Turtle autocrushing/smelting 0.01

function isEmpty()
    if nextStack() == -1 then
        return True
    end
    return False
end

function nextStack()
    for k = turtle.getSelectedSlot() + 1,16 do
        if turtle.getItemCount(k) > 0 then
            return k
        end
    end
    return -1
end

while true do
    chest = peripheral.wrap("back") --chest loc
  if next(chest.getAllStacks()) ~= nill then
        --main procedure

        turtle.select(1)
        chest.condenseItems()
        for k = 1,16 do chest.pushItem("north", k, 32, k)  end
        for k = 1,3 do turtle.forward() end

        crush = peripheral.wrap("front")
        while isEmpty() == True do
            x = turtle.getItemCount(turtle.getSelectedSlot())
            crush.pullItem("south", turtle.getSelectedSlot())
            while next(crush.getAllStacks()) ~= nill do
                for k = 2,5 do
                    crush.pushItem("south", k)
                end
            end
            if nextStack() == -1 then break end
            turtle.select(nextStack())
        end

        turtle.turnRight()
        turtle.forward()
        turtle.turnLeft()

        turtle.select(1)
        furn = peripheral.wrap("front")
        while isEmpty() == True do
            x = turtle.getItemCount(turtle.getSelectedSlot())
            furn.pullItem("south", turtle.getSelectedSlot())
            while next(crush.getAllStacks()) ~= nill do
                for k = 2,3 do
                    furn.pushItem("south", k)
                end
            end
            if nextStack() == -1 then break end
            turtle.select(nextStack())
        end

        turtle.turnRight()
        turtle.back()
        turtle.back()
        turtle.turnLeft()

        turtle.back()
        turtle.back()

        for k = 1,16 do peripheral.wrap("back").pullItem("north", k) end

        turtle.turnLeft()
        turtle.back()
        turtle.turnRight()


    end
    turtle.turnLeft()
    turtle.turnRight()
end