Ah, I just saw on second reading that you want to implement something for currency exchange rates, not MonetaryAmounts. Still, don't use Float, use ScaledDecimal or FixedPoint and make sure it NEVER contains a Float. You'll get into all kinds of strange problems, starting with Imports from datasources like Yahoo or whatever. I'd subclass Object, and make the new class hold the exchange rates as a ScaledDecimal with a well-defined scale (like 4 or 6 or even 8 digits if you want). Joachim Am 11.01.15 um 10:28 schrieb Joachim Tuchel:
Hilaire,
unless you have very (very very) specific needs, I would strongly discourage you to use Float for anything related to Money or Percentages.
We use a subclass of Object for MonetaryAmounts and implemented most of the protocol of Magnitude. But, most importantly, the amount instVar is made sure to always hold instances of ScaledDecimal (in VA Smalltalk, that is).
Joachim
Am 11.01.15 um 10:25 schrieb Hilaire:
Le 11/01/2015 09:06, stepharo a écrit :
Hilaire
what is your requirement?
Stef
I want to create a currency object, basically a Float with an attribute to specify the currency unit.
Hilaire