02.10.2011 19:55, David Barbour пишет:
Use TypeFamilies.{-# LANGUAGE TypeFamilies #} ... type family FType a :: * type instance FType Char = Float type instance FType Double = Int class ExampleClass a where f :: a -> FType a
Better to include type in class. class ExampleClass a where type FType a f :: a -> FType a instance ExampleClass Char where type FType Char = Float f char = ... _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
