Introduction

In this book, we will go on a journey through the broad land of algorithms and data structures, taking a ride on the comfortable vehicle that is Clojure programming language.

First, we will take a look at arrays, exploring their particular structures to tackle problems as interesting as compression, fractal drawing, multithreading, and call stacks.

Then we will elaborate on linked lists, transforming them in to doubly linked lists. We will do this to speed up access to their elements, build parsers, and devise fast random access.

The next step of our trip will concern trees of data. We'll show you how to implement self-balancing red-black trees, how to design efficient key-value stores — thanks to B-trees (way to go in order to design undo-capable text editors), and lastly, a methodology to construct autocomplete text typing systems.

After that, we'll focus on exploring some optimization and machine-learning techniques. We will see how to set up a recommendation engine, the way to go to optimize a problem where costs and profits are involved, a methodology to find the best possible paths in graphs, and how to summarize texts.

Then we'll study the topic of logic programming, analyzing some website traffic logs to detect visitors of interest to us. Doing this, we'll dive into the problem of type inferencing for the Java language, and simulate a turn of a checkers game.

At that point, we'll talk about asynchronous programming as a means of tackling difficult problems. We'll build a tiny web spider, design an interactive HTML5 game, and design a complex online taxi-booking solution.

The last rally point of this trip, but certainly not the least, is that we'll have a look at the higher order functions and transducers at the heart of Clojure. We'll design a recursive descent parser using a trampoline, build a reusable mini firewall thanks to transducers, and lastly, explore the continuation passing style as a tool to design a simple unification engine.

This will be quite a tour, in which we will bring to life various real-world use cases related to the essential theory of computing as far as data structures and algorithms are involved, which are all served by the high expressive power of Clojure. By the end of this book, you'll be familiar with many of the advanced concepts that fuel most of the nontrivial applications of our world while you enhance your mastery of Clojure!