switch rval := result.(type) {
	case string:
		return FromString(rval), nil
	case float64:
		return FromFloat(rval), nil
	case int64:
		return FromInt(rval), nil
	case uint64:
		if rval <= math.MaxInt64 {
			return FromInt(int64(rval)), nil
		}
		return FromFloat(float64(rval)), nil
	case bool:
		return FromBool(rval), nil
	case jstream.KVS:
		bs, err := json.Marshal(result)