virtual System *get_system () const;
SCM get_cached_pure_property (SCM sym, int start, int end);
void cache_pure_property (SCM sym, int start, int end, SCM value);
protected:
virtual System *get_system () const;
SCM get_cached_pure_property (SCM sym, int start, int end);
void cache_pure_property (SCM sym, int start, int end, SCM value);
protected: