Safe Haskell	None
Language	Haskell2010

Control.Effect.Reader

Contents

Reader effect
Reader carrier
Re-exports

Synopsis

data Reader r m k
- = Ask (r -> m k)
- | forall b. Local (r -> r) (m b) (b -> m k)
ask :: (Member (Reader r) sig, Carrier sig m) => m r
asks :: (Member (Reader r) sig, Carrier sig m) => (r -> a) -> m a
local :: (Member (Reader r) sig, Carrier sig m) => (r -> r) -> m a -> m a
runReader :: r -> ReaderC r m a -> m a
newtype ReaderC r m a = ReaderC {
- runReaderC :: r -> m a
}
class (HFunctor sig, Monad m) => Carrier sig m | m -> sig
class Member (sub :: (* -> *) -> * -> *) sup
run :: PureC a -> a

Reader effect

data Reader r m k Source #

Constructors

Ask (r -> m k)
forall b. Local (r -> r) (m b) (b -> m k)

Instances

Instances details

Effect (Reader r) Source #
Instance details Defined in Control.Effect.Reader Methods handle :: (Functor f, Monad m) => f () -> (forall x. f (m x) -> n (f x)) -> Reader r m a -> Reader r n (f a) Source #
HFunctor (Reader r) Source #
Instance details Defined in Control.Effect.Reader Methods fmap' :: forall (f :: Type -> Type) a b. Functor (Reader r f) => (a -> b) -> Reader r f a -> Reader r f b Source # hmap :: Functor m => (forall x. m x -> n x) -> Reader r m a -> Reader r n a Source #
Functor m => Functor (Reader r m) Source #
Instance details Defined in Control.Effect.Reader Methods fmap :: (a -> b) -> Reader r m a -> Reader r m b # (<$) :: a -> Reader r m b -> Reader r m a #
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) a -> ReaderC r m a Source #

ask :: (Member (Reader r) sig, Carrier sig m) => m r Source #

Retrieve the environment value.

run (runReader a ask) === a

asks :: (Member (Reader r) sig, Carrier sig m) => (r -> a) -> m a Source #

Project a function out of the current environment value.

snd (run (runReader a (asks (applyFun f)))) === applyFun f a

local :: (Member (Reader r) sig, Carrier sig m) => (r -> r) -> m a -> m a Source #

Run a computation with an environment value locally modified by the passed function.

run (runReader a (local (applyFun f) ask)) === applyFun f a

run (runReader a ((,,) <$> ask <*> local (applyFun f) ask <*> ask)) === (a, applyFun f a, a)

Reader carrier

runReader :: r -> ReaderC r m a -> m a Source #

Run a Reader effect with the passed environment value.

