On 13/02/12 18:16, Edward Kmett wrote:

You could probably get away with something like

data Proxy = Proxy a

class Typeable a where
typeOfProxy :: Proxy a -> TypeRep

typeOf :: forall a. Typeable a => a -> TypeRep
typeOf = typeOfProxy (Proxy :: Proxy a)

which being outside of the class won't contribute to the inference of
'a's kind.

This would let you retain the existing functionality.

Simon's version has this:

typeOf :: forall a. Typeable a => a -> TypeRep
typeOf x = typeRep (getType x) where
getType :: a -> Proxy a
getType _ = Proxy

(your version is clearer, though)

I'm assuming there's no significance behind your renaming of 'typeRep' to 'typeOfProxy'?

No significance at all. I probably should have read the page before commenting. ;)

-Edward