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.mutable;
  
  import org.apache.calcite.rel.type.RelDataType;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import java.util.Objects;
  
  /** Mutable equivalent of {@link org.apache.calcite.rel.core.Collect}. */
  public class MutableCollect extends MutableSingleRel {
    public final String fieldName;
  
    private MutableCollect(RelDataType rowType,
        MutableRel input, String fieldName) {
      super(MutableRelType.COLLECT, rowType, input);
      this.fieldName = fieldName;
    }
  
    /**
     * Creates a MutableCollect.
     *
     * @param rowType   Row type
     * @param input     Input relational expression
     * @param fieldName Name of the sole output field
     */
    public static MutableCollect of(RelDataType rowType,
        MutableRel input, String fieldName) {
      return new MutableCollect(rowType, input, fieldName);
    }
  
    @Override public boolean equals(@Nullable Object obj) {
      return obj == this
          || obj instanceof MutableCollect
          && fieldName.equals(((MutableCollect) obj).fieldName)
          && input.equals(((MutableCollect) obj).input);
    }
  
    @Override public int hashCode() {
      return Objects.hash(input, fieldName);
    }
  
    @Override public StringBuilder digest(StringBuilder buf) {
      return buf.append("Collect(fieldName: ").append(fieldName).append(")");
    }
  
    @Override public MutableRel clone() {
      return MutableCollect.of(rowType, input.clone(), fieldName);
    }
  }
  