Re: [Haskell-cafe] Automatic derivation (TemplateHaskell?)

Joel Reymont wrote:

This is in Language.Haskell.TH.Syntax which is imported at the top of Data/Derive/TH.hs so I don't understand the cause of the error

instance Functor Q where fmap f (Q x) = Q (fmap f x)

...

Any suggestions?

Since Q is a Monad, you can make the instance

instance Functor Q where fmap = liftM

But Q is exported by Languave.Haskell.TH.Syntax !!!

Only the type constructor is exported, not the data constructor. Twan