Control.Concurrent.EQueue

Documentation

class EQueue eq where

An EQueue is a way of managing edge and level triggered events. The choice of EQueue implementation allows late binding of the policy by which the application processes events.

Methods

registerSemi :: (MonadIO m, Semigroup b) => eq a -> (b -> a) -> m (b -> IO (), IO ())

Registers a level triggered event. These are the events that accumulate a combined change or resulting state. Returns a function to enqueue updates and unregister this event.

registerQueued :: MonadIO m => eq a -> m (a -> IO (), IO ())

Registers an edge triggered event. Returns a function to enqueue updates and unregister this event.

Instances

EQueue STMEQueue

Defined in Control.Concurrent.EQueue.STMEQueue

Methods

registerSemi :: (MonadIO m, Semigroup b) => STMEQueue a -> (b -> a) -> m (b -> IO (), IO ())

registerQueued :: MonadIO m => STMEQueue a -> m (a -> IO (), IO ())

EQueue ForceEdge

Defined in Control.Concurrent.EQueue

Methods

registerSemi :: (MonadIO m, Semigroup b) => ForceEdge a -> (b -> a) -> m (b -> IO (), IO ())

registerQueued :: MonadIO m => ForceEdge a -> m (a -> IO (), IO ())

EQueue AnyEQueue

Defined in Control.Concurrent.EQueue

Methods

registerSemi :: (MonadIO m, Semigroup b) => AnyEQueue a -> (b -> a) -> m (b -> IO (), IO ())

registerQueued :: MonadIO m => AnyEQueue a -> m (a -> IO (), IO ())

EQueue IOEQueue

Defined in Control.Concurrent.EQueue.Simple

Methods

registerSemi :: (MonadIO m, Semigroup b) => IOEQueue a -> (b -> a) -> m (b -> IO (), IO ())

registerQueued :: MonadIO m => IOEQueue a -> m (a -> IO (), IO ())

EQueue TQueueEQueue

Can not unregister events

Defined in Control.Concurrent.EQueue.Simple

Methods

registerSemi :: (MonadIO m, Semigroup b) => TQueueEQueue a -> (b -> a) -> m (b -> IO (), IO ())

registerQueued :: MonadIO m => TQueueEQueue a -> m (a -> IO (), IO ())

EQueue TChanEQueue

Can not unregister events

Defined in Control.Concurrent.EQueue.Simple

Methods

registerSemi :: (MonadIO m, Semigroup b) => TChanEQueue a -> (b -> a) -> m (b -> IO (), IO ())

registerQueued :: MonadIO m => TChanEQueue a -> m (a -> IO (), IO ())

EQueue ChanEQueue

Can not unregister events

Defined in Control.Concurrent.EQueue.Simple

Methods

registerSemi :: (MonadIO m, Semigroup b) => ChanEQueue a -> (b -> a) -> m (b -> IO (), IO ())

registerQueued :: MonadIO m => ChanEQueue a -> m (a -> IO (), IO ())

EQueue eq => EQueue (MappedEQueue eq b)

Defined in Control.Concurrent.EQueue

Methods

registerSemi :: (MonadIO m, Semigroup b0) => MappedEQueue eq b a -> (b0 -> a) -> m (b0 -> IO (), IO ())

registerQueued :: MonadIO m => MappedEQueue eq b a -> m (a -> IO (), IO ())

class EQueueW eq where

An EQueueW is the interface for waiting on events in a queue.

Methods

waitEQ :: MonadIO m => eq a -> WaitPolicy eq -> m [a]

The dequeue operation, collecting some set of available events, depending on the particular policy the given EQueue impliments.

