Tail recursion in lua

Tail recursion ex.lua

function countdwn(n)
    while n>0 do
        print(n)
        countdwn(n-1)
    else
        print("0")
    end
end

--[[
Usage: countdwn(natural number)

> countdwn(10)
10
9
8
7
6
5
4
3
2
1
0
>
--]]