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.RelOptRuleCall;
  import org.apache.calcite.plan.RelRule;
  import org.apache.calcite.rel.RelNode;
  import org.apache.calcite.rel.type.RelDataType;
  import org.apache.calcite.rex.RexBuilder;
  import org.apache.calcite.rex.RexProgram;
  import org.apache.calcite.rex.RexProgramBuilder;
  import org.apache.calcite.tools.RelBuilderFactory;
  
  import org.immutables.value.Value;
  
  /** Variant of {@link org.apache.calcite.rel.rules.FilterToCalcRule} for
   * {@link org.apache.calcite.adapter.enumerable.EnumerableConvention enumerable calling convention}.
   *
   * @see EnumerableRules#ENUMERABLE_FILTER_TO_CALC_RULE */
  @Value.Enclosing
  public class EnumerableFilterToCalcRule
      extends RelRule<EnumerableFilterToCalcRule.Config> {
    /** Creates an EnumerableFilterToCalcRule. */
    protected EnumerableFilterToCalcRule(Config config) {
      super(config);
    }
  
    @Deprecated // to be removed before 2.0
    public EnumerableFilterToCalcRule(RelBuilderFactory relBuilderFactory) {
      this(Config.DEFAULT.withRelBuilderFactory(relBuilderFactory)
          .as(Config.class));
    }
  
    @Override public void onMatch(RelOptRuleCall call) {
      final EnumerableFilter filter = call.rel(0);
      final RelNode input = filter.getInput();
  
      // Create a program containing a filter.
      final RexBuilder rexBuilder = filter.getCluster().getRexBuilder();
      final RelDataType inputRowType = input.getRowType();
      final RexProgramBuilder programBuilder =
          new RexProgramBuilder(inputRowType, rexBuilder);
      programBuilder.addIdentity();
      programBuilder.addCondition(filter.getCondition());
      final RexProgram program = programBuilder.getProgram();
  
      final EnumerableCalc calc = EnumerableCalc.create(input, program);
      call.transformTo(calc);
    }
  
    /** Rule configuration. */
    @Value.Immutable
    public interface Config extends RelRule.Config {
      Config DEFAULT = ImmutableEnumerableFilterToCalcRule.Config.of()
          .withOperandSupplier(b ->
              b.operand(EnumerableFilter.class).anyInputs());
  
      @Override default EnumerableFilterToCalcRule toRule() {
        return new EnumerableFilterToCalcRule(this);
      }
    }
  }
  