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Re: XML literals

From: Graham Klyne <gk@ninebynine.org>
Date: Thu, 14 Aug 2003 08:05:42 +0100
Message-Id: <5.1.0.14.2.20030814080218.00b7c200@127.0.0.1>
To: "Jeremy Carroll" <jjc@hplb.hpl.hp.com>, <w3c-rdfcore-wg@w3.org>

Seems generally OK to me.  A couple of thoughts for consideration:

(a) should something be said about equality of "XML values"?  (e.g. are 
equal when their corresponding lexical forms are equal).

(b) if concerned with the word "corresponding", maybe change:
[[
   + correspond  under [UTF-8] encoding to exclusive Canonical
     XML (with comments, with empty InclusiveNamespaces
     PrefixList ) [XML-XC14N];
   + when embedded between an arbitrary XML start tag and an end tag
     correspond to a document conforming to XML Namespaces [XML-NS]
]]
to
[[
   + application of UTF-8 encoding [UTF-8] yields exclusive Canonical
     XML (with comments, with empty InclusiveNamespaces
     PrefixList ) [XML-XC14N];
   + when embedded between an arbitrary XML start tag and an end tag
     yields a document conforming to XML Namespaces [XML-NS]
]]

#g
--

At 17:43 13/08/03 +0200, Jeremy Carroll wrote:


>The main planks of Pat's text from
>
>http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2003Jul/0452
>
>seemed to get support at the RDF Core WG telecon on Friday, I was actioned
>to move the conversation forward, and ensure that Martin and I18N were in on
>it.
>My understanding is that the main goal was to avoid any possibility of
>confusing XMLLiteral with xsd:hexBinary as in Martin's test case.
>
>I also am trying to adequately address Patrick's concerns while changing
>Pat's text as little as possible.
>
>Brian used the term "XML fragment" at the telecon, I am however sticking
>with Pat's "XML value" because of the existence of
>
>http://www.w3.org/TR/xml-fragment
>
>which makes Brian's preferred term misleading.
>I would be happy to consider other words for XML value.
>
>For completeness I also include stuff on the lexical space, since there was
>some concern that the wording is not about Unicde strings ... and the word
>"corresponding" ...
>
>I have numbered the notes for the sake of this e-mail, further discussion
>below.
>
>Patrick - please indicate whether the last two notes (2,3) adequately
>address your concerns. (3) ended up perhaps more geared towards some of
>Martin's concerns.
>
>I ended up unclear as to whether note 2 was wanted by the WG or not.
>
>[[
>The lexical space
>   is the set of all strings which:
>   + are well-balanced, self-contained XML data [XML];
>   + correspond  under [UTF-8] encoding to exclusive Canonical
>     XML (with comments, with empty InclusiveNamespaces
>     PrefixList ) [XML-XC14N];
>   + when embedded between an arbitrary XML start tag and an end tag
>     correspond to a document conforming to XML Namespaces [XML-NS]
>
>
>The value space is a set of entities, called XML values, which is:
>   + disjoint from the lexical space
>   + disjoint from the value space of any XML schema datatype [XML-SCHEMA2]
>   + disjoint from the set of Unicode character strings [Unicode]
>   + in 1:1 correspondence with the lexical space.
>
>
>
>The lexical-to-value mapping
>    is a one-one mapping from the lexical space onto the value space,
>    i.e. it is both injective and surjective.
>
>
>
>Note (1): Not all lexical forms of this datatype are compliant with XML 1.1
>[XML 1.1]. If compliance with XML 1.1 is desired, then only those that are
>fully normalized according to XML 1.1 should be used.
>
>Note (2): XML values can be thought of as the [XML Infoset] or
>the [XPath] nodeset corresponding to the lexical form, with an appropriate
>equality function.
>
>Note (3): RDF applications may use additional equivalence relations, such as
>that which relates an xsd:string with an rdf:XMLLiteral corresponding to a
>single text node of the same string.
>
>]]
>
>
>I seem to recall concern about putting too much into notes. Either the stuff
>is sufficiently important to go into the design, or it isn't.
>
>This may be sufficient to kill notes (2) and (3). I am reluctant to drop
>note (1) since the RDF specs have largely followed charmod on NFC which puts
>us into a somewhat anomolous position between XML 1.0 and XML 1.1 ...
>
>If the notes add clarity then it is probably best to keep them.

------------
Graham Klyne          _________
GK@ninebynine.org  ___|_o_o_o_|_
                    \____________/
(nb Helva)       ~~~~~~~~~~~~~~~~~~   @Hampton Court, River Thames
Received on Thursday, 14 August 2003 08:59:54 EDT

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