type Rep1 (MaybeT m :: Type -> Type)
Instance details Defined in Control.Monad.Trans.Maybe type Rep1 (MaybeT m :: Type -> Type) = D1 ('MetaData "MaybeT" "Control.Monad.Trans.Maybe" "transformers-0.6.1.0-inplace" 'True) (C1 ('MetaCons "MaybeT" 'PrefixI 'True) (S1 ('MetaSel ('Just "runMaybeT") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (m :.: Rec1 Maybe)))

Methods

from1 :: MaybeT m a -> Rep1 (MaybeT m) a #

to1 :: Rep1 (MaybeT m) a -> MaybeT m a #

Monad m => MonadFail (MaybeT m)

Instance details

Defined in Control.Monad.Trans.Maybe

Methods

fail :: String -> MaybeT m a #

MonadFix m => MonadFix (MaybeT m)

Instance details

Defined in Control.Monad.Trans.Maybe

Methods

mfix :: (a -> MaybeT m a) -> MaybeT m a #

MonadIO m => MonadIO (MaybeT m)

Instance details

Defined in Control.Monad.Trans.Maybe

Methods

liftIO :: IO a -> MaybeT m a #

MonadZip m => MonadZip (MaybeT m)

Instance details

Defined in Control.Monad.Trans.Maybe

Methods

mzip :: MaybeT m a -> MaybeT m b -> MaybeT m (a, b) #

mzipWith :: (a -> b -> c) -> MaybeT m a -> MaybeT m b -> MaybeT m c #

munzip :: MaybeT m (a, b) -> (MaybeT m a, MaybeT m b) #

Foldable f => Foldable (MaybeT f)

Instance details

Defined in Control.Monad.Trans.Maybe

Methods

fold :: Monoid m => MaybeT f m -> m #

foldMap :: Monoid m => (a -> m) -> MaybeT f a -> m #

foldMap' :: Monoid m => (a -> m) -> MaybeT f a -> m #

foldr :: (a -> b -> b) -> b -> MaybeT f a -> b #

foldr' :: (a -> b -> b) -> b -> MaybeT f a -> b #

foldl :: (b -> a -> b) -> b -> MaybeT f a -> b #

foldl' :: (b -> a -> b) -> b -> MaybeT f a -> b #

foldr1 :: (a -> a -> a) -> MaybeT f a -> a #

foldl1 :: (a -> a -> a) -> MaybeT f a -> a #

toList :: MaybeT f a -> [a] #

null :: MaybeT f a -> Bool #

length :: MaybeT f a -> Int #

elem :: Eq a => a -> MaybeT f a -> Bool #

maximum :: Ord a => MaybeT f a -> a #

minimum :: Ord a => MaybeT f a -> a #

sum :: Num a => MaybeT f a -> a #

product :: Num a => MaybeT f a -> a #

Eq1 m => Eq1 (MaybeT m)

Instance details

Defined in Control.Monad.Trans.Maybe

Methods

liftEq :: (a -> b -> Bool) -> MaybeT m a -> MaybeT m b -> Bool #

Ord1 m => Ord1 (MaybeT m)

Instance details

Defined in Control.Monad.Trans.Maybe

Methods

liftCompare :: (a -> b -> Ordering) -> MaybeT m a -> MaybeT m b -> Ordering #

Read1 m => Read1 (MaybeT m)

Instance details

Defined in Control.Monad.Trans.Maybe

Methods

liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (MaybeT m a) #

liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [MaybeT m a] #

liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (MaybeT m a) #

liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [MaybeT m a] #

Show1 m => Show1 (MaybeT m)

Instance details

Defined in Control.Monad.Trans.Maybe

Methods

liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> MaybeT m a -> ShowS #

liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [MaybeT m a] -> ShowS #

Contravariant m => Contravariant (MaybeT m)

Instance details

Defined in Control.Monad.Trans.Maybe

Methods

contramap :: (a' -> a) -> MaybeT m a -> MaybeT m a' #

(>$) :: b -> MaybeT m b -> MaybeT m a #

Traversable f => Traversable (MaybeT f)

