Class Stream<T>
- java.lang.Object
-
- io.vavr.collection.Stream<T>
-
- Type Parameters:
T
- component type of this Stream
- 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>
- Direct Known Subclasses:
Stream.Cons
,Stream.Empty
public abstract class Stream<T> extends java.lang.Object implements LinearSeq<T>
An immutableStream
is lazy sequence of elements which may be infinitely long. Its immutability makes it suitable for concurrent programming.A
Stream
is composed of ahead
element and a lazy evaluatedtail
Stream
.There are two implementations of the
Stream
interface:Stream.Empty
, which represents the emptyStream
.Stream.Cons
, which represents aStream
containing one or more elements.
Stream
:// factory methods Stream.empty() // = Stream.of() = Nil.instance() Stream.of(x) // = new Cons<>(x, Nil.instance()) Stream.of(Object...) // e.g. Stream.of(1, 2, 3) Stream.ofAll(Iterable) // e.g. Stream.ofAll(List.of(1, 2, 3)) = 1, 2, 3 Stream.ofAll(<primitive array>) // e.g. List.ofAll(1, 2, 3) = 1, 2, 3 // int sequences Stream.from(0) // = 0, 1, 2, 3, ... Stream.range(0, 3) // = 0, 1, 2 Stream.rangeClosed(0, 3) // = 0, 1, 2, 3 // generators Stream.cons(Object, Supplier) // e.g. Stream.cons(current, () -> next(current)); Stream.continually(Supplier) // e.g. Stream.continually(Math::random); Stream.iterate(Object, Function)// e.g. Stream.iterate(1, i -> i * 2);
Stream<Integer> s1 = Stream.of(1); Stream<Integer> s2 = Stream.of(1, 2, 3); // = Stream.of(new Integer[] {1, 2, 3}); Stream<int[]> s3 = Stream.ofAll(1, 2, 3); Stream<List<Integer>> s4 = Stream.ofAll(List.of(1, 2, 3)); Stream<Integer> s5 = Stream.ofAll(1, 2, 3); Stream<Integer> s6 = Stream.ofAll(List.of(1, 2, 3)); // cuckoo's egg Stream<Integer[]> s7 = Stream.<Integer[]> of(new Integer[] {1, 2, 3});
// = Stream(2L, 3L, 5L, 7L, ...) Stream.iterate(2L, PrimeNumbers::nextPrimeFrom) // helpers static long nextPrimeFrom(long num) { return Stream.from(num + 1).find(PrimeNumbers::isPrime).get(); } static boolean isPrime(long num) { return !Stream.rangeClosed(2L, (long) Math.sqrt(num)).exists(d -> num % d == 0); }
- See Also:
- Serialized Form
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
Stream.Cons<T>
Deprecated.will be removed from the public APIstatic class
Stream.Empty<T>
Deprecated.will be removed from the public API
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Method Summary
Modifier and Type Method Description abstract Stream<T>
append(T element)
Appends an element to this.abstract Stream<T>
appendAll(java.lang.Iterable<? extends T> elements)
Appends all given elements to this.Stream<T>
appendSelf(java.util.function.Function<? super Stream<T>,? extends Stream<T>> mapper)
Appends itself to the end of stream withmapper
function.java.util.List<T>
asJava()
Creates an immutableList
view on top of thisSeq
, i.e.Stream<T>
asJava(java.util.function.Consumer<? super java.util.List<T>> action)
Creates an immutableList
view on top of thisSeq
that is passed to the givenaction
.java.util.List<T>
asJavaMutable()
Creates a mutableList
view on top of thisSeq
, i.e.Stream<T>
asJavaMutable(java.util.function.Consumer<? super java.util.List<T>> action)
Creates a mutableList
view on top of thisSeq
that is passed to the givenaction
.<R> Stream<R>
collect(PartialFunction<? super T,? extends R> partialFunction)
Collects all elements that are in the domain of the givenpartialFunction
by mapping the elements to typeR
.static <T> java.util.stream.Collector<T,java.util.ArrayList<T>,Stream<T>>
collector()
Returns aCollector
which may be used in conjunction withStream.collect(java.util.stream.Collector)
to obtain aStream
.Stream<Stream<T>>
combinations()
Returns the union of all combinations from k = 0 to length().Stream<Stream<T>>
combinations(int k)
Returns the k-combination of this traversable, i.e.static <T> Stream<T>
concat(java.lang.Iterable<? extends java.lang.Iterable<? extends T>> iterables)
Lazily creates a Stream in O(1) which traverses along the concatenation of the given iterables.static <T> Stream<T>
concat(java.lang.Iterable<? extends T>... iterables)
Lazily creates a Stream in O(1) which traverses along the concatenation of the given iterables.static <T> Stream<T>
cons(T head, java.util.function.Supplier<? extends Stream<? extends T>> tailSupplier)
Constructs a Stream of a head element and a tail supplier.static <T> Stream<T>
continually(java.util.function.Supplier<? extends T> supplier)
Generates an (theoretically) infinitely long Stream using a value Supplier.static <T> Stream<T>
continually(T t)
Repeats an element infinitely often.Iterator<Stream<T>>
crossProduct(int power)
Calculates the n-ary cartesian power (or cross product or simply product) of this.Stream<T>
cycle()
Repeat the elements of this Stream infinitely.Stream<T>
cycle(int count)
Repeat the elements of this Streamcount
times.Stream<T>
distinct()
Returns a new version of this which contains no duplicates.Stream<T>
distinctBy(java.util.Comparator<? super T> comparator)
Returns a new version of this which contains no duplicates.<U> Stream<T>
distinctBy(java.util.function.Function<? super T,? extends U> keyExtractor)
Returns a new version of this which contains no duplicates.Stream<T>
drop(int n)
Drops the first n elements of this or all elements, if this length < n.Stream<T>
dropRight(int n)
Drops the last n elements of this or all elements, if this length < n.Stream<T>
dropRightUntil(java.util.function.Predicate<? super T> predicate)
Drops elements until the predicate holds for the current element, starting from the end.Stream<T>
dropRightWhile(java.util.function.Predicate<? super T> predicate)
Drops elements while the predicate holds for the current element, starting from the end.Stream<T>
dropUntil(java.util.function.Predicate<? super T> predicate)
Drops elements until the predicate holds for the current element.Stream<T>
dropWhile(java.util.function.Predicate<? super T> predicate)
Drops elements while the predicate holds for the current element.static <T> Stream<T>
empty()
Returns the single instance of Nil.Stream<T>
extend(java.util.function.Function<? super T,? extends T> nextFunction)
Extends (continues) thisStream
with a Stream of values created by applying consecutively providedFunction
to the last element of the original Stream.Stream<T>
extend(java.util.function.Supplier<? extends T> nextSupplier)
Extends (continues) thisStream
with values provided by aSupplier
Stream<T>
extend(T next)
Extends (continues) thisStream
with a constantly repeated value.static <T> Stream<T>
fill(int n, java.util.function.Supplier<? extends T> s)
Returns a Stream containingn
values supplied by a given Suppliers
.static <T> Stream<T>
fill(int n, T element)
Returns a Stream containingn
times the givenelement
Stream<T>
filter(java.util.function.Predicate<? super T> predicate)
Returns a new traversable consisting of all elements which satisfy the given predicate.Stream<T>
filterNot(java.util.function.Predicate<? super T> predicate)
Returns a new traversable consisting of all elements which do not satisfy the given predicate.<U> Stream<U>
flatMap(java.util.function.Function<? super T,? extends java.lang.Iterable<? extends U>> mapper)
FlatMaps this Traversable.static Stream<java.lang.Integer>
from(int value)
Returns an infinitely long Stream ofint
values starting fromfrom
.static Stream<java.lang.Integer>
from(int value, int step)
Returns an infinite long Stream ofint
values starting fromvalue
and spaced bystep
.static Stream<java.lang.Long>
from(long value)
Returns an infinitely long Stream oflong
values starting fromfrom
.static Stream<java.lang.Long>
from(long value, long step)