Instances

EQueueW STMEQueue

Defined in Control.Concurrent.EQueue.STMEQueue

Associated Types

type WaitPolicy STMEQueue :: Type

Methods

waitEQ :: MonadIO m => STMEQueue a -> WaitPolicy STMEQueue -> m [a]

EQueueW TQueueEQueue

Defined in Control.Concurrent.EQueue.Simple

Associated Types

type WaitPolicy TQueueEQueue :: Type

Methods

waitEQ :: MonadIO m => TQueueEQueue a -> WaitPolicy TQueueEQueue -> m [a]

EQueueW TChanEQueue

Defined in Control.Concurrent.EQueue.Simple

Associated Types

type WaitPolicy TChanEQueue :: Type

Methods

waitEQ :: MonadIO m => TChanEQueue a -> WaitPolicy TChanEQueue -> m [a]

EQueueW ChanEQueue

Defined in Control.Concurrent.EQueue.Simple

Associated Types

type WaitPolicy ChanEQueue :: Type

Methods

waitEQ :: MonadIO m => ChanEQueue a -> WaitPolicy ChanEQueue -> m [a]

data AnyEQueue a where

Allows us to return an unknown instance of EQueue, getting around Haskells lack of existential qualification.

Constructors

AEQ :: EQueue eq => eq a -> AnyEQueue a

Instances

EQueue AnyEQueue

Defined in Control.Concurrent.EQueue

Methods

registerSemi :: (MonadIO m, Semigroup b) => AnyEQueue a -> (b -> a) -> m (b -> IO (), IO ())

registerQueued :: MonadIO m => AnyEQueue a -> m (a -> IO (), IO ())

data ForceEdge a where

A wrapper that translates level triggered events into events that observe the edges.

Constructors

EEQ :: EQueue eq => eq a -> ForceEdge a

Instances

EQueue ForceEdge

Defined in Control.Concurrent.EQueue

Methods

registerSemi :: (MonadIO m, Semigroup b) => ForceEdge a -> (b -> a) -> m (b -> IO (), IO ())

registerQueued :: MonadIO m => ForceEdge a -> m (a -> IO (), IO ())

data MappedEQueue eq b a where

A wrapper that allows us to pretend a queue of one type is of another.

Constructors

MEQ :: (a -> b) -> eq b -> MappedEQueue eq b a

Instances

Contravariant (MappedEQueue eq b)

Defined in Control.Concurrent.EQueue

Methods

contramap :: (a -> b0) -> MappedEQueue eq b b0 -> MappedEQueue eq b a

(>$) :: b0 -> MappedEQueue eq b b0 -> MappedEQueue eq b a

EQueue eq => EQueue (MappedEQueue eq b)

Defined in Control.Concurrent.EQueue

Methods

registerSemi :: (MonadIO m, Semigroup b0) => MappedEQueue eq b a -> (b0 -> a) -> m (b0 -> IO (), IO ())

registerQueued :: MonadIO m => MappedEQueue eq b a -> m (a -> IO (), IO ())

meqEQ :: MappedEQueue eq b a -> eq b

Retrieve the EQueue we're mapping to from the MappedEQueue.

data STMEQueue a

A basic example implimentation of an EQueue using STM. This implimentation must look at every registered event source leading to inefficiency in systems with a very large number of sources. For most systems it should be a sufficient implimentation though.

Instances

EQueueW STMEQueue

Defined in Control.Concurrent.EQueue.STMEQueue

Associated Types

type WaitPolicy STMEQueue :: Type

Methods

waitEQ :: MonadIO m => STMEQueue a -> WaitPolicy STMEQueue -> m [a]

EQueue STMEQueue

Defined in Control.Concurrent.EQueue.STMEQueue

Methods

registerSemi :: (MonadIO m, Semigroup b) => STMEQueue a -> (b -> a) -> m (b -> IO (), IO ())

registerQueued :: MonadIO m => STMEQueue a -> m (a -> IO (), IO ())

type WaitPolicy STMEQueue

Defined in Control.Concurrent.EQueue.STMEQueue

type WaitPolicy STMEQueue = STMEQueueWait

data STMEQueueWait

The policy for waiting on an STMEQueue.

Constructors

ReturnImmediate

Immediately return, even if no events are available.

RequireEvent

Wait for at least one event to be available before returning.

Instances

Eq STMEQueueWait

Defined in Control.Concurrent.EQueue.STMEQueue

Methods

(==) :: STMEQueueWait -> STMEQueueWait -> Bool

(/=) :: STMEQueueWait -> STMEQueueWait -> Bool

newSTMEQueue :: MonadIO m => m (STMEQueue a)

Create a new STMEQueue which initally has no event sources registered.