com.saxonica.ee.pattern.preconditions

Class IndexMatcher

java.lang.Object

net.sf.saxon.trans.RuleSearchState

com.saxonica.ee.pattern.preconditions.Matcher

com.saxonica.ee.pattern.preconditions.IndexMatcher

All Implemented Interfaces:

SequenceIterator

public class IndexMatcher
extends Matcher
implements SequenceIterator

Description for class

Field Summary

Fields inherited from class net.sf.saxon.trans.RuleSearchState

calls, mode, startTime

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

ATOMIZING, GROUNDED, LAST_POSITION_FINDER, LOOKAHEAD

Constructor Summary

Constructors

Constructor and Description
IndexMatcher(ComparisonPredicateIndex comparisonPredicateIndex, SimpleMode mode)
IndexMatcher(RealPreconditions p, SimpleMode mode)

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Close the iterator.
SequenceIterator	getAnother() Get another SequenceIterator that iterates over the same items as the original, but which is repositioned at the start of the sequence.
int	getProperties() Get properties of this iterator, as a bit-significant integer.
ObjectValue<Rule>	next() Return the next rule that matches the context item.
void	prepareEval(Item item, XPathContext context) Prepare to evaluate this rule indexation, by recording the context item that is the subject of the template match and initialising the iterator to work across the indicies

Methods inherited from class com.saxonica.ee.pattern.preconditions.Matcher

check, getFailure, getStats, getSuccess, otherProperties, reset, resetBasic

Methods inherited from class net.sf.saxon.trans.RuleSearchState

count, getCalls

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

IndexMatcher

public IndexMatcher(ComparisonPredicateIndex comparisonPredicateIndex,
            SimpleMode mode)

IndexMatcher

public IndexMatcher(RealPreconditions p,
            SimpleMode mode)

Method Detail

prepareEval

public void prepareEval(Item item,
               XPathContext context)
                 throws XPathException

Prepare to evaluate this rule indexation, by recording the context item that is the subject of the template match and initialising the iterator to work across the indicies

Parameters:

item - the context item for the template match

context - the dynamic XPath context

Throws:

XPathException

next

public ObjectValue<Rule> next()

Return the next rule that matches the context item.

Specified by:

next in interface SequenceIterator

Returns:

an ObjectValue wrapping the rule, or null if there is no further rule matching

close

public void close()

Description copied from interface: SequenceIterator

Close the iterator. This indicates to the supplier of the data that the client does not require any more items to be delivered by the iterator. This may enable the supplier to release resources. After calling close(), no further calls on the iterator should be made; if further calls are made, the effect of such calls is undefined.

(Currently, closing an iterator is important only when the data is being "pushed" in another thread. Closing the iterator terminates that thread and means that it needs to do no additional work. Indeed, failing to close the iterator may cause the push thread to hang waiting for the buffer to be emptied.)

Specified by:

close in interface SequenceIterator

getAnother

public SequenceIterator getAnother()
                            throws XPathException

Description copied from interface: SequenceIterator

Get another SequenceIterator that iterates over the same items as the original, but which is repositioned at the start of the sequence.

This method allows access to all the items in the sequence without disturbing the current position of the iterator. Internally, its main use is in evaluating the last() function.

This method does not change the state of the iterator.

Some implementations of this method may regenerate the input sequence, creating new nodes with different identity from the original. This is not recommended, but is hard to prevent. This causes no problem for the primary usage of this method to support the last() function, but it has been known to cause trouble in other situations.

Specified by:

getAnother in interface SequenceIterator

Returns:

a SequenceIterator that iterates over the same items, positioned before the first item

Throws:

XPathException - if any error occurs

getProperties

public int getProperties()

Description copied from interface: SequenceIterator

Get properties of this iterator, as a bit-significant integer.

Specified by:

getProperties in interface SequenceIterator

Returns:

the properties of this iterator. This will be some combination of properties such as SequenceIterator.GROUNDED, SequenceIterator.LAST_POSITION_FINDER, and SequenceIterator.LOOKAHEAD. It is always acceptable to return the value zero, indicating that there are no known special properties. It is acceptable for the properties of the iterator to change depending on its state.