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<p><a href="http://www.w3.org/"><img src=
"http://www.w3.org/Icons/w3c_home" alt="W3C" height="48" width=
"72" /></a></p>
<h1><a name="title" id="title"></a>XQuery 3.0 Requirements</h1>
<h2><a name="w3c-doctype" id="w3c-doctype"></a>W3C Working Draft 16
September 2010</h2>
<dl>
<dt>This version:</dt>
<dd><a href=
"http://www.w3.org/TR/2010/WD-xquery-30-requirements-20100916/">http://www.w3.org/TR/2010/WD-xquery-30-requirements-20100916/</a></dd>
<dt>Latest version:</dt>
<dd><a href=
"http://www.w3.org/TR/xquery-30-requirements/">http://www.w3.org/TR/xquery-30-requirements/</a></dd>
<dt>Previous version:</dt>
<dd><a href=
"http://www.w3.org/TR/2007/WD-xquery-11-requirements-20070323">http://www.w3.org/TR/2007/WD-xquery-11-requirements-20070323</a></dd>
<dt>Editors:</dt>
<dd>Daniel Engovatov, BEA Systems <a href=
"mailto:dengovatov@bea.com"><dengovatov@bea.com></a></dd>
<dd>Jonathan Robie, Red Hat</dd>
</dl>
<p class="copyright"><a href=
"http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> © 2010 <a href="http://www.w3.org/"><acronym title="World Wide Web Consortium">W3C</acronym></a><sup>®</sup>
(<a href="http://www.csail.mit.edu/"><acronym title=
"Massachusetts Institute of Technology">MIT</acronym></a>, <a href=
"http://www.ercim.eu/"><acronym title=
"European Research Consortium for Informatics and Mathematics">ERCIM</acronym></a>,
<a href="http://www.keio.ac.jp/">Keio</a>), All Rights Reserved.
W3C <a href=
"http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>,
<a href=
"http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a>
and <a href=
"http://www.w3.org/Consortium/Legal/copyright-documents">document
use</a> rules apply.</p>
</div>
<hr />
<div>
<h2><a name="abstract" id="abstract"></a>Abstract</h2>
<p>This document specifies goals and requirements for XML Query
(XQuery) 3.0.</p>
</div>
<div>
<h2><a name="status" id="status"></a>Status of this Document</h2>
<p><em>This section describes the status of this document at the
time of its publication. Other documents may supersede this
document. A list of current W3C publications and the latest
revision of this technical report can be found in the <a href=
"http://www.w3.org/TR/">W3C technical reports index</a> at
http://www.w3.org/TR/.</em></p>
<p>This is a <a href=
"http://www.w3.org/2005/10/Process-20051014/tr.html#maturity-levels">
Working Draft</a> as described in the <a href=
"http://www.w3.org/2005/10/Process-20051014/tr.html">Process
Document</a>. It has been developed by the W3C <a href=
"http://www.w3.org/XML/Query/">XML Query Working Group</a>, which
is part of the <a href="http://www.w3.org/XML/Activity">XML
Activity</a>. The Working Group expects to eventually publish this
document as a Working Group Note.</p>
<p>These Requirements identify extensions to the <a href=
"http://www.w3.org/TR/xquery/">XQuery 1.0 Recommendation</a>,
published 23 January 2007, that have been requested by WG
participants and by reviewers who do not participate in the W3C
activities. The XML Query WG has reviewed these requirements
extensively and has reached a very high level of agreement (but not
necessarily unanimity) on the desirability of each of them.</p>
<p>Please report errors in this document using W3C's <a href=
"http://www.w3.org/Bugs/Public/">public Bugzilla system</a>
(instructions can be found at <a href=
"http://www.w3.org/XML/2005/04/qt-bugzilla">http://www.w3.org/XML/2005/04/qt-bugzilla</a>).
If access to that system is not feasible, you may send your
comments to the W3C XSLT/XPath/XQuery public comments mailing list,
<a href=
"mailto:public-qt-comments@w3.org">public-qt-comments@w3.org</a>.
