Are there any domains in which fish clearly outperforms nu? I've been thinking for a while that I should experiment more with Fancy Modern Shells, and your shell-chat is inspiring me to move more actively in that direction, but I'm not sure whether to interpret your delight with nu as "this is tradeoff-y but better-on-net for my use cases relative to fish" or as "this seems (at least for now) like a straightforward upgrade".
(context: I'm unimpressed by zsh)
I would say nu is tradeoffy. fish is definitely way more conservative with its improvements, which means that if you're used to shell you will learn fish faster than you will learn nu.
fish has also spent a lot more time being polished. Anything you'd want to do in shell is possible in fish.
On the other hand, nu is still in active development and missing some features, like, you can't forward flags:
Apparently a related issue was fixed four days ago!
To be fair, you can still forward flags on regular shell scripts, just not in nu commands. It's really just the new stuff that's kinda rough, but you still do have access to all the Unix stuff.
So yeah, probably relatedly, it's being updated frequently enough that the docs are sometimes out-of-date.
So probably the main flaw of nu is that copy/pasting shell commands from the internet is way more likely to break than it is in fish.
Going back to fish, fish has a lot of features built around making it easier to work with normal shell stuff. Stuff like autofilling completions from parsing man pages. For instance, if I type "git" and press Tab:
And if I press Space and then Tab:
And if I go all the way to "git add -"
I don't know of any other shell that does anything this cool (nu doesn't, zsh can be configured to do the last one but not the others afaik).
I would say this is how I would compare them. Nu is a cool programming environment, and it's about this flashy about its own features, but fish is definitely flashier about helping you use regular commandline tools.
Personally, while I like the little things in fish, I do feel like they're not quite as valuable to me as Nu's extremely flashy new features about manipulating structured data, being a language that doesn't suck, and all that.
