BitSet
open class BitSet : Cloneable, Serializable
kotlin.Any | |
↳ | java.util.BitSet |
This class implements a vector of bits that grows as needed. Each component of the bit set has a 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.
Summary
Public constructors | |
---|---|
BitSet() Creates a new bit set. |
|
Creates a bit set whose initial size is large enough to explicitly represent bits with indices in the range |
Public methods | |
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open Unit |
Performs a logical AND of this target bit set with the argument bit set. |
open Unit |
Clears all of the bits in this |
open Int |
Returns the number of bits set to |
open Unit |
Sets the bit specified by the index to |
open Unit |
Sets the bits from the specified |
open Unit |
clear() Sets all of the bits in this BitSet to |
open Any |
clone() Cloning this |
open Boolean |
Compares this object against the specified object. |
open Unit |
Sets the bit at the specified index to the complement of its current value. |
open Unit |
Sets each bit from the specified |
open Boolean |
Returns the value of the bit with the specified index. |
open BitSet! |
Returns a new |
open Int |
hashCode() Returns the hash code value for this bit set. |
open Boolean |
intersects(set: BitSet!) Returns true if the specified |
open Boolean |
isEmpty() Returns true if this |
open Int |
length() Returns the "logical size" of this |
open Int |
nextClearBit(fromIndex: Int) Returns the index of the first bit that is set to |
open Int |
nextSetBit(fromIndex: Int) Returns the index of the first bit that is set to |
open Unit |
Performs a logical OR of this bit set with the bit set argument. |
open Int |
previousClearBit(fromIndex: Int) Returns the index of the nearest bit that is set to |
open Int |
previousSetBit(fromIndex: Int) Returns the index of the nearest bit that is set to |
open Unit |
Sets the bit at the specified index to |
open Unit |
Sets the bit at the specified index to the specified value. |
open Unit |
Sets the bits from the specified |
open Unit |
Sets the bits from the specified |
open Int |
size() Returns the number of bits of space actually in use by this |
open IntStream! |
stream() Returns a stream of indices for which this |
open ByteArray! |
Returns a new byte array containing all the bits in this bit set. |
open LongArray! |
Returns a new long array containing all the bits in this bit set. |
open String |
toString() Returns a string representation of this bit set. |
open static BitSet! |
Returns a new bit set containing all the bits in the given long array. |
open static BitSet! |
valueOf(lb: LongBuffer!) Returns a new bit set containing all the bits in the given long buffer between its position and limit. |
open static BitSet! |
Returns a new bit set containing all the bits in the given byte array. |
open static BitSet! |
valueOf(bb: ByteBuffer!) Returns a new bit set containing all the bits in the given byte buffer between its position and limit. |
open Unit |
Performs a logical XOR of this bit set with the bit set argument. |
Public constructors
BitSet
BitSet(nbits: Int)
Creates a bit set whose initial size is large enough to explicitly represent bits with indices in the range 0
through nbits-1
. All bits are initially false
.
Parameters | |
---|---|
nbits |
Int: the initial size of the bit set |
Exceptions | |
---|---|
java.lang.NegativeArraySizeException |
if the specified initial size is negative |
Public methods
and
open fun and(set: BitSet!): Unit
Performs a logical AND of this target bit set with the argument bit set. This bit set is modified so that each bit in it has the value 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
.
Parameters | |
---|---|
set |
BitSet!: a bit set |
andNot
open fun andNot(set: BitSet!): Unit
Clears all of the bits in this BitSet
whose corresponding bit is set in the specified BitSet
.
Parameters | |
---|---|
set |
BitSet!: the BitSet with which to mask this BitSet |
cardinality
open fun cardinality(): Int
Returns the number of bits set to true
in this BitSet
.
Return | |
---|---|
Int |
the number of bits set to true in this BitSet |
clear
open fun clear(bitIndex: Int): Unit
Sets the bit specified by the index to false
.
Parameters | |
---|---|
bitIndex |
Int: the index of the bit to be cleared |
Exceptions | |
---|---|
java.lang.IndexOutOfBoundsException |
if the specified index is negative |
clear
open fun clear(
fromIndex: Int,
toIndex: Int
): Unit
Sets the bits from the specified fromIndex
(inclusive) to the specified toIndex
(exclusive) to false
.
Parameters | |
---|---|
fromIndex |
Int: index of the first bit to be cleared |
toIndex |
Int: index after the last bit to be cleared |
Exceptions | |
---|---|
java.lang.IndexOutOfBoundsException |
if fromIndex is negative, or toIndex is negative, or fromIndex is larger than toIndex |
clone
open fun clone(): Any
Cloning this 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.
Return | |
---|---|
Any |
a clone of this bit set |
Exceptions | |
---|---|
java.lang.CloneNotSupportedException |
if the object's class does not support the Cloneable interface. Subclasses that override the clone method can also throw this exception to indicate that an instance cannot be cloned. |
See Also
equals
open fun equals(other: Any?): Boolean
Compares this object against the specified object. The result is 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)
Parameters | |
---|---|
obj |
the object to compare with |
Return | |
---|---|
Boolean |
true if the objects are the same; false otherwise |
See Also
flip
open fun flip(bitIndex: Int): Unit
Sets the bit at the specified index to the complement of its current value.
