Re: Add dead-is-alive boolean property to Hara_kiri_group_spanner (issue 6948058)

[k-ohara5a5a]

On 2012/12/15 11:40:17, dak wrote:

> I was sort of hoping that Keith would be able to make use of this

While the negative logic makes it not negligibly difficult to avoid
errors in understanding, I see no good way to use this.

If the usual method is:
"If this Staff has anything interesting to say on this line, or if his
friends in his keep-alive-together group do, then print him."

this gives an option to reverse the action
"If a Staff with the 'censor' flag set has anything interesting to say
on this line, or if his friends in his keep-alive-together group do,
then omit him."

So while this would give users a way to have a combined staff disappear
on exactly those lines when divisi staves are printed, it interferes
with the usual function of removeEmptyStaves on the combined staff.   We
would need to declare that nothing the combined staff says is ever
'interesting', so there is no longer any way to LilyPond to remove the
combined staff when the part is truly empty.

A re-arrangement in logic could give a useful option
"If a Staff with the 'alive_together_alternative' flag set has anything
interesting to say on this line, but /none/ of his (un-flagged) friends
in his keep-alive-together group do, then print him."


https://codereview.appspot.com/6948058/