Re: TTY debugger and the portray mechanism.

Dear Josh,

>You add arguments to the implementing structure, but forget to update the
>arity in the :- export(portray ... line. It would be nice if at compile time
>this line could look up the arity of the struct just given the functor.  

You can actually do this (for a couple of releases now, I think), as
described in the bip doc for (struct)/1:

    The arity of the structure can be obtained using a term of the
    following form

        property(arity) of StructName

    instead of having to explicitly give the arity of the structure.

For example we use it in eplex:

:- export struct(
	prob(
          .....
        )).

:- local portray(prob/(property(arity) of prob), lp_handle_tr_out/2, []).


Cheers,

Kish