View difference between Paste ID: Tc1y7HxT and E6CPFSrR

-print("Program 1, Hello")
+-- Turtle API http://computercraft.info/wiki/Turtle_(API)
 -- Turtle Functions
 local depth = 0
 local unloaded = 0
 local collected = 0
 
 local xPos,zPos = 0,0
 local xDir,zDir = 0,1
 
 local goTo -- Filled in further down
 local refuel -- Filled in further down
 
 local function unload( _bKeepOneFuelStack )
 	print( "Unloading items..." )
 	for n=1,16 do
 		local nCount = turtle.getItemCount(n)
 		if nCount > 0 then
 			turtle.select(n)
 			local bDrop = true
 			if _bKeepOneFuelStack and turtle.refuel(0) then
 				bDrop = false
 				_bKeepOneFuelStack = false
 			end
 			if bDrop then
 				turtle.drop()
 				unloaded = unloaded + nCount
 			end
 		end
 	end
 	collected = 0
 	turtle.select(1)
 end
 local function returnSupplies()
 	local x,y,z,xd,zd = xPos,depth,zPos,xDir,zDir
 	print( "Returning to surface..." )
 	goTo( 0,0,0,0,-1 )
 
 	local fuelNeeded = 2*(x+y+z) + 1
 	if not refuel( fuelNeeded ) then
 		unload( true )
 		print( "Waiting for fuel" )
 		while not refuel( fuelNeeded ) do
 			sleep(1)
 		end
 	else
 		unload( true )
 	end
 
 	print( "Resuming mining..." )
 	goTo( x,y,z,xd,zd )
 end
 
 local function collect()
 	local bFull = true
 	local nTotalItems = 0
 	for n=1,16 do
 		local nCount = turtle.getItemCount(n)
 		if nCount == 0 then
 			bFull = false
 		end
 		nTotalItems = nTotalItems + nCount
 	end
 
 	if nTotalItems > collected then
 		collected = nTotalItems
 		if math.fmod(collected + unloaded, 50) == 0 then
 			print( "Mined "..(collected + unloaded).." items." )
 		end
 	end
 
 	if bFull then
 		print( "No empty slots left." )
 		return false
 	end
 	return true
 end
 function refuel( ammount )
 	local fuelLevel = turtle.getFuelLevel()
 	if fuelLevel == "unlimited" then
 		return true
 	end
 
 	local needed = ammount or (xPos + zPos + depth + 2)
 	if turtle.getFuelLevel() < needed then
 		local fueled = false
 		for n=1,16 do
 			if turtle.getItemCount(n) > 0 then
 				turtle.select(n)
 				if turtle.refuel(1) then
 					while turtle.getItemCount(n) > 0 and turtle.getFuelLevel() < needed do
 						turtle.refuel(1)
 					end
 					if turtle.getFuelLevel() >= needed then
 						turtle.select(1)
 						return true
 					end
 				end
 			end
 		end
 		turtle.select(1)
 		return false
 	end
 
 	return true
 end
 local function tryForwards()
 	if not refuel() then
 		print( "Not enough Fuel" )
 		returnSupplies()
 	end
 
 	while not turtle.forward() do
 		if turtle.detect() then
 			if turtle.dig() then
 				if not collect() then
 					returnSupplies()
 				end
 			else
 				return false
 			end
 		elseif turtle.attack() then
 			if not collect() then
 				returnSupplies()
 			end
 		else
 			sleep( 0.5 )
 		end
 	end
 
 	xPos = xPos + xDir
 	zPos = zPos + zDir
 	return true
 end
 
 local function tryDown()
 	if not refuel() then
 		print( "Not enough Fuel" )
 		returnSupplies()
 	end
 
 	while not turtle.down() do
 		if turtle.detectDown() then
 			if turtle.digDown() then
 				if not collect() then
 					returnSupplies()
 				end
 			else
 				return false
 			end
 		elseif turtle.attackDown() then
 			if not collect() then
 				returnSupplies()
 			end
 		else
 			sleep( 0.5 )
 		end
 	end
 
 	depth = depth + 1
 	if math.fmod( depth, 10 ) == 0 then
 		print( "Descended "..depth.." metres." )
 	end
 
 	return true
 end
 
 local function turnLeft()
 	turtle.turnLeft()
 	xDir, zDir = -zDir, xDir
 end
 
 local function turnRight()
 	turtle.turnRight()
 	xDir, zDir = zDir, -xDir
 end
 
 function goTo( x, y, z, xd, zd )
 	while depth < y do
 		if turtle.down() then
 			depth = depth + 1
 		elseif turtle.digDown() or turtle.attackDown() then
 			collect()
 		else
 			sleep( 0.5 )
 		end
 	end
 
 	if xPos > x then
 		while xDir ~= -1 do
 			turnLeft()
 		end
 		while xPos > x do
 			if turtle.forward() then
 				xPos = xPos - 1
 			elseif turtle.dig() or turtle.attack() then
 				collect()
 			else
 				sleep( 0.5 )
 			end
 		end
 	elseif xPos < x then
 		while xDir ~= 1 do
 			turnLeft()
 		end
 		while xPos < x do
 			if turtle.forward() then
 				xPos = xPos + 1
 			elseif turtle.dig() or turtle.attack() then
 				collect()
 			else
 				sleep( 0.5 )
 			end
 		end
 	end
 
 	if zPos > z then
 		while zDir ~= -1 do
 			turnLeft()
 		end
 		while zPos > z do
 			if turtle.forward() then
 				zPos = zPos - 1
 			elseif turtle.dig() or turtle.attack() then
 				collect()
 			else
 				sleep( 0.5 )
 			end
 		end
 	elseif zPos < z then
 		while zDir ~= 1 do
 			turnLeft()
 		end
 		while zPos < z do
 			if turtle.forward() then
 				zPos = zPos + 1
 			elseif turtle.dig() or turtle.attack() then
 				collect()
 			else
 				sleep( 0.5 )
 			end
 		end
 	end
 
 	while depth > y do
 		if turtle.up() then
 			depth = depth - 1
 		elseif turtle.digUp() or turtle.attackUp() then
 			collect()
 		else
 			sleep( 0.5 )
 		end
 	end
 
 	while zDir ~= zd or xDir ~= xd do
 		turnLeft()
 	end
 end
 -- Functions
 function dedif(tf)
    if turtle.detect() then
       turtle.dig()
    end
    if tf then
       tryForwards()
    end
 end
 
 function turnLeftRight(left)
    if left then
       turnLeft()
    else
       turnRight()
    end
 end
 
 function lineCut(left)
    turnLeftRight(left)
    dedif(true)
    turnLeftRight(left)
    for i=1, 8 do -- dig 8 times in a line
       dedif(true)
    end
 end
 
 
 -- Main Program
 height = 50 -- right around the base of the leaves level
 for full=1, height do -- run though the entire tree
    if not refuel() then
       print( "Out of Fuel" )
       return
    end
    turnLeft()
    for i=1, 4 do -- go left 4 times
       dedif(true)
    end
 
    for i=1, 9 do -- cycle through base of tree (tree is 9x9)
       left=false
       -- 1 = false (right)
       -- 2 = true (left)
       if i==1 or i==3 or i==5 or i==7 or i==9 then
          left = false
       else
          left = true
       end
       lineCut(left)
    end
    turnRight()
    for i=1, 9 do -- go 9 forward
       dedif(true)
    end
    turnRight()
    for i=1, 4 do -- go forward 4
       dedif(true)
    end
    turnRight()
    if turtle.detectUp() then
       turtle.digUp()
    end
    turtle.up()
 end -- end full loop