libBLOC

/*
 * Copyright (C) 2023 Barry
 *
 * This file is part of Barry's Little Objects in C Library (libBLOC).
 *
 * libBLOC is free software: you can redistribute it and/or modify it under the
 * terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later
 * version.
 *
 * libBLOC is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTIBILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * libBLOC.  If not, see <https://www.gnu.org/licenses/>.
 */

#include <stddef.h>
#include <BLOC/iterator.h>
#include "iterator.h"

/* Get the next iterable element */
void *
iterator_next(Iterator *iter)
{
	iter->entry = iter->next;
	if (!iter->entry)
		return NULL;
	iter->prev = iter->entry->prev;
	iter->next = iter->entry->next;
	iter->pos++;
	return iter->entry->obj;
}

/* Get the previous iterable element */
void *
iterator_prev(Iterator *iter)
{
	iter->entry = iter->prev;
	if (!iter->entry)
		return NULL;
	iter->prev = iter->entry->prev;
	iter->next = iter->entry->next;
	iter->pos--;
	return iter->entry->obj;
}