struct FRAME {
  VALUE self;
  int argc;
  ID last_func;
  ID orig_func;
  VALUE last_class;
  struct FRAME *prev;
  struct FRAME *tmp;
  struct RNode *node;
  int iter;
  int flags;
  unsigned long uniq;
};

struct SCOPE {
  struct RBasic super;
  ID *local_tbl;
  VALUE *local_vars;
  int flags;
};

struct RVarmap {
  struct RBasic super;
  ID id;
  VALUE val;
  struct RVarmap *next;
};