Returns an infinite long Stream oflong
values starting fromvalue
and spaced bystep
.T
get(int index)
Returns the element at the specified index.<C> Map<C,Stream<T>>
groupBy(java.util.function.Function<? super T,? extends C> classifier)
Groups this elements by classifying the elements.Iterator<Stream<T>>
grouped(int size)
Groups thisTraversable
into fixed size blocks.boolean
hasDefiniteSize()
Checks if this Traversable is known to have a finite size.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.Stream<T>
init()
Dual of Traversable.tail(), returning all elements except the last.Option<Stream<T>>
initOption()
Dual of Traversable.tailOption(), returning all elements except the last asOption
.Stream<T>
insert(int index, T element)
Inserts the given element at the specified index.Stream<T>
insertAll(int index, java.lang.Iterable<? extends T> elements)
Inserts the given elements at the specified index.Stream<T>
intersperse(T element)
Inserts an element between all elements of this Traversable.boolean
isAsync()
AStream
is computed synchronously.boolean
isLazy()
AStream
is computed lazily.boolean
isTraversableAgain()
Checks if this Traversable can be repeatedly traversed.static <T> Stream<T>
iterate(java.util.function.Supplier<? extends Option<? extends T>> supplier)
Generates a (theoretically) infinitely long Stream using a repeatedly invoked supplier that provides aSome
for each next value and aNone
for the end.static <T> Stream<T>
iterate(T seed, java.util.function.Function<? super T,? extends T> f)
Generates a (theoretically) infinitely long Stream using a function to calculate the next value based on the previous.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.Stream<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> Stream<U>
map(java.util.function.Function<? super T,? extends U> mapper)
Maps the elements of thisTraversable
to elements of a new type preserving their order, if any.static <T> Stream<T>
narrow(Stream<? extends T> stream)
Narrows a widenedStream<? extends T>
toStream<T>
by performing a type-safe cast.static <T> Stream<T>
of(T element)
Returns a singletonStream
, i.e.static <T> Stream<T>
of(T... elements)
Creates a Stream of the given elements.static Stream<java.lang.Boolean>
ofAll(boolean... elements)
Creates a Stream from boolean values.static Stream<java.lang.Byte>
ofAll(byte... elements)
Creates a Stream from byte values.static Stream<java.lang.Character>
ofAll(char... elements)
Creates a Stream from char values.static Stream<java.lang.Double>
ofAll(double... elements)
Creates a Stream values double values.static Stream<java.lang.Float>
ofAll(float... elements)
Creates a Stream from float values.static Stream<java.lang.Integer>
ofAll(int... elements)
Creates a Stream from int values.static Stream<java.lang.Long>
ofAll(long... elements)
Creates a Stream from long values.static Stream<java.lang.Short>
ofAll(short... elements)
Creates a Stream from short values.static <T> Stream<T>
ofAll(java.lang.Iterable<? extends T> elements)
Creates a Stream of the given elements.static <T> Stream<T>
ofAll(java.util.stream.Stream<? extends T> javaStream)
Creates a Stream that contains the elements of the givenStream
.Stream<T>
orElse(java.lang.Iterable<? extends T> other)
Returns thisTraversable
if it is nonempty, otherwise return the alternative.Stream<T>
orElse(java.util.function.Supplier<? extends java.lang.Iterable<? extends T>> supplier)
Returns thisTraversable
if it is nonempty, otherwise return the result of evaluating supplier.Stream<T>
padTo(int length, T element)
A copy of this sequence with an element appended until a given target length is reached.Tuple2<Stream<T>,Stream<T>>
partition(java.util.function.Predicate<? super T> predicate)
Creates a partition of thisTraversable
by splitting this elements in two in distinct traversables according to a predicate.Stream<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.Stream<T>
peek(java.util.function.Consumer<? super T> action)
Performs the givenaction
on the first element if this is an eager implementation.Stream<Stream<T>>
permutations()
Computes all unique permutations.Stream<T>
prepend(T element)
Prepends an element to this.Stream<T>
prependAll(java.lang.Iterable<? extends T> elements)
Prepends all given elements to this.static Stream<java.lang.Character>
range(char from, char toExclusive)
static Stream<java.lang.Integer>
range(int from, int toExclusive)
Creates a Stream of int numbers starting fromfrom
, extending totoExclusive - 1
.static Stream<java.lang.Long>
range(long from, long toExclusive)
Creates a Stream of long numbers starting fromfrom
, extending totoExclusive - 1
.static Stream<java.lang.Character>
rangeBy(char from, char toExclusive, int step)
static Stream<java.lang.Double>
rangeBy(double from, double toExclusive, double step)
static Stream<java.lang.Integer>
rangeBy(int from, int toExclusive, int step)
Creates a Stream of int numbers starting fromfrom
, extending totoExclusive - 1
, withstep
.static Stream<java.lang.Long>
rangeBy(long from, long toExclusive, long step)
Creates a Stream of long numbers starting fromfrom
, extending totoExclusive - 1
, withstep
.static Stream<java.lang.Character>
rangeClosed(char from, char toInclusive)
static Stream<java.lang.Integer>
rangeClosed(int from, int toInclusive)
Creates a Stream of int numbers starting fromfrom
, extending totoInclusive
.static Stream<java.lang.Long>
rangeClosed(long from, long toInclusive)
Creates a Stream of long numbers starting fromfrom
, extending totoInclusive
.static Stream<java.lang.Character>
rangeClosedBy(char from, char toInclusive, int step)
static Stream<java.lang.Double>
rangeClosedBy(double from, double toInclusive, double step)
static Stream<java.lang.Integer>
rangeClosedBy(int from, int toInclusive, int step)
Creates a Stream of int numbers starting fromfrom
, extending totoInclusive
, withstep
.static Stream<java.lang.Long>
rangeClosedBy(long from, long toInclusive, long step)
Creates a Stream of long numbers starting fromfrom
, extending totoInclusive
, withstep
.Stream<T>
reject(java.util.function.Predicate<? super T> predicate)
Deprecated.Stream<T>
remove(T element)
Removes the first occurrence of the given element.Stream<T>
removeAll(java.lang.Iterable<? extends T> elements)
Removes all occurrences of the given elements.Stream<T>
removeAll(java.util.function.Predicate<? super T> predicate)
Deprecated.Stream<T>
removeAll(T element)
Removes all occurrences of the given element.Stream<T>
removeAt(int index)
Removes the element at the specified position in this sequence.Stream<T>
removeFirst(java.util.function.Predicate<T> predicate)
Removes the first occurrence that satisfy predicateStream<T>
removeLast(java.util.function.Predicate<T> predicate)
Removes the last occurrence that satisfy predicateStream<T>
replace(T currentElement, T newElement)
Replaces the first occurrence (if exists) of the given currentElement with newElement.Stream<T>
replaceAll(T currentElement, T newElement)
Replaces all occurrences of the given currentElement with newElement.Stream<T>
retainAll(java.lang.Iterable<? extends T> elements)
Keeps all occurrences of the given elements from this.Stream<T>
reverse()
Reverses the order of elements.Stream<T>
rotateLeft(int n)
Circular rotates the elements by the specified distance to the left direction.Stream<T>
rotateRight(int n)
Circular rotates the elements by the specified distance to the right direction.Stream<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> Stream<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> Stream<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.Stream<T>
shuffle()
