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      1 /*
      2  * Copyright (C) 2008 The Guava Authors
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  * http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.google.common.collect.testing.features;
     18 
     19 import com.google.common.annotations.GwtCompatible;
     20 import com.google.common.collect.testing.Helpers;
     21 
     22 import java.lang.annotation.Inherited;
     23 import java.lang.annotation.Retention;
     24 import java.lang.annotation.RetentionPolicy;
     25 import java.util.Map;
     26 import java.util.Set;
     27 
     28 /**
     29  * Optional features of classes derived from {@code Map}.
     30  *
     31  * @author George van den Driessche
     32  */
     33 // Enum values use constructors with generic varargs.
     34 @SuppressWarnings("unchecked")
     35 @GwtCompatible
     36 public enum MapFeature implements Feature<Map> {
     37   /**
     38    * The map does not throw {@code NullPointerException} on calls such as
     39    * {@code containsKey(null)}, {@code get(null)},
     40    * {@code keySet().contains(null)} or {@code remove(null)}.
     41    */
     42   ALLOWS_NULL_KEY_QUERIES,
     43   ALLOWS_NULL_KEYS(ALLOWS_NULL_KEY_QUERIES),
     44   /**
     45    * The map does not throw {@code NullPointerException} on calls such as
     46    * {@code containsValue(null)}, {@code values().contains(null)} or
     47    * {@code values().remove(null)}.
     48    */
     49   ALLOWS_NULL_VALUE_QUERIES,
     50   ALLOWS_NULL_VALUES(ALLOWS_NULL_VALUE_QUERIES),
     51   /**
     52    * The map does not throw {@code NullPointerException} on calls such as
     53    * {@code entrySet().contains(null)} or {@code entrySet().remove(null)}
     54    */
     55   ALLOWS_NULL_ENTRY_QUERIES,
     56   /**
     57    * The map does not throw {@code NullPointerException} on any {@code null}
     58    * queries.
     59    *
     60    * @see #ALLOWS_NULL_KEY_QUERIES
     61    * @see #ALLOWS_NULL_VALUE_QUERIES
     62    * @see #ALLOWS_NULL_ENTRY_QUERIES
     63    */
     64   ALLOWS_ANY_NULL_QUERIES(
     65       ALLOWS_NULL_ENTRY_QUERIES,
     66       ALLOWS_NULL_KEY_QUERIES,
     67       ALLOWS_NULL_VALUE_QUERIES
     68   ),
     69   RESTRICTS_KEYS,
     70   RESTRICTS_VALUES,
     71   SUPPORTS_PUT,
     72   SUPPORTS_REMOVE,
     73   FAILS_FAST_ON_CONCURRENT_MODIFICATION,
     74   /**
     75    * Indicates that the constructor or factory method of a map, usually an
     76    * immutable map, throws an {@link IllegalArgumentException} when presented
     77    * with duplicate keys instead of discarding all but one.
     78    */
     79   REJECTS_DUPLICATES_AT_CREATION,
     80 
     81   GENERAL_PURPOSE(
     82       SUPPORTS_PUT,
     83       SUPPORTS_REMOVE
     84   );
     85 
     86   private final Set<Feature<? super Map>> implied;
     87 
     88   MapFeature(Feature<? super Map> ... implied) {
     89     this.implied = Helpers.copyToSet(implied);
     90   }
     91 
     92   @Override
     93   public Set<Feature<? super Map>> getImpliedFeatures() {
     94     return implied;
     95   }
     96 
     97   @Retention(RetentionPolicy.RUNTIME)
     98   @Inherited
     99   @TesterAnnotation
    100   public @interface Require {
    101     public abstract MapFeature[] value() default {};
    102     public abstract MapFeature[] absent() default {};
    103   }
    104 }
    105