Xlsx example for Jyrki

{-# LANGUAGE OverloadedStrings #-} 
import Data.ByteString.Lazy as L hiding (putStrLn)
import Codec.Xlsx
import Control.Lens
import Data.Time.Clock.POSIX (getPOSIXTime)

main = do
  bs <- L.readFile "test.xlsx"
  let
    xlsx0 = toXlsx bs
    value = xlsx0 ^? ixSheet "4_pooli" . ixCell (2,2) . cellValue . _Just
  ct <- getPOSIXTime
  putStrLn $ "Cell B2 contains " ++ show value
  let
    xlsx = xlsx0 & atSheet "sheet" . _Just . cellValueAt (2,2) ?~ CellText "New text"
  L.writeFile "example.xlsx" $ fromXlsx ct xlsx