Scheme function with boolean argument.

[Pierre Perol-Schneider]

Hi,

I'd like to understand why the following function has no effect :

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\version "2.19.3"

myFunctionFalse = \override Score.BarNumber.break-visibility = ##(#f #f #f)

myFunctionTrue = \override Score.BarNumber.break-visibility = ##(#f #t #t)

myFunction =

#(define-music-function (parser location arg) (boolean?)

   #{

     \override Score.BarNumber.break-visibility = ##(#f $arg $arg)

   #})

{

   \myFunctionFalse

   \repeat unfold 16 c'1

   \myFunctionTrue

   \repeat unfold 16 c'1

%%% no/wrong effect here :

   \myFunction ##f

   \repeat unfold 16 c'1

   \myFunction ##t

   \repeat unfold 16 c'1

}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Cheers,

~Pierre