Interface Map<K,V>

Type Parameters:

K - Key type

V - Value type

All Superinterfaces:

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

All Known Subinterfaces:

SortedMap<K,V>

All Known Implementing Classes:

HashMap, LinkedHashMap, TreeMap

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

An immutable Map interface.

Basic operations:

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

Conversion:

• toJavaMap()

Filtering:

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

Iteration:

• forEach(BiConsumer)
• iterator(BiFunction)
• keysIterator()
• valuesIterator()

Transformation:

• bimap(Function, Function)
• flatMap(BiFunction)
• lift()
• map(BiFunction)
• mapKeys(Function)
• mapKeys(Function, BiFunction)
• mapValues(Function)
• transform(Function)
• unzip(BiFunction)
• unzip3(BiFunction)
• withDefault(Function)
• withDefaultValue(Object)

Field Summary

Fields

Modifier and Type	Field	Description
static final long	serialVersionUID

Method Summary

Modifier and Type	Method	Description
default V	apply(K key)	Deprecated.
default PartialFunction<K,V>	asPartialFunction()	Turns this Map into a PartialFunction which is defined at a specific index, if this Map contains the given key.
<K2,V2> Map<K2,V2>	bimap(Function<? super K, ? extends K2> keyMapper, Function<? super V, ? extends V2> valueMapper)	Maps this Map to a new Map with different component type by applying a function to its elements.
default <R> Seq<R>	collect(PartialFunction<? super Tuple2<K,V>, ? extends R> partialFunction)	Collects all elements that are in the domain of the given partialFunction by mapping the elements to type R.
Tuple2<V, ? extends Map<K,V>>	computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction)	If the specified key is not already associated with a value, attempts to compute its value using the given mapping function and enters it into this map.
Tuple2<Option<V>, ? extends Map<K,V>>	computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction)	If the value for the specified key is present, attempts to compute a new mapping given the key and its current mapped value.
default boolean	contains(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 map contains a mapping for the specified key.
default boolean	containsValue(V value)	Returns true if this map maps one or more keys to the specified value.
Map<K,V>	distinct()	Returns a new version of this which contains no duplicates.
Map<K,V>	distinctBy(Comparator<? super Tuple2<K,V>> comparator)	Returns a new version of this which contains no duplicates.
<U> Map<K,V>	distinctBy(Function<? super Tuple2<K,V>, ? extends U> keyExtractor)	Returns a new version of this which contains no duplicates.
Map<K,V>	drop(int n)	Drops the first n elements of this or all elements, if this length < n.
Map<K,V>	dropRight(int n)	Drops the last n elements of this or all elements, if this length < n.
Map<K,V>	dropUntil(Predicate<? super Tuple2<K,V>> predicate)	Drops elements until the predicate holds for the current element.
Map<K,V>	dropWhile(Predicate<? super Tuple2<K,V>> predicate)	Drops elements while the predicate holds for the current element.
static <K,V> Tuple2<K,V>	entry(K key, V value)	Convenience factory method to create a key/value pair.
Map<K,V>	filter(BiPredicate<? super K, ? super V> predicate)	Returns a new Map consisting of all elements which satisfy the given predicate.
Map<K,V>	filter(Predicate<? super Tuple2<K,V>> predicate)	Returns a new traversable consisting of all elements which satisfy the given predicate.
Map<K,V>	filterKeys(Predicate<? super K> predicate)	Returns a new Map consisting of all elements with keys which satisfy the given predicate.
Map<K,V>	filterValues(Predicate<? super V> predicate)	Returns a new Map consisting of all elements with values which satisfy the given predicate.
<K2,V2> Map<K2,V2>	flatMap(BiFunction<? super K, ? super V, ? extends Iterable<Tuple2<K2,V2>>> mapper)	FlatMaps this Map to a new Map with different component type.
default <U> Seq<U>	flatMap(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, BiFunction<? super Tuple2<K,V>, ? super U, ? extends U> f)	Folds this elements from the right, starting with zero and successively calling combine.
default void	forEach(BiConsumer<K,V> action)	Performs an action on key, value pair.
Option<V>	get(K key)	Returns the Some of value to which the specified key is mapped, or None if this map contains no mapping for the key.
V	getOrElse(K key, 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 Map<K,V>>	groupBy(Function<? super Tuple2<K,V>, ? extends C> classifier)	Groups this elements by classifying the elements.
Iterator<? extends Map<K,V>>	grouped(int size)	Groups this Traversable into fixed size blocks.
