Re: Request for site-lisp-directory

[David Kastrup <dak@gnu.org>]

Piet van Oostrum <piet@cs.uu.nl> writes:

>>>>>> David Kastrup <dak@gnu.org> (DK) wrote:
>
>>DK> Piet van Oostrum <piet@cs.uu.nl> writes:
>>>> I want to make a plea for a new lisp-level variable
>>>> `site-lisp-directory' similar to `data-directory' and
>>>> `exec-directory'. In my AUCTeX tex-site.el I now have:
>>>> 
>>>> (defvar TeX-lisp-directory
>>>> "/Applications/Emacs.app/Contents/Resources/site-lisp/auctex" ...
>>>> 
>>>> I would prefer the location-independent:
>>>> 
>>>> (expand-file-name "auctex" site-lisp-directory)
>>>> 
>>>> Of course it is possible to say:
>>>> (defvar site-lisp-directory (expand-file-name "../site-lisp"
>>>> data-directory)) but I think it is cleaner if this is setup by the
>>>> initialization code.
>
>>DK> Hold your horses.  I am right now overhauling the installation
>>DK> procedure of AUCTeX, and indeed it will make TeX-lisp-directory (and
>>DK> other stuff) typically be set to a relative path location (namely
>>DK> something like
>>DK> (expand-file-name "something" (file-name-directory load-file-name))
>
>>DK> This is more a problem of the installation procedure of AUCTeX rather
>>DK> than Emacs.
>
> It is not only AUCTeX; I just use that as an example. I have more
> packages installed in site-lisp and some of them require a variable
> set to their location or a location of one of their files. Emacs
> knows the site-lisp directory because it puts it in load-path, so it
> could easily put it in a variable also.

I just explained that it is no good to assume that there is only a
single possible directory relative to site-lisp where a package may be
installed, since some packages come in package systems delivered by
the OS vendor, some packages get installed by the site administrator,
and some packages get installed by the user himself, and in some cases
those installations are even in parallel.  The only scheme that has a
marginal chance of working is locating stuff relatively to
(file-name-directory load-file-name).

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum