Jon Gjengset
@jonhoo.eu
Rust live-coder and OSS tinkerer who loves teaching. I try to maintain a high SNR. Wrote Rust for Rustaceans. At Helsing.ai. Formerly AWS. Co-founded ReadySet. @jonhoo elsewhere. he/him/they
Not *too* much actual ANTLR stuff in there unfortunately, but at least I got to shout out your work in a small way :D Issues now filed:
- github.com/antlr4rust/a...
- github.com/antlr4rust/a...
- github.com/antlr4rust/a...
- github.com/antlr4rust/a...
- github.com/antlr4rust/a...
- github.com/antlr4rust/a...
February 8, 2026 at 9:57 PM
Not *too* much actual ANTLR stuff in there unfortunately, but at least I got to shout out your work in a small way :D Issues now filed:
- github.com/antlr4rust/a...
- github.com/antlr4rust/a...
- github.com/antlr4rust/a...
- github.com/antlr4rust/a...
- github.com/antlr4rust/a...
- github.com/antlr4rust/a...
They _are_ automated, so can't guarantee they're all useful, but from a glance and without knowing the internals of the ANTLR4 Rust code, they _seem_ legitimate.
February 8, 2026 at 9:24 PM
They _are_ automated, so can't guarantee they're all useful, but from a glance and without knowing the internals of the ANTLR4 Rust code, they _seem_ legitimate.
And third, I've had the LLM do some benchmarking of avdl, and it's come up with some hotspots in the ANTLR4 Rust code based on the resulting flamegraphs — would you be interested in its reports, or not so much?
February 8, 2026 at 9:24 PM
And third, I've had the LLM do some benchmarking of avdl, and it's come up with some hotspots in the ANTLR4 Rust code based on the resulting flamegraphs — would you be interested in its reports, or not so much?
As for the LLM bit — I think this is an ideal powercoding (LLM + code review) use-case since we a) have access to the existing Java code and b) there's an infinite supply of trusted tests (the same IDL passed to the Java tool should produce the same JSON). But let's see how it goes!
February 2, 2026 at 6:57 PM
As for the LLM bit — I think this is an ideal powercoding (LLM + code review) use-case since we a) have access to the existing Java code and b) there's an infinite supply of trusted tests (the same IDL passed to the Java tool should produce the same JSON). But let's see how it goes!
If you don't know Avro, it's Apache's equivalent to Google's Protocol Buffers. See avro.apache.org/docs/1.12.0/....
IDL Language
Introduction This document defines Avro IDL, a higher-level language for authoring Avro schemata. Before reading this document, you should have familiarity with the concepts of schemata and protocols,...
avro.apache.org
February 2, 2026 at 6:57 PM
If you don't know Avro, it's Apache's equivalent to Google's Protocol Buffers. See avro.apache.org/docs/1.12.0/....
In other timezones: everytimezone.com/s/9a5b6b03
Every Time Zone Converter
Easily find the exact time difference with the visual Time Zone Converter. Find meeting times for your contacts, locations and places around the world. Never warp your brain with time zone math again.
everytimezone.com
December 26, 2025 at 1:00 PM
In other timezones: everytimezone.com/s/9a5b6b03
Oh, forgot the link to see the time in your timezone. YouTube should show it, but otherwise, you can use everytimezone.com/s/70bf2c9d 🕚 [4/3]
Every Time Zone Converter
Easily find the exact time difference with the visual Time Zone Converter. Find meeting times for your contacts, locations and places around the world. Never warp your brain with time zone math again.
everytimezone.com
November 24, 2025 at 9:16 PM
Oh, forgot the link to see the time in your timezone. YouTube should show it, but otherwise, you can use everytimezone.com/s/70bf2c9d 🕚 [4/3]
There are already several Rust implementations (github.com/gunnarmorlin...), this excellent write-up (curiouscoding.nl/posts/1brc/), and even an existing stream (www.youtube.com/watch?v=Q-0d...), but I'm hoping that walking through the process live will still be a good teaching exercise. [3/3]
One Billion Row Challenge
Table of Contents External links The problem Initial solution: 105s First flamegraph Bytes instead of strings: 72s Manual parsing: 61s Inline hash keys: 50s Faster hash function: 41s A new flame graph...
curiouscoding.nl
November 24, 2025 at 9:14 PM
There are already several Rust implementations (github.com/gunnarmorlin...), this excellent write-up (curiouscoding.nl/posts/1brc/), and even an existing stream (www.youtube.com/watch?v=Q-0d...), but I'm hoping that walking through the process live will still be a good teaching exercise. [3/3]
Come join me on Saturday at 11am UTC over on youtube.com/live/g2EKNXK..., and we'll see what we can squeeze out of it 🏎️ [2/3]
One Billion Row Challenge in Rust
YouTube video by Jon Gjengset
youtube.com
November 24, 2025 at 9:14 PM
Come join me on Saturday at 11am UTC over on youtube.com/live/g2EKNXK..., and we'll see what we can squeeze out of it 🏎️ [2/3]
@adamconover.net is here though, and also worth checking out — not as focused on tech and policy, more on fact-finding journalism on everyday topics with a humouristic bent (e.g., "Adam ruins everything").
November 9, 2025 at 8:01 PM
@adamconover.net is here though, and also worth checking out — not as focused on tech and policy, more on fact-finding journalism on everyday topics with a humouristic bent (e.g., "Adam ruins everything").
I don't think Cory is on Bluesky, but his website is pluralistic.net. Highly recommend giving his writings a read (though be warned — he writes a *lot*).
Pluralistic: Daily links from Cory Doctorow – No trackers, no ads. Black type, white background. Privacy policy: we don't collect or retain any data at all ever period.
pluralistic.net
November 9, 2025 at 4:42 PM
I don't think Cory is on Bluesky, but his website is pluralistic.net. Highly recommend giving his writings a read (though be warned — he writes a *lot*).