[Python-Dev] Re: Re: Decimal type question [Prothon]
mark at prothon.org
Tue Aug 10 05:24:00 CEST 2004
On Mon, 9 Aug 2004 10:48:44 -0700, Andrew P. Lentvorski, Jr. wrote:
> On Aug 9, 2004, at 10:29 AM, Mark Hahn wrote:
>> Forgive me if I'm being a pest, but no one has commented on the real
>> I asked the question. What does everyone think of the idea of having
>> three built-in numeric types?
>> 1) An Int implemented with infinite precision integer (Python Longs)
>> the constant/__str__ form of +-NN such as 0, -123, 173_394, etc.
>> 2) A Decimal implemented with the .Net decimal float (or the IBM
>> decimal if
>> the .Net decimal sucks too much) with the constant/__str__ form of
>> such as 0.0, -123.0, 173_394.0, 173394.912786765, etc.
>> 3) A binary Float implemented with the hardware floating point with the
>> constant/__str__ form of +-NN.NN+-eNN such as 0e0, -123e0, 173.39e+3,
>> 2.35e-78, etc.
> Be careful defining string representations of numbers. It is a
> problem to adhere to the correct internationalization standards.
> Forgive me if I'm being dense, but don't we already have 1 & 3 as built
> in types?
There is no "we". This thread is about Prothon which has nothing yet since
it hasn't ever been released. Your feedback is still relevant and helpful
> 2 is unlikely to be a builtin until folks get some experience using the
> Decimal module. Yes, the .Net Decimal sucks.
> In addition, the desired evolution of Python seems to be replacing the
> binary floating point as the default floating point type with the
> decimal floating point type by default rather than growing another
> builtin numeric type. This is obviously contingent upon the Decimal
> getting some real-life use as well as it getting some speed improvements
> in the future.
>> There would be no automatic conversion except the / operator would
>> from Int to Decimal
> Int goes to the default type of float (which is currently binary FP)
> upon using the / operator.
>> and the Math module would convert Int and Decimal
>> values to Float for almost all functions (except simple ones like abs,
> This is not necessarily a good idea. Exponentials are very useful in
> financial situations and want to be decimals, not binary floats, in
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