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Groovy: A powerful, dynamic language for the JVM
/*
* Copyright 2003-2007 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.codehaus.groovy.runtime.typehandling;
import java.math.BigDecimal;
/**
* BigDecimal NumberMath operations
*
* @author Steve Goetze
*/
public class BigDecimalMath extends NumberMath {
//This is an arbitrary value, picked as a reasonable choice for a rounding point
//for typical user math.
public static final int MAX_DIVISION_SCALE = 10;
public static final BigDecimalMath INSTANCE = new BigDecimalMath();
private BigDecimalMath() {}
protected Number absImpl(Number number) {
return toBigDecimal(number).abs();
}
public Number addImpl(Number left, Number right) {
return toBigDecimal(left).add(toBigDecimal(right));
}
public Number subtractImpl(Number left, Number right) {
return toBigDecimal(left).subtract(toBigDecimal(right));
}
public Number multiplyImpl(Number left, Number right) {
return toBigDecimal(left).multiply(toBigDecimal(right));
}
public Number divideImpl(Number left, Number right) {
//Hack until Java 1.5 BigDecimal is available. For now, pick
//a result scale which is the maximum of the scale of the
//two operands and an arbitrary maximum (similar to what a
//handheld calculator would do). Then, normalize the result
//by removing any trailing zeros.
BigDecimal bigLeft = toBigDecimal(left);
BigDecimal bigRight = toBigDecimal(right);
int scale = Math.max(bigLeft.scale(), bigRight.scale());
return normalize(bigLeft.divide(bigRight, Math.max(scale, MAX_DIVISION_SCALE), BigDecimal.ROUND_HALF_UP));
}
public int compareToImpl(Number left, Number right) {
return toBigDecimal(left).compareTo(toBigDecimal(right));
}
private BigDecimal normalize(BigDecimal number) {
// we have to take care of the case number==0, because 0 can have every
// scale and the test in the while loop would never end
if (number.signum()==0) {
// the smallest scale for 0 is 0
return number.setScale(0);
}
// rescale until we found the smallest possible scale
try {
while (true) {
number = number.setScale(number.scale()-1);
}
} catch (ArithmeticException e) {
return number;
}
}
protected Number unaryMinusImpl(Number left) {
return toBigDecimal(left).negate();
}
}