Control.Monad.Aff.AVar

makeVar :: forall a eff. a -> Aff (avar :: AVAR | eff) (AVar a)

Creates a fresh AVar with an initial value.

makeEmptyVar :: forall a eff. Aff (avar :: AVAR | eff) (AVar a)

Creates a fresh AVar.

status :: forall a eff. AVar a -> Aff (avar :: AVAR | eff) (AVarStatus a)

Synchronously checks the status of an AVar.

isEmptyVar :: forall a eff. AVar a -> Aff (avar :: AVAR | eff) Boolean

Synchronously checks whether an AVar currently is empty.

isFilledVar :: forall a eff. AVar a -> Aff (avar :: AVAR | eff) Boolean

Synchronously checks whether an AVar currently has a value.

isKilledVar :: forall a eff. AVar a -> Aff (avar :: AVAR | eff) Boolean

Synchronously checks whether an AVar has been killed.

takeVar :: forall a eff. AVar a -> Aff (avar :: AVAR | eff) a

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.

tryTakeVar :: forall a eff. AVar a -> Aff (avar :: AVAR | eff) (Maybe a)

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

putVar :: forall a eff. a -> AVar a -> Aff (avar :: AVAR | eff) 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.

tryPutVar :: forall a eff. a -> AVar a -> Aff (avar :: AVAR | eff) 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.

readVar :: forall a eff. AVar a -> Aff (avar :: AVAR | eff) a

Reads the AVar value. Unlike takeVar, 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.

tryReadVar :: forall a eff. AVar a -> Aff (avar :: AVAR | eff) (Maybe a)

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

killVar :: forall a eff. Error -> AVar a -> Aff (avar :: AVAR | eff) Unit

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

data AVarStatus a

Constructors

• Killed Error
• Filled a
• Empty

data AVar :: Type -> Type

data AVAR :: Effect

isKilled :: forall a. AVarStatus a -> Boolean

isFilled :: forall a. AVarStatus a -> Boolean

isEmpty :: forall a. AVarStatus a -> Boolean