Package one.util.streamex

Class LongStreamEx

    • Method Detail

      • remove

        public LongStreamEx remove​(LongPredicate predicate)
        Returns a stream consisting of the elements of this stream that don't match the given predicate.

        This is an intermediate operation.

        Parameters:
        predicate - a non-interfering, stateless predicate to apply to each element to determine if it should be excluded
        Returns:
        the new stream

      • has

        public boolean has​(long value)
        Returns true if this stream contains the specified value

        This is a short-circuiting terminal operation.

        Parameters:
        value - the value too look for in the stream
        Returns:
        true if this stream contains the specified value
        See Also:
        LongStream.anyMatch(LongPredicate)

      • without

        public LongStreamEx without​(long value)
        Returns a stream consisting of the elements of this stream that don't equal to the given value.

        This is an intermediate operation.

        Parameters:
        value - the value to remove from the stream.
        Returns:
        the new stream
        Since:
        0.2.2
        See Also:
        without(long...), remove(LongPredicate)

      • without

        public LongStreamEx without​(long... values)
        Returns a stream consisting of the elements of this stream that don't equal to any of the supplied values.

        This is an intermediate operation. May return itself if no values were supplied.

        Current implementation scans the supplied values linearly for every stream element.

        If the values array is changed between calling this method and finishing the stream traversal, then the result of the stream traversal is undefined: changes may or may not be taken into account.

        Parameters:
        values - the values to remove from the stream.
        Returns:
        the new stream
        Since:
        0.5.5
        See Also:
        without(long), remove(LongPredicate)

      • greater

        public LongStreamEx greater​(long value)
        Returns a stream consisting of the elements of this stream that strictly greater than the specified value.

        This is an intermediate operation.

        Parameters:
        value - a value to compare to
        Returns:
        the new stream
        Since:
        0.2.3

      • atLeast

        public LongStreamEx atLeast​(long value)
        Returns a stream consisting of the elements of this stream that greater than or equal to the specified value.

        This is an intermediate operation.

        Parameters:
        value - a value to compare to
        Returns:
        the new stream
        Since:
        0.2.3

      • less

        public LongStreamEx less​(long value)
        Returns a stream consisting of the elements of this stream that strictly less than the specified value.

        This is an intermediate operation.

        Parameters:
        value - a value to compare to
        Returns:
        the new stream
        Since:
        0.2.3

      • atMost

        public LongStreamEx atMost​(long value)
        Returns a stream consisting of the elements of this stream that less than or equal to the specified value.

        This is an intermediate operation.

        Parameters:
        value - a value to compare to
        Returns:
        the new stream
        Since:
        0.2.3

      • mapLast

        public LongStreamEx mapLast​(LongUnaryOperator mapper)
        Returns a stream where the last element is the replaced with the result of applying the given function while the other elements are left intact.

        This is a quasi-intermediate operation.

        The mapper function is called at most once. It could be not called at all if the stream is empty or there is short-circuiting operation downstream.

        Parameters:
        mapper - a non-interfering , stateless function to apply to the last element
        Returns:
        the new stream
        Since:
        0.4.1

      • mapToEntry

        public <K,​V> EntryStream<K,​V> mapToEntry​(LongFunction<? extends K> keyMapper,
                                                     LongFunction<? extends V> valueMapper)
        Returns an EntryStream consisting of the Map.Entry objects which keys and values are results of applying the given functions to the elements of this stream.

        This is an intermediate operation.

        Type Parameters:
        K - The Entry key type
        V - The Entry value type
        Parameters:
        keyMapper - a non-interfering, stateless function to apply to each element
        valueMapper - a non-interfering, stateless function to apply to each element
        Returns:
        the new stream
        Since:
        0.3.1

      • flatMapToInt

        public IntStreamEx flatMapToInt​(LongFunction<? extends IntStream> mapper)
        Returns an IntStreamEx consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element. Each mapped stream is closed after its contents have been placed into this stream. (If a mapped stream is null an empty stream is used, instead.)

        This is an intermediate operation.

        Parameters:
        mapper - a non-interfering, stateless function to apply to each element which produces an IntStream of new values
        Returns:
        the new stream
        Since:
        0.3.0

      • flatMapToDouble

        public DoubleStreamEx flatMapToDouble​(LongFunction<? extends DoubleStream> mapper)
        Returns a DoubleStreamEx consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element. Each mapped stream is closed after its contents have been placed into this stream. (If a mapped stream is null an empty stream is used, instead.)

        This is an intermediate operation.

        Parameters:
        mapper - a non-interfering, stateless function to apply to each element which produces an DoubleStream of new values
        Returns:
        the new stream
        Since:
        0.3.0

      • flatMapToObj

        public <R> StreamEx<R> flatMapToObj​(LongFunction<? extends Stream<R>> mapper)
        Returns a StreamEx consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element. Each mapped stream is closed after its contents have been placed into this stream. (If a mapped stream is null an empty stream is used, instead.)

        This is an intermediate operation.

