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.lang.common.base;
  
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.hyracks.algebricks.core.algebra.expressions.IExpressionAnnotation;
  
  /**
   * All subclasses need to make sure the hints are copied over in the DeepCopyVisitor and
   * CloneAndSubstituteVariablesVisitor
   */
  public abstract class AbstractExpression extends AbstractLangExpression implements Expression {
  
      protected List<IExpressionAnnotation> hints;
  
      public void addHint(IExpressionAnnotation hint) {
          if (hint == null) {
              return;
          }
          if (hints == null) {
              hints = new ArrayList<>();
          }
          hints.add(hint);
      }
  
      public void addHints(List<IExpressionAnnotation> newHints) {
          if (newHints == null) {
              return;
          }
          if (hints == null) {
              hints = new ArrayList<>();
          }
          hints.addAll(newHints);
      }
  
      public boolean hasHints() {
          return hints != null;
      }
  
      public List<IExpressionAnnotation> getHints() {
          return hints;
      }
  
      public <T extends IExpressionAnnotation> T findHint(Class<T> hintClass) {
          if (hints != null) {
              for (IExpressionAnnotation hint : hints) {
                  if (hint.getClass().equals(hintClass)) {
                      return hintClass.cast(hint);
                  }
              }
          }
          return null;
      }
  }
  