From mboxrd@z Thu Jan  1 00:00:00 1970
From: ludo@gnu.org (Ludovic =?utf-8?Q?Court=C3=A8s?=)
Subject: Re: removing items from %desktop-services
Date: Thu, 17 May 2018 16:28:18 +0200
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References: <20180516084452.GB1239@macbook41>
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In-Reply-To: <20180516084452.GB1239@macbook41> (Efraim Flashner's message of
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To: Efraim Flashner <efraim@flashner.co.il>
Cc: help-guix@gnu.org

Hello,

Efraim Flashner <efraim@flashner.co.il> skribis:

> I'm trying to modify the list of services in my os-config, and I've run
> into a bit of a problem. I've replaced my ntp-service with an
> openntpd-service, but I'm having trouble with the syntax for removing
> more services. Here's a snippet:

There=E2=80=99s an example of that in the manual (info "(guix) Using the
Configuration System"):

     (remove (lambda (service)
               (eq? (service-kind service) avahi-service-type))
             %desktop-services)

I suppose you could do the same for ntpd.

Now it=E2=80=99s a bit more verbose.  In the snippets you posted you used
=E2=80=98delete=E2=80=99, but that=E2=80=99ll only work if the service you =
want to remove has
the default configuration (and assuming it can be usefully compared with
=E2=80=98equal?=E2=80=99), so the more verbose =E2=80=98remove=E2=80=99 sta=
nza is needed.

Now, just like we have =E2=80=98modify-services=E2=80=99, we could have
=E2=80=98remove-services=E2=80=99 or similar, like this:

  (define (remove-services types services)
    (remove (lambda (service)
              (any (lambda (type)
                     (eq? (service-kind service) type))
                   types))
            services))

and then you could write:

  ;; Remove NTP and Avahi.
  (remove-services (list avahi-service-type ntp-service-type)
                   %desktop-services)

HTH!

Ludo=E2=80=99.