Comment by chubot

1 day ago

Oh cool, I'd be interested to read about the issues you had expressing Rust syntax in Vim!

And yes, there are a whole bunch of limitations:

- C function definitions - harder than JavaScript because there's no "function". It's still syntactic, but probably requires parsing, not just lexing.

- C variable definitions - I'd call this "coarse semantic analysis", not coarse parsing! Because of the "lexer hack"

- Indentation as you mention - there was a thread where someone was complaining that treesitter had 2 composed parsers for Markdown -- block and inline -- although I'm not sure if this causes a problem in practice? (feedback appreciated)

---

But I did intend for YSH to be easier to parse than shell, and that actually worked, because it fits quite well in Vim!

I noted here that OSH/bash has 10 lexer modes -- I just looked and it's up to ~16 now

https://www.oilshell.org/blog/2019/02/07.html#2019-updates

Whereas YSH has 3 mutually recursive modes, and maybe 6 modes total.

---

On the "coarse semantic analysis", another motivation is that I found Github's semantic source browser a bit underwhelming. Not sure if others had that same experience. I think it can't really be accurate because it doesn't have a lot of build time info. So I think they could have embraced "coarseness" more, to make it faster

Although maybe I am confusing the UI speed with the analysis speed. (One reason that this was originally a Codeberg link is that Codeberg/Forejo's UI is faster, without all the nav stuff)

There are some related links here, like How To Build Static Analyzers in Orders of Magnitude Less Code: