[bpt/emacs.git] / oldXMenu / insque.c

/* This file implements the emacs_insque and emacs_remque functions,
   copies of the insque and remque functions of BSD.  They and all
   their callers have been renamed to emacs_mumble to allow us to
   include this file in the menu library on all systems.  */


struct qelem {
  struct    qelem *q_forw;
  struct    qelem *q_back;
  char q_data[1];
};

/* Insert ELEM into a doubly-linked list, after PREV.  */

void
emacs_insque (elem, prev) 
     struct qelem *elem, *prev;
{
  struct qelem *next = prev->q_forw;
  prev->q_forw = elem;
  if (next)
    next->q_back = elem;
  elem->q_forw = next;
  elem->q_back = prev;
}

/* Unlink ELEM from the doubly-linked list that it is in.  */

emacs_remque (elem)
     struct qelem *elem;
{
  struct qelem *next = elem->q_forw;
  struct qelem *prev = elem->q_back;
  if (next)
    next->q_back = prev;
  if (prev)
    prev->q_forw = next;
}
Commit	Line	Data
e745ede7 DL	1	/* This file implements the emacs_insque and emacs_remque functions,
	2	copies of the insque and remque functions of BSD. They and all
	3	their callers have been renamed to emacs_mumble to allow us to
	4	include this file in the menu library on all systems. */
	5
	6
	7	struct qelem {
	8	struct qelem *q_forw;
	9	struct qelem *q_back;
	10	char q_data[1];
	11	};
	12
	13	/* Insert ELEM into a doubly-linked list, after PREV. */
	14
	15	void
	16	emacs_insque (elem, prev)
	17	struct qelem elem, prev;
	18	{
	19	struct qelem *next = prev->q_forw;
	20	prev->q_forw = elem;
	21	if (next)
	22	next->q_back = elem;
	23	elem->q_forw = next;
	24	elem->q_back = prev;
	25	}
	26
	27	/* Unlink ELEM from the doubly-linked list that it is in. */
	28
	29	emacs_remque (elem)
	30	struct qelem *elem;
	31	{
	32	struct qelem *next = elem->q_forw;
	33	struct qelem *prev = elem->q_back;
	34	if (next)
	35	next->q_back = prev;
	36	if (prev)
	37	prev->q_forw = next;
	38	}