jpa/org.eclipse.persistence.jpa.jpql/src/main/java/org/eclipse/persistence/jpa/jpql/parser/InternalConcatExpressionBNF.java

/*
 * Copyright (c) 2006, 2021 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;

/**
 * The query BNF for the <b>COUNT</b> expression's encapsulated expressions.
 * <p></p>
 * JPA 1.0:
 * <div><b>BNF:</b> <code>expression ::= CONCAT(string_primary, string_primary)</code></div>
 * <p></p>
 * JPA 2.0:
 * <div><b>BNF:</b> <code>expression ::= CONCAT(string_primary, string_primary {, string_primary}*)</code></div>
 * <p></p>
 * JPA 2.1:
 * <div><b>BNF:</b> <code>expression ::= CONCAT(string_expression, string_expression {, string_expression}*)</code></div>
 * <p></p>
 *
 * @version 2.5
 * @since 2.3
 * @author Pascal Filion
 */
@SuppressWarnings("nls")
public final class InternalConcatExpressionBNF extends JPQLQueryBNF {

    /**
     * The unique identifier of this <code>InternalConcatExpressionBNF</code>.
     */
    public final static String ID = "internal_concat";

    /**
     * Creates a new <code>InternalConcatExpressionBNF</code>.
     */
    public InternalConcatExpressionBNF() {
        super(ID);
    }

    @Override
    protected void initialize() {
        super.initialize();
        setHandleAggregate(true); // To support invalid queries
        setHandleCollection(true);
        setFallbackBNFId(LiteralExpressionFactory.ID);
        registerChild(StringPrimaryBNF.ID);
    }
}