1: <?php
2:
3: declare(strict_types=1);
4:
5: /**
6: * This file is part of the Nexus framework.
7: *
8: * (c) John Paul E. Balandan, CPA <paulbalandan@gmail.com>
9: *
10: * For the full copyright and license information, please view
11: * the LICENSE file that was distributed with this source code.
12: */
13:
14: namespace Nexus\Collection\Operation;
15:
16: use Nexus\Collection\CollectionInterface;
17:
18: /**
19: * @template TKey
20: * @template T
21: */
22: interface Reductions
23: {
24: /**
25: * Returns a new collection consisting of the intermediate values
26: * of reducing the collection using a `$predicate`.
27: *
28: * The reduction `$predicate` is passed an `$initial` accumulator
29: * and the current collection value and returns a new accumulator.
30: *
31: * Reductions returns a list of every accumulator along the way.
32: *
33: * @template TAcc
34: *
35: * @param (\Closure(TAcc, T, TKey): TAcc) $predicate
36: * @param TAcc $initial
37: *
38: * @return CollectionInterface<int, TAcc>
39: */
40: public function reductions(\Closure $predicate, mixed $initial = null): CollectionInterface;
41: }
42: