On Wed, May 11, 2011 at 06:06:15PM +0200, Andy Wingo wrote:
> On Wed 11 May 2011 17:25, Peter Bex <Peter.Bex@xs4all.nl> writes:
>
> > The procedures or syntactic forms er-macro-transformer,
> > sc-macro-transformer, syntax-case and syntax-rules already
> > hide the implementation details well enough.
>
> That is true for all but syntax-case.

Of course, you're right.  But then that doesn't matter, if R7RS
only specifies what happens when you do

(define-syntax (syntax-rules ...)) or
(define-syntax (er-macro-transformer ...)) that doesn't shut out
the possibility of syntax-case, does it?

The other way around it does shut out implementations like Chicken
where the "er-macro-transformer" line is more or less optional
because that's its native system.

> You might decide that you don't like it, and that's cool, no
> need to implement it.

Yes, but you do need to restructure things unneccessarily then.
Of course it's a small change and shouldn't break programs
written with syntax extensibility in mind, but it *will* break
some programs I'm sure.

Cheers,
Peter
--
http://sjamaan.ath.cx
--
"The process of preparing programs for a digital computer
 is especially attractive, not only because it can be economically
 and scientifically rewarding, but also because it can be an aesthetic
 experience much like composing poetry or music."
							-- Donald Knuth

_______________________________________________
Scheme-reports mailing list
Scheme-reports@scheme-reports.org
http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports