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Diffstat (limited to 'web/src/vendor/lodash/lodash.js')
| -rw-r--r-- | web/src/vendor/lodash/lodash.js | 6785 |
1 files changed, 6785 insertions, 0 deletions
diff --git a/web/src/vendor/lodash/lodash.js b/web/src/vendor/lodash/lodash.js new file mode 100644 index 00000000..d653e5ae --- /dev/null +++ b/web/src/vendor/lodash/lodash.js @@ -0,0 +1,6785 @@ +/** + * @license + * Lo-Dash 2.4.1 (Custom Build) <http://lodash.com/> + * Build: `lodash modern -o ./dist/lodash.js` + * Copyright 2012-2013 The Dojo Foundation <http://dojofoundation.org/> + * Based on Underscore.js 1.5.2 <http://underscorejs.org/LICENSE> + * Copyright 2009-2013 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors + * Available under MIT license <http://lodash.com/license> + */ +;(function() { + + /** Used as a safe reference for `undefined` in pre ES5 environments */ + var undefined; + + /** Used to pool arrays and objects used internally */ + var arrayPool = [], + objectPool = []; + + /** Used to generate unique IDs */ + var idCounter = 0; + + /** Used to prefix keys to avoid issues with `__proto__` and properties on `Object.prototype` */ + var keyPrefix = +new Date + ''; + + /** Used as the size when optimizations are enabled for large arrays */ + var largeArraySize = 75; + + /** Used as the max size of the `arrayPool` and `objectPool` */ + var maxPoolSize = 40; + + /** Used to detect and test whitespace */ + var whitespace = ( + // whitespace + ' \t\x0B\f\xA0\ufeff' + + + // line terminators + '\n\r\u2028\u2029' + + + // unicode category "Zs" space separators + '\u1680\u180e\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u202f\u205f\u3000' + ); + + /** Used to match empty string literals in compiled template source */ + var reEmptyStringLeading = /\b__p \+= '';/g, + reEmptyStringMiddle = /\b(__p \+=) '' \+/g, + reEmptyStringTrailing = /(__e\(.*?\)|\b__t\)) \+\n'';/g; + + /** + * Used to match ES6 template delimiters + * http://people.mozilla.org/~jorendorff/es6-draft.html#sec-literals-string-literals + */ + var reEsTemplate = /\$\{([^\\}]*(?:\\.[^\\}]*)*)\}/g; + + /** Used to match regexp flags from their coerced string values */ + var reFlags = /\w*$/; + + /** Used to detected named functions */ + var reFuncName = /^\s*function[ \n\r\t]+\w/; + + /** Used to match "interpolate" template delimiters */ + var reInterpolate = /<%=([\s\S]+?)%>/g; + + /** Used to match leading whitespace and zeros to be removed */ + var reLeadingSpacesAndZeros = RegExp('^[' + whitespace + ']*0+(?=.$)'); + + /** Used to ensure capturing order of template delimiters */ + var reNoMatch = /($^)/; + + /** Used to detect functions containing a `this` reference */ + var reThis = /\bthis\b/; + + /** Used to match unescaped characters in compiled string literals */ + var reUnescapedString = /['\n\r\t\u2028\u2029\\]/g; + + /** Used to assign default `context` object properties */ + var contextProps = [ + 'Array', 'Boolean', 'Date', 'Function', 'Math', 'Number', 'Object', + 'RegExp', 'String', '_', 'attachEvent', 'clearTimeout', 'isFinite', 'isNaN', + 'parseInt', 'setTimeout' + ]; + + /** Used to make template sourceURLs easier to identify */ + var templateCounter = 0; + + /** `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 identify object classifications that `_.clone` supports */ + var cloneableClasses = {}; + cloneableClasses[funcClass] = false; + cloneableClasses[argsClass] = cloneableClasses[arrayClass] = + cloneableClasses[boolClass] = cloneableClasses[dateClass] = + cloneableClasses[numberClass] = cloneableClasses[objectClass] = + cloneableClasses[regexpClass] = cloneableClasses[stringClass] = true; + + /** Used as an internal `_.debounce` options object */ + var debounceOptions = { + 'leading': false, + 'maxWait': 0, + 'trailing': false + }; + + /** Used as the property descriptor for `__bindData__` */ + var descriptor = { + 'configurable': false, + 'enumerable': false, + 'value': null, + 'writable': false + }; + + /** 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; + } + + /** + * An implementation of `_.contains` for cache objects that mimics the return + * signature of `_.indexOf` by returning `0` if the value is found, else `-1`. + * + * @private + * @param {Object} cache The cache object to inspect. + * @param {*} value The value to search for. + * @returns {number} Returns `0` if `value` is found, else `-1`. + */ + function cacheIndexOf(cache, value) { + var type = typeof value; + cache = cache.cache; + + if (type == 'boolean' || value == null) { + return cache[value] ? 0 : -1; + } + if (type != 'number' && type != 'string') { + type = 'object'; + } + var key = type == 'number' ? value : keyPrefix + value; + cache = (cache = cache[type]) && cache[key]; + + return type == 'object' + ? (cache && baseIndexOf(cache, value) > -1 ? 0 : -1) + : (cache ? 0 : -1); + } + + /** + * Adds a given value to the corresponding cache object. + * + * @private + * @param {*} value The value to add to the cache. + */ + function cachePush(value) { + var cache = this.cache, + type = typeof value; + + if (type == 'boolean' || value == null) { + cache[value] = true; + } else { + if (type != 'number' && type != 'string') { + type = 'object'; + } + var key = type == 'number' ? value : keyPrefix + value, + typeCache = cache[type] || (cache[type] = {}); + + if (type == 'object') { + (typeCache[key] || (typeCache[key] = [])).push(value); + } else { + typeCache[key] = true; + } + } + } + + /** + * Used by `_.max` and `_.min` as the default callback when a given + * collection is a string value. + * + * @private + * @param {string} value The character to inspect. + * @returns {number} Returns the code unit of given character. + */ + function charAtCallback(value) { + return value.charCodeAt(0); + } + + /** + * Used by `sortBy` to compare transformed `collection` elements, stable sorting + * them in ascending order. + * + * @private + * @param {Object} a The object to compare to `b`. + * @param {Object} b The object to compare to `a`. + * @returns {number} Returns the sort order indicator of `1` or `-1`. + */ + function compareAscending(a, b) { + var ac = a.criteria, + bc = b.criteria, + index = -1, + length = ac.length; + + while (++index < length) { + var value = ac[index], + other = bc[index]; + + if (value !== other) { + if (value > other || typeof value == 'undefined') { + return 1; + } + if (value < other || typeof other == 'undefined') { + return -1; + } + } + } + // Fixes an `Array#sort` bug in the JS engine embedded in Adobe applications + // that causes it, under certain circumstances, to return the same value for + // `a` and `b`. See https://github.com/jashkenas/underscore/pull/1247 + // + // This also ensures a stable sort in V8 and other engines. + // See http://code.google.com/p/v8/issues/detail?id=90 + return a.index - b.index; + } + + /** + * Creates a cache object to optimize linear searches of large arrays. + * + * @private + * @param {Array} [array=[]] The array to search. + * @returns {null|Object} Returns the cache object or `null` if caching should not be used. + */ + function createCache(array) { + var index = -1, + length = array.length, + first = array[0], + mid = array[(length / 2) | 0], + last = array[length - 1]; + + if (first && typeof first == 'object' && + mid && typeof mid == 'object' && last && typeof last == 'object') { + return false; + } + var cache = getObject(); + cache['false'] = cache['null'] = cache['true'] = cache['undefined'] = false; + + var result = getObject(); + result.array = array; + result.cache = cache; + result.push = cachePush; + + while (++index < length) { + result.push(array[index]); + } + return result; + } + + /** + * 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]; + } + + /** + * Gets an array from the array pool or creates a new one if the pool is empty. + * + * @private + * @returns {Array} The array from the pool. + */ + function getArray() { + return arrayPool.pop() || []; + } + + /** + * Gets an object from the object pool or creates a new one if the pool is empty. + * + * @private + * @returns {Object} The object from the pool. + */ + function getObject() { + return objectPool.pop() || { + 'array': null, + 'cache': null, + 'criteria': null, + 'false': false, + 'index': 0, + 'null': false, + 'number': null, + 'object': null, + 'push': null, + 'string': null, + 'true': false, + 'undefined': false, + 'value': null + }; + } + + /** + * Releases the given array back to the array pool. + * + * @private + * @param {Array} [array] The array to release. + */ + function releaseArray(array) { + array.length = 0; + if (arrayPool.length < maxPoolSize) { + arrayPool.push(array); + } + } + + /** + * Releases the given object back to the object pool. + * + * @private + * @param {Object} [object] The object to release. + */ + function releaseObject(object) { + var cache = object.cache; + if (cache) { + releaseObject(cache); + } + object.array = object.cache = object.criteria = object.object = object.number = object.string = object.value = null; + if (objectPool.length < maxPoolSize) { + objectPool.push(object); + } + } + + /** + * 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; + } + + /*--------------------------------------------------------------------------*/ + + /** + * Create a new `lodash` function using the given context object. + * + * @static + * @memberOf _ + * @category Utilities + * @param {Object} [context=root] The context object. + * @returns {Function} Returns the `lodash` function. + */ + function runInContext(context) { + // Avoid issues with some ES3 environments that attempt to use values, named + // after built-in constructors like `Object`, for the creation of literals. + // ES5 clears this up by stating that literals must use built-in constructors. + // See http://es5.github.io/#x11.1.5. + context = context ? _.defaults(root.Object(), context, _.pick(root, contextProps)) : root; + + /** Native constructor references */ + var Array = context.Array, + Boolean = context.Boolean, + Date = context.Date, + Function = context.Function, + Math = context.Math, + Number = context.Number, + Object = context.Object, + RegExp = context.RegExp, + String = context.String, + TypeError = context.TypeError; + + /** + * 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 = context._; + + /** 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, + clearTimeout = context.clearTimeout, + floor = Math.floor, + fnToString = Function.prototype.toString, + getPrototypeOf = isNative(getPrototypeOf = Object.getPrototypeOf) && getPrototypeOf, + hasOwnProperty = objectProto.hasOwnProperty, + push = arrayRef.push, + setTimeout = context.setTimeout, + splice = arrayRef.splice, + unshift = arrayRef.unshift; + + /** Used to set meta data on functions */ + var defineProperty = (function() { + // IE 8 only accepts DOM elements + try { + var o = {}, + func = isNative(func = Object.defineProperty) && func, + result = func(o, o, o) && func; + } catch(e) { } + return result; + }()); + + /* Native method shortcuts for methods with the same name as other `lodash` methods */ + var nativeCreate = isNative(nativeCreate = Object.create) && nativeCreate, + nativeIsArray = isNative(nativeIsArray = Array.isArray) && nativeIsArray, + nativeIsFinite = context.isFinite, + nativeIsNaN = context.isNaN, + nativeKeys = isNative(nativeKeys = Object.keys) && nativeKeys, + nativeMax = Math.max, + nativeMin = Math.min, + nativeParseInt = context.parseInt, + nativeRandom = Math.random; + + /** Used to lookup a built-in constructor by [[Class]] */ + var ctorByClass = {}; + ctorByClass[arrayClass] = Array; + ctorByClass[boolClass] = Boolean; + ctorByClass[dateClass] = Date; + ctorByClass[funcClass] = Function; + ctorByClass[objectClass] = Object; + ctorByClass[numberClass] = Number; + ctorByClass[regexpClass] = RegExp; + ctorByClass[stringClass] = String; + + /*--------------------------------------------------------------------------*/ + + /** + * 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) { + // don't wrap if already wrapped, even if wrapped by a different `lodash` constructor + return (value && typeof value == 'object' && !isArray(value) && hasOwnProperty.call(value, '__wrapped__')) + ? 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 = lodash.support = {}; + + /** + * Detect if functions can be decompiled by `Function#toString` + * (all but PS3 and older Opera mobile browsers & avoided in Windows 8 apps). + * + * @memberOf _.support + * @type boolean + */ + support.funcDecomp = !isNative(context.WinRTError) && reThis.test(runInContext); + + /** + * Detect if `Function#name` is supported (all but IE). + * + * @memberOf _.support + * @type boolean + */ + support.funcNames = typeof Function.name == 'string'; + + /** + * 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': '', + + /** + * Used to import variables into the compiled template. + * + * @memberOf _.templateSettings + * @type Object + */ + 'imports': { + + /** + * A reference to the `lodash` function. + * + * @memberOf _.templateSettings.imports + * @type Function + */ + '_': lodash + } + }; + + /*--------------------------------------------------------------------------*/ + + /** + * 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) { + // avoid `arguments` object deoptimizations by using `slice` instead + // of `Array.prototype.slice.call` and not assigning `arguments` to a + // variable as a ternary expression + var args = slice(partialArgs); + 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); + } + setBindData(bound, bindData); + return bound; + } + + /** + * The base implementation of `_.clone` without argument juggling or support + * for `thisArg` binding. + * + * @private + * @param {*} value The value to clone. + * @param {boolean} [isDeep=false] Specify a deep clone. + * @param {Function} [callback] The function to customize cloning values. + * @param {Array} [stackA=[]] Tracks traversed source objects. + * @param {Array} [stackB=[]] Associates clones with source counterparts. + * @returns {*} Returns the cloned value. + */ + function baseClone(value, isDeep, callback, stackA, stackB) { + if (callback) { + var result = callback(value); + if (typeof result != 'undefined') { + return result; + } + } + // inspect [[Class]] + var isObj = isObject(value); + if (isObj) { + var className = toString.call(value); + if (!cloneableClasses[className]) { + return value; + } + var ctor = ctorByClass[className]; + switch (className) { + case boolClass: + case dateClass: + return new ctor(+value); + + case numberClass: + case stringClass: + return new ctor(value); + + case regexpClass: + result = ctor(value.source, reFlags.exec(value)); + result.lastIndex = value.lastIndex; + return result; + } + } else { + return value; + } + var isArr = isArray(value); + if (isDeep) { + // check for circular references and return corresponding clone + var initedStack = !stackA; + stackA || (stackA = getArray()); + stackB || (stackB = getArray()); + + var length = stackA.length; + while (length--) { + if (stackA[length] == value) { + return stackB[length]; + } + } + result = isArr ? ctor(value.length) : {}; + } + else { + result = isArr ? slice(value) : assign({}, value); + } + // add array properties assigned by `RegExp#exec` + if (isArr) { + if (hasOwnProperty.call(value, 'index')) { + result.index = value.index; + } + if (hasOwnProperty.call(value, 'input')) { + result.input = value.input; + } + } + // exit for shallow clone + if (!isDeep) { + return result; + } + // add the source value to the stack of traversed objects + // and associate it with its clone + stackA.push(value); + stackB.push(result); + + // recursively populate clone (susceptible to call stack limits) + (isArr ? forEach : forOwn)(value, function(objValue, key) { + result[key] = baseClone(objValue, isDeep, callback, stackA, stackB); + }); + + if (initedStack) { + releaseArray(stackA); + releaseArray(stackB); + } + return result; + } + + /** + * 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 || context.