Re: Guile Introspection

["Marco Maggi" <marco.maggi-ipsu@poste.it>]

Ciao,

"Mike Gran" wrote:
>Or, what is the scheme version of the following C code
>
>printf("%s %d\n", __FILE__, __LINE__);

I like a solution that redefines DEFINE without introducing
an environment in the body of the function. To do it: you
have to take the body in question and treat it as a tree,
mapping selected symbols to the values you want.

If I am correct in assuming that you are a Scheme beginner
and the following code is no clear enough, just ask.

;; ----------------------------------------

(define (map-tree func tree)
  (map (lambda (v)
	 (if (list? v)
	     (map-tree func v)
	   (func v))) tree))

(define (subst-tree old new tree)
  (map-tree (lambda (v)
	      (if (eq? old v) new v)) tree))

(define saved-define define)

;; ----------------------------------------

(define *current-file-name* "proof.scm")

(define-macro (define name-and-args . body)
  (let* ((fname	(symbol->string (car name-and-args)))
	 (args	(cdr name-and-args))
	 (body1 (subst-tree
		 '*current-file-name* *current-file-name*
		 (subst-tree '*current-function-name* fname body))))
    `(saved-define ,name-and-args ,@body1)))

;; ----------------------------------------
;; tests

(define (my-func)
  (format #t "file: ~A, func: ~A~%"
	  *current-file-name*
	  *current-function-name*))

(define (other-func alpha beta)
  (format #t "file: ~A, func: ~A, a ~A, b ~A~%"
	  *current-file-name*
	  *current-function-name*
	  alpha beta))

(define (further-func . args)
  (apply format #t "file: ~A, func: ~A, a ~A, b ~A~%"
	 *current-file-name*
	 *current-function-name*
	 args))

(my-func)
(other-func 123 'abc)
(further-func 123 'abc)

--
Marco Maggi

"They say jump!, you say how high?"
Rage Against the Machine - "Bullet in the Head"



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