# Proposal for modifying gnucash to use exact quantities

Buddha Buck bmbuck@14850.com
Wed, 02 Aug 2000 08:50:41 -0400

```At 06:53 AM 8/2/00 -0500, Richard Wackerbarth wrote:

>Here, I think the question degenerates into "What is a commodity?"
>
>You and I view "\$/8 USD" and "\$/100 USD" as two different commodities. OTOH,
>I believes that Bill views them as the same commodity and feels that it is
>permissible to add them. I don't think that anyone proposes to add \$USD to
>\$CND.

There are several ways of looking at this, I guess...

I view "\$/8 USD" and "\$/8 USD" to be the -same- commodity (obviously).
You can add, subtract, and compare X \$/8 USD and y \$/8 USD.  They share the
same display function.

I view "\$/8 USD" and "\$/8 CND" to be -different- commodities.  You can't
add, subtract, or compare them.  The only permissible operation is a
conversion between them using an explicit conversion ratio -- with the
understanding that the conversion is not exact and may not be
reversible.  They may or may not share the same display function.

I view "\$/8 USD" and "\$/100 USD" to be -similar- commodities.  You can't
add or subtract them, but comparison should be possible.  Conversion
between them is possible without an explicit conversion ratio -- the ratio
is implicit.  They probably don't have the same display function.

Is there a sensible way to include that concept?

What I'd like is to be able to specify to the conversion routine two
commodities and a price without having to worry about conversions within
USD or whatever.  Being able to be told that \$50 2/8 USD, at \$1.50
CND/\$1.00 USD, is \$75 3/8 without having to specify that \$1 0/8 USD = \$1.00
USD and \$1 0/8 CND = \$1.00CND would make dealing with exchange-rate tables
-much- easier.

```