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; + } + var bindData = func.__bindData__; + if (typeof bindData == 'undefined') { + if (support.funcNames) { + bindData = !func.name; + } + bindData = bindData || !support.funcDecomp; + if (!bindData) { + var source = fnToString.call(func); + if (!support.funcNames) { + bindData = !reFuncName.test(source); + } + if (!bindData) { + // checks if `func` references the `this` keyword and stores the result + bindData = reThis.test(source); + setBindData(func, bindData); + } + } + } + // exit early if there are no `this` references or `func` is bound + if (bindData === false || (bindData !== true && bindData[1] & 1)) { + 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 = slice(partialArgs); + 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); + } + setBindData(bound, bindData); + 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, + isLarge = length >= largeArraySize && indexOf === baseIndexOf, + result = []; + + if (isLarge) { + var cache = createCache(values); + if (cache) { + indexOf = cacheIndexOf; + values = cache; + } else { + isLarge = false; + } + } + while (++index < length) { + var value = array[index]; + if (indexOf(values, value) < 0) { + result.push(value); + } + } + if (isLarge) { + releaseObject(values); + } + 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, callback, isWhere, stackA, stackB) { + // used to indicate that when comparing objects, `a` has at least the properties of `b` + if (callback) { + var result = callback(a, b); + if (typeof result != 'undefined') { + return !!result; + } + } + // exit early for identical values + if (a === b) { + // treat `+0` vs. `-0` as not equal + return a !== 0 || (1 / a == 1 / b); + } + var type = typeof a, + otherType = typeof b; + + // exit early for unlike primitive values + if (a === a && + !(a && objectTypes[type]) && + !(b && objectTypes[otherType])) { + return false; + } + // exit early for `null` and `undefined` avoiding ES3's Function#call behavior + // http://es5.github.io/#x15.3.4.4 + if (a == null || b == null) { + return a === b; + } + // compare [[Class]] names + var className = toString.call(a), + otherClass = toString.call(b); + + if (className == argsClass) { + className = objectClass; + } + if (otherClass == argsClass) { + otherClass = objectClass; + } + if (className != otherClass) { + return false; + } + switch (className) { + case boolClass: + case dateClass: + // coerce dates and booleans to numbers, dates to milliseconds and booleans + // to `1` or `0` treating invalid dates coerced to `NaN` as not equal + return +a == +b; + + case numberClass: + // treat `NaN` vs. `NaN` as equal + return (a != +a) + ? b != +b + // but treat `+0` vs. `-0` as not equal + : (a == 0 ? (1 / a == 1 / b) : a == +b); + + case regexpClass: + case stringClass: + // coerce regexes to strings (http://es5.github.io/#x15.10.6.4) + // treat string primitives and their corresponding object instances as equal + return a == String(b); + } + var isArr = className == arrayClass; + if (!isArr) { + // unwrap any `lodash` wrapped values + var aWrapped = hasOwnProperty.call(a, '__wrapped__'), + bWrapped = hasOwnProperty.call(b, '__wrapped__'); + + if (aWrapped || bWrapped) { + return baseIsEqual(aWrapped ? a.__wrapped__ : a, bWrapped ? b.__wrapped__ : b, callback, isWhere, stackA, stackB); + } + // exit for functions and DOM nodes + if (className != objectClass) { + return false; + } + // in older versions of Opera, `arguments` objects have `Array` constructors + var ctorA = a.constructor, + ctorB = b.constructor; + + // non `Object` object instances with different constructors are not equal + if (ctorA != ctorB && + !(isFunction(ctorA) && ctorA instanceof ctorA && isFunction(ctorB) && ctorB instanceof ctorB) && + ('constructor' in a && 'constructor' in b) + ) { + return false; + } + } + // assume cyclic structures are equal + // the algorithm for detecting cyclic structures is adapted from ES 5.1 + // section 15.12.3, abstract operation `JO` (http://es5.github.io/#x15.12.3) + var initedStack = !stackA; + stackA || (stackA = getArray()); + stackB || (stackB = getArray()); + + var length = stackA.length; + while (length--) { + if (stackA[length] == a) { + return stackB[length] == b; + } + } + var size = 0; + result = true; + + // add `a` and `b` to the stack of traversed objects + stackA.push(a); + stackB.push(b); + + // recursively compare objects and arrays (susceptible to call stack limits) + if (isArr) { + // compare lengths to determine if a deep comparison is necessary + length = a.length; + size = b.length; + result = size == length; + + if (result || isWhere) { + // deep compare the contents, ignoring non-numeric properties + while (size--) { + var index = length, + value = b[size]; + + if (isWhere) { + while (index--) { + if ((result = baseIsEqual(a[index], value, callback, isWhere, stackA, stackB))) { + break; + } + } + } else if (!(result = baseIsEqual(a[size], value, callback, isWhere, stackA, stackB))) { + break; + } + } + } + } + else { + // deep compare objects using `forIn`, instead of `forOwn`, to avoid `Object.keys` + // which, in this case, is more costly + forIn(b, function(value, key, b) { + if (hasOwnProperty.call(b, key)) { + // count the number of properties. + size++; + // deep compare each property value. + return (result = hasOwnProperty.call(a, key) && baseIsEqual(a[key], value, callback, isWhere, stackA, stackB)); + } + }); + + if (result && !isWhere) { + // ensure both objects have the same number of properties + forIn(a, function(value, key, a) { + if (hasOwnProperty.call(a, key)) { + // `size` will be `-1` if `a` has more properties than `b` + return (result = --size > -1); + } + }); + } + } + stackA.pop(); + stackB.pop(); + + if (initedStack) { + releaseArray(stackA); + releaseArray(stackB); + } + return result; + } + + /** + * The base implementation of `_.merge` without argument juggling or support + * for `thisArg` binding. + * + * @private + * @param {Object} object The destination object. + * @param {Object} source The source object. + * @param {Function} [callback] The function to customize merging properties. + * @param {Array} [stackA=[]] Tracks traversed source objects. + * @param {Array} [stackB=[]] Associates values with source counterparts. + */ + function baseMerge(object, source, callback, stackA, stackB) { + (isArray(source) ? forEach : forOwn)(source, function(source, key) { + var found, + isArr, + result = source, + value = object[key]; + + if (source && ((isArr = isArray(source)) || isPlainObject(source))) { + // avoid merging previously merged cyclic sources + var stackLength = stackA.length; + while (stackLength--) { + if ((found = stackA[stackLength] == source)) { + value = stackB[stackLength]; + break; + } + } + if (!found) { + var isShallow; + if (callback) { + result = callback(value, source); + if ((isShallow = typeof result != 'undefined')) { + value = result; + } + } + if (!isShallow) { + value = isArr + ? (isArray(value) ? value : []) + : (isPlainObject(value) ? value : {}); + } + // add `source` and associated `value` to the stack of traversed objects + stackA.push(source); + stackB.push(value); + + // recursively merge objects and arrays (susceptible to call stack limits) + if (!isShallow) { + baseMerge(value, source, callback, stackA, stackB); + } + } + } + else { + if (callback) { + result = callback(value, source); + if (typeof result == 'undefined') { + result = source; + } + } + if (typeof result != 'undefined') { + value = result; + } + } + object[key] = value; + }); + } + + /** + * 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 = []; + + var isLarge = !isSorted && length >= largeArraySize && indexOf === baseIndexOf, + seen = (callback || isLarge) ? getArray() : result; + + if (isLarge) { + var cache = createCache(seen); + indexOf = cacheIndexOf; + seen = cache; + } + 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 || isLarge) { + seen.push(computed); + } + result.push(value); + } + } + if (isLarge) { + releaseArray(seen.array); + releaseObject(seen); + } else if (callback) { + releaseArray(seen); + } + 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 = lodash.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; + } + var bindData = func && func.__bindData__; + if (bindData && bindData !== true) { + // clone `bindData` + bindData = slice(bindData); + if (bindData[2]) { + bindData[2] = slice(bindData[2]); + } + if (bindData[3]) { + bindData[3] = slice(bindData[3]); + } + // set `thisBinding` is not previously bound + if (isBind && !(bindData[1] & 1)) { + bindData[4] = thisArg; + } + // set if previously bound but not currently (subsequent curried functions) + if (!isBind && bindData[1] & 1) { + bitmask |= 8; + } + // set curried arity if not yet set + if (isCurry && !(bindData[1] & 4)) { + bindData[5] = arity; + } + // append partial left arguments + if (isPartial) { + push.apply(bindData[2] || (bindData[2] = []), partialArgs); + } + // append partial right arguments + if (isPartialRight) { + unshift.apply(bindData[3] || (bindData[3] = []), partialRightArgs); + } + // merge flags + bindData[1] |= bitmask; + return createWrapper.apply(null, bindData); + } + // 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; + } + + /** + * Checks if `value` is a native function. + * + * @private + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if the `value` is a native function, else `false`. + */ + function isNative(value) { + return typeof value == 'function' && reNative.test(value); + } + + /** + * Sets `this` binding data on a given function. + * + * @private + * @param {Function} func The function to set data on. + * @param {Array} value The data array to set. + */ + var setBindData = !defineProperty ? noop : function(func, value) { + descriptor.value = value; + defineProperty(func, '__bindData__', descriptor); + }; + + /** + * A fallback implementation of `isPlainObject` which checks if a given value + * is an object created by the `Object` constructor, assuming objects created + * by the `Object` constructor have no inherited enumerable properties and that + * there are no `Object.prototype` extensions. + * + * @private + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is a plain object, else `false`. + */ + function shimIsPlainObject(value) { + var ctor, + result; + + // avoid non Object objects, `arguments` objects, and DOM elements + if (!(value && toString.call(value) == objectClass) || + (ctor = value.constructor, isFunction(ctor) && !(ctor instanceof ctor))) { + return false; + } + // In most environments an object's own properties are iterated before + // its inherited properties. If the last iterated property is an object's + // own property then there are no inherited enumerable properties. + forIn(value, function(value, key) { + result = key; + }); + return typeof result == 'undefined' || hasOwnProperty.call(value, 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; + } + + /** + * 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' } + */ + var assign = function(object, source, guard) { + var index, iterable = object, result = iterable; + if (!iterable) return result; + var args = arguments, + argsIndex = 0, + argsLength = typeof guard == 'number' ? 2 : args.length; + if (argsLength > 3 && typeof args[argsLength - 2] == 'function') { + var callback = baseCreateCallback(args[--argsLength - 1], args[argsLength--], 2); + } else if (argsLength > 2 && typeof args[argsLength - 1] == 'function') { + callback = args[--argsLength]; + } + while (++argsIndex < argsLength) { + iterable = args[argsIndex]; + if (iterable && objectTypes[typeof iterable]) { + var ownIndex = -1, + ownProps = objectTypes[typeof iterable] && keys(iterable), + length = ownProps ? ownProps.length : 0; + + while (++ownIndex < length) { + index = ownProps[ownIndex]; + result[index] = callback ? callback(result[index], iterable[index]) : iterable[index]; + } + } + } + return result + }; + + /** + * 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, isDeep, callback, thisArg) { + // allows working with "Collections" methods without using their `index` + // and `collection` arguments for `isDeep` and `callback` + if (typeof isDeep != 'boolean' && isDeep != null) { + thisArg = callback; + callback = isDeep; + isDeep = false; + } + return baseClone(value, isDeep, typeof callback == 'function' && baseCreateCallback(callback, thisArg, 1)); + } + + /** + * Creates a deep clone of `value`. If a callback is provided it will be + * executed to produce the cloned values. If the callback returns `undefined` + * cloning will be handled by the method instead. The callback is bound to + * `thisArg` and invoked with one argument; (value). + * + * Note: This method is loosely based on the structured clone algorithm. Functions + * and DOM nodes are **not** cloned. The enumerable properties of `arguments` objects and + * objects created by constructors other than `Object` are cloned to plain `Object` objects. + * See http://www.w3.org/TR/html5/infrastructure.html#internal-structured-cloning-algorithm. + * + * @static + * @memberOf _ + * @category Objects + * @param {*} value The value to deep clone. + * @param {Function} [callback] The function to customize cloning values. