Package it.unimi.dsi.fastutil.chars

Class CharOpenHashSet

java.lang.Object

java.util.AbstractCollection<java.lang.Character>

it.unimi.dsi.fastutil.chars.AbstractCharCollection

it.unimi.dsi.fastutil.chars.AbstractCharSet

it.unimi.dsi.fastutil.chars.CharOpenHashSet

All Implemented Interfaces:

CharCollection, CharIterable, CharSet, Hash, java.io.Serializable, java.lang.Cloneable, java.lang.Iterable<java.lang.Character>, java.util.Collection<java.lang.Character>, java.util.Set<java.lang.Character>

public class CharOpenHashSet
extends AbstractCharSet
implements java.io.Serializable, java.lang.Cloneable, Hash

A type-specific hash set with with a fast, small-footprint implementation.

Instances of this class use a hash table to represent a set. The table is filled up to a specified load factor, and then doubled in size to accommodate new entries. If the table is emptied below one fourth of the load factor, it is halved in size; however, the table is never reduced to a size smaller than that at creation time: this approach makes it possible to create sets with a large capacity in which insertions and deletions do not cause immediately rehashing. Moreover, halving is not performed when deleting entries from an iterator, as it would interfere with the iteration process.

Note that clear() does not modify the hash table size. Rather, a family of trimming methods lets you control the size of the table; this is particularly useful if you reuse instances of this class.

See Also:

Hash, HashCommon, Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.Hash

Hash.Strategy<K>

Field Summary

Fields inherited from interface it.unimi.dsi.fastutil.Hash

DEFAULT_GROWTH_FACTOR, DEFAULT_INITIAL_SIZE, DEFAULT_LOAD_FACTOR, FAST_LOAD_FACTOR, FREE, OCCUPIED, PRIMES, REMOVED, VERY_FAST_LOAD_FACTOR

Constructor Summary

Constructors

Constructor	Description
CharOpenHashSet()	Creates a new hash set with initial expected Hash.DEFAULT_INITIAL_SIZE elements and Hash.DEFAULT_LOAD_FACTOR as load factor.
CharOpenHashSet(char[] a)	Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor copying the elements of an array.
CharOpenHashSet(char[] a, float f)	Creates a new hash set copying the elements of an array.
CharOpenHashSet(char[] a, int offset, int length)	Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor and fills it with the elements of a given array.
CharOpenHashSet(char[] a, int offset, int length, float f)	Creates a new hash set and fills it with the elements of a given array.
CharOpenHashSet(int expected)	Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor.
CharOpenHashSet(int expected, float f)	Creates a new hash set.
CharOpenHashSet(CharCollection c)	Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific collection.
CharOpenHashSet(CharCollection c, float f)	Creates a new hash set copying a given type-specific collection.
CharOpenHashSet(CharIterator i)	Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor using elements provided by a type-specific iterator.
CharOpenHashSet(CharIterator i, float f)	Creates a new hash set using elements provided by a type-specific iterator.
CharOpenHashSet(java.util.Collection<? extends java.lang.Character> c)	Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given collection.
CharOpenHashSet(java.util.Collection<? extends java.lang.Character> c, float f)	Creates a new hash set copying a given collection.
CharOpenHashSet(java.util.Iterator<?> i)	Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor using elements provided by an iterator.
CharOpenHashSet(java.util.Iterator<?> i, float f)	Creates a new hash set using elements provided by an iterator.

