Class HashMultimap<K,V>

java.lang.Object

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 Object
implements Serializable

A HashMap-based implementation of Multimap

Author:

Ruslan Sennov

See Also:

• Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	HashMultimap.Builder<V>

Nested classes/interfaces inherited from interface Multimap

Multimap.ContainerType

Field Summary

Fields

Modifier and Type	Field	Description
protected final Map<K, Traversable<V>>	back
protected final io.vavr.collection.AbstractMultimap.SerializableSupplier<Traversable<?>>	emptyContainer

Method Summary

Modifier and Type	Method	Description
Map<K, Traversable<V>>	asMap()	Converts this Multimap to a Map
<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.
boolean	containsKey(K key)	Returns true if this multimap contains a mapping for the specified key.
protected <K2,V2> HashMultimap<K2,V2>	createFromMap(Map<K2, Traversable<V2>> back)
HashMultimap<K,V>	distinct()	Returns a new version of this which contains no duplicates.
HashMultimap<K,V>	distinctBy(Comparator<? super Tuple2<K,V>> comparator)	Returns a new version of this which contains no duplicates.
<U> HashMultimap<K,V>	distinctBy(Function<? super Tuple2<K,V>, ? extends U> keyExtractor)	Returns a new version of this which contains no duplicates.
HashMultimap<K,V>	drop(int n)	Drops the first n elements of this or all elements, if this length < n.
HashMultimap<K,V>	dropRight(int n)	Drops the last n elements of this or all elements, if this length < n.
HashMultimap<K,V>	dropUntil(Predicate<? super Tuple2<K,V>> predicate)	Drops elements until the predicate holds for the current element.
HashMultimap<K,V>	dropWhile(Predicate<? super Tuple2<K,V>> predicate)	Drops elements while the predicate holds for the current element.
protected <K2,V2> HashMultimap<K2,V2>	emptyInstance()
protected <K2,V2> Map<K2,V2>	emptyMapSupplier()
boolean	equals(Object o)	In Vavr there are four basic classes of collections: Seq (sequential elements) Set (distinct elements) Map (indexed elements) Multimap (indexed collections) Two collection instances of these classes are equal if and only if both collections belong to the same basic collection class (Seq, Set, Map or Multimap) contain the same elements have the same element order, if the collections are of type Seq Two Map/Multimap elements, resp. entries, (key1, value1) and (key2, value2) are equal, if the keys are equal and the values are equal.
HashMultimap<K,V>	filter(BiPredicate<? super K, ? super V> predicate)	Returns a new Multimap consisting of all elements which satisfy the given predicate.
HashMultimap<K,V>	filter(Predicate<? super Tuple2<K,V>> predicate)	Returns a new traversable consisting of all elements which satisfy the given predicate.
HashMultimap<K,V>	filterKeys(Predicate<? super K> predicate)	Returns a new Multimap consisting of all elements with keys which satisfy the given predicate.
HashMultimap<K,V>	filterValues(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(BiFunction<? super K, ? super V, ? extends Iterable<Tuple2<K2,V2>>> mapper)	FlatMaps this Multimap to a new Multimap with different component type.
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, HashMultimap<K,V>>	groupBy(Function<? super Tuple2<K,V>, ? extends C> classifier)	Groups this elements by classifying the elements.
Iterator<HashMultimap<K,V>>	grouped(int size)	Groups this Traversable into fixed size blocks.
int	hashCode()	Returns the hash code of this collection.
Tuple2<K,V>	head()	Returns the first element of a non-empty Traversable.
HashMultimap<K,V>	init()	Dual of Traversable.tail(), returning all elements except the last.
Option<HashMultimap<K,V>>	initOption()	Dual of Traversable.tailOption(), returning all elements except the last as Option.
boolean	isAsync()	Checks if this Value is asynchronously (short: async) computed.
boolean	isEmpty()	Checks if this Traversable is empty.
boolean	isLazy()	Checks if this Value is lazily evaluated.
Iterator<Tuple2<K,V>>	iterator()	An iterator by means of head() and tail().
Set<K>	keySet()	Returns the keys contained in this multimap.
Tuple2<K,V>	last()	Dual of Traversable.head(), returning the last element.
<K2,V2> Multimap<K2,V2>	map(BiFunction<? super K, ? super V, Tuple2<K2,V2>> mapper)	Maps the entries of this Multimap to form a new Multimap.
<V2> Multimap<K,V2>	mapValues(Function<? super V, ? extends V2> valueMapper)	Maps the values of this Multimap while preserving the corresponding keys.
HashMultimap<K,V>	merge(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> HashMultimap<K,V>	merge(Multimap<K2,V2> that, 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> HashMultimap<K,V>	narrow(HashMultimap<? extends K, ? extends V> map)	Narrows a widened HashMultimap<? extends K, ? extends V> to HashMultimap<K, V> by performing a type safe-cast.
HashMultimap<K,V>	orElse(Iterable<? extends Tuple2<K,V>> other)	Returns this Multimap if it is nonempty, otherwise Multimap created from iterable, using existing multimap properties.
HashMultimap<K,V>	orElse(Supplier<? extends Iterable<? extends Tuple2<K,V>>> supplier)	Returns this Multimap if it is nonempty, otherwise Multimap created from result of evaluating supplier, using existing multimap properties.
Tuple2<HashMultimap<K,V>, HashMultimap<K,V>>	partition(Predicate<? super Tuple2<K,V>> predicate)	Creates a partition of this Traversable by splitting this elements in two in distinct traversables according to a predicate.
HashMultimap<K,V>	peek(Consumer<? super Tuple2<K,V>> action)	Performs the given action on the first element if this is an eager implementation.
HashMultimap<K,V>	put(Tuple2<? extends K, ? extends V> entry)	Convenience method for put(entry._1, entry._2).
HashMultimap<K,V>	put(K key, V value)	Associates the specified value with the specified key in this multimap.
HashMultimap<K,V>	reject(BiPredicate<? super K, ? super V> predicate)	Returns a new Multimap consisting of all elements which do not satisfy the given predicate.
HashMultimap<K,V>	reject(Predicate<? super Tuple2<K,V>> predicate)	Returns a new traversable consisting of all elements which do not satisfy the given predicate.
HashMultimap<K,V>	rejectKeys(Predicate<? super K> predicate)	Returns a new Multimap consisting of all elements with keys which do not satisfy the given predicate.
HashMultimap<K,V>	rejectValues(Predicate<? super V> predicate)	Returns a new Multimap consisting of all elements with values which do not satisfy the given predicate.
HashMultimap<K,V>	remove(K key)	Removes the mapping for a key from this multimap if it is present.
HashMultimap<K,V>	remove(K key, V value)	Removes the key-value pair from this multimap if it is present.
HashMultimap<K,V>	removeAll(Iterable<? extends K> keys)	Removes the mapping for a key from this multimap if it is present.
HashMultimap<K,V>	removeAll(BiPredicate<? super K, ? super V> predicate)	Deprecated.
HashMultimap<K,V>	removeKeys(Predicate<? super K> predicate)	Deprecated.
HashMultimap<K,V>	removeValues(Predicate<? super V> predicate)	Deprecated.
HashMultimap<K,V>	replace(Tuple2<K,V> currentElement, Tuple2<K,V> newElement)	Replaces the first occurrence (if exists) of the given currentElement with newElement.
HashMultimap<K,V>	replace(K key, V oldValue, V newValue)	Replaces the entry with the specified key and oldValue.
HashMultimap<K,V>	replaceAll(Tuple2<K,V> currentElement, Tuple2<K,V> newElement)	Replaces all occurrences of the given currentElement with newElement.
HashMultimap<K,V>	replaceAll(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.
HashMultimap<K,V>	replaceValue(K key, V value)	Replaces the entry for the specified key only if it is currently mapped to some value.
HashMultimap<K,V>	retainAll(Iterable<? extends Tuple2<K,V>> elements)	Keeps all occurrences of the given elements from this.
HashMultimap<K,V>	scan(Tuple2<K,V> zero, BiFunction<? super Tuple2<K,V>, ? super Tuple2<K,V>, ? extends Tuple2<K,V>> operation)	Computes a prefix scan of the elements of the collection.
int	size()	Computes the number of elements of this Traversable.
Iterator<HashMultimap<K,V>>	slideBy(Function<? super Tuple2<K,V>, ?> classifier)	Slides a non-overlapping window of a variable size over this Traversable.
Iterator<HashMultimap<K,V>>	sliding(int size)	Slides a window of a specific size and step size 1 over this Traversable by calling Traversable.sliding(int, int).
Iterator<HashMultimap<K,V>>	sliding(int size, int step)	Slides a window of a specific size and step size over this Traversable.
Tuple2<HashMultimap<K,V>, HashMultimap<K,V>>	span(Predicate<? super Tuple2<K,V>> 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.
String	stringPrefix()	Returns the name of this Value type, which is used by toString().
HashMultimap<K,V>	tail()	Drops the first element of a non-empty Traversable.
Option<HashMultimap<K,V>>	tailOption()	Drops the first element of a non-empty Traversable and returns an Option.
HashMultimap<K,V>	take(int n)	Takes the first n elements of this or all elements, if this length < n.
HashMultimap<K,V>	takeRight(int n)	Takes the last n elements of this or all elements, if this length < n.
HashMultimap<K,V>	takeUntil(Predicate<? super Tuple2<K,V>> predicate)	Takes elements until the predicate holds for the current element.
HashMultimap<K,V>	takeWhile(Predicate<? super Tuple2<K,V>> predicate)	Takes elements while the predicate holds for the current element.
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).
protected <JM extends Map<K, Collection<V>>> JM	toJavaMap(JM javaMap)
String	toString()	Clarifies that values have a proper toString() method implemented.
Traversable<V>	values()
static <V> HashMultimap.Builder<V>	withSeq()
static <V> HashMultimap.Builder<V>	withSet()
static <V extends Comparable<?>> HashMultimap.Builder<V>	withSortedSet()
static <V> HashMultimap.Builder<V>	withSortedSet(Comparator<? super V> comparator)

