/**
* @license
* Lo-Dash 2.4.0 (Custom Build)
* Build: `lodash underscore exports="amd,commonjs,global,node" -o ./dist/lodash.underscore.js`
* Copyright 2012-2013 The Dojo Foundation
* Based on Underscore.js 1.5.2
* Copyright 2009-2013 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
* Available under MIT 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.
* @example
*
* _.pairs({ 'barney': 36, 'fred': 40 });
* // => [['barney', 36], ['fred', 40]] (property order is not guaranteed across environments)
*/
function pairs(object) {
var index = -1,
props = keys(object),
length = props.length,
result = Array(length);
while (++index < length) {
var key = props[index];
result[index] = [key, object[key]];
}
return result;
}
/**
* Creates a shallow clone of `object` composed of the specified properties.
* Property names may be specified as individual arguments or as arrays of
* property names. If a callback is provided it will be executed for each
* property of `object` picking 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 function called per
* iteration or property names to pick, specified as individual property
* names or arrays of property names.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {Object} Returns an object composed of the picked properties.
* @example
*
* _.pick({ 'name': 'fred', '_userid': 'fred1' }, 'name');
* // => { 'name': 'fred' }
*
* _.pick({ 'name': 'fred', '_userid': 'fred1' }, function(value, key) {
* return key.charAt(0) != '_';
* });
* // => { 'name': 'fred' }
*/
function pick(object) {
var index = -1,
props = baseFlatten(arguments, true, false, 1),
length = props.length,
result = {};
while (++index < length) {
var key = props[index];
if (key in object) {
result[key] = object[key];
}
}
return result;
}
/**
* Creates an array composed of the own enumerable property values of `object`.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The object to inspect.
* @returns {Array} Returns an array of property values.
* @example
*
* _.values({ 'one': 1, 'two': 2, 'three': 3 });
* // => [1, 2, 3] (property order is not guaranteed across environments)
*/
function values(object) {
var index = -1,
props = keys(object),
length = props.length,
result = Array(length);
while (++index < length) {
result[index] = object[props[index]];
}
return result;
}
/*--------------------------------------------------------------------------*/
/**
* Checks if a given value is present in a collection using strict equality
* for comparisons, i.e. `===`. If `fromIndex` is negative, it is used as the
* offset from the end of the collection.
*
* @static
* @memberOf _
* @alias include
* @category Collections
* @param {Array|Object|string} collection The collection to iterate over.
* @param {*} target The value to check for.
* @param {number} [fromIndex=0] The index to search from.
* @returns {boolean} Returns `true` if the `target` element is found, else `false`.
* @example
*
* _.contains([1, 2, 3], 1);
* // => true
*
* _.contains([1, 2, 3], 1, 2);
* // => false
*
* _.contains({ 'name': 'fred', 'age': 40 }, 'fred');
* // => true
*
* _.contains('pebbles', 'eb');
* // => true
*/
function contains(collection, target) {
var indexOf = getIndexOf(),
length = collection ? collection.length : 0,
result = false;
if (length && typeof length == 'number') {
result = indexOf(collection, target) > -1;
} else {
forOwn(collection, function(value) {
return (result = value === target) && indicatorObject;
});
}
return result;
}
/**
* Creates an object composed of keys generated from the results of running
* each element of `collection` through the callback. The corresponding value
* of each key is the number of times the key was returned by the callback.
* The callback is bound to `thisArg` and invoked with three arguments;
* (value, index|key, collection).
*
* If a property name is provided for `callback` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `callback` the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Function|Object|string} [callback=identity] The function called
* per iteration. If a property name or object is provided it will be used
* to create a "_.pluck" or "_.where" style callback, respectively.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {Object} Returns the composed aggregate object.
* @example
*
* _.countBy([4.3, 6.1, 6.4], function(num) { return Math.floor(num); });
* // => { '4': 1, '6': 2 }
*
* _.countBy([4.3, 6.1, 6.4], function(num) { return this.floor(num); }, Math);
* // => { '4': 1, '6': 2 }
*
* _.countBy(['one', 'two', 'three'], 'length');
* // => { '3': 2, '5': 1 }
*/
var countBy = createAggregator(function(result, value, key) {
(hasOwnProperty.call(result, key) ? result[key]++ : result[key] = 1);
});
/**
* Checks if the given callback returns truey value for **all** elements of
* a collection. The callback is bound to `thisArg` and invoked with three
* arguments; (value, index|key, collection).
*
* If a property name is provided for `callback` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `callback` the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @alias all
* @category Collections
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Function|Object|string} [callback=identity] The function called
* per iteration. If a property name or object is provided it will be used
* to create a "_.pluck" or "_.where" style callback, respectively.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {boolean} Returns `true` if all elements passed the callback check,
* else `false`.
* @example
*
* _.every([true, 1, null, 'yes']);
* // => false
*
* var characters = [
* { 'name': 'barney', 'age': 36 },
* { 'name': 'fred', 'age': 40 }
* ];
*
* // using "_.pluck" callback shorthand
* _.every(characters, 'age');
* // => true
*
* // using "_.where" callback shorthand
* _.every(characters, { 'age': 36 });
* // => false
*/
function every(collection, callback, thisArg) {
var result = true;
callback = createCallback(callback, thisArg, 3);
var index = -1,
length = collection ? collection.length : 0;
if (typeof length == 'number') {
while (++index < length) {
if (!(result = !!callback(collection[index], index, collection))) {
break;
}
}
} else {
forOwn(collection, function(value, index, collection) {
return !(result = !!callback(value, index, collection)) && indicatorObject;
});
}
return result;
}
/**
* Iterates over elements of a collection, returning an array of all elements
* the callback returns truey for. The callback is bound to `thisArg` and
* invoked with three arguments; (value, index|key, collection).
*
* If a property name is provided for `callback` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `callback` the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @alias select
* @category Collections
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Function|Object|string} [callback=identity] The function called
* per iteration. If a property name or object is provided it will be used
* to create a "_.pluck" or "_.where" style callback, respectively.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {Array} Returns a new array of elements that passed the callback check.
* @example
*
* var evens = _.filter([1, 2, 3, 4, 5, 6], function(num) { return num % 2 == 0; });
* // => [2, 4, 6]
*
* var characters = [
* { 'name': 'barney', 'age': 36, 'blocked': false },
* { 'name': 'fred', 'age': 40, 'blocked': true }
* ];
*
* // using "_.pluck" callback shorthand
* _.filter(characters, 'blocked');
* // => [{ 'name': 'fred', 'age': 40, 'blocked': true }]
*
* // using "_.where" callback shorthand
* _.filter(characters, { 'age': 36 });
* // => [{ 'name': 'barney', 'age': 36, 'blocked': false }]
*/
function filter(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];
if (callback(value, index, collection)) {
result.push(value);
}
}
} else {
forOwn(collection, function(value, index, collection) {
if (callback(value, index, collection)) {
result.push(value);
}
});
}
return result;
}
/**
* Iterates over elements of a collection, returning the first element that
* the callback returns truey for. The callback is bound to `thisArg` and
* invoked with three arguments; (value, index|key, collection).
*
* If a property name is provided for `callback` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `callback` the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @alias detect, findWhere
* @category Collections
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Function|Object|string} [callback=identity] The function called
* per iteration. If a property name or object is provided it will be used
* to create a "_.pluck" or "_.where" style callback, respectively.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {*} Returns the found element, else `undefined`.
* @example
*
* var characters = [
* { 'name': 'barney', 'age': 36, 'blocked': false },
* { 'name': 'fred', 'age': 40, 'blocked': true },
* { 'name': 'pebbles', 'age': 1, 'blocked': false }
* ];
*
* _.find(characters, function(chr) {
* return chr.age < 40;
* });
* // => { 'name': 'barney', 'age': 36, 'blocked': false }
*
* // using "_.where" callback shorthand
* _.find(characters, { 'age': 1 });
* // => { 'name': 'pebbles', 'age': 1, 'blocked': false }
*
* // using "_.pluck" callback shorthand
* _.find(characters, 'blocked');
* // => { 'name': 'fred', 'age': 40, 'blocked': true }
*/
function find(collection, callback, thisArg) {
callback = createCallback(callback, thisArg, 3);
var index = -1,
length = collection ? collection.length : 0;
if (typeof length == 'number') {
while (++index < length) {
var value = collection[index];
if (callback(value, index, collection)) {
return value;
}
}
} else {
var result;
forOwn(collection, function(value, index, collection) {
if (callback(value, index, collection)) {
result = value;
return indicatorObject;
}
});
return result;
}
}
/**
* Examines each element in a `collection`, returning the first that
* has the given properties. When checking `properties`, this method
* performs a deep comparison between values to determine if they are
* equivalent to each other.
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Object} properties The object of property values to filter by.
* @returns {*} Returns the found element, else `undefined`.
