Function iter_next

src/PyIterableProxyHandler.cc:25–57

static bool iter_next(JSContext *cx, JS::CallArgs args, PyObject *it) {
  JS::RootedObject result(cx, JS_NewPlainObject(cx));

  PyObject *(*iternext)(PyObject *) = *Py_TYPE(it)->tp_iternext;

  PyObject *item = iternext(it);

  if (item == NULL) {
    if (PyErr_Occurred()) {
      if (PyErr_ExceptionMatches(PyExc_StopIteration) ||
          PyErr_ExceptionMatches(PyExc_SystemError)) {      // TODO this handles a result like   SystemError: Objects/dictobject.c:1778: bad argument to internal function. Why are we getting that?
        PyErr_Clear();
      }
      else {
        return false;
      }
    }

    JS::RootedValue done(cx, JS::BooleanValue(true));
    if (!JS_SetProperty(cx, result, "done", done)) return false;
    args.rval().setObject(*result);
    return result;
  }

  JS::RootedValue done(cx, JS::BooleanValue(false));
  if (!JS_SetProperty(cx, result, "done", done)) return false;

  JS::RootedValue value(cx, jsTypeFactory(cx, item));
  if (!JS_SetProperty(cx, result, "value", value)) return false;

  args.rval().setObject(*result);
  return true;
}

static bool iterable_next(JSContext *cx, unsigned argc, JS::Value *vp) {
  JS::CallArgs args = JS::CallArgsFromVp(argc, vp);