Safe Haskell	None
Language	Haskell2010

Control.Effect.Carrier

Synopsis

class HFunctor h where
- fmap' :: (a -> b) -> h m a -> h m b
- hmap :: (forall x. m x -> n x) -> h m a -> h n a
class HFunctor sig => Effect sig where
- handle :: Functor f => f () -> (forall x. f (m x) -> n (f x)) -> sig m (m a) -> sig n (n (f a))
class HFunctor sig => Carrier sig h | h -> sig where
- ret :: a -> h a
- eff :: sig h (h a) -> h a
handlePure :: HFunctor sig => (forall x. f x -> g x) -> sig f (f a) -> sig g (g a)
handleCoercible :: (HFunctor sig, Coercible f g) => sig f (f a) -> sig g (g a)
handleReader :: HFunctor sig => r -> (forall x. f x -> r -> g x) -> sig f (f a) -> sig g (g a)
handleState :: Effect sig => s -> (forall x. f x -> s -> g (s, x)) -> sig f (f a) -> sig g (g (s, a))
handleEither :: (Carrier sig g, Effect sig) => (forall x. f x -> g (Either e x)) -> sig f (f a) -> sig g (g (Either e a))
handleTraversable :: (Effect sig, Applicative g, Monad m, Traversable m) => (forall x. f x -> g (m x)) -> sig f (f a) -> sig g (g (m a))

Documentation

class HFunctor h where #

Minimal complete definition

hmap

Methods

fmap' :: (a -> b) -> h m a -> h m b #

Functor map. This is required to be fmap.

This can go away once we have quantified constraints.

fmap' :: Functor (h m) => (a -> b) -> h m a -> h m b #

Functor map. This is required to be fmap.

This can go away once we have quantified constraints.

hmap :: (forall x. m x -> n x) -> h m a -> h n a #

Higher-order functor map of a natural transformation over higher-order positions within the effect.

Instances

HFunctor Fail #
Instance details Defined in Control.Effect.Fail.Internal Methods fmap' :: (a -> b) -> Fail m a -> Fail m b # hmap :: (forall x. m x -> n x) -> Fail m a -> Fail n a #
HFunctor NonDet #
Instance details Defined in Control.Effect.NonDet.Internal Methods fmap' :: (a -> b) -> NonDet m a -> NonDet m b # hmap :: (forall x. m x -> n x) -> NonDet m a -> NonDet n a #
HFunctor Random #
Instance details Defined in Control.Effect.Random.Internal Methods fmap' :: (a -> b) -> Random m a -> Random m b # hmap :: (forall x. m x -> n x) -> Random m a -> Random n a #
HFunctor Resource #
Instance details Defined in Control.Effect.Resource Methods fmap' :: (a -> b) -> Resource m a -> Resource m b # hmap :: (forall x. m x -> n x) -> Resource m a -> Resource n a #
HFunctor Fresh #
Instance details Defined in Control.Effect.Fresh Methods fmap' :: (a -> b) -> Fresh m a -> Fresh m b # hmap :: (forall x. m x -> n x) -> Fresh m a -> Fresh n a #
HFunctor Cull #
Instance details Defined in Control.Effect.Cull Methods fmap' :: (a -> b) -> Cull m a -> Cull m b # hmap :: (forall x. m x -> n x) -> Cull m a -> Cull n a #
HFunctor Cut #
Instance details Defined in Control.Effect.Cut Methods fmap' :: (a -> b) -> Cut m a -> Cut m b # hmap :: (forall x. m x -> n x) -> Cut m a -> Cut n a #
HFunctor Trace #
Instance details Defined in Control.Effect.Trace Methods fmap' :: (a -> b) -> Trace m a -> Trace m b # hmap :: (forall x. m x -> n x) -> Trace m a -> Trace n a #
HFunctor Void #
Instance details Defined in Control.Effect.Void Methods fmap' :: (a -> b) -> Void m a -> Void m b # hmap :: (forall x. m x -> n x) -> Void m a -> Void n a #
Functor sig => HFunctor (Lift sig) #
Instance details Defined in Control.Effect.Lift.Internal Methods fmap' :: (a -> b) -> Lift sig m a -> Lift sig m b # hmap :: (forall x. m x -> n x) -> Lift sig m a -> Lift sig n a #
HFunctor (State s) #
Instance details Defined in Control.Effect.State Methods fmap' :: (a -> b) -> State s m a -> State s m b # hmap :: (forall x. m x -> n x) -> State s m a -> State s n a #
HFunctor (Resumable err) #
Instance details Defined in Control.Effect.Resumable Methods fmap' :: (a -> b) -> Resumable err m a -> Resumable err m b # hmap :: (forall x. m x -> n x) -> Resumable err m a -> Resumable err n a #
HFunctor (Reader r) #
Instance details Defined in Control.Effect.Reader Methods fmap' :: (a -> b) -> Reader r m a -> Reader r m b # hmap :: (forall x. m x -> n x) -> Reader r m a -> Reader r n a #
HFunctor (Error exc) #
Instance details Defined in Control.Effect.Error Methods fmap' :: (a -> b) -> Error exc m a -> Error exc m b # hmap :: (forall x. m x -> n x) -> Error exc m a -> Error exc n a #
HFunctor (Writer w) #
Instance details Defined in Control.Effect.Writer Methods fmap' :: (a -> b) -> Writer w m a -> Writer w m b # hmap :: (forall x. m x -> n x) -> Writer w m a -> Writer w n a #
(HFunctor l, HFunctor r) => HFunctor (l :+: r) #
Instance details Defined in Control.Effect.Sum Methods fmap' :: (a -> b) -> (l :+: r) m a -> (l :+: r) m b # hmap :: (forall x. m x -> n x) -> (l :+: r) m a -> (l :+: r) n a #

