ghc/misc/examples/io/io017/Main.hs

   1 main =
   2       hSetBuffering stdout NoBuffering                  >>
   3       putStr   "Enter an integer: "                     >>
   4       readLine                                          >>= \ x1 ->
   5       putStr   "Enter another integer: "                >>
   6       readLine                                          >>= \ x2 ->
   7       putStr  ("Their sum is " ++ show (read x1+ read x2) ++ "\n")
   8
   9  where readLine = isEOF                                 >>= \ eof ->
  10                   if eof then return []
  11                   else getChar                          >>= \ c ->
  12                        if c `elem` ['\n','\r'] then
  13                           return []
  14                        else
  15                           readLine                      >>= \ cs ->
  16                           return (c:cs)
  17