Instance details

Defined in Control.Monad.Trans.Maybe

Methods

traverse :: Applicative f0 => (a -> f0 b) -> MaybeT f a -> f0 (MaybeT f b) #

sequenceA :: Applicative f0 => MaybeT f (f0 a) -> f0 (MaybeT f a) #

mapM :: Monad m => (a -> m b) -> MaybeT f a -> m (MaybeT f b) #

sequence :: Monad m => MaybeT f (m a) -> m (MaybeT f a) #

(Functor m, Monad m) => Alternative (MaybeT m)

Instance details

Defined in Control.Monad.Trans.Maybe

Methods

empty :: MaybeT m a #

(<|>) :: MaybeT m a -> MaybeT m a -> MaybeT m a #

some :: MaybeT m a -> MaybeT m [a] #

many :: MaybeT m a -> MaybeT m [a] #

(Functor m, Monad m) => Applicative (MaybeT m)

Instance details

Defined in Control.Monad.Trans.Maybe

Methods

pure :: a -> MaybeT m a #

(<*>) :: MaybeT m (a -> b) -> MaybeT m a -> MaybeT m b #

liftA2 :: (a -> b -> c) -> MaybeT m a -> MaybeT m b -> MaybeT m c #

(*>) :: MaybeT m a -> MaybeT m b -> MaybeT m b #

(<*) :: MaybeT m a -> MaybeT m b -> MaybeT m a #

Functor m => Functor (MaybeT m)

Instance details

Defined in Control.Monad.Trans.Maybe

Methods

fmap :: (a -> b) -> MaybeT m a -> MaybeT m b #

(<$) :: a -> MaybeT m b -> MaybeT m a #

Monad m => Monad (MaybeT m)

Instance details

Defined in Control.Monad.Trans.Maybe

Methods

(>>=) :: MaybeT m a -> (a -> MaybeT m b) -> MaybeT m b #

(>>) :: MaybeT m a -> MaybeT m b -> MaybeT m b #

return :: a -> MaybeT m a #

Monad m => MonadPlus (MaybeT m)

Instance details

Defined in Control.Monad.Trans.Maybe

Methods

mzero :: MaybeT m a #

mplus :: MaybeT m a -> MaybeT m a -> MaybeT m a #

Invariant m => Invariant (MaybeT m)

from the transformers package

Instance details

Defined in Data.Functor.Invariant

Methods

invmap :: (a -> b) -> (b -> a) -> MaybeT m a -> MaybeT m b #

MonadException m => MonadException (MaybeT m) Source #

Instance details

Defined in Control.Monad.Ology.Specific.MaybeT

Associated Types

type Exc (MaybeT m)
Instance details Defined in Control.Monad.Ology.Specific.MaybeT type Exc (MaybeT m) = Maybe (Exc m)

Methods

throwExc :: Exc (MaybeT m) -> MaybeT m a Source #

catchExc :: MaybeT m a -> (Exc (MaybeT m) -> MaybeT m a) -> MaybeT m a Source #

MonadInner m => MonadInner (MaybeT m) Source #

Instance details

Defined in Control.Monad.Ology.Specific.MaybeT

Methods

retrieveInner :: MaybeT m a -> Result (Exc (MaybeT m)) a Source #

MonadCatch e m => MonadCatch (Maybe e) (MaybeT m) Source #

Instance details

Defined in Control.Monad.Ology.Specific.MaybeT

Methods

catch :: MaybeT m a -> (Maybe e -> MaybeT m a) -> MaybeT m a Source #

MonadThrow e m => MonadThrow (Maybe e) (MaybeT m) Source #

Instance details

Defined in Control.Monad.Ology.Specific.MaybeT

Methods

throw :: Maybe e -> MaybeT m a Source #

Generic (MaybeT m a)

Instance details

Defined in Control.Monad.Trans.Maybe

Associated Types

type Rep (MaybeT m a)
Instance details Defined in Control.Monad.Trans.Maybe type Rep (MaybeT m a) = D1 ('MetaData "MaybeT" "Control.Monad.Trans.Maybe" "transformers-0.6.1.0-inplace" 'True) (C1 ('MetaCons "MaybeT" 'PrefixI 'True) (S1 ('MetaSel ('Just "runMaybeT") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (m (Maybe a)))))

Methods

from :: MaybeT m a -> Rep (MaybeT m a) x #

to :: Rep (MaybeT m a) x -> MaybeT m a #

(Read1 m, Read a) => Read (MaybeT m a)

