jpa/org.eclipse.persistence.jpa.jpql/src/main/java/org/eclipse/persistence/jpa/jpql/tools/model/query/LocateExpressionStateObject.java

/*
 * Copyright (c) 2011, 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.tools.model.query;

import org.eclipse.persistence.jpa.jpql.parser.LocateExpression;
import org.eclipse.persistence.jpa.jpql.parser.SimpleArithmeticExpressionBNF;
import org.eclipse.persistence.jpa.jpql.parser.StringPrimaryBNF;
import static org.eclipse.persistence.jpa.jpql.parser.Expression.*;

/**
 * The <code><b>LOCATE</b></code> function returns the position of a given string within a string,
 * starting the search at a specified position. It returns the first position at which the string
 * was found as an integer. The first argument is the string to be located; the second argument is
 * the string to be searched; the optional third argument is an integer that represents the string
 * position at which the search is started (by default, the beginning of the string to be searched).
 * The first position in a string is denoted by 1. If the string is not found, 0 is returned. The
 * <code><b>LENGTH</b></code> function returns the length of the string in characters as an integer.
 *
 * <div><p><b>BNF:</b> <code>expression ::= LOCATE(string_primary, string_primary [, simple_arithmetic_expression])</code></p></div>
 *
 * @see LocateExpression
 *
 * @version 2.4
 * @since 2.4
 * @author Pascal Filion
 */
public class LocateExpressionStateObject extends AbstractTripleEncapsulatedExpressionStateObject {

    /**
     * Creates a new <code>LocateExpressionStateObject</code>.
     *
     * @param parent The parent of this state object, which cannot be <code>null</code>
     * @exception NullPointerException The given parent cannot be <code>null</code>
     */
    public LocateExpressionStateObject(StateObject parent) {
        super(parent);
    }

    /**
     * Creates a new <code>LocateExpressionStateObject</code>.
     *
     * @param parent The parent of this state object, which cannot be <code>null</code>
     * @param firstStateObject The {@link StateObject} of the first expression
     * @param secondStateObject The {@link StateObject} of the second expression
     * @exception NullPointerException The given parent cannot be <code>null</code>
     */
    public LocateExpressionStateObject(StateObject parent,
                                       StateObject firstStateObject,
                                       StateObject secondStateObject) {

        super(parent, firstStateObject, secondStateObject, null);
    }

    /**
     * Creates a new <code>LocateExpressionStateObject</code>.
     *
     * @param parent The parent of this state object, which cannot be <code>null</code>
     * @param firstStateObject The {@link StateObject} of the first expression
     * @param secondStateObject The {@link StateObject} of the second expression
     * @param thirdStateObject The {@link StateObject} of the third encapsulated expression
     * @exception NullPointerException The given parent cannot be <code>null</code>
     */
    public LocateExpressionStateObject(StateObject parent,
                                       StateObject firstStateObject,
                                       StateObject secondStateObject,
                                       StateObject thirdStateObject) {

        super(parent, firstStateObject, secondStateObject, thirdStateObject);
    }

    /**
     * Creates a new <code>LocateExpressionStateObject</code>.
     *
     * @param parent The parent of this state object, which cannot be <code>null</code>
     * @param firstJpqlFragment The string representation of the first encapsulated expression to
     * parse and to convert into a {@link StateObject} representation
     * @param secondJpqlFragment The string representation of the second encapsulated expression to
     * parse and to convert into a {@link StateObject} representation
     * @exception NullPointerException The given parent cannot be <code>null</code>
     */
    public LocateExpressionStateObject(StateObject parent,
                                       String firstJpqlFragment,
                                       String secondJpqlFragment) {

        super(parent, firstJpqlFragment, secondJpqlFragment, null);
    }

    /**
     * Creates a new <code>LocateExpressionStateObject</code>.
     *
     * @param parent The parent of this state object, which cannot be <code>null</code>
     * @param firstJpqlFragment The string representation of the first encapsulated expression to
     * parse and to convert into a {@link StateObject} representation
     * @param secondJpqlFragment The string representation of the second encapsulated expression to
     * parse and to convert into a {@link StateObject} representation
     * @param thirdJpqlFragment The string representation of the third encapsulated expression to
     * parse and to convert into a {@link StateObject} representation
     * @exception NullPointerException The given parent cannot be <code>null</code>
     */
    public LocateExpressionStateObject(StateObject parent,
                                       String firstJpqlFragment,
                                       String secondJpqlFragment,
                                       String thirdJpqlFragment) {

        super(parent, firstJpqlFragment, secondJpqlFragment, thirdJpqlFragment);
    }

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

    @Override
    public LocateExpression getExpression() {
        return (LocateExpression) super.getExpression();
    }

    @Override
    protected String getFirstQueryBNFId() {
        return StringPrimaryBNF.ID;
    }

    @Override
    public String getIdentifier() {
        return LOCATE;
    }

    @Override
    protected String getSecondQueryBNFId() {
        return StringPrimaryBNF.ID;
    }

    @Override
    protected String getThirdQueryBNFId() {
        return SimpleArithmeticExpressionBNF.ID;
    }

    /**
     * Keeps a reference of the {@link LocateExpression parsed object} object, which should only be
     * done when this object is instantiated during the conversion of a parsed JPQL query into
     * {@link StateObject StateObjects}.
     *
     * @param expression The {@link LocateExpression parsed object} representing a <code><b>LOCATE</b></code>
     * expression
     */
    public void setExpression(LocateExpression expression) {
        super.setExpression(expression);
    }
}