[Question] How to get line/column information in a semantic action? about cpp-peglib HOT 2 CLOSED

@maychan111, sorry for the late reply. I just found this message...

enable_ast() method in peglib.h may do the similar that you want to do.

    template <typename T = Ast>
    parser& enable_ast() {
        for (auto& x: *grammar_) {
            const auto& name = x.first;
            auto& rule = x.second;

            if (!rule.action) {
                auto is_token = rule.is_token;
                rule.action = [=](const SemanticValues& sv) {
                    auto line = line_info(sv.ss, sv.c_str()); // <- Translate the current text position into line and columns numbers.

SemanticValue structure has ss member which is the start pointer of the input source. sv.c_str() gives us the start pointer to the matched string for the rule. line_info call with those pointers will find line and column numbers for the position. (As you see in the code, line_info uses a naive linear algorithm. So I recommend to call this function only when it's necessary. )

Is this information enough for you to solve your problem? (If so, I'll update the README regarding this issue.)

Thanks for the report!

from cpp-peglib.

Great suggestion. It totally works! Thank you very much. Great library.

from cpp-peglib.