lodash
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A utility library delivering consistency, customization, performance, & extras.
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JavaScript
/**
* @license
* Lo-Dash 2.4.0 (Custom Build) <http://lodash.com/>
* Build: `lodash underscore exports="amd,commonjs,global,node" -o ./dist/lodash.underscore.js`
* Copyright 2012-2013 The Dojo Foundation <http://dojofoundation.org/>
* Based on Underscore.js 1.5.2 <http://underscorejs.org/LICENSE>
* Copyright 2009-2013 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
* Available under MIT license <http://lodash.com/license>
*/
;(function() {
/** Used as a safe reference for `undefined` in pre ES5 environments */
var undefined;
/** Used to generate unique IDs */
var idCounter = 0;
/** Used internally to indicate various things */
var indicatorObject = {};
/** Used to prefix keys to avoid issues with `__proto__` and properties on `Object.prototype` */
var keyPrefix = +new Date + '';
/** Used to match "interpolate" template delimiters */
var reInterpolate = /<%=([\s\S]+?)%>/g;
/** Used to ensure capturing order of template delimiters */
var reNoMatch = /($^)/;
/** Used to match unescaped characters in compiled string literals */
var reUnescapedString = /['\n\r\t\u2028\u2029\\]/g;
/** `Object#toString` result shortcuts */
var argsClass = '[object Arguments]',
arrayClass = '[object Array]',
boolClass = '[object Boolean]',
dateClass = '[object Date]',
funcClass = '[object Function]',
numberClass = '[object Number]',
objectClass = '[object Object]',
regexpClass = '[object RegExp]',
stringClass = '[object String]';
/** Used to determine if values are of the language type Object */
var objectTypes = {
'boolean': false,
'function': true,
'object': true,
'number': false,
'string': false,
'undefined': false
};
/** Used to escape characters for inclusion in compiled string literals */
var stringEscapes = {
'\\': '\\',
"'": "'",
'\n': 'n',
'\r': 'r',
'\t': 't',
'\u2028': 'u2028',
'\u2029': 'u2029'
};
/** Used as a reference to the global object */
var root = (objectTypes[typeof window] && window) || this;
/** Detect free variable `exports` */
var freeExports = objectTypes[typeof exports] && exports && !exports.nodeType && exports;
/** Detect free variable `module` */
var freeModule = objectTypes[typeof module] && module && !module.nodeType && module;
/** Detect the popular CommonJS extension `module.exports` */
var moduleExports = freeModule && freeModule.exports === freeExports && freeExports;
/** Detect free variable `global` from Node.js or Browserified code and use it as `root` */
var freeGlobal = objectTypes[typeof global] && global;
if (freeGlobal && (freeGlobal.global === freeGlobal || freeGlobal.window === freeGlobal)) {
root = freeGlobal;
}
/*--------------------------------------------------------------------------*/
/**
* The base implementation of `_.indexOf` without support for binary searches
* or `fromIndex` constraints.
*
* @private
* @param {Array} array The array to search.
* @param {*} value The value to search for.
* @param {number} [fromIndex=0] The index to search from.
* @returns {number} Returns the index of the matched value or `-1`.
*/
function baseIndexOf(array, value, fromIndex) {
var index = (fromIndex || 0) - 1,
length = array ? array.length : 0;
while (++index < length) {
if (array[index] === value) {
return index;
}
}
return -1;
}
/**
* Used by `sortBy` to compare transformed `collection` elements, stable sorting
* them in ascending order.
*
* @private
* @param {Object} a The object to compare to `b`.
* @param {Object} b The object to compare to `a`.
* @returns {number} Returns the sort order indicator of `1` or `-1`.
*/
function compareAscending(a, b) {
var ac = a.criteria,
bc = b.criteria,
index = -1,
length = ac.length;
while (++index < length) {
var value = ac[index],
other = bc[index];
if (value !== other) {
if (value > other || typeof value == 'undefined') {
return 1;
}
if (value < other || typeof other == 'undefined') {
return -1;
}
}
}
// Fixes an `Array#sort` bug in the JS engine embedded in Adobe applications
// that causes it, under certain circumstances, to return the same value for
// `a` and `b`. See https://github.com/jashkenas/underscore/pull/1247
//
// This also ensures a stable sort in V8 and other engines.
// See http://code.google.com/p/v8/issues/detail?id=90
return a.index - b.index;
}
/**
* Used by `template` to escape characters for inclusion in compiled
* string literals.
*
* @private
* @param {string} match The matched character to escape.
* @returns {string} Returns the escaped character.
*/
function escapeStringChar(match) {
return '\\' + stringEscapes[match];
}
/**
* Slices the `collection` from the `start` index up to, but not including,
* the `end` index.
*
* Note: This function is used instead of `Array#slice` to support node lists
* in IE < 9 and to ensure dense arrays are returned.
*
* @private
* @param {Array|Object|string} collection The collection to slice.
* @param {number} start The start index.
* @param {number} end The end index.
* @returns {Array} Returns the new array.
*/
function slice(array, start, end) {
start || (start = 0);
if (typeof end == 'undefined') {
end = array ? array.length : 0;
}
var index = -1,
length = end - start || 0,
result = Array(length < 0 ? 0 : length);
while (++index < length) {
result[index] = array[start + index];
}
return result;
}
/*--------------------------------------------------------------------------*/
/**
* Used for `Array` method references.
*
* Normally `Array.prototype` would suffice, however, using an array literal
* avoids issues in Narwhal.
*/
var arrayRef = [];
/** Used for native method references */
var objectProto = Object.prototype;
/** Used to restore the original `_` reference in `noConflict` */
var oldDash = root._;
/** Used to resolve the internal [[Class]] of values */
var toString = objectProto.toString;
/** Used to detect if a method is native */
var reNative = RegExp('^' +
String(toString)
.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')
.replace(/toString| for [^\]]+/g, '.*?') + '$'
);
/** Native method shortcuts */
var ceil = Math.ceil,
floor = Math.floor,
hasOwnProperty = objectProto.hasOwnProperty,
push = arrayRef.push,
propertyIsEnumerable = objectProto.propertyIsEnumerable;
/* Native method shortcuts for methods with the same name as other `lodash` methods */
var nativeCreate = reNative.test(nativeCreate = Object.create) && nativeCreate,
nativeIsArray = reNative.test(nativeIsArray = Array.isArray) && nativeIsArray,
nativeIsFinite = root.isFinite,
nativeIsNaN = root.isNaN,
nativeKeys = reNative.test(nativeKeys = Object.keys) && nativeKeys,
nativeMax = Math.max,
nativeMin = Math.min,
nativeRandom = Math.random;
/*--------------------------------------------------------------------------*/
/**
* Creates a `lodash` object which wraps the given value to enable intuitive
* method chaining.
*
* In addition to Lo-Dash methods, wrappers also have the following `Array` methods:
* `concat`, `join`, `pop`, `push`, `reverse`, `shift`, `slice`, `sort`, `splice`,
* and `unshift`
*
* Chaining is supported in custom builds as long as the `value` method is
* implicitly or explicitly included in the build.
*
* The chainable wrapper functions are:
* `after`, `assign`, `bind`, `bindAll`, `bindKey`, `chain`, `compact`,
* `compose`, `concat`, `countBy`, `create`, `createCallback`, `curry`,
* `debounce`, `defaults`, `defer`, `delay`, `difference`, `filter`, `flatten`,
* `forEach`, `forEachRight`, `forIn`, `forInRight`, `forOwn`, `forOwnRight`,
* `functions`, `groupBy`, `indexBy`, `initial`, `intersection`, `invert`,
* `invoke`, `keys`, `map`, `max`, `memoize`, `merge`, `min`, `object`, `omit`,
* `once`, `pairs`, `partial`, `partialRight`, `pick`, `pluck`, `pull`, `push`,
* `range`, `reject`, `remove`, `rest`, `reverse`, `shuffle`, `slice`, `sort`,
* `sortBy`, `splice`, `tap`, `throttle`, `times`, `toArray`, `transform`,
* `union`, `uniq`, `unshift`, `unzip`, `values`, `where`, `without`, `wrap`,
* and `zip`
*
* The non-chainable wrapper functions are:
* `clone`, `cloneDeep`, `contains`, `escape`, `every`, `find`, `findIndex`,
* `findKey`, `findLast`, `findLastIndex`, `findLastKey`, `has`, `identity`,
* `indexOf`, `isArguments`, `isArray`, `isBoolean`, `isDate`, `isElement`,
* `isEmpty`, `isEqual`, `isFinite`, `isFunction`, `isNaN`, `isNull`, `isNumber`,
* `isObject`, `isPlainObject`, `isRegExp`, `isString`, `isUndefined`, `join`,
* `lastIndexOf`, `mixin`, `noConflict`, `parseInt`, `pop`, `random`, `reduce`,
* `reduceRight`, `result`, `shift`, `size`, `some`, `sortedIndex`, `runInContext`,
* `template`, `unescape`, `uniqueId`, and `value`
*
* The wrapper functions `first` and `last` return wrapped values when `n` is
* provided, otherwise they return unwrapped values.
*
* Explicit chaining can be enabled by using the `_.chain` method.
*
* @name _
* @constructor
* @category Chaining
* @param {*} value The value to wrap in a `lodash` instance.
* @returns {Object} Returns a `lodash` instance.
* @example
*
* var wrapped = _([1, 2, 3]);
*
* // returns an unwrapped value
* wrapped.reduce(function(sum, num) {
* return sum + num;
* });
* // => 6
*
* // returns a wrapped value
* var squares = wrapped.map(function(num) {
* return num * num;
* });
*
* _.isArray(squares);
* // => false
*
* _.isArray(squares.value());
* // => true
*/
function lodash(value) {
return (value instanceof lodash)
? value
: new lodashWrapper(value);
}
/**
* A fast path for creating `lodash` wrapper objects.
*
* @private
* @param {*} value The value to wrap in a `lodash` instance.
* @param {boolean} chainAll A flag to enable chaining for all methods
* @returns {Object} Returns a `lodash` instance.
*/
function lodashWrapper(value, chainAll) {
this.__chain__ = !!chainAll;
this.__wrapped__ = value;
}
// ensure `new lodashWrapper` is an instance of `lodash`
lodashWrapper.prototype = lodash.prototype;
/**
* An object used to flag environments features.
*
* @static
* @memberOf _
* @type Object
*/
var support = {};
(function() {
var object = { '0': 1, 'length': 1 };
/**
* Detect if `Array#shift` and `Array#splice` augment array-like objects correctly.
*
* Firefox < 10, IE compatibility mode, and IE < 9 have buggy Array `shift()`
* and `splice()` functions that fail to remove the last element, `value[0]`,
* of array-like objects even though the `length` property is set to `0`.
