de.caff.generics

Class BasicLoop<T extends BasicLoop.Item<T>>

java.lang.Object

de.caff.generics.BasicLoop<T>

All Implemented Interfaces:

Countable<T>, Sizeable, java.lang.Iterable<T>

Direct Known Subclasses:

Loop

public class BasicLoop<T extends BasicLoop.Item<T>>
extends java.lang.Object
implements Countable<T>

Wrapper around a double linked list which forms a loop.

This basic implementation allows to use user-defined double linked items based on BasicLoop.Item because it makes some algorithms easier to add behavior to the items themselves. For loop with items holding generic values see Loop.

This class is not thread-safe.

Since:

November 02, 2022

Author:

Rammi

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BasicLoop.Item<V extends BasicLoop.Item<V>> Base implementation of a double linked loop item.

Nested classes/interfaces inherited from interface de.caff.generics.Countable

Countable.Base<TT>

Field Summary

Fields inherited from interface de.caff.generics.Countable

EMPTY

Fields inherited from interface de.caff.generics.Sizeable

NULL

Constructor Summary

Constructors

Constructor and Description
BasicLoop() Create an empty loop.
BasicLoop(java.util.function.Function<? super V,Function3<T,BasicLoop<T>,T,T>> creatorCreator, V... elements) Create a loop from an array.
BasicLoop(java.lang.Iterable<V> elements, java.util.function.Function<? super V,Function3<T,BasicLoop<T>,T,T>> creatorCreator) Create a loop from an iterable.

Method Summary

Modifier and Type	Method and Description
T	add(Function3<T,BasicLoop<T>,T,T> creator) Add an item.
<V> void	addAll(java.lang.Iterable<V> elements, java.util.function.Function<? super V,Function3<T,BasicLoop<T>,T,T>> creatorCreator) Add all the elements to the loop.
void	clear() Clear this loop.
Countable<T>	closedItemView() View this loop's items as a countable which is "closed".
T	findFirst(java.util.function.Predicate<? super T> condition) Find the first item in this loop which fulfills a condition.
T	findLast(java.util.function.Predicate<? super T> condition) Find the first item in this loop which fulfills a condition.
T	getFirstItem() Get the first item in the loop.
T	getFirstItemOrNull() Get the first item in the loop, or null if the loop is empty.
T	getLastItem() Get the last item in the loop.
T	getLastItemOrNull() Get the last item in the loop, or null if the loop is empty.
boolean	isEmpty() Is this countable empty?
java.util.Iterator<T>	iterator() Get an iterator over the items of this loop.
void	removeSuccessiveDuplicates() Remove duplicate items which are neighbors.
void	removeSuccessiveDuplicates(java.util.function.BiPredicate<? super T,? super T> equality) Remove duplicate items which are neighbors.
void	rotate(int steps) Rotate through the loop so the first item is exchanged
boolean	rotateBackwardUntil(java.util.function.Predicate<? super T> condition) Rotate backward until a condition is fulfilled for the first item.
boolean	rotateForwardUntil(java.util.function.Predicate<? super T> condition) Rotate forward until a condition is fulfilled for the first item.
int	size() Get the size.
java.lang.String	toMultiLineString() Create a multi-line string from this loop.
java.lang.String	toString()
java.lang.String	toString(java.lang.String connect) Create a string containing all items, connect with the given connector string.

Methods inherited from class java.lang.Object

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

Methods inherited from interface de.caff.generics.Countable

addAllTo, addToArray, asBase, asCollection, combined, combined, containsEq, containsRef, downCast, empty, equal, equals, filtered, filteredToIndexable, filterToCountable, first, firstOrNull, foldLeft, forEachFragile, freeze, fromOptional, frozen, frozen, groupingBy, groupingBy, hasAll, hasAny, isSorted, isStrictlySorted, last, lastOrNull, mappingBy, mappingBy, optFirst, optional, optLast, orderedCombination, singleton, sorted, toArray, toArray, toList, toString, uniform, view, viewArray, viewArray, viewCollection, viewCollection, viewCollectionN, viewCollectionN, viewFragile

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

BasicLoop

public BasicLoop()

Create an empty loop.

BasicLoop

public BasicLoop(@NotNull
                 java.lang.Iterable<V> elements,
                 @NotNull
                 java.util.function.Function<? super V,Function3<T,BasicLoop<T>,T,T>> creatorCreator)

Create a loop from an iterable.

Type Parameters:

V - element type of the iterable

Parameters:

elements - elements to insert into this loop, in the given order

creatorCreator - function which maps the elements to an item creator

BasicLoop

@SafeVarargs
public BasicLoop(@NotNull
                              java.util.function.Function<? super V,Function3<T,BasicLoop<T>,T,T>> creatorCreator,
                              V... elements)

Create a loop from an array.