* @example
*
* var food = [
* { 'name': 'apple', 'organic': false, 'type': 'fruit' },
* { 'name': 'banana', 'organic': true, 'type': 'fruit' },
* { 'name': 'beet', 'organic': false, 'type': 'vegetable' }
* ];
*
* _.findWhere(food, { 'type': 'vegetable' });
* // => { 'name': 'beet', 'organic': false, 'type': 'vegetable' }
*/
function findWhere(object, properties) {
return where(object, properties, true);
}
/**
* Iterates over elements of a collection, executing the callback for each
* element. The callback is bound to `thisArg` and invoked with three arguments;
* (value, index|key, collection). Callbacks may exit iteration early by
* explicitly returning `false`.
*
* Note: As with other "Collections" methods, objects with a `length` property
* are iterated like arrays. To avoid this behavior `_.forIn` or `_.forOwn`
* may be used for object iteration.
*
* @static
* @memberOf _
* @alias each
* @category Collections
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Function} [callback=identity] The function called per iteration.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {Array|Object|string} Returns `collection`.
* @example
*
* _([1, 2, 3]).forEach(function(num) { console.log(num); }).join(',');
* // => logs each number and returns '1,2,3'
*
* _.forEach({ 'one': 1, 'two': 2, 'three': 3 }, function(num) { console.log(num); });
* // => logs each number and returns the object (property order is not guaranteed across environments)
*/
function forEach(collection, callback, thisArg) {
var index = -1,
length = collection ? collection.length : 0;
callback = callback && typeof thisArg == 'undefined' ? callback : baseCreateCallback(callback, thisArg, 3);
if (typeof length == 'number') {
while (++index < length) {
if (callback(collection[index], index, collection) === indicatorObject) {
break;
}
}
} else {
forOwn(collection, callback);
}
}
/**
* This method is like `_.forEach` except that it iterates over elements
* of a `collection` from right to left.
*
* @static
* @memberOf _
* @alias eachRight
* @category Collections
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Function} [callback=identity] The function called per iteration.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {Array|Object|string} Returns `collection`.
* @example
*
* _([1, 2, 3]).forEachRight(function(num) { console.log(num); }).join(',');
* // => logs each number from right to left and returns '3,2,1'
*/
function forEachRight(collection, callback) {
var length = collection ? collection.length : 0;
if (typeof length == 'number') {
while (length--) {
if (callback(collection[length], length, collection) === false) {
break;
}
}
} else {
var props = keys(collection);
length = props.length;
forOwn(collection, function(value, key, collection) {
key = props ? props[--length] : --length;
return callback(collection[key], key, collection) === false && indicatorObject;
});
}
}
/**
* Creates an object composed of keys generated from the results of running
* each element of a collection through the callback. The corresponding value
* of each key is an array of the elements responsible for generating the key.
* The callback is bound to `thisArg` and invoked with three arguments;
* (value, index|key, collection).
*
* If a property name is provided for `callback` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `callback` the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Function|Object|string} [callback=identity] The function called
* per iteration. If a property name or object is provided it will be used
* to create a "_.pluck" or "_.where" style callback, respectively.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {Object} Returns the composed aggregate object.
* @example
*
* _.groupBy([4.2, 6.1, 6.4], function(num) { return Math.floor(num); });
* // => { '4': [4.2], '6': [6.1, 6.4] }
*
* _.groupBy([4.2, 6.1, 6.4], function(num) { return this.floor(num); }, Math);
* // => { '4': [4.2], '6': [6.1, 6.4] }
*
* // using "_.pluck" callback shorthand
* _.groupBy(['one', 'two', 'three'], 'length');
* // => { '3': ['one', 'two'], '5': ['three'] }
*/
var groupBy = createAggregator(function(result, value, key) {
(hasOwnProperty.call(result, key) ? result[key] : result[key] = []).push(value);
});
/**
* Creates an object composed of keys generated from the results of running
* each element of the collection through the given callback. The corresponding
* value of each key is the last element responsible for generating the key.
* The callback is bound to `thisArg` and invoked with three arguments;
* (value, index|key, collection).
*
* If a property name is provided for `callback` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `callback` the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Function|Object|string} [callback=identity] The function called
* per iteration. If a property name or object is provided it will be used
* to create a "_.pluck" or "_.where" style callback, respectively.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {Object} Returns the composed aggregate object.
* @example
*
* var keys = [
* { 'dir': 'left', 'code': 97 },
* { 'dir': 'right', 'code': 100 }
* ];
*
* _.indexBy(keys, 'dir');
* // => { 'left': { 'dir': 'left', 'code': 97 }, 'right': { 'dir': 'right', 'code': 100 } }
*
* _.indexBy(keys, function(key) { return String.fromCharCode(key.code); });
* // => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } }
*
* _.indexBy(characters, function(key) { this.fromCharCode(key.code); }, String);
* // => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } }
*/
var indexBy = createAggregator(function(result, value, key) {
result[key] = value;
});
/**
* Invokes the method named by `methodName` on each element in the `collection`
* returning an array of the results of each invoked method. Additional arguments
* will be provided to each invoked method. If `methodName` is a function it
* will be invoked for, and `this` bound to, each element in the `collection`.
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Function|string} methodName The name of the method to invoke or
* the function invoked per iteration.
* @param {...*} [arg] Arguments to invoke the method with.
* @returns {Array} Returns a new array of the results of each invoked method.
* @example
*
* _.invoke([[5, 1, 7], [3, 2, 1]], 'sort');
* // => [[1, 5, 7], [1, 2, 3]]
*
* _.invoke([123, 456], String.prototype.split, '');
* // => [['1', '2', '3'], ['4', '5', '6']]
*/
function invoke(collection, methodName) {
var args = slice(arguments, 2),
index = -1,
isFunc = typeof methodName == 'function',
length = collection ? collection.length : 0,
result = Array(typeof length == 'number' ? length : 0);
forEach(collection, function(value) {
result[++index] = (isFunc ? methodName : value[methodName]).apply(value, args);
});
return result;
}
/**
* Creates an array of values by running each element in the collection
* through the callback. The callback is bound to `thisArg` and invoked with
* three arguments; (value, index|key, collection).
*
* If a property name is provided for `callback` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `callback` the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @alias collect
* @category Collections
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Function|Object|string} [callback=identity] The function called
* per iteration. If a property name or object is provided it will be used
* to create a "_.pluck" or "_.where" style callback, respectively.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {Array} Returns a new array of the results of each `callback` execution.
* @example
*
* _.map([1, 2, 3], function(num) { return num * 3; });
* // => [3, 6, 9]
*
* _.map({ 'one': 1, 'two': 2, 'three': 3 }, function(num) { return num * 3; });
* // => [3, 6, 9] (property order is not guaranteed across environments)
*
* var characters = [
* { 'name': 'barney', 'age': 36 },
* { 'name': 'fred', 'age': 40 }
* ];
*
* // using "_.pluck" callback shorthand
* _.map(characters, 'name');
* // => ['barney', 'fred']
*/
function map(collection, callback, thisArg) {
var index = -1,
length = collection ? collection.length : 0;
callback = createCallback(callback, thisArg, 3);
if (typeof length == 'number') {
var result = Array(length);
while (++index < length) {
result[index] = callback(collection[index], index, collection);
}
} else {
result = [];
forOwn(collection, function(value, key, collection) {
result[++index] = callback(value, key, collection);
});
}
return result;
}
/**
* Retrieves the maximum value of a collection. If the collection is empty or
* falsey `-Infinity` is returned. If a callback is provided it will be executed
* for each value in the collection to generate the criterion by which the value
* is ranked. The callback is bound to `thisArg` and invoked with three
* arguments; (value, index, collection).
*
* If a property name is provided for `callback` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `callback` the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Function|Object|string} [callback=identity] The function called
* per iteration. If a property name or object is provided it will be used
* to create a "_.pluck" or "_.where" style callback, respectively.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {*} Returns the maximum value.
* @example
*
* _.max([4, 2, 8, 6]);
* // => 8
*
* var characters = [
* { 'name': 'barney', 'age': 36 },
* { 'name': 'fred', 'age': 40 }
* ];
*
* _.max(characters, function(chr) { return chr.age; });
* // => { 'name': 'fred', 'age': 40 };
*
* // using "_.pluck" callback shorthand
* _.max(characters, 'age');
* // => { 'name': 'fred', 'age': 40 };
*/
function max(collection, callback, thisArg) {
var computed = -Infinity,
result = computed;
// allows working with functions like `_.map` without using
// their `index` argument as a callback
if (typeof callback != 'function' && thisArg && thisArg[callback] === collection) {
callback = null;
}
var index = -1,
length = collection ? collection.length : 0;
if (callback == null && typeof length == 'number') {
while (++index < length) {
var value = collection[index];
if (value > result) {
result = value;
}
}
} else {
callback = createCallback(callback, thisArg, 3);
forEach(collection, function(value, index, collection) {
var current = callback(value, index, collection);
if (current > computed) {
computed = current;
result = value;
}
});
}
return result;
}
/**
* Retrieves the minimum value of a collection. If the collection is empty or
* falsey `Infinity` is returned. If a callback is provided it will be executed
* for each value in the collection to generate the criterion by which the value
* is ranked. The callback is bound to `thisArg` and invoked with three
* arguments; (value, index, collection).
