Rails

function power()
    --place a powered rail
    turtle.down()
    --place a earth block first
    turtle.select(15)
    turtle.placeDown()
    turtle.up()
    turtle.turnRight()
    turtle.forward()
    --place a redstone torch, but first a block
    turtle.select(16)
    turtle.down()
    turtle.placeDown()
    turtle.up()
    turtle.select(7)
    if turtle.getItemCount()== 0 then
        turtle.select(8)
    end
    turtle.placeDown()
    turtle.turnLeft()
    turtle.turnLeft()
    turtle.forward()
    turtle.turnRight()
    turtle.select(5)
    if turtle.getItemCount()== 0 then
        turtle.select(6)
    end
    turtle.placeDown()
    turtle.placeDown()
end

function normal()
    turtle.down()
    turtle.select(16)
    turtle.placeDown()
    turtle.up()
    --inventory checks
    local slot= 1
    turtle.select(1)
    while turtle.getItemCount()== 0 do
        slot= slot +1
        turtle.select(slot)
    end
    turtle.placeDown()
end

function pathing()
    path= math.random(1,8)
            --5 and 6 turn, 3 and 7
    if path== 5 then
        turtle.turnLeft()
        turtle.forward()
    elseif path== 6 then
        turtle.turnRight()
        turtle.forward()
    elseif path == 3 or 7 then
        turtle.forward()
        turtle.up()
    elseif path == 2 then
        turtle.forward()
        turtle.down()
    else
        turtle.forward()
    end

end

function makePath(size)
    power()
    for i = 1, size do
        if i%6== 0 then
        --every 6 place a powered rail and go straight ahead
            power()
        else
            pathing()
            normal()
        end
    end
end