gistfile1.hs

import qualified Haste.Graphics.Canvas as C
import qualified Haste as H

indices :: [(Int, Int)]
indices = [(i, j) | i <- [0 .. 2], j <- [0 .. 2]]

strike :: C.Point -> Double -> C.Picture ()
strike (x, y) width =
    let margin = 0.1 * width
        farSide = width - margin
        left = x + margin
        right = x + farSide
        top = y + margin
        bottom = y + farSide
    in C.color (C.RGB 255 0 0) $ do
      C.stroke $ C.line (right, top) (left, bottom)    

draw :: Double -> C.Picture ()                           
draw width =                  
    do
      _ <- sequence $ map drawOne indices    
--      sequence_ $ map drawOne indices    
      strike (20, 20) 80     
    where
      cellWidth = width / 3
      drawOne (x, y) =  
        strike (offset x, offset y) cellWidth                                 
      offset i
        | i == 0 = 0
        | i == 1 = width / 3
        | otherwise = (width * 2) / 3

main :: IO ()
main = do
    Just element <- H.elemById "canvas"
    Just canvas <- C.getCanvas element
    widthString <- H.getProp element "width"
    C.render canvas $ draw (read widthString)