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/**
* 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;