It will be very helpful if you include the string “[XQuery11Req]”
in the subject line of your report, whether made in Bugzilla or in
email. Please use multiple Bugzilla entries (or, if necessary,
multiple email messages) if you have more than one comment to make.
Archives of the comments and responses are available at <a href=
"http://lists.w3.org/Archives/Public/public-qt-comments/">http://lists.w3.org/Archives/Public/public-qt-comments/</a>.</p>
<p>Publication as a Working Draft does not imply endorsement by the
W3C Membership. This is a draft document and may be updated,
replaced or obsoleted by other documents at any time. It is
inappropriate to cite this document as other than work in
progress.</p>
<p>This document was produced by a group operating under the
<a href="http://www.w3.org/Consortium/Patent-Policy-20040205/">5
February 2004 W3C Patent Policy</a>. W3C maintains a <a href=
"http://www.w3.org/2004/01/pp-impl/18797/status#disclosures">public
list of any patent disclosures</a> made in connection with the
deliverables of the group; that page also includes instructions for
disclosing a patent. An individual who has actual knowledge of a
patent which the individual believes contains <a href=
"http://www.w3.org/Consortium/Patent-Policy-20040205/#def-essential">
Essential Claim(s)</a> must disclose the information in accordance
with <a href=
"http://www.w3.org/Consortium/Patent-Policy-20040205/#sec-Disclosure">
section 6 of the W3C Patent Policy</a>.</p>
</div>
<div class="toc">
<h2><a name="contents" id="contents"></a>Table of Contents</h2>
<p class="toc">1 <a href="#goals">Goals</a><br />
2 <a href="#Requirements">Requirements</a><br />
    2.1 <a href=
"#terminology">Terminology</a><br />
    2.2 <a href="#general-requirements">General
Requirements</a><br />
        2.2.1 <a href=
"#backward-compatibility">Backward compatibility</a><br />
        2.2.2 <a href=
"#extension-compatibility">Extension compatibility</a><br />
    2.3 <a href="#xml-query-functionality">XML
Query Functionality</a><br />
        2.3.1 <a href=
"#d2e301">Value-based grouping</a><br />
        2.3.2 <a href=
"#error-processing-and-recovery">Error processing and
recovery</a><br />
        2.3.3 <a href=
"#numeric-formatting">Numeric formatting</a><br />
        2.3.4 <a href=
"#date-formatting">Date formatting</a><br />
        2.3.5 <a href=
"#default-values-for-external-variables">Default values for
external variables</a><br />
        2.3.6 <a href=
"#non-deterministic-external-functions">Non-deterministic external
functions</a><br />
        2.3.7 <a href=
"#positional-grouping">Positional grouping</a><br />
        2.3.8 <a href=
"#windowing">Windowing</a><br />
        2.3.9 <a href=
"#output-numbering">Output numbering</a><br />
        2.3.10 <a href=
"#dynamic-creation-of-namespace-bindings">Dynamic creation of
namespace bindings</a><br />
        2.3.11 <a href=
"#declaration-of-serialization-parameters">Declaration of
serialization parameters</a><br />
        2.3.12 <a href=
"#node-references">Node references</a><br />
        2.3.13 <a href=
"#outer-for">Outer for</a><br />
        2.3.14 <a href=
"#type-declaration-for-context-item">Type declaration for context
item</a><br />
        2.3.15 <a href=
"#support-for-new-data-types">Support for new data types</a><br />
        2.3.16 <a href=
"#higher-order-functions">Higher order functions</a><br />
        2.3.17 <a href=
"#conditional-constructors">Conditional constructors</a><br />
        2.3.18 <a href=
"#validation">Validation</a><br />
        2.3.19 <a href=
"#type-expressions">Type expressions</a><br />
        2.3.20 <a href=
"#module-composition-restrictions">Module composition
restrictions</a><br />
        2.3.21 <a href=
"#invocation-of-external-functionality">Invocation of external
functionality</a><br />
        2.3.22 <a href=
"#static-typing-extensions">Static typing extensions</a><br />
3 <a href="#references">References</a><br />
    3.1 <a href=
"#normative-references">Normative</a><br />
    3.2 <a href=
"#non-normative-references">Non-normative</a><br /></p>
</div>
<hr />
