-
Notifications
You must be signed in to change notification settings - Fork 84
/
brac.c
117 lines (108 loc) · 3.37 KB
/
brac.c
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
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
/*
* Copyright (c) 1984,1985,1989,1994,1995,1996,1999 Mark Nudelman
* All rights reserved.
*
* 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 in the documentation and/or other materials provided with
* the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
/*
* Routines to perform bracket matching functions.
*/
#include "less.h"
#include "position.h"
/*
* Try to match the n-th open bracket
* which appears in the top displayed line (forwdir),
* or the n-th close bracket
* which appears in the bottom displayed line (!forwdir).
* The characters which serve as "open bracket" and
* "close bracket" are given.
*/
public void
match_brac(obrac, cbrac, forwdir, n)
register int obrac;
register int cbrac;
int forwdir;
int n;
{
register int c;
register int nest;
POSITION pos;
int (*chget)();
extern int ch_forw_get(), ch_back_get();
/*
* Seek to the line containing the open bracket.
* This is either the top or bottom line on the screen,
* depending on the type of bracket.
*/
pos = position((forwdir) ? TOP : BOTTOM);
if (pos == NULL_POSITION || ch_seek(pos))
{
if (forwdir)
error("Nothing in top line", NULL_PARG);
else
error("Nothing in bottom line", NULL_PARG);
return;
}
/*
* Look thru the line to find the open bracket to match.
*/
do
{
if ((c = ch_forw_get()) == '\n' || c == EOI)
{
if (forwdir)
error("No bracket in top line", NULL_PARG);
else
error("No bracket in bottom line", NULL_PARG);
return;
}
} while (c != obrac || --n > 0);
/*
* Position the file just "after" the open bracket
* (in the direction in which we will be searching).
* If searching forward, we are already after the bracket.
* If searching backward, skip back over the open bracket.
*/
if (!forwdir)
(void) ch_back_get();
/*
* Search the file for the matching bracket.
*/
chget = (forwdir) ? ch_forw_get : ch_back_get;
nest = 0;
while ((c = (*chget)()) != EOI)
{
if (c == obrac)
nest++;
else if (c == cbrac && --nest < 0)
{
/*
* Found the matching bracket.
* If searching backward, put it on the top line.
* If searching forward, put it on the bottom line.
*/
jump_line_loc(ch_tell(), forwdir ? -1 : 1);
return;
}
}
error("No matching bracket", NULL_PARG);
}