Re: "Classes" as packages in Ada

[Brian Rogoff <bpr@shell5.ba.best.com>]

On 25 Nov 1998, Robert I. Eachus wrote:
> In article <3UU62.124$8X3.638914@news.rdc1.az.home.com> "John Goodsen" <jgoodsen@radsoft.com> writes:
> 
>   > So my conclusion is that Ada code for an interface is not even
>   > close in simplicity (from the programmer's point of view) as
>   > something like...
> 
>    About all I can say, is you are right, and you are wrong.  As Ed
> pointed out, most of what requires interfaces in other languages is
> done with generic mix-ins in Ada 95.  I'd say you were comparing
> apples and oranges, but it is more like comparing Waldorf salad and
> apples. 

Well, I think in this case that John is more right than wrong, though I'd
add a great big "So !@#$ing what?" to that since any number of things
involving generics, enums, range types, etc., etc. are expressed simply in
Ada and with a bit more difficulty in Java. 

OTOH, the interface feature of Java, or the "signature" feature of 
GNU C++, are IMO appealing candidates for consideration in a future
version of Ada. Interfaces, besides capturing the most common use of 
multiple inheritance, make Norman Cohen's workaround to the "withing
problem" (the dummy parent approach) much more acceptable IMO.

-- Brian