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.plan.Convention;
  import org.apache.calcite.rel.RelNode;
  import org.apache.calcite.rel.convert.ConverterRule;
  import org.apache.calcite.rel.core.Correlate;
  import org.apache.calcite.rel.logical.LogicalCorrelate;
  
  import org.immutables.value.Value;
  
  /**
   * Implementation of nested loops over enumerable inputs.
   *
   * @see EnumerableRules#ENUMERABLE_CORRELATE_RULE
   */
  @Value.Enclosing
  public class EnumerableCorrelateRule extends ConverterRule {
    /** Default configuration. */
    public static final Config DEFAULT_CONFIG = Config.INSTANCE
        .withConversion(LogicalCorrelate.class, r -> true, Convention.NONE,
            EnumerableConvention.INSTANCE, "EnumerableCorrelateRule")
        .withRuleFactory(EnumerableCorrelateRule::new);
  
    /** Creates an EnumerableCorrelateRule. */
    protected EnumerableCorrelateRule(Config config) {
      super(config);
    }
  
    @Override public RelNode convert(RelNode rel) {
      final Correlate c = (Correlate) rel;
      return EnumerableCorrelate.create(
          convert(c.getLeft(), c.getLeft().getTraitSet()
              .replace(EnumerableConvention.INSTANCE)),
          convert(c.getRight(), c.getRight().getTraitSet()
              .replace(EnumerableConvention.INSTANCE)),
          c.getCorrelationId(),
          c.getRequiredColumns(),
          c.getJoinType());
    }
  }
  