Randomize the order of the elements in the current sequence.Stream<T>
shuffle(java.util.Random random)
Randomize the order of the elements in the current sequence using the given source of randomness.Stream<T>
slice(int beginIndex, int endIndex)
Returns a Seq that is a slice of this.Iterator<Stream<T>>
slideBy(java.util.function.Function<? super T,?> classifier)
Slides a non-overlapping window of a variable size over thisTraversable
.Iterator<Stream<T>>
sliding(int size)
Slides a window of a specificsize
and step size 1 over thisTraversable
by callingTraversable.sliding(int, int)
.Iterator<Stream<T>>
sliding(int size, int step)
Slides a window of a specificsize
andstep
size over thisTraversable
.<U> Stream<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 givenmapper
.<U extends java.lang.Comparable<? super U>>
Stream<T>sortBy(java.util.function.Function<? super T,? extends U> mapper)
Sorts this elements by comparing the elements in a different domain, using the givenmapper
.Stream<T>
sorted()
Sorts this elements according to their natural order.Stream<T>
sorted(java.util.Comparator<? super T> comparator)
Sorts this elements according to the providedComparator
.Tuple2<Stream<T>,Stream<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 givenpredicate
and the second element is the remainder.Tuple2<Stream<T>,Stream<T>>
splitAt(int n)
Splits a Seq at the specified index.Tuple2<Stream<T>,Stream<T>>
splitAt(java.util.function.Predicate<? super T> predicate)
Splits a sequence at the first element which satisfies thePredicate
, e.g.Tuple2<Stream<T>,Stream<T>>
splitAtInclusive(java.util.function.Predicate<? super T> predicate)
Splits a sequence at the first element which satisfies thePredicate
, e.g.java.lang.String
stringPrefix()
Returns the name of this Value type, which is used by toString().Stream<T>
subSequence(int beginIndex)
Returns a Seq that is a subsequence of this.Stream<T>
subSequence(int beginIndex, int endIndex)
Returns a Seq that is a subsequence of this.static <T> Stream<T>
tabulate(int n, java.util.function.Function<? super java.lang.Integer,? extends T> f)
Returns a Stream containingn
values of a given Functionf
over a range of integer values from 0 ton - 1
.abstract Stream<T>
tail()
Drops the first element of a non-empty Traversable.Option<Stream<T>>
tailOption()
Drops the first element of a non-empty Traversable and returns anOption
.Stream<T>
take(int n)
Takes the first n elements of this or all elements, if this length < n.Stream<T>
takeRight(int n)
Takes the last n elements of this or all elements, if this length < n.Stream<T>
takeRightUntil(java.util.function.Predicate<? super T> predicate)
Takes elements until the predicate holds for the current element, starting from the end.Stream<T>
takeRightWhile(java.util.function.Predicate<? super T> predicate)
Takes elements while the predicate holds for the current element, starting from the end.Stream<T>
takeUntil(java.util.function.Predicate<? super T> predicate)
Takes elements until the predicate holds for the current element.Stream<T>
takeWhile(java.util.function.Predicate<? super T> predicate)
Takes elements while the predicate holds for the current element.<U> U
transform(java.util.function.Function<? super Stream<T>,? extends U> f)
Transforms thisStream
.static <T> Stream<Stream<T>>
transpose(Stream<Stream<T>> matrix)
Transposes the rows and columns of aStream
matrix.static <T> Stream<T>
unfold(T seed, java.util.function.Function<? super T,Option<Tuple2<? extends T,? extends T>>> f)
Creates a Stream from a seed value and a function.static <T,U>
Stream<U>unfoldLeft(T seed, java.util.function.Function<? super T,Option<Tuple2<? extends T,? extends U>>> f)
Creates a Stream from a seed value and a function.static <T,U>
Stream<U>unfoldRight(T seed, java.util.function.Function<? super T,Option<Tuple2<? extends U,? extends T>>> f)
Creates a Stream from a seed value and a function.<T1,T2>
Tuple2<Stream<T1>,Stream<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<Stream<T1>,Stream<T2>,Stream<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.Stream<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.Stream<T>
update(int index, T element)
Updates the given element at the specified index.<U> Stream<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> Stream<Tuple2<T,U>>
zipAll(java.lang.Iterable<? extends U> iterable, T thisElem, U thatElem)
Returns a traversable formed from this traversable and another Iterable by combining corresponding elements in pairs.<U,R>
Stream<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.Stream<Tuple2<T,java.lang.Integer>>
zipWithIndex()
Zips this traversable with its indices.<U> Stream<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, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Methods inherited from interface io.vavr.Function1
andThen, arity, compose, curried, isMemoized, memoized, partial, reversed, tupled
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Methods inherited from interface io.vavr.collection.LinearSeq
asPartialFunction, indexOfSlice, indexWhere, isDefinedAt, lastIndexOfSlice, lastIndexWhere, reverseIterator, search, search, segmentLength
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Methods inherited from interface io.vavr.collection.Seq
apply, containsSlice, crossProduct, crossProduct, endsWith, foldRight, indexOf, indexOfOption, indexOfOption, indexOfSlice, indexOfSliceOption, indexOfSliceOption, indexWhere, indexWhereOption, indexWhereOption, isSequential, iterator, lastIndexOf, lastIndexOfOption, lastIndexOfOption, lastIndexOfSlice, lastIndexOfSliceOption, lastIndexOfSliceOption, lastIndexWhere, lastIndexWhereOption, lastIndexWhereOption, lift, prefixLength, startsWith, startsWith, withDefault, withDefaultValue
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Methods inherited from interface io.vavr.collection.Traversable
arrangeBy, average, containsAll, count, equals, existsUnique, find, findLast, fold, foldLeft, forEachWithIndex, get, hashCode, head, headOption, isDistinct, isEmpty, isOrdered, isSingleValued, iterator, lastOption, max, maxBy, maxBy, min, minBy, minBy, mkCharSeq, mkCharSeq, mkCharSeq, mkString, mkString, mkString, nonEmpty, product, reduce, reduceLeft, reduceLeftOption, reduceOption, reduceRight, reduceRightOption, single, singleOption, size, spliterator, sum
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Methods inherited from interface io.vavr.Value
collect, collect, contains, corresponds, eq, exists, forAll, forEach, getOrElse, getOrElse, getOrElseThrow, getOrElseTry, getOrNull, out, out, stderr, stdout, toArray, toCharSeq, toCompletableFuture, toEither, toEither, toInvalid, toInvalid, toJavaArray, toJavaArray, toJavaArray, toJavaCollection, toJavaList, toJavaList, toJavaMap, toJavaMap, toJavaMap, toJavaOptional, toJavaParallelStream, toJavaSet, toJavaSet, toJavaStream, toLeft, toLeft, toLinkedMap, toLinkedMap, toLinkedSet, toList, toMap, toMap, toOption, toPriorityQueue, toPriorityQueue, toQueue, toRight, toRight, toSet, toSortedMap, toSortedMap, toSortedMap, toSortedMap, toSortedSet, toSortedSet, toStream, toString, toTree, toTree, toTry, toTry, toValid, toValid, toValidation, toValidation, toVector
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Method Detail
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collector
public static <T> java.util.stream.Collector<T,java.util.ArrayList<T>,Stream<T>> collector()
Returns aCollector
which may be used in conjunction withStream.collect(java.util.stream.Collector)
to obtain aStream
.- Type Parameters:
T
- Component type of the Stream.- Returns:
- A io.vavr.collection.Stream Collector.
