/**
* @license
* Lo-Dash 1.3.1 (Custom Build)
* Build: `lodash underscore exports="amd,commonjs,global,node" -o ./dist/lodash.underscore.js`
* Copyright 2012-2013 The Dojo Foundation
* Based on Underscore.js 1.4.4
* Copyright 2009-2013 Jeremy Ashkenas, DocumentCloud Inc.
* Available under MIT license
*/
;(function(window) {
/** Used as a safe reference for `undefined` in pre ES5 environments */
var undefined;
/** Used to generate unique IDs */
var idCounter = 0;
/** Used internally to indicate various things */
var indicatorObject = {};
/** Used to prefix keys to avoid issues with `__proto__` and properties on `Object.prototype` */
var keyPrefix = +new Date + '';
/** Used to match HTML entities */
var reEscapedHtml = /&(?:amp|lt|gt|quot|#39);/g;
/** Used to match "interpolate" template delimiters */
var reInterpolate = /<%=([\s\S]+?)%>/g;
/** Used to ensure capturing order of template delimiters */
var reNoMatch = /($^)/;
/** Used to match HTML characters */
var reUnescapedHtml = /[&<>"']/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 determine if values are of the language type Object */
var objectTypes = {
'boolean': false,
'function': true,
'object': true,
'number': false,
'string': false,
'undefined': false
};
/** Used to escape characters for inclusion in compiled string literals */
var stringEscapes = {
'\\': '\\',
"'": "'",
'\n': 'n',
'\r': 'r',
'\t': 't',
'\u2028': 'u2028',
'\u2029': 'u2029'
};
/** Detect free variable `exports` */
var freeExports = objectTypes[typeof exports] && exports;
/** Detect free variable `module` */
var freeModule = objectTypes[typeof module] && module && module.exports == freeExports && module;
/** Detect free variable `global`, from Node.js or Browserified code, and use it as `window` */
var freeGlobal = objectTypes[typeof global] && global;
if (freeGlobal && (freeGlobal.global === freeGlobal || freeGlobal.window === freeGlobal)) {
window = freeGlobal;
}
/*--------------------------------------------------------------------------*/
/**
* A basic implementation of `_.indexOf` without support for binary searches
* or `fromIndex` constraints.
*
* @private
* @param {Array} array The array to search.
* @param {Mixed} value The value to search for.
* @param {Number} [fromIndex=0] The index to search from.
* @returns {Number} Returns the index of the matched value or `-1`.
*/
function basicIndexOf(array, value, fromIndex) {
var index = (fromIndex || 0) - 1,
length = array.length;
while (++index < length) {
if (array[index] === value) {
return index;
}
}
return -1;
}
/**
* Used by `sortBy` to compare transformed `collection` values, stable sorting
* them in ascending order.
*
* @private
* @param {Object} a The object to compare to `b`.
* @param {Object} b The object to compare to `a`.
* @returns {Number} Returns the sort order indicator of `1` or `-1`.
*/
function compareAscending(a, b) {
var ai = a.index,
bi = b.index;
a = a.criteria;
b = b.criteria;
// ensure a stable sort in V8 and other engines
// http://code.google.com/p/v8/issues/detail?id=90
if (a !== b) {
if (a > b || typeof a == 'undefined') {
return 1;
}
if (a < b || typeof b == 'undefined') {
return -1;
}
}
return ai < bi ? -1 : 1;
}
/**
* Used by `template` to escape characters for inclusion in compiled
* string literals.
*
* @private
* @param {String} match The matched character to escape.
* @returns {String} Returns the escaped character.
*/
function escapeStringChar(match) {
return '\\' + stringEscapes[match];
}
/**
* A no-operation function.
*
* @private
*/
function noop() {
// no operation performed
}
/*--------------------------------------------------------------------------*/
/**
* Used for `Array` method references.
*
* Normally `Array.prototype` would suffice, however, using an array literal
* avoids issues in Narwhal.
*/
var arrayRef = [];
/** Used for native method references */
var objectProto = Object.prototype;
/** Used to restore the original `_` reference in `noConflict` */
var oldDash = window._;
/** Used to detect if a method is native */
var reNative = RegExp('^' +
String(objectProto.valueOf)
.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')
.replace(/valueOf|for [^\]]+/g, '.+?') + '$'
);
/** Native method shortcuts */
var ceil = Math.ceil,
concat = arrayRef.concat,
floor = Math.floor,
hasOwnProperty = objectProto.hasOwnProperty,
push = arrayRef.push,
toString = objectProto.toString;
/* Native method shortcuts for methods with the same name as other `lodash` methods */
var nativeBind = reNative.test(nativeBind = toString.bind) && nativeBind,
nativeCreate = reNative.test(nativeCreate = Object.create) && nativeCreate,
nativeIsArray = reNative.test(nativeIsArray = Array.isArray) && nativeIsArray,
nativeIsFinite = window.isFinite,
nativeIsNaN = window.isNaN,
nativeKeys = reNative.test(nativeKeys = Object.keys) && nativeKeys,
nativeMax = Math.max,
nativeMin = Math.min,
nativeRandom = Math.random,
nativeSlice = arrayRef.slice;
/** Detect various environments */
var isIeOpera = reNative.test(window.attachEvent),
isV8 = nativeBind && !/\n|true/.test(nativeBind + isIeOpera);
/*--------------------------------------------------------------------------*/
/**
* Creates a `lodash` object, which wraps the given `value`, to enable method
* chaining.
*
* In addition to Lo-Dash methods, wrappers also have the following `Array` methods:
* `concat`, `join`, `pop`, `push`, `reverse`, `shift`, `slice`, `sort`, `splice`,
* and `unshift`
*
* Chaining is supported in custom builds as long as the `value` method is
* implicitly or explicitly included in the build.
*
* The chainable wrapper functions are:
* `after`, `assign`, `bind`, `bindAll`, `bindKey`, `chain`, `compact`,
* `compose`, `concat`, `countBy`, `createCallback`, `debounce`, `defaults`,
* `defer`, `delay`, `difference`, `filter`, `flatten`, `forEach`, `forIn`,
* `forOwn`, `functions`, `groupBy`, `initial`, `intersection`, `invert`,
* `invoke`, `keys`, `map`, `max`, `memoize`, `merge`, `min`, `object`, `omit`,
* `once`, `pairs`, `partial`, `partialRight`, `pick`, `pluck`, `push`, `range`,
* `reject`, `rest`, `reverse`, `shuffle`, `slice`, `sort`, `sortBy`, `splice`,
* `tap`, `throttle`, `times`, `toArray`, `transform`, `union`, `uniq`, `unshift`,
* `unzip`, `values`, `where`, `without`, `wrap`, and `zip`
*
* The non-chainable wrapper functions are:
* `clone`, `cloneDeep`, `contains`, `escape`, `every`, `find`, `has`,
* `identity`, `indexOf`, `isArguments`, `isArray`, `isBoolean`, `isDate`,
* `isElement`, `isEmpty`, `isEqual`, `isFinite`, `isFunction`, `isNaN`,
* `isNull`, `isNumber`, `isObject`, `isPlainObject`, `isRegExp`, `isString`,
* `isUndefined`, `join`, `lastIndexOf`, `mixin`, `noConflict`, `parseInt`,
* `pop`, `random`, `reduce`, `reduceRight`, `result`, `shift`, `size`, `some`,
* `sortedIndex`, `runInContext`, `template`, `unescape`, `uniqueId`, and `value`
*
* The wrapper functions `first` and `last` return wrapped values when `n` is
* passed, otherwise they return unwrapped values.
*
* @name _
* @constructor
* @alias chain
* @category Chaining
* @param {Mixed} 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 {Mixed} value The value to wrap in a `lodash` instance.
* @returns {Object} Returns a `lodash` instance.
*/
function lodashWrapper(value) {
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 `Function#bind` exists and is inferred to be fast (all but V8).
*
* @memberOf _.support
* @type Boolean
*/
support.fastBind = nativeBind && !isV8;
/**
* Detect if `Array#shift` and `Array#splice` augment array-like objects correctly.
*
* Firefox < 10, IE compatibility mode, and IE < 9 have buggy Array `shift()`
* and `splice()` functions that fail to remove the last element, `value[0]`,
* of array-like objects even though the `length` property is set to `0`.
* The `shift()` method is buggy in IE 8 compatibility mode, while `splice()`
* is buggy regardless of mode in IE < 9 and buggy in compatibility mode in IE 9.
*
* @memberOf _.support
* @type Boolean
*/
support.spliceObjects = (arrayRef.splice.call(object, 0, 1), !object[0]);
}(1));
/**
* By default, the template delimiters used by Lo-Dash are similar to those in
* embedded Ruby (ERB). Change the following template settings to use alternative
* delimiters.
*
* @static
* @memberOf _
* @type Object
*/
lodash.templateSettings = {
/**
* Used to detect `data` property values to be HTML-escaped.
*
* @memberOf _.templateSettings
* @type RegExp
*/
'escape': /<%-([\s\S]+?)%>/g,
/**
* Used to detect code to be evaluated.
*
* @memberOf _.templateSettings
* @type RegExp
*/
'evaluate': /<%([\s\S]+?)%>/g,
/**
* Used to detect `data` property values to inject.
*
* @memberOf _.templateSettings
* @type RegExp
*/
'interpolate': reInterpolate,
/**
* Used to reference the data object in the template text.
*
* @memberOf _.templateSettings
* @type String
*/
'variable': ''
};
/*--------------------------------------------------------------------------*/
/**
* Creates a function that, when called, invokes `func` with the `this` binding
* of `thisArg` and prepends any `partialArgs` to the arguments passed to the
* bound function.
*
* @private
* @param {Function|String} func The function to bind or the method name.
* @param {Mixed} [thisArg] The `this` binding of `func`.
* @param {Array} partialArgs An array of arguments to be partially applied.
* @param {Object} [idicator] Used to indicate binding by key or partially
* applying arguments from the right.
* @returns {Function} Returns the new bound function.
*/
function createBound(func, thisArg, partialArgs, indicator) {
var isFunc = isFunction(func),
isPartial = !partialArgs,
key = thisArg;
// juggle arguments
if (isPartial) {
var rightIndicator = indicator;
partialArgs = thisArg;
}
else if (!isFunc) {
if (!indicator) {
throw new TypeError;
}
thisArg = func;
}
function bound() {
// `Function#bind` spec
// http://es5.github.com/#x15.3.4.5
var args = arguments,
thisBinding = isPartial ? this : thisArg;
if (!isFunc) {
func = thisArg[key];
}
if (partialArgs.length) {
args = args.length
? (args = nativeSlice.call(args), rightIndicator ? args.concat(partialArgs) : partialArgs.concat(args))
: partialArgs;
}
if (this instanceof bound) {
// ensure `new bound` is an instance of `func`
thisBinding = createObject(func.prototype);
// mimic the constructor's `return` behavior
// http://es5.github.com/#x13.2.2
var result = func.apply(thisBinding, args);
return isObject(result) ? result : thisBinding;
}
return func.apply(thisBinding, args);
}
return bound;
}
/**
* Creates a new object with the specified `prototype`.
*
* @private
* @param {Object} prototype The prototype object.
* @returns {Object} Returns the new object.
