This is Matt Widmann's site for working notes and articles. I'm a programmer so I tend to write about software, but I also love nature, bicycles, and writing.

1. Updates for April 2026

   30 April 2026

   Here's what I've been working on, doing, and thinking about this month.

   • I upgraded this site's generator for Zig 0.16 and made it multithreaded.

   • I went on a business trip to London for two weeks, staying in the central part of the city, close to the Tower Bridge. While I worked during the week, I still had four days on the weekend for sightseeing in the city and trips to Cambridge and Bletchley Park¹¹ This is where the ciphers used by Axis powers in World War II were broken using early computers..

   • A notebook that lays flat was my first photo-rich article. Despite the low-quality photos, it's nice to share what my setup looks like.

   I did not read nearly as much as I did last month, but I did find time for one fun science-fiction book:

   • Project Hail Mary by Andy Weir

   Instead, I read some excellent articles:

   • Go Ahead and Use AI. It Will Only Help Me Dominate You.

     This was hilarious and a testament to writing in your own voice without the help of LLMs.

   • Your hex editor should color-code bytes

     I have some strong opinions about syntax highlighting and this is a neat application of it. I'd like a hex editor with structural grouping for known-formats, since I almost always use them on file data. But this looks really useful for hex editing arbitrary data.

   • A tail-call interpreter in (nightly) Rust

     I wish there was some way to apply this to the work I do in Swift, where I built a little arithmetic expression evaluator for the CPU Counters instrument. To be fair, I haven't actually looked at the generated code and I'm likely leaving a lot of performance on the table. Byte code VMs are a really effective solution to some hairy problems and can be competitive with native code in some cases.

     Andy Wingo wrote the value of a performance oracle as a follow-up, showing that his WebAssembly runtime isn't as slow as Wasmtime. I'm still not convinced that there are not fundamental limits to performance, having re-read the WebAssembly Troubles series recently. And as much as I love the Uxn ecosystem, his take that a Uxn interpreter is a viable target to optimize for is a little odd. There are veritable loads of more commonplace workloads available in languages that can target WebAssembly.

   • Porting Mac OS X to the Nintendo Wii

     Seriously impressive. This might be the one of the last pieces of greenfield IOKit development to happen outside of Apple.

   • 256 Lines or Less: Test Case Minimization

     This is a nice demonstration that you don't need to be too fancy to get 80 to 90 percent of the benefit of an idea. The problem I've faced with property-based testing is finding useful invariants for a data structure or algorithm that can be easily checked. But I also didn't have access to convenient generation libraries.

   • Lua can be a really cool HTML templating engine

     I love a tactical Lua interpreter as much as the next person, but I'm not convinced that a DSL for HTML is a great application for it. Regardless, I appreciated how the code was presented and discussed. It's almost like a literate program, but positioned as a persuasive piece.

   Before my trip to London, we put on a little Easter egg hunt for my daughter in our backyard and, the next day, another one at my aunt's house. My aunt cleverly assigned each kid an egg color so they all got a set number of their own.

   While I was in London, I experienced a busy, built-up, very old, dense city and got around almost exclusively on their underground light rail and regional heavy rail systems. Getting from Heathrow airport to the middle of the city was fast and relatively convenient: the Elizabeth line was busy but not too bad. Being able to tap-to-pay everywhere took the stress away from finding a kiosk or getting some London-specific card.

   Now that I'm back home, I'm taking a week off work to spend time with my family and do some spring cleaning.

2. A notebook that lays flat

   11 April 2026

   I'm a fan of computers. Taking notes on them brings a lot of benefits: easy backups, syncing across devices, search, and invisible revisions. But for thinking through problems and tracking my daily thoughts, I've recently moved away from using note taking apps¹¹ Like iA Writer or Obsidian..

   Writing by hand helps me organize my ideas and avoid the tendency to get bogged down in revisions. Handwritten notes in meetings aren't susceptible to a computer's distractions. Using a pen, they're also immutable and capture how your thoughts evolve over time.²² To bring that to my computer notes, a script commits my notes to version control every 5 minutes. But it's not the same and way less legible. It's also fun for me to work on my handwriting and flip through pages of a well-used notebook. That's probably the biggest reason I've switched: I just like them more.

   

   I've gone through a lot of notebooks that don't work well for me:

   • Hardbound notebooks (e.g. Moleskine and Leuchtturm) are fine for the first dozen pages but soon stop laying flat and require "breaking" the binding to work the book in.

   • Spiral-bound notebooks (e.g. Marumans Mnemosyne) lay flat but their wires get bent and caught up in a crowded bag. Because there's play in the holes for the wires, pages on the inside can get bent on the edges when the cover is offset.

   • Disc notebook systems (e.g. Circa) have all the drawbacks of spiral bound except they're very durable. I used these in college and generally liked them because they were cheap to refill and I needed a full letter size page for taking notes with diagrams.

