Status of this Document
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 W3C technical reports index at
http://www.w3.org/TR/.
This is one document in a set of eight documents that have
progressed to Recommendation together (XQuery 1.0, XQueryX 1.0,
XSLT 2.0, Data Model, Functions and Operators, Formal Semantics,
Serialization, XPath 2.0).
This is a Recommendation
of the W3C. It has been developed by the W3C XML Query Working Group, which is
part of the XML
Activity.
This document has been reviewed by W3C Members, by software
developers, and by other W3C groups and interested parties, and is
endorsed by the Director as a W3C Recommendation. It is a stable
document and may be used as reference material or cited from
another document. W3C's role in making the Recommendation is to
draw attention to the specification and to promote its widespread
deployment. This enhances the functionality and interoperability of
the Web.
This document incorporates minor changes made against the
Proposed
Recommendation of 21 November 2006; please see the public
disposition of comments for details. Changes to this document since
the Proposed
Recommendation are detailed in the D
Change log.
Please report errors in this document using W3C's public Bugzilla system
(instructions can be found at http://www.w3.org/XML/2005/04/qt-bugzilla).
If access to that system is not feasible, you may send your
comments to the W3C XSLT/XPath/XQuery public comments mailing list,
public-qt-comments@w3.org.
It will be very helpful if you include the string “[XQX]” in the
subject line of your report, whether made in Bugzilla or in email.
Each Bugzilla entry and email message should contain only one error
report. Archives of the comments and responses are available at
http://lists.w3.org/Archives/Public/public-qt-comments/.
This document was produced by a group operating under the
5
February 2004 W3C Patent Policy. W3C maintains a public
list of any patent disclosures 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
Essential Claim(s) must disclose the information in accordance
with
section 6 of the W3C Patent Policy.
1
Introduction
The [XML Query 1.0
Requirements] states that "The XML Query Language MAY have more
than one syntax binding. One query language syntax MUST be
convenient for humans to read and write. One query language syntax
MUST be expressed in XML in a way that reflects the underlying
structure of the query."
XQueryX is an XML representation of an XQuery. It was created by
mapping the productions of the XQuery grammar into XML productions.
The result is not particularly convenient for humans to read and
write, but it is easy for programs to parse, and because XQueryX is
represented in XML, standard XML tools can be used to create,
interpret, or modify queries.
Note:
Because the two syntaxes are merely different grammars that
express the same query semantics, they share all aspects of an
XQuery processing system except for the component that recognizes
and translates the source representation of a query (that is, the
parser). The aspects that are shared include both the static
context and the dynamic context that are defined in [XQuery 1.0: An XML Query Language].
There are several environments in which XQueryX may be
useful:
-
Parser Reuse. In heterogeneous environments, a variety
of systems may be used to execute a query. One parser can generate
XQueryX for all of these systems.
-
Queries on Queries. Because XQueryX is represented in
XML, queries can be queried and can be transformed into new
queries. For instance, a query can be performed against a set of
XQueryX queries to determine which queries use FLWOR expressions to
range over a set of invoices.
-
Generating Queries. In some XML-oriented programming
environments, it may be more convenient to build a query in its
XQueryX representation than in the corresponding XQuery
representation, since ordinary XML tools can be used.
-
Embedding Queries in XML. XQueryX can be embedded
directly in an XML document.
The most recent versions of the XQueryX XML Schema and the
XQueryX XSLT stylesheet are available at http://www.w3.org/2005/XQueryX/xqueryx.xsd
and http://www.w3.org/2005/XQueryX/xqueryx.xsl,
respectively.
2 Mapping the XQuery
Syntax
XQueryX is an XML representation of the abstract syntax found in
Appendix A of [XQuery 1.0: An XML Query
Language]. The XQueryX syntax is defined by the XQueryX Schema,
which is specified in 4 An XML Schema for the
XQuery XML Syntax. The XQueryX semantics are defined by a
stylesheet that maps an instance of XQueryX to an instance of
XQuery; see B Transforming XQueryX to
XQuery.
The main data structure in the XQueryX Schema is the set of
types that describe expressions. We have chosen to model
expressions using substitution groups, with an "expr" abstract base
class and a number of intermediate abstract classes.
Consider the following productions from the abstract syntax:
FLWORExpr ::= (ForClause | LetClause)+ WhereClause? OrderByClause? "return" ExprSingle
ForClause ::= "for" "$" VarName TypeDeclaration? PositionalVar? "in"
ExprSingle ("," "$" VarName TypeDeclaration? PositionalVar?
"in" ExprSingle)*
LetClause ::= "let" "$" VarName TypeDeclaration? ":=" ExprSingle
("," "$" VarName TypeDeclaration? ":=" ExprSingle)*
WhereClause ::= "where" ExprSingle
The following XQueryX Schema definitions reflect the structure
of those productions from that abstract syntax:
<!-- The base class -->
<xsd:complexType name="expr"/>
<xsd:element name="expr" type="expr" abstract="true"/>
<!-- Simple wrapper class -->
<xsd:complexType name="exprWrapper">
<xsd:sequence>
<xsd:element ref="expr"/>
</xsd:sequence>
</xsd:complexType>
<xsd:complexType name="flworExpr">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:choice maxOccurs="unbounded">
<xsd:element ref="forClause"/>
<xsd:element ref="letClause"/>
</xsd:choice>
<xsd:element name="whereClause" minOccurs="0"/>
<xsd:element name="orderByClause" minOccurs="0"/>
<xsd:element name="returnClause"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="flworExpr" type="flworExpr" substitutionGroup="expr"/>
<xsd:element name="forClause">
<xsd:complexType>
<xsd:sequence>
<xsd:element ref="forClauseItem" maxOccurs="unbounded"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="forClauseItem">
<xsd:complexType>
<xsd:sequence>
<xsd:element ref="typedVariableBinding"/>
<xsd:element ref="positionalVariableBinding" minOccurs="0"/>
<xsd:element name="forExpr" type="exprWrapper"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="letClause">
<xsd:complexType>
<xsd:sequence>
<xsd:element ref="letClauseItem" maxOccurs="unbounded"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="letClauseItem">
<xsd:complexType>
<xsd:sequence>
<xsd:element ref="typedVariableBinding"/>
<xsd:element name="letExpr" type="exprWrapper"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="whereClause" type="exprWrapper"/>
<xsd:element name="returnClause" type="exprWrapper"/>
Since XQuery uses the expression production liberally to allow
expressions to be flexibly combined, XQueryX uses the exprWrapper
type in embedded contexts to allow all expression types to
occur.
3 Examples from the XML
Query Use Cases in XML Syntax
Three of following examples are based on the data and queries in
the XMP (Experiences and Exemplars) use case in [XML Query Use Cases], while a fourth
example is based on the data and queries in the NS (Queries Using
Namespaces) use case. For each example, we show the English
description of the query, the XQuery solution given in [XML Query Use Cases], an XQueryX solution,
and the XQuery that results from applying the XQueryX-to-XQuery
transformation defined by the stylesheet in B Transforming XQueryX to XQuery to the
XQueryX solution. That produced XQuery is presented only as a
sanity-check — the intent of the stylesheet is not to create the
identical XQuery expression given in [XML Query Use Cases], but to produce
a valid XQuery expression with the same semantics. The
semantics of the XQueryX solution are determined by the semantics
of the XQuery expression that results from that transformation. The
"correctness" of that transformation is determined by asking the
following the question: Can some XQueryX processor QX process some
XQueryX document D1 to produce results R1, after which the
stylesheet is used to translate D1 into an XQuery expression E1
that, when processed by some XQuery processor Q, produces results
R2 that are equivalent (under some meaningful definition of
"equivalent") to results R1?
Comparison of the results of the XQueryX-to-XQuery
transformation given in this document with the XQuery solutions in
the [XML Query Use Cases] may be
helpful in evaluating the correctness of the XQueryX solution in
each example.
The XQuery Use Cases solution given for each example is provided
only to assist readers of this document in understanding the
XQueryX solution. There is no intent to imply that this document
specifies a "compilation" or "transformation" of XQuery syntax into
XQueryX syntax.
In the following examples, note that path expressions are
expanded to show their structure. Also, note that the prefix syntax
for binary operators like "and" makes the precedence explicit. In
general, humans find it easier to read an XML representation that
does not expand path expressions, but it is less convenient for
programmatic representation and manipulation. XQueryX is designed
as a language that is convenient for production and modification by
software, and not as a convenient syntax for humans to read and
write.
