net.covers1624.quack.collection

Interface StreamableIterable<T>

All Superinterfaces:

java.lang.Iterable<T>

public interface StreamableIterable<T>
extends java.lang.Iterable<T>

An iterable capable of stream-like operations.

Whilst the Stream API is nice for some operations. There are some use cases where a simpler wrapped Iterable approach would be faster and more memory efficient, that's what this class aims to solve.

Created by covers1624 on 1/10/21.

Method Summary

Modifier and Type	Method and Description
default boolean	allMatch(java.util.function.Predicate<? super T> test) Check if all elements in this StreamableIterable match the given predicate.
default boolean	anyMatch(java.util.function.Predicate<? super T> test) Check if any elements in this StreamableIterable match the given predicate.
default int	count() Count the number of elements in this StreamableIterable.
default StreamableIterable<T>	distinct() Filter the elements in this StreamableIterable by their hashcode/equals.
static <T> StreamableIterable<T>	empty()
default StreamableIterable<T>	filter(java.util.function.Predicate<? super T> pred) Filter the elements in this StreamableIterable by matching a Predicate.
default StreamableIterable<T>	filterNot(java.util.function.Predicate<? super T> pred) Filter the elements in this StreamableIterable by matching a Predicate.
default java.util.Optional<T>	findFirst() Optionally get the first element within this StreamableIterable.
default java.util.Optional<T>	findLast() Optionally get the first element within this StreamableIterable.
default <R> StreamableIterable<R>	flatMap(java.util.function.Function<? super T,? extends java.lang.Iterable<? extends R>> func) Flat map the elements in this StreamableIterable.
default java.util.Optional<T>	fold(java.util.function.BinaryOperator<T> accumulator) Folds each element of this StreamableIterable into the previous.
default T	fold(T identity, java.util.function.BinaryOperator<T> accumulator) Folds each element of this StreamableIterable into the previous.
default StreamableIterable<T>	limit(int max) Limit the number of elements returned by this StreamableIterable to the given value.
default <R> StreamableIterable<R>	map(java.util.function.Function<? super T,? extends R> func) Transform the elements in this StreamableIterable.
default boolean	noneMatch(java.util.function.Predicate<? super T> test) Check if no elements in this StreamableIterable match the given predicate.
static <T> StreamableIterable<T>	of(java.lang.Iterable<T> itr)
default java.util.stream.Stream<T>	parallelStream() Convert this StreamableIterable to a parallel Stream.
default StreamableIterable<T>	peek(java.util.function.Consumer<T> action) Peek the elements of this StreamableIterable as they are consumed.
default StreamableIterable<T>	skip(int n) Skip n number of elements in this StreamableIterable.
default java.util.stream.Stream<T>	stream() Convert this StreamableIterable to a Stream.
default java.lang.Object[]	toArray() Collect this StreamableIterable to an array.
default T[]	toArray(T[] arr) Collect this StreamableIterable to an array.
default <K,V> java.util.HashMap<K,V>	toLinkedHashMap(java.util.function.Function<T,K> keyFunc, java.util.function.Function<T,V> valueFunc) Collect this StreamableIterable to a LinkedHashMap.
default <K,V> java.util.HashMap<K,V>	toLinkedHashMap(java.util.function.Function<T,K> keyFunc, java.util.function.Function<T,V> valueFunc, java.util.function.BinaryOperator<V> mergeFunc) Collect this StreamableIterable to a LinkedHashMap.
default java.util.LinkedList<T>	toLinkedList() Collect this StreamableIterable to a LinkedList.
default java.util.ArrayList<T>	toList() Collect this StreamableIterable to an ArrayList.
default <K,V> java.util.HashMap<K,V>	toMap(java.util.function.Function<T,K> keyFunc, java.util.function.Function<T,V> valueFunc) Collect this StreamableIterable to a HashMap.
default <K,V> java.util.HashMap<K,V>	toMap(java.util.function.Function<T,K> keyFunc, java.util.function.Function<T,V> valueFunc, java.util.function.BinaryOperator<V> mergeFunc) Collect this StreamableIterable to a HashMap.
default <K,V,M extends java.util.Map<K,V>> M	toMap(M map, java.util.function.Function<T,K> keyFunc, java.util.function.Function<T,V> valueFunc) Collect this StreamableIterable to a Map.
default <K,V,M extends java.util.Map<K,V>> M	toMap(M map, java.util.function.Function<T,K> keyFunc, java.util.function.Function<T,V> valueFunc, java.util.function.BinaryOperator<V> mergeFunc) Collect this StreamableIterable to a Map.
default java.util.HashSet<T>	toSet() Collect this StreamableIterable to a HashSet.