Methods inherited from class Object

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

Methods inherited from interface Foldable

fold, reduce, reduceOption

Methods inherited from interface Function1

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

Methods inherited from interface Multimap

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

Methods inherited from interface PartialFunction

lift

Methods inherited from interface 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 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

back

protected final Map<K, Traversable<V>> back

emptyContainer

protected final io.vavr.collection.AbstractMultimap.SerializableSupplier<Traversable<?>> emptyContainer

Method Details

withSeq

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

withSet

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

withSortedSet

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

withSortedSet

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

narrow

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

Narrows a widened HashMultimap<? extends K, ? extends V> to HashMultimap<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 Map.

Returns:

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

emptyMapSupplier

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

emptyInstance

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

createFromMap

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

asMap

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

Description copied from interface: Multimap

Converts this Multimap to a Map

Specified by:

asMap in interface Multimap<K,V>

Returns:

Map<K, Traversable<V>>

bimap

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

Description copied from interface: Multimap

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

Specified by:

bimap in interface Multimap<K,V>

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

containsKey

public boolean containsKey(K key)

Description copied from interface: Multimap

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

Specified by:

containsKey in interface Multimap<K,V>

Parameters:

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

Returns:

true if this multimap contains a mapping for the specified key

getContainerType

public Multimap.ContainerType getContainerType()

Description copied from interface: Multimap

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

Specified by:

getContainerType in interface Multimap<K,V>

Returns:

an enum value representing the container type

flatMap

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

Description copied from interface: Multimap

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

Specified by:

flatMap in interface Multimap<K,V>

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.

get

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

Description copied from interface: Multimap

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

Specified by:

get in interface Multimap<K,V>

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

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

Description copied from interface: Multimap

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

Specified by:

getOrElse in interface Multimap<K,V>

Parameters:

key - the key

defaultValue - a default value

Returns:

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

keySet

public Set<K> keySet()

Description copied from interface: Multimap

Returns the keys contained in this multimap.

Specified by:

keySet in interface Multimap<K,V>

Returns:

Set of the keys contained in this multimap.

map

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

Description copied from interface: Multimap

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

Specified by:

map in interface Multimap<K,V>

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

mapValues

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

Description copied from interface: Multimap

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

Specified by:

mapValues in interface Multimap<K,V>

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

put

public HashMultimap<K,V> put(K key,
 V value)

Description copied from interface: Multimap

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.

Specified by:

put in interface Multimap<K,V>

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

public HashMultimap<K,V> put(Tuple2<? extends K, ? extends V> entry)

Description copied from interface: Multimap

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

Specified by:

put in interface Multimap<K,V>

Parameters:

entry - A Tuple2 containing the key and value

Returns:

A new Multimap containing these elements and that entry.

remove

public HashMultimap<K,V> remove(K key)

Description copied from interface: Multimap

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

Specified by:

remove in interface Multimap<K,V>

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

public HashMultimap<K,V> remove(K key,
 V value)

Description copied from interface: Multimap

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

Specified by:

remove in interface Multimap<K,V>

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

public HashMultimap<K,V> removeAll(Iterable<? extends K> keys)

Description copied from interface: Multimap

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

Specified by:

removeAll in interface Multimap<K,V>

Parameters:

keys - keys are to be removed from the multimap

Returns:

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

size

public int size()

Description copied from interface: Traversable

Computes the number of elements of this Traversable.

Same as Traversable.length().

Specified by:

size in interface Multimap<K,V>

Specified by:

size in interface Traversable<K>

Returns:

the number of elements

values

public Traversable<V> values()

Specified by:

values in interface Multimap<K,V>

distinct

public HashMultimap<K,V> distinct()

Description copied from interface: Traversable

Returns a new version of this which contains no duplicates. Elements are compared using equals.

