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/*
* Copyright (c) 2006, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0,
* or the Eclipse Distribution License v. 1.0 which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
*/
// Contributors:
// Oracle - initial API and implementation
//
package org.eclipse.persistence.jpa.jpql.parser;
import org.eclipse.persistence.jpa.jpql.WordParser;
/**
* An entity type expression can be used to restrict query polymorphism. The TYPE operator
* returns the exact type of the argument.
*
* Part of JPA 2.0.
*
*
BNF: type_discriminator ::= TYPE(identification_variable |
* single_valued_object_path_expression |
* input_parameter)
*
* @version 2.5
* @since 2.3
* @author Pascal Filion
*/
public final class TypeExpression extends AbstractSingleEncapsulatedExpression {
/**
* Creates a new TypeExpression
.
*
* @param parent The parent of this expression
*/
public TypeExpression(AbstractExpression parent) {
super(parent, TYPE);
}
/**
* {@inheritDoc}
*/
public void accept(ExpressionVisitor visitor) {
visitor.visit(this);
}
/**
* {@inheritDoc}
*/
@Override
public String getEncapsulatedExpressionQueryBNFId() {
return InternalEntityTypeExpressionBNF.ID;
}
/**
* {@inheritDoc}
*/
public JPQLQueryBNF getQueryBNF() {
return getQueryBNF(TypeExpressionBNF.ID);
}
/**
* {@inheritDoc}
*/
@Override
protected AbstractExpression parse(WordParser wordParser, String queryBNFId, boolean tolerant) {
if (tolerant) {
return super.parse(wordParser, queryBNFId, tolerant);
}
return buildExpressionFromFallingBack(
wordParser,
wordParser.word(),
getQueryBNF(InternalEntityTypeExpressionBNF.ID),
null,
tolerant
);
}
}