package client.net.sf.saxon.ce.functions;
import client.net.sf.saxon.ce.expr.LastPositionFinder;
import client.net.sf.saxon.ce.expr.XPathContext;
import client.net.sf.saxon.ce.om.Item;
import client.net.sf.saxon.ce.om.SequenceIterator;
import client.net.sf.saxon.ce.trans.XPathException;
import client.net.sf.saxon.ce.value.*;
/**
* Implementation of the fn:count function
*/
public class Count extends Aggregate {
public Count newInstance() {
return new Count();
}
/**
* Evaluate the function
*/
public Item evaluateItem(XPathContext context) throws XPathException {
SequenceIterator iter = argument[0].iterate(context);
return IntegerValue.makeIntegerValue(count(iter));
}
/**
* Get the number of items in a sequence identified by a SequenceIterator
* @param iter The SequenceIterator. This method moves the current position
* of the supplied iterator; if this isn't safe, make a copy of the iterator
* first by calling getAnother(). The supplied iterator must be positioned
* before the first item (there must have been no call on next()).
* @return the number of items in the underlying sequence
* @throws client.net.sf.saxon.ce.trans.XPathException if a failure occurs reading the input sequence
*/
public static int count(SequenceIterator iter) throws XPathException {
if ((iter.getProperties() & SequenceIterator.LAST_POSITION_FINDER) != 0) {
return ((LastPositionFinder)iter).getLastPosition();
} else {
int n = 0;
while (iter.next() != null) {
n++;
}
return n;
}
}
}
// 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.