Re: replacing hexl-mode with nhexl-mode?

[Eli Zaretskii <eliz@gnu.org>]

> Date: Tue, 22 Mar 2022 22:03:43 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: emacs-devel@gnu.org
> 
> > From: "Alfred M. Szmidt" <ams@gnu.org>
> > Cc: emacs-devel@gnu.org
> > Date: Tue, 22 Mar 2022 15:37:13 -0400
> > 
> >    > Wouldn't it be nice to replace hexl-mode with nhexl-mode?  Are there
> >    > any reasons not too?
> > 
> >    I think we found nhexl-mode to be much slower in some cases.
> > 
> > Do you recall what those cases might have been?
> 
> Stefan should answer that.  What I remember was 10 years ago, and
> maybe was solved since then.

Btw, some problems can be seen almost right away.  Try this:

  C-x C-f etc/HELLO
  M-x nhexl-mode RET

The display is much less tidy, to say the least, than with hexl.el.
It looks like the fancy display of LF is the culprit, at least on my
system (font issues?)  Now try scrolling with C-n, and you will see
stuttering that isn't there with hexl.

There's a also a larger, more subtle problem: nhexl shows you the
internal representation of the buffer text, not what's in the file on
disk; this matters a lot when the file has non-ASCII text.  You need
to be aware of that and visit the file literally if you want to avoid
this issue (there's no nhexl-find-file command).

Finally, nhexl causes display problems when invoked in buffers
text using bidirectional scripts.  Try this:

  C-x C-f etc/tutorials/TUTORIAL.he RET
  M-x nhexl-mode RET

Lots of fun!