Re: Making a \layout definition in Scheme

[Urs Liska]

Am 04.04.2018 um 22:31 schrieb David Kastrup:
> Urs Liska <address@hidden> writes:
>
> > Am 04.04.2018 um 19:25 schrieb David Kastrup:
> > > Urs Liska <address@hidden> writes:
> > >
> > > > OK, but now I have a follow-up question which is quite similar to my
> > > > other post from today (and I'm afraid the answer is similarly
> > > > embarrassing):
> > > >
> > > > I managed to install an editionID to a specific movement's score with
> > > > this code:
> > > >
> > > >         (ly:score-add-output-def! score
> > > >           #{
> > > >             \layout {
> > > >               \context {
> > > >                 \Score
> > > >                 #(editionID #f movement-path)
> > > >               }
> > > >             }
> > > >           #})
> > > >
> > > > which actually works when I use that "movement-path" variable to
> > > > address  in \editionMod later.
> > > >
> > > > However, I would like to be able to also write this without the
> > > > permanent switches,
> > > Permanent switches?  Huh?
> > Well, 'permanent' is of course the wrong word. What I'm (somewhat)
> > taking issue with is switching languages back and forth within one
> > expression.
> Because?

Only because it's starting to become a somewhat alien element in the 
main body of the files. So basically a cosmetic issue (which I've 
dropped in the meantime, as said in my previous post).

> > > > i.e. in pure Scheme syntax.
> > > Why?  Seriously.
> > My project library is getting more and more pure Scheme code, and
> > while sometimes I wonder if it's worth the effort it usually turns out
> > to do so, for example because things immediately become easier to
> > maintain or extend afterwards.
> How so?

    (make-kayser-score
     (make-grouped-staves 'GrandStaff
       'clarino-one 'clarino-two 'corno-one 'corno-two)
     'tympano
     (make-grouped-staves 'ChoirStaff 'soprano 'alto 'tenor 'bass)
     (make-grouped-staves 'StaffGroup
       (make-grouped-staves 'GrandStaff 'violin-one 'violin-two 'viola)
       'bc))))

(https://git.openlilylib.org/bfsc/kayser/blob/master/includes/lib/make-score.ily#L57)
is the result of the LilyPond=>Scheme condensation process. It still 
"features" a hard-coded score structure which is not an issue in the 
current project but which I want to replace with a parametric and 
template based infrastructure to produce scores. This code is a much 
better starting point for this than the original "LilyPond" version in 
https://git.openlilylib.org/bfsc/kayser/blob/5edb9fb11d1f462c19864614d75d9b9d3665e61b/includes/lib/make-score.ily