Vavr 0.10.6 · io.vavr.collection.Traversable · APIdia, the JavaDoc alternative

Method Summary

Modifier and Type	Method and Description
public default < key class type K> Option<Map<K, T>>	Returns: A Map containing the elements arranged by their keys. arrangeBy(Function<? super T, ? extends K> A function which extracts a key from elements getKey) Matches each element with a unique key that you extract from it.
public default Option<Double>	Returns: `Some(average)` or `None`, if there are no elements average() Calculates the average of this elements, assuming that the element type is `Number`.
public < The new element type R> Traversable<R>	Returns: A new `Traversable` instance containing elements of type `R` collect(PartialFunction<? super T, ? extends R> A function that is not necessarily defined of all elements of this traversable. partialFunction) Collects all elements that are in the domain of the given `partialFunction` by mapping the elements to type `R`.
public default boolean	Returns: true, if this List contains all given elements, false otherwise. containsAll(Iterable<? extends T> A List of values of type T. elements) Tests if this Traversable contains all given elements.
public default int	Returns: A number `>= 0` count(Predicate<? super T> A predicate predicate) Counts the elements which satisfy the given predicate.
public Traversable<T>	Returns: a new `Traversable` containing this elements without duplicates distinct() Returns a new version of this which contains no duplicates.
public Traversable<T>	Returns: a new `Traversable` containing this elements without duplicates distinctBy(Comparator<? super T> A comparator comparator) Returns a new version of this which contains no duplicates.
public < key type U> Traversable<T>	Returns: a new `Traversable` containing this elements without duplicates distinctBy(Function<? super T, ? extends U> A key extractor keyExtractor) Returns a new version of this which contains no duplicates.
public Traversable<T>	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. drop(int The number of elements to drop. n) Drops the first n elements of this or all elements, if this length < n.
public Traversable<T>	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. dropRight(int The number of elements to drop. n) Drops the last n elements of this or all elements, if this length < n.
public Traversable<T>	Returns: a new instance consisting of all elements starting from the first one which does satisfy the given predicate. dropUntil(Predicate<? super T> A condition tested subsequently for this elements. predicate) Drops elements until the predicate holds for the current element.
public Traversable<T>	Returns: a new instance consisting of all elements starting from the first one which does not satisfy the given predicate. dropWhile(Predicate<? super T> A condition tested subsequently for this elements. predicate) Drops elements while the predicate holds for the current element.
public boolean	Returns: true, if this collection equals the given object according to the rules described above, false otherwise. equals(Object an object, may be null obj) Redeclares io.vavr.Value.equals. In Vavr there are four basic classes of collections: Seq (sequential elements) Set (distinct elements) Map (indexed elements) Multimap (indexed collections)
public default boolean	Returns: true, if predicate holds for a unique element, false otherwise existsUnique(Predicate<? super T> A Predicate predicate) Checks, if a unique elements exists such that the predicate holds.
public Traversable<T>	Returns: a new traversable filter(Predicate<? super T> A predicate predicate) Returns a new traversable consisting of all elements which satisfy the given predicate.
public default Option<T>	Returns: Some(element) or None, where element may be null (i.e. `List.of(null).find(e -> e == null)`). find(Predicate<? super T> A predicate. predicate) Returns the first element of this which satisfies the given predicate.
public default Option<T>	Returns: Some(element) or None, where element may be null (i.e. `List.of(null).find(e -> e == null)`). findLast(Predicate<? super T> A predicate. predicate) Returns the last element of this which satisfies the given predicate.
public < The resulting component type. U> Traversable<U>	Returns: A new Traversable instance. flatMap(Function<? super T, ? extends Iterable<? extends U>> A mapper mapper) FlatMaps this Traversable.
public default <U> U	foldLeft(U A zero element to start with. zero, BiFunction<? super U, ? super T, ? extends U> A function which combines elements. f) Implements io.vavr.collection.Foldable.foldLeft. Folds this elements from the left, starting with `zero` and successively calling `combine`.
