Amiga ACS 1998 #4/amigaacscoverdisc1998-041998.iso/utilities/shareware/dev/ppcsmalleiffel/lib_se/parent_list.e

Text File | 1998-01-16 | 12.0 KB | 636 lines

--          This file is part of SmallEiffel The GNU Eiffel Compiler.
--          Copyright (C) 1994-98 LORIA - UHP - CRIN - INRIA - FRANCE
--            Dominique COLNET and Suzanne COLLIN - [e-mail]
--                       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 PARENT_LIST
   --
   -- To store the parent list of a class.
   --

inherit GLOBALS;

creation make

feature

   base_class: BASE_CLASS;
     -- Where the parent list is written.

   start_position: POSITION;
     -- Of the keyword "inherit".

   heading_comment: COMMENT;
     -- Global comment of the inherit clause.

feature {NONE}

   list: ARRAY[PARENT];

feature

   make(bc: like base_class; sp: like start_position;
    hc: like heading_comment; l: like list) is
      require
     bc /= Void;
     sp /= Void;
     l.lower = 1 and not l.empty;
      do
     base_class := bc;
     heading_comment := hc;
     start_position := sp;
     list := l;
      ensure
     base_class = bc;
     start_position = sp;
     heading_comment = hc;
     list = l;
      end;

   count: INTEGER is
      do
     Result := list.upper;
      end;

   up_to_any_in(pl: FIXED_ARRAY[BASE_CLASS]) is
      local
     i: INTEGER;
     p: PARENT;
     bc: BASE_CLASS;
      do
     from
        i := list.upper;
     until
        i = 0
     loop
        p := list.item(i);
        bc := p.type.base_class;
        if not pl.fast_has(bc) then
           pl.add_last(bc);
        end;
        i := i - 1;
     end;
     from
        i := list.upper;
     until
        i = 0
     loop
        p := list.item(i);
        bc := p.type.base_class;
        if bc /= class_any then
           bc.up_to_any_in(pl);
        end;
        i := i - 1;
     end;
      end;

   base_class_name: CLASS_NAME is
      do
     Result := base_class.base_class_name;
      end;

   has_redefine(fn: FEATURE_NAME): BOOLEAN is
      require
     fn /= Void
      local
     i: INTEGER;
      do
     from
        i := 1;
     until
        Result or else i > list.upper
     loop
        Result := list.item(i).has_redefine(fn);
        i := i + 1;
     end;
      end;

   super: PARENT is
      require
     count = 1
      do
     Result := list.first;
      end;

feature {TYPE}

   smallest_ancestor(ctx: TYPE): TYPE is
      require
     ctx.is_run_type;
      local
     i: INTEGER;
     p: PARENT;
     sa: TYPE;
      do
     from
        i := list.upper;
     until
        i = 0
     loop
        p := list.item(i);
        sa := p.smallest_ancestor(ctx).run_type;
        if Result = Void then
           Result := sa;
        else
           Result := sa.smallest_ancestor(Result);
        end;
        if Result.is_any then
           i := 0;
        else
           i := i - 1;
        end;
     end;
      ensure
     Result.is_run_type;
      end;

feature {BASE_CLASS}

   up_to_original(bottom: BASE_CLASS; top_fn: FEATURE_NAME): FEATURE_NAME is
      local
     p1, p2: PARENT;
     fn1, fn2, new_fn: FEATURE_NAME;
     i: INTEGER;
      do
     from
        i := list.upper;
     until
        i = 0 or else fn1 /= Void
     loop
        p1 := list.item(i);
        fn1 := p1.up_to_original(bottom,top_fn);
        i := i - 1;
     end;
     from
     until
        i = 0
     loop
        p2 := list.item(i);
        fn2 := p2.up_to_original(bottom,top_fn);
        if fn2 /= Void then
           new_fn := p2.do_rename(top_fn);
           if p2.has_select_for(new_fn) then
          p1 := p2;
          fn1 := fn2;
           end;
        end;
        i := i - 1;
     end;
     if fn1 /= Void then
        if fn1.to_string /= top_fn.to_string then
           Result := repeated_inheritance(p1,fn1,top_fn);
        else
           Result := fn1;
        end;
     end;
      end;

   clients_for(fn: FEATURE_NAME): CLIENT_LIST is
      require
     fn /= Void
      local
     i: INTEGER;
     cl: CLIENT_LIST;
      do
     from
        i := list.upper;
     until
        i = 0
     loop
        cl := list.item(i).clients_for(fn);
        if Result = Void then
           Result := cl;
        elseif cl /= Void then
           Result := Result.append(cl);
        end;
        if Result /= Void and then Result.gives_permission_to_any then
           i := 0;
        else
           i := i - 1;
        end;
     end;
      ensure
     Result /= Void
      end;

