Worth noting: the most prominent post-R5RS Scheme I can think of with a
pre-SRFI-46 syntax-rules expander is Gerbil, and Gerbil supports
syntax-case and the #'(... ...) trick, so it should be possible to make
an alternate implementation work in Gerbil too.

On 8/30/20 4:33 AM, Marc Nieper-Wißkirchen wrote:
> "..." would only be a problem for implementation with a pre-SRFI 46
> syntax-rules expander. But these can possibly cope with "___".
>
> Am So., 30. Aug. 2020 um 02:15 Uhr schrieb John Cowan <xxxxxx@ccil.org>:
>> We already have ..., so let's just leave it at that.
>>
>> On Sat, Aug 29, 2020 at 7:46 PM Felix Thibault <xxxxxx@gmail.com> wrote:
>>> Is there a particular substitute, like ^^^, :::, ???, or something else that appeals to anyone?