/**
* @license
* Lo-Dash 2.4.1 (Custom Build)
* Build: `lodash underscore -o ./dist/lodash.underscore.js`
* Copyright 2012-2014 The Dojo Foundation
* Based on Underscore.js 1.6.0
* 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 compose bitmasks for wrapper metadata */
var BIND_FLAG = 1,
BIND_KEY_FLAG = 2,
CURRY_FLAG = 4,
CURRY_BOUND_FLAG = 8,
PARTIAL_FLAG = 16,
PARTIAL_RIGHT_FLAG = 32;
/** Used as the semantic version number */
var version = '2.4.1';
/** Used as the property name for wrapper metadata */
var expando = '__lodash@' + version + '__';
/** Used by methods to exit iteration */
var breakIndicator = expando + 'breaker__';
/** Used to generate unique IDs */
var idCounter = 0;
/** Used to match HTML entities and HTML characters */
var reEscapedHtml = /&(?:amp|lt|gt|quot|#x27);/g,
reUnescapedHtml = /[&<>"']/g;
/** Used to match template delimiters */
var reEscape = /<%-([\s\S]+?)%>/g,
reEvaluate = /<%([\s\S]+?)%>/g,
reInterpolate = /<%=([\s\S]+?)%>/g;
/** Used to ensure capturing order of template delimiters */
var reNoMatch = /($^)/;
/**
* Used to match RegExp special characters.
* See this [article on RegExp characters](http://www.regular-expressions.info/characters.html#special)
* for more details.
*/
var reRegExpChars = /[.*+?^${}()|[\]\\]/g;
/** 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 convert characters to HTML entities.
*
* Note: 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 unquoted attribute value.
* See [Mathias' article](http://mathiasbynens.be/notes/ambiguous-ampersands)
* (under "semi-related fun fact") for more details.
*/
var htmlEscapes = {
'&': '&',
'<': '<',
'>': '>',
'"': '"',
"'": '''
};
/** Used to convert HTML entities to characters */
var htmlUnescapes = {
'&': '&',
'<': '<',
'>': '>',
'"': '"',
''': "'"
};
/** Used to determine if values are of the language type Object */
var objectTypes = {
'function': true,
'object': true
};
/** 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 free variable `global` from Node.js or Browserified code and use it as `root` */
var freeGlobal = freeExports && freeModule && typeof global == 'object' && global;
if (freeGlobal && (freeGlobal.global === freeGlobal || freeGlobal.window === freeGlobal || freeGlobal.self === freeGlobal)) {
root = freeGlobal;
}
/** Detect the popular CommonJS extension `module.exports` */
var moduleExports = freeModule && freeModule.exports === freeExports && freeExports;
/*--------------------------------------------------------------------------*/
/**
* The base implementation of `compareAscending` used to compare values and
* sort them in ascending order without guaranteeing a stable sort.
*
* @private
* @param {*} a The value to compare to `b`.
* @param {*} b The value to compare to `a`.
* @returns {number} Returns the sort order indicator for `a`.
*/
function baseCompareAscending(a, b) {
if (a !== b) {
if (a > b || typeof a == 'undefined') {
return 1;
}
if (a < b || typeof b == 'undefined') {
return -1;
}
}
return 0;
}
/**
* The base implementation of `_.indexOf` without support for binary searches.
*
* @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, else `-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 elements of a collection and stable
* sort 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 for `a`.
*/
function compareAscending(a, b) {
return baseCompareAscending(a.criteria, b.criteria) || a.index - b.index;
}
/**
* Used by `escape` to convert characters to HTML entities.
*
* @private
* @param {string} chr The matched character to escape.
* @returns {string} Returns the escaped character.
*/
function escapeHtmlChar(chr) {
return htmlEscapes[chr];
}
/**
* Used by `template` to escape characters for inclusion in compiled
* string literals.
*
* @private
* @param {string} chr The matched character to escape.
* @returns {string} Returns the escaped character.
*/
function escapeStringChar(chr) {
return '\\' + stringEscapes[chr];
}
/**
* Used by `unescape` to convert HTML entities to characters.
*
* @private
* @param {string} chr The matched character to unescape.
* @returns {string} Returns the unescaped character.
*/
function unescapeHtmlChar(chr) {
return htmlUnescapes[chr];
}
/*--------------------------------------------------------------------------*/
/** Used for native method references */
var arrayRef = Array.prototype,
objectProto = Object.prototype;
/** Used to restore the original `_` reference in `noConflict` */
var oldDash = root._;
/**
* Used as the maximum length an array-like object.
* See the [ES6 spec](http://people.mozilla.org/~jorendorff/es6-draft.html#sec-tolength)
* for more details.
*/
var maxSafeInteger = Math.pow(2, 53) - 1;
/** Used to resolve the internal [[Class]] of values */
var toString = objectProto.toString;
/** Used to detect if a method is native */
var reNative = RegExp('^' +
escapeRegExp(toString)
.replace(/toString|(function).*?(?=\\\()| for .+?(?=\\\])/g, '$1.*?') + '$'
);
/** Native method shortcuts */
var ceil = Math.ceil,
floor = Math.floor,
fnToString = Function.prototype.toString,
hasOwnProperty = objectProto.hasOwnProperty,
push = arrayRef.push,
propertyIsEnumerable = objectProto.propertyIsEnumerable,
splice = arrayRef.splice;
/* Native method shortcuts for methods with the same name as other `lodash` methods */
var nativeCreate = isNative(nativeCreate = Object.create) && nativeCreate,
nativeIsArray = isNative(nativeIsArray = Array.isArray) && nativeIsArray,
nativeIsFinite = root.isFinite,
nativeIsNaN = root.isNaN,
nativeKeys = isNative(nativeKeys = Object.keys) && nativeKeys,
nativeMax = Math.max,
nativeMin = Math.min,
nativeNow = isNative(nativeNow = Date.now) && nativeNow,
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`, `at`, `bind`, `bindAll`, `bindKey`, `chain`, `compact`,
* `compose`, `concat`, `constant`, `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`, `mapValues`, `matches`, `max`, `memoize`,
* `merge`, `min`, `noop`, `object`, `omit`, `once`, `pairs`, `partial`,
* `partialRight`, `pick`, `pluck`, `property`, `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`, `xor`,
* and `zip`
*
* The non-chainable wrapper functions are:
* `capitalize`, `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`, `now`,
* `parseInt`, `pop`, `random`, `reduce`, `reduceRight`, `result`, `shift`,
* `size`, `some`, `sortedIndex`, `runInContext`, `template`, `trim`,
* `trimLeft`, `trimRight`, `unescape`, `uniqueId`, and `value`
*
* The wrapper functions `first`, `last`, and `sample` 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=false] 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 = (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': reEscape,
/**
* Used to detect code to be evaluated.
*
* @memberOf _.templateSettings
* @type RegExp
*/
'evaluate': reEvaluate,
/**
* 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 `_.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) {
return isObject(prototype) ? nativeCreate(prototype) : {};
}
// fallback for environments 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 the new 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} data The metadata array.