Specified by:

distinct in interface Multimap<K,V>

Specified by:

distinct in interface Traversable<K>

Returns:

a new Traversable containing this elements without duplicates

distinctBy

public HashMultimap<K,V> distinctBy(Comparator<? super Tuple2<K,V>> comparator)

Description copied from interface: Traversable

Returns a new version of this which contains no duplicates. Elements are compared using the given comparator.

Specified by:

distinctBy in interface Multimap<K,V>

Specified by:

distinctBy in interface Traversable<K>

Parameters:

comparator - A comparator

Returns:

a new Traversable containing this elements without duplicates

distinctBy

public <U> HashMultimap<K,V> distinctBy(Function<? super Tuple2<K,V>, ? extends U> keyExtractor)

Description copied from interface: Traversable

Returns a new version of this which contains no duplicates. Elements mapped to keys which are compared using equals.

The elements of the result are determined in the order of their occurrence - first match wins.

Specified by:

distinctBy in interface Multimap<K,V>

Specified by:

distinctBy in interface Traversable<K>

Type Parameters:

U - key type

Parameters:

keyExtractor - A key extractor

Returns:

a new Traversable containing this elements without duplicates

drop

public HashMultimap<K,V> drop(int n)

Description copied from interface: Traversable

Drops the first n elements of this or all elements, if this length < n.

Specified by:

drop in interface Multimap<K,V>

Specified by:

drop in interface Traversable<K>

Parameters:

n - The number of elements to drop.

Returns:

a new instance consisting of all elements of this except the first n ones, or else the empty instance, if this has less than n elements.

dropRight

public HashMultimap<K,V> dropRight(int n)

Description copied from interface: Traversable

Drops the last n elements of this or all elements, if this length < n.

Specified by:

dropRight in interface Multimap<K,V>

Specified by:

dropRight in interface Traversable<K>

Parameters:

n - The number of elements to drop.

Returns:

a new instance consisting of all elements of this except the last n ones, or else the empty instance, if this has less than n elements.

dropUntil

public HashMultimap<K,V> dropUntil(Predicate<? super Tuple2<K,V>> predicate)

Description copied from interface: Traversable

Drops elements until the predicate holds for the current element.

Specified by:

dropUntil in interface Multimap<K,V>

Specified by:

dropUntil in interface Traversable<K>

Parameters:

predicate - A condition tested subsequently for this elements.

Returns:

a new instance consisting of all elements starting from the first one which does satisfy the given predicate.

dropWhile

public HashMultimap<K,V> dropWhile(Predicate<? super Tuple2<K,V>> predicate)

Description copied from interface: Traversable

Drops elements while the predicate holds for the current element.

Note: This is essentially the same as dropUntil(predicate.negate()). It is intended to be used with method references, which cannot be negated directly.

Specified by:

dropWhile in interface Multimap<K,V>

Specified by:

dropWhile in interface Traversable<K>

Parameters:

predicate - A condition tested subsequently for this elements.

Returns:

a new instance consisting of all elements starting from the first one which does not satisfy the given predicate.

filter

public HashMultimap<K,V> filter(Predicate<? super Tuple2<K,V>> predicate)

Description copied from interface: Traversable

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

Specified by:

filter in interface Multimap<K,V>

Specified by:

filter in interface Traversable<K>

Parameters:

predicate - A predicate

Returns:

a new traversable

reject

public HashMultimap<K,V> reject(Predicate<? super Tuple2<K,V>> predicate)

Description copied from interface: Traversable

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

The default implementation is equivalent to

filter(predicate.negate()

Specified by:

reject in interface Multimap<K,V>

Specified by:

reject in interface Traversable<K>

Parameters:

predicate - A predicate

Returns:

a new traversable

filter

public HashMultimap<K,V> filter(BiPredicate<? super K, ? super V> predicate)

Description copied from interface: Multimap

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

Specified by:

filter in interface Multimap<K,V>

Parameters:

predicate - the predicate used to test elements

Returns:

a new Multimap

reject

public HashMultimap<K,V> reject(BiPredicate<? super K, ? super V> predicate)

Description copied from interface: Multimap

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

Specified by:

reject in interface Multimap<K,V>

Parameters:

predicate - the predicate used to test elements

Returns:

a new Multimap

filterKeys

public HashMultimap<K,V> filterKeys(Predicate<? super K> predicate)

Description copied from interface: Multimap

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

Specified by:

filterKeys in interface Multimap<K,V>

Parameters:

predicate - the predicate used to test keys of elements

Returns:

a new Multimap

rejectKeys

public HashMultimap<K,V> rejectKeys(Predicate<? super K> predicate)

