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CopyModifyExpression
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SUMMARY: NESTED | <A HREF="#fields_inherited_from_class_net.sf.saxon.expr.Expression">FIELD</A> | <A HREF="#constructor_summary">CONSTR</A> | <A HREF="#method_summary">METHOD</A></FONT></TD>
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com.saxonica.update</FONT>
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Class CopyModifyExpression</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 "><B>com.saxonica.update.CopyModifyExpression</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/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>
<HR>
<DL>
<DT><PRE>public class <B>CopyModifyExpression</B><DT>extends <A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></DL>
</PRE>
<P>
A copy-modify expression (called a "transform" expression in the XQuery Update specification)
<P>
<P>
<DL>
<DT><B>See Also:</B><DD><A HREF="../../../serialized-form.html#com.saxonica.update.CopyModifyExpression">Serialized Form</A></DL>
<HR>
<P>
<!-- =========== FIELD SUMMARY =========== -->
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<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
<TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor">
<TH ALIGN="left" COLSPAN="2"><FONT SIZE="+2">
<B>Field Summary</B></FONT></TH>
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</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>
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<TR BGCOLOR="white" CLASS="TableRowColor">
<TD><CODE><B><A HREF="../../../com/saxonica/update/CopyModifyExpression.html#CopyModifyExpression(net.sf.saxon.expr.Expression, net.sf.saxon.expr.Expression, int)">CopyModifyExpression</A></B>(<A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A> updateExp,
<A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A> returnExp,
int validationMode)</CODE>
<BR>
Create a copy-modify expression (also known as a transform expresion)</TD>
</TR>
</TABLE>
<!-- ========== METHOD SUMMARY =========== -->
<A NAME="method_summary"><!-- --></A>
<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
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<B>Method Summary</B></FONT></TH>
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<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="../../../com/saxonica/update/CopyModifyExpression.html#checkForUpdatingSubexpressions()">checkForUpdatingSubexpressions</A></B>()</CODE>
<BR>
Check to ensure that this expression does not contain any inappropriate updating subexpressions.</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="../../../com/saxonica/update/CopyModifyExpression.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> <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="../../../com/saxonica/update/CopyModifyExpression.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> <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="../../../com/saxonica/update/CopyModifyExpression.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 an expression as a single item.</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="../../../com/saxonica/update/CopyModifyExpression.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> <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="../../../com/saxonica/update/CopyModifyExpression.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 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="../../../com/saxonica/update/CopyModifyExpression.html#isUpdatingExpression()">isUpdatingExpression</A></B>()</CODE>
<BR>
Determine whether this is an updating 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="../../../com/saxonica/update/CopyModifyExpression.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>
Return an Iterator to iterate over the values of a sequence.</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="../../../com/saxonica/update/CopyModifyExpression.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>
Deliver the result of the expression as a sequence of events.</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/util/Iterator.html?is-external=true" title="class or interface in java.util">Iterator</A><<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="../../../com/saxonica/update/CopyModifyExpression.html#iterateSubExpressions()">iterateSubExpressions</A></B>()</CODE>
<BR>
Get the immediate sub-expressions of this expression.</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="../../../com/saxonica/update/CopyModifyExpression.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="../../../com/saxonica/update/CopyModifyExpression.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 the instruction, without returning any tail 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="../../../com/saxonica/update/CopyModifyExpression.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>
Offer promotion for this subexpression.</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="../../../com/saxonica/update/CopyModifyExpression.html#replaceSubExpression(net.sf.saxon.expr.Expression, net.sf.saxon.expr.Expression)">replaceSubExpression</A></B>(<A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A> original,
<A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A> replacement)</CODE>
<BR>
Replace one subexpression by a replacement subexpression</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="../../../com/saxonica/update/CopyModifyExpression.html#setCopyBindings(net.sf.saxon.expr.Expression)">setCopyBindings</A></B>(<A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A> copyBindings)</CODE>
<BR>
Set the copy bindings.</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="../../../com/saxonica/update/CopyModifyExpression.html#simplify(net.sf.saxon.expr.parser.ExpressionVisitor)">simplify</A></B>(<A HREF="../../../net/sf/saxon/expr/parser/ExpressionVisitor.html" title="class in net.sf.saxon.expr.parser">ExpressionVisitor</A> visitor)</CODE>
<BR>
