From: Robert Klemme <shortcutter@...>
Date: 2010-11-07T20:55:16+09:00
Subject: Re: random bug in the & (set intersection) operator in Arrays

On 07.11.2010 12:06, Jean-Christophe Le Lann wrote:
> Le 07/11/2010 11:40, Robert Klemme a écrit :

>>> I think I have discovered a random bug in the&   (set intersection)
>>> operator in Arrays.
>>
>> Well, Set's implementation and Array's are different.  I believe Array
>> does not use #hash while Set does to efficiently find equivalent
>> instances.  Can you show the code for Say#eql?, Say#hash and Say#==
>> (same for all other classes whose instances are put into your Arrays)?
>> I am not convinced yet that you found a bug.

> I have no such methods. I simply though that the object IDs would be
> used for the intersection of the two arrays. Am I wrong ? Thx for your
> time and explanations !

As long as you define equivalence solely based on object identity you do 
not need specific implementations of #hash and #eql?.  You can find a 
bit of explanation here

http://blog.rubybestpractices.com/posts/rklemme/018-Complete_Class.html

Still it would be good if you could provide a simple test case that 
reproduces the problem.  You need that for a bug report anyway.

Kind regards

	robert

-- 
remember.guy do |as, often| as.you_can - without end
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