Absolutely not. Fish may be written in more of a cross-platform language/ecosystem now but as a unix shell, we make heavy use of unixisms that have no windows equivalent throughout its architecture, design, and implementation.

Is it theoretically, someday possible? Sure. Does rust bring us closer? Maybe a tiny bit, but honestly not much (it has a more elegant per-platform targeting/conditional compilation model but it’s nothing that wasn’t possible in C/C++, and we don’t use the “native” oob cross-platform std lib stuff like launching procs).

WSL is a priority target though.

Bash has been ported to windows probably more than once. There are a few clunky corners but it works well enough.

Not gonna say it’s easy but may be less difficult than it appears to some.

Looks like rust is reasonably well working with cygwin/msys2 based on some github issues, https://github.com/rust-lang/rust/issues/79854 . Given that, I'd expect that this rust rewrite should work under them at least. Though it's obviously not a fully native build since you've got a bunch of compatibility layers involved to bring in those mentioned unixisms.

If you’re after a UNIX shell that runs on Windows without WSL / mingw then there are a few options such as Murex and Elvish.

However personally I’d still recommend WSL if just for the coreutils userland.

Disclaimer: I’m the author of Murex shell

clever name choice, unfortunately, it makes search for it almost imposible, because "murex shell" finds only pages about marine life

would you share a link please?

Search for “murex Unix shell”.

Top hit for me is https://pkg.go.dev/github.com/lmorg/murex

Use Nushell instead. It's also written in Rust: https://www.nushell.sh/

A Windows build is explicitly not in the plans, at least today, from what I've seen.

Yeah even if it built, a windows shell needs to do different things. I’ve had some success running it in msys2 though: https://evil.link/2022/03/31/using-fish-shell-on-windows/

Ironically the RIIR project makes this more difficult; we lost support for Cygwin altogether and I think the msys2 stuff would need to be re-explored if it even remains possible.