[Haskell-cafe] Restrictions on associated types for classes
Tom Schrijvers
Tom.Schrijvers at cs.kuleuven.be
Thu Dec 17 09:22:23 EST 2009
> class MyClass k where
> type AssociatedType k :: *
>
> Is there a way of requiring AssociatedType be of class Eq, say?
Have you tried:
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE FlexibleContexts #-}
class Eq (AssociatedType k) => MyClass k where
type AssociatedType k :: *
?
Cheers,
Tom
--
Tom Schrijvers
Department of Computer Science
K.U. Leuven
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e-mail: tom.schrijvers at cs.kuleuven.be
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