Package io.vavr.collection

Class HashMultimap<K,V>

java.lang.Object

io.vavr.collection.AbstractMultimap<K,V,HashMultimap<K,V>>

io.vavr.collection.HashMultimap<K,V>

Type Parameters:

K - Key type

V - Value type

All Implemented Interfaces:

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

public final class HashMultimap<K,V>
extends AbstractMultimap<K,V,HashMultimap<K,V>>
implements Serializable

A HashMap-based implementation of Multimap

See Also:

• Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	HashMultimap.Builder<V>	Builder for creating HashMultimap instances with different container types.

Nested classes/interfaces inherited from class io.vavr.collection.AbstractMultimap

AbstractMultimap.SerializableSupplier<T>

Nested classes/interfaces inherited from interface io.vavr.collection.Multimap

Multimap.ContainerType

Field Summary

Fields

Modifier and Type	Field	Description
private static final long	serialVersionUID

Fields inherited from class io.vavr.collection.AbstractMultimap

back, emptyContainer

Constructor Summary

Constructors

Modifier	Constructor	Description
private	HashMultimap(Map<K,Traversable<V>> back, Multimap.ContainerType containerType, AbstractMultimap.SerializableSupplier<Traversable<?>> emptyContainer)

Method Summary

Modifier and Type	Method	Description
protected <K2, V2> HashMultimap<K2,V2>	createFromMap(Map<K2,Traversable<V2>> back)	Creates a new Multimap instance from the given backing map.
protected <K2, V2> HashMultimap<K2,V2>	emptyInstance()	Returns an empty Multimap instance specific to the implementing class.
protected <K2, V2> Map<K2,V2>	emptyMapSupplier()	Returns an empty Map instance specific to the implementing class.
static <K, V> HashMultimap<K,V>	narrow(HashMultimap<? extends K,? extends V> map)	Narrows a HashMultimap<? extends K, ? extends V> to HashMultimap<K, V> via a type-safe cast.
static <V> HashMultimap.Builder<V>	withSeq()	Returns a builder for HashMultimap instances where values are stored in a sequence.
static <V> HashMultimap.Builder<V>	withSet()	Returns a builder for HashMultimap instances where values are stored in a set.
static <V extends Comparable<?>> HashMultimap.Builder<V>	withSortedSet()	Returns a builder for HashMultimap instances where values are stored in a sorted set.
static <V> HashMultimap.Builder<V>	withSortedSet(Comparator<? super V> comparator)	Returns a builder for HashMultimap instances where values are stored in a sorted set with a custom comparator.

Methods inherited from class io.vavr.collection.AbstractMultimap

asMap, bimap, containsKey, distinct, distinctBy, distinctBy, drop, dropRight, dropUntil, dropWhile, equals, filter, filter, filterKeys, filterValues, flatMap, get, getContainerType, getOrElse, groupBy, grouped, hashCode, head, init, initOption, isAsync, isEmpty, isLazy, iterator, keySet, last, map, mapValues, merge, merge, orElse, orElse, partition, peek, put, put, reject, reject, rejectKeys, rejectValues, remove, remove, removeAll, removeAll, removeKeys, removeValues, replace, replace, replaceAll, replaceAll, replaceValue, retainAll, scan, size, slideBy, sliding, sliding, span, stringPrefix, tail, tailOption, take, takeRight, takeUntil, takeWhile, toJavaMap, toJavaMap, toString, values

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface io.vavr.collection.Foldable

fold, reduce, reduceOption

Methods inherited from interface io.vavr.Function1

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

Methods inherited from interface io.vavr.collection.Multimap

apply, asPartialFunction, collect, contains, containsValue, flatMap, foldRight, forEach, hasDefiniteSize, isDefinedAt, isDistinct, isTraversableAgain, iterator, length, map, mapTo, mapToVoid, scanLeft, scanRight, transform, unzip, unzip, unzip3, unzip3, zip, zipAll, zipWith, zipWithIndex, zipWithIndex

