bug#54296: Add buffer-matching functionality

[Philip Kaludercic <philipk@posteo.net>]

Augusto Stoffel <arstoffel@gmail.com> writes:

>>> +  * `not': the cdr is interpreted as a negation of a condition.
>>> +  * `and': the cdr is a list of recursive condition, that all have
>>> +    to be met.                            ^^^^^^^^^
>>
>> Typo: should be "conditions".
>>
>>> +  * `or': the cdr is a list of recursive condition, of which at
>>> +    least one has to be met."            ^^^^^^^^^
>
> In 'font-lock-ignore' you can prefix an or-condition with !, with the
> gitignore semantics.  This seems very appropriate for a buffer-matching
> functionality.
>
> But then `or' is not the familiar short-circuiting
> operation, and you need to evaluate the conditions backwards...
>
> On a more bikesheddy note, I'm also debating a bit what is more
> readable:
>
>     (or cond1 cond2 ! cond2)
>
> or else
>   
>     (or cond1 cond2 (except cond2))

If this would be included, I would certainly prefer the latter.

-- 
	Philip Kaludercic