/** * @license * Lo-Dash 2.3.0 (Custom Build) * Build: `lodash underscore exports="amd,commonjs,global,node" -o ./dist/lodash.underscore.js` * Copyright 2012-2013 The Dojo Foundation * Based on Underscore.js 1.5.2 * Copyright 2009-2013 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors * Available under MIT license */ ;(function() { /** Used as a safe reference for `undefined` in pre ES5 environments */ var undefined; /** Used to generate unique IDs */ var idCounter = 0; /** Used internally to indicate various things */ var indicatorObject = {}; /** Used to prefix keys to avoid issues with `__proto__` and properties on `Object.prototype` */ var keyPrefix = +new Date + ''; /** Used to match "interpolate" template delimiters */ var reInterpolate = /<%=([\s\S]+?)%>/g; /** Used to ensure capturing order of template delimiters */ var reNoMatch = /($^)/; /** Used to match unescaped characters in compiled string literals */ var reUnescapedString = /['\n\r\t\u2028\u2029\\]/g; /** `Object#toString` result shortcuts */ var argsClass = '[object Arguments]', arrayClass = '[object Array]', boolClass = '[object Boolean]', dateClass = '[object Date]', funcClass = '[object Function]', numberClass = '[object Number]', objectClass = '[object Object]', regexpClass = '[object RegExp]', stringClass = '[object String]'; /** Used to determine if values are of the language type Object */ var objectTypes = { 'boolean': false, 'function': true, 'object': true, 'number': false, 'string': false, 'undefined': false }; /** Used to escape characters for inclusion in compiled string literals */ var stringEscapes = { '\\': '\\', "'": "'", '\n': 'n', '\r': 'r', '\t': 't', '\u2028': 'u2028', '\u2029': 'u2029' }; /** Used as a reference to the global object */ var root = (objectTypes[typeof window] && window) || this; /** Detect free variable `exports` */ var freeExports = objectTypes[typeof exports] && exports && !exports.nodeType && exports; /** Detect free variable `module` */ var freeModule = objectTypes[typeof module] && module && !module.nodeType && module; /** Detect the popular CommonJS extension `module.exports` */ var moduleExports = freeModule && freeModule.exports === freeExports && freeExports; /** Detect free variable `global` from Node.js or Browserified code and use it as `root` */ var freeGlobal = objectTypes[typeof global] && global; if (freeGlobal && (freeGlobal.global === freeGlobal || freeGlobal.window === freeGlobal)) { root = freeGlobal; } /*--------------------------------------------------------------------------*/ /** * The base implementation of `_.indexOf` without support for binary searches * or `fromIndex` constraints. * * @private * @param {Array} array The array to search. * @param {*} value The value to search for. * @param {number} [fromIndex=0] The index to search from. * @returns {number} Returns the index of the matched value or `-1`. */ function baseIndexOf(array, value, fromIndex) { var index = (fromIndex || 0) - 1, length = array ? array.length : 0; while (++index < length) { if (array[index] === value) { return index; } } return -1; } /** * Used by `sortBy` to compare transformed `collection` elements, stable sorting * them in ascending order. * * @private * @param {Object} a The object to compare to `b`. * @param {Object} b The object to compare to `a`. * @returns {number} Returns the sort order indicator of `1` or `-1`. */ function compareAscending(a, b) { var ac = a.criteria, bc = b.criteria; // ensure a stable sort in V8 and other engines // http://code.google.com/p/v8/issues/detail?id=90 if (ac !== bc) { if (ac > bc || typeof ac == 'undefined') { return 1; } if (ac < bc || typeof bc == 'undefined') { return -1; } } // The JS engine embedded in Adobe applications like InDesign has a buggy // `Array#sort` implementation that causes it, under certain circumstances, // to return the same value for `a` and `b`. // See https://github.com/jashkenas/underscore/pull/1247 return a.index - b.index; } /** * Used by `template` to escape characters for inclusion in compiled * string literals. * * @private * @param {string} match The matched character to escape. * @returns {string} Returns the escaped character. */ function escapeStringChar(match) { return '\\' + stringEscapes[match]; } /** * Slices the `collection` from the `start` index up to, but not including, * the `end` index. * * Note: This function is used instead of `Array#slice` to support node lists * in IE < 9 and to ensure dense arrays are returned. * * @private * @param {Array|Object|string} collection The collection to slice. * @param {number} start The start index. * @param {number} end The end index. * @returns {Array} Returns the new array. */ function slice(array, start, end) { start || (start = 0); if (typeof end == 'undefined') { end = array ? array.length : 0; } var index = -1, length = end - start || 0, result = Array(length < 0 ? 0 : length); while (++index < length) { result[index] = array[start + index]; } return result; } /*--------------------------------------------------------------------------*/ /** * Used for `Array` method references. * * Normally `Array.prototype` would suffice, however, using an array literal * avoids issues in Narwhal. */ var arrayRef = []; /** Used for native method references */ var objectProto = Object.prototype; /** Used to restore the original `_` reference in `noConflict` */ var oldDash = root._; /** Used to resolve the internal [[Class]] of values */ var toString = objectProto.toString; /** Used to detect if a method is native */ var reNative = RegExp('^' + String(toString) .replace(/[.*+?^${}()|[\]\\]/g, '\\$&') .replace(/toString| for [^\]]+/g, '.*?') + '$' ); /** Native method shortcuts */ var ceil = Math.ceil, floor = Math.floor, hasOwnProperty = objectProto.hasOwnProperty, now = reNative.test(now = Date.now) && now || function() { return +new Date; }, push = arrayRef.push, propertyIsEnumerable = objectProto.propertyIsEnumerable; /* Native method shortcuts for methods with the same name as other `lodash` methods */ var nativeCreate = reNative.test(nativeCreate = Object.create) && nativeCreate, nativeIsArray = reNative.test(nativeIsArray = Array.isArray) && nativeIsArray, nativeIsFinite = root.isFinite, nativeIsNaN = root.isNaN, nativeKeys = reNative.test(nativeKeys = Object.keys) && nativeKeys, nativeMax = Math.max, nativeMin = Math.min, nativeRandom = Math.random; /*--------------------------------------------------------------------------*/ /** * Creates a `lodash` object which wraps the given value to enable intuitive * method chaining. * * In addition to Lo-Dash methods, wrappers also have the following `Array` methods: * `concat`, `join`, `pop`, `push`, `reverse`, `shift`, `slice`, `sort`, `splice`, * and `unshift` * * Chaining is supported in custom builds as long as the `value` method is * implicitly or explicitly included in the build. * * The chainable wrapper functions are: * `after`, `assign`, `bind`, `bindAll`, `bindKey`, `chain`, `compact`, * `compose`, `concat`, `countBy`, `create`, `createCallback`, `curry`, * `debounce`, `defaults`, `defer`, `delay`, `difference`, `filter`, `flatten`, * `forEach`, `forEachRight`, `forIn`, `forInRight`, `forOwn`, `forOwnRight`, * `functions`, `groupBy`, `indexBy`, `initial`, `intersection`, `invert`, * `invoke`, `keys`, `map`, `max`, `memoize`, `merge`, `min`, `object`, `omit`, * `once`, `pairs`, `partial`, `partialRight`, `pick`, `pluck`, `pull`, `push`, * `range`, `reject`, `remove`, `rest`, `reverse`, `shuffle`, `slice`, `sort`, * `sortBy`, `splice`, `tap`, `throttle`, `times`, `toArray`, `transform`, * `union`, `uniq`, `unshift`, `unzip`, `values`, `where`, `without`, `wrap`, * and `zip` * * The non-chainable wrapper functions are: * `clone`, `cloneDeep`, `contains`, `escape`, `every`, `find`, `findIndex`, * `findKey`, `findLast`, `findLastIndex`, `findLastKey`, `has`, `identity`, * `indexOf`, `isArguments`, `isArray`, `isBoolean`, `isDate`, `isElement`, * `isEmpty`, `isEqual`, `isFinite`, `isFunction`, `isNaN`, `isNull`, `isNumber`, * `isObject`, `isPlainObject`, `isRegExp`, `isString`, `isUndefined`, `join`, * `lastIndexOf`, `mixin`, `noConflict`, `parseInt`, `pop`, `random`, `reduce`, * `reduceRight`, `result`, `shift`, `size`, `some`, `sortedIndex`, `runInContext`, * `template`, `unescape`, `uniqueId`, and `value` * * The wrapper functions `first` and `last` return wrapped values when `n` is * provided, otherwise they return unwrapped values. * * Explicit chaining can be enabled by using the `_.chain` method. * * @name _ * @constructor * @category Chaining * @param {*} value The value to wrap in a `lodash` instance. * @returns {Object} Returns a `lodash` instance. * @example * * var wrapped = _([1, 2, 3]); * * // returns an unwrapped value * wrapped.reduce(function(sum, num) { * return sum + num; * }); * // => 6 * * // returns a wrapped value * var squares = wrapped.map(function(num) { * return num * num; * }); * * _.isArray(squares); * // => false * * _.isArray(squares.value()); * // => true */ function lodash(value) { return (value instanceof lodash) ? value : new lodashWrapper(value); } /** * A fast path for creating `lodash` wrapper objects. * * @private * @param {*} value The value to wrap in a `lodash` instance. * @param {boolean} chainAll A flag to enable chaining for all methods * @returns {Object} Returns a `lodash` instance. */ function lodashWrapper(value, chainAll) { this.__chain__ = !!chainAll; this.__wrapped__ = value; } // ensure `new lodashWrapper` is an instance of `lodash` lodashWrapper.prototype = lodash.prototype; /** * An object used to flag environments features. * * @static * @memberOf _ * @type Object */ var support = {}; (function() { var object = { '0': 1, 'length': 1 }; /** * Detect if `Array#shift` and `Array#splice` augment array-like objects correctly. * * Firefox < 10, IE compatibility mode, and IE < 9 have buggy Array `shift()` * and `splice()` functions that fail to remove the last element, `value[0]`, * of array-like objects even though the `length` property is set to `0`. * The `shift()` method is buggy in IE 8 compatibility mode, while `splice()` * is buggy regardless of mode in IE < 9 and buggy in compatibility mode in IE 9. * * @memberOf _.support * @type boolean */ support.spliceObjects = (arrayRef.splice.call(object, 0, 1), !object[0]); }(1)); /** * By default, the template delimiters used by Lo-Dash are similar to those in * embedded Ruby (ERB). Change the following template settings to use alternative * delimiters. * * @static * @memberOf _ * @type Object */ lodash.templateSettings = { /** * Used to detect `data` property values to be HTML-escaped. * * @memberOf _.templateSettings * @type RegExp */ 'escape': /<%-([\s\S]+?)%>/g, /** * Used to detect code to be evaluated. * * @memberOf _.templateSettings * @type RegExp */ 'evaluate': /<%([\s\S]+?)%>/g, /** * Used to detect `data` property values to inject. * * @memberOf _.templateSettings * @type RegExp */ 'interpolate': reInterpolate, /** * Used to reference the data object in the template text. * * @memberOf _.templateSettings * @type string */ 'variable': '' }; /*--------------------------------------------------------------------------*/ /** * The base implementation of `_.bind` that creates the bound function and * sets its meta data. * * @private * @param {Array} bindData The bind data array. * @returns {Function} Returns the new bound function. */ function baseBind(bindData) { var func = bindData[0], partialArgs = bindData[2], thisArg = bindData[4]; function bound() { // `Function#bind` spec // http://es5.github.io/#x15.3.4.5 if (partialArgs) { var args = partialArgs.slice(); push.apply(args, arguments); } // mimic the constructor's `return` behavior // http://es5.github.io/#x13.2.2 if (this instanceof bound) { // ensure `new bound` is an instance of `func` var thisBinding = baseCreate(func.prototype), result = func.apply(thisBinding, args || arguments); return isObject(result) ? result : thisBinding; } return func.apply(thisArg, args || arguments); } return bound; } /** * The base implementation of `_.create` without support for assigning * properties to the created object. * * @private * @param {Object} prototype The object to inherit from. * @returns {Object} Returns the new object. */ function baseCreate(prototype, properties) { return isObject(prototype) ? nativeCreate(prototype) : {}; } // fallback for browsers without `Object.create` if (!nativeCreate) { baseCreate = (function() { function Object() {} return function(prototype) { if (isObject(prototype)) { Object.prototype = prototype; var result = new Object; Object.prototype = null; } return result || root.Object(); }; }()); } /** * The base implementation of `_.createCallback` without support for creating * "_.pluck" or "_.where" style callbacks. * * @private * @param {*} [func=identity] The value to convert to a callback. * @param {*} [thisArg] The `this` binding of the created callback. * @param {number} [argCount] The number of arguments the callback accepts. * @returns {Function} Returns a callback function. */ function baseCreateCallback(func, thisArg, argCount) { if (typeof func != 'function') { return identity; } // exit early for no `thisArg` or already bound by `Function#bind` if (typeof thisArg == 'undefined' || !