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.calcite.linq4j.tree;
  
  import java.lang.reflect.Type;
  
  /**
   * Analogous to LINQ's System.Linq.Expression.
   */
  public abstract class Expression extends AbstractNode {
  
    /**
     * Creates an Expression.
     *
     * <p>The type of the expression may, at the caller's discretion, be a
     * regular class (because {@link Class} implements {@link Type}) or it may
     * be a different implementation that retains information about type
     * parameters.
     *
     * @param nodeType Node type
     * @param type Type of the expression
     */
    protected Expression(ExpressionType nodeType, Type type) {
      super(nodeType, type);
    }
  
    @Override // More specific return type.
    public abstract Expression accept(Shuttle shuttle);
  
    /**
     * Indicates that the node can be reduced to a simpler node. If this
     * returns true, Reduce() can be called to produce the reduced form.
     */
    public boolean canReduce() {
      return false;
    }
  }
  