/* File:      flrio.flr
**
** Author(s): Michael Kifer
** Contact:   flora-users@lists.sourceforge.net
**
** Copyright (C) The Research Foundation of SUNY, 2001
** 
** FLORA-2 is free software; you can redistribute it and/or modify it under the
** terms of the GNU Library General Public License as published by the Free
** Software Foundation; either version 2 of the License, or (at your option)
** any later version.
** 
** FLORA-2 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 Library General Public License for
** more details.
** 
** You should have received a copy of the GNU Library General Public License
** along with FLORA-2; if not, write to the Free Software Foundation,
** Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
**
** $Id: flrio.flr,v 1.12 2003/06/18 07:01:27 kifer Exp $
**
*/

#include "standard.h"
#include "flora_terms.flh"

%% The purpose of this library is to provide optimal conversion from
%% HiLog to Prolog and back before passing the arguments to the I/O predicates.
%% In addition, it passes the result through flora_write_oid/1 in order 
%% to ensure that all the FLORA module info and encoding is stripped.
%%
%% This all is ued for user-level output. For file I/O one should use
%% @prolog() instead of @flora(io), i.e., use Prolog I/O primitives directly.

%%%%%%%%%%%%%%%%%%%%%%
%% I/O port based ops
%%%%%%%%%%%%%%%%%%%%%%

Filename[#open(Mode,Port)] :- file_open(Filename,Mode,Port)@prolog(file_io).
Port[#close] :- file_close(Port)@prolog(file_io).

Port[#read(HResult)] :-
	integer(Port),
	!,
	file_read(Port, PResult)@prolog(file_io), p2h{PResult,HResult}.
Port[#write(Term)] :-
	integer(Port),
	!,
	flora_write(Port,Term)@prolog(flrdisplay).
stdread(HResult) :-
	file_read(STDIN, PResult)@prolog(file_io), p2h{PResult,HResult}.
stdwrite(Term) :-
	flora_write(STDOUT,Term)@prolog(flrdisplay).


%% Use arg(obj, obj, obj) to supply multiple arguments
fmt_write(Format,O) :-
	!,
	florify_arguments(O,FO),
	fmt_write(Format,FO)@prolog().
FileHandle[#fmt_write(Format,O)] :-
	florify_arguments(O,FO),
	fmt_write(FileHandle,Format,FO)@prolog().
fmt_write_string(String,Format,O) :-
	!,
	florify_arguments(O,FO),
	fmt_write_string(String,Format,FO)@prolog().
fmt_read(Format,Result,Status) :-
	!,
	fmt_read(Format,PResult,Status)@prolog(),
	p2h{PResult,Result}.
FileHandle[#fmt_read(Format,Result,Status)] :-
	fmt_read(FileHandle,Format,PResult,Status)@prolog(),
	p2h{PResult,Result}.

Filehandle[#write_canonical(HTerm)] :-
	p2h{PTerm,HTerm},
	file_write_canonical(Filehandle,PTerm)@prolog(xsb_writ).
write_canonical(HTerm) :-
	p2h{PTerm,HTerm}, write_canonical(PTerm)@prolog().

read_canonical(HTerm) :-
	read_canonical(PTerm)@prolog(), p2h{PTerm,HTerm}. 
Filehandle[#read_canonical(HTerm)] :-
	file_read_canonical(Filehandle,PTerm,_)@prolog(machine),
	p2h{PTerm,HTerm}. 
Filehandle[#readline(atom,String)] :-
	!, file_read_line_atom(Filehandle,String)@prolog(file_io).
Filehandle[#readline(charlist,String)] :-
	!, file_read_line_list(Filehandle,String)@prolog(file_io).
_Filehandle[#readline(Request,_)] :- 
	abort(('Invalid readline format, ', Request))@flora(sys).
readline(atom,String) :-
	!, file_read_line_atom(String)@prolog(file_io).
readline(charlist,String) :-
	!, file_read_line_list(String)@prolog(file_io).
readline(Request,_) :- 
	abort(('Invalid readline format, ', Request))@flora(sys).


%%%%%%%%%%%%%%%%%%%%
%% Stream-based I/O
%%%%%%%%%%%%%%%%%%%%

write(O) :- !,
	flora_write_oid(O)@prolog(flrdecode).
IOstream[#write(O)] :-
	flora_write_oid(IOstream,O)@prolog(flrdecode).
writeln(O) :- !,
	flora_write_oid(O)@prolog(flrdecode),
	nl@prolog().
IOstream[#writeln(O)] :-
	flora_write_oid(IOstream,O)@prolog(flrdecode),
	nl(IOstream)@prolog().
nl :- nl@prolog().
nl(IOstream) :- nl(IOstream)@prolog().

read(Result) :- !, read(PResult)@prolog(), p2h{PResult,Result}.
IOstream[#read(Result)] :-
	read(IOstream,PResult)@prolog(), p2h{PResult,Result}.

Filename[#see] :- see(Filename)@prolog().
seen :- seen@prolog().
seeing(Stream) :- seeing(Stream)@prolog().

Filename[#tell] :- tell(Filename)@prolog().
tell(Filename) :- tell(Filename)@prolog().
told :- told@prolog().
telling(Stream) :- telling(Stream)@prolog().



%% UTILITIES

%% This is used for fmt_write_* predicates. Takes a *prolog* term argument 
%% of the form 
%% _(arg1,...,argn) and returns _(arg1',..., argn'), where arg_i=arg_i'
%% if arg_i is not compound. Otherwise we apply flora_write_oid/1
%% This is needed in order make sure that arguments like f(a) are printed 
%% as f(a) and not _flora'main'f(a) or something like that.
florify_arguments(WrappedArgs,OutTerm) :-
	WrappedArgs =.. [WRAP_HILOG, Fun | Args],
	!,
	florify_arglist(Args,OutList),
	OutTerm =.. [Fun|OutList].
%% single argument to fmt_write without the arg(...) envelope
florify_arguments(Arg,OutTerm) :-
	flora_decode_oid_as_atom(Arg,OutTerm)@prolog(flrdecode).
florify_arglist([],[]) :- !.
florify_arglist([Arg|Args], [OutArg| OutArgs]) :-
	compound(Arg)@prolog(),
	!,
	flora_decode_oid_as_atom(Arg,OutArg)@prolog(flrdecode),
	florify_arglist(Args,OutArgs).
florify_arglist([_Arg|Args], [_Arg| OutArgs]) :-
	florify_arglist(Args,OutArgs).