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LetExpression
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SUMMARY: NESTED | <A HREF="#fields_inherited_from_class_net.sf.saxon.expr.Assignation">FIELD</A> | <A HREF="#constructor_summary">CONSTR</A> | <A HREF="#method_summary">METHOD</A></FONT></TD>
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<FONT SIZE="-1">
net.sf.saxon.expr</FONT>
<BR>
Class LetExpression</H2>
<PRE>
<A HREF="http://download.oracle.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">java.lang.Object</A>
<IMG SRC="../../../../resources/inherit.gif" ALT="extended by "><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">net.sf.saxon.expr.Expression</A>
<IMG SRC="../../../../resources/inherit.gif" ALT="extended by "><A HREF="../../../../net/sf/saxon/expr/Assignation.html" title="class in net.sf.saxon.expr">net.sf.saxon.expr.Assignation</A>
<IMG SRC="../../../../resources/inherit.gif" ALT="extended by "><B>net.sf.saxon.expr.LetExpression</B>
</PRE>
<DL>
<DT><B>All Implemented Interfaces:</B> <DD><A HREF="http://download.oracle.com/javase/6/docs/api/java/io/Serializable.html?is-external=true" title="class or interface in java.io">Serializable</A>, <A HREF="http://download.oracle.com/javase/6/docs/api/javax/xml/transform/SourceLocator.html?is-external=true" title="class or interface in javax.xml.transform">SourceLocator</A>, <A HREF="../../../../net/sf/saxon/event/LocationProvider.html" title="interface in net.sf.saxon.event">LocationProvider</A>, <A HREF="../../../../net/sf/saxon/event/SaxonLocator.html" title="interface in net.sf.saxon.event">SaxonLocator</A>, <A HREF="../../../../net/sf/saxon/expr/Binding.html" title="interface in net.sf.saxon.expr">Binding</A>, <A HREF="../../../../net/sf/saxon/expr/instruct/TailCallReturner.html" title="interface in net.sf.saxon.expr.instruct">TailCallReturner</A>, <A HREF="../../../../net/sf/saxon/trace/InstructionInfo.html" title="interface in net.sf.saxon.trace">InstructionInfo</A>, <A HREF="http://download.oracle.com/javase/6/docs/api/org/xml/sax/Locator.html?is-external=true" title="class or interface in org.xml.sax">Locator</A></DD>
</DL>
<DL>
<DT><B>Direct Known Subclasses:</B> <DD><A HREF="../../../../net/sf/saxon/expr/EagerLetExpression.html" title="class in net.sf.saxon.expr">EagerLetExpression</A></DD>
</DL>
<HR>
<DL>
<DT><PRE>public class <B>LetExpression</B><DT>extends <A HREF="../../../../net/sf/saxon/expr/Assignation.html" title="class in net.sf.saxon.expr">Assignation</A><DT>implements <A HREF="../../../../net/sf/saxon/expr/instruct/TailCallReturner.html" title="interface in net.sf.saxon.expr.instruct">TailCallReturner</A></DL>
</PRE>
<P>
A LetExpression is modelled on the XQuery syntax let $x := expr return expr. This syntax
is not available in the surface XPath language, but it is used internally in an optimized
expression tree.
<P>
<P>
<DL>
<DT><B>See Also:</B><DD><A HREF="../../../../serialized-form.html#net.sf.saxon.expr.LetExpression">Serialized Form</A></DL>
<HR>
<P>
<!-- =========== FIELD SUMMARY =========== -->
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<A NAME="fields_inherited_from_class_net.sf.saxon.expr.Assignation"><!-- --></A>
<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
<TR BGCOLOR="#EEEEFF" CLASS="TableSubHeadingColor">
<TH ALIGN="left"><B>Fields inherited from class net.sf.saxon.expr.<A HREF="../../../../net/sf/saxon/expr/Assignation.html" title="class in net.sf.saxon.expr">Assignation</A></B></TH>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD><CODE><A HREF="../../../../net/sf/saxon/expr/Assignation.html#action">action</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#requiredType">requiredType</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#sequence">sequence</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#slotNumber">slotNumber</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#variableName">variableName</A></CODE></TD>
</TR>
</TABLE>
<A NAME="fields_inherited_from_class_net.sf.saxon.expr.Expression"><!-- --></A>
<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
<TR BGCOLOR="#EEEEFF" CLASS="TableSubHeadingColor">
<TH ALIGN="left"><B>Fields inherited from class net.sf.saxon.expr.<A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></B></TH>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#EFFECTIVE_BOOLEAN_VALUE">EFFECTIVE_BOOLEAN_VALUE</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#EVALUATE_METHOD">EVALUATE_METHOD</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#EVENT_FEED_METHOD">EVENT_FEED_METHOD</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#ITEM_FEED_METHOD">ITEM_FEED_METHOD</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#ITERATE_METHOD">ITERATE_METHOD</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#locationId">locationId</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#MAX_SEQUENCE_LENGTH">MAX_SEQUENCE_LENGTH</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#MAX_STRING_LENGTH">MAX_STRING_LENGTH</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#PROCESS_METHOD">PROCESS_METHOD</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#PUSH_SELECTION">PUSH_SELECTION</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#staticProperties">staticProperties</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#UNBOUNDED_LOWER">UNBOUNDED_LOWER</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#UNBOUNDED_UPPER">UNBOUNDED_UPPER</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#WATCH_METHOD">WATCH_METHOD</A></CODE></TD>
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<!-- ======== CONSTRUCTOR SUMMARY ======== -->
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<B>Constructor Summary</B></FONT></TH>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#LetExpression()">LetExpression</A></B>()</CODE>
<BR>
Create a LetExpression</TD>
</TR>
</TABLE>
<!-- ========== METHOD SUMMARY =========== -->
<A NAME="method_summary"><!-- --></A>
<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
<TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor">
<TH ALIGN="left" COLSPAN="2"><FONT SIZE="+2">
<B>Method Summary</B></FONT></TH>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> void</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#checkPermittedContents(net.sf.saxon.type.SchemaType, net.sf.saxon.expr.StaticContext, boolean)">checkPermittedContents</A></B>(<A HREF="../../../../net/sf/saxon/type/SchemaType.html" title="interface in net.sf.saxon.type">SchemaType</A> parentType,
<A HREF="../../../../net/sf/saxon/expr/StaticContext.html" title="interface in net.sf.saxon.expr">StaticContext</A> env,
boolean whole)</CODE>
<BR>
Check that any elements and attributes constructed or returned by this expression are acceptable
in the content model of a given complex type.</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> int</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#computeCardinality()">computeCardinality</A></B>()</CODE>
<BR>
Determine the static cardinality of the expression</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> int</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#computeSpecialProperties()">computeSpecialProperties</A></B>()</CODE>
