]> On Wednesday, November 12, 2003, at 10:13 AM, Aleksey Nogin wrote: > When trying to switch from 3.06 to 3.07+2 I've noticed the following > difference in how the Weak module works: [ In 3.06, an empty list [] does not disappear from a weak array; in 3.07+2 it disappears immediately ] > Basically, in 3.07+2, the empty list disappears from the weak array as > soon as it is added into it. Is this a bug or a feature? Feature. > The old behavior is useful because it allows to assume that while a > value is referenced somewhere, Weak.get will always return Some. This > allowed using Weak.get as an indicator of whether it was OK to discard > some "helper" data (which should be only discarded after the primary > data is no longer in use). Yes, but. In 3.06, [] will never be removed from the weak array, and you will keep your helper data forever. The source your the problem is that [] is not allocated in the heap. It is represented by an integer value. Hence, there is no sharing between various occurrences of [] in your data and the notion of a weak pointer to [] does not make sense. If you really want to make sure that you are manipulating pointers, you should use a record or a list ref. -- Damien ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners