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 (FD_SET) && !defined (HAVE_SELECT)
  34 #  define HAVE_SELECT
  35 #endif
  36
  37 #if defined (HAVE_SELECT)
  38 #  include <sys/time.h>
  39 #endif /* HAVE_SELECT */
  40 #if defined (HAVE_SYS_SELECT_H)
  41 #  include <sys/select.h>
  42 #endif
  43
  44 #if defined (HAVE_STRING_H)
  45 #  include <string.h>
  46 #else /* !HAVE_STRING_H */
  47 #  include <strings.h>
  48 #endif /* !HAVE_STRING_H */
  49
  50 #if !defined (strchr) && !defined (__STDC__)
  51 extern char *strchr (), *strrchr ();
  52 #endif /* !strchr && !__STDC__ */
  53
  54 #include "readline.h"
  55 #include "rlprivate.h"
  56
  57 static int find_matching_open __P((char *, int, int));
  58
  59 /* Non-zero means try to blink the matching open parenthesis when the
  60    close parenthesis is inserted. */
  61 #if defined (HAVE_SELECT)
  62 int rl_blink_matching_paren = 1;
  63 #else /* !HAVE_SELECT */
  64 int rl_blink_matching_paren = 0;
  65 #endif /* !HAVE_SELECT */
  66
  67 /* Change emacs_standard_keymap to have bindings for paren matching when
  68    ON_OR_OFF is 1, change them back to self_insert when ON_OR_OFF == 0. */
  69 void
  70 _rl_enable_paren_matching (on_or_off)
  71      int on_or_off;
  72 {
  73   if (on_or_off)
  74     {   /* ([{ */
  75       rl_bind_key_in_map (')', rl_insert_close, emacs_standard_keymap);
  76       rl_bind_key_in_map (']', rl_insert_close, emacs_standard_keymap);
  77       rl_bind_key_in_map ('}', rl_insert_close, emacs_standard_keymap);
  78     }
  79   else
  80     {   /* ([{ */
  81       rl_bind_key_in_map (')', rl_insert, emacs_standard_keymap);
  82       rl_bind_key_in_map (']', rl_insert, emacs_standard_keymap);
  83       rl_bind_key_in_map ('}', rl_insert, emacs_standard_keymap);
  84     }
  85 }
  86
  87 int
  88 rl_insert_close (count, invoking_key)
  89      int count, invoking_key;
  90 {
  91   if (rl_explicit_arg || !rl_blink_matching_paren)
  92     rl_insert (count, invoking_key);
  93   else
  94     {
  95 #if defined (HAVE_SELECT)
  96       int orig_point, match_point, ready;
  97       struct timeval timer;
  98       fd_set readfds;
  99
 100       rl_insert (1, invoking_key);
 101       (*rl_redisplay_function) ();
 102       match_point =
 103         find_matching_open (rl_line_buffer, rl_point - 2, invoking_key);
 104
 105       /* Emacs might message or ring the bell here, but I don't. */
 106       if (match_point < 0)
 107         return -1;
 108
 109       FD_ZERO (&readfds);
 110       FD_SET (fileno (rl_instream), &readfds);
 111       timer.tv_sec = 0;
 112       timer.tv_usec = 500000;
 113
 114       orig_point = rl_point;
 115       rl_point = match_point;
 116       (*rl_redisplay_function) ();
 117       ready = select (1, &readfds, (fd_set *)NULL, (fd_set *)NULL, &timer);
 118       rl_point = orig_point;
 119 #else /* !HAVE_SELECT */
 120       rl_insert (count, invoking_key);
 121 #endif /* !HAVE_SELECT */
 122     }
 123   return 0;
 124 }
 125
 126 static int
 127 find_matching_open (string, from, closer)
 128      char *string;
 129      int from, closer;
 130 {
 131   register int i;
 132   int opener, level, delimiter;
 133
 134   switch (closer)
 135     {
 136     case ']': opener = '['; break;
 137     case '}': opener = '{'; break;
 138     case ')': opener = '('; break;
 139     default:
 140       return (-1);
 141     }
 142
 143   level = 1;                    /* The closer passed in counts as 1. */
 144   delimiter = 0;                /* Delimited state unknown. */
 145
 146   for (i = from; i > -1; i--)
 147     {
 148       if (delimiter && (string[i] == delimiter))
 149         delimiter = 0;
 150       else if (rl_basic_quote_characters && strchr (rl_basic_quote_characters, string[i]))
 151         delimiter = string[i];
 152       else if (!delimiter && (string[i] == closer))
 153         level++;
 154       else if (!delimiter && (string[i] == opener))
 155         level--;
 156
 157       if (!level)
 158         break;
 159     }
 160   return (i);
 161 }