Method Summary

Modifier and Type	Method	Description
boolean	add(char k)	Ensures that this collection contains the specified element (optional operation).
boolean	addAll(CharCollection c)	Adds all elements of the given type-specific collection to this collection.
boolean	addAll(java.util.Collection<? extends java.lang.Character> c)
void	clear()
CharOpenHashSet	clone()	Returns a deep copy of this set.
boolean	contains(char k)	Returns true if this collection contains the specified element.
void	forEach(CharConsumer action)	Performs the given action for each element of this type-specific Iterable until all elements have been processed or the action throws an exception.
int	hashCode()	Returns a hash code for this set.
boolean	isEmpty()
CharIterator	iterator()	Returns a type-specific iterator on the elements of this collection.
static CharOpenHashSet	of()	Creates a new empty hash set.
static CharOpenHashSet	of(char e)	Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor using the given element.
static CharOpenHashSet	of(char... a)	Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor using a list of elements.
static CharOpenHashSet	of(char e0, char e1)	Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor using the elements given.
static CharOpenHashSet	of(char e0, char e1, char e2)	Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor using the elements given.
boolean	remove(char k)	Removes an element from this set.
int	size()
CharSpliterator	spliterator()	Returns a type-specific spliterator on the elements of this set.
boolean	trim()	Rehashes this set, making the table as small as possible.
boolean	trim(int n)	Rehashes this set if the table is too large.

Methods inherited from class it.unimi.dsi.fastutil.chars.AbstractCharSet

equals, rem

Methods inherited from class it.unimi.dsi.fastutil.chars.AbstractCharCollection

add, contains, containsAll, containsAll, remove, removeAll, removeAll, retainAll, retainAll, toArray, toCharArray, toCharArray, toString

Methods inherited from class java.util.AbstractCollection

toArray, toArray

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface it.unimi.dsi.fastutil.chars.CharCollection

containsAll, intIterator, intParallelStream, intSpliterator, intStream, parallelStream, removeAll, removeIf, removeIf, removeIf, retainAll, stream, toArray, toCharArray, toCharArray

Methods inherited from interface it.unimi.dsi.fastutil.chars.CharIterable

forEach, forEach

Methods inherited from interface it.unimi.dsi.fastutil.chars.CharSet

add, contains, remove

Methods inherited from interface java.util.Collection

toArray

Methods inherited from interface java.util.Set

containsAll, removeAll, retainAll, toArray, toArray

Constructor Details

CharOpenHashSet

public CharOpenHashSet(int expected,
float f)

Creates a new hash set.

The actual table size will be the least power of two greater than expected/f.

Parameters:

expected - the expected number of elements in the hash set.

f - the load factor.

CharOpenHashSet

public CharOpenHashSet(int expected)

Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor.

Parameters:

expected - the expected number of elements in the hash set.

CharOpenHashSet

public CharOpenHashSet()

Creates a new hash set with initial expected Hash.DEFAULT_INITIAL_SIZE elements and Hash.DEFAULT_LOAD_FACTOR as load factor.

CharOpenHashSet

public CharOpenHashSet(java.util.Collection<? extends java.lang.Character> c,
float f)

Creates a new hash set copying a given collection.

Parameters:

c - a Collection to be copied into the new hash set.

f - the load factor.

CharOpenHashSet

public CharOpenHashSet(java.util.Collection<? extends java.lang.Character> c)

Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given collection.

Parameters:

c - a Collection to be copied into the new hash set.

CharOpenHashSet

public CharOpenHashSet(CharCollection c,
float f)

Creates a new hash set copying a given type-specific collection.

Parameters:

c - a type-specific collection to be copied into the new hash set.

f - the load factor.

CharOpenHashSet

public CharOpenHashSet(CharCollection c)

Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific collection.

Parameters:

c - a type-specific collection to be copied into the new hash set.

CharOpenHashSet

public CharOpenHashSet(CharIterator i,
float f)

Creates a new hash set using elements provided by a type-specific iterator.

Parameters:

i - a type-specific iterator whose elements will fill the set.

f - the load factor.

CharOpenHashSet

public CharOpenHashSet(CharIterator i)

Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor using elements provided by a type-specific iterator.

Parameters:

i - a type-specific iterator whose elements will fill the set.

CharOpenHashSet

public CharOpenHashSet(java.util.Iterator<?> i,
float f)

Creates a new hash set using elements provided by an iterator.

