import Control.Monad
import Control.Applicative


safeDiv :: (Monad m, Alternative m) => Int -> Int -> m Int
safeDiv x y = do
  guard (y /= 0)
  pure (x `div` y)

main :: IO ()
main = do
  print $ safeDiv @Maybe 1 0
  print $ safeDiv @[] 1 0
  -- print =<< safeDiv @IO 1 0 -- guard throws an error in IO