default boolean	hasDefiniteSize()	Checks if this Traversable is known to have a finite size.
Map<K,V>	init()	Dual of Traversable.tail(), returning all elements except the last.
Option<? extends Map<K,V>>	initOption()	Dual of Traversable.tailOption(), returning all elements except the last as Option.
default boolean	isDefinedAt(K key)	Deprecated.
default boolean	isDistinct()	Checks if this Traversable may consist of distinct elements only.
default boolean	isTraversableAgain()	Checks if this Traversable can be repeatedly traversed.
Iterator<Tuple2<K,V>>	iterator()	An iterator by means of head() and tail().
default <U> Iterator<U>	iterator(BiFunction<K, V, ? extends U> mapper)	Iterates this Map sequentially, mapping the (key, value) pairs to elements.
Set<K>	keySet()	Returns the keys contained in this map.
default Iterator<K>	keysIterator()	Returns the keys contained in this map as an iterator.
default int	length()	Computes the number of elements of this Traversable.
default Function1<K, Option<V>>	lift()	Turns this map into a plain function returning an Option result.
<K2,V2> Map<K2,V2>	map(BiFunction<? super K, ? super V, Tuple2<K2,V2>> mapper)	Maps the entries of this Map to form a new Map.
default <U> Seq<U>	map(Function<? super Tuple2<K,V>, ? extends U> mapper)	Maps the Map entries to a sequence of values.
<K2> Map<K2,V>	mapKeys(Function<? super K, ? extends K2> keyMapper)	Maps the keys of this Map while preserving the corresponding values.
<K2> Map<K2,V>	mapKeys(Function<? super K, ? extends K2> keyMapper, BiFunction<? super V, ? super V, ? extends V> valueMerge)	Maps the keys of this Map while preserving the corresponding values and applying a value merge function on collisions.
<V2> Map<K,V2>	mapValues(Function<? super V, ? extends V2> valueMapper)	Maps the values of this Map while preserving the corresponding keys.
Map<K,V>	merge(Map<? extends K, ? extends V> that)	Creates a new map which by merging the entries of this map and that map.
<U extends V> Map<K,V>	merge(Map<? extends K, U> that, BiFunction<? super V, ? super U, ? extends V> collisionResolution)	Creates a new map which by merging the entries of this map and that map.
static <K,V> Map<K,V>	narrow(Map<? extends K, ? extends V> map)	Narrows a widened Map<? extends K, ? extends V> to Map<K, V> by performing a type-safe cast.
Map<K,V>	orElse(Iterable<? extends Tuple2<K,V>> other)	Returns this Traversable if it is nonempty, otherwise return the alternative.
Map<K,V>	orElse(Supplier<? extends Iterable<? extends Tuple2<K,V>>> supplier)	Returns this Traversable if it is nonempty, otherwise return the result of evaluating supplier.
Tuple2<? extends Map<K,V>, ? extends Map<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.
Map<K,V>	peek(Consumer<? super Tuple2<K,V>> action)	Performs the given action on the first element if this is an eager implementation.
Map<K,V>	put(Tuple2<? extends K, ? extends V> entry)	Convenience method for put(entry._1, entry._2).
<U extends V> Map<K,V>	put(Tuple2<? extends K, U> entry, BiFunction<? super V, ? super U, ? extends V> merge)	Convenience method for put(entry._1, entry._2, merge).
<U extends V> Map<K,V>	put(K key, U value, BiFunction<? super V, ? super U, ? extends V> merge)	Associates the specified value with the specified key in this map.
Map<K,V>	put(K key, V value)	Associates the specified value with the specified key in this map.
Map<K,V>	reject(BiPredicate<? super K, ? super V> predicate)	Returns a new Map consisting of all elements which do not satisfy the given predicate.
Map<K,V>	reject(Predicate<? super Tuple2<K,V>> predicate)	Returns a new traversable consisting of all elements which do not satisfy the given predicate.
Map<K,V>	rejectKeys(Predicate<? super K> predicate)	Returns a new Map consisting of all elements with keys which do not satisfy the given predicate.
Map<K,V>	rejectValues(Predicate<? super V> predicate)	Returns a new Map consisting of all elements with values which do not satisfy the given predicate.
Map<K,V>	remove(K key)	Removes the mapping for a key from this map if it is present.
Map<K,V>	removeAll(Iterable<? extends K> keys)	Removes the mapping for a key from this map if it is present.
Map<K,V>	removeAll(BiPredicate<? super K, ? super V> predicate)	Deprecated. Please use reject(BiPredicate)
Map<K,V>	removeKeys(Predicate<? super K> predicate)	Deprecated. Please use rejectKeys(Predicate)
Map<K,V>	removeValues(Predicate<? super V> predicate)	Deprecated. Please use rejectValues(Predicate)
Map<K,V>	replace(Tuple2<K,V> currentElement, Tuple2<K,V> newElement)	Replaces the first occurrence (if exists) of the given currentElement with newElement.
