
-
+
@@ -1235,20 +1172,15 @@ for isSorted to use binary search.
- Delegates to ECMAScript 5's native lastIndexOf if available.
+ Internal implementation of a recursive flatten function.
- _.lastIndexOf = function(array, item, from) {
- if (array == null) return -1;
- var hasIndex = from != null;
- if (nativeLastIndexOf && array.lastIndexOf === nativeLastIndexOf) {
- return hasIndex ? array.lastIndexOf(item, from) : array.lastIndexOf(item);
- }
- var i = (hasIndex ? from : array.length);
- while (i--) if (array[i] === item) return i;
- return -1;
- };
+ var flatten = function(input, shallow, strict, startIndex) {
+ var output = [], idx = 0;
+ for (var i = startIndex || 0, length = getLength(input); i < length; i++) {
+ var value = input[i];
+ if (isArrayLike(value) && (_.isArray(value) || _.isArguments(value))) {
@@ -1259,29 +1191,21 @@ for isSorted to use binary search.
- Generate an integer Array containing an arithmetic progression. A port of
-the native Python range() function. See
-the Python documentation.
+ flatten current level of array or arguments object
- _.range = function(start, stop, step) {
- if (arguments.length <= 1) {
- stop = start || 0;
- start = 0;
+ if (!shallow) value = flatten(value, shallow, strict);
+ var j = 0, len = value.length;
+ output.length += len;
+ while (j < len) {
+ output[idx++] = value[j++];
+ }
+ } else if (!strict) {
+ output[idx++] = value;
+ }
}
- step = arguments[2] || 1;
-
- var length = Math.max(Math.ceil((stop - start) / step), 0);
- var idx = 0;
- var range = new Array(length);
-
- while(idx < length) {
- range[idx++] = start;
- start += step;
- }
-
- return range;
+ return output;
};
@@ -1290,13 +1214,17 @@ the native Python range() function. See
-
+
- Function (ahem) Functions
+ Flatten out an array, either recursively (by default), or just one level.
+ _.flatten = function(array, shallow) {
+ return flatten(array, shallow, false);
+ };
+
@@ -1306,11 +1234,13 @@ the native Python range() function. See
- Reusable constructor function for prototype setting.
+ Return a version of the array that does not contain the specified value(s).
- var ctor = function(){};
+ _.without = function(array) {
+ return _.difference(array, slice.call(arguments, 1));
+ };
@@ -1321,26 +1251,37 @@ the native Python range() function. See
- Create a function bound to a given object (assigning this, and arguments,
-optionally). Delegates to ECMAScript 5's native Function.bind if
-available.
+ Produce a duplicate-free version of the array. If the array has already
+been sorted, you have the option of using a faster algorithm.
+Aliased as unique.
- _.bind = function(func, context) {
- var args, bound;
- if (nativeBind && func.bind === nativeBind) return nativeBind.apply(func, slice.call(arguments, 1));
- if (!_.isFunction(func)) throw new TypeError;
- args = slice.call(arguments, 2);
- return bound = function() {
- if (!(this instanceof bound)) return func.apply(context, args.concat(slice.call(arguments)));
- ctor.prototype = func.prototype;
- var self = new ctor;
- ctor.prototype = null;
- var result = func.apply(self, args.concat(slice.call(arguments)));
- if (Object(result) === result) return result;
- return self;
- };
+ _.uniq = _.unique = function(array, isSorted, iteratee, context) {
+ if (!_.isBoolean(isSorted)) {
+ context = iteratee;
+ iteratee = isSorted;
+ isSorted = false;
+ }
+ if (iteratee != null) iteratee = cb(iteratee, context);
+ var result = [];
+ var seen = [];
+ for (var i = 0, length = getLength(array); i < length; i++) {
+ var value = array[i],
+ computed = iteratee ? iteratee(value, i, array) : value;
+ if (isSorted) {
+ if (!i || seen !== computed) result.push(value);
+ seen = computed;
+ } else if (iteratee) {
+ if (!_.contains(seen, computed)) {
+ seen.push(computed);
+ result.push(value);
+ }
+ } else if (!_.contains(result, value)) {
+ result.push(value);
+ }
+ }
+ return result;
};
@@ -1352,16 +1293,13 @@ available.
- Partially apply a function by creating a version that has had some of its
-arguments pre-filled, without changing its dynamic this context.
+ Produce an array that contains the union: each distinct element from all of
+the passed-in arrays.
- _.partial = function(func) {
- var args = slice.call(arguments, 1);
- return function() {
- return func.apply(this, args.concat(slice.call(arguments)));
- };
+ _.union = function() {
+ return _.uniq(flatten(arguments, true, true));
};
@@ -1373,16 +1311,23 @@ arguments pre-filled, without changing its dynamic this context.
¶
- Bind all of an object's methods to that object. Useful for ensuring that
-all callbacks defined on an object belong to it.
+ Produce an array that contains every item shared between all the
+passed-in arrays.
- _.bindAll = function(obj) {
- var funcs = slice.call(arguments, 1);
- if (funcs.length === 0) throw new Error("bindAll must be passed function names");
- each(funcs, function(f) { obj[f] = _.bind(obj[f], obj); });
- return obj;
+ _.intersection = function(array) {
+ var result = [];
+ var argsLength = arguments.length;
+ for (var i = 0, length = getLength(array); i < length; i++) {
+ var item = array[i];
+ if (_.contains(result, item)) continue;
+ for (var j = 1; j < argsLength; j++) {
+ if (!_.contains(arguments[j], item)) break;
+ }
+ if (j === argsLength) result.push(item);
+ }
+ return result;
};
@@ -1394,17 +1339,16 @@ all callbacks defined on an object belong to it.
- Memoize an expensive function by storing its results.
+ Take the difference between one array and a number of other arrays.
+Only the elements present in just the first array will remain.
- _.memoize = function(func, hasher) {
- var memo = {};
- hasher || (hasher = _.identity);
- return function() {
- var key = hasher.apply(this, arguments);
- return _.has(memo, key) ? memo[key] : (memo[key] = func.apply(this, arguments));
- };
+ _.difference = function(array) {
+ var rest = flatten(arguments, true, true, 1);
+ return _.filter(array, function(value){
+ return !_.contains(rest, value);
+ });
};
@@ -1416,14 +1360,13 @@ all callbacks defined on an object belong to it.
- Delays a function for the given number of milliseconds, and then calls
-it with the arguments supplied.
+ Zip together multiple lists into a single array — elements that share
+an index go together.
- _.delay = function(func, wait) {
- var args = slice.call(arguments, 2);
- return setTimeout(function(){ return func.apply(null, args); }, wait);
+ _.zip = function() {
+ return _.unzip(arguments);
};
@@ -1435,13 +1378,19 @@ it with the arguments supplied.
- Defers a function, scheduling it to run after the current call stack has
-cleared.
+ Complement of _.zip. Unzip accepts an array of arrays and groups
+each array’s elements on shared indices
- _.defer = function(func) {
- return _.delay.apply(_, [func, 1].concat(slice.call(arguments, 1)));
+ _.unzip = function(array) {
+ var length = array && _.max(array, getLength).length || 0;
+ var result = Array(length);
+
+ for (var index = 0; index < length; index++) {
+ result[index] = _.pluck(array, index);
+ }
+ return result;
};
@@ -1453,40 +1402,22 @@ cleared.
