Package org.apache.xpath.axes
Class FilterExprWalker
- java.lang.Object
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- org.apache.xpath.Expression
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- org.apache.xpath.patterns.NodeTest
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- org.apache.xpath.axes.PredicatedNodeTest
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- org.apache.xpath.axes.AxesWalker
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- org.apache.xpath.axes.FilterExprWalker
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- All Implemented Interfaces:
java.io.Serializable
,java.lang.Cloneable
,javax.xml.transform.SourceLocator
,PathComponent
,SubContextList
,ExpressionNode
,ExpressionOwner
,XPathVisitable
public class FilterExprWalker extends AxesWalker
Walker for the OP_VARIABLE, or OP_EXTFUNCTION, or OP_FUNCTION, or OP_GROUP, op codes.- See Also:
- XPath FilterExpr descriptions, Serialized Form
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Field Summary
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Fields inherited from class org.apache.xpath.patterns.NodeTest
SCORE_NODETEST, SCORE_NONE, SCORE_NSWILD, SCORE_OTHER, SCORE_QNAME, SHOW_BYFUNCTION, SUPPORTS_PRE_STRIPPING, WILD
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Constructor Summary
Constructors Constructor Description FilterExprWalker(WalkingIterator locPathIterator)
Construct a FilterExprWalker using a LocPathIterator.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description short
acceptNode(int n)
This method needs to override AxesWalker.acceptNode because FilterExprWalkers don't need to, and shouldn't, do a node test.void
callPredicateVisitors(XPathVisitor visitor)
This will traverse the heararchy, calling the visitor for each member.java.lang.Object
clone()
Get a cloned FilterExprWalker.boolean
deepEquals(Expression expr)
Compare this object with another object and see if they are equal, include the sub heararchy.void
detach()
Detaches the walker from the set which it iterated over, releasing any computational resources and placing the iterator in the INVALID state.void
fixupVariables(java.util.Vector vars, int globalsSize)
This function is used to fixup variables from QNames to stack frame indexes at stylesheet build time.int
getAnalysisBits()
Get the analysis bits for this walker, as defined in the WalkerFactory.int
getAxis()
Returns the axis being iterated, if it is known.Expression
getInnerExpression()
Get the inner contained expression of this filter.int
getLastPos(XPathContext xctxt)
Get the index of the last node that can be itterated to.int
getNextNode()
Moves theTreeWalker
to the next visible node in document order relative to the current node, and returns the new node.void
init(Compiler compiler, int opPos, int stepType)
Init a FilterExprWalker.boolean
isDocOrdered()
Returns true if all the nodes in the iteration well be returned in document order.void
setInnerExpression(Expression expr)
Set the inner contained expression of this filter.void
setRoot(int root)
Set the root node of the TreeWalker.-
Methods inherited from class org.apache.xpath.axes.AxesWalker
callVisitors, getCurrentNode, getDTM, getExpression, getNextWalker, getPrevWalker, getRoot, nextNode, setDefaultDTM, setExpression, setNextWalker, setPrevWalker, wi
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Methods inherited from class org.apache.xpath.axes.PredicatedNodeTest
canTraverseOutsideSubtree, getLocPathIterator, getPredicate, getPredicateCount, getPredicateIndex, getProximityPosition, getProximityPosition, initProximityPosition, isReverseAxes, resetProximityPositions, setLocPathIterator, setPredicateCount
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Methods inherited from class org.apache.xpath.patterns.NodeTest
debugWhatToShow, execute, execute, execute, getDefaultScore, getLocalName, getNamespace, getNodeTypeTest, getStaticScore, getWhatToShow, initNodeTest, initNodeTest, setLocalName, setNamespace, setStaticScore, setWhatToShow
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Methods inherited from class org.apache.xpath.Expression
asIterator, asIteratorRaw, asNode, assertion, bool, error, execute, executeCharsToContentHandler, exprAddChild, exprGetChild, exprGetNumChildren, exprGetParent, exprSetParent, getColumnNumber, getExpressionOwner, getLineNumber, getPublicId, getSystemId, isNodesetExpr, isStableNumber, num, warn, xstr
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Constructor Detail
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FilterExprWalker
public FilterExprWalker(WalkingIterator locPathIterator)
Construct a FilterExprWalker using a LocPathIterator.- Parameters:
locPathIterator
- non-null reference to the parent iterator.