Map<K,V>	replace(K key, V oldValue, V newValue)	Replaces the entry for the specified key only if currently mapped to the specified value.
Map<K,V>	replaceAll(Tuple2<K,V> currentElement, Tuple2<K,V> newElement)	Replaces all occurrences of the given currentElement with newElement.
Map<K,V>	replaceAll(BiFunction<? super K, ? super V, ? extends V> function)	Replaces each entry's value with the result of invoking the given function on that entry until all entries have been processed or the function throws an exception.
Map<K,V>	replaceValue(K key, V value)	Replaces the entry for the specified key only if it is currently mapped to some value.
Map<K,V>	retainAll(Iterable<? extends Tuple2<K,V>> elements)	Keeps all occurrences of the given elements from this.
Map<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.
default <U> Seq<U>	scanLeft(U zero, BiFunction<? super U, ? super Tuple2<K,V>, ? extends U> operation)	Produces a collection containing cumulative results of applying the operator going left to right.
default <U> Seq<U>	scanRight(U zero, BiFunction<? super Tuple2<K,V>, ? super U, ? extends U> operation)	Produces a collection containing cumulative results of applying the operator going right to left.
int	size()	Computes the number of elements of this Traversable.
Iterator<? extends Map<K,V>>	slideBy(Function<? super Tuple2<K,V>, ?> classifier)	Slides a non-overlapping window of a variable size over this Traversable.
Iterator<? extends Map<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<? extends Map<K,V>>	sliding(int size, int step)	Slides a window of a specific size and step size over this Traversable.
Tuple2<? extends Map<K,V>, ? extends Map<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.
Map<K,V>	tail()	Drops the first element of a non-empty Traversable.
Option<? extends Map<K,V>>	tailOption()	Drops the first element of a non-empty Traversable and returns an Option.
Map<K,V>	take(int n)	Takes the first n elements of this or all elements, if this length < n.
Map<K,V>	takeRight(int n)	Takes the last n elements of this or all elements, if this length < n.
Map<K,V>	takeUntil(Predicate<? super Tuple2<K,V>> predicate)	Takes elements until the predicate holds for the current element.
Map<K,V>	takeWhile(Predicate<? super Tuple2<K,V>> predicate)	Takes elements while the predicate holds for the current element.
Map<K,V>	toJavaMap()	Converts this Vavr Map to a java.util.Map while preserving characteristics like insertion order (LinkedHashMap) and sort order (SortedMap).
default <U> U	transform(Function<? super Map<K,V>, ? extends U> f)	Transforms this Map.
default Tuple2<Seq<K>,Seq<V>>	unzip()
default <T1,T2> Tuple2<Seq<T1>,Seq<T2>>	unzip(BiFunction<? super K, ? super V, Tuple2<? extends T1, ? extends T2>> unzipper)
default <T1,T2> Tuple2<Seq<T1>,Seq<T2>>	unzip(Function<? super Tuple2<K,V>, Tuple2<? extends T1, ? extends T2>> unzipper)	Unzips this elements by mapping this elements to pairs which are subsequently split into two distinct sets.
default <T1,T2,T3> Tuple3<Seq<T1>,Seq<T2>,Seq<T3>>	unzip3(BiFunction<? super K, ? super V, Tuple3<? extends T1, ? extends T2, ? extends T3>> unzipper)
default <T1,T2,T3> Tuple3<Seq<T1>,Seq<T2>,Seq<T3>>	unzip3(Function<? super Tuple2<K,V>, Tuple3<? extends T1, ? extends T2, ? extends T3>> unzipper)	Unzips this elements by mapping this elements to triples which are subsequently split into three distinct sets.
Seq<V>	values()	Returns a new Seq that contains the values of this Map.
default Iterator<V>	valuesIterator()	Returns the values in this map.
default Function1<K,V>	withDefault(Function<? super K, ? extends V> defaultFunction)	Deprecated. Will be removed
default Function1<K,V>	withDefaultValue(V defaultValue)	Deprecated. Will be removed
default <U> Seq<Tuple2<Tuple2<K,V>, U>>	zip(Iterable<? extends U> that)	Returns a traversable formed from this traversable and another Iterable collection by combining corresponding elements in pairs.
default <U> Seq<Tuple2<Tuple2<K,V>, U>>	zipAll(Iterable<? extends U> that, Tuple2<K,V> thisElem, U thatElem)	Returns a traversable formed from this traversable and another Iterable by combining corresponding elements in pairs.
default <U,R> Seq<R>	zipWith(Iterable<? extends U> that, BiFunction<? super Tuple2<K,V>, ? super U, ? extends R> mapper)	Returns a traversable formed from this traversable and another Iterable collection by mapping elements.
default Seq<Tuple2<Tuple2<K,V>, Integer>>	zipWithIndex()	Zips this traversable with its indices.
default <U> Seq<U>	zipWithIndex(BiFunction<? super Tuple2<K,V>, ? super Integer, ? extends U> mapper)	Zips this traversable with its indices by applying mapper provided.

