Class NullaryOperator<T extends IVariable<T>>

java.lang.Object

com.ibm.wala.fixpoint.AbstractOperator<T>

com.ibm.wala.fixedpoint.impl.NullaryOperator<T>

All Implemented Interfaces:

FixedPointConstants

Direct Known Subclasses:

TypeInference.DeclaredTypeOperator

public abstract class NullaryOperator<T extends IVariable<T>>
extends AbstractOperator<T>

An operator of the form lhs = op

Field Summary

Fields inherited from interface FixedPointConstants

CHANGED, CHANGED_AND_FIXED, CHANGED_MASK, FIXED_MASK, NOT_CHANGED, NOT_CHANGED_AND_FIXED, SIDE_EFFECT_MASK

Modifier and Type	Field	Description
static final byte	CHANGED	A return value which indicates that a lhs has changed, and the statement might need to be evaluated again.
static final byte	CHANGED_AND_FIXED	A return value which indicates that lhs has changed, and the statement need not be evaluated again.
static final int	CHANGED_MASK	The bit-mask which defines the "CHANGED" flag
static final int	FIXED_MASK	The bit-mask which defines the "FIXED" flag
static final byte	NOT_CHANGED	A return value which indicates that lhs has not changed, and the statement might need to be evaluated again.
static final byte	NOT_CHANGED_AND_FIXED	A return value which indicates that lhs has not changed, and the statement need not be evaluated again.
static final int	SIDE_EFFECT_MASK	The bit-mask which defines the "SIDE EFFECT" flag

Constructor Summary

Constructors

Constructor	Description
NullaryOperator()

Method Summary

Modifier and Type	Method	Description
abstract byte	evaluate(T lhs)	Evaluate this equation, setting a new value for the left-hand side.
byte	evaluate(T lhs, T[] rhs)	Evaluate this equation, setting a new value for the left-hand side.

Methods inherited from class AbstractOperator

equals, hashCode, toString

Modifier and Type	Method	Description
abstract boolean	equals(Object o)
abstract int	hashCode()
abstract String	toString()

Methods inherited from class Object

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

Constructor Details

NullaryOperator

public NullaryOperator()

Method Details

evaluate

public byte evaluate(T lhs,
 T[] rhs)
              throws UnsupportedOperationException

Description copied from class: AbstractOperator

Evaluate this equation, setting a new value for the left-hand side.

Specified by:

evaluate in class AbstractOperator<T extends IVariable<T>>

Returns:

a code that indicates: 1) has the lhs value changed? 2) has this equation reached a fixed-point, in that we never have to evaluate the equation again, even if rhs operands change?

Throws:

UnsupportedOperationException

evaluate

public abstract byte evaluate(T lhs)

Evaluate this equation, setting a new value for the left-hand side.

Returns:

a constant defined by FixedPointConstants that reflects whether the lhs value changed