Thank you David for your help.
I made some tests with \displayMusic and I have seen the situation :)
Thank you Aaron for the detailed explanation and also for the other code!
I will continue to use your \extract code but I keep also the new one for
the future :)
Have a nice w/e.
Ciao, g
On Sat, 24 Apr 2021 at 11:40, Aaron Hill <lilyp...@hillvisions.com> wrote:
> On 2021-04-23 11:32 pm, David Kastrup wrote:
> > Gianmaria Lari <gianmarial...@gmail.com> writes:
> >
> >> Thank you Aaron and Jean, your code works!
> >>
> >> But I have some trivial questions.
> >> If I write:
> >>
> >> \displayLilyMusic \chordmode {c}
> >>
> >>
> >> I get:
> >>
> >> { < c' e' g' >4 }
> >>
> >>
> >> It looks a good "compound music expression".
> >
> > Try \displayMusic rather than \displayLilyMusic for more details.
>
> In case David's hint was not sufficient, there is an additional layer of
> complexity when using \chordmode. Unfortunately, that layer is not
> visible when using \displayLilyMusic, and this is where the confusion
> arises.
>
> \chordmode produces UnrelativableMusic that contains SequentialMusic and
> then EventChords of NoteEvents.
>
> Jean's first-element assumes that the music argument has a property
> called elements and resolves to the first value within the collection.
> UnrelativableMusic only has an element property, so first-element gets
> stuck. Here is a modified version of first-element that does not:
>
> %%%%
> #(define (first-element music)
> (or (ly:music-property music 'element #f)
> (first (ly:music-property music 'elements))))
>
> % This works, but you get a SequentialMusic.
> { #(first-element #{ \chordmode {c} #}) }
>
> % This grabs the EventChord from the SequentialMusic.
> { #(first-element (first-element #{ \chordmode {c} #})) }
> %%%%
>
> My \extract uses the built-in extract-typed-music procedure to do the
> heavy lifting, including the logic necessary to traverse nested music
> expressions with both element and elements properties.
>
>
> -- Aaron Hill
>