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 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

See Also:

• Constant Field Values

Method Details

narrow

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

Narrows a widened Map<? extends K, ? extends V> to Map<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 map instance as narrowed type Map<K, V>.

entry

static <K,V> Tuple2<K,V> entry(K key,
 V value)

Convenience factory method to create a key/value pair.

If imported statically, this method allows to create a Map with arbitrary entries in a readable and type-safe way, e.g.:

HashMap.ofEntries(
    entry(k1, v1),
    entry(k2, v2),
    entry(k3, v3)
);

Type Parameters:

K - Key type

V - Value type

Parameters:

key - the entry's key

value - the entry's value

Returns:

a key/value pair

apply

@Deprecated
default 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 argument

Returns:

the result of function application

asPartialFunction

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

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

Returns:

a new PartialFunction

Throws:

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

IndexOutOfBoundsException

collect

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

Description copied from interface: Traversable

Collects all elements that are in the domain of the given partialFunction by mapping the elements to type R.

More specifically, for each of this elements in iteration order first it is checked

partialFunction.isDefinedAt(element)

If the elements makes it through that filter, the mapped instance is added to the result collection

R newElement = partialFunction.apply(element)

Note:If this Traversable is ordered (i.e. extends Ordered, the caller of collect has to ensure that the elements are comparable (i.e. extend Comparable).

Specified by:

collect in interface Traversable<K>

Type Parameters:

R - The new element type

Parameters:

partialFunction - A function that is not necessarily defined of all elements of this traversable.

Returns:

A new Traversable instance containing elements of type R

bimap

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

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

Type Parameters:

K2 - key's component type of the map result

V2 - value's component type of the map 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 Map

Throws:

NullPointerException - if keyMapper or valueMapper is null

contains

default boolean contains(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.

computeIfAbsent

Tuple2<V, ? extends Map<K,V>> computeIfAbsent(K key,
 Function<? super K, ? extends V> mappingFunction)

If the specified key is not already associated with a value, attempts to compute its value using the given mapping function and enters it into this map.

Parameters:

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

mappingFunction - mapping function

Returns:

the Tuple2 of current or modified map and existing or computed value associated with the specified key

computeIfPresent

Tuple2<Option<V>, ? extends Map<K,V>> computeIfPresent(K key,
 BiFunction<? super K, ? super V, ? extends V> remappingFunction)

If the value for the specified key is present, attempts to compute a new mapping given the key and its current mapped value.

