drupol\phpermutations\Generators\Permutations

Complexity

Total Complexity

12

Size/Duplication

Total Lines	101
Duplicated Lines	0 %

Coupling/Cohesion

Dependencies

2

Test Coverage

Coverage

100%

Importance

Changes

0

6 Methods

Rating	Name	Duplication	Size	Complexity
A	__construct()	0	4	1
A	generator()	0	3	1
A	get()	0	7	3
A	getPermutations()	0	14	4
A	toArray()	0	9	2
A	count()	0	3	1

<?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
   */
  public $combinations;

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

  /**
   * Alias of the get() method.
   *
   * @return \Generator
   *   The prime generator.
   */
  public function generator() {
    return $this->get($this->getDataset(), $this->getLength());
  }

  /**
   * The combination generator.
   *
   * @param array $dataset
   *   The dataset.
   * @param int $length
   *   The length.
   *
   * @codingStandardsIgnoreStart
   * @return \Generator
   * @codingStandardsIgnoreEnd
   */
  protected function get(array $dataset, $length) {
    foreach ($this->combinations->generator() as $combination) {
      foreach ($this->getPermutations($combination) as $current) {
        yield $current;
      }
    }
  }

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

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

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

    return $data;
  }

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

}