Word jumbler

Name.hs

module Main where

import System.Random
import System.Environment
import Control.Monad
import Data.Array.IO

main :: IO ()
main = do
  [name, num] <- getArgs
  mapM shuffle (replicate (read num) name) >>= putStrLn . unlines
  where
    -- stolen from: https://wiki.haskell.org/Random_shuffle
    shuffle :: [a] -> IO [a]
    shuffle xs = do
        ar <- newArray n xs
        forM [1..n] $ \i -> do
            j <- randomRIO (i,n)
            vi <- readArray ar i
            vj <- readArray ar j
            writeArray ar j vi
            return vj
          where
            n = length xs
            newArray :: Int -> [a] -> IO (IOArray Int a)
            newArray n xs =  newListArray (1,n) xs