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IndexedLookupExpression
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com.saxonica.expr</FONT>
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Class IndexedLookupExpression</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.expr.IndexedLookupExpression</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 final class <B>IndexedLookupExpression</B><DT>extends <A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A></DL>
</PRE>

<P>
An IndexedLookupExpression contains a base expression and a lookup expression. The base expression
 will always be a local variable reference. The expression returns true if the base expression (after
 atomization) contains the value of the lookup expression. That is, the expression is equivalent to
 exists(base[lookup]), except that lookup is evaluated with the same context as base.
<P>

<P>
<DL>
<DT><B>See Also:</B><DD><A HREF="../../../serialized-form.html#com.saxonica.expr.IndexedLookupExpression">Serialized Form</A></DL>
<HR>

<P>
<!-- =========== FIELD SUMMARY =========== -->

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&nbsp;<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="../../../com/saxonica/expr/IndexedLookupExpression.html#IndexedLookupExpression(net.sf.saxon.expr.VariableReference, net.sf.saxon.expr.Expression, net.sf.saxon.expr.sort.AtomicComparer)">IndexedLookupExpression</A></B>(<A HREF="../../../net/sf/saxon/expr/VariableReference.html" title="class in net.sf.saxon.expr">VariableReference</A>&nbsp;base,
                        <A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A>&nbsp;lookup,
                        <A HREF="../../../net/sf/saxon/expr/sort/AtomicComparer.html" title="interface in net.sf.saxon.expr.sort">AtomicComparer</A>&nbsp;comparer)</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Constructor</TD>
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<!-- ========== METHOD SUMMARY =========== -->

