net.sf.saxon.functions

Class DistinctValues

java.lang.Object

net.sf.saxon.expr.ComputedExpression

net.sf.saxon.expr.FunctionCall

net.sf.saxon.functions.SystemFunction

net.sf.saxon.functions.CollatingFunction

net.sf.saxon.functions.DistinctValues

All Implemented Interfaces:

Serializable, SourceLocator, Container, Expression, InstructionInfoProvider

public class DistinctValues
extends CollatingFunction

The XPath 2.0 distinct-values() function

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
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

Constructors

Constructor and Description
DistinctValues()

Method Summary

Modifier and Type	Method and Description
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