Interface Multimap<K,V>

Type Parameters:

K - Key type

V - Value type

All Superinterfaces:

Foldable<Tuple2<K,V>>, Function<K, Traversable<V>>, Function1<K, Traversable<V>>, Iterable<Tuple2<K,V>>, PartialFunction<K, Traversable<V>>, Serializable, Traversable<Tuple2<K,V>>, Value<Tuple2<K,V>>

All Known Subinterfaces:

SortedMultimap<K,V>

All Known Implementing Classes:

AbstractMultimap, HashMultimap, LinkedHashMultimap, TreeMultimap

public interface Multimap<K,V>
extends Traversable<Tuple2<K,V>>, PartialFunction<K, Traversable<V>>, Serializable

An immutable Multimap interface.

Basic operations:

• containsKey(Object)
• containsValue(Object)
• get(Object)
• getContainerType()
• keySet()
• merge(Multimap)
• merge(Multimap, BiFunction)
• put(Object, Object)
• put(Tuple2)
• values()

Conversion:

• toJavaMap()

Filtering:

• filter(BiPredicate)
• filterKeys(Predicate)
• filterValues(Predicate)
• reject(BiPredicate)
• rejectKeys(Predicate)
• rejectValues(Predicate)
• remove(Object)
• remove(Object, Object)
• removeAll(Iterable)

Iteration:

• forEach(BiConsumer)
• iterator(BiFunction)

Transformation:

• bimap(Function, Function)
• flatMap(BiFunction)
• map(BiFunction)
• mapValues(Function)
• transform(Function)
• unzip(BiFunction)
• unzip3(BiFunction)

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static enum	Multimap.ContainerType	Defines the type of container used to store values associated with keys in a Multimap.

Field Summary

Fields

Modifier and Type	Field	Description
static final long	serialVersionUID	The serial version UID for serialization.