Description copied from interface: Multimap

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

Specified by:

rejectKeys in interface Multimap<K,V>

Parameters:

predicate - the predicate used to test keys of elements

Returns:

a new Multimap

filterValues

public HashMultimap<K,V> filterValues(Predicate<? super V> predicate)

Description copied from interface: Multimap

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

Specified by:

filterValues in interface Multimap<K,V>

Parameters:

predicate - the predicate used to test values of elements

Returns:

a new Multimap

rejectValues

public HashMultimap<K,V> rejectValues(Predicate<? super V> predicate)

Description copied from interface: Multimap

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

Specified by:

rejectValues in interface Multimap<K,V>

Parameters:

predicate - the predicate used to test values of elements

Returns:

a new Multimap

removeAll

@Deprecated
public HashMultimap<K,V> removeAll(BiPredicate<? super K, ? super V> predicate)

Deprecated.

Description copied from interface: Multimap

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

Specified by:

removeAll in interface Multimap<K,V>

Parameters:

predicate - the predicate used to test elements

Returns:

a new Multimap

removeKeys

@Deprecated
public HashMultimap<K,V> removeKeys(Predicate<? super K> predicate)

Deprecated.

Description copied from interface: Multimap

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

Specified by:

removeKeys in interface Multimap<K,V>

Parameters:

predicate - the predicate used to test keys of elements

Returns:

a new Multimap

removeValues

@Deprecated
public HashMultimap<K,V> removeValues(Predicate<? super V> predicate)

Deprecated.

Description copied from interface: Multimap

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

Specified by:

removeValues in interface Multimap<K,V>

Parameters:

predicate - the predicate used to test values of elements

Returns:

a new Multimap

groupBy

public <C> Map<C, HashMultimap<K,V>> groupBy(Function<? super Tuple2<K,V>, ? extends C> classifier)

Description copied from interface: Traversable

Groups this elements by classifying the elements.

Specified by:

groupBy in interface Multimap<K,V>

Specified by:

groupBy in interface Traversable<K>

Type Parameters:

C - classified class type

Parameters:

classifier - A function which classifies elements into classes

Returns:

A Map containing the grouped elements

See Also:

• Traversable.arrangeBy(Function)

grouped

public Iterator<HashMultimap<K,V>> grouped(int size)

Description copied from interface: Traversable

Groups this Traversable into fixed size blocks.

Let length be the length of this Iterable. Then grouped is defined as follows:

• If this.isEmpty(), the resulting Iterator is empty.
• If size <= length, the resulting Iterator will contain length / size blocks of size size and maybe a non-empty block of size length % size, if there are remaining elements.
• If size > length, the resulting Iterator will contain one 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]]

Please note that grouped(int) is a special case of Traversable.sliding(int, int), i.e. grouped(size) is the same as sliding(size, size).

Specified by:

grouped in interface Multimap<K,V>

Specified by:

grouped in interface Traversable<K>

Parameters:

size - a positive block size

Returns:

A new Iterator of grouped blocks of the given size

init

public HashMultimap<K,V> init()

Description copied from interface: Traversable

Dual of Traversable.tail(), returning all elements except the last.

Specified by:

init in interface Multimap<K,V>

Specified by:

init in interface Traversable<K>

Returns:

a new instance containing all elements except the last.

head

public Tuple2<K,V> head()

Description copied from interface: Traversable

Returns the first element of a non-empty Traversable.

Specified by:

head in interface Traversable<K>

Returns:

The first element of this Traversable.

initOption

public Option<HashMultimap<K,V>> initOption()

Description copied from interface: Traversable

Dual of Traversable.tailOption(), returning all elements except the last as Option.

Specified by:

initOption in interface Multimap<K,V>

Specified by:

initOption in interface Traversable<K>

Returns:

Some(traversable) or None if this is empty.

isAsync

public boolean isAsync()

Description copied from interface: Value

Checks if this Value is asynchronously (short: async) computed.

Methods of a Value instance that operate on the underlying value may block the current thread until the value is present and the computation can be performed.

Specified by:

isAsync in interface Value<K>

Returns:

true if this Value is async (like Future), false otherwise.

isEmpty

public boolean isEmpty()

Description copied from interface: Traversable

Checks if this Traversable is empty.

Specified by:

isEmpty in interface Traversable<K>

Specified by:

isEmpty in interface Value<K>

Returns:

true, if this Traversable contains no elements, false otherwise.

isLazy

public boolean isLazy()

Description copied from interface: Value

Checks if this Value is lazily evaluated.

Specified by:

isLazy in interface Value<K>

Returns:

true if this Value is lazy (like Lazy and Stream), false otherwise.

iterator

public Iterator<Tuple2<K,V>> iterator()

Description copied from interface: Traversable

An iterator by means of head() and tail(). Subclasses may want to override this method.