* @returns {Function} Returns the new function.
*/
function baseCreateWrapper(data) {
var func = data[0],
bitmask = data[1],
arity = data[2],
thisArg = data[3],
partialArgs = data[4],
partialRightArgs = data[5],
partialHolders = data[6],
partialRightHolders = data[7];
var isBind = bitmask & BIND_FLAG,
isBindKey = bitmask & BIND_KEY_FLAG,
isCurry = bitmask & CURRY_FLAG,
isCurryBound = bitmask & CURRY_BOUND_FLAG,
key = func;
function bound() {
var index = -1,
length = arguments.length,
args = Array(length);
while (++index < length) {
args[index] = arguments[index];
}
if (partialArgs) {
args = composeArgs(partialArgs, partialHolders, args);
}
var thisBinding = isBind ? thisArg : this;
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 the new array of filtered values.
*/
function baseDifference(array, values) {
var length = array ? array.length : 0;
if (!length) {
return [];
}
var index = -1,
indexOf = getIndexOf(),
result = [];
while (++index < length) {
var value = array[index];
if (indexOf(values, value) < 0) {
result.push(value);
}
}
return result;
}
/**
* The base implementation of `_.forEach` without support for callback
* shorthands or `this` binding.
*
* @private
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Function} callback The function called per iteration.
* @returns {Array|Object|string} Returns `collection`.
*/
function baseEach(collection, callback) {
var index = -1,
iterable = collection,
length = collection ? collection.length : 0;
if (typeof length == 'number' && length > -1 && length <= maxSafeInteger) {
while (++index < length) {
if (callback(iterable[index], index, collection) === breakIndicator) {
break;
}
}
} else {
baseForOwn(collection, callback);
}
return collection;
}
/**
* The base implementation of `_.forEachRight` without support for callback
* shorthands or `this` binding.
*
* @private
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Function} callback The function called per iteration.
* @returns {Array|Object|string} Returns `collection`.
*/
function baseEachRight(collection, callback) {
var iterable = collection,
length = collection ? collection.length : 0;
if (typeof length == 'number' && length > -1 && length <= maxSafeInteger) {
while (length--) {
if (callback(iterable[length], length, collection) === breakIndicator) {
break;
}
}
} else {
baseForOwnRight(collection, callback);
}
return collection;
}
/**
* The base implementation of `find`, 'findLast`, `findKey`, and `findLastKey`
* without support for callback shorthands or `this` binding which iterates
* over `collection` using the provided `eachFunc`.
*
* @private
* @param {Array|Object|string} collection The collection to search.
* @param {Function} predicate The function called per iteration.
* @param {Function} eachFunc The function to iterate over the collection.
* @param {boolean} [retKey=false] A flag to indicate returning the key of
* the found element instead of the element itself.
* @returns {*} Returns the found element or its key, else `undefined`.
*/
function baseFind(collection, predicate, eachFunc, retKey) {
var result;
eachFunc(collection, function(value, key, collection) {
if (predicate(value, key, collection)) {
result = retKey ? key : value;
return breakIndicator;
}
});
return result;
}
/**
* The base implementation of `_.flatten` without support for callback
* shorthands or `this` 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 the 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 `baseForIn` and `baseForOwn` which iterates
* over `object` properties returned by `keysFunc` executing the callback
* for each property. Callbacks may exit iteration early by explicitly
* returning `false`.
*
* @private
* @param {Object} object The object to iterate over.
* @param {Function} callback The function called per iteration.
* @param {Function} keysFunc The function to get the keys of `object`.
* @returns {Object} Returns `object`.
*/
function baseFor(object, callback, keysFunc) {
var index = -1,
props = keysFunc(object),
length = props.length;
while (++index < length) {
var key = props[index];
if (callback(object[key], key, object) === breakIndicator) {
break;
}
}
return object;
}
/**
* This function is like `baseFor` except that it iterates over properties
* in the opposite order.
*
* @private
* @param {Object} object The object to iterate over.
* @param {Function} callback The function called per iteration.
* @param {Function} keysFunc The function to get the keys of `object`.
* @returns {Object} Returns `object`.
*/
function baseForRight(object, callback, keysFunc) {
var index = -1,
props = keysFunc(object),
length = props.length;
while (length--) {
var key = props[length];
if (callback(object[key], key, object) === breakIndicator) {
break;
}
}
return object;
}
/**
* The base implementation of `_.forIn` without support for callback
* shorthands or `this` binding.
*
* @private
* @param {Object} object The object to iterate over.
* @param {Function} callback The function called per iteration.
* @returns {Object} Returns `object`.
*/
function baseForIn(object, callback) {
return baseFor(object, callback, keysIn);
}
/**
* The base implementation of `_.forOwn` without support for callback
* shorthands or `this` binding.
*
* @private
* @param {Object} object The object to iterate over.
* @param {Function} callback The function called per iteration.
* @returns {Object} Returns `object`.
*/
function baseForOwn(object, callback) {
return baseFor(object, callback, keys);
}
/**
* The base implementation of `_.forOwnRight` without support for callback
* shorthands or `this` binding.
*
* @private
* @param {Object} object The object to iterate over.
* @param {Function} callback The function called per iteration.
* @returns {Object} Returns `object`.
*/
function baseForOwnRight(object, callback) {
return baseForRight(object, callback, keys);
}
/**
* 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 == null || b == null ||
(type != 'function' && type != 'object' && otherType != 'function' && otherType != 'object'))) {
return false;
}
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 ownCtorA = hasOwnProperty.call(a, 'constructor'),
ownCtorB = hasOwnProperty.call(b, 'constructor');
if (ownCtorA !== ownCtorB) {
return false;
}
if (!ownCtorA) {
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;
}
}
}
}
else {
baseForIn(b, function(value, key, b) {
if (hasOwnProperty.call(b, key)) {
size++;
return !(result = hasOwnProperty.call(a, key) && baseIsEqual(a[key], value, stackA, stackB)) && breakIndicator;
}
});
if (result) {
baseForIn(a, function(value, key, a) {
if (hasOwnProperty.call(a, key)) {
return !(result = --size > -1) && breakIndicator;
}
});
}
}
stackA.pop();
stackB.pop();
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 the random number.
*/
function baseRandom(min, max) {
return min + floor(nativeRandom() * (max - min + 1));
}
/**
* The base implementation of `_.uniq` without support for callback shorthands
* or `this` 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 the new duplicate-value-free array.
*/
function baseUniq(array, isSorted, callback) {
var length = array ? array.length : 0;
if (!length) {
return [];
}
var index = -1,
indexOf = getIndexOf(),
result = [],
seen = (callback && !isSorted) ? [] : result;
while (++index < length) {
var value = array[index],
computed = callback ? callback(value, index, array) : value;
if (isSorted) {
if (!index || seen !== computed) {
seen = computed;
result.push(value);
}
}
else if (indexOf(seen, computed) < 0) {
if (callback) {
seen.push(computed);
}
result.push(value);
}
}
return result;
}
/**
* The base implementation of `_.values` and `_.valuesIn` which creates an
* array of `object` property values corresponding to the property names
* returned by `keysFunc`.
*
* @private
* @param {Object} object The object to inspect.
* @param {Function} keysFunc The function to get the keys of `object`.
* @returns {Object} Returns the array of property values.
*/
function baseValues(object, keysFunc) {
var index = -1,
props = keysFunc(object),
length = props.length,
result = Array(length);
while (++index < length) {
result[index] = object[props[index]];
}
return result;
}
/**
* Creates an array that is the composition of partially applied arguments,
* placeholders, and provided arguments into a single array of arguments.
*
* @private
* @param {Array} partialArg An array of arguments to prepend to those provided.
* @param {Array} partialHolders An array of `partialArgs` placeholder indexes.
* @param {Array|Object} args The provided arguments.
* @returns {Array} Returns the new array of composed arguments.
*/
function composeArgs(partialArgs, partialHolders, args) {
var holdersLength = partialHolders.length,
argsIndex = -1,
argsLength = nativeMax(args.length - holdersLength, 0),
leftIndex = -1,
leftLength = partialArgs.length,
result = Array(argsLength + leftLength);
while (++leftIndex < leftLength) {
result[leftIndex] = partialArgs[leftIndex];
}
while (++argsIndex < holdersLength) {
result[partialHolders[argsIndex]] = args[argsIndex];
}
while (argsLength--) {
result[leftIndex++] = args[argsIndex++];
}
return result;
}
/**
* Creates a function that aggregates a collection, creating an object or
* array composed from the results of running each element in the collection
* through a callback. The given setter function sets the keys and values of
* the composed object or array.
*
* @private
* @param {Function} setter The setter function.
* @param {boolean} [retArray=false] A flag to indicate that the aggregator
* function should return an array.
* @returns {Function} Returns the new aggregator function.
*/
function createAggregator(setter, retArray) {
return function(collection, callback, thisArg) {
var result = retArray ? [[], []] : {};
callback = createCallback(callback, thisArg, 3);
var index = -1,
length = collection ? collection.length : 0;
if (typeof length == 'number' && length > -1 && length <= maxSafeInteger) {
while (++index < length) {
var value = collection[index];
setter(result, value, callback(value, index, collection), collection);
}
} else {
baseEach(collection, function(value, key, collection) {
setter(result, value, callback(value, key, collection), collection);
});
}
return result;
};
}
/**
* Creates a function that 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 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 {number} [arity] The arity of `func`.
* @param {*} [thisArg] The `this` binding of `func`.
* @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 {Array} [partialHolders] An array of `partialArgs` placeholder indexes.
* @param {Array} [partialRightHolders] An array of `partialRightArgs` placeholder indexes.
* @returns {Function} Returns the new function.
*/
function createWrapper(func, bitmask, arity, thisArg, partialArgs, partialRightArgs, partialHolders, partialRightHolders) {
var isBind = bitmask & BIND_FLAG,
isBindKey = bitmask & BIND_KEY_FLAG,
isPartial = bitmask & PARTIAL_FLAG,
isPartialRight = bitmask & PARTIAL_RIGHT_FLAG;
if (!isFunction(func)) {
throw new TypeError;
}
if (isPartial && !partialArgs.length) {
bitmask &= ~PARTIAL_FLAG;
isPartial = partialArgs = false;
}
if (isPartial) {
partialHolders = getHolders(partialArgs);
}
// fast path for `_.bind`
var data = [func, bitmask, arity, thisArg, partialArgs, partialRightArgs, partialHolders, partialRightHolders];
return baseCreateWrapper(data);
}
/**
* Finds the indexes of all placeholder elements in `array`.
*
* @private
* @param {Array} array The array to inspect.
* @returns {Array} Returns the new array of placeholder indexes.
*/
function getHolders(array) {
var index = -1,
length = array.length,
result = [];
while (++index < length) {
if (array[index] === lodash) {
result.push(index);
}
}
return result;
}
/**
* Gets the appropriate "indexOf" function. If the `_.indexOf` method is
* customized this function 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;
}
/**
* Checks if `value` is a native function.
*
* @private
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if `value` is a native function, else `false`.
*/
function isNative(value) {
return typeof value == 'function' && reNative.test(fnToString.call(value));
}
/**
* A fallback implementation of `Object.keys` which creates an array of the
* own enumerable property names of `object`.
*
* @private
* @param {Object} object The object to inspect.
* @returns {Array} Returns the array of property names.
*/
function shimKeys(object) {
var index = -1,
props = keysIn(object),
length = props.length,
result = [];
while (++index < length) {
var key = props[index];
if (hasOwnProperty.call(object, key)) {
result.push(key);
}
}
return result;
}
/*--------------------------------------------------------------------------*/
/**
* 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 the 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,
resIndex = 0,
result = [];
while (++index < length) {
var value = array[index];
if (value) {
result[resIndex++] = 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 the new array of filtered values.
* @example
*
* _.difference([1, 2, 3], [5, 2, 10]);
* // => [1, 3]
*/
function difference(array) {
return baseDifference(array, baseFlatten(arguments, true, true, 1));
}
/**
* Creates a slice of `array` with `n` elements dropped from the beginning.
*
* @static
* @memberOf _
* @type Function
* @category Arrays
* @param {Array} array The array to query.
* @param {number} [n=1] The number of elements to drop.
* @returns {Array} Returns the slice of `array`.
* @example
*
* _.drop([1, 2, 3], 1);
* // => [2, 3]
*
* _.drop([1, 2, 3], 2);
* // => [3]
*
* _.drop([1, 2, 3], 5);
* // => []
*
* _.drop([1, 2, 3], 0);
* // => [1, 2, 3]
*/
var drop = rest;
/**
* This method is like `_.find` except that it returns the index of the first
* element the predicate returns truthy for, instead of the element itself.
*
* If a property name is provided for `predicate` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `predicate` 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 {Function|Object|string} [predicate=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 `predicate`.
* @returns {number} Returns the index of the found element, else `-1`.
* @example
*
* var characters = [
* { 'name': 'barney', 'age': 36 },
* { 'name': 'fred', 'age': 40, 'blocked': true },
* { 'name': 'pebbles', 'age': 1 }
* ];
*
* _.findIndex(characters, function(chr) {
* return chr.age < 20;
* });
* // => 2
*
* // using "_.where" callback shorthand
* _.findIndex(characters, { 'age': 36 });
* // => 0
*
* // using "_.pluck" callback shorthand
* _.findIndex(characters, 'blocked');
* // => 1
*/
function findIndex(array, predicate, thisArg) {
var index = -1,
length = array ? array.length : 0;
predicate = createCallback(predicate, thisArg, 3);
while (++index < length) {
if (predicate(array[index], index, array)) {
return index;
}
}
return -1;
}
/**
* Gets the first element of `array`.
*
* @static
* @memberOf _
* @alias head
* @category Arrays
* @param {Array} array The array to query.
* @returns {*} Returns the first element of `array`.
