Package org.apache.commons.lang3.util

Class FluentBitSet

java.lang.Object

org.apache.commons.lang3.util.FluentBitSet

All Implemented Interfaces:

Serializable, Cloneable

public final class FluentBitSet
extends Object
implements Cloneable, Serializable

A fluent BitSet with additional operations.

Originally from Apache Commons VFS with more added to act as a fluent replacement for BitSet.

Since:

3.13.0

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
FluentBitSet()	Creates a new bit set.
FluentBitSet(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.
FluentBitSet(BitSet set)	Creates a new instance for the given bit set.

Method Summary

Modifier and Type	Method	Description
FluentBitSet	and(BitSet set)	Performs a logical AND of this target bit set with the argument bit set.
FluentBitSet	and(FluentBitSet set)	Performs a logical AND of this target bit set with the argument bit set.
FluentBitSet	andNot(BitSet set)	Clears all of the bits in this BitSet whose corresponding bit is set in the specified BitSet.
FluentBitSet	andNot(FluentBitSet set)	Clears all of the bits in this BitSet whose corresponding bit is set in the specified BitSet.
BitSet	bitSet()	Gets the wrapped bit set.
int	cardinality()	Returns the number of bits set to true in this BitSet.
FluentBitSet	clear()	Sets all of the bits in this BitSet to false.
FluentBitSet	clear(int bitIndex)	Sets the bit specified by the index to false.
FluentBitSet	clear(int... bitIndexArray)	Sets the bits specified by the indexes to false.
FluentBitSet	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.
boolean	equals(Object obj)
FluentBitSet	flip(int bitIndex)	Sets the bit at the specified index to the complement of its current value.
FluentBitSet	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	get(int bitIndex)	Returns the value of the bit with the specified index.
FluentBitSet	get(int fromIndex, int toIndex)	Returns a new BitSet composed of bits from this BitSet from fromIndex (inclusive) to toIndex (exclusive).
int	hashCode()
boolean	intersects(BitSet set)	Returns true if the specified BitSet has any bits set to true that are also set to true in this BitSet.
boolean	intersects(FluentBitSet 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.
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.
FluentBitSet	or(BitSet set)	Performs a logical OR of this bit set with the bit set argument.
FluentBitSet	or(FluentBitSet set)	Performs a logical OR of this bit set with the bit set argument.
FluentBitSet	or(FluentBitSet... set)	Performs a logical OR of this bit set with the bit set arguments.
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.
FluentBitSet	set(int bitIndex)	Sets the bit at the specified index to true.
FluentBitSet	set(int... bitIndexArray)	Sets the bit at the specified indexes to true.
FluentBitSet	set(int bitIndex, boolean value)	Sets the bit at the specified index to the specified value.
FluentBitSet	set(int fromIndex, int toIndex)	Sets the bits from the specified fromIndex (inclusive) to the specified toIndex (exclusive) to true.
FluentBitSet	set(int fromIndex, int toIndex, boolean value)	Sets the bits from the specified fromIndex (inclusive) to the specified toIndex (exclusive) to the specified value.
FluentBitSet	setInclusive(int fromIndex, int toIndex)	Sets the bits from the specified fromIndex (inclusive) to the specified toIndex (inclusive) to true.
int	size()	Returns the number of bits of space actually in use by this BitSet to represent bit values.
IntStream	stream()	Returns a stream of indices for which this BitSet contains a bit in the set state.
byte[]	toByteArray()	Returns a new byte array containing all the bits in this bit set.
long[]	toLongArray()	Returns a new byte array containing all the bits in this bit set.
String	toString()
FluentBitSet	xor(BitSet set)	Performs a logical XOR of this bit set with the bit set argument.
FluentBitSet	xor(FluentBitSet set)	Performs a logical XOR of this bit set with the bit set argument.

Methods inherited from class java.lang.Object

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

Constructor Details

FluentBitSet

public FluentBitSet()

Creates a new bit set. All bits are initially false.

FluentBitSet

public FluentBitSet(BitSet set)

Creates a new instance for the given bit set.

Parameters:

set - The bit set to wrap.

FluentBitSet

public FluentBitSet(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. All bits are initially false.

Parameters:

nbits - the initial size of the bit set.

Throws:

NegativeArraySizeException - if the specified initial size is negative.

Method Details

and

public FluentBitSet and(BitSet set)

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 - a bit set.

Returns:

this instance.

and

public FluentBitSet and(FluentBitSet set)

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 - a bit set.

