fj.data

Class HashMap<K,V>

java.lang.Object

fj.data.HashMap<K,V>

All Implemented Interfaces:

java.lang.Iterable<K>

public final class HashMap<K,V>
extends java.lang.Object
implements java.lang.Iterable<K>

A mutable hash map providing O(1) lookup.

See Also:

HashMap

Constructor Summary

Constructors

Constructor and Description
HashMap(Equal<K> e, Hash<K> h) Construct a hash map with the given equality and hashing strategy.
HashMap(Equal<K> e, Hash<K> h, int initialCapacity) Construct a hash map with the given equality and hashing strategy.
HashMap(Equal<K> e, Hash<K> h, int initialCapacity, float loadFactor) Construct a hash map with the given equality and hashing strategy.
HashMap(java.util.Map<K,V> map)
HashMap(java.util.Map<K,V> map, Equal<K> e, Hash<K> h)

Method Summary

Methods

Modifier and Type	Method and Description
void	clear() Clear all entries from this hash map.
boolean	contains(K k) Determines if the given key value exists in this hash map.
void	delete(K k) Deletes the entry in the hash map that corresponds to the given key.
boolean	eq(K k1, K k2) Compare two key values for equality using the underlying equality strategy.
void	foreach(Effect<P2<K,V>> effect)
void	foreach(F<P2<K,V>,Unit> function)
static <K,V> HashMap<K,V>	from(java.lang.Iterable<P2<K,V>> entries)
static <K,V> HashMap<K,V>	from(java.lang.Iterable<P2<K,V>> entries, Equal<K> equal, Hash<K> hash)
F<K,Option<V>>	get() A curried version of get(Object).
Option<V>	get(K k) Returns a potential value that the given key maps to.
Option<V>	getDelete(K k) Deletes the entry in the hash map that corresponds to the given key and returns any associated value.
int	hash(K k) Compute the hash of the given key value using the underlying hashing strategy.
static <K,V> HashMap<K,V>	hashMap() Construct a hash map that uses Object.equals(java.lang.Object) and Object.hashCode().
boolean	isEmpty() Determines if this hash map has any entries.
java.util.Iterator<K>	iterator() Returns an iterator for this map's keys.
List<K>	keys() Returns all key entries in this hash map.
<A,B> HashMap<A,B>	map(F<K,A> keyFunction, F<V,B> valueFunction)
<A,B> HashMap<A,B>	map(F<K,A> keyFunction, F<V,B> valueFunction, Equal<A> equal, Hash<A> hash)
<A,B> HashMap<A,B>	map(F<P2<K,V>,P2<A,B>> function)
<A,B> HashMap<A,B>	map(F<P2<K,V>,P2<A,B>> function, Equal<A> equal, Hash<A> hash)
<A> HashMap<A,V>	mapKeys(F<K,A> function)
<A> HashMap<A,V>	mapKeys(F<K,A> keyFunction, Equal<A> equal, Hash<A> hash)
<B> HashMap<K,B>	mapValues(F<V,B> function)
void	set(K k, V v) Inserts the given key and value association into the hash map.
int	size() Returns the number of entries in this hash map.
Array<P2<K,V>>	toArray()
java.util.Collection<P2<K,V>>	toCollection() Projects an immutable collection of this hash map.
List<P2<K,V>>	toList()
java.util.Map<K,V>	toMap()
Option<P2<K,V>>	toOption()
Stream<P2<K,V>>	toStream()
List<V>	values() Returns all values in this hash map.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

HashMap

public HashMap(Equal<K> e,
       Hash<K> h)

Construct a hash map with the given equality and hashing strategy.

Parameters:

e - The equality strategy.

h - The hashing strategy.

HashMap

public HashMap(java.util.Map<K,V> map,
       Equal<K> e,
       Hash<K> h)

HashMap

public HashMap(Equal<K> e,
       Hash<K> h,
       int initialCapacity)

Construct a hash map with the given equality and hashing strategy.

Parameters:

e - The equality strategy.

h - The hashing strategy.

initialCapacity - The initial capacity.

HashMap

public HashMap(java.util.Map<K,V> map)

HashMap

public HashMap(Equal<K> e,
       Hash<K> h,
       int initialCapacity,
       float loadFactor)

Construct a hash map with the given equality and hashing strategy.