        Type Parameters:
        R - The element type of the new stream
        Parameters:
        mapper - a non-interfering, stateless function to apply to each element which produces a Stream of new values
        Returns:
        the new stream
        Since:
        0.3.0

      • intersperse

        public LongStreamEx intersperse​(int delimiter)
        Returns a new stream containing all the elements of the original stream interspersed with given delimiter.

        For example, LongStreamEx.of(1, 2, 3).intersperse(4) will yield a stream containing five elements: 1, 4, 2, 4, 3.

        This is an intermediate operation.

        Parameters:
        delimiter - a delimiter to be inserted between each pair of elements
        Returns:
        the new stream
        Since:
        0.6.6

      • sorted

        public LongStreamEx sorted​(Comparator<Long> comparator)
        Returns a stream consisting of the elements of this stream sorted according to the given comparator. Stream elements are boxed before passing to the comparator.

        For ordered streams, the sort is stable. For unordered streams, no stability guarantees are made.

        This is a stateful intermediate operation.

        Parameters:
        comparator - a non-interfering , stateless Comparator to be used to compare stream elements
        Returns:
        the new stream

      • reverseSorted

        public LongStreamEx reverseSorted()
        Returns a stream consisting of the elements of this stream in reverse sorted order.

        This is a stateful intermediate operation.

        Returns:
        the new stream
        Since:
        0.0.8

      • sortedBy

        public <V extends Comparable<? super V>> LongStreamEx sortedBy​(LongFunction<V> keyExtractor)
        Returns a stream consisting of the elements of this stream, sorted according to the natural order of the keys extracted by provided function.

        For ordered streams, the sort is stable. For unordered streams, no stability guarantees are made.

        This is a stateful intermediate operation.

        Type Parameters:
        V - the type of the Comparable sort key
        Parameters:
        keyExtractor - a non-interfering , stateless function to be used to extract sorting keys
        Returns:
        the new stream

      • sortedByInt

        public LongStreamEx sortedByInt​(LongToIntFunction keyExtractor)
        Returns a stream consisting of the elements of this stream, sorted according to the int values extracted by provided function.

        For ordered streams, the sort is stable. For unordered streams, no stability guarantees are made.

        This is a stateful intermediate operation.

        Parameters:
        keyExtractor - a non-interfering , stateless function to be used to extract sorting keys
        Returns:
        the new stream

      • sortedByLong

        public LongStreamEx sortedByLong​(LongUnaryOperator keyExtractor)
        Returns a stream consisting of the elements of this stream, sorted according to the long values extracted by provided function.

        For ordered streams, the sort is stable. For unordered streams, no stability guarantees are made.

        This is a stateful intermediate operation.

        Parameters:
        keyExtractor - a non-interfering , stateless function to be used to extract sorting keys
        Returns:
        the new stream

      • sortedByDouble

        public LongStreamEx sortedByDouble​(LongToDoubleFunction keyExtractor)
        Returns a stream consisting of the elements of this stream, sorted according to the double values extracted by provided function.

        For ordered streams, the sort is stable. For unordered streams, no stability guarantees are made.

        This is a stateful intermediate operation.

        Parameters:
        keyExtractor - a non-interfering , stateless function to be used to extract sorting keys
        Returns:
        the new stream

      • peekFirst

        public LongStreamEx peekFirst​(LongConsumer action)
        Returns a stream consisting of the elements of this stream, additionally performing the provided action on the first stream element when it's consumed from the resulting stream.

        This is an intermediate operation.

        The action is called at most once. For parallel stream pipelines, it's not guaranteed in which thread it will be executed, so if it modifies shared state, it is responsible for providing the required synchronization.

        Note that the action might not be called at all if the first element is not consumed from the input (for example, if there's short-circuiting operation downstream which stopped the stream before the first element).

        This method exists mainly to support debugging.

        Parameters:
        action - a non-interfering action to perform on the first stream element as it is consumed from the stream
        Returns:
        the new stream
        Since:
        0.6.0

      • peekLast

        public LongStreamEx peekLast​(LongConsumer action)
        Returns a stream consisting of the elements of this stream, additionally performing the provided action on the last stream element when it's consumed from the resulting stream.

        This is an intermediate operation.

        The action is called at most once. For parallel stream pipelines, it's not guaranteed in which thread it will be executed, so if it modifies shared state, it is responsible for providing the required synchronization.

        Note that the action might not be called at all if the last element is not consumed from the input (for example, if there's short-circuiting operation downstream).

        This method exists mainly to support debugging.

        Parameters:
        action - a non-interfering action to perform on the first stream element as it is consumed from the stream
        Returns:
        the new stream
        Since:
        0.6.0

      • foldLeft

        public OptionalLong foldLeft​(LongBinaryOperator accumulator)
        Folds the elements of this stream using the provided accumulation function, going left to right. This is equivalent to: 
         
     boolean foundAny = false;
     long result = 0;
     for (long element : this stream) {
         if (!foundAny) {
             foundAny = true;
             result = element;
         }
         else
             result = accumulator.apply(result, element);
     }
     return foundAny ? OptionalLong.of(result) : OptionalLong.empty();

        This is a terminal operation.

        This method cannot take all the advantages of parallel streams as it must process elements strictly left to right. If your accumulator function is associative, consider using reduce(LongBinaryOperator) method.

        For parallel stream it's not guaranteed that accumulator will always be executed in the same thread.

        Parameters:
        accumulator - a non-interfering , stateless function for incorporating an additional element into a result
        Returns:
        the result of the folding
        Since:
        0.4.0
        See Also:
        foldLeft(long, LongBinaryOperator), reduce(LongBinaryOperator)

      • foldLeft

        public long foldLeft​(long seed,
                     LongBinaryOperator accumulator)
        Folds the elements of this stream using the provided seed object and accumulation function, going left to right. This is equivalent to: 
         
     long result = seed;
     for (long element : this stream)
         result = accumulator.apply(result, element)
     return result;

        This is a terminal operation.

        This method cannot take all the advantages of parallel streams as it must process elements strictly left to right. If your accumulator function is associative, consider using reduce(long, LongBinaryOperator) method.

        For parallel stream it's not guaranteed that accumulator will always be executed in the same thread.

        Parameters:
        seed - the starting value
        accumulator - a non-interfering , stateless function for incorporating an additional element into a result
        Returns:
        the result of the folding
        Since:
        0.4.0
        See Also:
        reduce(long, LongBinaryOperator), foldLeft(LongBinaryOperator)

      • scanLeft

        public long[] scanLeft​(LongBinaryOperator accumulator)
        Produces an array containing cumulative results of applying the accumulation function going left to right.

        This is a terminal operation.

        For parallel stream it's not guaranteed that accumulator will always be executed in the same thread.

        This method cannot take all the advantages of parallel streams as it must process elements strictly left to right.

        Parameters:
        accumulator - a non-interfering , stateless function for incorporating an additional element into a result
        Returns:
        the array where the first element is the first element of this stream and every successor element is the result of applying accumulator function to the previous array element and the corresponding stream element. The resulting array has the same length as this stream.
        Since:
        0.5.1
        See Also:
        foldLeft(LongBinaryOperator)

      • scanLeft

        public long[] scanLeft​(long seed,
                       LongBinaryOperator accumulator)
        Produces an array containing cumulative results of applying the accumulation function going left to right using given seed value.

        This is a terminal operation.

        For parallel stream it's not guaranteed that accumulator will always be executed in the same thread.

        This method cannot take all the advantages of parallel streams as it must process elements strictly left to right.

        Parameters:
        seed - the starting value
        accumulator - a non-interfering , stateless function for incorporating an additional element into a result
        Returns:
        the array where the first element is the seed and every successor element is the result of applying accumulator function to the previous array element and the corresponding stream element. The resulting array is one element longer than this stream.
        Since:
        0.5.1
        See Also:
        foldLeft(long, LongBinaryOperator)

      • collect

        public <A,​R> R collect​(LongCollector<A,​R> collector)
        Performs a mutable reduction operation on the elements of this stream using an LongCollector which encapsulates the supplier, accumulator and merger functions making easier to reuse collection strategies.

        Like reduce(long, LongBinaryOperator), collect operations can be parallelized without requiring additional synchronization.

        This is a terminal operation.

        Type Parameters:
        A - the intermediate accumulation type of the LongCollector
        R - type of the result
        Parameters:
        collector - the LongCollector describing the reduction
        Returns:
        the result of the reduction
        Since:
        0.3.0
        See Also:
        collect(Supplier, ObjLongConsumer, BiConsumer)

      • sum

        public long sum()
        Specified by:
        sum in interface LongStream

      • min

        public OptionalLong min​(Comparator<Long> comparator)
        Returns the minimum element of this stream according to the provided Comparator.

        This is a terminal operation.

        Parameters:
        comparator - a non-interfering, stateless Comparator to compare elements of this stream
        Returns:
        an OptionalLong describing the minimum element of this stream, or an empty OptionalLong if the stream is empty
        Since:
        0.1.2

      • minBy

        public <V extends Comparable<? super V>> OptionalLong minBy​(LongFunction<V> keyExtractor)
        Returns the minimum element of this stream according to the provided key extractor function.

        This is a terminal operation.

        Type Parameters:
        V - the type of the Comparable sort key
        Parameters:
        keyExtractor - a non-interfering, stateless function
        Returns:
        an OptionalLong describing the first element of this stream for which the lowest value was returned by key extractor, or an empty OptionalLong if the stream is empty
        Since:
        0.1.2

      • minByInt

        public OptionalLong minByInt​(LongToIntFunction keyExtractor)
        Returns the minimum element of this stream according to the provided key extractor function.

        This is a terminal operation.

