Re: macro for \once\override

[Aaron Hill]

On 2020-08-27 1:27 pm, David Kastrup wrote:
> Werner LEMBERG <wl@gnu.org> writes:
>
> > Folks,
> >
> >
> > I wonder whether there is a possibility to have a working equivalent
> > to
> >
> >   oo = \once\override
> >
> > so that I can say
> >
> >   \oo foo.bar = #'baz   .
> >
> > It should work with LilyPond 2.18, BTW.
> >
> > A quick search in the internet didn't bring something relevant.
>
> No, and not in 2.20 either.  The best you can aim for is
>
> \oo foo.bar #'baz

Like this, I would imagine:

%%%%
\version "2.18.2"

oo =
#(define-music-function
  (parser location grob-path value)
  (list? scheme?)
  #{ \once \override $grob-path = #value #})

{ b'4 \oo NoteHead.color #red g'4 a'2 }
%%%%


-- Aaron Hill