Hi, currently
\displayLilyMusic { c4 c c c } produces output { c4 c c c }. I lean
towards letting it produce output { c4 c4 c4 c4 }. Reason: that's
what's actually in the data structures of the music. The machinery that
tries to decide when it can leave off the default duration is
potentially error-prone and carries state across the expression.
More seriously, currently \displayLilyMusic deals badly with
{ c4 c4 8 8 4 } which gets rendered as { c4 c 8 8 4 } and does
consequently not recreate its input. It would be rather tricky to fix
that since by the time the 8 is printed, c and the following space have
already been produced. Instead of making things even more complex here,
I consider it saner to become less clever and just print what's in the
data, never mind whether it's possibly redundant.
Opinions?