diff --git a/app/assets/javascripts/discourse/lib/emoji/emoji-toolbar.js.es6 b/app/assets/javascripts/discourse/lib/emoji/emoji-toolbar.js.es6 index f40b5ed51..be0cbad2b 100644 --- a/app/assets/javascripts/discourse/lib/emoji/emoji-toolbar.js.es6 +++ b/app/assets/javascripts/discourse/lib/emoji/emoji-toolbar.js.es6 @@ -40,34 +40,73 @@ var closeSelector = function(){ $('body, textarea').off('keydown.emoji'); }; -var ungroupedIcons; +var ungroupedIcons, recentlyUsedIcons; + +var initializeUngroupedIcons = function(){ + ungroupedIcons = []; + + var groupedIcons = {}; + _.each(groups, function(group){ + _.each(group.icons, function(icon){ + groupedIcons[icon] = true; + }); + }); + + var emojis = Discourse.Emoji.list(); + _.each(emojis, function(emoji){ + if(groupedIcons[emoji] !== true){ + ungroupedIcons.push(emoji); + } + }); + + if(ungroupedIcons.length > 0){ + groups.push({name: 'ungrouped', icons: ungroupedIcons}); + } +}; + +if (!localStorage.emojiUsage) { localStorage.emojiUsage = "{}"; } + +var trackEmojiUsage = function(title){ + var recent = JSON.parse(localStorage.emojiUsage); + + if (!recent[title]) { recent[title] = { title: title, usage: 0 }; } + recent[title]["usage"]++; + + localStorage.emojiUsage = JSON.stringify(recent); + + // clear the cache + recentlyUsedIcons = null; +}; + +var initializeRecentlyUsedIcons = function() { + recentlyUsedIcons = []; + + var usage = JSON.parse(localStorage.emojiUsage); + var recent = _.take(_.sortByAll(usage, ["usage", "title"]).reverse(), PER_ROW); + + + if(recentlyUsedIcons.length > 0){ + _.each(recent, function(emoji){ + recentlyUsedIcons.push(emoji.title); + }); + + var recentGroup = _.find(groups, {name: 'recent'}); + if(!recentGroup){ + recentGroup = {name: 'recent', icons: []}; + groups.push(recentGroup); + } + + recentGroup.icons = recentlyUsedIcons; + } +}; var toolbar = function(selected){ - if(!ungroupedIcons){ - ungroupedIcons = []; - var groupedIcons = {}; - - _.each(groups, function(group){ - _.each(group.icons, function(icon){ - groupedIcons[icon] = true; - }); - }); - - var emojis = Discourse.Emoji.list(); - _.each(emojis,function(emoji){ - if(groupedIcons[emoji] !== true){ - ungroupedIcons.push(emoji); - } - }); - - if(ungroupedIcons.length > 0){ - groups.push({name: 'ungrouped', icons: ungroupedIcons}); - } - } + if (!ungroupedIcons) { initializeUngroupedIcons(); } + if (!recentlyUsedIcons) { initializeRecentlyUsedIcons(); } return _.map(groups, function(g, i){ var row = {src: Discourse.Emoji.urlFor(g.icons[0]), groupId: i}; - if(i===selected){ + if(i === selected){ row.selected = true; } return row; @@ -80,9 +119,11 @@ var bindEvents = function(page,offset){ var composerController = Discourse.__container__.lookup('controller:composer'); $('.emoji-page a').click(function(){ - composerController.appendTextAtCursor(":" + $(this).attr('title') + ":", {space: true}); - closeSelector(); - return false; + var title = $(this).attr('title'); + trackEmojiUsage(title) + composerController.appendTextAtCursor(":" + title + ":", {space: true}); + closeSelector(); + return false; }).hover(function(){ var title = $(this).attr('title'); var html = " :" + title + ":"; diff --git a/vendor/assets/javascripts/lodash.js b/vendor/assets/javascripts/lodash.js index d3348caf0..1baaa037b 100644 --- a/vendor/assets/javascripts/lodash.js +++ b/vendor/assets/javascripts/lodash.js @@ -1,165 +1,320 @@ /** * @license - * Lo-Dash 1.3.0 (Custom Build) - * Build: `lodash minus="template" -d` - * Copyright 2012-2013 The Dojo Foundation - * Based on Underscore.js 1.4.4 - * Copyright 2009-2013 Jeremy Ashkenas, DocumentCloud Inc. - * Available under MIT license + * lodash 3.0.1 (Custom Build) + * Build: `lodash modern -o ./lodash.js` + * Copyright 2012-2015 The Dojo Foundation + * Based on Underscore.js 1.7.0 + * Copyright 2009-2015 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors + * Available under MIT license */ -;(function(window) { +;(function() { - /** Used as a safe reference for `undefined` in pre ES5 environments */ + /** 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 as the semantic version number. */ + var VERSION = '3.0.1'; - /** Used to generate unique IDs */ - var idCounter = 0; + /** Used to compose bitmasks for wrapper metadata. */ + var BIND_FLAG = 1, + BIND_KEY_FLAG = 2, + CURRY_BOUND_FLAG = 4, + CURRY_FLAG = 8, + CURRY_RIGHT_FLAG = 16, + PARTIAL_FLAG = 32, + PARTIAL_RIGHT_FLAG = 64, + REARG_FLAG = 128, + ARY_FLAG = 256; - /** Used internally to indicate various things */ - var indicatorObject = {}; + /** Used as default options for `_.trunc`. */ + var DEFAULT_TRUNC_LENGTH = 30, + DEFAULT_TRUNC_OMISSION = '...'; - /** Used to prefix keys to avoid issues with `__proto__` and properties on `Object.prototype` */ - var keyPrefix = +new Date + ''; + /** Used to detect when a function becomes hot. */ + var HOT_COUNT = 150, + HOT_SPAN = 16; - /** Used as the size when optimizations are enabled for large arrays */ - var largeArraySize = 75; + /** Used to indicate the type of lazy iteratees. */ + var LAZY_FILTER_FLAG = 0, + LAZY_MAP_FLAG = 1, + LAZY_WHILE_FLAG = 2; - /** Used as the max size of the `arrayPool` and `objectPool` */ - var maxPoolSize = 10; + /** Used as the `TypeError` message for "Functions" methods. */ + var FUNC_ERROR_TEXT = 'Expected a function'; - /** Used to match empty string literals in compiled template source */ + /** Used as the internal argument placeholder. */ + var PLACEHOLDER = '__lodash_placeholder__'; + + /** `Object#toString` result references. */ + var argsTag = '[object Arguments]', + arrayTag = '[object Array]', + boolTag = '[object Boolean]', + dateTag = '[object Date]', + errorTag = '[object Error]', + funcTag = '[object Function]', + mapTag = '[object Map]', + numberTag = '[object Number]', + objectTag = '[object Object]', + regexpTag = '[object RegExp]', + setTag = '[object Set]', + stringTag = '[object String]', + weakMapTag = '[object WeakMap]'; + + var arrayBufferTag = '[object ArrayBuffer]', + float32Tag = '[object Float32Array]', + float64Tag = '[object Float64Array]', + int8Tag = '[object Int8Array]', + int16Tag = '[object Int16Array]', + int32Tag = '[object Int32Array]', + uint8Tag = '[object Uint8Array]', + uint8ClampedTag = '[object Uint8ClampedArray]', + uint16Tag = '[object Uint16Array]', + uint32Tag = '[object Uint32Array]'; + + /** 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 HTML entities */ - var reEscapedHtml = /&(?:amp|lt|gt|quot|#39);/g; + /** Used to match HTML entities and HTML characters. */ + var reEscapedHtml = /&(?:amp|lt|gt|quot|#39|#96);/g, + reUnescapedHtml = /[&<>"'`]/g, + reHasEscapedHtml = RegExp(reEscapedHtml.source), + reHasUnescapedHtml = RegExp(reUnescapedHtml.source); + + /** Used to match template delimiters. */ + var reEscape = /<%-([\s\S]+?)%>/g, + reEvaluate = /<%([\s\S]+?)%>/g, + reInterpolate = /<%=([\s\S]+?)%>/g; /** - * Used to match ES6 template delimiters - * http://people.mozilla.org/~jorendorff/es6-draft.html#sec-7.8.6 + * Used to match ES template delimiters. + * See the [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-template-literal-lexical-components) + * for more details. */ var reEsTemplate = /\$\{([^\\}]*(?:\\.[^\\}]*)*)\}/g; - /** Used to match regexp flags from their coerced string values */ + /** Used to match `RegExp` flags from their coerced string values. */ var reFlags = /\w*$/; - /** Used to match "interpolate" template delimiters */ - var reInterpolate = /<%=([\s\S]+?)%>/g; + /** Used to detect named functions. */ + var reFuncName = /^\s*function[ \n\r\t]+\w/; - /** Used to detect functions containing a `this` reference */ - var reThis = (reThis = /\bthis\b/) && reThis.test(runInContext) && reThis; + /** Used to detect hexadecimal string values. */ + var reHexPrefix = /^0[xX]/; - /** Used to detect and test whitespace */ + /** Used to detect host constructors (Safari > 5). */ + var reHostCtor = /^\[object .+?Constructor\]$/; + + /** Used to match latin-1 supplementary letters (excluding mathematical operators). */ + var reLatin1 = /[\xc0-\xd6\xd8-\xde\xdf-\xf6\xf8-\xff]/g; + + /** Used to ensure capturing order of template delimiters. */ + var reNoMatch = /($^)/; + + /** + * Used to match `RegExp` special characters. + * See this [article on `RegExp` characters](http://www.regular-expressions.info/characters.html#special) + * for more details. + */ + var reRegExpChars = /[.*+?^${}()|[\]\/\\]/g, + reHasRegExpChars = RegExp(reRegExpChars.source); + + /** 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\u2028\u2029\\]/g; + + /** Used to match words to create compound words. */ + var reWords = (function() { + var upper = '[A-Z\\xc0-\\xd6\\xd8-\\xde]', + lower = '[a-z\\xdf-\\xf6\\xf8-\\xff]+'; + + return RegExp(upper + '{2,}(?=' + upper + lower + ')|' + upper + '?' + lower + '|' + upper + '+|[0-9]+', 'g'); + }()); + + /** Used to detect and test for whitespace. */ var whitespace = ( - // whitespace - ' \t\x0B\f\xA0\ufeff' + + // Basic whitespace characters. + ' \t\x0b\f\xa0\ufeff' + - // line terminators + // Line terminators. '\n\r\u2028\u2029' + - // unicode category "Zs" space separators + // Unicode category "Zs" space separators. '\u1680\u180e\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u202f\u205f\u3000' ); - /** 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 match HTML characters */ - var reUnescapedHtml = /[&<>"']/g; - - /** Used to match unescaped characters in compiled string literals */ - var reUnescapedString = /['\n\r\t\u2028\u2029\\]/g; - - /** Used to assign default `context` object properties */ + /** Used to assign default `context` object properties. */ var contextProps = [ - 'Array', 'Boolean', 'Date', 'Error', 'Function', 'Math', 'Number', 'Object', - 'RegExp', 'String', '_', 'attachEvent', 'clearTimeout', 'isFinite', 'isNaN', - 'parseInt', 'setImmediate', 'setTimeout' + 'Array', 'ArrayBuffer', 'Date', 'Error', 'Float32Array', 'Float64Array', + 'Function', 'Int8Array', 'Int16Array', 'Int32Array', 'Math', 'Number', + 'Object', 'RegExp', 'Set', 'String', '_', 'clearTimeout', 'document', + 'isFinite', 'parseInt', 'setTimeout', 'TypeError', 'Uint8Array', + 'Uint8ClampedArray', 'Uint16Array', 'Uint32Array', 'WeakMap', + 'window', 'WinRTError' ]; - /** Used to fix the JScript [[DontEnum]] bug */ - var shadowedProps = [ - 'constructor', 'hasOwnProperty', 'isPrototypeOf', 'propertyIsEnumerable', - 'toLocaleString', 'toString', 'valueOf' - ]; + /** Used to make template sourceURLs easier to identify. */ + var templateCounter = -1; - /** Used to make template sourceURLs easier to identify */ - var templateCounter = 0; + /** Used to identify `toStringTag` values of typed arrays. */ + var typedArrayTags = {}; + typedArrayTags[float32Tag] = typedArrayTags[float64Tag] = + typedArrayTags[int8Tag] = typedArrayTags[int16Tag] = + typedArrayTags[int32Tag] = typedArrayTags[uint8Tag] = + typedArrayTags[uint8ClampedTag] = typedArrayTags[uint16Tag] = + typedArrayTags[uint32Tag] = true; + typedArrayTags[argsTag] = typedArrayTags[arrayTag] = + typedArrayTags[arrayBufferTag] = typedArrayTags[boolTag] = + typedArrayTags[dateTag] = typedArrayTags[errorTag] = + typedArrayTags[funcTag] = typedArrayTags[mapTag] = + typedArrayTags[numberTag] = typedArrayTags[objectTag] = + typedArrayTags[regexpTag] = typedArrayTags[setTag] = + typedArrayTags[stringTag] = typedArrayTags[weakMapTag] = false; - /** `Object#toString` result shortcuts */ - var argsClass = '[object Arguments]', - arrayClass = '[object Array]', - boolClass = '[object Boolean]', - dateClass = '[object Date]', - errorClass = '[object Error]', - funcClass = '[object Function]', - numberClass = '[object Number]', - objectClass = '[object Object]', - regexpClass = '[object RegExp]', - stringClass = '[object String]'; + /** Used to identify `toStringTag` values supported by `_.clone`. */ + var cloneableTags = {}; + cloneableTags[argsTag] = cloneableTags[arrayTag] = + cloneableTags[arrayBufferTag] = cloneableTags[boolTag] = + cloneableTags[dateTag] = cloneableTags[float32Tag] = + cloneableTags[float64Tag] = cloneableTags[int8Tag] = + cloneableTags[int16Tag] = cloneableTags[int32Tag] = + cloneableTags[numberTag] = cloneableTags[objectTag] = + cloneableTags[regexpTag] = cloneableTags[stringTag] = + cloneableTags[uint8Tag] = cloneableTags[uint8ClampedTag] = + cloneableTags[uint16Tag] = cloneableTags[uint32Tag] = true; + cloneableTags[errorTag] = cloneableTags[funcTag] = + cloneableTags[mapTag] = cloneableTags[setTag] = + cloneableTags[weakMapTag] = false; - /** 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 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 as an internal `_.debounce` options object by `_.throttle`. */ + var debounceOptions = { + 'leading': false, + 'maxWait': 0, + 'trailing': false }; - /** Used to escape characters for inclusion in compiled string literals */ + /** Used to map latin-1 supplementary letters to basic latin letters. */ + var deburredLetters = { + '\xc0': 'A', '\xc1': 'A', '\xc2': 'A', '\xc3': 'A', '\xc4': 'A', '\xc5': 'A', + '\xe0': 'a', '\xe1': 'a', '\xe2': 'a', '\xe3': 'a', '\xe4': 'a', '\xe5': 'a', + '\xc7': 'C', '\xe7': 'c', + '\xd0': 'D', '\xf0': 'd', + '\xc8': 'E', '\xc9': 'E', '\xca': 'E', '\xcb': 'E', + '\xe8': 'e', '\xe9': 'e', '\xea': 'e', '\xeb': 'e', + '\xcC': 'I', '\xcd': 'I', '\xce': 'I', '\xcf': 'I', + '\xeC': 'i', '\xed': 'i', '\xee': 'i', '\xef': 'i', + '\xd1': 'N', '\xf1': 'n', + '\xd2': 'O', '\xd3': 'O', '\xd4': 'O', '\xd5': 'O', '\xd6': 'O', '\xd8': 'O', + '\xf2': 'o', '\xf3': 'o', '\xf4': 'o', '\xf5': 'o', '\xf6': 'o', '\xf8': 'o', + '\xd9': 'U', '\xda': 'U', '\xdb': 'U', '\xdc': 'U', + '\xf9': 'u', '\xfa': 'u', '\xfb': 'u', '\xfc': 'u', + '\xdd': 'Y', '\xfd': 'y', '\xff': 'y', + '\xc6': 'Ae', '\xe6': 'ae', + '\xde': 'Th', '\xfe': 'th', + '\xdf': 'ss' + }; + + /** Used to map characters to HTML entities. */ + var htmlEscapes = { + '&': '&', + '<': '<', + '>': '>', + '"': '"', + "'": ''', + '`': '`' + }; + + /** Used to map HTML entities to characters. */ + var htmlUnescapes = { + '&': '&', + '<': '<', + '>': '>', + '"': '"', + ''': "'", + '`': '`' + }; + + /** Used to determine if values are of the language type `Object`. */ + var objectTypes = { + 'function': true, + 'object': true + }; + + /** Used to escape characters for inclusion in compiled string literals. */ var stringEscapes = { '\\': '\\', "'": "'", '\n': 'n', '\r': 'r', - '\t': 't', '\u2028': 'u2028', '\u2029': 'u2029' }; - /** Detect free variable `exports` */ - var freeExports = objectTypes[typeof exports] && exports; + /** + * Used as a reference to the global object. + * + * The `this` value is used if it is the global object to avoid Greasemonkey's + * restricted `window` object, otherwise the `window` object is used. + */ + var root = (objectTypes[typeof window] && window !== (this && this.window)) ? window : this; - /** Detect free variable `module` */ - var freeModule = objectTypes[typeof module] && module && module.exports == freeExports && module; + /** Detect free variable `exports`. */ + var freeExports = objectTypes[typeof exports] && exports && !exports.nodeType && exports; - /** Detect free variable `global`, from Node.js or Browserified code, and use it as `window` */ - var freeGlobal = objectTypes[typeof global] && global; - if (freeGlobal && (freeGlobal.global === freeGlobal || freeGlobal.window === freeGlobal)) { - window = freeGlobal; + /** Detect free variable `module`. */ + var freeModule = objectTypes[typeof module] && module && !module.nodeType && module; + + /** Detect free variable `global` from Node.js or Browserified code and use it as `root`. */ + var freeGlobal = freeExports && freeModule && typeof global == 'object' && global; + if (freeGlobal && (freeGlobal.global === freeGlobal || freeGlobal.window === freeGlobal || freeGlobal.self === freeGlobal)) { + root = freeGlobal; } + /** Detect the popular CommonJS extension `module.exports`. */ + var moduleExports = freeModule && freeModule.exports === freeExports && freeExports; + /*--------------------------------------------------------------------------*/ /** - * A basic implementation of `_.indexOf` without support for binary searches - * or `fromIndex` constraints. + * The base implementation of `compareAscending` which compares values and + * sorts them in ascending order without guaranteeing a stable sort. + * + * @private + * @param {*} value The value to compare to `other`. + * @param {*} other The value to compare to `value`. + * @returns {number} Returns the sort order indicator for `value`. + */ + function baseCompareAscending(value, other) { + if (value !== other) { + var valIsReflexive = value === value, + othIsReflexive = other === other; + + if (value > other || !valIsReflexive || (typeof value == 'undefined' && othIsReflexive)) { + return 1; + } + if (value < other || !othIsReflexive || (typeof other == 'undefined' && valIsReflexive)) { + return -1; + } + } + return 0; + } + + /** + * The base implementation of `_.indexOf` without support for binary searches. * * @private * @param {Array} array The array to search. - * @param {Mixed} value The value to search for. - * @param {Number} [fromIndex=0] The index to search from. - * @returns {Number} Returns the index of the matched value or `-1`. + * @param {*} value The value to search for. + * @param {number} [fromIndex=0] The index to search from. + * @returns {number} Returns the index of the matched value, else `-1`. */ - function basicIndexOf(array, value, fromIndex) { + function baseIndexOf(array, value, fromIndex) { + if (value !== value) { + return indexOfNaN(array, fromIndex); + } var index = (fromIndex || 0) - 1, length = array.length; @@ -172,289 +327,349 @@ } /** - * An implementation of `_.contains` for cache objects that mimics the return - * signature of `_.indexOf` by returning `0` if the value is found, else `-1`. + * The base implementation of `_.sortBy` and `_.sortByAll` which uses `comparer` + * to define the sort order of `array` and replaces criteria objects with their + * corresponding values. * * @private - * @param {Object} cache The cache object to inspect. - * @param {Mixed} value The value to search for. - * @returns {Number} Returns `0` if `value` is found, else `-1`. + * @param {Array} array The array to sort. + * @param {Function} comparer The function to define sort order. + * @returns {Array} Returns `array`. */ - function cacheIndexOf(cache, value) { - var type = typeof value; - cache = cache.cache; + function baseSortBy(array, comparer) { + var length = array.length; - if (type == 'boolean' || value == null) { - return cache[value]; + array.sort(comparer); + while (length--) { + array[length] = array[length].value; } - if (type != 'number' && type != 'string') { - type = 'object'; - } - var key = type == 'number' ? value : keyPrefix + value; - cache = cache[type] || (cache[type] = {}); - - return type == 'object' - ? (cache[key] && basicIndexOf(cache[key], value) > -1 ? 0 : -1) - : (cache[key] ? 0 : -1); + return array; } /** - * Adds a given `value` to the corresponding cache object. + * Converts `value` to a string if it is not one. An empty string is returned + * for `null` or `undefined` values. * * @private - * @param {Mixed} value The value to add to the cache. + * @param {*} value The value to process. + * @returns {string} Returns the string. */ - 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') { - if ((typeCache[key] || (typeCache[key] = [])).push(value) == this.array.length) { - cache[type] = false; - } - } else { - typeCache[key] = true; - } + function baseToString(value) { + if (typeof value == 'string') { + return value; } + return value == null ? '' : (value + ''); } /** - * Used by `_.max` and `_.min` as the default `callback` when a given - * `collection` is a string value. + * Used by `_.max` and `_.min` as the default callback for string values. * * @private - * @param {String} value The character to inspect. - * @returns {Number} Returns the code unit of given character. + * @param {string} string The string to inspect. + * @returns {number} Returns the code unit of the first character of the string. */ - function charAtCallback(value) { - return value.charCodeAt(0); + function charAtCallback(string) { + return string.charCodeAt(0); } /** - * Used by `sortBy` to compare transformed `collection` values, stable sorting - * them in ascending order. + * Used by `_.trim` and `_.trimLeft` to get the index of the first character + * of `string` that is not found in `chars`. * * @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`. + * @param {string} string The string to inspect. + * @param {string} chars The characters to find. + * @returns {number} Returns the index of the first character not found in `chars`. */ - function compareAscending(a, b) { - var ai = a.index, - bi = b.index; - - a = a.criteria; - b = b.criteria; - - // ensure a stable sort in V8 and other engines - // http://code.google.com/p/v8/issues/detail?id=90 - if (a !== b) { - if (a > b || typeof a == 'undefined') { - return 1; - } - if (a < b || typeof b == 'undefined') { - return -1; - } - } - return ai < bi ? -1 : 1; - } - - /** - * 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) { + function charsLeftIndex(string, chars) { var index = -1, - length = array.length; + length = string.length; - var cache = getObject(); - cache['false'] = cache['null'] = cache['true'] = cache['undefined'] = false; + while (++index < length && chars.indexOf(string.charAt(index)) > -1) {} + return index; + } - var result = getObject(); - result.array = array; - result.cache = cache; - result.push = cachePush; + /** + * Used by `_.trim` and `_.trimRight` to get the index of the last character + * of `string` that is not found in `chars`. + * + * @private + * @param {string} string The string to inspect. + * @param {string} chars The characters to find. + * @returns {number} Returns the index of the last character not found in `chars`. + */ + function charsRightIndex(string, chars) { + var index = string.length; + + while (index-- && chars.indexOf(string.charAt(index)) > -1) {} + return index; + } + + /** + * Used by `_.sortBy` to compare transformed elements of a collection and stable + * sort them in ascending order. + * + * @private + * @param {Object} object The object to compare to `other`. + * @param {Object} other The object to compare to `object`. + * @returns {number} Returns the sort order indicator for `object`. + */ + function compareAscending(object, other) { + return baseCompareAscending(object.criteria, other.criteria) || (object.index - other.index); + } + + /** + * Used by `_.sortByAll` to compare multiple properties of each element + * in a collection and stable sort them in ascending order. + * + * @private + * @param {Object} object The object to compare to `other`. + * @param {Object} other The object to compare to `object`. + * @returns {number} Returns the sort order indicator for `object`. + */ + function compareMultipleAscending(object, other) { + var index = -1, + objCriteria = object.criteria, + othCriteria = other.criteria, + length = objCriteria.length; while (++index < length) { - result.push(array[index]); + var result = baseCompareAscending(objCriteria[index], othCriteria[index]); + if (result) { + return result; + } } - return cache.object === false - ? (releaseObject(result), null) - : result; + // Fixes an `Array#sort` bug in the JS engine embedded in Adobe applications + // that causes it, under certain circumstances, to provide the same value for + // `object` and `other`. See https://github.com/jashkenas/underscore/pull/1247 + // for more details. + // + // This also ensures a stable sort in V8 and other engines. + // See https://code.google.com/p/v8/issues/detail?id=90 for more details. + return object.index - other.index; } /** - * Used by `template` to escape characters for inclusion in compiled + * Used by `_.deburr` to convert latin-1 supplementary letters to basic latin letters. + * + * @private + * @param {string} letter The matched letter to deburr. + * @returns {string} Returns the deburred letter. + */ + function deburrLetter(letter) { + return deburredLetters[letter]; + } + + /** + * Used by `_.escape` to convert characters to HTML entities. + * + * @private + * @param {string} chr The matched character to escape. + * @returns {string} Returns the escaped character. + */ + function escapeHtmlChar(chr) { + return htmlEscapes[chr]; + } + + /** + * Used by `_.template` to escape characters for inclusion in compiled * string literals. * * @private - * @param {String} match The matched character to escape. - * @returns {String} Returns the escaped character. + * @param {string} chr The matched character to escape. + * @returns {string} Returns the escaped character. */ - function escapeStringChar(match) { - return '\\' + stringEscapes[match]; + function escapeStringChar(chr) { + return '\\' + stringEscapes[chr]; } /** - * Gets an array from the array pool or creates a new one if the pool is empty. + * Gets the index at which the first occurrence of `NaN` is found in `array`. + * If `fromRight` is provided elements of `array` are iterated from right to left. * * @private - * @returns {Array} The array from the pool. + * @param {Array} array The array to search. + * @param {number} [fromIndex] The index to search from. + * @param {boolean} [fromRight] Specify iterating from right to left. + * @returns {number} Returns the index of the matched `NaN`, else `-1`. */ - function getArray() { - return arrayPool.pop() || []; - } + function indexOfNaN(array, fromIndex, fromRight) { + var length = array.length, + index = fromRight ? (fromIndex || length) : ((fromIndex || 0) - 1); - /** - * 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() || { - 'args': '', - 'array': null, - 'bottom': '', - 'criteria': null, - 'false': false, - 'firstArg': '', - 'index': 0, - 'init': '', - 'leading': false, - 'loop': '', - 'maxWait': 0, - 'null': false, - 'number': null, - 'object': null, - 'push': null, - 'shadowedProps': null, - 'string': null, - 'top': '', - 'trailing': false, - 'true': false, - 'undefined': false, - 'useHas': false, - 'useKeys': false, - 'value': null - }; - } - - /** - * Checks if `value` is a DOM node in IE < 9. - * - * @private - * @param {Mixed} value The value to check. - * @returns {Boolean} Returns `true` if the `value` is a DOM node, else `false`. - */ - function isNode(value) { - // IE < 9 presents DOM nodes as `Object` objects except they have `toString` - // methods that are `typeof` "string" and still can coerce nodes to strings - return typeof value.toString != 'function' && typeof (value + '') == 'string'; - } - - /** - * A no-operation function. - * - * @private - */ - function noop() { - // no operation performed - } - - /** - * Releases the given `array` back to the array pool. - * - * @private - * @param {Array} [array] The array to release. - */ - function releaseArray(array) { - if (arrayPool.length == maxPoolSize) { - arrayPool.length = maxPoolSize - 1; + while ((fromRight ? index-- : ++index < length)) { + var other = array[index]; + if (other !== other) { + return index; + } } - array.length = 0; - arrayPool.push(array); + return -1; } /** - * Releases the given `object` back to the object pool. + * Checks if `value` is object-like. * * @private - * @param {Object} [object] The object to release. + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is object-like, else `false`. */ - function releaseObject(object) { - var cache = object.cache; - if (cache) { - releaseObject(cache); - } - if (objectPool.length == maxPoolSize) { - objectPool.length = maxPoolSize - 1; - } - object.array = object.cache = object.criteria = object.object = object.number = object.string = object.value = null; - objectPool.push(object); + function isObjectLike(value) { + return (value && typeof value == 'object') || false; } /** - * 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. + * Used by `trimmedLeftIndex` and `trimmedRightIndex` to determine if a + * character code is whitespace. * * @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. + * @param {number} charCode The character code to inspect. + * @returns {boolean} Returns `true` if `charCode` is whitespace, else `false`. */ - function slice(array, start, end) { - start || (start = 0); - if (typeof end == 'undefined') { - end = array ? array.length : 0; - } + function isSpace(charCode) { + return ((charCode <= 160 && (charCode >= 9 && charCode <= 13) || charCode == 32 || charCode == 160) || charCode == 5760 || charCode == 6158 || + (charCode >= 8192 && (charCode <= 8202 || charCode == 8232 || charCode == 8233 || charCode == 8239 || charCode == 8287 || charCode == 12288 || charCode == 65279))); + } + + /** + * Replaces all `placeholder` elements in `array` with an internal placeholder + * and returns an array of their indexes. + * + * @private + * @param {Array} array The array to modify. + * @param {*} placeholder The placeholder to replace. + * @returns {Array} Returns the new array of placeholder indexes. + */ + function replaceHolders(array, placeholder) { var index = -1, - length = end - start || 0, - result = Array(length < 0 ? 0 : length); + length = array.length, + resIndex = -1, + result = []; while (++index < length) { - result[index] = array[start + index]; + if (array[index] === placeholder) { + array[index] = PLACEHOLDER; + result[++resIndex] = index; + } } return result; } + /** + * An implementation of `_.uniq` optimized for sorted arrays without support + * for callback shorthands and `this` binding. + * + * @private + * @param {Array} array The array to inspect. + * @param {Function} [iteratee] The function invoked per iteration. + * @returns {Array} Returns the new duplicate-value-free array. + */ + function sortedUniq(array, iteratee) { + var seen, + index = -1, + length = array.length, + resIndex = -1, + result = []; + + while (++index < length) { + var value = array[index], + computed = iteratee ? iteratee(value, index, array) : value; + + if (!index || seen !== computed) { + seen = computed; + result[++resIndex] = value; + } + } + return result; + } + + /** + * Used by `_.trim` and `_.trimLeft` to get the index of the first non-whitespace + * character of `string`. + * + * @private + * @param {string} string The string to inspect. + * @returns {number} Returns the index of the first non-whitespace character. + */ + function trimmedLeftIndex(string) { + var index = -1, + length = string.length; + + while (++index < length && isSpace(string.charCodeAt(index))) {} + return index; + } + + /** + * Used by `_.trim` and `_.trimRight` to get the index of the last non-whitespace + * character of `string`. + * + * @private + * @param {string} string The string to inspect. + * @returns {number} Returns the index of the last non-whitespace character. + */ + function trimmedRightIndex(string) { + var index = string.length; + + while (index-- && isSpace(string.charCodeAt(index))) {} + return index; + } + + /** + * Used by `_.unescape` to convert HTML entities to characters. + * + * @private + * @param {string} chr The matched character to unescape. + * @returns {string} Returns the unescaped character. + */ + function unescapeHtmlChar(chr) { + return htmlUnescapes[chr]; + } + /*--------------------------------------------------------------------------*/ /** - * Create a new `lodash` function using the given `context` object. + * Create a new pristine `lodash` function using the given `context` object. * * @static * @memberOf _ - * @category Utilities - * @param {Object} [context=window] The context object. - * @returns {Function} Returns the `lodash` function. + * @category Utility + * @param {Object} [context=root] The context object. + * @returns {Function} Returns a new `lodash` function. + * @example + * + * _.mixin({ 'add': function(a, b) { return a + b; } }); + * + * var lodash = _.runInContext(); + * lodash.mixin({ 'sub': function(a, b) { return a - b; } }); + * + * _.isFunction(_.add); + * // => true + * _.isFunction(_.sub); + * // => false + * + * lodash.isFunction(lodash.add); + * // => false + * lodash.isFunction(lodash.sub); + * // => true + * + * // using `context` to mock `Date#getTime` use in `_.now` + * var mock = _.runInContext({ + * 'Date': function() { + * return { 'getTime': getTimeMock }; + * } + * }); + * + * // or creating a suped-up `defer` in Node.js + * var defer = _.runInContext({ 'setTimeout': setImmediate }).defer; */ 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.com/#x11.1.5. - context = context ? _.defaults(window.Object(), context, _.pick(window, contextProps)) : window; + // See https://es5.github.io/#x11.1.5 for more details. + context = context ? _.defaults(root.Object(), context, _.pick(root, contextProps)) : root; - /** Native constructor references */ + /** Native constructor references. */ var Array = context.Array, - Boolean = context.Boolean, Date = context.Date, Error = context.Error, Function = context.Function, @@ -465,146 +680,180 @@ String = context.String, TypeError = context.TypeError; + /** Used for native method references. */ + var arrayProto = Array.prototype, + objectProto = Object.prototype; + + /** Used to detect DOM support. */ + var document = (document = context.window) && document.document; + + /** Used to resolve the decompiled source of functions. */ + var fnToString = Function.prototype.toString; + + /** Used to the length of n-tuples for `_.unzip`. */ + var getLength = baseProperty('length'); + + /** Used to check objects for own properties. */ + var hasOwnProperty = objectProto.hasOwnProperty; + + /** Used to generate unique IDs. */ + var idCounter = 0; + /** - * Used for `Array` method references. - * - * Normally `Array.prototype` would suffice, however, using an array literal - * avoids issues in Narwhal. + * Used to resolve the `toStringTag` of values. + * See the [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.prototype.tostring) + * for more details. */ - var arrayRef = []; + var objToString = objectProto.toString; - /** Used for native method references */ - var errorProto = Error.prototype, - objectProto = Object.prototype, - stringProto = String.prototype; - - /** Used to restore the original `_` reference in `noConflict` */ + /** Used to restore the original `_` reference in `_.noConflict`. */ var oldDash = context._; - /** Used to detect if a method is native */ + /** Used to detect if a method is native. */ var reNative = RegExp('^' + - String(objectProto.valueOf) - .replace(/[.*+?^${}()|[\]\\]/g, '\\$&') - .replace(/valueOf|for [^\]]+/g, '.+?') + '$' + escapeRegExp(objToString) + .replace(/toString|(function).*?(?=\\\()| for .+?(?=\\\])/g, '$1.*?') + '$' ); - /** Native method shortcuts */ - var ceil = Math.ceil, + /** Native method references. */ + var ArrayBuffer = isNative(ArrayBuffer = context.ArrayBuffer) && ArrayBuffer, + bufferSlice = isNative(bufferSlice = ArrayBuffer && new ArrayBuffer(0).slice) && bufferSlice, + ceil = Math.ceil, clearTimeout = context.clearTimeout, - concat = arrayRef.concat, floor = Math.floor, - fnToString = Function.prototype.toString, - getPrototypeOf = reNative.test(getPrototypeOf = Object.getPrototypeOf) && getPrototypeOf, - hasOwnProperty = objectProto.hasOwnProperty, - push = arrayRef.push, + getPrototypeOf = isNative(getPrototypeOf = Object.getPrototypeOf) && getPrototypeOf, + push = arrayProto.push, propertyIsEnumerable = objectProto.propertyIsEnumerable, - setImmediate = context.setImmediate, + Set = isNative(Set = context.Set) && Set, setTimeout = context.setTimeout, - toString = objectProto.toString; + splice = arrayProto.splice, + Uint8Array = isNative(Uint8Array = context.Uint8Array) && Uint8Array, + unshift = arrayProto.unshift, + WeakMap = isNative(WeakMap = context.WeakMap) && WeakMap; - /* Native method shortcuts for methods with the same name as other `lodash` methods */ - var nativeBind = reNative.test(nativeBind = toString.bind) && nativeBind, - nativeCreate = reNative.test(nativeCreate = Object.create) && nativeCreate, - nativeIsArray = reNative.test(nativeIsArray = Array.isArray) && nativeIsArray, - nativeIsFinite = context.isFinite, - nativeIsNaN = context.isNaN, - nativeKeys = reNative.test(nativeKeys = Object.keys) && nativeKeys, - nativeMax = Math.max, - nativeMin = Math.min, - nativeParseInt = context.parseInt, - nativeRandom = Math.random, - nativeSlice = arrayRef.slice; - - /** Detect various environments */ - var isIeOpera = reNative.test(context.attachEvent), - isV8 = nativeBind && !/\n|true/.test(nativeBind + isIeOpera); - - /** 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; - - /** Used to avoid iterating non-enumerable properties in IE < 9 */ - var nonEnumProps = {}; - nonEnumProps[arrayClass] = nonEnumProps[dateClass] = nonEnumProps[numberClass] = { 'constructor': true, 'toLocaleString': true, 'toString': true, 'valueOf': true }; - nonEnumProps[boolClass] = nonEnumProps[stringClass] = { 'constructor': true, 'toString': true, 'valueOf': true }; - nonEnumProps[errorClass] = nonEnumProps[funcClass] = nonEnumProps[regexpClass] = { 'constructor': true, 'toString': true }; - nonEnumProps[objectClass] = { 'constructor': true }; - - (function() { - var length = shadowedProps.length; - while (length--) { - var prop = shadowedProps[length]; - for (var className in nonEnumProps) { - if (hasOwnProperty.call(nonEnumProps, className) && !hasOwnProperty.call(nonEnumProps[className], prop)) { - nonEnumProps[className][prop] = false; - } - } - } + /** Used to clone array buffers. */ + var Float64Array = (function() { + // Safari 5 errors when using an array buffer to initialize a typed array + // where the array buffer's `byteLength` is not a multiple of the typed + // array's `BYTES_PER_ELEMENT`. + try { + var func = isNative(func = context.Float64Array) && func, + result = new func(new ArrayBuffer(10), 0, 1) && func; + } catch(e) {} + return result; }()); - /*--------------------------------------------------------------------------*/ + /* Native method references for those with the same name as other `lodash` methods. */ + var nativeIsArray = isNative(nativeIsArray = Array.isArray) && nativeIsArray, + nativeCreate = isNative(nativeCreate = Object.create) && nativeCreate, + nativeIsFinite = context.isFinite, + nativeKeys = isNative(nativeKeys = Object.keys) && nativeKeys, + nativeMax = Math.max, + nativeMin = Math.min, + nativeNow = isNative(nativeNow = Date.now) && nativeNow, + nativeNumIsFinite = isNative(nativeNumIsFinite = Number.isFinite) && nativeNumIsFinite, + nativeParseInt = context.parseInt, + nativeRandom = Math.random; + + /** Used as references for `-Infinity` and `Infinity`. */ + var NEGATIVE_INFINITY = Number.NEGATIVE_INFINITY, + POSITIVE_INFINITY = Number.POSITIVE_INFINITY; + + /** Used as references for the maximum length and index of an array. */ + var MAX_ARRAY_LENGTH = Math.pow(2, 32) - 1, + MAX_ARRAY_INDEX = MAX_ARRAY_LENGTH - 1, + HALF_MAX_ARRAY_LENGTH = MAX_ARRAY_LENGTH >>> 1; + + /** Used as the size, in bytes, of each `Float64Array` element. */ + var FLOAT64_BYTES_PER_ELEMENT = Float64Array ? Float64Array.BYTES_PER_ELEMENT : 0; /** - * Creates a `lodash` object, which wraps the given `value`, to enable method - * chaining. + * Used as the maximum length of an array-like value. + * See the [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-tolength) + * for more details. + */ + var MAX_SAFE_INTEGER = Math.pow(2, 53) - 1; + + /** Used to store function metadata. */ + var metaMap = WeakMap && new WeakMap; + + /*------------------------------------------------------------------------*/ + + /** + * Creates a `lodash` object which wraps `value` to enable intuitive chaining. + * Methods that operate on and return arrays, collections, and functions can + * be chained together. Methods that return a boolean or single value will + * automatically end the chain returning the unwrapped value. Explicit chaining + * may be enabled using `_.chain`. The execution of chained methods is lazy, + * that is, execution is deferred until `_#value` is implicitly or explicitly + * called. * - * In addition to Lo-Dash methods, wrappers also have the following `Array` methods: + * Lazy evaluation allows several methods to support shortcut fusion. Shortcut + * fusion is an optimization that merges iteratees to avoid creating intermediate + * arrays and reduce the number of iteratee executions. + * + * Chaining is supported in custom builds as long as the `_#value` method is + * directly or indirectly included in the build. + * + * In addition to lodash 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 wrapper functions that support shortcut fusion are: + * `drop`, `dropRight`, `dropRightWhile`, `dropWhile`, `filter`, `first`, + * `initial`, `last`, `map`, `pluck`, `reject`, `rest`, `reverse`, `slice`, + * `take`, `takeRight`, `takeRightWhile`, `takeWhile`, and `where` * * The chainable wrapper functions are: - * `after`, `assign`, `bind`, `bindAll`, `bindKey`, `chain`, `compact`, - * `compose`, `concat`, `countBy`, `createCallback`, `debounce`, `defaults`, - * `defer`, `delay`, `difference`, `filter`, `flatten`, `forEach`, `forIn`, - * `forOwn`, `functions`, `groupBy`, `initial`, `intersection`, `invert`, - * `invoke`, `keys`, `map`, `max`, `memoize`, `merge`, `min`, `object`, `omit`, - * `once`, `pairs`, `partial`, `partialRight`, `pick`, `pluck`, `push`, `range`, - * `reject`, `rest`, `reverse`, `shuffle`, `slice`, `sort`, `sortBy`, `splice`, - * `tap`, `throttle`, `times`, `toArray`, `transform`, `union`, `uniq`, `unshift`, - * `unzip`, `values`, `where`, `without`, `wrap`, and `zip` + * `after`, `ary`, `assign`, `at`, `before`, `bind`, `bindAll`, `bindKey`, + * `callback`, `chain`, `chunk`, `compact`, `concat`, `constant`, `countBy`, + * `create`, `curry`, `debounce`, `defaults`, `defer`, `delay`, `difference`, + * `drop`, `dropRight`, `dropRightWhile`, `dropWhile`, `filter`, `flatten`, + * `flattenDeep`, `flow`, `flowRight`, `forEach`, `forEachRight`, `forIn`, + * `forInRight`, `forOwn`, `forOwnRight`, `functions`, `groupBy`, `indexBy`, + * `initial`, `intersection`, `invert`, `invoke`, `keys`, `keysIn`, `map`, + * `mapValues`, `matches`, `memoize`, `merge`, `mixin`, `negate`, `noop`, + * `omit`, `once`, `pairs`, `partial`, `partialRight`, `partition`, `pick`, + * `pluck`, `property`, `propertyOf`, `pull`, `pullAt`, `push`, `range`, + * `rearg`, `reject`, `remove`, `rest`, `reverse`, `shuffle`, `slice`, `sort`, + * `sortBy`, `sortByAll`, `splice`, `take`, `takeRight`, `takeRightWhile`, + * `takeWhile`, `tap`, `throttle`, `thru`, `times`, `toArray`, `toPlainObject`, + * `transform`, `union`, `uniq`, `unshift`, `unzip`, `values`, `valuesIn`, + * `where`, `without`, `wrap`, `xor`, `zip`, and `zipObject` * - * The non-chainable wrapper functions are: - * `clone`, `cloneDeep`, `contains`, `escape`, `every`, `find`, `has`, - * `identity`, `indexOf`, `isArguments`, `isArray`, `isBoolean`, `isDate`, - * `isElement`, `isEmpty`, `isEqual`, `isFinite`, `isFunction`, `isNaN`, - * `isNull`, `isNumber`, `isObject`, `isPlainObject`, `isRegExp`, `isString`, - * `isUndefined`, `join`, `lastIndexOf`, `mixin`, `noConflict`, `parseInt`, - * `pop`, `random`, `reduce`, `reduceRight`, `result`, `shift`, `size`, `some`, - * `sortedIndex`, `runInContext`, `template`, `unescape`, `uniqueId`, and `value` + * The wrapper functions that are **not** chainable by default are: + * `attempt`, `camelCase`, `capitalize`, `clone`, `cloneDeep`, `deburr`, + * `endsWith`, `escape`, `escapeRegExp`, `every`, `find`, `findIndex`, `findKey`, + * `findLast`, `findLastIndex`, `findLastKey`, `findWhere`, `first`, `has`, + * `identity`, `includes`, `indexOf`, `isArguments`, `isArray`, `isBoolean`, + * `isDate`, `isElement`, `isEmpty`, `isEqual`, `isError`, `isFinite`, + * `isFunction`, `isMatch` , `isNative`, `isNaN`, `isNull`, `isNumber`, + * `isObject`, `isPlainObject`, `isRegExp`, `isString`, `isUndefined`, + * `isTypedArray`, `join`, `kebabCase`, `last`, `lastIndexOf`, `max`, `min`, + * `noConflict`, `now`, `pad`, `padLeft`, `padRight`, `parseInt`, `pop`, + * `random`, `reduce`, `reduceRight`, `repeat`, `result`, `runInContext`, + * `shift`, `size`, `snakeCase`, `some`, `sortedIndex`, `sortedLastIndex`, + * `startsWith`, `template`, `trim`, `trimLeft`, `trimRight`, `trunc`, + * `unescape`, `uniqueId`, `value`, and `words` * - * The wrapper functions `first` and `last` return wrapped values when `n` is - * passed, otherwise they return unwrapped values. + * The wrapper function `sample` will return a wrapped value when `n` is provided, + * otherwise an unwrapped value is returned. * * @name _ * @constructor - * @alias chain - * @category Chaining - * @param {Mixed} value The value to wrap in a `lodash` instance. + * @category Chain + * @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; - * }); + * wrapped.reduce(function(sum, n) { return sum + n; }); * // => 6 * * // returns a wrapped value - * var squares = wrapped.map(function(num) { - * return num * num; - * }); + * var squares = wrapped.map(function(n) { return n * n; }); * * _.isArray(squares); * // => false @@ -613,27 +862,33 @@ * // => 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); + if (isObjectLike(value) && !isArray(value)) { + if (value instanceof LodashWrapper) { + return value; + } + if (hasOwnProperty.call(value, '__wrapped__')) { + return new LodashWrapper(value.