Hello Eric, Saturday, April 28, 2007, 5:33:02 PM, you wrote:
Type classes allow us to adopt approach (0) in Haskell, but don't seem to allow approach (1)....
may be multi-parameter type class is what you need here, may be just closure. anyway, OOP may be simulated in Haskell via hierarchy of existentials but such emulation is too expensive (in terms of easiness of programming) i highly recommend you to read http://haskell.org/haskellwiki/OOP_vs_type_classes and papers mentioned at the end there in order to grok relations between FP, OOP, type classes and existentials. unfortunately, dynamics are not yet mentioned there, read 'An Extensible Dynamically-Typed Hierarchy of Exceptions' by Simon Marlow -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com