Top Description Inners Fields Constructors Methods
org.pcollections

public final Class HashPMap<K, V>

extends AbstractUnmodifiableMap<K, V>
implements PMap<K, V>, Serializable
Class Inheritance
All Implemented Interfaces
java.io.Serializable, org.pcollections.PMap, java.util.Map
Imports
java.io.Serializable, java.util.AbstractSet, .Collection, .Iterator, .Map, .Objects, .Set
A persistent map from keys to values. Keys and values can be null.

This map uses a given integer map to map hashcodes to lists of elements with the same hashcode. Thus if all elements have the same hashcode, performance is reduced to that of an association list.

This implementation is thread-safe (assuming Java's AbstractMap and AbstractSet are thread-safe), although its iterators may not be.

Author
harold

Nested and Inner Type Summary

Modifier and TypeClass and Description
pack-priv static class
HashPMap.SequenceIterator<E>

Field Summary

Modifier and TypeField and Description
private transient Set<Map.Entry<K, V>>
entrySet

private final PMap<Integer, PSequence<Map.Entry<K, V>>>
intMap

private static final long
serialVersionUID

private final int
size

Constructor Summary

AccessConstructor and Description
private
HashPMap(final PMap<Integer, PSequence<Map.Entry<K, V>>> intMap, final int size)

Method Summary

Modifier and TypeMethod and Description
public boolean
containsKey(final Object
key whose presence in this map is to be tested
key)

Overrides java.util.AbstractMap.containsKey.

Implements java.util.Map.containsKey.

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

public static <K, V> HashPMap<K, V>

Returns:

a map backed by an empty version of intMap, i.e. backed by intMap.minusAll(intMap.keySet())
empty(final PMap<Integer, PSequence<Map.Entry<K, V>>> intMap)

public Set<Map.Entry<K, V>>
entrySet()

Implements abstract java.util.AbstractMap.entrySet.

Implements java.util.Map.entrySet.

Returns a Set view of the mappings contained in this map.

public V
get(final Object
the key whose associated value is to be returned
key)

Overrides java.util.AbstractMap.get.

Implements java.util.Map.get.

Returns the value to which the specified key is mapped, or null if this map contains no mapping for the key.

private PSequence<Map.Entry<K, V>>
getEntries(final int hash)

private static <K, V> int
keyIndexIn(final PSequence<Map.Entry<K, V>> entries, final Object key)

public HashPMap<K, V>
minus(final Object key)

Implements org.pcollections.PMap.minus.

public HashPMap<K, V>
minusAll(final Collection<?> keys)

Implements org.pcollections.PMap.minusAll.

public HashPMap<K, V>
plus(final K key, final V value)

Implements org.pcollections.PMap.plus.

public HashPMap<K, V>
plusAll(final Map<? extends K, ? extends V> map)

Implements org.pcollections.PMap.plusAll.

public int
size()

Overrides java.util.AbstractMap.size.

Implements java.util.Map.size.

Returns the number of key-value mappings in this map.

Inherited from org.pcollections.AbstractUnmodifiableMap:
clearcomputecomputeIfAbsentcomputeIfPresentmergeputputAllputIfAbsentremovereplacereplaceAll

Field Detail

entrySetback to summary
private transient Set<Map.Entry<K, V>> entrySet
intMapback to summary
private final PMap<Integer, PSequence<Map.Entry<K, V>>> intMap
serialVersionUIDback to summary
private static final long serialVersionUID
sizeback to summary
private final int size

Constructor Detail

HashPMapback to summary
private HashPMap(final PMap<Integer, PSequence<Map.Entry<K, V>>> intMap, final int size)

Method Detail

containsKeyback to summary
public boolean containsKey(final Object key)

Overrides java.util.AbstractMap.containsKey.

Implements java.util.Map.containsKey.

Doc from java.util.Map.containsKey.

Returns true if this map contains a mapping for the specified key. More formally, returns true if and only if this map contains a mapping for a key k such that Objects.equals(key, k). (There can be at most one such mapping.)

Parameters
key:Object

key whose presence in this map is to be tested

Returns:boolean

true if this map contains a mapping for the specified key

Annotations
@Override
emptyback to summary
public static <K, V> HashPMap<K, V> empty(final PMap<Integer, PSequence<Map.Entry<K, V>>> intMap)
Returns:HashPMap<K, V>

a map backed by an empty version of intMap, i.e. backed by intMap.minusAll(intMap.keySet())

entrySetback to summary
public Set<Map.Entry<K, V>> entrySet()

Implements abstract java.util.AbstractMap.entrySet.

Implements java.util.Map.entrySet.

Doc from java.util.Map.entrySet.

Returns a Set view of the mappings contained in this map. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's own remove operation, or through the setValue operation on a map entry returned by the iterator) the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Set.remove, removeAll, retainAll and clear operations. It does not support the add or addAll operations.

Returns:Set<Map.Entry<K, V>>

a set view of the mappings contained in this map

Annotations
@Override
getback to summary
public V get(final Object key)

Overrides java.util.AbstractMap.get.

Implements java.util.Map.get.

Doc from java.util.Map.get.

Returns the value to which the specified key is mapped, or null if this map contains no mapping for the key.

More formally, if this map contains a mapping from a key k to a value v such that Objects.equals(key, k), then this method returns v; otherwise it returns null. (There can be at most one such mapping.)

If this map permits null values, then a return value of null does not necessarily indicate that the map contains no mapping for the key; it's also possible that the map explicitly maps the key to null. The containsKey operation may be used to distinguish these two cases.

Parameters
key:Object

the key whose associated value is to be returned

Returns:V

the value to which the specified key is mapped, or null if this map contains no mapping for the key

Annotations
@Override
getEntriesback to summary
private PSequence<Map.Entry<K, V>> getEntries(final int hash)
keyIndexInback to summary
private static <K, V> int keyIndexIn(final PSequence<Map.Entry<K, V>> entries, final Object key)
minusback to summary
public HashPMap<K, V> minus(final Object key)

Implements org.pcollections.PMap.minus.

Returns:HashPMap<K, V>

Doc from org.pcollections.PMap.minus.

a map with the mappings of this but with no value for key

minusAllback to summary
public HashPMap<K, V> minusAll(final Collection<?> keys)

Implements org.pcollections.PMap.minusAll.

Returns:HashPMap<K, V>

Doc from org.pcollections.PMap.minusAll.

a map with the mappings of this but with no value for any element of keys

plusback to summary
public HashPMap<K, V> plus(final K key, final V value)

Implements org.pcollections.PMap.plus.

Returns:HashPMap<K, V>

Doc from org.pcollections.PMap.plus.

a map with the mappings of this but with key mapped to value

plusAllback to summary
public HashPMap<K, V> plusAll(final Map<? extends K, ? extends V> map)

Implements org.pcollections.PMap.plusAll.

Returns:HashPMap<K, V>

Doc from org.pcollections.PMap.plusAll.

this combined with map, with map's mappings used for any keys in both map and this

sizeback to summary
public int size()

Overrides java.util.AbstractMap.size.

Implements java.util.Map.size.

Doc from java.util.Map.size.

Returns the number of key-value mappings in this map. If the map contains more than Integer.MAX_VALUE elements, returns Integer.MAX_VALUE.

Returns:int

the number of key-value mappings in this map

Annotations
@Override
org.pcollections back to summary

pack-priv Class HashPMap.SequenceIterator<E>

extends Object
implements Iterator<E>
Class Inheritance
All Implemented Interfaces
java.util.Iterator

Field Summary

Modifier and TypeField and Description
private final Iterator<PSequence<E>>
i

private PSequence<E>
seq

Constructor Summary

AccessConstructor and Description
pack-priv
SequenceIterator(Iterator<PSequence<E>> i)

Method Summary

Modifier and TypeMethod and Description
public boolean
hasNext()

Implements java.util.Iterator.hasNext.

Returns true if the iteration has more elements.

public E
next()

Implements java.util.Iterator.next.

Returns the next element in the iteration.

public void
remove()

Overrides default java.util.Iterator.remove.

Removes from the underlying collection the last element returned by this iterator (optional operation).

Inherited from java.lang.Object:
cloneequalsfinalizegetClasshashCodenotifynotifyAlltoStringwaitwaitwait

Field Detail

iback to summary
private final Iterator<PSequence<E>> i
seqback to summary
private PSequence<E> seq

Constructor Detail

SequenceIteratorback to summary
pack-priv SequenceIterator(Iterator<PSequence<E>> i)

Method Detail

hasNextback to summary
public boolean hasNext()

Implements java.util.Iterator.hasNext.

Doc from java.util.Iterator.hasNext.

Returns true if the iteration has more elements. (In other words, returns true if next would return an element rather than throwing an exception.)

Returns:boolean

true if the iteration has more elements

nextback to summary
public E next()

Implements java.util.Iterator.next.

Doc from java.util.Iterator.next.

Returns the next element in the iteration.

Returns:E

the next element in the iteration

removeback to summary
public void remove()

Overrides default java.util.Iterator.remove.

Doc from java.util.Iterator.remove.

Removes from the underlying collection the last element returned by this iterator (optional operation). This method can be called only once per call to next.

The behavior of an iterator is unspecified if the underlying collection is modified while the iteration is in progress in any way other than by calling this method, unless an overriding class has specified a concurrent modification policy.

The behavior of an iterator is unspecified if this method is called after a call to the forEachRemaining method.