org.perro.functions.mapper

Class DblTransformUtils

java.lang.Object

org.perro.functions.mapper.DblTransformUtils

public final class DblTransformUtils
extends java.lang.Object

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

Method Summary

Modifier and Type	Method and Description
static double[]	dblFlatMap(double[] doubles, java.util.function.DoubleFunction<double[]> function) Given an array of doubles, and a DoubleFunction<double[]> (a function that takes a double and returns an array of doubles), returns an array of doubles.
static double[]	dblFlatMapDistinct(double[] doubles, java.util.function.DoubleFunction<double[]> function) Given an array of doubles, and a DoubleFunction<double[]> (a function that takes a double and returns an array of doubles), returns an array of distinct primitive double values.
static <C extends java.util.Collection<java.lang.Double>> C	dblTransform(double[] doubles, java.util.stream.Collector<java.lang.Double,?,C> collector) Given an array of doubles, and a Collector<Double, ?, C>, returns a Collection<C> of Double elements.
static <U,C extends java.util.Collection<U>> C	dblTransform(double[] doubles, org.perro.functions.mapper.DblTransformerCollector<U,C> transformerCollector) Given an array of doubles, and a DblTransformerCollector<U, C> that contains a DoubleFunction<U> to transform double values into elements of type <U>, and a Collector<U, ?, C>, returns a collection of type <C> of those elements.
static <R> java.util.List<R>	dblTransform(double[] doubles, java.util.function.DoubleFunction<R> transformer) Given an array of doubles, and a DoubleFunction<R> that transforms those doubles into elements of type <R>, returns a List<R> of those elements.
static <U,C extends java.util.Collection<U>> org.perro.functions.mapper.DblTransformerCollector<U,C>	dblTransformAndThen(java.util.function.DoubleFunction<U> transformer, java.util.stream.Collector<U,?,C> collector) Builds a DblTransformerCollector<U, C> that contains a DoubleFunction<U> to transform primitive double 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>	dblTransformDistinct(double[] doubles, java.util.function.DoubleFunction<R> transformer) Given an array of doubles, and a DoubleFunction<R> that transforms those doubles to 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>	dblTransformToMap(double[] doubles, org.perro.functions.mapper.DblKeyValueMapper<K,V> keyValueMapper) Given an array of primitive doubles, and a DblKeyValueMapper containing a DoubleFunction to transform a double to a key of type <K>, and another DoubleFunction to transform a double to a value of type <V>, returns a Map<K, V>.
static <R> java.util.Set<R>	dblTransformToSet(double[] doubles, java.util.function.DoubleFunction<R> transformer) Given an array of doubles, and a DoubleFunction<R> that transforms those doubles to an element of type <R>, returns a Set<R> of those elements.
static double[]	dblUnaryTransform(double[] doubles, java.util.function.DoubleUnaryOperator operator) Given an array of doubles, and a DoubleUnaryOperator that transforms each of those doubles to another double, returns an array of the resulting double values.
static double[]	dblUnaryTransformDistinct(double[] doubles, java.util.function.DoubleUnaryOperator operator) Given an array of doubles, and a DoubleUnaryOperator that transforms each of those doubles to another double, returns an array of the resulting double values, which will contain only distinct values.
static <T> double[]	flatMapToDbl(java.util.Collection<T> objects, java.util.function.Function<T,double[]> function) Given a collection of objects of type <T>, and a Function<T, double[]>, returns an array of primitive doubles.
static <T> double[]	flatMapToDblDistinct(java.util.Collection<T> objects, java.util.function.Function<T,double[]> function) Given a collection of objects of type <T>, and a Function<T, double[]>, returns an array of distinct primitive doubles.

Methods inherited from class java.lang.Object

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

Method Detail

dblUnaryTransform

public static double[] dblUnaryTransform(double[] doubles,
                                         java.util.function.DoubleUnaryOperator operator)

Given an array of doubles, and a DoubleUnaryOperator that transforms each of those doubles to another double, returns an array of the resulting double values.

Parameters:

doubles - An array of doubles to be transformed.

operator - A DoubleUnaryOperator that takes a double and transforms it to another double.

