On Tue, Sep 15, 2009 at 11:31 PM, Daniel Fischer <daniel.is.fisc...@web.de> wrote: > ... > Yeah, you do *not* want the whole file to be read here, except above for > testing purposes.
That's not true. Sometimes I want to, sometimes don't. But I want to use the same code for reading files and exploit laziness to avoid reading the body. > Still, ByteStrings are probably the better choice (if you want the body and > that can be > large). That's not a problem by now. > To avoid reading the body without unsafePerformIO: > > readBit fn > = Control.Exception.bracket (openFile fn ReadMode) hClose > (\h -> do > l <- hGetLine h > let i = read l > bdy <- hGetContents h > return $ Bit i bdy) Same problem with the "withFile"-version: nothing gets printed if I try to print out the body: that's way I used seq. I'm starting to think that the only way to do this without using unsafePerformIO is to have the body being an IO action: simply, under Haskell assumption, that's not possible to write, because Haskell enforce safety above all. Cristiano _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
