[Xmonad] patch: StackSet.hs edits

[Don Stewart]

byorgey:
>    Hi all,
> 
>    I've begun going through the xmonad code carefully, in order to understand
>    how it works, be able to contribute more, etc.  Today I went through
>    StackSet.hs.  While I was going through I made a bunch of small changes
>    (mostly documentation changes).  The only code changes I made were (1)
>    changing a gratuitous 'return' to 'Just'; (2) renaming 'findIndex' to
>    'findTag'.  The second may be controversial; I don't know what the policy
>    is on changing the names of functions exported by the core, but to me
>    'findTag' says *much* more clearly what the function does. 

The rule is you have to update the QuickCheck properties for that
function, and any XMC modules that break in the process. As a result,
we're fairly wary of changing names needlessly, and it also breaks some
Config.hs files. So hard to say, as findTag is a better name.

>    I have also attached a patch for XMonadContrib which changes findIndex to
>    findTag in the only contrib module which uses it, Dzen.hs.  Obviously this
>    patch should only be applied if the corresponding patch for core is made.

Good. How often is it used in Config.hs files, do you think?

-- Don