[bug#31399] [PATCH] import: elpa: Implement recursive import.

[Ricardo Wurmus <ricardo.wurmus@mdc-berlin.de>]

Hi,

Ludovic Courtès <ludo@gnu.org> writes:

> Oleg Pykhalov <go.wigust@gmail.com> skribis:
>
>> I stole recursive importer from ‘cran’ and made it for ‘elpa’, the patch
>> is attached.  I don't like it and want to share the code with ‘cran’
>> importer, but I don't know how to do it without increasing complexity.
>
> Indeed.  Ricardo and I discussed this in the past and Ricardo started
> implementing something:
>
>   http://lists.gnu.org/archive/html/guix-devel/2016-08/msg00381.html
>
> It would be great to resume work on this, especially since we have other
> importers that would immediately benefit from it (CRAN, Go, Crates).
>
> The solution I proposed back then was to have importers return a SRFI-41
> lazy stream of package definitions.

The CRAN importer supports recursion and it is implemented with SRFI-41
lazy streams and AIUI this is what this patch does for the elpa
importer.

We should move “recursive-import” to “(guix import utils)” and let it
take the package generator procedure (e.g. “cran->guix-package”) as an
argument.  It looks like this patch copied “recursive-import” and
changed little more than “cran->guix-package” to “elpa->guix-package”,
so this seems like a simple change.

--
Ricardo