Re: \makeOctaves broken?

[Urs Liska]

Hi all,

thank you very much for all these thoughts.
I'm so sorry that I don't understand a (Scheme) word from it ...
But judging from my programming experience in other languages David's 
last solution looks _very_ elegant. And it seems to work, even with 
still more complex chords and multiple articulations.

I'd suggest to rename the function though, because "makeOctaves" 
suggests that it (only) makes octaves from monophonic notes.

And it may be of interest to note that the function also works with 
other values than +/- 1,
and that it can be nested:

\relative c {
  \time 3/8
  \key gis \minor
  \makeOctaves #1  { dis8( e dis')~ dis8.( cis16 b8) }
  \makeOctaves #2 { ais8. gis32_| fis^| e8^._-  }
  \makeOctaves #2 {
    \makeOctaves #-1 {
      ais'( gis-. dis-.) cis( dis<dis gis'>)
    <e g bes>  <f d'>_^^.<fis cis' gis'>_.^-
    }
  }
}

Any chance to get this incorporated to default LilyPond syntax?

Best (and many thanks)
Urs

Am 19.04.2012 09:56, schrieb David Kastrup:
> Urs Liska<address@hidden>  writes:
>
> [...]
>
> I recommend a healthy dose of cheating.  The main non-triviality seems
> to be dealing with relative music properly.  Other than that it is just
> <<  \transpose c' c'' $xxx $xxx>>  or similar.  So let's treat the
> problem at the root, with a to-relative-callback for the transposed
> music that a) returns the unchanged reference pitch for the sake of the
> following music b) temporarily undoes the octave transposition for the
> sake of relativizing.
>
> makeOctaves =
> #(define-music-function (parser location arg mus)
>    (integer? ly:music?)
>    #{<<  \withMusicProperty #'to-relative-callback
>          #(lambda (m p)
>            (let ((mu (ly:music-property m 'element)))
>             (ly:music-transpose mu (ly:make-pitch (- arg) 0 0))
>             (ly:make-music-relative! mu p)
>             (ly:music-transpose mu (ly:make-pitch arg 0 0)))
>            p)
>          \transpose c' $(ly:make-pitch arg 0 0) $mus
>          $mus
>       >>
>    #})
>
> \relative c' {
>    \time 3/8
>    \key gis \minor
>    \makeOctaves #1  { dis8( e dis')~ dis8.( cis16 b8}
>    \makeOctaves #-1 { ais' gis dis) cis( dis<dis gis'>) }
> }