__wrapped__, value.__chain__, arrayCopy(value.__actions__)); + } + } + return new LodashWrapper(value); } /** - * A fast path for creating `lodash` wrapper objects. + * The base constructor for creating `lodash` wrapper objects. * * @private - * @param {Mixed} value The value to wrap in a `lodash` instance. - * @returns {Object} Returns a `lodash` instance. + * @param {*} value The value to wrap. + * @param {boolean} [chainAll] Enable chaining for all wrapper methods. + * @param {Array} [actions=[]] Actions to peform to resolve the unwrapped value. */ - function lodashWrapper(value) { + function LodashWrapper(value, chainAll, actions) { + this.__actions__ = actions || []; + 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. + * An object environment feature flags. * * @static * @memberOf _ @@ -641,752 +896,810 @@ */ var support = lodash.support = {}; - (function() { - var ctor = function() { this.x = 1; }, - object = { '0': 1, 'length': 1 }, - props = []; - - ctor.prototype = { 'valueOf': 1, 'y': 1 }; - for (var prop in new ctor) { props.push(prop); } - for (prop in arguments) { } + (function(x) { /** - * Detect if `arguments` objects are `Object` objects (all but Narwhal and Opera < 10.5). + * Detect if functions can be decompiled by `Function#toString` + * (all but Firefox OS certified apps, older Opera mobile browsers, and + * the PlayStation 3; forced `false` for Windows 8 apps). * * @memberOf _.support - * @type Boolean + * @type boolean */ - support.argsObject = arguments.constructor == Object && !(arguments instanceof Array); + support.funcDecomp = !isNative(context.WinRTError) && reThis.test(runInContext); /** - * Detect if an `arguments` object's [[Class]] is resolvable (all but Firefox < 4, IE < 9). + * Detect if `Function#name` is supported (all but IE). * * @memberOf _.support - * @type Boolean + * @type boolean */ - support.argsClass = isArguments(arguments); + support.funcNames = typeof Function.name == 'string'; /** - * Detect if `name` or `message` properties of `Error.prototype` are - * enumerable by default. (IE < 9, Safari < 5.1) + * Detect if the DOM is supported. * * @memberOf _.support - * @type Boolean - */ - support.enumErrorProps = propertyIsEnumerable.call(errorProto, 'message') || propertyIsEnumerable.call(errorProto, 'name'); - - /** - * Detect if `prototype` properties are enumerable by default. - * - * Firefox < 3.6, Opera > 9.50 - Opera < 11.60, and Safari < 5.1 - * (if the prototype or a property on the prototype has been set) - * incorrectly sets a function's `prototype` property [[Enumerable]] - * value to `true`. - * - * @memberOf _.support - * @type Boolean - */ - support.enumPrototypes = propertyIsEnumerable.call(ctor, 'prototype'); - - /** - * Detect if `Function#bind` exists and is inferred to be fast (all but V8). - * - * @memberOf _.support - * @type Boolean - */ - support.fastBind = nativeBind && !isV8; - - /** - * Detect if own properties are iterated after inherited properties (all but IE < 9). - * - * @memberOf _.support - * @type Boolean - */ - support.ownLast = props[0] != 'x'; - - /** - * Detect if `arguments` object indexes are non-enumerable - * (Firefox < 4, IE < 9, PhantomJS, Safari < 5.1). - * - * @memberOf _.support - * @type Boolean - */ - support.nonEnumArgs = prop != 0; - - /** - * Detect if properties shadowing those on `Object.prototype` are non-enumerable. - * - * In IE < 9 an objects own properties, shadowing non-enumerable ones, are - * made non-enumerable as well (a.k.a the JScript [[DontEnum]] bug). - * - * @memberOf _.support - * @type Boolean - */ - support.nonEnumShadows = !/valueOf/.test(props); - - /** - * Detect if `Array#shift` and `Array#splice` augment array-like objects correctly. - * - * Firefox < 10, IE compatibility mode, and IE < 9 have buggy Array `shift()` - * and `splice()` functions that fail to remove the last element, `value[0]`, - * of array-like objects even though the `length` property is set to `0`. - * The `shift()` method is buggy in IE 8 compatibility mode, while `splice()` - * is buggy regardless of mode in IE < 9 and buggy in compatibility mode in IE 9. - * - * @memberOf _.support - * @type Boolean - */ - support.spliceObjects = (arrayRef.splice.call(object, 0, 1), !object[0]); - - /** - * Detect lack of support for accessing string characters by index. - * - * IE < 8 can't access characters by index and IE 8 can only access - * characters by index on string literals. - * - * @memberOf _.support - * @type Boolean - */ - support.unindexedChars = ('x'[0] + Object('x')[0]) != 'xx'; - - /** - * Detect if a DOM node's [[Class]] is resolvable (all but IE < 9) - * and that the JS engine errors when attempting to coerce an object to - * a string without a `toString` function. - * - * @memberOf _.support - * @type Boolean + * @type boolean */ try { - support.nodeClass = !(toString.call(document) == objectClass && !({ 'toString': 0 } + '')); + support.dom = document.createDocumentFragment().nodeType === 11; } catch(e) { - support.nodeClass = true; + support.dom = false; } - }(1)); - /*--------------------------------------------------------------------------*/ + /** + * Detect if `arguments` object indexes are non-enumerable. + * + * In Firefox < 4, IE < 9, PhantomJS, and Safari < 5.1 `arguments` object + * indexes are non-enumerable. Chrome < 25 and Node.js < 0.11.0 treat + * `arguments` object indexes as non-enumerable and fail `hasOwnProperty` + * checks for indexes that exceed their function's formal parameters with + * associated values of `0`. + * + * @memberOf _.support + * @type boolean + */ + try { + support.nonEnumArgs = !propertyIsEnumerable.call(arguments, 1); + } catch(e) { + support.nonEnumArgs = true; + } + }(0, 0)); /** - * The template used to create iterator functions. + * By default, the template delimiters used by lodash are like those in + * embedded Ruby (ERB). Change the following template settings to use + * alternative delimiters. * - * @private - * @param {Object} data The data object used to populate the text. - * @returns {String} Returns the interpolated text. + * @static + * @memberOf _ + * @type Object */ - var iteratorTemplate = function(obj) { + lodash.templateSettings = { - var __p = 'var index, iterable = ' + - (obj.firstArg) + - ', result = ' + - (obj.init) + - ';\nif (!iterable) return result;\n' + - (obj.top) + - ';'; - if (obj.array) { - __p += '\nvar length = iterable.length; index = -1;\nif (' + - (obj.array) + - ') { '; - if (support.unindexedChars) { - __p += '\n if (isString(iterable)) {\n iterable = iterable.split(\'\')\n } '; - } - __p += '\n while (++index < length) {\n ' + - (obj.loop) + - ';\n }\n}\nelse { '; - } else if (support.nonEnumArgs) { - __p += '\n var length = iterable.length; index = -1;\n if (length && isArguments(iterable)) {\n while (++index < length) {\n index += \'\';\n ' + - (obj.loop) + - ';\n }\n } else { '; - } + /** + * Used to detect `data` property values to be HTML-escaped. + * + * @memberOf _.templateSettings + * @type RegExp + */ + 'escape': reEscape, - if (support.enumPrototypes) { - __p += '\n var skipProto = typeof iterable == \'function\';\n '; - } + /** + * Used to detect code to be evaluated. + * + * @memberOf _.templateSettings + * @type RegExp + */ + 'evaluate': reEvaluate, - if (support.enumErrorProps) { - __p += '\n var skipErrorProps = iterable === errorProto || iterable instanceof Error;\n '; - } + /** + * Used to detect `data` property values to inject. + * + * @memberOf _.templateSettings + * @type RegExp + */ + 'interpolate': reInterpolate, - var conditions = []; if (support.enumPrototypes) { conditions.push('!(skipProto && index == "prototype")'); } if (support.enumErrorProps) { conditions.push('!(skipErrorProps && (index == "message" || index == "name"))'); } + /** + * Used to reference the data object in the template text. + * + * @memberOf _.templateSettings + * @type string + */ + 'variable': '', - if (obj.useHas && obj.useKeys) { - __p += '\n var ownIndex = -1,\n ownProps = objectTypes[typeof iterable] && keys(iterable),\n length = ownProps ? ownProps.length : 0;\n\n while (++ownIndex < length) {\n index = ownProps[ownIndex];\n'; - if (conditions.length) { - __p += ' if (' + - (conditions.join(' && ')) + - ') {\n '; - } - __p += - (obj.loop) + - '; '; - if (conditions.length) { - __p += '\n }'; - } - __p += '\n } '; - } else { - __p += '\n for (index in iterable) {\n'; - if (obj.useHas) { conditions.push("hasOwnProperty.call(iterable, index)"); } if (conditions.length) { - __p += ' if (' + - (conditions.join(' && ')) + - ') {\n '; - } - __p += - (obj.loop) + - '; '; - if (conditions.length) { - __p += '\n }'; - } - __p += '\n } '; - if (support.nonEnumShadows) { - __p += '\n\n if (iterable !== objectProto) {\n var ctor = iterable.constructor,\n isProto = iterable === (ctor && ctor.prototype),\n className = iterable === stringProto ? stringClass : iterable === errorProto ? errorClass : toString.call(iterable),\n nonEnum = nonEnumProps[className];\n '; - for (k = 0; k < 7; k++) { - __p += '\n index = \'' + - (obj.shadowedProps[k]) + - '\';\n if ((!(isProto && nonEnum[index]) && hasOwnProperty.call(iterable, index))'; - if (!obj.useHas) { - __p += ' || (!nonEnum[index] && iterable[index] !== objectProto[index])'; - } - __p += ') {\n ' + - (obj.loop) + - ';\n } '; - } - __p += '\n } '; - } + /** + * Used to import variables into the compiled template. + * + * @memberOf _.templateSettings + * @type Object + */ + 'imports': { - } - - if (obj.array || support.nonEnumArgs) { - __p += '\n}'; - } - __p += - (obj.bottom) + - ';\nreturn result'; - - return __p + /** + * A reference to the `lodash` function. + * + * @memberOf _.templateSettings.imports + * @type Function + */ + '_': lodash + } }; - /** Reusable iterator options for `assign` and `defaults` */ - var defaultsIteratorOptions = { - 'args': 'object, source, guard', - 'top': - 'var args = arguments,\n' + - ' argsIndex = 0,\n' + - " argsLength = typeof guard == 'number' ? 2 : args.length;\n" + - 'while (++argsIndex < argsLength) {\n' + - ' iterable = args[argsIndex];\n' + - ' if (iterable && objectTypes[typeof iterable]) {', - 'loop': "if (typeof result[index] == 'undefined') result[index] = iterable[index]", - 'bottom': ' }\n}' - }; - - /** Reusable iterator options shared by `each`, `forIn`, and `forOwn` */ - var eachIteratorOptions = { - 'args': 'collection, callback, thisArg', - 'top': "callback = callback && typeof thisArg == 'undefined' ? callback : lodash.createCallback(callback, thisArg)", - 'array': "typeof length == 'number'", - 'loop': 'if (callback(iterable[index], index, collection) === false) return result' - }; - - /** Reusable iterator options for `forIn` and `forOwn` */ - var forOwnIteratorOptions = { - 'top': 'if (!objectTypes[typeof iterable]) return result;\n' + eachIteratorOptions.top, - 'array': false - }; - - /*--------------------------------------------------------------------------*/ + /*------------------------------------------------------------------------*/ /** - * Creates a function that, when called, invokes `func` with the `this` binding - * of `thisArg` and prepends any `partialArgs` to the arguments passed to the - * bound function. + * Creates a lazy wrapper object which wraps `value` to enable lazy evaluation. * * @private - * @param {Function|String} func The function to bind or the method name. - * @param {Mixed} [thisArg] The `this` binding of `func`. - * @param {Array} partialArgs An array of arguments to be partially applied. - * @param {Object} [idicator] Used to indicate binding by key or partially - * applying arguments from the right. - * @returns {Function} Returns the new bound function. + * @param {*} value The value to wrap. */ - function createBound(func, thisArg, partialArgs, indicator) { - var isFunc = isFunction(func), - isPartial = !partialArgs, - key = thisArg; - - // juggle arguments - if (isPartial) { - var rightIndicator = indicator; - partialArgs = thisArg; - } - else if (!isFunc) { - if (!indicator) { - throw new TypeError; - } - thisArg = func; - } - - function bound() { - // `Function#bind` spec - // http://es5.github.com/#x15.3.4.5 - var args = arguments, - thisBinding = isPartial ? this : thisArg; - - if (!isFunc) { - func = thisArg[key]; - } - if (partialArgs.length) { - args = args.length - ? (args = nativeSlice.call(args), rightIndicator ? args.concat(partialArgs) : partialArgs.concat(args)) - : partialArgs; - } - if (this instanceof bound) { - // ensure `new bound` is an instance of `func` - thisBinding = createObject(func.prototype); - - // mimic the constructor's `return` behavior - // http://es5.github.com/#x13.2.2 - var result = func.apply(thisBinding, args); - return isObject(result) ? result : thisBinding; - } - return func.apply(thisBinding, args); - } - return bound; + function LazyWrapper(value) { + this.actions = null; + this.dir = 1; + this.dropCount = 0; + this.filtered = false; + this.iteratees = null; + this.takeCount = POSITIVE_INFINITY; + this.views = null; + this.wrapped = value; } /** - * Creates compiled iteration functions. + * Creates a clone of the lazy wrapper object. * * @private - * @param {Object} [options1, options2, ...] The compile options object(s). - * array - A string of code to determine if the iterable is an array or array-like. - * useHas - A boolean to specify using `hasOwnProperty` checks in the object loop. - * useKeys - A boolean to specify using `_.keys` for own property iteration. - * args - A string of comma separated arguments the iteration function will accept. - * top - A string of code to execute before the iteration branches. - * loop - A string of code to execute in the object loop. - * bottom - A string of code to execute after the iteration branches. - * @returns {Function} Returns the compiled function. + * @name clone + * @memberOf LazyWrapper + * @returns {Object} Returns the cloned `LazyWrapper` object. */ - function createIterator() { - var data = getObject(); + function lazyClone() { + var actions = this.actions, + iteratees = this.iteratees, + views = this.views, + result = new LazyWrapper(this.wrapped); - // data properties - data.shadowedProps = shadowedProps; - // iterator options - data.array = data.bottom = data.loop = data.top = ''; - data.init = 'iterable'; - data.useHas = true; - data.useKeys = !!keys; - - // merge options into a template data object - for (var object, index = 0; object = arguments[index]; index++) { - for (var key in object) { - data[key] = object[key]; - } - } - var args = data.args; - data.firstArg = /^[^,]+/.exec(args)[0]; - - // create the function factory - var factory = Function( - 'errorClass, errorProto, hasOwnProperty, isArguments, isArray, ' + - 'isString, keys, lodash, objectProto, objectTypes, nonEnumProps, ' + - 'stringClass, stringProto, toString', - 'return function(' + args + ') {\n' + iteratorTemplate(data) + '\n}' - ); - - releaseObject(data); - - // return the compiled function - return factory( - errorClass, errorProto, hasOwnProperty, isArguments, isArray, - isString, keys, lodash, objectProto, objectTypes, nonEnumProps, - stringClass, stringProto, toString - ); - } - - /** - * Creates a new object with the specified `prototype`. - * - * @private - * @param {Object} prototype The prototype object. - * @returns {Object} Returns the new object. - */ - function createObject(prototype) { - return isObject(prototype) ? nativeCreate(prototype) : {}; - } - // fallback for browsers without `Object.create` - if (!nativeCreate) { - var createObject = function(prototype) { - if (isObject(prototype)) { - noop.prototype = prototype; - var result = new noop; - noop.prototype = null; - } - return result || {}; - }; - } - - /** - * Used by `escape` to convert characters to HTML entities. - * - * @private - * @param {String} match The matched character to escape. - * @returns {String} Returns the escaped character. - */ - function escapeHtmlChar(match) { - return htmlEscapes[match]; - } - - /** - * Gets the appropriate "indexOf" function. If the `_.indexOf` method is - * customized, this method returns the custom method, otherwise it returns - * the `basicIndexOf` function. - * - * @private - * @returns {Function} Returns the "indexOf" function. - */ - function getIndexOf(array, value, fromIndex) { - var result = (result = lodash.indexOf) === indexOf ? basicIndexOf : result; + result.actions = actions ? arrayCopy(actions) : null; + result.dir = this.dir; + result.dropCount = this.dropCount; + result.filtered = this.filtered; + result.iteratees = iteratees ? arrayCopy(iteratees) : null; + result.takeCount = this.takeCount; + result.views = views ? arrayCopy(views) : null; return result; } /** - * Creates a function that juggles arguments, allowing argument overloading - * for `_.flatten` and `_.uniq`, before passing them to the given `func`. + * Reverses the direction of lazy iteration. * * @private - * @param {Function} func The function to wrap. - * @returns {Function} Returns the new function. + * @name reverse + * @memberOf LazyWrapper + * @returns {Object} Returns the new reversed `LazyWrapper` object. */ - function overloadWrapper(func) { - return function(array, flag, callback, thisArg) { - // juggle arguments - if (typeof flag != 'boolean' && flag != null) { - thisArg = callback; - callback = !(thisArg && thisArg[flag] === array) ? flag : undefined; - flag = false; - } - if (callback != null) { - callback = lodash.createCallback(callback, thisArg); - } - return func(array, flag, callback, thisArg); - }; + function lazyReverse() { + if (this.filtered) { + var result = new LazyWrapper(this); + result.dir = -1; + result.filtered = true; + } else { + result = this.clone(); + result.dir *= -1; + } + return result; } /** - * 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. + * Extracts the unwrapped value from its lazy wrapper. * * @private - * @param {Mixed} value The value to check. - * @returns {Boolean} Returns `true`, if `value` is a plain object, else `false`. + * @name value + * @memberOf LazyWrapper + * @returns {*} Returns the unwrapped value. */ - 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)) || - (!support.argsClass && isArguments(value)) || - (!support.nodeClass && isNode(value))) { - return false; + function lazyValue() { + var array = this.wrapped.value(); + if (!isArray(array)) { + return baseWrapperValue(array, this.actions); } - // IE < 9 iterates inherited properties before own properties. If the first - // iterated property is an object's own property then there are no inherited - // enumerable properties. - if (support.ownLast) { - forIn(value, function(value, key, object) { - result = hasOwnProperty.call(object, key); + var dir = this.dir, + isRight = dir < 0, + view = getView(0, array.length, this.views), + start = view.start, + end = view.end, + length = end - start, + dropCount = this.dropCount, + takeCount = nativeMin(length, this.takeCount - dropCount), + index = isRight ? end : start - 1, + iteratees = this.iteratees, + iterLength = iteratees ? iteratees.length : 0, + resIndex = 0, + result = []; + + outer: + while (length-- && resIndex < takeCount) { + index += dir; + + var iterIndex = -1, + value = array[index]; + + while (++iterIndex < iterLength) { + var data = iteratees[iterIndex], + iteratee = data.iteratee, + computed = iteratee(value, index, array), + type = data.type; + + if (type == LAZY_MAP_FLAG) { + value = computed; + } else if (!computed) { + if (type == LAZY_FILTER_FLAG) { + continue outer; + } else { + break outer; + } + } + } + if (dropCount) { + dropCount--; + } else { + result[resIndex++] = value; + } + } + return result; + } + + /*------------------------------------------------------------------------*/ + + /** + * Creates a cache object to store key/value pairs. + * + * @private + * @static + * @name Cache + * @memberOf _.memoize + */ + function MapCache() { + this.__data__ = {}; + } + + /** + * Removes `key` and its value from the cache. + * + * @private + * @name delete + * @memberOf _.memoize.Cache + * @param {string} key The key of the value to remove. + * @returns {boolean} Returns `true` if the entry was removed successfully, else `false`. + */ + function mapDelete(key) { + return this.has(key) && delete this.__data__[key]; + } + + /** + * Gets the cached value for `key`. + * + * @private + * @name get + * @memberOf _.memoize.Cache + * @param {string} key The key of the value to get. + * @returns {*} Returns the cached value. + */ + function mapGet(key) { + return key == '__proto__' ? undefined : this.__data__[key]; + } + + /** + * Checks if a cached value for `key` exists. + * + * @private + * @name has + * @memberOf _.memoize.Cache + * @param {string} key The key of the entry to check. + * @returns {boolean} Returns `true` if an entry for `key` exists, else `false`. + */ + function mapHas(key) { + return key != '__proto__' && hasOwnProperty.call(this.__data__, key); + } + + /** + * Adds `value` to `key` of the cache. + * + * @private + * @name set + * @memberOf _.memoize.Cache + * @param {string} key The key of the value to cache. + * @param {*} value The value to cache. + * @returns {Object} Returns the cache object. + */ + function mapSet(key, value) { + if (key != '__proto__') { + this.__data__[key] = value; + } + return this; + } + + /*------------------------------------------------------------------------*/ + + /** + * + * Creates a cache object to store unique values. + * + * @private + * @param {Array} [values] The values to cache. + */ + function SetCache(values) { + var length = values ? values.length : 0; + + this.data = { 'hash': nativeCreate(null), 'set': new Set }; + while (length--) { + this.push(values[length]); + } + } + + /** + * Checks if `value` is in `cache` mimicking the return signature of + * `_.indexOf` by returning `0` if the value is found, else `-1`. + * + * @private + * @param {Object} cache The cache to search. + * @param {*} value The value to search for. + * @returns {number} Returns `0` if `value` is found, else `-1`. + */ + function cacheIndexOf(cache, value) { + var data = cache.data, + result = (typeof value == 'string' || isObject(value)) ? data.set.has(value) : data.hash[value]; + + return result ? 0 : -1; + } + + /** + * Adds `value` to the cache. + * + * @private + * @name push + * @memberOf SetCache + * @param {*} value The value to cache. + */ + function cachePush(value) { + var data = this.data; + if (typeof value == 'string' || isObject(value)) { + data.set.add(value); + } else { + data.hash[value] = true; + } + } + + /*------------------------------------------------------------------------*/ + + /** + * Copies the values of `source` to `array`. + * + * @private + * @param {Array} source The array to copy values from. + * @param {Array} [array=[]] The array to copy values to. + * @returns {Array} Returns `array`. + */ + function arrayCopy(source, array) { + var index = -1, + length = source.length; + + array || (array = Array(length)); + while (++index < length) { + array[index] = source[index]; + } + return array; + } + + /** + * A specialized version of `_.forEach` for arrays without support for callback + * shorthands or `this` binding. + * + * @private + * @param {Array} array The array to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @returns {Array} Returns `array`. + */ + function arrayEach(array, iteratee) { + var index = -1, + length = array.length; + + while (++index < length) { + if (iteratee(array[index], index, array) === false) { + break; + } + } + return array; + } + + /** + * A specialized version of `_.forEachRight` for arrays without support for + * callback shorthands or `this` binding. + * + * @private + * @param {Array} array The array to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @returns {Array} Returns `array`. + */ + function arrayEachRight(array, iteratee) { + var length = array.length; + + while (length--) { + if (iteratee(array[length], length, array) === false) { + break; + } + } + return array; + } + + /** + * A specialized version of `_.every` for arrays without support for callback + * shorthands or `this` binding. + * + * @private + * @param {Array} array The array to iterate over. + * @param {Function} predicate The function invoked per iteration. + * @returns {boolean} Returns `true` if all elements pass the predicate check, + * else `false`. + */ + function arrayEvery(array, predicate) { + var index = -1, + length = array.length; + + while (++index < length) { + if (!predicate(array[index], index, array)) { return false; - }); - return result !== 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 result === undefined || hasOwnProperty.call(value, result); + return true; } /** - * Used by `unescape` to convert HTML entities to characters. + * A specialized version of `_.filter` for arrays without support for callback + * shorthands or `this` binding. * * @private - * @param {String} match The matched character to unescape. - * @returns {String} Returns the unescaped character. + * @param {Array} array The array to iterate over. + * @param {Function} predicate The function invoked per iteration. + * @returns {Array} Returns the new filtered array. */ - function unescapeHtmlChar(match) { - return htmlUnescapes[match]; - } + function arrayFilter(array, predicate) { + var index = -1, + length = array.length, + resIndex = -1, + result = []; - /*--------------------------------------------------------------------------*/ - - /** - * Checks if `value` is an `arguments` object. - * - * @static - * @memberOf _ - * @category Objects - * @param {Mixed} value The value to check. - * @returns {Boolean} Returns `true`, if the `value` is an `arguments` object, else `false`. - * @example - * - * (function() { return _.isArguments(arguments); })(1, 2, 3); - * // => true - * - * _.isArguments([1, 2, 3]); - * // => false - */ - function isArguments(value) { - return toString.call(value) == argsClass; - } - // fallback for browsers that can't detect `arguments` objects by [[Class]] - if (!support.argsClass) { - isArguments = function(value) { - return value ? hasOwnProperty.call(value, 'callee') : false; - }; + while (++index < length) { + var value = array[index]; + if (predicate(value, index, array)) { + result[++resIndex] = value; + } + } + return result; } /** - * Checks if `value` is an array. - * - * @static - * @memberOf _ - * @category Objects - * @param {Mixed} value The value to check. - * @returns {Boolean} Returns `true`, if the `value` is an array, else `false`. - * @example - * - * (function() { return _.isArray(arguments); })(); - * // => false - * - * _.isArray([1, 2, 3]); - * // => true - */ - var isArray = nativeIsArray || function(value) { - return value ? (typeof value == 'object' && toString.call(value) == arrayClass) : false; - }; - - /** - * A fallback implementation of `Object.keys` which produces an array of the - * given object's own enumerable property names. + * A specialized version of `_.map` for arrays without support for callback + * shorthands or `this` binding. * * @private - * @type Function - * @param {Object} object The object to inspect. - * @returns {Array} Returns a new array of property names. + * @param {Array} array The array to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @returns {Array} Returns the new mapped array. */ - var shimKeys = createIterator({ - 'args': 'object', - 'init': '[]', - 'top': 'if (!(objectTypes[typeof object])) return result', - 'loop': 'result.push(index)' - }); + function arrayMap(array, iteratee) { + var index = -1, + length = array.length, + result = Array(length); + + while (++index < length) { + result[index] = iteratee(array[index], index, array); + } + return result; + } /** - * Creates an array composed of the own enumerable property names of `object`. - * - * @static - * @memberOf _ - * @category Objects - * @param {Object} object The object to inspect. - * @returns {Array} Returns a new array of property names. - * @example - * - * _.keys({ 'one': 1, 'two': 2, 'three': 3 }); - * // => ['one', 'two', 'three'] (order is not guaranteed) - */ - var keys = !nativeKeys ? shimKeys : function(object) { - if (!isObject(object)) { - return []; - } - if ((support.enumPrototypes && typeof object == 'function') || - (support.nonEnumArgs && object.length && isArguments(object))) { - return shimKeys(object); - } - return nativeKeys(object); - }; - - /** - * A function compiled to iterate `arguments` objects, arrays, objects, and - * strings consistenly across environments, executing the `callback` for each - * element in the `collection`. The `callback` is bound to `thisArg` and invoked - * with three arguments; (value, index|key, collection). Callbacks may exit - * iteration early by explicitly returning `false`. + * A specialized version of `_.max` for arrays without support for iteratees. * * @private - * @type Function - * @param {Array|Object|String} collection The collection to iterate over. - * @param {Function} [callback=identity] The function called per iteration. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Array|Object|String} Returns `collection`. + * @param {Array} array The array to iterate over. + * @returns {*} Returns the maximum value. */ - var basicEach = createIterator(eachIteratorOptions); + function arrayMax(array) { + var index = -1, + length = array.length, + result = NEGATIVE_INFINITY; + + while (++index < length) { + var value = array[index]; + if (value > result) { + result = value; + } + } + return result; + } /** - * Used to convert characters to HTML entities: + * A specialized version of `_.min` for arrays without support for iteratees. * - * 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") + * @private + * @param {Array} array The array to iterate over. + * @returns {*} Returns the minimum value. */ - var htmlEscapes = { - '&': '&', - '<': '<', - '>': '>', - '"': '"', - "'": ''' - }; + function arrayMin(array) { + var index = -1, + length = array.length, + result = POSITIVE_INFINITY; - /** Used to convert HTML entities to characters */ - var htmlUnescapes = invert(htmlEscapes); - - /*--------------------------------------------------------------------------*/ + while (++index < length) { + var value = array[index]; + if (value < result) { + result = value; + } + } + return result; + } /** - * Assigns own enumerable properties of source object(s) to the destination - * object. Subsequent sources will overwrite property assignments of previous - * sources. If a `callback` function is passed, it will be executed to produce - * the assigned values. The `callback` is bound to `thisArg` and invoked with - * two arguments; (objectValue, sourceValue). + * A specialized version of `_.reduce` for arrays without support for callback + * shorthands or `this` binding. * - * @static - * @memberOf _ - * @type Function - * @alias extend - * @category Objects + * @private + * @param {Array} array The array to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @param {*} [accumulator] The initial value. + * @param {boolean} [initFromArray] Specify using the first element of `array` + * as the initial value. + * @returns {*} Returns the accumulated value. + */ + function arrayReduce(array, iteratee, accumulator, initFromArray) { + var index = -1, + length = array.length; + + if (initFromArray && length) { + accumulator = array[++index]; + } + while (++index < length) { + accumulator = iteratee(accumulator, array[index], index, array); + } + return accumulator; + } + + /** + * A specialized version of `_.reduceRight` for arrays without support for + * callback shorthands or `this` binding. + * + * @private + * @param {Array} array The array to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @param {*} [accumulator] The initial value. + * @param {boolean} [initFromArray] Specify using the last element of `array` + * as the initial value. + * @returns {*} Returns the accumulated value. + */ + function arrayReduceRight(array, iteratee, accumulator, initFromArray) { + var length = array.length; + if (initFromArray && length) { + accumulator = array[--length]; + } + while (length--) { + accumulator = iteratee(accumulator, array[length], length, array); + } + return accumulator; + } + + /** + * A specialized version of `_.some` for arrays without support for callback + * shorthands or `this` binding. + * + * @private + * @param {Array} array The array to iterate over. + * @param {Function} predicate The function invoked per iteration. + * @returns {boolean} Returns `true` if any element passes the predicate check, + * else `false`. + */ + function arraySome(array, predicate) { + var index = -1, + length = array.length; + + while (++index < length) { + if (predicate(array[index], index, array)) { + return true; + } + } + return false; + } + + /** + * Used by `_.defaults` to customize its `_.assign` use. + * + * @private + * @param {*} objectValue The destination object property value. + * @param {*} sourceValue The source object property value. + * @returns {*} Returns the value to assign to the destination object. + */ + function assignDefaults(objectValue, sourceValue) { + return typeof objectValue == 'undefined' ? sourceValue : objectValue; + } + + /** + * Used by `_.template` to customize its `_.assign` use. + * + * **Note:** This method is like `assignDefaults` except that it ignores + * inherited property values when checking if a property is `undefined`. + * + * @private + * @param {*} objectValue The destination object property value. + * @param {*} sourceValue The source object property value. + * @param {string} key The key associated with the object and source values. * @param {Object} object The destination object. - * @param {Object} [source1, source2, ...] The source objects. - * @param {Function} [callback] The function to customize assigning values. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Object} Returns the destination object. - * @example - * - * _.assign({ 'name': 'moe' }, { 'age': 40 }); - * // => { 'name': 'moe', 'age': 40 } - * - * var defaults = _.partialRight(_.assign, function(a, b) { - * return typeof a == 'undefined' ? b : a; - * }); - * - * var food = { 'name': 'apple' }; - * defaults(food, { 'name': 'banana', 'type': 'fruit' }); - * // => { 'name': 'apple', 'type': 'fruit' } + * @returns {*} Returns the value to assign to the destination object. */ - var assign = createIterator(defaultsIteratorOptions, { - 'top': - defaultsIteratorOptions.top.replace(';', - ';\n' + - "if (argsLength > 3 && typeof args[argsLength - 2] == 'function') {\n" + - ' var callback = lodash.createCallback(args[--argsLength - 1], args[argsLength--], 2);\n' + - "} else if (argsLength > 2 && typeof args[argsLength - 1] == 'function') {\n" + - ' callback = args[--argsLength];\n' + - '}' - ), - 'loop': 'result[index] = callback ? callback(result[index], iterable[index]) : iterable[index]' - }); + function assignOwnDefaults(objectValue, sourceValue, key, object) { + return (typeof objectValue == 'undefined' || !hasOwnProperty.call(object, key)) + ? sourceValue + : objectValue; + } /** - * Creates a clone of `value`. If `deep` is `true`, nested objects will also - * be cloned, otherwise they will be assigned by reference. If a `callback` - * function is passed, it will be executed to produce the cloned values. If - * `callback` returns `undefined`, cloning will be handled by the method instead. - * The `callback` is bound to `thisArg` and invoked with one argument; (value). + * The base implementation of `_.assign` without support for argument juggling, + * multiple sources, and `this` binding `customizer` functions. * - * @static - * @memberOf _ - * @category Objects - * @param {Mixed} value The value to clone. - * @param {Boolean} [deep=false] A flag to indicate a deep clone. - * @param {Function} [callback] The function to customize cloning values. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @param- {Array} [stackA=[]] Tracks traversed source objects. - * @param- {Array} [stackB=[]] Associates clones with source counterparts. - * @returns {Mixed} Returns the cloned `value`. - * @example - * - * var stooges = [ - * { 'name': 'moe', 'age': 40 }, - * { 'name': 'larry', 'age': 50 } - * ]; - * - * var shallow = _.clone(stooges); - * shallow[0] === stooges[0]; - * // => true - * - * var deep = _.clone(stooges, true); - * deep[0] === stooges[0]; - * // => false - * - * _.mixin({ - * 'clone': _.partialRight(_.clone, function(value) { - * return _.isElement(value) ? value.cloneNode(false) : undefined; - * }) - * }); - * - * var clone = _.clone(document.body); - * clone.childNodes.length; - * // => 0 + * @private + * @param {Object} object The destination object. + * @param {Object} source The source object. + * @param {Function} [customizer] The function to customize assigning values. + * @returns {Object} Returns the destination object. */ - function clone(value, deep, callback, thisArg, stackA, stackB) { - var result = value; - - // allows working with "Collections" methods without using their `callback` - // argument, `index|key`, for this method's `callback` - if (typeof deep != 'boolean' && deep != null) { - thisArg = callback; - callback = deep; - deep = false; + function baseAssign(object, source, customizer) { + var props = keys(source); + if (!customizer) { + return baseCopy(source, object, props); } - if (typeof callback == 'function') { - callback = (typeof thisArg == 'undefined') - ? callback - : lodash.createCallback(callback, thisArg, 1); + var index = -1, + length = props.length - result = callback(result); - if (typeof result != 'undefined') { - return result; + while (++index < length) { + var key = props[index], + value = object[key], + result = customizer(value, source[key], key, object, source); + + if ((result === result ? result !== value : value === value) || + (typeof value == 'undefined' && !(key in object))) { + object[key] = result; } - result = value; } - // inspect [[Class]] - var isObj = isObject(result); - if (isObj) { - var className = toString.call(result); - if (!cloneableClasses[className] || (!support.nodeClass && isNode(result))) { - return result; + return object; + } + + /** + * The base implementation of `_.at` without support for strings and individual + * key arguments. + * + * @private + * @param {Array|Object} collection The collection to iterate over. + * @param {number[]|string[]} [props] The property names or indexes of elements to pick. + * @returns {Array} Returns the new array of picked elements. + */ + function baseAt(collection, props) { + var index = -1, + length = collection.length, + isArr = isLength(length), + propsLength = props.length, + result = Array(propsLength); + + while(++index < propsLength) { + var key = props[index]; + if (isArr) { + key = parseFloat(key); + result[index] = isIndex(key, length) ? collection[key] : undefined; + } else { + result[index] = collection[key]; } - var isArr = isArray(result); } - // shallow clone - if (!isObj || !deep) { - return isObj - ? (isArr ? slice(result) : assign({}, result)) - : result; - } - var ctor = ctorByClass[className]; - switch (className) { - case boolClass: - case dateClass: - return new ctor(+result); + return result; + } - case numberClass: - case stringClass: - return new ctor(result); - - case regexpClass: - return ctor(result.source, reFlags.exec(result)); + /** + * Copies the properties of `source` to `object`. + * + * @private + * @param {Object} source The object to copy properties from. + * @param {Object} [object={}] The object to copy properties to. + * @param {Array} props The property names to copy. + * @returns {Object} Returns `object`. + */ + function baseCopy(source, object, props) { + if (!props) { + props = object; + object = {}; } - // check for circular references and return corresponding clone - var initedStack = !stackA; - stackA || (stackA = getArray()); - stackB || (stackB = getArray()); + var index = -1, + length = props.length; + + while (++index < length) { + var key = props[index]; + object[key] = source[key]; + } + return object; + } + + /** + * The base implementation of `_.bindAll` without support for individual + * method name arguments. + * + * @private + * @param {Object} object The object to bind and assign the bound methods to. + * @param {string[]} methodNames The object method names to bind. + * @returns {Object} Returns `object`. + */ + function baseBindAll(object, methodNames) { + var index = -1, + length = methodNames.length; + + while (++index < length) { + var key = methodNames[index]; + object[key] = createWrapper(object[key], BIND_FLAG, object); + } + return object; + } + + /** + * The base implementation of `_.callback` which supports specifying the + * number of arguments to provide to `func`. + * + * @private + * @param {*} [func=_.identity] The value to convert to a callback. + * @param {*} [thisArg] The `this` binding of `func`. + * @param {number} [argCount] The number of arguments to provide to `func`. + * @returns {Function} Returns the callback. + */ + function baseCallback(func, thisArg, argCount) { + var type = typeof func; + if (type == 'function') { + return (typeof thisArg != 'undefined' && isBindable(func)) + ? bindCallback(func, thisArg, argCount) + : func; + } + if (func == null) { + return identity; + } + // Handle "_.property" and "_.matches" style callback shorthands. + return type == 'object' + ? baseMatches(func, !argCount) + : baseProperty(func + ''); + } + + /** + * The base implementation of `_.clone` without support for argument juggling + * and `this` binding `customizer` functions. + * + * @private + * @param {*} value The value to clone. + * @param {boolean} [isDeep] Specify a deep clone. + * @param {Function} [customizer] The function to customize cloning values. + * @param {string} [key] The key of `value`. + * @param {Object} [object] The object `value` belongs to. + * @param {Array} [stackA=[]] Tracks traversed source objects. + * @param {Array} [stackB=[]] Associates clones with source counterparts. + * @returns {*} Returns the cloned value. + */ + function baseClone(value, isDeep, customizer, key, object, stackA, stackB) { + var result; + if (customizer) { + result = object ? customizer(value, key, object) : customizer(value); + } + if (typeof result != 'undefined') { + return result; + } + if (!isObject(value)) { + return value; + } + var isArr = isArray(value); + if (isArr) { + result = initCloneArray(value); + if (!isDeep) { + return arrayCopy(value, result); + } + } else { + var tag = objToString.call(value), + isFunc = tag == funcTag; + + if (tag == objectTag || tag == argsTag || (isFunc && !object)) { + result = initCloneObject(isFunc ? {} : value); + if (!isDeep) { + return baseCopy(value, result, keys(value)); + } + } else { + return cloneableTags[tag] + ? initCloneByTag(value, tag, isDeep) + : (object ? value : {}); + } + } + // Check for circular references and return corresponding clone. + stackA || (stackA = []); + stackB || (stackB = []); var length = stackA.length; while (length--) { @@ -1394,128 +1707,205 @@ return stackB[length]; } } - // init cloned object - result = isArr ? ctor(result.length) : {}; - - // 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; - } - } - // add the source value to the stack of traversed objects - // and associate it with its clone + // 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 ? basicEach : forOwn)(value, function(objValue, key) { - result[key] = clone(objValue, deep, callback, undefined, stackA, stackB); + // Recursively populate clone (susceptible to call stack limits). + (isArr ? arrayEach : baseForOwn)(value, function(subValue, key) { + result[key] = baseClone(subValue, isDeep, customizer, key, value, stackA, stackB); }); + return result; + } - if (initedStack) { - releaseArray(stackA); - releaseArray(stackB); + /** + * 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. + */ + var 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 `_.delay` and `_.defer` which accepts an index + * of where to slice the arguments to provide to `func`. + * + * @private + * @param {Function} func The function to delay. + * @param {number} wait The number of milliseconds to delay invocation. + * @param {Object} args The `arguments` object to slice and provide to `func`. + * @returns {number} Returns the timer id. + */ + function baseDelay(func, wait, args, fromIndex) { + if (!isFunction(func)) { + throw new TypeError(FUNC_ERROR_TEXT); + } + return setTimeout(function() { func.apply(undefined, baseSlice(args, fromIndex)); }, wait); + } + + /** + * The base implementation of `_.difference` which accepts a single array + * of values to exclude. + * + * @private + * @param {Array} array The array to inspect. + * @param {Array} values The values to exclude. + * @returns {Array} Returns the new array of filtered values. + */ + function baseDifference(array, values) { + var length = array ? array.length : 0, + result = []; + + if (!length) { + return result; + } + var index = -1, + indexOf = getIndexOf(), + isCommon = indexOf == baseIndexOf, + cache = isCommon && values.length >= 200 && createCache(values), + valuesLength = values.length; + + if (cache) { + indexOf = cacheIndexOf; + isCommon = false; + values = cache; + } + outer: + while (++index < length) { + var value = array[index]; + + if (isCommon && value === value) { + var valuesIndex = valuesLength; + while (valuesIndex--) { + if (values[valuesIndex] === value) { + continue outer; + } + } + result.push(value); + } + else if (indexOf(values, value) < 0) { + result.push(value); + } } return result; } /** - * Creates a deep clone of `value`. If a `callback` function is passed, - * it will be executed to produce the cloned values. If `callback` returns - * `undefined`, cloning will be handled by the method instead. The `callback` - * is bound to `thisArg` and invoked with one argument; (value). + * The base implementation of `_.forEach` without support for callback + * shorthands and `this` binding. * - * 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 {Mixed} value The value to deep clone. - * @param {Function} [callback] The function to customize cloning values. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Mixed} Returns the deep cloned `value`. - * @example - * - * var stooges = [ - * { 'name': 'moe', 'age': 40 }, - * { 'name': 'larry', 'age': 50 } - * ]; - * - * var deep = _.cloneDeep(stooges); - * deep[0] === stooges[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 + * @private + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @returns {Array|Object|string} Returns `collection`. */ - function cloneDeep(value, callback, thisArg) { - return clone(value, true, callback, thisArg); + function baseEach(collection, iteratee) { + var length = collection ? collection.length : 0; + if (!isLength(length)) { + return baseForOwn(collection, iteratee); + } + var index = -1, + iterable = toObject(collection); + + while (++index < length) { + if (iteratee(iterable[index], index, iterable) === false) { + break; + } + } + return collection; } /** - * 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. + * The base implementation of `_.forEachRight` without support for callback + * shorthands and `this` binding. * - * @static - * @memberOf _ - * @type Function - * @category Objects - * @param {Object} object The destination object. - * @param {Object} [source1, source2, ...] The source objects. - * @param- {Object} [guard] Allows working with `_.reduce` without using its - * callback's `key` and `object` arguments as sources. - * @returns {Object} Returns the destination object. - * @example - * - * var food = { 'name': 'apple' }; - * _.defaults(food, { 'name': 'banana', 'type': 'fruit' }); - * // => { 'name': 'apple', 'type': 'fruit' } + * @private + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @returns {Array|Object|string} Returns `collection`. */ - var defaults = createIterator(defaultsIteratorOptions); + function baseEachRight(collection, iteratee) { + var length = collection ? collection.length : 0; + if (!isLength(length)) { + return baseForOwnRight(collection, iteratee); + } + var iterable = toObject(collection); + while (length--) { + if (iteratee(iterable[length], length, iterable) === false) { + break; + } + } + return collection; + } /** - * This method is similar to `_.find`, except that it returns the key of the - * element that passes the callback check, instead of the element itself. + * The base implementation of `_.every` without support for callback + * shorthands or `this` binding. * - * @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 passed, it will be used to create - * a "_.pluck" or "_.where" style callback, respectively. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Mixed} Returns the key of the found element, else `undefined`. - * @example - * - * _.findKey({ 'a': 1, 'b': 2, 'c': 3, 'd': 4 }, function(num) { - * return num % 2 == 0; - * }); - * // => 'b' + * @private + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} predicate The function invoked per iteration. + * @returns {boolean} Returns `true` if all elements pass the predicate check, + * else `false` */ - function findKey(object, callback, thisArg) { + function baseEvery(collection, predicate) { + var result = true; + baseEach(collection, function(value, index, collection) { + result = !!predicate(value, index, collection); + return result; + }); + return result; + } + + /** + * The base implementation of `_.filter` without support for callback + * shorthands or `this` binding. + * + * @private + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} predicate The function invoked per iteration. + * @returns {Array} Returns the new filtered array. + */ + function baseFilter(collection, predicate) { + var result = []; + baseEach(collection, function(value, index, collection) { + if (predicate(value, index, collection)) { + result.push(value); + } + }); + return result; + } + + /** + * The base implementation of `_.find`, `_.findLast`, `_.findKey`, and `_.findLastKey`, + * without support for callback shorthands and `this` binding, which iterates + * over `collection` using the provided `eachFunc`. + * + * @private + * @param {Array|Object|string} collection The collection to search. + * @param {Function} predicate The function invoked per iteration. + * @param {Function} eachFunc The function to iterate over `collection`. + * @param {boolean} [retKey] Specify returning the key of the found element + * instead of the element itself. + * @returns {*} Returns the found element or its key, else `undefined`. + */ + function baseFind(collection, predicate, eachFunc, retKey) { var result; - callback = lodash.createCallback(callback, thisArg); - forOwn(object, function(value, key, object) { - if (callback(value, key, object)) { - result = key; + eachFunc(collection, function(value, key, collection) { + if (predicate(value, key, collection)) { + result = retKey ? key : value; return false; } }); @@ -1523,163 +1913,5679 @@ } /** - * Iterates over `object`'s own and inherited enumerable properties, executing - * the `callback` for each property. The `callback` is bound to `thisArg` and - * invoked with three arguments; (value, key, object). Callbacks may exit iteration - * early by explicitly returning `false`. + * The base implementation of `_.flatten` with added support for restricting + * flattening and specifying the start index. * - * @static - * @memberOf _ - * @type Function - * @category Objects - * @param {Object} object The object to iterate over. - * @param {Function} [callback=identity] The function called per iteration. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Object} Returns `object`. - * @example - * - * function Dog(name) { - * this.name = name; - * } - * - * Dog.prototype.bark = function() { - * alert('Woof, woof!'); - * }; - * - * _.forIn(new Dog('Dagny'), function(value, key) { - * alert(key); - * }); - * // => alerts 'name' and 'bark' (order is not guaranteed) + * @private + * @param {Array} array The array to flatten. + * @param {boolean} [isDeep] Specify a deep flatten. + * @param {boolean} [isStrict] Restrict flattening to arrays and `arguments` objects. + * @param {number} [fromIndex=0] The index to start from. + * @returns {Array} Returns the new flattened array. */ - var forIn = createIterator(eachIteratorOptions, forOwnIteratorOptions, { - 'useHas': false - }); - - /** - * Iterates over an object's own enumerable properties, executing the `callback` - * for each property. The `callback` is bound to `thisArg` and invoked with three - * arguments; (value, key, object). Callbacks may exit iteration early by explicitly - * returning `false`. - * - * @static - * @memberOf _ - * @type Function - * @category Objects - * @param {Object} object The object to iterate over. - * @param {Function} [callback=identity] The function called per iteration. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Object} Returns `object`. - * @example - * - * _.forOwn({ '0': 'zero', '1': 'one', 'length': 2 }, function(num, key) { - * alert(key); - * }); - * // => alerts '0', '1', and 'length' (order is not guaranteed) - */ - var forOwn = createIterator(eachIteratorOptions, forOwnIteratorOptions); - - /** - * Creates a sorted array of all enumerable properties, own and inherited, - * of `object` that have function values. - * - * @static - * @memberOf _ - * @alias methods - * @category Objects - * @param {Object} object The object to inspect. - * @returns {Array} Returns a new array of property names that have function values. - * @example - * - * _.functions(_); - * // => ['all', 'any', 'bind', 'bindAll', 'clone', 'compact', 'compose', ...] - */ - function functions(object) { - var result = []; - forIn(object, function(value, key) { - if (isFunction(value)) { - result.push(key); - } - }); - return result.sort(); - } - - /** - * Checks if the specified object `property` exists and is a direct property, - * instead of an inherited property. - * - * @static - * @memberOf _ - * @category Objects - * @param {Object} object The object to check. - * @param {String} property The property to check for. - * @returns {Boolean} Returns `true` if key is a direct property, else `false`. - * @example - * - * _.has({ 'a': 1, 'b': 2, 'c': 3 }, 'b'); - * // => true - */ - function has(object, property) { - return object ? hasOwnProperty.call(object, property) : false; - } - - /** - * Creates an object composed of the inverted keys and values of the given `object`. - * - * @static - * @memberOf _ - * @category Objects - * @param {Object} object The object to invert. - * @returns {Object} Returns the created inverted object. - * @example - * - * _.invert({ 'first': 'moe', 'second': 'larry' }); - * // => { 'moe': 'first', 'larry': 'second' } - */ - function invert(object) { - var index = -1, - props = keys(object), - length = props.length, - result = {}; + function baseFlatten(array, isDeep, isStrict, fromIndex) { + var index = (fromIndex || 0) - 1, + length = array.length, + resIndex = -1, + result = []; while (++index < length) { - var key = props[index]; - result[object[key]] = key; + var value = array[index]; + + if (isObjectLike(value) && isLength(value.length) && (isArray(value) || isArguments(value))) { + if (isDeep) { + // Recursively flatten arrays (susceptible to call stack limits). + value = baseFlatten(value, isDeep, isStrict); + } + var valIndex = -1, + valLength = value.length; + + result.length += valLength; + while (++valIndex < valLength) { + result[++resIndex] = value[valIndex]; + } + } else if (!isStrict) { + result[++resIndex] = value; + } } return result; } /** - * Checks if `value` is a boolean value. + * The base implementation of `baseForIn` and `baseForOwn` which iterates + * over `object` properties returned by `keysFunc` invoking `iteratee` for + * each property. Iterator functions may exit iteration early by explicitly + * returning `false`. + * + * @private + * @param {Object} object The object to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @param {Function} keysFunc The function to get the keys of `object`. + * @returns {Object} Returns `object`. + */ + function baseFor(object, iteratee, keysFunc) { + var index = -1, + iterable = toObject(object), + props = keysFunc(object), + length = props.length; + + while (++index < length) { + var key = props[index]; + if (iteratee(iterable[key], key, iterable) === false) { + break; + } + } + return object; + } + + /** + * This function is like `baseFor` except that it iterates over properties + * in the opposite order. + * + * @private + * @param {Object} object The object to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @param {Function} keysFunc The function to get the keys of `object`. + * @returns {Object} Returns `object`. + */ + function baseForRight(object, iteratee, keysFunc) { + var iterable = toObject(object), + props = keysFunc(object), + length = props.length; + + while (length--) { + var key = props[length]; + if (iteratee(iterable[key], key, iterable) === false) { + break; + } + } + return object; + } + + /** + * The base implementation of `_.forIn` without support for callback + * shorthands and `this` binding. + * + * @private + * @param {Object} object The object to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @returns {Object} Returns `object`. + */ + function baseForIn(object, iteratee) { + return baseFor(object, iteratee, keysIn); + } + + /** + * The base implementation of `_.forOwn` without support for callback + * shorthands and `this` binding. + * + * @private + * @param {Object} object The object to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @returns {Object} Returns `object`. + */ + function baseForOwn(object, iteratee) { + return baseFor(object, iteratee, keys); + } + + /** + * The base implementation of `_.forOwnRight` without support for callback + * shorthands and `this` binding. + * + * @private + * @param {Object} object The object to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @returns {Object} Returns `object`. + */ + function baseForOwnRight(object, iteratee) { + return baseForRight(object, iteratee, keys); + } + + /** + * The base implementation of `_.functions` which creates an array of + * `object` function property names filtered from those provided. + * + * @private + * @param {Object} object The object to inspect. + * @param {Array} props The property names to filter. + * @returns {Array} Returns the new array of filtered property names. + */ + function baseFunctions(object, props) { + var index = -1, + length = props.length, + resIndex = -1, + result = []; + + while (++index < length) { + var key = props[index]; + if (isFunction(object[key])) { + result[++resIndex] = key; + } + } + return result; + } + + /** + * The base implementation of `_.invoke` which requires additional arguments + * to be provided as an array of arguments rather than individually. + * + * @private + * @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 {Array} [args] The arguments to invoke the method with. + * @returns {Array} Returns the array of results. + */ + function baseInvoke(collection, methodName, args) { + var index = -1, + isFunc = typeof methodName == 'function', + length = collection ? collection.length : 0, + result = isLength(length) ? Array(length) : []; + + baseEach(collection, function(value) { + var func = isFunc ? methodName : (value != null && value[methodName]); + result[++index] = func ? func.apply(value, args) : undefined; + }); + return result; + } + + /** + * The base implementation of `_.isEqual` without support for `this` binding + * `customizer` functions. + * + * @private + * @param {*} value The value to compare. + * @param {*} other The other value to compare. + * @param {Function} [customizer] The function to customize comparing values. + * @param {boolean} [isWhere] Specify performing partial comparisons. + * @param {Array} [stackA] Tracks traversed `value` objects. + * @param {Array} [stackB] Tracks traversed `other` objects. + * @returns {boolean} Returns `true` if the values are equivalent, else `false`. + */ + function baseIsEqual(value, other, customizer, isWhere, stackA, stackB) { + // Exit early for identical values. + if (value === other) { + // Treat `+0` vs. `-0` as not equal. + return value !== 0 || (1 / value == 1 / other); + } + var valType = typeof value, + othType = typeof other; + + // Exit early for unlike primitive values. + if ((valType != 'function' && valType != 'object' && othType != 'function' && othType != 'object') || + value == null || other == null) { + // Return `false` unless both values are `NaN`. + return value !== value && other !== other; + } + return baseIsEqualDeep(value, other, baseIsEqual, customizer, isWhere, stackA, stackB); + } + + /** + * A specialized version of `baseIsEqual` for arrays and objects which performs + * deep comparisons and tracks traversed objects enabling objects with circular + * references to be compared. + * + * @private + * @param {Object} object The object to compare. + * @param {Object} other The other object to compare. + * @param {Function} equalFunc The function to determine equivalents of values. + * @param {Function} [customizer] The function to customize comparing objects. + * @param {boolean} [isWhere] Specify performing partial comparisons. + * @param {Array} [stackA=[]] Tracks traversed `value` objects. + * @param {Array} [stackB=[]] Tracks traversed `other` objects. + * @returns {boolean} Returns `true` if the objects are equivalent, else `false`. + */ + function baseIsEqualDeep(object, other, equalFunc, customizer, isWhere, stackA, stackB) { + var objIsArr = isArray(object), + othIsArr = isArray(other), + objTag = arrayTag, + othTag = arrayTag; + + if (!objIsArr) { + objTag = objToString.call(object); + if (objTag == argsTag) { + objTag = objectTag; + } else if (objTag != objectTag) { + objIsArr = isTypedArray(object); + } + } + if (!othIsArr) { + othTag = objToString.call(other); + if (othTag == argsTag) { + othTag = objectTag; + } else if (othTag != objectTag) { + othIsArr = isTypedArray(other); + } + } + var objIsObj = objTag == objectTag, + othIsObj = othTag == objectTag, + isSameTag = objTag == othTag; + + if (isSameTag && !(objIsArr || objIsObj)) { + return equalByTag(object, other, objTag); + } + var valWrapped = objIsObj && hasOwnProperty.call(object, '__wrapped__'), + othWrapped = othIsObj && hasOwnProperty.call(other, '__wrapped__'); + + if (valWrapped || othWrapped) { + return equalFunc(valWrapped ? object.value() : object, othWrapped ? other.value() : other, customizer, isWhere, stackA, stackB); + } + if (!isSameTag) { + return false; + } + // Assume cyclic values are equal. + // For more information on detecting circular references see https://es5.github.io/#JO. + stackA || (stackA = []); + stackB || (stackB = []); + + var length = stackA.length; + while (length--) { + if (stackA[length] == object) { + return stackB[length] == other; + } + } + // Add `object` and `other` to the stack of traversed objects. + stackA.push(object); + stackB.push(other); + + var result = (objIsArr ? equalArrays : equalObjects)(object, other, equalFunc, customizer, isWhere, stackA, stackB); + + stackA.pop(); + stackB.pop(); + + return result; + } + + /** + * The base implementation of `_.isMatch` without support for callback + * shorthands or `this` binding. + * + * @private + * @param {Object} source The object to inspect. + * @param {Array} props The source property names to match. + * @param {Array} values The source values to match. + * @param {Array} strictCompareFlags Strict comparison flags for source values. + * @param {Function} [customizer] The function to customize comparing objects. + * @returns {boolean} Returns `true` if `object` is a match, else `false`. + */ + function baseIsMatch(object, props, values, strictCompareFlags, customizer) { + var length = props.length; + if (object == null) { + return !length; + } + var index = -1, + noCustomizer = !customizer; + + while (++index < length) { + if ((noCustomizer && strictCompareFlags[index]) + ? values[index] !== object[props[index]] + : !hasOwnProperty.call(object, props[index]) + ) { + return false; + } + } + index = -1; + while (++index < length) { + var key = props[index]; + if (noCustomizer && strictCompareFlags[index]) { + var result = hasOwnProperty.call(object, key); + } else { + var objValue = object[key], + srcValue = values[index]; + + result = customizer ? customizer(objValue, srcValue, key) : undefined; + if (typeof result == 'undefined') { + result = baseIsEqual(srcValue, objValue, customizer, true); + } + } + if (!result) { + return false; + } + } + return true; + } + + /** + * The base implementation of `_.map` without support for callback shorthands + * or `this` binding. + * + * @private + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @returns {Array} Returns the new mapped array. + */ + function baseMap(collection, iteratee) { + var result = []; + baseEach(collection, function(value, key, collection) { + result.push(iteratee(value, key, collection)); + }); + return result; + } + + /** + * The base implementation of `_.matches` which supports specifying whether + * `source` should be cloned. + * + * @private + * @param {Object} source The object of property values to match. + * @param {boolean} [isCloned] Specify cloning the source object. + * @returns {Function} Returns the new function. + */ + function baseMatches(source, isCloned) { + var props = keys(source), + length = props.length; + + if (length == 1) { + var key = props[0], + value = source[key]; + + if (isStrictComparable(value)) { + return function(object) { + return object != null && value === object[key] && hasOwnProperty.call(object, key); + }; + } + } + if (isCloned) { + source = baseClone(source, true); + } + var values = Array(length), + strictCompareFlags = Array(length); + + while (length--) { + value = source[props[length]]; + values[length] = value; + strictCompareFlags[length] = isStrictComparable(value); + } + return function(object) { + return baseIsMatch(object, props, values, strictCompareFlags); + }; + } + + /** + * The base implementation of `_.merge` without support for argument juggling, + * multiple sources, and `this` binding `customizer` functions. + * + * @private + * @param {Object} object The destination object. + * @param {Object} source The source object. + * @param {Function} [customizer] The function to customize merging properties. + * @param {Array} [stackA=[]] Tracks traversed source objects. + * @param {Array} [stackB=[]] Associates values with source counterparts. + * @returns {Object} Returns the destination object. + */ + function baseMerge(object, source, customizer, stackA, stackB) { + var isSrcArr = isLength(source.length) && (isArray(source) || isTypedArray(source)); + + (isSrcArr ? arrayEach : baseForOwn)(source, function(srcValue, key, source) { + if (isObjectLike(srcValue)) { + stackA || (stackA = []); + stackB || (stackB = []); + return baseMergeDeep(object, source, key, baseMerge, customizer, stackA, stackB); + } + var value = object[key], + result = customizer ? customizer(value, srcValue, key, object, source) : undefined, + isCommon = typeof result == 'undefined'; + + if (isCommon) { + result = srcValue; + } + if ((isSrcArr || typeof result != 'undefined') && + (isCommon || (result === result ? result !== value : value === value))) { + object[key] = result; + } + }); + return object; + } + + /** + * A specialized version of `baseMerge` for arrays and objects which performs + * deep merges and tracks traversed objects enabling objects with circular + * references to be merged. + * + * @private + * @param {Object} object The destination object. + * @param {Object} source The source object. + * @param {string} key The key of the value to merge. + * @param {Function} mergeFunc The function to merge values. + * @param {Function} [customizer] The function to customize merging properties. + * @param {Array} [stackA=[]] Tracks traversed source objects. + * @param {Array} [stackB=[]] Associates values with source counterparts. + * @returns {boolean} Returns `true` if the objects are equivalent, else `false`. + */ + function baseMergeDeep(object, source, key, mergeFunc, customizer, stackA, stackB) { + var length = stackA.length, + srcValue = source[key]; + + while (length--) { + if (stackA[length] == srcValue) { + object[key] = stackB[length]; + return; + } + } + var value = object[key], + result = customizer ? customizer(value, srcValue, key, object, source) : undefined, + isCommon = typeof result == 'undefined'; + + if (isCommon) { + result = srcValue; + if (isLength(srcValue.length) && (isArray(srcValue) || isTypedArray(srcValue))) { + result = isArray(value) + ? value + : (value ? arrayCopy(value) : []); + } + else if (isPlainObject(srcValue) || isArguments(srcValue)) { + result = isArguments(value) + ? toPlainObject(value) + : (isPlainObject(value) ? value : {}); + } + else { + isCommon = false; + } + } + // Add the source value to the stack of traversed objects and associate + // it with its merged value. + stackA.push(srcValue); + stackB.push(result); + + if (isCommon) { + // Recursively merge objects and arrays (susceptible to call stack limits). + object[key] = mergeFunc(result, srcValue, customizer, stackA, stackB); + } else if (result === result ? result !== value : value === value) { + object[key] = result; + } + } + + /** + * The base implementation of `_.property` which does not coerce `key` to a string. + * + * @private + * @param {string} key The key of the property to get. + * @returns {Function} Returns the new function. + */ + function baseProperty(key) { + return function(object) { + return object == null ? undefined : object[key]; + }; + } + + /** + * The base implementation of `_.pullAt` without support for individual + * index arguments. + * + * @private + * @param {Array} array The array to modify. + * @param {number[]} indexes The indexes of elements to remove. + * @returns {Array} Returns the new array of removed elements. + */ + function basePullAt(array, indexes) { + var length = indexes.length, + result = baseAt(array, indexes); + + indexes.sort(baseCompareAscending); + while (length--) { + var index = parseFloat(indexes[length]); + if (index != previous && isIndex(index)) { + var previous = index; + splice.call(array, index, 1); + } + } + return result; + } + + /** + * The base implementation of `_.random` without support for argument juggling + * and returning floating-point numbers. + * + * @private + * @param {number} min The minimum possible value. + * @param {number} max The maximum possible value. + * @returns {number} Returns the random number. + */ + function baseRandom(min, max) { + return min + floor(nativeRandom() * (max - min + 1)); + } + + /** + * The base implementation of `_.reduce` and `_.reduceRight` without support + * for callback shorthands or `this` binding, which iterates over `collection` + * using the provided `eachFunc`. + * + * @private + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @param {*} accumulator The initial value. + * @param {boolean} initFromCollection Specify using the first or last element + * of `collection` as the initial value. + * @param {Function} eachFunc The function to iterate over `collection`. + * @returns {*} Returns the accumulated value. + */ + function baseReduce(collection, iteratee, accumulator, initFromCollection, eachFunc) { + eachFunc(collection, function(value, index, collection) { + accumulator = initFromCollection + ? (initFromCollection = false, value) + : iteratee(accumulator, value, index, collection) + }); + return accumulator; + } + + /** + * The base implementation of `setData` without support for hot loop detection. + * + * @private + * @param {Function} func The function to associate metadata with. + * @param {*} data The metadata. + * @returns {Function} Returns `func`. + */ + var baseSetData = !metaMap ? identity : function(func, data) { + metaMap.set(func, data); + return func; + }; + + /** + * The base implementation of `_.slice` without an iteratee call guard. + * + * @private + * @param {Array} array The array to slice. + * @param {number} [start=0] The start position. + * @param {number} [end=array.length] The end position. + * @returns {Array} Returns the slice of `array`. + */ + function baseSlice(array, start, end) { + var index = -1, + length = array.length; + + start = start == null ? 0 : (+start || 0); + if (start < 0) { + start = -start > length ? 0 : (length + start); + } + end = (typeof end == 'undefined' || end > length) ? length : (+end || 0); + if (end < 0) { + end += length; + } + length = start > end ? 0 : (end - start) >>> 0; + start >>>= 0; + + var result = Array(length); + while (++index < length) { + result[index] = array[index + start]; + } + return result; + } + + /** + * The base implementation of `_.some` without support for callback shorthands + * or `this` binding. + * + * @private + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} predicate The function invoked per iteration. + * @returns {boolean} Returns `true` if any element passes the predicate check, + * else `false`. + */ + function baseSome(collection, predicate) { + var result; + + baseEach(collection, function(value, index, collection) { + result = predicate(value, index, collection); + return !result; + }); + return !!result; + } + + /** + * The base implementation of `_.uniq` without support for callback shorthands + * and `this` binding. + * + * @private + * @param {Array} array The array to inspect. + * @param {Function} [iteratee] The function invoked per iteration. + * @returns {Array} Returns the new duplicate-value-free array. + */ + function baseUniq(array, iteratee) { + var index = -1, + indexOf = getIndexOf(), + length = array.length, + isCommon = indexOf == baseIndexOf, + isLarge = isCommon && length >= 200, + seen = isLarge && createCache(), + result = []; + + if (seen) { + indexOf = cacheIndexOf; + isCommon = false; + } else { + isLarge = false; + seen = iteratee ? [] : result; + } + outer: + while (++index < length) { + var value = array[index], + computed = iteratee ? iteratee(value, index, array) : value; + + if (isCommon && value === value) { + var seenIndex = seen.length; + while (seenIndex--) { + if (seen[seenIndex] === computed) { + continue outer; + } + } + if (iteratee) { + seen.push(computed); + } + result.push(value); + } + else if (indexOf(seen, computed) < 0) { + if (iteratee || isLarge) { + seen.push(computed); + } + result.push(value); + } + } + return result; + } + + /** + * The base implementation of `_.values` and `_.valuesIn` which creates an + * array of `object` property values corresponding to the property names + * returned by `keysFunc`. + * + * @private + * @param {Object} object The object to query. + * @param {Array} props The property names to get values for. + * @returns {Object} Returns the array of property values. + */ + function baseValues(object, props) { + var index = -1, + length = props.length, + result = Array(length); + + while (++index < length) { + result[index] = object[props[index]]; + } + return result; + } + + /** + * The base implementation of `wrapperValue` which returns the result of + * performing a sequence of actions on the unwrapped `value`, where each + * successive action is supplied the return value of the previous. + * + * @private + * @param {*} value The unwrapped value. + * @param {Array} actions Actions to peform to resolve the unwrapped value. + * @returns {*} Returns the resolved unwrapped value. + */ + function baseWrapperValue(value, actions) { + var result = value; + if (result instanceof LazyWrapper) { + result = result.value(); + } + var index = -1, + length = actions.length; + + while (++index < length) { + var args = [result], + action = actions[index]; + + push.apply(args, action.args); + result = action.func.apply(action.thisArg, args); + } + return result; + } + + /** + * Performs a binary search of `array` to determine the index at which `value` + * should be inserted into `array` in order to maintain its sort order. + * + * @private + * @param {Array} array The sorted array to inspect. + * @param {*} value The value to evaluate. + * @param {boolean} [retHighest] Specify returning the highest, instead + * of the lowest, index at which a value should be inserted into `array`. + * @returns {number} Returns the index at which `value` should be inserted + * into `array`. + */ + function binaryIndex(array, value, retHighest) { + var low = 0, + high = array ? array.length : low; + + if (typeof value == 'number' && value === value && high <= HALF_MAX_ARRAY_LENGTH) { + while (low < high) { + var mid = (low + high) >>> 1, + computed = array[mid]; + + if (retHighest ? (computed <= value) : (computed < value)) { + low = mid + 1; + } else { + high = mid; + } + } + return high; + } + return binaryIndexBy(array, value, identity, retHighest); + } + + /** + * This function is like `binaryIndex` except that it invokes `iteratee` for + * `value` and each element of `array` to compute their sort ranking. The + * iteratee is invoked with one argument; (value). + * + * @private + * @param {Array} array The sorted array to inspect. + * @param {*} value The value to evaluate. + * @param {Function} iteratee The function invoked per iteration. + * @param {boolean} [retHighest] Specify returning the highest, instead + * of the lowest, index at which a value should be inserted into `array`. + * @returns {number} Returns the index at which `value` should be inserted + * into `array`. + */ + function binaryIndexBy(array, value, iteratee, retHighest) { + value = iteratee(value); + + var low = 0, + high = array ? array.length : 0, + valIsNaN = value !== value, + valIsUndef = typeof value == 'undefined'; + + while (low < high) { + var mid = floor((low + high) / 2), + computed = iteratee(array[mid]), + isReflexive = computed === computed; + + if (valIsNaN) { + var setLow = isReflexive || retHighest; + } else if (valIsUndef) { + setLow = isReflexive && (retHighest || typeof computed != 'undefined'); + } else { + setLow = retHighest ? (computed <= value) : (computed < value); + } + if (setLow) { + low = mid + 1; + } else { + high = mid; + } + } + return nativeMin(high, MAX_ARRAY_INDEX); + } + + /** + * A specialized version of `baseCallback` which only supports `this` binding + * and specifying the number of arguments to provide to `func`. + * + * @private + * @param {Function} func The function to bind. + * @param {*} thisArg The `this` binding of `func`. + * @param {number} [argCount] The number of arguments to provide to `func`. + * @returns {Function} Returns the callback. + */ + function bindCallback(func, thisArg, argCount) { + if (typeof func != 'function') { + return identity; + } + if (typeof thisArg == 'undefined') { + return func; + } + switch (argCount) { + case 1: return function(value) { + return func.call(thisArg, value); + }; + 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); + }; + case 5: return function(value, other, key, object, source) { + return func.call(thisArg, value, other, key, object, source); + }; + } + return function() { + return func.apply(thisArg, arguments); + }; + } + + /** + * Creates a clone of the given array buffer. + * + * @private + * @param {ArrayBuffer} buffer The array buffer to clone. + * @returns {ArrayBuffer} Returns the cloned array buffer. + */ + function bufferClone(buffer) { + return bufferSlice.call(buffer, 0); + } + if (!bufferSlice) { + // PhantomJS has `ArrayBuffer` and `Uint8Array` but not `Float64Array`. + bufferClone = !(ArrayBuffer && Uint8Array) ? constant(null) : function(buffer) { + var byteLength = buffer.byteLength, + floatLength = Float64Array ? floor(byteLength / FLOAT64_BYTES_PER_ELEMENT) : 0, + offset = floatLength * FLOAT64_BYTES_PER_ELEMENT, + result = new ArrayBuffer(byteLength); + + if (floatLength) { + var view = new Float64Array(result, 0, floatLength); + view.set(new Float64Array(buffer, 0, floatLength)); + } + if (byteLength != offset) { + view = new Uint8Array(result, offset); + view.set(new Uint8Array(buffer, offset)); + } + return result; + }; + } + + /** + * Creates an array that is the composition of partially applied arguments, + * placeholders, and provided arguments into a single array of arguments. + * + * @private + * @param {Array|Object} args The provided arguments. + * @param {Array} partials The arguments to prepend to those provided. + * @param {Array} holders The `partials` placeholder indexes. + * @returns {Array} Returns the new array of composed arguments. + */ + function composeArgs(args, partials, holders) { + var holdersLength = holders.length, + argsIndex = -1, + argsLength = nativeMax(args.length - holdersLength, 0), + leftIndex = -1, + leftLength = partials.length, + result = Array(argsLength + leftLength); + + while (++leftIndex < leftLength) { + result[leftIndex] = partials[leftIndex]; + } + while (++argsIndex < holdersLength) { + result[holders[argsIndex]] = args[argsIndex]; + } + while (argsLength--) { + result[leftIndex++] = args[argsIndex++]; + } + return result; + } + + /** + * This function is like `composeArgs` except that the arguments composition + * is tailored for `_.partialRight`. + * + * @private + * @param {Array|Object} args The provided arguments. + * @param {Array} partials The arguments to append to those provided. + * @param {Array} holders The `partials` placeholder indexes. + * @returns {Array} Returns the new array of composed arguments. + */ + function composeArgsRight(args, partials, holders) { + var holdersIndex = -1, + holdersLength = holders.length, + argsIndex = -1, + argsLength = nativeMax(args.length - holdersLength, 0), + rightIndex = -1, + rightLength = partials.length, + result = Array(argsLength + rightLength); + + while (++argsIndex < argsLength) { + result[argsIndex] = args[argsIndex]; + } + var pad = argsIndex; + while (++rightIndex < rightLength) { + result[pad + rightIndex] = partials[rightIndex]; + } + while (++holdersIndex < holdersLength) { + result[pad + holders[holdersIndex]] = args[argsIndex++]; + } + return result; + } + + /** + * Creates a function that aggregates a collection, creating an accumulator + * object composed from the results of running each element in the collection + * through an iteratee. The `setter` sets the keys and values of the accumulator + * object. If `initializer` is provided initializes the accumulator object. + * + * @private + * @param {Function} setter The function to set keys and values of the accumulator object. + * @param {Function} [initializer] The function to initialize the accumulator object. + * @returns {Function} Returns the new aggregator function. + */ + function createAggregator(setter, initializer) { + return function(collection, iteratee, thisArg) { + var result = initializer ? initializer() : {}; + iteratee = getCallback(iteratee, thisArg, 3); + + if (isArray(collection)) { + var index = -1, + length = collection.length; + + while (++index < length) { + var value = collection[index]; + setter(result, value, iteratee(value, index, collection), collection); + } + } else { + baseEach(collection, function(value, key, collection) { + setter(result, value, iteratee(value, key, collection), collection); + }); + } + return result; + }; + } + + /** + * Creates a function that assigns properties of source object(s) to a given + * destination object. + * + * @private + * @param {Function} assigner The function to assign values. + * @returns {Function} Returns the new assigner function. + */ + function createAssigner(assigner) { + return function() { + var length = arguments.length, + object = arguments[0]; + + if (length < 2 || object == null) { + return object; + } + if (length > 3 && isIterateeCall(arguments[1], arguments[2], arguments[3])) { + length = 2; + } + // Juggle arguments. + if (length > 3 && typeof arguments[length - 2] == 'function') { + var customizer = bindCallback(arguments[--length - 1], arguments[length--], 5); + } else if (length > 2 && typeof arguments[length - 1] == 'function') { + customizer = arguments[--length]; + } + var index = 0; + while (++index < length) { + var source = arguments[index]; + if (source) { + assigner(object, source, customizer); + } + } + return object; + }; + } + + /** + * Creates a function that wraps `func` and invokes it with the `this` + * binding of `thisArg`. + * + * @private + * @param {Function} func The function to bind. + * @param {*} [thisArg] The `this` binding of `func`. + * @returns {Function} Returns the new bound function. + */ + function createBindWrapper(func, thisArg) { + var Ctor = createCtorWrapper(func); + + function wrapper() { + return (this instanceof wrapper ? Ctor : func).apply(thisArg, arguments); + } + return wrapper; + } + + /** + * Creates a `Set` cache object to optimize linear searches of large arrays. + * + * @private + * @param {Array} [values] The values to cache. + * @returns {null|Object} Returns the new cache object if `Set` is supported, else `null`. + */ + var createCache = !(nativeCreate && Set) ? constant(null) : function(values) { + return new SetCache(values); + }; + + /** + * Creates a function that produces compound words out of the words in a + * given string. + * + * @private + * @param {Function} callback The function to combine each word. + * @returns {Function} Returns the new compounder function. + */ + function createCompounder(callback) { + return function(string) { + var index = -1, + array = words(deburr(string)), + length = array.length, + result = ''; + + while (++index < length) { + result = callback(result, array[index], index); + } + return result; + }; + } + + /** + * Creates a function that produces an instance of `Ctor` regardless of + * whether it was invoked as part of a `new` expression or by `call` or `apply`. + * + * @private + * @param {Function} Ctor The constructor to wrap. + * @returns {Function} Returns the new wrapped function. + */ + function createCtorWrapper(Ctor) { + return function() { + var thisBinding = baseCreate(Ctor.prototype), + result = Ctor.apply(thisBinding, arguments); + + // Mimic the constructor's `return` behavior. + // See https://es5.github.io/#x13.2.2 for more details. + return isObject(result) ? result : thisBinding; + }; + } + + /** + * Creates a function that gets the extremum value of a collection. + * + * @private + * @param {Function} arrayFunc The function to get the extremum value from an array. + * @param {boolean} [isMin] Specify returning the minimum, instead of the maximum, + * extremum value. + * @returns {Function} Returns the new extremum function. + */ + function createExtremum(arrayFunc, isMin) { + return function(collection, iteratee, thisArg) { + if (thisArg && isIterateeCall(collection, iteratee, thisArg)) { + iteratee = null; + } + var func = getCallback(), + noIteratee = iteratee == null; + + if (!