Pantry.Internal.Companion

Description

Companion threads, such as for printing messages saying we're still busy. Ultimately this could be put into its own package. This is a non-standard API for use by Pantry and Stack, please /DO NOT DEPEND ON IT/.

Synopsis

# Documentation

withCompanion :: forall m a. MonadUnliftIO m => Companion m -> (StopCompanion m -> m a) -> m a Source #

Keep running the Companion action until either the inner action completes or calls the StopCompanion action. This can be used to give the user status information while running a long running operations.

Arguments

 :: MonadUnliftIO m => m () the delay -> m () action to perform -> m ()

When a delay was interrupted because we're told to stop, perform this action.

type Companion m = Delay -> m () Source #

A companion thread which can perform arbitrary actions as well as delay

type Delay = forall mio. MonadIO mio => Int -> mio () Source #

Delay the given number of microseconds. If StopCompanion is triggered before the timer completes, a CompanionDone exception will be thrown (which is caught internally by withCompanion).

type StopCompanion m = m () Source #

Tell the Companion to stop. The next time Delay is called, or if a Delay is currently blocking, the Companion thread will exit with a CompanionDone exception.