Package com.activeviam.collections

Interface ImmutableCollection<E>

Type Parameters:

E - The type of elements in this collection.

All Superinterfaces:

Iterable<E>

All Known Subinterfaces:

ImmutableList<E>, ImmutableSet<E>

All Known Implementing Classes:

ImmutableArrayList, ImmutableHashSet

public interface ImmutableCollection<E>
extends Iterable<E>

Immutable collections with a functional API.

Author:

ActiveViam

Method Summary

Modifier and Type	Method	Description
ImmutableCollection<E>	add(E e)	Create a new collection having the items of this collection plus one new item.
ImmutableCollection<E>	add(E first, E second, E... rest)	Create a new collection having the items of this collection plus new items.
default ImmutableCollection<E>	addAll(ImmutableCollection<E> items)	Create a new collection having the items of this collection plus items from another collection.
default ImmutableCollection<E>	addAll(E[] items)	Create a new collection having the items of this collection plus items from an array.
ImmutableCollection<E>	addAll(Collection<? extends E> items)	Create a new collection having the items of this collection plus items from another collection.
boolean	contains(E item)	Indicate if a given item is contained in this collection.
default boolean	doesNotContain(E item)	Indicate if a given item is not contained in this collection.
default boolean	every(Predicate<E> predicate)	Test if all the items of this collection match a given predicate.
default Optional<E>	find(Predicate<E> predicate)	Find the first item that matches a given predicate.
default int	findIndex(Predicate<E> predicate)	Find the number of iterations that were needed to find an item matching the given predicate.
default E	first()	Give the first item of this collection.
<R> ImmutableCollection<R>	flatMap(Function<E,Iterable<R>> mapper)	Flat map this collection.
default void	forEach(BiFunction<E,Integer,Boolean> loop)	Apply a function for each item of this collection until this function return false.
default void	forEachUntil(Predicate<E> loop)	Apply a function for each item of this collection until this function return false.
default <R> Optional<R>	getFirst(Function<E,Optional<R>> optionalResult)	When all the items of this collection can produce an optional result via a method, returns the first non empty result.
default boolean	isEmpty()	Indicate if this collection is empty.
default boolean	isNotEmpty()	Indicate if this collection contains at least one item.
default <R> R	reduce(BiFunction<R,E,R> reducer, R initialValue)	Apply a reducer to this collection.
int	size()	Give the size of this collection.
default boolean	some(Predicate<E> predicate)	Test if one of the items of this collection matches a given predicate.
E[]	toArray(E[] a)	Copy the content of this collection in an array.
default E[]	toArray(IntFunction<E[]> a)	Transforms this collection into an array.
Collection<E>	toCollection()	Create a read-only java util collection from this collection.

Methods inherited from interface java.lang.Iterable

forEach, iterator, spliterator

Method Detail

size

int size()

Give the size of this collection.

Returns:

The size of this collection.

add

ImmutableCollection<E> add(E e)

Create a new collection having the items of this collection plus one new item.

Parameters:

e - The items to add.

Returns:

The new collection.

add

ImmutableCollection<E> add(E first,
                           E second,
                           E... rest)

Create a new collection having the items of this collection plus new items.

Parameters:

first - The first item to add.

second - The second item to add.

rest - The other items to add.

Returns:

The new collection.

contains

boolean contains(E item)

Indicate if a given item is contained in this collection.

Parameters:

item - The item to search for.

Returns:

If this item was found in this collection.

See Also:

Collection.contains(Object)

toCollection

Collection<E> toCollection()

Create a read-only java util collection from this collection.

Returns:

The collection.

flatMap

<R> ImmutableCollection<R> flatMap(Function<E,Iterable<R>> mapper)

Flat map this collection.

Type Parameters:

R - The type returned by the mapper.

Parameters:

mapper - The mapping function.

Returns:

The iterable representing the mapped elements.

See Also:

Stream.flatMap(Function)

first

default E first()
         throws NoSuchElementException

Give the first item of this collection.

Returns:

The first item of this collection.

Throws:

NoSuchElementException - If this collection is empty.

isEmpty

default boolean isEmpty()

Indicate if this collection is empty.

Returns:

If this collection is empty.

isNotEmpty

default boolean isNotEmpty()

Indicate if this collection contains at least one item.

Returns:

If this collection contains any item.

addAll

ImmutableCollection<E> addAll(Collection<? extends E> items)

Create a new collection having the items of this collection plus items from another collection.

Parameters:

items - The items to add.

Returns:

The new collection.

addAll

default ImmutableCollection<E> addAll(ImmutableCollection<E> items)

Create a new collection having the items of this collection plus items from another collection.

Parameters:

items - The items to add.

Returns:

The new collection.

addAll

default ImmutableCollection<E> addAll(E[] items)

Create a new collection having the items of this collection plus items from an array.

Parameters:

items - The items to add.

Returns:

The new collection.

forEachUntil

default void forEachUntil(Predicate<E> loop)

Apply a function for each item of this collection until this function return false.

Parameters:

loop - The function to call with each item of this collection.

forEach

default void forEach(BiFunction<E,Integer,Boolean> loop)

Apply a function for each item of this collection until this function return false.

Parameters:

loop - The function to call with each item of this collection and its index.

reduce

default <R> R reduce(BiFunction<R,E,R> reducer,
                     R initialValue)

Apply a reducer to this collection.

Type Parameters:

R - The output type of the reducer.

Parameters:

reducer - The reducer.

initialValue - The initial value.

Returns:

The reduced value.

See Also:

Stream.reduce(Object, java.util.function.BinaryOperator)

some

default boolean some(Predicate<E> predicate)

Test if one of the items of this collection matches a given predicate.

Parameters:

predicate - The predicate to use.

Returns:

If one of the items of this collection matches the predicate.

every

default boolean every(Predicate<E> predicate)

Test if all the items of this collection match a given predicate.

Parameters:

predicate - The predicate to use.

Returns:

If all the items of this collection match the predicate.

find

default Optional<E> find(Predicate<E> predicate)

Find the first item that matches a given predicate.

Parameters:

predicate - The predicate with which to test this collection's items.

Returns:

The item in an optional. This optional will be empty if no item matched.

findIndex

default int findIndex(Predicate<E> predicate)

Find the number of iterations that were needed to find an item matching the given predicate.

Parameters:

predicate - The predicate with which to test this collection's items.

Returns:

The number of iterations, or -1 if no item matched the predicate.

doesNotContain

default boolean doesNotContain(E item)

Indicate if a given item is not contained in this collection.

Parameters:

item - The item to search for.

Returns:

If this item was not found in this collection.

See Also:

contains(Object)

toArray

E[] toArray(E[] a)

Copy the content of this collection in an array.

Parameters:

a - The array to attempt copy into.

Returns:

An array containing the items of this collection. Can be different than a if a was not large enough.

See Also:

Collection.toArray(Object[])

toArray

default E[] toArray(IntFunction<E[]> a)

Transforms this collection into an array.

Parameters:

a - The function that creates an array of the correct type given its size as input.

Returns:

The array containing the items in this collection.

getFirst

default <R> Optional<R> getFirst(Function<E,Optional<R>> optionalResult)

When all the items of this collection can produce an optional result via a method, returns the first non empty result.

Type Parameters:

R - The type of the value contained in the created Optional.

Parameters:

optionalResult - The function creating the optional result from an item in the collection. Will only be called while the current result is an empty optional.

Returns:

The optional with the first non empty result, or an empty optional if all results were empty.