[plt-scheme] number system

Sorry, the notion of inexact accepting a number-system-radix parameter
doesn't quite make sense as the inexactness comes from the machines inexact
value representation, therefore only an a conversion to exact implies a need
such a parameter defaulting to whatever number-system-radix is defined for
user interaction.

> From: Paul Schlie <schlie at comcast.net>
> One of the suggestions which I really liked and thought it would help
> eliminate a lot of confusion, is the notion of you-see-what-you-get,
> with respect to the conversion between inexact and exact representations;
> as it would seem to be nice to expect something like:
> 
>> (exact 0.3)
> 3/10
>> (inexact (exact 0.3))
> 0.3
>> (inexact 1/3)
> 0.33333333333
>> (exact (inexact 1/3))
> 33333333333/100000000000
> 
> Where both exact and inexact could accept an optional number system radix
> parameter which defines the rounding mode of the conversion (defaulting to the
> environment setting), such that:
> 
>> (exact (inexact 3/10 2) 2)
> 5404319552844595/18014398509481984
> 
> As we get now, likely often creating confusion at times, as opposed to:
> 
>> (exact (inexact 3/10))
> 3/10
> 
> Which most would logically expect.
> 
>> Zhu Chongkai wrote:
>> I just read the "Cleaning up the tower: Numbers in Scheme" from Scheme
>> WorkShop 2004. Although I do not agree with some of the points from the
>> paper, the current number system of Scheme implements is not so
>> satisfying. Will PLT scheme support arbitrary big real number (and
>> more)? Would it be a better solution to add a better number system into
>> SRFI?