Interface Map<K,V>
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- Type Parameters:
K- Key typeV- Value type
- All Superinterfaces:
Foldable<Tuple2<K,V>>,java.util.function.Function<K,V>,Function1<K,V>,java.lang.Iterable<Tuple2<K,V>>,PartialFunction<K,V>,java.io.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>, java.io.Serializable
An immutableMapinterface.Represents a collection of key-value pairs with immutable operations. Supports typical map operations such as querying, updating, filtering, transforming, and iterating over entries. Provides convenient methods for converting to standard Java maps and for working with default values.
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Field Summary
Fields Modifier and Type Field Description static longserialVersionUIDThe serial version UID for serialization.
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Method Summary
All Methods Static Methods Instance Methods Abstract Methods Default Methods Deprecated Methods Modifier and Type Method Description default Vapply(K key)Deprecated.default PartialFunction<K,V>asPartialFunction()Turns thisMapinto aPartialFunctionwhich is defined at a specific index, if thisMapcontains the given key.<K2,V2>
Map<K2,V2>bimap(@NonNull java.util.function.Function<? super K,? extends K2> keyMapper, @NonNull java.util.function.Function<? super V,? extends V2> valueMapper)Maps thisMapto a newMapwith different component type by applying a function to its elements.default <R> Seq<R>collect(@NonNull PartialFunction<? super Tuple2<K,V>,? extends R> partialFunction)Applies aPartialFunctionto all elements that are defined for it and collects the results.Tuple2<V,? extends Map<K,V>>computeIfAbsent(K key, @NonNull java.util.function.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, @NonNull java.util.function.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 booleancontains(@NonNull Tuple2<K,V> element)Shortcut forexists(e -> Objects.equals(e, element)), tests if the givenelementis contained.booleancontainsKey(K key)Returnstrueif this map contains a mapping for the specified key.default booleancontainsValue(V value)Returnstrueif this map maps one or more keys to the specified value.Map<K,V>distinct()Returns a newTraversablecontaining the elements of this instance with all duplicates removed.Map<K,V>distinctBy(@NonNull java.util.Comparator<? super Tuple2<K,V>> comparator)Returns a newTraversablecontaining the elements of this instance without duplicates, as determined by the givencomparator.<U> Map<K,V>distinctBy(@NonNull java.util.function.Function<? super Tuple2<K,V>,? extends U> keyExtractor)Returns a newTraversablecontaining the elements of this instance without duplicates, based on keys extracted from elements usingkeyExtractor.Map<K,V>drop(int n)Returns a newTraversablewithout the firstnelements, or an empty instance if this contains fewer thannelements.Map<K,V>dropRight(int n)Returns a newTraversablewithout the lastnelements, or an empty instance if this contains fewer thannelements.Map<K,V>dropUntil(@NonNull java.util.function.Predicate<? super Tuple2<K,V>> predicate)Returns a newTraversablestarting from the first element that satisfies the givenpredicate, dropping all preceding elements.Map<K,V>dropWhile(@NonNull java.util.function.Predicate<? super Tuple2<K,V>> predicate)Returns a newTraversablestarting from the first element that does not satisfy the givenpredicate, dropping all preceding elements.static <K,V>
Tuple2<K,V>entry(K key, V value)Creates a key/value pair for use withMapfactories.Map<K,V>filter(@NonNull java.util.function.BiPredicate<? super K,? super V> predicate)Returns a new Map consisting of all elements which satisfy the given predicate.Map<K,V>filter(@NonNull java.util.function.Predicate<? super Tuple2<K,V>> predicate)Returns a new traversable containing only the elements that satisfy the given predicate.Map<K,V>filterKeys(@NonNull java.util.function.Predicate<? super K> predicate)Returns a new Map consisting of all elements with keys which satisfy the given predicate.Map<K,V>filterValues(@NonNull java.util.function.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(@NonNull java.util.function.BiFunction<? super K,? super V,? extends java.lang.Iterable<Tuple2<K2,V2>>> mapper)FlatMaps thisMapto a newMapwith different component type.default <U> Seq<U>flatMap(@NonNull java.util.function.Function<? super Tuple2<K,V>,? extends java.lang.Iterable<? extends U>> mapper)Flat-maps this entries to a sequence of values.default <U> UfoldRight(U zero, @NonNull java.util.function.BiFunction<? super Tuple2<K,V>,? super U,? extends U> f)Folds the elements of this structure from the right, starting with the givenzerovalue and successively applying thecombinefunction to each element.default voidforEach(@NonNull java.util.function.BiConsumer<K,V> action)Performs an action on key, value pair.Option<V>get(K key)Returns theSomeof value to which the specified key is mapped, orNoneif this map contains no mapping for the key.VgetOrElse(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(@NonNull java.util.function.Function<? super Tuple2<K,V>,? extends C> classifier)Groups elements of thisTraversablebased on a classifier function.Iterator<? extends Map<K,V>>grouped(int size)Splits thisTraversableinto consecutive blocks of the given size.default booleanhasDefiniteSize()Indicates whether thisTraversablehas a known finite size.Map<K,V>init()Returns all elements of this Traversable except the last one.Option<? extends Map<K,V>>initOption()Returns all elements of this Traversable except the last one, wrapped in anOption.default booleanisDefinedAt(K key)Deprecated.default booleanisDistinct()Indicates whether this Traversable may contain only distinct elements.default booleanisTraversableAgain()Checks if this Traversable can be traversed multiple times without side effects.@NonNull Iterator<Tuple2<K,V>>iterator()Returns an iterator over the elements of this Traversable, implemented viaTraversable.head()andTraversable.tail().default <U> Iterator<U>iterator(@NonNull java.util.function.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 intlength()Returns the number of elements in 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(@NonNull java.util.function.BiFunction<? super K,? super V,Tuple2<K2,V2>> mapper)Maps the entries of thisMapto form a newMap.default <U> Seq<U>map(@NonNull java.util.function.Function<? super Tuple2<K,V>,? extends U> mapper)Maps theMapentries to a sequence of values.<K2> Map<K2,V>mapKeys(@NonNull java.util.function.Function<? super K,? extends K2> keyMapper)Maps the keys of thisMapwhile preserving the corresponding values.<K2> Map<K2,V>mapKeys(@NonNull java.util.function.Function<? super K,? extends K2> keyMapper, @NonNull java.util.function.BiFunction<? super V,? super V,? extends V> valueMerge)Maps the keys of thisMapwhile preserving the corresponding values and applying a value merge function on collisions.default <U> Seq<U>mapTo(U value)Maps the underlying value to another fixed value.default Seq<java.lang.Void>mapToVoid()Maps the underlying value to Void<V2> Map<K,V2>mapValues(@NonNull java.util.function.Function<? super V,? extends V2> valueMapper)Maps the values of thisMapwhile preserving the corresponding keys.Map<K,V>merge(@NonNull Map<? extends K,? extends V> that)Creates a new map which by merging the entries ofthismap andthatmap.<U extends V>
