content: /*
   * plist - An open source library to parse and generate property lists
   * Copyright (C) 2023 Daniel Dreibrodt
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   */
  
  package com.dd.plist;
  
  import java.io.IOException;
  
  /**
   * Internally used representation of the null value for storing it inside dictionaries and sets.
   * @author Daniel Dreibrodt
   */
  public final class NSNull extends NSObject {
  
      private static final NSNull NULL = new NSNull();
  
      private NSNull() {
      }
  
      /**
       * Returns the specified NSObject if it is not null, or a NSNull instance otherwise.
       * @param o The object.
       * @return The non-null object, or a NSNull instance.
       */
      static NSObject wrap(NSObject o) {
          return o == null ? NULL : o;
      }
  
      /**
       * Returns the specified NSObject if it is not a NSNull instance, or null otherwise.
       * @param o The object.
       * @return The non-null object, or null.
       */
      static NSObject unwrap(NSObject o) {
          return o == NULL ? null : o;
      }
  
      @Override
      public NSObject clone() {
          return this;
      }
  
      @Override
      public Object toJavaObject() {
          return null;
      }
  
      @Override
      void toXML(StringBuilder xml, int level)  {
          throw new NullPointerException("A null value cannot be represented in an XML property list.");
      }
  
      @Override
      void toBinary(BinaryPropertyListWriter out) throws IOException {
          out.write(0x00);
      }
  
      @Override
      protected void toASCII(StringBuilder ascii, int level) {
          throw new NullPointerException("A null value cannot be represented in an ASCII property list.");
      }
  
      @Override
      protected void toASCIIGnuStep(StringBuilder ascii, int level) {
          throw new NullPointerException("A null value cannot be represented in an ASCII property list.");
      }
  
      @Override
      public boolean equals(Object obj) {
          return obj == NULL;
      }
  
      @Override
      public int compareTo(NSObject o) {
          if (o == NULL)
          {
              return 0;
          }
  
          return o == null ? 1 : -1;
      }
  }
  