mkC1PMatrix.hs

import System.Random.Shuffle
import System.Random
import System.Environment
import Data.List

main :: IO ()
main =
  getArgs >>=
  \args -> if 3 /= (length args)
           then putStrLn "Usage: $ ./mkC1Pmatrix 100 32 randomC1Pmatrix"
           else
             mkC1PMatrix (read $ head args) (read $ head $ tail args) >>=
             \m  -> shuffleM (transpose m) >>=
             \m' -> writeFile (last args) (unlines $ transpose m')

mkC1PMatrix :: Int -> Int -> IO [String]
mkC1PMatrix 0 _ = return []
mkC1PMatrix m n = mkC1PRow n >>= \r -> mkC1PMatrix (m-1) n >>= \rs -> return (r : rs)

mkC1PRow :: Int -> IO String
mkC1PRow w =
  (randomRIO (1, w) :: IO Int) >>= \l -> -- l is the length of run
  (randomRIO (0, w-l) :: IO Int) >>= \s -> -- s is the starting point of run
  getStdGen >>= \gen ->
  let r = take l $ repeat '1' in
  return $ (take s $ repeat '0') ++ r ++ (take (w-s-l) $ repeat '0')

mkC1PRuleList :: Int -> Int -> IO [String]
mkC1PRuleList 0 _ = return []
mkC1PRuleList n w = mkC1PRule w >>= \r -> mkC1PRuleList (n-1) w >>= \rs -> return (r : rs)

mkC1PRule :: Int -> IO String
mkC1PRule w =
  (randomRIO (1, w) :: IO Int) >>= \l -> -- l is the length of run
  (randomRIO (0, w-l) :: IO Int) >>= \s -> -- s is the starting point of run
  getStdGen >>= \gen ->
  let r = take l $ (randomRs ('0','1') gen) :: [Char] in
  return $ (take s $ repeat '*') ++ r ++ (take (w-s-l) $ repeat '*')