It might be possible to design a good Unix shell based on objects, with the ability to "call back into" programs. But I haven't seen one yet that I'd prefer over Ruby or Python.
I do think objects make plenty of sense in languages like AppleScript, which essentially allowed users to script running GUI applications. And similarly, Powershell's objects might be right for Windows.
But nushell shows how far you can push "dumb" structured data. And it still feels "Unix-like", or at least "alternate universe Unix-like."
The other reason I'm suspicious of objects in shells is that shell pilelines are technically async coroutines operating over streams! That's already much further into the world of Haskell or async Rust than many people realize. And so allowing "downstream" portions of a pipeline to call back into "upstream" running programs and to randomly change things introduces all kinds of potential async bugs.
If you're going to have a async coroutines operating on streams, then having immutable data is often a good choice. Traditional Unix shells do exactly this. Nushell does it, too, but it replaces plain text with structured data.
I do think objects make plenty of sense in languages like AppleScript, which essentially allowed users to script running GUI applications. And similarly, Powershell's objects might be right for Windows.
But nushell shows how far you can push "dumb" structured data. And it still feels "Unix-like", or at least "alternate universe Unix-like."
The other reason I'm suspicious of objects in shells is that shell pilelines are technically async coroutines operating over streams! That's already much further into the world of Haskell or async Rust than many people realize. And so allowing "downstream" portions of a pipeline to call back into "upstream" running programs and to randomly change things introduces all kinds of potential async bugs.
If you're going to have a async coroutines operating on streams, then having immutable data is often a good choice. Traditional Unix shells do exactly this. Nushell does it, too, but it replaces plain text with structured data.