net.covers1624.quack.collection

Class ColUtils

java.lang.Object

net.covers1624.quack.collection.ColUtils

public class ColUtils
extends java.lang.Object

Various Collection Utilities for Iterables and Arrays.

Created by covers1624 on 5/08/18.

Constructor Summary

Constructors

Constructor and Description
ColUtils()

Method Summary

Modifier and Type	Method and Description
static <T> java.util.List<T>	addAllNoNull(T[] array, java.util.List<T> list) Adds all elements from the array that are not null to the list.
static <T> T[]	addToArrayFirstNull(T[] array, T value) Adds the value at the first null index in the array.
static <T> boolean	allMatch(java.lang.Iterable<T> col, java.util.function.Predicate<T> func) Returns true if all elements in the provided Iterable match the given predicate.
static <T> boolean	allMatch(T[] col, java.util.function.Predicate<T> func) Returns true if all elements in the provided array match the given predicate.
static <T> boolean	anyMatch(java.lang.Iterable<T> col, java.util.function.Predicate<T> func) Returns true if any element in the provided Iterable matches the given predicate.
static void	arrayCopy(java.lang.Object src, int srcPos, java.lang.Object dst, int destPos, int length) Basically a wrapper for System.arraycopy with support for Copyable's
static <T> boolean	contains(T[] input, T element) Checks if an array contains any of the specified element.
static <T> boolean	containsKeys(java.util.Map<T,?> map, T... keys) Checks if a map contains all keys passed in.
static <T> int	count(T[] array, java.util.function.Function<T,java.lang.Boolean> check) Counts elements in the array that conform to the Function check.
static <T> int	countNonNull(T[] array) Counts the elements in the array that are not null.
static <T> T[]	createNewArray(T[] array) Create a new array using the provided array as a template for both type and length.
static <T> T[]	createNewArray(T[] array, int length) Create a new array using the provided array as a template for the type and with the provided length.
static <T> T[]	fill(T[] array, T value) Fills the array with the specified value.
static <T> void	fillArray(T[] array, T value, java.util.function.Function<T,java.lang.Boolean> check) Fills the array with the specified value.
static <T> java.util.Optional<T>	findFirst(java.lang.Iterable<T> col, java.util.function.Predicate<T> func) Finds the first element in the Iterable that matches the given predicate.
static <T> T	head(java.lang.Iterable<T> col) Asserts the Iterable is not empty and returns the first element.
static <T> java.util.Optional<T>	headOption(java.lang.Iterable<T> col) Attempts to get the first element of the Iterable.
static <T> T	headOrDefault(java.lang.Iterable<T> col) Returns the first element in the Iterable otherwise null.
static <T> T	headOrDefault(java.lang.Iterable<T> col, T _default) Returns the first element in the Iterable otherwise the supplied default.
static <T> int	indexOf(T[] array, T object) Returns the index of the first occurrence of the specified element in the array.
static <T> int	indexOfRef(T[] array, T object) Returns the index of the first occurrence of the specified element in the array with the same identity.
static <T> T[]	inverse(T[] input, T[] allElements) Creates the inverse of an array.
static <T> boolean	isEmpty(T[] array) Checks if the array is all null.
static <T> boolean	isNullOrContainsNull(T[] input) Checks if the specified array is empty or contains a null entry.
static <E> java.lang.Iterable<E>	iterable(java.util.Enumeration<E> enumeration) Represents this Enumeration as an Iterable.
static <E> java.lang.Iterable<E>	iterable(java.util.stream.Stream<E> stream) Deprecated.
static <T> java.util.Iterator<T>	iterator(T[] arr) Return an iterator for an array.
static <T> java.util.Iterator<T>	iterator(T[] arr, int from, int until) Return an iterator for an array slice.
static <T> T	maxBy(java.lang.Iterable<T> col, java.util.function.ToIntFunction<T> func) Deprecated.
static <T> T	maxBy(T[] col, java.util.function.ToIntFunction<T> func) Returns the element in the array with the highest value returned by the supplied function.
static <T> T	maxByOrDefault(java.lang.Iterable<T> col, java.util.function.ToIntFunction<T> func, T default_) Returns the element in the Iterable with the highest value returned by the supplied function.
static <T> T[]	newArray(java.lang.Class<T> arrayClass, int length) Creates a new array form its component class.
static <T> T	only(java.lang.Iterable<T> col) Assert the Iterable contains a single element, and return it.
static <T> T	only(java.util.stream.Stream<T> stream) Deprecated.
static <T> T	onlyOrDefault(java.lang.Iterable<T> iterable) Returns the first element found in the Iterable if it's the first and only element in the iterable, otherwise null is returned.
static <T> T	onlyOrDefault(java.lang.Iterable<T> iterable, T _default) Returns the first element found in the Iterable if it's the first and only element in the iterable, otherwise the default value is returned.
static <T> T	onlyOrDefault(java.util.stream.Stream<T> stream) Deprecated.
static <T> T	onlyOrDefault(java.util.stream.Stream<T> stream, T _default) Deprecated.
static <E> java.util.stream.Stream<E>	parallelStream(java.lang.Iterable<E> iter) Deprecated.
static <T> T	requireMaxBy(java.lang.Iterable<T> col, java.util.function.ToIntFunction<T> func) Returns the element in the Iterable with the highest value returned by the supplied function.
static <T> void	reverse(T[] array) Reverse the provided array.
static <T> T[]	rollArray(T[] input, int shift) Rolls the array based on the shift.
static <T> T[]	slice(T[] arr, int from, int until) Slices the given array.
static <E> java.util.stream.Stream<E>	stream(java.lang.Iterable<E> iter) Deprecated.
static <T> T	tail(java.lang.Iterable<T> col) Asserts the Iterable is not empty and returns the last element.
static <T> java.util.Optional<T>	tailOption(java.lang.Iterable<T> col) Attempts to get the last element of the Iterable.
static <T> T	tailOrDefault(java.lang.Iterable<T> col) Returns the last element in the Iterable otherwise null.
static <T> T	tailOrDefault(java.lang.Iterable<T> col, T _default) Returns the last element in the Iterable otherwise the supplied default.
static java.util.List<java.lang.Integer>	toList(int[] arr) Convert an int array to a list of Integers.

