Package it.unimi.dsi.fastutil.objects

Class Object2IntMaps

java.lang.Object

it.unimi.dsi.fastutil.objects.Object2IntMaps

public final class Object2IntMaps
extends Object

A class providing static methods and objects that do useful things with type-specific maps.

See Also:

• Collections

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Object2IntMaps.EmptyMap<K>	An immutable class representing an empty type-specific map.
static class	Object2IntMaps.Singleton<K>	An immutable class representing a type-specific singleton map.
static class	Object2IntMaps.SynchronizedMap<K>	A synchronized wrapper class for maps.
static class	Object2IntMaps.UnmodifiableMap<K>	An unmodifiable wrapper class for maps.

Field Summary

Fields

Modifier and Type	Field	Description
static final Object2IntMaps.EmptyMap	EMPTY_MAP	An empty type-specific map (immutable).

Method Summary

Modifier and Type	Method	Description
static <K> Object2IntMap<K>	emptyMap()	Returns an empty map (immutable).
static <K> void	fastForEach(Object2IntMap<K> map, Consumer<? super Object2IntMap.Entry<K>> consumer)	Iterates quickly, if possible, on the entry set of the provided map.
static <K> ObjectIterable<Object2IntMap.Entry<K>>	fastIterable(Object2IntMap<K> map)	Returns an iterable yielding an iterator that will be fast, if possible, on the entry set of the provided map.
static <K> ObjectIterator<Object2IntMap.Entry<K>>	fastIterator(Object2IntMap<K> map)	Returns an iterator that will be fast, if possible, on the entry set of the provided map.
static <K> Object2IntMap<K>	singleton(K key, int value)	Returns a type-specific immutable map containing only the specified pair.
static <K> Object2IntMap<K>	singleton(K key, Integer value)	Returns a type-specific immutable map containing only the specified pair.
static <K> Object2IntMap<K>	synchronize(Object2IntMap<K> m)	Returns a synchronized type-specific map backed by the given type-specific map.
static <K> Object2IntMap<K>	synchronize(Object2IntMap<K> m, Object sync)	Returns a synchronized type-specific map backed by the given type-specific map, using an assigned object to synchronize.
static <K> Object2IntMap<K>	unmodifiable(Object2IntMap<? extends K> m)	Returns an unmodifiable type-specific map backed by the given type-specific map.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

EMPTY_MAP

public static final Object2IntMaps.EmptyMap EMPTY_MAP

An empty type-specific map (immutable). It is serializable and cloneable.

Method Details

fastIterator

public static <K>
ObjectIterator<Object2IntMap.Entry<K>> fastIterator(Object2IntMap<K> map)

Returns an iterator that will be fast, if possible, on the entry set of the provided map.

Parameters:

map - a map from which we will try to extract a (fast) iterator on the entry set.

Returns:

an iterator on the entry set of the given map that will be fast, if possible.

Since:

8.0.0

fastForEach

public static <K> void fastForEach(Object2IntMap<K> map,
 Consumer<? super Object2IntMap.Entry<K>> consumer)

Iterates quickly, if possible, on the entry set of the provided map.

Parameters:

map - a map on which we will try to iterate quickly.

consumer - the consumer that will be passed to Object2IntMap.FastEntrySet.fastForEach(Consumer), if possible, or to Iterable.forEach(Consumer).

Since:

8.1.0

fastIterable

public static <K>
ObjectIterable<Object2IntMap.Entry<K>> fastIterable(Object2IntMap<K> map)

Returns an iterable yielding an iterator that will be fast, if possible, on the entry set of the provided map.

Parameters:

map - a map from which we will try to extract an iterable yielding a (fast) iterator on the entry set.

Returns:

an iterable yielding an iterator on the entry set of the given map that will be fast, if possible.

Since:

8.0.0

emptyMap

public static <K> Object2IntMap<K> emptyMap()

Returns an empty map (immutable). It is serializable and cloneable.

This method provides a typesafe access to EMPTY_MAP.

Returns:

an empty map (immutable).

singleton

public static <K> Object2IntMap<K> singleton(K key,
 int value)

Returns a type-specific immutable map containing only the specified pair. The returned map is serializable and cloneable.

Note that albeit the returned map is immutable, its default return value may be changed.

Parameters:

key - the only key of the returned map.

value - the only value of the returned map.

Returns:

a type-specific immutable map containing just the pair <key,value>.

singleton

public static <K> Object2IntMap<K> singleton(K key,
 Integer value)

Returns a type-specific immutable map containing only the specified pair. The returned map is serializable and cloneable.

Note that albeit the returned map is immutable, its default return value may be changed.

Parameters:

key - the only key of the returned map.

value - the only value of the returned map.

Returns:

a type-specific immutable map containing just the pair <key,value>.

synchronize

public static <K> Object2IntMap<K> synchronize(Object2IntMap<K> m)

Returns a synchronized type-specific map backed by the given type-specific map.

Parameters:

m - the map to be wrapped in a synchronized map.

Returns:

a synchronized view of the specified map.

See Also:

• Collections.synchronizedMap(Map)

synchronize

public static <K> Object2IntMap<K> synchronize(Object2IntMap<K> m,
 Object sync)

Returns a synchronized type-specific map backed by the given type-specific map, using an assigned object to synchronize.

Parameters:

m - the map to be wrapped in a synchronized map.

sync - an object that will be used to synchronize the access to the map.

Returns:

a synchronized view of the specified map.

See Also:

• Collections.synchronizedMap(Map)

unmodifiable

public static <K> Object2IntMap<K> unmodifiable(Object2IntMap<? extends K> m)

Returns an unmodifiable type-specific map backed by the given type-specific map.

Parameters:

m - the map to be wrapped in an unmodifiable map.

Returns:

an unmodifiable view of the specified map.

See Also:

• Collections.unmodifiableMap(Map)