public class BitSetFX extends AbstractSet<Integer> implements SortedSet<Integer>, Cloneable, Serializable
boolean
value. The bits of a BitSet
are indexed by nonnegative integers. Individual indexed bits can be examined,
set, or cleared. One BitSet
may be used to modify the contents of another BitSet
through logical AND,
logical inclusive OR, and logical exclusive OR operations.
By default, all bits in the set initially have the value false
.
Every bit set has a current size, which is the number of bits of space currently in use by the bit set. Note that the size is related to the implementation of a bit set, so it may change with implementation. The length of a bit set relates to logical length of a bit set and is defined independently of implementation.
Unless otherwise noted, passing a null parameter to any of the methods in a BitSet
will result in a
NullPointerException
.
A BitSet
is not safe for multithreaded use without external synchronization.
Constructor and Description |
---|
BitSetFX()
Creates a new bit set.
|
BitSetFX(BitSetFX b) |
BitSetFX(Collection<? extends Integer> c) |
BitSetFX(int nbits)
Creates a bit set whose initial size is large enough to explicitly represent bits with indices in the range
0 through nbits-1 . |
Modifier and Type | Method and Description |
---|---|
boolean |
add(Integer e) |
boolean |
addAll(Collection<? extends Integer> c) |
void |
addRange(int start,
int end) |
void |
and(BitSetFX... sets) |
void |
and(BitSetFX set)
Performs a logical AND of this target bit set with the argument bit set.
|
void |
and(Collection<BitSetFX> sets) |
void |
andNot(BitSetFX set)
Clears all of the bits in this
BitSet whose corresponding bit is set in the specified BitSet . |
int |
cardinality()
Returns the number of bits set to
true in this BitSet . |
void |
clear()
Sets all of the bits in this BitSet to
false . |
void |
clear(int bitIndex)
Sets the bit specified by the index to
false . |
void |
clear(int fromIndex,
int toIndex)
Sets the bits from the specified
fromIndex (inclusive) to the specified toIndex (exclusive) to
false . |
Object |
clone()
Cloning this
BitSet produces a new BitSet that is equal to it. |
Comparator<? super Integer> |
comparator() |
boolean |
contains(Object o) |
boolean |
containsAll(Collection<?> c) |
boolean |
equals(Object obj)
Compares this object against the specified object.
|
Integer |
first() |
void |
flip(int bitIndex)
Sets the bit at the specified index to the complement of its current value.
|
void |
flip(int fromIndex,
int toIndex)
Sets each bit from the specified
fromIndex (inclusive) to the specified toIndex (exclusive) to the
complement of its current value. |
boolean |
geq(BitSetFX set) |
boolean |
get(int bitIndex)
Returns the value of the bit with the specified index.
|
BitSetFX |
get(int fromIndex,
int toIndex)
Returns a new
BitSet composed of bits from this BitSet from fromIndex (inclusive) to
toIndex (exclusive). |
int |
hashCode()
Returns the hash code value for this bit set.
|
SortedSet<Integer> |
headSet(Integer toElement) |
boolean |
intersects(BitSetFX set)
Returns true if the specified
BitSet has any bits set to true that are also set to true in
this BitSet . |
boolean |
isEmpty()
Returns true if this
BitSet contains no bits that are set to true . |
Iterator<Integer> |
iterator() |
Integer |
last() |
int |
length()
Returns the "logical size" of this
BitSet : the index of the highest set bit in the BitSet plus one. |
int |
nextClearBit(int fromIndex)
Returns the index of the first bit that is set to
false that occurs on or after the specified starting
index. |
int |
nextSetBit(int fromIndex)
Returns the index of the first bit that is set to
true that occurs on or after the specified starting
index. |
void |
or(BitSetFX set)
Performs a logical OR of this bit set with the bit set argument.
|
int |
previousClearBit(int fromIndex)
Returns the index of the nearest bit that is set to
false that occurs on or before the specified starting
index. |
int |
previousSetBit(int fromIndex)
Returns the index of the nearest bit that is set to
true that occurs on or before the specified starting
index. |
boolean |
remove(Object o) |
boolean |
removeAll(Collection<?> c) |
boolean |
retainAll(Collection<?> c) |
void |
set(int bitIndex)
Sets the bit at the specified index to
true . |
void |
set(int bitIndex,
boolean value)
Sets the bit at the specified index to the specified value.
