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.rel.rules;
  
  import org.apache.calcite.plan.RelOptRuleCall;
  import org.apache.calcite.plan.RelRule;
  import org.apache.calcite.rel.RelNode;
  import org.apache.calcite.rel.logical.LogicalCalc;
  import org.apache.calcite.rel.logical.LogicalFilter;
  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.rex.RexUtil;
  import org.apache.calcite.tools.RelBuilderFactory;
  
  import org.immutables.value.Value;
  
  /**
   * Planner rule that converts a
   * {@link org.apache.calcite.rel.logical.LogicalFilter} to a
   * {@link org.apache.calcite.rel.logical.LogicalCalc}.
   *
   * <p>The rule does <em>NOT</em> fire if the child is a
   * {@link org.apache.calcite.rel.logical.LogicalFilter} or a
   * {@link org.apache.calcite.rel.logical.LogicalProject} (we assume that they
   * will be converted using {@link FilterToCalcRule} or
   * {@link ProjectToCalcRule}) or a
   * {@link org.apache.calcite.rel.logical.LogicalCalc}. This
   * {@link org.apache.calcite.rel.logical.LogicalFilter} will eventually be
   * converted by {@link FilterCalcMergeRule}.
   *
   * @see CoreRules#FILTER_TO_CALC
   */
  @Value.Enclosing
  public class FilterToCalcRule
      extends RelRule<FilterToCalcRule.Config>
      implements TransformationRule {
  
    /** Creates a FilterToCalcRule. */
    protected FilterToCalcRule(Config config) {
      super(config);
    }
  
    @Deprecated // to be removed before 2.0
    public FilterToCalcRule(RelBuilderFactory relBuilderFactory) {
      this(Config.DEFAULT.withRelBuilderFactory(relBuilderFactory)
          .as(Config.class));
    }
  
    //~ Methods ----------------------------------------------------------------
  
    @Override public void onMatch(RelOptRuleCall call) {
      final LogicalFilter filter = call.rel(0);
      final RelNode rel = filter.getInput();
  
      // Create a program containing a filter.
      final RexBuilder rexBuilder = filter.getCluster().getRexBuilder();
      final RelDataType inputRowType = rel.getRowType();
      final RexProgramBuilder programBuilder =
          new RexProgramBuilder(inputRowType, rexBuilder);
      programBuilder.addIdentity();
      programBuilder.addCondition(filter.getCondition());
      final RexProgram program = programBuilder.getProgram();
  
      final LogicalCalc calc = LogicalCalc.create(rel, program);
      call.transformTo(calc);
    }
  
    /** Rule configuration. */
    @Value.Immutable
    public interface Config extends RelRule.Config {
      Config DEFAULT = ImmutableFilterToCalcRule.Config.of()
          .withOperandSupplier(b ->
              b.operand(LogicalFilter.class)
                  .predicate(filter ->
                      !RexUtil.SubQueryFinder.containsSubQuery(filter))
                  .anyInputs());
  
      @Override default FilterToCalcRule toRule() {
        return new FilterToCalcRule(this);
      }
    }
  }
  