XS VS aush

Both provide scripting languages that are more "functional" (in the sense of functional programming). nushell is newer, written in Rust, under active development, and seems to be stabilizing. es is older (circa 1990s), written in C, and based on rc and scheme. There's also a C++ version xs that appears abandoned as well as a few forks sprinkled around. None are POSIX-compatible.

I'd rather have a more powerful shell that uses a functional style yet preserves many shell semantics we're all familiar with (like XS, https://github.com/TieDyedDevil/XS , except maintained!) than an easier-to-use shell

I'll put it this way: Nu shell seems perfectly supportive of my philosophy that a shell is basically a REPL for a computer, and they're taking the ergonomics of an interactive REPL along with the programming language that powers that REPL seriously.

The thing is, there's currently NOTHING GOOD for "shell scripting". Shell sucks (yes it does), so for anything more than very short things I'd rather write Python. But Python sucks for shell-like things, parallelization, it has slow startup, and you also can't do things like put environment variables into your session or change the working directory, so you often wind up writing shims (eg. Broot's br alias - https://dystroy.org/broot/install-br/).

Yes I've looked at Xonsh but maybe the additional syntax is offputting to me. Like, I wouldn't use it as a shell over Zsh (how's Xonsh's fzf support? I don't know, but I know everything's going to support Zsh), and I dunno if I want to use its syntax extensions over just Python. Though It's always on my list of things to re-explore, and maybe it'll click one day. But it being based in Python makes it feel slow (I wrote my prompt in Zig to get it to be fast...)

This is relevant to mention: I wrote a small Python library (https://github.com/kbd/aush) that's basically a DSL for subprocesses, so it tries to make it more convenient to do shell-like things. I find it preferable to shell or Python alone most of the time. Here's an example of its use in my script that creates a new Python project: https://github.com/kbd/setup/blob/master/HOME/bin/create-pyt...

I haven't figured out a convenient way to implement shell piping well with Python's pipe operator, or pass through interactive output directly (so things that "update" the display, like poetry and npm don't behave the same as they do interactively) so it's still .9 status, but it works really well for what it is, and you can always write "regular Python" along with it.

Anyway, Nu seems to be an attempt to put a "real" programming language REPL in my shell, from people who have serious language experience, so I'm hopeful it'll be great.