Natools

   function Iterate (Container : in Constant_Map; Start : in Cursor)
     return Map_Iterator_Interfaces.Reversible_Iterator'Class is
   begin
      return Iterator'(Backend => Container.Backend, Start => Start);
   end Iterate;


   function Iterate (Container : in Constant_Map; First, Last : in Cursor)
     return Map_Iterator_Interfaces.Reversible_Iterator'Class is
   begin
      if Is_Empty (Container)
        or else not Has_Element (First)
        or else not Has_Element (Last)
        or else First > Last
      then
         return Iterator'(Backend => Backend_Refs.Null_Immutable_Reference,
           Start => No_Element);
      else
         return Range_Iterator'(Backend => Container.Backend,
                                First_Position => First,
                                Last_Position => Last);
      end if;
   end Iterate;


   function Last (Container : Constant_Map) return Cursor is
   begin
      if Container.Is_Empty then
         return No_Element;
      else
         return (Is_Empty => False,

      else
         return (Is_Empty => False,
            Backend => Object.Backend,
            Index => Object.Backend.Query.Data.Size);
      end if;
   end Last;


   overriding function First (Object : Range_Iterator) return Cursor is
   begin
      return Object.First_Position;
   end First;


   overriding function Last  (Object : Range_Iterator) return Cursor is
   begin
      return Object.Last_Position;
   end Last;


   overriding function Next
     (Object   : Range_Iterator;
      Position : Cursor) return Cursor is
   begin
      if Has_Element (Position) and then Position < Object.Last_Position then
         return Next (Position);
      else
         return No_Element;
      end if;
   end Next;


   overriding function Previous
     (Object   : Range_Iterator;
      Position : Cursor) return Cursor is
   begin
      if Has_Element (Position) and then Position > Object.First_Position then
         return Previous (Position);
      else
         return No_Element;
      end if;
   end Previous;

end Natools.Constant_Indefinite_Ordered_Maps;