Interface Object2ObjectMap<K,V>
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- All Superinterfaces:
Function<K,V>
,java.util.function.Function<K,V>
,java.util.Map<K,V>
,Object2ObjectFunction<K,V>
- All Known Subinterfaces:
Object2ObjectSortedMap<K,V>
- All Known Implementing Classes:
AbstractObject2ObjectMap
,AbstractObject2ObjectSortedMap
,Object2ObjectArrayMap
,Object2ObjectAVLTreeMap
,Object2ObjectLinkedOpenCustomHashMap
,Object2ObjectLinkedOpenHashMap
,Object2ObjectMaps.EmptyMap
,Object2ObjectMaps.Singleton
,Object2ObjectMaps.SynchronizedMap
,Object2ObjectMaps.UnmodifiableMap
,Object2ObjectOpenCustomHashMap
,Object2ObjectOpenHashMap
,Object2ObjectRBTreeMap
,Object2ObjectSortedMaps.EmptySortedMap
,Object2ObjectSortedMaps.Singleton
,Object2ObjectSortedMaps.SynchronizedSortedMap
,Object2ObjectSortedMaps.UnmodifiableSortedMap
public interface Object2ObjectMap<K,V> extends Object2ObjectFunction<K,V>, java.util.Map<K,V>
A type-specificMap
; provides some additional methods that use polymorphism to avoid (un)boxing, and handling of a default return value.Besides extending the corresponding type-specific function, this interface strengthens
Map.entrySet()
,keySet()
andvalues()
. Moreover, a number of methods, such assize()
,defaultReturnValue()
, etc., are un-defaulted as their function default do not make sense for a map. Maps returning entry sets of typeObject2ObjectMap.FastEntrySet
support also fast iteration.A submap or subset may or may not have an independent default return value (which however must be initialized to the default return value of the originator).
- See Also:
Map
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Nested Class Summary
Nested Classes Modifier and Type Interface Description static interface
Object2ObjectMap.Entry<K,V>
A type-specificMap.Entry
; provides some additional methods that use polymorphism to avoid (un)boxing.static interface
Object2ObjectMap.FastEntrySet<K,V>
An entry set providing fast iteration.
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Method Summary
All Methods Instance Methods Abstract Methods Default Methods Deprecated Methods Modifier and Type Method Description default void
clear()
Removes all of the mappings from this map (optional operation).default V
compute(K key, java.util.function.BiFunction<? super K,? super V,? extends V> remappingFunction)
Attempts to compute a mapping for the specified key and its current mapped value (ornull
if there is no current mapping).default V
computeIfAbsent(K key, Object2ObjectFunction<? super K,? extends V> mappingFunction)
If the specified key is not already associated with a value, attempts to compute its value using the given mapping function and enters it into this map, unless the key is not present in the given mapping function.default V
computeIfPresent(K key, java.util.function.BiFunction<? super K,? super V,? extends V> remappingFunction)
If the value for the specified key is present, attempts to compute a new mapping given the key and its current mapped value.default V
computeObjectIfAbsentPartial(K key, Object2ObjectFunction<? super K,? extends V> mappingFunction)
Deprecated.Please usecomputeIfAbsent()
instead.boolean
containsKey(java.lang.Object key)
Returns true if this function contains a mapping for the specified key.V
defaultReturnValue()
Gets the default return value.void
defaultReturnValue(V rv)
Sets the default return value (optional operation).default ObjectSet<java.util.Map.Entry<K,V>>
entrySet()
Returns a set view of the mappings contained in this map.default void
forEach(java.util.function.BiConsumer<? super K,? super V> consumer)
default V
getOrDefault(java.lang.Object key, V defaultValue)
Returns the value to which the specified key is mapped, or thedefaultValue
if this map contains no mapping for the key.ObjectSet<K>
keySet()
default V
merge(K key, V value, java.util.function.BiFunction<? super V,? super V,? extends V> remappingFunction)
If the specified key is not already associated with a value, associates it with the givenvalue
.ObjectSet<Object2ObjectMap.Entry<K,V>>
object2ObjectEntrySet()
Returns a type-specific set view of the mappings contained in this map.default V
put(K key, V value)
Adds a pair to the map (optional operation).default V
putIfAbsent(K key, V value)
If the specified key is not already associated with a value, associates it with the given value and returns the default return value, else returns the current value.default V
remove(java.lang.Object key)
Removes the mapping with the given key (optional operation).default boolean
remove(java.lang.Object key, java.lang.Object value)
Removes the entry for the specified key only if it is currently mapped to the specified value.default V
replace(K key, V value)
Replaces the entry for the specified key only if it is currently mapped to some value.default boolean
replace(K key, V oldValue, V newValue)
Replaces the entry for the specified key only if currently mapped to the specified value.int
size()
Returns the number of key/value mappings in this map.ObjectCollection<V>
values()
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Methods inherited from interface java.util.Map
computeIfAbsent, containsValue, equals, get, hashCode, isEmpty, putAll, replaceAll
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Methods inherited from interface it.unimi.dsi.fastutil.objects.Object2ObjectFunction
andThenByte, andThenChar, andThenDouble, andThenFloat, andThenInt, andThenLong, andThenObject, andThenReference, andThenShort, composeByte, composeChar, composeDouble, composeFloat, composeInt, composeLong, composeObject, composeReference, composeShort, get
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Method Detail
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size
int size()
Returns the number of key/value mappings in this map. If the map contains more thanInteger.MAX_VALUE
elements, returnsInteger.MAX_VALUE
.