<div class="body">
<div class="div1">
<h2><a name="goals" id="goals"></a>1 Goals</h2>
<p>The goal of XML Query 3.0 is to extend XML Query 1.0 with
additional functionality in response to requests from users and
implementors.</p>
<p>Satisfying these goals may require changes to the set of seven
documents that have progressed to Recommendation together (Data
Model, Functions and Operators, Serialization, XPath 2.0, XQuery
1.0, XQueryX, and XSLT 2.0).</p>
</div>
<div class="div1">
<h2><a name="Requirements" id="Requirements"></a>2
Requirements</h2>
<div class="div2">
<h3><a name="terminology" id="terminology"></a>2.1 Terminology</h3>
<p>The following keywords are used throughout the document to
specify the extent to which an item is a requirement for the work
of the XML Query Working Group:</p>
<dl>
<dt class="label"><a name="terminology-must" id=
"terminology-must"></a>MUST</dt>
<dd>
<p>The item is an absolute requirement.</p>
</dd>
<dt class="label"><a name="terminology-should" id=
"terminology-should"></a>SHOULD</dt>
<dd>
<p>There may exist valid reasons not to treat this item as a
requirement, but the full implications should be understood and the
case carefully weighed before discarding this item.</p>
</dd>
<dt class="label"><a name="terminology-may" id=
"terminology-may"></a>MAY</dt>
<dd>
<p>An item deserves attention, but further study is needed to
determine whether the item should be treated as a requirement.</p>
</dd>
</dl>
<p>When the words <a href="#terminology-must">MUST</a>, <a href=
"#terminology-should">SHOULD</a>, or <a href=
"#terminology-may">MAY</a> are used in this technical sense
[<a href="http://www.ietf.org/rfc/rfc2119.txt">IETF RFC 2119</a>],
they occur as a hyperlink to these definitions. These words will
also be used with their conventional English meaning, in which case
there is no hyperlink. For instance, the phrase "the full
implications should be understood" uses the word "should" in its
conventional English sense, and therefore occurs without the
hyperlink.</p>
<p id="req-status">Each requirement also includes a status section,
indicating its current situation in the XQuery/XPath/XSLT family of
specifications. Three status levels are used:</p>
<dl>
<dt class="label">"Green" status</dt>
<dd>
<p><img src="http://www.w3.org/Icons/green-ball.gif" alt=
"green status" /> This indicates that the requirement, according to
its original formulation, has been completely met. Optional
clarifying text may follow.</p>
</dd>
<dt class="label">"Yellow" status</dt>
<dd>
<p><img src="http://www.w3.org/Icons/yellow-ball.gif" alt=
"yellow status" /> This indicates that the requirement has been
partially met according to its original formulation. When this
happens, explanatory text is provided to better clarify the current
scope of the requirement.</p>
</dd>
<dt class="label">"Red" status</dt>
<dd>
<p><img src="http://www.w3.org/Icons/red-ball.gif" alt=
"red status" /> This indicates that the requirement, according to
its original formulation, has not been met. If this is the case,
explanatory text is provided.</p>
</dd>
</dl>
</div>
<div class="div2">
<h3><a name="general-requirements" id=
"general-requirements"></a>2.2 General Requirements</h3>
<div class="div3">
<h4><a name="backward-compatibility" id=
"backward-compatibility"></a>2.2.1 Backward compatibility</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-must">MUST</a> be backward
compatible.</p>
<p>Every valid XQuery 1.0 expression <a href=
"#terminology-must">MUST</a> be valid in XQuery 3.0 and it <a href=
"#terminology-must">MUST</a> evaluate to the same result.</p>
<p><img src="http://www.w3.org/Icons/green-ball.gif" alt=
"green status" /> <em>Status:</em> this requirement has been
met.</p>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="extension-compatibility" id=
"extension-compatibility"></a>2.2.2 Extension compatibility</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-must">MUST</a> be compatible
with XQuery 1.0 extensions developed by the <a href=
"http://www.w3.org/XML/Query/">XML Query Working Group</a>,
including <a href="#UpdateRequirements">XQuery Update Facility</a>