Method Summary

Modifier and Type	Method	Description
default Traversable<V>	apply(K key)	Deprecated.
Map<K, Traversable<V>>	asMap()	Converts this Multimap to a Map
default PartialFunction<K, Traversable<V>>	asPartialFunction()	Turns this Multimap into a PartialFunction which is defined at a specific index, if this Multimap contains the given key.
<K2,V2> Multimap<K2,V2>	bimap(Function<? super K, ? extends K2> keyMapper, Function<? super V, ? extends V2> valueMapper)	Maps this Multimap to a new Multimap with different component type by applying a function to its elements.
default <R> Seq<R>	collect(@NonNull PartialFunction<? super Tuple2<K,V>, ? extends R> partialFunction)	Applies a PartialFunction to all elements that are defined for it and collects the results.
default boolean	contains(@NonNull Tuple2<K,V> element)	Shortcut for exists(e -> Objects.equals(e, element)), tests if the given element is contained.
boolean	containsKey(K key)	Returns true if this multimap contains a mapping for the specified key.
default boolean	containsValue(V value)	Returns true if this multimap maps one or more keys to the specified value.
Multimap<K,V>	distinct()	Returns a new Traversable containing the elements of this instance with all duplicates removed.
Multimap<K,V>	distinctBy(@NonNull Comparator<? super Tuple2<K,V>> comparator)	Returns a new Traversable containing the elements of this instance without duplicates, as determined by the given comparator.
<U> Multimap<K,V>	distinctBy(@NonNull Function<? super Tuple2<K,V>, ? extends U> keyExtractor)	Returns a new Traversable containing the elements of this instance without duplicates, based on keys extracted from elements using keyExtractor.
Multimap<K,V>	drop(int n)	Returns a new Traversable without the first n elements, or an empty instance if this contains fewer than n elements.
Multimap<K,V>	dropRight(int n)	Returns a new Traversable without the last n elements, or an empty instance if this contains fewer than n elements.
Multimap<K,V>	dropUntil(@NonNull Predicate<? super Tuple2<K,V>> predicate)	Returns a new Traversable starting from the first element that satisfies the given predicate, dropping all preceding elements.
Multimap<K,V>	dropWhile(@NonNull Predicate<? super Tuple2<K,V>> predicate)	Returns a new Traversable starting from the first element that does not satisfy the given predicate, dropping all preceding elements.
Multimap<K,V>	filter(@NonNull BiPredicate<? super K, ? super V> predicate)	Returns a new Multimap consisting of all elements which satisfy the given predicate.
Multimap<K,V>	filter(@NonNull Predicate<? super Tuple2<K,V>> predicate)	Returns a new traversable containing only the elements that satisfy the given predicate.
Multimap<K,V>	filterKeys(@NonNull Predicate<? super K> predicate)	Returns a new Multimap consisting of all elements with keys which satisfy the given predicate.
Multimap<K,V>	filterValues(@NonNull Predicate<? super V> predicate)	Returns a new Multimap consisting of all elements with values which satisfy the given predicate.
<K2,V2> Multimap<K2,V2>	flatMap(@NonNull BiFunction<? super K, ? super V, ? extends Iterable<Tuple2<K2,V2>>> mapper)	FlatMaps this Multimap to a new Multimap with different component type.
default <U> Seq<U>	flatMap(@NonNull Function<? super Tuple2<K,V>, ? extends Iterable<? extends U>> mapper)	Flat-maps this entries to a sequence of values.
default <U> U	foldRight(U zero, @NonNull BiFunction<? super Tuple2<K,V>, ? super U, ? extends U> f)	Folds the elements of this structure from the right, starting with the given zero value and successively applying the combine function to each element.
default void	forEach(@NonNull BiConsumer<K,V> action)	Performs an action on key, value pair.
Option<Traversable<V>>	get(K key)	Returns the Some of value to which the specified key is mapped, or None if this multimap contains no mapping for the key.
Multimap.ContainerType	getContainerType()	Returns the type of the Traversable value container of this MultiMap.
Traversable<V>	getOrElse(K key, Traversable<? extends V> defaultValue)	Returns the value associated with a key, or a default value if the key is not contained in the map
<C> Map<C, ? extends Multimap<K,V>>	groupBy(@NonNull Function<? super Tuple2<K,V>, ? extends C> classifier)	Groups elements of this Traversable based on a classifier function.
Iterator<? extends Multimap<K,V>>	grouped(int size)	Splits this Traversable into consecutive blocks of the given size.
default boolean	hasDefiniteSize()	Indicates whether this Traversable has a known finite size.
Multimap<K,V>	init()	Returns all elements of this Traversable except the last one.
Option<? extends Multimap<K,V>>	initOption()	Returns all elements of this Traversable except the last one, wrapped in an Option.
default boolean	isDefinedAt(K key)	Deprecated.
default boolean	isDistinct()	Indicates whether this Traversable may contain only distinct elements.
default boolean	isTraversableAgain()	Checks if this Traversable can be traversed multiple times without side effects.
@NonNull Iterator<Tuple2<K,V>>	iterator()	Returns an iterator over the elements of this Traversable, implemented via Traversable.head() and Traversable.tail().
default <U> Iterator<U>	iterator(@NonNull BiFunction<K, V, ? extends U> mapper)	Iterates this Multimap sequentially, mapping the (key, value) pairs to elements.
Set<K>	keySet()	Returns the keys contained in this multimap.
default int	length()	Returns the number of elements in this Traversable.
<K2,V2> Multimap<K2,V2>	map(@NonNull BiFunction<? super K, ? super V, Tuple2<K2,V2>> mapper)	Maps the entries of this Multimap to form a new Multimap.
default <U> Seq<U>	map(@NonNull Function<? super Tuple2<K,V>, ? extends U> mapper)	Maps the Multimap entries to a sequence of values.
default <U> Seq<U>	mapTo(U value)	Maps the underlying value to another fixed value.
default Seq<Void>	mapToVoid()	Maps the underlying value to Void
<V2> Multimap<K,V2>	mapValues(@NonNull Function<? super V, ? extends V2> valueMapper)	Maps the values of this Multimap while preserving the corresponding keys.
Multimap<K,V>	merge(@NonNull Multimap<? extends K, ? extends V> that)	Creates a new multimap which by merging the entries of this multimap and that multimap.
<K2 extends K, V2 extends V> Multimap<K,V>	merge(@NonNull Multimap<K2,V2> that, @NonNull BiFunction<Traversable<V>, Traversable<V2>, Traversable<V>> collisionResolution)	Creates a new multimap which by merging the entries of this multimap and that multimap.
static <K,V> Multimap<K,V>	narrow(Multimap<? extends K, ? extends V> map)	Narrows a widened Multimap<? extends K, ? extends V> to Multimap<K, V> by performing a type-safe cast.
Multimap<K,V>	orElse(Iterable<? extends Tuple2<K,V>> other)	Returns this Traversable if it is non-empty; otherwise, returns the given alternative.
Multimap<K,V>	orElse(@NonNull Supplier<? extends Iterable<? extends Tuple2<K,V>>> supplier)	Returns this Traversable if it is non-empty; otherwise, returns the result of evaluating the given supplier.
Tuple2<? extends Multimap<K,V>, ? extends Multimap<K,V>>	partition(@NonNull Predicate<? super Tuple2<K,V>> predicate)	Splits this Traversable into two partitions according to a predicate.
Multimap<K,V>	peek(@NonNull Consumer<? super Tuple2<K,V>> action)	Performs the given action on the first element if this is an eager implementation.
Multimap<K,V>	put(@NonNull Tuple2<? extends K, ? extends V> entry)	Convenience method for put(entry._1, entry._2).
Multimap<K,V>	put(K key, V value)	Associates the specified value with the specified key in this multimap.
Multimap<K,V>	reject(@NonNull BiPredicate<? super K, ? super V> predicate)	Returns a new Multimap consisting of all elements which do not satisfy the given predicate.
Multimap<K,V>	reject(@NonNull Predicate<? super Tuple2<K,V>> predicate)	Returns a new traversable containing only the elements that do not satisfy the given predicate.
Multimap<K,V>	rejectKeys(@NonNull Predicate<? super K> predicate)	Returns a new Multimap consisting of all elements with keys which do not satisfy the given predicate.
Multimap<K,V>	rejectValues(@NonNull Predicate<? super V> predicate)	Returns a new Multimap consisting of all elements with values which do not satisfy the given predicate.
Multimap<K,V>	remove(K key)	Removes the mapping for a key from this multimap if it is present.
Multimap<K,V>	remove(K key, V value)	Removes the key-value pair from this multimap if it is present.
Multimap<K,V>	removeAll(@NonNull Iterable<? extends K> keys)	Removes the mapping for a key from this multimap if it is present.
Multimap<K,V>	removeAll(@NonNull BiPredicate<? super K, ? super V> predicate)	Deprecated. Please use reject(BiPredicate)
Multimap<K,V>	removeKeys(@NonNull Predicate<? super K> predicate)	Deprecated. Please use rejectKeys(Predicate)
Multimap<K,V>	removeValues(@NonNull Predicate<? super V> predicate)	Deprecated. Please use rejectValues(Predicate)
Multimap<K,V>	replace(Tuple2<K,V> currentElement, Tuple2<K,V> newElement)	Replaces the first occurrence of currentElement with newElement, if it exists.
Multimap<K,V>	replace(K key, V oldValue, V newValue)	Replaces the entry with the specified key and oldValue.
Multimap<K,V>	replaceAll(Tuple2<K,V> currentElement, Tuple2<K,V> newElement)	Replaces all occurrences of currentElement with newElement.
Multimap<K,V>	replaceAll(@NonNull BiFunction<? super K, ? super V, ? extends V> function)	Replaces each entry's values with the result of invoking the given function on that each tuple until all entries have been processed or the function throws an exception.
Multimap<K,V>	replaceValue(K key, V value)	Replaces the entry for the specified key only if it is currently mapped to some value.
Multimap<K,V>	retainAll(@NonNull Iterable<? extends Tuple2<K,V>> elements)	Retains only the elements from this Traversable that are contained in the given elements.
Multimap<K,V>	scan(Tuple2<K,V> zero, @NonNull BiFunction<? super Tuple2<K,V>, ? super Tuple2<K,V>, ? extends Tuple2<K,V>> operation)	Computes a prefix scan of the elements of this Traversable.
default <U> Seq<U>	scanLeft(U zero, @NonNull BiFunction<? super U, ? super Tuple2<K,V>, ? extends U> operation)	Produces a collection containing cumulative results of applying the operator from left to right.
default <U> Seq<U>	scanRight(U zero, @NonNull BiFunction<? super Tuple2<K,V>, ? super U, ? extends U> operation)	Produces a collection containing cumulative results of applying the operator from right to left.
int	size()	Returns the number of elements in this Traversable.
Iterator<? extends Multimap<K,V>>	slideBy(@NonNull Function<? super Tuple2<K,V>, ?> classifier)	Partitions this Traversable into consecutive non-overlapping windows according to a classification function.
Iterator<? extends Multimap<K,V>>	sliding(int size)	Slides a window of a given size over this Traversable with a step size of 1.
Iterator<? extends Multimap<K,V>>	sliding(int size, int step)	Slides a window of a specific size with a given step over this Traversable.
Tuple2<? extends Multimap<K,V>, ? extends Multimap<K,V>>	span(@NonNull Predicate<? super Tuple2<K,V>> predicate)	Splits this Traversable into a prefix and remainder according to the given predicate.
Multimap<K,V>	tail()	Returns a new Traversable without its first element.
Option<? extends Multimap<K,V>>	tailOption()	Returns a new Traversable without its first element as an Option.
Multimap<K,V>	take(int n)	Returns the first n elements of this Traversable, or all elements if n exceeds the length.
Multimap<K,V>	takeRight(int n)	Returns the last n elements of this Traversable, or all elements if n exceeds the length.
Multimap<K,V>	takeUntil(@NonNull Predicate<? super Tuple2<K,V>> predicate)	Takes elements from this Traversable until the given predicate holds for an element.
Multimap<K,V>	takeWhile(@NonNull Predicate<? super Tuple2<K,V>> predicate)	Takes elements from this Traversable while the given predicate holds.
Map<K, Collection<V>>	toJavaMap()	Converts this Vavr Map to a java.util.Map while preserving characteristics like insertion order (LinkedHashMultimap) and sort order (SortedMultimap).
default <U> U	transform(@NonNull Function<? super Multimap<K,V>, ? extends U> f)	Transforms this Multimap.
default <T1,T2> Tuple2<Seq<T1>,Seq<T2>>	unzip(@NonNull BiFunction<? super K, ? super V, Tuple2<? extends T1, ? extends T2>> unzipper)	Unzips the entries of this Multimap by mapping each key-value pair to a pair and splitting them into two separate Seq collections.
default <T1,T2> Tuple2<Seq<T1>,Seq<T2>>	unzip(@NonNull Function<? super Tuple2<K,V>, Tuple2<? extends T1, ? extends T2>> unzipper)	Unzips the elements of this Traversable by mapping each element to a pair and splitting them into two separate Traversable collections.
default <T1,T2,T3> Tuple3<Seq<T1>,Seq<T2>,Seq<T3>>	unzip3(@NonNull BiFunction<? super K, ? super V, Tuple3<? extends T1, ? extends T2, ? extends T3>> unzipper)	Unzips the entries of this Multimap by mapping each key-value pair to a triple and splitting them into three separate Seq collections.
default <T1,T2,T3> Tuple3<Seq<T1>,Seq<T2>,Seq<T3>>	unzip3(@NonNull Function<? super Tuple2<K,V>, Tuple3<? extends T1, ? extends T2, ? extends T3>> unzipper)	Unzips the elements of this Traversable by mapping each element to a triple and splitting them into three separate Traversable collections.
Traversable<V>	values()	Returns a Traversable containing all the values of this Multimap.
default <U> Seq<Tuple2<Tuple2<K,V>, U>>	zip(@NonNull Iterable<? extends U> that)	Returns a Traversable formed by pairing elements of this Traversable with elements of another Iterable.
default <U> Seq<Tuple2<Tuple2<K,V>, U>>	zipAll(@NonNull Iterable<? extends U> that, Tuple2<K,V> thisElem, U thatElem)	Returns a Traversable formed by pairing elements of this Traversable with elements of another Iterable, filling in placeholder elements when one collection is shorter than the other.
default <U,R> Seq<R>	zipWith(@NonNull Iterable<? extends U> that, BiFunction<? super Tuple2<K,V>, ? super U, ? extends R> mapper)	Returns a Traversable by combining elements of this Traversable with elements of another Iterable using a mapping function.
default Seq<Tuple2<Tuple2<K,V>, Integer>>	zipWithIndex()	Zips this Traversable with its indices, starting at 0.
default <U> Seq<U>	zipWithIndex(@NonNull BiFunction<? super Tuple2<K,V>, ? super Integer, ? extends U> mapper)	Zips this Traversable with its indices and maps the resulting pairs using the provided mapper.