- Returns a function, that, when invoked, will only be triggered at most once
-during a given window of time. Normally, the throttled function will run
-as much as it can, without ever going more than once per wait duration;
-but if you'd like to disable the execution on the leading edge, pass
-{leading: false}. To disable execution on the trailing edge, ditto.
+ Converts lists into objects. Pass either a single array of [key, value]
+pairs, or two parallel arrays of the same length — one of keys, and one of
+the corresponding values.
- _.throttle = function(func, wait, options) {
- var context, args, result;
- var timeout = null;
- var previous = 0;
- options || (options = {});
- var later = function() {
- previous = options.leading === false ? 0 : new Date;
- timeout = null;
- result = func.apply(context, args);
- };
- return function() {
- var now = new Date;
- if (!previous && options.leading === false) previous = now;
- var remaining = wait - (now - previous);
- context = this;
- args = arguments;
- if (remaining <= 0) {
- clearTimeout(timeout);
- timeout = null;
- previous = now;
- result = func.apply(context, args);
- } else if (!timeout && options.trailing !== false) {
- timeout = setTimeout(later, remaining);
+ _.object = function(list, values) {
+ var result = {};
+ for (var i = 0, length = getLength(list); i < length; i++) {
+ if (values) {
+ result[list[i]] = values[i];
+ } else {
+ result[list[i][0]] = list[i][1];
}
- return result;
- };
+ }
+ return result;
};
@@ -1498,36 +1429,21 @@ but if you'd like to disable the execution on the leading edge, pass
- Returns a function, that, as long as it continues to be invoked, will not
-be triggered. The function will be called after it stops being called for
-N milliseconds. If immediate is passed, trigger the function on the
-leading edge, instead of the trailing.
+ Generator function to create the findIndex and findLastIndex functions
- _.debounce = function(func, wait, immediate) {
- var timeout, args, context, timestamp, result;
- return function() {
- context = this;
- args = arguments;
- timestamp = new Date();
- var later = function() {
- var last = (new Date()) - timestamp;
- if (last < wait) {
- timeout = setTimeout(later, wait - last);
- } else {
- timeout = null;
- if (!immediate) result = func.apply(context, args);
- }
- };
- var callNow = immediate && !timeout;
- if (!timeout) {
- timeout = setTimeout(later, wait);
+ function createPredicateIndexFinder(dir) {
+ return function(array, predicate, context) {
+ predicate = cb(predicate, context);
+ var length = getLength(array);
+ var index = dir > 0 ? 0 : length - 1;
+ for (; index >= 0 && index < length; index += dir) {
+ if (predicate(array[index], index, array)) return index;
}
- if (callNow) result = func.apply(context, args);
- return result;
+ return -1;
};
- };
+ }
@@ -1538,21 +1454,12 @@ leading edge, instead of the trailing.
- Returns a function that will be executed at most one time, no matter how
-often you call it. Useful for lazy initialization.
+ Returns the first index on an array-like that passes a predicate test
- _.once = function(func) {
- var ran = false, memo;
- return function() {
- if (ran) return memo;
- ran = true;
- memo = func.apply(this, arguments);
- func = null;
- return memo;
- };
- };
+ _.findIndex = createPredicateIndexFinder(1);
+ _.findLastIndex = createPredicateIndexFinder(-1);
@@ -1563,18 +1470,20 @@ often you call it. Useful for lazy initialization.
- Returns the first function passed as an argument to the second,
-allowing you to adjust arguments, run code before and after, and
-conditionally execute the original function.
+ Use a comparator function to figure out the smallest index at which
+an object should be inserted so as to maintain order. Uses binary search.
- _.wrap = function(func, wrapper) {
- return function() {
- var args = [func];
- push.apply(args, arguments);
- return wrapper.apply(this, args);
- };
+ _.sortedIndex = function(array, obj, iteratee, context) {
+ iteratee = cb(iteratee, context, 1);
+ var value = iteratee(obj);
+ var low = 0, high = getLength(array);
+ while (low < high) {
+ var mid = Math.floor((low + high) / 2);
+ if (iteratee(array[mid]) < value) low = mid + 1; else high = mid;
+ }
+ return low;
};
@@ -1586,21 +1495,33 @@ conditionally execute the original function.
- Returns a function that is the composition of a list of functions, each
-consuming the return value of the function that follows.
+ Generator function to create the indexOf and lastIndexOf functions
- _.compose = function() {
- var funcs = arguments;
- return function() {
- var args = arguments;
- for (var i = funcs.length - 1; i >= 0; i--) {
- args = [funcs[i].apply(this, args)];
+ function createIndexFinder(dir, predicateFind, sortedIndex) {
+ return function(array, item, idx) {
+ var i = 0, length = getLength(array);
+ if (typeof idx == 'number') {
+ if (dir > 0) {
+ i = idx >= 0 ? idx : Math.max(idx + length, i);
+ } else {
+ length = idx >= 0 ? Math.min(idx + 1, length) : idx + length + 1;
+ }
+ } else if (sortedIndex && idx && length) {
+ idx = sortedIndex(array, item);
+ return array[idx] === item ? idx : -1;
}
- return args[0];
+ if (item !== item) {
+ idx = predicateFind(slice.call(array, i, length), _.isNaN);
+ return idx >= 0 ? idx + i : -1;
+ }
+ for (idx = dir > 0 ? i : length - 1; idx >= 0 && idx < length; idx += dir) {
+ if (array[idx] === item) return idx;
+ }
+ return -1;
};
- };
+ }
@@ -1611,17 +1532,15 @@ consuming the return value of the function that follows.
- Returns a function that will only be executed after being called N times.
+ Return the position of the first occurrence of an item in an array,
+or -1 if the item is not included in the array.
+If the array is large and already in sort order, pass true
+for isSorted to use binary search.
- _.after = function(times, func) {
- return function() {
- if (--times < 1) {
- return func.apply(this, arguments);
- }
- };
- };
+ _.indexOf = createIndexFinder(1, _.findIndex, _.sortedIndex);
+ _.lastIndexOf = createIndexFinder(-1, _.findLastIndex);
@@ -1629,13 +1548,32 @@ consuming the return value of the function that follows.
-
+
- Object Functions
+ Generate an integer Array containing an arithmetic progression. A port of
+the native Python range() function. See
+the Python documentation.
+ _.range = function(start, stop, step) {
+ if (stop == null) {
+ stop = start || 0;
+ start = 0;
+ }
+ step = step || 1;
+
+ var length = Math.max(Math.ceil((stop - start) / step), 0);
+ var range = Array(length);
+
+ for (var idx = 0; idx < length; idx++, start += step) {
+ range[idx] = start;
+ }
+
+ return range;
+ };
+
@@ -1645,18 +1583,10 @@ consuming the return value of the function that follows.
- Retrieve the names of an object's properties.
-Delegates to ECMAScript 5's native Object.keys
+ Function (ahem) Functions
- _.keys = nativeKeys || function(obj) {
- if (obj !== Object(obj)) throw new TypeError('Invalid object');
- var keys = [];
- for (var key in obj) if (_.has(obj, key)) keys.push(key);
- return keys;
- };
-
@@ -1666,20 +1596,9 @@ Delegates to ECMAScript 5's native Object.keys
- Retrieve the values of an object's properties.
-
+
- _.values = function(obj) {
- var keys = _.keys(obj);
- var length = keys.length;
- var values = new Array(length);
- for (var i = 0; i < length; i++) {
- values[i] = obj[keys[i]];
- }
- return values;
- };
-
@@ -1689,18 +1608,17 @@ Delegates to ECMAScript 5's native Object.keys
- Convert an object into a list of [key, value] pairs.
+ Determines whether to execute a function as a constructor
+or a normal function with the provided arguments
- _.pairs = function(obj) {
- var keys = _.keys(obj);
- var length = keys.length;
- var pairs = new Array(length);
- for (var i = 0; i < length; i++) {
- pairs[i] = [keys[i], obj[keys[i]]];
- }
- return pairs;
+ var executeBound = function(sourceFunc, boundFunc, context, callingContext, args) {
+ if (!(callingContext instanceof boundFunc)) return sourceFunc.apply(context, args);
+ var self = baseCreate(sourceFunc.prototype);
+ var result = sourceFunc.apply(self, args);
+ if (_.isObject(result)) return result;
+ return self;
};
@@ -1712,17 +1630,20 @@ Delegates to ECMAScript 5's native Object.keys
- Invert the keys and values of an object. The values must be serializable.
+ Create a function bound to a given object (assigning this, and arguments,
+optionally). Delegates to ECMAScript 5‘s native Function.bind if
+available.
- _.invert = function(obj) {
- var result = {};
- var keys = _.keys(obj);
- for (var i = 0, length = keys.length; i < length; i++) {
- result[obj[keys[i]]] = keys[i];
- }
- return result;
+ _.bind = function(func, context) {
+ if (nativeBind && func.bind === nativeBind) return nativeBind.apply(func, slice.call(arguments, 1));
+ if (!_.isFunction(func)) throw new TypeError('Bind must be called on a function');
+ var args = slice.call(arguments, 2);
+ var bound = function() {
+ return executeBound(func, bound, context, this, args.concat(slice.call(arguments)));
+ };
+ return bound;
};
@@ -1734,17 +1655,24 @@ Delegates to ECMAScript 5's native Object.keys
- Return a sorted list of the function names available on the object.
-Aliased as methods
+ Partially apply a function by creating a version that has had some of its
+arguments pre-filled, without changing its dynamic this context. _ acts
+as a placeholder, allowing any combination of arguments to be pre-filled.
- _.functions = _.methods = function(obj) {
- var names = [];
- for (var key in obj) {
- if (_.isFunction(obj[key])) names.push(key);
- }
- return names.sort();
+ _.partial = function(func) {
+ var boundArgs = slice.call(arguments, 1);
+ var bound = function() {
+ var position = 0, length = boundArgs.length;
+ var args = Array(length);
+ for (var i = 0; i < length; i++) {
+ args[i] = boundArgs[i] === _ ? arguments[position++] : boundArgs[i];
+ }
+ while (position < arguments.length) args.push(arguments[position++]);
+ return executeBound(func, bound, this, this, args);
+ };
+ return bound;
};
@@ -1756,19 +1684,20 @@ Aliased as methods
- Extend a given object with all the properties in passed-in object(s).
+ Bind a number of an object’s methods to that object. Remaining arguments
+are the method names to be bound. Useful for ensuring that all callbacks
+defined on an object belong to it.
- _.extend = function(obj) {
- each(slice.call(arguments, 1), function(source) {
- if (source) {
- for (var prop in source) {
- obj[prop] = source[prop];
- }
- }
- });
- return obj;
+ _.bindAll = function(obj) {
+ var i, length = arguments.length, key;
+ if (length <= 1) throw new Error('bindAll must be passed function names');
+ for (i = 1; i < length; i++) {
+ key = arguments[i];
+ obj[key] = _.bind(obj[key], obj);
+ }
+ return obj;
};
@@ -1780,17 +1709,19 @@ Aliased as methods
- Return a copy of the object only containing the whitelisted properties.
+ Memoize an expensive function by storing its results.
- _.pick = function(obj) {
- var copy = {};
- var keys = concat.apply(ArrayProto, slice.call(arguments, 1));
- each(keys, function(key) {
- if (key in obj) copy[key] = obj[key];
- });
- return copy;
+ _.memoize = function(func, hasher) {
+ var memoize = function(key) {
+ var cache = memoize.cache;
+ var address = '' + (hasher ? hasher.apply(this, arguments) : key);
+ if (!_.has(cache, address)) cache[address] = func.apply(this, arguments);
+ return cache[address];
+ };
+ memoize.cache = {};
+ return memoize;
};
@@ -1802,17 +1733,16 @@ Aliased as methods
- Return a copy of the object without the blacklisted properties.
+ Delays a function for the given number of milliseconds, and then calls
+it with the arguments supplied.
- _.omit = function(obj) {
- var copy = {};
- var keys = concat.apply(ArrayProto, slice.call(arguments, 1));
- for (var key in obj) {
- if (!_.contains(keys, key)) copy[key] = obj[key];
- }
- return copy;
+ _.delay = function(func, wait) {
+ var args = slice.call(arguments, 2);
+ return setTimeout(function(){
+ return func.apply(null, args);
+ }, wait);
};
@@ -1824,20 +1754,12 @@ Aliased as methods
- Fill in a given object with default properties.
+ Defers a function, scheduling it to run after the current call stack has
+cleared.
- _.defaults = function(obj) {
- each(slice.call(arguments, 1), function(source) {
- if (source) {
- for (var prop in source) {
- if (obj[prop] === void 0) obj[prop] = source[prop];
- }
- }
- });
- return obj;
- };
+ _.defer = _.partial(_.delay, _, 1);
@@ -1848,13 +1770,44 @@ Aliased as methods
- Create a (shallow-cloned) duplicate of an object.
+ Returns a function, that, when invoked, will only be triggered at most once
+during a given window of time. Normally, the throttled function will run
+as much as it can, without ever going more than once per wait duration;
+but if you’d like to disable the execution on the leading edge, pass
+{leading: false}. To disable execution on the trailing edge, ditto.
- _.clone = function(obj) {
- if (!_.isObject(obj)) return obj;
- return _.isArray(obj) ? obj.slice() : _.extend({}, obj);
+ _.throttle = function(func, wait, options) {
+ var context, args, result;
+ var timeout = null;
+ var previous = 0;
+ if (!options) options = {};
+ var later = function() {
+ previous = options.leading === false ? 0 : _.now();
+ timeout = null;
+ result = func.apply(context, args);
+ if (!timeout) context = args = null;
+ };
+ return function() {
+ var now = _.now();
+ if (!previous && options.leading === false) previous = now;
+ var remaining = wait - (now - previous);
+ context = this;
+ args = arguments;
+ if (remaining <= 0 || remaining > wait) {
+ if (timeout) {
+ clearTimeout(timeout);
+ timeout = null;
+ }
+ previous = now;
+ result = func.apply(context, args);
+ if (!timeout) context = args = null;
+ } else if (!timeout && options.trailing !== false) {
+ timeout = setTimeout(later, remaining);
+ }
+ return result;
+ };
};
@@ -1866,15 +1819,43 @@ Aliased as methods
- Invokes interceptor with the obj, and then returns obj.
-The primary purpose of this method is to "tap into" a method chain, in
-order to perform operations on intermediate results within the chain.
