Module dk.cloudcreate.essentials.shared

Package dk.cloudcreate.essentials.shared.collections

Class Lists

java.lang.Object

dk.cloudcreate.essentials.shared.collections.Lists

public class Lists
extends Object

List utility methods

Constructor Summary

Constructors

Constructor	Description
Lists()

Method Summary

Modifier and Type	Method	Description
static <T> Optional<T>	first(List<T> list)	Get the first element in a list
static <T> Optional<T>	last(List<T> list)	Get the last element in a list
static <T> Stream<Pair<Integer,T>>	toIndexedStream(List<T> list)	Convert the list to an 0-based Indexed Stream consisting of Pair's, where each Pair consists of the 0-based Index (i.e.

Methods inherited from class java.lang.Object

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

Constructor Detail

Lists

public Lists()

Method Detail

toIndexedStream

public static <T> Stream<Pair<Integer,T>> toIndexedStream(List<T> list)

Convert the list to an 0-based Indexed Stream consisting of Pair's, where each Pair consists of the 0-based Index (i.e. the first index has value 0) and the corresponding List element at the given index: Pair<Index, List-element-at-the-given-index>

Example:
List.of("A", "B", "C") will return a Stream of:

• Pair(0, "A")
• Pair(1, "B")
• Pair(2, "C")

Type Parameters:

T - the type of list element

Parameters:

list - the list that's converted to an indexed stream

Returns:

the indexed list

first

public static <T> Optional<T> first(List<T> list)

Get the first element in a list

Type Parameters:

T - the type of elements in the list

Parameters:

list - the non-null list

Returns:

the first element wrapped in an Optional or Optional.empty() if the list is empty

last

public static <T> Optional<T> last(List<T> list)

Get the last element in a list

Type Parameters:

T - the type of elements in the list

Parameters:

list - the non-null list

Returns:

the last element wrapped in an Optional or Optional.empty() if the list is empty