To make the intent clear in Lisp one would use UNTIL (NULL list) or WHILE (NOT (NULL list)) . NULL is a predicate which does the same as NOT, but makes the int

To make the intent clear in Lisp one would use UNTIL (NULL list) or WHILE (NOT (NULL list)) . NULL is a predicate which does the same as NOT, but makes the intent clear. It also allows to move the code to a dialect where NIL and FALSE are different.