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clear
default void clear()
Removes all of the mappings from this map (optional operation). The map will be empty after this call returns.
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defaultReturnValue
void defaultReturnValue(V rv)
Sets the default return value (optional operation). This value must be returned by type-specific versions ofget()
,put()
andremove()
to denote that the map does not contain the specified key. It must benull
by default.Warning: Changing this to a non-null value can have unforeseen consequences. Especially, it breaks compatibility with the specifications of Java's
Map
interface. It has to be used with great care and thorough study of all method comments is recommended.- Specified by:
defaultReturnValue
in interfaceObject2ObjectFunction<K,V>
- Parameters:
rv
- the new default return value.- See Also:
defaultReturnValue()
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defaultReturnValue
V defaultReturnValue()
Gets the default return value.- Specified by:
defaultReturnValue
in interfaceObject2ObjectFunction<K,V>
- Returns:
- the current default return value.
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object2ObjectEntrySet
ObjectSet<Object2ObjectMap.Entry<K,V>> object2ObjectEntrySet()
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 anObjectSet
of type-specific entries (the latter makes it possible to access keys and values with type-specific methods).- Returns:
- a type-specific set view of the mappings contained in this map.
- See Also:
Map.entrySet()
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entrySet
default ObjectSet<java.util.Map.Entry<K,V>> entrySet()
Returns a set view of the mappings contained in this map.
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put
default V put(K key, V value)
Adds a pair to the map (optional operation).This default implementation just delegates to the corresponding function method.
- Specified by:
put
in interfaceFunction<K,V>
- Specified by:
put
in interfacejava.util.Map<K,V>
- Specified by:
put
in interfaceObject2ObjectFunction<K,V>
- Parameters:
key
- the key.value
- the value.- Returns:
- the old value, or the default return value if no value was present for the given key.
- See Also:
Function.put(Object,Object)
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remove
default V remove(java.lang.Object key)
Removes the mapping with the given key (optional operation).This default implementation just delegates to the corresponding type-specific–function method.
- Specified by:
remove
in interfaceFunction<K,V>
- Specified by:
remove
in interfacejava.util.Map<K,V>
- Specified by:
remove
in interfaceObject2ObjectFunction<K,V>
- Parameters:
key
- the key.- Returns:
- the old value, or the default return value if no value was present for the given key.
- See Also:
Function.remove(Object)
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values
ObjectCollection<V> values()
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containsKey
boolean containsKey(java.lang.Object key)
Returns true if this function contains a mapping for the specified key.
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getOrDefault
default V getOrDefault(java.lang.Object key, V defaultValue)
Returns the value to which the specified key is mapped, or thedefaultValue
if this map contains no mapping for the key.- Specified by:
getOrDefault
in interfaceFunction<K,V>
- Specified by:
getOrDefault
in interfacejava.util.Map<K,V>
- Specified by:
getOrDefault
in interfaceObject2ObjectFunction<K,V>
- Parameters:
key
- the key.defaultValue
- the default mapping of the key.- Returns:
- the value to which the specified key is mapped, or the
defaultValue
if this map contains no mapping for the key. - Since:
- 8.0.0
- See Also:
Map.getOrDefault(Object, Object)
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putIfAbsent
default V putIfAbsent(K key, V value)
If the specified key is not already associated with a value, associates it with the given value and returns the default return value, else returns the current value.- Specified by:
putIfAbsent
in interfacejava.util.Map<K,V>
- Parameters:
key
- key with which the specified value is to be associated.value
- value to be associated with the specified key.- Returns:
- the previous value associated with the specified key, or the default return value if there was no mapping for the key.
