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.Objects;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * Represents a "while" statement.
   */
  public class WhileStatement extends Statement {
    public final Expression condition;
    public final Statement body;
  
    public WhileStatement(Expression condition, Statement body) {
      super(ExpressionType.While, Void.TYPE);
      this.condition = requireNonNull(condition, "condition");
      this.body = requireNonNull(body, "body");
    }
  
    @Override public Statement accept(Shuttle shuttle) {
      shuttle = shuttle.preVisit(this);
      final Expression condition1 = condition.accept(shuttle);
      final Statement body1 = body.accept(shuttle);
      return shuttle.visit(this, condition1, body1);
    }
  
    @Override public <R> R accept(Visitor<R> visitor) {
      return visitor.visit(this);
    }
  
    @Override void accept0(ExpressionWriter writer) {
      writer.append("while (").append(condition).append(") ").append(
          Blocks.toBlock(body));
    }
  
    @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;
      }
  
      WhileStatement that = (WhileStatement) o;
      return body.equals(that.body)
          && condition.equals(that.condition);
    }
  
    @Override public int hashCode() {
      return Objects.hash(nodeType, type, condition, body);
    }
  }
  