Re: \newEngraverSection (was "Re: Aleatoric Elements with barlines")

[Aaron Hill]

On 2019-01-07 9:18 am, Kieren MacMillan wrote:
> Would it be technically possible to add a \newEngraverSection —
> analogous to \newSpacingSection — which would allow a single
> contiguous score to have different engravers "active" in different
> sections?
>
> This isn’t even yet at the level of "feature request": right now, I’m
> just curious to hear an answer like "can’t happen without a total
> re-write of the entire C++ codebase" or "technically possible, but the
> interface isn’t clear" or "even though it’s dead simple to achieve,
> here’s why that’s the stupidest idea we’ve ever heard".

I might approach this by seeing if it is possible to create a "meta" 
engraver that is able to delegate to another engraver and selectively 
remain "silent" over a specified range of time.  In this way, the 
\Score-level engravers could be active except for the cadenza section.  
And the \Staff-level engravers are only active during the cadenza.

The concept seems like it could work, but I do not know the underlying 
details of LilyPond well enough to say if this is actually madness.


-- Aaron Hill