Specified by:

iterator in interface Iterable<K>

Specified by:

iterator in interface Multimap<K,V>

Specified by:

iterator in interface Traversable<K>

Specified by:

iterator in interface Value<K>

Returns:

A new Iterator of this Traversable elements.

last

public Tuple2<K,V> last()

Description copied from interface: Traversable

Dual of Traversable.head(), returning the last element.

Specified by:

last in interface Traversable<K>

Returns:

the last element.

merge

public HashMultimap<K,V> merge(Multimap<? extends K, ? extends V> that)

Description copied from interface: Multimap

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.

Specified by:

merge in interface Multimap<K,V>

Parameters:

that - the other multimap

Returns:

A merged multimap

merge

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

Description copied from interface: Multimap

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.

Specified by:

merge in interface Multimap<K,V>

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

orElse

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

Returns this Multimap if it is nonempty, otherwise Multimap created from iterable, using existing multimap properties.

Specified by:

orElse in interface Multimap<K,V>

Specified by:

orElse in interface Traversable<K>

Parameters:

other - An alternative Traversable

Returns:

this Multimap if it is nonempty, otherwise Multimap created from iterable, using existing multimap properties.

orElse

public HashMultimap<K,V> orElse(Supplier<? extends Iterable<? extends Tuple2<K,V>>> supplier)

Returns this Multimap if it is nonempty, otherwise Multimap created from result of evaluating supplier, using existing multimap properties.

Specified by:

orElse in interface Multimap<K,V>

Specified by:

orElse in interface Traversable<K>

Parameters:

supplier - An alternative Traversable

Returns:

this Multimap if it is nonempty, otherwise Multimap created from result of evaluating supplier, using existing multimap properties.

partition

public Tuple2<HashMultimap<K,V>, HashMultimap<K,V>> partition(Predicate<? super Tuple2<K,V>> predicate)

Description copied from interface: Traversable

Creates a partition of this Traversable by splitting this elements in two in distinct traversables according to a predicate.

Specified by:

partition in interface Multimap<K,V>

Specified by:

partition in interface Traversable<K>

Parameters:

predicate - A predicate which classifies an element if it is in the first or the second traversable.

Returns:

A disjoint union of two traversables. The first Traversable contains all elements that satisfy the given predicate, the second Traversable contains all elements that don't. The original order of elements is preserved.

peek

public HashMultimap<K,V> peek(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 Multimap<K,V>

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

public HashMultimap<K,V> replace(Tuple2<K,V> currentElement,
 Tuple2<K,V> newElement)

Description copied from interface: Traversable

Replaces the first occurrence (if exists) of the given currentElement with newElement.

Specified by:

replace in interface Multimap<K,V>

Specified by:

replace in interface Traversable<K>

Parameters:

currentElement - An element to be substituted.

newElement - A replacement for currentElement.

Returns:

a Traversable containing all elements of this where the first occurrence of currentElement is replaced with newElement.

replaceAll

public HashMultimap<K,V> replaceAll(Tuple2<K,V> currentElement,
 Tuple2<K,V> newElement)

Description copied from interface: Traversable

Replaces all occurrences of the given currentElement with newElement.

Specified by:

replaceAll in interface Multimap<K,V>

Specified by:

replaceAll in interface Traversable<K>

Parameters:

currentElement - An element to be substituted.

newElement - A replacement for currentElement.

Returns:

a Traversable containing all elements of this where all occurrences of currentElement are replaced with newElement.

replaceValue

public HashMultimap<K,V> replaceValue(K key,
 V value)

Description copied from interface: Multimap

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

Specified by:

replaceValue in interface Multimap<K,V>

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

public HashMultimap<K,V> replace(K key,
 V oldValue,
 V newValue)

Description copied from interface: Multimap

Replaces the entry with the specified key and oldValue.

Specified by:

replace in interface Multimap<K,V>

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

public HashMultimap<K,V> replaceAll(BiFunction<? super K, ? super V, ? extends V> function)

Description copied from interface: Multimap

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.

Specified by:

replaceAll in interface Multimap<K,V>

Parameters:

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

Returns:

a new map with the same keySet but transformed values

retainAll

public HashMultimap<K,V> retainAll(Iterable<? extends Tuple2<K,V>> elements)

Description copied from interface: Traversable

Keeps all occurrences of the given elements from this.

Specified by:

retainAll in interface Multimap<K,V>

Specified by:

retainAll in interface Traversable<K>

Parameters:

elements - Elements to be kept.

Returns:

a Traversable containing all occurrences of the given elements.

scan

public HashMultimap<K,V> scan(Tuple2<K,V> zero,
 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 the collection. Note: The neutral element z may be applied more than once.

