org.perro.functions.mapper

Class IntTransformUtils

java.lang.Object

org.perro.functions.mapper.IntTransformUtils

public final class IntTransformUtils
extends java.lang.Object

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

Method Summary

Modifier and Type	Method and Description
static <T> int[]	flatMapToInt(java.util.Collection<T> objects, java.util.function.Function<T,int[]> function) Given a collection of objects of type <T>, and a Function<T, int[]>, returns an array of primitive ints.
static <T> int[]	flatMapToIntDistinct(java.util.Collection<T> objects, java.util.function.Function<T,int[]> function) Given a collection of objects of type <T>, and a Function<T, int[]>, returns an array of distinct primitive ints.
static int[]	intFlatMap(int[] ints, java.util.function.IntFunction<int[]> function) Given an array of ints, and an IntFunction<int[]> (a function that takes an int and returns an array of ints), returns an array of ints.
static int[]	intFlatMapDistinct(int[] ints, java.util.function.IntFunction<int[]> function) Given an array of ints, and an IntFunction<int[]> (a function that takes an int and returns an array of ints), returns an array of distinct primitive int values.
static <C extends java.util.Collection<java.lang.Integer>> C	intTransform(int[] ints, java.util.stream.Collector<java.lang.Integer,?,C> collector) Given an array of ints, and a Collector<Integer, ?, C>, returns a Collection<C> of Integer elements.
static <R> java.util.List<R>	intTransform(int[] ints, java.util.function.IntFunction<R> transformer) Given an array of ints, and an IntFunction<R> that transforms those ints into elements of type <R>, returns a List<R> of those elements.
static <U,C extends java.util.Collection<U>> C	intTransform(int[] ints, org.perro.functions.mapper.IntTransformerCollector<U,C> transformerCollector) Given an array of ints, and an IntTransformerCollector<U, C> that contains an IntFunction<U> to transform int 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.IntTransformerCollector<U,C>	intTransformAndThen(java.util.function.IntFunction<U> transformer, java.util.stream.Collector<U,?,C> collector) Builds an IntTransformerCollector<U, C> that contains an IntFunction<U> to transform primitive int 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>	intTransformDistinct(int[] ints, java.util.function.IntFunction<R> transformer) Given an array of ints, and an IntFunction<R> that transforms those ints 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>	intTransformToMap(int[] ints, org.perro.functions.mapper.IntKeyValueMapper<K,V> keyValueMapper) Given an array of primitive ints, and an IntKeyValueMapper containing an IntFunction to transform an int to a key of type <K>, and another IntFunction to transform an int to a value of type <V>, returns a Map<K, V>.
static <R> java.util.Set<R>	intTransformToSet(int[] ints, java.util.function.IntFunction<R> transformer) Given an array of ints, and an IntFunction<R> that transforms those ints into elements of type <R>, returns a Set<R> of those elements.
static int[]	intUnaryTransform(int[] ints, java.util.function.IntUnaryOperator operator) Given an array of ints, and an IntUnaryOperator that transforms each of those ints to another int, returns an array of the resulting int values.
static int[]	intUnaryTransformDistinct(int[] ints, java.util.function.IntUnaryOperator operator) Given an array of ints, and an IntUnaryOperator that transforms each of those ints to another int, returns an array of the resulting int 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

intUnaryTransform

public static int[] intUnaryTransform(int[] ints,
                                      java.util.function.IntUnaryOperator operator)

Given an array of ints, and an IntUnaryOperator that transforms each of those ints to another int, returns an array of the resulting int values.

Parameters:

ints - An array of ints to be transformed.

operator - An IntUnaryOperator that takes an int and transforms it to another int.

Returns:

An array of primitive transformed ints.

intUnaryTransformDistinct

public static int[] intUnaryTransformDistinct(int[] ints,
                                              java.util.function.IntUnaryOperator operator)

Given an array of ints, and an IntUnaryOperator that transforms each of those ints to another int, returns an array of the resulting int values, which will contain only distinct values.

Parameters:

ints - An array of ints to be transformed.

operator - An IntUnaryOperator that takes an int and transforms it to another int.

Returns:

An array of distinct, primitive, transformed ints.

intTransform

public static <R> java.util.List<R> intTransform(int[] ints,
                                                 java.util.function.IntFunction<R> transformer)

Given an array of ints, and an IntFunction<R> that transforms those ints 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:

ints - An array of ints to be transformed.

transformer - An IntFunction<R> that takes an int and transforms it to an element of type <R>.

Returns:

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

intTransformToSet

public static <R> java.util.Set<R> intTransformToSet(int[] ints,
                                                     java.util.function.IntFunction<R> transformer)

Given an array of ints, and an IntFunction<R> that transforms those ints 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:

ints - An array of ints to be transformed.

transformer - An IntFunction<R> that takes an int and transforms it to an element of type <R>.

Returns:

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

intTransform

public static <C extends java.util.Collection<java.lang.Integer>> C intTransform(int[] ints,
                                                                                 java.util.stream.Collector<java.lang.Integer,?,C> collector)

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

Type Parameters:

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

Parameters:

ints - An array of ints to be collected.

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

Returns:

A collection of type <C> of Integer values.

intTransformDistinct

public static <R> java.util.List<R> intTransformDistinct(int[] ints,
                                                         java.util.function.IntFunction<R> transformer)

Given an array of ints, and an IntFunction<R> that transforms those ints 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:

ints - An array of ints to be transformed.

transformer - An IntFunction<R> that takes an int and transforms it to an element of type <R>.

Returns:

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

intTransform

public static <U,C extends java.util.Collection<U>> C intTransform(int[] ints,
                                                                   org.perro.functions.mapper.IntTransformerCollector<U,C> transformerCollector)

Given an array of ints, and an IntTransformerCollector<U, C> that contains an IntFunction<U> to transform int 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 intTransformAndThen(IntFunction, 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:

ints - An array of ints to be transformed.

transformerCollector - A object containing a transformer IntFunction<U> to transform int 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 ints.

intFlatMap

public static int[] intFlatMap(int[] ints,
                               java.util.function.IntFunction<int[]> function)

Given an array of ints, and an IntFunction<int[]> (a function that takes an int and returns an array of ints), returns an array of ints.

Parameters:

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

function - An IntFunction that takes an int and returns an array of ints.

Returns:

An array of flat-mapped primitive ints.

intFlatMapDistinct

public static int[] intFlatMapDistinct(int[] ints,
                                       java.util.function.IntFunction<int[]> function)

Given an array of ints, and an IntFunction<int[]> (a function that takes an int and returns an array of ints), returns an array of distinct primitive int values.

Parameters:

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

function - An IntFunction that takes an int and returns an array of ints.

Returns:

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

flatMapToInt

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

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

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 ints.

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

Returns:

An array of primitive flat-mapped ints.

flatMapToIntDistinct

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

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

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 ints.

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

Returns:

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

intTransformAndThen

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

Builds an IntTransformerCollector<U, C> that contains an IntFunction<U> to transform primitive int 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 intTransform(int[], IntTransformerCollector).

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 - An IntFunction<U> to transform primitive int values into elements of type <U>.

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

Returns:

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

intTransformToMap

public static <K,V> java.util.Map<K,V> intTransformToMap(int[] ints,
                                                         org.perro.functions.mapper.IntKeyValueMapper<K,V> keyValueMapper)

Given an array of primitive ints, and an IntKeyValueMapper containing an IntFunction to transform an int to a key of type <K>, and another IntFunction to transform an int 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:

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

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

Returns:

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