| Modifier and Type | Method and Description |
|---|---|
static <T,Z> Stream<Pair<T,Z>> |
combinations(Stream<T> stream,
Functions.Function0<? extends Stream<Z>> streamSupplier)
This function returns a stream of the Cartesian Product of
stream and the elements of the stream
provided by streamSupplier. |
static <T,Z,R> Stream<R> |
combinations(Stream<T> stream,
Functions.Function0<? extends Stream<Z>> streamSupplier,
Functions.Function2<? super T,? super Z,? extends R> combiner)
This function returns a stream of the Cartesian product of
stream and the elements of the stream
provided by streamSupplier. |
static <T,Z> Stream<Pair<T,Z>> |
combinations(Stream<T> stream,
Iterable<Z> combineWith)
This function returns a stream of the Cartesian product of
stream and the iterable combineWith. |
static <T,Z,R> Stream<R> |
combinations(Stream<T> stream,
Iterable<Z> combineWith,
Functions.Function2<? super T,? super Z,? extends R> combiner)
This function returns a stream of the Cartesian product of
stream and the iterable combineWith. |
static <T,U> Stream<U> |
filter(Stream<T> input,
Class<? extends U> clazz)
Filters the given Stream
input to only contain elements instance
of the given class clazz. |
static <T> Stream<T> |
filterNull(Stream<T> stream)
Filters a
stream to not include null values. |
static <T> Optional<T> |
findAny(Stream<T> stream,
Predicate<T> test)
This method is a shortcut for
stream.filter(test).findAny(). |
static <T> Optional<T> |
findFirst(Stream<T> stream,
Predicate<T> test)
This method is a shortcut for
stream.filter(test).findFirst(). |
static <T,U> Stream<U> |
flatMap(Stream<T> stream,
Functions.Function1<? super T,? extends Iterable<? extends U>> flatMapper)
This method provides a convenient way to
flatMap on a Stream by providing an
Iterable instead of a Stream. |
static <T> Stream<T> |
iterate(Class<Stream> clazz,
T seed,
Predicate<? super T> hasNext,
UnaryOperator<T> next)
This method redirects to
<T>iterate(T, Predicate<? super T>, UnaryOperator<T>).This allows e.g. |
static <T> Stream<T> |
iterate(T seed,
Predicate<? super T> hasNext,
UnaryOperator<T> next)
This method provides functionality that is directly available on the Java 9 Stream class.
This method will construct a Stream that provides seed as an initial element. |
static <T extends Comparable<? super T>> |
max(Stream<T> stream)
This is a shortcut for
stream.max(Comparator.naturalOrder()). |
static <T extends Comparable<? super T>> |
min(Stream<T> stream)
This is a shortcut for
stream.min(Comparator.naturalOrder()). |
static <T> Stream<T> |
operator_plus(Stream<? extends T> first,
Stream<? extends T> second)
Operator shortcut for
Stream.concat(first,second). |
static <T,C extends Collection<T>> |
toCollection(Stream<T> stream,
Supplier<C> collectionFactory)
This function is a simple shortcut for
stream.collect(Collectors.toCollection(collectionFactory)). |
static <T> List<T> |
toList(Stream<T> stream)
This function is a simple shortcut for
stream.collect(Collectors.toList()). |
static <T> Set<T> |
toSet(Stream<T> stream)
This function is a simple shortcut for
stream.collect(Collectors.toSet()). |
public static <T,U> Stream<U> flatMap(Stream<T> stream, Functions.Function1<? super T,? extends Iterable<? extends U>> flatMapper)
flatMap on a Stream by providing an
Iterable instead of a Stream. If a given Iterable is instance of
Collection, the stream() method of the interface will be called.T - Type of elements provided by stream.U - Type of elements flatMapper maps to from T.stream - the input stream; each element will be passed to flatMapper. The resulting
elements will be concatenated to a flat Stream containing all elements of the returned
Iterables.flatMapper - function returning an Iterable for each element in stream.flatMapper for each elements
provided by stream.NullPointerException - if stream or flatMapper is null, or if
flatMapper returns a null object.public static <T,U> Stream<U> filter(Stream<T> input, Class<? extends U> clazz)
input to only contain elements instance
of the given class clazz. Note that the returned stream is of type
Stream<U>, so a stream of the the class it is filtered by.T - Type of elements provided by stream.U - Type, elements in input are checked to be. The resulting stream only
contains elements of that type.input - to be filtered to only contain instances of clazzclazz - object of the class the input should be filtered for.input Stream filtered to only contain instances of clazz.public static <T> Optional<T> findFirst(Stream<T> stream, Predicate<T> test)
stream.filter(test).findFirst().
