com.hazelcast.org.apache.calcite.util.Optionality Maven / Gradle / Ivy
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* 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 com.hazelcast.com.liance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.com.hazelcast.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 com.hazelcast.org.apache.calcite.util;
/**
* Four states that describe whether a particular behavior or
* property is allowed and/or not allowed.
*/
public enum Optionality {
/** A property is mandatory if an instance must possess it;
* it is an error if it does not. */
MANDATORY,
/** A property is optional if an instance may or may not possess it;
* neither state is an error. */
OPTIONAL,
/** A property is ignored if an instance may or may not possess it;
* if it possesses the property, the effect is as if it does not. */
IGNORED,
/** A property is forbidden if an instance must not possess it;
* it is an error if the instance has the property. */
FORBIDDEN
}