This module provides solution for parsing and writing Microsoft Open Office XML Workbook format i.e. *.xlsx files

As a simple example you could read cell B3 from the 1st sheet of workbook "report.xlsx" using the following code:

{-# LANGUAGE OverloadedStrings #-}
module Read where
import Codec.Xlsx
import qualified Data.ByteString.Lazy as L
import Control.Lens

main :: IO ()
main = do
  bs <- L.readFile "report.xlsx"
  let value = toXlsx bs ^? ixSheet "List1" .
              ixCell (3,2) . cellValue . _Just
  putStrLn $ "Cell B3 contains " ++ show value

And the following example module shows a way to construct and write xlsx file

{-# LANGUAGE OverloadedStrings #-}
module Write where
import Codec.Xlsx
import Control.Lens
import qualified Data.ByteString.Lazy as L
import Data.Time.Clock.POSIX

main :: IO ()
main = do
  ct <- getPOSIXTime
  let
      sheet = def & cellValueAt (1,2) ?~ CellDouble 42.0
                  & cellValueAt (3,2) ?~ CellText "foo"
      xlsx = def & atSheet "List1" ?~ sheet
  L.writeFile "example.xlsx" $ fromXlsx ct xlsx