and <a href="#FullTextRequirements">XQuery 1.0 and XPath 2.0
Full-Text</a>.</p>
<p><img src="http://www.w3.org/Icons/green-ball.gif" alt=
"green status" /> <em>Status:</em> this requirement has been
met.</p>
</dd>
</dl>
</div>
</div>
<div class="div2">
<h3><a name="xml-query-functionality" id=
"xml-query-functionality"></a>2.3 XML Query Functionality</h3>
<div class="div3">
<h4><a name="d2e301" id="d2e301"></a>2.3.1 Value-based
grouping</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-must">MUST</a> include a
language facility to specify value-based grouping.</p>
<p><img src="http://www.w3.org/Icons/green-ball.gif" alt=
"green status" /> <em>Status:</em> this requirement has been
met.</p>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="error-processing-and-recovery" id=
"error-processing-and-recovery"></a>2.3.2 Error processing and
recovery</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-must">MUST</a> provide a
mechanism to process errors raised by an expression and to return
an alternative value.</p>
<p>This <a href="#terminology-may">MAY</a> be implemented by
introducing a <em>try-catch</em> expression.</p>
<p><img src="http://www.w3.org/Icons/green-ball.gif" alt=
"green status" /> <em>Status:</em> this requirement has been
met.</p>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="numeric-formatting" id="numeric-formatting"></a>2.3.3
Numeric formatting</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-must">MUST</a> include
additional library functions or an equivalent mechanism to perform
formatting of numeric values.</p>
<p>It <a href="#terminology-should">SHOULD</a> be similar to the
functionality provided in <a href="#XSLT20">XSLT 2.0</a>, such as
by function <code>format-number()</code>.</p>
<p><img src="http://www.w3.org/Icons/green-ball.gif" alt=
"green status" /> <em>Status:</em> this requirement has been
met.</p>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="date-formatting" id="date-formatting"></a>2.3.4 Date
formatting</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-must">MUST</a> include
additional library functions or an equivalent mechanism to perform
formatting of date and time values.</p>
<p>It <a href="#terminology-should">SHOULD</a> be similar to the
functionality provided in <a href="#XSLT20">XSLT 2.0</a>, such as
by functions <code>format-date()</code>,
<code>format-time()</code>, <code>format-dateTime()</code>.</p>
<p><img src="http://www.w3.org/Icons/green-ball.gif" alt=
"green status" /> <em>Status:</em> this requirement has been
met.</p>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="default-values-for-external-variables" id=
"default-values-for-external-variables"></a>2.3.5 Default values
for external variables</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-must">MUST</a> have a mechanism
to specify default values for external variables.</p>
<p><img src="http://www.w3.org/Icons/green-ball.gif" alt=
"green status" /> <em>Status:</em> this requirement has been
met.</p>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="non-deterministic-external-functions" id=
"non-deterministic-external-functions"></a>2.3.6 Non-deterministic
external functions</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-must">MUST</a> provide a way to
denote that an external function is non-deterministic.</p>
<p><img src="http://www.w3.org/Icons/green-ball.gif" alt=
"green status" /> <em>Status:</em> this requirement has been
met.</p>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="positional-grouping" id=
"positional-grouping"></a>2.3.7 Positional grouping</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-should">SHOULD</a> provide a
facility for positional grouping of items in a sequence according
to specified partitioning conditions.</p>
<p><img src="http://www.w3.org/Icons/green-ball.gif" alt=
"green status" /> <em>Status:</em> this requirement has been
met.</p>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="windowing" id="windowing"></a>2.3.8 Windowing</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-should">SHOULD</a> provide a
way to iterate over a sequence by several values at a time.</p>
<p><img src="http://www.w3.org/Icons/green-ball.gif" alt=
"green status" /> <em>Status:</em> this requirement has been
met.</p>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="output-numbering" id="output-numbering"></a>2.3.9
Output numbering</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-should">SHOULD</a> provide a
mechanism to associate ordinal numbers with the items returned by a
FLWOR expression.</p>
<p><img src="http://www.w3.org/Icons/green-ball.gif" alt=
"green status" /> <em>Status:</em> this requirement has been
met.</p>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="dynamic-creation-of-namespace-bindings" id=
"dynamic-creation-of-namespace-bindings"></a>2.3.10 Dynamic
creation of namespace bindings</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-should">SHOULD</a> allow
dynamic creation of namespace bindings.</p>
<p><img src="http://www.w3.org/Icons/green-ball.gif" alt=
"green status" /> <em>Status:</em> this requirement has been
met.</p>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="declaration-of-serialization-parameters" id=
"declaration-of-serialization-parameters"></a>2.3.11 Declaration of
serialization parameters</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-should">SHOULD</a> have a
mechanism to specify serialization parameters in the query
prolog.</p>
<p><img src="http://www.w3.org/Icons/green-ball.gif" alt=
"green status" /> <em>Status:</em> this requirement has been
met.</p>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="node-references" id="node-references"></a>2.3.12 Node
references</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-should">SHOULD</a> support
creation of a reference to an existing node having the following
properties:</p>
<p>a) the reference could be included in a constructed element</p>
<p>b) the reference can be dereferenced, returning the original
node with the original node id.</p>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="outer-for" id="outer-for"></a>2.3.13 Outer for</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-should">SHOULD</a> provide
additional mechanisms to specify joins between sequences. A
possible approach would be to add an "<em>outer-for</em>" clause to
the FLWOR expression to specify variable binding which is
guaranteed to be bound to an empty sequence if there are no other
bindings generated.</p>
<p><img src="http://www.w3.org/Icons/green-ball.gif" alt=
"green status" /> <em>Status:</em> this requirement has been
met.</p>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="type-declaration-for-context-item" id=
"type-declaration-for-context-item"></a>2.3.14 Type declaration for
context item</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-should">SHOULD</a> allow
explicit type declaration for the context item.</p>
<p><img src="http://www.w3.org/Icons/green-ball.gif" alt=
"green status" /> <em>Status:</em> this requirement has been
met.</p>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="support-for-new-data-types" id=
"support-for-new-data-types"></a>2.3.15 Support for new data
types</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-should">SHOULD</a> support new
data types introduced in <a href="#XMLSchema11rec">XML Schema
1.1</a>.</p>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="higher-order-functions" id=
"higher-order-functions"></a>2.3.16 Higher order functions</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-may">MAY</a> provide an ability
to pass a function as an argument to another function and to invoke
a function that has been passed as an argument.</p>
<p><img src="http://www.w3.org/Icons/green-ball.gif" alt=
"green status" /> <em>Status:</em> this requirement has been met.
(The proposal is not yet integrated into our internal Working
Draft.)</p>
<p>XQuery 3.0 <a href="#terminology-may">MAY</a> also provide the
ability to define anonymous functions e.g., lambda expressions.</p>
<p><img src="http://www.w3.org/Icons/green-ball.gif" alt=
"green status" /> <em>Status:</em> this requirement has been met.
