Book Image

The Clojure Workshop

By : Joseph Fahey, Thomas Haratyk, Scott McCaughie, Yehonathan Sharvit, Konrad Szydlo
Book Image

The Clojure Workshop

By: Joseph Fahey, Thomas Haratyk, Scott McCaughie, Yehonathan Sharvit, Konrad Szydlo

Overview of this book

The Clojure Workshop is a step-by-step guide to Clojure and ClojureScript, designed to quickly get you up and running as a confident, knowledgeable developer. Because of the functional nature of the language, Clojure programming is quite different to what many developers will have experienced. As hosted languages, Clojure and ClojureScript can also be daunting for newcomers because of complexities in the tooling and the challenge of interacting with the host platforms. To help you overcome these barriers, this book adopts a practical approach. Every chapter is centered around building something. As you progress through the book, you will progressively develop the 'muscle memory' that will make you a productive Clojure programmer, and help you see the world through the concepts of functional programming. You will also gain familiarity with common idioms and patterns, as well as exposure to some of the most widely used libraries. Unlike many Clojure books, this Workshop will include significant coverage of both Clojure and ClojureScript. This makes it useful no matter your goal or preferred platform, and provides a fresh perspective on the hosted nature of the language. By the end of this book, you'll have the knowledge, skills and confidence to creatively tackle your own ambitious projects with Clojure and ClojureScript.
Table of Contents (17 chapters)
Free Chapter
2
2. Data Types and Immutability

Introduction

In the last chapter, we built our application layer and interacted with it via the REPL. This works sufficiently well for a single user performing ad hoc interactions, but it does not scale. Indeed, we could imagine a scenario where a third party or even another of our own services wants to make use of the data stored in our database, perform calculations, and persist updates. This interaction would be programmatic and would, therefore, benefit from being exposed over HyperText Transfer Protocol (HTTP) or similar.

We can achieve this by exposing our application layer via a web service. A web service allows interaction with our application layer over a network (most typically the internet, although it could be over an intranet for private applications).

To build our web service, we'll need a web application library to build our API, a web server to serve it up over HTTP, and a routing library to route incoming requests to the appropriate handler. Clojure has...