registerWeapon glua

-- Base SWEP system
weapons = {}
function registerWeapon(data)
    weapons[data.name] = data
end

-- Your SWEP
registerWeapon {
    name = "my_super_weapon",
    primary_attack = function()
        print ("Pew Pew")
    end
}

-- Activate primary attack of every registered weapon
for _, weapon in pairs (weapons) do
    if weapon.primary_attack then
        weapon.primary_attack()
    end
end