/*
* Doubly linked list primitives
* Copyright
* (C) 1992 Joseph H. Allen
*
* This file is part of JOE (Joe's Own Editor)
*/
extern void *ITEM;
extern void *QUEUE;
extern void *LAST;
struct stditem {
LINK(STDITEM) link;
};
/* Initialize a doubly-linked list */
#define izque(type,member,item) do { \
QUEUE = (void *)(item); \
((type *)QUEUE)->member.prev = (type *)QUEUE; \
((type *)QUEUE)->member.next = (type *)QUEUE; \
} while(0)
/* Remove an item from a list */
#define deque(type,member,item) do { \
ITEM = (void *)(item); \
((type *)ITEM)->member.prev->member.next = ((type *)ITEM)->member.next; \
((type *)ITEM)->member.next->member.prev = ((type *)ITEM)->member.prev; \
} while(0)
/* Remove an item from a list and return it */
#define deque_f(type,member,item) \
( \
ITEM=(void *)(item), \
((type *)ITEM)->member.prev->member.next=((type *)ITEM)->member.next, \
((type *)ITEM)->member.next->member.prev=((type *)ITEM)->member.prev, \
(type *)ITEM \
)
/* Return true if doubly-linked list is empty */
#define qempty(type,member,item) \
( \
QUEUE=(void *)(item), \
(type *)QUEUE==((type *)QUEUE)->member.next \
)
/* Insert an item at front of list */
#define enquef(type,member,queue,item) do { \
ITEM = (void *)(item); \
QUEUE = (void *)(queue); \
((type *)ITEM)->member.next = ((type *)QUEUE)->member.next; \
((type *)ITEM)->member.prev = (type *)QUEUE; \
((type *)QUEUE)->member.next->member.prev = (type *)ITEM; \
((type *)QUEUE)->member.next = (type *)ITEM; \
} while(0)
/* Insert an item at back of list */
#define enqueb(type,member,queue,item) do { \
ITEM = (void *)(item); \
QUEUE = (void *)(queue); \
((type *)ITEM)->member.next = (type *)QUEUE; \
((type *)ITEM)->member.prev = ((type *)QUEUE)->member.prev; \
((type *)QUEUE)->member.prev->member.next = (type *)ITEM; \
((type *)QUEUE)->member.prev = (type *)ITEM; \
} while(0)
/* Insert an item at front of list and return it */
#define enqueb_f(type,member,queue,item) \
( \
ITEM=(void *)(item), \
QUEUE=(void *)(queue), \
((type *)ITEM)->member.next=(type *)QUEUE, \
((type *)ITEM)->member.prev=((type *)QUEUE)->member.prev, \
((type *)QUEUE)->member.prev->member.next=(type *)ITEM, \
((type *)QUEUE)->member.prev=(type *)ITEM, \
(type *)ITEM \
)
/* Promote an item to front of list */
#define promote(type,member,queue,item) \
enquef(type,member,(queue),deque_f(type,member,(item)))
/* Demote an item to back of list */
#define demote(type,member,queue,item) \
enqueb(type,member,(queue),deque_f(type,member,(item)))
/* Splice a chain into from of a list */
#define splicef(type,member,queue,chain) do { \
ITEM = (void *)(chain); \
LAST = (void *)((type *)ITEM)->member.prev; \
QUEUE = (void *)(queue); \
((type *)LAST)->member.next = ((type *)QUEUE)->member.next; \
((type *)ITEM)->member.prev = (type *)QUEUE; \
((type *)QUEUE)->member.next->member.prev = (type *)LAST; \
((type *)QUEUE)->member.next = (type *)ITEM; \
} while(0)
/* Splice a chain into back of a list */
#define spliceb(type,member,queue,chain) do { \
ITEM = (void *)(chain); \
LAST = (void *)((type *)ITEM)->member.prev; \
QUEUE = (void *)(queue); \
((type *)LAST)->member.next = (type *)QUEUE; \
((type *)ITEM)->member.prev = ((type *)QUEUE)->member.prev; \
((type *)QUEUE)->member.prev->member.next = (type *)ITEM; \
((type *)QUEUE)->member.prev = (type *)LAST; \
} while(0)
#define spliceb_f(type,member,queue,chain) \
( \
ITEM=(void *)(chain), \
LAST=(void *)((type *)ITEM)->member.prev, \
QUEUE=(void *)(queue), \
((type *)LAST)->member.next=(type *)QUEUE, \
((type *)ITEM)->member.prev=((type *)QUEUE)->member.prev, \
((type *)QUEUE)->member.prev->member.next=(type *)ITEM, \
((type *)QUEUE)->member.prev=(type *)LAST, \
(type *)ITEM \
)
/* Remove a range of items from a list and return it as a chain for later splicing */
#define snip(type,member,first,last) \
( \
ITEM=(void *)(first), \
LAST=(void *)(last), \
((type *)LAST)->member.next->member.prev=((type *)ITEM)->member.prev, \
((type *)ITEM)->member.prev->member.next=((type *)LAST)->member.next, \
((type *)ITEM)->member.prev=(type *)LAST, \
((type *)LAST)->member.next=(type *)ITEM, \
(type *)ITEM \
)
/* Allocate an item */
void *alitem(void *list, ptrdiff_t itemsize);
/* Free an item */
void frchn(void *list, void *ch);