+ Returns a function, that, as long as it continues to be invoked, will not
+be triggered. The function will be called after it stops being called for
+N milliseconds. If immediate is passed, trigger the function on the
+leading edge, instead of the trailing.
- _.tap = function(obj, interceptor) {
- interceptor(obj);
- return obj;
+ _.debounce = function(func, wait, immediate) {
+ var timeout, args, context, timestamp, result;
+
+ var later = function() {
+ var last = _.now() - timestamp;
+
+ if (last < wait && last >= 0) {
+ timeout = setTimeout(later, wait - last);
+ } else {
+ timeout = null;
+ if (!immediate) {
+ result = func.apply(context, args);
+ if (!timeout) context = args = null;
+ }
+ }
+ };
+
+ return function() {
+ context = this;
+ args = arguments;
+ timestamp = _.now();
+ var callNow = immediate && !timeout;
+ if (!timeout) timeout = setTimeout(later, wait);
+ if (callNow) {
+ result = func.apply(context, args);
+ context = args = null;
+ }
+
+ return result;
+ };
};
@@ -1886,11 +1867,15 @@ order to perform operations on intermediate results within the chain.
- Internal recursive comparison function for isEqual.
+ Returns the first function passed as an argument to the second,
+allowing you to adjust arguments, run code before and after, and
+conditionally execute the original function.
- var eq = function(a, b, aStack, bStack) {
+ _.wrap = function(func, wrapper) {
+ return _.partial(wrapper, func);
+ };
@@ -1901,12 +1886,15 @@ order to perform operations on intermediate results within the chain.
- Identical objects are equal. 0 === -0, but they aren't identical.
-See the Harmony egal proposal.
+ Returns a negated version of the passed-in predicate.
- if (a === b) return a !== 0 || 1 / a == 1 / b;
+ _.negate = function(predicate) {
+ return function() {
+ return !predicate.apply(this, arguments);
+ };
+ };
@@ -1917,11 +1905,21 @@ See the Harmony
¶
- A strict comparison is necessary because null == undefined.
+ Returns a function that is the composition of a list of functions, each
+consuming the return value of the function that follows.
- if (a == null || b == null) return a === b;
+ _.compose = function() {
+ var args = arguments;
+ var start = args.length - 1;
+ return function() {
+ var i = start;
+ var result = args[start].apply(this, arguments);
+ while (i--) result = args[i].call(this, result);
+ return result;
+ };
+ };
@@ -1932,12 +1930,17 @@ See the Harmony
¶
- Unwrap any wrapped objects.
+ Returns a function that will only be executed on and after the Nth call.
- if (a instanceof _) a = a._wrapped;
- if (b instanceof _) b = b._wrapped;
+ _.after = function(times, func) {
+ return function() {
+ if (--times < 1) {
+ return func.apply(this, arguments);
+ }
+ };
+ };
@@ -1948,13 +1951,20 @@ See the Harmony
¶
- Compare [[Class]] names.
+ Returns a function that will only be executed up to (but not including) the Nth call.
- var className = toString.call(a);
- if (className != toString.call(b)) return false;
- switch (className) {
+ _.before = function(times, func) {
+ var memo;
+ return function() {
+ if (--times > 0) {
+ memo = func.apply(this, arguments);
+ }
+ if (times <= 1) func = null;
+ return memo;
+ };
+ };
@@ -1965,11 +1975,12 @@ See the Harmony
¶
- Strings, numbers, dates, and booleans are compared by value.
+ Returns a function that will be executed at most one time, no matter how
+often you call it. Useful for lazy initialization.
- case '[object String]':
+ _.once = _.partial(_.before, 2);
@@ -1980,14 +1991,10 @@ See the Harmony
¶
- Primitives and their corresponding object wrappers are equivalent; thus, "5" is
-equivalent to new String("5").
+ Object Functions
- return a == String(b);
- case '[object Number]':
-
@@ -1997,15 +2004,9 @@ equivalent to new String("5").
- NaNs are equivalent, but non-reflexive. An egal comparison is performed for
-other numeric values.
-
+
- return a != +a ? b != +b : (a == 0 ? 1 / a == 1 / b : a == +b);
- case '[object Date]':
- case '[object Boolean]':
-
@@ -2015,13 +2016,18 @@ other numeric values.
- Coerce dates and booleans to numeric primitive values. Dates are compared by their
-millisecond representations. Note that invalid dates with millisecond representations
-of NaN are not equivalent.
+ Keys in IE < 9 that won’t be iterated by for key in ... and thus missed.
- return +a == +b;
+ var hasEnumBug = !{toString: null}.propertyIsEnumerable('toString');
+ var nonEnumerableProps = ['valueOf', 'isPrototypeOf', 'toString',
+ 'propertyIsEnumerable', 'hasOwnProperty', 'toLocaleString'];
+
+ function collectNonEnumProps(obj, keys) {
+ var nonEnumIdx = nonEnumerableProps.length;
+ var constructor = obj.constructor;
+ var proto = (_.isFunction(constructor) && constructor.prototype) || ObjProto;
@@ -2032,17 +2038,20 @@ of NaN are not equivalent.
- RegExps are compared by their source patterns and flags.
+ Constructor is a special case.
- case '[object RegExp]':
- return a.source == b.source &&
- a.global == b.global &&
- a.multiline == b.multiline &&
- a.ignoreCase == b.ignoreCase;
+ var prop = 'constructor';
+ if (_.has(obj, prop) && !_.contains(keys, prop)) keys.push(prop);
+
+ while (nonEnumIdx--) {
+ prop = nonEnumerableProps[nonEnumIdx];
+ if (prop in obj && obj[prop] !== proto[prop] && !_.contains(keys, prop)) {
+ keys.push(prop);
+ }
}
- if (typeof a != 'object' || typeof b != 'object') return false;
+ }
@@ -2053,13 +2062,16 @@ of NaN are not equivalent.
- Assume equality for cyclic structures. The algorithm for detecting cyclic
-structures is adapted from ES 5.1 section 15.12.3, abstract operation JO.
+ Retrieve the names of an object’s own properties.
+Delegates to ECMAScript 5‘s native Object.keys
var length = aStack.length;
- while (length--) { _.keys = function(obj) {
+ if (!_.isObject(obj)) return [];
+ if (nativeKeys) return nativeKeys(obj);
+ var keys = [];
+ for (var key in obj) if (_.has(obj, key)) keys.push(key);JO
¶
Linear search. Performance is inversely proportional to the number of -unique nested structures.
+Ahem, IE < 9.
if (aStack[length] == a) return bStack[length] == b;
- } if (hasEnumBug) collectNonEnumProps(obj, keys);
+ return keys;
+ };Objects with different constructors are not equivalent, but Objects
-from different frames are.
Retrieve all the property names of an object.
var aCtor = a.constructor, bCtor = b.constructor;
- if (aCtor !== bCtor && !(_.isFunction(aCtor) && (aCtor instanceof aCtor) &&
- _.isFunction(bCtor) && (bCtor instanceof bCtor))) {
- return false;
- } _.allKeys = function(obj) {
+ if (!_.isObject(obj)) return [];
+ var keys = [];
+ for (var key in obj) keys.push(key);Add the first object to the stack of traversed objects.
+Ahem, IE < 9.
aStack.push(a);
- bStack.push(b);
- var size = 0, result = true; if (hasEnumBug) collectNonEnumProps(obj, keys);
+ return keys;
+ };Recursively compare objects and arrays.
