/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-2009 the eXist team
*
* This program 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
* of the License, or (at your option) any later version.
*
* This program 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 program; if not, write to the Free Software Foundation
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $Id$
*/
package org.exist.xquery.functions;
import org.exist.dom.QName;
import org.exist.xquery.Cardinality;
import org.exist.xquery.Dependency;
import org.exist.xquery.Function;
import org.exist.xquery.FunctionSignature;
import org.exist.xquery.Profiler;
import org.exist.xquery.XPathException;
import org.exist.xquery.XQueryContext;
import org.exist.xquery.value.DoubleValue;
import org.exist.xquery.value.FunctionParameterSequenceType;
import org.exist.xquery.value.FunctionReturnSequenceType;
import org.exist.xquery.value.Item;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.Type;
import org.exist.xquery.value.ValueSequence;
/**
* Implements the fn:insert-before function.
*
* @author <a href="mailto:piotr@ideanest.com">Piotr Kaminski</a>
*/
public class FunInsertBefore extends Function {
protected static final String FUNCTION_DESCRIPTION =
"Returns a new sequence constructed from the value " +
"of $target with the value of $inserts inserted at " +
"the position specified by the value of $position. " +
"(The value of $target is not affected by the sequence construction.)\n\n" +
"If $target is the empty sequence, $inserts is returned. If $inserts is the empty sequence, $target is returned.\n\n" +
"The value returned by the function consists of all items " +
"of $target whose index is less than $position, followed " +
"by all items of $inserts, followed by the remaining elements " +
"of $target, in that sequence.\n\n" +
"If $position is less than one (1), the first position, the effective " +
"value of $position is one (1). If $position is greater than the number " +
"of items in $target, then the effective value of $position is " +
"equal to the number of items in $target plus 1.";
public final static FunctionSignature signature =
new FunctionSignature(
new QName("insert-before", Function.BUILTIN_FUNCTION_NS),
FUNCTION_DESCRIPTION,
new SequenceType[] {
new FunctionParameterSequenceType("target", Type.ITEM, Cardinality.ZERO_OR_MORE, "The target"),
new FunctionParameterSequenceType("position", Type.INTEGER, Cardinality.ONE, "The position to insert before"),
new FunctionParameterSequenceType("inserts", Type.ITEM, Cardinality.ZERO_OR_MORE, "The data to insert")
},
new FunctionReturnSequenceType(Type.ITEM, Cardinality.ZERO_OR_MORE, "the new sequence"));
public FunInsertBefore(XQueryContext context) {
super(context, signature);
}
public Sequence eval(Sequence contextSequence, Item contextItem) throws XPathException {
if (context.getProfiler().isEnabled()) {
context.getProfiler().start(this);
context.getProfiler().message(this, Profiler.DEPENDENCIES, "DEPENDENCIES", Dependency.getDependenciesName(this.getDependencies()));
if (contextSequence != null)
context.getProfiler().message(this, Profiler.START_SEQUENCES, "CONTEXT SEQUENCE", contextSequence);
if (contextItem != null)
context.getProfiler().message(this, Profiler.START_SEQUENCES, "CONTEXT ITEM", contextItem.toSequence());
}
Sequence result;
Sequence seq1 = getArgument(0).eval(contextSequence, contextItem);
Sequence seq2 = getArgument(2).eval(contextSequence, contextItem);
if (seq1.isEmpty())
result = seq2;
else if (seq2.isEmpty())
result = seq1;
else {
int pos =
((DoubleValue)getArgument(1).eval(contextSequence, contextItem).convertTo(Type.DOUBLE)).getInt();
pos--;
result = new ValueSequence();
if (pos <= 0) {
result.addAll(seq2);
result.addAll(seq1);
} else if (pos >= seq1.getItemCount()) {
result.addAll(seq1);
result.addAll(seq2);
} else {
for (int i=0; i<seq1.getItemCount(); i++) {
if (i == pos) result.addAll(seq2);
result.add(seq1.itemAt(i));
}
}
}
if (context.getProfiler().isEnabled())
context.getProfiler().end(this, "", result);
return result;
}
}