* The `shift()` method is buggy in IE 8 compatibility mode, while `splice()`
* is buggy regardless of mode in IE < 9 and buggy in compatibility mode in IE 9.
*
* @memberOf _.support
* @type boolean
*/
support.spliceObjects = (arrayRef.splice.call(object, 0, 1), !object[0]);
}(1));
/**
* By default, the template delimiters used by Lo-Dash are similar to those in
* embedded Ruby (ERB). Change the following template settings to use alternative
* delimiters.
*
* @static
* @memberOf _
* @type Object
*/
lodash.templateSettings = {
/**
* Used to detect `data` property values to be HTML-escaped.
*
* @memberOf _.templateSettings
* @type RegExp
*/
'escape': /<%-([\s\S]+?)%>/g,
/**
* Used to detect code to be evaluated.
*
* @memberOf _.templateSettings
* @type RegExp
*/
'evaluate': /<%([\s\S]+?)%>/g,
/**
* Used to detect `data` property values to inject.
*
* @memberOf _.templateSettings
* @type RegExp
*/
'interpolate': reInterpolate,
/**
* Used to reference the data object in the template text.
*
* @memberOf _.templateSettings
* @type string
*/
'variable': ''
};
/*--------------------------------------------------------------------------*/
/**
* The base implementation of `_.bind` that creates the bound function and
* sets its meta data.
*
* @private
* @param {Array} bindData The bind data array.
* @returns {Function} Returns the new bound function.
*/
function baseBind(bindData) {
var func = bindData[0],
partialArgs = bindData[2],
thisArg = bindData[4];
function bound() {
// `Function#bind` spec
// http://es5.github.io/#x15.3.4.5
if (partialArgs) {
var args = partialArgs.slice();
push.apply(args, arguments);
}
// mimic the constructor's `return` behavior
// http://es5.github.io/#x13.2.2
if (this instanceof bound) {
// ensure `new bound` is an instance of `func`
var thisBinding = baseCreate(func.prototype),
result = func.apply(thisBinding, args || arguments);
return isObject(result) ? result : thisBinding;
}
return func.apply(thisArg, args || arguments);
}
return bound;
}
/**
* The base implementation of `_.create` without support for assigning
* properties to the created object.
*
* @private
* @param {Object} prototype The object to inherit from.
* @returns {Object} Returns the new object.
*/
function baseCreate(prototype, properties) {
return isObject(prototype) ? nativeCreate(prototype) : {};
}
// fallback for browsers without `Object.create`
if (!nativeCreate) {
baseCreate = (function() {
function Object() {}
return function(prototype) {
if (isObject(prototype)) {
Object.prototype = prototype;
var result = new Object;
Object.prototype = null;
}
return result || root.Object();
};
}());
}
/**
* The base implementation of `_.createCallback` without support for creating
* "_.pluck" or "_.where" style callbacks.
*
* @private
* @param {*} [func=identity] The value to convert to a callback.
* @param {*} [thisArg] The `this` binding of the created callback.
* @param {number} [argCount] The number of arguments the callback accepts.
* @returns {Function} Returns a callback function.
*/
function baseCreateCallback(func, thisArg, argCount) {
if (typeof func != 'function') {
return identity;
}
// exit early for no `thisArg` or already bound by `Function#bind`
if (typeof thisArg == 'undefined' || !('prototype' in func)) {
return func;
}
switch (argCount) {
case 1: return function(value) {
return func.call(thisArg, value);
};
case 2: return function(a, b) {
return func.call(thisArg, a, b);
};
case 3: return function(value, index, collection) {
return func.call(thisArg, value, index, collection);
};
case 4: return function(accumulator, value, index, collection) {
return func.call(thisArg, accumulator, value, index, collection);
};
}
return bind(func, thisArg);
}
/**
* The base implementation of `createWrapper` that creates the wrapper and
* sets its meta data.
*
* @private
* @param {Array} bindData The bind data array.
* @returns {Function} Returns the new function.
*/
function baseCreateWrapper(bindData) {
var func = bindData[0],
bitmask = bindData[1],
partialArgs = bindData[2],
partialRightArgs = bindData[3],
thisArg = bindData[4],
arity = bindData[5];
var isBind = bitmask & 1,
isBindKey = bitmask & 2,
isCurry = bitmask & 4,
isCurryBound = bitmask & 8,
key = func;
function bound() {
var thisBinding = isBind ? thisArg : this;
if (partialArgs) {
var args = partialArgs.slice();
push.apply(args, arguments);
}
if (partialRightArgs || isCurry) {
args || (args = slice(arguments));
if (partialRightArgs) {
push.apply(args, partialRightArgs);
}
if (isCurry && args.length < arity) {
bitmask |= 16 & ~32;
return baseCreateWrapper([func, (isCurryBound ? bitmask : bitmask & ~3), args, null, thisArg, arity]);
}
}
args || (args = arguments);
if (isBindKey) {
func = thisBinding[key];
}
if (this instanceof bound) {
thisBinding = baseCreate(func.prototype);
var result = func.apply(thisBinding, args);
return isObject(result) ? result : thisBinding;
}
return func.apply(thisBinding, args);
}
return bound;
}
/**
* The base implementation of `_.difference` that accepts a single array
* of values to exclude.
*
* @private
* @param {Array} array The array to process.
* @param {Array} [values] The array of values to exclude.
* @returns {Array} Returns a new array of filtered values.
