1 /* $OpenBSD: lstConcatDestroy.c,v 1.12 2022/12/26 19:16:02 jmc Exp $ */
2 /* $NetBSD: lstConcat.c,v 1.6 1996/11/06 17:59:34 christos Exp $ */
3
4 /*
5 * Copyright (c) 1988, 1989, 1990, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * Adam de Boor.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 /*-
37 * listConcat.c --
38 * Function to concatenate two lists.
39 */
40
41 #include "lstInt.h"
42 #include <stddef.h>
43
44 /*-
45 *-----------------------------------------------------------------------
46 * Lst_ConcatDestroy --
47 * Concatenate two lists. The elements of the second list are
48 * destructively added to the first list. If the elements should
49 * be duplicated to avoid confusion with another list, the
50 * Lst_Duplicate function should be called first.
51 *
52 * Side Effects:
53 * The second list is destroyed.
54 *-----------------------------------------------------------------------
55 */
56 void
Lst_ConcatDestroy(Lst l1,Lst l2)57 Lst_ConcatDestroy(Lst l1, Lst l2)
58 {
59 if (l2->firstPtr != NULL) {
60 /*
61 * So long as the second list isn't empty, we just link the
62 * first element of the second list to the last element of the
63 * first list. If the first list isn't empty, we then link the
64 * last element of the list to the first element of the second
65 * list The last element of the second list, if it exists, then
66 * becomes the last element of the first list.
67 */
68 l2->firstPtr->prevPtr = l1->lastPtr;
69 if (l1->lastPtr != NULL)
70 l1->lastPtr->nextPtr = l2->firstPtr;
71 else
72 l1->firstPtr = l2->firstPtr;
73 l1->lastPtr = l2->lastPtr;
74 }
75 }
76
77