You tell the agent to write a whimsical tutorial book about the language, it takes about an hour :)

This enables different satisfactions. You can still choose all your options but have a working repl or small compiler where you are trying them within minutes.

Also you decide how much in control you are. Want to provide a hand made grammar? go ahead, want the agent to come up with it just from chatting and pointing it to other languages, ok too. Want to program just the first arithmetic operator yourself and then save the tedium of typing all the others so you can go to the next step? fine...

So you can have a huge toy language in mere days and experiment with stuff you'd have to build for months by hand to be able to play with.

My own 100% hallucinated language experiment is very very weird and still has thousands of lines of generated examples that work fine. When doing complex stuff you could see the agent bounce against the tests here and there, but never produced non-working code in the end. The only examples available were those it had generated itself as it made up the language. It was capable of making things like a JSON parser/encoder, a TODO webapp or a command line kanban tracker for itself in one shot.

Ugh sounds like work, we are vibing here. Or can we also vibe-science? :)

I agree, it´s mostly a silly whim taken too far. Too much time in my hands.

In particular the whole stack based thing looks questionable.

In fact the very first answer by Gemini proposed an APL-like encoding of the primitives for token saving, but when I started the implementation Claude Code pushed back on that, saying it would need to keep some sane semantics around the keywords to be able to understand the programs.

The very strict verification story seems more plausible, tracks with the rest of the comments here.

What has surprised me is that the language works at all, adding todo items to a web app written in a week old language felt a bit eery.