private static void AssertEqual(int expected, Integer value)
{
Assert.AreEqual(expected, (int)value);
}
public Integer(Integer value)
{
sign = value.sign;
this.value = value.value;
}
public Integer Add(Integer rhs)
{
return sign.IsOppositeOf(rhs.Sign).Accept(() => value.LessThan(rhs.value).Accept(() => new Integer(rhs.value.Subtract(value), rhs.IsPositive),
() => new Integer(value.Subtract(rhs.value), IsPositive)),
() => new Integer(value.Add(rhs.value), IsPositive.Or(rhs.IsPositive)));
}
public Integer ShiftRight(Integer places)
{
return places.Sign.IsNegative.Accept(() => ShiftLeft(places.value), () => ShiftRight(places.value));
}
public Integer Subtract(Integer rhs)
{
return Add(rhs.Negate());
}
public Bool LessThanOrEqualTo(Integer rhs)
{
return rhs.IsPositive.And(IsPositive.Not)
.Or(() => rhs.IsPositive.Accept(() => value.LessThanOrEqualTo(rhs.value),
() => IsPositive.Not.And(() => rhs.value.LessThanOrEqualTo(value))));
}
public Integer Multiply(Integer rhs)
{
var product = value.Multiply(rhs.value);
return new Integer(product, sign.EqualTo(rhs.sign));
}
public Bool LessThan(Integer rhs)
{
return rhs.IsPositive.And(IsPositive.Not)
.Or(() => rhs.IsPositive.Accept(() => value.LessThan(rhs.value),
() => IsNegative.And(() => rhs.value.LessThan(value))));
}
public Bool GreaterThanOrEqualTo(Integer rhs)
{
return rhs.LessThanOrEqualTo(this);
}
public Bool GreaterThan(Integer rhs)
{
return rhs.LessThan(this);
}
public Bool EqualTo(Integer rhs)
{
return sign.EqualTo(rhs.sign).And(() => value.EqualTo(rhs.value));
}
public DivisionResult<Integer> DivideBy(Integer rhs)
{
var result = value.DivideBy(rhs.value);
var quotient = new Integer(result.Quotient, sign.EqualTo(rhs.sign));
var remainder = new Integer(result.Remainder, sign);
return DivisionResult.Create(quotient, remainder);
}