(func === baseCallback && noIteratee)) { + noIteratee = false; + iteratee = func(iteratee, thisArg, 3); + } + if (noIteratee) { + var isArr = isArray(collection); + if (!isArr && isString(collection)) { + iteratee = charAtCallback; + } else { + return arrayFunc(isArr ? collection : toIterable(collection)); + } + } + return extremumBy(collection, iteratee, isMin); + }; + } + + /** + * Creates a function that wraps `func` and invokes it with optional `this` + * binding of, partial application, and currying. + * + * @private + * @param {Function|string} func The function or method name to reference. + * @param {number} bitmask The bitmask of flags. See `createWrapper` for more details. + * @param {*} [thisArg] The `this` binding of `func`. + * @param {Array} [partials] The arguments to prepend to those provided to the new function. + * @param {Array} [holders] The `partials` placeholder indexes. + * @param {Array} [partialsRight] The arguments to append to those provided to the new function. + * @param {Array} [holdersRight] The `partialsRight` placeholder indexes. + * @param {Array} [argPos] The argument positions of the new function. + * @param {number} [ary] The arity cap of `func`. + * @param {number} [arity] The arity of `func`. + * @returns {Function} Returns the new wrapped function. + */ + function createHybridWrapper(func, bitmask, thisArg, partials, holders, partialsRight, holdersRight, argPos, ary, arity) { + var isAry = bitmask & ARY_FLAG, + isBind = bitmask & BIND_FLAG, + isBindKey = bitmask & BIND_KEY_FLAG, + isCurry = bitmask & CURRY_FLAG, + isCurryBound = bitmask & CURRY_BOUND_FLAG, + isCurryRight = bitmask & CURRY_RIGHT_FLAG; + + var Ctor = !isBindKey && createCtorWrapper(func), + key = func; + + function wrapper() { + // Avoid `arguments` object use disqualifying optimizations by + // converting it to an array before providing it to other functions. + var length = arguments.length, + index = length, + args = Array(length); + + while (index--) { + args[index] = arguments[index]; + } + if (partials) { + args = composeArgs(args, partials, holders); + } + if (partialsRight) { + args = composeArgsRight(args, partialsRight, holdersRight); + } + if (isCurry || isCurryRight) { + var placeholder = wrapper.placeholder, + argsHolders = replaceHolders(args, placeholder); + + length -= argsHolders.length; + if (length < arity) { + var newArgPos = argPos ? arrayCopy(argPos) : null, + newArity = nativeMax(arity - length, 0), + newsHolders = isCurry ? argsHolders : null, + newHoldersRight = isCurry ? null : argsHolders, + newPartials = isCurry ? args : null, + newPartialsRight = isCurry ? null : args; + + bitmask |= (isCurry ? PARTIAL_FLAG : PARTIAL_RIGHT_FLAG); + bitmask &= ~(isCurry ? PARTIAL_RIGHT_FLAG : PARTIAL_FLAG); + + if (!isCurryBound) { + bitmask &= ~(BIND_FLAG | BIND_KEY_FLAG); + } + var result = createHybridWrapper(func, bitmask, thisArg, newPartials, newsHolders, newPartialsRight, newHoldersRight, newArgPos, ary, newArity); + result.placeholder = placeholder; + return result; + } + } + var thisBinding = isBind ? thisArg : this; + if (isBindKey) { + func = thisBinding[key]; + } + if (argPos) { + args = reorder(args, argPos); + } + if (isAry && ary < args.length) { + args.length = ary; + } + return (this instanceof wrapper ? (Ctor || createCtorWrapper(func)) : func).apply(thisBinding, args); + } + return wrapper; + } + + /** + * Creates the pad required for `string` based on the given padding length. + * The `chars` string may be truncated if the number of padding characters + * exceeds the padding length. + * + * @private + * @param {string} string The string to create padding for. + * @param {number} [length=0] The padding length. + * @param {string} [chars=' '] The string used as padding. + * @returns {string} Returns the pad for `string`. + */ + function createPad(string, length, chars) { + var strLength = string.length; + length = +length; + + if (strLength >= length || !nativeIsFinite(length)) { + return ''; + } + var padLength = length - strLength; + chars = chars == null ? ' ' : (chars + ''); + return repeat(chars, ceil(padLength / chars.length)).slice(0, padLength); + } + + /** + * Creates a function that wraps `func` and invokes it with the optional `this` + * binding of `thisArg` and the `partials` prepended to those provided to + * the wrapper. + * + * @private + * @param {Function} func The function to partially apply arguments to. + * @param {number} bitmask The bitmask of flags. See `createWrapper` for more details. + * @param {*} thisArg The `this` binding of `func`. + * @param {Array} partials The arguments to prepend to those provided to the new function. + * @returns {Function} Returns the new bound function. + */ + function createPartialWrapper(func, bitmask, thisArg, partials) { + var isBind = bitmask & BIND_FLAG, + Ctor = createCtorWrapper(func); + + function wrapper() { + // Avoid `arguments` object use disqualifying optimizations by + // converting it to an array before providing it `func`. + var argsIndex = -1, + argsLength = arguments.length, + leftIndex = -1, + leftLength = partials.length, + args = Array(argsLength + leftLength); + + while (++leftIndex < leftLength) { + args[leftIndex] = partials[leftIndex]; + } + while (argsLength--) { + args[leftIndex++] = arguments[++argsIndex]; + } + return (this instanceof wrapper ? Ctor : func).apply(isBind ? thisArg : this, args); + } + return wrapper; + } + + /** + * Creates a function that either curries or invokes `func` with optional + * `this` binding and partially applied arguments. + * + * @private + * @param {Function|string} func The function or method name to reference. + * @param {number} bitmask The bitmask of flags. + * The bitmask may be composed of the following flags: + * 1 - `_.bind` + * 2 - `_.bindKey` + * 4 - `_.curry` or `_.curryRight` of a bound function + * 8 - `_.curry` + * 16 - `_.curryRight` + * 32 - `_.partial` + * 64 - `_.partialRight` + * 128 - `_.rearg` + * 256 - `_.ary` + * @param {*} [thisArg] The `this` binding of `func`. + * @param {Array} [partials] The arguments to be partially applied. + * @param {Array} [holders] The `partials` placeholder indexes. + * @param {Array} [argPos] The argument positions of the new function. + * @param {number} [ary] The arity cap of `func`. + * @param {number} [arity] The arity of `func`. + * @returns {Function} Returns the new wrapped function. + */ + function createWrapper(func, bitmask, thisArg, partials, holders, argPos, ary, arity) { + var isBindKey = bitmask & BIND_KEY_FLAG; + if (!isBindKey && !isFunction(func)) { + throw new TypeError(FUNC_ERROR_TEXT); + } + var length = partials ? partials.length : 0; + if (!length) { + bitmask &= ~(PARTIAL_FLAG | PARTIAL_RIGHT_FLAG); + partials = holders = null; + } + length -= (holders ? holders.length : 0); + if (bitmask & PARTIAL_RIGHT_FLAG) { + var partialsRight = partials, + holdersRight = holders; + + partials = holders = null; + } + var data = !isBindKey && getData(func), + newData = [func, bitmask, thisArg, partials, holders, partialsRight, holdersRight, argPos, ary, arity]; + + if (data && data !== true) { + mergeData(newData, data); + bitmask = newData[1]; + arity = newData[9]; + } + newData[9] = arity == null + ? (isBindKey ? 0 : func.length) + : (nativeMax(arity - length, 0) || 0); + + if (bitmask == BIND_FLAG) { + var result = createBindWrapper(newData[0], newData[2]); + } else if ((bitmask == PARTIAL_FLAG || bitmask == (BIND_FLAG | PARTIAL_FLAG)) && !newData[4].length) { + result = createPartialWrapper.apply(null, newData); + } else { + result = createHybridWrapper.apply(null, newData); + } + var setter = data ? baseSetData : setData; + return setter(result, newData); + } + + /** + * A specialized version of `baseIsEqualDeep` for arrays with support for + * partial deep comparisons. + * + * @private + * @param {Array} array The array to compare. + * @param {Array} other The other array to compare. + * @param {Function} equalFunc The function to determine equivalents of values. + * @param {Function} [customizer] The function to customize comparing arrays. + * @param {boolean} [isWhere] Specify performing partial comparisons. + * @param {Array} [stackA] Tracks traversed `value` objects. + * @param {Array} [stackB] Tracks traversed `other` objects. + * @returns {boolean} Returns `true` if the arrays are equivalent, else `false`. + */ + function equalArrays(array, other, equalFunc, customizer, isWhere, stackA, stackB) { + var index = -1, + arrLength = array.length, + othLength = other.length, + result = true; + + if (arrLength != othLength && !(isWhere && othLength > arrLength)) { + return false; + } + // Deep compare the contents, ignoring non-numeric properties. + while (result && ++index < arrLength) { + var arrValue = array[index], + othValue = other[index]; + + result = undefined; + if (customizer) { + result = isWhere + ? customizer(othValue, arrValue, index) + : customizer(arrValue, othValue, index); + } + if (typeof result == 'undefined') { + // Recursively compare arrays (susceptible to call stack limits). + if (isWhere) { + var othIndex = othLength; + while (othIndex--) { + othValue = other[othIndex]; + result = (arrValue && arrValue === othValue) || equalFunc(arrValue, othValue, customizer, isWhere, stackA, stackB); + if (result) { + break; + } + } + } else { + result = (arrValue && arrValue === othValue) || equalFunc(arrValue, othValue, customizer, isWhere, stackA, stackB); + } + } + } + return !!result; + } + + /** + * A specialized version of `baseIsEqualDeep` for comparing objects of + * the same `toStringTag`. + * + * **Note:** This function only supports comparing values with tags of + * `Boolean`, `Date`, `Error`, `Number`, `RegExp`, or `String`. + * + * @private + * @param {Object} value The object to compare. + * @param {Object} other The other object to compare. + * @param {string} tag The `toStringTag` of the objects to compare. + * @returns {boolean} Returns `true` if the objects are equivalent, else `false`. + */ + function equalByTag(object, other, tag) { + switch (tag) { + case boolTag: + case dateTag: + // 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 +object == +other; + + case errorTag: + return object.name == other.name && object.message == other.message; + + case numberTag: + // Treat `NaN` vs. `NaN` as equal. + return (object != +object) + ? other != +other + // But, treat `-0` vs. `+0` as not equal. + : (object == 0 ? ((1 / object) == (1 / other)) : object == +other); + + case regexpTag: + case stringTag: + // Coerce regexes to strings and treat strings primitives and string + // objects as equal. See https://es5.github.io/#x15.10.6.4 for more details. + return object == (other + ''); + } + return false; + } + + /** + * A specialized version of `baseIsEqualDeep` for objects with support for + * partial deep comparisons. + * + * @private + * @param {Object} object The object to compare. + * @param {Object} other The other object to compare. + * @param {Function} equalFunc The function to determine equivalents of values. + * @param {Function} [customizer] The function to customize comparing values. + * @param {boolean} [isWhere] Specify performing partial comparisons. + * @param {Array} [stackA] Tracks traversed `value` objects. + * @param {Array} [stackB] Tracks traversed `other` objects. + * @returns {boolean} Returns `true` if the objects are equivalent, else `false`. + */ + function equalObjects(object, other, equalFunc, customizer, isWhere, stackA, stackB) { + var objProps = keys(object), + objLength = objProps.length, + othProps = keys(other), + othLength = othProps.length; + + if (objLength != othLength && !isWhere) { + return false; + } + var hasCtor, + index = -1; + + while (++index < objLength) { + var key = objProps[index], + result = hasOwnProperty.call(other, key); + + if (result) { + var objValue = object[key], + othValue = other[key]; + + result = undefined; + if (customizer) { + result = isWhere + ? customizer(othValue, objValue, key) + : customizer(objValue, othValue, key); + } + if (typeof result == 'undefined') { + // Recursively compare objects (susceptible to call stack limits). + result = (objValue && objValue === othValue) || equalFunc(objValue, othValue, customizer, isWhere, stackA, stackB); + } + } + if (!result) { + return false; + } + hasCtor || (hasCtor = key == 'constructor'); + } + if (!hasCtor) { + var objCtor = object.constructor, + othCtor = other.constructor; + + // Non `Object` object instances with different constructors are not equal. + if (objCtor != othCtor && ('constructor' in object && 'constructor' in other) && + !(typeof objCtor == 'function' && objCtor instanceof objCtor && typeof othCtor == 'function' && othCtor instanceof othCtor)) { + return false; + } + } + return true; + } + + /** + * Gets the extremum value of `collection` invoking `iteratee` for each value + * in `collection` to generate the criterion by which the value is ranked. + * The `iteratee` is invoked with three arguments; (value, index, collection). + * + * @private + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @param {boolean} [isMin] Specify returning the minimum, instead of the + * maximum, extremum value. + * @returns {*} Returns the extremum value. + */ + function extremumBy(collection, iteratee, isMin) { + var exValue = isMin ? POSITIVE_INFINITY : NEGATIVE_INFINITY, + computed = exValue, + result = computed; + + baseEach(collection, function(value, index, collection) { + var current = iteratee(value, index, collection); + if ((isMin ? current < computed : current > computed) || (current === exValue && current === result)) { + computed = current; + result = value; + } + }); + return result; + } + + /** + * Gets the appropriate "callback" function. If the `_.callback` method is + * customized this function returns the custom method, otherwise it returns + * the `baseCallback` function. If arguments are provided the chosen function + * is invoked with them and its result is returned. + * + * @private + * @returns {Function} Returns the chosen function or its result. + */ + function getCallback(func, thisArg, argCount) { + var result = lodash.callback || callback; + result = result === callback ? baseCallback : result; + return argCount ? result(func, thisArg, argCount) : result; + } + + /** + * Gets metadata for `func`. + * + * @private + * @param {Function} func The function to query. + * @returns {*} Returns the metadata for `func`. + */ + var getData = !metaMap ? noop : function(func) { + return metaMap.get(func); + }; + + /** + * Gets the appropriate "indexOf" function. If the `_.indexOf` method is + * customized this function returns the custom method, otherwise it returns + * the `baseIndexOf` function. If arguments are provided the chosen function + * is invoked with them and its result is returned. + * + * @private + * @returns {Function|number} Returns the chosen function or its result. + */ + function getIndexOf(collection, target, fromIndex) { + var result = lodash.indexOf || indexOf; + result = result === indexOf ? baseIndexOf : result; + return collection ? result(collection, target, fromIndex) : result; + } + + /** + * Gets the view, applying any `transforms` to the `start` and `end` positions. + * + * @private + * @param {number} start The start of the view. + * @param {number} end The end of the view. + * @param {Array} [transforms] The transformations to apply to the view. + * @returns {Object} Returns an object containing the `start` and `end` + * positions of the view. + */ + function getView(start, end, transforms) { + var index = -1, + length = transforms ? transforms.length : 0; + + while (++index < length) { + var data = transforms[index], + size = data.size; + + switch (data.type) { + case 'drop': start += size; break; + case 'dropRight': end -= size; break; + case 'take': end = nativeMin(end, start + size); break; + case 'takeRight': start = nativeMax(start, end - size); break; + } + } + return { 'start': start, 'end': end }; + } + + /** + * Initializes an array clone. + * + * @private + * @param {Array} array The array to clone. + * @returns {Array} Returns the initialized clone. + */ + function initCloneArray(array) { + var length = array.length, + result = new array.constructor(length); + + // Add array properties assigned by `RegExp#exec`. + if (length && typeof array[0] == 'string' && hasOwnProperty.call(array, 'index')) { + result.index = array.index; + result.input = array.input; + } + return result; + } + + /** + * Initializes an object clone. + * + * @private + * @param {Object} object The object to clone. + * @returns {Object} Returns the initialized clone. + */ + function initCloneObject(object) { + var Ctor = object.constructor; + if (!(typeof Ctor == 'function' && Ctor instanceof Ctor)) { + Ctor = Object; + } + return new Ctor; + } + + /** + * Initializes an object clone based on its `toStringTag`. + * + * **Note:** This function only supports cloning values with tags of + * `Boolean`, `Date`, `Error`, `Number`, `RegExp`, or `String`. + * + * + * @private + * @param {Object} object The object to clone. + * @param {string} tag The `toStringTag` of the object to clone. + * @param {boolean} [isDeep] Specify a deep clone. + * @returns {Object} Returns the initialized clone. + */ + function initCloneByTag(object, tag, isDeep) { + var Ctor = object.constructor; + switch (tag) { + case arrayBufferTag: + return bufferClone(object); + + case boolTag: + case dateTag: + return new Ctor(+object); + + case float32Tag: case float64Tag: + case int8Tag: case int16Tag: case int32Tag: + case uint8Tag: case uint8ClampedTag: case uint16Tag: case uint32Tag: + var buffer = object.buffer; + return new Ctor(isDeep ? bufferClone(buffer) : buffer, object.byteOffset, object.length); + + case numberTag: + case stringTag: + return new Ctor(object); + + case regexpTag: + var result = new Ctor(object.source, reFlags.exec(object)); + result.lastIndex = object.lastIndex; + } + return result; + } + + /** + * Checks if `func` is eligible for `this` binding. + * + * @private + * @param {Function} func The function to check. + * @returns {boolean} Returns `true` if `func` is eligible, else `false`. + */ + function isBindable(func) { + var support = lodash.support, + result = !(support.funcNames ? func.name : support.funcDecomp); + + if (!result) { + var source = fnToString.call(func); + if (!support.funcNames) { + result = !reFuncName.test(source); + } + if (!result) { + // Check if `func` references the `this` keyword and store the result. + result = reThis.test(source) || isNative(func); + baseSetData(func, result); + } + } + return result; + } + + /** + * Checks if `value` is a valid array-like index. + * + * @private + * @param {*} value The value to check. + * @param {number} [length=MAX_SAFE_INTEGER] The upper bounds of a valid index. + * @returns {boolean} Returns `true` if `value` is a valid index, else `false`. + */ + function isIndex(value, length) { + value = +value; + length = length == null ? MAX_SAFE_INTEGER : length; + return value > -1 && value % 1 == 0 && value < length; + } + + /** + * Checks if the provided arguments are from an iteratee call. + * + * @private + * @param {*} value The potential iteratee value argument. + * @param {*} index The potential iteratee index or key argument. + * @param {*} object The potential iteratee object argument. + * @returns {boolean} Returns `true` if the arguments are from an iteratee call, else `false`. + */ + function isIterateeCall(value, index, object) { + if (!isObject(object)) { + return false; + } + var type = typeof index; + if (type == 'number') { + var length = object.length, + prereq = isLength(length) && isIndex(index, length); + } else { + prereq = type == 'string' && index in value; + } + return prereq && object[index] === value; + } + + /** + * Checks if `value` is a valid array-like length. + * + * @private + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is a valid length, else `false`. + */ + function isLength(value) { + return typeof value == 'number' && value > -1 && value % 1 == 0 && value <= MAX_SAFE_INTEGER; + } + + /** + * Checks if `value` is suitable for strict equality comparisons, i.e. `===`. + * + * @private + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` if suitable for strict + * equality comparisons, else `false`. + */ + function isStrictComparable(value) { + return value === value && (value === 0 ? ((1 / value) > 0) : !isObject(value)); + } + + /** + * Merges the function metadata of `source` into `data`. + * + * Merging metadata reduces the number of wrappers required to invoke a function. + * This is possible because methods like `_.bind`, `_.curry`, and `_.partial` + * may be applied regardless of execution order. Methods like `_.ary` and `_.rearg` + * augment function arguments, making the order in which they are executed important, + * preventing the merging of metadata. However, we make an exception for a safe + * common case where curried functions have `_.ary` and or `_.rearg` applied. + * + * @private + * @param {Array} data The destination metadata. + * @param {Array} source The source metadata. + * @returns {Array} Returns `data`. + */ + function mergeData(data, source) { + var bitmask = data[1], + srcBitmask = source[1], + newBitmask = bitmask | srcBitmask; + + var arityFlags = ARY_FLAG | REARG_FLAG, + bindFlags = BIND_FLAG | BIND_KEY_FLAG, + comboFlags = arityFlags | bindFlags | CURRY_BOUND_FLAG | CURRY_RIGHT_FLAG; + + var isAry = bitmask & ARY_FLAG && !(srcBitmask & ARY_FLAG), + isRearg = bitmask & REARG_FLAG && !(srcBitmask & REARG_FLAG), + argPos = (isRearg ? data : source)[7], + ary = (isAry ? data : source)[8]; + + var isCommon = !(bitmask >= REARG_FLAG && srcBitmask > bindFlags) && + !(bitmask > bindFlags && srcBitmask >= REARG_FLAG); + + var isCombo = (newBitmask >= arityFlags && newBitmask <= comboFlags) && + (bitmask < REARG_FLAG || ((isRearg || isAry) && argPos.length <= ary)); + + // Exit early if metadata can't be merged. + if (!(isCommon || isCombo)) { + return data; + } + // Use source `thisArg` if available. + if (srcBitmask & BIND_FLAG) { + data[2] = source[2]; + // Set when currying a bound function. + newBitmask |= (bitmask & BIND_FLAG) ? 0 : CURRY_BOUND_FLAG; + } + // Compose partial arguments. + var value = source[3]; + if (value) { + var partials = data[3]; + data[3] = partials ? composeArgs(partials, value, source[4]) : arrayCopy(value); + data[4] = partials ? replaceHolders(data[3], PLACEHOLDER) : arrayCopy(source[4]); + } + // Compose partial right arguments. + value = source[5]; + if (value) { + partials = data[5]; + data[5] = partials ? composeArgsRight(partials, value, source[6]) : arrayCopy(value); + data[6] = partials ? replaceHolders(data[5], PLACEHOLDER) : arrayCopy(source[6]); + } + // Use source `argPos` if available. + value = source[7]; + if (value) { + data[7] = arrayCopy(value); + } + // Use source `ary` if it's smaller. + if (srcBitmask & ARY_FLAG) { + data[8] = data[8] == null ? source[8] : nativeMin(data[8], source[8]); + } + // Use source `arity` if one is not provided. + if (data[9] == null) { + data[9] = source[9]; + } + // Use source `func` and merge bitmasks. + data[0] = source[0]; + data[1] = newBitmask; + + return data; + } + + /** + * A specialized version of `_.pick` that picks `object` properties specified + * by the `props` array. + * + * @private + * @param {Object} object The source object. + * @param {string[]} props The property names to pick. + * @returns {Object} Returns the new object. + */ + function pickByArray(object, props) { + object = toObject(object); + + var index = -1, + length = props.length, + result = {}; + + while (++index < length) { + var key = props[index]; + if (key in object) { + result[key] = object[key]; + } + } + return result; + } + + /** + * A specialized version of `_.pick` that picks `object` properties `predicate` + * returns truthy for. + * + * @private + * @param {Object} object The source object. + * @param {Function} predicate The function invoked per iteration. + * @returns {Object} Returns the new object. + */ + function pickByCallback(object, predicate) { + var result = {}; + baseForIn(object, function(value, key, object) { + if (predicate(value, key, object)) { + result[key] = value; + } + }); + return result; + } + + /** + * Reorder `array` according to the specified indexes where the element at + * the first index is assigned as the first element, the element at + * the second index is assigned as the second element, and so on. + * + * @private + * @param {Array} array The array to reorder. + * @param {Array} indexes The arranged array indexes. + * @returns {Array} Returns `array`. + */ + function reorder(array, indexes) { + var arrLength = array.length, + length = nativeMin(indexes.length, arrLength), + oldArray = arrayCopy(array); + + while (length--) { + var index = indexes[length]; + array[length] = isIndex(index, arrLength) ? oldArray[index] : undefined; + } + return array; + } + + /** + * Sets metadata for `func`. + * + * **Note:** If this function becomes hot, i.e. is invoked a lot in a short + * period of time, it will trip its breaker and transition to an identity function + * to avoid garbage collection pauses in V8. See [V8 issue 2070](https://code.google.com/p/v8/issues/detail?id=2070) + * for more details. + * + * @private + * @param {Function} func The function to associate metadata with. + * @param {*} data The metadata. + * @returns {Function} Returns `func`. + */ + var setData = (function() { + var count = 0, + lastCalled = 0; + + return function(key, value) { + var stamp = now(), + remaining = HOT_SPAN - (stamp - lastCalled); + + lastCalled = stamp; + if (remaining > 0) { + if (++count >= HOT_COUNT) { + return key; + } + } else { + count = 0; + } + return baseSetData(key, value); + }; + }()); + + /** + * A fallback implementation of `_.isPlainObject` which checks if `value` + * is an object created by the `Object` constructor or has a `[[Prototype]]` + * of `null`. + * + * @private + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is a plain object, else `false`. + */ + function shimIsPlainObject(value) { + var Ctor, + support = lodash.support; + + // Exit early for non `Object` objects. + if (!(isObjectLike(value) && objToString.call(value) == objectTag) || + (!hasOwnProperty.call(value, 'constructor') && + (Ctor = value.constructor, typeof Ctor == 'function' && !(Ctor instanceof Ctor)))) { + return false; + } + // IE < 9 iterates inherited properties before own properties. If the first + // iterated property is an object's own property then there are no inherited + // enumerable properties. + var result; + // 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. + baseForIn(value, function(subValue, key) { + result = key; + }); + return typeof result == 'undefined' || hasOwnProperty.call(value, result); + } + + /** + * A fallback implementation of `Object.keys` which creates an array of the + * own enumerable property names of `object`. + * + * @private + * @param {Object} object The object to inspect. + * @returns {Array} Returns the array of property names. + */ + function shimKeys(object) { + var props = keysIn(object), + propsLength = props.length, + length = propsLength && object.length, + support = lodash.support; + + var allowIndexes = length && isLength(length) && + (isArray(object) || (support.nonEnumArgs && isArguments(object))); + + var index = -1, + result = []; + + while (++index < propsLength) { + var key = props[index]; + if ((allowIndexes && isIndex(key, length)) || hasOwnProperty.call(object, key)) { + result.push(key); + } + } + return result; + } + + /** + * Converts `value` to an array-like object if it is not one. + * + * @private + * @param {*} value The value to process. + * @returns {Array|Object} Returns the array-like object. + */ + function toIterable(value) { + if (value == null) { + return []; + } + if (!isLength(value.length)) { + return values(value); + } + return isObject(value) ? value : Object(value); + } + + /** + * Converts `value` to an object if it is not one. + * + * @private + * @param {*} value The value to process. + * @returns {Object} Returns the object. + */ + function toObject(value) { + return isObject(value) ? value : Object(value); + } + + /*------------------------------------------------------------------------*/ + + /** + * Creates an array of elements split into groups the length of `size`. + * If `collection` can't be split evenly, the final chunk will be the remaining + * elements. * * @static * @memberOf _ - * @category Objects - * @param {Mixed} value The value to check. - * @returns {Boolean} Returns `true`, if the `value` is a boolean value, else `false`. + * @category Array + * @param {Array} array The array to process. + * @param {numer} [size=1] The length of each chunk. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {Array} Returns the new array containing chunks. * @example * + * _.chunk(['a', 'b', 'c', 'd'], 2); + * // => [['a', 'b'], ['c', 'd']] + * + * _.chunk(['a', 'b', 'c', 'd'], 3); + * // => [['a', 'b', 'c'], ['d']] + */ + function chunk(array, size, guard) { + if (guard ? isIterateeCall(array, size, guard) : size == null) { + size = 1; + } else { + size = nativeMax(+size || 1, 1); + } + var index = 0, + length = array ? array.length : 0, + resIndex = -1, + result = Array(ceil(length / size)); + + while (index < length) { + result[++resIndex] = baseSlice(array, index, (index += size)); + } + return result; + } + + /** + * Creates an array with all falsey values removed. The values `false`, `null`, + * `0`, `""`, `undefined`, and `NaN` are falsey. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to compact. + * @returns {Array} Returns the new array of filtered values. + * @example + * + * _.compact([0, 1, false, 2, '', 3]); + * // => [1, 2, 3] + */ + function compact(array) { + var index = -1, + length = array ? array.length : 0, + resIndex = -1, + result = []; + + while (++index < length) { + var value = array[index]; + if (value) { + result[++resIndex] = value; + } + } + return result; + } + + /** + * Creates an array excluding all values of the provided arrays using + * `SameValueZero` for equality comparisons. + * + * **Note:** `SameValueZero` comparisons are like strict equality comparisons, + * e.g. `===`, except that `NaN` matches `NaN`. See the + * [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-samevaluezero) + * for more details. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to inspect. + * @param {...Array} [values] The arrays of values to exclude. + * @returns {Array} Returns the new array of filtered values. + * @example + * + * _.difference([1, 2, 3], [5, 2, 10]); + * // => [1, 3] + */ + function difference() { + var index = -1, + length = arguments.length; + + while (++index < length) { + var value = arguments[index]; + if (isArray(value) || isArguments(value)) { + break; + } + } + return baseDifference(value, baseFlatten(arguments, false, true, ++index)); + } + + /** + * Creates a slice of `array` with `n` elements dropped from the beginning. + * + * @static + * @memberOf _ + * @type Function + * @category Array + * @param {Array} array The array to query. + * @param {number} [n=1] The number of elements to drop. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {Array} Returns the slice of `array`. + * @example + * + * _.drop([1, 2, 3]); + * // => [2, 3] + * + * _.drop([1, 2, 3], 2); + * // => [3] + * + * _.drop([1, 2, 3], 5); + * // => [] + * + * _.drop([1, 2, 3], 0); + * // => [1, 2, 3] + */ + function drop(array, n, guard) { + var length = array ? array.length : 0; + if (!length) { + return []; + } + if (guard ? isIterateeCall(array, n, guard) : n == null) { + n = 1; + } + return baseSlice(array, n < 0 ? 0 : n); + } + + /** + * Creates a slice of `array` with `n` elements dropped from the end. + * + * @static + * @memberOf _ + * @type Function + * @category Array + * @param {Array} array The array to query. + * @param {number} [n=1] The number of elements to drop. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {Array} Returns the slice of `array`. + * @example + * + * _.dropRight([1, 2, 3]); + * // => [1, 2] + * + * _.dropRight([1, 2, 3], 2); + * // => [1] + * + * _.dropRight([1, 2, 3], 5); + * // => [] + * + * _.dropRight([1, 2, 3], 0); + * // => [1, 2, 3] + */ + function dropRight(array, n, guard) { + var length = array ? array.length : 0; + if (!length) { + return []; + } + if (guard ? isIterateeCall(array, n, guard) : n == null) { + n = 1; + } + n = length - (+n || 0); + return baseSlice(array, 0, n < 0 ? 0 : n); + } + + /** + * Creates a slice of `array` excluding elements dropped from the end. + * Elements are dropped until `predicate` returns falsey. The predicate is + * bound to `thisArg` and invoked with three arguments; (value, index, array). + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @type Function + * @category Array + * @param {Array} array The array to query. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per element. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {Array} Returns the slice of `array`. + * @example + * + * _.dropRightWhile([1, 2, 3], function(n) { return n > 1; }); + * // => [1] + * + * var users = [ + * { 'user': 'barney', 'status': 'busy', 'active': false }, + * { 'user': 'fred', 'status': 'busy', 'active': true }, + * { 'user': 'pebbles', 'status': 'away', 'active': true } + * ]; + * + * // using the "_.property" callback shorthand + * _.pluck(_.dropRightWhile(users, 'active'), 'user'); + * // => ['barney'] + * + * // using the "_.matches" callback shorthand + * _.pluck(_.dropRightWhile(users, { 'status': 'away' }), 'user'); + * // => ['barney', 'fred'] + */ + function dropRightWhile(array, predicate, thisArg) { + var length = array ? array.length : 0; + if (!length) { + return []; + } + predicate = getCallback(predicate, thisArg, 3); + while (length-- && predicate(array[length], length, array)) {} + return baseSlice(array, 0, length + 1); + } + + /** + * Creates a slice of `array` excluding elements dropped from the beginning. + * Elements are dropped until `predicate` returns falsey. The predicate is + * bound to `thisArg` and invoked with three arguments; (value, index, array). + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @type Function + * @category Array + * @param {Array} array The array to query. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per element. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {Array} Returns the slice of `array`. + * @example + * + * _.dropWhile([1, 2, 3], function(n) { return n < 3; }); + * // => [3] + * + * var users = [ + * { 'user': 'barney', 'status': 'busy', 'active': true }, + * { 'user': 'fred', 'status': 'busy', 'active': false }, + * { 'user': 'pebbles', 'status': 'away', 'active': true } + * ]; + * + * // using the "_.property" callback shorthand + * _.pluck(_.dropWhile(users, 'active'), 'user'); + * // => ['fred', 'pebbles'] + * + * // using the "_.matches" callback shorthand + * _.pluck(_.dropWhile(users, { 'status': 'busy' }), 'user'); + * // => ['pebbles'] + */ + function dropWhile(array, predicate, thisArg) { + var length = array ? array.length : 0; + if (!length) { + return []; + } + var index = -1; + predicate = getCallback(predicate, thisArg, 3); + while (++index < length && predicate(array[index], index, array)) {} + return baseSlice(array, index); + } + + /** + * This method is like `_.find` except that it returns the index of the first + * element `predicate` returns truthy for, instead of the element itself. + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to search. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. If a property name or object is provided it is used to + * create a "_.property" or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {number} Returns the index of the found element, else `-1`. + * @example + * + * var users = [ + * { 'user': 'barney', 'age': 36, 'active': false }, + * { 'user': 'fred', 'age': 40, 'active': true }, + * { 'user': 'pebbles', 'age': 1, 'active': false } + * ]; + * + * _.findIndex(users, function(chr) { return chr.age < 40; }); + * // => 0 + * + * // using the "_.matches" callback shorthand + * _.findIndex(users, { 'age': 1 }); + * // => 2 + * + * // using the "_.property" callback shorthand + * _.findIndex(users, 'active'); + * // => 1 + */ + function findIndex(array, predicate, thisArg) { + var index = -1, + length = array ? array.length : 0; + + predicate = getCallback(predicate, thisArg, 3); + while (++index < length) { + if (predicate(array[index], index, array)) { + return index; + } + } + return -1; + } + + /** + * This method is like `_.findIndex` except that it iterates over elements + * of `collection` from right to left. + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to search. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. If a property name or object is provided it is used to + * create a "_.property" or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {number} Returns the index of the found element, else `-1`. + * @example + * + * var users = [ + * { 'user': 'barney', 'age': 36, 'active': true }, + * { 'user': 'fred', 'age': 40, 'active': false }, + * { 'user': 'pebbles', 'age': 1, 'active': false } + * ]; + * + * _.findLastIndex(users, function(chr) { return chr.age < 40; }); + * // => 2 + * + * // using the "_.matches" callback shorthand + * _.findLastIndex(users, { 'age': 40 }); + * // => 1 + * + * // using the "_.property" callback shorthand + * _.findLastIndex(users, 'active'); + * // => 0 + */ + function findLastIndex(array, predicate, thisArg) { + var length = array ? array.length : 0; + predicate = getCallback(predicate, thisArg, 3); + while (length--) { + if (predicate(array[length], length, array)) { + return length; + } + } + return -1; + } + + /** + * Gets the first element of `array`. + * + * @static + * @memberOf _ + * @alias head + * @category Array + * @param {Array} array The array to query. + * @returns {*} Returns the first element of `array`. + * @example + * + * _.first([1, 2, 3]); + * // => 1 + * + * _.first([]); + * // => undefined + */ + function first(array) { + return array ? array[0] : undefined; + } + + /** + * Flattens a nested array. If `isDeep` is `true` the array is recursively + * flattened, otherwise it is only flattened a single level. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to flatten. + * @param {boolean} [isDeep] Specify a deep flatten. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {Array} Returns the new flattened array. + * @example + * + * _.flatten([1, [2], [3, [[4]]]]); + * // => [1, 2, 3, [[4]]]; + * + * // using `isDeep` + * _.flatten([1, [2], [3, [[4]]]], true); + * // => [1, 2, 3, 4]; + */ + function flatten(array, isDeep, guard) { + var length = array ? array.length : 0; + if (guard && isIterateeCall(array, isDeep, guard)) { + isDeep = false; + } + return length ? baseFlatten(array, isDeep) : []; + } + + /** + * Recursively flattens a nested array. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to recursively flatten. + * @returns {Array} Returns the new flattened array. + * @example + * + * _.flattenDeep([1, [2], [3, [[4]]]]); + * // => [1, 2, 3, 4]; + */ + function flattenDeep(array) { + var length = array ? array.length : 0; + return length ? baseFlatten(array, true) : []; + } + + /** + * Gets the index at which the first occurrence of `value` is found in `array` + * using `SameValueZero` for equality comparisons. If `fromIndex` is negative, + * it is used as the offset from the end of `array`. If `array` is sorted + * providing `true` for `fromIndex` performs a faster binary search. + * + * **Note:** `SameValueZero` comparisons are like strict equality comparisons, + * e.g. `===`, except that `NaN` matches `NaN`. See the + * [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-samevaluezero) + * for more details. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to search. + * @param {*} value The value to search for. + * @param {boolean|number} [fromIndex=0] The index to search from or `true` + * to perform a binary search on a sorted array. + * @returns {number} Returns the index of the matched value, else `-1`. + * @example + * + * _.indexOf([1, 2, 3, 1, 2, 3], 2); + * // => 1 + * + * // using `fromIndex` + * _.indexOf([1, 2, 3, 1, 2, 3], 2, 3); + * // => 4 + * + * // performing a binary search + * _.indexOf([4, 4, 5, 5, 6, 6], 5, true); + * // => 2 + */ + function indexOf(array, value, fromIndex) { + var length = array ? array.length : 0; + if (!length) { + return -1; + } + if (typeof fromIndex == 'number') { + fromIndex = fromIndex < 0 ? nativeMax(length + fromIndex, 0) : (fromIndex || 0); + } else if (fromIndex) { + var index = binaryIndex(array, value), + other = array[index]; + + return (value === value ? value === other : other !== other) ? index : -1; + } + return baseIndexOf(array, value, fromIndex); + } + + /** + * Gets all but the last element of `array`. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to query. + * @returns {Array} Returns the slice of `array`. + * @example + * + * _.initial([1, 2, 3]); + * // => [1, 2] + */ + function initial(array) { + return dropRight(array, 1); + } + + /** + * Creates an array of unique values in all provided arrays using `SameValueZero` + * for equality comparisons. + * + * **Note:** `SameValueZero` comparisons are like strict equality comparisons, + * e.g. `===`, except that `NaN` matches `NaN`. See the + * [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-samevaluezero) + * for more details. + * + * @static + * @memberOf _ + * @category Array + * @param {...Array} [arrays] The arrays to inspect. + * @returns {Array} Returns the new array of shared values. + * @example + * + * _.intersection([1, 2, 3], [5, 2, 1, 4], [2, 1]); + * // => [1, 2] + */ + function intersection() { + var args = [], + argsIndex = -1, + argsLength = arguments.length, + caches = [], + indexOf = getIndexOf(), + isCommon = indexOf == baseIndexOf; + + while (++argsIndex < argsLength) { + var value = arguments[argsIndex]; + if (isArray(value) || isArguments(value)) { + args.push(value); + caches.push(isCommon && value.length >= 120 && createCache(argsIndex && value)); + } + } + argsLength = args.length; + var array = args[0], + index = -1, + length = array ? array.length : 0, + result = [], + seen = caches[0]; + + outer: + while (++index < length) { + value = array[index]; + if ((seen ? cacheIndexOf(seen, value) : indexOf(result, value)) < 0) { + argsIndex = argsLength; + while (--argsIndex) { + var cache = caches[argsIndex]; + if ((cache ? cacheIndexOf(cache, value) : indexOf(args[argsIndex], value)) < 0) { + continue outer; + } + } + if (seen) { + seen.push(value); + } + result.push(value); + } + } + return result; + } + + /** + * Gets the last element of `array`. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to query. + * @returns {*} Returns the last element of `array`. + * @example + * + * _.last([1, 2, 3]); + * // => 3 + */ + function last(array) { + var length = array ? array.length : 0; + return length ? array[length - 1] : undefined; + } + + /** + * This method is like `_.indexOf` except that it iterates over elements of + * `array` from right to left. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to search. + * @param {*} value The value to search for. + * @param {boolean|number} [fromIndex=array.length-1] The index to search from + * or `true` to perform a binary search on a sorted array. + * @returns {number} Returns the index of the matched value, else `-1`. + * @example + * + * _.lastIndexOf([1, 2, 3, 1, 2, 3], 2); + * // => 4 + * + * // using `fromIndex` + * _.lastIndexOf([1, 2, 3, 1, 2, 3], 2, 3); + * // => 1 + * + * // performing a binary search + * _.lastIndexOf([4, 4, 5, 5, 6, 6], 5, true); + * // => 3 + */ + function lastIndexOf(array, value, fromIndex) { + var length = array ? array.length : 0; + if (!length) { + return -1; + } + var index = length; + if (typeof fromIndex == 'number') { + index = (fromIndex < 0 ? nativeMax(length + fromIndex, 0) : nativeMin(fromIndex || 0, length - 1)) + 1; + } else if (fromIndex) { + index = binaryIndex(array, value, true) - 1; + var other = array[index]; + return (value === value ? value === other : other !== other) ? index : -1; + } + if (value !