Simplify an expression.</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="../../../com/saxonica/update/CopyModifyExpression.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>
Perform type checking of an expression and its subexpressions.</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#addToPathMap(net.sf.saxon.expr.parser.PathMap, net.sf.saxon.expr.parser.PathMap.PathMapNodeSet)">addToPathMap</A>, <A HREF="../../../net/sf/saxon/expr/Expression.html#adoptChildExpression(net.sf.saxon.expr.Expression)">adoptChildExpression</A>, <A HREF="../../../net/sf/saxon/expr/Expression.html#checkPermittedContents(net.sf.saxon.type.SchemaType, net.sf.saxon.expr.StaticContext, boolean)">checkPermittedContents</A>, <A HREF="../../../net/sf/saxon/expr/Expression.html#computeDependencies()">computeDependencies</A>, <A HREF="../../../net/sf/saxon/expr/Expression.html#computeSpecialProperties()">computeSpecialProperties</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#effectiveBooleanValue(net.sf.saxon.expr.XPathContext)">effectiveBooleanValue</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#evaluatePendingUpdates(net.sf.saxon.expr.XPathContext, net.sf.saxon.expr.PendingUpdateList)">evaluatePendingUpdates</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#getExpressionName()">getExpressionName</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#getIntegerBounds()">getIntegerBounds</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#getObjectName()">getObjectName</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#hasVariableBinding(net.sf.saxon.expr.Binding)">hasVariableBinding</A>, <A HREF="../../../net/sf/saxon/expr/Expression.html#implementsStaticTypeCheck()">implementsStaticTypeCheck</A>, <A HREF="../../../net/sf/saxon/expr/Expression.html#isSubtreeExpression()">isSubtreeExpression</A>, <A HREF="../../../net/sf/saxon/expr/Expression.html#isVacuousExpression()">isVacuousExpression</A>, <A HREF="../../../net/sf/saxon/expr/Expression.html#iterateSameFocusSubExpressions()">iterateSameFocusSubExpressions</A>, <A HREF="../../../net/sf/saxon/expr/Expression.html#markTailFunctionCalls(net.sf.saxon.om.StructuredQName, int)">markTailFunctionCalls</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#staticTypeCheck(net.sf.saxon.value.SequenceType, boolean, net.sf.saxon.expr.parser.RoleLocator, net.sf.saxon.TypeCheckerEnvironment)">staticTypeCheck</A>, <A HREF="../../../net/sf/saxon/expr/Expression.html#suppressValidation(int)">suppressValidation</A>, <A HREF="../../../net/sf/saxon/expr/Expression.html#toString()">toString</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="CopyModifyExpression(net.sf.saxon.expr.Expression, net.sf.saxon.expr.Expression, int)"><!-- --></A><H3>
CopyModifyExpression</H3>
<PRE>
public <B>CopyModifyExpression</B>(<A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A> updateExp,
<A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A> returnExp,
int validationMode)</PRE>
<DL>
<DD>Create a copy-modify expression (also known as a transform expresion)
<P>
<DL>
<DT><B>Parameters:</B><DD><CODE>updateExp</CODE> - the expression appearing in the modify clause<DD><CODE>returnExp</CODE> - the expression appearing in the return clause<DD><CODE>validationMode</CODE> - the mode for validating the updated nodes (strict, lax, or skip)</DL>
</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="setCopyBindings(net.sf.saxon.expr.Expression)"><!-- --></A><H3>
setCopyBindings</H3>
<PRE>
public void <B>setCopyBindings</B>(<A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A> copyBindings)</PRE>
<DL>
<DD>Set the copy bindings. This is an expression whose value is the set of nodes that are allowed to be
updated. Normally it will consist of a variable reference or a sequence of variable references.
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>copyBindings</CODE> - the set of Let expressions that bind variables that were copied during the copy
phase and that therefore may be updated during the modify phase</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. This establishes how many items
there will be in the result of the expression, at compile time (i.e., without
actually evaluating the result.
<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>one of the values Cardinality.ONE_OR_MORE,
Cardinality.ZERO_OR_MORE, Cardinality.EXACTLY_ONE,
Cardinality.ZERO_OR_ONE, Cardinality.EMPTY. This default
implementation returns ZERO_OR_MORE (which effectively gives no
information).</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 expression, if possible. All expression return
sequences, in general; this method determines the type of the items within the
sequence, assuming that (a) this is known in advance, and (b) it is the same for
all items in the sequence.
<p/>
<p>This method should always return a result, though it may be the best approximation
that is available at the time.</p>
<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>a value such as Type.STRING, Type.BOOLEAN, Type.NUMBER,
Type.NODE, or Type.ITEM (meaning not known at compile time)</DL>
</DD>
</DL>
<HR>
<A NAME="isUpdatingExpression()"><!-- --></A><H3>
isUpdatingExpression</H3>
<PRE>
public boolean <B>isUpdatingExpression</B>()</PRE>
<DL>
<DD>Determine whether this is an updating 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#isUpdatingExpression()">isUpdatingExpression</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>false: although this expression performs updates, it is not classified as an updating
expression</DL>
</DD>
</DL>
<HR>
<A NAME="iterateSubExpressions()"><!-- --></A><H3>
iterateSubExpressions</H3>
<PRE>
public <A HREF="http://download.oracle.com/javase/6/docs/api/java/util/Iterator.html?is-external=true" title="class or interface in java.util">Iterator</A><<A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A>> <B>iterateSubExpressions</B>()</PRE>
<DL>
<DD>Get the immediate sub-expressions of this expression. Default implementation
returns a zero-length array, appropriate for an expression that has no
sub-expressions.
