auto_craft_concrete.lua

local function sync()
    -- print("sync")
    local init_slot = turtle.getSelectedSlot() -- 退避
    local found_slot = 0
    for i = 1, 16 do
        -- print("sync:: slot:"..i.." found slot:"..found_slot)
        local info = turtle.getItemDetail(i)
        if info then
            if info.name == "minecraft:concrete" then
                turtle.select(i)
                turtle.dropUp()
            elseif (found_slot == 0) and (info.name == "minecraft:concrete_powder") then
                found_slot = i
                -- print("sync:: found")
            end
        end
    end
    turtle.select(init_slot)
    return found_slot
end

local function place_and_dig_impl()
    -- print("place_and_dig_impl")
    turtle.dig()
    while 0 < turtle.getItemCount() do
        local info = turtle.getItemDetail(i)
        if (not info) or (info.name ~= "minecraft:concrete_powder") then break end
        local re, message = turtle.place()
        if not re then return re, message end
        os.sleep(0.2)
        while true do
            local re, info = turtle.inspect()
            if re and info ~= nil and info.name == "minecraft:concrete" then
                break
            end
            os.sleep(0.1)
        end
        re, message = turtle.dig()
        if not re then return re, message end
    end
    return true
end

---@param slot integer
local function place_and_dig(slot)
    local init_slot = turtle.getSelectedSlot() -- 退避
    turtle.select(slot)
    local re, message = place_and_dig_impl()
    turtle.select(init_slot)
    return re, message
end
local function main()
    while true do
        local slot = sync()
        if slot ~= 0 then
            local re, message = place_and_dig(slot)
            if not re then return re, message end
        else
            os.sleep(2)
        end
    end
    return true
end
local re, message = main()
if not re then print(message) end