+
+// This is likely what ly:duration-factor should have been in the
+// first place.
+LY_DEFINE (ly_duration_scale, "ly:duration-scale",
+ 1, 0, 0, (SCM dur),
+ "Extract the compression factor from @var{dur}."
+ " Return it as a rational.")
+{
+ LY_ASSERT_SMOB (Duration, dur, 1);
+ Rational r = unsmob_duration (dur)->factor ();
+
+ return ly_rational2scm (r);
+}