Is Ada an OO Language? (was => Re: polymophism)

[Richard Riehle <rriehle@nunic.nu.edu>]

On Fri, 22 Nov 1996, Norman H. Cohen wrote:

in response to 

> James O'Connor wrote:
> 
> > I once posted here, a long time ago, that I don't think Ada95 was an OO language.
> > I received polite and informed rebuttals. I'll say it again, for the same reasons, and
> > expect the same response so now hard feelings to anyone around.

  [ snipped a long and thoughtful dialogue ]

  Dr. Cohen concludes with this excellent  observation:

> Fine.  As long as we are agreed that Ada makes it easy to implement an
> OO design in an OO manner, who cares what labels you attach to the
> language?  (Personally, I think that a good definition of an OO language
> is one that makes it easy to implement an OO design in an OO manner, and
> that any other definition is misleading, but I certainly recognize your
> right to define things misleadingly if it pleases you.)

  I have been wondering recently (only to discover I am not alone in so
  wondering) whether our current devotion to the notion of object is not
  leading us down a blind alley.  Certainly, the fundamental idea of
  "object" has been useful, but it may also seduce us into excessive
  dependence on a concept that is, by its nature, self-limiting. Moreover,
  though the mechanisms and structures we associate with objects may
  be useful, perhaps they too are self limiting.  For example, as we  
  debate to virtue of single-inheritance versus multiple-inheritance
  (only one example) we can often miss the point of what we are actually
  doing with software .  

  This is not to suggest returning to the old days before we thought
  about software in terms of objects.  It simply is a question about
  the potential limitations inherent in our commonly accepted view
  of software objects. Perhaps the notion of object is too small an
  idea.  

  Richard Riehle