/*
    Copyright (C) 2012, Aaron Lindsay <aaron@aclindsay.com>

    This file is part of Aedrix.

    This program 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 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY 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 this program; if not, write to the Free Software Foundation, Inc.,
    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#ifndef LIST_H
#define LIST_H

/*
 * Assuming ptr is a pointer to a member variable of type parent_type, and ptr
 * is named member in parent_type, find the address of the struct which owns
 * ptr.
 */
#define container(ptr, parent_type, member) \
	((parent_type *) ((char *)ptr - (char *)&((parent_type *)0)->member))

/*
 * Given a pointer to a struct (head) of type dlist_node, which points to a
 * list of type parent_type, and a pointer of that type (it), this macro will
 * execute the contained instructions once for each list element, with 'it' set
 * to each element in the list, in turn.
 */
#define for_each_list(it, head, parent_type, member) \
	for (it = container((head)->next, parent_type, member); it->member.next != (head); it = container(it->member.next, parent_type, member))

#define for_each_list_noinit(it, head, parent_type, member) \
	for (; it->member.next != (head); it = container(it->member.next, parent_type, member))

struct dlist_node {
	struct dlist_node *next, *prev;
};

void init_list(struct dlist_node *n);
int list_empty(struct dlist_node *n);

//functions for dealing with single list elements
void insert_after(struct dlist_node *n, struct dlist_node *to_add);
void insert_before(struct dlist_node *n, struct dlist_node *to_add);
void remove(struct dlist_node *to_remove);

//functions for dealing with one or more elements
void remove_splice(struct dlist_node *from, struct dlist_node *to);
void insert_splice_before(struct dlist_node *n, struct dlist_node *first, struct dlist_node *last);

#endif /* LIST_H */