On Feb 24, 2013, at 08:40 PM, Stefan Monnier wrote:

>It used to be the case that compiling one's .emacs was silly because it
>provided no measurable speed difference.  But nowadays this is not true
>any more: loading a source Elisp file is significantly slower because it
>goes through load-with-code-conversion.

I didn't know that, and it's a shame for me because I've loaded all my
personal emacs files as source since the beginning of time (makes it easier to
integrate them with revision control systems).

>So basically, all we need to do is to be able to easily recognize "Elisp
>source in utf-8 encoding".  One way to do that would be to use
>a BOM-like marker, e.g. start utf-8 Elisp files with "\ufeff" either at
>the very beginning of the file or right after a semi-colon (for better
>backward compatibility).

Stephen's suggestion of assuming utf-8, with -*- overriding and warnings if
the end of file encoding landmarks don't match seems reasonable to me.

Cheers,
-Barry