[fivea]

> Is there something like this for jq?

It's a filter. You can name-drop math stuff and even mention monads and the like, but it's just predicates, maps, a reductions.

Also, I'm not aware of a single person who ever looked at relational algebra beyond the introductory lessons of a relational databases 101 course, and even then that stuff was mostly in the way.

[Zababa]

Your are the one name-dropping three mathematical concepts though? I'm not sure I understand your reasoning here. I'm talking about the basis for jq in general, not just your example. And if your message is representative of how the people that created jq think, I guess the answer is no and jq falls into the "no solid theory behind it" category.

I don't think my message was implying that jq is a worse (or better) tool for it. I was just explaining that for some people, tools with a theory behind are easier to learn and understand than tools without.