antlr.collections.impl
Class BitSet

java.lang.Object
  |
  +--antlr.collections.impl.BitSet

All Implemented Interfaces:

java.lang.Cloneable

public class BitSet

extends java.lang.Object

implements java.lang.Cloneable

A BitSet to replace java.util.BitSet. Primary differences are that most set operators return new sets as opposed to oring and anding "in place". Further, a number of operations were added. I cannot contain a BitSet because there is no way to access the internal bits (which I need for speed) and, because it is final, I cannot subclass to add functionality. Consider defining set degree. Without access to the bits, I must call a method n times to test the ith bit...ack! Also seems like or() from util is wrong when size of incoming set is bigger than this.bits.length.

Author:

Terence Parr,
Pete Wells

Field Summary

protected long[]	bits The actual data bits
protected static int	BITS
protected static int	LOG_BITS
protected static int	MOD_MASK
protected static int	NIBBLE

Constructor Summary

BitSet()
Construct a bitset of size one word (64 bits)

BitSet(int nbits)
Construct a bitset given the size

BitSet(long[] bits_)
Construction from a static array of longs

Method Summary

void	add(int el) or this element into this set (grow as necessary to accommodate)
BitSet	and(BitSet a)
void	andInPlace(BitSet a)
private static long	bitMask(int bitNumber)
void	clear()
void	clear(int el)
java.lang.Object	clone()
int	degree()
boolean	equals(java.lang.Object obj) code "inherited" from java.util.BitSet
static Vector	getRanges(int[] elems) Find ranges in a set element array.
void	growToInclude(int bit) Grows the set to a larger number of bits.
boolean	member(int el)
boolean	nil()
BitSet	not()
void	notInPlace()
void	notInPlace(int maxBit) complement bits in the range 0..maxBit.
void	notInPlace(int minBit, int maxBit) complement bits in the range minBit..maxBit.
private int	numWordsToHold(int el)
static BitSet	of(int el)
BitSet	or(BitSet a) return this | a in a new set
void	orInPlace(BitSet a)
void	remove(int el)
private void	setSize(int nwords) Sets the size of a set.
int	size()
boolean	subset(BitSet a) Is this contained within a?
void	subtractInPlace(BitSet a) Subtract the elements of 'a' from 'this' in-place.
int[]	toArray()
java.lang.String	toString()
java.lang.String	toString(java.lang.String separator) Transform a bit set into a string by formatting each element as an integer
java.lang.String	toString(java.lang.String separator, CharFormatter formatter) Transform a bit set into a string of characters.
java.lang.String	toString(java.lang.String separator, Vector vocabulary) Create a string representation where instead of integer elements, the ith element of vocabulary is displayed instead.
java.lang.String	toStringOfHalfWords() Dump a comma-separated list of the words making up the bit set.
java.lang.String	toStringOfWords() Dump a comma-separated list of the words making up the bit set.
java.lang.String	toStringWithRanges(java.lang.String separator, CharFormatter formatter) Print out the bit set but collapse char ranges.
private static int	wordNumber(int bit)

Methods inherited from class java.lang.Object

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

Field Detail

BITS

protected static final int BITS

See Also:

Constant Field Values

NIBBLE

protected static final int NIBBLE

See Also:

Constant Field Values

LOG_BITS

protected static final int LOG_BITS

See Also:

Constant Field Values

MOD_MASK

protected static final int MOD_MASK

See Also:

Constant Field Values

bits

protected long[] bits

The actual data bits

Constructor Detail

BitSet

public BitSet()

Construct a bitset of size one word (64 bits)

BitSet

public BitSet(long[] bits_)

Construction from a static array of longs

BitSet

public BitSet(int nbits)

Construct a bitset given the size

Parameters:

nbits - The size of the bitset in bits

Method Detail

add

public void add(int el)

or this element into this set (grow as necessary to accommodate)

and

public BitSet and(BitSet a)

andInPlace

public void andInPlace(BitSet a)

bitMask

private static final long bitMask(int bitNumber)

clear

public void clear()

clear

public void clear(int el)

clone

public java.lang.Object clone()

Overrides:

clone in class java.lang.Object

degree

public int degree()

equals

public boolean equals(java.lang.Object obj)

code "inherited" from java.util.BitSet

Overrides:

equals in class java.lang.Object

getRanges

public static Vector getRanges(int[] elems)

Find ranges in a set element array. @param elems The array of elements representing the set, usually from Bit Set.toArray().

Returns:

Vector of ranges.

growToInclude

public void growToInclude(int bit)

Grows the set to a larger number of bits.

Parameters:

bit - element that must fit in set

member

public boolean member(int el)

nil

public boolean nil()

not

public BitSet not()

notInPlace

public void notInPlace()

notInPlace

public void notInPlace(int maxBit)

complement bits in the range 0..maxBit.

notInPlace

public void notInPlace(int minBit,
                       int maxBit)

complement bits in the range minBit..maxBit.

numWordsToHold

private final int numWordsToHold(int el)

of

public static BitSet of(int el)

or

public BitSet or(BitSet a)

return this | a in a new set

orInPlace

public void orInPlace(BitSet a)

remove

public void remove(int el)

setSize

private void setSize(int nwords)

Sets the size of a set.

Parameters:

nwords - how many words the new set should be

size

public int size()

subset

public boolean subset(BitSet a)

Is this contained within a?

subtractInPlace

public void subtractInPlace(BitSet a)

Subtract the elements of 'a' from 'this' in-place. Basically, just turn off all bits of 'this' that are in 'a'.

toArray

public int[] toArray()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

toString

public java.lang.String toString(java.lang.String separator)

Transform a bit set into a string by formatting each element as an integer

Returns:

A commma-separated list of values

toString

public java.lang.String toString(java.lang.String separator,
                                 CharFormatter formatter)

Transform a bit set into a string of characters.

Parameters:

formatter - An object implementing the CharFormatter interface.

Returns:

A commma-separated list of character constants.

toString

public java.lang.String toString(java.lang.String separator,
                                 Vector vocabulary)

Create a string representation where instead of integer elements, the ith element of vocabulary is displayed instead. Vocabulary is a Vector of Strings.

Returns:

A commma-separated list of character constants.

toStringOfHalfWords

public java.lang.String toStringOfHalfWords()

Dump a comma-separated list of the words making up the bit set. Split each 64 bit number into two more manageable 32 bit numbers. This generates a comma-separated list of C++-like unsigned long constants.

toStringOfWords

public java.lang.String toStringOfWords()

Dump a comma-separated list of the words making up the bit set. This generates a comma-separated list of Java-like long int constants.

toStringWithRanges

public java.lang.String toStringWithRanges(java.lang.String separator,
                                           CharFormatter formatter)

Print out the bit set but collapse char ranges.

wordNumber

private static final int wordNumber(int bit)