diff --git a/Gruntfile.js b/Gruntfile.js index 811c16cc89..c732eafd7d 100644 --- a/Gruntfile.js +++ b/Gruntfile.js @@ -6,7 +6,7 @@ var path = require('path'), when = require('when'), semver = require('semver'), fs = require('fs'), - _ = require('underscore'), + _ = require('lodash'), spawn = require('child_process').spawn, buildDirectory = path.resolve(process.cwd(), '.build'), distDirectory = path.resolve(process.cwd(), '.dist'), @@ -380,7 +380,7 @@ var path = require('path'), 'core/shared/vendor/jquery/jquery-ui-1.10.3.custom.min.js', 'core/client/assets/lib/jquery-utils.js', 'core/client/assets/lib/uploader.js', - 'core/shared/vendor/underscore.js', + 'core/shared/vendor/lodash.underscore.js', 'core/shared/vendor/backbone/backbone.js', 'core/shared/vendor/handlebars/handlebars-runtime.js', 'core/shared/vendor/moment.js', @@ -435,7 +435,7 @@ var path = require('path'), 'core/shared/vendor/jquery/jquery-ui-1.10.3.custom.min.js', 'core/client/assets/lib/jquery-utils.js', 'core/client/assets/lib/uploader.js', - 'core/shared/vendor/underscore.js', + 'core/shared/vendor/lodash.underscore.js', 'core/shared/vendor/backbone/backbone.js', 'core/shared/vendor/handlebars/handlebars-runtime.js', 'core/shared/vendor/moment.js', diff --git a/core/server/api/db.js b/core/server/api/db.js index 4c0e24d4e8..a29c16e490 100644 --- a/core/server/api/db.js +++ b/core/server/api/db.js @@ -5,7 +5,7 @@ var dataExport = require('../data/export'), path = require('path'), when = require('when'), nodefn = require('when/node/function'), - _ = require('underscore'), + _ = require('lodash'), schema = require('../data/schema').tables, configPaths = require('../config/paths'), api = {}, diff --git a/core/server/api/index.js b/core/server/api/index.js index f80f6b1bd1..249274f46f 100644 --- a/core/server/api/index.js +++ b/core/server/api/index.js @@ -1,7 +1,7 @@ // # Ghost Data API // Provides access to the data model -var _ = require('underscore'), +var _ = require('lodash'), when = require('when'), config = require('../config'), errors = require('../errorHandling'), diff --git a/core/server/api/notifications.js b/core/server/api/notifications.js index 1a454a27e3..d2a5347844 100644 --- a/core/server/api/notifications.js +++ b/core/server/api/notifications.js @@ -1,5 +1,5 @@ var when = require('when'), - _ = require('underscore'), + _ = require('lodash'), // Holds the persistent notifications notificationsStore = [], notifications; diff --git a/core/server/api/posts.js b/core/server/api/posts.js index 9879d8118a..b4be27853d 100644 --- a/core/server/api/posts.js +++ b/core/server/api/posts.js @@ -1,5 +1,5 @@ var when = require('when'), - _ = require('underscore'), + _ = require('lodash'), dataProvider = require('../models'), permissions = require('../permissions'), canThis = permissions.canThis, diff --git a/core/server/api/settings.js b/core/server/api/settings.js index 70404cf1e7..4283f82fc5 100644 --- a/core/server/api/settings.js +++ b/core/server/api/settings.js @@ -1,4 +1,4 @@ -var _ = require('underscore'), +var _ = require('lodash'), dataProvider = require('../models'), when = require('when'), errors = require('../errorHandling'), diff --git a/core/server/api/users.js b/core/server/api/users.js index e150aafc57..1ed3c095da 100644 --- a/core/server/api/users.js +++ b/core/server/api/users.js @@ -1,5 +1,5 @@ var when = require('when'), - _ = require('underscore'), + _ = require('lodash'), dataProvider = require('../models'), settings = require('./settings'), ONE_DAY = 86400000, diff --git a/core/server/apps/index.js b/core/server/apps/index.js index 911384d704..bef76cbf9f 100644 --- a/core/server/apps/index.js +++ b/core/server/apps/index.js @@ -1,5 +1,5 @@ -var _ = require('underscore'), +var _ = require('lodash'), when = require('when'), errors = require('../errorHandling'), api = require('../api'), diff --git a/core/server/apps/loader.js b/core/server/apps/loader.js index 73a1d37edc..0573a7fada 100644 --- a/core/server/apps/loader.js +++ b/core/server/apps/loader.js @@ -1,6 +1,6 @@ var path = require('path'), - _ = require('underscore'), + _ = require('lodash'), when = require('when'), appProxy = require('./proxy'), config = require('../config'), diff --git a/core/server/apps/proxy.js b/core/server/apps/proxy.js index b159ec503b..922abc4710 100644 --- a/core/server/apps/proxy.js +++ b/core/server/apps/proxy.js @@ -1,4 +1,4 @@ -var _ = require('underscore'), +var _ = require('lodash'), api = require('../api'), helpers = require('../helpers'), filters = require('../filters'); diff --git a/core/server/apps/sandbox.js b/core/server/apps/sandbox.js index 418444dfc8..dc08bea55d 100644 --- a/core/server/apps/sandbox.js +++ b/core/server/apps/sandbox.js @@ -1,8 +1,8 @@ -var fs = require('fs'), - path = require('path'), - Module = require('module'), - _ = require('underscore'); +var fs = require('fs'), + path = require('path'), + Module = require('module'), + _ = require('lodash'); function AppSandbox(opts) { this.opts = _.defaults(opts || {}, AppSandbox.defaults); diff --git a/core/server/config/paths.js b/core/server/config/paths.js index 0fa51f179f..a1c8f944d5 100644 --- a/core/server/config/paths.js +++ b/core/server/config/paths.js @@ -5,7 +5,7 @@ var moment = require('moment'), path = require('path'), when = require('when'), url = require('url'), - _ = require('underscore'), + _ = require('lodash'), requireTree = require('../require-tree'), appRoot = path.resolve(__dirname, '../../../'), corePath = path.resolve(appRoot, 'core/'), diff --git a/core/server/controllers/admin.js b/core/server/controllers/admin.js index c06a7d6efc..641072400f 100644 --- a/core/server/controllers/admin.js +++ b/core/server/controllers/admin.js @@ -1,5 +1,5 @@ var config = require('../config'), - _ = require('underscore'), + _ = require('lodash'), path = require('path'), when = require('when'), api = require('../api'), diff --git a/core/server/controllers/frontend.js b/core/server/controllers/frontend.js index ee288337a0..2ea395ce4f 100644 --- a/core/server/controllers/frontend.js +++ b/core/server/controllers/frontend.js @@ -6,7 +6,7 @@ var moment = require('moment'), RSS = require('rss'), - _ = require('underscore'), + _ = require('lodash'), url = require('url'), when = require('when'), diff --git a/core/server/data/export/index.js b/core/server/data/export/index.js index 9a28634031..0c974c9af8 100644 --- a/core/server/data/export/index.js +++ b/core/server/data/export/index.js @@ -1,5 +1,5 @@ var when = require('when'), - _ = require('underscore'), + _ = require('lodash'), migration = require('../migration'), knex = require('../../models/base').knex, schema = require('../schema').tables, diff --git a/core/server/data/fixtures/index.js b/core/server/data/fixtures/index.js index 8b7b1ad738..902538f8ea 100644 --- a/core/server/data/fixtures/index.js +++ b/core/server/data/fixtures/index.js @@ -1,5 +1,5 @@ var sequence = require('when/sequence'), - _ = require('underscore'), + _ = require('lodash'), Post = require('../../models/post').Post, Tag = require('../../models/tag').Tag, Role = require('../../models/role').Role, diff --git a/core/server/data/import/000.js b/core/server/data/import/000.js index 9f134e0e3d..5346454f15 100644 --- a/core/server/data/import/000.js +++ b/core/server/data/import/000.js @@ -1,5 +1,5 @@ var when = require('when'), - _ = require('underscore'), + _ = require('lodash'), models = require('../../models'), errors = require('../../errorHandling'), Importer000; diff --git a/core/server/data/migration/index.js b/core/server/data/migration/index.js index 60260191f4..078567f2a0 100644 --- a/core/server/data/migration/index.js +++ b/core/server/data/migration/index.js @@ -1,4 +1,4 @@ -var _ = require('underscore'), +var _ = require('lodash'), when = require('when'), errors = require('../../errorHandling'), client = require('../../models/base').client, diff --git a/core/server/errorHandling.js b/core/server/errorHandling.js index 54b423e1b9..4ba7d7d413 100644 --- a/core/server/errorHandling.js +++ b/core/server/errorHandling.js @@ -1,5 +1,5 @@ /*jslint regexp: true */ -var _ = require('underscore'), +var _ = require('lodash'), colors = require('colors'), fs = require('fs'), configPaths = require('./config/paths'), @@ -227,16 +227,16 @@ errors = { } }; -// Ensure our 'this' context in the functions -_.bindAll( - errors, - 'throwError', - 'logError', +// Ensure our 'this' context for methods and preserve method arity by +// using Function#bind for expressjs +_.each([ 'logAndThrowError', 'logErrorWithRedirect', 'renderErrorPage', 'error404', 'error500' -); +], function (funcName) { + errors[funcName] = errors[funcName].bind(errors); +}); module.exports = errors; diff --git a/core/server/filters.js b/core/server/filters.js index 523e4d572f..d7aad1fa6f 100644 --- a/core/server/filters.js +++ b/core/server/filters.js @@ -1,5 +1,5 @@ var when = require('when'), - _ = require('underscore'), + _ = require('lodash'), defaults; diff --git a/core/server/helpers/index.js b/core/server/helpers/index.js index 97766e380a..3f7e6a2b2f 100644 --- a/core/server/helpers/index.js +++ b/core/server/helpers/index.js @@ -3,7 +3,7 @@ var downsize = require('downsize'), moment = require('moment'), path = require('path'), polyglot = require('node-polyglot').instance, - _ = require('underscore'), + _ = require('lodash'), when = require('when'), api = require('../api'), diff --git a/core/server/index.js b/core/server/index.js index a71fbd7034..4fd4250b01 100644 --- a/core/server/index.js +++ b/core/server/index.js @@ -7,7 +7,7 @@ var crypto = require('crypto'), path = require('path'), Polyglot = require('node-polyglot'), semver = require('semver'), - _ = require('underscore'), + _ = require('lodash'), when = require('when'), api = require('./api'), diff --git a/core/server/mail.js b/core/server/mail.js index 060a2d683b..366fb3e6c9 100644 --- a/core/server/mail.js +++ b/core/server/mail.js @@ -1,6 +1,6 @@ var cp = require('child_process'), url = require('url'), - _ = require('underscore'), + _ = require('lodash'), when = require('when'), nodefn = require('when/node/function'), nodemailer = require('nodemailer'), diff --git a/core/server/middleware/index.js b/core/server/middleware/index.js index 40a4eaf9a5..94ad640f16 100644 --- a/core/server/middleware/index.js +++ b/core/server/middleware/index.js @@ -4,7 +4,7 @@ var middleware = require('./middleware'), express = require('express'), - _ = require('underscore'), + _ = require('lodash'), url = require('url'), when = require('when'), slashes = require('connect-slashes'), diff --git a/core/server/middleware/middleware.js b/core/server/middleware/middleware.js index ca05bfbe7a..797027173c 100644 --- a/core/server/middleware/middleware.js +++ b/core/server/middleware/middleware.js @@ -2,7 +2,7 @@ // The following custom middleware functions are all unit testable, and have accompanying unit tests in // middleware_spec.js -var _ = require('underscore'), +var _ = require('lodash'), express = require('express'), busboy = require('./ghost-busboy'), config = require('../config'), diff --git a/core/server/models/base.js b/core/server/models/base.js index 3fd003a010..f306635efc 100644 --- a/core/server/models/base.js +++ b/core/server/models/base.js @@ -2,7 +2,7 @@ var ghostBookshelf, Bookshelf = require('bookshelf'), when = require('when'), moment = require('moment'), - _ = require('underscore'), + _ = require('lodash'), uuid = require('node-uuid'), config = require('../config'), Validator = require('validator').Validator, diff --git a/core/server/models/index.js b/core/server/models/index.js index f5f1eefc45..f0b764d8c5 100644 --- a/core/server/models/index.js +++ b/core/server/models/index.js @@ -1,5 +1,5 @@ var migrations = require('../data/migration'), - _ = require('underscore'); + _ = require('lodash'); module.exports = { Post: require('./post').Post, diff --git a/core/server/models/post.js b/core/server/models/post.js index d525cfd9b6..e19a9995ea 100644 --- a/core/server/models/post.js +++ b/core/server/models/post.js @@ -1,6 +1,6 @@ var Post, Posts, - _ = require('underscore'), + _ = require('lodash'), uuid = require('node-uuid'), when = require('when'), errors = require('../errorHandling'), diff --git a/core/server/models/settings.js b/core/server/models/settings.js index 8c0e89f230..fb5cc70a71 100644 --- a/core/server/models/settings.js +++ b/core/server/models/settings.js @@ -2,7 +2,7 @@ var Settings, ghostBookshelf = require('./base'), validator = ghostBookshelf.validator, uuid = require('node-uuid'), - _ = require('underscore'), + _ = require('lodash'), errors = require('../errorHandling'), when = require('when'), defaultSettings; diff --git a/core/server/models/user.js b/core/server/models/user.js index f19ea25156..9b66d91bb8 100644 --- a/core/server/models/user.js +++ b/core/server/models/user.js @@ -1,6 +1,6 @@ var User, Users, - _ = require('underscore'), + _ = require('lodash'), uuid = require('node-uuid'), when = require('when'), errors = require('../errorHandling'), diff --git a/core/server/permissions/index.js b/core/server/permissions/index.js index 02f9015f5f..61bee87483 100644 --- a/core/server/permissions/index.js +++ b/core/server/permissions/index.js @@ -1,7 +1,7 @@ // canThis(someUser).edit.posts([id]|[[ids]]) // canThis(someUser).edit.post(somePost|somePostId) -var _ = require('underscore'), +var _ = require('lodash'), when = require('when'), Models = require('../models'), objectTypeModelMap = require('./objectTypeModelMap'), diff --git a/core/server/storage/base.js b/core/server/storage/base.js index 8961679371..fb344d60cc 100644 --- a/core/server/storage/base.js +++ b/core/server/storage/base.js @@ -1,4 +1,4 @@ -var _ = require('underscore'), +var _ = require('lodash'), moment = require('moment'), path = require('path'), when = require('when'), diff --git a/core/server/storage/localfilesystem.js b/core/server/storage/localfilesystem.js index aef04bf2b4..238369f8de 100644 --- a/core/server/storage/localfilesystem.js +++ b/core/server/storage/localfilesystem.js @@ -1,7 +1,7 @@ // # Local File System Image Storage module // The (default) module for storing images, using the local file system -var _ = require('underscore'), +var _ = require('lodash'), express = require('express'), fs = require('fs-extra'), nodefn = require('when/node/function'), diff --git a/core/server/update-check.js b/core/server/update-check.js index 608167032a..13c3c4a5b3 100644 --- a/core/server/update-check.js +++ b/core/server/update-check.js @@ -25,7 +25,7 @@ var crypto = require('crypto'), semver = require('semver'), when = require('when'), nodefn = require('when/node/function'), - _ = require('underscore'), + _ = require('lodash'), url = require('url'), api = require('./api'), diff --git a/core/shared/vendor/lodash.underscore.js b/core/shared/vendor/lodash.underscore.js new file mode 100644 index 0000000000..0c84471f5d --- /dev/null +++ b/core/shared/vendor/lodash.underscore.js @@ -0,0 +1,4979 @@ +/** + * @license + * Lo-Dash 2.4.1 (Custom Build) + * Build: `lodash underscore exports="amd,commonjs,global,node" -o ./dist/lodash.underscore.js` + * Copyright 2012-2013 The Dojo Foundation + * Based on Underscore.js 1.5.2 + * Copyright 2009-2013 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors + * Available under MIT license + */ +;(function() { + + /** Used as a safe reference for `undefined` in pre ES5 environments */ + var undefined; + + /** Used to generate unique IDs */ + var idCounter = 0; + + /** Used internally to indicate various things */ + var indicatorObject = {}; + + /** Used to prefix keys to avoid issues with `__proto__` and properties on `Object.prototype` */ + var keyPrefix = +new Date + ''; + + /** Used to match "interpolate" template delimiters */ + var reInterpolate = /<%=([\s\S]+?)%>/g; + + /** Used to ensure capturing order of template delimiters */ + var reNoMatch = /($^)/; + + /** Used to match unescaped characters in compiled string literals */ + var reUnescapedString = /['\n\r\t\u2028\u2029\\]/g; + + /** `Object#toString` result shortcuts */ + var argsClass = '[object Arguments]', + arrayClass = '[object Array]', + boolClass = '[object Boolean]', + dateClass = '[object Date]', + funcClass = '[object Function]', + numberClass = '[object Number]', + objectClass = '[object Object]', + regexpClass = '[object RegExp]', + stringClass = '[object String]'; + + /** Used to determine if values are of the language type Object */ + var objectTypes = { + 'boolean': false, + 'function': true, + 'object': true, + 'number': false, + 'string': false, + 'undefined': false + }; + + /** Used to escape characters for inclusion in compiled string literals */ + var stringEscapes = { + '\\': '\\', + "'": "'", + '\n': 'n', + '\r': 'r', + '\t': 't', + '\u2028': 'u2028', + '\u2029': 'u2029' + }; + + /** Used as a reference to the global object */ + var root = (objectTypes[typeof window] && window) || this; + + /** Detect free variable `exports` */ + var freeExports = objectTypes[typeof exports] && exports && !exports.nodeType && exports; + + /** Detect free variable `module` */ + var freeModule = objectTypes[typeof module] && module && !module.nodeType && module; + + /** Detect the popular CommonJS extension `module.exports` */ + var moduleExports = freeModule && freeModule.exports === freeExports && freeExports; + + /** Detect free variable `global` from Node.js or Browserified code and use it as `root` */ + var freeGlobal = objectTypes[typeof global] && global; + if (freeGlobal && (freeGlobal.global === freeGlobal || freeGlobal.window === freeGlobal)) { + root = freeGlobal; + } + + /*--------------------------------------------------------------------------*/ + + /** + * The base implementation of `_.indexOf` without support for binary searches + * or `fromIndex` constraints. + * + * @private + * @param {Array} array The array to search. + * @param {*} value The value to search for. + * @param {number} [fromIndex=0] The index to search from. + * @returns {number} Returns the index of the matched value or `-1`. + */ + function baseIndexOf(array, value, fromIndex) { + var index = (fromIndex || 0) - 1, + length = array ? array.length : 0; + + while (++index < length) { + if (array[index] === value) { + return index; + } + } + return -1; + } + + /** + * Used by `sortBy` to compare transformed `collection` elements, stable sorting + * them in ascending order. + * + * @private + * @param {Object} a The object to compare to `b`. + * @param {Object} b The object to compare to `a`. + * @returns {number} Returns the sort order indicator of `1` or `-1`. + */ + function compareAscending(a, b) { + var ac = a.criteria, + bc = b.criteria, + index = -1, + length = ac.length; + + while (++index < length) { + var value = ac[index], + other = bc[index]; + + if (value !