text: namespace factor
  {
  
  static const cell special_object_count = 70;
  
  enum special_object {
  	OBJ_NAMESTACK,             /* used by library only */
  	OBJ_CATCHSTACK,            /* used by library only, per-callback */
  
  	OBJ_CURRENT_CALLBACK = 2,  /* used by library only, per-callback */
  	OBJ_WALKER_HOOK,           /* non-local exit hook, used by library only */
  	OBJ_CALLCC_1,              /* used to pass the value in callcc1 */
  
  	ERROR_HANDLER_QUOT = 5,    /* quotation called when VM throws an error */
  	OBJ_ERROR,                 /* a marker consed onto kernel errors */
  
  	OBJ_CELL_SIZE = 7,         /* sizeof(cell) */
  	OBJ_CPU,                   /* CPU architecture */
  	OBJ_OS,                    /* operating system name */
  
  	OBJ_ARGS = 10,             /* command line arguments */
  	OBJ_STDIN,                 /* stdin FILE* handle */
  	OBJ_STDOUT,                /* stdout FILE* handle */
  
  	OBJ_IMAGE = 13,            /* image path name */
  	OBJ_EXECUTABLE,            /* runtime executable path name */
  
  	OBJ_EMBEDDED = 15,         /* are we embedded in another app? */
  	OBJ_EVAL_CALLBACK,         /* used when Factor is embedded in a C app */
  	OBJ_YIELD_CALLBACK,        /* used when Factor is embedded in a C app */
  	OBJ_SLEEP_CALLBACK,        /* used when Factor is embedded in a C app */
  
  	OBJ_COCOA_EXCEPTION = 19,  /* Cocoa exception handler quotation */
  
  	OBJ_STARTUP_QUOT = 20,     /* startup quotation */
  	OBJ_GLOBAL,                /* global namespace */
  	OBJ_SHUTDOWN_QUOT,         /* shutdown quotation */
  
  	/* Quotation compilation in quotations.c */
  	JIT_PROLOG = 23,
  	JIT_PRIMITIVE_WORD,
  	JIT_PRIMITIVE,
  	JIT_WORD_JUMP,
  	JIT_WORD_CALL,
  	JIT_IF_WORD,
  	JIT_IF,
  	JIT_EPILOG,
  	JIT_RETURN,
  	JIT_PROFILING,
  	JIT_PUSH_IMMEDIATE,
  	JIT_DIP_WORD,
  	JIT_DIP,
  	JIT_2DIP_WORD,
  	JIT_2DIP,
  	JIT_3DIP_WORD,
  	JIT_3DIP,
  	JIT_EXECUTE,
  	JIT_DECLARE_WORD,
  
  	/* External entry points */
  	C_TO_FACTOR_WORD,
  	LAZY_JIT_COMPILE_WORD,
  	UNWIND_NATIVE_FRAMES_WORD,
  
  	/* Incremented on every modify-code-heap call; invalidates call( inline
  	caching */
  	REDEFINITION_COUNTER = 47,
  
  	/* Callback stub generation in callbacks.c */
  	CALLBACK_STUB = 48,
  	
  	/* Polymorphic inline cache generation in inline_cache.c */
  	PIC_LOAD = 49,
  	PIC_TAG,
  	PIC_TUPLE,
  	PIC_CHECK_TAG,
  	PIC_CHECK_TUPLE,
  	PIC_HIT,
  	PIC_MISS_WORD,
  	PIC_MISS_TAIL_WORD,
  
  	/* Megamorphic cache generation in dispatch.c */
  	MEGA_LOOKUP = 57,
  	MEGA_LOOKUP_WORD,
  	MEGA_MISS_WORD,
  
  	OBJ_UNDEFINED = 60,       /* default quotation for undefined words */
  
  	OBJ_STDERR = 61,          /* stderr FILE* handle */
  
  	OBJ_STAGE2 = 62,          /* have we bootstrapped? */
  
  	OBJ_CURRENT_THREAD = 63,
  
  	OBJ_THREADS = 64,
  	OBJ_RUN_QUEUE = 65,
  	OBJ_SLEEP_QUEUE = 66,
  
  	OBJ_VM_COMPILER = 67,    /* version string of the compiler we were built with */
  };
  
  /* save-image-and-exit discards special objects that are filled in on startup
  anyway, to reduce image size */
  #define OBJ_FIRST_SAVE OBJ_STARTUP_QUOT
  #define OBJ_LAST_SAVE OBJ_STAGE2
  
  inline static bool save_special_p(cell i)
  {
  	return (i >= OBJ_FIRST_SAVE && i <= OBJ_LAST_SAVE);
  }
  
  template<typename Iterator> void object::each_slot(Iterator &iter)
  {
  	cell scan = (cell)this;
  	cell payload_start = binary_payload_start();
  	cell end = scan + payload_start;
  
  	scan += sizeof(cell);
  
  	while(scan < end)
  	{
  		iter((cell *)scan);
  		scan += sizeof(cell);
  	}
  }
  
  }
  