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.

I feel uneasy about design patterns.
On the one hand, my university class on design patterns revived my interest in programming.
On the other hand, I find most patterns in the Gang of Four book to be irrelevant to my daily work;
they solve problems that a choice of programming language or paradigm creates.

My litmus test of a good design pattern is its cross-disciplinary applicability.
I’m more likely to accept an idea that pops up in fields beyond software engineering.
And the most convincing patterns are the ones that help me in everyday life.

This article describes a universal pattern that billions of people rely on daily, but software engineers rarely discuss—the plan-execute pattern.

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.

A well-equipped ASCII diagram builders freely available on the internet.
It stresses portability, simplicity, and immediateness.

Storage for private, distributed, offline-first applications. Earthstar is a specification and JavaScript library for building connected applications owned and run by their users.

This blog series creates a small operating system in the Rust programming language. Each post is a small tutorial and includes all needed code.

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

The expression problem describes how most types can easily be extended with new ways to produce the type or new ways to consume the type, but not both. When abstract syntax trees are defined as an algebraic data type, for example, they can easily be extended with new consumers, such as print or eval, but adding a new constructor requires the modification of all existing pattern matches. The expression problem is one way to elucidate the difference between functional or data-oriented programs (easily extendable by new consumers) and object-oriented programs (easily extendable by new producers). This difference between programs which are extensible by new producers or new consumers also exists for dependently typed programming, but with one core difference: Dependently-typed programming almost exclusively follows the functional programming model and not the object-oriented model, which leaves an interesting space in the programming language landscape unexplored. In this paper, we explore the field of dependently-typed object-oriented programming by deriving it from first principles using the principle of duality. That is, we do not extend an existing object-oriented formalism with dependent types in an ad-hoc fashion, but instead start from a familiar data-oriented language and derive its dual fragment by the systematic use of defunctionalization and refunctionalization. Our central contribution is a dependently typed calculus which contains two dual language fragments. We provide type- and semantics-preserving transformations between these two language fragments: defunctionalization and refunctionalization. We have implemented this language and these transformations and use this implementation to explain the various ways in which constructions in dependently typed programming can be explained as special instances of the phenomenon of duality.

There’s plenty of information out there on how to scale Django to handle numerous requests per second, but most of it…

piku, inspired by dokku, allows you do git push deployments to your own servers, no matter how small they are.

Hare is a systems programming language designed to be simple, stable, and robust. Hare uses a static type system, manual memory management, and a minimal runtime. It is well-suited to writing operating systems, system tools, compilers, networking software, and other low-level, high performance tasks.