Methods inherited from class java.lang.Object

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

Constructor Detail

ColUtils

public ColUtils()

Method Detail

slice

public static <T> T[] slice(T[] arr,
                            int from,
                            int until)

Slices the given array.

Parameters:

arr - The Array to slice.

from - The from index.

until - The until index.

Returns:

The sliced array.

maxBy

public static <T> T maxBy(T[] col,
                          java.util.function.ToIntFunction<T> func)

Returns the element in the array with the highest value returned by the supplied function.

Parameters:

col - The array.

func - The function.

Returns:

The max element or null.

maxBy

@Deprecated
public static <T> T maxBy(java.lang.Iterable<T> col,
                                      java.util.function.ToIntFunction<T> func)

Deprecated.

Returns the element in the Iterable with the highest value returned by the supplied function.

Parameters:

col - The array.

func - The function.

Returns:

The max element or null.

requireMaxBy

public static <T> T requireMaxBy(java.lang.Iterable<T> col,
                                 java.util.function.ToIntFunction<T> func)

Returns the element in the Iterable with the highest value returned by the supplied function.

Parameters:

col - The collection.

func - The function.

Returns:

The max element.

maxByOrDefault

public static <T> T maxByOrDefault(java.lang.Iterable<T> col,
                                   java.util.function.ToIntFunction<T> func,
                                   T default_)

Returns the element in the Iterable with the highest value returned by the supplied function.

Parameters:

col - The collection.

func - The function.

default_ - The default value to return if the collection is empty.

