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

Chapter 3. Parallelization Using Reducers

Reducers are another way of looking at collections in Clojure. In this chapter, we will study this particular abstraction of collections, and how it is quite orthogonal to viewing collections as sequences. The motivation behind reducers is to increase the performance of computations over collections. This performance gain is achieved mainly through parallelization of such computations.

As we have seen in Chapter 1, Working with Sequences and Patterns, sequences and laziness are a great way to handle collections. The Clojure standard library provides several functions to handle and manipulate sequences. However, abstracting a collection as a sequence has an unfortunate consequence; any computation performed over all the elements of a sequence is inherently sequential. Also, all of the standard sequence functions create a new collection that is similar to the collection passed to these functions. Interestingly, performing a computation over a collection...