minecraft_place_torch

local i = 0
local slot = 1

while slot < 16 do
    turtle.forward()
    i = i + 1
    if i == 8 then
        if turtle.getItemCount() == 0 then
            slot = slot + 1
            turtle.select(slot)
            if turtle.getItemCount() == 0 then
                os.exit()
            end
        end
        turtle.placeDown()
        i = 0
    end
end