Data.Textを使った九九の表の出力。

Kuku.hs

module Kuku where

import qualified Data.Text as T
import Data.Text (Text)
import qualified Data.Text.IO as TIO


-- general function
showText :: (Show a) => a -> Text
showText = T.pack . show 
--

kuku :: [[Text]]
kuku = [ map ( formatInt . (x*) ) one2max | x <- one2max ]
  where
    size = 9
    one2max = [1..size] :: [Int]
    formatInt = rjust . showText
    rjust = T.justifyRight digit ' '
    digit = 1 + ( length $ show $ size * size )

kukuf :: Text
kukuf = T.unlines kukuls
  where
    kukuls = map T.concat kuku

main :: IO ()
main = TIO.putStr kukuf