Parameters | |
---|---|
bitIndex |
Int: the index of the bit to flip |
Exceptions | |
---|---|
java.lang.IndexOutOfBoundsException |
if the specified index is negative |
flip
open fun flip(
fromIndex: Int,
toIndex: Int
): Unit
Sets each bit from the specified fromIndex
(inclusive) to the specified toIndex
(exclusive) to the complement of its current value.
Parameters | |
---|---|
fromIndex |
Int: index of the first bit to flip |
toIndex |
Int: index after the last bit to flip |
Exceptions | |
---|---|
java.lang.IndexOutOfBoundsException |
if fromIndex is negative, or toIndex is negative, or fromIndex is larger than toIndex |
get
open fun get(bitIndex: Int): Boolean
Returns the value of the bit with the specified index. The value is true
if the bit with the index bitIndex
is currently set in this BitSet
; otherwise, the result is false
.
Parameters | |
---|---|
bitIndex |
Int: the bit index |
Return | |
---|---|
Boolean |
the value of the bit with the specified index |
Exceptions | |
---|---|
java.lang.IndexOutOfBoundsException |
if the specified index is negative |
get
open fun get(
fromIndex: Int,
toIndex: Int
): BitSet!
Returns a new BitSet
composed of bits from this BitSet
from fromIndex
(inclusive) to toIndex
(exclusive).
Parameters | |
---|---|
fromIndex |
Int: index of the first bit to include |
toIndex |
Int: index after the last bit to include |
Return | |
---|---|
BitSet! |
a new BitSet from a range of this BitSet |
Exceptions | |
---|---|
java.lang.IndexOutOfBoundsException |
if fromIndex is negative, or toIndex is negative, or fromIndex is larger than toIndex |
hashCode
open fun hashCode(): Int
Returns the hash code value for this bit set. The hash code depends only on which bits are set within this BitSet
.
The hash code is defined to be the result of the following calculation:
<code>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); }</code>
Return | |
---|---|
Int |
the hash code value for this bit set |
intersects
open fun intersects(set: BitSet!): Boolean
Returns true if the specified BitSet
has any bits set to true
that are also set to true
in this BitSet
.
Parameters | |
---|---|
set |
BitSet!: BitSet to intersect with |
Return | |
---|---|
Boolean |
boolean indicating whether this BitSet intersects the specified BitSet |
isEmpty
open fun isEmpty(): Boolean
Returns true if this BitSet
contains no bits that are set to true
.
Return | |
---|---|
Boolean |
boolean indicating whether this BitSet is empty |
length
open fun length(): Int
Returns the "logical size" of this BitSet
: the index of the highest set bit in the BitSet
plus one. Returns zero if the BitSet
contains no set bits.
Return | |
---|---|
Int |
the logical size of this BitSet |
nextClearBit
open fun nextClearBit(fromIndex: Int): Int
Returns the index of the first bit that is set to false
that occurs on or after the specified starting index.
Parameters | |
---|---|
fromIndex |
Int: the index to start checking from (inclusive) |
Return | |
---|---|
Int |
the index of the next clear bit |
Exceptions | |
---|---|
java.lang.IndexOutOfBoundsException |
if the specified index is negative |
nextSetBit
open fun nextSetBit(fromIndex: Int): Int
Returns the index of the first bit that is set to 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:
<code>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 } }</code>
Parameters | |
---|---|
fromIndex |
Int: the index to start checking from (inclusive) |
Return | |
---|---|
Int |
the index of the next set bit, or -1 if there is no such bit |
Exceptions | |
---|---|
java.lang.IndexOutOfBoundsException |
if the specified index is negative |
or
open fun or(set: BitSet!): Unit
Performs a logical OR of this bit set with the bit set argument. This bit set is modified so that a bit in it has the value 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
.
Parameters | |
---|---|
set |
BitSet!: a bit set |
previousClearBit
open fun previousClearBit(fromIndex: Int): Int
Returns the index of the nearest bit that is set to 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.
Parameters | |
---|---|
fromIndex |
Int: the index to start checking from (inclusive) |
Return | |
---|---|
Int |
the index of the previous clear bit, or -1 if there is no such bit |
Exceptions | |
---|---|
java.lang.IndexOutOfBoundsException |
if the specified index is less than -1 |
previousSetBit
open fun previousSetBit(fromIndex: Int): Int
Returns the index of the nearest bit that is set to 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:
<code>for (int i = bs.length(); (i = bs.previousSetBit(i-1)) >= 0; ) { // operate on index i here }</code>
Parameters | |
---|---|
fromIndex |
Int: the index to start checking from (inclusive) |
Return | |
---|---|
Int |
the index of the previous set bit, or -1 if there is no such bit |
Exceptions | |
---|---|
java.lang.IndexOutOfBoundsException |
if the specified index is less than -1 |
set
open fun set(bitIndex: Int): Unit
Sets the bit at the specified index to true
.
