[Python-Dev] Decimal <-> float comparisons in py3k.

[Glenn Linderman]

On 3/18/2010 2:48 PM, Nick Coghlan wrote:
> When there is a clear, correct way (based on Decimal.from_float) to make
> numeric comparison behave in accordance with the rules of mathematics,
> do we really want to preserve strange, unintuitive behaviour like the above?
>
> Cheers,
> Nick.
>    

I'm aware of nothing that prevents the lazy coder from having a class 
unifiedNumber in his toolbox that implements his favorite type of 
conversions from various numeric types to whatever he thinks is the 
"best" one for his application, and then using it places where sources 
might be of various other numeric types.  I'm aware of nothing that 
would prevent the lazy coder from implement comparison operators and 
even arithmetic operators on such a class.

I believe, but haven't proven, and haven't used Python long enough to 
"just know", that such class could even implement what would appear to 
be operators that would seem to provide implicit conversion from the 
various other numeric classes, as long as one item was of the class.

So I think it would be possible, with such a class, to have one's cake 
(nothing implicit), and eat it too (providing a way do comparisons and 
numerical operations, mostly implicitly).

Glenn