I started writing this post because, for whatever reason, I keep forgetting what the difference is between a ring and a group, which is funny to me because I never forget the difference between a semiring and a semigroup – although other people do, because it’s quite easy to forget! So, I wanted a fast reference to the kinds of algebraic structures that I am most often dealing with in one way or another, usually because I’m writing Haskell (which has some reliance on terminology and structure from abstract algebra and category theory) or I’m trying to read a book about category theory and they keep talking about “groups.” Wikipedia, of course, defines all these structures, and that’s fine, but what I need in those times is more of a refresher than an in-depth explanation.

This web app displays notes and slides in separate windows,
keeping both synchronised.
It accepts simple, double-width, or double-height PDF presentations:

Things we wish we didn't know

I have a lot of thoughts about the design of compiler intermediate representations (IRs). In this post I’m going to try and communicate some of those ideas and why I think they are important.

In modern Java, the visitor pattern is no longer needed. Using sealed types and switches with pattern matching achieves the same goals with less code and less complexity.

plainweb is a framework using HTMX, SQLite and TypeScript for less complexity and more joy.

Sales pitches are the only place where “self-serve dashboards" work. In the real world, it's a different story.

Why "business" people don't use metabase/power-bi.

I've been running NetBSD on a RockPro64 since NetBSD 10-BETA, and I'm still happy with it now with NetBSD 10-RELEASE. I'm always looking for hardware to hack NetBSD though, and I recently watched a FOSDEM 2024 video: NetBSD 10: Thirty years, still going strong!. The Pinebook Pro laptop was mentioned at one point, which has the same RockChip SoC as the RockPro64. That reminded me I'd been wanting to give this inexpensive ARM 64 laptop a try.

Living specification of the IRC protocol. Does not include brand new behavior, just existing behavior present in IRC software and/or networks (new extensions are IRCv3's area).