>Years ago, a project idea I was really interested for a while was to try to write a shell in Rust that works more like PowerShell.

So this whole conversation and a different one about python and it's behavior around `exit` vs `exit()` sent me down a rabbit hole of seeing if I could make the python interpreter have a "shell like" dsl for piping around data. It turns out you sort of can. I don't think you can defeat the REPL and make a function call like `echo "foo" "bar" "baz", but you can make it do this:

  netstat("-ln") | filter_by({"state":"ESTABLISHED"}) \
    | group_by(["local_port"]) | count_groups \
    | sort("count", descending=True) | limit(10)

And only ever parse plain text once on the input from netstat. For your amusement/horror I present "ShPy": https://gitlab.com/tpmoney/shpy

>Years ago, a project idea I was really interested for a while was to try to write a shell in Rust that works more like PowerShell. >Where I got stuck was the fundamentals: PowerShell heavily leans on the managed virtual machine and the shared memory space and typed objects that enables.

Hmmm, if you need that sort of shared memory access throughout the shell, you probably need a language like python (or maybe better Lisp) with a REPL and the ability/intent to self modify while running. Of course, every time you have to farm out because you don't have a re-written replacement internally to the shell app, you'd still parsing strings, but at least you could write a huge part of data processing in the shell language and keep it in house. Years ago I worked for a company that was using Microsoft's TFVC services (before it was azure devops or whatever they call it now) and wrote a frontend to their REST API in python that we could call from various other scripts and not be parsing JSON everywhere. Where this is relevant to the discussion is that one of the things I built in (in part to help with debugging when things went sideways) was an ability to drop into the python REPL mid-program run to poke around at objects and modify them or the various REST calls at will. With well defined functions and well defined objects , the interactive mode was effectively a shell for TFVC and the things we were using.

Though all of that said, even if one did that, they would still either need to solve the "object model" problem for disparate linux tools, or worse commit to writing (or convincing other people to write and maintain) versions of all sorts of various tools in the chosen language to replace the ones the shell isn't farming out to anymore. Its one thing to chose to write a shell, it's something else entirely to choose to re-write the gnu userland tools (and add tools too)

> Years ago, a project idea I was really interested for a while was to try to write a shell in Rust that works more like PowerShell.

Today's your lucky day!

https://www.nushell.sh