%% http://lsr.di.unimi.it/LSR/Item?id=860

%% TODO
%% TupletBracket/Number is improved with 2.20, check whether this snippet is still needed/useful

tupletAtNoteHeads =
  \override TupletBracket.before-line-breaking =
    #(lambda (grob)
      (let* ((tuplet-dir (ly:grob-property grob 'direction))
             (note-columns 
               (ly:grob-array->list (ly:grob-object grob 'note-columns)))
             (note-heads-array-list 
               (flatten-list
                 (map 
                   (lambda (x) 
                     (ly:grob-object x 'note-heads))
                       note-columns)))
             (note-heads 
             	(flatten-list 
             	  (map 
             	    (lambda (x) 
             	      (ly:grob-array->list x)) 
             	        note-heads-array-list)))
            (stems (map (lambda (x) (ly:grob-object x 'stem)) note-heads))
            (stem-dirs (map (lambda (x) (ly:grob-property x 'direction)) stems))
            (sorted-stems-dirs-list 
              (sort-list stem-dirs (lambda (a b) (< a b))))
            (equal-stems-dir? 
              (= (car sorted-stems-dirs-list) 
                 (car (reverse sorted-stems-dirs-list)))))
                 
  (if (and equal-stems-dir? (= (car sorted-stems-dirs-list) tuplet-dir))
    (ly:grob-set-property! grob 'direction (* -1 (car sorted-stems-dirs-list)))
    ;; With 2.14.2 the log-warning is sometimes misleading.
    ;; Works nice with higher versions.
    (ly:warning 
      "Kneed beam detected - if desired, adjust TupletBracket manually."))))

\relative c' {
        \override TupletBracket.bracket-visibility = ##t
        \tupletAtNoteHeads
        \tuplet 3/2 { a'8 b c }
        \tuplet 3/2 { r8 d e } 
        \tuplet 3/2 { r8 r f, }
        \tuplet 3/2 { g, a'' r } 
        \tuplet 3/2 { c,,8 c c }
        \tuplet 3/2 { r8 c c } 
        \tuplet 3/2 { r8 r c }
        \tuplet 3/2 { c c'' r }
}