*
* If a property name is provided for `callback` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `callback` the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Function|Object|string} [callback=identity] The function called
* per iteration. If a property name or object is provided it will be used
* to create a "_.pluck" or "_.where" style callback, respectively.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {*} Returns the minimum value.
* @example
*
* _.min([4, 2, 8, 6]);
* // => 2
*
* var characters = [
* { 'name': 'barney', 'age': 36 },
* { 'name': 'fred', 'age': 40 }
* ];
*
* _.min(characters, function(chr) { return chr.age; });
* // => { 'name': 'barney', 'age': 36 };
*
* // using "_.pluck" callback shorthand
* _.min(characters, 'age');
* // => { 'name': 'barney', 'age': 36 };
*/
function min(collection, callback, thisArg) {
var computed = Infinity,
result = computed;
// allows working with functions like `_.map` without using
// their `index` argument as a callback
if (typeof callback != 'function' && thisArg && thisArg[callback] === collection) {
callback = null;
}
var index = -1,
length = collection ? collection.length : 0;
if (callback == null && typeof length == 'number') {
while (++index < length) {
var value = collection[index];
if (value < result) {
result = value;
}
}
} else {
callback = createCallback(callback, thisArg, 3);
forEach(collection, function(value, index, collection) {
var current = callback(value, index, collection);
if (current < computed) {
computed = current;
result = value;
}
});
}
return result;
}
/**
* Retrieves the value of a specified property from all elements in the collection.
*
* @static
* @memberOf _
* @type Function
* @category Collections
* @param {Array|Object|string} collection The collection to iterate over.
* @param {string} property The name of the property to pluck.
* @returns {Array} Returns a new array of property values.
* @example
*
* var characters = [
* { 'name': 'barney', 'age': 36 },
* { 'name': 'fred', 'age': 40 }
* ];
*
* _.pluck(characters, 'name');
* // => ['barney', 'fred']
*/
var pluck = map;
/**
* Reduces a collection to a value which is the accumulated result of running
* each element in the collection through the callback, where each successive
* callback execution consumes the return value of the previous execution. If
* `accumulator` is not provided the first element of the collection will be
* used as the initial `accumulator` value. The callback is bound to `thisArg`
* and invoked with four arguments; (accumulator, value, index|key, collection).
*
* @static
* @memberOf _
* @alias foldl, inject
* @category Collections
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Function} [callback=identity] The function called per iteration.
* @param {*} [accumulator] Initial value of the accumulator.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {*} Returns the accumulated value.
* @example
*
* var sum = _.reduce([1, 2, 3], function(sum, num) {
* return sum + num;
* });
* // => 6
*
* var mapped = _.reduce({ 'a': 1, 'b': 2, 'c': 3 }, function(result, num, key) {
* result[key] = num * 3;
* return result;
* }, {});
* // => { 'a': 3, 'b': 6, 'c': 9 }
*/
function reduce(collection, callback, accumulator, thisArg) {
if (!collection) return accumulator;
var noaccum = arguments.length < 3;
callback = createCallback(callback, thisArg, 4);
var index = -1,
length = collection.length;
if (typeof length == 'number') {
if (noaccum) {
accumulator = collection[++index];
}
while (++index < length) {
accumulator = callback(accumulator, collection[index], index, collection);
}
} else {
forOwn(collection, function(value, index, collection) {
accumulator = noaccum
? (noaccum = false, value)
: callback(accumulator, value, index, collection)
});
}
return accumulator;
}
/**
* This method is like `_.reduce` except that it iterates over elements
* of a `collection` from right to left.
*
* @static
* @memberOf _
* @alias foldr
* @category Collections
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Function} [callback=identity] The function called per iteration.
* @param {*} [accumulator] Initial value of the accumulator.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {*} Returns the accumulated value.
* @example
*
* var list = [[0, 1], [2, 3], [4, 5]];
* var flat = _.reduceRight(list, function(a, b) { return a.concat(b); }, []);
* // => [4, 5, 2, 3, 0, 1]
*/
function reduceRight(collection, callback, accumulator, thisArg) {
var noaccum = arguments.length < 3;
callback = createCallback(callback, thisArg, 4);
forEachRight(collection, function(value, index, collection) {
accumulator = noaccum
? (noaccum = false, value)
: callback(accumulator, value, index, collection);
});
return accumulator;
}
/**
* The opposite of `_.filter` this method returns the elements of a
* collection that the callback does **not** return truey for.
*
* If a property name is provided for `callback` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `callback` the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Function|Object|string} [callback=identity] The function called
* per iteration. If a property name or object is provided it will be used
* to create a "_.pluck" or "_.where" style callback, respectively.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {Array} Returns a new array of elements that failed the callback check.
* @example
*
* var odds = _.reject([1, 2, 3, 4, 5, 6], function(num) { return num % 2 == 0; });
* // => [1, 3, 5]
*
* var characters = [
* { 'name': 'barney', 'age': 36, 'blocked': false },
* { 'name': 'fred', 'age': 40, 'blocked': true }
* ];
*
* // using "_.pluck" callback shorthand
* _.reject(characters, 'blocked');
* // => [{ 'name': 'barney', 'age': 36, 'blocked': false }]
*
* // using "_.where" callback shorthand
* _.reject(characters, { 'age': 36 });
* // => [{ 'name': 'fred', 'age': 40, 'blocked': true }]
*/
function reject(collection, callback, thisArg) {
callback = createCallback(callback, thisArg, 3);
return filter(collection, function(value, index, collection) {
return !callback(value, index, collection);
});
}
/**
* Retrieves a random element or `n` random elements from a collection.
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|string} collection The collection to sample.
* @param {number} [n] The number of elements to sample.
* @param- {Object} [guard] Allows working with functions like `_.map`
* without using their `index` arguments as `n`.
* @returns {Array} Returns the random sample(s) of `collection`.
* @example
*
* _.sample([1, 2, 3, 4]);
* // => 2
*
* _.sample([1, 2, 3, 4], 2);
* // => [3, 1]
*/
function sample(collection, n, guard) {
if (collection && typeof collection.length != 'number') {
collection = values(collection);
}
if (n == null || guard) {
return collection ? collection[baseRandom(0, collection.length - 1)] : undefined;
}
var result = shuffle(collection);
result.length = nativeMin(nativeMax(0, n), result.length);
return result;
}
/**
* Creates an array of shuffled values, using a version of the Fisher-Yates
* shuffle. See http://en.wikipedia.org/wiki/Fisher-Yates_shuffle.
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|string} collection The collection to shuffle.
* @returns {Array} Returns a new shuffled collection.
* @example
*
* _.shuffle([1, 2, 3, 4, 5, 6]);
* // => [4, 1, 6, 3, 5, 2]
*/
function shuffle(collection) {
var index = -1,
length = collection ? collection.length : 0,
result = Array(typeof length == 'number' ? length : 0);
forEach(collection, function(value) {
var rand = baseRandom(0, ++index);
result[index] = result[rand];
result[rand] = value;
});
return result;
}
/**
* Gets the size of the `collection` by returning `collection.length` for arrays
* and array-like objects or the number of own enumerable properties for objects.
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|string} collection The collection to inspect.
* @returns {number} Returns `collection.length` or number of own enumerable properties.
* @example
*
* _.size([1, 2]);
* // => 2
*
* _.size({ 'one': 1, 'two': 2, 'three': 3 });
* // => 3
*
* _.size('pebbles');
* // => 7
*/
function size(collection) {
var length = collection ? collection.length : 0;
return typeof length == 'number' ? length : keys(collection).length;
}
/**
* Checks if the callback returns a truey value for **any** element of a
* collection. The function returns as soon as it finds a passing value and
* does not iterate over the entire collection. The callback is bound to
* `thisArg` and invoked with three arguments; (value, index|key, collection).
*
* If a property name is provided for `callback` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `callback` the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @alias any
* @category Collections
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Function|Object|string} [callback=identity] The function called
* per iteration. If a property name or object is provided it will be used
* to create a "_.pluck" or "_.where" style callback, respectively.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {boolean} Returns `true` if any element passed the callback check,
* else `false`.
* @example
*
* _.some([null, 0, 'yes', false], Boolean);
* // => true
*
* var characters = [
* { 'name': 'barney', 'age': 36, 'blocked': false },
* { 'name': 'fred', 'age': 40, 'blocked': true }
* ];
*
* // using "_.pluck" callback shorthand
* _.some(characters, 'blocked');
* // => true
*
* // using "_.where" callback shorthand
* _.some(characters, { 'age': 1 });
* // => false
*/
function some(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) {
if ((result = callback(collection[index], index, collection))) {
break;
}
}
} else {
forOwn(collection, function(value, index, collection) {
return (result = callback(value, index, collection)) && indicatorObject;
});
}
return !!result;
}
/**
* Creates an array of elements, sorted in ascending order by the results of
* running each element in a collection through the callback. This method
* performs a stable sort, that is, it will preserve the original sort order
* of equal elements. The callback is bound to `thisArg` and invoked with
* three arguments; (value, index|key, collection).
