a := v.Any()
		_, jm := a.(json.Marshaler)
		if err, ok := a.(error); ok && !jm {
			s.appendString(err.Error())
		} else {
			return appendJSONMarshal(s.buf, a)
		}
	default:
		panic(fmt.Sprintf("bad kind: %s", v.Kind()))
	}
	return nil
}

func appendJSONMarshal(buf *buffer.Buffer, v any) error {
	// Use a json.Encoder to avoid escaping HTML.
	var bb bytes.Buffer
	enc := json.NewEncoder(&bb)