From: George Ogata <g_ogata@...>
Date: 2004-08-06T10:41:27+09:00
Subject: Re: Sets are not extensional

Kristof Bastiaensen <kristof@vleeuwen.org> writes:

> {}.hash == {}.hash
> => false
> Set[].hash == Set[].hash
> => false
> [].hash == [].hash
> => true
>
> I have no idea for the reason why different hashes have different
> hashvalues, while different arrays may get the same value (based on the
> contents of the array).

This seems like a blatant bug to me.  `a.eql? b' must imply `a.hash ==
b.hash', yet:

irb(main):001:0> a = {}; b = {}
=> {}
irb(main):002:0> a.eql?(b)
=> true
irb(main):003:0> a.hash == b.hash
=> false