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

[Dmitry Gutov]

On 14.02.2014 19:08, Stefan Monnier wrote:
> > Last time I checked, web-mode wasn't in this category: it's a major mode
> > with explicit support for some templating languages.
>
> That's right, it doesn't try to handle major modes generically, but it
> does have to solve similar problems, just with the benefit of being able
> to custom-make its major modes.

I'm not sure what you mean. web-mode has only one major mode, and its 
support of multiple template engines looks like this in the code:

(defun web-mode-scan-blocks (reg-beg reg-end)
...
        (cond
         ((string= web-mode-engine "php")
...
         ((string= web-mode-engine "django")
...
         ((string= web-mode-engine "erb")
...

and so on.

> > mmm-mode would require a hunt for CA signatures, but it's not outside the
> > realm of possibility.
>
> The way I see it rather is to start over from scratch, based on the
> experience gained with mmm-mode, but with a different view: instead of
> trying to make it work without changing existing modes, assume that
> the major modes will be changed to fit the framework.
>
> The result should be much simpler/cleaner/shorter.

The implementation of region classes definitions and parsing of the 
buffer could still be reused with this approach. Although, if the goal 
is to parse the buffer lazily, maybe adapting the relevant multi-mode 
code instead would be easier.

> I tend to assume that mode switches shouldn't be that super frequent to
> be a real performance problem, and that if they need to be sped up,
> there are ways to do that, e.g. by providing a few "subr", so I'm not
> too worried about it.

Ok.