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<B>Method Summary</B></FONT></TH>
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<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;int</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../com/saxonica/expr/IndexedLookupExpression.html#computeCardinality()">computeCardinality</A></B>()</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Get the static cardinality of this expression</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;int</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../com/saxonica/expr/IndexedLookupExpression.html#computeDependencies()">computeDependencies</A></B>()</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Determine which aspects of the context the expression depends on.</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;int</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../com/saxonica/expr/IndexedLookupExpression.html#computeSpecialProperties()">computeSpecialProperties</A></B>()</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;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>&nbsp;<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/expr/IndexedLookupExpression.html#copy()">copy</A></B>()</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Copy an expression.</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;boolean</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../com/saxonica/expr/IndexedLookupExpression.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>&nbsp;context)</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;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>&nbsp;boolean</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../com/saxonica/expr/IndexedLookupExpression.html#equals(java.lang.Object)">equals</A></B>(<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>&nbsp;other)</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Is this expression the same as another expression?</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;<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/expr/IndexedLookupExpression.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>&nbsp;context)</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;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>&nbsp;void</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../com/saxonica/expr/IndexedLookupExpression.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>&nbsp;destination)</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Diagnostic print of expression structure.</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;<A HREF="../../../net/sf/saxon/expr/sort/AtomicComparer.html" title="interface in net.sf.saxon.expr.sort">AtomicComparer</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../com/saxonica/expr/IndexedLookupExpression.html#getAtomicComparer()">getAtomicComparer</A></B>()</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Get the atomic comparer used</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;<A HREF="../../../net/sf/saxon/expr/VariableReference.html" title="class in net.sf.saxon.expr">VariableReference</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../com/saxonica/expr/IndexedLookupExpression.html#getBaseExpression()">getBaseExpression</A></B>()</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Get the underlying expression</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;<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/expr/IndexedLookupExpression.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>&nbsp;th)</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Get the data type of the items returned</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;<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/expr/IndexedLookupExpression.html#getLookup()">getLookup</A></B>()</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Get the lookup expression</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;<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/expr/IndexedLookupExpression.html#getUseExpression()">getUseExpression</A></B>()</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Get the expression that computes the key</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;int</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../com/saxonica/expr/IndexedLookupExpression.html#hashCode()">hashCode</A></B>()</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;get HashCode for comparing two expressions</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;<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>&lt;<A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A>&gt;</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../com/saxonica/expr/IndexedLookupExpression.html#iterateSubExpressions()">iterateSubExpressions</A></B>()</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Get the immediate subexpressions of this expression</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;<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/expr/IndexedLookupExpression.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>&nbsp;visitor,
         <A HREF="../../../net/sf/saxon/expr/parser/ExpressionVisitor.ContextItemType.html" title="class in net.sf.saxon.expr.parser">ExpressionVisitor.ContextItemType</A>&nbsp;contextItemType)</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;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>&nbsp;<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/expr/IndexedLookupExpression.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>&nbsp;offer,
        <A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A>&nbsp;parent)</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Promote this expression if possible</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;boolean</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../com/saxonica/expr/IndexedLookupExpression.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>&nbsp;original,
                     <A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A>&nbsp;replacement)</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;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>&nbsp;<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/expr/IndexedLookupExpression.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>&nbsp;visitor)</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Simplify an expression</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;<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/expr/IndexedLookupExpression.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>&nbsp;visitor,
          <A HREF="../../../net/sf/saxon/expr/parser/ExpressionVisitor.ContextItemType.html" title="class in net.sf.saxon.expr.parser">ExpressionVisitor.ContextItemType</A>&nbsp;contextItemType)</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Type-check the expression</TD>
</TR>
</TABLE>
&nbsp;<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#checkForUpdatingSubexpressions()">checkForUpdatingSubexpressions</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#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#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#isUpdatingExpression()">isUpdatingExpression</A>, <A HREF="../../../net/sf/saxon/expr/Expression.html#isVacuousExpression()">isVacuousExpression</A>, <A HREF="../../../net/sf/saxon/expr/Expression.html#iterate(net.sf.saxon.expr.XPathContext)">iterate</A>, <A HREF="../../../net/sf/saxon/expr/Expression.html#iterateEvents(net.sf.saxon.expr.XPathContext)">iterateEvents</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#process(net.sf.saxon.expr.XPathContext)">process</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>
&nbsp;<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#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#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>
&nbsp;
<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="IndexedLookupExpression(net.sf.saxon.expr.VariableReference, net.sf.saxon.expr.Expression, net.sf.saxon.expr.sort.AtomicComparer)"><!-- --></A><H3>
IndexedLookupExpression</H3>
<PRE>
public <B>IndexedLookupExpression</B>(<A HREF="../../../net/sf/saxon/expr/VariableReference.html" title="class in net.sf.saxon.expr">VariableReference</A>&nbsp;base,
                               <A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A>&nbsp;lookup,
                               <A HREF="../../../net/sf/saxon/expr/sort/AtomicComparer.html" title="interface in net.sf.saxon.expr.sort">AtomicComparer</A>&nbsp;comparer)</PRE>
<DL>
<DD>Constructor
<P>
<DL>
<DT><B>Parameters:</B><DD><CODE>base</CODE> - A sequence expression denoting the sequence to be searched<DD><CODE>lookup</CODE> - An expression defining value to be sought</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="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>&nbsp;th)</PRE>
<DL>
<DD>Get the data type of the items returned
<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>an integer representing the data type</DL>
</DD>
</DL>
<HR>

<A NAME="getBaseExpression()"><!-- --></A><H3>
getBaseExpression</H3>
<PRE>
public <A HREF="../../../net/sf/saxon/expr/VariableReference.html" title="class in net.sf.saxon.expr">VariableReference</A> <B>getBaseExpression</B>()</PRE>
<DL>
<DD>Get the underlying expression
<P>
<DD><DL>

<DT><B>Returns:</B><DD>the expression being filtered</DL>
</DD>
</DL>
<HR>

<A NAME="getLookup()"><!-- --></A><H3>
getLookup</H3>
<PRE>
public <A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A> <B>getLookup</B>()</PRE>
<DL>
<DD>Get the lookup expression
<P>
<DD><DL>

<DT><B>Returns:</B><DD>the expression acting as the filter predicate</DL>
</DD>
</DL>
<HR>

<A NAME="getUseExpression()"><!-- --></A><H3>
getUseExpression</H3>
<PRE>
public <A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A> <B>getUseExpression</B>()</PRE>
<DL>
<DD>Get the expression that computes the key
<P>
<DD><DL>

<DT><B>Returns:</B><DD>the expression that computes the key</DL>
</DD>
</DL>
<HR>

