[Haskell-cafe] GeneralizedNewtypeDeriving and TypeFamilies
mxcantor at gmail.com
Mon Jun 14 03:08:20 EDT 2010
So I understand from http://hackage.haskell.org/trac/ghc/ticket/4083 that GeneralizedNewtypeDeriving doesn't play well with TypeFamilies.
But, if a typeclass is only using type synonyms, is there any reason why newtype deriving would not work? For a toy example:
class Cls a where
type MyType a
foo :: MyType a ->
in this case, if you have something like:
instance Cls () where
type MyType () = ()
foo = id
newtype Bar = Bar () deriving (Cls)
be well defined?
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