Re: [Scheme-reports] digit-value Marc Feeley (01 Jul 2012 12:55 UTC)
Re: [Scheme-reports] digit-value Alex Shinn (01 Jul 2012 20:28 UTC)
Re: [Scheme-reports] digit-value Marc Feeley (02 Jul 2012 12:08 UTC)
Re: [Scheme-reports] digit-value Alaric Snell-Pym (02 Jul 2012 12:21 UTC)
Re: [Scheme-reports] digit-value John Cowan (03 Jul 2012 07:16 UTC)
Re: [Scheme-reports] digit-value Alaric Snell-Pym (03 Jul 2012 08:50 UTC)
Re: [Scheme-reports] digit-value Pierpaolo Bernardi (03 Jul 2012 09:11 UTC)
Re: [Scheme-reports] digit-value John Cowan (03 Jul 2012 14:45 UTC)
Re: [Scheme-reports] digit-value Pierpaolo Bernardi (03 Jul 2012 15:58 UTC)
Re: [Scheme-reports] digit-value John Cowan (04 Jul 2012 04:22 UTC)
(missing)
Re: [Scheme-reports] digit-value John Cowan (05 Jul 2012 02:25 UTC)
Re: [Scheme-reports] digit-value John Cowan (03 Jul 2012 03:19 UTC)

Re: [Scheme-reports] digit-value Pierpaolo Bernardi 03 Jul 2012 09:11 UTC

On Tue, Jul 3, 2012 at 10:49 AM, Alaric Snell-Pym
<alaric@snell-pym.org.uk> wrote:

>>> char-numeric? certainly seems to be of limited use without it, but
>>> is the char-numeric?/digit-value pair actually useful at all in the
>>> scope of WG1, given string->number?
>>
>> Unless we are to extend `string->number` to handle non-European
>> digits (and then `read`, and then numeric literals?), I think so.
>>
> Well, if digit-value exists and handles all those fun cases, then I
> think that read (and, therefore by definition, numeric literals), should
> do so too for consistency and to avoid having to have two parallel
> digit->number conversions lurking inside every implementation, one a
> subset of the other.

string->number and read accepting as numbers all characters satisfying
the current char-numeric? would be crazy.

Think roman numerals, just to take a simple example we all know about.
Assuming the I are the right unicode character for the roman numeral 1:

(string->number "II")   ==>  2?  11?

Solving this problem does not belong to a library at this level.

P.

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