Tree farm

z = 0

function moveUp()
	if turtle.up() then
		z = z + 1
		return true
	end
end

function moveDown()
	if turtle.down() then
		z = z - 1
		return true
	end
end

function mineUp()
	turtle.dig()
	turtle.digUp()
	moveUp()
end

function dropOff()
	print("Dropping off items..")
	turtle.turnRight()
	turtle.turnRight()
	turtle.select(1)
	turtle.drop(turtle.getItemCount(1)-1)
	turtle.turnRight()
	turtle.turnRight()
end

function chopTree()
	print("Chopping tree.")
	turtle.select(1)
	while turtle.compare() do
		mineUp()
	end
	for i=1,z do
		moveDown()
	end
end

function waitGrow()
	print("Waiting for grow..")
	while not turtle.compare() do
		os.sleep(1)
	end
	print("Tree grew!")
	return true
end

function placeSapling()
	turtle.select(2)
	turtle.place()
	turtle.select(1)
end

function farm()
	placeSapling()
	waitGrow()
	chopTree()
	dropOff()
	os.sleep(1)
end

while true do
	farm()
end