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/>.
 */

#ifndef _BLOC_ITERATOR_H
#define _BLOC_ITERATOR_H

typedef struct Iterator Iterator;

/* Structure for an Iterable object header */
struct Iterable {
	unsigned int magic;
	struct IterableEntry *start, *end;
	unsigned int entries;
};

/* Structure for an Iterable object entry header */
struct IterableEntry {
	struct IterableEntry *prev, *next;
	void *obj;
};

void iterable_init(struct Iterable *header);

Iterator *iterator_create(void *iterable);
void *iterator_first(Iterator *iter);
void *iterator_last(Iterator *iter);
void *iterator_next(Iterator *iter);
void *iterator_prev(Iterator *iter);

#define foreach(l,i) for (Iterator *(__l_##i) = iterator_create((void *) (l)); \
                          (__l_##i); obj_put(__l_##i), (__l_##i) = NULL) \
                     for ((i) = iterator_first(__l_##i); (i); \
                          (i) = iterator_next(__l_##i))

#endif