On 8 Jan 2009, at 23:59, Henning Thielemann wrote:
GHC accepts a class declaration like class Monad (m Maybe) => C m where ... without having any language extension switched on. But it isn't Haskell 98, is it?
It is. From Report: ======================== A class assertion has form qtycls tyvar, and indicates the membership of the type tyvar in the class qtycls. A class identifier begins with an uppercase letter. A context consists of zero or more class assertions, and has the general form ( C1 u1, ..., Cn un ) where C1, ..., Cn are class identifiers, and each of the u1, ..., un is either a type variable, or the application of type variable to one or more types. ======================== "atype" is defined as ======================== atype -> gtycon | tyvar | ( type1 , ... , typek ) (tuple type, k>=2) | [ type ] (list type) | ( type ) (parenthesised constructor) ========================
Hugs 2005 also accepts this. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe