Class Queue<T>

  • Type Parameters:
    T - Component type of the Queue
    All Implemented Interfaces:
    Foldable<T>, LinearSeq<T>, Seq<T>, Traversable<T>, Function1<java.lang.Integer,​T>, Iterable<T>, PartialFunction<java.lang.Integer,​T>, Value<T>, java.io.Serializable, java.lang.Iterable<T>, java.util.function.Function<java.lang.Integer,​T>

    public final class Queue<T>
    extends java.lang.Object
    implements LinearSeq<T>
    An immutable Queue stores elements allowing a first-in-first-out (FIFO) retrieval.

    Queue API:

    A Queue internally consists of a front List containing the front elements of the Queue in the correct order and a rear List containing the rear elements of the Queue in reverse order.

    When the front list is empty, front and rear are swapped and rear is reversed. This implies the following queue invariant: front.isEmpty() => rear.isEmpty().

    See Okasaki, Chris: Purely Functional Data Structures (p. 42 ff.). Cambridge, 2003.

    See Also:
    Serialized Form
    • Method Summary

      Modifier and Type Method Description
      Queue<T> append​(T element)
      Appends an element to this.
      Queue<T> appendAll​(java.lang.Iterable<? extends T> elements)
      Appends all given elements to this.
      java.util.List<T> asJava()
      Creates an immutable List view on top of this Seq, i.e.
      Queue<T> asJava​(java.util.function.Consumer<? super java.util.List<T>> action)
      Creates an immutable List view on top of this Seq that is passed to the given action.
      java.util.List<T> asJavaMutable()
      Creates a mutable List view on top of this Seq, i.e.
      Queue<T> asJavaMutable​(java.util.function.Consumer<? super java.util.List<T>> action)
      Creates a mutable List view on top of this Seq that is passed to the given action.
      <R> Queue<R> collect​(PartialFunction<? super T,​? extends R> partialFunction)
      Collects all elements that are in the domain of the given partialFunction by mapping the elements to type R.
      static <T> java.util.stream.Collector<T,​java.util.ArrayList<T>,​Queue<T>> collector()
      Returns a Collector which may be used in conjunction with Stream.collect(java.util.stream.Collector) to obtain a Queue .
      Queue<Queue<T>> combinations()
      Returns the union of all combinations from k = 0 to length().
      Queue<Queue<T>> combinations​(int k)
      Returns the k-combination of this traversable, i.e.
      Iterator<Queue<T>> crossProduct​(int power)
      Calculates the n-ary cartesian power (or cross product or simply product) of this.
      Tuple2<T,​Q> dequeue()
      Removes an element from this Queue.
      Option<Tuple2<T,​Q>> dequeueOption()
      Removes an element from this Queue.
      Queue<T> distinct()
      Returns a new version of this which contains no duplicates.
      Queue<T> distinctBy​(java.util.Comparator<? super T> comparator)
      Returns a new version of this which contains no duplicates.
      <U> Queue<T> distinctBy​(java.util.function.Function<? super T,​? extends U> keyExtractor)
      Returns a new version of this which contains no duplicates.
      Queue<T> drop​(int n)
      Drops the first n elements of this or all elements, if this length < n.
      Queue<T> dropRight​(int n)
      Drops the last n elements of this or all elements, if this length < n.
      Queue<T> dropRightUntil​(java.util.function.Predicate<? super T> predicate)
      Drops elements until the predicate holds for the current element, starting from the end.
      Queue<T> dropRightWhile​(java.util.function.Predicate<? super T> predicate)
      Drops elements while the predicate holds for the current element, starting from the end.
      Q dropUntil​(java.util.function.Predicate<? super T> predicate)
      Drops elements until the predicate holds for the current element.
      Queue<T> dropWhile​(java.util.function.Predicate<? super T> predicate)
      Drops elements while the predicate holds for the current element.
      static <T> Queue<T> empty()
      Returns the empty Queue.
      Queue<T> enqueue​(T element)
      Enqueues a new element.
      Q enqueue​(T... elements)
      Enqueues the given elements.
      Queue<T> enqueueAll​(java.lang.Iterable<? extends T> elements)
      Enqueues the given elements.
      boolean equals​(java.lang.Object o)
      In Vavr there are four basic classes of collections: Seq (sequential elements) Set (distinct elements) Map (indexed elements) Multimap (indexed collections) Two collection instances of these classes are equal if and only if both collections belong to the same basic collection class (Seq, Set, Map or Multimap) contain the same elements have the same element order, if the collections are of type Seq Two Map/Multimap elements, resp.
      static <T> Queue<T> fill​(int n, java.util.function.Supplier<? extends T> s)
      Returns a Queue containing n values supplied by a given Supplier s.
      static <T> Queue<T> fill​(int n, T element)
      Returns a Queue containing n times the given element
      Queue<T> filter​(java.util.function.Predicate<? super T> predicate)
      Returns a new traversable consisting of all elements which satisfy the given predicate.
      Q filterNot​(java.util.function.Predicate<? super T> predicate)
      Returns a new traversable consisting of all elements which do not satisfy the given predicate.
      <U> Queue<U> flatMap​(java.util.function.Function<? super T,​? extends java.lang.Iterable<? extends U>> mapper)
      FlatMaps this Traversable.
      T get​(int index)
      Returns the element at the specified index.
      <C> Map<C,​Queue<T>> groupBy​(java.util.function.Function<? super T,​? extends C> classifier)
      Groups this elements by classifying the elements.
      Iterator<Queue<T>> grouped​(int size)
      Groups this Traversable into fixed size blocks.
      boolean hasDefiniteSize()
      Checks if this Traversable is known to have a finite size.
      int hashCode()
      Returns the hash code of this collection.
      T head()
      Returns the first element of a non-empty Traversable.
      int indexOf​(T element, int from)
      Returns the index of the first occurrence of the given element after or at some start index or -1 if this does not contain the given element.
      Queue<T> init()
      Dual of Traversable.tail(), returning all elements except the last.
      Option<Q> initOption()
      Dual of Traversable.tailOption(), returning all elements except the last as Option.
      Queue<T> insert​(int index, T element)
      Inserts the given element at the specified index.
      Queue<T> insertAll​(int index, java.lang.Iterable<? extends T> elements)
      Inserts the given elements at the specified index.
      Queue<T> intersperse​(T element)
      Inserts an element between all elements of this Traversable.
      boolean isAsync()
      A Queue is computed synchronously.
      boolean isEmpty()
      Checks if this Traversable is empty.
      boolean isLazy()
      A Queue is computed eagerly.
      boolean isTraversableAgain()
      Checks if this Traversable can be repeatedly traversed.
      T last()
      Dual of Traversable.head(), returning the last element.
      int lastIndexOf​(T element, int end)
      Returns the index of the last occurrence of the given element before or at a given end index or -1 if this does not contain the given element.
      Queue<T> leftPadTo​(int length, T element)
      A copy of this sequence with an element prepended until a given target length is reached.
      int length()
      Computes the number of elements of this Traversable.
      <U> Queue<U> map​(java.util.function.Function<? super T,​? extends U> mapper)
      Maps the elements of this Traversable to elements of a new type preserving their order, if any.
      static <T> Queue<T> narrow​(Queue<? extends T> queue)
      Narrows a widened Queue<? extends T> to Queue<T> by performing a type-safe cast.
      static <T> Queue<T> of​(T element)
      Returns a singleton Queue, i.e.
      static <T> Queue<T> of​(T... elements)
      Creates a Queue of the given elements.
      static Queue<java.lang.Boolean> ofAll​(boolean... elements)
      Creates a Queue from boolean values.
      static Queue<java.lang.Byte> ofAll​(byte... elements)
      Creates a Queue from byte values.
      static Queue<java.lang.Character> ofAll​(char... elements)
      Creates a Queue from char values.
      static Queue<java.lang.Double> ofAll​(double... elements)
      Creates a Queue from double values.
      static Queue<java.lang.Float> ofAll​(float... elements)
      Creates a Queue from float values.
      static Queue<java.lang.Integer> ofAll​(int... elements)
      Creates a Queue from int values.
      static Queue<java.lang.Long> ofAll​(long... elements)
      Creates a Queue from long values.
      static Queue<java.lang.Short> ofAll​(short... elements)
      Creates a Queue from short values.
      static <T> Queue<T> ofAll​(java.lang.Iterable<? extends T> elements)
      Creates a Queue of the given elements.
      static <T> Queue<T> ofAll​(java.util.stream.Stream<? extends T> javaStream)
      Creates a Queue that contains the elements of the given Stream.
      Queue<T> orElse​(java.lang.Iterable<? extends T> other)
      Returns this Traversable if it is nonempty, otherwise return the alternative.
      Queue<T> orElse​(java.util.function.Supplier<? extends java.lang.Iterable<? extends T>> supplier)
      Returns this Traversable if it is nonempty, otherwise return the result of evaluating supplier.
      Queue<T> padTo​(int length, T element)
      A copy of this sequence with an element appended until a given target length is reached.
      Tuple2<Queue<T>,​Queue<T>> partition​(java.util.function.Predicate<? super T> predicate)
      Creates a partition of this Traversable by splitting this elements in two in distinct traversables according to a predicate.
      Queue<T> patch​(int from, java.lang.Iterable<? extends T> that, int replaced)
      Produces a new list where a slice of elements in this list is replaced by another sequence.
      T peek()
      Returns the first element without modifying it.
      Q peek​(java.util.function.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.
      Queue<Queue<T>> permutations()
      Computes all unique permutations.
      Queue<T> prepend​(T element)
      Prepends an element to this.
      Queue<T> prependAll​(java.lang.Iterable<? extends T> elements)
      Prepends all given elements to this.
      static Queue<java.lang.Character> range​(char from, char toExclusive)  
      static Queue<java.lang.Integer> range​(int from, int toExclusive)
      Creates a Queue of int numbers starting from from, extending to toExclusive - 1.
      static Queue<java.lang.Long> range​(long from, long toExclusive)
      Creates a Queue of long numbers starting from from, extending to toExclusive - 1.
      static Queue<java.lang.Character> rangeBy​(char from, char toExclusive, int step)  
      static Queue<java.lang.Double> rangeBy​(double from, double toExclusive, double step)  
      static Queue<java.lang.Integer> rangeBy​(int from, int toExclusive, int step)
      Creates a Queue of int numbers starting from from, extending to toExclusive - 1, with step.
      static Queue<java.lang.Long> rangeBy​(long from, long toExclusive, long step)
      Creates a Queue of long numbers starting from from, extending to toExclusive - 1, with step.
      static Queue<java.lang.Character> rangeClosed​(char from, char toInclusive)  
      static Queue<java.lang.Integer> rangeClosed​(int from, int toInclusive)
      Creates a Queue of int numbers starting from from, extending to toInclusive.
      static Queue<java.lang.Long> rangeClosed​(long from, long toInclusive)
      Creates a Queue of long numbers starting from from, extending to toInclusive.
      static Queue<java.lang.Character> rangeClosedBy​(char from, char toInclusive, int step)  
      static Queue<java.lang.Double> rangeClosedBy​(double from, double toInclusive, double step)  
      static Queue<java.lang.Integer> rangeClosedBy​(int from, int toInclusive, int step)
      Creates a Queue of int numbers starting from from, extending to toInclusive, with step.
      static Queue<java.lang.Long> rangeClosedBy​(long from, long toInclusive, long step)
      Creates a Queue of long numbers starting from from, extending to toInclusive, with step.
      Q reject​(java.util.function.Predicate<? super T> predicate)
      Deprecated.
      Queue<T> remove​(T element)
      Removes the first occurrence of the given element.
      Q removeAll​(java.lang.Iterable<? extends T> elements)  
      Q removeAll​(java.util.function.Predicate<? super T> predicate)
      Deprecated.
      Queue<T> removeAll​(T element)
      Removes all occurrences of the given element.
      Queue<T> removeAt​(int index)
      Removes the element at the specified position in this sequence.
      Queue<T> removeFirst​(java.util.function.Predicate<T> predicate)
      Removes the first occurrence that satisfy predicate
      Queue<T> removeLast​(java.util.function.Predicate<T> predicate)
      Removes the last occurrence that satisfy predicate
      Queue<T> replace​(T currentElement, T newElement)
      Replaces the first occurrence (if exists) of the given currentElement with newElement.
      Queue<T> replaceAll​(T currentElement, T newElement)
      Replaces all occurrences of the given currentElement with newElement.
      Q retainAll​(java.lang.Iterable<? extends T> elements)
      Keeps all occurrences of the given elements from this.
      Queue<T> reverse()
      Reverses the order of elements.
      Queue<T> rotateLeft​(int n)
      Circular rotates the elements by the specified distance to the left direction.
      Queue<T> rotateRight​(int n)
      Circular rotates the elements by the specified distance to the right direction.
      Queue<T> scan​(T zero, java.util.function.BiFunction<? super T,​? super T,​? extends T> operation)
      Computes a prefix scan of the elements of the collection.
      <U> Queue<U> scanLeft​(U zero, java.util.function.BiFunction<? super U,​? super T,​? extends U> operation)
      Produces a collection containing cumulative results of applying the operator going left to right.
      <U> Queue<U> scanRight​(U zero, java.util.function.BiFunction<? super T,​? super U,​? extends U> operation)
      Produces a collection containing cumulative results of applying the operator going right to left.
      Queue<T> shuffle()
      Randomize the order of the elements in the current sequence.
      Queue<T> shuffle​(java.util.Random random)
      Randomize the order of the elements in the current sequence using the given source of randomness.
      Queue<T> slice​(int beginIndex, int endIndex)
      Returns a Seq that is a slice of this.
      Iterator<Queue<T>> slideBy​(java.util.function.Function<? super T,​?> classifier)
      Slides a non-overlapping window of a variable size over this Traversable.
      Iterator<Queue<T>> sliding​(int size)
      Slides a window of a specific size and step size 1 over this Traversable by calling Traversable.sliding(int, int).
      Iterator<Queue<T>> sliding​(int size, int step)
      Slides a window of a specific size and step size over this Traversable.
      <U> Queue<T> sortBy​(java.util.Comparator<? super U> comparator, java.util.function.Function<? super T,​? extends U> mapper)
      Sorts this elements by comparing the elements in a different domain, using the given mapper.
      <U extends java.lang.Comparable<? super U>>
      Queue<T>
      sortBy​(java.util.function.Function<? super T,​? extends U> mapper)
      Sorts this elements by comparing the elements in a different domain, using the given mapper.
      Queue<T> sorted()
      Sorts this elements according to their natural order.
      Queue<T> sorted​(java.util.Comparator<? super T> comparator)
      Sorts this elements according to the provided Comparator.
      Tuple2<Queue<T>,​Queue<T>> span​(java.util.function.Predicate<? super T> predicate)
      Returns a tuple where the first element is the longest prefix of elements that satisfy the given predicate and the second element is the remainder.
      Tuple2<Queue<T>,​Queue<T>> splitAt​(int n)
      Splits a Seq at the specified index.
      Tuple2<Queue<T>,​Queue<T>> splitAt​(java.util.function.Predicate<? super T> predicate)
      Splits a sequence at the first element which satisfies the Predicate, e.g.
      Tuple2<Queue<T>,​Queue<T>> splitAtInclusive​(java.util.function.Predicate<? super T> predicate)
      Splits a sequence at the first element which satisfies the Predicate, e.g.
      boolean startsWith​(java.lang.Iterable<? extends T> that, int offset)
      Tests whether this list contains the given sequence at a given index.
      java.lang.String stringPrefix()
      Returns the name of this Value type, which is used by toString().
      Queue<T> subSequence​(int beginIndex)
      Returns a Seq that is a subsequence of this.
      Queue<T> subSequence​(int beginIndex, int endIndex)
      Returns a Seq that is a subsequence of this.
      static <T> Queue<T> tabulate​(int n, java.util.function.Function<? super java.lang.Integer,​? extends T> f)
      Returns a Queue containing n values of a given Function f over a range of integer values from 0 to n - 1.
      Queue<T> tail()
      Drops the first element of a non-empty Traversable.
      Option<Q> tailOption()
      Drops the first element of a non-empty Traversable and returns an Option.
      Queue<T> take​(int n)
      Takes the first n elements of this or all elements, if this length < n.
      Queue<T> takeRight​(int n)
      Takes the last n elements of this or all elements, if this length < n.
      Queue<T> takeRightUntil​(java.util.function.Predicate<? super T> predicate)
      Takes elements until the predicate holds for the current element, starting from the end.
      Queue<T> takeRightWhile​(java.util.function.Predicate<? super T> predicate)
      Takes elements while the predicate holds for the current element, starting from the end.
      Queue<T> takeUntil​(java.util.function.Predicate<? super T> predicate)
      Takes elements until the predicate holds for the current element.
      Q takeWhile​(java.util.function.Predicate<? super T> predicate)
      Takes elements while the predicate holds for the current element.
      java.lang.String toString()
      Clarifies that values have a proper toString() method implemented.
      <U> U transform​(java.util.function.Function<? super Queue<T>,​? extends U> f)
      Transforms this Queue.
      static <T> Queue<Queue<T>> transpose​(Queue<Queue<T>> matrix)
      Transposes the rows and columns of a Queue matrix.
      static <T> Queue<T> unfold​(T seed, java.util.function.Function<? super T,​Option<Tuple2<? extends T,​? extends T>>> f)
      Creates a Queue from a seed value and a function.
      static <T,​U>
      Queue<U>
      unfoldLeft​(T seed, java.util.function.Function<? super T,​Option<Tuple2<? extends T,​? extends U>>> f)
      Creates a Queue from a seed value and a function.
      static <T,​U>
      Queue<U>
      unfoldRight​(T seed, java.util.function.Function<? super T,​Option<Tuple2<? extends U,​? extends T>>> f)
      Creates a Queue from a seed value and a function.
      <T1,​T2>
      Tuple2<Queue<T1>,​Queue<T2>>
      unzip​(java.util.function.Function<? super T,​Tuple2<? extends T1,​? extends T2>> unzipper)
      Unzips this elements by mapping this elements to pairs which are subsequently split into two distinct sets.
      <T1,​T2,​T3>
      Tuple3<Queue<T1>,​Queue<T2>,​Queue<T3>>
      unzip3​(java.util.function.Function<? super T,​Tuple3<? extends T1,​? extends T2,​? extends T3>> unzipper)
      Unzips this elements by mapping this elements to triples which are subsequently split into three distinct sets.
      Queue<T> update​(int index, java.util.function.Function<? super T,​? extends T> updater)
      Updates the given element at the specified index using the specified function.
      Queue<T> update​(int index, T element)
      Updates the given element at the specified index.
      <U> Queue<Tuple2<T,​U>> zip​(java.lang.Iterable<? extends U> that)
      Returns a traversable formed from this traversable and another Iterable collection by combining corresponding elements in pairs.
      <U> Queue<Tuple2<T,​U>> zipAll​(java.lang.Iterable<? extends U> that, T thisElem, U thatElem)
      Returns a traversable formed from this traversable and another Iterable by combining corresponding elements in pairs.
      <U,​R>
      Queue<R>
      zipWith​(java.lang.Iterable<? extends U> that, java.util.function.BiFunction<? super T,​? super U,​? extends R> mapper)
      Returns a traversable formed from this traversable and another Iterable collection by mapping elements.
      Queue<Tuple2<T,​java.lang.Integer>> zipWithIndex()
      Zips this traversable with its indices.
      <U> Queue<U> zipWithIndex​(java.util.function.BiFunction<? super T,​? super java.lang.Integer,​? extends U> mapper)
      Returns a traversable formed from this traversable and another Iterable collection by mapping elements.
      • Methods inherited from class java.lang.Object