   going_up(trace: FIXED_ARRAY[PARENT]; top: BASE_CLASS;
        top_fn: FEATURE_NAME;): FEATURE_NAME is
      require
     top /= Void;
     top_fn /= Void
      local
     i: INTEGER;
     p1, p2: PARENT;
     fn1, fn2: FEATURE_NAME;
      do
     from
        i := list.upper;
     until
        fn1 /= Void or else i = 0
     loop
        p1 := list.item(i);
        fn1 := p1.going_up(trace,top,top_fn);
        i := i - 1;
     end;
     from
     until
        i = 0
     loop
        p2 := list.item(i);
        fn2 := p2.going_up(trace,top,top_fn);
        if fn2 /= Void then
           if p2.has_select_for(fn2) then
          p1 := p2;
          fn1 := fn2;
           end;
        end;
        i := i - 1;
     end;
     Result := fn1;
      end;

   is_a_vncg(t1, t2: TYPE): BOOLEAN is
      require
     t1.run_type = t1;
     t2.run_type = t2;
     t2.generic_list /= Void;
     eh.empty
      local
     i: INTEGER;
      do
     from
        i := list.upper;
     until
        Result or else i = 0
     loop
        Result := list.item(i).is_a_vncg(t1,t2);
        i := i - 1;
     end;
      ensure
     eh.empty
      end;

   has(fn: FEATURE_NAME): BOOLEAN is
      local
     i: INTEGER;
      do
     from
        i := list.upper;
     until
        Result or else i = 0
     loop
        Result := list.item(i).has(fn);
        i := i - 1;
     end;
      end;

   collect_invariant(rc: RUN_CLASS) is
      require
     rc /= Void
      local
     i: INTEGER;
      do
     from
        i := list.upper;
     until
        i = 0
     loop
        list.item(i).type.base_class.collect_invariant(rc);
        i := i - 1;
     end;
      end;

   inherit_cycle_check is
      local
     i: INTEGER;
     p: PARENT;
     bc: BASE_CLASS;
      do
     from
        i := list.upper;
     until
        i = 0
     loop
        p := list.item(i);
        bc := p.type.base_class;
        if bc = Void then
           eh.add_position(p.start_position);
           fatal_error(fz_cnf);
        else
           bc.inherit_cycle_check;
        end;
        i := i - 1;
     end;
      end;

   has_parent(c: BASE_CLASS): BOOLEAN is
      require
     not c.is_any
      local
     i: INTEGER;
     bc: BASE_CLASS;
      do
     from
        i := list.upper;
     until
        i = 0
     loop
        bc := list.item(i).type.base_class;
        if c = bc then
           Result := true;
           i := 0;
        elseif bc.is_subclass_of_aux(c) then
           Result := true;
           i := 0;
        else
           i := i - 1;
        end;
     end;
      end;

feature {BASE_CLASS}

   first_parent_for(c: BASE_CLASS): PARENT is
     -- Gives the first parent going to `c'.
      local
     i: INTEGER;
     pbc: BASE_CLASS;
      do
     from
        i := 1;
     until
        Result /= Void
     loop
        Result := list.item(i);
        pbc := Result.type.base_class;
        if pbc = c then
        elseif pbc.is_subclass_of(c) then
        else
           Result := Void;
        end;
        i := i + 1;
     end;
      ensure
     Result /= Void
      end;

   next_parent_for(c: BASE_CLASS; previous: PARENT): like previous is
     -- Gives the next one or Void.
      local
     i: INTEGER;
     pbc: BASE_CLASS;
      do
     from
        from
           i := 1;
        until
           Result = previous
        loop
           Result := list.item(i);
           i := i + 1;
        end;
        Result := Void;
     until
        Result /= Void or else i > list.count
     loop
        Result := list.item(i);
        pbc := Result.type.base_class;
        if pbc = c then
        elseif pbc.is_subclass_of(c) then
        else
           Result := Void;
        end;
        i := i + 1;
     end;
      end;

feature {BASE_CLASS}

   header_comment_for(ci: CLASS_INVARIANT) is
      local
     i: INTEGER;
      do
     from
        i := list.upper;
     until
        i = 0 or else ci.header_comment /= Void
     loop
        list.item(i).type.base_class.header_comment_for(ci);
        i := i - 1;
     end;
      end;

