TC39 General on 2026-03-26

16:00	<Michael Ficarra>	https://p.ocmatos.com/blog/jsse-a-javascript-engine-built-by-an-agent.html
16:06	<jschoi>	`Array.fromAsync` was the final fix Ah yes, `Array.fromAsync`, the final frontier…
16:08	<Michael Ficarra>	I'm assuming it's because the plan it created roughly ordered recent things by when they were added to the language
16:11	<jschoi>	Its PLAN.md was apparently generated “from the ECMAScript spec and test262 submodules”, so I wonder how that ordering happened. Not that it matters much.
16:51	<bakkot>	I wonder if it has garbage collection
16:51	<bakkot>	if I were given the task to implement a spec-compliant JS engine with no further qualifications I definitely would not add garbage collection
16:58	<jschoi>	Claude picked a reasonable feature order, but it made some architectural decisions early on (like how to handle generators, how to structure the GC, how to deal with WTF-8 strings) that caused expensive rework later.
17:15	<Ashley Claymore>	was the answer for how to structure the GC: "use a noop"
17:21	<Jesse>	https://github.com/pmatos/jsse/blob/main/src/interpreter/gc.rs
17:27	<Ashley Claymore>	I do think this is a great benchmark. As the definition is very fixed. It will be interesting what would happen given the same challenge 1 year from now
17:27	<Ashley Claymore>	1 year is enough time for models to have this repo in their training set
17:28	<Michael Ficarra>	it seems like it attempts GC before every statement: https://github.com/pmatos/jsse/blob/c490bc3fee8c4c8e6b2452f4acacb60d84b02a39/src/interpreter/exec.rs#L112
17:28	<Michael Ficarra>	which seems both too coarse and too fine