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concat
@SafeVarargs public static <T> Stream<T> concat(java.lang.Iterable<? extends T>... iterables)
Lazily creates a Stream in O(1) which traverses along the concatenation of the given iterables.- Type Parameters:
T
- Component type.- Parameters:
iterables
- The iterables- Returns:
- A new
Stream
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concat
public static <T> Stream<T> concat(java.lang.Iterable<? extends java.lang.Iterable<? extends T>> iterables)
Lazily creates a Stream in O(1) which traverses along the concatenation of the given iterables.- Type Parameters:
T
- Component type.- Parameters:
iterables
- The iterable of iterables- Returns:
- A new
Stream
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from
public static Stream<java.lang.Integer> from(int value)
Returns an infinitely long Stream ofint
values starting fromfrom
.The
Stream
extends toInteger.MIN_VALUE
when passingInteger.MAX_VALUE
.- Parameters:
value
- a start int value- Returns:
- a new Stream of int values starting from
from
-
from
public static Stream<java.lang.Integer> from(int value, int step)
Returns an infinite long Stream ofint
values starting fromvalue
and spaced bystep
.The
Stream
extends toInteger.MIN_VALUE
when passingInteger.MAX_VALUE
.- Parameters:
value
- a start int valuestep
- the step by which to advance on each next value- Returns:
- a new
Stream
of int values starting fromfrom
-
from
public static Stream<java.lang.Long> from(long value)
Returns an infinitely long Stream oflong
values starting fromfrom
.The
Stream
extends toInteger.MIN_VALUE
when passingLong.MAX_VALUE
.- Parameters:
value
- a start long value- Returns:
- a new Stream of long values starting from
from
-
from
public static Stream<java.lang.Long> from(long value, long step)
Returns an infinite long Stream oflong
values starting fromvalue
and spaced bystep
.The
Stream
extends toLong.MIN_VALUE
when passingLong.MAX_VALUE
.- Parameters:
value
- a start long valuestep
- the step by which to advance on each next value- Returns:
- a new
Stream
of long values starting fromfrom
-
continually
public static <T> Stream<T> continually(java.util.function.Supplier<? extends T> supplier)
Generates an (theoretically) infinitely long Stream using a value Supplier.- Type Parameters:
T
- value type- Parameters:
supplier
- A Supplier of Stream values- Returns:
- A new Stream
-
iterate
public static <T> Stream<T> iterate(T seed, java.util.function.Function<? super T,? extends T> f)
Generates a (theoretically) infinitely long Stream using a function to calculate the next value based on the previous.- Type Parameters:
T
- value type- Parameters:
seed
- The first value in the Streamf
- A function to calculate the next value based on the previous- Returns:
- A new Stream
-
iterate
public static <T> Stream<T> iterate(java.util.function.Supplier<? extends Option<? extends T>> supplier)
Generates a (theoretically) infinitely long Stream using a repeatedly invoked supplier that provides aSome
for each next value and aNone
for the end. TheSupplier
will be invoked only that many times until it returnsNone
, and repeated iteration over the stream will produce the same values in the same order, without any further invocations to theSupplier
.- Type Parameters:
T
- value type- Parameters:
supplier
- A Supplier of iterator values- Returns:
- A new Stream
-
cons
public static <T> Stream<T> cons(T head, java.util.function.Supplier<? extends Stream<? extends T>> tailSupplier)
Constructs a Stream of a head element and a tail supplier.- Type Parameters:
T
- value type- Parameters:
head
- The head element of the StreamtailSupplier
- A supplier of the tail values. To end the stream, returnempty()
.- Returns:
- A new Stream
-
empty
public static <T> Stream<T> empty()
Returns the single instance of Nil. Convenience method forNil.instance()
.Note: this method intentionally returns type
Stream
and notNil
. This comes handy when folding. If you explicitly need typeNil
use Stream.Empty.instance().- Type Parameters:
T
- Component type of Nil, determined by type inference in the particular context.- Returns:
- The empty list.
-
narrow
public static <T> Stream<T> narrow(Stream<? extends T> stream)
Narrows a widenedStream<? extends T>
toStream<T>
by performing a type-safe cast. This is eligible because immutable/read-only collections are covariant.- Type Parameters:
T
- Component type of theStream
.- Parameters:
stream
- AStream
.- Returns:
- the given
stream
instance as narrowed typeStream<T>
.
-
of
public static <T> Stream<T> of(T element)
Returns a singletonStream
, i.e. aStream
of one element.- Type Parameters:
T
- The component type- Parameters:
element
- An element.- Returns:
- A new Stream instance containing the given element
-
of
@SafeVarargs public static <T> Stream<T> of(T... elements)
Creates a Stream of the given elements.Stream.of(1, 2, 3, 4) = Nil.instance().prepend(4).prepend(3).prepend(2).prepend(1) = new Cons(1, new Cons(2, new Cons(3, new Cons(4, Nil.instance()))))
- Type Parameters:
T
- Component type of the Stream.- Parameters:
elements
- Zero or more elements.- Returns:
- A list containing the given elements in the same order.
-
tabulate
public static <T> Stream<T> tabulate(int n, java.util.function.Function<? super java.lang.Integer,? extends T> f)
Returns a Stream containingn
values of a given Functionf
over a range of integer values from 0 ton - 1
.- Type Parameters:
T
- Component type of the Stream- Parameters:
n
- The number of elements in the Streamf
- The Function computing element values- Returns:
- A Stream consisting of elements
f(0),f(1), ..., f(n - 1)
- Throws:
java.lang.NullPointerException
- iff
is null
-
fill
public static <T> Stream<T> fill(int n, java.util.function.Supplier<? extends T> s)
Returns a Stream containingn
values supplied by a given Suppliers
.- Type Parameters:
T
- Component type of the Stream- Parameters:
n
- The number of elements in the Streams
- The Supplier computing element values- Returns:
- A Stream of size
n
, where each element contains the result supplied bys
. - Throws:
java.lang.NullPointerException
- ifs
is null
-
fill
public static <T> Stream<T> fill(int n, T element)
Returns a Stream containingn
times the givenelement
- Type Parameters:
T
- Component type of the Stream- Parameters:
n
- The number of elements in the Streamelement
- The element- Returns:
- A Stream of size
n
, where each element is the givenelement
.
-
ofAll
public static <T> Stream<T> ofAll(java.lang.Iterable<? extends T> elements)
Creates a Stream of the given elements.- Type Parameters:
T
- Component type of the Stream.- Parameters:
elements
- An Iterable of elements.- Returns:
- A Stream containing the given elements in the same order.
-
ofAll
public static <T> Stream<T> ofAll(java.util.stream.Stream<? extends T> javaStream)
Creates a Stream that contains the elements of the givenStream
.- Type Parameters:
T
- Component type of the Stream.- Parameters:
javaStream
- AStream
- Returns:
- A Stream containing the given elements in the same order.
-
ofAll
public static Stream<java.lang.Boolean> ofAll(boolean... elements)
Creates a Stream from boolean values.- Parameters:
elements
- boolean values- Returns:
- A new Stream of Boolean values
- Throws:
java.lang.NullPointerException
- if elements is null
-
ofAll
public static Stream<java.lang.Byte> ofAll(byte... elements)
Creates a Stream from byte values.- Parameters:
elements
- byte values- Returns:
- A new Stream of Byte values
- Throws:
java.lang.NullPointerException
- if elements is null
-
ofAll
public static Stream<java.lang.Character> ofAll(char... elements)
Creates a Stream from char values.- Parameters:
elements
- char values- Returns:
- A new Stream of Character values
- Throws:
java.lang.NullPointerException
- if elements is null
-
ofAll
public static Stream<java.lang.Double> ofAll(double... elements)
Creates a Stream values double values.- Parameters:
elements
- double values- Returns:
- A new Stream of Double values
- Throws:
java.lang.NullPointerException
- if elements is null
-
ofAll
public static Stream<java.lang.Float> ofAll(float... elements)
Creates a Stream from float values.- Parameters:
elements
- float values- Returns:
- A new Stream of Float values
- Throws:
java.lang.NullPointerException
- if elements is null
-
ofAll
public static Stream<java.lang.Integer> ofAll(int... elements)
Creates a Stream from int values.- Parameters:
elements
- int values- Returns:
- A new Stream of Integer values
- Throws:
java.lang.NullPointerException
- if elements is null
-
ofAll
public static Stream<java.lang.Long> ofAll(long... elements)
Creates a Stream from long values.- Parameters:
elements
- long values- Returns:
