transformers- Concrete functor and monad transformers

Safe HaskellSafe-Inferred




The ListT monad transformer, adding backtracking to a given monad, which must be commutative.


The ListT monad transformer

newtype ListT m a Source

Parameterizable list monad, with an inner monad.

Note: this does not yield a monad unless the argument monad is commutative.


ListT (m [a]) 


MonadTrans ListT 
Monad m => Monad (ListT m) 
Functor m => Functor (ListT m) 
Monad m => MonadPlus (ListT m) 
Applicative m => Applicative (ListT m) 
Foldable f => Foldable (ListT f) 
Traversable f => Traversable (ListT f) 
Applicative m => Alternative (ListT m) 
MonadIO m => MonadIO (ListT m) 
Show1 m => Show1 (ListT m) 
Read1 m => Read1 (ListT m) 
Ord1 m => Ord1 (ListT m) 
Eq1 m => Eq1 (ListT m) 
(Eq1 m, Eq a) => Eq (ListT m a) 
(Ord1 m, Ord a) => Ord (ListT m a) 
(Read1 m, Read a) => Read (ListT m a) 
(Show1 m, Show a) => Show (ListT m a) 

runListT :: ListT m a -> m [a]Source

The inverse of ListT.

mapListT :: (m [a] -> n [b]) -> ListT m a -> ListT n bSource

Map between ListT computations.

Lifting other operations

liftCallCC :: CallCC m [a] [b] -> CallCC (ListT m) a bSource

Lift a callCC operation to the new monad.

liftCatch :: Catch e m [a] -> Catch e (ListT m) aSource

Lift a catchE operation to the new monad.