Function tsn_generator_next

tsn/src/tsn/tsn.cpp:1908–1943

}

static JSValue tsn_generator_next(
    JSContext* ctx, JSValueConst this_val, int argc, JSValueConst* argv, int magic, JSValue* func_data) {
    auto* closure = tsn_get_closure_from_func(func_data[0]);

    if (closure->resume_point >= 0) { // generating
        switch (static_cast<tsn_generator_op>(magic)) {
            case tsn_generator_op::gen_throw:
                // throw the error in the current js context and fallthrough
                tsn_throw(ctx, argv[0]);
                [[fallthrough]];
            case tsn_generator_op::gen_next: {
                auto res = call_closure_callable(ctx, func_data[0], this_val, argc, argv, closure);
                if (JS_IsException(res) != 0) {
                    return res;
                }
                auto iterator_result = tsn_iterator_result(ctx, closure->resume_point < 0, res);
                tsn_release_inline(ctx, res);
                return iterator_result;
            }
            case tsn_generator_op::gen_return:
                closure->resume_point = -1;
                return tsn_iterator_result(ctx, true, argv[0]);
        }
    } else { // completed
        switch (static_cast<tsn_generator_op>(magic)) {
            case tsn_generator_op::gen_next:
                return tsn_iterator_result(ctx, true, JS_UNDEFINED);
            case tsn_generator_op::gen_return:
                return tsn_iterator_result(ctx, true, argv[0]);
            case tsn_generator_op::gen_throw:
                tsn_throw(ctx, JS_DupValue(ctx, argv[0]));
        }
    }
    // should never get here
    return JS_UNDEFINED;
}

tsn_value tsn_new_generator(tsn_vm* ctx, tsn_value closure) {
    auto gen = JS_NewObject(ctx);