* @example
*
* _.first([1, 2, 3]);
* // => 1
*
* _.first([]);
* // => undefined
*/
function first(array, n, guard) {
if (n == null || guard) {
return array ? array[0] : undefined;
}
return slice(array, 0, n < 0 ? 0 : n);
}
/**
* Flattens a nested array (the nesting can be to any depth). If `isShallow`
* is truthy, 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] 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 the new flattened array.
* @example
*
* _.flatten([1, [2], [3, [[4]]]]);
* // => [1, 2, 3, 4];
*
* // using `isShallow`
* _.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, guard) {
var length = array ? array.length : 0;
if (!length) {
return [];
}
var type = typeof isShallow;
if ((type == 'number' || type == 'string') && guard && guard[isShallow] === array) {
isShallow = false;
}
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, else `-1`.
* @example
*
* _.indexOf([1, 2, 3, 1, 2, 3], 2);
* // => 1
*
* // using `fromIndex`
* _.indexOf([1, 2, 3, 1, 2, 3], 2, 3);
* // => 4
*
* // performing a binary search
* _.indexOf([1, 1, 2, 2, 3, 3], 2, true);
* // => 2
*/
function indexOf(array, value, fromIndex) {
var length = array ? array.length : 0;
if (typeof fromIndex == 'number') {
fromIndex = fromIndex < 0 ? nativeMax(0, length + fromIndex) : (fromIndex || 0);
} else if (fromIndex) {
var index = sortedIndex(array, value);
return (length && array[index] === value) ? index : -1;
}
return baseIndexOf(array, value, fromIndex);
}
/**
* Gets all but the last element of `array`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to query.
* @returns {Array} Returns the slice of `array`.
* @example
*
* _.initial([1, 2, 3]);
* // => [1, 2]
*/
function initial(array, n, guard) {
var length = array ? array.length : 0;
n = length - ((n == null || guard) ? 1 : n);
return slice(array, 0, n < 0 ? 0 : n);
}
/**
* 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 the new 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);
}
}
argsLength = args.length
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 of `array`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to query.
* @returns {*} Returns the last element of `array`.
* @example
*
* _.last([1, 2, 3]);
* // => 3
*/
function last(array, n, guard) {
var length = array ? array.length : 0;
if (n == null || guard) {
return array ? array[length - 1] : undefined;
}
n = length - n;
return slice(array, n < 0 ? 0 : 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.
*
* @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, else `-1`.
* @example
*
* _.lastIndexOf([1, 2, 3, 1, 2, 3], 2);
* // => 4
*
* // using `fromIndex`
* _.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') {
fromIndex |= 0;
index = (fromIndex < 0 ? nativeMax(0, index + fromIndex) : nativeMin(fromIndex, index - 1)) + 1;
}
while (index--) {
if (array[index] === value) {
return index;
}
}
return -1;
}
/**
* Gets all but the first element of `array`.
*
* @static
* @memberOf _
* @alias tail
* @category Arrays
* @param {Array} array The array to query.
* @returns {Array} Returns the slice of `array`.
* @example
*
* _.rest([1, 2, 3]);
* // => [2, 3]
*/
function rest(array, n, guard) {
if (n == null || guard) {
n = 1;
} else {
n = n < 0 ? 0 : n;
}
return slice(array, n);
}
/**
* Slices `array` 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.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to slice.
* @param {number} [start=0] The start index.
* @param {number} [end=array.length] The end index.
* @returns {Array} Returns the slice of `array`.
*/
function slice(array, start, end) {
var index = -1,
length = array ? array.length : 0;
start = +start || 0;
if (start < 0) {
start = nativeMax(length + start, 0);
} else if (start > length) {
start = length;
}
end = typeof end == 'undefined' ? length : (+end || 0);
if (end < 0) {
end = nativeMax(length + end, 0);
} else if (end > length) {
end = length;
}
length = start > end ? 0 : (end - start);
var result = Array(length);
while (++index < length) {
result[index] = array[start + index];
}
return result;
}
/**
* 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
*
* var dict = {
* 'wordToNumber': { 'twenty': 20, 'thirty': 30, 'fourty': 40, 'fifty': 50 }
* };
*
* // using `callback`
* _.sortedIndex(['twenty', 'thirty', 'fifty'], 'fourty', function(word) {
* return dict.wordToNumber[word];
* });
* // => 2
*
* // using `callback` with `thisArg`
* _.sortedIndex(['twenty', 'thirty', 'fifty'], 'fourty', function(word) {
* return this.wordToNumber[word];
* }, dict);
* // => 2
*
* // using "_.pluck" callback shorthand
* _.sortedIndex([{ 'x': 20 }, { 'x': 30 }, { 'x': 50 }], { 'x': 40 }, 'x');
* // => 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 a slice of `array` with `n` elements taken from the beginning.
*
* @static
* @memberOf _
* @type Function
* @category Arrays
* @param {Array} array The array to query.
* @param {number} [n=1] The number of elements to take.
* @returns {Array} Returns the slice of `array`.
* @example
*
* _.take([1, 2, 3], 1);
* // => [1]
*
* _.take([1, 2, 3], 2);
* // => [1, 2]
*
* _.take([1, 2, 3], 5);
* // => [1, 2, 3]
*
* _.take([1, 2, 3], 0);
* // => []
*/
var take = first;
/**
* 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 the new 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] 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 the new duplicate-value-free array.
* @example
*
* _.uniq([1, 2, 1, 3, 1]);
* // => [1, 2, 3]
*
* // using `isSorted`
* _.uniq([1, 1, 2, 2, 3], true);
* // => [1, 2, 3]
*
* // using `callback`
* _.uniq(['A', 'b', 'C', 'a', 'B', 'c'], function(letter) { return letter.toLowerCase(); });
* // => ['A', 'b', 'C']
*
* // using `callback` with `thisArg`
* _.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) {
var length = array ? array.length : 0;
if (!length) {
return [];
}
// juggle arguments
var type = typeof isSorted;
if (type != 'boolean' && isSorted != null) {
thisArg = callback;
callback = isSorted;
isSorted = false;
// enables use as a callback for functions like `_.map`
if ((type == 'number' || type == 'string') && thisArg && thisArg[callback] === array) {
callback = null;
}
}
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 the new array of filtered values.
* @example
*
* _.without([1, 2, 1, 0, 3, 1, 4], 0, 1);
* // => [2, 3, 4]
*/
function without() {
return baseDifference(arguments[0], 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. If a zipped value is provided its corresponding
* unzipped value will be returned.
*
* @static
* @memberOf _
* @alias unzip
* @category Arrays
* @param {...Array} [array] The arrays to process.
* @returns {Array} Returns the array of grouped elements.
* @example
*
* _.zip(['fred', 'barney'], [30, 40], [true, false]);
* // => [['fred', 30, true], ['barney', 40, false]]
*
* _.unzip([['fred', 30, true], ['barney', 40, false]]);
* // => [['fred', 'barney'], [30, 40], [true, 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 the new object.
* @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 `lodash` object that wraps `value` with explicit method
* chaining enabled.
*
* @static
* @memberOf _
* @category Chaining
* @param {*} value The value to wrap.
