/*
* Functions for dealing with linked lists of goodies
*
* @(#)list.c 4.7 (Berkeley) 12/19/81
*
* Rogue: Exploring the Dungeons of Doom
* Copyright (C) 1980, 1981, 1982 Michael Toy, Ken Arnold and Glenn Wichman
* All rights reserved.
*
* See the file LICENSE.TXT for full copyright and licensing information.
*/
#include <stdlib.h>
#include <curses.h>
#include "rogue.h"
/*
* detach:
* Takes an item out of whatever linked list it might be in
*/
void
_detach(THING **list, THING *item)
{
if (*list == item)
*list = next(item);
if (prev(item) != NULL) item->l_prev->l_next = next(item);
if (next(item) != NULL) item->l_next->l_prev = prev(item);
item->l_next = NULL;
item->l_prev = NULL;
}
/*
* _attach:
* add an item to the head of a list
*/
void
_attach(THING **list, THING *item)
{
if (*list != NULL)
{
item->l_next = *list;
(*list)->l_prev = item;
item->l_prev = NULL;
}
else
{
item->l_next = NULL;
item->l_prev = NULL;
}
*list = item;
}
/*
* _free_list:
* Throw the whole blamed thing away
*/
void
_free_list(THING **ptr)
{
register THING *item;
while (*ptr != NULL)
{
item = *ptr;
*ptr = next(item);
discard(item);
}
}
/*
* discard:
* Free up an item
*/
void
discard(THING *item)
{
total--;
free((char *) item);
}
/*
* new_item
* Get a new item with a specified size
*/
THING *
new_item(void)
{
register THING *item;
if ((item = calloc(1, sizeof *item)) == NULL)
msg("ran out of memory after %d items", total);
else
total++;
item->l_next = item->l_prev = NULL;
return item;
}