Methods inherited from interface Foldable

fold, reduce, reduceOption

Methods inherited from interface Function1

andThen, arity, compose, compose1, curried, isMemoized, memoized, partial, reversed, tupled

Methods inherited from interface PartialFunction

lift

Methods inherited from interface Traversable

arrangeBy, average, containsAll, count, equals, existsUnique, find, findLast, foldLeft, forEachWithIndex, get, hashCode, head, headOption, isEmpty, isOrdered, isSequential, isSingleValued, last, lastOption, max, maxBy, maxBy, min, minBy, minBy, mkCharSeq, mkCharSeq, mkCharSeq, mkString, mkString, mkString, nonEmpty, product, reduceLeft, reduceLeftOption, reduceRight, reduceRightOption, single, singleOption, spliterator, sum

Methods inherited from interface Value

collect, collect, corresponds, eq, exists, forAll, forEach, getOrElse, getOrElse, getOrElseThrow, getOrElseTry, getOrNull, isAsync, isLazy, out, out, stderr, stdout, stringPrefix, 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

Field Details

serialVersionUID

static final long serialVersionUID

The serial version UID for serialization.

See Also:

• Constant Field Values

Method Details

narrow

static <K,V> Multimap<K,V> narrow(Multimap<? extends K, ? extends V> map)

Narrows a widened Multimap<? extends K, ? extends V> to Multimap<K, V> by performing a type-safe cast. This is eligible because immutable/read-only collections are covariant.

Type Parameters:

K - Key type

V - Value type

Parameters:

map - A Multimap.

Returns:

the given multimap instance as narrowed type Multimap<K, V>.

apply

@Deprecated
default Traversable<V> apply(K key)

Deprecated.

Description copied from interface: PartialFunction

Applies this function to the given argument and returns the result.

Specified by:

apply in interface Function<K,V>

Specified by:

apply in interface Function1<K,V>

Specified by:

apply in interface PartialFunction<K,V>

Parameters:

key - the input argument

Returns:

the result of applying this function to the input

asMap

Map<K, Traversable<V>> asMap()

Converts this Multimap to a Map

Returns:

Map<K, Traversable<V>>

asPartialFunction

default PartialFunction<K, Traversable<V>> asPartialFunction()
                                                      throws IndexOutOfBoundsException

Turns this Multimap into a PartialFunction which is defined at a specific index, if this Multimap contains the given key. When applied to a defined key, the partial function will return the Traversable of this Multimap that is associated with the key.

Returns:

a new PartialFunction

Throws:

NoSuchElementException - when a non-existing key is applied to the partial function

IndexOutOfBoundsException

bimap

<K2,V2> Multimap<K2,V2> bimap(Function<? super K, ? extends K2> keyMapper,
 Function<? super V, ? extends V2> valueMapper)

Maps this Multimap to a new Multimap with different component type by applying a function to its elements.

Type Parameters:

K2 - key's component type of the multimap result

V2 - value's component type of the multimap result

Parameters:

keyMapper - a Function that maps the keys of type K to keys of type K2

valueMapper - a Function that the values of type V to values of type V2

Returns:

a new Multimap

Throws:

NullPointerException - if keyMapper or valueMapper is null

collect

default <R> Seq<R> collect(@NonNull PartialFunction<? super Tuple2<K,V>, ? extends R> partialFunction)

Description copied from interface: Traversable

Applies a PartialFunction to all elements that are defined for it and collects the results.

For each element in iteration order, the function is first tested:

partialFunction.isDefinedAt(element)

If true, the element is mapped to type R:

R newElement = partialFunction.apply(element)

Note: If this Traversable is ordered (i.e., extends Ordered), the caller must ensure that the resulting elements are comparable (i.e., implement Comparable).

Specified by:

collect in interface Traversable<K>

Type Parameters:

R - the type of elements in the resulting Traversable

Parameters:

partialFunction - a function that may not be defined for all elements of this traversable

Returns:

a new Traversable containing the results of applying the partial function

contains

default boolean contains(@NonNull Tuple2<K,V> element)

Description copied from interface: Value

Shortcut for exists(e -> Objects.equals(e, element)), tests if the given element is contained.

Specified by:

contains in interface Value<K>

Parameters:

element - An Object of type A, may be null.

Returns:

true, if element is contained, false otherwise.

containsKey

boolean containsKey(K key)

Returns true if this multimap contains a mapping for the specified key.

Parameters:

key - key whose presence in this multimap is to be tested

Returns:

true if this multimap contains a mapping for the specified key

containsValue

default boolean containsValue(V value)

Returns true if this multimap maps one or more keys to the specified value. This operation will require time linear in the map size.

Parameters:

value - value whose presence in this multimap is to be tested

Returns:

true if this multimap maps one or more keys to the specified value

filter

Multimap<K,V> filter(@NonNull BiPredicate<? super K, ? super V> predicate)

Returns a new Multimap consisting of all elements which satisfy the given predicate.

Parameters:

predicate - the predicate used to test elements

Returns:

a new Multimap

Throws:

NullPointerException - if predicate is null

reject

Multimap<K,V> reject(@NonNull BiPredicate<? super K, ? super V> predicate)

Returns a new Multimap consisting of all elements which do not satisfy the given predicate.

Parameters:

predicate - the predicate used to test elements

Returns:

a new Multimap

Throws:

NullPointerException - if predicate is null

filterKeys

Multimap<K,V> filterKeys(@NonNull Predicate<? super K> predicate)

Returns a new Multimap consisting of all elements with keys which satisfy the given predicate.

Parameters:

predicate - the predicate used to test keys of elements

Returns:

a new Multimap

Throws:

NullPointerException - if predicate is null

rejectKeys

Multimap<K,V> rejectKeys(@NonNull Predicate<? super K> predicate)

Returns a new Multimap consisting of all elements with keys which do not satisfy the given predicate.

Parameters:

predicate - the predicate used to test keys of elements

Returns:

a new Multimap

Throws:

NullPointerException - if predicate is null

filterValues

Multimap<K,V> filterValues(@NonNull Predicate<? super V> predicate)

Returns a new Multimap consisting of all elements with values which satisfy the given predicate.

Parameters:

predicate - the predicate used to test values of elements

Returns:

a new Multimap

Throws:

NullPointerException - if predicate is null

rejectValues

Multimap<K,V> rejectValues(@NonNull Predicate<? super V> predicate)

Returns a new Multimap consisting of all elements with values which do not satisfy the given predicate.

Parameters:

predicate - the predicate used to test values of elements

Returns:

a new Multimap

Throws:

NullPointerException - if predicate is null

flatMap

<K2,V2> Multimap<K2,V2> flatMap(@NonNull BiFunction<? super K, ? super V, ? extends Iterable<Tuple2<K2,V2>>> mapper)

FlatMaps this Multimap to a new Multimap with different component type.

Type Parameters:

K2 - key's component type of the mapped Multimap

V2 - value's component type of the mapped Multimap

Parameters:

mapper - A mapper

Returns:

A new Multimap.

Throws:

NullPointerException - if mapper is null

forEach

default void forEach(@NonNull BiConsumer<K,V> action)

Performs an action on key, value pair.

Parameters:

action - A BiConsumer

Throws:

NullPointerException - if action is null

get

Option<Traversable<V>> get(K key)

Returns the Some of value to which the specified key is mapped, or None if this multimap contains no mapping for the key.

Parameters:

key - the key whose associated value is to be returned

Returns:

the Some of value to which the specified key is mapped, or None if this multimap contains no mapping for the key

getOrElse

Traversable<V> getOrElse(K key,
 Traversable<? extends V> defaultValue)

Returns the value associated with a key, or a default value if the key is not contained in the map

Parameters:

key - the key

defaultValue - a default value

Returns:

the value associated with key if it exists, otherwise the result of the default value

getContainerType

Multimap.ContainerType getContainerType()

Returns the type of the Traversable value container of this MultiMap.

Returns:

an enum value representing the container type

hasDefiniteSize

default boolean hasDefiniteSize()

Description copied from interface: Traversable

Indicates whether this Traversable has a known finite size.

This should typically be implemented by concrete classes, not interfaces.

Specified by:

hasDefiniteSize in interface Traversable<K>

Returns:

true if the number of elements is finite and known, false otherwise.

isDefinedAt

@Deprecated
default boolean isDefinedAt(K key)

Deprecated.

Description copied from interface: PartialFunction

Tests whether a value is contained in the function's domain.

Specified by:

isDefinedAt in interface PartialFunction<K,V>

Parameters:

key - a potential input to the function

Returns:

true if the given value is contained in the function's domain, false otherwise

isDistinct

default boolean isDistinct()

Description copied from interface: Traversable

Indicates whether this Traversable may contain only distinct elements.

Specified by:

isDistinct in interface Traversable<K>

Returns:

true if this Traversable may contain only distinct elements, false otherwise

isTraversableAgain

default boolean isTraversableAgain()

Description copied from interface: Traversable

Checks if this Traversable can be traversed multiple times without side effects.

Implementations should provide the correct behavior; this is not meant for interfaces alone.

Specified by:

isTraversableAgain in interface Traversable<K>

Returns:

true if this Traversable is guaranteed to be repeatably traversable, false otherwise

iterator

@NonNull Iterator<Tuple2<K,V>> iterator()

Description copied from interface: Traversable

Returns an iterator over the elements of this Traversable, implemented via Traversable.head() and Traversable.tail(). Subclasses may override for a more efficient implementation.

Specified by:

iterator in interface Iterable<K>

Specified by:

iterator in interface Traversable<K>

Specified by:

iterator in interface Value<K>

Returns:

a new Iterator over the elements of this Traversable

iterator

default <U> Iterator<U> iterator(@NonNull BiFunction<K, V, ? extends U> mapper)

Iterates this Multimap sequentially, mapping the (key, value) pairs to elements.

Type Parameters:

U - The type of the resulting elements

Parameters:

mapper - A function that maps (key, value) pairs to elements of type U

Returns:

An iterator through the mapped elements.

keySet

Set<K> keySet()

Returns the keys contained in this multimap.

Returns:

Set of the keys contained in this multimap.

length

default int length()

Description copied from interface: Traversable

Returns the number of elements in this Traversable.

Equivalent to Traversable.size().

Specified by:

length in interface Traversable<K>

Returns:

the number of elements

map

<K2,V2> Multimap<K2,V2> map(@NonNull BiFunction<? super K, ? super V, Tuple2<K2,V2>> mapper)

Maps the entries of this Multimap to form a new Multimap.

Type Parameters:

K2 - key's component type of the multimap result

V2 - value's component type of the multimap result

Parameters:

mapper - a Function that maps entries of type (K, V) to entries of type (K2, V2)

Returns:

a new Multimap

Throws:

NullPointerException - if mapper is null

map

default <U> Seq<U> map(@NonNull Function<? super Tuple2<K,V>, ? extends U> mapper)

Maps the Multimap entries to a sequence of values.

Please use map(BiFunction) if the result has to be of type Multimap.

Specified by:

map in interface Traversable<K>

Specified by:

map in interface Value<K>

Type Parameters:

U - Component type

Parameters:

mapper - A mapper

Returns:

A sequence of mapped values.

mapTo

default <U> Seq<U> mapTo(U value)

Description copied from interface: Value

Maps the underlying value to another fixed value.

