[plt-scheme] Annotative forms in expand-program?

[Matt Jadud <mjadud@cs.indiana.edu>]

	I was thinking I was all set in using the expanded form of a program,
and I'd gain magical compatibility with any program implemented in DrScheme.

The program

(define (fact n)
  (if (zero? n)
      1
      (* n (fact (n (- n 1))))))

Expands as follows under the language setting "Textual MzScheme":

(define-values
  (fact)
  (lambda (n)
    (if (#%app (#%top zero?) n)
	(#%datum 1)
        (#%app (#%top *) n (#%app (#%top fact)
				  (#%app (#%top -) n (#%datum 1)))))))

Under the "Beginning Student" language, however, I get the following:

(begin
 (#%app check-top-level-not-defined (quote define) (quote-syntax fact))
 (define-values (fact)
   (lambda (n)
     (if (#%app verify-boolean (#%app zero? n) (quote if))
	 (#%datum 1)
       (#%app * n (#%app (#%top fact)
			 (#%app - n (#%datum 1))))))))

I had to fgrep through the collections directory to find, in the "private"
subdirectory of the "lang" collection the string "check-top-level." These
run-time extentions for use in Beginner Scheme show up in the expansion of the
definitions window; if any language can introduce arbitrary code to be
evaluated at run-time into the primitive language, how do I handle expressions
defined in modules that have no meaning in the language of my compiler?

	I thought I had a handle on this, but perhaps I didn't; am I missing
something very obvious?

	Thanks,
	Matt

________________________________________________________________________
Matt Jadud                            http://www.cs.indiana.edu/~mjadud/
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