import Printf import Control.Exception ( evaluate ) main = do fn <- evaluate $! printf "%10.4f\n" fn $> (10.0 :: Double) ! [] fn $> (-10.0 :: Double) ! [] fn $> (10.1010 :: Double) ! [] fn $> (0.0 :: Double) ! [] fn $> (0.987654321 :: Double) ! [] fn $> (987654321 :: Double) ! [] fn $> (-987654321 :: Double) ! []