Specified by:

mapTo in interface Traversable<K>

Specified by:

mapTo in interface Value<K>

Type Parameters:

U - The new component type

Parameters:

value - value to replace the contents with

Returns:

A new value

mapToVoid

default Seq<Void> mapToVoid()

Description copied from interface: Value

Maps the underlying value to Void

Specified by:

mapToVoid in interface Traversable<K>

Specified by:

mapToVoid in interface Value<K>

Returns:

A new value of type Void

mapValues

<V2> Multimap<K,V2> mapValues(@NonNull Function<? super V, ? extends V2> valueMapper)

Maps the values of this Multimap while preserving the corresponding keys.

Type Parameters:

V2 - the new value type

Parameters:

valueMapper - a Function that maps values of type V to values of type V2

Returns:

a new Multimap

Throws:

NullPointerException - if valueMapper is null

merge

Multimap<K,V> merge(@NonNull Multimap<? extends K, ? extends V> that)

Creates a new multimap which by merging the entries of this multimap and that multimap.

If collisions occur, the value of this multimap is taken.

Parameters:

that - the other multimap

Returns:

A merged multimap

Throws:

NullPointerException - if that multimap is null

merge

<K2 extends K, V2 extends V> Multimap<K,V> merge(@NonNull Multimap<K2,V2> that,
 @NonNull BiFunction<Traversable<V>, Traversable<V2>, Traversable<V>> collisionResolution)

Creates a new multimap which by merging the entries of this multimap and that multimap.

Uses the specified collision resolution function if two keys are the same. The collision resolution function will always take the first argument from this multimap and the second from that multimap.

Type Parameters:

K2 - key type of that Multimap

V2 - value type of that Multimap

Parameters:

that - the other multimap

collisionResolution - the collision resolution function

Returns:

A merged multimap

Throws:

NullPointerException - if that multimap or the given collision resolution function is null

put

Multimap<K,V> put(K key,
 V value)

Associates the specified value with the specified key in this multimap. If the map previously contained a mapping for the key, the old value is replaced by the specified value.

Parameters:

key - key with which the specified value is to be associated

value - value to be associated with the specified key

Returns:

A new Multimap containing these elements and that entry.

put

Multimap<K,V> put(@NonNull Tuple2<? extends K, ? extends V> entry)

Convenience method for put(entry._1, entry._2).

Parameters:

entry - A Tuple2 containing the key and value

Returns:

A new Multimap containing these elements and that entry.

remove

Multimap<K,V> remove(K key)

Removes the mapping for a key from this multimap if it is present.

Parameters:

key - key whose mapping is to be removed from the multimap

Returns:

A new Multimap containing these elements without the entry specified by that key.

remove

Multimap<K,V> remove(K key,
 V value)

Removes the key-value pair from this multimap if it is present.

Parameters:

key - key whose mapping is to be removed from the multimap

value - value whose mapping is to be removed from the multimap

Returns:

A new Multimap containing these elements without the entry specified by that key and value.

removeAll

@Deprecated
Multimap<K,V> removeAll(@NonNull BiPredicate<? super K, ? super V> predicate)

Deprecated.

Please use reject(BiPredicate)

Returns a new Multimap consisting of all elements which do not satisfy the given predicate.

Parameters:

predicate - the predicate used to test elements

Returns:

a new Multimap

Throws:

NullPointerException - if predicate is null

removeAll

Multimap<K,V> removeAll(@NonNull Iterable<? extends K> keys)

Removes the mapping for a key from this multimap if it is present.

Parameters:

keys - keys are to be removed from the multimap

Returns:

A new Multimap containing these elements without the entries specified by that keys.

removeKeys

@Deprecated
Multimap<K,V> removeKeys(@NonNull Predicate<? super K> predicate)

Deprecated.

Please use rejectKeys(Predicate)

Returns a new Multimap consisting of all elements with keys which do not satisfy the given predicate.

Parameters:

predicate - the predicate used to test keys of elements

Returns:

a new Multimap

Throws:

NullPointerException - if predicate is null

removeValues

@Deprecated
Multimap<K,V> removeValues(@NonNull Predicate<? super V> predicate)

Deprecated.

Please use rejectValues(Predicate)

Returns a new Multimap consisting of all elements with values which do not satisfy the given predicate.

Parameters:

predicate - the predicate used to test values of elements

Returns:

a new Multimap

Throws:

NullPointerException - if predicate is null

scanLeft

default <U> Seq<U> scanLeft(U zero,
 @NonNull BiFunction<? super U, ? super Tuple2<K,V>, ? extends U> operation)

Description copied from interface: Traversable

Produces a collection containing cumulative results of applying the operator from left to right.

Will not terminate for infinite collections. The results may vary across runs unless the collection is ordered.

Specified by:

scanLeft in interface Traversable<K>

Type Parameters:

U - the type of the resulting elements

Parameters:

zero - the initial value

operation - a binary operator applied to the intermediate result and each element

Returns:

a new Traversable containing the cumulative results

scanRight

default <U> Seq<U> scanRight(U zero,
 @NonNull BiFunction<? super Tuple2<K,V>, ? super U, ? extends U> operation)

Description copied from interface: Traversable

Produces a collection containing cumulative results of applying the operator from right to left.

The head of the resulting collection is the last cumulative result. Will not terminate for infinite collections. Results may vary across runs unless the collection is ordered.

Specified by:

scanRight in interface Traversable<K>

Type Parameters:

U - the type of the resulting elements

Parameters:

zero - the initial value

operation - a binary operator applied to each element and the intermediate result

Returns:

a new Traversable containing the cumulative results

size

int size()

Description copied from interface: Traversable

Returns the number of elements in this Traversable.

Alias for Traversable.length().

Specified by:

size in interface Traversable<K>

Returns:

the number of elements

toJavaMap

Map<K, Collection<V>> toJavaMap()

Converts this Vavr Map to a java.util.Map while preserving characteristics like insertion order (LinkedHashMultimap) and sort order (SortedMultimap).

Returns:

a new java.util.Map instance

transform

default <U> U transform(@NonNull Function<? super Multimap<K,V>, ? extends U> f)

Transforms this Multimap.

Type Parameters:

U - Type of transformation result

Parameters:

f - A transformation

Returns:

An instance of type U

Throws:

NullPointerException - if f is null

unzip

default <T1,T2> Tuple2<Seq<T1>,Seq<T2>> unzip(@NonNull BiFunction<? super K, ? super V, Tuple2<? extends T1, ? extends T2>> unzipper)

Unzips the entries of this Multimap by mapping each key-value pair to a pair and splitting them into two separate Seq collections.

Type Parameters:

T1 - type of the first element in the resulting pairs

T2 - type of the second element in the resulting pairs

Parameters:

unzipper - a function that maps keys and values of this Multimap to pairs

Returns:

a Tuple2 containing two Seq collections with the split elements

Throws:

NullPointerException - if unzipper is null

unzip

default <T1,T2> Tuple2<Seq<T1>,Seq<T2>> unzip(@NonNull Function<? super Tuple2<K,V>, Tuple2<? extends T1, ? extends T2>> unzipper)

Description copied from interface: Traversable

Unzips the elements of this Traversable by mapping each element to a pair and splitting them into two separate Traversable collections.

