1/* parens.c -- implementation of matching parentheses feature. */
2
3/* Copyright (C) 1987, 1989, 1992-2015, 2017 Free Software Foundation, Inc.
4
5   This file is part of the GNU Readline Library (Readline), a library
6   for reading lines of text with interactive input and history editing.
7
8   Readline is free software: you can redistribute it and/or modify
9   it under the terms of the GNU General Public License as published by
10   the Free Software Foundation, either version 3 of the License, or
11   (at your option) any later version.
12
13   Readline is distributed in the hope that it will be useful,
14   but WITHOUT ANY WARRANTY; without even the implied warranty of
15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16   GNU General Public License for more details.
17
18   You should have received a copy of the GNU General Public License
19   along with Readline.  If not, see <http://www.gnu.org/licenses/>.
20*/
21
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#include "posixselect.h"
42
43#if defined (HAVE_STRING_H)
44#  include <string.h>
45#else /* !HAVE_STRING_H */
46#  include <strings.h>
47#endif /* !HAVE_STRING_H */
48
49#if !defined (strchr) && !defined (__STDC__)
50extern char *strchr (), *strrchr ();
51#endif /* !strchr && !__STDC__ */
52
53#include "readline.h"
54#include "rlprivate.h"
55
56static int find_matching_open PARAMS((char *, int, int));
57
58/* Non-zero means try to blink the matching open parenthesis when the
59   close parenthesis is inserted. */
60int rl_blink_matching_paren = 0;
61
62static int _paren_blink_usec = 500000;
63
64/* Change emacs_standard_keymap to have bindings for paren matching when
65   ON_OR_OFF is 1, change them back to self_insert when ON_OR_OFF == 0. */
66void
67_rl_enable_paren_matching (int on_or_off)
68{
69  if (on_or_off)
70    {
71      /* ([{ */
72      rl_bind_key_in_map (')', rl_insert_close, emacs_standard_keymap);
73      rl_bind_key_in_map (']', rl_insert_close, emacs_standard_keymap);
74      rl_bind_key_in_map ('}', rl_insert_close, emacs_standard_keymap);
75
76#if defined (VI_MODE)
77      /* ([{ */
78      rl_bind_key_in_map (')', rl_insert_close, vi_insertion_keymap);
79      rl_bind_key_in_map (']', rl_insert_close, vi_insertion_keymap);
80      rl_bind_key_in_map ('}', rl_insert_close, vi_insertion_keymap);
81#endif
82    }
83  else
84    {
85      /* ([{ */
86      rl_bind_key_in_map (')', rl_insert, emacs_standard_keymap);
87      rl_bind_key_in_map (']', rl_insert, emacs_standard_keymap);
88      rl_bind_key_in_map ('}', rl_insert, emacs_standard_keymap);
89
90#if defined (VI_MODE)
91      /* ([{ */
92      rl_bind_key_in_map (')', rl_insert, vi_insertion_keymap);
93      rl_bind_key_in_map (']', rl_insert, vi_insertion_keymap);
94      rl_bind_key_in_map ('}', rl_insert, vi_insertion_keymap);
95#endif
96    }
97}
98
99int
100rl_set_paren_blink_timeout (int u)
101{
102  int o;
103
104  o = _paren_blink_usec;
105  if (u > 0)
106    _paren_blink_usec = u;
107  return (o);
108}
109
110int
111rl_insert_close (int count, int 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      USEC_TO_TIMEVAL (_paren_blink_usec, timer);
134
135      orig_point = rl_point;
136      rl_point = match_point;
137      (*rl_redisplay_function) ();
138      ready = select (1, &readfds, (fd_set *)NULL, (fd_set *)NULL, &timer);
139      rl_point = orig_point;
140#else /* !HAVE_SELECT */
141      _rl_insert_char (count, invoking_key);
142#endif /* !HAVE_SELECT */
143    }
144  return 0;
145}
146
147static int
148find_matching_open (char *string, int from, int closer)
149{
150  register int i;
151  int opener, level, delimiter;
152
153  switch (closer)
154    {
155    case ']': opener = '['; break;
156    case '}': opener = '{'; break;
157    case ')': opener = '('; break;
158    default:
159      return (-1);
160    }
161
162  level = 1;			/* The closer passed in counts as 1. */
163  delimiter = 0;		/* Delimited state unknown. */
164
165  for (i = from; i > -1; i--)
166    {
167      if (delimiter && (string[i] == delimiter))
168	delimiter = 0;
169      else if (rl_basic_quote_characters && strchr (rl_basic_quote_characters, string[i]))
170	delimiter = string[i];
171      else if (!delimiter && (string[i] == closer))
172	level++;
173      else if (!delimiter && (string[i] == opener))
174	level--;
175
176      if (!level)
177	break;
178    }
179  return (i);
180}
181