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.lang.reflect.Modifier;
  import java.util.Objects;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * Declaration of a field.
   */
  public class FieldDeclaration extends MemberDeclaration {
    public final int modifier;
    public final ParameterExpression parameter;
    public final @Nullable Expression initializer;
  
    public FieldDeclaration(int modifier, ParameterExpression parameter,
        @Nullable Expression initializer) {
      this.modifier = modifier;
      this.parameter = requireNonNull(parameter, "parameter");
      this.initializer = initializer;
    }
  
    @Override public MemberDeclaration accept(Shuttle shuttle) {
      shuttle = shuttle.preVisit(this);
      // do not visit parameter - visit may not return a ParameterExpression
      final Expression initializer =
          this.initializer == null ? null : this.initializer.accept(shuttle);
      return shuttle.visit(this, initializer);
    }
  
    @Override public <R> R accept(Visitor<R> visitor) {
      return visitor.visit(this);
    }
  
    @Override public void accept(ExpressionWriter writer) {
      String modifiers = Modifier.toString(modifier);
      writer.append(modifiers);
      if (!modifiers.isEmpty()) {
        writer.append(' ');
      }
      writer.append(parameter.type).append(' ').append(parameter.name);
      if (initializer != null) {
        writer.append(" = ").append(initializer);
      }
      writer.append(';');
      writer.newlineAndIndent();
    }
  
    @Override public boolean equals(@Nullable Object o) {
      if (this == o) {
        return true;
      }
      if (o == null || getClass() != o.getClass()) {
        return false;
      }
  
      FieldDeclaration that = (FieldDeclaration) o;
      return modifier == that.modifier
          && Objects.equals(initializer, that.initializer)
          && parameter.equals(that.parameter);
    }
  
    @Override public int hashCode() {
      return Objects.hash(modifier, parameter, initializer);
    }
  }
  