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {*} Returns the deep cloned value. + * @example + * + * var characters = [ + * { 'name': 'barney', 'age': 36 }, + * { 'name': 'fred', 'age': 40 } + * ]; + * + * var deep = _.cloneDeep(characters); + * deep[0] === characters[0]; + * // => false + * + * var view = { + * 'label': 'docs', + * 'node': element + * }; + * + * var clone = _.cloneDeep(view, function(value) { + * return _.isElement(value) ? value.cloneNode(true) : undefined; + * }); + * + * clone.node == view.node; + * // => false + */ + function cloneDeep(value, callback, thisArg) { + return baseClone(value, true, typeof callback == 'function' && baseCreateCallback(callback, thisArg, 1)); + } + + /** + * Creates an object that inherits from the given `prototype` object. If a + * `properties` object is provided its own enumerable properties are assigned + * to the created object. + * + * @static + * @memberOf _ + * @category Objects + * @param {Object} prototype The object to inherit from. + * @param {Object} [properties] The properties to assign to the object. + * @returns {Object} Returns the new object. + * @example + * + * function Shape() { + * this.x = 0; + * this.y = 0; + * } + * + * function Circle() { + * Shape.call(this); + * } + * + * Circle.prototype = _.create(Shape.prototype, { 'constructor': Circle }); + * + * var circle = new Circle; + * circle instanceof Circle; + * // => true + * + * circle instanceof Shape; + * // => true + */ + function create(prototype, properties) { + var result = baseCreate(prototype); + return properties ? assign(result, properties) : result; + } + + /** + * 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' } + */ + var defaults = function(object, source, guard) { + var index, iterable = object, result = iterable; + if (!iterable) return result; + var args = arguments, + argsIndex = 0, + argsLength = typeof guard == 'number' ? 2 : args.length; + while (++argsIndex < argsLength) { + iterable = args[argsIndex]; + if (iterable && objectTypes[typeof iterable]) { + var ownIndex = -1, + ownProps = objectTypes[typeof iterable] && keys(iterable), + length = ownProps ? ownProps.length : 0; + + while (++ownIndex < length) { + index = ownProps[ownIndex]; + if (typeof result[index] == 'undefined') result[index] = iterable[index]; + } + } + } + return result + }; + + /** + * This method is like `_.findIndex` except that it returns the key of the + * first element that passes the callback check, instead of the element itself. + * + * 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 Objects + * @param {Object} object The object to search. + * @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 {string|undefined} Returns the key of the found element, else `undefined`. + * @example + * + * var characters = { + * 'barney': { 'age': 36, 'blocked': false }, + * 'fred': { 'age': 40, 'blocked': true }, + * 'pebbles': { 'age': 1, 'blocked': false } + * }; + * + * _.findKey(characters, function(chr) { + * return chr.age < 40; + * }); + * // => 'barney' (property order is not guaranteed across environments) + * + * // using "_.where" callback shorthand + * _.findKey(characters, { 'age': 1 }); + * // => 'pebbles' + * + * // using "_.pluck" callback shorthand + * _.findKey(characters, 'blocked'); + * // => 'fred' + */ + function findKey(object, callback, thisArg) { + var result; + callback = lodash.createCallback(callback, thisArg, 3); + forOwn(object, function(value, key, object) { + if (callback(value, key, object)) { + result = key; + return false; + } + }); + return result; + } + + /** + * This method is like `_.findKey` except that it iterates over elements + * of a `collection` in the opposite order. + * + * 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 Objects + * @param {Object} object The object to search. + * @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 {string|undefined} Returns the key of the found element, else `undefined`. + * @example + * + * var characters = { + * 'barney': { 'age': 36, 'blocked': true }, + * 'fred': { 'age': 40, 'blocked': false }, + * 'pebbles': { 'age': 1, 'blocked': true } + * }; + * + * _.findLastKey(characters, function(chr) { + * return chr.age < 40; + * }); + * // => returns `pebbles`, assuming `_.findKey` returns `barney` + * + * // using "_.where" callback shorthand + * _.findLastKey(characters, { 'age': 40 }); + * // => 'fred' + * + * // using "_.pluck" callback shorthand + * _.findLastKey(characters, 'blocked'); + * // => 'pebbles' + */ + function findLastKey(object, callback, thisArg) { + var result; + callback = lodash.createCallback(callback, thisArg, 3); + forOwnRight(object, function(value, key, object) { + if (callback(value, key, object)) { + result = key; + return false; + } + }); + return result; + } + + /** + * 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, thisArg) { + var index, iterable = collection, result = iterable; + if (!iterable) return result; + if (!objectTypes[typeof iterable]) return result; + callback = callback && typeof thisArg == 'undefined' ? callback : baseCreateCallback(callback, thisArg, 3); + for (index in iterable) { + if (callback(iterable[index], index, collection) === false) return result; + } + return result + }; + + /** + * This method is like `_.forIn` except that it iterates over elements + * of a `collection` in the opposite order. + * + * @static + * @memberOf _ + * @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; + * }; + * + * _.forInRight(new Shape, function(value, key) { + * console.log(key); + * }); + * // => logs 'move', 'y', and 'x' assuming `_.forIn ` logs 'x', 'y', and 'move' + */ + function forInRight(object, callback, thisArg) { + var pairs = []; + + forIn(object, function(value, key) { + pairs.push(key, value); + }); + + var length = pairs.length; + callback = baseCreateCallback(callback, thisArg, 3); + while (length--) { + if (callback(pairs[length--], pairs[length], object) === false) { + break; + } + } + return object; + } + + /** + * 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, thisArg) { + var index, iterable = collection, result = iterable; + if (!iterable) return result; + if (!objectTypes[typeof iterable]) return result; + callback = callback && typeof thisArg == 'undefined' ? callback : baseCreateCallback(callback, thisArg, 3); + var ownIndex = -1, + ownProps = objectTypes[typeof iterable] && keys(iterable), + length = ownProps ? ownProps.length : 0; + + while (++ownIndex < length) { + index = ownProps[ownIndex]; + if (callback(iterable[index], index, collection) === false) return result; + } + return result + }; + + /** + * This method is like `_.forOwn` except that it iterates over elements + * of a `collection` in the opposite order. + * + * @static + * @memberOf _ + * @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 + * + * _.forOwnRight({ '0': 'zero', '1': 'one', 'length': 2 }, function(num, key) { + * console.log(key); + * }); + * // => logs 'length', '1', and '0' assuming `_.forOwn` logs '0', '1', and 'length' + */ + function forOwnRight(object, callback, thisArg) { + var props = keys(object), + length = props.length; + + callback = baseCreateCallback(callback, thisArg, 3); + while (length--) { + var key = props[length]; + if (callback(object[key], key, object) === false) { + break; + } + } + return object; + } + + /** + * Creates a sorted array of property names of all enumerable properties, + * own and inherited, of `object` that have function values. + * + * @static + * @memberOf _ + * @alias methods + * @category Objects + * @param {Object} object The object to inspect. + * @returns {Array} Returns an array of property names that have function values. + * @example + * + * _.functions(_); + * // => ['all', 'any', 'bind', 'bindAll', 'clone', 'compact', 'compose', ...] + */ + function functions(object) { + var result = []; + forIn(object, function(value, key) { + if (isFunction(value)) { + result.push(key); + } + }); + return result.sort(); + } + + /** + * Checks if the specified property name exists as a direct property of `object`, + * instead of an inherited property. + * + * @static + * @memberOf _ + * @category Objects + * @param {Object} object The object to inspect. + * @param {string} key The name of the property to check. + * @returns {boolean} Returns `true` if key is a direct property, else `false`. + * @example + * + * _.has({ 'a': 1, 'b': 2, 'c': 3 }, 'b'); + * // => true + */ + function has(object, key) { + return object ? hasOwnProperty.call(object, key) : false; + } + + /** + * Creates an object composed of the inverted keys and values of the given object. + * + * @static + * @memberOf _ + * @category Objects + * @param {Object} object The object to invert. + * @returns {Object} Returns the created inverted object. + * @example + * + * _.invert({ 'first': 'fred', 'second': 'barney' }); + * // => { 'fred': 'first', 'barney': 'second' } + */ + function invert(object) { + var index = -1, + props = keys(object), + length = props.length, + result = {}; + + while (++index < length) { + var key = props[index]; + result[object[key]] = key; + } + return result; + } + + /** + * Checks if `value` is a boolean value. + * + * @static + * @memberOf _ + * @category Objects + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if the `value` is a boolean value, else `false`. + * @example + * + * _.isBoolean(null); + * // => false + */ + function isBoolean(value) { + return value === true || value === false || + value && typeof value == 'object' && toString.call(value) == boolClass || false; + } + + /** + * Checks if `value` is a date. + * + * @static + * @memberOf _ + * @category Objects + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if the `value` is a date, else `false`. + * @example + * + * _.isDate(new Date); + * // => true + */ + function isDate(value) { + return value && typeof value == 'object' && toString.call(value) == dateClass || false; + } + + /** + * Checks if `value` is a DOM element. + * + * @static + * @memberOf _ + * @category Objects + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if the `value` is a DOM element, else `false`. + * @example + * + * _.isElement(document.body); + * // => true + */ + function isElement(value) { + return value && value.nodeType === 1 || false; + } + + /** + * Checks if `value` is empty. Arrays, strings, or `arguments` objects with a + * length of `0` and objects with no own enumerable properties are considered + * "empty". + * + * @static + * @memberOf _ + * @category Objects + * @param {Array|Object|string} value The value to inspect. + * @returns {boolean} Returns `true` if the `value` is empty, else `false`. + * @example + * + * _.isEmpty([1, 2, 3]); + * // => false + * + * _.isEmpty({}); + * // => true + * + * _.isEmpty(''); + * // => true + */ + function isEmpty(value) { + var result = true; + if (!value) { + return result; + } + var className = toString.call(value), + length = value.length; + + if ((className == arrayClass || className == stringClass || className == argsClass ) || + (className == objectClass && typeof length == 'number' && isFunction(value.splice))) { + return !length; + } + forOwn(value, function() { + return (result = false); + }); + return result; + } + + /** + * 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, callback, thisArg) { + return baseIsEqual(a, b, typeof callback == 'function' && baseCreateCallback(callback, thisArg, 2)); + } + + /** + * 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'; + } + + /** + * 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 an object created by the `Object` constructor. + * + * @static + * @memberOf _ + * @category Objects + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is a plain object, else `false`. + * @example + * + * function Shape() { + * this.x = 0; + * this.y = 0; + * } + * + * _.isPlainObject(new Shape); + * // => false + * + * _.isPlainObject([1, 2, 3]); + * // => false + * + * _.isPlainObject({ 'x': 0, 'y': 0 }); + * // => true + */ + var isPlainObject = !getPrototypeOf ? shimIsPlainObject : function(value) { + if (!(value && toString.call(value) == objectClass)) { + return false; + } + var valueOf = value.valueOf, + objProto = isNative(valueOf) && (objProto = getPrototypeOf(valueOf)) && getPrototypeOf(objProto); + + return objProto + ? (value == objProto || getPrototypeOf(value) == objProto) + : shimIsPlainObject(value); + }; + + /** + * 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 && typeof value == 'object' && toString.call(value) == regexpClass || false; + } + + /** + * Checks if `value` is a string. + * + * @static + * @memberOf _ + * @category Objects + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if 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 an object with the same keys as `object` and values generated by + * running each own enumerable property of `object` through the callback. + * The callback is bound to `thisArg` and invoked with three arguments; + * (value, key, object). + * + * 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 Objects + * @param {Object} object The object 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 object with values of the results of each `callback` execution. + * @example + * + * _.mapValues({ 'a': 1, 'b': 2, 'c': 3} , function(num) { return num * 3; }); + * // => { 'a': 3, 'b': 6, 'c': 9 } + * + * var characters = { + * 'fred': { 'name': 'fred', 'age': 40 }, + * 'pebbles': { 'name': 'pebbles', 'age': 1 } + * }; + * + * // using "_.pluck" callback shorthand + * _.mapValues(characters, 'age'); + * // => { 'fred': 40, 'pebbles': 1 } + */ + function mapValues(object, callback, thisArg) { + var result = {}; + callback = lodash.createCallback(callback, thisArg, 3); + + forOwn(object, function(value, key, object) { + result[key] = callback(value, key, object); + }); + return result; + } + + /** + * Recursively merges own enumerable properties of the source object(s), that + * don't resolve to `undefined` into the destination object. Subsequent sources + * will overwrite property assignments of previous sources. If a callback is + * provided it will be executed to produce the merged values of the destination + * and source properties. If the callback returns `undefined` merging will + * be handled by the method instead. The callback is bound to `thisArg` and + * invoked with two arguments; (objectValue, sourceValue). + * + * @static + * @memberOf _ + * @category Objects + * @param {Object} object The destination object. + * @param {...Object} [source] The source objects. + * @param {Function} [callback] The function to customize merging properties. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Object} Returns the destination object. + * @example + * + * var names = { + * 'characters': [ + * { 'name': 'barney' }, + * { 'name': 'fred' } + * ] + * }; + * + * var ages = { + * 'characters': [ + * { 'age': 36 }, + * { 'age': 40 } + * ] + * }; + * + * _.merge(names, ages); + * // => { 'characters': [{ 'name': 'barney', 'age': 36 }, { 'name': 'fred', 'age': 40 }] } + * + * var food = { + * 'fruits': ['apple'], + * 'vegetables': ['beet'] + * }; + * + * var otherFood = { + * 'fruits': ['banana'], + * 'vegetables': ['carrot'] + * }; + * + * _.merge(food, otherFood, function(a, b) { + * return _.isArray(a) ? a.concat(b) : undefined; + * }); + * // => { 'fruits': ['apple', 'banana'], 'vegetables': ['beet', 'carrot] } + */ + function merge(object) { + var args = arguments, + length = 2; + + if (!isObject(object)) { + return object; + } + // allows working with `_.reduce` and `_.reduceRight` without using + // their `index` and `collection` arguments + if (typeof args[2] != 'number') { + length = args.length; + } + if (length > 3 && typeof args[length - 2] == 'function') { + var callback = baseCreateCallback(args[--length - 1], args[length--], 2); + } else if (length > 2 && typeof args[length - 1] == 'function') { + callback = args[--length]; + } + var sources = slice(arguments, 1, length), + index = -1, + stackA = getArray(), + stackB = getArray(); + + while (++index < length) { + baseMerge(object, sources[index], callback, stackA, stackB); + } + releaseArray(stackA); + releaseArray(stackB); + return object; + } + + /** + * 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, callback, thisArg) { + var result = {}; + if (typeof callback != 'function') { + var props = []; + forIn(object, function(value, key) { + props.push(key); + }); + props = baseDifference(props, baseFlatten(arguments, true, false, 1)); + + var index = -1, + length = props.length; + + while (++index < length) { + var key = props[index]; + result[key] = object[key]; + } + } else { + callback = lodash.createCallback(callback, thisArg, 3); + forIn(object, function(value, key, object) { + if (!callback(value, key, object)) { + result[key] = value; + } + }); + } + 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, callback, thisArg) { + var result = {}; + if (typeof callback != 'function') { + var index = -1, + props = baseFlatten(arguments, true, false, 1), + length = isObject(object) ? props.length : 0; + + while (++index < length) { + var key = props[index]; + if (key in object) { + result[key] = object[key]; + } + } + } else { + callback = lodash.createCallback(callback, thisArg, 3); + forIn(object, function(value, key, object) { + if (callback(value, key, object)) { + result[key] = value; + } + }); + } + return result; + } + + /** + * An alternative to `_.reduce` this method transforms `object` to a new + * `accumulator` object which is the result of running each of its own + * enumerable properties through a callback, with each callback execution + * potentially mutating the `accumulator` object. The callback is bound to + * `thisArg` and invoked with four arguments; (accumulator, value, key, object). + * Callbacks may exit iteration early by explicitly returning `false`. + * + * @static + * @memberOf _ + * @category Objects + * @param {Array|Object} object The object to iterate over. + * @param {Function} [callback=identity] The function called per iteration. + * @param {*} [accumulator] The custom accumulator value. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {*} Returns the accumulated value. + * @example + * + * var squares = _.transform([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], function(result, num) { + * num *= num; + * if (num % 2) { + * return result.push(num) < 3; + * } + * }); + * // => [1, 9, 25] + * + * var mapped = _.transform({ 'a': 1, 'b': 2, 'c': 3 }, function(result, num, key) { + * result[key] = num * 3; + * }); + * // => { 'a': 3, 'b': 6, 'c': 9 } + */ + function transform(object, callback, accumulator, thisArg) { + var isArr = isArray(object); + if (accumulator == null) { + if (isArr) { + accumulator = []; + } else { + var ctor = object && object.constructor, + proto = ctor && ctor.prototype; + + accumulator = baseCreate(proto); + } + } + if (callback) { + callback = lodash.createCallback(callback, thisArg, 4); + (isArr ? forEach : forOwn)(object, function(value, index, object) { + return callback(accumulator, value, index, object); + }); + } + return accumulator; + } + + /** + * 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; + } + + /*--------------------------------------------------------------------------*/ + + /** + * Creates an array of elements from the specified indexes, or keys, of the + * `collection`. Indexes may be specified as individual arguments or as arrays + * of indexes. + * + * @static + * @memberOf _ + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {...(number|number[]|string|string[])} [index] The indexes of `collection` + * to retrieve, specified as individual indexes or arrays of indexes. + * @returns {Array} Returns a new array of elements corresponding to the + * provided indexes. + * @example + * + * _.at(['a', 'b', 'c', 'd', 'e'], [0, 2, 4]); + * // => ['a', 'c', 'e'] + * + * _.at(['fred', 'barney', 'pebbles'], 0, 2); + * // => ['fred', 'pebbles'] + */ + function at(collection) { + var args = arguments, + index = -1, + props = baseFlatten(args, true, false, 1), + length = (args[2] && args[2][args[1]] === collection) ? 1 : props.length, + result = Array(length); + + while(++index < length) { + result[index] = collection[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, fromIndex) { + var index = -1, + indexOf = getIndexOf(), + length = collection ? collection.length : 0, + result = false; + + fromIndex = (fromIndex < 0 ? nativeMax(0, length + fromIndex) : fromIndex) || 0; + if (isArray(collection)) { + result = indexOf(collection, target, fromIndex) > -1; + } else if (typeof length == 'number') { + result = (isString(collection) ? collection.indexOf(target, fromIndex) : indexOf(collection, target, fromIndex)) > -1; + } else { + forOwn(collection, function(value) { + if (++index >= fromIndex) { + return !(result = value === target); + } + }); + } + 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 = lodash.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)); + }); + } + 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 = lodash.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 = lodash.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 false; + } + }); + return result; + } + } + + /** + * This method is like `_.find` except that it iterates over elements + * of a `collection` from right to left. + * + * @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 found element, else `undefined`. + * @example + * + * _.findLast([1, 2, 3, 4], function(num) { + * return num % 2 == 1; + * }); + * // => 3 + */ + function findLast(collection, callback, thisArg) { + var result; + callback = lodash.createCallback(callback, thisArg, 3); + forEachRight(collection, function(value, index, collection) { + if (callback(value, index, collection)) { + result = value; + return false; + } + }); + return result; + } + + /** + * 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) === false) { + break; + } + } + } else { + forOwn(collection, callback); + } + return collection; + } + + /** + * 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, thisArg) { + var length = collection ? collection.length : 0; + callback = callback && typeof thisArg == 'undefined' ? callback : baseCreateCallback(callback, thisArg, 3); + 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); + }); + } + return collection; + } + + /** + * Creates an object composed of keys generated from the results of running + * each element of a collection through the callback. The corresponding value + * of each key is an array of the elements responsible for generating the key. + * The callback is bound to `thisArg` and invoked with three arguments; + * (value, index|key, collection). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false` + * + * @static + * @memberOf _ + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [callback=identity] The function called + * per iteration. If a property name or object is provided it will be used + * to create a "_.pluck" or "_.where" style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Object} Returns the composed aggregate object. + * @example + * + * _.groupBy([4.2, 6.1, 6.4], function(num) { return Math.floor(num); }); + * // => { '4': [4.2], '6': [6.1, 6.4] } + * + * _.groupBy([4.2, 6.1, 6.4], function(num) { return this.floor(num); }, Math); + * // => { '4': [4.2], '6': [6.1, 6.4] } + * + * // using "_.pluck" callback shorthand + * _.groupBy(['one', 'two', 'three'], 'length'); + * // => { '3': ['one', 'two'], '5': ['three'] } + */ + var groupBy = createAggregator(function(result, value, key) { + (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 = lodash.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; + } + if (callback == null && isArray(collection)) { + var index = -1, + length = collection.length; + + while (++index < length) { + var value = collection[index]; + if (value > result) { + result = value; + } + } + } else { + callback = (callback == null && isString(collection)) + ? charAtCallback + : lodash.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; + } + if (callback == null && isArray(collection)) { + var index = -1, + length = collection.length; + + while (++index < length) { + var value = collection[index]; + if (value < result) { + result = value; + } + } + } else { + callback = (callback == null && isString(collection)) + ? charAtCallback + : lodash.createCallback(callback, thisArg, 3); + + forEach(collection, function(value, index, collection) { + var current = callback(value, index, collection); + if (current < computed) { + computed = current; + result = value; + } + }); + } + return result; + } + + /** + * Retrieves the value of a specified property from all elements in the collection. + * + * @static + * @memberOf _ + * @type Function + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {string} property The name of the property to pluck. + * @returns {Array} Returns a new array of property values. + * @example + * + * var characters = [ + * { 'name': 'barney', 'age': 36 }, + * { 'name': 'fred', 'age': 40 } + * ]; + * + * _.pluck(characters, 'name'); + * // => ['barney', 'fred'] + */ + var pluck = map; + + /** + * Reduces a collection to a value which is the accumulated result of running + * each element in the collection through the callback, where each successive + * callback execution consumes the return value of the previous execution. If + * `accumulator` is not provided the first element of the collection will be + * used as the initial `accumulator` value. The callback is bound to `thisArg` + * and invoked with four arguments; (accumulator, value, index|key, collection). + * + * @static + * @memberOf _ + * @alias foldl, inject + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} [callback=identity] The function called per iteration. + * @param {*} [accumulator] Initial value of the accumulator. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {*} Returns the accumulated value. + * @example + * + * var sum = _.reduce([1, 2, 3], function(sum, num) { + * return sum + num; + * }); + * // => 6 + * + * var mapped = _.reduce({ 'a': 1, 'b': 2, 'c': 3 }, function(result, num, key) { + * result[key] = num * 3; + * return result; + * }, {}); + * // => { 'a': 3, 'b': 6, 'c': 9 } + */ + function reduce(collection, callback, accumulator, thisArg) { + if (!collection) return accumulator; + var noaccum = arguments.length < 3; + callback = lodash.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 = lodash.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 = lodash.createCallback(callback, thisArg, 3); + return filter(collection, function(value, index, collection) { + return !callback(value, index, collection); + }); + } + + /** + * Retrieves a random element or `n` random elements from a collection. + * + * @static + * @memberOf _ + * @category Collections + * @param {Array|Object|string} collection The collection to sample. + * @param {number} [n] The number of elements to sample. + * @param- {Object} [guard] Allows working with functions like `_.map` + * without using their `index` arguments as `n`. + * @returns {Array} Returns the random sample(s) of `collection`. + * @example + * + * _.sample([1, 2, 3, 4]); + * // => 2 + * + * _.sample([1, 2, 3, 4], 2); + * // => [3, 1] + */ + function sample(collection, n, guard) { + if (collection && typeof collection.length != 'number') { + collection = values(collection); + } + if (n == null || guard) { + return collection ? collection[baseRandom(0, collection.length - 1)] : undefined; + } + var result = shuffle(collection); + result.length = nativeMin(nativeMax(0, n), result.length); + return result; + } + + /** + * Creates an array of shuffled values, using a version of the Fisher-Yates + * shuffle. See http://en.wikipedia.org/wiki/Fisher-Yates_shuffle. + * + * @static + * @memberOf _ + * @category Collections + * @param {Array|Object|string} collection The collection to shuffle. + * @returns {Array} Returns a new shuffled collection. + * @example + * + * _.shuffle([1, 2, 3, 4, 5, 6]); + * // => [4, 1, 6, 3, 5, 2] + */ + function shuffle(collection) { + var index = -1, + length = collection ? collection.length : 0, + result = Array(typeof length == 'number' ? length : 0); + + forEach(collection, function(value) { + var rand = baseRandom(0, ++index); + result[index] = result[rand]; + result[rand] = value; + }); + return result; + } + + /** + * Gets the size of the `collection` by returning `collection.length` for arrays + * and array-like objects or the number of own enumerable properties for objects. + * + * @static + * @memberOf _ + * @category Collections + * @param {Array|Object|string} collection The collection to inspect. + * @returns {number} Returns `collection.length` or number of own enumerable properties. + * @example + * + * _.size([1, 2]); + * // => 2 + * + * _.size({ 'one': 1, 'two': 2, 'three': 3 }); + * // => 3 + * + * _.size('pebbles'); + * // => 7 + */ + function size(collection) { + var length = collection ? collection.length : 0; + return typeof length == 'number' ? length : keys(collection).length; + } + + /** + * Checks if the callback returns a truey value for **any** element of a + * collection. The function returns as soon as it finds a passing value and + * does not iterate over the entire collection. The callback is bound to + * `thisArg` and invoked with three arguments; (value, index|key, collection). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @alias any + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [callback=identity] The function called + * per iteration. If a property name or object is provided it will be used + * to create a "_.pluck" or "_.where" style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {boolean} Returns `true` if any element passed the callback check, + * else `false`. + * @example + * + * _.some([null, 0, 'yes', false], Boolean); + * // => true + * + * var characters = [ + * { 'name': 'barney', 'age': 36, 'blocked': false }, + * { 'name': 'fred', 'age': 40, 'blocked': true } + * ]; + * + * // using "_.pluck" callback shorthand + * _.some(characters, 'blocked'); + * // => true + * + * // using "_.where" callback shorthand + * _.some(characters, { 'age': 1 }); + * // => false + */ + function some(collection, callback, thisArg) { + var result; + callback = lodash.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)); + }); + } + return !!result; + } + + /** + * Creates an array of elements, sorted in ascending order by the results of + * running each element in a collection through the callback. This method + * performs a stable sort, that is, it will preserve the original sort order + * of equal elements. The callback is bound to `thisArg` and invoked with + * three arguments; (value, index|key, collection). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an array of property names is provided for `callback` the collection + * will be sorted by each property value. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Array|Function|Object|string} [callback=identity] The function called + * per iteration. If a property name or object is provided it will be used + * to create a "_.pluck" or "_.where" style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Array} Returns a new array of sorted elements. + * @example + * + * _.sortBy([1, 2, 3], function(num) { return Math.sin(num); }); + * // => [3, 1, 2] + * + * _.sortBy([1, 2, 3], function(num) { return this.sin(num); }, Math); + * // => [3, 1, 2] + * + * var characters = [ + * { 'name': 'barney', 'age': 36 }, + * { 'name': 'fred', 'age': 40 }, + * { 'name': 'barney', 'age': 26 }, + * { 'name': 'fred', 'age': 30 } + * ]; + * + * // using "_.pluck" callback shorthand + * _.map(_.sortBy(characters, 'age'), _.values); + * // => [['barney', 26], ['fred', 30], ['barney', 36], ['fred', 40]] + * + * // sorting by multiple properties + * _.map(_.sortBy(characters, ['name', 'age']), _.values); + * // = > [['barney', 26], ['barney', 36], ['fred', 30], ['fred', 40]] + */ + function sortBy(collection, callback, thisArg) { + var index = -1, + isArr = isArray(callback), + length = collection ? collection.length : 0, + result = Array(typeof length == 'number' ? length : 0); + + if (!isArr) { + callback = lodash.createCallback(callback, thisArg, 3); + } + forEach(collection, function(value, key, collection) { + var object = result[++index] = getObject(); + if (isArr) { + object.criteria = map(callback, function(key) { return value[key]; }); + } else { + (object.criteria = getArray())[0] = callback(value, key, collection); + } + object.index = index; + object.value = value; + }); + + length = result.length; + result.sort(compareAscending); + while (length--) { + var object = result[length]; + result[length] = object.value; + if (!isArr) { + releaseArray(object.criteria); + } + releaseObject(object); + } + 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 (collection && typeof collection.length == 'number') { + return slice(collection); + } + return values(collection); + } + + /** + * Performs a deep comparison of each element in a `collection` to the given + * `properties` object, returning an array of all elements that have equivalent + * property values. + * + * @static + * @memberOf _ + * @type Function + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Object} props The object of property values to filter by. + * @returns {Array} Returns a new array of elements that have the given properties. + * @example + * + * var characters = [ + * { 'name': 'barney', 'age': 36, 'pets': ['hoppy'] }, + * { 'name': 'fred', 'age': 40, 'pets': ['baby puss', 'dino'] } + * ]; + * + * _.where(characters, { 'age': 36 }); + * // => [{ 'name': 'barney', 'age': 36, 'pets': ['hoppy'] }] + * + * _.where(characters, { 'pets': ['dino'] }); + * // => [{ 'name': 'fred', 'age': 40, 'pets': ['baby puss', 'dino'] }] + */ + var where = filter; + + /*--------------------------------------------------------------------------*/ + + /** + * 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)); + } + + /** + * This method is like `_.find` except that it returns the index of the first + * element that passes the callback check, instead of the element itself. + * + * 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 {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 of the found element, else `-1`. + * @example + * + * var characters = [ + * { 'name': 'barney', 'age': 36, 'blocked': false }, + * { 'name': 'fred', 'age': 40, 'blocked': true }, + * { 'name': 'pebbles', 'age': 1, 'blocked': false } + * ]; + * + * _.findIndex(characters, function(chr) { + * return chr.age < 20; + * }); + * // => 2 + * + * // using "_.where" callback shorthand + * _.findIndex(characters, { 'age': 36 }); + * // => 0 + * + * // using "_.pluck" callback shorthand + * _.findIndex(characters, 'blocked'); + * // => 1 + */ + function findIndex(array, callback, thisArg) { + var index = -1, + length = array ? array.length : 0; + + callback = lodash.createCallback(callback, thisArg, 3); + while (++index < length) { + if (callback(array[index], index, array)) { + return index; + } + } + return -1; + } + + /** + * This method is like `_.findIndex` except that it iterates over elements + * of a `collection` from right to left. + * + * 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 {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 of the found element, else `-1`. + * @example + * + * var characters = [ + * { 'name': 'barney', 'age': 36, 'blocked': true }, + * { 'name': 'fred', 'age': 40, 'blocked': false }, + * { 'name': 'pebbles', 'age': 1, 'blocked': true } + * ]; + * + * _.findLastIndex(characters, function(chr) { + * return chr.age > 30; + * }); + * // => 1 + * + * // using "_.where" callback shorthand + * _.findLastIndex(characters, { 'age': 36 }); + * // => 0 + * + * // using "_.pluck" callback shorthand + * _.findLastIndex(characters, 'blocked'); + * // => 2 + */ + function findLastIndex(array, callback, thisArg) { + var length = array ? array.length : 0; + callback = lodash.createCallback(callback, thisArg, 3); + while (length--) { + if (callback(array[length], length, array)) { + return length; + } + } + return -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 = lodash.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, callback, thisArg) { + // juggle arguments + if (typeof isShallow != 'boolean' && isShallow != null) { + thisArg = callback; + callback = (typeof isShallow != 'function' && thisArg && thisArg[isShallow] === array) ? null : isShallow; + isShallow = false; + } + if (callback != null) { + array = map(array, callback, thisArg); + } + 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 = lodash.createCallback(callback, thisArg, 3); + while (index-- && callback(array[index], index, array)) { + n++; + } + } else { + n = (callback == null || thisArg) ? 1 : callback || n; + } + return slice(array, 0, nativeMin(nativeMax(0, length - n), length)); + } + + /** + * Creates an array of unique values present in all provided arrays using + * strict equality for comparisons, i.e. `===`. + * + * @static + * @memberOf _ + * @category Arrays + * @param {...Array} [array] The arrays to inspect. + * @returns {Array} Returns an array of shared values. + * @example + * + * _.intersection([1, 2, 3], [5, 2, 1, 4], [2, 1]); + * // => [1, 2] + */ + function intersection() { + var args = [], + argsIndex = -1, + argsLength = arguments.length, + caches = getArray(), + indexOf = getIndexOf(), + trustIndexOf = indexOf === baseIndexOf, + seen = getArray(); + + while (++argsIndex < argsLength) { + var value = arguments[argsIndex]; + if (isArray(value) || isArguments(value)) { + args.push(value); + caches.push(trustIndexOf && value.length >= largeArraySize && + createCache(argsIndex ? args[argsIndex] : seen)); + } + } + var array = args[0], + index = -1, + length = array ? array.length : 0, + result = []; + + outer: + while (++index < length) { + var cache = caches[0]; + value = array[index]; + + if ((cache ? cacheIndexOf(cache, value) : indexOf(seen, value)) < 0) { + argsIndex = argsLength; + (cache || seen).push(value); + while (--argsIndex) { + cache = caches[argsIndex]; + if ((cache ? cacheIndexOf(cache, value) : indexOf(args[argsIndex], value)) < 0) { + continue outer; + } + } + result.push(value); + } + } + while (argsLength--) { + cache = caches[argsLength]; + if (cache) { + releaseObject(cache); + } + } + releaseArray(caches); + releaseArray(seen); + 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 = lodash.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; + } + + /** + * Removes all provided values from the given array using strict equality for + * comparisons, i.e. `===`. + * + * @static + * @memberOf _ + * @category Arrays + * @param {Array} array The array to modify. + * @param {...*} [value] The values to remove. + * @returns {Array} Returns `array`. + * @example + * + * var array = [1, 2, 3, 1, 2, 3]; + * _.pull(array, 2, 3); + * console.log(array); + * // => [1, 1] + */ + function pull(array) { + var args = arguments, + argsIndex = 0, + argsLength = args.length, + length = array ? array.length : 0; + + while (++argsIndex < argsLength) { + var index = -1, + value = args[argsIndex]; + while (++index < length) { + if (array[index] === value) { + splice.call(array, index--, 1); + length--; + } + } + } + return array; + } + + /** + * 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 = typeof step == 'number' ? 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 || 1))), + result = Array(length); + + while (++index < length) { + result[index] = start; + start += step; + } + return result; + } + + /** + * Removes all elements from an array that the callback returns truey for + * and returns an array of removed elements. 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 modify. + * @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 removed elements. + * @example + * + * var array = [1, 2, 3, 4, 5, 6]; + * var evens = _.remove(array, function(num) { return num % 2 == 0; }); + * + * console.log(array); + * // => [1, 3, 5] + * + * console.log(evens); + * // => [2, 4, 6] + */ + function remove(array, callback, thisArg) { + var index = -1, + length = array ? array.length : 0, + result = []; + + callback = lodash.createCallback(callback, thisArg, 3); + while (++index < length) { + var value = array[index]; + if (callback(value, index, array)) { + result.push(value); + splice.call(array, index--, 1); + length--; + } + } + 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 = lodash.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 ? lodash.createCallback(callback, thisArg, 1) : identity; + value = callback(value); + + while (low < high) { + var mid = (low + high) >>> 1; + (callback(array[mid]) < value) + ? low = mid + 1 + : high = mid; + } + return low; + } + + /** + * Creates an array of unique values, in order, of the provided arrays using + * strict equality for comparisons, i.e. `===`. + * + * @static + * @memberOf _ + * @category Arrays + * @param {...Array} [array] The arrays to inspect. + * @returns {Array} Returns an array of combined values. + * @example + * + * _.union([1, 2, 3], [5, 2, 1, 4], [2, 1]); + * // => [1, 2, 3, 5, 4] + */ + function union() { + return baseUniq(baseFlatten(arguments, true, true)); + } + + /** + * Creates a duplicate-value-free version of an array using strict equality + * for comparisons, i.e. `===`. If the array is sorted, providing + * `true` for `isSorted` will use a faster algorithm. If a callback is provided + * each element of `array` is passed through the callback before uniqueness + * is computed. The callback is bound to `thisArg` and invoked with three + * arguments; (value, index, array). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @alias unique + * @category Arrays + * @param {Array} array The array to process. + * @param {boolean} [isSorted=false] A flag to indicate that `array` is sorted. + * @param {Function|Object|string} [callback=identity] The function called + * per iteration. If a property name or object is provided it will be used + * to create a "_.pluck" or "_.where" style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Array} Returns a duplicate-value-free array. + * @example + * + * _.uniq([1, 2, 1, 3, 1]); + * // => [1, 2, 3] + * + * _.uniq([1, 1, 2, 2, 3], true); + * // => [1, 2, 3] + * + * _.uniq(['A', 'b', 'C', 'a', 'B', 'c'], function(letter) { return letter.toLowerCase(); }); + * // => ['A', 'b', 'C'] + * + * _.uniq([1, 2.5, 3, 1.5, 2, 3.5], function(num) { return this.floor(num); }, Math); + * // => [1, 2.5, 3] + * + * // using "_.pluck" callback shorthand + * _.uniq([{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }], 'x'); + * // => [{ 'x': 1 }, { 'x': 2 }] + */ + function uniq(array, isSorted, callback, thisArg) { + // juggle arguments + if (typeof isSorted != 'boolean' && isSorted != null) { + thisArg = callback; + callback = (typeof isSorted != 'function' && thisArg && thisArg[isSorted] === array) ? null : isSorted; + isSorted = false; + } + if (callback != null) { + callback = lodash.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 that is the symmetric difference of the provided arrays. + * See http://en.wikipedia.org/wiki/Symmetric_difference. + * + * @static + * @memberOf _ + * @category Arrays + * @param {...Array} [array] The arrays to inspect. + * @returns {Array} Returns an array of values. + * @example + * + * _.xor([1, 2, 3], [5, 2, 1, 4]); + * // => [3, 5, 4] + * + * _.xor([1, 2, 5], [2, 3, 5], [3, 4, 5]); + * // => [1, 4, 5] + */ + function xor() { + var index = -1, + length = arguments.length; + + while (++index < length) { + var array = arguments[index]; + if (isArray(array) || isArguments(array)) { + var result = result + ? baseUniq(baseDifference(result, array).concat(baseDifference(array, result))) + : array; + } + } + return result || []; + } + + /** + * 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 array = arguments.length > 1 ? arguments : arguments[0], + index = -1, + length = array ? max(pluck(array, 'length')) : 0, + result = Array(length < 0 ? 0 : length); + + while (++index < length) { + result[index] = pluck(array, index); + } + return result; + } + + /** + * Creates an object composed from arrays of `keys` and `values`. Provide + * either a single two dimensional array, i.e. `[[key1, value1], [key2, value2]]` + * or two arrays, one of `keys` and one of corresponding `values`. + * + * @static + * @memberOf _ + * @alias object + * @category Arrays + * @param {Array} keys The array of keys. + * @param {Array} [values=[]] The array of values. + * @returns {Object} Returns an object composed of the given keys and + * corresponding values. + * @example + * + * _.zipObject(['fred', 'barney'], [30, 40]); + * // => { 'fred': 30, 'barney': 40 } + */ + function zipObject(keys, values) { + var index = -1, + length = keys ? keys.length : 0, + result = {}; + + if (!values && length && !isArray(keys[0])) { + values = []; + } + while (++index < length) { + var key = keys[index]; + if (values) { + result[key] = values[index]; + } else if (key) { + result[key[0]] = key[1]; + } + } + return result; + } + + /*--------------------------------------------------------------------------*/ + + /** + * Creates a function that executes `func`, with the `this` binding and + * arguments of the created function, only after being called `n` times. + * + * @static + * @memberOf _ + * @category Functions + * @param {number} n The number of times the function must be called before + * `func` is executed. + * @param {Function} func The function to restrict. + * @returns {Function} Returns the new restricted function. + * @example + * + * var saves = ['profile', 'settings']; + * + * var done = _.after(saves.length, function() { + * console.log('Done saving!'); + * }); + * + * _.forEach(saves, function(type) { + * asyncSave({ 'type': type, 'complete': done }); + * }); + * // => logs 'Done saving!', after all saves have completed + */ + function after(n, func) { + if (!isFunction(func)) { + throw new TypeError; + } + return function() { + if (--n < 1) { + return func.apply(this, arguments); + } + }; + } + + /** + * Creates a function that, when called, invokes `func` with the `this` + * binding of `thisArg` and prepends any additional `bind` arguments to those + * provided to the bound function. + * + * @static + * @memberOf _ + * @category Functions + * @param {Function} func The function to bind. + * @param {*} [thisArg] The `this` binding of `func`. + * @param {...