mine.lua

dist = 8
len = 64

fuel = 16
cobble = 2
torch = 1

if turtle.getFuelLevel() <= 5000 then
    turtle.select(fuel)
    turtle.refuel()
end

for x=0,len do
    turtle.dig()
    turtle.forward()
    turtle.digUp()
    turtle.digDown()
end

turtle.turnLeft()
turtle.turnLeft()
turtle.down()

for x=0,len do
    turtle.select(cobble)
    turtle.placeDown()

    if x % dist == 0 then
        turtle.select(torch)
        turtle.up()
        turtle.placeDown()
        turtle.forward()
        turtle.down()
    else
        turtle.forward()
    end

    turtle.dig()
end

turtle.turnLeft()
turtle.turnLeft()
turtle.up()