[Haskell-cafe] Object Oriented programming for Functional Programmers

[Gershom Bazerman]

On 1/2/13 4:29 PM, MigMit wrote:
>
>> BTW. Why you think that Eiffel type system is unsafe?
> Well, if I remember correctly, if you call some method of a certain object, and this call compiles, you can't be certain that this object actually has this method. Could be that this object belongs to some subclass which removes this method.
>

Eiffel doesn't handle the relationship of co- and contra-variance of 
arguments with subtyping in a principled way. This is apparently known 
as the "catcall" problem. See, e.g., this article: 
http://www.eiffelroom.org/node/517

--Gershom