Control.Monad.Resource

register :: forall m. MonadResource m => Aff Unit -> m ReleaseKey

Register some release action to run in the cleanup phase, returning the ReleaseKey for the action.

acquire :: forall m a. MonadResource m => Aff a -> (a -> Aff Unit) -> m (Tuple ReleaseKey a)

Given logic to acquire and free a resource a, this will: acquire the resource, register the release action, and return the resource and the action's ReleaseKey

deregister :: forall m. MonadResource m => ReleaseKey -> m Unit

Remove the release action associated with the key.

release :: forall m. MonadResource m => ReleaseKey -> m Unit

Trigger the release action for the ReleaseKey if it is registered.

release' :: forall m. MonadResource m => ReleaseKey -> m Boolean

Trigger the release action for the ReleaseKey if it is registered. Returns true if the key was found, false otherwise.

isRegistered :: forall m. MonadResource m => ReleaseKey -> m Boolean

Returns true if the given ReleaseKey is registered in the current ResourceT, and false otherwise.

isReleased :: forall m. MonadResource m => ReleaseKey -> m Boolean

Returns true if the given ReleaseKey is not registered in the current ResourceT, and true otherwise.

fork :: forall a m. MonadResource m => Resource a -> m (Fiber a)

forkAff :: forall a m. MonadResource m => Aff a -> m (Fiber a)

supervise :: forall a. Resource a -> Resource a

class (MonadAff m) <= MonadResource m  where

Members

• liftResourceT :: forall a. ResourceT Aff a -> m a

Instances

• (MonadAff m) => MonadResource (ResourceT m)
• (MonadResource m) => MonadResource (ContT r m)
• (MonadResource m) => MonadResource (ExceptT e m)
• (MonadResource m) => MonadResource (ListT m)
• (MonadResource m) => MonadResource (MaybeT m)
• (MonadResource m) => MonadResource (ReaderT r m)
• (MonadResource m, Monoid w) => MonadResource (RWST r w s m)
• (MonadResource m) => MonadResource (StateT s m)
• (MonadResource m, Monoid w) => MonadResource (WriterT w m)

newtype ReleaseKey

Instances

• Eq ReleaseKey
• Ord ReleaseKey

newtype ResourceT (m :: Type -> Type) a

The resource cleanup monad transformer.

This monad transformer extends the base monad with a mutable registry for tracking resource cleanup actions. At the end of evaluation all remaining cleanup actions are executed.

Instances

• (Functor m) => Functor (ResourceT m)
• (Apply m) => Apply (ResourceT m)
• (Applicative m) => Applicative (ResourceT m)
• (Bind m) => Bind (ResourceT m)
• (Monad m) => Monad (ResourceT m)
• MonadTrans ResourceT
• (MonadAsk r m) => MonadAsk r (ResourceT m)
• (MonadReader r m) => MonadReader r (ResourceT m)
• (MonadTell w m) => MonadTell w (ResourceT m)
• (MonadWriter w m) => MonadWriter w (ResourceT m)
• (MonadState s m) => MonadState s (ResourceT m)
• (MonadCont m) => MonadCont (ResourceT m)
• (MonadThrow e m) => MonadThrow e (ResourceT m)
• (MonadError e m) => MonadError e (ResourceT m)
• (MonadEffect m) => MonadEffect (ResourceT m)
• (MonadAff m) => MonadAff (ResourceT m)
• (MonadRec m) => MonadRec (ResourceT m)
• (Monad m, Alt m) => Alt (ResourceT m)
• (Monad m, Plus m) => Plus (ResourceT m)
• (Monad m, Alternative m) => Alternative (ResourceT m)
• (MonadPlus m) => MonadPlus (ResourceT m)
• (Parallel f m) => Parallel (ResourceT f) (ResourceT m)

type Resource = ResourceT Aff

The Resource monad is a synonym for ResourceT Aff.

runResourceT :: forall m a b. (m a -> Aff b) -> ResourceT m a -> Aff b

Run a computation in the ResourceT monad, while changing it to Aff to ensure the cleanup will run safely.

runResource :: forall a. Resource a -> Aff a

Run an Aff computation in the ResourceT monad.

mapResourceT :: forall m m' a b. (m a -> m' b) -> ResourceT m a -> ResourceT m' b

Change the type of the result in a ResourceT monad action.