- A new Stream of Long values
- Throws:
java.lang.NullPointerException
- if elements is null
-
ofAll
public static Stream<java.lang.Short> ofAll(short... elements)
Creates a Stream from short values.- Parameters:
elements
- short values- Returns:
- A new Stream of Short values
- Throws:
java.lang.NullPointerException
- if elements is null
-
range
public static Stream<java.lang.Character> range(char from, char toExclusive)
-
rangeBy
public static Stream<java.lang.Character> rangeBy(char from, char toExclusive, int step)
-
rangeBy
@GwtIncompatible public static Stream<java.lang.Double> rangeBy(double from, double toExclusive, double step)
-
range
public static Stream<java.lang.Integer> range(int from, int toExclusive)
Creates a Stream of int numbers starting fromfrom
, extending totoExclusive - 1
.Examples:
Stream.range(0, 0) // = Stream() Stream.range(2, 0) // = Stream() Stream.range(-2, 2) // = Stream(-2, -1, 0, 1)
- Parameters:
from
- the first numbertoExclusive
- the last number + 1- Returns:
- a range of int values as specified or
Nil
iffrom >= toExclusive
-
rangeBy
public static Stream<java.lang.Integer> rangeBy(int from, int toExclusive, int step)
Creates a Stream of int numbers starting fromfrom
, extending totoExclusive - 1
, withstep
.Examples:
Stream.rangeBy(1, 3, 1) // = Stream(1, 2) Stream.rangeBy(1, 4, 2) // = Stream(1, 3) Stream.rangeBy(4, 1, -2) // = Stream(4, 2) Stream.rangeBy(4, 1, 2) // = Stream()
- Parameters:
from
- the first numbertoExclusive
- the last number + 1step
- the step- Returns:
- a range of long values as specified or
Nil
if
from >= toInclusive
andstep > 0
or
from <= toInclusive
andstep < 0
- Throws:
java.lang.IllegalArgumentException
- ifstep
is zero
-
range
public static Stream<java.lang.Long> range(long from, long toExclusive)
Creates a Stream of long numbers starting fromfrom
, extending totoExclusive - 1
.Examples:
Stream.range(0L, 0L) // = Stream() Stream.range(2L, 0L) // = Stream() Stream.range(-2L, 2L) // = Stream(-2L, -1L, 0L, 1L)
- Parameters:
from
- the first numbertoExclusive
- the last number + 1- Returns:
- a range of long values as specified or
Nil
iffrom >= toExclusive
-
rangeBy
public static Stream<java.lang.Long> rangeBy(long from, long toExclusive, long step)
Creates a Stream of long numbers starting fromfrom
, extending totoExclusive - 1
, withstep
.Examples:
Stream.rangeBy(1L, 3L, 1L) // = Stream(1L, 2L) Stream.rangeBy(1L, 4L, 2L) // = Stream(1L, 3L) Stream.rangeBy(4L, 1L, -2L) // = Stream(4L, 2L) Stream.rangeBy(4L, 1L, 2L) // = Stream()
- Parameters:
from
- the first numbertoExclusive
- the last number + 1step
- the step- Returns:
- a range of long values as specified or
Nil
if
from >= toInclusive
andstep > 0
or
from <= toInclusive
andstep < 0
- Throws:
java.lang.IllegalArgumentException
- ifstep
is zero
-
rangeClosed
public static Stream<java.lang.Character> rangeClosed(char from, char toInclusive)
-
rangeClosedBy
public static Stream<java.lang.Character> rangeClosedBy(char from, char toInclusive, int step)
-
rangeClosedBy
@GwtIncompatible public static Stream<java.lang.Double> rangeClosedBy(double from, double toInclusive, double step)
-
rangeClosed
public static Stream<java.lang.Integer> rangeClosed(int from, int toInclusive)
Creates a Stream of int numbers starting fromfrom
, extending totoInclusive
.Examples:
Stream.rangeClosed(0, 0) // = Stream(0) Stream.rangeClosed(2, 0) // = Stream() Stream.rangeClosed(-2, 2) // = Stream(-2, -1, 0, 1, 2)
- Parameters:
from
- the first numbertoInclusive
- the last number- Returns:
- a range of int values as specified or
Nil
iffrom > toInclusive
-
rangeClosedBy
public static Stream<java.lang.Integer> rangeClosedBy(int from, int toInclusive, int step)
Creates a Stream of int numbers starting fromfrom
, extending totoInclusive
, withstep
.Examples:
Stream.rangeClosedBy(1, 3, 1) // = Stream(1, 2, 3) Stream.rangeClosedBy(1, 4, 2) // = Stream(1, 3) Stream.rangeClosedBy(4, 1, -2) // = Stream(4, 2) Stream.rangeClosedBy(4, 1, 2) // = Stream()
- Parameters:
from
- the first numbertoInclusive
- the last numberstep
- the step- Returns:
- a range of int values as specified or
Nil
if
from > toInclusive
andstep > 0
or
from < toInclusive
andstep < 0
- Throws:
java.lang.IllegalArgumentException
- ifstep
is zero
-
rangeClosed
public static Stream<java.lang.Long> rangeClosed(long from, long toInclusive)
Creates a Stream of long numbers starting fromfrom
, extending totoInclusive
.Examples:
Stream.rangeClosed(0L, 0L) // = Stream(0L) Stream.rangeClosed(2L, 0L) // = Stream() Stream.rangeClosed(-2L, 2L) // = Stream(-2L, -1L, 0L, 1L, 2L)
- Parameters:
from
- the first numbertoInclusive
- the last number- Returns:
- a range of long values as specified or
Nil
iffrom > toInclusive
-
rangeClosedBy
public static Stream<java.lang.Long> rangeClosedBy(long from, long toInclusive, long step)
Creates a Stream of long numbers starting fromfrom
, extending totoInclusive
, withstep
.Examples:
Stream.rangeClosedBy(1L, 3L, 1L) // = Stream(1L, 2L, 3L) Stream.rangeClosedBy(1L, 4L, 2L) // = Stream(1L, 3L) Stream.rangeClosedBy(4L, 1L, -2L) // = Stream(4L, 2L) Stream.rangeClosedBy(4L, 1L, 2L) // = Stream()
- Parameters:
from
- the first numbertoInclusive
- the last numberstep
- the step- Returns:
- a range of int values as specified or
Nil
if
from > toInclusive
andstep > 0
or
from < toInclusive
andstep < 0
- Throws:
java.lang.IllegalArgumentException
- ifstep
is zero
-
transpose
public static <T> Stream<Stream<T>> transpose(Stream<Stream<T>> matrix)
Transposes the rows and columns of aStream
matrix.- Type Parameters:
T
- matrix element type- Parameters:
matrix
- to be transposed.- Returns:
- a transposed
Stream
matrix. - Throws:
java.lang.IllegalArgumentException
- if the row lengths ofmatrix
differ.ex:
Stream.transpose(Stream(Stream(1,2,3), Stream(4,5,6))) → Stream(Stream(1,4), Stream(2,5), Stream(3,6))
-
unfoldRight
public static <T,U> Stream<U> unfoldRight(T seed, java.util.function.Function<? super T,Option<Tuple2<? extends U,? extends T>>> f)
Creates a Stream from a seed value and a function. The function takes the seed at first. The function should returnNone
when it's done generating the Stream, otherwiseSome
Tuple
of the element for the next call and the value to add to the resulting Stream.Example:
Stream.unfoldRight(10, x -> x == 0 ? Option.none() : Option.of(new Tuple2<>(x, x-1))); // Stream(10, 9, 8, 7, 6, 5, 4, 3, 2, 1))
- Type Parameters:
T
- type of seedsU
- type of unfolded values- Parameters:
seed
- the start value for the iterationf
- the function to get the next step of the iteration- Returns:
- a Stream with the values built up by the iteration
- Throws:
java.lang.NullPointerException
- iff
is null
-
unfoldLeft
public static <T,U> Stream<U> unfoldLeft(T seed, java.util.function.Function<? super T,Option<Tuple2<? extends T,? extends U>>> f)
Creates a Stream from a seed value and a function. The function takes the seed at first. The function should returnNone
when it's done generating the Stream, otherwiseSome
Tuple
of the value to add to the resulting Stream and the element for the next call.Example:
Stream.unfoldLeft(10, x -> x == 0 ? Option.none() : Option.of(new Tuple2<>(x-1, x))); // Stream(1, 2, 3, 4, 5, 6, 7, 8, 9, 10))
- Type Parameters:
T
- type of seedsU
- type of unfolded values- Parameters:
seed
- the start value for the iterationf
- the function to get the next step of the iteration- Returns:
- a Stream with the values built up by the iteration
- Throws:
java.lang.NullPointerException
- iff
is null
-
unfold
public static <T> Stream<T> unfold(T seed, java.util.function.Function<? super T,Option<Tuple2<? extends T,? extends T>>> f)
Creates a Stream from a seed value and a function. The function takes the seed at first. The function should returnNone
when it's done generating the Stream, otherwiseSome
Tuple
of the value to add to the resulting Stream and the element for the next call.Example:
Stream.unfold(10, x -> x == 0 ? Option.none() : Option.of(new Tuple2<>(x-1, x))); // Stream(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 iterationf
- the function to get the next step of the iteration- Returns:
- a Stream with the values built up by the iteration
- Throws:
java.lang.NullPointerException
- iff
is null
-
continually
public static <T> Stream<T> continually(T t)
Repeats an element infinitely often.- Type Parameters:
T
- Element type- Parameters:
t
- An element- Returns:
- A new Stream containing infinite
t
's.
-
append
public abstract Stream<T> append(T element)
Description copied from interface:Seq
Appends an element to this.
-
appendAll
public abstract Stream<T> appendAll(java.lang.Iterable<? extends T> elements)
Description copied from interface:Seq
Appends all given elements to this.