Finally, please note that white space, including new lines, have
been added to some of the XQueryX documents and XQuery expressions
for readability. That additional white space is not produced by the
XQueryX-to-XQuery transformation.
3.1 Example 1
Here is Q1 from the [XML Query Use
Cases], use case XMP (Experiences and Exemplars): "List books
published by Addison-Wesley after 1991, including their year and
title."
3.1.1 XQuery
solution in XQuery Use Cases:
<bib>
{
for $b in doc("http://bstore1.example.com/bib.xml")/bib/book
where $b/publisher = "Addison-Wesley" and $b/@year > 1991
return
<book year="{ $b/@year }">
{ $b/title }
</book>
}
</bib>
3.1.2 A
Solution in XQueryX:
<?xml version="1.0"?>
<xqx:module xmlns:xqx="http://www.w3.org/2005/XQueryX"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3.org/2005/XQueryX
http://www.w3.org/2005/XQueryX/xqueryx.xsd">
<xqx:mainModule>
<xqx:queryBody>
<xqx:elementConstructor>
<xqx:tagName>bib</xqx:tagName>
<xqx:elementContent>
<xqx:flworExpr>
<xqx:forClause>
<xqx:forClauseItem>
<xqx:typedVariableBinding>
<xqx:varName>b</xqx:varName>
</xqx:typedVariableBinding>
<xqx:forExpr>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:functionCallExpr>
<xqx:functionName>doc</xqx:functionName>
<xqx:arguments>
<xqx:stringConstantExpr>
<xqx:value>http://bstore1.example.com/bib.xml</xqx:value>
</xqx:stringConstantExpr>
</xqx:arguments>
</xqx:functionCallExpr>
</xqx:filterExpr>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:nameTest>bib</xqx:nameTest>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:nameTest>book</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:forExpr>
</xqx:forClauseItem>
</xqx:forClause>
<xqx:whereClause>
<xqx:andOp>
<xqx:firstOperand>
<xqx:equalOp>
<xqx:firstOperand>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:varRef>
<xqx:name>b</xqx:name>
</xqx:varRef>
</xqx:filterExpr>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:nameTest>publisher</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:firstOperand>
<xqx:secondOperand>
<xqx:stringConstantExpr>
<xqx:value>Addison-Wesley</xqx:value>
</xqx:stringConstantExpr>
</xqx:secondOperand>
</xqx:equalOp>
</xqx:firstOperand>
<xqx:secondOperand>
<xqx:greaterThanOp>
<xqx:firstOperand>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:varRef>
<xqx:name>b</xqx:name>
</xqx:varRef>
</xqx:filterExpr>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>attribute</xqx:xpathAxis>
<xqx:nameTest>year</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:firstOperand>
<xqx:secondOperand>
<xqx:integerConstantExpr>
<xqx:value>1991</xqx:value>
</xqx:integerConstantExpr>
</xqx:secondOperand>
</xqx:greaterThanOp>
</xqx:secondOperand>
</xqx:andOp>
</xqx:whereClause>
<xqx:returnClause>
<xqx:elementConstructor>
<xqx:tagName>book</xqx:tagName>
<xqx:attributeList>
<xqx:attributeConstructor>
<xqx:attributeName>year</xqx:attributeName>
<xqx:attributeValueExpr>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:varRef>
<xqx:name>b</xqx:name>
</xqx:varRef>
</xqx:filterExpr>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>attribute</xqx:xpathAxis>
<xqx:nameTest>year</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:attributeValueExpr>
</xqx:attributeConstructor>
</xqx:attributeList>
<xqx:elementContent>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:varRef>
<xqx:name>b</xqx:name>
</xqx:varRef>
</xqx:filterExpr>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:nameTest>title</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:elementContent>
</xqx:elementConstructor>
</xqx:returnClause>
</xqx:flworExpr>
</xqx:elementContent>
</xqx:elementConstructor>
</xqx:queryBody>
</xqx:mainModule>
</xqx:module>
3.1.3 Transformation of XQueryX
Solution into XQuery
Application of the stylesheet in B
Transforming XQueryX to XQuery to the XQueryX solution
results in:
<bib>{
for $b in doc("http://bstore1.example.com/bib.xml")/child::bib/child::book
where (($b/child::publisher = "Addison-Wesley") and ($b/attribute::year > 1991))
return <book year="{$b/attribute::year}">{$b/child::title}</book>
}</bib>
3.1.4
Corresponding Grammar Abstract Parse Tree
For comparison, here is the abstract parse tree corresponding to
the XQuery for Example 1, as produced by the XQuery grammar applets
found at http://www.w3.org/2005/qt-applets/xqueryApplet.html.
XPath2
QueryList
Module
MainModule
Prolog
QueryBody
Expr
PathExpr
Constructor
DirectConstructor
DirElemConstructor >
LessThanOpOrTagO <
TagQName bib
DirAttributeList
StartTagClose >
DirElemContent
ElementContentChar
DirElemContent
ElementContentChar
DirElemContent
CommonContent
EnclosedExpr
Lbrace {
Expr
FLWORExpr
ForClause
VarName
QName b
PathExpr
FunctionCall
FunctionQName doc
PathExpr
StringLiteral "http://bstore1.example.com/bib.xml"
StepExpr
AbbrevForwardStep
NodeTest
NameTest
QName bib
StepExpr
AbbrevForwardStep
NodeTest
NameTest
QName book
WhereClause
AndExpr and
ComparisonExpr =
PathExpr
VarName
QName b
StepExpr
AbbrevForwardStep
NodeTest
NameTest
QName publisher
PathExpr
StringLiteral "Addison-Wesley"
ComparisonExpr >
PathExpr
VarName
QName b
StepExpr
AbbrevForwardStep @
NodeTest
NameTest
QName year
PathExpr
IntegerLiteral 1991
PathExpr
Constructor
DirectConstructor
DirElemConstructor >
LessThanOpOrTagO <
TagQName book
DirAttributeList
S
TagQName year
ValueIndicator =
DirAttributeValue
OpenQuot "
QuotAttrValueContent
CommonContent
EnclosedExpr
Lbrace {
Expr
PathExpr
VarName
QName b
StepExpr
AbbrevForwardStep @
NodeTest
NameTest
QName year
Rbrace }
CloseQuot "
StartTagClose >
DirElemContent
ElementContentChar
DirElemContent
ElementContentChar
DirElemContent
ElementContentChar
DirElemContent
ElementContentChar
DirElemContent
ElementContentChar
DirElemContent
ElementContentChar
DirElemContent
CommonContent
EnclosedExpr
Lbrace {
Expr
PathExpr
VarName
QName b
StepExpr
AbbrevForwardStep
NodeTest
NameTest
QName title
Rbrace }
DirElemContent
ElementContentChar
DirElemContent
ElementContentChar
DirElemContent
ElementContentChar
DirElemContent
ElementContentChar
DirElemContent </
ElementContentChar
Rbrace }
DirElemContent </
ElementContentChar
3.2 Example 2
Here is Q4 from the [XML Query Use
Cases], use case XMP (Experiences and Exemplars): "For each
author in the bibliography, list the author's name and the titles
of all books by that author, grouped inside a "result"
element."
