bug#42267: Fontification takes a long time when an equation contains a double prime

[Najib Idrissi-Kaïtouni]

Hi,

Yes, this is much, much better with this patch. I don't experience any 
noticeable slowdown anymore, whether in the test file or in my "real 
world" file. Thanks!

Best regards,
Najib Idrissi

Le 09/07/2020 à 18:37, Ikumi Keita a écrit :
> Hi Najib,
>
> > > > > > Najib Idrissi <najib.idrissi.kaitouni@gmail.com> writes:
> > Sure, see the attached file. As I said, it's a file filled with lipsum
> > with a single equation at the bottom.
> > > AUCTeX's fontification for math went through a bigger overhaul.  Please
> > > share the file and a recipe (preferably starting with `emacs -Q') how to
> > > trigger your obeservation, that would help a lot.
> > 1. Open the file and go to the equation at the bottom
> > 2. Notice that editing speed inside the equation is normal (e.g. hold
> >     the space bar inside the equation and notice that it goes at a
> >     normal speed)
> > 3. Add a double prime somewhere in the equation, e.g. after the 2 so
> >     that it becomes 1+1=2''
> > 4. Notice that now editing speed is degraded, for example hold the
> >     space bar at the end of the equation and notice that there is now a
> >     stutter. If your CPU is too fast and you don't notice the stutter,
> >     you can just copy more paragraphs of lipsum, I guess.
> > In my real life example (that I cannot share because the article in
> > question is not public yet) the slowdown is so bad that a single
> > keystroke inside an affected equation can take several seconds.
> Thank you for providing concrete example and procedure to reproduce. I
> experience the slowdown you described.
>
> The attached patch fixes, or at least reduces, the slowdown on my side.
> Could you check whether it works for you or not?
>
> Best Regards,
> Ikumi Keita