org.exist.xquery.modules.ngram.utils.NodeSets Maven / Gradle / Ivy
/*
* eXist-db Open Source Native XML Database
* Copyright (C) 2001 The eXist-db Authors
*
* [email protected]
* http://www.exist-db.org
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
package org.exist.xquery.modules.ngram.utils;
import org.exist.dom.persistent.ExtArrayNodeSet;
import org.exist.dom.persistent.NodeProxy;
import org.exist.dom.persistent.NodeSet;
import org.exist.dom.persistent.NodeSetIterator;
import org.exist.xquery.XPathException;
import java.util.function.Function;
public final class NodeSets {
private NodeSets() {
}
/**
* Builds a new NodeSet by applying a function to all NodeProxys of the supplied NodeSet and returning all non-null
* results.
*
* @param nodes
* the NodeSet containig the NodeProys to be transformed
* @param transform
* the function to be applied to all NodeProxys in nodes
* @return a new NodeSet containing the non-null results of f applied to the NodeProxys in nodes
*
* @throws XPathException if an error occurs with the query.
*/
public static NodeSet transformNodes(final NodeSet nodes, final Function transform) throws XPathException {
final NodeSet result = new ExtArrayNodeSet();
for (NodeProxy nodeProxy : nodes) {
final NodeProxy node = transform.apply(nodeProxy);
if (node != null) {
result.add(node);
}
}
result.iterate(); // ensure result is ready to use
return result;
}
public static NodeSet getNodesMatchingAtStart(final NodeSet nodes, final int expressionId) throws XPathException {
return transformNodes(nodes, proxy ->
NodeProxies.transformOwnMatches(
proxy,
match -> match.filterOffsetsStartingAt(0),
expressionId
)
);
}
public static NodeSet getNodesMatchingAtEnd(final NodeSet nodes, final int expressionId) throws XPathException {
return transformNodes(nodes, proxy ->
NodeProxies.transformOwnMatches(
proxy,
match -> match.filterOffsetsEndingAt(proxy.getNodeValue().length()),
expressionId
)
);
}
}