*/
function baseDifference(array, values) {
var index = -1,
indexOf = getIndexOf(),
length = array ? array.length : 0,
result = [];
while (++index < length) {
var value = array[index];
if (indexOf(values, value) < 0) {
result.push(value);
}
}
return result;
}
/**
* The base implementation of `_.flatten` without support for callback
* shorthands or `thisArg` binding.
*
* @private
* @param {Array} array The array to flatten.
* @param {boolean} [isShallow=false] A flag to restrict flattening to a single level.
* @param {boolean} [isStrict=false] A flag to restrict flattening to arrays and `arguments` objects.
* @param {number} [fromIndex=0] The index to start from.
* @returns {Array} Returns a new flattened array.
*/
function baseFlatten(array, isShallow, isStrict, fromIndex) {
var index = (fromIndex || 0) - 1,
length = array ? array.length : 0,
result = [];
while (++index < length) {
var value = array[index];
if (value && typeof value == 'object' && typeof value.length == 'number'
&& (isArray(value) || isArguments(value))) {
// recursively flatten arrays (susceptible to call stack limits)
if (!isShallow) {
value = baseFlatten(value, isShallow, isStrict);
}
var valIndex = -1,
valLength = value.length,
resIndex = result.length;
result.length += valLength;
while (++valIndex < valLength) {
result[resIndex++] = value[valIndex];
}
} else if (!isStrict) {
result.push(value);
}
}
return result;
}
/**
* The base implementation of `_.isEqual`, without support for `thisArg` binding,
* that allows partial "_.where" style comparisons.
*
* @private
* @param {*} a The value to compare.
* @param {*} b The other value to compare.
* @param {Function} [callback] The function to customize comparing values.
* @param {Function} [isWhere=false] A flag to indicate performing partial comparisons.
* @param {Array} [stackA=[]] Tracks traversed `a` objects.
* @param {Array} [stackB=[]] Tracks traversed `b` objects.
* @returns {boolean} Returns `true` if the values are equivalent, else `false`.
*/
function baseIsEqual(a, b, stackA, stackB) {
if (a === b) {
return a !== 0 || (1 / a == 1 / b);
}
var type = typeof a,
otherType = typeof b;
if (a === a &&
!(a && objectTypes[type]) &&
!(b && objectTypes[otherType])) {
return false;
}
if (a == null || b == null) {
return a === b;
}
var className = toString.call(a),
otherClass = toString.call(b);
if (className != otherClass) {
return false;
}
switch (className) {
case boolClass:
case dateClass:
return +a == +b;
case numberClass:
return a != +a
? b != +b
: (a == 0 ? (1 / a == 1 / b) : a == +b);
case regexpClass:
case stringClass:
return a == String(b);
}
var isArr = className == arrayClass;
if (!isArr) {
var aWrapped = a instanceof lodash,
bWrapped = b instanceof lodash;
if (aWrapped || bWrapped) {
return baseIsEqual(aWrapped ? a.__wrapped__ : a, bWrapped ? b.__wrapped__ : b, stackA, stackB);
}
if (className != objectClass) {
return false;
}
var ctorA = a.constructor,
ctorB = b.constructor;
if (ctorA != ctorB &&
!(isFunction(ctorA) && ctorA instanceof ctorA && isFunction(ctorB) && ctorB instanceof ctorB) &&
('constructor' in a && 'constructor' in b)
) {
return false;
}
}
stackA || (stackA = []);
stackB || (stackB = []);
var length = stackA.length;
while (length--) {
if (stackA[length] == a) {
return stackB[length] == b;
}
}
var result = true,
size = 0;
stackA.push(a);
stackB.push(b);
if (isArr) {
size = b.length;
result = size == a.length;
if (result) {
while (size--) {
if (!(result = baseIsEqual(a[size], b[size], stackA, stackB))) {
break;
}
}
}
return result;
}
forIn(b, function(value, key, b) {
if (hasOwnProperty.call(b, key)) {
size++;
return !(result = hasOwnProperty.call(a, key) && baseIsEqual(a[key], value, stackA, stackB)) && indicatorObject;
}
});
if (result) {
forIn(a, function(value, key, a) {
if (hasOwnProperty.call(a, key)) {
return !(result = --size > -1) && indicatorObject;
}
});
}
return result;
}
/**
* The base implementation of `_.random` without argument juggling or support
* for returning floating-point numbers.
*
* @private
* @param {number} min The minimum possible value.
* @param {number} max The maximum possible value.
* @returns {number} Returns a random number.
*/
function baseRandom(min, max) {
return min + floor(nativeRandom() * (max - min + 1));
}
/**
* The base implementation of `_.uniq` without support for callback shorthands
* or `thisArg` binding.
*
* @private
* @param {Array} array The array to process.
* @param {boolean} [isSorted=false] A flag to indicate that `array` is sorted.
* @param {Function} [callback] The function called per iteration.
* @returns {Array} Returns a duplicate-value-free array.
*/
function baseUniq(array, isSorted, callback) {
var index = -1,
indexOf = getIndexOf(),
length = array ? array.length : 0,
result = [],
seen = callback ? [] : result;
while (++index < length) {
var value = array[index],
computed = callback ? callback(value, index, array) : value;
if (isSorted
? !index || seen[seen.length - 1] !== computed
: indexOf(seen, computed) < 0
) {
if (callback) {
seen.push(computed);
}
result.push(value);
}
}
return result;
}
/**
* Creates a function that aggregates a collection, creating an object composed
* of keys generated from the results of running each element of the collection
* through a callback. The given `setter` function sets the keys and values
* of the composed object.