        clone, finalize, getClass, notify, notifyAll, wait, wait, wait
      • Methods inherited from interface io.vavr.Iterable

        to
    • Method Detail

      • collector

        public static <T> java.util.stream.Collector<T,​java.util.ArrayList<T>,​Queue<T>> collector()
        Returns a Collector which may be used in conjunction with Stream.collect(java.util.stream.Collector) to obtain a Queue .
        Type Parameters:
        T - Component type of the Queue.
        Returns:
        A io.vavr.collection.Queue Collector.
      • empty

        public static <T> Queue<T> empty()
        Returns the empty Queue.
        Type Parameters:
        T - Component type
        Returns:
        The empty Queue.
      • narrow

        public static <T> Queue<T> narrow​(Queue<? extends T> queue)
        Narrows a widened Queue<? extends T> to Queue<T> by performing a type-safe cast. This is eligible because immutable/read-only collections are covariant.
        Type Parameters:
        T - Component type of the Queue.
        Parameters:
        queue - An Queue.
        Returns:
        the given queue instance as narrowed type Queue<T>.
      • of

        public static <T> Queue<T> of​(T element)
        Returns a singleton Queue, i.e. a Queue of one element.
        Type Parameters:
        T - The component type
        Parameters:
        element - An element.
        Returns:
        A new Queue instance containing the given element
      • of

