Improve mailman analysis.

src/mailman.scm

@@ -29,13 +29,27 @@
  mailman
  (
   *mailman-bin*
+
   list-mailman-lists
   list-mailman-list-members
   load-mailman-list
   load-mailman-lists
+  
   find-mailman-list
+  
   mailman-list-name
   mailman-list-members
+  
+  email-in-mailman-list?
+  
+  add-email-to-mailman-list
+  remove-email-from-mailman-list
+  
+  mailman-ensure-member
+  mailman-ensure-not-member
+  
+  mailman-compare-members
+  
   mailman-sync-members
   )
 
@@ -153,20 +167,24 @@
    (when (email-in-mailman-list? ml email)
      (remove-email-from-mailman-list (mailman-list-name ml) email)))
 
+ ;; Returns two values - missing members and surplus list members
+ (define (mailman-compare-members ml emails)
+   (let* ((mlemails (list->lset (mailman-list-members ml)))
+	  (emails (list->lset emails))
+	  (surplus (lset-subtract mlemails emails))
+	  (missing (lset-subtract emails mlemails)))
+     (values missing surplus)))
+
  ;; Ensures given ML subscribers are exactly what is in emails list
  (define (mailman-sync-members ml emails)
-   ;; Ensure all emails in ml
-   (let loop ((emails emails))
-     (when (not (null? emails))
-       (let ((email (car emails)))
-	 (mailman-ensure-member ml email)
-	 (loop (cdr emails)))))
-   ;; Go through all emails in ml and remove all not in emails list
-   (let loop ((ml-emails (mailman-list-members ml)))
-     (when (not (null? ml-emails))
-       (let ((email (car ml-emails)))
-	 (when (not (member email emails))
-	   (mailman-ensure-not-member ml email))
-	 (loop (cdr ml-emails))))))
+   (define-values (missing surplus)
+     (mailman-compare-members ml emails))
+   (define listname (mailman-list-name ml))
+   (let loop ((emails missing))
+     (add-emails-to-mailman-list listname (car emails))
+     (loop (cdr emails)))
+   (let loop ((emails surplus))
+     (remove-email-from-mailman-list listname (car emails))
+     (loop (cdr loop))))
 
  )