Sorry, that was a stupid error. I meant to use fromEnum:

next:: (Enum a, Bounded a) => a -> a next v = if (fromEnum v) == (fromEnum maxBound) then minBound else succ v

I don't think this will quite work if fromEnum:: a -> Int for type a, were not injective. However, that might be part of the specification... I don't remember. It should be fine, so long as the preimage of (fromEnum maxBound) is {maxBound}. -Arjun -- Arjun Guha