Placeholder.java

/*
 * Copyright 2015 Martin Kouba
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.trimou.engine.resolver;

/**
 *
 * @author Martin Kouba
 */
public enum Placeholder {

    /**
     * This might be useful to distinguish the case when a value resolver should
     * return a value which should be interpreted as a <code>null</code>.
     * Normally, a resolver returns <code>null</code> in case it's not
     * capable of resolving the value.
     */
    NULL,
}