Specified by:

unzip in interface Traversable<K>

Type Parameters:

T1 - type of the first element in the resulting pairs

T2 - type of the second element in the resulting pairs

Parameters:

unzipper - a function that maps elements of this Traversable to pairs

Returns:

a Tuple2 containing two Traversable collections with the split elements

unzip3

default <T1,T2,T3> Tuple3<Seq<T1>,Seq<T2>,Seq<T3>> unzip3(@NonNull BiFunction<? super K, ? super V, Tuple3<? extends T1, ? extends T2, ? extends T3>> unzipper)

Unzips the entries of this Multimap by mapping each key-value pair to a triple and splitting them into three separate Seq collections.

Type Parameters:

T1 - type of the first element in the resulting triples

T2 - type of the second element in the resulting triples

T3 - type of the third element in the resulting triples

Parameters:

unzipper - a function that maps keys and values of this Multimap to triples

Returns:

a Tuple3 containing three Seq collections with the split elements

Throws:

NullPointerException - if unzipper is null

unzip3

default <T1,T2,T3> Tuple3<Seq<T1>,Seq<T2>,Seq<T3>> unzip3(@NonNull Function<? super Tuple2<K,V>, Tuple3<? extends T1, ? extends T2, ? extends T3>> unzipper)

Description copied from interface: Traversable

Unzips the elements of this Traversable by mapping each element to a triple and splitting them into three separate Traversable collections.

Specified by:

unzip3 in interface Traversable<K>

Type Parameters:

T1 - type of the first element in the resulting triples

T2 - type of the second element in the resulting triples

T3 - type of the third element in the resulting triples

Parameters:

unzipper - a function that maps elements of this Traversable to triples

Returns:

a Tuple3 containing three Traversable collections with the split elements

values

Traversable<V> values()

Returns a Traversable containing all the values of this Multimap.

Returns:

a new Traversable

zip

default <U> Seq<Tuple2<Tuple2<K,V>, U>> zip(@NonNull Iterable<? extends U> that)

Description copied from interface: Traversable

Returns a Traversable formed by pairing elements of this Traversable with elements of another Iterable. Pairing stops when either collection runs out of elements; any remaining elements in the longer collection are ignored.

The length of the resulting Traversable is the minimum of the lengths of this Traversable and that.

Specified by:

zip in interface Traversable<K>

Type Parameters:

U - the type of elements in the second half of each pair

Parameters:

that - an Iterable providing the second element of each pair

Returns:

a new Traversable containing pairs of corresponding elements

zipAll

default <U> Seq<Tuple2<Tuple2<K,V>, U>> zipAll(@NonNull Iterable<? extends U> that,
 Tuple2<K,V> thisElem,
 U thatElem)

Description copied from interface: Traversable

Returns a Traversable formed by pairing elements of this Traversable with elements of another Iterable, filling in placeholder elements when one collection is shorter than the other.

The length of the resulting Traversable is the maximum of the lengths of this Traversable and that.

If this Traversable is shorter than that, thisElem is used as a filler. Conversely, if that is shorter, thatElem is used.

Specified by:

zipAll in interface Traversable<K>

Type Parameters:

U - the type of elements in the second half of each pair

Parameters:

that - an Iterable providing the second element of each pair

thisElem - the element used to fill missing values if this Traversable is shorter than that

thatElem - the element used to fill missing values if that is shorter than this Traversable

Returns:

a new Traversable containing pairs of elements, including fillers as needed

zipWith

default <U,R> Seq<R> zipWith(@NonNull Iterable<? extends U> that,
 BiFunction<? super Tuple2<K,V>, ? super U, ? extends R> mapper)

Description copied from interface: Traversable

Returns a Traversable by combining elements of this Traversable with elements of another Iterable using a mapping function. Pairing stops when either collection runs out of elements.

The length of the resulting Traversable is the minimum of the lengths of this Traversable and that.

Specified by:

zipWith in interface Traversable<K>

Type Parameters:

U - the type of elements in the second parameter of the mapper

R - the type of elements in the resulting Traversable

Parameters:

that - an Iterable providing the second parameter of the mapper

mapper - a function that combines elements from this and that into a new element

Returns:

a new Traversable containing mapped elements

zipWithIndex

default Seq<Tuple2<Tuple2<K,V>, Integer>> zipWithIndex()

Description copied from interface: Traversable

Zips this Traversable with its indices, starting at 0.

Specified by:

zipWithIndex in interface Traversable<K>

Returns:

a new Traversable containing each element paired with its index

zipWithIndex

default <U> Seq<U> zipWithIndex(@NonNull BiFunction<? super Tuple2<K,V>, ? super Integer, ? extends U> mapper)

Description copied from interface: Traversable

Zips this Traversable with its indices and maps the resulting pairs using the provided mapper.

Specified by:

zipWithIndex in interface Traversable<K>

Type Parameters:

U - the type of elements in the resulting Traversable

Parameters:

mapper - a function mapping an element and its index to a new element

Returns:

a new Traversable containing the mapped elements

distinct

Multimap<K,V> distinct()

Description copied from interface: Traversable

Returns a new Traversable containing the elements of this instance with all duplicates removed. Element equality is determined using equals.

Specified by:

distinct in interface Traversable<K>

Returns:

a new Traversable without duplicate elements

distinctBy

Multimap<K,V> distinctBy(@NonNull Comparator<? super Tuple2<K,V>> comparator)

Description copied from interface: Traversable

Returns a new Traversable containing the elements of this instance without duplicates, as determined by the given comparator.

Specified by:

distinctBy in interface Traversable<K>

Parameters:

comparator - a comparator used to determine equality of elements

Returns:

a new Traversable with duplicates removed

distinctBy

<U> Multimap<K,V> distinctBy(@NonNull Function<? super Tuple2<K,V>, ? extends U> keyExtractor)

Description copied from interface: Traversable

Returns a new Traversable containing the elements of this instance without duplicates, based on keys extracted from elements using keyExtractor.

The first occurrence of each key is retained in the resulting sequence.

Specified by:

distinctBy in interface Traversable<K>

Type Parameters:

U - the type of key

Parameters:

keyExtractor - a function to extract keys for determining uniqueness

Returns:

a new Traversable with duplicates removed based on keys

drop

Multimap<K,V> drop(int n)

Description copied from interface: Traversable

Returns a new Traversable without the first n elements, or an empty instance if this contains fewer than n elements.

Specified by:

drop in interface Traversable<K>

Parameters:

n - the number of elements to drop

Returns:

a new instance excluding the first n elements

dropRight

Multimap<K,V> dropRight(int n)

Description copied from interface: Traversable

Returns a new Traversable without the last n elements, or an empty instance if this contains fewer than n elements.

