On Fri, Jul 30, 2021 at 3:31 AM Marc Nieper-Wißkirchen <xxxxxx@gmail.com> wrote:

As a proof-of-concept, I once implemented "identifier syntax" for CHICKEN's expander. I extended CHICKEN's syntax-rules to allow the above example (and, yes, the clauses are in the wrong order). Possibly, this project is what John refers to.

Yes, it is. But why should the order matter in syntax-rules? As I just posted, syntax-rules requires every top-level pattern to be a list (see the definition of <srpattern> in 11.19), and an identifier is neither.