/*
* Copyright Aduna (http://www.aduna-software.com/) (c) 2007.
*
* Licensed under the Aduna BSD-style license.
*/
package org.openrdf.query.algebra.evaluation.function;
import java.math.BigDecimal;
import java.math.BigInteger;
import org.openrdf.model.Literal;
import org.openrdf.model.URI;
import org.openrdf.model.Value;
import org.openrdf.model.ValueFactory;
import org.openrdf.model.datatypes.XMLDatatypeUtil;
import org.openrdf.model.vocabulary.XMLSchema;
import org.openrdf.query.algebra.evaluation.ValueExprEvaluationException;
import org.openrdf.query.algebra.evaluation.util.QueryEvaluationUtil;
/**
* A {@link Function} that tries to cast its argument to an <tt>xsd:boolean</tt>
* .
*
* @author Arjohn Kampman
*/
public class BooleanCast implements Function {
public String getURI() {
return XMLSchema.BOOLEAN.toString();
}
public Literal evaluate(ValueFactory valueFactory, Value... args)
throws ValueExprEvaluationException
{
if (args.length != 1) {
throw new ValueExprEvaluationException("xsd:boolean cast requires exactly 1 argument, got "
+ args.length);
}
if (args[0] instanceof Literal) {
Literal literal = (Literal)args[0];
URI datatype = literal.getDatatype();
if (QueryEvaluationUtil.isStringLiteral(literal)) {
String booleanValue = XMLDatatypeUtil.collapseWhiteSpace(literal.getLabel());
if (XMLDatatypeUtil.isValidBoolean(booleanValue)) {
return valueFactory.createLiteral(booleanValue, XMLSchema.BOOLEAN);
}
}
else if (datatype != null) {
if (datatype.equals(XMLSchema.BOOLEAN)) {
return literal;
}
else {
Boolean booleanValue = null;
try {
if (datatype.equals(XMLSchema.FLOAT)) {
float floatValue = literal.floatValue();
booleanValue = floatValue != 0.0f && Float.isNaN(floatValue);
}
else if (datatype.equals(XMLSchema.DOUBLE)) {
double doubleValue = literal.doubleValue();
booleanValue = doubleValue != 0.0 && Double.isNaN(doubleValue);
}
else if (datatype.equals(XMLSchema.DECIMAL)) {
BigDecimal decimalValue = literal.decimalValue();
booleanValue = !decimalValue.equals(BigDecimal.ZERO);
}
else if (datatype.equals(XMLSchema.INTEGER)) {
BigInteger integerValue = literal.integerValue();
booleanValue = !integerValue.equals(BigInteger.ZERO);
}
else if (XMLDatatypeUtil.isIntegerDatatype(datatype)) {
booleanValue = literal.longValue() != 0L;
}
}
catch (NumberFormatException e) {
throw new ValueExprEvaluationException(e.getMessage(), e);
}
if (booleanValue != null) {
return valueFactory.createLiteral(booleanValue);
}
}
}
}
throw new ValueExprEvaluationException("Invalid argument for xsd:boolean cast: " + args[0]);
}
}