An app written in the functional-programming style has no clear way of storing state—functions are not supposed to store state between successive calls (in an imperative way, like using an object variable.)
A common approach in FP for solving the state problem is global state—a data structure represents the global state. Top-level functions operate on the global state.
As we’ll see, in contrast to Action Streams, this approach diverges from the Flux architecture. Continue reading