2008-02-13 IOをつなげる練習 Haskell あたりまえですが、思ったとおりの結果が出力されます。 main = p 2 `and_then` p 3 >> twice (p 6) p :: (Show a) => a -> IO () p n = print n and_then :: IO () -> IO () -> IO () and_then a b = a >> b twice :: IO () -> IO () twice a = a >> a