:: Read a => String -> Maybe a package:relude

readMaybe :: Read a => String -> Maybe a
relude Relude.String.Reexport
Parse a string using the Read instance. Succeeds if there is exactly one valid result. 
>>> readMaybe "123" :: Maybe Int
Just 123

>>> readMaybe "hello" :: Maybe Int
Nothing
@since base-4.6.0.0
die :: MonadIO m => String -> m a
relude Relude.Lifted.Exit
Lifted version of die. 
>>> die "Goodbye!"
Goodbye!
*** Exception: ExitFailure 1