14.2.17 listp [Function]

listp object ⇒ generalized-boolean

Arguments and Values::

object—an object.

generalized-boolean—a generalized boolean.

Description::

Returns true if object is of type list; otherwise, returns false.

Examples::

 (listp nil) ⇒  true
 (listp (cons 1 2)) ⇒  true
 (listp (make-array 6)) ⇒  false
 (listp t) ⇒  false

See Also::

consp

Notes::

If object is a cons, listp does not check whether object is a proper list; it returns true for any kind of list.

 (listp object) ≡ (typep object 'list) ≡ (typep object '(or cons null))