gol.hs

module Main where

main :: IO ()
main =
  showcells glider


cls :: IO ()
cls =
  putStr "\ESC[2J]"

type Pos = (Int,Int)

writeat :: Pos -> String -> IO ()
writeat p xs = do goto p
                  putStr xs

goto :: Pos -> IO ()
goto (x,y) =
  putStr ("\ESC[" ++ show y ++ ";" ++ show x ++ "H")

width :: Int
width = 10

height :: Int
height = 10

type Board = [Pos]

glider :: [Pos]
glider = [(4,2),(2,3),(4,3),(3,4),(4,4)]

showcells :: Board -> IO ()
showcells b = sequence_ [writeat p "0" | p <- b]

isAlive :: Board -> Pos -> Bool
isAlive b p = elem p b

isEmpty :: Board -> Pos -> Bool
isEmpty b p = not (isAlive b p)

neighbs :: Pos -> [Pos]
neighbs (x,y) = map wrap [(x-1,y-1), (x,y-1),
                          (x+1,y-1), (x-1,y),
                          (x+1,y), (x-1,1),
                          (x,y+1), (x+1,y+1)]

wrap :: Pos -> Pos
wrap (x,y) = (((x-1) `mod` width) + 1,
              ((y-1) `mod` height) + 1)

liveneighs :: Board -> Pos -> Int
liveneighs b = length . filter (isAlive b) . neighbs