From: Matts Kallioniemi <matts@pi.se>
Date: Thu, 23 May 1996 03:41:16 +0800
To: bryce@digicash.com
Subject: Re: The Crisis with Remailers
Message-ID: <2.2.32.19960522141400.00340478@mail.pi.se>
MIME-Version: 1.0
Content-Type: text/plain


At 11:58 1996-05-22 +0200, bryce@digicash.com wrote:
>Matts, _floating_ point numbers  are _not_ useful 
>if you want to handle a number with a lot of precision, nor
>indeed, if you want to be able to _know_ the precision!  If you
>have a number that represents money, you want to know the 
>precision!

As I said yesterday, there are in fact people dealing with billions
in all major currencies that keep their money in 64 bit floats. The
precision is far better than anything you can do in 32 bit integers.
Trust me, this is a fact and can easily be proven.

>I shall try to refrain from taking umbrage at your comment that
>DigiCash is "not real".  

The "get real" was a pun on floats. Many languages, such as Pascal,
calls them real numbers. Sorry I forgot the smiley.

>Also that DigiCash doesn't "do" currency.  What could you possibly
>mean by that?

In my client (2.1.5a MT) there is no way to do currency conversion.
If I go to a FIM or DEM merchant I can't buy anything in the store.

This will probably change in the near future when a new client is
released, and then we'll have the question of how to represent these
currencies in one wallet.

What do you think will happen if you have a one italian lira coin and
you try to deposit it with Mark Twain's USD account? With integer
math it won't be pretty.

>For further reading on floating point and other representations
>of numbers in computing, I recommend any good introductory
>university text on mathematical computing.  Sorry I don't have
>mine handy or I'd give you a specific reference.

Maybe you should start looking for it. You'll need it when the lira
arrives...


Regards,

Matts