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

Debugging your code


Along your journey of building applications and libraries in Clojure, you'll surely run into situations where it would be helpful to debug your code. The usual response to such a situation is to use an Integrated Development Environment (IDE) with a debugger. And while Clojure IDEs such as CIDER (https://github.com/clojure-emacs/cider) and Counterclockwise (http://doc.ccw-ide.org) do support debugging, there are a few simpler constructs and tools that we can use to troubleshoot our code. Let's have a look at a few of them.

One of the easiest ways to debug your code is by printing the value of some variables used within a function. We could use the standard println function for this purpose, but it doesn't always produce the most readable output for complex data types. As a convention, we should use the clojure.pprint/pprint function to print variables to the console. This function is the standard pretty-printer of the Clojure language.

Note

Macros can be quite bewildering...