<BR>
Get the static properties of this expression (other than its type).</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> <A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#copy()">copy</A></B>()</CODE>
<BR>
Copy an expression.</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> boolean</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#effectiveBooleanValue(net.sf.saxon.expr.XPathContext)">effectiveBooleanValue</A></B>(<A HREF="../../../../net/sf/saxon/expr/XPathContext.html" title="interface in net.sf.saxon.expr">XPathContext</A> context)</CODE>
<BR>
Get the effective boolean value of the expression.</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> <A HREF="../../../../net/sf/saxon/om/ValueRepresentation.html" title="interface in net.sf.saxon.om">ValueRepresentation</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#eval(net.sf.saxon.expr.XPathContext)">eval</A></B>(<A HREF="../../../../net/sf/saxon/expr/XPathContext.html" title="interface in net.sf.saxon.expr">XPathContext</A> context)</CODE>
<BR>
Evaluate the variable.</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> <A HREF="../../../../net/sf/saxon/om/Item.html" title="interface in net.sf.saxon.om">Item</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#evaluateItem(net.sf.saxon.expr.XPathContext)">evaluateItem</A></B>(<A HREF="../../../../net/sf/saxon/expr/XPathContext.html" title="interface in net.sf.saxon.expr">XPathContext</A> context)</CODE>
<BR>
Evaluate the expression as a singleton</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> void</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#evaluatePendingUpdates(net.sf.saxon.expr.XPathContext, net.sf.saxon.expr.PendingUpdateList)">evaluatePendingUpdates</A></B>(<A HREF="../../../../net/sf/saxon/expr/XPathContext.html" title="interface in net.sf.saxon.expr">XPathContext</A> context,
<A HREF="../../../../net/sf/saxon/expr/PendingUpdateList.html" title="interface in net.sf.saxon.expr">PendingUpdateList</A> pul)</CODE>
<BR>
Evaluate an updating expression, adding the results to a Pending Update List.</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> void</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#explain(net.sf.saxon.trace.ExpressionPresenter)">explain</A></B>(<A HREF="../../../../net/sf/saxon/trace/ExpressionPresenter.html" title="class in net.sf.saxon.trace">ExpressionPresenter</A> out)</CODE>
<BR>
Diagnostic print of expression structure.</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> int</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#getEvaluationMode()">getEvaluationMode</A></B>()</CODE>
<BR>
</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> <A HREF="http://download.oracle.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#getExpressionName()">getExpressionName</A></B>()</CODE>
<BR>
Get a name identifying the kind of expression, in terms meaningful to a user.</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> <A HREF="../../../../net/sf/saxon/value/IntegerValue.html" title="class in net.sf.saxon.value">IntegerValue</A>[]</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#getIntegerBounds()">getIntegerBounds</A></B>()</CODE>
<BR>
For an expression that returns an integer or a sequence of integers, get
a lower and upper bound on the values of the integers that may be returned, from
static analysis.</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> <A HREF="../../../../net/sf/saxon/type/ItemType.html" title="interface in net.sf.saxon.type">ItemType</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#getItemType(net.sf.saxon.type.TypeHierarchy)">getItemType</A></B>(<A HREF="../../../../net/sf/saxon/type/TypeHierarchy.html" title="class in net.sf.saxon.type">TypeHierarchy</A> th)</CODE>
<BR>
Determine the data type of the items returned by the expression, if possible</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> boolean</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#implementsStaticTypeCheck()">implementsStaticTypeCheck</A></B>()</CODE>
<BR>
Determine whether this expression implements its own method for static type checking</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> boolean</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#isVacuousExpression()">isVacuousExpression</A></B>()</CODE>
<BR>
Determine whether this is a vacuous expression as defined in the XQuery update specification</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> <A HREF="../../../../net/sf/saxon/om/SequenceIterator.html" title="interface in net.sf.saxon.om">SequenceIterator</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#iterate(net.sf.saxon.expr.XPathContext)">iterate</A></B>(<A HREF="../../../../net/sf/saxon/expr/XPathContext.html" title="interface in net.sf.saxon.expr">XPathContext</A> context)</CODE>
<BR>
Iterate over the result of the expression to return a sequence of items</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> <A HREF="../../../../net/sf/saxon/evpull/EventIterator.html" title="interface in net.sf.saxon.evpull">EventIterator</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#iterateEvents(net.sf.saxon.expr.XPathContext)">iterateEvents</A></B>(<A HREF="../../../../net/sf/saxon/expr/XPathContext.html" title="interface in net.sf.saxon.expr">XPathContext</A> context)</CODE>
<BR>
Iterate over the result of the expression to return a sequence of events</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> int</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#markTailFunctionCalls(net.sf.saxon.om.StructuredQName, int)">markTailFunctionCalls</A></B>(<A HREF="../../../../net/sf/saxon/om/StructuredQName.html" title="class in net.sf.saxon.om">StructuredQName</A> qName,
int arity)</CODE>
<BR>
Mark tail function calls</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> <A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#optimize(net.sf.saxon.expr.parser.ExpressionVisitor, net.sf.saxon.expr.parser.ExpressionVisitor.ContextItemType)">optimize</A></B>(<A HREF="../../../../net/sf/saxon/expr/parser/ExpressionVisitor.html" title="class in net.sf.saxon.expr.parser">ExpressionVisitor</A> visitor,
<A HREF="../../../../net/sf/saxon/expr/parser/ExpressionVisitor.ContextItemType.html" title="class in net.sf.saxon.expr.parser">ExpressionVisitor.ContextItemType</A> contextItemType)</CODE>
<BR>
Perform optimisation of an expression and its subexpressions.</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> void</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#process(net.sf.saxon.expr.XPathContext)">process</A></B>(<A HREF="../../../../net/sf/saxon/expr/XPathContext.html" title="interface in net.sf.saxon.expr">XPathContext</A> context)</CODE>
<BR>
Process this expression as an instruction, writing results to the current
outputter</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> <A HREF="../../../../net/sf/saxon/expr/instruct/TailCall.html" title="interface in net.sf.saxon.expr.instruct">TailCall</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#processLeavingTail(net.sf.saxon.expr.XPathContext)">processLeavingTail</A></B>(<A HREF="../../../../net/sf/saxon/expr/XPathContext.html" title="interface in net.sf.saxon.expr">XPathContext</A> context)</CODE>
