Re: display-buffer-alist simplifications

[Juri Linkov]

> A pure condition/rule analogy is hard to achieve.  IIUC, for example,
> `even-window-sizes' would be a rule.  This rule works on the conditions
> that the window used and the selected window are adjacent, one of them
> is higher, ...  Would these be conditions?

These are not conditions.  They are post-actions, i.e. the final actions
to be called after performing base actions, so merging should take care
of putting `even-window-sizes' after window splitting, etc.

Moreover, I suspect that `even-window-sizes' is unnecessary.
Using `balance-windows' at the end of the action part of the rule
should do the same.  Their functionalities are conceptually similar,
so I think they should be joined to `balance-windows'.

> I'm not sure what you mean by "merging actions".  How would you "merge
> in" the Emacs 23 default behavior of evening window heights?

In Emacs 23, `display-buffer' called `window--even-window-heights'
unconditionally.  So calling it from the action part of the rule
should be equivalent.