php-src/ext/spl/internal/splstack.inc
2009-05-02 01:52:54 +00:00

49 lines
1.5 KiB
PHP

<?php
/** @file splstack.inc
* @ingroup SPL
* @brief class SplStack
* @author Etienne Kneuss
* @date 2008 - 2009
*
* SPL - Standard PHP Library
*/
/** @ingroup SPL
* @brief Implementation of a stack through a DoublyLinkedList. As SplStack
* extends SplDoublyLinkedList, shift() and unshift() are still available even
* though they don't make much sense for a stack.
* @since PHP 5.3
*
* The SplStack class provides the main functionalities of a
* stack implemented using a doubly linked list (DLL).
*/
class SplStack extends SplDoublyLinkedList
{
protected $_it_mode = parent::IT_MODE_LIFO;
/** Changes the iteration mode. There are two orthogonal sets of modes that
* can be set:
*
* - The behavior of the iterator (either one or the other)
* - SplDoublyLnkedList::IT_MODE_DELETE (Elements are deleted by the iterator)
* - SplDoublyLnkedList::IT_MODE_KEEP (Elements are traversed by the iterator)
*
* The default mode is 0 : SplDoublyLnkedList::IT_MODE_LIFO | SplDoublyLnkedList::IT_MODE_KEEP
*
* @note The iteration's direction is not modifiable for stack instances
* @param $mode New mode of iteration
* @throw RuntimeException If the new mode affects the iteration's direction.
*/
public function setIteratorMode($mode)
{
if ($mode & parent::IT_MODE_LIFO !== parent::IT_MODE_LIFO) {
throw new RuntimeException("Iterators' LIFO/FIFO modes for SplStack/SplQueue objects are frozen");
}
$this->_it_mode = $mode;
}
}
?>