io.werval.util

Class Iterables

java.lang.Object

io.werval.util.Iterables

public final class Iterables
extends Object

Utilities to work with Iterables.

Method Summary

Modifier and Type	Method and Description
static <T,C extends Collection<T>> C	addAll(C collection, Iterable<? extends T> iterable) Add all items of an Iterable into a Collection.
static <T> Iterable<T>	asIterable(T... items) Create an Iterable of given items.
static long	count(Iterable<?> iterable) Count the number of items.
static <T> Iterable<T>	empty() Empty Iterable.
static <T> T	first(Iterable<T> iterable) First item or null.
static <I,O> Iterable<O>	map(Iterable<I> input, Function<I,O> function)
static <T,I extends Iterable<T>> I	notEmptyOrNull(I iterable)
static <T> Iterable<T>	skip(int skip, Iterable<T> iterable) Skip some items.
static <T> List<T>	toList(Iterable<T> iterable) Create a new List with all items of an Iterable.

Methods inherited from class java.lang.Object

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

Method Detail

empty

public static <T> Iterable<T> empty()

Empty Iterable.

Type Parameters:

T - Parameterized item type

Returns:

An empty Iterable

first

public static <T> T first(Iterable<T> iterable)

First item or null.

Type Parameters:

T - Parameterized item type

Parameters:

iterable - Iterable

Returns:

First item or null

count

public static long count(Iterable<?> iterable)

Count the number of items.

Parameters:

iterable - Iterable

Returns:

Number of items in the Iterable

skip

public static <T> Iterable<T> skip(int skip,
                                   Iterable<T> iterable)

Skip some items.

Type Parameters:

T - Parameterized item type

Parameters:

skip - How many items to skip

iterable - Iterable

Returns:

An Iterable starting after skipped items

map

public static <I,O> Iterable<O> map(Iterable<I> input,
                                    Function<I,O> function)

addAll

public static <T,C extends Collection<T>> C addAll(C collection,
                                                   Iterable<? extends T> iterable)

Add all items of an Iterable into a Collection.

Type Parameters:

T - Parameterized item type

C - Parameterized collection type

Parameters:

collection - Collection to add to

iterable - Items to add to the given collection

Returns:

Given collection

asIterable

public static <T> Iterable<T> asIterable(T... items)

Create an Iterable of given items.

Type Parameters:

T - Parameterized item type

Parameters:

items - Items to turn in an Iterable

Returns:

An Iterable of given items

toList

public static <T> List<T> toList(Iterable<T> iterable)

Create a new List with all items of an Iterable.

Type Parameters:

T - Parameterized item type

Parameters:

iterable - Iterable

Returns:

A new List with all items from the given Iterable

notEmptyOrNull

public static <T,I extends Iterable<T>> I notEmptyOrNull(I iterable)