*
* If a property name is provided for `callback` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an array of property names is provided for `callback` the collection
* will be sorted by each property value.
*
* If an object is provided for `callback` the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Array|Function|Object|string} [callback=identity] The function called
* per iteration. If a property name or object is provided it will be used
* to create a "_.pluck" or "_.where" style callback, respectively.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {Array} Returns a new array of sorted elements.
* @example
*
* _.sortBy([1, 2, 3], function(num) { return Math.sin(num); });
* // => [3, 1, 2]
*
* _.sortBy([1, 2, 3], function(num) { return this.sin(num); }, Math);
* // => [3, 1, 2]
*
* var characters = [
* { 'name': 'barney', 'age': 36 },
* { 'name': 'fred', 'age': 40 },
* { 'name': 'barney', 'age': 26 },
* { 'name': 'fred', 'age': 30 }
* ];
*
* // using "_.pluck" callback shorthand
* _.map(_.sortBy(characters, 'age'), _.values);
* // => [['barney', 26], ['fred', 30], ['barney', 36], ['fred', 40]]
*
* // sorting by multiple properties
* _.map(_.sortBy(characters, ['name', 'age']), _.values);
* // = > [['barney', 26], ['barney', 36], ['fred', 30], ['fred', 40]]
*/
function sortBy(collection, callback, thisArg) {
var index = -1,
length = collection ? collection.length : 0,
result = Array(typeof length == 'number' ? length : 0);
callback = createCallback(callback, thisArg, 3);
forEach(collection, function(value, key, collection) {
result[++index] = {
'criteria': [callback(value, key, collection)],
'index': index,
'value': value
};
});
length = result.length;
result.sort(compareAscending);
while (length--) {
result[length] = result[length].value;
}
return result;
}
/**
* Converts the `collection` to an array.
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|string} collection The collection to convert.
* @returns {Array} Returns the new converted array.
* @example
*
* (function() { return _.toArray(arguments).slice(1); })(1, 2, 3, 4);
* // => [2, 3, 4]
*/
function toArray(collection) {
if (isArray(collection)) {
return slice(collection);
}
if (collection && typeof collection.length == 'number') {
return map(collection);
}
return values(collection);
}
/**
* Performs a deep comparison of each element in a `collection` to the given
* `properties` object, returning an array of all elements that have equivalent
* property values.
*
* @static
* @memberOf _
* @type Function
* @category Collections
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Object} props The object of property values to filter by.
* @returns {Array} Returns a new array of elements that have the given properties.
* @example
*
* var characters = [
* { 'name': 'barney', 'age': 36, 'pets': ['hoppy'] },
* { 'name': 'fred', 'age': 40, 'pets': ['baby puss', 'dino'] }
* ];
*
* _.where(characters, { 'age': 36 });
* // => [{ 'name': 'barney', 'age': 36, 'pets': ['hoppy'] }]
*
* _.where(characters, { 'pets': ['dino'] });
* // => [{ 'name': 'fred', 'age': 40, 'pets': ['baby puss', 'dino'] }]
*/
function where(collection, properties, first) {
return (first && isEmpty(properties))
? undefined
: (first ? find : filter)(collection, properties);
}
/*--------------------------------------------------------------------------*/
/**
* Creates an array with all falsey values removed. The values `false`, `null`,
* `0`, `""`, `undefined`, and `NaN` are all falsey.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to compact.
* @returns {Array} Returns a new array of filtered values.
* @example
*
* _.compact([0, 1, false, 2, '', 3]);
* // => [1, 2, 3]
*/
function compact(array) {
var index = -1,
length = array ? array.length : 0,
result = [];
while (++index < length) {
var value = array[index];
if (value) {
result.push(value);
}
}
return result;
}
/**
* Creates an array excluding all values of the provided arrays using strict
* equality for comparisons, i.e. `===`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to process.
* @param {...Array} [values] The arrays of values to exclude.
* @returns {Array} Returns a new array of filtered values.
* @example
*
* _.difference([1, 2, 3, 4, 5], [5, 2, 10]);
* // => [1, 3, 4]
*/
function difference(array) {
return baseDifference(array, baseFlatten(arguments, true, true, 1));
}
/**
* Gets the first element or first `n` elements of an array. If a callback
* is provided elements at the beginning of the array are returned as long
* as the callback returns truey. The callback is bound to `thisArg` and
* invoked with three arguments; (value, index, array).
*
* If a property name is provided for `callback` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `callback` the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @alias head, take
* @category Arrays
* @param {Array} array The array to query.
* @param {Function|Object|number|string} [callback] The function called
* per element or the number of elements to return. If a property name or
* object is provided it will be used to create a "_.pluck" or "_.where"
* style callback, respectively.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {*} Returns the first element(s) of `array`.
* @example
*
* _.first([1, 2, 3]);
* // => 1
*
* _.first([1, 2, 3], 2);
* // => [1, 2]
*
* _.first([1, 2, 3], function(num) {
* return num < 3;
* });
* // => [1, 2]
*
* var characters = [
* { 'name': 'barney', 'blocked': true, 'employer': 'slate' },
* { 'name': 'fred', 'blocked': false, 'employer': 'slate' },
* { 'name': 'pebbles', 'blocked': true, 'employer': 'na' }
* ];
*
* // using "_.pluck" callback shorthand
* _.first(characters, 'blocked');
* // => [{ 'name': 'barney', 'blocked': true, 'employer': 'slate' }]
*
* // using "_.where" callback shorthand
* _.pluck(_.first(characters, { 'employer': 'slate' }), 'name');
* // => ['barney', 'fred']
*/
function first(array, callback, thisArg) {
var n = 0,
length = array ? array.length : 0;
if (typeof callback != 'number' && callback != null) {
var index = -1;
callback = createCallback(callback, thisArg, 3);
while (++index < length && callback(array[index], index, array)) {
n++;
}
} else {
n = callback;
if (n == null || thisArg) {
return array ? array[0] : undefined;
}
}
return slice(array, 0, nativeMin(nativeMax(0, n), length));
}
/**
* Flattens a nested array (the nesting can be to any depth). If `isShallow`
* is truey, the array will only be flattened a single level. If a callback
* is provided each element of the array is passed through the callback before
* flattening. The callback is bound to `thisArg` and invoked with three
* arguments; (value, index, array).
*
* If a property name is provided for `callback` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `callback` the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to flatten.
* @param {boolean} [isShallow=false] A flag to restrict flattening to a single level.
* @param {Function|Object|string} [callback=identity] The function called
* per iteration. If a property name or object is provided it will be used
* to create a "_.pluck" or "_.where" style callback, respectively.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {Array} Returns a new flattened array.
* @example
*
* _.flatten([1, [2], [3, [[4]]]]);
* // => [1, 2, 3, 4];
*
* _.flatten([1, [2], [3, [[4]]]], true);
* // => [1, 2, 3, [[4]]];
*
* var characters = [
* { 'name': 'barney', 'age': 30, 'pets': ['hoppy'] },
* { 'name': 'fred', 'age': 40, 'pets': ['baby puss', 'dino'] }
* ];
*
* // using "_.pluck" callback shorthand
* _.flatten(characters, 'pets');
* // => ['hoppy', 'baby puss', 'dino']
*/
function flatten(array, isShallow) {
return baseFlatten(array, isShallow);
}
/**
* Gets the index at which the first occurrence of `value` is found using
* strict equality for comparisons, i.e. `===`. If the array is already sorted
* providing `true` for `fromIndex` will run a faster binary search.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to search.
* @param {*} value The value to search for.
* @param {boolean|number} [fromIndex=0] The index to search from or `true`
* to perform a binary search on a sorted array.
* @returns {number} Returns the index of the matched value or `-1`.
* @example
*
* _.indexOf([1, 2, 3, 1, 2, 3], 2);
* // => 1
*
* _.indexOf([1, 2, 3, 1, 2, 3], 2, 3);
* // => 4
*
* _.indexOf([1, 1, 2, 2, 3, 3], 2, true);
* // => 2
*/
function indexOf(array, value, fromIndex) {
if (typeof fromIndex == 'number') {
var length = array ? array.length : 0;
fromIndex = (fromIndex < 0 ? nativeMax(0, length + fromIndex) : fromIndex || 0);
} else if (fromIndex) {
var index = sortedIndex(array, value);
return array[index] === value ? index : -1;
}
return baseIndexOf(array, value, fromIndex);
}
/**
* Gets all but the last element or last `n` elements of an array. If a
* callback is provided elements at the end of the array are excluded from
* the result as long as the callback returns truey. The callback is bound
* to `thisArg` and invoked with three arguments; (value, index, array).
*
* If a property name is provided for `callback` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `callback` the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to query.
* @param {Function|Object|number|string} [callback=1] The function called
* per element or the number of elements to exclude. If a property name or
* object is provided it will be used to create a "_.pluck" or "_.where"
* style callback, respectively.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {Array} Returns a slice of `array`.
