com.github.protobufel.multikeymap

Class Collectors

java.lang.Object

com.github.protobufel.multikeymap.Collectors

public final class Collectors
extends java.lang.Object

The utility class providing the MultiKeyMap and multiple sets' intersection related collectors.

Method Summary

Modifier and Type	Method and Description
static <T> java.util.Set<T>	intersectSets(java.lang.Iterable<? extends java.util.Set<T>> source, boolean parallel) Returns the Optional result of the intersection of all sets in the supplied Iterable.
static <T> java.util.stream.Collector<java.util.Set<T>,java.util.Set<T>,java.util.Set<T>>	setIntersecting(java.util.Set<T> smallestSet, boolean parallel) Gets a collector which intersects the stream of sets and returns the resulting set.
static <T> java.util.stream.Collector<java.util.Set<T>,java.util.Set<T>,java.util.Set<T>>	setIntersecting(java.util.function.Supplier<java.util.Set<T>> smallestSetSupplier, boolean parallel) Gets a collector which intersects the stream of sets and returns the resulting set.
static <T,E,K extends java.lang.Iterable<E>,V> java.util.stream.Collector<T,?,MultiKeyMap<E,K,V>>	toMultiKeyMap(java.util.function.Function<? super T,? extends K> keyMapper, java.util.function.Function<? super T,? extends V> valueMapper) Gets a MultiKeyMap producing collector.
static <T,E,K extends java.lang.Iterable<E>,V> java.util.stream.Collector<T,?,MultiKeyMap<E,K,V>>	toMultiKeyMap(java.util.function.Function<? super T,? extends K> keyMapper, java.util.function.Function<? super T,? extends V> valueMapper, java.util.function.BinaryOperator<V> mergeFunction) Gets a MultiKeyMap producing collector.
static <T,E,K extends java.lang.Iterable<E>,V,M extends MultiKeyMap<E,K,V>> java.util.stream.Collector<T,?,M>	toMultiKeyMap(java.util.function.Function<? super T,? extends K> keyMapper, java.util.function.Function<? super T,? extends V> valueMapper, java.util.function.BinaryOperator<V> mergeFunction, java.util.function.Supplier<M> multiKeyMapSupplier) Gets a MultiKeyMap producing collector.

Methods inherited from class java.lang.Object

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

Method Detail

intersectSets

public static <T> java.util.Set<T> intersectSets(java.lang.Iterable<? extends java.util.Set<T>> source,
                                                 boolean parallel)

Returns the Optional result of the intersection of all sets in the supplied Iterable.

Type Parameters:

T - the type of the elements of the sets

Parameters:

source - the Iterable of the sets to intersect with each other

parallel - use parallel processing if true, sequential if false

Returns:

the result of the intersection wrapped in Optional, or the empty Optional.

setIntersecting

public static <T> java.util.stream.Collector<java.util.Set<T>,java.util.Set<T>,java.util.Set<T>> setIntersecting(java.util.Set<T> smallestSet,
                                                                                                                 boolean parallel)

Gets a collector which intersects the stream of sets and returns the resulting set.

Type Parameters:

T - the type of the elements of the sets

Parameters:

smallestSet - the smallest in size element of the stream of sets, any if there are several of the same size

parallel - use parallel processing if true, sequential if false

Returns:

the collector to perform the intersection of all elements of the stream of sets

setIntersecting

public static <T> java.util.stream.Collector<java.util.Set<T>,java.util.Set<T>,java.util.Set<T>> setIntersecting(java.util.function.Supplier<java.util.Set<T>> smallestSetSupplier,
                                                                                                                 boolean parallel)

Gets a collector which intersects the stream of sets and returns the resulting set.

Type Parameters:

T - the type of the elements of the sets

Parameters:

smallestSetSupplier - the supplier of the smallest in size element of the stream of sets, any if there are several of the same size

parallel - use parallel processing if true, sequential if false

Returns:

the collector to perform the intersection of all elements of the stream of sets

toMultiKeyMap

public static <T,E,K extends java.lang.Iterable<E>,V> java.util.stream.Collector<T,?,MultiKeyMap<E,K,V>> toMultiKeyMap(java.util.function.Function<? super T,? extends K> keyMapper,
                                                                                                                       java.util.function.Function<? super T,? extends V> valueMapper)

Gets a MultiKeyMap producing collector.

Type Parameters:

T - the type of the stream elements

E - the type of the sub-keys of the MultiKeyMap

K - the type of the keys of the MultiKeyMap

V - the type of the values of the MultiKeyMap

Parameters:

keyMapper - the key producing mapping function

valueMapper - the value producing mapping function

Returns:

the MultiKeyMap producing collector

toMultiKeyMap

public static <T,E,K extends java.lang.Iterable<E>,V> java.util.stream.Collector<T,?,MultiKeyMap<E,K,V>> toMultiKeyMap(java.util.function.Function<? super T,? extends K> keyMapper,
                                                                                                                       java.util.function.Function<? super T,? extends V> valueMapper,
                                                                                                                       java.util.function.BinaryOperator<V> mergeFunction)

Gets a MultiKeyMap producing collector.

Type Parameters:

T - the type of the stream elements

E - the type of the sub-keys of the MultiKeyMap

K - the type of the keys of the MultiKeyMap

V - the type of the values of the MultiKeyMap

Parameters:

keyMapper - the key producing mapping function

valueMapper - the value producing mapping function

mergeFunction - the value merging function

Returns:

the MultiKeyMap producing collector

toMultiKeyMap

public static <T,E,K extends java.lang.Iterable<E>,V,M extends MultiKeyMap<E,K,V>> java.util.stream.Collector<T,?,M> toMultiKeyMap(java.util.function.Function<? super T,? extends K> keyMapper,
                                                                                                                                   java.util.function.Function<? super T,? extends V> valueMapper,
                                                                                                                                   java.util.function.BinaryOperator<V> mergeFunction,
                                                                                                                                   java.util.function.Supplier<M> multiKeyMapSupplier)

Gets a MultiKeyMap producing collector.

Type Parameters:

T - the type of the stream elements

E - the type of the sub-keys of the MultiKeyMap

K - the type of the keys of the MultiKeyMap

V - the type of the values of the MultiKeyMap

Parameters:

keyMapper - the key producing mapping function

valueMapper - the value producing mapping function

mergeFunction - the value merging function

multiKeyMapSupplier - the MultiKeyMap supplier

Returns:

the MultiKeyMap producing collector