From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marius Bakke <mbakke@fastmail.com>
Subject: Re: Parameterized packages
Date: Fri, 10 Jan 2020 00:13:47 +0100
Message-ID: <875zhk1avo.fsf@devup.no>
References: <87woitz1xx.fsf@gnu.org> <87o945vze5.fsf@nckx>
 <8736ldq74z.fsf@netris.org> <20190719202906.lbanx5puk7t6q4cr@cf0>
 <87a7753boq.fsf@ambrevar.xyz> <877e20ansg.fsf@ambrevar.xyz>
Mime-Version: 1.0
Content-Type: multipart/signed; boundary="=-=-=";
 micalg=pgp-sha512; protocol="application/pgp-signature"
Return-path: <guix-devel-bounces+gcggd-guix-devel=m.gmane-mx.org@gnu.org>
Received: from eggs.gnu.org ([2001:470:142:3::10]:33599)
 by lists.gnu.org with esmtp (Exim 4.90_1)
 (envelope-from <mbakke@fastmail.com>) id 1ipgzy-00018B-2s
 for guix-devel@gnu.org; Thu, 09 Jan 2020 18:13:55 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
 (envelope-from <mbakke@fastmail.com>) id 1ipgzw-00026q-SB
 for guix-devel@gnu.org; Thu, 09 Jan 2020 18:13:53 -0500
Received: from wout3-smtp.messagingengine.com ([64.147.123.19]:56577)
 by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32)
 (Exim 4.71) (envelope-from <mbakke@fastmail.com>) id 1ipgzw-0001ze-Br
 for guix-devel@gnu.org; Thu, 09 Jan 2020 18:13:52 -0500
In-Reply-To: <877e20ansg.fsf@ambrevar.xyz>
List-Id: "Development of GNU Guix and the GNU System distribution."
 <guix-devel.gnu.org>
List-Unsubscribe: <https://lists.gnu.org/mailman/options/guix-devel>,
 <mailto:guix-devel-request@gnu.org?subject=unsubscribe>
List-Archive: <https://lists.gnu.org/archive/html/guix-devel>
List-Post: <mailto:guix-devel@gnu.org>
List-Help: <mailto:guix-devel-request@gnu.org?subject=help>
List-Subscribe: <https://lists.gnu.org/mailman/listinfo/guix-devel>,
 <mailto:guix-devel-request@gnu.org?subject=subscribe>
Errors-To: guix-devel-bounces+gcggd-guix-devel=m.gmane-mx.org@gnu.org
Sender: "Guix-devel"
 <guix-devel-bounces+gcggd-guix-devel=m.gmane-mx.org@gnu.org>
To: Pierre Neidhardt <mail@ambrevar.xyz>
Cc: guix-devel@gnu.org

--=-=-=
Content-Type: text/plain

Pierre Neidhardt <mail@ambrevar.xyz> writes:

> Any thought on this, anyone?

Having used Gentoo for some years, I'm not sure a "global" parameter
system is desirable.  It could encourage enabling feature "foo", even
for packages that have experimental or broken support for "foo".

But I see how it could be useful to parameterize packages nevertheless.
I imagine adding a 'parameters' field to the package type, and write
definitions along these lines.

(package
  (parameters
   '((pulseaudio . #t)))
  (arguments
   `(#:configure-flags ,(match parameters
                         ((('pulseaudio . #t)
                          '("--enable-pulseaudio" "--enable-dbus"))
                         (_ '()))))
  (inputs
   `(("foo" ,foo)
     ,@(match parameters
         ((('pulseaudio . #t)
           `(("pulseaudio" ,pulseaudio))))
         (_ '()))))))

And perhaps a "with-parameters" procedure for toggling it:

(inputs
  `(("foo" ,foo))
    ("bar" ,(with-parameters ((pulseaudio . #f)) bar)))

We could have a similar procedure that recursively toggles supported
parameters of all given packages.

Actually we can abuse the 'properties' field for this purpose without
having to change anything.

Well, food for thought, thanks for driving this :-)

--=-=-=
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----

iQEzBAEBCgAdFiEEu7At3yzq9qgNHeZDoqBt8qM6VPoFAl4Xs6sACgkQoqBt8qM6
VPqp0Qf/ctIRfJew/6OgHvQhRGIYk9IpF1YRYhTaL0m8w9WLcsuu54flVc6gm/f7
B3keoBSuXSae1SsA+NTTHUyeg0sas3XEWqUhe/KNNCc+ziUTFvs+XaFGXV4bkYPB
1eUJZ95dUI8G6D+xtPpVVuoxit7PPsQ2/bXqh2HkGRNXFLiZSutF3PehGauNTUZ5
98+Elz6iTsrIhHB+zi3Di3lvuKfvehbXLZs03IbyWLzTBh9T4bo8tXxEJSMfEnp9
wNGV+C2Ov2MXd7rSF5RzkAYIpl6I9mi8054xYoprjcYKFoqY9zSF2E3Wka55jg+y
8HKSgS+UNcP7yfiiFNutdVP/3eahUg==
=5yag
-----END PGP SIGNATURE-----
--=-=-=--