        Parameters:
        keyExtractor - a non-interfering, stateless function
        Returns:
        an OptionalLong describing the first element of this stream for which the lowest value was returned by key extractor, or an empty OptionalLong if the stream is empty
        Since:
        0.1.2

      • minByLong

        public OptionalLong minByLong​(LongUnaryOperator keyExtractor)
        Returns the minimum element of this stream according to the provided key extractor function.

        This is a terminal operation.

        Parameters:
        keyExtractor - a non-interfering, stateless function
        Returns:
        an OptionalLong describing the first element of this stream for which the lowest value was returned by key extractor, or an empty OptionalLong if the stream is empty
        Since:
        0.1.2

      • minByDouble

        public OptionalLong minByDouble​(LongToDoubleFunction keyExtractor)
        Returns the minimum element of this stream according to the provided key extractor function.

        This is a terminal operation.

        Parameters:
        keyExtractor - a non-interfering, stateless function
        Returns:
        an OptionalLong describing the first element of this stream for which the lowest value was returned by key extractor, or an empty OptionalLong if the stream is empty
        Since:
        0.1.2

      • max

        public OptionalLong max​(Comparator<Long> comparator)
        Returns the maximum element of this stream according to the provided Comparator.

        This is a terminal operation.

        Parameters:
        comparator - a non-interfering, stateless Comparator to compare elements of this stream
        Returns:
        an OptionalLong describing the maximum element of this stream, or an empty OptionalLong if the stream is empty

      • maxBy

        public <V extends Comparable<? super V>> OptionalLong maxBy​(LongFunction<V> keyExtractor)
        Returns the maximum element of this stream according to the provided key extractor function.

        This is a terminal operation.

        Type Parameters:
        V - the type of the Comparable sort key
        Parameters:
        keyExtractor - a non-interfering, stateless function
        Returns:
        an OptionalLong describing the first element of this stream for which the highest value was returned by key extractor, or an empty OptionalLong if the stream is empty
        Since:
        0.1.2

      • maxByInt

        public OptionalLong maxByInt​(LongToIntFunction keyExtractor)
        Returns the maximum element of this stream according to the provided key extractor function.

        This is a terminal operation.

        Parameters:
        keyExtractor - a non-interfering, stateless function
        Returns:
        an OptionalLong describing the first element of this stream for which the highest value was returned by key extractor, or an empty OptionalLong if the stream is empty
        Since:
        0.1.2

      • maxByLong

        public OptionalLong maxByLong​(LongUnaryOperator keyExtractor)
        Returns the maximum element of this stream according to the provided key extractor function.

        This is a terminal operation.

        Parameters:
        keyExtractor - a non-interfering, stateless function
        Returns:
        an OptionalLong describing the first element of this stream for which the highest value was returned by key extractor, or an empty OptionalLong if the stream is empty
        Since:
        0.1.2

      • maxByDouble

        public OptionalLong maxByDouble​(LongToDoubleFunction keyExtractor)
        Returns the maximum element of this stream according to the provided key extractor function.

        This is a terminal operation.

        Parameters:
        keyExtractor - a non-interfering, stateless function
        Returns:
        an OptionalLong describing the first element of this stream for which the highest value was returned by key extractor, or an empty OptionalLong if the stream is empty
        Since:
        0.1.2

      • count

        public long count()
        Specified by:
        count in interface LongStream

      • findFirst

        public OptionalLong findFirst​(LongPredicate predicate)
        Returns an OptionalLong describing the first element of this stream, which matches given predicate, or an empty OptionalLong if there's no matching element.

        This is a short-circuiting terminal operation.

        Parameters:
        predicate - a non-interfering , stateless predicate which returned value should match
        Returns:
        an OptionalLong describing the first matching element of this stream, or an empty OptionalLong if there's no matching element
        See Also:
        findFirst()

      • findAny

        public OptionalLong findAny​(LongPredicate predicate)
        Returns an OptionalLong describing some element of the stream, which matches given predicate, or an empty OptionalLong if there's no matching element.

        This is a short-circuiting terminal operation.

        The behavior of this operation is explicitly nondeterministic; it is free to select any element in the stream. This is to allow for maximal performance in parallel operations; the cost is that multiple invocations on the same source may not return the same result. (If a stable result is desired, use findFirst(LongPredicate) instead.)

        Parameters:
        predicate - a non-interfering , stateless predicate which returned value should match
        Returns:
        an OptionalLong describing some matching element of this stream, or an empty OptionalLong if there's no matching element
        See Also:
        findAny(), findFirst(LongPredicate)

      • indexOf

        public OptionalLong indexOf​(long value)
        Returns an OptionalLong describing the zero-based index of the first element of this stream, which equals to the given value, or an empty OptionalLong if there's no matching element.

        This is a short-circuiting terminal operation.

        Parameters:
        value - a value to look for
        Returns:
        an OptionalLong describing the index of the first matching element of this stream, or an empty OptionalLong if there's no matching element.
        Since:
        0.4.0
        See Also:
        indexOf(LongPredicate)

      • indexOf

        public OptionalLong indexOf​(LongPredicate predicate)
        Returns an OptionalLong describing the zero-based index of the first element of this stream, which matches given predicate, or an empty OptionalLong if there's no matching element.