        @SafeVarargs
        public static <T> Queue<T> of​(T... elements)
        Creates a Queue of the given elements.
        Type Parameters:
        T - Component type of the Queue.
        Parameters:
        elements - Zero or more elements.
        Returns:
        A queue containing the given elements in the same order.
        Throws:
        java.lang.NullPointerException - if elements is null
      • ofAll

        public static <T> Queue<T> ofAll​(java.lang.Iterable<? extends T> elements)
        Creates a Queue of the given elements.
        Type Parameters:
        T - Component type of the Queue.
        Parameters:
        elements - An Iterable of elements.
        Returns:
        A queue containing the given elements in the same order.
        Throws:
        java.lang.NullPointerException - if elements is null
      • ofAll

        public static <T> Queue<T> ofAll​(java.util.stream.Stream<? extends T> javaStream)
        Creates a Queue that contains the elements of the given Stream.
        Type Parameters:
        T - Component type of the Stream.
        Parameters:
        javaStream - A Stream
        Returns:
        A Queue containing the given elements in the same order.
      • ofAll

        public static Queue<java.lang.Boolean> ofAll​(boolean... elements)
        Creates a Queue from boolean values.
        Parameters:
        elements - boolean values
        Returns:
        A new Queue of Boolean values
        Throws:
        java.lang.NullPointerException - if elements is null
      • ofAll

        public static Queue<java.lang.Byte> ofAll​(byte... elements)
        Creates a Queue from byte values.
        Parameters:
        elements - byte values
        Returns:
        A new Queue of Byte values
        Throws:
        java.lang.NullPointerException - if elements is null
      • ofAll

        public static Queue<java.lang.Character> ofAll​(char... elements)
        Creates a Queue from char values.
        Parameters:
        elements - char values
        Returns:
        A new Queue of Character values
        Throws:
        java.lang.NullPointerException - if elements is null
      • ofAll

        public static Queue<java.lang.Double> ofAll​(double... elements)
        Creates a Queue from double values.
        Parameters:
        elements - double values
        Returns:
        A new Queue of Double values
        Throws:
        java.lang.NullPointerException - if elements is null
      • ofAll

        public static Queue<java.lang.Float> ofAll​(float... elements)
        Creates a Queue from float values.
        Parameters:
        elements - float values
        Returns:
        A new Queue of Float values
        Throws:
        java.lang.NullPointerException - if elements is null
      • ofAll

        public static Queue<java.lang.Integer> ofAll​(int... elements)
        Creates a Queue from int values.
        Parameters:
        elements - int values
        Returns:
        A new Queue of Integer values
        Throws:
        java.lang.NullPointerException - if elements is null
      • ofAll

        public static Queue<java.lang.Long> ofAll​(long... elements)
        Creates a Queue from long values.
        Parameters:
        elements - long values
        Returns:
        A new Queue of Long values
        Throws:
        java.lang.NullPointerException - if elements is null
      • ofAll

        public static Queue<java.lang.Short> ofAll​(short... elements)
        Creates a Queue from short values.
        Parameters:
        elements - short values
        Returns:
        A new Queue of Short values
        Throws:
        java.lang.NullPointerException - if elements is null
      • tabulate

        public static <T> Queue<T> tabulate​(int n,
                                            java.util.function.Function<? super java.lang.Integer,​? extends T> f)
        Returns a Queue containing n values of a given Function f over a range of integer values from 0 to n - 1.
        Type Parameters:
        T - Component type of the Queue
        Parameters:
        n - The number of elements in the Queue
        f - The Function computing element values
        Returns:
        A Queue consisting of elements f(0),f(1), ..., f(n - 1)
        Throws:
        java.lang.NullPointerException - if f is null
      • fill

        public static <T> Queue<T> fill​(int n,
                                        java.util.function.Supplier<? extends T> s)
        Returns a Queue containing n values supplied by a given Supplier s.
        Type Parameters:
        T - Component type of the Queue
        Parameters:
        n - The number of elements in the Queue
        s - The Supplier computing element values
        Returns:
        An Queue of size n, where each element contains the result supplied by s.
        Throws:
        java.lang.NullPointerException - if s is null
      • fill

        public static <T> Queue<T> fill​(int n,
                                        T element)
        Returns a Queue containing n times the given element
        Type Parameters:
        T - Component type of the Queue
        Parameters:
        n - The number of elements in the Queue
        element - The element
        Returns:
        An Queue of size n, where each element is the given element.
      • range

        public static Queue<java.lang.Character> range​(char from,
                                                       char toExclusive)
      • rangeBy

        public static Queue<java.lang.Character> rangeBy​(char from,
                                                         char toExclusive,
                                                         int step)
      • rangeBy

        @GwtIncompatible
        public static Queue<java.lang.Double> rangeBy​(double from,
                                                      double toExclusive,
                                                      double step)
      • range

        public static Queue<java.lang.Integer> range​(int from,
                                                     int toExclusive)
        Creates a Queue of int numbers starting from from, extending to toExclusive - 1.

        Examples:

         
         Queue.range(0, 0)  // = Queue()
         Queue.range(2, 0)  // = Queue()
         Queue.range(-2, 2) // = Queue(-2, -1, 0, 1)
         
         
        Parameters:
        from - the first number
        toExclusive - the last number + 1
        Returns:
        a range of int values as specified or Nil if from >= toExclusive
      • rangeBy

        public static Queue<java.lang.Integer> rangeBy​(int from,
                                                       int toExclusive,
                                                       int step)
        Creates a Queue of int numbers starting from from, extending to toExclusive - 1, with step.

        Examples:

         
         Queue.rangeBy(1, 3, 1)  // = Queue(1, 2)
         Queue.rangeBy(1, 4, 2)  // = Queue(1, 3)
         Queue.rangeBy(4, 1, -2) // = Queue(4, 2)
         Queue.rangeBy(4, 1, 2)  // = Queue()
         
         
        Parameters:
        from - the first number
        toExclusive - the last number + 1
        step - the step
        Returns:
        a range of long values as specified or Nil if
        from >= toInclusive and step > 0 or
        from <= toInclusive and step < 0
        Throws:
        java.lang.IllegalArgumentException - if step is zero
      • range

        public static Queue<java.lang.Long> range​(long from,
                                                  long toExclusive)
        Creates a Queue of long numbers starting from from, extending to toExclusive - 1.

        Examples:

         
         Queue.range(0L, 0L)  // = Queue()
         Queue.range(2L, 0L)  // = Queue()
         Queue.range(-2L, 2L) // = Queue(-2L, -1L, 0L, 1L)
         
         
        Parameters:
        from - the first number
        toExclusive - the last number + 1
        Returns:
        a range of long values as specified or Nil if from >= toExclusive
      • rangeBy

        public static Queue<java.lang.Long> rangeBy​(long from,
                                                    long toExclusive,
                                                    long step)
        Creates a Queue of long numbers starting from from, extending to toExclusive - 1, with step.

        Examples:

         
         Queue.rangeBy(1L, 3L, 1L)  // = Queue(1L, 2L)
         Queue.rangeBy(1L, 4L, 2L)  // = Queue(1L, 3L)
         Queue.rangeBy(4L, 1L, -2L) // = Queue(4L, 2L)
         Queue.rangeBy(4L, 1L, 2L)  // = Queue()
         
         
        Parameters:
        from - the first number
        toExclusive - the last number + 1
        step - the step
        Returns:
        a range of long values as specified or Nil if
        from >= toInclusive and step > 0 or
        from <= toInclusive and step < 0
        Throws:
        java.lang.IllegalArgumentException - if step is zero
      • rangeClosed

        public static Queue<java.lang.Character> rangeClosed​(char from,
                                                             char toInclusive)
      • rangeClosedBy

        public static Queue<java.lang.Character> rangeClosedBy​(char from,
                                                               char toInclusive,
                                                               int step)
      • rangeClosedBy

        @GwtIncompatible
        public static Queue<java.lang.Double> rangeClosedBy​(double from,
                                                            double toInclusive,
                                                            double step)
      • rangeClosed

        public static Queue<java.lang.Integer> rangeClosed​(int from,
                                                           int toInclusive)
        Creates a Queue of int numbers starting from from, extending to toInclusive.

        Examples:

         
         Queue.rangeClosed(0, 0)  // = Queue(0)
         Queue.rangeClosed(2, 0)  // = Queue()
         Queue.rangeClosed(-2, 2) // = Queue(-2, -1, 0, 1, 2)
         
         
        Parameters:
        from - the first number
        toInclusive - the last number
        Returns:
        a range of int values as specified or Nil if from > toInclusive
      • rangeClosedBy

        public static Queue<java.lang.Integer> rangeClosedBy​(int from,
                                                             int toInclusive,
                                                             int step)
        Creates a Queue of int numbers starting from from, extending to toInclusive, with step.

        Examples:

         
         Queue.rangeClosedBy(1, 3, 1)  // = Queue(1, 2, 3)
         Queue.rangeClosedBy(1, 4, 2)  // = Queue(1, 3)
         Queue.rangeClosedBy(4, 1, -2) // = Queue(4, 2)
         Queue.rangeClosedBy(4, 1, 2)  // = Queue()
         
         
        Parameters:
        from - the first number
        toInclusive - the last number
        step - the step
        Returns:
        a range of int values as specified or Nil if
        from > toInclusive and step > 0 or
        from < toInclusive and step < 0
        Throws:
        java.lang.IllegalArgumentException - if step is zero
      • rangeClosed

        public static Queue<java.lang.Long> rangeClosed​(long from,
                                                        long toInclusive)
        Creates a Queue of long numbers starting from from, extending to toInclusive.

        Examples:

         
         Queue.rangeClosed(0L, 0L)  // = Queue(0L)
         Queue.rangeClosed(2L, 0L)  // = Queue()
         Queue.rangeClosed(-2L, 2L) // = Queue(-2L, -1L, 0L, 1L, 2L)
         
         
        Parameters:
        from - the first number
        toInclusive - the last number
        Returns:
        a range of long values as specified or Nil if from > toInclusive
      • transpose

        public static <T> Queue<Queue<T>> transpose​(Queue<Queue<T>> matrix)
        Transposes the rows and columns of a Queue matrix.
        Type Parameters:
        T - matrix element type
        Parameters:
        matrix - to be transposed.
        Returns:
        a transposed Queue matrix.
        Throws:
        java.lang.IllegalArgumentException - if the row lengths of matrix differ.

        ex: Queue.transpose(Queue(Queue(1,2,3), Queue(4,5,6))) → Queue(Queue(1,4), Queue(2,5), Queue(3,6))

      • rangeClosedBy

        public static Queue<java.lang.Long> rangeClosedBy​(long from,
                                                          long toInclusive,
                                                          long step)
        Creates a Queue of long numbers starting from from, extending to toInclusive, with step.

        Examples:

         
         Queue.rangeClosedBy(1L, 3L, 1L)  // = Queue(1L, 2L, 3L)
         Queue.rangeClosedBy(1L, 4L, 2L)  // = Queue(1L, 3L)
         Queue.rangeClosedBy(4L, 1L, -2L) // = Queue(4L, 2L)
         Queue.rangeClosedBy(4L, 1L, 2L)  // = Queue()
         
         
        Parameters:
        from - the first number
        toInclusive - the last number
        step - the step
        Returns:
        a range of int values as specified or Nil if
        from > toInclusive and step > 0 or
        from < toInclusive and step < 0
        Throws:
        java.lang.IllegalArgumentException - if step is zero
      • unfoldRight

        public static <T,​U> Queue<U> unfoldRight​(T seed,
                                                       java.util.function.Function<? super T,​Option<Tuple2<? extends U,​? extends T>>> f)
        Creates a Queue from a seed value and a function. The function takes the seed at first. The function should return None when it's done generating the Queue, otherwise Some Tuple of the element for the next call and the value to add to the resulting Queue.

        Example:

         
         Queue.unfoldRight(10, x -> x == 0
                     ? Option.none()
                     : Option.of(new Tuple2<>(x, x-1)));
         // Queue(10, 9, 8, 7, 6, 5, 4, 3, 2, 1))
         
         
        Type Parameters:
        T - type of seeds
        U - type of unfolded values
        Parameters:
        seed - the start value for the iteration
        f - the function to get the next step of the iteration
        Returns:
        a Queue with the values built up by the iteration
        Throws:
        java.lang.NullPointerException - if f is null
      • unfoldLeft

        public static <T,​U> Queue<U> unfoldLeft​(T seed,
                                                      java.util.function.Function<? super T,​Option<Tuple2<? extends T,​? extends U>>> f)
        Creates a Queue from a seed value and a function. The function takes the seed at first. The function should return None when it's done generating the Queue, otherwise Some Tuple of the value to add to the resulting Queue and the element for the next call.