* @example
*
* _.initial([1, 2, 3]);
* // => [1, 2]
*
* _.initial([1, 2, 3], 2);
* // => [1]
*
* _.initial([1, 2, 3], function(num) {
* return num > 1;
* });
* // => [1]
*
* var characters = [
* { 'name': 'barney', 'blocked': false, 'employer': 'slate' },
* { 'name': 'fred', 'blocked': true, 'employer': 'slate' },
* { 'name': 'pebbles', 'blocked': true, 'employer': 'na' }
* ];
*
* // using "_.pluck" callback shorthand
* _.initial(characters, 'blocked');
* // => [{ 'name': 'barney', 'blocked': false, 'employer': 'slate' }]
*
* // using "_.where" callback shorthand
* _.pluck(_.initial(characters, { 'employer': 'na' }), 'name');
* // => ['barney', 'fred']
*/
function initial(array, callback, thisArg) {
var n = 0,
length = array ? array.length : 0;
if (typeof callback != 'number' && callback != null) {
var index = length;
callback = createCallback(callback, thisArg, 3);
while (index-- && callback(array[index], index, array)) {
n++;
}
} else {
n = (callback == null || thisArg) ? 1 : callback || n;
}
return slice(array, 0, nativeMin(nativeMax(0, length - n), length));
}
/**
* Creates an array of unique values present in all provided arrays using
* strict equality for comparisons, i.e. `===`.
*
* @static
* @memberOf _
* @category Arrays
* @param {...Array} [array] The arrays to inspect.
* @returns {Array} Returns an array of shared values.
* @example
*
* _.intersection([1, 2, 3], [5, 2, 1, 4], [2, 1]);
* // => [1, 2]
*/
function intersection() {
var args = [],
argsIndex = -1,
argsLength = arguments.length;
while (++argsIndex < argsLength) {
var value = arguments[argsIndex];
if (isArray(value) || isArguments(value)) {
args.push(value);
}
}
var array = args[0],
index = -1,
indexOf = getIndexOf(),
length = array ? array.length : 0,
result = [];
outer:
while (++index < length) {
value = array[index];
if (indexOf(result, value) < 0) {
var argsIndex = argsLength;
while (--argsIndex) {
if (indexOf(args[argsIndex], value) < 0) {
continue outer;
}
}
result.push(value);
}
}
return result;
}
/**
* Gets the last element or last `n` elements of an array. If a callback is
* provided elements at the end of the array are returned as long as the
* callback returns truey. The callback is bound to `thisArg` and invoked
* with three arguments; (value, index, array).
*
* If a property name is provided for `callback` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `callback` the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to query.
* @param {Function|Object|number|string} [callback] The function called
* per element or the number of elements to return. If a property name or
* object is provided it will be used to create a "_.pluck" or "_.where"
* style callback, respectively.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {*} Returns the last element(s) of `array`.
* @example
*
* _.last([1, 2, 3]);
* // => 3
*
* _.last([1, 2, 3], 2);
* // => [2, 3]
*
* _.last([1, 2, 3], function(num) {
* return num > 1;
* });
* // => [2, 3]
*
* var characters = [
* { 'name': 'barney', 'blocked': false, 'employer': 'slate' },
* { 'name': 'fred', 'blocked': true, 'employer': 'slate' },
* { 'name': 'pebbles', 'blocked': true, 'employer': 'na' }
* ];
*
* // using "_.pluck" callback shorthand
* _.pluck(_.last(characters, 'blocked'), 'name');
* // => ['fred', 'pebbles']
*
* // using "_.where" callback shorthand
* _.last(characters, { 'employer': 'na' });
* // => [{ 'name': 'pebbles', 'blocked': true, 'employer': 'na' }]
*/
function last(array, callback, thisArg) {
var n = 0,
length = array ? array.length : 0;
if (typeof callback != 'number' && callback != null) {
var index = length;
callback = createCallback(callback, thisArg, 3);
while (index-- && callback(array[index], index, array)) {
n++;
}
} else {
n = callback;
if (n == null || thisArg) {
return array ? array[length - 1] : undefined;
}
}
return slice(array, nativeMax(0, length - n));
}
/**
* Gets the index at which the last occurrence of `value` is found using strict
* equality for comparisons, i.e. `===`. If `fromIndex` is negative, it is used
* as the offset from the end of the collection.
*
* If a property name is provided for `callback` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `callback` the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to search.
* @param {*} value The value to search for.
* @param {number} [fromIndex=array.length-1] The index to search from.
* @returns {number} Returns the index of the matched value or `-1`.
* @example
*
* _.lastIndexOf([1, 2, 3, 1, 2, 3], 2);
* // => 4
*
* _.lastIndexOf([1, 2, 3, 1, 2, 3], 2, 3);
* // => 1
*/
function lastIndexOf(array, value, fromIndex) {
var index = array ? array.length : 0;
if (typeof fromIndex == 'number') {
index = (fromIndex < 0 ? nativeMax(0, index + fromIndex) : nativeMin(fromIndex, index - 1)) + 1;
}
while (index--) {
if (array[index] === value) {
return index;
}
}
return -1;
}
/**
* Creates an array of numbers (positive and/or negative) progressing from
* `start` up to but not including `end`. If `start` is less than `stop` a
* zero-length range is created unless a negative `step` is specified.
*
* @static
* @memberOf _
* @category Arrays
* @param {number} [start=0] The start of the range.
* @param {number} end The end of the range.
* @param {number} [step=1] The value to increment or decrement by.
* @returns {Array} Returns a new range array.
* @example
*
* _.range(4);
* // => [0, 1, 2, 3]
*
* _.range(1, 5);
* // => [1, 2, 3, 4]
*
* _.range(0, 20, 5);
* // => [0, 5, 10, 15]
*
* _.range(0, -4, -1);
* // => [0, -1, -2, -3]
*
* _.range(1, 4, 0);
* // => [1, 1, 1]
*
* _.range(0);
* // => []
*/
function range(start, end, step) {
start = +start || 0;
step = (+step || 1);
if (end == null) {
end = start;
start = 0;
}
// use `Array(length)` so engines like Chakra and V8 avoid slower modes
// http://youtu.be/XAqIpGU8ZZk#t=17m25s
var index = -1,
length = nativeMax(0, ceil((end - start) / step)),
result = Array(length);
while (++index < length) {
result[index] = start;
start += step;
}
return result;
}
/**
* The opposite of `_.initial` this method gets all but the first element or
* first `n` elements of an array. If a callback function is provided elements
* at the beginning of the array are excluded from the result as long as the
* callback returns truey. The callback is bound to `thisArg` and invoked
* with three arguments; (value, index, array).
*
* If a property name is provided for `callback` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `callback` the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @alias drop, tail
* @category Arrays
* @param {Array} array The array to query.
* @param {Function|Object|number|string} [callback=1] The function called
* per element or the number of elements to exclude. If a property name or
* object is provided it will be used to create a "_.pluck" or "_.where"
* style callback, respectively.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {Array} Returns a slice of `array`.
* @example
*
* _.rest([1, 2, 3]);
* // => [2, 3]
*
* _.rest([1, 2, 3], 2);
* // => [3]
*
* _.rest([1, 2, 3], function(num) {
* return num < 3;
* });
* // => [3]
*
* var characters = [
* { 'name': 'barney', 'blocked': true, 'employer': 'slate' },
* { 'name': 'fred', 'blocked': false, 'employer': 'slate' },
* { 'name': 'pebbles', 'blocked': true, 'employer': 'na' }
* ];
*
* // using "_.pluck" callback shorthand
* _.pluck(_.rest(characters, 'blocked'), 'name');
* // => ['fred', 'pebbles']
*
* // using "_.where" callback shorthand
* _.rest(characters, { 'employer': 'slate' });
* // => [{ 'name': 'pebbles', 'blocked': true, 'employer': 'na' }]
*/
function rest(array, callback, thisArg) {
if (typeof callback != 'number' && callback != null) {
var n = 0,
index = -1,
length = array ? array.length : 0;
callback = createCallback(callback, thisArg, 3);
while (++index < length && callback(array[index], index, array)) {
n++;
}
} else {
n = (callback == null || thisArg) ? 1 : nativeMax(0, callback);
}
return slice(array, n);
}
/**
* Uses a binary search to determine the smallest index at which a value
* should be inserted into a given sorted array in order to maintain the sort
* order of the array. If a callback is provided it will be executed for
* `value` and each element of `array` to compute their sort ranking. The
* callback is bound to `thisArg` and invoked with one argument; (value).
*
* If a property name is provided for `callback` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `callback` the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to inspect.
* @param {*} value The value to evaluate.
* @param {Function|Object|string} [callback=identity] The function called
* per iteration. If a property name or object is provided it will be used
* to create a "_.pluck" or "_.where" style callback, respectively.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {number} Returns the index at which `value` should be inserted
* into `array`.
