-- json fidelity (iteration 5 strictness): a Bool field encodes true/false
-- (WOB_FIELD_BOOL / WOB_FIELD_NIL_BOOL in field_class — the kind byte alone
-- cannot tell Bool from Int), a ?Bool nil is null both ways, and a JSON
-- number with a fraction or exponent is MALFORMED for an Int field: the
-- checked decode yields nil instead of silently truncating.
use json

class Flags {
  on: Bool
  maybe: ?Bool
  n: Int
}

fn main() -> Int {
  print(json.encode(Flags { on: true, maybe: nil, n: 7 }));
  let back = json.decode("{\"on\":false,\"maybe\":true,\"n\":9}") as Flags;
  if back != nil {
    print(json.encode(Flags { on: back.on, maybe: back.maybe, n: back.n }));
  }
  let frac = json.decode("{\"on\":true,\"maybe\":null,\"n\":3.7}") as Flags;
  if frac == nil { print("fraction rejected"); }
  let expo = json.decode("{\"on\":true,\"maybe\":null,\"n\":2e3}") as Flags;
  if expo == nil { print("exponent rejected"); }
  return 0;
}