> In both cases, __hash__ is not idempotent, and is thus an abomination.
Why do you say it's not idempotent? The first time you call it, either it works or it doesn't. If it doesn't work, then you shouldn't have called it in the first place. If it does work, all subsequent calls will return the same result. > Case > 1 is a perverse programmer -- well known to be capable of abominations. What is perverse about case 1? I'm not being disingenuous here; I really don't know. I am assuming, of course, that the object in question never changes the value of its component once constructed. > Case 2 sounds like a made-up example... can you think of anything real > which behaves this way? (For instance: the file type doesn't even though > it might, and I presume this is intentional.) I'll admit it's a little more far-fetched; that's why it's second on the list. But hypothetical or not, I think it serves to underscore the original point, which is that it is entirely plausible for objects to have properties that trigger side effects when used, and for which it may be useful to have a way of asking about their presence without triggering the side effects. _______________________________________________ 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