run (runReader a (pure b)) === b

newtype ReaderC r m a Source #

Constructors

ReaderC
Fields runReaderC :: r -> m a

Instances

Instances details

MonadTrans (ReaderC r) Source #
Instance details Defined in Control.Effect.Reader Methods lift :: Monad m => m a -> ReaderC r m a #
Monad m => Monad (ReaderC r m) Source #
Instance details Defined in Control.Effect.Reader Methods (>>=) :: ReaderC r m a -> (a -> ReaderC r m b) -> ReaderC r m b # (>>) :: ReaderC r m a -> ReaderC r m b -> ReaderC r m b # return :: a -> ReaderC r m a #
Functor m => Functor (ReaderC r m) Source #
Instance details Defined in Control.Effect.Reader Methods fmap :: (a -> b) -> ReaderC r m a -> ReaderC r m b # (<$) :: a -> ReaderC r m b -> ReaderC r m a #
MonadFix m => MonadFix (ReaderC s m) Source #
Instance details Defined in Control.Effect.Reader Methods mfix :: (a -> ReaderC s m a) -> ReaderC s m a #
MonadFail m => MonadFail (ReaderC r m) Source #
Instance details Defined in Control.Effect.Reader Methods fail :: String -> ReaderC r m a #
Applicative m => Applicative (ReaderC r m) Source #
Instance details Defined in Control.Effect.Reader Methods pure :: a -> ReaderC r m a # (<>) :: ReaderC r m (a -> b) -> ReaderC r m a -> ReaderC r m b # liftA2 :: (a -> b -> c) -> ReaderC r m a -> ReaderC r m b -> ReaderC r m c # (>) :: ReaderC r m a -> ReaderC r m b -> ReaderC r m b # (<*) :: ReaderC r m a -> ReaderC r m b -> ReaderC r m a #
MonadIO m => MonadIO (ReaderC r m) Source #
Instance details Defined in Control.Effect.Reader Methods liftIO :: IO a -> ReaderC r m a #
Alternative m => Alternative (ReaderC r m) Source #
Instance details Defined in Control.Effect.Reader Methods empty :: ReaderC r m a # (<\|>) :: ReaderC r m a -> ReaderC r m a -> ReaderC r m a # some :: ReaderC r m a -> ReaderC r m [a] # many :: ReaderC r m a -> ReaderC r m [a] #
(Alternative m, Monad m) => MonadPlus (ReaderC r m) Source #
Instance details Defined in Control.Effect.Reader Methods mzero :: ReaderC r m a # mplus :: ReaderC r m a -> ReaderC r m a -> ReaderC r m a #
MonadUnliftIO m => MonadUnliftIO (ReaderC r m) Source #
Instance details Defined in Control.Effect.Reader Methods askUnliftIO :: ReaderC r m (UnliftIO (ReaderC r m)) withRunInIO :: ((forall a. ReaderC r m a -> IO a) -> IO b) -> ReaderC r m b
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) a -> ReaderC r m a Source #

Re-exports

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

Instances

Instances details

Carrier Pure PureC Source #
Instance details Defined in Control.Effect.Carrier Methods eff :: Pure PureC a -> PureC a Source #
(HFunctor eff, Carrier sig m, Member eff sig) => Carrier sig (InterposeC eff m) Source #
Instance details Defined in Control.Effect.Interpose Methods eff :: sig (InterposeC eff m) a -> InterposeC eff m a Source #
Monad m => Carrier (Lift m) (LiftC m) Source #
Instance details Defined in Control.Effect.Lift Methods eff :: Lift m (LiftC m) 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) 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) 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) 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) 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) 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) 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) 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) 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) 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) a -> TraceByPrintingC m a Source #
(HFunctor eff, Carrier sig m) => Carrier (eff :+: sig) (InterpretC eff m) Source #
Instance details Defined in Control.Effect.Interpret Methods eff :: (eff :+: sig) (InterpretC eff m) a -> InterpretC eff 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) 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) 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) 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) 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) 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) 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) 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) a -> WriterC w m a Source #
(HFunctor eff, Carrier sig m, Effect sig) => Carrier (eff :+: sig) (InterpretStateC eff s m) Source #
Instance details Defined in Control.Effect.Interpret Methods eff :: (eff :+: sig) (InterpretStateC eff s m) a -> InterpretStateC eff s m a Source #

class Member (sub :: (* -> *) -> * -> *) sup Source #

Minimal complete definition

inj, prj

Instances

Instances details

Member sub sub Source #
Instance details Defined in Control.Effect.Sum Methods inj :: forall (m :: Type -> Type) a. sub m a -> sub m a Source # prj :: forall (m :: Type -> Type) a. sub m a -> Maybe (sub m a) Source #
Member sub sup => Member sub (sub' :+: sup) Source #
Instance details Defined in Control.Effect.Sum Methods inj :: forall (m :: Type -> Type) a. sub m a -> (sub' :+: sup) m a Source # prj :: forall (m :: Type -> Type) a. (sub' :+: sup) m a -> Maybe (sub m a) Source #
Member sub (sub :+: sup) Source #
Instance details Defined in Control.Effect.Sum Methods inj :: forall (m :: Type -> Type) a. sub m a -> (sub :+: sup) m a Source # prj :: forall (m :: Type -> Type) a. (sub :+: sup) m a -> Maybe (sub m a) Source #

run :: PureC a -> a Source #

Run an action exhausted of effects to produce its final result value.