1/* parens.c -- Implementation of matching parentheses feature. */
2
3/* Copyright (C) 1987, 1989, 1992 Free Software Foundation, Inc.
4
5   This file is part of the GNU Readline Library, a library for
6   reading lines of text with interactive input and history editing.
7
8   The GNU Readline Library is free software; you can redistribute it
9   and/or modify it under the terms of the GNU General Public License
10   as published by the Free Software Foundation; either version 2, or
11   (at your option) any later version.
12
13   The GNU Readline Library is distributed in the hope that it will be
14   useful, but WITHOUT ANY WARRANTY; without even the implied warranty
15   of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16   GNU General Public License for more details.
17
18   The GNU General Public License is often shipped with GNU software, and
19   is generally kept in a file called COPYING or LICENSE.  If you do not
20   have a copy of the license, write to the Free Software Foundation,
21   59 Temple Place, Suite 330, Boston, MA 02111 USA. */
22#define READLINE_LIBRARY
23
24#if defined (__TANDEM)
25#  include <floss.h>
26#endif
27
28#include "rlconf.h"
29
30#if defined (HAVE_CONFIG_H)
31#  include <config.h>
32#endif
33
34#include <stdio.h>
35#include <sys/types.h>
36
37#if defined (HAVE_UNISTD_H)
38#  include <unistd.h>
39#endif
40
41#if defined (FD_SET) && !defined (HAVE_SELECT)
42#  define HAVE_SELECT
43#endif
44
45#if defined (HAVE_SELECT)
46#  include <sys/time.h>
47#endif /* HAVE_SELECT */
48#if defined (HAVE_SYS_SELECT_H)
49#  include <sys/select.h>
50#endif
51
52#if defined (HAVE_STRING_H)
53#  include <string.h>
54#else /* !HAVE_STRING_H */
55#  include <strings.h>
56#endif /* !HAVE_STRING_H */
57
58#if !defined (strchr) && !defined (__STDC__)
59extern char *strchr (), *strrchr ();
60#endif /* !strchr && !__STDC__ */
61
62#include "readline.h"
63#include "rlprivate.h"
64
65static int find_matching_open PARAMS((char *, int, int));
66
67/* Non-zero means try to blink the matching open parenthesis when the
68   close parenthesis is inserted. */
69#if defined (HAVE_SELECT)
70int rl_blink_matching_paren = 1;
71#else /* !HAVE_SELECT */
72int rl_blink_matching_paren = 0;
73#endif /* !HAVE_SELECT */
74
75static int _paren_blink_usec = 500000;
76
77/* Change emacs_standard_keymap to have bindings for paren matching when
78   ON_OR_OFF is 1, change them back to self_insert when ON_OR_OFF == 0. */
79void
80_rl_enable_paren_matching (on_or_off)
81     int on_or_off;
82{
83  if (on_or_off)
84    {	/* ([{ */
85      rl_bind_key_in_map (')', rl_insert_close, emacs_standard_keymap);
86      rl_bind_key_in_map (']', rl_insert_close, emacs_standard_keymap);
87      rl_bind_key_in_map ('}', rl_insert_close, emacs_standard_keymap);
88    }
89  else
90    {	/* ([{ */
91      rl_bind_key_in_map (')', rl_insert, emacs_standard_keymap);
92      rl_bind_key_in_map (']', rl_insert, emacs_standard_keymap);
93      rl_bind_key_in_map ('}', rl_insert, emacs_standard_keymap);
94    }
95}
96
97int
98rl_set_paren_blink_timeout (u)
99     int u;
100{
101  int o;
102
103  o = _paren_blink_usec;
104  if (u > 0)
105    _paren_blink_usec = u;
106  return (o);
107}
108
109int
110rl_insert_close (count, invoking_key)
111     int count, invoking_key;
112{
113  if (rl_explicit_arg || !rl_blink_matching_paren)
114    _rl_insert_char (count, invoking_key);
115  else
116    {
117#if defined (HAVE_SELECT)
118      int orig_point, match_point, ready;
119      struct timeval timer;
120      fd_set readfds;
121
122      _rl_insert_char (1, invoking_key);
123      (*rl_redisplay_function) ();
124      match_point =
125	find_matching_open (rl_line_buffer, rl_point - 2, invoking_key);
126
127      /* Emacs might message or ring the bell here, but I don't. */
128      if (match_point < 0)
129	return -1;
130
131      FD_ZERO (&readfds);
132      FD_SET (fileno (rl_instream), &readfds);
133      timer.tv_sec = 0;
134      timer.tv_usec = _paren_blink_usec;
135
136      orig_point = rl_point;
137      rl_point = match_point;
138      (*rl_redisplay_function) ();
139      ready = select (1, &readfds, (fd_set *)NULL, (fd_set *)NULL, &timer);
140      rl_point = orig_point;
141#else /* !HAVE_SELECT */
142      _rl_insert_char (count, invoking_key);
143#endif /* !HAVE_SELECT */
144    }
145  return 0;
146}
147
148static int
149find_matching_open (string, from, closer)
150     char *string;
151     int from, closer;
152{
153  register int i;
154  int opener, level, delimiter;
155
156  switch (closer)
157    {
158    case ']': opener = '['; break;
159    case '}': opener = '{'; break;
160    case ')': opener = '('; break;
161    default:
162      return (-1);
163    }
164
165  level = 1;			/* The closer passed in counts as 1. */
166  delimiter = 0;		/* Delimited state unknown. */
167
168  for (i = from; i > -1; i--)
169    {
170      if (delimiter && (string[i] == delimiter))
171	delimiter = 0;
172      else if (rl_basic_quote_characters && strchr (rl_basic_quote_characters, string[i]))
173	delimiter = string[i];
174      else if (!delimiter && (string[i] == closer))
175	level++;
176      else if (!delimiter && (string[i] == opener))
177	level--;
178
179      if (!level)
180	break;
181    }
182  return (i);
183}
184