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

   1 import IO -- 1.3
   2
   3 main =
   4       hSetBuffering stdout NoBuffering                  >>
   5       putStr   "Enter an integer: "                     >>
   6       readLine                                          >>= \ x1 ->
   7       putStr   "Enter another integer: "                >>
   8       readLine                                          >>= \ x2 ->
   9       putStr  ("Their sum is " ++ show (read x1+ read x2) ++ "\n")
  10
  11  where readLine = isEOF                                 >>= \ eof ->
  12                   if eof then return []
  13                   else getChar                          >>= \ c ->
  14                        if c `elem` ['\n','\r'] then
  15                           return []
  16                        else
  17                           readLine                      >>= \ cs ->
  18                           return (c:cs)
  19