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I think the parent meant that R6RS has `syntax-rules`, which has enough power to implement CL `defmacro` as well as `syntax-case`.

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My mistake: R6RS has `syntax-rules`, not `syntax-case` as far as I can tell. However, `syntax-rules` and `syntax-case` are equivalent in power. [1]

It does not have the same power as `defmacro`: you cannot define general procedural macros with `syntax-rules`, as you are limited to the pattern-matching language to compute over and construct syntax objects.

[1]: https://docs.racket-lang.org/reference/stx-patterns.html#%28...

I think you got your wires crossed. R5 and R7 only have `syntax-rules` macros. R6 has both (`syntax-rule` can be trivially defined as a `syntax-case` macro).

R6 having `syntax-case` macros is one of the more controversial things about it; a surprising number of implementers don't care for them.

I found the relevant documentation and you are absolutely correct and I was mistaken. Thank you for setting me straight.

https://www.scheme.com/tspl4/syntax.html#./syntax:h3

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