\version "2.14.2"

% ---------------------------------------------------

#(define my-engraver
   (let ((grobs '()))
     (list
       ;; process each note object with each saved grob
       (cons 'process-acknowledged
             (lambda (trans)
               (for-each
                 (lambda (grob)
                   (if (ly:grob? grob)
                       (let* ((stem-grob (ly:grob-object grob 'stem))
                              (direction (ly:grob-property stem-grob 'direction)))
                         (display direction)
                         ))) grobs)))

       ;; save grob for processing
       (cons 'acknowledgers
             (list
               (cons 'note-head-interface
                     (lambda (engraver grob source-engraver)
                       (set! grobs (append grobs (list grob)))))
               ))
       )))

% ---------------------------------------------------

\score {
  \new Staff {
    \clef "bass"
    \key c \major
    \new MyVoice {
      \relative f {
        %e8-4\8
        r2.. e8-4\8 ~ e
        e,8-1\7 fis-2 g16-1 g-2 a8-4 cis-1\8 d-2 e8-4
      }
    }
  }

  \layout {
    \context {
      \Voice
      \name MyVoice
      \alias Voice
      \description "A voice using my engraver"

      \remove "Fingering_engraver"
      \remove "New_fingering_engraver"
      \consists \my-engraver
    }
    \context {
      \Staff
      \accepts "MyVoice"
    }

  }
}