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 1, 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    675 Mass Ave, Cambridge, MA 02139, USA. */
  22 #define READLINE_LIBRARY
  23
  24 #include "rlconf.h"
  25
  26 #if !defined (PAREN_MATCHING)
  27 extern int rl_insert ();
  28
  29 int
  30 rl_insert_close (count, invoking_key)
  31      int count, invoking_key;
  32 {
  33   return (rl_insert (count, invoking_key));
  34 }
  35
  36 #else /* PAREN_MATCHING */
  37
  38 #if defined (HAVE_CONFIG_H)
  39 #  include <config.h>
  40 #endif
  41
  42 #include <stdio.h>
  43 #include <sys/types.h>
  44
  45 #if defined (FD_SET) && !defined (HAVE_SELECT)
  46 #  define HAVE_SELECT
  47 #endif
  48
  49 #if defined (HAVE_SELECT)
  50 #  include <sys/time.h>
  51 #endif /* HAVE_SELECT */
  52 #if defined (HAVE_SYS_SELECT_H)
  53 #  include <sys/select.h>
  54 #endif
  55
  56 #if defined (HAVE_STRING_H)
  57 #  include <string.h>
  58 #else /* !HAVE_STRING_H */
  59 #  include <strings.h>
  60 #endif /* !HAVE_STRING_H */
  61
  62 #if !defined (strchr) && !defined (__STDC__)
  63 extern char *strchr (), *strrchr ();
  64 #endif /* !strchr && !__STDC__ */
  65
  66 #include "readline.h"
  67
  68 extern int rl_explicit_arg;
  69
  70 /* Non-zero means try to blink the matching open parenthesis when the
  71    close parenthesis is inserted. */
  72 #if defined (HAVE_SELECT)
  73 int rl_blink_matching_paren = 1;
  74 #else /* !HAVE_SELECT */
  75 int rl_blink_matching_paren = 0;
  76 #endif /* !HAVE_SELECT */
  77
  78 static int find_matching_open ();
  79
  80 int
  81 rl_insert_close (count, invoking_key)
  82      int count, invoking_key;
  83 {
  84   if (rl_explicit_arg || !rl_blink_matching_paren)
  85     rl_insert (count, invoking_key);
  86   else
  87     {
  88 #if defined (HAVE_SELECT)
  89       int orig_point, match_point, ready;
  90       struct timeval timer;
  91       fd_set readfds;
  92
  93       rl_insert (1, invoking_key);
  94       (*rl_redisplay_function) ();
  95       match_point =
  96         find_matching_open (rl_line_buffer, rl_point - 2, invoking_key);
  97
  98       /* Emacs might message or ring the bell here, but I don't. */
  99       if (match_point < 0)
 100         return -1;
 101
 102       FD_ZERO (&readfds);
 103       FD_SET (fileno (rl_instream), &readfds);
 104       timer.tv_sec = 0;
 105       timer.tv_usec = 500000;
 106
 107       orig_point = rl_point;
 108       rl_point = match_point;
 109       (*rl_redisplay_function) ();
 110       ready = select (1, &readfds, (fd_set *)NULL, (fd_set *)NULL, &timer);
 111       rl_point = orig_point;
 112 #else /* !HAVE_SELECT */
 113       rl_insert (count, invoking_key);
 114 #endif /* !HAVE_SELECT */
 115     }
 116   return 0;
 117 }
 118
 119 static int
 120 find_matching_open (string, from, closer)
 121      char *string;
 122      int from, closer;
 123 {
 124   register int i;
 125   int opener, level, delimiter;
 126
 127   switch (closer)
 128     {
 129     case ']': opener = '['; break;
 130     case '}': opener = '{'; break;
 131     case ')': opener = '('; break;
 132     default:
 133       return (-1);
 134     }
 135
 136   level = 1;                    /* The closer passed in counts as 1. */
 137   delimiter = 0;                /* Delimited state unknown. */
 138
 139   for (i = from; i > -1; i--)
 140     {
 141       if (delimiter && (string[i] == delimiter))
 142         delimiter = 0;
 143       else if (rl_basic_quote_characters && strchr (rl_basic_quote_characters, string[i]))
 144         delimiter = string[i];
 145       else if (!delimiter && (string[i] == closer))
 146         level++;
 147       else if (!delimiter && (string[i] == opener))
 148         level--;
 149
 150       if (!level)
 151         break;
 152     }
 153   return (i);
 154 }
 155
 156 #endif /* PAREN_MATCHING */