Accessing Parametric object from category

Question

how to Access Parametric object from a ategory

:- category(attributes).

    :- public(info/1).
    info(Value) :- arg(1,_Array_,Value).

:- end_category.

:- object(array(_Array_),imports([attributes])).

this does not work ...

 *     Singleton variable: _Array_

Answer 1

As entity parameters are logical variables, simply share them between the object and the category:

:- category(attributes(_Array_)).

    :- public(info/1).
    info(Value) :-
        arg(1, _Array_, Value).

:- end_category.


:- object(array(_Array_),
    imports(attributes(_Array_))).

:- end_object.