Am 04.06.2010 20:26, schrieb Martin Buchholz:
Aside from the fact that it would be a hugely incompatible change
to change the hashing/equality algorithm now,
it is quite a religious argument about which is the Right Thing to do.
In most cases we have freedom of religion as we have HashMap and
IdentityHashMap.
There is one exception (maybe more?) for x[] as key.
Both compare arrays on identity level, and unfortunately it's almost
impossible to change this due to incompatibility.
Bug ID 6812862 would provide this religion freedom as a side effect. So
I again don't understand the resistance against it.
Here's some religion/philosophy for you:
http://home.pipeline.com/~hbaker1/ObjectIdentity.html
Thanks for this interesting historical pre-Java paper.
-Ulf
There are some existing collections, e.g. BlockingQueues,
that use identity comparison instead of content comparison.
Martin
On Fri, Jun 4, 2010 at 08:49, Ulf Zibis<ulf.zi...@gmx.de> wrote:
Otherwise e.g. int[] as key for HashSet/Map doesn't make any sense.
I use a class where the content of an int[] defines the uniqueness or there
instances.
Before I create a new instance, I have to check if there is just one for the
same int[] content.
Using the current HashSet/Map implementation does not serve this need.
It seems, that I should first instantiate a temporary object containing the
int[], hash it in the set/map, and later throw it away. :-(
Maybe another reason for solving
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6812862
-Ulf
