Functional reactive programming frp is a programming paradigm for reactive programming asynchronous dataflow programming using the building blocks of functional programming eg map reduce filterfrp has been used for programming graphical user interfaces guis robotics games and music aiming to simplify these problems by explicitly modeling time. Functional reactive programming is not intuitive most people start by coding proactively and impurely myself included you do it long enough and it starts to solidify in your mind that proactive impure coding is the only solution breaking free of this mindset can enable you to write more effective code through functional reactive programming. Fundamentally functional reactive programming is the observer pattern with support for manipulating and transforming the stream of data our observables emit in the example above the observables are a pipeline our data will flow through to recap the observer pattern involves two roles an observable and one or many observers the observable emits events while the observer subscribes and receives them. A quick introduction to functional reactive programming frp frp represents an intersection of two programming paradigms but before we dig deeper into the concepts we need to know a bit more about some basic terms frp reacting to events imperative programming traditionally we write code that describes how it should solve a problem