Safe Haskell	None
Language	Haskell2010

Control.Effect.State.Internal

Contents

State effect
Re-exports

Synopsis

data State s m k
- = Get (s -> m k)
- | Put s (m k)
get :: (Member (State s) sig, Carrier sig m) => m s
gets :: (Member (State s) sig, Carrier sig m) => (s -> a) -> m a
put :: (Member (State s) sig, Carrier sig m) => s -> m ()
modify :: (Member (State s) sig, Carrier sig m) => (s -> s) -> m ()
modifyLazy :: (Member (State s) sig, Carrier sig m) => (s -> s) -> m ()
class Member (sub :: (* -> *) -> * -> *) sup

State effect

data State s m k Source #

Constructors

Get (s -> m k)
Put s (m k)

Instances

Instances details

Effect (State s) Source #
Instance details Defined in Control.Effect.State.Internal Methods handle :: (Functor f, Monad m) => f () -> (forall x. f (m x) -> n (f x)) -> State s m a -> State s n (f a) Source #
HFunctor (State s) Source #
Instance details Defined in Control.Effect.State.Internal Methods fmap' :: forall (f :: Type -> Type) a b. Functor (State s f) => (a -> b) -> State s f a -> State s f b Source # hmap :: Functor m => (forall x. m x -> n x) -> State s m a -> State s n a Source #
Generic1 (State s m :: Type -> Type) Source #
Instance details Defined in Control.Effect.State.Internal Associated Types type Rep1 (State s m) :: k -> Type # Methods from1 :: forall (a :: k). State s m a -> Rep1 (State s m) a # to1 :: forall (a :: k). Rep1 (State s m) a -> State s m a #
Functor m => Functor (State s m) Source #
Instance details Defined in Control.Effect.State.Internal Methods fmap :: (a -> b) -> State s m a -> State s m b # (<$) :: a -> State s m b -> State s m a #
(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 #
type Rep1 (State s m :: Type -> Type) Source #
Instance details Defined in Control.Effect.State.Internal type Rep1 (State s m :: Type -> Type) = D1 ('MetaData "State" "Control.Effect.State.Internal" "fused-effects-0.5.0.1-inplace" 'False) (C1 ('MetaCons "Get" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (((->) s :: Type -> Type) :.: Rec1 m)) :+: C1 ('MetaCons "Put" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 s) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec1 m)))

get :: (Member (State s) sig, Carrier sig m) => m s Source #

Get the current state value.

snd (run (runState a get)) === a

gets :: (Member (State s) sig, Carrier sig m) => (s -> a) -> m a Source #

Project a function out of the current state value.

snd (run (runState a (gets (applyFun f)))) === applyFun f a

put :: (Member (State s) sig, Carrier sig m) => s -> m () Source #

Replace the state value with a new value.

fst (run (runState a (put b))) === b

snd (run (runState a (get <* put b))) === a

snd (run (runState a (put b *> get))) === b

modify :: (Member (State s) sig, Carrier sig m) => (s -> s) -> m () Source #

Replace the state value with the result of applying a function to the current state value. This is strict in the new state.

fst (run (runState a (modify (+1)))) === (1 + a :: Integer)

modifyLazy :: (Member (State s) sig, Carrier sig m) => (s -> s) -> m () Source #

Replace the state value with the result of applying a function to the current state value. This is lazy in the new state; injudicious use of this function may lead to space leaks.

Re-exports

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 #