How to access parse_state from dsl::scan or lexy::rule_scanner?

[Korsar13]

Discussed in https://github.com/foonathan/lexy/discussions/150

^{Originally posted by Korsar13 June 16, 2023}

struct known_user_type: lexy::scan_production<std::string>
{
    template <typename Reader, typename Context>
    static constexpr scan_result scan( lexy::rule_scanner<Context, Reader>& scanner )
    {
        // scanner.context() -- private method?
    }
};