Money.java

package mf;

/*Generated by MPS */

import java.math.BigInteger;

public class Money implements Comparable {
  private BigInteger myAmount;
  private Currency myCurrency;
  public Money(double amount, Currency currency) {
    this.myAmount = BigInteger.valueOf(Math.round(amount * 100));
    this.myCurrency = currency;
  }
  public Money(long amount, Currency currency) {
    this.myAmount = BigInteger.valueOf(amount * 100);
    this.myCurrency = currency;
  }
  private Money(BigInteger amountInPennies, Currency currency) {
    assert amountInPennies != null;
    assert currency != null;
    this.myAmount = amountInPennies;
    this.myCurrency = currency;
  }
  public Money add(Money arg) {
    checkSameCurrencies(arg);
    return new Money(myAmount.add(arg.myAmount), myCurrency);
  }
  public Money subtract(Money arg) {
    return this.add(arg.negate());
  }
  /*package*/ void checkSameCurrencies(Money arg) {
    if (!(myCurrency.equals(arg.myCurrency))) {
      throw new IllegalArgumentException("currency mismatch");
    }
  }
  public Money negate() {
    return new Money(myAmount.negate(), myCurrency);
  }
  /*package*/ double amount() {
    return myAmount.doubleValue() / 100;
  }
  public Currency currency() {
    return myCurrency;
  }
  @Override
  public int compareTo(Object arg) {
    throw new RuntimeException("??");
  }
  public int compareTo(Money arg) {
    checkSameCurrencies(arg);
    return myAmount.compareTo(arg.myAmount);
  }
  @Override
  public boolean equals(Object arg) {
    if (!((arg instanceof Money))) {
      return false;
    }
    Money other = (Money) arg;
    return (myCurrency.equals(other.myCurrency) && (myAmount.equals(other.myAmount)));
  }
  public String formatString() {
    return myCurrency.formatString(amount());
  }
  public boolean greaterThan(Money arg) {
    return (this.compareTo(arg) == 1);
  }
  public boolean lessThan(Money arg) {
    return (this.compareTo(arg) == -1);
  }
  @Override
  public int hashCode() {
    return myAmount.hashCode();
  }
  public boolean isNegative() {
    return (myAmount.compareTo(BigInteger.ZERO) == -1);
  }
  public boolean isPositive() {
    return (myAmount.compareTo(BigInteger.ZERO) == 1);
  }
  public boolean isZero() {
    return myAmount.signum() == 0;
  }
  public String localString() {
    return myCurrency.getFormat().format(amount());
  }
  public Money multiply(double arg) {
    return new Money(amount() * arg, myCurrency);
  }
  @Override
  public String toString() {
    return myCurrency.toString() + " " + amount();
  }
  public Money[] divide(int denominator) {
    BigInteger bigDenominator = BigInteger.valueOf(denominator);
    Money[] result = new Money[denominator];
    BigInteger simpleResult = myAmount.divide(bigDenominator);
    for (int i = 0; i < denominator; i++) {
      result[i] = new Money(simpleResult, myCurrency);
    }
    int remainder = myAmount.subtract(simpleResult.multiply(bigDenominator)).intValue();
    for (int i = 0; i < remainder; i++) {
      result[i] = result[i].add(new Money(BigInteger.valueOf(1), myCurrency));
    }
    return result;
  }
  public static Money dollars(double amount) {
    return new Money(amount, Currency.USD);
  }
}