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 and Description
static class	PersistentHashMap.MutableHashMap<K,V>

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

UnmodMap.UnEntry<K,V>

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

Map.Entry<K,V>

Field Summary

Fields

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

Method Summary

Modifier and Type	Method and Description
PersistentHashMap<K,V>	assoc(K key, V val) Returns a new map with the given key/value added
static <K,V> PersistentHashMap<K,V>	empty()
static <K,V> PersistentHashMap<K,V>	empty(Equator<K> e)
static <K,V> PersistentHashMap.MutableHashMap<K,V>	emptyMutable() Works around some type inference limitations of Java 8.
static <K,V> PersistentHashMap.MutableHashMap<K,V>	emptyMutable(Equator<K> e) Works around some type inference limitations of Java 8.
Option<UnmodMap.UnEntry<K,V>>	entry(K key) Returns an option of the key/value pair associated with this key
Equator<K>	equator() Returns the Equator used by this map for equals comparisons and hashCodes
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.
UnmodIterator<K>	keyIterator()
PersistentHashMap.MutableHashMap<K,V>	mutable() Returns a mutable version of this mutable map.
static <K,V> PersistentHashMap<K,V>	of(Iterable<Map.Entry<K,V>> kvPairs) Returns a new PersistentHashMap of the given keys and their paired values.
static <K,V> PersistentHashMap<K,V>	ofEq(Equator<K> eq, 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.
UnmodIterator<V>	valIterator()
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.ImMap

assoc, entrySet, keySet

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

containsKey, get, getOrElse

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

Methods inherited from interface java.util.Map

equals, forEach, getOrDefault, hashCode

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

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

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

toImList, toImMap, toImRrbt, toImSet, toImSortedMap, toImSortedSet, toMutableList, toMutableMap, toMutableRrbt, toMutableSet, toMutableSortedMap, toMutableSortedSet

Field Detail

EMPTY

public static final PersistentHashMap<Object,Object> EMPTY

Method Detail

empty

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

emptyMutable

public static <K,V> PersistentHashMap.MutableHashMap<K,V> emptyMutable()

Works around some type inference limitations of Java 8.

empty

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

emptyMutable

public static <K,V> PersistentHashMap.MutableHashMap<K,V> emptyMutable(Equator<K> e)

Works around some type inference limitations of Java 8.

ofEq

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

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

of

public static <K,V> PersistentHashMap<K,V> of(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

public Equator<K> equator()

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

Specified by:

equator in interface BaseUnsortedMap<K,V>

assoc

public 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

public PersistentHashMap.MutableHashMap<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

public 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

public 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<UnmodMap.UnEntry<K,V>>

Specified by:

iterator in interface UnmodIterable<UnmodMap.UnEntry<K,V>>

keyIterator

public UnmodIterator<K> keyIterator()

Specified by:

keyIterator in interface UnmodMap<K,V>

valIterator

public 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

public 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>