('prototype' in func)) { return func; } switch (argCount) { case 1: return function(value) { return func.call(thisArg, value); }; case 2: return function(a, b) { return func.call(thisArg, a, b); }; case 3: return function(value, index, collection) { return func.call(thisArg, value, index, collection); }; case 4: return function(accumulator, value, index, collection) { return func.call(thisArg, accumulator, value, index, collection); }; } return bind(func, thisArg); } /** * The base implementation of `createWrapper` that creates the wrapper and * sets its meta data. * * @private * @param {Array} bindData The bind data array. * @returns {Function} Returns the new function. */ function baseCreateWrapper(bindData) { var func = bindData[0], bitmask = bindData[1], partialArgs = bindData[2], partialRightArgs = bindData[3], thisArg = bindData[4], arity = bindData[5]; var isBind = bitmask & 1, isBindKey = bitmask & 2, isCurry = bitmask & 4, isCurryBound = bitmask & 8, key = func; function bound() { var thisBinding = isBind ? thisArg : this; if (partialArgs) { var args = partialArgs.slice(); push.apply(args, arguments); } if (partialRightArgs || isCurry) { args || (args = slice(arguments)); if (partialRightArgs) { push.apply(args, partialRightArgs); } if (isCurry && args.length < arity) { bitmask |= 16 & ~32; return baseCreateWrapper([func, (isCurryBound ? bitmask : bitmask & ~3), args, null, thisArg, arity]); } } args || (args = arguments); if (isBindKey) { func = thisBinding[key]; } if (this instanceof bound) { thisBinding = baseCreate(func.prototype); var result = func.apply(thisBinding, args); return isObject(result) ? result : thisBinding; } return func.apply(thisBinding, args); } return bound; } /** * The base implementation of `_.difference` that accepts a single array * of values to exclude. * * @private * @param {Array} array The array to process. * @param {Array} [values] The array of values to exclude. * @returns {Array} Returns a new array of filtered values. */ function baseDifference(array, values) { var index = -1, indexOf = getIndexOf(), length = array ? array.length : 0, result = []; while (++index < length) { var value = array[index]; if (indexOf(values, value) < 0) { result.push(value); } } return result; } /** * The base implementation of `_.flatten` without support for callback * shorthands or `thisArg` binding. * * @private * @param {Array} array The array to flatten. * @param {boolean} [isShallow=false] A flag to restrict flattening to a single level. * @param {boolean} [isStrict=false] A flag to restrict flattening to arrays and `arguments` objects. * @param {number} [fromIndex=0] The index to start from. * @returns {Array} Returns a new flattened array. */ function baseFlatten(array, isShallow, isStrict, fromIndex) { var index = (fromIndex || 0) - 1, length = array ? array.length : 0, result = []; while (++index < length) { var value = array[index]; if (value && typeof value == 'object' && typeof value.length == 'number' && (isArray(value) || isArguments(value))) { // recursively flatten arrays (susceptible to call stack limits) if (!isShallow) { value = baseFlatten(value, isShallow, isStrict); } var valIndex = -1, valLength = value.length, resIndex = result.length; result.length += valLength; while (++valIndex < valLength) { result[resIndex++] = value[valIndex]; } } else if (!isStrict) { result.push(value); } } return result; } /** * The base implementation of `_.isEqual`, without support for `thisArg` binding, * that allows partial "_.where" style comparisons. * * @private * @param {*} a The value to compare. * @param {*} b The other value to compare. * @param {Function} [callback] The function to customize comparing values. * @param {Function} [isWhere=false] A flag to indicate performing partial comparisons. * @param {Array} [stackA=[]] Tracks traversed `a` objects. * @param {Array} [stackB=[]] Tracks traversed `b` objects. * @returns {boolean} Returns `true` if the values are equivalent, else `false`. */ function baseIsEqual(a, b, stackA, stackB) { if (a === b) { return a !== 0 || (1 / a == 1 / b); } var type = typeof a, otherType = typeof b; if (a === a && !(a && objectTypes[type]) && !(b && objectTypes[otherType])) { return false; } if (a == null || b == null) { return a === b; } var className = toString.call(a), otherClass = toString.call(b); if (className != otherClass) { return false; } switch (className) { case boolClass: case dateClass: return +a == +b; case numberClass: return a != +a ? b != +b : (a == 0 ? (1 / a == 1 / b) : a == +b); case regexpClass: case stringClass: return a == String(b); } var isArr = className == arrayClass; if (!isArr) { var aWrapped = a instanceof lodash, bWrapped = b instanceof lodash; if (aWrapped || bWrapped) { return baseIsEqual(aWrapped ? a.__wrapped__ : a, bWrapped ? b.__wrapped__ : b, stackA, stackB); } if (className != objectClass) { return false; } var ctorA = a.constructor, ctorB = b.constructor; if (ctorA != ctorB && !(isFunction(ctorA) && ctorA instanceof ctorA && isFunction(ctorB) && ctorB instanceof ctorB) && ('constructor' in a && 'constructor' in b) ) { return false; } } stackA || (stackA = []); stackB || (stackB = []); var length = stackA.length; while (length--) { if (stackA[length] == a) { return stackB[length] == b; } } var result = true, size = 0; stackA.push(a); stackB.push(b); if (isArr) { size = b.length; result = size == a.length; if (result) { while (size--) { if (!(result = baseIsEqual(a[size], b[size], stackA, stackB))) { break; } } } return result; } forIn(b, function(value, key, b) { if (hasOwnProperty.call(b, key)) { size++; return !(result = hasOwnProperty.call(a, key) && baseIsEqual(a[key], value, stackA, stackB)) && indicatorObject; } }); if (result) { forIn(a, function(value, key, a) { if (hasOwnProperty.call(a, key)) { return !(result = --size > -1) && indicatorObject; } }); } return result; } /** * The base implementation of `_.random` without argument juggling or support * for returning floating-point numbers. * * @private * @param {number} min The minimum possible value. * @param {number} max The maximum possible value. * @returns {number} Returns a random number. */ function baseRandom(min, max) { return min + floor(nativeRandom() * (max - min + 1)); } /** * The base implementation of `_.uniq` without support for callback shorthands * or `thisArg` binding. * * @private * @param {Array} array The array to process. * @param {boolean} [isSorted=false] A flag to indicate that `array` is sorted. * @param {Function} [callback] The function called per iteration. * @returns {Array} Returns a duplicate-value-free array. */ function baseUniq(array, isSorted, callback) { var index = -1, indexOf = getIndexOf(), length = array ? array.length : 0, result = [], seen = callback ? [] : result; while (++index < length) { var value = array[index], computed = callback ? callback(value, index, array) : value; if (isSorted ? !index || seen[seen.length - 1] !== computed : indexOf(seen, computed) < 0 ) { if (callback) { seen.push(computed); } result.push(value); } } return result; } /** * Creates a function that aggregates a collection, creating an object composed * of keys generated from the results of running each element of the collection * through a callback. The given `setter` function sets the keys and values * of the composed object. * * @private * @param {Function} setter The setter function. * @returns {Function} Returns the new aggregator function. */ function createAggregator(setter) { return function(collection, callback, thisArg) { var result = {}; callback = createCallback(callback, thisArg, 3); var index = -1, length = collection ? collection.length : 0; if (typeof length == 'number') { while (++index < length) { var value = collection[index]; setter(result, value, callback(value, index, collection), collection); } } else { forOwn(collection, function(value, key, collection) { setter(result, value, callback(value, key, collection), collection); }); } return result; }; } /** * Creates a function that, when called, either curries or invokes `func` * with an optional `this` binding and partially applied arguments. * * @private * @param {Function|string} func The function or method name to reference. * @param {number} bitmask The bitmask of method flags to compose. * The bitmask may be composed of the following flags: * 1 - `_.bind` * 2 - `_.bindKey` * 4 - `_.curry` * 8 - `_.curry` (bound) * 16 - `_.partial` * 32 - `_.partialRight` * @param {Array} [partialArgs] An array of arguments to prepend to those * provided to the new function. * @param {Array} [partialRightArgs] An array of arguments to append to those * provided to the new function. * @param {*} [thisArg] The `this` binding of `func`. * @param {number} [arity] The arity of `func`. * @returns {Function} Returns the new function. */ function createWrapper(func, bitmask, partialArgs, partialRightArgs, thisArg, arity) { var isBind = bitmask & 1, isBindKey = bitmask & 2, isCurry = bitmask & 4, isCurryBound = bitmask & 8, isPartial = bitmask & 16, isPartialRight = bitmask & 32; if (!isBindKey && !isFunction(func)) { throw new TypeError; } if (isPartial && !partialArgs.length) { bitmask &= ~16; isPartial = partialArgs = false; } if (isPartialRight && !partialRightArgs.length) { bitmask &= ~32; isPartialRight = partialRightArgs = false; } // fast path for `_.bind` var creater = (bitmask == 1 || bitmask === 17) ? baseBind : baseCreateWrapper; return creater([func, bitmask, partialArgs, partialRightArgs, thisArg, arity]); } /** * Used by `escape` to convert characters to HTML entities. * * @private * @param {string} match The matched character to escape. * @returns {string} Returns the escaped character. */ function escapeHtmlChar(match) { return htmlEscapes[match]; } /** * Gets the appropriate "indexOf" function. If the `_.indexOf` method is * customized, this method returns the custom method, otherwise it returns * the `baseIndexOf` function. * * @private * @returns {Function} Returns the "indexOf" function. */ function getIndexOf() { var result = (result = lodash.indexOf) === indexOf ? baseIndexOf : result; return result; } /** * Used by `unescape` to convert HTML entities to characters. * * @private * @param {string} match The matched character to unescape. * @returns {string} Returns the unescaped character. */ function unescapeHtmlChar(match) { return htmlUnescapes[match]; } /*--------------------------------------------------------------------------*/ /** * Checks if `value` is an `arguments` object. * * @static * @memberOf _ * @category Objects * @param {*} value The value to check. * @returns {boolean} Returns `true` if the `value` is an `arguments` object, else `false`. * @example * * (function() { return _.isArguments(arguments); })(1, 2, 3); * // => true * * _.isArguments([1, 2, 3]); * // => false */ function isArguments(value) { return value && typeof value == 'object' && typeof value.length == 'number' && toString.call(value) == argsClass || false; } // fallback for browsers that can't detect `arguments` objects by [[Class]] if (!isArguments(arguments)) { isArguments = function(value) { return value && typeof value == 'object' && typeof value.length == 'number' && hasOwnProperty.call(value, 'callee') && !propertyIsEnumerable.call(value, 'callee') || false; }; } /** * Checks if `value` is an array. * * @static * @memberOf _ * @type Function * @category Objects * @param {*} value The value to check. * @returns {boolean} Returns `true` if the `value` is an array, else `false`. * @example * * (function() { return _.isArray(arguments); })(); * // => false * * _.isArray([1, 2, 3]); * // => true */ var isArray = nativeIsArray || function(value) { return value && typeof value == 'object' && typeof value.length == 'number' && toString.call(value) == arrayClass || false; }; /** * A fallback implementation of `Object.keys` which produces an array of the * given object's own enumerable property names. * * @private * @type Function * @param {Object} object The object to inspect. * @returns {Array} Returns an array of property names. */ var shimKeys = function(object) { var index, iterable = object, result = []; if (!iterable) return result; if (!(objectTypes[typeof object])) return result; for (index in iterable) { if (hasOwnProperty.call(iterable, index)) { result.push(index); } } return result }; /** * Creates an array composed of the own enumerable property names of an object. * * @static * @memberOf _ * @category Objects * @param {Object} object The object to inspect. * @returns {Array} Returns an array of property names. * @example * * _.keys({ 'one': 1, 'two': 2, 'three': 3 }); * // => ['one', 'two', 'three'] (property order is not guaranteed across environments) */ var keys = !nativeKeys ? shimKeys : function(object) { if (!isObject(object)) { return []; } return nativeKeys(object); }; /** * Used to convert characters to HTML entities: * * Though the `>` character is escaped for symmetry, characters like `>` and `/` * don't require escaping in HTML and have no special meaning unless they're part * of a tag or an unquoted attribute value. * http://mathiasbynens.be/notes/ambiguous-ampersands (under "semi-related fun fact") */ var htmlEscapes = { '&': '&', '<': '<', '>': '>', '"': '"', "'": ''' }; /** Used to convert HTML entities to characters */ var htmlUnescapes = invert(htmlEscapes); /** Used to match HTML entities and HTML characters */ var reEscapedHtml = RegExp('(' + keys(htmlUnescapes).join('|') + ')', 'g'), reUnescapedHtml = RegExp('[' + keys(htmlEscapes).join('') + ']', 'g'); /*--------------------------------------------------------------------------*/ /** * Assigns own enumerable properties of source object(s) to the destination * object. Subsequent sources will overwrite property assignments of previous * sources. If a callback is provided it will be executed to produce the * assigned values. The callback is bound to `thisArg` and invoked with two * arguments; (objectValue, sourceValue). * * @static * @memberOf _ * @type Function * @alias extend * @category Objects * @param {Object} object The destination object. * @param {...Object} [source] The source objects. * @param {Function} [callback] The function to customize assigning values. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {Object} Returns the destination object. * @example * * _.assign({ 'name': 'fred' }, { 'employer': 'slate' }); * // => { 'name': 'fred', 'employer': 'slate' } * * var defaults = _.partialRight(_.assign, function(a, b) { * return typeof a == 'undefined' ? b : a; * }); * * var object = { 'name': 'barney' }; * defaults(object, { 'name': 'fred', 'employer': 'slate' }); * // => { 'name': 'barney', 'employer': 'slate' } */ function assign(object) { if (!object) { return object; } for (var argsIndex = 1, argsLength = arguments.length; argsIndex < argsLength; argsIndex++) { var iterable = arguments[argsIndex]; if (iterable) { for (var key in iterable) { object[key] = iterable[key]; } } } return object; } /** * Creates a clone of `value`. If `isDeep` is `true` nested objects will also * be cloned, otherwise they will be assigned by reference. If a callback * is provided it will be executed to produce the cloned values. If the * callback returns `undefined` cloning will be handled by the method instead. * The callback is bound to `thisArg` and invoked with one argument; (value). * * @static * @memberOf _ * @category Objects * @param {*} value The value to clone. * @param {boolean} [isDeep=false] Specify a deep clone. * @param {Function} [callback] The function to customize cloning values. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {*} Returns the cloned value. * @example * * var characters = [ * { 'name': 'barney', 'age': 36 }, * { 'name': 'fred', 'age': 40 } * ]; * * var shallow = _.clone(characters); * shallow[0] === characters[0]; * // => true * * var deep = _.clone(characters, true); * deep[0] === characters[0]; * // => false * * _.mixin({ * 'clone': _.partialRight(_.clone, function(value) { * return _.isElement(value) ? value.cloneNode(false) : undefined; * }) * }); * * var clone = _.clone(document.body); * clone.childNodes.length; * // => 0 */ function clone(value) { return isObject(value) ? (isArray(value) ? slice(value) : assign({}, value)) : value; } /** * Assigns own enumerable properties of source object(s) to the destination * object for all destination properties that resolve to `undefined`. Once a * property is set, additional defaults of the same property will be ignored. * * @static * @memberOf _ * @type Function * @category Objects * @param {Object} object The destination object. * @param {...Object} [source] The source objects. * @param- {Object} [guard] Allows working with `_.reduce` without using its * `key` and `object` arguments as sources. * @returns {Object} Returns the destination object. * @example * * var object = { 'name': 'barney' }; * _.defaults(object, { 'name': 'fred', 'employer': 'slate' }); * // => { 'name': 'barney', 'employer': 'slate' } */ function defaults(object) { if (!object) { return object; } for (var argsIndex = 1, argsLength = arguments.length; argsIndex < argsLength; argsIndex++) { var iterable = arguments[argsIndex]; if (iterable) { for (var key in iterable) { if (typeof object[key] == 'undefined') { object[key] = iterable[key]; } } } } return object; } /** * Iterates over own and inherited enumerable properties of an object, * executing the callback for each property. The callback is bound to `thisArg` * and invoked with three arguments; (value, key, object). Callbacks may exit * iteration early by explicitly returning `false`. * * @static * @memberOf _ * @type Function * @category Objects * @param {Object} object The object to iterate over. * @param {Function} [callback=identity] The function called per iteration. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {Object} Returns `object`. * @example * * function Shape() { * this.x = 0; * this.y = 0; * } * * Shape.prototype.move = function(x, y) { * this.x += x; * this.y += y; * }; * * _.forIn(new Shape, function(value, key) { * console.log(key); * }); * // => logs 'x', 'y', and 'move' (property order is not guaranteed across environments) */ var forIn = function(collection, callback) { var index, iterable = collection, result = iterable; if (!iterable) return result; if (!objectTypes[typeof iterable]) return result; for (index in iterable) { if (callback(iterable[index], index, collection) === indicatorObject) return result; } return result }; /** * Iterates over own enumerable properties of an object, executing the callback * for each property. The callback is bound to `thisArg` and invoked with three * arguments; (value, key, object). Callbacks may exit iteration early by * explicitly returning `false`. * * @static * @memberOf _ * @type Function * @category Objects * @param {Object} object The object to iterate over. * @param {Function} [callback=identity] The function called per iteration. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {Object} Returns `object`. * @example * * _.forOwn({ '0': 'zero', '1': 'one', 'length': 2 }, function(num, key) { * console.log(key); * }); * // => logs '0', '1', and 'length' (property order is not guaranteed across environments) */ var forOwn = function(collection, callback) { var index, iterable = collection, result = iterable; if (!iterable) return result; if (!objectTypes[typeof iterable]) return result; for (index in iterable) { if (hasOwnProperty.call(iterable, index)) { if (callback(iterable[index], index, collection) === indicatorObject) return result; } } return result }; /** * Creates a sorted array of property names of all enumerable properties, * own and inherited, of `object` that have function values. * * @static * @memberOf _ * @alias methods * @category Objects * @param {Object} object The object to inspect. * @returns {Array} Returns an array of property names that have function values. * @example * * _.functions(_); * // => ['all', 'any', 'bind', 'bindAll', 'clone', 'compact', 'compose', ...] */ function functions(object) { var result = []; forIn(object, function(value, key) { if (isFunction(value)) { result.push(key); } }); return result.sort(); } /** * Checks if the specified 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': 'fred', 'second': 'barney' }); * // => { 'fred': 'first', 'barney': 'second' } */ function invert(object) { var index = -1, props = keys(object), length = props.length, result = {}; while (++index < length) { var key = props[index]; result[object[key]] = key; } return result; } /** * Checks if `value` is a boolean value. * * @static * @memberOf _ * @category Objects * @param {*} value The value to check. * @returns {boolean} Returns `true` if the `value` is a boolean value, else `false`. * @example * * _.isBoolean(null); * // => false */ function isBoolean(value) { return value === true || value === false || value && typeof value == 'object' && toString.call(value) == boolClass || false; } /** * Checks if `value` is a date. * * @static * @memberOf _ * @category Objects * @param {*} value The value to check. * @returns {boolean} Returns `true` if the `value` is a date, else `false`. * @example * * _.isDate(new Date); * // => true */ function isDate(value) { return value && typeof value == 'object' && toString.call(value) == dateClass || false; } /** * Checks if `value` is a DOM element. * * @static * @memberOf _ * @category Objects * @param {*} value The value to check. * @returns {boolean} Returns `true` if the `value` is a DOM element, else `false`. * @example * * _.isElement(document.body); * // => true */ function isElement(value) { return value && value.nodeType === 1 || false; } /** * Checks if `value` is empty. Arrays, strings, or `arguments` objects with a * length of `0` and objects with no own enumerable properties are considered * "empty". * * @static * @memberOf _ * @category Objects * @param {Array|Object|string} value The value to inspect. * @returns {boolean} Returns `true` if the `value` is empty, else `false`. * @example * * _.isEmpty([1, 2, 3]); * // => false * * _.isEmpty({}); * // => true * * _.isEmpty(''); * // => true */ function isEmpty(value) { if (!value) { return true; } if (isArray(value) || isString(value)) { return !value.length; } for (var key in value) { if (hasOwnProperty.call(value, key)) { return false; } } return true; } /** * Performs a deep comparison between two values to determine if they are * equivalent to each other. If a callback is provided it will be executed * to compare values. If the callback returns `undefined` comparisons will * be handled by the method instead. The callback is bound to `thisArg` and * invoked with two arguments; (a, b). * * @static * @memberOf _ * @category Objects * @param {*} a The value to compare. * @param {*} b The other value to compare. * @param {Function} [callback] The function to customize comparing values. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {boolean} Returns `true` if the values are equivalent, else `false`. * @example * * var object = { 'name': 'fred' }; * var copy = { 'name': 'fred' }; * * object == copy; * // => false * * _.isEqual(object, copy); * // => true * * var words = ['hello', 'goodbye']; * var otherWords = ['hi', 'goodbye']; * * _.isEqual(words, otherWords, function(a, b) { * var reGreet = /^(?:hello|hi)$/i, * aGreet = _.isString(a) && reGreet.test(a), * bGreet = _.isString(b) && reGreet.test(b); * * return (aGreet || bGreet) ? (aGreet == bGreet) : undefined; * }); * // => true */ function isEqual(a, b) { return baseIsEqual(a, b); } /** * Checks if `value` is, or can be coerced to, a finite number. * * Note: This is not the same as native `isFinite` which will return true for * booleans and empty strings. See http://es5.github.io/#x15.1.2.5. * * @static * @memberOf _ * @category Objects * @param {*} value The value to check. * @returns {boolean} Returns `true` if the `value` is finite, else `false`. * @example * * _.isFinite(-101); * // => true * * _.isFinite('10'); * // => true * * _.isFinite(true); * // => false * * _.isFinite(''); * // => false * * _.isFinite(Infinity); * // => false */ function isFinite(value) { return nativeIsFinite(value) && !nativeIsNaN(parseFloat(value)); } /** * Checks if `value` is a function. * * @static * @memberOf _ * @category Objects * @param {*} value The value to check. * @returns {boolean} Returns `true` if the `value` is a function, else `false`. * @example * * _.isFunction(_); * // => true */ function isFunction(value) { return typeof value == 'function'; } // fallback for older versions of Chrome and Safari if (isFunction(/x/)) { isFunction = function(value) { return typeof value == 'function' && toString.call(value) == funcClass; }; } /** * Checks if `value` is the language type of Object. * (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`) * * @static * @memberOf _ * @category Objects * @param {*} value The value to check. * @returns {boolean} Returns `true` if the `value` is an object, else `false`. * @example * * _.isObject({}); * // => true * * _.isObject([1, 2, 3]); * // => true * * _.isObject(1); * // => false */ function isObject(value) { // check if the value is the ECMAScript language type of Object // http://es5.github.io/#x8 // and avoid a V8 bug // http://code.google.com/p/v8/issues/detail?id=2291 return !!(value && objectTypes[typeof value]); } /** * Checks if `value` is `NaN`. * * Note: This is not the same as native `isNaN` which will return `true` for * `undefined` and other non-numeric values. See http://es5.github.io/#x15.1.2.4. * * @static * @memberOf _ * @category Objects * @param {*} value The value to check. * @returns {boolean} Returns `true` if the `value` is `NaN`, else `false`. * @example * * _.isNaN(NaN); * // => true * * _.isNaN(new Number(NaN)); * // => true * * isNaN(undefined); * // => true * * _.isNaN(undefined); * // => false */ function isNaN(value) { // `NaN` as a primitive is the only value that is not equal to itself // (perform the [[Class]] check first to avoid errors with some host objects in IE) return isNumber(value) && value != +value; } /** * Checks if `value` is `null`. * * @static * @memberOf _ * @category Objects * @param {*} value The value to check. * @returns {boolean} Returns `true` if the `value` is `null`, else `false`. * @example * * _.isNull(null); * // => true * * _.isNull(undefined); * // => false */ function isNull(value) { return value === null; } /** * Checks if `value` is a number. * * Note: `NaN` is considered a number. See http://es5.github.io/#x8.5. * * @static * @memberOf _ * @category Objects * @param {*} value The value to check. * @returns {boolean} Returns `true` if the `value` is a number, else `false`. * @example * * _.isNumber(8.4 * 5); * // => true */ function isNumber(value) { return typeof value == 'number' || value && typeof value == 'object' && toString.call(value) == numberClass || false; } /** * Checks if `value` is a regular expression. * * @static * @memberOf _ * @category Objects * @param {*} value The value to check. * @returns {boolean} Returns `true` if the `value` is a regular expression, else `false`. * @example * * _.isRegExp(/fred/); * // => true */ function isRegExp(value) { return value && objectTypes[typeof value] && toString.call(value) == regexpClass || false; } /** * Checks if `value` is a string. * * @static * @memberOf _ * @category Objects * @param {*} value The value to check. * @returns {boolean} Returns `true` if the `value` is a string, else `false`. * @example * * _.isString('fred'); * // => true */ function isString(value) { return typeof value == 'string' || value && typeof value == 'object' && toString.call(value) == stringClass || false; } /** * Checks if `value` is `undefined`. * * @static * @memberOf _ * @category Objects * @param {*} value The value to check. * @returns {boolean} Returns `true` if the `value` is `undefined`, else `false`. * @example * * _.isUndefined(void 0); * // => true */ function isUndefined(value) { return typeof value == 'undefined'; } /** * Creates a shallow clone of `object` excluding the specified properties. * Property names may be specified as individual arguments or as arrays of * property names. If a callback is provided it will be executed for each * property of `object` omitting the properties the callback returns truey * for. The callback is bound to `thisArg` and invoked with three arguments; * (value, key, object). * * @static * @memberOf _ * @category Objects * @param {Object} object The source object. * @param {Function|...string|string[]} [callback] The properties to omit or the * function called per iteration. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {Object} Returns an object without the omitted properties. * @example * * _.omit({ 'name': 'fred', 'age': 40 }, 'age'); * // => { 'name': 'fred' } * * _.omit({ 'name': 'fred', 'age': 40 }, function(value) { * return typeof value == 'number'; * }); * // => { 'name': 'fred' } */ function omit(object) { var props = []; forIn(object, function(value, key) { props.push(key); }); props = baseDifference(props, baseFlatten(arguments, true, false, 1)); var index = -1, length = props.length, result = {}; while (++index < length) { var key = props[index]; result[key] = object[key]; } return result; } /** * Creates a two dimensional array of an object's key-value pairs, * i.e. `[[key1, value1], [key2, value2]]`. * * @static * @memberOf _ * @category Objects * @param {Object} object The object to inspect. * @returns {Array} Returns new array of key-value pairs. * @example * * _.pairs({ 'barney': 36, 'fred': 40 }); * // => [['barney', 36], ['fred', 40]] (property order is not guaranteed across environments) */ function pairs(object) { var index = -1, props = keys(object), length = props.length, result = Array(length); while (++index < length) { var key = props[index]; result[index] = [key, object[key]]; } return result; } /** * Creates a shallow clone of `object` composed of the specified properties. * Property names may be specified as individual arguments or as arrays of * property names. If a callback is provided it will be executed for each * property of `object` picking the properties the callback returns truey * for. The callback is bound to `thisArg` and invoked with three arguments; * (value, key, object). * * @static * @memberOf _ * @category Objects * @param {Object} object The source object. * @param {Function|...string|string[]} [callback] The function called per * iteration or property names to pick, specified as individual property * names or arrays of property names. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {Object} Returns an object composed of the picked properties. * @example * * _.pick({ 'name': 'fred', '_userid': 'fred1' }, 'name'); * // => { 'name': 'fred' } * * _.pick({ 'name': 'fred', '_userid': 'fred1' }, function(value, key) { * return key.charAt(0) != '_'; * }); * // => { 'name': 'fred' } */ function pick(object) { var index = -1, props = baseFlatten(arguments, true, false, 1), length = props.length, result = {}; while (++index < length) { var key = props[index]; if (key in object) { result[key] = object[key]; } } return result; } /** * Creates an array composed of the own enumerable property values of `object`. * * @static * @memberOf _ * @category Objects * @param {Object} object The object to inspect. * @returns {Array} Returns an array of property values. * @example * * _.values({ 'one': 1, 'two': 2, 'three': 3 }); * // => [1, 2, 3] (property order is not guaranteed across environments) */ function values(object) { var index = -1, props = keys(object), length = props.length, result = Array(length); while (++index < length) { result[index] = object[props[index]]; } return result; } /*--------------------------------------------------------------------------*/ /** * Checks if a given value is present in a collection using strict equality * for comparisons, i.e. `===`. If `fromIndex` is negative, it is used as the * offset from the end of the collection. * * @static * @memberOf _ * @alias include * @category Collections * @param {Array|Object|string} collection The collection to iterate over. * @param {*} target The value to check for. * @param {number} [fromIndex=0] The index to search from. * @returns {boolean} Returns `true` if the `target` element is found, else `false`. * @example * * _.contains([1, 2, 3], 1); * // => true * * _.contains([1, 2, 3], 1, 2); * // => false * * _.contains({ 'name': 'fred', 'age': 40 }, 'fred'); * // => true * * _.contains('pebbles', 'eb'); * // => true */ function contains(collection, target) { var indexOf = getIndexOf(), length = collection ? collection.length : 0, result = false; if (length && typeof length == 'number') { result = indexOf(collection, target) > -1; } else { forOwn(collection, function(value) { return (result = value === target) && indicatorObject; }); } return result; } /** * Creates an object composed of keys generated from the results of running * each element of `collection` through the callback. The corresponding value * of each key is the number of times the key was returned by the callback. * The callback is bound to `thisArg` and invoked with three arguments; * (value, index|key, collection). * * If a property name is provided for `callback` the created "_.pluck" style * callback will return the property value of the given element. * * If an object is provided for `callback` the created "_.where" style callback * will return `true` for elements that have the properties of the given object, * else `false`. * * @static * @memberOf _ * @category Collections * @param {Array|Object|string} collection The collection to iterate over. * @param {Function|Object|string} [callback=identity] The function called * per iteration. If a property name or object is provided it will be used * to create a "_.pluck" or "_.where" style callback, respectively. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {Object} Returns the composed aggregate object. * @example * * _.countBy([4.3, 6.1, 6.4], function(num) { return Math.floor(num); }); * // => { '4': 1, '6': 2 } * * _.countBy([4.3, 6.1, 6.4], function(num) { return this.floor(num); }, Math); * // => { '4': 1, '6': 2 } * * _.countBy(['one', 'two', 'three'], 'length'); * // => { '3': 2, '5': 1 } */ var countBy = createAggregator(function(result, value, key) { (hasOwnProperty.call(result, key) ? result[key]++ : result[key] = 1); }); /** * Checks if the given callback returns truey value for **all** elements of * a collection. The callback is bound to `thisArg` and invoked with three * arguments; (value, index|key, collection). * * If a property name is provided for `callback` the created "_.pluck" style * callback will return the property value of the given element. * * If an object is provided for `callback` the created "_.where" style callback * will return `true` for elements that have the properties of the given object, * else `false`. * * @static * @memberOf _ * @alias all * @category Collections * @param {Array|Object|string} collection The collection to iterate over. * @param {Function|Object|string} [callback=identity] The function called * per iteration. If a property name or object is provided it will be used * to create a "_.pluck" or "_.where" style callback, respectively. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {boolean} Returns `true` if all elements passed the callback check, * else `false`. * @example * * _.every([true, 1, null, 'yes']); * // => false * * var characters = [ * { 'name': 'barney', 'age': 36 }, * { 'name': 'fred', 'age': 40 } * ]; * * // using "_.pluck" callback shorthand * _.every(characters, 'age'); * // => true * * // using "_.where" callback shorthand * _.every(characters, { 'age': 36 }); * // => false */ function every(collection, callback, thisArg) { var result = true; callback = createCallback(callback, thisArg, 3); var index = -1, length = collection ? collection.length : 0; if (typeof length == 'number') { while (++index < length) { if (!(result = !!callback(collection[index], index, collection))) { break; } } } else { forOwn(collection, function(value, index, collection) { return !(result = !!callback(value, index, collection)) && indicatorObject; }); } return result; } /** * Iterates over elements of a collection, returning an array of all elements * the callback returns truey for. The callback is bound to `thisArg` and * invoked with three arguments; (value, index|key, collection). * * If a property name is provided for `callback` the created "_.pluck" style * callback will return the property value of the given element. * * If an object is provided for `callback` the created "_.where" style callback * will return `true` for elements that have the properties of the given object, * else `false`. * * @static * @memberOf _ * @alias select * @category Collections * @param {Array|Object|string} collection The collection to iterate over. * @param {Function|Object|string} [callback=identity] The function called * per iteration. If a property name or object is provided it will be used * to create a "_.pluck" or "_.where" style callback, respectively. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {Array} Returns a new array of elements that passed the callback check. * @example * * var evens = _.filter([1, 2, 3, 4, 5, 6], function(num) { return num % 2 == 0; }); * // => [2, 4, 6] * * var characters = [ * { 'name': 'barney', 'age': 36, 'blocked': false }, * { 'name': 'fred', 'age': 40, 'blocked': true } * ]; * * // using "_.pluck" callback shorthand * _.filter(characters, 'blocked'); * // => [{ 'name': 'fred', 'age': 40, 'blocked': true }] * * // using "_.where" callback shorthand * _.filter(characters, { 'age': 36 }); * // => [{ 'name': 'barney', 'age': 36, 'blocked': false }] */ function filter(collection, callback, thisArg) { var result = []; callback = createCallback(callback, thisArg, 3); var index = -1, length = collection ? collection.length : 0; if (typeof length == 'number') { while (++index < length) { var value = collection[index]; if (callback(value, index, collection)) { result.push(value); } } } else { forOwn(collection, function(value, index, collection) { if (callback(value, index, collection)) { result.push(value); } }); } return result; } /** * Iterates over elements of a collection, returning the first element that * the callback returns truey for. The callback is bound to `thisArg` and * invoked with three arguments; (value, index|key, collection). * * If a property name is provided for `callback` the created "_.pluck" style * callback will return the property value of the given element. * * If an object is provided for `callback` the created "_.where" style callback * will return `true` for elements that have the properties of the given object, * else `false`. * * @static * @memberOf _ * @alias detect, findWhere * @category Collections * @param {Array|Object|string} collection The collection to iterate over. * @param {Function|Object|string} [callback=identity] The function called * per iteration. If a property name or object is provided it will be used * to create a "_.pluck" or "_.where" style callback, respectively. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {*} Returns the found element, else `undefined`. * @example * * var characters = [ * { 'name': 'barney', 'age': 36, 'blocked': false }, * { 'name': 'fred', 'age': 40, 'blocked': true }, * { 'name': 'pebbles', 'age': 1, 'blocked': false } * ]; * * _.find(characters, function(chr) { * return chr.age < 40; * }); * // => { 'name': 'barney', 'age': 36, 'blocked': false } * * // using "_.where" callback shorthand * _.find(characters, { 'age': 1 }); * // => { 'name': 'pebbles', 'age': 1, 'blocked': false } * * // using "_.pluck" callback shorthand * _.find(characters, 'blocked'); * // => { 'name': 'fred', 'age': 40, 'blocked': true } */ function find(collection, callback, thisArg) { callback = createCallback(callback, thisArg, 3); var index = -1, length = collection ? collection.length : 0; if (typeof length == 'number') { while (++index < length) { var value = collection[index]; if (callback(value, index, collection)) { return value; } } } else { var result; forOwn(collection, function(value, index, collection) { if (callback(value, index, collection)) { result = value; return indicatorObject; } }); return result; } } /** * Examines each element in a `collection`, returning the first that * has the given properties. When checking `properties`, this method * performs a deep comparison between values to determine if they are * equivalent to each other. * * @static * @memberOf _ * @category Collections * @param {Array|Object|string} collection The collection to iterate over. * @param {Object} properties The object of property values to filter by. * @returns {*} Returns the found element, else `undefined`. * @example * * var food = [ * { 'name': 'apple', 'organic': false, 'type': 'fruit' }, * { 'name': 'banana', 'organic': true, 'type': 'fruit' }, * { 'name': 'beet', 'organic': false, 'type': 'vegetable' } * ]; * * _.findWhere(food, { 'type': 'vegetable' }); * // => { 'name': 'beet', 'organic': false, 'type': 'vegetable' } */ function findWhere(object, properties) { return where(object, properties, true); } /** * Iterates over elements of a collection, executing the callback for each * element. The callback is bound to `thisArg` and invoked with three arguments; * (value, index|key, collection). Callbacks may exit iteration early by * explicitly returning `false`. * * Note: As with other "Collections" methods, objects with a `length` property * are iterated like arrays. To avoid this behavior `_.forIn` or `_.forOwn` * may be used for object iteration. * * @static * @memberOf _ * @alias each * @category Collections * @param {Array|Object|string} collection The collection to iterate over. * @param {Function} [callback=identity] The function called per iteration. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {Array|Object|string} Returns `collection`. * @example * * _([1, 2, 3]).forEach(function(num) { console.log(num); }).join(','); * // => logs each number and returns '1,2,3' * * _.forEach({ 'one': 1, 'two': 2, 'three': 3 }, function(num) { console.log(num); }); * // => logs each number and returns the object (property order is not guaranteed across environments) */ function forEach(collection, callback, thisArg) { var index = -1, length = collection ? collection.length : 0; callback = callback && typeof thisArg == 'undefined' ? callback : baseCreateCallback(callback, thisArg, 3); if (typeof length == 'number') { while (++index < length) { if (callback(collection[index], index, collection) === indicatorObject) { break; } } } else { forOwn(collection, callback); } } /** * This method is like `_.forEach` except that it iterates over elements * of a `collection` from right to left. * * @static * @memberOf _ * @alias eachRight * @category Collections * @param {Array|Object|string} collection The collection to iterate over. * @param {Function} [callback=identity] The function called per iteration. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {Array|Object|string} Returns `collection`. * @example * * _([1, 2, 3]).forEachRight(function(num) { console.log(num); }).join(','); * // => logs each number from right to left and returns '3,2,1' */ function forEachRight(collection, callback) { var length = collection ? collection.length : 0; if (typeof length == 'number') { while (length--) { if (callback(collection[length], length, collection) === false) { break; } } } else { var props = keys(collection); length = props.length; forOwn(collection, function(value, key, collection) { key = props ? props[--length] : --length; return callback(collection[key], key, collection) === false && indicatorObject; }); } } /** * Creates an object composed of keys generated from the results of running * each element of a collection through the callback. The corresponding value * of each key is an array of the elements responsible for generating the key. * The callback is bound to `thisArg` and invoked with three arguments; * (value, index|key, collection). * * If a property name is provided for `callback` the created "_.pluck" style * callback will return the property value of the given element. * * If an object is provided for `callback` the created "_.where" style callback * will return `true` for elements that have the properties of the given object, * else `false` * * @static * @memberOf _ * @category Collections * @param {Array|Object|string} collection The collection to iterate over. * @param {Function|Object|string} [callback=identity] The function called * per iteration. If a property name or object is provided it will be used * to create a "_.pluck" or "_.where" style callback, respectively. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {Object} Returns the composed aggregate object. * @example * * _.groupBy([4.2, 6.1, 6.4], function(num) { return Math.floor(num); }); * // => { '4': [4.2], '6': [6.1, 6.4] } * * _.groupBy([4.2, 6.1, 6.4], function(num) { return this.floor(num); }, Math); * // => { '4': [4.2], '6': [6.1, 6.4] } * * // using "_.pluck" callback shorthand * _.groupBy(['one', 'two', 'three'], 'length'); * // => { '3': ['one', 'two'], '5': ['three'] } */ var groupBy = createAggregator(function(result, value, key) { (hasOwnProperty.call(result, key) ? result[key] : result[key] = []).push(value); }); /** * Creates an object composed of keys generated from the results of running * each element of the collection through the given callback. The corresponding * value of each key is the last element responsible for generating the key. * The callback is bound to `thisArg` and invoked with three arguments; * (value, index|key, collection). * * If a property name is provided for `callback` the created "_.pluck" style * callback will return the property value of the given element. * * If an object is provided for `callback` the created "_.where" style callback * will return `true` for elements that have the properties of the given object, * else `false`. * * @static * @memberOf _ * @category Collections * @param {Array|Object|string} collection The collection to iterate over. * @param {Function|Object|string} [callback=identity] The function called * per iteration. If a property name or object is provided it will be used * to create a "_.pluck" or "_.where" style callback, respectively. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {Object} Returns the composed aggregate object. * @example * * var keys = [ * { 'dir': 'left', 'code': 97 }, * { 'dir': 'right', 'code': 100 } * ]; * * _.indexBy(keys, 'dir'); * // => { 'left': { 'dir': 'left', 'code': 97 }, 'right': { 'dir': 'right', 'code': 100 } } * * _.indexBy(keys, function(key) { return String.fromCharCode(key.code); }); * // => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } } * * _.indexBy(characters, function(key) { this.fromCharCode(key.code); }, String); * // => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } } */ var indexBy = createAggregator(function(result, value, key) { result[key] = value; }); /** * Invokes the method named by `methodName` on each element in the `collection` * returning an array of the results of each invoked method. Additional arguments * will be provided to each invoked method. If `methodName` is a function it * will be invoked for, and `this` bound to, each element in the `collection`. * * @static * @memberOf _ * @category Collections * @param {Array|Object|string} collection The collection to iterate over. * @param {Function|string} methodName The name of the method to invoke or * the function invoked per iteration. * @param {...