== value) { + return indexOfNaN(array, index, true); + } + while (index--) { + if (array[index] === value) { + return index; + } + } + return -1; + } + + /** + * Removes all provided values from `array` using `SameValueZero` for equality + * comparisons. + * + * **Notes:** + * - Unlike `_.without`, this method mutates `array`. + * - `SameValueZero` comparisons are like strict equality comparisons, e.g. `===`, + * except that `NaN` matches `NaN`. See the [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-samevaluezero) + * for more details. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to modify. + * @param {...*} [values] 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() { + var array = arguments[0]; + if (!(array && array.length)) { + return array; + } + var index = 0, + indexOf = getIndexOf(), + length = arguments.length; + + while (++index < length) { + var fromIndex = 0, + value = arguments[index]; + + while ((fromIndex = indexOf(array, value, fromIndex)) > -1) { + splice.call(array, fromIndex, 1); + } + } + return array; + } + + /** + * Removes elements from `array` corresponding to the given indexes and returns + * an array of the removed elements. Indexes may be specified as an array of + * indexes or as individual arguments. + * + * **Note:** Unlike `_.at`, this method mutates `array`. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to modify. + * @param {...(number|number[])} [indexes] The indexes of elements to remove, + * specified as individual indexes or arrays of indexes. + * @returns {Array} Returns the new array of removed elements. + * @example + * + * var array = [5, 10, 15, 20]; + * var evens = _.pullAt(array, [1, 3]); + * + * console.log(array); + * // => [5, 15] + * + * console.log(evens); + * // => [10, 20] + */ + function pullAt(array) { + return basePullAt(array || [], baseFlatten(arguments, false, false, 1)); + } + + /** + * Removes all elements from `array` that `predicate` returns truthy for + * and returns an array of the removed elements. The predicate is bound to + * `thisArg` and invoked with three arguments; (value, index, array). + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * **Note:** Unlike `_.filter`, this method mutates `array`. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to modify. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. If a property name or object is provided it is used to + * create a "_.property" or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {Array} Returns the new array of removed elements. + * @example + * + * var array = [1, 2, 3, 4]; + * var evens = _.remove(array, function(n) { return n % 2 == 0; }); + * + * console.log(array); + * // => [1, 3] + * + * console.log(evens); + * // => [2, 4] + */ + function remove(array, predicate, thisArg) { + var index = -1, + length = array ? array.length : 0, + result = []; + + predicate = getCallback(predicate, thisArg, 3); + while (++index < length) { + var value = array[index]; + if (predicate(value, index, array)) { + result.push(value); + splice.call(array, index--, 1); + length--; + } + } + return result; + } + + /** + * Gets all but the first element of `array`. + * + * @static + * @memberOf _ + * @alias tail + * @category Array + * @param {Array} array The array to query. + * @returns {Array} Returns the slice of `array`. + * @example + * + * _.rest([1, 2, 3]); + * // => [2, 3] + */ + function rest(array) { + return drop(array, 1); + } + + /** + * Creates a slice of `array` from `start` up to, but not including, `end`. + * + * **Note:** This function is used instead of `Array#slice` to support node + * lists in IE < 9 and to ensure dense arrays are returned. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to slice. + * @param {number} [start=0] The start position. + * @param {number} [end=array.length] The end position. + * @returns {Array} Returns the slice of `array`. + */ + function slice(array, start, end) { + var length = array ? array.length : 0; + if (!length) { + return []; + } + if (end && typeof end != 'number' && isIterateeCall(array, start, end)) { + start = 0; + end = length; + } + return baseSlice(array, start, end); + } + + /** + * Uses a binary search to determine the lowest index at which `value` should + * be inserted into `array` in order to maintain its sort order. If an iteratee + * function is provided it is invoked for `value` and each element of `array` + * to compute their sort ranking. The iteratee is bound to `thisArg` and + * invoked with one argument; (value). + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The sorted array to inspect. + * @param {*} value The value to evaluate. + * @param {Function|Object|string} [iteratee=_.identity] The function invoked + * per iteration. If a property name or object is provided it is used to + * create a "_.property" or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {number} Returns the index at which `value` should be inserted + * into `array`. + * @example + * + * _.sortedIndex([30, 50], 40); + * // => 1 + * + * _.sortedIndex([4, 4, 5, 5, 6, 6], 5); + * // => 2 + * + * var dict = { 'data': { 'thirty': 30, 'forty': 40, 'fifty': 50 } }; + * + * // using an iteratee function + * _.sortedIndex(['thirty', 'fifty'], 'forty', function(word) { + * return this.data[word]; + * }, dict); + * // => 1 + * + * // using the "_.property" callback shorthand + * _.sortedIndex([{ 'x': 30 }, { 'x': 50 }], { 'x': 40 }, 'x'); + * // => 1 + */ + function sortedIndex(array, value, iteratee, thisArg) { + var func = getCallback(iteratee); + return (func === baseCallback && iteratee == null) + ? binaryIndex(array, value) + : binaryIndexBy(array, value, func(iteratee, thisArg, 1)); + } + + /** + * This method is like `_.sortedIndex` except that it returns the highest + * index at which `value` should be inserted into `array` in order to + * maintain its sort order. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The sorted array to inspect. + * @param {*} value The value to evaluate. + * @param {Function|Object|string} [iteratee=_.identity] The function invoked + * per iteration. If a property name or object is provided it is used to + * create a "_.property" or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {number} Returns the index at which `value` should be inserted + * into `array`. + * @example + * + * _.sortedLastIndex([4, 4, 5, 5, 6, 6], 5); + * // => 4 + */ + function sortedLastIndex(array, value, iteratee, thisArg) { + var func = getCallback(iteratee); + return (func === baseCallback && iteratee == null) + ? binaryIndex(array, value, true) + : binaryIndexBy(array, value, func(iteratee, thisArg, 1), true); + } + + /** + * Creates a slice of `array` with `n` elements taken from the beginning. + * + * @static + * @memberOf _ + * @type Function + * @category Array + * @param {Array} array The array to query. + * @param {number} [n=1] The number of elements to take. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {Array} Returns the slice of `array`. + * @example + * + * _.take([1, 2, 3]); + * // => [1] + * + * _.take([1, 2, 3], 2); + * // => [1, 2] + * + * _.take([1, 2, 3], 5); + * // => [1, 2, 3] + * + * _.take([1, 2, 3], 0); + * // => [] + */ + function take(array, n, guard) { + var length = array ? array.length : 0; + if (!length) { + return []; + } + if (guard ? isIterateeCall(array, n, guard) : n == null) { + n = 1; + } + return baseSlice(array, 0, n < 0 ? 0 : n); + } + + /** + * Creates a slice of `array` with `n` elements taken from the end. + * + * @static + * @memberOf _ + * @type Function + * @category Array + * @param {Array} array The array to query. + * @param {number} [n=1] The number of elements to take. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {Array} Returns the slice of `array`. + * @example + * + * _.takeRight([1, 2, 3]); + * // => [3] + * + * _.takeRight([1, 2, 3], 2); + * // => [2, 3] + * + * _.takeRight([1, 2, 3], 5); + * // => [1, 2, 3] + * + * _.takeRight([1, 2, 3], 0); + * // => [] + */ + function takeRight(array, n, guard) { + var length = array ? array.length : 0; + if (!length) { + return []; + } + if (guard ? isIterateeCall(array, n, guard) : n == null) { + n = 1; + } + n = length - (+n || 0); + return baseSlice(array, n < 0 ? 0 : n); + } + + /** + * Creates a slice of `array` with elements taken from the end. Elements are + * taken until `predicate` returns falsey. The predicate is bound to `thisArg` + * and invoked with three arguments; (value, index, array). + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @type Function + * @category Array + * @param {Array} array The array to query. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per element. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {Array} Returns the slice of `array`. + * @example + * + * _.takeRightWhile([1, 2, 3], function(n) { return n > 1; }); + * // => [2, 3] + * + * var users = [ + * { 'user': 'barney', 'status': 'busy', 'active': false }, + * { 'user': 'fred', 'status': 'busy', 'active': true }, + * { 'user': 'pebbles', 'status': 'away', 'active': true } + * ]; + * + * // using the "_.property" callback shorthand + * _.pluck(_.takeRightWhile(users, 'active'), 'user'); + * // => ['fred', 'pebbles'] + * + * // using the "_.matches" callback shorthand + * _.pluck(_.takeRightWhile(users, { 'status': 'away' }), 'user'); + * // => ['pebbles'] + */ + function takeRightWhile(array, predicate, thisArg) { + var length = array ? array.length : 0; + if (!length) { + return []; + } + predicate = getCallback(predicate, thisArg, 3); + while (length-- && predicate(array[length], length, array)) {} + return baseSlice(array, length + 1); + } + + /** + * Creates a slice of `array` with elements taken from the beginning. Elements + * are taken until `predicate` returns falsey. The predicate is bound to + * `thisArg` and invoked with three arguments; (value, index, array). + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @type Function + * @category Array + * @param {Array} array The array to query. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per element. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {Array} Returns the slice of `array`. + * @example + * + * _.takeWhile([1, 2, 3], function(n) { return n < 3; }); + * // => [1, 2] + * + * var users = [ + * { 'user': 'barney', 'status': 'busy', 'active': true }, + * { 'user': 'fred', 'status': 'busy', 'active': false }, + * { 'user': 'pebbles', 'status': 'away', 'active': true } + * ]; + * + * // using the "_.property" callback shorthand + * _.pluck(_.takeWhile(users, 'active'), 'user'); + * // => ['barney'] + * + * // using the "_.matches" callback shorthand + * _.pluck(_.takeWhile(users, { 'status': 'busy' }), 'user'); + * // => ['barney', 'fred'] + */ + function takeWhile(array, predicate, thisArg) { + var length = array ? array.length : 0; + if (!length) { + return []; + } + var index = -1; + predicate = getCallback(predicate, thisArg, 3); + while (++index < length && predicate(array[index], index, array)) {} + return baseSlice(array, 0, index); + } + + /** + * Creates an array of unique values, in order, of the provided arrays using + * `SameValueZero` for equality comparisons. + * + * **Note:** `SameValueZero` comparisons are like strict equality comparisons, + * e.g. `===`, except that `NaN` matches `NaN`. See the + * [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-samevaluezero) + * for more details. + * + * @static + * @memberOf _ + * @category Array + * @param {...Array} [arrays] The arrays to inspect. + * @returns {Array} Returns the new array of combined values. + * @example + * + * _.union([1, 2, 3], [5, 2, 1, 4], [2, 1]); + * // => [1, 2, 3, 5, 4] + */ + function union() { + return baseUniq(baseFlatten(arguments, false, true)); + } + + /** + * Creates a duplicate-value-free version of an array using `SameValueZero` + * for equality comparisons. Providing `true` for `isSorted` performs a faster + * search algorithm for sorted arrays. If an iteratee function is provided it + * is invoked for each value in the array to generate the criterion by which + * uniqueness is computed. The `iteratee` is bound to `thisArg` and invoked + * with three arguments; (value, index, array). + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * **Note:** `SameValueZero` comparisons are like strict equality comparisons, + * e.g. `===`, except that `NaN` matches `NaN`. See the + * [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-samevaluezero) + * for more details. + * + * @static + * @memberOf _ + * @alias unique + * @category Array + * @param {Array} array The array to inspect. + * @param {boolean} [isSorted] Specify the array is sorted. + * @param {Function|Object|string} [iteratee] The function invoked per iteration. + * If a property name or object is provided it is used to create a "_.property" + * or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Array} Returns the new duplicate-value-free array. + * @example + * + * _.uniq([1, 2, 1]); + * // => [1, 2] + * + * // using `isSorted` + * _.uniq([1, 1, 2], true); + * // => [1, 2] + * + * // using an iteratee function + * _.uniq([1, 2.5, 1.5, 2], function(n) { return this.floor(n); }, Math); + * // => [1, 2.5] + * + * // using the "_.property" callback shorthand + * _.uniq([{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }], 'x'); + * // => [{ 'x': 1 }, { 'x': 2 }] + */ + function uniq(array, isSorted, iteratee, thisArg) { + var length = array ? array.length : 0; + if (!length) { + return []; + } + // Juggle arguments. + if (typeof isSorted != 'boolean' && isSorted != null) { + thisArg = iteratee; + iteratee = isIterateeCall(array, isSorted, thisArg) ? null : isSorted; + isSorted = false; + } + var func = getCallback(); + if (!(func === baseCallback && iteratee == null)) { + iteratee = func(iteratee, thisArg, 3); + } + return (isSorted && getIndexOf() == baseIndexOf) + ? sortedUniq(array, iteratee) + : baseUniq(array, iteratee); + } + + /** + * This method is like `_.zip` except that it accepts an array of grouped + * elements and creates an array regrouping the elements to their pre-`_.zip` + * configuration. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array of grouped elements to process. + * @returns {Array} Returns the new array of regrouped elements. + * @example + * + * var zipped = _.zip(['fred', 'barney'], [30, 40], [true, false]); + * // => [['fred', 30, true], ['barney', 40, false]] + * + * _.unzip(zipped); + * // => [['fred', 'barney'], [30, 40], [true, false]] + */ + function unzip(array) { + var index = -1, + length = (array && array.length && arrayMax(arrayMap(array, getLength))) >>> 0, + result = Array(length); + + while (++index < length) { + result[index] = arrayMap(array, baseProperty(index)); + } + return result; + } + + /** + * Creates an array excluding all provided values using `SameValueZero` for + * equality comparisons. + * + * **Note:** `SameValueZero` comparisons are like strict equality comparisons, + * e.g. `===`, except that `NaN` matches `NaN`. See the + * [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-samevaluezero) + * for more details. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to filter. + * @param {...*} [values] The values to exclude. + * @returns {Array} Returns the new array of filtered values. + * @example + * + * _.without([1, 2, 1, 0, 3, 1, 4], 0, 1); + * // => [2, 3, 4] + */ + function without(array) { + return baseDifference(array, baseSlice(arguments, 1)); + } + + /** + * Creates an array that is the symmetric difference of the provided arrays. + * See [Wikipedia](https://en.wikipedia.org/wiki/Symmetric_difference) for + * more details. + * + * @static + * @memberOf _ + * @category Array + * @param {...Array} [arrays] The arrays to inspect. + * @returns {Array} Returns the new 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 + ? baseDifference(result, array).concat(baseDifference(array, result)) + : array; + } + } + return result ? baseUniq(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 _ + * @category Array + * @param {...Array} [arrays] The arrays to process. + * @returns {Array} Returns the new array of grouped elements. + * @example + * + * _.zip(['fred', 'barney'], [30, 40], [true, false]); + * // => [['fred', 30, true], ['barney', 40, false]] + */ + function zip() { + var length = arguments.length, + array = Array(length); + + while (length--) { + array[length] = arguments[length]; + } + return unzip(array); + } + + /** + * Creates an object composed from arrays of property names and values. Provide + * either a single two dimensional array, e.g. `[[key1, value1], [key2, value2]]` + * or two arrays, one of property names and one of corresponding values. + * + * @static + * @memberOf _ + * @alias object + * @category Array + * @param {Array} props The property names. + * @param {Array} [values=[]] The property values. + * @returns {Object} Returns the new object. + * @example + * + * _.zipObject(['fred', 'barney'], [30, 40]); + * // => { 'fred': 30, 'barney': 40 } + */ + function zipObject(props, values) { + var index = -1, + length = props ? props.length : 0, + result = {}; + + if (length && !values && !isArray(props[0])) { + values = []; + } + while (++index < length) { + var key = props[index]; + if (values) { + result[key] = values[index]; + } else if (key) { + result[key[0]] = key[1]; + } + } + return result; + } + + /*------------------------------------------------------------------------*/ + + /** + * Creates a `lodash` object that wraps `value` with explicit method + * chaining enabled. + * + * @static + * @memberOf _ + * @category Chain + * @param {*} value The value to wrap. + * @returns {Object} Returns the new `lodash` object. + * @example + * + * var users = [ + * { 'user': 'barney', 'age': 36 }, + * { 'user': 'fred', 'age': 40 }, + * { 'user': 'pebbles', 'age': 1 } + * ]; + * + * var youngest = _.chain(users) + * .sortBy('age') + * .map(function(chr) { return chr.user + ' is ' + chr.age; }) + * .first() + * .value(); + * // => 'pebbles is 1' + */ + function chain(value) { + var result = lodash(value); + result.__chain__ = true; + return result; + } + + /** + * This method invokes `interceptor` and returns `value`. The interceptor is + * bound to `thisArg` and invoked with one argument; (value). The purpose of + * this method is to "tap into" a method chain in order to perform operations + * on intermediate results within the chain. + * + * @static + * @memberOf _ + * @category Chain + * @param {*} value The value to provide to `interceptor`. + * @param {Function} interceptor The function to invoke. + * @param {*} [thisArg] The `this` binding of `interceptor`. + * @returns {*} Returns `value`. + * @example + * + * _([1, 2, 3]) + * .tap(function(array) { array.pop(); }) + * .reverse() + * .value(); + * // => [2, 1] + */ + function tap(value, interceptor, thisArg) { + interceptor.call(thisArg, value); + return value; + } + + /** + * This method is like `_.tap` except that it returns the result of `interceptor`. + * + * @static + * @memberOf _ + * @category Chain + * @param {*} value The value to provide to `interceptor`. + * @param {Function} interceptor The function to invoke. + * @param {*} [thisArg] The `this` binding of `interceptor`. + * @returns {*} Returns the result of `interceptor`. + * @example + * + * _([1, 2, 3]) + * .last() + * .thru(function(value) { return [value]; }) + * .value(); + * // => [3] + */ + function thru(value, interceptor, thisArg) { + return interceptor.call(thisArg, value); + } + + /** + * Enables explicit method chaining on the wrapper object. + * + * @name chain + * @memberOf _ + * @category Chain + * @returns {*} Returns the `lodash` object. + * @example + * + * var users = [ + * { 'user': 'barney', 'age': 36 }, + * { 'user': 'fred', 'age': 40 } + * ]; + * + * // without explicit chaining + * _(users).first(); + * // => { 'user': 'barney', 'age': 36 } + * + * // with explicit chaining + * _(users).chain() + * .first() + * .pick('user') + * .value(); + * // => { 'user': 'barney' } + */ + function wrapperChain() { + return chain(this); + } + + /** + * Reverses the wrapped array so the first element becomes the last, the + * second element becomes the second to last, and so on. + * + * **Note:** This method mutates the wrapped array. + * + * @name reverse + * @memberOf _ + * @category Chain + * @returns {Object} Returns the new reversed `lodash` object. + * @example + * + * var array = [1, 2, 3]; + * + * _(array).reverse().value() + * // => [3, 2, 1] + * + * console.log(array); + * // => [3, 2, 1] + */ + function wrapperReverse() { + var value = this.__wrapped__; + if (value instanceof LazyWrapper) { + if (this.__actions__.length) { + value = new LazyWrapper(this); + } + return new LodashWrapper(value.reverse()); + } + return this.thru(function(value) { + return value.reverse(); + }); + } + + /** + * Produces the result of coercing the unwrapped value to a string. + * + * @name toString + * @memberOf _ + * @category Chain + * @returns {string} Returns the coerced string value. + * @example + * + * _([1, 2, 3]).toString(); + * // => '1,2,3' + */ + function wrapperToString() { + return (this.value() + ''); + } + + /** + * Executes the chained sequence to extract the unwrapped value. + * + * @name value + * @memberOf _ + * @alias toJSON, valueOf + * @category Chain + * @returns {*} Returns the resolved unwrapped value. + * @example + * + * _([1, 2, 3]).value(); + * // => [1, 2, 3] + */ + function wrapperValue() { + return baseWrapperValue(this.__wrapped__, this.__actions__); + } + + /*------------------------------------------------------------------------*/ + + /** + * Creates an array of elements corresponding to the given keys, or indexes, + * of `collection`. Keys may be specified as individual arguments or as arrays + * of keys. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {...(number|number[]|string|string[])} [props] The property names + * or indexes of elements to pick, specified individually or in arrays. + * @returns {Array} Returns the new array of picked elements. + * @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 length = collection ? collection.length : 0; + if (isLength(length)) { + collection = toIterable(collection); + } + return baseAt(collection, baseFlatten(arguments, false, false, 1)); + } + + /** + * Checks if `value` is in `collection` using `SameValueZero` for equality + * comparisons. If `fromIndex` is negative, it is used as the offset from + * the end of `collection`. + * + * **Note:** `SameValueZero` comparisons are like strict equality comparisons, + * e.g. `===`, except that `NaN` matches `NaN`. See the + * [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-samevaluezero) + * for more details. + * + * @static + * @memberOf _ + * @alias contains, include + * @category Collection + * @param {Array|Object|string} collection The collection to search. + * @param {*} target The value to search for. + * @param {number} [fromIndex=0] The index to search from. + * @returns {boolean} Returns `true` if a matching element is found, else `false`. + * @example + * + * _.includes([1, 2, 3], 1); + * // => true + * + * _.includes([1, 2, 3], 1, 2); + * // => false + * + * _.includes({ 'user': 'fred', 'age': 40 }, 'fred'); + * // => true + * + * _.includes('pebbles', 'eb'); + * // => true + */ + function includes(collection, target, fromIndex) { + var length = collection ? collection.length : 0; + if (!isLength(length)) { + collection = values(collection); + length = collection.length; + } + if (!length) { + return false; + } + if (typeof fromIndex == 'number') { + fromIndex = fromIndex < 0 ? nativeMax(length + fromIndex, 0) : (fromIndex || 0); + } else { + fromIndex = 0; + } + return (typeof collection == 'string' || !isArray(collection) && isString(collection)) + ? (fromIndex < length && collection.indexOf(target, fromIndex) > -1) + : (getIndexOf(collection, target, fromIndex) > -1); + } + + /** + * Creates an object composed of keys generated from the results of running + * each element of `collection` through `iteratee`. The corresponding value + * of each key is the number of times the key was returned by `iteratee`. + * The `iteratee` is bound to `thisArg` and invoked with three arguments; + * (value, index|key, collection). + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [iteratee=_.identity] The function invoked + * per iteration. If a property name or object is provided it is used to + * create a "_.property" or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Object} Returns the composed aggregate object. + * @example + * + * _.countBy([4.3, 6.1, 6.4], function(n) { return Math.floor(n); }); + * // => { '4': 1, '6': 2 } + * + * _.countBy([4.3, 6.1, 6.4], function(n) { return this.floor(n); }, 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 `predicate` returns truthy for **all** elements of `collection`. + * The predicate is bound to `thisArg` and invoked with three arguments; + * (value, index|key, collection). + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @alias all + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. If a property name or object is provided it is used to + * create a "_.property" or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {boolean} Returns `true` if all elements pass the predicate check, + * else `false`. + * @example + * + * _.every([true, 1, null, 'yes']); + * // => false + * + * var users = [ + * { 'user': 'barney', 'age': 36 }, + * { 'user': 'fred', 'age': 40 } + * ]; + * + * // using the "_.property" callback shorthand + * _.every(users, 'age'); + * // => true + * + * // using the "_.matches" callback shorthand + * _.every(users, { 'age': 36 }); + * // => false + */ + function every(collection, predicate, thisArg) { + var func = isArray(collection) ? arrayEvery : baseEvery; + if (typeof predicate != 'function' || typeof thisArg != 'undefined') { + predicate = getCallback(predicate, thisArg, 3); + } + return func(collection, predicate); + } + + /** + * Iterates over elements of `collection`, returning an array of all elements + * `predicate` returns truthy for. The predicate is bound to `thisArg` and + * invoked with three arguments; (value, index|key, collection). + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @alias select + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. If a property name or object is provided it is used to + * create a "_.property" or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {Array} Returns the new filtered array. + * @example + * + * var evens = _.filter([1, 2, 3, 4], function(n) { return n % 2 == 0; }); + * // => [2, 4] + * + * var users = [ + * { 'user': 'barney', 'age': 36, 'active': false }, + * { 'user': 'fred', 'age': 40, 'active': true } + * ]; + * + * // using the "_.property" callback shorthand + * _.pluck(_.filter(users, 'active'), 'user'); + * // => ['fred'] + * + * // using the "_.matches" callback shorthand + * _.pluck(_.filter(users, { 'age': 36 }), 'user'); + * // => ['barney'] + */ + function filter(collection, predicate, thisArg) { + var func = isArray(collection) ? arrayFilter : baseFilter; + predicate = getCallback(predicate, thisArg, 3); + return func(collection, predicate); + } + + /** + * Iterates over elements of `collection`, returning the first element + * `predicate` returns truthy for. The predicate is bound to `thisArg` and + * invoked with three arguments; (value, index|key, collection). + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @alias detect + * @category Collection + * @param {Array|Object|string} collection The collection to search. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. If a property name or object is provided it is used to + * create a "_.property" or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {*} Returns the matched element, else `undefined`. + * @example + * + * var users = [ + * { 'user': 'barney', 'age': 36, 'active': false }, + * { 'user': 'fred', 'age': 40, 'active': true }, + * { 'user': 'pebbles', 'age': 1, 'active': false } + * ]; + * + * _.result(_.find(users, function(chr) { return chr.age < 40; }), 'user'); + * // => 'barney' + * + * // using the "_.matches" callback shorthand + * _.result(_.find(users, { 'age': 1 }), 'user'); + * // => 'pebbles' + * + * // using the "_.property" callback shorthand + * _.result(_.find(users, 'active'), 'user'); + * // => 'fred' + */ + function find(collection, predicate, thisArg) { + if (isArray(collection)) { + var index = findIndex(collection, predicate, thisArg); + return index > -1 ? collection[index] : undefined; + } + predicate = getCallback(predicate, thisArg, 3); + return baseFind(collection, predicate, baseEach); + } + + /** + * This method is like `_.find` except that it iterates over elements of + * `collection` from right to left. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to search. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. If a property name or object is provided it is used to + * create a "_.property" or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {*} Returns the matched element, else `undefined`. + * @example + * + * _.findLast([1, 2, 3, 4], function(n) { return n % 2 == 1; }); + * // => 3 + */ + function findLast(collection, predicate, thisArg) { + predicate = getCallback(predicate, thisArg, 3); + return baseFind(collection, predicate, baseEachRight); + } + + /** + * Performs a deep comparison between each element in `collection` and the + * source object, returning the first element that has equivalent property + * values. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to search. + * @param {Object} source The object of property values to match. + * @returns {*} Returns the matched element, else `undefined`. + * @example + * + * var users = [ + * { 'user': 'barney', 'age': 36, 'status': 'busy' }, + * { 'user': 'fred', 'age': 40, 'status': 'busy' } + * ]; + * + * _.result(_.findWhere(users, { 'status': 'busy' }), 'user'); + * // => 'barney' + * + * _.result(_.findWhere(users, { 'age': 40 }), 'user'); + * // => 'fred' + */ + function findWhere(collection, source) { + return find(collection, matches(source)); + } + + /** + * Iterates over elements of `collection` invoking `iteratee` for each element. + * The `iteratee` is bound to `thisArg` and invoked with three arguments; + * (value, index|key, collection). Iterator functions 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 Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Array|Object|string} Returns `collection`. + * @example + * + * _([1, 2, 3]).forEach(function(n) { console.log(n); }).value(); + * // => logs each value from left to right and returns the array + * + * _.forEach({ 'one': 1, 'two': 2, 'three': 3 }, function(n, key) { console.log(n, key); }); + * // => logs each value-key pair and returns the object (iteration order is not guaranteed) + */ + function forEach(collection, iteratee, thisArg) { + return (typeof iteratee == 'function' && typeof thisArg == 'undefined' && isArray(collection)) + ? arrayEach(collection, iteratee) + : baseEach(collection, bindCallback(iteratee, thisArg, 3)); + } + + /** + * This method is like `_.forEach` except that it iterates over elements of + * `collection` from right to left. + * + * @static + * @memberOf _ + * @alias eachRight + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Array|Object|string} Returns `collection`. + * @example + * + * _([1, 2, 3]).forEachRight(function(n) { console.log(n); }).join(','); + * // => logs each value from right to left and returns the array + */ + function forEachRight(collection, iteratee, thisArg) { + return (typeof iteratee == 'function' && typeof thisArg == 'undefined' && isArray(collection)) + ? arrayEachRight(collection, iteratee) + : baseEachRight(collection, bindCallback(iteratee, thisArg, 3)); + } + + /** + * Creates an object composed of keys generated from the results of running + * each element of `collection` through `iteratee`. The corresponding value + * of each key is an array of the elements responsible for generating the key. + * The `iteratee` is bound to `thisArg` and invoked with three arguments; + * (value, index|key, collection). + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [iteratee=_.identity] The function invoked + * per iteration. If a property name or object is provided it is used to + * create a "_.property" or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Object} Returns the composed aggregate object. + * @example + * + * _.groupBy([4.2, 6.1, 6.4], function(n) { return Math.floor(n); }); + * // => { '4': [4.2], '6': [6.1, 6.4] } + * + * _.groupBy([4.2, 6.1, 6.4], function(n) { return this.floor(n); }, Math); + * // => { '4': [4.2], '6': [6.1, 6.4] } + * + * // using the "_.property" callback shorthand + * _.groupBy(['one', 'two', 'three'], 'length'); + * // => { '3': ['one', 'two'], '5': ['three'] } + */ + var groupBy = createAggregator(function(result, value, key) { + if (hasOwnProperty.call(result, key)) { + result[key].push(value); + } else { + result[key] = [value]; + } + }); + + /** + * Creates an object composed of keys generated from the results of running + * each element of `collection` through `iteratee`. The corresponding value + * of each key is the last element responsible for generating the key. The + * iteratee function is bound to `thisArg` and invoked with three arguments; + * (value, index|key, collection). + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [iteratee=_.identity] The function invoked + * per iteration. If a property name or object is provided it is used to + * create a "_.property" or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Object} Returns the composed aggregate object. + * @example + * + * var keyData = [ + * { 'dir': 'left', 'code': 97 }, + * { 'dir': 'right', 'code': 100 } + * ]; + * + * _.indexBy(keyData, 'dir'); + * // => { 'left': { 'dir': 'left', 'code': 97 }, 'right': { 'dir': 'right', 'code': 100 } } + * + * _.indexBy(keyData, function(object) { return String.fromCharCode(object.code); }); + * // => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } } + * + * _.indexBy(keyData, function(object) { return this.fromCharCode(object.code); }, String); + * // => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } } + */ + var indexBy = createAggregator(function(result, value, key) { + result[key] = value; + }); + + /** + * Invokes the method named by `methodName` on each element in `collection`, + * returning an array of the results of each invoked method. Any additional + * arguments are provided to each invoked method. If `methodName` is a function + * it is invoked for, and `this` bound to, each element in `collection`. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|string} methodName The name of the method to invoke or + * the function invoked per iteration. + * @param {...*} [args] The arguments to invoke the method with. + * @returns {Array} Returns the array of results. + * @example + * + * _.invoke([[5, 1, 7], [3, 2, 1]], 'sort'); + * // => [[1, 5, 7], [1, 2, 3]] + * + * _.invoke([123, 456], String.prototype.split, ''); + * // => [['1', '2', '3'], ['4', '5', '6']] + */ + function invoke(collection, methodName) { + return baseInvoke(collection, methodName, baseSlice(arguments, 2)); + } + + /** + * Creates an array of values by running each element in `collection` through + * `iteratee`. The `iteratee` is bound to `thisArg` and invoked with three + * arguments; (value, index|key, collection). + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @alias collect + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [iteratee=_.identity] The function invoked + * per iteration. If a property name or object is provided it is used to + * create a "_.property" or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Array} Returns the new mapped array. + * @example + * + * _.map([1, 2, 3], function(n) { return n * 3; }); + * // => [3, 6, 9] + * + * _.map({ 'one': 1, 'two': 2, 'three': 3 }, function(n) { return n * 3; }); + * // => [3, 6, 9] (iteration order is not guaranteed) + * + * var users = [ + * { 'user': 'barney' }, + * { 'user': 'fred' } + * ]; + * + * // using the "_.property" callback shorthand + * _.map(users, 'user'); + * // => ['barney', 'fred'] + */ + function map(collection, iteratee, thisArg) { + var func = isArray(collection) ? arrayMap : baseMap; + iteratee = getCallback(iteratee, thisArg, 3); + return func(collection, iteratee); + } + + /** + * Gets the maximum value of `collection`. If `collection` is empty or falsey + * `-Infinity` is returned. If an iteratee function is provided it is invoked + * for each value in `collection` to generate the criterion by which the value + * is ranked. The `iteratee` is bound to `thisArg` and invoked with three + * arguments; (value, index, collection). + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [iteratee] The function invoked per iteration. + * If a property name or object is provided it is used to create a "_.property" + * or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {*} Returns the maximum value. + * @example + * + * _.max([4, 2, 8, 6]); + * // => 8 + * + * _.max([]); + * // => -Infinity + * + * var users = [ + * { 'user': 'barney', 'age': 36 }, + * { 'user': 'fred', 'age': 40 } + * ]; + * + * _.max(users, function(chr) { return chr.age; }); + * // => { 'user': 'fred', 'age': 40 }; + * + * // using the "_.property" callback shorthand + * _.max(users, 'age'); + * // => { 'user': 'fred', 'age': 40 }; + */ + var max = createExtremum(arrayMax); + + /** + * Gets the minimum value of `collection`. If `collection` is empty or falsey + * `Infinity` is returned. If an iteratee function is provided it is invoked + * for each value in `collection` to generate the criterion by which the value + * is ranked. The `iteratee` is bound to `thisArg` and invoked with three + * arguments; (value, index, collection). + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [iteratee] The function invoked per iteration. + * If a property name or object is provided it is used to create a "_.property" + * or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {*} Returns the minimum value. + * @example + * + * _.min([4, 2, 8, 6]); + * // => 2 + * + * _.min([]); + * // => Infinity + * + * var users = [ + * { 'user': 'barney', 'age': 36 }, + * { 'user': 'fred', 'age': 40 } + * ]; + * + * _.min(users, function(chr) { return chr.age; }); + * // => { 'user': 'barney', 'age': 36 }; + * + * // using the "_.property" callback shorthand + * _.min(users, 'age'); + * // => { 'user': 'barney', 'age': 36 }; + */ + var min = createExtremum(arrayMin, true); + + /** + * Creates an array of elements split into two groups, the first of which + * contains elements `predicate` returns truthy for, while the second of which + * contains elements `predicate` returns falsey for. The predicate is bound + * to `thisArg` and invoked with three arguments; (value, index|key, collection). + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. If a property name or object is provided it is used to + * create a "_.property" or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {Array} Returns the array of grouped elements. + * @example + * + * _.partition([1, 2, 3], function(n) { return n % 2; }); + * // => [[1, 3], [2]] + * + * _.partition([1.2, 2.3, 3.4], function(n) { return this.floor(n) % 2; }, Math); + * // => [[1, 3], [2]] + * + * var users = [ + * { 'user': 'barney', 'age': 36, 'active': false }, + * { 'user': 'fred', 'age': 40, 'active': true }, + * { 'user': 'pebbles', 'age': 1, 'active': false } + * ]; + * + * // using the "_.matches" callback shorthand + * _.map(_.partition(users, { 'age': 1 }), function(array) { return _.pluck(array, 'user'); }); + * // => [['pebbles'], ['barney', 'fred']] + * + * // using the "_.property" callback shorthand + * _.map(_.partition(users, 'active'), function(array) { return _.pluck(array, 'user'); }); + * // => [['fred'], ['barney', 'pebbles']] + */ + var partition = createAggregator(function(result, value, key) { + result[key ? 0 : 1].push(value); + }, function() { return [[], []]; }); + + /** + * Gets the value of `key` from all elements in `collection`. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {string} key The key of the property to pluck. + * @returns {Array} Returns the property values. + * @example + * + * var users = [ + * { 'user': 'barney', 'age': 36 }, + * { 'user': 'fred', 'age': 40 } + * ]; + * + * _.pluck(users, 'user'); + * // => ['barney', 'fred'] + * + * var userIndex = _.indexBy(users, 'user'); + * _.pluck(userIndex, 'age'); + * // => [36, 40] (iteration order is not guaranteed) + */ + function pluck(collection, key) { + return map(collection, property(key)); + } + + /** + * Reduces `collection` to a value which is the accumulated result of running + * each element in `collection` through `iteratee`, where each successive + * invocation is supplied the return value of the previous. If `accumulator` + * is not provided the first element of `collection` is used as the initial + * value. The `iteratee` is bound to `thisArg`and invoked with four arguments; + * (accumulator, value, index|key, collection). + * + * @static + * @memberOf _ + * @alias foldl, inject + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @param {*} [accumulator] The initial value. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {*} Returns the accumulated value. + * @example + * + * var sum = _.reduce([1, 2, 3], function(sum, n) { return sum + n; }); + * // => 6 + * + * var mapped = _.reduce({ 'a': 1, 'b': 2, 'c': 3 }, function(result, n, key) { + * result[key] = n * 3; + * return result; + * }, {}); + * // => { 'a': 3, 'b': 6, 'c': 9 } (iteration order is not guaranteed) + */ + function reduce(collection, iteratee, accumulator, thisArg) { + var func = isArray(collection) ? arrayReduce : baseReduce; + return func(collection, getCallback(iteratee, thisArg, 4), accumulator, arguments.length < 3, baseEach); + } + + /** + * This method is like `_.reduce` except that it iterates over elements of + * `collection` from right to left. + * + * @static + * @memberOf _ + * @alias foldr + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @param {*} [accumulator] The initial value. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {*} Returns the accumulated value. + * @example + * + * var array = [[0, 1], [2, 3], [4, 5]]; + * _.reduceRight(array, function(flattened, other) { return flattened.concat(other); }, []); + * // => [4, 5, 2, 3, 0, 1] + */ + function reduceRight(collection, iteratee, accumulator, thisArg) { + var func = isArray(collection) ? arrayReduceRight : baseReduce; + return func(collection, getCallback(iteratee, thisArg, 4), accumulator, arguments.length < 3, baseEachRight); + } + + /** + * The opposite of `_.filter`; this method returns the elements of `collection` + * that `predicate` does **not** return truthy for. + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. If a property name or object is provided it is used to + * create a "_.property" or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {Array} Returns the new filtered array. + * @example + * + * var odds = _.reject([1, 2, 3, 4], function(n) { return n % 2 == 0; }); + * // => [1, 3] + * + * var users = [ + * { 'user': 'barney', 'age': 36, 'active': false }, + * { 'user': 'fred', 'age': 40, 'active': true } + * ]; + * + * // using the "_.property" callback shorthand + * _.pluck(_.reject(users, 'active'), 'user'); + * // => ['barney'] + * + * // using the "_.matches" callback shorthand + * _.pluck(_.reject(users, { 'age': 36 }), 'user'); + * // => ['fred'] + */ + function reject(collection, predicate, thisArg) { + var func = isArray(collection) ? arrayFilter : baseFilter; + predicate = getCallback(predicate, thisArg, 3); + return func(collection, function(value, index, collection) { + return !predicate(value, index, collection); + }); + } + + /** + * Gets a random element or `n` random elements from a collection. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to sample. + * @param {number} [n] The number of elements to sample. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {*} Returns the random sample(s). + * @example + * + * _.sample([1, 2, 3, 4]); + * // => 2 + * + * _.sample([1, 2, 3, 4], 2); + * // => [3, 1] + */ + function sample(collection, n, guard) { + if (guard ? isIterateeCall(collection, n, guard) : n == null) { + collection = toIterable(collection); + var length = collection.length; + return length > 0 ? collection[baseRandom(0, length - 1)] : undefined; + } + var result = shuffle(collection); + result.length = nativeMin(n < 0 ? 