--betterExcavate, now with support for non-square finite holes! And it won't dump its fuel on the ground!

--Get input
lwh={...}
if lwh[2]==nil then --allow optional second parameter
  lwh[2]=lwh[1]
end
if lwh[3]==nil then --allow optional third parameter
  lwh[3]=2^15
end
for i=1,3 do
  lwh[i]=tonumber(lwh[i])
end
--
local function forward()
  if turtle.getFuelLevel() == 0 then
    if not turtle.refuel() then
      print("I need fuel!")
      while not turtle.refuel() do
        sleep(0.5)
      end
    end
  end
  turtle.dig()
  turtle.forward()
end
--Dig
for h=1,lwh[3] do --height
  for w=1,lwh[2] do --width
    for l=2,lwh[1] do --length
      forward()
    end
    if w==lwh[2] then
      print("Done with this layer!")
    else
      if w%2==1 then
        turtle.turnRight()
        forward()
        turtle.turnRight()
      else
        turtle.turnLeft()
        forward()
        turtle.turnLeft()
      end
    end
  end
  for i=0,lwh[2]%2 do
    turtle.turnRight()
  end
  if h~=lwh[3] then
    turtle.digDown()
    turtle.down()
  end
  if lwh[2]%2==0 then
    l,w,lwh[1],lwh[2]=w,l,lwh[2],lwh[1]
  end
end