Re: Separate Compilation in Programming Languages

[Ray Blaak <rAYblaaK@STRIPCAPStelus.net>]

<adaworks@sbcglobal.net> writes:

> An implementation of an Interface (in Java) is still tightly bound to
> its specification, and any change of that implementation will carry forward.

But of course. And that is exactly analogous a change to an Ada package spec
impacting the package body.

> It is true that the Interface specification remains unchanged, and that is a
> good thing.  However, if any part of the Interface specification changes,
> every other unit dependent on that specification will also have to be
> recompiled.  

Again, exactly the same as changing an Ada package spec.

> In the Ada model, where I defer the dependency on that
> Interface to the body of the dependent package, I need not recompile the
> specification of the dependent package.  Rather, I can compile only the
> body, leaving the rest of my architecture intact.

Recompiling a file does not imply the need to imply client files if the
public signatures have not changed. Most IDEs can handle this.

Also, recompiling an implementation class will not cause a recompilation of
the interface clients at all, since they do not even (necessarily) see the
implemetation in the first place.

Again, exactly analogous to an Ada package body needing to be
recompiled. Ada's separation of spec and body is what allows you to do this. A
Java interface and its implementation class is an analogous separation.

> I'm not sure why this is such a difficult idea.  It is probably because I am
> not expressing it with sufficient skill.

Well, as politely as possible, I submit that it is not about the skill, but
that I think you are mistaken.

-- 
Cheers,                                        The Rhythm is around me,
                                               The Rhythm has control.
Ray Blaak                                      The Rhythm is inside me,
rAYblaaK@STRIPCAPStelus.net                    The Rhythm has my soul.