Haskell cellular automaton

cellular-automaton.hs

import System.Random

getCell :: Int -> Int -> [Int] -> Int
getCell x y vec = head $ drop ((clamp y) * 32 + (clamp x)) vec
  where clamp i = min 31 (max 0 i)

generation :: Int -> [Int] -> [Int]
generation 0 vec = vec
generation i vec = map step [0 .. length vec]
  where
    vec' = generation (i-1) vec
    step :: Int -> Int
    step i = if (neighSum > 4) then 1 else 0
      where
        x = i `mod` 32
        y = i `div` 32
        neighSum = foldr (+) 0 [getCell (x + x') (y + y') vec' | x' <- [-1..1], y' <- [-1..1], not (x' == 0 && y' == 0) ]

render :: [Int] -> [Char]
render [] = []
render vec = (renderLine $ take 32 vec) ++ ['\n'] ++ (render $ drop 32 vec)
  where
    renderLine :: [Int] -> [Char]
    renderLine (x:xs)
      | x == 0 = [' ', ' '] ++ renderLine xs
      | x == 1 = ['*', ' '] ++ renderLine xs
    renderLine [] = []

main = do
    g <- getStdGen
    let gen0 = (take 1024 (randomRs (0 :: Int, 1 :: Int) g))
    putStr . render $ generation 0 gen0
    putStrLn ['\n', '\n', '\n']
    putStr . render $ generation 1 gen0
    putStrLn ['\n', '\n', '\n']
    putStr . render $ generation 2 gen0
    putStrLn ['\n', '\n', '\n']
    putStr . render $ generation 3 gen0