Methods inherited from interface java.lang.Iterable

forEach, iterator, spliterator

Method Detail

empty

static <T> StreamableIterable<T> empty()

of

static <T> StreamableIterable<T> of(java.lang.Iterable<T> itr)

filter

default StreamableIterable<T> filter(java.util.function.Predicate<? super T> pred)

Filter the elements in this StreamableIterable by matching a Predicate.

All elements which match this Predicate will be in the resulting StreamableIterable.

Parameters:

pred - The predicate.

Returns:

A wrapped StreamableIterable with the filter applied.

filterNot

default StreamableIterable<T> filterNot(java.util.function.Predicate<? super T> pred)

Filter the elements in this StreamableIterable by matching a Predicate.

All elements which do not match this Predicate will be in the resulting StreamableIterable.

Parameters:

pred - The predicate.

Returns:

A wrapped StreamableIterable with the filter applied.

map

default <R> StreamableIterable<R> map(java.util.function.Function<? super T,? extends R> func)

Transform the elements in this StreamableIterable.

Parameters:

func - The Function to transform with.

Returns:

A wrapped StreamableIterable with the mapped elements.

flatMap

default <R> StreamableIterable<R> flatMap(java.util.function.Function<? super T,? extends java.lang.Iterable<? extends R>> func)

Flat map the elements in this StreamableIterable.

Parameters:

func - The function to get/create the iterable for a given element.

Returns:

A wrapped StreamableIterable with the flat mapped elements.

distinct

default StreamableIterable<T> distinct()

Filter the elements in this StreamableIterable by their hashcode/equals.

Returns:

A wrapped StreamableIterable with the filtered elements.

peek

default StreamableIterable<T> peek(java.util.function.Consumer<T> action)

Peek the elements of this StreamableIterable as they are consumed.

Parameters:

action - The consumer.

Returns:

A wrapped StreamableIterable with the peek function applied.

limit

default StreamableIterable<T> limit(int max)

Limit the number of elements returned by this StreamableIterable to the given value.

Parameters:

max - The limit. -1 for infinite.

Returns:

A wrapped StreamableIterable with the max filter applied. In the event -1< is supplied, the same StreamableIterable will be provided. In the event 0 is supplied, an empty StreamableIterable will be provided.

skip

default StreamableIterable<T> skip(int n)

Skip n number of elements in this StreamableIterable.

Parameters:

n - The number of elements to skip.

Returns:

A wrapped StreamableIterable with the max filter applied. In the event 0 is supplied, the same StreamableIterable will be provided.

toArray

default java.lang.Object[] toArray()

Collect this StreamableIterable to an array.

Returns:

The array.

toArray

default T[] toArray(T[] arr)

Collect this StreamableIterable to an array.

Parameters:

arr - The array to add the elements to. If all elements to not fit in this array a new array will be returned of appropriate size.

Returns:

Either the array passed in or one of appropriate size with all elements of the Iterable.

fold

default T fold(T identity,
               java.util.function.BinaryOperator<T> accumulator)

Folds each element of this StreamableIterable into the previous.

Parameters:

identity - The starting element.

accumulator - The function to fold elements with.

Returns:

The result.

fold

default java.util.Optional<T> fold(java.util.function.BinaryOperator<T> accumulator)

Folds each element of this StreamableIterable into the previous.

Parameters:

accumulator - The function to fold elements with.

Returns:

The result. Empty if no elements exist.

count

default int count()

Count the number of elements in this StreamableIterable.

Returns:

The number of elements.

anyMatch

default boolean anyMatch(java.util.function.Predicate<? super T> test)

Check if any elements in this StreamableIterable match the given predicate.

Parameters:

test - The predicate.

