Factor out with-mbase-progress.

src/mbase.scm

@@ -58,6 +58,9 @@
   mbase-active-emails
 
   mbase-merge-mailman
+
+  do-with-mbase-progress%
+  with-mbase-progress%
   )
 
  (import scheme
@@ -288,4 +291,29 @@
 	    mb
 	    emails)))
 
+ ;; Iteration with progress over all members
+ (define (do-with-mbase-progress% mb name proc)
+   (let* ((members-list (find-members-by-predicate mb brmember-existing?))
+	  (mlen0 (length members-list))
+	  (mlen (if (> mlen0 0)
+		    mlen0
+		    1)))
+     (with-progress%
+      #t name
+      (let loop ((mb members-list)
+		 (i 0))
+	(if (not (null? mb))
+	    (let ()
+	      (progress%-advance (/ i mlen))
+	      (proc (car mb))
+	      (loop (cdr mb)
+		    (add1 i))))
+	(progress%-advance 1)))))
+
+ ;; Simple syntax wrapper
+ (define-syntax with-mbase-progress%
+   (syntax-rules ()
+     ((_ mb name mr body ...)
+      (do-with-mbase-progress% mb name (lambda (mr) body ...)))))
+
  )