Package it.unimi.dsi.fastutil.objects

Class Reference2ReferenceMaps.EmptyMap<K,​V>

java.lang.Object
it.unimi.dsi.fastutil.objects.AbstractReference2ReferenceFunction<K,​V>
it.unimi.dsi.fastutil.objects.Reference2ReferenceFunctions.EmptyFunction<K,​V>
it.unimi.dsi.fastutil.objects.Reference2ReferenceMaps.EmptyMap<K,​V>
All Implemented Interfaces:
it.unimi.dsi.fastutil.Function<K,​V>, Reference2ReferenceFunction<K,​V>, Reference2ReferenceMap<K,​V>, java.io.Serializable, java.lang.Cloneable, java.util.function.Function<K,​V>, java.util.Map<K,​V>
Direct Known Subclasses:
Reference2ReferenceSortedMaps.EmptySortedMap
Enclosing class:
Reference2ReferenceMaps
public static class Reference2ReferenceMaps.EmptyMap<K,​V>
extends Reference2ReferenceFunctions.EmptyFunction<K,​V>
implements Reference2ReferenceMap<K,​V>, java.io.Serializable, java.lang.Cloneable
An immutable class representing an empty type-specific map.

This class may be useful to implement your own in case you subclass a type-specific map.

See Also:
Serialized Form

  • Method Details

    • containsValue

      public boolean containsValue​(java.lang.Object v)
      Specified by:
      containsValue in interface java.util.Map<K,​V>

    • getOrDefault

      public V getOrDefault​(java.lang.Object key, V defaultValue)
      Description copied from interface: Reference2ReferenceFunction
      Returns the value associated by this function to the specified key, or give the specified value if not present.
      Specified by:
      getOrDefault in interface it.unimi.dsi.fastutil.Function<K,​V>
      Specified by:
      getOrDefault in interface java.util.Map<K,​V>
      Specified by:
      getOrDefault in interface Reference2ReferenceFunction<K,​V>
      Specified by:
      getOrDefault in interface Reference2ReferenceMap<K,​V>
      Overrides:
      getOrDefault in class Reference2ReferenceFunctions.EmptyFunction<K,​V>
      Parameters:
      key - the key.
      defaultValue - the value to return if not present.
      Returns:
      the corresponding value, or defaultValue if no value was present for the given key.
      See Also:
      Function.getOrDefault(Object, Object)

    • putAll

      public void putAll​(java.util.Map<? extends K,​? extends V> m)
      Specified by:
      putAll in interface java.util.Map<K,​V>

    • reference2ReferenceEntrySet

      public it.unimi.dsi.fastutil.objects.ObjectSet<Reference2ReferenceMap.Entry<K,​V>> reference2ReferenceEntrySet()
      Description copied from interface: Reference2ReferenceMap
      Returns a type-specific set view of the mappings contained in this map.

      This method is necessary because there is no inheritance along type parameters: it is thus impossible to strengthen Map.entrySet() so that it returns an ObjectSet of type-specific entries (the latter makes it possible to access keys and values with type-specific methods).

      Specified by:
      reference2ReferenceEntrySet in interface Reference2ReferenceMap<K,​V>
      Returns:
      a type-specific set view of the mappings contained in this map.
      See Also:
      Map.entrySet()

    • keySet

      public ReferenceSet<K> keySet()
      Description copied from interface: Reference2ReferenceMap
      Specified by:
      keySet in interface java.util.Map<K,​V>
      Specified by:
      keySet in interface Reference2ReferenceMap<K,​V>
      Returns:
      a set view of the keys contained in this map.
      See Also:
      Map.keySet()

    • values

      public ReferenceCollection<V> values()
      Description copied from interface: Reference2ReferenceMap
      Specified by:
      values in interface java.util.Map<K,​V>
      Specified by:
      values in interface Reference2ReferenceMap<K,​V>
      Returns:
      a set view of the values contained in this map.
      See Also:
      Map.values()

    • forEach

      public void forEach​(java.util.function.BiConsumer<? super K,​? super V> consumer)
      Specified by:
      forEach in interface java.util.Map<K,​V>
      Specified by:
      forEach in interface Reference2ReferenceMap<K,​V>

    • clone

      public java.lang.Object clone()
      Overrides:
      clone in class Reference2ReferenceFunctions.EmptyFunction<K,​V>

    • isEmpty

      public boolean isEmpty()
      Specified by:
      isEmpty in interface java.util.Map<K,​V>

    • hashCode

      public int hashCode()
      Specified by:
      hashCode in interface java.util.Map<K,​V>
      Overrides:
      hashCode in class Reference2ReferenceFunctions.EmptyFunction<K,​V>

    • equals

      public boolean equals​(java.lang.Object o)
      Specified by:
      equals in interface java.util.Map<K,​V>
      Overrides:
      equals in class Reference2ReferenceFunctions.EmptyFunction<K,​V>

    • toString

      public java.lang.String toString()
      Overrides:
      toString in class Reference2ReferenceFunctions.EmptyFunction<K,​V>