From: Sam Goldman <samgoldman@...>
Date: 2004-10-30T23:38:52+09:00
Subject: Re: Money Class (was Re: Rounding error, (100.0 * 9.95).to_i == 994)

And the subject takes up the whole first section of Test Driven 
Development by Kent Beck.

- Sam (new to the list)

Francis Hwang wrote:
> 
> On Oct 30, 2004, at 9:05 AM, Brian Schr�der wrote:
> 
>> Why not just use integer valued cent-counts?
> 
> 
> Sometimes that's not sufficient. If you're an organization that has to 
> deal with quantities and amounts priced in multiple currencies, you have 
> to store both the number and the currency itself. 5 Euros, 10 dollars, 
> 42000 Korean won, etc. Then if you are adding or comparing them to one 
> another you have to figure out how to sensibly model that. What's 5 
> Euros plus 10 dollars? Does it matter that the answer to that question 
> changes over time, as exchange rates are constantly fluctuating?
> 
> It's a pretty interesting little domain. Martin Fowler devotes a few 
> pages to it in Analysis Patterns.
> 
> F.
> 
>