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.elasticsearch;
  
  import org.apache.calcite.adapter.enumerable.EnumerableConvention;
  import org.apache.calcite.plan.RelTraitSet;
  import org.apache.calcite.rel.RelNode;
  import org.apache.calcite.rel.convert.ConverterRule;
  
  /**
   * Rule to convert a relational expression from
   * {@link ElasticsearchRel#CONVENTION} to {@link EnumerableConvention}.
   */
  public class ElasticsearchToEnumerableConverterRule extends ConverterRule {
    /** Singleton instance of ElasticsearchToEnumerableConverterRule. */
    static final ConverterRule INSTANCE = Config.INSTANCE
        .withConversion(RelNode.class, ElasticsearchRel.CONVENTION,
            EnumerableConvention.INSTANCE,
            "ElasticsearchToEnumerableConverterRule")
        .withRuleFactory(ElasticsearchToEnumerableConverterRule::new)
        .toRule(ElasticsearchToEnumerableConverterRule.class);
  
    /** Called from the Config. */
    protected ElasticsearchToEnumerableConverterRule(Config config) {
      super(config);
    }
  
    @Override public RelNode convert(RelNode relNode) {
      RelTraitSet newTraitSet = relNode.getTraitSet().replace(getOutConvention());
      return new ElasticsearchToEnumerableConverter(relNode.getCluster(), newTraitSet, relNode);
    }
  }
  