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