Reactive programming keeps computations alive: instead of calculating one result from fixed inputs, it feeds formulas with changing environmental data so they continually produce updated results. This suits systems whose safety or behavior depends on responding to new information. section 8.1
Spaceflight formulas
A rocket’s fuel calculation can be performed once, but a spacecraft contains interconnected systems whose conditions change during flight. Reactive programming provides an environment where those formulas respond to incoming data rather than relying on complete precomputation. section 8.1
Reactive applications can be organized through several designs:
- Use actors to organize stateful applications, while recognizing that safe and reliable actor interactions carry a cost. section 8.3
- Use reactive streams or custom event-driven models to structure data arriving over time. section 8.1
- Treat communication protocols as contracts between actors; larger concurrent models may outgrow MVars and benefit from STM or message queues. section 8.3