*/
function createObject(prototype) {
return isObject(prototype) ? nativeCreate(prototype) : {};
}
// fallback for browsers without `Object.create`
if (!nativeCreate) {
var createObject = function(prototype) {
if (isObject(prototype)) {
noop.prototype = prototype;
var result = new noop;
noop.prototype = null;
}
return result || {};
};
}
/**
* Used by `escape` to convert characters to HTML entities.
*
* @private
* @param {String} match The matched character to escape.
* @returns {String} Returns the escaped character.
*/
function escapeHtmlChar(match) {
return htmlEscapes[match];
}
/**
* Gets the appropriate "indexOf" function. If the `_.indexOf` method is
* customized, this method returns the custom method, otherwise it returns
* the `basicIndexOf` function.
*
* @private
* @returns {Function} Returns the "indexOf" function.
*/
function getIndexOf(array, value, fromIndex) {
var result = (result = lodash.indexOf) === indexOf ? basicIndexOf : result;
return result;
}
/**
* Used by `unescape` to convert HTML entities to characters.
*
* @private
* @param {String} match The matched character to unescape.
* @returns {String} Returns the unescaped character.
*/
function unescapeHtmlChar(match) {
return htmlUnescapes[match];
}
/*--------------------------------------------------------------------------*/
/**
* Checks if `value` is an `arguments` object.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true`, if the `value` is an `arguments` object, else `false`.
* @example
*
* (function() { return _.isArguments(arguments); })(1, 2, 3);
* // => true
*
* _.isArguments([1, 2, 3]);
* // => false
*/
function isArguments(value) {
return toString.call(value) == argsClass;
}
// fallback for browsers that can't detect `arguments` objects by [[Class]]
if (!isArguments(arguments)) {
isArguments = function(value) {
return value ? hasOwnProperty.call(value, 'callee') : false;
};
}
/**
* Checks if `value` is an array.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true`, if the `value` is an array, else `false`.
* @example
*
* (function() { return _.isArray(arguments); })();
* // => false
*
* _.isArray([1, 2, 3]);
* // => true
*/
var isArray = nativeIsArray || function(value) {
return value ? (typeof value == 'object' && toString.call(value) == arrayClass) : false;
};
/**
* A fallback implementation of `Object.keys` which produces an array of the
* given object's own enumerable property names.
*
* @private
* @type Function
* @param {Object} object The object to inspect.
* @returns {Array} Returns a new array of property names.
*/
var shimKeys = function(object) {
var index, iterable = object, result = [];
if (!iterable) return result;
if (!(objectTypes[typeof object])) return result;
for (index in iterable) {
if (hasOwnProperty.call(iterable, index)) {
result.push(index);
}
}
return result
};
/**
* Creates an array composed of the own enumerable property names of `object`.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The object to inspect.
* @returns {Array} Returns a new array of property names.
* @example
*
* _.keys({ 'one': 1, 'two': 2, 'three': 3 });
* // => ['one', 'two', 'three'] (order is not guaranteed)
*/
var keys = !nativeKeys ? shimKeys : function(object) {
if (!isObject(object)) {
return [];
}
return nativeKeys(object);
};
/**
* Used to convert characters to HTML entities:
*
* Though the `>` character is escaped for symmetry, characters like `>` and `/`
* don't require escaping in HTML and have no special meaning unless they're part
* of a tag or an unquoted attribute value.
* http://mathiasbynens.be/notes/ambiguous-ampersands (under "semi-related fun fact")
*/
var htmlEscapes = {
'&': '&',
'<': '<',
'>': '>',
'"': '"',
"'": '''
};
/** Used to convert HTML entities to characters */
var htmlUnescapes = invert(htmlEscapes);
/*--------------------------------------------------------------------------*/
/**
* Assigns own enumerable properties of source object(s) to the destination
* object. Subsequent sources will overwrite property assignments of previous
* sources. If a `callback` function is passed, it will be executed to produce
* the assigned values. The `callback` is bound to `thisArg` and invoked with
* two arguments; (objectValue, sourceValue).
*
* @static
* @memberOf _
* @type Function
* @alias extend
* @category Objects
* @param {Object} object The destination object.
* @param {Object} [source1, source2, ...] The source objects.
* @param {Function} [callback] The function to customize assigning values.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Object} Returns the destination object.
* @example
*
* _.assign({ 'name': 'moe' }, { 'age': 40 });
* // => { 'name': 'moe', 'age': 40 }
*
* var defaults = _.partialRight(_.assign, function(a, b) {
* return typeof a == 'undefined' ? b : a;
* });
*
* var food = { 'name': 'apple' };
* defaults(food, { 'name': 'banana', 'type': 'fruit' });
* // => { 'name': 'apple', 'type': 'fruit' }
*/
function assign(object) {
if (!object) {
return object;
}
for (var argsIndex = 1, argsLength = arguments.length; argsIndex < argsLength; argsIndex++) {
var iterable = arguments[argsIndex];
if (iterable) {
for (var key in iterable) {
object[key] = iterable[key];
}
}
}
return object;
}
/**
* Creates a clone of `value`. If `deep` is `true`, nested objects will also
* be cloned, otherwise they will be assigned by reference. If a `callback`
* function is passed, it will be executed to produce the cloned values. If
* `callback` returns `undefined`, cloning will be handled by the method instead.
* The `callback` is bound to `thisArg` and invoked with one argument; (value).
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to clone.
* @param {Boolean} [deep=false] A flag to indicate a deep clone.
* @param {Function} [callback] The function to customize cloning values.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @param- {Array} [stackA=[]] Tracks traversed source objects.
* @param- {Array} [stackB=[]] Associates clones with source counterparts.
* @returns {Mixed} Returns the cloned `value`.
* @example
*
* var stooges = [
* { 'name': 'moe', 'age': 40 },
* { 'name': 'larry', 'age': 50 }
* ];
*
* var shallow = _.clone(stooges);
* shallow[0] === stooges[0];
* // => true
*
* var deep = _.clone(stooges, true);
* deep[0] === stooges[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) ? nativeSlice.call(value) : assign({}, value))
: value;
}
/**
* Assigns own enumerable properties of source object(s) to the destination
* object for all destination properties that resolve to `undefined`. Once a
* property is set, additional defaults of the same property will be ignored.
*
* @static
* @memberOf _
* @type Function
* @category Objects
* @param {Object} object The destination object.
* @param {Object} [source1, source2, ...] The source objects.
* @param- {Object} [guard] Allows working with `_.reduce` without using its
* callback's `key` and `object` arguments as sources.
* @returns {Object} Returns the destination object.
* @example
*
* var food = { 'name': 'apple' };
* _.defaults(food, { 'name': 'banana', 'type': 'fruit' });
* // => { 'name': 'apple', 'type': 'fruit' }
*/
function defaults(object) {
if (!object) {
return object;
}
for (var argsIndex = 1, argsLength = arguments.length; argsIndex < argsLength; argsIndex++) {
var iterable = arguments[argsIndex];
if (iterable) {
for (var key in iterable) {
if (object[key] == null) {
object[key] = iterable[key];
}
}
}
}
return object;
}
/**
* Iterates over `object`'s own and inherited enumerable properties, executing
* the `callback` for each property. The `callback` is bound to `thisArg` and
* invoked with three arguments; (value, key, object). Callbacks may exit iteration
* early by explicitly returning `false`.
*
* @static
* @memberOf _
* @type Function
* @category Objects
* @param {Object} object The object to iterate over.
* @param {Function} [callback=identity] The function called per iteration.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Object} Returns `object`.
* @example
*
* function Dog(name) {
* this.name = name;
* }
*
* Dog.prototype.bark = function() {
* alert('Woof, woof!');
* };
*
* _.forIn(new Dog('Dagny'), function(value, key) {
* alert(key);
* });
* // => alerts 'name' and 'bark' (order is not guaranteed)
*/
var forIn = function(collection, callback) {
var index, iterable = collection, result = iterable;
if (!iterable) return result;
if (!objectTypes[typeof iterable]) return result;
for (index in iterable) {
if (callback(iterable[index], index, collection) === indicatorObject) return result;
}
return result
};
/**
* Iterates over an object's own enumerable properties, executing the `callback`
* for each property. The `callback` is bound to `thisArg` and invoked with three
* arguments; (value, key, object). Callbacks may exit iteration early by explicitly
* returning `false`.
*
* @static
* @memberOf _
* @type Function
* @category Objects
* @param {Object} object The object to iterate over.
* @param {Function} [callback=identity] The function called per iteration.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Object} Returns `object`.
* @example
*
* _.forOwn({ '0': 'zero', '1': 'one', 'length': 2 }, function(num, key) {
* alert(key);
* });
* // => alerts '0', '1', and 'length' (order is not guaranteed)
*/
var forOwn = function(collection, callback) {
var index, iterable = collection, result = iterable;
if (!iterable) return result;
if (!objectTypes[typeof iterable]) return result;
for (index in iterable) {
if (hasOwnProperty.call(iterable, index)) {
if (callback(iterable[index], index, collection) === indicatorObject) return result;
}
}
return result
};
/**
* Creates a sorted array of 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 a new array of property names that have function values.
* @example
*
* _.functions(_);
* // => ['all', 'any', 'bind', 'bindAll', 'clone', 'compact', 'compose', ...]
*/
function functions(object) {
var result = [];
forIn(object, function(value, key) {
if (isFunction(value)) {
result.push(key);
}
});
return result.sort();
}
/**
* Checks if the specified object `property` exists and is a direct property,
* instead of an inherited property.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The object to check.
* @param {String} property The property to check for.
* @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, property) {
return object ? hasOwnProperty.call(object, property) : false;
}
/**
* Creates an object composed of the inverted keys and values of the given `object`.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The object to invert.
* @returns {Object} Returns the created inverted object.
* @example
*
* _.invert({ 'first': 'moe', 'second': 'larry' });
* // => { 'moe': 'first', 'larry': 'second' }
*/
function invert(object) {
var index = -1,
props = keys(object),
length = props.length,
result = {};
while (++index < length) {
var key = props[index];
result[object[key]] = key;
}
return result;
}
/**
* Checks if `value` is a boolean value.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true`, if the `value` is a boolean value, else `false`.
* @example
*
* _.isBoolean(null);
* // => false
*/
function isBoolean(value) {
return value === true || value === false || toString.call(value) == boolClass;
}
/**
* Checks if `value` is a date.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true`, if the `value` is a date, else `false`.
* @example
*
* _.isDate(new Date);
* // => true
*/
function isDate(value) {
return value ? (typeof value == 'object' && toString.call(value) == dateClass) : false;
}
/**
* Checks if `value` is a DOM element.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true`, if the `value` is a DOM element, else `false`.
* @example
*
* _.isElement(document.body);
* // => true
*/
function isElement(value) {
return value ? value.nodeType === 1 : false;
}
/**
* Checks if `value` is empty. Arrays, strings, or `arguments` objects with a
* length of `0` and objects with no own enumerable properties are considered
* "empty".
*
* @static
* @memberOf _
* @category Objects
* @param {Array|Object|String} value The value to inspect.
* @returns {Boolean} Returns `true`, if the `value` is empty, else `false`.
