[CC 1.41] Lettuce's Improved Land-Clearing Program

function refuel()
	if turtle.getFuelLevel() < 10 then
	turtle.select(16)
	turtle.refuel(1)
	end
end

function moveForward()
	repeat
	turtle.dig()
	until turtle.forward()
end

function clear()
	local z = 0
	if turtle.detectUp() then
		while turtle.detectUp() do
			repeat
			turtle.digUp()
			until turtle.up()
			z = z+1
		end
			repeat
			turtle.down()
			z = z-1
				if z < 0 then
					repeat
					turtle.up()
					z = z+1
					until z == 0
				end
			until z == 0
	end
end

function test()
	turtle.select(15)
		if turtle.detectDown() then
			turtle.digDown()
		end
		if not turtle.placeDown() then
			turtle.digDown()
			turtle.down()
			turtle.digDown()
			turtle.select(14)
			turtle.placeDown()
			turtle.up()
		end
	turtle.digDown()
end

print "How wide is this foundation?"
	x = tonumber(read())
print "How long?"
	y = tonumber(read())
print "Please place fuel in slot 16, two torches in slot 15, and dirt/stone in 14. Press any key to start."
	os.pullEvent("key")

	x = x-1
	y = y/2
  
refuel()
turtle.turnLeft()
turtle.digUp()
turtle.up()
for i = 1,x/2 do
	test()
	clear()
	moveForward()
	refuel()
end
turtle.turnLeft()
turtle.turnLeft()
for i = 1,x do
	test()
	clear()
	moveForward()
	refuel()
end

for i = 1,y+0.5 do
	turtle.turnLeft()
	test()
	clear()
	moveForward()
	refuel()
	turtle.turnLeft()
	for i = 1,x do
		test()
		clear()
		moveForward()
		refuel()
	end
	turtle.turnRight()
	test()
	clear()
	moveForward()
	refuel()
	turtle.turnRight()
	for i = 1,x do
		test()
		clear()
		moveForward()
		refuel()
	end
end
test()
clear()