Give display-lily-music and display-music optional port arguments.

diff --git a/scm/music-functions.scm b/scm/music-functions.scm
index e007e6412f87c01d44b217b798a590830a4feccc..80de207c695825fe8b8184a611b2ff32bf3ccc14 100644 (file)
--- a/scm/music-functions.scm
+++ b/scm/music-functions.scm
@@ -19,7 +19,7 @@
 ; for define-safe-public when byte-compiling using Guile V2
 (use-modules (scm safe-utility-defs))
 
-;; (use-modules (ice-9 optargs))
+(use-modules (ice-9 optargs))
 
 ;;; ly:music-property with setter
 ;;; (ly:music-property my-music 'elements)
@@ -98,24 +98,23 @@ First it recurses over the children, then the function is applied to
       music
       (make-music 'Music)))      ;must return music.
 
-(define-public (display-music music)
+(define*-public (display-music music #:optional (port (current-output-port)))
   "Display music, not done with @code{music-map} for clarity of
 presentation."
-
-  (display music)
-  (display ": { ")
+  (display music port)
+  (display ": { " port)
   (let ((es (ly:music-property music 'elements))
        (e (ly:music-property music 'element)))
-    (display (ly:music-mutable-properties music))
+    (display (ly:music-mutable-properties music) port)
     (if (pair? es)
-       (begin (display "\nElements: {\n")
-              (map display-music es)
-              (display "}\n")))
+       (begin (display "\nElements: {\n" port)
+              (for-each (lambda (m) (display-music m port)) es)
+              (display "}\n" port)))
     (if (ly:music? e)
        (begin
-         (display "\nChild:")
-         (display-music e))))
-  (display " }\n")
+         (display "\nChild:" port)
+         (display-music e port))))
+  (display " }\n" port)
   music)
 
 ;;;
@@ -216,14 +215,15 @@ which often can be read back in order to generate an equivalent expression."
 (use-modules (srfi srfi-39)
              (scm display-lily))
 
-(define*-public (display-lily-music expr parser #:key force-duration)
+(define*-public (display-lily-music expr parser #:optional (port (current-output-port))
+                                   #:key force-duration)
   "Display the music expression using LilyPond syntax"
   (memoize-clef-names supported-clefs)
   (parameterize ((*indent* 0)
                 (*previous-duration* (ly:make-duration 2))
                 (*force-duration* force-duration))
-    (display (music->lily-string expr parser))
-    (newline)))
+    (display (music->lily-string expr parser) port)
+    (newline port)))
 
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