cairo drawing lib bits with combinators

gistfile1.hs

  -- cairo drawing lib bits with combinators

  moveToP = uncurry moveTo
  lineToP = uncurry lineTo
  curveToP ((x1,y1),(x2,y2),(x3,y3)) = curveTo x1 y1 x2 y2 x3 y3

  doWith g f x = do { f x; g }
  withDo f g x = do { f; g x }

  listDo _ _ [] = return ()
  listDo f g (x:xs) = do { f x; g xs }
  tupleDo f g (x,y) = do { f x; g y }

  fillWith = doWith fill
  strokeWith = doWith stroke
  closePathWith = doWith closePath

  fillPolygon = fillWith drawPolygon

  strokePolygon = strokeWith drawPolygon
  strokeOpenPolygon = strokeWith drawOpenPolygon

  drawPolygon = closePathWith drawOpenPolygon
  drawOpenPolygon = withDo newPath drawSubPolygon
  drawSubPolygon = listDo moveToP addToPolygon
  addToPolygon = mapM_ lineToP

  fillPath = fillWith drawPath
  strokePath = strokeWith drawPath
  strokeOpenPath = strokeWith drawOpenPath

  drawPath = closePathWith drawOpenPath
  drawOpenPath = withDo newPath drawSubPath
  drawSubPath = tupleDo moveToP addToPath
  addToPath = mapM_ curveToP