[xmonad] CycleWS.toggleWS bug?

[Adam Vogt]

* On Wednesday, September 16 2009, Brent Yorgey wrote:

>Yikes!  If you can make xmonad crash, it is a bug.  Why are
>managehooks different?  How can we prevent bogus managehooks from
>crashing xmonad?
>
>-Brent

in XMonad.Operations (line 71) we have the following:

] manage :: Window -> X ()
]     ...
]     g <- fmap appEndo $ userCodeDef (Endo id) (runQuery mh w)
]     windows (g . f)

It looks like we are catching whether a function is undefined, not
whether the function could be undefined for some input.

I'm not sure about it, but I think laziness (without involving partially
applied functions) can hide exceptions too.

Anybody have ideas where to put the catch in manage in such a way that
the effects of f still happen, without much copy-paste of the windows
function? (or can the effects of f just be left to not happen?)

--
Adam