org.key_project.util.bitops

Class ImmutableFixedLengthBitSet

java.lang.Object

org.key_project.util.bitops.ImmutableFixedLengthBitSet

public class ImmutableFixedLengthBitSet
extends java.lang.Object

Represents a non-negative number with access to single bits; the length of the bit set is fixed. Comparable to BitSet with fixed length. Objects of this class are immutable.

Author:

Dominic Scheurer

Field Summary

Fields

Modifier and Type	Field and Description
private boolean[]	bitSet
private int	value

Constructor Summary

Constructors

Modifier	Constructor and Description
private	ImmutableFixedLengthBitSet(boolean[] bitSet, int value) Constructs a new ImmutableFixedLengthBitSet from an explicit internal representation and value.
	ImmutableFixedLengthBitSet(int length) Constructs a new ImmutableFixedLengthBitSet for the given length.

Method Summary

Modifier and Type	Method and Description
java.util.ArrayList<java.lang.Integer>	getNonzeroPositions()
int	getNumOfZeroBits()
int	getValue()
ImmutableFixedLengthBitSet	inc() Returns a new ImmutableFixedLengthBitSet with a value incremented by one compared to this ImmutableFixedLengthBitSet.
private static int	intPow(int a, int b) Power function for integers.
ImmutableFixedLengthBitSet	setToValue(int value) Sets this ImmutableFixedLengthBitSet to the given value.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

bitSet

private boolean[] bitSet

value

private int value

Constructor Detail

ImmutableFixedLengthBitSet

public ImmutableFixedLengthBitSet(int length)

Constructs a new ImmutableFixedLengthBitSet for the given length. All bits are set to zero (so the ImmutableFixedLengthBitSet represents the number 0).

Parameters:

length - The length of the new ImmutableFixedLengthBitSet.

ImmutableFixedLengthBitSet

private ImmutableFixedLengthBitSet(boolean[] bitSet,
                                   int value)

Constructs a new ImmutableFixedLengthBitSet from an explicit internal representation and value. Note: It is not checked that the value really faithfully represents the bitSet, so callers are responsible to make sure that this property holds.

Parameters:

bitSet - The new bit set.

value - The value for bitSet.

Method Detail

getValue

public int getValue()

Returns:

The integer value represented by this ImmutableFixedLengthBitSet.

setToValue

public ImmutableFixedLengthBitSet setToValue(int value)

Sets this ImmutableFixedLengthBitSet to the given value.

Parameters:

value - Value to set the ImmutableFixedLengthBitSet to.

inc

public ImmutableFixedLengthBitSet inc()

Returns a new ImmutableFixedLengthBitSet with a value incremented by one compared to this ImmutableFixedLengthBitSet.

getNumOfZeroBits

public int getNumOfZeroBits()

Returns:

The number of bits in the ImmutableFixedLengthBitSet set to zero.

getNonzeroPositions

public java.util.ArrayList<java.lang.Integer> getNonzeroPositions()

Returns:

A list of all non-zero positions in the ImmutableFixedLengthBitSet.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

intPow

private static int intPow(int a,
                          int b)

Power function for integers.

Parameters:

a - The base.

b - The exponent.

Returns:

a^b.