* @example
*
* _.isEmpty([1, 2, 3]);
* // => false
*
* _.isEmpty({});
* // => true
*
* _.isEmpty('');
* // => true
*/
function isEmpty(value) {
if (!value) {
return true;
}
if (isArray(value) || isString(value)) {
return !value.length;
}
for (var key in value) {
if (hasOwnProperty.call(value, key)) {
return false;
}
}
return true;
}
/**
* Performs a deep comparison between two values to determine if they are
* equivalent to each other. If `callback` is passed, it will be executed to
* compare values. If `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 {Mixed} a The value to compare.
* @param {Mixed} b The other value to compare.
* @param {Function} [callback] The function to customize comparing values.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @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`.
* @example
*
* var moe = { 'name': 'moe', 'age': 40 };
* var copy = { 'name': 'moe', 'age': 40 };
*
* moe == copy;
* // => false
*
* _.isEqual(moe, 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, stackA, stackB) {
if (a === b) {
return a !== 0 || (1 / a == 1 / b);
}
var type = typeof a,
otherType = typeof b;
if (a === a &&
(!a || (type != 'function' && type != 'object')) &&
(!b || (otherType != 'function' && otherType != 'object'))) {
return false;
}
if (a == null || b == null) {
return a === b;
}
var className = toString.call(a),
otherClass = toString.call(b);
if (className != otherClass) {
return false;
}
switch (className) {
case boolClass:
case dateClass:
return +a == +b;
case numberClass:
return a != +a
? b != +b
: (a == 0 ? (1 / a == 1 / b) : a == +b);
case regexpClass:
case stringClass:
return a == String(b);
}
var isArr = className == arrayClass;
if (!isArr) {
if (a instanceof lodash || b instanceof lodash) {
return isEqual(a.__wrapped__ || a, b.__wrapped__ || b, stackA, stackB);
}
if (className != objectClass) {
return false;
}
var ctorA = a.constructor,
ctorB = b.constructor;
if (ctorA != ctorB && !(
isFunction(ctorA) && ctorA instanceof ctorA &&
isFunction(ctorB) && ctorB instanceof ctorB
)) {
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 = isEqual(a[size], b[size], stackA, stackB))) {
break;
}
}
}
return result;
}
forIn(b, function(value, key, b) {
if (hasOwnProperty.call(b, key)) {
size++;
return !(result = hasOwnProperty.call(a, key) && isEqual(a[key], value, stackA, stackB)) && indicatorObject;
}
});
if (result) {
forIn(a, function(value, key, a) {
if (hasOwnProperty.call(a, key)) {
return !(result = --size > -1) && indicatorObject;
}
});
}
return result;
}
/**
* Checks if `value` is, or can be coerced to, a finite number.
*
* Note: This is not the same as native `isFinite`, which will return true for
* booleans and empty strings. See http://es5.github.com/#x15.1.2.5.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true`, if the `value` is finite, else `false`.
* @example
*
* _.isFinite(-101);
* // => true
*
* _.isFinite('10');
* // => true
*
* _.isFinite(true);
* // => false
*
* _.isFinite('');
* // => false
*
* _.isFinite(Infinity);
* // => false
*/
function isFinite(value) {
return nativeIsFinite(value) && !nativeIsNaN(parseFloat(value));
}
/**
* Checks if `value` is a function.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true`, if the `value` is a function, else `false`.
* @example
*
* _.isFunction(_);
* // => true
*/
function isFunction(value) {
return typeof value == 'function';
}
// fallback for older versions of Chrome and Safari
if (isFunction(/x/)) {
isFunction = function(value) {
return typeof value == 'function' && toString.call(value) == funcClass;
};
}
/**
* Checks if `value` is the language type of Object.
* (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true`, if the `value` is an object, else `false`.
* @example
*
* _.isObject({});
* // => true
*
* _.isObject([1, 2, 3]);
* // => true
*
* _.isObject(1);
* // => false
*/
function isObject(value) {
// check if the value is the ECMAScript language type of Object
// http://es5.github.com/#x8
// and avoid a V8 bug
// http://code.google.com/p/v8/issues/detail?id=2291
return !!(value && objectTypes[typeof value]);
}
/**
* Checks if `value` is `NaN`.
*
* Note: This is not the same as native `isNaN`, which will return `true` for
* `undefined` and other values. See http://es5.github.com/#x15.1.2.4.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true`, if the `value` is `NaN`, else `false`.
* @example
*
* _.isNaN(NaN);
* // => true
*
* _.isNaN(new Number(NaN));
* // => true
*
* isNaN(undefined);
* // => true
*
* _.isNaN(undefined);
* // => false
*/
function isNaN(value) {
// `NaN` as a primitive is the only value that is not equal to itself
// (perform the [[Class]] check first to avoid errors with some host objects in IE)
return isNumber(value) && value != +value
}
/**
* Checks if `value` is `null`.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true`, if the `value` is `null`, else `false`.
* @example
*
* _.isNull(null);
* // => true
*
* _.isNull(undefined);
* // => false
*/
function isNull(value) {
return value === null;
}
/**
* Checks if `value` is a number.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true`, if the `value` is a number, else `false`.
* @example
*
* _.isNumber(8.4 * 5);
* // => true
*/
function isNumber(value) {
return typeof value == 'number' || toString.call(value) == numberClass;
}
/**
* Checks if `value` is a regular expression.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true`, if the `value` is a regular expression, else `false`.
* @example
*
* _.isRegExp(/moe/);
* // => true
*/
function isRegExp(value) {
return !!(value && objectTypes[typeof value]) && toString.call(value) == regexpClass;
}
/**
* Checks if `value` is a string.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true`, if the `value` is a string, else `false`.
* @example
*
* _.isString('moe');
* // => true
*/
function isString(value) {
return typeof value == 'string' || toString.call(value) == stringClass;
}
/**
* Checks if `value` is `undefined`.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true`, if the `value` is `undefined`, else `false`.
* @example
*
* _.isUndefined(void 0);
* // => true
*/
function isUndefined(value) {
return typeof value == 'undefined';
}
/**
* Creates a shallow clone of `object` excluding the specified properties.
* Property names may be specified as individual arguments or as arrays of
* property names. If a `callback` function is passed, it will be executed
* for each property in the `object`, omitting the properties `callback`
* returns truthy for. The `callback` is bound to `thisArg` and invoked
* with three arguments; (value, key, object).
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The source object.
* @param {Function|String} callback|[prop1, prop2, ...] The properties to omit
* or the function called per iteration.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Object} Returns an object without the omitted properties.
* @example
*
* _.omit({ 'name': 'moe', 'age': 40 }, 'age');
* // => { 'name': 'moe' }
*
* _.omit({ 'name': 'moe', 'age': 40 }, function(value) {
* return typeof value == 'number';
* });
* // => { 'name': 'moe' }
*/
function omit(object) {
var indexOf = getIndexOf(),
props = concat.apply(arrayRef, nativeSlice.call(arguments, 1)),
result = {};
forIn(object, function(value, key) {
if (indexOf(props, key) < 0) {
result[key] = value;
}
});
return result;
}
/**
* Creates a two dimensional array of the 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({ 'moe': 30, 'larry': 40 });
* // => [['moe', 30], ['larry', 40]] (order is not guaranteed)
*/
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 `callback` is passed, it will be executed for each property in the
* `object`, picking the properties `callback` returns truthy for. The `callback`
* is bound to `thisArg` and invoked with three arguments; (value, key, object).
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The source object.
* @param {Array|Function|String} callback|[prop1, prop2, ...] The function called
* per iteration or properties to pick, either as individual arguments or arrays.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Object} Returns an object composed of the picked properties.
* @example
*
* _.pick({ 'name': 'moe', '_userid': 'moe1' }, 'name');
* // => { 'name': 'moe' }
*
* _.pick({ 'name': 'moe', '_userid': 'moe1' }, function(value, key) {
* return key.charAt(0) != '_';
* });
* // => { 'name': 'moe' }
*/
function pick(object) {
var index = -1,
props = concat.apply(arrayRef, nativeSlice.call(arguments, 1)),
length = props.length,
result = {};
while (++index < length) {
var prop = props[index];
if (prop in object) {
result[prop] = object[prop];
}
}
return result;
}
/**
* Creates an array composed of the own enumerable property values of `object`.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The object to inspect.
* @returns {Array} Returns a new array of property values.
* @example
*
* _.values({ 'one': 1, 'two': 2, 'three': 3 });
* // => [1, 2, 3] (order is not guaranteed)
*/
function values(object) {
var index = -1,
props = keys(object),
length = props.length,
result = Array(length);
while (++index < length) {
result[index] = object[props[index]];
}
return result;
}
/*--------------------------------------------------------------------------*/
/**
* Checks if a given `target` element is present in a `collection` using strict
* equality for comparisons, i.e. `===`. If `fromIndex` is negative, it is used
* as the offset from the end of the collection.
*
* @static
* @memberOf _
* @alias include
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Mixed} 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': 'moe', 'age': 40 }, 'moe');
* // => true
*
* _.contains('curly', 'ur');
* // => true
*/
function contains(collection, target) {
var indexOf = getIndexOf(),
length = collection ? collection.length : 0,
result = false;
if (length && typeof length == 'number') {
result = indexOf(collection, target) > -1;
} else {
forOwn(collection, function(value) {
return (result = value === target) && indicatorObject;
});
}
return result;
}
/**
* Creates an object composed of keys returned from running each element of the
* `collection` through the given `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 passed for `callback`, the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is passed 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 passed, it will be used to create
* a "_.pluck" or "_.where" style callback, respectively.
* @param {Mixed} [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 }
*/
function countBy(collection, callback, thisArg) {
var result = {};
callback = createCallback(callback, thisArg);
forEach(collection, function(value, key, collection) {
key = String(callback(value, key, collection));
(hasOwnProperty.call(result, key) ? result[key]++ : result[key] = 1);
});
return result;
}
/**
* Checks if the `callback` returns a truthy value for **all** elements of a
* `collection`. The `callback` is bound to `thisArg` and invoked with three
* arguments; (value, index|key, collection).
*
* If a property name is passed for `callback`, the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is passed for `callback`, the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @alias all
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Function|Object|String} [callback=identity] The function called per
* iteration. If a property name or object is passed, it will be used to create
* a "_.pluck" or "_.where" style callback, respectively.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Boolean} Returns `true` if all elements pass the callback check,
* else `false`.
* @example
*
* _.every([true, 1, null, 'yes'], Boolean);
* // => false
*
* var stooges = [
* { 'name': 'moe', 'age': 40 },
* { 'name': 'larry', 'age': 50 }
* ];
*
* // using "_.pluck" callback shorthand
* _.every(stooges, 'age');
* // => true
*
* // using "_.where" callback shorthand
* _.every(stooges, { 'age': 50 });
* // => false
*/
function every(collection, callback, thisArg) {
var result = true;
callback = createCallback(callback, thisArg);
var index = -1,
length = collection ? collection.length : 0;
if (typeof length == 'number') {
while (++index < length) {
if (!(result = !!callback(collection[index], index, collection))) {
break;
}
}
} else {
forOwn(collection, function(value, index, collection) {
return !(result = !!callback(value, index, collection)) && indicatorObject;
});
}
return result;
}
/**
* Examines each element in a `collection`, returning an array of all elements
* the `callback` returns truthy for. The `callback` is bound to `thisArg` and
* invoked with three arguments; (value, index|key, collection).
