readline/parens.c

   1 /* parens.c -- implementation of matching parentheses feature. */
   2
   3 /* Copyright (C) 1987, 1989, 1992-2009 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 (on_or_off)
  68      int on_or_off;
  69 {
  70   if (on_or_off)
  71     {
  72       /* ([{ */
  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       rl_bind_key_in_map ('}', rl_insert_close, emacs_standard_keymap);
  76
  77 #if defined (VI_MODE)
  78       /* ([{ */
  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       rl_bind_key_in_map ('}', rl_insert_close, vi_insertion_keymap);
  82 #endif
  83     }
  84   else
  85     {
  86       /* ([{ */
  87       rl_bind_key_in_map (')', rl_insert, emacs_standard_keymap);
  88       rl_bind_key_in_map (']', rl_insert, emacs_standard_keymap);
  89       rl_bind_key_in_map ('}', rl_insert, emacs_standard_keymap);
  90
  91 #if defined (VI_MODE)
  92       /* ([{ */
  93       rl_bind_key_in_map (')', rl_insert, vi_insertion_keymap);
  94       rl_bind_key_in_map (']', rl_insert, vi_insertion_keymap);
  95       rl_bind_key_in_map ('}', rl_insert, vi_insertion_keymap);
  96 #endif
  97     }
  98 }
  99
 100 int
 101 rl_set_paren_blink_timeout (u)
 102      int u;
 103 {
 104   int o;
 105
 106   o = _paren_blink_usec;
 107   if (u > 0)
 108     _paren_blink_usec = u;
 109   return (o);
 110 }
 111
 112 int
 113 rl_insert_close (count, invoking_key)
 114      int count, invoking_key;
 115 {
 116   if (rl_explicit_arg || !rl_blink_matching_paren)
 117     _rl_insert_char (count, invoking_key);
 118   else
 119     {
 120 #if defined (HAVE_SELECT)
 121       int orig_point, match_point, ready;
 122       struct timeval timer;
 123       fd_set readfds;
 124
 125       _rl_insert_char (1, invoking_key);
 126       (*rl_redisplay_function) ();
 127       match_point =
 128         find_matching_open (rl_line_buffer, rl_point - 2, invoking_key);
 129
 130       /* Emacs might message or ring the bell here, but I don't. */
 131       if (match_point < 0)
 132         return 1;
 133
 134       FD_ZERO (&readfds);
 135       FD_SET (fileno (rl_instream), &readfds);
 136       USEC_TO_TIMEVAL (_paren_blink_usec, timer);
 137
 138       orig_point = rl_point;
 139       rl_point = match_point;
 140       (*rl_redisplay_function) ();
 141       ready = select (1, &readfds, (fd_set *)NULL, (fd_set *)NULL, &timer);
 142       rl_point = orig_point;
 143 #else /* !HAVE_SELECT */
 144       _rl_insert_char (count, invoking_key);
 145 #endif /* !HAVE_SELECT */
 146     }
 147   return 0;
 148 }
 149
 150 static int
 151 find_matching_open (string, from, closer)
 152      char *string;
 153      int from, closer;
 154 {
 155   register int i;
 156   int opener, level, delimiter;
 157
 158   switch (closer)
 159     {
 160     case ']': opener = '['; break;
 161     case '}': opener = '{'; break;
 162     case ')': opener = '('; break;
 163     default:
 164       return (-1);
 165     }
 166
 167   level = 1;                    /* The closer passed in counts as 1. */
 168   delimiter = 0;                /* Delimited state unknown. */
 169
 170   for (i = from; i > -1; i--)
 171     {
 172       if (delimiter && (string[i] == delimiter))
 173         delimiter = 0;
 174       else if (rl_basic_quote_characters && strchr (rl_basic_quote_characters, string[i]))
 175         delimiter = string[i];
 176       else if (!delimiter && (string[i] == closer))
 177         level++;
 178       else if (!delimiter && (string[i] == opener))
 179         level--;
 180
 181       if (!level)
 182         break;
 183     }
 184   return (i);
 185 }