From: James Coglan <jcoglan@...>
Date: 2009-07-23T01:47:13+09:00
Subject: Re: Incorrect -0.0.hash - Ruby bug.

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2009/7/22 John W Higgins <wishdev@gmail.com>

> Morning Thomas,
>
> On Wed, Jul 22, 2009 at 9:24 AM, Thomas B. <tpreal@gmail.com> wrote:
>
> > Hello. I just found a bug in Ruby, version 1.9.1p0, Windows.
> >
> > In the rdoc to Object#hash we read
> > (http://ruby-doc.org/core/classes/Object.html#M000337):
> >
> > "This function must have the property that a.eql?(b) implies a.hash ==
> > b.hash."
> >
>
> Actually Float overrides both #eql? and #hash so the contract is not
> applicable inside that class. Is that the best option in the world?? -
> probably not - but that would make it a non bug in theory.


Is there a reason for this? Perhaps the inexact nature of Floats means you
ought not to use them as hash keys?

--
James Coglan
http://jcoglan.com

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