Heavy Pillars

-- to install/reinstall:
-- pastebin run YmWZcV0e WarrX8Nh pillars.lua

placedBlocks = 0

function fillArray(x, n)
    arr = {}

    for i = 1, n do
        arr[i] = x
    end

    return arr
end

function tryToExecute(actions, autoDig)
    for i = 1, #actions do
        print(i)
        action = actions[i]

        if autoDig then
            flag, e = nil, nil

            if action == turtle.forward then
                flag, e = turtle.dig()
            elseif action == turtle.back then
                flag, e = tryToExecute({turtle.turnLeft, turtle.turnLeft, turtle.dig, turtle.turnLeft, turtle.turnLeft}, false)
            elseif action == turtle.up then
                flag, e = turtle.digUp()
            elseif action == turtle.down then
                flag, e = turtle.digDown()
            end

            if not flag and not e == "Nothing to dig here" then
                return false, e
            end
        end

        flag, e = action()

        ignore = action == turtle.digDown or action == turtle.dig or action == turtle.digUp

        if not ignore then
            if action == turtle.place or action == turtle.placeDown or action == turtle.placeUp then
                ignore = true
            end
        end

        if not ignore and not flag then
            return false, e
        end
    end
    return true
end

function findBlock(name)
    item = turtle.getItemDetail()
    if item and item.name == name then
        return true
    end
    for i = 1, 16 do
        item = turtle.getItemDetail(i)
        if item and item.name == name then
            turtle.select(i)
            return true
        end
    end
    return false
end


local forwardActions = fillArray(turtle.forward, 20)

local blockName = "minecraft:cobblestone"

function placeBlock()
    suc, par = turtle.inspect()

    if suc then
        if par.name == blockName then
            return true
        else
            s, e = turtle.dig()
            if not s and not e == "Nothing to dig here" then
                return false, e
            end
        end
    end

    if not findBlock(blockName) then
        return false, "No blocks"
    end

    if turtle.place() then
        placedBlocks = placedBlocks + 1
        return true
    else
        return false
    end
end

function placeBlockDown()
    suc, par = turtle.inspectDown()

    if suc then
        if par.name == blockName then
            return true
        else
            s, e = turtle.digDown()
            if not s then
                return false, e
            end
        end
    end

    if not findBlock(blockName) then
        return false, "No blocks"
    end

    if turtle.placeDown() then
        placedBlocks = placedBlocks + 1
        return true
    else
        return false
    end
end

local pillarBase = {
    turtle.down,
    turtle.forward, placeBlock, turtle.turnLeft, placeBlock, turtle.turnLeft, turtle.forward, turtle.turnLeft,
    turtle.forward, placeBlock, turtle.turnLeft, placeBlock, turtle.turnLeft, turtle.forward, turtle.turnLeft,
    turtle.forward, placeBlock, turtle.turnLeft, placeBlock, turtle.turnLeft, turtle.forward, turtle.turnLeft,
    turtle.forward, placeBlock, turtle.turnLeft, placeBlock, turtle.turnLeft, turtle.forward, turtle.turnLeft,

    placeBlock, turtle.turnLeft, placeBlock, turtle.turnLeft, placeBlock, turtle.turnLeft, placeBlock, turtle.turnLeft,

    turtle.up, placeBlockDown,

    turtle.forward, placeBlock, turtle.turnLeft, placeBlock, turtle.turnLeft, turtle.forward, turtle.turnLeft,
    turtle.forward, placeBlock, turtle.turnLeft, placeBlock, turtle.turnLeft, turtle.forward, turtle.turnLeft,
    turtle.forward, placeBlock, turtle.turnLeft, placeBlock, turtle.turnLeft, turtle.forward, turtle.turnLeft,
    turtle.forward, placeBlock, turtle.turnLeft, placeBlock, turtle.turnLeft, turtle.forward, turtle.turnLeft,

    placeBlock, turtle.turnLeft, placeBlock, turtle.turnLeft, placeBlock, turtle.turnLeft, placeBlock, turtle.turnLeft,

    turtle.up, placeBlockDown
}

local pillarPart = {
    placeBlock, turtle.turnLeft, placeBlock, turtle.turnLeft, placeBlock, turtle.turnLeft, placeBlock, turtle.turnLeft,
    turtle.up, placeBlockDown
}

function goToNext()
    return tryToExecute(forwardActions, false)
end

pillarHeight = 0

function goDownAndCount()
    run = true
    pillarHeight = 0

    while run do
        if turtle.down() then
            pillarHeight = pillarHeight + 1
        else
            run = false
        end
    end

    print("Height: " .. pillarHeight)

    return true
end

tryToExecute({goToNext, goDownAndCount}, false)

function pillarBaseFunc()
    print("Pillar base")
    return tryToExecute(pillarBase, true)
end

function pillarPartsFunc()
    print("Pillar parts")

    for i = 1, pillarHeight - 2 do
        s, e = tryToExecute(pillarPart, true)

        if not s then
            return s, e
        end
    end
    return true
end

if pillarHeight > 0 then
    s, e = tryToExecute({pillarBaseFunc, pillarPartsFunc, turtle.up})

    if not s then
        print(e)
    end
end

print("Placed blocks " .. placedBlocks)