* @returns {Object} Returns the new wrapper object.
* @example
*
* var characters = [
* { 'name': 'barney', 'age': 36 },
* { 'name': 'fred', 'age': 40 },
* { 'name': 'pebbles', 'age': 1 }
* ];
*
* var youngest = _.chain(characters)
* .sortBy('age')
* .map(function(chr) { return chr.name + ' is ' + chr.age; })
* .first()
* .value();
* // => 'pebbles is 1'
*/
function chain(value) {
value = new lodashWrapper(value);
value.__chain__ = true;
return value;
}
/**
* This method invokes `interceptor` and returns `value`. The interceptor is
* bound to `thisArg` and invoked with one argument; (value). The purpose of
* this method is to "tap into" a method chain in order to perform operations
* on intermediate results within the chain.
*
* @static
* @memberOf _
* @category Chaining
* @param {*} value The value to provide to `interceptor`.
* @param {Function} interceptor The function to invoke.
* @param {*} [thisArg] The `this` binding of `interceptor`.
* @returns {*} Returns `value`.
* @example
*
* _([1, 2, 3, 4])
* .tap(function(array) { array.pop(); })
* .reverse()
* .value();
* // => [3, 2, 1]
*/
function tap(value, interceptor) {
interceptor(value);
return value;
}
/**
* Enables explicit method chaining on the wrapper object.
*
* @name chain
* @memberOf _
* @category Chaining
* @returns {*} Returns the wrapper object.
* @example
*
* var characters = [
* { 'name': 'barney', 'age': 36 },
* { 'name': 'fred', 'age': 40 }
* ];
*
* // without explicit chaining
* _(characters).first();
* // => { 'name': 'barney', 'age': 36 }
*
* // with explicit chaining
* _(characters).chain()
* .first()
* .pick('age')
* .value();
* // => { 'age': 36 }
*/
function wrapperChain() {
this.__chain__ = true;
return this;
}
/**
* Extracts the wrapped value.
*
* @name valueOf
* @memberOf _
* @alias value
* @category Chaining
* @returns {*} Returns the wrapped value.
* @example
*
* _([1, 2, 3]).valueOf();
* // => [1, 2, 3]
*/
function wrapperValueOf() {
return this.__wrapped__;
}
/*--------------------------------------------------------------------------*/
/**
* 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 search.
* @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 (typeof length == 'number' && length > -1 && length <= maxSafeInteger) {
return indexOf(collection, target) > -1;
}
baseEach(collection, function(value) {
return (result = value === target) && breakIndicator;
});
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 predicate returns truthy for **all** elements of a collection.
* The predicate is bound to `thisArg` and invoked with three arguments;
* (value, index|key, collection).
*
* If a property name is provided for `predicate` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `predicate` 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} [predicate=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 `predicate`.
* @returns {boolean} Returns `true` if all elements passed the predicate 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, predicate, thisArg) {
var result = true;
predicate = createCallback(predicate, thisArg, 3);
var index = -1,
length = collection ? collection.length : 0;
if (typeof length == 'number' && length > -1 && length <= maxSafeInteger) {
while (++index < length) {
if (!predicate(collection[index], index, collection)) {
return false;
}
}
} else {
baseEach(collection, function(value, index, collection) {
return !(result = !!predicate(value, index, collection)) && breakIndicator;
});
}
return result;
}
/**
* Iterates over elements of a collection returning an array of all elements
* the predicate returns truthy for. The predicate is bound to `thisArg` and
* invoked with three arguments; (value, index|key, collection).
*
* If a property name is provided for `predicate` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `predicate` 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} [predicate=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 `predicate`.
* @returns {Array} Returns the new filtered array.
* @example
*
* var evens = _.filter([1, 2, 3, 4], function(num) { return num % 2 == 0; });
* // => [2, 4]
*
* var characters = [
* { 'name': 'barney', 'age': 36 },
* { '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 }]
*/
function filter(collection, predicate, thisArg) {
var result = [];
predicate = createCallback(predicate, thisArg, 3);
var index = -1,
length = collection ? collection.length : 0;
if (typeof length == 'number' && length > -1 && length <= maxSafeInteger) {
while (++index < length) {
var value = collection[index];
if (predicate(value, index, collection)) {
result.push(value);
}
}
} else {
baseEach(collection, function(value, index, collection) {
if (predicate(value, index, collection)) {
result.push(value);
}
});
}
return result;
}
/**
* Iterates over elements of a collection, returning the first element that
* the predicate returns truthy for. The predicate is bound to `thisArg` and
* invoked with three arguments; (value, index|key, collection).
*
* If a property name is provided for `predicate` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `predicate` 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 search.
* @param {Function|Object|string} [predicate=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 `predicate`.
* @returns {*} Returns the found element, else `undefined`.
* @example
*
* var characters = [
* { 'name': 'barney', 'age': 36 },
* { 'name': 'fred', 'age': 40, 'blocked': true },
* { 'name': 'pebbles', 'age': 1 }
* ];
*
* _.find(characters, function(chr) {
* return chr.age < 40;
* });
* // => { 'name': 'barney', 'age': 36 }
*
* // using "_.where" callback shorthand
* _.find(characters, { 'age': 1 });
* // => { 'name': 'pebbles', 'age': 1 }
*
* // using "_.pluck" callback shorthand
* _.find(characters, 'blocked');
* // => { 'name': 'fred', 'age': 40, 'blocked': true }
*/
function find(collection, predicate, thisArg) {
var length = collection ? collection.length : 0;
if (typeof length == 'number' && length > -1 && length <= maxSafeInteger) {
var index = findIndex(collection, predicate, thisArg);
return index > -1 ? collection[index] : undefined;
}
predicate = createCallback(predicate, thisArg, 3);
return baseFind(collection, predicate, baseEach);
}
/**
* 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' && length > -1 && length <= maxSafeInteger) {
while (++index < length) {
if (callback(collection[index], index, collection) === breakIndicator) {
break;
}
}
} else {
baseEach(collection, callback);
}
return collection;
}
/**
* 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) {
if (hasOwnProperty.call(result, key)) {
result[key].push(value);
} else {
result[key] = [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 keyData = [
* { 'dir': 'left', 'code': 97 },
* { 'dir': 'right', 'code': 100 }
* ];
*
* _.indexBy(keyData, 'dir');
* // => { 'left': { 'dir': 'left', 'code': 97 }, 'right': { 'dir': 'right', 'code': 100 } }
*
* _.indexBy(keyData, function(object) { return String.fromCharCode(object.code); });
* // => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } }
*
* _.indexBy(keyData, function(object) { return this.fromCharCode(object.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 {...*} [args] Arguments to invoke the method with.
* @returns {Array} Returns the array of results.
* @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,
result = Array(length < 0 ? 0 : length >>> 0);
baseEach(collection, function(value) {
var func = isFunc ? methodName : (value != null && value[methodName]);
result[++index] = func ? func.apply(value, args) : undefined;
});
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 the new mapped array.
* @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' && length > -1 && length <= maxSafeInteger) {
var result = Array(length);
while (++index < length) {
result[index] = callback(collection[index], index, collection);
}
} else {
result = [];
baseEach(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] 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,
type = typeof callback;
// enables use as a callback for functions like `_.map`
if ((type == 'number' || type == 'string') && thisArg && thisArg[callback] === collection) {
callback = null;
}
var index = -1,
length = collection ? collection.length : 0;
if (callback == null && typeof length == 'number' && length > -1 && length <= maxSafeInteger) {
while (++index < length) {
var value = collection[index];
if (value > result) {
result = value;
}
}
} else {
callback = createCallback(callback, thisArg, 3);
baseEach(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] 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,
type = typeof callback;
// enables use as a callback for functions like `_.map`
if ((type == 'number' || type == 'string') && thisArg && thisArg[callback] === collection) {
callback = null;
}
var index = -1,
length = collection ? collection.length : 0;
if (callback == null && typeof length == 'number' && length > -1 && length <= maxSafeInteger) {
while (++index < length) {
var value = collection[index];
if (value < result) {
result = value;
}
}
} else {
callback = createCallback(callback, thisArg, 3);
baseEach(collection, function(value, index, collection) {
var current = callback(value, index, collection);
if (current < computed) {
computed = current;
result = value;
}
});
}
return result;
}
/**
* Creates an array of elements split into two groups, the first of which
* contains elements the predicate returns truthy for, while the second of which
* contains elements the predicate returns falsey for. The predicate is bound
* to `thisArg` and invoked with three arguments; (value, index|key, collection).
*
* If a property name is provided for `predicate` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `predicate` 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} [predicate=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 `predicate`.
* @returns {Array} Returns the array of grouped elements.
* @example
*
* _.partition([1, 2, 3], function(num) { return num % 2; });
* // => [[1, 3], [2]]
*
* _.partition([1.2, 2.3, 3.4], function(num) { return this.floor(num) % 2; }, Math);
* // => [[1, 3], [2]]
*
* var characters = [
* { 'name': 'barney', 'age': 36 },
* { 'name': 'fred', 'age': 40, 'blocked': true },
* { 'name': 'pebbles', 'age': 1 }
* ];
*
* // using "_.where" callback shorthand
* _.map(_.partition(characters, { 'age': 1 }), function(array) { return _.pluck(array, 'name'); });
* // => [['pebbles'], ['barney', 'fred']]
*
* // using "_.pluck" callback shorthand
* _.map(_.partition(characters, 'blocked'), function(array) { return _.pluck(array, 'name'); });
* // => [['fred'], ['barney', 'pebbles']]
*/
var partition = createAggregator(function(result, value, key) {
result[key ? 0 : 1].push(value);
}, true);
/**
* 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} key The name of the property to pluck.
* @returns {Array} Returns the 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) {
var noaccum = arguments.length < 3;
callback = createCallback(callback, thisArg, 4);
var index = -1,
length = collection ? collection.length : 0;
if (typeof length == 'number' && length > -1 && length <= maxSafeInteger) {
if (noaccum && length) {
accumulator = collection[++index];
}
while (++index < length) {
accumulator = callback(accumulator, collection[index], index, collection);
}
} else {
baseEach(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);
baseEachRight(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
* the predicate does **not** return truthy for.
*
* If a property name is provided for `predicate` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `predicate` 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} [predicate=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 `predicate`.
* @returns {Array} Returns the new filtered array.
* @example
*
* var odds = _.reject([1, 2, 3, 4], function(num) { return num % 2 == 0; });
* // => [1, 3]
*
* var characters = [
* { 'name': 'barney', 'age': 36 },
* { 'name': 'fred', 'age': 40, 'blocked': true }
* ];
*
* // using "_.pluck" callback shorthand
* _.reject(characters, 'blocked');
* // => [{ 'name': 'barney', 'age': 36 }]
*
* // using "_.where" callback shorthand
* _.reject(characters, { 'age': 36 });
* // => [{ 'name': 'fred', 'age': 40, 'blocked': true }]
*/
function reject(collection, predicate, thisArg) {
predicate = createCallback(predicate, thisArg, 3);
return filter(collection, negate(predicate));
}
/**
* 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] Enables use as a callback for functions like `_.map`.
* @returns {*} Returns the random sample(s).
* @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) {
var length = collection ? collection.length : 0;
return length > 0 ? collection[baseRandom(0, 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 [Wikipedia](http://en.wikipedia.org/wiki/Fisher-Yates_shuffle)
* for more details.
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|string} collection The collection to shuffle.
* @returns {Array} Returns the new shuffled array.
* @example
*
* _.shuffle([1, 2, 3, 4]);
* // => [4, 1, 3, 2]
*/
function shuffle(collection) {
var index = -1,
length = collection && collection.length,
result = Array(length < 0 ? 0 : length >>> 0);
baseEach(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 > -1 && length <= maxSafeInteger)
? length
: keys(collection).length;
}
/**
* Checks if the predicate returns truthy 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 predicate is bound to `thisArg` and invoked
* with three arguments; (value, index|key, collection).
*
* If a property name is provided for `predicate` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `predicate` 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} [predicate=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 `predicate`.
* @returns {boolean} Returns `true` if any element passed the predicate check,
* else `false`.
* @example
*
* _.some([null, 0, 'yes', false], Boolean);
* // => true
*
* var characters = [
* { 'name': 'barney', 'age': 36 },
* { '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, predicate, thisArg) {
var result;
predicate = createCallback(predicate, thisArg, 3);
var index = -1,
length = collection ? collection.length : 0;
if (typeof length == 'number' && length > -1 && length <= maxSafeInteger) {
while (++index < length) {
if (predicate(collection[index], index, collection)) {
return true;
}
}
} else {
baseEach(collection, function(value, index, collection) {
return (result = predicate(value, index, collection)) && breakIndicator;
});
}
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 the new sorted array.
* @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,
result = Array(length < 0 ? 0 : length >>> 0);
callback = createCallback(callback, thisArg, 3);
baseEach(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 `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 between each element in `collection` and the
* source 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} source The object of property values to filter by.
* @returns {Array} Returns the new filtered array.
* @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'] }]
*/
var where = filter;
/*--------------------------------------------------------------------------*/
/**
* 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 invokes `func` with the `this` binding of `thisArg`
* and prepends any additional `bind` arguments to those provided to the bound
* function.
*
* Note: Unlike native `Function#bind` this method does not set the `length`
* property of bound functions.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to bind.
* @param {*} [thisArg] The `this` binding of `func`.
* @param {...*} [args] 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 < 3
? createWrapper(func, BIND_FLAG, null, thisArg)
: createWrapper(func, BIND_FLAG | PARTIAL_FLAG, null, thisArg, slice(arguments, 2));
}
/**
* 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.
*
* Note: This method does not set the `length` property of bound functions.
