rework stanza handler

private_includes/base/basic_format_and_style_settings.ily

@@ -134,18 +134,23 @@ override-stanza =
 #}
 )
 
+#(define (handle-stanza-numbers context numbers number-formater)
+  (let* ((stanzanumbers (ly:assoc-get 'custom-stanzanumber-override (ly:assoc-get 'details (ly:context-grob-definition context 'StanzaNumber) '()) numbers))
+         (stanza-style (ly:assoc-get 'style (ly:context-grob-definition context 'StanzaNumber)))
+         (roman-format (lambda (stanzanumber) (format #f "~@r" stanzanumber))))
+      (ly:context-set-property! context 'stanza
+        (number-formater
+          (if (eq? stanza-style 'roman)
+              (map roman-format stanzanumbers)
+              stanzanumbers)))))
+
 #(define (stanza . stanzanumbers)
 #{
   \once \override StanzaNumber.details.custom-realstanza = ##t % set this to signal that there is a real stanza and no repeat signs
   \applyContext
   #(lambda (context)
-    (let* ((stanzanumbers-override (ly:assoc-get 'custom-stanzanumber-override (ly:assoc-get 'details (ly:context-grob-definition context 'StanzaNumber) '()) #f))
-           (stanza-style (ly:assoc-get 'style (ly:context-grob-definition context 'StanzaNumber)))
-           (stanza-format (lambda (stanzanumber) (format #f (if (eq? stanza-style 'roman) romanStanzaFormat stanzaFormat) stanzanumber))))
-        (ly:context-set-property! context 'stanza
-          (string-join (map stanza-format
-                            (if stanzanumbers-override stanzanumbers-override stanzanumbers))
-                        ", "))))
+    (handle-stanza-numbers context stanzanumbers
+      (lambda (numbers) (string-join (map (lambda (n) (format #f stanzaFormat n)) numbers) ", "))))
 #}
 )
 
@@ -153,7 +158,14 @@ ref =
 #(define-music-function (stanzanumbers lyrics) ((number-list? (list)) ly:music?)
 #{ \lyricmode {
     \once \override StanzaNumber.details.custom-realstanza = ##t % set this to signal that there is a real stanza and no repeat signs
-    \set stanza = #(make-on-the-fly-markup (lambda (layout props m) ((ly:output-def-lookup layout 'refMarkupFormatter) layout props stanzanumbers)) (make-null-markup))
+    \applyContext
+    #(lambda (context)
+      (handle-stanza-numbers context stanzanumbers
+        (lambda (numbers)
+          (make-on-the-fly-markup
+            (lambda (layout props m)
+              ((ly:output-def-lookup layout 'refMarkupFormatter) layout props numbers))
+            (make-null-markup)))))
     #lyrics
   }
 #}

private_includes/base/default_style.ily

@@ -16,7 +16,6 @@ songTocColumns = 3
 globalSize = 15
 lyricSize = 1.6
 stanzaFormat = "~a."
-romanStanzaFormat = "~@r."
 refString = "Ref.:"
 refStringWithNumbers = "Ref. ~a:"
 % hübsche Wiederholungszeichen für den Liedtext