It is essential for modern Android developers-I’d recommend learning it and even migrating your UI if you haven’t already.

Jetpack Compose: This is Android’s current development toolkit for building native UI and is the third library we’ll use today.

It provides almost everything you need to go functional in Kotlin while remaining relatively lightweight.

Arrow: This is one of the best and most popular Kotlin libraries for FP, one we will also use in our sample app.(I am currently the only engineer maintaining it.) It is meant as a starting point for your approach to FRP but is not intended for production use as is since it lacks proper support. Ivy FRP: This is a library I wrote that will be used for educational purposes in this tutorial.There are a variety of Android libraries and tools that can help you get started with FRP, and that are also relevant to functional programming: The functional reactive programming cycle in Android.

Here, we’ve replaced the general reactive elements with real Android components and libraries: The declarative pipeline (indicated as FRPViewModel function).This program includes the same elements as those in a reactive program: (As a reminder, ', pronounced “prime,” indicates a new version of the same variable.) Every FRP program starts with an initial state that will be updated with each event it receives.

The FRP paradigm is an endless cycle of states and events: State -> Event -> State' -> Event' -> State'' -> …. This article is written with Android developers in mind, but the concepts are relevant and beneficial to any developer with experience in general programming languages. This installment will prepare you to apply it, with an overview of useful libraries and a detailed sample implementation. That doesn’t mean understanding this programming paradigm is easy-even seasoned developers may wonder: “What exactly is FRP?” In Part 1 of this tutorial, we defined FRP’s foundational concepts: functional programming and reactive programming. Due to these and many other clear benefits, the use of FRP is going mainstream in mobile and web development. It simplifies complex tasks, creates elegant user interfaces, and manages state smoothly. Functional reactive programming (FRP) is a paradigm that combines the reactivity from reactive programming with the declarative function composition from functional programming.

Reactive programming with kotlin