code.delx.au - gnu-emacs/blob - oldXMenu/insque.c

   1 /* Copyright (C) 2002, 2003, 2004, 2005,
   2                  2006 Free Software Foundation, Inc.  */
   3
   4 /* This file implements the emacs_insque and emacs_remque functions,
   5    copies of the insque and remque functions of BSD.  They and all
   6    their callers have been renamed to emacs_mumble to allow us to
   7    include this file in the menu library on all systems.  */
   8
   9
  10 struct qelem {
  11   struct    qelem *q_forw;
  12   struct    qelem *q_back;
  13   char q_data[1];
  14 };
  15
  16 /* Insert ELEM into a doubly-linked list, after PREV.  */
  17
  18 void
  19 emacs_insque (elem, prev)
  20      struct qelem *elem, *prev;
  21 {
  22   struct qelem *next = prev->q_forw;
  23   prev->q_forw = elem;
  24   if (next)
  25     next->q_back = elem;
  26   elem->q_forw = next;
  27   elem->q_back = prev;
  28 }
  29
  30 /* Unlink ELEM from the doubly-linked list that it is in.  */
  31
  32 emacs_remque (elem)
  33      struct qelem *elem;
  34 {
  35   struct qelem *next = elem->q_forw;
  36   struct qelem *prev = elem->q_back;
  37   if (next)
  38     next->q_back = prev;
  39   if (prev)
  40     prev->q_forw = next;
  41 }
  42
  43 /* arch-tag: a8719d1a-5c3f-4bce-b36b-173106d36165
  44    (do not change this comment) */