> Also, I think it should process fields, and return an alist, or even
> better, a ‘gnu-package-descriptor’ record (say).
>
>   (define-record-type <gnu-package-descriptor>
>     gnu-package-descriptor?
>     (gnu-package-descriptor name logo-url doc-category ...)
>     ...
>     )
>
>   (official-gnu-packages)
>   => (#<gnu-package-descriptor name: "guix" logo-url: "http://..." ...#> ...)
>
> WDYT?

Oh, I forgot about this when I was writing the attached patch.  Is it
fine?  Should I rewrite it using records?

I guess that it will work faster if I use 'cons' in 'loop' instead of
'append'.  Is it worth it?

Examples:

scheme@(guile-user)> ,use (guix gnu-maintenance)
scheme@(guile-user)> (find-packages "guix")
$1 = (("package: guix" "logo: /software/guix/graphics/guix-logo.small.png" "doc-category: Sysadmin" "doc-summary: Managing installed software packages and versions" "doc-url: none" "gplv3-status: should-be-ok" "activity-status: newpkg/20121117"))

This one:

  (find-packages "guile")

should return several packages.