stupid io question (haskell)

[juan_gandhi]

We had a discussion recently regarding this kind of code and how it should behave

import System.IO
import Data.Char(toUpper)

main::IO()
main = do
  h ←  openFile "/vladp/haskell/testfile.txt" ReadMode
  input ←  hGetContents h
  hClose h
  let result = map toUpper input
  putStr result

Well, basically, no surprise; the moment the string started being scanned, there's already nothing there, so it does not print anything... somehow we were not sure about it, now I wonder why should we.