Re: Removing no-back-reference restriction from syntax-propertize-rules

[Stefan Monnier]

> right now, the docstring of `syntax-propertize-rules' states that
> back-references aren't supported (which is true).  I don't see why that
> has to be the case.  It already shifts numbered groups as needed, so why
> can't it simply shift back-references, too?

The original reason was that I want to compile those to DFAs.

But a secondary reason was that every case where backrefs were used in
`font-lock-syntactic-keywords` was very easy to rewrite to not use
backrefs.  Do you have an example where backrefs are really important in
`syntax-propertize-rules`?


        Stefan