Parameters:

i - an iterator whose elements will fill the set.

f - the load factor.

CharOpenHashSet

public CharOpenHashSet(java.util.Iterator<?> i)

Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor using elements provided by an iterator.

Parameters:

i - an iterator whose elements will fill the set.

CharOpenHashSet

public CharOpenHashSet(char[] a,
int offset,
int length,
float f)

Creates a new hash set and fills it with the elements of a given array.

Parameters:

a - an array whose elements will be used to fill the set.

offset - the first element to use.

length - the number of elements to use.

f - the load factor.

CharOpenHashSet

public CharOpenHashSet(char[] a,
int offset,
int length)

Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor and fills it with the elements of a given array.

Parameters:

a - an array whose elements will be used to fill the set.

offset - the first element to use.

length - the number of elements to use.

CharOpenHashSet

public CharOpenHashSet(char[] a,
float f)

Creates a new hash set copying the elements of an array.

Parameters:

a - an array to be copied into the new hash set.

f - the load factor.

CharOpenHashSet

public CharOpenHashSet(char[] a)

Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor copying the elements of an array.

Parameters:

a - an array to be copied into the new hash set.

Method Details

of

public static CharOpenHashSet of()

Creates a new empty hash set.

Returns:

a new empty hash set.

of

public static CharOpenHashSet of(char e)

Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor using the given element.

Parameters:

e - the element that the returned set will contain.

Returns:

a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor containing e.

of

public static CharOpenHashSet of(char e0,
char e1)

Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor using the elements given.

Parameters:

e0 - the first element.

e1 - the second element.

Returns:

a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor containing e0 and e1.

Throws:

java.lang.IllegalArgumentException - if there were duplicate entries.

of

public static CharOpenHashSet of(char e0,
char e1,
char e2)

Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor using the elements given.

Parameters:

e0 - the first element.

e1 - the second element.

e2 - the third element.

Returns:

a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor containing e0, e1, and e2.

Throws:

java.lang.IllegalArgumentException - if there were duplicate entries.

of

public static CharOpenHashSet of(char... a)

Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor using a list of elements.

Parameters:

a - a list of elements that will be used to initialize the new hash set.

Returns:

a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor containing the elements of a.

Throws:

java.lang.IllegalArgumentException - if a duplicate entry was encountered.

addAll

public boolean addAll(CharCollection c)

Description copied from interface: CharCollection

Adds all elements of the given type-specific collection to this collection.

Specified by:

addAll in interface CharCollection

Overrides:

addAll in class AbstractCharCollection

Parameters:

c - a type-specific collection.

Returns:

true if this collection changed as a result of the call.

See Also:

Collection.addAll(Collection)

addAll

public boolean addAll(java.util.Collection<? extends java.lang.Character> c)

Description copied from class: AbstractCharCollection

Specified by:

addAll in interface java.util.Collection<java.lang.Character>

Specified by:

addAll in interface java.util.Set<java.lang.Character>

Overrides:

addAll in class AbstractCharCollection

add

public boolean add(char k)

Description copied from class: AbstractCharCollection

Ensures that this collection contains the specified element (optional operation).

Specified by:

add in interface CharCollection

Overrides:

add in class AbstractCharCollection

See Also:

Collection.add(Object)

remove

public boolean remove(char k)

Description copied from class: AbstractCharSet

Removes an element from this set. Delegates to the type-specific rem() method implemented by type-specific abstract Collection superclass.

Specified by:

remove in interface CharSet

Overrides:

remove in class AbstractCharSet

See Also:

Collection.remove(Object)

contains

public boolean contains(char k)

Description copied from class: AbstractCharCollection

Returns true if this collection contains the specified element.

