/*
* 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.fn;
import org.exist.dom.QName;
import org.exist.xquery.Cardinality;
import org.exist.xquery.Dependency;
import org.exist.xquery.ErrorCodes;
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;
/**
* xpath-library function: number(object) $context/number()
*
*/
public class FunNumber extends Function {
protected static final String FUNCTION_DESCRIPTION_0_PARAM =
"Returns the value of the context item after atomization, " +
"converted to an xs:double.\n\n" +
"If the context item cannot be " +
"converted to an xs:double, the xs:double value NaN is returned. " +
"If the context item is undefined an error is raised: " +
"[err:XPDY0002]XP.\n\n";
protected static final String FUNCTION_DESCRIPTION_1_PARAM =
"Returns the value indicated by $arg or, if $arg is not specified, " +
"the context item after atomization, converted to an xs:double.\n\n" +
"Calling the zero-argument version of the function is defined to " +
"give the same result as calling the single-argument version with " +
"the context item (.). That is, fn:number() is equivalent to fn:number(.).\n\n" +
"If $arg is the empty sequence or if $arg or the context item cannot be " +
"converted to an xs:double, the xs:double value NaN is returned. " +
"If the " +
"context item is undefined an error is raised: [err:XPDY0002]XP.\n\n" +
"If $arg is the empty sequence, NaN is returned. Otherwise, $arg, or " +
"the context item after atomization, is converted to an xs:double " +
"following the rules of 17.1.3.2 Casting to xs:double. If the conversion " +
"to xs:double fails, the xs:double value NaN is returned.";
protected static final FunctionParameterSequenceType ARG_PARAM = new FunctionParameterSequenceType("arg", Type.ATOMIC, Cardinality.ZERO_OR_ONE, "The input item");
protected static final FunctionReturnSequenceType RETURN_TYPE = new FunctionReturnSequenceType(Type.DOUBLE, Cardinality.EXACTLY_ONE, "the numerical value");
public final static FunctionSignature signatures[] = {
new FunctionSignature(
new QName("number", Function.BUILTIN_FUNCTION_NS),
FUNCTION_DESCRIPTION_0_PARAM,
new SequenceType[0],
RETURN_TYPE
),
new FunctionSignature(
new QName("number", Function.BUILTIN_FUNCTION_NS),
FUNCTION_DESCRIPTION_1_PARAM,
new SequenceType[] { ARG_PARAM },
RETURN_TYPE
)
};
public FunNumber(XQueryContext context, FunctionSignature signature) {
super(context, signature);
}
@Override
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 arg = null;
if(getSignature().getArgumentCount() == 1) {
//value is from $arg
arg = getArgument(0).eval(contextSequence);
if(arg.isEmpty()) {
result = DoubleValue.NaN;
} else {
try {
result = arg.convertTo(Type.DOUBLE);
} catch(final XPathException e) {
result = DoubleValue.NaN;
}
}
} else {
//value is from $context
if(contextSequence == null) {
throw new XPathException(this, ErrorCodes.XPDY0002, "Undefined context item");
}
arg = contextSequence;
if(arg.isEmpty()) {
result = Sequence.EMPTY_SEQUENCE;
} else {
try {
result = arg.convertTo(Type.DOUBLE);
} catch(final XPathException e) {
result = DoubleValue.NaN;
}
}
}
if(context.getProfiler().isEnabled()) {
context.getProfiler().end(this, "", result);
}
return result;
}
}