> It wasn't the first time I had to resort to cracking open a complete
> stencil delivered by LilyPond's core engine (the last time, IIRC,
> was about coloring the elements of a key signature independently
> from one another). If such a stencil comes from a part of LilyPond
> that is already written in Scheme, then it's easy to implement any
> desired change by copying the relevant Scheme code into a .ly file
> and change it at will. If it's written in C++, that would require
> re-creating the relevant portion of LilyPond in Scheme (whicth can
> usually be done and might in some cases even be desirable to do).
> But if the latter is not an option, I think we would need a flexible
> infrastructure for manipulating stencil expressions. It shouldn't
> be too hard to implement something like a stencil-expr-map analogous
> to music-map, so a routine like the one I proposed might be
> implemented in a much more elegant and robust manner than the
> pressed-for-time hack I did yesterday can hope to be.
This might be worth an issue in our tracker tagged as 'enhancement'...
Werner
