Control.Monad.Trans.Task

Task monad transformer

newtype TaskT e m a

Task monad transformer.

Constructors

TaskT

Fields

runTaskT :: ContT (Trace m e) m a

Instances

MonadReader s m => MonadReader s (TaskT e m)

MonadState s m => MonadState s (TaskT e m)

Monad m => MonadTask e (TaskT e m)

MonadTrans (TaskT e)

Monad m => Monad (TaskT e m)

Functor (TaskT e m)

Applicative (TaskT e m)

MonadIO m => MonadIO (TaskT e m)

Trace of a base monad

data Trace m e where

A Trace m e represents the control flow of a mult-threaded task monad defined over a base monad m and event type e.

Constructors

EXIT :: Trace m e

RET :: Trace m e

YIELD :: m (Trace m e) -> Trace m e

FORK :: m (Trace m e) -> m (Trace m e) -> Trace m e

WATCH :: (e -> Maybe v) -> (v -> m (Trace m e)) -> Trace m e

SIGNAL :: e -> m (Trace m e) -> Trace m e

runTrace :: Monad m => m (Trace m e) -> m ()

runTrace runs a trace to its completion in the base monad with a simple round-robin scheduler.

Task functions

taskToTrace :: Monad m => TaskT e m a -> m (Trace m e)

tasktoTrace CPS-converts a task monad into a trace in its base monad.

runTask :: Monad m => TaskT e m a -> m ()

runTask runs a task monad until to its completion, i.e., no more active tasks to run, or until it exits.

• runTask = runTrace . taskToTrace