Package it.unimi.dsi.fastutil.longs

Class Long2ReferenceFunctions

java.lang.Object

it.unimi.dsi.fastutil.longs.Long2ReferenceFunctions

public final class Long2ReferenceFunctions
extends Object

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

See Also:

• Function
• Collections

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Long2ReferenceFunctions.EmptyFunction<V>	An immutable class representing an empty type-specific function.
static class	Long2ReferenceFunctions.PrimitiveFunction<V>	An adapter for mapping generic total functions to partial primitive functions.
static class	Long2ReferenceFunctions.Singleton<V>	An immutable class representing a type-specific singleton function.
static class	Long2ReferenceFunctions.SynchronizedFunction<V>	A synchronized wrapper class for functions.
static class	Long2ReferenceFunctions.UnmodifiableFunction<V>	An unmodifiable wrapper class for functions.

Field Summary

Fields

Modifier and Type	Field	Description
static final Long2ReferenceFunctions.EmptyFunction	EMPTY_FUNCTION	An empty type-specific function (immutable).

Method Summary

Modifier and Type	Method	Description
static <V> Long2ReferenceFunction<V>	primitive(Function<? super Long,? extends V> f)	Returns a (partial) type-specific function based on the given total generic function.
static <V> Long2ReferenceFunction<V>	singleton(long key, V value)	Returns a type-specific immutable function containing only the specified pair.
static <V> Long2ReferenceFunction<V>	singleton(Long key, V value)	Returns a type-specific immutable function containing only the specified pair.
static <V> Long2ReferenceFunction<V>	synchronize(Long2ReferenceFunction<V> f)	Returns a synchronized type-specific function backed by the given type-specific function.
static <V> Long2ReferenceFunction<V>	synchronize(Long2ReferenceFunction<V> f, Object sync)	Returns a synchronized type-specific function backed by the given type-specific function, using an assigned object to synchronize.
static <V> Long2ReferenceFunction<V>	unmodifiable(Long2ReferenceFunction<? extends V> f)	Returns an unmodifiable type-specific function backed by the given type-specific function.

Methods inherited from class java.lang.Object

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

Field Details

EMPTY_FUNCTION

public static final Long2ReferenceFunctions.EmptyFunction EMPTY_FUNCTION

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

Method Details

singleton

public static <V> Long2ReferenceFunction<V> singleton(long key,
 V value)

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

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

Parameters:

key - the only key of the returned function.

value - the only value of the returned function.

Returns:

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

singleton

public static <V> Long2ReferenceFunction<V> singleton(Long key,
 V value)

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

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

Parameters:

key - the only key of the returned function.

value - the only value of the returned function.

Returns:

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

synchronize

public static <V> Long2ReferenceFunction<V> synchronize(Long2ReferenceFunction<V> f)

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

Parameters:

f - the function to be wrapped in a synchronized function.

Returns:

a synchronized view of the specified function.

See Also:

• Collections.synchronizedMap(java.util.Map)

synchronize

public static <V> Long2ReferenceFunction<V> synchronize(Long2ReferenceFunction<V> f,
 Object sync)

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

Parameters:

f - the function to be wrapped in a synchronized function.

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

Returns:

a synchronized view of the specified function.

See Also:

• Collections.synchronizedMap(java.util.Map)

unmodifiable

public static <V> Long2ReferenceFunction<V> unmodifiable(Long2ReferenceFunction<? extends V> f)

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

Parameters:

f - the function to be wrapped in an unmodifiable function.

Returns:

an unmodifiable view of the specified function.

See Also:

• Collections.unmodifiableMap(java.util.Map)

primitive

public static <V> Long2ReferenceFunction<V> primitive(Function<? super Long,? extends V> f)

Returns a (partial) type-specific function based on the given total generic function.

The returned function contains all keys which are not mapped to null. If the function already is a primitive function, it is returned without changes.

Warning: If the given function is a “widened” primitive function (e.g. an Int2IntFunction given to Short2ShortFunctions), it still is wrapped into a proxy, decreasing performance.

Parameters:

f - the function to be converted to a type-specific function.

Returns:

a primitive view of the specified function.

Throws:

NullPointerException - if f is null.

Since:

8.1.0

See Also:

• Long2ReferenceFunctions.PrimitiveFunction