Methods inherited from interface io.vavr.PartialFunction

lift

Methods inherited from interface io.vavr.collection.Traversable

arrangeBy, average, containsAll, count, existsUnique, find, findLast, foldLeft, forEachWithIndex, get, headOption, isOrdered, isSequential, isSingleValued, 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 io.vavr.Value

collect, collect, 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, toTree, toTree, toTry, toTry, toValid, toValid, toValidation, toValidation, toVector

Field Details

serialVersionUID

private static final long serialVersionUID

See Also:

• Constant Field Values

Constructor Details

HashMultimap

private HashMultimap(Map<K,Traversable<V>> back,
 Multimap.ContainerType containerType,
 AbstractMultimap.SerializableSupplier<Traversable<?>> emptyContainer)

Method Details

withSeq

public static <V> HashMultimap.Builder<V> withSeq()

Returns a builder for HashMultimap instances where values are stored in a sequence. Values for each key will be stored in a Vavr List, allowing duplicates and preserving insertion order.

Type Parameters:

V - The value type

Returns:

A new Builder for creating HashMultimap instances with sequence-based value storage

withSet

public static <V> HashMultimap.Builder<V> withSet()

Returns a builder for HashMultimap instances where values are stored in a set. Values for each key will be stored in a Vavr HashSet, ensuring uniqueness without guaranteed order.

Type Parameters:

V - The value type

Returns:

A new Builder for creating HashMultimap instances with set-based value storage

withSortedSet

public static <V extends Comparable<?>>
HashMultimap.Builder<V> withSortedSet()

Returns a builder for HashMultimap instances where values are stored in a sorted set. Values for each key will be stored in a Vavr TreeSet, ensuring uniqueness and natural ordering. Value type must be Comparable.

Type Parameters:

V - The value type, must extend Comparable

Returns:

A new Builder for creating HashMultimap instances with sorted set-based value storage

withSortedSet

public static <V> HashMultimap.Builder<V> withSortedSet(Comparator<? super V> comparator)

Returns a builder for HashMultimap instances where values are stored in a sorted set with a custom comparator. Values for each key will be stored in a Vavr TreeSet, ensuring uniqueness and ordering based on the provided comparator.

Type Parameters:

V - The value type

Parameters:

comparator - The comparator used to sort values

Returns:

A new Builder for creating HashMultimap instances with sorted set-based value storage using the given comparator

narrow

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

Narrows a HashMultimap<? extends K, ? extends V> to HashMultimap<K, V> via a type-safe cast. Safe here because the multimap is immutable and no elements can be added that would violate the type (covariance)

Type Parameters:

K - the target key type

V - the target value type

Parameters:

map - the multimap to narrow

Returns:

the same multimap viewed as HashMultimap<K, V>

emptyMapSupplier

protected <K2,
V2> Map<K2,V2> emptyMapSupplier()

Description copied from class: AbstractMultimap

Returns an empty Map instance specific to the implementing class.

Specified by:

emptyMapSupplier in class AbstractMultimap<K,V,HashMultimap<K,V>>

Type Parameters:

K2 - Key type of the empty map

V2 - Value type of the empty map

Returns:

An empty Map instance

emptyInstance

protected <K2,
V2> HashMultimap<K2,V2> emptyInstance()

Description copied from class: AbstractMultimap

Returns an empty Multimap instance specific to the implementing class.

Specified by:

emptyInstance in class AbstractMultimap<K,V,HashMultimap<K,V>>

Type Parameters:

K2 - Key type of the empty multimap

V2 - Value type of the empty multimap

Returns:

An empty Multimap instance

createFromMap

protected <K2,
V2> HashMultimap<K2,V2> createFromMap(Map<K2,Traversable<V2>> back)

Description copied from class: AbstractMultimap

Creates a new Multimap instance from the given backing map.

Specified by:

createFromMap in class AbstractMultimap<K,V,HashMultimap<K,V>>

Type Parameters:

K2 - Key type of the new multimap

V2 - Value type of the new multimap

Parameters:

back - The backing map to create the multimap from

Returns:

A new Multimap instance containing the entries from the backing map