Map<K,V>merge(@NonNull Map<? extends K,U> that, @NonNull java.util.function.BiFunction<? super V,? super U,? extends V> collisionResolution)Creates a new map which by merging the entries ofthismap andthatmap.static <K,V>
Map<K,V>narrow(Map<? extends K,? extends V> map)Narrows a widenedMap<? extends K, ? extends V>toMap<K, V>by performing a type-safe cast.Map<K,V>orElse(@NonNull java.util.function.Supplier<? extends java.lang.Iterable<? extends Tuple2<K,V>>> supplier)Returns thisTraversableif it is non-empty; otherwise, returns the result of evaluating the given supplier.Map<K,V>orElse(java.lang.Iterable<? extends Tuple2<K,V>> other)Returns thisTraversableif it is non-empty; otherwise, returns the given alternative.Tuple2<? extends Map<K,V>,? extends Map<K,V>>partition(@NonNull java.util.function.Predicate<? super Tuple2<K,V>> predicate)Splits thisTraversableinto two partitions according to a predicate.Map<K,V>peek(@NonNull java.util.function.Consumer<? super Tuple2<K,V>> action)Performs the givenactionon the first element if this is an eager implementation.Map<K,V>put(@NonNull Tuple2<? extends K,? extends V> entry)Convenience method forput(entry._1, entry._2).<U extends V>
Map<K,V>put(@NonNull Tuple2<? extends K,U> entry, @NonNull java.util.function.BiFunction<? super V,? super U,? extends V> merge)Convenience method forput(entry._1, entry._2, merge).<U extends V>
Map<K,V>put(K key, U value, @NonNull java.util.function.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(@NonNull java.util.function.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(@NonNull java.util.function.Predicate<? super Tuple2<K,V>> predicate)Returns a new traversable containing only the elements that do not satisfy the given predicate.Map<K,V>rejectKeys(@NonNull java.util.function.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(@NonNull java.util.function.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(@NonNull java.lang.Iterable<? extends K> keys)Removes the mapping for a key from this map if it is present.Map<K,V>removeAll(@NonNull java.util.function.BiPredicate<? super K,? super V> predicate)Deprecated.Please usereject(BiPredicate)Map<K,V>removeKeys(@NonNull java.util.function.Predicate<? super K> predicate)Deprecated.Please userejectKeys(Predicate)Map<K,V>removeValues(@NonNull java.util.function.Predicate<? super V> predicate)Deprecated.Please userejectValues(Predicate)Map<K,V>replace(@NonNull Tuple2<K,V> currentElement, @NonNull Tuple2<K,V> newElement)Replaces the first occurrence ofcurrentElementwithnewElement, if it exists.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(@NonNull Tuple2<K,V> currentElement, Tuple2<K,V> newElement)Replaces all occurrences ofcurrentElementwithnewElement.Map<K,V>replaceAll(@NonNull java.util.function.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(@NonNull java.lang.Iterable<? extends Tuple2<K,V>> elements)Retains only the elements from this Traversable that are contained in the givenelements.Map<K,V>scan(@NonNull Tuple2<K,V> zero, @NonNull java.util.function.BiFunction<? super Tuple2<K,V>,? super Tuple2<K,V>,? extends Tuple2<K,V>> operation)Computes a prefix scan of the elements of this Traversable.default <U> Seq<U>scanLeft(U zero, @NonNull java.util.function.BiFunction<? super U,? super Tuple2<K,V>,? extends U> operation)Produces a collection containing cumulative results of applying the operator from left to right.default <U> Seq<U>scanRight(U zero, @NonNull java.util.function.BiFunction<? super Tuple2<K,V>,? super U,? extends U> operation)Produces a collection containing cumulative results of applying the operator from right to left.intsize()Returns the number of elements in this Traversable.Iterator<? extends Map<K,V>>slideBy(@NonNull java.util.function.Function<? super Tuple2<K,V>,?> classifier)Partitions thisTraversableinto consecutive non-overlapping windows according to a classification function.Iterator<? extends Map<K,V>>sliding(int size)Slides a window of a givensizeover thisTraversablewith a step size of 1.Iterator<? extends Map<K,V>>sliding(int size, int step)Slides a window of a specificsizewith a givenstepover thisTraversable.Tuple2<? extends Map<K,V>,? extends Map<K,V>>span(@NonNull java.util.function.Predicate<? super Tuple2<K,V>> predicate)Splits thisTraversableinto a prefix and remainder according to the givenpredicate.Map<K,V>tail()Returns a newTraversablewithout its first element.Option<? extends Map<K,V>>tailOption()Returns a newTraversablewithout its first element as anOption.Map<K,V>take(int n)Returns the firstnelements of thisTraversable, or all elements ifnexceeds the length.Map<K,V>takeRight(int n)Returns the lastnelements of thisTraversable, or all elements ifnexceeds the length.Map<K,V>takeUntil(@NonNull java.util.function.Predicate<? super Tuple2<K,V>> predicate)Takes elements from thisTraversableuntil the given predicate holds for an element.Map<K,V>takeWhile(@NonNull java.util.function.Predicate<? super Tuple2<K,V>> predicate)Takes elements from thisTraversablewhile the given predicate holds.java.util.Map<K,V>toJavaMap()Converts this VavrMapto ajava.util.Mapwhile preserving characteristics like insertion order (LinkedHashMap) and sort order (SortedMap).default <U> Utransform(@NonNull java.util.function.Function<? super Map<K,V>,? extends U> f)Transforms thisMap.default Tuple2<Seq<K>,Seq<V>>unzip()Unzips the entries of thisMapby treating each key-value pair as an element, and splitting them into two separateSeqcollections - one for keys and one for values.default <T1,T2>
Tuple2<Seq<T1>,Seq<T2>>unzip(@NonNull java.util.function.BiFunction<? super K,? super V,Tuple2<? extends T1,? extends T2>> unzipper)Unzips the entries of thisMapby mapping each key-value pair to a tuple.default <T1,T2>