<BR>
ProcessLeavingTail: called to do the real work of this instruction.</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> <A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#promote(net.sf.saxon.expr.parser.PromotionOffer, net.sf.saxon.expr.Expression)">promote</A></B>(<A HREF="../../../../net/sf/saxon/expr/parser/PromotionOffer.html" title="class in net.sf.saxon.expr.parser">PromotionOffer</A> offer,
<A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A> parent)</CODE>
<BR>
Promote this expression if possible</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> void</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#setEvaluationMode(int)">setEvaluationMode</A></B>(int evaluationMode)</CODE>
<BR>
</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> void</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#setRefCount(int)">setRefCount</A></B>(int refCount)</CODE>
<BR>
</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> <A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#staticTypeCheck(net.sf.saxon.value.SequenceType, boolean, net.sf.saxon.expr.parser.RoleLocator, net.sf.saxon.TypeCheckerEnvironment)">staticTypeCheck</A></B>(<A HREF="../../../../net/sf/saxon/value/SequenceType.html" title="class in net.sf.saxon.value">SequenceType</A> req,
boolean backwardsCompatible,
<A HREF="../../../../net/sf/saxon/expr/parser/RoleLocator.html" title="class in net.sf.saxon.expr.parser">RoleLocator</A> role,
<A HREF="../../../../net/sf/saxon/TypeCheckerEnvironment.html" title="interface in net.sf.saxon">TypeCheckerEnvironment</A> visitor)</CODE>
<BR>
Static type checking for let expressions is delegated to the expression itself,
and is performed on the "action" expression, to allow further delegation to the branches
of a conditional</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> <A HREF="http://download.oracle.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#toString()">toString</A></B>()</CODE>
<BR>
The toString() method for an expression attempts to give a representation of the expression
in an XPath-like form, but there is no guarantee that the syntax will actually be true XPath.</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> <A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../net/sf/saxon/expr/LetExpression.html#typeCheck(net.sf.saxon.expr.parser.ExpressionVisitor, net.sf.saxon.expr.parser.ExpressionVisitor.ContextItemType)">typeCheck</A></B>(<A HREF="../../../../net/sf/saxon/expr/parser/ExpressionVisitor.html" title="class in net.sf.saxon.expr.parser">ExpressionVisitor</A> visitor,
<A HREF="../../../../net/sf/saxon/expr/parser/ExpressionVisitor.ContextItemType.html" title="class in net.sf.saxon.expr.parser">ExpressionVisitor.ContextItemType</A> contextItemType)</CODE>
<BR>
Type-check the expression.</TD>
</TR>
</TABLE>
<A NAME="methods_inherited_from_class_net.sf.saxon.expr.Assignation"><!-- --></A>
<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
<TR BGCOLOR="#EEEEFF" CLASS="TableSubHeadingColor">
<TH ALIGN="left"><B>Methods inherited from class net.sf.saxon.expr.<A HREF="../../../../net/sf/saxon/expr/Assignation.html" title="class in net.sf.saxon.expr">Assignation</A></B></TH>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD><CODE><A HREF="../../../../net/sf/saxon/expr/Assignation.html#addReference(boolean)">addReference</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#addToPathMap(net.sf.saxon.expr.parser.PathMap, net.sf.saxon.expr.parser.PathMap.PathMapNodeSet)">addToPathMap</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#checkForUpdatingSubexpressions()">checkForUpdatingSubexpressions</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#evaluateVariable(net.sf.saxon.expr.XPathContext)">evaluateVariable</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#extendBindingList(net.sf.saxon.expr.Binding[])">extendBindingList</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#getAction()">getAction</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#getIntegerBoundsForVariable()">getIntegerBoundsForVariable</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#getLocalSlotNumber()">getLocalSlotNumber</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#getNominalReferenceCount()">getNominalReferenceCount</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#getObjectName()">getObjectName</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#getRequiredSlots()">getRequiredSlots</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#getRequiredType()">getRequiredType</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#getSequence()">getSequence</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#getVariableName()">getVariableName</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#getVariableQName()">getVariableQName</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#hasVariableBinding(net.sf.saxon.expr.Binding)">hasVariableBinding</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#isAssignable()">isAssignable</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#isGlobal()">isGlobal</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#isIndexedVariable()">isIndexedVariable</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#isUpdatingExpression()">isUpdatingExpression</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#iterateSubExpressions()">iterateSubExpressions</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#promoteWhereClause(net.sf.saxon.expr.Binding)">promoteWhereClause</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#refineTypeInformation(net.sf.saxon.type.ItemType, int, net.sf.saxon.value.Value, int, net.sf.saxon.expr.parser.ExpressionVisitor, net.sf.saxon.expr.Assignation)">refineTypeInformation</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#replaceSubExpression(net.sf.saxon.expr.Expression, net.sf.saxon.expr.Expression)">replaceSubExpression</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#replaceVariable(net.sf.saxon.expr.parser.Optimizer, net.sf.saxon.expr.Expression)">replaceVariable</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#setAction(net.sf.saxon.expr.Expression)">setAction</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#setIndexedVariable()">setIndexedVariable</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#setRequiredType(net.sf.saxon.value.SequenceType)">setRequiredType</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#setSequence(net.sf.saxon.expr.Expression)">setSequence</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#setSlotNumber(int)">setSlotNumber</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#setVariableQName(net.sf.saxon.om.StructuredQName)">setVariableQName</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#simplify(net.sf.saxon.expr.parser.ExpressionVisitor)">simplify</A>, <A HREF="../../../../net/sf/saxon/expr/Assignation.html#suppressValidation(int)">suppressValidation</A></CODE></TD>
</TR>
</TABLE>
<A NAME="methods_inherited_from_class_net.sf.saxon.expr.Expression"><!-- --></A>
<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
<TR BGCOLOR="#EEEEFF" CLASS="TableSubHeadingColor">