*} [arg] Arguments to be partially applied. + * @returns {Function} Returns the new bound function. + * @example + * + * var func = function(greeting) { + * return greeting + ' ' + this.name; + * }; + * + * func = _.bind(func, { 'name': 'fred' }, 'hi'); + * func(); + * // => 'hi fred' + */ + function bind(func, thisArg) { + return arguments.length > 2 + ? createWrapper(func, 17, slice(arguments, 2), null, thisArg) + : createWrapper(func, 1, null, null, thisArg); + } + + /** + * Binds methods of an object to the object itself, overwriting the existing + * method. Method names may be specified as individual arguments or as arrays + * of method names. If no method names are provided all the function properties + * of `object` will be bound. + * + * @static + * @memberOf _ + * @category Functions + * @param {Object} object The object to bind and assign the bound methods to. + * @param {...string} [methodName] The object method names to + * bind, specified as individual method names or arrays of method names. + * @returns {Object} Returns `object`. + * @example + * + * var view = { + * 'label': 'docs', + * 'onClick': function() { console.log('clicked ' + this.label); } + * }; + * + * _.bindAll(view); + * jQuery('#docs').on('click', view.onClick); + * // => logs 'clicked docs', when the button is clicked + */ + function bindAll(object) { + var funcs = arguments.length > 1 ? baseFlatten(arguments, true, false, 1) : functions(object), + index = -1, + length = funcs.length; + + while (++index < length) { + var key = funcs[index]; + object[key] = createWrapper(object[key], 1, null, null, object); + } + return object; + } + + /** + * Creates a function that, when called, invokes the method at `object[key]` + * and prepends any additional `bindKey` arguments to those provided to the bound + * function. This method differs from `_.bind` by allowing bound functions to + * reference methods that will be redefined or don't yet exist. + * See http://michaux.ca/articles/lazy-function-definition-pattern. + * + * @static + * @memberOf _ + * @category Functions + * @param {Object} object The object the method belongs to. + * @param {string} key The key of the method. + * @param {...*} [arg] Arguments to be partially applied. + * @returns {Function} Returns the new bound function. + * @example + * + * var object = { + * 'name': 'fred', + * 'greet': function(greeting) { + * return greeting + ' ' + this.name; + * } + * }; + * + * var func = _.bindKey(object, 'greet', 'hi'); + * func(); + * // => 'hi fred' + * + * object.greet = function(greeting) { + * return greeting + 'ya ' + this.name + '!'; + * }; + * + * func(); + * // => 'hiya fred!' + */ + function bindKey(object, key) { + return arguments.length > 2 + ? createWrapper(key, 19, slice(arguments, 2), null, object) + : createWrapper(key, 3, null, null, object); + } + + /** + * Creates a function that is the composition of the provided functions, + * where each function consumes the return value of the function that follows. + * For example, composing the functions `f()`, `g()`, and `h()` produces `f(g(h()))`. + * Each function is executed with the `this` binding of the composed function. + * + * @static + * @memberOf _ + * @category Functions + * @param {...Function} [func] Functions to compose. + * @returns {Function} Returns the new composed function. + * @example + * + * var realNameMap = { + * 'pebbles': 'penelope' + * }; + * + * var format = function(name) { + * name = realNameMap[name.toLowerCase()] || name; + * return name.charAt(0).toUpperCase() + name.slice(1).toLowerCase(); + * }; + * + * var greet = function(formatted) { + * return 'Hiya ' + formatted + '!'; + * }; + * + * var welcome = _.compose(greet, format); + * welcome('pebbles'); + * // => 'Hiya Penelope!' + */ + function compose() { + var funcs = arguments, + length = funcs.length; + + while (length--) { + if (!isFunction(funcs[length])) { + throw new TypeError; + } + } + return function() { + var args = arguments, + length = funcs.length; + + while (length--) { + args = [funcs[length].apply(this, args)]; + } + return args[0]; + }; + } + + /** + * Creates a function which accepts one or more arguments of `func` that when + * invoked either executes `func` returning its result, if all `func` arguments + * have been provided, or returns a function that accepts one or more of the + * remaining `func` arguments, and so on. The arity of `func` can be specified + * if `func.length` is not sufficient. + * + * @static + * @memberOf _ + * @category Functions + * @param {Function} func The function to curry. + * @param {number} [arity=func.length] The arity of `func`. + * @returns {Function} Returns the new curried function. + * @example + * + * var curried = _.curry(function(a, b, c) { + * console.log(a + b + c); + * }); + * + * curried(1)(2)(3); + * // => 6 + * + * curried(1, 2)(3); + * // => 6 + * + * curried(1, 2, 3); + * // => 6 + */ + function curry(func, arity) { + arity = typeof arity == 'number' ? arity : (+arity || func.length); + return createWrapper(func, 4, null, null, null, arity); + } + + /** + * Creates a function that will delay the execution of `func` until after + * `wait` milliseconds have elapsed since the last time it was invoked. + * Provide an options object to indicate that `func` should be invoked on + * the leading and/or trailing edge of the `wait` timeout. Subsequent calls + * to the debounced function will return the result of the last `func` call. + * + * Note: If `leading` and `trailing` options are `true` `func` will be called + * on the trailing edge of the timeout only if the the debounced function is + * invoked more than once during the `wait` timeout. + * + * @static + * @memberOf _ + * @category Functions + * @param {Function} func The function to debounce. + * @param {number} wait The number of milliseconds to delay. + * @param {Object} [options] The options object. + * @param {boolean} [options.leading=false] Specify execution on the leading edge of the timeout. + * @param {number} [options.maxWait] The maximum time `func` is allowed to be delayed before it's called. + * @param {boolean} [options.trailing=true] Specify execution on the trailing edge of the timeout. + * @returns {Function} Returns the new debounced function. + * @example + * + * // avoid costly calculations while the window size is in flux + * var lazyLayout = _.debounce(calculateLayout, 150); + * jQuery(window).on('resize', lazyLayout); + * + * // execute `sendMail` when the click event is fired, debouncing subsequent calls + * jQuery('#postbox').on('click', _.debounce(sendMail, 300, { + * 'leading': true, + * 'trailing': false + * }); + * + * // ensure `batchLog` is executed once after 1 second of debounced calls + * var source = new EventSource('/stream'); + * source.addEventListener('message', _.debounce(batchLog, 250, { + * 'maxWait': 1000 + * }, false); + */ + function debounce(func, wait, options) { + var args, + maxTimeoutId, + result, + stamp, + thisArg, + timeoutId, + trailingCall, + lastCalled = 0, + maxWait = false, + trailing = true; + + if (!isFunction(func)) { + throw new TypeError; + } + wait = nativeMax(0, wait) || 0; + if (options === true) { + var leading = true; + trailing = false; + } else if (isObject(options)) { + leading = options.leading; + maxWait = 'maxWait' in options && (nativeMax(wait, options.maxWait) || 0); + trailing = 'trailing' in options ? options.trailing : trailing; + } + var delayed = function() { + var remaining = wait - (now() - stamp); + if (remaining <= 0) { + if (maxTimeoutId) { + clearTimeout(maxTimeoutId); + } + var isCalled = trailingCall; + maxTimeoutId = timeoutId = trailingCall = undefined; + if (isCalled) { + lastCalled = now(); + result = func.apply(thisArg, args); + if (!timeoutId && !maxTimeoutId) { + args = thisArg = null; + } + } + } else { + timeoutId = setTimeout(delayed, remaining); + } + }; + + var maxDelayed = function() { + if (timeoutId) { + clearTimeout(timeoutId); + } + maxTimeoutId = timeoutId = trailingCall = undefined; + if (trailing || (maxWait !== wait)) { + lastCalled = now(); + result = func.apply(thisArg, args); + if (!timeoutId && !maxTimeoutId) { + args = thisArg = null; + } + } + }; + + return function() { + args = arguments; + stamp = now(); + thisArg = this; + trailingCall = trailing && (timeoutId || !leading); + + if (maxWait === false) { + var leadingCall = leading && !timeoutId; + } else { + if (!maxTimeoutId && !leading) { + lastCalled = stamp; + } + var remaining = maxWait - (stamp - lastCalled), + isCalled = remaining <= 0; + + if (isCalled) { + if (maxTimeoutId) { + maxTimeoutId = clearTimeout(maxTimeoutId); + } + lastCalled = stamp; + result = func.apply(thisArg, args); + } + else if (!maxTimeoutId) { + maxTimeoutId = setTimeout(maxDelayed, remaining); + } + } + if (isCalled && timeoutId) { + timeoutId = clearTimeout(timeoutId); + } + else if (!timeoutId && wait !== maxWait) { + timeoutId = setTimeout(delayed, wait); + } + if (leadingCall) { + isCalled = true; + result = func.apply(thisArg, args); + } + if (isCalled && !timeoutId && !maxTimeoutId) { + args = thisArg = null; + } + return result; + }; + } + + /** + * Defers executing the `func` function until the current call stack has cleared. + * Additional arguments will be provided to `func` when it is invoked. + * + * @static + * @memberOf _ + * @category Functions + * @param {Function} func The function to defer. + * @param {...*} [arg] Arguments to invoke the function with. + * @returns {number} Returns the timer id. + * @example + * + * _.defer(function(text) { console.log(text); }, 'deferred'); + * // logs 'deferred' after one or more milliseconds + */ + function defer(func) { + if (!isFunction(func)) { + throw new TypeError; + } + var args = slice(arguments, 1); + return setTimeout(function() { func.apply(undefined, args); }, 1); + } + + /** + * Executes the `func` function after `wait` milliseconds. Additional arguments + * will be provided to `func` when it is invoked. + * + * @static + * @memberOf _ + * @category Functions + * @param {Function} func The function to delay. + * @param {number} wait The number of milliseconds to delay execution. + * @param {...*} [arg] Arguments to invoke the function with. + * @returns {number} Returns the timer id. + * @example + * + * _.delay(function(text) { console.log(text); }, 1000, 'later'); + * // => logs 'later' after one second + */ + function delay(func, wait) { + if (!isFunction(func)) { + throw new TypeError; + } + var args = slice(arguments, 2); + return setTimeout(function() { func.apply(undefined, args); }, wait); + } + + /** + * Creates a function that memoizes the result of `func`. If `resolver` is + * provided it will be used to determine the cache key for storing the result + * based on the arguments provided to the memoized function. By default, the + * first argument provided to the memoized function is used as the cache key. + * The `func` is executed with the `this` binding of the memoized function. + * The result cache is exposed as the `cache` property on the memoized function. + * + * @static + * @memberOf _ + * @category Functions + * @param {Function} func The function to have its output memoized. + * @param {Function} [resolver] A function used to resolve the cache key. + * @returns {Function} Returns the new memoizing function. + * @example + * + * var fibonacci = _.memoize(function(n) { + * return n < 2 ? n : fibonacci(n - 1) + fibonacci(n - 2); + * }); + * + * fibonacci(9) + * // => 34 + * + * var data = { + * 'fred': { 'name': 'fred', 'age': 40 }, + * 'pebbles': { 'name': 'pebbles', 'age': 1 } + * }; + * + * // modifying the result cache + * var get = _.memoize(function(name) { return data[name]; }, _.identity); + * get('pebbles'); + * // => { 'name': 'pebbles', 'age': 1 } + * + * get.cache.pebbles.name = 'penelope'; + * get('pebbles'); + * // => { 'name': 'penelope', 'age': 1 } + */ + function memoize(func, resolver) { + if (!isFunction(func)) { + throw new TypeError; + } + var memoized = function() { + var cache = memoized.cache, + key = resolver ? resolver.apply(this, arguments) : keyPrefix + arguments[0]; + + return hasOwnProperty.call(cache, key) + ? cache[key] + : (cache[key] = func.apply(this, arguments)); + } + memoized.cache = {}; + return memoized; + } + + /** + * 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)); + } + + /** + * This method is like `_.partial` except that `partial` arguments are + * appended to those provided to the new function. + * + * @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 defaultsDeep = _.partialRight(_.merge, _.defaults); + * + * var options = { + * 'variable': 'data', + * 'imports': { 'jq': $ } + * }; + * + * defaultsDeep(options, _.templateSettings); + * + * options.variable + * // => 'data' + * + * options.imports + * // => { '_': _, 'jq': $ } + */ + function partialRight(func) { + return createWrapper(func, 32, null, slice(arguments, 1)); + } + + /** + * Creates a function that, when executed, will only call the `func` function + * at most once per every `wait` milliseconds. Provide an options object to + * indicate that `func` should be invoked on the leading and/or trailing edge + * of the `wait` timeout. Subsequent calls to the throttled function will + * return the result of the last `func` call. + * + * Note: If `leading` and `trailing` options are `true` `func` will be called + * on the trailing edge of the timeout only if the the throttled function is + * invoked more than once during the `wait` timeout. + * + * @static + * @memberOf _ + * @category Functions + * @param {Function} func The function to throttle. + * @param {number} wait The number of milliseconds to throttle executions to. + * @param {Object} [options] The options object. + * @param {boolean} [options.leading=true] Specify execution on the leading edge of the timeout. + * @param {boolean} [options.trailing=true] Specify execution on the trailing edge of the timeout. + * @returns {Function} Returns the new throttled function. + * @example + * + * // avoid excessively updating the position while scrolling + * var throttled = _.throttle(updatePosition, 100); + * jQuery(window).on('scroll', throttled); + * + * // execute `renewToken` when the click event is fired, but not more than once every 5 minutes + * jQuery('.interactive').on('click', _.throttle(renewToken, 300000, { + * 'trailing': false + * })); + */ + function throttle(func, wait, options) { + var leading = true, + trailing = true; + + if (!isFunction(func)) { + throw new TypeError; + } + if (options === false) { + leading = false; + } else if (isObject(options)) { + leading = 'leading' in options ? options.leading : leading; + trailing = 'trailing' in options ? options.trailing : trailing; + } + debounceOptions.leading = leading; + debounceOptions.maxWait = wait; + debounceOptions.trailing = trailing; + + return debounce(func, wait, debounceOptions); + } + + /** + * 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 '<p>' + func(text) + '</p>'; + * }); + * + * p('Fred, Wilma, & Pebbles'); + * // => '<p>Fred, Wilma, & Pebbles</p>' + */ + function wrap(value, wrapper) { + return createWrapper(wrapper, 16, [value]); + } + + /*--------------------------------------------------------------------------*/ + + /** + * Creates a function that returns `value`. + * + * @static + * @memberOf _ + * @category Utilities + * @param {*} value The value to return from the new function. + * @returns {Function} Returns the new function. + * @example + * + * var object = { 'name': 'fred' }; + * var getter = _.constant(object); + * getter() === object; + * // => true + */ + function constant(value) { + return function() { + return value; + }; + } + + /** + * Produces a callback bound to an optional `thisArg`. If `func` is a property + * name the created callback will return the property value for a given element. + * If `func` is an object the created callback will return `true` for elements + * that contain the equivalent object properties, otherwise it will return `false`. + * + * @static + * @memberOf _ + * @category Utilities + * @param {*} [func=identity] The value to convert to a callback. + * @param {*} [thisArg] The `this` binding of the created callback. + * @param {number} [argCount] The number of arguments the callback accepts. + * @returns {Function} Returns a callback function. + * @example + * + * var characters = [ + * { 'name': 'barney', 'age': 36 }, + * { 'name': 'fred', 'age': 40 } + * ]; + * + * // wrap to create custom callback shorthands + * _.createCallback = _.wrap(_.createCallback, function(func, callback, thisArg) { + * var match = /^(.