Hello Mads, Monday, May 4, 2009, 7:01:16 PM, you wrote:
i know two problems in Haskell/GHC that require OO-loke features - extensible exceptions and GUI widget types hierarchy
Yes, type hierarchies require OO.
But, do we really need to represent different widget-types in a hierarchy?
An alternative to a big hierarchy would be to let different widget-types implement different type classes. We could have type classes like MouseEvents, KeyboardEvents, Activated, ...
there is obvious difference between OOP and type class hierarchies - OOP ones includes data fields. (somewhat close functionality provided by extensible records, but they are not in GHC nor provide strong type-checking) this means a lot of boilerplate code written, i.e. we lose compared to OOP -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com