Re: Passing arguments to grob-transformer

[Jean Abou Samra]

Le 18/06/2022 à 00:24, Leo Correia de Verdier a écrit :
> Dear list!
> I’m quite likely just being somewhat dim, but is there a way to pass additional 
> arguments to a function used by grob-transformer (or any callback for that 
> matter)?
>   Would it be possible to do something equivalent to this following using an 
> override to the stencil using grob-transformer?
>
> \version "2.23.7"
>
> #(define elongate (lambda (grob amt)
>                      (let ((stil (ly:grob-property grob 'stencil)))
>                        (ly:grob-set-property! grob 'stencil (ly:stencil-scale 
> stil 1 amt)))))
>
> {  \override Accidental.before-line-breaking = #(lambda (grob) (elongate grob 
> 2))
>     cis'2 }
>
> Thanks!
> /Leo



Like this?

\version "2.23.9"

#(define (elongate amt)
   (grob-transformer
    'stencil
    (lambda (grob original)
      (ly:stencil-scale original 1 amt))))

{  \override Accidental.stencil = #(elongate 2)
   cis'2 }


You might want to read this part of the Guile manual:

https://www.gnu.org/software/guile/manual/html_node/About-Closure.html#About-Closure

Best,
Jean