3by3 Tunnel

tunnelLengthMax = 32
turn = 1
tunnelLengthCurrent = tunnelLengthMax
placeTorch = 10
kill = 0
ending = false

function left()
  turtle.turnLeft()
end

function right()
  turtle.turnRight()
end

function moveForward()
  while turtle.detect() do
    turtle.dig()
  end
  moved = false
  while not(moved) do
    moved = turtle.forward()
  end
end

function digForward()
  while turtle.detect() do
    turtle.dig()
  end
end

function digBelow()
  while turtle.detectDown() do
    turtle.digDown()
  end
end

function digAbove()
  while turtle.detectUp() do
    turtle.digUp()
  end
end

function moveUp()
  turtle.digUp()
  moved = false
  while not(moved) do
    turtle.up()
    moved = turtle.up()
  end
end

function moveDown()
  turtle.digDown()
  moved = false
  while not(moved) do
    moved = turtle.down()
  end
end

function leftDig()
    turtle.turnLeft()
    moveForward()
    digAbove()
    digBelow()
    turtle.turnLeft()
  end

  function rightDig()
    turtle.turnRight()
    moveForward()
    digAbove()
    digBelow()
    turtle.turnRight()
  end

while true do
  if tunnelLengthCurrent > 0 and ending == false then
    moveForward()
    digAbove()
    digBelow()
    placeTorch = placeTorch - 1
    tunnelLengthCurrent = tunnelLengthCurrent - 1
    if placeTorch <= 0 then
      placeTorch = 10
      turtle.placeDown()
    end
  end
  if tunnelLengthCurrent <= 0 and turn == 1 then
    rightDig()
    tunnelLengthCurrent = tunnelLengthMax
    kill = kill + 1
    turn = 2
  end
  if tunnelLengthCurrent <= 0 and turn == 2 then
    leftDig()
    tunnelLengthCurrent = tunnelLengthMax
    kill = kill + 1
    turn = 3
  end
  if tunnelLengthCurrent <= 0 and turn == 3 then
    tunnelLengthCurrent = tunnelLengthMax
    leftDig()
    right()
    moveForward()
    left()
    while tunnelLengthCurrent > 0 do
      moveForward()
      tunnelLengthCurrent = tunnelLengthCurrent - 1
    end
    kill = 3
    turn = 4
  end
  if kill == 3 then
    error()
  end
end