+?)__([gl]t)(.+)$/.exec(callback); + * return !match ? func(callback, thisArg) : function(object) { + * return match[2] == 'gt' ? object[match[1]] > match[3] : object[match[1]] < match[3]; + * }; + * }); + * + * _.filter(characters, 'age__gt38'); + * // => [{ 'name': 'fred', 'age': 40 }] + */ + function createCallback(func, thisArg, argCount) { + var type = typeof func; + if (func == null || type == 'function') { + return baseCreateCallback(func, thisArg, argCount); + } + // handle "_.pluck" style callback shorthands + if (type != 'object') { + return property(func); + } + var props = keys(func), + key = props[0], + a = func[key]; + + // handle "_.where" style callback shorthands + if (props.length == 1 && a === a && !isObject(a)) { + // fast path the common case of providing an object with a single + // property containing a primitive value + return function(object) { + var b = object[key]; + return a === b && (a !== 0 || (1 / a == 1 / b)); + }; + } + return function(object) { + var length = props.length, + result = false; + + while (length--) { + if (!(result = baseIsEqual(object[props[length]], func[props[length]], null, true))) { + break; + } + } + return result; + }; + } + + /** + * Converts the characters `&`, `<`, `>`, `"`, and `'` in `string` to their + * corresponding HTML entities. + * + * @static + * @memberOf _ + * @category Utilities + * @param {string} string The string to escape. + * @returns {string} Returns the escaped string. + * @example + * + * _.escape('Fred, Wilma, & Pebbles'); + * // => 'Fred, Wilma, & Pebbles' + */ + function escape(string) { + return string == null ? '' : String(string).replace(reUnescapedHtml, escapeHtmlChar); + } + + /** + * This method returns the first argument provided to it. + * + * @static + * @memberOf _ + * @category Utilities + * @param {*} value Any value. + * @returns {*} Returns `value`. + * @example + * + * var object = { 'name': 'fred' }; + * _.identity(object) === object; + * // => true + */ + function identity(value) { + return value; + } + + /** + * Adds function properties of a source object to the destination object. + * If `object` is a function methods will be added to its prototype as well. + * + * @static + * @memberOf _ + * @category Utilities + * @param {Function|Object} [object=lodash] object The destination object. + * @param {Object} source The object of functions to add. + * @param {Object} [options] The options object. + * @param {boolean} [options.chain=true] Specify whether the functions added are chainable. + * @example + * + * function capitalize(string) { + * return string.charAt(0).toUpperCase() + string.slice(1).toLowerCase(); + * } + * + * _.mixin({ 'capitalize': capitalize }); + * _.capitalize('fred'); + * // => 'Fred' + * + * _('fred').capitalize().value(); + * // => 'Fred' + * + * _.mixin({ 'capitalize': capitalize }, { 'chain': false }); + * _('fred').capitalize(); + * // => 'Fred' + */ + function mixin(object, source, options) { + var chain = true, + methodNames = source && functions(source); + + if (!source || (!options && !methodNames.length)) { + if (options == null) { + options = source; + } + ctor = lodashWrapper; + source = object; + object = lodash; + methodNames = functions(source); + } + if (options === false) { + chain = false; + } else if (isObject(options) && 'chain' in options) { + chain = options.chain; + } + var ctor = object, + isFunc = isFunction(ctor); + + forEach(methodNames, function(methodName) { + var func = object[methodName] = source[methodName]; + if (isFunc) { + ctor.prototype[methodName] = function() { + var chainAll = this.__chain__, + value = this.__wrapped__, + args = [value]; + + push.apply(args, arguments); + var result = func.apply(object, args); + if (chain || chainAll) { + if (value === result && isObject(result)) { + return this; + } + result = new ctor(result); + result.__chain__ = chainAll; + } + return result; + }; + } + }); + } + + /** + * Reverts the '_' variable to its previous value and returns a reference to + * the `lodash` function. + * + * @static + * @memberOf _ + * @category Utilities + * @returns {Function} Returns the `lodash` function. + * @example + * + * var lodash = _.noConflict(); + */ + function noConflict() { + context._ = oldDash; + return this; + } + + /** + * A no-operation function. + * + * @static + * @memberOf _ + * @category Utilities + * @example + * + * var object = { 'name': 'fred' }; + * _.noop(object) === undefined; + * // => true + */ + function noop() { + // no operation performed + } + + /** + * Gets the number of milliseconds that have elapsed since the Unix epoch + * (1 January 1970 00:00:00 UTC). + * + * @static + * @memberOf _ + * @category Utilities + * @example + * + * var stamp = _.now(); + * _.defer(function() { console.log(_.now() - stamp); }); + * // => logs the number of milliseconds it took for the deferred function to be called + */ + var now = isNative(now = Date.now) && now || function() { + return new Date().getTime(); + }; + + /** + * Converts the given value into an integer of the specified radix. + * If `radix` is `undefined` or `0` a `radix` of `10` is used unless the + * `value` is a hexadecimal, in which case a `radix` of `16` is used. + * + * Note: This method avoids differences in native ES3 and ES5 `parseInt` + * implementations. See http://es5.github.io/#E. + * + * @static + * @memberOf _ + * @category Utilities + * @param {string} value The value to parse. + * @param {number} [radix] The radix used to interpret the value to parse. + * @returns {number} Returns the new integer value. + * @example + * + * _.parseInt('08'); + * // => 8 + */ + var parseInt = nativeParseInt(whitespace + '08') == 8 ? nativeParseInt : function(value, radix) { + // Firefox < 21 and Opera < 15 follow the ES3 specified implementation of `parseInt` + return nativeParseInt(isString(value) ? value.replace(reLeadingSpacesAndZeros, '') : value, radix || 0); + }; + + /** + * Creates a "_.pluck" style function, which returns the `key` value of a + * given object. + * + * @static + * @memberOf _ + * @category Utilities + * @param {string} key The name of the property to retrieve. + * @returns {Function} Returns the new function. + * @example + * + * var characters = [ + * { 'name': 'fred', 'age': 40 }, + * { 'name': 'barney', 'age': 36 } + * ]; + * + * var getName = _.property('name'); + * + * _.map(characters, getName); + * // => ['barney', 'fred'] + * + * _.sortBy(characters, getName); + * // => [{ 'name': 'barney', 'age': 36 }, { 'name': 'fred', 'age': 40 }] + */ + function property(key) { + return function(object) { + return object[key]; + }; + } + + /** + * Produces a random number between `min` and `max` (inclusive). If only one + * argument is provided a number between `0` and the given number will be + * returned. If `floating` is truey or either `min` or `max` are floats a + * floating-point number will be returned instead of an integer. + * + * @static + * @memberOf _ + * @category Utilities + * @param {number} [min=0] The minimum possible value. + * @param {number} [max=1] The maximum possible value. + * @param {boolean} [floating=false] Specify returning a floating-point number. + * @returns {number} Returns a random number. + * @example + * + * _.random(0, 5); + * // => an integer between 0 and 5 + * + * _.random(5); + * // => also an integer between 0 and 5 + * + * _.random(5, true); + * // => a floating-point number between 0 and 5 + * + * _.random(1.2, 5.2); + * // => a floating-point number between 1.2 and 5.2 + */ + function random(min, max, floating) { + var noMin = min == null, + noMax = max == null; + + if (floating == null) { + if (typeof min == 'boolean' && noMax) { + floating = min; + min = 1; + } + else if (!noMax && typeof max == 'boolean') { + floating = max; + noMax = true; + } + } + if (noMin && noMax) { + max = 1; + } + min = +min || 0; + if (noMax) { + max = min; + min = 0; + } else { + max = +max || 0; + } + if (floating || min % 1 || max % 1) { + var rand = nativeRandom(); + return nativeMin(min + (rand * (max - min + parseFloat('1e-' + ((rand +'').length - 1)))), max); + } + return baseRandom(min, max); + } + + /** + * Resolves the value of property `key` on `object`. If `key` is a function + * it will be invoked with the `this` binding of `object` and its result returned, + * else the property value is returned. If `object` is falsey then `undefined` + * is returned. + * + * @static + * @memberOf _ + * @category Utilities + * @param {Object} object The object to inspect. + * @param {string} key The name of the property to resolve. + * @returns {*} Returns the resolved value. + * @example + * + * var object = { + * 'cheese': 'crumpets', + * 'stuff': function() { + * return 'nonsense'; + * } + * }; + * + * _.result(object, 'cheese'); + * // => 'crumpets' + * + * _.result(object, 'stuff'); + * // => 'nonsense' + */ + function result(object, key) { + if (object) { + var value = object[key]; + return isFunction(value) ? object[key]() : value; + } + } + + /** + * A micro-templating method that handles arbitrary delimiters, preserves + * whitespace, and correctly escapes quotes within interpolated code. + * + * Note: In the development build, `_.template` utilizes sourceURLs for easier + * debugging. See http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl + * + * For more information on precompiling templates see: + * http://lodash.com/custom-builds + * + * For more information on Chrome extension sandboxes see: + * http://developer.chrome.com/stable/extensions/sandboxingEval.html + * + * @static + * @memberOf _ + * @category Utilities + * @param {string} text The template text. + * @param {Object} data The data object used to populate the text. + * @param {Object} [options] The options object. + * @param {RegExp} [options.escape] The "escape" delimiter. + * @param {RegExp} [options.evaluate] The "evaluate" delimiter. + * @param {Object} [options.imports] An object to import into the template as local variables. + * @param {RegExp} [options.interpolate] The "interpolate" delimiter. + * @param {string} [sourceURL] The sourceURL of the template's compiled source. + * @param {string} [variable] The data object variable name. + * @returns {Function|string} Returns a compiled function when no `data` object + * is given, else it returns the interpolated text. + * @example + * + * // using the "interpolate" delimiter to create a compiled template + * var compiled = _.template('hello <%= name %>'); + * compiled({ 'name': 'fred' }); + * // => 'hello fred' + * + * // using the "escape" delimiter to escape HTML in data property values + * _.template('<b><%- value %></b>', { 'value': '<script>' }); + * // => '<b><script></b>' + * + * // using the "evaluate" delimiter to generate HTML + * var list = '<% _.forEach(people, function(name) { %><li><%- name %></li><% }); %>'; + * _.template(list, { 'people': ['fred', 'barney'] }); + * // => '<li>fred</li><li>barney</li>' + * + * // using the ES6 delimiter as an alternative to the default "interpolate" delimiter + * _.template('hello ${ name }', { 'name': 'pebbles' }); + * // => 'hello pebbles' + * + * // using the internal `print` function in "evaluate" delimiters + * _.template('<% print("hello " + name); %>!', { 'name': 'barney' }); + * // => 'hello barney!' + * + * // using a custom template delimiters + * _.templateSettings = { + * 'interpolate': /{{([\s\S]+?)