Introduction
The 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.
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 .
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.
Mapping the XQuery Syntax
XQueryX is an XML representation of the abstract syntax found in
Appendix A of . The XQueryX syntax is defined by
the XQueryX Schema, which is specified in . The XQueryX semantics are
defined by a stylesheet that maps an instance of XQueryX to an instance of
XQuery; see .
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.
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 ,
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 ,
an XQueryX solution, and the XQuery that results from applying the XQueryX-to-XQuery transformation
defined by the stylesheet in 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 , 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 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.
Example 1
Here is Q1 from the , use case XMP
(Experiences and Exemplars): "List books published by Addison-Wesley after 1991,
including their year and title."
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>
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>
Transformation of XQueryX Solution into XQuery
Application of the stylesheet in
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>
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
Example 2
Here is Q4 from the , 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."
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>
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>
Transformation of XQueryX Solution into XQuery
Application of the stylesheet in
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>
Example 3
Here is Q7 from the , use case XMP
(Experiences and Exemplars): "List the titles and years of all books published by
Addison-Wesley after 1991, in alphabetic order."
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>
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>
Transformation of XQueryX Solution into XQuery
Application of the stylesheet in 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>
Example 4
Here is Q8 from the , use case NS
(Queries Using Namespaces):
"Select all traders (either seller or high bidder) without negative comments."
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>
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>
Transformation of XQueryX Solution into XQuery
Application of the stylesheet in
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>
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>
Conformance
This section defines the conformance criteria for an XQueryX processor
(see Figure 1, "Processing Model Overview", in ,
.
In this section, the following terms are used to indicate the
requirement levels defined in .
[Definition: MUST means that the item is an absolute requirement of the specification.]
[Definition: SHOULD means that there may exist valid reasons in particular
circumstances to ignore a particular item, but the full implications
must be understood and carefully weighed before choosing a different course.]
[Definition: MAY means that an item is truly optional.]
An XQueryX processor that claims to conform to this specification MUST
implement the XQueryX syntax as defined in of this
specification and include a claim of Minimal Conformance as defined in
, .
In addition to a claim of Minimal Conformance, it MAY claim conformance to
one or more optional features defined in
, .
References
S. Bradner.
Key Words for use in RFCs to Indicate Requirement Levels. IETF RFC 2119.
See http://www.ietf.org/rfc/rfc2119.txt.
M. Murata, S. St. Laurent, and D. Kohn.
XML Media Types IETF RFC 3023 or its successors.
See http://www.ietf.org/rfc/rfc3023.txt.
Transforming XQueryX to XQuery
The following stylesheet converts from XQueryX syntax to XML Query syntax.
Note the intent of the stylesheet is to produce a valid XQuery with the
same semantics (see ) as the input XQueryX.
<?xml version="1.0"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xqx="http://www.w3.org/2005/XQueryX">
<!-- Note that this stylesheet frequently invokes templates for
specified elements, even when there are no templates in the
stylesheet whose match="" attribute identifies those elements.
In such case, the default template's element matching template
is invoked, which merely invokes xsl:apply-templates -->
<xsl:output method="text"/>
<xsl:strip-space elements="*"/>
<xsl:preserve-space elements="xqx:value xqx:attributeValue xqx:pragmaContents
xqx:optionContents xqx:xquery"/>
<xsl:variable name="DOT" select="'.'"/>
<xsl:variable name="SPACE" select="' '"/>
<xsl:variable name="SLASH" select="'/'"/>
<xsl:variable name="SLASH_SLASH" select="'//'"/>
<xsl:variable name="LESSTHAN" select="'<'"/>
<xsl:variable name="GREATERTHAN" select="'>'"/>
<xsl:variable name="LPAREN" select="'('"/>
<xsl:variable name="RPAREN" select="')'"/>
<xsl:variable name="NEWLINE"><xsl:text>
</xsl:text></xsl:variable>
<xsl:variable name="COMMA" select="','"/>
<xsl:variable name="COMMA_SPACE" select="', '"/>
<xsl:variable name="COMMA_NEWLINE"><xsl:text>,
</xsl:text></xsl:variable>
<xsl:variable name="QUOTE"><xsl:text>'</xsl:text></xsl:variable>
<xsl:variable name="DOUBLEQUOTE"><xsl:text>"</xsl:text></xsl:variable>
<xsl:variable name="TO" select="' to '"/>
<xsl:variable name="LBRACE" select="'{'"/>
<xsl:variable name="RBRACE" select="'}'"/>
<xsl:variable name="LBRACKET" select="'['"/>
<xsl:variable name="RBRACKET" select="']'"/>
<xsl:variable name="DOLLAR" select="'$'"/>
<xsl:variable name="MINUS" select="'-'"/>
<xsl:variable name="PLUS" select="'+'"/>
<xsl:variable name="EQUAL" select="'='"/>