Package net.sf.saxon.tree.linked
Class TreeEnumeration
- java.lang.Object
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- net.sf.saxon.tree.linked.TreeEnumeration
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- All Implemented Interfaces:
Closeable
,AutoCloseable
,SequenceIterator
,AxisIterator
,LookaheadIterator
- Direct Known Subclasses:
AncestorEnumeration
,ChildEnumeration
,FollowingEnumeration
,FollowingSiblingEnumeration
,PrecedingEnumeration
,PrecedingOrAncestorEnumeration
,PrecedingSiblingEnumeration
abstract class TreeEnumeration extends Object implements AxisIterator, LookaheadIterator
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Constructor Summary
Constructors Constructor Description TreeEnumeration(NodeImpl origin, NodePredicate nodeTest)
Create an axis enumeration for a given type and name of node, from a given origin node
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Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description protected void
advance()
Advance along the axis until a node is found that matches the required criteriaprotected boolean
conforms(NodeImpl node)
Test whether a node conforms to the node type and name constraints.boolean
hasNext()
Determine whether there are more items to come.NodeInfo
next()
Return the next node in the sequenceprotected abstract void
step()
Advance one step along the axis: the resulting node might not meet the required criteria for inclusionboolean
supportsHasNext()
Ask whether the hasNext() method can be called.-
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Methods inherited from interface net.sf.saxon.om.SequenceIterator
close, discharge
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Field Detail
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start
protected NodeImpl start
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nextNode
protected NodeImpl nextNode
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nodeTest
protected NodePredicate nodeTest
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current
protected NodeImpl current
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position
protected int position
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Constructor Detail
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TreeEnumeration
public TreeEnumeration(NodeImpl origin, NodePredicate nodeTest)
Create an axis enumeration for a given type and name of node, from a given origin node- Parameters:
origin
- the node from which the axis originatesnodeTest
- test to be satisfied by the returned nodes, or null if all nodes are to be returned.
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Method Detail
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conforms
protected boolean conforms(NodeImpl node)
Test whether a node conforms to the node type and name constraints. Note that this returns true if the supplied node is null, this is a way of terminating a loop.- Parameters:
node
- the node to be tested- Returns:
- true if the node matches the requested node type and name
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advance
protected final void advance()
Advance along the axis until a node is found that matches the required criteria
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step
protected abstract void step()
Advance one step along the axis: the resulting node might not meet the required criteria for inclusion
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hasNext
public boolean hasNext()
Determine whether there are more items to come. Note that this operation is stateless and it is not necessary (or usual) to call it before calling next(). It is used only when there is an explicit need to tell if we are at the last element.- Specified by:
hasNext
in interfaceLookaheadIterator
- Returns:
- true if there are more items in the sequence
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next
public final NodeInfo next()
Return the next node in the sequence- Specified by:
next
in interfaceAxisIterator
- Specified by:
next
in interfaceSequenceIterator
- Returns:
- the next item, or null if there are no more items. Once a call on next() has returned null, no further calls should be made. The preferred action for an iterator if subsequent calls on next() are made is to return null again, and all implementations within Saxon follow this rule.
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supportsHasNext
public boolean supportsHasNext()
Description copied from interface:LookaheadIterator
Ask whether the hasNext() method can be called. This method must be called before calling hasNext(), because some iterators implement this interface, but only support look-ahead under particular circumstances (this is usually because they delegate to another iterator)- Specified by:
supportsHasNext
in interfaceLookaheadIterator
- Returns:
- true if the
LookaheadIterator.hasNext()
method is available
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