== other) { + if (value > other || typeof value == 'undefined') { + return 1; + } + if (value < other || typeof other == 'undefined') { + return -1; + } + } + } + // Fixes an `Array#sort` bug in the JS engine embedded in Adobe applications + // that causes it, under certain circumstances, to return the same value for + // `a` and `b`. See https://github.com/jashkenas/underscore/pull/1247 + // + // This also ensures a stable sort in V8 and other engines. + // See http://code.google.com/p/v8/issues/detail?id=90 + return a.index - b.index; + } + + /** + * Used by `template` to escape characters for inclusion in compiled + * string literals. + * + * @private + * @param {string} match The matched character to escape. + * @returns {string} Returns the escaped character. + */ + function escapeStringChar(match) { + return '\\' + stringEscapes[match]; + } + + /** + * Slices the `collection` from the `start` index up to, but not including, + * the `end` index. + * + * Note: This function is used instead of `Array#slice` to support node lists + * in IE < 9 and to ensure dense arrays are returned. + * + * @private + * @param {Array|Object|string} collection The collection to slice. + * @param {number} start The start index. + * @param {number} end The end index. + * @returns {Array} Returns the new array. + */ + function slice(array, start, end) { + start || (start = 0); + if (typeof end == 'undefined') { + end = array ? array.length : 0; + } + var index = -1, + length = end - start || 0, + result = Array(length < 0 ? 0 : length); + + while (++index < length) { + result[index] = array[start + index]; + } + return result; + } + + /*--------------------------------------------------------------------------*/ + + /** + * Used for `Array` method references. + * + * Normally `Array.prototype` would suffice, however, using an array literal + * avoids issues in Narwhal. + */ + var arrayRef = []; + + /** Used for native method references */ + var objectProto = Object.prototype; + + /** Used to restore the original `_` reference in `noConflict` */ + var oldDash = root._; + + /** Used to resolve the internal [[Class]] of values */ + var toString = objectProto.toString; + + /** Used to detect if a method is native */ + var reNative = RegExp('^' + + String(toString) + .replace(/[.*+?^${}()|[\]\\]/g, '\\$&') + .replace(/toString| for [^\]]+/g, '.*?') + '$' + ); + + /** Native method shortcuts */ + var ceil = Math.ceil, + floor = Math.floor, + hasOwnProperty = objectProto.hasOwnProperty, + push = arrayRef.push, + propertyIsEnumerable = objectProto.propertyIsEnumerable; + + /* Native method shortcuts for methods with the same name as other `lodash` methods */ + var nativeCreate = isNative(nativeCreate = Object.create) && nativeCreate, + nativeIsArray = isNative(nativeIsArray = Array.isArray) && nativeIsArray, + nativeIsFinite = root.isFinite, + nativeIsNaN = root.isNaN, + nativeKeys = isNative(nativeKeys = Object.keys) && nativeKeys, + nativeMax = Math.max, + nativeMin = Math.min, + nativeRandom = Math.random; + + /*--------------------------------------------------------------------------*/ + + /** + * Creates a `lodash` object which wraps the given value to enable intuitive + * method chaining. + * + * In addition to Lo-Dash methods, wrappers also have the following `Array` methods: + * `concat`, `join`, `pop`, `push`, `reverse`, `shift`, `slice`, `sort`, `splice`, + * and `unshift` + * + * Chaining is supported in custom builds as long as the `value` method is + * implicitly or explicitly included in the build. + * + * The chainable wrapper functions are: + * `after`, `assign`, `bind`, `bindAll`, `bindKey`, `chain`, `compact`, + * `compose`, `concat`, `countBy`, `create`, `createCallback`, `curry`, + * `debounce`, `defaults`, `defer`, `delay`, `difference`, `filter`, `flatten`, + * `forEach`, `forEachRight`, `forIn`, `forInRight`, `forOwn`, `forOwnRight`, + * `functions`, `groupBy`, `indexBy`, `initial`, `intersection`, `invert`, + * `invoke`, `keys`, `map`, `max`, `memoize`, `merge`, `min`, `object`, `omit`, + * `once`, `pairs`, `partial`, `partialRight`, `pick`, `pluck`, `pull`, `push`, + * `range`, `reject`, `remove`, `rest`, `reverse`, `shuffle`, `slice`, `sort`, + * `sortBy`, `splice`, `tap`, `throttle`, `times`, `toArray`, `transform`, + * `union`, `uniq`, `unshift`, `unzip`, `values`, `where`, `without`, `wrap`, + * and `zip` + * + * The non-chainable wrapper functions are: + * `clone`, `cloneDeep`, `contains`, `escape`, `every`, `find`, `findIndex`, + * `findKey`, `findLast`, `findLastIndex`, `findLastKey`, `has`, `identity`, + * `indexOf`, `isArguments`, `isArray`, `isBoolean`, `isDate`, `isElement`, + * `isEmpty`, `isEqual`, `isFinite`, `isFunction`, `isNaN`, `isNull`, `isNumber`, + * `isObject`, `isPlainObject`, `isRegExp`, `isString`, `isUndefined`, `join`, + * `lastIndexOf`, `mixin`, `noConflict`, `parseInt`, `pop`, `random`, `reduce`, + * `reduceRight`, `result`, `shift`, `size`, `some`, `sortedIndex`, `runInContext`, + * `template`, `unescape`, `uniqueId`, and `value` + * + * The wrapper functions `first` and `last` return wrapped values when `n` is + * provided, otherwise they return unwrapped values. + * + * Explicit chaining can be enabled by using the `_.chain` method. + * + * @name _ + * @constructor + * @category Chaining + * @param {*} value The value to wrap in a `lodash` instance. + * @returns {Object} Returns a `lodash` instance. + * @example + * + * var wrapped = _([1, 2, 3]); + * + * // returns an unwrapped value + * wrapped.reduce(function(sum, num) { + * return sum + num; + * }); + * // => 6 + * + * // returns a wrapped value + * var squares = wrapped.map(function(num) { + * return num * num; + * }); + * + * _.isArray(squares); + * // => false + * + * _.isArray(squares.value()); + * // => true + */ + function lodash(value) { + return (value instanceof lodash) + ? value + : new lodashWrapper(value); + } + + /** + * A fast path for creating `lodash` wrapper objects. + * + * @private + * @param {*} value The value to wrap in a `lodash` instance. + * @param {boolean} chainAll A flag to enable chaining for all methods + * @returns {Object} Returns a `lodash` instance. + */ + function lodashWrapper(value, chainAll) { + this.__chain__ = !!chainAll; + this.__wrapped__ = value; + } + // ensure `new lodashWrapper` is an instance of `lodash` + lodashWrapper.prototype = lodash.prototype; + + /** + * An object used to flag environments features. + * + * @static + * @memberOf _ + * @type Object + */ + var support = {}; + + (function() { + var object = { '0': 1, 'length': 1 }; + + /** + * Detect if `Array#shift` and `Array#splice` augment array-like objects correctly. + * + * Firefox < 10, IE compatibility mode, and IE < 9 have buggy Array `shift()` + * and `splice()` functions that fail to remove the last element, `value[0]`, + * of array-like objects even though the `length` property is set to `0`. + * The `shift()` method is buggy in IE 8 compatibility mode, while `splice()` + * is buggy regardless of mode in IE < 9 and buggy in compatibility mode in IE 9. + * + * @memberOf _.support + * @type boolean + */ + support.spliceObjects = (arrayRef.splice.call(object, 0, 1), !object[0]); + }(1)); + + /** + * By default, the template delimiters used by Lo-Dash are similar to those in + * embedded Ruby (ERB). Change the following template settings to use alternative + * delimiters. + * + * @static + * @memberOf _ + * @type Object + */ + lodash.templateSettings = { + + /** + * Used to detect `data` property values to be HTML-escaped. + * + * @memberOf _.templateSettings + * @type RegExp + */ + 'escape': /<%-([\s\S]+?)%>/g, + + /** + * Used to detect code to be evaluated. + * + * @memberOf _.templateSettings + * @type RegExp + */ + 'evaluate': /<%([\s\S]+?)%>/g, + + /** + * Used to detect `data` property values to inject. + * + * @memberOf _.templateSettings + * @type RegExp + */ + 'interpolate': reInterpolate, + + /** + * Used to reference the data object in the template text. + * + * @memberOf _.templateSettings + * @type string + */ + 'variable': '' + }; + + /*--------------------------------------------------------------------------*/ + + /** + * The base implementation of `_.bind` that creates the bound function and + * sets its meta data. + * + * @private + * @param {Array} bindData The bind data array. + * @returns {Function} Returns the new bound function. + */ + function baseBind(bindData) { + var func = bindData[0], + partialArgs = bindData[2], + thisArg = bindData[4]; + + function bound() { + // `Function#bind` spec + // http://es5.github.io/#x15.3.4.5 + if (partialArgs) { + // avoid `arguments` object deoptimizations by using `slice` instead + // of `Array.prototype.slice.call` and not assigning `arguments` to a + // variable as a ternary expression + var args = slice(partialArgs); + push.apply(args, arguments); + } + // mimic the constructor's `return` behavior + // http://es5.github.io/#x13.2.2 + if (this instanceof bound) { + // ensure `new bound` is an instance of `func` + var thisBinding = baseCreate(func.prototype), + result = func.apply(thisBinding, args || arguments); + return isObject(result) ? result : thisBinding; + } + return func.apply(thisArg, args || arguments); + } + return bound; + } + + /** + * The base implementation of `_.create` without support for assigning + * properties to the created object. + * + * @private + * @param {Object} prototype The object to inherit from. + * @returns {Object} Returns the new object. + */ + function baseCreate(prototype, properties) { + return isObject(prototype) ? nativeCreate(prototype) : {}; + } + // fallback for browsers without `Object.create` + if (!nativeCreate) { + baseCreate = (function() { + function Object() {} + return function(prototype) { + if (isObject(prototype)) { + Object.prototype = prototype; + var result = new Object; + Object.prototype = null; + } + return result || root.Object(); + }; + }()); + } + + /** + * The base implementation of `_.createCallback` without support for creating + * "_.pluck" or "_.where" style callbacks. + * + * @private + * @param {*} [func=identity] The value to convert to a callback. + * @param {*} [thisArg] The `this` binding of the created callback. + * @param {number} [argCount] The number of arguments the callback accepts. + * @returns {Function} Returns a callback function. + */ + function baseCreateCallback(func, thisArg, argCount) { + if (typeof func != 'function') { + return identity; + } + // exit early for no `thisArg` or already bound by `Function#bind` + if (typeof thisArg == 'undefined' || !('prototype' in func)) { + return func; + } + switch (argCount) { + case 1: return function(value) { + return func.call(thisArg, value); + }; + case 2: return function(a, b) { + return func.call(thisArg, a, b); + }; + case 3: return function(value, index, collection) { + return func.call(thisArg, value, index, collection); + }; + case 4: return function(accumulator, value, index, collection) { + return func.call(thisArg, accumulator, value, index, collection); + }; + } + return bind(func, thisArg); + } + + /** + * The base implementation of `createWrapper` that creates the wrapper and + * sets its meta data. + * + * @private + * @param {Array} bindData The bind data array. + * @returns {Function} Returns the new function. + */ + function baseCreateWrapper(bindData) { + var func = bindData[0], + bitmask = bindData[1], + partialArgs = bindData[2], + partialRightArgs = bindData[3], + thisArg = bindData[4], + arity = bindData[5]; + + var isBind = bitmask & 1, + isBindKey = bitmask & 2, + isCurry = bitmask & 4, + isCurryBound = bitmask & 8, + key = func; + + function bound() { + var thisBinding = isBind ? thisArg : this; + if (partialArgs) { + var args = slice(partialArgs); + push.apply(args, arguments); + } + if (partialRightArgs || isCurry) { + args || (args = slice(arguments)); + if (partialRightArgs) { + push.apply(args, partialRightArgs); + } + if (isCurry && args.length < arity) { + bitmask |= 16 & ~32; + return baseCreateWrapper([func, (isCurryBound ? bitmask : bitmask & ~3), args, null, thisArg, arity]); + } + } + args || (args = arguments); + if (isBindKey) { + func = thisBinding[key]; + } + if (this instanceof bound) { + thisBinding = baseCreate(func.prototype); + var result = func.apply(thisBinding, args); + return isObject(result) ? result : thisBinding; + } + return func.apply(thisBinding, args); + } + return bound; + } + + /** + * The base implementation of `_.difference` that accepts a single array + * of values to exclude. + * + * @private + * @param {Array} array The array to process. + * @param {Array} [values] The array of values to exclude. + * @returns {Array} Returns a new array of filtered values. + */ + function baseDifference(array, values) { + var index = -1, + indexOf = getIndexOf(), + length = array ? array.length : 0, + result = []; + + while (++index < length) { + var value = array[index]; + if (indexOf(values, value) < 0) { + result.push(value); + } + } + return result; + } + + /** + * The base implementation of `_.flatten` without support for callback + * shorthands or `thisArg` binding. + * + * @private + * @param {Array} array The array to flatten. + * @param {boolean} [isShallow=false] A flag to restrict flattening to a single level. + * @param {boolean} [isStrict=false] A flag to restrict flattening to arrays and `arguments` objects. + * @param {number} [fromIndex=0] The index to start from. + * @returns {Array} Returns a new flattened array. + */ + function baseFlatten(array, isShallow, isStrict, fromIndex) { + var index = (fromIndex || 0) - 1, + length = array ? array.length : 0, + result = []; + + while (++index < length) { + var value = array[index]; + + if (value && typeof value == 'object' && typeof value.length == 'number' + && (isArray(value) || isArguments(value))) { + // recursively flatten arrays (susceptible to call stack limits) + if (!isShallow) { + value = baseFlatten(value, isShallow, isStrict); + } + var valIndex = -1, + valLength = value.length, + resIndex = result.length; + + result.length += valLength; + while (++valIndex < valLength) { + result[resIndex++] = value[valIndex]; + } + } else if (!isStrict) { + result.push(value); + } + } + return result; + } + + /** + * The base implementation of `_.isEqual`, without support for `thisArg` binding, + * that allows partial "_.where" style comparisons. + * + * @private + * @param {*} a The value to compare. + * @param {*} b The other value to compare. + * @param {Function} [callback] The function to customize comparing values. + * @param {Function} [isWhere=false] A flag to indicate performing partial comparisons. + * @param {Array} [stackA=[]] Tracks traversed `a` objects. + * @param {Array} [stackB=[]] Tracks traversed `b` objects. + * @returns {boolean} Returns `true` if the values are equivalent, else `false`. + */ + function baseIsEqual(a, b, stackA, stackB) { + if (a === b) { + return a !== 0 || (1 / a == 1 / b); + } + var type = typeof a, + otherType = typeof b; + + if (a === a && + !(a && objectTypes[type]) && + !(b && objectTypes[otherType])) { + return false; + } + if (a == null || b == null) { + return a === b; + } + var className = toString.call(a), + otherClass = toString.call(b); + + if (className != otherClass) { + return false; + } + switch (className) { + case boolClass: + case dateClass: + return +a == +b; + + case numberClass: + return a != +a + ? b != +b + : (a == 0 ? (1 / a == 1 / b) : a == +b); + + case regexpClass: + case stringClass: + return a == String(b); + } + var isArr = className == arrayClass; + if (!isArr) { + var aWrapped = a instanceof lodash, + bWrapped = b instanceof lodash; + + if (aWrapped || bWrapped) { + return baseIsEqual(aWrapped ? a.__wrapped__ : a, bWrapped ? b.__wrapped__ : b, stackA, stackB); + } + if (className != objectClass) { + return false; + } + var ctorA = a.constructor, + ctorB = b.constructor; + + if (ctorA != ctorB && + !(isFunction(ctorA) && ctorA instanceof ctorA && isFunction(ctorB) && ctorB instanceof ctorB) && + ('constructor' in a && 'constructor' in b) + ) { + return false; + } + } + stackA || (stackA = []); + stackB || (stackB = []); + + var length = stackA.length; + while (length--) { + if (stackA[length] == a) { + return stackB[length] == b; + } + } + var result = true, + size = 0; + + stackA.push(a); + stackB.push(b); + + if (isArr) { + size = b.length; + result = size == a.length; + + if (result) { + while (size--) { + if (!(result = baseIsEqual(a[size], b[size], stackA, stackB))) { + break; + } + } + } + } + else { + forIn(b, function(value, key, b) { + if (hasOwnProperty.call(b, key)) { + size++; + return !(result = hasOwnProperty.call(a, key) && baseIsEqual(a[key], value, stackA, stackB)) && indicatorObject; + } + }); + + if (result) { + forIn(a, function(value, key, a) { + if (hasOwnProperty.call(a, key)) { + return !