a program that given an input, generates a more complex state from it, using both infromation from IO and known variables.

Build.hs

{-# LANGUAGE NamedFieldPuns #-}
module Build where

import System.IO
import Control.Monad


data State = State {word :: String
                   ,word1 :: String
                   ,word2 :: String
                   ,word3 :: String}
             deriving (Show)
state = State "hi" "one hi" "two hi" "bye"
main :: IO ()
main = forever $ do  
        contents <- readFile "state.txt"
        let one:_ = lines contents
        let two = "cached two"
        _ <- putStr "Input a word: "
        word <- getLine
        let word1 = unwords [one,word]
        let word2 = unwords [two,word]
        print $ state {word,word1,word2}
        
        

state.txt

state one