make-get-set.lisp

;;; http://xen.garden/wp/?p=25

; Common Lisp version by Rainer Joswig, [email protected], 2016

(defun create-symbol (prefix suffix)
  (intern (format nil "~a-~a" prefix suffix)
          (symbol-package suffix)))

(defun make-get-set (name
                     &aux
                     (getter (create-symbol "GET" name))
                     (setter (create-symbol "SET" name)))
  (let ((val nil))
    (setf (symbol-function getter) (lambda () val)
          (symbol-function setter) (lambda (new-val) (setf val new-val)))
    (values)))

(mapc #'make-get-set '(bat cat fat))

; Using it:

; CL-USER 23 > (mapc #'make-get-set '(bat cat fat))
; (BAT CAT FAT)

; CL-USER 24 > (get-bat)
; NIL

; CL-USER 25 > (get-cat)
; NIL

; CL-USER 26 > (set-bat 10)
; 10

; CL-USER 27 > (set-cat 20)
; 20

; CL-USER 28 > (get-bat)
; 10

; CL-USER 29 > (get-cat)
; 20