/**
* llist.h
* Copyright (c) 2022 Jon Santmyer <jon@jonsantmyer.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
*/
#ifndef LINKED_LIST_H
#define LINKED_LIST_H 1
#include <stddef.h>
/*List member structs must begin with this struct as the first member*/
struct llist_header
{
struct llist_header *prev, *next;
};
/*Marks an unknown-state llist header as a single member circular list*/
static inline void __llist_setup(struct llist_header *head)
{
head->prev = head->next = head;
}
#define llist_setup(head) __llist_setup((struct llist_header*)(head))
/*Fits a new node between prev and next*/
static inline void __llist_add(struct llist_header *new, struct llist_header *prev, struct llist_header *next)
{
new->prev = prev;
new->next = next;
prev->next = new;
next->prev = new;
}
#define llist_append(head, new) __llist_add(\
(struct llist_header*)(new), \
(struct llist_header*)(head), \
(struct llist_header*)(head->next))
#define llist_prepend(head, new) __llist_add(\
(struct llist_header*)(new), \
(struct llist_header*)(head->prev), \
(struct llist_header*)(head))
/*Seperates a node from prev and next, marking the removed as memberless*/
static inline void __llist_del(struct llist_header *node, struct llist_header *prev, struct llist_header *next)
{
prev->next = node->next;
next->prev = node->prev;
node->prev = node->next = NULL;
}
#define llist_del(node) __llist_del(\
(struct llist_header*)(node), \
(struct llist_header*)(node->prev), \
(struct llist_header*)(node->next))
/*Returns the list header i elements ahead of head*/
static inline struct llist_header *__llist_traverse(struct llist_header *head, size_t i)
{
if(head == NULL) return NULL;
for(; i != 0 && head != NULL; head = head->next, i--);
return head;
}
#define llist_traverse(head, i) __list_traverse((struct llist_header*)(head), i)
/*Returns how many jumps forwards it takes to reach find*/
static inline int __llist_at(struct llist_header *head, struct llist_header *find)
{
if(head == NULL) return -1;
int r = 1;
for(
struct llist_header *node = head->next;
node != head;
node = node->next, r++) {
if(node == find) return ++r;
}
return -1;
}
#define llist_at(head, find) __llist_at(\
(struct llist_header*)(head), \
(struct llist_header*)(find))
/*Define for easily looping through a llist*/
#define llist_foreach(node, head) \
for(struct llist_header *node = head->next; node != head; node = node->next)
#endif
