Re: user-init-file source vs. compiled

["Juanma Barranquero" <lekktu@gmail.com>]

On 2/2/07, Stefan Monnier <monnier@iro.umontreal.ca> wrote:

> 10% smaller will result in a non-measurably faster load, and will still take
> 90% more disk space.  So what's the advantage again?

The wonderful, perhaps subjective feeling that it is loading faster :)

> I don't want to make it impossible to byte-compile your .emacs.  If that's
> really what you want, go for it.

I've been using Emacs for nine years and I just started to
byte-compile my .emacs a week ago, so it's not a matter of me "really
wanting". This thread was about a variable's description being
inaccurate (fortunately it is now fixed).

> I'm just saying that we should discourage
> people from doing that, because too many users think "oh Emacs takes a long
> time to start, I bet if I byte-compile it it'll start faster", but it turns
> out it's not faster and next time they forget to re-compile their .emacs
> they get bitten.

I've added this to my site-start.el:

(catch 'init-file
  (dolist (source-file '("~/.emacs.el" "~/.emacs." "~/_emacs.el"
                         "~/_emacs" "~/.emacs.d/init.el"))
    (when (file-exists-p source-file)
      (require 'bytecomp)
      (unless (fboundp 'time-less-p) (require 'time-date))
      (let ((byte-file (byte-compile-dest-file source-file)))
        (when (and (file-exists-p byte-file)
                   (time-less-p (nth 5 (file-attributes byte-file))
                                (nth 5 (file-attributes source-file))))
          (unless (byte-compile-file source-file)
            (setq init-file-user nil))))
      (throw 'init-file t))))

which recompiles my .emacs.el if needed (the compilation log is quite
visible, so I don't miss that something happened), with the added
benefit that .emacs(.elc?)? is not loaded if the compilation fails.

> It's not the most common problem on gnu.emacs.help, but
> it's sufficiently common that I think the potential very minor advantage(s)
> is just not worth it.

By all means, if you think users should not compile their .emacs
unless they know what they're doing, just add a prominent notice to
the relevant docs. You're talking about what should we recommend; I
was just talking about not misleading people, given the fact that
bytecompiling .emacs is *allowed*. I have no opinion on whether we
should en- or discourage bytecompiling the init file.

> OTOH I'm in favor of adding some kind of hack so that the .emacs file
> automatically goes through the byte-compiler's sanity checks when you save
> it (so they user might can warnings about using obsolete
> variables/functions).

That's a really nice idea.

                    /L/e/k/t/u