| /** |
| * Lo-Dash 2.4.1 (Custom Build) <http://lodash.com/> |
| * Build: `lodash modularize exports="node" -o ./compat/` |
| * Copyright 2012-2013 The Dojo Foundation <http://dojofoundation.org/> |
| * Based on Underscore.js 1.5.2 <http://underscorejs.org/LICENSE> |
| * Copyright 2009-2013 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors |
| * Available under MIT license <http://lodash.com/license> |
| */ |
| var createAggregator = require('../internals/createAggregator'); |
| |
| /** |
| * 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; |
| }); |
| |
| module.exports = indexBy; |