Re: [Haskell-cafe] Would it be evil to add "deriving Typeable" to newtype Q?

6 May 2010


      On Thu, May 6, 2010 at 4:05 AM, Ivan Miljenovic
 wrote:
...
Re-CC'ing -cafe:
On 6 May 2010 12:54, Leonel Fonseca  wrote:
...
I wasn't aware of GeneralizedNewtypeDeriving.
 I just edited the source file Language.Haskell.TH.Syntax
and left:
newtype Q a = Q { unQ :: forall m. Quasi m => m a }
   deriving Typeable
Hang on, is Q something actually in the template-haskell library?  In
that case, you can't just do "deriving (Typeable)" .
{-# LANGUAGE DeriveDataTypeable, StandaloneDeriving #-}

import Data.Typeable
import Language.Haskell.TH

deriving instance Typeable1 Q

-- Sorted :)

Re: [Haskell-cafe] Would it be evil to add "deriving Typeable" to newtype Q?

Ben Millwood