public final class HashMap<K,V> extends Object implements Kind2<HashMap<?,?>,K,V>, Serializable
HashMap
implementation based on a
Hash array mapped trie (HAMT).λ.Memoized
Modifier and Type | Method and Description |
---|---|
<K2,V2> HashMap<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. |
static <K,V> Collector<Tuple2<K,V>,ArrayList<Tuple2<K,V>>,HashMap<K,V>> |
collector()
Returns a
Collector which may be used in conjunction with
Stream.collect(java.util.stream.Collector) to obtain a HashMap . |
boolean |
containsKey(K key)
Returns
true if this map contains a mapping for the specified key. |
M |
distinct()
Returns a new version of this which contains no duplicates.
|
M |
distinctBy(Comparator<? super Tuple2<K,V>> comparator)
Returns a new version of this which contains no duplicates.
|
<U> M |
distinctBy(Function<? super Tuple2<K,V>,? extends U> keyExtractor)
Returns a new version of this which contains no duplicates.
|
M |
drop(long n)
Drops the first n elements of this or all elements, if this length < n.
|
M |
dropRight(long n)
Drops the last n elements of this or all elements, if this length < n.
|
M |
dropUntil(Predicate<? super Tuple2<K,V>> predicate)
Drops elements until the predicate holds for the current element.
|
M |
dropWhile(Predicate<? super Tuple2<K,V>> predicate)
Drops elements while the predicate holds for the current element.
|
static <K,V> HashMap<K,V> |
empty() |
boolean |
equals(Object o)
Clarifies that values have a proper equals() method implemented.
|
static <K,V> HashMap<K,V> |
fill(int n,
Supplier<? extends Tuple2<? extends K,? extends V>> s)
Returns an HashMap containing
n values supplied by a given Supplier s . |
M |
filter(Predicate<? super Tuple2<K,V>> predicate)
Returns a new traversable consisting of all elements which satisfy the given predicate.
|
<K2,V2> HashMap<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. |
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. |
<C> Map<C,M> |
groupBy(Function<? super Tuple2<K,V>,? extends C> classifier)
Groups this elements by classifying the elements.
|
Iterator<M> |
grouped(long size)
Groups this
Traversable into fixed size blocks. |
int |
hashCode()
Clarifies that values have a proper hashCode() method implemented.
|
Tuple2<K,V> |
head()
Returns the first element of a non-empty Traversable.
|
HashMap<K,V> |
init()
Dual of Traversable.tail(), returning all elements except the last.
|
Option<M> |
initOption()
Dual of Traversable.tailOption(), returning all elements except the last as
Option . |
boolean |
isEmpty()
Checks if this Traversable is empty.
|
Iterator<Tuple2<K,V>> |
iterator()
An iterator by means of head() and tail().
|
Set<K> |
keySet()
Returns the keys contained in this map.
|
<K2,V2> HashMap<K2,V2> |
map(BiFunction<? super K,? super V,Tuple2<K2,V2>> mapper)
Maps the entries of this
Map to form a new Map . |
<V2> HashMap<K,V2> |
mapValues(Function<? super V,? extends V2> valueMapper)
Maps the values of this
Map while preserving the corresponding keys. |
M |
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> |
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> HashMap<K,V> |
narrow(HashMap<? extends K,? extends V> hashMap)
Narrows a widened
HashMap<? extends K, ? extends V> to HashMap<K, V>
by performing a type safe-cast. |
static <K,V> HashMap<K,V> |
of(K key,
V value)
Returns a singleton
HashMap , i.e. |
static <K,V> HashMap<K,V> |
of(Object... pairs)
Creates a HashMap of the given list of key-value pairs.
|
static <K,V> HashMap<K,V> |
of(Tuple2<? extends K,? extends V> entry)
Returns a singleton
HashMap , i.e. |
static <K,V> HashMap<K,V> |
ofAll(Map<? extends K,? extends V> map)
Returns a
HashMap , from a source java.util.Map. |
static <K,V> HashMap<K,V> |
ofEntries(Iterable<? extends Tuple2<? extends K,? extends V>> entries)
Creates a HashMap of the given entries.