<TH ALIGN="left"><B>Methods inherited from class net.sf.saxon.expr.<A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></B></TH>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#adoptChildExpression(net.sf.saxon.expr.Expression)">adoptChildExpression</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#computeDependencies()">computeDependencies</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#computeStaticProperties()">computeStaticProperties</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#doPromotion(net.sf.saxon.expr.Expression, net.sf.saxon.expr.parser.PromotionOffer)">doPromotion</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#dynamicError(java.lang.String, java.lang.String, net.sf.saxon.expr.XPathContext)">dynamicError</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#evaluateAsString(net.sf.saxon.expr.XPathContext)">evaluateAsString</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#explain(java.io.OutputStream)">explain</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getCardinality()">getCardinality</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getColumnNumber()">getColumnNumber</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getColumnNumber(long)">getColumnNumber</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getConstructType()">getConstructType</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getContainer()">getContainer</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getDependencies()">getDependencies</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getEvaluationMethod()">getEvaluationMethod</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getExecutable()">getExecutable</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getHostLanguage()">getHostLanguage</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getImplementationMethod()">getImplementationMethod</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getIntrinsicDependencies()">getIntrinsicDependencies</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getLineNumber()">getLineNumber</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getLineNumber(long)">getLineNumber</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getLocationId()">getLocationId</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getLocationProvider()">getLocationProvider</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getProperties()">getProperties</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getProperty(java.lang.String)">getProperty</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getPublicId()">getPublicId</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getSlotsUsed()">getSlotsUsed</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getSpecialProperties()">getSpecialProperties</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getSystemId()">getSystemId</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#getSystemId(long)">getSystemId</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#hasLoopingSubexpression(net.sf.saxon.expr.Expression)">hasLoopingSubexpression</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#isSubtreeExpression()">isSubtreeExpression</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#iterateSameFocusSubExpressions()">iterateSameFocusSubExpressions</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#resetLocalStaticProperties()">resetLocalStaticProperties</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#setContainer(net.sf.saxon.expr.Container)">setContainer</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#setEvaluationMethod(int)">setEvaluationMethod</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#setFiltered(boolean)">setFiltered</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#setFlattened(boolean)">setFlattened</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#setLocationId(int)">setLocationId</A>, <A HREF="../../../../net/sf/saxon/expr/Expression.html#typeError(java.lang.String, java.lang.String, net.sf.saxon.expr.XPathContext)">typeError</A></CODE></TD>
</TR>
</TABLE>
<A NAME="methods_inherited_from_class_java.lang.Object"><!-- --></A>
<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
<TR BGCOLOR="#EEEEFF" CLASS="TableSubHeadingColor">
<TH ALIGN="left"><B>Methods inherited from class java.lang.<A HREF="http://download.oracle.com/javase/6/docs/api/java/lang/Object.html?is-external=true" title="class or interface in java.lang">Object</A></B></TH>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD><CODE><A HREF="http://download.oracle.com/javase/6/docs/api/java/lang/Object.html?is-external=true#clone()" title="class or interface in java.lang">clone</A>, <A HREF="http://download.oracle.com/javase/6/docs/api/java/lang/Object.html?is-external=true#equals(java.lang.Object)" title="class or interface in java.lang">equals</A>, <A HREF="http://download.oracle.com/javase/6/docs/api/java/lang/Object.html?is-external=true#finalize()" title="class or interface in java.lang">finalize</A>, <A HREF="http://download.oracle.com/javase/6/docs/api/java/lang/Object.html?is-external=true#getClass()" title="class or interface in java.lang">getClass</A>, <A HREF="http://download.oracle.com/javase/6/docs/api/java/lang/Object.html?is-external=true#hashCode()" title="class or interface in java.lang">hashCode</A>, <A HREF="http://download.oracle.com/javase/6/docs/api/java/lang/Object.html?is-external=true#notify()" title="class or interface in java.lang">notify</A>, <A HREF="http://download.oracle.com/javase/6/docs/api/java/lang/Object.html?is-external=true#notifyAll()" title="class or interface in java.lang">notifyAll</A>, <A HREF="http://download.oracle.com/javase/6/docs/api/java/lang/Object.html?is-external=true#wait()" title="class or interface in java.lang">wait</A>, <A HREF="http://download.oracle.com/javase/6/docs/api/java/lang/Object.html?is-external=true#wait(long)" title="class or interface in java.lang">wait</A>, <A HREF="http://download.oracle.com/javase/6/docs/api/java/lang/Object.html?is-external=true#wait(long, int)" title="class or interface in java.lang">wait</A></CODE></TD>
</TR>
</TABLE>
<P>
<!-- ========= CONSTRUCTOR DETAIL ======== -->
<A NAME="constructor_detail"><!-- --></A>
<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
<TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor">
<TH ALIGN="left" COLSPAN="1"><FONT SIZE="+2">
<B>Constructor Detail</B></FONT></TH>
</TR>
</TABLE>
<A NAME="LetExpression()"><!-- --></A><H3>
LetExpression</H3>
<PRE>
public <B>LetExpression</B>()</PRE>
<DL>
<DD>Create a LetExpression
<P>
</DL>
<!-- ============ METHOD DETAIL ========== -->
<A NAME="method_detail"><!-- --></A>
<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
<TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor">
<TH ALIGN="left" COLSPAN="1"><FONT SIZE="+2">
<B>Method Detail</B></FONT></TH>
</TR>
</TABLE>
<A NAME="getExpressionName()"><!-- --></A><H3>
getExpressionName</H3>
<PRE>
public <A HREF="http://download.oracle.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A> <B>getExpressionName</B>()</PRE>
<DL>
<DD>Get a name identifying the kind of expression, in terms meaningful to a user.
