Hi, Ricardo Wurmus <rek...@elephly.net> skribis:
>>From 40c1208cbe9cbfa58ee385ef6ee06b775d309753 Mon Sep 17 00:00:00 2001 > From: Ricardo Wurmus <rek...@elephly.net> > Date: Sun, 10 May 2020 23:29:38 +0200 > Subject: [PATCH] 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. I like it! > - #:use-module (srfi srfi-1) > + #:use-module ((srfi srfi-1) #:hide (delete)) > #:use-module (srfi srfi-9) > #:use-module (srfi srfi-9 gnu) > #:use-module (srfi srfi-26) > @@ -272,7 +273,11 @@ singleton service type NAME, of which the returned > service is an instance." > (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 ...))) Best practice suggests that ‘delete’ should be bound (info "(guile) Syntax Rules"): --8<---------------cut here---------------start------------->8--- Although literals can be unbound, usually they are bound to allow them to be imported, exported, and renamed. *Note Modules::, for more information on imports and exports. In Guile there are a few standard auxiliary syntax definitions, as specified by R6RS and R7RS: --8<---------------cut here---------------end--------------->8--- Now, if we export a new ‘delete’ binding from here, it’ll annoy everyone. So perhaps we can keep the srfi-1 ‘delete’ and re-export it, as done in (guix build utils)… though that situation is also annoying because we get warnings saying that it collides with core ‘delete’. Dunno, give it a try! Ludo’.
