CLCS
src report error
Index
function-lambda-expression Data and Control Flow Dictionary compiled-function-p
Function

functionp

functionp object ⇒ generalized-boolean

Arguments and Values

objectan object.
generalized-booleana generalized boolean.

Description

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

Examples

 (functionp 'append) ⇒  false
 (functionp #'append) ⇒  true
 (functionp (symbol-function 'append)) ⇒  true
 (flet ((f () 1)) (functionp #'f)) ⇒  true
 (functionp (compile nil '(lambda () 259))) ⇒  true
 (functionp nil) ⇒  false
 (functionp 12) ⇒  false
 (functionp '(lambda (x) (* x x))) ⇒  false
 (functionp #'(lambda (x) (* x x))) ⇒  true

Notes

 (functionp object) ≡ (typep object 'function)

Backlinks

Data and Control Flow Dictionary, Function Forms, Symbols in the COMMON-LISP Package