Accelerating a Menubar's MenuItems

["Sudrien" <sudrien fusemail com>]

It's fairly easy to add accelerators to items in a menu, while doing a
push_back().

Is there a way to accelerate the top-level menus? Like, select Alt+1 and a
menu opens (as in, it is not a letter in the menu title)? An example of
menus being activated via keyboard?

-Sud.