How to provide custom error instead of "missing delimiter"

[Xottab-DUTY]

So, instead of saying "missing delimiter" for everything that uses dsl::delimited I want to provide more descriptive errors... Didn't found a way to do that yet..
Can someone help me?)

// Look at struct c_style

struct comment : lexy::token_production
{
    struct c_style : lexy::transparent_production
    {
        struct unterminated_error
        {
            static constexpr auto name = "unterminated comment";
        };
        static constexpr auto rule = []
        {
            auto delim = dsl::delimited(LEXY_LIT("/*"), LEXY_LIT("*/"));
            return dsl::must(delim(dsl::code_point)).error<unterminated_error>; // compiles, but doesn't help, the error in the output is still "missing delimiter"
            //return delim(dsl::code_point) | dsl::error<unterminated_error>; // doesn't compile
        }();
    };

    struct cpp_style : lexy::transparent_production
    {
        static constexpr auto rule = []
        {
            // A comment begins with a // and ends at newline or EOF.
            auto comment = dsl::delimited(LEXY_LIT("//"), dsl::eol);
            // We can use a backslash to escape the next character (or EOF).
            auto escape = dsl::backslash_escape.rule(dsl::eof / dsl::code_point);

            // A comment consists of code points.
            return comment(dsl::code_point, escape);
        }();
    };

    static constexpr auto rule = dsl::p<c_style> | dsl::p<cpp_style>;
    static constexpr auto value = lexy::as_string<std::string>;
};

[Xottab-DUTY]

This works almost ideally:

static constexpr auto rule = []
{
    auto delim = dsl::delimited(LEXY_LIT("/*"), LEXY_LIT("*/"));
    return dsl::try_(delim(dsl::code_point), dsl::error<unterminated_error>);
}();

Except that "missing delimiter" error is still there.

[foonathan]

dsl::must doesn't work, as it triggers the error when you don't have an initial /* (it only checks that the branch condition is there).

There is currently no way to override the error. I will add one in the next couple of days.

[foonathan]

I have now implemented it. You can use delim.limit<unterminated_error>()(...) to override lexy::missing_delimiter (and optionally specify an additional condition to detect it besides EOF).