order independent hash?

[Tim Chase]

On 12/04/11 08:08, Chris Angelico wrote:
> 2011/12/5 Hrvoje Niksic<hniksic at xemacs.org>:
>> If a Python
>> implementation tried to implement dict as a tree, instances of classes
>> that define only __eq__ and __hash__ would not be correctly inserted in
>> such a dict.
>
> Couldn't you just make a tree of hash values? Okay, that's probably
> not the most useful way to do things, but technically it'd comply with
> the spec.

 From an interface perspective, I suppose it would work.  However 
one of the main computer-science reasons for addressing by a hash 
is to get O(1) access to items (modulo pessimal hash 
structures/algorithms which can approach O(N) if everything 
hashes to the same value/bucket), rather than the O(logN) time 
you'd get from a tree. So folks reaching for a hash/map might be 
surprised if performance degraded with the size of the contents.

-tkc