ref: 4ce38e41a9f2f99c2fedf260039839e18bbe1d94
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 _ = []