        Example:

         
         Queue.unfoldLeft(10, x -> x == 0
                     ? Option.none()
                     : Option.of(new Tuple2<>(x-1, x)));
         // Queue(1, 2, 3, 4, 5, 6, 7, 8, 9, 10))
         
         
        Type Parameters:
        T - type of seeds
        U - type of unfolded values
        Parameters:
        seed - the start value for the iteration
        f - the function to get the next step of the iteration
        Returns:
        a Queue with the values built up by the iteration
        Throws:
        java.lang.NullPointerException - if f is null
      • unfold

        public static <T> Queue<T> unfold​(T seed,
                                          java.util.function.Function<? super T,​Option<Tuple2<? extends T,​? extends T>>> f)
        Creates a Queue from a seed value and a function. The function takes the seed at first. The function should return None when it's done generating the Queue, otherwise Some Tuple of the value to add to the resulting Queue and the element for the next call.

        Example:

         
         Queue.unfold(10, x -> x == 0
                     ? Option.none()
                     : Option.of(new Tuple2<>(x-1, x)));
         // Queue(1, 2, 3, 4, 5, 6, 7, 8, 9, 10))
         
         
        Type Parameters:
        T - type of seeds and unfolded values
        Parameters:
        seed - the start value for the iteration
        f - the function to get the next step of the iteration
        Returns:
        a Queue with the values built up by the iteration
        Throws:
        java.lang.NullPointerException - if f is null
      • enqueue

        public Queue<T> enqueue​(T element)
        Enqueues a new element.
        Parameters:
        element - The new element
        Returns:
        a new Queue instance, containing the new element
      • enqueueAll

        public Queue<T> enqueueAll​(java.lang.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:
        java.lang.NullPointerException - if elements is null
      • append

        public Queue<T> append​(T element)
        Description copied from interface: Seq
        Appends an element to this.
        Specified by:
        append in interface LinearSeq<T>
        Specified by:
        append in interface Seq<T>
        Parameters:
        element - An element
        Returns:
        A new Seq containing the given element appended to this elements
      • appendAll

        public Queue<T> appendAll​(java.lang.Iterable<? extends T> elements)
        Description copied from interface: Seq
        Appends all given elements to this.
        Specified by:
        appendAll in interface LinearSeq<T>
        Specified by:
        appendAll in interface Seq<T>
        Parameters:
        elements - An Iterable of elements
        Returns:
        A new Seq containing the given elements appended to this elements
      • asJava

        @GwtIncompatible
        public java.util.List<T> asJava()
        Description copied from interface: Seq
        Creates an immutable List view on top of this Seq, i.e. calling mutators will result in UnsupportedOperationException at runtime.

        The difference to conversion methods toJava*() is that

        • A view is created in O(1) (constant time) whereas conversion takes O(n) (linear time), with n = collection size.
        • The operations on a view have the same performance characteristics than the underlying persistent Vavr collection whereas the performance characteristics of a converted collection are those of the Java standard collections.
        Please note that our immutable java.util.List view throws UnsupportedOperationException before checking method arguments. Java does handle this case inconsistently.
        Specified by:
        asJava in interface Seq<T>
        Returns:
        A new immutable Collection view on this Traversable.
      • asJava

        @GwtIncompatible
        public Queue<T> asJava​(java.util.function.Consumer<? super java.util.List<T>> action)
        Description copied from interface: Seq
        Creates an immutable List view on top of this Seq that is passed to the given action.
        Specified by:
        asJava in interface LinearSeq<T>
        Specified by:
        asJava in interface Seq<T>
        Parameters:
        action - A side-effecting unit of work that operates on an immutable java.util.List view.
        Returns:
        this instance
        See Also:
        Seq.asJava()
      • asJavaMutable

        @GwtIncompatible
        public java.util.List<T> asJavaMutable()
        Description copied from interface: Seq
        Creates a mutable List view on top of this Seq, i.e. all mutator methods of the List are implemented.
        Specified by:
        asJavaMutable in interface Seq<T>
        Returns:
        A new mutable Collection view on this Traversable.
        See Also:
        Seq.asJava()
      • asJavaMutable

        @GwtIncompatible
        public Queue<T> asJavaMutable​(java.util.function.Consumer<? super java.util.List<T>> action)
        Description copied from interface: Seq
        Creates a mutable List view on top of this Seq that is passed to the given action.
        Specified by:
        asJavaMutable in interface LinearSeq<T>
        Specified by:
        asJavaMutable in interface Seq<T>
        Parameters:
        action - A side-effecting unit of work that operates on a mutable java.util.List view.
        Returns:
        this instance, if only read operations are performed on the java.util.List view or a new instance of this type, if write operations are performed on the java.util.List view.
        See Also:
        Seq.asJavaMutable()
      • collect

        public <R> Queue<R> collect​(PartialFunction<? super T,​? extends R> partialFunction)
        Description copied from interface: Traversable
        Collects all elements that are in the domain of the given partialFunction by mapping the elements to type R.

        More specifically, for each of this elements in iteration order first it is checked

        
         partialFunction.isDefinedAt(element)
         
        If the elements makes it through that filter, the mapped instance is added to the result collection
        
         R newElement = partialFunction.apply(element)
         
        Note:If this Traversable is ordered (i.e. extends Ordered, the caller of collect has to ensure that the elements are comparable (i.e. extend Comparable).
        Specified by:
        collect in interface LinearSeq<T>
        Specified by:
        collect in interface Seq<T>
        Specified by:
        collect in interface Traversable<T>
        Type Parameters:
        R - The new element type
        Parameters:
        partialFunction - A function that is not necessarily defined of all elements of this traversable.
        Returns:
        A new Traversable instance containing elements of type R
      • combinations

        public Queue<Queue<T>> combinations()
        Description copied from interface: Seq
        Returns the union of all combinations from k = 0 to length().

        Examples:

         
         [].combinations() = [[]]
        
         [1,2,3].combinations() = [
           [],                  // k = 0
           [1], [2], [3],       // k = 1
           [1,2], [1,3], [2,3], // k = 2
           [1,2,3]              // k = 3
         ]
         
         
        Specified by:
        combinations in interface LinearSeq<T>
        Specified by:
        combinations in interface Seq<T>
        Returns:
        the combinations of this
      • combinations

        public Queue<Queue<T>> combinations​(int k)
        Description copied from interface: Seq
        Returns the k-combination of this traversable, i.e. all subset of this of k distinct elements.
        Specified by:
        combinations in interface LinearSeq<T>
        Specified by:
        combinations in interface Seq<T>
        Parameters:
        k - Size of subsets
        Returns:
        the k-combination of this elements
        See Also:
        Combination
      • crossProduct

        public Iterator<Queue<T>> crossProduct​(int power)
        Description copied from interface: Seq
        Calculates the n-ary cartesian power (or cross product or simply product) of this.

        Example:

         
         // = ((A,A), (A,B), (A,C), ..., (B,A), (B,B), ..., (Z,Y), (Z,Z))
         CharSeq.rangeClosed('A', 'Z').crossProduct(2);
         
         

        Cartesian power of negative value will return empty iterator.

        Example:

         
         // = ()
         CharSeq.rangeClosed('A', 'Z').crossProduct(-1);
         
         
        Specified by:
        crossProduct in interface LinearSeq<T>
        Specified by:
        crossProduct in interface Seq<T>
        Parameters:
        power - the number of cartesian multiplications
        Returns:
        A new Iterator representing the n-ary cartesian power of this
      • distinct

        public Queue<T> distinct()
        Description copied from interface: Traversable
        Returns a new version of this which contains no duplicates. Elements are compared using equals.
        Specified by:
        distinct in interface LinearSeq<T>
        Specified by:
        distinct in interface Seq<T>
        Specified by:
        distinct in interface Traversable<T>
        Returns:
        a new Traversable containing this elements without duplicates
      • distinctBy

        public Queue<T> distinctBy​(java.util.Comparator<? super T> comparator)
        Description copied from interface: Traversable
        Returns a new version of this which contains no duplicates. Elements are compared using the given comparator.
        Specified by:
        distinctBy in interface LinearSeq<T>
        Specified by:
        distinctBy in interface Seq<T>
        Specified by:
        distinctBy in interface Traversable<T>
        Parameters:
        comparator - A comparator
        Returns:
        a new Traversable containing this elements without duplicates
      • distinctBy

        public <U> Queue<T> distinctBy​(java.util.function.Function<? super T,​? extends U> keyExtractor)
        Description copied from interface: Traversable
        Returns a new version of this which contains no duplicates. Elements mapped to keys which are compared using equals.

        The elements of the result are determined in the order of their occurrence - first match wins.

        Specified by:
        distinctBy in interface LinearSeq<T>
        Specified by:
        distinctBy in interface Seq<T>
        Specified by:
        distinctBy in interface Traversable<T>
        Type Parameters:
        U - key type
        Parameters:
        keyExtractor - A key extractor
        Returns:
        a new Traversable containing this elements without duplicates
      • drop

        public Queue<T> drop​(int n)
        Description copied from interface: Traversable
        Drops the first n elements of this or all elements, if this length < n.
        Specified by:
        drop in interface LinearSeq<T>
        Specified by:
        drop in interface Seq<T>
        Specified by:
        drop in interface Traversable<T>
        Parameters:
        n - The number of elements to drop.
        Returns:
        a new instance consisting of all elements of this except the first n ones, or else the empty instance, if this has less than n elements.
      • dropWhile

        public Queue<T> dropWhile​(java.util.function.Predicate<? super T> predicate)
        Description copied from interface: Traversable
        Drops elements while the predicate holds for the current element.

        Note: This is essentially the same as dropUntil(predicate.negate()). It is intended to be used with method references, which cannot be negated directly.

        Specified by:
        dropWhile in interface LinearSeq<T>
        Specified by:
        dropWhile in interface Seq<T>
        Specified by:
        dropWhile in interface Traversable<T>
        Parameters:
        predicate - A condition tested subsequently for this elements.
        Returns:
        a new instance consisting of all elements starting from the first one which does not satisfy the given predicate.
      • dropRight

        public Queue<T> dropRight​(int n)
        Description copied from interface: Traversable
        Drops the last n elements of this or all elements, if this length < n.
        Specified by:
        dropRight in interface LinearSeq<T>
        Specified by:
        dropRight in interface Seq<T>
        Specified by:
        dropRight in interface Traversable<T>
        Parameters:
        n - The number of elements to drop.
        Returns:
        a new instance consisting of all elements of this except the last n ones, or else the empty instance, if this has less than n elements.
      • dropRightUntil

        public Queue<T> dropRightUntil​(java.util.function.Predicate<? super T> predicate)
        Description copied from interface: Seq
        Drops elements until the predicate holds for the current element, starting from the end.
        Specified by:
        dropRightUntil in interface LinearSeq<T>
        Specified by:
        dropRightUntil in interface Seq<T>
        Parameters:
        predicate - A condition tested subsequently for this elements, starting from the end.
        Returns:
        a new instance consisting of all elements until and including the last one which does satisfy the given predicate.
      • dropRightWhile

        public Queue<T> dropRightWhile​(java.util.function.Predicate<? super T> predicate)
        Description copied from interface: Seq
        Drops elements while the predicate holds for the current element, starting from the end.

        Note: This is essentially the same as dropRightUntil(predicate.negate()). It is intended to be used with method references, which cannot be negated directly.

