Re: should definitions introduced by macros be gensymmed?

[Matthew Flatt <mflatt@cs.utah.edu>]

>   (define-syntax define-foo
>     (syntax-rules ()
>       ((_ expr) (define foo expr))))
> 
>   (let ()
>     (define-foo (display 'f))
>     (define-foo (display 'o))
>     (define o 'o)
>     o)
> 
> When I evaluate these in MzScheme (v200alpha15), everything works fine 
> (it displays "foo").  But when I evaluate these in DrScheme (language
> "Textual (MzScheme)"), it complains:
> 
>   def-foo.scm:3:23: letrec-values: duplicate binding name in: foo

This is a bug in MzScheme. If you compose `expand' with itself and
apply the result to the second expression, MzScheme produces the error.

I'm working on it.

Matthew