CLHS: Function LISTP

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Function LISTP

Syntax:

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

Side Effects: None.

Affected By: None.

Exceptional Situations: None.

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))

Copyright 1996-2005, LispWorks Ltd. All rights reserved.