function isblock_f(id)
	local success, data = turtle.inspect()
	if success then
		if id == data.name then
			return true
		end
	end
end

function isblock_l(id)
	turtle.turnLeft()
	local success, data = turtle.inspect()
	turtle.turnRight()
	if success then
		if id == data.name then
			return true
		end
	end
end

function isblock_r(id)
	turtle.turnRight()
	local success, data = turtle.inspect()
	turtle.turnLeft()
	if success then
		if id == data.name then
			return true
		end
	end
end

function isblock_u(id)
	local success, data = turtle.inspectUp()
	if success then
		if id == data.name then
			return true
		end
	end
end

function isblock_d(id)
	local success, data = turtle.inspectDown()
	if success then
		if id == data.name then
			return true
		end
	end
end

function isblock_b(id)
	turtle.turnLeft()
	turtle.turnLeft()
	local success, data = turtle.inspect()
	turtle.turnRight()
	turtle.turnRight()
	if success then
		if id == data.name then
			return true
		end
	end
end

-- Stack Table
-- Uses a table as stack, use <table>:push(value) and <table>:pop()
-- Lua 5.1 compatible

-- GLOBAL
Stack = Core.class()

function Stack:init(list)

  if not list then
    -- create an empty stack
    self.stack = {}
  else
    -- initialise the stack
    self.stack = list
  end
end

function Stack:push(item)
  -- put an item on the stack
  self.stack[#self.stack+1] = item
end

function Stack:pop()
  -- make sure there's something to pop off the stack
  if #self.stack > 0 then
    -- remove item (pop) from stack and return item
    return table.remove(self.stack, #self.stack)
  end
end

function Stack:iterator()
  -- wrap the pop method in a function
  return function()
    -- call pop to iterate through all items on a stack
    return self:pop()
  end
end

orestack = Stack.new()

function minevein(id)
	if isblock_f(id) then
		print("f")
		turtle.dig()
		orestack:push("f")
		turtle.forward()
		return minevein(id)
	end
	if isblock_u(id) then
		print("u")
		turtle.digUp()
		orestack:push("u")
		turtle.up()
		return minevein(id)
	end
	if isblock_d(id) then
		print("d")
		turtle.digDown()
		orestack:push("d")
		turtle.down()
		return minevein(id)
	end
	turtle.turnLeft()
	if isblock_f(id) then
		print("l")
		turtle.dig()
		orestack:push("l")
		turtle.forward()
		return minevein(id)
	end
	turtle.turnLeft()
	if isblock_f(id) then
		print("b")
		turtle.dig()
		orestack:push("b")
		turtle.forward()
		return minevein(id)
	end
	turtle.turnLeft()
	if isblock_f(id) then
		print("r")
		turtle.dig()
		orestack:push("r")
		turtle.forward()
		return minevein(id)
	end

	last_mov = orestack:pop()
	if last_mov then
		if last_mov == "u" then
			turtle.down()
			return minevein(id)
		elseif last_mov == "d" then
			turtle.up()
			return minevein(id)
		else
			turtle.back()
			return minevein(id)
		end
	end
end

turtle.refuel(5)
print(turtle.getFuelLevel())
minevein("minecraft:dirt")