Hi Jean, Yes I’m still pretty much a Scheme beginner even though I have been trying to learn. My first language is Python.
Thanks for the advice about not destroying the other details values. No, there is no special reason to read from the notehead, except that I don’t know how to read the value by setting the voice follower. How would I reference that property in that location? Do you mean I should remove the commented line entirely? I don’t seem to read the value when I set \once \override Staff.VoiceFollower.details.used-proportion = 0.5. I’m sorry I think I haven’t understood your suggestion. best, greg On Sat, Jul 15, 2023 at 1:25 PM Jean Abou Samra <j...@abou-samra.fr> wrote: > Hi, > > (ly:grob-set-property! follower 'details '((used-proportion > . 0.5))) ;;; HERE I would like to have user-input instead of 0.5 > ;; would prefer the above line to read something like: > ;; (ly:grob-set-property! follower 'details > '((used-proportion . (assoc-get 'used-proportion (ly:grob-property elt > 'details '()))))) > )))) > > > The outcommented line sounds like you are confused about quoting, which is > pretty common for Scheme beginners. > > You probably want to read about it more in detail, for example on > https://extending-lilypond.gitlab.io/en/scheme/quoting.html > > > With that being said, what is the purpose of copying 'used-proportion from > a note head to a voice follower, can't you read and set it on the voice > follower directly? > > Also, beware of doing (ly:grob-set-property! follower 'details ...) since > that will destroy all other entries that might be in the details alist. > Better do > > (ly:grob-set-nested-property! follower '(details used-proportion) ...) > > to update only the used-proportion entry while keeping the others intact. > > Best, > Jean > > -- gregory rowland evans http://www.gregoryrowlandevans.com https://github.com/GregoryREvans https://soundcloud.com/gregory-rowland-evans
