Package org.organicdesign.fp.collections

Class PersistentHashMap<K,V>

java.lang.Object

org.organicdesign.fp.collections.AbstractUnmodIterable<UnmodMap.UnEntry<K,V>>

org.organicdesign.fp.collections.AbstractUnmodMap<K,V>

org.organicdesign.fp.collections.PersistentHashMap<K,V>

All Implemented Interfaces:

Serializable, Iterable<UnmodMap.UnEntry<K,V>>, Map<K,V>, BaseMap<K,V>, BaseUnsortedMap<K,V>, ImMap<K,V>, Sized, UnmodIterable<UnmodMap.UnEntry<K,V>>, UnmodMap<K,V>, Transformable<UnmodMap.UnEntry<K,V>>

public class PersistentHashMap<K,V>
extends AbstractUnmodMap<K,V>
implements ImMap<K,V>, Serializable

Rich Hickey's immutable rendition of Phil Bagwell's Hash Array Mapped Trie. Uses path copying for persistence, HashCollision leaves vs. extended hashing, Node polymorphism vs. conditionals, No sub-tree pools or root-resizing. Any errors are my own (said Rich, but now says Glen 2015-06-06). This file is a derivative work based on a Clojure collection licensed under the Eclipse Public License 1.0 Copyright Rich Hickey. Errors are Glen Peterson's.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	PersistentHashMap.MutHashMap<K,V>

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K extends Object,V extends Object>

Nested classes/interfaces inherited from interface org.organicdesign.fp.collections.UnmodIterable

UnmodIterable.UnIterable

Nested classes/interfaces inherited from interface org.organicdesign.fp.collections.UnmodMap

UnmodMap.UnEntry<K,V>

Field Summary

Fields

Modifier and Type	Field	Description
static @NotNull PersistentHashMap<Object,Object>	EMPTY

Method Summary

Modifier and Type	Method	Description
@NotNull PersistentHashMap<K,V>	assoc(K key, V val)	Returns a new map with the given key/value added
static <K,V> @NotNull PersistentHashMap<K,V>	empty()
static <K,V> @NotNull PersistentHashMap<K,V>	empty(@Nullable Equator<K> e)
static <K,V> @NotNull PersistentHashMap.MutHashMap<K,V>	emptyMutable()	Works around some type inference limitations of Java 8.
static <K,V> @NotNull PersistentHashMap.MutHashMap<K,V>	emptyMutable(Equator<K> e)	Works around some type inference limitations of Java 8.
@NotNull Option<UnmodMap.UnEntry<K,V>>	entry(K key)	Returns an option of the key/value pair associated with this key
@NotNull Equator<K>	equator()	Returns the Equator used by this map for equals comparisons and hashCodes
@NotNull UnmodIterator<UnmodMap.UnEntry<K,V>>	iterator()	A one-time use, mutable, not-thread-safe way to get each value of the underling collection in turn.
@NotNull UnmodIterator<K>	keyIterator()
@NotNull PersistentHashMap.MutHashMap<K,V>	mutable()	Returns a mutable version of this mutable map.
static <K,V> @NotNull PersistentHashMap<K,V>	of(@Nullable Iterable<Map.Entry<K,V>> kvPairs)	Returns a new PersistentHashMap of the given keys and their paired values.
static <K,V> @NotNull PersistentHashMap<K,V>	ofEq(Equator<K> eq, @Nullable Iterable<Map.Entry<K,V>> es)	Returns a new PersistentHashMap of the given keys and their paired values, skipping any null Entries.
int	size()	Returns the number of items in this collection or iterable.
@NotNull UnmodIterator<V>	valIterator()
@NotNull PersistentHashMap<K,V>	without(K key)	Returns a new map with the given key/value removed

Methods inherited from class org.organicdesign.fp.collections.AbstractUnmodMap

equals

Methods inherited from class org.organicdesign.fp.collections.AbstractUnmodIterable

hashCode, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.organicdesign.fp.collections.BaseMap

containsKey, get, getOrElse

Methods inherited from interface org.organicdesign.fp.collections.ImMap

assoc, entrySet, keySet

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Methods inherited from interface java.util.Map

equals, forEach, getOrDefault, hashCode

Methods inherited from interface org.organicdesign.fp.xform.Transformable

any, toImList, toImMap, toImRrbt, toImSet, toImSortedMap, toImSortedSet, toMutList, toMutMap, toMutRrbt, toMutSet, toMutSortedMap, toMutSortedSet

