/* parens.c -- Implementation of matching parentheses feature. *//* Copyright (C) 1987, 1989, 1992 Free Software Foundation, Inc.   This file is part of the GNU Readline Library, a library for   reading lines of text with interactive input and history editing.   The GNU Readline Library is free software; you can redistribute it   and/or modify it under the terms of the GNU General Public License   as published by the Free Software Foundation; either version 2, or   (at your option) any later version.   The GNU Readline Library is distributed in the hope that it will be   useful, but WITHOUT ANY WARRANTY; without even the implied warranty   of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the   GNU General Public License for more details.   The GNU General Public License is often shipped with GNU software, and   is generally kept in a file called COPYING or LICENSE.  If you do not   have a copy of the license, write to the Free Software Foundation,   59 Temple Place, Suite 330, Boston, MA 02111 USA. */#define READLINE_LIBRARY#include "rlconf.h"#if defined (HAVE_CONFIG_H)#  include <config.h>#endif#include <stdio.h>#include <sys/types.h>#if defined (HAVE_UNISTD_H)#  include <unistd.h>#endif#if defined (FD_SET) && !defined (HAVE_SELECT)#  define HAVE_SELECT#endif#if defined (HAVE_SELECT)#  include <sys/time.h>#endif /* HAVE_SELECT */#if defined (HAVE_SYS_SELECT_H)#  include <sys/select.h>#endif#if defined (HAVE_STRING_H)#  include <string.h>#else /* !HAVE_STRING_H */#  include <strings.h>#endif /* !HAVE_STRING_H */#if !defined (strchr) && !defined (__STDC__)extern char *strchr (), *strrchr ();#endif /* !strchr && !__STDC__ */#include "readline.h"#include "rlprivate.h"static int find_matching_open PARAMS((char *, int, int));/* Non-zero means try to blink the matching open parenthesis when the   close parenthesis is inserted. */#if defined (HAVE_SELECT)int rl_blink_matching_paren = 1;#else /* !HAVE_SELECT */int rl_blink_matching_paren = 0;#endif /* !HAVE_SELECT */static int _paren_blink_usec = 500000;/* Change emacs_standard_keymap to have bindings for paren matching when   ON_OR_OFF is 1, change them back to self_insert when ON_OR_OFF == 0. */void_rl_enable_paren_matching (on_or_off)     int on_or_off;{  if (on_or_off)    {	/* ([{ */      rl_bind_key_in_map (')', rl_insert_close, emacs_standard_keymap);      rl_bind_key_in_map (']', rl_insert_close, emacs_standard_keymap);      rl_bind_key_in_map ('}', rl_insert_close, emacs_standard_keymap);    }  else    {	/* ([{ */      rl_bind_key_in_map (')', rl_insert, emacs_standard_keymap);      rl_bind_key_in_map (']', rl_insert, emacs_standard_keymap);      rl_bind_key_in_map ('}', rl_insert, emacs_standard_keymap);    }}intrl_set_paren_blink_timeout (u)     int u;{  int o;  o = _paren_blink_usec;  if (u > 0)    _paren_blink_usec = u;  return (o);}intrl_insert_close (count, invoking_key)     int count, invoking_key;{  if (rl_explicit_arg || !rl_blink_matching_paren)    _rl_insert_char (count, invoking_key);  else    {#if defined (HAVE_SELECT)      int orig_point, match_point, ready;      struct timeval timer;      fd_set readfds;      _rl_insert_char (1, invoking_key);      (*rl_redisplay_function) ();      match_point =	find_matching_open (rl_line_buffer, rl_point - 2, invoking_key);      /* Emacs might message or ring the bell here, but I don't. */      if (match_point < 0)	return -1;      FD_ZERO (&readfds);      FD_SET (fileno (rl_instream), &readfds);      timer.tv_sec = 0;      timer.tv_usec = _paren_blink_usec;      orig_point = rl_point;      rl_point = match_point;      (*rl_redisplay_function) ();      ready = select (1, &readfds, (fd_set *)NULL, (fd_set *)NULL, &timer);      rl_point = orig_point;#else /* !HAVE_SELECT */      _rl_insert_char (count, invoking_key);#endif /* !HAVE_SELECT */    }  return 0;}static intfind_matching_open (string, from, closer)     char *string;     int from, closer;{  register int i;  int opener, level, delimiter;  switch (closer)    {    case ']': opener = '['; break;    case '}': opener = '{'; break;    case ')': opener = '('; break;    default:      return (-1);    }  level = 1;			/* The closer passed in counts as 1. */  delimiter = 0;		/* Delimited state unknown. */  for (i = from; i > -1; i--)    {      if (delimiter && (string[i] == delimiter))	delimiter = 0;      else if (rl_basic_quote_characters && strchr (rl_basic_quote_characters, string[i]))	delimiter = string[i];      else if (!delimiter && (string[i] == closer))	level++;      else if (!delimiter && (string[i] == opener))	level--;      if (!level)	break;    }  return (i);}