Re: Adding durations (for \after)

[Joel C. Salomon]

On 11/11/22 08:33, Jean Abou Samra wrote:
> Le 11/11/2022 à 03:37, David Kastrup a écrit :
> > I think we should avoid piling on arbitrary stuff without clear need for
> > expressing music into the LilyPond grammar.
>
> Personally, I find it striking that the *only* two LilyPond
> libraries I am hearing about regularly on mailing lists,
> edition-engraver and arranger.ly, are both about
> inserting / replacing music in a score at a certain
> point in time, although with different purposes
> (tweaking vs. arranging) and with different authors,
> implementations and users. To me, that means it would
> be good to integrate generic tools inspired by them
> into LilyPond proper. Now, in both of these, you
> specify a position by its timing at every fragment
> of music you insert, so this sort of syntax would make
> them quite more convenient to use.

But if that can be done from a Scheme function, it’s probably 
sufficient; no need to tamper with Lilypond grammar.

To use Lucas’s example:

> r8 es2.-8 f2 ges8~
> 8 as2.-8 8

can

    r8 es \duration_subtract{2.}{8} f2 …

be made to work?  (With whatever syntax.)

Similarly, I have music that would benefit from:

    dyn_part = {
      % \p at start, \f at third bar, \p at second-to last bar
      <>\p
      \after 1*2 \f
      \after \duration_subtract {\skip \mus_part} {1*2} \p
      \skip \mus_part
    }

I think I’ll go look up arranger.ly and see whether I can adapt something.

--Joel