import Numeric

left,right    :: (Int,Int) -> (Int,Int)
left  (dx,dy) = (-dy, dx)           -- 左折
right (dx,dy) = (dy, -dx)           -- 右折

f   :: (Int,Int) -> IO ()           -- Fに対応する, rlinetoは相対位置まで線を引く
f   (dx,dy) = putStrLn ((show dx) ++ " " ++ (show dy) ++  " rlineto")

x,y :: Int -> (Int,Int) -> IO ()    -- X,Yに対応
x 0 (_,_) = putStr ""               -- 0次ならなにもしない. 空を出力
x (n+1) (x0,y0) = do y n (x1,y1); f (x1,y1); x n (x0,y0); f (x0,y0)
                     x n (x0,y0); f (x3,y3); y n (x3,y3)
  where (x1,y1) = left (x0,y0); (x3,y3) = right (x0,y0)

y 0 (_,_) = putStr ""
y (n+1) (x0,y0) =do x n (x3,y3); f (x3,y3); y n (x0,y0); f (x0,y0)
                    y n (x0,y0); f (x1,y1); x n (x1,y1)
  where (x1,y1) = left (x0,y0); (x3,y3) = right (x0,y0)

hilbert :: Int -> Int -> IO ()      -- ドライバ
hilbert size n = do putStrLn ((show o) ++ " " ++ (show o) ++  " moveto")
                    x n (x0,y0) 
                    putStrLn "stroke"
      where x0 = size `div` (2 ^ n) -- セグメント長 (= 移動距離)
            y0 = 0
            o  = x0 `div` 2         -- 原点から出発位置までの距離

main = hilbert 256 5