martin rudalics <rudalics@gmx.at> writes:

>>> Either way I would consider these functions useful and would have
>>> wanted
>>> to use them in my own code many times before.  While difficult, it
>>> might
>>> also be useful for things like display-buffer-alist (the issue is that
>>> a function as a condition in display-buffer-alist has to accept two
>>> arguments, while the proposed patch only takes one).
>>
>> Hm...  how would this be used with display-buffer-alist, then?  (And
>> perhaps Martin has some comments; added to the CCs.)
>
> Either add an optional second argument to 'buffer-match' or add to
> 'display-buffer-alist' an entry that uses a function as condition that
> calls 'buffer-match' with the first argument and returns non-nil if
> 'buffer-match' reports a match.  I see no issue here.

This seems to work, and updating window.el was also pretty trivial
(unless I have missed something):