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Method Detail
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init
public void init(Compiler compiler, int opPos, int stepType) throws javax.xml.transform.TransformerException
Init a FilterExprWalker.- Overrides:
init
in classAxesWalker
- Parameters:
compiler
- non-null reference to the Compiler that is constructing.opPos
- positive opcode position for this step.stepType
- The type of step.- Throws:
javax.xml.transform.TransformerException
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detach
public void detach()
Detaches the walker from the set which it iterated over, releasing any computational resources and placing the iterator in the INVALID state.- Overrides:
detach
in classAxesWalker
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setRoot
public void setRoot(int root)
Set the root node of the TreeWalker.- Overrides:
setRoot
in classAxesWalker
- Parameters:
root
- non-null reference to the root, or starting point of the query.
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clone
public java.lang.Object clone() throws java.lang.CloneNotSupportedException
Get a cloned FilterExprWalker.- Overrides:
clone
in classAxesWalker
- Returns:
- A new FilterExprWalker that can be used without mutating this one.
- Throws:
java.lang.CloneNotSupportedException
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acceptNode
public short acceptNode(int n)
This method needs to override AxesWalker.acceptNode because FilterExprWalkers don't need to, and shouldn't, do a node test.- Overrides:
acceptNode
in classPredicatedNodeTest
- Parameters:
n
- The node to check to see if it passes the filter or not.- Returns:
- a constant to determine whether the node is accepted, rejected, or skipped, as defined above .
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getNextNode
public int getNextNode()
Moves theTreeWalker
to the next visible node in document order relative to the current node, and returns the new node. If the current node has no next node, or if the search for nextNode attempts to step upward from the TreeWalker's root node, returnsnull
, and retains the current node.- Returns:
- The new node, or
null
if the current node has no next node in the TreeWalker's logical view.
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getLastPos
public int getLastPos(XPathContext xctxt)
Get the index of the last node that can be itterated to.- Specified by:
getLastPos
in interfaceSubContextList
- Overrides:
getLastPos
in classAxesWalker
- Parameters:
xctxt
- XPath runtime context.- Returns:
- the index of the last node that can be itterated to.
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fixupVariables
public void fixupVariables(java.util.Vector vars, int globalsSize)
This function is used to fixup variables from QNames to stack frame indexes at stylesheet build time.- Overrides:
fixupVariables
in classPredicatedNodeTest
- Parameters:
vars
- List of QNames that correspond to variables. This list should be searched backwards for the first qualified name that corresponds to the variable reference qname. The position of the QName in the vector from the start of the vector will be its position in the stack frame (but variables above the globalsTop value will need to be offset to the current stack frame).
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getInnerExpression
public Expression getInnerExpression()
Get the inner contained expression of this filter.
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setInnerExpression
public void setInnerExpression(Expression expr)
Set the inner contained expression of this filter.
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getAnalysisBits
public int getAnalysisBits()
Get the analysis bits for this walker, as defined in the WalkerFactory.- Specified by:
getAnalysisBits
in interfacePathComponent
- Overrides:
getAnalysisBits
in classAxesWalker
- Returns:
- One of WalkerFactory#BIT_DESCENDANT, etc.
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isDocOrdered
public boolean isDocOrdered()
Returns true if all the nodes in the iteration well be returned in document order. Warning: This can only be called after setRoot has been called!- Overrides:
isDocOrdered
in classAxesWalker
- Returns:
- true as a default.
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getAxis
public int getAxis()
Returns the axis being iterated, if it is known.- Overrides:
getAxis
in classAxesWalker
- Returns:
- Axis.CHILD, etc., or -1 if the axis is not known or is of multiple types.
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callPredicateVisitors
public void callPredicateVisitors(XPathVisitor visitor)
This will traverse the heararchy, calling the visitor for each member. If the called visitor method returns false, the subtree should not be called.- Overrides:
callPredicateVisitors
in classPredicatedNodeTest
- Parameters:
visitor
- The visitor whose appropriate method will be called.
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deepEquals
public boolean deepEquals(Expression expr)
Description copied from class:Expression
Compare this object with another object and see if they are equal, include the sub heararchy.- Overrides:
deepEquals
in classAxesWalker
- Parameters:
expr
- Another expression object.- Returns:
- true if this objects class and the expr object's class are the same, and the data contained within both objects are considered equal.
- See Also:
Expression.deepEquals(Expression)
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