-
appendSelf
public final Stream<T> appendSelf(java.util.function.Function<? super Stream<T>,? extends Stream<T>> mapper)
Appends itself to the end of stream withmapper
function.Example:
Well known Scala code for Fibonacci infinite sequence
val fibs:Stream[Int] = 0 #:: 1 #:: (fibs zip fibs.tail).map{ t => t._1 + t._2 }
Stream.of(0, 1).appendSelf(self -> self.zip(self.tail()).map(t -> t._1 + t._2));
- Parameters:
mapper
- an mapper- Returns:
- a new Stream
-
asJava
@GwtIncompatible public final java.util.List<T> asJava()
Description copied from interface:Seq
Creates an immutableList
view on top of thisSeq
, i.e. calling mutators will result inUnsupportedOperationException
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.
java.util.List
view throwsUnsupportedOperationException
before checking method arguments. Java does handle this case inconsistently.
-
asJava
@GwtIncompatible public final Stream<T> asJava(java.util.function.Consumer<? super java.util.List<T>> action)
Description copied from interface:Seq
Creates an immutableList
view on top of thisSeq
that is passed to the givenaction
.
-
asJavaMutable
@GwtIncompatible public final java.util.List<T> asJavaMutable()
Description copied from interface:Seq
Creates a mutableList
view on top of thisSeq
, i.e. all mutator methods of theList
are implemented.- Specified by:
asJavaMutable
in interfaceSeq<T>
- Returns:
- A new mutable
Collection
view on thisTraversable
. - See Also:
Seq.asJava()
-
asJavaMutable
@GwtIncompatible public final Stream<T> asJavaMutable(java.util.function.Consumer<? super java.util.List<T>> action)
Description copied from interface:Seq
Creates a mutableList
view on top of thisSeq
that is passed to the givenaction
.- Specified by:
asJavaMutable
in interfaceLinearSeq<T>
- Specified by:
asJavaMutable
in interfaceSeq<T>
- Parameters:
action
- A side-effecting unit of work that operates on a mutablejava.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 thejava.util.List
view. - See Also:
Seq.asJavaMutable()
-
collect
public final <R> Stream<R> collect(PartialFunction<? super T,? extends R> partialFunction)
Description copied from interface:Traversable
Collects all elements that are in the domain of the givenpartialFunction
by mapping the elements to typeR
.More specifically, for each of this elements in iteration order first it is checked
If the elements makes it through that filter, the mapped instance is added to the result collectionpartialFunction.isDefinedAt(element)
Note:If thisR newElement = partialFunction.apply(element)
Traversable
is ordered (i.e. extendsOrdered
, the caller ofcollect
has to ensure that the elements are comparable (i.e. extendComparable
).- Specified by:
collect
in interfaceLinearSeq<T>
- Specified by:
collect
in interfaceSeq<T>
- Specified by:
collect
in interfaceTraversable<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 typeR
-
combinations
public final Stream<Stream<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 interfaceLinearSeq<T>
- Specified by:
combinations
in interfaceSeq<T>
- Returns:
- the combinations of this
-
combinations
public final Stream<Stream<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 interfaceLinearSeq<T>
- Specified by:
combinations
in interfaceSeq<T>
- Parameters:
k
- Size of subsets- Returns:
- the k-combination of this elements
- See Also:
- Combination
-
crossProduct
public final Iterator<Stream<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 interfaceLinearSeq<T>
- Specified by:
crossProduct
in interfaceSeq<T>
- Parameters:
power
- the number of cartesian multiplications- Returns:
- A new Iterator representing the n-ary cartesian power of this
-
cycle
public final Stream<T> cycle()
Repeat the elements of this Stream infinitely.Example:
// = 1, 2, 3, 1, 2, 3, 1, 2, 3, ... Stream.of(1, 2, 3).cycle();
- Returns:
- A new Stream containing this elements cycled.
-
cycle
public final Stream<T> cycle(int count)
Repeat the elements of this Streamcount
times.Example:
// = empty Stream.of(1, 2, 3).cycle(0); // = 1, 2, 3 Stream.of(1, 2, 3).cycle(1); // = 1, 2, 3, 1, 2, 3, 1, 2, 3 Stream.of(1, 2, 3).cycle(3);
- Parameters:
count
- the number of cycles to be performed- Returns:
- A new Stream containing this elements cycled
count
times.
-
distinct
public final Stream<T> distinct()
Description copied from interface:Traversable
Returns a new version of this which contains no duplicates. Elements are compared usingequals
.
-
distinctBy
public final Stream<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 givencomparator
.- Specified by:
distinctBy
in interfaceLinearSeq<T>
- Specified by:
distinctBy
in interfaceSeq<T>
- Specified by:
distinctBy
in interfaceTraversable<T>
- Parameters:
comparator
- A comparator- Returns:
- a new
Traversable
containing this elements without duplicates
-
distinctBy
public final <U> Stream<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 usingequals
.The elements of the result are determined in the order of their occurrence - first match wins.
- Specified by:
distinctBy
in interfaceLinearSeq<T>
- Specified by:
distinctBy
in interfaceSeq<T>
- Specified by:
distinctBy
in interfaceTraversable<T>
- Type Parameters:
U
- key type- Parameters:
keyExtractor
- A key extractor- Returns:
- a new
Traversable
containing this elements without duplicates
-
drop
public final Stream<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 interfaceLinearSeq<T>
- Specified by:
drop
in interfaceSeq<T>
- Specified by:
drop
in interfaceTraversable<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.
-
dropUntil
public final Stream<T> 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 interfaceLinearSeq<T>
- Specified by:
dropUntil
in interfaceSeq<T>
- Specified by:
dropUntil
in interfaceTraversable<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.
-
dropWhile
public final Stream<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 interfaceLinearSeq<T>
- Specified by:
dropWhile
in interfaceSeq<T>
- Specified by:
dropWhile
in interfaceTraversable<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 final Stream<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 interfaceLinearSeq<T>
- Specified by:
dropRight
in interfaceSeq<T>
- Specified by:
dropRight
in interfaceTraversable<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 final Stream<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 interfaceLinearSeq<T>
- Specified by:
dropRightUntil
in interfaceSeq<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 final Stream<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 interfaceLinearSeq<T>
- Specified by:
dropRightWhile
in interfaceSeq<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 final Stream<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.
-
filterNot
public final Stream<T> 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()
-
reject
@Deprecated public final Stream<T> 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()
-
flatMap
public final <U> Stream<U> flatMap(java.util.function.Function<? super T,? extends java.lang.Iterable<? extends U>> mapper)
Description copied from interface:Traversable
FlatMaps this Traversable.
-
get
public final T get(int index)
Description copied from interface:Seq
Returns the element at the specified index.
-
groupBy
public final <C> Map<C,Stream<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 interfaceLinearSeq<T>
- Specified by:
groupBy
in interfaceSeq<T>
- Specified by:
groupBy
in interfaceTraversable<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 final Iterator<Stream<T>> grouped(int size)
Description copied from interface:Traversable
Groups thisTraversable
into fixed size blocks.Let length be the length of this Iterable. Then grouped is defined as follows:
- If
this.isEmpty()
, the resultingIterator
is empty. - If
size <= length
, the resultingIterator
will containlength / size
blocks of sizesize
and maybe a non-empty block of sizelength % size
, if there are remaining elements. - If
size > length
, the resultingIterator
will contain one block of sizelength
.
[].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]]
grouped(int)
is a special case of Traversable.sliding(int, int), i.e.grouped(size)
is the same assliding(size, size)
. - If
-
hasDefiniteSize
public final 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 interfaceTraversable<T>
- Returns:
- true, if this Traversable is known to have a finite size, false otherwise.
-
indexOf
public final 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.
-
init
public final Stream<T> init()
Description copied from interface:Traversable
Dual of Traversable.tail(), returning all elements except the last.
-
initOption
public final Option<Stream<T>> initOption()
Description copied from interface:Traversable
Dual of Traversable.tailOption(), returning all elements except the last asOption
.- Specified by:
initOption
in interfaceLinearSeq<T>
- Specified by:
initOption
in interfaceSeq<T>
- Specified by:
initOption
in interfaceTraversable<T>
- Returns:
Some(traversable)
orNone
if this is empty.