0 : (+n || 0), result.length); + return result; + } + + /** + * Creates an array of shuffled values, using a version of the Fisher-Yates + * shuffle. See [Wikipedia](https://en.wikipedia.org/wiki/Fisher-Yates_shuffle) + * for more details. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to shuffle. + * @returns {Array} Returns the new shuffled array. + * @example + * + * _.shuffle([1, 2, 3, 4]); + * // => [4, 1, 3, 2] + */ + function shuffle(collection) { + collection = toIterable(collection); + + var index = -1, + length = collection.length, + result = Array(length); + + while (++index < length) { + var rand = baseRandom(0, index); + if (index != rand) { + result[index] = result[rand]; + } + result[rand] = collection[index]; + } + return result; + } + + /** + * Gets the size of `collection` by returning `collection.length` for + * array-like values or the number of own enumerable properties for objects. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to inspect. + * @returns {number} Returns the size of `collection`. + * @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 isLength(length) ? length : keys(collection).length; + } + + /** + * Checks if `predicate` returns truthy for **any** element of `collection`. + * The function returns as soon as it finds a passing value and does not iterate + * over the entire collection. The predicate is bound to `thisArg` and invoked + * with three arguments; (value, index|key, collection). + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @alias any + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. If a property name or object is provided it is used to + * create a "_.property" or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {boolean} Returns `true` if any element passes the predicate check, + * else `false`. + * @example + * + * _.some([null, 0, 'yes', false], Boolean); + * // => true + * + * var users = [ + * { 'user': 'barney', 'age': 36, 'active': false }, + * { 'user': 'fred', 'age': 40, 'active': true } + * ]; + * + * // using the "_.property" callback shorthand + * _.some(users, 'active'); + * // => true + * + * // using the "_.matches" callback shorthand + * _.some(users, { 'age': 1 }); + * // => false + */ + function some(collection, predicate, thisArg) { + var func = isArray(collection) ? arraySome : baseSome; + if (typeof predicate != 'function' || typeof thisArg != 'undefined') { + predicate = getCallback(predicate, thisArg, 3); + } + return func(collection, predicate); + } + + /** + * Creates an array of elements, sorted in ascending order by the results of + * running each element in a collection through `iteratee`. This method performs + * a stable sort, that is, it preserves the original sort order of equal elements. + * The `iteratee` is bound to `thisArg` and invoked with three arguments; + * (value, index|key, collection). + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Array|Function|Object|string} [iteratee=_.identity] The function + * invoked per iteration. If a property name or an object is provided it is + * used to create a "_.property" or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Array} Returns the new sorted array. + * @example + * + * _.sortBy([1, 2, 3], function(n) { return Math.sin(n); }); + * // => [3, 1, 2] + * + * _.sortBy([1, 2, 3], function(n) { return this.sin(n); }, Math); + * // => [3, 1, 2] + * + * var users = [ + * { 'user': 'fred' }, + * { 'user': 'pebbles' }, + * { 'user': 'barney' } + * ]; + * + * // using the "_.property" callback shorthand + * _.pluck(_.sortBy(users, 'user'), 'user'); + * // => ['barney', 'fred', 'pebbles'] + */ + function sortBy(collection, iteratee, thisArg) { + var index = -1, + length = collection ? collection.length : 0, + result = isLength(length) ? Array(length) : []; + + if (thisArg && isIterateeCall(collection, iteratee, thisArg)) { + iteratee = null; + } + iteratee = getCallback(iteratee, thisArg, 3); + baseEach(collection, function(value, key, collection) { + result[++index] = { 'criteria': iteratee(value, key, collection), 'index': index, 'value': value }; + }); + return baseSortBy(result, compareAscending); + } + + /** + * This method is like `_.sortBy` except that it sorts by property names + * instead of an iteratee function. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {...(string|string[])} props The property names to sort by, + * specified as individual property names or arrays of property names. + * @returns {Array} Returns the new sorted array. + * @example + * + * var users = [ + * { 'user': 'barney', 'age': 36 }, + * { 'user': 'fred', 'age': 40 }, + * { 'user': 'barney', 'age': 26 }, + * { 'user': 'fred', 'age': 30 } + * ]; + * + * _.map(_.sortByAll(users, ['user', 'age']), _.values); + * // => [['barney', 26], ['barney', 36], ['fred', 30], ['fred', 40]] + */ + function sortByAll(collection) { + var args = arguments; + if (args.length > 3 && isIterateeCall(args[1], args[2], args[3])) { + args = [collection, args[1]]; + } + var index = -1, + length = collection ? collection.length : 0, + props = baseFlatten(args, false, false, 1), + result = isLength(length) ? Array(length) : []; + + baseEach(collection, function(value, key, collection) { + var length = props.length, + criteria = Array(length); + + while (length--) { + criteria[length] = value == null ? undefined : value[props[length]]; + } + result[++index] = { 'criteria': criteria, 'index': index, 'value': value }; + }); + return baseSortBy(result, compareMultipleAscending); + } + + /** + * Performs a deep comparison between each element in `collection` and the + * source object, returning an array of all elements that have equivalent + * property values. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to search. + * @param {Object} source The object of property values to match. + * @returns {Array} Returns the new filtered array. + * @example + * + * var users = [ + * { 'user': 'barney', 'age': 36, 'status': 'busy', 'pets': ['hoppy'] }, + * { 'user': 'fred', 'age': 40, 'status': 'busy', 'pets': ['baby puss', 'dino'] } + * ]; + * + * _.pluck(_.where(users, { 'age': 36 }), 'user'); + * // => ['barney'] + * + * _.pluck(_.where(users, { 'pets': ['dino'] }), 'user'); + * // => ['fred'] + * + * _.pluck(_.where(users, { 'status': 'busy' }), 'user'); + * // => ['barney', 'fred'] + */ + function where(collection, source) { + return filter(collection, matches(source)); + } + + /*------------------------------------------------------------------------*/ + + /** + * Gets the number of milliseconds that have elapsed since the Unix epoch + * (1 January 1970 00:00:00 UTC). + * + * @static + * @memberOf _ + * @category Date + * @example + * + * _.defer(function(stamp) { console.log(_.now() - stamp); }, _.now()); + * // => logs the number of milliseconds it took for the deferred function to be invoked + */ + var now = nativeNow || function() { + return new Date().getTime(); + }; + + /*------------------------------------------------------------------------*/ + + /** + * The opposite of `_.before`; this method creates a function that invokes + * `func` once it is called `n` or more times. + * + * @static + * @memberOf _ + * @category Function + * @param {number} n The number of calls before `func` is invoked. + * @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 the two async saves have completed + */ + function after(n, func) { + if (!isFunction(func)) { + if (isFunction(n)) { + var temp = n; + n = func; + func = temp; + } else { + throw new TypeError(FUNC_ERROR_TEXT); + } + } + n = nativeIsFinite(n = +n) ? n : 0; + return function() { + if (--n < 1) { + return func.apply(this, arguments); + } + }; + } + + /** + * Creates a function that accepts up to `n` arguments ignoring any + * additional arguments. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to cap arguments for. + * @param {number} [n=func.length] The arity cap. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {Function} Returns the new function. + * @example + * + * _.map(['6', '8', '10'], _.ary(parseInt, 1)); + * // => [6, 8, 10] + */ + function ary(func, n, guard) { + if (guard && isIterateeCall(func, n, guard)) { + n = null; + } + n = (func && n == null) ? func.length : nativeMax(+n || 0, 0); + return createWrapper(func, ARY_FLAG, null, null, null, null, n); + } + + /** + * Creates a function that invokes `func`, with the `this` binding and arguments + * of the created function, while it is called less than `n` times. Subsequent + * calls to the created function return the result of the last `func` invocation. + * + * @static + * @memberOf _ + * @category Function + * @param {number} n The number of calls at which `func` is no longer invoked. + * @param {Function} func The function to restrict. + * @returns {Function} Returns the new restricted function. + * @example + * + * jQuery('#add').on('click', _.before(5, addContactToList)); + * // => allows adding up to 4 contacts to the list + */ + function before(n, func) { + var result; + if (!isFunction(func)) { + if (isFunction(n)) { + var temp = n; + n = func; + func = temp; + } else { + throw new TypeError(FUNC_ERROR_TEXT); + } + } + return function() { + if (--n > 0) { + result = func.apply(this, arguments); + } else { + func = null; + } + return result; + }; + } + + /** + * Creates a function that invokes `func` with the `this` binding of `thisArg` + * and prepends any additional `_.bind` arguments to those provided to the + * bound function. + * + * The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, + * may be used as a placeholder for partially applied arguments. + * + * **Note:** Unlike native `Function#bind` this method does not set the `length` + * property of bound functions. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to bind. + * @param {*} thisArg The `this` binding of `func`. + * @param {...*} [args] The arguments to be partially applied. + * @returns {Function} Returns the new bound function. + * @example + * + * var greet = function(greeting, punctuation) { + * return greeting + ' ' + this.user + punctuation; + * }; + * + * var object = { 'user': 'fred' }; + * + * var bound = _.bind(greet, object, 'hi'); + * bound('!'); + * // => 'hi fred!' + * + * // using placeholders + * var bound = _.bind(greet, object, _, '!'); + * bound('hi'); + * // => 'hi fred!' + */ + function bind(func, thisArg) { + var bitmask = BIND_FLAG; + if (arguments.length > 2) { + var partials = baseSlice(arguments, 2), + holders = replaceHolders(partials, bind.placeholder); + + bitmask |= PARTIAL_FLAG; + } + return createWrapper(func, bitmask, thisArg, partials, holders); + } + + /** + * 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 enumerable function + * properties, own and inherited, of `object` are bound. + * + * **Note:** This method does not set the `length` property of bound functions. + * + * @static + * @memberOf _ + * @category Function + * @param {Object} object The object to bind and assign the bound methods to. + * @param {...(string|string[])} [methodNames] 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 element is clicked + */ + function bindAll(object) { + return baseBindAll(object, + arguments.length > 1 + ? baseFlatten(arguments, false, false, 1) + : functions(object) + ); + } + + /** + * Creates a function that 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 may be redefined or don't yet exist. + * See [Peter Michaux's article](http://michaux.ca/articles/lazy-function-definition-pattern) + * for more details. + * + * The `_.bindKey.placeholder` value, which defaults to `_` in monolithic + * builds, may be used as a placeholder for partially applied arguments. + * + * @static + * @memberOf _ + * @category Function + * @param {Object} object The object the method belongs to. + * @param {string} key The key of the method. + * @param {...*} [args] The arguments to be partially applied. + * @returns {Function} Returns the new bound function. + * @example + * + * var object = { + * 'user': 'fred', + * 'greet': function(greeting, punctuation) { + * return greeting + ' ' + this.user + punctuation; + * } + * }; + * + * var bound = _.bindKey(object, 'greet', 'hi'); + * bound('!'); + * // => 'hi fred!' + * + * object.greet = function(greeting, punctuation) { + * return greeting + 'ya ' + this.user + punctuation; + * }; + * + * bound('!'); + * // => 'hiya fred!' + * + * // using placeholders + * var bound = _.bindKey(object, 'greet', _, '!'); + * bound('hi'); + * // => 'hiya fred!' + */ + function bindKey(object, key) { + var bitmask = BIND_FLAG | BIND_KEY_FLAG; + if (arguments.length > 2) { + var partials = baseSlice(arguments, 2), + holders = replaceHolders(partials, bindKey.placeholder); + + bitmask |= PARTIAL_FLAG; + } + return createWrapper(key, bitmask, object, partials, holders); + } + + /** + * Creates a function that accepts one or more arguments of `func` that when + * called either invokes `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` may be specified + * if `func.length` is not sufficient. + * + * The `_.curry.placeholder` value, which defaults to `_` in monolithic builds, + * may be used as a placeholder for provided arguments. + * + * **Note:** This method does not set the `length` property of curried functions. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to curry. + * @param {number} [arity=func.length] The arity of `func`. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {Function} Returns the new curried function. + * @example + * + * var abc = function(a, b, c) { + * return [a, b, c]; + * }; + * + * var curried = _.curry(abc); + * + * curried(1)(2)(3); + * // => [1, 2, 3] + * + * curried(1, 2)(3); + * // => [1, 2, 3] + * + * curried(1, 2, 3); + * // => [1, 2, 3] + * + * // using placeholders + * curried(1)(_, 3)(2); + * // => [1, 2, 3] + */ + function curry(func, arity, guard) { + if (guard && isIterateeCall(func, arity, guard)) { + arity = null; + } + var result = createWrapper(func, CURRY_FLAG, null, null, null, null, null, arity); + result.placeholder = curry.placeholder; + return result; + } + + /** + * This method is like `_.curry` except that arguments are applied to `func` + * in the manner of `_.partialRight` instead of `_.partial`. + * + * The `_.curryRight.placeholder` value, which defaults to `_` in monolithic + * builds, may be used as a placeholder for provided arguments. + * + * **Note:** This method does not set the `length` property of curried functions. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to curry. + * @param {number} [arity=func.length] The arity of `func`. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {Function} Returns the new curried function. + * @example + * + * var abc = function(a, b, c) { + * return [a, b, c]; + * }; + * + * var curried = _.curryRight(abc); + * + * curried(3)(2)(1); + * // => [1, 2, 3] + * + * curried(2, 3)(1); + * // => [1, 2, 3] + * + * curried(1, 2, 3); + * // => [1, 2, 3] + * + * // using placeholders + * curried(3)(1, _)(2); + * // => [1, 2, 3] + */ + function curryRight(func, arity, guard) { + if (guard && isIterateeCall(func, arity, guard)) { + arity = null; + } + var result = createWrapper(func, CURRY_RIGHT_FLAG, null, null, null, null, null, arity); + result.placeholder = curryRight.placeholder; + return result; + } + + /** + * Creates a function that delays invoking `func` until after `wait` milliseconds + * have elapsed since the last time it was invoked. The created function comes + * with a `cancel` method to cancel delayed invocations. 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 return the result of the last `func` invocation. + * + * **Note:** If `leading` and `trailing` options are `true`, `func` is invoked + * on the trailing edge of the timeout only if the the debounced function is + * invoked more than once during the `wait` timeout. + * + * See [David Corbacho's article](http://drupalmotion.com/article/debounce-and-throttle-visual-explanation) + * for details over the differences between `_.debounce` and `_.throttle`. + * + * @static + * @memberOf _ + * @category Function + * @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 invoking on the leading + * edge of the timeout. + * @param {number} [options.maxWait] The maximum time `func` is allowed to be + * delayed before it is invoked. + * @param {boolean} [options.trailing=true] Specify invoking 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 + * jQuery(window).on('resize', _.debounce(calculateLayout, 150)); + * + * // invoke `sendMail` when the click event is fired, debouncing subsequent calls + * jQuery('#postbox').on('click', _.debounce(sendMail, 300, { + * 'leading': true, + * 'trailing': false + * })); + * + * // ensure `batchLog` is invoked once after 1 second of debounced calls + * var source = new EventSource('/stream'); + * jQuery(source).on('message', _.debounce(batchLog, 250, { + * 'maxWait': 1000 + * })); + * + * // cancel a debounced call + * var todoChanges = _.debounce(batchLog, 1000); + * Object.observe(models.todo, todoChanges); + * + * Object.observe(models, function(changes) { + * if (_.find(changes, { 'user': 'todo', 'type': 'delete'})) { + * todoChanges.cancel(); + * } + * }, ['delete']); + * + * // ...at some point `models.todo` is changed + * models.todo.completed = true; + * + * // ...before 1 second has passed `models.todo` is deleted + * // which cancels the debounced `todoChanges` call + * delete models.todo; + */ + 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(FUNC_ERROR_TEXT); + } + wait = wait < 0 ? 0 : wait; + if (options === true) { + var leading = true; + trailing = false; + } else if (isObject(options)) { + leading = options.leading; + maxWait = 'maxWait' in options && nativeMax(+options.maxWait || 0, wait); + trailing = 'trailing' in options ? options.trailing : trailing; + } + + function cancel() { + if (timeoutId) { + clearTimeout(timeoutId); + } + if (maxTimeoutId) { + clearTimeout(maxTimeoutId); + } + maxTimeoutId = timeoutId = trailingCall = undefined; + } + + function delayed() { + var remaining = wait - (now() - stamp); + if (remaining <= 0 || remaining > wait) { + if (maxTimeoutId) { + clearTimeout(maxTimeoutId); + } + var isCalled = trailingCall; + maxTimeoutId = timeoutId = trailingCall = undefined; + if (isCalled) { + lastCalled = now(); + result = func.apply(thisArg, args); + if (!timeoutId && !maxTimeoutId) { + args = thisArg = null; + } + } + } else { + timeoutId = setTimeout(delayed, remaining); + } + } + + function maxDelayed() { + 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; + } + } + } + + function debounced() { + args = arguments; + stamp = now(); + thisArg = this; + trailingCall = trailing && (timeoutId || !leading); + + if (maxWait === false) { + var leadingCall = leading && !timeoutId; + } else { + if (!maxTimeoutId && !leading) { + lastCalled = stamp; + } + var remaining = maxWait - (stamp - lastCalled), + isCalled = remaining <= 0 || remaining > maxWait; + + if (isCalled) { + if (maxTimeoutId) { + maxTimeoutId = clearTimeout(maxTimeoutId); + } + lastCalled = stamp; + result = func.apply(thisArg, args); + } + else if (!maxTimeoutId) { + maxTimeoutId = setTimeout(maxDelayed, remaining); + } + } + if (isCalled && timeoutId) { + timeoutId = clearTimeout(timeoutId); + } + else if (!timeoutId && wait !== maxWait) { + timeoutId = setTimeout(delayed, wait); + } + if (leadingCall) { + isCalled = true; + result = func.apply(thisArg, args); + } + if (isCalled && !timeoutId && !maxTimeoutId) { + args = thisArg = null; + } + return result; + } + debounced.cancel = cancel; + return debounced; + } + + /** + * Defers invoking the `func` until the current call stack has cleared. Any + * additional arguments are provided to `func` when it is invoked. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to defer. + * @param {...*} [args] The 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) { + return baseDelay(func, 1, arguments, 1); + } + + /** + * Invokes `func` after `wait` milliseconds. Any additional arguments are + * provided to `func` when it is invoked. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to delay. + * @param {number} wait The number of milliseconds to delay invocation. + * @param {...*} [args] The 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) { + return baseDelay(func, wait, arguments, 2); + } + + /** + * Creates a function that returns the result of invoking the provided + * functions with the `this` binding of the created function, where each + * successive invocation is supplied the return value of the previous. + * + * @static + * @memberOf _ + * @category Function + * @param {...Function} [funcs] Functions to invoke. + * @returns {Function} Returns the new function. + * @example + * + * function add(x, y) { + * return x + y; + * } + * + * function square(n) { + * return n * n; + * } + * + * var addSquare = _.flow(add, square); + * addSquare(1, 2); + * // => 9 + */ + function flow() { + var funcs = arguments, + length = funcs.length; + + if (!length) { + return function() {}; + } + if (!arrayEvery(funcs, isFunction)) { + throw new TypeError(FUNC_ERROR_TEXT); + } + return function() { + var index = 0, + result = funcs[index].apply(this, arguments); + + while (++index < length) { + result = funcs[index].call(this, result); + } + return result; + }; + } + + /** + * This method is like `_.flow` except that it creates a function that + * invokes the provided functions from right to left. + * + * @static + * @memberOf _ + * @alias backflow, compose + * @category Function + * @param {...Function} [funcs] Functions to invoke. + * @returns {Function} Returns the new function. + * @example + * + * function add(x, y) { + * return x + y; + * } + * + * function square(n) { + * return n * n; + * } + * + * var addSquare = _.flowRight(square, add); + * addSquare(1, 2); + * // => 9 + */ + function flowRight() { + var funcs = arguments, + fromIndex = funcs.length - 1; + + if (fromIndex < 0) { + return function() {}; + } + if (!arrayEvery(funcs, isFunction)) { + throw new TypeError(FUNC_ERROR_TEXT); + } + return function() { + var index = fromIndex, + result = funcs[index].apply(this, arguments); + + while (index--) { + result = funcs[index].call(this, result); + } + return result; + }; + } + + /** + * Creates a function that memoizes the result of `func`. If `resolver` is + * provided it determines 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 coerced to a string and used as the + * cache key. The `func` is invoked with the `this` binding of the memoized + * function. + * + * **Note:** The cache is exposed as the `cache` property on the memoized + * function. Its creation may be customized by replacing the `_.memoize.Cache` + * constructor with one whose instances implement the ES `Map` method interface + * of `get`, `has`, and `set`. See the + * [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-properties-of-the-map-prototype-object) + * for more details. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to have its output memoized. + * @param {Function} [resolver] The function to resolve the cache key. + * @returns {Function} Returns the new memoizing function. + * @example + * + * var upperCase = _.memoize(function(string) { + * return string.toUpperCase(); + * }); + * + * upperCase('fred'); + * // => 'FRED' + * + * // modifying the result cache + * upperCase.cache.set('fred', 'BARNEY'); + * upperCase('fred'); + * // => 'BARNEY' + * + * // replacing `_.memoize.Cache` + * var object = { 'user': 'fred' }; + * var other = { 'user': 'barney' }; + * var identity = _.memoize(_.identity); + * + * identity(object); + * // => { 'user': 'fred' } + * identity(other); + * // => { 'user': 'fred' } + * + * _.memoize.Cache = WeakMap; + * var identity = _.memoize(_.identity); + * + * identity(object); + * // => { 'user': 'fred' } + * identity(other); + * // => { 'user': 'barney' } + */ + function memoize(func, resolver) { + if (!isFunction(func) || (resolver && !isFunction(resolver))) { + throw new TypeError(FUNC_ERROR_TEXT); + } + var memoized = function() { + var cache = memoized.cache, + key = resolver ? resolver.apply(this, arguments) : arguments[0]; + + if (cache.has(key)) { + return cache.get(key); + } + var result = func.apply(this, arguments); + cache.set(key, result); + return result; + }; + memoized.cache = new memoize.Cache; + return memoized; + } + + /** + * Creates a function that negates the result of the predicate `func`. The + * `func` predicate is invoked with the `this` binding and arguments of the + * created function. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} predicate The predicate to negate. + * @returns {Function} Returns the new function. + * @example + * + * function isEven(n) { + * return n % 2 == 0; + * } + * + * _.filter([1, 2, 3, 4, 5, 6], _.negate(isEven)); + * // => [1, 3, 5] + */ + function negate(predicate) { + if (!isFunction(predicate)) { + throw new TypeError(FUNC_ERROR_TEXT); + } + return function() { + return !predicate.apply(this, arguments); + }; + } + + /** + * Creates a function that is restricted to invoking `func` once. Repeat calls + * to the function return the value of the first call. The `func` is invoked + * with the `this` binding of the created function. + * + * @static + * @memberOf _ + * @type Function + * @category Function + * @param {Function} func The function to restrict. + * @returns {Function} Returns the new restricted function. + * @example + * + * var initialize = _.once(createApplication); + * initialize(); + * initialize(); + * // `initialize` invokes `createApplication` once + */ + function once(func) { + return before(func, 2); + } + + /** + * Creates a function that invokes `func` with `partial` arguments prepended + * to those provided to the new function. This method is like `_.bind` except + * it does **not** alter the `this` binding. + * + * The `_.partial.placeholder` value, which defaults to `_` in monolithic + * builds, may be used as a placeholder for partially applied arguments. + * + * **Note:** This method does not set the `length` property of partially + * applied functions. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to partially apply arguments to. + * @param {...*} [args] The arguments to be partially applied. + * @returns {Function} Returns the new partially applied function. + * @example + * + * var greet = function(greeting, name) { + * return greeting + ' ' + name; + * }; + * + * var sayHelloTo = _.partial(greet, 'hello'); + * sayHelloTo('fred'); + * // => 'hello fred' + * + * // using placeholders + * var greetFred = _.partial(greet, _, 'fred'); + * greetFred('hi'); + * // => 'hi fred' + */ + function partial(func) { + var partials = baseSlice(arguments, 1), + holders = replaceHolders(partials, partial.placeholder); + + return createWrapper(func, PARTIAL_FLAG, null, partials, holders); + } + + /** + * This method is like `_.partial` except that partially applied arguments + * are appended to those provided to the new function. + * + * The `_.partialRight.placeholder` value, which defaults to `_` in monolithic + * builds, may be used as a placeholder for partially applied arguments. + * + * **Note:** This method does not set the `length` property of partially + * applied functions. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to partially apply arguments to. + * @param {...*} [args] The arguments to be partially applied. + * @returns {Function} Returns the new partially applied function. + * @example + * + * var greet = function(greeting, name) { + * return greeting + ' ' + name; + * }; + * + * var greetFred = _.partialRight(greet, 'fred'); + * greetFred('hi'); + * // => 'hi fred' + * + * // using placeholders + * var sayHelloTo = _.partialRight(greet, 'hello', _); + * sayHelloTo('fred'); + * // => 'hello fred' + */ + function partialRight(func) { + var partials = baseSlice(arguments, 1), + holders = replaceHolders(partials, partialRight.placeholder); + + return createWrapper(func, PARTIAL_RIGHT_FLAG, null, partials, holders); + } + + /** + * Creates a function that invokes `func` with arguments arranged according + * to the specified indexes where the argument value at the first index is + * provided as the first argument, the argument value at the second index is + * provided as the second argument, and so on. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to rearrange arguments for. + * @param {...(number|number[])} indexes The arranged argument indexes, + * specified as individual indexes or arrays of indexes. + * @returns {Function} Returns the new function. + * @example + * + * var rearged = _.rearg(function(a, b, c) { + * return [a, b, c]; + * }, 2, 0, 1); + * + * rearged('b', 'c', 'a') + * // => ['a', 'b', 'c'] + * + * var map = _.rearg(_.map, [1, 0]); + * map(function(n) { return n * 3; }, [1, 2, 3]); + * // => [3, 6, 9] + */ + function rearg(func) { + var indexes = baseFlatten(arguments, false, false, 1); + return createWrapper(func, REARG_FLAG, null, null, null, indexes); + } + + /** + * Creates a function that only invokes `func` at most once per every `wait` + * milliseconds. The created function comes with a `cancel` method to cancel + * delayed invocations. 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 return the result of the last + * `func` call. + * + * **Note:** If `leading` and `trailing` options are `true`, `func` is invoked + * on the trailing edge of the timeout only if the the throttled function is + * invoked more than once during the `wait` timeout. + * + * See [David Corbacho's article](http://drupalmotion.com/article/debounce-and-throttle-visual-explanation) + * for details over the differences between `_.throttle` and `_.debounce`. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to throttle. + * @param {number} wait The number of milliseconds to throttle invocations to. + * @param {Object} [options] The options object. + * @param {boolean} [options.leading=true] Specify invoking on the leading + * edge of the timeout. + * @param {boolean} [options.trailing=true] Specify invoking on the trailing + * edge of the timeout. + * @returns {Function} Returns the new throttled function. + * @example + * + * // avoid excessively updating the position while scrolling + * jQuery(window).on('scroll', _.throttle(updatePosition, 100)); + * + * // invoke `renewToken` when the click event is fired, but not more than once every 5 minutes + * var throttled = _.throttle(renewToken, 300000, { 'trailing': false }) + * jQuery('.interactive').on('click', throttled); + * + * // cancel a trailing throttled call + * jQuery(window).on('popstate', throttled.cancel); + */ + function throttle(func, wait, options) { + var leading = true, + trailing = true; + + if (!isFunction(func)) { + throw new TypeError(FUNC_ERROR_TEXT); + } + 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. Any additional arguments provided to the function are + * appended to those provided to the wrapper function. The wrapper is invoked + * with the `this` binding of the created function. + * + * @static + * @memberOf _ + * @category Function + * @param {*} value The value to wrap. + * @param {Function} wrapper The wrapper function. + * @returns {Function} Returns the new function. + * @example + * + * var p = _.wrap(_.escape, function(func, text) { + * return '

' + func(text) + '

'; + * }); + * + * p('fred, barney, & pebbles'); + * // => '

fred, barney, & pebbles

' + */ + function wrap(value, wrapper) { + wrapper = wrapper == null ? identity : wrapper; + return createWrapper(wrapper, PARTIAL_FLAG, null, [value], []); + } + + /*------------------------------------------------------------------------*/ + + /** + * Creates a clone of `value`. If `isDeep` is `true` nested objects are cloned, + * otherwise they are assigned by reference. If `customizer` is provided it is + * invoked to produce the cloned values. If `customizer` returns `undefined` + * cloning is handled by the method instead. The `customizer` is bound to + * `thisArg` and invoked with two argument; (value [, index|key, object]). + * + * **Note:** This method is loosely based on the structured clone algorithm. + * The enumerable properties of `arguments` objects and objects created by + * constructors other than `Object` are cloned to plain `Object` objects. An + * empty object is returned for uncloneable values such as functions, DOM nodes, + * Maps, Sets, and WeakMaps. See the [HTML5 specification](http://www.w3.org/TR/html5/infrastructure.html#internal-structured-cloning-algorithm) + * for more details. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to clone. + * @param {boolean} [isDeep] Specify a deep clone. + * @param {Function} [customizer] The function to customize cloning values. + * @param {*} [thisArg] The `this` binding of `customizer`. + * @returns {*} Returns the cloned value. + * @example + * + * var users = [ + * { 'user': 'barney' }, + * { 'user': 'fred' } + * ]; + * + * var shallow = _.clone(users); + * shallow[0] === users[0]; + * // => true + * + * var deep = _.clone(users, true); + * deep[0] === users[0]; + * // => false + * + * // using a customizer callback + * var body = _.clone(document.body, function(value) { + * return _.isElement(value) ? value.cloneNode(false) : undefined; + * }); + * + * body === document.body + * // => false + * body.nodeName + * // => BODY + * body.childNodes.length; + * // => 0 + */ + function clone(value, isDeep, customizer, thisArg) { + // Juggle arguments. + if (typeof isDeep != 'boolean' && isDeep != null) { + thisArg = customizer; + customizer = isIterateeCall(value, isDeep, thisArg) ? null : isDeep; + isDeep = false; + } + customizer = typeof customizer == 'function' && bindCallback(customizer, thisArg, 1); + return baseClone(value, isDeep, customizer); + } + + /** + * Creates a deep clone of `value`. If `customizer` is provided it is invoked + * to produce the cloned values. If `customizer` returns `undefined` cloning + * is handled by the method instead. The `customizer` is bound to `thisArg` + * and invoked with two argument; (value [, index|key, object]). + * + * **Note:** This method is loosely based on the structured clone algorithm. + * The enumerable properties of `arguments` objects and objects created by + * constructors other than `Object` are cloned to plain `Object` objects. An + * empty object is returned for uncloneable values such as functions, DOM nodes, + * Maps, Sets, and WeakMaps. See the [HTML5 specification](http://www.w3.org/TR/html5/infrastructure.html#internal-structured-cloning-algorithm) + * for more details. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to deep clone. + * @param {Function} [customizer] The function to customize cloning values. + * @param {*} [thisArg] The `this` binding of `customizer`. + * @returns {*} Returns the deep cloned value. + * @example + * + * var users = [ + * { 'user': 'barney' }, + * { 'user': 'fred' } + * ]; + * + * var deep = _.cloneDeep(users); + * deep[0] === users[0]; + * // => false + * + * // using a customizer callback + * var el = _.cloneDeep(document.body, function(value) { + * return _.isElement(value) ? value.cloneNode(true) : undefined; + * }); + * + * body === document.body + * // => false + * body.nodeName + * // => BODY + * body.childNodes.length; + * // => 20 + */ + function cloneDeep(value, customizer, thisArg) { + customizer = typeof customizer == 'function' && bindCallback(customizer, thisArg, 1); + return baseClone(value, true, customizer); + } + + /** + * Checks if `value` is classified as an `arguments` object. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * (function() { return _.isArguments(arguments); })(); + * // => true + * + * _.isArguments([1, 2, 3]); + * // => false + */ + function isArguments(value) { + var length = isObjectLike(value) ? value.length : undefined; + return (isLength(length) && objToString.call(value) == argsTag) || false; + } + + /** + * Checks if `value` is classified as an `Array` object. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isArray([1, 2, 3]); + * // => true + * + * (function() { return _.isArray(arguments); })(); + * // => false + */ + var isArray = nativeIsArray || function(value) { + return (isObjectLike(value) && isLength(value.length) && objToString.call(value) == arrayTag) || false; + }; + + /** + * Checks if `value` is classified as a boolean primitive or object. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isBoolean(false); + * // => true + * * _.isBoolean(null); * // => false */ function isBoolean(value) { - return value === true || value === false || toString.call(value) == boolClass; + return (value === true || value === false || isObjectLike(value) && objToString.call(value) == boolTag) || false; } /** - * Checks if `value` is a date. + * Checks if `value` is classified as a `Date` object. * * @static * @memberOf _ - * @category Objects - * @param {Mixed} value The value to check. - * @returns {Boolean} Returns `true`, if the `value` is a date, else `false`. + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. * @example * * _.isDate(new Date); * // => true + * + * _.isDate('Mon April 23 2012'); + * // => false */ function isDate(value) { - return value ? (typeof value == 'object' && toString.call(value) == dateClass) : false; + return (isObjectLike(value) && objToString.call(value) == dateTag) || false; } /** @@ -1687,320 +7593,212 @@ * * @static * @memberOf _ - * @category Objects - * @param {Mixed} value The value to check. - * @returns {Boolean} Returns `true`, if the `value` is a DOM element, else `false`. + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is a DOM element, else `false`. * @example * * _.isElement(document.body); * // => true + * + * _.isElement(''); + * // => false */ function isElement(value) { - return value ? value.nodeType === 1 : false; + return (value && value.nodeType === 1 && isObjectLike(value) && + objToString.call(value).indexOf('Element') > -1) || false; + } + // Fallback for environments without DOM support. + if (!support.dom) { + isElement = function(value) { + return (value && value.nodeType === 1 && isObjectLike(value) && !isPlainObject(value)) || 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". + * Checks if a value is empty. A value is considered empty unless it is an + * `arguments` object, array, string, or jQuery-like collection with a length + * greater than `0` or an object with own enumerable properties. * * @static * @memberOf _ - * @category Objects - * @param {Array|Object|String} value The value to inspect. - * @returns {Boolean} Returns `true`, if the `value` is empty, else `false`. + * @category Lang + * @param {Array|Object|string} value The value to inspect. + * @returns {boolean} Returns `true` if `value` is empty, else `false`. * @example * + * _.isEmpty(null); + * // => true + * + * _.isEmpty(true); + * // => true + * + * _.isEmpty(1); + * // => true + * * _.isEmpty([1, 2, 3]); * // => false * - * _.isEmpty({}); - * // => true - * - * _.isEmpty(''); - * // => true + * _.isEmpty({ 'a': 1 }); + * // => false */ function isEmpty(value) { - var result = true; - if (!value) { - return result; + if (value == null) { + return true; } - var className = toString.call(value), - length = value.length; - - if ((className == arrayClass || className == stringClass || - (support.argsClass ? className == argsClass : isArguments(value))) || - (className == objectClass && typeof length == 'number' && isFunction(value.splice))) { + var length = value.length; + if (isLength(length) && (isArray(value) || isString(value) || isArguments(value) || + (isObjectLike(value) && isFunction(value.splice)))) { return !length; } - forOwn(value, function() { - return (result = false); - }); - return result; + return !keys(value).length; } /** * Performs a deep comparison between two values to determine if they are - * equivalent to each other. If `callback` is passed, it will be executed to - * compare values. If `callback` returns `undefined`, comparisons will be handled - * by the method instead. The `callback` is bound to `thisArg` and invoked with - * two arguments; (a, b). + * equivalent. If `customizer` is provided it is invoked to compare values. + * If `customizer` returns `undefined` comparisons are handled by the method + * instead. The `customizer` is bound to `thisArg` and invoked with three + * arguments; (value, other [, index|key]). + * + * **Note:** This method supports comparing arrays, booleans, `Date` objects, + * numbers, `Object` objects, regexes, and strings. Functions and DOM nodes + * are **not** supported. Provide a customizer function to extend support + * for comparing other values. * * @static * @memberOf _ - * @category Objects - * @param {Mixed} a The value to compare. - * @param {Mixed} b The other value to compare. - * @param {Function} [callback] The function to customize comparing values. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @param- {Array} [stackA=[]] Tracks traversed `a` objects. - * @param- {Array} [stackB=[]] Tracks traversed `b` objects. - * @returns {Boolean} Returns `true`, if the values are equivalent, else `false`. + * @category Lang + * @param {*} value The value to compare. + * @param {*} other The other value to compare. + * @param {Function} [customizer] The function to customize comparing values. + * @param {*} [thisArg] The `this` binding of `customizer`. + * @returns {boolean} Returns `true` if the values are equivalent, else `false`. * @example * - * var moe = { 'name': 'moe', 'age': 40 }; - * var copy = { 'name': 'moe', 'age': 40 }; + * var object = { 'user': 'fred' }; + * var other = { 'user': 'fred' }; * - * moe == copy; + * object == other; * // => false * - * _.isEqual(moe, copy); + * _.isEqual(object, other); * // => true * - * var words = ['hello', 'goodbye']; - * var otherWords = ['hi', 'goodbye']; + * // using a customizer callback + * var array = ['hello', 'goodbye']; + * var other = ['hi', 'goodbye']; * - * _.isEqual(words, otherWords, function(a, b) { - * var reGreet = /^(?:hello|hi)$/i, - * aGreet = _.isString(a) && reGreet.test(a), - * bGreet = _.isString(b) && reGreet.test(b); - * - * return (aGreet || bGreet) ? (aGreet == bGreet) : undefined; + * _.isEqual(array, other, function(value, other) { + * return _.every([value, other], RegExp.prototype.test, /^h(?:i|ello)$/) || undefined; * }); * // => true */ - function isEqual(a, b, callback, thisArg, stackA, stackB) { - // used to indicate that when comparing objects, `a` has at least the properties of `b` - var whereIndicator = callback === indicatorObject; - if (typeof callback == 'function' && !whereIndicator) { - callback = lodash.createCallback(callback, thisArg, 2); - var result = callback(a, b); - if (typeof result != 'undefined') { - return !!result; - } + function isEqual(value, other, customizer, thisArg) { + customizer = typeof customizer == 'function' && bindCallback(customizer, thisArg, 3); + if (!customizer && isStrictComparable(value) && isStrictComparable(other)) { + return value === other; } - // 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 || (type != 'function' && type != 'object')) && - (!b || (otherType != 'function' && otherType != 'object'))) { - return false; - } - // exit early for `null` and `undefined`, avoiding ES3's Function#call behavior - // http://es5.github.com/#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.com/#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 - if (hasOwnProperty.call(a, '__wrapped__ ') || hasOwnProperty.call(b, '__wrapped__')) { - return isEqual(a.__wrapped__ || a, b.