source: trip-planner-front/node_modules/lodash/transform.js@ 8d391a1

Last change on this file since 8d391a1 was 6a3a178, checked in by Ema <ema_spirova@…>, 3 years ago

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1var arrayEach = require('./_arrayEach'),
2 baseCreate = require('./_baseCreate'),
3 baseForOwn = require('./_baseForOwn'),
4 baseIteratee = require('./_baseIteratee'),
5 getPrototype = require('./_getPrototype'),
6 isArray = require('./isArray'),
7 isBuffer = require('./isBuffer'),
8 isFunction = require('./isFunction'),
9 isObject = require('./isObject'),
10 isTypedArray = require('./isTypedArray');
11
12/**
13 * An alternative to `_.reduce`; this method transforms `object` to a new
14 * `accumulator` object which is the result of running each of its own
15 * enumerable string keyed properties thru `iteratee`, with each invocation
16 * potentially mutating the `accumulator` object. If `accumulator` is not
17 * provided, a new object with the same `[[Prototype]]` will be used. The
18 * iteratee is invoked with four arguments: (accumulator, value, key, object).
19 * Iteratee functions may exit iteration early by explicitly returning `false`.
20 *
21 * @static
22 * @memberOf _
23 * @since 1.3.0
24 * @category Object
25 * @param {Object} object The object to iterate over.
26 * @param {Function} [iteratee=_.identity] The function invoked per iteration.
27 * @param {*} [accumulator] The custom accumulator value.
28 * @returns {*} Returns the accumulated value.
29 * @example
30 *
31 * _.transform([2, 3, 4], function(result, n) {
32 * result.push(n *= n);
33 * return n % 2 == 0;
34 * }, []);
35 * // => [4, 9]
36 *
37 * _.transform({ 'a': 1, 'b': 2, 'c': 1 }, function(result, value, key) {
38 * (result[value] || (result[value] = [])).push(key);
39 * }, {});
40 * // => { '1': ['a', 'c'], '2': ['b'] }
41 */
42function transform(object, iteratee, accumulator) {
43 var isArr = isArray(object),
44 isArrLike = isArr || isBuffer(object) || isTypedArray(object);
45
46 iteratee = baseIteratee(iteratee, 4);
47 if (accumulator == null) {
48 var Ctor = object && object.constructor;
49 if (isArrLike) {
50 accumulator = isArr ? new Ctor : [];
51 }
52 else if (isObject(object)) {
53 accumulator = isFunction(Ctor) ? baseCreate(getPrototype(object)) : {};
54 }
55 else {
56 accumulator = {};
57 }
58 }
59 (isArrLike ? arrayEach : baseForOwn)(object, function(value, index, object) {
60 return iteratee(accumulator, value, index, object);
61 });
62 return accumulator;
63}
64
65module.exports = transform;
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