* @example
*
* _.sortedIndex([20, 30, 50], 40);
* // => 2
*
* // using "_.pluck" callback shorthand
* _.sortedIndex([{ 'x': 20 }, { 'x': 30 }, { 'x': 50 }], { 'x': 40 }, 'x');
* // => 2
*
* var dict = {
* 'wordToNumber': { 'twenty': 20, 'thirty': 30, 'fourty': 40, 'fifty': 50 }
* };
*
* _.sortedIndex(['twenty', 'thirty', 'fifty'], 'fourty', function(word) {
* return dict.wordToNumber[word];
* });
* // => 2
*
* _.sortedIndex(['twenty', 'thirty', 'fifty'], 'fourty', function(word) {
* return this.wordToNumber[word];
* }, dict);
* // => 2
*/
function sortedIndex(array, value, callback, thisArg) {
var low = 0,
high = array ? array.length : low;
// explicitly reference `identity` for better inlining in Firefox
callback = callback ? createCallback(callback, thisArg, 1) : identity;
value = callback(value);
while (low < high) {
var mid = (low + high) >>> 1;
(callback(array[mid]) < value)
? low = mid + 1
: high = mid;
}
return low;
}
/**
* Creates an array of unique values, in order, of the provided arrays using
* strict equality for comparisons, i.e. `===`.
*
* @static
* @memberOf _
* @category Arrays
* @param {...Array} [array] The arrays to inspect.
* @returns {Array} Returns an array of combined values.
* @example
*
* _.union([1, 2, 3], [5, 2, 1, 4], [2, 1]);
* // => [1, 2, 3, 5, 4]
*/
function union() {
return baseUniq(baseFlatten(arguments, true, true));
}
/**
* Creates a duplicate-value-free version of an array using strict equality
* for comparisons, i.e. `===`. If the array is sorted, providing
* `true` for `isSorted` will use a faster algorithm. If a callback is provided
* each element of `array` is passed through the callback before uniqueness
* is computed. The callback is bound to `thisArg` and invoked with three
* arguments; (value, index, array).
*
* If a property name is provided for `callback` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `callback` the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @alias unique
* @category Arrays
* @param {Array} array The array to process.
* @param {boolean} [isSorted=false] A flag to indicate that `array` is sorted.
* @param {Function|Object|string} [callback=identity] The function called
* per iteration. If a property name or object is provided it will be used
* to create a "_.pluck" or "_.where" style callback, respectively.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {Array} Returns a duplicate-value-free array.
* @example
*
* _.uniq([1, 2, 1, 3, 1]);
* // => [1, 2, 3]
*
* _.uniq([1, 1, 2, 2, 3], true);
* // => [1, 2, 3]
*
* _.uniq(['A', 'b', 'C', 'a', 'B', 'c'], function(letter) { return letter.toLowerCase(); });
* // => ['A', 'b', 'C']
*
* _.uniq([1, 2.5, 3, 1.5, 2, 3.5], function(num) { return this.floor(num); }, Math);
* // => [1, 2.5, 3]
*
* // using "_.pluck" callback shorthand
* _.uniq([{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }], 'x');
* // => [{ 'x': 1 }, { 'x': 2 }]
*/
function uniq(array, isSorted, callback, thisArg) {
// juggle arguments
if (typeof isSorted != 'boolean' && isSorted != null) {
thisArg = callback;
callback = (typeof isSorted != 'function' && thisArg && thisArg[isSorted] === array) ? null : isSorted;
isSorted = false;
}
if (callback != null) {
callback = createCallback(callback, thisArg, 3);
}
return baseUniq(array, isSorted, callback);
}
/**
* Creates an array excluding all provided values using strict equality for
* comparisons, i.e. `===`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to filter.
* @param {...*} [value] The values to exclude.
* @returns {Array} Returns a new array of filtered values.
* @example
*
* _.without([1, 2, 1, 0, 3, 1, 4], 0, 1);
* // => [2, 3, 4]
*/
function without(array) {
return baseDifference(array, slice(arguments, 1));
}
/**
* Creates an array of grouped elements, the first of which contains the first
* elements of the given arrays, the second of which contains the second
* elements of the given arrays, and so on.
*
* @static
* @memberOf _
* @alias unzip
* @category Arrays
* @param {...Array} [array] Arrays to process.
* @returns {Array} Returns a new array of grouped elements.
* @example
*
* _.zip(['fred', 'barney'], [30, 40], [true, false]);
* // => [['fred', 30, true], ['barney', 40, false]]
*/
function zip() {
var index = -1,
length = max(pluck(arguments, 'length')),
result = Array(length < 0 ? 0 : length);
while (++index < length) {
result[index] = pluck(arguments, index);
}
return result;
}
/**
* Creates an object composed from arrays of `keys` and `values`. Provide
* either a single two dimensional array, i.e. `[[key1, value1], [key2, value2]]`
* or two arrays, one of `keys` and one of corresponding `values`.
*
* @static
* @memberOf _
* @alias object
* @category Arrays
* @param {Array} keys The array of keys.
* @param {Array} [values=[]] The array of values.
* @returns {Object} Returns an object composed of the given keys and
* corresponding values.
* @example
*
* _.zipObject(['fred', 'barney'], [30, 40]);
* // => { 'fred': 30, 'barney': 40 }
*/
function zipObject(keys, values) {
var index = -1,
length = keys ? keys.length : 0,
result = {};
if (!values && length && !isArray(keys[0])) {
values = [];
}
while (++index < length) {
var key = keys[index];
if (values) {
result[key] = values[index];
} else if (key) {
result[key[0]] = key[1];
}
}
return result;
}
/*--------------------------------------------------------------------------*/
/**
* Creates a function that executes `func`, with the `this` binding and
* arguments of the created function, only after being called `n` times.
*
* @static
* @memberOf _
* @category Functions
* @param {number} n The number of times the function must be called before
* `func` is executed.
* @param {Function} func The function to restrict.
* @returns {Function} Returns the new restricted function.
* @example
*
* var saves = ['profile', 'settings'];
*
* var done = _.after(saves.length, function() {
* console.log('Done saving!');
* });
*
* _.forEach(saves, function(type) {
* asyncSave({ 'type': type, 'complete': done });
* });
* // => logs 'Done saving!', after all saves have completed
*/
function after(n, func) {
if (!isFunction(func)) {
throw new TypeError;
}
return function() {
if (--n < 1) {
return func.apply(this, arguments);
}
};
}
/**
* Creates a function that, when called, invokes `func` with the `this`
* binding of `thisArg` and prepends any additional `bind` arguments to those
* provided to the bound function.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to bind.
* @param {*} [thisArg] The `this` binding of `func`.
* @param {...*} [arg] Arguments to be partially applied.
* @returns {Function} Returns the new bound function.
* @example
*
* var func = function(greeting) {
* return greeting + ' ' + this.name;
* };
*
* func = _.bind(func, { 'name': 'fred' }, 'hi');
* func();
* // => 'hi fred'
*/
function bind(func, thisArg) {
return arguments.length > 2
? createWrapper(func, 17, slice(arguments, 2), null, thisArg)
: createWrapper(func, 1, null, null, thisArg);
}
/**
* Binds methods of an object to the object itself, overwriting the existing
* method. Method names may be specified as individual arguments or as arrays
* of method names. If no method names are provided all the function properties
* of `object` will be bound.
*
* @static
* @memberOf _
* @category Functions
* @param {Object} object The object to bind and assign the bound methods to.
* @param {...string} [methodName] The object method names to
* bind, specified as individual method names or arrays of method names.
* @returns {Object} Returns `object`.
* @example
*
* var view = {
* 'label': 'docs',
* 'onClick': function() { console.log('clicked ' + this.label); }
* };
*
* _.bindAll(view);
* jQuery('#docs').on('click', view.onClick);
* // => logs 'clicked docs', when the button is clicked
*/
function bindAll(object) {
var funcs = arguments.length > 1 ? baseFlatten(arguments, true, false, 1) : functions(object),
index = -1,
length = funcs.length;
while (++index < length) {
var key = funcs[index];
object[key] = createWrapper(object[key], 1, null, null, object);
}
return object;
}
/**
* Creates a function that is the composition of the provided functions,
* where each function consumes the return value of the function that follows.
* For example, composing the functions `f()`, `g()`, and `h()` produces `f(g(h()))`.
* Each function is executed with the `this` binding of the composed function.
*
* @static
* @memberOf _
* @category Functions
* @param {...Function} [func] Functions to compose.
* @returns {Function} Returns the new composed function.
* @example
*
* var realNameMap = {
* 'pebbles': 'penelope'
* };
*
* var format = function(name) {
* name = realNameMap[name.toLowerCase()] || name;
* return name.charAt(0).toUpperCase() + name.slice(1).toLowerCase();
* };
*
* var greet = function(formatted) {
* return 'Hiya ' + formatted + '!';
* };
*
* var welcome = _.compose(greet, format);
* welcome('pebbles');
* // => 'Hiya Penelope!'
*/
function compose() {
var funcs = arguments,
length = funcs.length;
while (length--) {
if (!isFunction(funcs[length])) {
throw new TypeError;
}
}
return function() {
var args = arguments,
length = funcs.length;
while (length--) {
args = [funcs[length].apply(this, args)];
}
return args[0];
};
}
/**
* Creates a function that will delay the execution of `func` until after
* `wait` milliseconds have elapsed since the last time it was invoked.
* Provide an options object to indicate that `func` should be invoked on
* the leading and/or trailing edge of the `wait` timeout. Subsequent calls
* to the debounced function will return the result of the last `func` call.
