org.perro.functions.mapper

Class LongTransformUtils

java.lang.Object

org.perro.functions.mapper.LongTransformUtils

public final class LongTransformUtils
extends java.lang.Object

Methods to transform an array of longs to a collection of elements of an arbitrary type, or to transform a collection of elements of an arbitrary type to an array of longs.

Method Summary

Modifier and Type	Method and Description
static <T> long[]	flatMapToLong(java.util.Collection<T> objects, java.util.function.Function<T,long[]> function) Given a collection of objects of type <T>, and a Function<T, long[]>, returns an array of primitive longs.
static <T> long[]	flatMapToLongDistinct(java.util.Collection<T> objects, java.util.function.Function<T,long[]> function) Given a collection of objects of type <T>, and a Function<T, long[]>, returns an array of distinct primitive longs.
static long[]	longFlatMap(long[] longs, java.util.function.LongFunction<long[]> function) Given an array of longs, and a LongFunction<int[]> (a function that takes a long and returns an array of longs), returns an array of longs.
static long[]	longFlatMapDistinct(long[] longs, java.util.function.LongFunction<long[]> function) Given an array of longs, and a LongFunction<long[]> (a function that takes a long and returns an array of longs), returns an array of distinct primitive long values.
static <C extends java.util.Collection<java.lang.Long>> C	longTransform(long[] longs, java.util.stream.Collector<java.lang.Long,?,C> collector) Given an array of longs, and a Collector<Long, ?, C>, returns a Collection<C> of Long elements.
static <R> java.util.List<R>	longTransform(long[] longs, java.util.function.LongFunction<R> transformer) Given an array of longs, and a LongFunction<R> that transforms those longs into elements of type <R>, returns a List<R> of those elements.
static <U,C extends java.util.Collection<U>> C	longTransform(long[] longs, org.perro.functions.mapper.LongTransformerCollector<U,C> transformerCollector) Given an array of longs, and a LongTransformerCollector<U, C> that contains a LongFunction<U> to transform long values into elements of type <U>, and a Collector<U, ?, C>, returns a collection of type <C> of those elements.
static <U,C extends java.util.Collection<U>> org.perro.functions.mapper.LongTransformerCollector<U,C>	longTransformAndThen(java.util.function.LongFunction<U> transformer, java.util.stream.Collector<U,?,C> collector) Builds a LongTransformerCollector<U, C> that contains a LongFunction<U> to transform primitive long values into elements of type <U>, and a Collector<U, ?, C> to collect those elements into a collection of type <C>.
static <R> java.util.List<R>	longTransformDistinct(long[] longs, java.util.function.LongFunction<R> transformer) Given an array of longs, and a LongFunction<R> that transforms those longs into elements of type <R>, returns a List<R> of those elements, which will contain only unique values (according to Object.equals(Object)).
static <K,V> java.util.Map<K,V>	longTransformToMap(long[] longs, org.perro.functions.mapper.LongKeyValueMapper<K,V> keyValueMapper) Given an array of primitive longs, and a LongKeyValueMapper containing a LongFunction to transform a long to a key of type <K>, and another LongFunction to transform a long to a value of type <V>, returns a Map<K, V>.
static <R> java.util.Set<R>	longTransformToSet(long[] longs, java.util.function.LongFunction<R> transformer) Given an array of longs, and a LongFunction<R> that transforms those longs into elements of type <R>, returns a Set<R> of those elements.
static long[]	longUnaryTransform(long[] longs, java.util.function.LongUnaryOperator operator) Given an array of longs, and a LongUnaryOperator that transforms each of those longs to another long, returns an array of the resulting long values.
static long[]	longUnaryTransformDistinct(long[] longs, java.util.function.LongUnaryOperator operator) Given an array of longs, and a LongUnaryOperator that transforms each of those longs to another long, returns an array of the resulting long values, which will contain only distinct values.

