Re: emacs packages

[Ludovic Courtès]

Federico Beffa <address@hidden> skribis:

> To be concrete about what I'm proposing, attached you find:
>
> - An ELPA package importer
> - An 'emacs-build-system'

Sounds very useful to me!

> There are a lot of Emacs packages. For this reason I would like to
> propose to prefix them with 'emacs-' as we do with Python, ...

Sounds good.  I think I prefer ‘emacs-’ to ‘el-’ because that’s probably
what people expect.

> To make those packages automatically available in Emacs without the
> need for any code in the user '.emacs' file, I would suggest to
> include in our Emacs package site initialization file some custom code
> (to activate our ELPA emacs packages) such as the one in the attached
> 'guix-elpa.el' file.

guix.el already takes care of that (info "(guix) Emacs Initial Setup"),
so that should be enough.

Some random comments:

> ;; Path relative to 'out' where we install ELPA packages.  We avoid the
> ;; ".../elpa" path as Emacs expects to find the ELPA repository
> ;; 'archive-contents' file and the archive signature.
> (define guix-elpa-packages-path "/share/emacs/site-lisp/guix.d")

Rather %install-suffix (“path” is used exclusively to refer to search
paths in GNU.)

> (define* (build #:key outputs inputs #:allow-other-keys)
>   "Compile .el files."
>   (let* ((emacs (string-append (assoc-ref inputs "emacs") "/bin/emacs"))
>          (out (assoc-ref outputs "out"))
>          (name-ver (store-dir->elpa-name-version out))
>          (el-dir (string-append out guix-elpa-packages-path "/" name-ver)))

Please align the lets.  :-)

>       (fold (lambda (f s)
>               (and s (zero? (system* emacs "--batch" "-Q" "-L" el-dir
>                                      "-f" "batch-byte-compile" f))))
>             #t (find-files "." "\\.el$")))))

Should probably use ‘emacs-batch-eval’ from (guix build emacs-utils),
and perhaps define ‘emacs-byte-compile’ there.

> (define* (copy #:key outputs #:allow-other-keys)
>   "Copy the package content to the installation directory."

s/copy/install/ ?

> ;; from (guix utils).  Should we put it in (guix build utils)?
> (define (package-name->name+version name)
>   "Given NAME, a package name like \"foo-0.9.1b\", return two values:

Yes, should probably be moved to (guix build utils) eventually.

Thanks for the great initiative!

Ludo’.