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ACTION-93: suggest a resolution to IRI support

From: Philippe Le Hegaret <plh@w3.org>
Date: Thu, 28 Jun 2007 16:07:14 +0000
To: public-sml@w3.org
Message-Id: <1183046834.4182.168.camel@localhost>

This is a follow up to

One of the questions was how easy it is to switch from URI to IRI.

The XML Schema type anyURI does provide support for IRI, so we will
still use xs:anyURI in the XML Schema.

WSDL 2.0, who went through the same questions we're now having [1],
incorporated this section in their document:
1.4.3 XML Schema anyURI

This specification uses the XML Schema type xs:anyURI (see [XML Schema:
Datatypes]). It is defined so that xs:anyURI values are essentially IRIs
(see [IETF RFC 3987]). The conversion from xs:anyURI values to an actual
URI is via an escaping procedure defined by (see [XLink 1.0]), which is
identical in most respects to IRI Section 3.1 (see [IETF RFC 3987]).

For interoperability, WSDL authors are advised to avoid the US-ASCII
characters: "<", ">", '"', space, "{", "}", "|", "\", "^", and "`",
which are allowed by the xs:anyURI type, but disallowed in IRIs.

While there is agreement on what the escaping procedure should be, there
is still ongoing discussion between the XML Core and I18n Core Working
Group [2] on where the final definition of the procedure should go;
XLink 1.0 being not perceived at the best place. If we were going to
adopt the text from the WSDL 2.0 specification, we would need to have a
normative reference to XLink 1.0. The procedure isn't new and has been
in effect in "XML system identifier, XLink href and several other

My proposed resolution is to adopt the wording of the WSDL 2.0
Recommendation in SML and SML-IF (with a clarification that the
procecure is found in section 5.4 of XLink), stay out of the discussion
between XML Core and I18n Core, use the term "IRI" instead of "URI" in
the specification, and make no change to the XML Schema.

We already have a separate issue on renaming the uri element.


[1] http://lists.w3.org/Archives/Public/www-ws-desc/2005Apr/0044.html
[2] http://lists.w3.org/Archives/Public/public-iri/2007May/0000.html
Received on Thursday, 28 June 2007 16:07:36 UTC

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