Simple Lua 5.2+ module that enables tables to be reused

tablestorage.lua

--[[
Reasoning:
If your program uses (and stops using) a lot of tables, you will be dealing with the memory allocation and deallocation overhead,
Roberto Ierusalimschy suggests "recycling" tables as a way of optimizing code that uses a lot of them. This small module uses the
__gc metamethod (enabled for tables in version 5.2) to know whenever a table isn't being used anymore and stores it for future use,
avoiding an extra deallocation and future allocation of a new table. If you aren't sure that this module will help your code's
performance, do not use it because it might backfire on your goals. Even then you should customize the table clean up (or not clean
them at all) depending on what your are going to use them for.

Usage:
local tablestorage = require('tablestorage')

-- mt: metatable the new table should have
-- array: if true, it is assumed the new table will only have array elements
local t, mt = tablestorage(mt, array)
-- returns an empty table and its metatable

-- Testing:
local list = {}
while true do
	io.write('> ')
	local input = io.read()
	if input == 'q' or input == 'quit' then
		break
	elseif input:sub(1, 4) == 'add ' then
		local entry = tablestorage()
		entry.name = input:sub(5)
		table.insert(list, entry)
	elseif input:sub(1, 3) == 'rm ' then
		local cmp = input:sub(4)
		for k, v in ipairs(list) do
			if v.name == cmp then
				table.remove(list, k)
				break
			end
		end
	elseif input:sub(1, 4) == 'list' then
		for _, v in ipairs(list) do
			print(v.name, v)
		end
	elseif input:sub(1, 7) == 'collect' then
		collectgarbage()
	else
		print 'Incorrect input'
	end
end

-- Output:
> add t1
> add t2
> list
t1      table: 0000000000a39870
t2      table: 0000000000a39e30
> rm t2
> collect
> add t3
> list
t1      table: 0000000000a39870
t3      table: 0000000000a39e30
]]

local storage = {}

return function(mt, array)
	mt = mt or {}
	local finalizer = mt.__gc
	mt.__gc = function(self)
		if finalizer then
			finalizer(self)
		end

		local iter = array and ipairs or pairs
		for k, _ in iter(self) do
			self[k] = nil
		end

		table.insert(storage, self)
	end

	return setmetatable(table.remove(storage, #storage) or { }, mt)
end