Notices by Chris Fallin (cfallin@mastodon.world)

I don't talk about "mundane dayjob stuff" here as much as I do the spicier compiler tidbits and daydreamy stuff, but: I just finished a several-month odyssey building an implementation of Wasm exception handling for Wasmtime (https://github.com/bytecodealliance/wasmtime/pull/11326), involving IR design and careful tweaks to Cranelift to support the new control flow and metadata outputs, full GC'd exception objects, an unwinder, and the Wasm opcode level semantics. This was very fun! I hope to write a blog post about it soon...

I still need to add it to our fuzzer (we mandate new features to bake for a while with fuzzing before going on-by-default), but assuming nothing catastrophic causes a backout, it should be in Wasmtime 37 released next month.

Then today, someone showed up on our Zulip chat and found it worked great to support setjmp/longjmp in Lua (remember this @tekknolagi ??). With this, and with Nick's excellent work having built out GC, we now have a pretty good platform for higher-level language features!

Excited to hear that our paper on weval, the Wasm partial evaluator, was conditionally accepted to PLDI!

I wrote about weval in a blog-post series (https://cfallin.org/blog/2024/08/28/weval/). It's a way to turn interpreters into compilers "for free".

After I gave a talk at NEU last year, @tekknolagi was interested enough to do some impromptu hacking with me, evaluate the tool on some other interpreters, and we wrote up a paper together.

Our preprint from November is here (https://arxiv.org/abs/2411.10559); more later!

there comes a time in every two-week mid-summer PTO when one has finished one's books, one picks up one's laptop, and has the irresistible urge to build a toy programming language implementation. Fortunately I now recognize the symptoms and am on the mend after only writing half the tokenizer