Class TreeEnumeration

java.lang.Object
net.sf.saxon.tree.linked.TreeEnumeration
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
  • Field Details

    • start

      protected NodeImpl start
    • nextNode

      protected NodeImpl nextNode
    • nodeTest

      protected NodePredicate nodeTest
    • current

      protected NodeImpl current
    • position

      protected int position
  • Constructor Details

    • 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 originates
      nodeTest - test to be satisfied by the returned nodes, or null if all nodes are to be returned.
  • Method Details

    • 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
    • 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
    • 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 interface LookaheadIterator
      Returns:
      true if there are more items in the sequence
    • next

      public final NodeInfo next()
      Return the next node in the sequence
      Specified by:
      next in interface AxisIterator
      Specified by:
      next in interface SequenceIterator
      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.
    • 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 interface LookaheadIterator
      Returns:
      true if the LookaheadIterator.hasNext() method is available