AbstractOutputSream

:-dynamic(wotp_server_port/1).
wotp_server_port(16996).

wotp_lambda([Data],Call,Data):-Call.

% Redirect output stream and read_line_to_string to write to a predicate
with_output_to_pred(Pred, Call):-
   with_output_to_pred(read_line_to_string, Pred, Call).

% Redirect output stream to write to a predicate with ReaderPred line [read_line_to_string,get_char,..]
with_output_to_pred(ReaderPred, Pred, Call):- thread_self(ID),
   wotp_client(ReaderPred, wotp_lambda([Data],thread_signal(ID,call(Pred,Data))),Call).

wotp_client(ReaderPred,Pred, Call):-
    wotp_create_server,
    must(wotp_server_port(Port)),
    tcp_socket(Socket),
    tcp_connect(Socket, localhost:Port),
    tcp_open_socket(Socket, StreamPair),
    stream_pair(StreamPair, In, Out),
    wotp_io_setup(In, Out),
    format(Out,'~N~q.~nq.~n',[ReaderPred,Pred]),
    flush_output(Out),
    setup_call_cleanup(tell(Out),Call,
     ignore(((format(Out,'~N',[]),told,ignore(catch(close(StreamPair, [force(true)]),_,true)))))).


wotp_create_server(Port):- thread_property(_T,alias(wotp_server)),!.
wotp_create_server(Port):-
        (wotp_server_port(Port) -> true ; asserta(wotp_server_port(Port))),
        tcp_socket(ServerSocket),
    tcp_setopt(ServerSocket, reuseaddr),
    tcp_bind(ServerSocket, Port),
    tcp_listen(ServerSocket, 5),
    thread_create(wotp_server_loop(ServerSocket), _,[ alias(wotp_server)]).

wotp_server_loop(ServerSocket) :-
    tcp_accept(ServerSocket, Client, _Peer),
    tcp_open_socket(Client, StreamPair),
        gensym(wotp_client_,Alias),
    thread_create(wotp_service(Client, StreamPair),_,[alias(Alias),detached(true)]),
    wotp_server_loop(ServerSocket).

wotp_service(Client, StreamPair):-
         stream_pair(StreamPair, In, Out),
         wotp_io_setup(In, Out),
         read(In,ReaderPred),read(In,Pred), debug(wotp,'~q. => ~q. ~n',[ReaderPred,Pred]),
         repeat,
         call(In,Data), debug(wotp,'~q.~n',[call(In,Data)]),
         ((Data \==end_of_file, Data \== -1 ) -> (once(call(Pred,Data)),fail) ;
         ignore(catch(close(StreamPair, [force(true)]),_,true))).


wotp_io_setup(In, Out):-
      set_stream(In, close_on_abort(false)),
      set_stream(Out, close_on_abort(false)),
      current_prolog_flag(encoding, Enc),
      set_stream(In, encoding(Enc)),
      set_stream(Out, encoding(Enc)),
      set_stream(In, newline(detect)),
      set_stream(Out, newline(dos)).

wotp_create_server:- (wotp_server_port(Port)->wotp_create_server(Port);wotp_create_server(16996)).

:- source_location(S,_),forall(source_file(H,S),ignore((  \+ (predicate_property(H,PP),member(PP,[(multifile),built_in])),
 functor(H,F,A),module_transparent(F/A),export(F/A)))).

:- wotp_create_server.

% Example
:- with_output_to_pred(say(dmiles), format('Hello World~n',[])).