Welcome to “stupid jj tricks”. Today, I’ll be taking you on a tour through many different jj configurations that I have collected while scouring the internet. Some of what I’ll show is original research or construction created by me personally, but a lot of these things are sourced from blog post, gists, GitHub issues, Reddit posts, Discord messages, and more.

A Jujutsu tutorial that requires no previous experience with Git or other version control systems.

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.

In functional programming,
combinator libraries refer to a design style that emphasizes bottom-up program construction.
Such libraries define a few core data types
and provide constructors—functions that create initial objects—and combinators—functions that build larger objects from smaller pieces.

Combinators enable the programmer to use intuitive visual and spatial reasoning
that’s vastly more powerful than linear language processing.
As a result, solving problems with combinators feels like playing with lego pieces.

Extra is different than More. Extra is finishing those two screens, but then researching a new library for form validation that might reduce the boilerplate code. Or it's learning ways to protect against common security vulnerabilities from data entry. These little off-ramps from the main highway of Normal Work could be dead-ends and not have any practical value to the project. But they might also be important contributions. And that's the thing with Extra. While the tangible value to the project is uncertain (it could be nothing this time or it could be something), the value to you is real.

Reading through the Emacs 30 NEWS file and picking
out the stuff I think is the most interesting.

A somewhat compact implementation of the awk programming language

A fun, hands-on guide to writing your own compiler for a real-world programming language.

This article presents the program earlyoom to prevent a Linux system to lock up in low memory situations.

soju is a user-friendly IRC bouncer. soju connects to upstream IRC servers on behalf of the user to provide extra functionality. soju supports many features such as multiple users, numerous IRCv3 extensions, chat history playback and detached channels. It is well-suited for both small and large deployments.