loophp\collection\Operation\Product

Complexity

Total Complexity

7

Size/Duplication

Total Lines	57
Duplicated Lines	0 %

Importance

Changes	1
Bugs	0	Features	0

3 Methods

Rating	Name	Duplication	Size	Complexity
A	on()	0	16	2
A	__construct()	0	3	1
A	cartesian()	0	13	4

<?php

declare(strict_types=1);

namespace loophp\collection\Operation;

use Closure;
use Generator;
use loophp\collection\Contract\Operation;
use loophp\collection\Iterator\IterableIterator;
use function count;

/**
 * Class Product.
 */
final class Product implements Operation
{
    /**
     * @var iterable[]
     */
    private $iterables;

    /**
     * Product constructor.
     *
     * @param iterable ...$iterables
     */
    public function __construct(iterable ...$iterables)
    {
        $this->iterables = $iterables;
    }

    /**
     * {@inheritdoc}
     */
    public function on(iterable $collection): Closure
    {
        $iterables = $this->iterables;

        $cartesian = function (iterable $input) {
            return $this->cartesian($input);
        };

        return static function () use ($iterables, $collection, $cartesian): Generator {
            $its = [$collection];

            foreach ($iterables as $iterable) {
                $its[] = new IterableIterator($iterable);
            }

            yield from $cartesian($its);
        };
    }

    /**
     * @param $iterable
     *
     * @return Generator|void
     */
    private function cartesian(iterable $iterable)
    {
        $u = array_pop($iterable);

$iterable of type iterable is incompatible with the type array expected by parameter $array of array_pop().

        if (null === $u) {
            yield [];

            return;
        }

        foreach ($this->cartesian($iterable) as $p) {
            foreach ($u as $v) {
                yield $p + [count($p) => $v];
            }
        }
    }
}