*
* If a property name is passed for `callback`, the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is passed for `callback`, the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @alias select
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Function|Object|String} [callback=identity] The function called per
* iteration. If a property name or object is passed, it will be used to create
* a "_.pluck" or "_.where" style callback, respectively.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Array} Returns a new array of elements that passed the callback check.
* @example
*
* var evens = _.filter([1, 2, 3, 4, 5, 6], function(num) { return num % 2 == 0; });
* // => [2, 4, 6]
*
* var food = [
* { 'name': 'apple', 'organic': false, 'type': 'fruit' },
* { 'name': 'carrot', 'organic': true, 'type': 'vegetable' }
* ];
*
* // using "_.pluck" callback shorthand
* _.filter(food, 'organic');
* // => [{ 'name': 'carrot', 'organic': true, 'type': 'vegetable' }]
*
* // using "_.where" callback shorthand
* _.filter(food, { 'type': 'fruit' });
* // => [{ 'name': 'apple', 'organic': false, 'type': 'fruit' }]
*/
function filter(collection, callback, thisArg) {
var result = [];
callback = createCallback(callback, thisArg);
var index = -1,
length = collection ? collection.length : 0;
if (typeof length == 'number') {
while (++index < length) {
var value = collection[index];
if (callback(value, index, collection)) {
result.push(value);
}
}
} else {
forOwn(collection, function(value, index, collection) {
if (callback(value, index, collection)) {
result.push(value);
}
});
}
return result;
}
/**
* Examines each element in a `collection`, returning the first that the `callback`
* returns truthy for. The `callback` is bound to `thisArg` and invoked with three
* arguments; (value, index|key, collection).
*
* If a property name is passed for `callback`, the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is passed for `callback`, the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @alias detect, findWhere
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Function|Object|String} [callback=identity] The function called per
* iteration. If a property name or object is passed, it will be used to create
* a "_.pluck" or "_.where" style callback, respectively.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Mixed} Returns the found element, else `undefined`.
* @example
*
* _.find([1, 2, 3, 4], function(num) {
* return num % 2 == 0;
* });
* // => 2
*
* var food = [
* { 'name': 'apple', 'organic': false, 'type': 'fruit' },
* { 'name': 'banana', 'organic': true, 'type': 'fruit' },
* { 'name': 'beet', 'organic': false, 'type': 'vegetable' }
* ];
*
* // using "_.where" callback shorthand
* _.find(food, { 'type': 'vegetable' });
* // => { 'name': 'beet', 'organic': false, 'type': 'vegetable' }
*
* // using "_.pluck" callback shorthand
* _.find(food, 'organic');
* // => { 'name': 'banana', 'organic': true, 'type': 'fruit' }
*/
function find(collection, callback, thisArg) {
callback = createCallback(callback, thisArg);
var index = -1,
length = collection ? collection.length : 0;
if (typeof length == 'number') {
while (++index < length) {
var value = collection[index];
if (callback(value, index, collection)) {
return value;
}
}
} else {
var result;
forOwn(collection, function(value, index, collection) {
if (callback(value, index, collection)) {
result = value;
return indicatorObject;
}
});
return result;
}
}
/**
* Examines each element in a `collection`, returning the first that
* has the given `properties`. When checking `properties`, this method
* performs a deep comparison between values to determine if they are
* equivalent to each other.
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Object} properties The object of property values to filter by.
* @returns {Mixed} Returns the found element, else `undefined`.
* @example
*
* var food = [
* { 'name': 'apple', 'organic': false, 'type': 'fruit' },
* { 'name': 'banana', 'organic': true, 'type': 'fruit' },
* { 'name': 'beet', 'organic': false, 'type': 'vegetable' }
* ];
*
* _.findWhere(food, { 'type': 'vegetable' });
* // => { 'name': 'beet', 'organic': false, 'type': 'vegetable' }
*/
function findWhere(object, properties) {
return where(object, properties, true);
}
/**
* Iterates over a `collection`, executing the `callback` for each element in
* the `collection`. The `callback` is bound to `thisArg` and invoked with three
* arguments; (value, index|key, collection). Callbacks may exit iteration early
* by explicitly returning `false`.
*
* @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 {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Array|Object|String} Returns `collection`.
* @example
*
* _([1, 2, 3]).forEach(alert).join(',');
* // => alerts each number and returns '1,2,3'
*
* _.forEach({ 'one': 1, 'two': 2, 'three': 3 }, alert);
* // => alerts each number value (order is not guaranteed)
*/
function forEach(collection, callback, thisArg) {
var index = -1,
length = collection ? collection.length : 0;
callback = callback && typeof thisArg == 'undefined' ? callback : createCallback(callback, thisArg);
if (typeof length == 'number') {
while (++index < length) {
if (callback(collection[index], index, collection) === indicatorObject) {
break;
}
}
} else {
forOwn(collection, callback);
};
}
/**
* Creates an object composed of keys returned from running each element of the
* `collection` through the `callback`. The corresponding value of each key is
* an array of elements passed to `callback` that returned the key. The `callback`
* is bound to `thisArg` and invoked with three arguments; (value, index|key, collection).
*
* If a property name is passed for `callback`, the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is passed 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 passed, it will be used to create
* a "_.pluck" or "_.where" style callback, respectively.
* @param {Mixed} [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'] }
*/
function groupBy(collection, callback, thisArg) {
var result = {};
callback = createCallback(callback, thisArg);
forEach(collection, function(value, key, collection) {
key = String(callback(value, key, collection));
(hasOwnProperty.call(result, key) ? result[key] : result[key] = []).push(value);
});
return result;
}
/**
* 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 passed 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 {Mixed} [arg1, arg2, ...] Arguments to invoke the method with.
* @returns {Array} Returns a new array of the results of each invoked method.
* @example
*
* _.invoke([[5, 1, 7], [3, 2, 1]], 'sort');
* // => [[1, 5, 7], [1, 2, 3]]
*
* _.invoke([123, 456], String.prototype.split, '');
* // => [['1', '2', '3'], ['4', '5', '6']]
*/
function invoke(collection, methodName) {
var args = nativeSlice.call(arguments, 2),
index = -1,
isFunc = typeof methodName == 'function',
length = collection ? collection.length : 0,
result = Array(typeof length == 'number' ? length : 0);
forEach(collection, function(value) {
result[++index] = (isFunc ? methodName : value[methodName]).apply(value, args);
});
return result;
}
/**
* Creates an array of values by running each element in the `collection`
* through the `callback`. The `callback` is bound to `thisArg` and invoked with
* three arguments; (value, index|key, collection).
*
* If a property name is passed for `callback`, the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is passed 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 passed, it will be used to create
* a "_.pluck" or "_.where" style callback, respectively.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Array} Returns a new array of the results of each `callback` execution.
* @example
*
* _.map([1, 2, 3], function(num) { return num * 3; });
* // => [3, 6, 9]
*
* _.map({ 'one': 1, 'two': 2, 'three': 3 }, function(num) { return num * 3; });
* // => [3, 6, 9] (order is not guaranteed)
*
* var stooges = [
* { 'name': 'moe', 'age': 40 },
* { 'name': 'larry', 'age': 50 }
* ];
*
* // using "_.pluck" callback shorthand
* _.map(stooges, 'name');
* // => ['moe', 'larry']
*/
function map(collection, callback, thisArg) {
var index = -1,
length = collection ? collection.length : 0;
callback = createCallback(callback, thisArg);
if (typeof length == 'number') {
var result = Array(length);
while (++index < length) {
result[index] = callback(collection[index], index, collection);
}
} else {
result = [];
forOwn(collection, function(value, key, collection) {
result[++index] = callback(value, key, collection);
});
}
return result;
}
/**
* Retrieves the maximum value of an `array`. If `callback` is passed,
* it will be executed for each value in the `array` 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 passed for `callback`, the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is passed 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 passed, it will be used to create
* a "_.pluck" or "_.where" style callback, respectively.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Mixed} Returns the maximum value.
* @example
*
* _.max([4, 2, 8, 6]);
* // => 8
*
* var stooges = [
* { 'name': 'moe', 'age': 40 },
* { 'name': 'larry', 'age': 50 }
* ];
*
* _.max(stooges, function(stooge) { return stooge.age; });
* // => { 'name': 'larry', 'age': 50 };
*
* // using "_.pluck" callback shorthand
* _.max(stooges, 'age');
* // => { 'name': 'larry', 'age': 50 };
*/
function max(collection, callback, thisArg) {
var computed = -Infinity,
result = computed;
var index = -1,
length = collection ? collection.length : 0;
if (!callback && typeof length == 'number') {
while (++index < length) {
var value = collection[index];
if (value > result) {
result = value;
}
}
} else {
callback = createCallback(callback, thisArg);
forEach(collection, function(value, index, collection) {
var current = callback(value, index, collection);
if (current > computed) {
computed = current;
result = value;
}
});
}
return result;
}
/**
* Retrieves the minimum value of an `array`. If `callback` is passed,
* it will be executed for each value in the `array` 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 passed for `callback`, the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is passed 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 passed, it will be used to create
* a "_.pluck" or "_.where" style callback, respectively.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Mixed} Returns the minimum value.
* @example
*
* _.min([4, 2, 8, 6]);
* // => 2
*
* var stooges = [
* { 'name': 'moe', 'age': 40 },
* { 'name': 'larry', 'age': 50 }
* ];
*
* _.min(stooges, function(stooge) { return stooge.age; });
* // => { 'name': 'moe', 'age': 40 };
*
* // using "_.pluck" callback shorthand
* _.min(stooges, 'age');
* // => { 'name': 'moe', 'age': 40 };
*/
function min(collection, callback, thisArg) {
var computed = Infinity,
result = computed;
var index = -1,
length = collection ? collection.length : 0;
if (!callback && typeof length == 'number') {
while (++index < length) {
var value = collection[index];
if (value < result) {
result = value;
}
}
} else {
callback = createCallback(callback, thisArg);
forEach(collection, function(value, index, collection) {
var current = callback(value, index, collection);
if (current < computed) {
computed = current;
result = value;
}
});
}
return result;
}
/**
* Retrieves the value of a specified property from all elements in the `collection`.
*
* @static
* @memberOf _
* @type Function
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {String} property The property to pluck.
* @returns {Array} Returns a new array of property values.
* @example
*
* var stooges = [
* { 'name': 'moe', 'age': 40 },
* { 'name': 'larry', 'age': 50 }
* ];
*
* _.pluck(stooges, 'name');
* // => ['moe', 'larry']
*/
function pluck(collection, property) {
var index = -1,
length = collection ? collection.length : 0;
if (typeof length == 'number') {
var result = Array(length);
while (++index < length) {
result[index] = collection[index][property];
}
}
return result || map(collection, property);
}
/**
* 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 passed, 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 {Mixed} [accumulator] Initial value of the accumulator.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Mixed} Returns the accumulated value.
* @example
*
* var sum = _.reduce([1, 2, 3], function(sum, num) {
* return sum + num;
* });
* // => 6
*
* var mapped = _.reduce({ 'a': 1, 'b': 2, 'c': 3 }, function(result, num, key) {
* result[key] = num * 3;
* return result;
* }, {});
* // => { 'a': 3, 'b': 6, 'c': 9 }
*/
function reduce(collection, callback, accumulator, thisArg) {
if (!collection) return accumulator;
var noaccum = arguments.length < 3;
callback = createCallback(callback, thisArg, 4);
var index = -1,
length = collection.length;
if (typeof length == 'number') {
if (noaccum) {
accumulator = collection[++index];
}
while (++index < length) {
accumulator = callback(accumulator, collection[index], index, collection);
}
} else {
forOwn(collection, function(value, index, collection) {
accumulator = noaccum
? (noaccum = false, value)
: callback(accumulator, value, index, collection)
});
}
return accumulator;
}
/**
* This method is similar to `_.reduce`, except that it iterates over 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 {Mixed} [accumulator] Initial value of the accumulator.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Mixed} 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 iterable = collection,
length = collection ? collection.length : 0,
noaccum = arguments.length < 3;
if (typeof length != 'number') {
var props = keys(collection);
length = props.length;
}
callback = createCallback(callback, thisArg, 4);
forEach(collection, function(value, index, collection) {
index = props ? props[--length] : --length;
accumulator = noaccum
? (noaccum = false, iterable[index])
: callback(accumulator, iterable[index], index, collection);
});
return accumulator;
}
/**
* The opposite of `_.filter`, this method returns the elements of a
* `collection` that `callback` does **not** return truthy for.
*
* If a property name is passed for `callback`, the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is passed 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 passed, it will be used to create
* a "_.pluck" or "_.where" style callback, respectively.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Array} Returns a new array of elements that did **not** pass the
* callback check.
* @example
*
* var odds = _.reject([1, 2, 3, 4, 5, 6], function(num) { return num % 2 == 0; });
* // => [1, 3, 5]
*
* var food = [
* { 'name': 'apple', 'organic': false, 'type': 'fruit' },
* { 'name': 'carrot', 'organic': true, 'type': 'vegetable' }
* ];
*
* // using "_.pluck" callback shorthand
* _.reject(food, 'organic');
* // => [{ 'name': 'apple', 'organic': false, 'type': 'fruit' }]
*
* // using "_.where" callback shorthand
* _.reject(food, { 'type': 'fruit' });
* // => [{ 'name': 'carrot', 'organic': true, 'type': 'vegetable' }]
*/
function reject(collection, callback, thisArg) {
callback = createCallback(callback, thisArg);
return filter(collection, function(value, index, collection) {
return !callback(value, index, collection);
});
}
/**
* Creates an array of shuffled `array` values, using a version of the
* Fisher-Yates shuffle. See http://en.wikipedia.org/wiki/Fisher-Yates_shuffle.
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|String} collection The collection to shuffle.
* @returns {Array} Returns a new shuffled collection.
* @example
*
* _.shuffle([1, 2, 3, 4, 5, 6]);
* // => [4, 1, 6, 3, 5, 2]
*/
function shuffle(collection) {
var index = -1,
length = collection ? collection.length : 0,
result = Array(typeof length == 'number' ? length : 0);
forEach(collection, function(value) {
var rand = floor(nativeRandom() * (++index + 1));
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('curly');
* // => 5
*/
function size(collection) {
var length = collection ? collection.length : 0;
return typeof length == 'number' ? length : keys(collection).length;
}
/**
* Checks if the `callback` returns a truthy value for **any** element of a
* `collection`. The function returns as soon as it finds passing value, and
* does not iterate over the entire `collection`. The `callback` is bound to
* `thisArg` and invoked with three arguments; (value, index|key, collection).
*
* If a property name is passed for `callback`, the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is passed for `callback`, the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @alias any
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Function|Object|String} [callback=identity] The function called per
* iteration. If a property name or object is passed, it will be used to create
* a "_.pluck" or "_.where" style callback, respectively.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Boolean} Returns `true` if any element passes the callback check,
* else `false`.
* @example
*
* _.some([null, 0, 'yes', false], Boolean);
* // => true
*
* var food = [
* { 'name': 'apple', 'organic': false, 'type': 'fruit' },
* { 'name': 'carrot', 'organic': true, 'type': 'vegetable' }
* ];
*
* // using "_.pluck" callback shorthand
* _.some(food, 'organic');
* // => true
*
* // using "_.where" callback shorthand
* _.some(food, { 'type': 'meat' });
* // => false
*/
function some(collection, callback, thisArg) {
var result;
callback = createCallback(callback, thisArg);
var index = -1,
length = collection ? collection.length : 0;
if (typeof length == 'number') {
while (++index < length) {
if ((result = callback(collection[index], index, collection))) {
break;
}
}
} else {
forOwn(collection, function(value, index, collection) {
return (result = callback(value, index, collection)) && indicatorObject;
});
}
return !!result;
}
/**
* Creates an array of elements, sorted in ascending order by the results of
* running each element in the `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 passed for `callback`, the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is passed 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 passed, it will be used to create
* a "_.pluck" or "_.where" style callback, respectively.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Array} Returns a new array of sorted elements.
* @example
*
* _.sortBy([1, 2, 3], function(num) { return Math.sin(num); });
* // => [3, 1, 2]
*
* _.sortBy([1, 2, 3], function(num) { return this.sin(num); }, Math);
* // => [3, 1, 2]
*
* // using "_.pluck" callback shorthand
* _.sortBy(['banana', 'strawberry', 'apple'], 'length');
* // => ['apple', 'banana', 'strawberry']
*/
function sortBy(collection, callback, thisArg) {
var index = -1,
length = collection ? collection.length : 0,
result = Array(typeof length == 'number' ? length : 0);
callback = createCallback(callback, thisArg);
forEach(collection, function(value, key, collection) {
result[++index] = {
'criteria': callback(value, key, collection),
'index': index,
'value': value
};
});
length = result.length;
result.sort(compareAscending);
while (length--) {
result[length] = result[length].value;
}
return result;
}
/**
* Converts the `collection` to an array.
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|String} collection The collection to convert.
* @returns {Array} Returns the new converted array.
* @example
*
* (function() { return _.toArray(arguments).slice(1); })(1, 2, 3, 4);
* // => [2, 3, 4]
*/
function toArray(collection) {
if (isArray(collection)) {
return nativeSlice.call(collection);
}
if (collection && typeof collection.length == 'number') {
return map(collection);
}
return values(collection);
}
/**
* Examines each element in a `collection`, returning an array of all elements
* that have the given `properties`. When checking `properties`, this method
* performs a deep comparison between values to determine if they are equivalent
* to each other.
*
* @static
* @memberOf _
* @type Function
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Object} properties The object of property values to filter by.
* @returns {Array} Returns a new array of elements that have the given `properties`.
* @example
*
* var stooges = [
* { 'name': 'moe', 'age': 40 },
* { 'name': 'larry', 'age': 50 }
* ];
*
* _.where(stooges, { 'age': 40 });
* // => [{ 'name': 'moe', 'age': 40 }]
*/
function where(collection, properties, first) {
return (first && isEmpty(properties))
? null
: (first ? find : filter)(collection, properties);
}
/*--------------------------------------------------------------------------*/
/**
* Creates an array with all falsey values of `array` removed. The values
* `false`, `null`, `0`, `""`, `undefined` and `NaN` are all falsey.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to compact.
* @returns {Array} Returns a new filtered array.
* @example
*
* _.compact([0, 1, false, 2, '', 3]);
* // => [1, 2, 3]
*/
function compact(array) {
var index = -1,
length = array ? array.length : 0,
result = [];
while (++index < length) {
var value = array[index];
if (value) {
result.push(value);
}
}
return result;
}
/**
* Creates an array of `array` elements not present in the other arrays
* using strict equality for comparisons, i.e. `===`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to process.
* @param {Array} [array1, array2, ...] Arrays to check.
* @returns {Array} Returns a new array of `array` elements not present in the
* other arrays.
* @example
*
* _.difference([1, 2, 3, 4, 5], [5, 2, 10]);
* // => [1, 3, 4]
*/
function difference(array) {
var index = -1,
indexOf = getIndexOf(),
length = array.length,
flattened = concat.apply(arrayRef, nativeSlice.call(arguments, 1)),
result = [];
while (++index < length) {
var value = array[index];
if (indexOf(flattened, value) < 0) {
result.push(value);
}
}
return result;
}
/**
* Gets the first element of the `array`. If a number `n` is passed, the first
* `n` elements of the `array` are returned. If a `callback` function is passed,
* elements at the beginning of the array are returned as long as the `callback`
* returns truthy. The `callback` is bound to `thisArg` and invoked with three
* arguments; (value, index, array).
*
* If a property name is passed for `callback`, the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is passed for `callback`, the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @alias head, take
* @category Arrays
* @param {Array} array The array to query.
* @param {Function|Object|Number|String} [callback|n] The function called
* per element or the number of elements to return. If a property name or
* object is passed, it will be used to create a "_.pluck" or "_.where"
* style callback, respectively.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Mixed} Returns the first element(s) of `array`.
* @example
*
* _.first([1, 2, 3]);
* // => 1
*
* _.first([1, 2, 3], 2);
* // => [1, 2]
*
* _.first([1, 2, 3], function(num) {
* return num < 3;
* });
* // => [1, 2]
*
* var food = [
* { 'name': 'banana', 'organic': true },
* { 'name': 'beet', 'organic': false },
* ];
*
* // using "_.pluck" callback shorthand
* _.first(food, 'organic');
* // => [{ 'name': 'banana', 'organic': true }]
*
* var food = [
* { 'name': 'apple', 'type': 'fruit' },
* { 'name': 'banana', 'type': 'fruit' },
* { 'name': 'beet', 'type': 'vegetable' }
* ];
*
* // using "_.where" callback shorthand
* _.first(food, { 'type': 'fruit' });
* // => [{ 'name': 'apple', 'type': 'fruit' }, { 'name': 'banana', 'type': 'fruit' }]
*/
function first(array, callback, thisArg) {
if (array) {
var n = 0,
length = array.length;
if (typeof callback != 'number' && callback != null) {
var index = -1;
callback = createCallback(callback, thisArg);
while (++index < length && callback(array[index], index, array)) {
n++;
}
} else {
n = callback;
if (n == null || thisArg) {
return array[0];
}
}
return nativeSlice.call(array, 0, nativeMin(nativeMax(0, n), length));
}
}
/**
* Flattens a nested array (the nesting can be to any depth). If `isShallow`
* is truthy, `array` will only be flattened a single level. If `callback`
* is passed, each element of `array` is passed through a `callback` before
* flattening. The `callback` is bound to `thisArg` and invoked with three
* arguments; (value, index, array).
*
* If a property name is passed for `callback`, the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is passed 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 indicate only flattening a single level.
* @param {Function|Object|String} [callback=identity] The function called per
* iteration. If a property name or object is passed, it will be used to create
* a "_.pluck" or "_.where" style callback, respectively.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Array} Returns a new flattened array.