        Specified by:
        dropRightWhile in interface LinearSeq<T>
        Specified by:
        dropRightWhile in interface Seq<T>
        Parameters:
        predicate - A condition tested subsequently for this elements, starting from the end.
        Returns:
        a new instance consisting of all elements until and including the last one which does not satisfy the given predicate.
      • filter

        public Queue<T> filter​(java.util.function.Predicate<? super T> predicate)
        Description copied from interface: Traversable
        Returns a new traversable consisting of all elements which satisfy the given predicate.
        Specified by:
        filter in interface LinearSeq<T>
        Specified by:
        filter in interface Seq<T>
        Specified by:
        filter in interface Traversable<T>
        Parameters:
        predicate - A predicate
        Returns:
        a new traversable
      • flatMap

        public <U> Queue<U> flatMap​(java.util.function.Function<? super T,​? extends java.lang.Iterable<? extends U>> mapper)
        Description copied from interface: Traversable
        FlatMaps this Traversable.
        Specified by:
        flatMap in interface LinearSeq<T>
        Specified by:
        flatMap in interface Seq<T>
        Specified by:
        flatMap in interface Traversable<T>
        Type Parameters:
        U - The resulting component type.
        Parameters:
        mapper - A mapper
        Returns:
        A new Traversable instance.
      • get

        public T get​(int index)
        Description copied from interface: Seq
        Returns the element at the specified index.
        Specified by:
        get in interface Seq<T>
        Parameters:
        index - an index
        Returns:
        the element at the given index
      • groupBy

        public <C> Map<C,​Queue<T>> groupBy​(java.util.function.Function<? super T,​? extends C> classifier)
        Description copied from interface: Traversable
        Groups this elements by classifying the elements.
        Specified by:
        groupBy in interface LinearSeq<T>
        Specified by:
        groupBy in interface Seq<T>
        Specified by:
        groupBy in interface Traversable<T>
        Type Parameters:
        C - classified class type
        Parameters:
        classifier - A function which classifies elements into classes
        Returns:
        A Map containing the grouped elements
        See Also:
        Traversable.arrangeBy(Function)
      • grouped

        public Iterator<Queue<T>> grouped​(int size)
        Description copied from interface: Traversable
        Groups this Traversable into fixed size blocks.

        Let length be the length of this Iterable. Then grouped is defined as follows:

        • If this.isEmpty(), the resulting Iterator is empty.
        • If size <= length, the resulting Iterator will contain length / size blocks of size size and maybe a non-empty block of size length % size, if there are remaining elements.
        • If size > length, the resulting Iterator will contain one block of size length.
        Examples:
         
         [].grouped(1) = []
         [].grouped(0) throws
         [].grouped(-1) throws
         [1,2,3,4].grouped(2) = [[1,2],[3,4]]
         [1,2,3,4,5].grouped(2) = [[1,2],[3,4],[5]]
         [1,2,3,4].grouped(5) = [[1,2,3,4]]
         
         
        Please note that grouped(int) is a special case of Traversable.sliding(int, int), i.e. grouped(size) is the same as sliding(size, size).
        Specified by:
        grouped in interface LinearSeq<T>
        Specified by:
        grouped in interface Seq<T>
        Specified by:
        grouped in interface Traversable<T>
        Parameters:
        size - a positive block size
        Returns:
        A new Iterator of grouped blocks of the given size
      • hasDefiniteSize

        public boolean hasDefiniteSize()
        Description copied from interface: Traversable
        Checks if this Traversable is known to have a finite size.

        This method should be implemented by classes only, i.e. not by interfaces.

        Specified by:
        hasDefiniteSize in interface Traversable<T>
        Returns:
        true, if this Traversable is known to have a finite size, false otherwise.
      • head

        public T head()
        Description copied from interface: Traversable
        Returns the first element of a non-empty Traversable.
        Specified by:
        head in interface Traversable<T>
        Returns:
        The first element of this Traversable.
      • indexOf

        public int indexOf​(T element,
                           int from)
        Description copied from interface: Seq
        Returns the index of the first occurrence of the given element after or at some start index or -1 if this does not contain the given element.
        Specified by:
        indexOf in interface Seq<T>
        Parameters:
        element - an element
        from - start index
        Returns:
        the index of the first occurrence of the given element
      • insert

        public Queue<T> insert​(int index,
                               T element)
        Description copied from interface: Seq
        Inserts the given element at the specified index.
        Specified by:
        insert in interface LinearSeq<T>
        Specified by:
        insert in interface Seq<T>
        Parameters:
        index - an index
        element - an element
        Returns:
        a new Seq, where the given element is inserted into this at the given index
      • insertAll

        public Queue<T> insertAll​(int index,
                                  java.lang.Iterable<? extends T> elements)
        Description copied from interface: Seq
        Inserts the given elements at the specified index.
        Specified by:
        insertAll in interface LinearSeq<T>
        Specified by:
        insertAll in interface Seq<T>
        Parameters:
        index - an index
        elements - An Iterable of elements
        Returns:
        a new Seq, where the given elements are inserted into this at the given index
      • intersperse

        public Queue<T> intersperse​(T element)
        Description copied from interface: Seq
        Inserts an element between all elements of this Traversable.
        Specified by:
        intersperse in interface LinearSeq<T>
        Specified by:
        intersperse in interface Seq<T>
        Parameters:
        element - An element.
        Returns:
        an interspersed version of this
      • isAsync

        public boolean isAsync()
        A Queue is computed synchronously.
        Specified by:
        isAsync in interface Value<T>
        Returns:
        false
      • isEmpty

        public boolean isEmpty()
        Description copied from interface: Traversable
        Checks if this Traversable is empty.
        Specified by:
        isEmpty in interface Traversable<T>
        Specified by:
        isEmpty in interface Value<T>
        Returns:
        true, if this Traversable contains no elements, false otherwise.
      • isLazy

        public boolean isLazy()
        A Queue is computed eagerly.
        Specified by:
        isLazy in interface Value<T>
        Returns:
        false
      • isTraversableAgain

        public boolean isTraversableAgain()
        Description copied from interface: Traversable
        Checks if this Traversable can be repeatedly traversed.

        This method should be implemented by classes only, i.e. not by interfaces.

        Specified by:
        isTraversableAgain in interface Traversable<T>
        Returns:
        true, if this Traversable is known to be traversable repeatedly, false otherwise.
      • lastIndexOf

        public int lastIndexOf​(T element,
                               int end)
        Description copied from interface: Seq
        Returns the index of the last occurrence of the given element before or at a given end index or -1 if this does not contain the given element.
        Specified by:
        lastIndexOf in interface Seq<T>
        Parameters:
        element - an element
        end - the end index
        Returns:
        the index of the last occurrence of the given element
      • length

        public int length()
        Description copied from interface: Traversable
        Computes the number of elements of this Traversable.

        Same as Traversable.size().

        Specified by:
        length in interface Traversable<T>
        Returns:
        the number of elements
      • map

        public <U> Queue<U> map​(java.util.function.Function<? super T,​? extends U> mapper)
        Description copied from interface: Traversable
        Maps the elements of this Traversable to elements of a new type preserving their order, if any.
        Specified by:
        map in interface LinearSeq<T>
        Specified by:
        map in interface Seq<T>
        Specified by:
        map in interface Traversable<T>
        Specified by:
        map in interface Value<T>
        Type Parameters:
        U - Component type of the target Traversable
        Parameters:
        mapper - A mapper.
        Returns:
        a mapped Traversable
      • orElse

        public Queue<T> orElse​(java.lang.Iterable<? extends T> other)
        Description copied from interface: Traversable
        Returns this Traversable if it is nonempty, otherwise return the alternative.
        Specified by:
        orElse in interface LinearSeq<T>
        Specified by:
        orElse in interface Seq<T>
        Specified by:
        orElse in interface Traversable<T>
        Parameters:
        other - An alternative Traversable
        Returns:
        this Traversable if it is nonempty, otherwise return the alternative.
      • orElse

        public Queue<T> orElse​(java.util.function.Supplier<? extends java.lang.Iterable<? extends T>> supplier)
        Description copied from interface: Traversable
        Returns this Traversable if it is nonempty, otherwise return the result of evaluating supplier.
        Specified by:
        orElse in interface LinearSeq<T>
        Specified by:
        orElse in interface Seq<T>
        Specified by:
        orElse in interface Traversable<T>
        Parameters:
        supplier - An alternative Traversable supplier
        Returns:
        this Traversable if it is nonempty, otherwise return the result of evaluating supplier.
      • padTo

        public Queue<T> padTo​(int length,
                              T element)
        Description copied from interface: Seq
        A copy of this sequence with an element appended until a given target length is reached.

        Note: lazily-evaluated Seq implementations need to process all elements in order to gather the overall length.

        Specified by:
        padTo in interface LinearSeq<T>
        Specified by:
        padTo in interface Seq<T>
        Parameters:
        length - the target length
        element - the padding element
        Returns:
        a new sequence consisting of all elements of this sequence followed by the minimal number of occurrences of element so that the resulting sequence has a length of at least length.
      • leftPadTo

        public Queue<T> leftPadTo​(int length,
                                  T element)
        Description copied from interface: Seq
        A copy of this sequence with an element prepended until a given target length is reached.

        Note: lazily-evaluated Seq implementations need to process all elements in order to gather the overall length.

        Specified by:
        leftPadTo in interface Seq<T>
        Parameters:
        length - the target length
        element - the padding element
        Returns:
        a new sequence consisting of all elements of this sequence prepended by the minimal number of occurrences of element so that the resulting sequence has a length of at least length.
      • patch

        public Queue<T> patch​(int from,
                              java.lang.Iterable<? extends T> that,
                              int replaced)
        Description copied from interface: Seq
        Produces a new list where a slice of elements in this list is replaced by another sequence.
        Specified by:
        patch in interface LinearSeq<T>
        Specified by:
        patch in interface Seq<T>
        Parameters:
        from - the index of the first replaced element
        that - sequence for replacement
        replaced - the number of elements to drop in the original list
        Returns:
        a new sequence.
      • partition

        public Tuple2<Queue<T>,​Queue<T>> partition​(java.util.function.Predicate<? super T> predicate)
        Description copied from interface: Traversable
        Creates a partition of this Traversable by splitting this elements in two in distinct traversables according to a predicate.
        Specified by:
        partition in interface LinearSeq<T>
        Specified by:
        partition in interface Seq<T>
        Specified by:
        partition in interface Traversable<T>
        Parameters:
        predicate - A predicate which classifies an element if it is in the first or the second traversable.
        Returns:
        A disjoint union of two traversables. The first Traversable contains all elements that satisfy the given predicate, the second Traversable contains all elements that don't. The original order of elements is preserved.
      • permutations

        public Queue<Queue<T>> permutations()
        Description copied from interface: Seq
        Computes all unique permutations.

