Aminet 30/Aminet 30 (1999)(Schatztruhe)[!][Apr 1999].iso/Aminet/dev/lang/SmallEiffel.lha/SmallEiffel/lib_std/boolean_ref.e

Text File | 1998-12-22 | 3KB | 118 lines

-- This file is  free  software, which  comes  along  with  SmallEiffel. This
-- software  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. You can modify it as you want, provided
-- this header is kept unaltered, and a notification of the changes is added.
-- You  are  allowed  to  redistribute  it and sell it, alone or as a part of
-- another product.
--          Copyright (C) 1994-98 LORIA - UHP - CRIN - INRIA - FRANCE
--            Dominique COLNET and Suzanne COLLIN - [e-mail]
--                       http://www.loria.fr/SmallEiffel
--
class BOOLEAN_REF

inherit
   ANY
      redefine out_in_tagged_out_memory, fill_tagged_out_memory
      end;

creation make

feature

   item: BOOLEAN;
     -- Value of Current

   make(value: BOOLEAN) is
     -- Initialize object
      do
     item := value
      end;

feature

   set_item(value: like item) is
      do
     item := value;
      end;

   infix "and" (other : like Current) : like Current is
     -- `and' of Current with `other'.
      require
     other /= Void
      do
     !!Result.make (item and other.item)
      end;

   infix "and then" (other : like Current) : like Current is
     -- Semi-strict `and' of Current with `other'.
      require
     other /= Void
      do
     !!Result.make (item and then other.item)
      end;

   infix "implies" (other : like Current) : like Current is
     -- Does Current imply `other'.
      require
     other /= Void
      do
     !!Result.make (item implies other.item)
      end;

   infix "or" (other : like Current) : like Current is
     -- `or' of Current with `other'
      require
     other_not_void : other /= Void
      do
     !!Result.make (item or other.item)
      end;

   infix "or else" (other : like Current) : like Current is
     -- Semi-strict `or' of Current with `other'
      require
     other_not_void : other /= Void
      do
     !!Result.make (item or else other.item)
      end;

   infix "xor" (other: like Current): like Current is
     -- `xor' of Current with `other'
      require
     other /= Void
      do
     !!Result.make (item xor other.item)
      end;

   prefix "not": like Current is
     -- `not' of Current.
      do
     !!Result.make(not item)
      end;

   out_in_tagged_out_memory, fill_tagged_out_memory is
      do
     item.fill_tagged_out_memory;
      end;

   to_string: STRING is
      do
     if Current.item then
        Result := "true";
     else
        Result := "false";
     end;
      end;

   to_integer: INTEGER is
      do
     if Current.item then
        Result := 1;
     else
        Result := 0;
     end;
      end;

end -- BOOLEAN_REF