Functional Reactive Programming

Chapter 4. Writing a real application

This chapter covers

• Putting primitives together to write real code
• A typical development process
• Modularity
• Testability

We’ve introduced FRP with some contrived examples and shown you some more realistic GUI code. Now we want to show you how to write a real-world FRP application, this time in the industrial space. In this chapter, you’ll develop a petrol pump.

It can be difficult to find the right example for FRP. FRP’s pretensions to stardom conglomerate around the notion that it deals with complexity, but this doesn’t manifest in a small example. If the example is too simple, you’ll say, “That was a weird way of doing things for no apparent benefit.” If the example is too big, it can be a lot of ...