Returns:

The max element or the default value.

allMatch

public static <T> boolean allMatch(T[] col,
                                   java.util.function.Predicate<T> func)

Returns true if all elements in the provided array match the given predicate.

Parameters:

col - The collection to match.

func - The function to apply.

Returns:

If all elements match.

allMatch

public static <T> boolean allMatch(java.lang.Iterable<T> col,
                                   java.util.function.Predicate<T> func)

Returns true if all elements in the provided Iterable match the given predicate.

Parameters:

col - The collection to match.

func - The function to apply.

Returns:

If all elements match.

anyMatch

public static <T> boolean anyMatch(java.lang.Iterable<T> col,
                                   java.util.function.Predicate<T> func)

Returns true if any element in the provided Iterable matches the given predicate.

Parameters:

col - The collection to match.

func - The function to apply.

Returns:

If any elements match.

findFirst

public static <T> java.util.Optional<T> findFirst(java.lang.Iterable<T> col,
                                                  java.util.function.Predicate<T> func)

Finds the first element in the Iterable that matches the given predicate.

Parameters:

col - The collection.

func - The predicate.

Returns:

The Optional result.

headOption

public static <T> java.util.Optional<T> headOption(java.lang.Iterable<T> col)

Attempts to get the first element of the Iterable.

Parameters:

col - The collection.

Returns:

The optional result.

head

public static <T> T head(java.lang.Iterable<T> col)

Asserts the Iterable is not empty and returns the first element.

Parameters:

col - The Iterable.

Returns:

The first element.

Throws:

java.lang.IllegalArgumentException - If the Iterable is empty.

headOrDefault

public static <T> T headOrDefault(java.lang.Iterable<T> col)

Returns the first element in the Iterable otherwise null.

Parameters:

col - The Iterable.

Returns:

The first element, or null.

headOrDefault

public static <T> T headOrDefault(java.lang.Iterable<T> col,
                                  T _default)

Returns the first element in the Iterable otherwise the supplied default.

Parameters:

col - The Iterable.

_default - The default if the Iterable is empty.

Returns:

The first element, or the default.

tailOption

public static <T> java.util.Optional<T> tailOption(java.lang.Iterable<T> col)

Attempts to get the last element of the Iterable.

Parameters:

col - The collection.

Returns:

The optional result.

tail

public static <T> T tail(java.lang.Iterable<T> col)

Asserts the Iterable is not empty and returns the last element.

Parameters:

col - The Iterable.

Returns:

The last element.

Throws:

java.lang.IllegalArgumentException - If the Iterable is empty.

tailOrDefault

public static <T> T tailOrDefault(java.lang.Iterable<T> col)

Returns the last element in the Iterable otherwise null.

Parameters:

col - The Iterable.

Returns:

The last element, or null.

tailOrDefault

public static <T> T tailOrDefault(java.lang.Iterable<T> col,
                                  T _default)

Returns the last element in the Iterable otherwise the supplied default.

Parameters:

col - The Iterable.

_default - The default if the Iterable is empty.

Returns:

The last element, or the default.

containsKeys

@SafeVarargs
public static <T> boolean containsKeys(java.util.Map<T,?> map,
                                                    T... keys)

Checks if a map contains all keys passed in.

Type Parameters:

T - The type of data in the map key.

Parameters:

map - Map to check.

keys - Keys that must exist.

Returns:

False if fail.

addToArrayFirstNull

public static <T> T[] addToArrayFirstNull(T[] array,
                                          T value)

Adds the value at the first null index in the array.

Type Parameters:

T - Type of value.

Parameters:

array - Array to add to.

value - Value to add.

Returns:

Returns a new array in the event the input was expanded.

addAllNoNull

public static <T> java.util.List<T> addAllNoNull(T[] array,
                                                 java.util.List<T> list)

Adds all elements from the array that are not null to the list.

Type Parameters:

T - What we are dealing with.

