| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Polysemy.AtomicState
Contents
Synopsis
- data AtomicState s m a where
- AtomicState :: (s -> (s, a)) -> AtomicState s m a
- AtomicGet :: AtomicState s m s
- atomicState :: forall s a r. Member (AtomicState s) r => (s -> (s, a)) -> Sem r a
- atomicState' :: forall s a r. Member (AtomicState s) r => (s -> (s, a)) -> Sem r a
- atomicGet :: forall s r. Member (AtomicState s) r => Sem r s
- atomicGets :: forall s s' r. Member (AtomicState s) r => (s -> s') -> Sem r s'
- atomicPut :: Member (AtomicState s) r => s -> Sem r ()
- atomicModify :: Member (AtomicState s) r => (s -> s) -> Sem r ()
- atomicModify' :: Member (AtomicState s) r => (s -> s) -> Sem r ()
- runAtomicStateIORef :: forall s r a. Member (Embed IO) r => IORef s -> Sem (AtomicState s ': r) a -> Sem r a
- runAtomicStateTVar :: Member (Embed IO) r => TVar s -> Sem (AtomicState s ': r) a -> Sem r a
- atomicStateToIO :: forall s r a. Member (Embed IO) r => s -> Sem (AtomicState s ': r) a -> Sem r (s, a)
- atomicStateToState :: Member (State s) r => Sem (AtomicState s ': r) a -> Sem r a
Effect
data AtomicState s m a where Source #
A variant of State that supports atomic operations.
Since: 1.1.0.0
Constructors
| AtomicState :: (s -> (s, a)) -> AtomicState s m a | |
| AtomicGet :: AtomicState s m s |
Instances
| type DefiningModule (AtomicState :: Type -> k -> Type -> Type) Source # | |
Defined in Polysemy.AtomicState | |
Actions
atomicState :: forall s a r. Member (AtomicState s) r => (s -> (s, a)) -> Sem r a Source #
Atomically reads and modifies the state.
atomicState' :: forall s a r. Member (AtomicState s) r => (s -> (s, a)) -> Sem r a Source #
A variant of atomicState in which the computation is strict in the new
state and return value.
atomicGets :: forall s s' r. Member (AtomicState s) r => (s -> s') -> Sem r s' Source #
Since: 1.2.2.0
atomicModify :: Member (AtomicState s) r => (s -> s) -> Sem r () Source #
atomicModify' :: Member (AtomicState s) r => (s -> s) -> Sem r () Source #
A variant of atomicModify in which the computation is strict in the
new state.
Interpretations
runAtomicStateIORef :: forall s r a. Member (Embed IO) r => IORef s -> Sem (AtomicState s ': r) a -> Sem r a Source #
Run an AtomicState effect by transforming it into atomic operations
over an IORef.
runAtomicStateTVar :: Member (Embed IO) r => TVar s -> Sem (AtomicState s ': r) a -> Sem r a Source #
Run an AtomicState effect by transforming it into atomic operations
over a TVar.
atomicStateToIO :: forall s r a. Member (Embed IO) r => s -> Sem (AtomicState s ': r) a -> Sem r (s, a) Source #
Run an AtomicState effect in terms of atomic operations
in IO.
Internally, this simply creates a new IORef, passes it to
runAtomicStateIORef, and then returns the result and the final value
of the IORef.
Beware: As this uses an IORef internally,
all other effects will have local
state semantics in regards to AtomicState effects
interpreted this way.
For example, throw and catch will
never revert atomicModifys, even if runError is used
after atomicStateToIO.
Since: 1.2.0.0
atomicStateToState :: Member (State s) r => Sem (AtomicState s ': r) a -> Sem r a Source #
Transform an AtomicState effect to a State effect, discarding
the notion of atomicity.