Type Parameters:

V - element type of the array

Parameters:

creatorCreator - function which maps the array elements to an item creator

elements - elements to add to this loop

Method Detail

getFirstItem

@NotNull
public T getFirstItem()

Get the first item in the loop.

Returns:

first item

Throws:

EmptyLoopError - when loop is empty

getFirstItemOrNull

@Nullable
public T getFirstItemOrNull()

Get the first item in the loop, or null if the loop is empty.

Returns:

first item, or null

getLastItem

@NotNull
public T getLastItem()

Get the last item in the loop.

Returns:

last item

Throws:

EmptyLoopError - when loop is empty

getLastItemOrNull

@Nullable
public T getLastItemOrNull()

Get the last item in the loop, or null if the loop is empty.

Returns:

last item, or null

rotate

public void rotate(int steps)

Rotate through the loop so the first item is exchanged

Parameters:

steps - steps to rotate,

rotateForwardUntil

public boolean rotateForwardUntil(@NotNull
                                  java.util.function.Predicate<? super T> condition)

Rotate forward until a condition is fulfilled for the first item. If the condition is true for the first value no rotation occurs.

Parameters:

condition - condition tested on value

Returns:

true if the condition is now fulfilled for the first value, false if not or if this loop is empty

rotateBackwardUntil

public boolean rotateBackwardUntil(@NotNull
                                   java.util.function.Predicate<? super T> condition)

Rotate backward until a condition is fulfilled for the first item. If the condition is true for the first value no rotation occurs.

Parameters:

condition - condition tested on value

Returns:

true if the condition is now fulfilled for the first value, false if not or if this loop is empty

findFirst

@Nullable
public T findFirst(@NotNull
                             java.util.function.Predicate<? super T> condition)

Find the first item in this loop which fulfills a condition.

Use BasicLoop.Item.findNext(Predicate) on the result to continue searching.

Parameters:

condition - condition to be checked

Returns:

item found or null if no item matches the condition

findLast

@Nullable
public T findLast(@NotNull
                            java.util.function.Predicate<? super T> condition)

Find the first item in this loop which fulfills a condition.

Use BasicLoop.Item.findPrevious(Predicate) on the result to continue searching.

Parameters:

condition - condition to be checked

Returns:

item found or null if no item matches the condition

add

@NotNull
public T add(@NotNull
                      Function3<T,BasicLoop<T>,T,T> creator)

Add an item.

Parameters:

creator - item creator, called with 2nd and 3rd arguments being null for the initial loop element

Returns:

added item

addAll

public <V> void addAll(@NotNull
                       java.lang.Iterable<V> elements,
                       @NotNull
                       java.util.function.Function<? super V,Function3<T,BasicLoop<T>,T,T>> creatorCreator)

Add all the elements to the loop. This will add the given elements in the given order into the loop before the first element.

Type Parameters:

V - incoming value type

Parameters:

elements - elements to add to this loop

creatorCreator - function which creates the loop element creators from the incoming elements

size

public int size()

Description copied from interface: Sizeable

Get the size. Size is never negative.

Specified by:

size in interface Sizeable

Returns:

the size of this object, usually the number of contained elements, must not be negative

isEmpty

public boolean isEmpty()

Description copied from interface: Countable

Is this countable empty? An empty countable does not contain any elements which means that Sizeable.size() will return 0.

This default implementation just checks for Sizeable.size() returning 0

Specified by:

isEmpty in interface Countable<T extends BasicLoop.Item<T>>

Returns:

true if this countable is empty, false otherwise. Because calculating the size might be expensive sometimes in these cases implementations should override this method if possible.

clear

public void clear()

Clear this loop.

iterator

@NotNull
public java.util.Iterator<T> iterator()

Get an iterator over the items of this loop.

Specified by:

iterator in interface java.lang.Iterable<T extends BasicLoop.Item<T>>

Returns:

item iterator

closedItemView

@NotNull
public Countable<T> closedItemView()

View this loop's items as a countable which is "closed". The returned countable will virtually close the loop by adding the first item of the loop again at the end. This simplifies some usages of the loop.

Returns:

closed item view of this loop

removeSuccessiveDuplicates

public void removeSuccessiveDuplicates(@NotNull
                                       java.util.function.BiPredicate<? super T,? super T> equality)

Remove duplicate items which are neighbors.

Parameters:

equality - equality check for items, expected to return true for duplicates

removeSuccessiveDuplicates

public void removeSuccessiveDuplicates()

Remove duplicate items which are neighbors. This method calls removeSuccessiveDuplicates(BiPredicate) with Objects.deepEquals(Object, Object) as equality check.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

toString

@NotNull
public java.lang.String toString(@NotNull
                                          java.lang.String connect)

Create a string containing all items, connect with the given connector string.

Parameters:

connect - connector string

Returns:

string representation of this loop, items separated by connect

toMultiLineString

@NotNull
public java.lang.String toMultiLineString()

Create a multi-line string from this loop.

Returns:

multi-line string