Panicz,

you will then want to revise your pattern language (just before
"Incompatible features should not be used") to exclude nested
quasiquotes.

PS How do you match the symbol ... with the restrictions of SRFI 200?

Without restrictions, the "WCS" matcher can match it as in

(match x (('... <output>)))

And the "FHD" matcher as in

(match x ((,id (guard (eq? '... id)) <output>)

Am Mo., 31. Aug. 2020 um 11:52 Uhr schrieb Panicz Maciej Godek
<xxxxxx@gmail.com>:
>
> As to SRFI-200, I have been considering that a while ago, and decided to leave it unspecified:
> patterns containing nested quasiquotes are more confusing than they are useful, and there's usually a better way to achieve whatever is meant to be achieved by their means.
>
> I can make the "unspecification" explicit for clarity.
>
> pon., 31 sie 2020 o 11:43 Marc Nieper-Wißkirchen <xxxxxx@nieper-wisskirchen.de> napisał(a):
>>
>> I guess that nested quasiquote patterns are supposed to behave as the
>> quasiquote syntax of R7RS (as in which unquotes are inserted literally
>> and which unquotes escape the quasiquote) .
>>
>> However, I don't find anything about it in the specification yet.
>>
>> This is also relevant for the main thesis in SRFI 200:
>>
>> Given the pattern (quasiquote (quasiquote (unquote x))), the SRFI 204
>> matcher will probably match the pattern (quasiquote (unquote x))
>> literally. The SRFI 200-modified "FHD" matcher will, however, match
>> against a more general two-element list whose first element is
>> quasiquote and whose second element will be bound to x.
>>
>> I haven't checked the Racket matcher.
>>
>> Marc