/*
 * Copyright (C) 2002-2022 Sebastiano Vigna
 *
 * 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 PACKAGE;

/** An abstract class providing basic methods for functions implementing a type-specific interface.
 *
 * <p>This class handles directly a default return
 * value (including {@linkplain #defaultReturnValue() methods to access
 * it}). Instances of classes inheriting from this class have just to return
 * {@code defRetValue} to denote lack of a key in type-specific methods. The value
 * is serialized.
 *
 * <p>Implementing subclasses have just to provide type-specific {@code get()},
 * type-specific {@code containsKey()}, and {@code size()} methods.
 *
 */

public abstract class ABSTRACT_FUNCTION KEY_VALUE_GENERIC implements FUNCTION KEY_VALUE_GENERIC, java.io.Serializable {

	private static final long serialVersionUID = -4940583368468432370L;

	protected ABSTRACT_FUNCTION() {}

	/**
	 * The default return value for {@code get()}, {@code put()} and
	 * {@code remove()}.
	 */

	protected VALUE_GENERIC_TYPE defRetValue;

	@Override
	public void defaultReturnValue(final VALUE_GENERIC_TYPE rv) {
		defRetValue = rv;
	}

	@Override
	public VALUE_GENERIC_TYPE defaultReturnValue() {
		return defRetValue;
	}
}
