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Re: p:input doppelgangers

From: Alessandro Vernet <avernet@orbeon.com>
Date: Thu, 5 Jul 2007 10:33:28 -0700
Message-ID: <4828ceec0707051033ma4047edj66d150af5a84173b@mail.gmail.com>
To: public-xml-processing-model-wg <public-xml-processing-model-wg@w3.org>

On 7/5/07, Norman Walsh <ndw@nwalsh.com> wrote:
> It seems to me that requiring a context for an expression like "$foo"
> is even more problematic for users than requiring implementors to
> deal with not having a context in that case.

I agree, but my point is that:

1) The XPath specification requires a context node for an expression
to be evaluated. And this even if the expression does not use the
context node. If you have no context node, you can't evaluate the
expression.

2) Pragmatically, some implementations (e.g. Saxon) do require a
context node to evaluate an XPath expression. You could decide to pass
some type of "dummy" context node if you don't have a "real" context
node, but if the expression uses that node, you will have some
unexpected result, not an error. I don't think we want that to happen.

With this in mind, p:empty should not be allowed.

Alex
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Received on Thursday, 5 July 2007 17:33:41 GMT

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