*
* @private
* @param {Function} setter The setter function.
* @returns {Function} Returns the new aggregator function.
*/
function createAggregator(setter) {
return function(collection, callback, thisArg) {
var result = {};
callback = createCallback(callback, thisArg, 3);
var index = -1,
length = collection ? collection.length : 0;
if (typeof length == 'number') {
while (++index < length) {
var value = collection[index];
setter(result, value, callback(value, index, collection), collection);
}
} else {
forOwn(collection, function(value, key, collection) {
setter(result, value, callback(value, key, collection), collection);
});
}
return result;
};
}
/**
* Creates a function that, when called, either curries or invokes `func`
* with an optional `this` binding and partially applied arguments.
*
* @private
* @param {Function|string} func The function or method name to reference.
* @param {number} bitmask The bitmask of method flags to compose.
* The bitmask may be composed of the following flags:
* 1 - `_.bind`
* 2 - `_.bindKey`
* 4 - `_.curry`
* 8 - `_.curry` (bound)
* 16 - `_.partial`
* 32 - `_.partialRight`
* @param {Array} [partialArgs] An array of arguments to prepend to those
* provided to the new function.
* @param {Array} [partialRightArgs] An array of arguments to append to those
* provided to the new function.
* @param {*} [thisArg] The `this` binding of `func`.
* @param {number} [arity] The arity of `func`.
* @returns {Function} Returns the new function.
*/
function createWrapper(func, bitmask, partialArgs, partialRightArgs, thisArg, arity) {
var isBind = bitmask & 1,
isBindKey = bitmask & 2,
isCurry = bitmask & 4,
isCurryBound = bitmask & 8,
isPartial = bitmask & 16,
isPartialRight = bitmask & 32;
if (!isBindKey && !isFunction(func)) {
throw new TypeError;
}
if (isPartial && !partialArgs.length) {
bitmask &= ~16;
isPartial = partialArgs = false;
}
if (isPartialRight && !partialRightArgs.length) {
bitmask &= ~32;
isPartialRight = partialRightArgs = false;
}
// fast path for `_.bind`
var creater = (bitmask == 1 || bitmask === 17) ? baseBind : baseCreateWrapper;
return creater([func, bitmask, partialArgs, partialRightArgs, thisArg, arity]);
}
/**
* Used by `escape` to convert characters to HTML entities.
*
* @private
* @param {string} match The matched character to escape.
* @returns {string} Returns the escaped character.
*/
function escapeHtmlChar(match) {
return htmlEscapes[match];
}
/**
* Gets the appropriate "indexOf" function. If the `_.indexOf` method is
* customized, this method returns the custom method, otherwise it returns
* the `baseIndexOf` function.
*
* @private
* @returns {Function} Returns the "indexOf" function.
*/
function getIndexOf() {
var result = (result = lodash.indexOf) === indexOf ? baseIndexOf : result;
return result;
}
/**
* Used by `unescape` to convert HTML entities to characters.
*
* @private
* @param {string} match The matched character to unescape.
* @returns {string} Returns the unescaped character.
*/
function unescapeHtmlChar(match) {
return htmlUnescapes[match];
}
/*--------------------------------------------------------------------------*/
/**
* Checks if `value` is an `arguments` object.
*
* @static
* @memberOf _
* @category Objects
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if the `value` is an `arguments` object, else `false`.
* @example
*
* (function() { return _.isArguments(arguments); })(1, 2, 3);
* // => true
*
* _.isArguments([1, 2, 3]);
* // => false
*/
function isArguments(value) {
return value && typeof value == 'object' && typeof value.length == 'number' &&
toString.call(value) == argsClass || false;
}
// fallback for browsers that can't detect `arguments` objects by [[Class]]
if (!isArguments(arguments)) {
isArguments = function(value) {
return value && typeof value == 'object' && typeof value.length == 'number' &&
hasOwnProperty.call(value, 'callee') && !propertyIsEnumerable.call(value, 'callee') || false;
};
}
/**
* Checks if `value` is an array.
*
* @static
* @memberOf _
* @type Function
* @category Objects
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if the `value` is an array, else `false`.
* @example
*
* (function() { return _.isArray(arguments); })();
* // => false
*
* _.isArray([1, 2, 3]);
* // => true
*/
var isArray = nativeIsArray || function(value) {
return value && typeof value == 'object' && typeof value.length == 'number' &&
toString.call(value) == arrayClass || false;
};
/**
* A fallback implementation of `Object.keys` which produces an array of the
* given object's own enumerable property names.
*
* @private
* @type Function
* @param {Object} object The object to inspect.
* @returns {Array} Returns an array of property names.
*/
var shimKeys = function(object) {
var index, iterable = object, result = [];
if (!iterable) return result;
if (!(objectTypes[typeof object])) return result;
for (index in iterable) {
if (hasOwnProperty.call(iterable, index)) {
result.push(index);
}
}
return result
};
/**
* Creates an array composed of the own enumerable property names of an object.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The object to inspect.
* @returns {Array} Returns an array of property names.
