Control.Alarm

Manage an alarm clock running in a dedicated thread.

You specify an amount of time. The alarm clock waits for that amount of time, and then throws an exception back to you, to notify you the time has passed. You can stop and restart it at any time.

This is simply a convenient wrapper over Control.Timer, offered here becuase a common use of timers is to run actions with a time limit (timeout), and the API here makes it more straight-forward to do.

Types

data Alarm

data AlarmWake

Instances

Show AlarmWake

Exception AlarmWake

Creating and destroying alarm

newAlarm :: (TimeUnit t, MonadIO m) => t -> m Alarm

releaseAlarm :: MonadIO m => Alarm -> m ()

withAlarm :: (TimeUnit t, MonadIO m, MonadMask m) => t -> (Alarm -> m a) -> m a

Starting an alarm

startAlarm :: MonadIO m => Alarm -> m ()

startAlarm' :: (TimeUnit t, MonadIO m) => Alarm -> t -> m ()

Stopping a alarm

stopAlarm :: MonadIO m => Alarm -> m ()

Restarting a alarm

restartAlarm :: MonadIO m => Alarm -> m ()

restartAlarm' :: (TimeUnit t, MonadIO m) => Alarm -> t -> m ()

Higher level functions

alarm :: (MonadIO m, MonadCatch m) => Alarm -> m a -> m (Maybe a)

alarm' :: (TimeUnit t, MonadIO m, MonadCatch m) => Alarm -> t -> m a -> m (Maybe a)