Hello Wolfgang, Tuesday, May 5, 2009, 8:27:17 PM, you wrote:
i know two problems in Haskell/GHC that require OO-loke features - extensible exceptions and GUI widget types hierarchy
Note that you don’t need different types for different kinds of GUI widgets if you use Functional Reactive Programming (FRP). You need different types if you use OO because you have to explicitely modify widgets after you have created them, and what modifications you are allowed to do, depends on the kind of widget. With FRP, you specify the behavior over all time when you create the widget, so no need for later method calls.
(i don't know anything about FRP) i think it doesn't change anything. the main reason why i need common operations is because i write generic procedures. another erason os what i can't remember 100 individual 'setSize' operations for 100 types of widgets. so we need to have some generic names, short of they are used due initialization or later -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com