I wrote a similar tool to this many years ago that used JATS as an internal document model, using contentEditable, and I can relate to the pain you refer to. Getting the semantics right in cases where you split or join text that has varying types of nested context was hard.

I like what you did here in terms of the cursor that points one way or the other: it tells you if you're in "normal" mode, or for example, in a bold region. I don't think I've seen that before so, if you made it up, that itself is a cool invention.

That's a really nice invention. In general I much enjoy the editor, it's refreshing how it operates, it has many good ideas. But it's not working as it should? How to delete the bold markup, for example? Can't get it done without using the Ctrl+B shortcut, whereas I could create it by typing markdown. When I delete the first bullet, undo doesn't restore it. When i delete the second, undo jumped the cursor to the first bullet.. So there's work to be done still. When copying the text, I'd like to get the markdown text, not some sterilized version of it (leave that to Shift+Ctrl+V if it's needed).

Your LLM can replace your cargo build with bazel in a few sessions. Queue the bazel-haters on HN...

The rust support has gotten really good, and the maintainer for the rust rules works at OpenAI, which, incidentally, is how at least parts of OpenAI builds rust and wasm: https://github.com/openai/codex/blob/main/MODULE.bazel.

I have a pretty complex rust backend in my project. I rent a capable bare-metal build server that costs about $150/mo that powers all my personal CI. All it does is start a systemd service for gh actions self-hosted runner. I can build and release this project in around 2-4 minutes, where before even a local dev iteration cycle would be up to around 10 minutes, much less building and releasing the whole thing, which was around an hour.