cellularautomata.hs

next :: [Int] -> [Int]
next [] = []
next (i1:is) = case is of
  []     -> [0]
  i2:_ -> i2:(next' i1 is) where
    next' l [] = [l]
    next' l (i:is) = case is of
       [] -> [i]
       r:_ -> (l `xor` r):(next' i is) where
         xor 0 0 = 0
         xor 1 0 = 1
         xor 0 1 = 1
         xor 1 1 = 0
       
doCA :: Int -> [Int] -> [[Int]]
doCA n s = take n $ scanl doNext s [0..] where
  doNext l _ = next l