Control.MonadFail.Graph

Documentation

class GMonad m => GMonadFail m where

Graph indexed monad with failure.

Associated Types

type Fail m :: p

The unit failure element of the index.

Default instance: Fail m = Unit m

Methods

gfail :: String -> m (Fail m) a

Fail with a message.

Default implementation requires the default instance of Fail.

gfail :: (GMonadZero m, Zero m ~ Fail m) => String -> m (Fail m) a

Fail with a message.

Default implementation requires the default instance of Fail.

Instances

Monad m => GMonadFail * (GWrapped m)

Associated Types

type Fail (GWrapped m) (m :: GWrapped m -> * -> *) :: p

Methods

gfail :: String -> m (Fail (GWrapped m) m) a