RE: GC order

["Nick Trout" <nick@...>]

> So Lua is free of circularity problems? Does this mean that 
> if A referred to B and B referred to A, there is a way in Lua 
> one can somehow cause garbage-collection on either A or B? I 
> was under impression it would have been the case where 
> neither one would get GCed. I guess I am not sure what a 
> circularity problem is. Hmm...

They are collected as shown here:

Lua 5.0  Copyright (C) 1994-2003 Tecgraf, PUC-Rio
> = gcinfo()
18      37
> a,b = {},{}
> a.b, b.a = b, a                    -- mutual reference
> a.string = string.rep('a', 100000)
> = gcinfo()
165     330
> b.string = string.rep('a', 100000) -- aha no duplicated strings!
> = gcinfo()
165     330
> b.string = string.rep('a', 100001)
> = gcinfo()
263     526
> collectgarbage()
> = gcinfo()
239     477
> a,b = nil,nil       -- we now have 2 unreachable tables
> = gcinfo()          -- not deleted yet
239     477
> collectgarbage()
> = gcinfo()          -- collected the island
31      61