Re: [Lilypond-auto] Issue 1316 in lilypond: Enhancement: improved << \\ >> polyphonic shortcut notation

[lilypond]

Comment #5 on issue 1316 by address@hidden: Enhancement: improved << \\ >>  
polyphonic shortcut notation
http://code.google.com/p/lilypond/issues/detail?id=1316

Ok, here is another take on it: a true SubVoice context would not really  
work since it would have to be a child of its Voice, and Voice needs to be  
a Bottom context.  But we could take a Voice context (like now) that  
registers its parent Voice somewhere.  Now we start this with
\context Voice = "1" \with { parentVoice = ???  \consists  
Subvoice_translator }
Subvoice_translator copies over all relevant data from the parentVoice at  
its start.  It also listens for several spanning events.  If it hears an  
ending spanner event of a kind before hearing the respective start span  
event, it forwards it to the parentVoice and then goes dormant.  In a  
similar vein, if it has heard a start spanner event without a matching end  
spanner event until the end of the subvoice life span, it hands it off to  
the parentVoice (that means that at the end of the subvoices' life span,  
those spurious start events need to get sorted in time order, and then  
iterated in the parenting context at the correct moments of time).

Well, carrying over the trailing start spanner events might be tricky.   
Perhaps a manual solution where one explicitly states \outer before events  
intended to match with an event in the parentVoice context is easier than  
an automated approach.