Parameters:

array - Array to grab from.

list - List to add to.

Returns:

The modified list.

isEmpty

public static <T> boolean isEmpty(T[] array)

Checks if the array is all null.

Type Parameters:

T - What we are dealing with.

Parameters:

array - The array to check.

Returns:

True if the array only contains nulls.

countNonNull

public static <T> int countNonNull(T[] array)

Counts the elements in the array that are not null.

Type Parameters:

T - What we are dealing with.

Parameters:

array - The array to check.

Returns:

The count of non-null objects in the array.

count

public static <T> int count(T[] array,
                            java.util.function.Function<T,java.lang.Boolean> check)

Counts elements in the array that conform to the Function check.

Type Parameters:

T - What we are dealing with.

Parameters:

array - The array to check.

check - The Function to apply to each element.

Returns:

The count.

fill

public static <T> T[] fill(T[] array,
                           T value)

Fills the array with the specified value. If the value is an instance of Copyable it will call copy.

Type Parameters:

T - What we are dealing with.

Parameters:

array - Array to fill.

value - Value to fill with.

fillArray

public static <T> void fillArray(T[] array,
                                 T value,
                                 java.util.function.Function<T,java.lang.Boolean> check)

Fills the array with the specified value. A Function is used to check if the value should be replaced. If the value is an instance of Copyable it will call copy.

Type Parameters:

T - What we are dealing with.

Parameters:

array - Array to fill.

value - Value to fill with.

check - Called to decide if the value should be replaced.

arrayCopy

public static void arrayCopy(java.lang.Object src,
                             int srcPos,
                             java.lang.Object dst,
                             int destPos,
                             int length)

Basically a wrapper for System.arraycopy with support for Copyable's

Parameters:

src - The source array.

srcPos - Starting position in the source array.

dst - The destination array.

destPos - Starting position in the destination array.

length - The number of elements to copy.

indexOf

public static <T> int indexOf(T[] array,
                              T object)

Returns the index of the first occurrence of the specified element in the array. Will return -1 if the element is non existent in the array.

Type Parameters:

T - What we are dealing with.

Parameters:

array - The array to search.

object - Element to find.

Returns:

The index in the array of the object.

indexOfRef

public static <T> int indexOfRef(T[] array,
                                 T object)

Returns the index of the first occurrence of the specified element in the array with the same identity. (Ref compare). Will return -1 if the element is non existent in the array.

Parameters:

array - The array to search.

object - Element to find.

Returns:

The index in the array of the object.

createNewArray

public static <T> T[] createNewArray(T[] array)

Create a new array using the provided array as a template for both type and length.

Type Parameters:

T - The type.

Parameters:

array - The template.

Returns:

The new array.

createNewArray

public static <T> T[] createNewArray(T[] array,
                                     int length)

Create a new array using the provided array as a template for the type and with the provided length.

Type Parameters:

T - The type.

Parameters:

array - The type template.

length - The new array's length.

Returns:

The new array.

newArray

public static <T> T[] newArray(java.lang.Class<T> arrayClass,
                               int length)

Creates a new array form its component class.

Type Parameters:

T - The thing.

Parameters:

arrayClass - The component class.

length - The length.

Returns:

The new array.

rollArray

public static <T> T[] rollArray(T[] input,
                                int shift)

Rolls the array based on the shift. Positive shift means the array will roll to the right. Negative shift means the array will roll to the left.

Type Parameters:

T - The thing.

Parameters:

input - The input array.

shift - The shift amount.

Returns:

The new array.

contains

public static <T> boolean contains(T[] input,
                                   T element)

Checks if an array contains any of the specified element.

Type Parameters:

T - The thing.

Parameters:

input - The input

element - The thing to test against.

Returns:

If the element exists at all.

inverse

public static <T> T[] inverse(T[] input,
                              T[] allElements)

Creates the inverse of an array. If the input array does not contain an element from the allElements array, then it is added to the output.

