Hi Brian!
Brian Cully writes:
> This patch reverts the behavior introduced in
> 181951207339508789b28ba7cb914f983319920f which caused ‘modify-services’
> clauses to only match a single instance of a service.
>
> We will now match all service instances when doing a deletion or update, while
> still raising an exception when trying to match against a service that does
> not exist in the services list, or which was deleted explicitly by a ‘delete’
> clause (or an update clause that returns ‘#f’ for the service).
>
> Fixes: #64106
>
> * gnu/services.scm (%modify-services): New procedure.
> (modify-services): Use it.
> (apply-clauses): Add DELETED-SERVICES argument, change to modify one service
> at a time.
> * tests/services.scm
> ("modify-services: delete then modify"),
> ("modify-services: modify then delete"),
> ("modify-services: delete multiple services of the same type"),
> ("modify-services: modify multiple services of the same type"): New tests.
[...]
I've applied the following cosmetic changes:
--8<---cut here---start->8---
1 file changed, 20 insertions(+), 18 deletions(-)
gnu/services.scm | 38 --
modified gnu/services.scm
@@ -325,11 +325,13 @@ (define-syntax clause-alist
'(
(define (apply-clauses clauses service deleted-services)
+ "Apply CLAUSES, an alist as returned by 'clause-alist', to SERVICE. An
+exception is raised if a clause attempts to modify a service
+present in DELETED-SERVICES."
(define (raise-if-deleted kind properties)
-(match (find (lambda (deleted)
- (match deleted
- ((deleted-kind _)
- (eq? kind deleted-kind
+(match (find (match-lambda
+ ((deleted-kind _)
+(eq? kind deleted-kind)))
deleted-services)
((_ deleted-properties)
(raise (make-compound-condition
@@ -344,27 +346,27 @@ (define (apply-clauses clauses service deleted-services)
(match clauses
(((kind proc properties) . rest)
- (begin
- (raise-if-deleted kind properties)
- (if (eq? (and service (service-kind service))
-kind)
- (let ((new-service (proc service)))
- (apply-clauses rest new-service
-(if new-service
-deleted-services
-(cons (list kind properties)
- deleted-services
- (apply-clauses rest service deleted-services
+ (raise-if-deleted kind properties)
+ (if (eq? (and service (service-kind service)) kind)
+ (let ((new-service (proc service)))
+ (apply-clauses rest new-service
+ (if new-service
+ deleted-services
+ (cons (list kind properties)
+deleted-services
+ (apply-clauses rest service deleted-services)))
(()
service)))
(define (%modify-services services clauses)
+ "Apply CLAUSES, an alist as returned by 'clause-alist', to SERVICES. An
+exception is raised if a clause attempts to modify a missing service."
(define (raise-if-not-found clause)
(match clause
((kind _ properties)
- (when (not (find (lambda (service)
- (eq? kind (service-kind service)))
-services))
+ (unless (find (lambda (service)
+ (eq? kind (service-kind service)))
+ services)
(raise (make-compound-condition
(condition
(
--8<---cut here---end--->8---
and installed it. Thanks for contributing to Guix!
--
Thanks,
Maxim
