RE: What's the canonical way to check "alistp"?

[Drew Adams]

> What's the best way to check if every element in a list is also a list?

Also a _list_ or also a cons? Do you want (alistp '(()))
to return true?  I'm guessing no.

(defun alistp (xs)
  "Return non-nil iff XS is a list and each element is a cons."
  (and (listp xs)
       (catch 'alistp
         (dolist (x  xs) (unless (consp x) (throw 'alistp nil)))
         t)))

(The code should not bother to check each element if it
finds one that is not a cons.)