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.linq4j.tree;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import java.util.List;
  import java.util.Objects;
  
  import static com.google.common.base.Preconditions.checkArgument;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * Represents indexing a property or array.
   */
  public class IndexExpression extends Expression {
    public final Expression array;
    public final List<Expression> indexExpressions;
  
    public IndexExpression(Expression array, List<Expression> indexExpressions) {
      super(ExpressionType.ArrayIndex,
          requireNonNull(Types.getComponentType(array.getType()),
              () -> "component type for " + array));
      this.array = array;
      this.indexExpressions =
          requireNonNull(indexExpressions, "indexExpressions");
      checkArgument(!indexExpressions.isEmpty(),
          "indexExpressions should not be empty");
    }
  
    @Override public Expression accept(Shuttle shuttle) {
      shuttle = shuttle.preVisit(this);
      Expression array = this.array.accept(shuttle);
      List<Expression> indexExpressions =
          Expressions.acceptExpressions(this.indexExpressions, shuttle);
      return shuttle.visit(this, array, indexExpressions);
    }
  
    @Override public <R> R accept(Visitor<R> visitor) {
      return visitor.visit(this);
    }
  
    @Override void accept(ExpressionWriter writer, int lprec, int rprec) {
      array.accept(writer, lprec, nodeType.lprec);
      writer.list("[", ", ", "]", indexExpressions);
    }
  
    @Override public boolean equals(@Nullable Object o) {
      if (this == o) {
        return true;
      }
      if (o == null || getClass() != o.getClass()) {
        return false;
      }
      if (!super.equals(o)) {
        return false;
      }
  
      IndexExpression that = (IndexExpression) o;
  
      if (!array.equals(that.array)) {
        return false;
      }
      if (!indexExpressions.equals(that.indexExpressions)) {
        return false;
      }
  
      return true;
    }
  
    @Override public int hashCode() {
      return Objects.hash(nodeType, type, array, indexExpressions);
    }
  }
  