//loop until got the largest primnumber with the same class attrib
void performLoop(int class_attrib; int current_prim; int target_class; int result_array[]; int max_value) {
    int new_class_attrib = 0;
    do {
        current_prim += 1;
        push(result_array, current_prim);
        new_class_attrib = prim(0, 'class', current_prim);
    } while (new_class_attrib == target_class);
    max_value = current_prim;
}

int target_class = 0;
int class_attrib = 0;

for (int prim = 0; prim < @numprim; ++prim){
    class_attrib = prim(0, 'class', prim);

    if (class_attrib == target_class) {
        int result_array[] = {};
        int max_value = 0;
        performLoop(class_attrib, prim, target_class, result_array, max_value);
        foreach (int primnums; result_array){
            setattrib(geoself(), 'prim', 'max_value', primnums, 0, max_value, 'set');
        }
        prim = max_value;
    }
    else {
        target_class += 1;
        int max_value = 0;
        int result_array[] = {};
        performLoop(class_attrib, prim, target_class, result_array, max_value);
        foreach (int primnums; result_array){
            setattrib(geoself(), 'prim', 'max_value', primnums, 0, max_value, 'set');
        }
        prim = max_value;
    }
}

int prims[] = findattribval(0, "prim", "class", i@class);
i@largest_primnum_in_class = prims[-1];