Ian Wagner

huh... anything "interesting" with your network like using a VPN? I tried it just now on my Korean home WiFi and on cell data without issue.

hmm… the server is GitHub Pages 😅 Maybe they had an outage?

History repeats.

New on the blog: const assertions.

ianwwagner.com/const-assert...

Elecom Deft Pro - First Impressions I recently picked up a new trackball to replace my prematurely aging Elecom HUGE. Here are my first ...

New trackball arrived today. I wrote a bit about it here: ianwwagner.com/elecom-deft-...

New on the blog: ianwwagner.com/finishing-dr...

Dude, Four Tet is SO GOOD!

AI Tools for API Companies: AI Needs Context, or How Our Auto-Generation Failed Spectacularly Why our obvious approach to building MCP servers failed spectacularly, and what we learned about AI-native API consumption. This is the first post in our series about AI tools for API companies.

🪄 Good AI tooling, especially for APIs, isn't automatic or intuitive. 🪄

In fact, our first attempts failed spectacularly. Read the first post in a new series we're writing about how to build great AI tools (including #MCP servers) for #API companies. 👇

stadiamaps.com/news/ai-tool...

(Or, a more cynical version: "portable" = "it can be ported"... see, we saved you the hand assembly work, so you CAN port it to this other computer :P)

Right?! I've ranted about this several times in the past (offline) and am pretty sure that when C programmers say "portable" they mean "does not require me to hand-write assembly." That's it.

Your C program is almost never *actually* portable for any natural usage of the word.

Super proud of this :) It’s been quite a journey the past few months building this. Expect a few more deep dive blogs soon! (And in case you missed it, I wrote about the quirks of Unicode normalization here: ianwwagner.com/til/unicode-...)

Howdy all. I'm unfortunately not going to be with my employer for much longer due to team relocation. If anyone has any info on roles that would allow me to continue my Rust compiler work (in New York City), they'd be greatly appreciated.

The OG DDD 😍

Seoul Rust Meetup, Wed, Jul 2, 2025, 7:00 PM | Meetup # Welcome to our Meetup! Seoul Rust is a monthly meetup for Rust developers and enthusiasts. Whether you're just learning Rust or are an experienced developer, we hope you

In Seoul? You should come to our meetup next month ;)

Wednesday Jul 2 at 7pm. RSVP: www.meetup.com/rust-seoul-m...

#rust #rustlang

Ownership Benefits Beyond Memory Safety Rust’s ownership system is well-known for the ways it enforcesmemory safety guaranteees. For example, you can’t use some value after it’s been freed. Further, it also ensures that mutability is explic...

Weekend light blog: Ownership benefits beyond memory safety. Or, how the way you implement APIs in can prevent footguns. Inspired by an old friend's post in a Slack chat about hours wasted on this entirely preventable problem!

ianwwagner.com/blog/ownersh...

#rust #rustlang

A railroad diagram in the style of the original JSON spec showing valid tokens, sequence, and repetition rules.

Rust has some pretty baller tooling crates 😀 Generated this railroad syntax diagram for a mustache derived template DSL using github.com/nu11ptr/pest... in just a few seconds 🤯

#rustlang

Building a fitness app? Or planning a hill climb? We can help :)

A list of search results showing the same restaurant twice. The first result has a different appearance, being comprised of mathematical unicode symbols.

Today's fun with Unicode, OpenStreetMap, Foursquare OS Places, and giving users useful search results :)

ianwwagner.com/til/unicode-...

#unicode #programming #openstreetmap

Welcome Most people know me as a programmer. I’ve been developing mobile apps since the month the App Store launched. I love startups, and have co-founded a few.

I wrote a few posts in 2025, AND I have RSS ;) ianwwagner.com

What's your blog? Didn't see a link in the post / your bio ;)

heh... says the president of the country with one of the world's highest incarceration rates.

EDNS Client-Subnet and Geographic DNS DNS is a complex beast, so it’s little surprise when I learn something new. Today I learned a bit more about the internals of how DNS works at various privacy-centric providers.

It's been 0 days since it was DNS 😂 I learned a few things today, and you can too!

ianwwagner.com/til/edns-cli...

Thanks! Not really sure I have any grand plans for it at the moment... just felt like something that needed to exist since MapKit is currently a bit broken 😅 If you're interested in other mappy things though, check out github.com/stadiamaps/f..., which occupies much of my free time these days!

Crate in question: docs.rs/tempfile/lat....

Seems like this is appropriate if your use case is served by temp files. Or does it need to be something in memory for performance reasons (more like a message queue or some other form of IPC)?

Interesting. I mean, it sounds like it's a pretty easy mistake to make, and both of these look like fairly small projects so they probably just work for the author's intended use.

Now I'm curious what you're building though which needs a virtual filesystem. Would something like tempfile work?

Yeah, that's what it looks like. And it also appears the readable file just clones the last bytes that were "committed." Agree it's a weird design choice too. I get the vibe that it's an intentionally minimalist project for unit tests and such, so that probably just never came up as a use case.

It looks like there's a custom drop impl: github.com/manuel-woelk....

I'm a bit too lazy to trace all the threads in a browser, but the reader probably doesn't see anything until the writer is dropped. And flush doesn't really behave like you'd expect.

That doesn't necessarily mean it was designed to support reads from another handle while the file is still "open" (the "trick" is that the block drops the handle). Vfs looks like a minimalist "filesystem" designed for use in unit tests, so I wouldn't expect it to mimic all "usual" behaviors.

I'm not familiar with the vfs crate (and it's sadly not in the rust playground), but I assume what's happening is that the data is not written to the "file" until you flush, some buffer fills up, etc. Most languages do this, and it's often device dependent (ex: a TTY may be line buffered).

I'm definitely doing some crimes with my proc macro implementation, but it's pretty hard to argue with ~200 LOC to replace 456 unit tests and generate a proper data model from a few hundred YAML files at compile time 😂

#rust #rustlang

Oh man, that's a throwback :D