Published on 2026-08-17
]]>Published on 2026-08-17
Tags: photography, seattle
Published on 2026-08-17
]]>Published on 2026-08-17
Tags: photography, seattle
Published on 2026-08-16
]]>Published on 2026-08-16
Tags: article, commentary, llm, ocaml, software-eng, software-eng-auto
termaid, my OCaml port of mermaid.rs, is available on opam! π With that release, the work shifts to maintenance.
Given that this is a machine-driven port of an existing piece of code, I wanted to set up some infrastructure so that I'd catch any upstream bug fixes or feature enhancements. So I added an upstream-check.yml GitHub Actions workflow to execute check_upstream.sh and file an issue when it spots a change. The script uses the commit and blob references in oracle/UPSTREAM to determine changes against upstream. When the check fires, I'll ask an agent to update the oracle to the new upstream HEAD, use the oracle to generate test cases relevant to the changes, and adjust the OCaml code to make the tests pass.
Published on 2026-07-21
]]>Published on 2026-07-21
Tags: article, llm, ocaml, rust, software-eng, software-eng-auto
I saw this post from Simon Willison about running mermaid.rs β a utility from Grok Build, xAI's newly open-sourced coding agent harness, as WebAssembly in the browser. The output looks really nice, the Rust code is very self-contained, and I thought it would be interesting to use an agent to convert it to OCaml. The outcome is termaid, a minimal-dependency OCaml library for rendering Mermaid diagrams.
The package contains a minimal binary that renders a diagram from stdin, alongside the library itself, for use in other programs. Supported diagram types: flowchart/graph, stateDiagram, classDiagram, erDiagram, and sequenceDiagram.
$ termaid <<'EOF'
sequenceDiagram
A->>B: ping
B-->>A: pong
EOF
βββββ βββββ
β A β β B β
βββ¬ββ βββ¬ββ
β β
β ping β
βββββββΆβ
β β
β pong β
ββββββββ€
β β
βββ΄ββ βββ΄ββ
β A β β B β
βββββ βββββ
Published on 2026-07-11
]]>Published on 2026-07-11
Tags: listening-to, music
Acid techno, drum and bass, inject it into my veins!
]]>Published on 2026-07-11
]]>Published on 2026-07-11
Tags: commentary, llm, quote, security, society, software-eng
It is really unfortunate that, in order to make sure my compiler isnβt going to produce incorrect codegen, this trips the safety guards. I guess that simply saying βhey this is a toy language nobody uses and so itβs fine Iβm not hacking anyoneβ and that not allowing me around the guards is a βgoodβ thing, but at the same time, it is unfortunate if these policies end up making it so that individuals like me canβt make my software as robust as products from large organizations.
I think this kind of "alignment", where "sensitive" topics are identified and the model is immediately cut off, is harmful. I'm reminded of my Unrestricted LLM Interaction is Unsafe post β I remain skeptical that you can foolproof these kinds of "alignment" checks such that they are unbreakable. As a result, they are security theater. Determined people can get past the blockages if they try hard enough, while these checks shut down legitimate uses like Klabnik's.
]]>Published on 2026-07-11
]]>Published on 2026-07-11
Tags: article, commentary, javascript, kotlin, llm, software-eng, software-eng-auto
OpenAI GPT-5.6 Announcement on 2026-07-09:
GPTβ5.6 can write and run lightweight programs that coordinate tools, process intermediate results, monitor progress, and choose the next action as work unfolds. This lets tool-heavy tasks advance with fewer tokens, fewer model round trips, and less guidance. Instead of requiring developers to script every step or passing every tool response back through the model, Programmatic Tool Calling in the Responses API can filter large amounts of intermediate data, retain only what matters, and adapt its workflow along the way.
I am getting some sweet validation from this feature they revealed. I built a similar system at work recently, and I think it fits coding agent capabilities nicely.
]]>Published on 2026-07-09
]]>Published on 2026-07-09
Tags: listening-to, music
Grungey, shoegazey rock.
]]>Published on 2026-07-09
]]>Published on 2026-07-09
Tags: article, documentation, macos, ocaml, software-eng
The OCaml.org opam documentation process does not trigger for macOS-only packages, leaving ones like osx-keychain labeled as "β οΈ No Docs".
I couldn't find a mention of this in the official documentation. In 2022, OCaml.org started serving automatically generated documentation for applicable opam packages, making use of a new ocaml-docs-ci documentation pipeline. Earlier this year, OCaml.org upgraded to odoc 3, accompanied by updates to ocaml-docs-ci for odoc 3 compatibility.
ocaml-docs-ci explicitly targets Linux platforms only. Because osx-keychain declares available: [ os = "macos" ], opam treats it as unavailable on ocaml-docs-ci's Linux workers, filtering it out of the set of packages docs-ci considers buildable before even attempting a build.
Published on 2026-07-06
]]>Published on 2026-07-06
Tags: listening-to, music
Lofi hiphop, very chill. I love the Sailormoon album cover.
]]>Published on 2026-07-06
]]>Published on 2026-07-06
Tags: code-review, commentary, llm, quote, software-eng, software-eng-auto
XP compressed feedback loops until truth became unavoidable. Tests replaced promises. Continuous integration replaced status reports. Working software replaced narrative. You could no longer hide behind process because the system itself reported your progress, loudly and continuously.
The practices that looked like chaos were actually mechanisms for enforcing honesty. Pair programming meant every line of code had a witness. Test-first meant you couldn't ship wishes. Short iterations meant you couldn't hide. The discipline was more demanding than what came before, not less. It just didn't look like the discipline people were used to seeing.
