Message 169409 - Python tracker

Message169409

Author	pitrou
Recipients	Arfrever, christian.heimes, georg.brandl, loewis, mark.dickinson, meador.inge, ncoghlan, pitrou, skrah, vstinner
Date	2012-08-29.19:06:28
SpamBayes Score	-1.0
Marked as misclassified	Yes
Message-id	<1346266979.3344.1.camel@localhost.localdomain>
In-reply-to	<503E667B.8070804@v.loewis.de>

Content
> Am 29.08.12 20:01, schrieb Antoine Pitrou: > >> I think the proper solution is to make memoryview objects unhashable. > > > > Disagreed. If memoryviews are to be bytes-like objects they should be > > hashable (at least when readonly). > > So what specific hash algorithm do you propose? The current algorithm works well in conjunction with bytes objects. > My claim is that any hash definition for memoryviews will have a > fundamental flaw, failing to provide the basic property > that A==B must imply hash(A)==hash(B), making it actually work > incorrectly Why is there such a fundamental flaw?

Content

> Am 29.08.12 20:01, schrieb Antoine Pitrou:
> >> I think the proper solution is to make memoryview objects unhashable.
> >
> > Disagreed. If memoryviews are to be bytes-like objects they should be
> > hashable (at least when readonly).
> 
> So what specific hash algorithm do you propose?

The current algorithm works well in conjunction with bytes objects.

> My claim is that any hash definition for memoryviews will have a
> *fundamental* flaw, failing to provide the basic property
> that A==B must imply hash(A)==hash(B), making it actually work
> incorrectly

Why is there such a fundamental flaw?

History
Date	User	Action	Args
2012-08-29 19:06:29	pitrou	set	recipients: + pitrou, loewis, georg.brandl, mark.dickinson, ncoghlan, vstinner, christian.heimes, Arfrever, skrah, meador.inge
2012-08-29 19:06:28	pitrou	link	issue15814 messages
2012-08-29 19:06:28	pitrou	create