}}/g + * }; + * + * _.template('hello {{ name }}!', { 'name': 'mustache' }); + * // => 'hello mustache!' + * + * // using the `imports` option to import jQuery + * var list = '<% jq.each(people, function(name) { %><li><%- name %></li><% }); %>'; + * _.template(list, { 'people': ['fred', 'barney'] }, { 'imports': { 'jq': jQuery } }); + * // => '<li>fred</li><li>barney</li>' + * + * // using the `sourceURL` option to specify a custom sourceURL for the template + * var compiled = _.template('hello <%= name %>', null, { 'sourceURL': '/basic/greeting.jst' }); + * compiled(data); + * // => find the source of "greeting.jst" under the Sources tab or Resources panel of the web inspector + * + * // using the `variable` option to ensure a with-statement isn't used in the compiled template + * var compiled = _.template('hi <%= data.name %>!', null, { 'variable': 'data' }); + * compiled.source; + * // => function(data) { + * var __t, __p = '', __e = _.escape; + * __p += 'hi ' + ((__t = ( data.name )) == null ? '' : __t) + '!'; + * return __p; + * } + * + * // using the `source` property to inline compiled templates for meaningful + * // line numbers in error messages and a stack trace + * fs.writeFileSync(path.join(cwd, 'jst.js'), '\ + * var JST = {\ + * "main": ' + _.template(mainText).source + '\ + * };\ + * '); + */ + function template(text, data, options) { + // based on John Resig's `tmpl` implementation + // http://ejohn.org/blog/javascript-micro-templating/ + // and Laura Doktorova's doT.js + // https://github.com/olado/doT + var settings = lodash.templateSettings; + text = String(text || ''); + + // avoid missing dependencies when `iteratorTemplate` is not defined + options = defaults({}, options, settings); + + var imports = defaults({}, options.imports, settings.imports), + importsKeys = keys(imports), + importsValues = values(imports); + + var isEvaluating, + index = 0, + interpolate = options.interpolate || reNoMatch, + source = "__p += '"; + + // compile the regexp to match each delimiter + var reDelimiters = RegExp( + (options.escape || reNoMatch).source + '|' + + interpolate.source + '|' + + (interpolate === reInterpolate ? reEsTemplate : reNoMatch).source + '|' + + (options.evaluate || reNoMatch).source + '|$' + , 'g'); + + text.replace(reDelimiters, function(match, escapeValue, interpolateValue, esTemplateValue, evaluateValue, offset) { + interpolateValue || (interpolateValue = esTemplateValue); + + // escape characters that cannot be included in string literals + source += text.slice(index, offset).replace(reUnescapedString, escapeStringChar); + + // replace delimiters with snippets + if (escapeValue) { + source += "' +\n__e(" + escapeValue + ") +\n'"; + } + if (evaluateValue) { + isEvaluating = true; + source += "';\n" + evaluateValue + ";\n__p += '"; + } + if (interpolateValue) { + source += "' +\n((__t = (" + interpolateValue + ")) == null ? '' : __t) +\n'"; + } + index = offset + match.length; + + // the JS engine embedded in Adobe products requires returning the `match` + // string in order to produce the correct `offset` value + return match; + }); + + source += "';\n"; + + // if `variable` is not specified, wrap a with-statement around the generated + // code to add the data object to the top of the scope chain + var variable = options.variable, + hasVariable = variable; + + if (!hasVariable) { + variable = 'obj'; + source = 'with (' + variable + ') {\n' + source + '\n}\n'; + } + // cleanup code by stripping empty strings + source = (isEvaluating ? source.replace(reEmptyStringLeading, '') : source) + .replace(reEmptyStringMiddle, '$1') + .replace(reEmptyStringTrailing, '$1;'); + + // frame code as the function body + source = 'function(' + variable + ') {\n' + + (hasVariable ? '' : variable + ' || (' + variable + ' = {});\n') + + "var __t, __p = '', __e = _.escape" + + (isEvaluating + ? ', __j = Array.prototype.join;\n' + + "function print() { __p += __j.call(arguments, '') }\n" + : ';\n' + ) + + source + + 'return __p\n}'; + + // Use a sourceURL for easier debugging. + // http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl + var sourceURL = '\n/*\n//# sourceURL=' + (options.sourceURL || '/lodash/template/source[' + (templateCounter++) + ']') + '\n*/'; + + try { + var result = Function(importsKeys, 'return ' + source + sourceURL).apply(undefined, importsValues); + } catch(e) { + e.source = source; + throw e; + } + if (data) { + return result(data); + } + // provide the compiled function's source by its `toString` method, in + // supported environments, or the `source` property as a convenience for + // inlining compiled templates during the build process + result.source = source; + return result; + } + + /** + * Executes the callback `n` times, returning an array of the results + * of each callback execution. The callback is bound to `thisArg` and invoked + * with one argument; (index). + * + * @static + * @memberOf _ + * @category Utilities + * @param {number} n The number of times to execute the callback. + * @param {Function} callback The function called per iteration. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Array} Returns an array of the results of each `callback` execution. + * @example + * + * var diceRolls = _.times(3, _.partial(_.random, 1, 6)); + * // => [3, 6, 4] + * + * _.times(3, function(n) { mage.castSpell(n); }); + * // => calls `mage.castSpell(n)` three times, passing `n` of `0`, `1`, and `2` respectively + * + * _.times(3, function(n) { this.cast(n); }, mage); + * // => also calls `mage.castSpell(n)` three times + */ + function times(n, callback, thisArg) { + n = (n = +n) > -1 ? n : 0; + var index = -1, + result = Array(n); + + callback = baseCreateCallback(callback, thisArg, 1); + while (++index < n) { + result[index] = callback(index); + } + return result; + } + + /** + * The inverse of `_.escape` this method converts the HTML entities + * `&`, `<`, `>`, `"`, and `'` in `string` to their + * corresponding characters. + * + * @static + * @memberOf _ + * @category Utilities + * @param {string} string The string to unescape. + * @returns {string} Returns the unescaped string. + * @example + * + * _.unescape('Fred, Barney & Pebbles'); + * // => 'Fred, Barney & Pebbles' + */ + function unescape(string) { + return string == null ? '' : String(string).replace(reEscapedHtml, unescapeHtmlChar); + } + + /** + * Generates a unique ID. If `prefix` is provided the ID will be appended to it. + * + * @static + * @memberOf _ + * @category Utilities + * @param {string} [prefix] The value to prefix the ID with. + * @returns {string} Returns the unique ID. + * @example + * + * _.uniqueId('contact_'); + * // => 'contact_104' + * + * _.uniqueId(); + * // => '105' + */ + function uniqueId(prefix) { + var id = ++idCounter; + return String(prefix == null ? '' : prefix) + id; + } + + /*--------------------------------------------------------------------------*/ + + /** + * Creates a `lodash` object that wraps the given value with explicit + * method chaining enabled. + * + * @static + * @memberOf _ + * @category Chaining + * @param {*} value The value to wrap. + * @returns {Object} Returns the wrapper object. + * @example + * + * var characters = [ + * { 'name': 'barney', 'age': 36 }, + * { 'name': 'fred', 'age': 40 }, + * { 'name': 'pebbles', 'age': 1 } + * ]; + * + * var youngest = _.chain(characters) + * .sortBy('age') + * .map(function(chr) { return chr.name + ' is ' + chr.age; }) + * .first() + * .value(); + * // => 'pebbles is 1' + */ + function chain(value) { + value = new lodashWrapper(value); + value.__chain__ = true; + return value; + } + + /** + * Invokes `interceptor` with the `value` as the first argument and then + * returns `value`. The purpose of this method is to "tap into" a method + * chain in order to perform operations on intermediate results within + * the chain. + * + * @static + * @memberOf _ + * @category Chaining + * @param {*} value The value to provide to `interceptor`. + * @param {Function} interceptor The function to invoke. + * @returns {*} Returns `value`. + * @example + * + * _([1, 2, 3, 4]) + * .tap(function(array) { array.pop(); }) + * .reverse() + * .value(); + * // => [3, 2, 1] + */ + function tap(value, interceptor) { + interceptor(value); + return value; + } + + /** + * Enables explicit method chaining on the wrapper object. + * + * @name chain + * @memberOf _ + * @category Chaining + * @returns {*} Returns the wrapper object. + * @example + * + * var characters = [ + * { 'name': 'barney', 'age': 36 }, + * { 'name': 'fred', 'age': 40 } + * ]; + * + * // without explicit chaining + * _(characters).first(); + * // => { 'name': 'barney', 'age': 36 } + * + * // with explicit chaining + * _(characters).chain() + * .first() + * .pick('age') + * .value(); + * // => { 'age': 36 } + */ + function wrapperChain() { + this.__chain__ = true; + return this; + } + + /** + * Produces the `toString` result of the wrapped value. + * + * @name toString + * @memberOf _ + * @category Chaining + * @returns {string} Returns the string result. + * @example + * + * _([1, 2, 3]).toString(); + * // => '1,2,3' + */ + function wrapperToString() { + return String(this.__wrapped__); + } + + /** + * Extracts the wrapped value. + * + * @name valueOf + * @memberOf _ + * @alias value + * @category Chaining + * @returns {*} Returns the wrapped value. + * @example + * + * _([1, 2, 3]).valueOf(); + * // => [1, 2, 3] + */ + function wrapperValueOf() { + return this.__wrapped__; + } + + /*--------------------------------------------------------------------------*/ + + // add functions that return wrapped values when chaining + lodash.after = after; + lodash.assign = assign; + lodash.at = at; + lodash.bind = bind; + lodash.bindAll = bindAll; + lodash.bindKey = bindKey; + lodash.chain = chain; + lodash.compact = compact; + lodash.compose = compose; + lodash.constant = constant; + lodash.countBy = countBy; + lodash.create = create; + lodash.createCallback = createCallback; + lodash.curry = curry; + lodash.debounce = debounce; + lodash.defaults = defaults; + lodash.defer = defer; + lodash.delay = delay; + lodash.difference = difference; + lodash.filter = filter; + lodash.flatten = flatten; + lodash.forEach = forEach; + lodash.forEachRight = forEachRight; + lodash.forIn = forIn; + lodash.forInRight = forInRight; + lodash.forOwn = forOwn; + lodash.forOwnRight = forOwnRight; + lodash.functions = functions; + lodash.groupBy = groupBy; + lodash.indexBy = indexBy; + lodash.initial = initial; + lodash.intersection = intersection; + lodash.invert = invert; + lodash.invoke = invoke; + lodash.keys = keys; + lodash.map = map; + lodash.mapValues = mapValues; + lodash.max = max; + lodash.memoize = memoize; + lodash.merge = merge; + lodash.min = min; + lodash.omit = omit; + lodash.once = once; + lodash.pairs = pairs; + lodash.partial = partial; + lodash.partialRight = partialRight; + lodash.pick = pick; + lodash.pluck = pluck; + lodash.property = property; + lodash.pull = pull; + lodash.range = range; + lodash.reject = reject; + lodash.remove = remove; + lodash.rest = rest; + lodash.shuffle = shuffle; + lodash.sortBy = sortBy; + lodash.tap = tap; + lodash.throttle = throttle; + lodash.times = times; + lodash.toArray = toArray; + lodash.transform = transform; + lodash.union = union; + lodash.uniq = uniq; + lodash.values = values; + lodash.where = where; + lodash.without = without; + lodash.wrap = wrap; + lodash.xor = xor; + lodash.zip = zip; + lodash.zipObject = zipObject; + + // add aliases + lodash.collect = map; + lodash.drop = rest; + lodash.each = forEach; + lodash.eachRight = forEachRight; + lodash.extend = assign; + lodash.methods = functions; + lodash.object = zipObject; + lodash.select = filter; + lodash.tail = rest; + lodash.unique = uniq; + lodash.unzip = zip; + + // add functions to `lodash.prototype` + mixin(lodash); + + /*--------------------------------------------------------------------------*/ + + // add functions that return unwrapped values when chaining + lodash.clone = clone; + lodash.cloneDeep = cloneDeep; + lodash.contains = contains; + lodash.escape = escape; + lodash.every = every; + lodash.find = find; + lodash.findIndex = findIndex; + lodash.findKey = findKey; + lodash.findLast = findLast; + lodash.findLastIndex = findLastIndex; + lodash.findLastKey = findLastKey; + lodash.has = has; + lodash.identity = identity; + lodash.indexOf = indexOf; + lodash.isArguments = isArguments; + lodash.isArray = isArray; + lodash.isBoolean = isBoolean; + lodash.isDate = isDate; + lodash.isElement = isElement; + lodash.isEmpty = isEmpty; + lodash.isEqual = isEqual; + lodash.isFinite = isFinite; + lodash.isFunction = isFunction; + lodash.isNaN = isNaN; + lodash.isNull = isNull; + lodash.isNumber = isNumber; + lodash.isObject = isObject; + lodash.isPlainObject = isPlainObject; + lodash.isRegExp = isRegExp; + lodash.isString = isString; + lodash.isUndefined = isUndefined; + lodash.lastIndexOf = lastIndexOf; + lodash.mixin = mixin; + lodash.noConflict = noConflict; + lodash.noop = noop; + lodash.now = now; + lodash.parseInt = parseInt; + lodash.random = random; + lodash.reduce = reduce; + lodash.reduceRight = reduceRight; + lodash.result = result; + lodash.runInContext = runInContext; + lodash.size = size; + lodash.some = some; + lodash.sortedIndex = sortedIndex; + lodash.template = template; + lodash.unescape = unescape; + lodash.uniqueId = uniqueId; + + // add aliases + lodash.all = every; + lodash.any = some; + lodash.detect = find; + lodash.findWhere = find; + lodash.foldl = reduce; + lodash.foldr = reduceRight; + lodash.include = contains; + lodash.inject = reduce; + + mixin(function() { + var source = {} + forOwn(lodash, function(func, methodName) { + if (!lodash.prototype[methodName]) { + source[methodName] = func; + } + }); + return source; + }(), false); + + /*--------------------------------------------------------------------------*/ + + // add functions capable of returning wrapped and unwrapped values when chaining + lodash.first = first; + lodash.last = last; + lodash.sample = sample; + + // add aliases + lodash.take = first; + lodash.head = first; + + forOwn(lodash, function(func, methodName) { + var callbackable = methodName !== 'sample'; + if (!lodash.prototype[methodName]) { + lodash.prototype[methodName]= function(n, guard) { + var chainAll = this.__chain__, + result = func(this.__wrapped__, n, guard); + + return !chainAll && (n == null || (guard && !(callbackable && typeof n == 'function'))) + ? result + : new lodashWrapper(result, chainAll); + }; + } + }); + + /*--------------------------------------------------------------------------*/ + + /** + * The semantic version number. + * + * @static + * @memberOf _ + * @type string + */ + lodash.VERSION = '2.4.1'; + + // add "Chaining" functions to the wrapper + lodash.prototype.chain = wrapperChain; + lodash.prototype.toString = wrapperToString; + lodash.prototype.value = wrapperValueOf; + lodash.prototype.valueOf = wrapperValueOf; + + // add `Array` functions that return unwrapped values + forEach(['join', 'pop', 'shift'], function(methodName) { + var func = arrayRef[methodName]; + lodash.prototype[methodName] = function() { + var chainAll = this.__chain__, + result = func.apply(this.__wrapped__, arguments); + + return chainAll + ? new lodashWrapper(result, chainAll) + : result; + }; + }); + + // add `Array` functions that return the existing wrapped value + forEach(['push', 'reverse', 'sort', 'unshift'], function(methodName) { + var func = arrayRef[methodName]; + lodash.prototype[methodName] = function() { + func.apply(this.__wrapped__, arguments); + return this; + }; + }); + + // add `Array` functions that return new wrapped values + forEach(['concat', 'slice', 'splice'], function(methodName) { + var func = arrayRef[methodName]; + lodash.prototype[methodName] = function() { + return new lodashWrapper(func.apply(this.__wrapped__, arguments), this.__chain__); + }; + }); + + return lodash; + } + + /*--------------------------------------------------------------------------*/ + + // expose Lo-Dash + var _ = runInContext(); + + // some AMD build optimizers like r.js check for condition patterns like the following: + if (typeof define == 'function' && typeof define.amd == 'object' && define.amd) { + // Expose Lo-Dash to the global object even when an AMD loader is present in + // case Lo-Dash is loaded with a RequireJS shim config. + // See http://requirejs.org/docs/api.html#config-shim + root._ = _; + + // define as an anonymous module so, through path mapping, it can be + // referenced as the "underscore" module + define(function() { + return _; + }); + } + // check for `exports` after `define` in case a build optimizer adds an `exports` object + else if (freeExports && freeModule) { + // in Node.js or RingoJS + if (moduleExports) { + (freeModule.exports = _)._ = _; + } + // in Narwhal or Rhino -require + else { + freeExports._ = _; + } + } + else { + // in a browser or Rhino + root._ = _; + } +}.call(this)); |