Specified by:

dropRight in interface Traversable<K>

Parameters:

n - the number of elements to drop from the end

Returns:

a new instance excluding the last n elements

dropUntil

Multimap<K,V> dropUntil(@NonNull Predicate<? super Tuple2<K,V>> predicate)

Description copied from interface: Traversable

Returns a new Traversable starting from the first element that satisfies the given predicate, dropping all preceding elements.

Specified by:

dropUntil in interface Traversable<K>

Parameters:

predicate - a condition tested on each element

Returns:

a new instance starting from the first element matching the predicate

dropWhile

Multimap<K,V> dropWhile(@NonNull Predicate<? super Tuple2<K,V>> predicate)

Description copied from interface: Traversable

Returns a new Traversable starting from the first element that does not satisfy the given predicate, dropping all preceding elements.

This is equivalent to dropUntil(predicate.negate()), which is useful for method references that cannot be negated directly.

Specified by:

dropWhile in interface Traversable<K>

Parameters:

predicate - a condition tested on each element

Returns:

a new instance starting from the first element not matching the predicate

filter

Multimap<K,V> filter(@NonNull Predicate<? super Tuple2<K,V>> predicate)

Description copied from interface: Traversable

Returns a new traversable containing only the elements that satisfy the given predicate.

Specified by:

filter in interface Traversable<K>

Parameters:

predicate - the condition to test elements

Returns:

a traversable with elements matching the predicate

reject

Multimap<K,V> reject(@NonNull Predicate<? super Tuple2<K,V>> predicate)

Description copied from interface: Traversable

Returns a new traversable containing only the elements that do not satisfy the given predicate.

This is equivalent to filter(predicate.negate()).

Specified by:

reject in interface Traversable<K>

Parameters:

predicate - the condition to test elements

Returns:

a traversable with elements not matching the predicate

flatMap

default <U> Seq<U> flatMap(@NonNull Function<? super Tuple2<K,V>, ? extends Iterable<? extends U>> mapper)

Flat-maps this entries to a sequence of values.

Please use flatMap(BiFunction) if the result should be a Multimap

Specified by:

flatMap in interface Traversable<K>

Type Parameters:

U - Component type

Parameters:

mapper - A mapper

Returns:

A sequence of flat-mapped values.

foldRight

default <U> U foldRight(U zero,
 @NonNull BiFunction<? super Tuple2<K,V>, ? super U, ? extends U> f)

Description copied from interface: Foldable

Folds the elements of this structure from the right, starting with the given zero value and successively applying the combine function to each element.

Folding from the right means that elements are combined starting from the last element and associating each step with the accumulated result so far.

Example:

// Result: "!cba"
List.of("a", "b", "c").foldRight("!", (x, acc) -> acc + x);

Specified by:

foldRight in interface Foldable<K>

Specified by:

foldRight in interface Traversable<K>

Type Parameters:

U - the type of the accumulated result

Parameters:

zero - the initial value to start folding with

f - a function that combines the next element and the accumulated value

Returns:

the folded result

groupBy

<C> Map<C, ? extends Multimap<K,V>> groupBy(@NonNull Function<? super Tuple2<K,V>, ? extends C> classifier)

Description copied from interface: Traversable

Groups elements of this Traversable based on a classifier function.

Specified by:

groupBy in interface Traversable<K>

Type Parameters:

C - The type of the group keys

Parameters:

classifier - A function that assigns each element to a group

Returns:

A map where each key corresponds to a group of elements

See Also:

• Traversable.arrangeBy(Function)

grouped

Iterator<? extends Multimap<K,V>> grouped(int size)

Description copied from interface: Traversable

Splits this Traversable into consecutive blocks of the given size.

Let length be the number of elements in this Traversable:

• If empty, the resulting Iterator is empty.
• If size <= length, the resulting Iterator contains length / size blocks of size size and possibly a final smaller block of size length % size.
• If size > length, the resulting Iterator contains a single block of size length.

Examples:

[].grouped(1) = []
[].grouped(0) throws
[].grouped(-1) throws
[1,2,3,4].grouped(2) = [[1,2],[3,4]]
[1,2,3,4,5].grouped(2) = [[1,2],[3,4],[5]]
[1,2,3,4].grouped(5) = [[1,2,3,4]]

Note: grouped(size) is equivalent to sliding(size, size).

Specified by:

grouped in interface Traversable<K>

Parameters:

size - the block size; must be positive

Returns:

an Iterator over blocks of elements

init

Multimap<K,V> init()

Description copied from interface: Traversable

Returns all elements of this Traversable except the last one.

This is the dual of Traversable.tail().

Specified by:

init in interface Traversable<K>

Returns:

a new instance containing all elements except the last

initOption

Option<? extends Multimap<K,V>> initOption()

Description copied from interface: Traversable

Returns all elements of this Traversable except the last one, wrapped in an Option.

This is the dual of Traversable.tailOption().

Specified by:

initOption in interface Traversable<K>

Returns:

Some(traversable) if non-empty, or None if this Traversable is empty

orElse

Multimap<K,V> orElse(Iterable<? extends Tuple2<K,V>> other)

Description copied from interface: Traversable

Returns this Traversable if it is non-empty; otherwise, returns the given alternative.

Specified by:

orElse in interface Traversable<K>

Parameters:

other - an alternative Traversable to return if this is empty

Returns:

this Traversable if non-empty, otherwise other

orElse

Multimap<K,V> orElse(@NonNull Supplier<? extends Iterable<? extends Tuple2<K,V>>> supplier)

Description copied from interface: Traversable

Returns this Traversable if it is non-empty; otherwise, returns the result of evaluating the given supplier.

Specified by:

orElse in interface Traversable<K>

Parameters:

supplier - a supplier of an alternative Traversable if this is empty

Returns:

this Traversable if non-empty, otherwise the result of supplier.get()

partition

Tuple2<? extends Multimap<K,V>, ? extends Multimap<K,V>> partition(@NonNull Predicate<? super Tuple2<K,V>> predicate)

Description copied from interface: Traversable

Splits this Traversable into two partitions according to a predicate.

The first partition contains all elements that satisfy the predicate, and the second contains all elements that do not. The original iteration order is preserved.

Specified by:

partition in interface Traversable<K>

Parameters:

predicate - a predicate used to classify elements

Returns:

a Tuple2 containing the two resulting Traversable instances

peek

Multimap<K,V> peek(@NonNull Consumer<? super Tuple2<K,V>> action)

Description copied from interface: Value

Performs the given action on the first element if this is an eager implementation. Performs the given action on all elements (the first immediately, successive deferred), if this is a lazy implementation.

Specified by:

peek in interface Traversable<K>

Specified by:

peek in interface Value<K>

Parameters:

action - The action that will be performed on the element(s).

Returns:

this instance

replace

Multimap<K,V> replace(Tuple2<K,V> currentElement,
 Tuple2<K,V> newElement)

Description copied from interface: Traversable

Replaces the first occurrence of currentElement with newElement, if it exists.

Specified by:

replace in interface Traversable<K>

Parameters:

currentElement - the element to be replaced

newElement - the replacement element

Returns:

a new Traversable with the first occurrence of currentElement replaced by newElement

replaceAll

Multimap<K,V> replaceAll(Tuple2<K,V> currentElement,
 Tuple2<K,V> newElement)

Description copied from interface: Traversable

Replaces all occurrences of currentElement with newElement.

