Safe Haskell	None
Language	Haskell2010

Bluefin.Capability.Modify

Contents

Synopsis

type Modify = State
evalModify :: forall s (es :: Effects) a. s -> (forall (e :: Effects). Modify s e -> Eff (e :& es) a) -> Eff es a
runModify :: forall s (es :: Effects) a. s -> (forall (e :: Effects). Modify s e -> Eff (e :& es) a) -> Eff es (a, s)
withModify :: forall s (es :: Effects) a. s -> (forall (e :: Effects). Modify s e -> Eff (e :& es) (s -> a)) -> Eff es a
get :: forall (e :: Effects) (es :: Effects) s. e <: es => State s e -> Eff es s
put :: forall (e :: Effects) (es :: Effects) s. e <: es => State s e -> s -> Eff es ()
modify :: forall (e :: Effects) (es :: Effects) s. e <: es => State s e -> (s -> s) -> Eff es ()

Capability

Capability to modify a reference to an s

Handlers

Arguments

:: forall s (es :: Effects) a. s	Initial value of modifyable state
-> (forall (e :: Effects). Modify s e -> Eff (e :& es) a)	Stateful computation
-> Eff es a	Result

>>> runPureEff $ evalModify 10 $ \st -> do
      n <- get st
      pure (2 * n)
20

Arguments

:: forall s (es :: Effects) a. s	Initial value of modifyable state
-> (forall (e :: Effects). Modify s e -> Eff (e :& es) a)	Stateful computation
-> Eff es (a, s)	Result and final state

>>> runPureEff $ runModify 10 $ \st -> do
      n <- get st
      pure (2 * n)
(20,10)

Arguments

:: forall s (es :: Effects) a. s	Initial value of modifyable state
-> (forall (e :: Effects). Modify s e -> Eff (e :& es) (s -> a))	Stateful computation
-> Eff es a	Result

>>> runPureEff $ withModify 10 $ \st -> do
      n <- get st
      pure (s -> (2 * n, s))
(20,10)

Arguments

:: forall (e :: Effects) (es :: Effects) s. e <: es
=> State s e
-> Eff es s	The current value of the state

>>> runPureEff $ runState 10 $ \st -> do
      n <- get st
      pure (2 * n)
(20,10)

Arguments

:: forall (e :: Effects) (es :: Effects) s. e <: es
=> State s e
-> s	The new value of the state. The new value is forced before writing it to the state.
-> Eff es ()

Set the value of the state

>>> runPureEff $ runState 10 $ \st -> do
      put st 30
((), 30)

Arguments

:: forall (e :: Effects) (es :: Effects) s. e <: es
=> State s e
-> (s -> s)	Apply this function to the state. The new value of the state is forced before writing it to the state.
-> Eff es ()

>>> runPureEff $ runState 10 $ \st -> do
      modify st (* 2)
((), 20)