Returns:

this instance.

andNot

public FluentBitSet andNot(BitSet set)

Clears all of the bits in this BitSet whose corresponding bit is set in the specified BitSet.

Parameters:

set - the BitSet with which to mask this BitSet.

Returns:

this instance.

andNot

public FluentBitSet andNot(FluentBitSet set)

Clears all of the bits in this BitSet whose corresponding bit is set in the specified BitSet.

Parameters:

set - the BitSet with which to mask this BitSet.

Returns:

this instance.

bitSet

public BitSet bitSet()

Gets the wrapped bit set.

Returns:

the wrapped bit set.

cardinality

public int cardinality()

Returns the number of bits set to true in this BitSet.

Returns:

the number of bits set to true in this BitSet.

clear

public FluentBitSet clear()

Sets all of the bits in this BitSet to false.

Returns:

this instance.

clear

public FluentBitSet clear(int... bitIndexArray)

Sets the bits specified by the indexes to false.

Parameters:

bitIndexArray - the index of the bit to be cleared.

Returns:

this instance.

Throws:

IndexOutOfBoundsException - if the specified index is negative.

clear

public FluentBitSet clear(int bitIndex)

Sets the bit specified by the index to false.

Parameters:

bitIndex - the index of the bit to be cleared.

Returns:

this instance.

Throws:

IndexOutOfBoundsException - if the specified index is negative.

clear

public FluentBitSet clear(int fromIndex,
 int toIndex)

Sets the bits from the specified fromIndex (inclusive) to the specified toIndex (exclusive) to false.

Parameters:

fromIndex - index of the first bit to be cleared.

toIndex - index after the last bit to be cleared.

Returns:

this instance.

Throws:

IndexOutOfBoundsException - if fromIndex is negative, or toIndex is negative, or fromIndex is larger than toIndex.

clone

public Object clone()

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.

Overrides:

clone in class Object

Returns:

a clone of this bit set

See Also:

• size()

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

flip

public FluentBitSet flip(int bitIndex)

Sets the bit at the specified index to the complement of its current value.

Parameters:

bitIndex - the index of the bit to flip.

Returns:

this instance.

Throws:

IndexOutOfBoundsException - if the specified index is negative.

flip

public FluentBitSet 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.

Parameters:

fromIndex - index of the first bit to flip.

toIndex - index after the last bit to flip.

Returns:

this instance.

Throws:

IndexOutOfBoundsException - if fromIndex is negative, or toIndex is negative, or fromIndex is larger than toIndex.

get

public boolean get(int bitIndex)

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 - the bit index.

Returns:

the value of the bit with the specified index.

Throws:

IndexOutOfBoundsException - if the specified index is negative.

get

public FluentBitSet get(int fromIndex,
 int toIndex)

Returns a new BitSet composed of bits from this BitSet from fromIndex (inclusive) to toIndex (exclusive).

Parameters:

fromIndex - index of the first bit to include.

toIndex - index after the last bit to include.

Returns:

a new BitSet from a range of this BitSet.

Throws:

IndexOutOfBoundsException - if fromIndex is negative, or toIndex is negative, or fromIndex is larger than toIndex.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

intersects

public boolean intersects(BitSet set)

Returns true if the specified BitSet has any bits set to true that are also set to true in this BitSet.

Parameters:

set - BitSet to intersect with.

Returns:

boolean indicating whether this BitSet intersects the specified BitSet.

intersects

public boolean intersects(FluentBitSet set)

Returns true if the specified BitSet has any bits set to true that are also set to true in this BitSet.

Parameters:

set - BitSet to intersect with.

Returns:

boolean indicating whether this BitSet intersects the specified BitSet.

isEmpty

public boolean isEmpty()

Returns true if this BitSet contains no bits that are set to true.

Returns:

boolean indicating whether this BitSet is empty.

length

public int length()

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.

Returns:

the logical size of this BitSet.

nextClearBit

public 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.

Parameters:

fromIndex - the index to start checking from (inclusive).

Returns:

the index of the next clear bit.

Throws:

IndexOutOfBoundsException - if the specified index is negative.

nextSetBit

public 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. 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
     }
 }
 

Parameters:

fromIndex - the index to start checking from (inclusive).

Returns:

the index of the next set bit, or -1 if there is no such bit.

Throws:

IndexOutOfBoundsException - if the specified index is negative.

or

public FluentBitSet or(BitSet set)

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 - a bit set.