- Since:
- 8.0.0
- See Also:
Map.putIfAbsent(Object, Object)
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remove
default boolean remove(java.lang.Object key, java.lang.Object value)
Removes the entry for the specified key only if it is currently mapped to the specified value.
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replace
default boolean replace(K key, V oldValue, V newValue)
Replaces the entry for the specified key only if currently mapped to the specified value.- Specified by:
replace
in interfacejava.util.Map<K,V>
- Parameters:
key
- key with which the specified value is associated.oldValue
- value expected to be associated with the specified key.newValue
- value to be associated with the specified key.- Returns:
true
if the value was replaced.- Since:
- 8.0.0
- See Also:
Map.replace(Object, Object, Object)
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replace
default V replace(K key, V value)
Replaces the entry for the specified key only if it is currently mapped to some value.- Specified by:
replace
in interfacejava.util.Map<K,V>
- Parameters:
key
- key with which the specified value is associated.value
- value to be associated with the specified key.- Returns:
- the previous value associated with the specified key, or the default return value if there was no mapping for the key.
- Since:
- 8.0.0
- See Also:
Map.replace(Object, Object)
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computeIfAbsent
default V computeIfAbsent(K key, Object2ObjectFunction<? super K,? extends V> mappingFunction)
If the specified key is not already associated with a value, attempts to compute its value using the given mapping function and enters it into this map, unless the key is not present in the given mapping function.This version of computeIfAbsent() uses a type-specific version of
fastutil
'sFunction
. SinceFunction
has acontainsKey()
method, it is possible to avoid adding a key by havingcontainsKey()
returnfalse
for that key.- Parameters:
key
- key with which the specified value is to be associated.mappingFunction
- the function to compute a value.- Returns:
- the current (existing or computed) value associated with the specified key.
- Since:
- 8.0.0
- See Also:
Map.computeIfAbsent(Object, java.util.function.Function)
- API Notes:
- all
computeIfAbsent()
methods have a different logic based on the argument; no delegation is performed, contrarily to other superficially similar methods such asIterator.forEachRemaining(java.util.function.Consumer<? super E>)
orList.replaceAll(java.util.function.UnaryOperator<E>)
.
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computeObjectIfAbsentPartial
@Deprecated default V computeObjectIfAbsentPartial(K key, Object2ObjectFunction<? super K,? extends V> mappingFunction)
Deprecated.Please usecomputeIfAbsent()
instead.
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computeIfPresent
default V computeIfPresent(K key, java.util.function.BiFunction<? super K,? super V,? extends V> remappingFunction)
If the value for the specified key is present, attempts to compute a new mapping given the key and its current mapped value.- Specified by:
computeIfPresent
in interfacejava.util.Map<K,V>
- Parameters:
key
- key with which the specified value is to be associated.remappingFunction
- the function to compute a value.- Returns:
- the new value associated with the specified key, or the default return value if none.
- Since:
- 8.0.0
- See Also:
Map.computeIfPresent(Object, java.util.function.BiFunction)
- API Notes:
- The JDK specification for this method equates not being associated with a value with being associated with {code null}. This is not the case for this method.
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compute
default V compute(K key, java.util.function.BiFunction<? super K,? super V,? extends V> remappingFunction)
Attempts to compute a mapping for the specified key and its current mapped value (ornull
if there is no current mapping).If the function returns
null
, the mapping is removed (or remains absent if initially absent). If the function itself throws an (unchecked) exception, the exception is rethrown, and the current mapping is left unchanged.- Specified by:
compute
in interfacejava.util.Map<K,V>
- Parameters:
key
- key with which the specified value is to be associated.remappingFunction
- the function to compute a value.- Returns:
- the new value associated with the specified key, or the default return value if none.
- Since:
- 8.0.0
- See Also:
Map.compute(Object, java.util.function.BiFunction)
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merge
default V merge(K key, V value, java.util.function.BiFunction<? super V,? super V,? extends V> remappingFunction)
If the specified key is not already associated with a value, associates it with the givenvalue
. Otherwise, replaces the associated value with the results of the given remapping function, or removes if the result isnull
.- Specified by:
merge
in interfacejava.util.Map<K,V>
- Parameters:
key
- key with which the resulting value is to be associated.value
- the value to be merged with the existing value associated with the key or, if no existing value is associated with the key, to be associated with the key.remappingFunction
- the function to recompute a value if present.- Returns:
- the new value associated with the specified key, or the default return value if no value is associated with the key.
- Since:
- 8.0.0
- See Also:
Map.merge(Object, Object, java.util.function.BiFunction)
- API Notes:
- The JDK specification for this method equates not being associated with a value with being associated with {code null}. This is not the case for this method.
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