1/*	$NetBSD: lstOpen.c,v 1.12 2008/12/13 15:19:29 dsl Exp $	*/
2
3/*
4 * Copyright (c) 1988, 1989, 1990, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Adam de Boor.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#ifndef MAKE_NATIVE
36static char rcsid[] = "$NetBSD: lstOpen.c,v 1.12 2008/12/13 15:19:29 dsl Exp $";
37#else
38#include <sys/cdefs.h>
39#ifndef lint
40#if 0
41static char sccsid[] = "@(#)lstOpen.c	8.1 (Berkeley) 6/6/93";
42#else
43__RCSID("$NetBSD: lstOpen.c,v 1.12 2008/12/13 15:19:29 dsl Exp $");
44#endif
45#endif /* not lint */
46#endif
47
48/*-
49 * LstOpen.c --
50 *	Open a list for sequential access. The sequential functions access the
51 *	list in a slightly different way. CurPtr points to their idea of the
52 *	current node in the list and they access the list based on it.
53 *	If the list is circular, Lst_Next and Lst_Prev will go around
54 *	the list forever. Lst_IsAtEnd must be used to determine when to stop.
55 */
56
57#include	"lstInt.h"
58
59/*-
60 *-----------------------------------------------------------------------
61 * Lst_Open --
62 *	Open a list for sequential access. A list can still be searched,
63 *	etc., without confusing these functions.
64 *
65 * Results:
66 *	SUCCESS or FAILURE.
67 *
68 * Side Effects:
69 *	isOpen is set TRUE and curPtr is set to NULL so the
70 *	other sequential functions no it was just opened and can choose
71 *	the first element accessed based on this.
72 *
73 *-----------------------------------------------------------------------
74 */
75ReturnStatus
76Lst_Open(Lst l)
77{
78	if (LstValid (l) == FALSE) {
79		return (FAILURE);
80	}
81	(l)->isOpen = TRUE;
82	(l)->atEnd = LstIsEmpty (l) ? Head : Unknown;
83	(l)->curPtr = NULL;
84
85	return (SUCCESS);
86}
87
88