bug#18826: 24.3.94; c++-mode bad indentation after programmatic insert with locally changed syntax table

[Dmitry Gutov <dgutov@yandex.ru>]

On 10/27/2014 03:53 PM, Alan Mackenzie wrote:

> They (that is, the c-is-sws and c-in-sws properties) mark syntactic
> whitespace.  They're set during calls to c-forward-syntactic-ws and
> c-backward-syntactic-ws, which are used all over the place, just as much
> in the indentation engine, and the commands, as in font lock.  They're
> intended to mark CPP structures and, especially, massive comments, such
> as are frequently found at the beginning of source files.  They're
> intended to speed up the skipping of WS.

It sounds like it can be implemented in syntax-propertize-function 
without much trouble. Adding such props in movement commands sounds 
counter-intuitive, although I can see how this can be useful from the 
performance perspective.

> It's already implemented and running.  :-)  The syntax-table properties
> in the vicinity of a buffer change are removed and re-applied with tender
> loving care.

Cool. It'll require a patch to syntax.el in the trunk, right?

> No it's not.  Apologies.  I hadn't read your email properly.

That's good. I'll take that to mean that < and > having belonging to 
paren class won't stop them from being propertized in the 
before/after-change hooks like you described. Then I'll keep the code 
as-is, thanks!