--          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.
--
deferred class DECLARATION_LIST
   --
   -- For a formal arguments list (FORMAL_ARG_LIST) or for a local 
   -- variable list (LOCAL_VAR_LIST).
   --
   -- Exemple :
   --
   --   foo, bar : ZOO; x : INTEGER
   --
   
inherit GLOBALS;
   
feature {DECLARATION_LIST}
   
   list: ARRAY[DECLARATION];
	 -- Really written list including declaration groups.

   flat_list: ARRAY[like name];
	 -- The same contents as `list' but flat.

feature {NONE}
   
   declaration_list_make(l: like list) is
	 -- Common part of creation.
      require
	 l.lower = 1;
	 not l.empty
      local
	 il, actual_count: INTEGER;
      do
	 list := l;
	 from  
	    il := list.upper;
	 until
	    il = 0
	 loop
	    actual_count := actual_count + list.item(il).count;
	    il := il - 1;
	 end;
	 from  
	    !!flat_list.make(1,actual_count);
	    il := 1;
	 until
	    il > list.upper
	 loop
	    list.item(il).append_in(Current);
	    il := il + 1;
	 end;
      ensure
	 list = l;
	 flat_list /= Void
      end;

feature 

   start_position: POSITION is
      do
	 Result := flat_list.first.start_position;
      end;

   pretty_print is
      require
	 fmt.indent_level >= 2;
      deferred
      ensure
	 fmt.indent_level = old fmt.indent_level;
      end;
   
   count: INTEGER is
      do 
	 Result := flat_list.upper;
      end;
   
   rank_of(n: STRING): INTEGER is
	 -- Result is greater than 0 when `n' is in the list.
      require
	 unique_string.item(n) = n
      do
	 from
	    Result := count
	 until
	    Result = 0 or else n = name(Result).to_string
	 loop
	    Result := Result - 1;
	 end;
      ensure
	 0 <= Result;
	 Result <= count;
      end;
     
   name(i: INTEGER): LOCAL_ARGUMENT1 is
      require
	 1 <= i;
	 i <= count
      deferred
      ensure
	 Result /= Void
      end;
   
   type(i: INTEGER): TYPE is
      require
	 1 <= i;
	 i <= count;
      do
	 Result := name(i).result_type;
      ensure
	 Result /= Void
      end;
      
feature {DECLARATION}

   add_last(n: like name) is
      local
	 i: INTEGER;
	 n2: like name;
      do
	 from
	    i := 1;
	 until
	    flat_list.item(i) = Void
	 loop
	    n2 := flat_list.item(i);
	    if n2.to_string = n.to_string then
	       eh.add_position(n.start_position);
	       eh.add_position(n2.start_position);
	       fatal_error("Same name appears twice.");
	    end;
	    i := i + 1;
	 end;
	 flat_list.put(n,i);
	 n.set_rank(i);
      end;

feature {RUN_FEATURE}

   frozen jvm_stack_space: INTEGER is
	 -- Number of needed words in the JVM stack.
      local
	 i: INTEGER;
      do
	 from
	    i := count;
	 until
	    i = 0
	 loop
	    Result := Result + type(i).run_type.jvm_stack_space;
	    i := i - 1;
	 end;
      end;
   
feature {RUN_FEATURE}

   frozen jvm_offset_of(la: LOCAL_ARGUMENT): INTEGER is
      local
	 i, rank: INTEGER;
      do
	 from
	    rank := la.rank;
	    i := 1;
	 variant
	    count - i
	 until
	    i = rank
	 loop
	    Result := Result + type(i).run_type.jvm_stack_space;
	    i := i + 1;
	 end;
      end;

feature {NONE}

   em1: STRING is "Bad declaration.";

feature

   frozen is_runnable(ct: TYPE): BOOLEAN is
      local
	 i: INTEGER;
	 n1, n2: like name;
	 t: TYPE;
      do
	 from
	    Result := true;
	    i := flat_list.upper;
	 until
	    not Result or else i = 0
	 loop
	    t := type(i);
	    if t.is_run_type then
	       if t.run_type /= t then
		  Result := false;
	       end;
	    else
	       Result := false;
	    end;
	    i := i - 1;
	 end;
	 if Result then
	    from
	       i := flat_list.upper;
	    until
	       i = 0
	    loop
	       n1 := flat_list.item(i);
	       n2 := n1.to_runnable(ct);
	       if n2 = Void then
		  error(n1.start_position,em1);
		  i := 0;
	       else
		  i := i - 1;
	       end;
	    end;
	    check_name_clash(ct);
	 end;
      end;

feature {DECLARATION_LIST}

   frozen check_name_clash(ct: TYPE) is
      local
	 i: INTEGER;
      do
	 from
	    i := flat_list.upper;
	 until
	    i = 0
	 loop
	    name(i).name_clash(ct);
	    i := i - 1;
	 end;
      end;
   
   frozen dynamic_runnable(ct: TYPE) is
      local
	 i: INTEGER;
	 n1, n2: like name;
      do
	 flat_list := flat_list.twin;
	 from
	    i := flat_list.upper;
	 until
	    i = 0
	 loop
	    n1 := flat_list.item(i);
	    n2 := n1.to_runnable(ct);
	    if n2 = Void then
	       error(n1.start_position,em1);
	    else
	       flat_list.put(n2,i);
	    end;
	    i := i - 1;
	 end;
      end;

invariant
   
   count > 0;
   
   flat_list.lower = 1;
   
   count = flat_list.count;
   
   list.count <= count;
   
end -- DECLARATION_LIST