|
static <K,V> HashMap<K,V> |
ofEntries(Map.Entry<? extends K,? extends V>... entries)
Creates a HashMap of the given entries.
|
static <K,V> HashMap<K,V> |
ofEntries(Tuple2<? extends K,? extends V>... entries)
Creates a HashMap of the given entries.
|
Tuple2<M,M> |
partition(Predicate<? super Tuple2<K,V>> predicate)
Creates a partition of this
Traversable by splitting this elements in two in distinct tarversables
according to a predicate. |
M |
peek(Consumer<? super Tuple2<K,V>> action)
Performs the given
action on the first element if this is an eager implementation. |
HashMap<K,V> |
put(K key,
V value)
Associates the specified value with the specified key in this map.
|
M |
put(Tuple2<? extends K,? extends V> entry)
Convenience method for
put(entry._1, entry._2) . |
HashMap<K,V> |
remove(K key)
Removes the mapping for a key from this map if it is present.
|
HashMap<K,V> |
removeAll(Iterable<? extends K> keys)
Removes the mapping for a key from this map if it is present.
|
M |
replace(Tuple2<K,V> currentElement,
Tuple2<K,V> newElement)
Replaces the first occurrence (if exists) of the given currentElement with newElement.
|
M |
replaceAll(Tuple2<K,V> currentElement,
Tuple2<K,V> newElement)
Replaces all occurrences of the given currentElement with newElement.
|
HashMap<K,V> |
retainAll(Iterable<? extends Tuple2<K,V>> elements)
Keeps all occurrences of the given elements from this.
|
M |
scan(Tuple2<K,V> zero,
BiFunction<? super Tuple2<K,V>,? super Tuple2<K,V>,? extends Tuple2<K,V>> operation)
Computes a prefix scan of the elements of the collection.
|
int |
size()
Computes the number of elements of this Traversable.
|
Iterator<M> |
sliding(long size)
Slides a window of a specific
size and step size 1 over this Traversable by calling
Traversable.sliding(long, long) . |
Iterator<M> |
sliding(long size,
long step)
Slides a window of a specific
size and step size over this Traversable . |
Tuple2<M,M> |
span(Predicate<? super Tuple2<K,V>> predicate)
Returns a tuple where the first element is the longest prefix of elements that satisfy the given
predicate and the second element is the remainder. |
String |
stringPrefix()
Returns the name of this Value type, which is used by toString().
|
static <K,V> HashMap<K,V> |
tabulate(int n,
Function<? super Integer,? extends Tuple2<? extends K,? extends V>> f)
Returns an HashMap containing
n values of a given Function f
over a range of integer values from 0 to n - 1 . |
HashMap<K,V> |
tail()
Drops the first element of a non-empty Traversable.
|
Option<M> |
tailOption()
Drops the first element of a non-empty Traversable and returns an
Option . |
M |
take(long n)
Takes the first n elements of this or all elements, if this length < n.
|
M |
takeRight(long n)
Takes the last n elements of this or all elements, if this length < n.
|
M |
takeUntil(Predicate<? super Tuple2<K,V>> predicate)
Takes elements until the predicate holds for the current element.
|
M |
takeWhile(Predicate<? super Tuple2<K,V>> predicate)
Takes elements while the predicate holds for the current element.
|
HashMap<K,V> |
toJavaMap()
Converts this Javaslang
Map to a java.util.Map while preserving characteristics
like insertion order (LinkedHashMap ) and sort order (SortedMap ). |
String |
toString()
Clarifies that values have a proper toString() method implemented.