Returns:

The result.

allMatch

default boolean allMatch(java.util.function.Predicate<? super T> test)

Check if all elements in this StreamableIterable match the given predicate.

Parameters:

test - The predicate.

Returns:

The result.

noneMatch

default boolean noneMatch(java.util.function.Predicate<? super T> test)

Check if no elements in this StreamableIterable match the given predicate.

Parameters:

test - The predicate.

Returns:

The result.

findFirst

default java.util.Optional<T> findFirst()

Optionally get the first element within this StreamableIterable.

Returns:

The last element.

findLast

default java.util.Optional<T> findLast()

Optionally get the first element within this StreamableIterable.

Returns:

The last element.

toList

default java.util.ArrayList<T> toList()

Collect this StreamableIterable to an ArrayList.

Returns:

The ArrayList.

toLinkedList

default java.util.LinkedList<T> toLinkedList()

Collect this StreamableIterable to a LinkedList.

Returns:

The LinkedList.

toSet

default java.util.HashSet<T> toSet()

Collect this StreamableIterable to a HashSet.

Returns:

The HashSet.

toMap

default <K,V> java.util.HashMap<K,V> toMap(java.util.function.Function<T,K> keyFunc,
                                           java.util.function.Function<T,V> valueFunc)

Collect this StreamableIterable to a HashMap. This method will always resolve the existing element on collision.

Parameters:

keyFunc - The function for extracting the key.

valueFunc - The function for extracting the value.

Returns:

The Map.

toMap

default <K,V> java.util.HashMap<K,V> toMap(java.util.function.Function<T,K> keyFunc,
                                           java.util.function.Function<T,V> valueFunc,
                                           java.util.function.BinaryOperator<V> mergeFunc)

Collect this StreamableIterable to a HashMap.

Parameters:

keyFunc - The function for extracting the key.

valueFunc - The function for extracting the value.

mergeFunc - The function for merging 2 values on collision. (Left existing, Right toAdd)

Returns:

The Map.

toLinkedHashMap

default <K,V> java.util.HashMap<K,V> toLinkedHashMap(java.util.function.Function<T,K> keyFunc,
                                                     java.util.function.Function<T,V> valueFunc)

Collect this StreamableIterable to a LinkedHashMap. This method will always resolve the existing element on collision.

Parameters:

keyFunc - The function for extracting the key.

valueFunc - The function for extracting the value.

Returns:

The Map.

toLinkedHashMap

default <K,V> java.util.HashMap<K,V> toLinkedHashMap(java.util.function.Function<T,K> keyFunc,
                                                     java.util.function.Function<T,V> valueFunc,
                                                     java.util.function.BinaryOperator<V> mergeFunc)

Collect this StreamableIterable to a LinkedHashMap.

Parameters:

keyFunc - The function for extracting the key.

valueFunc - The function for extracting the value.

mergeFunc - The function for merging 2 values on collision. (Left existing, Right toAdd)

Returns:

The Map.

toMap

default <K,V,M extends java.util.Map<K,V>> M toMap(M map,
                                                   java.util.function.Function<T,K> keyFunc,
                                                   java.util.function.Function<T,V> valueFunc)

Collect this StreamableIterable to a Map. This method will always resolve the existing element on collision.

Parameters:

map - The map to add the elements to.

keyFunc - The function for extracting the key.

valueFunc - The function for extracting the value.

Returns:

The same map that was passed in.

toMap

default <K,V,M extends java.util.Map<K,V>> M toMap(M map,
                                                   java.util.function.Function<T,K> keyFunc,
                                                   java.util.function.Function<T,V> valueFunc,
                                                   java.util.function.BinaryOperator<V> mergeFunc)

Collect this StreamableIterable to a Map.

Parameters:

map - The map to add the elements to.

keyFunc - The function for extracting the key.

valueFunc - The function for extracting the value.

mergeFunc - The function for merging 2 values on collision. (Left existing, Right toAdd)

Returns:

The same map that was passed in.

stream

default java.util.stream.Stream<T> stream()

Convert this StreamableIterable to a Stream.

Returns:

The Stream

parallelStream

default java.util.stream.Stream<T> parallelStream()

Convert this StreamableIterable to a parallel Stream.

Returns:

The Stream