+Retrieve the values of an object’s properties.
if (className == '[object Array]') { _.values = function(obj) {
+ var keys = _.keys(obj);
+ var length = keys.length;
+ var values = Array(length);
+ for (var i = 0; i < length; i++) {
+ values[i] = obj[keys[i]];
+ }
+ return values;
+ };Compare array lengths to determine if a deep comparison is necessary.
+Returns the results of applying the iteratee to each element of the object +In contrast to _.map it returns an object
size = a.length;
- result = size == b.length;
- if (result) { _.mapObject = function(obj, iteratee, context) {
+ iteratee = cb(iteratee, context);
+ var keys = _.keys(obj),
+ length = keys.length,
+ results = {},
+ currentKey;
+ for (var index = 0; index < length; index++) {
+ currentKey = keys[index];
+ results[currentKey] = iteratee(obj[currentKey], currentKey, obj);
+ }
+ return results;
+ };Deep compare the contents, ignoring non-numeric properties.
+Convert an object into a list of [key, value] pairs.
while (size--) {
- if (!(result = eq(a[size], b[size], aStack, bStack))) break;
- }
- }
- } else { _.pairs = function(obj) {
+ var keys = _.keys(obj);
+ var length = keys.length;
+ var pairs = Array(length);
+ for (var i = 0; i < length; i++) {
+ pairs[i] = [keys[i], obj[keys[i]]];
+ }
+ return pairs;
+ };Deep compare objects.
+Invert the keys and values of an object. The values must be serializable.
for (var key in a) {
- if (_.has(a, key)) { _.invert = function(obj) {
+ var result = {};
+ var keys = _.keys(obj);
+ for (var i = 0, length = keys.length; i < length; i++) {
+ result[obj[keys[i]]] = keys[i];
+ }
+ return result;
+ };Count the expected number of properties.
+Return a sorted list of the function names available on the object.
+Aliased as methods
size++; _.functions = _.methods = function(obj) {
+ var names = [];
+ for (var key in obj) {
+ if (_.isFunction(obj[key])) names.push(key);
+ }
+ return names.sort();
+ };Deep compare each member.
+Extend a given object with all the properties in passed-in object(s).
if (!(result = _.has(b, key) && eq(a[key], b[key], aStack, bStack))) break;
- }
- } _.extend = createAssigner(_.allKeys);Ensure that both objects contain the same number of properties.
+Assigns a given object with all the own properties in the passed-in object(s) +(https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object/assign)
if (result) {
- for (key in b) {
- if (_.has(b, key) && !(size--)) break;
- }
- result = !size;
- }
- } _.extendOwn = _.assign = createAssigner(_.keys);Remove the first object from the stack of traversed objects.
+Returns the first key on an object that passes a predicate test
aStack.pop();
- bStack.pop();
- return result;
+ _.findKey = function(obj, predicate, context) {
+ predicate = cb(predicate, context);
+ var keys = _.keys(obj), key;
+ for (var i = 0, length = keys.length; i < length; i++) {
+ key = keys[i];
+ if (predicate(obj[key], key, obj)) return key;
+ }
};
@@ -2262,12 +2304,27 @@ from different frames are.
- Perform a deep comparison to check if two objects are equal.
+ Return a copy of the object only containing the whitelisted properties.
_.isEqual = function(a, b) {
- return eq(a, b, [], []);
+ _.pick = function(object, oiteratee, context) {
+ var result = {}, obj = object, iteratee, keys;
+ if (obj == null) return result;
+ if (_.isFunction(oiteratee)) {
+ keys = _.allKeys(obj);
+ iteratee = optimizeCb(oiteratee, context);
+ } else {
+ keys = flatten(arguments, false, false, 1);
+ iteratee = function(value, key, obj) { return key in obj; };
+ obj = Object(obj);
+ }
+ for (var i = 0, length = keys.length; i < length; i++) {
+ var key = keys[i];
+ var value = obj[key];
+ if (iteratee(value, key, obj)) result[key] = value;
+ }
+ return result;
};
@@ -2279,16 +2336,20 @@ from different frames are.
- Is a given array, string, or object empty?
-An "empty" object has no enumerable own-properties.
+ Return a copy of the object without the blacklisted properties.
_.isEmpty = function(obj) {
- if (obj == null) return true;
- if (_.isArray(obj) || _.isString(obj)) return obj.length === 0;
- for (var key in obj) if (_.has(obj, key)) return false;
- return true;
+ _.omit = function(obj, iteratee, context) {
+ if (_.isFunction(iteratee)) {
+ iteratee = _.negate(iteratee);
+ } else {
+ var keys = _.map(flatten(arguments, false, false, 1), String);
+ iteratee = function(value, key) {
+ return !_.contains(keys, key);
+ };
+ }
+ return _.pick(obj, iteratee, context);
};
@@ -2300,13 +2361,11 @@ An "empty" object has no enumerable own-properties.
- Is a given value a DOM element?
+ Fill in a given object with default properties.
_.isElement = function(obj) {
- return !!(obj && obj.nodeType === 1);
- }; _.defaults = createAssigner(_.allKeys, true);Is a given value an array? -Delegates to ECMA5's native Array.isArray
+Creates an object that inherits from the given prototype object. +If additional properties are provided then they will be added to the +created object.
_.isArray = nativeIsArray || function(obj) {
- return toString.call(obj) == '[object Array]';
+ _.create = function(prototype, props) {
+ var result = baseCreate(prototype);
+ if (props) _.extendOwn(result, props);
+ return result;
};
@@ -2335,12 +2397,13 @@ Delegates to ECMA5's native Array.isArray
- Is a given variable an object?
+ Create a (shallow-cloned) duplicate of an object.
_.isObject = function(obj) {
- return obj === Object(obj);
+ _.clone = function(obj) {
+ if (!_.isObject(obj)) return obj;
+ return _.isArray(obj) ? obj.slice() : _.extend({}, obj);
};
@@ -2352,15 +2415,16 @@ Delegates to ECMA5's native Array.isArray
- Add some isType methods: isArguments, isFunction, isString, isNumber, isDate, isRegExp.
+ Invokes interceptor with the obj, and then returns obj.
+The primary purpose of this method is to “tap into” a method chain, in
+order to perform operations on intermediate results within the chain.
each(['Arguments', 'Function', 'String', 'Number', 'Date', 'RegExp'], function(name) {
- _['is' + name] = function(obj) {
- return toString.call(obj) == '[object ' + name + ']';
- };
- }); _.tap = function(obj, interceptor) {
+ interceptor(obj);
+ return obj;
+ };Define a fallback version of the method in browsers (ahem, IE), where -there isn't any inspectable "Arguments" type.
+Returns whether an object has a given set of key:value pairs.
if (!_.isArguments(arguments)) {
- _.isArguments = function(obj) {
- return !!(obj && _.has(obj, 'callee'));
- };
- } _.isMatch = function(object, attrs) {
+ var keys = _.keys(attrs), length = keys.length;
+ if (object == null) return !length;
+ var obj = Object(object);
+ for (var i = 0; i < length; i++) {
+ var key = keys[i];
+ if (attrs[key] !== obj[key] || !(key in obj)) return false;
+ }
+ return true;
+ };Optimize isFunction if appropriate.
