How to wrap a linked list c struct, struct with pointer to another instance of itself

[jeffective]

Hello, I am a beginner, could someone point me to relevant documentation or provide some insight on how to wrap this linked list c struct and function?

typedef struct ec_adapter ec_adaptert;
struct ec_adapter
{
   char   name[EC_MAXLEN_ADAPTERNAME];
   char   desc[EC_MAXLEN_ADAPTERNAME];
   ec_adaptert *next;
};
ec_adaptert * ec_find_adapters(void);

ChatGPT suggests something like this:

nb::class_<ec_adaptert>(m, "ec_adapter")
        .def_rw("name", &ec_adaptert::name)
        .def_rw("desc", &ec_adaptert::desc)
        .def_rw("next", &ec_adaptert::next);

  m.def("ec_find_adapters", []() {
      return nb::borrow<nb::list>(Py_BuildValue("N", ec_find_adapters()));
  });

but that fails to compile.

I'm thinking this function should perhaps return a list but definitely open to suggestions.

[jeffective]

I figured out one way to do it.

m.def("ec_find_adapters", []() {
        ec_adaptert *adapters = ec_find_adapters();
        nb::list adapter_list;
        while (adapters != nullptr) {
            nb::dict adapter_dict;
            adapter_dict["name"] = nb::bytes(adapters->name);
            adapter_dict["desc"] = nb::bytes(adapters->desc);
            adapter_list.append(adapter_dict);
            adapters = adapters->next;
        }

        return adapter_list;
    });

[jeffective]

I figured out an even better way

nb::class_<ec_adaptert>(m, "ec_adaptert")
        .def_prop_ro("name", [](ec_adaptert *adp) -> nb::bytes { return nb::bytes(adp->name); })
        .def_prop_ro("desc", [](ec_adaptert *adp) -> nb::bytes { return nb::bytes(adp->desc); });

    m.def("ec_find_adapters", []() -> nb::typed<nb::list, ec_adaptert> {
        ec_adaptert *adapters = ec_find_adapters();
        nb::typed<nb::list, ec_adaptert> adapter_list;
        while (adapters != nullptr) {
            adapter_list.append(adapters);
            adapters = adapters->next;
        }
        return adapter_list;
    });

which gives me the full stub from the stub generator

class ec_adaptert:
    @property
    def name(self) -> bytes: ...

    @property
    def desc(self) -> bytes: ...

def ec_find_adapters() -> list[ec_adaptert]: ...