I'm impressed. It seems to be in total working order when trying out collectgarbage, __gc and __mode[0]. Code: print(_VERSION) local a = setmetatable({},

I'm impressed. It seems to be in total working order when trying out collectgarbage, __gc and __mode[0]. Code: print(_VERSION) local a = setmetatable({}, {__mode = 'v'}) local b = setmetatable({}, {__gc = function(x) print("Deleting: " .. tostring(x)) end}) a[1] = b a[2] = 2 print(table.unpack(a)) print(collectgarbage'count') b = nil collectgarbage() print(table.unpack(a)) Result: Lua 5.3 table: 0x50a748 2 21.4033203125 Deleting: table: 0x50a748 nil 2 [0] - 3 features tied to the Lua GC, to simplify, they basically are (respectively): forcefully running the GC, finalizers that run when object is collected and weak refs that don't hold the object alive on their own. Perhaps http://www.lua.org/demo.html http://www.lua.org/demo.html could be replaced with that for users who have JS enabled. Again - just wow, that's really nice, Lua in a browser.