Type Parameters:

T - The thing.

Parameters:

input - The input.

allElements - All possible values.

Returns:

The inverse array.

isNullOrContainsNull

public static <T> boolean isNullOrContainsNull(T[] input)

Checks if the specified array is empty or contains a null entry.

Type Parameters:

T - The thing.

Parameters:

input - The input.

Returns:

If the array is null or contains null.

toList

public static java.util.List<java.lang.Integer> toList(int[] arr)

Convert an int array to a list of Integers.

Parameters:

arr - in.

Returns:

out.

iterable

public static <E> java.lang.Iterable<E> iterable(java.util.Enumeration<E> enumeration)

Represents this Enumeration as an Iterable.

Parameters:

enumeration - The Enumeration.

Returns:

The Iterable.

iterable

@Deprecated
public static <E> java.lang.Iterable<E> iterable(java.util.stream.Stream<E> stream)

Deprecated.

Shorthand for converting a stream to an Iterable.

It is important to note, that a Stream can only be consumed once, and thus, the returned Iterable can only be consumed once.

Parameters:

stream - The Stream.

Returns:

The Iterable.

stream

@Deprecated
public static <E> java.util.stream.Stream<E> stream(java.lang.Iterable<E> iter)

Deprecated.

Shorthand util for streaming an Iterable.

Parameters:

iter - The iterable.

Returns:

The Stream.

parallelStream

@Deprecated
public static <E> java.util.stream.Stream<E> parallelStream(java.lang.Iterable<E> iter)

Deprecated.

Shorthand util for streaming an Iterable in parallel.

Parameters:

iter - The iterable.

Returns:

The Parallel Stream.

onlyOrDefault

@Deprecated
public static <T> T onlyOrDefault(java.util.stream.Stream<T> stream)

Deprecated.

onlyOrDefault

@Deprecated
public static <T> T onlyOrDefault(java.util.stream.Stream<T> stream,
                                              T _default)

Deprecated.

Returns the first element found in the Stream if it is the only element in the stream, otherwise the default value is returned.

Parameters:

stream - The stream.

_default - The default value, in the event the stream is empty, or has more than one element.

Returns:

The first element or the default.

onlyOrDefault

public static <T> T onlyOrDefault(java.lang.Iterable<T> iterable)

Returns the first element found in the Iterable if it's the first and only element in the iterable, otherwise null is returned.

Parameters:

iterable - The Iterable.

Returns:

The first and only element, or null

onlyOrDefault

public static <T> T onlyOrDefault(java.lang.Iterable<T> iterable,
                                  T _default)

Returns the first element found in the Iterable if it's the first and only element in the iterable, otherwise the default value is returned.

Parameters:

iterable - The Iterable.

_default - The default value, in the event the iterable is empty, or has more than one element.

Returns:

The first element or the default.

only

@Deprecated
public static <T> T only(java.util.stream.Stream<T> stream)

Deprecated.

Assert the stream contains a single element, and return it.

Parameters:

stream - The stream.

Returns:

The element.

Throws:

java.lang.IllegalArgumentException - If the Stream contains no or more than one element.

only

public static <T> T only(java.lang.Iterable<T> col)

Assert the Iterable contains a single element, and return it.

Parameters:

col - The iterable.

Returns:

The element.

Throws:

java.lang.IllegalArgumentException - If the Iterable contains no or more than one element.

iterator

public static <T> java.util.Iterator<T> iterator(T[] arr)

Return an iterator for an array.

Parameters:

arr - The array.

Returns:

The Iterator.

iterator

public static <T> java.util.Iterator<T> iterator(T[] arr,
                                                 int from,
                                                 int until)

Return an iterator for an array slice.

Parameters:

arr - The array to iterate.

from - The offset in the array.

until - The end offset in the array.

Returns:

The Iterator.

reverse

public static <T> void reverse(T[] array)

Reverse the provided array.

Parameters:

array - The array to reverse.