Meaning this operation will try to find the fist element in the stream
matching the given test. If such an element is found, the returned
Optional will have the found element present. Otherwise an empty Optional
will be returned.T - Type of elements in stream.stream - the stream that will be searched for an element matching
the testtest - the predicate checking for an matching element. An element
is considered a match when the test returns true for a given
element. If test throws an exception this exception will be
thrown from this method.stream
or an empty optional if no element matched test.NullPointerException - if stream or test is nullpublic static <T> Optional<T> findAny(Stream<T> stream, Predicate<T> test)
stream.filter(test).findAny().
Meaning this operation will try to find the an element in the stream
matching the given test. If such an element is found, the returned
Optional will have the found element present. Otherwise an empty Optional
will be returned.T - Type of elements in stream.stream - the stream that will be searched for an element matching
the testtest - the predicate checking for an matching element. An element
is considered a match when the test returns true for a given
element. If test throws an exception this exception will be
thrown from this method.stream
or an empty optional if no element matched test.NullPointerException - if stream or test is nullpublic static <T extends Comparable<? super T>> Optional<T> min(Stream<T> stream)
stream.min(Comparator.naturalOrder()).
This extension method conveniently seaches the minimum element according
to the order implemented via the Comparable interface the elements
of the stream implement.T - Type of elements in stream.stream - the stream to be reduced to the minimum element.public static <T extends Comparable<? super T>> Optional<T> max(Stream<T> stream)
stream.max(Comparator.naturalOrder()).
This extension method conveniently seaches the maximum element according
to the order implemented via the Comparable interface the elements
of the stream implement.T - Type of elements in stream.stream - the stream to be reduced to the maximum element.public static <T> Stream<T> filterNull(Stream<T> stream)
stream to not include null values.T - Type of elements in stream.stream - the stream to be filtered to exclude null values.public static <T> List<T> toList(Stream<T> stream)
stream.collect(Collectors.toList()).T - Type of elements in stream.stream - the stream to be collected into a new List.streampublic static <T> Set<T> toSet(Stream<T> stream)
stream.collect(Collectors.toSet()).T - Type of elements in stream.stream - the stream to be collected into a new Set.streampublic static <T,C extends Collection<T>> C toCollection(Stream<T> stream, Supplier<C> collectionFactory)
stream.collect(Collectors.toCollection(collectionFactory)).
Means that all elements of stream are added to the collection supplied by collectionFactory.T - Type of elements in stream.C - Type of (mutable) collection all elements of stream are added to.stream - the stream to be collected into a new Set.collectionFactory - a Supplier which returns a new, empty
Collection (of an arbitrary sub-type) supporting mutation.streampublic static <T,Z> Stream<Pair<T,Z>> combinations(Stream<T> stream, Iterable<Z> combineWith)
stream and the iterable combineWith.
Note that this function will multiple times try to create a stream from the Iterable combineWith. The
combination of elements of the stream and combineWith are represented as Pairs of the
values from both sources.T - Type of elements in stream.Z - Type of elements in combineWith.stream - the stream that's elements are combined with every elements from combineWithcombineWith - the elements to be combined with each element from streamstream with every element of combineWith.public static <T,Z> Stream<Pair<T,Z>> combinations(Stream<T> stream, Functions.Function0<? extends Stream<Z>> streamSupplier)
stream and the elements of the stream
provided by streamSupplier.