        This is a short-circuiting terminal operation.

        Parameters:
        predicate - a non-interfering , stateless predicate which returned value should match
        Returns:
        an OptionalLong describing the index of the first matching element of this stream, or an empty OptionalLong if there's no matching element.
        Since:
        0.4.0
        See Also:
        findFirst(LongPredicate)

      • parallel

        public LongStreamEx parallel​(ForkJoinPool fjp)
        Returns an equivalent stream that is parallel and bound to the supplied ForkJoinPool.

        This is an intermediate operation.

        The terminal operation of this stream or any derived stream (except the streams created via BaseStream.parallel() or BaseStream.sequential() methods) will be executed inside the supplied ForkJoinPool. If current thread does not belong to that pool, it will wait till calculation finishes.

        Parameters:
        fjp - a ForkJoinPool to submit the stream operation to.
        Returns:
        a parallel stream bound to the supplied ForkJoinPool

      • append

        public LongStreamEx append​(long... values)
        Returns a new LongStreamEx which is a concatenation of this stream and the stream containing supplied values

        This is a quasi-intermediate operation.

        Parameters:
        values - the values to append to the stream
        Returns:
        the new stream

      • append

        public LongStreamEx append​(LongStream other)
        Creates a lazily concatenated stream whose elements are all the elements of this stream followed by all the elements of the other stream. The resulting stream is ordered if both of the input streams are ordered, and parallel if either of the input streams is parallel. When the resulting stream is closed, the close handlers for both input streams are invoked.
        Parameters:
        other - the other stream
        Returns:
        this stream appended by the other stream
        See Also:
        LongStream.concat(LongStream, LongStream)

      • prepend

        public LongStreamEx prepend​(long... values)
        Returns a new LongStreamEx which is a concatenation of the stream containing supplied values and this stream

        This is a quasi-intermediate operation.

        Parameters:
        values - the values to prepend to the stream
        Returns:
        the new stream

      • prepend

        public LongStreamEx prepend​(LongStream other)
        Creates a lazily concatenated stream whose elements are all the elements of the other stream followed by all the elements of this stream. The resulting stream is ordered if both of the input streams are ordered, and parallel if either of the input streams is parallel. When the resulting stream is closed, the close handlers for both input streams are invoked.
        Parameters:
        other - the other stream
        Returns:
        this stream prepended by the other stream
        See Also:
        LongStream.concat(LongStream, LongStream)

      • pairMap

        public LongStreamEx pairMap​(LongBinaryOperator mapper)
        Returns a stream consisting of the results of applying the given function to the every adjacent pair of elements of this stream.

        This is a quasi-intermediate operation.

        The output stream will contain one element less than this stream. If this stream contains zero or one element the output stream will be empty.

        Parameters:
        mapper - a non-interfering, stateless function to apply to each adjacent pair of this stream elements.
        Returns:
        the new stream
        Since:
        0.2.1

      • joining

        public String joining​(CharSequence delimiter)
        Returns a String which is the concatenation of the results of calling String.valueOf(long) on each element of this stream, separated by the specified delimiter, in encounter order.

        This is a terminal operation.

        Parameters:
        delimiter - the delimiter to be used between each element
        Returns:
        the result of concatenation. For empty input stream empty String is returned.
        Since:
        0.3.1

      • joining

        public String joining​(CharSequence delimiter,
                      CharSequence prefix,
                      CharSequence suffix)
        Returns a String which is the concatenation of the results of calling String.valueOf(long) on each element of this stream, separated by the specified delimiter, with the specified prefix and suffix in encounter order.

        This is a terminal operation.

        Parameters:
        delimiter - the delimiter to be used between each element
        prefix - the sequence of characters to be used at the beginning of the joined result
        suffix - the sequence of characters to be used at the end of the joined result
        Returns:
        the result of concatenation. For empty input stream prefix + suffix is returned.
        Since:
        0.3.1

      • takeWhile

        public LongStreamEx takeWhile​(LongPredicate predicate)
        Returns a stream consisting of all elements from this stream until the first element which does not match the given predicate is found.

        This is a short-circuiting stateful operation. It can be either intermediate or quasi-intermediate. When using with JDK 1.9 or higher it calls the corresponding JDK 1.9 implementation. When using with JDK 1.8 it uses own implementation.

        While this operation is quite cheap for sequential stream, it can be quite expensive on parallel pipelines.

        Specified by:
        takeWhile in interface LongStream
        Parameters:
        predicate - a non-interfering, stateless predicate to apply to elements.
        Returns:
        the new stream.
        Since:
        0.3.6
        See Also:
        takeWhileInclusive(LongPredicate), dropWhile(LongPredicate)

      • takeWhileInclusive

        public LongStreamEx takeWhileInclusive​(LongPredicate predicate)
        Returns a stream consisting of all elements from this stream until the first element which does not match the given predicate is found (including the first mismatching element).

