Package com.icl.saxon.expr

Class LookaheadEnumerator

  • All Implemented Interfaces:
    LastPositionFinder, NodeEnumeration
    public class LookaheadEnumerator
extends java.lang.Object
implements NodeEnumeration, LastPositionFinder
    A LookaheadEnumerator passes the nodes from a base enumerator throgh unchanged. The complication is that on request, it must determine the value of the last() position, which requires a lookahead. A LookaheadEnumerator should only be used to wrap a NodeEnumeration that cannot determine the last() position for itself, i.e. one that is not a LastPositionFinder.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      int getLastPosition()
      Do lookahead to find the last position, if required
      boolean hasMoreElements()
      Determine whether there are any more nodes to hand to the client
      boolean isPeer()
      Determine whether the nodes are guaranteed to be peers
      boolean isReverseSorted()
      Determine whether the nodes returned by this enumeration are known to be in reverse document order.
      boolean isSorted()
      Determine whether the nodes are guaranteed to be in document order
      NodeInfo nextElement()
      Hand the next node to the client

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • LookaheadEnumerator

        public LookaheadEnumerator​(NodeEnumeration base)
        Constructor
        Parameters:
        base - An NodeEnumerator that delivers the nodes, but that cannot determine the last position count.

    • Method Detail

      • hasMoreElements

        public boolean hasMoreElements()
        Determine whether there are any more nodes to hand to the client
        Specified by:
        hasMoreElements in interface NodeEnumeration
        Returns:
        true if there are more nodes

      • isSorted

        public boolean isSorted()
        Determine whether the nodes are guaranteed to be 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()
        Description copied from interface: NodeEnumeration
        Determine whether the nodes returned by this enumeration are known to be 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 whether the nodes are guaranteed to be peers
        Specified by:
        isPeer in interface NodeEnumeration