[shepherd] 02/05: service: Rewrite 'conflicts-with' in functional style.

[Ludovic Courtès]

civodul pushed a commit to branch master
in repository shepherd.

commit cb168150d4581ffbc357ab6cdcd45d59051ee821
Author: Ludovic Courtès <address@hidden>
Date:   Mon Jan 18 21:41:09 2016 +0100

    service: Rewrite 'conflicts-with' in functional style.
    
    * modules/shepherd/service.scm (conflicts-with): Rewrite using
    'append-map' and 'filter-map'.
    (conflicts-with-running): Rewrite in terms of 'conflicts-with'.
---
 modules/shepherd/service.scm |   31 +++++++++----------------------
 1 files changed, 9 insertions(+), 22 deletions(-)

diff --git a/modules/shepherd/service.scm b/modules/shepherd/service.scm
index 56ef9a0..72fe34c 100644
--- a/modules/shepherd/service.scm
+++ b/modules/shepherd/service.scm
@@ -380,33 +380,20 @@ respawned, shows that it has been respawned more than 
TIMES in SECONDS."
 ;; Return a list of canonical names of the services that conflict with
 ;; OBJ.
 (define-method (conflicts-with (obj <service>))
-  (let ((conflicts '()))
-    (for-each (lambda (sym)
-               (for-each (lambda (s)
-                           (set! conflicts (cons (canonical-name s)
-                                                 conflicts)))
-                         (lookup-services sym)))
-             (provided-by obj))
-    ;; Clean up the result.
-    (delete! (canonical-name obj)
-            (delete-duplicates! conflicts eq?)
-            eq?)))
+  (delete-duplicates
+   (append-map (lambda (sym)
+                 (filter-map (lambda (service)
+                               (and (not (eq? service obj))
+                                    (canonical-name service)))
+                             (lookup-services sym)))
+               (provided-by obj))
+   eq?))
 
 ;; Check if this service provides a symbol that is already provided
 ;; by any other running services.  If so, return the canonical names
 ;; of the other services.  Otherwise, return the empty list.
 (define-method (conflicts-with-running (obj <service>))
-  (let ((conflicts '()))
-    (for-each-service
-     (lambda (serv)
-       (and (running? serv)
-           (for-each (lambda (sym)
-                       (and (memq sym (provided-by obj))
-                            (set! conflicts
-                                  (cons (canonical-name serv)
-                                        conflicts))))
-                     (provided-by serv)))))
-    conflicts))
+  (filter running? (conflicts-with obj)))
 
 ;; Start OBJ, but first kill all services which conflict with it.
 ;; FIXME-CRITICAL: Conflicts of indirect dependencies.  For this, we