Hello list. Since NHC doesn't distribute Control.Monad.Error that, among other things, defines the Monad (Either e) instance, I wrote the following module for Cabal: http://cvs.haskell.org/darcs/cabal/Compat/H98.hs However, when I compile it, the Monad instance seems to disappear! With a small test program
module Main where import Monad import Compat.H98 foo :: Either Char [()] foo = sequence [Right (), Left 'a', Right (), Left 'b'] main = print foo
nhc complains: Fail: The class Prelude.Monad has no instance for the type Prelude.Either. and indeed if I look at Compat/H98.hi, it mentions instance Error Prelude.Char; instance (Error a) => Error [a]; but nothing about Error e => Monad (Either e) What should I do? Is this a bug? /Martin