Bret Victor’s talk Inventing on Principle (video, transcript) changed the way I think about computing in 2019. Inventing on Principle is partly about Bret’s guiding principle:

“Creators need an immediate connection to what they create. And what I mean by that is when you’re making something, if you make a change, or you make a decision, you need to see the effect of that immediately.”

The Edit-Compile-Run Cycle

Although Bret doesn’t use the term, programmers are deeply familiar with his principle. We’ve all worked with toolchains that introduce significant delay before you can “see” the results of a change, and we know they’re painful. Everyone wants a short edit-compile-run cycle.

But until IoP, I’d assumed that slow cycles wouldn’t materially change the output – you’d eventually get to the same place. This was wrong. I also didn’t appreciate the very small time scales involved; a 5 second delay used to seem trivial to me, but it’s still meaningfully different from a response time measured in milliseconds.

Through some very impressive custom tools, Bret shows how immediate feedback enables exploration, which then gives birth to ideas which would otherwise never see the light of day. This was an epiphany for me. Since IoP I’ve constantly been looking for better ways to code, and re-evaluating my existing processes for shorter feedback cycles. The results:

Rust

My typical Rust development workflow goes something like this:

1. Write a small function that does roughly what I want
2. Write a small unit test inline to exercise the function (even if it’s a private function)
3. Iterate using cargo test until the function is correct
4. Later, “productionize” the tests if necessary

Rust’s native support for inline unit tests helps a lot here, and the excellent type system catches a lot of issues before I even run cargo test. On the other hand, Rust’s compiler is notoriously slow and that extends to IDE tooling that depends on the Rust Language Server. I’m looking forward to Cranelift for faster debug builds.

I’ve been busy for the last month, and I completely forgot to update the blog. In no particular order, here’s what’s been occupying my time lately:

Coworking

I joined a coworking space in East Vancouver with a friend, and I’m working from there 3-4 days/week. It’s like an airy spacious café with fast internet and quiet space, I love it. I find that getting out of the house helps me be more disciplined with my working hours; I’m much less likely to disappear down a Wikipedia+YouTube rabbit hole at the office. And then when I inevitably do that at home, I feel less guilty about it because I’ve accomplished so much at the office.

Node.js

I got really into Node and the modern back-end JS ecosystem.

javascript.info has been remarkably helpful (I can finally remember exactly what a closure is!), it might be the first .info website that is genuinely a great source of information.

This talk by Franziska Hinkelmann on the V8 team is a great overview of JS engine internals.

I’ve been pleasantly surprised by Node APIs a few times; the Cluster module makes it trivial to fork workers and take advantage of multiple cores, and Buffer+friends make low-level bit manipulation quite pleasant. Which leads me to:

Cryptopals

The Cryptopals Crypto Challenges by Matasano Security are a delightful introduction to practical cryptography. I decided to do them in Node to get more practice with back-end JS, my solutions are on GitHub. The problems are very well-designed. They’re small enough that you can (usually) do each one in a single sitting, and it feels great every time you decode a ciphertext.

Raspberry Pi

I bought a Raspberry Pi 4 and have been loving it. For some reason I always thought of the Pi as only relevant for education and hardware hackers, but I was wrong – it’s a remarkably capable little Linux machine. I’m currently turning mine into a private Dropbox clone using ownCloud.

Anki

I started using Anki flashcards. I have decks for Node internals, uncommon JS syntax, and infrequently-used keyboard shortcuts and CLI options. Creating cards is a bit of an initial investment, but once that’s done I find that 5 minutes of daily study is enough.

I spent a few weeks in August rewriting this website, and as promised here are the deets. The source code is available here under the MIT license.

Background

When I initially put this website together in January 2018, I used Julio Pescador’s Hugo port of the Future Imperfect theme. I’d heard good things about Hugo, I wanted to write blog posts in Markdown, and it was a good-looking theme that required minimal additional setup. It served me well for over a year, but a few things kept bothering me:

1. The styling was very difficult to modify – it was nearly 3000 lines of CSS in a single file, with many duplicated colours and styles.
2. The theme relied on a lot of JavaScript libraries: jQuery, highlight.js, Fancybox, Skel…
   1. My simple static website was serving up hundreds of kilobytes of largely unnecessary scripts. As someone who grew up using a dialup modem, this offended me.

My goal was to rewrite the Hugo theme for extensibility and performance, and I figured it would take maybe a week. Of course, it took about 3 times that.