Re: Separate Compilation in Programming Languages

[<adaworks@sbcglobal.net>]

"Alex R. Mosteo" <amosteo@unizar.es> wrote in message 
news:62ic8uF230f4oU1@mid.individual.net...
>
> I'd go farther and say that proper OO programming practice stresses the
> fact that  clients must operate on interfaces, and not on particular
> implementation classes. Yes, it takes discipline, but it is what is
> expected. (Or what I would expect?)
>
The reality is that this practice is rare.  Interfaces are not as abundant
in Java programs as you might wish.

> Still, having used both Java and Ada, I find true that Ada, by forcing
> always the separation, helps in "indoctrinating" this into programmers.
> Specifications in Ada are a blessing.

Yes.  Prior to the conversation in this thread, I was not as sure of that
as I am now.   It has become clear to me that the Ada model, based
on the notion of compilation units, continues to be much better than
the Java model where, in practice, dependency management on
large-scale software systems can range from simply annoying to
absolutely wrong.

The argument from C++ programmers use to be, "We don't have
such problems if we are careful ..."   "... if we are good programmers ..."
"... if we follow good practices ..."

But the fact is that a language design needs to prevent "bad practices"
and Ada tends to do that.   When hundreds of messages appear on
the Internet complaining about Java's dependency problems, this is
an indication that the issue is not about programming practice, but about
a deficiency in the design of the language.

Richard Riehle