Am Mi., 9. Nov. 2022 um 18:26 Uhr schrieb Lassi Kortela <xxxxxx@lassi.io>:
>
> >> I've updated<https://registry.scheme.org/#hash-syntax>  and added the
> >> following note: "A quote ' next to an implementation's name means the
> >> syntax must be quoted in that implementation."
>
> > The syntax itself does not need to be quoted.  If you want to make it
> > a valid Scheme expression, you have to use the quote expression from
> > the standard.
> >
> > In any case, this is not a Chez thing, but an R[56]RS thing; many
> > syntactic data (vectors, bytevectors, ...) do not form a valid
> > expression.
>
> Chez says "Exception: invalid syntax #&123". So that means "invalid
> expression syntax", not "invalid lexical syntax"?

Yes.

> > I don't think your note belongs to this table in the Scheme registry.
> > For otherwise, you would need the same note for vectors, bytevectors,
> > etc. at least for R[56]RS implementations.
>
> Adding the same note for the vector types would be a helpful reminder
> IMHO. The R6 vs R7 vector quoting discrepancy is easily missed, for example.

Then I would create a new table about how expressions can be formed,
especially constants.

> > Moreover, the table is about lexical syntax and #&123 is a valid
> > lexical syntax (in Chez Scheme mode): Just enter (read) at the REPL
> > and then enter #&123.
>
> I still find the notes helpful and would like to keep them. Can you
> supply a better worded sentence? Something like this perhaps:
>
> "A quote ' next to an implementation's name means the syntax is not
> self-evaluating in that implementation, and must be quoted to form a
> valid expression."

That would still be a category error (categorial? categorical?).

Keep this sentence but next to a table with syntactic data representations.

PS I made a mistake; bytevectors in R6RS are valid expressions
("self-quoting"), which makes sense because they do not contain
general syntactic Scheme data.