\version "2.13.11"

%%%% Helper functions, which simply print out the observed rest/note events
%%%% in a nice format:
#(define (format-rest engraver event)
  (let* ((context (ly:translator-context engraver))
         (moment (ly:context-current-moment context))
         (duration (ly:event-property event 'duration)))
    ; TODO: Format the duration and the moment
    (ly:message "REST event of duration ~a at ~a\n" duration moment)
    ; or dump the whole event to see what information is available:
    ; (ly:message "REST event at ~a: ~a\n" moment event)
  )
)

#(define (format-note engraver event)
  (let* ((context (ly:translator-context engraver))
         (moment (ly:context-current-moment context))
         (duration (ly:event-property event 'duration))
         (pitch (ly:event-property event 'pitch)))
    ; TODO: Format the duration, pitch and the moment
    (ly:message "NOTE event of duration ~a, pitch ~a at ~a\n" duration pitch moment)
    ; or dump the whole event to see what information is available:
    ; (ly:message "NOTE event at ~a: ~a\n" moment event)
  )
)


%%%% The actual engraver definition: We just install some listeners so we
%%%% are notified about all notes and rests. We don't create any grobs or
%%%% change any settings.

\layout {
  \context {
    % I add this to the score, so all voices are caught. You can also only add
    % the engraver to selected voices to get the statistics split down.
    \Score
    \consists
    #(list
      (cons 'listeners
       (list
        (cons 'rest-event format-rest)
        (cons 'note-event format-note)
       ))
    )
  }
}


\relative c' {
  c8[ r c]
}