        Example:

         
         [].permutations() = []
        
         [1,2,3].permutations() = [
           [1,2,3],
           [1,3,2],
           [2,1,3],
           [2,3,1],
           [3,1,2],
           [3,2,1]
         ]
         
         
        Specified by:
        permutations in interface LinearSeq<T>
        Specified by:
        permutations in interface Seq<T>
        Returns:
        this unique permutations
      • prepend

        public Queue<T> prepend​(T element)
        Description copied from interface: Seq
        Prepends an element to this.
        Specified by:
        prepend in interface LinearSeq<T>
        Specified by:
        prepend in interface Seq<T>
        Parameters:
        element - An element
        Returns:
        A new Seq containing the given element prepended to this elements
      • prependAll

        public Queue<T> prependAll​(java.lang.Iterable<? extends T> elements)
        Description copied from interface: Seq
        Prepends all given elements to this.
        Specified by:
        prependAll in interface LinearSeq<T>
        Specified by:
        prependAll in interface Seq<T>
        Parameters:
        elements - An Iterable of elements
        Returns:
        A new Seq containing the given elements prepended to this elements
      • remove

        public Queue<T> remove​(T element)
        Description copied from interface: Seq
        Removes the first occurrence of the given element.
        Specified by:
        remove in interface LinearSeq<T>
        Specified by:
        remove in interface Seq<T>
        Parameters:
        element - An element to be removed from this Seq.
        Returns:
        a Seq containing all elements of this without the first occurrence of the given element.
      • removeFirst

        public Queue<T> removeFirst​(java.util.function.Predicate<T> predicate)
        Description copied from interface: Seq
        Removes the first occurrence that satisfy predicate
        Specified by:
        removeFirst in interface LinearSeq<T>
        Specified by:
        removeFirst in interface Seq<T>
        Parameters:
        predicate - an predicate
        Returns:
        a new Seq
      • removeLast

        public Queue<T> removeLast​(java.util.function.Predicate<T> predicate)
        Description copied from interface: Seq
        Removes the last occurrence that satisfy predicate
        Specified by:
        removeLast in interface LinearSeq<T>
        Specified by:
        removeLast in interface Seq<T>
        Parameters:
        predicate - an predicate
        Returns:
        a new Seq
      • removeAt

        public Queue<T> removeAt​(int index)
        Description copied from interface: Seq
        Removes the element at the specified position in this sequence. Shifts any subsequent elements to the left (subtracts one from their indices).
        Specified by:
        removeAt in interface LinearSeq<T>
        Specified by:
        removeAt in interface Seq<T>
        Parameters:
        index - position of element to remove
        Returns:
        a sequence containing all elements of this without the element at the specified position.
      • removeAll

        public Queue<T> removeAll​(T element)
        Description copied from interface: Seq
        Removes all occurrences of the given element.
        Specified by:
        removeAll in interface LinearSeq<T>
        Specified by:
        removeAll in interface Seq<T>
        Parameters:
        element - An element to be removed from this Seq.
        Returns:
        a Seq containing all elements of this but not the given element.
      • replace

        public Queue<T> replace​(T currentElement,
                                T newElement)
        Description copied from interface: Traversable
        Replaces the first occurrence (if exists) of the given currentElement with newElement.
        Specified by:
        replace in interface LinearSeq<T>
        Specified by:
        replace in interface Seq<T>
        Specified by:
        replace in interface Traversable<T>
        Parameters:
        currentElement - An element to be substituted.
        newElement - A replacement for currentElement.
        Returns:
        a Traversable containing all elements of this where the first occurrence of currentElement is replaced with newElement.
      • replaceAll

        public Queue<T> replaceAll​(T currentElement,
                                   T newElement)
        Description copied from interface: Traversable
        Replaces all occurrences of the given currentElement with newElement.
        Specified by:
        replaceAll in interface LinearSeq<T>
        Specified by:
        replaceAll in interface Seq<T>
        Specified by:
        replaceAll in interface Traversable<T>
        Parameters:
        currentElement - An element to be substituted.
        newElement - A replacement for currentElement.
        Returns:
        a Traversable containing all elements of this where all occurrences of currentElement are replaced with newElement.
      • reverse

        public Queue<T> reverse()
        Description copied from interface: Seq
        Reverses the order of elements.
        Specified by:
        reverse in interface LinearSeq<T>
        Specified by:
        reverse in interface Seq<T>
        Returns:
        the reversed elements.
      • rotateLeft

        public Queue<T> rotateLeft​(int n)
        Description copied from interface: Seq
        Circular rotates the elements by the specified distance to the left direction.
        
         // = List(3, 4, 5, 1, 2)
         List.of(1, 2, 3, 4, 5).rotateLeft(2);
         
        Specified by:
        rotateLeft in interface LinearSeq<T>
        Specified by:
        rotateLeft in interface Seq<T>
        Parameters:
        n - distance of left rotation
        Returns:
        the rotated elements.
      • rotateRight

        public Queue<T> rotateRight​(int n)
        Description copied from interface: Seq
        Circular rotates the elements by the specified distance to the right direction.
        
         // = List(4, 5, 1, 2, 3)
         List.of(1, 2, 3, 4, 5).rotateRight(2);
         
        Specified by:
        rotateRight in interface LinearSeq<T>
        Specified by:
        rotateRight in interface Seq<T>
        Parameters:
        n - distance of right rotation
        Returns:
        the rotated elements.
      • scan

        public Queue<T> scan​(T zero,
                             java.util.function.BiFunction<? super T,​? super T,​? extends T> operation)
        Description copied from interface: Traversable
        Computes a prefix scan of the elements of the collection. Note: The neutral element z may be applied more than once.
        Specified by:
        scan in interface LinearSeq<T>
        Specified by:
        scan in interface Seq<T>
        Specified by:
        scan in interface Traversable<T>
        Parameters:
        zero - neutral element for the operator op
        operation - the associative operator for the scan
        Returns:
        a new traversable collection containing the prefix scan of the elements in this traversable collection
      • scanLeft

        public <U> Queue<U> scanLeft​(U zero,
                                     java.util.function.BiFunction<? super U,​? super T,​? extends U> operation)
        Description copied from interface: Traversable
        Produces a collection containing cumulative results of applying the operator going left to right. Note: will not terminate for infinite-sized collections. Note: might return different results for different runs, unless the underlying collection type is ordered.
        Specified by:
        scanLeft in interface LinearSeq<T>
        Specified by:
        scanLeft in interface Seq<T>
        Specified by:
        scanLeft in interface Traversable<T>
        Type Parameters:
        U - the type of the elements in the resulting collection
        Parameters:
        zero - the initial value
        operation - the binary operator applied to the intermediate result and the element
        Returns:
        collection with intermediate results
      • scanRight

        public <U> Queue<U> scanRight​(U zero,
                                      java.util.function.BiFunction<? super T,​? super U,​? extends U> operation)
        Description copied from interface: Traversable
        Produces a collection containing cumulative results of applying the operator going right to left. The head of the collection is the last cumulative result. Note: will not terminate for infinite-sized collections. Note: might return different results for different runs, unless the underlying collection type is ordered.
        Specified by:
        scanRight in interface LinearSeq<T>
        Specified by:
        scanRight in interface Seq<T>
        Specified by:
        scanRight in interface Traversable<T>
        Type Parameters:
        U - the type of the elements in the resulting collection
        Parameters:
        zero - the initial value
        operation - the binary operator applied to the intermediate result and the element
        Returns:
        collection with intermediate results
      • shuffle

        public Queue<T> shuffle()
        Description copied from interface: Seq
        Randomize the order of the elements in the current sequence.
        Specified by:
        shuffle in interface LinearSeq<T>
        Specified by:
        shuffle in interface Seq<T>
        Returns:
        a sequence with the same elements as the current sequence in a random order.
      • shuffle

        public Queue<T> shuffle​(java.util.Random random)
        Description copied from interface: Seq
        Randomize the order of the elements in the current sequence using the given source of randomness.
        Specified by:
        shuffle in interface LinearSeq<T>
        Specified by:
        shuffle in interface Seq<T>
        Parameters:
        random - A random number generator
        Returns:
        a sequence with the same elements as the current sequence in a random order.
      • slice

        public Queue<T> slice​(int beginIndex,
                              int endIndex)
        Description copied from interface: Seq
        Returns a Seq that is a slice of this. The slice begins with the element at the specified beginIndex and extends to the element at index endIndex - 1.

        Examples:

         
         List.of(1, 2, 3, 4).slice(1, 3); // = (2, 3)
         List.of(1, 2, 3, 4).slice(0, 4); // = (1, 2, 3, 4)
         List.of(1, 2, 3, 4).slice(2, 2); // = ()
         List.of(1, 2).slice(1, 0);       // = ()
         List.of(1, 2).slice(-10, 10);    // = (1, 2)
         
         
        See also Seq.subSequence(int, int) which throws in some cases instead of returning a sequence.
        Specified by:
        slice in interface LinearSeq<T>
        Specified by:
        slice in interface Seq<T>
        Parameters:
        beginIndex - the beginning index, inclusive
        endIndex - the end index, exclusive
        Returns:
        the specified slice
      • slideBy

        public Iterator<Queue<T>> slideBy​(java.util.function.Function<? super T,​?> classifier)
        Description copied from interface: Traversable
        Slides a non-overlapping window of a variable size over this Traversable.

        Each window contains elements with the same class, as determined by classifier. Two consecutive values in this Traversable will be in the same window only if classifier returns equal values for them. Otherwise, the values will constitute the last element of the previous window and the first element of the next window.

        Examples:

        
         [].slideBy(Function.identity()) = []
         [1,2,3,4,4,5].slideBy(Function.identity()) = [[1],[2],[3],[4,4],[5]]
         [1,2,3,10,12,5,7,20,29].slideBy(x -> x/10) = [[1,2,3],[10,12],[5,7],[20,29]]
         
        Specified by:
        slideBy in interface LinearSeq<T>
        Specified by:
        slideBy in interface Seq<T>
        Specified by:
        slideBy in interface Traversable<T>
        Parameters:
        classifier - A function which classifies elements into classes
        Returns:
        A new Iterator of windows of the grouped elements
      • sliding

        public Iterator<Queue<T>> sliding​(int size,
                                          int step)
        Description copied from interface: Traversable
        Slides a window of a specific size and step size over this Traversable.

        Examples:

         
         [].sliding(1,1) = []
         [1,2,3,4,5].sliding(2,3) = [[1,2],[4,5]]
         [1,2,3,4,5].sliding(2,4) = [[1,2],[5]]
         [1,2,3,4,5].sliding(2,5) = [[1,2]]
         [1,2,3,4].sliding(5,3) = [[1,2,3,4],[4]]
         
         
        Specified by:
        sliding in interface LinearSeq<T>
        Specified by:
        sliding in interface Seq<T>
        Specified by:
        sliding in interface Traversable<T>
        Parameters:
        size - a positive window size
        step - a positive step size
        Returns:
        a new Iterator of windows of a specific size using a specific step size
      • sorted

        public Queue<T> sorted()
        Description copied from interface: Seq
        Sorts this elements according to their natural order. If this elements are not Comparable, a java.lang.ClassCastException may be thrown.
        Specified by:
        sorted in interface LinearSeq<T>
        Specified by:
        sorted in interface Seq<T>
        Returns:
        A sorted version of this
      • sorted

        public Queue<T> sorted​(java.util.Comparator<? super T> comparator)
        Description copied from interface: Seq
        Sorts this elements according to the provided Comparator. If this elements are not Comparable, a java.lang.ClassCastException may be thrown.
        Specified by:
        sorted in interface LinearSeq<T>
        Specified by:
        sorted in interface Seq<T>
        Parameters:
        comparator - A comparator
        Returns:
        a sorted version of this
      • sortBy

        public <U extends java.lang.Comparable<? super U>> Queue<T> sortBy​(java.util.function.Function<? super T,​? extends U> mapper)
        Description copied from interface: Seq
        Sorts this elements by comparing the elements in a different domain, using the given mapper.
        Specified by:
        sortBy in interface LinearSeq<T>
        Specified by:
        sortBy in interface Seq<T>
        Type Parameters:
        U - The domain where elements are compared
        Parameters:
        mapper - A mapper
        Returns:
        a sorted version of this
      • sortBy

        public <U> Queue<T> sortBy​(java.util.Comparator<? super U> comparator,
                                   java.util.function.Function<? super T,​? extends U> mapper)
        Description copied from interface: Seq
        Sorts this elements by comparing the elements in a different domain, using the given mapper.
        Specified by:
        sortBy in interface LinearSeq<T>
        Specified by:
        sortBy in interface Seq<T>
        Type Parameters:
        U - The domain where elements are compared
        Parameters:
        comparator - A comparator
        mapper - A mapper
        Returns:
        a sorted version of this
      • span

        public Tuple2<Queue<T>,​Queue<T>> span​(java.util.function.Predicate<? super T> predicate)
        Description copied from interface: Traversable
        Returns a tuple where the first element is the longest prefix of elements that satisfy the given predicate and the second element is the remainder.
        Specified by:
        span in interface LinearSeq<T>
        Specified by:
        span in interface Seq<T>
        Specified by:
        span in interface Traversable<T>
        Parameters:
        predicate - A predicate.
        Returns:
        a Tuple containing the longest prefix of elements that satisfy p and the remainder.
      • splitAt

        public Tuple2<Queue<T>,​Queue<T>> splitAt​(int n)
        Description copied from interface: Seq
        Splits a Seq at the specified index. The result of splitAt(n) is equivalent to Tuple.of(take(n), drop(n)).
        Specified by:
        splitAt in interface Seq<T>
        Parameters:
        n - An index.
        Returns:
        A Tuple containing the first n and the remaining elements.
      • splitAt

        public Tuple2<Queue<T>,​Queue<T>> splitAt​(java.util.function.Predicate<? super T> predicate)
        Description copied from interface: Seq
        Splits a sequence at the first element which satisfies the Predicate, e.g. Tuple(init, element+tail).
        Specified by:
        splitAt in interface Seq<T>
        Parameters:
        predicate - An predicate
        Returns:
        A Tuple containing divided sequences
      • splitAtInclusive

        public Tuple2<Queue<T>,​Queue<T>> splitAtInclusive​(java.util.function.Predicate<? super T> predicate)
        Description copied from interface: Seq
        Splits a sequence at the first element which satisfies the Predicate, e.g. Tuple(init+element, tail).
        Specified by:
        splitAtInclusive in interface Seq<T>
        Parameters:
        predicate - An predicate
        Returns:
        A Tuple containing divided sequences
      • startsWith

        public boolean startsWith​(java.lang.Iterable<? extends T> that,
                                  int offset)
        Description copied from interface: Seq
        Tests whether this list contains the given sequence at a given index.

        Note: If the both the receiver object this and the argument that are infinite sequences this method may not terminate.

        Specified by:
        startsWith in interface Seq<T>
        Parameters:
        that - the sequence to test
        offset - the index where the sequence is searched.
        Returns:
        true if that is empty or that is prefix of this collection starting from the given offset, false otherwise.
      • subSequence

        public Queue<T> subSequence​(int beginIndex)
        Description copied from interface: Seq
        Returns a Seq that is a subsequence of this. The subsequence begins with the element at the specified beginIndex and extends to the end of this Seq.

        Examples:

         
         List.of(1, 2).subSequence(0);     // = (1, 2)
         List.of(1, 2).subSequence(1);     // = (2)
         List.of(1, 2).subSequence(2);     // = ()
         List.of(1, 2).subSequence(10);    // throws IndexOutOfBoundsException
         List.of(1, 2).subSequence(-10);   // throws IndexOutOfBoundsException
         
         
        See also Seq.drop(int) which is similar but does not throw.
        Specified by:
        subSequence in interface LinearSeq<T>
        Specified by:
        subSequence in interface Seq<T>
        Parameters:
        beginIndex - the beginning index, inclusive
        Returns:
        the specified subsequence
      • subSequence

        public Queue<T> subSequence​(int beginIndex,
                                    int endIndex)
        Description copied from interface: Seq
        Returns a Seq that is a subsequence of this. The subsequence begins with the element at the specified beginIndex and extends to the element at index endIndex - 1.

        Examples:

         
         List.of(1, 2, 3, 4).subSequence(1, 3); // = (2, 3)
         List.of(1, 2, 3, 4).subSequence(0, 4); // = (1, 2, 3, 4)
         List.of(1, 2, 3, 4).subSequence(2, 2); // = ()
         List.of(1, 2).subSequence(1, 0);       // throws IndexOutOfBoundsException
         List.of(1, 2).subSequence(-10, 1);     // throws IndexOutOfBoundsException
         List.of(1, 2).subSequence(0, 10);      // throws IndexOutOfBoundsException
         
         
        See also Seq.slice(int, int) which returns an empty sequence instead of throwing.
        Specified by:
        subSequence in interface LinearSeq<T>
        Specified by:
        subSequence in interface Seq<T>
        Parameters:
        beginIndex - the beginning index, inclusive
        endIndex - the end index, exclusive
        Returns:
        the specified subsequence
      • tail

        public Queue<T> tail()
        Drops the first element of a non-empty Traversable.
        Specified by:
        tail in interface LinearSeq<T>
        Specified by:
        tail in interface Seq<T>
        Specified by:
        tail in interface Traversable<T>
        Returns:
        A new instance of Traversable containing all elements except the first.
      • take

        public Queue<T> take​(int n)
        Description copied from interface: Traversable
        Takes the first n elements of this or all elements, if this length < n.

        The result is equivalent to sublist(0, max(0, min(length(), n))) but does not throw if n < 0 or n > length().

        In the case of n < 0 the empty instance is returned, in the case of n > length() this is returned.

        Specified by:
        take in interface LinearSeq<T>
        Specified by:
        take in interface Seq<T>
        Specified by:
        take in interface Traversable<T>
        Parameters:
        n - The number of elements to take.
        Returns:
        A new instance consisting of the first n elements of this or all elements, if this has less than n elements.
      • takeUntil

        public Queue<T> takeUntil​(java.util.function.Predicate<? super T> predicate)
        Description copied from interface: Traversable
        Takes elements until the predicate holds for the current element.

        Note: This is essentially the same as takeWhile(predicate.negate()). It is intended to be used with method references, which cannot be negated directly.

        Specified by:
        takeUntil in interface LinearSeq<T>
        Specified by:
        takeUntil in interface Seq<T>
        Specified by:
        takeUntil in interface Traversable<T>
        Parameters:
        predicate - A condition tested subsequently for this elements.
        Returns:
        a new instance consisting of all elements before the first one which does satisfy the given predicate.
      • takeRight

        public Queue<T> takeRight​(int n)
        Description copied from interface: Traversable
        Takes the last n elements of this or all elements, if this length < n.

        The result is equivalent to sublist(max(0, min(length(), length() - n)), n), i.e. takeRight will not throw if n < 0 or n > length().

        In the case of n < 0 the empty instance is returned, in the case of n > length() this is returned.

        Specified by:
        takeRight in interface LinearSeq<T>
        Specified by:
        takeRight in interface Seq<T>
        Specified by:
        takeRight in interface Traversable<T>
        Parameters:
        n - The number of elements to take.
        Returns:
        A new instance consisting of the last n elements of this or all elements, if this has less than n elements.
      • takeRightUntil

        public Queue<T> takeRightUntil​(java.util.function.Predicate<? super T> predicate)
        Description copied from interface: Seq
        Takes elements until the predicate holds for the current element, starting from the end.
        Specified by:
        takeRightUntil in interface LinearSeq<T>
        Specified by:
        takeRightUntil in interface Seq<T>
        Parameters:
        predicate - A condition tested subsequently for this elements, starting from the end.
        Returns:
        a new instance consisting of all elements after the last one which does satisfy the given predicate.
      • takeRightWhile

        public Queue<T> takeRightWhile​(java.util.function.Predicate<? super T> predicate)
        Description copied from interface: Seq
        Takes elements while the predicate holds for the current element, starting from the end.

        Note: This is essentially the same as takeRightUntil(predicate.negate()). It is intended to be used with method references, which cannot be negated directly.

        Specified by:
        takeRightWhile in interface LinearSeq<T>
        Specified by:
        takeRightWhile in interface Seq<T>
        Parameters:
        predicate - A condition tested subsequently for this elements, starting from the end.
        Returns:
        a new instance consisting of all elements after the last one which does not satisfy the given predicate.
      • transform

        public <U> U transform​(java.util.function.Function<? super Queue<T>,​? extends U> f)
        Transforms this Queue.
        Type Parameters:
        U - Type of transformation result
        Parameters:
        f - A transformation
        Returns:
        An instance of type U
        Throws:
        java.lang.NullPointerException - if f is null
      • unzip

        public <T1,​T2> Tuple2<Queue<T1>,​Queue<T2>> unzip​(java.util.function.Function<? super T,​Tuple2<? extends T1,​? extends T2>> unzipper)
        Description copied from interface: Traversable
        Unzips this elements by mapping this elements to pairs which are subsequently split into two distinct sets.
        Specified by:
        unzip in interface LinearSeq<T>
        Specified by:
        unzip in interface Seq<T>
        Specified by:
        unzip in interface Traversable<T>
        Type Parameters:
        T1 - 1st element type of a pair returned by unzipper
        T2 - 2nd element type of a pair returned by unzipper
        Parameters:
        unzipper - a function which converts elements of this to pairs
        Returns:
        A pair of set containing elements split by unzipper
      • unzip3

        public <T1,​T2,​T3> Tuple3<Queue<T1>,​Queue<T2>,​Queue<T3>> unzip3​(java.util.function.Function<? super T,​Tuple3<? extends T1,​? extends T2,​? extends T3>> unzipper)
        Description copied from interface: Traversable
        Unzips this elements by mapping this elements to triples which are subsequently split into three distinct sets.
        Specified by:
        unzip3 in interface Seq<T>
        Specified by:
        unzip3 in interface Traversable<T>
        Type Parameters:
        T1 - 1st element type of a triplet returned by unzipper
        T2 - 2nd element type of a triplet returned by unzipper
        T3 - 3rd element type of a triplet returned by unzipper
        Parameters:
        unzipper - a function which converts elements of this to pairs
        Returns:
        A triplet of set containing elements split by unzipper
      • update

        public Queue<T> update​(int index,
                               T element)
        Description copied from interface: Seq
        Updates the given element at the specified index.
        Specified by:
        update in interface LinearSeq<T>
        Specified by:
        update in interface Seq<T>
        Parameters:
        index - an index
        element - an element
        Returns:
        a new Seq consisting of all previous elements, with a single one (at the given index), changed to the new value.
      • update

        public Queue<T> update​(int index,
                               java.util.function.Function<? super T,​? extends T> updater)
        Description copied from interface: Seq
        Updates the given element at the specified index using the specified function.
        Specified by:
        update in interface LinearSeq<T>
        Specified by:
        update in interface Seq<T>
        Parameters:
        index - an index
        updater - a function transforming the previous value
        Returns:
        a new Seq consisting of all previous elements, with a single one (at the given index), changed to the new value.
      • zip

        public <U> Queue<Tuple2<T,​U>> zip​(java.lang.Iterable<? extends U> that)
        Description copied from interface: Traversable
        Returns a traversable formed from this traversable and another Iterable collection by combining corresponding elements in pairs. If one of the two iterables is longer than the other, its remaining elements are ignored.