* @example
*
* _.flatten([1, [2], [3, [[4]]]]);
* // => [1, 2, 3, 4];
*
* _.flatten([1, [2], [3, [[4]]]], true);
* // => [1, 2, 3, [[4]]];
*
* var stooges = [
* { 'name': 'curly', 'quotes': ['Oh, a wise guy, eh?', 'Poifect!'] },
* { 'name': 'moe', 'quotes': ['Spread out!', 'You knucklehead!'] }
* ];
*
* // using "_.pluck" callback shorthand
* _.flatten(stooges, 'quotes');
* // => ['Oh, a wise guy, eh?', 'Poifect!', 'Spread out!', 'You knucklehead!']
*/
function flatten(array, isShallow) {
var index = -1,
length = array ? array.length : 0,
result = [];
while (++index < length) {
var value = array[index];
if (isArray(value)) {
push.apply(result, isShallow ? value : flatten(value));
} else {
result.push(value);
}
}
return result;
}
/**
* 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, passing `true` for `fromIndex` will run a faster binary search.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to search.
* @param {Mixed} value The value to search for.
* @param {Boolean|Number} [fromIndex=0] The index to search from or `true` to
* perform a binary search on a sorted `array`.
* @returns {Number} Returns the index of the matched value or `-1`.
* @example
*
* _.indexOf([1, 2, 3, 1, 2, 3], 2);
* // => 1
*
* _.indexOf([1, 2, 3, 1, 2, 3], 2, 3);
* // => 4
*
* _.indexOf([1, 1, 2, 2, 3, 3], 2, true);
* // => 2
*/
function indexOf(array, value, fromIndex) {
if (typeof fromIndex == 'number') {
var length = array ? array.length : 0;
fromIndex = (fromIndex < 0 ? nativeMax(0, length + fromIndex) : fromIndex || 0);
} else if (fromIndex) {
var index = sortedIndex(array, value);
return array[index] === value ? index : -1;
}
return array ? basicIndexOf(array, value, fromIndex) : -1;
}
/**
* Gets all but the last element of `array`. If a number `n` is passed, the
* last `n` elements are excluded from the result. If a `callback` function
* is passed, elements at the end of the array are excluded from the result
* as long as the `callback` returns truthy. The `callback` is bound to
* `thisArg` and invoked with three arguments; (value, index, array).
*
* If a property name is passed for `callback`, the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is passed for `callback`, the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to query.
* @param {Function|Object|Number|String} [callback|n=1] The function called
* per element or the number of elements to exclude. If a property name or
* object is passed, it will be used to create a "_.pluck" or "_.where"
* style callback, respectively.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Array} Returns a slice of `array`.
* @example
*
* _.initial([1, 2, 3]);
* // => [1, 2]
*
* _.initial([1, 2, 3], 2);
* // => [1]
*
* _.initial([1, 2, 3], function(num) {
* return num > 1;
* });
* // => [1]
*
* var food = [
* { 'name': 'beet', 'organic': false },
* { 'name': 'carrot', 'organic': true }
* ];
*
* // using "_.pluck" callback shorthand
* _.initial(food, 'organic');
* // => [{ 'name': 'beet', 'organic': false }]
*
* var food = [
* { 'name': 'banana', 'type': 'fruit' },
* { 'name': 'beet', 'type': 'vegetable' },
* { 'name': 'carrot', 'type': 'vegetable' }
* ];
*
* // using "_.where" callback shorthand
* _.initial(food, { 'type': 'vegetable' });
* // => [{ 'name': 'banana', 'type': 'fruit' }]
*/
function initial(array, callback, thisArg) {
if (!array) {
return [];
}
var n = 0,
length = array.length;
if (typeof callback != 'number' && callback != null) {
var index = length;
callback = createCallback(callback, thisArg);
while (index-- && callback(array[index], index, array)) {
n++;
}
} else {
n = (callback == null || thisArg) ? 1 : callback || n;
}
return nativeSlice.call(array, 0, nativeMin(nativeMax(0, length - n), length));
}
/**
* Computes the intersection of all the passed-in arrays using strict equality
* for comparisons, i.e. `===`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} [array1, array2, ...] Arrays to process.
* @returns {Array} Returns a new array of unique elements that are present
* in **all** of the arrays.
* @example
*
* _.intersection([1, 2, 3], [101, 2, 1, 10], [2, 1]);
* // => [1, 2]
*/
function intersection(array) {
var args = arguments,
argsLength = args.length,
index = -1,
indexOf = getIndexOf(),
length = array ? array.length : 0,
result = [];
outer:
while (++index < length) {
var 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 the `array`. If a number `n` is passed, the
* last `n` elements of the `array` are returned. If a `callback` function
* is passed, elements at the end of the array are returned as long as the
* `callback` returns truthy. The `callback` is bound to `thisArg` and
* invoked with three arguments;(value, index, array).
*
*
* If a property name is passed for `callback`, the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is passed for `callback`, the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to query.
* @param {Function|Object|Number|String} [callback|n] The function called
* per element or the number of elements to return. If a property name or
* object is passed, it will be used to create a "_.pluck" or "_.where"
* style callback, respectively.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Mixed} Returns the last element(s) of `array`.
* @example
*
* _.last([1, 2, 3]);
* // => 3
*
* _.last([1, 2, 3], 2);
* // => [2, 3]
*
* _.last([1, 2, 3], function(num) {
* return num > 1;
* });
* // => [2, 3]
*
* var food = [
* { 'name': 'beet', 'organic': false },
* { 'name': 'carrot', 'organic': true }
* ];
*
* // using "_.pluck" callback shorthand
* _.last(food, 'organic');
* // => [{ 'name': 'carrot', 'organic': true }]
*
* var food = [
* { 'name': 'banana', 'type': 'fruit' },
* { 'name': 'beet', 'type': 'vegetable' },
* { 'name': 'carrot', 'type': 'vegetable' }
* ];
*
* // using "_.where" callback shorthand
* _.last(food, { 'type': 'vegetable' });
* // => [{ 'name': 'beet', 'type': 'vegetable' }, { 'name': 'carrot', 'type': 'vegetable' }]
*/
function last(array, callback, thisArg) {
if (array) {
var n = 0,
length = array.length;
if (typeof callback != 'number' && callback != null) {
var index = length;
callback = createCallback(callback, thisArg);
while (index-- && callback(array[index], index, array)) {
n++;
}
} else {
n = callback;
if (n == null || thisArg) {
return array[length - 1];
}
}
return nativeSlice.call(array, nativeMax(0, length - n));
}
}
/**
* Gets the index at which the last occurrence of `value` is found using strict
* equality for comparisons, i.e. `===`. If `fromIndex` is negative, it is used
* as the offset from the end of the collection.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to search.
* @param {Mixed} value The value to search for.
* @param {Number} [fromIndex=array.length-1] The index to search from.
* @returns {Number} Returns the index of the matched value or `-1`.
* @example
*
* _.lastIndexOf([1, 2, 3, 1, 2, 3], 2);
* // => 4
*
* _.lastIndexOf([1, 2, 3, 1, 2, 3], 2, 3);
* // => 1
*/
function lastIndexOf(array, value, fromIndex) {
var index = array ? array.length : 0;
if (typeof fromIndex == 'number') {
index = (fromIndex < 0 ? nativeMax(0, index + fromIndex) : nativeMin(fromIndex, index - 1)) + 1;
}
while (index--) {
if (array[index] === value) {
return index;
}
}
return -1;
}
/**
* Creates an array of numbers (positive and/or negative) progressing from
* `start` up to but not including `end`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Number} [start=0] The start of the range.
* @param {Number} end The end of the range.
* @param {Number} [step=1] The value to increment or decrement by.
* @returns {Array} Returns a new range array.
* @example
*
* _.range(10);
* // => [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
*
* _.range(1, 11);
* // => [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
*
* _.range(0, 30, 5);
* // => [0, 5, 10, 15, 20, 25]
*
* _.range(0, -10, -1);
* // => [0, -1, -2, -3, -4, -5, -6, -7, -8, -9]
*
* _.range(0);
* // => []
*/
function range(start, end, step) {
start = +start || 0;
step = +step || 1;
if (end == null) {
end = start;
start = 0;
}
// use `Array(length)` so V8 will avoid the slower "dictionary" mode
// http://youtu.be/XAqIpGU8ZZk#t=17m25s
var index = -1,
length = nativeMax(0, ceil((end - start) / step)),
result = Array(length);
while (++index < length) {
result[index] = start;
start += step;
}
return result;
}
/**
* The opposite of `_.initial`, this method gets all but the first value of
* `array`. If a number `n` is passed, the first `n` values are excluded from
* the result. If a `callback` function is passed, elements at the beginning
* of the array are excluded from the result as long as the `callback` returns
* truthy. The `callback` is bound to `thisArg` and invoked with three
* arguments; (value, index, array).
*
* If a property name is passed for `callback`, the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is passed for `callback`, the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @alias drop, tail
* @category Arrays
* @param {Array} array The array to query.
* @param {Function|Object|Number|String} [callback|n=1] The function called
* per element or the number of elements to exclude. If a property name or
* object is passed, it will be used to create a "_.pluck" or "_.where"
* style callback, respectively.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Array} Returns a slice of `array`.
* @example
*
* _.rest([1, 2, 3]);
* // => [2, 3]
*
* _.rest([1, 2, 3], 2);
* // => [3]
*
* _.rest([1, 2, 3], function(num) {
* return num < 3;
* });
* // => [3]
*
* var food = [
* { 'name': 'banana', 'organic': true },
* { 'name': 'beet', 'organic': false },
* ];
*
* // using "_.pluck" callback shorthand
* _.rest(food, 'organic');
* // => [{ 'name': 'beet', 'organic': false }]
*
* var food = [
* { 'name': 'apple', 'type': 'fruit' },
* { 'name': 'banana', 'type': 'fruit' },
* { 'name': 'beet', 'type': 'vegetable' }
* ];
*
* // using "_.where" callback shorthand
* _.rest(food, { 'type': 'fruit' });
* // => [{ 'name': 'beet', 'type': 'vegetable' }]
*/
function rest(array, callback, thisArg) {
if (typeof callback != 'number' && callback != null) {
var n = 0,
index = -1,
length = array ? array.length : 0;
callback = createCallback(callback, thisArg);
while (++index < length && callback(array[index], index, array)) {
n++;
}
} else {
n = (callback == null || thisArg) ? 1 : nativeMax(0, callback);
}
return nativeSlice.call(array, n);
}
/**
* Uses a binary search to determine the smallest index at which the `value`
* should be inserted into `array` in order to maintain the sort order of the
* sorted `array`. If `callback` is passed, it will be executed for `value` and
* each element in `array` to compute their sort ranking. The `callback` is
* bound to `thisArg` and invoked with one argument; (value).
*
* If a property name is passed for `callback`, the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is passed 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 {Mixed} value The value to evaluate.
* @param {Function|Object|String} [callback=identity] The function called per
* iteration. If a property name or object is passed, it will be used to create
* a "_.pluck" or "_.where" style callback, respectively.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Number} Returns the index at which the value should be inserted
* into `array`.
