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/*
* Copyright (c) 1988, 1989, 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Adam de Boor.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id$
*/
#ifndef lint
static char sccsid[] = "@(#)lstOpen.c 8.1 (Berkeley) 6/6/93";
#endif /* not lint */
/*-
* LstOpen.c --
* Open a list for sequential access. The sequential functions access the
* list in a slightly different way. CurPtr points to their idea of the
* current node in the list and they access the list based on it.
* If the list is circular, Lst_Next and Lst_Prev will go around
* the list forever. Lst_IsAtEnd must be used to determine when to stop.
*/
#include "lstInt.h"
/*-
*-----------------------------------------------------------------------
* Lst_Open --
* Open a list for sequential access. A list can still be searched,
* etc., without confusing these functions.
*
* Results:
* SUCCESS or FAILURE.
*
* Side Effects:
* isOpen is set TRUE and curPtr is set to NilListNode so the
* other sequential functions no it was just opened and can choose
* the first element accessed based on this.
*
*-----------------------------------------------------------------------
*/
ReturnStatus
Lst_Open (l)
register Lst l;
{
if (LstValid (l) == FALSE) {
return (FAILURE);
}
((List) l)->isOpen = TRUE;
((List) l)->atEnd = LstIsEmpty (l) ? Head : Unknown;
((List) l)->curPtr = NilListNode;
return (SUCCESS);
}
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