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../net/sf/saxon/expr/Expression.html#iterateSubExpressions()">iterateSubExpressions</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>an iterator containing the sub-expressions of this expression</DL>
</DD>
</DL>
<HR>
<A NAME="checkForUpdatingSubexpressions()"><!-- --></A><H3>
checkForUpdatingSubexpressions</H3>
<PRE>
public void <B>checkForUpdatingSubexpressions</B>()
throws <A HREF="../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></PRE>
<DL>
<DD>Check to ensure that this expression does not contain any inappropriate updating subexpressions.
This check is overridden for those expressions that permit updating subexpressions.
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../net/sf/saxon/expr/Expression.html#checkForUpdatingSubexpressions()">checkForUpdatingSubexpressions</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>Throws:</B>
<DD><CODE><A HREF="../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></CODE> - if the expression has a non-permitted updating subexpression</DL>
</DD>
</DL>
<HR>
<A NAME="replaceSubExpression(net.sf.saxon.expr.Expression, net.sf.saxon.expr.Expression)"><!-- --></A><H3>
replaceSubExpression</H3>
<PRE>
public boolean <B>replaceSubExpression</B>(<A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A> original,
<A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A> replacement)</PRE>
<DL>
<DD>Replace one subexpression by a replacement subexpression
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../net/sf/saxon/expr/Expression.html#replaceSubExpression(net.sf.saxon.expr.Expression, net.sf.saxon.expr.Expression)">replaceSubExpression</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>original</CODE> - the original subexpression<DD><CODE>replacement</CODE> - the replacement subexpression
<DT><B>Returns:</B><DD>true if the original subexpression is found</DL>
</DD>
</DL>
<HR>
<A NAME="simplify(net.sf.saxon.expr.parser.ExpressionVisitor)"><!-- --></A><H3>
simplify</H3>
<PRE>
public <A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A> <B>simplify</B>(<A HREF="../../../net/sf/saxon/expr/parser/ExpressionVisitor.html" title="class in net.sf.saxon.expr.parser">ExpressionVisitor</A> visitor)
throws <A HREF="../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></PRE>
<DL>
<DD>Simplify an expression. This performs any static optimization (by rewriting the expression
as a different expression). The default implementation does nothing.
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../net/sf/saxon/expr/Expression.html#simplify(net.sf.saxon.expr.parser.ExpressionVisitor)">simplify</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
<DT><B>Returns:</B><DD>the simplified 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 an error is discovered during expression
rewriting</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>Perform type checking of an expression and its subexpressions. This is the second phase of
static optimization.
<p/>
<p>This checks statically that the operands of the expression have
the correct type; if necessary it generates code to do run-time type checking or type
conversion. A static type error is reported only if execution cannot possibly succeed, that
is, if a run-time type error is inevitable. The call may return a modified form of the expression.</p>
<p/>
<p>This method is called after all references to functions and variables have been resolved
to the declaration of the function or variable. However, the types of such functions and
variables may not be accurately known if they have not been explicitly declared.</p>
<p/>
<p>If the implementation returns a value other than "this", then it is required to ensure that
the parent pointer and location information in the returned expression have been set up correctly.
It should not rely on the caller to do this, although for historical reasons many callers do so.</p>
<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="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. This is the third and final
phase of static optimization.
<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="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>Offer promotion for this subexpression. The offer will be accepted if the subexpression
is not dependent on the factors (e.g. the context item) identified in the PromotionOffer.
By default the offer is not accepted - this is appropriate in the case of simple expressions
such as constant values and variable references where promotion would give no performance
advantage. This method is always called at compile time.
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../net/sf/saxon/expr/Expression.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/Expression.html" title="class in net.sf.saxon.expr">Expression</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> -
<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="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="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>Return an Iterator to iterate over the values of a sequence. The value of every
expression can be regarded as a sequence, so this method is supported for all
expressions. This default implementation handles iteration for expressions that
return singleton values: for non-singleton expressions, the subclass must
provide its own implementation.
<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="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 an expression as a single item. This always returns either a single Item or
null (denoting the empty sequence). No conversion is done. This method should not be
used unless the static type of the expression is a subtype of "item" or "item?": that is,
it should not be called if the expression may return a sequence. There is no guarantee that
this condition will be detected.
<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="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>Deliver the result of the expression as a sequence of events.
<p/>
<p>The events (of class <A HREF="../../../net/sf/saxon/evpull/PullEvent.html" title="interface in net.sf.saxon.evpull"><CODE>PullEvent</CODE></A>) are either complete
items, or one of startElement, endElement, startDocument, or endDocument, known
as semi-nodes. The stream of events may also include a nested EventIterator.
If a start-end pair exists in the sequence, then the events between
this pair represent the content of the document or element. The content sequence will
have been processed to the extent that any attribute and namespace nodes in the
content sequence will have been merged into the startElement event. Namespace fixup
will have been performed: that is, unique prefixes will have been allocated to element
and attribute nodes, and all namespaces will be declared by means of a namespace node
in the startElement event or in an outer startElement forming part of the sequence.
However, duplicate namespaces may appear in the sequence.</p>
<p>The content of an element or document may include adjacent or zero-length text nodes,
atomic values, and nodes represented as nodes rather than broken down into events.</p>
<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="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 the instruction, without returning any tail calls
<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>
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