__wrapped__ || b, callback, thisArg, stackA, stackB); - } - // exit for functions and DOM nodes - if (className != objectClass || (!support.nodeClass && (isNode(a) || isNode(b)))) { - return false; - } - // in older versions of Opera, `arguments` objects have `Array` constructors - var ctorA = !support.argsObject && isArguments(a) ? Object : a.constructor, - ctorB = !support.argsObject && isArguments(b) ? Object : 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 - )) { - 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.com/#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) { - length = a.length; - size = b.length; - - // compare lengths to determine if a deep comparison is necessary - result = size == a.length; - if (!result && !whereIndicator) { - return result; - } - // deep compare the contents, ignoring non-numeric properties - while (size--) { - var index = length, - value = b[size]; - - if (whereIndicator) { - while (index--) { - if ((result = isEqual(a[index], value, callback, thisArg, stackA, stackB))) { - break; - } - } - } else if (!(result = isEqual(a[size], value, callback, thisArg, stackA, stackB))) { - break; - } - } - return result; - } - // 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) && isEqual(a[key], value, callback, thisArg, stackA, stackB)); - } - }); - - if (result && !whereIndicator) { - // 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); - } - }); - } - if (initedStack) { - releaseArray(stackA); - releaseArray(stackB); - } - return result; + var result = customizer ? customizer(value, other) : undefined; + return typeof result == 'undefined' ? baseIsEqual(value, other, customizer) : !!result; } /** - * Checks if `value` is, or can be coerced to, a finite number. - * - * Note: This is not the same as native `isFinite`, which will return true for - * booleans and empty strings. See http://es5.github.com/#x15.1.2.5. + * Checks if `value` is an `Error`, `EvalError`, `RangeError`, `ReferenceError`, + * `SyntaxError`, `TypeError`, or `URIError` object. * * @static * @memberOf _ - * @category Objects - * @param {Mixed} value The value to check. - * @returns {Boolean} Returns `true`, if the `value` is finite, else `false`. + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is an error object, else `false`. * @example * - * _.isFinite(-101); + * _.isError(new Error); + * // => true + * + * _.isError(Error); + * // => false + */ + function isError(value) { + return (isObjectLike(value) && typeof value.message == 'string' && objToString.call(value) == errorTag) || false; + } + + /** + * Checks if `value` is a finite primitive number. + * + * **Note:** This method is based on ES `Number.isFinite`. See the + * [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-number.isfinite) + * for more details. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is a finite number, else `false`. + * @example + * + * _.isFinite(10); * // => true * * _.isFinite('10'); - * // => true + * // => false * * _.isFinite(true); * // => false * - * _.isFinite(''); + * _.isFinite(Object(10)); * // => false * * _.isFinite(Infinity); * // => false */ - function isFinite(value) { - return nativeIsFinite(value) && !nativeIsNaN(parseFloat(value)); - } + var isFinite = nativeNumIsFinite || function(value) { + return typeof value == 'number' && nativeIsFinite(value); + }; /** - * Checks if `value` is a function. + * Checks if `value` is classified as a `Function` object. * * @static * @memberOf _ - * @category Objects - * @param {Mixed} value The value to check. - * @returns {Boolean} Returns `true`, if the `value` is a function, else `false`. + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. * @example * * _.isFunction(_); * // => true + * + * _.isFunction(/abc/); + * // => false */ function isFunction(value) { - return typeof value == 'function'; + // Avoid a Chakra JIT bug in compatibility modes of IE 11. + // See https://github.com/jashkenas/underscore/issues/1621 for more details. + return typeof value == 'function' || false; } - // fallback for older versions of Chrome and Safari - if (isFunction(/x/)) { + // Fallback for environments that return incorrect `typeof` operator results. + if (isFunction(/x/) || (Uint8Array && !isFunction(Uint8Array))) { isFunction = function(value) { - return typeof value == 'function' && toString.call(value) == funcClass; + // The use of `Object#toString` avoids issues with the `typeof` operator + // in older versions of Chrome and Safari which return 'function' for regexes + // and Safari 8 equivalents which return 'object' for typed array constructors. + return objToString.call(value) == funcTag; }; } /** - * Checks if `value` is the language type of Object. + * Checks if `value` is the language type of `Object`. * (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`) * + * **Note:** See the [ES5 spec](https://es5.github.io/#x8) for more details. + * * @static * @memberOf _ - * @category Objects - * @param {Mixed} value The value to check. - * @returns {Boolean} Returns `true`, if the `value` is an object, else `false`. + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is an object, else `false`. * @example * * _.isObject({}); @@ -2013,24 +7811,86 @@ * // => false */ function isObject(value) { - // check if the value is the ECMAScript language type of Object - // http://es5.github.com/#x8 - // and avoid a V8 bug - // http://code.google.com/p/v8/issues/detail?id=2291 - return !!(value && objectTypes[typeof value]); + // Avoid a V8 JIT bug in Chrome 19-20. + // See https://code.google.com/p/v8/issues/detail?id=2291 for more details. + var type = typeof value; + return type == 'function' || (value && type == 'object') || false; + } + + /** + * Performs a deep comparison between `object` and `source` to determine if + * `object` contains equivalent property values. If `customizer` is provided + * it is invoked to compare values. If `customizer` returns `undefined` + * comparisons are handled by the method instead. The `customizer` is bound + * to `thisArg` and invoked with three arguments; (value, other, index|key). + * + * **Note:** This method supports comparing properties of arrays, booleans, + * `Date` objects, numbers, `Object` objects, regexes, and strings. Functions + * and DOM nodes are **not** supported. Provide a customizer function to extend + * support for comparing other values. + * + * @static + * @memberOf _ + * @category Lang + * @param {Object} source The object to inspect. + * @param {Object} source The object of property values to match. + * @param {Function} [customizer] The function to customize comparing values. + * @param {*} [thisArg] The `this` binding of `customizer`. + * @returns {boolean} Returns `true` if `object` is a match, else `false`. + * @example + * + * var object = { 'user': 'fred', 'age': 40 }; + * + * _.isMatch(object, { 'age': 40 }); + * // => true + * + * _.isMatch(object, { 'age': 36 }); + * // => false + * + * // using a customizer callback + * var object = { 'greeting': 'hello' }; + * var source = { 'greeting': 'hi' }; + * + * _.isMatch(object, source, function(value, other) { + * return _.every([value, other], RegExp.prototype.test, /^h(?:i|ello)$/) || undefined; + * }); + * // => true + */ + function isMatch(object, source, customizer, thisArg) { + var props = keys(source), + length = props.length; + + customizer = typeof customizer == 'function' && bindCallback(customizer, thisArg, 3); + if (!customizer && length == 1) { + var key = props[0], + value = source[key]; + + if (isStrictComparable(value)) { + return object != null && value === object[key] && hasOwnProperty.call(object, key); + } + } + var values = Array(length), + strictCompareFlags = Array(length); + + while (length--) { + value = values[length] = source[props[length]]; + strictCompareFlags[length] = isStrictComparable(value); + } + return baseIsMatch(object, props, values, strictCompareFlags, customizer); } /** * Checks if `value` is `NaN`. * - * Note: This is not the same as native `isNaN`, which will return `true` for - * `undefined` and other values. See http://es5.github.com/#x15.1.2.4. + * **Note:** This method is not the same as native `isNaN` which returns `true` + * for `undefined` and other non-numeric values. See the [ES5 spec](https://es5.github.io/#x15.1.2.4) + * for more details. * * @static * @memberOf _ - * @category Objects - * @param {Mixed} value The value to check. - * @returns {Boolean} Returns `true`, if the `value` is `NaN`, else `false`. + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is `NaN`, else `false`. * @example * * _.isNaN(NaN); @@ -2046,9 +7906,35 @@ * // => 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 + // An `NaN` primitive is the only value that is not equal to itself. + // Perform the `toStringTag` check first to avoid errors with some host objects in IE. + return isNumber(value) && value != +value; + } + + /** + * Checks if `value` is a native function. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is a native function, else `false`. + * @example + * + * _.isNative(Array.prototype.push); + * // => true + * + * _.isNative(_); + * // => false + */ + function isNative(value) { + if (value == null) { + return false; + } + if (objToString.call(value) == funcTag) { + return reNative.test(fnToString.call(value)); + } + return (isObjectLike(value) && reHostCtor.test(value)) || false; } /** @@ -2056,15 +7942,15 @@ * * @static * @memberOf _ - * @category Objects - * @param {Mixed} value The value to check. - * @returns {Boolean} Returns `true`, if the `value` is `null`, else `false`. + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is `null`, else `false`. * @example * * _.isNull(null); * // => true * - * _.isNull(undefined); + * _.isNull(void 0); * // => false */ function isNull(value) { @@ -2072,52 +7958,67 @@ } /** - * Checks if `value` is a number. + * Checks if `value` is classified as a `Number` primitive or object. + * + * **Note:** To exclude `Infinity`, `-Infinity`, and `NaN`, which are classified + * as numbers, use the `_.isFinite` method. * * @static * @memberOf _ - * @category Objects - * @param {Mixed} value The value to check. - * @returns {Boolean} Returns `true`, if the `value` is a number, else `false`. + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. * @example * - * _.isNumber(8.4 * 5); + * _.isNumber(8.4); * // => true + * + * _.isNumber(NaN); + * // => true + * + * _.isNumber('8.4'); + * // => false */ function isNumber(value) { - return typeof value == 'number' || toString.call(value) == numberClass; + return typeof value == 'number' || (isObjectLike(value) && objToString.call(value) == numberTag) || false; } /** - * Checks if a given `value` is an object created by the `Object` constructor. + * Checks if `value` is a plain object, that is, an object created by the + * `Object` constructor or one with a `[[Prototype]]` of `null`. + * + * **Note:** This method assumes objects created by the `Object` constructor + * have no inherited enumerable properties. * * @static * @memberOf _ - * @category Objects - * @param {Mixed} value The value to check. - * @returns {Boolean} Returns `true`, if `value` is a plain object, else `false`. + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is a plain object, else `false`. * @example * - * function Stooge(name, age) { - * this.name = name; - * this.age = age; + * function Foo() { + * this.a = 1; * } * - * _.isPlainObject(new Stooge('moe', 40)); + * _.isPlainObject(new Foo); * // => false * * _.isPlainObject([1, 2, 3]); * // => false * - * _.isPlainObject({ 'name': 'moe', 'age': 40 }); + * _.isPlainObject({ 'x': 0, 'y': 0 }); + * // => true + * + * _.isPlainObject(Object.create(null)); * // => true */ var isPlainObject = !getPrototypeOf ? shimIsPlainObject : function(value) { - if (!(value && toString.call(value) == objectClass) || (!support.argsClass && isArguments(value))) { + if (!(value && objToString.call(value) == objectTag)) { return false; } var valueOf = value.valueOf, - objProto = typeof valueOf == 'function' && (objProto = getPrototypeOf(valueOf)) && getPrototypeOf(objProto); + objProto = isNative(valueOf) && (objProto = getPrototypeOf(valueOf)) && getPrototypeOf(objProto); return objProto ? (value == objProto || getPrototypeOf(value) == objProto) @@ -2125,37 +8026,63 @@ }; /** - * Checks if `value` is a regular expression. + * Checks if `value` is classified as a `RegExp` object. * * @static * @memberOf _ - * @category Objects - * @param {Mixed} value The value to check. - * @returns {Boolean} Returns `true`, if the `value` is a regular expression, else `false`. + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. * @example * - * _.isRegExp(/moe/); + * _.isRegExp(/abc/); * // => true + * + * _.isRegExp('/abc/'); + * // => false */ function isRegExp(value) { - return !!(value && objectTypes[typeof value]) && toString.call(value) == regexpClass; + return (isObjectLike(value) && objToString.call(value) == regexpTag) || false; } /** - * Checks if `value` is a string. + * Checks if `value` is classified as a `String` primitive or object. * * @static * @memberOf _ - * @category Objects - * @param {Mixed} value The value to check. - * @returns {Boolean} Returns `true`, if the `value` is a string, else `false`. + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. * @example * - * _.isString('moe'); + * _.isString('abc'); * // => true + * + * _.isString(1); + * // => false */ function isString(value) { - return typeof value == 'string' || toString.call(value) == stringClass; + return typeof value == 'string' || (isObjectLike(value) && objToString.call(value) == stringTag) || false; + } + + /** + * Checks if `value` is classified as a typed array. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isTypedArray(new Uint8Array); + * // => true + * + * _.isTypedArray([]); + * // => false + */ + function isTypedArray(value) { + return (isObjectLike(value) && isLength(value.length) && typedArrayTags[objToString.call(value)]) || false; } /** @@ -2163,222 +8090,701 @@ * * @static * @memberOf _ - * @category Objects - * @param {Mixed} value The value to check. - * @returns {Boolean} Returns `true`, if the `value` is `undefined`, else `false`. + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is `undefined`, else `false`. * @example * * _.isUndefined(void 0); * // => true + * + * _.isUndefined(null); + * // => false */ function isUndefined(value) { return typeof value == 'undefined'; } /** - * 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` function - * is passed, it will be executed to produce the merged values of the destination - * and source properties. If `callback` returns `undefined`, merging will be - * handled by the method instead. The `callback` is bound to `thisArg` and - * invoked with two arguments; (objectValue, sourceValue). + * Converts `value` to an array. * * @static * @memberOf _ - * @category Objects - * @param {Object} object The destination object. - * @param {Object} [source1, source2, ...] The source objects. - * @param {Function} [callback] The function to customize merging properties. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @param- {Object} [deepIndicator] Indicates that `stackA` and `stackB` are - * arrays of traversed objects, instead of source objects. - * @param- {Array} [stackA=[]] Tracks traversed source objects. - * @param- {Array} [stackB=[]] Associates values with source counterparts. - * @returns {Object} Returns the destination object. + * @category Lang + * @param {*} value The value to convert. + * @returns {Array} Returns the converted array. * @example * - * var names = { - * 'stooges': [ - * { 'name': 'moe' }, - * { 'name': 'larry' } - * ] - * }; - * - * var ages = { - * 'stooges': [ - * { 'age': 40 }, - * { 'age': 50 } - * ] - * }; - * - * _.merge(names, ages); - * // => { 'stooges': [{ 'name': 'moe', 'age': 40 }, { 'name': 'larry', 'age': 50 }] } - * - * 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() { return _.toArray(arguments).slice(1); })(1, 2, 3); + * // => [2, 3] */ - function merge(object, source, deepIndicator) { - var args = arguments, - index = 0, - length = 2; - - if (!isObject(object)) { - return object; + function toArray(value) { + var length = value ? value.length : 0; + if (!isLength(length)) { + return values(value); } - if (deepIndicator === indicatorObject) { - var callback = args[3], - stackA = args[4], - stackB = args[5]; - } else { - var initedStack = true; - stackA = getArray(); - stackB = getArray(); - - // allows working with `_.reduce` and `_.reduceRight` without - // using their `callback` arguments, `index|key` and `collection` - if (typeof deepIndicator != 'number') { - length = args.length; - } - if (length > 3 && typeof args[length - 2] == 'function') { - callback = lodash.createCallback(args[--length - 1], args[length--], 2); - } else if (length > 2 && typeof args[length - 1] == 'function') { - callback = args[--length]; - } + if (!length) { + return []; } - while (++index < length) { - (isArray(args[index]) ? forEach : forOwn)(args[index], 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) { - value = merge(value, source, indicatorObject, 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; - }); - } - - if (initedStack) { - releaseArray(stackA); - releaseArray(stackB); - } - return object; + return arrayCopy(value); } /** - * Creates a shallow clone of `object` excluding the specified properties. - * Property names may be specified as individual arguments or as arrays of - * property names. If a `callback` function is passed, it will be executed - * for each property in the `object`, omitting the properties `callback` - * returns truthy for. The `callback` is bound to `thisArg` and invoked - * with three arguments; (value, key, object). + * Converts `value` to a plain object flattening inherited enumerable + * properties of `value` to own properties of the plain object. * * @static * @memberOf _ - * @category Objects - * @param {Object} object The source object. - * @param {Function|String} callback|[prop1, prop2, ...] The properties to omit - * or the function called per iteration. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Object} Returns an object without the omitted properties. + * @category Lang + * @param {*} value The value to convert. + * @returns {Object} Returns the converted plain object. * @example * - * _.omit({ 'name': 'moe', 'age': 40 }, 'age'); - * // => { 'name': 'moe' } + * function Foo() { + * this.b = 2; + * } * - * _.omit({ 'name': 'moe', 'age': 40 }, function(value) { - * return typeof value == 'number'; - * }); - * // => { 'name': 'moe' } + * Foo.prototype.c = 3; + * + * _.assign({ 'a': 1 }, new Foo); + * // => { 'a': 1, 'b': 2 } + * + * _.assign({ 'a': 1 }, _.toPlainObject(new Foo)); + * // => { 'a': 1, 'b': 2, 'c': 3 } */ - function omit(object, callback, thisArg) { - var indexOf = getIndexOf(), - isFunc = typeof callback == 'function', + function toPlainObject(value) { + return baseCopy(value, keysIn(value)); + } + + /*------------------------------------------------------------------------*/ + + /** + * Assigns own enumerable properties of source object(s) to the destination + * object. Subsequent sources overwrite property assignments of previous sources. + * If `customizer` is provided it is invoked to produce the assigned values. + * The `customizer` is bound to `thisArg` and invoked with five arguments; + * (objectValue, sourceValue, key, object, source). + * + * @static + * @memberOf _ + * @alias extend + * @category Object + * @param {Object} object The destination object. + * @param {...Object} [sources] The source objects. + * @param {Function} [customizer] The function to customize assigning values. + * @param {*} [thisArg] The `this` binding of `customizer`. + * @returns {Object} Returns `object`. + * @example + * + * _.assign({ 'user': 'barney' }, { 'age': 40 }, { 'user': 'fred' }); + * // => { 'user': 'fred', 'age': 40 } + * + * // using a customizer callback + * var defaults = _.partialRight(_.assign, function(value, other) { + * return typeof value == 'undefined' ? other : value; + * }); + * + * defaults({ 'user': 'barney' }, { 'age': 36 }, { 'user': 'fred' }); + * // => { 'user': 'barney', 'age': 36 } + */ + var assign = createAssigner(baseAssign); + + /** + * 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 Object + * @param {Object} prototype The object to inherit from. + * @param {Object} [properties] The properties to assign to the object. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @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, guard) { + var result = baseCreate(prototype); + if (guard && isIterateeCall(prototype, properties, guard)) { + properties = null; + } + return properties ? baseCopy(properties, result, keys(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 are ignored. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The destination object. + * @param {...Object} [sources] The source objects. + * @returns {Object} Returns `object`. + * @example + * + * _.defaults({ 'user': 'barney' }, { 'age': 36 }, { 'user': 'fred' }); + * // => { 'user': 'barney', 'age': 36 } + */ + function defaults(object) { + if (object == null) { + return object; + } + var args = arrayCopy(arguments); + args.push(assignDefaults); + return assign.apply(undefined, args); + } + + /** + * This method is like `_.findIndex` except that it returns the key of the + * first element `predicate` returns truthy for, instead of the element itself. + * + * If a property name is provided for `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to search. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. If a property name or object is provided it is used to + * create a "_.property" or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {string|undefined} Returns the key of the matched element, else `undefined`. + * @example + * + * var users = { + * 'barney': { 'age': 36, 'active': true }, + * 'fred': { 'age': 40, 'active': false }, + * 'pebbles': { 'age': 1, 'active': true } + * }; + * + * _.findKey(users, function(chr) { return chr.age < 40; }); + * // => 'barney' (iteration order is not guaranteed) + * + * // using the "_.matches" callback shorthand + * _.findKey(users, { 'age': 1 }); + * // => 'pebbles' + * + * // using the "_.property" callback shorthand + * _.findKey(users, 'active'); + * // => 'barney' + */ + function findKey(object, predicate, thisArg) { + predicate = getCallback(predicate, thisArg, 3); + return baseFind(object, predicate, baseForOwn, true); + } + + /** + * 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 `predicate` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `predicate` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to search. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. If a property name or object is provided it is used to + * create a "_.property" or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {string|undefined} Returns the key of the matched element, else `undefined`. + * @example + * + * var users = { + * 'barney': { 'age': 36, 'active': true }, + * 'fred': { 'age': 40, 'active': false }, + * 'pebbles': { 'age': 1, 'active': true } + * }; + * + * _.findLastKey(users, function(chr) { return chr.age < 40; }); + * // => returns `pebbles` assuming `_.findKey` returns `barney` + * + * // using the "_.matches" callback shorthand + * _.findLastKey(users, { 'age': 36 }); + * // => 'barney' + * + * // using the "_.property" callback shorthand + * _.findLastKey(users, 'active'); + * // => 'pebbles' + */ + function findLastKey(object, predicate, thisArg) { + predicate = getCallback(predicate, thisArg, 3); + return baseFind(object, predicate, baseForOwnRight, true); + } + + /** + * Iterates over own and inherited enumerable properties of an object invoking + * `iteratee` for each property. The `iteratee` is bound to `thisArg` and invoked + * with three arguments; (value, key, object). Iterator functions may exit + * iteration early by explicitly returning `false`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Object} Returns `object`. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.forIn(new Foo, function(value, key) { + * console.log(key); + * }); + * // => logs 'a', 'b', and 'c' (iteration order is not guaranteed) + */ + function forIn(object, iteratee, thisArg) { + if (typeof iteratee != 'function' || typeof thisArg != 'undefined') { + iteratee = bindCallback(iteratee, thisArg, 3); + } + return baseFor(object, iteratee, keysIn); + } + + /** + * This method is like `_.forIn` except that it iterates over properties of + * `object` in the opposite order. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Object} Returns `object`. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.forInRight(new Foo, function(value, key) { + * console.log(key); + * }); + * // => logs 'c', 'b', and 'a' assuming `_.forIn ` logs 'a', 'b', and 'c' + */ + function forInRight(object, iteratee, thisArg) { + iteratee = bindCallback(iteratee, thisArg, 3); + return baseForRight(object, iteratee, keysIn); + } + + /** + * Iterates over own enumerable properties of an object invoking `iteratee` + * for each property. The `iteratee` is bound to `thisArg` and invoked with + * three arguments; (value, key, object). Iterator functions may exit iteration + * early by explicitly returning `false`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Object} Returns `object`. + * @example + * + * _.forOwn({ '0': 'zero', '1': 'one', 'length': 2 }, function(n, key) { + * console.log(key); + * }); + * // => logs '0', '1', and 'length' (iteration order is not guaranteed) + */ + function forOwn(object, iteratee, thisArg) { + if (typeof iteratee != 'function' || typeof thisArg != 'undefined') { + iteratee = bindCallback(iteratee, thisArg, 3); + } + return baseForOwn(object, iteratee); + } + + /** + * This method is like `_.forOwn` except that it iterates over properties of + * `object` in the opposite order. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Object} Returns `object`. + * @example + * + * _.forOwnRight({ '0': 'zero', '1': 'one', 'length': 2 }, function(n, key) { + * console.log(key); + * }); + * // => logs 'length', '1', and '0' assuming `_.forOwn` logs '0', '1', and 'length' + */ + function forOwnRight(object, iteratee, thisArg) { + iteratee = bindCallback(iteratee, thisArg, 3); + return baseForRight(object, iteratee, keys); + } + + /** + * Creates an array of function property names from all enumerable properties, + * own and inherited, of `object`. + * + * @static + * @memberOf _ + * @alias methods + * @category Object + * @param {Object} object The object to inspect. + * @returns {Array} Returns the new array of property names. + * @example + * + * _.functions(_); + * // => ['all', 'any', 'bind', ...] + */ + function functions(object) { + return baseFunctions(object, keysIn(object)); + } + + /** + * Checks if `key` exists as a direct property of `object` instead of an + * inherited property. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to inspect. + * @param {string} key The key 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 `object`. + * If `object` contains duplicate values, subsequent values overwrite property + * assignments of previous values unless `multiValue` is `true`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to invert. + * @param {boolean} [multiValue] Allow multiple values per key. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {Object} Returns the new inverted object. + * @example + * + * _.invert({ 'first': 'fred', 'second': 'barney' }); + * // => { 'fred': 'first', 'barney': 'second' } + * + * // without `multiValue` + * _.invert({ 'first': 'fred', 'second': 'barney', 'third': 'fred' }); + * // => { 'fred': 'third', 'barney': 'second' } + * + * // with `multiValue` + * _.invert({ 'first': 'fred', 'second': 'barney', 'third': 'fred' }, true); + * // => { 'fred': ['first', 'third'], 'barney': ['second'] } + */ + function invert(object, multiValue, guard) { + if (guard && isIterateeCall(object, multiValue, guard)) { + multiValue = null; + } + var index = -1, + props = keys(object), + length = props.length, result = {}; - if (isFunc) { - callback = lodash.createCallback(callback, thisArg); - } else { - var props = concat.apply(arrayRef, nativeSlice.call(arguments, 1)); - } - forIn(object, function(value, key, object) { - if (isFunc - ? !callback(value, key, object) - : indexOf(props, key) < 0 - ) { - result[key] = value; + while (++index < length) { + var key = props[index], + value = object[key]; + + if (multiValue) { + if (hasOwnProperty.call(result, value)) { + result[value].push(key); + } else { + result[value] = [key]; + } } + else { + result[value] = key; + } + } + return result; + } + + /** + * Creates an array of the own enumerable property names of `object`. + * + * **Note:** Non-object values are coerced to objects. See the + * [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.keys) + * for more details. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to inspect. + * @returns {Array} Returns the array of property names. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.keys(new Foo); + * // => ['a', 'b'] (iteration order is not guaranteed) + * + * _.keys('hi'); + * // => ['0', '1'] + */ + var keys = !nativeKeys ? shimKeys : function(object) { + if (object) { + var Ctor = object.constructor, + length = object.length; + } + if ((typeof Ctor == 'function' && Ctor.prototype === object) || + (typeof object != 'function' && (length && isLength(length)))) { + return shimKeys(object); + } + return isObject(object) ? nativeKeys(object) : []; + }; + + /** + * Creates an array of the own and inherited enumerable property names of `object`. + * + * **Note:** Non-object values are coerced to objects. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to inspect. + * @returns {Array} Returns the array of property names. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.keysIn(new Foo); + * // => ['a', 'b', 'c'] (iteration order is not guaranteed) + */ + function keysIn(object) { + if (object == null) { + return []; + } + if (!isObject(object)) { + object = Object(object); + } + var length = object.length; + length = (length && isLength(length) && + (isArray(object) || (support.nonEnumArgs && isArguments(object))) && length) || 0; + + var Ctor = object.constructor, + index = -1, + isProto = typeof Ctor == 'function' && Ctor.prototype == object, + result = Array(length), + skipIndexes = length > 0; + + while (++index < length) { + result[index] = (index + ''); + } + for (var key in object) { + if (!(skipIndexes && isIndex(key, length)) && + !(key == 'constructor' && (isProto || !hasOwnProperty.call(object, key)))) { + result.push(key); + } + } + return result; + } + + /** + * Creates an object with the same keys as `object` and values generated by + * running each own enumerable property of `object` through `iteratee`. The + * iteratee function is bound to `thisArg` and invoked with three arguments; + * (value, key, object). + * + * If a property name is provided for `iteratee` the created "_.property" + * style callback returns the property value of the given element. + * + * If an object is provided for `iteratee` the created "_.matches" style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to iterate over. + * @param {Function|Object|string} [iteratee=_.identity] The function invoked + * per iteration. If a property name or object is provided it is used to + * create a "_.property" or "_.matches" style callback respectively. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Object} Returns the new mapped object. + * @example + * + * _.mapValues({ 'a': 1, 'b': 2, 'c': 3} , function(n) { return n * 3; }); + * // => { 'a': 3, 'b': 6, 'c': 9 } + * + * var users = { + * 'fred': { 'user': 'fred', 'age': 40 }, + * 'pebbles': { 'user': 'pebbles', 'age': 1 } + * }; + * + * // using the "_.property" callback shorthand + * _.mapValues(users, 'age'); + * // => { 'fred': 40, 'pebbles': 1 } (iteration order is not guaranteed) + */ + function mapValues(object, iteratee, thisArg) { + var result = {}; + iteratee = getCallback(iteratee, thisArg, 3); + + baseForOwn(object, function(value, key, object) { + result[key] = iteratee(value, key, object); }); return result; } /** - * Creates a two dimensional array of the given object's key-value pairs, - * i.e. `[[key1, value1], [key2, value2]]`. + * Recursively merges own enumerable properties of the source object(s), that + * don't resolve to `undefined` into the destination object. Subsequent sources + * overwrite property assignments of previous sources. If `customizer` is + * provided it is invoked to produce the merged values of the destination and + * source properties. If `customizer` returns `undefined` merging is handled + * by the method instead. The `customizer` is bound to `thisArg` and invoked + * with five arguments; (objectValue, sourceValue, key, object, source). * * @static * @memberOf _ - * @category Objects - * @param {Object} object The object to inspect. - * @returns {Array} Returns new array of key-value pairs. + * @category Object + * @param {Object} object The destination object. + * @param {...Object} [sources] The source objects. + * @param {Function} [customizer] The function to customize merging properties. + * @param {*} [thisArg] The `this` binding of `customizer`. + * @returns {Object} Returns `object`. * @example * - * _.pairs({ 'moe': 30, 'larry': 40 }); - * // => [['moe', 30], ['larry', 40]] (order is not guaranteed) + * var users = { + * 'data': [{ 'user': 'barney' }, { 'user': 'fred' }] + * }; + * + * var ages = { + * 'data': [{ 'age': 36 }, { 'age': 40 }] + * }; + * + * _.merge(users, ages); + * // => { 'data': [{ 'user': 'barney', 'age': 36 }, { 'user': 'fred', 'age': 40 }] } + * + * // using a customizer callback + * var object = { + * 'fruits': ['apple'], + * 'vegetables': ['beet'] + * }; + * + * var other = { + * 'fruits': ['banana'], + * 'vegetables': ['carrot'] + * }; + * + * _.merge(object, other, function(a, b) { + * return _.isArray(a) ? a.concat(b) : undefined; + * }); + * // => { 'fruits': ['apple', 'banana'], 'vegetables': ['beet', 'carrot'] } + */ + var merge = createAssigner(baseMerge); + + /** + * The opposite of `_.pick`; this method creates an object composed of the + * own and inherited enumerable properties of `object` that are not omitted. + * Property names may be specified as individual arguments or as arrays of + * property names. If `predicate` is provided it is invoked for each property + * of `object` omitting the properties `predicate` returns truthy for. The + * predicate is bound to `thisArg` and invoked with three arguments; + * (value, key, object). + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The source object. + * @param {Function|...(string|string[])} [predicate] The function invoked per + * iteration or property names to omit, specified as individual property + * names or arrays of property names. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {Object} Returns the new object. + * @example + * + * var object = { 'user': 'fred', 'age': 40 }; + * + * _.omit(object, 'age'); + * // => { 'user': 'fred' } + * + * _.omit(object, _.isNumber); + * // => { 'user': 'fred' } + */ + function omit(object, predicate, thisArg) { + if (object == null) { + return {}; + } + if (typeof predicate != 'function') { + var props = arrayMap(baseFlatten(arguments, false, false, 1), String); + return pickByArray(object, baseDifference(keysIn(object), props)); + } + predicate = bindCallback(predicate, thisArg, 3); + return pickByCallback(object, function(value, key, object) { + return !predicate(value, key, object); + }); + } + + /** + * Creates a two dimensional array of the key-value pairs for `object`, + * e.g. `[[key1, value1], [key2, value2]]`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to inspect. + * @returns {Array} Returns the new array of key-value pairs. + * @example + * + * _.pairs({ 'barney': 36, 'fred': 40 }); + * // => [['barney', 36], ['fred', 40]] (iteration order is not guaranteed) */ function pairs(object) { var index = -1, @@ -2394,2723 +8800,1199 @@ } /** - * Creates a shallow clone of `object` composed of the specified properties. - * Property names may be specified as individual arguments or as arrays of property - * names. If `callback` is passed, it will be executed for each property in the - * `object`, picking the properties `callback` returns truthy for. The `callback` - * is bound to `thisArg` and invoked with three arguments; (value, key, object). + * Creates an object composed of the picked `object` properties. Property + * names may be specified as individual arguments or as arrays of property + * names. If `predicate` is provided it is invoked for each property of `object` + * picking the properties `predicate` returns truthy for. The predicate is + * bound to `thisArg` and invoked with three arguments; (value, key, object). * * @static * @memberOf _ - * @category Objects + * @category Object * @param {Object} object The source object. - * @param {Array|Function|String} callback|[prop1, prop2, ...] The function called - * per iteration or properties to pick, either as individual arguments or arrays. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Object} Returns an object composed of the picked properties. + * @param {Function|...(string|string[])} [predicate] The function invoked per + * iteration or property names to pick, specified as individual property + * names or arrays of property names. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {Object} Returns the new object. * @example * - * _.pick({ 'name': 'moe', '_userid': 'moe1' }, 'name'); - * // => { 'name': 'moe' } + * var object = { 'user': 'fred', 'age': 40 }; * - * _.pick({ 'name': 'moe', '_userid': 'moe1' }, function(value, key) { - * return key.charAt(0) != '_'; - * }); - * // => { 'name': 'moe' } + * _.pick(object, 'user'); + * // => { 'user': 'fred' } + * + * _.pick(object, _.isString); + * // => { 'user': 'fred' } */ - function pick(object, callback, thisArg) { - var result = {}; - if (typeof callback != 'function') { - var index = -1, - props = concat.apply(arrayRef, nativeSlice.call(arguments, 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); - forIn(object, function(value, key, object) { - if (callback(value, key, object)) { - result[key] = value; - } - }); + function pick(object, predicate, thisArg) { + if (object == null) { + return {}; } - return result; + return typeof predicate == 'function' + ? pickByCallback(object, bindCallback(predicate, thisArg, 3)) + : pickByArray(object, baseFlatten(arguments, false, false, 1)); } /** - * An alternative to `_.reduce`, this method transforms an `object` to a new - * `accumulator` object which is the result of running each of its elements - * through the `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`. + * Resolves the value of property `key` on `object`. If the value of `key` is + * a function it is invoked with the `this` binding of `object` and its result + * is returned, else the property value is returned. If the property value is + * `undefined` the `defaultValue` is used in its place. * * @static * @memberOf _ - * @category Objects - * @param {Array|Object} collection The collection to iterate over. - * @param {Function} [callback=identity] The function called per iteration. - * @param {Mixed} [accumulator] The custom accumulator value. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Mixed} Returns the accumulated value. + * @category Object + * @param {Object} object The object to query. + * @param {string} key The key of the property to resolve. + * @param {*} [defaultValue] The value returned if the property value + * resolves to `undefined`. + * @returns {*} Returns the resolved 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; + * var object = { 'user': 'fred', 'age': _.constant(40) }; + * + * _.result(object, 'user'); + * // => 'fred' + * + * _.result(object, 'age'); + * // => 40 + * + * _.result(object, 'status', 'busy'); + * // => 'busy' + * + * _.result(object, 'status', _.constant('busy')); + * // => 'busy' + */ + function result(object, key, defaultValue) { + var value = object == null ? undefined : object[key]; + if (typeof value == 'undefined') { + value = defaultValue; + } + return isFunction(value) ? value.call(object) : value; + } + + /** + * 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 `iteratee`, with each invocation potentially mutating + * the `accumulator` object. The `iteratee` is bound to `thisArg` and invoked + * with four arguments; (accumulator, value, key, object). Iterator functions + * may exit iteration early by explicitly returning `false`. + * + * @static + * @memberOf _ + * @category Object + * @param {Array|Object} object The object to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @param {*} [accumulator] The custom accumulator value. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {*} Returns the accumulated value. + * @example + * + * var squares = _.transform([1, 2, 3, 4, 5, 6], function(result, n) { + * n *= n; + * if (n % 2) { + * return result.push(n) < 3; * } * }); * // => [1, 9, 25] * - * var mapped = _.transform({ 'a': 1, 'b': 2, 'c': 3 }, function(result, num, key) { - * result[key] = num * 3; + * var mapped = _.transform({ 'a': 1, 'b': 2, 'c': 3 }, function(result, n, key) { + * result[key] = n * 3; * }); * // => { 'a': 3, 'b': 6, 'c': 9 } */ - function transform(object, callback, accumulator, thisArg) { - var isArr = isArray(object); - callback = lodash.createCallback(callback, thisArg, 4); + function transform(object, iteratee, accumulator, thisArg) { + var isArr = isArray(object) || isTypedArray(object); + iteratee = getCallback(iteratee, thisArg, 4); if (accumulator == null) { - if (isArr) { - accumulator = []; + if (isArr || isObject(object)) { + var Ctor = object.constructor; + if (isArr) { + accumulator = isArray(object) ? new Ctor : []; + } else { + accumulator = baseCreate(typeof Ctor == 'function' && Ctor.prototype); + } } else { - var ctor = object && object.constructor, - proto = ctor && ctor.prototype; - - accumulator = createObject(proto); + accumulator = {}; } } - (isArr ? basicEach : forOwn)(object, function(value, index, object) { - return callback(accumulator, value, index, object); + (isArr ? arrayEach : baseForOwn)(object, function(value, index, object) { + return iteratee(accumulator, value, index, object); }); return accumulator; } /** - * Creates an array composed of the own enumerable property values of `object`. + * Creates an array of the own enumerable property values of `object`. + * + * **Note:** Non-object values are coerced to objects. * * @static * @memberOf _ - * @category Objects - * @param {Object} object The object to inspect. - * @returns {Array} Returns a new array of property values. + * @category Object + * @param {Object} object The object to query. + * @returns {Array} Returns the array of property values. * @example * - * _.values({ 'one': 1, 'two': 2, 'three': 3 }); - * // => [1, 2, 3] (order is not guaranteed) + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.values(new Foo); + * // => [1, 2] (iteration order is not guaranteed) + * + * _.values('hi'); + * // => ['h', 'i'] */ 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; + return baseValues(object, keys(object)); } - /*--------------------------------------------------------------------------*/ - /** - * 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. + * Creates an array of the own and inherited enumerable property values + * of `object`. + * + * **Note:** Non-object values are coerced to objects. * * @static * @memberOf _ - * @category Collections - * @param {Array|Object|String} collection The collection to iterate over. - * @param {Array|Number|String} [index1, index2, ...] The indexes of - * `collection` to retrieve, either as individual arguments or arrays. - * @returns {Array} Returns a new array of elements corresponding to the - * provided indexes. + * @category Object + * @param {Object} object The object to query. + * @returns {Array} Returns the array of property values. * @example * - * _.at(['a', 'b', 'c', 'd', 'e'], [0, 2, 4]); - * // => ['a', 'c', 'e'] + * function Foo() { + * this.a = 1; + * this.b = 2; + * } * - * _.at(['moe', 'larry', 'curly'], 0, 2); - * // => ['moe', 'curly'] + * Foo.prototype.c = 3; + * + * _.valuesIn(new Foo); + * // => [1, 2, 3] (iteration order is not guaranteed) */ - function at(collection) { - var index = -1, - props = concat.apply(arrayRef, nativeSlice.call(arguments, 1)), - length = props.length, - result = Array(length); - - if (support.unindexedChars && isString(collection)) { - collection = collection.split(''); - } - while(++index < length) { - result[index] = collection[props[index]]; - } - return result; + function valuesIn(object) { + return baseValues(object, keysIn(object)); } + /*------------------------------------------------------------------------*/ + /** - * Checks if a given `target` element is present in a `collection` using strict - * equality for comparisons, i.e. `===`. If `fromIndex` is negative, it is used - * as the offset from the end of the collection. + * Produces a random number between `min` and `max` (inclusive). If only one + * argument is provided a number between `0` and the given number is returned. + * If `floating` is `true`, or either `min` or `max` are floats, a floating-point + * number is returned instead of an integer. * * @static * @memberOf _ - * @alias include - * @category Collections - * @param {Array|Object|String} collection The collection to iterate over. - * @param {Mixed} target The value to check for. - * @param {Number} [fromIndex=0] The index to search from. - * @returns {Boolean} Returns `true` if the `target` element is found, else `false`. + * @category Number + * @param {number} [min=0] The minimum possible value. + * @param {number} [max=1] The maximum possible value. + * @param {boolean} [floating] Specify returning a floating-point number. + * @returns {number} Returns the random number. * @example * - * _.contains([1, 2, 3], 1); + * _.