readline/parens.c

   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__)
  50 extern char *strchr (), *strrchr ();
  51 #endif /* !strchr && !__STDC__ */
  52
  53 #include "readline.h"
  54 #include "rlprivate.h"
  55
  56 static 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. */
  60 int rl_blink_matching_paren = 0;
  61
  62 static 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. */
  66 void
  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
  99 int
 100 rl_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
 110 int
 111 rl_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
 147 static int
 148 find_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 }