* @example
*
* _.keys({ 'one': 1, 'two': 2, 'three': 3 });
* // => ['one', 'two', 'three'] (property order is not guaranteed across environments)
*/
var keys = !nativeKeys ? shimKeys : function(object) {
if (!isObject(object)) {
return [];
}
return nativeKeys(object);
};
/**
* Used to convert characters to HTML entities:
*
* Though the `>` character is escaped for symmetry, characters like `>` and `/`
* don't require escaping in HTML and have no special meaning unless they're part
* of a tag or an unquoted attribute value.
* http://mathiasbynens.be/notes/ambiguous-ampersands (under "semi-related fun fact")
*/
var htmlEscapes = {
'&': '&',
'<': '<',
'>': '>',
'"': '"',
"'": '''
};
/** Used to convert HTML entities to characters */
var htmlUnescapes = invert(htmlEscapes);
/** Used to match HTML entities and HTML characters */
var reEscapedHtml = RegExp('(' + keys(htmlUnescapes).join('|') + ')', 'g'),
reUnescapedHtml = RegExp('[' + keys(htmlEscapes).join('') + ']', 'g');
/*--------------------------------------------------------------------------*/
/**
* Assigns own enumerable properties of source object(s) to the destination
* object. Subsequent sources will overwrite property assignments of previous
* sources. If a callback is provided it will be executed to produce the
* assigned values. The callback is bound to `thisArg` and invoked with two
* arguments; (objectValue, sourceValue).
*
* @static
* @memberOf _
* @type Function
* @alias extend
* @category Objects
* @param {Object} object The destination object.
* @param {...Object} [source] The source objects.
* @param {Function} [callback] The function to customize assigning values.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {Object} Returns the destination object.
* @example
*
* _.assign({ 'name': 'fred' }, { 'employer': 'slate' });
* // => { 'name': 'fred', 'employer': 'slate' }
*
* var defaults = _.partialRight(_.assign, function(a, b) {
* return typeof a == 'undefined' ? b : a;
* });
*
* var object = { 'name': 'barney' };
* defaults(object, { 'name': 'fred', 'employer': 'slate' });
* // => { 'name': 'barney', 'employer': 'slate' }
*/
function assign(object) {
if (!object) {
return object;
}
for (var argsIndex = 1, argsLength = arguments.length; argsIndex < argsLength; argsIndex++) {
var iterable = arguments[argsIndex];
if (iterable) {
for (var key in iterable) {
object[key] = iterable[key];
}
}
}
return object;
}
/**
* Creates a clone of `value`. If `isDeep` is `true` nested objects will also
* be cloned, otherwise they will be assigned by reference. If a callback
* is provided it will be executed to produce the cloned values. If the
* callback returns `undefined` cloning will be handled by the method instead.
* The callback is bound to `thisArg` and invoked with one argument; (value).
*
* @static
* @memberOf _
* @category Objects
* @param {*} value The value to clone.
* @param {boolean} [isDeep=false] Specify a deep clone.
* @param {Function} [callback] The function to customize cloning values.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {*} Returns the cloned value.
* @example
*
* var characters = [
* { 'name': 'barney', 'age': 36 },
* { 'name': 'fred', 'age': 40 }
* ];
*
* var shallow = _.clone(characters);
* shallow[0] === characters[0];
* // => true
*
* var deep = _.clone(characters, true);
* deep[0] === characters[0];
* // => false
*
* _.mixin({
* 'clone': _.partialRight(_.clone, function(value) {
* return _.isElement(value) ? value.cloneNode(false) : undefined;
* })
* });
*
* var clone = _.clone(document.body);
* clone.childNodes.length;
* // => 0
*/
function clone(value) {
return isObject(value)
? (isArray(value) ? slice(value) : assign({}, value))
: value;
}
/**
* Assigns own enumerable properties of source object(s) to the destination
* object for all destination properties that resolve to `undefined`. Once a
* property is set, additional defaults of the same property will be ignored.
*
* @static
* @memberOf _
* @type Function
* @category Objects
* @param {Object} object The destination object.
* @param {...Object} [source] The source objects.
* @param- {Object} [guard] Allows working with `_.reduce` without using its
* `key` and `object` arguments as sources.
* @returns {Object} Returns the destination object.
* @example
*
* var object = { 'name': 'barney' };
* _.defaults(object, { 'name': 'fred', 'employer': 'slate' });
* // => { 'name': 'barney', 'employer': 'slate' }
*/
function defaults(object) {
if (!object) {
return object;
}
for (var argsIndex = 1, argsLength = arguments.length; argsIndex < argsLength; argsIndex++) {
var iterable = arguments[argsIndex];
if (iterable) {
for (var key in iterable) {
if (typeof object[key] == 'undefined') {
object[key] = iterable[key];
}
}
}
}
return object;
}
/**
* Iterates over own and inherited enumerable properties of an object,
* executing the callback for each property. The callback is bound to `thisArg`
* and invoked with three arguments; (value, key, object). Callbacks may exit
* iteration early by explicitly returning `false`.
*
* @static
* @memberOf _
* @type Function
* @category Objects
* @param {Object} object The object to iterate over.
* @param {Function} [callback=identity] The function called per iteration.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {Object} Returns `object`.
