Re: [PATCH] Scheme-mode: Add support for regular expression literal

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sat, 30 Mar 2024 00:02:51 +0900
> From: "Toshi Umehara" <toshi@niceume.com>
> Cc: "Stefan Monnier" <monnier@iro.umontreal.ca>, emacs-devel@gnu.org
> 
> Hello Jakub, thank you for testing! I also did not know why there was a
> delay.
> 
> As Eli mentions, I looked up for jit-lock-antiblink-grace, and found it
> is defined as 'customizable' variable.
> 
> M-x customize
> Input jit-lock-antiblink-grace and press Search
> Change value from 2 to something like 0.1
> Apply and Save
> 
> This save the new setting in init.el, and resolves the highlighting
> delay. I feel this is an interesting feature because Emacs seems to
> pretends to be slow, although it can get things done very fast :)

That option exists because some users prefer an instant fontification,
whereas others prefer not to see the momentary "blinking" of wrong
fontification when you have typed "foo bar (with the leading quote),
but didn't yet type the closing quote -- this causes font-lock to
fontify the entire buffer from that place to EOB as a single string.
The 2 seconds of the default value give you 2 sec of grace to type the
closing quote.