However, TypeFamilies seems too be non portable as according to this http://www.haskell.org/haskellwiki/GHC/Type_families, it works only as from GHC 6.10.1. Henning Thielemann-4 wrote:
Miguel Mitrofanov schrieb:
-- {-# LANGUAGE FunctionalDependencies#-} -- {-# LANGUAGE MultiParamTypeClasses #-} {-# LANGUAGE TypeFamilies #-} module Register where -- class Register a r | a -> r class Register a where type R a -- instance Register Int Int instance Register Int where type R Int = Int -- instance Register Float Float instance Register Float where type R Float = Float -- instance (Register a1 r1, Register a2 r2) => Register (a1, a2) (r1, r2) instance (Register a, Register b) => Register (a, b) where type R (a, b) = (R a, R b)
So type functions are undecidable by default?
_______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
----- Yves Parès Live long and prosper -- View this message in context: http://old.nabble.com/Undecidable-instances-with-functional-dependencies-tp2... Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com.