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: /**
17: * @template TKey
18: * @template T
19: */
20: interface Reduce
21: {
22: /**
23: * Reduce a collection using a `$predicate`.
24: *
25: * The reduction function is passed an accumulator value and the current
26: * iterator value and returns a new accumulator. The accumulator is
27: * initialised to `$initial`.
28: *
29: * @template TAcc
30: *
31: * @param (\Closure(TAcc, T, TKey): TAcc) $predicate
32: * @param TAcc $initial
33: *
34: * @return TAcc
35: */
36: public function reduce(\Closure $predicate, mixed $initial = null): mixed;
37: }
38: