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/**
*
*/
package de.fhswf.in.inf.upnfx.util;
/**
* An abstract class for calculations with unary operators.
*
* @author $Author: $
* @version $Revision: $, $Date: $ UTC
*/
public abstract class BinaryOperator implements Operator
{
/*
* (non-Javadoc)
*
* @see de.fhswf.in.inf.java1.aufgabe12.Operator#eval(java.util.Stack)
*/
@Override
public final void eval(ObservableDoubleStack stack)
{
if (stack == null)
{
throw new IllegalArgumentException("Stack must not be null.");
}
if (stack.size() < 2)
{
throw new IllegalArgumentException(
"Binary operation requires two operand.");
}
double d2 = stack.pop();
double d1 = stack.pop();
stack.push(eval(d1, d2));
}
/**
* This method implements the calculation.
*
* @param d1
* The first operator.
* @param d2
* The second operator.
* @return The result of the calculation.
*/
abstract double eval(double d1, double d2);
}
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