Re: Split `simple.el'?

[Eli Zaretskii]

> From: Stefan Monnier <address@hidden>
> Cc: Paul Eggert <address@hidden>, address@hidden
> Date: Wed, 04 Apr 2018 09:14:43 -0400
> 
> > IOW, it's a system configuration bug: with such a large number of
> > fonts, one should have at least one font that covers each Unicode
> > codepoint, and one might need to customize their fontsets to find the
> > fonts more quickly.
> 
> Maybe we should setup some cache to avoid always recomputing this.

I think we already do: the realized fontset is implemented as a
char-table, where we record that a character has no fonts in the
fontset.

The underlying problem in this case happens when such characters need
to be displayed for the first time.

Maybe you mean a persistent cache on disk?  If so, Unix back-ends
already have that, AFAIK.  But Drew is on Windows.  Maybe Emacs on
Windows could also benefit from some system-wide caching, but I don't
know if something like that exists, or how to change Emacs to use it
if it does.  Or maybe the methods we use already employ what caching
is there, and this is the best we can do.

In any case, setting up a cache would mean it needs to be updated each
time a font is installed or removed.