1/*  Part of SWI-Prolog
    2
    3    Author:        Jan Wielemaker
    4    E-mail:        J.Wielemaker@vu.nl
    5    WWW:           http://www.swi-prolog.org
    6    Copyright (c)  2016, VU University Amsterdam
    7    All rights reserved.
    8
    9    Redistribution and use in source and binary forms, with or without
   10    modification, are permitted provided that the following conditions
   11    are met:
   12
   13    1. Redistributions of source code must retain the above copyright
   14       notice, this list of conditions and the following disclaimer.
   15
   16    2. Redistributions in binary form must reproduce the above copyright
   17       notice, this list of conditions and the following disclaimer in
   18       the documentation and/or other materials provided with the
   19       distribution.
   20
   21    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   22    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   23    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   24    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   25    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   26    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   27    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   28    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   29    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   30    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   31    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   32    POSSIBILITY OF SUCH DAMAGE.
   33*/
   34
   35:- module(readline,
   36          [ rl_read_init_file/1,
   37            rl_add_history/1,
   38            rl_write_history/1,
   39            rl_read_history/1
   40          ]).   41
   42readline_ok :-
   43    \+ current_prolog_flag(console_menu_version, qt),
   44    \+ current_prolog_flag(readline, editline),
   45    stream_property(user_input, tty(true)).
   46
   47:- use_foreign_library(foreign(readline4pl)).   48:- if(readline_ok).   49:- initialization rl_wrap.   50:- endif.   51
   52/** <module> GNU readline interface
   53
   54This library binds GNU  libreadline  to   SWI-Prolog.  The  GNU readline
   55library provides emacs and vi based  editing   of  queries on the Prolog
   56toplevel, including TAB-based completion and history.
   57
   58This library is by default  loaded   into  an interactive Prolog process
   59that is connected to a  (Unix)  terminal.   Loading  can  be  stopped by
   60setting the Prolog flag `readline` to `false`.
   61
   62@license Although the  interface  is   BSD-licensed,  the  GNU  readline
   63library itself is covered by  the   GPL  (General  Public License). This
   64implies that loading this  library  in   an  application  makes all code
   65loaded into the application subject to the GPL conditions.
   66*/
   67
   68%!  rl_read_init_file(+File) is det.
   69%
   70%   Read a GNU readline config file.  See   the  GNU readline manual for
   71%   details.
   72
   73%!  rl_add_history(+Line) is det.
   74%
   75%   Add a line to the history.
   76
   77%!  rl_write_history(+File) is det.
   78%
   79%   Save the history to File. This  can   be  reloaded in a next session
   80%   using rl_read_history/1.
   81
   82%!  rl_read_history(+File) is det.
   83%
   84%   Read a saved history from File.
   85
   86
   87:- multifile
   88    prolog:history/2.   89
   90prolog:history(_Input, add(Line)) :-
   91    rl_add_history(Line).
   92prolog:history(_Input, load(File)) :-
   93    rl_read_history(File).
   94prolog:history(_Input, save(File)) :-
   95    rl_write_history(File)