Practical Functional Reactive Programming

We present our experiences integrating Functional Reactive Programming (FRP) into a new host language, Python, and a variety of computational contexts: a game engine, a GUI system, and an embedded controller. We demonstrate FRP principles extended to a dynamic environment and the integration of object-oriented libraries into the reactive environment. A number of FRP semantic issues are addressed in a straight-forward way to produce an elegant combination of FRP and object-oriented programming. In particular, reactive proxies integrate traditional objects with the reactive world and event-triggered reactors allow reconfiguration of the network of reactive proxies and interaction with the outside world. This work demonstrates that FRP can serve as a unifying framework that simplifies programming and allows novices to build reactive systems. This system has been used to develop a wide variety of game programs and reactive animations in a summer camp which introduces programming concepts to teenagers.