Quick Reference

A value that cannot be decomposed further. In Lisp an atom is a representation of an arbitrary string of characters or the special atom NIL, i.e. nothing. The word is also used as a predicate in Lisp-like languages to determine whether an arbitrary value is or is not an atom:

(atom (cons(h, t)))

always yields FALSE but

(atom, NIL)


(atom, “word”)

evaluate to TRUE.

Subjects: Computing.

Reference entries