(The proposal is not yet integrated into our internal Working
Draft.)</p>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="conditional-constructors" id=
"conditional-constructors"></a>2.3.17 Conditional constructors</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-may">MAY</a> add a language
extension to the node constructors to specify, in a compact
notation, that a node should be constructed only if its typed value
would not be an empty sequence or if it would satisfy some other
condition.</p>
<p><img src="http://www.w3.org/Icons/green-ball.gif" alt=
"green status" /> <em>Status:</em> this requirement is already met
by XQuery 1.0, there is no need to introduce new syntax. Either of
the following solutions works:</p>
<div class="exampleInner">
<pre>
if ($mentor) then attribute mentor { $mentor } else ()
</pre></div>
<div class="exampleInner">
<pre>
(attribute mentor { $mentor })[$mentor]
</pre></div>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="validation" id="validation"></a>2.3.18 Validation</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-may">MAY</a> provide a
mechanism to validate an element or document node with respect to a
global named type</p>
<p><img src="http://www.w3.org/Icons/green-ball.gif" alt=
"green status" /> <em>Status:</em> this requirement has been
met.</p>
<p>or against non-global element declarations or types.</p>
<p><img src="http://www.w3.org/Icons/red-ball.gif" alt=
"red status" /> <em>Status:</em> this requirement has not been
met.</p>
<p>XQuery 3.0 <a href="#terminology-may">MAY</a> provide a
mechanism to validate an element or document node against a named
schema without importing the schema.</p>
<p><img src="http://www.w3.org/Icons/red-ball.gif" alt=
"red status" /> <em>Status:</em> this requirement has not been
met.</p>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="type-expressions" id="type-expressions"></a>2.3.19
Type expressions</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-may">MAY</a> provide a way to
compare the type of an expression to the type of another expression
without exposing the type itself.</p>
<p><img src="http://www.w3.org/Icons/red-ball.gif" alt=
"red status" /> <em>Status:</em> this requirement has not been
met.</p>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="module-composition-restrictions" id=
"module-composition-restrictions"></a>2.3.20 Module composition
restrictions</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-may">MAY</a> relax the
restrictions on the module import feature relating to forward
references and circular imports.</p>
<p><img src="http://www.w3.org/Icons/green-ball.gif" alt=
"green status" /> <em>Status:</em> this requirement has been
met.</p>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="invocation-of-external-functionality" id=
"invocation-of-external-functionality"></a>2.3.21 Invocation of
external functionality</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-may">MAY</a> provide a
normative way to invoke external functions and modules that are not
implemented in XQuery, such as functions defined as web services or
XSLT functions and templates.</p>
</dd>
</dl>
</div>
<div class="div3">
<h4><a name="static-typing-extensions" id=
"static-typing-extensions"></a>2.3.22 Static typing extensions</h4>
<dl>
<dd>
<p>XQuery 3.0 <a href="#terminology-may">MAY</a> extend static
typing rules.</p>
<p><img src="http://www.w3.org/Icons/red-ball.gif" alt=
"red status" /> <em>Status:</em> this requirement has not been met.
Static typing is no longer a normative part of XQuery 3.0.</p>
</dd>
</dl>
</div>
</div>
</div>
<div class="div1">
<h2><a name="references" id="references"></a>3 References</h2>
<div class="div2">
<h3><a name="normative-references" id=