Methods inherited from class java.lang.Object

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

Method Detail

longUnaryTransform

public static long[] longUnaryTransform(long[] longs,
                                        java.util.function.LongUnaryOperator operator)

Given an array of longs, and a LongUnaryOperator that transforms each of those longs to another long, returns an array of the resulting long values.

Parameters:

longs - An array of ints to be transformed.

operator - A LongUnaryOperator that takes a long and transforms it to another long.

Returns:

An array of primitive transformed longs.

longUnaryTransformDistinct

public static long[] longUnaryTransformDistinct(long[] longs,
                                                java.util.function.LongUnaryOperator operator)

Given an array of longs, and a LongUnaryOperator that transforms each of those longs to another long, returns an array of the resulting long values, which will contain only distinct values.

Parameters:

longs - An array of ints to be transformed.

operator - A LongUnaryOperator that takes a long and transforms it to another long.

Returns:

An array of distinct, primitive, transformed longs.

longTransform

public static <R> java.util.List<R> longTransform(long[] longs,
                                                  java.util.function.LongFunction<R> transformer)

Given an array of longs, and a LongFunction<R> that transforms those longs into elements of type <R>, returns a List<R> of those elements.

Type Parameters:

R - The type of the elements in the resulting List.

Parameters:

longs - An array of longs to be transformed.

transformer - A LongFunction<R> that takes a long and transforms it to an element of type <R>.

Returns:

A List<R> of elements transformed from an array of primitive longs.

longTransformToSet

public static <R> java.util.Set<R> longTransformToSet(long[] longs,
                                                      java.util.function.LongFunction<R> transformer)

Given an array of longs, and a LongFunction<R> that transforms those longs into elements of type <R>, returns a Set<R> of those elements.

Type Parameters:

R - The type of the elements in the resulting Set.

Parameters:

longs - An array of longs to be transformed.

transformer - A LongFunction<R> that takes a long and transforms it to an element of type <R>.

Returns:

A Set<R> of elements transformed from an array of primitive longs.

longTransform

public static <C extends java.util.Collection<java.lang.Long>> C longTransform(long[] longs,
                                                                               java.util.stream.Collector<java.lang.Long,?,C> collector)

Given an array of longs, and a Collector<Long, ?, C>, returns a Collection<C> of Long elements.

Type Parameters:

C - The type of the collection of Long values returned.

Parameters:

longs - An array of longs to be collected.

collector - A Collector<Long, ?, C> that appends Long values into a collection of type <C>.

Returns:

A collection of type <C> of Long values.

longTransformDistinct

public static <R> java.util.List<R> longTransformDistinct(long[] longs,
                                                          java.util.function.LongFunction<R> transformer)

Given an array of longs, and a LongFunction<R> that transforms those longs into elements of type <R>, returns a List<R> of those elements, which will contain only unique values (according to Object.equals(Object)).

Type Parameters:

R - The type of the elements in the resulting List.

Parameters:

longs - An array of longs to be transformed.

transformer - A LongFunction<R> that takes a long and transforms it to an element of type <R>.

Returns:

A List<R> of elements transformed from an array of primitive longs, containing only distinct elements.

longTransform

public static <U,C extends java.util.Collection<U>> C longTransform(long[] longs,
                                                                    org.perro.functions.mapper.LongTransformerCollector<U,C> transformerCollector)

Given an array of longs, and a LongTransformerCollector<U, C> that contains a LongFunction<U> to transform long values into elements of type <U>, and a Collector<U, ?, C>, returns a collection of type <C> of those elements. The transformerCollection passed into this method should be created via a call to longTransformAndThen(LongFunction, Collector).

Type Parameters:

U - The type of the elements in the resulting Collection.

C - The type of the Collection of elements of type <U> returned.

Parameters:

longs - An array of longs to be transformed.

transformerCollector - A object containing a transformer LongFunction<U> to transform long values into elements of type <U>, and a Collector<U, ?, C> to put those elements into a resulting collection.

