[jdom-interest] Inconsistancy in Namespace.hashCode().

[Brett McLaughlin]

I agree with Elliotte's analysis.

-Brett

> -----Original Message-----
> From: jdom-interest-admin at jdom.org
> [mailto:jdom-interest-admin at jdom.org]On Behalf Of Elliotte Rusty Harold
> Sent: Saturday, March 03, 2001 9:34 AM
> To: Jason Hunter; Steven D. Keens
> Cc: jdom-interest
> Subject: Re: [jdom-interest] Inconsistancy in Namespace.hashCode().
>
>
> At 2:45 PM -0800 2/28/01, Jason Hunter wrote:
>
> >Good eye.  I've changed the documentation on my local copy to be:
> >
> >      *  This returns a probably unique hash code for the
> ><code>Namespace</code>.
> >      *  If two namespaces have the same URI but different prefixes, they
> >may
> >      *  have a different hash code.
> >
> >This correctly defines the behavior, and I think the existing behavior
> >is correct.  Anyone (Elliotte esp) have concerns?
> >
>
> Yes, I disagree. I'm not sure when the mistake got in, but the
> comment is correct (i.e. it describes the right behavior) and the
> current code is wrong. Two namespaces are equal if their URIs are
> equal. The prefix should not be considered when testing for equality.
>
> I suppose you can argue that two Namespace objects are not equal if
> they describe different prefixes. Maybe that makes sense, but it
> makes me deeply uncomfortable.
>
> I guess the question comes down to what the use case for comparing
> namespaces is. I would expect that the equals method would let us
> take two set elements with possibly different prefixes, possibly one
> in a default namespace, and determine whether or not they have the
> same type; e.g. are both MathML set elements or is one a MathML set
> element and one an SVG set element? This only works if we compare
> based on URI and not prefix.
> --
>
> +-----------------------+------------------------+-------------------+
> | Elliotte Rusty Harold | elharo at metalab.unc.edu | Writer/Programmer |
> +-----------------------+------------------------+-------------------+
> |                  The XML Bible (IDG Books, 1999)                   |
> |              http://metalab.unc.edu/xml/books/bible/               |
> |   http://www.amazon.com/exec/obidos/ISBN=0764532367/cafeaulaitA/   |
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