*} [arg] Arguments to invoke the method with. * @returns {Array} Returns a new array of the results of each invoked method. * @example * * _.invoke([[5, 1, 7], [3, 2, 1]], 'sort'); * // => [[1, 5, 7], [1, 2, 3]] * * _.invoke([123, 456], String.prototype.split, ''); * // => [['1', '2', '3'], ['4', '5', '6']] */ function invoke(collection, methodName) { var args = slice(arguments, 2), index = -1, isFunc = typeof methodName == 'function', length = collection ? collection.length : 0, result = Array(typeof length == 'number' ? length : 0); forEach(collection, function(value) { result[++index] = (isFunc ? methodName : value[methodName]).apply(value, args); }); return result; } /** * Creates an array of values by running each element in the collection * through the callback. The callback is bound to `thisArg` and invoked with * three arguments; (value, index|key, collection). * * If a property name is provided for `callback` the created "_.pluck" style * callback will return the property value of the given element. * * If an object is provided for `callback` the created "_.where" style callback * will return `true` for elements that have the properties of the given object, * else `false`. * * @static * @memberOf _ * @alias collect * @category Collections * @param {Array|Object|string} collection The collection to iterate over. * @param {Function|Object|string} [callback=identity] The function called * per iteration. If a property name or object is provided it will be used * to create a "_.pluck" or "_.where" style callback, respectively. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {Array} Returns a new array of the results of each `callback` execution. * @example * * _.map([1, 2, 3], function(num) { return num * 3; }); * // => [3, 6, 9] * * _.map({ 'one': 1, 'two': 2, 'three': 3 }, function(num) { return num * 3; }); * // => [3, 6, 9] (property order is not guaranteed across environments) * * var characters = [ * { 'name': 'barney', 'age': 36 }, * { 'name': 'fred', 'age': 40 } * ]; * * // using "_.pluck" callback shorthand * _.map(characters, 'name'); * // => ['barney', 'fred'] */ function map(collection, callback, thisArg) { var index = -1, length = collection ? collection.length : 0; callback = createCallback(callback, thisArg, 3); if (typeof length == 'number') { var result = Array(length); while (++index < length) { result[index] = callback(collection[index], index, collection); } } else { result = []; forOwn(collection, function(value, key, collection) { result[++index] = callback(value, key, collection); }); } return result; } /** * Retrieves the maximum value of a collection. If the collection is empty or * falsey `-Infinity` is returned. If a callback is provided it will be executed * for each value in the collection to generate the criterion by which the value * is ranked. The callback is bound to `thisArg` and invoked with three * arguments; (value, index, collection). * * If a property name is provided for `callback` the created "_.pluck" style * callback will return the property value of the given element. * * If an object is provided for `callback` the created "_.where" style callback * will return `true` for elements that have the properties of the given object, * else `false`. * * @static * @memberOf _ * @category Collections * @param {Array|Object|string} collection The collection to iterate over. * @param {Function|Object|string} [callback=identity] The function called * per iteration. If a property name or object is provided it will be used * to create a "_.pluck" or "_.where" style callback, respectively. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {*} Returns the maximum value. * @example * * _.max([4, 2, 8, 6]); * // => 8 * * var characters = [ * { 'name': 'barney', 'age': 36 }, * { 'name': 'fred', 'age': 40 } * ]; * * _.max(characters, function(chr) { return chr.age; }); * // => { 'name': 'fred', 'age': 40 }; * * // using "_.pluck" callback shorthand * _.max(characters, 'age'); * // => { 'name': 'fred', 'age': 40 }; */ function max(collection, callback, thisArg) { var computed = -Infinity, result = computed; // allows working with functions like `_.map` without using // their `index` argument as a callback if (typeof callback != 'function' && thisArg && thisArg[callback] === collection) { callback = null; } var index = -1, length = collection ? collection.length : 0; if (callback == null && typeof length == 'number') { while (++index < length) { var value = collection[index]; if (value > result) { result = value; } } } else { callback = createCallback(callback, thisArg, 3); forEach(collection, function(value, index, collection) { var current = callback(value, index, collection); if (current > computed) { computed = current; result = value; } }); } return result; } /** * Retrieves the minimum value of a collection. If the collection is empty or * falsey `Infinity` is returned. If a callback is provided it will be executed * for each value in the collection to generate the criterion by which the value * is ranked. The callback is bound to `thisArg` and invoked with three * arguments; (value, index, collection). * * If a property name is provided for `callback` the created "_.pluck" style * callback will return the property value of the given element. * * If an object is provided for `callback` the created "_.where" style callback * will return `true` for elements that have the properties of the given object, * else `false`. * * @static * @memberOf _ * @category Collections * @param {Array|Object|string} collection The collection to iterate over. * @param {Function|Object|string} [callback=identity] The function called * per iteration. If a property name or object is provided it will be used * to create a "_.pluck" or "_.where" style callback, respectively. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {*} Returns the minimum value. * @example * * _.min([4, 2, 8, 6]); * // => 2 * * var characters = [ * { 'name': 'barney', 'age': 36 }, * { 'name': 'fred', 'age': 40 } * ]; * * _.min(characters, function(chr) { return chr.age; }); * // => { 'name': 'barney', 'age': 36 }; * * // using "_.pluck" callback shorthand * _.min(characters, 'age'); * // => { 'name': 'barney', 'age': 36 }; */ function min(collection, callback, thisArg) { var computed = Infinity, result = computed; // allows working with functions like `_.map` without using // their `index` argument as a callback if (typeof callback != 'function' && thisArg && thisArg[callback] === collection) { callback = null; } var index = -1, length = collection ? collection.length : 0; if (callback == null && typeof length == 'number') { while (++index < length) { var value = collection[index]; if (value < result) { result = value; } } } else { callback = createCallback(callback, thisArg, 3); forEach(collection, function(value, index, collection) { var current = callback(value, index, collection); if (current < computed) { computed = current; result = value; } }); } return result; } /** * Retrieves the value of a specified property from all elements in the collection. * * @static * @memberOf _ * @type Function * @category Collections * @param {Array|Object|string} collection The collection to iterate over. * @param {string} property The property to pluck. * @returns {Array} Returns a new array of property values. * @example * * var characters = [ * { 'name': 'barney', 'age': 36 }, * { 'name': 'fred', 'age': 40 } * ]; * * _.pluck(characters, 'name'); * // => ['barney', 'fred'] */ 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 provided the first element of the collection will be * used as the initial `accumulator` value. The callback is bound to `thisArg` * and invoked with four arguments; (accumulator, value, index|key, collection). * * @static * @memberOf _ * @alias foldl, inject * @category Collections * @param {Array|Object|string} collection The collection to iterate over. * @param {Function} [callback=identity] The function called per iteration. * @param {*} [accumulator] Initial value of the accumulator. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {*} Returns the accumulated value. * @example * * var sum = _.reduce([1, 2, 3], function(sum, num) { * return sum + num; * }); * // => 6 * * var mapped = _.reduce({ 'a': 1, 'b': 2, 'c': 3 }, function(result, num, key) { * result[key] = num * 3; * return result; * }, {}); * // => { 'a': 3, 'b': 6, 'c': 9 } */ function reduce(collection, callback, accumulator, thisArg) { if (!collection) return accumulator; var noaccum = arguments.length < 3; callback = createCallback(callback, thisArg, 4); var index = -1, length = collection.length; if (typeof length == 'number') { if (noaccum) { accumulator = collection[++index]; } while (++index < length) { accumulator = callback(accumulator, collection[index], index, collection); } } else { forOwn(collection, function(value, index, collection) { accumulator = noaccum ? (noaccum = false, value) : callback(accumulator, value, index, collection) }); } return accumulator; } /** * This method is like `_.reduce` except that it iterates over elements * of a `collection` from right to left. * * @static * @memberOf _ * @alias foldr * @category Collections * @param {Array|Object|string} collection The collection to iterate over. * @param {Function} [callback=identity] The function called per iteration. * @param {*} [accumulator] Initial value of the accumulator. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {*} Returns the accumulated value. * @example * * var list = [[0, 1], [2, 3], [4, 5]]; * var flat = _.reduceRight(list, function(a, b) { return a.concat(b); }, []); * // => [4, 5, 2, 3, 0, 1] */ function reduceRight(collection, callback, accumulator, thisArg) { var noaccum = arguments.length < 3; callback = createCallback(callback, thisArg, 4); forEachRight(collection, function(value, index, collection) { accumulator = noaccum ? (noaccum = false, value) : callback(accumulator, value, index, collection); }); return accumulator; } /** * The opposite of `_.filter` this method returns the elements of a * collection that the callback does **not** return truey for. * * If a property name is provided for `callback` the created "_.pluck" style * callback will return the property value of the given element. * * If an object is provided for `callback` the created "_.where" style callback * will return `true` for elements that have the properties of the given object, * else `false`. * * @static * @memberOf _ * @category Collections * @param {Array|Object|string} collection The collection to iterate over. * @param {Function|Object|string} [callback=identity] The function called * per iteration. If a property name or object is provided it will be used * to create a "_.pluck" or "_.where" style callback, respectively. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {Array} Returns a new array of elements that failed the callback check. * @example * * var odds = _.reject([1, 2, 3, 4, 5, 6], function(num) { return num % 2 == 0; }); * // => [1, 3, 5] * * var characters = [ * { 'name': 'barney', 'age': 36, 'blocked': false }, * { 'name': 'fred', 'age': 40, 'blocked': true } * ]; * * // using "_.pluck" callback shorthand * _.reject(characters, 'blocked'); * // => [{ 'name': 'barney', 'age': 36, 'blocked': false }] * * // using "_.where" callback shorthand * _.reject(characters, { 'age': 36 }); * // => [{ 'name': 'fred', 'age': 40, 'blocked': true }] */ function reject(collection, callback, thisArg) { callback = createCallback(callback, thisArg, 3); return filter(collection, function(value, index, collection) { return !callback(value, index, collection); }); } /** * Retrieves a random element or `n` random elements from a collection. * * @static * @memberOf _ * @category Collections * @param {Array|Object|string} collection The collection to sample. * @param {number} [n] The number of elements to sample. * @param- {Object} [guard] Allows working with functions like `_.map` * without using their `index` arguments as `n`. * @returns {Array} Returns the random sample(s) of `collection`. * @example * * _.sample([1, 2, 3, 4]); * // => 2 * * _.sample([1, 2, 3, 4], 2); * // => [3, 1] */ function sample(collection, n, guard) { if (collection && typeof collection.length != 'number') { collection = values(collection); } if (n == null || guard) { return collection ? collection[baseRandom(0, collection.length - 1)] : undefined; } var result = shuffle(collection); result.length = nativeMin(nativeMax(0, n), result.length); return result; } /** * Creates an array of shuffled values, using a version of the Fisher-Yates * shuffle. See http://en.wikipedia.org/wiki/Fisher-Yates_shuffle. * * @static * @memberOf _ * @category Collections * @param {Array|Object|string} collection The collection to shuffle. * @returns {Array} Returns a new shuffled collection. * @example * * _.shuffle([1, 2, 3, 4, 5, 6]); * // => [4, 1, 6, 3, 5, 2] */ function shuffle(collection) { var index = -1, length = collection ? collection.length : 0, result = Array(typeof length == 'number' ? length : 0); forEach(collection, function(value) { var rand = baseRandom(0, ++index); result[index] = result[rand]; result[rand] = value; }); return result; } /** * Gets the size of the `collection` by returning `collection.length` for arrays * and array-like objects or the number of own enumerable properties for objects. * * @static * @memberOf _ * @category Collections * @param {Array|Object|string} collection The collection to inspect. * @returns {number} Returns `collection.length` or number of own enumerable properties. * @example * * _.size([1, 2]); * // => 2 * * _.size({ 'one': 1, 'two': 2, 'three': 3 }); * // => 3 * * _.size('pebbles'); * // => 5 */ function size(collection) { var length = collection ? collection.length : 0; return typeof length == 'number' ? length : keys(collection).length; } /** * Checks if the callback returns a truey value for **any** element of a * collection. The function returns as soon as it finds a passing value and * does not iterate over the entire collection. The callback is bound to * `thisArg` and invoked with three arguments; (value, index|key, collection). * * If a property name is provided for `callback` the created "_.pluck" style * callback will return the property value of the given element. * * If an object is provided for `callback` the created "_.where" style callback * will return `true` for elements that have the properties of the given object, * else `false`. * * @static * @memberOf _ * @alias any * @category Collections * @param {Array|Object|string} collection The collection to iterate over. * @param {Function|Object|string} [callback=identity] The function called * per iteration. If a property name or object is provided it will be used * to create a "_.pluck" or "_.where" style callback, respectively. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {boolean} Returns `true` if any element passed the callback check, * else `false`. * @example * * _.some([null, 0, 'yes', false], Boolean); * // => true * * var characters = [ * { 'name': 'barney', 'age': 36, 'blocked': false }, * { 'name': 'fred', 'age': 40, 'blocked': true } * ]; * * // using "_.pluck" callback shorthand * _.some(characters, 'blocked'); * // => true * * // using "_.where" callback shorthand * _.some(characters, { 'age': 1 }); * // => false */ function some(collection, callback, thisArg) { var result; callback = createCallback(callback, thisArg, 3); var index = -1, length = collection ? collection.length : 0; if (typeof length == 'number') { while (++index < length) { if ((result = callback(collection[index], index, collection))) { break; } } } else { forOwn(collection, function(value, index, collection) { return (result = callback(value, index, collection)) && indicatorObject; }); } return !!result; } /** * Creates an array of elements, sorted in ascending order by the results of * running each element in a collection through the callback. This method * performs a stable sort, that is, it will preserve the original sort order * of equal elements. The callback is bound to `thisArg` and invoked with * three arguments; (value, index|key, collection). * * If a property name is provided for `callback` the created "_.pluck" style * callback will return the property value of the given element. * * If an object is provided for `callback` the created "_.where" style callback * will return `true` for elements that have the properties of the given object, * else `false`. * * @static * @memberOf _ * @category Collections * @param {Array|Object|string} collection The collection to iterate over. * @param {Function|Object|string} [callback=identity] The function called * per iteration. If a property name or object is provided it will be used * to create a "_.pluck" or "_.where" style callback, respectively. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {Array} Returns a new array of 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, 3); forEach(collection, function(value, key, collection) { result[++index] = { 'criteria': callback(value, key, collection), 'index': index, 'value': value }; }); length = result.length; result.sort(compareAscending); while (length--) { result[length] = result[length].value; } return result; } /** * Converts the `collection` to an array. * * @static * @memberOf _ * @category Collections * @param {Array|Object|string} collection The collection to convert. * @returns {Array} Returns the new converted array. * @example * * (function() { return _.toArray(arguments).slice(1); })(1, 2, 3, 4); * // => [2, 3, 4] */ function toArray(collection) { if (isArray(collection)) { return slice(collection); } if (collection && typeof collection.length == 'number') { return map(collection); } return values(collection); } /** * Performs a deep comparison of each element in a `collection` to the given * `properties` object, returning an array of all elements that have equivalent * property values. * * @static * @memberOf _ * @type Function * @category Collections * @param {Array|Object|string} collection The collection to iterate over. * @param {Object} properties The object of property values to filter by. * @returns {Array} Returns a new array of elements that have the given properties. * @example * * var characters = [ * { 'name': 'barney', 'age': 36, 'pets': ['hoppy'] }, * { 'name': 'fred', 'age': 40, 'pets': ['baby puss', 'dino'] } * ]; * * _.where(characters, { 'age': 36 }); * // => [{ 'name': 'barney', 'age': 36, 'pets': ['hoppy'] }] * * _.where(characters, { 'pets': ['dino'] }); * // => [{ 'name': 'fred', 'age': 40, 'pets': ['baby puss', 'dino'] }] */ function where(collection, properties, first) { return (first && isEmpty(properties)) ? undefined : (first ? find : filter)(collection, properties); } /*--------------------------------------------------------------------------*/ /** * Creates an array with all falsey values removed. The values `false`, `null`, * `0`, `""`, `undefined`, and `NaN` are all falsey. * * @static * @memberOf _ * @category Arrays * @param {Array} array The array to compact. * @returns {Array} Returns a new array of filtered values. * @example * * _.compact([0, 1, false, 2, '', 3]); * // => [1, 2, 3] */ function compact(array) { var index = -1, length = array ? array.length : 0, result = []; while (++index < length) { var value = array[index]; if (value) { result.push(value); } } return result; } /** * Creates an array excluding all values of the provided arrays using strict * equality for comparisons, i.e. `===`. * * @static * @memberOf _ * @category Arrays * @param {Array} array The array to process. * @param {...Array} [values] The arrays of values to exclude. * @returns {Array} Returns a new array of filtered values. * @example * * _.difference([1, 2, 3, 4, 5], [5, 2, 10]); * // => [1, 3, 4] */ function difference(array) { return baseDifference(array, baseFlatten(arguments, true, true, 1)); } /** * Gets the first element or first `n` elements of an array. If a callback * is provided elements at the beginning of the array are returned as long * as the callback returns truey. The callback is bound to `thisArg` and * invoked with three arguments; (value, index, array). * * If a property name is provided for `callback` the created "_.pluck" style * callback will return the property value of the given element. * * If an object is provided for `callback` the created "_.where" style callback * will return `true` for elements that have the properties of the given object, * else `false`. * * @static * @memberOf _ * @alias head, take * @category Arrays * @param {Array} array The array to query. * @param {Function|Object|number|string} [callback] The function called * per element or the number of elements to return. If a property name or * object is provided it will be used to create a "_.pluck" or "_.where" * style callback, respectively. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {*} Returns the first element(s) of `array`. * @example * * _.first([1, 2, 3]); * // => 1 * * _.first([1, 2, 3], 2); * // => [1, 2] * * _.first([1, 2, 3], function(num) { * return num < 3; * }); * // => [1, 2] * * var characters = [ * { 'name': 'barney', 'blocked': true, 'employer': 'slate' }, * { 'name': 'fred', 'blocked': false, 'employer': 'slate' }, * { 'name': 'pebbles', 'blocked': true, 'employer': 'na' } * ]; * * // using "_.pluck" callback shorthand * _.first(characters, 'blocked'); * // => [{ 'name': 'barney', 'blocked': true, 'employer': 'slate' }] * * // using "_.where" callback shorthand * _.pluck(_.first(characters, { 'employer': 'slate' }), 'name'); * // => ['barney', 'fred'] */ function first(array, callback, thisArg) { var n = 0, length = array ? array.length : 0; if (typeof callback != 'number' && callback != null) { var index = -1; callback = createCallback(callback, thisArg, 3); while (++index < length && callback(array[index], index, array)) { n++; } } else { n = callback; if (n == null || thisArg) { return array ? array[0] : undefined; } } return slice(array, 0, nativeMin(nativeMax(0, n), length)); } /** * Flattens a nested array (the nesting can be to any depth). If `isShallow` * is truey, the array will only be flattened a single level. If a callback * is provided each element of the array is passed through the callback before * flattening. The callback is bound to `thisArg` and invoked with three * arguments; (value, index, array). * * If a property name is provided for `callback` the created "_.pluck" style * callback will return the property value of the given element. * * If an object is provided for `callback` the created "_.where" style callback * will return `true` for elements that have the properties of the given object, * else `false`. * * @static * @memberOf _ * @category Arrays * @param {Array} array The array to flatten. * @param {boolean} [isShallow=false] A flag to restrict flattening to a single level. * @param {Function|Object|string} [callback=identity] The function called * per iteration. If a property name or object is provided it will be used * to create a "_.pluck" or "_.where" style callback, respectively. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {Array} Returns a new flattened array. * @example * * _.flatten([1, [2], [3, [[4]]]]); * // => [1, 2, 3, 4]; * * _.flatten([1, [2], [3, [[4]]]], true); * // => [1, 2, 3, [[4]]]; * * var characters = [ * { 'name': 'barney', 'age': 30, 'pets': ['hoppy'] }, * { 'name': 'fred', 'age': 40, 'pets': ['baby puss', 'dino'] } * ]; * * // using "_.pluck" callback shorthand * _.flatten(characters, 'pets'); * // => ['hoppy', 'baby puss', 'dino'] */ function flatten(array, isShallow) { return baseFlatten(array, isShallow); } /** * Gets the index at which the first occurrence of `value` is found using * strict equality for comparisons, i.e. `===`. If the array is already sorted * providing `true` for `fromIndex` will run a faster binary search. * * @static * @memberOf _ * @category Arrays * @param {Array} array The array to search. * @param {*} value The value to search for. * @param {boolean|number} [fromIndex=0] The index to search from or `true` * to perform a binary search on a sorted array. * @returns {number} Returns the index of the matched value or `-1`. * @example * * _.indexOf([1, 2, 3, 1, 2, 3], 2); * // => 1 * * _.indexOf([1, 2, 3, 1, 2, 3], 2, 3); * // => 4 * * _.indexOf([1, 1, 2, 2, 3, 3], 2, true); * // => 2 */ function indexOf(array, value, fromIndex) { if (typeof fromIndex == 'number') { var length = array ? array.length : 0; fromIndex = (fromIndex < 0 ? nativeMax(0, length + fromIndex) : fromIndex || 0); } else if (fromIndex) { var index = sortedIndex(array, value); return array[index] === value ? index : -1; } return baseIndexOf(array, value, fromIndex); } /** * Gets all but the last element or last `n` elements of an array. If a * callback is provided elements at the end of the array are excluded from * the result as long as the callback returns truey. The callback is bound * to `thisArg` and invoked with three arguments; (value, index, array). * * If a property name is provided for `callback` the created "_.pluck" style * callback will return the property value of the given element. * * If an object is provided for `callback` the created "_.where" style callback * will return `true` for elements that have the properties of the given object, * else `false`. * * @static * @memberOf _ * @category Arrays * @param {Array} array The array to query. * @param {Function|Object|number|string} [callback=1] The function called * per element or the number of elements to exclude. If a property name or * object is provided it will be used to create a "_.pluck" or "_.where" * style callback, respectively. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {Array} Returns a slice of `array`. * @example * * _.initial([1, 2, 3]); * // => [1, 2] * * _.initial([1, 2, 3], 2); * // => [1] * * _.initial([1, 2, 3], function(num) { * return num > 1; * }); * // => [1] * * var characters = [ * { 'name': 'barney', 'blocked': false, 'employer': 'slate' }, * { 'name': 'fred', 'blocked': true, 'employer': 'slate' }, * { 'name': 'pebbles', 'blocked': true, 'employer': 'na' } * ]; * * // using "_.pluck" callback shorthand * _.initial(characters, 'blocked'); * // => [{ 'name': 'barney', 'blocked': false, 'employer': 'slate' }] * * // using "_.where" callback shorthand * _.pluck(_.initial(characters, { 'employer': 'na' }), 'name'); * // => ['barney', 'fred'] */ function initial(array, callback, thisArg) { var n = 0, length = array ? array.length : 0; if (typeof callback != 'number' && callback != null) { var index = length; callback = createCallback(callback, thisArg, 3); while (index-- && callback(array[index], index, array)) { n++; } } else { n = (callback == null || thisArg) ? 1 : callback || n; } return slice(array, 0, nativeMin(nativeMax(0, length - n), length)); } /** * Creates an array of unique values present in all provided arrays using * strict equality for comparisons, i.e. `===`. * * @static * @memberOf _ * @category Arrays * @param {...Array} [array] The arrays to inspect. * @returns {Array} Returns an array of composite values. * @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 or last `n` elements of an array. If a callback is * provided elements at the end of the array are returned as long as the * callback returns truey. The callback is bound to `thisArg` and invoked * with three arguments; (value, index, array). * * If a property name is provided for `callback` the created "_.pluck" style * callback will return the property value of the given element. * * If an object is provided for `callback` the created "_.where" style callback * will return `true` for elements that have the properties of the given object, * else `false`. * * @static * @memberOf _ * @category Arrays * @param {Array} array The array to query. * @param {Function|Object|number|string} [callback] The function called * per element or the number of elements to return. If a property name or * object is provided it will be used to create a "_.pluck" or "_.where" * style callback, respectively. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {*} Returns the last element(s) of `array`. * @example * * _.last([1, 2, 3]); * // => 3 * * _.last([1, 2, 3], 2); * // => [2, 3] * * _.last([1, 2, 3], function(num) { * return num > 1; * }); * // => [2, 3] * * var characters = [ * { 'name': 'barney', 'blocked': false, 'employer': 'slate' }, * { 'name': 'fred', 'blocked': true, 'employer': 'slate' }, * { 'name': 'pebbles', 'blocked': true, 'employer': 'na' } * ]; * * // using "_.pluck" callback shorthand * _.pluck(_.last(characters, 'blocked'), 'name'); * // => ['fred', 'pebbles'] * * // using "_.where" callback shorthand * _.last(characters, { 'employer': 'na' }); * // => [{ 'name': 'pebbles', 'blocked': true, 'employer': 'na' }] */ function last(array, callback, thisArg) { var n = 0, length = array ? array.length : 0; if (typeof callback != 'number' && callback != null) { var index = length; callback = createCallback(callback, thisArg, 3); while (index-- && callback(array[index], index, array)) { n++; } } else { n = callback; if (n == null || thisArg) { return array ? array[length - 1] : undefined; } } return slice(array, nativeMax(0, length - n)); } /** * Gets the index at which the last occurrence of `value` is found using strict * equality for comparisons, i.e. `===`. If `fromIndex` is negative, it is used * as the offset from the end of the collection. * * If a property name is provided for `callback` the created "_.pluck" style * callback will return the property value of the given element. * * If an object is provided for `callback` the created "_.where" style callback * will return `true` for elements that have the properties of the given object, * else `false`. * * @static * @memberOf _ * @category Arrays * @param {Array} array The array to search. * @param {*} value The value to search for. * @param {number} [fromIndex=array.length-1] The index to search from. * @returns {number} Returns the index of the matched value or `-1`. * @example * * _.lastIndexOf([1, 2, 3, 1, 2, 3], 2); * // => 4 * * _.lastIndexOf([1, 2, 3, 1, 2, 3], 2, 3); * // => 1 */ function lastIndexOf(array, value, fromIndex) { var index = array ? array.length : 0; if (typeof fromIndex == 'number') { index = (fromIndex < 0 ? nativeMax(0, index + fromIndex) : nativeMin(fromIndex, index - 1)) + 1; } while (index--) { if (array[index] === value) { return index; } } return -1; } /** * Creates an array of numbers (positive and/or negative) progressing from * `start` up to but not including `end`. If `start` is less than `stop` a * zero-length range is created unless a negative `step` is specified. * * @static * @memberOf _ * @category Arrays * @param {number} [start=0] The start of the range. * @param {number} end The end of the range. * @param {number} [step=1] The value to increment or decrement by. * @returns {Array} Returns a new range array. * @example * * _.range(4); * // => [0, 1, 2, 3] * * _.range(1, 5); * // => [1, 2, 3, 4] * * _.range(0, 20, 5); * // => [0, 5, 10, 15] * * _.range(0, -4, -1); * // => [0, -1, -2, -3] * * _.range(1, 4, 0); * // => [1, 1, 1] * * _.range(0); * // => [] */ function range(start, end, step) { start = +start || 0; step = (+step || 1); if (end == null) { end = start; start = 0; } // use `Array(length)` so engines like Chakra and V8 avoid slower modes // http://youtu.be/XAqIpGU8ZZk#t=17m25s var index = -1, length = nativeMax(0, ceil((end - start) / step)), result = Array(length); while (++index < length) { result[index] = start; start += step; } return result; } /** * The opposite of `_.initial` this method gets all but the first element or * first `n` elements of an array. If a callback function is provided elements * at the beginning of the array are excluded from the result as long as the * callback returns truey. The callback is bound to `thisArg` and invoked * with three arguments; (value, index, array). * * If a property name is provided for `callback` the created "_.pluck" style * callback will return the property value of the given element. * * If an object is provided for `callback` the created "_.where" style callback * will return `true` for elements that have the properties of the given object, * else `false`. * * @static * @memberOf _ * @alias drop, tail * @category Arrays * @param {Array} array The array to query. * @param {Function|Object|number|string} [callback=1] The function called * per element or the number of elements to exclude. If a property name or * object is provided it will be used to create a "_.pluck" or "_.where" * style callback, respectively. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {Array} Returns a slice of `array`. * @example * * _.rest([1, 2, 3]); * // => [2, 3] * * _.rest([1, 2, 3], 2); * // => [3] * * _.rest([1, 2, 3], function(num) { * return num < 3; * }); * // => [3] * * var characters = [ * { 'name': 'barney', 'blocked': true, 'employer': 'slate' }, * { 'name': 'fred', 'blocked': false, 'employer': 'slate' }, * { 'name': 'pebbles', 'blocked': true, 'employer': 'na' } * ]; * * // using "_.pluck" callback shorthand * _.pluck(_.rest(characters, 'blocked'), 'name'); * // => ['fred', 'pebbles'] * * // using "_.where" callback shorthand * _.rest(characters, { 'employer': 'slate' }); * // => [{ 'name': 'pebbles', 'blocked': true, 'employer': 'na' }] */ function rest(array, callback, thisArg) { if (typeof callback != 'number' && callback != null) { var n = 0, index = -1, length = array ? array.length : 0; callback = createCallback(callback, thisArg, 3); while (++index < length && callback(array[index], index, array)) { n++; } } else { n = (callback == null || thisArg) ? 1 : nativeMax(0, callback); } return slice(array, n); } /** * Uses a binary search to determine the smallest index at which a value * should be inserted into a given sorted array in order to maintain the sort * order of the array. If a callback is provided it will be executed for * `value` and each element of `array` to compute their sort ranking. The * callback is bound to `thisArg` and invoked with one argument; (value). * * If a property name is provided for `callback` the created "_.pluck" style * callback will return the property value of the given element. * * If an object is provided for `callback` the created "_.where" style callback * will return `true` for elements that have the properties of the given object, * else `false`. * * @static * @memberOf _ * @category Arrays * @param {Array} array The array to inspect. * @param {*} value The value to evaluate. * @param {Function|Object|string} [callback=identity] The function called * per iteration. If a property name or object is provided it will be used * to create a "_.pluck" or "_.where" style callback, respectively. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {number} Returns the index at which `value` should be inserted * into `array`. * @example * * _.sortedIndex([20, 30, 50], 40); * // => 2 * * // using "_.pluck" callback shorthand * _.sortedIndex([{ 'x': 20 }, { 'x': 30 }, { 'x': 50 }], { 'x': 40 }, 'x'); * // => 2 * * var dict = { * 'wordToNumber': { 'twenty': 20, 'thirty': 30, 'fourty': 40, 'fifty': 50 } * }; * * _.sortedIndex(['twenty', 'thirty', 'fifty'], 'fourty', function(word) { * return dict.wordToNumber[word]; * }); * // => 2 * * _.sortedIndex(['twenty', 'thirty', 'fifty'], 'fourty', function(word) { * return this.wordToNumber[word]; * }, dict); * // => 2 */ function sortedIndex(array, value, callback, thisArg) { var low = 0, high = array ? array.length : low; // explicitly reference `identity` for better inlining in Firefox callback = callback ? createCallback(callback, thisArg, 1) : identity; value = callback(value); while (low < high) { var mid = (low + high) >>> 1; (callback(array[mid]) < value) ? low = mid + 1 : high = mid; } return low; } /** * Creates an array of unique values, in order, of the provided arrays using * strict equality for comparisons, i.e. `===`. * * @static * @memberOf _ * @category Arrays * @param {...Array} [array] The arrays to inspect. * @returns {Array} Returns an array of composite values. * @example * * _.union([1, 2, 3], [101, 2, 1, 10], [2, 1]); * // => [1, 2, 3, 101, 10] */ function union(array) { return baseUniq(baseFlatten(arguments, true, true)); } /** * Creates a duplicate-value-free version of an array using strict equality * for comparisons, i.e. `===`. If the array is sorted, providing * `true` for `isSorted` will use a faster algorithm. If a callback is provided * each element of `array` is passed through the callback before uniqueness * is computed. The callback is bound to `thisArg` and invoked with three * arguments; (value, index, array). * * If a property name is provided for `callback` the created "_.pluck" style * callback will return the property value of the given element. * * If an object is provided for `callback` the created "_.where" style callback * will return `true` for elements that have the properties of the given object, * else `false`. * * @static * @memberOf _ * @alias unique * @category Arrays * @param {Array} array The array to process. * @param {boolean} [isSorted=false] A flag to indicate that `array` is sorted. * @param {Function|Object|string} [callback=identity] The function called * per iteration. If a property name or object is provided it will be used * to create a "_.pluck" or "_.where" style callback, respectively. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {Array} Returns a duplicate-value-free array. * @example * * _.uniq([1, 2, 1, 3, 1]); * // => [1, 2, 3] * * _.uniq([1, 1, 2, 2, 3], true); * // => [1, 2, 3] * * _.uniq(['A', 'b', 'C', 'a', 'B', 'c'], function(letter) { return letter.toLowerCase(); }); * // => ['A', 'b', 'C'] * * _.uniq([1, 2.5, 3, 1.5, 2, 3.5], function(num) { return this.floor(num); }, Math); * // => [1, 2.5, 3] * * // using "_.pluck" callback shorthand * _.uniq([{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }], 'x'); * // => [{ 'x': 1 }, { 'x': 2 }] */ function uniq(array, isSorted, callback, thisArg) { // juggle arguments if (typeof isSorted != 'boolean' && isSorted != null) { thisArg = callback; callback = (typeof isSorted != 'function' && thisArg && thisArg[isSorted] === array) ? null : isSorted; isSorted = false; } if (callback != null) { callback = createCallback(callback, thisArg, 3); } return baseUniq(array, isSorted, callback); } /** * Creates an array excluding all provided values using strict equality for * comparisons, i.e. `===`. * * @static * @memberOf _ * @category Arrays * @param {Array} array The array to filter. * @param {...*} [value] The values to exclude. * @returns {Array} Returns a new array of filtered values. * @example * * _.without([1, 2, 1, 0, 3, 1, 4], 0, 1); * // => [2, 3, 4] */ function without(array) { return baseDifference(array, slice(arguments, 1)); } /** * Creates an array of grouped elements, the first of which contains the first * elements of the given arrays, the second of which contains the second * elements of the given arrays, and so on. * * @static * @memberOf _ * @alias unzip * @category Arrays * @param {...Array} [array] Arrays to process. * @returns {Array} Returns a new array of grouped elements. * @example * * _.zip(['fred', 'barney'], [30, 40], [true, false]); * // => [['fred', 30, true], ['barney', 40, false]] */ function zip() { var index = -1, length = max(pluck(arguments, 'length')), result = Array(length < 0 ? 0 : length); while (++index < length) { result[index] = pluck(arguments, index); } return result; } /** * Creates an object composed from arrays of `keys` and `values`. Provide * either a single two dimensional array, i.e. `[[key1, value1], [key2, value2]]` * or two arrays, one of `keys` and one of corresponding `values`. * * @static * @memberOf _ * @alias object * @category Arrays * @param {Array} keys The array of keys. * @param {Array} [values=[]] The array of values. * @returns {Object} Returns an object composed of the given keys and * corresponding values. * @example * * _.zipObject(['fred', 'barney'], [30, 40]); * // => { 'fred': 30, 'barney': 40 } */ function zipObject(keys, values) { var index = -1, length = keys ? keys.length : 0, result = {}; while (++index < length) { var key = keys[index]; if (values) { result[key] = values[index]; } else if (key) { result[key[0]] = key[1]; } } return result; } /*--------------------------------------------------------------------------*/ /** * Creates a function that executes `func`, with the `this` binding and * arguments of the created function, only after being called `n` times. * * @static * @memberOf _ * @category Functions * @param {number} n The number of times the function must be called before * `func` is executed. * @param {Function} func The function to restrict. * @returns {Function} Returns the new restricted function. * @example * * var saves = ['profile', 'settings']; * * var done = _.after(saves.length, function() { * console.log('Done saving!'); * }); * * _.forEach(saves, function(type) { * asyncSave({ 'type': type, 'complete': done }); * }); * // => logs 'Done saving!', after all saves have completed */ function after(n, func) { if (!isFunction(func)) { throw new TypeError; } return function() { if (--n < 1) { return func.apply(this, arguments); } }; } /** * Creates a function that, when called, invokes `func` with the `this` * binding of `thisArg` and prepends any additional `bind` arguments to those * provided to the bound function. * * @static * @memberOf _ * @category Functions * @param {Function} func The function to bind. * @param {*} [thisArg] The `this` binding of `func`. * @param {...*} [arg] Arguments to be partially applied. * @returns {Function} Returns the new bound function. * @example * * var func = function(greeting) { * return greeting + ' ' + this.name; * }; * * func = _.bind(func, { 'name': 'fred' }, 'hi'); * func(); * // => 'hi fred' */ function bind(func, thisArg) { return arguments.length > 2 ? createWrapper(func, 17, slice(arguments, 2), null, thisArg) : createWrapper(func, 1, null, null, thisArg); } /** * Binds methods of an object to the object itself, overwriting the existing * method. Method names may be specified as individual arguments or as arrays * of method names. If no method names are provided all the function properties * of `object` will be bound. * * @static * @memberOf _ * @category Functions * @param {Object} object The object to bind and assign the bound methods to. * @param {...string} [methodName] The object method names to * bind, specified as individual method names or arrays of method names. * @returns {Object} Returns `object`. * @example * * var view = { * 'label': 'docs', * 'onClick': function() { console.log('clicked ' + this.label); } * }; * * _.bindAll(view); * jQuery('#docs').on('click', view.onClick); * // => logs 'clicked docs', when the button is clicked */ function bindAll(object) { var funcs = arguments.length > 1 ? baseFlatten(arguments, true, false, 1) : functions(object), index = -1, length = funcs.length; while (++index < length) { var key = funcs[index]; object[key] = createWrapper(object[key], 1, null, null, object); } return object; } /** * Creates a function that is the composition of the provided functions, * where each function consumes the return value of the function that follows. * For example, composing the functions `f()`, `g()`, and `h()` produces `f(g(h()))`. * Each function is executed with the `this` binding of the composed function. * * @static * @memberOf _ * @category Functions * @param {...Function} [func] Functions to compose. * @returns {Function} Returns the new composed function. * @example * * var realNameMap = { * 'pebbles': 'penelope' * }; * * var format = function(name) { * name = realNameMap[name.toLowerCase()] || name; * return name.charAt(0).toUpperCase() + name.slice(1).toLowerCase(); * }; * * var greet = function(formatted) { * return 'Hiya ' + formatted + '!'; * }; * * var welcome = _.compose(greet, format); * welcome('pebbles'); * // => 'Hiya Penelope!' */ function compose() { var funcs = arguments, length = funcs.length; while (length--) { if (!isFunction(funcs[length])) { throw new TypeError; } } return function() { var args = arguments, length = funcs.length; while (length--) { args = [funcs[length].apply(this, args)]; } return args[0]; }; } /** * Produces a callback bound to an optional `thisArg`. If `func` is a property * name the created callback will return the property value for a given element. * If `func` is an object the created callback will return `true` for elements * that contain the equivalent object properties, otherwise it will return `false`. * * @static * @memberOf _ * @category Functions * @param {*} [func=identity] The value to convert to a callback. * @param {*} [thisArg] The `this` binding of the created callback. * @param {number} [argCount] The number of arguments the callback accepts. * @returns {Function} Returns a callback function. * @example * * var characters = [ * { 'name': 'barney', 'age': 36 }, * { 'name': 'fred', 'age': 40 } * ]; * * // wrap to create custom callback shorthands * _.createCallback = _.wrap(_.createCallback, function(func, callback, thisArg) { * var match = /^(.+?)__([gl]t)(.