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/* $OpenPackages$ */
/* $OpenBSD: lstInsert.c,v 1.16 2004/04/07 13:11:36 espie Exp $ */
/* $NetBSD: lstInsert.c,v 1.5 1996/11/06 17:59:44 christos Exp $ */
/*
* 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. 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.
*/
/*-
* LstInsert.c --
* Insert a new datum before an old one
*/
#include "lstInt.h"
#include <sys/types.h>
#include <stdlib.h>
#include "memory.h"
/*-
*-----------------------------------------------------------------------
* Lst_Insert --
* Insert a new node with the given piece of data before the given
* node in the given list.
*
* Side Effects:
* the firstPtr field will be changed if ln is the first node in the
* list.
*
*-----------------------------------------------------------------------
*/
void
Lst_Insert(Lst l, LstNode before, void *d)
{
LstNode nLNode; /* new lnode for d */
if (before == NULL && !Lst_IsEmpty(l))
return;
if (before != NULL && Lst_IsEmpty(l))
return;
PAlloc(nLNode, LstNode);
nLNode->datum = d;
if (before == NULL) {
nLNode->prevPtr = nLNode->nextPtr = NULL;
l->firstPtr = l->lastPtr = nLNode;
} else {
nLNode->prevPtr = before->prevPtr;
nLNode->nextPtr = before;
if (nLNode->prevPtr != NULL)
nLNode->prevPtr->nextPtr = nLNode;
before->prevPtr = nLNode;
if (before == l->firstPtr)
l->firstPtr = nLNode;
}
}
void
Lst_AtFront(Lst l, void *d)
{
LstNode ln;
PAlloc(ln, LstNode);
ln->datum = d;
ln->nextPtr = l->firstPtr;
ln->prevPtr = NULL;
if (l->firstPtr == NULL)
l->lastPtr = ln;
else
l->firstPtr->prevPtr = ln;
l->firstPtr = ln;
}
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