|
Seq<V> |
values() |
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
apply, contains, containsValue, flatMap, foldRight, forEach, hasDefiniteSize, headOption, isTraversableAgain, length, map, narrow, scanLeft, scanRight, spliterator, transform, traverse, unzip, unzip, unzip3, unzip3, zip, zipAll, zipWithIndex
average, containsAll, count, existsUnique, find, findLast, foldLeft, get, hash, isSingleValued, last, lastOption, max, maxBy, maxBy, min, minBy, minBy, mkString, mkString, mkString, narrow, nonEmpty, product, reduceLeft, reduceLeftOption, reduceRight, reduceRightOption, sum
fold, reduce, reduceOption
corresponds, eq, exists, forAll, forEach, getOption, getOrElse, getOrElse, getOrElseThrow, getOrElseTry, narrow, out, out, stderr, stdout, toArray, toCharSeq, toJavaArray, toJavaArray, toJavaCollection, toJavaList, toJavaList, toJavaMap, toJavaMap, toJavaOptional, toJavaSet, toJavaSet, toJavaStream, toLeft, toLeft, toList, toMap, toOption, toQueue, toRight, toRight, toSet, toStack, toStream, toTree, toTry, toTry, toVector
andThen, arity, compose, curried, identity, lift, memoized, of, reversed, tupled
isMemoized
public static <K,V> Collector<Tuple2<K,V>,ArrayList<Tuple2<K,V>>,HashMap<K,V>> collector()
Collector
which may be used in conjunction with
Stream.collect(java.util.stream.Collector)
to obtain a HashMap
.K
- The key typeV
- The value typeHashMap
Collector.public static <K,V> HashMap<K,V> empty()
public static <K,V> HashMap<K,V> narrow(HashMap<? extends K,? extends V> hashMap)
HashMap<? extends K, ? extends V>
to HashMap<K, V>
by performing a type safe-cast. This is eligible because immutable/read-only
collections are covariant.K
- Key typeV
- Value typehashMap
- A HashMap
.hashMap
instance as narrowed type HashMap<K, V>
.public static <K,V> HashMap<K,V> of(Tuple2<? extends K,? extends V> entry)
HashMap
, i.e. a HashMap
of one element.K
- The key typeV
- The value typeentry
- A map entry.public static <K,V> HashMap<K,V> ofAll(Map<? extends K,? extends V> map)
HashMap
, from a source java.util.Map.K
- The key typeV
- The value typemap
- A map entry.public static <K,V> HashMap<K,V> of(K key, V value)
HashMap
, i.e. a HashMap
of one element.K
- The key typeV
- The value typekey
- A singleton map key.value
- A singleton map value.public static <K,V> HashMap<K,V> of(Object... pairs)
K
- The key typeV
- The value typepairs
- A list of key-value pairspublic static <K,V> HashMap<K,V> tabulate(int n, Function<? super Integer,? extends Tuple2<? extends K,? extends V>> f)
n
values of a given Function f
over a range of integer values from 0 to n - 1
.K
- The key typeV
- The value typen
- The number of elements in the HashMapf
- The Function computing element valuesf(0),f(1), ..., f(n - 1)
NullPointerException
- if f
is nullpublic static <K,V> HashMap<K,V> fill(int n, Supplier<? extends Tuple2<? extends K,? extends V>> s)
n
values supplied by a given Supplier s
.K
- The key typeV
- The value typen
- The number of elements in the HashMaps
- The Supplier computing element valuesn
, where each element contains the result supplied by s
.NullPointerException
- if s
is null@SafeVarargs public static <K,V> HashMap<K,V> ofEntries(Map.Entry<? extends K,? extends V>... entries)
K
- The key typeV
- The value typeentries
- Map entries@SafeVarargs public static <K,V> HashMap<K,V> ofEntries(Tuple2<? extends K,? extends V>... entries)
K
- The key typeV
- The value typeentries
- Map entriespublic static <K,V> HashMap<K,V> ofEntries(Iterable<? extends Tuple2<? extends K,? extends V>> entries)
K
- The key typeV
- The value typeentries
- Map entriespublic <K2,V2> HashMap<K2,V2> bimap(Function<? super K,? extends K2> keyMapper, Function<? super V,? extends V2> valueMapper)
Map
Map
to a new Map
with different component type by applying a function to its elements.bimap
in interface Map<K,V>
K2
- key's component type of the map resultV2
- value's component type of the map resultkeyMapper
- 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
Map
public boolean containsKey(K key)
Map
true
if this map contains a mapping for the specified key.containsKey
in interface Map<K,V>
key
- key whose presence in this map is to be testedtrue
if this map contains a mapping for the specified keypublic <K2,V2> HashMap<K2,V2> flatMap(BiFunction<? super K,? super V,? extends Iterable<Tuple2<K2,V2>>> mapper)
Map
Map
to a new Map
with different component type.public Option<V> get(K key)
Map
Some
of value to which the specified key
is mapped, or None
if this map contains no mapping for the key.public Tuple2<K,V> head()
Traversable
head
in interface Traversable<Tuple2<K,V>>
public HashMap<K,V> init()
Traversable
public boolean isEmpty()
Traversable
public Iterator<Tuple2<K,V>> iterator()
Traversable
public Set<K> keySet()
Map
public <K2,V2> HashMap<K2,V2> map(BiFunction<? super K,? super V,Tuple2<K2,V2>> mapper)
Map
Map
to form a new Map
.public <V2> HashMap<K,V2> mapValues(Function<? super V,? extends V2> valueMapper)
Map
Map
while preserving the corresponding keys.public HashMap<K,V> put(K key, V value)
Map
public HashMap<K,V> remove(K key)
Map
public HashMap<K,V> removeAll(Iterable<? extends K> keys)
Map
public HashMap<K,V> retainAll(Iterable<? extends Tuple2<K,V>> elements)
Traversable
public int size()
Traversable
Same as Traversable.length()
.