Tuple2<Seq<T1>,Seq<T2>>unzip(@NonNull java.util.function.Function<? super Tuple2<K,V>,Tuple2<? extends T1,? extends T2>> unzipper)Unzips the elements of thisTraversableby mapping each element to a pair and splitting them into two separateTraversablecollections.default <T1,T2,T3>
Tuple3<Seq<T1>,Seq<T2>,Seq<T3>>unzip3(@NonNull java.util.function.BiFunction<? super K,? super V,Tuple3<? extends T1,? extends T2,? extends T3>> unzipper)Unzips the entries of thisMapby mapping each key-value pair to a triple.default <T1,T2,T3>
Tuple3<Seq<T1>,Seq<T2>,Seq<T3>>unzip3(@NonNull java.util.function.Function<? super Tuple2<K,V>,Tuple3<? extends T1,? extends T2,? extends T3>> unzipper)Unzips the elements of thisTraversableby mapping each element to a triple and splitting them into three separateTraversablecollections.Seq<V>values()Returns a newSeqthat contains the values of thisMap.default Iterator<V>valuesIterator()Returns the values in this map.default Function1<K,V>withDefault(@NonNull java.util.function.Function<? super K,? extends V> defaultFunction)Deprecated.Will be removeddefault Function1<K,V>withDefaultValue(V defaultValue)Deprecated.Will be removeddefault <U> Seq<Tuple2<Tuple2<K,V>,U>>zip(@NonNull java.lang.Iterable<? extends U> that)Returns aTraversableformed by pairing elements of thisTraversablewith elements of anotherIterable.default <U> Seq<Tuple2<Tuple2<K,V>,U>>zipAll(@NonNull java.lang.Iterable<? extends U> that, Tuple2<K,V> thisElem, U thatElem)Returns aTraversableformed by pairing elements of thisTraversablewith elements of anotherIterable, filling in placeholder elements when one collection is shorter than the other.default <U,R>
Seq<R>zipWith(@NonNull java.lang.Iterable<? extends U> that, java.util.function.BiFunction<? super Tuple2<K,V>,? super U,? extends R> mapper)Returns aTraversableby combining elements of thisTraversablewith elements of anotherIterableusing a mapping function.default Seq<Tuple2<Tuple2<K,V>,java.lang.Integer>>zipWithIndex()Zips thisTraversablewith its indices, starting at 0.default <U> Seq<U>zipWithIndex(@NonNull java.util.function.BiFunction<? super Tuple2<K,V>,? super java.lang.Integer,? extends U> mapper)Zips thisTraversablewith its indices and maps the resulting pairs using the provided mapper.-
Methods inherited from interface io.vavr.collection.Foldable
fold, reduce, reduceOption
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Methods inherited from interface io.vavr.Function1
andThen, arity, compose, compose1, curried, isMemoized, memoized, partial, reversed, tupled
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Methods inherited from interface io.vavr.collection.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
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Methods inherited from interface io.vavr.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
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Field Detail
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serialVersionUID
static final long serialVersionUID
The serial version UID for serialization.- See Also:
- Constant Field Values
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Method Detail
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narrow
static <K,V> Map<K,V> narrow(Map<? extends K,? extends V> map)
Narrows a widenedMap<? extends K, ? extends V>toMap<K, V>by performing a type-safe cast. This is eligible because immutable/read-only collections are covariant.- Type Parameters:
K- Key typeV- Value type- Parameters:
map- AMap.- Returns:
- the given
mapinstance as narrowed typeMap<K, V>.
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entry
static <K,V> Tuple2<K,V> entry(K key, V value)
Creates a key/value pair for use withMapfactories.When imported statically, this method enables constructing maps in a readable and type-safe way, for example:
HashMap.ofEntries( entry(k1, v1), entry(k2, v2), entry(k3, v3) );- Type Parameters:
K- key typeV- value type- Parameters:
key- the entry's keyvalue- the entry's value- Returns:
- a key/value pair
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apply
@Deprecated default V apply(K key)
Deprecated.Description copied from interface:PartialFunctionApplies this function to the given argument and returns the result.
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asPartialFunction
default PartialFunction<K,V> asPartialFunction() throws java.util.NoSuchElementException
Turns thisMapinto aPartialFunctionwhich is defined at a specific index, if thisMapcontains the given key. When applied to a defined key, the partial function will return the value of thisMapthat is associated with the key.- Returns:
- a new
PartialFunction - Throws:
java.util.NoSuchElementException- when a non-existing key is applied to the partial function
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collect
default <R> Seq<R> collect(@NonNull PartialFunction<? super Tuple2<K,V>,? extends R> partialFunction)
Description copied from interface:TraversableApplies aPartialFunctionto all elements that are defined for it and collects the results.For each element in iteration order, the function is first tested:
IfpartialFunction.isDefinedAt(element)true, the element is mapped to typeR:R newElement = partialFunction.apply(element)Note: If this
Traversableis ordered (i.e., extendsOrdered), the caller must ensure that the resulting elements are comparable (i.e., implementComparable).- Specified by:
collectin interfaceTraversable<K>- Type Parameters:
R- the type of elements in the resultingTraversable- Parameters:
partialFunction- a function that may not be defined for all elements of this traversable- Returns:
- a new
Traversablecontaining the results of applying the partial function
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bimap
<K2,V2> Map<K2,V2> bimap(@NonNull java.util.function.Function<? super K,? extends K2> keyMapper, @NonNull java.util.function.Function<? super V,? extends V2> valueMapper)
Maps thisMapto a newMapwith different component type by applying a function to its elements.- Type Parameters:
K2- key's component type of the map resultV2- value's component type of the map result- Parameters:
keyMapper- aFunctionthat maps the keys of typeKto keys of typeK2valueMapper- aFunctionthat the values of typeVto values of typeV2- Returns:
- a new
Map - Throws:
java.lang.NullPointerException- ifkeyMapperorvalueMapperis null
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contains
default boolean contains(@NonNull Tuple2<K,V> element)
Description copied from interface:ValueShortcut forexists(e -> Objects.equals(e, element)), tests if the givenelementis contained.
