Function isNull

src/function/cast_from_string_functions.cpp:251–269

}

static bool isNull(std::string_view& str) {
    auto start = str.data();
    auto end = start + str.length();
    skipWhitespace(start, end);
    if (start == end) {
        return true;
    }
    if (end - start >= 4 && (*start == 'N' || *start == 'n') &&
        (*(start + 1) == 'U' || *(start + 1) == 'u') &&
        (*(start + 2) == 'L' || *(start + 2) == 'l') &&
        (*(start + 3) == 'L' || *(start + 3) == 'l')) {
        start += 4;
        skipWhitespace(start, end);
        if (start == end) {
            return true;
        }
    }
    return false;
}

// ---------------------- cast String to List Helper ------------------------------ //
struct CountPartOperation {