   • Notebooks with no spine (e.g. Field Notes) don't lay flat and can't fit much paper in them, but they're very portable.

   However, I finally found a style of notebooks I'm happy with. I bought a JetPens Kanso Noto at the end of last year and started using it as a journal. This is a lay-flat notebook with a mostly exposed spine: instead of a continuous cover, there's only some tape to hold the two cardstock covers together.

   

   A5 notebooks are the best size for me. There's enough room on the page for readable paragraphs at my typical handwriting size. It's also portable enough to throw in a small bag or front pocket of a backpack.

   I use a LAMY Safari fountain pen with a fine nib and De Atramentis Document ink in black. The Kanso's Tomoe River paper is pretty thin but handles it well. There's a little ghosting on the other side of pages, but it doesn't hurt legibility. Another color can be used for emphasis and makes it easy to spot edits. The cyan color of this ink bled through badly, which was a shame, but black and red are fine.

   

   It's not as durable as a hardbound notebook, so I eventually wrapped it in a BKxAP Canvas Cover³³ I guess this would address my issues with spiral-bound notebooks, too.. The canvas is soft enough to still let the notebook lay flat. It helps keep the sides of the notebook a little more protected since its own cover is exactly the same size as the pages. With thick seams pushing underneath the thin pages, I had to add a clear writing board to make it easier to write on the first and last pages of the notebook.

   

   When I fill this up⁴⁴ After 2 months I've used about a third of it., I'm excited to try two other options, in this order:

   • Pith Supply Yuzu⁵⁵ Unfortunately this isn't readily available in the US.: Steven Schultz on YouTube claims this is the perfect lay-flat notebook and the colors look really nice.

   • Midori MD Notebook: It has these little perforated tabs in the corners to mark your location in the book without a fabric bookmark.

3. Updates for March 2026

   31 March 2026

   Here's what I've been working on and thinking about this month.

   • I renamed the "now" series to just "updates," to catalogue what's happened each month.

   • Index pages (lists of articles) contain full article content inline instead of just the title and a link to the article page.

   • I added a human.json with a single entry for my old college friend.

   • The 2025 Priority Gemini bicycle's shift cable disconnected and I had to commute home in a pretty low gear.

   • I swapped out wallets in my Everyday carry.

   I read a few fiction books at the beginning of March after getting all the way through The Lord of the Rings for the first (and probably last) time:

   • Nine Goblins: A Tale of Low Fantasy and High Mischief by T. Kingfisher

   • Witches of Lychford by Paul Cornell

   • Gideon the Ninth by Tamsyn Muir

   And read some articles but unlike books, I don't diligently track all of them:

   • Buc-ee's Is Better at Placemaking Than Your City by Max Mautner

     This piece was uncomfortable but in the best way. The urbanist movement needs more humility and meeting people where they are.

   • Good trains by Robin Sloan

     Not much to takeaway from this one but I love Robin's writing and enthusiasm.

   • GitButler CLI Is Really Good by Mat Duggan

     I'm all in on Jujutsu these days but only started looking around because I detested Git's default one-line graph log ASCII art¹¹ Taste in command line tools matters a lot to me, I guess?. This looks so good that I probably wouldn't have made the switch if this was available at the time.

   • The Most Dangerous Line: Behind the Hawker stall test crashes by Admiral Cloudberg

     A haunting article mixed in with detailed descriptions organizational, engineering, and human failings.

   We started the month recovering from a debilitating cold. When we were on the other side of it, we took our daughter to the beach²² Where she fell over whenever the waves lapped against her legs.. As the heat wave descended, I set up a water table and sand table for her to play with in the backyard.

   The garden had lost some plants over the winter, so we went to our local nursery and picked up a few flowers, shrubs, vegetables, and herbs to get things back on track. I'm pretty excited about the little vertical herb garden we're starting, currently with multiple varieties of thyme, sage, and chives.

   We capped off the month with a road trip up to Sacramento to stay in Folsom and visit with family.

4. Single letter commands

   4 December 2025

   If I use a shell command often, I'll condense into a short, single letter alias as a mnemonic. I've settled on a few key aliases:

   • l: ls, list the contents of a directory

   • e: whatever terminal editor I've latched onto

   • f: fg, bring the last backgrounded job to the foreground

   • j: the Jujutsu version control system

   • c: switch the current directory to a source repository via fzf

   These act like a command layer for the shell, similar to keyboard shorcuts for apps or the terse commands of vi. They're mapped as abbreviations, usually, which expand to their full command when invoked. When I communicate using my terminal scrollback history, any well-known commands involved are visible.

   I've also recently started naming my personal scripts with single letters:

   • h: start a new journal entry with the current date and hour populated

   • n: start an editor in my notes directory

   • d [<title>]: with an argument, create a new draft, or without, start an editor on the drafts directory

   To me, this feels faster and more precise than typing out a longer name.