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computeIfAbsent
Tuple2<V,? extends Map<K,V>> computeIfAbsent(K key, @NonNull java.util.function.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 testedmappingFunction- mapping function- Returns:
- the
Tuple2of current or modified map and existing or computed value associated with the specified key
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computeIfPresent
Tuple2<Option<V>,? extends Map<K,V>> computeIfPresent(K key, @NonNull java.util.function.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 testedremappingFunction- remapping function- Returns:
- the
Tuple2of current or modified map and theSomeof the value associated with the specified key, orNoneif none
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containsKey
boolean containsKey(K key)
Returnstrueif this map contains a mapping for the specified key.- Parameters:
key- key whose presence in this map is to be tested- Returns:
trueif this map contains a mapping for the specified key
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containsValue
default boolean containsValue(V value)
Returnstrueif 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:
trueif this map maps one or more keys to the specified value
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filter
Map<K,V> filter(@NonNull java.util.function.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:
java.lang.NullPointerException- ifpredicateis null
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reject
Map<K,V> reject(@NonNull java.util.function.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:
java.lang.NullPointerException- ifpredicateis null
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filterKeys
Map<K,V> filterKeys(@NonNull java.util.function.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:
java.lang.NullPointerException- ifpredicateis null
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rejectKeys
Map<K,V> rejectKeys(@NonNull java.util.function.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:
java.lang.NullPointerException- ifpredicateis null
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filterValues
Map<K,V> filterValues(@NonNull java.util.function.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:
java.lang.NullPointerException- ifpredicateis null
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rejectValues
Map<K,V> rejectValues(@NonNull java.util.function.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:
java.lang.NullPointerException- ifpredicateis null
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flatMap
<K2,V2> Map<K2,V2> flatMap(@NonNull java.util.function.BiFunction<? super K,? super V,? extends java.lang.Iterable<Tuple2<K2,V2>>> mapper)
FlatMaps thisMapto a newMapwith different component type.- Type Parameters:
K2- key's component type of the mappedMapV2- value's component type of the mappedMap- Parameters:
mapper- A mapper- Returns:
- A new
Map. - Throws:
java.lang.NullPointerException- ifmapperis null
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flatMap
default <U> Seq<U> flatMap(@NonNull java.util.function.Function<? super Tuple2<K,V>,? extends java.lang.Iterable<? extends U>> mapper)
Flat-maps this entries to a sequence of values.Please use
flatMap(BiFunction)if the result should be aMap- Specified by:
flatMapin interfaceTraversable<K>- Type Parameters:
U- Component type- Parameters:
mapper- A mapper- Returns:
- A sequence of flat-mapped values.
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foldRight
default <U> U foldRight(U zero, @NonNull java.util.function.BiFunction<? super Tuple2<K,V>,? super U,? extends U> f)Description copied from interface:FoldableFolds the elements of this structure from the right, starting with the givenzerovalue and successively applying thecombinefunction to each element.Folding from the right means that elements are combined starting from the last element and associating each step with the accumulated result so far.
Example:
// Result: "!cba" List.of("a", "b", "c").foldRight("!", (x, acc) -> acc + x);- Specified by:
foldRightin interfaceFoldable<K>- Specified by:
foldRightin interfaceTraversable<K>- Type Parameters:
U- the type of the accumulated result- Parameters:
zero- the initial value to start folding withf- a function that combines the next element and the accumulated value- Returns:
- the folded result
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forEach
default void forEach(@NonNull java.util.function.BiConsumer<K,V> action)
Performs an action on key, value pair.- Parameters:
action- ABiConsumer- Throws:
java.lang.NullPointerException- ifactionis null
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get
Option<V> get(K key)
Returns theSomeof value to which the specified key is mapped, orNoneif this map contains no mapping for the key.- Parameters:
key- the key whose associated value is to be returned- Returns:
- the
Someof value to which the specified key is mapped, orNoneif this map contains no mapping for the key
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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 keydefaultValue- a default value- Returns:
- the value associated with key if it exists, otherwise the default value.
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hasDefiniteSize
default boolean hasDefiniteSize()
Description copied from interface:TraversableIndicates whether thisTraversablehas a known finite size.This should typically be implemented by concrete classes, not interfaces.
- Specified by:
hasDefiniteSizein interfaceTraversable<K>- Returns:
trueif the number of elements is finite and known,falseotherwise.
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isTraversableAgain
default boolean isTraversableAgain()
Description copied from interface:TraversableChecks if this Traversable can be traversed multiple times without side effects.Implementations should provide the correct behavior; this is not meant for interfaces alone.
- Specified by:
isTraversableAgainin interfaceTraversable<K>- Returns:
trueif this Traversable is guaranteed to be repeatably traversable,falseotherwise
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iterator
@NonNull Iterator<Tuple2<K,V>> iterator()
Description copied from interface:TraversableReturns an iterator over the elements of this Traversable, implemented viaTraversable.head()andTraversable.tail(). Subclasses may override for a more efficient implementation.
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iterator
default <U> Iterator<U> iterator(@NonNull java.util.function.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.
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keySet
Set<K> keySet()
Returns the keys contained in this map.- Returns:
Setof the keys contained in this map.
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keysIterator
default Iterator<K> keysIterator()
Returns the keys contained in this map as an iterator.- Returns:
Iteratorof the keys contained in this map.
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length
default int length()
Description copied from interface:TraversableReturns the number of elements in this Traversable.Equivalent to
Traversable.size().- Specified by:
lengthin interfaceTraversable<K>- Returns:
- the number of elements
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lift
default Function1<K,Option<V>> lift()
Turns this map into a plain function returning an Option result.- Specified by:
liftin interfacePartialFunction<K,V>- Returns:
- a function that takes a key k and returns its value in a Some if found, otherwise a None.
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map
default <U> Seq<U> map(@NonNull java.util.function.Function<? super Tuple2<K,V>,? extends U> mapper)
Maps theMapentries to a sequence of values.Please use
map(BiFunction)if the result has to be of typeMap.
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mapTo
default <U> Seq<U> mapTo(U value)
Description copied from interface:ValueMaps the underlying value to another fixed value.
-
mapToVoid
default Seq<java.lang.Void> mapToVoid()
Description copied from interface:ValueMaps the underlying value to Void
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map
<K2,V2> Map<K2,V2> map(@NonNull java.util.function.BiFunction<? super K,? super V,Tuple2<K2,V2>> mapper)
Maps the entries of thisMapto form a newMap.- Type Parameters:
K2- key's component type of the map resultV2- value's component type of the map result- Parameters:
mapper- aFunctionthat maps entries of type(K, V)to entries of type(K2, V2)- Returns:
- a new
Map - Throws:
java.lang.NullPointerException- ifmapperis null
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mapKeys
<K2> Map<K2,V> mapKeys(@NonNull java.util.function.Function<? super K,? extends K2> keyMapper)
Maps the keys of thisMapwhile preserving the corresponding values.The size of the result map may be smaller if
keyMappermaps two or more distinct keys to the same new key. In this case the value at thelatestof the original keys is retained. Order of keys is predictable inTreeMap(by comparator) andLinkedHashMap(insertion-order) and not predictable inHashMap.- Type Parameters:
K2- the new key type- Parameters:
keyMapper- aFunctionthat maps keys of typeVto keys of typeV2- Returns:
- a new
Map - Throws:
java.lang.NullPointerException- ifkeyMapperis null
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mapKeys
<K2> Map<K2,V> mapKeys(@NonNull java.util.function.Function<? super K,? extends K2> keyMapper, @NonNull java.util.function.BiFunction<? super V,? super V,? extends V> valueMerge)
Maps the keys of thisMapwhile preserving the corresponding values and applying a value merge function on collisions.The size of the result map may be smaller if
keyMappermaps two or more distinct keys to the same new key. In this case the associated values will be combined usingvalueMerge.- Type Parameters:
K2- the new key type- Parameters:
keyMapper- aFunctionthat maps keys of typeVto keys of typeV2valueMerge- aBiFunctionthat merges values- Returns:
- a new
Map - Throws:
java.lang.NullPointerException- ifkeyMapperis null
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mapValues
<V2> Map<K,V2> mapValues(@NonNull java.util.function.Function<? super V,? extends V2> valueMapper)
Maps the values of thisMapwhile preserving the corresponding keys.- Type Parameters:
V2- the new value type- Parameters:
valueMapper- aFunctionthat maps values of typeVto values of typeV2- Returns:
- a new
Map - Throws:
java.lang.NullPointerException- ifvalueMapperis null
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merge
Map<K,V> merge(@NonNull Map<? extends K,? extends V> that)
Creates a new map which by merging the entries ofthismap andthatmap.If collisions occur, the value of
thismap is taken.- Parameters:
that- the other map- Returns:
- A merged map
- Throws:
java.lang.NullPointerException- if that map is null
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merge
<U extends V> Map<K,V> merge(@NonNull Map<? extends K,U> that, @NonNull java.util.function.BiFunction<? super V,? super U,? extends V> collisionResolution)
Creates a new map which by merging the entries ofthismap andthatmap.Uses the specified collision resolution function if two keys are the same. The collision resolution function will always take the first argument from
thismap and the second fromthatmap.- Type Parameters:
U- value type of that Map- Parameters:
that- the other mapcollisionResolution- the collision resolution function- Returns:
- A merged map
- Throws:
java.lang.NullPointerException- if that map or the given collision resolution function is null
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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 associatedvalue- value to be associated with the specified key- Returns:
- A new Map containing these elements and that entry.
