Re: [Emacs-diffs] master 8dafacd: * lisp/emacs-lisp/syntax.el (syntax-ppss-table): New var

[Dmitry Gutov]

On 01/19/2016 01:12 AM, Stefan Monnier wrote:
> > Doesn't paren-matching code call syntax-ppss anyway?
>
> Not that I know, no.

electric-pair-syntax-info calls syntax-ppss. blink-matching-open calls 
(forward-sexp -1).

> Yes, this whole area is rather murky.  The font-lock syntax-table should
> mostly disappear (90% of the uses were to turn "_" syntax into "w"
> syntax so as to be able to use \< and \>, but this has been made
> obsolete by the new \_< and \_>), I think.

font-lock-syntax-table should go away, yes. But it's still there.

Are current-syntax-table and syntax-ppss-table allowed to differ more 
than that?

> E.g. in TeX and HTML, we want to match parentheses even though the formal
> syntax does not give any special rule to parentheses.  Similar thing for
> matching parens when the open and close parens are both inside comments,
> but not inside the same one.

Multiple major modes strike again! Or multiple syntactic regions, 
anyway. I'm not sure if having a different value of syntax-table (any 
variable) between different comments will help us any.

> > But up-list uses the return value of syntax-ppss, so it will be affected by
> > syntax-ppss-table?
>
> syntax-ppss is indeed used, but only to decide if we're strings or
> comments, so it should be OK.

Never for its 9th element?

> > It doesn't seem easy to reason about.
>
> Indeed, it's not.

So, I'm wondering if we could postpone introducing a new variable, and 
implement the same thing in nxml-mode somehow in a different way.

But you've probably already considered that.