lstIsAtEnd.c revision 236769
1251607Sdim/* $NetBSD: lstIsAtEnd.c,v 1.13 2008/02/15 21:29:50 christos Exp $ */ 2251607Sdim 3251607Sdim/* 4251607Sdim * Copyright (c) 1988, 1989, 1990, 1993 5251607Sdim * The Regents of the University of California. All rights reserved. 6251607Sdim * 7251607Sdim * This code is derived from software contributed to Berkeley by 8251607Sdim * Adam de Boor. 9251607Sdim * 10251607Sdim * Redistribution and use in source and binary forms, with or without 11251607Sdim * modification, are permitted provided that the following conditions 12251607Sdim * are met: 13251607Sdim * 1. Redistributions of source code must retain the above copyright 14251607Sdim * notice, this list of conditions and the following disclaimer. 15251607Sdim * 2. Redistributions in binary form must reproduce the above copyright 16251607Sdim * notice, this list of conditions and the following disclaimer in the 17251607Sdim * documentation and/or other materials provided with the distribution. 18251607Sdim * 3. Neither the name of the University nor the names of its contributors 19263508Sdim * may be used to endorse or promote products derived from this software 20263508Sdim * without specific prior written permission. 21251607Sdim * 22263508Sdim * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23251607Sdim * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24251607Sdim * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25263508Sdim * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26251607Sdim * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27263508Sdim * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28251607Sdim * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29263508Sdim * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30251607Sdim * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31263508Sdim * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32263508Sdim * SUCH DAMAGE. 33251607Sdim */ 34251607Sdim 35251607Sdim#ifndef MAKE_NATIVE 36251607Sdimstatic char rcsid[] = "$NetBSD: lstIsAtEnd.c,v 1.13 2008/02/15 21:29:50 christos Exp $"; 37251607Sdim#else 38251607Sdim#include <sys/cdefs.h> 39251607Sdim#ifndef lint 40251607Sdim#if 0 41251607Sdimstatic char sccsid[] = "@(#)lstIsAtEnd.c 8.1 (Berkeley) 6/6/93"; 42251607Sdim#else 43251607Sdim__RCSID("$NetBSD: lstIsAtEnd.c,v 1.13 2008/02/15 21:29:50 christos Exp $"); 44251607Sdim#endif 45251607Sdim#endif /* not lint */ 46251607Sdim#endif 47251607Sdim 48251607Sdim/*- 49251607Sdim * LstIsAtEnd.c -- 50251607Sdim * Tell if the current node is at the end of the list. 51251607Sdim * The sequential functions access the list in a slightly different way. 52251607Sdim * CurPtr points to their idea of the current node in the list and they 53251607Sdim * access the list based on it. Because the list is circular, Lst_Next 54251607Sdim * and Lst_Prev will go around the list forever. Lst_IsAtEnd must be 55251607Sdim * used to determine when to stop. 56251607Sdim */ 57251607Sdim 58251607Sdim#include "lstInt.h" 59251607Sdim 60251607Sdim/*- 61263508Sdim *----------------------------------------------------------------------- 62263508Sdim * Lst_IsAtEnd -- 63251607Sdim * Return true if have reached the end of the given list. 64251607Sdim * 65251607Sdim * Results: 66251607Sdim * TRUE if at the end of the list (this includes the list not being 67251607Sdim * open or being invalid) or FALSE if not. We return TRUE if the list 68251607Sdim * is invalid or unopend so as to cause the caller to exit its loop 69251607Sdim * asap, the assumption being that the loop is of the form 70251607Sdim * while (!Lst_IsAtEnd (l)) { 71251607Sdim * ... 72251607Sdim * } 73251607Sdim * 74251607Sdim * Side Effects: 75251607Sdim * None. 76251607Sdim * 77251607Sdim *----------------------------------------------------------------------- 78251607Sdim */ 79263508SdimBoolean 80251607SdimLst_IsAtEnd(Lst l) 81263508Sdim{ 82263508Sdim List list = l; 83263508Sdim 84263508Sdim return (!LstValid (l) || !list->isOpen || 85263508Sdim (list->atEnd == Head) || (list->atEnd == Tail)); 86251607Sdim} 87251607Sdim 88263508Sdim