Introduction

Since my last post, I've been playing with the excellent Quil library, a "Clojure/ClojureScript library for creating interactive drawings and animations." Prior to this, I was writing demonstrations using the following scheme:

Introduction

In a prior post, I spent a great deal of time talking about Predator-Prey systems, ordinary differential equations, and solving these equations in Clojure. In this post, I describe a recent project I did that uses the same ODE solver to do something much more fun - implement a physics-based lunar lander game.

Introduction

During a recent code review, a coworker who had the good fortune of jumping straight from Java to Clojure was asking me a few questions about some Scala code she'd been asked to edit. The particular problem involved recursive accumulation of some list data and our conversation drifted towards some questions regarding the different-yet-similar-sounding terms in these JVM languages. Java, Scala, and Clojure together have Null, Nil, nil, Some, and None. Most of these are related in their respective languages to how exceptional behaviors are handled with respect to references and/or collections. Here I explain each of these from the perspective of their host languages and my opinion of the effectiveness of each solution.

Introduction

I was recently browsing some links from my Twitter feed and came across some programming exercises and their solutions. I selected a few that I thought were interesting, solved them, and now I want to present my solutions here along with some commentary on how they were solved. I think the solutions and especially their comments might be helpful to new Clojurists as well as Java developers who are looking for some examples of why Clojure code is so much more concise. Without further ado, here they are.

Earlier this year I gave a presentation at work entitled "Functional Programming (FP) from the Fire Hose." My goal was to present, to a mostly OOP audience, some of the basics of FP while also providing examples that show that FP isn't just academic. You can't sell people on FP with concepts alone. People's eyes just glaze over and roll back into their heads when you start talking functional concepts like first class and higher order functions, immutability, statelessness, referential transparency, homoiconicity, and the like (I won't even say the M-word). With that in mind, I tried to go fast on FP and show several clear examples that demonstrate FP in action, even at a very small scale.

In my presentation, I do (or attempt to do) the following: