1 /*
2  * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Adam de Boor.
7  *
8  * Redistribution and use in source and binary forms are permitted
9  * provided that the above copyright notice and this paragraph are
10  * duplicated in all such forms and that any documentation,
11  * advertising materials, and other materials related to such
12  * distribution and use acknowledge that the software was developed
13  * by the University of California, Berkeley.  The name of the
14  * University may not be used to endorse or promote products derived
15  * from this software without specific prior written permission.
16  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
19  */
20 
21 #ifndef lint
22 static char sccsid[] = "@(#)lstIsEmpty.c	5.2 (Berkeley) 03/11/90";
23 #endif /* not lint */
24 
25 /*-
26  * LstIsEmpty.c --
27  *	A single function to decide if a list is empty
28  */
29 
30 #include	"lstInt.h"
31 
32 /*-
33  *-----------------------------------------------------------------------
34  * Lst_IsEmpty --
35  *	Return TRUE if the given list is empty.
36  *
37  * Results:
38  *	TRUE if the list is empty, FALSE otherwise.
39  *
40  * Side Effects:
41  *	None.
42  *
43  *	A list is considered empty if its firstPtr == NilListNode (or if
44  *	the list itself is NILLIST).
45  *-----------------------------------------------------------------------
46  */
47 Boolean
48 Lst_IsEmpty (l)
49     Lst	l;
50 {
51     return ( ! LstValid (l) || LstIsEmpty(l));
52 }
53 
54