(result = --size > -1) && indicatorObject; + } + }); + } + } + stackA.pop(); + stackB.pop(); + return result; + } + + /** + * The base implementation of `_.random` without argument juggling or support + * for returning floating-point numbers. + * + * @private + * @param {number} min The minimum possible value. + * @param {number} max The maximum possible value. + * @returns {number} Returns a random number. + */ + function baseRandom(min, max) { + return min + floor(nativeRandom() * (max - min + 1)); + } + + /** + * The base implementation of `_.uniq` without support for callback shorthands + * or `thisArg` binding. + * + * @private + * @param {Array} array The array to process. + * @param {boolean} [isSorted=false] A flag to indicate that `array` is sorted. + * @param {Function} [callback] The function called per iteration. + * @returns {Array} Returns a duplicate-value-free array. + */ + function baseUniq(array, isSorted, callback) { + var index = -1, + indexOf = getIndexOf(), + length = array ? array.length : 0, + result = [], + seen = callback ? [] : result; + + while (++index < length) { + var value = array[index], + computed = callback ? callback(value, index, array) : value; + + if (isSorted + ? !index || seen[seen.length - 1] !== computed + : indexOf(seen, computed) < 0 + ) { + if (callback) { + seen.push(computed); + } + result.push(value); + } + } + return result; + } + + /** + * Creates a function that aggregates a collection, creating an object composed + * of keys generated from the results of running each element of the collection + * through a callback. The given `setter` function sets the keys and values + * of the composed object. + * + * @private + * @param {Function} setter The setter function. + * @returns {Function} Returns the new aggregator function. + */ + function createAggregator(setter) { + return function(collection, callback, thisArg) { + var result = {}; + callback = createCallback(callback, thisArg, 3); + + var index = -1, + length = collection ? collection.length : 0; + + if (typeof length == 'number') { + while (++index < length) { + var value = collection[index]; + setter(result, value, callback(value, index, collection), collection); + } + } else { + forOwn(collection, function(value, key, collection) { + setter(result, value, callback(value, key, collection), collection); + }); + } + return result; + }; + } + + /** + * Creates a function that, when called, either curries or invokes `func` + * with an optional `this` binding and partially applied arguments. + * + * @private + * @param {Function|string} func The function or method name to reference. + * @param {number} bitmask The bitmask of method flags to compose. + * The bitmask may be composed of the following flags: + * 1 - `_.bind` + * 2 - `_.bindKey` + * 4 - `_.curry` + * 8 - `_.curry` (bound) + * 16 - `_.partial` + * 32 - `_.partialRight` + * @param {Array} [partialArgs] An array of arguments to prepend to those + * provided to the new function. + * @param {Array} [partialRightArgs] An array of arguments to append to those + * provided to the new function. + * @param {*} [thisArg] The `this` binding of `func`. + * @param {number} [arity] The arity of `func`. + * @returns {Function} Returns the new function. + */ + function createWrapper(func, bitmask, partialArgs, partialRightArgs, thisArg, arity) { + var isBind = bitmask & 1, + isBindKey = bitmask & 2, + isCurry = bitmask & 4, + isCurryBound = bitmask & 8, + isPartial = bitmask & 16, + isPartialRight = bitmask & 32; + + if (!isBindKey && !isFunction(func)) { + throw new TypeError; + } + if (isPartial && !partialArgs.length) { + bitmask &= ~16; + isPartial = partialArgs = false; + } + if (isPartialRight && !partialRightArgs.length) { + bitmask &= ~32; + isPartialRight = partialRightArgs = false; + } + // fast path for `_.bind` + var creater = (bitmask == 1 || bitmask === 17) ? baseBind : baseCreateWrapper; + return creater([func, bitmask, partialArgs, partialRightArgs, thisArg, arity]); + } + + /** + * Used by `escape` to convert characters to HTML entities. + * + * @private + * @param {string} match The matched character to escape. + * @returns {string} Returns the escaped character. + */ + function escapeHtmlChar(match) { + return htmlEscapes[match]; + } + + /** + * Gets the appropriate "indexOf" function. If the `_.indexOf` method is + * customized, this method returns the custom method, otherwise it returns + * the `baseIndexOf` function. + * + * @private + * @returns {Function} Returns the "indexOf" function. + */ + function getIndexOf() { + var result = (result = lodash.indexOf) === indexOf ? baseIndexOf : result; + return result; + } + + /** + * Checks if `value` is a native function. + * + * @private + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if the `value` is a native function, else `false`. + */ + function isNative(value) { + return typeof value == 'function' && reNative.test(value); + } + + /** + * Used by `unescape` to convert HTML entities to characters. + * + * @private + * @param {string} match The matched character to unescape. + * @returns {string} Returns the unescaped character. + */ + function unescapeHtmlChar(match) { + return htmlUnescapes[match]; + } + + /*--------------------------------------------------------------------------*/ + + /** + * Checks if `value` is an `arguments` object. + * + * @static + * @memberOf _ + * @category Objects + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if the `value` is an `arguments` object, else `false`. + * @example + * + * (function() { return _.isArguments(arguments); })(1, 2, 3); + * // => true + * + * _.isArguments([1, 2, 3]); + * // => false + */ + function isArguments(value) { + return value && typeof value == 'object' && typeof value.length == 'number' && + toString.call(value) == argsClass || false; + } + // fallback for browsers that can't detect `arguments` objects by [[Class]] + if (!isArguments(arguments)) { + isArguments = function(value) { + return value && typeof value == 'object' && typeof value.length == 'number' && + hasOwnProperty.call(value, 'callee') && !propertyIsEnumerable.call(value, 'callee') || false; + }; + } + + /** + * Checks if `value` is an array. + * + * @static + * @memberOf _ + * @type Function + * @category Objects + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if the `value` is an array, else `false`. + * @example + * + * (function() { return _.isArray(arguments); })(); + * // => false + * + * _.isArray([1, 2, 3]); + * // => true + */ + var isArray = nativeIsArray || function(value) { + return value && typeof value == 'object' && typeof value.length == 'number' && + toString.call(value) == arrayClass || false; + }; + + /** + * A fallback implementation of `Object.keys` which produces an array of the + * given object's own enumerable property names. + * + * @private + * @type Function + * @param {Object} object The object to inspect. + * @returns {Array} Returns an array of property names. + */ + var shimKeys = function(object) { + var index, iterable = object, result = []; + if (!iterable) return result; + if (!(objectTypes[typeof object])) return result; + for (index in iterable) { + if (hasOwnProperty.call(iterable, index)) { + result.push(index); + } + } + return result + }; + + /** + * Creates an array composed of the own enumerable property names of an object. + * + * @static + * @memberOf _ + * @category Objects + * @param {Object} object The object to inspect. + * @returns {Array} Returns an array of property names. + * @example + * + * _.keys({ 'one': 1, 'two': 2, 'three': 3 }); + * // => ['one', 'two', 'three'] (property order is not guaranteed across environments) + */ + var keys = !nativeKeys ? shimKeys : function(object) { + if (!isObject(object)) { + return []; + } + return nativeKeys(object); + }; + + /** + * Used to convert characters to HTML entities: + * + * Though the `>` character is escaped for symmetry, characters like `>` and `/` + * don't require escaping in HTML and have no special meaning unless they're part + * of a tag or an unquoted attribute value. + * http://mathiasbynens.be/notes/ambiguous-ampersands (under "semi-related fun fact") + */ + var htmlEscapes = { + '&': '&', + '<': '<', + '>': '>', + '"': '"', + "'": ''' + }; + + /** Used to convert HTML entities to characters */ + var htmlUnescapes = invert(htmlEscapes); + + /** Used to match HTML entities and HTML characters */ + var reEscapedHtml = RegExp('(' + keys(htmlUnescapes).join('|') + ')', 'g'), + reUnescapedHtml = RegExp('[' + keys(htmlEscapes).join('') + ']', 'g'); + + /*--------------------------------------------------------------------------*/ + + /** + * Assigns own enumerable properties of source object(s) to the destination + * object. Subsequent sources will overwrite property assignments of previous + * sources. If a callback is provided it will be executed to produce the + * assigned values. The callback is bound to `thisArg` and invoked with two + * arguments; (objectValue, sourceValue). + * + * @static + * @memberOf _ + * @type Function + * @alias extend + * @category Objects + * @param {Object} object The destination object. + * @param {...Object} [source] The source objects. + * @param {Function} [callback] The function to customize assigning values. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Object} Returns the destination object. + * @example + * + * _.assign({ 'name': 'fred' }, { 'employer': 'slate' }); + * // => { 'name': 'fred', 'employer': 'slate' } + * + * var defaults = _.partialRight(_.assign, function(a, b) { + * return typeof a == 'undefined' ? b : a; + * }); + * + * var object = { 'name': 'barney' }; + * defaults(object, { 'name': 'fred', 'employer': 'slate' }); + * // => { 'name': 'barney', 'employer': 'slate' } + */ + function assign(object) { + if (!object) { + return object; + } + for (var argsIndex = 1, argsLength = arguments.length; argsIndex < argsLength; argsIndex++) { + var iterable = arguments[argsIndex]; + if (iterable) { + for (var key in iterable) { + object[key] = iterable[key]; + } + } + } + return object; + } + + /** + * Creates a clone of `value`. If `isDeep` is `true` nested objects will also + * be cloned, otherwise they will be assigned by reference. If a callback + * is provided it will be executed to produce the cloned values. If the + * callback returns `undefined` cloning will be handled by the method instead. + * The callback is bound to `thisArg` and invoked with one argument; (value). + * + * @static + * @memberOf _ + * @category Objects + * @param {*} value The value to clone. + * @param {boolean} [isDeep=false] Specify a deep clone. + * @param {Function} [callback] The function to customize cloning values. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {*} Returns the cloned value. + * @example + * + * var characters = [ + * { 'name': 'barney', 'age': 36 }, + * { 'name': 'fred', 'age': 40 } + * ]; + * + * var shallow = _.clone(characters); + * shallow[0] === characters[0]; + * // => true + * + * var deep = _.clone(characters, true); + * deep[0] === characters[0]; + * // => false + * + * _.mixin({ + * 'clone': _.partialRight(_.clone, function(value) { + * return _.isElement(value) ? value.cloneNode(false) : undefined; + * }) + * }); + * + * var clone = _.clone(document.body); + * clone.childNodes.length; + * // => 0 + */ + function clone(value) { + return isObject(value) + ? (isArray(value) ? slice(value) : assign({}, value)) + : value; + } + + /** + * Assigns own enumerable properties of source object(s) to the destination + * object for all destination properties that resolve to `undefined`. Once a + * property is set, additional defaults of the same property will be ignored. + * + * @static + * @memberOf _ + * @type Function + * @category Objects + * @param {Object} object The destination object. + * @param {...Object} [source] The source objects. + * @param- {Object} [guard] Allows working with `_.reduce` without using its + * `key` and `object` arguments as sources. + * @returns {Object} Returns the destination object. + * @example + * + * var object = { 'name': 'barney' }; + * _.defaults(object, { 'name': 'fred', 'employer': 'slate' }); + * // => { 'name': 'barney', 'employer': 'slate' } + */ + function defaults(object) { + if (!object) { + return object; + } + for (var argsIndex = 1, argsLength = arguments.length; argsIndex < argsLength; argsIndex++) { + var iterable = arguments[argsIndex]; + if (iterable) { + for (var key in iterable) { + if (typeof object[key] == 'undefined') { + object[key] = iterable[key]; + } + } + } + } + return object; + } + + /** + * Iterates over own and inherited enumerable properties of an object, + * executing the callback for each property. The callback is bound to `thisArg` + * and invoked with three arguments; (value, key, object). Callbacks may exit + * iteration early by explicitly returning `false`. + * + * @static + * @memberOf _ + * @type Function + * @category Objects + * @param {Object} object The object to iterate over. + * @param {Function} [callback=identity] The function called per iteration. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Object} Returns `object`. + * @example + * + * function Shape() { + * this.x = 0; + * this.y = 0; + * } + * + * Shape.prototype.move = function(x, y) { + * this.x += x; + * this.y += y; + * }; + * + * _.forIn(new Shape, function(value, key) { + * console.log(key); + * }); + * // => logs 'x', 'y', and 'move' (property order is not guaranteed across environments) + */ + var forIn = function(collection, callback) { + var index, iterable = collection, result = iterable; + if (!iterable) return result; + if (!objectTypes[typeof iterable]) return result; + for (index in iterable) { + if (callback(iterable[index], index, collection) === indicatorObject) return result; + } + return result + }; + + /** + * Iterates over own enumerable properties of an object, executing the callback + * for each property. The callback is bound to `thisArg` and invoked with three + * arguments; (value, key, object). Callbacks may exit iteration early by + * explicitly returning `false`. + * + * @static + * @memberOf _ + * @type Function + * @category Objects + * @param {Object} object The object to iterate over. + * @param {Function} [callback=identity] The function called per iteration. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Object} Returns `object`. + * @example + * + * _.forOwn({ '0': 'zero', '1': 'one', 'length': 2 }, function(num, key) { + * console.log(key); + * }); + * // => logs '0', '1', and 'length' (property order is not guaranteed across environments) + */ + var forOwn = function(collection, callback) { + var index, iterable = collection, result = iterable; + if (!iterable) return result; + if (!objectTypes[typeof iterable]) return result; + for (index in iterable) { + if (hasOwnProperty.call(iterable, index)) { + if (callback(iterable[index], index, collection) === indicatorObject) return result; + } + } + return result + }; + + /** + * Creates a sorted array of property names of all enumerable properties, + * own and inherited, of `object` that have function values. + * + * @static + * @memberOf _ + * @alias methods + * @category Objects + * @param {Object} object The object to inspect. + * @returns {Array} Returns an array of property names that have function values. + * @example + * + * _.functions(_); + * // => ['all', 'any', 'bind', 'bindAll', 'clone', 'compact', 'compose', ...] + */ + function functions(object) { + var result = []; + forIn(object, function(value, key) { + if (isFunction(value)) { + result.push(key); + } + }); + return result.sort(); + } + + /** + * Checks if the specified property name exists as a direct property of `object`, + * instead of an inherited property. + * + * @static + * @memberOf _ + * @category Objects + * @param {Object} object The object to inspect. + * @param {string} key The name of the property to check. + * @returns {boolean} Returns `true` if key is a direct property, else `false`. + * @example + * + * _.has({ 'a': 1, 'b': 2, 'c': 3 }, 'b'); + * // => true + */ + function has(object, key) { + return object ? hasOwnProperty.call(object, key) : false; + } + + /** + * Creates an object composed of the inverted keys and values of the given object. + * + * @static + * @memberOf _ + * @category Objects + * @param {Object} object The object to invert. + * @returns {Object} Returns the created inverted object. + * @example + * + * _.invert({ 'first': 'fred', 'second': 'barney' }); + * // => { 'fred': 'first', 'barney': 'second' } + */ + function invert(object) { + var index = -1, + props = keys(object), + length = props.length, + result = {}; + + while (++index < length) { + var key = props[index]; + result[object[key]] = key; + } + return result; + } + + /** + * Checks if `value` is a boolean value. + * + * @static + * @memberOf _ + * @category Objects + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if the `value` is a boolean value, else `false`. + * @example + * + * _.isBoolean(null); + * // => false + */ + function isBoolean(value) { + return value === true || value === false || + value && typeof value == 'object' && toString.call(value) == boolClass || false; + } + + /** + * Checks if `value` is a date. + * + * @static + * @memberOf _ + * @category Objects + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if the `value` is a date, else `false`. + * @example + * + * _.isDate(new Date); + * // => true + */ + function isDate(value) { + return value && typeof value == 'object' && toString.call(value) == dateClass || false; + } + + /** + * Checks if `value` is a DOM element. + * + * @static + * @memberOf _ + * @category Objects + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if the `value` is a DOM element, else `false`. + * @example + * + * _.isElement(document.body); + * // => true + */ + function isElement(value) { + return value && value.nodeType === 1 || false; + } + + /** + * Checks if `value` is empty. Arrays, strings, or `arguments` objects with a + * length of `0` and objects with no own enumerable properties are considered + * "empty". + * + * @static + * @memberOf _ + * @category Objects + * @param {Array|Object|string} value The value to inspect. + * @returns {boolean} Returns `true` if the `value` is empty, else `false`. + * @example + * + * _.isEmpty([1, 2, 3]); + * // => false + * + * _.isEmpty({}); + * // => true + * + * _.isEmpty(''); + * // => true + */ + function isEmpty(value) { + if (!value) { + return true; + } + if (isArray(value) || isString(value)) { + return !value.length; + } + for (var key in value) { + if (hasOwnProperty.call(value, key)) { + return false; + } + } + return true; + } + + /** + * Performs a deep comparison between two values to determine if they are + * equivalent to each other. If a callback is provided it will be executed + * to compare values. If the callback returns `undefined` comparisons will + * be handled by the method instead. The callback is bound to `thisArg` and + * invoked with two arguments; (a, b). + * + * @static + * @memberOf _ + * @category Objects + * @param {*} a The value to compare. + * @param {*} b The other value to compare. + * @param {Function} [callback] The function to customize comparing values. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {boolean} Returns `true` if the values are equivalent, else `false`. + * @example + * + * var object = { 'name': 'fred' }; + * var copy = { 'name': 'fred' }; + * + * object == copy; + * // => false + * + * _.isEqual(object, copy); + * // => true + * + * var words = ['hello', 'goodbye']; + * var otherWords = ['hi', 'goodbye']; + * + * _.isEqual(words, otherWords, function(a, b) { + * var reGreet = /^(?:hello|hi)$/i, + * aGreet = _.isString(a) && reGreet.test(a), + * bGreet = _.isString(b) && reGreet.test(b); + * + * return (aGreet || bGreet) ? (aGreet == bGreet) : undefined; + * }); + * // => true + */ + function isEqual(a, b) { + return baseIsEqual(a, b); + } + + /** + * Checks if `value` is, or can be coerced to, a finite number. + * + * Note: This is not the same as native `isFinite` which will return true for + * booleans and empty strings. See http://es5.github.io/#x15.1.2.5. + * + * @static + * @memberOf _ + * @category Objects + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if the `value` is finite, else `false`. + * @example + * + * _.isFinite(-101); + * // => true + * + * _.isFinite('10'); + * // => true + * + * _.isFinite(true); + * // => false + * + * _.isFinite(''); + * // => false + * + * _.isFinite(Infinity); + * // => false + */ + function isFinite(value) { + return nativeIsFinite(value) && !nativeIsNaN(parseFloat(value)); + } + + /** + * Checks if `value` is a function. + * + * @static + * @memberOf _ + * @category Objects + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if the `value` is a function, else `false`. + * @example + * + * _.isFunction(_); + * // => true + */ + function isFunction(value) { + return typeof value == 'function'; + } + // fallback for older versions of Chrome and Safari + if (isFunction(/x/)) { + isFunction = function(value) { + return typeof value == 'function' && toString.call(value) == funcClass; + }; + } + + /** + * Checks if `value` is the language type of Object. + * (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`) + * + * @static + * @memberOf _ + * @category Objects + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if the `value` is an object, else `false`. + * @example + * + * _.isObject({}); + * // => true + * + * _.isObject([1, 2, 3]); + * // => true + * + * _.isObject(1); + * // => false + */ + function isObject(value) { + // check if the value is the ECMAScript language type of Object + // http://es5.github.io/#x8 + // and avoid a V8 bug + // http://code.google.com/p/v8/issues/detail?id=2291 + return !!(value && objectTypes[typeof value]); + } + + /** + * Checks if `value` is `NaN`. + * + * Note: This is not the same as native `isNaN` which will return `true` for + * `undefined` and other non-numeric values. See http://es5.github.io/#x15.1.2.4. + * + * @static + * @memberOf _ + * @category Objects + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if the `value` is `NaN`, else `false`. + * @example + * + * _.isNaN(NaN); + * // => true + * + * _.isNaN(new Number(NaN)); + * // => true + * + * isNaN(undefined); + * // => true + * + * _.isNaN(undefined); + * // => false + */ + function isNaN(value) { + // `NaN` as a primitive is the only value that is not equal to itself + // (perform the [[Class]] check first to avoid errors with some host objects in IE) + return isNumber(value) && value != +value; + } + + /** + * Checks if `value` is `null`. + * + * @static + * @memberOf _ + * @category Objects + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if the `value` is `null`, else `false`. + * @example + * + * _.isNull(null); + * // => true + * + * _.isNull(undefined); + * // => false + */ + function isNull(value) { + return value === null; + } + + /** + * Checks if `value` is a number. + * + * Note: `NaN` is considered a number. See http://es5.github.io/#x8.5. + * + * @static + * @memberOf _ + * @category Objects + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if the `value` is a number, else `false`. + * @example + * + * _.isNumber(8.4 * 5); + * // => true + */ + function isNumber(value) { + return typeof value == 'number' || + value && typeof value == 'object' && toString.call(value) == numberClass || false; + } + + /** + * Checks if `value` is a regular expression. + * + * @static + * @memberOf _ + * @category Objects + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if the `value` is a regular expression, else `false`. + * @example + * + * _.isRegExp(/fred/); + * // => true + */ + function isRegExp(value) { + return value && objectTypes[typeof value] && toString.call(value) == regexpClass || false; + } + + /** + * Checks if `value` is a string. + * + * @static + * @memberOf _ + * @category Objects + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if the `value` is a string, else `false`. + * @example + * + * _.isString('fred'); + * // => true + */ + function isString(value) { + return typeof value == 'string' || + value && typeof value == 'object' && toString.call(value) == stringClass || false; + } + + /** + * Checks if `value` is `undefined`. + * + * @static + * @memberOf _ + * @category Objects + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if the `value` is `undefined`, else `false`. + * @example + * + * _.isUndefined(void 0); + * // => true + */ + function isUndefined(value) { + return typeof value == 'undefined'; + } + + /** + * Creates a shallow clone of `object` excluding the specified properties. + * Property names may be specified as individual arguments or as arrays of + * property names. If a callback is provided it will be executed for each + * property of `object` omitting the properties the callback returns truey + * for. The callback is bound to `thisArg` and invoked with three arguments; + * (value, key, object). + * + * @static + * @memberOf _ + * @category Objects + * @param {Object} object The source object. + * @param {Function|...string|string[]} [callback] The properties to omit or the + * function called per iteration. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Object} Returns an object without the omitted properties. + * @example + * + * _.omit({ 'name': 'fred', 'age': 40 }, 'age'); + * // => { 'name': 'fred' } + * + * _.omit({ 'name': 'fred', 'age': 40 }, function(value) { + * return typeof value == 'number'; + * }); + * // => { 'name': 'fred' } + */ + function omit(object) { + var props = []; + forIn(object, function(value, key) { + props.push(key); + }); + props = baseDifference(props, baseFlatten(arguments, true, false, 1)); + + var index = -1, + length = props.length, + result = {}; + + while (++index < length) { + var key = props[index]; + result[key] = object[key]; + } + return result; + } + + /** + * Creates a two dimensional array of an object's key-value pairs, + * i.e. `[[key1, value1], [key2, value2]]`. + * + * @static + * @memberOf _ + * @category Objects + * @param {Object} object The object to inspect. + * @returns {Array} Returns new array of key-value pairs. + * @example + * + * _.pairs({ 'barney': 36, 'fred': 40 }); + * // => [['barney', 36], ['fred', 40]] (property order is not guaranteed across environments) + */ + function pairs(object) { + var index = -1, + props = keys(object), + length = props.length, + result = Array(length); + + while (++index < length) { + var key = props[index]; + result[index] = [key, object[key]]; + } + return result; + } + + /** + * Creates a shallow clone of `object` composed of the specified properties. + * Property names may be specified as individual arguments or as arrays of + * property names. If a callback is provided it will be executed for each + * property of `object` picking the properties the callback returns truey + * for. The callback is bound to `thisArg` and invoked with three arguments; + * (value, key, object). + * + * @static + * @memberOf _ + * @category Objects + * @param {Object} object The source object. + * @param {Function|...string|string[]} [callback] The function called per + * iteration or property names to pick, specified as individual property + * names or arrays of property names. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Object} Returns an object composed of the picked properties. + * @example + * + * _.pick({ 'name': 'fred', '_userid': 'fred1' }, 'name'); + * // => { 'name': 'fred' } + * + * _.pick({ 'name': 'fred', '_userid': 'fred1' }, function(value, key) { + * return key.charAt(0) != '_'; + * }); + * // => { 'name': 'fred' } + */ + function pick(object) { + var index = -1, + props = baseFlatten(arguments, true, false, 1), + length = props.length, + result = {}; + + while (++index < length) { + var key = props[index]; + if (key in object) { + result[key] = object[key]; + } + } + return result; + } + + /** + * Creates an array composed of the own enumerable property values of `object`. + * + * @static + * @memberOf _ + * @category Objects + * @param {Object} object The object to inspect. + * @returns {Array} Returns an array of property values. + * @example + * + * _.values({ 'one': 1, 'two': 2, 'three': 3 }); + * // => [1, 2, 3] (property order is not guaranteed across environments) + */ + function values(object) { + var index = -1, + props = keys(object), + length = props.length, + result = Array(length); + + while (++index < length) { + result[index] = object[props[index]]; + } + return result; + } + + /*--------------------------------------------------------------------------*/ + + /** + * Checks if a given value is present in a collection using strict equality + * for comparisons, i.e. `===`. If `fromIndex` is negative, it is used as the + * offset from the end of the collection. + * + * @static + * @memberOf _ + * @alias include + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {*} target The value to check for. + * @param {number} [fromIndex=0] The index to search from. + * @returns {boolean} Returns `true` if the `target` element is found, else `false`. + * @example + * + * _.contains([1, 2, 3], 1); + * // => true + * + * _.contains([1, 2, 3], 1, 2); + * // => false + * + * _.contains({ 'name': 'fred', 'age': 40 }, 'fred'); + * // => true + * + * _.contains('pebbles', 'eb'); + * // => true + */ + function contains(collection, target) { + var indexOf = getIndexOf(), + length = collection ? collection.length : 0, + result = false; + if (length && typeof length == 'number') { + result = indexOf(collection, target) > -1; + } else { + forOwn(collection, function(value) { + return (result = value === target) && indicatorObject; + }); + } + return result; + } + + /** + * Creates an object composed of keys generated from the results of running + * each element of `collection` through the callback. The corresponding value + * of each key is the number of times the key was returned by the callback. + * The callback is bound to `thisArg` and invoked with three arguments; + * (value, index|key, collection). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [callback=identity] The function called + * per iteration. If a property name or object is provided it will be used + * to create a "_.pluck" or "_.where" style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Object} Returns the composed aggregate object. + * @example + * + * _.countBy([4.3, 6.1, 6.4], function(num) { return Math.floor(num); }); + * // => { '4': 1, '6': 2 } + * + * _.countBy([4.3, 6.1, 6.4], function(num) { return this.floor(num); }, Math); + * // => { '4': 1, '6': 2 } + * + * _.countBy(['one', 'two', 'three'], 'length'); + * // => { '3': 2, '5': 1 } + */ + var countBy = createAggregator(function(result, value, key) { + (hasOwnProperty.call(result, key) ? result[key]++ : result[key] = 1); + }); + + /** + * Checks if the given callback returns truey value for **all** elements of + * a collection. The callback is bound to `thisArg` and invoked with three + * arguments; (value, index|key, collection). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @alias all + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [callback=identity] The function called + * per iteration. If a property name or object is provided it will be used + * to create a "_.pluck" or "_.where" style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {boolean} Returns `true` if all elements passed the callback check, + * else `false`. + * @example + * + * _.every([true, 1, null, 'yes']); + * // => false + * + * var characters = [ + * { 'name': 'barney', 'age': 36 }, + * { 'name': 'fred', 'age': 40 } + * ]; + * + * // using "_.pluck" callback shorthand + * _.every(characters, 'age'); + * // => true + * + * // using "_.where" callback shorthand + * _.every(characters, { 'age': 36 }); + * // => false + */ + function every(collection, callback, thisArg) { + var result = true; + callback = createCallback(callback, thisArg, 3); + + var index = -1, + length = collection ? collection.length : 0; + + if (typeof length == 'number') { + while (++index < length) { + if (!(result = !!callback(collection[index], index, collection))) { + break; + } + } + } else { + forOwn(collection, function(value, index, collection) { + return !(result = !!callback(value, index, collection)) && indicatorObject; + }); + } + return result; + } + + /** + * Iterates over elements of a collection, returning an array of all elements + * the callback returns truey for. The callback is bound to `thisArg` and + * invoked with three arguments; (value, index|key, collection). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @alias select + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [callback=identity] The function called + * per iteration. If a property name or object is provided it will be used + * to create a "_.pluck" or "_.where" style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Array} Returns a new array of elements that passed the callback check. + * @example + * + * var evens = _.filter([1, 2, 3, 4, 5, 6], function(num) { return num % 2 == 0; }); + * // => [2, 4, 6] + * + * var characters = [ + * { 'name': 'barney', 'age': 36, 'blocked': false }, + * { 'name': 'fred', 'age': 40, 'blocked': true } + * ]; + * + * // using "_.pluck" callback shorthand + * _.filter(characters, 'blocked'); + * // => [{ 'name': 'fred', 'age': 40, 'blocked': true }] + * + * // using "_.where" callback shorthand + * _.filter(characters, { 'age': 36 }); + * // => [{ 'name': 'barney', 'age': 36, 'blocked': false }] + */ + function filter(collection, callback, thisArg) { + var result = []; + callback = createCallback(callback, thisArg, 3); + + var index = -1, + length = collection ? collection.length : 0; + + if (typeof length == 'number') { + while (++index < length) { + var value = collection[index]; + if (callback(value, index, collection)) { + result.push(value); + } + } + } else { + forOwn(collection, function(value, index, collection) { + if (callback(value, index, collection)) { + result.push(value); + } + }); + } + return result; + } + + /** + * Iterates over elements of a collection, returning the first element that + * the callback returns truey for. The callback is bound to `thisArg` and + * invoked with three arguments; (value, index|key, collection). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @alias detect, findWhere + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [callback=identity] The function called + * per iteration. If a property name or object is provided it will be used + * to create a "_.pluck" or "_.where" style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {*} Returns the found element, else `undefined`. + * @example + * + * var characters = [ + * { 'name': 'barney', 'age': 36, 'blocked': false }, + * { 'name': 'fred', 'age': 40, 'blocked': true }, + * { 'name': 'pebbles', 'age': 1, 'blocked': false } + * ]; + * + * _.find(characters, function(chr) { + * return chr.age < 40; + * }); + * // => { 'name': 'barney', 'age': 36, 'blocked': false } + * + * // using "_.where" callback shorthand + * _.find(characters, { 'age': 1 }); + * // => { 'name': 'pebbles', 'age': 1, 'blocked': false } + * + * // using "_.pluck" callback shorthand + * _.find(characters, 'blocked'); + * // => { 'name': 'fred', 'age': 40, 'blocked': true } + */ + function find(collection, callback, thisArg) { + callback = createCallback(callback, thisArg, 3); + + var index = -1, + length = collection ? collection.length : 0; + + if (typeof length == 'number') { + while (++index < length) { + var value = collection[index]; + if (callback(value, index, collection)) { + return value; + } + } + } else { + var result; + forOwn(collection, function(value, index, collection) { + if (callback(value, index, collection)) { + result = value; + return indicatorObject; + } + }); + return result; + } + } + + /** + * Examines each element in a `collection`, returning the first that + * has the given properties. When checking `properties`, this method + * performs a deep comparison between values to determine if they are + * equivalent to each other. + * + * @static + * @memberOf _ + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Object} properties The object of property values to filter by. + * @returns {*} Returns the found element, else `undefined`. + * @example + * + * var food = [ + * { 'name': 'apple', 'organic': false, 'type': 'fruit' }, + * { 'name': 'banana', 'organic': true, 'type': 'fruit' }, + * { 'name': 'beet', 'organic': false, 'type': 'vegetable' } + * ]; + * + * _.findWhere(food, { 'type': 'vegetable' }); + * // => { 'name': 'beet', 'organic': false, 'type': 'vegetable' } + */ + function findWhere(object, properties) { + return where(object, properties, true); + } + + /** + * Iterates over elements of a collection, executing the callback for each + * element. The callback is bound to `thisArg` and invoked with three arguments; + * (value, index|key, collection). Callbacks may exit iteration early by + * explicitly returning `false`. + * + * Note: As with other "Collections" methods, objects with a `length` property + * are iterated like arrays. To avoid this behavior `_.forIn` or `_.forOwn` + * may be used for object iteration. + * + * @static + * @memberOf _ + * @alias each + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} [callback=identity] The function called per iteration. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Array|Object|string} Returns `collection`. + * @example + * + * _([1, 2, 3]).forEach(function(num) { console.log(num); }).join(','); + * // => logs each number and returns '1,2,3' + * + * _.forEach({ 'one': 1, 'two': 2, 'three': 3 }, function(num) { console.log(num); }); + * // => logs each number and returns the object (property order is not guaranteed across environments) + */ + function forEach(collection, callback, thisArg) { + var index = -1, + length = collection ? collection.length : 0; + + callback = callback && typeof thisArg == 'undefined' ? callback : baseCreateCallback(callback, thisArg, 3); + if (typeof length == 'number') { + while (++index < length) { + if (callback(collection[index], index, collection) === indicatorObject) { + break; + } + } + } else { + forOwn(collection, callback); + } + } + + /** + * This method is like `_.forEach` except that it iterates over elements + * of a `collection` from right to left. + * + * @static + * @memberOf _ + * @alias eachRight + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} [callback=identity] The function called per iteration. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Array|Object|string} Returns `collection`. + * @example + * + * _([1, 2, 3]).forEachRight(function(num) { console.log(num); }).join(','); + * // => logs each number from right to left and returns '3,2,1' + */ + function forEachRight(collection, callback) { + var length = collection ? collection.length : 0; + if (typeof length == 'number') { + while (length--) { + if (callback(collection[length], length, collection) === false) { + break; + } + } + } else { + var props = keys(collection); + length = props.length; + forOwn(collection, function(value, key, collection) { + key = props ? props[--length] : --length; + return callback(collection[key], key, collection) === false && indicatorObject; + }); + } + } + + /** + * Creates an object composed of keys generated from the results of running + * each element of a collection through the callback. The corresponding value + * of each key is an array of the elements responsible for generating the key. + * The callback is bound to `thisArg` and invoked with three arguments; + * (value, index|key, collection). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false` + * + * @static + * @memberOf _ + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [callback=identity] The function called + * per iteration. If a property name or object is provided it will be used + * to create a "_.pluck" or "_.where" style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Object} Returns the composed aggregate object. + * @example + * + * _.groupBy([4.2, 6.1, 6.4], function(num) { return Math.floor(num); }); + * // => { '4': [4.2], '6': [6.1, 6.4] } + * + * _.groupBy([4.2, 6.1, 6.4], function(num) { return this.floor(num); }, Math); + * // => { '4': [4.2], '6': [6.1, 6.4] } + * + * // using "_.pluck" callback shorthand + * _.groupBy(['one', 'two', 'three'], 'length'); + * // => { '3': ['one', 'two'], '5': ['three'] } + */ + var groupBy = createAggregator(function(result, value, key) { + (hasOwnProperty.call(result, key) ? result[key] : result[key] = []).push(value); + }); + + /** + * Creates an object composed of keys generated from the results of running + * each element of the collection through the given callback. The corresponding + * value of each key is the last element responsible for generating the key. + * The callback is bound to `thisArg` and invoked with three arguments; + * (value, index|key, collection). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [callback=identity] The function called + * per iteration. If a property name or object is provided it will be used + * to create a "_.pluck" or "_.where" style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Object} Returns the composed aggregate object. + * @example + * + * var keys = [ + * { 'dir': 'left', 'code': 97 }, + * { 'dir': 'right', 'code': 100 } + * ]; + * + * _.indexBy(keys, 'dir'); + * // => { 'left': { 'dir': 'left', 'code': 97 }, 'right': { 'dir': 'right', 'code': 100 } } + * + * _.indexBy(keys, function(key) { return String.fromCharCode(key.code); }); + * // => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } } + * + * _.indexBy(characters, function(key) { this.fromCharCode(key.code); }, String); + * // => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } } + */ + var indexBy = createAggregator(function(result, value, key) { + result[key] = value; + }); + + /** + * Invokes the method named by `methodName` on each element in the `collection` + * returning an array of the results of each invoked method. Additional arguments + * will be provided to each invoked method. If `methodName` is a function it + * will be invoked for, and `this` bound to, each element in the `collection`. + * + * @static + * @memberOf _ + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|string} methodName The name of the method to invoke or + * the function invoked per iteration. + * @param {...*} [arg] Arguments to invoke the method with. + * @returns {Array} Returns a new array of the results of each invoked method. + * @example + * + * _.invoke([[5, 1, 7], [3, 2, 1]], 'sort'); + * // => [[1, 5, 7], [1, 2, 3]] + * + * _.invoke([123, 456], String.prototype.split, ''); + * // => [['1', '2', '3'], ['4', '5', '6']] + */ + function invoke(collection, methodName) { + var args = slice(arguments, 2), + index = -1, + isFunc = typeof methodName == 'function', + length = collection ? collection.length : 0, + result = Array(typeof length == 'number' ? length : 0); + + forEach(collection, function(value) { + result[++index] = (isFunc ? methodName : value[methodName]).apply(value, args); + }); + return result; + } + + /** + * Creates an array of values by running each element in the collection + * through the callback. The callback is bound to `thisArg` and invoked with + * three arguments; (value, index|key, collection). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @alias collect + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [callback=identity] The function called + * per iteration. If a property name or object is provided it will be used + * to create a "_.pluck" or "_.where" style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Array} Returns a new array of the results of each `callback` execution. + * @example + * + * _.map([1, 2, 3], function(num) { return num * 3; }); + * // => [3, 6, 9] + * + * _.map({ 'one': 1, 'two': 2, 'three': 3 }, function(num) { return num * 3; }); + * // => [3, 6, 9] (property order is not guaranteed across environments) + * + * var characters = [ + * { 'name': 'barney', 'age': 36 }, + * { 'name': 'fred', 'age': 40 } + * ]; + * + * // using "_.pluck" callback shorthand + * _.map(characters, 'name'); + * // => ['barney', 'fred'] + */ + function map(collection, callback, thisArg) { + var index = -1, + length = collection ? collection.length : 0; + + callback = createCallback(callback, thisArg, 3); + if (typeof length == 'number') { + var result = Array(length); + while (++index < length) { + result[index] = callback(collection[index], index, collection); + } + } else { + result = []; + forOwn(collection, function(value, key, collection) { + result[++index] = callback(value, key, collection); + }); + } + return result; + } + + /** + * Retrieves the maximum value of a collection. If the collection is empty or + * falsey `-Infinity` is returned. If a callback is provided it will be executed + * for each value in the collection to generate the criterion by which the value + * is ranked. The callback is bound to `thisArg` and invoked with three + * arguments; (value, index, collection). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [callback=identity] The function called + * per iteration. If a property name or object is provided it will be used + * to create a "_.pluck" or "_.where" style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {*} Returns the maximum value. + * @example + * + * _.max([4, 2, 8, 6]); + * // => 8 + * + * var characters = [ + * { 'name': 'barney', 'age': 36 }, + * { 'name': 'fred', 'age': 40 } + * ]; + * + * _.max(characters, function(chr) { return chr.age; }); + * // => { 'name': 'fred', 'age': 40 }; + * + * // using "_.pluck" callback shorthand + * _.max(characters, 'age'); + * // => { 'name': 'fred', 'age': 40 }; + */ + function max(collection, callback, thisArg) { + var computed = -Infinity, + result = computed; + + // allows working with functions like `_.map` without using + // their `index` argument as a callback + if (typeof callback != 'function' && thisArg && thisArg[callback] === collection) { + callback = null; + } + var index = -1, + length = collection ? collection.length : 0; + + if (callback == null && typeof length == 'number') { + while (++index < length) { + var value = collection[index]; + if (value > result) { + result = value; + } + } + } else { + callback = createCallback(callback, thisArg, 3); + + forEach(collection, function(value, index, collection) { + var current = callback(value, index, collection); + if (current > computed) { + computed = current; + result = value; + } + }); + } + return result; + } + + /** + * Retrieves the minimum value of a collection. If the collection is empty or + * falsey `Infinity` is returned. If a callback is provided it will be executed + * for each value in the collection to generate the criterion by which the value + * is ranked. The callback is bound to `thisArg` and invoked with three + * arguments; (value, index, collection). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [callback=identity] The function called + * per iteration. If a property name or object is provided it will be used + * to create a "_.pluck" or "_.where" style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {*} Returns the minimum value. + * @example + * + * _.min([4, 2, 8, 6]); + * // => 2 + * + * var characters = [ + * { 'name': 'barney', 'age': 36 }, + * { 'name': 'fred', 'age': 40 } + * ]; + * + * _.min(characters, function(chr) { return chr.age; }); + * // => { 'name': 'barney', 'age': 36 }; + * + * // using "_.pluck" callback shorthand + * _.min(characters, 'age'); + * // => { 'name': 'barney', 'age': 36 }; + */ + function min(collection, callback, thisArg) { + var computed = Infinity, + result = computed; + + // allows working with functions like `_.map` without using + // their `index` argument as a callback + if (typeof callback != 'function' && thisArg && thisArg[callback] === collection) { + callback = null; + } + var index = -1, + length = collection ? collection.length : 0; + + if (callback == null && typeof length == 'number') { + while (++index < length) { + var value = collection[index]; + if (value < result) { + result = value; + } + } + } else { + callback = createCallback(callback, thisArg, 3); + + forEach(collection, function(value, index, collection) { + var current = callback(value, index, collection); + if (current < computed) { + computed = current; + result = value; + } + }); + } + return result; + } + + /** + * Retrieves the value of a specified property from all elements in the collection. + * + * @static + * @memberOf _ + * @type Function + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {string} property The name of the property to pluck. + * @returns {Array} Returns a new array of property values. + * @example + * + * var characters = [ + * { 'name': 'barney', 'age': 36 }, + * { 'name': 'fred', 'age': 40 } + * ]; + * + * _.pluck(characters, 'name'); + * // => ['barney', 'fred'] + */ + var pluck = map; + + /** + * Reduces a collection to a value which is the accumulated result of running + * each element in the collection through the callback, where each successive + * callback execution consumes the return value of the previous execution. If + * `accumulator` is not provided the first element of the collection will be + * used as the initial `accumulator` value. The callback is bound to `thisArg` + * and invoked with four arguments; (accumulator, value, index|key, collection). + * + * @static + * @memberOf _ + * @alias foldl, inject + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} [callback=identity] The function called per iteration. + * @param {*} [accumulator] Initial value of the accumulator. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {*} Returns the accumulated value. + * @example + * + * var sum = _.reduce([1, 2, 3], function(sum, num) { + * return sum + num; + * }); + * // => 6 + * + * var mapped = _.reduce({ 'a': 1, 'b': 2, 'c': 3 }, function(result, num, key) { + * result[key] = num * 3; + * return result; + * }, {}); + * // => { 'a': 3, 'b': 6, 'c': 9 } + */ + function reduce(collection, callback, accumulator, thisArg) { + if (!collection) return accumulator; + var noaccum = arguments.length < 3; + callback = createCallback(callback, thisArg, 4); + + var index = -1, + length = collection.length; + + if (typeof length == 'number') { + if (noaccum) { + accumulator = collection[++index]; + } + while (++index < length) { + accumulator = callback(accumulator, collection[index], index, collection); + } + } else { + forOwn(collection, function(value, index, collection) { + accumulator = noaccum + ? (noaccum = false, value) + : callback(accumulator, value, index, collection) + }); + } + return accumulator; + } + + /** + * This method is like `_.reduce` except that it iterates over elements + * of a `collection` from right to left. + * + * @static + * @memberOf _ + * @alias foldr + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} [callback=identity] The function called per iteration. + * @param {*} [accumulator] Initial value of the accumulator. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {*} Returns the accumulated value. + * @example + * + * var list = [[0, 1], [2, 3], [4, 5]]; + * var flat = _.reduceRight(list, function(a, b) { return a.concat(b); }, []); + * // => [4, 5, 2, 3, 0, 1] + */ + function reduceRight(collection, callback, accumulator, thisArg) { + var noaccum = arguments.length < 3; + callback = createCallback(callback, thisArg, 4); + forEachRight(collection, function(value, index, collection) { + accumulator = noaccum + ? (noaccum = false, value) + : callback(accumulator, value, index, collection); + }); + return accumulator; + } + + /** + * The opposite of `_.filter` this method returns the elements of a + * collection that the callback does **not** return truey for. + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [callback=identity] The function called + * per iteration. If a property name or object is provided it will be used + * to create a "_.pluck" or "_.where" style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Array} Returns a new array of elements that failed the callback check. + * @example + * + * var odds = _.reject([1, 2, 3, 4, 5, 6], function(num) { return num % 2 == 0; }); + * // => [1, 3, 5] + * + * var characters = [ + * { 'name': 'barney', 'age': 36, 'blocked': false }, + * { 'name': 'fred', 'age': 40, 'blocked': true } + * ]; + * + * // using "_.pluck" callback shorthand + * _.reject(characters, 'blocked'); + * // => [{ 'name': 'barney', 'age': 36, 'blocked': false }] + * + * // using "_.where" callback shorthand + * _.reject(characters, { 'age': 36 }); + * // => [{ 'name': 'fred', 'age': 40, 'blocked': true }] + */ + function reject(collection, callback, thisArg) { + callback = createCallback(callback, thisArg, 3); + return filter(collection, function(value, index, collection) { + return !callback(value, index, collection); + }); + } + + /** + * Retrieves a random element or `n` random elements from a collection. + * + * @static + * @memberOf _ + * @category Collections + * @param {Array|Object|string} collection The collection to sample. + * @param {number} [n] The number of elements to sample. + * @param- {Object} [guard] Allows working with functions like `_.map` + * without using their `index` arguments as `n`. + * @returns {Array} Returns the random sample(s) of `collection`. + * @example + * + * _.sample([1, 2, 3, 4]); + * // => 2 + * + * _.sample([1, 2, 3, 4], 2); + * // => [3, 1] + */ + function sample(collection, n, guard) { + if (collection && typeof collection.length != 'number') { + collection = values(collection); + } + if (n == null || guard) { + return collection ? collection[baseRandom(0, collection.length - 1)] : undefined; + } + var result = shuffle(collection); + result.length = nativeMin(nativeMax(0, n), result.length); + return result; + } + + /** + * Creates an array of shuffled values, using a version of the Fisher-Yates + * shuffle. See http://en.wikipedia.org/wiki/Fisher-Yates_shuffle. + * + * @static + * @memberOf _ + * @category Collections + * @param {Array|Object|string} collection The collection to shuffle. + * @returns {Array} Returns a new shuffled collection. + * @example + * + * _.shuffle([1, 2, 3, 4, 5, 6]); + * // => [4, 1, 6, 3, 5, 2] + */ + function shuffle(collection) { + var index = -1, + length = collection ? collection.length : 0, + result = Array(typeof length == 'number' ? length : 0); + + forEach(collection, function(value) { + var rand = baseRandom(0, ++index); + result[index] = result[rand]; + result[rand] = value; + }); + return result; + } + + /** + * Gets the size of the `collection` by returning `collection.length` for arrays + * and array-like objects or the number of own enumerable properties for objects. + * + * @static + * @memberOf _ + * @category Collections + * @param {Array|Object|string} collection The collection to inspect. + * @returns {number} Returns `collection.length` or number of own enumerable properties. + * @example + * + * _.size([1, 2]); + * // => 2 + * + * _.size({ 'one': 1, 'two': 2, 'three': 3 }); + * // => 3 + * + * _.size('pebbles'); + * // => 7 + */ + function size(collection) { + var length = collection ? collection.length : 0; + return typeof length == 'number' ? length : keys(collection).length; + } + + /** + * Checks if the callback returns a truey value for **any** element of a + * collection. The function returns as soon as it finds a passing value and + * does not iterate over the entire collection. The callback is bound to + * `thisArg` and invoked with three arguments; (value, index|key, collection). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @alias any + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [callback=identity] The function called + * per iteration. If a property name or object is provided it will be used + * to create a "_.pluck" or "_.where" style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {boolean} Returns `true` if any element passed the callback check, + * else `false`. + * @example + * + * _.some([null, 0, 'yes', false], Boolean); + * // => true + * + * var characters = [ + * { 'name': 'barney', 'age': 36, 'blocked': false }, + * { 'name': 'fred', 'age': 40, 'blocked': true } + * ]; + * + * // using "_.pluck" callback shorthand + * _.some(characters, 'blocked'); + * // => true + * + * // using "_.where" callback shorthand + * _.some(characters, { 'age': 1 }); + * // => false + */ + function some(collection, callback, thisArg) { + var result; + callback = createCallback(callback, thisArg, 3); + + var index = -1, + length = collection ? collection.length : 0; + + if (typeof length == 'number') { + while (++index < length) { + if ((result = callback(collection[index], index, collection))) { + break; + } + } + } else { + forOwn(collection, function(value, index, collection) { + return (result = callback(value, index, collection)) && indicatorObject; + }); + } + return !!result; + } + + /** + * Creates an array of elements, sorted in ascending order by the results of + * running each element in a collection through the callback. This method + * performs a stable sort, that is, it will preserve the original sort order + * of equal elements. The callback is bound to `thisArg` and invoked with + * three arguments; (value, index|key, collection). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an array of property names is provided for `callback` the collection + * will be sorted by each property value. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Array|Function|Object|string} [callback=identity] The function called + * per iteration. If a property name or object is provided it will be used + * to create a "_.pluck" or "_.where" style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Array} Returns a new array of sorted elements. + * @example + * + * _.sortBy([1, 2, 3], function(num) { return Math.sin(num); }); + * // => [3, 1, 2] + * + * _.sortBy([1, 2, 3], function(num) { return this.sin(num); }, Math); + * // => [3, 1, 2] + * + * var characters = [ + * { 'name': 'barney', 'age': 36 }, + * { 'name': 'fred', 'age': 40 }, + * { 'name': 'barney', 'age': 26 }, + * { 'name': 'fred', 'age': 30 } + * ]; + * + * // using "_.pluck" callback shorthand + * _.map(_.sortBy(characters, 'age'), _.values); + * // => [['barney', 26], ['fred', 30], ['barney', 36], ['fred', 40]] + * + * // sorting by multiple properties + * _.map(_.sortBy(characters, ['name', 'age']), _.values); + * // = > [['barney', 26], ['barney', 36], ['fred', 30], ['fred', 40]] + */ + function sortBy(collection, callback, thisArg) { + var index = -1, + length = collection ? collection.length : 0, + result = Array(typeof length == 'number' ? length : 0); + + callback = createCallback(callback, thisArg, 3); + forEach(collection, function(value, key, collection) { + result[++index] = { + 'criteria': [callback(value, key, collection)], + 'index': index, + 'value': value + }; + }); + + length = result.length; + result.sort(compareAscending); + while (length--) { + result[length] = result[length].value; + } + return result; + } + + /** + * Converts the `collection` to an array. + * + * @static + * @memberOf _ + * @category Collections + * @param {Array|Object|string} collection The collection to convert. + * @returns {Array} Returns the new converted array. + * @example + * + * (function() { return _.toArray(arguments).slice(1); })(1, 2, 3, 4); + * // => [2, 3, 4] + */ + function toArray(collection) { + if (isArray(collection)) { + return slice(collection); + } + if (collection && typeof collection.length == 'number') { + return map(collection); + } + return values(collection); + } + + /** + * Performs a deep comparison of each element in a `collection` to the given + * `properties` object, returning an array of all elements that have equivalent + * property values. + * + * @static + * @memberOf _ + * @type Function + * @category Collections + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Object} props The object of property values to filter by. + * @returns {Array} Returns a new array of elements that have the given properties. + * @example + * + * var characters = [ + * { 'name': 'barney', 'age': 36, 'pets': ['hoppy'] }, + * { 'name': 'fred', 'age': 40, 'pets': ['baby puss', 'dino'] } + * ]; + * + * _.where(characters, { 'age': 36 }); + * // => [{ 'name': 'barney', 'age': 36, 'pets': ['hoppy'] }] + * + * _.where(characters, { 'pets': ['dino'] }); + * // => [{ 'name': 'fred', 'age': 40, 'pets': ['baby puss', 'dino'] }] + */ + function where(collection, properties, first) { + return (first && isEmpty(properties)) + ? undefined + : (first ? find : filter)(collection, properties); + } + + /*--------------------------------------------------------------------------*/ + + /** + * Creates an array with all falsey values removed. The values `false`, `null`, + * `0`, `""`, `undefined`, and `NaN` are all falsey. + * + * @static + * @memberOf _ + * @category Arrays + * @param {Array} array The array to compact. + * @returns {Array} Returns a new array of filtered values. + * @example + * + * _.compact([0, 1, false, 2, '', 3]); + * // => [1, 2, 3] + */ + function compact(array) { + var index = -1, + length = array ? array.length : 0, + result = []; + + while (++index < length) { + var value = array[index]; + if (value) { + result.push(value); + } + } + return result; + } + + /** + * Creates an array excluding all values of the provided arrays using strict + * equality for comparisons, i.e. `===`. + * + * @static + * @memberOf _ + * @category Arrays + * @param {Array} array The array to process. + * @param {...Array} [values] The arrays of values to exclude. + * @returns {Array} Returns a new array of filtered values. + * @example + * + * _.difference([1, 2, 3, 4, 5], [5, 2, 10]); + * // => [1, 3, 4] + */ + function difference(array) { + return baseDifference(array, baseFlatten(arguments, true, true, 1)); + } + + /** + * Gets the first element or first `n` elements of an array. If a callback + * is provided elements at the beginning of the array are returned as long + * as the callback returns truey. The callback is bound to `thisArg` and + * invoked with three arguments; (value, index, array). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @alias head, take + * @category Arrays + * @param {Array} array The array to query. + * @param {Function|Object|number|string} [callback] The function called + * per element or the number of elements to return. If a property name or + * object is provided it will be used to create a "_.pluck" or "_.where" + * style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {*} Returns the first element(s) of `array`. + * @example + * + * _.first([1, 2, 3]); + * // => 1 + * + * _.first([1, 2, 3], 2); + * // => [1, 2] + * + * _.first([1, 2, 3], function(num) { + * return num < 3; + * }); + * // => [1, 2] + * + * var characters = [ + * { 'name': 'barney', 'blocked': true, 'employer': 'slate' }, + * { 'name': 'fred', 'blocked': false, 'employer': 'slate' }, + * { 'name': 'pebbles', 'blocked': true, 'employer': 'na' } + * ]; + * + * // using "_.pluck" callback shorthand + * _.first(characters, 'blocked'); + * // => [{ 'name': 'barney', 'blocked': true, 'employer': 'slate' }] + * + * // using "_.where" callback shorthand + * _.pluck(_.first(characters, { 'employer': 'slate' }), 'name'); + * // => ['barney', 'fred'] + */ + function first(array, callback, thisArg) { + var n = 0, + length = array ? array.length : 0; + + if (typeof callback != 'number' && callback != null) { + var index = -1; + callback = createCallback(callback, thisArg, 3); + while (++index < length && callback(array[index], index, array)) { + n++; + } + } else { + n = callback; + if (n == null || thisArg) { + return array ? array[0] : undefined; + } + } + return slice(array, 0, nativeMin(nativeMax(0, n), length)); + } + + /** + * Flattens a nested array (the nesting can be to any depth). If `isShallow` + * is truey, the array will only be flattened a single level. If a callback + * is provided each element of the array is passed through the callback before + * flattening. The callback is bound to `thisArg` and invoked with three + * arguments; (value, index, array). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @category Arrays + * @param {Array} array The array to flatten. + * @param {boolean} [isShallow=false] A flag to restrict flattening to a single level. + * @param {Function|Object|string} [callback=identity] The function called + * per iteration. If a property name or object is provided it will be used + * to create a "_.pluck" or "_.where" style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Array} Returns a new flattened array. + * @example + * + * _.flatten([1, [2], [3, [[4]]]]); + * // => [1, 2, 3, 4]; + * + * _.flatten([1, [2], [3, [[4]]]], true); + * // => [1, 2, 3, [[4]]]; + * + * var characters = [ + * { 'name': 'barney', 'age': 30, 'pets': ['hoppy'] }, + * { 'name': 'fred', 'age': 40, 'pets': ['baby puss', 'dino'] } + * ]; + * + * // using "_.pluck" callback shorthand + * _.flatten(characters, 'pets'); + * // => ['hoppy', 'baby puss', 'dino'] + */ + function flatten(array, isShallow) { + return baseFlatten(array, isShallow); + } + + /** + * Gets the index at which the first occurrence of `value` is found using + * strict equality for comparisons, i.e. `===`. If the array is already sorted + * providing `true` for `fromIndex` will run a faster binary search. + * + * @static + * @memberOf _ + * @category Arrays + * @param {Array} array The array to search. + * @param {*} value The value to search for. + * @param {boolean|number} [fromIndex=0] The index to search from or `true` + * to perform a binary search on a sorted array. + * @returns {number} Returns the index of the matched value or `-1`. + * @example + * + * _.indexOf([1, 2, 3, 1, 2, 3], 2); + * // => 1 + * + * _.indexOf([1, 2, 3, 1, 2, 3], 2, 3); + * // => 4 + * + * _.indexOf([1, 1, 2, 2, 3, 3], 2, true); + * // => 2 + */ + function indexOf(array, value, fromIndex) { + if (typeof fromIndex == 'number') { + var length = array ? array.length : 0; + fromIndex = (fromIndex < 0 ? nativeMax(0, length + fromIndex) : fromIndex || 0); + } else if (fromIndex) { + var index = sortedIndex(array, value); + return array[index] === value ? index : -1; + } + return baseIndexOf(array, value, fromIndex); + } + + /** + * Gets all but the last element or last `n` elements of an array. If a + * callback is provided elements at the end of the array are excluded from + * the result as long as the callback returns truey. The callback is bound + * to `thisArg` and invoked with three arguments; (value, index, array). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @category Arrays + * @param {Array} array The array to query. + * @param {Function|Object|number|string} [callback=1] The function called + * per element or the number of elements to exclude. If a property name or + * object is provided it will be used to create a "_.pluck" or "_.where" + * style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Array} Returns a slice of `array`. + * @example + * + * _.initial([1, 2, 3]); + * // => [1, 2] + * + * _.initial([1, 2, 3], 2); + * // => [1] + * + * _.initial([1, 2, 3], function(num) { + * return num > 1; + * }); + * // => [1] + * + * var characters = [ + * { 'name': 'barney', 'blocked': false, 'employer': 'slate' }, + * { 'name': 'fred', 'blocked': true, 'employer': 'slate' }, + * { 'name': 'pebbles', 'blocked': true, 'employer': 'na' } + * ]; + * + * // using "_.pluck" callback shorthand + * _.initial(characters, 'blocked'); + * // => [{ 'name': 'barney', 'blocked': false, 'employer': 'slate' }] + * + * // using "_.where" callback shorthand + * _.pluck(_.initial(characters, { 'employer': 'na' }), 'name'); + * // => ['barney', 'fred'] + */ + function initial(array, callback, thisArg) { + var n = 0, + length = array ? array.length : 0; + + if (typeof callback != 'number' && callback != null) { + var index = length; + callback = createCallback(callback, thisArg, 3); + while (index-- && callback(array[index], index, array)) { + n++; + } + } else { + n = (callback == null || thisArg) ? 1 : callback || n; + } + return slice(array, 0, nativeMin(nativeMax(0, length - n), length)); + } + + /** + * Creates an array of unique values present in all provided arrays using + * strict equality for comparisons, i.e. `===`. + * + * @static + * @memberOf _ + * @category Arrays + * @param {...Array} [array] The arrays to inspect. + * @returns {Array} Returns an array of shared values. + * @example + * + * _.intersection([1, 2, 3], [5, 2, 1, 4], [2, 1]); + * // => [1, 2] + */ + function intersection() { + var args = [], + argsIndex = -1, + argsLength = arguments.length; + + while (++argsIndex < argsLength) { + var value = arguments[argsIndex]; + if (isArray(value) || isArguments(value)) { + args.push(value); + } + } + var array = args[0], + index = -1, + indexOf = getIndexOf(), + length = array ? array.length : 0, + result = []; + + outer: + while (++index < length) { + value = array[index]; + if (indexOf(result, value) < 0) { + var argsIndex = argsLength; + while (--argsIndex) { + if (indexOf(args[argsIndex], value) < 0) { + continue outer; + } + } + result.push(value); + } + } + return result; + } + + /** + * Gets the last element or last `n` elements of an array. If a callback is + * provided elements at the end of the array are returned as long as the + * callback returns truey. The callback is bound to `thisArg` and invoked + * with three arguments; (value, index, array). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @category Arrays + * @param {Array} array The array to query. + * @param {Function|Object|number|string} [callback] The function called + * per element or the number of elements to return. If a property name or + * object is provided it will be used to create a "_.pluck" or "_.where" + * style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {*} Returns the last element(s) of `array`. + * @example + * + * _.last([1, 2, 3]); + * // => 3 + * + * _.last([1, 2, 3], 2); + * // => [2, 3] + * + * _.last([1, 2, 3], function(num) { + * return num > 1; + * }); + * // => [2, 3] + * + * var characters = [ + * { 'name': 'barney', 'blocked': false, 'employer': 'slate' }, + * { 'name': 'fred', 'blocked': true, 'employer': 'slate' }, + * { 'name': 'pebbles', 'blocked': true, 'employer': 'na' } + * ]; + * + * // using "_.pluck" callback shorthand + * _.pluck(_.last(characters, 'blocked'), 'name'); + * // => ['fred', 'pebbles'] + * + * // using "_.where" callback shorthand + * _.last(characters, { 'employer': 'na' }); + * // => [{ 'name': 'pebbles', 'blocked': true, 'employer': 'na' }] + */ + function last(array, callback, thisArg) { + var n = 0, + length = array ? array.length : 0; + + if (typeof callback != 'number' && callback != null) { + var index = length; + callback = createCallback(callback, thisArg, 3); + while (index-- && callback(array[index], index, array)) { + n++; + } + } else { + n = callback; + if (n == null || thisArg) { + return array ? array[length - 1] : undefined; + } + } + return slice(array, nativeMax(0, length - n)); + } + + /** + * Gets the index at which the last occurrence of `value` is found using strict + * equality for comparisons, i.e. `===`. If `fromIndex` is negative, it is used + * as the offset from the end of the collection. + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @category Arrays + * @param {Array} array The array to search. + * @param {*} value The value to search for. + * @param {number} [fromIndex=array.length-1] The index to search from. + * @returns {number} Returns the index of the matched value or `-1`. + * @example + * + * _.lastIndexOf([1, 2, 3, 1, 2, 3], 2); + * // => 4 + * + * _.lastIndexOf([1, 2, 3, 1, 2, 3], 2, 3); + * // => 1 + */ + function lastIndexOf(array, value, fromIndex) { + var index = array ? array.length : 0; + if (typeof fromIndex == 'number') { + index = (fromIndex < 0 ? nativeMax(0, index + fromIndex) : nativeMin(fromIndex, index - 1)) + 1; + } + while (index--) { + if (array[index] === value) { + return index; + } + } + return -1; + } + + /** + * Creates an array of numbers (positive and/or negative) progressing from + * `start` up to but not including `end`. If `start` is less than `stop` a + * zero-length range is created unless a negative `step` is specified. + * + * @static + * @memberOf _ + * @category Arrays + * @param {number} [start=0] The start of the range. + * @param {number} end The end of the range. + * @param {number} [step=1] The value to increment or decrement by. + * @returns {Array} Returns a new range array. + * @example + * + * _.range(4); + * // => [0, 1, 2, 3] + * + * _.range(1, 5); + * // => [1, 2, 3, 4] + * + * _.range(0, 20, 5); + * // => [0, 5, 10, 15] + * + * _.range(0, -4, -1); + * // => [0, -1, -2, -3] + * + * _.range(1, 4, 0); + * // => [1, 1, 1] + * + * _.range(0); + * // => [] + */ + function range(start, end, step) { + start = +start || 0; + step = (+step || 1); + + if (end == null) { + end = start; + start = 0; + } + // use `Array(length)` so engines like Chakra and V8 avoid slower modes + // http://youtu.be/XAqIpGU8ZZk#t=17m25s + var index = -1, + length = nativeMax(0, ceil((end - start) / step)), + result = Array(length); + + while (++index < length) { + result[index] = start; + start += step; + } + return result; + } + + /** + * The opposite of `_.initial` this method gets all but the first element or + * first `n` elements of an array. If a callback function is provided elements + * at the beginning of the array are excluded from the result as long as the + * callback returns truey. The callback is bound to `thisArg` and invoked + * with three arguments; (value, index, array). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @alias drop, tail + * @category Arrays + * @param {Array} array The array to query. + * @param {Function|Object|number|string} [callback=1] The function called + * per element or the number of elements to exclude. If a property name or + * object is provided it will be used to create a "_.pluck" or "_.where" + * style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Array} Returns a slice of `array`. + * @example + * + * _.rest([1, 2, 3]); + * // => [2, 3] + * + * _.rest([1, 2, 3], 2); + * // => [3] + * + * _.rest([1, 2, 3], function(num) { + * return num < 3; + * }); + * // => [3] + * + * var characters = [ + * { 'name': 'barney', 'blocked': true, 'employer': 'slate' }, + * { 'name': 'fred', 'blocked': false, 'employer': 'slate' }, + * { 'name': 'pebbles', 'blocked': true, 'employer': 'na' } + * ]; + * + * // using "_.pluck" callback shorthand + * _.pluck(_.rest(characters, 'blocked'), 'name'); + * // => ['fred', 'pebbles'] + * + * // using "_.where" callback shorthand + * _.rest(characters, { 'employer': 'slate' }); + * // => [{ 'name': 'pebbles', 'blocked': true, 'employer': 'na' }] + */ + function rest(array, callback, thisArg) { + if (typeof callback != 'number' && callback != null) { + var n = 0, + index = -1, + length = array ? array.length : 0; + + callback = createCallback(callback, thisArg, 3); + while (++index < length && callback(array[index], index, array)) { + n++; + } + } else { + n = (callback == null || thisArg) ? 1 : nativeMax(0, callback); + } + return slice(array, n); + } + + /** + * Uses a binary search to determine the smallest index at which a value + * should be inserted into a given sorted array in order to maintain the sort + * order of the array. If a callback is provided it will be executed for + * `value` and each element of `array` to compute their sort ranking. The + * callback is bound to `thisArg` and invoked with one argument; (value). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @category Arrays + * @param {Array} array The array to inspect. + * @param {*} value The value to evaluate. + * @param {Function|Object|string} [callback=identity] The function called + * per iteration. If a property name or object is provided it will be used + * to create a "_.pluck" or "_.where" style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {number} Returns the index at which `value` should be inserted + * into `array`. + * @example + * + * _.sortedIndex([20, 30, 50], 40); + * // => 2 + * + * // using "_.pluck" callback shorthand + * _.sortedIndex([{ 'x': 20 }, { 'x': 30 }, { 'x': 50 }], { 'x': 40 }, 'x'); + * // => 2 + * + * var dict = { + * 'wordToNumber': { 'twenty': 20, 'thirty': 30, 'fourty': 40, 'fifty': 50 } + * }; + * + * _.sortedIndex(['twenty', 'thirty', 'fifty'], 'fourty', function(word) { + * return dict.wordToNumber[word]; + * }); + * // => 2 + * + * _.sortedIndex(['twenty', 'thirty', 'fifty'], 'fourty', function(word) { + * return this.wordToNumber[word]; + * }, dict); + * // => 2 + */ + function sortedIndex(array, value, callback, thisArg) { + var low = 0, + high = array ? array.length : low; + + // explicitly reference `identity` for better inlining in Firefox + callback = callback ? createCallback(callback, thisArg, 1) : identity; + value = callback(value); + + while (low < high) { + var mid = (low + high) >>> 1; + (callback(array[mid]) < value) + ? low = mid + 1 + : high = mid; + } + return low; + } + + /** + * Creates an array of unique values, in order, of the provided arrays using + * strict equality for comparisons, i.e. `===`. + * + * @static + * @memberOf _ + * @category Arrays + * @param {...Array} [array] The arrays to inspect. + * @returns {Array} Returns an array of combined values. + * @example + * + * _.union([1, 2, 3], [5, 2, 1, 4], [2, 1]); + * // => [1, 2, 3, 5, 4] + */ + function union() { + return baseUniq(baseFlatten(arguments, true, true)); + } + + /** + * Creates a duplicate-value-free version of an array using strict equality + * for comparisons, i.e. `===`. If the array is sorted, providing + * `true` for `isSorted` will use a faster algorithm. If a callback is provided + * each element of `array` is passed through the callback before uniqueness + * is computed. The callback is bound to `thisArg` and invoked with three + * arguments; (value, index, array). + * + * If a property name is provided for `callback` the created "_.pluck" style + * callback will return the property value of the given element. + * + * If an object is provided for `callback` the created "_.where" style callback + * will return `true` for elements that have the properties of the given object, + * else `false`. + * + * @static + * @memberOf _ + * @alias unique + * @category Arrays + * @param {Array} array The array to process. + * @param {boolean} [isSorted=false] A flag to indicate that `array` is sorted. + * @param {Function|Object|string} [callback=identity] The function called + * per iteration. If a property name or object is provided it will be used + * to create a "_.pluck" or "_.where" style callback, respectively. + * @param {*} [thisArg] The `this` binding of `callback`. + * @returns {Array} Returns a duplicate-value-free array. + * @example + * + * _.uniq([1, 2, 1, 3, 1]); + * // => [1, 2, 3] + * + * _.uniq([1, 1, 2, 2, 3], true); + * // => [1, 2, 3] + * + * _.uniq(['A', 'b', 'C', 'a', 'B', 'c'], function(letter) { return letter.toLowerCase(); }); + * // => ['A', 'b', 'C'] + * + * _.uniq([1, 2.5, 3, 1.5, 2, 3.5], function(num) { return this.floor(num); }, Math); + * // => [1, 2.5, 3] + * + * // using "_.pluck" callback shorthand + * _.uniq([{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }], 'x'); + * // => [{ 'x': 1 }, { 'x': 2 }] + */ + function uniq(array, isSorted, callback, thisArg) { + // juggle arguments + if (typeof isSorted != 'boolean' && isSorted != null) { + thisArg = callback; + callback = (typeof isSorted != 'function' && thisArg && thisArg[isSorted] === array) ? null : isSorted; + isSorted = false; + } + if (callback != null) { + callback = createCallback(callback, thisArg, 3); + } + return baseUniq(array, isSorted, callback); + } + + /** + * Creates an array excluding all provided values using strict equality for + * comparisons, i.e. `===`. + * + * @static + * @memberOf _ + * @category Arrays + * @param {Array} array The array to filter. + * @param {...*} [value] The values to exclude. + * @returns {Array} Returns a new array of filtered values. + * @example + * + * _.without([1, 2, 1, 0, 3, 1, 4], 0, 1); + * // => [2, 3, 4] + */ + function without(array) { + return baseDifference(array, slice(arguments, 1)); + } + + /** + * Creates an array of grouped elements, the first of which contains the first + * elements of the given arrays, the second of which contains the second + * elements of the given arrays, and so on. + * + * @static + * @memberOf _ + * @alias unzip + * @category Arrays + * @param {...Array} [array] Arrays to process. + * @returns {Array} Returns a new array of grouped elements. + * @example + * + * _.zip(['fred', 'barney'], [30, 40], [true, false]); + * // => [['fred', 30, true], ['barney', 40, false]] + */ + function zip() { + var index = -1, + length = max(pluck(arguments, 'length')), + result = Array(length < 0 ? 0 : length); + + while (++index < length) { + result[index] = pluck(arguments, index); + } + return result; + } + + /** + * Creates an object composed from arrays of `keys` and `values`. Provide + * either a single two dimensional array, i.e. `[[key1, value1], [key2, value2]]` + * or two arrays, one of `keys` and one of corresponding `values`. + * + * @static + * @memberOf _ + * @alias object + * @category Arrays + * @param {Array} keys The array of keys. + * @param {Array} [values=[]] The array of values. + * @returns {Object} Returns an object composed of the given keys and + * corresponding values. + * @example + * + * _.zipObject(['fred', 'barney'], [30, 40]); + * // => { 'fred': 30, 'barney': 40 } + */ + function zipObject(keys, values) { + var index = -1, + length = keys ? keys.length : 0, + result = {}; + + if (!values && length && !isArray(keys[0])) { + values = []; + } + while (++index < length) { + var key = keys[index]; + if (values) { + result[key] = values[index]; + } else if (key) { + result[key[0]] = key[1]; + } + } + return result; + } + + /*--------------------------------------------------------------------------*/ + + /** + * Creates a function that executes `func`, with the `this` binding and + * arguments of the created function, only after being called `n` times. + * + * @static + * @memberOf _ + * @category Functions + * @param {number} n The number of times the function must be called before + * `func` is executed. + * @param {Function} func The function to restrict. + * @returns {Function} Returns the new restricted function. + * @example + * + * var saves = ['profile', 'settings']; + * + * var done = _.after(saves.length, function() { + * console.log('Done saving!'); + * }); + * + * _.forEach(saves, function(type) { + * asyncSave({ 'type': type, 'complete': done }); + * }); + * // => logs 'Done saving!', after all saves have completed + */ + function after(n, func) { + if (!isFunction(func)) { + throw new TypeError; + } + return function() { + if (--n < 1) { + return func.apply(this, arguments); + } + }; + } + + /** + * Creates a function that, when called, invokes `func` with the `this` + * binding of `thisArg` and prepends any additional `bind` arguments to those + * provided to the bound function. + * + * @static + * @memberOf _ + * @category Functions + * @param {Function} func The function to bind. + * @param {*} [thisArg] The `this` binding of `func`. + * @param {...*} [arg] Arguments to be partially applied. + * @returns {Function} Returns the new bound function. + * @example + * + * var func = function(greeting) { + * return greeting + ' ' + this.name; + * }; + * + * func = _.bind(func, { 'name': 'fred' }, 'hi'); + * func(); + * // => 'hi fred' + */ + function bind(func, thisArg) { + return arguments.length > 2 + ? createWrapper(func, 17, slice(arguments, 2), null, thisArg) + : createWrapper(func, 1, null, null, thisArg); + } + + /** + * Binds methods of an object to the object itself, overwriting the existing + * method. Method names may be specified as individual arguments or as arrays + * of method names. If no method names are provided all the function properties + * of `object` will be bound. + * + * @static + * @memberOf _ + * @category Functions + * @param {Object} object The object to bind and assign the bound methods to. + * @param {...string} [methodName] The object method names to + * bind, specified as individual method names or arrays of method names. + * @returns {Object} Returns `object`. + * @example + * + * var view = { + * 'label': 'docs', + * 'onClick': function() { console.log('clicked ' + this.label); } + * }; + * + * _.bindAll(view); + * jQuery('#docs').on('click', view.onClick); + * // => logs 'clicked docs', when the button is clicked + */ + function bindAll(object) { + var funcs = arguments.length > 1 ? baseFlatten(arguments, true, false, 1) : functions(object), + index = -1, + length = funcs.length; + + while (++index < length) { + var key = funcs[index]; + object[key] = createWrapper(object[key], 1, null, null, object); + } + return object; + } + + /** + * Creates a function that is the composition of the provided functions, + * where each function consumes the return value of the function that follows. + * For example, composing the functions `f()`, `g()`, and `h()` produces `f(g(h()))`. + * Each function is executed with the `this` binding of the composed function. + * + * @static + * @memberOf _ + * @category Functions + * @param {...Function} [func] Functions to compose. + * @returns {Function} Returns the new composed function. + * @example + * + * var realNameMap = { + * 'pebbles': 'penelope' + * }; + * + * var format = function(name) { + * name = realNameMap[name.toLowerCase()] || name; + * return name.charAt(0).toUpperCase() + name.slice(1).toLowerCase(); + * }; + * + * var greet = function(formatted) { + * return 'Hiya ' + formatted + '!'; + * }; + * + * var welcome = _.compose(greet, format); + * welcome('pebbles'); + * // => 'Hiya Penelope!' + */ + function compose() { + var funcs = arguments, + length = funcs.length; + + while (length--) { + if (!isFunction(funcs[length])) { + throw new TypeError; + } + } + return function() { + var args = arguments, + length = funcs.length; + + while (length--) { + args = [funcs[length].apply(this, args)]; + } + return args[0]; + }; + } + + /** + * Creates a function that will delay the execution of `func` until after + * `wait` milliseconds have elapsed since the last time it was invoked. + * Provide an options object to indicate that `func` should be invoked on + * the leading and/or trailing edge of the `wait` timeout. Subsequent calls + * to the debounced function will return the result of the last `func` call. + * + * Note: If `leading` and `trailing` options are `true` `func` will be called + * on the trailing edge of the timeout only if the the debounced function is + * invoked more than once during the `wait` timeout. + * + * @static + * @memberOf _ + * @category Functions + * @param {Function} func The function to debounce. + * @param {number} wait The number of milliseconds to delay. + * @param {Object} [options] The options object. + * @param {boolean} [options.leading=false] Specify execution on the leading edge of the timeout. + * @param {number} [options.maxWait] The maximum time `func` is allowed to be delayed before it's called. + * @param {boolean} [options.trailing=true] Specify execution on the trailing edge of the timeout. + * @returns {Function} Returns the new debounced function. + * @example + * + * // avoid costly calculations while the window size is in flux + * var lazyLayout = _.debounce(calculateLayout, 150); + * jQuery(window).on('resize', lazyLayout); + * + * // execute `sendMail` when the click event is fired, debouncing subsequent calls + * jQuery('#postbox').on('click', _.debounce(sendMail, 300, { + * 'leading': true, + * 'trailing': false + * }); + * + * // ensure `batchLog` is executed once after 1 second of debounced calls + * var source = new EventSource('/stream'); + * source.addEventListener('message', _.debounce(batchLog, 250, { + * 'maxWait': 1000 + * }, false); + */ + function debounce(func, wait, options) { + var args, + maxTimeoutId, + result, + stamp, + thisArg, + timeoutId, + trailingCall, + lastCalled = 0, + maxWait = false, + trailing = true; + + if (!isFunction(func)) { + throw new TypeError; + } + wait = nativeMax(0, wait) || 0; + if (options === true) { + var leading = true; + trailing = false; + } else if (isObject(options)) { + leading = options.leading; + maxWait = 'maxWait' in options && (nativeMax(wait, options.maxWait) || 0); + trailing = 'trailing' in options ? options.trailing : trailing; + } + var delayed = function() { + var remaining = wait - (now() - stamp); + if (remaining <= 0) { + if (maxTimeoutId) { + clearTimeout(maxTimeoutId); + } + var isCalled = trailingCall; + maxTimeoutId = timeoutId = trailingCall = undefined; + if (isCalled) { + lastCalled = now(); + result = func.apply(thisArg, args); + if (!timeoutId && !maxTimeoutId) { + args = thisArg = null; + } + } + } else { + timeoutId = setTimeout(delayed, remaining); + } + }; + + var maxDelayed = function() { + if (timeoutId) { + clearTimeout(timeoutId); + } + maxTimeoutId = timeoutId = trailingCall = undefined; + if (trailing || (maxWait !