3.2.1 XQuery
solution in XQuery Use Cases:
<results>
{
let $a := doc("http://bstore1.example.com/bib/bib.xml")//author
for $last in distinct-values($a/last),
$first in distinct-values($a[last=$last]/first)
order by $last, $first
return
<result>
<author>
<last>{ $last }</last>
<first>{ $first }</first>
</author>
{
for $b in doc("http://bstore1.example.com/bib.xml")/bib/book
where some $ba in $b/author
satisfies ($ba/last = $last and $ba/first=$first)
return $b/title
}
</result>
}
</results>
3.2.2 A
solution in XQueryX:
<?xml version="1.0"?>
<xqx:module xmlns:xqx="http://www.w3.org/2005/XQueryX"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3.org/2005/XQueryX
http://www.w3.org/2005/XQueryX/xqueryx.xsd">
<xqx:mainModule>
<xqx:queryBody>
<xqx:elementConstructor>
<xqx:tagName>results</xqx:tagName>
<xqx:elementContent>
<xqx:flworExpr>
<xqx:letClause>
<xqx:letClauseItem>
<xqx:typedVariableBinding>
<xqx:varName>a</xqx:varName>
</xqx:typedVariableBinding>
<xqx:letExpr>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:functionCallExpr>
<xqx:functionName>doc</xqx:functionName>
<xqx:arguments>
<xqx:stringConstantExpr>
<xqx:value>http://bstore1.example.com/bib.xml</xqx:value>
</xqx:stringConstantExpr>
</xqx:arguments>
</xqx:functionCallExpr>
</xqx:filterExpr>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>descendant-or-self</xqx:xpathAxis>
<xqx:anyKindTest/>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:nameTest>author</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:letExpr>
</xqx:letClauseItem>
</xqx:letClause>
<xqx:forClause>
<xqx:forClauseItem>
<xqx:typedVariableBinding>
<xqx:varName>last</xqx:varName>
</xqx:typedVariableBinding>
<xqx:forExpr>
<xqx:functionCallExpr>
<xqx:functionName>distinct-values</xqx:functionName>
<xqx:arguments>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:varRef>
<xqx:name>a</xqx:name>
</xqx:varRef>
</xqx:filterExpr>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:nameTest>last</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:arguments>
</xqx:functionCallExpr>
</xqx:forExpr>
</xqx:forClauseItem>
<xqx:forClauseItem>
<xqx:typedVariableBinding>
<xqx:varName>first</xqx:varName>
</xqx:typedVariableBinding>
<xqx:forExpr>
<xqx:functionCallExpr>
<xqx:functionName>distinct-values</xqx:functionName>
<xqx:arguments>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:varRef>
<xqx:name>a</xqx:name>
</xqx:varRef>
</xqx:filterExpr>
<xqx:predicates>
<xqx:equalOp>
<xqx:firstOperand>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:contextItemExpr/>
</xqx:filterExpr>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:nameTest>last</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:firstOperand>
<xqx:secondOperand>
<xqx:varRef>
<xqx:name>last</xqx:name>
</xqx:varRef>
</xqx:secondOperand>
</xqx:equalOp>
</xqx:predicates>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:nameTest>first</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:arguments>
</xqx:functionCallExpr>
</xqx:forExpr>
</xqx:forClauseItem>
</xqx:forClause>
<xqx:orderByClause>
<xqx:orderBySpec>
<xqx:orderByExpr>
<xqx:varRef>
<xqx:name>last</xqx:name>
</xqx:varRef>
</xqx:orderByExpr>
</xqx:orderBySpec>
<xqx:orderBySpec>
<xqx:orderByExpr>
<xqx:varRef>
<xqx:name>first</xqx:name>
</xqx:varRef>
</xqx:orderByExpr>
</xqx:orderBySpec>
</xqx:orderByClause>
<xqx:returnClause>
<xqx:elementConstructor>
<xqx:tagName>result</xqx:tagName>
<xqx:elementContent>
<xqx:elementConstructor>
<xqx:tagName>author</xqx:tagName>
<xqx:elementContent>
<xqx:elementConstructor>
<xqx:tagName>last</xqx:tagName>
<xqx:elementContent>
<xqx:varRef>
<xqx:name>last</xqx:name>
</xqx:varRef>
</xqx:elementContent>
</xqx:elementConstructor>
<xqx:elementConstructor>
<xqx:tagName>first</xqx:tagName>
<xqx:elementContent>
<xqx:varRef>
<xqx:name>first</xqx:name>
</xqx:varRef>
</xqx:elementContent>
</xqx:elementConstructor>
</xqx:elementContent>
</xqx:elementConstructor>
<xqx:flworExpr>
<xqx:forClause>
<xqx:forClauseItem>
<xqx:typedVariableBinding>
<xqx:varName>b</xqx:varName>
</xqx:typedVariableBinding>
<xqx:forExpr>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:functionCallExpr>
<xqx:functionName>doc</xqx:functionName>
<xqx:arguments>
<xqx:stringConstantExpr>
<xqx:value>http://bstore1.example.com/bib.xml</xqx:value>
</xqx:stringConstantExpr>
</xqx:arguments>
</xqx:functionCallExpr>
</xqx:filterExpr>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:nameTest>bib</xqx:nameTest>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:nameTest>book</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:forExpr>
</xqx:forClauseItem>
</xqx:forClause>
<xqx:whereClause>
<xqx:quantifiedExpr>
<xqx:quantifier>some</xqx:quantifier>
<xqx:quantifiedExprInClause>
<xqx:typedVariableBinding>
<xqx:varName>ba</xqx:varName>
</xqx:typedVariableBinding>
<xqx:sourceExpr>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:varRef>
<xqx:name>b</xqx:name>
</xqx:varRef>
</xqx:filterExpr>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:nameTest>author</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:sourceExpr>
</xqx:quantifiedExprInClause>
<xqx:predicateExpr>
<xqx:andOp>
<xqx:firstOperand>
<xqx:equalOp>
<xqx:firstOperand>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:varRef>
<xqx:name>ba</xqx:name>
</xqx:varRef>
</xqx:filterExpr>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:nameTest>last</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:firstOperand>
<xqx:secondOperand>
<xqx:varRef>
<xqx:name>last</xqx:name>
</xqx:varRef>
</xqx:secondOperand>
</xqx:equalOp>
</xqx:firstOperand>
<xqx:secondOperand>
<xqx:equalOp>
<xqx:firstOperand>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:varRef>
<xqx:name>ba</xqx:name>
</xqx:varRef>
</xqx:filterExpr>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:nameTest>first</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:firstOperand>
<xqx:secondOperand>
<xqx:varRef>
<xqx:name>first</xqx:name>
</xqx:varRef>
</xqx:secondOperand>
</xqx:equalOp>
</xqx:secondOperand>
</xqx:andOp>
</xqx:predicateExpr>
</xqx:quantifiedExpr>
</xqx:whereClause>
<xqx:returnClause>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:varRef>
<xqx:name>b</xqx:name>
</xqx:varRef>
</xqx:filterExpr>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:nameTest>title</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:returnClause>
</xqx:flworExpr>
</xqx:elementContent>
</xqx:elementConstructor>
</xqx:returnClause>
</xqx:flworExpr>
</xqx:elementContent>
</xqx:elementConstructor>
</xqx:queryBody>
</xqx:mainModule>
</xqx:module>
3.2.3 Transformation of XQueryX
Solution into XQuery
Application of the stylesheet in B
Transforming XQueryX to XQuery to the XQueryX solution
results in:
<results>{
let $a:=doc("http://bstore1.example.com/bib.xml")/descendant-or-self::node()/child::author
for $last in distinct-values($a/child::last), $first in distinct-values($a[(./child::last = $last)]/child::first)
order by $last , $first
return <result><author><last>{$last}</last><first>{$first}</first></author>{
for $b in doc("http://bstore1.example.com/bib.xml")/child::bib/child::book
where (some $ba in $b/child::author satisfies (($ba/child::last = $last) and ($ba/child::first = $first)))
return $b/child::title
}</result>
}</results>
3.3 Example 3
Here is Q7 from the [XML Query Use
Cases], use case XMP (Experiences and Exemplars): "List the
titles and years of all books published by Addison-Wesley after
1991, in alphabetic order."
