Reader monad example

Module1.hs

module Module1 where

import Control.Monad.Reader

data Config = Config { arg :: Int }

initialize :: IO Config
initialize = do
    n <- getLine
    return $ Config (read n)

function1 :: Reader Config Int
function1 = do
    conf <- ask
    return (arg conf + 1)

function2 :: Reader Config Int
function2 = do
    conf <- ask
    return (arg conf + 2)

Module2.hs

module Module2 where

import Module1
import Control.Monad.Reader

main = do
    conf <- initialize
    let n1 = runReader function1 conf
    let n2 = runReader function2 conf
    putStrLn $ "Results: " ++ show (n1,n2)

NB I totally have not type checked any of the above!