I like Lispy languages. One I’ve been playing with – and occasionally been using for smaller projects – is Clojure. Clojure projects usually use Leiningen for their build system. There are generally two ways to install leiningen – just download the script as per the Leiningen web site, or use the OS package manager. I usually prefer using the OS package manager, but Manjaro doesn’t include leiningen as a package in its repositories. Installing leiningen is pretty easy via the package manager and I’ll show you how.
Uncle Bob Martin discovered Clojure fairly recently and really, really likes it. Having had the privilege to see him speak at various SD West conferences back when they still were a thing, I wasn’t surprised by this. Anyway, do yourself a favour and spend a few minutes reading the article. It’s worth your time.
I also strongly agree with him that reading Structure and Interpretation of Computer Programs is very much worth the effort. It is a very well written book, especially as computer science textbooks go. It’s not going to land you a new job with the latest hotness in technology, but it will help you improve your knowledge of computer science fundamentals. Those fundamentals are allow you to build a long term career and going from an “XX programmer” to a well rounded software engineer.
Lisp dialects like Clojure have a very rich set of algorithms that can present altered views on containers without modifying data in the underlying container. This is very important in functional languages as data is immutable and returning copies of containers is costly despite the containers being optimised for copy-on-write. Having these algorithms available prevents unnecessary data copies. While I am not going into mutating algorithms in this post, the tradition of non-modifying alghorithms that work on containers leads to an expressiveness that I often miss in multi-paradigm languages like C++. As an example I will show you how to use a filtered container view in C++ like you would in Clojure.
I’ve recently been working in Clojure on some code that really benefits from parallelization but doesn’t need to squeeze the last available cycle out of the machine.
Of course, if you’re using Clojure, you’re also using Leiningen as the universal build and configuration system. Accept no substitute. Now if I could only remember the syntax to run a single test when I’m refactoring some code and need to reflect the changes in the test suite via the build system and not just from inside the REPL?
Ah, here it is:
lein test :only TestNS/function
This is of course self-explanatory if one’s brain is running in clojure mode and not only the editor.