text: /*
   * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #pragma once
  
  #include <AK/Format.h>
  #include <AK/Forward.h>
  #include <AK/Noncopyable.h>
  #include <AK/String.h>
  #include <AK/TypeCasts.h>
  #include <LibJS/Forward.h>
  
  namespace JS {
  
  class Cell {
      AK_MAKE_NONCOPYABLE(Cell);
      AK_MAKE_NONMOVABLE(Cell);
  
  public:
      virtual void initialize(GlobalObject&) { }
      virtual ~Cell() { }
  
      bool is_marked() const { return m_mark; }
      void set_marked(bool b) { m_mark = b; }
  
      bool is_live() const { return m_live; }
      void set_live(bool b) { m_live = b; }
  
      virtual const char* class_name() const = 0;
  
      class Visitor {
      public:
          void visit(Cell*);
          void visit(Value);
  
      protected:
          virtual void visit_impl(Cell*) = 0;
      };
  
      virtual void visit_edges(Visitor&) { }
  
      Heap& heap() const;
      VM& vm() const;
  
  protected:
      Cell() { }
  
  private:
      bool m_mark { false };
      bool m_live { true };
  };
  
  }
  
  namespace AK {
  
  template<>
  struct Formatter<JS::Cell> : Formatter<StringView> {
      void format(FormatBuilder& builder, const JS::Cell* cell)
      {
          if (!cell)
              Formatter<StringView>::format(builder, "Cell{nullptr}");
          else
              Formatter<StringView>::format(builder, String::formatted("{}{{{}}}", cell->class_name(), static_cast<const void*>(cell)));
      }
  };
  
  }
  