FP.API.Signal

A very minimal library for broadcasting events to listeners.

Documentation

data Signal m a

Constructors

Signal (IORef (IntMap (a -> m ())))

newSignal :: IO (Signal m a)

sendSignal :: MonadIO m => Signal m a -> a -> m ()

subscribeSignal :: Signal m a -> (IO () -> a -> m ()) -> IO (IO ())

blockOnSignal :: MonadIO m => Maybe Int -> Signal m a -> (a -> m (Maybe b)) -> IO (Maybe b)

Block, watching for a particular value (indicated by Just). Once a Just value is seen, stop subscribing, and return the value. The Maybe Int argument specifies an optional timeout in microseconds. If the function instead times out, then Nothing is yielded.