Parameters | |
---|---|
bitIndex |
Int: a bit index |
Exceptions | |
---|---|
java.lang.IndexOutOfBoundsException |
if the specified index is negative |
set
open fun set(
bitIndex: Int,
value: Boolean
): Unit
Sets the bit at the specified index to the specified value.
Parameters | |
---|---|
bitIndex |
Int: a bit index |
value |
Boolean: a boolean value to set |
Exceptions | |
---|---|
java.lang.IndexOutOfBoundsException |
if the specified index is negative |
set
open fun set(
fromIndex: Int,
toIndex: Int
): Unit
Sets the bits from the specified fromIndex
(inclusive) to the specified toIndex
(exclusive) to true
.
Parameters | |
---|---|
fromIndex |
Int: index of the first bit to be set |
toIndex |
Int: index after the last bit to be set |
Exceptions | |
---|---|
java.lang.IndexOutOfBoundsException |
if fromIndex is negative, or toIndex is negative, or fromIndex is larger than toIndex |
set
open fun set(
fromIndex: Int,
toIndex: Int,
value: Boolean
): Unit
Sets the bits from the specified fromIndex
(inclusive) to the specified toIndex
(exclusive) to the specified value.
Parameters | |
---|---|
fromIndex |
Int: index of the first bit to be set |
toIndex |
Int: index after the last bit to be set |
value |
Boolean: value to set the selected bits to |
Exceptions | |
---|---|
java.lang.IndexOutOfBoundsException |
if fromIndex is negative, or toIndex is negative, or fromIndex is larger than toIndex |
size
open fun size(): Int
Returns the number of bits of space actually in use by this BitSet
to represent bit values. The maximum element in the set is the size - 1st element.
Return | |
---|---|
Int |
the number of bits currently in this bit set |
stream
open fun stream(): IntStream!
Returns a stream of indices for which this 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 stream binds to this bit set when the terminal stream operation commences (specifically, the spliterator for the stream is late-binding). If the bit set is modified during that operation then the result is undefined.
Return | |
---|---|
IntStream! |
a stream of integers representing set indices |
toByteArray
open fun toByteArray(): ByteArray!
Returns a new byte array containing all the bits in this bit set.
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
.
Return | |
---|---|
ByteArray! |
a byte array containing a little-endian representation of all the bits in this bit set |
toLongArray
open fun toLongArray(): LongArray!
Returns a new long array containing all the bits in this bit set.
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
.
Return | |
---|---|
LongArray! |
a long array containing a little-endian representation of all the bits in this bit set |
toString
open fun toString(): String
Returns a string representation of this bit set. For every index for which this 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();
drPepper.toString()
returns "{}
".
drPepper.set(2);
drPepper.toString()
returns "{2}
".
drPepper.set(4); drPepper.set(10);
drPepper.toString()
returns "{2, 4, 10}
".
Return | |
---|---|
String |
a string representation of this bit set |
valueOf
open static fun valueOf(longs: LongArray!): BitSet!
Returns a new bit set containing all the bits in the given long array.
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))
.
Parameters | |
---|---|
longs |
LongArray!: a long array containing a little-endian representation of a sequence of bits to be used as the initial bits of the new bit set |
Return | |
---|---|
BitSet! |
a BitSet containing all the bits in the long array |
valueOf
open static fun valueOf(lb: LongBuffer!): BitSet!
Returns a new bit set containing all the bits in the given long buffer between its position and limit.
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.
Parameters | |
---|---|
lb |
LongBuffer!: 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 set |
Return | |
---|---|
BitSet! |
a BitSet containing all the bits in the buffer in the specified range |
valueOf
open static fun valueOf(bytes: ByteArray!): BitSet!
Returns a new bit set containing all the bits in the given byte array.
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))
.
Parameters | |
---|---|
bytes |
ByteArray!: a byte array containing a little-endian representation of a sequence of bits to be used as the initial bits of the new bit set |
Return | |
---|---|
BitSet! |
a BitSet containing all the bits in the byte array |
valueOf
open static fun valueOf(bb: ByteBuffer!): BitSet!
Returns a new bit set containing all the bits in the given byte buffer between its position and limit.
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.
Parameters | |
---|---|
bb |
ByteBuffer!: 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 set |
Return | |
---|---|
BitSet! |
a BitSet containing all the bits in the buffer in the specified range |
xor
open fun xor(set: BitSet!): Unit
Performs a logical XOR of this bit set with the bit set argument. This bit set is modified so that a bit in it has the value true
if and only if one of the following statements holds:
- The bit initially has the value
true
, and the corresponding bit in the argument has the valuefalse
. - The bit initially has the value
false
, and the corresponding bit in the argument has the valuetrue
.
Parameters | |
---|---|
set |
BitSet!: a bit set |