"normative-references"></a>3.1 Normative</h3>
<dl>
<dt class="label"><a name="XQ10" id="XQ10"></a>XQuery 1.0</dt>
<dd><a href="http://www.w3.org/TR/xquery/">XQuery 1.0: An XML Query
Language</a>, W3C Recommendation, 23 January 2007 and references
therein. (See http://www.w3.org/TR/xquery.)</dd>
<dt class="label"><a name="XSLT20" id="XSLT20"></a>XSLT 2.0</dt>
<dd><a href="http://www.w3.org/TR/xslt20/">XSL Transformations
(XSLT) Version 2.0</a>, W3C Recommendation, 23 January 2007 and
references therein. (See http://www.w3.org/TR/xslt20/.)</dd>
<dt class="label"><a name="XDM" id="XDM"></a>XDM</dt>
<dd><a href="http://www.w3.org/TR/xpath-datamodel/">XQuery 1.0 and
XPath 2.0 Data Model (XDM)</a>, W3C Recommendation, 23 January 2007
(See http://www.w3.org/TR/xpath-datamodel/.)</dd>
<dt class="label"><a name="XQ10R" id="XQ10R"></a>XQuery 1.0
requirements</dt>
<dd><a href="http://www.w3.org/TR/xquery-requirements/">XML Query
(XQuery) Requirements</a>, W3C Working Draft 3 June 2005 (See
http://www.w3.org/TR/xquery-requirements.)</dd>
<dt class="label"><a name="UpdateRequirements" id=
"UpdateRequirements"></a>Update Requirements</dt>
<dd><a href=
"http://www.w3.org/TR/xquery-update-requirements/">XQuery Update
Facility Requirements</a>, W3C Working Draft, Feb. 2005. (See
http://www.w3.org/TR/xquery-update-requirements.)</dd>
<dt class="label"><a name="FullTextRequirements" id=
"FullTextRequirements"></a>Full-Text Requirements</dt>
<dd><a href=
"http://www.w3.org/TR/xquery-full-text-requirements/">XQuery and
XPath Full-Text Requirements</a>, W3C Working Draft, May 2003. (See
http://www.w3.org/TR/xquery-full-text-requirements.)</dd>
</dl>
</div>
<div class="div2">
<h3><a name="non-normative-references" id=
"non-normative-references"></a>3.2 Non-normative</h3>
<p>The following references are some of the works considered by the
WG in deriving its requirements.</p>
<dl>
<dt class="label"><a name="XML" id="XML"></a>XML</dt>
<dd><a href="http://www.w3.org/TR/REC-xml/">Extensible Markup
Language (XML) 1.0 (Fourth Edition)</a>. W3C Recommendation, 29
September 2006. (See
http://www.w3.org/TR/1998/REC-xml-19980210.)</dd>
<dt class="label"><a name="XMLSchema0" id="XMLSchema0"></a>XML
Schema Part 0</dt>
<dd><a href="http://www.w3.org/TR/xmlschema-0/">XML Schema Part 0:
Primer Second Edition</a>, W3C Recommendation 28 October 2004. (See
http://www.w3.org/TR/xmlschema-0/.)</dd>
<dt class="label"><a name="XMLSchema1" id="XMLSchema1"></a>XML
Schema Part 1</dt>
<dd><a href="http://www.w3.org/TR/xmlschema-1/">XML Schema Part 1:
Structures Second Edition</a>, W3C Recommendation 28 October 2004.
(See http://www.w3.org/TR/xmlschema-1/.)</dd>
<dt class="label"><a name="XMLSchema2" id="XMLSchema2"></a>XML
Schema Part 2</dt>
<dd><a href="http://www.w3.org/TR/xmlschema-2/">XML Schema Part 2:
Datatypes Second Edition</a>, W3C Recommendation 28 October 2004.
(See http://www.w3.org/TR/xmlschema-2/.)</dd>
<dt class="label"><a name="XMLSchema11rec" id=
"XMLSchema11rec"></a>XML Schema 1.1 requirements</dt>
<dd><a href="http://www.w3.org/TR/xmlschema-11-req/">Requirements
for XML Schema 1.1</a>, W3C Working Draft, 2003. (See
http://www.w3.org/TR/xmlschema-11-req/.)</dd>
<dt class="label"><a name="Kay06" id="Kay06"></a>Kay06</dt>
<dd>"Positional Grouping in XQuery", Kay, M.H. XIME-P International
workshop proceedings, 2006</dd>
<dt class="label"><a name="Colby05" id="Colby05"></a>Colby05</dt>
<dd>"Extending XQuery for Analytics", Beyer K., Chamberlin D. et
al. SIGMOD 2005</dd>
<dt class="label"><a name="Borkar04" id=
"Borkar04"></a>Borkar04</dt>
<dd>"Extending XQuery for Grouping, Duplicate Elimination, and
Outer Joins.", Borkar V. and Carey M. XML 2004, Idealliance</dd>
</dl>
</div>
</div>
</div>
</body>
</html>