-- Copyright (C) 1996 Morgan Kaufmann Publishers, Inc

-- This file is part of VESTs (Vhdl tESTs).

-- VESTs is free software; you can redistribute it and/or modify it
-- under the terms of the GNU General Public License as published by the
-- Free Software Foundation; either version 2 of the License, or (at
-- your option) any later version. 

-- VESTs is distributed in the hope that it will be useful, but WITHOUT
-- ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
-- FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
-- for more details. 

-- You should have received a copy of the GNU General Public License
-- along with VESTs; if not, write to the Free Software Foundation,
-- Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 

-- ---------------------------------------------------------------------
--
-- $Id: ch_17_fg_17_07.vhd,v 1.2 2001-10-26 16:29:36 paw Exp $
-- $Revision: 1.2 $
--
-- ---------------------------------------------------------------------

entity fg_17_07 is

end entity fg_17_07;


----------------------------------------------------------------


architecture test of fg_17_07 is

  signal s : bit_vector(0 to 3);

begin

  process is

            type value_cell;

          type value_ptr is access value_cell;

          type value_cell is record
                               value : bit_vector(0 to 3);
                               next_cell : value_ptr;
                             end record value_cell;

          variable value_list, current_cell : value_ptr;
          variable search_value : bit_vector(0 to 3);

  begin
    value_list := new value_cell'( B"1000", value_list );
    value_list := new value_cell'( B"0010", value_list );
    value_list := new value_cell'( B"0000", value_list );

    search_value := B"0010";

    -- code from book:

    current_cell := value_list;
    while current_cell /= null
      and current_cell.value /= search_value loop
      current_cell := current_cell.next_cell;
    end loop;
    assert current_cell /= null
      report "search for value failed";

    -- end of code from book

    search_value := B"1111";

    current_cell := value_list;
    while current_cell /= null
      and current_cell.value /= search_value loop
      current_cell := current_cell.next_cell;
    end loop;
    assert current_cell /= null
      report "search for value failed";

    wait;
  end process;

end architecture test;