        This is a quasi-intermediate operation.

        While this operation is quite cheap for sequential stream, it can be quite expensive on parallel pipelines.

        Parameters:
        predicate - a non-interfering, stateless predicate to apply to elements.
        Returns:
        the new stream.
        Since:
        0.5.5
        See Also:
        takeWhile(LongPredicate)

      • dropWhile

        public LongStreamEx dropWhile​(LongPredicate predicate)
        Returns a stream consisting of all elements from this stream starting from the first element which does not match the given predicate. If the predicate is true for all stream elements, an empty stream is returned.

        This is a stateful operation. It can be either intermediate or quasi-intermediate. When using with JDK 1.9 or higher it calls the corresponding JDK 1.9 implementation. When using with JDK 1.8 it uses own implementation.

        While this operation is quite cheap for sequential stream, it can be quite expensive on parallel pipelines.

        Specified by:
        dropWhile in interface LongStream
        Parameters:
        predicate - a non-interfering, stateless predicate to apply to elements.
        Returns:
        the new stream.
        Since:
        0.3.6

      • prefix

        public LongStreamEx prefix​(LongBinaryOperator op)
        Returns a stream containing cumulative results of applying the accumulation function going left to right.

        This is a stateful quasi-intermediate operation.

        This operation resembles scanLeft(LongBinaryOperator), but unlike scanLeft this operation is intermediate and accumulation function must be associative.

        This method cannot take all the advantages of parallel streams as it must process elements strictly left to right. Using an unordered source or removing the ordering constraint with unordered() may improve the parallel processing speed.

        Parameters:
        op - an associative , non-interfering , stateless function for computing the next element based on the previous one
        Returns:
        the new stream.
        Since:
        0.6.1
        See Also:
        scanLeft(LongBinaryOperator)

      • chain

        public <U> U chain​(Function<? super LongStreamEx,​U> mapper)
        Applies the supplied function to this stream and returns the result of the function.

        This method can be used to add more functionality in the fluent style. For example, consider user-defined static method batches(stream, n) which breaks the stream into batches of given length. Normally you would write batches(StreamEx.of(input).map(...), 10).filter(...). Using the chain() method you can write in more fluent manner: StreamEx.of(input).map(...).chain(s -> batches(s, 10)).filter(...).

        You could even go further and define a method which returns a function like <T> UnaryOperator<StreamEx<T>> batches(int n) and use it like this: StreamEx.of(input).map(...).chain(batches(10)).filter(...).

        Type Parameters:
        U - the type of the function result.
        Parameters:
        mapper - function to invoke.
        Returns:
        the result of the function invocation.

      • empty

        public static LongStreamEx empty()
        Returns an empty sequential LongStreamEx.
        Returns:
        an empty sequential stream

      • of

        public static LongStreamEx of​(long element)
        Returns a sequential LongStreamEx containing a single element.
        Parameters:
        element - the single element
        Returns:
        a singleton sequential stream

      • of

        public static LongStreamEx of​(long... elements)
        Returns a sequential ordered LongStreamEx whose elements are the specified values.
        Parameters:
        elements - the elements of the new stream
        Returns:
        the new stream

      • of

        public static LongStreamEx of​(long[] array,
                              int startInclusive,
                              int endExclusive)
        Returns a sequential LongStreamEx with the specified range of the specified array as its source.
        Parameters:
        array - the array, assumed to be unmodified during use
        startInclusive - the first index to cover, inclusive
        endExclusive - index immediately past the last index to cover
        Returns:
        an LongStreamEx for the array range
        Throws:
        ArrayIndexOutOfBoundsException - if startInclusive is negative, endExclusive is less than startInclusive, or endExclusive is greater than the array size
        Since:
        0.1.1
        See Also:
        Arrays.stream(long[], int, int)

      • of

        public static LongStreamEx of​(Long[] array)
        Returns a sequential ordered LongStreamEx whose elements are the unboxed elements of supplied array.
        Parameters:
        array - the array to create the stream from.
        Returns:
        the new stream
        Since:
        0.5.0
        See Also:
        Arrays.stream(Object[])

      • of

        public static LongStreamEx of​(LongBuffer buf)
        Returns a sequential ordered LongStreamEx whose elements are the values in the supplied LongBuffer.

        The resulting stream covers only a portion of LongBuffer content which starts with position (inclusive) and ends with limit (exclusive). Changes in position and limit after the stream creation don't affect the stream.

        The resulting stream does not change the internal LongBuffer state.

        Parameters:
        buf - the LongBuffer to create a stream from
        Returns:
        the new stream
        Since:
        0.6.2

      • of

        public static LongStreamEx of​(LongStream stream)
        Returns a LongStreamEx object which wraps given LongStream.

        The supplied stream must not be consumed or closed when this method is called. No operation must be performed on the supplied stream after it's wrapped.

        Parameters:
        stream - original stream
        Returns:
        the wrapped stream
        Since:
        0.0.8

      • of

        public static LongStreamEx of​(PrimitiveIterator.OfLong iterator)
        Returns a sequential, ordered LongStreamEx created from given PrimitiveIterator.OfLong.