*
* Note: If `leading` and `trailing` options are `true` `func` will be called
* on the trailing edge of the timeout only if the the debounced function is
* invoked more than once during the `wait` timeout.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to debounce.
* @param {number} wait The number of milliseconds to delay.
* @param {Object} [options] The options object.
* @param {boolean} [options.leading=false] Specify execution on the leading edge of the timeout.
* @param {number} [options.maxWait] The maximum time `func` is allowed to be delayed before it's called.
* @param {boolean} [options.trailing=true] Specify execution on the trailing edge of the timeout.
* @returns {Function} Returns the new debounced function.
* @example
*
* // avoid costly calculations while the window size is in flux
* var lazyLayout = _.debounce(calculateLayout, 150);
* jQuery(window).on('resize', lazyLayout);
*
* // execute `sendMail` when the click event is fired, debouncing subsequent calls
* jQuery('#postbox').on('click', _.debounce(sendMail, 300, {
* 'leading': true,
* 'trailing': false
* });
*
* // ensure `batchLog` is executed once after 1 second of debounced calls
* var source = new EventSource('/stream');
* source.addEventListener('message', _.debounce(batchLog, 250, {
* 'maxWait': 1000
* }, false);
*/
function debounce(func, wait, options) {
var args,
maxTimeoutId,
result,
stamp,
thisArg,
timeoutId,
trailingCall,
lastCalled = 0,
maxWait = false,
trailing = true;
if (!isFunction(func)) {
throw new TypeError;
}
wait = nativeMax(0, wait) || 0;
if (options === true) {
var leading = true;
trailing = false;
} else if (isObject(options)) {
leading = options.leading;
maxWait = 'maxWait' in options && (nativeMax(wait, options.maxWait) || 0);
trailing = 'trailing' in options ? options.trailing : trailing;
}
var delayed = function() {
var remaining = wait - (now() - stamp);
if (remaining <= 0) {
if (maxTimeoutId) {
clearTimeout(maxTimeoutId);
}
var isCalled = trailingCall;
maxTimeoutId = timeoutId = trailingCall = undefined;
if (isCalled) {
lastCalled = now();
result = func.apply(thisArg, args);
if (!timeoutId && !maxTimeoutId) {
args = thisArg = null;
}
}
} else {
timeoutId = setTimeout(delayed, remaining);
}
};
var maxDelayed = function() {
if (timeoutId) {
clearTimeout(timeoutId);
}
maxTimeoutId = timeoutId = trailingCall = undefined;
if (trailing || (maxWait !== wait)) {
lastCalled = now();
result = func.apply(thisArg, args);
if (!timeoutId && !maxTimeoutId) {
args = thisArg = null;
}
}
};
return function() {
args = arguments;
stamp = now();
thisArg = this;
trailingCall = trailing && (timeoutId || !leading);
if (maxWait === false) {
var leadingCall = leading && !timeoutId;
} else {
if (!maxTimeoutId && !leading) {
lastCalled = stamp;
}
var remaining = maxWait - (stamp - lastCalled),
isCalled = remaining <= 0;
if (isCalled) {
if (maxTimeoutId) {
maxTimeoutId = clearTimeout(maxTimeoutId);
}
lastCalled = stamp;
result = func.apply(thisArg, args);
}
else if (!maxTimeoutId) {
maxTimeoutId = setTimeout(maxDelayed, remaining);
}
}
if (isCalled && timeoutId) {
timeoutId = clearTimeout(timeoutId);
}
else if (!timeoutId && wait !== maxWait) {
timeoutId = setTimeout(delayed, wait);
}
if (leadingCall) {
isCalled = true;
result = func.apply(thisArg, args);
}
if (isCalled && !timeoutId && !maxTimeoutId) {
args = thisArg = null;
}
return result;
};
}
/**
* Defers executing the `func` function until the current call stack has cleared.
* Additional arguments will be provided to `func` when it is invoked.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to defer.
* @param {...*} [arg] Arguments to invoke the function with.
* @returns {number} Returns the timer id.
* @example
*
* _.defer(function(text) { console.log(text); }, 'deferred');
* // logs 'deferred' after one or more milliseconds
*/
function defer(func) {
if (!isFunction(func)) {
throw new TypeError;
}
var args = slice(arguments, 1);
return setTimeout(function() { func.apply(undefined, args); }, 1);
}
/**
* Executes the `func` function after `wait` milliseconds. Additional arguments
* will be provided to `func` when it is invoked.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to delay.
* @param {number} wait The number of milliseconds to delay execution.
* @param {...*} [arg] Arguments to invoke the function with.
* @returns {number} Returns the timer id.
* @example
*
* _.delay(function(text) { console.log(text); }, 1000, 'later');
* // => logs 'later' after one second
*/
function delay(func, wait) {
if (!isFunction(func)) {
throw new TypeError;
}
var args = slice(arguments, 2);
return setTimeout(function() { func.apply(undefined, args); }, wait);
}
/**
* Creates a function that memoizes the result of `func`. If `resolver` is
* provided it will be used to determine the cache key for storing the result
* based on the arguments provided to the memoized function. By default, the
* first argument provided to the memoized function is used as the cache key.
* The `func` is executed with the `this` binding of the memoized function.
* The result cache is exposed as the `cache` property on the memoized function.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to have its output memoized.
* @param {Function} [resolver] A function used to resolve the cache key.
* @returns {Function} Returns the new memoizing function.
* @example
*
* var fibonacci = _.memoize(function(n) {
* return n < 2 ? n : fibonacci(n - 1) + fibonacci(n - 2);
* });
*
* fibonacci(9)
* // => 34
*
* var data = {
* 'fred': { 'name': 'fred', 'age': 40 },
* 'pebbles': { 'name': 'pebbles', 'age': 1 }
* };
*
* // modifying the result cache
* var get = _.memoize(function(name) { return data[name]; }, _.identity);
* get('pebbles');
* // => { 'name': 'pebbles', 'age': 1 }
*
* get.cache.pebbles.name = 'penelope';
* get('pebbles');
* // => { 'name': 'penelope', 'age': 1 }
*/
function memoize(func, resolver) {
var cache = {};
return function() {
var key = resolver ? resolver.apply(this, arguments) : keyPrefix + arguments[0];
return hasOwnProperty.call(cache, key)
? cache[key]
: (cache[key] = func.apply(this, arguments));
};
}
/**
* Creates a function that is restricted to execute `func` once. Repeat calls to
* the function will return the value of the first call. The `func` is executed
* with the `this` binding of the created function.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to restrict.
* @returns {Function} Returns the new restricted function.
* @example
*
* var initialize = _.once(createApplication);
* initialize();
* initialize();
* // `initialize` executes `createApplication` once
*/
function once(func) {
var ran,
result;
if (!isFunction(func)) {
throw new TypeError;
}
return function() {
if (ran) {
return result;
}
ran = true;
result = func.apply(this, arguments);
// clear the `func` variable so the function may be garbage collected
func = null;
return result;
};
}
/**
* Creates a function that, when called, invokes `func` with any additional
* `partial` arguments prepended to those provided to the new function. This
* method is similar to `_.bind` except it does **not** alter the `this` binding.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to partially apply arguments to.
* @param {...*} [arg] Arguments to be partially applied.
* @returns {Function} Returns the new partially applied function.
* @example
*
* var greet = function(greeting, name) { return greeting + ' ' + name; };
* var hi = _.partial(greet, 'hi');
* hi('fred');
* // => 'hi fred'
*/
function partial(func) {
return createWrapper(func, 16, slice(arguments, 1));
}
/**
* Creates a function that, when executed, will only call the `func` function
* at most once per every `wait` milliseconds. Provide an options object to
* indicate that `func` should be invoked on the leading and/or trailing edge
* of the `wait` timeout. Subsequent calls to the throttled function will
* return the result of the last `func` call.
*
* Note: If `leading` and `trailing` options are `true` `func` will be called
* on the trailing edge of the timeout only if the the throttled function is
* invoked more than once during the `wait` timeout.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to throttle.
* @param {number} wait The number of milliseconds to throttle executions to.
* @param {Object} [options] The options object.
* @param {boolean} [options.leading=true] Specify execution on the leading edge of the timeout.
* @param {boolean} [options.trailing=true] Specify execution on the trailing edge of the timeout.
* @returns {Function} Returns the new throttled function.
* @example
*
* // avoid excessively updating the position while scrolling
* var throttled = _.throttle(updatePosition, 100);
* jQuery(window).on('scroll', throttled);
*
* // execute `renewToken` when the click event is fired, but not more than once every 5 minutes
* jQuery('.interactive').on('click', _.throttle(renewToken, 300000, {
* 'trailing': false
* }));
*/
function throttle(func, wait, options) {
var leading = true,
trailing = true;
if (!isFunction(func)) {
throw new TypeError;
}
if (options === false) {
leading = false;
} else if (isObject(options)) {
leading = 'leading' in options ? options.leading : leading;
trailing = 'trailing' in options ? options.trailing : trailing;
}
options = {};
options.leading = leading;
options.maxWait = wait;
options.trailing = trailing;
return debounce(func, wait, options);
}
/**
* Creates a function that provides `value` to the wrapper function as its
* first argument. Additional arguments provided to the function are appended
* to those provided to the wrapper function. The wrapper is executed with
* the `this` binding of the created function.
