package net.sf.saxon.expr;
import net.sf.saxon.om.Item;
import net.sf.saxon.om.SequenceIterator;
import net.sf.saxon.om.AxisIterator;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.value.Value;
import net.sf.saxon.value.AtomicValue;
/**
* This iterator returns a sequence of atomic values, the result of atomizing the sequence
* of nodes returned by an underlying AxisIterator.
*/
public final class AxisAtomizingIterator implements SequenceIterator {
private AxisIterator base;
private SequenceIterator results = null;
private AtomicValue current = null;
private int position = 0;
/**
* Construct an atomizing iterator
* @param base the base iterator (whose nodes are to be atomized)
*/
public AxisAtomizingIterator(AxisIterator base) {
this.base = base;
}
public Item next() throws XPathException {
AtomicValue nextItem;
while (true) {
if (results != null) {
nextItem = (AtomicValue)results.next();
if (nextItem != null) {
break;
} else {
results = null;
}
}
// Avoid calling next() to materialize the NodeInfo object
if (base.moveNext()) {
Value atomized = base.atomize();
if (atomized instanceof AtomicValue) {
// common case (the atomized value of the node is a single atomic value)
results = null;
nextItem = (AtomicValue)atomized;
break;
} else {
results = atomized.iterate();
nextItem = (AtomicValue)results.next();
if (nextItem == null) {
results = null;
} else {
break;
}
}
// now go round the loop to get the next item from the base sequence
} else {
results = null;
current = null;
position = -1;
return null;
}
}
current = nextItem;
position++;
return nextItem;
}
public Item current() {
return current;
}
public int position() {
return position;
}
public SequenceIterator getAnother() {
// System.err.println(this + " getAnother() ");
AxisIterator newBase = (AxisIterator)base.getAnother();
AxisAtomizingIterator m = new AxisAtomizingIterator(newBase);
return m;
}
/**
* 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 net.sf.saxon.om.SequenceIterator#GROUNDED}, {@link net.sf.saxon.om.SequenceIterator#LAST_POSITION_FINDER},
* and {@link net.sf.saxon.om.SequenceIterator#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;
}
}
//
// The contents of this file are subject to the Mozilla Public License Version 1.0 (the "License");
// you may not use this file except in compliance with the License. You may obtain a copy of the
// License at http://www.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied.
// See the License for the specific language governing rights and limitations under the License.
//
// The Original Code is: all this file.
//
// The Initial Developer of the Original Code is Michael H. Kay
//
// Portions created by (your name) are Copyright (C) (your legal entity). All Rights Reserved.
//
// Contributor(s): none.
//