it.unimi.dsi.fastutil.longs

Class Long2LongFunctions

java.lang.Object

it.unimi.dsi.fastutil.longs.Long2LongFunctions

public final class Long2LongFunctions
extends java.lang.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 and Description
static class	Long2LongFunctions.EmptyFunction An immutable class representing an empty type-specific function.
static class	Long2LongFunctions.PrimitiveFunction An adapter for mapping generic total functions to partial primitive functions.
static class	Long2LongFunctions.Singleton An immutable class representing a type-specific singleton function.
static class	Long2LongFunctions.SynchronizedFunction A synchronized wrapper class for functions.
static class	Long2LongFunctions.UnmodifiableFunction An unmodifiable wrapper class for functions.

Field Summary

Fields

Modifier and Type	Field and Description
static Long2LongFunctions.EmptyFunction	EMPTY_FUNCTION An empty type-specific function (immutable).

Method Summary

Modifier and Type	Method and Description
static Long2LongFunction	primitive(java.util.function.Function<? super java.lang.Long,? extends java.lang.Long> f) Returns a (partial) type-specific function based on the given total generic function.
static Long2LongFunction	singleton(long key, long value) Returns a type-specific immutable function containing only the specified pair.
static Long2LongFunction	singleton(java.lang.Long key, java.lang.Long value) Returns a type-specific immutable function containing only the specified pair.
static Long2LongFunction	synchronize(Long2LongFunction f) Returns a synchronized type-specific function backed by the given type-specific function.
static Long2LongFunction	synchronize(Long2LongFunction f, java.lang.Object sync) Returns a synchronized type-specific function backed by the given type-specific function, using an assigned object to synchronize.
static Long2LongFunction	unmodifiable(Long2LongFunction 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 Detail

EMPTY_FUNCTION

public static final Long2LongFunctions.EmptyFunction EMPTY_FUNCTION

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

Method Detail

singleton

public static Long2LongFunction singleton(long key,
                                          long 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 Long2LongFunction singleton(java.lang.Long key,
                                          java.lang.Long 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 Long2LongFunction synchronize(Long2LongFunction 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 Long2LongFunction synchronize(Long2LongFunction f,
                                            java.lang.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 Long2LongFunction unmodifiable(Long2LongFunction 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 Long2LongFunction primitive(java.util.function.Function<? super java.lang.Long,? extends java.lang.Long> 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:

java.lang.NullPointerException - if f is null.

Since:

8.1.0

See Also:

Long2LongFunctions.PrimitiveFunction