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put
Map<K,V> put(@NonNull Tuple2<? extends K,? extends V> entry)
Convenience method forput(entry._1, entry._2).- Parameters:
entry- A Tuple2 containing the key and value- Returns:
- A new Map containing these elements and that entry.
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put
<U extends V> Map<K,V> put(K key, U value, @NonNull java.util.function.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 associatedvalue- value to be associated with the specified keymerge- function taking the old and new values and merging them.- Returns:
- A new Map containing these elements and that entry.
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put
<U extends V> Map<K,V> put(@NonNull Tuple2<? extends K,U> entry, @NonNull java.util.function.BiFunction<? super V,? super U,? extends V> merge)
Convenience method forput(entry._1, entry._2, merge).- Type Parameters:
U- the value type- Parameters:
entry- A Tuple2 containing the key and valuemerge- function taking the old and new values and merging them.- Returns:
- A new Map containing these elements and that entry.
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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.
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removeAll
@Deprecated Map<K,V> removeAll(@NonNull java.util.function.BiPredicate<? super K,? super V> predicate)
Deprecated.Please usereject(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:
java.lang.NullPointerException- ifpredicateis null
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removeAll
Map<K,V> removeAll(@NonNull java.lang.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(@NonNull java.util.function.Predicate<? super K> predicate)
Deprecated.Please userejectKeys(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:
java.lang.NullPointerException- ifpredicateis null
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removeValues
@Deprecated Map<K,V> removeValues(@NonNull java.util.function.Predicate<? super V> predicate)
Deprecated.Please userejectValues(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:
java.lang.NullPointerException- ifpredicateis null
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scanLeft
default <U> Seq<U> scanLeft(U zero, @NonNull java.util.function.BiFunction<? super U,? super Tuple2<K,V>,? extends U> operation)
Description copied from interface:TraversableProduces a collection containing cumulative results of applying the operator from left to right.Will not terminate for infinite collections. The results may vary across runs unless the collection is ordered.
- Specified by:
scanLeftin interfaceTraversable<K>- Type Parameters:
U- the type of the resulting elements- Parameters:
zero- the initial valueoperation- a binary operator applied to the intermediate result and each element- Returns:
- a new Traversable containing the cumulative results
-
scanRight
default <U> Seq<U> scanRight(U zero, @NonNull java.util.function.BiFunction<? super Tuple2<K,V>,? super U,? extends U> operation)
Description copied from interface:TraversableProduces a collection containing cumulative results of applying the operator from right to left.The head of the resulting collection is the last cumulative result. Will not terminate for infinite collections. Results may vary across runs unless the collection is ordered.
- Specified by:
scanRightin interfaceTraversable<K>- Type Parameters:
U- the type of the resulting elements- Parameters:
zero- the initial valueoperation- a binary operator applied to each element and the intermediate result- Returns:
- a new Traversable containing the cumulative results
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size
int size()
Description copied from interface:TraversableReturns the number of elements in this Traversable.Alias for
Traversable.length().- Specified by:
sizein interfaceTraversable<K>- Returns:
- the number of elements
-
toJavaMap
java.util.Map<K,V> toJavaMap()
Converts this VavrMapto ajava.util.Mapwhile preserving characteristics like insertion order (LinkedHashMap) and sort order (SortedMap).- Returns:
- a new
java.util.Mapinstance
-
transform
default <U> U transform(@NonNull java.util.function.Function<? super Map<K,V>,? extends U> f)
Transforms thisMap.- Type Parameters:
U- Type of transformation result- Parameters:
f- A transformation- Returns:
- An instance of type
U - Throws:
java.lang.NullPointerException- iffis null
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unzip
default Tuple2<Seq<K>,Seq<V>> unzip()
Unzips the entries of thisMapby treating each key-value pair as an element, and splitting them into two separateSeqcollections - one for keys and one for values.- Returns:
- a
Tuple2containing twoSeqcollections: first with all keys, second with all values
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unzip
default <T1,T2> Tuple2<Seq<T1>,Seq<T2>> unzip(@NonNull java.util.function.BiFunction<? super K,? super V,Tuple2<? extends T1,? extends T2>> unzipper)
Unzips the entries of thisMapby mapping each key-value pair to a tuple. The unzipper function transforms each entry into aTuple2, and then all first elements are collected into the firstSeqand all second elements into the secondSeq.- Type Parameters:
T1- type of the first element in the resulting pairsT2- type of the second element in the resulting pairs- Parameters:
unzipper- a function that maps key-value pairs of thisMapto tuples- Returns:
- a
Tuple2containing twoSeqcollections with the split elements - Throws:
java.lang.NullPointerException- ifunzipperis null
-
unzip
default <T1,T2> Tuple2<Seq<T1>,Seq<T2>> unzip(@NonNull java.util.function.Function<? super Tuple2<K,V>,Tuple2<? extends T1,? extends T2>> unzipper)
Description copied from interface:TraversableUnzips the elements of thisTraversableby mapping each element to a pair and splitting them into two separateTraversablecollections.- Specified by:
unzipin interfaceTraversable<K>- Type Parameters:
T1- type of the first element in the resulting pairsT2- type of the second element in the resulting pairs- Parameters:
unzipper- a function that maps elements of thisTraversableto pairs- Returns:
- a
Tuple2containing twoTraversablecollections with the split elements
-
unzip3
default <T1,T2,T3> Tuple3<Seq<T1>,Seq<T2>,Seq<T3>> unzip3(@NonNull java.util.function.BiFunction<? super K,? super V,Tuple3<? extends T1,? extends T2,? extends T3>> unzipper)
