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 channels


The core.async library (https://github.com/clojure/core.async) facilitates asynchronous programming in Clojure. Through this library, we can use asynchronous constructs that run on both the JVM and web browsers without dealing with how they are scheduled for execution on low-level threads. This library is an implementation of the theory in the paper Communicating Sequential Processes (CSPs), originally published in the late '70s by C. A. R. Hoare. The bottom line of CSPs is that any system that processes some input and provides an output can be comprised of smaller subsystems, and each subsystem can be defined in terms of processes and queues. A queue simply buffers data, and a process can read from and write to several queues. Here, we shouldn't confuse the term process with an operating system process. In the context of CSPs, a process is simply a sequence of instructions that interacts with some data stored in queues. Several processes may exist in a given system and...