3.3.1 XQuery
solution in XQuery Use Cases:
<bib>
{
for $b in doc("http://bstore1.example.com/bib.xml")//book
where $b/publisher = "Addison-Wesley" and $b/@year > 1991
order by $b/title
return
<book>
{ $b/@year }
{ $b/title }
</book>
}
</bib>
3.3.2 A
solution in XQueryX:
<?xml version="1.0"?>
<xqx:module xmlns:xqx="http://www.w3.org/2005/XQueryX"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3.org/2005/XQueryX
http://www.w3.org/2005/XQueryX/xqueryx.xsd">
<xqx:mainModule>
<xqx:queryBody>
<xqx:elementConstructor>
<xqx:tagName>bib</xqx:tagName>
<xqx:elementContent>
<xqx:flworExpr>
<xqx:forClause>
<xqx:forClauseItem>
<xqx:typedVariableBinding>
<xqx:varName>b</xqx:varName>
</xqx:typedVariableBinding>
<xqx:forExpr>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:functionCallExpr>
<xqx:functionName>doc</xqx:functionName>
<xqx:arguments>
<xqx:stringConstantExpr>
<xqx:value>http://bstore1.example.com/bib.xml</xqx:value>
</xqx:stringConstantExpr>
</xqx:arguments>
</xqx:functionCallExpr>
</xqx:filterExpr>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>descendant-or-self</xqx:xpathAxis>
<xqx:anyKindTest/>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:nameTest>book</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:forExpr>
</xqx:forClauseItem>
</xqx:forClause>
<xqx:whereClause>
<xqx:andOp>
<xqx:firstOperand>
<xqx:equalOp>
<xqx:firstOperand>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:varRef>
<xqx:name>b</xqx:name>
</xqx:varRef>
</xqx:filterExpr>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:nameTest>publisher</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:firstOperand>
<xqx:secondOperand>
<xqx:stringConstantExpr>
<xqx:value>Addison-Wesley</xqx:value>
</xqx:stringConstantExpr>
</xqx:secondOperand>
</xqx:equalOp>
</xqx:firstOperand>
<xqx:secondOperand>
<xqx:greaterThanOp>
<xqx:firstOperand>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:varRef>
<xqx:name>b</xqx:name>
</xqx:varRef>
</xqx:filterExpr>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>attribute</xqx:xpathAxis>
<xqx:nameTest>year</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:firstOperand>
<xqx:secondOperand>
<xqx:integerConstantExpr>
<xqx:value>1991</xqx:value>
</xqx:integerConstantExpr>
</xqx:secondOperand>
</xqx:greaterThanOp>
</xqx:secondOperand>
</xqx:andOp>
</xqx:whereClause>
<xqx:orderByClause>
<xqx:orderBySpec>
<xqx:orderByExpr>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:varRef>
<xqx:name>b</xqx:name>
</xqx:varRef>
</xqx:filterExpr>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:nameTest>title</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:orderByExpr>
</xqx:orderBySpec>
</xqx:orderByClause>
<xqx:returnClause>
<xqx:elementConstructor>
<xqx:tagName>book</xqx:tagName>
<xqx:elementContent>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:varRef>
<xqx:name>b</xqx:name>
</xqx:varRef>
</xqx:filterExpr>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>attribute</xqx:xpathAxis>
<xqx:nameTest>year</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:varRef>
<xqx:name>b</xqx:name>
</xqx:varRef>
</xqx:filterExpr>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:nameTest>title</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:elementContent>
</xqx:elementConstructor>
</xqx:returnClause>
</xqx:flworExpr>
</xqx:elementContent>
</xqx:elementConstructor>
</xqx:queryBody>
</xqx:mainModule>
</xqx:module>
3.3.3 Transformation of XQueryX
Solution into XQuery
Application of the stylesheet in B
Transforming XQueryX to XQuery to the XQueryX solution
results in:
<bib>{
for $b in doc("http://bstore1.example.com/bib.xml")/descendant-or-self::node()/child::book
where (($b/child::publisher = "Addison-Wesley") and ($b/attribute::year > 1991))
order by $b/child::title
return <book>{$b/attribute::year}{$b/child::title}</book>
}</bib>
3.4 Example 4
Here is Q8 from the [XML Query Use
Cases], use case NS (Queries Using Namespaces): "Select all
traders (either seller or high bidder) without negative
comments."
3.4.1 XQuery
solution in XQuery Use Cases:
declare namespace ma = "http://www.example.com/AuctionWatch";
<Q8 xmlns:ma="http://www.example.com/AuctionWatch"
xmlns:eachbay="http://www.example.com/auctioneers#eachbay"
xmlns:xlink="http://www.w3.org/1999/xlink">
{
for $s in doc("auction.xml")//ma:Trading_Partners/(ma:Seller | ma:High_Bidder)
where $s/*:NegativeComments = 0
return $s
}
</Q8>
3.4.2 A
solution in XQueryX:
<?xml version="1.0"?>
<xqx:module xmlns:xqx="http://www.w3.org/2005/XQueryX"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3.org/2005/XQueryX
http://www.w3.org/2005/XQueryX/xqueryx.xsd">
<xqx:mainModule>
<xqx:prolog>
<xqx:namespaceDecl>
<xqx:prefix>ma</xqx:prefix>
<xqx:uri>http://www.example.com/AuctionWatch</xqx:uri>
</xqx:namespaceDecl>
</xqx:prolog>
<xqx:queryBody>
<xqx:elementConstructor>
<xqx:tagName>Q8</xqx:tagName>
<xqx:attributeList>
<xqx:namespaceDeclaration>
<xqx:prefix>ma</xqx:prefix>
<xqx:uri>http://www.example.com/AuctionWatch</xqx:uri>
</xqx:namespaceDeclaration>
<xqx:namespaceDeclaration>
<xqx:prefix>eachbay</xqx:prefix>
<xqx:uri>http://www.example.com/auctioneers#eachbay</xqx:uri>
</xqx:namespaceDeclaration>
<xqx:namespaceDeclaration>
<xqx:prefix>xlink</xqx:prefix>
<xqx:uri>http://www.w3.org/1999/xlink</xqx:uri>
</xqx:namespaceDeclaration>
</xqx:attributeList>
<xqx:elementContent>
<xqx:flworExpr>
<xqx:forClause>
<xqx:forClauseItem>
<xqx:typedVariableBinding>
<xqx:varName>s</xqx:varName>
</xqx:typedVariableBinding>
<xqx:forExpr>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:functionCallExpr>
<xqx:functionName xqx:prefix="fn">doc</xqx:functionName>
<xqx:arguments>
<xqx:stringConstantExpr>
<xqx:value>auction.xml</xqx:value>
</xqx:stringConstantExpr>
</xqx:arguments>
</xqx:functionCallExpr>
</xqx:filterExpr>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>descendant-or-self</xqx:xpathAxis>
<xqx:anyKindTest/>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:nameTest xqx:prefix="ma">Trading_Partners</xqx:nameTest>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:parenthesizedExpr>
<xqx:unionOp>
<xqx:firstOperand>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:nameTest xqx:prefix="ma">Seller</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:firstOperand>
<xqx:secondOperand>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:nameTest xqx:prefix="ma">High_Bidder</xqx:nameTest>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:secondOperand>
</xqx:unionOp>
</xqx:parenthesizedExpr>
</xqx:filterExpr>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:forExpr>
</xqx:forClauseItem>
</xqx:forClause>
<xqx:whereClause>
<xqx:equalOp>
<xqx:firstOperand>
<xqx:pathExpr>
<xqx:stepExpr>
<xqx:filterExpr>
<xqx:varRef>
<xqx:name>s</xqx:name>
</xqx:varRef>
</xqx:filterExpr>
</xqx:stepExpr>
<xqx:stepExpr>
<xqx:xpathAxis>child</xqx:xpathAxis>
<xqx:Wildcard>
<xqx:star/>
<xqx:NCName>NegativeComments</xqx:NCName>
</xqx:Wildcard>
</xqx:stepExpr>
</xqx:pathExpr>
</xqx:firstOperand>
<xqx:secondOperand>
<xqx:integerConstantExpr>
<xqx:value>0</xqx:value>
</xqx:integerConstantExpr>
</xqx:secondOperand>
</xqx:equalOp>
</xqx:whereClause>
<xqx:returnClause>
<xqx:varRef>
<xqx:name>s</xqx:name>
</xqx:varRef>
</xqx:returnClause>
</xqx:flworExpr>
</xqx:elementContent>
</xqx:elementConstructor>
</xqx:queryBody>
</xqx:mainModule>
</xqx:module>
3.4.3 Transformation of XQueryX
Solution into XQuery
Application of the stylesheet in B
Transforming XQueryX to XQuery to the XQueryX solution
results in:
declare namespace ma="http://www.example.com/AuctionWatch";
<Q8 xmlns:ma="http://www.example.com/AuctionWatch" xmlns:eachbay="http://www.example.com/auctioneers#eachbay" xmlns:xlink="http://www.w3.org/1999/xlink">{
for $s in fn:doc("auction.xml")/descendant-or-self::node()/child::ma:Trading_Partners/((child::ma:Seller union child::ma:High_Bidder))
where ($s/child::*:NegativeComments = 0)
return $s
}</Q8>
4 An XML Schema for the XQuery
XML Syntax
Here is the XML Schema against which XQueryX documents must be
valid.
