Does it make sense to remove slots ?

[Massimo Dentico]

David Hopwood wrote:
 
> Exactly: you don't need a Circle type at all, so there is no problem
> to solve. This applies to a large proportion of cases of supposed
> problems involving Liskov substitutability.

Unacceptable: the example of ellipses and circles is perfectly
valid as representative of situations in the real world.

 
> But see <http://c2.com/cgi/wiki?DarwenAndDatesTypeSystem>.

This page is void, so...


> Essentially, Darwen and Date "solve" the subtyping problem by
> prohibiting objects from having identity or modelling mutable
> state. This is only practical if you have a language that fully
> supports a pure object-functional programming style; otherwise
> the cure is worse than the disease.

.. this is an unsubstantieted claim. Please, explain: their
model is NOT purely functional by any means, they have
updatable variables, as in all *imperative* programming
languages.

Well, we are OT on the Slate mailing list. Suggestions
are welcome for a more appropriate place to carry on
this discussion.


Regards.

--
Massimo Dentico