Specified by:

contains in interface CharCollection

Overrides:

contains in class AbstractCharCollection

See Also:

Collection.contains(Object)

clear

public void clear()

Specified by:

clear in interface java.util.Collection<java.lang.Character>

Specified by:

clear in interface java.util.Set<java.lang.Character>

Overrides:

clear in class java.util.AbstractCollection<java.lang.Character>

size

public int size()

Specified by:

size in interface java.util.Collection<java.lang.Character>

Specified by:

size in interface java.util.Set<java.lang.Character>

Specified by:

size in class java.util.AbstractCollection<java.lang.Character>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface java.util.Collection<java.lang.Character>

Specified by:

isEmpty in interface java.util.Set<java.lang.Character>

Overrides:

isEmpty in class java.util.AbstractCollection<java.lang.Character>

iterator

public CharIterator iterator()

Description copied from interface: CharCollection

Returns a type-specific iterator on the elements of this collection.

Specified by:

iterator in interface CharCollection

Specified by:

iterator in interface CharIterable

Specified by:

iterator in interface CharSet

Specified by:

iterator in interface java.util.Collection<java.lang.Character>

Specified by:

iterator in interface java.lang.Iterable<java.lang.Character>

Specified by:

iterator in interface java.util.Set<java.lang.Character>

Specified by:

iterator in class AbstractCharSet

Returns:

a type-specific iterator on the elements of this collection.

See Also:

Iterable.iterator()

spliterator

public CharSpliterator spliterator()

Description copied from interface: CharSet

Returns a type-specific spliterator on the elements of this set.

Set spliterators must report at least Spliterator.DISTINCT.

See Set.spliterator() for more documentation on the requirements of the returned spliterator.

Specified by:

spliterator in interface CharCollection

Specified by:

spliterator in interface CharIterable

Specified by:

spliterator in interface CharSet

Specified by:

spliterator in interface java.util.Collection<java.lang.Character>

Specified by:

spliterator in interface java.lang.Iterable<java.lang.Character>

Specified by:

spliterator in interface java.util.Set<java.lang.Character>

Returns:

a type-specific spliterator on the elements of this collection.

forEach

public void forEach(CharConsumer action)

Description copied from interface: CharIterable

Performs the given action for each element of this type-specific Iterable until all elements have been processed or the action throws an exception.

Specified by:

forEach in interface CharIterable

Parameters:

action - the action to be performed for each element.

See Also:

Iterable.forEach(java.util.function.Consumer)

trim

public boolean trim()

Rehashes this set, making the table as small as possible.

This method rehashes the table to the smallest size satisfying the load factor. It can be used when the set will not be changed anymore, so to optimize access speed and size.

If the table size is already the minimum possible, this method does nothing.

Returns:

true if there was enough memory to trim the set.

See Also:

trim(int)

trim

public boolean trim(int n)

Rehashes this set if the table is too large.

Let N be the smallest table size that can hold max(n,size()) entries, still satisfying the load factor. If the current table size is smaller than or equal to N, this method does nothing. Otherwise, it rehashes this set in a table of size N.

This method is useful when reusing sets. Clearing a set leaves the table size untouched. If you are reusing a set many times, you can call this method with a typical size to avoid keeping around a very large table just because of a few large transient sets.

Parameters:

n - the threshold for the trimming.

Returns:

true if there was enough memory to trim the set.

See Also:

trim()

clone

public CharOpenHashSet clone()

Returns a deep copy of this set.

This method performs a deep copy of this hash set; the data stored in the set, however, is not cloned. Note that this makes a difference only for object keys.

Returns:

a deep copy of this set.

hashCode

public int hashCode()

Returns a hash code for this set. This method overrides the generic method provided by the superclass. Since equals() is not overriden, it is important that the value returned by this method is the same value as the one returned by the overriden method.

Specified by:

hashCode in interface java.util.Collection<java.lang.Character>

Specified by:

hashCode in interface java.util.Set<java.lang.Character>

Overrides:

hashCode in class AbstractCharSet

Returns:

a hash code for this set.