/*
* @(#)$Id: MergeAdjacentTextSequence.java 3619 2008-03-26 07:23:03Z yui $
*
* Copyright 2006-2008 Makoto YUI
*
* Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Contributors:
* Makoto YUI - initial implementation
*/
package xbird.xquery.dm.value.sequence;
import java.util.Iterator;
import xbird.xquery.XQueryException;
import xbird.xquery.dm.NodeKind;
import xbird.xquery.dm.value.*;
import xbird.xquery.dm.value.literal.XString;
import xbird.xquery.dm.value.node.DMText;
import xbird.xquery.meta.DynamicContext;
import xbird.xquery.meta.IFocus;
/**
* Adjacent text nodes in the content sequence are merged into a single text node
by concatenating their contents, with no intervening blanks.
* <DIV lang="en"></DIV>
* <DIV lang="ja"></DIV>
*
* @author Makoto YUI (yuin405+xbird@gmail.com)
*/
public final class MergeAdjacentTextSequence extends ProxySequence<Item> {
private static final long serialVersionUID = -8309716270458744214L;
public MergeAdjacentTextSequence(Sequence delegate, DynamicContext dynEnv) {
super(delegate, dynEnv);
}
public boolean next(IFocus focus) throws XQueryException {
Item pending = focus.pollItem();
if(pending != null) {
focus.setContextItem(pending);
return true;
}
Iterator<? extends Item> delItor = focus.getBaseFocus();
if(!delItor.hasNext()) {
return false;
}
final StringBuilder buf = new StringBuilder(256);
do {
Item it = delItor.next();
if(it instanceof XQNode) {
XQNode n = (XQNode) it;
if(n.nodeKind() == NodeKind.TEXT) {
final String sv = n.stringValue();
assert (sv != null);
if(sv.length() > 0) {
buf.append(sv);
}
continue;
}
} else if(it instanceof XString) {
buf.append(it.stringValue());
continue;
}
focus.offerItem(it);
break;
} while(delItor.hasNext());
if(buf.length() > 0) {
final String c = buf.toString();
focus.setContextItem(new DMText(c));
} else {
pending = focus.pollItem();
if(pending == null) {
return false; // may comes here.
}
focus.setContextItem(pending);
assert (focus.pollItem() == null) : "should not have more than one polling item!";
}
return true;
}
}