protocols, inheritance and polymorphism

[Donn Cave]

In article <s4qdnUDCJoJ9vjncRVn-hA at rogers.com>,
 "Dan Perl" <danperl at rogers.com> wrote
...
> It's hard to argue against Smalltalk.  I haven't used it for many years so I 
> don't remember it but it was THE language of choice for an OOP course I took 
> oh so many years ago.  And I still see it mentioned as a model for OOP.  I 
> never learned Objective C so I cannot argue with that either. 
> Unfortunately, as much as I am learning to like Python, I don't think I see 
> it as a picture perfect OOP language.  It may be a controversial opinion but 
> I am not at all satisfied with encapsulation in Python (you cannot hide any 
> of a class's implementation).

> Can you elaborate on problems that static languages have with OOP?  We have 
> been touching on parametric polymorphism and that is a valid point.  I also 
> see multiple inheritance as being very poorly implemented in C++ and Java to 
> the point where books on C++ that treat the subject discourage you from 
> using it and Java has effectively designed it out of the language (you can 
> implement many interfaces but you can extend only one class).  What do you 
> have in mind?

I am really too unschooled in these matters to pursue that.
I have mentioned Haskell a couple of times, and that's my
perspective on static typing.  I recommend it as an interesting
exercise:  learn Haskell, find out what static typing is about.
It isn't perfect, but it's leagues ahead of C++ etc.

I don't have any beef with multiple inheritance, in fact the
notion of "mix-in" classes might have some potential to be the
basis for a more sound approach to OO.

   Donn Cave, donn at u.washington.edu