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) { + if (floating && isIterateeCall(min, max, floating)) { + max = floating = null; + } + var noMin = min == null, + noMax = max == null; + + if (floating == null) { + if (noMax && typeof min == 'boolean') { + floating = min; + min = 1; + } + else if (typeof max == 'boolean') { + floating = max; + noMax = true; + } + } + if (noMin && noMax) { + max = 1; + noMax = false; + } + 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); + } + + /*------------------------------------------------------------------------*/ + + /** + * Converts `string` to camel case. + * See [Wikipedia](https://en.wikipedia.org/wiki/CamelCase) for more details. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to convert. + * @returns {string} Returns the camel cased string. + * @example + * + * _.camelCase('Foo Bar'); + * // => 'fooBar' + * + * _.camelCase('--foo-bar'); + * // => 'fooBar' + * + * _.camelCase('__foo_bar__'); + * // => 'fooBar' + */ + var camelCase = createCompounder(function(result, word, index) { + word = word.toLowerCase(); + return index ? (result + word.charAt(0).toUpperCase() + word.slice(1)) : word; + }); + + /** + * Capitalizes the first character of `string`. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to capitalize. + * @returns {string} Returns the capitalized string. + * @example + * + * _.capitalize('fred'); + * // => 'Fred' + */ + function capitalize(string) { + string = baseToString(string); + return string && (string.charAt(0).toUpperCase() + string.slice(1)); + } + + /** + * Deburrs `string` by converting latin-1 supplementary letters to basic latin letters. + * See [Wikipedia](https://en.wikipedia.org/wiki/Latin-1_Supplement_(Unicode_block)#Character_table) + * for more details. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to deburr. + * @returns {string} Returns the deburred string. + * @example + * + * _.deburr('déjà vu'); + * // => 'deja vu' + */ + function deburr(string) { + string = baseToString(string); + return string && string.replace(reLatin1, deburrLetter); + } + + /** + * Checks if `string` ends with the given target string. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to search. + * @param {string} [target] The string to search for. + * @param {number} [position=string.length] The position to search from. + * @returns {boolean} Returns `true` if `string` ends with `target`, else `false`. + * @example + * + * _.endsWith('abc', 'c'); * // => true * - * _.contains([1, 2, 3], 1, 2); + * _.endsWith('abc', 'b'); * // => false * - * _.contains({ 'name': 'moe', 'age': 40 }, 'moe'); - * // => true - * - * _.contains('curly', 'ur'); + * _.endsWith('abc', 'b', 2); * // => true */ - function contains(collection, target, fromIndex) { - var index = -1, - indexOf = getIndexOf(), - length = collection ? collection.length : 0, - result = false; + function endsWith(string, target, position) { + string = baseToString(string); + target = (target + ''); - fromIndex = (fromIndex < 0 ? nativeMax(0, length + fromIndex) : fromIndex) || 0; - if (length && typeof length == 'number') { - result = (isString(collection) - ? collection.indexOf(target, fromIndex) - : indexOf(collection, target, fromIndex) - ) > -1; - } else { - basicEach(collection, function(value) { - if (++index >= fromIndex) { - return !(result = value === target); - } - }); + var length = string.length; + position = (typeof position == 'undefined' ? length : nativeMin(position < 0 ? 0 : (+position || 0), length)) - target.length; + return position >= 0 && string.indexOf(target, position) == position; + } + + /** + * Converts the characters "&", "<", ">", '"', "'", and '`', in `string` to + * their corresponding HTML entities. + * + * **Note:** No other characters are escaped. To escape additional characters + * use a third-party library like [_he_](https://mths.be/he). + * + * Though the ">" character is escaped for symmetry, characters like + * ">" and "/" don't require escaping in HTML and have no special meaning + * unless they're part of a tag or unquoted attribute value. + * See [Mathias Bynens's article](https://mathiasbynens.be/notes/ambiguous-ampersands) + * (under "semi-related fun fact") for more details. + * + * Backticks are escaped because in Internet Explorer < 9, they can break out + * of attribute values or HTML comments. See [#102](https://html5sec.org/#102), + * [#108](https://html5sec.org/#108), and [#133](https://html5sec.org/#133) of + * the [HTML5 Security Cheatsheet](https://html5sec.org/) for more details. + * + * When working with HTML you should always quote attribute values to reduce + * XSS vectors. See [Ryan Grove's article](http://wonko.com/post/html-escaping) + * for more details. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to escape. + * @returns {string} Returns the escaped string. + * @example + * + * _.escape('fred, barney, & pebbles'); + * // => 'fred, barney, & pebbles' + */ + function escape(string) { + // Reset `lastIndex` because in IE < 9 `String#replace` does not. + string = baseToString(string); + return (string && reHasUnescapedHtml.test(string)) + ? string.replace(reUnescapedHtml, escapeHtmlChar) + : string; + } + + /** + * Escapes the `RegExp` special characters "\", "^", "$", ".", "|", "?", "*", + * "+", "(", ")", "[", "]", "{" and "}" in `string`. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to escape. + * @returns {string} Returns the escaped string. + * @example + * + * _.escapeRegExp('[lodash](https://lodash.com/)'); + * // => '\[lodash\]\(https://lodash\.com/\)' + */ + function escapeRegExp(string) { + string = baseToString(string); + return (string && reHasRegExpChars.test(string)) + ? string.replace(reRegExpChars, '\\$&') + : string; + } + + /** + * Converts `string` to kebab case (a.k.a. spinal case). + * See [Wikipedia](https://en.wikipedia.org/wiki/Letter_case#Special_case_styles) for + * more details. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to convert. + * @returns {string} Returns the kebab cased string. + * @example + * + * _.kebabCase('Foo Bar'); + * // => 'foo-bar' + * + * _.kebabCase('fooBar'); + * // => 'foo-bar' + * + * _.kebabCase('__foo_bar__'); + * // => 'foo-bar' + */ + var kebabCase = createCompounder(function(result, word, index) { + return result + (index ? '-' : '') + word.toLowerCase(); + }); + + /** + * Pads `string` on the left and right sides if it is shorter then the given + * padding length. The `chars` string may be truncated if the number of padding + * characters can't be evenly divided by the padding length. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to pad. + * @param {number} [length=0] The padding length. + * @param {string} [chars=' '] The string used as padding. + * @returns {string} Returns the padded string. + * @example + * + * _.pad('abc', 8); + * // => ' abc ' + * + * _.pad('abc', 8, '_-'); + * // => '_-abc_-_' + * + * _.pad('abc', 3); + * // => 'abc' + */ + function pad(string, length, chars) { + string = baseToString(string); + length = +length; + + var strLength = string.length; + if (strLength >= length || !nativeIsFinite(length)) { + return string; } - return result; + var mid = (length - strLength) / 2, + leftLength = floor(mid), + rightLength = ceil(mid); + + chars = createPad('', rightLength, chars); + return chars.slice(0, leftLength) + string + chars; } /** - * Creates an object composed of keys returned from running each element of the - * `collection` through the given `callback`. The corresponding value of each key - * is the number of times the key was returned by the `callback`. The `callback` - * is bound to `thisArg` and invoked with three arguments; (value, index|key, collection). - * - * If a property name is passed for `callback`, the created "_.pluck" style - * callback will return the property value of the given element. - * - * If an object is passed for `callback`, the created "_.where" style callback - * will return `true` for elements that have the properties of the given object, - * else `false`. + * Pads `string` on the left side if it is shorter then the given padding + * length. The `chars` string may be truncated if the number of padding + * characters exceeds the padding length. * * @static * @memberOf _ - * @category Collections - * @param {Array|Object|String} collection The collection to iterate over. - * @param {Function|Object|String} [callback=identity] The function called per - * iteration. If a property name or object is passed, it will be used to create - * a "_.pluck" or "_.where" style callback, respectively. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Object} Returns the composed aggregate object. + * @category String + * @param {string} [string=''] The string to pad. + * @param {number} [length=0] The padding length. + * @param {string} [chars=' '] The string used as padding. + * @returns {string} Returns the padded string. * @example * - * _.countBy([4.3, 6.1, 6.4], function(num) { return Math.floor(num); }); - * // => { '4': 1, '6': 2 } + * _.padLeft('abc', 6); + * // => ' abc' * - * _.countBy([4.3, 6.1, 6.4], function(num) { return this.floor(num); }, Math); - * // => { '4': 1, '6': 2 } + * _.padLeft('abc', 6, '_-'); + * // => '_-_abc' * - * _.countBy(['one', 'two', 'three'], 'length'); - * // => { '3': 2, '5': 1 } + * _.padLeft('abc', 3); + * // => 'abc' */ - function countBy(collection, callback, thisArg) { - var result = {}; - callback = lodash.createCallback(callback, thisArg); - - forEach(collection, function(value, key, collection) { - key = String(callback(value, key, collection)); - (hasOwnProperty.call(result, key) ? result[key]++ : result[key] = 1); - }); - return result; + function padLeft(string, length, chars) { + string = baseToString(string); + return string && (createPad(string, length, chars) + string); } /** - * Checks if the `callback` returns a truthy value for **all** elements of a - * `collection`. The `callback` is bound to `thisArg` and invoked with three - * arguments; (value, index|key, collection). - * - * If a property name is passed for `callback`, the created "_.pluck" style - * callback will return the property value of the given element. - * - * If an object is passed for `callback`, the created "_.where" style callback - * will return `true` for elements that have the properties of the given object, - * else `false`. + * Pads `string` on the right side if it is shorter then the given padding + * length. The `chars` string may be truncated if the number of padding + * characters exceeds the padding length. * * @static * @memberOf _ - * @alias all - * @category Collections - * @param {Array|Object|String} collection The collection to iterate over. - * @param {Function|Object|String} [callback=identity] The function called per - * iteration. If a property name or object is passed, it will be used to create - * a "_.pluck" or "_.where" style callback, respectively. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Boolean} Returns `true` if all elements pass the callback check, - * else `false`. + * @category String + * @param {string} [string=''] The string to pad. + * @param {number} [length=0] The padding length. + * @param {string} [chars=' '] The string used as padding. + * @returns {string} Returns the padded string. * @example * - * _.every([true, 1, null, 'yes'], Boolean); - * // => false + * _.padRight('abc', 6); + * // => 'abc ' * - * var stooges = [ - * { 'name': 'moe', 'age': 40 }, - * { 'name': 'larry', 'age': 50 } - * ]; + * _.padRight('abc', 6, '_-'); + * // => 'abc_-_' * - * // using "_.pluck" callback shorthand - * _.every(stooges, 'age'); - * // => true - * - * // using "_.where" callback shorthand - * _.every(stooges, { 'age': 50 }); - * // => false + * _.padRight('abc', 3); + * // => 'abc' */ - function every(collection, callback, thisArg) { - var result = true; - callback = lodash.createCallback(callback, thisArg); - - if (isArray(collection)) { - var index = -1, - length = collection.length; - - while (++index < length) { - if (!(result = !!callback(collection[index], index, collection))) { - break; - } - } - } else { - basicEach(collection, function(value, index, collection) { - return (result = !!callback(value, index, collection)); - }); - } - return result; + function padRight(string, length, chars) { + string = baseToString(string); + return string && (string + createPad(string, length, chars)); } /** - * Examines each element in a `collection`, returning an array of all elements - * the `callback` returns truthy for. The `callback` is bound to `thisArg` and - * invoked with three arguments; (value, index|key, collection). + * Converts `string` to an integer of the specified radix. If `radix` is + * `undefined` or `0`, a `radix` of `10` is used unless `value` is a hexadecimal, + * in which case a `radix` of `16` is used. * - * If a property name is passed for `callback`, the created "_.pluck" style - * callback will return the property value of the given element. - * - * If an object is passed for `callback`, the created "_.where" style callback - * will return `true` for elements that have the properties of the given object, - * else `false`. + * **Note:** This method aligns with the ES5 implementation of `parseInt`. + * See the [ES5 spec](https://es5.github.io/#E) for more details. * * @static * @memberOf _ - * @alias select - * @category Collections - * @param {Array|Object|String} collection The collection to iterate over. - * @param {Function|Object|String} [callback=identity] The function called per - * iteration. If a property name or object is passed, it will be used to create - * a "_.pluck" or "_.where" style callback, respectively. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Array} Returns a new array of elements that passed the callback check. + * @category String + * @param {string} string The string to convert. + * @param {number} [radix] The radix to interpret `value` by. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {number} Returns the converted integer. * @example * - * var evens = _.filter([1, 2, 3, 4, 5, 6], function(num) { return num % 2 == 0; }); - * // => [2, 4, 6] - * - * var food = [ - * { 'name': 'apple', 'organic': false, 'type': 'fruit' }, - * { 'name': 'carrot', 'organic': true, 'type': 'vegetable' } - * ]; - * - * // using "_.pluck" callback shorthand - * _.filter(food, 'organic'); - * // => [{ 'name': 'carrot', 'organic': true, 'type': 'vegetable' }] - * - * // using "_.where" callback shorthand - * _.filter(food, { 'type': 'fruit' }); - * // => [{ 'name': 'apple', 'organic': false, 'type': 'fruit' }] - */ - function filter(collection, callback, thisArg) { - var result = []; - callback = lodash.createCallback(callback, thisArg); - - if (isArray(collection)) { - var index = -1, - length = collection.length; - - while (++index < length) { - var value = collection[index]; - if (callback(value, index, collection)) { - result.push(value); - } - } - } else { - basicEach(collection, function(value, index, collection) { - if (callback(value, index, collection)) { - result.push(value); - } - }); - } - return result; - } - - /** - * Examines each element in a `collection`, returning the first that the `callback` - * returns truthy for. The `callback` is bound to `thisArg` and invoked with three - * arguments; (value, index|key, collection). - * - * If a property name is passed for `callback`, the created "_.pluck" style - * callback will return the property value of the given element. - * - * If an object is passed for `callback`, the created "_.where" style callback - * will return `true` for elements that have the properties of the given object, - * else `false`. - * - * @static - * @memberOf _ - * @alias detect, findWhere - * @category Collections - * @param {Array|Object|String} collection The collection to iterate over. - * @param {Function|Object|String} [callback=identity] The function called per - * iteration. If a property name or object is passed, it will be used to create - * a "_.pluck" or "_.where" style callback, respectively. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Mixed} Returns the found element, else `undefined`. - * @example - * - * _.find([1, 2, 3, 4], function(num) { - * return num % 2 == 0; - * }); - * // => 2 - * - * var food = [ - * { 'name': 'apple', 'organic': false, 'type': 'fruit' }, - * { 'name': 'banana', 'organic': true, 'type': 'fruit' }, - * { 'name': 'beet', 'organic': false, 'type': 'vegetable' } - * ]; - * - * // using "_.where" callback shorthand - * _.find(food, { 'type': 'vegetable' }); - * // => { 'name': 'beet', 'organic': false, 'type': 'vegetable' } - * - * // using "_.pluck" callback shorthand - * _.find(food, 'organic'); - * // => { 'name': 'banana', 'organic': true, 'type': 'fruit' } - */ - function find(collection, callback, thisArg) { - callback = lodash.createCallback(callback, thisArg); - - if (isArray(collection)) { - var index = -1, - length = collection.length; - - while (++index < length) { - var value = collection[index]; - if (callback(value, index, collection)) { - return value; - } - } - } else { - var result; - basicEach(collection, function(value, index, collection) { - if (callback(value, index, collection)) { - result = value; - return false; - } - }); - return result; - } - } - - /** - * Iterates over a `collection`, executing the `callback` for each element in - * the `collection`. The `callback` is bound to `thisArg` and invoked with three - * arguments; (value, index|key, collection). Callbacks may exit iteration early - * by explicitly returning `false`. - * - * @static - * @memberOf _ - * @alias each - * @category Collections - * @param {Array|Object|String} collection The collection to iterate over. - * @param {Function} [callback=identity] The function called per iteration. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Array|Object|String} Returns `collection`. - * @example - * - * _([1, 2, 3]).forEach(alert).join(','); - * // => alerts each number and returns '1,2,3' - * - * _.forEach({ 'one': 1, 'two': 2, 'three': 3 }, alert); - * // => alerts each number value (order is not guaranteed) - */ - function forEach(collection, callback, thisArg) { - if (callback && typeof thisArg == 'undefined' && isArray(collection)) { - var index = -1, - length = collection.length; - - while (++index < length) { - if (callback(collection[index], index, collection) === false) { - break; - } - } - } else { - basicEach(collection, callback, thisArg); - } - return collection; - } - - /** - * Creates an object composed of keys returned from running each element of the - * `collection` through the `callback`. The corresponding value of each key is - * an array of elements passed to `callback` that returned the key. The `callback` - * is bound to `thisArg` and invoked with three arguments; (value, index|key, collection). - * - * If a property name is passed for `callback`, the created "_.pluck" style - * callback will return the property value of the given element. - * - * If an object is passed for `callback`, the created "_.where" style callback - * will return `true` for elements that have the properties of the given object, - * else `false` - * - * @static - * @memberOf _ - * @category Collections - * @param {Array|Object|String} collection The collection to iterate over. - * @param {Function|Object|String} [callback=identity] The function called per - * iteration. If a property name or object is passed, it will be used to create - * a "_.pluck" or "_.where" style callback, respectively. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Object} Returns the composed aggregate object. - * @example - * - * _.groupBy([4.2, 6.1, 6.4], function(num) { return Math.floor(num); }); - * // => { '4': [4.2], '6': [6.1, 6.4] } - * - * _.groupBy([4.2, 6.1, 6.4], function(num) { return this.floor(num); }, Math); - * // => { '4': [4.2], '6': [6.1, 6.4] } - * - * // using "_.pluck" callback shorthand - * _.groupBy(['one', 'two', 'three'], 'length'); - * // => { '3': ['one', 'two'], '5': ['three'] } - */ - function groupBy(collection, callback, thisArg) { - var result = {}; - callback = lodash.createCallback(callback, thisArg); - - forEach(collection, function(value, key, collection) { - key = String(callback(value, key, collection)); - (hasOwnProperty.call(result, key) ? result[key] : result[key] = []).push(value); - }); - return result; - } - - /** - * Invokes the method named by `methodName` on each element in the `collection`, - * returning an array of the results of each invoked method. Additional arguments - * will be passed to each invoked method. If `methodName` is a function, it will - * be invoked for, and `this` bound to, each element in the `collection`. - * - * @static - * @memberOf _ - * @category Collections - * @param {Array|Object|String} collection The collection to iterate over. - * @param {Function|String} methodName The name of the method to invoke or - * the function invoked per iteration. - * @param {Mixed} [arg1, arg2, ...] Arguments to invoke the method with. - * @returns {Array} Returns a new array of the results of each invoked method. - * @example - * - * _.invoke([[5, 1, 7], [3, 2, 1]], 'sort'); - * // => [[1, 5, 7], [1, 2, 3]] - * - * _.invoke([123, 456], String.prototype.split, ''); - * // => [['1', '2', '3'], ['4', '5', '6']] - */ - function invoke(collection, methodName) { - var args = nativeSlice.call(arguments, 2), - index = -1, - isFunc = typeof methodName == 'function', - length = collection ? collection.length : 0, - result = Array(typeof length == 'number' ? length : 0); - - forEach(collection, function(value) { - result[++index] = (isFunc ? methodName : value[methodName]).apply(value, args); - }); - return result; - } - - /** - * Creates an array of values by running each element in the `collection` - * through the `callback`. The `callback` is bound to `thisArg` and invoked with - * three arguments; (value, index|key, collection). - * - * If a property name is passed for `callback`, the created "_.pluck" style - * callback will return the property value of the given element. - * - * If an object is passed for `callback`, the created "_.where" style callback - * will return `true` for elements that have the properties of the given object, - * else `false`. - * - * @static - * @memberOf _ - * @alias collect - * @category Collections - * @param {Array|Object|String} collection The collection to iterate over. - * @param {Function|Object|String} [callback=identity] The function called per - * iteration. If a property name or object is passed, it will be used to create - * a "_.pluck" or "_.where" style callback, respectively. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Array} Returns a new array of the results of each `callback` execution. - * @example - * - * _.map([1, 2, 3], function(num) { return num * 3; }); - * // => [3, 6, 9] - * - * _.map({ 'one': 1, 'two': 2, 'three': 3 }, function(num) { return num * 3; }); - * // => [3, 6, 9] (order is not guaranteed) - * - * var stooges = [ - * { 'name': 'moe', 'age': 40 }, - * { 'name': 'larry', 'age': 50 } - * ]; - * - * // using "_.pluck" callback shorthand - * _.map(stooges, 'name'); - * // => ['moe', 'larry'] - */ - function map(collection, callback, thisArg) { - var index = -1, - length = collection ? collection.length : 0, - result = Array(typeof length == 'number' ? length : 0); - - callback = lodash.createCallback(callback, thisArg); - if (isArray(collection)) { - while (++index < length) { - result[index] = callback(collection[index], index, collection); - } - } else { - basicEach(collection, function(value, key, collection) { - result[++index] = callback(value, key, collection); - }); - } - return result; - } - - /** - * Retrieves the maximum value of an `array`. If `callback` is passed, - * it will be executed for each value in the `array` to generate the - * criterion by which the value is ranked. The `callback` is bound to - * `thisArg` and invoked with three arguments; (value, index, collection). - * - * If a property name is passed for `callback`, the created "_.pluck" style - * callback will return the property value of the given element. - * - * If an object is passed for `callback`, the created "_.where" style callback - * will return `true` for elements that have the properties of the given object, - * else `false`. - * - * @static - * @memberOf _ - * @category Collections - * @param {Array|Object|String} collection The collection to iterate over. - * @param {Function|Object|String} [callback=identity] The function called per - * iteration. If a property name or object is passed, it will be used to create - * a "_.pluck" or "_.where" style callback, respectively. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Mixed} Returns the maximum value. - * @example - * - * _.max([4, 2, 8, 6]); + * _.parseInt('08'); * // => 8 * - * var stooges = [ - * { 'name': 'moe', 'age': 40 }, - * { 'name': 'larry', 'age': 50 } - * ]; - * - * _.max(stooges, function(stooge) { return stooge.age; }); - * // => { 'name': 'larry', 'age': 50 }; - * - * // using "_.pluck" callback shorthand - * _.max(stooges, 'age'); - * // => { 'name': 'larry', 'age': 50 }; + * _.map(['6', '08', '10'], _.parseInt); + * // => [6, 8, 10] */ - function max(collection, callback, thisArg) { - var computed = -Infinity, - result = computed; - - if (!callback && isArray(collection)) { - var index = -1, - length = collection.length; - - while (++index < length) { - var value = collection[index]; - if (value > result) { - result = value; - } - } - } else { - callback = (!callback && isString(collection)) - ? charAtCallback - : lodash.createCallback(callback, thisArg); - - basicEach(collection, function(value, index, collection) { - var current = callback(value, index, collection); - if (current > computed) { - computed = current; - result = value; - } - }); + function parseInt(string, radix, guard) { + if (guard && isIterateeCall(string, radix, guard)) { + radix = 0; } + return nativeParseInt(string, radix); + } + // Fallback for environments with pre-ES5 implementations. + if (nativeParseInt(whitespace + '08') != 8) { + parseInt = function(string, radix, guard) { + // Firefox < 21 and Opera < 15 follow ES3 for `parseInt`. + // Chrome fails to trim leading whitespace characters. + // See https://code.google.com/p/v8/issues/detail?id=3109 for more details. + if (guard ? isIterateeCall(string, radix, guard) : radix == null) { + radix = 0; + } else if (radix) { + radix = +radix; + } + string = trim(string); + return nativeParseInt(string, radix || (reHexPrefix.test(string) ? 16 : 10)); + }; + } + + /** + * Repeats the given string `n` times. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to repeat. + * @param {number} [n=0] The number of times to repeat the string. + * @returns {string} Returns the repeated string. + * @example + * + * _.repeat('*', 3); + * // => '***' + * + * _.repeat('abc', 2); + * // => 'abcabc' + * + * _.repeat('abc', 0); + * // => '' + */ + function repeat(string, n) { + var result = ''; + string = baseToString(string); + n = +n; + if (n < 1 || !string || !nativeIsFinite(n)) { + return result; + } + // Leverage the exponentiation by squaring algorithm for a faster repeat. + // See https://en.wikipedia.org/wiki/Exponentiation_by_squaring for more details. + do { + if (n % 2) { + result += string; + } + n = floor(n / 2); + string += string; + } while (n); + return result; } /** - * Retrieves the minimum value of an `array`. If `callback` is passed, - * it will be executed for each value in the `array` to generate the - * criterion by which the value is ranked. The `callback` is bound to `thisArg` - * and invoked with three arguments; (value, index, collection). - * - * If a property name is passed for `callback`, the created "_.pluck" style - * callback will return the property value of the given element. - * - * If an object is passed for `callback`, the created "_.where" style callback - * will return `true` for elements that have the properties of the given object, - * else `false`. + * Converts `string` to snake case. + * See [Wikipedia](https://en.wikipedia.org/wiki/Snake_case) for more details. * * @static * @memberOf _ - * @category Collections - * @param {Array|Object|String} collection The collection to iterate over. - * @param {Function|Object|String} [callback=identity] The function called per - * iteration. If a property name or object is passed, it will be used to create - * a "_.pluck" or "_.where" style callback, respectively. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Mixed} Returns the minimum value. + * @category String + * @param {string} [string=''] The string to convert. + * @returns {string} Returns the snake cased string. * @example * - * _.min([4, 2, 8, 6]); - * // => 2 + * _.snakeCase('Foo Bar'); + * // => 'foo_bar' * - * var stooges = [ - * { 'name': 'moe', 'age': 40 }, - * { 'name': 'larry', 'age': 50 } - * ]; + * _.snakeCase('--foo-bar'); + * // => 'foo_bar' * - * _.min(stooges, function(stooge) { return stooge.age; }); - * // => { 'name': 'moe', 'age': 40 }; - * - * // using "_.pluck" callback shorthand - * _.min(stooges, 'age'); - * // => { 'name': 'moe', 'age': 40 }; + * _.snakeCase('fooBar'); + * // => 'foo_bar' */ - function min(collection, callback, thisArg) { - var computed = Infinity, - result = computed; - - if (!callback && isArray(collection)) { - var index = -1, - length = collection.length; - - while (++index < length) { - var value = collection[index]; - if (value < result) { - result = value; - } - } - } else { - callback = (!callback && isString(collection)) - ? charAtCallback - : lodash.createCallback(callback, thisArg); - - basicEach(collection, function(value, index, collection) { - var current = callback(value, index, collection); - if (current < computed) { - computed = current; - result = value; - } - }); - } - return result; - } + var snakeCase = createCompounder(function(result, word, index) { + return result + (index ? '_' : '') + word.toLowerCase(); + }); /** - * Retrieves the value of a specified property from all elements in the `collection`. + * Checks if `string` starts with the given target string. * * @static * @memberOf _ - * @type Function - * @category Collections - * @param {Array|Object|String} collection The collection to iterate over. - * @param {String} property The property to pluck. - * @returns {Array} Returns a new array of property values. + * @category String + * @param {string} [string=''] The string to search. + * @param {string} [target] The string to search for. + * @param {number} [position=0] The position to search from. + * @returns {boolean} Returns `true` if `string` starts with `target`, else `false`. * @example * - * var stooges = [ - * { 'name': 'moe', 'age': 40 }, - * { 'name': 'larry', 'age': 50 } - * ]; - * - * _.pluck(stooges, 'name'); - * // => ['moe', 'larry'] - */ - 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 passed, the first element of the `collection` will be - * used as the initial `accumulator` value. The `callback` is bound to `thisArg` - * and invoked with four arguments; (accumulator, value, index|key, collection). - * - * @static - * @memberOf _ - * @alias foldl, inject - * @category Collections - * @param {Array|Object|String} collection The collection to iterate over. - * @param {Function} [callback=identity] The function called per iteration. - * @param {Mixed} [accumulator] Initial value of the accumulator. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Mixed} Returns the accumulated value. - * @example - * - * var sum = _.reduce([1, 2, 3], function(sum, num) { - * return sum + num; - * }); - * // => 6 - * - * var mapped = _.reduce({ 'a': 1, 'b': 2, 'c': 3 }, function(result, num, key) { - * result[key] = num * 3; - * return result; - * }, {}); - * // => { 'a': 3, 'b': 6, 'c': 9 } - */ - function reduce(collection, callback, accumulator, thisArg) { - var noaccum = arguments.length < 3; - callback = lodash.createCallback(callback, thisArg, 4); - - if (isArray(collection)) { - var index = -1, - length = collection.length; - - if (noaccum) { - accumulator = collection[++index]; - } - while (++index < length) { - accumulator = callback(accumulator, collection[index], index, collection); - } - } else { - basicEach(collection, function(value, index, collection) { - accumulator = noaccum - ? (noaccum = false, value) - : callback(accumulator, value, index, collection) - }); - } - return accumulator; - } - - /** - * This method is similar to `_.reduce`, except that it iterates over a - * `collection` from right to left. - * - * @static - * @memberOf _ - * @alias foldr - * @category Collections - * @param {Array|Object|String} collection The collection to iterate over. - * @param {Function} [callback=identity] The function called per iteration. - * @param {Mixed} [accumulator] Initial value of the accumulator. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Mixed} Returns the accumulated value. - * @example - * - * var list = [[0, 1], [2, 3], [4, 5]]; - * var flat = _.reduceRight(list, function(a, b) { return a.concat(b); }, []); - * // => [4, 5, 2, 3, 0, 1] - */ - function reduceRight(collection, callback, accumulator, thisArg) { - var iterable = collection, - length = collection ? collection.length : 0, - noaccum = arguments.length < 3; - - if (typeof length != 'number') { - var props = keys(collection); - length = props.length; - } else if (support.unindexedChars && isString(collection)) { - iterable = collection.split(''); - } - callback = lodash.createCallback(callback, thisArg, 4); - forEach(collection, function(value, index, collection) { - index = props ? props[--length] : --length; - accumulator = noaccum - ? (noaccum = false, iterable[index]) - : callback(accumulator, iterable[index], index, collection); - }); - return accumulator; - } - - /** - * The opposite of `_.filter`, this method returns the elements of a - * `collection` that `callback` does **not** return truthy for. - * - * If a property name is passed for `callback`, the created "_.pluck" style - * callback will return the property value of the given element. - * - * If an object is passed for `callback`, the created "_.where" style callback - * will return `true` for elements that have the properties of the given object, - * else `false`. - * - * @static - * @memberOf _ - * @category Collections - * @param {Array|Object|String} collection The collection to iterate over. - * @param {Function|Object|String} [callback=identity] The function called per - * iteration. If a property name or object is passed, it will be used to create - * a "_.pluck" or "_.where" style callback, respectively. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Array} Returns a new array of elements that did **not** pass the - * callback check. - * @example - * - * var odds = _.reject([1, 2, 3, 4, 5, 6], function(num) { return num % 2 == 0; }); - * // => [1, 3, 5] - * - * var food = [ - * { 'name': 'apple', 'organic': false, 'type': 'fruit' }, - * { 'name': 'carrot', 'organic': true, 'type': 'vegetable' } - * ]; - * - * // using "_.pluck" callback shorthand - * _.reject(food, 'organic'); - * // => [{ 'name': 'apple', 'organic': false, 'type': 'fruit' }] - * - * // using "_.where" callback shorthand - * _.reject(food, { 'type': 'fruit' }); - * // => [{ 'name': 'carrot', 'organic': true, 'type': 'vegetable' }] - */ - function reject(collection, callback, thisArg) { - callback = lodash.createCallback(callback, thisArg); - return filter(collection, function(value, index, collection) { - return !callback(value, index, collection); - }); - } - - /** - * Creates an array of shuffled `array` values, using a version of the - * Fisher-Yates shuffle. See http://en.wikipedia.org/wiki/Fisher-Yates_shuffle. - * - * @static - * @memberOf _ - * @category Collections - * @param {Array|Object|String} collection The collection to shuffle. - * @returns {Array} Returns a new shuffled collection. - * @example - * - * _.shuffle([1, 2, 3, 4, 5, 6]); - * // => [4, 1, 6, 3, 5, 2] - */ - function shuffle(collection) { - var index = -1, - length = collection ? collection.length : 0, - result = Array(typeof length == 'number' ? length : 0); - - forEach(collection, function(value) { - var rand = floor(nativeRandom() * (++index + 1)); - result[index] = result[rand]; - result[rand] = value; - }); - return result; - } - - /** - * Gets the size of the `collection` by returning `collection.length` for arrays - * and array-like objects or the number of own enumerable properties for objects. - * - * @static - * @memberOf _ - * @category Collections - * @param {Array|Object|String} collection The collection to inspect. - * @returns {Number} Returns `collection.length` or number of own enumerable properties. - * @example - * - * _.size([1, 2]); - * // => 2 - * - * _.size({ 'one': 1, 'two': 2, 'three': 3 }); - * // => 3 - * - * _.size('curly'); - * // => 5 - */ - function size(collection) { - var length = collection ? collection.length : 0; - return typeof length == 'number' ? length : keys(collection).length; - } - - /** - * Checks if the `callback` returns a truthy value for **any** element of a - * `collection`. The function returns as soon as it finds passing value, and - * does not iterate over the entire `collection`. The `callback` is bound to - * `thisArg` and invoked with three arguments; (value, index|key, collection). - * - * If a property name is passed for `callback`, the created "_.pluck" style - * callback will return the property value of the given element. - * - * If an object is passed for `callback`, the created "_.where" style callback - * will return `true` for elements that have the properties of the given object, - * else `false`. - * - * @static - * @memberOf _ - * @alias any - * @category Collections - * @param {Array|Object|String} collection The collection to iterate over. - * @param {Function|Object|String} [callback=identity] The function called per - * iteration. If a property name or object is passed, it will be used to create - * a "_.pluck" or "_.where" style callback, respectively. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Boolean} Returns `true` if any element passes the callback check, - * else `false`. - * @example - * - * _.some([null, 0, 'yes', false], Boolean); + * _.startsWith('abc', 'a'); * // => true * - * var food = [ - * { 'name': 'apple', 'organic': false, 'type': 'fruit' }, - * { 'name': 'carrot', 'organic': true, 'type': 'vegetable' } - * ]; - * - * // using "_.pluck" callback shorthand - * _.some(food, 'organic'); - * // => true - * - * // using "_.where" callback shorthand - * _.some(food, { 'type': 'meat' }); + * _.startsWith('abc', 'b'); * // => false + * + * _.startsWith('abc', 'b', 1); + * // => true */ - function some(collection, callback, thisArg) { - var result; - callback = lodash.createCallback(callback, thisArg); - - if (isArray(collection)) { - var index = -1, - length = collection.length; - - while (++index < length) { - if ((result = callback(collection[index], index, collection))) { - break; - } - } - } else { - basicEach(collection, function(value, index, collection) { - return !(result = callback(value, index, collection)); - }); - } - return !!result; + function startsWith(string, target, position) { + string = baseToString(string); + position = position == null ? 0 : nativeMin(position < 0 ? 0 : (+position || 0), string.length); + return string.lastIndexOf(target, position) == position; } /** - * Creates an array of elements, sorted in ascending order by the results of - * running each element in the `collection` through the `callback`. This method - * performs a stable sort, that is, it will preserve the original sort order of - * equal elements. The `callback` is bound to `thisArg` and invoked with three - * arguments; (value, index|key, collection). + * Creates a compiled template function that can interpolate data properties + * in "interpolate" delimiters, HTML-escape interpolated data properties in + * "escape" delimiters, and execute JavaScript in "evaluate" delimiters. Data + * properties may be accessed as free variables in the template. If a setting + * object is provided it takes precedence over `_.templateSettings` values. * - * If a property name is passed for `callback`, the created "_.pluck" style - * callback will return the property value of the given element. + * **Note:** In the development build `_.template` utilizes sourceURLs for easier debugging. + * See the [HTML5 Rocks article on sourcemaps](http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl) + * for more details. * - * If an object is passed for `callback`, the created "_.where" style callback - * will return `true` for elements that have the properties of the given object, - * else `false`. + * For more information on precompiling templates see + * [lodash's custom builds documentation](https://lodash.com/custom-builds). + * + * For more information on Chrome extension sandboxes see + * [Chrome's extensions documentation](https://developer.chrome.com/extensions/sandboxingEval). * * @static * @memberOf _ - * @category Collections - * @param {Array|Object|String} collection The collection to iterate over. - * @param {Function|Object|String} [callback=identity] The function called per - * iteration. If a property name or object is passed, it will be used to create - * a "_.pluck" or "_.where" style callback, respectively. - * @param {Mixed} [thisArg] The `this` binding of `callback`. - * @returns {Array} Returns a new array of sorted elements. + * @category String + * @param {string} [string=''] The template string. + * @param {Object} [options] The options object. + * @param {RegExp} [options.escape] The HTML "escape" delimiter. + * @param {RegExp} [options.evaluate] The "evaluate" delimiter. + * @param {Object} [options.imports] An object to import into the template as free variables. + * @param {RegExp} [options.interpolate] The "interpolate" delimiter. + * @param {string} [options.sourceURL] The sourceURL of the template's compiled source. + * @param {string} [options.variable] The data object variable name. + * @param- {Object} [otherOptions] Enables the legacy `options` param signature. + * @returns {Function} Returns the compiled template function. * @example * - * _.sortBy([1, 2, 3], function(num) { return Math.sin(num); }); - * // => [3, 1, 2] + * // using the "interpolate" delimiter to create a compiled template + * var compiled = _.template('hello <%= user %>!'); + * compiled({ 'user': 'fred' }); + * // => 'hello fred!' * - * _.sortBy([1, 2, 3], function(num) { return this.sin(num); }, Math); - * // => [3, 1, 2] + * // using the HTML "escape" delimiter to escape data property values + * var compiled = _.template('<%- value %>'); + * compiled({ 'value': '