/*******************************************************************************
* Copyright (c) 2002 - 2006 IBM Corporation.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package com.ibm.wala.fixpoint;
import com.ibm.wala.util.debug.Assertions;
import com.ibm.wala.util.debug.UnimplementedError;
/**
* An operator of the form lhs = op (rhs)
*/
@SuppressWarnings("rawtypes")
public abstract class UnaryOperator<T extends IVariable> extends AbstractOperator<T> implements FixedPointConstants {
/**
* Evaluate this equation, setting a new value for the left-hand side.
*
* @return true if the lhs value changes. false otherwise.
*/
public abstract byte evaluate(T lhs, T rhs);
/**
* Create an equation which uses this operator Override in subclasses for
* efficiency.
*/
public UnaryStatement<T> makeEquation(T lhs, T rhs) {
return new BasicUnaryStatement<T>(lhs, this, rhs);
}
public boolean isIdentity() {
return false;
}
@Override
public byte evaluate(T lhs, T[] rhs) throws UnimplementedError {
// this should never be called. Use the other, more efficient form.
Assertions.UNREACHABLE();
return 0;
}
}