        This method is roughly equivalent to LongStreamEx.of(Spliterators.spliteratorUnknownSize(iterator, ORDERED)) , but may show better performance for parallel processing.

        Use this method only if you cannot provide better Stream source.

        Parameters:
        iterator - an iterator to create the stream from.
        Returns:
        the new stream
        Since:
        0.5.1

      • of

        public static LongStreamEx of​(OptionalLong optional)
        Returns a sequential LongStreamEx containing an OptionalLong value, if present, otherwise returns an empty LongStreamEx.
        Parameters:
        optional - the optional to create a stream of
        Returns:
        a stream with an OptionalLong value if present, otherwise an empty stream
        Since:
        0.1.1

      • of

        public static LongStreamEx of​(Collection<Long> collection)
        Returns a sequential ordered LongStreamEx whose elements are the unboxed elements of supplied collection.
        Parameters:
        collection - the collection to create the stream from.
        Returns:
        the new stream
        See Also:
        Collection.stream()

      • of

        public static LongStreamEx of​(Random random)
        Returns an effectively unlimited stream of pseudorandom long values produced by given Random object.

        A pseudorandom long value is generated as if it's the result of calling the method Random.nextLong().

        Parameters:
        random - a Random object to produce the stream from
        Returns:
        a stream of pseudorandom long values
        See Also:
        Random.longs()

      • of

        public static LongStreamEx of​(Random random,
                              long streamSize)
        Returns a stream producing the given streamSize number of pseudorandom long values.

        A pseudorandom long value is generated as if it's the result of calling the method Random.nextLong()

        Parameters:
        random - a Random object to produce the stream from
        streamSize - the number of values to generate
        Returns:
        a stream of pseudorandom long values
        See Also:
        Random.longs(long)

      • of

        public static LongStreamEx of​(Random random,
                              long randomNumberOrigin,
                              long randomNumberBound)
        Returns an effectively unlimited stream of pseudorandom long values, each conforming to the given origin (inclusive) and bound (exclusive).
        Parameters:
        random - a Random object to produce the stream from
        randomNumberOrigin - the origin (inclusive) of each random value
        randomNumberBound - the bound (exclusive) of each random value
        Returns:
        a stream of pseudorandom long values
        See Also:
        Random.longs(long, long, long)

      • of

        public static LongStreamEx of​(Random random,
                              long streamSize,
                              long randomNumberOrigin,
                              long randomNumberBound)
        Returns a stream producing the given streamSize number of pseudorandom long values, each conforming to the given origin (inclusive) and bound (exclusive).
        Parameters:
        random - a Random object to produce the stream from
        streamSize - the number of values to generate
        randomNumberOrigin - the origin (inclusive) of each random value
        randomNumberBound - the bound (exclusive) of each random value
        Returns:
        a stream of pseudorandom long values
        See Also:
        Random.longs(long, long, long)

      • iterate

        public static LongStreamEx iterate​(long seed,
                                   LongUnaryOperator f)
        Returns an infinite sequential ordered LongStreamEx produced by iterative application of a function f to an initial element seed, producing a stream consisting of seed, f(seed), f(f(seed)), etc.

        The first element (position 0) in the LongStreamEx will be the provided seed. For n > 0, the element at position n, will be the result of applying the function f to the element at position n - 1.

        Parameters:
        seed - the initial element
        f - a function to be applied to to the previous element to produce a new element
        Returns:
        A new sequential LongStream
        See Also:
        iterate(long, LongPredicate, LongUnaryOperator)

      • iterate

        public static LongStreamEx iterate​(long seed,
                                   LongPredicate predicate,
                                   LongUnaryOperator f)
        Returns a sequential ordered LongStreamEx produced by iterative application of a function to an initial element, conditioned on satisfying the supplied predicate. The stream terminates as soon as the predicate function returns false.

        LongStreamEx.iterate should produce the same sequence of elements as produced by the corresponding for-loop: 

        
     for (long index=seed; predicate.test(index); index = f.apply(index)) { 
         ... 
     }

        The resulting sequence may be empty if the predicate does not hold on the seed value. Otherwise the first element will be the supplied seed value, the next element (if present) will be the result of applying the function f to the seed value, and so on iteratively until the predicate indicates that the stream should terminate.

        Parameters:
        seed - the initial element
        predicate - a predicate to apply to elements to determine when the stream must terminate.
        f - a function to be applied to the previous element to produce a new element
        Returns:
        a new sequential LongStreamEx
        Since:
        0.6.0
        See Also:
        iterate(long, LongUnaryOperator)

      • generate

        public static LongStreamEx generate​(LongSupplier s)
        Returns an infinite sequential unordered stream where each element is generated by the provided LongSupplier. This is suitable for generating constant streams, streams of random elements, etc.
        Parameters:
        s - the LongSupplier for generated elements
        Returns:
        a new infinite sequential unordered LongStreamEx
        See Also:
        LongStream.generate(LongSupplier)

      • produce

        public static LongStreamEx produce​(Predicate<LongConsumer> producer)
        Return an ordered stream produced by consecutive calls of the supplied producer until it returns false.