* @example
*
* function Shape() {
* this.x = 0;
* this.y = 0;
* }
*
* Shape.prototype.move = function(x, y) {
* this.x += x;
* this.y += y;
* };
*
* _.forIn(new Shape, function(value, key) {
* console.log(key);
* });
* // => logs 'x', 'y', and 'move' (property order is not guaranteed across environments)
*/
var forIn = function(collection, callback) {
var index, iterable = collection, result = iterable;
if (!iterable) return result;
if (!objectTypes[typeof iterable]) return result;
for (index in iterable) {
if (callback(iterable[index], index, collection) === indicatorObject) return result;
}
return result
};
/**
* Iterates over own enumerable properties of an object, executing the callback
* for each property. The callback is bound to `thisArg` and invoked with three
* arguments; (value, key, object). Callbacks may exit iteration early by
* explicitly returning `false`.
*
* @static
* @memberOf _
* @type Function
* @category Objects
* @param {Object} object The object to iterate over.
* @param {Function} [callback=identity] The function called per iteration.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {Object} Returns `object`.
* @example
*
* _.forOwn({ '0': 'zero', '1': 'one', 'length': 2 }, function(num, key) {
* console.log(key);
* });
* // => logs '0', '1', and 'length' (property order is not guaranteed across environments)
*/
var forOwn = function(collection, callback) {
var index, iterable = collection, result = iterable;
if (!iterable) return result;
if (!objectTypes[typeof iterable]) return result;
for (index in iterable) {
if (hasOwnProperty.call(iterable, index)) {
if (callback(iterable[index], index, collection) === indicatorObject) return result;
}
}
return result
};
/**
* Creates a sorted array of property names of all enumerable properties,
* own and inherited, of `object` that have function values.
*
* @static
* @memberOf _
* @alias methods
* @category Objects
* @param {Object} object The object to inspect.
* @returns {Array} Returns an array of property names that have function values.
* @example
*
* _.functions(_);
* // => ['all', 'any', 'bind', 'bindAll', 'clone', 'compact', 'compose', ...]
*/
function functions(object) {
var result = [];
forIn(object, function(value, key) {
if (isFunction(value)) {
result.push(key);
}
});
return result.sort();
}
/**
* Checks if the specified property name exists as a direct property of `object`,
* instead of an inherited property.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The object to inspect.
* @param {string} key The name of the property to check.
* @returns {boolean} Returns `true` if key is a direct property, else `false`.
* @example
*
* _.has({ 'a': 1, 'b': 2, 'c': 3 }, 'b');
* // => true
*/
function has(object, key) {
return object ? hasOwnProperty.call(object, key) : false;
}
/**
* Creates an object composed of the inverted keys and values of the given object.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The object to invert.
* @returns {Object} Returns the created inverted object.
* @example
*
* _.invert({ 'first': 'fred', 'second': 'barney' });
* // => { 'fred': 'first', 'barney': 'second' }
*/
function invert(object) {
var index = -1,
props = keys(object),
length = props.length,
result = {};
while (++index < length) {
var key = props[index];
result[object[key]] = key;
}
return result;
}
/**
* Checks if `value` is a boolean value.
*
* @static
* @memberOf _
* @category Objects
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if the `value` is a boolean value, else `false`.
* @example
*
* _.isBoolean(null);
* // => false
*/
function isBoolean(value) {
return value === true || value === false ||
value && typeof value == 'object' && toString.call(value) == boolClass || false;
}
/**
* Checks if `value` is a date.
*
* @static
* @memberOf _
* @category Objects
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if the `value` is a date, else `false`.
* @example
*
* _.isDate(new Date);
* // => true
*/
function isDate(value) {
return value && typeof value == 'object' && toString.call(value) == dateClass || false;
}
/**
* Checks if `value` is a DOM element.
*
* @static
* @memberOf _
* @category Objects
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if the `value` is a DOM element, else `false`.
* @example
*
* _.isElement(document.body);
* // => true
*/
function isElement(value) {
return value && value.nodeType === 1 || false;
}
/**
* Checks if `value` is empty. Arrays, strings, or `arguments` objects with a
* length of `0` and objects with no own enumerable properties are considered
* "empty".
*
* @static
* @memberOf _
* @category Objects
* @param {Array|Object|string} value The value to inspect.
* @returns {boolean} Returns `true` if the `value` is empty, else `false`.
* @example
*
* _.isEmpty([1, 2, 3]);
* // => false
*
* _.isEmpty({});
* // => true
*
* _.isEmpty('');
* // => true
*/
function isEmpty(value) {
if (!value) {
return true;
}
if (isArray(value) || isString(value)) {
return !value.length;
}
for (var key in value) {
if (hasOwnProperty.call(value, key)) {
return false;
}
}
return true;
}
/**
* Performs a deep comparison between two values to determine if they are
* equivalent to each other. If a callback is provided it will be executed
* to compare values. If the callback returns `undefined` comparisons will
* be handled by the method instead. The callback is bound to `thisArg` and
* invoked with two arguments; (a, b).
*
* @static
* @memberOf _
* @category Objects
* @param {*} a The value to compare.
* @param {*} b The other value to compare.
* @param {Function} [callback] The function to customize comparing values.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {boolean} Returns `true` if the values are equivalent, else `false`.
* @example
*
* var object = { 'name': 'fred' };
* var copy = { 'name': 'fred' };
*
* object == copy;
* // => false
*
* _.isEqual(object, copy);
* // => true
*
* var words = ['hello', 'goodbye'];
* var otherWords = ['hi', 'goodbye'];
*
* _.isEqual(words, otherWords, function(a, b) {
* var reGreet = /^(?:hello|hi)$/i,
* aGreet = _.isString(a) && reGreet.test(a),
* bGreet = _.isString(b) && reGreet.test(b);
*
* return (aGreet || bGreet) ? (aGreet == bGreet) : undefined;
* });
* // => true
*/
function isEqual(a, b) {
return baseIsEqual(a, b);
}
/**
* Checks if `value` is, or can be coerced to, a finite number.
