[plt-scheme] a simple macro redux

Let's forget about "syntax" for a minute. Here is a
regular non-hygienic macro that works fine in Common
Lisp but bombs in Scheme:

How would one write the macro mac in Scheme?

(defun fun (n) (cond ((zerop n) nil) (t (cons n (fun
(- n 1))))))

(defmacro mac (n) `(+ ,@(fun n)))

(fun 6) => (6 5 4 3 2 1)
(mac 6) => 21

==========================================

(require (lib "defmacro.ss"))

(define fun
  (lambda (n)
    (cond ((zero? n) '())
          (else (cons n (fun (- n 1)))))))

(define-macro (mac . n) `(+ ,@(fun n)))

> (fun 6)
(6 5 4 3 2 1)
> (mac 6)
. reference to undefined identifier: fun
>

What up?

Michael 



 
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