anchor.diff:  -author('jensvfischer@gmail.com').
   -vsn('$Id$').
   
  --export_type([exch_data/0, round_status/0, cb_return/0, instance/0]).
  -
   % for behaviour
   -ifndef(have_callback_support).
   -export([behaviour_info/1]).
   -endif.
  +
  +% Erlang version >= R15B
  +-ifdef(have_callback_support).
  +
  +-export_type([exch_data/0, round_status/0, cb_return/0, instance/0]).
   
   %% cb: callback
   -type cb_state() :: any().
  
positive.code: -type round() :: non_neg_integer().
  -type round_status() :: 'current_round' | 'old_round'.
  -type notify_keyword() :: new_round | leader | exch_failure.
  
  % Erlang version >= R15B
  -ifdef(have_callback_support).
  
  % Startup
  
  
negative.code:     cb_return().
  
  % Config and Misc
  
  -callback trigger_interval() -> pos_integer().
  
  