Parameters:

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

remappingFunction - remapping function

Returns:

the Tuple2 of current or modified map and the Some of the value associated with the specified key, or None if none

containsKey

boolean containsKey(K key)

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

Parameters:

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

Returns:

true if this map contains a mapping for the specified key

containsValue

default boolean containsValue(V value)

Returns true if this map 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 map is to be tested

Returns:

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

filter

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

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

Parameters:

predicate - the predicate used to test elements

Returns:

a new Map

Throws:

NullPointerException - if predicate is null

reject

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

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

Parameters:

predicate - the predicate used to test elements

Returns:

a new Map

Throws:

NullPointerException - if predicate is null

filterKeys

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

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

Parameters:

predicate - the predicate used to test keys of elements

Returns:

a new Map

Throws:

NullPointerException - if predicate is null

rejectKeys

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

Returns a new Map 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 Map

Throws:

NullPointerException - if predicate is null

filterValues

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

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

Parameters:

predicate - the predicate used to test values of elements

Returns:

a new Map

Throws:

NullPointerException - if predicate is null

rejectValues

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

Returns a new Map 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 Map

Throws:

NullPointerException - if predicate is null

flatMap

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

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

Type Parameters:

K2 - key's component type of the mapped Map

V2 - value's component type of the mapped Map

Parameters:

mapper - A mapper

Returns:

A new Map.

Throws:

NullPointerException - if mapper is null

flatMap

default <U> Seq<U> flatMap(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 Map

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,
 BiFunction<? super Tuple2<K,V>, ? super U, ? extends U> f)

Description copied from interface: Foldable

Folds this elements from the right, starting with zero and successively calling combine.

Example:

// = "!cba"
List("a", "b", "c").foldRight("!", (x, xs) -> xs + x)
 

Specified by:

foldRight in interface Foldable<K>

Specified by:

foldRight in interface Traversable<K>

Type Parameters:

U - the type of the folded value

Parameters:

zero - A zero element to start with.

f - A function which combines elements.

Returns:

a folded value

forEach

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

Performs an action on key, value pair.

Parameters:

action - A BiConsumer

Throws:

NullPointerException - if action is null

get

Option<V> get(K key)

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

getOrElse

V getOrElse(K key,
 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 default value.

hasDefiniteSize

default boolean hasDefiniteSize()

Description copied from interface: Traversable

Checks if this Traversable is known to have a finite size.

This method should be implemented by classes only, i.e. not by interfaces.

Specified by:

hasDefiniteSize in interface Traversable<K>

Returns:

true, if this Traversable is known to have a finite size, false otherwise.

isTraversableAgain

default boolean isTraversableAgain()

Description copied from interface: Traversable

Checks if this Traversable can be repeatedly traversed.

This method should be implemented by classes only, i.e. not by interfaces.

Specified by:

isTraversableAgain in interface Traversable<K>

Returns:

true, if this Traversable is known to be traversable repeatedly, false otherwise.

iterator

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 Traversable<K>

Specified by:

iterator in interface Value<K>

Returns:

A new Iterator of this Traversable elements.

iterator

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

Iterates this Map 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 map.

Returns:

Set of the keys contained in this map.

keysIterator

default Iterator<K> keysIterator()

Returns the keys contained in this map as an iterator.

Returns:

Iterator of the keys contained in this map.

length

default int length()

Description copied from interface: Traversable

Computes the number of elements of this Traversable.

Same as Traversable.size().

Specified by:

length in interface Traversable<K>

Returns:

the number of elements

lift

default Function1<K, Option<V>> lift()

Turns this map into a plain function returning an Option result.

Specified by:

lift in interface PartialFunction<K,V>

Returns:

a function that takes a key k and returns its value in a Some if found, otherwise a None.

map

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

Maps the Map entries to a sequence of values.

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

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.

map

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

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

Type Parameters:

K2 - key's component type of the map result

V2 - value's component type of the map result

Parameters:

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

Returns:

a new Map

Throws:

NullPointerException - if mapper is null

mapKeys

<K2> Map<K2,V> mapKeys(Function<? super K, ? extends K2> keyMapper)

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

The size of the result map may be smaller if keyMapper maps two or more distinct keys to the same new key. In this case the value at the latest of the original keys is retained. Order of keys is predictable in TreeMap (by comparator) and LinkedHashMap (insertion-order) and not predictable in HashMap.

