CLCS
Function

atom

atom objectgeneralized-boolean

Arguments and Values

objectan object.
generalized-booleana generalized boolean.

Description

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

Examples

 (atom 'sss) ⇒  true
 (atom (cons 1 2)) ⇒  false
 (atom nil) ⇒  true
 (atom '()) ⇒  true
 (atom 3) ⇒  true

Notes

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