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 #if defined (HAVE_SELECT)
  61 int rl_blink_matching_paren = 1;
  62 #else /* !HAVE_SELECT */
  63 int rl_blink_matching_paren = 0;
  64 #endif /* !HAVE_SELECT */
  65
  66 static int _paren_blink_usec = 500000;
  67
  68 /* Change emacs_standard_keymap to have bindings for paren matching when
  69    ON_OR_OFF is 1, change them back to self_insert when ON_OR_OFF == 0. */
  70 void
  71 _rl_enable_paren_matching (on_or_off)
  72      int on_or_off;
  73 {
  74   if (on_or_off)
  75     {   /* ([{ */
  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       rl_bind_key_in_map ('}', rl_insert_close, emacs_standard_keymap);
  79     }
  80   else
  81     {   /* ([{ */
  82       rl_bind_key_in_map (')', rl_insert, emacs_standard_keymap);
  83       rl_bind_key_in_map (']', rl_insert, emacs_standard_keymap);
  84       rl_bind_key_in_map ('}', rl_insert, emacs_standard_keymap);
  85     }
  86 }
  87
  88 int
  89 rl_set_paren_blink_timeout (u)
  90      int u;
  91 {
  92   int o;
  93
  94   o = _paren_blink_usec;
  95   if (u > 0)
  96     _paren_blink_usec = u;
  97   return (o);
  98 }
  99
 100 int
 101 rl_insert_close (count, invoking_key)
 102      int count, invoking_key;
 103 {
 104   if (rl_explicit_arg || !rl_blink_matching_paren)
 105     _rl_insert_char (count, invoking_key);
 106   else
 107     {
 108 #if defined (HAVE_SELECT)
 109       int orig_point, match_point, ready;
 110       struct timeval timer;
 111       fd_set readfds;
 112
 113       _rl_insert_char (1, invoking_key);
 114       (*rl_redisplay_function) ();
 115       match_point =
 116         find_matching_open (rl_line_buffer, rl_point - 2, invoking_key);
 117
 118       /* Emacs might message or ring the bell here, but I don't. */
 119       if (match_point < 0)
 120         return -1;
 121
 122       FD_ZERO (&readfds);
 123       FD_SET (fileno (rl_instream), &readfds);
 124       USEC_TO_TIMEVAL (_paren_blink_usec, timer);
 125
 126       orig_point = rl_point;
 127       rl_point = match_point;
 128       (*rl_redisplay_function) ();
 129       ready = select (1, &readfds, (fd_set *)NULL, (fd_set *)NULL, &timer);
 130       rl_point = orig_point;
 131 #else /* !HAVE_SELECT */
 132       _rl_insert_char (count, invoking_key);
 133 #endif /* !HAVE_SELECT */
 134     }
 135   return 0;
 136 }
 137
 138 static int
 139 find_matching_open (string, from, closer)
 140      char *string;
 141      int from, closer;
 142 {
 143   register int i;
 144   int opener, level, delimiter;
 145
 146   switch (closer)
 147     {
 148     case ']': opener = '['; break;
 149     case '}': opener = '{'; break;
 150     case ')': opener = '('; break;
 151     default:
 152       return (-1);
 153     }
 154
 155   level = 1;                    /* The closer passed in counts as 1. */
 156   delimiter = 0;                /* Delimited state unknown. */
 157
 158   for (i = from; i > -1; i--)
 159     {
 160       if (delimiter && (string[i] == delimiter))
 161         delimiter = 0;
 162       else if (rl_basic_quote_characters && strchr (rl_basic_quote_characters, string[i]))
 163         delimiter = string[i];
 164       else if (!delimiter && (string[i] == closer))
 165         level++;
 166       else if (!delimiter && (string[i] == opener))
 167         level--;
 168
 169       if (!level)
 170         break;
 171     }
 172   return (i);
 173 }