readline/parens.c

   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__)
  59 extern char *strchr (), *strrchr ();
  60 #endif /* !strchr && !__STDC__ */
  61
  62 #include "readline.h"
  63 #include "rlprivate.h"
  64
  65 static 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)
  70 int rl_blink_matching_paren = 1;
  71 #else /* !HAVE_SELECT */
  72 int rl_blink_matching_paren = 0;
  73 #endif /* !HAVE_SELECT */
  74
  75 static 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. */
  79 void
  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
  97 int
  98 rl_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
 109 int
 110 rl_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
 148 static int
 149 find_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 }