Files
lodash/lodash.transform/index.js
2016-08-12 13:45:38 -07:00

110 lines
3.5 KiB
JavaScript

/**
* lodash 3.0.2 (Custom Build) <https://lodash.com/>
* Build: `lodash modern modularize exports="npm" -o ./`
* Copyright 2012-2015 The Dojo Foundation <http://dojofoundation.org/>
* Based on Underscore.js 1.8.2 <http://underscorejs.org/LICENSE>
* Copyright 2009-2015 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
* Available under MIT license <https://lodash.com/license>
*/
var arrayEach = require('lodash._arrayeach'),
baseCallback = require('lodash._basecallback'),
baseCreate = require('lodash._basecreate'),
baseFor = require('lodash._basefor'),
isArray = require('lodash.isarray'),
isFunction = require('lodash.isfunction'),
isTypedArray = require('lodash.istypedarray'),
keys = require('lodash.keys');
/**
* The base implementation of `_.forOwn` without support for callback
* shorthands and `this` binding.
*
* @private
* @param {Object} object The object to iterate over.
* @param {Function} iteratee The function invoked per iteration.
* @returns {Object} Returns `object`.
*/
function baseForOwn(object, iteratee) {
return baseFor(object, iteratee, keys);
}
/**
* Checks if `value` is the [language type](https://es5.github.io/#x8) of `Object`.
* (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
*
* @static
* @memberOf _
* @category Lang
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if `value` is an object, else `false`.
* @example
*
* _.isObject({});
* // => true
*
* _.isObject([1, 2, 3]);
* // => true
*
* _.isObject(1);
* // => false
*/
function isObject(value) {
// Avoid a V8 JIT bug in Chrome 19-20.
// See https://code.google.com/p/v8/issues/detail?id=2291 for more details.
var type = typeof value;
return type == 'function' || (!!value && type == 'object');
}
/**
* An alternative to `_.reduce`; this method transforms `object` to a new
* `accumulator` object which is the result of running each of its own enumerable
* properties through `iteratee`, with each invocation potentially mutating
* the `accumulator` object. The `iteratee` is bound to `thisArg` and invoked
* with four arguments: (accumulator, value, key, object). Iteratee functions
* may exit iteration early by explicitly returning `false`.
*
* @static
* @memberOf _
* @category Object
* @param {Array|Object} object The object to iterate over.
* @param {Function} [iteratee=_.identity] The function invoked per iteration.
* @param {*} [accumulator] The custom accumulator value.
* @param {*} [thisArg] The `this` binding of `iteratee`.
* @returns {*} Returns the accumulated value.
* @example
*
* _.transform([2, 3, 4], function(result, n) {
* result.push(n *= n);
* return n % 2 == 0;
* });
* // => [4, 9]
*
* _.transform({ 'a': 1, 'b': 2 }, function(result, n, key) {
* result[key] = n * 3;
* });
* // => { 'a': 3, 'b': 6 }
*/
function transform(object, iteratee, accumulator, thisArg) {
var isArr = isArray(object) || isTypedArray(object);
iteratee = baseCallback(iteratee, thisArg, 4);
if (accumulator == null) {
if (isArr || isObject(object)) {
var Ctor = object.constructor;
if (isArr) {
accumulator = isArray(object) ? new Ctor : [];
} else {
accumulator = baseCreate(isFunction(Ctor) && Ctor.prototype);
}
} else {
accumulator = {};
}
}
(isArr ? arrayEach : baseForOwn)(object, function(value, index, object) {
return iteratee(accumulator, value, index, object);
});
return accumulator;
}
module.exports = transform;