Unzips the entries of thisMapby mapping each key-value pair to a triple. The unzipper function transforms each entry into aTuple3, and then elements are distributed to respectiveSeqcollections by their position in the tuple: all first elements into the firstSeq, all second elements into the secondSeq, and all third elements into the thirdSeq.- Type Parameters:
T1- type of the first element in the resulting triplesT2- type of the second element in the resulting triplesT3- type of the third element in the resulting triples- Parameters:
unzipper- a function that maps key-value pairs of thisMapto triples- Returns:
- a
Tuple3containing threeSeqcollections with the split elements - Throws:
java.lang.NullPointerException- ifunzipperis null
-
unzip3
default <T1,T2,T3> Tuple3<Seq<T1>,Seq<T2>,Seq<T3>> unzip3(@NonNull java.util.function.Function<? super Tuple2<K,V>,Tuple3<? extends T1,? extends T2,? extends T3>> unzipper)
Description copied from interface:TraversableUnzips the elements of thisTraversableby mapping each element to a triple and splitting them into three separateTraversablecollections.- Specified by:
unzip3in interfaceTraversable<K>- Type Parameters:
T1- type of the first element in the resulting triplesT2- type of the second element in the resulting triplesT3- type of the third element in the resulting triples- Parameters:
unzipper- a function that maps elements of thisTraversableto triples- Returns:
- a
Tuple3containing threeTraversablecollections with the split elements
-
values
Seq<V> values()
Returns a newSeqthat contains the values of thisMap.// = 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(@NonNull java.util.function.Function<? super K,? extends V> defaultFunction)
Deprecated.Will be removedTurns 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 removedTurns 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(@NonNull java.lang.Iterable<? extends U> that)
Description copied from interface:TraversableReturns aTraversableformed by pairing elements of thisTraversablewith elements of anotherIterable. Pairing stops when either collection runs out of elements; any remaining elements in the longer collection are ignored.The length of the resulting
Traversableis the minimum of the lengths of thisTraversableandthat.- Specified by:
zipin interfaceTraversable<K>- Type Parameters:
U- the type of elements in the second half of each pair- Parameters:
that- anIterableproviding the second element of each pair- Returns:
- a new
Traversablecontaining pairs of corresponding elements
-
zipWith
default <U,R> Seq<R> zipWith(@NonNull java.lang.Iterable<? extends U> that, java.util.function.BiFunction<? super Tuple2<K,V>,? super U,? extends R> mapper)
Description copied from interface:TraversableReturns aTraversableby combining elements of thisTraversablewith elements of anotherIterableusing a mapping function. Pairing stops when either collection runs out of elements.The length of the resulting
Traversableis the minimum of the lengths of thisTraversableandthat.- Specified by:
zipWithin interfaceTraversable<K>- Type Parameters:
U- the type of elements in the second parameter of the mapperR- the type of elements in the resultingTraversable- Parameters:
that- anIterableproviding the second parameter of the mappermapper- a function that combines elements from this andthatinto a new element- Returns:
- a new
Traversablecontaining mapped elements
-
zipAll
default <U> Seq<Tuple2<Tuple2<K,V>,U>> zipAll(@NonNull java.lang.Iterable<? extends U> that, Tuple2<K,V> thisElem, U thatElem)
Description copied from interface:TraversableReturns aTraversableformed by pairing elements of thisTraversablewith elements of anotherIterable, filling in placeholder elements when one collection is shorter than the other.The length of the resulting
Traversableis the maximum of the lengths of thisTraversableandthat.If this
Traversableis shorter thanthat,thisElemis used as a filler. Conversely, ifthatis shorter,thatElemis used.- Specified by:
zipAllin interfaceTraversable<K>- Type Parameters:
U- the type of elements in the second half of each pair- Parameters:
that- anIterableproviding the second element of each pairthisElem- the element used to fill missing values if thisTraversableis shorter thanthatthatElem- the element used to fill missing values ifthatis shorter than thisTraversable- Returns:
- a new
Traversablecontaining pairs of elements, including fillers as needed
-
zipWithIndex
default Seq<Tuple2<Tuple2<K,V>,java.lang.Integer>> zipWithIndex()
Description copied from interface:TraversableZips thisTraversablewith its indices, starting at 0.- Specified by:
zipWithIndexin interfaceTraversable<K>- Returns:
- a new
Traversablecontaining each element paired with its index
-
zipWithIndex
default <U> Seq<U> zipWithIndex(@NonNull java.util.function.BiFunction<? super Tuple2<K,V>,? super java.lang.Integer,? extends U> mapper)
Description copied from interface:TraversableZips thisTraversablewith its indices and maps the resulting pairs using the provided mapper.- Specified by:
zipWithIndexin interfaceTraversable<K>- Type Parameters:
U- the type of elements in the resultingTraversable- Parameters:
mapper- a function mapping an element and its index to a new element- Returns:
- a new
Traversablecontaining the mapped elements
-
distinct
Map<K,V> distinct()
Description copied from interface:TraversableReturns a newTraversablecontaining the elements of this instance with all duplicates removed. Element equality is determined usingequals.- Specified by:
distinctin interfaceTraversable<K>- Returns:
- a new
Traversablewithout duplicate elements
-
distinctBy
Map<K,V> distinctBy(@NonNull java.util.Comparator<? super Tuple2<K,V>> comparator)
Description copied from interface:TraversableReturns a newTraversablecontaining the elements of this instance without duplicates, as determined by the givencomparator.- Specified by:
distinctByin interfaceTraversable<K>- Parameters:
comparator- a comparator used to determine equality of elements- Returns:
- a new
Traversablewith duplicates removed
-
distinctBy
<U> Map<K,V> distinctBy(@NonNull java.util.function.Function<? super Tuple2<K,V>,? extends U> keyExtractor)
Description copied from interface:TraversableReturns a newTraversablecontaining the elements of this instance without duplicates, based on keys extracted from elements usingkeyExtractor.The first occurrence of each key is retained in the resulting sequence.
