oliverdavies.uk/src/Presentation/Collection/Collection.php

<?php

declare(strict_types=1);

namespace App\Presentation\Collection;

use ArrayIterator;
use Countable;
use Iterator;
use IteratorAggregate;

/**
 * @implements IteratorAggregate<TItem>
 * @template TItem
 */
class Collection implements Countable, IteratorAggregate
{
    /**
     * @param TItem[] $items
     */
    final public function __construct(protected array $items = [])
    {
    }

    public function count(): int
    {
        return count($this->items);
    }

    /**
     * @return self<TItem>
     */
    public function filter(callable $callback): self
    {
        return new static(
            array_filter(
                array: $this->items,
                callback: $callback,
            )
        );
    }

    public function getIterator(): Iterator
    {
        return new ArrayIterator($this->items);
    }

    /**
     * @return TItem[]
     */
    public function toArray(): array
    {
        return $this->items;
    }
}