ask

module Main where

import System.Environment
import System.IO (hFlush, stdout)

ask :: (Show a, Read b) => a -> IO b
ask question = do
     putStr $ show question
     hFlush stdout
     answer <- getLine
     read answer

main :: IO ()
main = do
    name <- ask "What's your name, stranger? "
    print $ "Welcome home, " ++ name

    Could not deduce (Read (IO b)) arising from a use of ‘read’
    from the context (Show a, Read b)
      bound by the type signature for
                 ask :: (Show a, Read b) => a -> IO b
      at listing.hs:6:8-36
    In a stmt of a 'do' block: read answer
    In the expression:
      do { putStr $ show question;
           hFlush stdout;
           answer <- getLine;
           read answer }
    In an equation for ‘ask’:
        ask question
          = do { putStr $ show question;
                 hFlush stdout;
                 answer <- getLine;
                 .... }