(spacing-wishes ,ly:grob-array? "An array of note spacing or staff spacing
objects.")
(span-start ,boolean? "Is the note head at the start of a spanner?")
+ (spanner-broken ,boolean? "Indicates whether spanner
+alignment should be broken after the current spanner.")
(spanner-placement ,ly:dir? "The place of an annotation on a spanner.
LEFT is for the first spanner, and RIGHT is for the last. CENTER will
place it on the broken spanner that falls closest to the center of the length