Control.Effect.Type.Mask

Effects

data Mask :: Effect where

An effect for masking asynchronous exceptions.

Mask is typically used as a primitive effect. If you define a Carrier that relies on a novel non-trivial monad transformer t, then you need to make a ThreadsEff t Mask instance (if possible). threadMaskViaClass can help you with that.

The following threading constraints accept Mask:

• ReaderThreads
• StateThreads
• StateLazyThreads
• ErrorThreads
• WriterThreads
• WriterLazyThreads

Constructors

Mask :: MaskMode -> ((forall x. m x -> m x) -> m a) -> Mask m a

Instances

ThreadsEff (ExceptT e) Mask

Defined in Control.Effect.Type.Mask

Methods

threadEff :: Monad m => (forall x. Mask m x -> m x) -> Mask (ExceptT e m) a -> ExceptT e m a

Monoid s => ThreadsEff (WriterT s) Mask

Defined in Control.Effect.Type.Mask

Methods

threadEff :: Monad m => (forall x. Mask m x -> m x) -> Mask (WriterT s m) a -> WriterT s m a

ThreadsEff (StateT s) Mask

Defined in Control.Effect.Type.Mask

Methods

threadEff :: Monad m => (forall x. Mask m x -> m x) -> Mask (StateT s m) a -> StateT s m a

ThreadsEff (ReaderT i) Mask

Defined in Control.Effect.Type.Mask

Methods

threadEff :: Monad m => (forall x. Mask m x -> m x) -> Mask (ReaderT i m) a -> ReaderT i m a

ThreadsEff (StateT s) Mask

Defined in Control.Effect.Type.Mask

Methods

threadEff :: Monad m => (forall x. Mask m x -> m x) -> Mask (StateT s m) a -> StateT s m a

Monoid s => ThreadsEff (WriterT s) Mask

Defined in Control.Effect.Type.Mask

Methods

threadEff :: Monad m => (forall x. Mask m x -> m x) -> Mask (WriterT s m) a -> WriterT s m a

Monoid s => ThreadsEff (WriterT s) Mask

Defined in Control.Effect.Type.Mask

Methods

threadEff :: Monad m => (forall x. Mask m x -> m x) -> Mask (WriterT s m) a -> WriterT s m a

Monad m => MonadThrow (ViaAlg s Mask m)

Defined in Control.Effect.Type.Mask

Methods

throwM :: Exception e => e -> ViaAlg s Mask m a

Monad m => MonadCatch (ViaAlg s Mask m)

Defined in Control.Effect.Type.Mask

Methods

catch :: Exception e => ViaAlg s Mask m a -> (e -> ViaAlg s Mask m a) -> ViaAlg s Mask m a

(Reifies s (ReifiedEffAlgebra Mask m), Monad m) => MonadMask (ViaAlg s Mask m)

Defined in Control.Effect.Type.Mask

Methods

mask :: ((forall a. ViaAlg s Mask m a -> ViaAlg s Mask m a) -> ViaAlg s Mask m b) -> ViaAlg s Mask m b

uninterruptibleMask :: ((forall a. ViaAlg s Mask m a -> ViaAlg s Mask m a) -> ViaAlg s Mask m b) -> ViaAlg s Mask m b

generalBracket :: ViaAlg s Mask m a -> (a -> ExitCase b -> ViaAlg s Mask m c) -> (a -> ViaAlg s Mask m b) -> ViaAlg s Mask m (b, c)

data MaskMode

Constructors

InterruptibleMask

UninterruptibleMask

Threading utilities

threadMaskViaClass :: forall t m a. Monad m => (RepresentationalT t, forall b. MonadMask b => MonadMask (t b)) => (forall x. Mask m x -> m x) -> Mask (t m) a -> t m a

A valid definition of threadEff for a ThreadsEff t Mask instance, given that t lifts MonadMask.

BEWARE: threadMaskViaClass is only safe if the implementation of mask and uninterruptibleMask for t m only makes use of mask and uninterruptibleMask for m, and no other methods of MonadThrow, MonadCatch, and MonadMask.