I really enjoyed this article. The first paragraph spoke to my initial experiences with Agile and Pair Programming, though I was second-generation, learning from folks who had worked with Ward Cunningham and Ron Jeffries. The mentions of chaos and shifting of discipline immediately pinged my coding agent radar, so I was delighted to see the article turn that direction at the end of the intro.
]]>Published on 2026-07-05
]]>Published on 2026-07-05
Tags: hardware, software-eng, til
Wikipedia apparently has a 31-entry category, dedicated to the computer architecture "laws" (statements/conjectures/principles) people have coined. Inside I found Haitz's Law, the LED counterpart to Moore's Law: "every decade, the cost per lumen (unit of useful light emitted) falls by a factor of 10, and the amount of light generated per LED package increases by a factor of 20, for a given wavelength (color) of light."
]]>Published on 2026-07-04
]]>Published on 2026-07-04
Tags: listening-to, music
Their music always reminds me of summer, especially the way Rania Woodard sings.
]]>Published on 2026-07-04
]]>Published on 2026-07-04
Tags: article, macos, ocaml, security, software-eng, static-site
The osx-keychain library I built to natively pull credentials from the macOS keychain was accepted into Opam and is now publicly available as a dependency, a first for me π₯³. Here is some context on why I made it:
There are two modes in which I interact with AWS for the alexleighton.com static site: during site upload, and during image upload.
I used to rely on GitHub Actions to build and deploy all commits on the main branch, but it ended up being the worst of all worlds. Reinstalling opam, dune, the OCaml compiler, and all dependencies often took over 10 minutes, regardless of the Actions-caching I tried to apply. My static site is a private repository, so GitHub eventually started nagging about reaching the 1000 monthly build hours threshold for private repos. As a result I turned off the automation and have been building/uploading my site straight off my laptop using a bash script that does what the Action did.
Published on 2026-07-01
]]>Published on 2026-07-01
Tags: listening-to, music
Psychedelic synthwave. The Emptylands track is powerful; wear headphones.
]]>Published on 2026-07-01
]]>Published on 2026-07-01
Tags: changelog, ocaml, static-site
Image variants are now served from a CDN at img.alexleighton.com instead of being bundled into the site and served by Amplify.
It seems I never came back to detail the custom image system underlying the images on this static site, so let's begin with the before, to motivate the after. The image system comprises a private S3 bucket, local filesystem cache, image "database", and an image system library.
The image system library is written in OCaml and integrated into the static site generator, to allow image reference resolution. A separate executable fronts the image system, to allow uploading and syncing of images during post authoring. Image upload through the system generates a number of variants of different sizes and formats (jpeg as the lowest common denominator, webp for most browsers, avif for modern browsers), assigns a TypeId to each image, uploads the images to the source-of-truth private S3 bucket, adds them to the filesystem cache, and adds corresponding rows to the CSV image database. The site generator reads the image database to dereference image TypeIds into source URLs, copies every referenced image into the output directory, and includes those images in the release artifact.
Published on 2026-06-29
]]>Published on 2026-06-29
Tags: photography, seattle
Published on 2026-06-27
]]>Published on 2026-06-27
Tags: changelog, static-site
There's now a Listening page: a feed of every listening-to-tagged post, showing the track title, artists, my commentery, and a link to play it.
Like the Photos page, the feed is assembled entirely from existing template builtins β setlist to gather the tagged posts and foreach to render each row β reading from a music frontmatter:
---
...
music:
artist: [Ninajirachi]
title: I Love My Computer
kind: album
source: bandcamp
url: https://ninajirachi.bandcamp.com/album/i-love-my-computer
commentary: |-
A love letter to computers and video game sounds in the best way.
---
Published on 2026-06-20
]]>Published on 2026-06-20
Tags: listening-to, music
Edgy, thumping bass.
]]>Published on 2026-06-20
]]>Published on 2026-06-20
Tags: commentary, java, kotlin, quote, software-eng
Wonderfully in-depth article on the history and technical details of "value objects" arriving in JDK 28. Very much worth a read.
]]>Artur Skowronski on 2026-06-18:
On June 15, Oracle engineer Lois Foltan confirmed what a good chunk of the industry had stopped believing: JEP 401: Value Classes and Objects will be integrated into the main OpenJDK repository and is targeting JDK 28.
...
Why do I call this one of the biggest changes in the platformβs history? Because Valhalla doesnβt bolt yet another feature onto the language; it moves its deepest assumption. βEvery object has identityβ had been true in Java since 1995; itβs the foundation everything else stood on. Letting the programmer opt out of that assumption (choose which objects need identity and which donβt) isnβt a refactor, itβs a shift of the foundation. And thatβs exactly why it unlocks a whole decade of further work: unifying primitives and objects, specializing generics, denser collections, faster numerics.
Published on 2026-06-20
]]>Published on 2026-06-20
Tags: commentary, llm, software-eng-auto
I mentioned the following finding to a friend recently but hadn't posted about it here, so rectifying that.
]]>Sonnet 4.5 is the first model we've seen that is aware of its own context window, and this shapes how it behaves. As it approaches context limits, we've observed it proactively summarizing its progress and becoming more decisive about implementing fixes to close out tasks.
This "context anxiety" can actually hurt performance: we found the model taking shortcuts or leaving tasks incomplete when it believed it was near the end of its window, even when it had plenty of room left.