Wall Placer (ComputerCraft)

local slot = 1
local levels = 2

function turnAround()
  turtle.turnLeft()
  turtle.turnLeft()
end

function placeToEnd()
  while true do
    items = turtle.getItemCount(slot)
    if items == 0 then
      if slot == 16 then
        print("Out of all bricks")
        return false
      else
        slot = slot + 1
        turtle.select(slot)
        print("Selected slot #", slot)
      end
    else
      moved = turtle.back()
      if not moved then
        return true
      end

      turtle.place()
    end
  end
end

-- Run into wall
turtle.select(slot)
for i=1,levels do
  out = placeToEnd()
  if not out then
    break
  end

  print("Moving up level")
  turtle.up()
  turnAround()
end