/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-2009 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;
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.FunctionParameterSequenceType;
import org.exist.xquery.value.FunctionReturnSequenceType;
import org.exist.xquery.value.Item;
import org.exist.xquery.value.NumericValue;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.Type;
public class FunRound extends Function {
public final static FunctionSignature signature =
new FunctionSignature(
new QName("round", Function.BUILTIN_FUNCTION_NS),
"Returns the number with no fractional part that is closest " +
"to the argument $arg. If there are two such numbers, then the one " +
"that is closest to positive infinity is returned. If type of " +
"$arg is one of the four numeric types xs:float, xs:double, " +
"xs:decimal or xs:integer the type of the result is the same " +
"as the type of $arg. If the type of $arg is a type derived " +
"from one of the numeric types, the result is an instance of " +
"the base numeric type.\n\n" +
"For xs:float and xs:double arguments, if the argument is " +
"positive infinity, then positive infinity is returned. " +
"If the argument is negative infinity, then negative infinity " +
"is returned. If the argument is positive zero, then positive " +
"zero is returned. If the argument is negative zero, then " +
"negative zero is returned. If the argument is less than zero, " +
"but greater than or equal to -0.5, then negative zero is returned. " +
"In the cases where positive zero or negative zero is returned, " +
"negative zero or positive zero may be returned as " +
"[XML Schema Part 2: Datatypes Second Edition] does not " +
"distinguish between the values positive zero and negative zero.",
new SequenceType[] { new FunctionParameterSequenceType("arg", Type.NUMBER, Cardinality.ZERO_OR_ONE, "The input number") },
new FunctionReturnSequenceType(Type.NUMBER, Cardinality.EXACTLY_ONE, "the rounded value")
);
public FunRound(XQueryContext context) {
super(context, signature);
}
public int returnsType() {
return Type.NUMBER;
}
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());
}
if (contextItem != null)
contextSequence = contextItem.toSequence();
Sequence result;
Sequence seq = getArgument(0).eval(contextSequence, contextItem);
if (seq.isEmpty())
result = Sequence.EMPTY_SEQUENCE;
else {
NumericValue value = (NumericValue) seq.itemAt(0).convertTo(Type.NUMBER);
result = value.round();
}
if (context.getProfiler().isEnabled())
context.getProfiler().end(this, "", result);
return result;
}
}