-- Chapter 31 - Program 2
package EasyPkg is
   procedure Trade_Values (X, Y : in out INTEGER);

   generic
      type MY_REAL_TYPE is digits <>;
   package Nested_Generic is
      function Average_Values (X, Y : MY_REAL_TYPE)
                                          return MY_REAL_TYPE;
   end Nested_Generic;
end EasyPkg;


package body EasyPkg is
   procedure Trade_Values (X, Y : in out INTEGER) is
   Temp : INTEGER;
   begin
      Temp := X;
      X := Y;
      Y := Temp;
   end Trade_Values;

   package body Nested_Generic is
      function Average_Values (X, Y : MY_REAL_TYPE)
                                          return MY_REAL_TYPE is
      begin
         return (X + Y) / 2.0;
      end Average_Values;
   end Nested_Generic;

end EasyPkg;



with Ada.Text_IO, EasyPkg;
use Ada.Text_IO, EasyPkg;

procedure NestPkg is

type MY_NEW_FLOAT is new FLOAT digits 6;

package Funny_Stuff is new EasyPkg.Nested_Generic(MY_NEW_FLOAT);
use Funny_Stuff;
package Usual_Stuff is new Nested_Generic(FLOAT);
use Usual_Stuff;

Int1 : INTEGER := 12;
Int2 : INTEGER := 35;

Real1 : FLOAT;
My_Real1 : MY_NEW_FLOAT;

begin
   Trade_Values(Int1, Int2);         -- Uses Trade_Values directly
   EasyPkg.Trade_Values(Int1, Int2); -- Uses Trade_Values directly
-- Usual_Stuff.Trade_Values(Int1, Int2);    -- Illegal
-- Funny_Stuff.Trade_Values(Int1, Int2);    -- Illegal

   Real1 := Average_Values(2.71828, 3.141592);
   Real1 := Average_Values(Real1, 2.0 * 3.141592);
   My_Real1 := Average_Values(12.3, 27.345);
   My_Real1 := Average_Values(My_Real1, 2.0 * 3.141592);
   My_Real1 := Funny_Stuff.Average_Values(12.3, 27.345);
end NestPkg;




-- Result of execution

-- (There is no output from this program)