Ten by Ten dig

-- Digs a 10x10x3 room.
-- Meant for quick excavation, not mass harvesting.

-- Use odd numbers for it to return to its starting point
roomSize = 9

-- Tracks the turtle's position
turtlePos = vector.new(0,0,0)

while turtlePos.y < roomSize do
 -- Dig x column away from baseline
 while turtlePos.x < roomSize do
  while turtle.detect() do
   turtle.dig()
  end
  -- Dig forward
  while not turtle.forward() do
   os.sleep(1)
  end
  turtlePos.x = turtlePos.x + 1
  turtle.digUp()
  turtle.digDown()
 end

 -- Move to the right 1 Y column.
 turtle.turnRight()
 while turtle.detect() do
  turtle.dig()
 end
 -- Move to the right 1
 while not turtle.forward() do
  os.sleep(1)
 end
 turtlePos.y = turtlePos.y + 1
 turtle.digUp()
 turtle.digDown()

 -- Turn again to continue digging.
 turtle.turnRight()

 -- Dig x column back to baseline
 while turtlePos.x > 1 do
  while turtle.detect() do
   turtle.dig()
  end
  -- Dig forward
  while not turtle.forward() do
   os.sleep(1)
  end
  turtlePos.x = turtlePos.x - 1
  turtle.digUp()
  turtle.digDown()
 end

 if turtlePos.y < roomSize then
  -- Move to the right 1 if we haven't finished the dig.
  turtle.turnLeft()
  while turtle.detect() do
   turtle.dig()
  end

  while not turtle.forward() do
   os.sleep(1)
  end
  turtlePos.y = turtlePos.y + 1
  turtle.digUp()
  turtle.digDown()
  turtle.turnLeft()
 end
end

-- Return home
turtle.turnRight()
while turtlePos.y > 0 do
 while turtle.detect() do
  turtle.dig()
 end
 -- Dig forward
 while not turtle.forward() do
  os.sleep(1)
 end
 turtlePos.y = turtlePos.y - 1
end

turtle.turnRight()