+)$/.exec(callback); * return !match ? func(callback, thisArg) : function(object) { * return match[2] == 'gt' ? object[match[1]] > match[3] : object[match[1]] < match[3]; * }; * }); * * _.filter(characters, 'age__gt38'); * // => [{ 'name': 'fred', 'age': 40 }] */ function createCallback(func, thisArg, argCount) { var type = typeof func; if (func == null || type == 'function') { return baseCreateCallback(func, thisArg, argCount); } // handle "_.pluck" style callback shorthands if (type != 'object') { return 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; }; } /** * Creates a function that will delay the execution of `func` until after * `wait` milliseconds have elapsed since the last time it was invoked. * Provide an options object to indicate that `func` should be invoked on * the leading and/or trailing edge of the `wait` timeout. Subsequent calls * to the debounced function will return the result of the last `func` call. * * Note: If `leading` and `trailing` options are `true` `func` will be called * on the trailing edge of the timeout only if the the debounced function is * invoked more than once during the `wait` timeout. * * @static * @memberOf _ * @category Functions * @param {Function} func The function to debounce. * @param {number} wait The number of milliseconds to delay. * @param {Object} [options] The options object. * @param {boolean} [options.leading=false] Specify execution on the leading edge of the timeout. * @param {number} [options.maxWait] The maximum time `func` is allowed to be delayed before it's called. * @param {boolean} [options.trailing=true] Specify execution on the trailing edge of the timeout. * @returns {Function} Returns the new debounced function. * @example * * // avoid costly calculations while the window size is in flux * var lazyLayout = _.debounce(calculateLayout, 150); * jQuery(window).on('resize', lazyLayout); * * // execute `sendMail` when the click event is fired, debouncing subsequent calls * jQuery('#postbox').on('click', _.debounce(sendMail, 300, { * 'leading': true, * 'trailing': false * }); * * // ensure `batchLog` is executed once after 1 second of debounced calls * var source = new EventSource('/stream'); * source.addEventListener('message', _.debounce(batchLog, 250, { * 'maxWait': 1000 * }, false); */ function debounce(func, wait, options) { var args, maxTimeoutId, result, stamp, thisArg, timeoutId, trailingCall, lastCalled = 0, maxWait = false, trailing = true; if (!isFunction(func)) { throw new TypeError; } wait = nativeMax(0, wait) || 0; if (options === true) { var leading = true; trailing = false; } else if (isObject(options)) { leading = options.leading; maxWait = 'maxWait' in options && (nativeMax(wait, options.maxWait) || 0); trailing = 'trailing' in options ? options.trailing : trailing; } var delayed = function() { var remaining = wait - (now() - stamp); if (remaining <= 0) { if (maxTimeoutId) { clearTimeout(maxTimeoutId); } var isCalled = trailingCall; maxTimeoutId = timeoutId = trailingCall = undefined; if (isCalled) { lastCalled = now(); result = func.apply(thisArg, args); if (!timeoutId && !maxTimeoutId) { args = thisArg = null; } } } else { timeoutId = setTimeout(delayed, remaining); } }; var maxDelayed = function() { if (timeoutId) { clearTimeout(timeoutId); } maxTimeoutId = timeoutId = trailingCall = undefined; if (trailing || (maxWait !== wait)) { lastCalled = now(); result = func.apply(thisArg, args); if (!timeoutId && !maxTimeoutId) { args = thisArg = null; } } }; return function() { args = arguments; stamp = now(); thisArg = this; trailingCall = trailing && (timeoutId || !leading); if (maxWait === false) { var leadingCall = leading && !timeoutId; } else { if (!maxTimeoutId && !leading) { lastCalled = stamp; } var remaining = maxWait - (stamp - lastCalled), isCalled = remaining <= 0; if (isCalled) { if (maxTimeoutId) { maxTimeoutId = clearTimeout(maxTimeoutId); } lastCalled = stamp; result = func.apply(thisArg, args); } else if (!maxTimeoutId) { maxTimeoutId = setTimeout(maxDelayed, remaining); } } if (isCalled && timeoutId) { timeoutId = clearTimeout(timeoutId); } else if (!timeoutId && wait !== maxWait) { timeoutId = setTimeout(delayed, wait); } if (leadingCall) { isCalled = true; result = func.apply(thisArg, args); } if (isCalled && !timeoutId && !maxTimeoutId) { args = thisArg = null; } return result; }; } /** * Defers executing the `func` function until the current call stack has cleared. * Additional arguments will be provided to `func` when it is invoked. * * @static * @memberOf _ * @category Functions * @param {Function} func The function to defer. * @param {...*} [arg] Arguments to invoke the function with. * @returns {number} Returns the timer id. * @example * * _.defer(function() { console.log('deferred'); }); * // returns from the function before 'deferred' is logged */ function defer(func) { if (!isFunction(func)) { throw new TypeError; } var args = slice(arguments, 1); return setTimeout(function() { func.apply(undefined, args); }, 1); } /** * Executes the `func` function after `wait` milliseconds. Additional arguments * will be provided to `func` when it is invoked. * * @static * @memberOf _ * @category Functions * @param {Function} func The function to delay. * @param {number} wait The number of milliseconds to delay execution. * @param {...*} [arg] Arguments to invoke the function with. * @returns {number} Returns the timer id. * @example * * var log = _.bind(console.log, console); * _.delay(log, 1000, 'logged later'); * // => 'logged later' (Appears after one second.) */ function delay(func, wait) { if (!isFunction(func)) { throw new TypeError; } var args = slice(arguments, 2); return setTimeout(function() { func.apply(undefined, args); }, wait); } /** * Creates a function that memoizes the result of `func`. If `resolver` is * provided it will be used to determine the cache key for storing the result * based on the arguments provided to the memoized function. By default, the * first argument provided to the memoized function is used as the cache key. * The `func` is executed with the `this` binding of the memoized function. * The result cache is exposed as the `cache` property on the memoized function. * * @static * @memberOf _ * @category Functions * @param {Function} func The function to have its output memoized. * @param {Function} [resolver] A function used to resolve the cache key. * @returns {Function} Returns the new memoizing function. * @example * * var fibonacci = _.memoize(function(n) { * return n < 2 ? n : fibonacci(n - 1) + fibonacci(n - 2); * }); * * fibonacci(9) * // => 34 * * var data = { * 'fred': { 'name': 'fred', 'age': 40 }, * 'pebbles': { 'name': 'pebbles', 'age': 1 } * }; * * // modifying the result cache * var get = _.memoize(function(name) { return data[name]; }, _.identity); * get('pebbles'); * // => { 'name': 'pebbles', 'age': 1 } * * get.cache.pebbles.name = 'penelope'; * get('pebbles'); * // => { 'name': 'penelope', 'age': 1 } */ function memoize(func, resolver) { var cache = {}; return function() { var key = resolver ? resolver.apply(this, arguments) : keyPrefix + arguments[0]; return hasOwnProperty.call(cache, key) ? cache[key] : (cache[key] = func.apply(this, arguments)); }; } /** * Creates a function that is restricted to execute `func` once. Repeat calls to * the function will return the value of the first call. The `func` is executed * with the `this` binding of the created function. * * @static * @memberOf _ * @category Functions * @param {Function} func The function to restrict. * @returns {Function} Returns the new restricted function. * @example * * var initialize = _.once(createApplication); * initialize(); * initialize(); * // `initialize` executes `createApplication` once */ function once(func) { var ran, result; if (!isFunction(func)) { throw new TypeError; } return function() { if (ran) { return result; } ran = true; result = func.apply(this, arguments); // clear the `func` variable so the function may be garbage collected func = null; return result; }; } /** * Creates a function that, when called, invokes `func` with any additional * `partial` arguments prepended to those provided to the new function. This * method is similar to `_.bind` except it does **not** alter the `this` binding. * * @static * @memberOf _ * @category Functions * @param {Function} func The function to partially apply arguments to. * @param {...*} [arg] Arguments to be partially applied. * @returns {Function} Returns the new partially applied function. * @example * * var greet = function(greeting, name) { return greeting + ' ' + name; }; * var hi = _.partial(greet, 'hi'); * hi('fred'); * // => 'hi fred' */ function partial(func) { return createWrapper(func, 16, slice(arguments, 1)); } /** * Creates a function that, when executed, will only call the `func` function * at most once per every `wait` milliseconds. Provide an options object to * indicate that `func` should be invoked on the leading and/or trailing edge * of the `wait` timeout. Subsequent calls to the throttled function will * return the result of the last `func` call. * * Note: If `leading` and `trailing` options are `true` `func` will be called * on the trailing edge of the timeout only if the the throttled function is * invoked more than once during the `wait` timeout. * * @static * @memberOf _ * @category Functions * @param {Function} func The function to throttle. * @param {number} wait The number of milliseconds to throttle executions to. * @param {Object} [options] The options object. * @param {boolean} [options.leading=true] Specify execution on the leading edge of the timeout. * @param {boolean} [options.trailing=true] Specify execution on the trailing edge of the timeout. * @returns {Function} Returns the new throttled function. * @example * * // avoid excessively updating the position while scrolling * var throttled = _.throttle(updatePosition, 100); * jQuery(window).on('scroll', throttled); * * // execute `renewToken` when the click event is fired, but not more than once every 5 minutes * jQuery('.interactive').on('click', _.throttle(renewToken, 300000, { * 'trailing': false * })); */ function throttle(func, wait, options) { var leading = true, trailing = true; if (!isFunction(func)) { throw new TypeError; } if (options === false) { leading = false; } else if (isObject(options)) { leading = 'leading' in options ? options.leading : leading; trailing = 'trailing' in options ? options.trailing : trailing; } options = {}; options.leading = leading; options.maxWait = wait; options.trailing = trailing; return debounce(func, wait, options); } /** * Creates a function that provides `value` to the wrapper function as its * first argument. Additional arguments provided to the function are appended * to those provided to the wrapper function. The wrapper is executed with * the `this` binding of the created function. * * @static * @memberOf _ * @category Functions * @param {*} value The value to wrap. * @param {Function} wrapper The wrapper function. * @returns {Function} Returns the new function. * @example * * var p = _.wrap(_.escape, function(func, text) { * return '

' + func(text) + '

'; * }); * * p('Fred, Wilma, & Pebbles'); * // => '

Fred, Wilma, & Pebbles

' */ function wrap(value, wrapper) { return createWrapper(wrapper, 16, [value]); } /*--------------------------------------------------------------------------*/ /** * Converts the characters `&`, `<`, `>`, `"`, and `'` in `string` to their * corresponding HTML entities. * * @static * @memberOf _ * @category Utilities * @param {string} string The string to escape. * @returns {string} Returns the escaped string. * @example * * _.escape('Fred, Wilma, & Pebbles'); * // => 'Fred, Wilma, & Pebbles' */ function escape(string) { return string == null ? '' : String(string).replace(reUnescapedHtml, escapeHtmlChar); } /** * This method returns the first argument provided to it. * * @static * @memberOf _ * @category Utilities * @param {*} value Any value. * @returns {*} Returns `value`. * @example * * var object = { 'name': 'fred' }; * _.identity(object) === object; * // => true */ function identity(value) { return value; } /** * Adds function properties of a source object to the `lodash` function and * chainable wrapper. * * @static * @memberOf _ * @category Utilities * @param {Object} object The object of function properties to add to `lodash`. * @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('fred'); * // => 'Fred' * * _('fred').capitalize(); * // => 'Fred' */ function mixin(object) { forEach(functions(object), function(methodName) { var func = lodash[methodName] = object[methodName]; lodash.prototype[methodName] = function() { var args = [this.__wrapped__]; push.apply(args, arguments); var result = func.apply(lodash, args); return this.__chain__ ? new lodashWrapper(result, true) : result; }; }); } /** * Reverts the '_' variable to its previous value and returns a reference to * the `lodash` function. * * @static * @memberOf _ * @category Utilities * @returns {Function} Returns the `lodash` function. * @example * * var lodash = _.noConflict(); */ function noConflict() { root._ = oldDash; return this; } /** * A no-operation function. * * @static * @memberOf _ * @category Utilities * @example * * var object = { 'name': 'fred' }; * _.noop(object) === undefined; * // => true */ function noop() { // no operation performed } /** * Produces a random number between `min` and `max` (inclusive). If only one * argument is provided a number between `0` and the given number will be * returned. If `floating` is truey or either `min` or `max` are floats a * floating-point number will be returned instead of an integer. * * @static * @memberOf _ * @category Utilities * @param {number} [min=0] The minimum possible value. * @param {number} [max=1] The maximum possible value. * @param {boolean} [floating=false] Specify returning a floating-point number. * @returns {number} Returns a random number. * @example * * _.random(0, 5); * // => an integer between 0 and 5 * * _.random(5); * // => also an integer between 0 and 5 * * _.random(5, true); * // => a floating-point number between 0 and 5 * * _.random(1.2, 5.2); * // => a floating-point number between 1.2 and 5.2 */ function random(min, max) { if (min == null && max == null) { max = 1; } min = +min || 0; if (max == null) { max = min; min = 0; } else { max = +max || 0; } return min + floor(nativeRandom() * (max - min + 1)); } /** * Resolves the value of `property` 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 {*} 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) { if (object) { var value = object[property]; 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. * @param {RegExp} [options.escape] The "escape" delimiter. * @param {RegExp} [options.evaluate] The "evaluate" delimiter. * @param {Object} [options.imports] An object to import into the template as local variables. * @param {RegExp} [options.interpolate] The "interpolate" delimiter. * @param {string} [sourceURL] The sourceURL of the template's compiled source. * @param {string} [variable] The data object variable name. * @returns {Function|string} Returns a compiled function when no `data` object * is given, else it returns the interpolated text. * @example * * // using the "interpolate" delimiter to create a compiled template * var compiled = _.template('hello <%= name %>'); * compiled({ 'name': 'fred' }); * // => 'hello fred' * * // using the "escape" delimiter to escape HTML in data property values * _.template('<%- value %>', { 'value': '