Internal recursive comparison function for isEqual.
if (typeof (/./) !== 'function') {
- _.isFunction = function(obj) {
- return typeof obj === 'function';
- };
- } var eq = function(a, b, aStack, bStack) {Is a given object a finite number?
+Identical objects are equal. 0 === -0, but they aren’t identical.
+See the Harmony egal proposal.
_.isFinite = function(obj) {
- return isFinite(obj) && !isNaN(parseFloat(obj));
- }; if (a === b) return a !== 0 || 1 / a === 1 / b;Is the given value NaN? (NaN is the only number which does not equal itself).
A strict comparison is necessary because null == undefined.
_.isNaN = function(obj) {
- return _.isNumber(obj) && obj != +obj;
- }; if (a == null || b == null) return a === b;Is a given value a boolean?
+Unwrap any wrapped objects.
_.isBoolean = function(obj) {
- return obj === true || obj === false || toString.call(obj) == '[object Boolean]';
- }; if (a instanceof _) a = a._wrapped;
+ if (b instanceof _) b = b._wrapped;Is a given value equal to null?
+Compare [[Class]] names.
_.isNull = function(obj) {
- return obj === null;
- }; var className = toString.call(a);
+ if (className !== toString.call(b)) return false;
+ switch (className) {Is a given variable undefined?
+Strings, numbers, regular expressions, dates, and booleans are compared by value.
- _.isUndefined = function(obj) {
- return obj === void 0;
- }; case '[object RegExp]':Shortcut function for checking if an object has a given property directly -on itself (in other words, not on a prototype).
+RegExps are coerced to strings for comparison (Note: ‘’ + /a/i === ‘/a/i’)
- _.has = function(obj, key) {
- return hasOwnProperty.call(obj, key);
- }; case '[object String]':Primitives and their corresponding object wrappers are equivalent; thus, "5" is
+equivalent to new String("5").
return '' + a === '' + b;
+ case '[object Number]':Run Underscore.js in noConflict mode, returning the _ variable to its
-previous owner. Returns a reference to the Underscore object.
NaNs are equivalent, but non-reflexive.
+Object(NaN) is equivalent to NaN
_.noConflict = function() {
- root._ = previousUnderscore;
- return this;
- }; if (+a !== +a) return +b !== +b;Keep the identity function around for default iterators.
+An egal comparison is performed for other numeric values.
_.identity = function(value) {
- return value;
- }; return +a === 0 ? 1 / +a === 1 / b : +a === +b;
+ case '[object Date]':
+ case '[object Boolean]':Run a function n times.
+Coerce dates and booleans to numeric primitive values. Dates are compared by their
+millisecond representations. Note that invalid dates with millisecond representations
+of NaN are not equivalent.
_.times = function(n, iterator, context) {
- var accum = Array(Math.max(0, n));
- for (var i = 0; i < n; i++) accum[i] = iterator.call(context, i);
- return accum;
- }; return +a === +b;
+ }
+
+ var areArrays = className === '[object Array]';
+ if (!areArrays) {
+ if (typeof a != 'object' || typeof b != 'object') return false;Return a random integer between min and max (inclusive).
+Objects with different constructors are not equivalent, but Objects or Arrays
+from different frames are.
_.random = function(min, max) {
- if (max == null) {
- max = min;
- min = 0;
- }
- return min + Math.floor(Math.random() * (max - min + 1));
- }; var aCtor = a.constructor, bCtor = b.constructor;
+ if (aCtor !== bCtor && !(_.isFunction(aCtor) && aCtor instanceof aCtor &&
+ _.isFunction(bCtor) && bCtor instanceof bCtor)
+ && ('constructor' in a && 'constructor' in b)) {
+ return false;
+ }
+ }List of HTML entities for escaping.
+Assume equality for cyclic structures. The algorithm for detecting cyclic
+structures is adapted from ES 5.1 section 15.12.3, abstract operation JO.
var entityMap = {
- escape: {
- '&': '&',
- '<': '<',
- '>': '>',
- '"': '"',
- "'": '''
- }
- };
- entityMap.unescape = _.invert(entityMap.escape);Regexes containing the keys and values listed immediately above.
+Initializing stack of traversed objects. +It’s done here since we only need them for objects and arrays comparison.
- var entityRegexes = {
- escape: new RegExp('[' + _.keys(entityMap.escape).join('') + ']', 'g'),
- unescape: new RegExp('(' + _.keys(entityMap.unescape).join('|') + ')', 'g')
- }; aStack = aStack || [];
+ bStack = bStack || [];
+ var length = aStack.length;
+ while (length--) {Functions for escaping and unescaping strings to/from HTML interpolation.
+Linear search. Performance is inversely proportional to the number of +unique nested structures.
- _.each(['escape', 'unescape'], function(method) {
- _[method] = function(string) {
- if (string == null) return '';
- return ('' + string).replace(entityRegexes[method], function(match) {
- return entityMap[method][match];
- });
- };
- }); if (aStack[length] === a) return bStack[length] === b;
+ }If the value of the named property is a function then invoke it with the
-object as context; otherwise, return it.
Add the first object to the stack of traversed objects.
- _.result = function(object, property) {
- if (object == null) return void 0;
- var value = object[property];
- return _.isFunction(value) ? value.call(object) : value;
- }; aStack.push(a);
+ bStack.push(b);Add your own custom functions to the Underscore object.
+Recursively compare objects and arrays.
- _.mixin = function(obj) {
- each(_.functions(obj), function(name) {
- var func = _[name] = obj[name];
- _.prototype[name] = function() {
- var args = [this._wrapped];
- push.apply(args, arguments);
- return result.call(this, func.apply(_, args));
- };
- });
- }; if (areArrays) {Generate a unique integer id (unique within the entire client session). -Useful for temporary DOM ids.
+Compare array lengths to determine if a deep comparison is necessary.
- var idCounter = 0;
- _.uniqueId = function(prefix) {
- var id = ++idCounter + '';
- return prefix ? prefix + id : id;
- }; length = a.length;
+ if (length !== b.length) return false;By default, Underscore uses ERB-style template delimiters, change the -following template settings to use alternative delimiters.
+Deep compare the contents, ignoring non-numeric properties.
- _.templateSettings = {
- evaluate : /<%([\s\S]+?)%>/g,
- interpolate : /<%=([\s\S]+?)%>/g,
- escape : /<%-([\s\S]+?)%>/g
- }; while (length--) {
+ if (!eq(a[length], b[length], aStack, bStack)) return false;
+ }
+ } else {When customizing templateSettings, if you don't want to define an
-interpolation, evaluation or escaping regex, we need one that is
-guaranteed not to match.
Deep compare objects.
- var noMatch = /(.)^/; var keys = _.keys(a), key;
+ length = keys.length;Certain characters need to be escaped so that they can be put into a -string literal.
+Ensure that both objects contain the same number of properties before comparing deep equality.
- var escapes = {
- "'": "'",
- '\\': '\\',
- '\r': 'r',
- '\n': 'n',
- '\t': 't',
- '\u2028': 'u2028',
- '\u2029': 'u2029'
- };
-
- var escaper = /\\|'|\r|\n|\t|\u2028|\u2029/g; if (_.keys(b).length !== length) return false;
+ while (length--) {JavaScript micro-templating, similar to John Resig's implementation. -Underscore templating handles arbitrary delimiters, preserves whitespace, -and correctly escapes quotes within interpolated code.