Returns:

A collection of type <C> of elements <U>, transformed from an array of primitive longs.

longFlatMap

public static long[] longFlatMap(long[] longs,
                                 java.util.function.LongFunction<long[]> function)

Given an array of longs, and a LongFunction<int[]> (a function that takes a long and returns an array of longs), returns an array of longs.

Parameters:

longs - An array of primitive longs to be flat-mapped into another array of longs.

function - A LongFunction that takes a long and returns an array of longs.

Returns:

An array of flat-mapped primitive longs.

longFlatMapDistinct

public static long[] longFlatMapDistinct(long[] longs,
                                         java.util.function.LongFunction<long[]> function)

Given an array of longs, and a LongFunction<long[]> (a function that takes a long and returns an array of longs), returns an array of distinct primitive long values.

Parameters:

longs - An array of primitive longs to be flat-mapped into another array of longs.

function - A LongFunction that takes a long and returns an array of longs.

Returns:

An array of distinct, primitive, flat-mapped longs.

flatMapToLong

public static <T> long[] flatMapToLong(java.util.Collection<T> objects,
                                       java.util.function.Function<T,long[]> function)

Given a collection of objects of type <T>, and a Function<T, long[]>, returns an array of primitive longs.

Type Parameters:

T - The type of the elements in the given objects collection.

Parameters:

objects - A collection of objects of type <T>, to be flat-mapped into an array of primitive longs.

function - A Function that takes an element of type <T> and returns a primitive long array.

Returns:

An array of primitive flat-mapped longs.

flatMapToLongDistinct

public static <T> long[] flatMapToLongDistinct(java.util.Collection<T> objects,
                                               java.util.function.Function<T,long[]> function)

Given a collection of objects of type <T>, and a Function<T, long[]>, returns an array of distinct primitive longs.

Type Parameters:

T - The type of the elements in the given objects collection.

Parameters:

objects - A collection of objects of type <T>, to be flat-mapped into an array of primitive longs.

function - A Function that takes an element of type <T> and returns a primitive long array.

Returns:

An array of distinct, primitive, flat-mapped longs.

longTransformAndThen

public static <U,C extends java.util.Collection<U>> org.perro.functions.mapper.LongTransformerCollector<U,C> longTransformAndThen(java.util.function.LongFunction<U> transformer,
                                                                                                                                  java.util.stream.Collector<U,?,C> collector)

Builds a LongTransformerCollector<U, C> that contains a LongFunction<U> to transform primitive long values into elements of type <U>, and a Collector<U, ?, C> to collect those elements into a collection of type <C>. Used to build the second parameter to longTransform(long[], LongTransformerCollector).

Type Parameters:

U - The type of the elements into which int values are to be transformed.

C - The type of a collection of elements of type <U>, into which a given collector will append elements.

Parameters:

transformer - A LongFunction<U> to transform primitive long values into elements of type <U>.

collector - A Collector<U, ?, C> to append elements into a collection of type <C>.

Returns:

An object containing a LongFunction<U> to transform primitive long values into elements of type <U>, and a Collector<U, ?, C> to append those elements into a collection of type <C>.

longTransformToMap

public static <K,V> java.util.Map<K,V> longTransformToMap(long[] longs,
                                                          org.perro.functions.mapper.LongKeyValueMapper<K,V> keyValueMapper)

Given an array of primitive longs, and a LongKeyValueMapper containing a LongFunction to transform a long to a key of type <K>, and another LongFunction to transform a long to a value of type <V>, returns a Map<K, V>.

Type Parameters:

K - The type of the key of the resulting Map<K, V>.

V - The type of the value of the resulting Map<K, V>.

Parameters:

longs - An array of primitive longs to be transformed into keys and values for the resulting Map<K, V>.

keyValueMapper - An object containing a LongFunction to transform a long to a key of type <K>, and another LongFunction to transform a long to a value of type <V>.

Returns:

A map whose keys and values are transformed from an array of longs.