public <U> U	foldRight(U A zero element to start with. zero, BiFunction<? super T, ? super U, ? extends U> A function which combines elements. f) Redeclares io.vavr.collection.Foldable.foldRight. Folds this elements from the right, starting with `zero` and successively calling `combine`.
public default void	forEachWithIndex(ObjIntConsumer<? super T> A `ObjIntConsumer` action) Performs an action on each element.
public default T	Returns: the first value get() Implements io.vavr.Value.get. Gets the first value in iteration order if this `Traversable` is not empty, otherwise throws.
public < classified class type C> Map<C, ? extends Traversable<T>>	Returns: A Map containing the grouped elements groupBy(Function<? super T, ? extends C> A function which classifies elements into classes classifier) Groups this elements by classifying the elements.
public Iterator<? extends Traversable<T>>	Returns: A new Iterator of grouped blocks of the given size grouped(int a positive block size size) Groups this `Traversable` into fixed size blocks.
public boolean	Returns: true, if this Traversable is known to have a finite size, false otherwise. hasDefiniteSize() Checks if this Traversable is known to have a finite size.
public int	Returns: The hash code of this collection hashCode() Redeclares io.vavr.Value.hashCode. Returns the hash code of this collection.
public T	Returns: The first element of this Traversable. head() Returns the first element of a non-empty Traversable.
public default Option<T>	Returns: `Some(element)` or `None` if this is empty. headOption() Returns the first element of a non-empty Traversable as `Option`.
public Traversable<T>	Returns: a new instance containing all elements except the last. init() Dual of tail(), returning all elements except the last.
public default Option<? extends Traversable<T>>	Returns: `Some(traversable)` or `None` if this is empty. initOption() Dual of tailOption(), returning all elements except the last as `Option`.
public default boolean	Returns: true if this Traversable may consist of distinct elements only, false otherwise. isDistinct() Checks if this Traversable may consist of distinct elements only.
public default boolean	Returns: true, if this Traversable contains no elements, false otherwise. isEmpty() Implements io.vavr.Value.isEmpty. Checks if this Traversable is empty.
public default boolean	Returns: true, if this Traversable is ordered, false otherwise. isOrdered() Checks if this Traversable is ordered
public default boolean	Returns: true, if the insertion order of elements is preserved, false otherwise. isSequential() Checks if the elements of this Traversable appear in encounter order.
public default boolean	Returns: `false` isSingleValued() Implements io.vavr.Value.isSingleValued. Each of Vavr's collections may contain more than one element.
public boolean	Returns: true, if this Traversable is known to be traversable repeatedly, false otherwise. isTraversableAgain() Checks if this Traversable can be repeatedly traversed.
public default Iterator<T>	Returns: A new Iterator of this Traversable elements. iterator() Implements io.vavr.Value.iterator. An iterator by means of head() and tail().
public T	Returns: the last element. last() Dual of head(), returning the last element.
public default Option<T>	Returns: `Some(element)` or `None` if this is empty. lastOption() Dual of headOption(), returning the last element as `Option`.
public int	Returns: the number of elements length() Computes the number of elements of this Traversable.
public < Component type of the target Traversable U> Traversable<U>	Returns: a mapped Traversable map(Function<? super T, ? extends U> A mapper. mapper) Redeclares io.vavr.Value.map. Maps the elements of this `Traversable` to elements of a new type preserving their order, if any.
public default Option<T>	Returns: `Some(maximum)` of this elements or `None` if this is empty max() Calculates the maximum of this elements according to their natural order.
public default Option<T>	Returns: `Some(maximum)` of this elements or `None` if this is empty maxBy(Comparator<? super T> A non-null element comparator comparator) Calculates the maximum of this elements using a specific comparator.
public default < The type where elements are compared U extends Comparable<? super U>> Option<T>	Returns: The element of type T which is the maximum within U maxBy(Function<? super T, ? extends U> A function that maps this elements to comparable elements f) Calculates the maximum of this elements within the co-domain of a specific function.
