On Thu, Oct 18, 2007 at 09:25:32 -0400, David Roundy wrote:
On Thu, Oct 18, 2007 at 01:16:37PM +0100, Magnus Therning wrote:
On Thu, Oct 18, 2007 at 20:58:45 +1000, Matthew Brecknell wrote:
For a less hackish solution, you need to do a bit more work. Again, this is untested.
loadAndCheck fn = bracket (openFile fn ReadMode) hClose checkContents checkContents fh = do { s <- hGetContents fh; return $! hasEmpty s }
Note the explicit close, and "return $!" to ensure that hasEmpty has done its work before the file is closed.
Ah, `bracket` is a handy function to know!
Note that you almost never want to use the bracket defined in Haskell98, nor the one in IO.Error. You want the bracket defined in Control.Exception.
Yes, thankfully that's documented in the Haddock for the only one that turns up on Hoogle. /M -- Magnus Therning (OpenPGP: 0xAB4DFBA4) magnus＠therning．org Jabber: magnus．therning＠gmail．com http://therning.org/magnus