* @example
*
* _.sortedIndex([20, 30, 50], 40);
* // => 2
*
* // using "_.pluck" callback shorthand
* _.sortedIndex([{ 'x': 20 }, { 'x': 30 }, { 'x': 50 }], { 'x': 40 }, 'x');
* // => 2
*
* var dict = {
* 'wordToNumber': { 'twenty': 20, 'thirty': 30, 'fourty': 40, 'fifty': 50 }
* };
*
* _.sortedIndex(['twenty', 'thirty', 'fifty'], 'fourty', function(word) {
* return dict.wordToNumber[word];
* });
* // => 2
*
* _.sortedIndex(['twenty', 'thirty', 'fifty'], 'fourty', function(word) {
* return this.wordToNumber[word];
* }, dict);
* // => 2
*/
function sortedIndex(array, value, callback, thisArg) {
var low = 0,
high = array ? array.length : low;
// explicitly reference `identity` for better inlining in Firefox
callback = callback ? createCallback(callback, thisArg, 1) : identity;
value = callback(value);
while (low < high) {
var mid = (low + high) >>> 1;
(callback(array[mid]) < value)
? low = mid + 1
: high = mid;
}
return low;
}
/**
* Computes the union of the passed-in arrays using strict equality for
* comparisons, i.e. `===`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} [array1, array2, ...] Arrays to process.
* @returns {Array} Returns a new array of unique values, in order, that are
* present in one or more of the arrays.
* @example
*
* _.union([1, 2, 3], [101, 2, 1, 10], [2, 1]);
* // => [1, 2, 3, 101, 10]
*/
function union(array) {
if (!isArray(array)) {
arguments[0] = array ? nativeSlice.call(array) : arrayRef;
}
return uniq(concat.apply(arrayRef, arguments));
}
/**
* Creates a duplicate-value-free version of the `array` using strict equality
* for comparisons, i.e. `===`. If the `array` is already sorted, passing `true`
* for `isSorted` will run a faster algorithm. If `callback` is passed, 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 passed for `callback`, the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is passed 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 the `array` is already sorted.
* @param {Function|Object|String} [callback=identity] The function called per
* iteration. If a property name or object is passed, it will be used to create
* a "_.pluck" or "_.where" style callback, respectively.
* @param {Mixed} [thisArg] The `this` binding of `callback`.
* @returns {Array} Returns a duplicate-value-free array.
* @example
*
* _.uniq([1, 2, 1, 3, 1]);
* // => [1, 2, 3]
*
* _.uniq([1, 1, 2, 2, 3], true);
* // => [1, 2, 3]
*
* _.uniq(['A', 'b', 'C', 'a', 'B', 'c'], function(letter) { return letter.toLowerCase(); });
* // => ['A', 'b', 'C']
*
* _.uniq([1, 2.5, 3, 1.5, 2, 3.5], function(num) { return this.floor(num); }, Math);
* // => [1, 2.5, 3]
*
* // using "_.pluck" callback shorthand
* _.uniq([{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }], 'x');
* // => [{ 'x': 1 }, { 'x': 2 }]
*/
function uniq(array, isSorted, callback, thisArg) {
var index = -1,
indexOf = getIndexOf(),
length = array ? array.length : 0,
result = [],
seen = result;
if (typeof isSorted != 'boolean' && isSorted != null) {
thisArg = callback;
callback = isSorted;
isSorted = false;
}
if (callback != null) {
seen = [];
callback = createCallback(callback, thisArg);
}
while (++index < length) {
var value = array[index],
computed = callback ? callback(value, index, array) : value;
if (isSorted
? !index || seen[seen.length - 1] !== computed
: indexOf(seen, computed) < 0
) {
if (callback) {
seen.push(computed);
}
result.push(value);
}
}
return result;
}
/**
* The inverse of `_.zip`, this method splits groups of elements into arrays
* composed of elements from each group at their corresponding indexes.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to process.
* @returns {Array} Returns a new array of the composed arrays.
* @example
*
* _.unzip([['moe', 30, true], ['larry', 40, false]]);
* // => [['moe', 'larry'], [30, 40], [true, false]];
*/
function unzip(array) {
var index = -1,
length = array ? max(pluck(array, 'length')) : 0,
result = Array(length < 0 ? 0 : length);
while (++index < length) {
result[index] = pluck(array, index);
}
return result;
}
/**
* Creates an array with all occurrences of the passed values removed using
* strict equality for comparisons, i.e. `===`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to filter.
* @param {Mixed} [value1, value2, ...] Values to remove.
* @returns {Array} Returns a new filtered array.
* @example
*
* _.without([1, 2, 1, 0, 3, 1, 4], 0, 1);
* // => [2, 3, 4]
*/
function without(array) {
return difference(array, nativeSlice.call(arguments, 1));
}
/**
* Groups the elements of each array at their corresponding indexes. Useful for
* separate data sources that are coordinated through matching array indexes.
* For a matrix of nested arrays, `_.zip.apply(...)` can transpose the matrix
* in a similar fashion.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} [array1, array2, ...] Arrays to process.
* @returns {Array} Returns a new array of grouped elements.
* @example
*
* _.zip(['moe', 'larry'], [30, 40], [true, false]);
* // => [['moe', 30, true], ['larry', 40, false]]
*/
function zip(array) {
var index = -1,
length = array ? max(pluck(arguments, 'length')) : 0,
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`. Pass either
* a single two dimensional array, i.e. `[[key1, value1], [key2, value2]]`, or
* two arrays, one of `keys` and one of corresponding `values`.
*
* @static
* @memberOf _
* @alias object
* @category Arrays
* @param {Array} keys The array of keys.
* @param {Array} [values=[]] The array of values.
* @returns {Object} Returns an object composed of the given keys and
* corresponding values.
* @example
*
* _.zipObject(['moe', 'larry'], [30, 40]);
* // => { 'moe': 30, 'larry': 40 }
*/
function zipObject(keys, values) {
var index = -1,
length = keys ? keys.length : 0,
result = {};
while (++index < length) {
var key = keys[index];
if (values) {
result[key] = values[index];
} else {
result[key[0]] = key[1];
}
}
return result;
}
/*--------------------------------------------------------------------------*/
/**
* If `n` is greater than `0`, a function is created that is restricted to
* executing `func`, with the `this` binding and arguments of the created
* function, only after it is called `n` times. If `n` is less than `1`,
* `func` is executed immediately, without a `this` binding or additional
* arguments, and its result is returned.
*
* @static
* @memberOf _
* @category Functions
* @param {Number} n The number of times the function must be called before
* it is executed.
* @param {Function} func The function to restrict.
* @returns {Function} Returns the new restricted function.
* @example
*
* var renderNotes = _.after(notes.length, render);
* _.forEach(notes, function(note) {
* note.asyncSave({ 'success': renderNotes });
* });
* // `renderNotes` is run once, after all notes have saved
*/
function after(n, func) {
if (n < 1) {
return func();
}
return function() {
if (--n < 1) {
return func.apply(this, arguments);
}
};
}
/**
* Creates a function that, when called, invokes `func` with the `this`
* binding of `thisArg` and prepends any additional `bind` arguments to those
* passed to the bound function.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to bind.
* @param {Mixed} [thisArg] The `this` binding of `func`.
* @param {Mixed} [arg1, arg2, ...] 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': 'moe' }, 'hi');
* func();
* // => 'hi moe'
*/
function bind(func, thisArg) {
// use `Function#bind` if it exists and is fast
// (in V8 `Function#bind` is slower except when partially applied)
return support.fastBind || (nativeBind && arguments.length > 2)
? nativeBind.call.apply(nativeBind, arguments)
: createBound(func, thisArg, nativeSlice.call(arguments, 2));
}
/**
* Binds methods on `object` to `object`, overwriting the existing method.
* Method names may be specified as individual arguments or as arrays of method
* names. If no method names are provided, all the function properties of `object`
* will be bound.
*
* @static
* @memberOf _
* @category Functions
* @param {Object} object The object to bind and assign the bound methods to.
* @param {String} [methodName1, methodName2, ...] Method names on the object to bind.
* @returns {Object} Returns `object`.
* @example
*
* var view = {
* 'label': 'docs',
* 'onClick': function() { alert('clicked ' + this.label); }
* };
*
* _.bindAll(view);
* jQuery('#docs').on('click', view.onClick);
* // => alerts 'clicked docs', when the button is clicked
*/
function bindAll(object) {
var funcs = arguments.length > 1 ? concat.apply(arrayRef, nativeSlice.call(arguments, 1)) : functions(object),
index = -1,
length = funcs.length;
while (++index < length) {
var key = funcs[index];
object[key] = bind(object[key], object);
}
return object;
}
/**
* Creates a function that is the composition of the passed 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} [func1, func2, ...] Functions to compose.
* @returns {Function} Returns the new composed function.
* @example
*
* var greet = function(name) { return 'hi ' + name; };
* var exclaim = function(statement) { return statement + '!'; };
* var welcome = _.compose(exclaim, greet);
* welcome('moe');
* // => 'hi moe!'
*/
function compose() {
var funcs = arguments;
return function() {
var args = arguments,
length = funcs.length;
while (length--) {
args = [funcs[length].apply(this, args)];
}
return args[0];
};
}
/**
* Produces a callback bound to an optional `thisArg`. If `func` is a property
* name, the created callback will return the property value for a given element.
* If `func` is an object, the created callback will return `true` for elements
* that contain the equivalent object properties, otherwise it will return `false`.
*
* Note: All Lo-Dash methods, that accept a `callback` argument, use `_.createCallback`.
*
* @static
* @memberOf _
* @category Functions
* @param {Mixed} [func=identity] The value to convert to a callback.
* @param {Mixed} [thisArg] The `this` binding of the created callback.
* @param {Number} [argCount=3] The number of arguments the callback accepts.
* @returns {Function} Returns a callback function.
* @example
*
* var stooges = [
* { 'name': 'moe', 'age': 40 },
* { 'name': 'larry', 'age': 50 }
* ];
*
* // wrap to create custom callback shorthands
* _.createCallback = _.wrap(_.createCallback, function(func, callback, thisArg) {
* var match = /^(.+?)__([gl]t)(.+)$/.exec(callback);
* return !match ? func(callback, thisArg) : function(object) {
* return match[2] == 'gt' ? object[match[1]] > match[3] : object[match[1]] < match[3];
* };
* });
*
* _.filter(stooges, 'age__gt45');
* // => [{ 'name': 'larry', 'age': 50 }]
*
* // create mixins with support for "_.pluck" and "_.where" callback shorthands
* _.mixin({
* 'toLookup': function(collection, callback, thisArg) {
* callback = _.createCallback(callback, thisArg);
* return _.reduce(collection, function(result, value, index, collection) {
* return (result[callback(value, index, collection)] = value, result);
* }, {});
* }
* });
*
* _.toLookup(stooges, 'name');
* // => { 'moe': { 'name': 'moe', 'age': 40 }, 'larry': { 'name': 'larry', 'age': 50 } }
*/
function createCallback(func, thisArg, argCount) {
if (func == null) {
return identity;
}
var type = typeof func;
if (type != 'function') {
if (type != 'object') {
return function(object) {
return object[func];
};
}
var props = keys(func);
return function(object) {
var length = props.length,
result = false;
while (length--) {
if (!(result = object[props[length]] === func[props[length]])) {
break;
}
}
return result;
};
}
if (typeof thisArg == 'undefined') {
return func;
}
if (argCount === 1) {
return function(value) {
return func.call(thisArg, value);
};
}
if (argCount === 2) {
return function(a, b) {
return func.call(thisArg, a, b);
};
}
if (argCount === 4) {
return function(accumulator, value, index, collection) {
return func.call(thisArg, accumulator, value, index, collection);
};
}
return function(value, index, collection) {
return func.call(thisArg, value, index, collection);
};
}
/**
* Creates a function that will delay the execution of `func` until after
* `wait` milliseconds have elapsed since the last time it was invoked. Pass
* 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.