-
insert
public final Stream<T> insert(int index, T element)
Description copied from interface:Seq
Inserts the given element at the specified index.
-
insertAll
public final Stream<T> insertAll(int index, java.lang.Iterable<? extends T> elements)
Description copied from interface:Seq
Inserts the given elements at the specified index.
-
intersperse
public final Stream<T> intersperse(T element)
Description copied from interface:Seq
Inserts an element between all elements of this Traversable.- Specified by:
intersperse
in interfaceLinearSeq<T>
- Specified by:
intersperse
in interfaceSeq<T>
- Parameters:
element
- An element.- Returns:
- an interspersed version of this
-
isAsync
public final boolean isAsync()
AStream
is computed synchronously.
-
isLazy
public final boolean isLazy()
AStream
is computed lazily.
-
isTraversableAgain
public final 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 interfaceTraversable<T>
- Returns:
- true, if this Traversable is known to be traversable repeatedly, false otherwise.
-
last
public final T last()
Description copied from interface:Traversable
Dual of Traversable.head(), returning the last element.- Specified by:
last
in interfaceTraversable<T>
- Returns:
- the last element.
-
lastIndexOf
public final 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 interfaceSeq<T>
- Parameters:
element
- an elementend
- the end index- Returns:
- the index of the last occurrence of the given element
-
length
public final int length()
Description copied from interface:Traversable
Computes the number of elements of this Traversable.Same as
Traversable.size()
.- Specified by:
length
in interfaceTraversable<T>
- Returns:
- the number of elements
-
map
public final <U> Stream<U> map(java.util.function.Function<? super T,? extends U> mapper)
Description copied from interface:Traversable
Maps the elements of thisTraversable
to elements of a new type preserving their order, if any.
-
padTo
public final Stream<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 interfaceLinearSeq<T>
- Specified by:
padTo
in interfaceSeq<T>
- Parameters:
length
- the target lengthelement
- 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 leastlength
.
-
leftPadTo
public final Stream<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 interfaceSeq<T>
- Parameters:
length
- the target lengthelement
- 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 leastlength
.
-
orElse
public final Stream<T> orElse(java.lang.Iterable<? extends T> other)
Description copied from interface:Traversable
Returns thisTraversable
if it is nonempty, otherwise return the alternative.
-
orElse
public final Stream<T> orElse(java.util.function.Supplier<? extends java.lang.Iterable<? extends T>> supplier)
Description copied from interface:Traversable
Returns thisTraversable
if it is nonempty, otherwise return the result of evaluating supplier.
-
patch
public final Stream<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.
-
partition
public final Tuple2<Stream<T>,Stream<T>> partition(java.util.function.Predicate<? super T> predicate)
Description copied from interface:Traversable
Creates a partition of thisTraversable
by splitting this elements in two in distinct traversables according to a predicate.- Specified by:
partition
in interfaceLinearSeq<T>
- Specified by:
partition
in interfaceSeq<T>
- Specified by:
partition
in interfaceTraversable<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 givenpredicate
, the secondTraversable
contains all elements that don't. The original order of elements is preserved.
-
peek
public final Stream<T> peek(java.util.function.Consumer<? super T> action)
Description copied from interface:Value
Performs the givenaction
on the first element if this is an eager implementation. Performs the givenaction
on all elements (the first immediately, successive deferred), if this is a lazy implementation.
-
permutations
public final Stream<Stream<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 interfaceLinearSeq<T>
- Specified by:
permutations
in interfaceSeq<T>
- Returns:
- this unique permutations
-
prepend
public final Stream<T> prepend(T element)
Description copied from interface:Seq
Prepends an element to this.
-
prependAll
public final Stream<T> prependAll(java.lang.Iterable<? extends T> elements)
Description copied from interface:Seq
Prepends all given elements to this.- Specified by:
prependAll
in interfaceLinearSeq<T>
- Specified by:
prependAll
in interfaceSeq<T>
- Parameters:
elements
- An Iterable of elements- Returns:
- A new Seq containing the given elements prepended to this elements
-
remove
public final Stream<T> remove(T element)
Description copied from interface:Seq
Removes the first occurrence of the given element.
-
removeFirst
public final Stream<T> removeFirst(java.util.function.Predicate<T> predicate)
Description copied from interface:Seq
Removes the first occurrence that satisfy predicate- Specified by:
removeFirst
in interfaceLinearSeq<T>
- Specified by:
removeFirst
in interfaceSeq<T>
- Parameters:
predicate
- an predicate- Returns:
- a new Seq
-
removeLast
public final Stream<T> removeLast(java.util.function.Predicate<T> predicate)
Description copied from interface:Seq
Removes the last occurrence that satisfy predicate- Specified by:
removeLast
in interfaceLinearSeq<T>
- Specified by:
removeLast
in interfaceSeq<T>
- Parameters:
predicate
- an predicate- Returns:
- a new Seq
-
removeAt
public final Stream<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).
-
removeAll
public final Stream<T> removeAll(T element)
Description copied from interface:Seq
Removes all occurrences of the given element.
-
removeAll
public final Stream<T> removeAll(java.lang.Iterable<? extends T> elements)
Description copied from interface:Seq
Removes all occurrences of the given elements.
-
removeAll
@Deprecated public final Stream<T> removeAll(java.util.function.Predicate<? super T> predicate)
Deprecated.Description copied from interface:Seq
Returns a new Seq consisting of all elements which do not satisfy the given predicate.
-
replace
public final Stream<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 interfaceLinearSeq<T>
- Specified by:
replace
in interfaceSeq<T>
- Specified by:
replace
in interfaceTraversable<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 final Stream<T> replaceAll(T currentElement, T newElement)
Description copied from interface:Traversable
Replaces all occurrences of the given currentElement with newElement.- Specified by:
replaceAll
in interfaceLinearSeq<T>
- Specified by:
replaceAll
in interfaceSeq<T>
- Specified by:
replaceAll
in interfaceTraversable<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.
-
retainAll
public final Stream<T> retainAll(java.lang.Iterable<? extends T> elements)
Description copied from interface:Traversable
Keeps all occurrences of the given elements from this.
-
reverse
public final Stream<T> reverse()
Description copied from interface:Seq
Reverses the order of elements.
-
rotateLeft
public final Stream<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 interfaceLinearSeq<T>
- Specified by:
rotateLeft
in interfaceSeq<T>
- Parameters:
n
- distance of left rotation- Returns:
- the rotated elements.
-
rotateRight
public final Stream<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 interfaceLinearSeq<T>
- Specified by:
rotateRight
in interfaceSeq<T>
- Parameters:
n
- distance of right rotation- Returns:
- the rotated elements.
-
scan
public final Stream<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 interfaceLinearSeq<T>
- Specified by:
scan
in interfaceSeq<T>
- Specified by:
scan
in interfaceTraversable<T>
- Parameters:
zero
- neutral element for the operator opoperation
- the associative operator for the scan- Returns:
- a new traversable collection containing the prefix scan of the elements in this traversable collection
-
scanLeft
public final <U> Stream<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 interfaceLinearSeq<T>
- Specified by:
scanLeft
in interfaceSeq<T>
- Specified by:
scanLeft
in interfaceTraversable<T>
- Type Parameters:
U
- the type of the elements in the resulting collection- Parameters:
zero
- the initial valueoperation
- the binary operator applied to the intermediate result and the element- Returns:
- collection with intermediate results
-
scanRight
public final <U> Stream<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 interfaceLinearSeq<T>
- Specified by:
scanRight
in interfaceSeq<T>
- Specified by:
scanRight
in interfaceTraversable<T>
- Type Parameters:
U
- the type of the elements in the resulting collection- Parameters:
zero
- the initial valueoperation
- the binary operator applied to the intermediate result and the element- Returns:
- collection with intermediate results
-
shuffle
public final Stream<T> shuffle()
Description copied from interface:Seq
Randomize the order of the elements in the current sequence.
-
shuffle
public final Stream<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.
-
slice
public final Stream<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 specifiedbeginIndex
and extends to the element at indexendIndex - 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)
Seq.subSequence(int, int)
which throws in some cases instead of returning a sequence.
