16 Dec
2012
16 Dec
'12
3:22 p.m.
On Sun, Dec 16, 2012 at 06:30:45PM +0000, Henning Thielemann wrote:
What about this instance:
module Data.Functor.Compose
import Control.Monad.Trans.Class (MonadTrans, lift)
instance (Monad f) => MonadTrans (Compose f) where lift x = Compose (return x)
?
MonadTrans suggests that the constructed thing is a monad (though I see the documentation doesn't quite say that).