Collin Winter wrote: > On 7/25/06, Andrew Koenig <[EMAIL PROTECTED]> wrote: >>> With your CD example, you need an external resource (the CD itself) in >>> order to calculate the hash - in that case, you can't safely defer >>> the hash calculation until the first time you know you need it, >>> since you don't know whether or not you'll have access to the >>> physical CD at that point. >> OK. Then instead of a CD, use a (read-only) disk file. The example is >> still valid in that case, and avoids the extraneous matter of operator >> intervention. > > Oh, please. No-one's arguing that hashes MUST be fast to compute; it's > just a good rule of thumb. There will of course be exceptional cases, > like the contrived examples you've come up with, but they're just > that: exceptional. If you find yourself writing classes that must hash > a large on-disk file or CD or whatever else, you can add custom tests > for hashability yourself. There's no need to clutter the language to > cater to every odd corner case someone digs up.
Very well said and I couldn't agree more. +1 for not adding hashable() to the language. Stefan _______________________________________________ Python-3000 mailing list Python-3000@python.org http://mail.python.org/mailman/listinfo/python-3000 Unsubscribe: http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
