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.

Things we wish we didn't know

This post is all about speculative compilation, or just speculation for short, in the context of the JavaScriptCore virtual machine.

Every so often I come across a paper, blog post, or (occasionally) video that completely changes how I think about a topic in programming languages and compilers. For some of these posts, I can’t even remember how I thought about the idea before reading it—it was that impactful.

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

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.

Featureful zsh prompt.

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

Last year I finally decided to learn some Rust. The official book by Steve Klabnik and Carol Nichols is excellent, but even after reading it and working on some small code exercises, I felt that I …

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