*
* @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], BIND_FLAG, 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,
funcsLength = funcs.length,
length = funcsLength;
while (length--) {
if (!isFunction(funcs[length])) {
throw new TypeError;
}
}
return function() {
var length = funcsLength - 1,
result = funcs[length].apply(this, arguments);
while (length--) {
result = funcs[length].call(this, result);
}
return result;
};
}
/**
* 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 = wait < 0 ? 0 : wait;
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 || remaining > wait) {
if (maxTimeoutId) {
clearTimeout(maxTimeoutId);
}
var isCalled = trailingCall;
maxTimeoutId = timeoutId = trailingCall = undefined;
if (isCalled) {
lastCalled = now();
result = func.apply(thisArg, args);
if (!timeoutId && !maxTimeoutId) {
args = thisArg = null;
}
}
} 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 || remaining > maxWait;
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 {...*} [args] 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 {...*} [args] 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] The function 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) : '_' + arguments[0];
return hasOwnProperty.call(cache, key)
? cache[key]
: (cache[key] = func.apply(this, arguments));
};
}
/**
* Creates a function that negates the result of `func`. The `func` function
* is executed with the `this` binding and arguments of the created function.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to negate.
* @returns {Function} Returns the new function.
* @example
*
* function isEven(num) {
* return num % 2 == 0;
* }
*
* _.filter([1, 2, 3, 4, 5, 6], _.negate(isEven));
* // => [1, 3, 5]
*/
function negate(func) {
if (!isFunction(func)) {
throw new TypeError;
}
return function() {
return !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 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.
*
* Note: This method does not set the `length` property of partially applied
* functions.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to partially apply arguments to.
* @param {...*} [args] 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, PARTIAL_FLAG, null, null, 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;
}
return debounce(func, wait, {
'leading': leading,
'maxWait': wait,
'trailing': trailing
});
}
/**
* 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, barney, & pebbles');
* // => 'fred, barney, & pebbles
'
*/
function wrap(value, wrapper) {
return createWrapper(wrapper, PARTIAL_FLAG, null, null, [value]);
}
/*--------------------------------------------------------------------------*/
/**
* 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 _
* @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;
* });
*
* defaults({ 'name': 'barney' }, { 'name': 'fred', 'employer': 'slate' });
* // => { 'name': 'barney', 'employer': 'slate' }
*/
function assign(object, source, guard) {
if (!object) {
return object;
}
var args = arguments,
argsIndex = 0,
argsLength = args.length,
type = typeof guard;
if ((type == 'number' || type == 'string') && args[3] && args[3][guard] === source) {
argsLength = 2;
}
while (++argsIndex < argsLength) {
source = args[argsIndex];
for (var key in source) {
object[key] = source[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).
*
* Note: This method is loosely based on the structured clone algorithm. Functions
* and DOM nodes are **not** cloned. The enumerable properties of `arguments` objects and
* objects created by constructors other than `Object` are cloned to plain `Object` objects.
* See the [HTML5 specification](http://www.w3.org/TR/html5/infrastructure.html#internal-structured-cloning-algorithm)
* for more details.
*
* @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 _
* @category Objects
* @param {Object} object The destination object.
* @param {...Object} [source] The source objects.
* @param- {Object} [guard] Enables use as a callback for functions like `_.reduce`.
* @returns {Object} Returns the destination object.
* @example
*
* _.defaults({ 'name': 'barney' }, { 'name': 'fred', 'employer': 'slate' });
* // => { 'name': 'barney', 'employer': 'slate' }
*/
function defaults(object, source, guard) {
if (!object) {
return object;
}
var args = arguments,
argsIndex = 0,
argsLength = args.length,
type = typeof guard;
if ((type == 'number' || type == 'string') && args[3] && args[3][guard] === source) {
argsLength = 2;
}
while (++argsIndex < argsLength) {
source = args[argsIndex];
for (var key in source) {
if (typeof object[key] == 'undefined') {
object[key] = source[key];
}
}
}
return object;
}
/**
* 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 the new sorted array of property names.
* @example
*
* _.functions(_);
* // => ['all', 'any', 'bind', 'bindAll', 'clone', 'compact', 'compose', ...]
*/
function functions(object) {
var result = [];
baseForIn(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. If the given object contains duplicate values, subsequent values
* will overwrite property assignments of previous values unless `multiValue`
* is `true`.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The object to invert.
* @param {boolean} [multiValue=false] Allow multiple values per key.
* @returns {Object} Returns the new inverted object.
* @example
*
* _.invert({ 'first': 'fred', 'second': 'barney' });
* // => { 'fred': 'first', 'barney': 'second' }
*
* // without `multiValue`
* _.invert({ 'first': 'fred', 'second': 'barney', 'third': 'fred' });
* // => { 'fred': 'third', 'barney': 'second' }
*
* // with `multiValue`
* _.invert({ 'first': 'fred', 'second': 'barney', 'third': 'fred' }, true);
* // => { 'fred': ['first', 'third'], '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 an `arguments` object.
*
* @static
* @memberOf _
* @category Objects
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if `value` is an `arguments` object, else `false`.
* @example
*
* (function() { return _.isArguments(arguments); })();
* // => 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 environments 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 _
* @category Objects
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if `value` is an array, else `false`.
* @example
*
* _.isArray([1, 2, 3]);
* // => true
*
* (function() { return _.isArray(arguments); })();
* // => false
*/
var isArray = nativeIsArray || function(value) {
return value && typeof value == 'object' && typeof value.length == 'number' &&
toString.call(value) == arrayClass || false;
};
/**
* Checks if `value` is a boolean value.
*
* @static
* @memberOf _
* @category Objects
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if `value` is a boolean value, else `false`.
* @example
*
* _.isBoolean(false);
* // => true
*
* _.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 `value` is a date, else `false`.
* @example
*
* _.isDate(new Date);
* // => true
*
* _.isDate('Wed May 23 2012');
* // => false
*/
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 `value` is a DOM element, else `false`.
* @example
*
* _.isElement(document.body);
* // => true
*
* _.isElement('');
* // => false
*/
function isElement(value) {
return value && value.nodeType === 1 || false;
}
/**
* Checks if a collection is empty. A value is considered empty unless it is
* an array, array-like object, or string with a length greater than `0` or
* an object with own properties.
*
* @static
* @memberOf _
* @category Objects
* @param {Array|Object|string} value The value to inspect.
* @returns {boolean} Returns `true` if `value` is empty, else `false`.
* @example
*
* _.isEmpty(null);
* // => true
*
* _.isEmpty(true);
* // => true
*
* _.isEmpty(1);
* // => true
*
* _.isEmpty([1, 2, 3]);
* // => false
*
* _.isEmpty({ 'a': 1 });
* // => false
*/
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 method is not the same as native `isFinite` which will return
* `true` for booleans and empty strings. See the [ES5 spec](http://es5.github.io/#x15.1.2.5)
* for more details.
*
* @static
* @memberOf _
* @category Objects
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if `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 `value` is a function, else `false`.
* @example
*
* _.isFunction(_);
* // => true
*
* _.isFunction(/abc/);
* // => false
*/
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 `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
// https://code.google.com/p/v8/issues/detail?id=2291
var type = typeof value;
return value && (type == 'function' || type == 'object') || false;
}
/**
* Checks if `value` is `NaN`.
