1*40412Sbostic /*
2*40412Sbostic * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
3*40412Sbostic * All rights reserved.
440411Sbostic *
5*40412Sbostic * This code is derived from software contributed to Berkeley by
6*40412Sbostic * Adam de Boor.
740411Sbostic *
8*40412Sbostic * Redistribution and use in source and binary forms are permitted
9*40412Sbostic * provided that the above copyright notice and this paragraph are
10*40412Sbostic * duplicated in all such forms and that any documentation,
11*40412Sbostic * advertising materials, and other materials related to such
12*40412Sbostic * distribution and use acknowledge that the software was developed
13*40412Sbostic * by the University of California, Berkeley. The name of the
14*40412Sbostic * University may not be used to endorse or promote products derived
15*40412Sbostic * from this software without specific prior written permission.
16*40412Sbostic * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
17*40412Sbostic * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
18*40412Sbostic * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
1940411Sbostic */
20*40412Sbostic
2140411Sbostic #ifndef lint
22*40412Sbostic static char sccsid[] = "@(#)lstPred.c 5.2 (Berkeley) 03/11/90";
23*40412Sbostic #endif /* not lint */
2440411Sbostic
25*40412Sbostic /*-
26*40412Sbostic * LstPred.c --
27*40412Sbostic * Return the predecessor of a given list node
28*40412Sbostic */
29*40412Sbostic
3040411Sbostic #include "lstInt.h"
3140411Sbostic
3240411Sbostic /*-
3340411Sbostic *-----------------------------------------------------------------------
3440411Sbostic * Lst_Pred --
3540411Sbostic * Return the predecessor of the given node.
3640411Sbostic *
3740411Sbostic * Results:
3840411Sbostic * The node's predecessor, if any, or NILLNODE if it has none.
3940411Sbostic *
4040411Sbostic * Side Effects:
4140411Sbostic * None.
4240411Sbostic *
4340411Sbostic *-----------------------------------------------------------------------
4440411Sbostic */
4540411Sbostic LstNode
Lst_Pred(ln)4640411Sbostic Lst_Pred (ln)
4740411Sbostic LstNode ln;
4840411Sbostic {
4940411Sbostic if (ln == NILLNODE) {
5040411Sbostic return (NILLNODE);
5140411Sbostic } else {
5240411Sbostic return ((LstNode)((ListNode) ln)->prevPtr);
5340411Sbostic }
5440411Sbostic }
5540411Sbostic
56