/*
* eXist Open Source Native XML Database
* Copyright (C) 2004-2009 The eXist Project
* http://exist-db.org
*
* 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.fn;
import org.exist.dom.ExtArrayNodeSet;
import org.exist.dom.NodeSet;
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:remove function.
*
* @author <a href="mailto:piotr@ideanest.com">Piotr Kaminski</a>
*/
public class FunRemove extends Function {
public final static FunctionSignature signature =
new FunctionSignature(
new QName("remove", Function.BUILTIN_FUNCTION_NS),
"Returns a new sequence constructed from the value of $target with the item " +
"at $position removed.\n\nIf $position " +
"is less than 1 or greater than the number of items in $target, $target is returned. " +
"Otherwise, the value returned by the function consists of all items of $target " +
"whose index is less than $position, followed by all items of $target whose index " +
"is greater than $position. If $target is the empty sequence, the empty sequence " +
"is returned.",
new SequenceType[] {
new FunctionParameterSequenceType("target", Type.ITEM, Cardinality.ZERO_OR_MORE, "The input sequence"),
new FunctionParameterSequenceType("position", Type.INTEGER, Cardinality.ONE, "The position of the value to be removed")
},
new FunctionReturnSequenceType(Type.ITEM, Cardinality.ZERO_OR_MORE, "the new sequence with the item at the position specified by the value of $position removed."));
public FunRemove(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 seq = getArgument(0).eval(contextSequence, contextItem);
if (seq.isEmpty())
{result = Sequence.EMPTY_SEQUENCE;}
else {
//TODO : explain this Double conversion -pb
int pos = ((DoubleValue)getArgument(1).eval(contextSequence, contextItem).convertTo(Type.DOUBLE)).getInt();
if (pos < 1 || pos > seq.getItemCount())
{result= seq;}
else {
pos--;
if (seq instanceof NodeSet) {
result = new ExtArrayNodeSet();
result.addAll((NodeSet) seq);
result = ((NodeSet)result).except((NodeSet) seq.itemAt(pos));
} else {
result = new ValueSequence();
for (int i = 0; i < seq.getItemCount(); i++) {
if (i != pos) {result.add(seq.itemAt(i));}
}
}
}
}
if (context.getProfiler().isEnabled())
{context.getProfiler().end(this, "", result);}
return result;
}
@Override
public int getDependencies() {
return Dependency.NO_DEPENDENCY;
}
}