consp (Function)

Syntax:

Arguments and Values:

object—an object.

generalized-boolean—a generalized boolean.

Description:

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

Examples:

 (consp nil) → false
 (consp (cons 1 2)) → true

The empty list is not a cons, so

 (consp '()) ≡ (consp 'nil) → false

See Also:

listp

Notes:

 (consp object) ≡ (typep object 'cons) ≡ (not (typep object 'atom)) ≡ (typep object '(not atom))