class HFunctor sig => Effect sig where #

The class of effect types, which must:

Be functorial in their last two arguments, and
Support threading effects in higher-order positions through using the carrier’s suspended state.

Methods

handle :: Functor f => f () -> (forall x. f (m x) -> n (f x)) -> sig m (m a) -> sig n (n (f a)) #

Handle any effects in a signature by threading the carrier’s state all the way through to the continuation.

Instances

Effect Fail #
Instance details Defined in Control.Effect.Fail.Internal Methods handle :: Functor f => f () -> (forall x. f (m x) -> n (f x)) -> Fail m (m a) -> Fail n (n (f a)) #
Effect NonDet #
Instance details Defined in Control.Effect.NonDet.Internal Methods handle :: Functor f => f () -> (forall x. f (m x) -> n (f x)) -> NonDet m (m a) -> NonDet n (n (f a)) #
Effect Random #
Instance details Defined in Control.Effect.Random.Internal Methods handle :: Functor f => f () -> (forall x. f (m x) -> n (f x)) -> Random m (m a) -> Random n (n (f a)) #
Effect Resource #
Instance details Defined in Control.Effect.Resource Methods handle :: Functor f => f () -> (forall x. f (m x) -> n (f x)) -> Resource m (m a) -> Resource n (n (f a)) #
Effect Fresh #
Instance details Defined in Control.Effect.Fresh Methods handle :: Functor f => f () -> (forall x. f (m x) -> n (f x)) -> Fresh m (m a) -> Fresh n (n (f a)) #
Effect Cull #
Instance details Defined in Control.Effect.Cull Methods handle :: Functor f => f () -> (forall x. f (m x) -> n (f x)) -> Cull m (m a) -> Cull n (n (f a)) #
Effect Cut #
Instance details Defined in Control.Effect.Cut Methods handle :: Functor f => f () -> (forall x. f (m x) -> n (f x)) -> Cut m (m a) -> Cut n (n (f a)) #
Effect Trace #
Instance details Defined in Control.Effect.Trace Methods handle :: Functor f => f () -> (forall x. f (m x) -> n (f x)) -> Trace m (m a) -> Trace n (n (f a)) #
Effect Void #
Instance details Defined in Control.Effect.Void Methods handle :: Functor f => f () -> (forall x. f (m x) -> n (f x)) -> Void m (m a) -> Void n (n (f a)) #
Functor sig => Effect (Lift sig) #
Instance details Defined in Control.Effect.Lift.Internal Methods handle :: Functor f => f () -> (forall x. f (m x) -> n (f x)) -> Lift sig m (m a) -> Lift sig n (n (f a)) #
Effect (State s) #
Instance details Defined in Control.Effect.State Methods handle :: Functor f => f () -> (forall x. f (m x) -> n (f x)) -> State s m (m a) -> State s n (n (f a)) #
Effect (Resumable err) #
Instance details Defined in Control.Effect.Resumable Methods handle :: Functor f => f () -> (forall x. f (m x) -> n (f x)) -> Resumable err m (m a) -> Resumable err n (n (f a)) #
Effect (Reader r) #
Instance details Defined in Control.Effect.Reader Methods handle :: Functor f => f () -> (forall x. f (m x) -> n (f x)) -> Reader r m (m a) -> Reader r n (n (f a)) #
Effect (Error exc) #
Instance details Defined in Control.Effect.Error Methods handle :: Functor f => f () -> (forall x. f (m x) -> n (f x)) -> Error exc m (m a) -> Error exc n (n (f a)) #
Effect (Writer w) #
Instance details Defined in Control.Effect.Writer Methods handle :: Functor f => f () -> (forall x. f (m x) -> n (f x)) -> Writer w m (m a) -> Writer w n (n (f a)) #
(Effect l, Effect r) => Effect (l :+: r) #
Instance details Defined in Control.Effect.Sum Methods handle :: Functor f => f () -> (forall x. f (m x) -> n (f x)) -> (l :+: r) m (m a) -> (l :+: r) n (n (f a)) #

