Update: This article was written as an April Fool's joke, taking a stab at the fact that JSON is a closed, dumb, and pretty anemic data format. There are other…
I recently rolled my own Decimal to Roman Numeral converter in Clojure. I was inspired by some tweets about a roman numeral code kata. The Decimal to Roman Numeral converter…
Imagine that you one day were asked to implement the following requirement: "As an Administrator, I want to know what has changed in the database since a given timestamp, and…
This post is the final part of a series of articles about LISP, a function called SUBST, Clojure, and other interesting stuff. You probably want to read the previous posts…
This post is part of a series of articles about LISP, a function called SUBST, Clojure, and other interesting stuff. You may want to read the previous posts before continuing…
This post is part of a series of articles about LISP, a function called SUBST, Clojure, and other interesting stuff. You may want to read the previous post before continuing…
When John McCarthy in 1960 wrote his famous paper on the programming language LISP, he used a particular function to illustrate what you could do with the language. The language…
ShowOff is a presentation software where you create your slides by writing simple text files containing markdown formatting. Styling is done using CSS. The slides are served by a web…
According to this blog entry on Heroku, Clojure becomes the third language officially supported on the Cedar stack, after Ruby and Node.js. They write: - "Clojure combines the expressiveness of…
Heroku is a cloud application platform for Ruby/Rails and Node.js. However, the Cedar stack on Heroku makes it possible to deploy other types of applications. In this blog entry, I will first describe how to write a simple Clojure web app using the Ring library and the build tool Leiningen. Then I will show how to deploy this Clojure web app on Heroku, using nothing but Git. I will make a change and see how to deploy that. I will also show how to easily roll back to a previous release.
In a previous blog entry, I explained the higher-order function sum and how to use the Substitution Model to follow the execution of a function. In this entry, I will use the sum function to perform numerical integration, and in the process run into some pitfalls of Java's BigDecimal. I will show how the language Clojure provides an elegant solution to the "exact quotient cannot be represented" problem of BigDecimal.
Section 1.3 in Structure and Interpretation of Computer Programs is about Formulating Abstractions with Higher-Order Procedures. As an example, the authors use three simple sums: a sum of an integer…
Here's the development of a tiny little macro that is actually pretty useful. The post is quite verbose, because I explain a lot. I want a debug function that first…
I just upgraded my OpenLDAP to 2.4.21 and suddenly I couldn't load an LDIF that we in Spring LDAP have used successfully for years. % ldapadd -Dcn=Manager,dc=jayway,dc=se -wsomepwd -f /tmp/t.ldif…
Also known as the "Divine Quotient", the Golden Ratio was given an almost magical meaning during the renaissance, but it's actually much older than that. Leonardo DaVinci used it. Euclid…