Book Image

Mastering Clojure

By : Akhil Wali
Book Image

Mastering Clojure

By: Akhil Wali

Overview of this book

Clojure is a general-purpose language from the Lisp family with an emphasis on functional programming. It has some interesting concepts and features such as immutability, gradual typing, thread-safe concurrency primitives, and macro-based metaprogramming, which makes it a great choice to create modern, performant, and scalable applications. Mastering Clojure gives you an insight into the nitty-gritty details and more advanced features of the Clojure programming language to create more scalable, maintainable, and elegant applications. You’ll start off by learning the details of sequences, concurrency primitives, and macros. Packed with a lot of examples, you’ll get a walkthrough on orchestrating concurrency and parallelism, which will help you understand Clojure reducers, and we’ll walk through composing transducers so you know about functional composition and process transformation inside out. We also explain how reducers and transducers can be used to handle data in a more performant manner. Later on, we describe how Clojure also supports other programming paradigms such as pure functional programming and logic programming. Furthermore, you’ll level up your skills by taking advantage of Clojure's powerful macro system. Parallel, asynchronous, and reactive programming techniques are also described in detail. Lastly, we’ll show you how to test and troubleshoot your code to speed up your development cycles and allow you to deploy the code faster.
Table of Contents (19 chapters)
Mastering Clojure
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
References
Index

Using functional reactive programming


A more functional flavor of reactive programming is functional reactive programming (abbreviated as FRP). FRP was first described in the late '90s by Conal Elliott, who was a member of the Microsoft Graphics Research Group at the time, and Paul Hudak, a major contributor to the Haskell programming language. FRP was originally described as a bunch of functions to interact with events and behaviors. Both events and behaviors represent values that change over time. The major difference between these two is that events are values that change discretely over time, whereas behaviors are continuously changing values. There is no mention of an observer-observable pattern in FRP. Also, programs in FRP are written as composable transformations of events and behaviors, and are also termed as compositional event systems (CESs).

Modern implementations of FRP provide constructs to create and transform asynchronous event streams. Also, any form of state change is represented...