From mboxrd@z Thu Jan  1 00:00:00 1970
From: ludo@gnu.org (Ludovic =?utf-8?Q?Court=C3=A8s?=)
Subject: Re: Proposal: auto-instantiate services with a default value
Date: Sun, 21 Jan 2018 00:26:20 +0100
Message-ID: <87a7x8glib.fsf@gnu.org>
References: <87y3l7wgf5.fsf@gnu.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
Return-path: <guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org>
Received: from eggs.gnu.org ([2001:4830:134:3::10]:39913)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <ludo@gnu.org>) id 1ed2Wn-0000el-KC
	for guix-devel@gnu.org; Sat, 20 Jan 2018 18:26:26 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <ludo@gnu.org>) id 1ed2Wm-000653-Jc
	for guix-devel@gnu.org; Sat, 20 Jan 2018 18:26:25 -0500
Received: from hera.aquilenet.fr ([2a0c:e300::1]:42098)
	by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32)
	(Exim 4.71) (envelope-from <ludo@gnu.org>) id 1ed2Wm-00063g-CJ
	for guix-devel@gnu.org; Sat, 20 Jan 2018 18:26:24 -0500
Received: from localhost (localhost [127.0.0.1])
	by hera.aquilenet.fr (Postfix) with ESMTP id B7BB6109E2
	for <guix-devel@gnu.org>; Sun, 21 Jan 2018 00:26:22 +0100 (CET)
Received: from hera.aquilenet.fr ([127.0.0.1])
	by localhost (hera.aquilenet.fr [127.0.0.1]) (amavisd-new, port 10024)
	with ESMTP id xnQl_-vhRPeT for <guix-devel@gnu.org>;
	Sun, 21 Jan 2018 00:26:21 +0100 (CET)
Received: from ribbon (unknown [IPv6:2a01:e0a:1d:7270:af76:b9b:ca24:c465])
	by hera.aquilenet.fr (Postfix) with ESMTPSA id 34830109CB
	for <guix-devel@gnu.org>; Sun, 21 Jan 2018 00:26:21 +0100 (CET)
In-Reply-To: <87y3l7wgf5.fsf@gnu.org> ("Ludovic
	\=\?utf-8\?Q\?Court\=C3\=A8s\=22'\?\=
	\=\?utf-8\?Q\?s\?\= message of "Tue, 09 Jan 2018 10:05:34 +0100")
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: <http://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.org@gnu.org
Sender: "Guix-devel" <guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org>
To: Guix-devel <guix-devel@gnu.org>

Hello!

ludo@gnu.org (Ludovic Court=C3=A8s) skribis:

> We discussed some time ago the possibility to automatically instantiate
> services.  Now that service types have default value, I think it=E2=80=99=
s a
> viable approach: if a service is required, and *if* it provides a
> default value, then we can automatically instantiate it.

I=E2=80=99ve implemented this here:

  https://git.savannah.gnu.org/cgit/guix.git/commit/?id=3Dd466b1fc8221a6224=
fe7ded53a828f9c29ed9457

Feedback welcome!

Ludo=E2=80=99.