[Haskell-cafe] Newbie question

[Lemmih]

On 8/12/05, David Roundy <droundy at darcs.net> wrote:
> On Fri, Aug 12, 2005 at 09:17:32AM -0300, Andr Vargas Abs da Cruz wrote:
> > readDataFromFile filename = do
> >    bracket (openFile filename ReadMode) hClose
> >            (\h -> do contents <- hGetContents h
> >                      return (lines contents))
> >
> >    The question is: if i try to run this, it returns me nothing (just
> > an empty list). Why does this happen ? When i remove the "return" and
> > put a "print" instead, it prints everything as i expected.
> 
> I think that this may be because hGetContents puts the file in a
> semi-closed state (and reads the contents lazily).  Try removing the hClose
> (replacing it with (return ()).  Lazy IO is nice, but gets tricky at
> times.

Or better yet, use 'readFile'.

-- 
Friendly,
  Lemmih