drupol\phpermutations\Generators\Permutations

Complexity

Total Complexity

11

Size/Duplication

Total Lines	91
Duplicated Lines	0 %

Coupling/Cohesion

Dependencies

2

Test Coverage

Coverage

100%

Importance

Changes

0

5 Methods

Rating	Name	Duplication	Size	Complexity
A	__construct()	0	5	1
A	generator()	0	8	3
A	toArray()	0	10	2
A	count()	0	4	1
A	get()	0	16	4

<?php

namespace drupol\phpermutations\Generators;

use drupol\phpermutations\Combinatorics;

/**
 * Class Permutations.
 *
 * @package drupol\phpermutations\Generators
 *
 * Inspired by the work of Mark Wilson <mark@89allport.co.uk>
 */
class Permutations extends Combinatorics
{
    /**
     * The combinations generator.
     *
     * @var \drupol\phpermutations\Generators\Combinations
     */
    protected $combinations;

    /**
     * Combinatorics constructor.
     *
     * @param array $dataset
     *   The dataset.
     * @param int|null $length
     *   The length.
     */
    public function __construct(array $dataset = [], $length = null)
    {
        parent::__construct($dataset, $length);
        $this->combinations = new Combinations($dataset, $this->getLength());
    }

    /**
     * Alias of the get() method.
     *
     * @codingStandardsIgnoreStart
     * @return \Generator
     * @codingStandardsIgnoreEnd
     */
    public function generator()
    {
        foreach ($this->combinations->generator() as $combination) {
            foreach ($this->get($combination) as $current) {
                yield $current;
            }
        }
    }

    /**
     * Convert the generator into an array.
     *
     * @return array
     *   The elements.
     */
    public function toArray()
    {
        $data = [];

        foreach ($this->generator() as $value) {
            $data[] = $value;
        }

        return $data;
    }

    /**
     * {@inheritdoc}
     */
    public function count()
    {
        return $this->combinations->count() * $this->fact($this->getLength());
    }

    /**
     * The permutations generator.
     *
     * @param array $dataset
     *   The dataset.
     *
     * @codingStandardsIgnoreStart
     * @return \Generator
     * @codingStandardsIgnoreEnd
     */
    protected function get(array $dataset)
    {
        foreach ($dataset as $key => $firstItem) {
            $remaining = $dataset;
            array_splice($remaining, $key, 1);
            if (count($remaining) === 0) {
                yield [$firstItem];

                continue;
            }
            foreach ($this->get($remaining) as $permutation) {
                array_unshift($permutation, $firstItem);
                yield $permutation;
            }
        }
    }
}