hsdev-0.3.2.1: Haskell development library
Data.Maybe.JustIf
justIf :: a -> Bool -> Maybe a Source #
Return Just if True
Just
whenJust :: Applicative m => Maybe a -> (a -> m b) -> m () Source #
Calls function when value is Just
whenJustM :: Monad m => m (Maybe a) -> (a -> m b) -> m () Source #
Calls function when monad returns Just