        The producer function may call the passed consumer any number of times and return true if the producer should be called again or false otherwise. It's guaranteed that the producer will not be called anymore, once it returns false.

        This method is particularly useful when producer changes the mutable object which should be left in known state after the full stream consumption. Note however that if a short-circuiting operation is used, then the final state of the mutable object cannot be guaranteed.

        Parameters:
        producer - a predicate which calls the passed consumer to emit stream element(s) and returns true if it producer should be applied again.
        Returns:
        the new stream
        Since:
        0.6.0

      • longs

        public static LongStreamEx longs()
        Returns a sequential ordered LongStreamEx from 0 (inclusive) to Long.MAX_VALUE (exclusive) by an incremental step of 1.
        Returns:
        a sequential LongStreamEx for the range of long elements
        Since:
        0.5.5
        See Also:
        range(long, long)

      • range

        public static LongStreamEx range​(long endExclusive)
        Returns a sequential ordered LongStreamEx from 0 (inclusive) to endExclusive (exclusive) by an incremental step of 1.
        Parameters:
        endExclusive - the exclusive upper bound
        Returns:
        a sequential LongStreamEx for the range of int elements
        Since:
        0.1.1
        See Also:
        range(long, long)

      • range

        public static LongStreamEx range​(long startInclusive,
                                 long endExclusive)
        Returns a sequential ordered LongStreamEx from startInclusive (inclusive) to endExclusive (exclusive) by an incremental step of 1.
        Parameters:
        startInclusive - the (inclusive) initial value
        endExclusive - the exclusive upper bound
        Returns:
        a sequential LongStreamEx for the range of long elements
        See Also:
        LongStream.range(long, long)

      • range

        public static LongStreamEx range​(long startInclusive,
                                 long endExclusive,
                                 long step)
        Returns a sequential ordered LongStreamEx from startInclusive (inclusive) to endExclusive (exclusive) by the specified incremental step. The negative step values are also supported. In this case, the startInclusive should be greater than endExclusive.
        Parameters:
        startInclusive - the (inclusive) initial value
        endExclusive - the exclusive upper (for positive step) or lower (for negative step) bound
        step - the non-zero value which designates the difference between the consecutive values of the resulting stream.
        Returns:
        a sequential LongStreamEx for the range of long elements
        Throws:
        IllegalArgumentException - if step is zero
        Since:
        0.4.0
        See Also:
        range(long, long)

      • rangeClosed

        public static LongStreamEx rangeClosed​(long startInclusive,
                                       long endInclusive)
        Returns a sequential ordered LongStreamEx from startInclusive (inclusive) to endInclusive (inclusive) by an incremental step of 1.
        Parameters:
        startInclusive - the (inclusive) initial value
        endInclusive - the inclusive upper bound
        Returns:
        a sequential LongStreamEx for the range of long elements
        See Also:
        LongStream.rangeClosed(long, long)

      • rangeClosed

        public static LongStreamEx rangeClosed​(long startInclusive,
                                       long endInclusive,
                                       long step)
        Returns a sequential ordered LongStreamEx from startInclusive (inclusive) to endInclusive (inclusive) by the specified incremental step. The negative step values are also supported. In this case, the startInclusive should be not less than endInclusive.

        Note that depending on the step value the endInclusive bound may still not be reached. For example LongStreamEx.rangeClosed(0, 5, 2) will yield the stream of three numbers: 0L, 2L and 4L.

        Parameters:
        startInclusive - the (inclusive) initial value
        endInclusive - the inclusive upper (for positive step) or lower (for negative step) bound
        step - the non-zero value which designates the difference between the consecutive values of the resulting stream.
        Returns:
        a sequential LongStreamEx for the range of long elements; an empty stream if startInclusive is greater than endInclusive for positive step, or if startInclusive is less than endInclusive for negative step.
        Throws:
        IllegalArgumentException - if step is zero
        Since:
        0.4.0
        See Also:
        rangeClosed(long, long)

      • constant

        public static LongStreamEx constant​(long value,
                                    long length)
        Returns a sequential unordered LongStreamEx of given length which elements are equal to supplied value.
        Parameters:
        value - the constant value
        length - the length of the stream
        Returns:
        a new LongStreamEx
        Since:
        0.1.2

      • zip

        public static LongStreamEx zip​(long[] first,
                               long[] second,
                               LongBinaryOperator mapper)
        Returns a sequential LongStreamEx containing the results of applying the given function to the corresponding pairs of values in given two arrays.
        Parameters:
        first - the first array
        second - the second array
        mapper - a non-interfering, stateless function to apply to each pair of the corresponding array elements.
        Returns:
        a new LongStreamEx
        Throws:
        IllegalArgumentException - if length of the arrays differs.
        Since:
        0.2.1