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/* $OpenPackages$ */
/* $OpenBSD: lstConcat.c,v 1.15 2003/06/03 02:56:12 millert Exp $ */
/* $NetBSD: lstConcat.c,v 1.6 1996/11/06 17:59:34 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.
*/
/*-
* listConcat.c --
* Function to copy a list and append it to another.
*/
#include "lstInt.h"
#include <sys/types.h>
#include <stddef.h>
#include "memory.h"
/*-
*-----------------------------------------------------------------------
* Lst_Concat --
* Concatenate two lists. New elements are created to hold the data
* elements but the elements themselves are not copied.
* If the elements themselves should be duplicated to avoid
* confusion with another list, the Lst_Duplicate function
* should be called first.
*
* Side Effects:
* New elements are created and appended the the first list.
*-----------------------------------------------------------------------
*/
void
Lst_Concat(l1, l2)
Lst l1; /* The list to which l2 is to be appended */
Lst l2; /* The list to append to l1 */
{
LstNode ln; /* original LstNode */
LstNode nln; /* new LstNode */
LstNode last; /* the last element in the list. Keeps
* bookkeeping until the end */
if (l2->firstPtr != NULL) {
/* The loop simply goes through the entire second list creating new
* LstNodes and filling in the nextPtr, and prevPtr to fit into l1
* and its datum field from the datum field of the corresponding
* element in l2. The 'last' node follows the last of the new nodes
* along until the entire l2 has been appended. Only then does the
* bookkeeping catch up with the changes. During the first iteration
* of the loop, if 'last' is NULL, the first list must have been empty
* so the newly-created node is made the first node of the list. */
for (last = l1->lastPtr, ln = l2->firstPtr;
ln != NULL;
ln = ln->nextPtr) {
PAlloc(nln, LstNode);
nln->datum = ln->datum;
if (last != NULL)
last->nextPtr = nln;
else
l1->firstPtr = nln;
nln->prevPtr = last;
last = nln;
}
/* Finish bookkeeping. The last new element becomes the last element
* of l1. */
l1->lastPtr = last;
last->nextPtr = NULL;
}
}
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