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 #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 (HAVE_UNISTD_H)
  34 #  include <unistd.h>
  35 #endif
  36
  37 #if defined (FD_SET) && !defined (HAVE_SELECT)
  38 #  define HAVE_SELECT
  39 #endif
  40
  41 #if defined (HAVE_SELECT)
  42 #  include <sys/time.h>
  43 #endif /* HAVE_SELECT */
  44 #if defined (HAVE_SYS_SELECT_H)
  45 #  include <sys/select.h>
  46 #endif
  47
  48 #if defined (HAVE_STRING_H)
  49 #  include <string.h>
  50 #else /* !HAVE_STRING_H */
  51 #  include <strings.h>
  52 #endif /* !HAVE_STRING_H */
  53
  54 #if !defined (strchr) && !defined (__STDC__)
  55 extern char *strchr (), *strrchr ();
  56 #endif /* !strchr && !__STDC__ */
  57
  58 #include "readline.h"
  59 #include "rlprivate.h"
  60
  61 static int find_matching_open PARAMS((char *, int, int));
  62
  63 /* Non-zero means try to blink the matching open parenthesis when the
  64    close parenthesis is inserted. */
  65 #if defined (HAVE_SELECT)
  66 int rl_blink_matching_paren = 1;
  67 #else /* !HAVE_SELECT */
  68 int rl_blink_matching_paren = 0;
  69 #endif /* !HAVE_SELECT */
  70
  71 static int _paren_blink_usec = 500000;
  72
  73 /* Change emacs_standard_keymap to have bindings for paren matching when
  74    ON_OR_OFF is 1, change them back to self_insert when ON_OR_OFF == 0. */
  75 void
  76 _rl_enable_paren_matching (on_or_off)
  77      int on_or_off;
  78 {
  79   if (on_or_off)
  80     {   /* ([{ */
  81       rl_bind_key_in_map (')', rl_insert_close, emacs_standard_keymap);
  82       rl_bind_key_in_map (']', rl_insert_close, emacs_standard_keymap);
  83       rl_bind_key_in_map ('}', rl_insert_close, emacs_standard_keymap);
  84     }
  85   else
  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 }
  92
  93 int
  94 rl_set_paren_blink_timeout (u)
  95      int u;
  96 {
  97   int o;
  98
  99   o = _paren_blink_usec;
 100   if (u > 0)
 101     _paren_blink_usec = u;
 102   return (o);
 103 }
 104
 105 int
 106 rl_insert_close (count, invoking_key)
 107      int count, invoking_key;
 108 {
 109   if (rl_explicit_arg || !rl_blink_matching_paren)
 110     _rl_insert_char (count, invoking_key);
 111   else
 112     {
 113 #if defined (HAVE_SELECT)
 114       int orig_point, match_point, ready;
 115       struct timeval timer;
 116       fd_set readfds;
 117
 118       _rl_insert_char (1, invoking_key);
 119       (*rl_redisplay_function) ();
 120       match_point =
 121         find_matching_open (rl_line_buffer, rl_point - 2, invoking_key);
 122
 123       /* Emacs might message or ring the bell here, but I don't. */
 124       if (match_point < 0)
 125         return -1;
 126
 127       FD_ZERO (&readfds);
 128       FD_SET (fileno (rl_instream), &readfds);
 129       timer.tv_sec = 0;
 130       timer.tv_usec = _paren_blink_usec;
 131
 132       orig_point = rl_point;
 133       rl_point = match_point;
 134       (*rl_redisplay_function) ();
 135       ready = select (1, &readfds, (fd_set *)NULL, (fd_set *)NULL, &timer);
 136       rl_point = orig_point;
 137 #else /* !HAVE_SELECT */
 138       _rl_insert_char (count, invoking_key);
 139 #endif /* !HAVE_SELECT */
 140     }
 141   return 0;
 142 }
 143
 144 static int
 145 find_matching_open (string, from, closer)
 146      char *string;
 147      int from, closer;
 148 {
 149   register int i;
 150   int opener, level, delimiter;
 151
 152   switch (closer)
 153     {
 154     case ']': opener = '['; break;
 155     case '}': opener = '{'; break;
 156     case ')': opener = '('; break;
 157     default:
 158       return (-1);
 159     }
 160
 161   level = 1;                    /* The closer passed in counts as 1. */
 162   delimiter = 0;                /* Delimited state unknown. */
 163
 164   for (i = from; i > -1; i--)
 165     {
 166       if (delimiter && (string[i] == delimiter))
 167         delimiter = 0;
 168       else if (rl_basic_quote_characters && strchr (rl_basic_quote_characters, string[i]))
 169         delimiter = string[i];
 170       else if (!delimiter && (string[i] == closer))
 171         level++;
 172       else if (!delimiter && (string[i] == opener))
 173         level--;
 174
 175       if (!level)
 176         break;
 177     }
 178   return (i);
 179 }