Re: friend classes in ada95

["Stanley R. Allen" <Stanley_R_Allen-NR@raytheon.com>]

David Botton wrote:
> 
> Of course, I can already do interface MI in Ada already, so this is really
> just about syntax. I am not happy that Ada comes out looking bad in OO
> circles, since most people can not bridge the gap from "class  X" to "type X
> is tagged", even though there is none.
> 

If they can't bridge this gap, it may be because prejudice is in
the way.

If that's not the problem, then the barrier may be that they are
attempting to make a direct leap from the C++ (or Java) model to
Ada 95.  It's a common mistake C++ people make when learning Java,
and we've seen more than a few questions here on c.l.a reflecting
that kind of confusion.

I like the approach N. Cohen uses in the second edition of "Ada
as a Second Language" to present the topic -- building up a
complete picture of the Ada model based on a discussion of derived
types, leaving comparisons to other languages until the end.

-- 
Stanley Allen
mailto:Stanley_R_Allen-NR@raytheon.com

P.S.

I'm still waiting for a good, thorough book focused on advanced OO
programming in Ada 95.  The general Ada textbooks are mostly for
beginners.  The discussions in the Rationale are a good starting
point, but obviously every aspect of the topic could not be discussed
in the space provided there.  Matthew Heaney's patterns articles contain
many of the things one would like to see in an "OO techniques for Ada 95"
book.