Package org.projog.clp

Class VariableState

java.lang.Object

org.projog.clp.VariableState

public final class VariableState
extends java.lang.Object

Represents the possible values for a variable.

Field Summary

Fields

Modifier and Type	Field	Description
private NumberSet	bitset	The set of all possible values for this VariableState.
private static NumberSet	CORRUPT	Used to indicate a VariableState has become corrupt.
private long	max	The maximum possible value for this VariableState.
private long	min	The minimum possible value for this VariableState.

Constructor Summary

Constructors

Modifier	Constructor	Description
	VariableState()	Creates a VariableState with the full range of possible values.
private	VariableState(long min, long max, NumberSet bitset)
private	VariableState(VariableState original)

Method Summary

Modifier and Type	Method	Description
static VariableState	and(VariableState a, VariableState b)	Return the result of performing a logical "and" on the two given VariableStates.
VariableState	copy()
long	count()
private VariableStateResult	fail()
long	getMax()
long	getMin()
Possibilities	getPossibilities()
boolean	isCorrupt()
boolean	isSingleValue()
private static long	max(VariableState a, VariableState b)
private static long	min(VariableState a, VariableState b)
VariableStateResult	setMax(long max)
VariableStateResult	setMin(long min)
VariableStateResult	setNot(long not)
VariableStateResult	setValue(long value)
private static NumberSet	squashBitSet(VariableState s, long newMin, long newMax)
private static VariableState	squashVariableState(VariableState s, long newMin, long newMax)
java.lang.String	toString()
private void	validate()

Methods inherited from class java.lang.Object

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

Field Detail

CORRUPT

private static final NumberSet CORRUPT

Used to indicate a VariableState has become corrupt.

If bitset is assigned to CORRUPT then that indicates the VariableState has become corrupt and should no longer be used.

For example, a VariableState would become corrupt if it had a minimum value of 7 and an attempt was made to set its maximum value to 6.

min

private long min

The minimum possible value for this VariableState.

max

private long max

The maximum possible value for this VariableState.

bitset

private NumberSet bitset

The set of all possible values for this VariableState.

If null then indicates that all numbers in the range min to max (inclusive) are possible values for this VariableState.

If assigned to CORRUPT then indicates that this VariableState has become corrupt and should no longer be used.

Constructor Detail

VariableState

public VariableState()

Creates a VariableState with the full range of possible values.

VariableState

private VariableState(long min,
                      long max,
                      NumberSet bitset)

VariableState

private VariableState(VariableState original)

Method Detail

and

public static VariableState and(VariableState a,
                                VariableState b)

Return the result of performing a logical "and" on the two given VariableStates.

Returns:

a state representing a logical "and" of a and b, or null if no values shared between them

min

private static long min(VariableState a,
                        VariableState b)

max

private static long max(VariableState a,
                        VariableState b)

squashVariableState

private static VariableState squashVariableState(VariableState s,
                                                 long newMin,
                                                 long newMax)

squashBitSet

private static NumberSet squashBitSet(VariableState s,
                                      long newMin,
                                      long newMax)

getMin

public long getMin()

getMax

public long getMax()

setValue

public VariableStateResult setValue(long value)

setMin

public VariableStateResult setMin(long min)

setMax

public VariableStateResult setMax(long max)

setNot

public VariableStateResult setNot(long not)

copy

public VariableState copy()

count

public long count()

getPossibilities

public Possibilities getPossibilities()

fail

private VariableStateResult fail()

validate

private void validate()

isSingleValue

public boolean isSingleValue()

isCorrupt

public boolean isCorrupt()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object