lib/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 static int _paren_blink_usec = 500000;
  68
  69 /* Change emacs_standard_keymap to have bindings for paren matching when
  70    ON_OR_OFF is 1, change them back to self_insert when ON_OR_OFF == 0. */
  71 void
  72 _rl_enable_paren_matching (on_or_off)
  73      int on_or_off;
  74 {
  75   if (on_or_off)
  76     {   /* ([{ */
  77       rl_bind_key_in_map (')', rl_insert_close, emacs_standard_keymap);
  78       rl_bind_key_in_map (']', rl_insert_close, emacs_standard_keymap);
  79       rl_bind_key_in_map ('}', rl_insert_close, emacs_standard_keymap);
  80     }
  81   else
  82     {   /* ([{ */
  83       rl_bind_key_in_map (')', rl_insert, emacs_standard_keymap);
  84       rl_bind_key_in_map (']', rl_insert, emacs_standard_keymap);
  85       rl_bind_key_in_map ('}', rl_insert, emacs_standard_keymap);
  86     }
  87 }
  88
  89 int
  90 rl_set_paren_blink_timeout (u)
  91      int u;
  92 {
  93   int o;
  94
  95   o = _paren_blink_usec;
  96   if (u > 0)
  97     _paren_blink_usec = u;
  98   return (o);
  99 }
 100
 101 int
 102 rl_insert_close (count, invoking_key)
 103      int count, invoking_key;
 104 {
 105   if (rl_explicit_arg || !rl_blink_matching_paren)
 106     rl_insert (count, invoking_key);
 107   else
 108     {
 109 #if defined (HAVE_SELECT)
 110       int orig_point, match_point, ready;
 111       struct timeval timer;
 112       fd_set readfds;
 113
 114       rl_insert (1, invoking_key);
 115       (*rl_redisplay_function) ();
 116       match_point =
 117         find_matching_open (rl_line_buffer, rl_point - 2, invoking_key);
 118
 119       /* Emacs might message or ring the bell here, but I don't. */
 120       if (match_point < 0)
 121         return -1;
 122
 123       FD_ZERO (&readfds);
 124       FD_SET (fileno (rl_instream), &readfds);
 125       timer.tv_sec = 0;
 126       timer.tv_usec = _paren_blink_usec;
 127
 128       orig_point = rl_point;
 129       rl_point = match_point;
 130       (*rl_redisplay_function) ();
 131       ready = select (1, &readfds, (fd_set *)NULL, (fd_set *)NULL, &timer);
 132       rl_point = orig_point;
 133 #else /* !HAVE_SELECT */
 134       rl_insert (count, invoking_key);
 135 #endif /* !HAVE_SELECT */
 136     }
 137   return 0;
 138 }
 139
 140 static int
 141 find_matching_open (string, from, closer)
 142      char *string;
 143      int from, closer;
 144 {
 145   register int i;
 146   int opener, level, delimiter;
 147
 148   switch (closer)
 149     {
 150     case ']': opener = '['; break;
 151     case '}': opener = '{'; break;
 152     case ')': opener = '('; break;
 153     default:
 154       return (-1);
 155     }
 156
 157   level = 1;                    /* The closer passed in counts as 1. */
 158   delimiter = 0;                /* Delimited state unknown. */
 159
 160   for (i = from; i > -1; i--)
 161     {
 162       if (delimiter && (string[i] == delimiter))
 163         delimiter = 0;
 164       else if (rl_basic_quote_characters && strchr (rl_basic_quote_characters, string[i]))
 165         delimiter = string[i];
 166       else if (!delimiter && (string[i] == closer))
 167         level++;
 168       else if (!delimiter && (string[i] == opener))
 169         level--;
 170
 171       if (!level)
 172         break;
 173     }
 174   return (i);
 175 }