modf
An immutable setf.

Example:

(defparameter *crazy* '(1 #(a (2 #(b (3 #(c (4 t)))))))) ==> *CRAZY*

Change the last t to nil with modf:

(modf (cadr (aref (cadr (aref (cadr (aref (cadr *crazy*) 1)) 1)) 1)) nil) ==> (1 #(A (2 #(B (3 #(C (4 NIL)))))))

Original data is unchanged:

*crazy* ==> (1 #(A (2 #(B (3 #(C (4 T)))))))

Homepage: GitHub

License: BSD

See Also: versioned-objects

Topics: language extension