ref: b7c1f531cc5f0bf95cbcfae20ef735c015e21f79
dir: /lib/Control/Monad/Fail.hs/
module Control.Monad.Fail(MonadFail(..)) where import Primitives import Control.Applicative import Control.Error import Control.Monad import Data.Char import Data.List_Type class Monad m => MonadFail m where fail :: forall a . String -> m a fail = error instance MonadFail [] where fail _ = []