net.sf.saxon.functions
Class DistinctValues

java.lang.Object
  extended bynet.sf.saxon.expr.ComputedExpression
      extended bynet.sf.saxon.expr.FunctionCall
          extended bynet.sf.saxon.functions.SystemFunction
              extended bynet.sf.saxon.functions.CollatingFunction
                  extended bynet.sf.saxon.functions.DistinctValues
All Implemented Interfaces:
Container, Expression, InstructionInfoProvider, java.io.Serializable, javax.xml.transform.SourceLocator

public class DistinctValues
extends CollatingFunction

The XPath 2.0 distinct-values() function

See Also:
Serialized Form

Nested Class Summary
static class DistinctValues.DistinctIterator
          Iterator class to return the distinct values in a sequence
 
Field Summary
 
Fields inherited from class net.sf.saxon.functions.CollatingFunction
conversionContext
 
Fields inherited from class net.sf.saxon.functions.SystemFunction
operation
 
Fields inherited from class net.sf.saxon.expr.FunctionCall
argument
 
Fields inherited from class net.sf.saxon.expr.ComputedExpression
locationId, staticProperties
 
Fields inherited from interface net.sf.saxon.expr.Expression
EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD
 
Constructor Summary
DistinctValues()
           
 
Method Summary
protected  AtomicSortComparer getAtomicSortComparer(int arg, XPathContext context)
          Get a AtomicSortComparer that can be used to compare values
 SequenceIterator iterate(XPathContext context)
          Evaluate the function to return an iteration of selected values or nodes.
 
Methods inherited from class net.sf.saxon.functions.CollatingFunction
checkArguments, getAtomicComparer, getCollator, preEvaluateCollation
 
Methods inherited from class net.sf.saxon.functions.SystemFunction
addContextDocumentArgument, computeCardinality, computeSpecialProperties, display, getDetails, getErrorCodeForTypeErrors, getItemType, getRequiredType, main, makeSystemFunction, setDetails, useContextItemAsDefault
 
Methods inherited from class net.sf.saxon.expr.FunctionCall
checkArgumentCount, getDisplayName, getFunctionNameCode, getNumberOfArguments, iterateSubExpressions, optimize, preEvaluate, promote, setArguments, setFunctionNameCode, simplify, simplifyArguments, typeCheck
 
Methods inherited from class net.sf.saxon.expr.ComputedExpression
adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, dynamicError, effectiveBooleanValue, evaluateAsString, evaluateItem, getCardinality, getColumnNumber, getConstructType, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getInstructionInfo, getIntrinsicDependencies, getLineNumber, getLocationId, getLocationProvider, getParentExpression, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasBadParentPointer, markTailFunctionCalls, process, resetStaticProperties, setLocationId, setParentExpression, suppressValidation, typeError, typeError
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

DistinctValues

public DistinctValues()
Method Detail

iterate

public SequenceIterator iterate(XPathContext context)
                         throws XPathException
Evaluate the function to return an iteration of selected values or nodes.

Specified by:
iterate in interface Expression
Overrides:
iterate in class ComputedExpression
Parameters:
context - supplies the context for evaluation
Returns:
a SequenceIterator that can be used to iterate over the result of the expression
Throws:
XPathException - if any dynamic error occurs evaluating the expression

getAtomicSortComparer

protected AtomicSortComparer getAtomicSortComparer(int arg,
                                                   XPathContext context)
                                            throws XPathException
Get a AtomicSortComparer that can be used to compare values

Parameters:
arg - the position of the argument (starting at 0) containing the collation name. If this argument was not supplied, the default collation is used
context - The dynamic evaluation context.
Throws:
XPathException