com.icl.saxon.tree
Class TreeEnumeration

java.lang.Object
  com.icl.saxon.tree.TreeEnumeration

All Implemented Interfaces:

LastPositionFinder, AxisEnumeration, NodeEnumeration

Direct Known Subclasses:

AncestorEnumeration, ChildEnumeration, DescendantEnumeration, FollowingEnumeration, FollowingSiblingEnumeration, NamespaceEnumeration, PrecedingEnumeration, PrecedingOrAncestorEnumeration, PrecedingSiblingEnumeration

abstract class TreeEnumeration
extends java.lang.Object
implements AxisEnumeration

Field Summary

protected int	last
protected NodeImpl	next
protected NodeTest	nodeTest
protected NodeImpl	start

Constructor Summary

TreeEnumeration(NodeImpl origin, NodeTest nodeTest)
Create an axis enumeration for a given type and name of node, from a given origin node

Method Summary

protected void	advance() Advance along the axis until a node is found that matches the required criteria
protected boolean	conforms(NodeImpl node) Test whether a node conforms to the node type and name constraints.
protected int	count() Count the number of nodes in the enumeration.
boolean	hasMoreElements() Determine if there are more nodes to be returned
boolean	isPeer() Determine if the nodes are guaranteed to be peers (i.e.
boolean	isReverseSorted() Determine if the nodes are guaranteed to be sorted in reverse document order
boolean	isSorted() Determine if the nodes are guaranteed to be sorted in document order
NodeInfo	nextElement() Return the next node in the enumeration
protected abstract void	step() Advance one step along the axis: the resulting node might not meet the required criteria for inclusion

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.icl.saxon.om.AxisEnumeration

getLastPosition

Field Detail

start

protected NodeImpl start

next

protected NodeImpl next

nodeTest

protected NodeTest nodeTest

last

protected int last

Constructor Detail

TreeEnumeration

public TreeEnumeration(NodeImpl origin,
                       NodeTest nodeTest)

Create an axis enumeration for a given type and name of node, from a given origin node

Method Detail

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.

advance

protected final void advance()

Advance along the axis until a node is found that matches the required criteria

step

protected abstract void step()

Advance one step along the axis: the resulting node might not meet the required criteria for inclusion

hasMoreElements

public final boolean hasMoreElements()

Determine if there are more nodes to be returned

Specified by:

hasMoreElements in interface AxisEnumeration

Specified by:

hasMoreElements in interface NodeEnumeration

Returns:

true if there are more nodes

nextElement

public final NodeInfo nextElement()

Return the next node in the enumeration

Specified by:

nextElement in interface AxisEnumeration

Specified by:

nextElement in interface NodeEnumeration

Returns:

the next NodeInfo

isSorted

public boolean isSorted()

Determine if the nodes are guaranteed to be sorted in document order

Specified by:

isSorted in interface NodeEnumeration

Returns:

true if the nodes are guaranteed to be in document order.

isReverseSorted

public boolean isReverseSorted()

Determine if the nodes are guaranteed to be sorted in reverse document order

Specified by:

isReverseSorted in interface NodeEnumeration

Returns:

true if the nodes are guaranteed to be in document order.

isPeer

public boolean isPeer()

Determine if the nodes are guaranteed to be peers (i.e. no node is a descendant of another node)

Specified by:

isPeer in interface NodeEnumeration

count

protected int count()

Count the number of nodes in the enumeration. This is used to support finding the last() position. Note that it must be used on a "clean" enumeration: the enumeration must be positioned at the start, and is left positioned at the end.