jpa/org.eclipse.persistence.jpa.jpql/src/main/java/org/eclipse/persistence/jpa/jpql/parser/SizeExpression.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;

import org.eclipse.persistence.jpa.jpql.WordParser;

/**
 * The <b>SIZE</b> function returns an integer value, the number of elements of the collection. If
 * the collection is empty, the <b>SIZE</b> function evaluates to zero.
 *
 * <div><b>BNF:</b> <code>expression ::= SIZE(collection_valued_path_expression)</code><p></p></div>
 *
 * @version 2.5
 * @since 2.3
 * @author Pascal Filion
 */
public final class SizeExpression extends AbstractSingleEncapsulatedExpression {

    /**
     * Creates a new <code>SizeExpression</code>.
     *
     * @param parent The parent of this expression
     */
    public SizeExpression(AbstractExpression parent) {
        super(parent, SIZE);
    }

    @Override
    public void accept(ExpressionVisitor visitor) {
        visitor.visit(this);
    }

    @Override
    public String getEncapsulatedExpressionQueryBNFId() {
        return CollectionValuedPathExpressionBNF.ID;
    }

    @Override
    public JPQLQueryBNF getQueryBNF() {
        return getQueryBNF(FunctionsReturningNumericsBNF.ID);
    }

    @Override
    protected AbstractExpression parse(WordParser wordParser, String queryBNFId, boolean tolerant) {

        if (tolerant) {
            return super.parse(wordParser, queryBNFId, tolerant);
        }

        CollectionValuedPathExpression expression = new CollectionValuedPathExpression(this, wordParser.word());
        expression.parse(wordParser, tolerant);
        return expression;
    }
}