class HFunctor sig => Carrier sig h | h -> sig where #

The class of carriers (results) for algebras (effect handlers) over signatures (effects), whose actions are given by the ret and eff methods.

Methods

ret :: a -> h a #

Wrap a return value.

eff :: sig h (h a) -> h a #

Construct a value in the carrier for an effect signature (typically a sum of a handled effect and any remaining effects).

Instances

Carrier Void VoidC #
Instance details Defined in Control.Effect.Void Methods ret :: a -> VoidC a # eff :: Void VoidC (VoidC a) -> VoidC a #
Carrier sig carrier => Carrier sig (Eff carrier) #
Instance details Defined in Control.Effect.Internal Methods ret :: a -> Eff carrier a # eff :: sig (Eff carrier) (Eff carrier a) -> Eff carrier a #
Monad m => Carrier (Lift m) (LiftC m) #
Instance details Defined in Control.Effect.Lift Methods ret :: a -> LiftC m a # eff :: Lift m (LiftC m) (LiftC m a) -> LiftC m a #
(Carrier sig m, Effect sig) => Carrier (Fail :+: sig) (FailC m) #
Instance details Defined in Control.Effect.Fail Methods ret :: a -> FailC m a # eff :: (Fail :+: sig) (FailC m) (FailC m a) -> FailC m a #
(Carrier sig m, MonadIO m) => Carrier (Resource :+: sig) (ResourceC m) #
Instance details Defined in Control.Effect.Resource Methods ret :: a -> ResourceC m a # eff :: (Resource :+: sig) (ResourceC m) (ResourceC m a) -> ResourceC m a #
(Carrier sig m, Effect sig, Monad m) => Carrier (Fresh :+: sig) (FreshC m) #
Instance details Defined in Control.Effect.Fresh Methods ret :: a -> FreshC m a # eff :: (Fresh :+: sig) (FreshC m) (FreshC m a) -> FreshC m a #
(Alternative m, Carrier sig m, Effect sig, Monad m) => Carrier (Cull :+: (NonDet :+: sig)) (CullC m) #
Instance details Defined in Control.Effect.Cull Methods ret :: a -> CullC m a # eff :: (Cull :+: (NonDet :+: sig)) (CullC m) (CullC m a) -> CullC m a #
(Alternative m, Carrier sig m, Effect sig, Monad m) => Carrier (Cut :+: (NonDet :+: sig)) (CutC m) #
Instance details Defined in Control.Effect.Cut Methods ret :: a -> CutC m a # eff :: (Cut :+: (NonDet :+: sig)) (CutC m) (CutC m a) -> CutC m a #
(Carrier sig m, Effect sig) => Carrier (Trace :+: sig) (TraceByReturningC m) #
Instance details Defined in Control.Effect.Trace Methods ret :: a -> TraceByReturningC m a # eff :: (Trace :+: sig) (TraceByReturningC m) (TraceByReturningC m a) -> TraceByReturningC m a #
Carrier sig m => Carrier (Trace :+: sig) (TraceByIgnoringC m) #
Instance details Defined in Control.Effect.Trace Methods ret :: a -> TraceByIgnoringC m a # eff :: (Trace :+: sig) (TraceByIgnoringC m) (TraceByIgnoringC m a) -> TraceByIgnoringC m a #
(MonadIO m, Carrier sig m) => Carrier (Trace :+: sig) (TraceByPrintingC m) #
Instance details Defined in Control.Effect.Trace Methods ret :: a -> TraceByPrintingC m a # eff :: (Trace :+: sig) (TraceByPrintingC m) (TraceByPrintingC m a) -> TraceByPrintingC m a #
(Alternative f, Carrier sig m, Effect sig, Traversable f, Monad f, Monad m) => Carrier (NonDet :+: sig) (OnceC f m) #
Instance details Defined in Control.Effect.NonDet Methods ret :: a -> OnceC f m a # eff :: (NonDet :+: sig) (OnceC f m) (OnceC f m a) -> OnceC f m a #