Instance details

Defined in Control.Monad.Trans.Maybe

Methods

readsPrec :: Int -> ReadS (MaybeT m a) #

readList :: ReadS [MaybeT m a] #

readPrec :: ReadPrec (MaybeT m a) #

readListPrec :: ReadPrec [MaybeT m a] #

(Show1 m, Show a) => Show (MaybeT m a)

Instance details

Defined in Control.Monad.Trans.Maybe

Methods

showsPrec :: Int -> MaybeT m a -> ShowS #

show :: MaybeT m a -> String #

showList :: [MaybeT m a] -> ShowS #

(Eq1 m, Eq a) => Eq (MaybeT m a)

Instance details

Defined in Control.Monad.Trans.Maybe

Methods

(==) :: MaybeT m a -> MaybeT m a -> Bool #

(/=) :: MaybeT m a -> MaybeT m a -> Bool #

(Ord1 m, Ord a) => Ord (MaybeT m a)

Instance details

Defined in Control.Monad.Trans.Maybe

Methods

compare :: MaybeT m a -> MaybeT m a -> Ordering #

(<) :: MaybeT m a -> MaybeT m a -> Bool #

(<=) :: MaybeT m a -> MaybeT m a -> Bool #

(>) :: MaybeT m a -> MaybeT m a -> Bool #

(>=) :: MaybeT m a -> MaybeT m a -> Bool #

max :: MaybeT m a -> MaybeT m a -> MaybeT m a #

min :: MaybeT m a -> MaybeT m a -> MaybeT m a #

Lifting MonadIO MaybeT

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). MonadIO a :- MonadIO (MaybeT a) #

Lifting Foldable MaybeT

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). Foldable a :- Foldable (MaybeT a) #

Lifting Eq1 MaybeT

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). Eq1 a :- Eq1 (MaybeT a) #

Lifting Ord1 MaybeT

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). Ord1 a :- Ord1 (MaybeT a) #

Lifting Read1 MaybeT

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). Read1 a :- Read1 (MaybeT a) #

Lifting Show1 MaybeT

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). Show1 a :- Show1 (MaybeT a) #

Lifting Traversable MaybeT

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). Traversable a :- Traversable (MaybeT a) #

Lifting Functor MaybeT

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). Functor a :- Functor (MaybeT a) #

Lifting Monad MaybeT

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). Monad a :- Monad (MaybeT a) #

Lifting MonadPlus MaybeT

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). MonadPlus a :- MonadPlus (MaybeT a) #

Lifting MonadCont MaybeT

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). MonadCont a :- MonadCont (MaybeT a) #

Lifting (MonadError e :: (Type -> Type) -> Constraint) MaybeT

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). MonadError e a :- MonadError e (MaybeT a) #

Lifting (MonadReader r :: (Type -> Type) -> Constraint) MaybeT

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). MonadReader r a :- MonadReader r (MaybeT a) #

Lifting (MonadState s :: (Type -> Type) -> Constraint) MaybeT

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). MonadState s a :- MonadState s (MaybeT a) #

Lifting (MonadRWS r w s :: (Type -> Type) -> Constraint) MaybeT

Instance details

Defined in Data.Constraint.Lifting

Methods

lifting :: forall (a :: Type -> Type). MonadRWS r w s a :- MonadRWS r w s (MaybeT a) #

type Tunnel MaybeT Source #

Instance details

Defined in Control.Monad.Ology.Specific.MaybeT

type Tunnel MaybeT = Maybe

type Rep1 (MaybeT m :: Type -> Type)

Instance details

Defined in Control.Monad.Trans.Maybe

type Rep1 (MaybeT m :: Type -> Type) = D1 ('MetaData "MaybeT" "Control.Monad.Trans.Maybe" "transformers-0.6.1.0-inplace" 'True) (C1 ('MetaCons "MaybeT" 'PrefixI 'True) (S1 ('MetaSel ('Just "runMaybeT") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (m :.: Rec1 Maybe)))

type Exc (MaybeT m) Source #

Instance details

Defined in Control.Monad.Ology.Specific.MaybeT

type Exc (MaybeT m) = Maybe (Exc m)

type Rep (MaybeT m a)

Instance details

Defined in Control.Monad.Trans.Maybe

type Rep (MaybeT m a) = D1 ('MetaData "MaybeT" "Control.Monad.Trans.Maybe" "transformers-0.6.1.0-inplace" 'True) (C1 ('MetaCons "MaybeT" 'PrefixI 'True) (S1 ('MetaSel ('Just "runMaybeT") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (m (Maybe a)))))

mapMaybeT :: (m (Maybe a) -> n (Maybe b)) -> MaybeT m a -> MaybeT n b #

Transform the computation inside a MaybeT.