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#getExpressionName()">getExpressionName</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Returns:</B><DD>a name identifying the kind of expression, in terms meaningful to a user.
The name will always be in the form of a lexical XML QName, and should match the name used
in explain() output displaying the expression.</DL>
</DD>
</DL>
<HR>
<A NAME="setRefCount(int)"><!-- --></A><H3>
setRefCount</H3>
<PRE>
public void <B>setRefCount</B>(int refCount)</PRE>
<DL>
<DD><DL>
</DL>
</DD>
<DD><DL>
</DL>
</DD>
</DL>
<HR>
<A NAME="typeCheck(net.sf.saxon.expr.parser.ExpressionVisitor, net.sf.saxon.expr.parser.ExpressionVisitor.ContextItemType)"><!-- --></A><H3>
typeCheck</H3>
<PRE>
public <A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A> <B>typeCheck</B>(<A HREF="../../../../net/sf/saxon/expr/parser/ExpressionVisitor.html" title="class in net.sf.saxon.expr.parser">ExpressionVisitor</A> visitor,
<A HREF="../../../../net/sf/saxon/expr/parser/ExpressionVisitor.ContextItemType.html" title="class in net.sf.saxon.expr.parser">ExpressionVisitor.ContextItemType</A> contextItemType)
throws <A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></PRE>
<DL>
<DD>Type-check the expression. This also has the side-effect of counting the number of references
to the variable (treating references that occur within a loop specially)
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#typeCheck(net.sf.saxon.expr.parser.ExpressionVisitor, net.sf.saxon.expr.parser.ExpressionVisitor.ContextItemType)">typeCheck</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>visitor</CODE> - an expression visitor<DD><CODE>contextItemType</CODE> - the static type of "." at the point where this expression is invoked.
The parameter is set to null if it is known statically that the context item will be undefined.
If the type of the context item is not known statically, the argument is set to
<A HREF="../../../../net/sf/saxon/type/Type.html#ITEM_TYPE"><CODE>Type.ITEM_TYPE</CODE></A>
<DT><B>Returns:</B><DD>the original expression, rewritten to perform necessary run-time type checks,
and to perform other type-related optimizations
<DT><B>Throws:</B>
<DD><CODE><A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></CODE> - if an error is discovered during this phase
(typically a type error)</DL>
</DD>
</DL>
<HR>
<A NAME="implementsStaticTypeCheck()"><!-- --></A><H3>
implementsStaticTypeCheck</H3>
<PRE>
public boolean <B>implementsStaticTypeCheck</B>()</PRE>
<DL>
<DD>Determine whether this expression implements its own method for static type checking
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#implementsStaticTypeCheck()">implementsStaticTypeCheck</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Returns:</B><DD>true - this expression has a non-trivial implementation of the staticTypeCheck()
method</DL>
</DD>
</DL>
<HR>
<A NAME="staticTypeCheck(net.sf.saxon.value.SequenceType, boolean, net.sf.saxon.expr.parser.RoleLocator, net.sf.saxon.TypeCheckerEnvironment)"><!-- --></A><H3>
staticTypeCheck</H3>
<PRE>
public <A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A> <B>staticTypeCheck</B>(<A HREF="../../../../net/sf/saxon/value/SequenceType.html" title="class in net.sf.saxon.value">SequenceType</A> req,
boolean backwardsCompatible,
<A HREF="../../../../net/sf/saxon/expr/parser/RoleLocator.html" title="class in net.sf.saxon.expr.parser">RoleLocator</A> role,
<A HREF="../../../../net/sf/saxon/TypeCheckerEnvironment.html" title="interface in net.sf.saxon">TypeCheckerEnvironment</A> visitor)
throws <A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></PRE>
<DL>
<DD>Static type checking for let expressions is delegated to the expression itself,
and is performed on the "action" expression, to allow further delegation to the branches
of a conditional
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#staticTypeCheck(net.sf.saxon.value.SequenceType, boolean, net.sf.saxon.expr.parser.RoleLocator, net.sf.saxon.TypeCheckerEnvironment)">staticTypeCheck</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>req</CODE> - the required type<DD><CODE>backwardsCompatible</CODE> - true if backwards compatibility mode applies<DD><CODE>role</CODE> - the role of the expression in relation to the required type<DD><CODE>visitor</CODE> - an expression visitor
<DT><B>Returns:</B><DD>the expression after type checking (perhaps augmented with dynamic type checking code)
<DT><B>Throws:</B>
<DD><CODE><A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></CODE> - if failures occur, for example if the static type of one branch of the conditional
is incompatible with the required type</DL>
</DD>
</DL>
<HR>
<A NAME="optimize(net.sf.saxon.expr.parser.ExpressionVisitor, net.sf.saxon.expr.parser.ExpressionVisitor.ContextItemType)"><!-- --></A><H3>
optimize</H3>
<PRE>
public <A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A> <B>optimize</B>(<A HREF="../../../../net/sf/saxon/expr/parser/ExpressionVisitor.html" title="class in net.sf.saxon.expr.parser">ExpressionVisitor</A> visitor,
<A HREF="../../../../net/sf/saxon/expr/parser/ExpressionVisitor.ContextItemType.html" title="class in net.sf.saxon.expr.parser">ExpressionVisitor.ContextItemType</A> contextItemType)
throws <A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></PRE>
<DL>
<DD>Perform optimisation of an expression and its subexpressions.
<p/>
<p>This method is called after all references to functions and variables have been resolved
to the declaration of the function or variable, and after all type checking has been done.</p>
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#optimize(net.sf.saxon.expr.parser.ExpressionVisitor, net.sf.saxon.expr.parser.ExpressionVisitor.ContextItemType)">optimize</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>visitor</CODE> - an expression visitor<DD><CODE>contextItemType</CODE> - the static type of "." at the point where this expression is invoked.
The parameter is set to null if it is known statically that the context item will be undefined.
