1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
|
/* $OpenBSD: lstConcat.c,v 1.20 2010/07/19 19:46:44 espie 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 to the first list.
*-----------------------------------------------------------------------
*/
void
Lst_Concat(Lst l1, Lst l2)
{
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;
}
}
|
