it.unimi.dsi.fastutil.objects

Class Object2ReferenceFunctions.EmptyFunction<K,V>

java.lang.Object

it.unimi.dsi.fastutil.objects.AbstractObject2ReferenceFunction<K,V>

it.unimi.dsi.fastutil.objects.Object2ReferenceFunctions.EmptyFunction<K,V>

All Implemented Interfaces:

Function<K,V>, Object2ReferenceFunction<K,V>, Serializable, Cloneable

Direct Known Subclasses:

Object2ReferenceMaps.EmptyMap

Enclosing class:

Object2ReferenceFunctions

public static class Object2ReferenceFunctions.EmptyFunction<K,V>
extends AbstractObject2ReferenceFunction<K,V>
implements Serializable, Cloneable

An immutable class representing an empty type-specific function.

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 and Description
void	clear() Removes all associations from this function (optional operation).
Object	clone()
boolean	containsKey(Object k) Returns true if this function contains a mapping for the specified key.
V	defaultReturnValue() Gets the default return value.
void	defaultReturnValue(V defRetValue) Sets the default return value.
V	get(Object k) Returns the value associated by this function to the specified key.
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.AbstractObject2ReferenceFunction

put, remove

Methods inherited from class java.lang.Object

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

Method Detail

get

public V get(Object k)

Description copied from interface: Function

Returns the value associated by this function to the specified key.

Specified by:

get in interface Function<K,V>

Parameters:

k - the key.

Returns:

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

See Also:

Map.get(Object)

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.

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)

defaultReturnValue

public V defaultReturnValue()

Description copied from interface: Object2ReferenceFunction

Gets the default return value.

Specified by:

defaultReturnValue in interface Object2ReferenceFunction<K,V>

Overrides:

defaultReturnValue in class AbstractObject2ReferenceFunction<K,V>

Returns:

the current default return value.

defaultReturnValue

public void defaultReturnValue(V defRetValue)

Description copied from interface: Object2ReferenceFunction

Sets the default return value. 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.

Specified by:

defaultReturnValue in interface Object2ReferenceFunction<K,V>

Overrides:

defaultReturnValue in class AbstractObject2ReferenceFunction<K,V>

Parameters:

defRetValue - the new default return value.

See Also:

Object2ReferenceFunction.defaultReturnValue()

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.

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.

clear

public void clear()

Description copied from interface: Function

Removes all associations from this function (optional operation).

Specified by:

clear in interface Function<K,V>

Overrides:

clear in class AbstractObject2ReferenceFunction<K,V>

See Also:

Map.clear()

clone

public Object clone()

Overrides:

clone in class Object