Specified by:

replaceAll in interface Traversable<K>

Parameters:

currentElement - the element to be replaced

newElement - the replacement element

Returns:

a new Traversable with all occurrences of currentElement replaced by newElement

replaceValue

Multimap<K,V> replaceValue(K key,
 V value)

Replaces the entry for the specified key only if it is currently mapped to some value.

Parameters:

key - the key of the element to be substituted

value - the new value to be associated with the key

Returns:

a new map containing key mapped to value if key was contained before. The old map otherwise

replace

Multimap<K,V> replace(K key,
 V oldValue,
 V newValue)

Replaces the entry with the specified key and oldValue.

Parameters:

key - the key of the element to be substituted

oldValue - the expected current value associated with the key

newValue - the new value to be associated with the key

Returns:

a new map containing key mapped to newValue if key was contained before and oldValue was associated with the key. The old map otherwise.

replaceAll

Multimap<K,V> replaceAll(@NonNull BiFunction<? super K, ? super V, ? extends V> function)

Replaces each entry's values with the result of invoking the given function on that each tuple until all entries have been processed or the function throws an exception.

Parameters:

function - function transforming key and current value to a new value

Returns:

a new map with the same keySet but transformed values

retainAll

Multimap<K,V> retainAll(@NonNull Iterable<? extends Tuple2<K,V>> elements)

Description copied from interface: Traversable

Retains only the elements from this Traversable that are contained in the given elements.

Specified by:

retainAll in interface Traversable<K>

Parameters:

elements - the elements to keep

Returns:

a new Traversable containing only the elements present in elements, in their original order

scan

Multimap<K,V> scan(Tuple2<K,V> zero,
 @NonNull BiFunction<? super Tuple2<K,V>, ? super Tuple2<K,V>, ? extends Tuple2<K,V>> operation)

Description copied from interface: Traversable

Computes a prefix scan of the elements of this Traversable.

The neutral element zero may be applied more than once.

Specified by:

scan in interface Traversable<K>

Parameters:

zero - the neutral element for the operator

operation - an associative binary operator

Returns:

a new Traversable containing the prefix scan of the elements

slideBy

Iterator<? extends Multimap<K,V>> slideBy(@NonNull Function<? super Tuple2<K,V>, ?> classifier)

Description copied from interface: Traversable

Partitions this Traversable into consecutive non-overlapping windows according to a classification function.

Each window contains elements with the same class, as determined by classifier. Two consecutive elements belong to the same window only if classifier returns equal values for both. Otherwise, the current window ends and a new window begins with the next element.

Examples:

[].slideBy(Function.identity()) = []
[1,2,3,4,4,5].slideBy(Function.identity()) = [[1],[2],[3],[4,4],[5]]
[1,2,3,10,12,5,7,20,29].slideBy(x -> x / 10) = [[1,2,3],[10,12],[5,7],[20,29]]

Specified by:

slideBy in interface Traversable<K>

Parameters:

classifier - A function classifying elements into groups

Returns:

An Iterator of windows (grouped elements)

sliding

Iterator<? extends Multimap<K,V>> sliding(int size)

Description copied from interface: Traversable

Slides a window of a given size over this Traversable with a step size of 1.

This is equivalent to calling Traversable.sliding(int, int) with a step size of 1.

Specified by:

sliding in interface Traversable<K>

Parameters:

size - a positive window size

Returns:

An Iterator of windows, each containing up to size elements

sliding

Iterator<? extends Multimap<K,V>> sliding(int size,
 int step)

Description copied from interface: Traversable

Slides a window of a specific size with a given step over this Traversable.

Examples:

[].sliding(1, 1) = []
[1,2,3,4,5].sliding(2, 3) = [[1,2],[4,5]]
[1,2,3,4,5].sliding(2, 4) = [[1,2],[5]]
[1,2,3,4,5].sliding(2, 5) = [[1,2]]
[1,2,3,4].sliding(5, 3) = [[1,2,3,4],[4]]

Specified by:

sliding in interface Traversable<K>

Parameters:

size - a positive window size

step - a positive step size

Returns:

an Iterator of windows with the given size and step

span

Tuple2<? extends Multimap<K,V>, ? extends Multimap<K,V>> span(@NonNull Predicate<? super Tuple2<K,V>> predicate)

Description copied from interface: Traversable

Splits this Traversable into a prefix and remainder according to the given predicate.

The first element of the returned Tuple is the longest prefix of elements satisfying predicate, and the second element is the remaining elements.

Specified by:

span in interface Traversable<K>

Parameters:

predicate - a predicate used to determine the prefix

Returns:

a Tuple containing the prefix and remainder

tail

Multimap<K,V> tail()

Description copied from interface: Traversable

Returns a new Traversable without its first element.

Specified by:

tail in interface Traversable<K>

Returns:

a new Traversable containing all elements except the first

tailOption

Option<? extends Multimap<K,V>> tailOption()

Description copied from interface: Traversable

Returns a new Traversable without its first element as an Option.

Specified by:

tailOption in interface Traversable<K>

Returns:

Some(traversable) if non-empty, otherwise None

take

Multimap<K,V> take(int n)

Description copied from interface: Traversable

Returns the first n elements of this Traversable, or all elements if n exceeds the length.

Equivalent to sublist(0, max(0, min(length(), n))), but safe for n < 0 or n > length().

If n < 0, an empty instance is returned. If n > length(), the full instance is returned.

Specified by:

take in interface Traversable<K>

Parameters:

n - the number of elements to take

Returns:

a new Traversable containing the first n elements

takeRight

Multimap<K,V> takeRight(int n)

Description copied from interface: Traversable

Returns the last n elements of this Traversable, or all elements if n exceeds the length.

Equivalent to sublist(max(0, length() - n), length()), but safe for n < 0 or n > length().

If n < 0, an empty instance is returned. If n > length(), the full instance is returned.

Specified by:

takeRight in interface Traversable<K>

Parameters:

n - the number of elements to take from the end

Returns:

a new Traversable containing the last n elements

takeUntil

Multimap<K,V> takeUntil(@NonNull Predicate<? super Tuple2<K,V>> predicate)

Description copied from interface: Traversable

Takes elements from this Traversable until the given predicate holds for an element.

Equivalent to takeWhile(predicate.negate()), but useful when using method references that cannot be negated directly.

Specified by:

takeUntil in interface Traversable<K>

Parameters:

predicate - a condition tested sequentially on the elements

Returns:

a new Traversable containing all elements before the first one that satisfies the predicate

takeWhile

Multimap<K,V> takeWhile(@NonNull Predicate<? super Tuple2<K,V>> predicate)

Description copied from interface: Traversable

Takes elements from this Traversable while the given predicate holds.

Specified by:

takeWhile in interface Traversable<K>

Parameters:

predicate - a condition tested sequentially on the elements

Returns:

a new Traversable containing all elements up to (but not including) the first one that does not satisfy the predicate