Effect.AVar

data AVar :: Type -> Type

type AVarCallback a = Either Error a -> Effect Unit

data AVarStatus a

Constructors

• Killed Error
• Filled a
• Empty

new :: forall a. a -> Effect (AVar a)

Creates a fresh AVar with an initial value.

empty :: forall a. Effect (AVar a)

Creates a new empty AVar.

take :: forall a. AVar a -> AVarCallback a -> Effect (Effect Unit)

Takes the AVar value, leaving it empty. If the AVar is already empty, the callback will be queued until the AVar is filled. Multiple takes will resolve in order as the AVar fills. Returns an effect which will remove the callback from the pending queue.

tryTake :: forall a. AVar a -> Effect (Maybe a)

Attempts to synchronously take an AVar value, leaving it empty. If the AVar is empty, this will return Nothing.

put :: forall a. a -> AVar a -> AVarCallback Unit -> Effect (Effect Unit)

Sets the value of the AVar. If the AVar is already filled, it will be queued until the value is emptied. Multiple puts will resolve in order as the AVar becomes available. Returns an effect which will remove the callback from the pending queue.

tryPut :: forall a. a -> AVar a -> Effect Boolean

Attempts to synchronously fill an AVar. If the AVar is already filled, this will do nothing. Returns true or false depending on if it succeeded.

read :: forall a. AVar a -> AVarCallback a -> Effect (Effect Unit)

Reads the AVar value. Unlike take, this will not leave the AVar empty. If the AVar is empty, this will queue until it is filled. Multiple reads will resolve at the same time, as soon as possible.

tryRead :: forall a. AVar a -> Effect (Maybe a)

Attempts to synchronously read an AVar. If the AVar is empty, this will return Nothing.

kill :: forall a. Error -> AVar a -> Effect Unit

Kills the AVar with an exception. All pending and future actions will resolve immediately with the provided exception.

status :: forall a. AVar a -> Effect (AVarStatus a)

Synchronously checks the status of an AVar.

isEmpty :: forall a. AVarStatus a -> Boolean

isFilled :: forall a. AVarStatus a -> Boolean

isKilled :: forall a. AVarStatus a -> Boolean