*
* Note: This is not the same as native `isFinite` which will return true for
* booleans and empty strings. See http://es5.github.io/#x15.1.2.5.
*
* @static
* @memberOf _
* @category Objects
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if the `value` is finite, else `false`.
* @example
*
* _.isFinite(-101);
* // => true
*
* _.isFinite('10');
* // => true
*
* _.isFinite(true);
* // => false
*
* _.isFinite('');
* // => false
*
* _.isFinite(Infinity);
* // => false
*/
function isFinite(value) {
return nativeIsFinite(value) && !nativeIsNaN(parseFloat(value));
}
/**
* Checks if `value` is a function.
*
* @static
* @memberOf _
* @category Objects
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if the `value` is a function, else `false`.
* @example
*
* _.isFunction(_);
* // => true
*/
function isFunction(value) {
return typeof value == 'function';
}
// fallback for older versions of Chrome and Safari
if (isFunction(/x/)) {
isFunction = function(value) {
return typeof value == 'function' && toString.call(value) == funcClass;
};
}
/**
* Checks if `value` is the language type of Object.
* (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
*
* @static
* @memberOf _
* @category Objects
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if the `value` is an object, else `false`.
* @example
*
* _.isObject({});
* // => true
*
* _.isObject([1, 2, 3]);
* // => true
*
* _.isObject(1);
* // => false
*/
function isObject(value) {
// check if the value is the ECMAScript language type of Object
// http://es5.github.io/#x8
// and avoid a V8 bug
// http://code.google.com/p/v8/issues/detail?id=2291
return !!(value && objectTypes[typeof value]);
}
/**
* Checks if `value` is `NaN`.
*
* Note: This is not the same as native `isNaN` which will return `true` for
* `undefined` and other non-numeric values. See http://es5.github.io/#x15.1.2.4.
*
* @static
* @memberOf _
* @category Objects
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if the `value` is `NaN`, else `false`.
* @example
*
* _.isNaN(NaN);
* // => true
*
* _.isNaN(new Number(NaN));
* // => true
*
* isNaN(undefined);
* // => true
*
* _.isNaN(undefined);
* // => false
*/
function isNaN(value) {
// `NaN` as a primitive is the only value that is not equal to itself
// (perform the [[Class]] check first to avoid errors with some host objects in IE)
return isNumber(value) && value != +value;
}
/**
* Checks if `value` is `null`.
*
* @static
* @memberOf _
* @category Objects
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if the `value` is `null`, else `false`.
* @example
*
* _.isNull(null);
* // => true
*
* _.isNull(undefined);
* // => false
*/
function isNull(value) {
return value === null;
}
/**
* Checks if `value` is a number.
*
* Note: `NaN` is considered a number. See http://es5.github.io/#x8.5.
*
* @static
* @memberOf _
* @category Objects
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if the `value` is a number, else `false`.
* @example
*
* _.isNumber(8.4 * 5);
* // => true
*/
function isNumber(value) {
return typeof value == 'number' ||
value && typeof value == 'object' && toString.call(value) == numberClass || false;
}
/**
* Checks if `value` is a regular expression.
*
* @static
* @memberOf _
* @category Objects
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if the `value` is a regular expression, else `false`.
* @example
*
* _.isRegExp(/fred/);
* // => true
*/
function isRegExp(value) {
return value && objectTypes[typeof value] && toString.call(value) == regexpClass || false;
}
/**
* Checks if `value` is a string.
*
* @static
* @memberOf _
* @category Objects
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if the `value` is a string, else `false`.
* @example
*
* _.isString('fred');
* // => true
*/
function isString(value) {
return typeof value == 'string' ||
value && typeof value == 'object' && toString.call(value) == stringClass || false;
}
/**
* Checks if `value` is `undefined`.
*
* @static
* @memberOf _
* @category Objects
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if the `value` is `undefined`, else `false`.
* @example
*
* _.isUndefined(void 0);
* // => true
*/
function isUndefined(value) {
return typeof value == 'undefined';
}
/**
* Creates a shallow clone of `object` excluding the specified properties.
* Property names may be specified as individual arguments or as arrays of
* property names. If a callback is provided it will be executed for each
* property of `object` omitting the properties the callback returns truey
* for. The callback is bound to `thisArg` and invoked with three arguments;
* (value, key, object).
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The source object.
* @param {Function|...string|string[]} [callback] The properties to omit or the
* function called per iteration.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {Object} Returns an object without the omitted properties.
* @example
*
* _.omit({ 'name': 'fred', 'age': 40 }, 'age');
* // => { 'name': 'fred' }
*
* _.omit({ 'name': 'fred', 'age': 40 }, function(value) {
* return typeof value == 'number';
* });
* // => { 'name': 'fred' }
*/
function omit(object) {
var props = [];
forIn(object, function(value, key) {
props.push(key);
});
props = baseDifference(props, baseFlatten(arguments, true, false, 1));
var index = -1,
length = props.length,
result = {};
while (++index < length) {
var key = props[index];
result[key] = object[key];
}
return result;
}
/**
* Creates a two dimensional array of an object's key-value pairs,
* i.e. `[[key1, value1], [key2, value2]]`.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The object to inspect.
* @returns {Array} Returns new array of key-value pairs.