Потоки и матрицы

import System.Environment
import System.IO
 
main = do
    putStrLn "Input name file"
    (fileName: _) <- getArgs
    contents <- readFile fileName
    listMax <- writeMaxDigit (lines contents) []
    putStrLn maximum $ listMax
 
writeMaxDigit :: [[Char]] -> [Int] -> [Int]
--writeMaxDigit [[]] _ = 0
writeMaxDigit (x:xs) n = writeMaxDigit xs (maximum wordList : n)
    where wordList = map(read :: String -> Int).words $ x

import Control.Parallel.Strategies( using, parList, rdeepseq )
import System.Environment
-- import System.IO
 
main :: IO ()
main = do
    putStrLn "Input name file"
    (fileName: _) <- getArgs 
    contents <- readFile fileName 
    let listMax = writeMaxDigit $ filter (/="") $ lines contents
    print $ maximum listMax
 
writeMaxDigit :: [[Char]] -> [Int]
writeMaxDigit xs = map (maximum . wordList) xs 
                    `using` parList rdeepseq
    where wordList = map (read) . words

executable tstPar
  ghc-options:         -Wall -threaded
  hs-source-dirs:      src
  main-is:             Main.hs
  default-language:    Haskell2010
  build-depends:       base >= 4.7 && < 5
                      ,parallel

import Control.Parallel.Strategies( using, parList, rdeepseq )
import System.Environment
import Data.Time
 
main :: IO ()
main = do
    (fileName: _) <- getArgs 
    contents <- readFile fileName 
    begT <- getCurrentTime
    let listMax = writeMaxDigit $ filter (/="") $ lines contents
    print $ maximum listMax
    endT <- getCurrentTime
    putStr "diffTime="
    print $ diffUTCTime endT begT