Lua大数加法：字符串模拟的逐位进位

local s = tonumber(a) + tonumber(b)   -- 超 2^53 失真

local function bigAdd(a, b)
    local carry, out = 0, {}
    local i, j = #a, #b
    while i > 0 or j > 0 or carry > 0 do
        local da = i > 0 and tonumber(a:sub(i, i)) or 0
        local db = j > 0 and tonumber(b:sub(j, j)) or 0
        local s = da + db + carry
        carry = math.floor(s / 10)
        table.insert(out, s % 10)
        i, j = i - 1, j - 1
    end
    return table.concat(out):reverse()
end
local p = getplayerbyname("ledger01")
sendmsg(p, 1, bigAdd("9007199254740993", "1"))