ref: a4f5892f3b4aa79446f85e4b60f01564a1f18a9c
dir: /lib/Control/Monad/Fail.hs/
module Control.Monad.Fail(MonadFail(..)) where import Prelude() -- do not import Prelude 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 _ = []