View difference between Paste ID: C316Cyef and z6HYeDgD

 MiningTurtle = {
 	position = {
 		x = 0,
 		y = 0,
 		z = 0
 	},
 	direction = 0
 }
 
 -- Check if the Turtle needs to be refueled ( <= refuelLevel )
 -- if yes, try to refuel it taking the contents of the inventory
 -- if this is not possible or not enough, go back to base
 function MiningTurtle:requiredRefuel( refuelLevel, requiredFuelLevel )
 
 	if refuelLevel == nil then
 		refuelLevel 		= 25
 	end
 
 	if requiredFuelLevel == nil then
 		requiredFuelLevel 	= 500
 	end
 
 	-- should we refuel?
 	if turtle.getFuelLevel() <= refuelLevel then
 
 		-- iterate through our inventory
 		for slot = 1,16 do
 
 			-- select slot
 			turtle.select(slot)
 
 			-- refuel from active slot...
 			if turtle.refuel( turtle.getItemCount( slot ) ) then
 
 			end
 
 			-- ...and check again
 			if turtle.getFuelLevel() >= requiredFuelLevel then
 				return true
 			end
 
 		end
 
 		-- check if we did not refueled enough alreay
-		if not turtle.getFuelLevel() >= requiredFuelLevel then
+		if not (turtle.getFuelLevel() >= requiredFuelLevel) then
 			-- if yes, go back to base
 
 			MiningTurtle:toBase()
 			-- refuel: to be implemented!!!!
 		end
 	end
 
 	return false
 end
 
 -- Go back to the base of the MiningTurtle
 function MiningTurtle:toBase( )
 
 end
 
 -- Go to ground
 function MiningTurtle:toGround( )
 
 	while not turtle.detectDown() do
 		MiningTurtle:down()
 	end
 
 end
 
 -- forward
 function MiningTurtle:forward()
 	local ret
 
 	ret = turtle.forward()
 
 	if ret then
 
 
 		if self.direction == 0 then
 
 			self.position.x = self.position.x + 1
 
 		elseif self.direction == 90 then
 
 			self.position.y = self.position.y + 1
 
 		elseif self.direction == 180 then
 
 			self.position.x = self.position.x - 1
 
 		elseif self.direction == 270 then
 
 			self.position.y = self.position.y - 1
 
 		end
 
 	end
 
 	return ret
 end
 
 -- back
 function MiningTurtle:back()
 	local ret
 
 	ret = turtle.back()
 
 	if ret then
 
 		if self.direction == 0 then
 
 			self.position.x = self.position.x - 1
 
 		elseif self.direction == 90 then
 
 			self.position.y = self.position.y - 1
 
 		elseif self.direction == 180 then
 
 			self.position.x = self.position.x + 1
 
 		elseif self.direction == 270 then
 
 			self.position.y = self.position.y + 1
 
 		end
 
 	end
 
 	return ret
 end
 
 -- up
 function MiningTurtle:up()
 	local ret
 
 	ret = turtle.up()
 
 	if ret then
 		self.position.z = self.position.z + 1
 	end
 
 	return ret
 end
 
 -- down
 function MiningTurtle:down()
 	local ret
 
 	ret = turtle.down()
 
 	if ret then
 		self.position.z = self.position.z - 1
 	end
 
 	return ret
 end
 
 -- turn Left
 function MiningTurtle:turnLeft()
 	local ret
 
 	ret = turtle.turnLeft()
 
 	if ret then
 		self.direction = self.direction + 90
 
 		while self.direction >= 360 do
 			self.direction = self.direction - 360
 		end
 	end
 
 	return ret
 end
 
 -- turn Right
 function MiningTurtle:turnRight()
 	local ret
 
 	ret = turtle.turnRight()
 
 	if ret then
 		self.direction = self.direction - 90
 
 		while self.direction < 0 do
 			self.direction = self.direction + 360
 		end
 	end
 
 	return ret
 end
 
 -- Save forward
 function MiningTurtle:saveForward()
 
 	while not MiningTurtle:forward() do
 		turtle.dig()
 	end
 end
 
 -- Save up
 function MiningTurtle:saveUp()
 
 	while not MiningTurtle:up() do
 		turtle.digUp()
 	end
 end
 
 -- Save down
 function MiningTurtle:saveDown()
 
 	while not MiningTurtle:down() do
 		turtle.digDown()
 	end
 end
 
 -- 180 degree turn
 function MiningTurtle:turn()
 
 	MiningTurtle:turnRight()
 	MiningTurtle:turnRight()
 end
 
 -- Make a tunnel
 function MiningTurtle:tunnel( length, height, width, ret )
 
 	if height == nil then
 		height 	= 2
 	end
 
 	if height == nil then
 		height 	= 2
 	end
 
 	if ret == nil then
 		ret 	= false
 	end
 
 	-- Length loop
 
 	for i = 1,length do
 
 		MiningTurtle:saveForward()
 
 		if i % 2 == 0 then
 			-- even
 
 			MiningTurtle:turnLeft()
 
 			for x = 0,width do
 
 				for y = 0,height do
 
 					if x % 2 == 0 then
 						MiningTurtle:saveUp()
 					else
 						MiningTurtle:saveDown()
 					end
 
 				end
 
 				if x < width then
 					MiningTurtle:saveForward()
 				end
 			end
 
 			MiningTurtle:turnRight()
 
 		else
 			-- odd
 
 			MiningTurtle:turnRight()
 
 			for x = 0,width do
 
 				for y = 0,height do
 
 					if x % 2 == 0 then
 						MiningTurtle:saveUp()
 					else
 						MiningTurtle:saveDown()
 					end
 
 				end
 
 				if x < width then
 					MiningTurtle:saveForward()
 				end
 			end
 
 			MiningTurtle:turnLeft()
 
 		end
 
 	end
 
 	if ret then
 
 		MiningTurtle:turn()
 	end
 
 end
 
 
 --
 function MiningTurtle:matrix( rows, cols )
 
 
 
 end
 
 
 -- main
 
 while not MiningTurtle:requiredRefuel() do
 	print("Waiting for MiningTurtle to have enough fuel")
 end
 
 MiningTurtle:toGround()
 MiningTurtle:tunnel(10)