pickle complexity limit?

[Paul Rubin]

martin at v.loewis.de (Martin v. Löwis) writes:
> > I wonder if it's feasible to write a pickler as a C extension that
> > works something like a pointer-reversing garbage collector,
> > eliminating the need for recursion and still not needing any extra
> > storage in the objects.
> 
> You definitely will need storage, to remember the objects you have to
> come back to; you won't necessarily need storage *in the objects*.

No.  I'm talking about a crazy hack that was used in some old-time
Lisp systems.  The idea is to temporarily reverse the pointers that
already exist in the objects to track what's been GC'd, so you don't
need more than a constant amount of additional storage.  Google for
"Deutsch Schorr Waite garbage collection" or look in Knuth vol 1 for
more info.