        The length of the returned traversable is the minimum of the lengths of this traversable and that iterable.

        Specified by:
        zip in interface LinearSeq<T>
        Specified by:
        zip in interface Seq<T>
        Specified by:
        zip in interface Traversable<T>
        Type Parameters:
        U - The type of the second half of the returned pairs.
        Parameters:
        that - The Iterable providing the second half of each result pair.
        Returns:
        a new traversable containing pairs consisting of corresponding elements of this traversable and that iterable.
      • zipWith

        public <U,​R> Queue<R> zipWith​(java.lang.Iterable<? extends U> that,
                                            java.util.function.BiFunction<? super T,​? super U,​? extends R> mapper)
        Description copied from interface: Traversable
        Returns a traversable formed from this traversable and another Iterable collection by mapping elements. If one of the two iterables is longer than the other, its remaining elements are ignored.

        The length of the returned traversable is the minimum of the lengths of this traversable and that iterable.

        Specified by:
        zipWith in interface LinearSeq<T>
        Specified by:
        zipWith in interface Seq<T>
        Specified by:
        zipWith in interface Traversable<T>
        Type Parameters:
        U - The type of the second parameter of the mapper.
        R - The type of the mapped elements.
        Parameters:
        that - The Iterable providing the second parameter of the mapper.
        mapper - a mapper.
        Returns:
        a new traversable containing mapped elements of this traversable and that iterable.
      • zipAll

        public <U> Queue<Tuple2<T,​U>> zipAll​(java.lang.Iterable<? extends U> that,
                                                   T thisElem,
                                                   U thatElem)
        Description copied from interface: Traversable
        Returns a traversable formed from this traversable and another Iterable by combining corresponding elements in pairs. If one of the two collections is shorter than the other, placeholder elements are used to extend the shorter collection to the length of the longer.

        The length of the returned traversable is the maximum of the lengths of this traversable and that iterable.

        Special case: if this traversable is shorter than that elements, and that elements contains duplicates, the resulting traversable may be shorter than the maximum of the lengths of this and that because a traversable contains an element at most once.

        If this Traversable is shorter than that, thisElem values are used to fill the result. If that is shorter than this Traversable, thatElem values are used to fill the result.

        Specified by:
        zipAll in interface LinearSeq<T>
        Specified by:
        zipAll in interface Seq<T>
        Specified by:
        zipAll in interface Traversable<T>
        Type Parameters:
        U - The type of the second half of the returned pairs.
        Parameters:
        that - The Iterable providing the second half of each result pair.
        thisElem - The element to be used to fill up the result if this traversable is shorter than that.
        thatElem - The element to be used to fill up the result if that is shorter than this traversable.
        Returns:
        A new traversable containing pairs consisting of corresponding elements of this traversable and that.
      • zipWithIndex

        public Queue<Tuple2<T,​java.lang.Integer>> zipWithIndex()
        Description copied from interface: Traversable
        Zips this traversable with its indices.
        Specified by:
        zipWithIndex in interface LinearSeq<T>
        Specified by:
        zipWithIndex in interface Seq<T>
        Specified by:
        zipWithIndex in interface Traversable<T>
        Returns:
        A new traversable containing all elements of this traversable paired with their index, starting with 0.
      • zipWithIndex

        public <U> Queue<U> zipWithIndex​(java.util.function.BiFunction<? super T,​? super java.lang.Integer,​? extends U> mapper)
        Description copied from interface: Traversable
        Returns a traversable formed from this traversable and another Iterable collection by mapping elements. If one of the two iterables is longer than the other, its remaining elements are ignored.

        The length of the returned traversable is the minimum of the lengths of this traversable and that iterable.

        Specified by:
        zipWithIndex in interface LinearSeq<T>
        Specified by:
        zipWithIndex in interface Seq<T>
        Specified by:
        zipWithIndex in interface Traversable<T>
        Type Parameters:
        U - The type of the mapped elements.
        Parameters:
        mapper - a mapper.
        Returns:
        a new traversable containing mapped elements of this traversable and that iterable.
      • stringPrefix

        public java.lang.String stringPrefix()
        Description copied from interface: Value
        Returns the name of this Value type, which is used by toString().
        Specified by:
        stringPrefix in interface Value<T>
        Returns:
        This type name.
      • equals

        public boolean equals​(java.lang.Object o)
        Description copied from interface: Traversable
        In Vavr there are four basic classes of collections:
        • Seq (sequential elements)
        • Set (distinct elements)
        • Map (indexed elements)
        • Multimap (indexed collections)
        Two collection instances of these classes are equal if and only if both collections
        • belong to the same basic collection class (Seq, Set, Map or Multimap)
        • contain the same elements
        • have the same element order, if the collections are of type Seq
        Two Map/Multimap elements, resp. entries, (key1, value1) and (key2, value2) are equal, if the keys are equal and the values are equal.

        Notes:

        • No collection instance equals null, e.g. Queue(1) not equals null.
        • Nulls are allowed and handled as expected, e.g. List(null, 1) equals Stream(null, 1) and HashMap((null, 1)) equals LinkedHashMap((null, 1)).
        • The element order is taken into account for Seq only. E.g. List(null, 1) not equals Stream(1, null) and HashMap((null, 1), ("a", null)) equals LinkedHashMap(("a", null), (null, 1)). The reason is, that we do not know which implementations we compare when having two instances of type Map, Multimap or Set (see Liskov Substitution Principle).
        • Other collection classes are equal if their types are equal and their elements are equal (in iteration order).
        • Iterator equality is defined to be object reference equality.
        Specified by:
        equals in interface Traversable<T>
        Specified by:
        equals in interface Value<T>
        Overrides:
        equals in class java.lang.Object
        Parameters:
        o - an object, may be null
        Returns:
        true, if this collection equals the given object according to the rules described above, false otherwise.
      • hashCode

        public int hashCode()
        Description copied from interface: Traversable
        Returns the hash code of this collection.
        We distinguish between two types of hashes, those for collections with predictable iteration order (like Seq) and those with arbitrary iteration order (like Set, Map and Multimap).
        In all cases the hash of an empty collection is defined to be 1.
        Collections with predictable iteration order are hashed as follows:
        
         int hash = 1;
         for (T t : this) { hash = hash * 31 + Objects.hashCode(t); }
         
        Collections with arbitrary iteration order are hashed in a way such that the hash of a fixed number of elements is independent of their iteration order.
        
         int hash = 1;
         for (T t : this) { hash += Objects.hashCode(t); }
         
        Please note that the particular hashing algorithms may change in a future version of Vavr.
        Generally, hash codes of collections aren't cached in Vavr (opposed to the size/length). Storing hash codes in order to reduce the time complexity would increase the memory footprint. Persistent collections are built upon tree structures, it allows us to implement efficient memory sharing. A drawback of tree structures is that they make it necessary to store collection attributes at each tree node (read: element).
        The computation of the hash code is linear in time, i.e. O(n). If the hash code of a collection is re-calculated often, e.g. when using a List as HashMap key, we might want to cache the hash code. This can be achieved by simply using a wrapper class, which is not included in Vavr but could be implemented like this:
        public final class Hashed<K> {
        
             private final K key;
             private final Lazy<Integer> hashCode;
        
             public Hashed(K key) {
                 this.key = key;
                 this.hashCode = Lazy.of(() -> Objects.hashCode(key));
             }
        
             public K key() {
                 return key;
             }
        
             &#64;Override
             public boolean equals(Object o) {
                 if (o == key) {
                     return true;
                 } else if (key != null && o instanceof Hashed) {
                     final Hashed that = (Hashed) o;
                     return key.equals(that.key);
                 } else {
                     return false;
                 }
             }
        
             &#64;Override
             public int hashCode() {
                 return hashCode.get();
             }
        
             &#64;Override
             public String toString() {
                 return "Hashed(" + (key == null ? "null" : key.toString()) + ")";
             }
         }
        Specified by:
        hashCode in interface Traversable<T>
        Specified by:
        hashCode in interface Value<T>
        Overrides:
        hashCode in class java.lang.Object
        Returns:
        The hash code of this collection
      • 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:
        java.util.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 Q enqueue​(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 - Elements, may be empty
        Returns:
        a new Queue instance, containing the new elements
        Throws:
        java.lang.NullPointerException - if elements is null
      • peek

        public T peek()
        Returns the first element without modifying it.
        Returns:
        the first element
        Throws:
        java.util.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​(java.util.function.Predicate<? super T> predicate)
        Description copied from interface: Traversable
        Drops elements until the predicate holds for the current element.
        Specified by:
        dropUntil in interface Traversable<T>
        Parameters:
        predicate - A condition tested subsequently for this elements.
        Returns:
        a new instance consisting of all elements starting from the first one which does satisfy the given predicate.
      • filterNot

        public Q filterNot​(java.util.function.Predicate<? super T> predicate)
        Description copied from interface: Traversable
        Returns a new traversable consisting of all elements which do not satisfy the given predicate.

        The default implementation is equivalent to

        filter(predicate.negate()
        Specified by:
        filterNot in interface Traversable<T>
        Parameters:
        predicate - A predicate
        Returns:
        a new traversable
      • tailOption

        public Option<Q> tailOption()
        Description copied from interface: Traversable
        Drops the first element of a non-empty Traversable and returns an Option.
        Specified by:
        tailOption in interface Traversable<T>
        Returns:
        Some(traversable) or None if this is empty.
      • retainAll

        public Q retainAll​(java.lang.Iterable<? extends T> elements)
        Description copied from interface: Traversable
        Keeps all occurrences of the given elements from this.
        Specified by:
        retainAll in interface Traversable<T>
        Parameters:
        elements - Elements to be kept.
        Returns:
        a Traversable containing all occurrences of the given elements.
      • removeAll

        public Q removeAll​(java.lang.Iterable<? extends T> elements)
      • removeAll

        @Deprecated
        public Q removeAll​(java.util.function.Predicate<? super T> predicate)
        Deprecated.
      • reject

        @Deprecated
        public Q reject​(java.util.function.Predicate<? super T> predicate)
        Deprecated.
        Description copied from interface: Traversable
        Returns a new traversable consisting of all elements which do not satisfy the given predicate.

        The default implementation is equivalent to

        filter(predicate.negate()
        Specified by:
        reject in interface Traversable<T>
        Parameters:
        predicate - A predicate
        Returns:
        a new traversable
      • takeWhile

        public Q takeWhile​(java.util.function.Predicate<? super T> predicate)
        Description copied from interface: Traversable
        Takes elements while the predicate holds for the current element.
        Specified by:
        takeWhile in interface Traversable<T>
        Parameters:
        predicate - A condition tested subsequently for the contained elements.
        Returns:
        a new instance consisting of all elements before the first one which does not satisfy the given predicate.
      • peek

        public Q peek​(java.util.function.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 java.lang.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 java.lang.Object
        Returns:
        A String representation of this object