I prefer a SQL-like format. It’s not as complete but it cover most of the day-to-day use cases. Take a look at https://github.com/dcmoura/spyql (I am the author). Congrats on fq!
Thanks! i actually experimented a bit with an SQL-like interface for while, dump things into sqlite and use that as query engine. Problem usually was that file formats tend to be mix of array and tree structures more then relational and at least standard SQL is not great for that. Maybe some graph-SQL dialect could work?