Re: MI in Ada 200X

[Stephen Leake <Stephe.Leake@nasa.gov>]

Hyman Rosen <hyrosen@mail.com> writes:

> Here's a particular example which is ever annoying in Java. A
> common design pattern in Java is to have an interface, and then
> make a companion class which implements the interface and provides
> do-nothing implementations for all the methods. If you want a class
> which implements both interfaces and does nothing for most of the
> methods, you can't inherit from both companion classes. Instead,
> you must reimplement at least one set of the dunsel methods.

Interestingly, the Ada interface type proposal AI solves this
particular problem, by allowing interface types to have explicitly
null procedures:

    type T is interface;

    procedure Foo (Item : in T) is null;

:).

-- 
-- Stephe