[PATCH 10/16] Add symbol-list-or-music? predicate

[David Kastrup]

This is of interest for commands like \hide which accept either music
(to see an override) or a grob specification like Accidental or
Voice.Accidental.
---
 scm/c++.scm  |    5 +++++
 scm/lily.scm |    1 +
 2 files changed, 6 insertions(+)

diff --git a/scm/c++.scm b/scm/c++.scm
index d627481..12c38a3 100644
--- a/scm/c++.scm
+++ b/scm/c++.scm
@@ -51,6 +51,11 @@
 (define-public (symbol-list? x)
   (and (list? x) (every symbol? x)))
 
+(define-public (symbol-list-or-music? x)
+  (if (list? x)
+      (every symbol? x)
+      (ly:music? x)))
+
 (define-public (string-or-symbol? x)
   (or (string? x) (symbol? x)))
 
diff --git a/scm/lily.scm b/scm/lily.scm
index a74d6af..268fd1c 100644
--- a/scm/lily.scm
+++ b/scm/lily.scm
@@ -579,6 +579,7 @@ messages into errors.")
     (,string-or-music? . "string or music")
     (,string-or-symbol? . "string or symbol")
     (,symbol-list? . "symbol list")
+    (,symbol-list-or-music? . "symbol list or music")
     (,void? . "void")
     ))
 
-- 
1.7.9.5