On Thu, 2005-12-29 at 17:17 +0100, Fredrik Lundh wrote: > Noam Raphael wrote: > > > I'm not saying that practically it must be used - I'm just saying that > > it can't be called a heuristic, and that it doesn't involve any "fancy > > overkill size hinting or history tracking". It actually means > > something like this: > > 1. If you want to insert and the table is full, resize the table to > > twice the current size. > > 2. If you delete and the number of elements turns out to be less than > > a quarter of the size of the table, resize the table to half of the > > current size. > > sure sounds like a heuristic algorithm to me... (as in "not guaranteed to > be optimal under all circumstances, even if it's probably quite good in all > practical cases") > > </F>
My problem with this heuristic is it doesn't work well for the probably-fairly-common use-case of; fill it, empty it, fill it, empty it, fill it...etc. As Guido pointed out, if you do have a use-case where a container gets very big, then shrinks and doesn't grow again, you can manually cleanup by creating a new container and del'ing the old one. If the implementation is changed to use this heuristic, there is no simple way to avoid the re-allocs for this use-case... (don't empty, but fill with None... ugh!). My gut feeling is this heuristic will cause more pain than it would gain... -- Donovan Baarda <[EMAIL PROTECTED]> http://minkirri.apana.org.au/~abo/ _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