If the type of the context item is not known statically, the argument is set to
<A HREF="../../../../net/sf/saxon/type/Type.html#ITEM_TYPE"><CODE>Type.ITEM_TYPE</CODE></A>
<DT><B>Returns:</B><DD>the original expression, rewritten if appropriate to optimize execution
<DT><B>Throws:</B>
<DD><CODE><A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></CODE> - if an error is discovered during this phase
(typically a type error)</DL>
</DD>
</DL>
<HR>
<A NAME="isVacuousExpression()"><!-- --></A><H3>
isVacuousExpression</H3>
<PRE>
public boolean <B>isVacuousExpression</B>()</PRE>
<DL>
<DD>Determine whether this is a vacuous expression as defined in the XQuery update specification
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#isVacuousExpression()">isVacuousExpression</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Returns:</B><DD>true if this expression is vacuous</DL>
</DD>
</DL>
<HR>
<A NAME="checkPermittedContents(net.sf.saxon.type.SchemaType, net.sf.saxon.expr.StaticContext, boolean)"><!-- --></A><H3>
checkPermittedContents</H3>
<PRE>
public void <B>checkPermittedContents</B>(<A HREF="../../../../net/sf/saxon/type/SchemaType.html" title="interface in net.sf.saxon.type">SchemaType</A> parentType,
<A HREF="../../../../net/sf/saxon/expr/StaticContext.html" title="interface in net.sf.saxon.expr">StaticContext</A> env,
boolean whole)
throws <A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></PRE>
<DL>
<DD>Check that any elements and attributes constructed or returned by this expression are acceptable
in the content model of a given complex type. It's always OK to say yes, since the check will be
repeated at run-time. The process of checking element and attribute constructors against the content
model of a complex type also registers the type of content expected of those constructors, so the
static validation can continue recursively.
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#checkPermittedContents(net.sf.saxon.type.SchemaType, net.sf.saxon.expr.StaticContext, boolean)">checkPermittedContents</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>parentType</CODE> - the "given complex type": the method is checking that the nodes returned by this
expression are acceptable members of the content model of this type<DD><CODE>env</CODE> - the static context<DD><CODE>whole</CODE> - if true, we want to check that the value of this expression satisfies the content model
as a whole; if false we want to check that the value of the expression is acceptable as one part
of the content
<DT><B>Throws:</B>
<DD><CODE><A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></CODE> - if the value delivered by this expression cannot be part of the content model
of the given type</DL>
</DD>
</DL>
<HR>
<A NAME="getIntegerBounds()"><!-- --></A><H3>
getIntegerBounds</H3>
<PRE>
public <A HREF="../../../../net/sf/saxon/value/IntegerValue.html" title="class in net.sf.saxon.value">IntegerValue</A>[] <B>getIntegerBounds</B>()</PRE>
<DL>
<DD>For an expression that returns an integer or a sequence of integers, get
a lower and upper bound on the values of the integers that may be returned, from
static analysis. The default implementation returns null, meaning "unknown" or
"not applicable". Other implementations return an array of two IntegerValue objects,
representing the lower and upper bounds respectively. The values
UNBOUNDED_LOWER and UNBOUNDED_UPPER are used by convention to indicate that
the value may be arbitrarily large. The values MAX_STRING_LENGTH and MAX_SEQUENCE_LENGTH
are used to indicate values limited by the size of a string or the size of a sequence.
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#getIntegerBounds()">getIntegerBounds</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Returns:</B><DD>the lower and upper bounds of integer values in the result, or null to indicate
unknown or not applicable.</DL>
</DD>
</DL>
<HR>
<A NAME="iterate(net.sf.saxon.expr.XPathContext)"><!-- --></A><H3>
iterate</H3>
<PRE>
public <A HREF="../../../../net/sf/saxon/om/SequenceIterator.html" title="interface in net.sf.saxon.om">SequenceIterator</A> <B>iterate</B>(<A HREF="../../../../net/sf/saxon/expr/XPathContext.html" title="interface in net.sf.saxon.expr">XPathContext</A> context)
throws <A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></PRE>
<DL>
<DD>Iterate over the result of the expression to return a sequence of items
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#iterate(net.sf.saxon.expr.XPathContext)">iterate</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>context</CODE> - supplies the context for evaluation
<DT><B>Returns:</B><DD>a SequenceIterator that can be used to iterate over the result
of the expression
<DT><B>Throws:</B>
<DD><CODE><A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></CODE> - if any dynamic error occurs evaluating the
expression</DL>
</DD>
</DL>
<HR>
<A NAME="iterateEvents(net.sf.saxon.expr.XPathContext)"><!-- --></A><H3>
iterateEvents</H3>
<PRE>
public <A HREF="../../../../net/sf/saxon/evpull/EventIterator.html" title="interface in net.sf.saxon.evpull">EventIterator</A> <B>iterateEvents</B>(<A HREF="../../../../net/sf/saxon/expr/XPathContext.html" title="interface in net.sf.saxon.expr">XPathContext</A> context)
throws <A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></PRE>
<DL>
<DD>Iterate over the result of the expression to return a sequence of events
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#iterateEvents(net.sf.saxon.expr.XPathContext)">iterateEvents</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>context</CODE> - The dynamic evaluation context
<DT><B>Returns:</B><DD>the result of the expression as an iterator over a sequence of PullEvent objects
<DT><B>Throws:</B>
<DD><CODE><A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></CODE> - if a dynamic error occurs during expression evaluation</DL>
</DD>
</DL>
<HR>
<A NAME="eval(net.sf.saxon.expr.XPathContext)"><!-- --></A><H3>
eval</H3>
<PRE>
public <A HREF="../../../../net/sf/saxon/om/ValueRepresentation.html" title="interface in net.sf.saxon.om">ValueRepresentation</A> <B>eval</B>(<A HREF="../../../../net/sf/saxon/expr/XPathContext.html" title="interface in net.sf.saxon.expr">XPathContext</A> context)
throws <A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></PRE>
<DL>
<DD>Evaluate the variable.
