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.interpreter;
  
  import org.apache.calcite.adapter.enumerable.EnumerableRel;
  import org.apache.calcite.plan.Convention;
  import org.apache.calcite.plan.ConventionTraitDef;
  import org.apache.calcite.plan.RelOptPlanner;
  import org.apache.calcite.plan.RelTrait;
  import org.apache.calcite.plan.RelTraitDef;
  import org.apache.calcite.plan.RelTraitSet;
  
  /**
   * Calling convention that returns results as an
   * {@link org.apache.calcite.linq4j.Enumerable} of object arrays.
   *
   * <p>Unlike enumerable convention, no code generation is required.
   */
  public enum InterpretableConvention implements Convention {
    INSTANCE;
  
    @Override public String toString() {
      return getName();
    }
  
    @Override public Class getInterface() {
      return EnumerableRel.class;
    }
  
    @Override public String getName() {
      return "INTERPRETABLE";
    }
  
    @Override public RelTraitDef getTraitDef() {
      return ConventionTraitDef.INSTANCE;
    }
  
    @Override public boolean satisfies(RelTrait trait) {
      return this == trait;
    }
  
    @Override public void register(RelOptPlanner planner) {}
  
    @Override public boolean canConvertConvention(Convention toConvention) {
      return false;
    }
  
    @Override public boolean useAbstractConvertersForConversion(RelTraitSet fromTraits,
        RelTraitSet toTraits) {
      return false;
    }
  }
  