+Deep compare each member
- _.template = function(text, data, settings) {
- var render;
- settings = _.defaults({}, settings, _.templateSettings); key = keys[length];
+ if (!(_.has(b, key) && eq(a[key], b[key], aStack, bStack))) return false;
+ }
+ }Combine delimiters into one regular expression via alternation.
+Remove the first object from the stack of traversed objects.
- var matcher = new RegExp([
- (settings.escape || noMatch).source,
- (settings.interpolate || noMatch).source,
- (settings.evaluate || noMatch).source
- ].join('|') + '|$', 'g'); aStack.pop();
+ bStack.pop();
+ return true;
+ };Compile the template source, escaping string literals appropriately.
+Perform a deep comparison to check if two objects are equal.
- var index = 0;
- var source = "__p+='";
- text.replace(matcher, function(match, escape, interpolate, evaluate, offset) {
- source += text.slice(index, offset)
- .replace(escaper, function(match) { return '\\' + escapes[match]; });
-
- if (escape) {
- source += "'+\n((__t=(" + escape + "))==null?'':_.escape(__t))+\n'";
- }
- if (interpolate) {
- source += "'+\n((__t=(" + interpolate + "))==null?'':__t)+\n'";
- }
- if (evaluate) {
- source += "';\n" + evaluate + "\n__p+='";
- }
- index = offset + match.length;
- return match;
- });
- source += "';\n"; _.isEqual = function(a, b) {
+ return eq(a, b);
+ };If a variable is not specified, place data values in local scope.
+Is a given array, string, or object empty? +An “empty” object has no enumerable own-properties.
- if (!settings.variable) source = 'with(obj||{}){\n' + source + '}\n';
-
- source = "var __t,__p='',__j=Array.prototype.join," +
- "print=function(){__p+=__j.call(arguments,'');};\n" +
- source + "return __p;\n";
-
- try {
- render = new Function(settings.variable || 'obj', '_', source);
- } catch (e) {
- e.source = source;
- throw e;
- }
-
- if (data) return render(data, _);
- var template = function(data) {
- return render.call(this, data, _);
- }; _.isEmpty = function(obj) {
+ if (obj == null) return true;
+ if (isArrayLike(obj) && (_.isArray(obj) || _.isString(obj) || _.isArguments(obj))) return obj.length === 0;
+ return _.keys(obj).length === 0;
+ };Provide the compiled function source as a convenience for precompilation.
+Is a given value a DOM element?
- template.source = 'function(' + (settings.variable || 'obj') + '){\n' + source + '}';
-
- return template;
+ _.isElement = function(obj) {
+ return !!(obj && obj.nodeType === 1);
};
@@ -2913,12 +2899,13 @@ and correctly escapes quotes within interpolated code.
- Add a "chain" function, which will delegate to the wrapper.
+ Is a given value an array?
+Delegates to ECMA5’s native Array.isArray
_.chain = function(obj) {
- return _(obj).chain();
+ _.isArray = nativeIsArray || function(obj) {
+ return toString.call(obj) === '[object Array]';
};
@@ -2927,13 +2914,18 @@ and correctly escapes quotes within interpolated code.
_.isObject = function(obj) {
+ var type = typeof obj;
+ return type === 'function' || type === 'object' && !!obj;
+ };If Underscore is called as a function, it returns a wrapped object that -can be used OO-style. This wrapper holds altered versions of all the -underscore functions. Wrapped objects may be chained.
-Helper function to continue chaining intermediate results.
+Add some isType methods: isArguments, isFunction, isString, isNumber, isDate, isRegExp, isError.
var result = function(obj) {
- return this._chain ? _(obj).chain() : obj;
- }; _.each(['Arguments', 'Function', 'String', 'Number', 'Date', 'RegExp', 'Error'], function(name) {
+ _['is' + name] = function(obj) {
+ return toString.call(obj) === '[object ' + name + ']';
+ };
+ });Add all of the Underscore functions to the wrapper object.
+Define a fallback version of the method in browsers (ahem, IE < 9), where +there isn’t any inspectable “Arguments” type.
_.mixin(_); if (!_.isArguments(arguments)) {
+ _.isArguments = function(obj) {
+ return _.has(obj, 'callee');
+ };
+ }Add all mutator Array functions to the wrapper.
+Optimize isFunction if appropriate. Work around some typeof bugs in old v8,
+IE 11 (#1621), and in Safari 8 (#1929).
each(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(name) {
- var method = ArrayProto[name];
- _.prototype[name] = function() {
- var obj = this._wrapped;
- method.apply(obj, arguments);
- if ((name == 'shift' || name == 'splice') && obj.length === 0) delete obj[0];
- return result.call(this, obj);
+ if (typeof /./ != 'function' && typeof Int8Array != 'object') {
+ _.isFunction = function(obj) {
+ return typeof obj == 'function' || false;
};
- });
+ }Add all accessor Array functions to the wrapper.
+Is a given object a finite number?
each(['concat', 'join', 'slice'], function(name) {
- var method = ArrayProto[name];
- _.prototype[name] = function() {
- return result.call(this, method.apply(this._wrapped, arguments));
- };
- });
-
- _.extend(_.prototype, { _.isFinite = function(obj) {
+ return isFinite(obj) && !isNaN(parseFloat(obj));
+ };Start chaining a wrapped Underscore object.
+Is the given value NaN? (NaN is the only number which does not equal itself).
chain: function() {
- this._chain = true;
- return this;
- }, _.isNaN = function(obj) {
+ return _.isNumber(obj) && obj !== +obj;
+ };Is a given value a boolean?
+ + + + _.isBoolean = function(obj) {
+ return obj === true || obj === false || toString.call(obj) === '[object Boolean]';
+ };Is a given value equal to null?
+ + _.isNull = function(obj) {
+ return obj === null;
+ };Is a given variable undefined?
+ + _.isUndefined = function(obj) {
+ return obj === void 0;
+ };Shortcut function for checking if an object has a given property directly +on itself (in other words, not on a prototype).
+ + _.has = function(obj, key) {
+ return obj != null && hasOwnProperty.call(obj, key);
+ };Run Underscore.js in noConflict mode, returning the _ variable to its
+previous owner. Returns a reference to the Underscore object.
_.noConflict = function() {
+ root._ = previousUnderscore;
+ return this;
+ };Keep the identity function around for default iteratees.
+ + _.identity = function(value) {
+ return value;
+ };Predicate-generating functions. Often useful outside of Underscore.
+ + _.constant = function(value) {
+ return function() {
+ return value;
+ };
+ };
+
+ _.noop = function(){};
+
+ _.property = property;Generates a function for a given object that returns a given property.
+ + _.propertyOf = function(obj) {
+ return obj == null ? function(){} : function(key) {
+ return obj[key];
+ };
+ };Returns a predicate for checking whether an object has a given set of
+key:value pairs.
_.matcher = _.matches = function(attrs) {
+ attrs = _.extendOwn({}, attrs);
+ return function(obj) {
+ return _.isMatch(obj, attrs);
+ };
+ };Run a function n times.
+ + _.times = function(n, iteratee, context) {
+ var accum = Array(Math.max(0, n));
+ iteratee = optimizeCb(iteratee, context, 1);
+ for (var i = 0; i < n; i++) accum[i] = iteratee(i);
+ return accum;
+ };Return a random integer between min and max (inclusive).