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>context</CODE> - the dynamic evaluation context
<DT><B>Returns:</B><DD>the result of evaluating the expression that is bound to the variable
<DT><B>Throws:</B>
<DD><CODE><A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></CODE></DL>
</DD>
</DL>
<HR>
<A NAME="evaluateItem(net.sf.saxon.expr.XPathContext)"><!-- --></A><H3>
evaluateItem</H3>
<PRE>
public <A HREF="../../../../net/sf/saxon/om/Item.html" title="interface in net.sf.saxon.om">Item</A> <B>evaluateItem</B>(<A HREF="../../../../net/sf/saxon/expr/XPathContext.html" title="interface in net.sf.saxon.expr">XPathContext</A> context)
throws <A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></PRE>
<DL>
<DD>Evaluate the expression as a singleton
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#evaluateItem(net.sf.saxon.expr.XPathContext)">evaluateItem</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>context</CODE> - The context in which the expression is to be evaluated
<DT><B>Returns:</B><DD>the node or atomic value that results from evaluating the
expression; or null to indicate that the result is an empty
sequence
<DT><B>Throws:</B>
<DD><CODE><A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></CODE> - if any dynamic error occurs evaluating the
expression</DL>
</DD>
</DL>
<HR>
<A NAME="effectiveBooleanValue(net.sf.saxon.expr.XPathContext)"><!-- --></A><H3>
effectiveBooleanValue</H3>
<PRE>
public boolean <B>effectiveBooleanValue</B>(<A HREF="../../../../net/sf/saxon/expr/XPathContext.html" title="interface in net.sf.saxon.expr">XPathContext</A> context)
throws <A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></PRE>
<DL>
<DD>Get the effective boolean value of the expression. This returns false if the value
is the empty sequence, a zero-length string, a number equal to zero, or the boolean
false. Otherwise it returns true.
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#effectiveBooleanValue(net.sf.saxon.expr.XPathContext)">effectiveBooleanValue</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>context</CODE> - The context in which the expression is to be evaluated
<DT><B>Returns:</B><DD>the effective boolean value
<DT><B>Throws:</B>
<DD><CODE><A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></CODE> - if any dynamic error occurs evaluating the
expression</DL>
</DD>
</DL>
<HR>
<A NAME="process(net.sf.saxon.expr.XPathContext)"><!-- --></A><H3>
process</H3>
<PRE>
public void <B>process</B>(<A HREF="../../../../net/sf/saxon/expr/XPathContext.html" title="interface in net.sf.saxon.expr">XPathContext</A> context)
throws <A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></PRE>
<DL>
<DD>Process this expression as an instruction, writing results to the current
outputter
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#process(net.sf.saxon.expr.XPathContext)">process</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>context</CODE> - The dynamic context, giving access to the current node,
the current variables, etc.
<DT><B>Throws:</B>
<DD><CODE><A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></CODE> - if a dynamic error occurs</DL>
</DD>
</DL>
<HR>
<A NAME="getItemType(net.sf.saxon.type.TypeHierarchy)"><!-- --></A><H3>
getItemType</H3>
<PRE>
public <A HREF="../../../../net/sf/saxon/type/ItemType.html" title="interface in net.sf.saxon.type">ItemType</A> <B>getItemType</B>(<A HREF="../../../../net/sf/saxon/type/TypeHierarchy.html" title="class in net.sf.saxon.type">TypeHierarchy</A> th)</PRE>
<DL>
<DD>Determine the data type of the items returned by the expression, if possible
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#getItemType(net.sf.saxon.type.TypeHierarchy)">getItemType</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>th</CODE> - the type hierarchy cache
<DT><B>Returns:</B><DD>one of the values Type.STRING, Type.BOOLEAN, Type.NUMBER, Type.NODE,
or Type.ITEM (meaning not known in advance)</DL>
</DD>
</DL>
<HR>
<A NAME="computeCardinality()"><!-- --></A><H3>
computeCardinality</H3>
<PRE>
public int <B>computeCardinality</B>()</PRE>
<DL>
<DD>Determine the static cardinality of the expression
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#computeCardinality()">computeCardinality</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Returns:</B><DD>the computed cardinality, as one of the values <A HREF="../../../../net/sf/saxon/expr/StaticProperty.html#ALLOWS_ZERO_OR_ONE"><CODE>StaticProperty.ALLOWS_ZERO_OR_ONE</CODE></A>,
<A HREF="../../../../net/sf/saxon/expr/StaticProperty.html#EXACTLY_ONE"><CODE>StaticProperty.EXACTLY_ONE</CODE></A>, <A HREF="../../../../net/sf/saxon/expr/StaticProperty.html#ALLOWS_ONE_OR_MORE"><CODE>StaticProperty.ALLOWS_ONE_OR_MORE</CODE></A>,
<A HREF="../../../../net/sf/saxon/expr/StaticProperty.html#ALLOWS_ZERO_OR_MORE"><CODE>StaticProperty.ALLOWS_ZERO_OR_MORE</CODE></A></DL>
</DD>
</DL>
<HR>
<A NAME="computeSpecialProperties()"><!-- --></A><H3>
computeSpecialProperties</H3>
<PRE>
public int <B>computeSpecialProperties</B>()</PRE>
<DL>
<DD>Get the static properties of this expression (other than its type). The result is
bit-signficant. These properties are used for optimizations. In general, if
property bit is set, it is true, but if it is unset, the value is unknown.
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#computeSpecialProperties()">computeSpecialProperties</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Returns:</B><DD>the special properties, as a bit-significant integer</DL>
</DD>
</DL>
<HR>
<A NAME="markTailFunctionCalls(net.sf.saxon.om.StructuredQName, int)"><!-- --></A><H3>
markTailFunctionCalls</H3>
<PRE>
public int <B>markTailFunctionCalls</B>(<A HREF="../../../../net/sf/saxon/om/StructuredQName.html" title="class in net.sf.saxon.om">StructuredQName</A> qName,
int arity)</PRE>
<DL>
<DD>Mark tail function calls
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#markTailFunctionCalls(net.sf.saxon.om.StructuredQName, int)">markTailFunctionCalls</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>qName</CODE> - the name of the function<DD><CODE>arity</CODE> - the arity (number of parameters) of the function
<DT><B>Returns:</B><DD><A HREF="../../../../net/sf/saxon/expr/UserFunctionCall.html#NOT_TAIL_CALL"><CODE>UserFunctionCall.NOT_TAIL_CALL</CODE></A> if no tail call was found;
<A HREF="../../../../net/sf/saxon/expr/UserFunctionCall.html#FOREIGN_TAIL_CALL"><CODE>UserFunctionCall.FOREIGN_TAIL_CALL</CODE></A> if a tail call on a different function was found;</DL>
</DD>
</DL>
<HR>
<A NAME="promote(net.sf.saxon.expr.parser.PromotionOffer, net.sf.saxon.expr.Expression)"><!-- --></A><H3>
promote</H3>
<PRE>
public <A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A> <B>promote</B>(<A HREF="../../../../net/sf/saxon/expr/parser/PromotionOffer.html" title="class in net.sf.saxon.expr.parser">PromotionOffer</A> offer,
<A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A> parent)
throws <A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></PRE>
<DL>
<DD>Promote this expression if possible
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Assignation.html#promote(net.sf.saxon.expr.parser.PromotionOffer, net.sf.saxon.expr.Expression)">promote</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Assignation.html" title="class in net.sf.saxon.expr">Assignation</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>offer</CODE> - details of the offer, for example the offer to move
expressions that don't depend on the context to an outer level in
the containing expression<DD><CODE>parent</CODE> - the containing expression in the expression tree
<DT><B>Returns:</B><DD>if the offer is not accepted, return this expression unchanged.
