alex kuang

professional yak shaver

Clojure First Impressions

After achieving some measure of familiarity with Scala, and with newfound copious amounts of free time, I decided I wanted to see more of what the functional world had to offer. The obvious choices were Haskell and Clojure; but while Haskell has the upper hand in functional purity and a crazy advanced type system, I like to think I’m a pragmatic guy at heart and Clojure seemed more practical. I haven’t worked with it too extensively, but my experience so far can be summarized by two words: Simple and composable.

The language

Clojure is a refreshingly simple language. Despite my last foray into a Lisp being about half a decade ago, the learning curve was much gentler than I’d expected. Maybe it’s because I was already in a functional programming mindset, but the straightforward syntax and abundance of documentation probably helped. And on a completely subjective level: iDislikeCamelCase, and clojure-case-is-pretty-neat.

The ecosystem

Of course, the overall enjoyability of using a language doesn’t depend solely on the core language, but also the libraries and toolchain available. Most of the libraries I’ve seen keep in line with the design of the language: super lightweight, super simple, super composable, and as a result super easy to ramp up on and use. Theoretically that should just describe all good library design in general, but I feel like the clojure community takes it especially to heart.

Compojure, for example, chose to implement its url destructuring to closely follow the destructuring available in stock Clojure lets expressions. I can’t help but draw the comparison to Scala, where I’d be more likely to find that url decomposition exists only in the form of an exotic DSL. Another huge example for me is the difference between the simplicity of the Clojure build tool Leiningen and the craziness of Scala’s SBT. Sorry SBT–You work very well, but I’d rather not have to google what the <++= operator does every time I touch the build.

With vim

One of my original reasons for leaning clojure was its close integration with LightTable. As it turns out, the functionality I liked could be replicated in vim with fireplace.vim’s quasi-insta-repl and insta-doc, due in no small part to leiningen and nrepl’s awesomeness. Rainbow parentheses is also pretty cool, and has been useful enough that I will probably keep it on even when I don’t have to deal with the hardcore levels of parens in Lisps:


If programming languages could be graded on usability, Clojure would get full marks. It has been a breath of fresh air after dealing with the crazy complexity in Scala. Undoubtedly working through the latter had a part in making the former much easier, and Scala will always have a place with me, but for now I find myself slowly joining the rest of the Clojure bandwagon.