-- Package spec for Lax Wendroff scheme to solve 1-D
-- Advection PDE in Ada 2005
-- by Nasser M. Abbasi
--
with Ada.Numerics.Generic_Real_Arrays;
package Lax_Wendroff_pkg is
   type Lax_Wendroff_t (<>) is tagged private;
   type solution_t is array (Natural range <>) of Float;

   -- primitive operations, constructor
   function make(speed,h,k : Float; u0 : solution_t) return  Lax_Wendroff_t;
   procedure step (o : in out Lax_Wendroff_t);
   function get_solution (o : Lax_Wendroff_t) return solution_t;

private
   package My_Vectors is new Ada.Numerics.Generic_Real_Arrays (Float);
   use My_Vectors;
   subtype buffer_t is Real_Vector;

   type Lax_Wendroff_t (N : Positive) is tagged record
      speed       : Float;                -- speed of flow
      h           : Float;                -- space grid size
      k           : Float;                -- delt
      u           : buffer_t (-1 .. N);   -- solution
      step_number : Natural;
   end record;

end Lax_Wendroff_pkg;