swingMusic for midi that works with partials

swing_style.ly

@@ -46,3 +46,27 @@ swing = \mark \markup {
     }
   }
 }
+
+\include "swing.ly"
+
+swingMusic =
+#(define-music-function (parser location music) (ly:music?)
+  (define (partial-duration-length m)
+    (let ((name (ly:music-property m 'name))
+          (es (ly:music-property m 'elements))
+          (e (ly:music-property m 'element)))
+      (if (pair? es)
+        (partial-duration-length (car es))
+        (if (ly:music? e)
+          (if (and (eq? name 'ContextSpeccedMusic) (eq? (ly:music-property e 'name) 'PartialSet))
+            (ly:duration-length (ly:music-property e 'duration))
+            (if (eq? name 'NoteEvent)
+              ZERO-MOMENT
+              (partial-duration-length e)
+            )
+          )
+          ZERO-MOMENT))))
+#{
+  \swing
+  \applySwingWithOffset 8 #'(2 1) #(partial-duration-length music) #music
+#})