Control.Wire.Trans.Fork

Wire concurrency.

Warning: This module is highly experimental and currently causes space leaks. Please use wire concurrency only for short-lived threads.

Embedding concurrent wires

class Arrow >~ => WFork (>~) where

Forking wire transformer. Creates a concurrent wire thread and opens a communication channel to it.

Methods

feedWire :: Wire e >~ (WireChan a b, a) ()

Feed a wire thread with additional input.

• Depends: Current instant.

forkWire :: Wire e >~ (Wire e >~ a b, WireMgr) (WireChan a b, WireThread)

Fork the input wire using the input wire manager.

Note: This wire forks at every instant. In many cases you will want to use the swallow wire transformer with this.

• Depends: Current instant.

queryWire :: Monoid e => Wire e >~ (WireChan a b) b

Asks the given wire for its next output.

• Depends: Current instant.
• Inhibits: When there is no data.

Instances

(MonadBaseControl IO m, MonadIO m) => WFork (Kleisli m)

Wire thread manager

data WireMgr

A wire thread manager keeps track of created wire threads.

startWireMgr :: IO WireMgr

Start a wire manager.

stopWireMgr :: WireMgr -> IO ()

Stop a wire manager terminating all threads it keeps track of.

withWireMgr :: (MonadBaseControl IO m, MonadIO m) => (WireMgr -> m a) -> m a

Convenient wrapper around startWireMgr and stopWireMgr.

Wire threads

Channels

data WireChan a b

A wire channel allows you to send input to and receive output from a concurrently running wire.

feedWireChan :: WireChan a b -> a -> IO ()

Feed the given wire thread with input.

readWireChan :: WireChan a b -> IO b

Read the given wire's next output.

Threads

data WireThread

A wire thread is a concurrently running wire.

killWireThread :: WireMgr -> WireThread -> IO ()

Kill the given wire thread.