Guido van Rossum wrote:
For strings at least, perhaps it is time to bite the bullet and include weak reference support directly. Weak reference support ups the per string memory overhead from five words (ob_type, ob_refcnt, ob_size, ob_shash, ob_sstate) to six. The whole concept of weak dictionaries is much more useful when strings can be used as keys and/or values.
Hmm... it is a high price to pay to add another word (*and* some extra code at dealloc time!) to every string object when very few apps need them and strings are about the most common data type. And since they're immutable, what's the point of having weak refs to strings in the first place? (Note that the original poster asked about *subclasses* of strings.)
Same here. I wouldnot vote to make strings or tuples or any other tiny type weak-reffed in the first place. Instead I would add the possible support to derived types, via the __slot__ mechanism for instance. There is a little coding necessary to make the generic code handle the case of var-sized objects, but this is doable and not very complicated. This may be really needed or not. if we can create the rule "every derived type *can* have weak-refs", this is simpler to memorize than "well, most can, some cannot". cheers -- chris -- Christian Tismer :^) <mailto:tismer@stackless.com> Mission Impossible 5oftware : Have a break! Take a ride on Python's Johannes-Niemeyer-Weg 9a : *Starship* http://starship.python.net/ 14109 Berlin : PGP key -> http://wwwkeys.pgp.net/ work +49 30 89 09 53 34 home +49 30 802 86 56 mobile +49 173 24 18 776 PGP 0x57F3BF04 9064 F4E1 D754 C2FF 1619 305B C09C 5A3B 57F3 BF04 whom do you want to sponsor today? http://www.stackless.com/