Class AbstractQueue<T, Q extends AbstractQueue<T,Q>>

java.lang.Object

io.vavr.collection.AbstractQueue<T,Q>

All Implemented Interfaces:

Foldable<T>, Traversable<T>, Value<T>, Iterable<T>

Direct Known Subclasses:

PriorityQueue, Queue

abstract class AbstractQueue<T, Q extends AbstractQueue<T,Q>>
extends Object
implements Traversable<T>

Constructor Summary

Constructors

Constructor	Description
AbstractQueue()

Method Summary

Modifier and Type	Method	Description
Tuple2<T,Q>	dequeue()	Removes an element from this Queue.
Option<Tuple2<T,Q>>	dequeueOption()	Removes an element from this Queue.
Q	dropUntil(@NonNull Predicate<? super T> predicate)	Returns a new Traversable starting from the first element that satisfies the given predicate, dropping all preceding elements.
abstract Q	dropWhile(@NonNull Predicate<? super T> predicate)	Returns a new Traversable starting from the first element that does not satisfy the given predicate, dropping all preceding elements.
abstract Q	enqueue(T element)	Enqueues a new element.
Q	enqueue(T @NonNull ... elements)	Enqueues the given elements.
abstract Q	enqueueAll(Iterable<? extends T> elements)	Enqueues the given elements.
abstract Q	init()	Dual of tail(), returning all elements except the last.
Option<Q>	initOption()	Dual of tailOption(), returning all elements except the last as Option.
T	peek()	Returns the first element without modifying it.
Q	peek(@NonNull Consumer<? super T> action)	Performs the given action on the first element if this is an eager implementation.
Option<T>	peekOption()	Returns the first element without modifying the Queue.
Q	reject(@NonNull Predicate<? super T> predicate)	Returns a new traversable containing only the elements that do not satisfy the given predicate.
Q	removeAll(@NonNull Iterable<? extends T> elements)	Removes all occurrences of the specified elements from this Queue.
Q	removeAll(@NonNull Predicate<? super T> predicate)	Deprecated. Use reject(Predicate) instead
Q	retainAll(@NonNull Iterable<? extends T> elements)	Retains only the elements from this Traversable that are contained in the given elements.
abstract Q	tail()	Drops the first element of a non-empty Traversable.
Option<Q>	tailOption()	Returns a new Traversable without its first element as an Option.
abstract Q	takeUntil(@NonNull Predicate<? super T> predicate)	Takes elements from this Traversable until the given predicate holds for an element.
Q	takeWhile(@NonNull Predicate<? super T> predicate)	Takes elements from this Traversable while the given predicate holds.
String	toString()	Clarifies that values have a proper toString() method implemented.

Methods inherited from class Object

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

Methods inherited from interface Foldable

fold, reduce, reduceOption

Methods inherited from interface Traversable

arrangeBy, average, collect, containsAll, count, distinct, distinctBy, distinctBy, drop, dropRight, equals, existsUnique, filter, find, findLast, flatMap, foldLeft, foldRight, forEachWithIndex, get, groupBy, grouped, hasDefiniteSize, hashCode, head, headOption, isDistinct, isEmpty, isOrdered, isSequential, isSingleValued, isTraversableAgain, iterator, last, lastOption, length, map, mapTo, mapToVoid, max, maxBy, maxBy, min, minBy, minBy, mkCharSeq, mkCharSeq, mkCharSeq, mkString, mkString, mkString, nonEmpty, orElse, orElse, partition, product, reduceLeft, reduceLeftOption, reduceRight, reduceRightOption, replace, replaceAll, scan, scanLeft, scanRight, single, singleOption, size, slideBy, sliding, sliding, span, spliterator, sum, take, takeRight, unzip, unzip3, zip, zipAll, zipWith, zipWithIndex, zipWithIndex

Methods inherited from interface Value

collect, collect, contains, corresponds, eq, exists, forAll, forEach, getOrElse, getOrElse, getOrElseThrow, getOrElseTry, getOrNull, isAsync, isLazy, out, out, stderr, stdout, stringPrefix, toArray, toCharSeq, toCompletableFuture, toEither, toEither, toInvalid, toInvalid, toJavaArray, toJavaArray, toJavaArray, toJavaCollection, toJavaList, toJavaList, toJavaMap, toJavaMap, toJavaMap, toJavaOptional, toJavaParallelStream, toJavaSet, toJavaSet, toJavaStream, toLeft, toLeft, toLinkedMap, toLinkedMap, toLinkedSet, toList, toMap, toMap, toOption, toPriorityQueue, toPriorityQueue, toQueue, toRight, toRight, toSet, toSortedMap, toSortedMap, toSortedMap, toSortedMap, toSortedSet, toSortedSet, toStream, toTree, toTree, toTry, toTry, toValid, toValid, toValidation, toValidation, toVector

Constructor Details

AbstractQueue

AbstractQueue()

Method Details

dequeue

public Tuple2<T,Q> dequeue()

Removes an element from this Queue.

Returns:

a tuple containing the first element and the remaining elements of this Queue

Throws:

NoSuchElementException - if this Queue is empty

dequeueOption

public Option<Tuple2<T,Q>> dequeueOption()

Removes an element from this Queue.

Returns:

None if this Queue is empty, otherwise Some Tuple containing the first element and the remaining elements of this Queue

enqueue

public abstract Q enqueue(T element)

Enqueues a new element.

