-fno-monomorphism-restriction

[Christian Maeder]

Christian Maeder wrote:
> I've found a much shorter example (without imports) that does not 
> compile. 

and shorter:

{-# OPTIONS -fno-monomorphism-restriction #-}
module NoMonoRestr where

data ATermTable = ATermTable

data Annotation = Annotation

data Annoted a = Annoted a [Annotation]

toPair ::
     ATermConvertibleSML a => ATermTable -> (a,[Annotation])
toPair = undefined

class ATermConvertibleSML t where
     from_sml_ShATerm     :: ATermTable -> t

instance (ATermConvertibleSML a) => ATermConvertibleSML (Annoted a) where
     from_sml_ShATerm att =
         let (bi,las) = toPair att
         in Annoted bi las