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.asterix.metadata.dataset.hints;
  
  import org.apache.asterix.common.dataflow.ICcApplicationContext;
  import org.apache.hyracks.algebricks.common.utils.Pair;
  
  /**
   * Represents a hint provided as part of an AQL statement.
   */
  public interface IHint {
  
      /**
       * retrieve the name of the hint.
       *
       * @return
       */
      public String getName();
  
      /**
       * validate the value associated with the hint.
       *
       * @param value
       *            the value associated with the hint.
       * @return a Pair with
       *         first element as a boolean that represents the validation result.
       *         second element as the error message if the validation result is false
       */
      public Pair<Boolean, String> validateValue(ICcApplicationContext appCtx, String value);
  
  }
  