Re: Should \partial accept music instead of duration?

[Thomas Morley]

Am So., 20. März 2022 um 00:02 Uhr schrieb Aaron Hill
<lilypond@hillvisions.com>:
>
> Here would be a possible refactoring:
>
> %%%%
> \version "2.22.0"
>
> partial =
> #(define-music-function (mus) (ly:music?)
>    (_i "Make a partial measure.")
>    (let* ((mom (ly:music-length mus))
>           (dur (make-duration-of-length mom)))
>      (make-music 'SequentialMusic
>        'elements
>        (list (context-spec-music
>                (make-music 'PartialSet
>                            'origin (*location*)
>                            'duration dur)
>                'Timing)
>          mus))))
>
>
> \fixed c' {
>    \time 3/4
>    \partial { g8 a4 }
>    | g2. \bar "||"
>    \partial { \grace { g16 } a8 b }
>    | a2. \bar "||"
>    \partial \tuplet 3/2 { g8 fis }
>    | g2. \bar "|."
> }
> %%%%
>
> A convert-ly rule would probably not be possible given the limited power
> of regular expressions.  As such, \partial might need to support both
> duration and music arguments.  Initially I thought this might not be
> possible, given that a naked duration can be treated as music; but the
> following does seem to work:
>
> %%%%
> \version "2.22.0"
>
> #(define (duration-or-music? arg)
>    (or (ly:duration? arg) (ly:music? arg)))
>
> partial =
> #(define-music-function (arg) (duration-or-music?)
>    (_i "Make a partial measure.")
>    (if (ly:duration? arg)
>      (context-spec-music
>        (make-music 'PartialSet
>                    'origin (*location*)
>                    'duration arg)
>        'Timing)
>      (let* ((mom (ly:music-length arg))
>             (dur (make-duration-of-length mom)))
>        (make-music 'SequentialMusic
>          'elements
>          (list (context-spec-music
>                  (make-music 'PartialSet
>                              'origin (*location*)
>                              'duration dur)
>                  'Timing)
>            arg)))))
>
>
> \fixed c' {
>    \time 3/4
>    \partial 4. g8 a4 %% Original syntax works.
>    | g2. \bar "||"
>    \partial { \grace { g16 } a8 b }
>    | a2. \bar "||"
>    \partial \tuplet 3/2 { g8 fis }
>    | g2. \bar "|."
> }
> %%%%
>
>
> -- Aaron Hill

Hi Aaron,

I really like it! Always wondered why we need to specify a duration,
if it can be taken from the music.
I'd suggest to propose it on devel. Preferable the second coding,
because we could nicely deprecate the old syntax for some versions.

Thanks,
  Harm