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 Keys
23: {
24: /**
25: * Returns a new collection from keys of the original collection as
26: * the new values.
27: *
28: * @return CollectionInterface<int, TKey>
29: */
30: public function keys(): CollectionInterface;
31: }
32: