On Sat, Apr 01, 2023 at 07:37:44AM +0200, Pedro Andres Aranda Gutierrez wrote:
> Use case for a nilp function:
> 
> I have a buffer-local variable with a default value, and I want to
> allow to (silently) set it to nil (and only to nil) from
> .dir-locals.el or Local Variables.
> 
> Currently I have
> 
> (defun nilp(v) (unless v t))

If I understand your needs correctly, the function you are
looking for is called `null'.

Yes, it breaks the convention for predicates (i.e. that they
should end in -p), but I think it's just because it has been
there for so long, like an old olive tree :-)

Cheers
-- 
t