Le 27/06/2022 à 20:10, Simon Albrecht a écrit :
Hello everyone,
I’m trying to encode a piece such that I can switch whether or not
durations will be shifted (note values halved/doubled). Unfortunately
\tempo isn’t affected by \shiftDurations (that would be a sensible
feature request, right?),
Go open an issue.
so I tried this:
%%%%%%%%%%%%%%%%%%%%%%%%%%%
\version "2.23.9"
durationShiftOne = #-1
{
\tempo #(ly:make-duration (+ 3 durationShiftOne)) = 152
\shiftDurations \durationShiftOne #0 { 8 }
}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
but unfortunately Lily won’t accept that Scheme expression instead of
the normal duration.
Can I make that work some other way?
Should the parser be able to take that Scheme expression there?
\version "2.23.9"
durationShiftOne = #-1
{
\tempo $(ly:make-duration (+ 3 durationShiftOne)) = 152
\shiftDurations \durationShiftOne #0 { 8 }
}
You just need to use $ instead of #. See these pages about the difference:
https://lilypond.org/doc/v2.23/Documentation/extending/lilypond-scheme-syntax.html
https://extending-lilypond.readthedocs.io/en/latest/lily-and-scheme.html#hash-vs-dollar
The problem is that \tempo has multiple syntaxes (\tempo <markup>,
\tempo <duration> = <bpm> and \tempo <markup> <duration> = <bpm>),
which makes it impossible to accept # here because early evaluation
is needed to disambiguate, I think. I'm no expert of the parser
though.
Best,
Jean
