Janet for Mortals

You’ve probably seen this Python 101 thing before: @memoized def fib(n): if n 1: return n return fib(n - 1) + fib(n - 2) Leaving aside the absurdity of computing Fibonacci numbers recursively, it’s a common first introduction to Python decorators and higher-order functions. fib is just a function, and memoized takes that function and returns a...

The reason I discovered an ancient blog post the other day was that I had something new to say about Nix for the first time in over two years. The thing I want to say is this: nix-direnv is great. It fixes roughly every problem that I’ve had with nix-shell, and does so in a much nicer way than my previous ad-hoc solutions. This is important...

Note: I wrote the vast majority of this post on August 24, 2022, but I decided that it was a whiny rant that I didn’t want to publish. I came across the draft in January 2024, remembered that this entire series is a whiny rant, and decided to publish it anyway. I’ve been a happy Nix user for about 18 months now, and– well, not happy happy, but...

When you think about the Fibonacci sequence, you probably imagine a swirling vortex of oscillating points stretching outwards to infinity: Okay, no, obviously you don’t. Yet. When you think about the Fibonacci sequence, you probably flush with a latent rage when you remember that it is, more often than not, the way that we introduce the concept...

I want to tell you about an idea that has had a huge influence on the way that I write software. And I mean that in the literal sense: it’s changed the way that I write software; it’s re-shaped my development workflow. The idea is this: you can write programs that modify themselves. And I don’t mean macros or metaprogramming or anything fancy...