<?xml version="1.0"?>
<!--
Changes from CR document:
* revised the text describing the trivial embedding feature (bug #2611)
* refined the content model for xqx:stepExpr and xqx:pathExpr (bug #2523)
* fixed the handling of an empty xqx:Wildcard element (bug #3022)
* removed the unnecessary <xqx:parenthesizedExpr/> element (#3333)
* always generated braces associated with a computed PI constructor value (bug #3442)
* escape/quote "<" and whitespace chars other than #x20 (bugs #3446 and #3474)
* support schemaImport and moduleImport with multiple <xqx:targetLocation>s (bug #3520)
* restructure prolog details in preparation for future XQuery features
-->
<!-- Readers of this schema are reminded that the default value for both
minOccurs and maxOccurs is "1". -->
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns="http://www.w3.org/2005/XQueryX"
targetNamespace="http://www.w3.org/2005/XQueryX"
elementFormDefault="qualified" attributeFormDefault="qualified">
<!-- A few helper declarations -->
<xsd:complexType name="emptyContent"/>
<xsd:element name="NCName" type="xsd:NCName"/>
<xsd:complexType name="QName">
<xsd:simpleContent>
<xsd:extension base="xsd:NCName">
<xsd:attribute name="prefix" type="xsd:NCName" use="optional"/>
</xsd:extension>
</xsd:simpleContent>
</xsd:complexType>
<!-- The base class -->
<xsd:complexType name="expr"/>
<xsd:element name="expr" type="expr" abstract="true"/>
<!-- A list of expressions -->
<xsd:complexType name="exprList">
<xsd:sequence>
<xsd:element ref="expr" minOccurs="0" maxOccurs="unbounded"/>
</xsd:sequence>
</xsd:complexType>
<xsd:complexType name="exprWrapperOptional">
<xsd:sequence>
<xsd:element ref="expr" minOccurs="0"/>
</xsd:sequence>
</xsd:complexType>
<!-- Simple wrapper class -->
<xsd:complexType name="exprWrapper">
<xsd:sequence>
<xsd:element ref="expr"/>
</xsd:sequence>
</xsd:complexType>
<!-- constant expressions. We have 4 different subclasses for this -->
<xsd:complexType name="constantExpr">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element name="value" type="xsd:anyType"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="constantExpr" type="constantExpr" abstract="true" substitutionGroup="expr"/>
<xsd:complexType name="integerConstantExpr">
<xsd:complexContent>
<xsd:restriction base="constantExpr">
<xsd:sequence>
<xsd:element name="value" type="xsd:integer"/>
</xsd:sequence>
</xsd:restriction>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="integerConstantExpr" type="integerConstantExpr" substitutionGroup="constantExpr"/>
<xsd:complexType name="decimalConstantExpr">
<xsd:complexContent>
<xsd:restriction base="constantExpr">
<xsd:sequence>
<xsd:element name="value" type="xsd:decimal"/>
</xsd:sequence>
</xsd:restriction>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="decimalConstantExpr" type="decimalConstantExpr" substitutionGroup="constantExpr"/>
<xsd:complexType name="doubleConstantExpr">
<xsd:complexContent>
<xsd:restriction base="constantExpr">
<xsd:sequence>
<xsd:element name="value" type="xsd:double"/>
</xsd:sequence>
</xsd:restriction>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="doubleConstantExpr" type="doubleConstantExpr" substitutionGroup="constantExpr"/>
<xsd:complexType name="stringConstantExpr">
<xsd:complexContent>
<xsd:restriction base="constantExpr">
<xsd:sequence>
<xsd:element name="value" type="xsd:string"/>
</xsd:sequence>
</xsd:restriction>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="stringConstantExpr" type="stringConstantExpr" substitutionGroup="constantExpr"/>
<!-- Variables -->
<xsd:complexType name="varRef">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element name="name" type="QName"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="varRef" type="varRef" substitutionGroup="expr"/>
<!-- root and context-item expressions -->
<!-- rootExpr deleted per Bugzilla Bug #2523 -->
<xsd:complexType name="contextItemExpr">
<xsd:complexContent>
<xsd:extension base="expr"/>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="contextItemExpr" type="contextItemExpr" substitutionGroup="expr"/>
<!-- Pragmas and extension expressions -->
<xsd:element name="pragma">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="pragmaName" type="QName"/>
<xsd:element name="pragmaContents" type="xsd:string"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:complexType name="extensionExpr">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element ref="pragma" maxOccurs="unbounded"/>
<xsd:element name="argExpr" type="exprWrapper" minOccurs="0"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="extensionExpr" type="extensionExpr" substitutionGroup="expr"/>
<xsd:complexType name="functionCallExpr">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element name="functionName" type="QName"/>
<xsd:element name="arguments" type="exprList" minOccurs="0"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="functionCallExpr" type="functionCallExpr" substitutionGroup="expr"/>
<!-- Constructor functions -->
<xsd:complexType name="constructorFunctionExpr">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element name="typeName" type="QName"/>
<xsd:element name="argExpr" type="exprWrapper"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="constructorFunctionExpr" type="constructorFunctionExpr" substitutionGroup="expr"/>
<xsd:complexType name="sequenceExpr">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element ref="expr" minOccurs="0" maxOccurs="unbounded"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="sequenceExpr" type="sequenceExpr" substitutionGroup="expr"/>
<xsd:complexType name="rangeSequenceExpr">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element name="startExpr" type="exprWrapper"/>
<xsd:element name="endExpr" type="exprWrapper"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="rangeSequenceExpr" type="rangeSequenceExpr" substitutionGroup="expr"/>
<!-- Builtin operator expressions -->
<xsd:complexType name="operatorExpr">
<xsd:complexContent>
<xsd:extension base="expr"/>
</xsd:complexContent>
</xsd:complexType>
<xsd:complexType name="unaryOperatorExpr">
<xsd:complexContent>
<xsd:extension base="operatorExpr">
<xsd:sequence>
<xsd:element name="operand" type="exprWrapper"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:complexType name="binaryOperatorExpr">
<xsd:complexContent>
<xsd:extension base="operatorExpr">
<xsd:sequence>
<xsd:element name="firstOperand" type="exprWrapper"/>
<xsd:element name="secondOperand" type="exprWrapper"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="operatorExpr" type="operatorExpr" abstract="true" substitutionGroup="expr"/>
<xsd:element name="arithmeticOp" type="operatorExpr" abstract="true" substitutionGroup="operatorExpr"/>
<xsd:element name="addOp" type="binaryOperatorExpr" substitutionGroup="arithmeticOp"/>
<xsd:element name="subtractOp" type="binaryOperatorExpr" substitutionGroup="arithmeticOp"/>
<xsd:element name="multiplyOp" type="binaryOperatorExpr" substitutionGroup="arithmeticOp"/>
<xsd:element name="divOp" type="binaryOperatorExpr" substitutionGroup="arithmeticOp"/>
<xsd:element name="idivOp" type="binaryOperatorExpr" substitutionGroup="arithmeticOp"/>
<xsd:element name="modOp" type="binaryOperatorExpr" substitutionGroup="arithmeticOp"/>
<xsd:element name="unaryMinusOp" type="unaryOperatorExpr" substitutionGroup="arithmeticOp"/>
<xsd:element name="unaryPlusOp" type="unaryOperatorExpr" substitutionGroup="arithmeticOp"/>
<xsd:element name="comparisonOp" type="binaryOperatorExpr" abstract="true"
substitutionGroup="operatorExpr"/>
<xsd:element name="valueComparisonOp" type="binaryOperatorExpr" abstract="true"
substitutionGroup="operatorExpr"/>
<xsd:element name="eqOp" type="binaryOperatorExpr" substitutionGroup="valueComparisonOp"/>
<xsd:element name="neOp" type="binaryOperatorExpr" substitutionGroup="valueComparisonOp"/>
<xsd:element name="gtOp" type="binaryOperatorExpr" substitutionGroup="valueComparisonOp"/>
<xsd:element name="geOp" type="binaryOperatorExpr" substitutionGroup="valueComparisonOp"/>
<xsd:element name="ltOp" type="binaryOperatorExpr" substitutionGroup="valueComparisonOp"/>
<xsd:element name="leOp" type="binaryOperatorExpr" substitutionGroup="valueComparisonOp"/>
<xsd:element name="generalComparisonOp" type="binaryOperatorExpr" abstract="true"
substitutionGroup="operatorExpr"/>
<xsd:element name="equalOp" type="binaryOperatorExpr" substitutionGroup="generalComparisonOp"/>
<xsd:element name="notEqualOp" type="binaryOperatorExpr" substitutionGroup="generalComparisonOp"/>
<xsd:element name="lessThanOp" type="binaryOperatorExpr" substitutionGroup="generalComparisonOp"/>
<xsd:element name="lessThanOrEqualOp" type="binaryOperatorExpr"
substitutionGroup="generalComparisonOp"/>
