Module org.tquadrat.foundation.util

Package org.tquadrat.foundation.util

Interface LazyMap<K,V>

Type Parameters:

K - The type of keys maintained by this map.

V - The type of mapped values.

All Superinterfaces:

Map<K,V>

All Known Subinterfaces:

LazySortedMap<K,V>

All Known Implementing Classes:

LazyMapImpl, LazySortedMapImpl

@ClassVersion(sourceVersion="$Id: LazyMap.java 1032 2022-04-10 17:27:44Z tquadrat $")
@API(status=STABLE,
     since="0.0.5")
public sealed interface LazyMap<K,V>
extends Map<K,V>
permits LazySortedMap<K,V>, LazyMapImpl<K,V>

The interface for a Map that will be initialised only when required.

Note:

• There is no implementation of a map() method in this interface because it is assumed that this would be confusing: such a map() method would operate on the whole map that is wrapped by this value, and not on an entry as one would expect. Refer to .

Author:

Thomas Thrien (thomas.thrien@tquadrat.org)

Version:

$Id: LazyMap.java 1032 2022-04-10 17:27:44Z tquadrat $

Since:

0.0.5

See Also:

• Lazy

UML Diagram

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UML Diagram for "org.tquadrat.foundation.util.LazyMap"

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Nested Class Summary

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K,V>

Method Summary

Modifier and Type	Method	Description
void	ifPresent(Consumer<? super Map<K,V>> consumer)	If this LazyMap instance has been initialised already, the provided Consumer will be executed; otherwise nothing happens.
void	init()	Forces the initialisation of this LazyMap instance.
boolean	isPresent()	Checks whether this LazyMap instance has been initialised already.
static <K, V> LazyMap<K,V>	of(Map<K,V> value)	Creates a new LazyMap instance that is already initialised.
static <K, V> LazyMap<K,V>	use(boolean doPopulate, Supplier<? extends Map<K,V>> supplier)	Creates a new LazyMap instance that uses the given supplier to initialise.
static <K, V> LazyMap<K,V>	use(Supplier<? extends Map<K,V>> supplier)	Creates a new LazyMap instance that uses the given supplier to create the internal map, but that supplier does not provide values on initialisation.

Methods inherited from interface java.util.Map

clear, compute, computeIfAbsent, computeIfPresent, containsKey, containsValue, entrySet, equals, forEach, get, getOrDefault, hashCode, isEmpty, keySet, merge, put, putAll, putIfAbsent, remove, remove, replace, replace, replaceAll, size, values

Method Details

ifPresent

void ifPresent(Consumer<? super Map<K,V>> consumer)

If this LazyMap instance has been initialised already, the provided Consumer will be executed; otherwise nothing happens.

Parameters:

consumer - The consumer.

init

void init()

Forces the initialisation of this LazyMap instance.

isPresent

boolean isPresent()

Checks whether this LazyMap instance has been initialised already.

Returns:

true if the instance was initialised, false otherwise.

of

@API(status=STABLE,
     since="0.0.5")
static <K,
V> LazyMap<K,V> of(Map<K,V> value)

Creates a new LazyMap instance that is already initialised.

Type Parameters:

K - The type of keys maintained by this map.

V - The type of mapped values.

Parameters:

value - The value.

Returns:

The new instance.

use

@API(status=STABLE,
     since="0.0.5")
static <K,
V> LazyMap<K,V> use(Supplier<? extends Map<K,V>> supplier)

Creates a new LazyMap instance that uses the given supplier to create the internal map, but that supplier does not provide values on initialisation.

Type Parameters:

K - The type of keys maintained by this map.

V - The type of mapped values.

Parameters:

supplier - The supplier that initialises for the new instance of LazyMap when needed.

Returns:

The new instance.

use

@API(status=STABLE,
     since="0.0.5")
static <K,
V> LazyMap<K,V> use(boolean doPopulate,
 Supplier<? extends Map<K,V>> supplier)

Creates a new LazyMap instance that uses the given supplier to initialise.

Type Parameters:

K - The type of keys maintained by this map.

V - The type of mapped values.

Parameters:

doPopulate - true if the provided supplier will put entries to the map on initialisation, false if it will create an empty map.

supplier - The supplier that initialises for the new instance of LazyMap when needed.

Returns:

The new instance.