* [leading=false] A boolean to specify execution on the leading edge of the timeout.
* [maxWait] The maximum time `func` is allowed to be delayed before it's called.
* [trailing=true] A boolean to specify execution on the trailing edge of the timeout.
* @returns {Function} Returns the new debounced function.
* @example
*
* var lazyLayout = _.debounce(calculateLayout, 300);
* jQuery(window).on('resize', lazyLayout);
*
* jQuery('#postbox').on('click', _.debounce(sendMail, 200, {
* 'leading': true,
* 'trailing': false
* });
*/
function debounce(func, wait, immediate) {
var args,
result,
thisArg,
timeoutId = null;
function delayed() {
timeoutId = null;
if (!immediate) {
result = func.apply(thisArg, args);
}
}
return function() {
var isImmediate = immediate && !timeoutId;
args = arguments;
thisArg = this;
clearTimeout(timeoutId);
timeoutId = setTimeout(delayed, wait);
if (isImmediate) {
result = func.apply(thisArg, args);
}
return result;
};
}
/**
* Defers executing the `func` function until the current call stack has cleared.
* Additional arguments will be passed to `func` when it is invoked.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to defer.
* @param {Mixed} [arg1, arg2, ...] Arguments to invoke the function with.
* @returns {Number} Returns the timer id.
* @example
*
* _.defer(function() { alert('deferred'); });
* // returns from the function before `alert` is called
*/
function defer(func) {
var args = nativeSlice.call(arguments, 1);
return setTimeout(function() { func.apply(undefined, args); }, 1);
}
/**
* Executes the `func` function after `wait` milliseconds. Additional arguments
* will be passed 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 {Mixed} [arg1, arg2, ...] Arguments to invoke the function with.
* @returns {Number} Returns the timer id.
* @example
*
* var log = _.bind(console.log, console);
* _.delay(log, 1000, 'logged later');
* // => 'logged later' (Appears after one second.)
*/
function delay(func, wait) {
var args = nativeSlice.call(arguments, 2);
return setTimeout(function() { func.apply(undefined, args); }, wait);
}
/**
* Creates a function that memoizes the result of `func`. If `resolver` is
* passed, it will be used to determine the cache key for storing the result
* based on the arguments passed to the memoized function. By default, the first
* argument passed to the memoized function is used as the cache key. The `func`
* is executed with the `this` binding of the memoized function. The result
* cache is exposed as the `cache` property on the memoized function.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to have its output memoized.
* @param {Function} [resolver] A function used to resolve the cache key.
* @returns {Function} Returns the new memoizing function.
* @example
*
* var fibonacci = _.memoize(function(n) {
* return n < 2 ? n : fibonacci(n - 1) + fibonacci(n - 2);
* });
*/
function memoize(func, resolver) {
var cache = {};
return function() {
var key = keyPrefix + (resolver ? resolver.apply(this, arguments) : arguments[0]);
return hasOwnProperty.call(cache, key)
? cache[key]
: (cache[key] = func.apply(this, arguments));
};
}
/**
* Creates a function that is restricted to execute `func` once. Repeat calls to
* the function will return the value of the first call. The `func` is executed
* with the `this` binding of the created function.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to restrict.
* @returns {Function} Returns the new restricted function.
* @example
*
* var initialize = _.once(createApplication);
* initialize();
* initialize();
* // `initialize` executes `createApplication` once
*/
function once(func) {
var ran,
result;
return function() {
if (ran) {
return result;
}
ran = true;
result = func.apply(this, arguments);
// clear the `func` variable so the function may be garbage collected
func = null;
return result;
};
}
/**
* Creates a function that, when called, invokes `func` with any additional
* `partial` arguments prepended to those passed to the new function. This
* method is similar to `_.bind`, except it does **not** alter the `this` binding.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to partially apply arguments to.
* @param {Mixed} [arg1, arg2, ...] 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('moe');
* // => 'hi moe'
*/
function partial(func) {
return createBound(func, nativeSlice.call(arguments, 1));
}
/**
* Creates a function that, when executed, will only call the `func` function
* at most once per every `wait` milliseconds. Pass 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.
* [leading=true] A boolean to specify execution on the leading edge of the timeout.
* [trailing=true] A boolean to specify execution on the trailing edge of the timeout.
* @returns {Function} Returns the new throttled function.
* @example
*
* var throttled = _.throttle(updatePosition, 100);
* jQuery(window).on('scroll', throttled);
*
* jQuery('.interactive').on('click', _.throttle(renewToken, 300000, {
* 'trailing': false
* }));
*/
function throttle(func, wait) {
var args,
result,
thisArg,
lastCalled = 0,
timeoutId = null;
function trailingCall() {
lastCalled = new Date;
timeoutId = null;
result = func.apply(thisArg, args);
}
return function() {
var now = new Date,
remaining = wait - (now - lastCalled);
args = arguments;
thisArg = this;
if (remaining <= 0) {
clearTimeout(timeoutId);
timeoutId = null;
lastCalled = now;
result = func.apply(thisArg, args);
}
else if (!timeoutId) {
timeoutId = setTimeout(trailingCall, remaining);
}
return result;
};
}
/**
* Creates a function that passes `value` to the `wrapper` function as its
* first argument. Additional arguments passed to the function are appended
* to those passed to the `wrapper` function. The `wrapper` is executed with
* the `this` binding of the created function.
*
* @static
* @memberOf _
* @category Functions
* @param {Mixed} value The value to wrap.
* @param {Function} wrapper The wrapper function.
* @returns {Function} Returns the new function.
* @example
*
* var hello = function(name) { return 'hello ' + name; };
* hello = _.wrap(hello, function(func) {
* return 'before, ' + func('moe') + ', after';
* });
* hello();
* // => 'before, hello moe, after'
*/
function wrap(value, wrapper) {
return function() {
var args = [value];
push.apply(args, arguments);
return wrapper.apply(this, args);
};
}
/*--------------------------------------------------------------------------*/
/**
* Converts the characters `&`, `<`, `>`, `"`, and `'` in `string` to their
* corresponding HTML entities.
*
* @static
* @memberOf _
* @category Utilities
* @param {String} string The string to escape.
* @returns {String} Returns the escaped string.
* @example
*
* _.escape('Moe, Larry & Curly');
* // => 'Moe, Larry & Curly'
*/
function escape(string) {
return string == null ? '' : String(string).replace(reUnescapedHtml, escapeHtmlChar);
}
/**
* This method returns the first argument passed to it.
*
* @static
* @memberOf _
* @category Utilities
* @param {Mixed} value Any value.
* @returns {Mixed} Returns `value`.
* @example
*
* var moe = { 'name': 'moe' };
* moe === _.identity(moe);
* // => true
*/
function identity(value) {
return value;
}
/**
* Adds functions properties of `object` to the `lodash` function and chainable
* wrapper.
*
* @static
* @memberOf _
* @category Utilities
* @param {Object} object The object of function properties to add to `lodash`.
* @example
*
* _.mixin({
* 'capitalize': function(string) {
* return string.charAt(0).toUpperCase() + string.slice(1).toLowerCase();
* }
* });
*
* _.capitalize('moe');
* // => 'Moe'
*
* _('moe').capitalize();
* // => 'Moe'
*/
function mixin(object) {
forEach(functions(object), function(methodName) {
var func = lodash[methodName] = object[methodName];
lodash.prototype[methodName] = function() {
var args = [this.__wrapped__];
push.apply(args, arguments);
var result = func.apply(lodash, args);
if (this.__chain__) {
result = new lodashWrapper(result);
result.__chain__ = true;
}
return result;
};
});
}
/**
* Reverts the '_' variable to its previous value and returns a reference to
* the `lodash` function.
*
* @static
* @memberOf _
* @category Utilities
* @returns {Function} Returns the `lodash` function.
* @example
*
* var lodash = _.noConflict();
*/
function noConflict() {
window._ = oldDash;
return this;
}
/**
* Produces a random number between `min` and `max` (inclusive). If only one
* argument is passed, a number between `0` and the given number will be returned.
*
* @static
* @memberOf _
* @category Utilities
* @param {Number} [min=0] The minimum possible value.
* @param {Number} [max=1] The maximum possible value.
* @returns {Number} Returns a random number.
* @example
*
* _.random(0, 5);
* // => a number between 0 and 5
*
* _.random(5);
* // => also a number between 0 and 5
*/
function random(min, max) {
if (min == null && max == null) {
max = 1;
}
min = +min || 0;
if (max == null) {
max = min;
min = 0;
} else {
max = +max || 0;
}
var rand = nativeRandom();
return (min % 1 || max % 1)
? min + nativeMin(rand * (max - min + parseFloat('1e-' + ((rand +'').length - 1))), max)
: min + floor(rand * (max - min + 1));
}
/**
* Resolves the value of `property` on `object`. If `property` is a function,
* it will be invoked with the `this` binding of `object` and its result returned,
* else the property value is returned. If `object` is falsey, then `undefined`
* is returned.
*
* @static
* @memberOf _
* @category Utilities
* @param {Object} object The object to inspect.
* @param {String} property The property to get the value of.
* @returns {Mixed} Returns the resolved value.
* @example
*
* var object = {
* 'cheese': 'crumpets',
* 'stuff': function() {
* return 'nonsense';
* }
* };
*
* _.result(object, 'cheese');
* // => 'crumpets'
*
* _.result(object, 'stuff');
* // => 'nonsense'
*/
function result(object, property) {
var value = object ? object[property] : null;
return isFunction(value) ? object[property]() : value;
}
/**
* A micro-templating method that handles arbitrary delimiters, preserves
* whitespace, and correctly escapes quotes within interpolated code.
*
* Note: In the development build, `_.template` utilizes sourceURLs for easier
* debugging. See http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl
*
* For more information on precompiling templates see:
* http://lodash.com/#custom-builds
*
* For more information on Chrome extension sandboxes see:
* http://developer.chrome.com/stable/extensions/sandboxingEval.html
*
* @static
* @memberOf _
* @category Utilities
* @param {String} text The template text.
* @param {Object} data The data object used to populate the text.
* @param {Object} options The options object.
* escape - The "escape" delimiter regexp.
* evaluate - The "evaluate" delimiter regexp.
* interpolate - The "interpolate" delimiter regexp.
* sourceURL - The sourceURL of the template's compiled source.
* variable - The data object variable name.
* @returns {Function|String} Returns a compiled function when no `data` object
* is given, else it returns the interpolated text.
* @example
*
* // using a compiled template
* var compiled = _.template('hello <%= name %>');
* compiled({ 'name': 'moe' });
* // => 'hello moe'
*
* var list = '<% _.forEach(people, function(name) { %><%= name %><% }); %>';
* _.template(list, { 'people': ['moe', 'larry'] });
* // => 'moelarry'
*
* // using the "escape" delimiter to escape HTML in data property values
* _.template('<%- value %>', { 'value': '