<xsd:element name="greaterThanOp" type="binaryOperatorExpr" substitutionGroup="generalComparisonOp"/>
<xsd:element name="greaterThanOrEqualOp" type="binaryOperatorExpr"
substitutionGroup="generalComparisonOp"/>
<xsd:element name="nodeComparisonOp" type="binaryOperatorExpr" abstract="true"
substitutionGroup="operatorExpr"/>
<xsd:element name="isOp" type="binaryOperatorExpr" substitutionGroup="nodeComparisonOp"/>
<xsd:element name="orderComparisonOp" type="binaryOperatorExpr" abstract="true"
substitutionGroup="operatorExpr"/>
<xsd:element name="nodeBeforeOp" type="binaryOperatorExpr" substitutionGroup="orderComparisonOp"/>
<xsd:element name="nodeAfterOp" type="binaryOperatorExpr" substitutionGroup="orderComparisonOp"/>
<xsd:element name="logicalOp" type="binaryOperatorExpr" abstract="true"
substitutionGroup="operatorExpr"/>
<xsd:element name="andOp" type="binaryOperatorExpr" substitutionGroup="logicalOp"/>
<xsd:element name="orOp" type="binaryOperatorExpr" substitutionGroup="logicalOp"/>
<xsd:element name="setOp" type="binaryOperatorExpr" abstract="true" substitutionGroup="operatorExpr"/>
<xsd:element name="unionOp" type="binaryOperatorExpr" substitutionGroup="setOp"/>
<xsd:element name="intersectOp" type="binaryOperatorExpr" substitutionGroup="setOp"/>
<xsd:element name="exceptOp" type="binaryOperatorExpr" substitutionGroup="setOp"/>
<!-- Basic typenames -->
<xsd:element name="atomicType" type="QName" substitutionGroup="itemType"/>
<!-- Used in castable expression -->
<xsd:element name="singleType">
<xsd:complexType>
<xsd:sequence>
<xsd:element ref="atomicType"/>
<xsd:element name="optional" type="emptyContent" minOccurs="0"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="itemType" abstract="true"/>
<xsd:complexType name="emptyItemTypeContent"/>
<xsd:element name="anyItemType" type="emptyItemTypeContent" substitutionGroup="itemType"/>
<xsd:simpleType name="occurrenceIndicator">
<xsd:restriction base="xsd:string">
<xsd:enumeration value="?"/>
<xsd:enumeration value="*"/>
<xsd:enumeration value="+"/>
</xsd:restriction>
</xsd:simpleType>
<xsd:complexType name="sequenceType">
<xsd:choice>
<xsd:element name="voidSequenceType" type="emptyContent"/>
<xsd:sequence>
<xsd:element ref="itemType"/>
<xsd:element name="occurrenceIndicator" type="occurrenceIndicator" minOccurs="0"/>
</xsd:sequence>
</xsd:choice>
</xsd:complexType>
<xsd:element name="sequenceType" type="sequenceType"/>
<xsd:element name="typeDeclaration" type="sequenceType"/>
<!-- Represents a "typed" variable (for clause, let clause etc) -->
<xsd:element name="typedVariableBinding">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="varName" type="QName"/>
<xsd:element ref="typeDeclaration" minOccurs="0"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<!-- Represents an untyped variable for the "at" clause in a for clause -->
<xsd:element name="positionalVariableBinding" type="QName"/>
<!-- substitutionGroup="FLWORVariableBindings"/> -->
<xsd:element name="variableBinding" type="QName"/>
<!-- Represents all variable bindings in a for or let clause except typed and positional variable bindings -->
<xsd:element name="forLetClauseItemExtensions" abstract="true"/>
<xsd:complexType name="forClauseItem">
<xsd:sequence>
<xsd:element ref="typedVariableBinding"/>
<xsd:element ref="positionalVariableBinding" minOccurs="0" maxOccurs="1"/>
<xsd:element ref="forLetClauseItemExtensions" minOccurs="0" maxOccurs="unbounded"/>
<xsd:element name="forExpr" type="exprWrapper"/>
</xsd:sequence>
</xsd:complexType>
<xsd:element name="forClauseItem" type="forClauseItem"/>
<xsd:element name="forClause">
<xsd:complexType>
<xsd:sequence>
<xsd:element ref="forClauseItem" minOccurs="1" maxOccurs="unbounded"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="letClauseItem">
<xsd:complexType>
<xsd:sequence>
<xsd:choice>
<xsd:sequence>
<xsd:element ref="typedVariableBinding"/>
<xsd:element ref="forLetClauseItemExtensions" minOccurs="0" maxOccurs="unbounded"/>
</xsd:sequence>
<xsd:element ref="forLetClauseItemExtensions" minOccurs="0" maxOccurs="unbounded"/>
</xsd:choice>
<xsd:element name="letExpr" type="exprWrapper"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="letClause">
<xsd:complexType>
<xsd:sequence>
<xsd:element ref="letClauseItem" maxOccurs="unbounded"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="whereClause" type="exprWrapper"/>
<xsd:element name="returnClause" type="exprWrapper"/>
<xsd:simpleType name="emptyOrderingMode">
<xsd:restriction base="xsd:string">
<xsd:enumeration value="empty greatest"/>
<xsd:enumeration value="empty least"/>
</xsd:restriction>
</xsd:simpleType>
<xsd:simpleType name="orderingKind">
<xsd:restriction base="xsd:string">
<xsd:enumeration value="ascending"/>
<xsd:enumeration value="descending"/>
</xsd:restriction>
</xsd:simpleType>
<xsd:element name="orderModifier">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="orderingKind" type="orderingKind" minOccurs="0"/>
<xsd:element name="emptyOrderingMode" type="emptyOrderingMode" minOccurs="0"/>
<xsd:element name="collation" type="xsd:string" minOccurs="0"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="orderBySpec">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="orderByExpr" type="exprWrapper"/>
<xsd:element ref="orderModifier" minOccurs="0"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="orderByClause">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="stable" type="emptyContent" minOccurs="0"/>
<xsd:element ref="orderBySpec" maxOccurs="unbounded"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<!-- This is the flwor expression -->
<xsd:complexType name="flworExpr">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:choice maxOccurs="unbounded">
<xsd:element ref="forClause"/>
<xsd:element ref="letClause"/>
</xsd:choice>
<xsd:element ref="whereClause" minOccurs="0"/>
<xsd:element ref="orderByClause" minOccurs="0"/>
<xsd:element ref="returnClause"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="flworExpr" type="flworExpr" substitutionGroup="expr"/>
<!-- conditional expressions -->
<xsd:complexType name="ifThenElseExpr">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element name="ifClause" type="exprWrapper"/>
<xsd:element name="thenClause" type="exprWrapper"/>
<xsd:element name="elseClause" type="exprWrapper"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="ifThenElseExpr" type="ifThenElseExpr" substitutionGroup="expr"/>
<!-- The following clauses describe quantified expressions -->
<xsd:simpleType name="quantifier">
<xsd:restriction base="xsd:NMTOKEN">
<xsd:enumeration value="some"/>
<xsd:enumeration value="every"/>
</xsd:restriction>
</xsd:simpleType>
<xsd:element name="quantifiedExprInClause">
<xsd:complexType>
<xsd:sequence>
<xsd:element ref="typedVariableBinding"/>
<xsd:element name="sourceExpr" type="exprWrapper"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:complexType name="quantifiedExpr">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element name="quantifier" type="quantifier"/>
<xsd:element ref="quantifiedExprInClause" maxOccurs="unbounded"/>
<xsd:element name="predicateExpr" type="exprWrapper"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="quantifiedExpr" type="quantifiedExpr" substitutionGroup="expr"/>
<!-- handle the typeswitch construct -->
<!-- Note: no substitutionGroup as we cannot use this anywhere -->
<xsd:element name="typeswitchExprCaseClause">
<xsd:complexType>
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element ref="variableBinding" minOccurs="0"/>
<xsd:element ref="sequenceType"/>
<xsd:element name="resultExpr" type="exprWrapper"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
</xsd:element>
<!-- Note: no substitutionGroup as we cannot use this anywhere -->
<xsd:element name="typeswitchExprDefaultClause">
<xsd:complexType>
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element ref="variableBinding" minOccurs="0"/>
<xsd:element name="resultExpr" type="exprWrapper"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
</xsd:element>
<xsd:complexType name="typeswitchExpr">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element name="argExpr" type="exprWrapper"/>
<xsd:element ref="typeswitchExprCaseClause" maxOccurs="unbounded"/>
<xsd:element ref="typeswitchExprDefaultClause"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="typeswitchExpr" type="typeswitchExpr" substitutionGroup="expr"/>
<!-- instance-of expressions -->
<xsd:complexType name="instanceOfExpr">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element name="argExpr" type="exprWrapper"/>
<xsd:element ref="sequenceType"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="instanceOfExpr" type="instanceOfExpr" substitutionGroup="expr"/>
<!-- treat-as expressions -->
