|Portability||non-portable (uses ghc extensions)|
MonadBi represents the relationship between monads that can be transformed into each other (atleast partially).
MonadBi acts as a superset of MonadTrans, and provides
raise analogous to
lift, which lifts underlying monads
into the transformer. It also provides
lower which is the opposite of
lift, and extracts underlying monads
from monad transformers.
Natural instances are provided for many Monad Transformers.