public HashMap<K,V> tail()
Traversable
public HashMap<K,V> toJavaMap()
Map
Map
to a java.util.Map
while preserving characteristics
like insertion order (LinkedHashMap
) and sort order (SortedMap
).public int hashCode()
Value
See Object.hashCode().
public boolean equals(Object o)
Value
public String stringPrefix()
Value
stringPrefix
in interface Value<Tuple2<K,V>>
public String toString()
Value
See Object.toString().
public M put(Tuple2<? extends K,? extends V> entry)
Map
put(entry._1, entry._2)
.public M distinct()
Traversable
equals
.distinct
in interface Map<K,V>
distinct
in interface Traversable<Tuple2<K,V>>
Traversable
containing this elements without duplicatespublic M distinctBy(Comparator<? super Tuple2<K,V>> comparator)
Traversable
comparator
.distinctBy
in interface Map<K,V>
distinctBy
in interface Traversable<Tuple2<K,V>>
comparator
- A comparatorTraversable
containing this elements without duplicatespublic <U> M distinctBy(Function<? super Tuple2<K,V>,? extends U> keyExtractor)
Traversable
equals
.
The elements of the result are determined in the order of their occurrence - first match wins.
distinctBy
in interface Map<K,V>
distinctBy
in interface Traversable<Tuple2<K,V>>
U
- key typekeyExtractor
- A key extractorTraversable
containing this elements without duplicatespublic M drop(long n)
Traversable
drop
in interface Map<K,V>
drop
in interface Traversable<Tuple2<K,V>>
n
- The number of elements to drop.public M dropRight(long n)
Traversable
dropRight
in interface Map<K,V>
dropRight
in interface Traversable<Tuple2<K,V>>
n
- The number of elements to drop.public M dropUntil(Predicate<? super Tuple2<K,V>> predicate)
Traversable
Note: This is essentially the same as dropWhile(predicate.negate())
. It is intended to be used with
method references, which cannot be negated directly.
dropUntil
in interface Map<K,V>
dropUntil
in interface Traversable<Tuple2<K,V>>
predicate
- A condition tested subsequently for this elements.public M dropWhile(Predicate<? super Tuple2<K,V>> predicate)
Traversable
dropWhile
in interface Map<K,V>
dropWhile
in interface Traversable<Tuple2<K,V>>
predicate
- A condition tested subsequently for this elements starting with the first.public M filter(Predicate<? super Tuple2<K,V>> predicate)
Traversable
filter
in interface Map<K,V>
filter
in interface Traversable<Tuple2<K,V>>
predicate
- A predicatepublic <C> Map<C,M> groupBy(Function<? super Tuple2<K,V>,? extends C> classifier)
Traversable
groupBy
in interface Map<K,V>
groupBy
in interface Traversable<Tuple2<K,V>>
C
- classified class typeclassifier
- A function which classifies elements into classespublic Iterator<M> grouped(long size)
Traversable
Traversable
into fixed size blocks.
