org.perro.functions.predicate

Class DblFilterUtils

java.lang.Object

org.perro.functions.predicate.DblFilterUtils

public final class DblFilterUtils
extends java.lang.Object

Convenience methods for filtering arrays of double primitives, without having to spell out the entire stream->filter->collect process.

Method Summary

Modifier and Type	Method and Description
static <C extends java.util.Collection<java.lang.Double>> C	dblFilter(double[] doubles, org.perro.functions.predicate.DoubleFilterCollector<C> filterCollector) Filters an array of doubles, based a predicate, into a collection.
static double[]	dblFilter(double[] doubles, java.util.function.DoublePredicate predicate) Filters an array of doubles, based a predicate, into another double array.
static <C extends java.util.Collection<java.lang.Double>> org.perro.functions.predicate.DoubleFilterCollector<C>	dblFilterAndThen(java.util.function.DoublePredicate filter, java.util.stream.Collector<java.lang.Double,?,C> collector) Builds an object combining a DoublePredicate and a Collector for use in the dblFilter(double[], DoubleFilterCollector) method.
static <C extends java.util.Collection<java.lang.Double>> C	dblFilterDistinct(double[] doubles, org.perro.functions.predicate.DoubleFilterCollector<C> filterCollector) Filters an array of doubles, based a predicate, into an array of distinct double values.
static double[]	dblFilterDistinct(double[] doubles, java.util.function.DoublePredicate predicate) Filters an array of doubles, based a predicate, into an array of distinct double values (according to Double.compare(double, double)).
static java.util.Set<java.lang.Double>	dblFilterToSet(double[] doubles, java.util.function.DoublePredicate predicate) Filters an array of doubles, based a predicate, into a set.

Methods inherited from class java.lang.Object

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

Method Detail

dblFilter

public static double[] dblFilter(double[] doubles,
                                 java.util.function.DoublePredicate predicate)

Filters an array of doubles, based a predicate, into another double array.

Parameters:

doubles - An array of doubles to be filtered.

predicate - A predicate with which to filter the doubles array.

Returns:

An array of doubles filtered from an array of double.

dblFilterToSet

public static java.util.Set<java.lang.Double> dblFilterToSet(double[] doubles,
                                                             java.util.function.DoublePredicate predicate)

Filters an array of doubles, based a predicate, into a set.

Parameters:

doubles - An array of doubles to be filtered.

predicate - A predicate with which to filter the doubles array.

Returns:

A Set of Double objects filtered from an array of double.

dblFilterDistinct

public static double[] dblFilterDistinct(double[] doubles,
                                         java.util.function.DoublePredicate predicate)

Filters an array of doubles, based a predicate, into an array of distinct double values (according to Double.compare(double, double)).

Parameters:

doubles - An array of doubles to be filtered.

predicate - A predicate with which to filter the doubles array.

Returns:

An array of distinct double values filtered, using the passed predicate, from the input array.

dblFilter

public static <C extends java.util.Collection<java.lang.Double>> C dblFilter(double[] doubles,
                                                                             org.perro.functions.predicate.DoubleFilterCollector<C> filterCollector)

Filters an array of doubles, based a predicate, into a collection. This overload takes an object that is built using the dblFilterAndThen(DoublePredicate, Collector) method, which allows you to specify both a predicate and a Collector to build any type of Collection as a result. For example:

     double[] doubles = ...
     List<Double> = DblFilterUtils.dblFilter(doubles, FilterUtils.dblFilterAndThen(DblPredicateUtils.dblGt(1.0D), Collectors.toCollection(LinkedList::new)));
 

Or, with static imports:

     dblFilter(doubles, dblFilterAndThen(dblGt(1.0D), toCollection(LinkedList::new)));
 

Type Parameters:

C - The type of the resulting Collection.

Parameters:

doubles - An array of doubles to be filtered.

filterCollector - An object containing a predicate with which to filter the doubles array, and a Collector to accumulate results into a Collection.

Returns:

A Collection of Double objects filtered from an array of double.

dblFilterDistinct

public static <C extends java.util.Collection<java.lang.Double>> C dblFilterDistinct(double[] doubles,
                                                                                     org.perro.functions.predicate.DoubleFilterCollector<C> filterCollector)

Filters an array of doubles, based a predicate, into an array of distinct double values. This overload takes an object that is built using the dblFilterAndThen(DoublePredicate, Collector) method, which allows you to specify both a DoublePredicate and a Collector to build any type of Collection as a result. For example:

     double[] doubles = ...
     List<Double> = DblFilterUtils.dblFilter(doubles, DblFilterUtils.dblFilterAndThen(DblPredicateUtils.dblGt(1.0D), Collectors.toCollection(LinkedList::new)));
 

Or, with static imports:

     List<Double> = dblFilter(doubles, dblFilterAndThen(dblGt(1.0D), toCollection(LinkedList::new)));
 

Type Parameters:

C - The type of the resulting Collection.

Parameters:

doubles - An array of doubles to be filtered.

filterCollector - An object containing a predicate with which to filter the doubles array, and a Collector to accumulate results into a Collection.

Returns:

An array of distinct double values filtered, using a predicate from the passed filterCollector, from the input array.

dblFilterAndThen

public static <C extends java.util.Collection<java.lang.Double>> org.perro.functions.predicate.DoubleFilterCollector<C> dblFilterAndThen(java.util.function.DoublePredicate filter,
                                                                                                                                         java.util.stream.Collector<java.lang.Double,?,C> collector)

Builds an object combining a DoublePredicate and a Collector for use in the dblFilter(double[], DoubleFilterCollector) method.

Type Parameters:

C - The type of the resulting collection.

Parameters:

filter - A Predicate for filtering elements from an array of doubles.

collector - A Collector to accumulate elements into a Collection of Double objects.

Returns:

A Collection of Double containing objects filtered from an array of double.