package client.net.sf.saxon.ce.expr;
import client.net.sf.saxon.ce.om.Item;
import client.net.sf.saxon.ce.om.SequenceIterator;
import client.net.sf.saxon.ce.trans.XPathException;
/**
* A FirstItemExpression returns the first item in the sequence returned by a given
* base expression
*/
public final class FirstItemExpression extends SingleItemFilter {
/**
* Constructor
* @param base A sequence expression denoting sequence whose first item is to be returned
*/
public FirstItemExpression(Expression base) {
operand = base;
adoptChildExpression(base);
computeStaticProperties();
}
/**
* Evaluate the expression
*/
public Item evaluateItem(XPathContext context) throws XPathException {
SequenceIterator iter = operand.iterate(context);
return iter.next();
}
}
// 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.