Specified by:

scan in interface Multimap<K,V>

Specified by:

scan in interface Traversable<K>

Parameters:

zero - neutral element for the operator op

operation - the associative operator for the scan

Returns:

a new traversable collection containing the prefix scan of the elements in this traversable collection

slideBy

public Iterator<HashMultimap<K,V>> slideBy(Function<? super Tuple2<K,V>, ?> classifier)

Description copied from interface: Traversable

Slides a non-overlapping window of a variable size over this Traversable.

Each window contains elements with the same class, as determined by classifier. Two consecutive values in this Traversable will be in the same window only if classifier returns equal values for them. Otherwise, the values will constitute the last element of the previous window and the first element of the next window.

Examples:

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

Specified by:

slideBy in interface Multimap<K,V>

Specified by:

slideBy in interface Traversable<K>

Parameters:

classifier - A function which classifies elements into classes

Returns:

A new Iterator of windows of the grouped elements

sliding

public Iterator<HashMultimap<K,V>> sliding(int size)

Description copied from interface: Traversable

Slides a window of a specific size and step size 1 over this Traversable by calling Traversable.sliding(int, int).

Specified by:

sliding in interface Multimap<K,V>

Specified by:

sliding in interface Traversable<K>

Parameters:

size - a positive window size

Returns:

a new Iterator of windows of a specific size using step size 1

sliding

public Iterator<HashMultimap<K,V>> sliding(int size,
 int step)

Description copied from interface: Traversable

Slides a window of a specific size and step size 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 Multimap<K,V>

Specified by:

sliding in interface Traversable<K>

Parameters:

size - a positive window size

step - a positive step size

Returns:

a new Iterator of windows of a specific size using a specific step size

span

public Tuple2<HashMultimap<K,V>, HashMultimap<K,V>> span(Predicate<? super Tuple2<K,V>> predicate)

Description copied from interface: Traversable

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.

Specified by:

span in interface Multimap<K,V>

Specified by:

span in interface Traversable<K>

Parameters:

predicate - A predicate.

Returns:

a Tuple containing the longest prefix of elements that satisfy p and the remainder.

tail

public HashMultimap<K,V> tail()

Description copied from interface: Traversable

Drops the first element of a non-empty Traversable.

Specified by:

tail in interface Multimap<K,V>

Specified by:

tail in interface Traversable<K>

Returns:

A new instance of Traversable containing all elements except the first.

tailOption

public Option<HashMultimap<K,V>> tailOption()

Description copied from interface: Traversable

Drops the first element of a non-empty Traversable and returns an Option.

Specified by:

tailOption in interface Multimap<K,V>

Specified by:

tailOption in interface Traversable<K>

Returns:

Some(traversable) or None if this is empty.

take

public HashMultimap<K,V> take(int n)

Description copied from interface: Traversable

Takes the first n elements of this or all elements, if this length < n.

The result is equivalent to sublist(0, max(0, min(length(), n))) but does not throw if n < 0 or n > length().

In the case of n < 0 the empty instance is returned, in the case of n > length() this is returned.

Specified by:

take in interface Multimap<K,V>

Specified by:

take in interface Traversable<K>

Parameters:

n - The number of elements to take.

Returns:

A new instance consisting of the first n elements of this or all elements, if this has less than n elements.

takeRight

public HashMultimap<K,V> takeRight(int n)

Description copied from interface: Traversable

Takes the last n elements of this or all elements, if this length < n.

The result is equivalent to sublist(max(0, min(length(), length() - n)), n), i.e. takeRight will not throw if n < 0 or n > length().

In the case of n < 0 the empty instance is returned, in the case of n > length() this is returned.

Specified by:

takeRight in interface Multimap<K,V>

Specified by:

takeRight in interface Traversable<K>

Parameters:

n - The number of elements to take.

Returns:

A new instance consisting of the last n elements of this or all elements, if this has less than n elements.

takeUntil

public HashMultimap<K,V> takeUntil(Predicate<? super Tuple2<K,V>> predicate)

Description copied from interface: Traversable

Takes elements until the predicate holds for the current element.

Note: This is essentially the same as takeWhile(predicate.negate()). It is intended to be used with method references, which cannot be negated directly.

Specified by:

takeUntil in interface Multimap<K,V>

Specified by:

takeUntil in interface Traversable<K>

Parameters:

predicate - A condition tested subsequently for this elements.

Returns:

a new instance consisting of all elements before the first one which does satisfy the given predicate.

takeWhile

public HashMultimap<K,V> takeWhile(Predicate<? super Tuple2<K,V>> predicate)

Description copied from interface: Traversable

Takes elements while the predicate holds for the current element.

