anchor.diff:  
   type
     TMessage = class;
  -  TActor = class(TObj)
  +  TActor = class
       active,           { wants update() }
       alive,            { exists but not alive triggers gc }
       visible,          { to allow hide/show }
  
positive.code:     color := $13; { cyan on blue }
    end;
  
  function TClockMorph.Str: string;
    begin
      result := FormatDateTime('MM.DD.YY hh:mm:ssam/pm', Now);
    end;
  
  procedure TClockMorph.Render;
    begin
      cw.cxy( color, bounds.x, bounds.y, self.str )
    end;
  
  
negative.code:       first : TFieldDef;
      end;
  
    TFieldDef = class
      public
        next : TFieldDef;
        name : TSymbol;
      end;
  
    TTuple = class
      public
        meta : TTypeDef;
        data : TBytes;
  