/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.ode.utils.stl;
/**
* Interface used for defining object filters/selectors, classes that are used
* to determine whether a given object belong in a set.
*
* <p>
* Created on Feb 4, 2004 at 4:48:55 PM.
* </p>
*
* @author Maciej Szefler <a href="mailto:mbs@fivesight.com">mbs</a>
*/
public abstract class MemberOfFunction<E> implements UnaryFunction<E, Boolean> {
/**
* A unary function that tests whether an element is the member of a set.
*
* @param o
* element to test
* @return <code>true</code> if element is a member
*/
public abstract boolean isMember(E o);
/**
* Implementation of {@link UnaryFunction} method defering to
* {@link #isMember(E)}.
*
* @param x
* element to test
* @return {@link Boolean.TRUE} if isMemeber returns <code>true</code>,
* <code>false</code> otherwise
*/
public final Boolean apply(E x) {
return isMember(x) ? Boolean.TRUE : Boolean.FALSE;
}
public static class InstanceOf extends MemberOfFunction {
private Class _cls;
public InstanceOf(Class cls) { _cls = cls; }
@Override
public boolean isMember(Object o) {
return _cls.isInstance(o);
}
}
}