All Superinterfaces:

Function<Long,Long>, Function<Long,Long>, LongUnaryOperator

All Known Subinterfaces:

Long2LongMap, Long2LongSortedMap

All Known Implementing Classes:

AbstractLong2LongFunction, AbstractLong2LongMap, AbstractLong2LongSortedMap, Long2LongArrayMap, Long2LongAVLTreeMap, Long2LongFunctions.EmptyFunction, Long2LongFunctions.PrimitiveFunction, Long2LongFunctions.Singleton, Long2LongFunctions.SynchronizedFunction, Long2LongFunctions.UnmodifiableFunction, Long2LongLinkedOpenHashMap, Long2LongMaps.EmptyMap, Long2LongMaps.Singleton, Long2LongMaps.SynchronizedMap, Long2LongMaps.UnmodifiableMap, Long2LongOpenCustomHashMap, Long2LongOpenHashMap, Long2LongRBTreeMap, Long2LongSortedMaps.EmptySortedMap, Long2LongSortedMaps.Singleton, Long2LongSortedMaps.SynchronizedSortedMap, Long2LongSortedMaps.UnmodifiableSortedMap

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
```
@FunctionalInterface
public interface Long2LongFunction
extends Function<Long,Long>, LongUnaryOperator
```
A type-specific Function; provides some additional methods that use polymorphism to avoid (un)boxing.
Type-specific versions of get(), put() and remove() cannot rely on null to denote absence of a key. Rather, they return a default return value, which is set to 0/false at creation, but can be changed using the defaultReturnValue() method.
For uniformity reasons, even functions returning objects implement the default return value (of course, in this case the default return value is initialized to null).
The default implementation of optional operations just throw an UnsupportedOperationException, except for the type-specific containsKey(), which return true. Generic versions of accessors delegate to the corresponding type-specific counterparts following the interface rules.
Warning: to fall in line as much as possible with the standard map interface, it is required that standard versions of get(), put() and remove() for maps with primitive-type keys or values return null to denote missing keys rather than wrap the default return value in an object. In case both keys and values are reference types, the default return value must be returned instead, thus violating the standard map interface when the default return value is not null.

See Also:

Function

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Default Methods Deprecated Methods
Modifier and Type	Method	Description
`default Long2ByteFunction`	`andThenByte(Long2ByteFunction after)`
`default Long2CharFunction`	`andThenChar(Long2CharFunction after)`
`default Long2DoubleFunction`	`andThenDouble(Long2DoubleFunction after)`
`default Long2FloatFunction`	`andThenFloat(Long2FloatFunction after)`
`default Long2IntFunction`	`andThenInt(Long2IntFunction after)`
`default Long2LongFunction`	`andThenLong(Long2LongFunction after)`
`default <T> Long2ObjectFunction<T>`	`andThenObject(Long2ObjectFunction<T> after)`
`default <T> Long2ReferenceFunction<T>`	`andThenReference(Long2ReferenceFunction<T> after)`
`default Long2ShortFunction`	`andThenShort(Long2ShortFunction after)`
`default long`	`applyAsLong(long operand)`
`default Byte2LongFunction`	`composeByte(Byte2LongFunction before)`
`default Char2LongFunction`	`composeChar(Char2LongFunction before)`
`default Double2LongFunction`	`composeDouble(Double2LongFunction before)`
`default Float2LongFunction`	`composeFloat(Float2LongFunction before)`
`default Int2LongFunction`	`composeInt(Int2LongFunction before)`
`default Long2LongFunction`	`composeLong(Long2LongFunction before)`
`default <T> Object2LongFunction<T>`	`composeObject(Object2LongFunction<T> before)`
`default <T> Reference2LongFunction<T>`	`composeReference(Reference2LongFunction<T> before)`
`default Short2LongFunction`	`composeShort(Short2LongFunction before)`
`default boolean`	`containsKey(long key)`	Returns true if this function contains a mapping for the specified key.
`default boolean`	`containsKey(Object key)`	Deprecated. Please use the corresponding type-specific method instead.
`default long`	`defaultReturnValue()`	Gets the default return value.
`default void`	`defaultReturnValue(long rv)`	Sets the default return value (optional operation).
`long`	`get(long key)`	Returns the value to which the given key is mapped.
`default Long`	`get(Object key)`	Deprecated. Please use the corresponding type-specific method instead.
`static Long2LongFunction`	`identity()`
`default long`	`put(long key, long value)`	Adds a pair to the map (optional operation).
`default Long`	`put(Long key, Long value)`	Deprecated. Please use the corresponding type-specific method instead.
`default long`	`remove(long key)`	Removes the mapping with the given key (optional operation).
`default Long`	`remove(Object key)`	Deprecated. Please use the corresponding type-specific method instead.

Methods inherited from interface it.unimi.dsi.fastutil.Function
apply, clear, size

Methods inherited from interface java.util.function.Function
andThen, compose

Methods inherited from interface java.util.function.LongUnaryOperator
andThen, compose

- Method Detail
  - applyAsLong
```
default long applyAsLong(long operand)
```
    Specified by:
    
    applyAsLong in interface LongUnaryOperator
    
    Since:
    
    8.0.0
  - put
```
default long put(long key,
                 long value)
```
    Adds a pair to the map (optional operation).
    
    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)
  - get
```
long get(long key)
```
    Returns the value to which the given key is mapped.
    
    Parameters:
    
    key - the key.
    
    Returns:
    
    the corresponding value, or the default return value if no value was present for the given key.
    
