org.basex.util

Class BitArray

java.lang.Object

org.basex.util.BitArray

public final class BitArray
extends java.lang.Object

Bit array that grows when needed. The implementation is similar to BitSet.

Author:

BaseX Team 2005-12, BSD License, Dimitar Popov

Constructor Summary

Constructors

Constructor and Description
BitArray() Construct a new bit array.
BitArray(int n) Construct a new bit array with the specified number of bits.
BitArray(long[] a, int l) Construct a new bit array with the specified backing array.

Method Summary

Methods

Modifier and Type	Method and Description
void	clear(int i) Set the ith bit to 0.
boolean	get(int i) Get the value of the ith bit.
boolean	getAll() Are all bits set?
void	init() Initialize the bit array with an empty array.
int	nextClearBit(int i) Get the next bit set to 0, starting from the ith bit.
void	set(int i) Set the ith bit to 1.
void	setAll() Set all bits.
void	setWords(long[] a, int l) Initialize the bit array with the specified backing array.
long[]	toArray() The word array used to store the bits.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

BitArray

public BitArray()

Construct a new bit array.

BitArray

public BitArray(int n)

Construct a new bit array with the specified number of bits.

Parameters:

n - initial number of bits (> 0)

BitArray

public BitArray(long[] a,
        int l)

Construct a new bit array with the specified backing array.

Parameters:

a - array with bits

l - number of used bits

Method Detail

init

public void init()

Initialize the bit array with an empty array.

setWords

public void setWords(long[] a,
            int l)

Initialize the bit array with the specified backing array.

Parameters:

a - array with bits

l - number of used bits

toArray

public long[] toArray()

The word array used to store the bits. The array is shrunk to the last word, where a bit is set.

Returns:

array of longs

get

public boolean get(int i)

Get the value of the i^th bit.

Parameters:

i - index of the bit

Returns:

true if the i^th bit is set

set

public void set(int i)

Set the i^th bit to 1.

Parameters:

i - index of the bit

setAll

public void setAll()

Set all bits.

getAll

public boolean getAll()

Are all bits set?

Returns:

Whether all bits are set.

clear

public void clear(int i)

Set the i^th bit to 0.

Parameters:

i - index of the bit

nextClearBit

public int nextClearBit(int i)

Get the next bit set to 0, starting from the i^th bit.

Parameters:

i - index from which to start the search (inclusive)

Returns:

index of the next clear bit after the i^th bit