My name is James Kay. I like syntax, semantics, programming languages, natural languages, formal verification, and other things, and I work in the tech industry.

September, 2023

Nix patterns I

separate your inputs and outputs

Introduction §

I’ve been using Nix and NixOS for many years now, both personally and professionally, on workstations and servers. While the tools aren’t without their warts, I strongly believe the model espoused by Nix for package management is a leap ahead of other available tools. However, the Nix language can be very unstructured, and knowing how to use it in an effective and composable way can involve a lot of searching and deep-diving through nixpkgs. This series aims to collect patterns and good practices I encounter or devise, significantly for my own future benefit, but hopefully other people will find it helpful too.

August, 2023

The art of binding

variables made complicated

Introduction and pedantry §

In programming, we typically think of a variable as a location to store a value. It turns out this is mostly an implementation detail; if we generalize them into their interface, we find a rich space of languages that captures the distinctions between several different types of programming language that seem very different at first glance.

February, 2023

λ-calculus for programmers

programming language fundamentals

Introduction §

If you’ve done much functional programming, you’ve probably heard of the λ-calculus, invented by Alonzo Church in the 1930s. If you haven’t, the term might be quite new to you; but don’t worry, despite the intimidating name the λ-calculus is actually very simple.

January, 2023

Linear types for programmers

reasoning about resources

Introduction §

Linear types are an application to type theory of the discipline of linear logic, first described by Jean-Yves Girard (Girard, 1987). Since its inception it has led to many fruitful discoveries in computer science. In this article I hope to explain why it is so interesting, as well as relate it to concrete tools and practices available to programmers today.

November, 2021

Site design & construction

philosophy and realization

Design §

I often focus too hard on the design of websites to the detriment of the content, so the design of this site was intended to front the content. Originally I didn’t even have a title on pages, but I’ve never been able to pass up the opportunity for a subtitle…

October, 2021

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Lorem ipsum §

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