Es-discuss - several decimal discussions

ihab.awad at gmail.com ihab.awad at gmail.com
Sat Aug 23 11:01:17 PDT 2008


On Sat, Aug 23, 2008 at 10:04 AM, Sam Ruby <rubys at intertwingly.net> wrote:
> Decimal implemented as a library would be sufficient for a 3.1
> release.  The problem is an interoperable definition for what infix
> operators is required for completeness.  Taking no other action, the
> default behavior for the result of a "+" operator given a Number and a
> library provided Decimal would be to convert both to string
> representations and concatenate the results.

In other words, the same as the "+" operator given a Number and a
library provided Employee, Document, PopupWidget, ..., or any other
user defined type.

> This was discussed at the last ECMA TC39 meeting in Oslo, and was
> found to be unusable and would create a backwards compatibility issue
> for Harmony.

With respect, I wonder what these would be. It seems that the
fail-fast behavior in this case is useful for (as I pointed out) stuff
like helping establish Sarbanes-Oxley compliance. I understand that
such requirements are why we need decimal arithmetic in the first
place.

> ... spec'ing the operators would not be all that difficult. ... there
> are some usability concerns relating to mixed mode operations
> that we need to work through.

It is precisely these concerns that cause me to wonder if there's a
foundational issue here. Are decimals indeed a different enough beast,
and the pitfalls subtle enough (even if they can be specified
completely), that mixed mode should simply not be supported (i.e.,
made to fail-fast in some backwards compatible way)?

And if mixed mode is not supported, does that mean the library
approach is adequate?

Ihab

-- 
Ihab A.B. Awad, Palo Alto, CA


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