Re: Display of undisplayable characters: \U01F3A8 instead of diamond

[Eli Zaretskii <eliz@gnu.org>]

> From: Emanuel Berg <incal@dataswamp.org>
> Date: Sat, 10 Sep 2022 06:41:32 +0200
> 
> Eli Zaretskii wrote:
> 
> >> Situation: You want to do this, f(x) = y.
> >> 
> >> Problem: f(x) is expensive to compute.
> >> 
> >> Solution: Compute it ONCE, then store f = ((x y) ...) in
> >> a cache data file, so next time f(x) = y is needed, instead of
> >> computing f(x) again search the data file - search, which
> >> _isn't_ expensive.
> >
> > And I ask again: why does it matter whether you record
> > a program or its data
> 
> If you store the result of running the program you don't need
> to execute the program again next time you need the result,
> instead you search for it and retrieve it, simple as that.

That's what the current implementation does.  It just stores the
results as a (much faster) program to be run at Emacs startup time,
that's all.  AFAIU, your proposal is to store just the ranges of
problematic characters, which would require to run, at Emacs startup
time, another program to read those ranges and issue the calls that
the current implementation embeds in the stored results.

Which is why I think there's no real difference between the two
approaches, and I consider the current implementation be slightly
better, since the risk of getting the startup calls wrong is somewhat
lower.