com.saxonica.extra
Class IndexedClosure

java.lang.Object
  net.sf.saxon.value.Value
      net.sf.saxon.value.Closure
          net.sf.saxon.value.MemoClosure
              com.saxonica.extra.IndexedClosure

All Implemented Interfaces:

Expression, java.io.Serializable, ValueRepresentation

public class IndexedClosure

extends MemoClosure

A subclass of MemoClosure that allows the construction of one or more indexes to provide rapid access to the items in the sequence

See Also:

Serialized Form

Nested Class Summary

Nested classes inherited from class net.sf.saxon.value.MemoClosure

MemoClosure.ProgressiveIterator

Field Summary

Fields inherited from class net.sf.saxon.value.MemoClosure

EMPTY, state

Fields inherited from class net.sf.saxon.value.Closure

depth, expression, inputIterator, savedXPathContext

Fields inherited from class net.sf.saxon.value.Value

EMPTY_CLASS_ARRAY

Fields inherited from interface net.sf.saxon.expr.Expression

EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD

Fields inherited from interface net.sf.saxon.om.ValueRepresentation

EMPTY_VALUE_ARRAY

Constructor Summary

IndexedClosure()

Method Summary

java.util.HashMap	buildIndex(Expression use, XPathContext context) Build an index over the items in the sequence
SequenceIterator	findItems(Expression use, SequenceIterator values, XPathContext context) Retrieve items that match a given index value
boolean	isIndexable() Determine wither this Closure is indexable
Value	materialize() Return a value containing all the items in the sequence returned by this SequenceIterator

Methods inherited from class net.sf.saxon.value.MemoClosure

getLength, isFullyRead, itemAt, iterate, process

Methods inherited from class net.sf.saxon.value.Closure

display, getCardinality, getImplementationMethod, getItemType, getSpecialProperties, make, makeIteratorClosure, reduce

Methods inherited from class net.sf.saxon.value.Value

asItem, asIterator, asValue, checkPermittedContents, collapseWhitespace, convert, convertJavaObjectToXPath, convertToJava, effectiveBooleanValue, equals, evaluateAsString, evaluateItem, getDependencies, getIterator, getParentExpression, getStringValue, hashCode, iterateSubExpressions, makeQNameValue, normalizeWhitespace, optimize, promote, schemaEquals, simplify, stringToNumber, toString, trimWhitespace, typeCheck

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

IndexedClosure

public IndexedClosure()

Method Detail

isIndexable

public boolean isIndexable()

Determine wither this Closure is indexable

Overrides:

isIndexable in class Closure

buildIndex

public java.util.HashMap buildIndex(Expression use,
                                    XPathContext context)
                             throws XPathException

Build an index over the items in the sequence

Parameters:

use - the expression returning the atomic values to act as the indexing keys

context - dynamic context for evaluating the indexing expression

Throws:

XPathException

findItems

public SequenceIterator findItems(Expression use,
                                  SequenceIterator values,
                                  XPathContext context)
                           throws XPathException

Retrieve items that match a given index value

Throws:

XPathException

materialize

public Value materialize()
                  throws XPathException

Return a value containing all the items in the sequence returned by this SequenceIterator

Overrides:

materialize in class MemoClosure

Returns:

the corresponding value

Throws:

XPathException