feature {BASE_CLASS}

   get_started is
      local
     i1, i2: INTEGER;
     p1, p2: PARENT;
      do
     from
        i1 := list.upper;
     until
        i1 = 0
     loop
        list.item(i1).get_started(Current);
        i1 := i1 - 1;
     end;
     if list.upper > 1 then
        -- Checking select :
        from
           i2 := list.upper;
        until
           i2 = 1
        loop
           from
          i1 := 1;
           invariant
          i1 < i2 + 1
           variant
          i2 - i1
           until
          i1 = i2
           loop
          p1 := list.item(i1);
          p2 := list.item(i2);
          p1.multiple_check(p2);
          p2.multiple_check(p1);
          i1 := i1 + 1;
           end;
           i2 := i2 - 1;
        end;
     end;
      end;

feature {BASE_CLASS}

   look_up_for(rc: RUN_CLASS; fn: FEATURE_NAME): E_FEATURE is
      local
     i: INTEGER;
     p1, p2: PARENT;
     f1, f2: E_FEATURE;
      do
     from
        i := list.upper;
     until
        f1 /= Void or else i = 0
     loop
        p1 := list.item(i);
        f1 := p1.look_up_for(rc,fn);
        i := i - 1;
     end;
     from
     until
        i = 0
     loop
        p2 := list.item(i);
        f2 := p2.look_up_for(rc,fn);
        if f2 = Void then
        elseif f1 = f2 then
        elseif not f2.is_merge_with(f1,rc) then
           eh.add_position(start_position);
           eh.add_position(f1.start_position);
           eh.add_position(f2.start_position);
           fatal_error(fz_ich);
        elseif f2.is_deferred then
        elseif f1.is_deferred then
           f1 := f2;
           p1 := p2;
        elseif p1.has_redefine(fn) then
           if p2.has_redefine(fn) then
           else
          eh.add_position(fn.start_position);
          eh.add_position(p2.start_position);
          eh.add_position(f2.start_position);
          eh.append(em1);
          eh.print_as_fatal_error;
           end;
        elseif p2.has_redefine(fn) then
           eh.add_position(fn.start_position);
           eh.add_position(p1.start_position);
           eh.add_position(f1.start_position);
           eh.append(em1);
           eh.print_as_fatal_error;
        else
           eh.add_position(p2.start_position);
           eh.add_position(p1.start_position);
           eh.add_position(f1.start_position);
           eh.add_position(f2.start_position);
           eh.append(em1);
           eh.print_as_fatal_error;
        end;
        i := i - 1;
     end;
     Result := f1;
      end;

   collect_for(code: INTEGER; fn: FEATURE_NAME) is
      require
     code = code_require or else code = code_ensure;
     fn /= Void;
      local
     i: INTEGER;
      do
     from
        i := 1;
     until
        i > list.upper
     loop
        list.item(i).collect_for(code,fn);
        i := i + 1;
     end;
      end;

   pretty_print is
      local
     i: INTEGER;
      do
     fmt.set_indent_level(0);
     if fmt.zen_mode then
        fmt.indent;
     else
        fmt.skip(1);
     end;
     fmt.keyword("inherit");
     fmt.set_indent_level(1);
     fmt.indent;
     if heading_comment /= Void then
        heading_comment.pretty_print;
     end;
     from
        i := 1;
     until
        i > list.upper
     loop
        list.item(i).pretty_print;
        i := i + 1;
     end;
      end;

feature {NONE}

   repeated_inheritance(p1: PARENT; fn1, top_fn: FEATURE_NAME): FEATURE_NAME is
      require
     p1 /= void;
     fn1 /= Void;
     top_fn /= Void
      local
     i: INTEGER;
     p2: PARENT;
     bc1: BASE_CLASS;
      do
--***     eh.add_position(p1.start_position);
--***     eh.add_position(top_fn.start_position);
--***     warning(fn1.start_position,"REPEATED INHERITANCE");

     from
        bc1 := p1.type.base_class;
        i := list.upper;
     until
        i = 0
     loop
        p2 := list.item(i);
        if p1 /= p2 then
           if bc1 = p2.type.base_class then
          if p2.do_rename(fn1).to_string = top_fn.to_string then
             Result := top_fn;
          elseif p1.do_rename(fn1).to_string = top_fn.to_string then
             Result := top_fn;
          end;
           end;
        end;
        i := i - 1;
     end;
     if Result = Void then
        Result := fn1;
     end;
      ensure
     top_fn /= Void
      end;


feature {NONE}

   em1: STRING is "Inheritance clash.";

invariant

   base_class /= Void;

   list.lower = 1;

   not list.empty;

end -- PARENT_LIST