(Alternative f, Monad f, Traversable f, Carrier sig m, Effect sig, Applicative m) => Carrier (NonDet :+: sig) (AltC f m) #
Instance details Defined in Control.Effect.NonDet Methods ret :: a -> AltC f m a # eff :: (NonDet :+: sig) (AltC f m) (AltC f m a) -> AltC f m a #
(Carrier sig m, Effect sig, RandomGen g, Monad m) => Carrier (Random :+: sig) (RandomC g m) #
Instance details Defined in Control.Effect.Random Methods ret :: a -> RandomC g m a # eff :: (Random :+: sig) (RandomC g m) (RandomC g m a) -> RandomC g m a #
(Carrier sig m, Effect sig) => Carrier (State s :+: sig) (StateC s m) #
Instance details Defined in Control.Effect.State Methods ret :: a -> StateC s m a # eff :: (State s :+: sig) (StateC s m) (StateC s m a) -> StateC s m a #
(Carrier sig m, Monad m) => Carrier (Resumable err :+: sig) (ResumableWithC err m) #
Instance details Defined in Control.Effect.Resumable Methods ret :: a -> ResumableWithC err m a # eff :: (Resumable err :+: sig) (ResumableWithC err m) (ResumableWithC err m a) -> ResumableWithC err m a #
(Carrier sig m, Effect sig) => Carrier (Resumable err :+: sig) (ResumableC err m) #
Instance details Defined in Control.Effect.Resumable Methods ret :: a -> ResumableC err m a # eff :: (Resumable err :+: sig) (ResumableC err m) (ResumableC err m a) -> ResumableC err m a #
(Carrier sig m, Monad m) => Carrier (Reader r :+: sig) (ReaderC r m) #
Instance details Defined in Control.Effect.Reader Methods ret :: a -> ReaderC r m a # eff :: (Reader r :+: sig) (ReaderC r m) (ReaderC r m a) -> ReaderC r m a #
(Carrier sig m, Effect sig, Monad m) => Carrier (Error e :+: sig) (ErrorC e m) #
Instance details Defined in Control.Effect.Error Methods ret :: a -> ErrorC e m a # eff :: (Error e :+: sig) (ErrorC e m) (ErrorC e m a) -> ErrorC e m a #
(Monoid w, Carrier sig m, Effect sig, Functor m) => Carrier (Writer w :+: sig) (WriterC w m) #
Instance details Defined in Control.Effect.Writer Methods ret :: a -> WriterC w m a # eff :: (Writer w :+: sig) (WriterC w m) (WriterC w m a) -> WriterC w m a #

handlePure :: HFunctor sig => (forall x. f x -> g x) -> sig f (f a) -> sig g (g a) #

Apply a handler specified as a natural transformation to both higher-order and continuation positions within an HFunctor.

handleCoercible :: (HFunctor sig, Coercible f g) => sig f (f a) -> sig g (g a) #

Thread a Coercible carrier through an HFunctor.

This is applicable whenever f is Coercible to g, e.g. simple newtypes.

handleReader :: HFunctor sig => r -> (forall x. f x -> r -> g x) -> sig f (f a) -> sig g (g a) #

Thread a Reader-like carrier through an HFunctor.

handleState :: Effect sig => s -> (forall x. f x -> s -> g (s, x)) -> sig f (f a) -> sig g (g (s, a)) #

Thread a State-like carrier through an Effect.

handleEither :: (Carrier sig g, Effect sig) => (forall x. f x -> g (Either e x)) -> sig f (f a) -> sig g (g (Either e a)) #

Thread a carrier producing Eithers through an Effect.

handleTraversable :: (Effect sig, Applicative g, Monad m, Traversable m) => (forall x. f x -> g (m x)) -> sig f (f a) -> sig g (g (m a)) #

Thread a carrier producing values in a Traversable Monad (e.g. '[]') through an Effect.