Clojure Applied

Building Applications

Once we’ve developed a representation of our data and the basic operations upon it, we need to consider how to build up from there into larger structures that compose an application. This will require things like state, concurrency, and components.

The combination of immutable values and pure functions provides exactly the foundation we need to create and maintain state. In Clojure, state is the current value referenced by an identity. State changes happen when an update function transforms the current value to a new value. Clojure has several stateful reference types that can establish a shared identity. You’ll learn how to select the best reference type for your needs.

Although this state model is simple, it’s the secret ...