Methods inherited from interface org.organicdesign.fp.collections.UnmodIterable

concat, drop, dropWhile, filter, flatMap, fold, foldUntil, head, map, precat, take, takeWhile, whereNonNull

Methods inherited from interface org.organicdesign.fp.collections.UnmodMap

clear, compute, computeIfAbsent, computeIfPresent, containsValue, isEmpty, merge, put, putAll, putIfAbsent, remove, remove, replace, replace, replaceAll, values

Field Detail

EMPTY

@NotNull
public static final @NotNull PersistentHashMap<Object,Object> EMPTY

Method Detail

empty

@NotNull
public static <K,V> @NotNull PersistentHashMap<K,V> empty()

emptyMutable

@NotNull
public static <K,V> @NotNull PersistentHashMap.MutHashMap<K,V> emptyMutable()

Works around some type inference limitations of Java 8.

empty

@NotNull
public static <K,V> @NotNull PersistentHashMap<K,V> empty(@Nullable
                                                                      @Nullable Equator<K> e)

emptyMutable

@NotNull
public static <K,V> @NotNull PersistentHashMap.MutHashMap<K,V> emptyMutable(Equator<K> e)

Works around some type inference limitations of Java 8.

ofEq

@NotNull
public static <K,V> @NotNull PersistentHashMap<K,V> ofEq(Equator<K> eq,
                                                                     @Nullable
                                                                     @Nullable Iterable<Map.Entry<K,V>> es)

Returns a new PersistentHashMap of the given keys and their paired values, skipping any null Entries.

of

@NotNull
public static <K,V> @NotNull PersistentHashMap<K,V> of(@Nullable
                                                                   @Nullable Iterable<Map.Entry<K,V>> kvPairs)

Returns a new PersistentHashMap of the given keys and their paired values. There is also a varargs version of this method: StaticImports.map(Map.Entry...). Use the StaticImports.tup(Object, Object) method to define key/value pairs briefly and easily.

Parameters:

kvPairs - Key/value pairs (to go into the map). In the case of a duplicate key, later values in the input list overwrite the earlier ones. The resulting map can contain zero or one null key and any number of null values. Null k/v pairs will be silently ignored.

Returns:

a new PersistentHashMap of the given key/value pairs

equator

@NotNull
public @NotNull Equator<K> equator()

Returns the Equator used by this map for equals comparisons and hashCodes

Specified by:

equator in interface BaseUnsortedMap<K,V>

assoc

@NotNull
public @NotNull PersistentHashMap<K,V> assoc(K key,
                                                   V val)

Description copied from interface: ImMap

Returns a new map with the given key/value added

Specified by:

assoc in interface BaseMap<K,V>

Specified by:

assoc in interface ImMap<K,V>

mutable

@NotNull
public @NotNull PersistentHashMap.MutHashMap<K,V> mutable()

Description copied from interface: ImMap

Returns a mutable version of this mutable map.

Specified by:

mutable in interface ImMap<K,V>

entry

@NotNull
public @NotNull Option<UnmodMap.UnEntry<K,V>> entry(K key)

Description copied from interface: BaseMap

Returns an option of the key/value pair associated with this key

Specified by:

entry in interface BaseMap<K,V>

iterator

@NotNull
public @NotNull UnmodIterator<UnmodMap.UnEntry<K,V>> iterator()

Description copied from interface: UnmodIterable

A one-time use, mutable, not-thread-safe way to get each value of the underling collection in turn. I experimented with various thread-safe alternatives, but the JVM is optimized around iterators so this is the lowest common denominator of collection iteration, even though iterators are inherently mutable.

Specified by:

iterator in interface Iterable<K>

Specified by:

iterator in interface UnmodIterable<K>

keyIterator

@NotNull
public @NotNull UnmodIterator<K> keyIterator()

Specified by:

keyIterator in interface UnmodMap<K,V>

valIterator

@NotNull
public @NotNull UnmodIterator<V> valIterator()

Specified by:

valIterator in interface UnmodMap<K,V>

size

public int size()

Returns the number of items in this collection or iterable.

Specified by:

size in interface Map<K,V>

Specified by:

size in interface Sized

without

@NotNull
public @NotNull PersistentHashMap<K,V> without(K key)

Description copied from interface: ImMap

Returns a new map with the given key/value removed

Specified by:

without in interface BaseMap<K,V>

Specified by:

without in interface ImMap<K,V>