runMaybeT (mapMaybeT f m) = f (runMaybeT m)

hoistMaybe :: forall (m :: Type -> Type) b. Applicative m => Maybe b -> MaybeT m b #

Convert a Maybe computation to MaybeT.

maybeToExceptT :: forall (m :: Type -> Type) e a. Functor m => e -> MaybeT m a -> ExceptT e m a #

Convert a MaybeT computation to ExceptT, with a default exception value.

exceptToMaybeT :: forall (m :: Type -> Type) e a. Functor m => ExceptT e m a -> MaybeT m a #

Convert a ExceptT computation to MaybeT, discarding the value of any exception.

Orphan instances

MonadTransCoerce MaybeT Source #

Instance details

Methods

transCoerce :: forall (m1 :: Type -> Type) (m2 :: Type -> Type). Coercible m1 m2 => Dict (Coercible (MaybeT m1) (MaybeT m2)) Source #

MonadTransHoist MaybeT Source #

Instance details

Methods

hoist :: forall (m1 :: Type -> Type) (m2 :: Type -> Type). (Monad m1, Monad m2) => (m1 --> m2) -> MaybeT m1 --> MaybeT m2 Source #

MonadTransTunnel MaybeT Source #

Instance details

Associated Types

type Tunnel MaybeT
Instance details Defined in Control.Monad.Ology.Specific.MaybeT type Tunnel MaybeT = Maybe

Methods

tunnel :: Monad m => ((forall (m1 :: Type -> Type) a. Monad m1 => MaybeT m1 a -> m1 (Tunnel MaybeT a)) -> m (Tunnel MaybeT r)) -> MaybeT m r Source #

TransConstraint MonadFail MaybeT Source #

Instance details

Methods

hasTransConstraint :: forall (m :: Type -> Type). MonadFail m => Dict (MonadFail (MaybeT m)) Source #

TransConstraint MonadFix MaybeT Source #

Instance details

Methods

hasTransConstraint :: forall (m :: Type -> Type). MonadFix m => Dict (MonadFix (MaybeT m)) Source #

TransConstraint MonadIO MaybeT Source #

Instance details

Methods

hasTransConstraint :: forall (m :: Type -> Type). MonadIO m => Dict (MonadIO (MaybeT m)) Source #

TransConstraint Functor MaybeT Source #

Instance details

Methods

hasTransConstraint :: forall (m :: Type -> Type). Functor m => Dict (Functor (MaybeT m)) Source #

TransConstraint Monad MaybeT Source #

Instance details

Methods

hasTransConstraint :: forall (m :: Type -> Type). Monad m => Dict (Monad (MaybeT m)) Source #

TransConstraint MonadPlus MaybeT Source #

Instance details

Methods

hasTransConstraint :: forall (m :: Type -> Type). MonadPlus m => Dict (MonadPlus (MaybeT m)) Source #

TransConstraint MonadInner MaybeT Source #

Instance details

Methods

hasTransConstraint :: forall (m :: Type -> Type). MonadInner m => Dict (MonadInner (MaybeT m)) Source #

MonadException m => MonadException (MaybeT m) Source #

Instance details

Associated Types

type Exc (MaybeT m)
Instance details Defined in Control.Monad.Ology.Specific.MaybeT type Exc (MaybeT m) = Maybe (Exc m)

Methods

throwExc :: Exc (MaybeT m) -> MaybeT m a Source #

catchExc :: MaybeT m a -> (Exc (MaybeT m) -> MaybeT m a) -> MaybeT m a Source #

MonadInner m => MonadInner (MaybeT m) Source #

Instance details

Methods

retrieveInner :: MaybeT m a -> Result (Exc (MaybeT m)) a Source #

MonadCatch e m => MonadCatch (Maybe e) (MaybeT m) Source #

Instance details

Methods

catch :: MaybeT m a -> (Maybe e -> MaybeT m a) -> MaybeT m a Source #

MonadThrow e m => MonadThrow (Maybe e) (MaybeT m) Source #

Instance details

Methods

throw :: Maybe e -> MaybeT m a Source #