Re: Partly deferred font-locking?

[Eli Zaretskii]

> From: Michael Heerdegen <michael_heerdegen@web.de>
> Date: Wed, 11 Jan 2023 18:15:19 +0100
> 
> Is it somehow possible to defer (only) the more expensive parts of
> font-lock using a timer?  A use case would be the symlink-target
> checking fontification rules in dired: the need to check the target file
> properties makes scrolling large dired buffers sluggish.
> 
> It seems there are only global settings available that also always
> influence font-locking completely as a whole (`jit-lock-stealth-time',
> `jit-lock-defer-time').

Yes.

> Are there other ways?  Or would it be worth to implement?

I think it's basically impossible to know up front which parts of
fontifications will be expensive and which won't.  For starters, it
depends on the text around the window.