xref: /csrg-svn/usr.bin/make/lst.lib/lstCur.c (revision 40411)
1 /*-
2  * LstCur.c --
3  *	Return the current node in the list.
4  *	The sequential functions access the list in a slightly different way.
5  *	CurPtr points to their idea of the current node in the list and they
6  *	access the list based on it. Because the list is circular, Lst_Next
7  *	and Lst_Prev will go around the list forever. Lst_IsAtEnd must be
8  *	used to determine when to stop.
9  *
10  * Copyright (c) 1988 by University of California Regents
11  *
12  * Permission to use, copy, modify, and distribute this
13  * software and its documentation for any purpose and without
14  * fee is hereby granted, provided that the above copyright
15  * notice appears in all copies.  Neither the University of California nor
16  * Adam de Boor makes any representations about the suitability of this
17  * software for any purpose.  It is provided "as is" without
18  * express or implied warranty.
19  */
20 #ifndef lint
21 static char *rcsid =
22 "$Id: lstCur.c,v 1.4 88/11/17 20:52:03 adam Exp $ SPRITE (Berkeley)";
23 #endif lint
24 
25 #include	"lstInt.h"
26 
27 /*-
28  *-----------------------------------------------------------------------
29  * Lst_Cur --
30  *	Return the current node if the list is open for sequential
31  *	access.
32  *
33  * Results:
34  *	The current node or NILLNODE if the list isn't open..
35  *
36  * Side Effects:
37  *	None.
38  *
39  *-----------------------------------------------------------------------
40  */
41 LstNode
42 Lst_Cur (l)
43     Lst	    l;
44 {
45     register List list = (List)l;
46 
47     if ((LstValid(l) == FALSE) ||
48 	(list->isOpen == FALSE)) {
49 	    return (NILLNODE);
50     } else {
51 	return ((LstNode)list->curPtr);
52     }
53 }
54 
55