--          This file is part of SmallEiffel The GNU Eiffel Compiler.
--          Copyright (C) 1994-98 LORIA - UHP - CRIN - INRIA - FRANCE
--            Dominique COLNET and Suzanne COLLIN - colnet@loria.fr 
--                       http://www.loria.fr/SmallEiffel
-- SmallEiffel 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, or (at your option)  any  later 
-- version. SmallEiffel 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  SmallEiffel;  see the file COPYING.  If not,
-- write to the  Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-- Boston, MA 02111-1307, USA.
--
class WHEN_ITEM_2
--
-- To store a slice value of a when clause in an inspect instruction.
--
-- Exemple :
--          inspect ...
--              when foo .. bar, then ...
-- 

inherit WHEN_ITEM; 
         
creation {E_WHEN,WHEN_ITEM_2}
   make
   
feature {ANY}
   
   lower, upper: EXPRESSION;
   
   lower_value, upper_value: INTEGER;
   
feature {NONE}
   
   make(l, u: EXPRESSION) is
      require
	 l /= Void;
	 u /= Void
      do
	 lower := l;
	 upper := u;
      ensure
	 lower = l;
	 upper = u
      end;
   
feature {ANY}
   
   start_position: POSITION is
      do
	 Result := lower.start_position;
      end;
   
feature {E_WHEN,WHEN_ITEM_2}
   
   to_runnable_integer(ew: like e_when): like Current is
      local
	 v: like lower;
      do
	 if e_when = Void then
	    e_when := ew;
	    v := lower.to_runnable(current_type);
	    if v /= Void and then v.result_type.is_integer then
	       lower := v; 
	       lower_value := lower.to_integer;
	    else	    
	       error(lower.start_position,fz_biv);
	    end;
	    v := upper.to_runnable(current_type);
	    if v /= Void and then v.result_type.is_integer then
	       upper := v; 
	       upper_value := upper.to_integer;
	    else	    
	       error(upper.start_position,fz_biv);
	    end;
	    e_when.add_when_item_2(Current);
	    Result := Current;
	 else
	    !!Result.make(lower,upper);
	    Result := Result.to_runnable_integer(ew);
	 end;
      end;
   
   to_runnable_character(ew: like e_when): like Current is
      local
	 v: like lower;
      do
	 if e_when = Void then
	    e_when := ew;
	    v := lower.to_runnable(current_type);
	    if v /= Void and then v.result_type.is_character then
	       lower := v; 
	       lower_value := lower.to_integer;
	    else	    
	       error(lower.start_position,fz_bcv);
	    end;
	    v := upper.to_runnable(current_type);
	    if v /= Void and then v.result_type.is_character then
	       upper := v; 
	       upper_value := upper.to_integer;
	    else	    
	       error(upper.start_position,fz_bcv);
	    end;
	    e_when.add_when_item_2(Current);
	    Result := Current;
	 else
	    !!Result.make(lower,upper);
	    Result := Result.to_runnable_character(ew);
	 end;
      end;
   
   pretty_print is
      do
	 lower.pretty_print;
	 fmt.put_string("..");
	 upper.pretty_print;
      end;

feature {E_WHEN}

   eval(exp: INTEGER): BOOLEAN is
      do
	 Result := (lower_value <= exp) and (exp <= upper_value);
      end;

end -- WHEN_ITEM_2