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, Monad m) => Carrier sig m | m -> sig where
- eff :: sig m (m a) -> m a
- ret :: a -> m 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))
interpret :: carrier a -> carrier a

Documentation

class HFunctor h where Source #

Minimal complete definition

hmap

Methods

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

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 Source #

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 Source #

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

Instances

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

class HFunctor sig => Effect sig where Source #

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)) Source #

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

Instances

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

class (HFunctor sig, Monad m) => Carrier sig m | m -> sig where Source #

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

Minimal complete definition

eff

Methods

eff :: sig m (m a) -> m a Source #

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

ret :: a -> m a Source #

Deprecated: Use pure instead; ret is a historical alias and will be removed in future versions

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

Instances

Carrier Pure PureC Source #
Instance details Defined in Control.Effect.Pure Methods eff :: Pure PureC (PureC a) -> PureC a Source # ret :: a -> PureC a Source #
Monad m => Carrier (Lift m) (LiftC m) Source #
Instance details Defined in Control.Effect.Lift Methods eff :: Lift m (LiftC m) (LiftC m a) -> LiftC m a Source # ret :: a -> LiftC m a Source #
(Carrier sig m, MonadIO m) => Carrier (Resource :+: sig) (ResourceC m) Source #
Instance details Defined in Control.Effect.Resource Methods eff :: (Resource :+: sig) (ResourceC m) (ResourceC m a) -> ResourceC m a Source # ret :: a -> ResourceC m a Source #
(Carrier sig m, Effect sig) => Carrier (NonDet :+: sig) (NonDetC m) Source #
Instance details Defined in Control.Effect.NonDet Methods eff :: (NonDet :+: sig) (NonDetC m) (NonDetC m a) -> NonDetC m a Source # ret :: a -> NonDetC m a Source #
(Carrier sig m, Effect sig) => Carrier (NonDet :+: sig) (OnceC m) Source #
Instance details Defined in Control.Effect.Cull Methods eff :: (NonDet :+: sig) (OnceC m) (OnceC m a) -> OnceC m a Source # ret :: a -> OnceC m a Source #
(Carrier sig m, Effect sig) => Carrier (Fresh :+: sig) (FreshC m) Source #
Instance details Defined in Control.Effect.Fresh Methods eff :: (Fresh :+: sig) (FreshC m) (FreshC m a) -> FreshC m a Source # ret :: a -> FreshC m a Source #
(Carrier sig m, Effect sig) => Carrier (Fail :+: sig) (FailC m) Source #
Instance details Defined in Control.Effect.Fail Methods eff :: (Fail :+: sig) (FailC m) (FailC m a) -> FailC m a Source # ret :: a -> FailC m a Source #
(Carrier sig m, Effect sig) => Carrier (Cut :+: (NonDet :+: sig)) (CutC m) Source #
Instance details Defined in Control.Effect.Cut Methods eff :: (Cut :+: (NonDet :+: sig)) (CutC m) (CutC m a) -> CutC m a Source # ret :: a -> CutC m a Source #
(Carrier sig m, Effect sig) => Carrier (Cull :+: (NonDet :+: sig)) (CullC m) Source #
Instance details Defined in Control.Effect.Cull Methods eff :: (Cull :+: (NonDet :+: sig)) (CullC m) (CullC m a) -> CullC m a Source # ret :: a -> CullC m a Source #
(Carrier sig m, Effect sig) => Carrier (Trace :+: sig) (TraceByReturningC m) Source #
Instance details Defined in Control.Effect.Trace Methods eff :: (Trace :+: sig) (TraceByReturningC m) (TraceByReturningC m a) -> TraceByReturningC m a Source # ret :: a -> TraceByReturningC m a Source #
Carrier sig m => Carrier (Trace :+: sig) (TraceByIgnoringC m) Source #
Instance details Defined in Control.Effect.Trace Methods eff :: (Trace :+: sig) (TraceByIgnoringC m) (TraceByIgnoringC m a) -> TraceByIgnoringC m a Source # ret :: a -> TraceByIgnoringC m a Source #
(MonadIO m, Carrier sig m) => Carrier (Trace :+: sig) (TraceByPrintingC m) Source #
Instance details Defined in Control.Effect.Trace Methods eff :: (Trace :+: sig) (TraceByPrintingC m) (TraceByPrintingC m a) -> TraceByPrintingC m a Source # ret :: a -> TraceByPrintingC m a Source #
(Carrier sig m, Effect sig) => Carrier (State s :+: sig) (StateC s m) Source #
Instance details Defined in Control.Effect.State.Strict Methods eff :: (State s :+: sig) (StateC s m) (StateC s m a) -> StateC s m a Source # ret :: a -> StateC s m a Source #
(Carrier sig m, Effect sig) => Carrier (State s :+: sig) (StateC s m) Source #
Instance details Defined in Control.Effect.State.Lazy Methods eff :: (State s :+: sig) (StateC s m) (StateC s m a) -> StateC s m a Source # ret :: a -> StateC s m a Source #
Carrier sig m => Carrier (Reader r :+: sig) (ReaderC r m) Source #
Instance details Defined in Control.Effect.Reader Methods eff :: (Reader r :+: sig) (ReaderC r m) (ReaderC r m a) -> ReaderC r m a Source # ret :: a -> ReaderC r m a Source #
(Carrier sig m, Effect sig, RandomGen g) => Carrier (Random :+: sig) (RandomC g m) Source #
Instance details Defined in Control.Effect.Random Methods eff :: (Random :+: sig) (RandomC g m) (RandomC g m a) -> RandomC g m a Source # ret :: a -> RandomC g m a Source #
(Carrier sig m, Effect sig) => Carrier (Error e :+: sig) (ErrorC e m) Source #
Instance details Defined in Control.Effect.Error Methods eff :: (Error e :+: sig) (ErrorC e m) (ErrorC e m a) -> ErrorC e m a Source # ret :: a -> ErrorC e m a Source #
Carrier sig m => Carrier (Resumable err :+: sig) (ResumableWithC err m) Source #
Instance details Defined in Control.Effect.Resumable Methods eff :: (Resumable err :+: sig) (ResumableWithC err m) (ResumableWithC err m a) -> ResumableWithC err m a Source # ret :: a -> ResumableWithC err m a Source #
(Carrier sig m, Effect sig) => Carrier (Resumable err :+: sig) (ResumableC err m) Source #
Instance details Defined in Control.Effect.Resumable Methods eff :: (Resumable err :+: sig) (ResumableC err m) (ResumableC err m a) -> ResumableC err m a Source # ret :: a -> ResumableC err m a Source #
(Monoid w, Carrier sig m, Effect sig) => Carrier (Writer w :+: sig) (WriterC w m) Source #
Instance details Defined in Control.Effect.Writer Methods eff :: (Writer w :+: sig) (WriterC w m) (WriterC w m a) -> WriterC w m a Source # ret :: a -> WriterC w m a Source #

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

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) Source #

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) Source #

Deprecated: Compose carrier types from other carriers and define eff with handleCoercible instead

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)) Source #

Deprecated: Compose carrier types from other carriers and define eff with handleCoercible instead

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)) Source #

Deprecated: Compose carrier types from other carriers and define eff with handleCoercible instead

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)) Source #

Deprecated: Compose carrier types from other carriers and define eff with handleCoercible instead

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

interpret :: carrier a -> carrier a Source #

Deprecated: Not necessary with monadic carriers; remove or replace with id.

A backwards-compatibility shim, equivalent to id.