revxrsal.commands.util

Class Collections

java.lang.Object

revxrsal.commands.util.Collections

public final class Collections
extends java.lang.Object

Provides utilities for dealing with collections and iterators. This provides similar functions to Streams without the intermediate layer of a Stream.

This improves performance and allows us to make use of invariants of data-backed collections (as a Stream is not necessarily backed by a data structure).

Method Summary

Modifier and Type	Method and Description
static <T> boolean	any(@NotNull java.lang.Iterable<T> iterator, java.util.function.Predicate<T> predicate)
static <T> @Unmodifiable @NotNull java.util.List<T>	copyList(@NotNull java.util.Collection<T> list)
static <K,V> @Unmodifiable @NotNull java.util.Map<K,V>	copyMap(@NotNull java.util.Map<K,V> map)
static <T> @NotNull java.util.List<T>	filter(@NotNull java.lang.Iterable<T> iterator, @NotNull java.util.function.Predicate<T> predicate)
static <T> T	first(@NotNull java.lang.Iterable<T> iterator, @NotNull java.util.function.Predicate<T> predicate)
static <T> T	getOrNull(java.util.List<T> list, int index) Returns an element at the given [index] or `null` if the [index] is out of bounds of this array.
static <T> T	getOrNull(T[] array, int index) Returns an element at the given [index] or `null` if the [index] is out of bounds of this array.
static <T> java.lang.Object[]	insertAtBeginning(T[] original, T item) Creates a grown copy of the given array, with the given element inserted at the beginning.
static <U,T> @NotNull java.util.List<T>	map(@NotNull java.lang.Iterable<U> iterator, @NotNull java.util.function.Function<U,T> fn)
static <L,K,V> java.util.Map<L,V>	mapKeys(java.util.Map<K,V> map, java.util.function.Function<K,L> remap) Applies a mapping function to a given map's keys, and returns a new map that contains the mapped keys to their values
static <U,T> @NotNull java.util.LinkedList<T>	mapToLinkedList(@NotNull java.lang.Iterable<U> iterator, @NotNull java.util.function.Function<U,T> fn)
static <E> @NotNull @UnmodifiableView java.util.Iterator<E>	unmodifiableIterator(@NotNull java.util.Iterator<E> iterator)

Methods inherited from class java.lang.Object

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

Method Detail

mapKeys

@Contract(pure=true)
 @CheckReturnValue
public static <L,K,V> java.util.Map<L,V> mapKeys(java.util.Map<K,V> map,
                                                                                         java.util.function.Function<K,L> remap)

Applies a mapping function to a given map's keys, and returns a new map that contains the mapped keys to their values

Type Parameters:

K - Old key type

L - New key type

V - Value type

Parameters:

map - Original map

remap - Remapping function

Returns:

The new remapped map

getOrNull

public static <T> T getOrNull(T[] array,
                              int index)

Returns an element at the given [index] or `null` if the [index] is out of bounds of this array.

getOrNull

public static <T> T getOrNull(java.util.List<T> list,
                              int index)

Returns an element at the given [index] or `null` if the [index] is out of bounds of this array.

insertAtBeginning

@Contract(pure=true,
          value="null, _ -> fail; _, _ -> new")
 @CheckReturnValue
public static <T> java.lang.Object[] insertAtBeginning(@NotNull
                                                                                                                                               T[] original,
                                                                                                                                               @Nullable
                                                                                                                                               T item)

Creates a grown copy of the given array, with the given element inserted at the beginning.

Note: The given array is not modified.

Type Parameters:

T - Array type

Parameters:

original - Original array

item - The item to insert

Returns:

A new array consisting of the new item + original elements

first

@NotNull
public static <T> T first(@NotNull
                                   @NotNull java.lang.Iterable<T> iterator,
                                   @NotNull
                                   @NotNull java.util.function.Predicate<T> predicate)

filter

@Contract(pure=true)
 @CheckReturnValue
 @NotNull
public static <T> @NotNull java.util.List<T> filter(@NotNull
                                                                                                      @NotNull java.lang.Iterable<T> iterator,
                                                                                                      @NotNull
                                                                                                      @NotNull java.util.function.Predicate<T> predicate)

map

@Contract(pure=true)
 @CheckReturnValue
 @NotNull
public static <U,T> @NotNull java.util.List<T> map(@NotNull
                                                                                                     @NotNull java.lang.Iterable<U> iterator,
                                                                                                     @NotNull
                                                                                                     @NotNull java.util.function.Function<U,T> fn)

any

public static <T> boolean any(@NotNull
                              @NotNull java.lang.Iterable<T> iterator,
                              java.util.function.Predicate<T> predicate)

mapToLinkedList

@NotNull
public static <U,T> @NotNull java.util.LinkedList<T> mapToLinkedList(@NotNull
                                                                              @NotNull java.lang.Iterable<U> iterator,
                                                                              @NotNull
                                                                              @NotNull java.util.function.Function<U,T> fn)

unmodifiableIterator

@NotNull
public static <E> @NotNull @UnmodifiableView java.util.Iterator<E> unmodifiableIterator(@NotNull
                                                                                                 @NotNull java.util.Iterator<E> iterator)

copyMap

@Contract(value="_ -> new")
 @CheckReturnValue
 @NotNull
public static <K,V> @Unmodifiable @NotNull java.util.Map<K,V> copyMap(@NotNull
                                                                                                                               @NotNull java.util.Map<K,V> map)

copyList

@Contract(value="_ -> new")
 @CheckReturnValue
 @NotNull
public static <T> @Unmodifiable @NotNull java.util.List<T> copyList(@NotNull
                                                                                                                             @NotNull java.util.Collection<T> list)