"superset" is just marketing mumbo jumbo that says: "I promise to embed an x86 virtual machine inside my spec that'll still parse whatever weird JSON you're currently handling and give it back to you as an object in your programming language"
$ echo '{ "Hello": "World" }' | tson --parse
ERROR: ...refusing to interoperate w/ JSON b/c we want to be different
...that's a non-starter. If they're trying to replace or supplement JSON (same way `uv` has been replacing / supplementing `pip`, and `deno` is doing the same with `node`), you've got to do the work of supporting the extant real-world use cases that are floating around but with a healthy layer of $BETTER sprinkled on top.
$ echo '{ "Hello": !number 3.14 }' | jq '.'
jq: parse error: Invalid numeric literal at line 1, column 19
...THAT's the difference/extension.
I've been explicitly trying to support `--json5` on some of my internal work tooling. Being very explicit that I'm not parsing `--json`, but instead using a slower (but more forgiving) `--json5` which would allow comments, trailing commas, whatever JSON5 claims to support.
This `--tson` feels like it's solving two problems in disguise:
1) It wants to be `--json6` (eg: `pi: !number 3.14`)
2) It wants to use it's own `--json6` (aka: `--tson`) to write "json-ish schemas" (eg: `foo: [text; 1..10]` for presumably a list of maximum of 10 elements?)
...JSON was a blessing because it existed naturally as an unambiguous "lists, dicts, values" representation that most programming languages treat as first-class citizens. Missing "sets" and things like "date" or "boolean" are certainly under-specified, but that's the real-world impact of JSON as lowest common denominator.
SCHEMA's don't have nearly as much natural, unambiguous representations across many programming languages. The closest thing I can think of is straight up Java + Constructors (ie: a full programming language for object initialization but w/o allowing interaction or behavior).
CalendarEvent x = new CalendarEvent( Date start, Date end, Boolean all_day, List<Invitee<...>>, ...etc... )
...where my mind has gone lately is doubling down on TypeScript's `*.d.ts` as a "naturally occurring, expressive schema language". It's hella-more-complicated to parse/validate than JSON, but there's tons of tooling around it, and it's relatively unambiguous that it can solve and express Real World(tm) engineering problems.