Specified by:

takeWhile in interface Multimap<K,V>

Specified by:

takeWhile in interface Traversable<K>

Parameters:

predicate - A condition tested subsequently for the contained elements.

Returns:

a new instance consisting of all elements before the first one which does not satisfy the given predicate.

equals

public boolean equals(Object o)

Description copied from interface: Traversable

In Vavr there are four basic classes of collections:

• Seq (sequential elements)
• Set (distinct elements)
• Map (indexed elements)
• Multimap (indexed collections)

Two collection instances of these classes are equal if and only if both collections

• belong to the same basic collection class (Seq, Set, Map or Multimap)
• contain the same elements
• have the same element order, if the collections are of type Seq

Two Map/Multimap elements, resp. entries, (key1, value1) and (key2, value2) are equal, if the keys are equal and the values are equal.

Notes:

• No collection instance equals null, e.g. Queue(1) not equals null.
• Nulls are allowed and handled as expected, e.g. List(null, 1) equals Stream(null, 1) and HashMap((null, 1)) equals LinkedHashMap((null, 1)).
• The element order is taken into account for Seq only. E.g. List(null, 1) not equals Stream(1, null) and HashMap((null, 1), ("a", null)) equals LinkedHashMap(("a", null), (null, 1)). The reason is, that we do not know which implementations we compare when having two instances of type Map, Multimap or Set (see Liskov Substitution Principle).
• Other collection classes are equal if their types are equal and their elements are equal (in iteration order).
• Iterator equality is defined to be object reference equality.

Specified by:

equals in interface Traversable<K>

Specified by:

equals in interface Value<K>

Overrides:

equals in class Object

Parameters:

o - an object, may be null

Returns:

true, if this collection equals the given object according to the rules described above, false otherwise.

hashCode

public int hashCode()

Description copied from interface: Traversable

Returns the hash code of this collection.
We distinguish between two types of hashes, those for collections with predictable iteration order (like Seq) and those with arbitrary iteration order (like Set, Map and Multimap).
In all cases the hash of an empty collection is defined to be 1.
Collections with predictable iteration order are hashed as follows:

int hash = 1;
for (T t : this) { hash = hash * 31 + Objects.hashCode(t); }

Collections with arbitrary iteration order are hashed in a way such that the hash of a fixed number of elements is independent of their iteration order.

int hash = 1;
for (T t : this) { hash += Objects.hashCode(t); }

Please note that the particular hashing algorithms may change in a future version of Vavr.
Generally, hash codes of collections aren't cached in Vavr (opposed to the size/length). Storing hash codes in order to reduce the time complexity would increase the memory footprint. Persistent collections are built upon tree structures, it allows us to implement efficient memory sharing. A drawback of tree structures is that they make it necessary to store collection attributes at each tree node (read: element).
The computation of the hash code is linear in time, i.e. O(n). If the hash code of a collection is re-calculated often, e.g. when using a List as HashMap key, we might want to cache the hash code. This can be achieved by simply using a wrapper class, which is not included in Vavr but could be implemented like this:

public final class Hashed<K> {

    private final K key;
    private final Lazy<Integer> hashCode;

    public Hashed(K key) {
        this.key = key;
        this.hashCode = Lazy.of(() -> Objects.hashCode(key));
    }

    public K key() {
        return key;
    }

    &#64;Override
    public boolean equals(Object o) {
        if (o == key) {
            return true;
        } else if (key != null && o instanceof Hashed) {
            final Hashed that = (Hashed) o;
            return key.equals(that.key);
        } else {
            return false;
        }
    }

    &#64;Override
    public int hashCode() {
        return hashCode.get();
    }

    &#64;Override
    public String toString() {
        return "Hashed(" + (key == null ? "null" : key.toString()) + ")";
    }
}

Specified by:

hashCode in interface Traversable<K>

Specified by:

hashCode in interface Value<K>

Overrides:

hashCode in class Object

Returns:

The hash code of this collection

stringPrefix

public String stringPrefix()

Description copied from interface: Value

Returns the name of this Value type, which is used by toString().

Specified by:

stringPrefix in interface Value<K>

Returns:

This type name.

toString

public String toString()

Description copied from interface: Value

Clarifies that values have a proper toString() method implemented.

See Object.toString().

Specified by:

toString in interface Value<K>

Overrides:

toString in class Object

Returns:

A String representation of this object

toJavaMap

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

Description copied from interface: Multimap

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

Specified by:

toJavaMap in interface Multimap<K,V>

Returns:

a new java.util.Map instance

toJavaMap

protected <JM extends Map<K, Collection<V>>> JM toJavaMap(JM javaMap)