/*******************************************************************************
* Copyright (c) 2006, 2011 Oracle. All rights reserved.
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Oracle - initial API and implementation
*
******************************************************************************/
package org.eclipse.persistence.jpa.internal.jpql;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import org.eclipse.persistence.jpa.jpql.TypeHelper;
import org.eclipse.persistence.jpa.jpql.spi.IType;
import org.eclipse.persistence.jpa.jpql.spi.ITypeDeclaration;
/**
* This {@link Resolver} is responsible to return the numeric type for a list of {@link Resolver
* Resolvers}.
* <p>
* The result of a <b>CASE</b> expression, <b>COALESCE</b> expression, <b>NULLIF</b> expression, or
* arithmetic expression (+, -, *, /) is determined by applying the following rule to its operands.
* <p>
* <ul>
* <li>If there is an operand of type <code>Double</code> or <code>double</code>, the result of the
* operation is of type <code>Double</code>;
* <li>otherwise, if there is an operand of type <code>Float</code> or <code>float</code>, the
* result of the operation is of type <code>Float</code>;
* <li>otherwise, if there is an operand of type <code>BigDecimal</code>, the result of the
* operation is of type <code>BigDecimal</code>;
* <li>otherwise, if there is an operand of type <code>BigInteger</code>, the result of the
* operation is of type <code>BigInteger</code>, unless the operator is / (division), in which
* case the numeric result type is not further defined;
* <li>otherwise, if there is an operand of type <code>Long</code> or <code>long</code>, the result
* of the operation is of type <code>Long</code>, unless the operator is / (division), in which
* case the numeric result type is not further defined;
* <li>otherwise, if there is an operand of integral type, the result of the operation is of type
* <code>Integer</code>, unless the operator is / (division), in which case the numeric result
* type is not further defined.
* </ul>
*
* @version 2.3
* @since 2.3
* @author Pascal Filion
*/
final class NumericResolver extends Resolver {
/**
* The {@link Resolver resolvers} used to calculate the numeric type.
*/
private final Collection<Resolver> resolvers;
/**
* Creates a new <code>NumericResolver</code>.
*
* @param parent The parent {@link Resolver}, which is never <code>null</code>
* @param resolvers The {@link Resolver resolvers} used to calculate the numeric type
*/
NumericResolver(Resolver parent, Collection<Resolver> typeResolvers) {
super(parent);
this.resolvers = typeResolvers;
}
/**
* Creates a new <code>NumericResolver</code>.
*
* @param parent The parent {@link Resolver}, which is never <code>null</code>
* @param resolver The {@link Resolver} used to calculate the numeric type
*/
NumericResolver(Resolver parent, Resolver resolver) {
this(parent, Collections.singleton(resolver));
}
/**
* {@inheritDoc}
*/
@Override
public void accept(ResolverVisitor visitor) {
}
/**
* {@inheritDoc}
*/
@Override
IType buildType() {
List<IType> types = new ArrayList<IType>(resolvers.size());
TypeHelper helper = getTypeHelper();
IType unresolvableType = helper.unknownType();
// Convert any primitive types into its Class type and any non-number into Object
for (Resolver typeResolver : resolvers) {
IType type = typeResolver.getType();
// Only a resolvable type will be added to the list
if (type != unresolvableType) {
// Non-numeric type cannot be added
if (!helper.isNumericType(type)) {
type = helper.objectType();
}
types.add(type);
}
}
if (types.isEmpty()) {
return helper.unknownType();
}
// Comparing the types will result in putting the
// result at the beginning of the list
Collections.sort(types, new NumericTypeComparator(helper));
return types.get(0);
}
/**
* {@inheritDoc}
*/
@Override
ITypeDeclaration buildTypeDeclaration() {
return getType().getTypeDeclaration();
}
}