Safe Haskell | None |
---|---|
Language | Haskell98 |
- type MonadFail m = MonadError () m
- die :: MonadFail m => m a
- runFailT :: Monad m => ExceptT () m a -> m (Maybe a)
- liftMaybe :: MonadFail m => Maybe a -> m a
- liftEither :: MonadError e m => Either e a -> m a
- failWith :: MonadError e m => Maybe a -> e -> m a
- (<!>) :: MonadError e m => m (Maybe a) -> e -> m a
Documentation
type MonadFail m = MonadError () m
MonadError
with trivial error.
throwError
for MonadFail
.
liftEither :: MonadError e m => Either e a -> m a
Lift an Either
value into a MonadError
computation
failWith :: MonadError e m => Maybe a -> e -> m a
(<!>) :: MonadError e m => m (Maybe a) -> e -> m a
Monadic and infix version of failWith