Package it.unimi.dsi.fastutil.objects

Class Reference2ObjectMaps.EmptyMap<K,V>

java.lang.Object

it.unimi.dsi.fastutil.objects.AbstractReference2ObjectFunction<K,V>

it.unimi.dsi.fastutil.objects.Reference2ObjectFunctions.EmptyFunction<K,V>

it.unimi.dsi.fastutil.objects.Reference2ObjectMaps.EmptyMap<K,V>

All Implemented Interfaces:

Function<K,V>, Reference2ObjectFunction<K,V>, Reference2ObjectMap<K,V>, Serializable, Cloneable, Function<K,V>, Map<K,V>

Direct Known Subclasses:

Reference2ObjectSortedMaps.EmptySortedMap

Enclosing class:

Reference2ObjectMaps

public static class Reference2ObjectMaps.EmptyMap<K,V>
extends Reference2ObjectFunctions.EmptyFunction<K,V>
implements Reference2ObjectMap<K,V>, Serializable, 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

Nested Class Summary

Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.objects.Reference2ObjectMap

Reference2ObjectMap.Entry<K,V>, Reference2ObjectMap.FastEntrySet<K,V>

Method Summary

Modifier and Type	Method	Description
Object	clone()
boolean	containsValue(Object v)
boolean	equals(Object o)
void	forEach(BiConsumer<? super K,? super V> consumer)
V	getOrDefault(Object key, V defaultValue)	Returns the value associated by this function to the specified key, or give the specified value if not present.
int	hashCode()
boolean	isEmpty()
ReferenceSet<K>	keySet()
void	putAll(Map<? extends K,? extends V> m)
ObjectSet<Reference2ObjectMap.Entry<K,V>>	reference2ObjectEntrySet()	Returns a type-specific set view of the mappings contained in this map.
String	toString()
ObjectCollection<V>	values()

Methods inherited from class it.unimi.dsi.fastutil.objects.Reference2ObjectFunctions.EmptyFunction

clear, containsKey, defaultReturnValue, defaultReturnValue, get, size

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface it.unimi.dsi.fastutil.Function

apply

Methods inherited from interface java.util.function.Function

andThen, compose

Methods inherited from interface java.util.Map

computeIfAbsent, get, replaceAll

Methods inherited from interface it.unimi.dsi.fastutil.objects.Reference2ObjectFunction

andThenByte, andThenChar, andThenDouble, andThenFloat, andThenInt, andThenLong, andThenObject, andThenReference, andThenShort, composeByte, composeChar, composeDouble, composeFloat, composeInt, composeLong, composeObject, composeReference, composeShort, get

Methods inherited from interface it.unimi.dsi.fastutil.objects.Reference2ObjectMap

clear, compute, computeIfAbsent, computeIfPresent, computeObjectIfAbsentPartial, containsKey, defaultReturnValue, defaultReturnValue, entrySet, merge, put, putIfAbsent, remove, remove, replace, replace, size

Method Details

containsValue

public boolean containsValue(Object v)

Specified by:

containsValue in interface Map<K,V>

getOrDefault

public V getOrDefault(Object key,
 V defaultValue)

Description copied from interface: Reference2ObjectFunction

Returns the value associated by this function to the specified key, or give the specified value if not present.

Specified by:

getOrDefault in interface Function<K,V>

Specified by:

getOrDefault in interface Map<K,V>

Specified by:

getOrDefault in interface Reference2ObjectFunction<K,V>

Specified by:

getOrDefault in interface Reference2ObjectMap<K,V>

Overrides:

getOrDefault in class Reference2ObjectFunctions.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(Map<? extends K,? extends V> m)

Specified by:

putAll in interface Map<K,V>

reference2ObjectEntrySet

public ObjectSet<Reference2ObjectMap.Entry<K,V>> reference2ObjectEntrySet()

Description copied from interface: Reference2ObjectMap

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:

reference2ObjectEntrySet in interface Reference2ObjectMap<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: Reference2ObjectMap

Specified by:

keySet in interface Map<K,V>

Specified by:

keySet in interface Reference2ObjectMap<K,V>

Returns:

a set view of the keys contained in this map.

See Also:

• Map.keySet()

values

public ObjectCollection<V> values()

Description copied from interface: Reference2ObjectMap

Specified by:

values in interface Map<K,V>

Specified by:

values in interface Reference2ObjectMap<K,V>

Returns:

a set view of the values contained in this map.

See Also:

• Map.values()

forEach

public void forEach(BiConsumer<? super K,? super V> consumer)

Specified by:

forEach in interface Map<K,V>

Specified by:

forEach in interface Reference2ObjectMap<K,V>

clone

public Object clone()

Overrides:

clone in class Reference2ObjectFunctions.EmptyFunction<K,V>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Map<K,V>

hashCode

public int hashCode()

Specified by:

hashCode in interface Map<K,V>

Overrides:

hashCode in class Reference2ObjectFunctions.EmptyFunction<K,V>

equals

public boolean equals(Object o)

Specified by:

equals in interface Map<K,V>

Overrides:

equals in class Reference2ObjectFunctions.EmptyFunction<K,V>

toString

public String toString()

Overrides:

toString in class Reference2ObjectFunctions.EmptyFunction<K,V>