On Tue, Sep 17, 2024 at 04:26:19PM +0000, Heime wrote:

[...]

> Is (null x) the part that allows nil, a non-pair object ?

Just ask Emacs:

  (cl-every (lambda (x)
              (or (null x)
                  (consp x)))
            '((foo . bar)
              nil
              (baz . quux)))
  
  => t
  
  (cl-every (lambda (x)
              (consp x))
            '((foo . bar)
              nil
              (baz . quux)))
  
  => nil

Now, should you decide you prefer the second variant, there is
a more concise way of writing it. This is left as an exercise
for the reader.

Cheers
-- 
t