* @license http://opensource.org/licenses/MIT MIT */ declare(strict_types=1); namespace Ramsey\Collection; use Ramsey\Collection\Exception\InvalidArgumentException; use Ramsey\Collection\Exception\NoSuchElementException; use Ramsey\Collection\Tool\TypeTrait; use Ramsey\Collection\Tool\ValueToStringTrait; use function array_key_first; /** * This class provides a basic implementation of `QueueInterface`, to minimize * the effort required to implement this interface. * * @template T * @extends AbstractArray * @implements QueueInterface */ class Queue extends AbstractArray implements QueueInterface { use TypeTrait; use ValueToStringTrait; /** * Constructs a queue object of the specified type, optionally with the * specified data. * * @param string $queueType The type or class name associated with this queue. * @param array $data The initial items to store in the queue. */ public function __construct(private readonly string $queueType, array $data = []) { parent::__construct($data); } /** * {@inheritDoc} * * Since arbitrary offsets may not be manipulated in a queue, this method * serves only to fulfill the `ArrayAccess` interface requirements. It is * invoked by other operations when adding values to the queue. * * @throws InvalidArgumentException if $value is of the wrong type. */ public function offsetSet(mixed $offset, mixed $value): void { if ($this->checkType($this->getType(), $value) === false) { throw new InvalidArgumentException( 'Value must be of type ' . $this->getType() . '; value is ' . $this->toolValueToString($value), ); } $this->data[] = $value; } /** * @throws InvalidArgumentException if $value is of the wrong type. */ public function add(mixed $element): bool { $this[] = $element; return true; } /** * @return T * * @throws NoSuchElementException if this queue is empty. */ public function element(): mixed { return $this->peek() ?? throw new NoSuchElementException( 'Can\'t return element from Queue. Queue is empty.', ); } public function offer(mixed $element): bool { try { return $this->add($element); } catch (InvalidArgumentException) { return false; } } /** * @return T | null */ public function peek(): mixed { $index = array_key_first($this->data); if ($index === null) { return null; } return $this[$index]; } /** * @return T | null */ public function poll(): mixed { $index = array_key_first($this->data); if ($index === null) { return null; } $head = $this[$index]; unset($this[$index]); return $head; } /** * @return T * * @throws NoSuchElementException if this queue is empty. */ public function remove(): mixed { return $this->poll() ?? throw new NoSuchElementException( 'Can\'t return element from Queue. Queue is empty.', ); } public function getType(): string { return $this->queueType; } }