Package net.sourceforge.pmd.util

Class DataMap<K>

java.lang.Object

net.sourceforge.pmd.util.DataMap<K>

Type Parameters:

K - Type of keys in this map.

public final class DataMap<K>
extends Object

An opaque, strongly typed heterogeneous data container. Data maps can be set to accept only a certain type of key, with the type parameter. The key can itself constrain the type of values, using its own type parameter T.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	DataMap.DataKey<K extends DataMap.DataKey<K,T>,T>	A key for type-safe access into a DataMap.
static class	DataMap.SimpleDataKey<T>

Method Summary

Modifier and Type	Method	Description
<T> T	compute(DataMap.DataKey<? extends K,T> key, Function<? super @Nullable T,? extends T> function)	Create or replace a mapping with a value computed from the current value (or null if missing).
<T> T	computeIfAbsent(DataMap.DataKey<? extends K,T> key, Supplier<? extends T> supplier)	Retrieve the value, or compute it if it is missing.
<T> @Nullable T	get(DataMap.DataKey<? extends K,? extends T> key)	Retrieves the data currently mapped to the key.
<T> T	getOrDefault(DataMap.DataKey<? extends K,? extends T> key, T defaultValue)
boolean	isSet(DataMap.DataKey<? extends K,?> key)	Returns true if the given key has a non-null value in the map.
<T> T	merge(DataMap.DataKey<? extends K,T> key, T value, BiFunction<? super @NonNull T,? super T,? extends T> function)
static <K> DataMap<K>	newDataMap()
<T> @Nullable T	set(DataMap.DataKey<? extends K,? super T> key, T data)	Set the mapping to the given data.
static <T> DataMap.SimpleDataKey<T>	simpleDataKey(String name)

Methods inherited from class java.lang.Object

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

Method Detail

set

public <T> @Nullable T set(DataMap.DataKey<? extends K,? super T> key,
                           T data)

Set the mapping to the given data.

Type Parameters:

T - Type of the data

Parameters:

key - Key

data - Data mapped to the key

Returns:

Previous value associated with the key (nullable)

get

public <T> @Nullable T get(DataMap.DataKey<? extends K,? extends T> key)

Retrieves the data currently mapped to the key.

Type Parameters:

T - Type of the data

Parameters:

key - Key

Returns:

Value associated with the key (nullable)

getOrDefault

public <T> T getOrDefault(DataMap.DataKey<? extends K,? extends T> key,
                          T defaultValue)

computeIfAbsent

public <T> T computeIfAbsent(DataMap.DataKey<? extends K,T> key,
                             Supplier<? extends T> supplier)

Retrieve the value, or compute it if it is missing.

Type Parameters:

T - Type of the data

Parameters:

key - Key

supplier - Supplier for a value

Returns:

Value associated with the key (as nullable as the

compute

public <T> T compute(DataMap.DataKey<? extends K,T> key,
                     Function<? super @Nullable T,? extends T> function)

Create or replace a mapping with a value computed from the current value (or null if missing).

Type Parameters:

T - Type of the data

Parameters:

key - Key

function - Supplier for a value

Returns:

Value returned by the parameter function

merge

public <T> T merge(DataMap.DataKey<? extends K,T> key,
                   T value,
                   BiFunction<? super @NonNull T,? super T,? extends T> function)

See Also:

Map.merge(Object, Object, BiFunction)

isSet

public boolean isSet(DataMap.DataKey<? extends K,?> key)

Returns true if the given key has a non-null value in the map.

Parameters:

key - Key

Returns:

True if some value is set

newDataMap

public static <K> DataMap<K> newDataMap()

simpleDataKey

public static <T> DataMap.SimpleDataKey<T> simpleDataKey(String name)