[Xmonad] darcs patch: use a global IORef to keep list of urgent windows

[David Roundy]

On Tue, Oct 30, 2007 at 08:25:14AM -0700, Don Stewart wrote:
> me:
> > On Mon, Oct 29, 2007 at 10:08:32PM -0700, Don Stewart wrote:
> > > me:
> > > > Any other reason this isn't applied?
> > > You expressed hesitation? :)
> > Point. ;) Well, for the record, consider me un-hesitating. I'd still
> > like input on those restart bugs, but they're orthogonal to the patch.
> 
> Oh, that's an issue -- now you've hidden state away in a module, how are
> we going to get at it to serialise? This is why global state is bad.
> 
> If the state was threaded through lambdabot, again, we'd be able to
> flush it out when restarting.
> 
> So now I'm more hesitant about encouraing refs for state -- its
> inherently going to break serialisation/restart persistence.

There is certainly state that shouldn't be serialized.  Mightn't the list
of urgent windows fall in this category?
-- 
David Roundy
Department of Physics
Oregon State University