wallSwap2.0

local t = turtle

local function dropCheck()
    while true do
        os.sleep(1)
        if t.detect == true then
        t.dig()             --clears falling blocks until there are no more blocks in the space ahead
        else
        break
        end
    end
end

local function reSupply()
    t.select(15)
    t.turnLeft()
    t.dig()
    t.place()

    for i = 9, 14, 1 do         --places red ender chest and gets inventory to place for slots 9-14
        t.select(i)
        t.suck()
    end

    t.select(15)
    t.dig()
    t.turnRight()
end


local function clearInventory()     --places white ender chest and selects inventory slots 1-8 and places them in it

        t.select(16)
        t.turnRight()
        t.dig()
        t.place()

        for i = 1, 8, 1 do
                t.select(i)
                t.drop()
    end

        t.select(16)
        t.dig()
        t.turnLeft()
end

local function matCheck()

    for i = 9, 14, 1 do

        itemCount = t.getItemCount(i)
        t.select(i)
        if itemCount > 0 then

        break end               --if slot 14 has less than 64 supply, the resupply function is run

        if t.getItemCount(14) < 64 then
        reSupply()
        end
    end
end

local function goingUp()

    blockAbove = false

    repeat

    itemCount = t.getItemCount(8)     --checks last open incoming slot and if it has inventory, will clearinventory
        if itemCount > 0 then
            clearInventory()
    end

    matCheck()            --Digs up until a block is detected above the turtle
    t.dig()
    dropCheck()
    t.place()
    t.up()

    if t.detectUp() then
        blockAbove = true
    end

    until blockAbove == true
end

local function keepGoing()

    t.turnRight()
    flag = true

    if t.detect() then          --determines if there is a block to the right of the turtle and stops program
    flag = false                --if there is
    end

    t.turnLeft()
    return flag
end

local function topDown()

    itemCount = t.getItemCount(16)
        if itemCount > 0 then
            clearInventory()
    end                     --positions the turtle at the top of a column to start digging down

    matCheck()
    t.dig()
    t.place()
    t.turnRight()
    t.forward()
    t.turnLeft()
end

local function goingDown()

    blockBelow = false

    repeat

    itemCount = t.getItemCount(8)
    if itemCount > 0 then       --checks inventory and digs down until a block is undearneath
            clearInventory()
    end

    matCheck()
    t.dig()
    t.place()
    t.down()

    if t.detectDown() then
        blockBelow = true
    end

    until blockBelow == true
end

local function bottomUp()

    itemCount = t.getItemCount(8)
        if itemCount > 0 then
            clearInventory()
    end             --positions the turtle at the bottom of next column to start digging up.

    matCheck()
    t.dig()
    t.place()
    t.turnRight()
    t.forward()
    t.turnLeft()
end

--_________________________________END OF FUNCTIONS________________________________________
while true do
    goingUp()
        if keepGoing() == false
            break
        end
    topDown()
    goingDown()
        if keepGoing() == false
            break
        end
    bottomUp()
end