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)
- | 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)
Local (r -> r) (m b) (b -> m k)

Instances

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' :: 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

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 # fail :: String -> 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

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

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