*
* Note: This method is not the same as native `isNaN` which will return `true`
* for `undefined` and other non-numeric values. See the [ES5 spec](http://es5.github.io/#x15.1.2.4)
* for more details.
*
* @static
* @memberOf _
* @category Objects
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if `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 `value` is `null`, else `false`.
* @example
*
* _.isNull(null);
* // => true
*
* _.isNull(void 0);
* // => false
*/
function isNull(value) {
return value === null;
}
/**
* Checks if `value` is a number.
*
* Note: `NaN` is considered a number. See the [ES5 spec](http://es5.github.io/#x8.5)
* for more details.
*
* @static
* @memberOf _
* @category Objects
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if `value` is a number, else `false`.
* @example
*
* _.isNumber(8.4);
* // => true
*
* _.isNumber(NaN);
* // => true
*
* _.isNumber('8.4');
* // => false
*/
function isNumber(value) {
var type = typeof value;
return type == 'number' ||
value && type == '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 `value` is a regular expression, else `false`.
* @example
*
* _.isRegExp(/abc/);
* // => true
*
* _.isRegExp('/abc/');
* // => false
*/
function isRegExp(value) {
var type = typeof value;
return value && (type == 'function' || type == 'object') &&
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 `value` is a string, else `false`.
* @example
*
* _.isString('abc');
* // => true
*
* _.isString(1);
* // => false
*/
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 `value` is `undefined`, else `false`.
* @example
*
* _.isUndefined(void 0);
* // => true
*
* _.isUndefined(null);
* // => false
*/
function isUndefined(value) {
return typeof value == 'undefined';
}
/**
* Creates an array of the own enumerable property names of `object`.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The object to inspect.
* @returns {Array} Returns the array of property names.
* @example
*
* function Shape() {
* this.x = 0;
* this.y = 0;
* }
*
* Shape.prototype.z = 0;
*
* _.keys(new Shape);
* // => ['x', 'y'] (property order is not guaranteed across environments)
*/
var keys = !nativeKeys ? shimKeys : function(object) {
return isObject(object) ? nativeKeys(object) : [];
};
/**
* Creates an array of the own and inherited enumerable property names of `object`.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The object to inspect.
* @returns {Array} Returns the array of property names.
* @example
*
* function Shape() {
* this.x = 0;
* this.y = 0;
* }
*
* Shape.prototype.z = 0;
*
* _.keysIn(new Shape);
* // => ['x', 'y', 'z'] (property order is not guaranteed across environments)
*/
function keysIn(object) {
var result = [];
if (!isObject(object)) {
return result;
}
for (var key in object) {
result.push(key);
}
return result;
}
/**
* 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 predicate is provided it will be executed for each
* property of `object` omitting the properties the predicate returns truthy
* for. The predicate 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[]} [predicate] The function called per
* iteration or property names to omit, specified as individual property
* names or arrays of property names.
* @param {*} [thisArg] The `this` binding of `predicate`.
* @returns {Object} Returns the new object.
* @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 omitProps = baseFlatten(arguments, true, false, 1),
length = omitProps.length;
while (length--) {
omitProps[length] = String(omitProps[length]);
}
return pick(object, baseDifference(keysIn(object), omitProps));
}
/**
* Creates a two dimensional array of a given object's key-value pairs,
* i.e. `[[key1, value1], [key2, value2]]`.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The object to inspect.
* @returns {Array} Returns new array of key-value pairs.
* @example
*
* _.pairs({ '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 predicate is provided it will be executed for each
* property of `object` picking the properties the predicate returns truthy
* for. The predicate 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[]} [predicate] 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 `predicate`.
* @returns {Object} Returns the new object.
* @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 of the own enumerable property values of `object`.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The object to inspect.
* @returns {Array} Returns the array of property values.
* @example
*
* function Shape(x, y) {
* this.x = x;
* this.y = y;
* }
*
* Shape.prototype.z = 0;
*
* _.values(new Shape(2, 1));
* // => [2, 1] (property order is not guaranteed across environments)
*/
function values(object) {
return baseValues(object, keys);
}
/*--------------------------------------------------------------------------*/
/**
* Converts the characters "&", "<", ">", '"', and "'" in `string` to
* their corresponding HTML entities.
*
* Note: No other characters are escaped. To escape additional characters
* use a third-party library like [_he_](http://mths.be/he).
*
* When working with HTML you should always quote attribute values to reduce
* XSS vectors. See [Ryan Grove's article](http://wonko.com/post/html-escaping)
* for more details.
*
* @static
* @memberOf _
* @category Strings
* @param {string} [string=''] The string to escape.
* @returns {string} Returns the escaped string.
* @example
*
* _.escape('fred, barney, & pebbles');
* // => 'fred, barney, & pebbles'
*/
function escape(string) {
return string == null ? '' : String(string).replace(reUnescapedHtml, escapeHtmlChar);
}
/**
* Escapes the RegExp special characters "\", "^", "$", ".", "|", "?", "*",
* "+", "(", ")", "[", "]", "{" and "}" in `string`.
*
* @static
* @memberOf _
* @category Strings
* @param {string} [string=''] The string to escape.
* @returns {string} Returns the escaped string.
* @example
*
* _.escapeRegExp('[lodash](http://lodash.com)');
* // => '\[lodash\]\(http://lodash\.com\)'
*/
function escapeRegExp(string) {
return string == null ? '' : String(string).replace(reRegExpChars, '\\$&');
}
/**
* Creates a compiled template function that can interpolate data properties
* in "interpolate" delimiters, HTML-escaped interpolated data properties in
* "escape" delimiters, and execute JavaScript in "evaluate" delimiters. If
* a data object is provided the interpolated template string will be returned.
* Data properties may be accessed as free variables in the template. If a
* settings object is provided it will override `_.templateSettings` for the
* template.
*
* Note: In the development build, `_.template` utilizes sourceURLs for easier debugging.
* See the [HTML5 Rocks article on sourcemaps](http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl)
* for more details.
*
* For more information on precompiling templates see
* [Lo-Dash's custom builds documentation](http://lodash.com/custom-builds).
*
* For more information on Chrome extension sandboxes see
* [Chrome's extensions documentation](http://developer.chrome.com/stable/extensions/sandboxingEval.html).
*
* @static
* @memberOf _
* @category Strings
* @param {string} [string=''] The template string.
* @param {Object} [data] The data object used to populate the template string.
* @param {Object} [options] The options object.
* @param {RegExp} [options.escape] The HTML "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} [options.sourceURL] The sourceURL of the template's compiled source.
* @param {string} [options.variable] The data object variable name.
* @returns {Function|string} Returns the interpolated string if a data object
* is provided, else the compiled template function.
* @example
*
* // using the "interpolate" delimiter to create a compiled template
* var compiled = _.template('hello <%= name %>');
* compiled({ 'name': 'fred' });
* // => 'hello fred'
*
* // using the HTML "escape" delimiter to escape data property values
* _.template('<%- value %>', { 'value': '