Type Parameters:

K2 - the new key type

Parameters:

keyMapper - a Function that maps keys of type V to keys of type V2

Returns:

a new Map

Throws:

NullPointerException - if keyMapper is null

mapKeys

<K2> Map<K2,V> mapKeys(Function<? super K, ? extends K2> keyMapper,
 BiFunction<? super V, ? super V, ? extends V> valueMerge)

Maps the keys of this Map while preserving the corresponding values and applying a value merge function on collisions.

The size of the result map may be smaller if keyMapper maps two or more distinct keys to the same new key. In this case the associated values will be combined using valueMerge.

Type Parameters:

K2 - the new key type

Parameters:

keyMapper - a Function that maps keys of type V to keys of type V2

valueMerge - a BiFunction that merges values

Returns:

a new Map

Throws:

NullPointerException - if keyMapper is null

mapValues

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

Maps the values of this Map 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 Map

Throws:

NullPointerException - if valueMapper is null

merge

Map<K,V> merge(Map<? extends K, ? extends V> that)

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

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

Parameters:

that - the other map

Returns:

A merged map

Throws:

NullPointerException - if that map is null

merge

<U extends V> Map<K,V> merge(Map<? extends K, U> that,
 BiFunction<? super V, ? super U, ? extends V> collisionResolution)

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

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

Type Parameters:

U - value type of that Map

Parameters:

that - the other map

collisionResolution - the collision resolution function

Returns:

A merged map

Throws:

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

put

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

Associates the specified value with the specified key in this map. 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 Map containing these elements and that entry.

put

Map<K,V> put(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 Map containing these elements and that entry.

put

<U extends V> Map<K,V> put(K key,
 U value,
 BiFunction<? super V, ? super U, ? extends V> merge)

Associates the specified value with the specified key in this map. If the map previously contained a mapping for the key, the merge function is used to combine the previous value to the value to be inserted, and the result of that call is inserted in the map.

Type Parameters:

U - the value type

Parameters:

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

value - value to be associated with the specified key

merge - function taking the old and new values and merging them.

Returns:

A new Map containing these elements and that entry.

put

<U extends V> Map<K,V> put(Tuple2<? extends K, U> entry,
 BiFunction<? super V, ? super U, ? extends V> merge)

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

Type Parameters:

U - the value type

Parameters:

entry - A Tuple2 containing the key and value

merge - function taking the old and new values and merging them.

Returns:

A new Map containing these elements and that entry.

remove

Map<K,V> remove(K key)

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

Parameters:

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

Returns:

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

removeAll

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

Deprecated.

Please use reject(BiPredicate)

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

Parameters:

predicate - the predicate used to test elements

Returns:

a new Map

Throws:

NullPointerException - if predicate is null

removeAll

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

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

Parameters:

keys - keys are to be removed from the map

Returns:

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

removeKeys

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

Deprecated.

Please use rejectKeys(Predicate)

Returns a new Map 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 Map

Throws:

NullPointerException - if predicate is null

removeValues

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

Deprecated.

Please use rejectValues(Predicate)

Returns a new Map 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 Map

Throws:

NullPointerException - if predicate is null

scanLeft

default <U> Seq<U> scanLeft(U zero,
 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 going left to right. Note: will not terminate for infinite-sized collections. Note: might return different results for different runs, unless the underlying collection type is ordered.

Specified by:

scanLeft in interface Traversable<K>

Type Parameters:

U - the type of the elements in the resulting collection

Parameters:

zero - the initial value

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

Returns:

collection with intermediate results

scanRight

default <U> Seq<U> scanRight(U zero,
 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 going right to left. The head of the collection is the last cumulative result. Note: will not terminate for infinite-sized collections. Note: might return different results for different runs, unless the underlying collection type is ordered.

Specified by:

scanRight in interface Traversable<K>

Type Parameters:

U - the type of the elements in the resulting collection

Parameters:

zero - the initial value

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

Returns:

collection with intermediate results

size

int size()

Description copied from interface: Traversable

Computes the number of elements of this Traversable.

Same as Traversable.length().

Specified by:

size in interface Traversable<K>

Returns:

the number of elements

toJavaMap

Map<K,V> toJavaMap()

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

Returns:

a new java.util.Map instance

transform

default <U> U transform(Function<? super Map<K,V>, ? extends U> f)

Transforms this Map.