== wait)) { + lastCalled = now(); + result = func.apply(thisArg, args); + if (!timeoutId && !maxTimeoutId) { + args = thisArg = null; + } + } + }; + + return function() { + args = arguments; + stamp = now(); + thisArg = this; + trailingCall = trailing && (timeoutId || !leading); + + if (maxWait === false) { + var leadingCall = leading && !timeoutId; + } else { + if (!maxTimeoutId && !leading) { + lastCalled = stamp; + } + var remaining = maxWait - (stamp - lastCalled), + isCalled = remaining <= 0; + + if (isCalled) { + if (maxTimeoutId) { + maxTimeoutId = clearTimeout(maxTimeoutId); + } + lastCalled = stamp; + result = func.apply(thisArg, args); + } + else if (!maxTimeoutId) { + maxTimeoutId = setTimeout(maxDelayed, remaining); + } + } + if (isCalled && timeoutId) { + timeoutId = clearTimeout(timeoutId); + } + else if (!timeoutId && wait !== maxWait) { + timeoutId = setTimeout(delayed, wait); + } + if (leadingCall) { + isCalled = true; + result = func.apply(thisArg, args); + } + if (isCalled && !timeoutId && !maxTimeoutId) { + args = thisArg = null; + } + return result; + }; + } + + /** + * Defers executing the `func` function until the current call stack has cleared. + * Additional arguments will be provided to `func` when it is invoked. + * + * @static + * @memberOf _ + * @category Functions + * @param {Function} func The function to defer. + * @param {...*} [arg] Arguments to invoke the function with. + * @returns {number} Returns the timer id. + * @example + * + * _.defer(function(text) { console.log(text); }, 'deferred'); + * // logs 'deferred' after one or more milliseconds + */ + function defer(func) { + if (!isFunction(func)) { + throw new TypeError; + } + var args = slice(arguments, 1); + return setTimeout(function() { func.apply(undefined, args); }, 1); + } + + /** + * Executes the `func` function after `wait` milliseconds. Additional arguments + * will be provided to `func` when it is invoked. + * + * @static + * @memberOf _ + * @category Functions + * @param {Function} func The function to delay. + * @param {number} wait The number of milliseconds to delay execution. + * @param {...*} [arg] Arguments to invoke the function with. + * @returns {number} Returns the timer id. + * @example + * + * _.delay(function(text) { console.log(text); }, 1000, 'later'); + * // => logs 'later' after one second + */ + function delay(func, wait) { + if (!isFunction(func)) { + throw new TypeError; + } + var args = slice(arguments, 2); + return setTimeout(function() { func.apply(undefined, args); }, wait); + } + + /** + * Creates a function that memoizes the result of `func`. If `resolver` is + * provided it will be used to determine the cache key for storing the result + * based on the arguments provided to the memoized function. By default, the + * first argument provided to the memoized function is used as the cache key. + * The `func` is executed with the `this` binding of the memoized function. + * The result cache is exposed as the `cache` property on the memoized function. + * + * @static + * @memberOf _ + * @category Functions + * @param {Function} func The function to have its output memoized. + * @param {Function} [resolver] A function used to resolve the cache key. + * @returns {Function} Returns the new memoizing function. + * @example + * + * var fibonacci = _.memoize(function(n) { + * return n < 2 ? n : fibonacci(n - 1) + fibonacci(n - 2); + * }); + * + * fibonacci(9) + * // => 34 + * + * var data = { + * 'fred': { 'name': 'fred', 'age': 40 }, + * 'pebbles': { 'name': 'pebbles', 'age': 1 } + * }; + * + * // modifying the result cache + * var get = _.memoize(function(name) { return data[name]; }, _.identity); + * get('pebbles'); + * // => { 'name': 'pebbles', 'age': 1 } + * + * get.cache.pebbles.name = 'penelope'; + * get('pebbles'); + * // => { 'name': 'penelope', 'age': 1 } + */ + function memoize(func, resolver) { + var cache = {}; + return function() { + var key = resolver ? resolver.apply(this, arguments) : keyPrefix + arguments[0]; + return hasOwnProperty.call(cache, key) + ? cache[key] + : (cache[key] = func.apply(this, arguments)); + }; + } + + /** + * Creates a function that is restricted to execute `func` once. Repeat calls to + * the function will return the value of the first call. The `func` is executed + * with the `this` binding of the created function. + * + * @static + * @memberOf _ + * @category Functions + * @param {Function} func The function to restrict. + * @returns {Function} Returns the new restricted function. + * @example + * + * var initialize = _.once(createApplication); + * initialize(); + * initialize(); + * // `initialize` executes `createApplication` once + */ + function once(func) { + var ran, + result; + + if (!isFunction(func)) { + throw new TypeError; + } + return function() { + if (ran) { + return result; + } + ran = true; + result = func.apply(this, arguments); + + // clear the `func` variable so the function may be garbage collected + func = null; + return result; + }; + } + + /** + * Creates a function that, when called, invokes `func` with any additional + * `partial` arguments prepended to those provided to the new function. This + * method is similar to `_.bind` except it does **not** alter the `this` binding. + * + * @static + * @memberOf _ + * @category Functions + * @param {Function} func The function to partially apply arguments to. + * @param {...*} [arg] Arguments to be partially applied. + * @returns {Function} Returns the new partially applied function. + * @example + * + * var greet = function(greeting, name) { return greeting + ' ' + name; }; + * var hi = _.partial(greet, 'hi'); + * hi('fred'); + * // => 'hi fred' + */ + function partial(func) { + return createWrapper(func, 16, slice(arguments, 1)); + } + + /** + * Creates a function that, when executed, will only call the `func` function + * at most once per every `wait` milliseconds. Provide an options object to + * indicate that `func` should be invoked on the leading and/or trailing edge + * of the `wait` timeout. Subsequent calls to the throttled function will + * return the result of the last `func` call. + * + * Note: If `leading` and `trailing` options are `true` `func` will be called + * on the trailing edge of the timeout only if the the throttled function is + * invoked more than once during the `wait` timeout. + * + * @static + * @memberOf _ + * @category Functions + * @param {Function} func The function to throttle. + * @param {number} wait The number of milliseconds to throttle executions to. + * @param {Object} [options] The options object. + * @param {boolean} [options.leading=true] Specify execution on the leading edge of the timeout. + * @param {boolean} [options.trailing=true] Specify execution on the trailing edge of the timeout. + * @returns {Function} Returns the new throttled function. + * @example + * + * // avoid excessively updating the position while scrolling + * var throttled = _.throttle(updatePosition, 100); + * jQuery(window).on('scroll', throttled); + * + * // execute `renewToken` when the click event is fired, but not more than once every 5 minutes + * jQuery('.interactive').on('click', _.throttle(renewToken, 300000, { + * 'trailing': false + * })); + */ + function throttle(func, wait, options) { + var leading = true, + trailing = true; + + if (!isFunction(func)) { + throw new TypeError; + } + if (options === false) { + leading = false; + } else if (isObject(options)) { + leading = 'leading' in options ? options.leading : leading; + trailing = 'trailing' in options ? options.trailing : trailing; + } + options = {}; + options.leading = leading; + options.maxWait = wait; + options.trailing = trailing; + + return debounce(func, wait, options); + } + + /** + * Creates a function that provides `value` to the wrapper function as its + * first argument. Additional arguments provided to the function are appended + * to those provided to the wrapper function. The wrapper is executed with + * the `this` binding of the created function. + * + * @static + * @memberOf _ + * @category Functions + * @param {*} value The value to wrap. + * @param {Function} wrapper The wrapper function. + * @returns {Function} Returns the new function. + * @example + * + * var p = _.wrap(_.escape, function(func, text) { + * return '

' + func(text) + '

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

Fred, Wilma, & Pebbles

' + */ + function wrap(value, wrapper) { + return createWrapper(wrapper, 16, [value]); + } + + /*--------------------------------------------------------------------------*/ + + /** + * Produces a callback bound to an optional `thisArg`. If `func` is a property + * name the created callback will return the property value for a given element. + * If `func` is an object the created callback will return `true` for elements + * that contain the equivalent object properties, otherwise it will return `false`. + * + * @static + * @memberOf _ + * @category Utilities + * @param {*} [func=identity] The value to convert to a callback. + * @param {*} [thisArg] The `this` binding of the created callback. + * @param {number} [argCount] The number of arguments the callback accepts. + * @returns {Function} Returns a callback function. + * @example + * + * var characters = [ + * { 'name': 'barney', 'age': 36 }, + * { 'name': 'fred', 'age': 40 } + * ]; + * + * // wrap to create custom callback shorthands + * _.createCallback = _.wrap(_.createCallback, function(func, callback, thisArg) { + * var match = /^(.+?)__([gl]t)(.+)$/.exec(callback); + * return !match ? func(callback, thisArg) : function(object) { + * return match[2] == 'gt' ? object[match[1]] > match[3] : object[match[1]] < match[3]; + * }; + * }); + * + * _.filter(characters, 'age__gt38'); + * // => [{ 'name': 'fred', 'age': 40 }] + */ + function createCallback(func, thisArg, argCount) { + var type = typeof func; + if (func == null || type == 'function') { + return baseCreateCallback(func, thisArg, argCount); + } + // handle "_.pluck" style callback shorthands + if (type != 'object') { + return property(func); + } + var props = keys(func); + return function(object) { + var length = props.length, + result = false; + + while (length--) { + if (!(result = object[props[length]] === func[props[length]])) { + break; + } + } + return result; + }; + } + + /** + * Converts the characters `&`, `<`, `>`, `"`, and `'` in `string` to their + * corresponding HTML entities. + * + * @static + * @memberOf _ + * @category Utilities + * @param {string} string The string to escape. + * @returns {string} Returns the escaped string. + * @example + * + * _.escape('Fred, Wilma, & Pebbles'); + * // => 'Fred, Wilma, & Pebbles' + */ + function escape(string) { + return string == null ? '' : String(string).replace(reUnescapedHtml, escapeHtmlChar); + } + + /** + * This method returns the first argument provided to it. + * + * @static + * @memberOf _ + * @category Utilities + * @param {*} value Any value. + * @returns {*} Returns `value`. + * @example + * + * var object = { 'name': 'fred' }; + * _.identity(object) === object; + * // => true + */ + function identity(value) { + return value; + } + + /** + * Adds function properties of a source object to the destination object. + * If `object` is a function methods will be added to its prototype as well. + * + * @static + * @memberOf _ + * @category Utilities + * @param {Function|Object} [object=lodash] object The destination object. + * @param {Object} source The object of functions to add. + * @param {Object} [options] The options object. + * @param {boolean} [options.chain=true] Specify whether the functions added are chainable. + * @example + * + * function capitalize(string) { + * return string.charAt(0).toUpperCase() + string.slice(1).toLowerCase(); + * } + * + * _.mixin({ 'capitalize': capitalize }); + * _.capitalize('fred'); + * // => 'Fred' + * + * _('fred').capitalize().value(); + * // => 'Fred' + * + * _.mixin({ 'capitalize': capitalize }, { 'chain': false }); + * _('fred').capitalize(); + * // => 'Fred' + */ + function mixin(object) { + forEach(functions(object), function(methodName) { + var func = lodash[methodName] = object[methodName]; + + lodash.prototype[methodName] = function() { + var args = [this.__wrapped__]; + push.apply(args, arguments); + + var result = func.apply(lodash, args); + return this.__chain__ + ? new lodashWrapper(result, true) + : result; + }; + }); + } + + /** + * Reverts the '_' variable to its previous value and returns a reference to + * the `lodash` function. + * + * @static + * @memberOf _ + * @category Utilities + * @returns {Function} Returns the `lodash` function. + * @example + * + * var lodash = _.noConflict(); + */ + function noConflict() { + root._ = oldDash; + return this; + } + + /** + * A no-operation function. + * + * @static + * @memberOf _ + * @category Utilities + * @example + * + * var object = { 'name': 'fred' }; + * _.noop(object) === undefined; + * // => true + */ + function noop() { + // no operation performed + } + + /** + * Gets the number of milliseconds that have elapsed since the Unix epoch + * (1 January 1970 00:00:00 UTC). + * + * @static + * @memberOf _ + * @category Utilities + * @example + * + * var stamp = _.now(); + * _.defer(function() { console.log(_.now() - stamp); }); + * // => logs the number of milliseconds it took for the deferred function to be called + */ + var now = isNative(now = Date.now) && now || function() { + return new Date().getTime(); + }; + + /** + * Creates a "_.pluck" style function, which returns the `key` value of a + * given object. + * + * @static + * @memberOf _ + * @category Utilities + * @param {string} key The name of the property to retrieve. + * @returns {Function} Returns the new function. + * @example + * + * var characters = [ + * { 'name': 'fred', 'age': 40 }, + * { 'name': 'barney', 'age': 36 } + * ]; + * + * var getName = _.property('name'); + * + * _.map(characters, getName); + * // => ['barney', 'fred'] + * + * _.sortBy(characters, getName); + * // => [{ 'name': 'barney', 'age': 36 }, { 'name': 'fred', 'age': 40 }] + */ + function property(key) { + return function(object) { + return object[key]; + }; + } + + /** + * Produces a random number between `min` and `max` (inclusive). If only one + * argument is provided a number between `0` and the given number will be + * returned. If `floating` is truey or either `min` or `max` are floats a + * floating-point number will be returned instead of an integer. + * + * @static + * @memberOf _ + * @category Utilities + * @param {number} [min=0] The minimum possible value. + * @param {number} [max=1] The maximum possible value. + * @param {boolean} [floating=false] Specify returning a floating-point number. + * @returns {number} Returns a random number. + * @example + * + * _.random(0, 5); + * // => an integer between 0 and 5 + * + * _.random(5); + * // => also an integer between 0 and 5 + * + * _.random(5, true); + * // => a floating-point number between 0 and 5 + * + * _.random(1.2, 5.2); + * // => a floating-point number between 1.2 and 5.2 + */ + function random(min, max) { + if (min == null && max == null) { + max = 1; + } + min = +min || 0; + if (max == null) { + max = min; + min = 0; + } else { + max = +max || 0; + } + return min + floor(nativeRandom() * (max - min + 1)); + } + + /** + * Resolves the value of property `key` on `object`. If `key` is a function + * it will be invoked with the `this` binding of `object` and its result returned, + * else the property value is returned. If `object` is falsey then `undefined` + * is returned. + * + * @static + * @memberOf _ + * @category Utilities + * @param {Object} object The object to inspect. + * @param {string} key The name of the property to resolve. + * @returns {*} Returns the resolved value. + * @example + * + * var object = { + * 'cheese': 'crumpets', + * 'stuff': function() { + * return 'nonsense'; + * } + * }; + * + * _.result(object, 'cheese'); + * // => 'crumpets' + * + * _.result(object, 'stuff'); + * // => 'nonsense' + */ + function result(object, key) { + if (object) { + var value = object[key]; + return isFunction(value) ? object[key]() : value; + } + } + + /** + * A micro-templating method that handles arbitrary delimiters, preserves + * whitespace, and correctly escapes quotes within interpolated code. + * + * Note: In the development build, `_.template` utilizes sourceURLs for easier + * debugging. See http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl + * + * For more information on precompiling templates see: + * http://lodash.com/custom-builds + * + * For more information on Chrome extension sandboxes see: + * http://developer.chrome.com/stable/extensions/sandboxingEval.html + * + * @static + * @memberOf _ + * @category Utilities + * @param {string} text The template text. + * @param {Object} data The data object used to populate the text. + * @param {Object} [options] The options object. + * @param {RegExp} [options.escape] The "escape" delimiter. + * @param {RegExp} [options.evaluate] The "evaluate" delimiter. + * @param {Object} [options.imports] An object to import into the template as local variables. + * @param {RegExp} [options.interpolate] The "interpolate" delimiter. + * @param {string} [sourceURL] The sourceURL of the template's compiled source. + * @param {string} [variable] The data object variable name. + * @returns {Function|string} Returns a compiled function when no `data` object + * is given, else it returns the interpolated text. + * @example + * + * // using the "interpolate" delimiter to create a compiled template + * var compiled = _.template('hello <%= name %>'); + * compiled({ 'name': 'fred' }); + * // => 'hello fred' + * + * // using the "escape" delimiter to escape HTML in data property values + * _.template('<%- value %>', { 'value': '