Re: reading properties

[Han-Wen Nienhuys]

address@hidden writes:
> > then what you want could be done using
> > 
> >      \context Staff
> >         \applycontext #(lambda (trans)
> >               (ly-set-trans-property trans centralCPosition
> >                (+ (ly-get-trans-property trans centralCPosition) 7)))
> > 
> > We could even use this mechanism as a basic way to express various
> > other operations, such as barchecks, \property, staff changes,
> > etc. Implementing it shouldn't be that hard. Basically, you have to
> > implement a new music-iterator that does the gh_call ().  Loads of fun
> > if you've never written such a beast before :-)
> 
> I'll have a look at the end of the semester - i.e. in start of july.
> One question though: If one does
> 
> \context Voice {
>   \context Staff {
>      ..
> 
> I am pretty sure that the current translator will be Voice and not
> Staff...? This is a problem in this case (the ottava statement would
> apply to the voice and not the Staff).

It depends on the precise contents of ... ; the moment lily encounters
a note, the context of the inner { } will be switched to Thread. The
\context Staff will never descend, so the outer { } will also not
descend.

It's a little hairy, but \applycontext will simply work just as
\outputproperty does.

BTW, I might hack it in myself if I'd have to wait till July :-)

(It should be a quite small hack, at least for those in the know :-)


-- 

Han-Wen Nienhuys   |   address@hidden    | http://www.cs.uu.nl/~hanwen/