[racket] Delimiting scope

Bonjour,

I have tested this code:

;;;;
#lang racket

(require
 (for-syntax racket))

(define-syntax (delimit-scope stx)
  (syntax-case stx ()
    [(_ form)
     ((make-syntax-introducer)
      (datum->syntax #'here (syntax->datum #'form)))]))

(define z 13)

(let ([z 14])
  (delimit-scope
   z))
;;;;


And it capture the module level binding.


So i have write another version, this one check all identifier from stx and
raise an exception if it is bind at module level:

;;;;
#lang racket

(require
 (for-syntax racket))

(define-syntax (delimit-scope-bis stx)
  (syntax-case stx ()
    [(_ form)
     (let ([marked (syntax-local-introduce (datum->syntax #'here (syntax->datum #'form)))])
       (if (and (identifier? marked)
		(list? (identifier-binding marked)))
	   (raise (format "~a cannot be lexical scoped" (syntax->datum marked)))
	   (let loop ([lst (syntax->list marked)])
	     (when (not (empty? lst))
	       (let ([f (first lst)])
		 (cond [(and (identifier? f)
			     (list? (identifier-binding f)))
			(raise (format "~a cannot be lexical scoped" (syntax->datum f)))]
		       [(syntax->list f)
			(loop f)])))))
       s)]))

(define a 13)

(let ([a 12])
  (delimit-scope-bis
   a))

uncaught exception: "a cannot be lexical scoped"
;;;;

Is there a way to delimit module level bind using syntax mark mechanisme?
Can i view the syntax marks of a syntax object?