This... yq eats yaml. And this is all I need to know (really). I don't know yaml. I don't WANT to know yaml.

Two letter command which I can remember, in the same way that I know jq. And, as a short-form jo. I would not use jo to eat json. I do think that yq is "misnamed" slightly, in that there is no yo command.

(note that I do have yq installed, but not nushell or PowerShell).

shell is glue, not oop -- json is an object notation, converted to stringyness. Which makes for oop->shell. Since "objects" are programmer-think, this should not be the primary command interface. People (not programmers) recognize this, and thus PowerShell is not used by "non-programmers". Ok, you want something above bash (sh, shell), for more programming structure? This is why the #! construct is exec() is so important. That lets you use... um awk, sh, (and should support PowerShell -- not sure). Even C (with tiny-c). I would go with javascript, myself, because it fits with json, and thus jq and jo in the eco-system.

Now, for a criticism of yq -- jq is 30K for a front-end and 350K (or so) for a library. jo is 120K, yq is (gulp) 12MB. Ok, I have the disk space. And it is GO, so ok. Compared with the other GO programs I use commonly: minio (100MB), mcli (mc, 20MB), doctl (20MB), it isn't bad at all. But, I guess that is what GO demands...

Can I teach "functional shell"? Frankly, no. I can get through simple shell in a semester.