View source for PDF bookmarks without table of contents

It is a [https://gitlab.com/lilypond/lilypond/-/issues/6300 known issue] that there is no built-in way to obtain an outline in the PDF metadata without also printing a table of contents. This snippet provides a workaround.

<lilypond version="2.24">
#(define-markup-list-command (invisible-table-of-contents layout props) ()
   (interpret-markup-list layout props (make-table-of-contents-markup-list))
   (list empty-stencil))

\markuplist \invisible-table-of-contents

\tocItem \markup "Piece 1"
{ c' }

\tocItem \markup "Piece 2"
{ d' }
</lilypond>

[[Category:Workaround]]
[[Category:Snippet]]