Re: Another important feature of Ada

[Ed Falis <efalis@mediaone.net>]

Jean-Pierre Rosen wrote:

> The importance of separating specs from bodies is *not* the ability to
> view them separatly, which can be accomplished with a tool as
> you note. It is the ability to compile the spec, and compile users of
> the spec before even thinking about the implementation.
> Therefore you can check the spec, and check that the spec matches the
> needs without being influenced by implementation constraints
> (which often leads to over-specification).

Yes, I should have mentioned that this is easily (and often) done in
Eiffel using completely deferred classes with assertions.  A deferred
class is similar to an abstract tagged type in a package.

I agree with your point about the value of being able to compile against
unimplemented specs - it's always been one of my favorite aspects of
Ada.  But the same effect can be achieved otherwise.

- Ed