1/*
2 * Copyright (C) 1984-2012  Mark Nudelman
3 * Modified for use with illumos by Garrett D'Amore.
4 * Copyright 2014 Garrett D'Amore <garrett@damore.org>
5 *
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Less License, as specified in the README file.
8 *
9 * For more information, see the README file.
10 */
11
12/*
13 * Routines to perform bracket matching functions.
14 */
15
16#include "less.h"
17#include "position.h"
18
19/*
20 * Try to match the n-th open bracket
21 *  which appears in the top displayed line (forwdir),
22 * or the n-th close bracket
23 *  which appears in the bottom displayed line (!forwdir).
24 * The characters which serve as "open bracket" and
25 * "close bracket" are given.
26 */
27void
28match_brac(int obrac, int cbrac, int forwdir, int n)
29{
30	int c;
31	int nest;
32	off_t pos;
33	int (*chget)(void);
34
35	/*
36	 * Seek to the line containing the open bracket.
37	 * This is either the top or bottom line on the screen,
38	 * depending on the type of bracket.
39	 */
40	pos = position((forwdir) ? TOP : BOTTOM);
41	if (pos == -1 || ch_seek(pos)) {
42		if (forwdir)
43			error("Nothing in top line", NULL);
44		else
45			error("Nothing in bottom line", NULL);
46		return;
47	}
48
49	/*
50	 * Look thru the line to find the open bracket to match.
51	 */
52	do {
53		if ((c = ch_forw_get()) == '\n' || c == EOI) {
54			if (forwdir)
55				error("No bracket in top line", NULL);
56			else
57				error("No bracket in bottom line", NULL);
58			return;
59		}
60	} while (c != obrac || --n > 0);
61
62	/*
63	 * Position the file just "after" the open bracket
64	 * (in the direction in which we will be searching).
65	 * If searching forward, we are already after the bracket.
66	 * If searching backward, skip back over the open bracket.
67	 */
68	if (!forwdir)
69		(void) ch_back_get();
70
71	/*
72	 * Search the file for the matching bracket.
73	 */
74	chget = (forwdir) ? ch_forw_get : ch_back_get;
75	nest = 0;
76	while ((c = (*chget)()) != EOI) {
77		if (c == obrac) {
78			if (nest == INT_MAX)
79				break;
80			nest++;
81		} else if (c == cbrac && --nest < 0) {
82			/*
83			 * Found the matching bracket.
84			 * If searching backward, put it on the top line.
85			 * If searching forward, put it on the bottom line.
86			 */
87			jump_line_loc(ch_tell(), forwdir ? -1 : 1);
88			return;
89		}
90	}
91	error("No matching bracket", NULL);
92}
93