Computer Craft: Goto

-- this program is for a turtle and you give it coords and it will go there, just be sure to ahve a gps network set up
local tArgs = {...}
local x = tonumber(tArgs[1])
local y = tonumber(tArgs[2])
local z = tonumber(tArgs[3])
local curx, cury, curz, dir

function getPos()
  return gps.locate(3)
end

function getDir()
  local dir, x, y, z
  x, y, z = getPos()
  while not turtle.forward() do
    while not turtle.up() do
      turtle.digUp()
    end
  end
  nx, ny, nz = getPos()
  --print ("New: "..nx..","..ny..","..nz)
  if (x == nx) then
    if (nz > z) then
      dir = 2
    else
      dir = 0
    end
  else
    if (nx > x) then
       dir = 3
    else
       dir = 1
    end
  end
  return dir
end


function setDir(toDir)
  while toDir ~= dir do
    turtle.turnLeft()
    if dir == 3 then
       dir = 0
    else
       dir = dir+1
    end
  end
end

function moveX()
  distxx = x - curx
  --print(distx)
  if (x > curx) then
     setDir(3)
  else
     setDir(1)
  end
  distx = math.abs(distx)
  --print(distx)

  for i = 1, distx do
    while not turtle.forward() do
      while not turtle.up() do
        turtle.digUp()
      end
    end
  end
end

function moveZ()
  distz = z - curz
  if (z < curz) then
     setDir(0)
  else
     setDir(2)
  end
  distz = math.abs(distz)
  -- print(distz)

  for i = 1, distz do
    while not turtle.forward() do
      while not turtle.up() do
        turtle.digUp()
      end
    end
  end
end

function moveY()
  disty = y - cury
  disty = math.abs(disty)
  if (y < cury) then
    for i = 1, disty do
      while not turtle.down() do
        turtle.digDown()
      end
    end
  else
    for i = 1, disty do
      while not turtle.up() do
        turtle.digUp()
      end
    end
  end
end



if not x or not y or not z then
  print("Must supply X Y Z")
  exit()
end

rednet.open("right")
--print (x..","..y..","..z)
dir = getDir()
curx, cury, curz = getPos()
distx = x - curx
disty = y - cury
distz = z - curz
--print (" Current: "..curx..","..cury..","..curz)
--print ("Distance: ",, distx,,",".. disty..","..distz)

moveX()
curx, cury, curz = getPos()
moveZ()
curx, cury, curz = getPos()
moveY()
curx, cury, curz = getPos()
print("Current: "..curx..","..cury..","..curz)