Re: [Yap-users] Java - Yap Communication

[Oliver W. <Ath...@gm...>]

Hi, 
> 
> > I'm trying to connect a Java Program to my Yap Code (Version 4.3.20).
> > I start the Java through Yap with the "exec(Command,IO-List,Status)"
> > Command.
> > 
> 
> I have been using that command myself and it seems to be working.
The Command is working fine, that is right.
> 
> > I have Problems to build up a communication between those Parts, and
> tried
> > to do it 
> > using the IO-List Parameters in exec/3 . I failed so far.
> > 
> > Yap-Side:
> > 
> > :- exec('java Frame',[user_input,user_output,user_error],Status).
> > 
> > :- write(MSG_O).
> > 
> > :- read(MSG_I).
> > 
> > Java-Side:
> > 
> > BufferedReader in = new BufferedReader(new
> InputStreamReader(System.in));
> > String tempString = "";
> > 
> > while (tempString.compareTo("eof")!= 0)  {
> >         tempString = in.readLine();
> >         log.println(tempString);   // writes received MSG into a
> Log-File
> >         System.out.println("pos.");
> > }
> > 
> 
> I don't understand very well what you are trying to do. You seem to be
> wanting to share the standard descriptors, and I don't know if you can
> use them to communicate. 

It looks like I can not use the standard descriptors to communicate, so I'm
glad for 
your advice.
> 
> In my program what I do to communicate with a matlab process is:
> 
>  exec('matlab -nojvm
-nosplash',[pipe(CommandStream),pipe(Answer),pipe(Answer)],_),
> 
> I send commands to the matlab shell using this procedure:
> 
> send_command(OStream, IStream, String, Args) :-
>  format(OStream, String, Args),
>  wait_for_matlab_prompt(IStream).
> 
> wait_for_matlab_prompt/1 just scans matlab until finding a matlab
> prompt, which will be of the form >> or EDU>:
> 
> wait_for_matlab_prompt(Answer) :-
>  fetch_prompt(Answer, -1). 
> 
> fetch_prompt(Answer, C0) :-
>  get0(Answer, C1),
>  ( ((C0 = 0'> ; C0 = 0'U ) ,C1 = 0'> ) ->
>      true
>  ;
>      fetch_prompt(Answer, C1)
>  ).
> 
> It works fine for me (well, matlab is very slow ;-).
> 
> > Any Help or new Suggestions are Welcome.
> > Thanks in advance for your Time and Help.
> > 
> 
> Does this help?

Thanks, it does answers some of the Questions I had,
I tried it already, and I do not understand how to send to the created Pipe.
I tried it with write/2 but I have no Idea how to handle the IO-Stream, 
I tried so far ...
:- exec('java Frame',[pipe(Stream),pipe(Answer),null],_).
:- write(Stream, "message").
[ INSTANTIATION ERROR- write/2 in prolog:write/2: expected bound value ] 
or
:- exec('java Frame',[pipe(Stream),pipe(Answer),null],_).
:- write(pipe(Stream), "message").
[ DOMAIN ERROR- write/2 in prolog:write/2: pipe(_537) not a stream ]
or
:- exec('java Frame',[pipe(stream),pipe(answer),null],_).
:- write(stream, "message").
:- user:exec(java Frame,[pipe(stream),pipe(answer),null],_552) failed.
[ EXISTENCE ERROR- write/2 in prolog:write/2: stream not an open stream ]
or
:- exec('java Frame',[pipe(stream),pipe(nswer),null],_).
:- write(pipe(stream), "message").
:- user:exec(java StoryFrame,[pipe(stream),pipe(answer),null],_552) failed.
[ DOMAIN ERROR- write/2 in prolog:write/2: pipe(_537) not a stream ]
It did not work ... the docs did not help.

Thanks so far
Oliver 

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