org.eclipse.persistence.jpa.jpql.parser.StringExpression Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of eclipselink Show documentation

EclipseLink build based upon Git transaction f2b9fc5

There is a newer version: 5.0.0-B03

/*
 * Copyright (c) 2023 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
//     06/02/2023: Radek Felcman
//       - Issue 1885: Implement new JPQLGrammar for upcoming Jakarta Persistence 3.2
package org.eclipse.persistence.jpa.jpql.parser;

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

/**
 * This expression represents a String expression, which means the first and second expressions
 * are aggregated with a String sign.
 *
 * @see ConcatPipesExpression
 *
 * @version 2.5
 * @since 2.3
 * @author Pascal Filion
 */
public abstract class StringExpression extends CompoundExpression {

    /**
     * Creates a new StringExpression.
     *
     * @param parent The parent of this expression
     */
    protected StringExpression(AbstractExpression parent, String identifier) {
        super(parent, identifier);
    }

    @Override
    public JPQLQueryBNF findQueryBNF(Expression expression) {
        return getParent().findQueryBNF(expression);
    }

    /**
     * Returns the string sign this expression is actually representing.
     *
     * @return The single character value of the string sign
     */
    public final String getStringSign() {
        return getText();
    }

    @Override
    public String getLeftExpressionQueryBNFId() {
        return StringExpressionBNF.ID;
    }

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

    @Override
    public final String getRightExpressionQueryBNFId() {
        return StringTermBNF.ID;
    }

    @Override
    protected boolean isParsingComplete(WordParser wordParser, String word, Expression expression) {

        String character = word.substring(0,1);

        // Concat will create a chain of operations
        if ("||".equals(character)) {
            return false;
        }

        return (expression != null);
    }

    @Override
    protected final String parseIdentifier(WordParser wordParser) {
        return getText();
    }
}