@@ -23,10 +23,20 @@
 
 (define (args:get-arg arg . default)
   (if (null? default)
       (hash-table-ref/default args:arg-hash arg #f)
       (hash-table-ref/default args:arg-hash arg (car default))))
+
+;; get an arg as a number
+(define (args:get-arg-number arg . default)
+  (let* ((val-str (args:get-arg arg))
+	 (val     (if val-str (string->number val-str) #f)))
+    (if val
+	val
+	(if (null? default)
+	    #f
+	    default))))
 
 (define (args:any? . args)
   (not (null? (filter (lambda (x) x)
 		      (map args:get-arg args)))))