Let length be the length of this Iterable. Then grouped is defined as follows:
this.isEmpty()
, the resulting Iterator
is empty.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.size > length
, the resulting Iterator
will contain one block of size length
.
[].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(long, long), i.e.
grouped(size)
is the same as sliding(size, size)
.grouped
in interface Map<K,V>
grouped
in interface Traversable<Tuple2<K,V>>
size
- a positive block sizepublic Option<M> initOption()
Traversable
Option
.initOption
in interface Map<K,V>
initOption
in interface Traversable<Tuple2<K,V>>
Some(traversable)
or None
if this is empty.public Option<M> tailOption()
Traversable
Option
.tailOption
in interface Map<K,V>
tailOption
in interface Traversable<Tuple2<K,V>>
Some(traversable)
or None
if this is empty.public M take(long n)
Traversable
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.
take
in interface Map<K,V>
take
in interface Traversable<Tuple2<K,V>>
n
- The number of elements to take.public M takeRight(long n)
Traversable
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.
takeRight
in interface Map<K,V>
takeRight
in interface Traversable<Tuple2<K,V>>
n
- The number of elements to take.public M takeUntil(Predicate<? super Tuple2<K,V>> predicate)
Traversable
Note: This is essentially the same as takeWhile(predicate.negate())
. It is intended to be used with
method references, which cannot be negated directly.
takeUntil
in interface Map<K,V>
takeUntil
in interface Traversable<Tuple2<K,V>>
predicate
- A condition tested subsequently for this elements.public M takeWhile(Predicate<? super Tuple2<K,V>> predicate)
Traversable
takeWhile
in interface Map<K,V>
takeWhile
in interface Traversable<Tuple2<K,V>>
predicate
- A condition tested subsequently for the contained elements.public M merge(Map<? extends K,? extends V> that)
Map
this
map and that
map.
If collisions occur, the value of this
map is taken.
public <U extends V> M merge(Map<? extends K,U> that, BiFunction<? super V,? super U,? extends V> collisionResolution)
Map
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.
public Tuple2<M,M> partition(Predicate<? super Tuple2<K,V>> predicate)
Traversable
Traversable
by splitting this elements in two in distinct tarversables
according to a predicate.partition
in interface Map<K,V>
partition
in interface Traversable<Tuple2<K,V>>
predicate
- A predicate which classifies an element if it is in the first or the second traversable.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.public M peek(Consumer<? super Tuple2<K,V>> action)
Value
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.public M replace(Tuple2<K,V> currentElement, Tuple2<K,V> newElement)
Traversable
replace
in interface Map<K,V>
replace
in interface Traversable<Tuple2<K,V>>
currentElement
- An element to be substituted.newElement
- A replacement for currentElement.public M replaceAll(Tuple2<K,V> currentElement, Tuple2<K,V> newElement)
Traversable
replaceAll
in interface Map<K,V>
replaceAll
in interface Traversable<Tuple2<K,V>>
currentElement
- An element to be substituted.newElement
- A replacement for currentElement.public M scan(Tuple2<K,V> zero, BiFunction<? super Tuple2<K,V>,? super Tuple2<K,V>,? extends Tuple2<K,V>> operation)
Traversable
scan
in interface Map<K,V>
scan
in interface Traversable<Tuple2<K,V>>
zero
- neutral element for the operator opoperation
- the associative operator for the scanpublic Iterator<M> sliding(long size)
Traversable
size
and step size 1 over this Traversable
by calling
Traversable.sliding(long, long)
.sliding
in interface Map<K,V>
sliding
in interface Traversable<Tuple2<K,V>>
size
- a positive window sizepublic Iterator<M> sliding(long size, long step)
Traversable
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]]
sliding
in interface Map<K,V>
sliding
in interface Traversable<Tuple2<K,V>>
size
- a positive window sizestep
- a positive step sizepublic Tuple2<M,M> span(Predicate<? super Tuple2<K,V>> predicate)
Traversable
predicate
and the second element is the remainder.span
in interface Map<K,V>
span
in interface Traversable<Tuple2<K,V>>
predicate
- A predicate.Copyright © 2016. All Rights Reserved.