From: Maxim Cournoyer <maxim.cournoyer@gmail.com>
To: "Ludovic Courtès" <ludo@gnu.org>
Cc: 56799@debbugs.gnu.org, attila@lendvai.name
Subject: bug#56799: (gnu services configuration) usage of *unspecified* is problematic
Date: Mon, 01 Aug 2022 11:55:20 -0400 [thread overview]
Message-ID: <87les82c2f.fsf@gmail.com> (raw)
In-Reply-To: <8735egxedv.fsf@gnu.org> ("Ludovic Courtès"'s message of "Mon, 01 Aug 2022 15:49:32 +0200")
Hi Ludo,
Ludovic Courtès <ludo@gnu.org> writes:
> Hi!
>
> Maxim Cournoyer <maxim.cournoyer@gmail.com> skribis:
>
>> Since commit 8cb1a49a3998c39f315a4199b7d4a121a6d66449, the
>> define-configuration machinery in (gnu services configuration) uses
>> *unspecified* instead of 'disabled for an unspecified field value.
>
> As Attila wrote, the rationale as discussed in
> <https://issues.guix.gnu.org/54674> was to specifically use a “special”
> value without a read syntax in lieu of a symbol like 'disabled.
>
>> While this is indeed an improvement in readability, it introduces an
>> extra complication: because this new value is not self-quoting, it
>> cannot be used as is in G-Exps, and values using it must be carefully
>> expanded outside the gexp context, which is error prone.
>
> Could you give a simple example of how this can happen?
>
> In my experience, one would use ‘define-maybe’ and appropriate field
> serializers such that *unspecified* never goes through. Previously
> you’d check for (eq? x 'disabled) and now you just check for
> (unspecified? x).
Yes, I understand that. What changed is that previously you could have
the configuration serialized and used on the service side, which is what
using *unspecified* made impossible.
Granted, few services outside of Jami probably made use of this, but it
was nevertheless a useful property.
Thanks,
Maxim
next prev parent reply other threads:[~2022-08-01 16:17 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-27 16:23 bug#56799: (gnu services configuration) usage of *unspecified* is problematic Maxim Cournoyer
2022-07-27 16:43 ` Tobias Geerinckx-Rice via Bug reports for GNU Guix
2022-07-27 18:27 ` Attila Lendvai
2022-07-28 15:15 ` Maxim Cournoyer
2022-07-27 18:31 ` Maxim Cournoyer
2022-07-27 18:45 ` Tobias Geerinckx-Rice via Bug reports for GNU Guix
2022-07-27 19:09 ` Maxim Cournoyer
2022-07-27 19:45 ` bug#56799: [PATCH] services: configuration: Step back from *unspecified* Maxim Cournoyer
2022-07-27 19:46 ` bug#56799: (gnu services configuration) usage of *unspecified* is problematic Maxim Cournoyer
2022-07-27 20:20 ` bug#56799: [PATCH v2] gexp: Handle *unspecified* as a gexp input Maxim Cournoyer
2022-07-27 21:43 ` Maxime Devos
2022-07-28 14:58 ` Maxim Cournoyer
2022-07-28 4:41 ` bug#56799: [PATCH v3] " Maxim Cournoyer
2022-08-01 5:08 ` bug#56799: (gnu services configuration) usage of *unspecified* is problematic Maxim Cournoyer
2022-08-01 10:00 ` Maxime Devos
2022-08-01 12:46 ` Maxim Cournoyer
2022-08-01 13:44 ` Ludovic Courtès
2022-08-01 16:55 ` Maxim Cournoyer
2022-07-28 4:55 ` bokr
2022-07-28 10:26 ` Maxime Devos
2022-07-28 15:09 ` Maxim Cournoyer
2022-08-01 13:49 ` Ludovic Courtès
2022-08-01 15:55 ` Maxim Cournoyer [this message]
2022-08-02 7:31 ` Ludovic Courtès
2022-08-02 8:45 ` bokr
2022-08-02 15:06 ` Maxim Cournoyer
2022-08-04 12:19 ` Ludovic Courtès
2022-08-07 22:44 ` Ludovic Courtès
2022-08-08 22:27 ` Attila Lendvai
2022-08-08 23:35 ` Attila Lendvai
2022-08-10 2:17 ` Maxim Cournoyer
2022-08-10 3:26 ` Maxim Cournoyer
2022-08-11 10:15 ` Attila Lendvai
2022-08-13 6:31 ` Maxim Cournoyer
2022-08-13 16:47 ` Attila Lendvai
2022-08-14 2:57 ` Maxim Cournoyer
2022-08-16 14:00 ` Attila Lendvai
2022-08-17 13:16 ` Maxim Cournoyer
2022-08-17 16:00 ` paren--- via Bug reports for GNU Guix
2022-08-10 0:43 ` Maxim Cournoyer
2022-08-24 12:40 ` bug#56799: [PATCH 1/5] services: configuration: Add a 'maybe-value-set?' procedure Attila Lendvai
2022-08-24 12:40 ` bug#56799: [PATCH 2/5] services: configuration: Add %unset-value exported variable Attila Lendvai
2022-08-24 12:40 ` bug#56799: [PATCH 3/5] services: configuration: Add maybe-value exported procedure Attila Lendvai
2022-08-24 12:40 ` bug#56799: [PATCH 4/5] services: Use the new maybe/unset API Attila Lendvai
2022-08-25 4:18 ` bug#56799: (gnu services configuration) usage of *unspecified* is problematic Maxim Cournoyer
2022-08-24 12:40 ` bug#56799: [PATCH 5/5] services: configuration: Change the value of the unset marker Attila Lendvai
2022-08-25 4:14 ` bug#56799: (gnu services configuration) usage of *unspecified* is problematic Maxim Cournoyer
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