Parameters:

e - The equality strategy.

h - The hashing strategy.

initialCapacity - The initial capacity.

loadFactor - The load factor.

Method Detail

iterator

public java.util.Iterator<K> iterator()

Returns an iterator for this map's keys. This method exists to permit the use in a for-each loop.

Specified by:

iterator in interface java.lang.Iterable<K>

Returns:

A iterator for this map's keys.

hashMap

public static <K,V> HashMap<K,V> hashMap()

Construct a hash map that uses Object.equals(java.lang.Object) and Object.hashCode().

Returns:

A new hash map that uses Object.equals(java.lang.Object) and Object.hashCode().

eq

public boolean eq(K k1,
         K k2)

Compare two key values for equality using the underlying equality strategy.

Parameters:

k1 - One key value to compare.

k2 - The other key value to compare.

Returns:

true if the two key values are equal, false otherwise.

hash

public int hash(K k)

Compute the hash of the given key value using the underlying hashing strategy.

Parameters:

k - The key value to computer the hash of.

Returns:

The hash of the given key value.

get

public Option<V> get(K k)

Returns a potential value that the given key maps to.

Parameters:

k - The key to look up in the hash map.

Returns:

A potential value for the given key.

get

public F<K,Option<V>> get()

A curried version of get(Object).

Returns:

A curried version of get(Object).

clear

public void clear()

Clear all entries from this hash map.

contains

public boolean contains(K k)

Determines if the given key value exists in this hash map.

Parameters:

k - The key value to look for in this hash map.

Returns:

true if this hash map contains the given key, false otherwise.

keys

public List<K> keys()

Returns all key entries in this hash map.

Returns:

All key entries in this hash map.

values

public List<V> values()

Returns all values in this hash map.

Returns:

All values in this hash map.

isEmpty

public boolean isEmpty()

Determines if this hash map has any entries.

Returns:

true if this hash map has no entries, false otherwise.

size

public int size()

Returns the number of entries in this hash map.

Returns:

The number of entries in this hash map.

set

public void set(K k,
       V v)

Inserts the given key and value association into the hash map.

Parameters:

k - The key to insert.

v - The value to insert.

delete

public void delete(K k)

Deletes the entry in the hash map that corresponds to the given key.

Parameters:

k - The key to delete from this hash map.

getDelete

public Option<V> getDelete(K k)

Deletes the entry in the hash map that corresponds to the given key and returns any associated value.

Parameters:

k - The key to delete from this hash map.

Returns:

The value that was associated with the given key, if there was one.

map

public <A,B> HashMap<A,B> map(F<K,A> keyFunction,
                     F<V,B> valueFunction,
                     Equal<A> equal,
                     Hash<A> hash)

map

public <A,B> HashMap<A,B> map(F<K,A> keyFunction,
                     F<V,B> valueFunction)

map

public <A,B> HashMap<A,B> map(F<P2<K,V>,P2<A,B>> function,
                     Equal<A> equal,
                     Hash<A> hash)

map

public <A,B> HashMap<A,B> map(F<P2<K,V>,P2<A,B>> function)

mapKeys

public <A> HashMap<A,V> mapKeys(F<K,A> keyFunction,
                       Equal<A> equal,
                       Hash<A> hash)

mapKeys

public <A> HashMap<A,V> mapKeys(F<K,A> function)

mapValues

public <B> HashMap<K,B> mapValues(F<V,B> function)

foreach

public void foreach(Effect<P2<K,V>> effect)

foreach

public void foreach(F<P2<K,V>,Unit> function)

toList

public List<P2<K,V>> toList()

toCollection

public java.util.Collection<P2<K,V>> toCollection()

Projects an immutable collection of this hash map.

Returns:

An immutable collection of this hash map.

toStream

public Stream<P2<K,V>> toStream()

toOption

public Option<P2<K,V>> toOption()

toArray

public Array<P2<K,V>> toArray()

toMap

public java.util.Map<K,V> toMap()

from

public static <K,V> HashMap<K,V> from(java.lang.Iterable<P2<K,V>> entries)

from

public static <K,V> HashMap<K,V> from(java.lang.Iterable<P2<K,V>> entries,
                      Equal<K> equal,
                      Hash<K> hash)