Re: Scheme Mode and Regular Expression Literals

[Stefan Monnier]

>    (setq-local
>     syntax-propertize-function
>     (lambda (beg end)
>       (goto-char beg)
>       (scheme-syntax-propertize-sexp-comment (point) end)
>       (funcall
>        (syntax-propertize-rules
>         ("\\(#\\);" (1 (prog1 "< cn"
>                          (scheme-syntax-propertize-sexp-comment
>                           (point) end))))
>         )
>        (point) end)
>       ;; For regular expression literals
>       (scheme-syntax-propertize-regexp-1 end)
>       (scheme-syntax-propertize-regexp-2 end)
>       ))))

Does this work for you?
The "funcall" in there is expected to scan through (point)...end and
move point accordingly, so once you call
`scheme-syntax-propertize-regexp-1` you're already "too far".

Instead you need to turn

      (syntax-propertize-rules
       ("\\(#\\);" (1 (prog1 "< cn"
                        (scheme-syntax-propertize-sexp-comment
                         (point) end)))))

into something like:

      (syntax-propertize-rules
       ("\\(#\\);" (1 (prog1 "< cn"
                        (scheme-syntax-propertize-sexp-comment
                         (point) end))))
       ("\\(#\\)/" (1 (prog1 "|"
                        (scheme-syntax-propertize-sexp-comment
                         (point) end))))

and then extend `scheme-syntax-propertize-sexp-comment` so it handles
the case when point is inside a regexp (based on `syntax-ppss`, just
like it currently does for the case where point is inside a sexp-comment).
[ And probably rename it while you're at it since it will not be only
  for "sexp comment" any more.  ]


        Stefan