Re: understanding backquote

[Olaf Rogalsky <olaf.rogalsky@aol.de>]

For my amusement, I have written another variation on this subject::

(defun recursive-map (fun expr)
  (funcall fun (if (consp expr)
                   (cons (recursive-map fun (car expr))
                         (recursive-map fun (cdr expr)))
                 expr)))

(defun eval-when-read (expr)
  (if (and (consp expr) (eq (car expr) 'eval-when-read))
      (eval (cadr expr))
    expr))

(defmacro read-wrapper (&rest body)
  (cons 'progn
        (mapcar (apply-partially 'recursive-map 'eval-when-read)
                body)))

(read-wrapper
 (defun test ()
   (eval-when-read (* (+ 1 2) (+ 3 4)))))


Olaf