-
slideBy
public final Iterator<Stream<T>> slideBy(java.util.function.Function<? super T,?> classifier)
Description copied from interface:Traversable
Slides a non-overlapping window of a variable size over thisTraversable
.Each window contains elements with the same class, as determined by
classifier
. Two consecutive values in thisTraversable
will be in the same window only ifclassifier
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]]
-
sliding
public final Iterator<Stream<T>> sliding(int size)
Description copied from interface:Traversable
Slides a window of a specificsize
and step size 1 over thisTraversable
by callingTraversable.sliding(int, int)
.
-
sliding
public final Iterator<Stream<T>> sliding(int size, int step)
Description copied from interface:Traversable
Slides a window of a specificsize
andstep
size over thisTraversable
.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]]
-
sorted
public final Stream<T> sorted()
Description copied from interface:Seq
Sorts this elements according to their natural order. If this elements are notComparable
, ajava.lang.ClassCastException
may be thrown.
-
sorted
public final Stream<T> sorted(java.util.Comparator<? super T> comparator)
Description copied from interface:Seq
Sorts this elements according to the providedComparator
. If this elements are notComparable
, ajava.lang.ClassCastException
may be thrown.
-
sortBy
public final <U extends java.lang.Comparable<? super U>> Stream<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 givenmapper
.
-
sortBy
public final <U> Stream<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 givenmapper
.
-
span
public final Tuple2<Stream<T>,Stream<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 givenpredicate
and the second element is the remainder.
-
splitAt
public final Tuple2<Stream<T>,Stream<T>> splitAt(int n)
Description copied from interface:Seq
Splits a Seq at the specified index. The result ofsplitAt(n)
is equivalent toTuple.of(take(n), drop(n))
.
-
splitAt
public final Tuple2<Stream<T>,Stream<T>> splitAt(java.util.function.Predicate<? super T> predicate)
Description copied from interface:Seq
Splits a sequence at the first element which satisfies thePredicate
, e.g. Tuple(init, element+tail).
-
splitAtInclusive
public final Tuple2<Stream<T>,Stream<T>> splitAtInclusive(java.util.function.Predicate<? super T> predicate)
Description copied from interface:Seq
Splits a sequence at the first element which satisfies thePredicate
, e.g. Tuple(init+element, tail).- Specified by:
splitAtInclusive
in interfaceSeq<T>
- Parameters:
predicate
- An predicate- Returns:
- A
Tuple
containing divided sequences
-
stringPrefix
public final 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 interfaceValue<T>
- Returns:
- This type name.
-
subSequence
public final Stream<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 specifiedbeginIndex
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
Seq.drop(int)
which is similar but does not throw.- Specified by:
subSequence
in interfaceLinearSeq<T>
- Specified by:
subSequence
in interfaceSeq<T>
- Parameters:
beginIndex
- the beginning index, inclusive- Returns:
- the specified subsequence
-
subSequence
public final Stream<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 specifiedbeginIndex
and extends to the element at indexendIndex - 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
Seq.slice(int, int)
which returns an empty sequence instead of throwing.- Specified by:
subSequence
in interfaceLinearSeq<T>
- Specified by:
subSequence
in interfaceSeq<T>
- Parameters:
beginIndex
- the beginning index, inclusiveendIndex
- the end index, exclusive- Returns:
- the specified subsequence
-
tail
public abstract Stream<T> tail()
Description copied from interface:Traversable
Drops the first element of a non-empty Traversable.
-
tailOption
public final Option<Stream<T>> tailOption()
Description copied from interface:Traversable
Drops the first element of a non-empty Traversable and returns anOption
.- Specified by:
tailOption
in interfaceLinearSeq<T>
- Specified by:
tailOption
in interfaceSeq<T>
- Specified by:
tailOption
in interfaceTraversable<T>
- Returns:
Some(traversable)
orNone
if this is empty.
-
take
public final Stream<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 ifn < 0
orn > length()
.In the case of
n < 0
the empty instance is returned, in the case ofn > length()
this is returned.
-
takeUntil
public final Stream<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 interfaceLinearSeq<T>
- Specified by:
takeUntil
in interfaceSeq<T>
- Specified by:
takeUntil
in interfaceTraversable<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.
-
takeWhile
public final Stream<T> 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 interfaceLinearSeq<T>
- Specified by:
takeWhile
in interfaceSeq<T>
- Specified by:
takeWhile
in interfaceTraversable<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.
-
takeRight
public final Stream<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 ifn < 0
orn > length()
.In the case of
n < 0
the empty instance is returned, in the case ofn > length()
this is returned.- Specified by:
takeRight
in interfaceLinearSeq<T>
- Specified by:
takeRight
in interfaceSeq<T>
- Specified by:
takeRight
in interfaceTraversable<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.
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takeRightUntil
public final Stream<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 interfaceLinearSeq<T>
- Specified by:
takeRightUntil
in interfaceSeq<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.
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takeRightWhile
public final Stream<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 interfaceLinearSeq<T>
- Specified by:
takeRightWhile
in interfaceSeq<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.
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transform
public final <U> U transform(java.util.function.Function<? super Stream<T>,? extends U> f)
Transforms thisStream
.- Type Parameters:
U
- Type of transformation result- Parameters:
f
- A transformation- Returns:
- An instance of type
U
- Throws:
java.lang.NullPointerException
- iff
is null
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unzip
public final <T1,T2> Tuple2<Stream<T1>,Stream<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 interfaceLinearSeq<T>
- Specified by:
unzip
in interfaceSeq<T>
- Specified by:
unzip
in interfaceTraversable<T>
- Type Parameters:
T1
- 1st element type of a pair returned by unzipperT2
- 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 final <T1,T2,T3> Tuple3<Stream<T1>,Stream<T2>,Stream<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 interfaceSeq<T>
- Specified by:
unzip3
in interfaceTraversable<T>
- Type Parameters:
T1
- 1st element type of a triplet returned by unzipperT2
- 2nd element type of a triplet returned by unzipperT3
- 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 final Stream<T> update(int index, T element)
Description copied from interface:Seq
Updates the given element at the specified index.
-
update
public final Stream<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.
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zip
public final <U> Stream<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 interfaceLinearSeq<T>
- Specified by:
zip
in interfaceSeq<T>
- Specified by:
zip
in interfaceTraversable<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 final <U,R> Stream<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 interfaceLinearSeq<T>
- Specified by:
zipWith
in interfaceSeq<T>
- Specified by:
zipWith
in interfaceTraversable<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 final <U> Stream<Tuple2<T,U>> zipAll(java.lang.Iterable<? extends U> iterable, 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 interfaceLinearSeq<T>
- Specified by:
zipAll
in interfaceSeq<T>
- Specified by:
zipAll
in interfaceTraversable<T>
- Type Parameters:
U
- The type of the second half of the returned pairs.- Parameters:
iterable
- 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 final Stream<Tuple2<T,java.lang.Integer>> zipWithIndex()
Description copied from interface:Traversable
Zips this traversable with its indices.- Specified by:
zipWithIndex
in interfaceLinearSeq<T>
- Specified by:
zipWithIndex
in interfaceSeq<T>
- Specified by:
zipWithIndex
in interfaceTraversable<T>
- Returns:
- A new traversable containing all elements of this traversable paired with their index, starting with 0.
-
zipWithIndex
public final <U> Stream<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 interfaceLinearSeq<T>
- Specified by:
zipWithIndex
in interfaceSeq<T>
- Specified by:
zipWithIndex
in interfaceTraversable<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.
-
extend
public final Stream<T> extend(T next)
Extends (continues) thisStream
with a constantly repeated value.- Parameters:
next
- value with which the stream should be extended- Returns:
- new
Stream
composed from this stream extended with a Stream of provided value
-
extend
public final Stream<T> extend(java.util.function.Supplier<? extends T> nextSupplier)
Extends (continues) thisStream
with values provided by aSupplier
- Parameters:
nextSupplier
- a supplier which will provide values for extending a stream- Returns:
- new
Stream
composed from this stream extended with values provided by the supplier
-
extend
public final Stream<T> extend(java.util.function.Function<? super T,? extends T> nextFunction)
Extends (continues) thisStream
with a Stream of values created by applying consecutively providedFunction
to the last element of the original Stream.- Parameters:
nextFunction
- a function which calculates the next value basing on the previous value- Returns:
- new
Stream
composed from this stream extended with values calculated by the provided function
-
-