Reactive programming is widely used in GUI, backend development, Game AI, build system and many other areas.

The life cycle management for observable objects becomes a tough problem when the graph of dependencies is dynamically changed. Most Functional Reactive Programming (FRP) frameworks implement impure map and flatMap methods to subscribe events, which are error-prone, causing leak memory or duplicate events.

In Binding.scala, we introduced a new approach that resolves the life cycle management problem.

In this talk, the attendees will learn this approach. They will understand why and how to separate a reactive system into the pure DSL part and the impure runtime part, and finally create a declarative style DSL for reactive programming. The approach they learnt can be applied to various domains, not only for Binding.scala, but also for other reactive systems.