Control.Proxy.Trans.Maybe

This module provides the proxy transformer equivalent of MaybeT.

MaybeP

newtype MaybeP p a' a b' b m r

The Maybe proxy transformer

Constructors

MaybeP

Fields

• runMaybeP :: p a' a b' b m (Maybe r)

Instances

ProxyTrans MaybeP

Methods

liftP :: (Monad m, Proxy p) => p a' a b' b m r -> MaybeP p a' a b' b m r

PFunctor MaybeP

Methods

hoistP :: (Monad m, Proxy p1) => (forall r1. p1 a' a b' b m r1 -> p2 a' a b' b n r1) -> MaybeP p1 a' a b' b m r2 -> MaybeP p2 a' a b' b n r2

MonadIOP p => MonadIOP (MaybeP p)

Methods

liftIO_P :: MonadIO m => IO r -> MaybeP p a' a b' b m r

Proxy p => MonadPlusP (MaybeP p)

Methods

mzero_P :: Monad m => MaybeP p a' a b' b m r

mplus_P :: Monad m => MaybeP p a' a b' b m r -> MaybeP p a' a b' b m r -> MaybeP p a' a b' b m r

Proxy p => Proxy (MaybeP p)

Methods

request :: Monad m => a' -> MaybeP p a' a b' b m a

respond :: Monad m => b -> MaybeP p a' a b' b m b'

(>->) :: Monad m => (b' -> MaybeP p a' a b' b m r) -> (c' -> MaybeP p b' b c' c m r) -> c' -> MaybeP p a' a c' c m r

(>~>) :: Monad m => (a -> MaybeP p a' a b' b m r) -> (b -> MaybeP p b' b c' c m r) -> a -> MaybeP p a' a c' c m r

return_P :: Monad m => r -> MaybeP p a' a b' b m r

(?>=) :: Monad m => MaybeP p a' a b' b m r -> (r -> MaybeP p a' a b' b m r') -> MaybeP p a' a b' b m r'

lift_P :: Monad m => m r -> MaybeP p a' a b' b m r

hoist_P :: Monad m => (forall r. m r -> n r) -> MaybeP p a' a b' b m r' -> MaybeP p a' a b' b n r'

Proxy p => MonadTrans (MaybeP p a' a b' b)

Methods

lift :: Monad m => m a -> MaybeP p a' a b' b m a

Proxy p => MFunctor (MaybeP p a' a b' b)

Methods

hoist :: Monad m => (forall c. m c -> n c) -> MaybeP p a' a b' b m b -> MaybeP p a' a b' b n b

(Proxy p, Monad m) => Monad (MaybeP p a' a b' b m)

Methods

(>>=) :: MaybeP p a' a b' b m a -> (a -> MaybeP p a' a b' b m b) -> MaybeP p a' a b' b m b

(>>) :: MaybeP p a' a b' b m a -> MaybeP p a' a b' b m b -> MaybeP p a' a b' b m b

return :: a -> MaybeP p a' a b' b m a

fail :: String -> MaybeP p a' a b' b m a

(Proxy p, Monad m) => Functor (MaybeP p a' a b' b m)

Methods

fmap :: (a -> b) -> MaybeP p a' a b' b m a -> MaybeP p a' a b' b m b

(<$) :: a -> MaybeP p a' a b' b m b -> MaybeP p a' a b' b m a

(Proxy p, Monad m) => Applicative (MaybeP p a' a b' b m)

Methods

pure :: a -> MaybeP p a' a b' b m a

(<*>) :: MaybeP p a' a b' b m (a -> b) -> MaybeP p a' a b' b m a -> MaybeP p a' a b' b m b

(*>) :: MaybeP p a' a b' b m a -> MaybeP p a' a b' b m b -> MaybeP p a' a b' b m b

(<*) :: MaybeP p a' a b' b m a -> MaybeP p a' a b' b m b -> MaybeP p a' a b' b m a

(MonadIOP p, MonadIO m) => MonadIO (MaybeP p a' a b' b m)

Methods

liftIO :: IO a -> MaybeP p a' a b' b m a

(Proxy p, Monad m) => Alternative (MaybeP p a' a b' b m)

Methods

empty :: MaybeP p a' a b' b m a

(<|>) :: MaybeP p a' a b' b m a -> MaybeP p a' a b' b m a -> MaybeP p a' a b' b m a

some :: MaybeP p a' a b' b m a -> MaybeP p a' a b' b m [a]

many :: MaybeP p a' a b' b m a -> MaybeP p a' a b' b m [a]

(Proxy p, Monad m) => MonadPlus (MaybeP p a' a b' b m)

Methods

mzero :: MaybeP p a' a b' b m a

mplus :: MaybeP p a' a b' b m a -> MaybeP p a' a b' b m a -> MaybeP p a' a b' b m a

runMaybeK :: (q -> MaybeP p a' a b' b m r) -> q -> p a' a b' b m (Maybe r)

Run a MaybeP 'K'leisli arrow, returning the result or Nothing

Maybe operations

nothing :: (Monad m, Proxy p) => MaybeP p a' a b' b m r

A synonym for mzero

just :: (Monad m, Proxy p) => r -> MaybeP p a' a b' b m r

A synonym for return