package org.pdf4j.saxon.evpull;
import org.pdf4j.saxon.om.Item;
import org.pdf4j.saxon.om.SequenceIterator;
import org.pdf4j.saxon.trans.XPathException;
/**
* MappingIterator merges a sequence of sequences into a single sequence.
* It takes as inputs an iteration, and a mapping function to be
* applied to each Item returned by that iteration. The mapping function itself
* returns another iteration. The result is an iteration of iterators. To convert this
* int a single flat iterator over a uniform sequence of events, the result must be wrapped
* in an {@link EventStackIterator}<p>
*/
public final class EventMappingIterator implements EventIterator {
private SequenceIterator base;
private EventMappingFunction action;
/**
* Construct a MappingIterator that will apply a specified MappingFunction to
* each Item returned by the base iterator.
* @param base the base iterator
* @param action the mapping function to be applied
*/
public EventMappingIterator(SequenceIterator base, EventMappingFunction action) {
this.base = base;
this.action = action;
}
public PullEvent next() throws XPathException {
Item nextSource = base.next();
return (nextSource == null ? null : action.map(nextSource));
}
/**
* Determine whether the EventIterator returns a flat sequence of events, or whether it can return
* nested event iterators
*
* @return true if the next() method is guaranteed never to return an EventIterator
*/
public boolean isFlatSequence() {
return false;
}
}
//
// 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.
//
// Contributor(s):
//