Parameters:

element - The new element

Returns:

a new Queue instance, containing the new element

enqueue

public Q enqueue(T @NonNull ... elements)

Enqueues the given elements. A queue has FIFO order, i.e. the first of the given elements is the first which will be retrieved.

Parameters:

elements - Elements, may be empty

Returns:

a new Queue instance, containing the new elements

Throws:

NullPointerException - if elements is null

enqueueAll

public abstract Q enqueueAll(Iterable<? extends T> elements)

Enqueues the given elements. A queue has FIFO order, i.e. the first of the given elements is the first which will be retrieved.

Parameters:

elements - An Iterable of elements, may be empty

Returns:

a new Queue instance, containing the new elements

Throws:

NullPointerException - if elements is null

peek

public T peek()

Returns the first element without modifying it.

Returns:

the first element

Throws:

NoSuchElementException - if this Queue is empty

peekOption

public Option<T> peekOption()

Returns the first element without modifying the Queue.

Returns:

None if this Queue is empty, otherwise a Some containing the first element

dropUntil

public Q dropUntil(@NonNull Predicate<? super T> predicate)

Description copied from interface: Traversable

Returns a new Traversable starting from the first element that satisfies the given predicate, dropping all preceding elements.

Specified by:

dropUntil in interface Traversable<T>

Parameters:

predicate - a condition tested on each element

Returns:

a new instance starting from the first element matching the predicate

dropWhile

public abstract Q dropWhile(@NonNull Predicate<? super T> predicate)

Description copied from interface: Traversable

Returns a new Traversable starting from the first element that does not satisfy the given predicate, dropping all preceding elements.

This is equivalent to dropUntil(predicate.negate()), which is useful for method references that cannot be negated directly.

Specified by:

dropWhile in interface Traversable<T>

Parameters:

predicate - a condition tested on each element

Returns:

a new instance starting from the first element not matching the predicate

init

public abstract Q init()

Dual of tail(), returning all elements except the last.

Specified by:

init in interface Traversable<T>

Returns:

a new instance containing all elements except the last.

Throws:

UnsupportedOperationException - if this is empty

initOption

public Option<Q> initOption()

Dual of tailOption(), returning all elements except the last as Option.

Specified by:

initOption in interface Traversable<T>

Returns:

Some(Q) or None if this is empty.

tail

public abstract Q tail()

Drops the first element of a non-empty Traversable.

Specified by:

tail in interface Traversable<T>

Returns:

A new instance of Traversable containing all elements except the first.

Throws:

UnsupportedOperationException - if this is empty

tailOption

public Option<Q> tailOption()

Description copied from interface: Traversable

Returns a new Traversable without its first element as an Option.

Specified by:

tailOption in interface Traversable<T>

Returns:

Some(traversable) if non-empty, otherwise None

retainAll

public Q retainAll(@NonNull Iterable<? extends T> elements)

Description copied from interface: Traversable

Retains only the elements from this Traversable that are contained in the given elements.

Specified by:

retainAll in interface Traversable<T>

Parameters:

elements - the elements to keep

Returns:

a new Traversable containing only the elements present in elements, in their original order

removeAll

public Q removeAll(@NonNull Iterable<? extends T> elements)

Removes all occurrences of the specified elements from this Queue.

Parameters:

elements - the elements to be removed

Returns:

a new Queue with all occurrences of the specified elements removed

Throws:

NullPointerException - if elements is null

removeAll

@Deprecated
public Q removeAll(@NonNull Predicate<? super T> predicate)

Deprecated.

Use reject(Predicate) instead

Removes all elements from this Queue that satisfy the given predicate.

Parameters:

predicate - the predicate used to test elements

Returns:

a new Queue with all elements that satisfy the predicate removed

Throws:

NullPointerException - if predicate is null

reject

public Q reject(@NonNull Predicate<? super T> predicate)

Description copied from interface: Traversable

Returns a new traversable containing only the elements that do not satisfy the given predicate.

This is equivalent to filter(predicate.negate()).

Specified by:

reject in interface Traversable<T>

Parameters:

predicate - the condition to test elements

Returns:

a traversable with elements not matching the predicate

takeWhile

public Q takeWhile(@NonNull Predicate<? super T> predicate)

Description copied from interface: Traversable

Takes elements from this Traversable while the given predicate holds.

Specified by:

takeWhile in interface Traversable<T>

Parameters:

predicate - a condition tested sequentially on the elements

Returns:

a new Traversable containing all elements up to (but not including) the first one that does not satisfy the predicate

takeUntil

public abstract Q takeUntil(@NonNull Predicate<? super T> predicate)

Description copied from interface: Traversable

Takes elements from this Traversable until the given predicate holds for an element.

Equivalent to takeWhile(predicate.negate()), but useful when using method references that cannot be negated directly.

Specified by:

takeUntil in interface Traversable<T>

Parameters:

predicate - a condition tested sequentially on the elements

Returns:

a new Traversable containing all elements before the first one that satisfies the predicate

peek

public Q peek(@NonNull Consumer<? super T> action)

Description copied from interface: Value

Performs the given action on the first element if this is an eager implementation. Performs the given action on all elements (the first immediately, successive deferred), if this is a lazy implementation.

Specified by:

peek in interface Traversable<T>

Specified by:

peek in interface Value<T>

Parameters:

action - The action that will be performed on the element(s).

Returns:

this instance

toString

public String toString()

Description copied from interface: Value

Clarifies that values have a proper toString() method implemented.

See Object.toString().

Specified by:

toString in interface Value<T>

Overrides:

toString in class Object

Returns:

A String representation of this object