/*
* Copyright Aduna (http://www.aduna-software.com/) (c) 2007.
*
* Licensed under the Aduna BSD-style license.
*/
package org.openrdf.query.algebra.evaluation.function;
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:float</tt>.
*
* @author Arjohn Kampman
*/
public class FloatCast implements Function {
public String getURI() {
return XMLSchema.FLOAT.toString();
}
public Literal evaluate(ValueFactory valueFactory, Value... args)
throws ValueExprEvaluationException
{
if (args.length != 1) {
throw new ValueExprEvaluationException("xsd:float 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 floatValue = XMLDatatypeUtil.collapseWhiteSpace(literal.getLabel());
if (XMLDatatypeUtil.isValidFloat(floatValue)) {
return valueFactory.createLiteral(floatValue, XMLSchema.FLOAT);
}
}
else if (datatype != null) {
if (datatype.equals(XMLSchema.FLOAT)) {
return literal;
}
else if (XMLDatatypeUtil.isNumericDatatype(datatype)) {
// FIXME: doubles must be processed separately, see
// http://www.w3.org/TR/xpath-functions/#casting-from-primitive-to-primitive
try {
float floatValue = literal.floatValue();
return valueFactory.createLiteral(floatValue);
}
catch (NumberFormatException e) {
throw new ValueExprEvaluationException(e.getMessage(), e);
}
}
else if (datatype.equals(XMLSchema.BOOLEAN)) {
try {
return valueFactory.createLiteral(literal.booleanValue() ? 1f : 0f);
}
catch (IllegalArgumentException e) {
throw new ValueExprEvaluationException(e.getMessage(), e);
}
}
}
}
throw new ValueExprEvaluationException("Invalid argument for xsd:float cast: " + args[0]);
}
}