Fill a Hole [Turtle]

length = 64
width = 64
left = false
slot = 1

function chestCheck()
  if slot == 16 then
    turtle.placeUp()
    for i = 1, 15 do
      turtle.select(i)
      turtle.suckUp()
    end
    turtle.digUp()
    slot = 1
  else
    slot = slot + 1
  end
end

function slotCheck()
  if turtle.getItemCount() == 0 then
    chestCheck()
    turtle.select(slot)
  end
end

function drop()
  while not turtle.detectDown() do
    slotCheck()
    turtle.placeDown()
  end
end

l = 1
w = 1
while w <= width do
  w = w + 1
  while l <= length do
    l = l + 1
    drop()
    turtle.forward()
  end
  l = 1
  if left do
    turtle.turnLeft()
    turtle.forward()
    turtle.turnLeft()
  else
    turtle.turnRight()
    turtle.forward()
    turtle.turnRight()
  end
  left = not left
end