Re: [xml-dev] Escaping and Encoding of reserved URI characters inXPointe

[Liam R E Quin <liam@w3.org>]

On Tue, 2013-01-22 at 17:33 -0800, David Sheets wrote:
> Maybe someone on this list can clarify the question below?
> 
> Sent <http://lists.w3.org/Archives/Public/www-xml-linking-comments/2013JanMar/0000.html>
> 5 days ago to <mailto:www-xml-linking-comments@w3.org> without
> response:

Note, the XML Core Working Group only meets every other week.

> 
> Reading <http://www.w3.org/TR/xptr-framework/#escaping>, I am left
> with the impression that the number sign (#), percent sign (%), and
> square bracket characters ('[', ']') do NOT need to be escaped in a
> fragment identifier subscribing to the XPointer Framework.

This would not be a correct impression.
> 
> Have I understood this correctly? Does XPointer Framework actually
> recommend a fragment identifier syntax that contradicts RFC 2396 and
> its revision RFC 3986?

No. See the examples in 4.2 Examples of Escaping. It depends on the
context in which the XPointer occurs, though. In an XML document,
#xpointer(id('r&#xE9;sum&#xE9;'))
is given as an example, but the #-signs here would be treated as part of
numeric character references by the XML processor before the link was
actually used.

The phrase, "except for the number sign (#) and percent sign (%) and the
square bracket characters re-allowed in [RFC 2732]." could have been
written, "except for the number sign (#) and percent sign (%), and for
the square bracket characters re-allowed in [RFC 2732]." and is in the
paragraph about turning an IRI into a URI. You don't escape the # in an
IRI when turning it to a URI because it marks the start of the fragment
identifier. Other #-signs were already escaped when the IRI was
constructed.

Yes, escaping is a huge mess in XPointer, at least in part becaue IRI
syntax is a mess.

Liam

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Liam Quin - XML Activity Lead, W3C, http://www.w3.org/People/Quin/
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