<A NAME="getAtomicComparer()"><!-- --></A><H3>
getAtomicComparer</H3>
<PRE>
public <A HREF="../../../net/sf/saxon/expr/sort/AtomicComparer.html" title="interface in net.sf.saxon.expr.sort">AtomicComparer</A> <B>getAtomicComparer</B>()</PRE>
<DL>
<DD>Get the atomic comparer used
<P>
<DD><DL>

<DT><B>Returns:</B><DD>the atomic comparer</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>&nbsp;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
<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>&nbsp;visitor,
                            <A HREF="../../../net/sf/saxon/expr/parser/ExpressionVisitor.ContextItemType.html" title="class in net.sf.saxon.expr.parser">ExpressionVisitor.ContextItemType</A>&nbsp;contextItemType)</PRE>
<DL>
<DD>Type-check the expression
<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 expression after type-checking (potentially modified to add run-time
 checks and/or conversions)</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>&nbsp;visitor,
                           <A HREF="../../../net/sf/saxon/expr/parser/ExpressionVisitor.ContextItemType.html" title="class in net.sf.saxon.expr.parser">ExpressionVisitor.ContextItemType</A>&nbsp;contextItemType)</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</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="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>&nbsp;offer,
                          <A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A>&nbsp;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/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 promotion that is possible<DD><CODE>parent</CODE> - 
<DT><B>Returns:</B><DD>the promoted expression (or the original expression, unchanged)
<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="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>&lt;<A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A>&gt; <B>iterateSubExpressions</B>()</PRE>
<DL>
<DD>Get the immediate subexpressions of this expression
<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>the subexpressions, as an array</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>&nbsp;original,
                                    <A HREF="../../../net/sf/saxon/expr/Expression.html" title="class in net.sf.saxon.expr">Expression</A>&nbsp;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="computeCardinality()"><!-- --></A><H3>
computeCardinality</H3>
<PRE>
public int <B>computeCardinality</B>()</PRE>
<DL>
<DD>Get the static cardinality of this 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 cardinality. The method attempts to determine the case where the
 filter predicate is guaranteed to select at most one item from the sequence being filtered</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-significant. 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 static properties of the expression, as a bit-significant value</DL>
</DD>
</DL>
<HR>

<A NAME="equals(java.lang.Object)"><!-- --></A><H3>
equals</H3>
<PRE>
public boolean <B>equals</B>(<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>&nbsp;other)</PRE>
<DL>
<DD>Is this expression the same as another expression?
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><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></CODE> in class <CODE><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></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>other</CODE> - the expression to be compared with this one
<DT><B>Returns:</B><DD>true if the two expressions are statically equivalent</DL>
</DD>
</DL>
<HR>

<A NAME="hashCode()"><!-- --></A><H3>
hashCode</H3>
<PRE>
public int <B>hashCode</B>()</PRE>
<DL>
<DD>get HashCode for comparing two expressions
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><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></CODE> in class <CODE><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></CODE></DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>the hash code</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>&nbsp;context)
                              throws <A HREF="../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></PRE>
<DL>
<DD><B>Description copied from class: <CODE><A HREF="../../../net/sf/saxon/expr/Expression.html#effectiveBooleanValue(net.sf.saxon.expr.XPathContext)">Expression</A></CODE></B></DD>
<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="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>&nbsp;context)
                  throws <A HREF="../../../net/sf/saxon/trans/XPathException.html" title="class in net.sf.saxon.trans">XPathException</A></PRE>
<DL>
<DD><B>Description copied from class: <CODE><A HREF="../../../net/sf/saxon/expr/Expression.html#evaluateItem(net.sf.saxon.expr.XPathContext)">Expression</A></CODE></B></DD>
<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="computeDependencies()"><!-- --></A><H3>
computeDependencies</H3>
<PRE>
public int <B>computeDependencies</B>()</PRE>
<DL>
<DD>Determine which aspects of the context the expression depends on. The result is
 a bitwise-or'ed value composed from constants such as XPathContext.VARIABLES and
 XPathContext.CURRENT_NODE
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../net/sf/saxon/expr/Expression.html#computeDependencies()">computeDependencies</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 dependencies</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>&nbsp;destination)</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>destination</CODE> - the expression presenter used to display the structure</DL>
</DD>
</DL>
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