Things Ian Says

Breadth First Graph Traversal in Clojure (Kiwiland Example)

In my previous article, I looked at how to create a graph in Clojure, and find the length of various journeys within it. I will now move on to look at how to search the graph, to solve some of the other questions in the Kiwiland Trains Programming Challenge. This will focus primarily on the implementation of a breadth first search.

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Building a Graph in Clojure, for the Kiwiland Railway

I was recently looking at a programming test, where the challenge is to represent a railway system (called “Kiwiland”) and then deduce various facts about it (for example the distance for a certain route). I wanted to develop this in Clojure, and thought it would be an interesting thing to work through on my blog.

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Kiwiland Railway Problem Statement

This is a statement of the problem I am working through in the following articles: Building a Graph in Clojure Breadth First Graph Traversal in Clojure Note that this is taken from github.com/coop/kiwiland. Problem Statement The local commuter railroad services a number of towns in Kiwiland. Because of monetary concerns, all of the tracks are ‘one-way’. That is, a route from Kaitaia to Invercargill does not imply the existence of a route from Invercargill to Kaitaia.

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A Clojurescript API Server in Docker using ExpressJS

I have been writing code in Clojure for some time, most recently running it in Docker containers on Kubernetes. This approach has been primarily for ease of testing and deployment, rather than for scaling. However, now I am looking at applications where I want to start scaling out dynamically, and I started to get a bit concerned about the startup time of my containers — the JVM that Clojure runs on, can take a bit of time to get out of bed. Since ClojureScript allows us to compile Clojure into Javascript, I took a look at running ClojureScript in NodeJS.

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