draw mandelbrot set as ascii art

mandelbrot.hs

import Data.Complex

maxIter :: Int
maxIter = 127

magnification :: Double
magnification = 10.0

xrange :: [Int]
xrange = [-30..30]
yrange :: [Int]
yrange = [-30..30]

main :: IO ()
main = scrPlot $ mandelIter

mandelIter :: (Double, Double) -> Int
mandelIter (x,y) = toOneChar $ mandelbrot (x :+ y) (0 :+ 0) 0

mandelbrot :: Complex Double -- Coordinate to test
           -> Complex Double -- Iterating Z value
           -> Int -- Current iteration
           -> Int -- Iterations before diverging
mandelbrot c z iter
    | iter > maxIter = 0
    | otherwise = let z' = z^2 + c in
                  if magnitude z' > 2
                  then iter
                  else mandelbrot c z' (iter+1)

toOneChar :: Int -> Int
toOneChar x = if x > 9
                  then 9
                  else x

scrPlot :: ((Double, Double) -> Int) -> IO ()
scrPlot f = mapM_ (\y -> do
                  mapM_ (flip printf y) xs
                  putStrLn "") ys
    where
        xs = map fromIntegral xrange
        ys = map fromIntegral yrange
        printf x y = putStr $ show $
            f (fromIntegral x / magnification,fromIntegral y / magnification)


-- 0000000000000000000000000000000000000000000000000000000000000
-- 0000000000000000000000000000000000000000000000000000000000000
-- 0000000000000000000000000000000000000000000000000000000000000
-- 0000000000000000000000000000000000000000000000000000000000000
-- 0000000000000000000000000000000000000000000000000000000000000
-- 0000000000000000000000000000000000000000000000000000000000000
-- 0000000000000000000000000000000000000000000000000000000000000
-- 0000000000000000000000000000000000000000000000000000000000000
-- 0000000000000000000000000000000000000000000000000000000000000
-- 0000000000000000000000000000000000000000000000000000000000000
-- 0000000000000000000000000000001000000000000000000000000000000
-- 0000000000000000000000001111111111111000000000000000000000000
-- 0000000000000000000000111111111111111110000000000000000000000
-- 0000000000000000000011111111111111111111100000000000000000000
-- 0000000000000000001111111111111111111111111000000000000000000
-- 0000000000000000011111111111111111111111111100000000000000000
-- 0000000000000000111111111111111111111111111110000000000000000
-- 0000000000000001111111122222111111111111111111000000000000000
-- 0000000000000011111222222222222211111111111111100000000000000
-- 0000000000000011122222222333943322111111111111100000000000000
-- 0000000000000111222222223334680332211111111111110000000000000
-- 0000000000000122222222333345897433222111111111110000000000000
-- 0000000000001222222223333457009544322211111111111000000000000
-- 0000000000001222222233346779009855432211111111111000000000000
-- 0000000000012222222334459090000099932221111111111100000000000
-- 0000000000012222234444579000000000642221111111111100000000000
-- 0000000000022223466666690000000000843222111111111100000000000
-- 0000000000023334469999890000000000953222111111111100000000000
-- 0000000000033344579000900000000000943222111111111100000000000
-- 0000000000033556990000000000000000743222111111111100000000000
-- 0000000000000000000000000000000009643222211111111110000000000
-- 0000000000033556990000000000000000743222111111111100000000000
-- 0000000000033344579000900000000000943222111111111100000000000
-- 0000000000023334469999890000000000953222111111111100000000000
-- 0000000000022223466666690000000000843222111111111100000000000
-- 0000000000012222234444579000000000642221111111111100000000000
-- 0000000000012222222334459090000099932221111111111100000000000
-- 0000000000001222222233346779009855432211111111111000000000000
-- 0000000000001222222223333457009544322211111111111000000000000
-- 0000000000000122222222333345897433222111111111110000000000000
-- 0000000000000111222222223334680332211111111111110000000000000
-- 0000000000000011122222222333943322111111111111100000000000000
-- 0000000000000011111222222222222211111111111111100000000000000
-- 0000000000000001111111122222111111111111111111000000000000000
-- 0000000000000000111111111111111111111111111110000000000000000
-- 0000000000000000011111111111111111111111111100000000000000000
-- 0000000000000000001111111111111111111111111000000000000000000
-- 0000000000000000000011111111111111111111100000000000000000000
-- 0000000000000000000000111111111111111110000000000000000000000
-- 0000000000000000000000001111111111111000000000000000000000000
-- 0000000000000000000000000000001000000000000000000000000000000
-- 0000000000000000000000000000000000000000000000000000000000000
-- 0000000000000000000000000000000000000000000000000000000000000
-- 0000000000000000000000000000000000000000000000000000000000000
-- 0000000000000000000000000000000000000000000000000000000000000
-- 0000000000000000000000000000000000000000000000000000000000000
-- 0000000000000000000000000000000000000000000000000000000000000
-- 0000000000000000000000000000000000000000000000000000000000000
-- 0000000000000000000000000000000000000000000000000000000000000
-- 0000000000000000000000000000000000000000000000000000000000000
-- 0000000000000000000000000000000000000000000000000000000000000