Re: Extend Record in Spec and Body

["Richard Charts" <richard.charts@gmail.com>]

Jean-Pierre Rosen wrote:
> richard.charts@gmail.com a écrit :
> > Is it possible to extend a record twice in a package?
> > I'm building a component now that will be mostly reusable.  There are a
> > couple packages that are the same, but for one piece the differences
> > require different code.  However, with the way it is designed, it seems
> > I could make the package specs the same and only alter the bodies.
> > I would like to try to hide part of the extended record from the
> > specification without having to change  the operation declarations.
> >
> > I included a small slice of what I'm trying to do.  Is this even
> > possible?
> > Thanks.
> >
> > SPEC:
> >
> > private
> >     type Object is new HigherPackage.object
> >     with record
> >         Repo_View   : Repo_View_Array;
> >     end record;
> >
> > end spec;
> >
> > body
> >     type Object is new HigherPackage.object  -- This is where I'm not
> > sure how to proceed
> >     with record
> >         Data: Data_Array;
> >         Ack: boolean;
> >     end record;
> >
> This is not allowed as stated, but you could derive an Internal_Object
> from Object in the body, and add conversions where needed.
>
> --
> ---------------------------------------------------------
>             J-P. Rosen (rosen@adalog.fr)
> Visit Adalog's web site at http://www.adalog.fr


As a kind of similar question, is it legal to extend an object and have
the new object be variant?

type Object (Type: New_Type is new HigherPackage.object
    with record
        Repo_View   : Repo_View_Array;
        case Type is
            Something =>
                 Test : Natural;
end record;