public default Option<T>	Returns: `Some(minimum)` of this elements or `None` if this is empty min() Calculates the minimum of this elements according to their natural order in O(n).
public default Option<T>	Returns: `Some(minimum)` of this elements or `None` if this is empty minBy(Comparator<? super T> A non-null element comparator comparator) Calculates the minimum of this elements using a specific comparator.
public default < The type where elements are compared U extends Comparable<? super U>> Option<T>	Returns: The element of type T which is the minimum within U minBy(Function<? super T, ? extends U> A function that maps this elements to comparable elements f) Calculates the minimum of this elements within the co-domain of a specific function.
public default CharSeq	Returns: a new `CharSeq` mkCharSeq() Joins the elements of this by concatenating their string representations.
public default CharSeq	Returns: A new `CharSeq` mkCharSeq(CharSequence A delimiter string put between string representations of elements of this delimiter) Joins the string representations of this elements using a specific delimiter.
public default CharSeq	Returns: a new `CharSeq` mkCharSeq(CharSequence prefix of the resulting `CharSeq` prefix, CharSequence A delimiter string put between string representations of elements of this delimiter, CharSequence suffix of the resulting `CharSeq` suffix) Joins the string representations of this elements using a specific delimiter, prefix and suffix.
public default String	Returns: a new String mkString() Joins the elements of this by concatenating their string representations.
public default String	Returns: A new String mkString(CharSequence A delimiter string put between string representations of elements of this delimiter) Joins the string representations of this elements using a specific delimiter.
public default String	Returns: a new String mkString(CharSequence prefix of the resulting string prefix, CharSequence A delimiter string put between string representations of elements of this delimiter, CharSequence suffix of the resulting string suffix) Joins the string representations of this elements using a specific delimiter, prefix and suffix.
public static < Component type of the `Traversable`. T> Traversable<T>	Returns: the given `traversable` instance as narrowed type `Traversable<T>`. narrow(Traversable<? extends T> An `Traversable`. traversable) Narrows a widened `Traversable<?`
public default boolean	Returns: true, if an underlying value is present, false otherwise. nonEmpty() Checks, this `Traversable` is not empty.
public Traversable<T>	Returns: this `Traversable` if it is nonempty, otherwise return the alternative. orElse(Iterable<? extends T> An alternative `Traversable` other) Returns this `Traversable` if it is nonempty, otherwise return the alternative.
public Traversable<T>	Returns: this `Traversable` if it is nonempty, otherwise return the result of evaluating supplier. orElse(Supplier<? extends Iterable<? extends T>> An alternative `Traversable` supplier supplier) Returns this `Traversable` if it is nonempty, otherwise return the result of evaluating supplier.
public Tuple2<? extends Traversable<T>, ? extends Traversable<T>>	Returns: A disjoint union of two traversables. The first `Traversable` contains all elements that satisfy the given `predicate`, the second `Traversable` contains all elements that don't. The original order of elements is preserved. partition(Predicate<? super T> A predicate which classifies an element if it is in the first or the second traversable. predicate) Creates a partition of this `Traversable` by splitting this elements in two in distinct traversables according to a predicate.
public Traversable<T>	peek(Consumer<? super T> The action that will be performed on the element(s). action) Redeclares io.vavr.Value.peek. Performs the given `action` on the first element if this is an eager implementation.
public default Number	Returns: a `Number` representing the sum of this elements product() Calculates the product of this elements.
public default T	Returns: the reduced value. reduceLeft(BiFunction<? super T, ? super T, ? extends T> A BiFunction of type T op) Implements io.vavr.collection.Foldable.reduceLeft. Accumulates the elements of this Traversable by successively calling the given operation `op` from the left.