+ + _.random = function(min, max) {
+ if (max == null) {
+ max = min;
+ min = 0;
+ }
+ return min + Math.floor(Math.random() * (max - min + 1));
+ };A (possibly faster) way to get the current timestamp as an integer.
+ + _.now = Date.now || function() {
+ return new Date().getTime();
+ };List of HTML entities for escaping.
+ + var escapeMap = {
+ '&': '&',
+ '<': '<',
+ '>': '>',
+ '"': '"',
+ "'": ''',
+ '`': '`'
+ };
+ var unescapeMap = _.invert(escapeMap);Functions for escaping and unescaping strings to/from HTML interpolation.
+ + var createEscaper = function(map) {
+ var escaper = function(match) {
+ return map[match];
+ };Regexes for identifying a key that needs to be escaped
+ + var source = '(?:' + _.keys(map).join('|') + ')';
+ var testRegexp = RegExp(source);
+ var replaceRegexp = RegExp(source, 'g');
+ return function(string) {
+ string = string == null ? '' : '' + string;
+ return testRegexp.test(string) ? string.replace(replaceRegexp, escaper) : string;
+ };
+ };
+ _.escape = createEscaper(escapeMap);
+ _.unescape = createEscaper(unescapeMap);If the value of the named property is a function then invoke it with the
+object as context; otherwise, return it.
_.result = function(object, property, fallback) {
+ var value = object == null ? void 0 : object[property];
+ if (value === void 0) {
+ value = fallback;
+ }
+ return _.isFunction(value) ? value.call(object) : value;
+ };Generate a unique integer id (unique within the entire client session). +Useful for temporary DOM ids.
+ + var idCounter = 0;
+ _.uniqueId = function(prefix) {
+ var id = ++idCounter + '';
+ return prefix ? prefix + id : id;
+ };By default, Underscore uses ERB-style template delimiters, change the +following template settings to use alternative delimiters.
+ + _.templateSettings = {
+ evaluate : /<%([\s\S]+?)%>/g,
+ interpolate : /<%=([\s\S]+?)%>/g,
+ escape : /<%-([\s\S]+?)%>/g
+ };When customizing templateSettings, if you don’t want to define an
+interpolation, evaluation or escaping regex, we need one that is
+guaranteed not to match.
var noMatch = /(.)^/;Certain characters need to be escaped so that they can be put into a +string literal.
+ + var escapes = {
+ "'": "'",
+ '\\': '\\',
+ '\r': 'r',
+ '\n': 'n',
+ '\u2028': 'u2028',
+ '\u2029': 'u2029'
+ };
+
+ var escaper = /\\|'|\r|\n|\u2028|\u2029/g;
+
+ var escapeChar = function(match) {
+ return '\\' + escapes[match];
+ };JavaScript micro-templating, similar to John Resig’s implementation.
+Underscore templating handles arbitrary delimiters, preserves whitespace,
+and correctly escapes quotes within interpolated code.
+NB: oldSettings only exists for backwards compatibility.
_.template = function(text, settings, oldSettings) {
+ if (!settings && oldSettings) settings = oldSettings;
+ settings = _.defaults({}, settings, _.templateSettings);Combine delimiters into one regular expression via alternation.
+ + var matcher = RegExp([
+ (settings.escape || noMatch).source,
+ (settings.interpolate || noMatch).source,
+ (settings.evaluate || noMatch).source
+ ].join('|') + '|$', 'g');Compile the template source, escaping string literals appropriately.
+ + var index = 0;
+ var source = "__p+='";
+ text.replace(matcher, function(match, escape, interpolate, evaluate, offset) {
+ source += text.slice(index, offset).replace(escaper, escapeChar);
+ index = offset + match.length;
+
+ if (escape) {
+ source += "'+\n((__t=(" + escape + "))==null?'':_.escape(__t))+\n'";
+ } else if (interpolate) {
+ source += "'+\n((__t=(" + interpolate + "))==null?'':__t)+\n'";
+ } else if (evaluate) {
+ source += "';\n" + evaluate + "\n__p+='";
+ }Adobe VMs need the match returned to produce the correct offset.
+ + return match;
+ });
+ source += "';\n";If a variable is not specified, place data values in local scope.
+ + if (!settings.variable) source = 'with(obj||{}){\n' + source + '}\n';
+
+ source = "var __t,__p='',__j=Array.prototype.join," +
+ "print=function(){__p+=__j.call(arguments,'');};\n" +
+ source + 'return __p;\n';
+
+ try {
+ var render = new Function(settings.variable || 'obj', '_', source);
+ } catch (e) {
+ e.source = source;
+ throw e;
+ }
+
+ var template = function(data) {
+ return render.call(this, data, _);
+ };Provide the compiled source as a convenience for precompilation.
+ + var argument = settings.variable || 'obj';
+ template.source = 'function(' + argument + '){\n' + source + '}';
+
+ return template;
+ };Add a “chain” function. Start chaining a wrapped Underscore object.
+ + _.chain = function(obj) {
+ var instance = _(obj);
+ instance._chain = true;
+ return instance;
+ };If Underscore is called as a function, it returns a wrapped object that +can be used OO-style. This wrapper holds altered versions of all the +underscore functions. Wrapped objects may be chained.
+ +Helper function to continue chaining intermediate results.
+ + var result = function(instance, obj) {
+ return instance._chain ? _(obj).chain() : obj;
+ };Add your own custom functions to the Underscore object.
+ + _.mixin = function(obj) {
+ _.each(_.functions(obj), function(name) {
+ var func = _[name] = obj[name];
+ _.prototype[name] = function() {
+ var args = [this._wrapped];
+ push.apply(args, arguments);
+ return result(this, func.apply(_, args));
+ };
+ });
+ };Add all of the Underscore functions to the wrapper object.
+ + _.mixin(_);Add all mutator Array functions to the wrapper.
+ + _.each(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(name) {
+ var method = ArrayProto[name];
+ _.prototype[name] = function() {
+ var obj = this._wrapped;
+ method.apply(obj, arguments);
+ if ((name === 'shift' || name === 'splice') && obj.length === 0) delete obj[0];
+ return result(this, obj);
+ };
+ });Add all accessor Array functions to the wrapper.
+ + _.each(['concat', 'join', 'slice'], function(name) {
+ var method = ArrayProto[name];
+ _.prototype[name] = function() {
+ return result(this, method.apply(this._wrapped, arguments));
+ };
+ });Extracts the result from a wrapped and chained object.
value: function() {
- return this._wrapped;
- }
+ _.prototype.value = function() {
+ return this._wrapped;
+ };
+
+
+
+
+ Provide unwrapping proxy for some methods used in engine operations +such as arithmetic and JSON stringification.
- }); + _.prototype.valueOf = _.prototype.toJSON = _.prototype.value;
-}).call(this);AMD registration happens at the end for compatibility with AMD loaders +that may not enforce next-turn semantics on modules. Even though general +practice for AMD registration is to be anonymous, underscore registers +as a named module because, like jQuery, it is a base library that is +popular enough to be bundled in a third party lib, but not be part of +an AMD load request. Those cases could generate an error when an +anonymous define() is called outside of a loader request.
+ + if (typeof define === 'function' && define.amd) {
+ define('underscore', [], function() {
+ return _;
+ });
+ }
+}.call(this));| ' + platform + ' | |
|---|---|
| Test | Ops/sec |