Re: /srv/bzr/emacs/trunk r101338: * lisp/emacs-lisp/syntax.el (syntax-ppss): More sanity check to catch

[Dmitry Gutov]

> On 12.02.2014 03:30, Stefan Monnier wrote:
> > One option is to have a hook that takes a (POS . PPSS) pair, which
> > syntax-ppss intends to use as a starting point for parsing, and return
> > a new such pair to use instead, where the returned position should
> > always be >= POS.

A problem: suppose point is in a primary mode region, and POS is in a 
submode region above it. Then we can't use the value of PPSS at all.
Does the hook re-scan the buffer from the beginning?

On 12.02.2014 04:49, Dmitry Gutov wrote:
> We call `syntax-ppss', happily report to it that the value at point (or
> some position near it) can be used until point + 400. Then move a few
> chars lower and delete the rest of the given region. NEXT-BOUNDARY
> becomes stale, and calling `syntax-ppss' from the region below can
> return a wrong value.

I suppose this could be handled if `syntax-ppss-flush-cache' removed or 
modified the cache entries where NEXT-BOUNDARY is after BEG. And by 
modified, I mean set NEXT-BOUNDARY to BEG.