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

Logging errors in your application


Another way to analyze what went wrong in an application is by using logs. Logging can be done using the tools.logging contrib library. This library lets us use multiple logging implementations through an agnostic interface, and the implementations to choose from include slf4j, log4j, and logback. Let's quickly skim over how we can add logging to any Clojure program using the tools.logging library and logback, which is arguably the most recent and configurable implementation to use with this library.

Note

The following library dependencies are required for the upcoming examples:

[org.clojure/tools.logging "0.3.1"]
[ch.qos.logback/logback-classic "1.1.3"]

Also, the following namespaces must be included in your namespace declaration:

(ns my-namespace
  (:require [clojure.tools.logging :as log]))

The following examples can be found in test/m_clj/c11/ logging.clj of the book's source code.

All the logging macros implemented in the clojure.tools.logging namespace fall...