path_object.lua

local function gfx_hud_object_add(name, tab)
    print('gfx_hud_object_add("' .. name .. '", ' .. tostring(tab) .. ')')
end

local function thingy(path)
    self = {
        path = path
    }
    setmetatable(self, {
        __index = function(self, k)
            local path2 = {}
            for k, v in pairs(self.path) do path2[k] = v end
            path2[#path2 + 1] = k
            return thingy(path2)
        end;
        __call = function(self, ...)
            local class_name = '/' .. table.concat(self.path, '/')
            gfx_hud_object_add(class_name, ...)
        end 
    })  
    return self
end 

gfx_hud = thingy({})

gfx_hud.common.blah.whatever.MyThing { }

local gui = gfx_hud.common.gui

gui.RadioButton { }