public default Option<T>	Returns: a reduced value reduceLeftOption(BiFunction<? super T, ? super T, ? extends T> A BiFunction of type T op) Implements io.vavr.collection.Foldable.reduceLeftOption. Shortcut for `isEmpty() ?`
public default T	Returns: the reduced value. reduceRight(BiFunction<? super T, ? super T, ? extends T> An operation of type T op) Implements io.vavr.collection.Foldable.reduceRight. Accumulates the elements of this Traversable by successively calling the given operation `op` from the right.
public default Option<T>	Returns: a reduced value reduceRightOption(BiFunction<? super T, ? super T, ? extends T> An operation of type T op) Implements io.vavr.collection.Foldable.reduceRightOption. Shortcut for `isEmpty() ?`
public default Traversable<T>	Returns: a new traversable reject(Predicate<? super T> A predicate predicate) Returns a new traversable consisting of all elements which do not satisfy the given predicate.
public Traversable<T>	Returns: a Traversable containing all elements of this where the first occurrence of currentElement is replaced with newElement. replace(T An element to be substituted. currentElement, T A replacement for currentElement. newElement) Replaces the first occurrence (if exists) of the given currentElement with newElement.
public Traversable<T>	Returns: a Traversable containing all elements of this where all occurrences of currentElement are replaced with newElement. replaceAll(T An element to be substituted. currentElement, T A replacement for currentElement. newElement) Replaces all occurrences of the given currentElement with newElement.
public Traversable<T>	Returns: a Traversable containing all occurrences of the given elements. retainAll(Iterable<? extends T> Elements to be kept. elements) Keeps all occurrences of the given elements from this.
public Traversable<T>	Returns: a new traversable collection containing the prefix scan of the elements in this traversable collection scan(T neutral element for the operator op zero, BiFunction<? super T, ? super T, ? extends T> the associative operator for the scan operation) Computes a prefix scan of the elements of the collection.
public < the type of the elements in the resulting collection U> Traversable<U>	Returns: collection with intermediate results scanLeft(U the initial value zero, BiFunction<? super U, ? super T, ? extends U> the binary operator applied to the intermediate result and the element operation) Produces a collection containing cumulative results of applying the operator going left to right.
public < the type of the elements in the resulting collection U> Traversable<U>	Returns: collection with intermediate results scanRight(U the initial value zero, BiFunction<? super T, ? super U, ? extends U> the binary operator applied to the intermediate result and the element operation) Produces a collection containing cumulative results of applying the operator going right to left.
public default T	Returns: the single element from the Traversable single() Returns the single element of this Traversable or throws, if this is empty or contains more than one element.
public default Option<T>	Returns: `Some(element)` or `None` if the Traversable does not contain a single element. singleOption() Returns the only element of a Traversable as `Option`.
public default int	Returns: the number of elements size() Computes the number of elements of this Traversable.
public Iterator<? extends Traversable<T>>	Returns: A new Iterator of windows of the grouped elements slideBy(Function<? super T, ?> A function which classifies elements into classes classifier) Slides a non-overlapping window of a variable size over this `Traversable`.
public Iterator<? extends Traversable<T>>	Returns: a new Iterator of windows of a specific size using step size 1 sliding(int a positive window size size) Slides a window of a specific `size` and step size 1 over this `Traversable` by calling `sliding(int, int)`.
public Iterator<? extends Traversable<T>>	Returns: a new Iterator of windows of a specific size using a specific step size sliding(int a positive window size size, int a positive step size step) Slides a window of a specific `size` and `step` size over this `Traversable`.
public Tuple2<? extends Traversable<T>, ? extends Traversable<T>>	Returns: a `Tuple` containing the longest prefix of elements that satisfy p and the remainder. span(Predicate<? super T> A predicate. predicate) Returns a tuple where the first element is the longest prefix of elements that satisfy the given `predicate` and the second element is the remainder.
public default Spliterator<T>	spliterator() Overrides default io.vavr.Value.spliterator. Creates a `Spliterator` over the elements described by this `Iterable`.
public default Number	Returns: a `Number` representing the sum of this elements sum() Calculates the sum of this elements.