Note that this function will call streamSupplier for each element in stream, so it is expected
that on every call the given streamSupplier returns a stream of the same elements. The
combination of elements of the stream and the stream provided by streamSupplier are represented
as Pairs of the values from both sources.T - Type of elements in stream.Z - Type of elements provided by stream, provided by streamSupplierstream - the stream that's elements are combined with every elements from combineWithstreamSupplier - the elements to be combined with each element from streamstream with every element of the stream provided by streamSupplier.public static <T,Z,R> Stream<R> combinations(Stream<T> stream, Iterable<Z> combineWith, Functions.Function2<? super T,? super Z,? extends R> combiner)
stream and the iterable combineWith.
Note that this function will multiple times try to create a stream from the Iterable combineWith. Every
combination of elements of the stream and combineWith will be passed to the combiner to
create a resulting combined element.T - Type of elements in stream.Z - Type of elements in combineWith.R - Result type of combiner function, which fuses a T and a Z object to one instance of R.stream - the stream that's elements are combined with every elements from combineWithcombineWith - the elements to be combined with each element from streamcombiner - will be used to combine elements from stream and combineWith to result values.stream with every element of combineWith
combined by using the combiner function.public static <T,Z,R> Stream<R> combinations(Stream<T> stream, Functions.Function0<? extends Stream<Z>> streamSupplier, Functions.Function2<? super T,? super Z,? extends R> combiner)
stream and the elements of the stream
provided by streamSupplier.
Note that this function will call streamSupplier for each element in stream, so it is expected
that on every call the given streamSupplier returns a stream of the same elements. Every
combination of elements of the stream and elements of stream provided by streamSupplier will be
passed to the combiner to create a resulting combined element.T - Type of elements in stream.Z - Type of elements in stream, provided by streamSupplier.R - Result type of combiner function, which fuses a T and a Z object to one instance of R.stream - the stream that's elements are combined with every elements from combineWithstreamSupplier - the elements to be combined with each element from streamcombiner - will be used to combine elements from stream and stream provided by streamSupplier to result values.stream with every element of the stream provided by streamSupplier
combined by using the combiner function.public static <T> Stream<T> operator_plus(Stream<? extends T> first, Stream<? extends T> second)
Stream.concat(first,second).T - Type of resulting concatinated stream. Both input streams must provide T objects, or objects of sub-types of T.first - containing the elements first provided by the resulting Streamsecond - elements provided by the resulting stream after the elements of first.first and secondpublic static <T> Stream<T> iterate(T seed, Predicate<? super T> hasNext, UnaryOperator<T> next)
seed as an initial element. Elements will
only be provided if hasNext returns true when applied to the element. If hasNext
returns false for the initial element the returned Stream will be empty.
The next value(s) provided by the stream will be computed by the previous element using the next
function. The stream will terminate and not provide this element if hasNext does not hold for
this element.T - Type of elements of produced streamseed - first element returned by the stream and seed for following elements by using next.hasNext - before each element is provided (except for the first one)next - operation providing the next elementseed, hasNext, and next.public static <T> Stream<T> iterate(Class<Stream> clazz, T seed, Predicate<? super T> hasNext, UnaryOperator<T> next)
<T>iterate(T, Predicate<? super T>, UnaryOperator<T>).Stream.iterate(0,[it<100],[it+1]) in Xtend, which does not require code changes when
switching to Java 9 to take advantage of the native implementation of this method.T - Type of elements of produced streamclazz - will be ignoredseed - first element returned by the stream and seed for following elements by using next.hasNext - before each element is provided (except for the first one)next - operation providing the next elementseed, hasNext, and next.StreamExtensions#iterate(Object, Predicate, UnaryOperator)Copyright © 2019. All rights reserved.