Indeed. The top google hit for "emacs fontify proof block slow" I provided says exactly that :) https://emacs.stackexchange.com/questions/46561/org-mode-9-too-slow-with-long-code-blocks """ That said, I think keeping 2000 lines of source code inside an org src block is neither a standard use case nor a reasonable idea. You can use the #+INCLUDE ... src ... directive or split the block into a number of more reasonably sized cells. If you insist on keeping the entire block, then disable native highlighting of src code blocks. """ On Mon, Jun 21, 2021 at 2:23 PM John Kitchin wrote: > A quick and dirty way to fix this might be an include file, i.e. move > the block out of your manuscript file into a separate org file, and then > just include it. > > Léo Ackermann writes: > > > Dear all, > > > > I am working in an org-file of reasonable size (<2000 lines): my first > > paper written in org-mode. Everything fine (and fast) until I started to > > add `#+BEGIN_proof / #+END_proof` within my .org to make my .pdf export > > prettier. This caused the editing of the proofs to be very slow: > navigation > > within the proof is fast but adding/removing any char takes around 4s per > > char. > > It seems that the fontify function is responsible for that (see > > screenshot). As far as I understand, this function tries to fontify the > > whole block as soon as a single char is modified. In my case, it then > tries > > to fontify a whole proof (~4 pages in my .pdf, with many LaTeX formulas) > > several times per second... > > > > Is there a way to make this fontify function to act "around my cursor" ? > > > > Best, > > Leo > > > -- > Professor John Kitchin > Doherty Hall A207F > Department of Chemical Engineering > Carnegie Mellon University > Pittsburgh, PA 15213 > 412-268-7803 > @johnkitchin > http://kitchingroup.cheme.cmu.edu > Pronouns: he/him/his > >