Returns:

An array of primitive transformed doubles.

dblUnaryTransformDistinct

public static double[] dblUnaryTransformDistinct(double[] doubles,
                                                 java.util.function.DoubleUnaryOperator operator)

Given an array of doubles, and a DoubleUnaryOperator that transforms each of those doubles to another double, returns an array of the resulting double values, which will contain only distinct values.

Parameters:

doubles - An array of doubles to be transformed.

operator - A DoubleUnaryOperator that takes a double and transforms it to another double.

Returns:

An array of distinct, primitive, transformed doubles.

dblTransform

public static <R> java.util.List<R> dblTransform(double[] doubles,
                                                 java.util.function.DoubleFunction<R> transformer)

Given an array of doubles, and a DoubleFunction<R> that transforms those doubles 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:

doubles - An array of doubles to be transformed.

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

Returns:

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

dblTransformToSet

public static <R> java.util.Set<R> dblTransformToSet(double[] doubles,
                                                     java.util.function.DoubleFunction<R> transformer)

Given an array of doubles, and a DoubleFunction<R> that transforms those doubles to an element of type <R>, returns a Set<R> of those elements.

Type Parameters:

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

Parameters:

doubles - An array of doubles to be transformed.

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

Returns:

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

dblTransform

public static <C extends java.util.Collection<java.lang.Double>> C dblTransform(double[] doubles,
                                                                                java.util.stream.Collector<java.lang.Double,?,C> collector)

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

Type Parameters:

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

Parameters:

doubles - An array of doubles to be collected.

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

Returns:

A collection of type <C> of Double values.

dblTransformDistinct

public static <R> java.util.List<R> dblTransformDistinct(double[] doubles,
                                                         java.util.function.DoubleFunction<R> transformer)

Given an array of doubles, and a DoubleFunction<R> that transforms those doubles to 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:

doubles - An array of doubles to be transformed.

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

Returns:

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

dblTransform

public static <U,C extends java.util.Collection<U>> C dblTransform(double[] doubles,
                                                                   org.perro.functions.mapper.DblTransformerCollector<U,C> transformerCollector)

Given an array of doubles, and a DblTransformerCollector<U, C> that contains a DoubleFunction<U> to transform double 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 dblTransformAndThen(DoubleFunction, 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:

doubles - An array of doubles to be transformed.

transformerCollector - A object containing a transformer DoubleFunction<U> to transform double 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 doubles.

dblFlatMap

public static double[] dblFlatMap(double[] doubles,
                                  java.util.function.DoubleFunction<double[]> function)

Given an array of doubles, and a DoubleFunction<double[]> (a function that takes a double and returns an array of doubles), returns an array of doubles.

Parameters:

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

function - A DoubleFunction that takes a double and returns an array of doubles.

Returns:

An array of flat-mapped primitive doubles.

dblFlatMapDistinct

public static double[] dblFlatMapDistinct(double[] doubles,
                                          java.util.function.DoubleFunction<double[]> function)

Given an array of doubles, and a DoubleFunction<double[]> (a function that takes a double and returns an array of doubles), returns an array of distinct primitive double values.

Parameters:

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

function - A DoubleFunction that takes a double and returns an array of doubles.

Returns:

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

flatMapToDbl

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

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

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 doubles.

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

Returns:

An array of primitive flat-mapped doubles.

flatMapToDblDistinct

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

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

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 doubles.

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

Returns:

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

dblTransformAndThen

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

Builds a DblTransformerCollector<U, C> that contains a DoubleFunction<U> to transform primitive double 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 dblTransform(double[], DblTransformerCollector).

Type Parameters:

U - The type of the elements into which double 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 DoubleFunction<U> to transform primitive double 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 DoubleFunction<U> to transform primitive double values into elements of type <U>, and a Collector<U, ?, C> to append those elements into a collection of type <C>.

dblTransformToMap

public static <K,V> java.util.Map<K,V> dblTransformToMap(double[] doubles,
                                                         org.perro.functions.mapper.DblKeyValueMapper<K,V> keyValueMapper)

Given an array of primitive doubles, and a DblKeyValueMapper containing a DoubleFunction to transform a double to a key of type <K>, and another DoubleFunction to transform a double 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:

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

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

Returns:

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