1. package Game_States is 
  2.  
  3.     -- Presents a view of the current game session's state. The Game class 
  4.     -- implements this so that game components can access the session's state 
  5.     -- without having a full reference to the Game class. 
  6.     type Game_State is limited interface; 
  7.     type A_Game_State is access all Game_State'Class; 
  8.  
  9.     -- Returns the value of game session var 'var' as an integer. An exception 
  10.     -- will be raised on error. 
  11.     function Get_Game_Var( this : access Game_State; 
  12.                            var  : String ) return Integer is abstract; 
  13.  
  14. end Game_States;