\version "2.19.22"

%% defined later, in a closure
#(define-public (add-toc-item! markup-symbol text)
  #f)
#(define-public (toc-items)
  #f)

#(let ((toc-item-list (list)))
   (call-after-session (lambda () (set! toc-item-list '())))
   (set! add-toc-item!
         (lambda (markup-symbol text)
           (let ((label (gensym "toc")))
             (set! toc-item-list
                   (cons (list label markup-symbol text)
                         toc-item-list))
             (make-music 'EventChord
               'page-marker #t
               'page-label label
               'elements (list (make-music 'LabelEvent
                                 'page-label label))))))
   (set! toc-items (lambda ()
                     (reverse toc-item-list))))

\paper {
  tocTitleMarkup = \markup \huge \column {
    \fill-line { \null "Table of Contents" \null }
    \null
  }
  tocItemMarkup = \markup \fill-line {
    \fromproperty #'toc:text \fromproperty #'toc:page
  }
}

tocItemWithDotsMarkup = \markup \fill-with-pattern #1 #RIGHT .
  \fromproperty #'toc:text \fromproperty #'toc:page

#(define-markup-list-command (table-of-contents layout props) ()
  ( _i "Outputs the table of contents, using the paper variable
@code{tocTitleMarkup} for its title, then the list of lines
built using the @code{tocItem} music function
Usage: @code{\\markuplist \\table-of-contents}" )
  (cons (interpret-markup layout props
                          (ly:output-def-lookup layout 'tocTitleMarkup))
        (space-lines (chain-assoc-get 'baseline-skip props)
                    (map (lambda (toc-item)
                           (let ((label (car toc-item))
                                 (toc-markup (cadr toc-item))
                                 (text (caddr toc-item)))
                             (interpret-markup
                               layout
                               (cons (list (cons 'toc:page
                                            (markup #:with-link label #:page-ref label "XXX" "?"))
                                           (cons 'toc:text (markup #:with-link label text))
                                           (cons 'toc:label label))
                                     props)
                               (ly:output-def-lookup layout toc-markup))))
                         (toc-items)))))

tocItem =
#(define-music-function (text) (markup?)
   "Add a line to the table of content, using the @code{tocItemMarkup} paper
variable markup"
   (add-toc-item! 'tocItemMarkup text))