Coord based travel on turtle

--start: -275 69 351
--farm: -257 72 385
raise = 10
farmLength = 13
lane = 7

shell.run("clear")
print("Searching for location...")
--x, y, z = gps.locate(10)
x = nil
shell.run("clear")
if x == nil then
    print("Search failed.. Reverting to manual input.")
    write("X: ")
    x = read()
    write("Y: ")
    y = read()
    write("Z: ")
    z = read()
else
    print("Location retrieved!")
end
write("Direction: ")
direction = read()

print("")
print("Specify destination..")
write("X: ")
xGo = read()
write("Y: ")
yGo = read()
write("Z: ")
zGo = read()
write("Direction: ")
dGo = read()

function vertical(dir,amount)
    repeat
        if dir == 1 then
            turtle.up()
        else
            turtle.down()
        end
        amount = amount - 1
    until amount == 0
end

function switchLane(dir)
    if dir == "right" then
        turtle.turnRight()
        turtle.forward()
        turtle.turnRight()
    elseif dir == "left" then
        turtle.turnLeft()
        turtle.forward()
        turtle.turnLeft()
    end
end

function farmIt(forward)
    turtle.select(1)
    turtle.digDown()
    turtle.select(2)
    turtle.placeDown()

    if forward then
        turtle.forward()
    end
end

function go(amount)
    repeat
        amount = amount - 1
        turtle.forward()
    until amount == 0
end

function placeIn(slot)
    turtle.suck()
    amount = turtle.getItemCount(slot)
    turtle.drop(amount-1)
end

function face(num)
    while direction ~= num do
        if direction == 3 then
            direction = 0
        else
            direction = direction + 1
        end
        turtle.turnRight()
    end
end

function goto(x1,y1,z1,f)
    vertical(1,raise)

    if x1 > x then
      face(3)
      go(x1-x)
    end
    if x1 < x then
      face(1)
      go(x-x1)
    end
    if z1 > z then
      face(0)
      go(z1-z)
    end
    if z1 < z then
      face(2)
      go(z-z1)
    end

    vertical(0,raise)
    --if y1 > y then
      --vertical(1,y1-y)
    --end
    --if y1 < y then
      --vertical(0,y-y1)
    --end

    face(f)
    x = x1
    y = y1
    z = z1
    direction = f
end

function farm(direc, last)
    amount = farmLength-1
    repeat
        farmIt(true)
        amount = amount - 1
    until amount == 0
    farmIt(false)

    if not last then
        if direc == "right" then
            switchLane("right")
        elseif direc == "left" then
            switchLane("left")
        end
    end
end

function completeFarm(lanes)
    turn = "right"
    for x=1,lanes do
        if x == lanes then
            farm(turn, true)
        else
            farm(turn, false)
        end

        if turn == "right" then
            turn = "left"
        elseif turn == "left" then
            turn = "right"
        end
    end
end

goto(xGo,yGo,zGo,dGo)

print("Press any key to launch..")
repeat
    local event = os.pullEvent()
until event == "key"

x = -263
y = 72
z = 397
direction = 0

xGo = -275
yGo = 69
zGo = 351
dGo = 2

goto(xGo,yGo,zGo,dGo)