YamlDirectoryIterator.php

<?php

/**
 * @file
 * Contains \Drupal\Component\Discovery\YamlDirectoryIterator.
 */

namespace Drupal\Component\Discovery;

class YamlDirectoryIterator extends \FilterIterator {

  /**
   * YamlDirectoryIterator constructor.
   *
   * @param string $path
   */
  public function __construct($path) {
    $iterator = new \FileSystemIterator($path);
    parent::__construct($iterator);
  }

  /**
   * Implements \FilterIterator::accept().
   */
  public function accept() {
    /** @var \SplFileInfo $file_info */
    $file_info = $this->getInnerIterator()->current();
    return $file_info->isFile() && ($file_info->getExtension() === 'yml');
  }

}