Re: conditional \when-property

[David Nalesnik]

Hi Kieren,

On Wed, Jul 31, 2013 at 5:59 PM, Kieren MacMillan <address@hidden> wrote:

Hi David,

> Using empty-stencil rather than your own call of ly:make-stencil should
> work for more versions.

This sounds useful… but I don't quite know what you are suggesting I do. Do you mean this (which appears to work, but still uses ly:make-stencil):

#(define-markup-command (when-property layout props symbol markp) (symbol? markup?)
  (if (chain-assoc-get symbol props)
      (interpret-markup layout props markp)

      (ly:make-stencil empty-stencil)))

?

I tried a lot of things without ly:make-stencil, and they all failed.

empty-stencil is defined as

(ly:make-stencil '() empty-interval empty-interval)

so the ly:make-stencil in your function is unneccesary.  All you need to do is the following:

 #(define-markup-command (when-property layout props symbol markp) (symbol? markup?)

  (if (chain-assoc-get symbol props)

      (interpret-markup layout props markp)

      empty-stencil))

--David