public Traversable<T>	Returns: A new instance of Traversable containing all elements except the first. tail() Drops the first element of a non-empty Traversable.
public Option<? extends Traversable<T>>	Returns: `Some(traversable)` or `None` if this is empty. tailOption() Drops the first element of a non-empty Traversable and returns an `Option`.
public Traversable<T>	Returns: A new instance consisting of the first n elements of this or all elements, if this has less than n elements. take(int The number of elements to take. n) Takes the first n elements of this or all elements, if this length < n.
public Traversable<T>	Returns: A new instance consisting of the last n elements of this or all elements, if this has less than n elements. takeRight(int The number of elements to take. n) Takes the last n elements of this or all elements, if this length < n.
public Traversable<T>	Returns: a new instance consisting of all elements before the first one which does satisfy the given predicate. takeUntil(Predicate<? super T> A condition tested subsequently for this elements. predicate) Takes elements until the predicate holds for the current element.
public Traversable<T>	Returns: a new instance consisting of all elements before the first one which does not satisfy the given predicate. takeWhile(Predicate<? super T> A condition tested subsequently for the contained elements. predicate) Takes elements while the predicate holds for the current element.
public < 1st element type of a pair returned by unzipper T1, 2nd element type of a pair returned by unzipper T2> Tuple2<? extends Traversable<T1>, ? extends Traversable<T2>>	Returns: A pair of set containing elements split by unzipper unzip(Function<? super T, Tuple2<? extends T1, ? extends T2>> a function which converts elements of this to pairs unzipper) Unzips this elements by mapping this elements to pairs which are subsequently split into two distinct sets.
public < 1st element type of a triplet returned by unzipper T1, 2nd element type of a triplet returned by unzipper T2, 3rd element type of a triplet returned by unzipper T3> Tuple3<? extends Traversable<T1>, ? extends Traversable<T2>, ? extends Traversable<T3>>	Returns: A triplet of set containing elements split by unzipper unzip3(Function<? super T, Tuple3<? extends T1, ? extends T2, ? extends T3>> a function which converts elements of this to pairs unzipper) Unzips this elements by mapping this elements to triples which are subsequently split into three distinct sets.
public < The type of the second half of the returned pairs. U> Traversable<Tuple2<T, U>>	Returns: a new traversable containing pairs consisting of corresponding elements of this traversable and `that` iterable. zip(Iterable<? extends U> The Iterable providing the second half of each result pair. that) Returns a traversable formed from this traversable and another Iterable collection by combining corresponding elements in pairs.
public < The type of the second half of the returned pairs. U> Traversable<Tuple2<T, U>>	Returns: A new traversable containing pairs consisting of corresponding elements of this traversable and that. zipAll(Iterable<? extends U> The Iterable providing the second half of each result pair. that, T The element to be used to fill up the result if this traversable is shorter than that. thisElem, U The element to be used to fill up the result if that is shorter than this traversable. thatElem) Returns a traversable formed from this traversable and another Iterable by combining corresponding elements in pairs.
public < The type of the second parameter of the mapper. U, The type of the mapped elements. R> Traversable<R>	Returns: a new traversable containing mapped elements of this traversable and `that` iterable. zipWith(Iterable<? extends U> The Iterable providing the second parameter of the mapper. that, BiFunction<? super T, ? super U, ? extends R> a mapper. mapper) Returns a traversable formed from this traversable and another Iterable collection by mapping elements.
public Traversable<Tuple2<T, Integer>>	Returns: A new traversable containing all elements of this traversable paired with their index, starting with 0. zipWithIndex() Zips this traversable with its indices.
public < The type of the mapped elements. U> Traversable<U>	Returns: a new traversable containing elements of this traversable, zipped with indices, and mapped with mapper provided. zipWithIndex(BiFunction<? super T, ? super Integer, ? extends U> a mapper. mapper) Zips this traversable with its indices by applying mapper provided.

public Interface Traversable<T>

Method Summary