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 Tuple2<Seq<K>,Seq<V>> unzip()

unzip

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

unzip

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

Description copied from interface: Traversable

Unzips this elements by mapping this elements to pairs which are subsequently split into two distinct sets.

Specified by:

unzip in interface Traversable<K>

Type Parameters:

T1 - 1st element type of a pair returned by unzipper

T2 - 2nd element type of a pair returned by unzipper

Parameters:

unzipper - a function which converts elements of this to pairs

Returns:

A pair of set containing elements split by unzipper

unzip3

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

unzip3

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

Description copied from interface: Traversable

Unzips this elements by mapping this elements to triples which are subsequently split into three distinct sets.

Specified by:

unzip3 in interface Traversable<K>

Type Parameters:

T1 - 1st element type of a triplet returned by unzipper

T2 - 2nd element type of a triplet returned by unzipper

T3 - 3rd element type of a triplet returned by unzipper

Parameters:

unzipper - a function which converts elements of this to pairs

Returns:

A triplet of set containing elements split by unzipper

values

Seq<V> values()

Returns a new Seq that contains the values of this Map.

// = Seq("a", "b", "c")
HashMap.of(1, "a", 2, "b", 3, "c").values()

Returns:

a new Seq

valuesIterator

default Iterator<V> valuesIterator()

Returns the values in this map.

// = Iterator.of("a", "b", "c")
HashMap.of(1, "a", 2, "b", 3, "c").values()

Returns:

a new Iterator

withDefault

@Deprecated
default Function1<K,V> withDefault(Function<? super K, ? extends V> defaultFunction)

Deprecated.

Will be removed

Turns this map from a partial function into a total function that returns a value computed by defaultFunction for all keys absent from the map.

Parameters:

defaultFunction - function to evaluate for all keys not present in the map

Returns:

a total function from K to T

withDefaultValue

@Deprecated
default Function1<K,V> withDefaultValue(V defaultValue)

Deprecated.

Will be removed

Turns this map from a partial function into a total function that returns defaultValue for all keys absent from the map.

Parameters:

defaultValue - default value to return for all keys not present in the map

Returns:

a total function from K to T

zip

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

Description copied from interface: Traversable

Returns a traversable formed from this traversable and another Iterable collection by combining corresponding elements in pairs. If one of the two iterables is longer than the other, its remaining elements are ignored.

The length of the returned traversable is the minimum of the lengths of this traversable and that iterable.

Specified by:

zip in interface Traversable<K>

Type Parameters:

U - The type of the second half of the returned pairs.

Parameters:

that - The Iterable providing the second half of each result pair.

Returns:

a new traversable containing pairs consisting of corresponding elements of this traversable and that iterable.

zipWith

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

Description copied from interface: Traversable

Returns a traversable formed from this traversable and another Iterable collection by mapping elements. If one of the two iterables is longer than the other, its remaining elements are ignored.

The length of the returned traversable is the minimum of the lengths of this traversable and that iterable.

Specified by:

zipWith in interface Traversable<K>

Type Parameters:

U - The type of the second parameter of the mapper.

R - The type of the mapped elements.

Parameters:

that - The Iterable providing the second parameter of the mapper.

mapper - a mapper.

Returns:

a new traversable containing mapped elements of this traversable and that iterable.

zipAll

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

Description copied from interface: Traversable

Returns a traversable formed from this traversable and another Iterable by combining corresponding elements in pairs. If one of the two collections is shorter than the other, placeholder elements are used to extend the shorter collection to the length of the longer.

The length of the returned traversable is the maximum of the lengths of this traversable and that iterable.

Special case: if this traversable is shorter than that elements, and that elements contains duplicates, the resulting traversable may be shorter than the maximum of the lengths of this and that because a traversable contains an element at most once.

If this Traversable is shorter than that, thisElem values are used to fill the result. If that is shorter than this Traversable, thatElem values are used to fill the result.

Specified by:

zipAll in interface Traversable<K>

Type Parameters:

U - The type of the second half of the returned pairs.

Parameters:

that - The Iterable providing the second half of each result pair.

thisElem - The element to be used to fill up the result if this traversable is shorter than that.

thatElem - The element to be used to fill up the result if that is shorter than this traversable.

Returns:

A new traversable containing pairs consisting of corresponding elements of this traversable and that.

zipWithIndex

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

Description copied from interface: Traversable

Zips this traversable with its indices.

