package body Bin_Search is


   -- This procedure no longer contains an error
   procedure Binary_Search (List     : in  Integer_Array;
                            Value    : in  Integer;
                            Location : out Natural) is

      Found       : Boolean;  -- Has Value been found yet?          
      Midpoint    : Natural;  -- Index of search area's midpoint    
      First_Index : Natural;  -- First index in current search area 
      Last_Index  : Natural;  -- Last index in current search area  

   begin   
      Found       := False;
      First_Index := List'First;
      Last_Index  := List'Last;

     -- Search until element found or the current search area is empty.
     -- Current search area is List (First_Index..Last_Index)
      loop
         exit when First_Index > Last_Index  or  Found;
         -- Find middle element in the current search area. 
         Midpoint := (First_Index + Last_Index) / 2;
         -- Compare Value to middle element in search area. 
         if List(Midpoint) = Value then
            Found := True;
         elsif Value < List(Midpoint) then
            Last_Index := Midpoint - 1;   -- Search area now 1st half
         else 
            First_Index := Midpoint + 1;  -- Search area now 2nd half
         end if;
      end loop;
      -- Set value of Location. 
      if Found then 
         Location := Midpoint;
      else 
         Location := 0;
      end if;
   end Binary_Search;

end Bin_Search;