<xsd:complexType name="treatExpr">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element name="argExpr" type="exprWrapper"/>
<xsd:element ref="sequenceType"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="treatExpr" type="treatExpr" substitutionGroup="expr"/>
<!-- castable and cast expressions -->
<xsd:complexType name="castableExpr">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element name="argExpr" type="exprWrapper"/>
<xsd:element ref="singleType"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="castableExpr" type="castableExpr" substitutionGroup="expr"/>
<xsd:complexType name="castExpr">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element name="argExpr" type="exprWrapper"/>
<xsd:element ref="singleType"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="castExpr" type="castExpr" substitutionGroup="expr"/>
<!-- Validate expressions -->
<xsd:simpleType name="validationMode">
<xsd:restriction base="xsd:NMTOKEN">
<xsd:enumeration value="lax"/>
<xsd:enumeration value="strict"/>
</xsd:restriction>
</xsd:simpleType>
<xsd:complexType name="validateExpr">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element name="validationMode" type="validationMode" minOccurs="0"/>
<xsd:element name="argExpr" type="exprWrapper"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="validateExpr" type="validateExpr" substitutionGroup="expr"/>
<!-- Direct constructors. Only elementConstructor for now -->
<!-- Note the absence of constructors corresponding to
the directCommentConstructor and the directPIConstructor
productions in the XQuery grammar. This is because they are
trivially identical to the computed variants
-->
<!-- attributeConstructor is no longer a subclass of expr -->
<xsd:complexType name="attributeConstructor">
<xsd:sequence>
<xsd:element name="attributeName" type="QName"/>
<xsd:choice>
<xsd:element name="attributeValueExpr" type="exprList"/>
<xsd:element name="attributeValue" type="xsd:string"/>
</xsd:choice>
</xsd:sequence>
</xsd:complexType>
<xsd:complexType name="namespaceDeclaration">
<xsd:sequence>
<xsd:element name="prefix" type="xsd:NCName" minOccurs="0"/>
<xsd:element name="uri" type="xsd:string"/>
</xsd:sequence>
</xsd:complexType>
<xsd:element name="attributeList">
<xsd:complexType>
<xsd:sequence>
<xsd:choice maxOccurs="unbounded">
<xsd:element name="attributeConstructor" type="attributeConstructor"/>
<xsd:element name="namespaceDeclaration" type="namespaceDeclaration"/>
</xsd:choice>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="elementContent" type="exprList"/>
<xsd:complexType name="elementConstructor">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element name="tagName" type="QName"/>
<xsd:element ref="attributeList" minOccurs="0"/>
<xsd:element ref="elementContent" minOccurs="0"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="elementConstructor" type="elementConstructor" substitutionGroup="expr"/>
<!-- computed constructors -->
<xsd:complexType name="computedElementConstructor">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:choice>
<xsd:element name="tagName" type="QName"/>
<xsd:element name="tagNameExpr" type="exprWrapper"/>
</xsd:choice>
<xsd:element name="contentExpr" type="exprWrapper" minOccurs="0"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="computedElementConstructor" type="computedElementConstructor"
substitutionGroup="expr"/>
<xsd:complexType name="computedAttributeConstructor">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:choice>
<xsd:element name="tagName" type="QName"/>
<xsd:element name="tagNameExpr" type="exprWrapper"/>
</xsd:choice>
<xsd:element name="valueExpr" type="exprWrapper" minOccurs="0"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="computedAttributeConstructor" type="computedAttributeConstructor"
substitutionGroup="expr"/>
<xsd:complexType name="computedDocumentConstructor">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element name="argExpr" type="exprWrapper"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="computedDocumentConstructor" type="computedDocumentConstructor"
substitutionGroup="expr"/>
<xsd:complexType name="computedTextConstructor">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element name="argExpr" type="exprWrapper" minOccurs="0"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="computedTextConstructor" type="computedTextConstructor" substitutionGroup="expr"/>
<xsd:complexType name="computedCommentConstructor">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element name="argExpr" type="exprWrapper"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="computedCommentConstructor" type="computedCommentConstructor"
substitutionGroup="expr"/>
<xsd:complexType name="computedPIConstructor">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:choice>
<xsd:element name="piTarget" type="xsd:NCName"/>
<xsd:element name="piTargetExpr" type="exprWrapper"/>
</xsd:choice>
<xsd:element name="piValueExpr" type="exprWrapper" minOccurs="0"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="computedPIConstructor" type="computedPIConstructor" substitutionGroup="expr"/>
<!-- ordered and unordered expressions -->
<xsd:complexType name="unorderedExpr">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element name="argExpr" type="exprWrapper"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="unorderedExpr" type="unorderedExpr" substitutionGroup="expr"/>
<xsd:complexType name="orderedExpr">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:sequence>
<xsd:element name="argExpr" type="exprWrapper"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="orderedExpr" type="orderedExpr" substitutionGroup="expr"/>
<xsd:complexType name="simpleWildcard">
<xsd:choice>
<xsd:element name="QName" type="QName"/>
<xsd:element name="star" type="emptyContent"/>
</xsd:choice>
</xsd:complexType>
<xsd:element name="Wildcard">
<xsd:complexType>
<xsd:all>
<xsd:element name="star" type="emptyContent" minOccurs="0"/>
<xsd:element ref="NCName" minOccurs="0"/>
</xsd:all>
</xsd:complexType>
</xsd:element>
<xsd:element name="schemaAttributeTest" type="QName" substitutionGroup="kindTest"/>
<xsd:element name="attributeTest" substitutionGroup="kindTest">
<xsd:complexType>
<xsd:complexContent>
<xsd:extension base="emptyItemTypeContent">
<xsd:sequence minOccurs="0">
<xsd:element name="attributeName" type="simpleWildcard"/>
<xsd:element name="typeName" type="QName" minOccurs="0"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
</xsd:element>
<xsd:element name="anyElementTest" abstract="true" substitutionGroup="kindTest"/>
<xsd:element name="schemaElementTest" type="QName" substitutionGroup="anyElementTest"/>
<xsd:element name="elementTest" substitutionGroup="anyElementTest">
<xsd:complexType>
<xsd:complexContent>
<xsd:extension base="emptyItemTypeContent">
<xsd:sequence minOccurs="0">
<xsd:element name="elementName" type="simpleWildcard"/>
<xsd:sequence minOccurs="0">
<xsd:element name="typeName" type="QName"/>
<xsd:element name="nillable" type="emptyContent" minOccurs="0"/>
</xsd:sequence>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
</xsd:element>
<xsd:element name="documentTest" substitutionGroup="kindTest">
<xsd:complexType>
<xsd:complexContent>
<xsd:extension base="emptyItemTypeContent">
<xsd:sequence>
<xsd:element ref="anyElementTest" minOccurs="0"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
</xsd:element>
<xsd:element name="piTest" substitutionGroup="kindTest">
<xsd:complexType>
<xsd:complexContent>
<xsd:extension base="emptyItemTypeContent">
<xsd:sequence>
<xsd:element name="piTarget" type="xsd:NCName" minOccurs="0"/>
</xsd:sequence>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
</xsd:element>
<xsd:element name="nameTest" type="QName"/>
<xsd:element name="kindTest" substitutionGroup="itemType"/>
<xsd:element name="textTest" type="emptyItemTypeContent" substitutionGroup="kindTest"/>
<xsd:element name="commentTest" type="emptyItemTypeContent" substitutionGroup="kindTest"/>
<xsd:element name="anyKindTest" type="emptyItemTypeContent" substitutionGroup="kindTest"/>
<xsd:element name="xpathAxis">
<xsd:simpleType>
<xsd:restriction base="xsd:NMTOKEN">
<xsd:enumeration value="child"/>
<xsd:enumeration value="attribute"/>
<xsd:enumeration value="self"/>
<xsd:enumeration value="parent"/>
<xsd:enumeration value="descendant-or-self"/>
<xsd:enumeration value="descendant"/>
<xsd:enumeration value="following"/>
<xsd:enumeration value="following-sibling"/>
<xsd:enumeration value="ancestor"/>
<xsd:enumeration value="ancestor-or-self"/>
<xsd:enumeration value="preceding"/>
<xsd:enumeration value="preceding-sibling"/>
</xsd:restriction>
</xsd:simpleType>
</xsd:element>
<!-- xqx:parenthesizedExpr deemed not useful; removed.
