Transforming the shell is a great opportunity for a new project, and as you said should probably should be done in Python or JS. Lua is a good option as well for its elegance, though it's a bit less popular than the others.
As for Z.lua, this is an interesting project and I really like seeing modern languages enriching what we do every day on the command line. Very cool!
Why Create a New Unix Shell? http://www.oilshell.org/blog/2018/01/28.html
I took a very long route to doing it though, first implementing OSH (which will run existing shell scripts, which is close to done, but slow) and then Oil (a new language, not implemented).
This is because POSIX shell/bash has a really strong network effect. zsh and fish are better in many respects, but people are locked into bash because that's what "everybody else uses".
It's analogous to how C has a really strong network effect because e.g. every kernel is written in C. So C++ became a popular language in a large part because it's compatible with C. (Though the analogy breaks down because the Oil language isn't a superset of bash, so we can break free of legacy. The project is though.)
In my mind, I think of Oil as a mix between Python and shell, with some elements of Ruby and JS (blocks, function literals, etc.)
And yes, network effects are so important—your C++ example is spot on. One recent example that comes to mind is the adoption from python2 to python3, showing just how big a barrier those network effects are to adopting something incompatible.
It exposed the slowness issue though. I have a plan for that, but it's a bunch of work.
It will help me if people try it and give feedback -- I'll give details in the post.
I definitely agree about Python 2/3. I think you basically can't overestimate the amount of inertia a popular language has. I'm sure there will be patches floating around for Python 2 for a long time after the core team stops maintaining it next year.
Another example is all the compile-to-JS languages. I think TypeScript is the most popular in part because its transition path is the easiest, i.e. it's a superset of JS.
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The number of times I've used a for loop in shell is roughly equal to the number of times I've had to look up how to use a for loop in shell. Relatedly, I generally switch to Ruby when my scripts get complex enough to require control flow.
This is my attempt so solve a small personal pain point in the shell while trying to keep track of various commands: https://github.com/bonidjukic/aka
It definitely comes nothing close to the Z.lua, but the enjoyment generated from getting to write the thing which optimizes even the tiniest parts of your daily tasks is quite wonderful.
help
help if
help function
etc.But I expect for adoption it'll need to be a more widely-used langauge
They could have just used F# as the new shell language, the interpreter already exists, the syntax is clean and concise, etc.
Just a few days ago, I saw a shell interpreter that had a method for bouncing in and out of Python with ease.[3] I'm sure the Javascript version isn't long behind.
[1] https://coffeescript.org/#overview
[2] https://www.npmjs.com/package/shelljs
[3] https://xon.sh/tutorial.html#python-mode-vs-subprocess-mode
But you can! The dot is spelled '|' of course, and 'map' for historical reason is called 'xarg'. There is no real lambda syntax nor closures though, everything is stringly typed.
But it’s fun to use, still. I might come back to it a few versions down the road.
Most shells offer a convenient syntax around a lot of (fantastic) utilities that often mirror C libraries (notably posix). When we were working in C, having our shell mirror parts of that at times while being a very dynamic language at other times sounds great.
But we have a much more varied landscape of language and library options now, and many developers haven’t ever used C or posix.
So my thought is: what if we had a shell that was designed to interop with JS (or python, or ideally a language the user knows well), instead of C/posix. What if, instead of having to remember bash’s for loop syntax (or xargs), you could just write .map() and iterate over lines/execute commands that way?