|
void |
set(int fromIndex,
int toIndex)
Sets the bits from the specified
fromIndex (inclusive) to the specified toIndex (exclusive) to
true . |
void |
set(int fromIndex,
int toIndex,
boolean value)
Sets the bits from the specified
fromIndex (inclusive) to the specified toIndex (exclusive) to the
specified value. |
int |
size() |
int |
space()
Returns the number of bits of space actually in use by this
BitSet to represent bit values. |
Stream<Integer> |
stream()
Returns a stream of indices for which this
BitSet contains a bit in the set state. |
SortedSet<Integer> |
subSet(Integer fromElement,
Integer toElement) |
SortedSet<Integer> |
tailSet(Integer fromElement) |
byte[] |
toByteArray()
Returns a new byte array containing all the bits in this bit set.
|
long[] |
toLongArray()
Returns a new long array containing all the bits in this bit set.
|
String |
toString()
Returns a string representation of this bit set.
|
static BitSetFX |
valueOf(byte[] bytes)
Returns a new bit set containing all the bits in the given byte array.
|
static BitSetFX |
valueOf(ByteBuffer bb)
Returns a new bit set containing all the bits in the given byte buffer between its position and limit.
|
static BitSetFX |
valueOf(long[] longs)
Returns a new bit set containing all the bits in the given long array.
|
static BitSetFX |
valueOf(LongBuffer lb)
Returns a new bit set containing all the bits in the given long buffer between its position and limit.
|
void |
xor(BitSetFX set)
Performs a logical XOR of this bit set with the bit set argument.
|
toArray, toArray
finalize, getClass, notify, notifyAll, wait, wait, wait
spliterator
parallelStream, removeIf
public BitSetFX()
false
.public BitSetFX(int nbits)
0
through nbits-1
. All bits are initially false
.nbits
- the initial size of the bit setNegativeArraySizeException
- if the specified initial size is negativepublic BitSetFX(Collection<? extends Integer> c)
public static BitSetFX valueOf(long[] longs)
More precisely,
BitSet.valueOf(longs).get(n) == ((longs[n/64] & (1L<<(n%64))) != 0)
for all n < 64 * longs.length
.
This method is equivalent to BitSet.valueOf(LongBuffer.wrap(longs))
.
longs
- a long array containing a little-endian representation of a sequence of bits to be used as the initial
bits of the new bit setBitSet
containing all the bits in the long arraypublic static BitSetFX valueOf(LongBuffer lb)
More precisely,
BitSet.valueOf(lb).get(n) == ((lb.get(lb.position()+n/64) & (1L<<(n%64))) != 0)
for all n < 64 * lb.remaining()
.
The long buffer is not modified by this method, and no reference to the buffer is retained by the bit set.
lb
- a long buffer containing a little-endian representation of a sequence of bits between its position and
limit, to be used as the initial bits of the new bit setBitSet
containing all the bits in the buffer in the specified rangepublic static BitSetFX valueOf(byte[] bytes)
More precisely,
BitSet.valueOf(bytes).get(n) == ((bytes[n/8] & (1<<(n%8))) != 0)
for all n < 8 * bytes.length
.
This method is equivalent to BitSet.valueOf(ByteBuffer.wrap(bytes))
.
bytes
- a byte array containing a little-endian representation of a sequence of bits to be used as the initial
bits of the new bit setBitSet
containing all the bits in the byte arraypublic static BitSetFX valueOf(ByteBuffer bb)
More precisely,
BitSet.valueOf(bb).get(n) == ((bb.get(bb.position()+n/8) & (1<<(n%8))) != 0)
for all n < 8 * bb.remaining()
.
The byte buffer is not modified by this method, and no reference to the buffer is retained by the bit set.
bb
- a byte buffer containing a little-endian representation of a sequence of bits between its position and
limit, to be used as the initial bits of the new bit setBitSet
containing all the bits in the buffer in the specified rangepublic byte[] toByteArray()
More precisely, if
byte[] bytes = s.toByteArray();
then bytes.length == (s.length()+7)/8
and
s.get(n) == ((bytes[n/8] & (1<<(n%8))) != 0)
for all n < 8 * bytes.length
.
public long[] toLongArray()
More precisely, if
long[] longs = s.toLongArray();
then longs.length == (s.length()+63)/64
and
s.get(n) == ((longs[n/64] & (1L<<(n%64))) != 0)
for all n < 64 * longs.length
.
public void flip(int bitIndex)
bitIndex
- the index of the bit to flipIndexOutOfBoundsException
- if the specified index is negativepublic void flip(int fromIndex, int toIndex)
fromIndex
(inclusive) to the specified toIndex
(exclusive) to the
complement of its current value.fromIndex
- index of the first bit to fliptoIndex
- index after the last bit to flipIndexOutOfBoundsException
- if fromIndex
is negative, or toIndex
is negative, or fromIndex
is larger than
toIndex
public void set(int bitIndex)
true
.bitIndex
- a bit indexIndexOutOfBoundsException
- if the specified index is negativepublic void set(int bitIndex, boolean value)
bitIndex
- a bit indexvalue
- a boolean value to setIndexOutOfBoundsException
- if the specified index is negativepublic void set(int fromIndex, int toIndex)
fromIndex
(inclusive) to the specified toIndex
(exclusive) to
true
.fromIndex
- index of the first bit to be settoIndex
- index after the last bit to be setIndexOutOfBoundsException
- if fromIndex
is negative, or toIndex
is negative, or fromIndex
is larger than
toIndex
public void set(int fromIndex, int toIndex, boolean value)
fromIndex
(inclusive) to the specified toIndex
(exclusive) to the
specified value.fromIndex
- index of the first bit to be settoIndex
- index after the last bit to be setvalue
- value to set the selected bits toIndexOutOfBoundsException
- if fromIndex
is negative, or toIndex
is negative, or fromIndex
is larger than
toIndex
public void clear(int bitIndex)
false
.bitIndex
- the index of the bit to be clearedIndexOutOfBoundsException
- if the specified index is negativepublic void clear(int fromIndex, int toIndex)
fromIndex
(inclusive) to the specified toIndex
(exclusive) to
false
.fromIndex
- index of the first bit to be clearedtoIndex
- index after the last bit to be clearedIndexOutOfBoundsException
- if fromIndex
is negative, or toIndex
is negative, or fromIndex
is larger than
toIndex
public void clear()
false
.clear
in interface Collection<Integer>
clear
in interface Set<Integer>
clear
in class AbstractCollection<Integer>
public boolean get(int bitIndex)
true
if the bit with the index
bitIndex
is currently set in this BitSet
; otherwise, the result is false
.bitIndex
- the bit indexIndexOutOfBoundsException
- if the specified index is negativepublic BitSetFX get(int fromIndex, int toIndex)
BitSet
composed of bits from this BitSet
from fromIndex
(inclusive) to
toIndex
(exclusive).fromIndex
- index of the first bit to includetoIndex
- index after the last bit to includeBitSet
from a range of this BitSet
IndexOutOfBoundsException
- if fromIndex
is negative, or toIndex
is negative, or fromIndex
is larger than
toIndex
public int nextSetBit(int fromIndex)
true
that occurs on or after the specified starting
index. If no such bit exists then -1
is returned.
To iterate over the true
bits in a BitSet
, use the following loop:
for (int i = bs.nextSetBit(0); i >= 0; i = bs.nextSetBit(i+1)) {
// operate on index i here
if (i == Integer.MAX_VALUE) {
break; // or (i+1) would overflow
}
}
fromIndex
- the index to start checking from (inclusive)-1
if there is no such bitIndexOutOfBoundsException
- if the specified index is negativepublic int nextClearBit(int fromIndex)
false
that occurs on or after the specified starting
index.fromIndex
- the index to start checking from (inclusive)IndexOutOfBoundsException
- if the specified index is negativepublic int previousSetBit(int fromIndex)
true
that occurs on or before the specified starting
index. If no such bit exists, or if -1
is given as the starting index, then -1
is returned.
To iterate over the true
bits in a BitSet
, use the following loop:
for (int i = bs.length(); (i = bs.previousSetBit(i-1)) >= 0; ) {
// operate on index i here
}
fromIndex
- the index to start checking from (inclusive)-1
if there is no such bitIndexOutOfBoundsException
- if the specified index is less than -1
public int previousClearBit(int fromIndex)
false
that occurs on or before the specified starting
index. If no such bit exists, or if -1
is given as the starting index, then -1
is returned.fromIndex
- the index to start checking from (inclusive)-1
if there is no such bitIndexOutOfBoundsException
- if the specified index is less than -1
public int length()
BitSet
: the index of the highest set bit in the BitSet
plus one.
Returns zero if the BitSet
contains no set bits.BitSet
public boolean isEmpty()
BitSet
contains no bits that are set to true
.isEmpty
in interface Collection<Integer>
isEmpty
in interface Set<Integer>
isEmpty
in class AbstractCollection<Integer>
BitSet
is emptypublic boolean intersects(BitSetFX set)
BitSet
has any bits set to true
that are also set to true
in
this BitSet
.set
- BitSet
to intersect withBitSet
intersects the specified BitSet
public int cardinality()
true
in this BitSet
.true
in this BitSet
public void and(BitSetFX set)
true
if and only if it both initially had the value true
and the
corresponding bit in the bit set argument also had the value true
.set
- a bit setpublic void or(BitSetFX set)
true
if and only if it either already had the value true
or the corresponding bit
in the bit set argument has the value true
.set
- a bit setpublic void xor(BitSetFX set)
true
if and only if one of the following statements holds:
true
, and the corresponding bit in the argument has the value
false
.
false
, and the corresponding bit in the argument has the value
true
.
set
- a bit setpublic void andNot(BitSetFX set)
BitSet
whose corresponding bit is set in the specified BitSet
.set
- the BitSet
with which to mask this BitSet
public int hashCode()
BitSet
.
The hash code is defined to be the result of the following calculation:
public int hashCode() {
long h = 1234;
long[] words = toLongArray();
for (int i = words.length; --i >= 0; )
h ^= words[i] * (i + 1);
return (int)((h >> 32) ^ h);
}
Note that the hash code changes if the set of bits is altered.hashCode
in interface Collection<Integer>
hashCode
in interface Set<Integer>
hashCode
in class AbstractSet<Integer>
public int space()
BitSet
to represent bit values. The maximum
element in the set is the size - 1st element.public int size()
size
in interface Collection<Integer>
size
in interface Set<Integer>
size
in class AbstractCollection<Integer>
public boolean equals(Object obj)
true
if and only if the argument is not
null
and is a Bitset
object that has exactly the same set of bits set to true
as this bit
set. That is, for every nonnegative int
index k
,
((BitSet) obj).get(k) == this.get(k)must be true. The current sizes of the two bit sets are not compared.
equals
in interface Collection<Integer>
equals
in interface Set<Integer>
equals
in class AbstractSet<Integer>
obj
- the object to compare withtrue
if the objects are the same; false
otherwisespace()
public Object clone()
BitSet
produces a new BitSet
that is equal to it. The clone of the bit set is another
bit set that has exactly the same bits set to true
as this bit set.public String toString()
BitSet
contains a bit in
the set state, the decimal representation of that index is included in the result. Such indices are listed in order
from lowest to highest, separated by ", " (a comma and a space) and surrounded by braces, resulting in the
usual mathematical notation for a set of integers.
Example:
BitSet drPepper = new BitSet();Now
drPepper.toString()
returns "{}
".
drPepper.set(2);Now
drPepper.toString()
returns "{2}
".
drPepper.set(4); drPepper.set(10);Now
drPepper.toString()
returns "{2, 4, 10}
".toString
in class AbstractCollection<Integer>
public Stream<Integer> stream()
BitSet
contains a bit in the set state. The indices are returned
in order, from lowest to highest. The size of the stream is the number of bits in the set state, equal to the value
returned by the cardinality()
method.
The bit set must remain constant during the execution of the terminal stream operation. Otherwise, the result of the terminal stream operation is undefined.
stream
in interface Collection<Integer>
public void and(Collection<BitSetFX> sets)
public boolean contains(Object o)
contains
in interface Collection<Integer>
contains
in interface Set<Integer>
contains
in class AbstractCollection<Integer>
public boolean containsAll(Collection<?> c)
containsAll
in interface Collection<Integer>
containsAll
in interface Set<Integer>
containsAll
in class AbstractCollection<Integer>
public boolean add(Integer e)
add
in interface Collection<Integer>
add
in interface Set<Integer>
add
in class AbstractCollection<Integer>
public boolean addAll(Collection<? extends Integer> c)
addAll
in interface Collection<Integer>
addAll
in interface Set<Integer>
addAll
in class AbstractCollection<Integer>
public void addRange(int start, int end)
public boolean remove(Object o)
remove
in interface Collection<Integer>
remove
in interface Set<Integer>
remove
in class AbstractCollection<Integer>
public boolean removeAll(Collection<?> c)
removeAll
in interface Collection<Integer>
removeAll
in interface Set<Integer>
removeAll
in class AbstractSet<Integer>
public boolean retainAll(Collection<?> c)
retainAll
in interface Collection<Integer>
retainAll
in interface Set<Integer>
retainAll
in class AbstractCollection<Integer>
public Comparator<? super Integer> comparator()
comparator
in interface SortedSet<Integer>
Copyright © 2010–2023 Francesco Kriegel. All rights reserved.