Returns:

this instance.

or

public FluentBitSet or(FluentBitSet... set)

Performs a logical OR of this bit set with the bit set arguments. 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 - a bit set.

Returns:

this instance.

or

public FluentBitSet or(FluentBitSet set)

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 - a bit set.

Returns:

this instance.

previousClearBit

public 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. If no such bit exists, or if -1 is given as the starting index, then -1 is returned.

Parameters:

fromIndex - the index to start checking from (inclusive).

Returns:

the index of the previous clear bit, or -1 if there is no such bit.

Throws:

IndexOutOfBoundsException - if the specified index is less than -1.

previousSetBit

public 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. 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
 }
 

Parameters:

fromIndex - the index to start checking from (inclusive)

Returns:

the index of the previous set bit, or -1 if there is no such bit

Throws:

IndexOutOfBoundsException - if the specified index is less than -1

set

public FluentBitSet set(int... bitIndexArray)

Sets the bit at the specified indexes to true.

Parameters:

bitIndexArray - a bit index array.

Returns:

this instance.

Throws:

IndexOutOfBoundsException - if the specified index is negative.

set

public FluentBitSet set(int bitIndex)

Sets the bit at the specified index to true.

Parameters:

bitIndex - a bit index

Returns:

this instance.

Throws:

IndexOutOfBoundsException - if the specified index is negative

set

public FluentBitSet set(int bitIndex,
 boolean value)

Sets the bit at the specified index to the specified value.

Parameters:

bitIndex - a bit index.

value - a boolean value to set.

Returns:

this instance.

Throws:

IndexOutOfBoundsException - if the specified index is negative.

set

public FluentBitSet set(int fromIndex,
 int toIndex)

Sets the bits from the specified fromIndex (inclusive) to the specified toIndex (exclusive) to true.

Parameters:

fromIndex - index of the first bit to be set.

toIndex - index after the last bit to be set.

Returns:

this instance.

Throws:

IndexOutOfBoundsException - if fromIndex is negative, or toIndex is negative, or fromIndex is larger than toIndex.

set

public FluentBitSet set(int fromIndex,
 int toIndex,
 boolean value)

Sets the bits from the specified fromIndex (inclusive) to the specified toIndex (exclusive) to the specified value.

Parameters:

fromIndex - index of the first bit to be set.

toIndex - index after the last bit to be set.

value - value to set the selected bits to.

Returns:

this instance.

Throws:

IndexOutOfBoundsException - if fromIndex is negative, or toIndex is negative, or fromIndex is larger than toIndex.

setInclusive

public FluentBitSet setInclusive(int fromIndex,
 int toIndex)

Sets the bits from the specified fromIndex (inclusive) to the specified toIndex (inclusive) to true.

Parameters:

fromIndex - index of the first bit to be set

toIndex - index of the last bit to be set

Returns:

this instance.

Throws:

IndexOutOfBoundsException - if fromIndex is negative, or toIndex is negative, or fromIndex is larger than toIndex

size

public int size()

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.

Returns:

the number of bits currently in this bit set.

stream

public IntStream stream()

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 bit set must remain constant during the execution of the terminal stream operation. Otherwise, the result of the terminal stream operation is undefined.

Returns:

a stream of integers representing set indices.

Since:

1.8

toByteArray

public byte[] toByteArray()

Returns a new byte array containing all the bits in this bit set.

More precisely, if:

1. byte[] bytes = s.toByteArray();
2. then bytes.length == (s.length()+7)/8 and
3. s.get(n) == ((bytes[n/8] & (1<<(n%8))) != 0)
4. for all n < 8 * bytes.length.

Returns:

a byte array containing a little-endian representation of all the bits in this bit set

toLongArray

public long[] toLongArray()

Returns a new byte array containing all the bits in this bit set.

More precisely, if:

1. long[] longs = s.toLongArray();
2. then longs.length == (s.length()+63)/64 and
3. s.get(n) == ((longs[n/64] & (1L<<(n%64))) != 0)
4. for all n < 64 * longs.length.

Returns:

a byte array containing a little-endian representation of all the bits in this bit set

toString

public String toString()

Overrides:

toString in class Object

xor

public FluentBitSet xor(BitSet set)

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 value false.
• The bit initially has the value false, and the corresponding bit in the argument has the value true.

Parameters:

set - a bit set

Returns:

this instance.

xor

public FluentBitSet xor(FluentBitSet set)

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 value false.
• The bit initially has the value false, and the corresponding bit in the argument has the value true.

Parameters:

set - a bit set

Returns:

this instance.