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.adapter.enumerable;
  
  import org.apache.calcite.DataContext;
  import org.apache.calcite.adapter.java.JavaTypeFactory;
  import org.apache.calcite.linq4j.tree.ParameterExpression;
  import org.apache.calcite.plan.RelImplementor;
  import org.apache.calcite.rex.RexBuilder;
  
  /**
   * Abstract base class for implementations of {@link RelImplementor}
   * that generate java code.
   */
  public abstract class JavaRelImplementor implements RelImplementor {
    private final RexBuilder rexBuilder;
  
    protected JavaRelImplementor(RexBuilder rexBuilder) {
      this.rexBuilder = rexBuilder;
      assert rexBuilder.getTypeFactory() instanceof JavaTypeFactory
          : "Type factory of rexBuilder should be a JavaTypeFactory";
    }
  
    public RexBuilder getRexBuilder() {
      return rexBuilder;
    }
  
    public JavaTypeFactory getTypeFactory() {
      return (JavaTypeFactory) rexBuilder.getTypeFactory();
    }
  
    /**
     * Returns the expression used to access
     * {@link org.apache.calcite.DataContext}.
     *
     * @return expression used to access {@link org.apache.calcite.DataContext}.
     */
    public ParameterExpression getRootExpression() {
      return DataContext.ROOT;
    }
  }
  