R++: Adding Path-Based Rules to C++

Object-oriented languages and rule-based languages offer two distinct and useful programming abstractions, yet the two have never been harmoniously integrated in a mainstream language. R++ was developed as a synthesis of these two paradigms that adds path-based rules as a new kind of class member that is subservient to the object-oriented paradigm of C++. Path-based rules--data-driven rules that are restricted to follow pointers between objects--are like "automatic methods" that are triggered by changes to the objects they monitor.