Matt Keenan

A screenshot of FormalZ which looks like a tower defence game, but with extra "pre" and "post" condition panels at the bottom.

I love this idea for a tower defence game where the enemies are bad programs and the towers use pre/post-conditions to filter them out.

github.com/FormalZ/form...

16.02.2026 15:25 — 👍 2    🔁 1    💬 0    📌 0

#SPLASH folks, check out our Distinguished Paper (!) talk this afternoon at 14:15 on "Incremental Bidirectional Typing via Order Maintenance". Thomas will tell you how to efficiently update type information (including error marks) in response to local edit actions. A small step *static* semantics!?

16.10.2025 03:58 — 👍 17    🔁 5    💬 0    📌 0

merged a sizeable PR to hazel dev today including stuff shown here on inline evaluation and playing cards. also: caret animation. you can play with these here: hazel.org/build/dev/; see Probes, Cards, and Projectors slides in docs. PR notes here: github.com/hazelgrove/h...

17.03.2025 01:14 — 👍 31    🔁 7    💬 1    📌 0

I am once more seeking participants for a user study. We'll be evaluating a prototype code editor that completes your text with placeholders for missing tokens expected by the language. Here's a short video of me motivating the editor and study.

Details in thread. Reskeets appreciated! 🙏

14.03.2025 19:26 — 👍 34    🔁 24    💬 2    📌 1

Cyrus Omar receives 1938E Award He has been recognized for innovative teaching, mentorship, and dedication to undergraduate research.

I'm honored to receive the 1938E Award, which honors "outstanding young faculty members who demonstrate excellence in teaching, mentoring, and contributing to the educational growth of the College". Working with budding PL nerds is a highlight of my job!

cse.engin.umich.edu/stories/cyru...

03.03.2025 18:28 — 👍 66    🔁 8    💬 11    📌 0

new tylr featuring inline obligations. press tab to jump to the next obligation, either a hole or a token-completion, or to accept the current completion.

(no language models were harmed in the making of this video)

12.02.2025 20:24 — 👍 24    🔁 6    💬 2    📌 1

Counting Sandwiches This survey is about ground-breaking research into the effects of division and construction of bread on the frequency of sandwiches. If you object to them being called sandwiches (e.g. "These are sol...

Have I ever gotten you to complete my sandwich survey? forms.gle/7HUn6vCb72CF...

15.01.2025 02:43 — 👍 2    🔁 0    💬 1    📌 0

more live value probing. now tracking which values are part of the same closure tree. (the inner function h is called twice inside function g, which is called twice at the top level. so each value inside g but not h has two associated values in h)

11.12.2024 01:46 — 👍 50    🔁 7    💬 2    📌 0

inline probe projector for live value display, now with hover that shows the values of variable references inside a probed expression

07.12.2024 20:49 — 👍 17    🔁 2    💬 0    📌 0

Thanks to @negabinary.bsky.social I will now be referring to rebasing as retconning and mainline commits as canon events.

25.11.2024 00:31 — 👍 10    🔁 2    💬 0    📌 0