Re: Ada 2005?

[jayessay <nospam@foo.com>]

Georg Bauhaus <sb463ba@l1-hrz.uni-duisburg.de> writes:

> Dmitry A. Kazakov <mailbox@dmitry-kazakov.de> wrote:
> : Nope, in Ada it is the equivalent of "method is final and defined to raise
> : Constraint_Error". It is a fundamentally different case.
> 
> What is the fundament, then?

The cases I am talking about are situations where constraint error is
raised in exactly the situations that "method not found" is raised in
something like Smalltalk.  They can arise from legal view conversions
to effect runtime dispatching.


> :>>> Ah, so you define it away.
> 
> Or invent a new one?

I think you have the correct interpretation.  DAK seems to want to
simply redefine what MD means.  You can do that, but don't expect
people familiar with the definition in wide use for years to pay it
much attention.

> What did the makers of GNAT think when they invented the error message,
> 
>  "operation can be dispatching in only one type"?

I see you do understand this.  Yes, the GNAT folks are giving the
exact correct error here and it is saying that you cannot dispatch
across multiple types nor that a dispatching operation will
automatically redispath to the secondary operation from the primary.


> So at the very least there must exists a notion of MD that isn't
> available with Ada.

Exactly.


/Jon

-- 
'j' - a n t h o n y at romeo/charley/november com