parens.c revision 58310 
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#include "rlconf.h"
25
26#if defined (HAVE_CONFIG_H)
27#  include <config.h>
28#endif
29
30#include <stdio.h>
31#include <sys/types.h>
32
33#if defined (FD_SET) && !defined (HAVE_SELECT)
34#  define HAVE_SELECT
35#endif
36
37#if defined (HAVE_SELECT)
38#  include <sys/time.h>
39#endif /* HAVE_SELECT */
40#if defined (HAVE_SYS_SELECT_H)
41#  include <sys/select.h>
42#endif
43
44#if defined (HAVE_STRING_H)
45#  include <string.h>
46#else /* !HAVE_STRING_H */
47#  include <strings.h>
48#endif /* !HAVE_STRING_H */
49
50#if !defined (strchr) && !defined (__STDC__)
51extern char *strchr (), *strrchr ();
52#endif /* !strchr && !__STDC__ */
53
54#include "readline.h"
55#include "rlprivate.h"
56
57static int find_matching_open __P((char *, int, int));
58
59/* Non-zero means try to blink the matching open parenthesis when the
60   close parenthesis is inserted. */
61#if defined (HAVE_SELECT)
62int rl_blink_matching_paren = 1;
63#else /* !HAVE_SELECT */
64int rl_blink_matching_paren = 0;
65#endif /* !HAVE_SELECT */
66
67/* Change emacs_standard_keymap to have bindings for paren matching when
68   ON_OR_OFF is 1, change them back to self_insert when ON_OR_OFF == 0. */
69void
70_rl_enable_paren_matching (on_or_off)
71     int on_or_off;
72{
73  if (on_or_off)
74    {	/* ([{ */
75      rl_bind_key_in_map (')', rl_insert_close, emacs_standard_keymap);
76      rl_bind_key_in_map (']', rl_insert_close, emacs_standard_keymap);
77      rl_bind_key_in_map ('}', rl_insert_close, emacs_standard_keymap);
78    }
79  else
80    {	/* ([{ */
81      rl_bind_key_in_map (')', rl_insert, emacs_standard_keymap);
82      rl_bind_key_in_map (']', rl_insert, emacs_standard_keymap);
83      rl_bind_key_in_map ('}', rl_insert, emacs_standard_keymap);
84    }
85}
86
87int
88rl_insert_close (count, invoking_key)
89     int count, invoking_key;
90{
91  if (rl_explicit_arg || !rl_blink_matching_paren)
92    rl_insert (count, invoking_key);
93  else
94    {
95#if defined (HAVE_SELECT)
96      int orig_point, match_point, ready;
97      struct timeval timer;
98      fd_set readfds;
99
100      rl_insert (1, invoking_key);
101      (*rl_redisplay_function) ();
102      match_point =
103	find_matching_open (rl_line_buffer, rl_point - 2, invoking_key);
104
105      /* Emacs might message or ring the bell here, but I don't. */
106      if (match_point < 0)
107	return -1;
108
109      FD_ZERO (&readfds);
110      FD_SET (fileno (rl_instream), &readfds);
111      timer.tv_sec = 0;
112      timer.tv_usec = 500000;
113
114      orig_point = rl_point;
115      rl_point = match_point;
116      (*rl_redisplay_function) ();
117      ready = select (1, &readfds, (fd_set *)NULL, (fd_set *)NULL, &timer);
118      rl_point = orig_point;
119#else /* !HAVE_SELECT */
120      rl_insert (count, invoking_key);
121#endif /* !HAVE_SELECT */
122    }
123  return 0;
124}
125
126static int
127find_matching_open (string, from, closer)
128     char *string;
129     int from, closer;
130{
131  register int i;
132  int opener, level, delimiter;
133
134  switch (closer)
135    {
136    case ']': opener = '['; break;
137    case '}': opener = '{'; break;
138    case ')': opener = '('; break;
139    default:
140      return (-1);
141    }
142
143  level = 1;			/* The closer passed in counts as 1. */
144  delimiter = 0;		/* Delimited state unknown. */
145
146  for (i = from; i > -1; i--)
147    {
148      if (delimiter && (string[i] == delimiter))
149	delimiter = 0;
150      else if (rl_basic_quote_characters && strchr (rl_basic_quote_characters, string[i]))
151	delimiter = string[i];
152      else if (!delimiter && (string[i] == closer))
153	level++;
154      else if (!delimiter && (string[i] == opener))
155	level--;
156
157      if (!level)
158	break;
159    }
160  return (i);
161}
162