Re: Apply event function *within* music-function

[Urs Liska]

Hi Jan-Peter


Am 02.05.2017 um 11:10 schrieb Jan-Peter Voigt:
> Hi Urs,
>
> Am 02.05.2017 um 10:53 schrieb Urs Liska:
> > ...
>> What I did *not* manage yet is at the end of the thing.
>> When I use
>>
>> test =
>> #(define-music-function (mus)(ly:music?)
>>    #{
>>      <>\startGroup
>>      #mus
>>      <>\stopGroup
>>    #})
>>
>> {
>>   \test { c' d' e' f' } g' a' b' c'
>> }
>>
>> the bracket includes the g' - or rather the zero-length chord
>> immediately before it.
>>
>> Do you have any suggestion how to do *this* in a convenient manner, i.e.
>> without splitting #mus into pieces and insert the \stopGroup before the
>> last element?
>
> this *is* kind of splitting the music, but just to show, where the
> closing articulation "NoteGroupingEvent" should be placed:
>
> \version "2.19.57"
>
> test =
> #(define-music-function (mus)(ly:music?)
>    (let* ((elms (ly:music-property mus 'elements))
>           ; first and last music-element ...
>           (frst (first elms)) ; TODO test for list? and ly:music?
>           (lst (last elms)) ; TODO test for list? and ly:music?
>           (fartic (ly:music-property frst 'articulations '())) ; look
> for eventchords ...
>           (lartic (ly:music-property lst 'articulations '()))
>           )
>      (ly:music-set-property! frst 'articulations `(,@fartic
> ,(make-music 'NoteGroupingEvent 'span-direction -1)))
>      (ly:music-set-property! lst 'articulations `(,@lartic
> ,(make-music 'NoteGroupingEvent 'span-direction 1)))
>    #{
>      #mus
>    #}))
>
> \new Staff \with {
>   \consists "Horizontal_bracket_engraver"
> } {
>   \test { c' d' e' f' } g' a' b' c''
> }
>
>
> HTH

Yes, it does. I don't think there's an even more straightforward
solution (like the <> for the first element) to this. I successfully
integrated it into my code.
But what would be the cases where the element is a list? instead of
ly:music? And what does the "eventchords" comment refer to?

Best
Urs
> Jan-Peter
>
>
> _______________________________________________
> lilypond-user mailing list
> address@hidden
> https://lists.gnu.org/mailman/listinfo/lilypond-user

-- 
address@hidden
https://openlilylib.org
http://lilypondblog.org