Package it.unimi.dsi.fastutil.objects

Class Reference2ReferenceFunctions.Singleton<K,V>

java.lang.Object

it.unimi.dsi.fastutil.objects.AbstractReference2ReferenceFunction<K,V>

it.unimi.dsi.fastutil.objects.Reference2ReferenceFunctions.Singleton<K,V>

All Implemented Interfaces:

Function<K,V>, Reference2ReferenceFunction<K,V>, Serializable, Cloneable, Function<K,V>

Direct Known Subclasses:

Reference2ReferenceMaps.Singleton

Enclosing class:

Reference2ReferenceFunctions

public static class Reference2ReferenceFunctions.Singleton<K,V>
extends AbstractReference2ReferenceFunction<K,V>
implements Serializable, Cloneable

An immutable class representing a type-specific singleton function. Note that the default return value is still settable.

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

This class may be useful to implement your own in case you subclass a type-specific function.

See Also:

• Serialized Form

Method Summary

Modifier and Type	Method	Description
Object	clone()
boolean	containsKey(Object k)	Returns true if this function contains a mapping for the specified key.
V	get(Object k)	Returns the value to which the given key is mapped.
V	getOrDefault(Object k, V defaultValue)	Returns the value associated by this function to the specified key, or give the specified value if not present.
int	size()	Returns the intended number of keys in this function, or -1 if no such number exists.

Methods inherited from class it.unimi.dsi.fastutil.objects.AbstractReference2ReferenceFunction

defaultReturnValue, defaultReturnValue

Methods inherited from class java.lang.Object

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

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

apply, clear

Methods inherited from interface java.util.function.Function

andThen, compose

Methods inherited from interface it.unimi.dsi.fastutil.objects.Reference2ReferenceFunction

andThenByte, andThenChar, andThenDouble, andThenFloat, andThenInt, andThenLong, andThenObject, andThenReference, andThenShort, composeByte, composeChar, composeDouble, composeFloat, composeInt, composeLong, composeObject, composeReference, composeShort, put, remove

Method Details

containsKey

public boolean containsKey(Object k)

Description copied from interface: Function

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<K,V>

Parameters:

k - the key.

Returns:

true if this function associates a value to key.

See Also:

• Map.containsKey(Object)

get

public V get(Object k)

Description copied from interface: Reference2ReferenceFunction

Returns the value to which the given key is mapped.

Specified by:

get in interface Function<K,V>

Specified by:

get in interface Reference2ReferenceFunction<K,V>

Parameters:

k - 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)

getOrDefault

public V getOrDefault(Object k,
 V defaultValue)

Description copied from interface: Reference2ReferenceFunction

Returns the value associated by this function to the specified key, or give the specified value if not present.

Specified by:

getOrDefault in interface Function<K,V>

Specified by:

getOrDefault in interface Reference2ReferenceFunction<K,V>

Parameters:

k - the key.

defaultValue - the value to return if not present.

Returns:

the corresponding value, or defaultValue if no value was present for the given key.

See Also:

• Function.getOrDefault(Object, Object)

size

public int size()

Description copied from interface: Function

Returns the intended number of keys in this function, or -1 if no such number exists.

Most function implementations will have some knowledge of the intended number of keys in their domain. In some cases, however, this might not be possible. This default implementation, in particular, returns -1.

Specified by:

size in interface Function<K,V>

Returns:

the intended number of keys in this function, or -1 if that number is not available.

clone

public Object clone()