services: Support DELETE in MODIFY-SERVICES macro.

* gnu/services.scm (%modify-service): Add clause for DELETE syntax.
(modify-services): Use FILTER-MAP; adjust docstring.
* doc/guix.texi (System Services): Mention alternative syntax.
(X Window): Use MODIFY-SERVICES syntax.
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Ricardo Wurmus 2020-05-10 23:29:38 +02:00
parent c1ed3b048d
commit a247f5c753
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2 changed files with 29 additions and 11 deletions

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@ -13518,6 +13518,14 @@ following expression returns a list that contains all the services in
%desktop-services)
@end lisp
Alternatively, the @code{modify-services} macro can be used:
@lisp
(modify-services %desktop-services
(delete avahi-service-type))
@end lisp
@unnumberedsubsec Instantiating the System
Assuming the @code{operating-system} declaration
@ -17787,9 +17795,8 @@ and tty8.
(service slim-service-type (slim-configuration
(display ":1")
(vt "vt8")))
(remove (lambda (service)
(eq? (service-kind service) gdm-service-type))
%desktop-services))))
(modify-services %desktop-services
(delete gdm-service-type)))))
@end lisp
@end defvr

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@ -2,6 +2,7 @@
;;; Copyright © 2015, 2016, 2017, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2016 Chris Marusich <cmmarusich@gmail.com>
;;; Copyright © 2020 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
;;; Copyright © 2020, 2021 Ricardo Wurmus <rekado@elephly.net>
;;;
;;; This file is part of GNU Guix.
;;;
@ -109,7 +110,11 @@ (define-module (gnu services)
%boot-service
%activation-service
etc-service))
etc-service)
#:re-export (;; Note: Re-export 'delete' to allow for proper syntax matching
;; in 'modify-services' forms. See
;; <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=26805#16>.
delete))
;;; Comment:
;;;
@ -279,7 +284,11 @@ (define (simple-service name target value)
(service type value)))
(define-syntax %modify-service
(syntax-rules (=>)
(syntax-rules (=> delete)
((_ svc (delete kind) clauses ...)
(if (eq? (service-kind svc) kind)
#f
(%modify-service svc clauses ...)))
((_ service)
service)
((_ svc (kind param => exp ...) clauses ...)
@ -309,14 +318,16 @@ (define-syntax modify-services
(mingetty-service-type config =>
(mingetty-configuration
(inherit config)
(motd (plain-file \"motd\" \"Hi there!\")))))
(motd (plain-file \"motd\" \"Hi there!\"))))
(delete udev-service-type))
It changes the configuration of the GUIX-SERVICE-TYPE instance, and that of
all the MINGETTY-SERVICE-TYPE instances.
all the MINGETTY-SERVICE-TYPE instances, and it deletes instances of the
UDEV-SERVICE-TYPE.
This is a shorthand for (map (lambda (svc) ...) %base-services)."
This is a shorthand for (filter-map (lambda (svc) ...) %base-services)."
((_ services clauses ...)
(map (lambda (service)
(filter-map (lambda (service)
(%modify-service service clauses ...))
services))))