<?php

/** @file recursivecomparedualiterator.inc
 * @ingroup Examples
 * @brief class DualIterator
 * @author  Marcus Boerger
 * @date    2003 - 2006
 *
 * SPL - Standard PHP Library
 */

/** @ingroup Examples
 * @brief   Recursive comparison iterator for a RecursiveDualIterator
 * @author  Marcus Boerger
 * @version 1.0
 */
class RecursiveCompareDualIterator extends RecursiveIteratorIterator
{
	/** Used to keep end of recursion equality. That is en leaving a nesting
	 * level we need to check whether both child iterators are at their end.
	 */
	protected $equal = false;

	/** Construct from RecursiveDualIterator
	 *
	 * @param $it      RecursiveDualIterator
	 * @param $mode    should be LEAVES_ONLY
	 * @param $flags   should be 0
	 */
	function __construct(RecursiveDualIterator $it, $mode = self::LEAVES_ONLY, $flags = 0)
	{
		parent::__construct($it);
	}

	/** Rewind iteration andcomparison process. Starting with $equal = true.
	 */	
	function rewind()
	{
		$this->equal = true;
		parent::rewind();
	}

	/** Calculate $equal
	 * @see $equal
	 */
	function endChildren()
	{
		$this->equal &= !$this->getInnerIterator()->getLHS()->valid()
		             && !$this->getInnerIterator()->getRHS()->valid();
	}

	/** @return whether both inner iterators are valid and have identical 
	 * current and key values or both are non valid.
	 */
	function areIdentical()
	{
		return $this->equal && $this->getInnerIterator()->areIdentical();
	}

	/** @return whether both inner iterators are valid and have equal current 
	 * and key values or both are non valid.
	 */
	function areEqual()
	{
		return $this->equal && $this->getInnerIterator()->areEqual();
	}
}

?>
