package client.net.sf.saxon.ce.tree.iter;
import client.net.sf.saxon.ce.pattern.NodeTest;
import client.net.sf.saxon.ce.value.Value;
import client.net.sf.saxon.ce.trans.XPathException;
import client.net.sf.saxon.ce.om.NodeInfo;
import client.net.sf.saxon.ce.om.Item;
import client.net.sf.saxon.ce.om.SequenceIterator;
/**
* An iterator over nodes, that prepends a given node to the nodes
* returned by another iterator. Used to modify an iterator over axis A
* to one that iterates over A-OR-SELF.
*/
public class PrependIterator implements AxisIterator {
NodeInfo start;
AxisIterator base;
int position = 0;
public PrependIterator(NodeInfo start, AxisIterator base) {
this.start = start;
this.base = base;
}
/**
* Move to the next node, without returning it. Returns true if there is
* a next node, false if the end of the sequence has been reached. After
* calling this method, the current node may be retrieved using the
* current() function.
*/
public boolean moveNext() {
return (next() != null);
}
/**
* Get the next item in the sequence. <BR>
*
* @return the next Item. If there are no more nodes, return null.
*/
public Item next() {
if (position == 0) {
position = 1;
return start;
}
Item n = base.next();
if (n == null) {
position = -1;
} else {
position++;
}
return n;
}
/**
* Get the current item in the sequence.
*
* @return the current item, that is, the item most recently returned by
* next()
*/
public Item current() {
if (position() == 1) {
return start;
} else if (position < 1) {
return null;
} else {
return base.current();
}
}
/**
* Get the current position
*
* @return the position of the current item (the item most recently
* returned by next()), starting at 1 for the first node
*/
public int position() {
return position;
}
/**
* Return an iterator over an axis, starting at the current node.
*
* @param axis the axis to iterate over, using a constant such as
* {@link client.net.sf.saxon.ce.om.Axis#CHILD}
* @param test a predicate to apply to the nodes before returning them.
* @throws NullPointerException if there is no current node
*/
public AxisIterator iterateAxis(byte axis, NodeTest test) {
return ((NodeInfo)current()).iterateAxis(axis, test);
}
/**
* Return the atomized value of the current node.
*
* @return the atomized value.
* @throws NullPointerException if there is no current node
*/
public Value atomize() throws XPathException {
return ((NodeInfo)current()).getTypedValue();
}
/**
* Return the string value of the current node.
*
* @return the string value, as an instance of CharSequence.
* @throws NullPointerException if there is no current node
*/
public CharSequence getStringValue() {
return ((NodeInfo)current()).getStringValueCS();
}
/**
* Get another iterator over the same sequence of items, positioned at the
* start of the sequence
*
* @return a new iterator over the same sequence
*/
public SequenceIterator getAnother() {
return new PrependIterator(start, base);
}
/**
* Get properties of this iterator, as a bit-significant integer.
*
* @return the properties of this iterator. This will be some combination of
* properties such as {@link #GROUNDED}, {@link #LAST_POSITION_FINDER},
* and {@link #LOOKAHEAD}. It is always
* acceptable to return the value zero, indicating that there are no known special properties.
* It is acceptable for the properties of the iterator to change depending on its state.
*/
public int getProperties() {
return 0;
}
}
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is “Incompatible With Secondary Licenses”, as defined by the Mozilla Public License, v. 2.0.