[Lua][Error][Turtle]Sometimes works and Sometimes dosnt

I am trying to run this code which makes a platform, sometimes when I run it, it automatically goes to "Error: block in the way", but also sometimes it does not, the first time I ever ran it, it ran flawlessly, but I tried a second time and it failed; it also sometimes just stops and gives me the error "Error: block in the way" when there is not a block in the way.

After it gives me the "Error: block in the way" I goto the lua interpreter and type turtle.forward() but it comes up with "false" when I do it even when it should not.

I have the correct slots filled too.

local blocks = turtle.getItemCount(2)
for slot=3,16 do
  if turtle.compareTo(2) then
	blocks = blocks + turtle.getItemCount(slot)
  end
end
size = math.floor(math.sqrt(blocks))
sizeStr = tostring(size)
print("Making a " .. sizeStr .. "x" .. sizeStr .. " platform")
function prevBlockSlot(curSlot)
  for slot=curSlot,2,-1 do
	turtle.select(slot)
	if turtle.compareTo(2) then
	  return slot
	end
  end
end
function forward(curSlot)
  if turtle.getFuelLevel() < 1 then
	select(1)
	turtle.refuel(1)
	turtle.select(curSlot)
  end
  for i=1,10 do
	if turtle.detect() then
	  turtle.dig()
	end
	if turtle.forward() then
	  return true
	end
  end
  return nil
end
function placeDown(curSlot)
  if not turtle.compareTo(2) then
	curSlot = prevBlockSlot(curSlot)
  end
  turtle.placeDown()
  return curSlot
end
local curSlot = prevBlockSlot(16)
for row=1,size do
  for i=1,size-1 do
	curSlot = placeDown(curSlot)
	if not forward(curSlot) then
	  print("Error: block in the way")
	  return
	end
  end
  curSlot = placeDown(curSlot)
  if row%2 == 1 then
	turtle.turnRight()
	if not forward(curSlot) then
	  print("Error: block in the way")
	  return
	end
	turtle.turnRight()
  else
	turtle.turnLeft()
	if not forward(curSlot) then
	  print("Error: block in the way")
	  return
	end
	turtle.turnLeft()
  end
end

i usually do something like this whenever i try to go forward:

while not turtle.forward() do turtle.dig() end

PixelToast, on 24 December 2012 - 02:24 PM said:

i usually do something like this whenever i try to go forward:

while not turtle.forward() do turtle.dig() end

Sorry if this a stupid question, but where would I put that if I added it.

in replace to turtle.forward()
it will ensure that turtle.forward() always returns true
it might crash if it reaches an unloaded chunk though

The forward function should already be doing that.

function forward(curSlot)
  if turtle.getFuelLevel() < 1 then
	    select(1)
	    turtle.refuel(1)
	    turtle.select(curSlot)
  end
  for i=1,10 do
	    if turtle.detect() then
		  turtle.dig()
	    end
	    if turtle.forward() then
		  return true
	    end
  end
  return nil
end

This function doesn't deal with mobs. Is there a chance that you're running into spawned mobs, and that's causing forward to fail?

ChunLing, on 24 December 2012 - 06:17 PM said:

The forward function should already be doing that.

function forward(curSlot)
  if turtle.getFuelLevel() < 1 then
		select(1)
		turtle.refuel(1)
		turtle.select(curSlot)
  end
  for i=1,10 do
		if turtle.detect() then
		  turtle.dig()
		end
		if turtle.forward() then
		  return true
		end
  end
  return nil
end

This function doesn't deal with mobs. Is there a chance that you're running into spawned mobs, and that's causing forward to fail?

That could be it, but I am right next to a village but I have not had any villagers come right in front of my turtle.

And you've placed fuel in slot 1, or have enough fuel for that not to matter, right?

ChunLing, on 25 December 2012 - 01:20 AM said:

And you've placed fuel in slot 1, or have enough fuel for that not to matter, right?

Yes, I also run into a problem that it sometimes builds a 8x8(even when I am full of cobble).

Hmm…could it be that one of your other mods is interfering with the turtle functions somehow? That's all I can think of.