content: /*
   * 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.ambari.server.api.predicate.operators;
  
  /**
   * Operator representation.
   */
  public interface Operator {
  
    /**
     * Operator types.
     */
    enum TYPE {
      LESS,
      LESS_EQUAL,
      GREATER,
      GREATER_EQUAL,
      EQUAL,
      NOT_EQUAL,
      AND,
      OR,
      NOT,
      IN,
      IS_EMPTY,
      FILTER
    }
  
    /**
     * The highest base operator precedence level.
     */
    int MAX_OP_PRECEDENCE = 3;
  
    /**
     * Get the operator type.
     *
     * @return the operator type
     */
    TYPE getType();
  
    /**
     * Obtain the precedence of the operator.
     * This value is calculated based on the operators base precedence and the context of the
     * surrounding expressions.  Higher precedence values have higher precedence.
     *
     * @return  the precedence of this operator in it's current context
     */
    int getPrecedence();
  }
  