Package org.apache.lucene.analysis

Class CharArraySet

java.lang.Object

java.util.AbstractCollection<Object>

java.util.AbstractSet<Object>

org.apache.lucene.analysis.CharArraySet

All Implemented Interfaces:

Iterable<Object>, Collection<Object>, Set<Object>

public class CharArraySet
extends AbstractSet<Object>

A simple class that stores Strings as char[]'s in a hash table. Note that this is not a general purpose class. For example, it cannot remove items from the set, nor does it resize its hash table to be smaller, etc. It is designed to be quick to test if a char[] is in the set without the necessity of converting it to a String first.

Please note: This class implements Set but does not behave like it should in all cases. The generic type is Set<Object>, because you can add any object to it, that has a string representation. The add methods will use Object.toString() and store the result using a char[] buffer. The same behavior have the contains() methods. The iterator() returns an Iterator<char[]>.

Field Summary

Fields

Modifier and Type	Field	Description
static final CharArraySet	EMPTY_SET	An empty CharArraySet.
private final CharArrayMap<Object>	map
private static final Object	PLACEHOLDER

Constructor Summary

Constructors

Constructor	Description
CharArraySet(int startSize, boolean ignoreCase)	Create set with enough capacity to hold startSize terms
CharArraySet(Collection<?> c, boolean ignoreCase)	Creates a set from a Collection of objects.
CharArraySet(CharArrayMap<Object> map)	Create set from the specified map (internal only), used also by CharArrayMap.keySet()

Method Summary

Modifier and Type	Method	Description
boolean	add(char[] text)	Add this char[] directly to the set.
boolean	add(CharSequence text)	Add this CharSequence into the set
boolean	add(Object o)
boolean	add(String text)	Add this String into the set
void	clear()	Clears all entries in this set.
boolean	contains(char[] text, int off, int len)	true if the len chars of text starting at off are in the set
boolean	contains(CharSequence cs)	true if the CharSequence is in the set
boolean	contains(Object o)
static CharArraySet	copy(Set<?> set)	Returns a copy of the given set as a CharArraySet.
Iterator<Object>	iterator()	Returns an Iterator for char[] instances in this set.
int	size()
String	toString()
static CharArraySet	unmodifiableSet(CharArraySet set)	Returns an unmodifiable CharArraySet.

Methods inherited from class java.util.AbstractSet

equals, hashCode, removeAll

Methods inherited from class java.util.AbstractCollection

addAll, containsAll, isEmpty, remove, retainAll, toArray, toArray

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable

forEach

Methods inherited from interface java.util.Set

addAll, containsAll, isEmpty, remove, retainAll, spliterator, toArray, toArray

Field Details

EMPTY_SET

public static final CharArraySet EMPTY_SET

An empty CharArraySet.

PLACEHOLDER

private static final Object PLACEHOLDER

map

private final CharArrayMap<Object> map

Constructor Details

CharArraySet

public CharArraySet(int startSize,
 boolean ignoreCase)

Create set with enough capacity to hold startSize terms

Parameters:

startSize - the initial capacity

ignoreCase - false if and only if the set should be case sensitive otherwise true.

CharArraySet

public CharArraySet(Collection<?> c,
 boolean ignoreCase)

Creates a set from a Collection of objects.

Parameters:

c - a collection whose elements to be placed into the set

ignoreCase - false if and only if the set should be case sensitive otherwise true.

CharArraySet

CharArraySet(CharArrayMap<Object> map)

Create set from the specified map (internal only), used also by CharArrayMap.keySet()

Method Details

clear

public void clear()

Clears all entries in this set. This method is supported for reusing, but not Set.remove(java.lang.Object).

Specified by:

clear in interface Collection<Object>

Specified by:

clear in interface Set<Object>

Overrides:

clear in class AbstractCollection<Object>

contains

public boolean contains(char[] text,
 int off,
 int len)

true if the len chars of text starting at off are in the set

contains

public boolean contains(CharSequence cs)

true if the CharSequence is in the set

contains

public boolean contains(Object o)

Specified by:

contains in interface Collection<Object>

Specified by:

contains in interface Set<Object>

Overrides:

contains in class AbstractCollection<Object>

add

public boolean add(Object o)

Specified by:

add in interface Collection<Object>

Specified by:

add in interface Set<Object>

Overrides:

add in class AbstractCollection<Object>

add

public boolean add(CharSequence text)

Add this CharSequence into the set

add

public boolean add(String text)

Add this String into the set

add

public boolean add(char[] text)

Add this char[] directly to the set. If ignoreCase is true for this Set, the text array will be directly modified. The user should never modify this text array after calling this method.

size

public int size()

Specified by:

size in interface Collection<Object>

Specified by:

size in interface Set<Object>

Specified by:

size in class AbstractCollection<Object>

unmodifiableSet

public static CharArraySet unmodifiableSet(CharArraySet set)

Returns an unmodifiable CharArraySet. This allows to provide unmodifiable views of internal sets for "read-only" use.

Parameters:

set - a set for which the unmodifiable set is returned.

Returns:

an new unmodifiable CharArraySet.

Throws:

NullPointerException - if the given set is null.

copy

public static CharArraySet copy(Set<?> set)

Returns a copy of the given set as a CharArraySet. If the given set is a CharArraySet the ignoreCase property will be preserved.

Parameters:

set - a set to copy

Returns:

a copy of the given set as a CharArraySet. If the given set is a CharArraySet the ignoreCase property as well as the matchVersion will be of the given set will be preserved.

iterator

public Iterator<Object> iterator()

Returns an Iterator for char[] instances in this set.

Specified by:

iterator in interface Collection<Object>

Specified by:

iterator in interface Iterable<Object>

Specified by:

iterator in interface Set<Object>

Specified by:

iterator in class AbstractCollection<Object>

toString

public String toString()

Overrides:

toString in class AbstractCollection<Object>