- Specified by:
distinctByin interfaceTraversable<K>- Type Parameters:
U- the type of key- Parameters:
keyExtractor- a function to extract keys for determining uniqueness- Returns:
- a new
Traversablewith duplicates removed based on keys
-
drop
Map<K,V> drop(int n)
Description copied from interface:TraversableReturns a newTraversablewithout the firstnelements, or an empty instance if this contains fewer thannelements.- Specified by:
dropin interfaceTraversable<K>- Parameters:
n- the number of elements to drop- Returns:
- a new instance excluding the first
nelements
-
dropRight
Map<K,V> dropRight(int n)
Description copied from interface:TraversableReturns a newTraversablewithout the lastnelements, or an empty instance if this contains fewer thannelements.- Specified by:
dropRightin interfaceTraversable<K>- Parameters:
n- the number of elements to drop from the end- Returns:
- a new instance excluding the last
nelements
-
dropUntil
Map<K,V> dropUntil(@NonNull java.util.function.Predicate<? super Tuple2<K,V>> predicate)
Description copied from interface:TraversableReturns a newTraversablestarting from the first element that satisfies the givenpredicate, dropping all preceding elements.- Specified by:
dropUntilin interfaceTraversable<K>- Parameters:
predicate- a condition tested on each element- Returns:
- a new instance starting from the first element matching the predicate
-
dropWhile
Map<K,V> dropWhile(@NonNull java.util.function.Predicate<? super Tuple2<K,V>> predicate)
Description copied from interface:TraversableReturns a newTraversablestarting from the first element that does not satisfy the givenpredicate, dropping all preceding elements.This is equivalent to
dropUntil(predicate.negate()), which is useful for method references that cannot be negated directly.- Specified by:
dropWhilein interfaceTraversable<K>- Parameters:
predicate- a condition tested on each element- Returns:
- a new instance starting from the first element not matching the predicate
-
filter
Map<K,V> filter(@NonNull java.util.function.Predicate<? super Tuple2<K,V>> predicate)
Description copied from interface:TraversableReturns a new traversable containing only the elements that satisfy the given predicate.- Specified by:
filterin interfaceTraversable<K>- Parameters:
predicate- the condition to test elements- Returns:
- a traversable with elements matching the predicate
-
reject
Map<K,V> reject(@NonNull java.util.function.Predicate<? super Tuple2<K,V>> predicate)
Description copied from interface:TraversableReturns a new traversable containing only the elements that do not satisfy the given predicate.This is equivalent to
filter(predicate.negate()).- Specified by:
rejectin interfaceTraversable<K>- Parameters:
predicate- the condition to test elements- Returns:
- a traversable with elements not matching the predicate
-
groupBy
<C> Map<C,? extends Map<K,V>> groupBy(@NonNull java.util.function.Function<? super Tuple2<K,V>,? extends C> classifier)
Description copied from interface:TraversableGroups elements of thisTraversablebased on a classifier function.- Specified by:
groupByin interfaceTraversable<K>- Type Parameters:
C- The type of the group keys- Parameters:
classifier- A function that assigns each element to a group- Returns:
- A map where each key corresponds to a group of elements
- See Also:
Traversable.arrangeBy(Function)
-
grouped
Iterator<? extends Map<K,V>> grouped(int size)
Description copied from interface:TraversableSplits thisTraversableinto consecutive blocks of the given size.Let
lengthbe the number of elements in thisTraversable:- If empty, the resulting
Iteratoris empty. - If
size <= length, the resultingIteratorcontainslength / sizeblocks of sizesizeand possibly a final smaller block of sizelength % size. - If
size > length, the resultingIteratorcontains a single block of sizelength.
Examples:
[].grouped(1) = [] [].grouped(0) throws [].grouped(-1) throws [1,2,3,4].grouped(2) = [[1,2],[3,4]] [1,2,3,4,5].grouped(2) = [[1,2],[3,4],[5]] [1,2,3,4].grouped(5) = [[1,2,3,4]]Note:
grouped(size)is equivalent tosliding(size, size).- Specified by:
groupedin interfaceTraversable<K>- Parameters:
size- the block size; must be positive- Returns:
- an
Iteratorover blocks of elements
- If empty, the resulting
-
isDefinedAt
@Deprecated default boolean isDefinedAt(K key)
Deprecated.Description copied from interface:PartialFunctionTests whether a value is contained in the function's domain.- Specified by:
isDefinedAtin interfacePartialFunction<K,V>- Parameters:
key- a potential input to the function- Returns:
trueif the given value is contained in the function's domain,falseotherwise
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isDistinct
default boolean isDistinct()
Description copied from interface:TraversableIndicates whether this Traversable may contain only distinct elements.- Specified by:
isDistinctin interfaceTraversable<K>- Returns:
trueif this Traversable may contain only distinct elements,falseotherwise
-
init
Map<K,V> init()
Description copied from interface:TraversableReturns all elements of this Traversable except the last one.This is the dual of
Traversable.tail().- Specified by:
initin interfaceTraversable<K>- Returns:
- a new instance containing all elements except the last
-
initOption
Option<? extends Map<K,V>> initOption()
Description copied from interface:TraversableReturns all elements of this Traversable except the last one, wrapped in anOption.This is the dual of
Traversable.tailOption().- Specified by:
initOptionin interfaceTraversable<K>- Returns:
Some(traversable)if non-empty, orNoneif this Traversable is empty
-
orElse
Map<K,V> orElse(java.lang.Iterable<? extends Tuple2<K,V>> other)
Description copied from interface:TraversableReturns thisTraversableif it is non-empty; otherwise, returns the given alternative.- Specified by:
orElsein interfaceTraversable<K>- Parameters:
other- an alternativeTraversableto return if this is empty- Returns:
- this
Traversableif non-empty, otherwiseother
-
orElse
Map<K,V> orElse(@NonNull java.util.function.Supplier<? extends java.lang.Iterable<? extends Tuple2<K,V>>> supplier)
Description copied from interface:TraversableReturns thisTraversableif it is non-empty; otherwise, returns the result of evaluating the given supplier.- Specified by:
orElsein interfaceTraversable<K>- Parameters:
supplier- a supplier of an alternativeTraversableif this is empty- Returns:
- this
Traversableif non-empty, otherwise the result ofsupplier.get()
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partition
Tuple2<? extends Map<K,V>,? extends Map<K,V>> partition(@NonNull java.util.function.Predicate<? super Tuple2<K,V>> predicate)
Description copied from interface:TraversableSplits thisTraversableinto two partitions according to a predicate.The first partition contains all elements that satisfy the predicate, and the second contains all elements that do not. The original iteration order is preserved.
- Specified by:
partitionin interfaceTraversable<K>- Parameters:
predicate- a predicate used to classify elements- Returns:
- a
Tuple2containing the two resultingTraversableinstances
-
peek
Map<K,V> peek(@NonNull java.util.function.Consumer<? super Tuple2<K,V>> action)
Description copied from interface:ValuePerforms the givenactionon the first element if this is an eager implementation. Performs the givenactionon all elements (the first immediately, successive deferred), if this is a lazy implementation.
