+ static int visible_stem_count (Grob *);
+ static Grob *first_visible_stem (Grob *);
+ static Grob *last_visible_stem (Grob *);
+ DECLARE_GROB_INTERFACE();
+ static void add_stem (Grob *, Grob *);
+ static bool is_knee (Grob *);
+ static void set_beaming (Grob *, Beaming_pattern const *);
+ static void set_stemlens (Grob *);
+ static int get_beam_count (Grob *me);
+ static Real get_beam_translation (Grob *me);
+ static Real get_thickness (Grob *me);
+ static void connect_beams (Grob *me);
+ static vector<Beam_segment> get_beam_segments (Grob *me_grob, Grob **common);
+
+ DECLARE_SCHEME_CALLBACK (rest_collision_callback, (SCM element, SCM prev_off));
+ DECLARE_SCHEME_CALLBACK (print, (SCM));
+ DECLARE_SCHEME_CALLBACK (calc_beaming, (SCM));
+ DECLARE_SCHEME_CALLBACK (calc_stem_shorten, (SCM));
+ DECLARE_SCHEME_CALLBACK (calc_direction, (SCM));
+ DECLARE_SCHEME_CALLBACK (calc_positions, (SCM));
+ DECLARE_SCHEME_CALLBACK (calc_least_squares_positions, (SCM, SCM));
+ DECLARE_SCHEME_CALLBACK (calc_concaveness, (SCM));
+ DECLARE_SCHEME_CALLBACK (set_stem_lengths, (SCM));
+
+ /* position callbacks */
+ DECLARE_SCHEME_CALLBACK (shift_region_to_valid, (SCM, SCM));
+ DECLARE_SCHEME_CALLBACK (slope_damping, (SCM, SCM));
+ DECLARE_SCHEME_CALLBACK (quanting, (SCM, SCM));