jd.xml.xpath.expr.path
Class FilteredLocationStep

java.lang.Object
  jd.xml.xpath.expr.ExpressionImpl
      jd.xml.xpath.expr.NodeSetExpression
          jd.xml.xpath.expr.path.LocationStep
              jd.xml.xpath.expr.path.FilteredLocationStep

All Implemented Interfaces:

Expression

public class FilteredLocationStep

extends LocationStep

A FilteredLocationStep is a LocationStep with a simple filter predicate that uses axis iterators for evaluation and is therefore faster than a heavyweight PredicateExpression. - and a forward axis or a reverse axis and a unique filter expression The implementation uses axis iterators and applies the predicate filter directly to all iterated nodes which pass the nodetest (instead of evaluating the pure location step and then filtering the returned node-set with a PredicateExpression. Because iterators are used the context size is not known and therefore the filter expression may not contain last().

Field Summary

Fields inherited from class jd.xml.xpath.expr.path.LocationStep

axis_, maxAxisResultSize_, nodeTest_

Fields inherited from interface jd.xml.xpath.expr.Expression

DEP_CONTEXT_NODE, DEP_CONTEXT_POSITION, DEP_CONTEXT_SIZE, DEP_CONTEXT_STATIC, DEP_NONE, DEP_UNKNOWN

Method Summary

void	accept(ExpressionVisitor visitor) Accept a ExpressionVisitor.
static FilteredLocationStep	create(SimpleLocationStep step, Expression filter) Create a FilteredLocationStep if possible
int	getContextDependencies() Return a bitfield indicating the expression dependencies.
int	getMaxResultSize() Return the maximum size of the returned NodeSet or 0 if not known.
void	getNodes(XPathContext context, XMutableNodeSet nodeSet) Evaluate the FilteredLocationStep.
XNodeSet	toNodeSet(XPathContext context, int nodeSetOrdering) Evaluate the FilteredLocationStep.

Methods inherited from class jd.xml.xpath.expr.path.LocationStep

getAxis, getNodeTest

Methods inherited from class jd.xml.xpath.expr.NodeSetExpression

canCreateModelWalker, getMaxResultSize, getMinResultSize, getMinResultSize, getModelWalker, getResultType, toBooleanValue, toNumberValue, toStringValue, toXObject

Methods inherited from class jd.xml.xpath.expr.ExpressionImpl

hasContextDependencies, isUniqueFilter, matchesFilter, toNode, toString

Methods inherited from class java.lang.Object

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

Method Detail

create

public static FilteredLocationStep create(SimpleLocationStep step,
                                          Expression filter)

Create a FilteredLocationStep if possible

Returns:

the step or null if the axis and filter don't allow to apply the FilteredLocationStep.

getMaxResultSize

public int getMaxResultSize()

Description copied from class: NodeSetExpression

Return the maximum size of the returned NodeSet or 0 if not known. The default implementation returns 0.

Overrides:

getMaxResultSize in class LocationStep

toNodeSet

public XNodeSet toNodeSet(XPathContext context,
                          int nodeSetOrdering)

Evaluate the FilteredLocationStep.

Specified by:

toNodeSet in interface Expression

Overrides:

toNodeSet in class ExpressionImpl

getNodes

public void getNodes(XPathContext context,
                     XMutableNodeSet nodeSet)

Evaluate the FilteredLocationStep.

Specified by:

getNodes in class LocationStep

Parameters:

context - the evaluation context

nodeSet - a NodeSet where to store the resulting nodes

getContextDependencies

public int getContextDependencies()

Return a bitfield indicating the expression dependencies.

Specified by:

getContextDependencies in interface Expression

Overrides:

getContextDependencies in class LocationStep

accept

public void accept(ExpressionVisitor visitor)

Description copied from interface: Expression

Accept a ExpressionVisitor.

Specified by:

accept in interface Expression

Overrides:

accept in class LocationStep