| var createAggregator = require('../internal/createAggregator'); |
| |
| /** |
| * Creates an object composed of keys generated from the results of running |
| * each element of `collection` through `iteratee`. The corresponding value |
| * of each key is the last element responsible for generating the key. The |
| * iteratee function is bound to `thisArg` and invoked with three arguments: |
| * (value, index|key, collection). |
| * |
| * If a property name is provided for `iteratee` the created `_.property` |
| * style callback returns the property value of the given element. |
| * |
| * If a value is also provided for `thisArg` the created `_.matchesProperty` |
| * style callback returns `true` for elements that have a matching property |
| * value, else `false`. |
| * |
| * If an object is provided for `iteratee` the created `_.matches` style |
| * callback returns `true` for elements that have the properties of the given |
| * object, else `false`. |
| * |
| * @static |
| * @memberOf _ |
| * @category Collection |
| * @param {Array|Object|string} collection The collection to iterate over. |
| * @param {Function|Object|string} [iteratee=_.identity] The function invoked |
| * per iteration. |
| * @param {*} [thisArg] The `this` binding of `iteratee`. |
| * @returns {Object} Returns the composed aggregate object. |
| * @example |
| * |
| * var keyData = [ |
| * { 'dir': 'left', 'code': 97 }, |
| * { 'dir': 'right', 'code': 100 } |
| * ]; |
| * |
| * _.indexBy(keyData, 'dir'); |
| * // => { 'left': { 'dir': 'left', 'code': 97 }, 'right': { 'dir': 'right', 'code': 100 } } |
| * |
| * _.indexBy(keyData, function(object) { |
| * return String.fromCharCode(object.code); |
| * }); |
| * // => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } } |
| * |
| * _.indexBy(keyData, function(object) { |
| * return this.fromCharCode(object.code); |
| * }, String); |
| * // => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } } |
| */ |
| var indexBy = createAggregator(function(result, value, key) { |
| result[key] = value; |
| }); |
| |
| module.exports = indexBy; |