Specified by:

zipWithIndex in interface Traversable<K>

Returns:

A new traversable containing all elements of this traversable paired with their index, starting with 0.

zipWithIndex

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

Description copied from interface: Traversable

Zips this traversable with its indices by applying mapper provided.

Specified by:

zipWithIndex in interface Traversable<K>

Type Parameters:

U - The type of the mapped elements.

Parameters:

mapper - a mapper.

Returns:

a new traversable containing elements of this traversable, zipped with indices, and mapped with mapper provided.

distinct

Map<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 Traversable<K>

Returns:

a new Traversable containing this elements without duplicates

distinctBy

Map<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 Traversable<K>

Parameters:

comparator - A comparator

Returns:

a new Traversable containing this elements without duplicates

distinctBy

<U> Map<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 Traversable<K>

Type Parameters:

U - key type

Parameters:

keyExtractor - A key extractor

Returns:

a new Traversable containing this elements without duplicates

drop

Map<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 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

Map<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 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

Map<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 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

Map<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 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

Map<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 Traversable<K>

Parameters:

predicate - A predicate

Returns:

a new traversable

reject

Map<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 Traversable<K>

Parameters:

predicate - A predicate

Returns:

a new traversable

groupBy

<C> Map<C, ? extends Map<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 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

Iterator<? extends Map<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 Traversable<K>

Parameters:

size - a positive block size

Returns:

A new Iterator of grouped blocks of the given size

isDefinedAt

@Deprecated
default boolean isDefinedAt(K key)

Deprecated.

Description copied from interface: PartialFunction

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

Specified by:

isDefinedAt in interface PartialFunction<K,V>

Parameters:

key - a potential function argument

Returns:

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

isDistinct

default boolean isDistinct()

Description copied from interface: Traversable

Checks if this Traversable may consist of distinct elements only.

Specified by:

isDistinct in interface Traversable<K>

Returns:

true if this Traversable may consist of distinct elements only, false otherwise.

init

Map<K,V> init()

Description copied from interface: Traversable

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

Specified by:

init in interface Traversable<K>

Returns:

a new instance containing all elements except the last.

initOption

Option<? extends Map<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 Traversable<K>

Returns:

Some(traversable) or None if this is empty.

orElse

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

Description copied from interface: Traversable

Returns this Traversable if it is nonempty, otherwise return the alternative.

Specified by:

orElse in interface Traversable<K>

Parameters:

other - An alternative Traversable

Returns:

this Traversable if it is nonempty, otherwise return the alternative.

orElse

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

Description copied from interface: Traversable

Returns this Traversable if it is nonempty, otherwise return the result of evaluating supplier.

Specified by:

orElse in interface Traversable<K>

Parameters:

supplier - An alternative Traversable supplier

Returns:

this Traversable if it is nonempty, otherwise return the result of evaluating supplier.

partition

Tuple2<? extends Map<K,V>, ? extends Map<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 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

Map<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 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

Map<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 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.

replaceValue

Map<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

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

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

Parameters:

key - the key of the element to be substituted.

oldValue - the expected current value that the key is currently mapped to

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 matched. The old map otherwise.

replaceAll

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

Replaces each entry's value with the result of invoking the given function on that entry 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.

replaceAll

Map<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 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.

retainAll

Map<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 Traversable<K>

Parameters:

elements - Elements to be kept.

Returns:

a Traversable containing all occurrences of the given elements.

scan

Map<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 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

Iterator<? extends Map<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 Traversable<K>

Parameters:

classifier - A function which classifies elements into classes

Returns:

A new Iterator of windows of the grouped elements

sliding

Iterator<? extends Map<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 Traversable<K>

Parameters:

size - a positive window size

Returns:

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

sliding

Iterator<? extends Map<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 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

Tuple2<? extends Map<K,V>, ? extends Map<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 Traversable<K>

Parameters:

predicate - A predicate.

Returns:

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

tail

Map<K,V> tail()

Description copied from interface: Traversable

Drops the first element of a non-empty Traversable.

Specified by:

tail in interface Traversable<K>

Returns:

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

tailOption

Option<? extends Map<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 Traversable<K>

Returns:

Some(traversable) or None if this is empty.

take

Map<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 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

Map<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 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

Map<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 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

Map<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 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.