<xsd:element name="parenthesizedExpr" type="exprWrapperOptional"/>
-->
<xsd:group name="filterExpr">
<xsd:choice>
<xsd:element ref="constantExpr"/>
<xsd:element ref="varRef"/>
<xsd:element ref="contextItemExpr"/>
<xsd:element ref="functionCallExpr"/>
<!-- xqx:parenthesizedExpr deemed not useful; replaced with xqx:sequenceExpr. -->
<xsd:element ref="sequenceExpr"/>
<xsd:element ref="elementConstructor"/>
<xsd:element ref="computedElementConstructor"/>
<xsd:element ref="computedAttributeConstructor"/>
<xsd:element ref="computedDocumentConstructor"/>
<xsd:element ref="computedTextConstructor"/>
<xsd:element ref="computedCommentConstructor"/>
<xsd:element ref="computedPIConstructor"/>
<xsd:element ref="orderedExpr"/>
<xsd:element ref="unorderedExpr"/>
</xsd:choice>
</xsd:group>
<!-- removed nameTest and Wildcard outer choices per Bugzilla Bug #2523 -->
<xsd:element name="stepExpr">
<xsd:complexType>
<xsd:sequence>
<xsd:choice>
<xsd:sequence>
<xsd:element ref="xpathAxis"/>
<xsd:choice>
<xsd:element ref="kindTest"/>
<xsd:element ref="nameTest"/>
<xsd:element ref="Wildcard"/>
</xsd:choice>
</xsd:sequence>
<xsd:element name="filterExpr">
<xsd:complexType>
<xsd:sequence>
<xsd:group ref="filterExpr"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
</xsd:choice>
<xsd:element name="predicates" type="exprList" minOccurs="0"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<!-- rewrote pathExpr definition per Bugzilla Bug #2523 -->
<xsd:complexType name="pathExpr">
<xsd:complexContent>
<xsd:extension base="expr">
<xsd:choice>
<xsd:sequence>
<xsd:element name="rootExpr" type="emptyContent"/>
<xsd:element ref="stepExpr" minOccurs="0" maxOccurs="unbounded"/>
</xsd:sequence>
<xsd:element ref="stepExpr" maxOccurs="unbounded"/>
</xsd:choice>
</xsd:extension>
</xsd:complexContent>
</xsd:complexType>
<xsd:element name="pathExpr" type="pathExpr" substitutionGroup="expr"/>
<!-- The following constructs deal with the query prolog -->
<xsd:element name="module">
<xsd:complexType>
<xsd:sequence>
<xsd:element ref="versionDecl" minOccurs="0"/>
<xsd:choice>
<xsd:element ref="mainModule"/>
<xsd:element ref="libraryModule"/>
</xsd:choice>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="mainModule">
<xsd:complexType>
<xsd:sequence>
<xsd:element ref="prolog" minOccurs="0"/>
<xsd:element name="queryBody" type="exprWrapper"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="libraryModule">
<xsd:complexType>
<xsd:sequence>
<xsd:element ref="moduleDecl"/>
<xsd:element ref="prolog" minOccurs="0"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="versionDecl">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="version" type="xsd:string"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="prolog">
<xsd:complexType>
<xsd:sequence>
<xsd:element ref="prologPartOneItem" minOccurs="0" maxOccurs="unbounded"/>
<xsd:element ref="prologPartTwoItem" minOccurs="0" maxOccurs="unbounded"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="prologPartOneItem" abstract="true"/>
<xsd:element name="prologPartTwoItem" abstract="true"/>
<xsd:element name="defaultCollationDecl" type="xsd:string"
substitutionGroup="prologPartOneItem"/>
<xsd:element name="baseUriDecl" type="xsd:string"
substitutionGroup="prologPartOneItem"/>
<xsd:element name="constructionDecl" substitutionGroup="prologPartOneItem">
<xsd:simpleType>
<xsd:restriction base="xsd:NMTOKEN">
<xsd:enumeration value="strip"/>
<xsd:enumeration value="preserve"/>
</xsd:restriction>
</xsd:simpleType>
</xsd:element>
<xsd:element name="orderingModeDecl" substitutionGroup="prologPartOneItem">
<xsd:simpleType>
<xsd:restriction base="xsd:NMTOKEN">
<xsd:enumeration value="ordered"/>
<xsd:enumeration value="unordered"/>
</xsd:restriction>
</xsd:simpleType>
</xsd:element>
<xsd:element name="emptyOrderingDecl" type="emptyOrderingMode"
substitutionGroup="prologPartOneItem"/>
<xsd:element name="copyNamespacesDecl" substitutionGroup="prologPartOneItem">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="preserveMode">
<xsd:simpleType>
<xsd:restriction base="xsd:NMTOKEN">
<xsd:enumeration value="preserve"/>
<xsd:enumeration value="no-preserve"/>
</xsd:restriction>
</xsd:simpleType>
</xsd:element>
<xsd:element name="inheritMode">
<xsd:simpleType>
<xsd:restriction base="xsd:NMTOKEN">
<xsd:enumeration value="inherit"/>
<xsd:enumeration value="no-inherit"/>
</xsd:restriction>
</xsd:simpleType>
</xsd:element>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:simpleType name="defaultNamespaceCategory">
<xsd:restriction base="xsd:NMTOKEN">
<xsd:enumeration value="function"/>
<xsd:enumeration value="element"/>
</xsd:restriction>
</xsd:simpleType>
<xsd:element name="defaultNamespaceDecl" substitutionGroup="prologPartOneItem">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="defaultNamespaceCategory" type="defaultNamespaceCategory"/>
<xsd:element name="uri" type="xsd:string"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:complexType name="namespaceDeclType">
<xsd:sequence>
<xsd:element name="prefix" type="xsd:NCName"/>
<xsd:element name="uri" type="xsd:string"/>
</xsd:sequence>
</xsd:complexType>
<xsd:element name="namespaceDecl" type="namespaceDeclType"
substitutionGroup="prologPartOneItem"/>
<xsd:element name="moduleDecl" type="namespaceDeclType"/>
<xsd:element name="schemaImport" substitutionGroup="prologPartOneItem">
<xsd:complexType>
<xsd:sequence>
<xsd:choice minOccurs="0">
<xsd:element name="namespacePrefix" type="xsd:NCName"/>
<xsd:element name="defaultElementNamespace" type="emptyContent"/>
</xsd:choice>
<xsd:element name="targetNamespace" type="xsd:string"/>
<xsd:element name="targetLocation" type="xsd:string" minOccurs="0" maxOccurs="unbounded"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="moduleImport" substitutionGroup="prologPartOneItem">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="namespacePrefix" type="xsd:NCName" minOccurs="0"/>
<xsd:element name="targetNamespace" type="xsd:string"/>
<xsd:element name="targetLocation" type="xsd:string" minOccurs="0" maxOccurs="unbounded"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="varDecl" substitutionGroup="prologPartTwoItem">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="varName" type="QName"/>
<xsd:element ref="typeDeclaration" minOccurs="0"/>
<xsd:choice>
<xsd:element name="varValue" type="exprWrapper"/>
<xsd:element name="external" type="emptyContent"/>
</xsd:choice>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="optionDecl" substitutionGroup="prologPartTwoItem">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="optionName" type="QName"/>
<xsd:element name="optionContents" type="xsd:string"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="functionDecl" substitutionGroup="prologPartTwoItem">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="functionName" type="QName"/>
<xsd:element ref="paramList"/>
<xsd:element ref="typeDeclaration" minOccurs="0"/>
<xsd:choice>
<xsd:element name="functionBody" type="exprWrapper"/>
<xsd:element name="externalDefinition" type="emptyContent"/>
</xsd:choice>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="param">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="varName" type="QName"/>
<xsd:element ref="typeDeclaration" minOccurs="0"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="paramList">
<xsd:complexType>
<xsd:sequence>
<xsd:element ref="param" minOccurs="0" maxOccurs="unbounded"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<!-- The element below handles the trivial XQuery embedding -->
<xsd:element name="xquery" type="xsd:string"/>
</xsd:schema>