Otherwise return the result of rewriting the expression to promote
this subexpression
<DT><B>Throws:</B>
<DD><CODE><A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></CODE> - if any error is detected</DL>
</DD>
</DL>
<HR>
<A NAME="copy()"><!-- --></A><H3>
copy</H3>
<PRE>
public <A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A> <B>copy</B>()</PRE>
<DL>
<DD>Copy an expression. This makes a deep copy.
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#copy()">copy</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Returns:</B><DD>the copy of the original expression</DL>
</DD>
</DL>
<HR>
<A NAME="processLeavingTail(net.sf.saxon.expr.XPathContext)"><!-- --></A><H3>
processLeavingTail</H3>
<PRE>
public <A HREF="../../../../net/sf/saxon/expr/instruct/TailCall.html" title="interface in net.sf.saxon.expr.instruct">TailCall</A> <B>processLeavingTail</B>(<A HREF="../../../../net/sf/saxon/expr/XPathContext.html" title="interface in net.sf.saxon.expr">XPathContext</A> context)
throws <A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></PRE>
<DL>
<DD>ProcessLeavingTail: called to do the real work of this instruction.
The results of the instruction are written
to the current Receiver, which can be obtained via the Controller.
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/instruct/TailCallReturner.html#processLeavingTail(net.sf.saxon.expr.XPathContext)">processLeavingTail</A></CODE> in interface <CODE><A HREF="../../../../net/sf/saxon/expr/instruct/TailCallReturner.html" title="interface in net.sf.saxon.expr.instruct">TailCallReturner</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>context</CODE> - The dynamic context of the transformation, giving access to the current node,
the current variables, etc.
<DT><B>Returns:</B><DD>null if the instruction has completed execution; or a TailCall indicating
a function call or template call that is delegated to the caller, to be made after the stack has
been unwound so as to save stack space.
<DT><B>Throws:</B>
<DD><CODE><A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></CODE> - if a dynamic error occurs during the evaluation
of the instruction</DL>
</DD>
</DL>
<HR>
<A NAME="evaluatePendingUpdates(net.sf.saxon.expr.XPathContext, net.sf.saxon.expr.PendingUpdateList)"><!-- --></A><H3>
evaluatePendingUpdates</H3>
<PRE>
public void <B>evaluatePendingUpdates</B>(<A HREF="../../../../net/sf/saxon/expr/XPathContext.html" title="interface in net.sf.saxon.expr">XPathContext</A> context,
<A HREF="../../../../net/sf/saxon/expr/PendingUpdateList.html" title="interface in net.sf.saxon.expr">PendingUpdateList</A> pul)
throws <A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></PRE>
<DL>
<DD>Evaluate an updating expression, adding the results to a Pending Update List.
The default implementation of this method, which is used for non-updating expressions,
throws an UnsupportedOperationException
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#evaluatePendingUpdates(net.sf.saxon.expr.XPathContext, net.sf.saxon.expr.PendingUpdateList)">evaluatePendingUpdates</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>context</CODE> - the XPath dynamic evaluation context<DD><CODE>pul</CODE> - the pending update list to which the results should be written
<DT><B>Throws:</B>
<DD><CODE><A HREF="../../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></CODE> - if evaluation fails</DL>
</DD>
</DL>
<HR>
<A NAME="toString()"><!-- --></A><H3>
toString</H3>
<PRE>
public <A HREF="http://download.oracle.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A> <B>toString</B>()</PRE>
<DL>
<DD>The toString() method for an expression attempts to give a representation of the expression
in an XPath-like form, but there is no guarantee that the syntax will actually be true XPath.
In the case of XSLT instructions, the toString() method gives an abstracted view of the syntax
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#toString()">toString</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Returns:</B><DD>a representation of the expression as a string</DL>
</DD>
</DL>
<HR>
<A NAME="explain(net.sf.saxon.trace.ExpressionPresenter)"><!-- --></A><H3>
explain</H3>
<PRE>
public void <B>explain</B>(<A HREF="../../../../net/sf/saxon/trace/ExpressionPresenter.html" title="class in net.sf.saxon.trace">ExpressionPresenter</A> out)</PRE>
<DL>
<DD>Diagnostic print of expression structure. The abstract expression tree
is written to the supplied output destination.
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html#explain(net.sf.saxon.trace.ExpressionPresenter)">explain</A></CODE> in class <CODE><A HREF="../../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>out</CODE> - the expression presenter used to display the structure</DL>
</DD>
</DL>
<HR>
<A NAME="setEvaluationMode(int)"><!-- --></A><H3>
setEvaluationMode</H3>
<PRE>
public void <B>setEvaluationMode</B>(int evaluationMode)</PRE>
<DL>
<DD><DL>
</DL>
</DD>
<DD><DL>
</DL>
</DD>
</DL>
<HR>
<A NAME="getEvaluationMode()"><!-- --></A><H3>
getEvaluationMode</H3>
<PRE>
public int <B>getEvaluationMode</B>()</PRE>
<DL>
<DD><DL>
</DL>
</DD>
<DD><DL>
</DL>
</DD>
</DL>
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