*
* @static
* @memberOf _
* @category Functions
* @param {*} value The value to wrap.
* @param {Function} wrapper The wrapper function.
* @returns {Function} Returns the new function.
* @example
*
* var p = _.wrap(_.escape, function(func, text) {
* return '' + func(text) + '
';
* });
*
* p('Fred, Wilma, & Pebbles');
* // => 'Fred, Wilma, & Pebbles
'
*/
function wrap(value, wrapper) {
return createWrapper(wrapper, 16, [value]);
}
/*--------------------------------------------------------------------------*/
/**
* Produces a callback bound to an optional `thisArg`. If `func` is a property
* name the created callback will return the property value for a given element.
* If `func` is an object the created callback will return `true` for elements
* that contain the equivalent object properties, otherwise it will return `false`.
*
* @static
* @memberOf _
* @category Utilities
* @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.
* @example
*
* var characters = [
* { 'name': 'barney', 'age': 36 },
* { 'name': 'fred', 'age': 40 }
* ];
*
* // wrap to create custom callback shorthands
* _.createCallback = _.wrap(_.createCallback, function(func, callback, thisArg) {
* var match = /^(.+?)__([gl]t)(.+)$/.exec(callback);
* return !match ? func(callback, thisArg) : function(object) {
* return match[2] == 'gt' ? object[match[1]] > match[3] : object[match[1]] < match[3];
* };
* });
*
* _.filter(characters, 'age__gt38');
* // => [{ 'name': 'fred', 'age': 40 }]
*/
function createCallback(func, thisArg, argCount) {
var type = typeof func;
if (func == null || type == 'function') {
return baseCreateCallback(func, thisArg, argCount);
}
// handle "_.pluck" style callback shorthands
if (type != 'object') {
return property(func);
}
var props = keys(func);
return function(object) {
var length = props.length,
result = false;
while (length--) {
if (!(result = object[props[length]] === func[props[length]])) {
break;
}
}
return result;
};
}
/**
* Converts the characters `&`, `<`, `>`, `"`, and `'` in `string` to their
* corresponding HTML entities.
*
* @static
* @memberOf _
* @category Utilities
* @param {string} string The string to escape.
* @returns {string} Returns the escaped string.
* @example
*
* _.escape('Fred, Wilma, & Pebbles');
* // => 'Fred, Wilma, & Pebbles'
*/
function escape(string) {
return string == null ? '' : String(string).replace(reUnescapedHtml, escapeHtmlChar);
}
/**
* This method returns the first argument provided to it.
*
* @static
* @memberOf _
* @category Utilities
* @param {*} value Any value.
* @returns {*} Returns `value`.
* @example
*
* var object = { 'name': 'fred' };
* _.identity(object) === object;
* // => true
*/
function identity(value) {
return value;
}
/**
* Adds function properties of a source object to the destination object.
* If `object` is a function methods will be added to its prototype as well.
*
* @static
* @memberOf _
* @category Utilities
* @param {Function|Object} [object=lodash] object The destination object.
* @param {Object} source The object of functions to add.
* @param {Object} [options] The options object.
* @param {boolean} [options.chain=true] Specify whether the functions added are chainable.
* @example
*
* function capitalize(string) {
* return string.charAt(0).toUpperCase() + string.slice(1).toLowerCase();
* }
*
* _.mixin({ 'capitalize': capitalize });
* _.capitalize('fred');
* // => 'Fred'
*
* _('fred').capitalize().value();
* // => 'Fred'
*
* _.mixin({ 'capitalize': capitalize }, { 'chain': false });
* _('fred').capitalize();
* // => 'Fred'
*/
function mixin(object) {
forEach(functions(object), function(methodName) {
var func = lodash[methodName] = object[methodName];
lodash.prototype[methodName] = function() {
var args = [this.__wrapped__];
push.apply(args, arguments);
var result = func.apply(lodash, args);
return this.__chain__
? new lodashWrapper(result, true)
: result;
};
});
}
/**
* Reverts the '_' variable to its previous value and returns a reference to
* the `lodash` function.
*
* @static
* @memberOf _
* @category Utilities
* @returns {Function} Returns the `lodash` function.
* @example
*
* var lodash = _.noConflict();
*/
function noConflict() {
root._ = oldDash;
return this;
}
/**
* A no-operation function.
*
* @static
* @memberOf _
* @category Utilities
* @example
*
* var object = { 'name': 'fred' };
* _.noop(object) === undefined;
* // => true
*/
function noop() {
// no operation performed
}
/**
* Gets the number of milliseconds that have elapsed since the Unix epoch
* (1 January 1970 00:00:00 UTC).
*
* @static
* @memberOf _
* @category Utilities
* @example
*
* var stamp = _.now();
* _.defer(function() { console.log(_.now() - stamp); });
* // => logs the number of milliseconds it took for the deferred function to be called
*/
var now = reNative.test(now = Date.now) && now || function() {
return new Date().getTime();
};
/**
* Creates a "_.pluck" style function, which returns the `key` value of a
* given object.
*
* @static
* @memberOf _
* @category Utilities
* @param {string} key The name of the property to retrieve.
* @returns {Function} Returns the new function.
* @example
*
* var characters = [
* { 'name': 'fred', 'age': 40 },
* { 'name': 'barney', 'age': 36 }
* ];
*
* var getName = _.property('name');
*
* _.map(characters, getName);
* // => ['barney', 'fred']
*
* _.sortBy(characters, getName);
* // => [{ 'name': 'barney', 'age': 36 }, { 'name': 'fred', 'age': 40 }]
*/
function property(key) {
return function(object) {
return object[key];
};
}
/**
* Produces a random number between `min` and `max` (inclusive). If only one
* argument is provided a number between `0` and the given number will be
* returned. If `floating` is truey or either `min` or `max` are floats a
* floating-point number will be returned instead of an integer.
*
* @static
* @memberOf _
* @category Utilities
* @param {number} [min=0] The minimum possible value.
* @param {number} [max=1] The maximum possible value.
* @param {boolean} [floating=false] Specify returning a floating-point number.
* @returns {number} Returns a random number.
* @example
*
* _.random(0, 5);
* // => an integer between 0 and 5
*
* _.random(5);
* // => also an integer between 0 and 5
*
* _.random(5, true);
* // => a floating-point number between 0 and 5
*
* _.random(1.2, 5.2);
* // => a floating-point number between 1.2 and 5.2
*/
function random(min, max) {
if (min == null && max == null) {
max = 1;
}
min = +min || 0;
if (max == null) {
max = min;
min = 0;
} else {
max = +max || 0;
}
return min + floor(nativeRandom() * (max - min + 1));
}
/**
* Resolves the value of property `key` on `object`. If `key` is a function
* it will be invoked with the `this` binding of `object` and its result returned,
* else the property value is returned. If `object` is falsey then `undefined`
* is returned.
*
* @static
* @memberOf _
* @category Utilities
* @param {Object} object The object to inspect.
* @param {string} key The name of the property to resolve.
* @returns {*} Returns the resolved value.
* @example
*
* var object = {
* 'cheese': 'crumpets',
* 'stuff': function() {
* return 'nonsense';
* }
* };
*
* _.result(object, 'cheese');
* // => 'crumpets'
*
* _.result(object, 'stuff');
* // => 'nonsense'
*/
function result(object, key) {
if (object) {
var value = object[key];
return isFunction(value) ? object[key]() : value;
}
}
/**
* A micro-templating method that handles arbitrary delimiters, preserves
* whitespace, and correctly escapes quotes within interpolated code.
*
* Note: In the development build, `_.template` utilizes sourceURLs for easier
* debugging. See http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl
*
* For more information on precompiling templates see:
* http://lodash.com/custom-builds
*
* For more information on Chrome extension sandboxes see:
* http://developer.chrome.com/stable/extensions/sandboxingEval.html
*
* @static
* @memberOf _
* @category Utilities
* @param {string} text The template text.
* @param {Object} data The data object used to populate the text.
* @param {Object} [options] The options object.
* @param {RegExp} [options.escape] The "escape" delimiter.
* @param {RegExp} [options.evaluate] The "evaluate" delimiter.
* @param {Object} [options.imports] An object to import into the template as local variables.
* @param {RegExp} [options.interpolate] The "interpolate" delimiter.
* @param {string} [sourceURL] The sourceURL of the template's compiled source.
* @param {string} [variable] The data object variable name.
* @returns {Function|string} Returns a compiled function when no `data` object
* is given, else it returns the interpolated text.
* @example
*
* // using the "interpolate" delimiter to create a compiled template
* var compiled = _.template('hello <%= name %>');
* compiled({ 'name': 'fred' });
* // => 'hello fred'
*
* // using the "escape" delimiter to escape HTML in data property values
* _.template('<%- value %>', { 'value': '