I had a little non-recursive JSON parser hanging around. When you have "nested" levels you've really only got two choices: object, or array. That implies that to track nesting, you just need an array of 1b values. In order to shave the yak properly, I built "nesting compressor" that detected runs of array/object and represented them using a 64b RLE; or, it bailed out, and then just used on-the-fly compression with zstd.

Obviously, any sort of JSON file that fit on a disk I can afford can be parsed into memory in a tiny fraction of its on-disk representation. I modified `yes` to just stream `[` out; the JSON parser handled it just fine — it takes a while to roll a 64b counter.