    See Also:
    
    Function.get(Object)
  - remove
```
default long remove(long key)
```
    Removes the mapping with the given key (optional operation).
    
    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)
  - put
```
@Deprecated
default Long put(Long key,
                 Long value)
```
    Deprecated.
    Please use the corresponding type-specific method instead.
    
    Associates the specified value with the specified key in this function (optional operation).
    
    Specified by:
    
    put in interface Function<Long,Long>
    
    Parameters:
    
    key - the key.
    
    value - the value.
    
    Returns:
    
    the old value, or null if no value was present for the given key.
    
    See Also:
    
    Map.put(Object,Object)
  - get
```
@Deprecated
default Long get(Object key)
```
    Deprecated.
    Please use the corresponding type-specific method instead.
    
    Returns the value associated by this function to the specified key.
    
    Specified by:
    
    get in interface Function<Long,Long>
    
    Parameters:
    
    key - the key.
    
    Returns:
    
    the corresponding value, or null if no value was present for the given key.
    
    See Also:
    
    Map.get(Object)
  - remove
```
@Deprecated
default Long remove(Object key)
```
    Deprecated.
    Please use the corresponding type-specific method instead.
    
    Removes this key and the associated value from this function if it is present (optional operation).
    
    Specified by:
    
    remove in interface Function<Long,Long>
    
    Parameters:
    
    key - the key.
    
    Returns:
    
    the old value, or null if no value was present for the given key.
    
    See Also:
    
    Map.remove(Object)
  - containsKey
```
default boolean containsKey(long key)
```
    Returns true if this function contains a mapping for the specified key.
    Note that for some kind of functions (e.g., hashes) this method will always return true. In particular, this default implementation always returns true.
    
    Parameters:
    
    key - the key.
    
    Returns:
    
    true if this function associates a value to key.
    
    See Also:
    
    Function.containsKey(Object)
  - containsKey
```
@Deprecated
default boolean containsKey(Object key)
```
    Deprecated.
    Please use the corresponding type-specific method instead.
    
    Returns true if this function contains a mapping for the specified key.
    Note that for some kind of functions (e.g., hashes) this method will always return true. This default implementation, in particular, always return true.
    
    Specified by:
    
    containsKey in interface Function<Long,Long>
    
    Parameters:
    
    key - the key.
    
    Returns:
    
    true if this function associates a value to key.
    
    See Also:
    
    Map.containsKey(Object)
  - defaultReturnValue
```
default void defaultReturnValue(long rv)
```
    Sets the default return value (optional operation). This value must be returned by type-specific versions of get(), put() and remove() to denote that the map does not contain the specified key. It must be 0/false/null by default.
    
    Parameters:
    
    rv - the new default return value.
    
    See Also:
    
    defaultReturnValue()
  - defaultReturnValue
```
default long defaultReturnValue()
```
    Gets the default return value.
    This default implementation just return the default null value of the type (null for objects, 0 for scalars, false for Booleans).
    
    Returns:
    
    the current default return value.
  - identity
```
static Long2LongFunction identity()
```
  - andThenByte
```
default Long2ByteFunction andThenByte(Long2ByteFunction after)
```
  - composeByte
```
default Byte2LongFunction composeByte(Byte2LongFunction before)
```
  - andThenShort
```
default Long2ShortFunction andThenShort(Long2ShortFunction after)
```
  - composeShort
```
default Short2LongFunction composeShort(Short2LongFunction before)
```
  - andThenInt
```
default Long2IntFunction andThenInt(Long2IntFunction after)
```
  - composeInt
```
default Int2LongFunction composeInt(Int2LongFunction before)
```
  - andThenLong
```
default Long2LongFunction andThenLong(Long2LongFunction after)
```
  - composeLong
```
default Long2LongFunction composeLong(Long2LongFunction before)
```
  - andThenChar
```
default Long2CharFunction andThenChar(Long2CharFunction after)
```
  - composeChar
```
default Char2LongFunction composeChar(Char2LongFunction before)
```
  - andThenFloat
```
default Long2FloatFunction andThenFloat(Long2FloatFunction after)
```
  - composeFloat
```
default Float2LongFunction composeFloat(Float2LongFunction before)
```
  - andThenDouble
```
default Long2DoubleFunction andThenDouble(Long2DoubleFunction after)
```
  - composeDouble
```
default Double2LongFunction composeDouble(Double2LongFunction before)
```
  - andThenObject
```
default <T> Long2ObjectFunction<T> andThenObject(Long2ObjectFunction<T> after)
```
  - composeObject
```
default <T> Object2LongFunction<T> composeObject(Object2LongFunction<T> before)
```
  - andThenReference
```
default <T> Long2ReferenceFunction<T> andThenReference(Long2ReferenceFunction<T> after)
```
  - composeReference
```
default <T> Reference2LongFunction<T> composeReference(Reference2LongFunction<T> before)
```

Interface Long2LongFunction

Method Summary

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

Methods inherited from interface java.util.function.Function

Methods inherited from interface java.util.function.LongUnaryOperator

Method Detail

applyAsLong

put

get

remove

put

get

remove

containsKey

containsKey

defaultReturnValue

defaultReturnValue

identity

andThenByte

composeByte

andThenShort

composeShort

andThenInt

composeInt

andThenLong

composeLong

andThenChar

composeChar

andThenFloat

composeFloat

andThenDouble

composeDouble

andThenObject

composeObject

andThenReference

composeReference