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replace
Map<K,V> replace(@NonNull Tuple2<K,V> currentElement, @NonNull Tuple2<K,V> newElement)
Description copied from interface:TraversableReplaces the first occurrence ofcurrentElementwithnewElement, if it exists.- Specified by:
replacein interfaceTraversable<K>- Parameters:
currentElement- the element to be replacednewElement- the replacement element- Returns:
- a new Traversable with the first occurrence of
currentElementreplaced bynewElement
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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.
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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 tonewValue- 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.
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replaceAll
Map<K,V> replaceAll(@NonNull java.util.function.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.
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replaceAll
Map<K,V> replaceAll(@NonNull Tuple2<K,V> currentElement, Tuple2<K,V> newElement)
Description copied from interface:TraversableReplaces all occurrences ofcurrentElementwithnewElement.- Specified by:
replaceAllin interfaceTraversable<K>- Parameters:
currentElement- the element to be replacednewElement- the replacement element- Returns:
- a new Traversable with all occurrences of
currentElementreplaced bynewElement
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retainAll
Map<K,V> retainAll(@NonNull java.lang.Iterable<? extends Tuple2<K,V>> elements)
Description copied from interface:TraversableRetains only the elements from this Traversable that are contained in the givenelements.- Specified by:
retainAllin interfaceTraversable<K>- Parameters:
elements- the elements to keep- Returns:
- a new Traversable containing only the elements present in
elements, in their original order
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scan
Map<K,V> scan(@NonNull Tuple2<K,V> zero, @NonNull java.util.function.BiFunction<? super Tuple2<K,V>,? super Tuple2<K,V>,? extends Tuple2<K,V>> operation)
Description copied from interface:TraversableComputes a prefix scan of the elements of this Traversable.The neutral element
zeromay be applied more than once.- Specified by:
scanin interfaceTraversable<K>- Parameters:
zero- the neutral element for the operatoroperation- an associative binary operator- Returns:
- a new Traversable containing the prefix scan of the elements
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slideBy
Iterator<? extends Map<K,V>> slideBy(@NonNull java.util.function.Function<? super Tuple2<K,V>,?> classifier)
Description copied from interface:TraversablePartitions thisTraversableinto consecutive non-overlapping windows according to a classification function.Each window contains elements with the same class, as determined by
classifier. Two consecutive elements belong to the same window only ifclassifierreturns equal values for both. Otherwise, the current window ends and a new window begins with the next element.Examples:
[].slideBy(Function.identity()) = [] [1,2,3,4,4,5].slideBy(Function.identity()) = [[1],[2],[3],[4,4],[5]] [1,2,3,10,12,5,7,20,29].slideBy(x -> x / 10) = [[1,2,3],[10,12],[5,7],[20,29]]- Specified by:
slideByin interfaceTraversable<K>- Parameters:
classifier- A function classifying elements into groups- Returns:
- An
Iteratorof windows (grouped elements)
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sliding
Iterator<? extends Map<K,V>> sliding(int size)
Description copied from interface:TraversableSlides a window of a givensizeover thisTraversablewith a step size of 1.This is equivalent to calling
Traversable.sliding(int, int)with a step size of 1.- Specified by:
slidingin interfaceTraversable<K>- Parameters:
size- a positive window size- Returns:
- An
Iteratorof windows, each containing up tosizeelements
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sliding
Iterator<? extends Map<K,V>> sliding(int size, int step)
Description copied from interface:TraversableSlides a window of a specificsizewith a givenstepover thisTraversable.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:
slidingin interfaceTraversable<K>- Parameters:
size- a positive window sizestep- a positive step size- Returns:
- an
Iteratorof windows with the given size and step
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span
Tuple2<? extends Map<K,V>,? extends Map<K,V>> span(@NonNull java.util.function.Predicate<? super Tuple2<K,V>> predicate)
Description copied from interface:TraversableSplits thisTraversableinto a prefix and remainder according to the givenpredicate.The first element of the returned
Tupleis the longest prefix of elements satisfyingpredicate, and the second element is the remaining elements.- Specified by:
spanin interfaceTraversable<K>- Parameters:
predicate- a predicate used to determine the prefix- Returns:
- a
Tuplecontaining the prefix and remainder
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tail
Map<K,V> tail()
Description copied from interface:TraversableReturns a newTraversablewithout its first element.- Specified by:
tailin interfaceTraversable<K>- Returns:
- a new
Traversablecontaining all elements except the first
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tailOption
Option<? extends Map<K,V>> tailOption()
Description copied from interface:TraversableReturns a newTraversablewithout its first element as anOption.- Specified by:
tailOptionin interfaceTraversable<K>- Returns:
Some(traversable)if non-empty, otherwiseNone
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take
Map<K,V> take(int n)
Description copied from interface:TraversableReturns the firstnelements of thisTraversable, or all elements ifnexceeds the length.Equivalent to
sublist(0, max(0, min(length(), n))), but safe forn < 0orn > length().If
n < 0, an empty instance is returned. Ifn > length(), the full instance is returned.- Specified by:
takein interfaceTraversable<K>- Parameters:
n- the number of elements to take- Returns:
- a new
Traversablecontaining the firstnelements
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takeRight
Map<K,V> takeRight(int n)
Description copied from interface:TraversableReturns the lastnelements of thisTraversable, or all elements ifnexceeds the length.Equivalent to
sublist(max(0, length() - n), length()), but safe forn < 0orn > length().If
n < 0, an empty instance is returned. Ifn > length(), the full instance is returned.- Specified by:
takeRightin interfaceTraversable<K>- Parameters:
n- the number of elements to take from the end- Returns:
- a new
Traversablecontaining the lastnelements
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takeUntil
Map<K,V> takeUntil(@NonNull java.util.function.Predicate<? super Tuple2<K,V>> predicate)
Description copied from interface:TraversableTakes elements from thisTraversableuntil the given predicate holds for an element.Equivalent to
takeWhile(predicate.negate()), but useful when using method references that cannot be negated directly.- Specified by:
takeUntilin interfaceTraversable<K>- Parameters:
predicate- a condition tested sequentially on the elements- Returns:
- a new
Traversablecontaining all elements before the first one that satisfies the predicate
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takeWhile
Map<K,V> takeWhile(@NonNull java.util.function.Predicate<? super Tuple2<K,V>> predicate)
Description copied from interface:TraversableTakes elements from thisTraversablewhile the given predicate holds.- Specified by:
takeWhilein interfaceTraversable<K>- Parameters:
predicate- a condition tested sequentially on the elements- Returns:
- a new
Traversablecontaining all elements up to (but not including) the first one that does not satisfy the predicate
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