net.sf.saxon.expr
Class PositionIterator

java.lang.Object
  extended by net.sf.saxon.expr.PositionIterator
All Implemented Interfaces:
LookaheadIterator, SequenceIterator

public class PositionIterator
extends Object
implements SequenceIterator, LookaheadIterator

A PositionIterator selects a subsequence of a sequence


Method Summary
 Item current()
          Get the current value in the sequence (the one returned by the most recent call on next()).
 SequenceIterator getAnother()
          Get another iterator to return the same nodes
 boolean hasNext()
          Test whether there are any more items available in the enumeration
static SequenceIterator make(SequenceIterator base, int min, int max)
          Static factory method.
 Item next()
          Get the next item if there is one
 int position()
          Get the current position.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

make

public static SequenceIterator make(SequenceIterator base,
                                    int min,
                                    int max)
                             throws XPathException
Static factory method. Creates a PositionIterator, unless the base Iterator is an ArrayIterator, in which case it optimizes by creating a new ArrayIterator directly over the underlying array. This optimization is important when doing recursion over a node-set using repeated calls of $nodes[position()>1]

Throws:
XPathException

hasNext

public boolean hasNext()
Test whether there are any more items available in the enumeration

Specified by:
hasNext in interface LookaheadIterator
Returns:
true if there are more nodes

next

public Item next()
          throws XPathException
Get the next item if there is one

Specified by:
next in interface SequenceIterator
Returns:
the next item, or null if there are no more items.
Throws:
XPathException - if an error occurs retrieving the next item

current

public Item current()
Description copied from interface: SequenceIterator
Get the current value in the sequence (the one returned by the most recent call on next()). This will be null before the first call of next().

Specified by:
current in interface SequenceIterator
Returns:
the current item, the one most recently returned by a call on next(); or null, if next() has not been called, or if the end of the sequence has been reached.

position

public int position()
Description copied from interface: SequenceIterator
Get the current position. This will be zero before the first call on next(), otherwise it will be the number of times that next() has been called.

Specified by:
position in interface SequenceIterator
Returns:
the current position, the position of the item returned by the most recent call of next()

getAnother

public SequenceIterator getAnother()
                            throws XPathException
Get another iterator to return the same nodes

Specified by:
getAnother in interface SequenceIterator
Returns:
a SequenceIterator that iterates over the same items, positioned before the first item
Throws:
XPathException - if any error occurs